CN107005903B

CN107005903B - Method for transmitting and receiving single-cell multi-transmission data and apparatus therefor

Info

Publication number: CN107005903B
Application number: CN201680004054.2A
Authority: CN
Inventors: 洪成杓; 崔宇辰
Original assignee: KT Corp
Current assignee: KT Corp
Priority date: 2015-01-08
Filing date: 2016-01-05
Publication date: 2021-01-15
Anticipated expiration: 2036-01-05
Also published as: CN107005903A; KR20160086276A; KR101818833B1

Abstract

The present invention relates to a technique for transmitting and receiving single-cell multi-transmission data. More particularly, the present invention relates to a method and apparatus for providing point-to-multipoint transmission in a single cell in a mobile communication network. In particular, the present invention provides an apparatus and a method comprising the steps of: receiving system information for single-cell multi-transmission in a primary cell (PCell); receiving single-cell multi-transmission control information in a primary cell; and checking whether a neighboring cell provides single-cell multi-transmission using the single-cell multi-transmission control information.

Description

Method for transmitting and receiving single-cell multi-transmission data and apparatus therefor

Technical Field

The present invention relates to a technique for transmitting and receiving single-cell multi-transmission data. More particularly, the present invention relates to a method and apparatus for providing point-to-multipoint transmission in a single cell in a mobile communication network.

Background

The 3GPP Long Term Evolution (LTE) employs a Group Communication System Enabler (GCSE) to transmit data to multiple UEs when emergency communication (e.g., a common disaster) is required.

However, 3GPP release 12 uses Multimedia Broadcast Multicast Service (MBMS) for enabling a group of UEs to receive group communications.

MBMS is designed to provide media content for mobile TV in a large-scale pre-planned area (e.g., MBSFN area). MBSFN areas are to some extent static. Furthermore, MBSFN areas cannot be dynamically adjusted according to user distribution. MBMS transmissions occupy the entire system bandwidth. Furthermore, MBMS transmission does not allow unicast and multiplexing in the same sub-frame, even if not all radio resources are used in the frequency domain.

As described above, since the MBMS occupies the entire system bandwidth and is static, it cannot be dynamically adjusted according to the number of groups or traffic load. This results in inefficiency in the base station transmitting group communication data to a plurality of UEs.

Disclosure of Invention

Technical problem

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method and apparatus for dynamically transmitting and receiving multi-transmission data through a PDSCH when transmitting and receiving multi-transmission data to and from a group including a plurality of UEs in a single cell.

The present invention is also directed to proposing a method and apparatus capable of transmitting and receiving multi-transmission data through a PDSCH while minimizing a group communication service interruption occurring due to a UE moving from cell to cell.

Technical scheme

In order to solve the above problem, the present invention provides a method for a User Equipment (UE) to receive single-cell multi-transmission data, the method comprising: receiving system information for single-cell multi-transmission in a primary cell (PCell); receiving single-cell multi-transmission control information in a primary cell; and using the single-cell multi-transmission control information to identify whether a neighboring cell provides single-cell multi-transmission.

In addition, the present invention provides a method for a base station to transmit single-cell multi-transmission data, the method comprising: transmitting system information for single-cell multi-transmission in a primary cell (PCell); generating single-cell multi-transmission control information; and sending the single-cell multi-transmission control information to the UE in the primary cell.

The present invention also provides a UE apparatus for receiving single-cell multi-transmission data, the UE apparatus comprising: a receiving unit configured to receive system information for single-cell multi-transmission in a primary cell (PCell) and receive single-cell multi-transmission control information in the primary cell; and a control unit configured to identify whether a neighboring cell provides single-cell multi-transmission using the single-cell multi-transmission control information.

In addition, the present invention provides a base station apparatus for transmitting single-cell multi-transmission data, the base station apparatus comprising: a control unit configured to generate single-cell multi-transmission control information; and a transmitting unit configured to transmit system information for single-cell multi-transmission in a primary cell (PCell) and transmit the single-cell multi-transmission control information to the UE in the primary cell.

Advantageous effects

As described above, the present invention can dynamically transmit and receive multi-transmission data to and from a group including a plurality of UEs in a single cell through a PDSCH, thereby providing an effect of efficiently using radio resources.

Further, the present invention provides an effect of being able to transmit and receive multi-transmission data through a PDSCH while minimizing a group communication service interruption due to a UE moving from cell to cell.

Drawings

Fig. 1 shows a mapping between downlink transport channels and downlink physical channels;

fig. 2 shows a mapping between a downlink logical channel and a downlink transport channel;

fig. 3 shows a layer two structure of a downlink configured with Carrier Aggregation (CA);

FIG. 4 illustrates the operation of a User Equipment (UE) according to one embodiment of the present invention;

FIG. 5 illustrates an operation of a UE according to another embodiment of the present invention;

FIG. 6 illustrates an operation of a UE according to still another embodiment of the present invention;

FIG. 7 illustrates the operation of a base station according to an embodiment of the present invention;

fig. 8 illustrates a configuration of a UE according to still another embodiment of the present invention; and

fig. 9 shows a configuration of a base station according to still another embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When reference is made to components in each drawing, the same components will be denoted by the same reference numerals if possible (although they are shown in different drawings). Further, in the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it is determined that such detailed description may make the subject matter of the present invention rather unclear.

In this specification, an MTC terminal may refer to a terminal supporting low cost (or low complexity), a terminal supporting coverage enhancement, and the like. In this specification, an MTC terminal may refer to a terminal or the like supporting low cost (or low complexity) or supporting coverage enhancement. Alternatively, in this specification, MTC terminals refer to predetermined classes defined for maintaining low cost (or low complexity) and/or coverage enhancement.

In other words, in this specification, an MTC terminal may refer to a newly defined 3GPP release 13 low cost (or low complexity) UE class/type that performs LTE-based MTC-related operations. Alternatively, in this specification, an MTC terminal may refer to a UE class/type defined in or before 3GPP release 12 that supports enhanced coverage or supports low power consumption compared to existing LTE coverage, or may refer to a low-cost (or low-complexity) UE class/type newly defined release 13.

Wireless communication systems may be widely deployed to provide various communication services such as voice services, packet data, and so on. A wireless communication system may include a User Equipment (UE) and a base station (BS or eNB). Throughout the specification, user equipment may be an inclusive concept representing a user terminal used in wireless communication, including UE (user equipment) in Wideband Code Division Multiple Access (WCDMA), LTE, High Speed Packet Access (HSPA), etc., and MS (mobile station), UT (user terminal), SS (subscriber station), wireless device, etc., in global system for mobile communications (GSM).

A base station or cell may generally refer to a station that communicates with User Equipment (UE), and may also be referred to as a Node-B (Node-B), an evolved Node-B (enb), a sector, a site, a Base Transceiver System (BTS), an access point, a relay Node, a Remote Radio Head (RRH), a Radio Unit (RU), a small cell, and so on.

