Communication control method

Abstract

SOLUTION: To provide a communication control method that includes setting, for first user equipment (UE) 100-1 and second UE 100-2, multiple routes via the UE 100-1 and the UE 100-2 for a radio bearer terminating at the gNB and UE 100-1 by a base station (gNB) 200, and communicating with the gNB using a first route between UE 100-1 and the gNB and communicating with the gNB using a second route between UE 100-2 and the gNB in accordance with the set routes by the UE 100-1 in a mobile communication system.EFFECT: To enable proper communication between multiple user devices and a base station.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a communication control method for use in a cellular communication system. [Background technology]

[0002] Packet duplication is defined in 3GPP (Third Generation Partnership Project) (registered trademark; the same applies below), a standardization project for cellular communication systems. Packet duplication is a technique in which a base station duplicates data (PDCP PDU (Packet Data Convergence Protocol-Protocol Data Unit)) and transmits the original data and the duplicated data to a user device. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS 38.300 V16.6.0 (2021-06) Summary of the Invention [Means for solving the problem]

[0004] A communication control method according to a first aspect includes a base station setting, for a first user equipment and a second user equipment, multiple routes via the first user equipment and the second user equipment for a radio bearer terminating at the base station and the first user equipment, and the first user equipment communicating with the base station using a first route between the first user equipment and the base station in accordance with the settings, and communicating with the base station using a second route between the second user equipment and the base station.

[0005] A communication control method according to a second aspect includes a base station setting, for a first user equipment and a second user equipment, multiple routes via the first user equipment and the second user equipment for a radio bearer terminating at the base station and the first user equipment, and the first user equipment communicating with the base station using a first route between the first user equipment and the base station in accordance with the settings, and communicating with the base station using a second route between the second user equipment and the base station. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a cellular communication system according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating an example of the configuration of a UE (user equipment) according to an embodiment. [Diagram 3] FIG. 3 is a diagram illustrating an example configuration of a gNB (base station) according to one embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of a protocol stack related to a user plane according to an embodiment. [Diagram 5] FIG. 5 is a diagram illustrating an example of the configuration of a protocol stack related to a control plane according to an embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of a synchronous PDCP entity according to the first embodiment. [Figure 7] FIG. 7 is a diagram illustrating a first operation example according to the first embodiment. [Figure 8] FIG. 8 is a diagram illustrating a second operation example according to the first embodiment. [Figure 9] FIG. 9 is a diagram illustrating a third operation example according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating a fourth operation example according to the first embodiment. [Figure 11] FIG. 11 is a diagram illustrating a fifth operation example according to the first embodiment. [Figure 12] FIG. 12 is a diagram illustrating an example of an inter-UE split bearer according to the first embodiment. [Figure 13] FIG. 13 is a diagram illustrating a first operation example according to the second embodiment. [Figure 14] FIG. 14 is a diagram illustrating an example of setting information of an inter-UE split bearer according to the second embodiment. [Figure 15] FIG. 15 is a diagram illustrating an example of setting information of an inter-UE split bearer according to the second embodiment. [Figure 16] FIG. 16 is a diagram illustrating a second operation example according to the second embodiment. [Figure 17] FIG. 17 is a diagram illustrating a third operation example according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] An object of the present invention is to provide a communication control method that enables appropriate communication between a plurality of user devices and a base station.

[0008] A cellular communication system according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0009] (Cellular Communication System) First, a configuration of a cellular communication system according to an embodiment will be described. The cellular communication system according to an embodiment is a 3GPP 5G system, but LTE may be applied at least partially to the cellular communication system. In addition, future cellular communication systems such as 6G may also be applied to the cellular communication system.

[0010] FIG. 1 is a diagram illustrating an example of the configuration of a cellular communication system 1 according to an embodiment.

[0011] As shown in FIG. 1, the cellular communication system 1 includes a user equipment (UE) 100, a 5G radio access network (NG-RAN) 10, and a 5G core network (5GC) 20.

[0012] The UE 100 is a mobile device. The UE 100 may be any device that is used by a user, and may be, for example, a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle (Vehicle UE), or an aircraft or a device provided in an aircraft (Aerial UE).

