WO2014119858A1 - Method for transmitting user's plain data in small cell environment and apparatus therefor - Google Patents

Method for transmitting user's plain data in small cell environment and apparatus therefor Download PDF

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Publication number
WO2014119858A1
WO2014119858A1 PCT/KR2014/000346 KR2014000346W WO2014119858A1 WO 2014119858 A1 WO2014119858 A1 WO 2014119858A1 KR 2014000346 W KR2014000346 W KR 2014000346W WO 2014119858 A1 WO2014119858 A1 WO 2014119858A1
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WO
WIPO (PCT)
Prior art keywords
base station
information
cell
terminal
bearer
Prior art date
Application number
PCT/KR2014/000346
Other languages
French (fr)
Korean (ko)
Inventor
홍성표
Original Assignee
주식회사 케이티
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020130129015A external-priority patent/KR101568310B1/en
Application filed by 주식회사 케이티 filed Critical 주식회사 케이티
Priority to CN201480007262.9A priority Critical patent/CN104969489B/en
Priority to US14/765,334 priority patent/US10149199B2/en
Publication of WO2014119858A1 publication Critical patent/WO2014119858A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/16—Performing reselection for specific purposes
    • H04W36/22—Performing reselection for specific purposes for handling the traffic
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
    • H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W80/00—Wireless network protocols or protocol adaptations to wireless operation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/10—Connection setup
    • H04W76/15—Setup of multiple wireless link connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/04—Large scale networks; Deep hierarchical networks
    • H04W84/042—Public Land Mobile systems, e.g. cellular systems
    • H04W84/045—Public Land Mobile systems, e.g. cellular systems using private Base Stations, e.g. femto Base Stations, home Node B
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W92/00—Interfaces specially adapted for wireless communication networks
    • H04W92/16—Interfaces between hierarchically similar devices
    • H04W92/20—Interfaces between hierarchically similar devices between access points

Definitions

  • the present invention relates to a method and apparatus for transmitting user plane data in a small cell environment in which a terminal is multiplexed with a macro cell and a small cell.
  • LTE Long Term Evolution
  • LTE-Advanced Long Term Evolution-Advanced
  • 3GPP series High-speed large-capacity communication systems capable of transmitting and receiving various data such as video and wireless data beyond voice-oriented services.
  • a small cell and a radio bearer setup are required for the terminal to transmit user plane data through the small cell.
  • the macro cell base station and the terminal are required to perform a procedure for setting a small cell addition / modification or a radio bearer addition / modification to be configured in the base station providing the small cell.
  • the present invention proposes a method and apparatus for adding / modifying a small cell and / or a data radio bearer in order for a terminal to transmit user plane data in a small cell environment.
  • the present invention is to propose a method and apparatus for a first base station to control a procedure of adding / modifying a small cell of a terminal and / or adding / modifying a radio bearer to be configured in a small cell.
  • the present invention for solving the above problems, in the method for the first base station to control the user plane data transmission of the terminal, the second base station based on at least one or more of the load information and the measurement report information of the first base station; Selecting a radio bearer configured to determine user plane data transmission; transmitting a bearer establishment request message to a second base station; receiving a bearer establishment response message from a second base station; And transmitting higher layer signaling comprising at least one of cell identifier information for the cell, second base station cell index information, and data radio bearer information configured through the second base station.
  • the present invention in the method for the terminal to control the user plane data transmission, the cell identifier information, the second base station cell index information and the second base station for the cell associated with the second base station from the first base station is configured Receiving a higher layer signaling including at least one of data radio bearer information, adding or modifying a cell associated with the second base station based on the higher layer signaling, and configuring a data radio bearer for user plane data transmission; It provides a method comprising the steps.
  • the present invention in the first base station for controlling the user plane data transmission of the terminal, selecting a radio bearer configured through the second base station based on at least one or more of the load information and the measurement report information of the first base station Cell identifier information for a cell associated with a second base station to a control unit for determining user plane data transmission, a transmitter for transmitting a bearer establishment request message to a second base station, a receiver for receiving a bearer establishment response message from a second base station, and a terminal;
  • a base station apparatus including a transmitter for transmitting higher layer signaling including at least one of information of second base station cell index information and data radio bearer information configured through the second base station.
  • the terminal for controlling the transmission of the user plane data, the cell identifier information for the cell associated with the second base station from the first base station, the second base station cell index information and data radio configured through the second base station
  • a receiver for receiving higher layer signaling including at least one of bearer information and a controller for adding or modifying a cell associated with the second base station based on the higher layer signaling and configuring a data radio bearer for user plane data transmission; It provides a terminal device including.
  • the macro cell base station provides a method and apparatus for controlling a procedure such as adding / modifying a small cell and / or adding / modifying a radio bearer to be configured in the small cell.
  • FIG. 1 is a diagram illustrating an example of a network configuration scenario to which the present invention can be applied.
  • FIG. 2 is a diagram illustrating an example of a user data transmission model through an interface between a first base station and a second base station to which the present invention can be applied.
  • FIG. 3 is a diagram illustrating an example of a user data transmission model through an interface of a second base station to which the present invention can be applied.
  • FIG. 4 is a signal diagram illustrating operations of a base station and a terminal according to an embodiment of the present invention.
  • FIG. 5 is a signal diagram illustrating operations of a base station and a terminal according to another embodiment of the present invention.
  • FIG. 6 is a signal diagram illustrating the operation of a base station and a terminal according to another embodiment of the present invention.
  • FIG. 7 is a signal diagram illustrating the operation of a base station and a terminal according to another embodiment of the present invention.
  • FIG. 8 is a diagram illustrating the operation of a base station according to another embodiment of the present invention.
  • FIG. 9 is a diagram illustrating an operation of a terminal according to another embodiment of the present invention.
  • FIG. 10 is a diagram illustrating an example of a structure of a user plane data transmission protocol through a second base station interface according to the present invention.
  • FIG. 11 is a diagram illustrating another example of a structure of a user plane data transmission protocol through a second base station interface according to the present invention.
  • FIG. 12 is a diagram illustrating an example of a Layer2 structure of a first base station and a second base station according to the present invention.
  • FIG. 13 is a diagram illustrating another example of a Layer2 structure of a first base station and a second base station according to the present invention.
  • FIG. 14 is a diagram illustrating an example of a Layer2 structure of a terminal according to the present invention.
  • FIG. 15 illustrates another example of a Layer2 structure of a terminal according to the present invention.
  • FIG. 16 illustrates another example of a Layer2 structure of a terminal according to the present invention.
  • 17 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
  • FIG. 18 is a diagram showing the configuration of another terminal according to another embodiment of the present invention.
  • the wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data, and the like.
  • the wireless communication system includes a user equipment (UE) and a base station (base station, BS, or eNB).
  • a user terminal is a comprehensive concept of a terminal in wireless communication.
  • UE user equipment
  • LTE Long Term Evolution
  • HSPA High Speed Packet Access
  • MS Mobile Station
  • UT User Terminal
  • SS Global System for Mobile communications
  • GSM Global System for Mobile communications
  • a base station or a cell generally refers to a station that communicates with a user terminal, and includes a Node-B, an evolved Node-B, an Sector, a Site, and a BTS. It may be called other terms such as a base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and the like.
  • a base transceiver system an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and the like.
  • a base station or a cell is interpreted in a comprehensive sense to indicate some areas or functions covered by a base station controller (BSC) in CDMA, a NodeB in WCDMA, an eNB or a sector (site) in LTE, and the like. It is meant to cover various coverage areas such as mega cell, macro cell, micro cell, pico cell, femto cell and relay node, RRH, RU communication range.
  • BSC base station controller
  • the user terminal and the base station are two transmitting and receiving entities used to implement the technology or technical idea described in this specification in a comprehensive sense and are not limited by the terms or words specifically referred to.
  • the user terminal and the base station are two types of uplink or downlink transmitting / receiving subjects used to implement the technology or the technical idea described in the present invention, and are used in a generic sense and are not limited by the terms or words specifically referred to.
  • the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal
  • the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.
  • CDMA Code Division Multiple Access
  • TDMA Time Division Multiple Access
  • FDMA Frequency Division Multiple Access
  • OFDMA Orthogonal Frequency Division Multiple Access
  • OFDM-FDMA OFDM-TDMA
  • OFDM-CDMA OFDM-CDMA
  • One embodiment of the present invention can be applied to resource allocation in the fields of asynchronous wireless communication evolving to LTE and LTE-Advanced through GSM, WCDMA, HSPA, and synchronous wireless communication evolving to CDMA, CDMA-2000 and UMB.
  • the present invention should not be construed as being limited or limited to a specific wireless communication field, but should be construed as including all technical fields to which the spirit of the present invention can be applied.
  • the uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.
  • TDD time division duplex
  • FDD frequency division duplex
  • Uplink and downlink transmit control information through control channels such as Physical Downlink Control CHannel (PDCCH), Physical Control Format Indicator CHannel (PCFICH), Physical Hybrid ARQ Indicator CHannel (PHICH), and Physical Uplink Control CHannel (PUCCH).
  • a data channel is configured such as PDSCH (Physical Downlink Shared CHannel), PUSCH (Physical Uplink Shared CHannel) and the like to transmit data.
  • a cell means a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.
  • a wireless communication system to which embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-antenna transmission scheme in which two or more transmission / reception points cooperate to transmit a signal.
  • antenna transmission system a cooperative multi-cell communication system.
  • the CoMP system may include at least two multiple transmission / reception points and terminals.
  • the multiple transmit / receive point is at least one having a high transmission power or a low transmission power in a macro cell region, which is connected to an eNB or a macro cell (hereinafter referred to as an 'eNB') and wired controlled by an optical cable or an optical fiber to an eNB. May be RRH.
  • downlink refers to a communication or communication path from a multiple transmission / reception point to a terminal
  • uplink means a communication or communication path from a terminal to multiple transmission / reception points.
  • a transmitter may be part of multiple transmission / reception points, and a receiver may be part of a terminal.
  • a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.
  • a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, and a PDSCH may be described in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, and a PDSCH.
  • the base station performs downlink transmission to the terminals.
  • the base station includes downlink control information such as a physical downlink shared channel (PDSCH), which is a main physical channel for unicast transmission, and scheduling required for reception of the PDSCH and an uplink data channel (eg, For example, a physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission on a physical uplink shared channel (PUSCH) may be transmitted.
  • PDSCH physical downlink shared channel
  • PUSCH physical uplink shared channel
  • Low power nodes represent nodes that use lower transmit (Tx) power than typical macro nodes.
  • CA Carrier Aggregation
  • the macro cell and the RRH cell are constructed to be scheduled under the control of one base station.
  • an ideal backhaul was required between the macro cell base station and the RRH.
  • An ideal backhaul means a backhaul that exhibits very high throughput and very low latency, such as a dedicated point-to-point connection using optical fiber, line of sight (LOS) microwaves.
  • LOS line of sight
  • a plurality of serving cells may be merged to provide a service to a user equipment. That is, a plurality of serving cells may be configured for a UE in a Radio Resource Control (RRC) connected state, and the macro cell and the RRH cell are configured together as a serving cell when an ideal backhaul is established between the macro cell base station and the RRH. Was able to provide services to the terminal.
  • RRC Radio Resource Control
  • the terminal may have only one RRC connection with the network.
  • one serving cell provides NAS mobility information (e.g., TAI: Tracking Area Identity), and an RRC connection In a reset / handover, one serving cell provides a security input.
  • NAS mobility information e.g., TAI: Tracking Area Identity
  • TAI Tracking Area Identity
  • a security input e.g., TAI: Tracking Area Identity
  • PCell primary cell
  • the PCell can only be changed with the handover procedure.
  • SCells Secondary Cells
  • Additions and removals of SCells are performed by RRC.
  • RRC Radio Resource Control
  • DL / UL PCC Downlink / Uplink Primary Component Carrier
  • DL / UL SCC Downlink / Uplink Secondary Component Carrier
  • RLC / PDCP Radio Link Control Layer 2
  • PDCP Packet Data Convergence Protocol
  • Another small cell deployment method could build complementary low power nodes (eg, pico nodes) under the coverage of the existing macro base station layer regardless of the CA technology configuration. That is, it is a method of building a macro base station and a pico base station. As the small cell deployment is increased, the handover in such a heterogeneous environment is greatly increased compared to the network environment constructed only with the macro base station. Thus, potential radio link failures due to signaling load and handover in the network could be increased.
  • complementary low power nodes eg, pico nodes
  • the macro cell and the small cell had to be scheduled under the control of one base station in order to construct a small cell using a carrier aggregation technique. Therefore, there is a problem that an ideal backhaul construction is required between the macro cell base station and the small cell base station. This could induce a high backhaul cost between the macro cell base station and the small cell base station, and could be a factor preventing the spread of the small cell.
  • a small cell in the form of a pico base station may cause more handover than a network constructed only of a macro cell, thereby causing problems such as an increase in signaling load and an increase in handover failure.
  • the present invention relates to a procedure required for efficiently offloading user plane traffic to a small cell under the control of the macro cell in a non-ideal backhaul environment between the macro cell base station and the small cell base station in a mobile communication network. It is aimed at providing apparatus
  • the UE when the UE configures dual connectivity, it forms an RRC connection with the UE, terminates the base station or S1-MME that provides the PCell as a reference for handover, and serves as a mobility anchor for the core network.
  • a base station that is distinguished from a master base station in a dual connectivity environment and provides additional radio resources to a terminal is described as a secondary base station or a second base station.
  • the first base station (master base station) and the second base station (secondary base station) may provide at least one cell to the terminal, respectively, and the first base station and the second base station may be connected through an interface between the first base station and the second base station. have.
  • a cell associated with the first base station may be referred to as a macro cell, and a cell associated with the second base station may be referred to as a small cell for clarity.
  • a cell associated with the first base station may also be described as a small cell.
  • a cell (cell associated with the first base station) provided by the first base station will be described as a macro cell
  • a cell (cell associated with the second base station) provided by the second base station will be described as a small cell.
  • the present invention may be equally applied to the aforementioned dual connectivity between small cells or a small cell cluster scenario.
  • the first base station described herein may be used in the same sense as the master base station, and the second base station may be used in the same meaning as the secondary base station.
  • secondary cell or small cell or SCell described herein refers to a cell associated with a second base station
  • master cell or macro cell or PCell refers to a cell associated with a first base station
  • FIG. 1 is a diagram illustrating an example of a network configuration scenario to which the present invention can be applied.
  • the terminal 102 is located in macro cell coverage and small cell coverage. That is, the terminal 102 may be simultaneously included in the small cell coverage overlapped in the macro cell coverage.
  • the macro cell and the small cell have different carrier frequencies and a non-ideal backhaul is established between the first base station 110 and the second base station 120.
  • a macro cell and a small cell are constructed through different base stations and have an interface between the first base station 110 and the second base station 120.
  • the terminal 102 may transmit data only through the second base station 120.
  • the second base station 120 may operate as a stand-alone base station to transmit control plane data. Accordingly, the terminal 102 may establish one RRC connection with the second base station 120, and may configure one or more signaling radio bearers (SRBs). In addition, the terminal 102 may establish one or more DRBs (Data Radio Bearers) with the second base station 120 for user plane data transmission.
  • SRBs signaling radio bearers
  • DRBs Data Radio Bearers
  • the terminal 102 transmits user plane data through the second base station 120 under the control of the first base station 110 (or through cooperation between the second base station and the first base station). Can be. Alternatively, the terminal 102 may transmit user plane data through the second base station 120 under cooperative control between the second base station 120 and the first base station 110.
  • the terminal 102 may establish one RRC connection with the first base station 110 and transmit one or more signaling radio bearers (SRBs) for control plane data transmission. .
  • the terminal 102 may establish one or more DRBs (Data Radio Bearers) with the second base station 120 for user plane data transmission.
  • SRBs signaling radio bearers
  • DRBs Data Radio Bearers
  • FIG. 2 is a diagram illustrating an example of a user data transmission model through an interface between a first base station and a second base station to which the present invention can be applied.
  • user data may be transferred from a serving gateway (S-GW), which is an Evolved Packet Core (EPC) entity, to a first base station, and then the first base station may be transmitted to a terminal through a second base station.
  • S-GW serving gateway
  • EPC Evolved Packet Core
  • FIG. 3 is a diagram illustrating an example of a user data transmission model through an interface of a second base station to which the present invention can be applied.
  • user data may be delivered to a terminal through a second base station directly from a serving gateway (S-GW) which is a core network entity.
  • S-GW serving gateway
  • the solid line indicates the control plane data transmission path and the dotted line indicates the user plane data transmission path.
  • the terminal may be controlled under the control of the first base station (or through cooperation with the second base station), through both the first base station and the second base station, or through only the first base station.
  • User plane data may also be transmitted.
  • the terminal establishes one RRC connection with the first base station and transmits one or more Signaling Radio Bearers (SRBs) for control plane data transmission.
  • SRBs Signaling Radio Bearers
  • the UE may configure one or more Data Radio Bearers (DRBs) in the first base station and the second base station for user plane data transmission.
  • DRBs Data Radio Bearers
  • the UE may configure one or more DRBs through only the first base station for user plane data transmission.
  • the terminal may transmit all data only through the first base station when it is only under the first base station coverage (eg, macro cell). That is, the terminal may establish one RRC connection with the first base station and control one or more Signaling Radio Bearers (SRBs) for control plane data transmission. In addition, the terminal may configure one or more DRBs (Data Radio Bearers) with the first base station for user plane data transmission.
  • SRBs Signaling Radio Bearers
  • DRBs Data Radio Bearers
  • the terminal may transmit all data only through the second base station when it is only under the second base station coverage (eg, a small cell). That is, the terminal may establish one RRC connection with the second base station and transmit one or more Signaling Radio Bearers (SRBs) for control plane data transmission. In addition, the terminal may configure one or more DRBs (Data Radio Bearers) with the second base station for user plane data transmission.
  • SRBs Signaling Radio Bearers
  • DRBs Data Radio Bearers
  • the second base station transmits user plane data under the control of the first base station or in cooperation with the first base station.
  • the UE may establish an RRC connection only through a cell provided by the first base station.
  • the terminal may establish one RRC connection (connection) only through the first base station.
  • the macro serving cell provided by the first base station provides NAS mobility information (eg TAI: Tracking Area Identity) and security input (RAI) in RRC connection establishment / reestablishment / handover. can do. That is, the first base station can process necessary signaling between the terminal and the first base station, and can also process necessary signaling between the terminal and the second base station.
  • TAI Tracking Area Identity
  • RAI security input
  • the small cell when the small cell provided by the second base station provides a service to the terminal together with the macro cell provided by the first base station, the small cell may be configured as a serving cell along with the macro cell according to the terminal capabilities. Can be. Alternatively, the small cell may be configured as secondary cells (SCells) or serving cells under the control of the first base station according to terminal capabilities. Alternatively, the small cell may be configured as secondary cells (SCells) or serving cells that transmit user plane data under the control of the first base station according to terminal capabilities. Alternatively, the macro cell may transmit control plane data according to terminal capabilities, and the small cell may be configured of secondary cells (SCells) or serving cells that transmit user plane data.
  • SCells secondary cells
  • SCells serving cells that transmit user plane data.
  • the procedure of adding or removing the small cell provided by the second base station to the serving cell or the secondary cell for user plane data transmission may be performed by RRC signaling through the first base station.
  • a procedure of adding or releasing one or more DRBs (Data Radio Bearers) through the second base station may also be performed by RRC signaling through the first base station. If the first base station decides to add the small cell provided by the second base station as a serving cell or secondary cell for user plane data transmission, or to add one or more DRBs through the second base station, the first base station uses RRC signaling. All required system information of the small cell provided by the second base station can be transmitted. That is, in the connected mode, the terminal may not need to acquire system information broadcasted directly from the small cell provided by the second base station.
  • a method of broadcasting including the small cell identification information in the system information.
  • the NAS (Non Access Stratum) layer of the terminal identifies the selected Public Land Mobile Network (PLMN) and the equivalent PLMN.
  • PLMN Public Land Mobile Network
  • the terminal searches for Evolved Universal Terrestrial Access (E-UTRA) frequency bands and identifies the strongest cell for each carrier frequency.
  • E-UTRA Evolved Universal Terrestrial Access
  • the terminal reads cell system information to identify the PLMN. In this case, when the cell system information includes the small cell identification information, the terminal may identify such a cell as the small cell and select the macro cell when there is an available macro cell for cell selection.
  • the second base station broadcasts the small cell related information as system information.
  • the second base station is a small cell identification information for identifying whether the terminal is a small cell provided by the second base station (for example, information for distinguishing that the cell can transmit the user plane data with the terminal under the control of the first base station or Small cell indication information) is broadcast as system information (eg, SIB1).
  • SIB1 system information
  • the terminal may identify whether the corresponding cell is a small cell provided by the second base station using this information.
  • the above-described small cell identification information is information for distinguishing that the UE and the user plane data can be transmitted under the control of the first base station.
  • the small cell identification information indicating the small cell or the small cell is not the small cell or the small cell ID information. At least one of cell type information may be used.
  • the second base station may prevent the terminal from camping on the small cell by using the cell access related information displayed in the system information block type 1 (SystemInformationBlockType1). That is, by setting the cell barred information to "barred", it is possible to prevent the small cell from being selected.
  • SystemInformationBlockType1 SystemInformationBlockType1
  • the UE performs a search for cell selection on available macro cell use frequencies and performs a search for cell selection on a small cell use frequency only when there is no available macro cell, or on a small cell use frequency. You can disable searching for cell selection.
  • the information on the frequency used as the small cell may be broadcast through the system information of the first base station or through the system information of the second base station. Or it can be configured in the USIM inside the terminal.
  • the terminal or the second base station may initiate a cell reselection procedure to select the macro cell.
  • the first base station and / or the second base station may broadcast the macro cell frequency by setting the cell reselection priority frequency through system information.
  • the first base station and / or the second base station may transmit the RRC connection release message or the RRC connection reconfiguration message by including information for setting the macro cell frequency as the reselection priority frequency. have. Inter-frequency cell reselection is based on the absolute priority of the highest priority frequency available that the UE wants to camp on. Therefore, the cell reselection may be performed from the macro cell to the small cell through the cell reselection.
  • the second base station may establish an RRC connection with the second base station so as to establish an RRC connection with the macro cell by performing a handover procedure for the UE in the RRC connected state.
  • the second base station includes the information necessary for selecting the macro cell in the RRC connection release message for the terminal in the RRC connection state by establishing an RRC connection with the second base station. By doing so, the terminal may select the macro cell.
  • the terminal Small cell addition and DRBs may be configured for user plane data transmission by discovering / identifying small cells.
  • the UE may configure small cell addition and DRBs for user plane data transmission using the discovered / identified small cell.
  • the terminal may configure DRBs by adding a small cell for transmitting user plane data based on the measurement report according to the small cell discovery / identification.
  • the UE discovers / identifies a small cell ( discovery / identification) may be used to add small cells and DRBs for user plane data transmission.
  • the UE may configure small cell addition and DRBs for user plane data transmission using the discovered / identified small cell.
  • the terminal may configure DRBs by adding a small cell for transmitting user plane data based on the measurement report according to the small cell discovery / identification.
  • a small cell capable of transmitting user plane data can be discovered using the following method; Identification can be done.
  • small cells are made by performing inter-frequency measurements using the measurement rules and measurement gap patterns specified in the 3GPP standard document (E-UTRAN Requirements for support of radio resource management). Can be detected.
  • the existing standardized measurement gap pattern has a measurement gap of 6 ms and a gap periodicity of 40 ms and 80 ms.
  • the terminal may report measurement information on the corresponding small cell.
  • the small cell may be detected by using a method in which the measurement period is longer than the conventional measurement period for the inter-frequency measurement.
  • the above-mentioned gap period (one of 40ms and 80ms) can be made longer for inter-frequency measurements for efficient small cell sensing.
  • the terminal may report measurement information on the corresponding small cell.
  • the small cell may be detected by using a method in which the measurement period is shorter than the conventional measurement period for inter-frequency measurement for fast small cell detection.
  • the gap period one of 40 ms and 80 ms
  • the measurement may be performed without gap assistance.
  • the UE detects a small cell having a stronger signal (eg, RSRP: Reference Signal Received Power, RSRQ: Reference Signal Received Quality) than a specific threshold T1
  • the terminal may report measurement information on the corresponding small cell.
  • the RRC connection establishment through the first base station includes a signaling radio bearer 1 (SRB1) configuration.
  • the first base station may complete the RRC connection setup before completing the S1 connection setup. That is, RRC connection setup may be completed before receiving UE context information from the MME.
  • the first base station may configure measurement reporting to the terminal.
  • the first base station When the first base station receives the terminal context from the MME, the first base station can activate security (ciphering and integrity protection) using an initial security activation procedure.
  • security ciphering and integrity protection
  • RRC messages for activating security are integrity protected, while encryption begins after the procedure is completed.
  • the first base station After initiating the initial security activation procedure, the first base station initiates SRB2 and DRBs setup. That is, the first base station may do this before receiving confirmation of the initial security activation from the terminal.
  • the first base station may use an RRC connection reconfiguration message to configure SRB2 and DRBs.
  • the DRBs may be DRBs for user plane data transmission through the second base station.
  • the DRBs may be DRBs for user plane data transmission through the first base station and the second base station.
  • the above message applies both encryption and integrity protection.
  • the second base station may transmit a second terminal to the terminal supporting user plane data transmission through the second base station under the control of the first base station or any terminal or carrier supporting carrier aggregation (CA).
  • the small cell provided by the base station can be configured. That is, the first base station may configure a small cell provided by the second base station in addition to the macro cell (or PCell) provided by the first base station initially configured during connection establishment. Small cells are used to transmit user plane data by providing downlink and uplink radio resources. For example, the first base station may use an RRC connection reconfiguration message to add, modify or remove the aforementioned small cell.
  • the first base station adds, modifies, or removes a small cell provided by the second base station to transmit user plane data through the second base station, or adds DRBs through the second base station.
  • the procedure for correcting or removing is described.
  • First Embodiment A method of adding / modifying / removing small cells and adding / modifying / removing DRBs through a second base station as a procedure.
  • FIG. 4 is a signal diagram illustrating operations of a base station and a terminal according to an embodiment of the present invention.
  • a first base station In a method of controlling user plane data transmission of a terminal, a first base station according to an embodiment of the present invention is configured through a second base station based on at least one or more of load information and measurement report information of the first base station. Selecting a radio bearer to determine user plane data transmission; transmitting a bearer establishment request message to a second base station; receiving a bearer establishment response message from a second base station; and a terminal for a cell associated with the second base station.
  • the method may include transmitting higher layer signaling including at least one of cell identifier information, second base station cell index information, and data radio bearer information configured through the second base station.
  • the first base station 401 includes receiving measurement reporting information and determining user plane data transmission through a radio bearer of a cell associated with the second base station (S415).
  • the first base station 401 adds, modifies, or removes small cells or transmits DRBs through the second base station to transmit user plane data through the second base station 402 to the terminal 403 in an RRC connection state. It may determine the procedure to add, modify or remove (S415).
  • the first base station 401 may use a first base station (eg, an E-RAB Level QoS parameter, terminal capability) in the initial context setup request message received from the MME.
  • a first base station eg, an E-RAB Level QoS parameter, terminal capability
  • the DRB to serve through 401 and the DRB to serve through the second base station 402 may be determined.
  • the first base station 401 may determine based on at least one or more of measurement reporting information that can be received from the terminal 403 and data load information of the first base station (S415). That is, the DRB to be serviced through the first base station 401 and the DRB to be serviced through the first base station 401 and the second base station 402 may be determined.
  • the first base station 401 may initiate a bearer setup signaling procedure for user plane data transmission to the second base station 402 according to the determination. That is, the first base station 401 may determine the load, measurement reporting information, etc. of the first base station based on QoS parameters (QCI, Allocation and Retention Priority (GBR QoS)) for each E-RAB, and / or through the second base station (or the first base station). E-RAB to be transmitted) can be selected). For example, an E-RAB having a GBR bearer or a specific QCI or a specific Allocation and Retention Priority value may be transmitted through the first base station 401 and may not request DRB establishment from the second base station 402.
  • QoS parameters QCI, Allocation and Retention Priority (GBR QoS)
  • GBR QoS Allocation and Retention Priority
  • an E-RAB with a non-GBR bearer or other specific QCI or other specific Allocation and Retention Priority value for Internet traffic may request DRB establishment to transmit via the second base station.
  • the DRB may be requested for transmission through the first base station and the second base station.
  • the first base station 401 may transmit a bearer setup request message to the second base station 402 (S420).
  • the first base station 401 determines user plane data transmission through the second base station (for example, add / modify a small cell or add / modify a small cell or DRBs to a small cell)
  • a bearer setup request message for user plane data transmission is transmitted to the second base station 402 before or after the aforementioned security activation procedure is initiated (S420).
  • a bearer setup request message for user plane data transmission is determined. Can be sent (S420).
  • the first base station terminal X2AP (X2 application protocol) identifier information, the cell identifier information associated with the second base station, the second base station cell index information, the terminal maximum bit rate (UE) Aggregate Maximum Bit Rate) and E-RABs (E-UTRAN Radio Access Bearers) setup list information may include at least one or more information.
  • the information described below may be included.
  • the bearer establishment request message for user plane data transmission through the second base station 402 may include one or more of the following information.
  • ⁇ Message Type Contains information to identify the procedure type of the message.
  • First Base Station Terminal X2AP Identifier (ID): Included by the master base station, identifier information uniquely identifying the terminal through the X2 interface in the master base station.
  • ID associated with the second base station: Contains E-UTRAN Cell Global Identifier (ECGI) or small cell Physical Cell ID (PCI) information of the cell provided by the second base station.
  • EGI E-UTRAN Cell Global Identifier
  • PCI Physical Cell ID
  • Second base station cell (small cell) index Cell (small cell) provided in the SCells configured in the terminal or in cells (small cells) provided by the second base station configured in the terminal or provided by the second base station configured in the terminal SCell (small) In the cell) or SCells composed of cells provided by the second base station to the terminal, index information for identifying a cell (small cell) or SCell provided by each second base station is included.
  • Terminal context information The terminal context information may include the following information.
  • UE Security capabilities Contains information about the algorithms supported for encryption and integrity protection in the terminal. Or information about an algorithm supported for encryption in the terminal. Or information about an algorithm supported for encryption of user plane data in the terminal. Alternatively, the UE Security capabilities information may be managed only at the first base station without being included in the bearer establishment request message described above.
  • AS Security Information or AS Security Key Includes encryption key (K UPenc ) information for user plane data at the second base station. Or base station key (K eNB ) information for deriving an encryption key K UPenc .
  • K UPenc encryption key
  • K eNB base station key
  • the above information may use the same value as K UPenc or K eNB of the first base station or may use a different value.
  • UE-AMBR UE Aggregate Maximum Bit Rate
  • the terminal may include a UE Aggregate Maximum Bit Rate (UE-AMBR).
  • UE-AMBR UE Aggregate Maximum Bit Rate
  • the terminal may include processing rate information of (UE Aggregate Maximum Bit Rate, UE-AMBR).
  • E-RABs To Be Setup List (E-RABs) Setup List (E-RABs) through the second base station (E-RABs To Be Setup List) information: Contains information on the E-RABs setup item.
  • the E-RABs setup item may include at least one or more of an E-RAB ID, an E-RAB Level QoS parameter, and GTP Tunnel Endpoint information.
  • the E-RAB ID may include information for identifying a radio access bearer for the terminal.
  • the E-RAB Level QoS parameter is Quality of Service (QoS) information applied to the E-RAB and may include QCI, Allocation and Retention Priority, and GBR QoS information.
  • QoS Quality of Service
  • the GTP tunnel endpoint is an endpoint of a bearer for transmitting user plane data between the first base station and the second base station.
  • Tunnel Endpoint ID an IP address of a base station.
  • the transport layer address and the GTP TEID which are IP addresses of the S-GW, as endpoints between the S-GW and the second base station. (Tunnel Endpoint ID) may be included.
  • UE Capability Information Contains UE capability information necessary for configuring radio resources for user data transmission through a second base station among UE capability information included in UE context information received through the MME. For example, it may include information related to single transmission / reception (single Tx / Rx) or multiple transmission / reception (multi Tx / Rx).
  • the bearer establishment request message may include at least one or more pieces of information described above as an example.
  • the first base station 401 may receive a bearer setup response message from the second base station 402 (S425).
  • the second base station 402 Upon receiving the bearer setup request message for user plane data transmission from the first base station 401, the second base station 402 transmits a bearer setup response message to the first base station 401 (S425).
  • the bearer establishment response message may include cell identifier information associated with a second base station, second base station cell index information, second base station cell random access channel preamble information, second base station cell system information, and a second base station. It may include at least one or more of cell-specific MAC layer configuration information, E-UTRAN Radio Access Bearers (E-RABs) acceptance list information, and second base station data radio bearer configuration information for the accepted E-RAB.
  • E-RABs E-UTRAN Radio Access Bearers
  • the bearer setup response message may further include at least one or more of first base station identifier information, second base station identifier information, and dedicated radio resource configuration information. In addition, it may further include each piece of information described below by way of example.
  • the bearer establishment response message may include one or more of the following information.
  • ⁇ Message Type Contains information to identify the procedure type of the message.
  • First base station terminal X2AP identifier (ID): Contains identifier information allocated by the first base station.
  • Second base station terminal X2AP identifier (ID): Contains identifier information allocated by the second base station.
  • ID associated with the second base station: E-UTRAN Cell Global Identifier (ECGI) or Small Cell Physical Cell ID (PCI) of the small cell associated with the second base station, Absolute Radio Frequency Channel (ARFCN) Or identification information for distinguishing that the cell is associated with the second base station (for example, whether the cell is associated with the second base station through one bit and displayed separately).
  • E-UTRAN Cell Global Identifier ECGI
  • PCI Small Cell Physical Cell ID
  • ARFCN Absolute Radio Frequency Channel
  • identification information for distinguishing that the cell is associated with the second base station for example, whether the cell is associated with the second base station through one bit and displayed separately.
  • Second Base Station Cell (Small Cell) Index Secondary Cell (Small Cell) Small in SCells Configured in Terminal or Secondary Cells (Small Cells) Associated in Second Base Station Configured in Terminal or Associated with Second Base Station Configured in SCell in Terminal Cell information) or index information for identifying a secondary cell (small cell) or a SCell associated with each second base station, in SCells configured with a secondary cell associated with a second base station.
  • E-RABs may include E-RABs Accepted Item information.
  • E-RABs acceptance item information includes E-RAB ID, GTP Tunnel Endpoint, DRB Identifier (DRB ID), PDCP Configuration Information (PDCP-Config), RLC Configuration Information (RLC-Config), Logical Channel Identity, Logical Channel It may include at least one of configuration information (logicalChannelConfig) and physical channel configuration information (PhysicalConfigDedicated).
  • the E-RAB ID includes information for identifying a radio access bearer for the terminal.
  • the GTP tunnel endpoint is a bearer endpoint between the first base station and the second base station when transmitting user plane data through an interface between the first base station and the second base station as shown in FIG. 2.
  • the GTP tunnel terminal is an endpoint between the S-GW and the second base station.
  • GTP TEID (Tunnel Endpoint ID) is included.
  • the E-RABs acceptance item information may include second base station data radio bearer configuration information for the accepted E-RAB.
  • PDCP configuration information is a PDCP layer for a radio bearer to transmit through the second base station in the terminal, when transmitting the user plane data through the interface between the S-GW and the second base station as shown in FIG. Contains configuration information.
  • the RLC configuration information includes RLC layer configuration information for a radio bearer transmitted through a second base station in the terminal.
  • the logical channel identifier (logicalChannelIdentity) and logical channel configuration information (logicalChannelConfig) represents a logical channel identifier (logicalChannelIdentity), logical channel configuration information (logicalChannelConfig) for the radio bearer transmitted through the second base station in the terminal.
  • Physical channel configuration information (PhysicalConfigDedicated) represents the physical layer configuration information in the terminal for the radio bearer transmitted through the second base station
  • ⁇ E-RABs non-acceptance list includes radio bearer list information that cannot be processed among radio bearers requested through the second base station according to the load or state of the second base station.
  • the second base station may include all request bearer lists in the unaccepted list or change the message type (eg, reject message). Can pass
  • Second base station cell random access channel preamble preamble information (eg, ra-PreambleIndex included in RACH-ConfigDedicated information) for performing a contention free random access procedure through a cell associated with the second base station.
  • preamble information eg, ra-PreambleIndex included in RACH-ConfigDedicated information
  • Second base station cell (small cell) system information System information for the secondary cell or small cell configured by the second base station.
  • Common radio resource configuration information RadioResourceConfigCommon information
  • PDSCH-config System information for the secondary cell or small cell configured by the second base station.
  • the bearer establishment response message may include at least one or more of each of the above information.
  • the first base station 401 is a terminal 403, which is a cell (small cell) identifier information associated with a second base station for a cell associated with a second base station, and a second base station cell (small cell) index.
  • the method may include transmitting higher layer signaling including at least one of information and data radio bearer information configured through the second base station (S430).
  • the first base station 401 completes the bearer setup signaling procedure for transmitting user plane data with the second base station 402 (for example, after receiving a bearer setup response message, step S425). Later) it may include cell (small cell) information provided by the second base station to be added / modified to higher layer signaling (eg, an RRC connection reconfiguration message) (S430).
  • cell small cell information provided by the second base station to be added / modified to higher layer signaling (eg, an RRC connection reconfiguration message) (S430).
  • the first base station 401 may transmit higher layer signaling to the terminal 403 after initiating a bearer establishment signaling procedure (for example, after transmitting a bearer establishment request message, and after step S420).
  • the terminal 403 may receive higher layer signaling from the first base station 401 and add / modify a cell (small cell) associated with the second base station for user plane data transmission.
  • the cell (small cell) associated with the second base station may be added / modified as a secondary cell.
  • at least one of cell identifier information and second base station cell index information associated with the second base station according to another embodiment of the present invention may be used. It may be included in the DRB (DRB-ToAddMod) information to be additionally modified.
  • the terminal 403 distinguishes the first base station 401 and the second base station 402 in the MAC layer. At least one of the following information and information for distinguishing the cell provided by the first base station 401 and the cell provided by the second base station 402 may be included.
  • the above-described higher layer signaling includes cell (small cell) information associated with the second base station to be added / modified, cell identifier information, second base station cell index information, and the like associated with the second base station for identifying the second base station cell; For example, radio resource configuration information of data radio bearer information configured through the second base station will be described below.
  • ⁇ Cell (small cell) identifier associated with the second base station Among the distinguishing information for distinguishing the Physical Cell ID (PCI), the Absolute Radio Frequency Channel (ARFCN), and the second base station cell of the cell (small cell) associated with the second base station It includes at least one or more information.
  • the classification information for identifying the second base station cell may be display information for distinguishing and displaying whether the cell is associated with the second base station through 1 bit.
  • Second base station cell (small cell) index (or SCell index): Second base station cell (small cell) configured in SCells configured in UE or in second base station cells (small cells) configured in UE or configured in SCell ) Or index information used to identify each second base station secondary cell (small cell) or SCell in SCells configured as a second base station cell (small cell) in the terminal.
  • the above-described second base station cell index information may be determined or allocated by the first base station and included in the bearer setup request message. However, it may not be included in the bearer setup response message.
  • the above-described second base station cell index information may be determined or allocated by the first base station and included in the bearer setup request message, and may be included in the bearer setup response message by the second base station.
  • the second base station cell index (or SCell index) information may be determined or allocated by the second base station and included in the bearer setup response message. At this time, it may not be included in the bearer setup request message of the first base station.
  • the second base station cell index (or SCell index) information may be different from a value used as an existing SCell index (for example, 1 to 7) to distinguish the second base station cell from the SCell of the first base station. (Eg, 8) can be used. In this case, it may not be included in both the bearer establishment request message and the bearer establishment response message. Or it may be included in the bearer setup request message and / or bearer setup response message.
  • SCell index that can currently have an integer value from 1 to 7 can be an integer value from 1 to 14, and 1 to 7
  • the integer value of may be used as an index for SCells of a master base station (first base station) and 8 to 14 as an index for a secondary base station (second base station) cell.
  • the SCell index and the second base station identifier (or second base station cell identifier) field may be transmitted together to distinguish the second base station cell from the SCell of the first base station.
  • the SCell index may be configured by including one bit in the SCell index as a field for identifying the second base station cell (or second base station cell) so as to distinguish the second base station cell from the first base station SCell.
  • Small cell common radio resource configuration information essential information for the UE to operate in a cell (small cell) associated with the second base station (physical layer configuration parameters or physical layer configuration parameters and MAC layer configuration corresponding to the system configuration information) It may include a parameter.
  • Small cell dedicated radio resource configuration information UE-specific configuration information (e.g. physical channel configuration, mac-MainConfig) for operation in the cell (small cell) associated with the second base station may be included.
  • UE-specific configuration information e.g. physical channel configuration, mac-MainConfig
  • the small cell dedicated radio resource configuration information includes RLC layer configuration information in a terminal for a radio bearer transmitted through the aforementioned second base station, logical channel identifier (logicalChannelIdentity) and logic for a radio bearer transmitted through the second base station.
  • RLC layer configuration information in a terminal for a radio bearer transmitted through the aforementioned second base station
  • logicalChannelIdentity logical channel identifier
  • logic for a radio bearer transmitted through the second base station logicalChannelIdentity
  • One or more of channel configuration information (logicalChannelConfig), preamble information for performing a contention free random access procedure with a cell associated with a second base station, and physical layer configuration information for a radio bearer transmitted through the second base station.
  • the terminal 403 may add / modify a cell associated with the second base station by receiving higher layer signaling including the above information (S435).
  • the terminal 403 may add / modify a cell associated with the second base station and transmit user plane data to the second base station 402 (S440).
  • the first base station 401 may control the DRB addition / modification / change of the terminal by including data radio bearer information configured through the second base station in higher layer signaling.
  • the RRC connection reconfiguration ( Connection Reconfiguration) message may be transmitted including the DRBs information to be added / modified (S430).
  • the terminal 403 may receive higher layer signaling to add / modify the second base station 402 and the DRBs for user plane data transmission or to modify the DRBs of the first base station 401 to the DRBs of the second base station 402. have. Alternatively, the terminal 403 may modify the DRBs of the first base station 401 into DRBs through the first base station 401 and the second base station 402.
  • the radio bearer information configured through the data second base station includes data radio bearer identification information, Packet Data Convergence Protocol (PDCP) and Radio Link Control (RLC) configuration information, logical channel identifier, and logical channel. At least one of configuration information and cell identifier information associated with the first base station may be included.
  • PDCP Packet Data Convergence Protocol
  • RLC Radio Link Control
  • the data radio bearer information configured through the second base station 402 includes information for the terminal 403 to distinguish the first base station 401 and the second base station 402 in the MAC layer and the first base station 401. ) May include at least one or more of information for distinguishing a cell provided by the cell) and a cell provided by the second base station 402.