That is, a base station or a cell may be understood as an inclusive concept indicating a part of an area covered by a BSC (base station controller) in CDMA, a Node B in WCDMA, an eNB or a sector (site) in LTE, or the like, or the function, and the concept may include various coverage areas such as a communication range of a megacell, a macrocell, a microcell, a picocell, a femtocell, a relay Node, an RRH, an RU, a small cell, or the like.

Each of the above-mentioned cells has a base station controlling the corresponding cell, and therefore, the base station can be explained in two ways: i) the base station may be the device itself that provides the megacells, macrocells, microcells, picocells, femtocells, and microcells associated with the wireless area; or ii) the base station may refer to the wireless region itself. In i), all devices that the apparatus providing the predetermined wireless area can be controlled by the same entity or interact with each other to cooperatively configure the wireless area may be referred to as a base station. The eNB, RRH, antenna, RU, Low Power Node (LPN), point, transmission/reception point, transmission point, reception point, etc. may be an embodiment of a base station based on a configuration type of a wireless area. In ii), the wireless area in which a signal is received or transmitted may itself be referred to as a base station from the viewpoint of the terminal or the neighboring base station.

Accordingly, a macrocell, a microcell, a picocell, a femtocell, a microcell, an RRH, an antenna, an RU, an LPN, a point, an eNB, a transmission/reception point, a transmission point, and a reception point are collectively referred to as a base station.

In this specification, a user equipment and a base station are used as two inclusionary transceiving objects to implement the technology and technical concept described in the specification, and may not be limited to predetermined terms or words. In this specification, a user equipment and a base station are used as two (uplink and downlink) inclusionary transceiving objects to implement the technology and technical concept described in the specification, and may not be limited to predetermined terms or words. Here, Uplink (UL) refers to a scheme for a UE to transmit data to and receive data from a base station, and Downlink (DL) refers to a scheme for a base station to transmit data to and receive data from a UE.

Various multiple access schemes applied to the wireless communication system may not be limited. Various multiple access schemes may be used, including 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, and the like. Embodiments of the present invention may be applicable to resource allocation in asynchronous wireless communication schemes that have evolved into LTE and LTE-a through GSM, WCDMA, and HSPA, and may be applicable to resource allocation in synchronous wireless communication schemes that have evolved into UMB through CDMA, CDMA-2000. The present invention may not be limited to a specific wireless communication field and may include all technical fields to which the technical idea of the present invention is applicable.

The uplink transmission and the downlink transmission may be performed according to a TDD (time division duplex) scheme in which transmission is performed based on different times or according to an FDD (frequency division duplex) scheme in which transmission is performed based on different frequencies.

Further, in systems such as LTE and LTE-a, standards may be developed by configuring uplink and downlink on a single carrier or a pair of carriers basis. The uplink and downlink may transmit control information through a control channel such as PDCCH (physical downlink control channel), PCFICH (physical control format indicator channel), PHICH (physical hybrid ARQ (automatic repeat request) indicator channel), PUCCH (physical uplink control channel), EPDCCH (enhanced physical downlink control channel), etc., and may be configured as a data channel such as PDSCH (physical downlink shared channel), PUSCH (physical uplink shared channel), etc., thereby transmitting data.

The control information may be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

In this specification, a cell may refer to a coverage of a signal transmitted from a transmission/reception point, a component carrier having a coverage of a signal transmitted from a transmission/reception point (transmission point or transmission/reception point), or a transmission/reception point itself.

The wireless communication system according to the embodiment refers to a coordinated multi-point transmission/reception (CoMP) system, a coordinated multi-antenna transmission system, or a coordinated multi-cell communication system in which two or more transmission/reception points cooperatively transmit a signal. The CoMP system may include at least two multi-transmission/reception points and a terminal.

The multiple transmission/reception points may be a base station or a macro cell (hereinafter referred to as "eNB") and at least one RRH which is connected to the eNB through an optical cable or an optical fiber and is wire-controlled and has high transmission power or low transmission power within a macro cell area.

Hereinafter, downlink refers to a communication or communication path from a multi transmission/reception point to a terminal, and uplink refers to a communication or communication path from a terminal to a multi transmission/reception point. In the downlink, the transmitter may be part of multiple transmission/reception points, and the receiver may be part of a terminal. In the uplink, the transmitter may be part of a terminal and the receiver may be part of multiple transmit/receive points.

Hereinafter, the case of transmitting and receiving signals through PUCCH, PUSCH, PDCCH, PDSCH, etc. may be described by the following expression: "transmit or receive PUCCH, PUSCH, PDCCH, or PDSCH".

Further, hereinafter, the expression "transmitting or receiving PDCCH or transmitting or receiving signal through PDCCH" includes "transmitting or receiving EPDCCH or transmitting or receiving signal through EPDCCH".

That is, the physical downlink control channel used herein may refer to PDCCH or EPDCCH, and may refer to a meaning including both PDCCH and EPDCCH.

Also, for convenience of description, the EPDCCH corresponding to an embodiment of the present invention may be applied to a portion described using the PDCCH and to a portion described using the EPDCCH.

Meanwhile, in the specification, the higher layer signaling includes RRC signaling transmitting RRC information including RRC parameters.

The eNB performs downlink transmission directed to the terminal. The eNB may transmit a Physical Downlink Shared Channel (PDSCH), which is a main physical channel for unicast transmission, and may also transmit a Physical Downlink Control Channel (PDCCH) for transmitting downlink control information (e.g., scheduling required to receive the PDSCH) and scheduling grant information for transmitting an uplink data channel (e.g., a Physical Uplink Shared Channel (PUSCH)). Hereinafter, transmitting and receiving a signal through each channel will be described as transmitting and receiving a corresponding channel.

The present invention relates to a method and apparatus for transmitting and receiving single-cell multi-transmission data.

In conventional E-UTRAN, the group UEs need to use static areas or static radio resource configurations to receive group communication data (downlink multicast or multicast) using Multimedia Broadcast Multicast Service (MBMS). To eliminate such inefficiency, a method of receiving the same downlink data through the PDSCH in the multicast mode may be considered. However, a specific procedure for a plurality of group UEs to receive downlink data through the PDSCH has not been provided yet. In addition, the method of receiving downlink group communication data through the PDSCH may be independently performed in each cell, and thus service continuity cannot be guaranteed when a cell is changed by movement of the UE. In order to solve the above problems, the present invention is directed to providing a method and apparatus for receiving downlink group communication data through a PDSCH. Further, the present invention provides a method and apparatus capable of receiving group communication data through a PDSCH while minimizing a traffic interruption occurring due to movement of a UE from cell to cell.

Fig. 1 shows a mapping between a downlink transport channel and a downlink physical channel. Referring to fig. 1, the PDSCH physical channel may currently be used only to carry a DL-SCH (downlink shared channel) transport channel and a PCH (paging channel) transport channel.

