WO2019124437A1 - Base station, processor, and communication method - Google Patents

Base station, processor, and communication method Download PDF

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Publication number
WO2019124437A1
WO2019124437A1 PCT/JP2018/046766 JP2018046766W WO2019124437A1 WO 2019124437 A1 WO2019124437 A1 WO 2019124437A1 JP 2018046766 W JP2018046766 W JP 2018046766W WO 2019124437 A1 WO2019124437 A1 WO 2019124437A1
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Prior art keywords
target
period
base station
wireless communication
mode
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PCT/JP2018/046766
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French (fr)
Japanese (ja)
Inventor
義三 佐藤
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京セラ株式会社
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/24—Cell structures
    • H04W16/28—Cell structures using beam steering
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/12—Wireless traffic scheduling

Definitions

  • the present disclosure relates to a base station, a processor, and a communication method.
  • the base station includes a control unit configured to select a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station.
  • the control unit is configured to select, as the target device, a predetermined device in a coverage extension mode for extending cell coverage.
  • the processor is a processor for controlling a base station.
  • the processor selects a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station, and the control unit determines a coverage extension mode for extending cell coverage. And a process of selecting a device as the target device.
  • the communication method includes the step of the base station selecting a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station.
  • the base station selects, as the target device, a predetermined device in a coverage extension mode for extending the coverage of a cell.
  • FIG. 2 is a diagram showing a protocol stack in the communication system.
  • FIG. 1 is a diagram showing a configuration of a wireless communication device 100.
  • FIG. 2 shows a configuration of a base station 310. It is a figure for demonstrating the operation example 1 which concerns on embodiment. It is a figure for demonstrating the operation example 2 which concerns on embodiment. It is a figure for demonstrating the operation example 3 which concerns on embodiment.
  • LPWA low power wide area
  • a wireless communication apparatus that performs LPWA wireless communication (hereinafter referred to as an LPWA communication apparatus) achieves power saving by stopping wireless communication in a period in which no data communication occurs.
  • a wireless communication apparatus that performs wireless communication of a wireless wide area network (WWAN) method such as a smartphone, but also an LPWA communication apparatus performs communication under control of a base station. Therefore, when the base station applies beamforming to all wireless communication devices under control of the base station, the processing load on the base station may exceed the processing capacity of the base station.
  • WWAN wireless wide area network
  • the base station includes a control unit configured to select a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station.
  • the control unit is configured to select, as the target device, a predetermined device in a coverage extension mode for extending cell coverage.
  • the control unit determines whether or not the number of candidate target devices to which the beamforming should be applied in the first period exceeds the upper limit number of target devices allowed in the first period, and the candidate When the number of target devices exceeds the upper limit number, the predetermined device selected as the target device among the candidate target devices is a wireless resource in a second period after the first period. It may be configured to change to an assignment target of
  • the control unit may be configured to determine whether the number of target devices exceeds the upper limit number after performing allocation of radio resources in the first period.
  • the control unit may allocate the radio resource in the first period allocated to the predetermined device changed to the allocation target of the radio resource in the second period to the non-target device to which the beamforming is not applied. It may be configured.
  • the control unit allocates a wireless resource in a first period to a wireless communication device
  • the number of target devices to which the wireless resource is assigned is the upper limit number of target devices allowed in the first period. If the number of target devices has reached the upper limit number, then unassigned radio resources among the radio resources in the first period are not targeted for the beamforming not being applied. It may be configured to be assigned to a device.
  • the control unit may be configured to assign a radio resource in a first period to the target device before the non-target device to which the beamforming is not applied.
  • the processor is a processor for controlling a base station.
  • the processor selects a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station, and the control unit determines a coverage extension mode for extending cell coverage. And a process of selecting a device as the target device.
  • the communication method includes the step of the base station selecting a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station.
  • the base station selects, as the target device, a predetermined device in a coverage extension mode for extending the coverage of a cell.
  • FIG. 1 is a diagram showing an example of the configuration of the communication system 1 according to the embodiment.
  • the communication system 1 includes a wireless communication device 100, a host device 200, and a wireless communication network 300.
  • the communication system 1 may include a WWAN communication apparatus that performs WWAN wireless communication.
  • the wireless communication device 100 is a communication device that performs wireless communication.
  • the wireless communication device 100 may be referred to as a user equipment (UE: User Equipment).
  • UE User Equipment
  • the wireless communication device 100 is also described as an LPWA communication device 100.
  • the LPWA communication apparatus 100 may be, for example, a user apparatus having one of the categories M1 and M2.
  • the WWAN communication apparatus may be, for example, a user apparatus having a category of category 0 or more (eg, any of categories 1-12, any of DL categories 6-17, etc.).
  • the WWAN communication apparatus performs WWAN wireless communication with the wireless communication network 300.
  • the LPWA communication apparatus 100 performs LPWA wireless communication with the wireless communication network 300.
  • the LPWA method is a wireless communication method that realizes long-distance communication while reducing power consumption.
  • an enhanced machine type communication (eMTC) method or an NB (Narrow Band) -IoT method defined in the 3GPP standard which is one of cellular communication standards is used as the LPWA method.
  • the eMTC may be referred to as an LTE category M1 (above category M1).
  • NB-IoT may be referred to as LTE category NB1.
  • the eMTC system or the NB-IoT system limits the frequency bandwidth used for wireless communication to a narrow bandwidth in order to reduce the cost of the communication apparatus. Note that the frequency bandwidth available for NB-IoT wireless communication is narrower than the frequency bandwidth available for eMTC wireless communication.
  • the LPWA communication apparatus 100 may be installed outside the coverage of the normal area of the wireless communication network 300, for example, underground. Therefore, in both the eMTC method and the NB-IoT LPWA method, a coverage extension technique is used which extends the coverage by repeatedly transmitting the same signal.
  • the LPWA communication apparatus 100 achieves power saving by stopping wireless communication in a period in which no data communication occurs.
  • power saving techniques there are eDRX (extended discontinuous reception) and PSM (power saving mode) defined in the 3GPP standard.
  • eDRX extends the DRX cycle, which is the reception interval when the LPWA communication device 100 performs intermittent reception, thereby extending the period (off period) in which the LPWA communication device 100 turns the receiver off, thereby saving power. It will be realized.
  • PSM realizes power saving by setting the LPWA communication apparatus 100 in a pseudo power-off state (PSM state) in which even intermittent reception is not performed.
  • PSM state pseudo power-off state
  • the off period and the PSM state in the eDRX are collectively referred to as a “power saving state”.
  • the LPWA communication apparatus 100 in an idle state which is in a standby state, can notice paging which is a call from the wireless communication network 300.
  • PSM Packet Control Protocol
  • the LPWA communication apparatus 100 in the PSM state can not notice paging from the wireless communication network 300.
  • the wireless communication network 300 knows whether the LPWA communication apparatus 100 is in the power saving state, and stores data addressed to the LPWA communication apparatus 100 while the LPWA communication apparatus 100 is in the power saving state.
  • the LPWA communication apparatus 100 is connected to the host device 200. Specifically, the LPWA communication apparatus 100 is directly connected to the host device 200 or indirectly connected to the host device 200 via a cable.
  • the LPWA communication apparatus 100 performs wired communication with, for example, a Universal Asynchronous Receiver / Transmitter (UART) method or a Universal Serial Bus (USB) method with the host device 200.
  • UART Universal Asynchronous Receiver / Transmitter
  • USB Universal Serial Bus
  • the LPWA communication apparatus 100 may not be connected to the host device 200.
  • the LPWA communication apparatus 100 may be a wireless communication apparatus independent of the host device 200, such as a wireless communication apparatus that performs wireless communication of the WWAN (Wireless Wide Area Network) method.
  • WWAN Wireless Wide Area Network
  • the host device 200 is a personal computer (PC), a sensor device, a meter device, a vending machine, or the like.
  • the host device 200 executes an application for IoT.
  • the host device 200 to which the LPWA communication apparatus 100 is connected can communicate with the wireless communication network 300 via the LPWA communication apparatus 100 even if the host apparatus 200 itself does not have the wireless communication function.
  • the wireless communication network 300 is a network managed by a telecommunications carrier.
  • the wireless communication network 300 has a configuration in accordance with the 3GPP standard.
  • the wireless communication network 300 includes a base station 310, an MME (Mobility Management Entity) 320, and a GW (Gateway) 330.
  • MME Mobility Management Entity
  • GW Gateway
  • the base station 310 performs LPWA wireless communication with the LPWA communication apparatus 100.
  • the base station 310 is connected to the MME 320 and the GW 330.
  • the MME 320 communicates with the LPWA communication apparatus 100 using NAS (Non-Access Stratum) signaling via the base station 310 to thereby establish a tracking area (ie, an area unit to perform paging) in which the LPWA communication apparatus 100 is located. to manage.
  • the MME 320 also determines whether the LPWA communication apparatus 100 is in a power saving state.
  • the GW 330 includes a PDN-GW (Packet Data Network Gateway) and an S-GW (Serving Gateway).
  • the PDN-GW functions as an interface between the wireless communication network 300 and an external network (eg, the Internet).
  • the S-GW performs data transfer control between the PDN-GW and the base station 310.
  • the GW 330 cooperates with the MME 320, and accumulates data addressed to the LPWA communication apparatus 100 while the LPWA communication apparatus 100 is in the power saving state. When the LPWA communication apparatus 100 recovers from the power saving state, the GW 330 transfers data addressed to the LPWA communication apparatus 100 to the LPWA communication apparatus 100 via the eNB 200.
  • FIG. 2 is a diagram showing a protocol stack in the communication system 1 according to the embodiment. Here, the flow of processing of data from the external network (external server) to the LPWA communication device 100 / host device 200 will be described.
  • the external server generates data in the application layer.
  • Data generated in the application layer is encrypted by SSL (Secure Sockets Layer), processed in the transport layer (UDP or TCP) and IP layer, and then transmitted to the wireless communication network 300 by wired communication such as Ethernet. Be done.
  • SSL Secure Sockets Layer
  • UDP transport layer
  • IP IP layer
  • the wireless communication network 300 receives data from the wireless communication network 300 by wired communication such as Ethernet (registered trademark), is subjected to routing processing and the like in IP layer and IP address management, and receives LPWA via the wireless layer of the base station 310. It is transmitted to the communication device 100.
  • the radio layer has a configuration conforming to the 3GPP standard, and includes a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, and an RRC (Radio). Resource Control) layer.
  • the LPWA communication apparatus 100 receives data from the wireless communication network 300 via wireless layer and IP address management by wired communication such as Ethernet (registered trademark).
  • the LPWA communication apparatus 100 has an IP layer, a transport layer (UDP or TCP), and SSL.
  • the IP layer receives data in the form of IP packets via the wireless layer and IP address management, processes the received data in the transport layer (UDP or TCP), and performs decryption (decryption) by SSL.
  • the LPWA communication apparatus 100 transmits the decrypted data to the host device 200 via the USB or the UART.
  • the host device 200 processes the data received from the LPWA communication apparatus 100 via the USB or UART by the application layer.
  • FIG. 3 is a diagram showing the configuration of the wireless communication apparatus 100. As shown in FIG.
  • the configuration of the wireless communication apparatus 100 will be described by taking the LPWA communication apparatus 100 as an example.
  • the WWAN communication apparatus performs wireless communication with the wireless communication network 300 by the WWAN wireless communication method.
  • the LPWA communication apparatus 100 includes an antenna 110, a front end unit 120, a processor 130, a memory 140, and a power management unit 150.
  • the host device 200, a User Identity Module (UIM) / Subscriber Identity Module (SIM) 160, and a sensor 170 can be connected to the LPWA communication apparatus 100 via an interface (not shown).
  • the UIM / SIM 160 stores subscriber information and the like necessary for wireless communication with the wireless communication network 300.
  • the sensor 170 measures, for example, temperature, humidity, barometric pressure, illuminance, acceleration, geomagnetism, and the like, and outputs a measured value.
  • the LPWA communication apparatus 100 may further include a Global Navigation Satellite System (GNSS) receiver (for example, a Global Positioning System (GPS) receiver).
  • GNSS Global Navigation Satellite System
  • GPS Global Positioning System
  • the antenna 110 is used to transmit and receive a radio signal.
  • the front end unit 120 performs amplification processing, filter processing, and the like on the radio signal received by the antenna 110, converts the radio signal into a baseband signal, and outputs the baseband signal to the processor 130. Further, the front end unit 120 converts the baseband signal input from the processor 130 into a wireless signal, performs amplification processing and the like, and outputs the signal to the antenna 110.
  • the processor 130 performs various processing and control in the LPWA communication apparatus 100.
  • the memory 140 includes volatile memory and non-volatile memory, and stores programs executed by the processor 130 and information used for processing by the processor 130.
  • Power management unit 150 includes a battery and its peripheral circuits.
  • the power management unit 150 supplies drive power to the LPWA communication apparatus 100.
  • drive power may be supplied from the host device 200 by USB power feeding.
  • the processor 130 performs wireless communication with the wireless communication network 300 by the LPWA method.
  • the processor 130 receives data transmitted using the UDP from the wireless communication network 300.
  • the processor 130 can transfer the received data addressed to the host device 200 to the host device 200.
  • the front end unit 120 and the processor 130 shift to a power saving state in which wireless communication is stopped in a period in which no data communication occurs. Since power supply to the front end unit 120 and the like can be stopped in the power saving state, power saving of the LPWA communication apparatus 100 can be realized.
  • the front end unit 120 and the processor 130 resume wireless communication after a predetermined time has elapsed since the transition to the power saving state.
  • the predetermined time may be determined by the DRX cycle or may be determined by a timer value for PSM.
  • the timer values for the DRX cycle and the PSM are information shared by the LPWA communication apparatus 100 and the MME 320.
  • the processor 130 resumes wireless communication after a predetermined time has elapsed, and then receives data stored in the wireless communication network 300 (GW 330) while in the power saving state.
  • the LPWA communication apparatus 100 executes the process executed by at least one of the antenna 110, the front end unit 120, the processor 130, the memory 140, and the power management unit 150 included in the LPWA communication apparatus 100. Description will be made as processing (operation).
  • FIG. 4 shows the configuration of base station 310. As shown in FIG. 4
  • the base station 310 includes antenna (s) 311, a front end unit 312, a processor 313, a memory 314, and a power management unit 315.
  • the antenna (s) 311 are used to transmit and receive wireless signals.
  • the front end unit 312 performs amplification processing, filter processing, and the like on the wireless signal received by the antenna 311, converts the wireless signal into a baseband signal, and outputs the baseband signal to the processor 313. Further, the front end unit 312 converts the baseband signal input from the processor 313 into a wireless signal, performs amplification processing and the like, and outputs the result to the antenna 311.
  • the processor 313 performs various processing and control in the base station 310.
  • the processor 313 performs wireless communication with the LPWA communication apparatus 100 by the LPWA method.
  • the processor 130 receives, from the LPWA communication apparatus 100, data to be transmitted using UDP.
  • the processor 313 is connected to a network node (for example, the MME 320) in the wireless communication network 300 via a backhaul and communicates with the network node.
  • the memory 314 includes volatile memory and non-volatile memory, and stores programs executed by the processor 313 and information used for processing by the processor 313.
  • the power management unit 315 includes a battery and its peripheral circuits.
  • the power management unit 315 supplies drive power to the base station 310.
  • the power management unit 315 may be externally supplied with drive power.
  • the base station 310 executes processing performed by at least one of the antenna (s) 311, the front end unit 312, the processor 313, the memory 314, and the power management unit 315 that the base station 310 comprises.
  • the process (operation) will be described.
  • the wireless communication device 100 and the WWAN communication device will be referred to as a UE 100
  • the base station 310 will be referred to as a BS 310.
  • CE mode The CE (Coverage Enhancement) mode will be described.
  • the CE mode is a mode introduced to extend cell coverage.
  • the CE mode is defined to enhance the connectivity of the UE 100 in a cell edge where the radio environment is bad.
  • the CE mode includes, for example, mode A and mode B.
  • the difference between the mode A and the mode B is, for example, the number of transmission repetitions and the presence or absence of CQI (Channel Quality Indicator) feedback.
  • the number of transmission repetitions is larger than that of the mode A UE 100.