  • the data radio bearer information including the DRBs information to be added / modified may include at least one of the following information.
  • EPS bearer identifier may include E-RAB ID information.
  • a cell (small cell) identifier associated with the second base station at least one or more pieces of information for identifying a physical cell ID (PCI), an absolute radio frequency channel (ARFCN) and a second base station cell of the cell associated with the second base station. It may include.
  • the classification information for identifying the second base station cell may be information for distinguishing and displaying whether the cell is associated with the second base station through 1 bit.
  • Second base station cell (small cell) index within the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured with the SCell in the terminal or Within the SCell configured as the second base station cell (small cell) in the terminal, it may include index information used to identify each second base station cell (small cell) or SCell.
  • DRB-ID Contains DRB-ID information received from the second base station.
  • PDCP-Config Contains PDCP-Config information received from the second base station.
  • RLC-Config Contains RLC-Config information received from the second base station.
  • ⁇ logicalChannelIdentity Contains information about logical channel identifier.
  • ⁇ logicalChannelConfig Contains information about logical channel configuration information received from the second base station.
  • the first base station 401 transmits a higher layer signaling including data radio bearer information described above after initiating a bearer establishment signaling procedure (for example, transmitting a bearer establishment request message to a second base station). After).
  • the terminal 403 receives upper layer signaling from the first base station 401 and adds / modifies DRBs and DRBs of the second base station 402 and transmits DRBs of the first base station 401 for the user plane data transmission. It may be modified to the DRBs of 402 (S435).
  • the terminal 403 may modify the DRBs of the first base station 401 into DRBs through the first base station 401 and the second base station 402 (S435).
  • the data radio bearer information transmitted after the bearer establishment request message transmission may include at least one of the following information.
  • EPS bearer identifier may include E-RAB ID information.
  • ⁇ Cell (small cell) identifier associated with the second base station It may include Physical Cell ID (PCI), Absolute Radio Frequency Channel (ARFCN) information of the cell associated with the second base station.
  • PCI Physical Cell ID
  • ARFCN Absolute Radio Frequency Channel
  • Second base station cell (small cell) index within the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured with the SCell in the terminal or Within the SCell configured as the second base station cell (small cell) in the terminal, it may include index information used to identify each second base station cell (small cell) or SCell.
  • the information may include DRB-ID information determined by the first base station and delivered to the second base station.
  • PDCP-Config may include PDCP-Config information determined by the first base station and delivered to the second base station.
  • ⁇ RLC-Config may include RLC-Config information determined by the first base station and delivered to the second base station.
  • ⁇ logicalChannelIdentity Can include logical channel identifier information.
  • ⁇ logicalChannelConfig It can contain logical channel configuration information.
  • the first base station 401 may transmit higher layer signaling including the above information to the terminal 403 after receiving the bearer establishment response message or after transmitting the bearer establishment request message.
  • identification information for distinguishing the second base station cell (small cell) and the first base station cell (macro cell) together with DRB information to be added / modified or DRB information to be released. May be further included to indicate that the aforementioned DRB to be added / modified is configured through the small cell (or the second base station).
  • the information on the DRB to be added / modified may be a small cell identifier (or second base station identifier information). It may include.
  • the information about the DRB to be released may include the DRB information to be released in the macro cell and macro cell identifier information (or first base station identifier information) together.
  • the above-described second base station cell (small cell) index or SCell index can distinguish the second base station cell (or second base station), the above-described second base station cell ( Small cell) index or SCell index may be included.
  • the first base station 401 when the first base station 401 according to an embodiment of the present invention includes data radio bearer information in higher layer signaling, a subject for determining each parameter of the included information will be described in detail.
  • the higher layer signaling further includes information for cell configuration associated with the second base station, and information for cell configuration associated with the second base station is set by the second base station and transmitted to the first base station. It may be one piece of information.
  • the second base station cell index information and the data radio bearer information configured through the second base station may be information set by the second base station and transmitted to the first base station.
  • the information for cell configuration associated with the second base station may be set by the first base station based on at least one or more of measurement reporting information, first base station data load information, and bearer setup response message.
  • the first base station 401 may include at least one of information (eg, E-RABs list), measurement reporting information, and data load information of the first base station in an initial context setup request message received from the MME.
  • the information may be included in the bearer establishment request message and transmitted to the second base station 402.
  • the second base station 402 may determine the parameters included in the above-described higher layer signaling based on the transmitted information.
  • the second base station 402 may determine the second base station cell index information and the data radio bearer information configured through the second base station or a parameter included in each information based on the transmitted information.
  • the determined parameter information may be transmitted to the first base station and transmitted to the terminal through higher layer signaling (eg, an RRC Connection Reconfiguration message).
  • higher layer signaling eg, an RRC Connection Reconfiguration message
  • the first base station 401 may include at least one of information (eg, E-RABs list), measurement reporting information, and data load information of the first base station in an initial context setup request message received from the MME. Decisions can be made based on information. That is, the above-described parameters (eg, PDCP configuration information, RLC configuration information, MAC configuration information, etc.) included in higher layer signaling (eg, RRC Connection Reconfiguration message) may be determined by the first base station 401. Can be.
  • information eg, E-RABs list
  • measurement reporting information e.g., measurement reporting information
  • the first base station 401 may include information (eg, E-RABs list), measurement reporting information, data load information of the first base station, and a second base station in an initial context setup request message received from the MME. A determination may be made based on the bearer establishment response message received from 402.
  • FIG. 5 is a signal diagram illustrating operations of a base station and a terminal according to another embodiment of the present invention.
  • the first base station 501 may include cell identification information associated with a second base station for accessing a cell associated with a second base station by a terminal 503, high base station signaling, second base station cell system information, At least one of the second base station dedicated MAC layer configuration information and the second base station cell random access channel preamble may be further included and transmitted (S530).
  • the terminal 503 may receive the relevant information for accessing the cell associated with the second base station from the first base station 501 and perform a random access procedure for uplink synchronization with the second base station 502 ( S535).
  • the first base station 501 may include and transmit relevant information for cell access associated with the second base station in the above-described higher layer signaling.
  • the step S535 of performing the random access procedure for uplink synchronization with the second base station 502 described above may include adding / modifying a cell associated with the second base station and DRBs associated with the second base station (eg, dedicated to the second base station). Bearer or the first base station and the second base station bearer) may be performed before the step (S545).
  • the step S535 of performing the random access procedure for uplink synchronization with the second base station 502 described above may include adding / modifying a cell associated with the second base station and DRBs associated with the second base station (for example, a second base station). Dedicated bearer or the first base station and the second base station bearer) may be performed after the step (S545).
  • the step S535 of performing the random access procedure for uplink synchronization with the second base station 502 described above may include adding / modifying a cell associated with the second base station and DRBs associated with the second base station (for example, a second base station).
  • Dedicated bearer or the first base station and the second base station bearer may be performed in parallel with the step (S545).
  • the first base station 501 completes the bearer establishment signaling procedure for transmitting user plane data with the second base station 502 (for example, after receiving a bearer establishment response message (S525) or the second base station and the S)
  • uplink synchronization random access of the UE is performed through higher layer signaling (for example, an RRC connection reconfiguration message).
  • Information may be transmitted (S530).
  • the first base station 501 performs a uplink synchronization with the terminal 503 to the second base station cell (small cell) and establishes a random access channel (RACH) for transmission to the second base station cell (small cell).
  • RACH random access channel
  • Cell identification information and radio resource configuration information of the cell to be accessible through the transmission may be included.
  • the above-described radio resource configuration information of the second base station cell is used for the operation of the second base station cell system information, the random access channel preamble, and the second base station cell (small cell) received through the bearer setup response message.
  • the related information for accessing the second base station cell is transmitted through higher layer signaling, but may be transmitted in a step separate from the higher layer signaling transmission.
  • the terminal 503 After receiving the upper layer signaling (eg, an RRC connection reconfiguration message) including radio resource configuration information of the second base station cell (small cell), the terminal 503 receives the second base station 502. Uplink synchronization is performed through the cell and the RACH procedure. If the dedicated random access channel preamble information is included, the random access procedure may be performed according to the "contention-free” procedure. Or, if the dedicated random access channel preamble is not included, the random access procedure is performed according to the "contention-based" procedure (S535).
  • the upper layer signaling eg, an RRC connection reconfiguration message
  • the UE when performing a random access procedure according to a contention-free procedure, the UE sends a RACH preamble generated in the second base station cell and received through the first base station to the second base station cell, thereby responding to the RACH response.
  • a random access procedure can be performed by receiving a message RAR from a second base station cell.
  • the above-described higher layer signaling may include small cell information to be added / modified, DRBs information to be added / modified, and random access information for uplink synchronization together in one message, or a separate message. It may also include each of the one or more information described above to be transmitted.
  • FIG. 6 is a signal diagram illustrating the operation of a base station and a terminal according to another embodiment of the present invention.
  • the transmitting of the upper layer signaling to the terminal 603 by the first base station 601 may be transmitted before receiving the bearer establishment response message from the second base station 602. There is (S625).
  • the higher layer signaling may include small cell (cell associated with the second base station) information to be added / modified in one message, DRBs information to be added / modified, and random access related information for uplink synchronization.
  • small cell cell associated with the second base station
  • DRBs information to be added / modified
  • random access related information for uplink synchronization may be included in a separate message and transmitted.
  • higher layer signaling may be transmitted after transmitting a bearer establishment request message to the second base station 602 or may be transmitted after receiving a bearer establishment response message.
  • the random access related information for uplink synchronization may be transmitted to the terminal 603 before receiving the bearer setup response message.
  • the terminal 503 transmits user plane data through the DRBs established with the second base station (S550).
  • Second Embodiment A method for performing small cell (cell associated with a second base station) addition / modification / removal and DRBs addition / modification / removal via a second base station as a separate procedure.
  • the first base station transmits at least one of message type information, second base station identifier information, secondary cell identifier information, and secondary index information to the second base station before the bearer setup request message transmission step. Transmitting a secondary cell addition modification request message including; and a cell identifier information associated with a second base station, a second base station cell index information, a second base station cell random access channel preamble information, and a second base station cell radio resource configuration from the second base station.
  • the method may further include receiving a secondary cell addition modification response message including at least one piece of information.
  • FIG. 7 is a signal diagram illustrating the operation of a base station and a terminal according to another embodiment of the present invention.
  • the first base station 701 includes determining user plane data transmission through the radio bearer of the second base station cell based on at least one of the measurement reporting information and the data load information (S715).
  • the first base station 701 may determine a procedure for adding, modifying, or removing small cells or adding, modifying, or removing DRBs through the second base station for transmitting user plane data through the second base station 702. (S715).
  • the first base station 701 may include at least one of information (eg, an E-RAB Level QoS parameter), measurement reporting information, and data load information in an initial context setup request message received from the MME.
  • information eg, an E-RAB Level QoS parameter
  • the above information may be used to determine a DRB to be serviced through the first base station 701 and a DRB to be serviced through the second base station 702, and bearer configuration signaling for user plane data transmission to the second base station 702. May be initiated. That is, the first base station 701 is to transmit through the second base station in consideration of the load, measurement reporting information, etc. of the first base station based on QoS parameters (QCI, Allocation and Retention Priority, GBR QoS) for each E-RAB.
  • QoS parameters QI, Allocation and Retention Priority, GBR QoS
  • E-RAB can be selected. For example, an E-RAB having a GBR bearer or a specific QCI or a specific Allocation
  • the first base station 701 sends a secondary cell addition modification request message for small cell addition / modification to the second base station 702 (S720).
  • the first base station 701 determines the small cell addition / modification based on the measurement reporting or in the RRC connected state
  • the first base station 701 determines the small cell addition / modification to the second base station 702.
  • the secondary cell addition modification request message may be sent (S720).
  • the above-described secondary cell addition modification request message may include at least one or more of the following information.
  • ⁇ Message Type May contain information to identify the procedure type of the message.
  • First base station terminal X2AP identifier (ID): It may include identifier information allocated by the first base station.
  • ⁇ Cell (small cell) identifier (ID) associated with the second base station It may include information on the E-UTRAN Cell Global Identifier (ECGI) or the second base station cell PCI (Physical cell ID) of the second base station cell.
  • EGI E-UTRAN Cell Global Identifier
  • PCI Physical cell ID
  • Second base station cell (small cell) index in the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured in the terminal SCell or
  • the terminal may include index information for identifying each second base station cell (small cell) or SCell in SCells configured as a second base station cell.
  • the second base station 702 may transmit a secondary cell addition modification response message to the first base station 701 (S725).
  • the second base station 702 receiving the secondary cell addition modification request message including the small cell addition / modification request information from the first base station transmits the secondary cell addition modification response message to the first base station 701. It may be (S725).
  • the above-described secondary cell addition modification request message may include at least one or more of the following information.
  • ⁇ Message Type May contain information to identify the procedure type of the message.
  • First base station terminal X2AP identifier (ID): It may include identifier information allocated by the first base station.
  • Second base station terminal X2AP identifier (ID): It may include identifier information allocated by the second base station.
  • ⁇ Cell (small cell) identifier associated with the second base station It may include information about PCI and Absolute Radio Frequency Channel Number (ARFCN) of the cell associated with the second base station.
  • ARFCN Absolute Radio Frequency Channel Number
  • Second base station cell (small cell) index in the SCells configured in the terminal 703 or in the second base station cells (small cells) configured in the terminal SCell, or in the SCells configured in the terminal second cell, respectively
  • An index used to identify a second base station cell (small cell) or an SCell of may be determined or assigned by the second base station 702.
  • the second base station cell (small cell) index or SCell index may be determined or allocated by the first base station 701 and included in the secondary cell addition modification request message. At this time, the secondary cell addition modification response message may not be included.
  • the second base station cell index or SCell index may be determined or allocated by the first base station 701 to be included in the secondary cell addition modification request message and transmitted. At this time, it may be included in the secondary cell addition modification response message.
  • the second base station cell index or the SCell index may use a value (for example, 8) that is not a value (for example, 1 to 7) used as the existing SCell index, in which case the above-described secondary cell It may not be included in both the addition request message and the secondary cell addition response message. Or it may include in the above-described secondary cell addition modification request message and / or secondary cell addition modification response message.
  • the SCell index that can currently have an integer value from 1 to 7 can be an integer value from 1 to 14, and an integer from 1 to 7
  • the value may be used as an index for SCells of the first base station and 8 to 14 as an index for the second base station.
  • the SCell index and the second base station identifier (or cell identifier of the second base station) field may be sent together so that the SCell index of the first base station and the SCell index of the second base station can be distinguished.
  • Small cell common radio resource configuration information information on a physical layer configuration parameter or a physical layer configuration parameter and a MAC layer configuration parameter corresponding to the system configuration information as essential information for the terminal to operate in a cell associated with the second base station. It may include.
  • Small cell dedicated radio resource configuration information UE-specific physical channel configuration for the cell associated with the second base station or terminal-specific configuration information for the cell associated with the second base station (physical channel configuration) ) And MAC layer configuration parameters (eg, mac-MainConfig).
  • Random Random Channel (RACH) preamble information may include information related to the preamble for performing a contention free random access procedure through the cell of the second base station.
  • the first base station 701 may transmit the secondary cell addition modification request message including the above information to the second base station 702 and receive the secondary cell addition modification response message including the above information. have.
  • the first base station 701 determines user plane data transmission through the second base station 702 (eg, determines to add / modify DRBs to a cell associated with the second base station), it initiates a security activation procedure. Before or after the transmission of the bearer request message to the second base station 702 to transmit the user data (S730). Alternatively, in the RRC Connected state, the first base station 701 transmits a bearer setup request message to the second base station 702 to transmit user data for transmitting user data through a cell (small cell) associated with the second base station. (S730). Alternatively, the first base station 701 transmits a bearer setup request message to the second base station 702 in order to transmit user data through the first base station and the second base station (S730).
  • the bearer establishment request message for user plane data transmission through the second base station 702 may include at least one of the following information.
  • the information included in the bearer establishment request message will be described below.
  • ⁇ Message Type May contain information to identify the procedure type of the message.
  • First base station terminal X2AP identifier (ID): It may include identifier information allocated by the first base station.
  • ⁇ Cell (Small Cell) Identifier (ID) associated with the second base station may include E-UTRAN Cell Global Identifier (ECGI) of the cell associated with the second base station or cell PCI (Physical Cell ID) information associated with the second base station. have.
  • ECGI E-UTRAN Cell Global Identifier
  • PCI Physical Cell ID
  • Second base station cell (small cell) index in the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured in the terminal SCell or
  • the terminal may include index information for identifying each second base station cell (small cell) or SCell in SCells configured as a second base station cell.
  • the terminal context information may include the following information.
  • UE Security capabilities Contains information about the algorithms supported for encryption and integrity protection in the terminal. Or information about an algorithm supported for encryption in the terminal. Or information about an algorithm supported for encryption of user plane data in the terminal. Alternatively, the UE Security capabilities information may be managed only at the first base station without being included in the bearer establishment request message described above.
  • AS Security Information or AS Security Key Includes encryption key (K UPenc ) information for user plane data at the second base station. Or base station key (K eNB ) information for deriving an encryption key K UPenc .
  • K UPenc encryption key
  • K eNB base station key
  • the above information may use the same value as K UPenc or K eNB of the first base station or may use a different value.
  • UE-AMBR UE Aggregate Maximum Bit Rate
  • the UE may include a UE Aggregate Maximum Bit Rate (UE-AMBR).
  • UE-AMBR UE Aggregate Maximum Bit Rate
  • the UE-AMBR UE Aggregate Maximum Bit Rate
  • It may include processing rate information of (UE Aggregate Maximum Bit Rate, UE-AMBR).
  • E-RABs To Be Setup List (E-RABs)
  • E-RABs To Be Setup List) information through the second base station Contains the E-RABs setup item.
  • the E-RABs setup item may include at least one or more of an E-RAB ID, an E-RAB Level QoS parameter, and GTP Tunnel Endpoint information.
  • the E-RAB ID includes information for identifying a radio access bearer for the terminal.
  • the E-RAB Level QoS parameter is Quality of Service (QoS) information applied to the E-RAB and includes QCI, Allocation and Retention Priority, and GBR QoS information.
  • QoS Quality of Service
  • the GTP tunnel endpoint transmits user plane data through an interface between the first base station and the second base station, as shown in FIG. 2, an endpoint of a bearer for transmitting user plane data between the first base station and the second base station.
  • GTP tunnel endpoint is an transport layer that is an IP address of the S-GW as an endpoint between the S-GW and the second base station. It may include an address and a GTP Tunnel Endpoint ID (TEID).
  • TEID GTP Tunnel Endpoint ID
  • UE Capability Information Contains UE capability information necessary for configuring radio resources for user data transmission through a second base station among UE capability information included in UE context information received through the MME. For example, it includes single Tx / Rx or multi Tx / Rx information.
  • the bearer establishment request message may include at least one or more pieces of information described above as an example.
  • the first base station 701 may receive a bearer setup response message from the second base station 702 (S735).
  • the second base station 702 Upon receiving the bearer setup request message for user plane data transmission from the first base station 701, the second base station 702 transmits a bearer setup response message to the first base station 701 (S735).
  • the bearer establishment response message may include one or more of the following information.
  • ⁇ Message Type Information that identifies the procedure type of the message.
  • ⁇ Cell (Small Cell) Identifier (ID) associated with the second base station E-UTRAN Cell Global Identifier (ECGI) of the cell associated with the second base station or cell PCI (Physical Cell ID) information associated with the second base station.
  • ECGI E-UTRAN Cell Global Identifier
  • PCI Physical Cell ID
  • Second base station cell (small cell) index in the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured in the terminal SCell or
  • the terminal includes index information for identifying each second base station cell (small cell) or SCell in SCells configured as a second base station cell.
  • E-RABs may include E-RABs accepted item information.
  • E-RABs acceptance item information includes E-RAB ID, GTP Tunnel Endpoint, DRB Identifier (DRB ID), PDCP Configuration Information (PDCP-Config), RLC Configuration Information (RLC-Config), Logical Channel Identity, Logical Channel It may include at least one of configuration information (logicalChannelConfig) and physical channel configuration information (PhysicalConfigDedicated).
  • the E-RAB ID includes information for identifying a radio access bearer for the terminal.
  • the GTP tunnel endpoint is a bearer endpoint between the first base station and the second base station when user plane data is transmitted through an interface between the first base station and the second base station as shown in FIG. 2.
  • the GTP tunnel endpoint is an end point between the S-GW and the second base station.
  • GTP TEID (Tunnel Endpoint ID) is included.
  • the PDCP configuration information indicates PDCP layer configuration information for a radio bearer transmitted through the second base station when transmitting user plane data through the interface between the S-GW and the second base station as shown in FIG. 3.
  • RLC configuration information indicates RLC layer configuration information for a radio bearer transmitted through a second base station.
  • the logical channel identifier (logicalChannelIdentity) and logical channel configuration information (logicalChannelConfig) represents a logical channel identifier (logicalChannelIdentity) and logical channel configuration information (logicalChannelConfig) for the radio bearer transmitted through the second base station.
  • Physical channel configuration information (PhysicalConfigDedicated) represents the physical layer configuration information for the radio bearer transmitted through the second base station
  • E-RABs non-acceptance list information It includes radio bearer list information that cannot be processed among the radio bearers requested through the second base station according to the load or state of the second base station. For example, if the traffic load is high and all request bearers cannot be processed, the second base station may include all request bearer lists in the unacceptable list or forward a message of different message types (eg, rejection message). Can
  • Random Random Channel (RACH) preamble information includes preamble information for performing a contention free random access procedure through the cell of the second base station.
  • the bearer establishment response message may include at least one or more of the above information.
  • the first base station 701 may transmit cell information associated with the second base station to be added / modified to higher layer signaling (eg, an RRC connection reconfiguration message) to the terminal 703 (S740).
  • higher layer signaling eg, an RRC connection reconfiguration message
  • the terminal 703 may add / modify a cell associated with the second base station based on the information included in the received higher layer signaling.
  • Cell information associated with the second base station to be added / modified may be set based on the information included in the above-described secondary cell addition modification response message.
  • ⁇ Cell (small cell) identifier associated with the second base station It may include information about the Physical Cell ID (PCI), the Absolute Radio Frequency Channel (ARFCN) of the second base station small cell.
  • PCI Physical Cell ID
  • ARFCN Absolute Radio Frequency Channel
  • Second base station cell (small cell) index second base station cell (small cell) configured in SCells configured in the terminal or second base station cell (small cells) configured in the terminal or configured in the terminal or SCell in the terminal ) Or index information used to identify each second base station cell (small cell) or SCell in SCells configured as a second base station cell (small cell) in the terminal.
  • the above-described index information may be determined or assigned by the second base station.
  • the second base station cell (small cell) index may be determined or assigned by the first base station to be included in the secondary cell addition modification request message and may not be included in the secondary cell addition modification response message.
  • the second base station cell (small cell) index may be determined or allocated by the first base station and included in the secondary cell addition modification request message. After the second base station confirms this, it may be included in the secondary cell addition modification response message.
  • the second base station cell (small cell) index or SCell index may use a value (for example, 8) that is not a value (for example, 1 to 7) that is used as an existing SCell index. It may not be included in both the secondary cell addition modification request message and the secondary cell addition modification response message.
  • the second base station cell (small cell) index or SCell index may use a value (for example, 8) that is not a value (for example, 1 to 7) used as the existing SCell index, and the secondary cell. It may be included in the additional modification request message and / or the secondary cell additional modification response message.
  • the SCell index that can currently have an integer value from 1 to 7 can be an integer value from 1 to 14, and an integer from 1 to 7
  • the value may be used as an index for SCells of the first base station and 8 to 14 as an index for the second base station.
  • the SCell index and the second base station identifier (or cell identifier of the second base station) field may be sent together so that the SCell index of the first base station and the SCell index of the second base station can be distinguished.
  • Small cell common radio resource configuration information essential information for the UE to operate in a cell associated with the second base station, and includes physical layer configuration parameters or physical layer configuration parameters and MAC layer configuration parameters corresponding to the system configuration information. Can be.
  • Small cell dedicated radio resource configuration information UE-specific physical channel configuration or UE-specific configuration information and MAC layer configuration parameters (for example, for operation in the cell associated with the second base station) mac-MainConfig).
  • the terminal 703 may add / modify a cell (small cell) associated with the second base station by receiving higher layer signaling including the above information (S745).
  • higher layer signaling eg, , RRC connection reconfiguration message
  • DRBs information may be added / modified (S740).
  • the terminal 703 may add / modify the DRBs with the second base station 702 or may modify the DRBs of the first base station 701 with the DRBs of the second base station. Alternatively, the terminal 703 may modify the DRBs of the first base station 701 into DRBs through the first base station 701 and the second base station 702.
  • the aforementioned DRBs information to be added / modified may include at least one or more of the following information.
  • EPS bearer identifier may include E-RAB ID information.
  • ⁇ Cell (small cell) identifier associated with the second base station It may include information about the Physical Cell ID (PCI), the Absolute Radio n Frequency Channel (ARFCN) of the cell associated with the second base station.
  • PCI Physical Cell ID
  • ARFCN Absolute Radio n Frequency Channel
  • Second base station cell (small cell) index within the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured with the SCell in the terminal or It includes index information used to identify each second base station cell (small cell) or SCell in SCells configured as a second base station cell (small cell) in the terminal.
  • DRB-ID Contains DRB-ID information received from the second base station.
  • PDCP-Config Contains PDCP-Config information received from the second base station.
  • RLC-Config Contains RLC-Config information received from the second base station.
  • ⁇ logicalChannelIdentity Contains information about logical channel identifier.
  • ⁇ logicalChannelConfig Contains information about logical channel configuration information received from the second base station.
  • the first base station may initiate a bearer establishment signaling procedure for transmitting user plane data or DRBs with the second base station (for example, after transmitting a bearer establishment request message to the second base station, S730).
  • the DRBs information to be added / modified in the layer signaling (for example, an RRC connection reconfiguration message) is transmitted to the terminal (S740).
  • the terminal 703 may add / modify the second base station and the DRBs based on the information included in the received higher layer signaling, or may modify the DRBs of the first base station to the DRBs of the second base station (S745).
  • the above-described DRBs information to be added / modified may include at least one or more of the following information.
  • EPS bearer identifier may include E-RAB ID information.
  • ⁇ Cell (small cell) identifier associated with the second base station It may include information about the Physical Cell ID (PCI), the Absolute Radio Frequency Channel (ARFCN) of the cell associated with the second base station.
  • PCI Physical Cell ID
  • ARFCN Absolute Radio Frequency Channel
  • Second base station cell (small cell) index within the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured with the SCell in the terminal or Within the SCell configured as the second base station cell (small cell) for the terminal, it may include index information used to identify each second base station cell (small cell) or SCell.
  • the information may include DRB-ID information determined by the first base station and delivered to the second base station.
  • PDCP-Config Contains PDCP-Config information determined by the first base station and delivered to the second base station.
  • RLC-Config Includes RLC-Config information determined by the first base station and delivered to the second base station.
  • ⁇ logicalChannelIdentity Contains information about logical channel identifier.
  • ⁇ logicalChannelConfig Contains information about logical channel configuration information.
  • the data radio bearer information configured through the second base station may include information for distinguishing the first base station and the second base station from the MAC layer by the terminal, and distinguishing a cell provided by the first base station and a cell provided by the second base station. It may include at least one or more of the information for.
  • the information on the DRB to be added / modified may include the second base station small cell identifier.
  • the information about the DRB to be released may include both the DRB information to be released in the macro cell and the first base station macro cell identifier information.
  • the above-described second base station cell (small cell) index or SCell index may be included in the aforementioned DRB to be added / modified.
  • the first base station 701 transmits data radio bearer information in higher layer signaling, the subject for determining each parameter of the included information will be described in detail.
  • the higher layer signaling further includes information for cell configuration associated with the second base station, and information for cell configuration associated with the second base station is set by the second base station and transmitted to the first base station. It may be one piece of information. That is, the second base station cell index information and the data radio bearer information configured through the second base station may be information set by the second base station and transmitted to the first base station.
  • the information for cell configuration associated with the second base station may be set by the first base station based on at least one or more of measurement reporting information, first base station data load information, and bearer setup response message.
  • the first base station 701 may include information (for example, terminal context information such as E-RABs list), measurement reporting information, and data load information included in an initial context setup request message received from the MME. At least one information may be included in the bearer establishment request message and transmitted to the second base station 702.
  • information for example, terminal context information such as E-RABs list
  • measurement reporting information such as E-RABs list
  • data load information included in an initial context setup request message received from the MME.
  • At least one information may be included in the bearer establishment request message and transmitted to the second base station 702.
  • the second base station 702 may determine a parameter included in the above-described higher layer signaling based on the transmitted information. That is, the second base station 702 may determine the second base station cell index information and the data radio bearer information configured through the second base station or a parameter included in each information based on the transmitted information.
  • the determined parameter information may be transmitted to the first base station and transmitted to the terminal through higher layer signaling (eg, an RRC connection reconfiguration message).
  • higher layer signaling eg, an RRC connection reconfiguration message
  • the first base station 701 is based on at least one of information (eg, E-RABs list), measurement reporting information, and data load information in the initial context setup request message received from the MME. You can decide. That is, the above-described parameters (eg, PDCP configuration information, RLC configuration information, MAC configuration information, etc.) included in higher layer signaling (eg, RRC Connection Reconfiguration message) may be determined by the first base station 701. Can be.
  • the first base station 701 may include at least one of information (eg, E-RABs list), measurement reporting information, and data load information in the initial context setup request message received from the MME, and the second.
  • the determination may be based on the bearer establishment response message received from the base station 702.
  • the UE may perform a random access procedure for uplink synchronization with the second base station by receiving the related information for accessing the cell associated with the second base station from the first base station.
  • the first base station After the first base station completes the bearer setup signaling procedure for user plane data transmission with the second base station (eg, after receiving a bearer setup response message), higher layer signaling (eg, an RRC Connection Reconfiguration message) Through the random access related information for uplink synchronization of the terminal can be transmitted.
  • higher layer signaling eg, an RRC Connection Reconfiguration message
  • the first base station enables the terminal to perform uplink synchronization with a cell (small cell) associated with the second base station and access a cell (small cell) associated with the second base station through a random access channel (Random Access Chennel, RACH).
  • the mobile station may further include at least one of cell identification information, second base station cell system information, second base station dedicated MAC layer configuration information, and second base station cell random access channel preamble associated with the second base station.
  • the related information for performing access to the cell associated with the second base station is transmitted through higher layer signaling, but may be transmitted in a step separate from the higher layer signaling transmission.
  • the terminal receives higher layer signaling (eg, an RRC connection reconfiguration message) including radio resource configuration information of a cell (small cell) associated with the second base station, and then synchronizes with a cell associated with the second base station.
  • higher layer signaling eg, an RRC connection reconfiguration message
  • the random access procedure may be performed according to the "contention-free” procedure. Or, if the dedicated random access channel preamble is not included, the random access procedure is performed according to the "contention-based" procedure.
  • the UE when performing a random access procedure according to a contention-free procedure, the UE sends a RACH preamble generated in the cell associated with the second base station and received through the first base station to the second base station cell, and corresponding thereto.
  • the random access procedure may be performed by receiving the response message RAR from the second base station cell.
  • the above-described higher layer signaling may include cell (small cell) information associated with a second base station to be added / modified in one message, DRBs information to be added / modified, and random access related information for uplink synchronization. May be included together, or each of the above-described information may be included in a separate message and transmitted.
  • the first base station 701 may transmit higher layer signaling to add a cell associated with the second base station to the terminal after the above-described secondary cell addition modification request message transmission (S720) and the secondary cell addition modification response message reception (S725).
  • S740 may be transmitted.
  • the aforementioned bearer establishment request message transmission (S730) and bearer establishment response message reception (S735) may be performed, and another upper layer signaling transmission may be performed.
  • the terminal 703 transmits user plane data through the DRBs established with the second base station 702 (S750).
  • each embodiment has been described in detail in a method in which the first base station controls user plane data transmission of the terminal.
  • FIG. 8 is a diagram illustrating the operation of a base station according to another embodiment of the present invention.
  • the first base station selects a radio bearer configured through the second base station based on at least one of the first base station load information and the measurement report information to perform user plane data transmission. It may be determined (S810).
  • the first base station transmits a bearer setup request message to the second base station (S820).
  • the bearer setup request message may include: first base station terminal X2 application protocol (X2AP) identifier information, cell identifier information associated with the second base station, second base station cell index information, terminal aggregate maximum bit rate, and E- It may include at least one or more information from E-UTRAN Radio Access Bearers (RABs) setup list information.
  • X2AP X2 application protocol
  • E- It may include at least one or more information from E-UTRAN Radio Access Bearers (RABs) setup list information.
  • RABs E-UTRAN Radio Access Bearers
  • the first base station receives a bearer setup response message from the second base station (S830).
  • the bearer establishment response message includes cell identifier information associated with the second base station, second base station cell index information, second base station cell random access channel preamble information, second base station cell system information, second base station cell dedicated MAC layer configuration information, E At least one of E-UTRAN Radio Access Bearers (RABs) acceptance list information and second base station data radio bearer configuration information for the accepted E-RAB may be included.
  • E-UTRAN Radio Access Bearers RABs
  • the first base station may transmit higher layer signaling to the terminal (S840).
  • Higher layer signaling may include at least one of cell identifier information for a cell associated with a second base station, second base station cell index information, and data radio bearer information configured through the second base station.
  • the higher layer signaling may further include at least one or more of second base station cell system information, second base station dedicated MAC layer configuration information, and second base station cell random access channel preamble.
  • Each information parameter (or detailed information) included in higher layer signaling is as described above, for example.
  • the data radio bearer information configured through the second base station includes information for distinguishing the first base station and the second base station from the MAC layer, a cell provided by the first base station, and a cell provided by the second base station. It may include at least one or more information of the information for distinguishing.
  • the first base station may transmit information necessary for random access for uplink synchronization with the second base station to the terminal. Such information may be included in the above-described higher layer signaling or transmitted in a separate message form.
  • the first base station transmits the message type information, the second base station identifier information, and the cell associated with the second base station to the second base station before the bearer setup request message transmission step.
  • the method may further include receiving a secondary cell addition modification response message including at least one of base station cell random access channel preamble information and second base station cell radio resource configuration information.
  • FIG. 9 is a diagram illustrating an operation of a terminal according to another embodiment of the present invention.
  • a terminal in a method for controlling transmission of user plane data, includes cell identifier information, second base station cell index information, and a second base station for a cell associated with a second base station from a first base station.
  • the method may include receiving higher layer signaling including at least one or more information among data radio bearer information configured through S910.
  • the method may include adding or modifying a cell associated with the second base station based on the received higher layer signaling and configuring a data radio bearer for user plane data transmission (S920). Thereafter, the terminal may transmit user plane data using the configured data radio bearer (S930).
  • the terminal may separately configure a MAC entity for the first base station and a MAC entity for the second base station in the MAC layer.
  • the MAC entity for the second base station may be configured by dividing the scheduling priority processing entity and the multiplexing entity for the radio bearer configured through the second base station.
  • the data radio bearer information configured through the second base station may include information for distinguishing the first base station and the second base station from the MAC layer, and distinguishing a cell provided by the first base station and a cell provided by the second base station.
  • Information may include at least one or more information.
  • the terminal may include cell identification information, second base station cell system information, second base station cell random access channel preamble information, and the like associated with a second base station for a terminal to access a cell associated with a second base station.
  • the UE may perform upper layer signaling including at least one of terminal specific configuration information including MAC layer configuration information of the second base station and perform a random access procedure for uplink synchronization with a cell associated with the second base station.
  • the information for accessing the cell associated with the second base station may be received together with the information for small cell addition / modification or DRB addition / modification.
  • FIG. 10 is a diagram illustrating an example of a structure of a user plane data transmission protocol through a second base station interface according to the present invention.
  • the user plane data transmission method of the present invention described above may be applied in the protocol structure for user plane data transmission as shown in FIG.
  • FIG. 11 is a diagram illustrating another example of a structure of a user plane data transmission protocol through a second base station interface according to the present invention.
  • the user plane data transmission method of the present invention described above may also be applied to the protocol structure for user plane data transmission as shown in FIG.
  • the protocol structure of FIG. 11 may be applied to a case where the first base station forwards user plane data to the second base station and transmits it to the terminal as shown in FIG. 2.
  • FIG. 12 is a diagram illustrating an example of a Layer2 structure of a first base station and a second base station according to the present invention.
  • FIG. 12 illustrates the Layer 2 protocol structure of the first base station and the second base station in detail when the protocol structure of FIG. 11 is used.
  • a first base station transmits a PDCP entity to deliver user data to a first base station in units of a radio bearer in a PDCP layer, and a PDCP entity to transmit to a second base station (or to a first base station and a second base station).
  • PDCP entity may have a function of switching (or routing) a PDCP protocol data unit (PDU) to be delivered to a second base station.
  • PDU PDCP protocol data unit
  • the second base station has one Hybrid automatic repeat request (HARQ) entity for processing a cell associated with the second base station.
  • the first base station may have a plurality of HARQ objects when the first base station supports the existing carrier aggregation technology.
  • the second base station may also have a plurality of HARQ objects when the second base station supports the existing carrier aggregation technology.
  • FIG. 13 is a diagram illustrating another example of a Layer2 structure of a first base station and a second base station according to the present invention.
  • FIG. 13 shows the Layer2 protocol structure of the first base station and the second base station in detail when using the user data transmission model of FIG. 3.
  • the PDCP entity of the first base station to be transmitted through the first base station in units of radio bearers and the PDCP entity of the second base station to be transmitted through the second base station are previously described in accordance with the above-described procedures. Are separated.
  • the second base station has one Hybrid automatic repeat request (HARQ) entity for processing a cell associated with the second base station.
  • the first base station may have a plurality of HARQ objects when the first base station supports the existing carrier aggregation technology.
  • the second base station may also have a plurality of HARQ objects when the second base station supports the existing carrier aggregation technology.
  • FIG. 14 is a diagram illustrating an example of a Layer2 structure of a terminal according to the present invention.
  • a PDCP entity of a first base station to be transmitted through a first base station in units of radio bearers and a PDCP entity of a second base station to be transmitted through a second base station are distinguished.
  • the MAC layer is a logical channel belonging to the radio bearer to be delivered through the second base station.
  • Logical channels may be mapped to transport channels (eg, downlink shared channels (DL-SCHs) or uplink shared channels (UL-SCHs)) through a second base station.
  • transport channels eg, downlink shared channels (DL-SCHs) or uplink shared channels (UL-SCHs)
  • the above-described logical channel configuration information may include information for distinguishing cells (small cells) associated with the second base station or radio bearer through the second base station.
  • the information for identifying a cell associated with a second base station may be a logical channel group or priority or cell identifier information associated with a second base station, second base station cell index information, or newly defined information (second base station radio bearer indication information). Can be.
  • a logical channel ID may be distinguished for a cell (small cell) associated with a second base station, or a mapping table may be switched based on this.
  • FIG. 15 illustrates another example of a Layer2 structure of a terminal according to the present invention.
  • FIG. 15 illustrates in detail the Layer2 protocol structure of a terminal implemented in a method different from that of FIG. 14.
  • the MAC layer (object) for the first base station and the MAC layer (object) for the second base station are separated from the MAC layer.
  • the scheduling / priority handling entity for the first base station, multiplexing entity, multiplexing entity, HARQ entity, and the aforementioned entities for the second base station may be respectively present. Therefore, when the terminal is configured with one or more SCells or serving cells, if the SCells or serving cells include a cell (small cell) associated with the second base station, the second base station MAC entity is a radio bearer to be delivered through the second base station. Logical channels belonging to may be mapped to transport channels (eg, downlink shared channels (DL-SCHs) or uplink shared channels (UL-SCHs) through a second base station.
  • transport channels eg, downlink shared channels (DL-SCHs) or uplink shared channels (UL-SCHs) through a second base station.
  • the above-described logical channel configuration information may include information for identifying a cell (small cell) associated with the second base station or a radio bearer through the second base station.
  • the distinguishable information may include logicalchannel group or priority or cell identifier information associated with the second base station or second base station cell index information or newly defined information (second base station radio Bearer display information) can be.
  • the UDP protocol may be replaced with a SCTP protocol.
  • FIG. 16 illustrates another example of a Layer2 structure of a terminal according to the present invention.
  • FIG. 16 illustrates in detail the Layer2 protocol structure of a terminal implemented in a method different from those of FIGS. 14 and 15.
  • an RLC layer (object) for the first base station and an RLC layer (object) for the second base station are separated and provided in duplicate.
  • it may have a scheduling / priority handling entity for the first base station, a multiplexing entity, a HARQ entity, an RLC entity, and the aforementioned entities for the second base station, respectively.
  • the PDCP layer may have an entity for separating and switching data into a first base station RLC layer and a second base station RLC layer.
  • the method of the present invention described with reference to FIGS. 4 to 9 may be implemented by both the base station and the terminal to be described below.
  • 17 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
  • a base station 1700 includes a controller 1710, a transmitter 1720, and a receiver 1730.
  • the controller 1710 controls the overall operation of the base station according to controlling the user plane data transmission method through the second base station under the control of the first base station required to perform the above-described present invention.
  • the transmitter 1720 and the receiver 1730 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention.
  • the controller 1710 may determine a user plane data transmission by selecting a radio bearer configured through the second base station based on at least one of measurement reporting information and data load information of the first base station.
  • the transmitter 1720 may transmit a bearer setup request message to the second base station.
  • the bearer setup request message may include: first base station terminal X2 application protocol (X2AP) identifier information, cell identifier information associated with the second base station, second base station cell index information, terminal aggregate maximum bit rate, and E- It may include at least one or more information from E-UTRAN Radio Access Bearers (RABs) setup list information.
  • X2AP X2 application protocol
  • E- It may include at least one or more information from E-UTRAN Radio Access Bearers (RABs) setup list information.
  • RABs E-UTRAN Radio Access Bearers
  • the transmitter 1720 transmits at least one of message type information, second base station identifier information, cell identifier information associated with the second base station, and second base station cell index information to the second base station according to another embodiment of the present invention.
  • the secondary cell addition modification request message may be transmitted.
  • the transmitter 1720 is a terminal for higher layer signaling including at least one or more of the cell identifier information for the cell associated with the second base station, the second base station cell index information and the data radio bearer information configured through the second base station Can be sent to.
  • the higher layer signaling may further include at least one or more information of the second base station cell system information, the second base station dedicated MAC layer configuration information, and the second base station cell random access channel preamble.
  • the data radio bearer information configured through the above-described second base station may include information for distinguishing a first base station and a second base station from a MAC layer by a terminal, and a cell provided by a first base station and a cell provided by a second base station. It may include at least one or more of the information for.
  • the receiver 1730 may receive a bearer setup response message from the second base station.
