JP2014233012A - User terminal, base station, and processor - Google Patents

Abstract

The present invention provides a user terminal, a base station, and a processor that allow a network to know the amount of data transmitted and received in D2D communication. A user terminal is a user terminal in a mobile communication system that supports D2D communication that is direct inter-terminal communication performed using radio resources allocated from a base station. The user terminal has at least one of a control unit that performs the D2D communication using the radio resource and a data amount transmitted or received in the D2D communication in a state where a connection between the user terminal and the base station is established. A transmission unit that transmits the data amount information indicated to the base station. [Selection] Figure 8

Description

  The present invention relates to a user terminal, a base station, and a processor in a mobile communication system that supports D2D communication.

  In 3GPP (3rd Generation Partnership Project), which is a standardization project for mobile communication systems, introduction of inter-terminal (Device to Device: D2D) communication is being studied as a new function after Release 12 (see Non-Patent Document 1).

  In D2D communication, a plurality of adjacent user terminals perform direct communication without going through a base station. That is, the data path of D2D communication does not go through the base station. On the other hand, a data path for normal communication (cellular communication) of a mobile communication system passes through a base station.

3GPP Technical Report “TR 22.803 V1.1.0” November 2012

  Since the data path of the cellular communication passes through the base station, the network including the base station can know the amount of data transmitted and received in the cellular communication.

  However, since the data path of D2D communication does not go through the base station, the network cannot know the amount of data transmitted and received in D2D communication. For this reason, for example, there is a problem that a charge plan that charges based on the amount of data transmitted and received in D2D communication cannot be realized.

  Therefore, the present invention provides a user terminal, a base station, and a processor that allow a network to know the amount of data transmitted and received in D2D communication.

  According to one embodiment, the user terminal is a user terminal in a mobile communication system that supports D2D communication, which is direct inter-terminal communication performed using radio resources allocated from a base station. The user terminal has at least one of a control unit that performs the D2D communication using the radio resource and a data amount transmitted or received in the D2D communication in a state where a connection between the user terminal and the base station is established. A transmission unit that transmits the data amount information indicated to the base station.

  According to the base station, the user terminal, and the processor according to the present invention, the network can know the amount of data transmitted and received in D2D communication.

FIG. 1 is a configuration diagram of an LTE system. FIG. 2 is a block diagram of the UE. FIG. 3 is a block diagram of the eNB. FIG. 4 is a protocol stack diagram of a radio interface in the LTE system. FIG. 5 is a configuration diagram of a radio frame used in the LTE system. FIG. 6 is a diagram illustrating a data path in cellular communication. FIG. 7 is a diagram illustrating a data path in D2D communication. FIG. 8 is a sequence diagram showing an operation example of the mobile communication system according to the first embodiment. FIG. 9 is a sequence diagram showing an operation example of the mobile communication system according to the second embodiment. FIG. 10 is a sequence diagram showing an operation example of the mobile communication system according to the third embodiment.

[Outline of Embodiment]
The user terminals according to the first to third embodiments are user terminals in a mobile communication system that supports D2D communication, which is direct inter-terminal communication performed using radio resources allocated from a base station. The user terminal has at least one of a control unit that performs the D2D communication using the radio resource and a data amount transmitted or received in the D2D communication in a state where a connection between the user terminal and the base station is established. A transmission unit that transmits the data amount information indicated to the base station.

  In 1st Embodiment, the said user terminal is further provided with the receiving part which receives the period information which shows the period in which the said user terminal transmits the said data amount information from the said base station. The transmission unit transmits the data amount information based on the period information.

  In 2nd Embodiment, the said user terminal is further provided with the receiving part which receives the request | requirement in which the said user terminal transmits the said data amount information from the said base station. The transmission unit transmits the data amount information based on the request.

  In the user terminal according to the third embodiment, the control unit includes a transmission buffer dedicated to D2D that holds untransmitted data that is data waiting to be transmitted in the D2D communication, and the transmission unit is a buffer related to the transmission buffer. The data amount information is transmitted together with the status report.

  In the user terminal according to the first to third embodiments, the transmission unit uses, as the data amount information, a ratio of used radio resources used by the user terminal in the D2D communication to the radio resources allocated from the base station. Radio resource usage rate is transmitted.

  In the user terminal according to the first to third embodiments, the control unit converts the data amount into the index using a table in which the data amount and the index are associated with each other, and the transmission unit transmits the data The index is transmitted as quantity information.

  In the user terminal according to another embodiment, the transmission unit transmits the data amount information on behalf of the user terminal and another user terminal that performs the D2D communication with the user terminal.