  • the number of transmission repetitions is, for example, 2048 at maximum.
  • CQI feedback is performed, whereas in mode B, CQI feedback is not performed.
  • Mode B may be applied to the stationary UE 100.
  • the UE 100 determines whether to apply the CE mode (that is, whether to transition to the CE mode) according to the reception strength of the reference signal from the BS 310.
  • the UE (CE mode UE) 100 to which the CE mode is applied can be considered to be within the extended coverage.
  • the UE 100 in CE mode can access a cell using the extended coverage function.
  • the UE 100 may be able to access the cell, for example, only when a cell's MIB (Master Information Block) indicates that scheduling information for SIB 1 for a BL reduced to UE (Bandwidth reduced low complexity UE) is scheduled. .
  • MIB Master Information Block
  • the BS 310 may provide, for example, a set of Physical Random Access Channel (PRACH) resources (eg, time-frequency resources, preambles, etc.) associated with the extended coverage level, for example, in a System Information Block (SIB).
  • PRACH Physical Random Access Channel
  • SIB System Information Block
  • the BS 310 may provide, for example, the number of PRACH repetitions per extended coverage level and the number of maximum preamble transmission attempts.
  • UEs 100 within the same enhanced coverage level use random access resources associated with the same enhanced coverage level. Therefore, based on the set of PRACH resources used by the UE 100 to transmit the PRACH, the BS 310 determines whether the UE 100 applies the CE mode (ie, whether the UE 100 is the CE mode UE) Or not) can be determined.
  • CE mode ie, whether the UE 100 is the CE mode UE
  • the management of the CE list will be described.
  • the BS 310 manages the CE list in order to grasp whether the UE 100 under the control of the BS 310 is in the CE mode.
  • the BS 310 can generate, update, and delete the CE list as needed.
  • the CE list includes at least an identifier of the UE 100 in CE mode (for example, C-RNTI (Cell-Radio. Network Temporary Identifier), IMSI (International Mobile Subscriber Identity), IMEI (International Mobile Equipment Identifier), MEID (Mobile Equipment Identifier)). It may be a list of any).
  • the BS 310 may add the identifier of the UE 100 to the CE list when the UE 100 transitions from the normal mode to the CE mode (or the UE 100 is in the CE mode).
  • the BS 310 may delete the identifier of the UE 100 from the CE list, when the UE 100 transitions from the CE mode to the normal mode (the CE mode is not a CE mode).
  • the CE list may indicate whether the UE 100 is in the CE mode. That is, in the CE list, information indicating whether or not the UE 100 is in the CE mode (normal mode / CE mode) may be associated with the identifier of the UE 100. Thus, the BS 310 can determine whether the UE 100 is in the CE mode. The BS 310 updates the CE list in response to the change of the mode (normal mode / CE mode) of the UE 100.
  • information indicating which CE mode the UE 100 is in (mode A / mode B) may be associated with the identifier of the UE 100.
  • information indicating which extended coverage level the UE 100 is at may be associated with the identifier of the UE 100.
  • terminal information of the UE 100 may be associated with an identifier of the UE 100.
  • the terminal information of the UE 100 is information indicating that it is a UE (for example, an LPWA terminal, an MTC (Machine Type Communication) terminal, etc.) that allows a data delay than the normal UE 100 (that is, the UE 100 in the normal mode).
  • the terminal information is, for example, at least one of UE capability information and UE category information.
  • information indicating whether or not beamforming can be applied to the UE 100 may be associated with the identifier of the UE 100.
  • the BS 310 may determine that the UE 100 that has received information (for example, a reference signal (SRS (Sounding Reference Signal)) or feedback information) used to direct a beam to the UE 100 can apply beamforming.
  • the BS 310 may determine that the UE 100 that has not received the information is the UE 100 to which beamforming can not be applied.
  • the BS 310 may determine that the UE 100 to which a radio resource for transmitting the information has been allocated can apply beamforming.
  • the BS 310 may determine that the UE 100 to which the radio resource for transmitting feedback information is not assigned is the UE 100 to which beamforming is not applied.
  • the feedback information is, for example, channel state information (CSI: Channel State Information).
  • CSI Channel State Information
  • the UE 100 can generate CSI based on a reference signal (CSI-RS) from the BS 310.
  • CSI-RS reference signal
  • CSI may include PMI (Precoding Matrix Indicator) and RI (Rank Indicator).
  • PMI is information indicating a precoder matrix preferable for use in downlink.
  • PMI is information indicating a precoder matrix in which the beam is directed to the UE 100 that is the transmission source of the PMI.
  • the UE 100 selects a PMI to be fed back to the BS 310 such that its reception condition is improved.
  • RI indicates a preferred rank for use in downlink. For example, the UE 100 selects an RI to be fed back to the BS 310 such that a rank appropriate to its reception state is applied.
  • the BS 310 may perform an operation to estimate a channel between the UE 100 and the BS 310 based on the feedback information.
  • the BS 310 may perform an operation for generating a transmission precoding weight based on the calculated propagation path.
  • the BS 310 can control beamforming based on the generated transmission precoding weights.
  • the BS 310 may generate transmission precoding weights using CSI generated based on SRS.
  • the BS 310 can determine whether the UE 100 is in the CE mode, for example, by the following method, in order to update the CE mode.
  • the BS 310 can make a determination based on the PRACH signal from the UE 100.
  • the BS 310 receives the PRACH signal transmitted using the set of RACH resources for the CE mode, the BS 310 determines that the UE 100 of the transmission source is in the CE mode. If not, the transmission source UE 100 determines that it is in the normal mode (not in the CE mode).
  • the BS 310 can make the determination based on the measurement report from the UE 100.
  • the BS 310 determines that the UE 100 is in the CE mode when the reception strength of the reference signal from (the cell managed by) the BS 310 included in the measurement report is less than the threshold. Otherwise, the UE 100 determines that it is in the normal mode.
  • the BS 310 can make a determination based on information from the BS 310 (source BS) of the handover source of the UE 100.
  • the BS 310 determines that the UE 100 is in the CE mode when the information indicating that the UE 100 is in the CE mode is received from the source BS. Otherwise, the UE 100 determines that it is in the normal mode.
  • the BS 310 determines that the UE 100 is in the CE mode.
  • a message for changing from the CE mode to the normal mode for example, an RRC reconfiguration message
  • the BS 310 determines that the UE 100 is in the normal mode.
  • FIG. 5 is a diagram for explaining an operation example 1 according to the embodiment.
  • step S110 the BS 310 schedules transmission data to each UE 100 in a first period.
  • the BS 310 In response to reception of transmission data to each UE 100 from the network, the BS 310 allocates, to each UE 100, a radio resource (time / frequency resource) for transmitting the transmission data.
  • the BS 310 can perform general radio resource scheduling.
  • the first period is, for example, a period during which the BS 310 can schedule at one time.
  • the first period may be one transmission opportunity.
  • the first period may be, for example, one radio frame, one subframe, or one slot.
  • the radio frame is composed of ten subframes aligned in the time direction.
  • Each subframe is composed of two slots aligned in the time direction.
  • the length of each subframe is 1 ms.
  • the length of each slot is 0.5 ms.
  • the scheduling in step S110 is tentative scheduling. As described later, there is a possibility that a radio resource assigned to one UE 100 is assigned to another UE 100.
  • the BS 310 selects (determines) a UE to which beamforming is applied (hereinafter, appropriately referred to as a BF target UE) from among a plurality of UEs 100 to which radio resources are allocated.
  • the BS 310 selects the UE 100 in the CE mode (predetermined UE 100) as a BF target UE.
  • the BS 310 selects the BF target UE based on the CE list. For example, when the identifier of the UE 100 to which the radio resource is allocated is included in the CE list, the BS 310 selects the UE 100 as a BF target UE.
  • the BS 310 may preferentially select the UE 100 in the CE mode as a BF target UE. For example, after selecting the UE 100 in the CE mode as the BF target UE, the BS 310 may determine whether to select the normal mode UE 100 as the BF target UE. The BS 310 may select the BF target UEs such that the number of UEs 100 in CE mode is greater than the number of UEs 100 in normal mode. The BS 310 may select the BF target UE using an algorithm for making the UE 100 in the CE mode easier to select as the BF target UE than the UE 100 in the normal mode.
  • the UE 100 selected as the BF target UE is a candidate BF target UE to which beamforming should be applied in the first period. As described later, candidate BF targets UE may not have beamforming applied in the first period.
  • step S130 the BS 310 determines whether or not the number of candidate BF target UEs exceeds the upper limit number (the allowable number of UEs) of the BF target UEs permitted in the first period.
  • the allowable number of UEs may be determined in advance according to, for example, the processing capability (CPU: Central Processing Unit) of the BS 310. It may be determined in advance according to the amount of radio resources used to transmit information (SRS, feedback information, etc.) used to direct the beam to the UE 100.
  • CPU Central Processing Unit
  • the BS 310 may determine whether the number of BF target UEs exceeds the number of allowable UEs. By this means, if the number of BF target UEs does not exceed the allowable number of UEs, the BS 310 can execute scheduling appropriately, since it is the same scheduling as normal scheduling (for example, scheduling with priority control).
  • the BS 310 executes the process of step S140 when the number of candidate BF target UEs exceeds the allowable number of UEs. If not, the BS 310 ends the process. That is, BS 310 performs communication with each UE 100 using the scheduling determined in step S110. The BS 310 applies beamforming to all UEs 100 selected as BF target UEs.
  • step S140 the BS 310 wirelessly transmits the UE 100 (predetermined UE 100) in the CE mode among the candidate BF target UEs in a second period (for example, a period subsequent to the first period) after the first period. Change to resource allocation target.
  • the BS 310 selects, for example, a number (or a number equal to or greater than the difference) of predetermined UEs 100 equal to the difference between the number of candidate BF target UEs and the number of allowable UEs.
  • the BS 310 changes the selected predetermined UE 100 to a radio resource allocation target in the second period.
  • the BS 310 may select a predetermined UE 100 for which the change of the radio resource allocation target is the first time.
  • the BS 310 may select in order from a predetermined UE 100 with a smaller number of changes of radio resource allocation targets.
  • the BS 310 may select the predetermined UE 100 according to the priority of the information to be transmitted.
  • the BS 310 may select a predetermined UE 100 in which the priority of the information to be transmitted is low.
  • the BS 310 may select the predetermined UE 100 based on the CE list. For example, the BS 310 may select a predetermined UE 100 of CE mode B based on the CE list (CE mode A / CE mode B). Since the UE 100 in CE mode B is applied to the stationary UE 100, the accuracy of the beam is enhanced, and the reception quality of the UE 100 can be improved.
  • the BS 310 may select the LPWA communication apparatus 100 instead of the WWAN communication apparatus based on the CE list (terminal information of the UE 100). Since the LPWA communication apparatus 100 is likely to tolerate the delay of the transmission information, as will be described later, even if the LPWA communication apparatus 100 is selected as a target of radio resource allocation in the second period, a problem occurs. do not do.
  • step S150 the BS 310 does not apply beamforming to a radio resource (free resource) in the first period allocated to the predetermined UE 100 changed to the allocation target of the radio resource in the second period. Assign to the target UE).
  • the radio resource allocated to the selected predetermined UE 100 is generated as a vacant resource. This makes it possible to use wireless resources effectively.
  • the BS 310 can perform scheduling to allocate radio resources to non-BF target UEs until the free resource area is filled.
  • the BS 310 may allocate radio resources from the UE 100 having high priority of information to be transmitted among non-BF target UEs.
  • the BS 310 completes the scheduling in the first period as the process ends.
  • the BS 310 transmits information to each UE 100 in a first period based on scheduling.
  • the BS 310 can perform scheduling in the second period following the first period as described above.
  • the BS 310 selects the UE 100 in the CE mode as the BF target UE.
  • the UE 100 in the CE mode has a worse reception environment than the UE 100 existing in the coverage of a normal cell.
  • the BS 310 can reduce the processing load of the BS 310 and improve the reception quality of the UE 100 in the CE mode by selecting the UE 100 in the CE mode as a BF target UE among the plurality of UEs 100 under the control of the BS 310 .
  • the BS 310 changes the UE 100 in the CE mode to an allocation target of radio resources in the second period. That is, BS 310 shifts the transmission timing to UE 100 in the CE mode to the next transmission opportunity.
  • the BF 310 can select the UE 100 in the CE mode as the BF target UE as much as possible by performing processing in order by the number of UEs 100 to which beamforming can be applied.
  • BS 310 beams all UEs 100 in CE mode in a plurality of periods even if beamforming can not be applied to UEs 100 in all CE modes in the first period due to the processing capacity of BS 310. By applying the forming, it is possible to improve the reception quality of the UE 100 in the CE mode.
  • the BS 310 can select the UE 100 in many CE modes as the BF target UE.
  • the BS 310 may not be able to select the UE 100 as the transmission destination of the transmission information as the allocation target of the radio resource in the next period, when holding transmission information whose delay in the case of shifting to the next transmission opportunity is not acceptable. .
  • FIG. 6 is a diagram for explaining an operation example 2 according to the embodiment. The same parts as those described above will not be described.
  • the BS 310 determines whether the number of UEs 100 to which the radio resource is allocated has reached the allowable number of UEs.
  • step S210 the BS 310 performs scheduling for one UE 100 in a first period.
  • the BS 310 may allocate radio resources in the first period to the UE 100 in order of priority. That is, BS 310 may execute scheduling to UE 100 with the highest priority among UEs 100 for which scheduling has not been performed. Specifically, the BS 310 allocates radio resources to the UE 100. The BS 310 may determine whether to select the UE 100 as a BF target UE. Alternatively, the BS 310 may pre-select the BF target UE in the first period before performing scheduling.
  • step S220 the BS 310 determines whether there is a radio resource to be allocated in the first period.
  • the BS 310 executes the process of step S230. Therefore, the BS 310 executes the process of step S230 when the use of all radio resources in the first period is completed (when there is no available radio resource in the first period). Otherwise, the BS 310 ends the scheduling process in the first period.
  • step S230 the BS 310 determines whether the number of BF target UEs to which radio resources are allocated in the first period has reached the allowable number of UEs.
  • step S210 If the UE 100 scheduled in step S210 is a BF target UE, the BS 310 adds 1 to the number of BF target UEs to which radio resources are allocated in the first period, and reaches the allowable number of UEs. Determine if When the UE 100 that has performed scheduling in step S210 is not a BF target UE, the process of step S210 may be performed without performing the process of step S230.
  • the BS 310 executes the process of step S240. If the number of BF target UEs to which radio resources have been allocated in the first period has not reached the allowable number of UEs, the BS 310 executes the process of step S210.
  • step S240 when the number of BF target UEs has reached the allowable number of UEs, the BS 310 allocates an unassigned radio resource (vacant resource) among the radio resources in the first period to the non-BF target UE. This makes it possible to use wireless resources effectively.
  • the BS 310 may perform scheduling for the highest priority UE 100 among non-BF target UEs.
  • the BS 310 may select a non-BF target UE from among the UEs 100 for which scheduling has not been performed.
  • Step S250 is the same process as step S220.
  • the BS 310 every time the BS 310 allocates radio resources in the first period, it determines whether the number of BF target UEs allocated radio resources in the first period has reached the allowable number of UEs. By this means, if the number of BF target UEs does not exceed the allowable number of UEs, the BS 310 can execute scheduling appropriately, since it is the same scheduling as normal scheduling (for example, scheduling with priority control). Furthermore, since the allocation target of the radio resource is not changed, it is possible to reduce the scheduling process that may be wasted.
  • FIG. 7 is a diagram for explaining an operation example 3 according to the embodiment. The same parts as those described above will not be described.
  • the BS 310 schedules BF target UEs preferentially to non-BF target UEs.
  • the BS 310 selects (determines) a BF target UE from the UEs 100 to which scheduling (to allocate a radio resource) is to be performed in the first period.
  • the BS 310 may select multiple BF target UEs.
  • the BS 310 may select one BF target UE.
  • step S320 the BS 310 performs scheduling for one UE 100 in a first period from among the selected BF target UEs. Therefore, the BS 310 allocates the radio resource in the first period to the BF target UE earlier than the non-BF target UE. Thus, beamforming can be applied more reliably to the BF target UE.