  • the bearer establishment response message includes cell identifier information associated with the second base station, second base station cell index information, second base station cell random access channel preamble information, second base station cell system information, second base station cell dedicated MAC layer configuration information, E At least one of E-UTRAN Radio Access Bearers (RABs) acceptance list information and second base station data radio bearer configuration information for the accepted E-RAB may be included.
  • E-UTRAN Radio Access Bearers RABs
  • the receiving unit 1730 may include at least one of cell identifier information, second base station cell index information, second base station cell random access channel preamble information, and second base station cell radio resource configuration information associated with the second base station from the second base station.
  • a secondary cell addition modification response message including a may be received.
  • FIG. 18 is a diagram showing the configuration of another terminal according to another embodiment of the present invention.
  • a user terminal 1800 includes a receiver 1810, a controller 1820, and a transmitter 1830.
  • the controller 1820 controls the overall operation of the terminal according to the transmission of the user plane data through the second base station under the control of the first base station required to carry out the present invention described above.
  • the receiver 1810 receives downlink control information, data, and a message from a first or second base station through a corresponding channel.
  • the transmitter 1830 transmits downlink control information, data, and messages to the first or second base station through the corresponding channel.
  • the controller 1820 may control to add or modify a cell associated with the second base station based on higher layer signaling received from the first base station, and configure a data radio bearer for user plane data transmission.
  • controller 1820 may control the overall operation of the terminal related to the random access procedure for uplink synchronization with the cell associated with the second base station.
  • controller 1820 may control to separately configure the MAC entity for the first base station and the MAC entity for the second base station in the MAC layer.
  • the MAC entity for the second base station may be configured by dividing the scheduling priority processing entity and the multiplexing entity for the radio bearer configured through the second base station.
  • the receiver 1810 may perform higher layer signaling including at least one of cell identifier information, second base station cell index information, and data radio bearer information configured through the second base station for the cell associated with the second base station from the first base station. Can be received.
  • the receiver 1810 may include a cell identification information, a second base station cell system information, a second base station cell random access channel preamble information, and a terminal specific configuration information associated with a second base station for a terminal to access a cell associated with a second base station.
  • a higher layer signaling further including at least one of the information may be received.
  • the data radio bearer information configured through the above-described second base station may include information for distinguishing a first base station and a second base station from a MAC layer by a terminal, and a cell provided by a first base station and a cell provided by a second base station. It may include at least one or more of the information for.
  • the transmitter 1830 may transmit user plane data to the second base station through the data radio bearer.
  • a procedure such as adding / modifying a cell (small cell) associated with a second base station of a terminal or adding / modifying a radio bearer to be configured in a cell (small cell) associated with a second base station It is effective to provide a method and apparatus for controlling the same.

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Abstract

The present invention relates to a method for transmitting a user's plain data in a small cell environment where a terminal is multiply connected to a macro cell and a small cell and an apparatus therefor, and more specifically a method for making a first base station control the transmission of the user's plain data of a terminal includes the steps of: based on at least one of the load information and the measurement report information, determining the transmission of the user's plain data by choosing a wireless bearer constructed through a second base station; transmitting a bearer establishment request message to a second base station; receiving a bearer establishment response message from the second base station; and transmitting an upper layer signaling containing at least one of the cell identification information for the cell associated with the second base station, the cell index information of the second base station, and the data wireless bearer information constructed through the second base station to the terminal.

Description

스몰 셀 환경에서의 사용자 플레인 데이터 전송 방법 및 장치Method and device for transmitting user plane data in small cell environment
본 발명은 단말이 매크로 셀 및 스몰 셀과 다중 연결된 스몰 셀 환경에서의 사용자 플레인 데이터 전송 방법 및 장치에 관한 것이다.The present invention relates to a method and apparatus for transmitting user plane data in a small cell environment in which a terminal is multiplexed with a macro cell and a small cell.
통신 시스템이 발전해나감에 따라 사업체들 및 개인들과 같은 소비자들은 매우 다양한 무선 단말기들을 사용하게 되었다.As communication systems have evolved, consumers, such as businesses and individuals, have used a wide variety of wireless terminals.
현재의 3GPP 계열의 LTE(Long Term Evolution), LTE-Advanced등의 이동 통신 시스템에서는 음성 위주의 서비스를 벗어나 영상, 무선 데이터 등의 다양한 데이터를 송수신할 수 있는 고속 대용량의 통신 시스템이 요구되고 있다.Current mobile communication systems such as Long Term Evolution (LTE), LTE-Advanced, etc. of the 3GPP series require high-speed large-capacity communication systems capable of transmitting and receiving various data such as video and wireless data beyond voice-oriented services.
이러한 고속 대용량의 통신 시스템을 위해서 소형 셀을 활용하여 단말의 용량을 늘릴 수 있는 기술이 요구된다.For such a high-speed large-capacity communication system, a technology for increasing the capacity of a terminal by using a small cell is required.
또한, 매크로 셀 기지국이 스몰 셀 기지국과 논 아이디얼 백홀로 연결된 환경에서, 단말이 스몰 셀을 통해서 사용자 플레인 데이터를 전송하기 위해서는 스몰 셀 및 무선 베어러 설정이 요구된다.In addition, in an environment in which a macro cell base station is connected to a small cell base station by a non-ideal backhaul, a small cell and a radio bearer setup are required for the terminal to transmit user plane data through the small cell.
이 경우, 매크로 셀 기지국과 단말은 스몰 셀 추가/수정 또는 스몰 셀을 제공하는 기지국에 구성될 무선 베어러 추가/수정 등의 설정을 위한 절차 수행이 요구된다.In this case, the macro cell base station and the terminal are required to perform a procedure for setting a small cell addition / modification or a radio bearer addition / modification to be configured in the base station providing the small cell.
전술한 요구에 따라 본 발명은 단말이 스몰 셀 환경에서 사용자 플레인 데이터를 전송하기 위해서 스몰 셀 및/또는 데이터 무선 베어러를 추가/수정하는 방법 및 장치를 제안하고자 한다.In accordance with the above-described demands, the present invention proposes a method and apparatus for adding / modifying a small cell and / or a data radio bearer in order for a terminal to transmit user plane data in a small cell environment.
또한, 본 발명은 제 1 기지국이 단말의 스몰 셀 추가/수정 및/또는 스몰 셀에 구성될 무선 베어러 추가/수정 등의 절차를 제어하는 방법 및 장치를 제안하고자 한다.In addition, the present invention is to propose a method and apparatus for a first base station to control a procedure of adding / modifying a small cell of a terminal and / or adding / modifying a radio bearer to be configured in a small cell.
전술한 과제를 해결하기 위한 본 발명은, 제 1 기지국이 단말의 사용자 플레인 데이터 전송을 제어하는 방법에 있어서, 제 1 기지국의 부하 정보 및 측정 리포트 정보 중 적어도 하나 이상의 정보에 기초하여 제 2 기지국을 통해 구성되는 무선 베어러를 선택하여 사용자 플레인 데이터 전송을 결정하는 단계와 제 2 기지국으로 베어러 설정 요청 메시지를 전송하는 단계와 제 2 기지국으로부터 베어러 설정 응답 메시지를 수신하는 단계 및 단말로 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 전송하는 단계를 포함하는 방법을 제공한다.The present invention for solving the above problems, in the method for the first base station to control the user plane data transmission of the terminal, the second base station based on at least one or more of the load information and the measurement report information of the first base station; Selecting a radio bearer configured to determine user plane data transmission; transmitting a bearer establishment request message to a second base station; receiving a bearer establishment response message from a second base station; And transmitting higher layer signaling comprising at least one of cell identifier information for the cell, second base station cell index information, and data radio bearer information configured through the second base station.
또한, 본 발명은, 단말이 사용자 플레인 데이터를 전송을 제어하는 방법에 있어서, 제 1 기지국으로부터 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 수신하는 단계와 상위계층 시그널링에 기초하여 제 2 기지국에 연관된 셀을 추가 또는 수정하고, 사용자 플레인 데이터 전송을 위한 데이터 무선 베어러를 구성하는 단계를 포함하는 방법을 제공한다.In addition, the present invention, in the method for the terminal to control the user plane data transmission, the cell identifier information, the second base station cell index information and the second base station for the cell associated with the second base station from the first base station is configured Receiving a higher layer signaling including at least one of data radio bearer information, adding or modifying a cell associated with the second base station based on the higher layer signaling, and configuring a data radio bearer for user plane data transmission; It provides a method comprising the steps.
또한, 본 발명은, 단말의 사용자 플레인 데이터 전송을 제어하는 제 1 기지국에 있어서, 제 1 기지국의 부하 정보 및 측정 리포트 정보 중 적어도 하나 이상의 정보에 기초하여 제 2 기지국을 통해 구성되는 무선 베어러를 선택하여 사용자 플레인 데이터 전송을 결정하는 제어부와 제 2 기지국으로 베어러 설정 요청 메시지를 전송하는 송신부와 제 2 기지국으로부터 베어러 설정 응답 메시지를 수신하는 수신부 및 단말로 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 전송하는 송신부를 포함하는 기지국 장치를 제공한다.In addition, the present invention, in the first base station for controlling the user plane data transmission of the terminal, selecting a radio bearer configured through the second base station based on at least one or more of the load information and the measurement report information of the first base station Cell identifier information for a cell associated with a second base station to a control unit for determining user plane data transmission, a transmitter for transmitting a bearer establishment request message to a second base station, a receiver for receiving a bearer establishment response message from a second base station, and a terminal; Provided is a base station apparatus including a transmitter for transmitting higher layer signaling including at least one of information of second base station cell index information and data radio bearer information configured through the second base station.
또한, 본 발명은, 사용자 플레인 데이터를 전송을 제어하는 단말에 있어서, 제 1 기지국으로부터 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 수신하는 수신부와 상위계층 시그널링에 기초하여 제 2 기지국에 연관된 셀을 추가 또는 수정하고, 사용자 플레인 데이터 전송을 위한 데이터 무선 베어러를 구성하는 제어부를 포함하는 단말 장치를 제공한다.In addition, the present invention, the terminal for controlling the transmission of the user plane data, the cell identifier information for the cell associated with the second base station from the first base station, the second base station cell index information and data radio configured through the second base station A receiver for receiving higher layer signaling including at least one of bearer information and a controller for adding or modifying a cell associated with the second base station based on the higher layer signaling and configuring a data radio bearer for user plane data transmission; It provides a terminal device including.
본 발명을 적용할 경우, 단말이 스몰 셀 기지국을 통해서 사용자 플레인 데이터를 전송하기 위해서 스몰 셀 및/또는 데이터 무선 베어러를 추가/수정하는 방법 및 장치를 제공하는 효과가 있다.According to the present invention, there is an effect of providing a method and apparatus for adding / modifying a small cell and / or a data radio bearer in order for a terminal to transmit user plane data through a small cell base station.
또한, 본 발명을 적용할 경우, 매크로 셀 기지국이 단말의 스몰 셀 추가/수정 및/또는 스몰 셀에 구성될 무선 베어러 추가/수정 등의 절차를 제어하는 방법 및 장치를 제공하는 효과가 있다.In addition, when the present invention is applied, there is an effect that the macro cell base station provides a method and apparatus for controlling a procedure such as adding / modifying a small cell and / or adding / modifying a radio bearer to be configured in the small cell.
도 1은 본 발명이 적용될 수 있는 네트워크 구성 시나리오의 일 예를 도시한 도면이다.1 is a diagram illustrating an example of a network configuration scenario to which the present invention can be applied.
도 2는 본 발명이 적용될 수 있는 제 1 기지국과 제 2 기지국의 인터페이스를 통한 사용자 데이터 전송 모델의 일 예를 도시한 도면이다. 2 is a diagram illustrating an example of a user data transmission model through an interface between a first base station and a second base station to which the present invention can be applied.
도 3은 본 발명이 적용될 수 있는 제 2 기지국의 인터페이스를 통한 사용자 데이터 전송 모델의 일 예를 도시한 도면이다. 3 is a diagram illustrating an example of a user data transmission model through an interface of a second base station to which the present invention can be applied.
도 4는 본 발명의 일 실시예에 따른 기지국 및 단말의 동작을 도시한 신호도이다.4 is a signal diagram illustrating operations of a base station and a terminal according to an embodiment of the present invention.
도 5는 본 발명의 다른 실시예에 따른 기지국 및 단말의 동작을 도시한 신호도이다.5 is a signal diagram illustrating operations of a base station and a terminal according to another embodiment of the present invention.
도 6은 본 발명의 또 다른 실시예에 따른 기지국 및 단말의 동작을 도시한 신호도이다.6 is a signal diagram illustrating the operation of a base station and a terminal according to another embodiment of the present invention.
도 7은 본 발명의 또 다른 실시예에 따른 기지국 및 단말의 동작을 도시한 신호도이다.7 is a signal diagram illustrating the operation of a base station and a terminal according to another embodiment of the present invention.
도 8은 본 발명의 또 다른 실시예에 따른 기지국의 동작을 도시한 도면이다.8 is a diagram illustrating the operation of a base station according to another embodiment of the present invention.
도 9는 본 발명의 또 다른 실시예에 따른 단말의 동작을 도시한 도면이다.9 is a diagram illustrating an operation of a terminal according to another embodiment of the present invention.
도 10은 본 발명에 따른 제 2 기지국 인터페이스를 통한 사용자 플레인 데이터 전송 프로토콜의 구조를 일 예를 들어 도시한 도면이다.10 is a diagram illustrating an example of a structure of a user plane data transmission protocol through a second base station interface according to the present invention.
도 11은 본 발명에 따른 제 2 기지국 인터페이스를 통한 사용자 플레인 데이터 전송 프로토콜의 구조를 다른 예를 들어 도시한 도면이다.11 is a diagram illustrating another example of a structure of a user plane data transmission protocol through a second base station interface according to the present invention.
도 12는 본 발명에 따른 제 1 기지국과 제 2 기지국의 Layer2 구조를 일 예를 들어 도시한 도면이다.12 is a diagram illustrating an example of a Layer2 structure of a first base station and a second base station according to the present invention.
도 13은 본 발명에 따른 제 1 기지국과 제 2 기지국의 Layer2 구조를 다른 예를 들어 도시한 도면이다.13 is a diagram illustrating another example of a Layer2 structure of a first base station and a second base station according to the present invention.
도 14는 본 발명에 따른 단말의 Layer2 구조를 일 예를 들어 도시한 도면이다.14 is a diagram illustrating an example of a Layer2 structure of a terminal according to the present invention.
도 15는 본 발명에 따른 단말의 Layer2 구조를 다른 예를 들어 도시한 도면이다.15 illustrates another example of a Layer2 structure of a terminal according to the present invention.
도 16은 본 발명에 따른 단말의 Layer2 구조를 또 다른 예를 들어 도시한 도면이다.16 illustrates another example of a Layer2 structure of a terminal according to the present invention.
도 17은 본 발명의 또 다른 실시예에 따른 기지국의 구성을 도시한 도면이다.17 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
도 18은 본 발명의 또 다른 실시예에 다른 단말의 구성을 도시한 도면이다.18 is a diagram showing the configuration of another terminal according to another embodiment of the present invention.
이하, 본 발명의 일부 실시예들을 예시적인 도면을 통해 상세하게 설명한다. 각 도면의 구성요소들에 참조부호를 부가함에 있어서, 동일한 구성요소들에 대해서는 비록 다른 도면상에 표시되더라도 가능한 한 동일한 부호를 가지도록 하고 있음에 유의해야 한다. 또한, 본 발명을 설명함에 있어, 관련된 공지 구성 또는 기능에 대한 구체적인 설명이 본 발명의 요지를 흐릴 수 있다고 판단되는 경우에는 그 상세한 설명은 생략한다.Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.
본 발명에서의 무선통신시스템은 음성, 패킷 데이터 등과 같은 다양한 통신 서비스를 제공하기 위해 널리 배치된다. 무선통신시스템은 사용자 단말(User Equipment, UE) 및 기지국(Base Station, BS, 또는 eNB)을 포함한다. 본 명세서에서의 사용자 단말은 무선 통신에서의 단말을 의미하는 포괄적 개념으로서, WCDMA 및 LTE, HSPA 등에서의 UE(User Equipment)는 물론, GSM에서의 MS(Mobile Station), UT(User Terminal), SS(Subscriber Station), 무선기기(wireless device) 등을 모두 포함하는 개념으로 해석되어야 할 것이다.The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data, and the like. The wireless communication system includes a user equipment (UE) and a base station (base station, BS, or eNB). In the present specification, a user terminal is a comprehensive concept of a terminal in wireless communication. In addition to user equipment (UE) in WCDMA, LTE, and HSPA, as well as MS (Mobile Station), UT (User Terminal), SS in GSM, It should be interpreted as a concept that includes a subscriber station, a wireless device, and the like.
기지국 또는 셀(cell)은 일반적으로 사용자 단말과 통신하는 지점(station)을 말하며, 노드-B(Node-B), eNB(evolved Node-B), 섹터(Sector), 싸이트(Site), BTS(Base Transceiver System), 액세스 포인트(Access Point), 릴레이 노드(Relay Node), RRH(Remote Radio Head), RU(Radio Unit) 등 다른 용어로 불릴 수 있다.A base station or a cell generally refers to a station that communicates with a user terminal, and includes a Node-B, an evolved Node-B, an Sector, a Site, and a BTS. It may be called other terms such as a base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and the like.
즉, 본 명세서에서 기지국 또는 셀(cell)은 CDMA에서의 BSC(Base Station Controller), WCDMA의 NodeB, LTE에서의 eNB 또는 섹터(싸이트) 등이 커버하는 일부 영역 또는 기능을 나타내는 포괄적인 의미로 해석되어야 하며, 메가셀, 매크로셀, 마이크로셀, 피코셀, 펨토셀 및 릴레이 노드(relay node), RRH, RU 통신범위 등 다양한 커버리지 영역을 모두 포괄하는 의미이다. That is, in the present specification, a base station or a cell is interpreted in a comprehensive sense to indicate some areas or functions covered by a base station controller (BSC) in CDMA, a NodeB in WCDMA, an eNB or a sector (site) in LTE, and the like. It is meant to cover various coverage areas such as mega cell, macro cell, micro cell, pico cell, femto cell and relay node, RRH, RU communication range.
본 명세서에서 사용자 단말과 기지국은 본 명세서에서 기술되는 기술 또는 기술적 사상을 구현하는데 사용되는 두 가지 송수신 주체로 포괄적인 의미로 사용되며 특정하게 지칭되는 용어 또는 단어에 의해 한정되지 않는다. 사용자 단말과 기지국은, 본 발명에서 기술되는 기술 또는 기술적 사상을 구현하는데 사용되는 두 가지(Uplink 또는 Downlink) 송수신 주체로 포괄적인 의미로 사용되며 특정하게 지칭되는 용어 또는 단어에 의해 한정되지 않는다. 여기서, 상향링크(Uplink, UL, 또는 업링크)는 사용자 단말에 의해 기지국으로 데이터를 송수신하는 방식을 의미하며, 하향링크(Downlink, DL, 또는 다운링크)는 기지국에 의해 사용자 단말로 데이터를 송수신하는 방식을 의미한다.In the present specification, the user terminal and the base station are two transmitting and receiving entities used to implement the technology or technical idea described in this specification in a comprehensive sense and are not limited by the terms or words specifically referred to. The user terminal and the base station are two types of uplink or downlink transmitting / receiving subjects used to implement the technology or the technical idea described in the present invention, and are used in a generic sense and are not limited by the terms or words specifically referred to. Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.
무선통신시스템에 적용되는 다중 접속 기법에는 제한이 없다. CDMA(Code Division Multiple Access), TDMA(Time Division Multiple Access), FDMA(Frequency Division Multiple Access), OFDMA(Orthogonal Frequency Division Multiple Access), OFDM-FDMA, OFDM-TDMA, OFDM-CDMA와 같은 다양한 다중 접속 기법을 사용할 수 있다. 본 발명의 일 실시예는 GSM, WCDMA, HSPA를 거쳐 LTE 및 LTE-Advanced로 진화하는 비동기 무선통신과, CDMA, CDMA-2000 및 UMB로 진화하는 동기식 무선 통신 분야 등의 자원할당에 적용될 수 있다. 본 발명은 특정한 무선통신 분야에 한정되거나 제한되어 해석되어서는 아니 되며, 본 발명의 사상이 적용될 수 있는 모든 기술분야를 포함하는 것으로 해석되어야 할 것이다.There is no limitation on the multiple access scheme applied to the wireless communication system. Various multiple access techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM-TDMA, OFDM-CDMA Can be used. One embodiment of the present invention can be applied to resource allocation in the fields of asynchronous wireless communication evolving to LTE and LTE-Advanced through GSM, WCDMA, HSPA, and synchronous wireless communication evolving to CDMA, CDMA-2000 and UMB. The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be construed as including all technical fields to which the spirit of the present invention can be applied.
상향링크 전송 및 하향링크 전송은 서로 다른 시간을 사용하여 전송되는 TDD(Time Division Duplex) 방식이 사용될 수 있고, 또는 서로 다른 주파수를 사용하여 전송되는 FDD(Frequency Division Duplex) 방식이 사용될 수 있다.The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.
또한, LTE, LTE-Advanced와 같은 시스템에서는 하나의 반송파 또는 반송파 쌍을 기준으로 상향링크와 하향링크를 구성하여 규격을 구성한다. 상향링크와 하향링크는, PDCCH(Physical Downlink Control CHannel), PCFICH(Physical Control Format Indicator CHannel), PHICH(Physical Hybrid ARQ Indicator CHannel), PUCCH(Physical Uplink Control CHannel) 등과 같은 제어채널을 통하여 제어정보를 전송하고, PDSCH(Physical Downlink Shared CHannel), PUSCH(Physical Uplink Shared CHannel) 등과 같은 데이터채널로 구성되어 데이터를 전송한다. In addition, in systems such as LTE and LTE-Advanced, a standard is configured by configuring uplink and downlink based on one carrier or a pair of carriers. Uplink and downlink transmit control information through control channels such as Physical Downlink Control CHannel (PDCCH), Physical Control Format Indicator CHannel (PCFICH), Physical Hybrid ARQ Indicator CHannel (PHICH), and Physical Uplink Control CHannel (PUCCH). A data channel is configured such as PDSCH (Physical Downlink Shared CHannel), PUSCH (Physical Uplink Shared CHannel) and the like to transmit data.
본 명세서에서 셀(cell)은 송수신 포인트로부터 전송되는 신호의 커버리지 또는 송수신 포인트(transmission point 또는 transmission/reception point)로부터 전송되는 신호의 커버리지를 가지는 요소반송파(component carrier), 그 송수신 포인트 자체를 의미할 수 있다. In the present specification, a cell means a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.
실시예들이 적용되는 무선통신 시스템은 둘 이상의 송수신 포인트들이 협력하여 신호를 전송하는 다중 포인트 협력형 송수신 시스템(coordinated multi-point transmission/reception System; CoMP 시스템) 또는 협력형 다중 안테나 전송방식(coordinated multi-antenna transmission system), 협력형 다중 셀 통신시스템일 수 있다. CoMP 시스템은 적어도 두 개의 다중 송수신 포인트와 단말들을 포함할 수 있다. A wireless communication system to which embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-antenna transmission scheme in which two or more transmission / reception points cooperate to transmit a signal. antenna transmission system), a cooperative multi-cell communication system. The CoMP system may include at least two multiple transmission / reception points and terminals.
다중 송수신 포인트는 기지국 또는 매크로 셀(macro cell, 이하 'eNB'라 함)과, eNB에 광케이블 또는 광섬유로 연결되어 유선 제어되는, 높은 전송파워를 갖거나 매크로 셀영역 내의 낮은 전송파워를 갖는 적어도 하나의 RRH일 수도 있다.The multiple transmit / receive point is at least one having a high transmission power or a low transmission power in a macro cell region, which is connected to an eNB or a macro cell (hereinafter referred to as an 'eNB') and wired controlled by an optical cable or an optical fiber to an eNB. May be RRH.
이하에서 하향링크(downlink)는 다중 송수신 포인트에서 단말로의 통신 또는 통신 경로를 의미하며, 상향링크(uplink)는 단말에서 다중 송수신 포인트으로의 통신 또는 통신 경로를 의미한다. 하향링크에서 송신기는 다중 송수신 포인트의 일부분일 수 있고, 수신기는 단말의 일부분일 수 있다. 상향링크에서 송신기는 단말의 일부분일 수 있고, 수신기는 다중 송수신 포인트의 일부분일 수 있다. Hereinafter, downlink refers to a communication or communication path from a multiple transmission / reception point to a terminal, and uplink means a communication or communication path from a terminal to multiple transmission / reception points. In downlink, a transmitter may be part of multiple transmission / reception points, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.
이하에서는 PUCCH, PUSCH, PDCCH 및 PDSCH 등과 같은 채널을 통해 신호가 송수신되는 상황을 'PUCCH, PUSCH, PDCCH 및 PDSCH를 전송, 수신한다'는 형태로 표기하기도 한다.Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, and a PDSCH may be described in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, and a PDSCH.'
기지국은 단말들로 하향링크 전송을 수행한다. 기지국은 유니캐스트 전송(unicast transmission)을 위한 주 물리 채널인 물리 하향링크 공유채널(Physical Downlink Shared Channel, PDSCH), 그리고 PDSCH의 수신에 필요한 스케줄링 등의 하향링크 제어 정보 및 상향링크 데이터 채널(예를 들면 물리 상향링크 공유채널(Physical Uplink Shared Channel, PUSCH))에서의 전송을 위한 스케줄링 승인 정보를 전송하기 위한 물리 하향링크 제어채널(Physical Downlink Control Channel, PDCCH)을 전송할 수 있다. 이하에서는, 각 채널을 통해 신호가 송수신 되는 것을 해당 채널이 송수신되는 형태로 기재하기로 한다.The base station performs downlink transmission to the terminals. The base station includes downlink control information such as a physical downlink shared channel (PDSCH), which is a main physical channel for unicast transmission, and scheduling required for reception of the PDSCH and an uplink data channel (eg, For example, a physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission on a physical uplink shared channel (PUSCH) may be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.
모바일 트래픽 폭증에 대처하기 위한 수단으로 저전력 노드를 사용하는 스몰 셀이 고려되고 있다. 저전력 노드는 일반적인 매크로 노드에 비해 낮은 송신(Tx) 전력을 사용하는 노드를 나타낸다. Small cells using low power nodes are being considered as a means to cope with the explosion of mobile traffic. Low power nodes represent nodes that use lower transmit (Tx) power than typical macro nodes.
3GPP Release 11 이전의 캐리어 병합(Carrier Aggregation, 이하 'CA'라 함) 기술에서는 매크로 셀 커버리지 내에서 지리적으로 분산된 안테나인 저전력 RRH(Remote Radio Head)를 사용하여 스몰 셀을 구축할 수 있었다. Prior to 3GPP Release 11, Carrier Aggregation (CA) technology enabled the construction of small cells using low power remote radio heads (RRHs), which are geographically dispersed antennas within macro cell coverage.
그러나, 전술한 CA 기술 적용을 위해 매크로 셀과 RRH 셀은 하나의 기지국의 제어 하에 스케줄링 되도록 구축되며, 이를 위해 매크로 셀 기지국과 RRH 간에는 이상적인 백홀(ideal backhaul)의 구축이 필요했다. 이상적인 백홀이란, 광선로(optical fiber), LOS(Line Of Sight) 마이크로 웨이브(microwave)를 사용하는 전용 점대점 연결과 같이 매우 높은 쓰루풋(throughput)과 매우 적은 지연을 나타내는 백홀을 의미한다. 이와 달리, xDSL(Digital Subscriber Line), Non LOS 마이크로 웨이브와 같이 상대적으로 낮은 쓰루풋(throughput)과 큰 지연을 나타내는 백홀을 비이상적 백홀(non-ideal backhaul)이라 한다.However, in order to apply the above-described CA technology, the macro cell and the RRH cell are constructed to be scheduled under the control of one base station. For this purpose, an ideal backhaul was required between the macro cell base station and the RRH. An ideal backhaul means a backhaul that exhibits very high throughput and very low latency, such as a dedicated point-to-point connection using optical fiber, line of sight (LOS) microwaves. In contrast, backhaul that exhibits relatively low throughput and large delay, such as digital subscriber line (xDSL) and Non LOS microwaves, is called non-ideal backhaul.
전술한 CA 기술을 통해 복수의 서빙 셀들은 단말(User Equipment)에 서비스를 제공하기 위해 병합될 수 있었다. 즉, RRC(Radio Resource Control) 연결(connected) 상태의 단말에 대해 복수의 서빙 셀들이 구성될 수 있으며, 매크로 셀 기지국과 RRH 간에 이상적인 백홀이 구축되는 경우에 매크로 셀과 RRH셀이 함께 서빙 셀로 구성되어 단말에 서비스를 제공 할 수 있었다.Through the above-described CA technology, a plurality of serving cells may be merged to provide a service to a user equipment. That is, a plurality of serving cells may be configured for a UE in a Radio Resource Control (RRC) connected state, and the macro cell and the RRH cell are configured together as a serving cell when an ideal backhaul is established between the macro cell base station and the RRH. Was able to provide services to the terminal.
CA 기술이 구성될 때, 단말은 네트워크와 하나의 RRC 연결(connection)만을 가질 수 있다.When the CA technology is configured, the terminal may have only one RRC connection with the network.
RRC 연결(connection) 설정(establishment)/재설정(re-establishment)/핸드오버에서 하나의 서빙 셀이 NAS 이동성(mobility) 정보(예를 들어, TAI: Tracking Area Identity)를 제공하며, RRC 연결(connection) 재설정/핸드오버에서 하나의 서빙 셀이 시큐리티 입력(security input)을 제공한다. 이러한 셀을 PCell(Primary Cell)이라 한다. PCell은 단지 핸드오버 프로시져와 함께 변경될 수 있다.In RRC connection establishment / reestablishment / handover, one serving cell provides NAS mobility information (e.g., TAI: Tracking Area Identity), and an RRC connection In a reset / handover, one serving cell provides a security input. Such a cell is called a primary cell (PCell). The PCell can only be changed with the handover procedure.
단말 능력들(capabilities)에 따라 SCells(Secondary Cells)이 PCell과 함께 서빙 셀로 구성될 수 있다. SCells의 추가(addition)와 제거(removal)는 RRC에 의해 수행된다. 새로운 SCells을 추가할 때, 전용 RRC 시그널링이 SCells의 모든 요구되는 시스템 정보 송신을 위해 사용된다. 즉, 연결모드(connected mode)에서, 단말은 SCell들로부터 직접 브로드캐스트된 시스템 정보를 획득할 필요가 없다.According to terminal capabilities, SCells (Secondary Cells) may be configured as a serving cell together with a PCell. Additions and removals of SCells are performed by RRC. When adding new SCells, dedicated RRC signaling is used for all required system information transmission of the SCells. That is, in the connected mode, the terminal does not need to acquire system information broadcast directly from the SCells.
PCell과 SCells을 처리하는 하나의 기지국은 물리계층에서 서로 다른 캐리어(DL/UL PCC: Downlink/Uplink Primary Component Carrier, DL/UL SCC: Downlink/Uplink Secondary Component Carrier)를 가지지만 MAC(Medium Access Control) 계층에만 영향을 주며 그 이상의 레이어2(Layer2) 계층(RLC/PDCP)에 대해서는 캐리어 병합기술이 도입되기 이전의 RLC(Radio Link Control, 이하 'RLC'라 함) 및 PDCP(Packet Data Convergence Protocol, 이하 'PDCP'라 함) 계층에 영향을 주지 않는다. 즉, RLC 및 PDCP 계층에서는 CA 동작을 구분할 수 없다. One base station that handles PCell and SCells has different carriers (DL / UL PCC: Downlink / Uplink Primary Component Carrier, DL / UL SCC: Downlink / Uplink Secondary Component Carrier) in the physical layer, but MAC (Medium Access Control) Layer 2 (RLC / PDCP) above only affects the layer, and RLC (Radio Link Control, RLC) and Packet Data Convergence Protocol (PDCP) before carrier aggregation was introduced. Does not affect the layer. That is, the CA operation cannot be distinguished in the RLC and PDCP layers.
또 다른 스몰셀 구축 방법으로 CA 기술 구성에 관계없이 기존 매크로 기지국 계층의 커버리지 하에서 보완적인 저전력 노드(예를 들어, 피코 노드)를 구축할 수 있었다. 즉, 매크로 기지국과 피코 기지국을 구축하는 방법이다. 스몰 셀 구축이 증가될수록 이러한 이종망(heterogeneous) 환경에서의 핸드오버는 매크로 기지국만으로 구축된 망 환경에 비해 크게 증가된다. 따라서, 네트워크에 시그널링 부하와 핸드오버에 따른 잠재적인 무선 링크 실패(radio link failures)를 증가시킬 수 있었다.  Another small cell deployment method could build complementary low power nodes (eg, pico nodes) under the coverage of the existing macro base station layer regardless of the CA technology configuration. That is, it is a method of building a macro base station and a pico base station. As the small cell deployment is increased, the handover in such a heterogeneous environment is greatly increased compared to the network environment constructed only with the macro base station. Thus, potential radio link failures due to signaling load and handover in the network could be increased.
전술한 바와 같이 종래 이동통신망에서는 캐리어 병합 기술을 사용하여 스몰 셀을 구축하기 위해서는 매크로 셀과 스몰 셀이 하나의 기지국의 제어 하에 스케줄링 되어야 했다. 따라서, 매크로 셀 기지국과 스몰셀 기지국 간에 이상적인 백홀(ideal backhaul) 구축이 필요한 문제가 있었다. 이는 매크로 셀 기지국과 스몰 셀 기지국 간의 높은 백홀 구축 비용을 유발할 수 있었으며, 스몰 셀의 확산을 저해하는 요소가 될 수 있었다.As described above, in the conventional mobile communication network, the macro cell and the small cell had to be scheduled under the control of one base station in order to construct a small cell using a carrier aggregation technique. Therefore, there is a problem that an ideal backhaul construction is required between the macro cell base station and the small cell base station. This could induce a high backhaul cost between the macro cell base station and the small cell base station, and could be a factor preventing the spread of the small cell.
또한, 피코 기지국 형태의 스몰 셀 구축은 매크로 셀만으로 구축된 네트워크에 비해 잦은 핸드오버를 유발하여 이에 시그널링 부하 증가와 핸드오버 실패 증가 등의 문제를 야기할 수 있었다.In addition, the construction of a small cell in the form of a pico base station may cause more handover than a network constructed only of a macro cell, thereby causing problems such as an increase in signaling load and an increase in handover failure.
위에서 설명한 문제점을 해결하기 위해 본 발명은 이동통신망에서 매크로 셀 기지국과 스몰 셀 기지국 간에 비이상적인 백홀로 구축된 환경에서 매크로 셀의 제어 하에서 사용자 플레인 트래픽을 효율적으로 스몰 셀로 오프로딩하기 위해 필요한 절차와 관련 장치를 제공하는 것을 목적으로 한다In order to solve the problems described above, the present invention relates to a procedure required for efficiently offloading user plane traffic to a small cell under the control of the macro cell in a non-ideal backhaul environment between the macro cell base station and the small cell base station in a mobile communication network. It is aimed at providing apparatus
이하에서는 단말이 이중 연결을 구성함에 있어서, 단말과 RRC 연결을 형성하고, 핸드오버의 기준이 되는 PCell을 제공하는 기지국 또는 S1-MME를 종단하고, 코어 네트워크에 대해서 모빌리티 앵커(mobility anchor)역할을 하는 기지국을 마스터 기지국 또는 제 1 기지국으로 기재한다. 즉, 마스터 기지국 또는 제 1 기지국은 매크로 셀을 제공하는 기지국일 수 있고, 스몰 셀 간의 이중 연결 상황에서는 어느 하나의 스몰 셀을 제공하는 기지국일 수 있다. Hereinafter, when the UE configures dual connectivity, it forms an RRC connection with the UE, terminates the base station or S1-MME that provides the PCell as a reference for handover, and serves as a mobility anchor for the core network. A base station to be described as a master base station or a first base station. That is, the master base station or the first base station may be a base station providing a macro cell, and may be a base station providing any one small cell in a dual connectivity situation between the small cells.
한편, 이중 연결 환경에서 마스터 기지국과 구별되어 단말에 추가적인 무선 자원을 제공하는 기지국을 세컨더리 기지국 또는 제 2 기지국으로 기재한다.Meanwhile, a base station that is distinguished from a master base station in a dual connectivity environment and provides additional radio resources to a terminal is described as a secondary base station or a second base station.
제 1 기지국(마스터 기지국) 및 제 2 기지국(세컨더리 기지국)은 각각 단말에 적어도 하나 이상의 셀을 제공할 수 있고, 제 1 기지국 및 제 2 기지국은 제 1 기지국과 제 2 기지국 간의 인터페이스를 통해서 연결될 수 있다.The first base station (master base station) and the second base station (secondary base station) may provide at least one cell to the terminal, respectively, and the first base station and the second base station may be connected through an interface between the first base station and the second base station. have.
또한, 이해를 돕기 위하여 제 1 기지국에 연관된 셀을 매크로 셀이라고 기재할 수 있고, 제 2 기지국에 연관된 셀을 스몰 셀이라 기재할 수 있다. 다만, 스몰 셀 클러스터 시나리오에서는 제 1 기지국에 연관된 셀도 스몰 셀로 기재될 수 있다.In addition, a cell associated with the first base station may be referred to as a macro cell, and a cell associated with the second base station may be referred to as a small cell for clarity. However, in the small cell cluster scenario, a cell associated with the first base station may also be described as a small cell.
또한, 이해의 편의를 위해서 제 1 기지국이 제공하는 셀(제 1 기지국에 연관된 셀)을 매크로 셀로 기재하여 설명하고, 제 2 기지국이 제공하는 셀(제 2 기지국에 연관된 셀)을 스몰 셀로 기재하여 설명한다. 다만, 전술한 스몰 셀 간의 이중 연결 상황 또는 스몰 셀 클러스터 시나리오에서도 본 발명이 동일하게 적용될 수 있다.In addition, for convenience of explanation, a cell (cell associated with the first base station) provided by the first base station will be described as a macro cell, and a cell (cell associated with the second base station) provided by the second base station will be described as a small cell. Explain. However, the present invention may be equally applied to the aforementioned dual connectivity between small cells or a small cell cluster scenario.
본 명세서에서 기재하는 제 1 기지국은 마스터 기지국과 동일한 의미로 쓰일 수 있으며, 제 2 기지국은 세컨더리 기지국과 동일한 의미로 사용될 수 있다.The first base station described herein may be used in the same sense as the master base station, and the second base station may be used in the same meaning as the secondary base station.
또한, 본 명세서에서 기재하는 세컨더리 셀 또는 스몰 셀 또는 SCell이라는 용어는 제 2 기지국과 연관된 셀을 의미하며, 마스터 셀 또는 매크로 셀 또는 PCell이라는 용어는 제 1 기지국과 연관된 셀을 의미한다.Also, the term secondary cell or small cell or SCell described herein refers to a cell associated with a second base station, and the term master cell or macro cell or PCell refers to a cell associated with a first base station.
도 1은 본 발명이 적용될 수 있는 네트워크 구성 시나리오의 일 예를 도시한 도면이다.1 is a diagram illustrating an example of a network configuration scenario to which the present invention can be applied.
도 1에서 단말(102)은 매크로 셀 커버리지와 스몰 셀 커버리지 내에 위치한다. 즉, 단말(102)은 매크로 셀 커버리지 내에서 중첩(overlay)된 스몰 셀 커버리지에 동시에 포함될 수 있다. 매크로 셀과 스몰 셀은 서로 다른(different) 캐리어 주파수(carrier frequencies)를 가지며 제 1 기지국(110)과 제 2 기지국(120) 간에는 비이상적인 백홀(non-ideal backhaul)이 구축된다.In FIG. 1, the terminal 102 is located in macro cell coverage and small cell coverage. That is, the terminal 102 may be simultaneously included in the small cell coverage overlapped in the macro cell coverage. The macro cell and the small cell have different carrier frequencies and a non-ideal backhaul is established between the first base station 110 and the second base station 120.
도 1에서 매크로 셀과 스몰 셀은 서로 다른 기지국을 통해 구축되며 제 1 기지국(110)과 제 2 기지국(120) 간에는 인터페이스를 가진다.  In FIG. 1, a macro cell and a small cell are constructed through different base stations and have an interface between the first base station 110 and the second base station 120.
도 1의 시나리오에서 단말(102)은 제 2 기지국(120)만을 통해 데이터를 전송할 수 있다.In the scenario of FIG. 1, the terminal 102 may transmit data only through the second base station 120.
즉, 제 2 기지국(120)이 독립된(stand-alone) 기지국으로 동작하여 제어 플레인(control plane) 데이터를 전송할 수 있다. 따라서, 단말(102)은 제 2 기지국(120)과 하나의 RRC 연결(connection)을 설정할 수 있으며, 하나 또는 그 이상의 SRBs(Signaling Radio Bearers)를 설정할 수 있다. 또한, 사용자 플레인 데이터 전송을 위해 단말(102)은 제 2 기지국(120)과 하나 또는 그 이상의 DRBs(Data Radio Bearers)를 설정할 수 있다. That is, the second base station 120 may operate as a stand-alone base station to transmit control plane data. Accordingly, the terminal 102 may establish one RRC connection with the second base station 120, and may configure one or more signaling radio bearers (SRBs). In addition, the terminal 102 may establish one or more DRBs (Data Radio Bearers) with the second base station 120 for user plane data transmission.
또 다른 방법으로 도 1의 시나리오에서 단말(102)은 제 1 기지국(110)의 제어 하에서(또는 제 2 기지국과 제 1 기지국 간의 협력을 통해서) 제 2 기지국(120)을 통해 사용자 플레인 데이터를 전송할 수 있다. 또는 단말(102)은 제 2 기지국(120)과 제 1 기지국(110)간의 협력을 통한 제어하에서 제 2 기지국(120)을 통해 사용자 플레인 데이터를 전송할 수도 있다.Alternatively, in the scenario of FIG. 1, the terminal 102 transmits user plane data through the second base station 120 under the control of the first base station 110 (or through cooperation between the second base station and the first base station). Can be. Alternatively, the terminal 102 may transmit user plane data through the second base station 120 under cooperative control between the second base station 120 and the first base station 110.
즉, 제어 플레인(control plane) 데이터 전송을 위해 단말(102)은 제 1 기지국(110)과 하나의 RRC 연결(connection)을 설정할 수 있으며, 하나 또는 그 이상의 SRBs(Signaling Radio Bearers)를 설정할 수 있다. 또한, 사용자 플레인 데이터 전송을 위해 단말(102)은 제 2 기지국(120)과 하나 또는 그 이상의 DRBs(Data Radio Bearers)를 설정할 수 있다.That is, the terminal 102 may establish one RRC connection with the first base station 110 and transmit one or more signaling radio bearers (SRBs) for control plane data transmission. . In addition, the terminal 102 may establish one or more DRBs (Data Radio Bearers) with the second base station 120 for user plane data transmission.