  The base station according to the first to third embodiments is a base station in a mobile communication system that supports D2D communication that is direct inter-terminal communication performed using radio resources allocated from the base station. The base station allocates the radio resource to the user terminal in a state where the connection between the user terminal and the base station is established, and controls the D2D communication, and the user terminal transmits in the D2D communication Or a receiving unit that receives data amount information indicating at least one of the received data amounts from the user terminal.

  In 1st Embodiment, the said base station is further provided with the transmission part which transmits the period information which shows the period when the said user terminal transmits the said data amount information to the said user terminal, The said receiving part is based on the said period information. And receiving the data amount information.

  In the second embodiment, the base station further includes a transmission unit that requests the user terminal to transmit the data amount information.

  In the base station according to the third embodiment, the receiving unit transmits the data amount information to the user terminal together with a buffer status report related to a D2D dedicated transmission buffer that holds untransmitted data that is data to be transmitted in the D2D communication The control unit allocates the radio resource to the user terminal based on the data amount information and the buffer status report.

  In the base station according to the first to third embodiments, the reception unit uses, as the data amount information, a ratio of used radio resources used by the user terminal in the D2D communication to the radio resources allocated from the base station. The control unit calculates the amount of data using the radio resource usage rate and the radio resource allocated to the user terminal.

  In the base station according to the first to third embodiments, the reception unit receives an index as the data amount information, and the control unit associates the index, the data amount, and the index. The data amount is calculated using a table.

  A processor according to the first to third embodiments is a processor provided in a user terminal in a mobile communication system that supports D2D communication that is direct inter-terminal communication performed using radio resources allocated from a base station. The processor performs a process of performing the D2D communication using the radio resource in a state where a connection between the user terminal and the base station is established, and at least one of data amounts transmitted or received in the D2D communication A process of transmitting the indicated data amount information to the base station is executed.

  Hereinafter, each embodiment in the case of introducing D2D communication into a cellular mobile communication system (hereinafter referred to as “LTE system”) configured in accordance with the 3GPP standard will be described with reference to the drawings.

[First Embodiment]
(LTE system)
FIG. 1 is a configuration diagram of an LTE system according to the present embodiment.

  1, the LTE system includes a plurality of UEs (User Equipment) 100, an E-UTRAN (Evolved Universal Terrestrial Radio Access Network) 10, and an EPC (Evolved Packet Core) 20. The E-UTRAN 10 and the EPC 20 constitute a network.

  The UE 100 is a mobile radio communication device, and performs radio communication with a cell (serving cell) that has established a connection. UE100 is corresponded to a user terminal.

  The E-UTRAN 10 includes a plurality of eNBs 200 (evolved Node-B). The eNB 200 corresponds to a base station. The eNB 200 manages a cell and performs radio communication with the UE 100 that has established a connection with the cell.

  Note that “cell” is used as a term indicating a minimum unit of a radio communication area, and is also used as a term indicating a function of performing radio communication with the UE 100.

  The eNB 200 has, for example, a radio resource management (RRM) function, a user data routing function, and a measurement control function for mobility control and scheduling.

  The EPC 20 includes MME (Mobility Management Entity) / S-GW (Serving-Gateway) 300 and OAM 400 (Operation and Maintenance). The EPC 20 corresponds to a core network.

  The MME is a network node that performs various types of mobility control for the UE 100, and corresponds to a control station. The S-GW is a network node that performs transfer control of user data, and corresponds to an exchange.

  The eNB 200 is connected to each other via the X2 interface. Moreover, eNB200 is connected with MME / S-GW300 via S1 interface.

  The OAM 400 is a server device managed by an operator, and performs maintenance and monitoring of the E-UTRAN 10.

  Next, configurations of the UE 100 and the eNB 200 will be described.

  FIG. 2 is a block diagram of the UE 100. As shown in FIG. 2, the UE 100 includes an antenna 101, a radio transceiver 110, a user interface 120, a GNSS (Global Navigation Satellite System) receiver 130, a battery 140, a memory 150, and a processor 160. Have. The memory 150 and the processor 160 constitute a control unit.

  The UE 100 may not have the GNSS receiver 130. Alternatively, the memory 150 may be integrated with the processor 160, and this set (ie, chip set) may be used as the processor 160 '.

  The antenna 101 and the wireless transceiver 110 are used for transmitting and receiving wireless signals. The antenna 101 includes a plurality of antenna elements. The radio transceiver 110 converts the baseband signal output from the processor 160 into a radio signal and transmits it from the antenna 101. Further, the radio transceiver 110 converts a radio signal received by the antenna 101 into a baseband signal and outputs the baseband signal to the processor 160.