  • the BS 310 may allocate radio resources in the first period to the BF target UE in order of priority. That is, BS310 may perform scheduling to UE100 with the highest priority among BF target UEs to which radio resources are not allocated.
  • Step S330 corresponds to step S210.
  • step S340 the BS 310 determines whether radio resources have been allocated to all the BF target UEs. When the BS 310 assigns radio resources to all the BF target UEs, the BS 310 executes the process of step S360. If there is a BF target UE to which no radio resource has been allocated, the BS 310 executes the process of step S350.
  • Step S350 corresponds to step S230.
  • the BS 310 executes the process of step S360. If the number of BF target UEs to which radio resources are allocated in the first period has not reached the allowable number of UEs, the BS 310 executes the process of step S320.
  • Step S360 corresponds to step S150.
  • the BS 310 allocates the radio resource in the first period to the BF target UE earlier than the non-BF target UE.
  • beamforming can be applied more reliably to the BF target UE.
  • the BS 310 may determine whether the number of BF target UEs exceeds the allowable number of UEs, before performing radio resource allocation in the first period. For example, after determining the candidate UEs 100 of the allocation of radio resources in the first period, the BS 310 may determine whether the number of BF target UEs exceeds the allowable number of UEs. Thereby, when the number of BF target UEs exceeds the number of allowable UEs, the BS 310 changes the UE 100 to which the radio resources have been allocated in the first period to the allocation target of the radio resources in the second period. Since it can be suppressed, processing that may be wasted can be reduced.
  • the BS 310 may select (determine) the BF target UE from the UEs 100 to be scheduled in the first period so that the number of BF target UEs does not exceed the allowable number of UEs.
  • the BS 310 may select one of the scheduling methods of the operation example 1-3.
  • the BS 310 may select a scheduling method according to the number of BF target UEs. For example, the BS 310 may determine whether the number of BF target UEs exceeds the allowable number of UEs in the first period before performing radio resource allocation in the first period.
  • the BS 310 may select the scheduling method according to the operation example 1 or 3 when the number of BF target UEs does not exceed the allowable number of UEs.
  • the BS 310 may select the scheduling method according to the operation example 2 when the number of BF target UEs exceeds the allowable number of UEs.
  • the BS 310 may select a scheduling method according to the number of UEs in CE mode and the number of LPWA communication devices 100.
  • the LPWA method is the eMTC method or the NB-IoT method has been described, but an LPWA method other than the eMTC method and the NB-IoT method may be used.

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Abstract

A base station according to one embodiment comprises a control unit that is constituted so as to select, from among a plurality of wireless communication devices under control of the base station, a designated device on which beam forming is applied. The control unit is constituted so as to select a prescribed device in a coverage extension mode for extending the coverage of a cell as the target device.

Description

基地局、プロセッサ、及び通信方法Base station, processor, and communication method
　本開示は、基地局、プロセッサ、及び通信方法に関する。 The present disclosure relates to a base station, a processor, and a communication method.
　従来、基地局が、無線通信装置に対して指向性を有するビームを向ける技術（ビームフォーミング）が広く知られている（例えば、特許文献１参照）。これにより、無線通信装置の通信品質が改善すると共に、他の無線通信装置への干渉を低減することができる。 Conventionally, a technique (beam forming) in which a base station directs a beam having directivity to a wireless communication apparatus is widely known (see, for example, Patent Document 1). As a result, the communication quality of the wireless communication device can be improved, and interference with other wireless communication devices can be reduced.
　特開２０１７－１５７９２０号公報 JP, 2017-157920, A
　一の実施形態に係る基地局は、前記基地局の制御下における複数の無線通信装置の中からビームフォーミングが適用される対象装置を選択するよう構成される制御部を備える。前記制御部は、セルのカバレッジを拡張するためのカバレッジ拡張モードの所定装置を前記対象装置として選択するよう構成される。 The base station according to one embodiment includes a control unit configured to select a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station. The control unit is configured to select, as the target device, a predetermined device in a coverage extension mode for extending cell coverage.
　一の実施形態に係るプロセッサは、基地局を制御するためのプロセッサである。前記プロセッサは、前記基地局の制御下における複数の無線通信装置の中からビームフォーミングが適用される対象装置を選択する処理と、制御部は、セルのカバレッジを拡張するためのカバレッジ拡張モードの所定装置を前記対象装置として選択する処理と、を実行する。 The processor according to one embodiment is a processor for controlling a base station. The processor selects a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station, and the control unit determines a coverage extension mode for extending cell coverage. And a process of selecting a device as the target device.
　一の実施形態に係る通信方法は、基地局は、前記基地局の制御下における複数の無線通信装置の中からビームフォーミングが適用される対象装置を選択するステップを備える。前記選択するステップにおいて、前記基地局は、セルのカバレッジを拡張するためのカバレッジ拡張モードの所定装置を前記対象装置として選択する。 The communication method according to one embodiment includes the step of the base station selecting a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station. In the selecting step, the base station selects, as the target device, a predetermined device in a coverage extension mode for extending the coverage of a cell.
通信システムの構成の一例を示す図である。It is a figure which shows an example of a structure of a communication system. 通信システムにおけるプロトコルスタックを示す図である。FIG. 2 is a diagram showing a protocol stack in the communication system. 無線通信装置１００の構成を示す図である。FIG. 1 is a diagram showing a configuration of a wireless communication device 100. 基地局３１０の構成を示す図である。FIG. 2 shows a configuration of a base station 310. 実施形態に係る動作例１を説明するための図である。It is a figure for demonstrating the operation example 1 which concerns on embodiment. 実施形態に係る動作例２を説明するための図である。It is a figure for demonstrating the operation example 2 which concerns on embodiment. 実施形態に係る動作例３を説明するための図である。It is a figure for demonstrating the operation example 3 which concerns on embodiment.
　［実施形態の概要］
　ＩｏＴ（Ｉｎｔｅｒｎｅｔ　ｏｆ　Ｔｈｉｎｇｓ）の普及に伴い、低消費電力かつ低コストの無線通信装置の需要が高まっている。このような需要に応えるために、消費電力を抑えつつ遠距離通信を実現する無線通信の方式であるＬＰＷＡ（Ｌｏｗ　Ｐｏｗｅｒ　Ｗｉｄｅ　Ａｒｅａ）が注目されている。ＬＰＷＡ方式の無線通信を行う無線通信装置（以下、ＬＰＷＡ通信装置と称する）は、データ通信が発生しない期間において無線通信を停止することによって省電力化を実現している。 [Overview of the embodiment]
With the spread of the Internet of Things (IoT), the demand for low power consumption and low cost wireless communication devices is increasing. In order to meet such demand, a low power wide area (LPWA), which is a wireless communication system that realizes long-distance communication while suppressing power consumption, has attracted attention. A wireless communication apparatus that performs LPWA wireless communication (hereinafter referred to as an LPWA communication apparatus) achieves power saving by stopping wireless communication in a period in which no data communication occurs.
　このＩｏＴ（Ｉｎｔｅｒｎｅｔ　ｏｆ　Ｔｈｉｎｇｓ）の普及に伴って、ＬＰＷＡ装置の数が今後も増加することが想定される。 With the spread of the Internet of Things (IoT), it is expected that the number of LPWA devices will continue to increase.
　スマートフォンなどのＷＷＡＮ（Ｗｉｒｅｌｅｓｓ　Ｗｉｄｅ　Ａｒｅａ　Ｎｅｔｗｏｒｋ）方式の無線通信を行う無線通信装置だけでなく、ＬＰＷＡ通信装置も基地局の制御下で通信を行う。従って、基地局が、基地局の制御下の全ての無線通信装置に対して、ビームフォーミングが適用された場合、基地局の処理負荷が基地局の処理能力を超えるおそれがある。 Not only a wireless communication apparatus that performs wireless communication of a wireless wide area network (WWAN) method such as a smartphone, but also an LPWA communication apparatus performs communication under control of a base station. Therefore, when the base station applies beamforming to all wireless communication devices under control of the base station, the processing load on the base station may exceed the processing capacity of the base station.
　一の実施形態に係る基地局は、前記基地局の制御下における複数の無線通信装置の中からビームフォーミングが適用される対象装置を選択するよう構成される制御部を備える。前記制御部は、セルのカバレッジを拡張するためのカバレッジ拡張モードの所定装置を前記対象装置として選択するよう構成される。 The base station according to one embodiment includes a control unit configured to select a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station. The control unit is configured to select, as the target device, a predetermined device in a coverage extension mode for extending cell coverage.
　前記制御部は、第１の期間において前記ビームフォーミングを適用すべき候補対象装置の数が、前記第１の期間において許容される前記対象装置の上限数を超えたか否かを判定し、前記候補対象装置の数が前記上限数を超えた場合には、前記候補対象装置のうち、前記対象装置として選択された前記所定装置を、前記第１の期間よりも後の第２の期間における無線リソースの割り当て対象に変更するよう構成されてもよい。 The control unit determines whether or not the number of candidate target devices to which the beamforming should be applied in the first period exceeds the upper limit number of target devices allowed in the first period, and the candidate When the number of target devices exceeds the upper limit number, the predetermined device selected as the target device among the candidate target devices is a wireless resource in a second period after the first period. It may be configured to change to an assignment target of
　前記制御部は、前記第１の期間における無線リソースの割り当てを行った後に、前記対象装置の数が前記上限数を超えるか否かを判定するよう構成されてもよい。 The control unit may be configured to determine whether the number of target devices exceeds the upper limit number after performing allocation of radio resources in the first period.
　前記制御部は、前記第２の期間における無線リソースの割り当て対象に変更された前記所定装置に割り当てられていた前記第１の期間における無線リソースを、前記ビームフォーミングが適用されない非対象装置に割り当てるよう構成されてもよい。 The control unit may allocate the radio resource in the first period allocated to the predetermined device changed to the allocation target of the radio resource in the second period to the non-target device to which the beamforming is not applied. It may be configured.
　前記制御部は、第１の期間における無線リソースを無線通信装置に割り当てる度に、前記無線リソースが割り当てられた対象装置の数が、前記第１の期間において許容される前記対象装置の上限数に達したか否かを判定し、前記対象装置の数が前記上限数に達した場合には、前記第１の期間における無線リソースのうち未割り当ての無線リソースを、前記ビームフォーミングが適用されない非対象装置に割り当てるよう構成されてもよい。 Whenever the control unit allocates a wireless resource in a first period to a wireless communication device, the number of target devices to which the wireless resource is assigned is the upper limit number of target devices allowed in the first period. If the number of target devices has reached the upper limit number, then unassigned radio resources among the radio resources in the first period are not targeted for the beamforming not being applied. It may be configured to be assigned to a device.
　前記制御部は、前記ビームフォーミングが適用されない非対象装置よりも先に、第１の期間における無線リソースを前記対象装置に割り当てるよう構成されてもよい。 The control unit may be configured to assign a radio resource in a first period to the target device before the non-target device to which the beamforming is not applied.
　一の実施形態に係るプロセッサは、基地局を制御するためのプロセッサである。前記プロセッサは、前記基地局の制御下における複数の無線通信装置の中からビームフォーミングが適用される対象装置を選択する処理と、制御部は、セルのカバレッジを拡張するためのカバレッジ拡張モードの所定装置を前記対象装置として選択する処理と、を実行する。 The processor according to one embodiment is a processor for controlling a base station. The processor selects a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station, and the control unit determines a coverage extension mode for extending cell coverage. And a process of selecting a device as the target device.
　一の実施形態に係る通信方法は、基地局は、前記基地局の制御下における複数の無線通信装置の中からビームフォーミングが適用される対象装置を選択するステップを備える。前記選択するステップにおいて、前記基地局は、セルのカバレッジを拡張するためのカバレッジ拡張モードの所定装置を前記対象装置として選択する。 The communication method according to one embodiment includes the step of the base station selecting a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station. In the selecting step, the base station selects, as the target device, a predetermined device in a coverage extension mode for extending the coverage of a cell.
　（通信システムの構成）
　図１は、実施形態に係る通信システム１の構成の一例を示す図である。図１に示すように、通信システム１は、無線通信装置１００と、ホスト機器２００と、無線通信ネットワーク３００と、を備える。なお、通信システム１は、図示していないが、ＷＷＡＮ方式の無線通信を行うＷＷＡＮ通信装置を備えてもよい。 (Configuration of communication system)
FIG. 1 is a diagram showing an example of the configuration of the communication system 1 according to the embodiment. As shown in FIG. 1, the communication system 1 includes a wireless communication device 100, a host device 200, and a wireless communication network 300. Although not shown, the communication system 1 may include a WWAN communication apparatus that performs WWAN wireless communication.
　無線通信装置１００は、無線通信を行う通信装置である。無線通信装置１００は、ユーザ装置（ＵＥ：Ｕｓｅｒ　Ｅｑｕｉｐｍｅｎｔ）と称されてもよい。本実施形態において、無線通信装置１００は、ＬＰＷＡ通信装置１００とも記載する。 The wireless communication device 100 is a communication device that performs wireless communication. The wireless communication device 100 may be referred to as a user equipment (UE: User Equipment). In the present embodiment, the wireless communication device 100 is also described as an LPWA communication device 100.
　３ＧＰＰ（Ｔｈｉｒｄ　Ｇｅｎｅｒａｔｉｏｎ　Ｐａｒｔｎｅｒｓｈｉｐ　Ｐｒｏｊｅｃｔ）システムにおいて、ＬＰＷＡ通信装置１００は、例えば、カテゴリＭ１、及びカテゴリＭ２のいずれかのカテゴリを有するユーザ装置であってもよい。ＷＷＡＮ通信装置は、例えば、カテゴリ０以上のカテゴリ（例えば、カテゴリ１－１２のいずれか、ＤＬカテゴリ６－１７のいずれかなど）を有するユーザ装置であってもよい。ＷＷＡＮ通信装置は、ＷＷＡＮ方式の無線通信を無線通信ネットワーク３００と行う。 In the 3rd Generation Partnership Project (3GPP) system, the LPWA communication apparatus 100 may be, for example, a user apparatus having one of the categories M1 and M2. The WWAN communication apparatus may be, for example, a user apparatus having a category of category 0 or more (eg, any of categories 1-12, any of DL categories 6-17, etc.). The WWAN communication apparatus performs WWAN wireless communication with the wireless communication network 300.
　ＬＰＷＡ通信装置１００は、ＬＰＷＡ方式の無線通信を無線通信ネットワーク３００と行う。ＬＰＷＡ方式は、消費電力を抑えつつ遠距離通信を実現する無線通信の方式である。実施形態において、ＬＰＷＡ方式として、セルラ通信規格の一つである３ＧＰＰ規格において規定されたｅＭＴＣ（ｅｎｈａｎｃｅｄ　Ｍａｃｈｉｎｅ　Ｔｙｐｅ　Ｃｏｍｍｕｎｉｃａｔｉｏｎｓ）方式又はＮＢ（Ｎａｒｒｏｗ　Ｂａｎｄ）－ＩｏＴ方式を用いる。ｅＭＴＣは、ＬＴＥカテゴリＭ１（上記カテゴリＭ１）と称されることがある。ＮＢ－ＩｏＴは、ＬＴＥカテゴリＮＢ１と称されることがある。 The LPWA communication apparatus 100 performs LPWA wireless communication with the wireless communication network 300. The LPWA method is a wireless communication method that realizes long-distance communication while reducing power consumption. In the embodiment, as the LPWA method, an enhanced machine type communication (eMTC) method or an NB (Narrow Band) -IoT method defined in the 3GPP standard which is one of cellular communication standards is used. The eMTC may be referred to as an LTE category M1 (above category M1). NB-IoT may be referred to as LTE category NB1.
　ｅＭＴＣ方式又はＮＢ－ＩｏＴ方式は、通信装置の低コスト化を図るために、無線通信に利用する周波数帯域幅を狭い帯域幅に限定している。なお、ＮＢ－ＩｏＴ方式の無線通信に利用可能な周波数帯域幅は、ｅＭＴＣ方式の無線通信に利用可能な周波数帯域幅よりも狭い。 The eMTC system or the NB-IoT system limits the frequency bandwidth used for wireless communication to a narrow bandwidth in order to reduce the cost of the communication apparatus. Note that the frequency bandwidth available for NB-IoT wireless communication is narrower than the frequency bandwidth available for eMTC wireless communication.