도 2는 본 발명이 적용될 수 있는 제 1 기지국과 제 2 기지국의 인터페이스를 통한 사용자 데이터 전송 모델의 일 예를 도시한 도면이다. 2 is a diagram illustrating an example of a user data transmission model through an interface between a first base station and a second base station to which the present invention can be applied.
도 2를 참조하면, 사용자 데이터는 코어망(EPC: Evolved Packet Core) 개체인 S-GW(Serving Gateway)에서 제 1 기지국으로 전달된 후, 제 1 기지국이 제 2 기지국을 통해 단말로 전달할 수 있다.Referring to FIG. 2, user data may be transferred from a serving gateway (S-GW), which is an Evolved Packet Core (EPC) entity, to a first base station, and then the first base station may be transmitted to a terminal through a second base station. .
도 3은 본 발명이 적용될 수 있는 제 2 기지국의 인터페이스를 통한 사용자 데이터 전송 모델의 일 예를 도시한 도면이다. 3 is a diagram illustrating an example of a user data transmission model through an interface of a second base station to which the present invention can be applied.
도 3을 참조하면, 사용자 데이터는 코어망 개체인 S-GW(Serving Gateway)에서 직접 제 2 기지국을 통해 단말로 전달될 수 있다.Referring to FIG. 3, user data may be delivered to a terminal through a second base station directly from a serving gateway (S-GW) which is a core network entity.
도 2 및 도 3에서 실선은 제어 플레인 데이터 전송 경로를, 점선은 사용자 플레인 데이터 전송 경로를 각각 나타낸다. In FIG. 2 and FIG. 3, the solid line indicates the control plane data transmission path and the dotted line indicates the user plane data transmission path.
또한, 도 2 및 도 3에서 도시한 것과 다른 방법으로 단말은 제 1 기지국의 제어 하에서(또는 제 2 기지국과의 협력을 통해서), 제 1 기지국과 제 2 기지국 모두를 통하거나 제 1 기지국만을 통해서 사용자 플레인 데이터를 전송할 수도 있다.2 and 3, the terminal may be controlled under the control of the first base station (or through cooperation with the second base station), through both the first base station and the second base station, or through only the first base station. User plane data may also be transmitted.
즉, 제어 플레인(control plane) 데이터 전송을 위해 단말은 제 1 기지국과 하나의 RRC 연결(connection)을 설정하며, 하나 또는 그 이상의 SRBs(Signaling Radio Bearers)를 설정한다. 또한, 사용자 플레인 데이터 전송을 위해 단말은 제 1 기지국과 제 2 기지국에 하나 또는 그 이상의 DRBs(Data Radio Bearers)를 설정할 수 있다. 또는 사용자 플레인 데이터 전송을 위해 단말은 제 1 기지국만을 통해 하나 또는 그 이상의 DRBs를 설정할 수도 있다.That is, the terminal establishes one RRC connection with the first base station and transmits one or more Signaling Radio Bearers (SRBs) for control plane data transmission. In addition, the UE may configure one or more Data Radio Bearers (DRBs) in the first base station and the second base station for user plane data transmission. Alternatively, the UE may configure one or more DRBs through only the first base station for user plane data transmission.
이하에서는, 단말이 제 1 기지국이 제공하는 셀의 커버리지 또는 제 2 기지국이 제공하는 셀의 커버리지 중 어느 하나의 커버리지에 속하는 경우의 동작을 살펴본다.Hereinafter, an operation when a terminal belongs to any one of coverage of a cell provided by a first base station or coverage of a cell provided by a second base station.
단말은 제 1 기지국 커버리지(예를 들어, 매크로 셀) 하에만 있는 경우에 제 1 기지국만을 통해 모든 데이터를 전송할 수 있다. 즉, 단말은 제어 플레인(control plane) 데이터 전송을 위해 제 1 기지국과 하나의 RRC 연결(connection)을 설정할 수 있으며 하나 또는 그 이상의 SRBs(Signaling Radio Bearers)를 설정할 수 있다. 또한, 단말은 사용자 플레인 데이터 전송을 위해 제 1 기지국과 하나 또는 그 이상의 DRBs(Data Radio Bearers)를 설정할 수 있다.The terminal may transmit all data only through the first base station when it is only under the first base station coverage (eg, macro cell). That is, the terminal may establish one RRC connection with the first base station and control one or more Signaling Radio Bearers (SRBs) for control plane data transmission. In addition, the terminal may configure one or more DRBs (Data Radio Bearers) with the first base station for user plane data transmission.
단말은 제 2 기지국 커버리지(예를 들어, 스몰 셀) 하에만 있는 경우에 제 2 기지국만을 통해 모든 데이터를 전송할 수 있다. 즉, 단말은 제어 플레인(control plane) 데이터 전송을 위해 제 2 기지국과 하나의 RRC 연결(connection)을 설정할 수 있으며 하나 또는 그 이상의 SRBs(Signaling Radio Bearers)를 설정할 수 있다. 또한, 단말은 사용자 플레인 데이터 전송을 위해 제 2 기지국과 하나 또는 그 이상의 DRBs(Data Radio Bearers)를 설정할 수 있다.The terminal may transmit all data only through the second base station when it is only under the second base station coverage (eg, a small cell). That is, the terminal may establish one RRC connection with the second base station and transmit one or more Signaling Radio Bearers (SRBs) for control plane data transmission. In addition, the terminal may configure one or more DRBs (Data Radio Bearers) with the second base station for user plane data transmission.
이와 달리 제 2 기지국이 제 1 기지국의 제어하에서 또는 제 1 기지국과 협력을 통해서 사용자 플레인 데이터를 전송하는 경우가 있을 수 있다. Alternatively, there may be a case where the second base station transmits user plane data under the control of the first base station or in cooperation with the first base station.
이 경우, 단말은 제 1 기지국이 제공하는 셀을 통해서만 RRC 연결을 설정할 수 있다.In this case, the UE may establish an RRC connection only through a cell provided by the first base station.
즉, 단말이 제 2 기지국에 근접해 있더라도, 제 1 기지국이 제공하는 매크로 셀로부터 일정 수준 이상의 신호를 수신할 수 있는 경우, 단말은 제 1 기지국만을 통해서 하나의 RRC 연결(connection)을 설정할 수 있다. 이러한 경우 제 1 기지국이 제공하는 매크로 서빙 셀이 RRC connection 설정(establishment)/재설정(re-establishment)/핸드오버에서 NAS 이동성 정보(e.g. TAI: Tracking Area Identity)와 시큐리티 입력(security input)을 제공하도록 할 수 있다. 즉, 제 1 기지국이 단말과 제 1 기지국 간에 필요한 시그널링을 처리할 수 있으며, 단말과 제 2 기지국 간에 필요한 시그널링도 처리할 수 있다.That is, even if the terminal is close to the second base station, when the terminal can receive a signal of a predetermined level or more from the macro cell provided by the first base station, the terminal may establish one RRC connection (connection) only through the first base station. In this case, the macro serving cell provided by the first base station provides NAS mobility information (eg TAI: Tracking Area Identity) and security input (RAI) in RRC connection establishment / reestablishment / handover. can do. That is, the first base station can process necessary signaling between the terminal and the first base station, and can also process necessary signaling between the terminal and the second base station.
한편, 제 2 기지국이 제공하는 스몰 셀이 제 1 기지국이 제공하는 매크로 셀과 함께 단말에 서비스를 제공하는 경우를 간략히 살펴보면, 단말 능력(capabilities)에 따라 스몰 셀은 매크로 셀과 함께 서빙 셀로 구성될 수 있다. 또는 단말 능력(capabilities)에 따라 스몰 셀은 제 1 기지국의 제어 하에서 세컨더리 셀(Secondary cells, SCells) 또는 서빙 셀로 구성될 수 있다. 또는 단말 능력(capabilities)에 따라 스몰 셀은 제 1 기지국의 제어 하에 사용자 플레인 데이터를 전송하는 세컨더리 셀(Secondary cells, SCells) 또는 서빙 셀로 구성될 수도 있다. 또는 단말 능력(capabilities)에 따라 매크로 셀은 제어 플레인 데이터를 전송하고, 스몰 셀은 사용자 플레인 데이터를 전송하는 세컨더리 셀(Secondary cells, SCells) 또는 서빙 셀로 구성될 수도 있다.Meanwhile, when the small cell provided by the second base station provides a service to the terminal together with the macro cell provided by the first base station, the small cell may be configured as a serving cell along with the macro cell according to the terminal capabilities. Can be. Alternatively, the small cell may be configured as secondary cells (SCells) or serving cells under the control of the first base station according to terminal capabilities. Alternatively, the small cell may be configured as secondary cells (SCells) or serving cells that transmit user plane data under the control of the first base station according to terminal capabilities. Alternatively, the macro cell may transmit control plane data according to terminal capabilities, and the small cell may be configured of secondary cells (SCells) or serving cells that transmit user plane data.
제 2 기지국이 제공하는 스몰 셀을 사용자 플레인 데이터 전송을 위한 서빙 셀 또는 세컨더리 셀로 추가(addition)하거나, 제거(removal)하는 절차는 제 1 기지국을 통한 RRC 시그널링에 의해 수행될 수 있다. 또한, 제 2 기지국을 통해 하나 또는 그 이상의 DRBs(Data Radio Bearers)를 추가하거나 해제하는 절차도 제 1 기지국을 통한 RRC 시그널링에 의해 수행될 수 있다. 제 1 기지국이 제 2 기지국이 제공하는 스몰 셀을 사용자 플레인 데이터 전송을 위한 서빙 셀 또는 세컨더리 셀로 추가하거나, 제 2 기지국을 통해 하나 또는 그 이상의 DRBs를 추가하도록 결정하면 제 1 기지국은 RRC 시그널링을 통해 제 2 기지국이 제공하는 스몰 셀의 모든 요구되는 시스템 정보를 송신할 수 있다. 즉, 연결모드(connected mode)에서, 단말은 제 2 기지국이 제공하는 스몰 셀로부터 직접 브로드캐스트된 시스템 정보를 획득할 필요가 없을 수 있다.The procedure of adding or removing the small cell provided by the second base station to the serving cell or the secondary cell for user plane data transmission may be performed by RRC signaling through the first base station. In addition, a procedure of adding or releasing one or more DRBs (Data Radio Bearers) through the second base station may also be performed by RRC signaling through the first base station. If the first base station decides to add the small cell provided by the second base station as a serving cell or secondary cell for user plane data transmission, or to add one or more DRBs through the second base station, the first base station uses RRC signaling. All required system information of the small cell provided by the second base station can be transmitted. That is, in the connected mode, the terminal may not need to acquire system information broadcasted directly from the small cell provided by the second base station.
이하에서는, 도 1과 같이 단말이 매크로 셀과 스몰 셀 모두의 커버리지 내에 있을 때, 매크로 셀을 선택하는 몇 가지 방법에 대해서 간략히 설명한다.Hereinafter, some methods for selecting a macro cell when the terminal is within the coverage of both the macro cell and the small cell as shown in FIG. 1 will be briefly described.
- 시스템 정보에 스몰 셀 식별정보를 포함하여 브로드캐스트하는 방법.A method of broadcasting including the small cell identification information in the system information.
셀 선택을 위해 단말의 NAS(Non Access Stratum) 계층은 selected PLMN(Public Land Mobile Network) 그리고 equivalent PLMN을 식별한다. 단말은 E-UTRA(Evolved Universal Terrestrial Access) 주파수 밴드들을 검색(search)하고 각각의 캐리어 주파수에 대해 가장 강한(strongest) 셀을 식별한다. 단말은 PLMN을 식별하기 위해 셀 시스템 정보를 읽는다. 이때, 셀 시스템 정보에 스몰 셀 식별정보를 포함한 경우 단말은 그러한 셀을 스몰 셀로 식별하고, 셀 선택을 위한 가용한 매크로 셀이 있는 경우 매크로 셀을 선택하도록 할 수 있다.For the cell selection, the NAS (Non Access Stratum) layer of the terminal identifies the selected Public Land Mobile Network (PLMN) and the equivalent PLMN. The terminal searches for Evolved Universal Terrestrial Access (E-UTRA) frequency bands and identifies the strongest cell for each carrier frequency. The terminal reads cell system information to identify the PLMN. In this case, when the cell system information includes the small cell identification information, the terminal may identify such a cell as the small cell and select the macro cell when there is an available macro cell for cell selection.
이를 위해 제 2 기지국에서 스몰 셀 관련 정보를 시스템 정보로 브로드캐스트한다. 제 2 기지국은 단말이 제 2 기지국이 제공하는 스몰 셀 인지를 구별하기 위한 스몰 셀 구별정보(예를 들어, 제 1 기지국의 제어 하에서 단말과 사용자 플레인 데이터를 전송할 수 있는 셀임을 구별하기 위한 정보 또는 스몰 셀 지시(indication)정보)를 시스템정보(예를 들어, SIB1)로 브로드캐스트한다. 단말은 이러한 정보를 이용하여 해당 셀이 제 2 기지국이 제공하는 스몰 셀 인지 식별할 수 있다. 전술한 스몰 셀 식별정보는 제 1 기지국의 제어 하에서 단말과 사용자 플레인 데이터를 전송할 수 있는 셀임을 구별하기 위한 정보로 스몰 셀 또는 스몰 셀이 아님을 나타내는 스몰 셀 지시(Indication) 정보, 스몰셀 ID 정보, 셀 유형 정보 중 적어도 하나 이상의 정보를 사용할 수 있다.To this end, the second base station broadcasts the small cell related information as system information. The second base station is a small cell identification information for identifying whether the terminal is a small cell provided by the second base station (for example, information for distinguishing that the cell can transmit the user plane data with the terminal under the control of the first base station or Small cell indication information) is broadcast as system information (eg, SIB1). The terminal may identify whether the corresponding cell is a small cell provided by the second base station using this information. The above-described small cell identification information is information for distinguishing that the UE and the user plane data can be transmitted under the control of the first base station. The small cell identification information indicating the small cell or the small cell is not the small cell or the small cell ID information. At least one of cell type information may be used.
- 스몰 셀에 캠프온(camp on)이 허용되지 않도록 셀 금지(cell barred)를 설정하는 방법.How to set cell barred such that camp on is not allowed for small cells.
제 2 기지국은 시스템정보블락타입1(SystemInformationBlockType1)에 표시되는 셀 접속관련 정보(Cell Access Related Info)를 이용하여 단말이 스몰 셀에 캠프온하지 못하도록 할 수 있다. 즉, 셀 금지(cell Barred) 정보를 "barred"로 설정함으로써 스몰 셀을 선택하지 않도록 할 수 있다. The second base station may prevent the terminal from camping on the small cell by using the cell access related information displayed in the system information block type 1 (SystemInformationBlockType1). That is, by setting the cell barred information to "barred", it is possible to prevent the small cell from being selected.
- 스몰 셀 사용주파수에 대해서는 셀 선택 후보로 포함하지 않도록 하는 방법.A method of not including the small cell frequency as a cell selection candidate;
단말은 가용한 매크로 셀 사용 주파수에 대해 셀 선택을 위한 검색(search)을 수행하고 가용한 매크로 셀이 없는 경우에만 스몰 셀 사용주파수에 대해 셀 선택을 위한 검색을 수행하도록 하거나, 스몰 셀 사용주파수에 대해 셀 선택을 위한 검색을 하지 않도록 할 수 있다. 이를 위해 스몰 셀로 사용되는 주파수에 대한 정보를 제 1 기지국의 시스템정보를 통하거나 제 2 기지국의 시스템정보를 통해 브로드캐스트할 수 있다. 또는 단말 내부의 USIM 등에 구성할 수 있다.The UE performs a search for cell selection on available macro cell use frequencies and performs a search for cell selection on a small cell use frequency only when there is no available macro cell, or on a small cell use frequency. You can disable searching for cell selection. To this end, the information on the frequency used as the small cell may be broadcast through the system information of the first base station or through the system information of the second base station. Or it can be configured in the USIM inside the terminal.
- 스몰 셀을 선택한 경우 매크로 셀로 셀 선택을 변경하도록 하는 방법.How to change the cell selection to macro cell when small cell is selected.
기존 셀 선택 방법을 이용하여 스몰 셀을 선택한 경우, 단말 또는 제 2 기지국은 셀 리셀렉션(cell reselection) 절차를 개시하도록 하여 매크로 셀을 선택하도록 할 수 있다. 단말이 매크로 셀을 리셀렉션 하도록 하기 위해, 제 1 기지국 및/또는 제 2 기지국은 시스템 정보를 통해 매크로 셀 주파수를 셀 리셀렉션 우선순위 주파수로 설정하여 브로드캐스트 할 수 있다. 다른 방법으로 제 1 기지국 및/또는 제 2 기지국은 RRC 연결 해제(Connection Release) 메시지 또는 RRC 연결 재구성(Connection Reconfiguration) 메시지에 매크로 셀 주파수를 리셀렉션 우선순위 주파수로 설정할 수 있는 정보를 포함하여 전송할 수 있다. Inter-frequency 셀 리셀렉션은 단말이 캠프 온 하고자 하는 가용한 가장 높은 우선순위 주파수(highest priority frequency available)의 절대 우선순위에 기반한다. 따라서 셀 리셀렉션을 통해 매크로 셀에서 스몰 셀로의 셀 리셀렉션을 수행할 수 있다. When the small cell is selected using the existing cell selection method, the terminal or the second base station may initiate a cell reselection procedure to select the macro cell. In order for the terminal to reselect the macro cell, the first base station and / or the second base station may broadcast the macro cell frequency by setting the cell reselection priority frequency through system information. Alternatively, the first base station and / or the second base station may transmit the RRC connection release message or the RRC connection reconfiguration message by including information for setting the macro cell frequency as the reselection priority frequency. have. Inter-frequency cell reselection is based on the absolute priority of the highest priority frequency available that the UE wants to camp on. Therefore, the cell reselection may be performed from the macro cell to the small cell through the cell reselection.
- RRC 연결(Connected) 상태에서 매크로 셀로 핸드오버 하는 방법.How to handover to a macro cell in an RRC connected state.
스몰 셀 선택 후 제 2 기지국과 RRC 연결(Connection)을 설정하여 RRC 연결 상태에 있는 단말에 대해 제 2 기지국은 핸드오버 절차를 수행하여 매크로 셀과 RRC 연결(Connection)을 맺도록 할 수 있다. 다른 방법으로 스몰 셀 선택 후 제 2 기지국과 RRC 연결(Connection)을 설정하여 RRC 연결 상태에 있는 단말에 대해 제 2 기지국은 RRC 연결 해제(Connection Release) 메시지에 매크로 셀을 선택하기 위해 필요한 정보를 포함함으로써 단말이 매크로 셀을 선택하도록 할 수도 있다. After selecting the small cell, the second base station may establish an RRC connection with the second base station so as to establish an RRC connection with the macro cell by performing a handover procedure for the UE in the RRC connected state. Alternatively, after selecting the small cell, the second base station includes the information necessary for selecting the macro cell in the RRC connection release message for the terminal in the RRC connection state by establishing an RRC connection with the second base station. By doing so, the terminal may select the macro cell.
전술한 방법 등을 통해서 매크로 셀을 선택한 단말이 RRC 연결(Connection)을 설정(establish)하고자 하거나, 매크로 셀에서 RRC 아이들(IDLE) 상태의 단말이 RRC 연결(Connection)을 설정하고자 할 때, 단말은 스몰 셀을 발견/식별(discovery/identification)하여 사용자 플레인 데이터 전송을 위한 스몰 셀 추가 및 DRBs를 설정할 수 있다. 또는 단말은 발견/식별된 스몰 셀을 이용하여 사용자 플레인 데이터 전송을 위한 스몰 셀 추가 및 DRBs를 설정할 수 있다. 또는 단말은 스몰 셀 발견/식별에 따른 측정 리포트에 기반하여 사용자 플레인 데이터 전송을 위해 스몰 셀을 추가하여 DRBs를 설정할 수 있다.  When the terminal selecting the macro cell attempts to establish an RRC connection through the above-described method or the like, or when the terminal in the RRC idle state in the macro cell wants to set up the RRC connection, the terminal Small cell addition and DRBs may be configured for user plane data transmission by discovering / identifying small cells. Alternatively, the UE may configure small cell addition and DRBs for user plane data transmission using the discovered / identified small cell. Alternatively, the terminal may configure DRBs by adding a small cell for transmitting user plane data based on the measurement report according to the small cell discovery / identification.
또한, 단말이 제 1 기지국과 RRC 연결(connection) 설정 프로시져를 성공적으로 완료한 후 또는 단말이 제 1 기지국과 RRC 연결(Connection)을 설정하여 RRC 연결 상태에서, 단말은 스몰 셀을 발견/식별(discovery/identification)하 여 사용자 플레인 데이터 전송을 위한 스몰 셀 추가 및 DRBs를 설정할 수 있다. 또는 단말은 발견/식별된 스몰 셀을 이용하여 사용자 플레인 데이터 전송을 위한 스몰 셀 추가 및 DRBs를 설정할 수 있다. 또는 단말은 스몰셀 발견/식별에 따른 측정 리포트에 기반하여 사용자 플레인 데이터 전송을 위해 스몰 셀을 추가하여 DRBs를 설정할 수도 있다. In addition, after the UE successfully completes an RRC connection establishment procedure with the first base station or the UE establishes an RRC connection with the first base station, in the RRC connection state, the UE discovers / identifies a small cell ( discovery / identification) may be used to add small cells and DRBs for user plane data transmission. Alternatively, the UE may configure small cell addition and DRBs for user plane data transmission using the discovered / identified small cell. Alternatively, the terminal may configure DRBs by adding a small cell for transmitting user plane data based on the measurement report according to the small cell discovery / identification.
도 1과 같이 제 1 기지국이 제공하는 매크로 셀과 제 2 기지국이 제공하는 스몰 셀 간에 서로 다른 캐리어 주파수를 사용할 때 다음과 같은 방법을 이용하여 사용자 플레인 데이터 전송이 가능한 스몰 셀을 발견(discovery) 또는 식별(identification)할 수 있다.When using different carrier frequencies between the macro cell provided by the first base station and the small cell provided by the second base station as shown in FIG. 1, a small cell capable of transmitting user plane data can be discovered using the following method; Identification can be done.
- 기존 3GPP 규격을 이용하는 방법.How to use existing 3GPP specifications.
매크로 셀과 다른 캐리어 주파수를 사용하는 스몰 셀을 감지하기 위해 3GPP 표준 문서(E-UTRAN Requirements for support of radio resource management)에 명시된 측정 룰과 측정 갭 패턴을 사용하여 inter-frequency 측정을 수행하여 스몰 셀을 감지할 수 있다. 예를 들어, 기존 표준화된 측정 갭 패턴은 6ms의 측정 갭과 40ms 및 80ms 중 하나의 갭 주기(gap periodicity)를 가지고 있다. 단말은 특정한 임계값 T1 보다 더 강한 신호(예를 들어, RSRP: Reference Signal Received Power, RSRQ: Reference Signal Received Quality)를 가진 스몰 셀을 감지하면 해당 스몰 셀에 대한 측정 정보를 리포팅할 수 있다.To detect small cells with different carrier frequencies than macro cells, small cells are made by performing inter-frequency measurements using the measurement rules and measurement gap patterns specified in the 3GPP standard document (E-UTRAN Requirements for support of radio resource management). Can be detected. For example, the existing standardized measurement gap pattern has a measurement gap of 6 ms and a gap periodicity of 40 ms and 80 ms. When the UE detects a small cell having a stronger signal (eg, RSRP: Reference Signal Received Power, RSRQ: Reference Signal Received Quality) than a specific threshold T1, the terminal may report measurement information on the corresponding small cell.
- 측정주기를 더 길게 하는 방법.-To make the measurement cycle longer.
단말의 배터리 소모를 감소시키기 위해 inter-frequency 측정에 대해서는 측정 주기를 기존의 측정 주기보다 더 길게하는 방법을 사용하여 스몰 셀을 감지할 수도 있다. 효율적인 스몰 셀 감지를 위해 inter-frequency 측정에 대해 전술한 갭 주기(40ms 및 80ms 중 하나)를 더 길게 할 수 있다. 단말은 특정한 임계값 T1 보다 더 강한 신호(예를 들어, RSRP: Reference Signal Received Power, RSRQ: Reference Signal Received Quality)를 가진 스몰 셀을 감지하면 해당 스몰 셀에 대한 측정 정보를 리포팅할 수 있다.In order to reduce battery consumption of the UE, the small cell may be detected by using a method in which the measurement period is longer than the conventional measurement period for the inter-frequency measurement. The above-mentioned gap period (one of 40ms and 80ms) can be made longer for inter-frequency measurements for efficient small cell sensing. When the UE detects a small cell having a stronger signal (eg, RSRP: Reference Signal Received Power, RSRQ: Reference Signal Received Quality) than a specific threshold T1, the terminal may report measurement information on the corresponding small cell.
- 측정주기를 더 짧게 하는 방법.-Shorter measuring cycles.
단말이 RRC 연결(Connection)을 설정하고자 할 때, 빠른 스몰 셀 감지를 위해 inter-frequency 측정에 대해서는 측정 주기를 기존의 측정 주기보다 더 짧게 하는 방법을 사용하여 스몰 셀을 감지할 수도 있다. 예를 들어, 스몰 셀 감지를 위해 inter-frequency 측정에 대해 전술한 갭 주기(40ms 및 80ms 중 하나)를 더 짧게 하거나 또는 갭 어시스턴스(assistance) 없이 측정을 하도록 할 수 있다. 단말은 특정한 임계값 T1 보다 더 강한 신호(예를 들어, RSRP: Reference Signal Received Power, RSRQ: Reference Signal Received Quality)를 가진 스몰 셀을 감지하면 해당 스몰 셀에 대한 측정 정보를 리포팅할 수 있다.When the UE wants to establish an RRC connection, the small cell may be detected by using a method in which the measurement period is shorter than the conventional measurement period for inter-frequency measurement for fast small cell detection. For example, the gap period (one of 40 ms and 80 ms) described above may be shorter for inter-frequency measurement for small cell sensing, or the measurement may be performed without gap assistance. When the UE detects a small cell having a stronger signal (eg, RSRP: Reference Signal Received Power, RSRQ: Reference Signal Received Quality) than a specific threshold T1, the terminal may report measurement information on the corresponding small cell.
제 1 기지국을 통한 RRC 연결(connection) 설정(establishment)은 SRB1(Signaling Radio Bearer 1) 설정을 포함한다. 제 1 기지국은 S1 연결 설정을 완료하기 전에 RRC 연결 설정을 완료할 수 있다. 즉, MME로부터 단말 컨텍스트(context) 정보를 수신하기 전에 RRC 연결 설정을 완료할 수 있다. The RRC connection establishment through the first base station includes a signaling radio bearer 1 (SRB1) configuration. The first base station may complete the RRC connection setup before completing the S1 connection setup. That is, RRC connection setup may be completed before receiving UE context information from the MME.
결과적으로 AS 시큐리티는 최초 RRC 연결 단계 동안에는 액티베이트되지 않는다. 이러한 최초 RRC 연결 단계 동안, 제 1 기지국은 단말에게 측정 리포팅을 구성할 수 있다.As a result, AS security is not activated during the initial RRC connection phase. During this initial RRC connection step, the first base station may configure measurement reporting to the terminal.
제 1 기지국은 MME로부터 단말 컨텍스트를 수신하면, 최초 시큐리티 액티베이션 프로시져를 이용하여 시큐리티(암호화(ciphering)와 무결성 보호(integrity protection))를 액티베이트(activate) 할 수 있다. 시큐리티를 액티베이트 하기 위한 RRC 메시지는 무결성 보호가 되어 있는 반면에 암호화는 프로시져가 완료된 후에 시작된다.When the first base station receives the terminal context from the MME, the first base station can activate security (ciphering and integrity protection) using an initial security activation procedure. RRC messages for activating security are integrity protected, while encryption begins after the procedure is completed.
제 1 기지국은 최초 시큐리티 액티베이션 프로시져를 개시한 후에, SRB2와 DRBs 설정을 개시한다. 즉, 제 1 기지국은 단말로부터 최초 시큐리티 액티베이션의 확인(confirmation)을 수신하기 전에 이를 할 수도 있다. 제 1 기지국은 SRB2와 DRBs를 설정하기 위해 RRC 연결 재구성(connection reconfiguration) 메시지를 사용할 수 있다. 이때, DRBs는 제 2 기지국을 통한 사용자 플레인 데이터 전송을 위한 DRBs 일 수 있다. 또는 DRBs는 제 1 기지국과 제 2 기지국을 통한 사용자 플레인 데이터 전송을 위한 DRBs 일 수도 있다. 전술한 메시지는 암호화와 무결성 보호를 모두 적용한다.After initiating the initial security activation procedure, the first base station initiates SRB2 and DRBs setup. That is, the first base station may do this before receiving confirmation of the initial security activation from the terminal. The first base station may use an RRC connection reconfiguration message to configure SRB2 and DRBs. In this case, the DRBs may be DRBs for user plane data transmission through the second base station. Alternatively, the DRBs may be DRBs for user plane data transmission through the first base station and the second base station. The above message applies both encryption and integrity protection.
제 1 기지국은 최초 시큐리티 액티베이션 프로시져를 개시한 후에 임의의 단말 또는 캐리어 병합(CA)를 지원하는 단말 또는 제 1 기지국의 제어 하에서 제 2 기지국을 통해 사용자 플레인 데이터를 전송을 지원하는 단말에 대해 제 2 기지국이 제공하는 스몰 셀을 구성할 수 있다. 즉, 제 1 기지국은 연결 설정 동안 최초로 구성된 제 1 기지국이 제공하는 매크로 셀(또는 PCell)에 더해 제 2 기지국이 제공하는 스몰 셀을 구성할 수도 있다. 스몰 셀은 다운링크 및 업링크 무선 자원을 제공하여 사용자 플레인 데이터를 전송하는데 사용된다. 일 예로, 제 1 기지국은 전술한 스몰 셀을 추가, 수정 또는 제거하기 위해 RRC 연결 재구성(connection reconfiguration) 메시지를 사용할 수 있다. After the first base station initiates the initial security activation procedure, the second base station may transmit a second terminal to the terminal supporting user plane data transmission through the second base station under the control of the first base station or any terminal or carrier supporting carrier aggregation (CA). The small cell provided by the base station can be configured. That is, the first base station may configure a small cell provided by the second base station in addition to the macro cell (or PCell) provided by the first base station initially configured during connection establishment. Small cells are used to transmit user plane data by providing downlink and uplink radio resources. For example, the first base station may use an RRC connection reconfiguration message to add, modify or remove the aforementioned small cell.
이하에서는, 본 발명의 일 실시예에 따른 제 1 기지국이 제 2 기지국을 통해서 사용자 플레인 데이터를 전송하기 위한 방법을 구체적으로 설명한다. 즉, 본 발명의 일 실시예에 따른 제 1 기지국이 제 2 기지국을 통해 사용자 플레인 데이터를 전송하기 위해 제 2 기지국이 제공하는 스몰 셀을 추가, 수정 또는 제거하거나 제 2 기지국을 통해 DRBs를 추가, 수정 또는 제거하는 절차에 대해서 설명한다.Hereinafter, a method for transmitting user plane data through a second base station by a first base station according to an embodiment of the present invention will be described in detail. That is, according to an embodiment of the present invention, the first base station adds, modifies, or removes a small cell provided by the second base station to transmit user plane data through the second base station, or adds DRBs through the second base station. The procedure for correcting or removing is described.
제 1 실시예: 스몰 셀 추가/수정/제거와 제 2 기지국을 통한 DRBs 추가/수정/제거를 하나의 프로시저로 수행하는 방법.First Embodiment: A method of adding / modifying / removing small cells and adding / modifying / removing DRBs through a second base station as a procedure.
도 4는 본 발명의 일 실시예에 따른 기지국 및 단말의 동작을 도시한 신호도이다.4 is a signal diagram illustrating operations of a base station and a terminal according to an embodiment of the present invention.
본 발명의 일 실시예에 따른 제 1 기지국은 단말의 사용자 플레인 데이터 전송을 제어하는 방법에 있어서, 제 1 기지국의 부하 정보 및 측정 리포트 정보 중 적어도 하나 이상의 정보에 기초하여 제 2 기지국을 통해 구성되는 무선 베어러를 선택하여 사용자 플레인 데이터 전송을 결정하는 단계와 제 2 기지국으로 베어러 설정 요청 메시지를 전송하는 단계와 제 2 기지국으로부터 베어러 설정 응답 메시지를 수신하는 단계 및 단말로 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 전송하는 단계를 포함할 수 있다.In a method of controlling user plane data transmission of a terminal, a first base station according to an embodiment of the present invention is configured through a second base station based on at least one or more of load information and measurement report information of the first base station. Selecting a radio bearer to determine user plane data transmission; transmitting a bearer establishment request message to a second base station; receiving a bearer establishment response message from a second base station; and a terminal for a cell associated with the second base station. The method may include transmitting higher layer signaling including at least one of cell identifier information, second base station cell index information, and data radio bearer information configured through the second base station.
도 4를 참조하여 본 발명의 일 실시예에 따른 사용자 플레인 데이터 전송을 제어하는 방법에 대해서 각 단계별로 구체적으로 설명한다.A method of controlling user plane data transmission according to an embodiment of the present invention will be described in detail with reference to FIG. 4.
제 1 기지국(401)은 측정 리포팅 정보를 수신하여, 제 2 기지국에 연관된 셀의 무선 베어러를 통한 사용자 플레인 데이터 전송을 결정하는 단계를 포함한다(S415).The first base station 401 includes receiving measurement reporting information and determining user plane data transmission through a radio bearer of a cell associated with the second base station (S415).
즉, 제 1 기지국(401)은 RRC 연결 상태에 있는 단말(403)에 대해 제 2 기지국(402)을 통한 사용자 플레인 데이터를 전송하기 위해 스몰 셀을 추가, 수정 또는 제거하거나 제 2 기지국을 통해 DRBs를 추가, 수정 또는 제거하는 절차를 결정할 수 있다(S415).That is, the first base station 401 adds, modifies, or removes small cells or transmits DRBs through the second base station to transmit user plane data through the second base station 402 to the terminal 403 in an RRC connection state. It may determine the procedure to add, modify or remove (S415).
일 예로, 제 1 기지국(401)은 MME로부터 수신된 이니셜 컨텍스트 셋업 요청(Initial Context Setup Request) 메시지 내의 정보(예를 들어, E-RAB Level QoS 파라미터, 단말 캐퍼빌리티)를 이용하여 제 1 기지국(401)을 통해 서비스할 DRB와 제 2 기지국(402)을 통해 서비스할 DRB를 결정할 수 있다.For example, the first base station 401 may use a first base station (eg, an E-RAB Level QoS parameter, terminal capability) in the initial context setup request message received from the MME. The DRB to serve through 401 and the DRB to serve through the second base station 402 may be determined.
다른 예로, 제 1 기지국(401)은 단말(403)로부터 수신될 수 있는 측정 리포팅 정보 및 제 1 기지국의 데이터 부하 정보 중 적어도 하나 이상의 정보에 기초하여 결정할 수도 있다(S415). 즉, 제 1 기지국(401)을 통해 서비스할 DRB와 제 1 기지국(401) 및 제 2 기지국(402)을 통해 서비스할 DRB를 결정할 수 있다.As another example, the first base station 401 may determine based on at least one or more of measurement reporting information that can be received from the terminal 403 and data load information of the first base station (S415). That is, the DRB to be serviced through the first base station 401 and the DRB to be serviced through the first base station 401 and the second base station 402 may be determined.
제 1 기지국(401)은 결정에 따라 제 2 기지국(402)으로 사용자 플레인 데이터 전송을 위한 베어러 설정 시그널링 절차를 개시할 수 있다. 즉, 제 1 기지국(401)은 E-RAB별로 QoS 파라미터(QCI, Allocation and Retention Priority, GBR QoS)에 기초하여 제 1 기지국의 부하, 측정 리포팅 정보 등을 고려하여 제 2 기지국을 통해(또는 제 1 및 제 2 기지국을 통해) 전송하고자 하는 E-RAB를 선택할 수 있다. 일 예를 들어, GBR 베어러 또는 특정 QCI 또는 특정한 Allocation and Retention Priority값을 가진 E-RAB는 제 1 기지국(401)을 통해 전송하고 제 2 기지국(402)으로 DRB설정을 요청하지 않을 수 있다. 또는 다른 예로, 인터넷 트래픽을 위한 non-GBR 베어러 또는 다른 특정 QCI 또는 다른 특정한 Allocation and Retention Priority값을 가진 E-RAB는 제 2 기지국을 통해 전송하도록 DRB설정을 요청할 수도 있다. 또는 제 1 기지국 및 제 2 기지국을 통해 전송하기 위해 DRB설정을 요청할 수도 있다.The first base station 401 may initiate a bearer setup signaling procedure for user plane data transmission to the second base station 402 according to the determination. That is, the first base station 401 may determine the load, measurement reporting information, etc. of the first base station based on QoS parameters (QCI, Allocation and Retention Priority (GBR QoS)) for each E-RAB, and / or through the second base station (or the first base station). E-RAB to be transmitted) can be selected). For example, an E-RAB having a GBR bearer or a specific QCI or a specific Allocation and Retention Priority value may be transmitted through the first base station 401 and may not request DRB establishment from the second base station 402. Or as another example, an E-RAB with a non-GBR bearer or other specific QCI or other specific Allocation and Retention Priority value for Internet traffic may request DRB establishment to transmit via the second base station. Alternatively, the DRB may be requested for transmission through the first base station and the second base station.
제 1 기지국(401)은 제 2 기지국(402)을 통한 사용자 플레인 데이터 전송이 결정되면, 제 2 기지국(402)으로 베어러 설정 요청 메시지를 전송할 수 있다(S420).When the user plane data transmission is determined through the second base station 402, the first base station 401 may transmit a bearer setup request message to the second base station 402 (S420).
일 예를 들어 설명하면, 제 1 기지국(401)은 제 2 기지국을 통한 사용자 플레인 데이터 전송을 결정하면(예를 들어, 스몰 셀을 추가/수정 또는 스몰 셀에 DRBs를 추가/수정 또는 스몰 셀을 추가하여 DRBs를 추가/수정을 결정하면) 전술한 시큐리티 액티베이션 프로시져를 개시하기 전 또는 후에 제 2 기지국(402)으로 사용자 플레인 데이터 전송을 위한 베어러 설정 요청 메시지를 전송한다(S420).As an example, when the first base station 401 determines user plane data transmission through the second base station (for example, add / modify a small cell or add / modify a small cell or DRBs to a small cell) In addition, if it is determined to add / modify DRBs), a bearer setup request message for user plane data transmission is transmitted to the second base station 402 before or after the aforementioned security activation procedure is initiated (S420).
다른 예로, 제 1 기지국(401)은 단말(403)이 RRC 연결(Connected) 상태에 있을 때 제 2 기지국(402)을 통한 사용자 플레인 데이터 전송을 결정하면, 사용자 플레인 데이터 전송을 위한 베어러 설정 요청 메시지를 보낼 수 있다(S420).As another example, when the first base station 401 determines user plane data transmission through the second base station 402 when the terminal 403 is in an RRC connected state, a bearer setup request message for user plane data transmission is determined. Can be sent (S420).
본 발명의 일 실시예에 따른 베어러 설정 요청 메시지는, 제 1 기지국 단말 X2AP(X2 application protocol) 식별자 정보, 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보, 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate) 및 E-RABs(E-UTRAN Radio Access Bearers) 셋업 리스트 정보 중 적어도 하나 이상의 정보를 포함할 수 있다. 이 외에도 아래에서 설명하는 정보들을 포함할 수 있다.Bearer setup request message according to an embodiment of the present invention, the first base station terminal X2AP (X2 application protocol) identifier information, the cell identifier information associated with the second base station, the second base station cell index information, the terminal maximum bit rate (UE) Aggregate Maximum Bit Rate) and E-RABs (E-UTRAN Radio Access Bearers) setup list information may include at least one or more information. In addition, the information described below may be included.
구체적으로 일 예를 들면, 제 2 기지국(402)을 통한 사용자 플레인 데이터 전송을 위한 베어러 설정 요청 메시지는 다음 중 하나 이상의 정보를 포함할 수 있다.Specifically, for example, the bearer establishment request message for user plane data transmission through the second base station 402 may include one or more of the following information.
■ 메시지 타입: 메시지의 프로시져 유형을 식별하기 위한 정보를 포함한다.■ Message Type: Contains information to identify the procedure type of the message.
■ 제 1 기지국 단말 X2AP 식별자(ID): 마스터 기지국에 의해 할당되어 마스터 기지국 내에서 X2 인터페이스를 통한 단말을 유일하게 식별하는 식별자 정보를 포함한다.First Base Station Terminal X2AP Identifier (ID): Included by the master base station, identifier information uniquely identifying the terminal through the X2 interface in the master base station.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자(ID): 제 2 기지국이 제공하는 셀의 E-UTRAN Cell Global Identifier (ECGI) 또는 스몰 셀 PCI(Physical Cell ID) 정보를 포함한다.Cell (small cell) identifier (ID) associated with the second base station: Contains E-UTRAN Cell Global Identifier (ECGI) or small cell Physical Cell ID (PCI) information of the cell provided by the second base station.
■ 제 2 기지국 셀(스몰셀)인덱스: 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국이 제공하는 셀(스몰 셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국이 제공하는 셀(스몰셀)들 내에서 또는 단말에 제 2 기지국이 제공하는 셀로 구성된 SCells 내에서, 각각의 제 2 기지국이 제공하는 셀(스몰셀) 또는 SCell을 식별하기 위한 인덱스 정보를 포함한다.■ Second base station cell (small cell) index: Cell (small cell) provided in the SCells configured in the terminal or in cells (small cells) provided by the second base station configured in the terminal or provided by the second base station configured in the terminal SCell (small) In the cell) or SCells composed of cells provided by the second base station to the terminal, index information for identifying a cell (small cell) or SCell provided by each second base station is included.
■ 단말 컨텍스트 정보: 단말 컨텍스트 정보에는 아래와 같은 정보가 포함될 수 있다.Terminal context information: The terminal context information may include the following information.
1) UE Security capabilities: 단말 내에 암호화와 무결성 보호를 위해 지원되는 알고리즘에 대한 정보를 포함한다. 또는 단말 내에 암호화를 위해 지원되는 알고리즘에 대한 정보를 포함한다. 또는 단말 내에 사용자 플레인 데이터의 암호화를 위해 지원되는 알고리즘에 대한 정보를 포함한다. 또 다른 방법으로 UE Security capabilities 정보는 전술한 베어러 설정 요청 메시지에 포함시키지 않고 제 1 기지국에서만 관리할 수도 있다1) UE Security capabilities: Contains information about the algorithms supported for encryption and integrity protection in the terminal. Or information about an algorithm supported for encryption in the terminal. Or information about an algorithm supported for encryption of user plane data in the terminal. Alternatively, the UE Security capabilities information may be managed only at the first base station without being included in the bearer establishment request message described above.