Fig. 2 shows a mapping between a downlink logical channel and a downlink transport channel. Referring to fig. 2, DL-SCH transport channels may be mapped to BCCH (broadcast control channel) logical channels, CCCH (common control channel) logical channels, DCCH (dedicated control channel) logical channels, and DTCH (dedicated transport channel) logical channels and transmitted.

The PCCH is used to transmit paging information and system information change notification. For example, in order for an idle mode UE to receive paging, when the UE wakes up in a corresponding paging occasion and detects P (paging) -RNTI (radio network temporary identity) for addressing a paging message transmitted on a PDCCH, the UE may process to receive a corresponding downlink paging message transmitted on a PCH.

The BCCH is used to broadcast system control information. For example, a Master Information Block (MIB) on the BCCH logical channel is mapped to the BCH and transmitted through the PBCH. In another example, System Information Blocks (SIBs) on the BCCH logical channel other than SIB1 are mapped to a system information message (SI message) and transmitted through the DL-SCH. The mapping of SIBs other than SIB1 to SI messages is flexible and indicated by SIB 1. The UE needs to acquire the SIB1 to identify how other SIBs are scheduled. Each SIB is included in a single SI message, and the single SI message may include multiple SIBs having the same periodicity. The SI messages are dynamically scheduled. SI messages may be sent within periodic time windows called SI windows. Each SI message is associated with one SI window, and other SI messages are broadcast on other non-overlapping SI windows. When broadcasting SIB1 and SI messages on DL-SCH, the PDCCH associated with DL-SCH uses a single SI (system message) -RNTI to address SIB1 and all SI messages within one cell. The UE decodes the SI-RNTI on the PDCCH within the SI window to obtain detailed scheduling of system information in the SI window.

The CCCH is used to transmit control information for random access connection with UEs that do not have an RRC connection. RRC messages on CCCH may be repeatedly received because MAC HARQ retransmission may be performed.

The DCCH is a point-to-point channel used to transmit dedicated control information to UEs having an RRC connection. The DTCH is a point-to-point channel dedicated to the UE for transmitting user information.

The UE receives downlink allocation through the PDCCH masked with the C-RNTI of the UE. The downlink allocation indicates HARQ information and information on radio resources on the allocated PDSCH.

FIG. 3 shows a layer two structure of a downlink configured with Carrier Aggregation (CA)

As described above, the PDSCH may be used to receive dedicated information for a specific UE and common information for a specific UE. For this, a UE-specific identifier (e.g., C-RNTI) of the UE is required. In addition, the PDSCH may be used to receive paging information and common information for all UEs or a group of UEs. For this, a common group identifier (e.g., P-RNTI and SI-RNTI) is required. In E-UTRAN, FFFE is used as the P-RNTI value and FFFF is used as the SI-RNTI value.

In the description of the present specification, transmitting data through PDSCH radio resources shared among UEs included in a specific group in one cell is referred to as single-cell multi-transmission (single-cell multi-transmission), and downlink multicast data, or group communication data transmitted through PDSCH radio resources shared among UEs included in a specific group in one cell is referred to as single-cell multi-transmission data. Further, a communication mode of transmitting and receiving data by single-cell multi-transmission is referred to as group communication.

Also, a group specific identifier (group-specific RNTI) allocated to a specific group for transmitting single-cell multi-transmission data is referred to as group identification information (group RNTI: G-RNTI). A service provided to the UE through group communication is referred to as a group communication service, and information for identifying each group communication service, group communication session, or group communication bearer is referred to as group communication service identification information (temporary mobile group identity: TMGI). Further, UEs that desire group communication are collectively referred to as UEs that desire group communication, i.e., UEs that desire group communication via single-cell multi-transmission and UEs that are capable of single-cell multi-transmission.

Meanwhile, the UE needs information for identifying a single cell multi-transmission control message transmitted by the base station, which is defined as single cell-RNTI (SC-RNTI). The UE may identify single-cell multi-transmission control information using the SC-RNTI. The single cell multi-transmission control message includes control information for single cell multi-transmission.

The foregoing terms are provided for convenience of understanding and are not intended to be limiting.

A UE desiring group communication may know the TMGI identifying a particular group communication service desired through an application server (e.g., GCS AS or BM-SC). Alternatively, the TMGI may be preconfigured in the UE to identify the particular group communication service desired.

For downlink transmission of the group communication service, one of MBMS, single cell multi-transmission, and unicast bearer may be used. Further, for uplink transmission, a unicast bearer may be used.

When using MBMS, MBMS bearers pre-configured between a broadcast/multicast service center (BM-SC) and a base station may be used to establish a group communication service/session/bearer. Alternatively, an MBMS bearer for use between the BM-SC and the eNB may be configured through an activated MBMS bearer procedure according to a request from a group communication service application server (GCS AS). One or more of a TMGI for identifying a downlink MBMS bearer service for group communication, an MBMS session Identification (ID) for identifying each MBMS session, MBSFN area identification information, and identification information for identifying a downlink service/session/bearer for a group communication service/session/bearer may be allocated through a BM-SC, a GCS AS, or another Evolved Packet System (EPS) entity, and may be provided to the UE through an EPS entity controlling group communication (e.g., a GCS AS, an IMS (IP multimedia subsystem), a PCRF (policy and charging rules function), other EPS entity), or through an EPS entity controlling registration (or authentication or verification). To receive downlink transmissions for group communications using MBMS, a UE may register in the GCS AS, an EPS entity controlling group communications, or an EPS entity controlling registration (or authentication or verification). According to another method, a TMGI for identifying a downlink MBMS bearer service for group communication, an MBMS session Identification (ID) for identifying each MBMS session, MBSFN area identification information, and group identification information for group communication may be preconfigured in a UE. When the GCS AS or the EPS entity controlling group communication determines to provide downlink transmission for group communication in a specific cell through MBMS, the GCS AS, the EPS entity controlling group communication, or the EPS entity controlling registration (or authentication or verification) may start an MBMS session with the base station through the BM-SC.

When using single-cell multi-transmission, the base station allocates the G-RNTI to provide a group-specific communication service through single-cell multi-transmission. The G-RNTI may be associated with the TMGI. Alternatively, the G-RNTI may be associated with the TMGI and/or the MBMS session ID. Alternatively, the G-RNTI may be associated with a downlink service of the group communication service. Alternatively, the G-RNTI may be associated with identification information for identifying a downstream service/session/bearer of the group communication service/session/bearer.

Fig. 4 illustrates an operation of a UE according to an embodiment of the present invention.

A method is disclosed in which a UE receives single-cell multi-transmission data, which includes receiving system information for single-cell multi-transmission in a primary cell (PCell), receiving single-cell multi-transmission control information in the PCell, and identifying whether a neighboring cell provides single-cell multi-transmission using the single-cell multi-transmission control information.