  The user interface 120 is an interface with a user who owns the UE 100, and includes, for example, a display, a microphone, a speaker, and various buttons. The user interface 120 receives an operation from the user and outputs a signal indicating the content of the operation to the processor 160.

  The GNSS receiver 130 receives a GNSS signal and outputs the received signal to the processor 160 in order to obtain location information indicating the geographical location of the UE 100.

  The battery 140 stores power to be supplied to each block of the UE 100.

  The memory 150 stores a program executed by the processor 160 and information used for processing by the processor 160.

  In the present embodiment, the memory 150 has a D2D-dedicated transmission buffer that holds untransmitted data that is data waiting to be transmitted in D2D communication.

  The processor 160 includes a baseband processor that modulates / demodulates and encodes / decodes a baseband signal, and a CPU (Central Processing Unit) that executes programs stored in the memory 150 and performs various processes. . The processor 160 may further include a codec that performs encoding / decoding of an audio / video signal. The processor 160 executes various processes and various communication protocols described later.

  FIG. 3 is a block diagram of the eNB 200. As illustrated in FIG. 3, the eNB 200 includes an antenna 201, a radio transceiver 210, a network interface 220, a memory 230, and a processor 240. The memory 230 and the processor 240 constitute a control unit. The memory 230 may be integrated with the processor 240, and this set (that is, a chip set) may be used as the processor 240 '.

  The antenna 201 and the wireless transceiver 210 are used for transmitting and receiving wireless signals. The antenna 201 includes a plurality of antenna elements. The wireless transceiver 210 converts the baseband signal output from the processor 240 into a wireless signal and transmits it from the antenna 201. In addition, the radio transceiver 210 converts a radio signal received by the antenna 201 into a baseband signal and outputs the baseband signal to the processor 240.

  The network interface 220 is connected to the neighboring eNB 200 via the X2 interface and is connected to the MME / S-GW 300 via the S1 interface. The network interface 220 is used for communication performed on the X2 interface and communication performed on the S1 interface.

  The memory 230 stores a program executed by the processor 240 and information used for processing by the processor 240.

  The processor 240 includes a baseband processor that performs modulation / demodulation and encoding / decoding of a baseband signal, and a CPU that executes a program stored in the memory 230 and performs various processes. The processor 240 executes various processes and various communication protocols described later.

  FIG. 4 is a protocol stack diagram of a radio interface in the LTE system.

  As shown in FIG. 4, the radio interface protocol is divided into layers 1 to 3 of the OSI reference model, and layer 1 is a physical (PHY) layer. Layer 2 includes a MAC (Media Access Control) layer, an RLC (Radio Link Control) layer, and a PDCP (Packet Data Convergence Protocol) layer. Layer 3 includes an RRC (Radio Resource Control) layer.

  The physical layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. The physical layer provides a transmission service to an upper layer using a physical channel. Data is transmitted between the physical layer of the UE 100 and the physical layer of the eNB 200 via a physical channel.

  The MAC layer performs data priority control, retransmission processing by hybrid ARQ (HARQ), and the like. Data is transmitted via the transport channel between the MAC layer of the UE 100 and the MAC layer of the eNB 200. The MAC layer of the eNB 200 includes a MAC scheduler that determines an uplink / downlink transport format (transport block size, modulation / coding scheme, and the like) and an allocated resource block.

  The RLC layer transmits data to the RLC layer on the receiving side using functions of the MAC layer and the physical layer. Data is transmitted between the RLC layer of the UE 100 and the RLC layer of the eNB 200 via a logical channel.

  The PDCP layer performs header compression / decompression and encryption / decryption.

  The RRC layer is defined only in the control plane. Control signals (RRC messages) for various settings are transmitted between the RRC layer of the UE 100 and the RRC layer of the eNB 200. The RRC layer controls the logical channel, the transport channel, and the physical channel according to establishment, re-establishment, and release of the radio bearer. If there is an RRC connection between the RRC of the UE 100 and the RRC of the eNB 200, the UE 100 is in a connected state, otherwise, the UE 100 is in an idle state.

  A NAS (Non-Access Stratum) layer located above the RRC layer performs session management, mobility management, and the like.

  FIG. 5 is a configuration diagram of a radio frame used in the LTE system. In the LTE system, OFDMA (Orthogonal Frequency Division Multiplexing Access) is used for the downlink, and SC-FDMA (Single Carrier Frequency Multiple Access) is used for the uplink.