　ＬＰＷＡ通信装置１００は、無線通信ネットワーク３００の通常のエリアのカバレッジ外、例えば地下等に設置されることがある。このため、ｅＭＴＣ方式及びＮＢ－ＩｏＴ方式の両ＬＰＷＡ方式においては、同一信号を繰り返し送信することによってカバレッジを拡張するカバレッジ拡張技術が用いられる。 The LPWA communication apparatus 100 may be installed outside the coverage of the normal area of the wireless communication network 300, for example, underground. Therefore, in both the eMTC method and the NB-IoT LPWA method, a coverage extension technique is used which extends the coverage by repeatedly transmitting the same signal.
　また、ＬＰＷＡ通信装置１００は、データ通信が発生しない期間において無線通信を停止することによって省電力化を実現している。このような省電力技術としては、３ＧＰＰ規格において規定されたｅＤＲＸ（ｅｘｔｅｎｄｅｄ　Ｄｉｓｃｏｎｔｉｎｕｏｕｓ　Ｒｅｃｅｐｔｉｏｎ）及びＰＳＭ（Ｐｏｗｅｒ　Ｓａｖｉｎｇ　Ｍｏｄｅ）がある。ｅＤＲＸは、ＬＰＷＡ通信装置１００が間欠受信を行う際の受信間隔であるＤＲＸサイクルを延長することにより、ＬＰＷＡ通信装置１００が受信機をオフにする期間（オフ期間）を延長し、省電力化を実現するものである。ＰＳＭは、ＬＰＷＡ通信装置１００を、間欠受信すら行わない擬似的な電源オフ状態（ＰＳＭ状態）にすることによって、省電力化を実現するものである。以下において、ｅＤＲＸにおけるオフ期間及びＰＳＭ状態をまとめて「省電力状態」と称する。 Also, the LPWA communication apparatus 100 achieves power saving by stopping wireless communication in a period in which no data communication occurs. As such power saving techniques, there are eDRX (extended discontinuous reception) and PSM (power saving mode) defined in the 3GPP standard. eDRX extends the DRX cycle, which is the reception interval when the LPWA communication device 100 performs intermittent reception, thereby extending the period (off period) in which the LPWA communication device 100 turns the receiver off, thereby saving power. It will be realized. PSM realizes power saving by setting the LPWA communication apparatus 100 in a pseudo power-off state (PSM state) in which even intermittent reception is not performed. Hereinafter, the off period and the PSM state in the eDRX are collectively referred to as a “power saving state”.
　ｅＤＲＸが適用される場合において、待ち受け状態であるアイドル状態にあるＬＰＷＡ通信装置１００は、無線通信ネットワーク３００からの呼び出しであるページングに気付くことができる。一方、ＰＳＭが適用される場合、ＰＳＭ状態にあるＬＰＷＡ通信装置１００は、無線通信ネットワーク３００からのページングに気付くことができない。無線通信ネットワーク３００は、ＬＰＷＡ通信装置１００が省電力状態にあるか否かを把握しており、ＬＰＷＡ通信装置１００が省電力状態にある間はＬＰＷＡ通信装置１００宛のデータを蓄積する。 When eDRX is applied, the LPWA communication apparatus 100 in an idle state, which is in a standby state, can notice paging which is a call from the wireless communication network 300. On the other hand, when PSM is applied, the LPWA communication apparatus 100 in the PSM state can not notice paging from the wireless communication network 300. The wireless communication network 300 knows whether the LPWA communication apparatus 100 is in the power saving state, and stores data addressed to the LPWA communication apparatus 100 while the LPWA communication apparatus 100 is in the power saving state.
　ＬＰＷＡ通信装置１００は、ホスト機器２００に接続される。具体的には、ＬＰＷＡ通信装置１００は、ホスト機器２００に直接接続されるか、又はケーブルを介して間接的にホスト機器２００に接続される。ＬＰＷＡ通信装置１００は、例えば、ＵＡＲＴ（Ｕｎｉｖｅｒｓａｌ　Ａｓｙｎｃｈｒｏｎｏｕｓ　Ｒｅｃｅｉｖｅｒ／Ｔｒａｎｓｍｉｔｔｅｒ）方式又はＵＳＢ（Ｕｎｉｖｅｒｓａｌ　Ｓｅｒｉａｌ　Ｂｕｓ）方式の有線通信をホスト機器２００と行う。 The LPWA communication apparatus 100 is connected to the host device 200. Specifically, the LPWA communication apparatus 100 is directly connected to the host device 200 or indirectly connected to the host device 200 via a cable. The LPWA communication apparatus 100 performs wired communication with, for example, a Universal Asynchronous Receiver / Transmitter (UART) method or a Universal Serial Bus (USB) method with the host device 200.
　ＬＰＷＡ通信装置１００は、ホスト機器２００に接続されなくてもよい。ＬＰＷＡ通信装置１００は、ＷＷＡＮ（Ｗｉｒｅｌｅｓｓ　Ｗｉｄｅ　Ａｒｅａ　Ｎｅｔｗｏｒｋ）方式の無線通信を行う無線通信装置のように、ホスト機器２００から独立した無線通信装置であってもよい。 The LPWA communication apparatus 100 may not be connected to the host device 200. The LPWA communication apparatus 100 may be a wireless communication apparatus independent of the host device 200, such as a wireless communication apparatus that performs wireless communication of the WWAN (Wireless Wide Area Network) method.
　ホスト機器２００は、ＰＣ（Ｐｅｒｓｏｎａｌ　Ｃｏｍｐｕｔｅｒ）、センサ機器、メータ機器、又は自動販売機等である。ホスト機器２００は、ＩｏＴ向けのアプリケーションを実行する。ＬＰＷＡ通信装置１００が接続されたホスト機器２００は、自身が無線通信の機能を有していなくても、ＬＰＷＡ通信装置１００を介して無線通信ネットワーク３００との通信を行うことができる。 The host device 200 is a personal computer (PC), a sensor device, a meter device, a vending machine, or the like. The host device 200 executes an application for IoT. The host device 200 to which the LPWA communication apparatus 100 is connected can communicate with the wireless communication network 300 via the LPWA communication apparatus 100 even if the host apparatus 200 itself does not have the wireless communication function.
　無線通信ネットワーク３００は、通信事業者によって管理されるネットワークである。実施形態において、無線通信ネットワーク３００は３ＧＰＰ規格に準拠した構成を有する。無線通信ネットワーク３００は、基地局３１０と、ＭＭＥ（Ｍｏｂｉｌｉｔｙ　Ｍａｎａｇｅｍｅｎｔ　Ｅｎｔｉｔｙ）３２０と、ＧＷ（Ｇａｔｅｗａｙ）３３０とを有する。 The wireless communication network 300 is a network managed by a telecommunications carrier. In an embodiment, the wireless communication network 300 has a configuration in accordance with the 3GPP standard. The wireless communication network 300 includes a base station 310, an MME (Mobility Management Entity) 320, and a GW (Gateway) 330.
　基地局３１０は、ＬＰＷＡ方式の無線通信をＬＰＷＡ通信装置１００と行う。基地局３１０は、ＭＭＥ３２０及びＧＷ３３０と接続される。 The base station 310 performs LPWA wireless communication with the LPWA communication apparatus 100. The base station 310 is connected to the MME 320 and the GW 330.
　ＭＭＥ３２０は、基地局３１０を介してＮＡＳ（Ｎｏｎ－Ａｃｃｅｓｓ　Ｓｔｒａｔｕｍ）シグナリングを用いてＬＰＷＡ通信装置１００と通信することにより、ＬＰＷＡ通信装置１００が位置するトラッキングエリア（すなわち、ページングを行うエリア単位）等を管理する。また、ＭＭＥ３２０は、ＬＰＷＡ通信装置１００が省電力状態にあるか否かを把握している。 The MME 320 communicates with the LPWA communication apparatus 100 using NAS (Non-Access Stratum) signaling via the base station 310 to thereby establish a tracking area (ie, an area unit to perform paging) in which the LPWA communication apparatus 100 is located. to manage. The MME 320 also determines whether the LPWA communication apparatus 100 is in a power saving state.
　ＧＷ３３０は、ＰＤＮ－ＧＷ（Ｐａｃｋｅｔ　Ｄａｔａ　Ｎｅｔｗｏｒｋ　Ｇａｔｅｗａｙ）と、Ｓ－ＧＷ（Ｓｅｒｖｉｎｇ　Ｇａｔｅｗａｙ）とを含む。ＰＤＮ－ＧＷは、無線通信ネットワーク３００と外部ネットワーク（例えば、インターネット）との間のインターフェイスとして機能する。Ｓ－ＧＷは、ＰＤＮ－ＧＷと基地局３１０との間でデータの転送制御を行う。ＧＷ３３０は、ＭＭＥ３２０と連携し、ＬＰＷＡ通信装置１００が省電力状態にある間は、ＬＰＷＡ通信装置１００宛のデータを蓄積する。ＧＷ３３０は、ＬＰＷＡ通信装置１００が省電力状態から復帰すると、ＬＰＷＡ通信装置１００宛のデータを、ｅＮＢ２００を介してＬＰＷＡ通信装置１００に転送する。 The GW 330 includes a PDN-GW (Packet Data Network Gateway) and an S-GW (Serving Gateway). The PDN-GW functions as an interface between the wireless communication network 300 and an external network (eg, the Internet). The S-GW performs data transfer control between the PDN-GW and the base station 310. The GW 330 cooperates with the MME 320, and accumulates data addressed to the LPWA communication apparatus 100 while the LPWA communication apparatus 100 is in the power saving state. When the LPWA communication apparatus 100 recovers from the power saving state, the GW 330 transfers data addressed to the LPWA communication apparatus 100 to the LPWA communication apparatus 100 via the eNB 200.
　図２は、実施形態に係る通信システム１におけるプロトコルスタックを示す図である。ここでは、外部ネットワーク（外部サーバ）からＬＰＷＡ通信装置１００／ホスト機器２００へのデータの処理の流れについて説明する。 FIG. 2 is a diagram showing a protocol stack in the communication system 1 according to the embodiment. Here, the flow of processing of data from the external network (external server) to the LPWA communication device 100 / host device 200 will be described.
　図２に示すように、外部サーバは、アプリケーション層においてデータを生成する。アプリケーション層において生成されたデータはＳＳＬ（Ｓｅｃｕｒｅ　Ｓｏｃｋｅｔｓ　Ｌａｙｅｒ）による暗号化が施され、トランスポート層（ＵＤＰ又はＴＣＰ）及びＩＰ層において処理された後、イーサネット等の有線通信により無線通信ネットワーク３００に送信される。 As shown in FIG. 2, the external server generates data in the application layer. Data generated in the application layer is encrypted by SSL (Secure Sockets Layer), processed in the transport layer (UDP or TCP) and IP layer, and then transmitted to the wireless communication network 300 by wired communication such as Ethernet. Be done.
　無線通信ネットワーク３００は、イーサネット（登録商標）等の有線通信により無線通信ネットワーク３００からデータを受信し、ＩＰ層及びＩＰアドレス管理においてルーティング処理等が施され、基地局３１０の無線レイヤを介してＬＰＷＡ通信装置１００に送信される。無線レイヤは、３ＧＰＰ規格に準拠した構成を有しており、物理（ＰＨＹ）層、ＭＡＣ（Ｍｅｄｉｕｍ　Ａｃｃｅｓｓ　Ｃｏｎｔｒｏｌ）層、ＲＬＣ（Ｒａｄｉｏ　Ｌｉｎｋ　Ｃｏｎｔｒｏｌ）層、ＰＤＣＰ（Ｐａｃｋｅｔ　Ｄａｔａ　Ｃｏｎｖｅｒｇｅｎｃｅ　Ｐｒｏｔｏｃｏｌ）層、ＲＲＣ（Ｒａｄｉｏ　Ｒｅｓｏｕｒｃｅ　Ｃｏｎｔｒｏｌ）層を含む。 The wireless communication network 300 receives data from the wireless communication network 300 by wired communication such as Ethernet (registered trademark), is subjected to routing processing and the like in IP layer and IP address management, and receives LPWA via the wireless layer of the base station 310. It is transmitted to the communication device 100. The radio layer has a configuration conforming to the 3GPP standard, and includes a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, and an RRC (Radio). Resource Control) layer.
　ＬＰＷＡ通信装置１００は、イーサネット（登録商標）等の有線通信により無線通信ネットワーク３００から無線レイヤ及びＩＰアドレス管理を介してデータを受信する。ＬＰＷＡ通信装置１００は、ＩＰ層、トランスポート層（ＵＤＰ又はＴＣＰ）、ＳＳＬを有する。ＩＰ層は、無線レイヤ及びＩＰアドレス管理を介してＩＰパケットの形式でデータを受信し、受信データをトランスポート層（ＵＤＰ又はＴＣＰ）で処理し、ＳＳＬにより暗号解除（復号）を行う。 The LPWA communication apparatus 100 receives data from the wireless communication network 300 via wireless layer and IP address management by wired communication such as Ethernet (registered trademark). The LPWA communication apparatus 100 has an IP layer, a transport layer (UDP or TCP), and SSL. The IP layer receives data in the form of IP packets via the wireless layer and IP address management, processes the received data in the transport layer (UDP or TCP), and performs decryption (decryption) by SSL.
　ＬＰＷＡ通信装置１００は、暗号解除されたデータをＵＳＢ又はＵＡＲＴを介してホスト機器２００に送信する。ホスト機器２００は、ＵＳＢ又はＵＡＲＴを介してＬＰＷＡ通信装置１００から受信したデータをアプリケーション層により処理する。 The LPWA communication apparatus 100 transmits the decrypted data to the host device 200 via the USB or the UART. The host device 200 processes the data received from the LPWA communication apparatus 100 via the USB or UART by the application layer.
　（無線通信装置の構成）
　図３は、無線通信装置１００の構成を示す図である。 (Configuration of wireless communication device)
FIG. 3 is a diagram showing the configuration of the wireless communication apparatus 100. As shown in FIG.
　無線通信装置１００の構成を、ＬＰＷＡ通信装置１００を例に挙げて説明する。ただし、ＷＷＡＮ通信装置は、ＷＷＡＮ方式の無線通信方式で無線通信ネットワーク３００と無線通信を行う。 The configuration of the wireless communication apparatus 100 will be described by taking the LPWA communication apparatus 100 as an example. However, the WWAN communication apparatus performs wireless communication with the wireless communication network 300 by the WWAN wireless communication method.
　図３に示すように、ＬＰＷＡ通信装置１００は、アンテナ１１０、フロントエンド部１２０、プロセッサ１３０、メモリ１４０、及び電源管理部１５０を有する。ＬＰＷＡ通信装置１００には、図示を省略するインターフェイスを介して、ホスト機器２００、ＵＩＭ（Ｕｓｅｒ　Ｉｄｅｎｔｉｔｙ　Ｍｏｄｕｌｅ）／ＳＩＭ（Ｓｕｂｓｃｒｉｂｅｒ　Ｉｄｅｎｔｉｔｙ　Ｍｏｄｕｌｅ）１６０、及びセンサ１７０を接続可能である。ＵＩＭ／ＳＩＭ１６０は、無線通信ネットワーク３００との無線通信を行うために必要な加入者情報等を記憶する。センサ１７０は、例えば、温度、湿度、気圧、照度、加速度、地磁気等を測定し、測定値を出力する。ＬＰＷＡ通信装置１００は、ＧＮＳＳ（Ｇｌｏｂａｌ　Ｎａｖｉｇａｔｉｏｎ　Ｓａｔｅｌｌｉｔｅ　Ｓｙｓｔｅｍ）受信機（例えば、ＧＰＳ（Ｇｌｏｂａｌ　Ｐｏｓｉｔｉｏｎｉｎｇ　Ｓｙｓｔｅｍ）受信機）をさらに有してもよい。 As shown in FIG. 3, the LPWA communication apparatus 100 includes an antenna 110, a front end unit 120, a processor 130, a memory 140, and a power management unit 150. The host device 200, a User Identity Module (UIM) / Subscriber Identity Module (SIM) 160, and a sensor 170 can be connected to the LPWA communication apparatus 100 via an interface (not shown). The UIM / SIM 160 stores subscriber information and the like necessary for wireless communication with the wireless communication network 300. The sensor 170 measures, for example, temperature, humidity, barometric pressure, illuminance, acceleration, geomagnetism, and the like, and outputs a measured value. The LPWA communication apparatus 100 may further include a Global Navigation Satellite System (GNSS) receiver (for example, a Global Positioning System (GPS) receiver).