[0013] The NG-RAN 10 includes a base station (called "gNB" in the 5G system) 200. The gNB 200 is sometimes called an NG-RAN node. The gNBs 200 are connected to each other via an Xn interface, which is an interface between base stations. The gNB 200 manages one or more cells. The gNB 200 performs wireless communication with the UE 100 that has established a connection with its own cell. The gNB 200 has a radio resource management (RRM) function, a routing function for user data (hereinafter simply referred to as "data"), a measurement control function for mobility control and scheduling, and the like. The term "cell" is used to indicate the smallest unit of a wireless communication area. The term "cell" is also used to indicate a function or resource for wireless communication with the UE 100. One cell belongs to one carrier frequency.

[0014] In addition, the gNB may be connected to an EPC (Evolved Packet Core) which is a core network of LTE, and the LTE base station may be connected to the 5GC 20. In addition, the LTE base station and the gNB may be connected via an inter-base station interface.

[0015] The 5GC 20 includes an Access and Mobility Management Function (AMF) 301 (301-1, 301-2) and a User Plane Function (UPF) 302 (302-1, 302-2). The AMF 301 performs various mobility controls for the UE 100. The AMF 301 manages information on the area in which the UE 100 is located by communicating with the UE 100 using Non-Access Stratum (NAS) signaling. The UPF 302 performs data forwarding control. The AMF 301 and the UPF 302 are connected to the gNB 200 via an NG interface, which is an interface between a base station and a core network. The AMF 301 and the UPF 302 are examples of core network devices connected to the 5GC (core network) 20.

[0016] FIG. 2 is a diagram illustrating an example of a configuration of a UE 100 (user equipment) according to an embodiment.

[0017] As shown in FIG. 2, the UE 100 includes a receiving unit 110, a transmitting unit 120, and a control unit .

[0018] The receiving unit 110 performs various receptions under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts (down-converts) a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 130.

[0019] The transmission unit 120 performs various transmissions under the control of the control unit 130. The transmission unit 120 includes an antenna and a transmitter. The transmitter converts (up-converts) a baseband signal (transmission signal) output by the control unit 130 into a radio signal and transmits it from the antenna.

[0020] The control unit 130 performs various controls in the UE 100. The control unit 130 includes at least one processor and at least one memory electrically connected to the processor. The memory stores programs executed by the processor and information used in the processing by the processor. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation / demodulation and encoding / decoding of a baseband signal. The CPU executes programs stored in the memory to perform various processing. The control unit 130 may perform various processing executed by the UE 100 in each of the following embodiments.

[0021] FIG. 3 is a diagram illustrating an example configuration of a gNB 200 (base station) according to one embodiment.

[0022] As shown in FIG. 3, the gNB 200 has a transmitter 210, a receiver 220, a control unit 230, and a backhaul communication unit 240.

[0023] The transmission unit 210 performs various transmissions under the control of the control unit 230. The transmission unit 210 includes an antenna and a transmitter. The transmitter converts (up-converts) a baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna.

[0024] The receiving unit 220 performs various receptions under the control of the control unit 230. The receiving unit 220 includes an antenna and a receiver. The receiver converts (down-converts) a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 230.

[0025] The control unit 230 performs various controls in the gNB 200. The control unit 230 includes at least one processor and at least one memory electrically connected to the processor. The memory stores programs executed by the processor and information used in the processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals. The CPU executes programs stored in the memory to perform various processing. The control unit 230 may perform various processing executed by the gNB 200 in each of the embodiments described below.

[0026] The backhaul communication unit 240 is connected to adjacent base stations via an inter-base station interface. The backhaul communication unit 240 is connected to the AMF 301 and / or the UPF 302 via a base station-core network interface. Note that the gNB is composed of a CU (Central Unit) and a DU (Distributed Unit), and both units may be connected by an F1 interface.

[0027] FIG. 4 is a diagram illustrating an example of the configuration of a protocol stack of a radio interface of a user plane according to an embodiment.

[0028] As shown in FIG. 4, the radio interface protocol of the user plane that handles data has a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer.

[0029] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the PHY layer of the UE 100 and the PHY layer of the gNB 200 via a physical channel.

[0030] The MAC layer performs data priority control, retransmission processing using hybrid ARQ (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of the UE 100 and the MAC layer of the gNB 200 via a transport channel. The MAC layer of the gNB 200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be assigned to the UE 100.

[0031] The RLC layer transmits data to the RLC layer on the receiving side by using the functions of the MAC layer and the PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the gNB 200 via a logical channel.