  As shown in FIG. 5, the radio frame is composed of 10 subframes arranged in the time direction, and each subframe is composed of two slots arranged in the time direction. The length of each subframe is 1 ms, and the length of each slot is 0.5 ms. Each subframe includes a plurality of resource blocks (RB) in the frequency direction and includes a plurality of symbols in the time direction. A guard interval called a cyclic prefix (CP) is provided at the head of each symbol. The resource block includes a plurality of subcarriers in the frequency direction. A radio resource unit composed of one subcarrier and one symbol is called a resource element (RE).

  Among radio resources allocated to the UE 100, a frequency resource can be specified by a resource block, and a time resource can be specified by a subframe (or slot).

  In the downlink, the section of the first few symbols of each subframe is a control region mainly used as a physical downlink control channel (PDCCH). The remaining section of each subframe is an area that can be used mainly as a physical downlink shared channel (PDSCH). Further, cell-specific reference signals (CRS) are distributed and arranged in each subframe.

  In the uplink, both ends in the frequency direction in each subframe are control regions mainly used as a physical uplink control channel (PUCCH). Further, the central portion in the frequency direction in each subframe is an area that can be used mainly as a physical uplink shared channel (PUSCH). Further, a demodulation reference signal (DMRS) and a sounding reference signal (SRS) are arranged in each subframe.

(D2D communication)
Next, normal communication (cellular communication) of the LTE system and D2D communication will be compared and described.

  FIG. 6 is a diagram illustrating a data path in cellular communication. Here, the case where cellular communication is performed between UE100-1 which established the connection with eNB200-1 and UE100-2 which established the connection with eNB200-2 is illustrated. A data path means a transfer path of user data (user plane).

  As shown in FIG. 6, the data path of the cellular communication goes through the network. Specifically, a data path that passes through the eNB 200-1, the S-GW 300, and the eNB 200-2 is set.

  FIG. 7 is a diagram illustrating a data path in D2D communication. Here, the case where D2D communication is performed between UE100-1 which established the connection with eNB200-1 and UE100-2 which established the connection with eNB200-2 is illustrated.

  For example, D2D communication is started when one UE 100 of UE 100-1 and UE 100-2 discovers the other UE 100 existing in the vicinity. In order to start D2D communication, the UE 100 has a function of discovering another UE 100 existing in the vicinity of the UE 100 (Discover). Further, the UE 100 has a (Discoverable) function that is discovered from other UEs 100.

  As shown in FIG. 7, the data path of D2D communication does not go through the network. That is, direct radio communication is performed between UEs. In this way, if the UE 100-2 exists in the vicinity of the UE 100-1, the network traffic load and the battery consumption of the UE 100 are reduced by performing D2D communication between the UE 100-1 and the UE 100-2. The effect of doing etc. is acquired.

(Schematic operation of the mobile communication system according to the first embodiment)
Next, schematic operation of the mobile communication system according to the first embodiment will be described with reference to FIG. FIG. 8 is a sequence diagram showing an operation example of the mobile communication system according to the first embodiment.

  In this embodiment, UE100-1 and UE100-2 have established the connection with the cell which eNB200 manages. The eNB 200 controls D2D communication between the UE 100-1 and the UE 100-2. Therefore, eNB200 allocates a radio | wireless resource in order for UE100-1 and UE100-2 to perform D2D communication, and transmits the scheduling information which shows the allocated radio | wireless resource to UE100-1 and UE100-2. UE100-1 and UE100-2 perform D2D communication using the allocated radio | wireless resource.

  As illustrated in FIG. 8, in step S101, the eNB 200, the UE 100-1, and the UE 100-2 execute a D2D setup process in order to perform D2D communication between the UE 100-1 and the UE 100-2.

  Specifically, the UE 100-1 and the UE 100-2 establish a D2D link between the UE 100-1 and the UE 100-2.

  Furthermore, eNB200 and UE100 (UE100-1 and UE100-2) set the radio bearer (D2D control radio bearer) used for control of D2D communication between eNB200 and UE100. This radio bearer for D2D control may be a dedicated radio bearer used only for D2D communication, or may be a shared radio bearer used for cellular communication and D2D communication.

  Each of the UE 100-1 and the UE 100-2 uses a radio bearer for D2D control, and QCI (QoS Class) which is an identifier of an application used in D2D communication or an identifier of communication quality required for the application (that is, QoS) IDIdentifier) is transmitted to the eNB 200. The eNB 200 allocates radio resources in D2D communication according to application identifiers or application characteristics based on QCI.