　アンテナ１１０は、無線信号の送受信に用いられる。フロントエンド部１２０は、アンテナ１１０が受信した無線信号に対して増幅処理及びフィルタ処理等を行い、無線信号をベースバンド信号に変換してプロセッサ１３０に出力する。また、フロントエンド部１２０は、プロセッサ１３０から入力されたベースバンド信号を無線信号に変換し、増幅処理等を行ってアンテナ１１０に出力する。 The antenna 110 is used to transmit and receive a radio signal. The front end unit 120 performs amplification processing, filter processing, and the like on the radio signal received by the antenna 110, converts the radio signal into a baseband signal, and outputs the baseband signal to the processor 130. Further, the front end unit 120 converts the baseband signal input from the processor 130 into a wireless signal, performs amplification processing and the like, and outputs the signal to the antenna 110.
　プロセッサ１３０は、ＬＰＷＡ通信装置１００における各種の処理及び制御を行う。メモリ１４０は、揮発性メモリ及び不揮発性メモリを含み、プロセッサ１３０により実行されるプログラム、及びプロセッサ１３０による処理に用いられる情報を記憶する。 The processor 130 performs various processing and control in the LPWA communication apparatus 100. The memory 140 includes volatile memory and non-volatile memory, and stores programs executed by the processor 130 and information used for processing by the processor 130.
　電源管理部１５０は、バッテリ及びその周辺回路を含む。電源管理部１５０は、ＬＰＷＡ通信装置１００の駆動電力を供給する。なお、ＬＰＷＡ通信装置１００がホスト機器２００とＵＳＢにより接続される場合、駆動電力がホスト機器２００からＵＳＢ給電により供給されてもよい。 Power management unit 150 includes a battery and its peripheral circuits. The power management unit 150 supplies drive power to the LPWA communication apparatus 100. When the LPWA communication apparatus 100 is connected to the host device 200 by USB, drive power may be supplied from the host device 200 by USB power feeding.
　プロセッサ１３０は、ＬＰＷＡ方式によって無線通信ネットワーク３００との無線通信を行う。プロセッサ１３０は、ＵＤＰを用いて伝送されるデータを無線通信ネットワーク３００から受信する。プロセッサ１３０は、ホスト機器２００と接続されている場合には、ホスト機器２００宛ての受信したデータをホスト機器２００に転送できる。 The processor 130 performs wireless communication with the wireless communication network 300 by the LPWA method. The processor 130 receives data transmitted using the UDP from the wireless communication network 300. When the processor 130 is connected to the host device 200, the processor 130 can transfer the received data addressed to the host device 200 to the host device 200.
　フロントエンド部１２０及びプロセッサ１３０は、データ通信が発生しない期間において、無線通信を停止する省電力状態に移行する。省電力状態時において、フロントエンド部１２０等に対する給電を停止可能であるため、ＬＰＷＡ通信装置１００の省電力化を実現することができる。 The front end unit 120 and the processor 130 shift to a power saving state in which wireless communication is stopped in a period in which no data communication occurs. Since power supply to the front end unit 120 and the like can be stopped in the power saving state, power saving of the LPWA communication apparatus 100 can be realized.
　フロントエンド部１２０及びプロセッサ１３０は、省電力状態に移行してから所定時間経過後に無線通信を再開する。所定時間は、ＤＲＸサイクルにより定められてもよいし、ＰＳＭ用のタイマ値により定められてもよい。ＤＲＸサイクル及びＰＳＭ用のタイマ値は、ＬＰＷＡ通信装置１００及びＭＭＥ３２０で共有される情報である。プロセッサ１３０は、所定時間経過後に無線通信を再開した後、省電力状態である間に無線通信ネットワーク３００（ＧＷ３３０）に蓄積されたデータを受信する。 The front end unit 120 and the processor 130 resume wireless communication after a predetermined time has elapsed since the transition to the power saving state. The predetermined time may be determined by the DRX cycle or may be determined by a timer value for PSM. The timer values for the DRX cycle and the PSM are information shared by the LPWA communication apparatus 100 and the MME 320. The processor 130 resumes wireless communication after a predetermined time has elapsed, and then receives data stored in the wireless communication network 300 (GW 330) while in the power saving state.
　本明細書では、ＬＰＷＡ通信装置１００が備えるアンテナ１１０、フロントエンド部１２０、プロセッサ１３０、メモリ１４０、及び電源管理部１５０のうち少なくともいずれかが実行する処理を、便宜上、ＬＰＷＡ通信装置１００が実行する処理（動作）として説明する。 In the present specification, for convenience, the LPWA communication apparatus 100 executes the process executed by at least one of the antenna 110, the front end unit 120, the processor 130, the memory 140, and the power management unit 150 included in the LPWA communication apparatus 100. Description will be made as processing (operation).
　（基地局の構成）
　図４は、基地局３１０の構成を示す図である。 (Configuration of base station)
FIG. 4 shows the configuration of base station 310. As shown in FIG.
　図４に示すように、基地局３１０は、（複数の）アンテナ３１１、フロントエンド部３１２、プロセッサ３１３、メモリ３１４、及び電源管理部３１５を有する。 As shown in FIG. 4, the base station 310 includes antenna (s) 311, a front end unit 312, a processor 313, a memory 314, and a power management unit 315.
　（複数の）アンテナ３１１は、無線信号の送受信に用いられる。フロントエンド部３１２は、アンテナ３１１が受信した無線信号に対して増幅処理及びフィルタ処理等を行い、無線信号をベースバンド信号に変換してプロセッサ３１３に出力する。また、フロントエンド部３１２は、プロセッサ３１３から入力されたベースバンド信号を無線信号に変換し、増幅処理等を行ってアンテナ３１１に出力する。 The antenna (s) 311 are used to transmit and receive wireless signals. The front end unit 312 performs amplification processing, filter processing, and the like on the wireless signal received by the antenna 311, converts the wireless signal into a baseband signal, and outputs the baseband signal to the processor 313. Further, the front end unit 312 converts the baseband signal input from the processor 313 into a wireless signal, performs amplification processing and the like, and outputs the result to the antenna 311.
　プロセッサ３１３は、基地局３１０における各種の処理及び制御を行う。プロセッサ３１３は、ＬＰＷＡ方式によってＬＰＷＡ通信装置１００との無線通信を行う。プロセッサ１３０は、ＵＤＰを用いて伝送されるデータをＬＰＷＡ通信装置１００から受信する。プロセッサ３１３は、無線通信ネットワーク３００におけるネットワークノード（例えば、ＭＭＥ３２０）とバックホールを介して接続され、ネットワークノードと通信を行う。 The processor 313 performs various processing and control in the base station 310. The processor 313 performs wireless communication with the LPWA communication apparatus 100 by the LPWA method. The processor 130 receives, from the LPWA communication apparatus 100, data to be transmitted using UDP. The processor 313 is connected to a network node (for example, the MME 320) in the wireless communication network 300 via a backhaul and communicates with the network node.
　メモリ３１４は、揮発性メモリ及び不揮発性メモリを含み、プロセッサ３１３により実行されるプログラム、及びプロセッサ３１３による処理に用いられる情報を記憶する。 The memory 314 includes volatile memory and non-volatile memory, and stores programs executed by the processor 313 and information used for processing by the processor 313.
　電源管理部３１５は、バッテリ及びその周辺回路を含む。電源管理部３１５は、基地局３１０の駆動電力を供給する。電源管理部３１５は、外部から駆動電力が供給されてもよい。 The power management unit 315 includes a battery and its peripheral circuits. The power management unit 315 supplies drive power to the base station 310. The power management unit 315 may be externally supplied with drive power.
　本明細書では、基地局３１０が備える（複数の）アンテナ３１１、フロントエンド部３１２、プロセッサ３１３、メモリ３１４、及び電源管理部３１５のうち少なくともいずれかが実行する処理を、便宜上、基地局３１０が実行する処理（動作）として説明する。 In this specification, for convenience, the base station 310 executes processing performed by at least one of the antenna (s) 311, the front end unit 312, the processor 313, the memory 314, and the power management unit 315 that the base station 310 comprises. The process (operation) will be described.
　以下において、無線通信装置１００およびＷＷＡＮ通信装置をＵＥ１００と称し、基地局３１０をＢＳ３１０と称する。 Hereinafter, the wireless communication device 100 and the WWAN communication device will be referred to as a UE 100, and the base station 310 will be referred to as a BS 310.
　（ＣＥモード）
　ＣＥ（Ｃｏｖｅｒａｇｅ　Ｅｎｈａｎｃｅｍｅｎｔ）モードについて説明する。ＣＥモードは、セルのカバレッジを拡張するために導入されたモードである。ＣＥモードは、電波環境の悪いセルエッジのＵＥ１００の接続性を高めるために定義されている。ＣＥモードには、例えば、モードＡ及びモードＢがある。 (CE mode)
The CE (Coverage Enhancement) mode will be described. The CE mode is a mode introduced to extend cell coverage. The CE mode is defined to enhance the connectivity of the UE 100 in a cell edge where the radio environment is bad. The CE mode includes, for example, mode A and mode B.
　モードＡとモードＢとの違いは、例えば、送信繰り返し回数、及び、ＣＱＩ（Ｃｈａｎｎｅｌ　Ｑｕａｌｉｔｙ　Ｉｎｄｉｃａｔｏｒ）フィードバックの有無である。送信繰り返し回数は、モードＡのＵＥ１００よりも多い。送信繰り返し回数は、例えば、最大２０４８回である。また、モードＡでは、ＣＱＩフィードバックが実行されるのに対し、モードＢでは、ＣＱＩフィードバックが実行されない。モードＢは、静止しているＵＥ１００に適用され得る。 The difference between the mode A and the mode B is, for example, the number of transmission repetitions and the presence or absence of CQI (Channel Quality Indicator) feedback. The number of transmission repetitions is larger than that of the mode A UE 100. The number of transmission repetitions is, for example, 2048 at maximum. Also, in mode A, CQI feedback is performed, whereas in mode B, CQI feedback is not performed. Mode B may be applied to the stationary UE 100.
　ＵＥ１００は、ＢＳ３１０からの参照信号の受信強度によって、ＣＥモードを適用するか否か（すなわち、ＣＥモードに遷移するか否か）を決定する。ＣＥモードが適用されたＵＥ（ＣＥモードのＵＥ）１００は、拡張カバレッジ内に存在するとみなすことができる。 The UE 100 determines whether to apply the CE mode (that is, whether to transition to the CE mode) according to the reception strength of the reference signal from the BS 310. The UE (CE mode UE) 100 to which the CE mode is applied can be considered to be within the extended coverage.
　ＣＥモードのＵＥ１００は、拡張カバレッジ機能を使用するセルへアクセスすることができる。ＵＥ１００は、例えば、ＢＬ　ＵＥ（Ｂａｎｄｗｉｄｔｈ　ｒｅｄｕｃｅｄ　Ｌｏｗ　ｃｏｍｐｌｅｘｉｔｙ　ＵＥ）のためのＳＩＢ１用のスケジューリング情報がスケジューリングされることをセルのＭＩＢ（Ｍａｓｔｅｒ　Ｉｎｆｏｒｍａｔｉｏｎ　Ｂｌｏｃｋ）が示す場合にのみ、当該セルへアクセスできてもよい。 The UE 100 in CE mode can access a cell using the extended coverage function. The UE 100 may be able to access the cell, for example, only when a cell's MIB (Master Information Block) indicates that scheduling information for SIB 1 for a BL reduced to UE (Bandwidth reduced low complexity UE) is scheduled. .
　ＢＳ３１０は、例えば、ＳＩＢ（Ｓｙｓｔｅｍ　Ｉｎｆｏｒｍａｔｉｏｎ　Ｂｌｏｃｋ）で、拡張カバレッジレベルにそれぞれ関連付けられた、ＰＲＡＣＨ（Ｐｈｙｓｉｃａｌ　Ｒａｎｄｏｍ　Ａｃｃｅｓｓ　Ｃｈａｎｎｅｌ）リソースのセット（例えば、時間・周波数リソース、プレアンブルなど）を提供することができる。ＢＳ３１０は、例えば、拡張カバレッジレベル毎のＰＲＡＣＨ繰り返し回数（Ｎｕｍｂｅｒ　ｏｆ　ＰＲＡＣＨ　ｒｅｐｅｔｉｔｉｏｎｓ）及び最大プレアンブル送信試行回数（ｎｕｍｂｅｒ　ｏｆ　ｍａｘｉｍｕｍ　ｐｒｅａｍｂｌｅ　ｔｒａｎｓｍｉｓｓｉｏｎ　ａｔｔｅｍｐｔｓ）を提供することができる。同じ拡張カバレッジレベル内のＵＥ１００は、同じ拡張カバレッジレベルに関連付けられたランダムアクセスリソースを使用する。このため、ＢＳ３１０は、ＵＥ１００がＰＲＡＣＨ信号を送信するために用いたＰＲＡＣＨリソースのセットに基づいて、当該ＵＥ１００が、ＣＥモードが適用しているか否か（すなわち、当該ＵＥ１００がＣＥモードＵＥであるか否か）を判定することができる。 The BS 310 may provide, for example, a set of Physical Random Access Channel (PRACH) resources (eg, time-frequency resources, preambles, etc.) associated with the extended coverage level, for example, in a System Information Block (SIB). The BS 310 may provide, for example, the number of PRACH repetitions per extended coverage level and the number of maximum preamble transmission attempts. UEs 100 within the same enhanced coverage level use random access resources associated with the same enhanced coverage level. Therefore, based on the set of PRACH resources used by the UE 100 to transmit the PRACH, the BS 310 determines whether the UE 100 applies the CE mode (ie, whether the UE 100 is the CE mode UE) Or not) can be determined.
　（ＣＥリストの管理）
　ＣＥリストの管理について説明する。ＢＳ３１０は、ＢＳ３１０の制御下におけるＵＥ１００がＣＥモードであるか否かを把握するために、ＣＥリストを管理する。ＢＳ３１０は、必要に応じて、ＣＥリストを生成、更新、削除できる。 (Management of CE list)
The management of the CE list will be described. The BS 310 manages the CE list in order to grasp whether the UE 100 under the control of the BS 310 is in the CE mode. The BS 310 can generate, update, and delete the CE list as needed.
　ＣＥリストは、ＣＥモードのＵＥ１００の識別子（例えば、Ｃ－ＲＮＴＩ（Ｃｅｌｌ－Ｒａｄｉｏ．　Ｎｅｔｗｏｒｋ　Ｔｅｍｐｏｒａｒｙ　Ｉｄｅｎｔｉｆｉｅｒ）、ＩＭＳＩ（Ｉｎｔｅｒｎａｔｉｏｎａｌ　Ｍｏｂｉｌｅ　Ｓｕｂｓｃｒｉｂｅｒ　Ｉｄｅｎｔｉｔｙ）、ＩＭＥＩ（Ｉｎｔｅｒｎａｔｉｏｎａｌ　Ｍｏｂｉｌｅ　Ｅｑｕｉｐｍｅｎｔ　Ｉｄｅｎｔｉｆｉｅｒ）、ＭＥＩＤ（Ｍｏｂｉｌｅ　Ｅｑｕｉｐｍｅｎｔ　Ｉｄｅｎｔｉｆｉｅｒ）の少なくともいずれか）のリストであってもよい。ＢＳ３１０は、ＵＥ１００が通常モードからＣＥモードに遷移した（又はＵＥ１００がＣＥモードである）場合に、ＵＥ１００の識別子をＣＥリストに追加してもよい。ＢＳ３１０は、ＵＥ１００がＣＥモードから通常モードに遷移した（ＣＥモードでなくなった）場合に、ＵＥ１００の識別子をＣＥリストから削除してもよい。 The CE list includes at least an identifier of the UE 100 in CE mode (for example, C-RNTI (Cell-Radio. Network Temporary Identifier), IMSI (International Mobile Subscriber Identity), IMEI (International Mobile Equipment Identifier), MEID (Mobile Equipment Identifier)). It may be a list of any). The BS 310 may add the identifier of the UE 100 to the CE list when the UE 100 transitions from the normal mode to the CE mode (or the UE 100 is in the CE mode). The BS 310 may delete the identifier of the UE 100 from the CE list, when the UE 100 transitions from the CE mode to the normal mode (the CE mode is not a CE mode).