Referring to fig. 4, a UE receives system information for single-cell multi-transmission in a PCell (step S410). For example, the base station may transmit system information for single-cell multi-transmission through a PCell configured for the UE, and the UE may receive the system information for single-cell multi-transmission. For example, the base station may broadcast information on single-cell multi-transmission through system information. Specifically, the base station may broadcast the G-RNTI through system information. Alternatively, the base station may broadcast the TMGI and the G-RNTI associated with the TMGI via system information. Alternatively, the base station may broadcast identification information for identifying a downlink service/session/bearer of the group communication service/session/bearer and the G-RNTI associated with the identification information through the system information. In another example, the base station may broadcast information for receiving single cell multi-transmission control information including the G-RNTI through system information. Alternatively, the base station may broadcast information for receiving single cell multi-transmission control information including the TMGI and the G-RNTI associated with the TMGI through system information. Alternatively, the base station may broadcast information for receiving single cell multi transmission control information including identification information for identifying a downlink service/session/bearer of the group communication service/session/bearer and a G-RNTI associated with the identification information through system information. Accordingly, the UE may identify the G-RNTI for the group communication. The UE may be able to identify whether a cell provides single-cell multi-transmission and identify a group communication service provided by the cell by receiving system information.

Further, the UE receives single-cell multi-transmission control information in the PCell (step S420). The single cell multi-transmission control information may be scheduled by system information for single cell multi-transmission. For example, the UE may receive system information for identifying a period and an offset for transmitting single-cell multi-transmission control information in step S410. That is, the UE may receive single-cell multi-transmission control information scheduled by system information.

Meanwhile, the single cell multi-transmission control information may include information on a neighbor cell providing single cell multi-transmission. Alternatively, the single-cell multi-transmission control information may include information on a group communication service that can be provided by each cell. Alternatively, the single-cell multi-transmission control information may include corresponding information regarding matching of the group communication service and the neighboring cells. For example, the single cell multi-transmission control information may include at least one of cell identification information on a neighbor cell providing single cell multi-transmission, TMGI, and information on a neighbor cell providing single cell multi-transmission associated with G-RNT. Accordingly, the UE can acquire information on a neighbor cell providing a desired group communication service. Alternatively, the UE may identify information about neighboring cells that provide single-cell multi-transmission. The single cell multi-transmission control information may be indicated through the PDCCH.

Further, the UE identifies whether the neighboring cell provides single-cell multi-transmission using the single-cell multi-transmission control information (step S430). The UE may use the received single cell multi-transmission control information to identify whether a neighboring cell provides single cell multi-transmission. Alternatively, the UE may identify the type of group communication service provided by the neighboring cell. Alternatively, the UE may identify neighboring cells that provide the group communication service that the UE desires to perform. Alternatively, the UE may identify a cell that provides single-cell multi-transmission. Accordingly, the UE can recognize whether the neighbor cell provides single-cell multi-transmission or whether group communication that the UE wants to perform is provided without checking system information on the neighbor cell.

Meanwhile, the UE may receive single-cell multi-transmission data using the G-RNTI. For example, the UE may receive single-cell multi-transmission data through PDSCH radio resources. Other UEs in the same group as the UE may also receive single-cell multi-transmission data through the shared PDSCH radio resource, and the UE may receive scheduling information on the PDSCH through the PDCCH region, thereby receiving single-cell multi-transmission data through the PDSCH radio resource. Meanwhile, the UE may identify whether single-cell multi-transmission data relates to a group communication service that the UE intends to perform using the allocated G-RNTI.

As described above, the UE of the present invention can receive single-cell multi-transmission data regarding a group communication service through the PDSCH region and can recognize whether a neighbor cell provides single-cell multi-transmission through the serving cell. The UE may identify whether to provide single-cell multi-transmission or whether to provide group communication service so as to continuously receive single-cell multi-transmission data while moving.

Fig. 5 illustrates an operation of a UE according to another embodiment of the present invention.

The UE of the present invention may request to receive a group communication service through unicast when a neighbor cell does not provide single-cell multi-transmission.

Referring to fig. 5, as described above with reference to steps S410 to S430, the UE of the present invention may receive system information for single-cell multi-transmission in the PCell (step S510), and may receive single-cell multi-transmission control information in the PCell (step S520). The base station may broadcast the G-RNTI through system information. Alternatively, the base station may broadcast the TMGI and the G-RNTI associated with the TMGI via system information. Alternatively, the base station may broadcast identification information for identifying a downlink service/session/bearer of the group communication service/session/bearer and the G-RNTI associated with the identification information through the system information. In another example, the base station may broadcast information for receiving single cell multi-transmission control information including the G-RNTI through system information. Alternatively, the base station may broadcast information for receiving single cell multi-transmission control information including the TMGI and the G-RNTI associated with the TMGI through system information. Alternatively, the base station may broadcast information for receiving single cell multi transmission control information including identification information for identifying a downlink service/session/bearer of the group communication service/session/bearer and a G-RNTI associated with the identification information.

The single-cell multi-transmission control information may be scheduled by system information for single-cell multi-transmission. For example, the UE may receive system information to identify a period and offset value for transmitting single-cell multi-transmission control information, and the like. That is, the UE may receive the single-cell multi-transmission control information at a time scheduled by the system information. Meanwhile, the single cell multi-transmission control information may include information on a neighbor cell providing single cell multi-transmission. Alternatively, the single-cell multi-transmission control information may include information on a group communication service that can be provided by each cell. Alternatively, the single-cell multi-transmission control information may include information on correspondence between the group communication service and the cell. For example, the single cell multi-transmission control information may include at least one of cell identification information on a neighbor cell providing single cell multi-transmission, a TMGI, and information on a neighbor cell providing single cell multi-transmission associated with the G-RNTI.

The UE may use the single-cell multi-transmission control information to identify whether a neighboring cell provides single-cell multi-transmission (step S530). The UE may use the received single cell multi-transmission control information to identify whether a neighboring cell provides single cell multi-transmission. Alternatively, the UE may identify the type of group communication service provided by the neighboring cell. Alternatively, the UE may identify neighboring cells that provide the group communication service that the UE desires to perform. Alternatively, the UE may identify a cell that provides single-cell multi-transmission.

When the neighbor cell does not provide single-cell multi-transmission, the UE may request to receive a group communication service through unicast before the cell change (step S540). For example, AS a result of identifying the control information, when the neighbor cell to which the UE wants to move does not provide single-cell multi-transmission for the group communication service that the UE wants to perform, the UE may directly request the group communication service through unicast through the GCS AS. For example, when receiving a group communication service through single-cell multi-transmission in the Pcell, the UE may request the group communication service through unicast. In another example, the RRC-connected UE may request a group communication service through unicast directly through the GCS AS. In yet another example, an RRC-idle UE may establish an RRC connection and may then request a group communication service through unicast through the GCS AS. The end-to-end delay for media delivery using unicast bearers is about 40 ms. Meanwhile, the end-to-end delay of media delivery using MBMS MRB (MBMS point-to-multipoint radio bearer) is about 160 ms. Therefore, in order to provide service continuity, if a neighbor cell to which a UE wants to move does not support single-cell multi-transmission, the UE may first request a service through unicast even if the neighbor cell supports MBMS (or group communication through MBMS or MBSFN providing the same service), thereby reducing service interruption. Subsequently, the UE moves to the target cell and can receive the group communication service through the MBMS.