2) AS Security Information 또는 AS Security Key: 제 2 기지국에서 사용자 플레인 데이터에 대한 암호화 키(KUPenc) 정보를 포함한다. 또는 암호화 키(KUPenc)를 유도하기 위한 기지국 키(KeNB) 정보를 포함한다. 전술한 정보는 제 1 기지국의 KUPenc 또는 KeNB와 동일한 값을 사용할 수도 있고 다른 값을 사용할 수도 있다.2) AS Security Information or AS Security Key: Includes encryption key (K UPenc ) information for user plane data at the second base station. Or base station key (K eNB ) information for deriving an encryption key K UPenc . The above information may use the same value as K UPenc or K eNB of the first base station or may use a different value.
3) 단말 총 최대 비트 전송율(UE Aggregate Maximum Bit Rate, UE-AMBR): 단말 당 모든 Non-GBR 베어러들에 적용하는 최대 비트 전송율 집합으로 상향 또는 하향 방향으로 정의되며 MME에 의해 제 1 기지국으로 제공된 값이다. 또는 예를 들어, 제 1 기지국에서 제 2 기지국을 통해 사용자 플레인 데이터를 포워딩하는 경우에 UE-AMBR 정보는 전술한 베어러 설정 요청 메시지에 포함시키지 않고 제 1 기지국에서만 관리할 수도 있다. 만약, 특정 단말에 구성된 모든 Non-GBR 베어러들을 제 2 기지국을 통해 구성하는 경우 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate, UE-AMBR)를 포함할 수 있다. 또는 만약 특정 단말에 구성된 적어도 하나 이상의 Non-GBR 베어러들을 제 2 기지국을 통해 구성하는 경우, 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate, UE-AMBR)을 포함할 수 있다. 또는 만약 특정 단말에 구성된 적어도 하나 이상의 Non-GBR 베어러들을 제 2 기지국을 통해 구성하는 경우, 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate, UE-AMBR) 및 제 2 기지국을 통한 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate, UE-AMBR)의 처리비율 정보를 포함할 수 있다.3) UE Aggregate Maximum Bit Rate (UE-AMBR): A maximum bit rate set applied to all Non-GBR bearers per UE, defined in an up or down direction and provided to a first base station by an MME. Value. Or, for example, in the case where the first base station forwards user plane data through the second base station, the UE-AMBR information may be managed only by the first base station without being included in the above-described bearer setup request message. If all of the non-GBR bearers configured in a specific terminal are configured through the second base station, the terminal may include a UE Aggregate Maximum Bit Rate (UE-AMBR). Alternatively, if at least one non-GBR bearer configured in a specific terminal is configured through a second base station, the terminal may include a UE Aggregate Maximum Bit Rate (UE-AMBR). Alternatively, if at least one non-GBR bearer configured in a specific terminal is configured through the second base station, the UE Aggregate Maximum Bit Rate (UE-AMBR) and the terminal total maximum bit rate through the second base station It may include processing rate information of (UE Aggregate Maximum Bit Rate, UE-AMBR).
4) 제 2 기지국을 통한 E-RABs(E-UTRAN Radio Access Bearers) 셋업 리스트(E-RABs To Be Setup List) 정보: E-RABs 셋업 아이템에 대한 정보를 포함한다. E-RABs 셋업 아이템은 E-RAB ID, E-RAB Level QoS 파라미터, GTP Tunnel Endpoint 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.4) E-RABs To Be Setup List (E-RABs) Setup List (E-RABs) through the second base station (E-RABs To Be Setup List) information: Contains information on the E-RABs setup item. The E-RABs setup item may include at least one or more of an E-RAB ID, an E-RAB Level QoS parameter, and GTP Tunnel Endpoint information.
전술한 E-RABs 셋업 아이템에 포함될 수 있는 정보를 상세히 살펴보면, E-RAB ID는 단말에 대한 무선 액세스 베어러를 식별하기 위한 정보를 포함할 수 있다. 또한, E-RAB Level QoS 파라미터는 E-RAB에 적용되는 QoS(Quality of Service) 정보로 QCI, Allocation and Retention Priority, GBR QoS 정보를 포함할 수 있다. 또한, GTP Tunnel Endpoint는 도 2와 같이 제 1 기지국과 제 2 기지국 간의 인터페이스를 통해 사용자 플레인 데이터 전송하는 경우, 제 1 기지국과 제 2 기지국 간 사용자 플레인 데이터 전송을 위한 베어러의 끝점(endpoint)으로 제 1 기지국의 IP주소인 Transport Layer Address, GTP TEID(Tunnel Endpoint ID)를 포함할 수 있다. 또는 다른 방법으로 도 3과 같이 S-GW와 제 2 기지국 간 인터페이스를 통해 사용자 플레인 데이터를 전송하는 경우에는 S-GW와 제 2 기지국 간의 끝점으로 S-GW의 IP주소인 Transport Layer Address, GTP TEID(Tunnel Endpoint ID)를 포함할 수 있다.Looking at the information that may be included in the above-described E-RABs setup item in detail, the E-RAB ID may include information for identifying a radio access bearer for the terminal. In addition, the E-RAB Level QoS parameter is Quality of Service (QoS) information applied to the E-RAB and may include QCI, Allocation and Retention Priority, and GBR QoS information. In addition, when the user plane data is transmitted through the interface between the first base station and the second base station as shown in FIG. 2, the GTP tunnel endpoint is an endpoint of a bearer for transmitting user plane data between the first base station and the second base station. 1 may include a transport layer address, a GTP TEID (Tunnel Endpoint ID), which is an IP address of a base station. Alternatively, when user plane data is transmitted through the interface between the S-GW and the second base station as shown in FIG. 3, the transport layer address and the GTP TEID, which are IP addresses of the S-GW, as endpoints between the S-GW and the second base station. (Tunnel Endpoint ID) may be included.
5) 단말 캐퍼빌리티(Capability) 정보: MME를 통해 수신된 단말 컨텍스트 정보에 포함된 단말 캐퍼빌리티 정보 중 제 2 기지국을 통한 사용자 데이터 전송을 위한 무선자원을 구성하는데 필요한 단말 캐퍼빌리티 정보를 포함한다. 일 예를 들어, 단일 송수신(single Tx/Rx) 또는 복수 송수신(multi Tx/Rx) 관련 정보를 포함할 수 있다5) UE Capability Information: Contains UE capability information necessary for configuring radio resources for user data transmission through a second base station among UE capability information included in UE context information received through the MME. For example, it may include information related to single transmission / reception (single Tx / Rx) or multiple transmission / reception (multi Tx / Rx).
위에서 살펴본 바와 같이 베어러 설정 요청 메시지는 위에서 일 예를 들어 설명한 각 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.As described above, the bearer establishment request message may include at least one or more pieces of information described above as an example.
본 발명의 일 실시예에 따른 제 1 기지국(401)은 제 2 기지국(402)으로부터 베어러 설정 응답 메시지를 수신할 수 있다(S425).The first base station 401 according to an embodiment of the present invention may receive a bearer setup response message from the second base station 402 (S425).
제 1 기지국(401)으로부터 사용자 플레인 데이터 전송을 위한 베어러 설정 요청 메시지를 수신한 제 2 기지국(402)은 베어러 설정 응답 메시지를 제 1 기지국(401)으로 전송한다(S425).Upon receiving the bearer setup request message for user plane data transmission from the first base station 401, the second base station 402 transmits a bearer setup response message to the first base station 401 (S425).
본 발명의 일 실시예에 따른 베어러 설정 응답 메시지는, 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보, 제 2 기지국 셀 시스템 정보, 제 2 기지국 셀 전용 MAC 계층 구성 정보, E-RABs(E-UTRAN Radio Access Bearers) 수락 리스트 정보 및 상기 수락된 E-RAB에 대한 제 2 기지국 데이터 무선베어러 구성정보 중 적어도 하나 이상의 정보를 포함할 수 있다.The bearer establishment response message according to an embodiment of the present invention may include cell identifier information associated with a second base station, second base station cell index information, second base station cell random access channel preamble information, second base station cell system information, and a second base station. It may include at least one or more of cell-specific MAC layer configuration information, E-UTRAN Radio Access Bearers (E-RABs) acceptance list information, and second base station data radio bearer configuration information for the accepted E-RAB.
또한, 본 발명의 일 실시예에 따른 베어러 설정 응답 메시지는 제 1 기지국 식별자 정보, 제 2 기지국 식별자 정보 및 전용 무선자원 구성정보 중 적어도 하나 이상의 정보를 더 포함할 수도 있다. 또한, 이하에서 구체적으로 예를 들어 설명하는 각 정보를 더 포함할 수도 있다.In addition, the bearer setup response message according to an embodiment of the present invention may further include at least one or more of first base station identifier information, second base station identifier information, and dedicated radio resource configuration information. In addition, it may further include each piece of information described below by way of example.
구체적으로 일 예를 들면, 베어러 설정 응답 메시지는 다음 중 하나 이상의 정보를 포함할 수 있다.Specifically, for example, the bearer establishment response message may include one or more of the following information.
■ 메시지 타입: 메시지의 프로시져 유형을 식별하기 위한 정보를 포함한다.■ Message Type: Contains information to identify the procedure type of the message.
■ 제 1 기지국 단말 X2AP 식별자(ID): 제 1 기지국에 의해 할당되는 식별자 정보를 포함한다.First base station terminal X2AP identifier (ID): Contains identifier information allocated by the first base station.
■ 제 2 기지국 단말 X2AP 식별자(ID): 제 2 기지국에 의해 할당되는 식별자 정보를 포함한다.Second base station terminal X2AP identifier (ID): Contains identifier information allocated by the second base station.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자(ID): 제 2 기지국에 연관된 스몰 셀의 E-UTRAN Cell Global Identifier (ECGI) 또는 스몰 셀 PCI(Physical Cell ID), ARFCN(Absolute Radio Frequency Channel) 또는 제 2 기지국에 연관된 셀임을 구별하기 위한 구분정보(예를 들어 1비트를 통해 제 2 기지국에 연관된 셀인지 여부를 구분하여 표시)를 포함한다.■ Cell (Small Cell) Identifier (ID) associated with the second base station: E-UTRAN Cell Global Identifier (ECGI) or Small Cell Physical Cell ID (PCI) of the small cell associated with the second base station, Absolute Radio Frequency Channel (ARFCN) Or identification information for distinguishing that the cell is associated with the second base station (for example, whether the cell is associated with the second base station through one bit and displayed separately).
■ 제 2 기지국 셀(스몰셀)인덱스: 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국에 연관된 세컨더리 셀(스몰셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국에 연관된 세컨더리 셀(스몰셀)들 내에서 또는 단말에 제 2 기지국에 연관된 세컨더리 셀로 구성된 SCells 내에서, 각각의 제 2 기지국에 연관된 세컨더리 셀(스몰셀) 또는 SCell을 식별하기 위한 인덱스 정보를 포함한다.■ Second Base Station Cell (Small Cell) Index: Secondary Cell (Small Cell) Small in SCells Configured in Terminal or Secondary Cells (Small Cells) Associated in Second Base Station Configured in Terminal or Associated with Second Base Station Configured in SCell in Terminal Cell information) or index information for identifying a secondary cell (small cell) or a SCell associated with each second base station, in SCells configured with a secondary cell associated with a second base station.
■ E-RABs(E-UTRAN Radio Access Bearers) 수락 리스트(E-RABs Admitted List) 정보: E-RABs 수락 아이템 정보를 포함할 수 있다. E-RABs 수락 아이템 정보는 E-RAB ID, GTP Tunnel Endpoint, DRB 식별자(DRB ID), PDCP 구성정보(PDCP-Config), RLC 구성정보(RLC-Config), 논리채널식별자(logicalChannelIdentity), 논리채널구성정보(logicalChannelConfig) 및 물리채널구성정보(PhysicalConfigDedicated) 중 적어도 하나 이상의 정보를 포함할 수 있다.■ E-RABs Admitted List (E-RABs) Admitted List (E-RABs) Admitted List (E-RABs) Admitted List information: E-RABs may include E-RABs Accepted Item information. E-RABs acceptance item information includes E-RAB ID, GTP Tunnel Endpoint, DRB Identifier (DRB ID), PDCP Configuration Information (PDCP-Config), RLC Configuration Information (RLC-Config), Logical Channel Identity, Logical Channel It may include at least one of configuration information (logicalChannelConfig) and physical channel configuration information (PhysicalConfigDedicated).
구체적으로 E-RAB ID는 단말에 대한 무선 액세스 베어러를 식별하기 위한 정보를 포함한다. 또한, GTP Tunnel Endpoint는 도 2와 같이 제 1 기지국과 제 2 기지국 간 인터페이스를 통해 사용자 플레인 데이터 전송하는 경우, 제 1 기지국과 제 2 기지국 간의 베어러 끝점(endpoint)이다. 또는 다른 방법으로 GTP Tunnel Endpoint는 도 3과 같이 S-GW와 제 2 기지국 간 인터페이스를 통해 사용자 플레인 데이터를 전송하는 경우에는 S-GW와 제 2 기지국 간의 끝점으로 제 2 기지국의 IP주소인 Transport Layer Address, GTP TEID(Tunnel Endpoint ID)를 포함한다. Specifically, the E-RAB ID includes information for identifying a radio access bearer for the terminal. In addition, the GTP tunnel endpoint is a bearer endpoint between the first base station and the second base station when transmitting user plane data through an interface between the first base station and the second base station as shown in FIG. 2. Alternatively, when the GTP tunnel endpoint transmits user plane data through the interface between the S-GW and the second base station as shown in FIG. 3, the GTP tunnel terminal is an endpoint between the S-GW and the second base station. Address, GTP TEID (Tunnel Endpoint ID) is included.
또한, E-RABs 수락 아이템 정보에는 수락된 E-RAB에 대한 제 2 기지국 데이터 무선베어러 구성정보가 포함될 수 있다.In addition, the E-RABs acceptance item information may include second base station data radio bearer configuration information for the accepted E-RAB.
구체적으로, PDCP 구성정보(PDCP-Config)는 도 3과 같이 S-GW와 제 2 기지국 간 인터페이스를 통해 사용자 플레인 데이터를 전송하는 경우, 단말 내 제 2 기지국을 통해 전송하는 무선 베어러를 위한 PDCP 계층 구성정보를 포함한다. RLC 구성정보(RLC-Config)는 단말 내 제 2 기지국을 통해 전송하는 무선 베어러를 위한 RLC 계층 구성정보를 포함한다. 논리채널식별자(logicalChannelIdentity)와 논리채널구성정보(logicalChannelConfig)는 단말 내 제 2 기지국을 통해 전송하는 무선 베어러를 위한 논리채널식별자(logicalChannelIdentity), 논리채널구성정보(logicalChannelConfig)를 나타낸다. 물리채널구성정보(PhysicalConfigDedicated)는 제 2 기지국을 통해 전송하는 무선 베어러를 위한 단말 내 물리 계층 구성정보를 나타낸다Specifically, PDCP configuration information (PDCP-Config) is a PDCP layer for a radio bearer to transmit through the second base station in the terminal, when transmitting the user plane data through the interface between the S-GW and the second base station as shown in FIG. Contains configuration information. The RLC configuration information (RLC-Config) includes RLC layer configuration information for a radio bearer transmitted through a second base station in the terminal. The logical channel identifier (logicalChannelIdentity) and logical channel configuration information (logicalChannelConfig) represents a logical channel identifier (logicalChannelIdentity), logical channel configuration information (logicalChannelConfig) for the radio bearer transmitted through the second base station in the terminal. Physical channel configuration information (PhysicalConfigDedicated) represents the physical layer configuration information in the terminal for the radio bearer transmitted through the second base station
■ E-RABs 미수락 리스트: 제 2 기지국의 부하나 상태 등에 따라 제 2 기지국을 통해 요청된 무선 베어러 중 처리할 수 없는 무선 베어러 리스트 정보를 포함한다. ■ E-RABs non-acceptance list: includes radio bearer list information that cannot be processed among radio bearers requested through the second base station according to the load or state of the second base station.
예를 들어, 트래픽 부하가 높은 경우와 같이 모든 요청 베어러를 처리하지 못하는 경우, 제 2 기지국은 모든 요청 베어러 리스트를 미수락 리스트에 포함하거나 또는 메시지 타입을 달리하는 메시지(예를 들어, 거절 메시지)를 전달할 수 있다For example, if it fails to process all request bearers, such as when the traffic load is high, the second base station may include all request bearer lists in the unaccepted list or change the message type (eg, reject message). Can pass
■ 제 2 기지국 셀 랜덤 액세스 채널 프리앰블: 제 2 기지국에 연관된 셀을 통해 경쟁 없는(Contention Free) 랜덤 액세스 프로시져를 수행하기 위한 프리앰블 정보(예를 들어, RACH-ConfigDedicated 정보에 포함되는 ra-PreambleIndex)를 포함한다.■ Second base station cell random access channel preamble: preamble information (eg, ra-PreambleIndex included in RACH-ConfigDedicated information) for performing a contention free random access procedure through a cell associated with the second base station. Include.
■ 제 2 기지국 셀(스몰셀) 시스템 정보: 제 2 기지국에 의해서 구성되는 세컨더리 셀 또는 스몰셀에 대한 시스템 정보이다. 제 2 기지국을 통해 사용자 플레인 데이터를 전송하기 위해서 필요한 공통 무선자원구성정보(RadioResourceConfigCommon 정보를 포함한다. 예를 들어, PDSCH-config, PHICH-Config, PUSCH-Config, TDD-Config 등을 포함한다. Second base station cell (small cell) system information: System information for the secondary cell or small cell configured by the second base station. Common radio resource configuration information (RadioResourceConfigCommon information) necessary for transmitting user plane data through the second base station is included, for example, PDSCH-config, PHICH-Config, PUSCH-Config, TDD-Config, and the like.
위에서 예를 들어 설명한 바와 같이 베어러 설정 응답 메시지는 위의 각 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.As described above by way of example, the bearer establishment response message may include at least one or more of each of the above information.
본 발명의 일 실시예에 따른 제 1 기지국(401)은 단말(403)로 제 2 기지국에 연관된 셀에 대한 제 2 기지국에 연관된 셀(스몰셀) 식별자 정보, 제 2 기지국 셀(스몰셀) 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 전송하는 단계를 포함할 수 있다(S430).According to an embodiment of the present invention, the first base station 401 is a terminal 403, which is a cell (small cell) identifier information associated with a second base station for a cell associated with a second base station, and a second base station cell (small cell) index. The method may include transmitting higher layer signaling including at least one of information and data radio bearer information configured through the second base station (S430).
예를 들어 설명하면, 제 1 기지국(401)은 제 2 기지국(402)과 사용자 플레인 데이터 전송을 위한 베어러 설정 시그널링 절차를 완료한 후(예를 들어, 베어러 설정 응답 메시지를 수신한 후, S425단계 후) 상위계층 시그널링 (예를 들어, RRC 연결 재구성 메시지(RRC Connection Reconfiguration 메시지))에 추가/수정할 제 2 기지국이 제공하는 셀(스몰 셀) 정보를 포함하여 전송할 수 있다(S430).For example, after the first base station 401 completes the bearer setup signaling procedure for transmitting user plane data with the second base station 402 (for example, after receiving a bearer setup response message, step S425). Later) it may include cell (small cell) information provided by the second base station to be added / modified to higher layer signaling (eg, an RRC connection reconfiguration message) (S430).
또는, 제 1 기지국(401)은 베어러 설정 시그널링 절차를 개시한 후(예를 들어, 베어러 설정 요청 메시지를 송신한 후, S420단계 후) 단말(403)로 상위계층 시그널링을 전송할 수도 있다. 단말(403)은 제 1 기지국(401)으로부터 상위계층 시그널링을 수신하여 사용자 플레인 데이터 전송을 위한 제 2 기지국에 연관된 셀(스몰 셀)을 추가/수정할 수 있다. 또는 제 2 기지국에 연관된 셀(스몰 셀)을 세컨더리 셀로 추가/수정할 수 있다 또한, 본 발명의 다른 실시예에 따른 제 2 기지국에 연관된 셀 식별자 정보 및 제 2 기지국 셀 인덱스 정보 중 적어도 하나 이상의 정보는 추가수정할 DRB(DRB-ToAddMod) 정보에 포함되어 전송될 수도 있다.Alternatively, the first base station 401 may transmit higher layer signaling to the terminal 403 after initiating a bearer establishment signaling procedure (for example, after transmitting a bearer establishment request message, and after step S420). The terminal 403 may receive higher layer signaling from the first base station 401 and add / modify a cell (small cell) associated with the second base station for user plane data transmission. Alternatively, the cell (small cell) associated with the second base station may be added / modified as a secondary cell. Further, at least one of cell identifier information and second base station cell index information associated with the second base station according to another embodiment of the present invention may be used. It may be included in the DRB (DRB-ToAddMod) information to be additionally modified.
또한, 본 발명의 또 다른 실시예에 따른 제 2 기지국(402)을 통해 구성되는 데이터 무선베어러 정보는, 단말(403)이 MAC 계층에서 제 1 기지국(401)과 제 2 기지국(402)을 구별하기 위한 정보 및 제 1 기지국(401)이 제공하는 셀과 제 2 기지국(402)이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.In addition, the data radio bearer information configured through the second base station 402 according to another embodiment of the present invention, the terminal 403 distinguishes the first base station 401 and the second base station 402 in the MAC layer. At least one of the following information and information for distinguishing the cell provided by the first base station 401 and the cell provided by the second base station 402 may be included.
전술한 상위계층 시그널링에 추가/수정할 제 2 기지국에 연관된 셀(스몰 셀) 정보가 포함되는 경우에, 제 2 기지국 셀을 식별하기 위한 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보의 무선자원구성정보를 예를 들어 설명하면 아래와 같다.If the above-described higher layer signaling includes cell (small cell) information associated with the second base station to be added / modified, cell identifier information, second base station cell index information, and the like associated with the second base station for identifying the second base station cell; For example, radio resource configuration information of data radio bearer information configured through the second base station will be described below.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자: 제 2 기지국에 연관된 셀(스몰 셀)의 PCI(Physical Cell ID), ARFCN(Absolute Radio Frequency Channel) 및 제 2 기지국 셀임을 구별하기 위한 구분정보 중 적어도 하나 이상의 정보를 포함한다. 예를 들어, 제 2 기지국 셀임을 구별하기 위한 구분 정보는 1비트를 통해 제 2 기지국에 연관된 셀인지 여부를 구분하여 표시하는 표시 정보일 수 있다.■ Cell (small cell) identifier associated with the second base station: Among the distinguishing information for distinguishing the Physical Cell ID (PCI), the Absolute Radio Frequency Channel (ARFCN), and the second base station cell of the cell (small cell) associated with the second base station It includes at least one or more information. For example, the classification information for identifying the second base station cell may be display information for distinguishing and displaying whether the cell is associated with the second base station through 1 bit.
■ 제 2 기지국 셀(스몰 셀) 인덱스(또는 SCell 인덱스): 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국셀(스몰 셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 제 2 기지국 셀(스몰 셀)로 구성된 SCells 내에서, 각각의 제 2 기지국 세컨더리 셀(스몰 셀) 또는 SCell을 식별하기 위해 사용되는 인덱스 정보를 포함한다.■ Second base station cell (small cell) index (or SCell index): Second base station cell (small cell) configured in SCells configured in UE or in second base station cells (small cells) configured in UE or configured in SCell ) Or index information used to identify each second base station secondary cell (small cell) or SCell in SCells configured as a second base station cell (small cell) in the terminal.
전술한 제 2 기지국 셀 인덱스 정보는 제 1 기지국이 결정 또는 할당하여 베어러 설정 요청 메시지에 포함하여 보낼 수 있다. 단, 베어러 설정 응답 메시지에는 포함되지 않을 수 있다.The above-described second base station cell index information may be determined or allocated by the first base station and included in the bearer setup request message. However, it may not be included in the bearer setup response message.
또는 전술한 제 2 기지국 셀 인덱스 정보는 제 1 기지국이 결정 또는 할당하여 베어러 설정 요청 메시지에 포함하여 보낼 수 있고, 제 2 기지국이 이를 확인하여 베어러 설정 응답 메시지에도 포함될 수도 있다. Alternatively, the above-described second base station cell index information may be determined or allocated by the first base station and included in the bearer setup request message, and may be included in the bearer setup response message by the second base station.
또 다른 방법으로 제 2 기지국 셀 인덱스(또는 SCell인덱스) 정보는 제 2 기지국이 결정 또는 할당하여 베어러 설정 응답 메시지에 포함하여 보낼 수 있다. 이 때 제1기지국의 베어러 설정 요청 메시지에는 포함되지 않을 수 있다.Alternatively, the second base station cell index (or SCell index) information may be determined or allocated by the second base station and included in the bearer setup response message. At this time, it may not be included in the bearer setup request message of the first base station.
또 다른 방법으로 제 2 기지국 셀 인덱스(또는 SCell인덱스) 정보는 제 2 기지국 셀을 제 1 기지국의 SCell과 구분할 수 있도록 기존 SCell 인덱스로 사용하는 값(예를 들어, 1~7)이 아닌 다른 값(예를 들어, 8)을 사용할 수 있다. 이러한 경우 베어러 설정 요청 메시지 및 베어러 설정 응답 메시지에 모두 포함되지 않을 수도 있다. 또는 베어러 설정 요청 메시지 및/또는 베어러 설정 응답 메시지에 포함할 수도 있다. 즉, 기존 SCell 인덱스로 사용하는 값이 아닌 다른 값을 사용하도록 하기 위해 현재 1에서 7까지의 정수 값을 가질 수 있는 SCell 인덱스를 1~14까지의 정수 값을 가질 수 있도록 하고, 1에서 7까지의 정수값은 마스터 기지국(제 1 기지국)의 SCell들을 위한 인덱스로 8~14는 세컨더리 기지국(제 2 기지국) 셀을 위한 인덱스로 사용할 수 있다. Alternatively, the second base station cell index (or SCell index) information may be different from a value used as an existing SCell index (for example, 1 to 7) to distinguish the second base station cell from the SCell of the first base station. (Eg, 8) can be used. In this case, it may not be included in both the bearer establishment request message and the bearer establishment response message. Or it may be included in the bearer setup request message and / or bearer setup response message. That is, in order to use a value other than the value used as the existing SCell index, SCell index that can currently have an integer value from 1 to 7 can be an integer value from 1 to 14, and 1 to 7 The integer value of may be used as an index for SCells of a master base station (first base station) and 8 to 14 as an index for a secondary base station (second base station) cell.
또 다른 방법으로 제 2 기지국 셀을 제 1 기지국의 SCell과 구분할 수 있도록 SCell 인덱스 및 제 2 기지국 식별자(또는 제 2 기지국 셀 식별자) 필드를 함께 전송하도록 할 수 있다. 또 다른 방법으로 제 2 기지국 셀을 제 1 기지국 SCell과 구분할 수 있도록 SCell인덱스 내의 1비트를 제 2 기지국(또는 제 2 기지국 셀)임을 구분하기 위한 필드로 포함하여 SCell인덱스를 구성할 수 있다.Alternatively, the SCell index and the second base station identifier (or second base station cell identifier) field may be transmitted together to distinguish the second base station cell from the SCell of the first base station. Alternatively, the SCell index may be configured by including one bit in the SCell index as a field for identifying the second base station cell (or second base station cell) so as to distinguish the second base station cell from the first base station SCell.
■ 스몰셀공통무선자원구성정보: 단말이 제 2 기지국에 연관된 셀(스몰 셀)에서 동작하기 위해 필수적인(essential)정보로 시스템 구성정보에 해당되는 물리계층 구성 파라미터 또는 물리계층 구성 파라미터와 MAC계층 구성 파라미터를 포함할 수 있다.■ Small cell common radio resource configuration information: essential information for the UE to operate in a cell (small cell) associated with the second base station (physical layer configuration parameters or physical layer configuration parameters and MAC layer configuration corresponding to the system configuration information) It may include a parameter.
■ 스몰셀전용무선자원구성정보: 제 2 기지국에 연관된 셀(스몰 셀)에서 동작을 위한 단말 특이적(UE-specific) 구성 정보(e.g. physical channel configuration, mac-MainConfig)를 포함할 수 있다.■ Small cell dedicated radio resource configuration information: UE-specific configuration information (e.g. physical channel configuration, mac-MainConfig) for operation in the cell (small cell) associated with the second base station may be included.
예를 들어 스몰셀전용무선자원구성정보는 전술한 제 2 기지국을 통해 전송하는 무선 베어러를 위한 단말 내 RLC 계층 구성정보, 제 2 기지국을 통해 전송하는 무선 베어러를 위한 논리채널식별자(logicalChannelIdentity), 논리채널구성정보(logicalChannelConfig), 제 2 기지국에 연관된 셀과 경쟁 없는(contention free) 랜덤 액세스 프로시져를 수행하기 위한 프리앰블 정보, 제 2 기지국을 통해 전송하는 무선 베어러를 위한 물리 계층 구성정보 중 하나 이상의 정보를 포함할 수 있다For example, the small cell dedicated radio resource configuration information includes RLC layer configuration information in a terminal for a radio bearer transmitted through the aforementioned second base station, logical channel identifier (logicalChannelIdentity) and logic for a radio bearer transmitted through the second base station. One or more of channel configuration information (logicalChannelConfig), preamble information for performing a contention free random access procedure with a cell associated with a second base station, and physical layer configuration information for a radio bearer transmitted through the second base station. Can contain
단말(403)은 위와 같은 정보를 포함하는 상위계층 시그널링을 수신하여 제 2 기지국에 연관된 셀을 추가/수정할 수 있다(S435). 단말(403)은 제 2 기지국에 연관된 셀을 추가/수정하여 사용자 플레인 데이터를 제 2 기지국(402)으로 전송할 수 있다(S440).The terminal 403 may add / modify a cell associated with the second base station by receiving higher layer signaling including the above information (S435). The terminal 403 may add / modify a cell associated with the second base station and transmit user plane data to the second base station 402 (S440).
제 1 기지국(401)은 전술한 바와 같이 상위계층 시그널링에 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보를 포함하여 단말의 DRB 추가/수정/변경을 제어할 수 있다.As described above, the first base station 401 may control the DRB addition / modification / change of the terminal by including data radio bearer information configured through the second base station in higher layer signaling.
구체적으로 제 1 기지국(401)은 제 2 기지국(402)과 사용자 플레인 데이터 전송을 위한 베어러 설정 시그널링 절차를 완료한 후(예를 들어, 베어러 설정 응답 메시지를 수신한 후, S425) RRC 연결 재구성(Connection Reconfiguration) 메시지에 추가/수정할 DRBs 정보를 포함하여 전송할 수 있다(S430).In more detail, after the first base station 401 completes the bearer establishment signaling procedure for transmitting user plane data with the second base station 402 (for example, after receiving a bearer establishment response message, S425), the RRC connection reconfiguration ( Connection Reconfiguration) message may be transmitted including the DRBs information to be added / modified (S430).
단말(403)은 상위계층 시그널링을 수신하여 사용자 플레인 데이터 전송을 위해 제 2 기지국(402)과 DRBs를 추가/수정하거나 제 1 기지국(401)의 DRBs를 제 2 기지국(402)의 DRBs로 수정할 수 있다. 또는 단말(403)은 제 1 기지국(401)의 DRBs를 제 1 기지국(401)과 제 2 기지국(402)을 통한 DRBs로 수정할 수도 있다.The terminal 403 may receive higher layer signaling to add / modify the second base station 402 and the DRBs for user plane data transmission or to modify the DRBs of the first base station 401 to the DRBs of the second base station 402. have. Alternatively, the terminal 403 may modify the DRBs of the first base station 401 into DRBs through the first base station 401 and the second base station 402.
본 발명의 일 실시예에 따른 데이터 제 2 기지국을 통해 구성되는 무선 베어러 정보는, 데이터 무선 베어러 식별정보, PDCP(Packet Data Convergence Protocol) 및 RLC(Radio Link Control) 구성정보, 논리채널 식별자, 논리채널 구성정보 및 제 1 기지국에 연관된 셀 식별자 정보 중 적어도 하나 이상의 정보를 포함할 수 있다. The radio bearer information configured through the data second base station according to an embodiment of the present invention includes data radio bearer identification information, Packet Data Convergence Protocol (PDCP) and Radio Link Control (RLC) configuration information, logical channel identifier, and logical channel. At least one of configuration information and cell identifier information associated with the first base station may be included.
또한, 제 2 기지국(402)을 통해 구성되는 데이터 무선베어러 정보는, 단말(403)이 MAC 계층에서 제 1 기지국(401)과 제 2 기지국(402)을 구별하기 위한 정보 및 제 1 기지국(401)이 제공하는 셀과 제 2 기지국(402)이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.In addition, the data radio bearer information configured through the second base station 402 includes information for the terminal 403 to distinguish the first base station 401 and the second base station 402 in the MAC layer and the first base station 401. ) May include at least one or more of information for distinguishing a cell provided by the cell) and a cell provided by the second base station 402.
예를 들어, 추가/수정할 DRBs 정보를 포함하는 데이터 무선 베어러 정보는 다음 중 적어도 하나 이상의 정보를 포함할 수 있다.For example, the data radio bearer information including the DRBs information to be added / modified may include at least one of the following information.
■ EPS-Beareridentity: EPS 베어러 식별자로 E-RAB ID 정보를 포함할 수 있다.■ EPS-Beareridentity: EPS bearer identifier may include E-RAB ID information.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자: 제 2 기지국에 연관된 셀의 PCI(Physical Cell ID), ARFCN(Absolute Radio Frequency Channel) 및 제 2 기지국 셀임을 구별하기 위한 구분정보 중 적어도 하나 이상의 정보를 포함할 수 있다. 예를 들어, 제 2 기지국 셀임을 구별하기 위한 구분 정보는 1비트를 통해 제 2 기지국에 연관된 셀인지 여부를 구분하여 표시하는 정보 일 수 있다.■ A cell (small cell) identifier associated with the second base station: at least one or more pieces of information for identifying a physical cell ID (PCI), an absolute radio frequency channel (ARFCN) and a second base station cell of the cell associated with the second base station. It may include. For example, the classification information for identifying the second base station cell may be information for distinguishing and displaying whether the cell is associated with the second base station through 1 bit.
■ 제 2 기지국 셀(스몰 셀) 인덱스: 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰셀)들 내에서 또는 단말에 제 2 기지국 셀(스몰 셀)로 구성된 SCell 내에서, 각각의 제 2 기지국 셀(스몰 셀) 또는 SCell을 식별하기 위해 사용되는 인덱스 정보를 포함할 수 있다.■ Second base station cell (small cell) index: within the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured with the SCell in the terminal or Within the SCell configured as the second base station cell (small cell) in the terminal, it may include index information used to identify each second base station cell (small cell) or SCell.
■ DRB-ID: 제 2 기지국으로부터 수신한 DRB-ID 정보를 포함한다.DRB-ID: Contains DRB-ID information received from the second base station.
■ PDCP-Config: 제 2 기지국으로부터 수신한 PDCP-Config 정보를 포함한다.PDCP-Config: Contains PDCP-Config information received from the second base station.
■ RLC-Config: 제 2 기지국으로부터 수신한 RLC-Config 정보를 포함한다.■ RLC-Config: Contains RLC-Config information received from the second base station.
■ logicalChannelIdentity: 논리채널 식별자에 대한 정보를 포함한다.■ logicalChannelIdentity: Contains information about logical channel identifier.
■ logicalChannelConfig: 제 2 기지국으로부터 수신한 논리채널구성정보에 대한 정보를 포함한다.■ logicalChannelConfig: Contains information about logical channel configuration information received from the second base station.
본 발명의 다른 실시예에 따른 제 1 기지국(401)은 위에서 설명한 데이터 무선 베어러 정보를 포함하는 상위계층 시그널링을 베어러 설정 시그널링 절차 개시 후(예를 들어, 제 2 기지국으로 베어러 설정 요청 메시지를 송신한 후) 전송할 수도 있다.According to another embodiment of the present invention, the first base station 401 transmits a higher layer signaling including data radio bearer information described above after initiating a bearer establishment signaling procedure (for example, transmitting a bearer establishment request message to a second base station). After).
단말(403)은 제 1 기지국(401)으로부터 상위계층 시그널링을 수신하여 사용자 플레인 데이터 전송을 위해 제 2 기지국(402)과 DRBs를 추가/수정하거나 제 1 기지국(401)의 DRBs를 제 2 기지국(402)의 DRBs로 수정할 수도 있다(S435).The terminal 403 receives upper layer signaling from the first base station 401 and adds / modifies DRBs and DRBs of the second base station 402 and transmits DRBs of the first base station 401 for the user plane data transmission. It may be modified to the DRBs of 402 (S435).
또는 단말(403)은 제 1 기지국(401)의 DRBs를 제 1 기지국(401)과 제 2 기지국(402)를 통한 DRBs로 수정할 수도 있다(S435).Alternatively, the terminal 403 may modify the DRBs of the first base station 401 into DRBs through the first base station 401 and the second base station 402 (S435).
예를 들어, 베어러 설정 요청 메시지 전송 후 전송되는 데이터 무선 베어러 정보는 다음 중 적어도 하나 이상의 정보를 포함할 수 있다.For example, the data radio bearer information transmitted after the bearer establishment request message transmission may include at least one of the following information.
■ EPS-Beareridentity: EPS 베어러 식별자로 E-RAB ID 정보를 포함할 수 있다.■ EPS-Beareridentity: EPS bearer identifier may include E-RAB ID information.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자: 제 2 기지국에 연관된 셀의 PCI(Physical Cell ID), ARFCN(Absolute Radio Frequency Channel) 정보를 포함할 수 있다.■ Cell (small cell) identifier associated with the second base station: It may include Physical Cell ID (PCI), Absolute Radio Frequency Channel (ARFCN) information of the cell associated with the second base station.
■ 제 2 기지국 셀(스몰 셀) 인덱스: 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 제 2 기지국 셀(스몰 셀)로 구성된 SCell 내에서, 각각의 제 2 기지국 셀(스몰 셀) 또는 SCell을 식별하기 위해 사용되는 인덱스 정보를 포함할 수 있다.■ Second base station cell (small cell) index: within the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured with the SCell in the terminal or Within the SCell configured as the second base station cell (small cell) in the terminal, it may include index information used to identify each second base station cell (small cell) or SCell.
■ DRB-ID: 제 1 기지국이 결정하여 제 2 기지국으로 전달한 DRB-ID 정보를 포함할 수 있다.DRB-ID: The information may include DRB-ID information determined by the first base station and delivered to the second base station.
■ PDCP-Config: 제 1 기지국이 결정하여 제 2 기지국으로 전달한 PDCP-Config 정보를 포함할 수 있다.PDCP-Config: may include PDCP-Config information determined by the first base station and delivered to the second base station.
■ RLC-Config: 제 1 기지국이 결정하여 제 2 기지국으로 전달한 RLC-Config 정보를 포함할 수 있다.■ RLC-Config: may include RLC-Config information determined by the first base station and delivered to the second base station.
■ logicalChannelIdentity: 논리채널 식별자 정보를 포함할 수 있다.■ logicalChannelIdentity: Can include logical channel identifier information.
■ logicalChannelConfig: 논리채널구성정보 정보를 포함할 수 있다.■ logicalChannelConfig: It can contain logical channel configuration information.
위에서 설명한 바와 같이 제 1 기지국(401)은 베어러 설정 응답 메시지를 수신한 후 또는 베어러 설정 요청 메시지를 전송한 후 각각 위와 같은 정보를 포함하는 상위계층 시그널링을 단말(403)로 전송할 수 있다.As described above, the first base station 401 may transmit higher layer signaling including the above information to the terminal 403 after receiving the bearer establishment response message or after transmitting the bearer establishment request message.
또한, 위와 같이 단말(403)로 전송되는 상위계층 시그널링에는 추가/수정할 DRB 정보 또는 해제할 DRB 정보와 함께 제 2 기지국 셀(스몰 셀)과 제 1 기지국 셀(매크로 셀)을 구별하기 위한 식별정보가 더 포함되어, 전술한 추가/수정할 DRB가 스몰셀(또는 제 2 기지국)을 통해 구성됨을 나타낼 수도 있다.In addition, in the upper layer signaling transmitted to the terminal 403 as described above, identification information for distinguishing the second base station cell (small cell) and the first base station cell (macro cell) together with DRB information to be added / modified or DRB information to be released. May be further included to indicate that the aforementioned DRB to be added / modified is configured through the small cell (or the second base station).
예를 들어, 이전에 제 1 기지국(401)을 통해 구성된 DRBs를 제 2 기지국(402)을 통해 추가/수정하는 경우에 추가/수정할 DRB에 대한 정보가 스몰 셀 식별자(또는 제 2 기지국 식별자 정보)를 포함할 수 있다. For example, when DRBs previously configured through the first base station 401 are added / modified through the second base station 402, the information on the DRB to be added / modified may be a small cell identifier (or second base station identifier information). It may include.
또한, 해제할 DRB에 대한 정보(DRB-ToAddMod)에는 매크로 셀에서 해제할 DRB 정보와 매크로 셀 식별자 정보(또는 제 1 기지국 식별자 정보)가 함께 포함될 수도 있다.In addition, the information about the DRB to be released (DRB-ToAddMod) may include the DRB information to be released in the macro cell and macro cell identifier information (or first base station identifier information) together.
또 다른 방법으로는 만약 전술한 제 2 기지국 셀(스몰 셀) 인덱스 또는 SCell 인덱스가 제 2 기지국 셀(또는 제 2 기지국)을 구분할 수 있다면, 전술한 추가/수정할 DRB에 전술한 제 2 기지국 셀(스몰 셀) 인덱스 또는 SCell 인덱스가 포함될 수도 있다.Alternatively, if the above-described second base station cell (small cell) index or SCell index can distinguish the second base station cell (or second base station), the above-described second base station cell ( Small cell) index or SCell index may be included.
이하에서는 본 발명의 일 실시예에 따른 제 1 기지국(401)이 상위계층 시그널링에 데이터 무선 베어러 정보를 포함하는 경우, 포함되는 정보의 각 파라미터들을 결정하는 주체에 대해서 자세히 설명한다.Hereinafter, when the first base station 401 according to an embodiment of the present invention includes data radio bearer information in higher layer signaling, a subject for determining each parameter of the included information will be described in detail.
본 발명의 일 실시예에 따른 상위계층 시그널링은, 제 2 기지국에 연관된 셀 구성을 위한 정보를 더 포함하되, 제 2 기지국에 연관된 셀 구성을 위한 정보는 제 2 기지국이 설정하여 제 1 기지국으로 전송한 정보일 수 있다.The higher layer signaling according to an embodiment of the present invention further includes information for cell configuration associated with the second base station, and information for cell configuration associated with the second base station is set by the second base station and transmitted to the first base station. It may be one piece of information.