　ＣＥリストでは、ＵＥ１００がＣＥモードであるか否かが示されてもよい。すなわち、ＣＥリストにおいて、ＵＥ１００がＣＥモードであるか否か（通常モード／ＣＥモード）を示す情報がＵＥ１００の識別子と関連付けられてもよい。これにより、ＢＳ３１０は、ＵＥ１００がＣＥモードであるか否かを判定できる。ＢＳ３１０は、ＵＥ１００のモード（通常モード／ＣＥモード）が変更されたことに応じて、ＣＥリストを更新する。 The CE list may indicate whether the UE 100 is in the CE mode. That is, in the CE list, information indicating whether or not the UE 100 is in the CE mode (normal mode / CE mode) may be associated with the identifier of the UE 100. Thus, the BS 310 can determine whether the UE 100 is in the CE mode. The BS 310 updates the CE list in response to the change of the mode (normal mode / CE mode) of the UE 100.
　ＣＥリストでは、ＵＥ１００がどのＣＥモードであるか（モードＡ／モードＢ）を示す情報がＵＥ１００の識別子と関連付けられてもよい。ＣＥリストでは、ＵＥ１００がどの拡張カバレッジレベルであるかを示す情報がＵＥ１００の識別子と関連付けられてもよい。 In the CE list, information indicating which CE mode the UE 100 is in (mode A / mode B) may be associated with the identifier of the UE 100. In the CE list, information indicating which extended coverage level the UE 100 is at may be associated with the identifier of the UE 100.
　ＣＥリストでは、ＵＥ１００の端末情報がＵＥ１００の識別子と関連付けられてもよい。ＵＥ１００の端末情報は、通常のＵＥ１００（すなわち、通常モードのＵＥ１００）よりもデータ遅延が許容されるＵＥ（例えば、ＬＰＷＡ端末、ＭＴＣ（Ｍａｃｈｉｎｅ　Ｔｙｐｅ　Ｃｏｍｍｕｎｉｃａｔｉｏｎ）端末など）であることを示す情報である。端末情報は、例えば、ＵＥケイパビリティ情報、ＵＥカテゴリ情報の少なくともいずれかである。 In the CE list, terminal information of the UE 100 may be associated with an identifier of the UE 100. The terminal information of the UE 100 is information indicating that it is a UE (for example, an LPWA terminal, an MTC (Machine Type Communication) terminal, etc.) that allows a data delay than the normal UE 100 (that is, the UE 100 in the normal mode). The terminal information is, for example, at least one of UE capability information and UE category information.
　ＣＥリストでは、ＵＥ１００に対してビームフォーミングを適用できるか否かを示す情報が、ＵＥ１００の識別子と関連付けられてもよい。ＢＳ３１０は、例えば、ＵＥ１００へビームを向けるために用いられる情報（例えば、参照信号（ＳＲＳ（Ｓｏｕｎｄｉｎｇ　Ｒｅｆｅｒｅｎｃｅ　Ｓｉｇｎａｌ））、又はフィードバック情報など）を受信したＵＥ１００がビームフォーミングを適用できると判定してもよい。ＢＳ３１０は、当該情報を受信していないＵＥ１００がビームフォーミングを適用できないＵＥ１００と判定してもよい。ＢＳ３１０は、例えば、当該情報を送信するための無線リソースを割り当てたＵＥ１００がビームフォーミングを適用できると判定してもよい。ＢＳ３１０は、フィードバック情報を送信するための無線リソースを割り当てていないＵＥ１００がビームフォーミングを適用でないＵＥ１００と判定してもよい。 In the CE list, information indicating whether or not beamforming can be applied to the UE 100 may be associated with the identifier of the UE 100. For example, the BS 310 may determine that the UE 100 that has received information (for example, a reference signal (SRS (Sounding Reference Signal)) or feedback information) used to direct a beam to the UE 100 can apply beamforming. . The BS 310 may determine that the UE 100 that has not received the information is the UE 100 to which beamforming can not be applied. For example, the BS 310 may determine that the UE 100 to which a radio resource for transmitting the information has been allocated can apply beamforming. The BS 310 may determine that the UE 100 to which the radio resource for transmitting feedback information is not assigned is the UE 100 to which beamforming is not applied.
　フィードバック情報は、例えば、チャネル状態情報（ＣＳＩ：Ｃｈａｎｎｅｌ　Ｓｔａｔｅ　Ｉｎｆｏｒｍａｔｉｏｎ）である。ＵＥ１００は、ＢＳ３１０からの参照信号（ＣＳＩ－ＲＳ）に基づいてＣＳＩを生成できる。 The feedback information is, for example, channel state information (CSI: Channel State Information). The UE 100 can generate CSI based on a reference signal (CSI-RS) from the BS 310.
　ＣＳＩは、ＰＭＩ（Ｐｒｅｃｏｄｉｎｇ　Ｍａｔｒｉｘ　Ｉｎｄｉｃａｔｏｒ）、ＲＩ（Ｒａｎｋ　Ｉｎｄｉｃａｔｏｒ）を含んでいてもよい。ＰＭＩは、下りリンクで用いるのに好ましいプリコーダ行列を示す情報である。言い換えると、ＰＭＩは、当該ＰＭＩの送信元のＵＥ１００に対してビームが向くプリコーダ行列を示す情報である。ＵＥ１００は、自身の受信状態が改善されるように、ＢＳ３１０にフィードバックするＰＭＩを選択する。ＲＩは、下りリンクで用いるのに好ましいランクを示す。例えば、ＵＥ１００は、自身の受信状態に相応しいランクが適用されるように、ＢＳ３１０にフィードバックするＲＩを選択する。 CSI may include PMI (Precoding Matrix Indicator) and RI (Rank Indicator). PMI is information indicating a precoder matrix preferable for use in downlink. In other words, PMI is information indicating a precoder matrix in which the beam is directed to the UE 100 that is the transmission source of the PMI. The UE 100 selects a PMI to be fed back to the BS 310 such that its reception condition is improved. RI indicates a preferred rank for use in downlink. For example, the UE 100 selects an RI to be fed back to the BS 310 such that a rank appropriate to its reception state is applied.
　ＢＳ３１０は、フィードバック情報に基づいて、ＵＥ１００－ＢＳ３１０間の伝搬路を推定するための演算を実行してもよい。ＢＳ３１０は、算出された伝搬路に基づいて、送信プリコーディングウェイトを生成するための演算を行ってもよい。ＢＳ３１０は、生成された送信プリコーディングウェイトに基づいて、ビームフォーミングを制御できる。 The BS 310 may perform an operation to estimate a channel between the UE 100 and the BS 310 based on the feedback information. The BS 310 may perform an operation for generating a transmission precoding weight based on the calculated propagation path. The BS 310 can control beamforming based on the generated transmission precoding weights.
　ＢＳ３１０は、ＳＲＳに基づいて生成されたＣＳＩを用いて、送信プリコーディングウェイトを生成してもよい。 The BS 310 may generate transmission precoding weights using CSI generated based on SRS.
　ＢＳ３１０は、ＣＥモードを更新するために、例えば、以下の方法により、ＵＥ１００がＣＥモードであるか否かを判定できる。 The BS 310 can determine whether the UE 100 is in the CE mode, for example, by the following method, in order to update the CE mode.
　第１に、ＢＳ３１０は、ＵＥ１００からのＰＲＡＣＨ信号に基づいて判定できる。ＢＳ３１０は、ＣＥモード用のＲＡＣＨリソースのセットを用いて送信されたＰＲＡＣＨ信号を受信した場合、送信元のＵＥ１００がＣＥモードであると判定する。そうでない場合、送信元のＵＥ１００は、通常モードである（ＣＥモードでない）と判定する。 First, the BS 310 can make a determination based on the PRACH signal from the UE 100. When the BS 310 receives the PRACH signal transmitted using the set of RACH resources for the CE mode, the BS 310 determines that the UE 100 of the transmission source is in the CE mode. If not, the transmission source UE 100 determines that it is in the normal mode (not in the CE mode).
　第２に、ＢＳ３１０は、ＵＥ１００からの測定報告に基づいて判定できる。ＢＳ３１０は、測定報告に含まれるＢＳ３１０（が管理するセル）からの参照信号の受信強度が閾値未満である場合、ＵＥ１００がＣＥモードであると判定する。そうでない場合、ＵＥ１００は、通常モードであると判定する。 Second, the BS 310 can make the determination based on the measurement report from the UE 100. The BS 310 determines that the UE 100 is in the CE mode when the reception strength of the reference signal from (the cell managed by) the BS 310 included in the measurement report is less than the threshold. Otherwise, the UE 100 determines that it is in the normal mode.
　第３に、ＢＳ３１０は、ＵＥ１００のハンドオーバ元のＢＳ３１０（ソースＢＳ）からの情報に基づいて判定できる。ＢＳ３１０は、ＵＥ１００がＣＥモードであることを示す情報をソースＢＳから受信した場合に、ＵＥ１００がＣＥモードであると判定する。そうでない場合、ＵＥ１００は、通常モードであると判定する。 Third, the BS 310 can make a determination based on information from the BS 310 (source BS) of the handover source of the UE 100. The BS 310 determines that the UE 100 is in the CE mode when the information indicating that the UE 100 is in the CE mode is received from the source BS. Otherwise, the UE 100 determines that it is in the normal mode.
　第４に、ＢＳ３１０は、通常モードからＣＥモードへ変更するためのメッセージ（例えば、ＲＲＣ再設定メッセージ）をＵＥ１００へ送信した場合に、ＵＥ１００がＣＥモードであると判定する。ＢＳ３１０は、ＣＥモードから通常モードへ変更するためのメッセージ（例えば、ＲＲＣ再設定メッセージ）をＵＥ１００へ送信した場合に、ＵＥ１００が通常モードであると判定する。 Fourth, when the BS 310 transmits, to the UE 100, a message for changing from the normal mode to the CE mode (for example, an RRC reconfiguration message), the BS 310 determines that the UE 100 is in the CE mode. When the BS 310 transmits to the UE 100 a message for changing from the CE mode to the normal mode (for example, an RRC reconfiguration message), the BS 310 determines that the UE 100 is in the normal mode.
　（実施形態に係る動作）
　実施形態に係る動作例について説明する。具体的には、動作例１－３を例に挙げて説明する。 (Operation according to the embodiment)
An operation example according to the embodiment will be described. Specifically, an operation example 1-3 will be described as an example.
　（動作例１）       
　動作例１について、図５を用いて説明する。図５は、実施形態に係る動作例１を説明するための図である。 (Operation example 1)
The operation example 1 will be described with reference to FIG. FIG. 5 is a diagram for explaining an operation example 1 according to the embodiment.
　図５に示すように、ステップＳ１１０において、ＢＳ３１０は、第１期間において、各ＵＥ１００への送信データをスケジューリングする。 As shown in FIG. 5, in step S110, the BS 310 schedules transmission data to each UE 100 in a first period.
　ＢＳ３１０は、各ＵＥ１００への送信データをネットワークから受信したことに応じて、送信データを送信するための無線リソース（時間・周波数リソース）を各ＵＥ１００へ割り当てる。ＢＳ３１０は、一般的な無線リソースのスケジューリングを実行できる。 In response to reception of transmission data to each UE 100 from the network, the BS 310 allocates, to each UE 100, a radio resource (time / frequency resource) for transmitting the transmission data. The BS 310 can perform general radio resource scheduling.
　第１期間は、例えば、ＢＳ３１０が一度にスケジューリングできる期間である。第１期間は、１つの送信機会であってもよい。第１期間は、例えば、１無線フレーム、１サブフレーム、１スロットのいずれかであってもよい。無線フレームは、時間方向に並ぶ１０個のサブフレームで構成される。各サブフレームは、時間方向に並ぶ２個のスロットで構成される。各サブフレームの長さは１ｍｓである。各スロットの長さは０．５ｍｓである。 The first period is, for example, a period during which the BS 310 can schedule at one time. The first period may be one transmission opportunity. The first period may be, for example, one radio frame, one subframe, or one slot. The radio frame is composed of ten subframes aligned in the time direction. Each subframe is composed of two slots aligned in the time direction. The length of each subframe is 1 ms. The length of each slot is 0.5 ms.
　ステップＳ１１０におけるスケジューリングは、仮のスケジューリングである。後述するように、あるＵＥ１００へ割り当てられた無線リソースが他のＵＥ１００へ割り当てられる可能性がある。 The scheduling in step S110 is tentative scheduling. As described later, there is a possibility that a radio resource assigned to one UE 100 is assigned to another UE 100.
　ステップＳ１２０において、ＢＳ３１０は、無線リソースが割り当てられた複数のＵＥ１００の中から、ビームフォーミングが適用されるＵＥ（以下、ＢＦ対象ＵＥと適宜称する）を選択（決定）する。ＢＳ３１０は、ＣＥモードのＵＥ１００（所定ＵＥ１００）をＢＦ対象ＵＥとして選択する。 In step S120, the BS 310 selects (determines) a UE to which beamforming is applied (hereinafter, appropriately referred to as a BF target UE) from among a plurality of UEs 100 to which radio resources are allocated. The BS 310 selects the UE 100 in the CE mode (predetermined UE 100) as a BF target UE.
　ＢＳ３１０は、ＣＥリストに基づいて、ＢＦ対象ＵＥを選択する。例えば、ＢＳ３１０は、無線リソースが割り当てられたＵＥ１００の識別子がＣＥリストに含まれる場合、当該ＵＥ１００をＢＦ対象ＵＥとして選択する。 The BS 310 selects the BF target UE based on the CE list. For example, when the identifier of the UE 100 to which the radio resource is allocated is included in the CE list, the BS 310 selects the UE 100 as a BF target UE.
　ＢＳ３１０は、ＣＥモードのＵＥ１００をＢＦ対象ＵＥとして優先的に選択してもよい。例えば、ＢＳ３１０は、ＣＥモードのＵＥ１００をＢＦ対象ＵＥとして選択した後に、通常モードのＵＥ１００をＢＦ対象ＵＥとして選択するか否かを判定してもよい。ＢＳ３１０は、ＣＥモードのＵＥ１００の数が通常モードのＵＥ１００の数よりも多くなるように、ＢＦ対象ＵＥを選択してもよい。ＢＳ３１０は、ＣＥモードのＵＥ１００が通常モードのＵＥ１００よりもＢＦ対象ＵＥとして選択されやすくなるためのアルゴリズムを用いて、ＢＦ対象ＵＥを選択してもよい。 The BS 310 may preferentially select the UE 100 in the CE mode as a BF target UE. For example, after selecting the UE 100 in the CE mode as the BF target UE, the BS 310 may determine whether to select the normal mode UE 100 as the BF target UE. The BS 310 may select the BF target UEs such that the number of UEs 100 in CE mode is greater than the number of UEs 100 in normal mode. The BS 310 may select the BF target UE using an algorithm for making the UE 100 in the CE mode easier to select as the BF target UE than the UE 100 in the normal mode.
　ＢＦ対象ＵＥとして選択されたＵＥ１００は、第１の期間においてビームフォーミングを適用すべき候補ＢＦ対象ＵＥである。後述するように、候補ＢＦ対象ＵＥは、第１の期間においてビームフォーミングが適用されない可能性がある。 The UE 100 selected as the BF target UE is a candidate BF target UE to which beamforming should be applied in the first period. As described later, candidate BF targets UE may not have beamforming applied in the first period.
　ステップＳ１３０において、ＢＳ３１０は、候補ＢＦ対象ＵＥの数が、第１の期間において許容されるＢＦ対象ＵＥの上限数（許容ＵＥ数）を超えるか否かを判定する。 In step S130, the BS 310 determines whether or not the number of candidate BF target UEs exceeds the upper limit number (the allowable number of UEs) of the BF target UEs permitted in the first period.