Fig. 6 illustrates an operation of a UE according to still another embodiment of the present invention.

The UE of the present invention can perform a cell reselection procedure by assigning the highest priority to the frequency of the cell providing single-cell multi-transmission.

Referring to fig. 6, as described above with reference to fig. 4 and 5, the UE may receive system information for single-cell multi-transmission in the PCell (step S610), and may receive single-cell multi-transmission control information in the PCell (step S620). The UE may identify whether the neighboring cell provides single-cell multi-transmission through the received control information (step S630).

The RRC-idle UE may perform a cell reselection procedure by assigning the highest priority to the frequency of the cell providing single-cell multi-transmission (step S640). The UE may receive single-cell multi-transmission data in the PCell. Alternatively, the UE may move to a neighboring cell that provides single cell multiple transmission to receive single cell multiple transmission data. In this case, the UE may assign the highest priority to the frequency of the cell providing single-cell multi-transmission when performing cell reselection. For example, at the time of cell reselection, unlike handover, frequencies are detected and selected according to priorities assigned to the frequencies. Therefore, a problem may occur in that a UE that is or is expected to use a single-cell multi-transmission reception group communication service selects a cell that does not provide single-cell multi-transmission according to priorities assigned to frequencies at the time of cell reselection. To address this problem, the UE may assign a highest priority to a cell providing a group communication service that the UE wants to perform or is receiving in a cell reselection procedure, thereby preventing the group communication service from being interrupted due to the cell reselection procedure. The specific priority assignment method is described in detail below.

Hereinafter, operations of the UE and the base station of the present invention are described in detail in fig. 4 to 6 with reference to the detailed embodiments.

The base station may broadcast information on single-cell multi-transmission through system information. For example, the base station may broadcast the G-RNTI. In another example, the base station may broadcast the TMGI and the G-RNTI associated with the TMGI. In yet another example, the base station may broadcast identification information for identifying a downlink service/session/bearer of the group communication service/session/bearer and the G-RNTI associated with the identification information. In yet another example, a base station may broadcast information for receiving single-cell multi-transmission control information including a G-RNTI. In yet another example, a base station may broadcast information for receiving single cell multi-transmission control information including a TMGI and a G-RNTI associated with the TMGI. In another example, a base station may broadcast information for receiving single cell multi-transmission control information including identification information for identifying a downlink service/session/bearer of a group communication service/session/bearer and a G-RNTI associated with the identification information. Accordingly, the UE intending to perform the corresponding group communication can recognize the G-RNTI corresponding to the group communication service.

When a UE desiring group communication that receives (or is receiving) a downlink transmission for a particular group communication sent via a single-cell multi-transmission moves between cells (or moves between base stations or moves to another base station cell), service continuity needs to be provided to reduce service interruption. The method of providing service continuity in each scenario is as follows.

Scene 1: UE moves from a cell supporting single-cell multi-transmission to a cell not supporting single-cell multi-transmission

While staying in the source cell, the UE may identify whether the neighbor cell to which the UE wants to move supports single-cell multi-transmission based on single-cell multi-transmission system information about the neighbor cell, control information associated with the single-cell multi-transmission system information, or control information for identifying whether the neighbor cell supports single-cell multi-transmission.

When the neighbor cell to which the UE wants to move does not support single-cell multi-transmission, the UE can request a service through unicast while receiving the service through single-cell multi-transmission in the source cell. The RRC-connected UE may request a service through unicast directly through the GCS AS. RRC-idle UEs may establish RRC connections and may then request services over unicast through the GCS AS.

The end-to-end delay for media delivery using unicast bearers is about 40 ms. Meanwhile, the end-to-end delay of media delivery using MBMS MRB is about 160 ms. Therefore, in order to provide service continuity, if a neighbor cell to which a UE wants to move does not support single-cell multi-transmission, the UE may first request a service through unicast even if the neighbor cell supports MBMS (or group communication through MBMS or MBSFN providing the same service), thereby reducing service interruption. Subsequently, the UE moves to the target cell and can receive the group communication service through the MBMS.

When a UE moves from a single-cell multi-transmission cell to a cell that does not support single-cell multi-transmission, the UE may experience a short service interruption. AS another method for avoiding or mitigating service interruption, when a UE receives a single-cell multi-transmission, a source cell (or source base station) may forward data transmitted through a BM-SC (or GCS AS or any group communication data transmission entity) to a target cell (target base station).

For example, when the target cell/base station receives group communication data transmitted through the BM-SC (or the GCS AS or any group communication data transmission entity) through the source cell/base station, the target base station may transmit the data to the UE. For example, the target base station may transmit data through single-cell multi-transmission. To this end, the target base station may receive and use the G-RNTI from the source base station via a handover preparation message. In preparation for the handover, a data forwarding tunnel for the data may be configured. In another example, the target base station may transmit data over the data radio bearer of the UE. During preparation for handoff, a data forwarding tunnel for the data may be configured.

Scene 2: UE moves from single-cell multi-transmission transmitting cell to single-cell multi-transmission transmitting cell

While staying in the source cell, the UE may identify whether the neighboring cell to which the UE wants to move supports single-cell multi-transmission based on single-cell multi-transmission system information on the neighboring cell, control information associated with the system information on single-cell multi-transmission, or control information for identifying whether the neighboring cell supports single-cell multi-transmission.

Hereinafter, embodiments for providing service continuity for RRC-idle UEs are described in detail.

According to one method for providing service continuity for RRC-idle UEs, single-cell multi-transmission related information for a specific group communication service/session/bearer of a neighboring cell or a neighboring base station (hereinafter, referred to as a neighboring cell) may be provided through X2 signaling (e.g., X2 setup and eNB configuration update procedure) and/or operation, administration, and maintenance (OAM).

When receiving single-cell multi-transmission system information on a neighbor cell, control information associated with the single-cell multi-transmission system information, or control information capable of identifying whether the neighbor cell supports single-cell multi-transmission, a base station may broadcast the single-cell multi-transmission information on the neighbor cell through the single-cell multi-transmission system information, the control information associated with the single-cell multi-transmission system information, or the control information capable of identifying whether the neighbor cell supports single-cell multi-transmission, thereby supporting service continuity of a UE.

The single-cell multi-transmission information on the neighbor cell and/or detailed information included in the single-cell multi-transmission system information or the control information associated with the single-cell multi-transmission system information or the control information for identifying whether the neighbor cell supports single-cell multi-transmission to be broadcasted and may be provided through OAM, which is included in the above-mentioned X2 signaling, may include cell identification information, TMGI, G-RNTI, and identification information for identifying a downlink service/session/bearer of a group communication service/session/bearer.