  For example, when the traffic by the application used for D2D communication is low load and temporary (for example, when it is a chat etc.), eNB200 allocates the radio | wireless resource shared with other D2D communication to D2D communication. As a result, radio resources can be saved.

  Moreover, when the traffic by the application used for D2D communication is high load and continuous (for example, when it is streaming etc.), eNB200 allocates a dedicated radio | wireless resource periodically to D2D communication. Thereby, a large amount of traffic can be transmitted in D2D communication.

  Furthermore, when traffic by an application used for D2D communication requires high load, continuous, and low delay (for example, video call), the eNB 200 transmits dedicated radio resources periodically and repeatedly. Assign as possible. Thereby, a large amount of traffic can be transmitted in D2D communication, and the reliability of communication can be increased. The repeated transmission is not limited to a method in which the same data is repeatedly transmitted a plurality of times, but may be a method in which redundant bits are changed each time transmission is performed (for example, an incremental redundancy method).

  For example, the eNB 200 can store a table in which an application identifier and its characteristics are associated in advance, and can grasp the application characteristics by using the table.

  Through the D2D setup, after establishing the D2D link, the UE 100-1 and the UE 100-2 start D2D communication using the allocated radio resources.

  In step S102, eNB200 transmits period information in order to make each of UE100-1 and UE100-2 transmit data amount information. Each of UE100-1 and UE100-2 receives period information.

  The period information indicates a period for transmitting the data amount information. For example, the period information instructs to transmit data amount information every time a predetermined time has elapsed since the start of D2D communication, or instructs to transmit data amount information every time a predetermined time comes. Information.

  The period information does not necessarily have to be a constant period, and may be information instructing to transmit the data amount information every time the data amount reaches a predetermined value, for example. Further, the period information may be information instructing transmission at a predetermined timing that the UE 100 and the eNB 200 recognize in advance.

  Data amount information will be described later.

  In step S103, each of the UE 100-1 and the UE 100-2 transmits data amount information to the eNB 200. eNB200 receives data amount information from each of UE100-1 and UE100-2.

  Each of the UE 100-1 and the UE 100-2 transmits data amount information to the eNB 200 at a timing indicated by the period information using the radio bearer for D2D control. The eNB 200 receives the data amount information from each of the UE 100-1 and the UE 100-2 at the timing indicated by the period information using the D2D control radio bearer.

  The data amount information indicates at least one of the data amounts transmitted or received in the D2D communication. Therefore, the data amount information indicates the amount of data transmitted in D2D communication, the amount of data received in D2D communication, or the amount of data transmitted / received in D2D communication. Hereinafter, the data amount in the D2D communication is appropriately referred to as a D2D data amount.

  Further, the data amount information may be one in which the D2D data amount is indicated by a direct value, or may be indicated by an indirect value corresponding to the D2D data amount.

  As an example indicated by an indirect value, the data amount information includes a radio resource usage rate (= used radio resource / allocation) that is a used radio resource ratio used by the UE 100-1 in the D2D communication with respect to the radio resource allocated from the eNB 200. Wireless resources). That is, each of UE100-1 and UE100-2 may transmit a radio | wireless resource usage rate as data amount information. In this case, the eNB 200 calculates the D2D data amount using the radio resource usage rate and the allocated radio resource.

  Moreover, when each of eNB200, UE100-1, and UE100-2 has memorize | stored the table with which D2D data amount and the index were matched, each of UE100-1 and UE100-2 is as data amount information, An index may be transmitted. That is, UE100-1 and UE100-2 convert the D2D data amount into an index using the said table, and transmit the said index to eNB200. When receiving the index, the eNB 200 calculates the D2D data amount using the received index and the stored table.

  In step S104, each of UE100-1 and UE100-2 transmits data amount information to eNB200 similarly to step S103. eNB200 receives data amount information from each of UE100-1 and UE100-2.

  Hereinafter, the process of step S104 is repeated until the D2D communication ends.

  When the eNB 200 receives the data amount information, the eNB 200 may transmit the data amount information to the host device of the eNB 200, or may hold the data amount information until a request is received from the host device of the eNB 200.

  As described above, the network including the eNB 200 and the host device of the eNB 200 can know the D2D data amount. As a result, for example, a charge plan that charges based on the amount of D2D data can be realized.

  In addition, each of UE100-1 and UE100-2 transmits data amount information using the radio bearer for D2D control, when D2D communication is complete | finished. Thereafter, the D2D control radio bearer is released.