즉, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보는, 제 2 기지국이 설정하여 제 1 기지국으로 전송한 정보일 수 있다.That is, the second base station cell index information and the data radio bearer information configured through the second base station may be information set by the second base station and transmitted to the first base station.
또는, 제 2 기지국에 연관된 셀 구성을 위한 정보는 측정 리포팅 정보, 제 1 기지국 데이터 부하 정보 및 베어러 설정 응답 메시지 중 적어도 하나 이상의 정보에 기초하여 제 1 기지국에 의해서 설정될 수도 있다.Alternatively, the information for cell configuration associated with the second base station may be set by the first base station based on at least one or more of measurement reporting information, first base station data load information, and bearer setup response message.
구체적으로 각 경우에 대한 예를 들어 설명한다.Specifically, an example of each case will be described.
1) 제 2 기지국이 결정하는 방법.1) Method determined by the second base station.
제 1 기지국(401)은 MME로부터 수신된 이니셜 컨텍스트 셋업 요청(Initial Context Setup Request) 메시지 내의 정보(예를 들어, E-RABs list), 측정 리포팅 정보 및 제 1 기지국의 데이터 부하 정보 중 적어도 하나 이상의 정보를 베어러 설정 요청 메시지에 포함하여 제 2 기지국(402)으로 전달할 수 있다. The first base station 401 may include at least one of information (eg, E-RABs list), measurement reporting information, and data load information of the first base station in an initial context setup request message received from the MME. The information may be included in the bearer establishment request message and transmitted to the second base station 402.
제 2 기지국(402)는 전달된 상기 정보에 기초하여 전술한 상위계층 시그널링에 포함되는 파라미터를 결정할 수 있다.The second base station 402 may determine the parameters included in the above-described higher layer signaling based on the transmitted information.
즉, 제 2 기지국(402)는 전달된 상기 정보에 기초하여 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 또는 각 정보에 포함되는 파라미터를 결정할 수 있다.That is, the second base station 402 may determine the second base station cell index information and the data radio bearer information configured through the second base station or a parameter included in each information based on the transmitted information.
결정된 파라미터 정보들은 제 1 기지국으로 전송되어 상위계층 시그널링(예를 들어, RRC Connection Reconfiguration 메시지)을 통해 단말로 전송될 수 있다.The determined parameter information may be transmitted to the first base station and transmitted to the terminal through higher layer signaling (eg, an RRC Connection Reconfiguration message).
2) 제 1 기지국이 결정하는 방법.2) Method determined by the first base station.
제 1 기지국(401)은 MME로부터 수신된 이니셜 컨텍스트 셋업 요청(Initial Context Setup Request) 메시지 내의 정보(예를 들어, E-RABs list), 측정 리포팅 정보 및 제 1 기지국의 데이터 부하 정보 중 적어도 하나 이상의 정보에 기초하여 결정할 수 있다. 즉, 상위계층 시그널링(예를 들어, RRC Connection Reconfiguration 메시지)에 포함되는 전술한 파라미터들(예를 들어, PDCP 구성정보, RLC 구성정보, MAC 구성정보 등)은 제 1 기지국(401)에 의해 결정될 수 있다.The first base station 401 may include at least one of information (eg, E-RABs list), measurement reporting information, and data load information of the first base station in an initial context setup request message received from the MME. Decisions can be made based on information. That is, the above-described parameters (eg, PDCP configuration information, RLC configuration information, MAC configuration information, etc.) included in higher layer signaling (eg, RRC Connection Reconfiguration message) may be determined by the first base station 401. Can be.
3) 제 1 기지국이 결정하는 또 다른 방법.3) Another method determined by the first base station.
제 1 기지국(401)은 MME로부터 수신된 이니셜 컨텍스트 셋업 요청(Initial Context Setup Request) 메시지 내의 정보(예를 들어, E-RABs list), 측정 리포팅 정보, 제 1 기지국의 데이터 부하 정보 및 제 2 기지국(402)으로부터 수신된 베어러 설정 응답 메시지에 기초하여 결정할 수도 있다.The first base station 401 may include information (eg, E-RABs list), measurement reporting information, data load information of the first base station, and a second base station in an initial context setup request message received from the MME. A determination may be made based on the bearer establishment response message received from 402.
도 5는 본 발명의 다른 실시예에 따른 기지국 및 단말의 동작을 도시한 신호도이다.5 is a signal diagram illustrating operations of a base station and a terminal according to another embodiment of the present invention.
본 발명의 다른 실시예에 따른 제 1 기지국(501)은 상위계층 시그널링에 단말(503)이 제 2 기지국에 연관된 셀에 액세스하기 위한 제 2 기지국에 연관된 셀 식별정보, 제 2 기지국 셀 시스템 정보, 제 2 기지국 전용 MAC 계층 구성 정보 및 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 중 적어도 하나 이상의 정보를 더 포함하여 전송할 수 있다(S530).According to another embodiment of the present invention, the first base station 501 may include cell identification information associated with a second base station for accessing a cell associated with a second base station by a terminal 503, high base station signaling, second base station cell system information, At least one of the second base station dedicated MAC layer configuration information and the second base station cell random access channel preamble may be further included and transmitted (S530).
단말(503)은 제 1 기지국(501)으로부터 전술한 제 2 기지국에 연관된 셀에 액세스하기 위한 관련 정보를 수신하여 제 2 기지국(502)과 업링크 동기화를 위한 랜덤 액세스 절차를 수행할 수 있다(S535).The terminal 503 may receive the relevant information for accessing the cell associated with the second base station from the first base station 501 and perform a random access procedure for uplink synchronization with the second base station 502 ( S535).
또한, 제 1 기지국(501)은 제 2 기지국에 연관된 셀 액세스를 위한 관련 정보를 전술한 상위계층 시그널링에 포함시켜 전송할 수도 있다. In addition, the first base station 501 may include and transmit relevant information for cell access associated with the second base station in the above-described higher layer signaling.
전술한 제 2 기지국(502)과 업링크 동기화를 위한 랜덤 액세스 절차를 수행하는 단계(S535)는 제 2 기지국에 연관된 셀 추가/수정 및 제 2 기지국에 연관된 DRBs(예를 들어, 제 2 기지국 전용 베어러 또는 제 1 기지국과 제 2 기지국 베어러) 추가/수정 단계(S545)보다 먼저 수행될 수 있다. 또는, 전술한 제 2 기지국(502)과 업링크 동기화를 위한 랜덤 액세스 절차를 수행하는 단계(S535)는 제 2 기지국에 연관된 셀 추가/수정 및 제 2 기지국에 연관된 DRBs(예를 들어 제 2 기지국 전용 베어러 또는 제 1 기지국과 제 2 기지국 베어러) 추가/수정 단계(S545) 이후에 수행될 수 있다. 또는, 전술한 제 2 기지국(502)과 업링크 동기화를 위한 랜덤 액세스 절차를 수행하는 단계(S535)는 제 2 기지국에 연관된 셀 추가/수정 및 제 2 기지국에 연관된 DRBs(예를 들어 제 2 기지국 전용 베어러 또는 제 1 기지국과 제 2 기지국 베어러) 추가/수정 단계(S545)와 병행하여 수행될 수 있다. The step S535 of performing the random access procedure for uplink synchronization with the second base station 502 described above may include adding / modifying a cell associated with the second base station and DRBs associated with the second base station (eg, dedicated to the second base station). Bearer or the first base station and the second base station bearer) may be performed before the step (S545). Alternatively, the step S535 of performing the random access procedure for uplink synchronization with the second base station 502 described above may include adding / modifying a cell associated with the second base station and DRBs associated with the second base station (for example, a second base station). Dedicated bearer or the first base station and the second base station bearer) may be performed after the step (S545). Alternatively, the step S535 of performing the random access procedure for uplink synchronization with the second base station 502 described above may include adding / modifying a cell associated with the second base station and DRBs associated with the second base station (for example, a second base station). Dedicated bearer or the first base station and the second base station bearer) may be performed in parallel with the step (S545).
이하에서는, 도 5를 참조하여 제 2 기지국에 연관된 셀 액세스를 위한 관련 정보 전송 및 랜덤 액세스 절차에 대해서 구체적으로 설명한다.Hereinafter, the related information transmission and random access procedure for cell access associated with the second base station will be described in detail with reference to FIG. 5.
제 1 기지국(501)은 제 2 기지국(502)과 사용자 플레인 데이터 전송을 위한 베어러 설정 시그널링 절차를 완료한 후(예를 들어, 베어러 설정 응답 메시지를 수신한 후(S525) 또는 제 2 기지국과 S-GW간 S1 베어러 설정 완료 후 제 2 기지국(502)으로부터 베어러 설정 응답 메시지를 수신한 후(S525)) 상위계층 시그널링(예를 들어, RRC Connection Reconfiguration 메시지)을 통해서 단말의 업링크 동기화 랜덤 액세스를 위한 정보를 전송할 수 있다(S530).After the first base station 501 completes the bearer establishment signaling procedure for transmitting user plane data with the second base station 502 (for example, after receiving a bearer establishment response message (S525) or the second base station and the S) After receiving the bearer setup response message from the second base station 502 after the completion of the S1 bearer setup between the GWs (S525), uplink synchronization random access of the UE is performed through higher layer signaling (for example, an RRC connection reconfiguration message). Information may be transmitted (S530).
제 1 기지국(501)은 단말(503)이 제 2 기지국 셀(스몰 셀)에 업링크 동기화를 수행하고 제 2기지국 셀(스몰 셀)에 전송을 위해 랜덤 액세스 채널(Random Access Chennel, RACH)을 통해 액세스할 수 있도록 하기 위한 셀 식별정보, 셀의 무선자원 구성 정보를 포함하여 전송할 수 있다. The first base station 501 performs a uplink synchronization with the terminal 503 to the second base station cell (small cell) and establishes a random access channel (RACH) for transmission to the second base station cell (small cell). Cell identification information and radio resource configuration information of the cell to be accessible through the transmission may be included.
전술한 제 2 기지국 셀(스몰 셀)의 무선자원 구성 정보는 베어러 설정 응답 메시지를 통해 수신한 제 2 기지국 셀 시스템 정보, 랜덤 액세스 채널 프리앰블, 제 2 기지국 셀(스몰 셀)에서의 동작을 위해 단말 특이적 구성정보, 제 2 기지국 전용 MAC 계층 구성 정보 등을 포함할 수 있다.The above-described radio resource configuration information of the second base station cell (small cell) is used for the operation of the second base station cell system information, the random access channel preamble, and the second base station cell (small cell) received through the bearer setup response message. Specific configuration information, second base station dedicated MAC layer configuration information, and the like.
위에서는 제 2 기지국 셀 액세스를 위한 관련 정보가 상위계층 시그널링을 통해서 전송되는 것을 예를 들어 설명하였으나, 상위계층 시그널링 전송과 별도의 단계로 전송될 수도 있다.In the above description, for example, the related information for accessing the second base station cell is transmitted through higher layer signaling, but may be transmitted in a step separate from the higher layer signaling transmission.
단말(503)은 전술한 제 2 기지국 셀(스몰 셀)의 무선자원 구성정보를 포함한 상위계층 시그널링(예를 들어, RRC 연결 재구성(Connection Reconfiguration) 메시지)를 수신한 후, 제 2 기지국(502) 셀과 RACH 프로시져를 통해 업링크 동기화를 수행한다. 만약, 전용 랜덤 액세스 채널 프리앰블 정보가 포함되어 있다면 "contention-free" 프로시져를 따라서 랜덤 액세스 프로시져를 수행할 수 있다. 또는 전용 랜덤 액세스 채널 프리앰블이 포함되지 않았다면 "contention-based" 프로시져를 따라 램덤 액세스 프로시저를 수행한다(S535).After receiving the upper layer signaling (eg, an RRC connection reconfiguration message) including radio resource configuration information of the second base station cell (small cell), the terminal 503 receives the second base station 502. Uplink synchronization is performed through the cell and the RACH procedure. If the dedicated random access channel preamble information is included, the random access procedure may be performed according to the "contention-free" procedure. Or, if the dedicated random access channel preamble is not included, the random access procedure is performed according to the "contention-based" procedure (S535).
예를 들어, 경쟁 없는(contention-free) 프로시져를 따라 랜덤 액세스 프로시져를 수행하는 경우, 단말은 제 2 기지국 셀에서 생성되어 제 1 기지국을 통해 수신된 RACH 프리앰블을 제 2 기지국 셀로 보내고 이에 대한 RACH response 메시지(RAR)를 제 2 기지국 셀로부터 수신함으로써 램덤 액세스 절차를 수행할 수 있다For example, when performing a random access procedure according to a contention-free procedure, the UE sends a RACH preamble generated in the second base station cell and received through the first base station to the second base station cell, thereby responding to the RACH response. A random access procedure can be performed by receiving a message RAR from a second base station cell.
전술한 상위계층 시그널링(예를 들어, RRC Connection Reconfiguration 메시지)은 하나의 메시지에 추가/수정할 스몰 셀 정보, 추가/수정할 DRBs 정보, 업링크 동기화를 위한 랜덤 액세스 정보를 함께 포함할 수도 있고, 개별적인 메시지에 전술한 하나 이상의 정보를 포함하여 각각 전송할 수도 있다.The above-described higher layer signaling (eg, an RRC connection reconfiguration message) may include small cell information to be added / modified, DRBs information to be added / modified, and random access information for uplink synchronization together in one message, or a separate message. It may also include each of the one or more information described above to be transmitted.
도 6은 본 발명의 또 다른 실시예에 따른 기지국 및 단말의 동작을 도시한 신호도이다.6 is a signal diagram illustrating the operation of a base station and a terminal according to another embodiment of the present invention.
본 발명의 또 다른 실시예에 따른 제 1 기지국(601)이 단말(603)로 상위계층 시그널링을 전송하는 단계는, 제 2 기지국(602)으로부터 베어러 설정 응답 메시지를 수신하는 단계 이전에 전송될 수도 있다(S625).The transmitting of the upper layer signaling to the terminal 603 by the first base station 601 according to another embodiment of the present invention may be transmitted before receiving the bearer establishment response message from the second base station 602. There is (S625).
즉, 앞에서 설명한 바와 같이 상위계층 시그널링은 하나의 메시지에 추가/수정할 스몰 셀(제 2 기지국에 연관된 셀) 정보, 추가/수정할 DRBs 정보, 업링크 동기화를 위한 랜덤 액세스 관련 정보를 함께 포함할 수도 있고, 개별적인 메시지에 전술한 하나 이상의 정보를 포함하여 각각 전송할 수도 있다.That is, as described above, the higher layer signaling may include small cell (cell associated with the second base station) information to be added / modified in one message, DRBs information to be added / modified, and random access related information for uplink synchronization. In addition, each of the above-mentioned information may be included in a separate message and transmitted.
이 경우, 상위계층 시그널링은 베어러 설정 요청 메시지를 제 2 기지국(602)으로 전송한 후 전송될 수도 있고, 베어러 설정 응답 메시지를 수신한 후 전송될 수도 있다.In this case, higher layer signaling may be transmitted after transmitting a bearer establishment request message to the second base station 602 or may be transmitted after receiving a bearer establishment response message.
또한, 업링크 동기화를 위한 랜덤 액세스 관련 정보가 포함되지 않은 경우에도 베어러 설정 응답 메시지를 수신하기 전에 단말(603)로 전송될 수도 있다.In addition, even when the random access related information for uplink synchronization is not included, it may be transmitted to the terminal 603 before receiving the bearer setup response message.
이후, 단말(503)은 제 2 기지국과 설정된 DRBs를 통해 사용자 플레인 데이터를 전송한다(S550).Thereafter, the terminal 503 transmits user plane data through the DRBs established with the second base station (S550).
이상에서는 본 발명의 제 1 실시예에 따른 제 1 기지국이 단말의 사용자 플레인 데이터 전송을 제어하는 방법에 대해서 구체적으로 살펴봤다.In the above, the method of controlling the user plane data transmission of the terminal by the first base station according to the first embodiment of the present invention has been described in detail.
이하에서는, 본 발명의 제 2 실시예에 따른 제 1 기지국이 단말의 사용자 플레인 데이터 전송을 제어하는 방법에 대해서 도면을 참조하여 구체적으로 설명한다.Hereinafter, a method of controlling a user plane data transmission of a terminal by a first base station according to a second embodiment of the present invention will be described in detail with reference to the accompanying drawings.
제 2 실시예: 스몰 셀(제 2 기지국에 연관된 셀) 추가/수정/제거와 제 2 기지국을 통한 DRBs 추가/수정/제거를 개별 프로시저로 수행하는 방법.Second Embodiment A method for performing small cell (cell associated with a second base station) addition / modification / removal and DRBs addition / modification / removal via a second base station as a separate procedure.
본 발명의 또 다른 실시예에 따른 제 1 기지국은 베어러 설정 요청 메시지 전송단계 이전에, 제 2 기지국으로 메시지 타입 정보, 제 2 기지국 식별자 정보, 세컨더리 셀 식별자 정보 및 세컨더리 인덱스 정보 중 적어도 하나 이상의 정보를 포함하는 세컨더리 셀 추가수정 요청 메시지를 전송하는 단계 및 제 2 기지국으로부터 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보 및 제 2 기지국 셀 무선자원구성정보 중 적어도 하나 이상의 정보를 포함하는 세컨더리 셀 추가수정 응답 메시지를 수신하는 단계를 더 포함할 수 있다.According to another embodiment of the present invention, the first base station transmits at least one of message type information, second base station identifier information, secondary cell identifier information, and secondary index information to the second base station before the bearer setup request message transmission step. Transmitting a secondary cell addition modification request message including; and a cell identifier information associated with a second base station, a second base station cell index information, a second base station cell random access channel preamble information, and a second base station cell radio resource configuration from the second base station. The method may further include receiving a secondary cell addition modification response message including at least one piece of information.
도 7은 본 발명의 또 다른 실시예에 따른 기지국 및 단말의 동작을 도시한 신호도이다.7 is a signal diagram illustrating the operation of a base station and a terminal according to another embodiment of the present invention.
도 7을 참고하여 예를 들어 각 단계를 구체적으로 설명한다.For example, each step will be described in detail with reference to FIG. 7.
제 1 기지국(701)은 측정 리포팅 정보 및 데이터 부하 정보 중 적어도 하나 이상의 정보에 기초하여 제 2 기지국 셀의 무선 베어러를 통한 사용자 플레인 데이터 전송을 결정하는 단계를 포함한다(S715).The first base station 701 includes determining user plane data transmission through the radio bearer of the second base station cell based on at least one of the measurement reporting information and the data load information (S715).
즉, 제 1 기지국(701)은 제 2 기지국(702)을 통해 사용자 플레인 데이터를 전송하기 위해 스몰 셀을 추가, 수정 또는 제거하거나 제 2 기지국을 통해 DRBs를 추가, 수정 또는 제거하는 절차를 결정할 수 있다(S715).That is, the first base station 701 may determine a procedure for adding, modifying, or removing small cells or adding, modifying, or removing DRBs through the second base station for transmitting user plane data through the second base station 702. (S715).
이 경우, 제 1 기지국(701)은 MME로부터 수신된 이니셜 컨텍스트 셋업 요청(Initial Context Setup Request) 메시지 내의 정보(예를 들어, E-RAB Level QoS 파라미터), 측정 리포팅 정보 및 데이터 부하 정보 중 적어도 하나 이상의 정보를 이용하여 제 1 기지국(701)을 통해 서비스할 DRB와 제 2 기지국(702)을 통해 서비스할 DRB를 결정할 수 있으며, 제 2 기지국(702)으로 사용자 플레인 데이터 전송을 위한 베어러 설정 시그널링을 개시할 수 있다. 즉, 제 1 기지국(701)은 E-RAB별로 QoS 파라미터(QCI, Allocation and Retention Priority, GBR QoS)에 기초하여 제 1 기지국의 부하, 측정 리포팅 정보 등을 고려하여 제 2 기지국을 통해 전송하고자 하는 E-RAB를 선택할 수 있다. 예를 들어, GBR 베어러 또는 특정 QCI 또는 특정한 Allocation and Retention Priority값을 가진 E-RAB는 제 1 기지국(701)을 통해 전송하고 제 2 기지국(702)으로 DRB설정을 요청하지 않을 수 있다.In this case, the first base station 701 may include at least one of information (eg, an E-RAB Level QoS parameter), measurement reporting information, and data load information in an initial context setup request message received from the MME. The above information may be used to determine a DRB to be serviced through the first base station 701 and a DRB to be serviced through the second base station 702, and bearer configuration signaling for user plane data transmission to the second base station 702. May be initiated. That is, the first base station 701 is to transmit through the second base station in consideration of the load, measurement reporting information, etc. of the first base station based on QoS parameters (QCI, Allocation and Retention Priority, GBR QoS) for each E-RAB. E-RAB can be selected. For example, an E-RAB having a GBR bearer or a specific QCI or a specific Allocation and Retention Priority value may be transmitted through the first base station 701 and not request the DRB setup to the second base station 702.
제 1 기지국(701)은 제 2 기지국(702)으로 스몰 셀 추가/수정을 위한 세컨더리 셀 추가수정 요청 메시지를 보낸다(S720). The first base station 701 sends a secondary cell addition modification request message for small cell addition / modification to the second base station 702 (S720).
또는 제 1 기지국(701)은 측정 리포팅을 기반으로 또는 RRC 연결(Connected) 상태에서 제 1 기지국(701)이 스몰 셀 추가/수정을 결정하면 제 2 기지국(702)으로 스몰 셀 추가/수정을 위한 세컨더리 셀 추가수정 요청 메시지를 보낼 수도 있다(S720).Alternatively, when the first base station 701 determines the small cell addition / modification based on the measurement reporting or in the RRC connected state, the first base station 701 determines the small cell addition / modification to the second base station 702. The secondary cell addition modification request message may be sent (S720).
구체적으로 예를 들면, 전술한 세컨더리 셀 추가수정 요청 메시지는 다음 중 적어도 하나 이상의 정보를 포함할 수 있다.Specifically, for example, the above-described secondary cell addition modification request message may include at least one or more of the following information.
■ 메시지 타입: 메시지의 프로시저 유형을 식별하기 위한 정보를 포함할 수 있다.■ Message Type: May contain information to identify the procedure type of the message.
■ 제 1 기지국 단말 X2AP 식별자(ID): 제 1 기지국에 의해 할당되는 식별자 정보를 포함할 수 있다.■ First base station terminal X2AP identifier (ID): It may include identifier information allocated by the first base station.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자(ID): 제 2 기지국 셀의 E-UTRAN Cell Global Identifier (ECGI)또는 제 2 기지국 셀 PCI(Physical cell ID)에 대한 정보를 포함할 수 있다.■ Cell (small cell) identifier (ID) associated with the second base station: It may include information on the E-UTRAN Cell Global Identifier (ECGI) or the second base station cell PCI (Physical cell ID) of the second base station cell.
■ 제 2 기지국 셀(스몰셀)인덱스: 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국 셀(스몰셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰셀)들 내에서 또는 단말에 제 2 기지국 셀로 구성된 SCells 내에서, 각각의 제 2 기지국 셀(스몰셀) 또는 SCell을 식별하기 위한 인덱스 정보를 포함할 수 있다.■ Second base station cell (small cell) index: in the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured in the terminal SCell or The terminal may include index information for identifying each second base station cell (small cell) or SCell in SCells configured as a second base station cell.
위와 같은 정보를 포함하는 세컨더리 셀 추가수정 요청 메시지를 수신한 제 2 기지국(702)은 제 1 기지국(701)로 세컨더리 셀 추가수정 응답 메시지를 전송할 수 있다(S725).Upon receiving the secondary cell addition modification request message including the above information, the second base station 702 may transmit a secondary cell addition modification response message to the first base station 701 (S725).
구체적으로 설명하면, 제 1 기지국으로부터 스몰 셀 추가/수정 요청 정보를 포함하는 세컨더리 셀 추가수정 요청 메시지를 수신한 제 2 기지국(702)은 세컨더리 셀 추가수정 응답 메시지를 제 1 기지국(701)으로 전송할 수 있다(S725).Specifically, the second base station 702 receiving the secondary cell addition modification request message including the small cell addition / modification request information from the first base station transmits the secondary cell addition modification response message to the first base station 701. It may be (S725).
구체적으로 예를 들면, 전술한 세컨더리 셀 추가수정 요청 메시지는 다음 중 적어도 하나 이상의 정보를 포함할 수 있다.Specifically, for example, the above-described secondary cell addition modification request message may include at least one or more of the following information.
■ 메시지 타입: 메시지의 프로시저 유형을 식별하기 위한 정보를 포함할 수 있다.■ Message Type: May contain information to identify the procedure type of the message.
■ 제 1 기지국 단말 X2AP 식별자(ID): 제 1 기지국에 의해 할당되는 식별자 정보를 포함할 수 있다.■ First base station terminal X2AP identifier (ID): It may include identifier information allocated by the first base station.
■ 제 2 기지국 단말 X2AP 식별자(ID): 제 2 기지국에 의해 할당되는 식별자 정보를 포함할 수 있다.■ Second base station terminal X2AP identifier (ID): It may include identifier information allocated by the second base station.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자: 제 2 기지국에 연관된 셀의 PCI와 ARFCN(Absolute Radio Frequency Channel Number)에 대한 정보를 포함할 수 있다.■ Cell (small cell) identifier associated with the second base station: It may include information about PCI and Absolute Radio Frequency Channel Number (ARFCN) of the cell associated with the second base station.
■ 제 2 기지국 셀(스몰 셀)인덱스: 단말(703)에 구성된 SCells 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 제 2 기지국 셀로 구성된 SCells 내에서, 각각의 제 2 기지국 셀(스몰 셀) 또는 SCell을 식별하기 위해 사용되는 인덱스로 제 2 기지국(702)에 의해 결정 또는 할당될 수 있다.■ Second base station cell (small cell) index: in the SCells configured in the terminal 703 or in the second base station cells (small cells) configured in the terminal SCell, or in the SCells configured in the terminal second cell, respectively An index used to identify a second base station cell (small cell) or an SCell of may be determined or assigned by the second base station 702.
다른 방법으로 제 2 기지국 셀(스몰 셀) 인덱스 또는 SCell 인덱스는 제 1 기지국(701)이 결정 또는 할당하여 세컨더리 셀 추가수정 요청 메시지에 포함시켜 전송할 수 있다. 이 때, 세컨더리 셀 추가수정 응답 메시지에는 포함하지 않을 수 있다.Alternatively, the second base station cell (small cell) index or SCell index may be determined or allocated by the first base station 701 and included in the secondary cell addition modification request message. At this time, the secondary cell addition modification response message may not be included.
또 다른 방법으로는 제 2 기지국 셀 인덱스 또는 SCell인덱스는 제 1 기지국(701)이 결정 또는 할당하여 세컨더리 셀 추가수정 요청 메시지에 포함시켜 전송할 수 있다. 이 때, 세컨더리 셀 추가수정 응답 메시지에도 포함될 수 있다.Alternatively, the second base station cell index or SCell index may be determined or allocated by the first base station 701 to be included in the secondary cell addition modification request message and transmitted. At this time, it may be included in the secondary cell addition modification response message.
또 다른 방법으로 제 2 기지국 셀 인덱스 또는 SCell 인덱스는 기존 SCell 인덱스로 사용하는 값(예를 들어, 1~7)이 아닌 값(예를 들어, 8)을 사용할 수 있으며, 이러한 경우 전술한 세컨더리 셀 추가수정 요청 메시지와 세컨더리 셀 추가수정 응답 메시지 모두에서 포함되지 않을 수도 있다. 또는 전술한 세컨더리 셀 추가수정 요청 메시지 및/또는 세컨더리 셀 추가수정 응답 메시지에 포함할 수 있다.Alternatively, the second base station cell index or the SCell index may use a value (for example, 8) that is not a value (for example, 1 to 7) used as the existing SCell index, in which case the above-described secondary cell It may not be included in both the addition request message and the secondary cell addition response message. Or it may include in the above-described secondary cell addition modification request message and / or secondary cell addition modification response message.
기존 SCell 인덱스로 사용하는 값이 아닌 다른 값을 사용하도록 하기 위해 현재 1에서 7까지의 정수 값을 가질 수 있는 SCell 인덱스를 1~14까지의 정수 값을 가질 수 있도록 하고, 1에서7까지의 정수값은 제 1 기지국의 SCell들을 위한 인덱스로 8~14는 제 2 기지국을 위한 인덱스로 사용할 수 있다. 또 다른 방법으로 제 1 기지국의 SCell인덱스와 제 2 기지국의 SCell인덱스를 구분할 수 있도록, SCell인덱스 및 제 2 기지국 식별자(또는 제 2 기지국의 셀 식별자) 필드를 함께 보내도록 할 수도 있다In order to use a value other than the value used as the existing SCell index, the SCell index that can currently have an integer value from 1 to 7 can be an integer value from 1 to 14, and an integer from 1 to 7 The value may be used as an index for SCells of the first base station and 8 to 14 as an index for the second base station. Alternatively, the SCell index and the second base station identifier (or cell identifier of the second base station) field may be sent together so that the SCell index of the first base station and the SCell index of the second base station can be distinguished.
■ 스몰셀공통무선자원구성정보: 단말이 제 2 기지국에 연관된 셀에서 동작하기 위해 필수적인(essential) 정보로 시스템 구성정보에 해당되는 물리계층 구성 파라미터 또는 물리계층 구성 파라미터와 MAC계층 구성 파라미터에 대한 정보를 포함할 수 있다.■ Small cell common radio resource configuration information: information on a physical layer configuration parameter or a physical layer configuration parameter and a MAC layer configuration parameter corresponding to the system configuration information as essential information for the terminal to operate in a cell associated with the second base station. It may include.
■ 스몰셀전용무선자원구성정보: 제 2 기지국에 연관된 셀에 대한 단말 특이적(UE-specific) 구성정보(physical channel configuration) 또는 제 2 기지국에 연관된 셀에 대한 단말 특이적 구성정보(physical channel configuration)와 MAC 계층 구성 파라미터(예를 들어, mac-MainConfig)에 대한 정보를 포함할 수 있다.■ Small cell dedicated radio resource configuration information: UE-specific physical channel configuration for the cell associated with the second base station or terminal-specific configuration information for the cell associated with the second base station (physical channel configuration) ) And MAC layer configuration parameters (eg, mac-MainConfig).
■ 선택적으로 전용 랜덤 액세스 채널(Random Access Channel, RACH) 프리앰블 정보: 제 2 기지국의 셀을 통해 경쟁 없는(contention free) 랜덤 액세스 프로시져를 수행하기 위한 프리앰블에 관련된 정보를 포함할 수 있다.Optionally, Random Random Channel (RACH) preamble information: may include information related to the preamble for performing a contention free random access procedure through the cell of the second base station.
위에서 설명한 바와 같이 제 1 기지국(701)은 전술한 정보를 포함하는 세컨더리 셀 추가수정 요청 메시지를 제 2 기지국(702)으로 전송하고, 전술한 정보를 포함하는 세컨더리 셀 추가수정 응답 메시지를 수신할 수 있다.As described above, the first base station 701 may transmit the secondary cell addition modification request message including the above information to the second base station 702 and receive the secondary cell addition modification response message including the above information. have.
제 1 기지국(701)이 제 2 기지국(702)을 통한 사용자 플레인 데이터 전송을 결정하면(예를 들어, 제 2 기지국에 연관된 셀에 DRBs를 추가/수정을 결정하면), 시큐리티 액티베이션 프로시저를 개시하기 전 또는 후에 사용자 데이터를 전송하기 위해 제 2 기지국(702)으로 베어러 설정 요청 메시지를 전송한다(S730). 또는 RRC Connected 상태에서 제 1 기지국(701)은 제 2 기지국에 연관된 셀(스몰셀)을 통해 사용자 데이터를 전송하기 위해 사용자 데이터를 전송하기 위해 제 2 기지국(702)으로 베어러 설정 요청 메시지를 전송한다(S730). 또는 제 1 기지국(701)은 제 1 기지국과 제 2 기지국을 통해 사용자 데이터를 전송하기 위해 제 2 기지국(702)으로 베어러 설정 요청 메시지를 전송한다(S730).If the first base station 701 determines user plane data transmission through the second base station 702 (eg, determines to add / modify DRBs to a cell associated with the second base station), it initiates a security activation procedure. Before or after the transmission of the bearer request message to the second base station 702 to transmit the user data (S730). Alternatively, in the RRC Connected state, the first base station 701 transmits a bearer setup request message to the second base station 702 to transmit user data for transmitting user data through a cell (small cell) associated with the second base station. (S730). Alternatively, the first base station 701 transmits a bearer setup request message to the second base station 702 in order to transmit user data through the first base station and the second base station (S730).
제 2 기지국(702)을 통한 사용자 플레인 데이터 전송을 위한 베어러 설정 요청 메시지는 다음 중 적어도 하나 이상의 정보를 포함할 수 있다.The bearer establishment request message for user plane data transmission through the second base station 702 may include at least one of the following information.
베어러 설정 요청 메시지에 포함되는 정보를 예를 들어 설명하면 아래와 같다.For example, the information included in the bearer establishment request message will be described below.
■ 메시지 타입: 메시지의 프로시저 유형을 식별하기 위한 정보를 포함할 수 있다.■ Message Type: May contain information to identify the procedure type of the message.
■ 제 1 기지국 단말 X2AP 식별자(ID): 제 1 기지국에 의해 할당되는 식별자 정보를 포함할 수 있다.■ First base station terminal X2AP identifier (ID): It may include identifier information allocated by the first base station.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자(ID): 제 2 기지국에 연관된 셀의 E-UTRAN Cell Global Identifier (ECGI) 또는 제 2 기지국에 연관된 셀 PCI(Physical Cell ID) 정보를 포함할 수 있다.■ Cell (Small Cell) Identifier (ID) associated with the second base station: may include E-UTRAN Cell Global Identifier (ECGI) of the cell associated with the second base station or cell PCI (Physical Cell ID) information associated with the second base station. have.
■ 제 2 기지국 셀(스몰셀)인덱스: 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국 셀(스몰셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰셀)들 내에서 또는 단말에 제 2 기지국 셀로 구성된 SCells 내에서, 각각의 제 2 기지국 셀(스몰셀) 또는 SCell을 식별하기 위한 인덱스 정보를 포함할 수 있다.■ Second base station cell (small cell) index: in the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured in the terminal SCell or The terminal may include index information for identifying each second base station cell (small cell) or SCell in SCells configured as a second base station cell.
■ 단말 컨텍스트 정보: 단말 컨텍스트 정보는 아래와 같은 정보를 포함할 수 있다.■ Terminal context information: The terminal context information may include the following information.
1) UE Security capabilities: 단말 내에 암호화와 무결성 보호를 위해 지원되는 알고리즘에 대한 정보를 포함한다. 또는 단말 내에 암호화를 위해 지원되는 알고리즘에 대한 정보를 포함한다. 또는 단말 내에 사용자 플레인 데이터의 암호화를 위해 지원되는 알고리즘에 대한 정보를 포함한다. 또 다른 방법으로 UE Security capabilities 정보는 전술한 베어러 설정 요청 메시지에 포함시키지 않고 제 1 기지국에서만 관리할 수도 있다1) UE Security capabilities: Contains information about the algorithms supported for encryption and integrity protection in the terminal. Or information about an algorithm supported for encryption in the terminal. Or information about an algorithm supported for encryption of user plane data in the terminal. Alternatively, the UE Security capabilities information may be managed only at the first base station without being included in the bearer establishment request message described above.
2) AS Security Information 또는 AS Security Key: 제 2 기지국에서 사용자 플레인 데이터에 대한 암호화 키(KUPenc) 정보를 포함한다. 또는 암호화 키(KUPenc)를 유도하기 위한 기지국 키(KeNB) 정보를 포함한다. 전술한 정보는 제 1 기지국의 KUPenc 또는 KeNB와 동일한 값을 사용할 수도 있고 다른 값을 사용할 수도 있다.2) AS Security Information or AS Security Key: Includes encryption key (K UPenc ) information for user plane data at the second base station. Or base station key (K eNB ) information for deriving an encryption key K UPenc . The above information may use the same value as K UPenc or K eNB of the first base station or may use a different value.
3) 단말 총 최대 비트 전송율(UE Aggregate Maximum Bit Rate, UE-AMBR): 단말 당 모든 Non-GBR 베어러들에 적용하는 최대 비트 전송율 집합으로 상향 또는 하향 방향으로 정의되며 MME에 의해 제 1 기지국으로 제공된 값이다. 또는 예를 들어, 제 1 기지국에서 제 2 기지국을 통해 사용자 플레인 데이터를 포워딩하는 경우에 UE-AMBR 정보는 전술한 베어러 설정 요청 메시지에 포함시키지 않고 제 1 기지국에서만 관리할 수도 있다. 만약, 특정 단말에 구성된 모든 Non-GBR 베어러들을 제 2 기지국을 통해 구성하는 경우 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate(UE-AMBR))를 포함할 수 있다. 또는 만약 특정 단말에 구성된 적어도 하나 이상의 Non-GBR 베어러들을 제 2 기지국을 통해 구성하는 경우, 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate, (UE-AMBR))를 포함할 수 있다. 또는 만약 특정 단말에 구성된 적어도 하나 이상의 Non-GBR 베어러들을 제 2 기지국을 통해 구성하는 경우, 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate, UE-AMBR) 및 제 2 기지국을 통한 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate, UE-AMBR)의 처리비율 정보를 포함할 수 있다.3) UE Aggregate Maximum Bit Rate (UE-AMBR): A maximum bit rate set applied to all Non-GBR bearers per UE, defined in an up or down direction and provided to a first base station by an MME. Value. Or, for example, in the case where the first base station forwards user plane data through the second base station, the UE-AMBR information may be managed only by the first base station without being included in the above-described bearer setup request message. If all the non-GBR bearers configured in a specific terminal are configured through the second base station, the terminal may include a UE Aggregate Maximum Bit Rate (UE-AMBR). Alternatively, if at least one non-GBR bearer configured in a specific UE is configured through the second base station, the UE may include a UE Aggregate Maximum Bit Rate (UE-AMBR). Alternatively, if at least one non-GBR bearer configured in a specific terminal is configured through the second base station, the UE Aggregate Maximum Bit Rate (UE-AMBR) and the terminal total maximum bit rate through the second base station It may include processing rate information of (UE Aggregate Maximum Bit Rate, UE-AMBR).
4) 제 2 기지국을 통한 E-RABs(E-UTRAN Radio Access Bearers) 셋업 리스트(E-RABs To Be Setup List) 정보: E-RABs 셋업 아이템을 포함한다. E-RABs 셋업 아이템은 E-RAB ID, E-RAB Level QoS 파라미터, GTP Tunnel Endpoint 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.4) E-RABs To Be Setup List (E-RABs) Setup List (E-RABs To Be Setup List) information through the second base station: Contains the E-RABs setup item. The E-RABs setup item may include at least one or more of an E-RAB ID, an E-RAB Level QoS parameter, and GTP Tunnel Endpoint information.
전술한 E-RABs 셋업 아이템에 포함될 수 있는 정보를 상세히 살펴보면, E-RAB ID는 단말에 대한 무선 액세스 베어러를 식별하기 위한 정보를 포함한다. 또한, E-RAB Level QoS 파라미터는 E-RAB에 적용되는 QoS(Quality of Service) 정보로 QCI, Allocation and Retention Priority, GBR QoS 정보를 포함한다. 또한, 일 예로, GTP Tunnel Endpoint는 도 2와 같이 제 1 기지국과 제 2 기지국 간의 인터페이스를 통해 사용자 플레인 데이터 전송하는 경우, 제 1 기지국과 제 2 기지국 간 사용자 플레인 데이터 전송을 위한 베어러의 끝점(endpoint)으로 제 1 기지국의 IP주소인 Transport Layer Address, GTP TEID(Tunnel Endpoint ID)를 포함할 수 있다. 또는 다른 예로, GTP Tunnel Endpoint는 도 3과 같이 S-GW와 제 2 기지국 간 인터페이스를 통해 사용자 플레인 데이터를 전송하는 경우에는 S-GW와 제 2 기지국 간의 끝점으로 S-GW의 IP주소인 Transport Layer Address, GTP TEID(Tunnel Endpoint ID)를 포함할 수 있다.Looking at the information that may be included in the aforementioned E-RABs setup item in detail, the E-RAB ID includes information for identifying a radio access bearer for the terminal. In addition, the E-RAB Level QoS parameter is Quality of Service (QoS) information applied to the E-RAB and includes QCI, Allocation and Retention Priority, and GBR QoS information. Also, as an example, when the GTP tunnel endpoint transmits user plane data through an interface between the first base station and the second base station, as shown in FIG. 2, an endpoint of a bearer for transmitting user plane data between the first base station and the second base station. ) May include a transport layer address, a GTP TEID (Tunnel Endpoint ID), which is an IP address of the first base station. Alternatively, when the user plane data is transmitted through the interface between the S-GW and the second base station as shown in FIG. 3, the GTP tunnel endpoint is an transport layer that is an IP address of the S-GW as an endpoint between the S-GW and the second base station. It may include an address and a GTP Tunnel Endpoint ID (TEID).
5) 단말 캐퍼빌리티(Capability) 정보: MME를 통해 수신된 단말 컨텍스트 정보에 포함된 단말 캐퍼빌리티 정보 중 제 2 기지국을 통한 사용자 데이터 전송을 위한 무선자원을 구성하는데 필요한 단말 캐퍼빌리티 정보를 포함한다. 예를 들어, 단일 송수신(single Tx/Rx) 또는 복수 송수신(multi Tx/Rx)) 정보 등을 포함한다.5) UE Capability Information: Contains UE capability information necessary for configuring radio resources for user data transmission through a second base station among UE capability information included in UE context information received through the MME. For example, it includes single Tx / Rx or multi Tx / Rx information.
위에서 살펴본 바와 같이 베어러 설정 요청 메시지는 위에서 일 예를 들어 설명한 각 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.As described above, the bearer establishment request message may include at least one or more pieces of information described above as an example.
본 발명의 일 실시예에 따른 제 1 기지국(701)은 제 2 기지국(702)으로부터 베어러 설정 응답 메시지를 수신할 수 있다(S735).The first base station 701 according to an embodiment of the present invention may receive a bearer setup response message from the second base station 702 (S735).
제 1 기지국(701)으로부터 사용자 플레인 데이터 전송을 위한 베어러 설정 요청 메시지를 수신한 제 2 기지국(702)은 베어러 설정 응답 메시지를 제 1 기지국(701)으로 전송한다(S735).Upon receiving the bearer setup request message for user plane data transmission from the first base station 701, the second base station 702 transmits a bearer setup response message to the first base station 701 (S735).
구체적으로 일 예를 들면, 베어러 설정 응답 메시지는 다음 중 하나 이상의 정보를 포함할 수 있다.Specifically, for example, the bearer establishment response message may include one or more of the following information.
■ 메시지 타입: 메시지의 프로시져 유형을 식별하기 위한 정보이다.■ Message Type: Information that identifies the procedure type of the message.