The UEs desiring to perform group communication may avoid reading the single-cell multi-transmission system information or related control information in the neighboring cell or at the neighboring frequency through the above-described system information, control information associated with the single-cell multi-transmission system information, or control information for identifying whether the neighboring cell supports the single-cell multi-transmission. Alternatively, the UE desiring to perform group communication may know whether to provide single-cell multi-transmission, which group communication service is provided, or which group communication service based on single-cell multi-transmission through the above-described system information, control information associated with the single-cell multi-transmission system information, or control information for identifying whether a neighboring cell supports single-cell multi-transmission.

For example, a UE desiring to perform group communication or a UE receiving group communication through single cell multi transmission can know physical layer cell identification information (physcellld) on a neighboring cell through cell search. For example, the physical layer cell identification information may have a value ranging from 0 to 503. Therefore, when the serving cell broadcasts single-cell multi-transmission information on the neighbor cell through intra-cell system information, the UE can avoid reading the single-cell multi-transmission system information on the neighbor cell through the information.

For example, when the base station broadcasts a mapping of a single-cell multi-transmission (e.g., TMGI, GRNTI, or identification/identification information on a group communication service/session/bearer) for a specific group service/session/bearer and cell identification information (e.g., physcellld or CellIdentity) for a neighbor cell providing the single-cell multi-transmission in a serving cell, the UE can know whether the neighbor cell provides the single-cell multi-transmission for the specific group service/session/bearer through the physical layer cell identification information obtained (or determined) in a cell search procedure for the neighbor cell, without reading system information on the neighbor cell.

In another example of providing service continuity for RRC-idle UEs, when a cell to be reselected (reselected cell) provides single-cell multi-transmission for group communications, UEs that want to perform group communications or RRC-idle UEs that are currently receiving group communications through single-cell multi-transmission may be assigned the same priority to the current cell or current cell frequency in a cell reselection procedure. For example, the UE may assign the cell or cell frequency the same cell reselection priority as the priority of the current cell frequency even if the cell reselection priority of the cell frequency is lower than the priority of the current serving cell (or pre-reselection cell) frequency. That is, the cell may be allowed to have a cell-specific reselection priority.

Alternatively, when the cell to be reselected (reselected cell) provides single-cell multi-transmission for group communication, the UE desiring to perform group communication or the RRC-idle UE currently receiving group communication through single-cell multi-transmission may be assigned the highest priority to the cell to be reselected, the cell frequency to be reselected, or the single-cell multi-transmission providing frequency in the cell reselection procedure. For example, the UE may assign a highest cell reselection priority to the cell frequency or single cell multiple transmission providing frequency even if the cell reselection priority is lower than the priority of the current serving cell (or pre-reselection cell) frequency. That is, the cell may be allowed to have a cell-specific reselection priority.

Alternatively, when the current cell provides single-cell multi-transmission for group communication, the RRC-idle UE that wants to perform group communication or the RRC-idle UE that is currently receiving group communication through single-cell multi-transmission may consider the cell or cell frequency as the highest priority.

Alternatively, when reselecting a cell to provide MBMS transmissions for the group communication, RRC-idle UEs that want to perform the group communication or RRC-idle UEs that are currently receiving group communication via single-cell multiple transmission may treat the cell providing the MBMS service as the highest priority.

When each frequency is assigned a frequency-specific cell reselection priority, if the UE is receiving or wants to receive the MBMS service and can receive the MBMS service while the UE is camped on the MBMS service provision frequency, the UE may consider the frequency as the highest priority frequency in the MBMS session. However, when using single-cell multi-transmission, the cells/base stations may operate independently even if the same frequency is used. Furthermore, the configuration of the single-cell multi-transmission region may not be frequency dependent. Thus, while the serving cell frequency provides single cell multi-transmission, if the frequency is configured to be considered the highest priority, it is highly likely that a cell that does not provide the corresponding group communication will be reselected. As described above, the present invention can solve this problem by adjusting the priority of a cell providing single-cell multi-transmission or a cell currently receiving data through single-cell multi-transmission.

Meanwhile, a specific embodiment is shown below in which a cell reselection priority is assigned to a cell providing single-cell multi-transmission or a cell providing a specific group communication service that a UE wants to perform through single-cell multi-transmission in the above-described cell reselection procedure.

For example, when a UE desiring to perform group communication does not receive a single-cell multi-transmission, the UE may consider a cell providing a single-cell multi-transmission as the highest priority if a neighboring cell provides a single-cell multi-transmission for group communication. Thus, when a cell satisfies square > Threshx, HighQ or square > Threshx, HighP during the time interval Treselection, the UE may reselect a neighboring cell with higher priority in the cell reselection procedure. Here, Threshx, HighQ, and Threshx, HighP denote preset thresholds, and Squal denotes a value indicating cell reselection quality (see 3GPP ts.36.304, section 5.2).

In another example, when a UE desiring to perform group communication does not receive a single-cell multi-transmission, the UE may consider a cell frequency providing a single-cell multi-transmission as the highest priority if a neighboring cell provides a single-cell multi-transmission for group communication. Therefore, when a cell with a higher priority frequency satisfies square > Threshx, HighQ or square > Threshx, HighP during the time interval Treselection, the UE may reselect a neighboring cell with a higher priority frequency than the current cell.

In another example, when a UE desiring to perform group communication is receiving group communication through single-cell multi-transmission, the UE may consider a cell providing single-cell multi-transmission as the highest priority if a neighboring cell provides single-cell multi-transmission for group communication. Therefore, when a cell satisfies square > Threshx, HighQ or square > Threshx, HighP during the time interval Treselection, the UE may reselect a neighboring cell having a higher priority.

In yet another example, when a UE desiring to perform group communication is receiving group communication through single-cell multi-transmission, the UE may consider a priority of a cell providing single-cell multi-transmission to be the same as a priority of a current cell if a neighboring cell provides single-cell multi-transmission for group communication. Accordingly, the UE may perform cell reselection based on the rank of the cell or RSRP (reference signal received power) measurement of the cell.

In yet another example, when a UE desiring to perform group communication is receiving group communication through single-cell multi-transmission, the UE may consider a priority of a cell frequency providing single-cell multi-transmission to be the same as a current cell frequency priority if a neighboring cell provides single-cell multi-transmission for group communication. Thus, for the current cell or the frequency of the current cell, the UE may perform cell reselection based on the cell frequency class including the current cell frequency or based on RSRP measurements of the cell.

Meanwhile, in order to maintain service continuity, when the UE recognizes that the neighbor cell to which the UE wants to move does not support single cell multi-transmission through single cell multi-transmission system information on the neighbor cell, control information associated with the single cell multi-transmission system information, or control information for identifying whether the neighbor cell supports single cell multi-transmission while staying in the source cell (the current cell or the cell in which the UE camps), the UE may request service through unicast through the GCS AS. For example, an RRC-idle UE may establish an RRC connection and may then request a service through unicast through the GCS AS.

The allocation of the G-RNTI according to the present invention will be described below.

For example, the G-RNTI may be one of currently stored RNTI values FFF 4-FFFC.