[0032] The PDCP layer performs header compression / decompression and encryption / decryption. Data and control information are transmitted between the PDCP layer of the UE 100 and the PDCP layer of the gNB 200 via a radio bearer.

[0033] The SDAP layer maps between the QoS flow, which is the unit for QoS control by the core network, and the radio bearer, which is the unit for QoS control by the AS (Access Stratum). Note that if the RAN is connected to the EPC, the SDAP is not necessary.

[0034] FIG. 5 is a diagram illustrating an example of the configuration of a protocol stack of a radio interface of a control plane according to an embodiment.

[0035] As shown in FIG. 5, the protocol stack of the radio interface of the control plane that handles signaling (control signals) has an RRC (Radio Resource Control) layer and a NAS layer instead of the SDAP layer shown in FIG.

[0036] Between the RRC layer of the UE 100 and the RRC layer of the gNB 200, RRC signaling for various settings is transmitted. The RRC layer controls logical channels, transport channels, and physical channels in response to establishment, re-establishment, and release of radio bearers. When there is a connection (RRC connection) between the RRC of the UE 100 and the RRC of the gNB 200, the UE 100 is in an RRC connected state. When there is no connection (RRC connection) between the RRC of the UE 100 and the RRC of the gNB 200, the UE 100 is in an RRC idle state. Also, when the RRC connection is interrupted (suspended), the UE 100 is in an RRC inactive state.

[0037] The NAS layer, which is located above the RRC layer, performs session management, mobility management, etc. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the AMF 301.

[0038] In addition, the UE 100 has an application layer and the like in addition to the protocol of the radio interface.

[0039] [First embodiment] Next, a first embodiment will be described. 3GPP is considering a scenario in which the same user accesses the same service using two UEs 100. For example, a user may access the same chat service using a smartphone and a smartwatch, or may access the same server using two UEs 100 in a factory facility.

[0040] Specifically, when a user uses two UEs 100, the following cases are possible.

[0041] First, there is a case where data is transmitted and received between one UE 100 and the gNB 200, and data is not transmitted and received between the other UE 100 and the gNB 200. This is the idea that if data can be transmitted and received by one UE 100, it does not matter if data is not transmitted and received by the other UE 100.

[0042] Secondly, there is a case where the same data is transmitted and received between the base station and two UEs 100. However, there are cases where it is sufficient for one UE 100 to transmit and receive data, and cases where both UEs 100 must transmit and receive data.

[0043] When multiple UEs 100 and gNBs 200 communicate with each other, various cases such as those described above are possible. However, there is a problem as to how to realize the various cases described above.

[0044] Therefore, in the first embodiment, the gNB 200 sets a synchronized PDCP entity for each of the two UEs 100-1 and 100-2. Then, the synchronized PDCP entity of the UE 100-1 and the synchronized PDCP entity of the UE 100-2 communicate with each other, thereby enabling the UE 100-1 and the UE 100-2 to communicate with the gNB 200 in cooperation with each other.

[0045] Specifically, first, the base station (e.g., gNB 200) configures the establishment of a first synchronized PDCP entity (e.g., synchronized PDCP entity 150-1) for a first user equipment (e.g., UE 100-1) and also configures the establishment of a second synchronized PDCP entity (e.g., synchronized PDCP entity 150-2) for a second user equipment (e.g., UE 100-2). Second, the first user equipment establishes the first synchronized PDCP entity in accordance with the configuration, and the second user equipment establishes the second synchronized PDCP entity in accordance with the configuration. Third, the first synchronized PDCP entity communicates with the second synchronized PDCP entity, and the first user equipment and the second user equipment communicate with the base station in cooperation with each other.

[0046] Fig. 6 is a diagram illustrating an example of synchronous PDCP entities 150-1 and 150-2 according to the first embodiment. In the example of Fig. 6, a synchronous PDCP entity (Sync-PDCP) 150-1 is established in UE #1 (100-1), and a synchronous PDCP entity 150-2 is established in UE #2 (100-2).

[0047] The two synchronous PDCP entities 150-1 and 150-2 may be connected by a PC5 connection (SL (Sidelink)) as shown in Fig. 6. The two synchronous PDCP entities 150-1 and 150-2 may communicate with each other using sidelink communication. The two synchronous PDCP entities 150-1 and 150-2 may be connected by another wireless interface or by wire.