■ 제 1 기지국 단말 X2AP 식별자(ID): 제 1 기지국에 의해 할당되는 식별자 정보이다.First base station terminal X2AP identifier (ID): Identifier information allocated by the first base station.
■ 제 2 기지국 단말 X2AP 식별자(ID): 제 2 기지국에 의해 할당되는 식별자 정보이다.Second base station terminal X2AP identifier (ID): Identifier information allocated by the second base station.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자(ID): 제 2 기지국에 연관된 셀의 E-UTRAN Cell Global Identifier (ECGI) 또는 제 2 기지국에 연관된 셀 PCI(Physical Cell ID) 정보를 포함한다.■ Cell (Small Cell) Identifier (ID) associated with the second base station: E-UTRAN Cell Global Identifier (ECGI) of the cell associated with the second base station or cell PCI (Physical Cell ID) information associated with the second base station.
■ 제 2 기지국 셀(스몰셀)인덱스: 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국 셀(스몰셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰셀)들 내에서 또는 단말에 제 2 기지국 셀로 구성된 SCells 내에서, 각각의 제 2 기지국 셀(스몰셀) 또는 SCell을 식별하기 위한 인덱스 정보를 포함한다.■ Second base station cell (small cell) index: in the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured in the terminal SCell or The terminal includes index information for identifying each second base station cell (small cell) or SCell in SCells configured as a second base station cell.
■ 제 2 기지국을 통한 E-RABs(E-UTRAN Radio Access Bearers) 수락 리스트(E-RABs Admitted List) 정보: E-RABs 수락 아이템 정보를 포함할 수 있다. E-RABs 수락 아이템 정보는 E-RAB ID, GTP Tunnel Endpoint, DRB 식별자(DRB ID), PDCP 구성정보(PDCP-Config), RLC 구성정보(RLC-Config), 논리채널식별자(logicalChannelIdentity), 논리채널구성정보(logicalChannelConfig) 및 물리채널구성정보(PhysicalConfigDedicated) 중 적어도 하나 이상의 정보를 포함할 수 있다.■ E-RARANs Admitted List (E-RABs) Admitted List (E-RABs) Admitted List information through the second base station: E-RABs may include E-RABs accepted item information. E-RABs acceptance item information includes E-RAB ID, GTP Tunnel Endpoint, DRB Identifier (DRB ID), PDCP Configuration Information (PDCP-Config), RLC Configuration Information (RLC-Config), Logical Channel Identity, Logical Channel It may include at least one of configuration information (logicalChannelConfig) and physical channel configuration information (PhysicalConfigDedicated).
구체적으로 E-RAB ID는 단말에 대한 무선 액세스 베어러를 식별하기 위한 정보를 포함한다. 또한, 일 예로, GTP Tunnel Endpoint는 도 2와 같이 제 1 기지국과 제 2 기지국 간 인터페이스를 통해 사용자 플레인 데이터 전송하는 경우, 제 1 기지국과 제 2 기지국 간의 베어러 끝점(endpoint)이다. 또는 다른 예로, GTP Tunnel Endpoint는 도 3과 같이 S-GW와 제 2 기지국 간 인터페이스를 통해 사용자 플레인 데이터를 전송하는 경우에는 S-GW와 제 2 기지국 간의 끝점으로 제 2 기지국의 IP주소인 Transport Layer Address, GTP TEID(Tunnel Endpoint ID)를 포함한다. PDCP 구성정보(PDCP-Config)는 도 3과 같이 S-GW와 제 2 기지국 간 인터페이스를 통해 사용자 플레인 데이터를 전송하는 경우 제 2 기지국을 통해 전송하는 무선 베어러를 위한 PDCP 계층 구성정보를 나타낸다. RLC 구성정보(RLC-Config)는 제 2 기지국을 통해 전송하는 무선 베어러를 위한 RLC 계층 구성정보를 나타낸다. 논리채널식별자(logicalChannelIdentity)와 논리채널구성정보(logicalChannelConfig)는 제 2 기지국을 통해 전송하는 무선 베어러를 위한 논리채널식별자(logicalChannelIdentity) 및 논리채널구성정보(logicalChannelConfig)를 나타낸다. 물리채널구성정보(PhysicalConfigDedicated)는 제 2 기지국을 통해 전송하는 무선 베어러를 위한 물리 계층 구성정보를 나타낸다Specifically, the E-RAB ID includes information for identifying a radio access bearer for the terminal. In addition, as an example, the GTP tunnel endpoint is a bearer endpoint between the first base station and the second base station when user plane data is transmitted through an interface between the first base station and the second base station as shown in FIG. 2. Alternatively, when the user plane data is transmitted through the interface between the S-GW and the second base station as shown in FIG. 3, the GTP tunnel endpoint is an end point between the S-GW and the second base station. Address, GTP TEID (Tunnel Endpoint ID) is included. The PDCP configuration information (PDCP-Config) indicates PDCP layer configuration information for a radio bearer transmitted through the second base station when transmitting user plane data through the interface between the S-GW and the second base station as shown in FIG. 3. RLC configuration information (RLC-Config) indicates RLC layer configuration information for a radio bearer transmitted through a second base station. The logical channel identifier (logicalChannelIdentity) and logical channel configuration information (logicalChannelConfig) represents a logical channel identifier (logicalChannelIdentity) and logical channel configuration information (logicalChannelConfig) for the radio bearer transmitted through the second base station. Physical channel configuration information (PhysicalConfigDedicated) represents the physical layer configuration information for the radio bearer transmitted through the second base station
■ E-RABs 미수락 리스트 정보: 제 2 기지국의 부하나 상태 등에 따라 제 2 기지국을 통해 요청된 무선베어러 중 처리할 수 없는 무선베어러 리스트 정보를 포함한다. 예를 들어, 트래픽 부하가 높은 경우 모든 요청 베어러를 처리하지 못하는 경우 제 2 기지국은 모든 요청 베어러 리스트를 미수락 리스트에 포함하거나 또는 메시티 타입을 달리하는 메시지(예를 들어, 거절 메시지)를 전달할 수 있다■ E-RABs non-acceptance list information: It includes radio bearer list information that cannot be processed among the radio bearers requested through the second base station according to the load or state of the second base station. For example, if the traffic load is high and all request bearers cannot be processed, the second base station may include all request bearer lists in the unacceptable list or forward a message of different message types (eg, rejection message). Can
■ 선택적으로 전용 랜덤 액세스 채널(Random Access Channel, RACH) 프리앰블 정보: 제 2 기지국의 셀을 통해 경쟁 없는(contention free) 랜덤 액세스 프로시져를 수행하기 위한 프리앰블 정보를 포함한다.Optionally, Random Random Channel (RACH) preamble information: includes preamble information for performing a contention free random access procedure through the cell of the second base station.
베어러 설정 응답 메시지는 위와 같은 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.The bearer establishment response message may include at least one or more of the above information.
제 1 기지국(701)은 상위계층 시그널링(예를 들어, RRC 연결 재구성(Connection Reconfiguration) 메시지)에 추가/수정할 제 2 기지국에 연관된 셀 정보를 포함하여 단말(703)로 전송할 수 있다(S740).The first base station 701 may transmit cell information associated with the second base station to be added / modified to higher layer signaling (eg, an RRC connection reconfiguration message) to the terminal 703 (S740).
단말(703)은 수신된 상위계층 시그널링에 포함된 정보에 기초하여 제 2 기지국에 연관된 셀을 추가/수정할 수 있다.The terminal 703 may add / modify a cell associated with the second base station based on the information included in the received higher layer signaling.
추가/수정할 제 2 기지국에 연관된 셀 정보는 전술한 세컨더리 셀 추가수정 응답 메시지에 포함된 정보에 기초하여 설정될 수 있다.Cell information associated with the second base station to be added / modified may be set based on the information included in the above-described secondary cell addition modification response message.
이하에서는, 추가/수정할 제 2 기지국에 연관된 셀 정보에 포함될 수 있는 정보를 구체적으로 예를 들어 살펴본다.Hereinafter, information that may be included in cell information associated with a second base station to be added / modified will be described in detail.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자: 제 2 기지국 스몰 셀의 PCI(Physical Cell ID), ARFCN(Absolute Radio Frequency Channel)에 대한 정보를 포함할 수 있다.■ Cell (small cell) identifier associated with the second base station: It may include information about the Physical Cell ID (PCI), the Absolute Radio Frequency Channel (ARFCN) of the second base station small cell.
■ 제 2 기지국 셀(스몰 셀)인덱스: 단말에 구성된 SCells 또는 제 2 기지국 셀 내에서 또는 단말에 구성된 제 2 기지국 셀(스몰셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 제 2 기지국 셀(스몰 셀)로 구성된 SCells 내에서, 각각의 제 2 기지국 셀(스몰 셀) 또는 SCell을 식별하기 위해 사용되는 인덱스 정보를 포함한다.■ Second base station cell (small cell) index: second base station cell (small cell) configured in SCells configured in the terminal or second base station cell (small cells) configured in the terminal or configured in the terminal or SCell in the terminal ) Or index information used to identify each second base station cell (small cell) or SCell in SCells configured as a second base station cell (small cell) in the terminal.
전술한 인덱스 정보는 제 2 기지국에 의해 결정 또는 할당될 수 있다.The above-described index information may be determined or assigned by the second base station.
다른 방법으로 제 2 기지국 셀(스몰 셀) 인덱스는 제 1 기지국이 결정 또는 할당하여 세컨더리 셀 추가수정 요청 메시지에 포함하여 보내고, 세컨더리 셀 추가수정 응답 메시지에는 포함되지 않을 수 있다.Alternatively, the second base station cell (small cell) index may be determined or assigned by the first base station to be included in the secondary cell addition modification request message and may not be included in the secondary cell addition modification response message.
또 다른 방법으로 제 2 기지국 셀(스몰 셀) 인덱스는 제 1 기지국이 결정 또는 할당하여 세컨더리 셀 추가수정 요청 메시지에 포함하여 전송할 수 있다. 그리고 제 2 기지국이 이를 확인한 후 세컨더리 셀 추가수정 응답 메시지에 포함될 수도 있다.Alternatively, the second base station cell (small cell) index may be determined or allocated by the first base station and included in the secondary cell addition modification request message. After the second base station confirms this, it may be included in the secondary cell addition modification response message.
또 다른 방법으로 제 2 기지국 셀(스몰 셀) 인덱스 또는 SCell 인덱스는 기존 SCell 인덱스로 사용하는 값(예를 들어, 1~7)이 아닌 값(예를 들어, 8)을 사용할 수 있으며, 이러한 경우 세컨더리 셀 추가수정 요청 메시지와 세컨더리 셀 추가수정 응답 메시지 모두에 포함되지 않을 수도 있다.Alternatively, the second base station cell (small cell) index or SCell index may use a value (for example, 8) that is not a value (for example, 1 to 7) that is used as an existing SCell index. It may not be included in both the secondary cell addition modification request message and the secondary cell addition modification response message.
또 다른 방법으로 제 2 기지국 셀(스몰 셀) 인덱스 또는 SCell 인덱스는 기존 SCell 인덱스로 사용하는 값(예를 들어, 1~7)이 아닌 값(예를 들어, 8)을 사용할 수 있으며, 세컨더리 셀 추가수정 요청 메시지 및/또는 세컨더리 셀 추가수정 응답 메시지에 포함할 수도 있다.Alternatively, the second base station cell (small cell) index or SCell index may use a value (for example, 8) that is not a value (for example, 1 to 7) used as the existing SCell index, and the secondary cell. It may be included in the additional modification request message and / or the secondary cell additional modification response message.
기존 SCell 인덱스로 사용하는 값이 아닌 다른 값을 사용하도록 하기 위해 현재 1에서 7까지의 정수 값을 가질 수 있는 SCell 인덱스를 1~14까지의 정수 값을 가질 수 있도록 하고, 1에서 7까지의 정수값은 제 1 기지국의 SCell들을 위한 인덱스로 8~14는 제 2 기지국을 위한 인덱스로 사용할 수 있다. 또 다른 방법으로 제 1 기지국의 SCell인덱스와 제 2 기지국의 SCell인덱스를 구분할 수 있도록 SCell인덱스 및 제 2 기지국 식별자(또는 제 2 기지국의 셀 식별자) 필드를 함께 보내도록 할 수 있다In order to use a value other than the value used as the existing SCell index, the SCell index that can currently have an integer value from 1 to 7 can be an integer value from 1 to 14, and an integer from 1 to 7 The value may be used as an index for SCells of the first base station and 8 to 14 as an index for the second base station. Alternatively, the SCell index and the second base station identifier (or cell identifier of the second base station) field may be sent together so that the SCell index of the first base station and the SCell index of the second base station can be distinguished.
■ 스몰셀공통무선자원구성정보: 단말이 제 2 기지국에 연관된 셀에서 동작하기 위해 필수적인(essential)정보로 시스템 구성정보에 해당되는 물리계층 구성 파라미터 또는 물리계층 구성 파라미터와 MAC계층 구성 파라미터를 포함할 수 있다.■ Small cell common radio resource configuration information: essential information for the UE to operate in a cell associated with the second base station, and includes physical layer configuration parameters or physical layer configuration parameters and MAC layer configuration parameters corresponding to the system configuration information. Can be.
■ 스몰셀전용무선자원구성정보: 제 2 기지국에 연관된 셀에서 동작을 위한 단말 특이적(UE-specific) 구성 정보(physical channel configuration) 또는 단말 특이적 구성정보와 MAC 계층 구성 파라미터(예를 들어, mac-MainConfig)를 포함할 수 있다.■ Small cell dedicated radio resource configuration information: UE-specific physical channel configuration or UE-specific configuration information and MAC layer configuration parameters (for example, for operation in the cell associated with the second base station) mac-MainConfig).
단말(703)은 위와 같은 정보를 포함하는 상위계층 시그널링을 수신하여 제 2 기지국에 연관된 셀(스몰 셀)을 추가/수정할 수 있다(S745). The terminal 703 may add / modify a cell (small cell) associated with the second base station by receiving higher layer signaling including the above information (S745).
이하에서는, 단말이 제 2 기지국과 데이터 무선 베어러(DRB)를 설정하기 위한 정보를 수신하는 경우를 구체적으로 살펴본다.Hereinafter, a case in which the terminal receives information for establishing a data radio bearer (DRB) with the second base station will be described in detail.
제 1 기지국(701)은 제 2 기지국(702)과 사용자 플레인 데이터 전송을 위한 베어러 설정 시그널링 절차를 완료한 후(예를 들어, 베어러 설정 응답 메시지를 수신한 후), 상위계층 시그널링(예를 들어, RRC 연결 재구성 메시지)에 추가/수정할 DRBs 정보를 포함하여 단말(703)로 전송할 수도 있다(S740).After the first base station 701 completes the bearer establishment signaling procedure for transmitting user plane data with the second base station 702 (eg, after receiving a bearer establishment response message), higher layer signaling (eg, , RRC connection reconfiguration message) may be transmitted to the terminal 703 including the DRBs information to be added / modified (S740).
단말(703)은 제 2 기지국(702)과 DRBs를 추가/수정하거나 또는 제 1 기지국(701)의 DRBs를 제 2 기지국의 DRBs로 수정할 수도 있다. 또는 단말(703)은 제 1 기지국(701)의 DRBs를 제 1 기지국(701)과 제 2 기지국(702)을 통한 DRBs로 수정할 수 있다The terminal 703 may add / modify the DRBs with the second base station 702 or may modify the DRBs of the first base station 701 with the DRBs of the second base station. Alternatively, the terminal 703 may modify the DRBs of the first base station 701 into DRBs through the first base station 701 and the second base station 702.
전술한 추가/수정할 DRBs 정보는 다음 중 적어도 하나 이상의 정보를 포함할 수 있다.The aforementioned DRBs information to be added / modified may include at least one or more of the following information.
■ EPS-Beareridentity: EPS 베어러 식별자로 E-RAB ID 정보를 포함할 수 있다.■ EPS-Beareridentity: EPS bearer identifier may include E-RAB ID information.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자: 제 2 기지국에 연관된 셀의 PCI(Physical Cell ID), ARFCN(Absolute Radio n Frequency Channel)에 대한 정보를 포함할 수 있다.■ Cell (small cell) identifier associated with the second base station: It may include information about the Physical Cell ID (PCI), the Absolute Radio n Frequency Channel (ARFCN) of the cell associated with the second base station.
■ 제 2 기지국 셀(스몰 셀) 인덱스: 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 제 2 기지국 셀(스몰 셀)로 구성된 SCells 내에서, 각각의 제 2 기지국 셀(스몰 셀) 또는 SCell을 식별하기 위해 사용되는 인덱스 정보를 포함한다.■ Second base station cell (small cell) index: within the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured with the SCell in the terminal or It includes index information used to identify each second base station cell (small cell) or SCell in SCells configured as a second base station cell (small cell) in the terminal.
■ DRB-ID: 제 2 기지국으로부터 수신한 DRB-ID 정보를 포함한다.DRB-ID: Contains DRB-ID information received from the second base station.
■ PDCP-Config: 제 2 기지국으로부터 수신한 PDCP-Config 정보를 포함한다.PDCP-Config: Contains PDCP-Config information received from the second base station.
■ RLC-Config: 제 2 기지국으로부터 수신한 RLC-Config 정보를 포함한다.■ RLC-Config: Contains RLC-Config information received from the second base station.
■ logicalChannelIdentity: 논리채널 식별자에 대한 정보를 포함한다.■ logicalChannelIdentity: Contains information about logical channel identifier.
■ logicalChannelConfig: 제 2 기지국으로부터 수신한 논리채널구성정보에 대한 정보를 포함한다.■ logicalChannelConfig: Contains information about logical channel configuration information received from the second base station.
또 다른 방법으로 제 1 기지국은 제 2 기지국과 사용자 플레인 데이터 전송 또는 DRBs 설정을 위한 베어러 설정 시그널링 절차를 개시한 후(예를 들어, 제 2 기지국으로 베어러 설정 요청 메시지를 송신한 후, S730) 상위계층 시그널링(예를 들어, RRC 연결 재구성 메시지)에 추가/수정할 DRBs 정보를 포함하여 단말로 전송한다(S740). Alternatively, the first base station may initiate a bearer establishment signaling procedure for transmitting user plane data or DRBs with the second base station (for example, after transmitting a bearer establishment request message to the second base station, S730). The DRBs information to be added / modified in the layer signaling (for example, an RRC connection reconfiguration message) is transmitted to the terminal (S740).
단말(703)은 수신된 상위계층 시그널링에 포함된 정보에 기초하여 제 2 기지국과 DRBs를 추가/수정하거나 또는 제 1 기지국의 DRBs를 제 2 기지국의 DRBs로 수정할 수 있다(S745).The terminal 703 may add / modify the second base station and the DRBs based on the information included in the received higher layer signaling, or may modify the DRBs of the first base station to the DRBs of the second base station (S745).
예를 들어, 전술한 추가/수정할 DRBs 정보는 다음 중 적어도 하나 이상의 정보를 포함할 수 있다.For example, the above-described DRBs information to be added / modified may include at least one or more of the following information.
■ EPS-Beareridentity: EPS 베어러 식별자로 E-RAB ID 정보를 포함할 수 있다.■ EPS-Beareridentity: EPS bearer identifier may include E-RAB ID information.
■ 제 2 기지국에 연관된 셀(스몰 셀) 식별자: 제 2 기지국에 연관된 셀의 PCI(Physical Cell ID), ARFCN(Absolute Radio Frequency Channel)에 대한 정보를 포함할 수 있다.■ Cell (small cell) identifier associated with the second base station: It may include information about the Physical Cell ID (PCI), the Absolute Radio Frequency Channel (ARFCN) of the cell associated with the second base station.
■ 제 2 기지국 셀(스몰 셀) 인덱스: 단말에 구성된 SCells 내에서 또는 단말에 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 SCell로 구성된 제 2 기지국 셀(스몰 셀)들 내에서 또는 단말에 대해 제 2 기지국 셀(스몰 셀)로 구성된 SCell 내에서, 각각의 제 2 기지국 셀(스몰 셀) 또는 SCell을 식별하기 위해 사용되는 인덱스 정보를 포함할 수 있다.■ Second base station cell (small cell) index: within the SCells configured in the terminal or in the second base station cells (small cells) configured in the terminal or in the second base station cells (small cells) configured with the SCell in the terminal or Within the SCell configured as the second base station cell (small cell) for the terminal, it may include index information used to identify each second base station cell (small cell) or SCell.
■ DRB-ID: 제 1 기지국이 결정하여 제 2 기지국으로 전달한 DRB-ID 정보를 포함할 수 있다.DRB-ID: The information may include DRB-ID information determined by the first base station and delivered to the second base station.
■ PDCP-Config: 제 1 기지국이 결정하여 제 2 기지국으로 전달한 PDCP-Config 정보를 포함한다.PDCP-Config: Contains PDCP-Config information determined by the first base station and delivered to the second base station.
■ RLC-Config: 제 1 기지국이 결정하여 제 2 기지국으로 전달한 RLC-Config 정보를 포함한다.■ RLC-Config: Includes RLC-Config information determined by the first base station and delivered to the second base station.
■ logicalChannelIdentity: 논리채널 식별자에 대한 정보를 포함한다.■ logicalChannelIdentity: Contains information about logical channel identifier.
■ logicalChannelConfig: 논리채널 구성정보에 대한 정보를 포함한다.■ logicalChannelConfig: Contains information about logical channel configuration information.
또한, 위와 같이 단말(703)로 전송되는 상위계층 시그널링에는 추가/수정할 DRB 정보 또는 해제할 DRB 정보와 함께 제 2 기지국(702)이 제공하는 스몰 셀과 제 1 기지국(701)이 제공하는 매크로 셀을 구별하기 위한 식별정보가 더 포함될 수도 있다. 또한, 제 2 기지국을 통해 구성되는 데이터 무선베어러 정보는, 단말이 MAC 계층에서 제 1 기지국과 제 2 기지국을 구별하기 위한 정보 및 제 1 기지국이 제공하는 셀과 제 2 기지국이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.In addition, in the upper layer signaling transmitted to the terminal 703 as described above, a small cell provided by the second base station 702 and a macro cell provided by the first base station 701 together with DRB information to be added / modified or DRB information to be released. Identification information for distinguishing may be further included. Further, the data radio bearer information configured through the second base station may include information for distinguishing the first base station and the second base station from the MAC layer by the terminal, and distinguishing a cell provided by the first base station and a cell provided by the second base station. It may include at least one or more of the information for.
예를 들어, 이전에 제 1 기지국(701)을 통해 구성된 DRBs를 제 2 기지국(702)을 통해 추가/수정하는 경우에 추가/수정할 DRB에 대한 정보가 제 2 기지국 스몰 셀 식별자를 포함할 수 있다. For example, when DRBs previously configured through the first base station 701 are added / modified through the second base station 702, the information on the DRB to be added / modified may include the second base station small cell identifier. .
또한, 해제할 DRB에 대한 정보(DRB-ToAddMod)는 매크로 셀에서 해제할 DRB 정보와 제 1 기지국 매크로 셀 식별자 정보가 함께 포함할 수도 있다.In addition, the information about the DRB to be released (DRB-ToAddMod) may include both the DRB information to be released in the macro cell and the first base station macro cell identifier information.
또 다른 방법으로는 전술한 추가/수정할 DRB에 전술한 제 2 기지국 셀(스몰 셀) 인덱스 또는 SCell 인덱스가 포함될 수도 있다.Alternatively, the above-described second base station cell (small cell) index or SCell index may be included in the aforementioned DRB to be added / modified.
이하에서는 본 발명의 일 실시예에 따른 제 1 기지국(701)이 상위계층 시그널링에 데이터 무선 베어러 정보를 포함하여 전송하는 경우, 포함되는 정보의 각 파라미터들을 결정하는 주체에 대해서 자세히 설명한다.Hereinafter, when the first base station 701 according to an embodiment of the present invention transmits data radio bearer information in higher layer signaling, the subject for determining each parameter of the included information will be described in detail.
본 발명의 일 실시예에 따른 상위계층 시그널링은, 제 2 기지국에 연관된 셀 구성을 위한 정보를 더 포함하되, 제 2 기지국에 연관된 셀 구성을 위한 정보는 제 2 기지국이 설정하여 제 1 기지국으로 전송한 정보일 수 있다. 즉, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보는, 제 2 기지국이 설정하여 제 1 기지국으로 전송한 정보일 수 있다.The higher layer signaling according to an embodiment of the present invention further includes information for cell configuration associated with the second base station, and information for cell configuration associated with the second base station is set by the second base station and transmitted to the first base station. It may be one piece of information. That is, the second base station cell index information and the data radio bearer information configured through the second base station may be information set by the second base station and transmitted to the first base station.
또는, 제 2 기지국에 연관된 셀 구성을 위한 정보는 측정 리포팅 정보, 제 1 기지국 데이터 부하 정보 및 베어러 설정 응답 메시지 중 적어도 하나 이상의 정보에 기초하여 제 1 기지국에 의해서 설정될 수도 있다.Alternatively, the information for cell configuration associated with the second base station may be set by the first base station based on at least one or more of measurement reporting information, first base station data load information, and bearer setup response message.
구체적으로 각 경우에 대한 예를 들어 설명한다.Specifically, an example of each case will be described.
1) 제 2 기지국이 결정하는 방법.1) Method determined by the second base station.
제 1 기지국(701)은 MME로부터 수신된 이니셜 컨텍스트 셋업 요청(Initial Context Setup Request) 메시지 내에 포함되는 정보(예를 들어, E-RABs list 등의 단말 컨텍스트 정보), 측정 리포팅 정보 및 데이터 부하 정보 중 적어도 하나 이상의 정보를 베어러 설정 요청 메시지에 포함하여 제 2 기지국(702)으로 전달할 수 있다. The first base station 701 may include information (for example, terminal context information such as E-RABs list), measurement reporting information, and data load information included in an initial context setup request message received from the MME. At least one information may be included in the bearer establishment request message and transmitted to the second base station 702.
제 2 기지국(702)는 전달된 상기 정보에 기초하여 전술한 상위계층 시그널링에 포함되는 파라미터를 결정할 수 있다. 즉, 제 2 기지국(702)는 전달된 상기 정보에 기초하여 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 또는 각 정보에 포함되는 파라미터를 결정할 수 있다.The second base station 702 may determine a parameter included in the above-described higher layer signaling based on the transmitted information. That is, the second base station 702 may determine the second base station cell index information and the data radio bearer information configured through the second base station or a parameter included in each information based on the transmitted information.
결정된 파라미터 정보들은 제 1 기지국으로 전송되어 상위계층 시그널링(예를 들어, RRC 연결 재구성 메시지) 을 통해 단말로 전송될 수 있다.The determined parameter information may be transmitted to the first base station and transmitted to the terminal through higher layer signaling (eg, an RRC connection reconfiguration message).
2) 제 1 기지국이 결정하는 방법.2) Method determined by the first base station.
제 1 기지국(701)은 MME로부터 수신된 이니셜 컨텍스트 셋업 요청(Initial Context Setup Request) 메시지 내의 정보(예를 들어, E-RABs list), 측정 리포팅 정보 및 데이터 부하 정보 중 적어도 하나 이상의 정보에 기초하여 결정할 수 있다. 즉, 상위계층 시그널링(예를 들어, RRC Connection Reconfiguration 메시지)에 포함되는 전술한 파라미터들(예를 들어, PDCP 구성정보, RLC 구성정보, MAC 구성정보 등)은 제 1 기지국(701)에 의해 결정될 수 있다.The first base station 701 is based on at least one of information (eg, E-RABs list), measurement reporting information, and data load information in the initial context setup request message received from the MME. You can decide. That is, the above-described parameters (eg, PDCP configuration information, RLC configuration information, MAC configuration information, etc.) included in higher layer signaling (eg, RRC Connection Reconfiguration message) may be determined by the first base station 701. Can be.
3) 제 1 기지국이 결정하는 다른 방법.3) Another method determined by the first base station.
제 1 기지국(701)은 MME로부터 수신된 이니셜 컨텍스트 셋업 요청(Initial Context Setup Request) 메시지 내의 정보(예를 들어, E-RABs list), 측정 리포팅 정보 및 데이터 부하 정보 중 적어도 하나 이상의 정보와 제 2 기지국(702)으로부터 수신된 베어러 설정 응답 메시지에 기초하여 결정할 수도 있다.The first base station 701 may include at least one of information (eg, E-RABs list), measurement reporting information, and data load information in the initial context setup request message received from the MME, and the second. The determination may be based on the bearer establishment response message received from the base station 702.
앞에서 설명한 바와 같이 단말은 제 1 기지국으로부터 전술한 제 2 기지국에 연관된 셀에 액세스를 위한 관련 정보를 수신하여 제 2 기지국과 업링크 동기화를 위한 랜덤 액세스 절차를 수행할 수도 있다.As described above, the UE may perform a random access procedure for uplink synchronization with the second base station by receiving the related information for accessing the cell associated with the second base station from the first base station.
제 1 기지국은 제 2 기지국과 사용자 플레인 데이터 전송을 위한 베어러 설정 시그널링 절차를 완료한 후(예를 들어, 베어러 설정 응답 메시지를 수신한 후), 상위계층 시그널링(예를 들어, RRC Connection Reconfiguration 메시지)을 통해 단말의 업링크 동기화를 위한 랜덤 액세스 관련 정보를 전송할 수 있다.After the first base station completes the bearer setup signaling procedure for user plane data transmission with the second base station (eg, after receiving a bearer setup response message), higher layer signaling (eg, an RRC Connection Reconfiguration message) Through the random access related information for uplink synchronization of the terminal can be transmitted.
제 1 기지국은 단말이 제 2 기지국에 연관된 셀(스몰 셀)에 업링크 동기화를 수행하고 제 2 기지국에 연관된 셀(스몰 셀)에 랜덤 액세스 채널(Random Access Chennel, RACH)을 통해 액세스할 수 있도록 하기 위한 제 2 기지국에 연관된 셀 식별정보, 제 2 기지국 셀 시스템 정보, 제 2 기지국 전용 MAC 계층 구성 정보 및 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 중 적어도 하나 이상의 정보를 더 포함하여 전송할 수 있다. The first base station enables the terminal to perform uplink synchronization with a cell (small cell) associated with the second base station and access a cell (small cell) associated with the second base station through a random access channel (Random Access Chennel, RACH). The mobile station may further include at least one of cell identification information, second base station cell system information, second base station dedicated MAC layer configuration information, and second base station cell random access channel preamble associated with the second base station.
위에서는 제 2 기지국에 연관된 셀에 액세스를 수행하기 위한 관련 정보가 상위계층 시그널링을 통해서 전송되는 것을 예를 들어 설명하였으나, 상위계층 시그널링 전송과 별도의 단계로 전송될 수도 있다.In the above description, for example, the related information for performing access to the cell associated with the second base station is transmitted through higher layer signaling, but may be transmitted in a step separate from the higher layer signaling transmission.
단말은 전술한 제 2 기지국에 연관된 셀(스몰 셀)의 무선자원 구성정보를 포함한 상위계층 시그널링(예를 들어, RRC 연결 재구성 메시지)를 수신한 후, 제 2 기지국에 연관된 셀과 동기화를 수행한다. 만약, 전용 랜덤 액세스 채널 프리앰블 정보가 포함되어 있다면 "contention-free" 프로시저를 따라서 랜덤 액세스 프로시저를 수행할 수 있다. 또는 전용 랜덤 액세스 채널 프리앰블이 포함되지 않았다면 "contention-based" 프로시져를 따라 랜덤 액세스 프로시저를 수행한다.The terminal receives higher layer signaling (eg, an RRC connection reconfiguration message) including radio resource configuration information of a cell (small cell) associated with the second base station, and then synchronizes with a cell associated with the second base station. . If the dedicated random access channel preamble information is included, the random access procedure may be performed according to the "contention-free" procedure. Or, if the dedicated random access channel preamble is not included, the random access procedure is performed according to the "contention-based" procedure.
예를 들어 경쟁 없는(contention-free) 프로시져를 따라 랜덤 액세스 프로시져를 수행하는 경우, 단말은 제 2 기지국에 연관된 셀에서 생성되어 제 1 기지국을 통해 수신된 RACH 프리앰블을 제 2 기지국 셀로 보내고 이에 대한 RACH response 메시지(RAR)를 제 2 기지국 셀로부터 수신함으로써 랜덤 액세스 절차를 수행할 수 있다.For example, when performing a random access procedure according to a contention-free procedure, the UE sends a RACH preamble generated in the cell associated with the second base station and received through the first base station to the second base station cell, and corresponding thereto. The random access procedure may be performed by receiving the response message RAR from the second base station cell.
전술한 상위계층 시그널링(예를 들어, RRC Connection Reconfiguration 메시지)은 하나의 메시지에 추가/수정할 제 2 기지국에 연관된 셀(스몰 셀) 정보, 추가/수정할 DRBs 정보, 업링크 동기화를 위한 랜덤 액세스 관련 정보를 함께 포함할 수도 있고, 개별적인 메시지에 전술한 하나 이상의 정보를 포함하여 각각 전송할 수도 있다. 예를 들어, 제 1 기지국(701)은 전술한 세컨더리 셀 추가수정 요청 메시지 송신(S720)과 세컨더리 셀 추가수정 응답 메시지 수신(S725)이후 단말에 제 2 기지국에 연관된 셀을 추가하기 위한 상위 계층 시그널링(S740)을 전송할 수 있다. 이후 전술한 베어러 설정 요청 메시지 송신(S730)과 베어러 설정 응답 메시지 수신(S735)를 수행하고 또 다른상위 계층 시그널링 전송을 수행하도록 할 수도 있다The above-described higher layer signaling (for example, RRC Connection Reconfiguration message) may include cell (small cell) information associated with a second base station to be added / modified in one message, DRBs information to be added / modified, and random access related information for uplink synchronization. May be included together, or each of the above-described information may be included in a separate message and transmitted. For example, the first base station 701 may transmit higher layer signaling to add a cell associated with the second base station to the terminal after the above-described secondary cell addition modification request message transmission (S720) and the secondary cell addition modification response message reception (S725). S740 may be transmitted. Thereafter, the aforementioned bearer establishment request message transmission (S730) and bearer establishment response message reception (S735) may be performed, and another upper layer signaling transmission may be performed.
단말(703)은 제 2 기지국(702)과 설정된 DRBs를 통해 사용자 플레인 데이터를 전송한다(S750)The terminal 703 transmits user plane data through the DRBs established with the second base station 702 (S750).
이상에서 살펴본 바와 같이 제 1 기지국이 단말의 사용자 플레인 데이터 전송을 제어하는 방법에 있어서 각 실시예를 구체적으로 살펴보았다.As described above, each embodiment has been described in detail in a method in which the first base station controls user plane data transmission of the terminal.
이하에서는, 도 8 및 도 9를 참조하여 사용자 플레인 데이터를 전송함에 있어서 제 1 기지국 및 단말의 동작을 살펴본다.Hereinafter, operations of the first base station and the terminal in transmitting user plane data will be described with reference to FIGS. 8 and 9.
도 8은 본 발명의 또 다른 실시예에 따른 기지국의 동작을 도시한 도면이다.8 is a diagram illustrating the operation of a base station according to another embodiment of the present invention.
본 발명의 일 실시예에 따른 제 1 기지국은 전술한 바와 같이 제 1 기지국 부하 정보 및 측정 리포트 정보 중 적어도 하나 이상의 정보에 기초하여 제 2 기지국을 통해 구성되는 무선 베어러를 선택하여 사용자 플레인 데이터 전송을 결정할 수 있다(S810).As described above, the first base station selects a radio bearer configured through the second base station based on at least one of the first base station load information and the measurement report information to perform user plane data transmission. It may be determined (S810).
이후, 제 1 기지국은 제 2 기지국을 통한 사용자 플레인 데이터 전송이 결정되면, 베어러 설정 요청 메시지를 제 2 기지국으로 전송한다(S820).Thereafter, when the user plane data transmission is determined through the second base station, the first base station transmits a bearer setup request message to the second base station (S820).
베어러 설정 요청 메시지는, 제 1 기지국 단말 X2AP(X2 application protocol) 식별자 정보, 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보, 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate) 및 E-RABs(E-UTRAN Radio Access Bearers) 셋업 리스트 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.The bearer setup request message may include: first base station terminal X2 application protocol (X2AP) identifier information, cell identifier information associated with the second base station, second base station cell index information, terminal aggregate maximum bit rate, and E- It may include at least one or more information from E-UTRAN Radio Access Bearers (RABs) setup list information.
제 1 기지국은 제 2 기지국으로부터 베어러 설정 응답 메시지를 수신한다(S830).The first base station receives a bearer setup response message from the second base station (S830).
베어러 설정 응답 메시지는, 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보, 제 2 기지국 셀 시스템 정보, 제 2 기지국 셀 전용 MAC 계층 구성 정보, E-RABs(E-UTRAN Radio Access Bearers) 수락 리스트 정보 및 수락된 E-RAB에 대한 제 2 기지국 데이터 무선베어러 구성정보 중 적어도 하나 이상의 정보를 포함할 수 있다.The bearer establishment response message includes cell identifier information associated with the second base station, second base station cell index information, second base station cell random access channel preamble information, second base station cell system information, second base station cell dedicated MAC layer configuration information, E At least one of E-UTRAN Radio Access Bearers (RABs) acceptance list information and second base station data radio bearer configuration information for the accepted E-RAB may be included.
제 1 기지국은 단말로 상위계층 시그널링을 전송할 수 있다(S840).The first base station may transmit higher layer signaling to the terminal (S840).
상위계층 시그널링은 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함할 수 있다. 또한, 상위계층 시그널링은 제 2 기지국 셀 시스템 정보, 제 2 기지국 전용 MAC 계층 구성 정보 및 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 중 적어도 하나 이상의 정보를 더 포함할 수 있다. 상위계층 시그널링에 포함되는 각각의 정보 파라미터(또는 세부정보)는 앞서 예를 들어 설명한 바와 같다.Higher layer signaling may include at least one of cell identifier information for a cell associated with a second base station, second base station cell index information, and data radio bearer information configured through the second base station. In addition, the higher layer signaling may further include at least one or more of second base station cell system information, second base station dedicated MAC layer configuration information, and second base station cell random access channel preamble. Each information parameter (or detailed information) included in higher layer signaling is as described above, for example.
한편, 제 2 기지국을 통해 구성되는 데이터 무선베어러 정보는, 단말이 MAC 계층에서 제 1 기지국과 상기 제 2 기지국을 구별하기 위한 정보 및 제 1 기지국이 제공하는 셀과 제 2 기지국이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.Meanwhile, the data radio bearer information configured through the second base station includes information for distinguishing the first base station and the second base station from the MAC layer, a cell provided by the first base station, and a cell provided by the second base station. It may include at least one or more information of the information for distinguishing.
본 발명의 다른 실시예에 따른 제 1 기지국은 단말로 제 2 기지국과의 업링크 동기화를 위한 랜덤 액세스에 필요한 정보를 전송할 수 있다. 이러한 정보는 전술한 상위계층 시그널링에 함께 포함될 수도 있고, 별개의 메시지 형태로 전송될 수도 있다.The first base station according to another embodiment of the present invention may transmit information necessary for random access for uplink synchronization with the second base station to the terminal. Such information may be included in the above-described higher layer signaling or transmitted in a separate message form.
제 2 실시예에서 살펴본 바와 같이 본 발명의 또 다른 실시예에 따른 제 1 기지국은 베어러 설정 요청 메시지 전송단계 이전에, 제 2 기지국으로 메시지 타입 정보, 제 2 기지국 식별자 정보, 제 2 기지국에 연관된 셀 식별자 정보 및 제 2 기지국 셀 인덱스 정보 중 적어도 하나 이상의 정보를 포함하는 세컨더리 셀 추가수정 요청 메시지를 전송하는 단계 및 제 2 기지국으로부터 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보 및 제 2 기지국 셀 무선자원구성정보 중 적어도 하나 이상의 정보를 포함하는 세컨더리 셀 추가수정 응답 메시지를 수신하는 단계를 더 포함할 수도 있다.As described in the second embodiment, the first base station according to another embodiment of the present invention transmits the message type information, the second base station identifier information, and the cell associated with the second base station to the second base station before the bearer setup request message transmission step. Transmitting a secondary cell addition modification request message including at least one of identifier information and second base station cell index information, and cell identifier information, second base station cell index information, and second associated with the second base station from the second base station; The method may further include receiving a secondary cell addition modification response message including at least one of base station cell random access channel preamble information and second base station cell radio resource configuration information.
도 9는 본 발명의 또 다른 실시예에 따른 단말의 동작을 도시한 도면이다.9 is a diagram illustrating an operation of a terminal according to another embodiment of the present invention.
본 발명의 또 다른 실시예에 따른 단말은 사용자 플레인 데이터를 전송을 제어하는 방법에 있어서, 제 1 기지국으로부터 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 수신하는 단계를 포함할 수 있다(S910). 또한, 수신된 상위계층 시그널링에 기초하여 제 2 기지국에 연관된 셀을 추가 또는 수정하고, 사용자 플레인 데이터 전송을 위한 데이터 무선 베어러를 구성하는 단계를 포함할 수 있다(S920). 이후, 단말은 구성된 데이터 무선 베어러를 이용하여 사용자 플레인 데이터를 전송할 수 있다(S930).In a method for controlling transmission of user plane data, a terminal according to another embodiment of the present invention includes cell identifier information, second base station cell index information, and a second base station for a cell associated with a second base station from a first base station. The method may include receiving higher layer signaling including at least one or more information among data radio bearer information configured through S910. In addition, the method may include adding or modifying a cell associated with the second base station based on the received higher layer signaling and configuring a data radio bearer for user plane data transmission (S920). Thereafter, the terminal may transmit user plane data using the configured data radio bearer (S930).
단말은 사용자 플레인 데이터 전송을 위한 데이터 무선 베어러를 구성함에 있어서, MAC 계층에서 제 1 기지국을 위한 MAC 개체 및 제 2 기지국을 위한 MAC 개체를 구분하여 구성할 수 있다. 또한, 제 2 기지국을 위한 MAC 개체는, 제 2 기지국을 통해 구성되는 무선 베어러를 위한 스케줄링 우선순위 처리 개체 및 멀티플렉싱 개체를 구분하여 구성될 수 있다.In configuring a data radio bearer for user plane data transmission, the terminal may separately configure a MAC entity for the first base station and a MAC entity for the second base station in the MAC layer. The MAC entity for the second base station may be configured by dividing the scheduling priority processing entity and the multiplexing entity for the radio bearer configured through the second base station.
제 2 기지국을 통해 구성되는 데이터 무선베어러 정보는, 단말이 MAC 계층에서 제 1 기지국과 상기 제 2 기지국을 구별하기 위한 정보 및 제 1 기지국이 제공하는 셀과 제 2 기지국이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.The data radio bearer information configured through the second base station may include information for distinguishing the first base station and the second base station from the MAC layer, and distinguishing a cell provided by the first base station and a cell provided by the second base station. Information may include at least one or more information.