In another example, the G-RNTI may be 0001-003C or 003D-FFF 3.

In yet another example, in case of allocating G-RNTI from among a plurality of values, the base station may allocate or select the G-RNTI by coordinating with the BM-SC or the GCS AS when allocating the G-RNTI for providing a specific group communication service/session/bearer. Thus, a G-RNTI may be assigned to a particular group communication service/session/bearer to prevent collisions with other base stations or other cells.

According to still another example, in case of allocating G-RNTI from a plurality of values, each base station may independently allocate G-RNTI when allocating G-RNTI for providing a specific group communication service/session/bearer, and may allocate or select G-RNTI through coordination if any conflict occurs.

According to still another example, in case of allocating G-RNTI from among a plurality of values, when G-RNTI for providing a specific group communication service/session/bearer is allocated, the base station may allocate or select the G-RNTI through coordination between the base stations. For this reason, X2 signaling may be required.

According to yet another example, in case of allocating G-RNTI from a plurality of values, the base station may calculate and allocate G-RNTI based on the associated TMGI when allocating G-RNTI for providing a specific group communication service/session/bearer. The UE may also calculate and use the G-RNTI based on a TMGI received through an application server (e.g., GCS AS or BM-SC) or pre-configured.

According to still another example, in the case where the G-RNTI is allocated from among a plurality of values, when the G-RNTI for providing the specific group communication service/session/bearer is allocated, the base station may calculate and allocate the G-RNTI based on the association identification information for identifying the specific group communication service/session/bearer. The UE may also calculate and use the G-RNTI based on this identification information for identifying a specific group communication service/session/bearer received through an application server (e.g., GCS AS or BM-SC) or pre-configured.

According to yet another example, in case of allocating G-RNTI from among a plurality of values, the base station may designate one RNTI (hereinafter, referred to as SC-RNTI) to broadcast G-RNTI single-cell multi-transmission control information including a specific group communication service/session/bearer to the UE. The UE may receive single-cell multi-transmission control information indicated on the PDCCH using the SC-RNTI on the PDSCH. Further, the UE may identify the G-RNTI associated with a particular group communication service/session/bearer through single cell multi-transmission control information.

The above-described embodiments of the present invention may be provided individually or in combination.

Accordingly, the present invention can provide continuous service through PDSCH radio resources shared between UEs in a specific group in one cell, reducing service interruption even if a cell change occurs due to movement of UEs receiving downlink multicast/group communication data.

Fig. 7 illustrates an operation of a base station according to an embodiment of the present invention.

The invention discloses a method for sending single-cell multi-transmission data by a base station, which comprises the steps of sending system information for single-cell multi-transmission in a primary cell (PCell); generating single-cell multi-transmission control information; and transmitting the single-cell multi-transmission control information to the UE in the PCell.

Referring to fig. 7, a base station may transmit system information for single-cell multi-transmission in a PCell (step S710). For example, the base station may transmit system information for single-cell multi-transmission through a PCell configured for the UE, and the UE may receive the system information for single-cell multi-transmission. For example, the base station may broadcast information on single-cell multi-transmission through system information. Specifically, the base station may broadcast the G-RNTI through system information. Alternatively, the base station may broadcast the TMGI and the G-RNTI associated with the TMGI via system information. Alternatively, the base station may broadcast identification information for identifying a downlink service/session/bearer of the group communication service/session/bearer and the G-RNTI associated with the identification information through the system information. In another example, the base station may broadcast information for receiving single cell multi-transmission control information including the G-RNTI through system information. Alternatively, the base station may broadcast information for receiving single cell multi-transmission control information including the TMGI and the G-RNTI associated with the TMGI through system information. Alternatively, the base station may broadcast, through the system information, identification information for identifying a downlink service/session/bearer of the group communication service/session/bearer and information of single cell multi transmission control information of the G-RNTI associated with the identification information.

Further, the base station may generate single-cell multi-transmission control information (step S720). The single cell multi-transmission control information may include information on a neighbor cell providing single cell multi-transmission. Alternatively, the single-cell multi-transmission control information may include information on a group communication service provided by each cell. Alternatively, the single-cell multi-transmission control information may include information on correspondence between the group communication service and the cell. For example, the single cell multi-transmission control information may include at least one of cell identification information on a neighbor cell providing single cell multi-transmission, a TMGI, and information on a neighbor cell providing single cell multi-transmission associated with the G-RNTI.

In addition, the base station may transmit single-cell multi-transmission control information to the UE in the PCell (step S730). The single-cell multi-transmission control information may be transmitted at a time scheduled by system information for single-cell multi-transmission. For example, the base station may include scheduling information (e.g., period and offset value information for receiving control information) in the system information, and may transmit the control information according to the scheduling information. The single cell multi-transmission control information may be indicated through the PDCCH. Accordingly, the UE can acquire information on a neighbor cell providing a desired group communication service. Further, the UE may identify information about neighboring cells that provide single-cell multi-transmission.

Meanwhile, the UE may identify whether a neighboring cell provides single-cell multi-transmission using the received single-cell multi-transmission control information. Alternatively, the UE may identify the type of group communication service provided by the neighboring cell. Alternatively, the UE may identify neighboring cells that provide the group communication service that the UE desires to perform. Alternatively, the UE may identify a cell that provides single-cell multi-transmission. Accordingly, although system information on the neighbor cells is not checked, the UE can recognize whether the neighbor cells provide single-cell multi-transmission or whether the neighbor cells provide a group communication service that the UE wants to perform.

The UE may assign the highest priority to the cell frequency that provides single cell multiple transmission, thereby using that frequency in the cell reselection procedure. Alternatively, the UE may assign a priority to the cell in a cell reselection procedure according to the aforementioned embodiments of assigning cell reselection priorities, and may perform the cell reselection procedure according to the priority.

Accordingly, the base station can allow the RRC-idle UE to identify whether the neighbor cell provides single cell multi-transmission through the serving cell without using system information or control information on the neighbor cell to identify whether the neighbor cell provides single cell multi-transmission. Further, the UE may assign the highest priority to a cell frequency providing single-cell multi-transmission, thereby continuously providing a group communication service even in cell reselection.

A configuration of a UE and a base station capable of performing part or all of the aforementioned operations of the present invention as needed is briefly described.

Fig. 8 shows a configuration of a UE according to still another embodiment of the present invention.

Referring to fig. 8, a UE800 receiving single-cell multi-transmission data according to the present invention includes: a receiving unit 830, configured to receive system information for single-cell multi-transmission in a primary cell and receive single-cell multi-transmission control information in the primary cell; and a control unit 810 for identifying whether the neighboring cell provides single-cell multi-transmission using the single-cell multi-transmission control information.

Further, the receiving unit 830 may receive single-cell multi-transmission control information indicated through the PDCCH. The single cell multi-transmission control information may include at least one of cell identification information on a neighbor cell providing single cell multi-transmission, a TMGI, and information on a neighbor cell providing single cell multi-transmission associated with the G-RNTI. The single cell multi-transmission control information may be scheduled by system information. In addition, the receiving unit 830 receives downlink control information, data, and messages from the base station through corresponding channels.