(Summary of the first embodiment)
In this embodiment, each of UE100-1 and UE100-2 (radio | wireless transmitter / receiver 110) transmits data amount information to eNB200. eNB200 (radio | wireless transmitter / receiver 210) receives data amount information from each of UE100-1 and UE100-2. Thereby, eNB200 can know D2D data amount by receiving data amount information.

  Moreover, in this embodiment, eNB200 (radio | wireless transmitter / receiver 210) transmits period information to each of UE100-1 and UE100-2, and each of UE100-1 and UE100-2 (radio | wireless transmitter / receiver 110) is a period. Information is received from the eNB 200. Each of UE100-1 and UE100-2 transmits the data amount information from eNB200 based on period information, and eNB200 receives data amount information based on period information.

  Moreover, in this embodiment, each of UE100-1 and UE100-2 (radio | wireless transmitter / receiver 110) transmits a radio | wireless resource usage rate as data amount information. The eNB 200 (radio transceiver 210) receives the radio resource usage rate. The eNB 200 (control unit) calculates the data amount using the radio resource usage rate and the assigned radio resource. Thereby, the data amount of the data amount information transmitted / received between eNB200 and UE100 can be reduced.

  Moreover, in this embodiment, each of UE100-1 and UE100-2 (control part) converts D2D data amount into an index using the table with which D2D data amount and the index were matched. Each of UE100-1 and UE100-2 (radio | wireless transmitter / receiver 110) transmits the converted index as data amount information. eNB200 (radio | wireless transmitter / receiver 210) receives an index as data amount information. The eNB 200 (control unit) calculates the D2D data amount using an index, a table in which the D2D data amount and the index are associated with each other. Thereby, the data amount of the data amount information transmitted / received between eNB200 and UE100 can be reduced.

[Second Embodiment]
(Schematic operation of the mobile communication system according to the second embodiment)
Next, a schematic operation of the mobile communication system according to the second embodiment will be described with reference to FIG. FIG. 9 is a sequence diagram showing an operation example of the mobile communication system according to the second embodiment. In addition, it demonstrates centering on a different part from embodiment mentioned above, and abbreviate | omits description for the same part suitably.

  In 1st Embodiment mentioned above, eNB200 transmits period information to each of UE100-1 and UE100-2, and each of UE100-1 and UE100-2 transmits data amount information based on period information. It was. In this embodiment, each of UE100-1 and UE100-2 transmits data amount information based on the request | requirement from eNB200.

  As shown in FIG. 9, UE100-1 and UE100-2 are performing D2D communication.

  In step S201, eNB200 transmits the data amount request | requirement which requests | requires transmitting data amount information to each of UE100-1 and UE100-2. Each of UE100-1 and UE100-2 receives a data amount request.

  The eNB 200 can transmit a data amount request under a predetermined condition. For example, the eNB 200 transmits a data amount request when the traffic amount of the eNB 200 becomes a predetermined value or less. Moreover, eNB200 may transmit a data amount request | requirement, when D2D communication of UE100-1 and UE100-2 is complete | finished.

  In step S202, each of the UE 100-1 and the UE 100-2 transmits data amount information to the eNB 200 when receiving a data amount request. The eNB 200 receives the data amount information.

  In step S203, similarly to step S201, the eNB 200 transmits a data amount request to each of the UE 100-1 and the UE 100-2.

  In step S204, each of UE100-1 and UE100-2 transmits data amount information to eNB200 similarly to step S202.

  Thereafter, the processes in steps S203 and S204 are repeated until the D2D communication is completed.

(Summary of the second embodiment)
In this embodiment, eNB200 (radio | wireless transmitter / receiver 210) transmits a data amount request | requirement to each of UE100-1 and UE100-2. Each of UE100-1 and UE100-2 (radio | wireless transmitter / receiver 110) receives a data amount request | requirement, and transmits data amount information based on a data amount request | requirement. Thereby, eNB200 can control transmission of the data amount information of UE100-1 and UE100-2.

[Third Embodiment]
(Schematic operation of the mobile communication system according to the third embodiment)
Next, a schematic operation of the mobile communication system according to the third embodiment will be described with reference to FIG. FIG. 10 is a sequence diagram showing an operation example of the mobile communication system according to the third embodiment. In addition, it demonstrates centering on a different part from embodiment mentioned above, and abbreviate | omits description for the same part suitably.

  In embodiment mentioned above, UE100-1 and UE100-2 transmitted data amount information. In the present embodiment, the UE 100-1 and the UE 100-2 transmit a buffer status report in addition to the data amount information.