또한, 본 발명의 다른 실시예에 따른 단말은 단말이 제 2 기지국에 연관된 셀에 액세스하기 위한 제 2 기지국에 연관된 셀 식별정보, 제 2 기지국 셀 시스템 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보 및 제 2 기지국 전용 MAC 계층 구성 정보를 포함하는 단말 특이적 구성정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 수신하여 제 2 기지국에 연관된 셀과 업링크 동기화를 위한 랜덤 액세스 절차를 수행할 수도 있다.In addition, according to another embodiment of the present invention, the terminal may include cell identification information, second base station cell system information, second base station cell random access channel preamble information, and the like associated with a second base station for a terminal to access a cell associated with a second base station. The UE may perform upper layer signaling including at least one of terminal specific configuration information including MAC layer configuration information of the second base station and perform a random access procedure for uplink synchronization with a cell associated with the second base station. .
이 경우, 제 2 기지국에 연관된 셀에 액세스하기 위한 정보는 스몰 셀 추가/수정 또는 DRB 추가/수정을 위한 정보와 함께 수신될 수도 있다.In this case, the information for accessing the cell associated with the second base station may be received together with the information for small cell addition / modification or DRB addition / modification.
이하에서는, 본 발명에 따른 사용자 플레인 데이터 전송 프로토콜의 구조 및 기지국 또는 단말의 계층 구조를 살펴본다.Hereinafter, the structure of the user plane data transmission protocol according to the present invention and the hierarchical structure of a base station or a terminal will be described.
도 10은 본 발명에 따른 제 2 기지국 인터페이스를 통한 사용자 플레인 데이터 전송 프로토콜의 구조를 일 예를 들어 도시한 도면이다.10 is a diagram illustrating an example of a structure of a user plane data transmission protocol through a second base station interface according to the present invention.
위에서 살펴본 본 발명의 사용자 플레인 데이터 전송 방법은 도 10과 같은 사용자 플레인 데이터 전송을 위한 프로토콜 구조에서 적용될 수 있다.The user plane data transmission method of the present invention described above may be applied in the protocol structure for user plane data transmission as shown in FIG.
도 11은 본 발명에 따른 제 2 기지국 인터페이스를 통한 사용자 플레인 데이터 전송 프로토콜의 구조를 다른 예를 들어 도시한 도면이다.11 is a diagram illustrating another example of a structure of a user plane data transmission protocol through a second base station interface according to the present invention.
위에서 살펴본 본 발명의 사용자 플레인 데이터 전송 방법은 도 11과 같은 사용자 플레인 데이터 전송을 위한 프로토콜 구조에서도 적용될 수 있다. The user plane data transmission method of the present invention described above may also be applied to the protocol structure for user plane data transmission as shown in FIG.
도 11의 프로토콜 구조는 도 2와 같이 제 1 기지국이 사용자 플레인 데이터를 제 2 기지국으로 포워딩하여 제 2 기지국이 이를 단말에게 전송하는 경우에 적용될 수 있다. The protocol structure of FIG. 11 may be applied to a case where the first base station forwards user plane data to the second base station and transmits it to the terminal as shown in FIG. 2.
도 12는 본 발명에 따른 제 1 기지국과 제 2 기지국의 Layer2 구조를 일 예를 들어 도시한 도면이다.12 is a diagram illustrating an example of a Layer2 structure of a first base station and a second base station according to the present invention.
도 12는 도 11의 프로토콜 구조를 사용할 경우에 제 1 기지국과 제 2 기지국의 Layer2 프로토콜 구조를 상세히 표시한 것이다.12 illustrates the Layer 2 protocol structure of the first base station and the second base station in detail when the protocol structure of FIG. 11 is used.
도 12를 참조하면, 제 1 기지국은 PDCP 계층에서 무선 베어러(Radio Bearer) 단위로 제 1 기지국으로 사용자 데이터를 전달할 PDCP 개체와 제 2 기지국으로 전달할 PDCP 개체(또는 제 1 기지국과 제 2 기지국으로 전달할 PDCP 개체)를 구분할 수 있다. 따라서 PDCP 계층은 제 2 기지국으로 전달할 PDCP PDU(Protocol Data Unit)를 스위칭(또는 라우팅)할 수 있는 기능을 갖을 수 있다.Referring to FIG. 12, a first base station transmits a PDCP entity to deliver user data to a first base station in units of a radio bearer in a PDCP layer, and a PDCP entity to transmit to a second base station (or to a first base station and a second base station). PDCP entity). Accordingly, the PDCP layer may have a function of switching (or routing) a PDCP protocol data unit (PDU) to be delivered to a second base station.
제 2 기지국은 제 2 기지국에 연관된 셀을 처리하기 위한 하나의 HARQ(Hybrid automatic repeat request) 개체를 가진다. 제 1 기지국은 제 1 기지국이 기존의 캐리어 병합기술을 지원하는 경우 복수의 HARQ개체를 가질 수 있다. 제 2 기지국도 제 2 기지국이 기존의 캐리어 병합기술을 지원하는 경우 복수의 HARQ개체를 가질 수 있다.The second base station has one Hybrid automatic repeat request (HARQ) entity for processing a cell associated with the second base station. The first base station may have a plurality of HARQ objects when the first base station supports the existing carrier aggregation technology. The second base station may also have a plurality of HARQ objects when the second base station supports the existing carrier aggregation technology.
도 11과 같은 프로토콜 구조에서 전술한 방법을 적용하는 경우, 제 2 기지국을 통한 사용자 플레인 데이터 전송을 위한 베어러 설정 요청 메시지에 AS Security Information 또는 AS Security Key 정보를 포함할 필요가 없으며, 베어러 설정 응답 메시지는 PDCP-CONFIG 정보를 포함할 필요가 없다.When the above-described method is applied to the protocol structure as shown in FIG. 11, it is not necessary to include AS Security Information or AS Security Key information in the bearer setup request message for transmitting user plane data through the second base station, and the bearer setup response message. Does not need to contain PDCP-CONFIG information.
도 13은 본 발명에 따른 제 1 기지국과 제 2 기지국의 Layer2 구조를 다른 예를 들어 도시한 도면이다.13 is a diagram illustrating another example of a Layer2 structure of a first base station and a second base station according to the present invention.
도 13은 도 3의 사용자 데이터 전송모델을 사용할 경우 제 1 기지국과 제 2 기지국의 Layer2 프로토콜 구조를 상세히 표시한 것이다.FIG. 13 shows the Layer2 protocol structure of the first base station and the second base station in detail when using the user data transmission model of FIG. 3.
도 13을 참조하면, 무선 베어러(Radio Bearer) 단위로 제 1 기지국을 통해 전달할 제 1 기지국의 PDCP 개체와 제 2 기지국을 통해 전달할 제 2 기지국의 PDCP 개체가 본 발명에서 전술한 절차들에 따라 미리 구분되어 있다.Referring to FIG. 13, the PDCP entity of the first base station to be transmitted through the first base station in units of radio bearers and the PDCP entity of the second base station to be transmitted through the second base station are previously described in accordance with the above-described procedures. Are separated.
제 2 기지국은 제 2 기지국에 연관된 셀을 처리하기 위한 하나의 HARQ(Hybrid automatic repeat request) 개체를 가진다. 제 1 기지국은 제 1 기지국이 기존의 캐리어 병합기술을 지원하는 경우 복수의 HARQ개체를 가질 수도 있다. 제 2 기지국도 제 2 기지국이 기존의 캐리어 병합기술을 지원하는 경우 복수의 HARQ개체를 가질 수 있다The second base station has one Hybrid automatic repeat request (HARQ) entity for processing a cell associated with the second base station. The first base station may have a plurality of HARQ objects when the first base station supports the existing carrier aggregation technology. The second base station may also have a plurality of HARQ objects when the second base station supports the existing carrier aggregation technology.
도 14는 본 발명에 따른 단말의 Layer2 구조를 일 예를 들어 도시한 도면이다.14 is a diagram illustrating an example of a Layer2 structure of a terminal according to the present invention.
도 14는 단말의 Layer2 프로토콜 구조를 상세히 표시한 것이다.14 shows the Layer2 protocol structure of the UE in detail.
도 14를 참조하면, 무선 베어러(Radio Bearer) 단위로 제 1 기지국을 통해 전달할 제 1 기지국의 PDCP 개체와 제 2 기지국을 통해 전달할 제 2 기지국의 PDCP 개체가 구분되어 있다. Referring to FIG. 14, a PDCP entity of a first base station to be transmitted through a first base station in units of radio bearers and a PDCP entity of a second base station to be transmitted through a second base station are distinguished.
단말이 하나 또는 하나 이상의 SCells 또는 서빙 셀로 구성될 때, SCells 또는 서빙 셀에 제 2 기지국에 연관된 셀(스몰 셀)을 포함하고 있다면, MAC 계층은 제 2 기지국을 통해 전달될 무선 베어러에 속하는 논리 채널들(logical channels)을 제 2 기지국을 통한 트랜스포트 채널들(예를 들어, DL-SCHs(Down link Shared Channels) 또는 UL-SCHs(Uplink Shared Channels))로 매핑할 수 있어야 한다. 이를 위해 전술한 논리채널구성정보(logicalchannelconfig)에 제 2 기지국에 연관된 셀(스몰 셀)들 또는 제 2 기지국을 통한 무선베어러임을 구분할 수 있는 정보를 포함할 수 있다. 예를 들어, 제 2 기지국에 연관된 셀을 구분할 수 있는 정보는 logicalchannelgroup 또는 priority 또는 제 2 기지국에 연관된 셀 식별자 정보 또는 제 2 기지국 셀 인덱스 정보 또는 새롭게 정의되는 정보(제 2 기지국 무선베어러 표시정보)일 수 있다. 다른 예로, 제 2 기지국에 연관된 셀(스몰 셀)에 대해 논리채널ID(logicalChannelId)를 구분하거나, 이를 기반으로 매핑 테이블을 두어 스위칭하는 등의 방법을 사용할 수 있다. When a terminal is composed of one or more SCells or serving cells, if the SCells or serving cells include a cell (small cell) associated with the second base station, the MAC layer is a logical channel belonging to the radio bearer to be delivered through the second base station. Logical channels may be mapped to transport channels (eg, downlink shared channels (DL-SCHs) or uplink shared channels (UL-SCHs)) through a second base station. To this end, the above-described logical channel configuration information may include information for distinguishing cells (small cells) associated with the second base station or radio bearer through the second base station. For example, the information for identifying a cell associated with a second base station may be a logical channel group or priority or cell identifier information associated with a second base station, second base station cell index information, or newly defined information (second base station radio bearer indication information). Can be. As another example, a logical channel ID may be distinguished for a cell (small cell) associated with a second base station, or a mapping table may be switched based on this.
도 15는 본 발명에 따른 단말의 Layer2 구조를 다른 예를 들어 도시한 도면이다.15 illustrates another example of a Layer2 structure of a terminal according to the present invention.
도 15는 도 14와는 다른 방법으로 구현된 단말의 Layer2 프로토콜 구조를 상세히 표시한 것이다.FIG. 15 illustrates in detail the Layer2 protocol structure of a terminal implemented in a method different from that of FIG. 14.
도 15를 참조하면, MAC 계층에서 제 1 기지국을 위한 MAC 계층(개체)과 제 2 기지국을 위한 MAC 계층(개체)이 분리되었다.Referring to FIG. 15, the MAC layer (object) for the first base station and the MAC layer (object) for the second base station are separated from the MAC layer.
즉, 제 1 기지국을 위한 스케줄링/우선권 제어(Scheduling/Priority Handling) 개체, 멀티플렉싱(Multiplexing) 개체, HARQ 개체 및 제 2 기지국을 위한 전술한 개체들을 각각 가질 수 있다. 따라서 단말이 하나 또는 하나 이상의 SCells 또는 서빙 셀로 구성될 때, SCells 또는 서빙 셀에 제 2 기지국에 연관된 셀(스몰 셀)을 포함하고 있다면, 제 2 기지국 MAC 개체는 제 2 기지국을 통해 전달될 무선 베어러에 속하는 논리 채널들(logical channels)을 제 2 기지국을 통한 트랜스포트 채널들(예를 들어, DL-SCHs(Down link Shared Channels) 또는 UL-SCHs(Uplink Shared Channels)로 매핑할 수 있다. 이를 위해 전술한 논리채널구성정보(logicalchannelconfig)에 제 2 기지국에 연관된 셀(스몰 셀) 또는 제 2 기지국을 통한 무선베어러임을 구분하기 위한 정보를 포함할 수 있다. 예를 들어, 제 2 기지국에 연관된 셀을 구분할 수 있는 정보는 logicalchannelgroup 또는 priority 또는 제 2 기지국에 연관된 셀 식별자 정보 또는 제 2 기지국 셀 인덱스 정보 또는 새롭게 정의되는 정보(제 2 기지국 무선베어러 표시정보)일 수 있다. That is, the scheduling / priority handling entity for the first base station, multiplexing entity, multiplexing entity, HARQ entity, and the aforementioned entities for the second base station may be respectively present. Therefore, when the terminal is configured with one or more SCells or serving cells, if the SCells or serving cells include a cell (small cell) associated with the second base station, the second base station MAC entity is a radio bearer to be delivered through the second base station. Logical channels belonging to may be mapped to transport channels (eg, downlink shared channels (DL-SCHs) or uplink shared channels (UL-SCHs) through a second base station. The above-described logical channel configuration information may include information for identifying a cell (small cell) associated with the second base station or a radio bearer through the second base station. The distinguishable information may include logicalchannel group or priority or cell identifier information associated with the second base station or second base station cell index information or newly defined information (second base station radio Bearer display information) can be.
전술한 도 10과 도 11에서 UDP 프로토콜은 SCTP(Stream Control Transmission Protocol) 프로토콜로 바꾸어 사용할 수도 있다. 10 and 11, the UDP protocol may be replaced with a SCTP protocol.
도 16은 본 발명에 따른 단말의 Layer2 구조를 또 다른 예를 들어 도시한 도면이다.16 illustrates another example of a Layer2 structure of a terminal according to the present invention.
도 16은 도 14 및 도 15와는 다른 방법으로 구현된 단말의 Layer2 프로토콜 구조를 상세히 표시한 것이다.FIG. 16 illustrates in detail the Layer2 protocol structure of a terminal implemented in a method different from those of FIGS. 14 and 15.
도 16을 참조하면, 하나의 무선 베어러에 대해 제 1 기지국과 제 2 기지국을 통해 사용자 플레인 데이터를 전송하도록 하기 위해 MAC 계층에서 제 1 기지국을 위한 MAC 계층(개체)과 제 2 기지국을 위한 MAC 계층(개체)이 분리되어 이중으로 제공된다. 또한, RLC 계층에서 제 1 기지국을 위한 RLC 계층(개체)과 제 2 기지국을 위한 RLC 계층(개체)이 분리되어 이중으로 제공된다Referring to FIG. 16, the MAC layer (object) for the first base station and the MAC layer for the second base station in the MAC layer to transmit user plane data through the first base station and the second base station for one radio bearer. (Individual) are separated and provided in duplicate. In addition, in the RLC layer, an RLC layer (object) for the first base station and an RLC layer (object) for the second base station are separated and provided in duplicate.
즉, 제 1 기지국을 위한 스케줄링/우선권 제어(Scheduling/Priority Handling) 개체, 멀티플렉싱(Multiplexing) 개체, HARQ 개체, RLC 개체 및 제 2 기지국을 위한 전술한 개체들을 각각 가질 수 있다.That is, it may have a scheduling / priority handling entity for the first base station, a multiplexing entity, a HARQ entity, an RLC entity, and the aforementioned entities for the second base station, respectively.
PDCP 계층에서는 제 1 기지국 RLC 계층과 제 2 기지국 RLC계층으로 데이터를 분리하여 스위칭하기 위한 개체를 가질 수 있다.The PDCP layer may have an entity for separating and switching data into a first base station RLC layer and a second base station RLC layer.
이상에서 살펴본 본 발명이 전부 수행될 수 있는 기지국 및 단말의 구성에 대해서 도 17 및 도 18을 참조하여 살펴본다.The configuration of the base station and the terminal in which the present invention described above can be performed will be described with reference to FIGS. 17 and 18.
도 4 내지 도 9를 참조하여 설명한 본 발명의 방법은 아래에서 설명할 기지국 및 단말에 의해서 모두 구현될 수 있다.The method of the present invention described with reference to FIGS. 4 to 9 may be implemented by both the base station and the terminal to be described below.
도 17은 본 발명의 또 다른 실시예에 따른 기지국의 구성을 도시한 도면이다.17 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
도 17을 참조하면, 본 발명의 또 다른 실시예에 의한 기지국(1700)은 제어부(1710), 송신부(1720) 및 수신부(1730)를 포함한다.Referring to FIG. 17, a base station 1700 according to another embodiment of the present invention includes a controller 1710, a transmitter 1720, and a receiver 1730.
제어부(1710)는 전술한 본 발명을 수행하기에 필요한 제 1 기지국의 제어 하에 제 2 기지국을 통한 사용자 플레인 데이터 전송 방법을 제어하는 데에 따른 전반적인 기지국의 동작을 제어한다.The controller 1710 controls the overall operation of the base station according to controlling the user plane data transmission method through the second base station under the control of the first base station required to perform the above-described present invention.
송신부(1720)와 수신부(1730)는 전술한 본 발명을 수행하기에 필요한 신호나 메시지, 데이터를 단말과 송수신하는데 사용된다.The transmitter 1720 and the receiver 1730 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention.
구체적으로, 제어부(1710)는 측정 리포팅 정보 및 제 1 기지국의 데이터 부하 정보 중 적어도 하나 이상의 정보에 기초하여 제 2 기지국을 통해서 구성되는 무선 베어러를 선택하여 사용자 플레인 데이터 전송을 결정할 수 있다.In detail, the controller 1710 may determine a user plane data transmission by selecting a radio bearer configured through the second base station based on at least one of measurement reporting information and data load information of the first base station.
송신부(1720)는 사용자 플레인 데이터 전송이 결정되면, 제 2 기지국으로 베어러 설정 요청 메시지를 전송할 수 있다. When the user plane data transmission is determined, the transmitter 1720 may transmit a bearer setup request message to the second base station.
베어러 설정 요청 메시지는, 제 1 기지국 단말 X2AP(X2 application protocol) 식별자 정보, 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보, 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate) 및 E-RABs(E-UTRAN Radio Access Bearers) 셋업 리스트 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.The bearer setup request message may include: first base station terminal X2 application protocol (X2AP) identifier information, cell identifier information associated with the second base station, second base station cell index information, terminal aggregate maximum bit rate, and E- It may include at least one or more information from E-UTRAN Radio Access Bearers (RABs) setup list information.
또한, 송신부(1720)는 본 발명의 다른 실시예에 따른 제 2 기지국으로 메시지 타입 정보, 제 2 기지국 식별자 정보, 제 2 기지국에 연관된 셀 식별자 정보 및 제 2 기지국 셀 인덱스 정보 중 적어도 하나 이상의 정보를 포함하는 세컨더리 셀 추가수정 요청 메시지를 전송할 수도 있다.In addition, the transmitter 1720 transmits at least one of message type information, second base station identifier information, cell identifier information associated with the second base station, and second base station cell index information to the second base station according to another embodiment of the present invention. The secondary cell addition modification request message may be transmitted.
또한, 송신부(1720)는 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 단말로 전송할 수 있다. 또한, 상위계층 시그널링은 제 2 기지국 셀 시스템 정보, 제 2 기지국 전용 MAC 계층 구성 정보 및 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 중 적어도 하나 이상의 정보를 더 포함할 수도 있다.In addition, the transmitter 1720 is a terminal for higher layer signaling including at least one or more of the cell identifier information for the cell associated with the second base station, the second base station cell index information and the data radio bearer information configured through the second base station Can be sent to. In addition, the higher layer signaling may further include at least one or more information of the second base station cell system information, the second base station dedicated MAC layer configuration information, and the second base station cell random access channel preamble.
전술한 제 2 기지국을 통해 구성되는 데이터 무선베어러 정보는, 단말이 MAC 계층에서 제 1 기지국과 제 2 기지국을 구별하기 위한 정보 및 제 1 기지국이 제공하는 셀과 제 2 기지국이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.The data radio bearer information configured through the above-described second base station may include information for distinguishing a first base station and a second base station from a MAC layer by a terminal, and a cell provided by a first base station and a cell provided by a second base station. It may include at least one or more of the information for.
수신부(1730)는 제 2 기지국으로부터 베어러 설정 응답 메시지를 수신할 수 있다.The receiver 1730 may receive a bearer setup response message from the second base station.
베어러 설정 응답 메시지는, 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보, 제 2 기지국 셀 시스템 정보, 제 2 기지국 셀 전용 MAC 계층 구성 정보, E-RABs(E-UTRAN Radio Access Bearers) 수락 리스트 정보 및 수락된 E-RAB에 대한 제 2 기지국 데이터 무선베어러 구성정보 중 적어도 하나 이상의 정보를 포함할 수 있다.The bearer establishment response message includes cell identifier information associated with the second base station, second base station cell index information, second base station cell random access channel preamble information, second base station cell system information, second base station cell dedicated MAC layer configuration information, E At least one of E-UTRAN Radio Access Bearers (RABs) acceptance list information and second base station data radio bearer configuration information for the accepted E-RAB may be included.
또한, 수신부(1730)는 제 2 기지국으로부터 제 2 기지국에 연관된 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보 및 제 2 기지국 셀 무선자원구성정보 중 적어도 하나 이상의 정보를 포함하는 세컨더리 셀 추가수정 응답 메시지를 수신할 수도 있다.In addition, the receiving unit 1730 may include at least one of cell identifier information, second base station cell index information, second base station cell random access channel preamble information, and second base station cell radio resource configuration information associated with the second base station from the second base station. A secondary cell addition modification response message including a may be received.
도 18은 본 발명의 또 다른 실시예에 다른 단말의 구성을 도시한 도면이다.18 is a diagram showing the configuration of another terminal according to another embodiment of the present invention.
도 18을 참조하면, 본 발명의 또 다른 실시예에 의한 사용자 단말(1800)은 수신부(1810), 제어부(1820) 및 송신부(1830)를 포함한다.Referring to FIG. 18, a user terminal 1800 according to another embodiment of the present invention includes a receiver 1810, a controller 1820, and a transmitter 1830.
제어부(1820)는 전술한 본 발명을 수행하기에 필요한 제 1 기지국의 제어 하에 제 2 기지국을 통한 사용자 플레인 데이터를 전송하는 데에 따른 전반적인 단말의 동작을 제어한다. The controller 1820 controls the overall operation of the terminal according to the transmission of the user plane data through the second base station under the control of the first base station required to carry out the present invention described above.
수신부(1810)는 제 1 또는 제 2 기지국으로부터 하향링크 제어정보 및 데이터, 메시지를 해당 채널을 통해 수신한다.The receiver 1810 receives downlink control information, data, and a message from a first or second base station through a corresponding channel.
송신부(1830)는 제 1 또는 제 2 기지국에 하향링크 제어정보 및 데이터, 메시지를 해당 채널을 통해 전송한다.The transmitter 1830 transmits downlink control information, data, and messages to the first or second base station through the corresponding channel.
구체적으로, 제어부(1820)는 제 1 기지국으로부터 수신된 상위계층 시그널링에 기초하여 제 2 기지국에 연관된 셀을 추가 또는 수정하고, 사용자 플레인 데이터 전송을 위한 데이터 무선 베어러를 구성하도록 제어할 수 있다.In detail, the controller 1820 may control to add or modify a cell associated with the second base station based on higher layer signaling received from the first base station, and configure a data radio bearer for user plane data transmission.
또한, 제어부(1820)는 제 2 기지국에 연관된 셀과의 업링크 동기화를 위한 랜덤 액세스 절차를 진행하는 데에 관련된 전반적인 단말의 동작을 제어할 수 있다.In addition, the controller 1820 may control the overall operation of the terminal related to the random access procedure for uplink synchronization with the cell associated with the second base station.
또한, 제어부(1820)는, MAC 계층에서 제 1 기지국을 위한 MAC 개체 및 제 2 기지국을 위한 MAC 개체를 구분하여 구성하도록 제어할 수 있다. 제 2 기지국을 위한 MAC 개체는, 제 2 기지국을 통해 구성되는 무선 베어러를 위한 스케줄링 우선순위 처리 개체 및 멀티플렉싱 개체를 구분하여 구성될 수 있다.In addition, the controller 1820 may control to separately configure the MAC entity for the first base station and the MAC entity for the second base station in the MAC layer. The MAC entity for the second base station may be configured by dividing the scheduling priority processing entity and the multiplexing entity for the radio bearer configured through the second base station.
수신부(1810)는 제 1 기지국으로부터 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 수신할 수 있다.The receiver 1810 may perform higher layer signaling including at least one of cell identifier information, second base station cell index information, and data radio bearer information configured through the second base station for the cell associated with the second base station from the first base station. Can be received.
또한, 수신부(1810)는 단말이 제 2 기지국에 연관된 셀에 액세스하기 위한 제 2 기지국에 연관된 셀 식별정보, 제 2 기지국 셀 시스템 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보 및 단말 특이적 구성정보 중 적어도 하나 이상의 정보를 더 포함하는 상위계층 시그널링을 수신할 수도 있다.In addition, the receiver 1810 may include a cell identification information, a second base station cell system information, a second base station cell random access channel preamble information, and a terminal specific configuration information associated with a second base station for a terminal to access a cell associated with a second base station. A higher layer signaling further including at least one of the information may be received.
전술한 제 2 기지국을 통해 구성되는 데이터 무선베어러 정보는, 단말이 MAC 계층에서 제 1 기지국과 제 2 기지국을 구별하기 위한 정보 및 제 1 기지국이 제공하는 셀과 제 2 기지국이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함할 수 있다.The data radio bearer information configured through the above-described second base station may include information for distinguishing a first base station and a second base station from a MAC layer by a terminal, and a cell provided by a first base station and a cell provided by a second base station. It may include at least one or more of the information for.
송신부(1830)는 제 2 기지국으로 데이터 무선 베어러를 통해서 사용자 플레인 데이터를 전송할 수 있다.The transmitter 1830 may transmit user plane data to the second base station through the data radio bearer.
이상에서 살펴본 바와 같이, 본 발명을 적용할 경우, 단말이 제 2 기지국을 통해서 사용자 플레인 데이터를 전송하기 위해서 제 2 기지국에 연관된 셀 또는 데이터 무선 베어러를 추가/수정하는 방법 및 장치를 제공하는 효과가 있다.As described above, in the case of applying the present invention, there is an effect of providing a method and apparatus for adding / modifying a cell or data radio bearer associated with a second base station to transmit user plane data through the second base station. have.
또한, 본 발명을 적용할 경우, 제 1 기지국이 단말의 제 2 기지국에 연관된 셀(스몰 셀) 추가/수정 또는 제 2 기지국에 연관된 셀(스몰 셀)에 구성될 무선 베어러 추가/수정 등의 절차를 제어하는 방법 및 장치를 제공하는 효과가 있다.In addition, when the present invention is applied, a procedure such as adding / modifying a cell (small cell) associated with a second base station of a terminal or adding / modifying a radio bearer to be configured in a cell (small cell) associated with a second base station It is effective to provide a method and apparatus for controlling the same.
이상의 설명은 본 발명의 기술 사상을 예시적으로 설명한 것에 불과한 것으로서, 본 발명이 속하는 기술 분야에서 통상의 지식을 가진 자라면 본 발명의 본질적인 특성에서 벗어나지 않는 범위에서 다양한 수정 및 변형이 가능할 것이다. 따라서, 본 발명에 개시된 실시예들은 본 발명의 기술 사상을 한정하기 위한 것이 아니라 설명하기 위한 것이고, 이러한 실시예에 의하여 본 발명의 기술 사상의 범위가 한정되는 것은 아니다. 본 발명의 보호 범위는 아래의 청구범위에 의하여 해석되어야 하며, 그와 동등한 범위 내에 있는 모든 기술 사상은 본 발명의 권리범위에 포함되는 것으로 해석되어야 할 것이다.The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.
CROSS-REFERENCE TO RELATED APPLICATIONCROSS-REFERENCE TO RELATED APPLICATION
본 특허출원은 2013년 02월 01일 한국에 출원한 특허출원번호 제 10-2013-0011913 호 및 2013년 02월 13일 한국에 출원한 특허출원번호 제 10-2013-0015296 호 및 2013년 10월 29일 한국에 출원한 특허출원번호 제 10-2013-0129015 호에 대해 미국 특허법 119(a)조 (35 U.S.C § 119(a))에 따라 우선권을 주장하며, 그 모든 내용은 참고문헌으로 본 특허출원에 병합된다. 아울러, 본 특허출원은 미국 이외에 국가에 대해서도 위와 동일한 이유로 우선권을 주장하면 그 모든 내용은 참고문헌으로 본 특허출원에 병합된다.This patent application is filed with a patent application No. 10-2013-0011913 filed in Korea on Feb. 01, 2013 and a patent application No. 10-2013-0015296 filed in Korea on Feb. 13, 2013 and in October 2013. Priority is claimed under Patent Application No. 10-2013-0129015 filed in Korea on the 29th in accordance with US Patent Act Article 119 (a) (35 USC § 119 (a)), all of which are incorporated by reference. Incorporated into the application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims (20)

  1. 제 1 기지국이 단말의 사용자 플레인 데이터 전송을 제어하는 방법에 있어서,In the first base station to control the user plane data transmission of the terminal,
    상기 제 1 기지국의 부하 정보 및 측정 리포트 정보 중 적어도 하나 이상의 정보에 기초하여 제 2 기지국을 통해 구성되는 무선 베어러를 선택하여 상기 사용자 플레인 데이터 전송을 결정하는 단계;Determining a user plane data transmission by selecting a radio bearer configured through a second base station based on at least one of load information and measurement report information of the first base station;
    상기 제 2 기지국으로 베어러 설정 요청 메시지를 전송하는 단계;Transmitting a bearer establishment request message to the second base station;
    상기 제 2 기지국으로부터 베어러 설정 응답 메시지를 수신하는 단계; 및Receiving a bearer establishment response message from the second base station; And
    상기 단말로 상기 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 상기 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 전송하는 단계를 포함하는 방법.Transmitting, to the terminal, higher layer signaling including at least one of cell identifier information for a cell associated with the second base station, second base station cell index information, and data radio bearer information configured through the second base station; How to include.
  2. 제 1항에 있어서,The method of claim 1,
    상기 베어러 설정 요청 메시지는,The bearer setup request message,
    제 1 기지국 단말 X2AP(X2 application protocol) 식별자 정보, 상기 제 2 기지국에 연관된 셀 식별자 정보, 상기 제 2 기지국 셀 인덱스 정보, 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate) 및 E-RABs(E-UTRAN Radio Access Bearers) 셋업 리스트 정보 중 적어도 하나 이상의 정보를 포함하는 방법.First base station terminal X2 application protocol (X2AP) identifier information, cell identifier information associated with the second base station, the second base station cell index information, UE total maximum bit rate and E-RABs (E-RAB) UTRAN Radio Access Bearers) and at least one of the setup list information.
  3. 제 1항에 있어서,The method of claim 1,
    상기 베어러 설정 응답 메시지는,The bearer setup response message,
    상기 제 2 기지국에 연관된 셀 식별자 정보, 상기 제 2 기지국 셀 인덱스 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보, 제 2 기지국 셀 시스템 정보, 제 2 기지국 셀 전용 MAC 계층 구성 정보, E-RABs(E-UTRAN Radio Access Bearers) 수락 리스트 정보 및 상기 수락된 E-RAB에 대한 제 2 기지국 데이터 무선베어러 구성정보 중 적어도 하나 이상의 정보를 포함하는 방법. Cell identifier information associated with the second base station, the second base station cell index information, the second base station cell random access channel preamble information, the second base station cell system information, the second base station cell dedicated MAC layer configuration information, E-RABs (E UTRAN Radio Access Bearers) at least one of the acceptance list information and the second base station data radio bearer configuration information for the accepted E-RAB.
  4. 제 1항에 있어서,The method of claim 1,
    상기 상위계층 시그널링은,The higher layer signaling,
    제 2 기지국 셀 시스템 정보, 제 2 기지국 전용 MAC 계층 구성 정보 및 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 중 적어도 하나 이상의 정보를 더 포함하는 방법.And at least one of second base station cell system information, second base station dedicated MAC layer configuration information, and second base station cell random access channel preamble.
  5. 제 1항에 있어서,The method of claim 1,
    상기 제 2 기지국을 통해 구성되는 데이터 무선베어러 정보는,The data radio bearer information configured through the second base station is
    상기 단말이 MAC 계층에서 상기 제 1 기지국과 상기 제 2 기지국을 구별하기 위한 정보 및 상기 제 1 기지국이 제공하는 셀과 상기 제 2 기지국이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함하는 것을 특징으로 하는 방법.The terminal includes at least one of information for distinguishing the first base station and the second base station in the MAC layer, and information for distinguishing a cell provided by the first base station and a cell provided by the second base station. Characterized in that.
  6. 제 1항에 있어서,The method of claim 1,
    상기 제 2 기지국 셀 인덱스 정보 및 상기 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보는,The second base station cell index information and the data radio bearer information configured through the second base station,
    상기 제 2 기지국이 설정하여 상기 제 1 기지국으로 전송한 정보인 것을 특징으로 하는 방법.And information set by the second base station and transmitted to the first base station.
  7. 단말이 사용자 플레인 데이터를 전송을 제어하는 방법에 있어서,In the method for the terminal to control the user plane data transmission,
    제 1 기지국으로부터 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 상기 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 수신하는 단계;Receiving, from a first base station, higher layer signaling comprising at least one of cell identifier information for a cell associated with a second base station, second base station cell index information, and data radio bearer information configured through the second base station; ;
    상기 상위계층 시그널링에 기초하여 상기 제 2 기지국에 연관된 셀을 추가 또는 수정하고, 상기 사용자 플레인 데이터 전송을 위한 데이터 무선 베어러를 구성하는 단계를 포함하는 방법.Adding or modifying a cell associated with the second base station based on the higher layer signaling and configuring a data radio bearer for the user plane data transmission.
  8. 제 7항에 있어서,The method of claim 7, wherein
    상기 데이터 무선 베어러를 구성하는 단계는,Configuring the data radio bearer,
    MAC 계층에서 상기 제 1 기지국을 위한 MAC 개체 및 상기 제 2 기지국을 위한 MAC 개체를 구분하여 구성하는 것을 특징으로 하는 방법.And distinguishing and configuring a MAC entity for the first base station and a MAC entity for the second base station in a MAC layer.
  9. 제 8항에 있어서,The method of claim 8,
    상기 제 2 기지국을 위한 MAC 개체는,MAC entity for the second base station,
    상기 제 2 기지국을 통해 구성되는 무선 베어러를 위한 스케줄링 우선순위 처리 개체 및 멀티플렉싱 개체를 구분하여 구성되는 것을 특징으로 하는 방법.And a scheduling priority processing entity and a multiplexing entity for the radio bearer configured through the second base station.
  10. 제 7항에 있어서,The method of claim 7, wherein
    상기 상위계층 시그널링은,The higher layer signaling,
    제 2 기지국 셀 시스템 정보, 제 2 기지국 전용 MAC 계층 구성 정보 및 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 중 적어도 하나 이상의 정보를 더 포함하는 방법.And at least one of second base station cell system information, second base station dedicated MAC layer configuration information, and second base station cell random access channel preamble.
  11. 제 7항에 있어서,The method of claim 7, wherein
    상기 제 2 기지국을 통해 구성되는 데이터 무선베어러 정보는,The data radio bearer information configured through the second base station is
    상기 단말이 MAC 계층에서 상기 제 1 기지국과 상기 제 2 기지국을 구별하기 위한 정보 및 상기 제 1 기지국이 제공하는 셀과 상기 제 2 기지국이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함하는 것을 특징으로 하는 방법.The terminal includes at least one of information for distinguishing the first base station and the second base station in the MAC layer, and information for distinguishing a cell provided by the first base station and a cell provided by the second base station. Characterized in that.
  12. 단말의 사용자 플레인 데이터 전송을 제어하는 제 1 기지국에 있어서,In the first base station for controlling the user plane data transmission of the terminal,
    상기 제 1 기지국의 부하 정보 및 측정 리포트 정보 중 적어도 하나 이상의 정보에 기초하여 제 2 기지국을 통해 구성되는 무선 베어러를 선택하여 상기 사용자 플레인 데이터 전송을 결정하는 제어부;A controller configured to determine the user plane data transmission by selecting a radio bearer configured through a second base station based on at least one of load information and measurement report information of the first base station;
    상기 제 2 기지국으로 베어러 설정 요청 메시지를 전송하는 송신부;A transmitter for transmitting a bearer setup request message to the second base station;
    상기 제 2 기지국으로부터 베어러 설정 응답 메시지를 수신하는 수신부; 및A receiver configured to receive a bearer setup response message from the second base station; And
    상기 단말로 상기 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 상기 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 전송하는 송신부를 포함하는 기지국.Transmitter for transmitting higher layer signaling including at least one or more of the cell identifier information, the second base station cell index information and the data radio bearer information configured through the second base station for the cell associated with the second base station to the terminal Base station comprising a.
  13. 제 12항에 있어서,The method of claim 12,
    상기 베어러 설정 요청 메시지는,The bearer setup request message,
    제 1 기지국 단말 X2AP(X2 application protocol) 식별자 정보, 상기 제 2 기지국에 연관된 셀 식별자 정보, 상기 제 2 기지국 셀 인덱스 정보, 단말 총 최대 비트전송율(UE Aggregate Maximum Bit Rate) 및 E-RABs(E-UTRAN Radio Access Bearers) 셋업 리스트 정보 중 적어도 하나 이상의 정보를 포함하는 기지국.First base station terminal X2 application protocol (X2AP) identifier information, cell identifier information associated with the second base station, the second base station cell index information, UE total maximum bit rate and E-RABs (E-RAB) UTRAN Radio Access Bearers) A base station including at least one of the setup list information.
  14. 제 12항에 있어서,The method of claim 12,
    상기 베어러 설정 응답 메시지는,The bearer setup response message,
    상기 제 2 기지국에 연관된 셀 식별자 정보, 상기 제 2 기지국 셀 인덱스 정보, 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 정보, 제 2 기지국 셀 시스템 정보, 제 2 기지국 셀 전용 MAC 계층 구성 정보, E-RABs(E-UTRAN Radio Access Bearers) 수락 리스트 정보 및 상기 수락된 E-RAB에 대한 제 2 기지국 데이터 무선베어러 구성정보 중 적어도 하나 이상의 정보를 포함하는 기지국.Cell identifier information associated with the second base station, the second base station cell index information, the second base station cell random access channel preamble information, the second base station cell system information, the second base station cell dedicated MAC layer configuration information, E-RABs (E UTRAN Radio Access Bearers) A base station comprising at least one information of acceptance list information and second base station data radio bearer configuration information for the accepted E-RAB.
  15. 제 12항에 있어서,The method of claim 12,
    상기 상위계층 시그널링은,The higher layer signaling,
    제 2 기지국 셀 시스템 정보, 제 2 기지국 전용 MAC 계층 구성 정보 및 제 2 기지국 셀 랜덤 액세스 채널 프리앰블 중 적어도 하나 이상의 정보를 더 포함하는 기지국.The base station further includes at least one or more of second base station cell system information, second base station dedicated MAC layer configuration information, and second base station cell random access channel preamble.
  16. 제 12항에 있어서,The method of claim 12,
    상기 제 2 기지국을 통해 구성되는 데이터 무선베어러 정보는,The data radio bearer information configured through the second base station is
    상기 단말이 MAC 계층에서 상기 제 1 기지국과 상기 제 2 기지국을 구별하기 위한 정보 및 상기 제 1 기지국이 제공하는 셀과 상기 제 2 기지국이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함하는 것을 특징으로 하는 기지국.The terminal includes at least one of information for distinguishing the first base station and the second base station in the MAC layer, and information for distinguishing a cell provided by the first base station and a cell provided by the second base station. A base station characterized in that.
  17. 사용자 플레인 데이터를 전송을 제어하는 단말에 있어서,A terminal for controlling transmission of user plane data,
    제 1 기지국으로부터 제 2 기지국에 연관된 셀에 대한 셀 식별자 정보, 제 2 기지국 셀 인덱스 정보 및 상기 제 2 기지국을 통해 구성되는 데이터 무선 베어러 정보 중 적어도 하나 이상의 정보를 포함하는 상위계층 시그널링을 수신하는 수신부;Receiving unit for receiving from the first base station higher layer signaling including at least one or more of the cell identifier information for the cell associated with the second base station, the second base station cell index information and the data radio bearer information configured through the second base station ;
    상기 상위계층 시그널링에 기초하여 상기 제 2 기지국에 연관된 셀을 추가 또는 수정하고, 상기 사용자 플레인 데이터 전송을 위한 데이터 무선 베어러를 구성하는 제어부를 포함하는 단말.And a controller configured to add or modify a cell associated with the second base station based on the higher layer signaling, and configure a data radio bearer for transmitting the user plane data.
  18. 제 17항에 있어서,The method of claim 17,
    상기 제어부는,The control unit,
    MAC 계층에서 상기 제 1 기지국을 위한 MAC 개체 및 상기 제 2 기지국을 위한 MAC 개체를 구분하여 구성하는 것을 특징으로 하는 단말.Terminal for distinguishing and configuring the MAC entity for the first base station and the MAC entity for the second base station in the MAC layer.
  19. 제 18항에 있어서,The method of claim 18,
    상기 제 2 기지국을 위한 MAC 개체는,MAC entity for the second base station,
    상기 제 2 기지국을 통해 구성되는 무선 베어러를 위한 스케줄링 우선순위 처리 개체 및 멀티플렉싱 개체를 구분하여 구성되는 것을 특징으로 하는 단말.And a scheduling priority processing entity and a multiplexing entity for the radio bearer configured through the second base station.
  20. 제 17항에 있어서,The method of claim 17,
    상기 제 2 기지국을 통해 구성되는 데이터 무선베어러 정보는,The data radio bearer information configured through the second base station is
    상기 단말이 MAC 계층에서 상기 제 1 기지국과 상기 제 2 기지국을 구별하기 위한 정보 및 상기 제 1 기지국이 제공하는 셀과 상기 제 2 기지국이 제공하는 셀을 구별하기 위한 정보 중 적어도 하나 이상의 정보를 포함하는 것을 특징으로 하는 단말.The terminal includes at least one of information for distinguishing the first base station and the second base station in the MAC layer, and information for distinguishing a cell provided by the first base station and a cell provided by the second base station. Terminal, characterized in that.
PCT/KR2014/000346 2013-02-01 2014-01-13 Method for transmitting user's plain data in small cell environment and apparatus therefor WO2014119858A1 (en)

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