　許容ＵＥ数は、例えば、ＢＳ３１０の処理能力（ＣＰＵ：Ｃｅｎｔｒａｌ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ）に応じて、予め決定されてもよい。ＵＥ１００へビームを向けるために用いられる情報（ＳＲＳ、フィードバック情報など）を送信するために用いられる無線リソース量に応じて、予め決定されてもよい。 The allowable number of UEs may be determined in advance according to, for example, the processing capability (CPU: Central Processing Unit) of the BS 310. It may be determined in advance according to the amount of radio resources used to transmit information (SRS, feedback information, etc.) used to direct the beam to the UE 100.
　ＢＳ３１０は、第１の期間における無線リソースの割り当てを行った後に、ＢＦ対象ＵＥの数が許容ＵＥ数を超えるか否かを判定できる。これにより、ＢＦ対象ＵＥの数が許容ＵＥ数を超えなければ、通常のスケジューリング（例えば、優先度制御を伴うスケジューリング）と同じスケジューリングであるため、ＢＳ３１０は、適切にスケジューリングを実行可能である。 After allocating radio resources in the first period, the BS 310 may determine whether the number of BF target UEs exceeds the number of allowable UEs. By this means, if the number of BF target UEs does not exceed the allowable number of UEs, the BS 310 can execute scheduling appropriately, since it is the same scheduling as normal scheduling (for example, scheduling with priority control).
　ＢＳ３１０は、候補ＢＦ対象ＵＥの数が、許容ＵＥ数を超える場合に、ステップＳ１４０の処理を実行する。そうでない場合、ＢＳ３１０は、処理を終了する。すなわち、ＢＳ３１０は、ステップＳ１１０において決定されたスケジューリングを用いて、各ＵＥ１００との通信を実行する。ＢＳ３１０は、ＢＦ対象ＵＥとして選択された全てのＵＥ１００に対して、ビームフォーミングを適用する。 The BS 310 executes the process of step S140 when the number of candidate BF target UEs exceeds the allowable number of UEs. If not, the BS 310 ends the process. That is, BS 310 performs communication with each UE 100 using the scheduling determined in step S110. The BS 310 applies beamforming to all UEs 100 selected as BF target UEs.
　ステップＳ１４０において、ＢＳ３１０は、候補ＢＦ対象ＵＥのうち、ＣＥモードのＵＥ１００（所定ＵＥ１００）を、第１の期間よりも後の第２の期間（例えば、第１の期間の次の期間）における無線リソースの割り当て対象に変更する。 In step S140, the BS 310 wirelessly transmits the UE 100 (predetermined UE 100) in the CE mode among the candidate BF target UEs in a second period (for example, a period subsequent to the first period) after the first period. Change to resource allocation target.
　ＢＳ３１０は、例えば、候補ＢＦ対象ＵＥの数と許容ＵＥ数との差と等しい数（又は差以上の数）の所定ＵＥ１００を選択する。ＢＳ３１０は、選択した所定ＵＥ１００を第２の期間における無線リソースの割り当て対象に変更する。 The BS 310 selects, for example, a number (or a number equal to or greater than the difference) of predetermined UEs 100 equal to the difference between the number of candidate BF target UEs and the number of allowable UEs. The BS 310 changes the selected predetermined UE 100 to a radio resource allocation target in the second period.
　ＢＳ３１０は、無線リソースの割り当て対象の変更が初めてである所定ＵＥ１００を選択してもよい。ＢＳ３１０は、無線リソースの割り当て対象の変更の数がより少ない所定ＵＥ１００から順に選択してもよい。ＢＳ３１０は、送信すべき情報の優先度に応じて、所定ＵＥ１００を選択してもよい。ＢＳ３１０は、送信すべき情報の優先度が低い所定ＵＥ１００を選択してもよい。 The BS 310 may select a predetermined UE 100 for which the change of the radio resource allocation target is the first time. The BS 310 may select in order from a predetermined UE 100 with a smaller number of changes of radio resource allocation targets. The BS 310 may select the predetermined UE 100 according to the priority of the information to be transmitted. The BS 310 may select a predetermined UE 100 in which the priority of the information to be transmitted is low.
　ＢＳ３１０は、ＣＥリストに基づいて、所定ＵＥ１００を選択してもよい。例えば、ＢＳ３１０は、ＣＥリスト（ＣＥモードＡ／ＣＥモードＢ）に基づいて、ＣＥモードＢの所定ＵＥ１００を選択してもよい。ＣＥモードＢのＵＥ１００は、静止しているＵＥ１００に適用されるため、ビームの精度が高くなり、ＵＥ１００の受信品質を向上できる。 The BS 310 may select the predetermined UE 100 based on the CE list. For example, the BS 310 may select a predetermined UE 100 of CE mode B based on the CE list (CE mode A / CE mode B). Since the UE 100 in CE mode B is applied to the stationary UE 100, the accuracy of the beam is enhanced, and the reception quality of the UE 100 can be improved.
　ＢＳ３１０は、ＣＥリスト（ＵＥ１００の端末情報）に基づいて、ＷＷＡＮ通信装置ではなく、ＬＰＷＡ通信装置１００を選択してもよい。ＬＰＷＡ通信装置１００は、送信情報の遅延が許容される可能性が高いので、後述するように、ＬＰＷＡ通信装置１００は、第２の期間における無線リソースの割り当て対象に選択されても、問題が発生しない。 The BS 310 may select the LPWA communication apparatus 100 instead of the WWAN communication apparatus based on the CE list (terminal information of the UE 100). Since the LPWA communication apparatus 100 is likely to tolerate the delay of the transmission information, as will be described later, even if the LPWA communication apparatus 100 is selected as a target of radio resource allocation in the second period, a problem occurs. do not do.
　ステップＳ１５０において、ＢＳ３１０は、第２の期間における無線リソースの割り当て対象に変更された所定ＵＥ１００に割り当てられていた第１の期間における無線リソース（空きリソース）を、ビームフォーミングが適用されないＵＥ１００（非ＢＦ対象ＵＥ）へ割り当てる。 In step S150, the BS 310 does not apply beamforming to a radio resource (free resource) in the first period allocated to the predetermined UE 100 changed to the allocation target of the radio resource in the second period. Assign to the target UE).
　ＢＳ３１０は、選択した所定ＵＥ１００を第２の期間における無線リソースの割り当て対象に変更することにより、選択した所定ＵＥ１００に割り当てられていた無線リソースが空きリソースとして発生する。これにより、無線リソースを有効活用することができる。 By changing the selected predetermined UE 100 to the allocation target of the radio resource in the second period, the radio resource allocated to the selected predetermined UE 100 is generated as a vacant resource. This makes it possible to use wireless resources effectively.
　ＢＳ３１０は、空きリソース領域が埋まるまで、非ＢＦ対象ＵＥへ無線リソースを割り当てるスケジューリングを実行できる。ＢＳ３１０は、非ＢＦ対象ＵＥのうち、送信すべき情報の優先度が高いＵＥ１００から、無線リソースを割り当ててもよい。 The BS 310 can perform scheduling to allocate radio resources to non-BF target UEs until the free resource area is filled. The BS 310 may allocate radio resources from the UE 100 having high priority of information to be transmitted among non-BF target UEs.
　ＢＳ３１０は、処理が終了することにより、第１期間におけるスケジューリングが完了する。ＢＳ３１０は、スケジューリングに基づいて、第１期間において各ＵＥ１００へ情報を送信する。 The BS 310 completes the scheduling in the first period as the process ends. The BS 310 transmits information to each UE 100 in a first period based on scheduling.
　ＢＳ３１０は、第１期間の次の第２の期間でも、上述と同様に、スケジューリングを実行できる。 The BS 310 can perform scheduling in the second period following the first period as described above.
　以上のように、ＢＳ３１０は、ＣＥモードのＵＥ１００をＢＦ対象ＵＥとして選択する。ＣＥモードのＵＥ１００は、通常のセルのカバレッジ内に存在するＵＥ１００よりも、受信環境が悪い。ＢＳ３１０は、ＢＳ３１０の制御下における複数のＵＥ１００のうち、ＣＥモードのＵＥ１００をＢＦ対象ＵＥとして選択することにより、ＢＳ３１０の処理負荷を低減できると共に、ＣＥモードのＵＥ１００の受信品質を向上することができる。 As described above, the BS 310 selects the UE 100 in the CE mode as the BF target UE. The UE 100 in the CE mode has a worse reception environment than the UE 100 existing in the coverage of a normal cell. The BS 310 can reduce the processing load of the BS 310 and improve the reception quality of the UE 100 in the CE mode by selecting the UE 100 in the CE mode as a BF target UE among the plurality of UEs 100 under the control of the BS 310 .
　ＢＳ３１０は、候補ＢＦ対象ＵＥの数が許容ＵＥ数を超える場合には、ＣＥモードのＵＥ１００を第２期間における無線リソースの割り当て対象に変更する。すなわち、ＢＳ３１０は、ＣＥモードのＵＥ１００への送信タイミングを次の送信機会へシフトする。これにより、ＢＦ３１０は、ビームフォーミングを適用可能であるＵＥ１００の数だけ、順番に処理をすることにより、ＣＥモードのＵＥ１００をできるだけＢＦ対象ＵＥとして選択できる。従って、ＢＳ３１０は、ＢＳ３１０の処理能力が原因で、第１の期間において、全てのＣＥモードのＵＥ１００にはビームフォーミングを適用できない場合であっても、複数の期間において全てのＣＥモードのＵＥ１００にビームフォーミングを適用することにより、ＣＥモードのＵＥ１００の受信品質を向上することができる。 When the number of candidate BF target UEs exceeds the allowable number of UEs, the BS 310 changes the UE 100 in the CE mode to an allocation target of radio resources in the second period. That is, BS 310 shifts the transmission timing to UE 100 in the CE mode to the next transmission opportunity. As a result, the BF 310 can select the UE 100 in the CE mode as the BF target UE as much as possible by performing processing in order by the number of UEs 100 to which beamforming can be applied. Accordingly, BS 310 beams all UEs 100 in CE mode in a plurality of periods even if beamforming can not be applied to UEs 100 in all CE modes in the first period due to the processing capacity of BS 310. By applying the forming, it is possible to improve the reception quality of the UE 100 in the CE mode.
　ＣＥモードのＵＥ１００（特に、ＬＰＷＡ通信装置１００）は、送信情報の遅延が許容される可能性が高いので、ＢＳ３１０は、多くのＣＥモードのＵＥ１００をＢＦ対象ＵＥとして選択できる。ＢＳ３１０は、次の送信機会へシフトした場合の遅延が許容されない送信情報を保持する場合には、送信情報の送信先のＵＥ１００を、次の期間の無線リソースの割り当て対象として選択できなくてもよい。 Since the UE 100 in the CE mode (in particular, the LPWA communication device 100) is likely to tolerate the delay of the transmission information, the BS 310 can select the UE 100 in many CE modes as the BF target UE. The BS 310 may not be able to select the UE 100 as the transmission destination of the transmission information as the allocation target of the radio resource in the next period, when holding transmission information whose delay in the case of shifting to the next transmission opportunity is not acceptable. .
　（動作例２）
　動作例２について、図６を用いて説明する。図６は、実施形態に係る動作例２を説明するための図である。上述と同様の部分は、説明を省略する。 (Operation example 2)
Operation example 2 will be described with reference to FIG. FIG. 6 is a diagram for explaining an operation example 2 according to the embodiment. The same parts as those described above will not be described.
　動作例２では、ＢＳ３１０は、無線リソースをＵＥ１００に割り当てる度に、無線リソースが割り当てられたＵＥ１００の数が許容ＵＥ数に達したか否かを判定する。 In the operation example 2, every time the radio resource is allocated to the UE 100, the BS 310 determines whether the number of UEs 100 to which the radio resource is allocated has reached the allowable number of UEs.
　図６に示すように、ステップＳ２１０において、ＢＳ３１０は、１つのＵＥ１００に対する第１期間におけるスケジューリングを実行する。 As shown in FIG. 6, in step S210, the BS 310 performs scheduling for one UE 100 in a first period.
　ＢＳ３１０は、優先度順に第１の期間における無線リソースをＵＥ１００へ割り当ててもよい。すなわち、ＢＳ３１０は、スケジューリングが実行されていないＵＥ１００のうち、最も優先度が高いＵＥ１００へのスケジューリングを実行してもよい。具体的には、ＢＳ３１０は、ＵＥ１００へ無線リソースを割り当てる。ＢＳ３１０は、当該ＵＥ１００をＢＦ対象ＵＥとして選択するか否かを判定してもよい。或いは、ＢＳ３１０は、スケジューリングを実行する前に、第１期間におけるＢＦ対象ＵＥを予め選択していてもよい。 The BS 310 may allocate radio resources in the first period to the UE 100 in order of priority. That is, BS 310 may execute scheduling to UE 100 with the highest priority among UEs 100 for which scheduling has not been performed. Specifically, the BS 310 allocates radio resources to the UE 100. The BS 310 may determine whether to select the UE 100 as a BF target UE. Alternatively, the BS 310 may pre-select the BF target UE in the first period before performing scheduling.
　ステップＳ２２０において、ＢＳ３１０は、第１期間において割り当てるべき無線リソースがあるか否かを判定する。 In step S220, the BS 310 determines whether there is a radio resource to be allocated in the first period.
　ＢＳ３１０は、第１期間において割り当てるべき無線リソースがある場合、ステップＳ２３０の処理を実行する。従って、ＢＳ３１０は、第１期間において無線リソースを全て利用完了した場合（第１期間において利用可能な無線リソースがない場合）、ステップＳ２３０の処理を実行する。そうでない場合、ＢＳ３１０は、第１期間におけるスケジューリング処理を終了する。 If there is a radio resource to be allocated in the first period, the BS 310 executes the process of step S230. Therefore, the BS 310 executes the process of step S230 when the use of all radio resources in the first period is completed (when there is no available radio resource in the first period). Otherwise, the BS 310 ends the scheduling process in the first period.
　ステップＳ２３０において、ＢＳ３１０は、第１期間において無線リソースを割り当てられたＢＦ対象ＵＥの数が、許容ＵＥ数に達したか否かを判定する。 In step S230, the BS 310 determines whether the number of BF target UEs to which radio resources are allocated in the first period has reached the allowable number of UEs.
　ＢＳ３１０は、ステップＳ２１０においてスケジューリングを行ったＵＥ１００がＢＦ対象ＵＥである場合には、第１期間において無線リソースを割り当てられたＢＦ対象ＵＥの数に１を加えて、許容ＵＥ数に達したか否かを判定する。ステップＳ２１０においてスケジューリングを行ったＵＥ１００がＢＦ対象ＵＥでない場合には、ステップＳ２３０の処理を行わずに、ステップＳ２１０の処理を実行してもよい。 If the UE 100 scheduled in step S210 is a BF target UE, the BS 310 adds 1 to the number of BF target UEs to which radio resources are allocated in the first period, and reaches the allowable number of UEs. Determine if When the UE 100 that has performed scheduling in step S210 is not a BF target UE, the process of step S210 may be performed without performing the process of step S230.
　ＢＳ３１０は、第１期間において無線リソースを割り当てられたＢＦ対象ＵＥの数が、許容ＵＥ数に達した場合には、ステップＳ２４０の処理を実行する。ＢＳ３１０は、第１期間において無線リソースを割り当てられたＢＦ対象ＵＥの数が、許容ＵＥ数に達していない場合には、ステップＳ２１０の処理を実行する。 When the number of BF target UEs to which radio resources are allocated in the first period reaches the allowable number of UEs, the BS 310 executes the process of step S240. If the number of BF target UEs to which radio resources have been allocated in the first period has not reached the allowable number of UEs, the BS 310 executes the process of step S210.
　ステップＳ２４０において、ＢＳ３１０は、ＢＦ対象ＵＥの数が許容ＵＥ数に達した場合には、第１の期間における無線リソースのうち未割り当ての無線リソース（空きリソース）を、非ＢＦ対象ＵＥへ割り当てる。これにより、無線リソースを有効活用することができる。 In step S240, when the number of BF target UEs has reached the allowable number of UEs, the BS 310 allocates an unassigned radio resource (vacant resource) among the radio resources in the first period to the non-BF target UE. This makes it possible to use wireless resources effectively.