Further, the control unit 810 may assign the highest priority to the cell frequency providing single cell multi transmission to perform the cell reselection procedure.

Further, the control unit 810 controls the overall operation of the UE800 necessary for performing the above-described present invention when receiving downlink multicast/group communication data through the PDSCH or when receiving multicast/group communication data through the PDSCH while minimizing service interruption occurring due to movement of an RRC-idle UE from cell to cell.

Meanwhile, when the neighboring cell does not provide single-cell multi-transmission, the transmitting unit 820 may transmit request information for requesting reception of a group communication service through unicast. The request information may be sent to a serving cell, a neighboring cell, or a GCS AS. Also, the transmitting unit 820 transmits uplink control information, data, and messages to the base station through the corresponding channel.

Referring to fig. 9, a base station 900 of the present invention may include a control unit 910 configured to generate single-cell multi-transmission control information; and a transmitting unit 920 for transmitting system information for single-cell multi-transmission in the primary cell and transmitting single-cell multi-transmission control information to the UE in the primary cell.

The transmitting unit 920 may transmit single-cell multi-transmission control information through a PDCCH indication. The single cell multi-transmission control information may include at least one of cell identification information on a neighbor cell providing single cell multi-transmission, a TMGI, and information on a neighbor cell providing single cell multi-transmission associated with the G-RNTI. The single cell multi-transmission control information may be scheduled by system information.

The receiving unit 930 may receive a request for a group communication service through unicast from a UE.

The control unit 910 controls the overall operation of the base station 900 required to perform the aforementioned present invention when transmitting downlink multicast/group communication data through the PDSCH or when transmitting multicast/group communication data through the PDSCH while minimizing service interruption occurring due to the movement of RRC-idle UEs from cell to cell.

Further, the transmitting unit 920 and the receiving unit 930 are used to transmit/receive signals, messages, and data necessary to perform the aforementioned present invention to/from the UE.

The standard details or standard documents mentioned in the above embodiments have been omitted to simplify the description of the specification and constitute a part of the present specification. Therefore, when standard details and standard contents of standard documents are added to the present specification or disclosed in the claims, they should be construed as falling within the scope of the present invention.

Although the preferred embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Accordingly, the exemplary aspects of the invention are not described for limiting purposes. The scope of the invention should be construed based on the appended claims in such a manner that all technical concepts equivalent to those included in the scope of the claims belong to the invention.

Cross Reference to Related Applications

This application claims priority and benefit under 35 U.S. C. § 119(a) of korean patent application No. 10-2015-. Further, the present application claims priority of the same korean patent application in countries other than the united states, the entire contents of which are incorporated herein by reference.

Claims

1. A method for a user equipment to receive single-cell multi-transmission data, the method comprising:

receiving system information for single-cell multi-transmission in a primary cell (PCell);

receiving single-cell multi-transmission control information in the primary cell; and

using the single-cell multi-transmission control information to identify whether a neighboring cell provides single-cell multi-transmission for a group communication service of interest to the user equipment,

wherein the single-cell multi-transmission control information comprises: cell identification information on a neighbor cell providing a single-cell multi-transmission, group communication service identification information for the group communication service, and information on a neighbor cell providing a single-cell multi-transmission associated with group identification information allocated for a single-cell multi-transmission for the group communication service in a cell in which the user equipment is located; and the single-cell multi-transmission control information is scheduled by the system information.

2. The method of claim 1, wherein the single cell multiple transmission control information is indicated by a Physical Downlink Control Channel (PDCCH).

3. The method of claim 1, further comprising: requesting reception of a group communication service by unicast before a cell change when the neighbor cell does not provide single-cell multi-transmission.

4. The method of claim 1, further comprising: the cell reselection procedure is performed by assigning the highest priority to the frequency of the cell providing single cell multiple transmission.

5. The method of claim 1, wherein the group communication service identification information is a temporary mobile group identity and the group identification information is a group radio network temporary identifier.

6. A method for a base station to transmit single-cell multi-transmission data, the method comprising:

transmitting system information for single-cell multi-transmission in a primary cell (PCell);

generating single-cell multi-transmission control information; and

transmitting the single-cell multi-transmission control information to a User Equipment (UE) in the primary cell so that the user equipment can recognize whether a neighboring cell provides a single-cell multi-transmission for a group communication service in which the user equipment is interested,

7. The method of claim 6, wherein the single-cell multi-transmission control information is indicated by a Physical Downlink Control Channel (PDCCH).

8. The method of claim 6, wherein the UE uses the single cell multi-transmission control information to identify whether neighboring cells provide single cell multi-transmission.

9. The method of claim 6, wherein the UE performs a cell reselection procedure by assigning a highest priority to a frequency of a cell that provides single cell multi-transmission.

10. The method of claim 6, wherein the group communication service identification information is a temporary mobile group identity and the group identification information is a group radio network temporary identifier.

11. A User Equipment (UE) for receiving single cell multiple transmission data, the UE comprising:

a receiving unit configured to receive system information for single-cell multi-transmission in a primary cell (PCell) and receive single-cell multi-transmission control information in the primary cell; and

a control unit configured to identify whether a neighbor cell provides a single-cell multi-transmission for a group communication service of interest to the user equipment using the single-cell multi-transmission control information,

12. The UE of claim 11, wherein the single cell multiple transmission control information is indicated by a Physical Downlink Control Channel (PDCCH).

13. The UE of claim 11, further comprising a transmitting unit configured to request reception of a group communication service by unicast before a cell change when the neighboring cell does not provide single cell multi-transmission.

14. The UE of claim 11, wherein the control unit performs a cell reselection procedure by assigning a highest priority to a frequency of a cell providing single cell multi-transmission.

15. The UE of claim 11, wherein the group communication service identification information is a temporary mobile group identity and the group identification information is a group radio network temporary identifier.

16. A base station for transmitting single-cell multi-transmission data, the base station comprising:

a control unit configured to generate single-cell multi-transmission control information; and

a transmitting unit configured to transmit system information for single-cell multi-transmission in a primary cell (PCell) and transmit the single-cell multi-transmission control information to a User Equipment (UE) in the primary cell so that the user equipment can recognize whether a neighbor cell provides single-cell multi-transmission for a group communication service in which the user equipment is interested,

17. The base station of claim 16, wherein the single-cell multi-transmission control information is indicated through a Physical Downlink Control Channel (PDCCH).

18. The base station of claim 16, wherein the UE uses the single cell multi-transmission control information to identify whether neighboring cells provide single cell multi-transmission.

19. The base station of claim 16, wherein the UE performs a cell reselection procedure by assigning a highest priority to a frequency of a cell providing single cell multiple transmission.

20. The base station of claim 16, wherein the group communication service identification information is a temporary mobile group identity and the group identification information is a group radio network temporary identifier.