  As illustrated in FIG. 10, in step S301, each of the UE 100-1 and the UE 100-2 transmits data amount information to the eNB 200 together with the buffer status report. The eNB 200 receives the data amount information together with the buffer status report.

  Each of the UE 100-1 and the UE 100-2 has a transmission buffer dedicated to D2D that holds untransmitted data (transmission buffer retention amount) that is data waiting to be transmitted in D2D communication. The buffer status report (BSR) is a report regarding the transmission buffer.

  In step S302, eNB200 allocates the radio | wireless resource used for D2D communication to UE100-1 and UE100-2 based on data amount information and a buffer status report (performs scheduling).

  Specifically, the eNB 200 changes the allocated radio resource amount according to the D2D data amount indicated by the data amount information and the transmission buffer retention amount indicated by the buffer status report. For example, the eNB 200 periodically allocates dedicated radio resources when the D2D data amount is equal to or greater than the threshold value and the transmission buffer retention amount is equal to or greater than the threshold value. On the other hand, when the D2D data amount is less than the threshold value and the transmission buffer retention amount is less than the threshold value, the eNB 200 allocates a radio resource shared with another group performing D2D communication.

  In step S303, eNB200 transmits the scheduling information which shows the radio | wireless resource allocated based on data amount information and a buffer status report to each of UE100-1 and UE100-2. Each of UE100-1 and UE100-2 receives scheduling information.

  UE100-1 and UE100-2 perform D2D communication using the radio | wireless resource shown by the scheduling information.

  In step S304, each of UE100-1 and UE100-2 transmits data amount information to eNB200 with a buffer status report similarly to step S301.

  In step S305, as in step S302, the eNB 200 allocates radio resources used for D2D communication to the UE 100-1 and the UE 100-2 based on the data amount information and the buffer status report received in step S304.

  In step S306, similarly to step S303, the eNB 200 transmits scheduling information indicating the radio resource allocated in step S305 to each of the UE 100-1 and the UE 100-2.

  Thereafter, the processes in steps S304 to S306 are repeated until the D2D communication is completed.

(Summary of the third embodiment)
In this embodiment, each of UE100-1 and UE100-2 (control part) hold | maintains the transmission buffer only for D2D which hold | maintains a transmission buffer retention amount. Each of UE100-1 and UE100-2 (radio | wireless transmitter / receiver 110) transmits data amount information with a buffer status report. eNB200 (radio | wireless transmitter / receiver 210) receives data amount information with a buffer status report. eNB200 (control part) allocates a radio | wireless resource to UE100-1 and UE100-2 based on data amount information and a buffer status report. Thereby, since eNB200 can grasp | ascertain the D2D data amount which each UE100-1 and UE100-2 transmitted / received and the data amount transmitted from now on, a radio | wireless resource can be allocated appropriately.

[Other embodiments]
As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the first embodiment described above, the eNB 200 transmits the period information after the D2D setup is completed, but is not limited thereto. The eNB 200 may transmit period information during D2D setup.

  Moreover, in 1st Embodiment mentioned above, although each of UE100-1 and UE100-2 transmitted data amount information using the radio bearer, it is not restricted to this. For example, in each embodiment, the eNB 200 may transmit at least one of the above-described period information, data amount request, and scheduling information to each of the UE 100-1 and the UE 100-2 using the D2D control radio bearer. Moreover, in 3rd Embodiment, each of UE100-1 and UE100-2 may transmit data amount information with a buffer status report using the radio bearer for D2D control.

  Moreover, in each embodiment mentioned above, each of UE100-1 and UE100-2 transmitted data amount information, and eNB200 received data amount information from each of UE100-1 and UE100-2, It is not limited to this. For example, UE100-1 may transmit data amount information on behalf of UE100-1 and UE100-2. That is, the UE 100-1 is an anchor UE 100 that performs communication with the eNB 200 for D2D communication. Thereby, eNB200 can abbreviate | omit reception of the data amount information from UE100 other than anchor UE100, Therefore The load of eNB200 can be reduced.

  Further, when the anchor UE 100 exists, the eNB 200 only needs to set the D2D control radio bearer only with the anchor UE 100, and thus the load on the eNB 200 can be reduced.

  Note that the anchor UE 100 may receive not only data amount information but also scheduling information as a representative.

  In addition, in 3rd Embodiment mentioned above, although each of UE100-1 and UE100-2 transmitted data amount information and the buffer status report to eNB200, it is not restricted to this. Each of UE 100-1 and UE 100-2 may transmit a buffer status report (only) to eNB 200 instead of the data amount information.