　ＢＳ３１０は、非ＢＦ対象ＵＥのうち、最も優先度が高いＵＥ１００へのスケジューリングを実行してもよい。ＢＳ３１０は、ステップＳ２４０の処理を実行する場合に、スケジューリングが実行されていないＵＥ１００の中から、非ＢＦ対象ＵＥを選択してもよい。 The BS 310 may perform scheduling for the highest priority UE 100 among non-BF target UEs. When performing the process of step S240, the BS 310 may select a non-BF target UE from among the UEs 100 for which scheduling has not been performed.
　ステップＳ２５０は、ステップＳ２２０と同じ処理である。 Step S250 is the same process as step S220.
　以上のように、ＢＳ３１０は、第１の期間における無線リソースを割り当てる度に、第１期間において無線リソースを割り当てられたＢＦ対象ＵＥの数が、許容ＵＥ数に達したか否かを判定する。これにより、ＢＦ対象ＵＥの数が許容ＵＥ数を超えなければ、通常のスケジューリング（例えば、優先度制御を伴うスケジューリング）と同じスケジューリングであるため、ＢＳ３１０は、適切にスケジューリングを実行可能である。さらに、無線リソースの割り当て対象が変更されないため、無駄になる可能性があるスケジューリング処理を低減できる。 As described above, every time the BS 310 allocates radio resources in the first period, it determines whether the number of BF target UEs allocated radio resources in the first period has reached the allowable number of UEs. By this means, if the number of BF target UEs does not exceed the allowable number of UEs, the BS 310 can execute scheduling appropriately, since it is the same scheduling as normal scheduling (for example, scheduling with priority control). Furthermore, since the allocation target of the radio resource is not changed, it is possible to reduce the scheduling process that may be wasted.
　（動作例３）
　動作例３について、図７を用いて説明する。図７は、実施形態に係る動作例３を説明するための図である。上述と同様の部分は、説明を省略する。 (Operation example 3)
Operation example 3 will be described with reference to FIG. FIG. 7 is a diagram for explaining an operation example 3 according to the embodiment. The same parts as those described above will not be described.
　動作例３では、ＢＳ３１０は、ＢＦ対象ＵＥを非ＢＦ対象ＵＥよりも優先的にスケジューリングする。 In the operation example 3, the BS 310 schedules BF target UEs preferentially to non-BF target UEs.
　図７に示すように、ステップＳ３１０において、ＢＳ３１０は、第１期間においてスケジューリングすべき（無線リソースを割り当てるべき）ＵＥ１００の中から、ＢＦ対象ＵＥを選択（決定）する。ＢＳ３１０は、複数のＢＦ対象ＵＥを選択してもよい。ＢＳ３１０は、１つのＢＦ対象ＵＥを選択してもよい。 As shown in FIG. 7, in step S310, the BS 310 selects (determines) a BF target UE from the UEs 100 to which scheduling (to allocate a radio resource) is to be performed in the first period. The BS 310 may select multiple BF target UEs. The BS 310 may select one BF target UE.
　ステップＳ３２０において、ＢＳ３１０は、選択されたＢＦ対象ＵＥの中から、１つのＵＥ１００に対する第１期間におけるスケジューリングを実行する。従って、ＢＳ３１０は、非ＢＦ対象ＵＥよりも先に、第１の期間における無線リソースをＢＦ対象ＵＥへ割り当てる。これにより、ＢＦ対象ＵＥへより確実にビームフォーミングを適用できる。 In step S320, the BS 310 performs scheduling for one UE 100 in a first period from among the selected BF target UEs. Therefore, the BS 310 allocates the radio resource in the first period to the BF target UE earlier than the non-BF target UE. Thus, beamforming can be applied more reliably to the BF target UE.
　ＢＳ３１０は、優先度順に第１の期間における無線リソースをＢＦ対象ＵＥへ割り当ててもよい。すなわち、ＢＳ３１０は、無線リソースが割り当てられていないＢＦ対象ＵＥのうちで、最も優先度が高いＵＥ１００へのスケジューリングを実行してもよい。 The BS 310 may allocate radio resources in the first period to the BF target UE in order of priority. That is, BS310 may perform scheduling to UE100 with the highest priority among BF target UEs to which radio resources are not allocated.
　ステップＳ３３０は、ステップＳ２１０に対応する。 Step S330 corresponds to step S210.
　ステップＳ３４０において、ＢＳ３１０は、全てのＢＦ対象ＵＥへ無線リソースを割り当てたか否かを判定する。ＢＳ３１０は、全てのＢＦ対象ＵＥへ無線リソースを割り当てた場合には、ステップＳ３６０の処理を実行する。ＢＳ３１０は、無線リソースを割り当てていないＢＦ対象ＵＥが存在する場合には、ステップＳ３５０の処理を実行する。 In step S340, the BS 310 determines whether radio resources have been allocated to all the BF target UEs. When the BS 310 assigns radio resources to all the BF target UEs, the BS 310 executes the process of step S360. If there is a BF target UE to which no radio resource has been allocated, the BS 310 executes the process of step S350.
　ステップＳ３５０は、ステップＳ２３０に対応する。ＢＳ３１０は、第１期間において無線リソースを割り当てられたＢＦ対象ＵＥの数が、許容ＵＥ数に達した場合には、ステップＳ３６０の処理を実行する。ＢＳ３１０は、第１期間において無線リソースを割り当てられたＢＦ対象ＵＥの数が、許容ＵＥ数に達していない場合には、ステップＳ３２０の処理を実行する。 Step S350 corresponds to step S230. When the number of BF target UEs to which radio resources are allocated in the first period reaches the allowable number of UEs, the BS 310 executes the process of step S360. If the number of BF target UEs to which radio resources are allocated in the first period has not reached the allowable number of UEs, the BS 310 executes the process of step S320.
　ステップＳ３６０は、ステップＳ１５０に対応する。 Step S360 corresponds to step S150.
　以上のように、ＢＳ３１０は、非ＢＦ対象ＵＥよりも先に、第１の期間における無線リソースをＢＦ対象ＵＥに割り当てる。これにより、ＢＦ対象ＵＥへより確実にビームフォーミングを適用できる。 As described above, the BS 310 allocates the radio resource in the first period to the BF target UE earlier than the non-BF target UE. Thus, beamforming can be applied more reliably to the BF target UE.
　［その他実施形態］
　上記のように実施形態について記載したが、この開示の一部をなす論述及び図面はこの開示を限定するものであると理解すべきではない。この開示から当業者には様々な代替実施形態、実施例及び運用技術が明らかとなる。 [Other embodiments]
Although the embodiment has been described as described above, it should not be understood that the statements and drawings that form a part of this disclosure limit this disclosure. Various alternative embodiments, examples and operation techniques will be apparent to those skilled in the art from this disclosure.
　上述において、ＢＳ３１０は、第１の期間における無線リソースの割り当てを行う前に、ＢＦ対象ＵＥの数が許容ＵＥ数を超えるか否かを判定してもよい。例えば、ＢＳ３１０は、第１の期間における無線リソースの割り当ての候補のＵＥ１００を決定した後に、ＢＦ対象ＵＥの数が許容ＵＥ数を超えるか否かを判定してもよい。これにより、ＢＳ３１０は、ＢＦ対象ＵＥの数が許容ＵＥ数を超える場合には、第１の期間における無線リソースの割り当てを行ったＵＥ１００を第２の期間における無線リソースの割り当て対象に変更することを抑制できるため、無駄になる可能性がある処理を低減できる。 In the above, the BS 310 may determine whether the number of BF target UEs exceeds the allowable number of UEs, before performing radio resource allocation in the first period. For example, after determining the candidate UEs 100 of the allocation of radio resources in the first period, the BS 310 may determine whether the number of BF target UEs exceeds the allowable number of UEs. Thereby, when the number of BF target UEs exceeds the number of allowable UEs, the BS 310 changes the UE 100 to which the radio resources have been allocated in the first period to the allocation target of the radio resources in the second period. Since it can be suppressed, processing that may be wasted can be reduced.
　動作例３において、ＢＳ３１０は、ＢＦ対象ＵＥの数が許容ＵＥ数を超えないように、第１期間においてスケジューリングすべきＵＥ１００の中から、ＢＦ対象ＵＥを選択（決定）してもよい。 In the operation example 3, the BS 310 may select (determine) the BF target UE from the UEs 100 to be scheduled in the first period so that the number of BF target UEs does not exceed the allowable number of UEs.
　上述において、ＢＳ３１０は、動作例１－３のスケジューリング方法のうち、いずれかのスケジューリング方法を選択してもよい。 In the above, the BS 310 may select one of the scheduling methods of the operation example 1-3.
　ＢＳ３１０は、ＢＦ対象ＵＥの数に応じて、スケジューリング方法を選択してもよい。例えば、ＢＳ３１０は、第１の期間における無線リソースの割り当てを行う前に、第１の期間においてＢＦ対象ＵＥの数が許容ＵＥ数を超えるか否かを判定してもよい。 The BS 310 may select a scheduling method according to the number of BF target UEs. For example, the BS 310 may determine whether the number of BF target UEs exceeds the allowable number of UEs in the first period before performing radio resource allocation in the first period.
　ＢＳ３１０は、ＢＦ対象ＵＥの数が許容ＵＥ数を超えない場合には、動作例１又は３に係るスケジューリング方法を選択してもよい。ＢＳ３１０は、ＢＦ対象ＵＥの数が許容ＵＥ数を超える場合には、動作例２に係るスケジューリング方法を選択してもよい。 The BS 310 may select the scheduling method according to the operation example 1 or 3 when the number of BF target UEs does not exceed the allowable number of UEs. The BS 310 may select the scheduling method according to the operation example 2 when the number of BF target UEs exceeds the allowable number of UEs.
　ＢＳ３１０は、同様に、ＣＥモードのＵＥの数及びＬＰＷＡ通信装置１００の数に応じて、スケジューリング方法を選択してもよい。 Similarly, the BS 310 may select a scheduling method according to the number of UEs in CE mode and the number of LPWA communication devices 100.
　実施形態において、ＬＰＷＡ方式がｅＭＴＣ方式又はＮＢ－ＩｏＴ方式である一例について説明したが、ｅＭＴＣ方式及びＮＢ－ＩｏＴ方式以外のＬＰＷＡ方式を利用してもよい。 In the embodiment, an example in which the LPWA method is the eMTC method or the NB-IoT method has been described, but an LPWA method other than the eMTC method and the NB-IoT method may be used.
　上述した実施形態に係る内容は、適宜組み合わせて実行されてもよい。また、上述した各シーケンスにおいて、必ずしも全ての動作が必須の構成ではない。例えば、各シーケンスにおいて、一部の動作のみが実行されてもよい。 The contents according to the above-described embodiments may be appropriately combined and executed. Further, in each sequence described above, not all operations are necessarily required. For example, in each sequence, only some operations may be performed.
　なお、日本国特許出願第２０１７‐２４４７６８号（２０１７年１２月２１日出願）の全内容が、参照により、本願に組み込まれている。 The entire content of Japanese Patent Application No. 2017-244768 (filed on December 21, 2017) is incorporated herein by reference.

Claims (8)

  1. 　基地局であって、
    　前記基地局の制御下における複数の無線通信装置の中からビームフォーミングが適用される対象装置を選択するよう構成される制御部を備え、
    　前記制御部は、セルのカバレッジを拡張するためのカバレッジ拡張モードの所定装置を前記対象装置として選択するよう構成される基地局。     A base station,
    A control unit configured to select a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station;
    A base station configured to select, as the target device, a predetermined device in a coverage extension mode for extending the coverage of a cell.
  2. 　前記制御部は、
    　　第１の期間において前記ビームフォーミングを適用すべき候補対象装置の数が、前記第１の期間において許容される前記対象装置の上限数を超えたか否かを判定し、　　前記候補対象装置の数が前記上限数を超えた場合には、前記候補対象装置のうち、前記対象装置として選択された前記所定装置を、前記第１の期間よりも後の第２の期間における無線リソースの割り当て対象に変更するよう構成される請求項１に記載の基地局。     The control unit
    It is determined whether or not the number of candidate target devices to which the beamforming should be applied in the first period exceeds the upper limit number of target devices allowed in the first period, and the number of candidate target devices is When the upper limit number is exceeded, the predetermined device selected as the target device among the candidate target devices is changed to a wireless resource allocation target in a second period after the first period. The base station of claim 1 configured to:
  3. 　前記制御部は、前記第１の期間における無線リソースの割り当てを行った後に、前記対象装置の数が前記上限数を超えるか否かを判定するよう構成される請求項２に記載の基地局。 The base station according to claim 2, wherein the control unit is configured to determine whether the number of target devices exceeds the upper limit number after performing the allocation of radio resources in the first period.
  4. 　前記制御部は、前記第２の期間における無線リソースの割り当て対象に変更された前記所定装置に割り当てられていた前記第１の期間における無線リソースを、前記ビームフォーミングが適用されない非対象装置に割り当てるよう構成される請求項３に記載の基地局。 The control unit may allocate the radio resource in the first period allocated to the predetermined device changed to the allocation target of the radio resource in the second period to the non-target device to which the beamforming is not applied. The base station of claim 3 configured.
  5. 　前記制御部は、
    　　第１の期間における無線リソースを無線通信装置に割り当てる度に、前記無線リソースが割り当てられた対象装置の数が、前記第１の期間において許容される前記対象装置の上限数に達したか否かを判定し、
    　　前記対象装置の数が前記上限数に達した場合には、前記第１の期間における無線リソースのうち未割り当ての無線リソースを、前記ビームフォーミングが適用されない非対象装置に割り当てるよう構成される請求項１に記載の基地局。     The control unit
    Every time when the radio resource in the first period is allocated to the radio communication device, whether or not the number of the target devices to which the radio resource is allocated has reached the upper limit number of the target devices allowed in the first period To determine
    When the number of target devices reaches the upper limit number, unassigned wireless resources among the wireless resources in the first period are allocated to non-target devices to which the beamforming is not applied. The base station according to 1.
  6. 　前記制御部は、前記ビームフォーミングが適用されない非対象装置よりも先に、第１の期間における無線リソースを前記対象装置に割り当てるよう構成される請求項１に記載の基地局。 The base station according to claim 1, wherein the control unit is configured to allocate a radio resource in a first period to the target device prior to an untargeted device to which the beamforming is not applied.
  7. 　基地局を制御するためのプロセッサであって、
    　前記基地局の制御下における複数の無線通信装置の中からビームフォーミングが適用される対象装置を選択する処理と、
    　制御部は、セルのカバレッジを拡張するためのカバレッジ拡張モードの所定装置を前記対象装置として選択する処理と、を実行するプロセッサ。     A processor for controlling a base station,
    A process of selecting a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station;
    A control unit that executes a process of selecting a predetermined device in a coverage extension mode for extending the coverage of a cell as the target device.
  8. 　通信方法であって、
    　基地局は、前記基地局の制御下における複数の無線通信装置の中からビームフォーミングが適用される対象装置を選択するステップを備え、
    　前記選択するステップにおいて、前記基地局は、セルのカバレッジを拡張するためのカバレッジ拡張モードの所定装置を前記対象装置として選択する、通信方法。     A communication method,
    The base station comprises a step of selecting a target apparatus to which beamforming is applied from among a plurality of wireless communication apparatuses under control of the base station,
    The communication method, wherein in the selecting step, the base station selects, as the target device, a predetermined device in a coverage extension mode for extending cell coverage.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011041001A (en) * 2009-08-11 2011-02-24 Samsung Yokohama Research Institute Co Ltd Radio base station, and radio communication method
JP2015008378A (en) * 2013-06-25 2015-01-15 京セラ株式会社 Base station, communication control method, and processor
JP2017157920A (en) * 2016-02-29 2017-09-07 岩崎通信機株式会社 Radio communication system and radio communication method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011041001A (en) * 2009-08-11 2011-02-24 Samsung Yokohama Research Institute Co Ltd Radio base station, and radio communication method
JP2015008378A (en) * 2013-06-25 2015-01-15 京セラ株式会社 Base station, communication control method, and processor
JP2017157920A (en) * 2016-02-29 2017-09-07 岩崎通信機株式会社 Radio communication system and radio communication method

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