  For example, each of the UE 100-1 and the UE 100-2 transmits a buffer status report to the eNB 200 every time the untransmitted data in the D2D communication held in the transmission buffer is updated. That is, each of the UE 100-1 and the UE 100-2 creates and transmits a buffer status report each time new untransmitted data that is not held in the transmission buffer is held when the previous buffer status report is created. The eNB 200 may estimate the data amount transmitted / received in the D2D communication by accumulating the data amount of the untransmitted data obtained by the buffer status report transmitted from each of the UE 100-1 and the UE 100-2.

  Note that information indicating untransmitted data in D2D communication is not information indicating at least one of data amounts already transmitted or received in D2D communication, and thus does not correspond to data amount information.

  DESCRIPTION OF SYMBOLS 10 ... E-UTRAN, 20 ... EPC, 100, 100-1, 100-2, 100-3 ... UE (user terminal), 101 ... Antenna, 110 ... Radio transceiver, 120 ... User interface, 130 ... GNSS receiver 140 ... battery 150 ... memory 160,160 '... processor 200,200-1,200-2,200-3 ... eNB (radio base station) 201 ... antenna 210 ... radio transceiver 220 ... network Interface 230 ... Memory 240, 240 '... Processor 300 ... MME / S-GW 400 ... OAM

Claims (14)

A user terminal in a mobile communication system that supports D2D communication that is direct inter-terminal communication performed using radio resources allocated from a base station,
A control unit that performs the D2D communication using the radio resource in a state where the connection between the user terminal and the base station is established;
A user terminal comprising: a transmission unit that transmits data amount information indicating at least one of data amounts transmitted or received in the D2D communication to the base station. A receiving unit for receiving, from the base station, period information indicating a period at which the user terminal transmits the data amount information;
The user terminal according to claim 1, wherein the transmission unit transmits the data amount information based on the period information. A receiving unit for receiving a request for transmitting the data amount information from the base station by the user terminal;
The user terminal according to claim 1, wherein the transmission unit transmits the data amount information based on the request. The control unit has a transmission buffer dedicated to D2D that holds untransmitted data that is data waiting for transmission in the D2D communication,
The said transmission part transmits the said data amount information with the buffer status report regarding the said transmission buffer, The user terminal of Claim 1 characterized by the above-mentioned.   The transmitting unit transmits, as the data amount information, a radio resource usage rate that is a ratio of used radio resources used by the user terminal in the D2D communication to the radio resources allocated from the base station. The user terminal according to claim 1. The control unit converts the data amount into the index using a table in which the data amount and the index are associated with each other,
The user terminal according to claim 1, wherein the transmission unit transmits the index as the data amount information.   The user terminal according to claim 1, wherein the transmission unit transmits the data amount information on behalf of the user terminal and another user terminal that performs the D2D communication with the user terminal. The base station in a mobile communication system that supports D2D communication, which is direct inter-terminal communication performed using radio resources allocated from a base station,
A control unit that controls the D2D communication by allocating the radio resource to the user terminal in a state where a connection between the user terminal and the base station is established;
A base station comprising: a receiving unit that receives, from the user terminal, data amount information indicating at least one of data amounts transmitted or received by the user terminal in the D2D communication. A transmission unit that transmits to the user terminal period information indicating a period at which the user terminal transmits the data amount information;
The base station according to claim 8, wherein the reception unit receives the data amount information based on the period information.   The base station according to claim 8, further comprising a transmission unit that requests the user terminal to transmit the data amount information. The receiving unit receives the data amount information from the user terminal together with a buffer status report related to a D2D-dedicated transmission buffer that holds untransmitted data that is data waiting to be transmitted in the D2D communication,
The base station according to claim 8, wherein the control unit allocates the radio resource to the user terminal based on the data amount information and the buffer status report. The receiving unit receives, as the data amount information, a radio resource usage rate that is a ratio of used radio resources used by the user terminal in the D2D communication to the radio resources allocated from the base station;
The base station according to claim 8, wherein the control unit calculates the amount of data using the radio resource usage rate and the radio resource allocated to the user terminal. The receiving unit receives an index as the data amount information,
The base station according to claim 8, wherein the control unit calculates the data amount using the index and a table in which the data amount and the index are associated with each other. A processor provided in a user terminal in a mobile communication system that supports D2D communication that is direct inter-terminal communication performed using radio resources allocated from a base station,
In a state in which a connection between the user terminal and the base station is established, a process of performing the D2D communication using the radio resource is executed.
A processor that executes a process of transmitting data amount information indicating at least one of data amounts transmitted or received in the D2D communication to the base station.

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