[0048] The synchronous PDCP entity 150-1 transmits, for example, the SN (Sequence Number) of the received data (PDCP PDU) to the synchronous PDCP entity 150-2. Even if the UE 100-2 does not receive the data (PDCP PDU), the UE 100-2 regards the data as having been received and performs the subsequent processing. As a result, even if the UE 100-2 does not actually receive the data, the UE 100-1 and the UE 100-2 can regard the data as having been received by both of them and perform processing, thereby enabling appropriate communication between the multiple UEs 100-1 and 100-2 and the gNB 200.

[0049] What information is exchanged between synchronous PDCP entities 150-1 and 150-2 will be described later in the second operation example onwards. First, in the first operation example, the setting of the synchronous PDCP entities will be described.

[0050] (First operation example of the first embodiment) Next, a first operation example of the first embodiment will be described.

[0051] 7 is a diagram illustrating a first operation example according to the first embodiment. Note that, UE#1 will be referred to as UE 100-1, and UE#2 will be referred to as UE 100-2, respectively, below.

[0052] As shown in FIG. 7, in step S10, the UE 100-1 and the UE 100-2 start processing.

[0053] In step S11, the UE 100-1 and the UE 100-2 may be in a state of having been discovered by each other. For example, the UE 100-1 may discover the UE 100-2 by using direct discovery of Prose (Proximity based services). Also, for example, the UE 100-2 may discover the UE 100-1 by using direct discovery of Prose. The UE 100-1 and the UE 100-2 may discover each other, thereby entering a state of having been discovered by each other. Alternatively, the UE 100-1 and the UE 100-2 may be paired in advance. The UE 100 may notify the gNB 200 or the AMF 301 of the direct discovery information and / or the pairing information.

[0054] In step S12, the gNB 200 performs configuration for establishing a synchronous PDCP entity for the UE 100-1 and the UE 100-2. For example, the gNB 200 performs the configuration by transmitting an RRC message including configuration information for establishing a synchronous PDCP entity to the UE 100-1 and the UE 100-2. The configuration information for establishing a synchronous PDCP entity may be included in "PDCP-Config" included in the RRC message. The configuration information for establishing a synchronous PDCP entity may include at least one of a synchronous type, a synchronization destination UE ID, a QoS (Quality of Service) flow ID to be synchronized, a DRB ID to be synchronized, and a synchronization application ID. The synchronous type, the synchronization destination UE ID, the QoS (Quality of Service) flow ID to be synchronized, and the synchronization application ID may each be linked to a DRB.

[0055] The UE 100-1 establishes a synchronized PDCP entity 150-1 upon receiving the setting from the gNB 200. Also, the UE 100-2 establishes a synchronized PDCP entity 150-2 upon receiving the setting from the gNB 200. Fig. 6 is a diagram illustrating an example of the synchronized PDCP entities 150-1 and 150-2 after the establishment.

[0056] Returning to Figure 7, gNB200 completes the series of processes.

[0057] In this way, synchronous PDCP entities 150-1 and 150-2 are established by the first operation example of the first embodiment. In the following, an operation example after synchronous PDCP entities 150-1 and 150-2 are established will be described. As an operation example after synchronous PDCP entities 150-1 and 150-2 are established, first, a case where UEs 100-1 and 100-2 receive data will be described. Next, a case where UEs 100-1 and 100-2 transmit data will be described.

[0058] (1) When receiving

[0059] (Second operation example of the first embodiment) Next, a second operation example of the first embodiment will be described. In the second operation example of the first embodiment, an example will be described in which, in a case where UE 100-1 receives data and UE 100-2 does not receive data, synchronous PDCP entity 150-1 transmits PDCP SN to synchronous PDCP entity 150-2.

[0060] Specifically, first, a first user equipment (e.g., UE 100-1) receives data from a base station, and second, a first synchronous PDCP entity (e.g., synchronous PDCP entity 150-1) transmits a sequence number of a packet included in the data to a second synchronous PDCP entity (e.g., synchronous PDCP entity 150-2).

[0061] As a result, as described above, even if the UE 100-2 is not actually able to receive the data, the UE 100-2 can regard the data as having been received by considering the data as having been received, and can perform subsequent processing. Therefore, appropriate communication between the multiple UEs 100-1 and 100-2 and the gNB 200 is possible.

[0062] FIG. 8 is a diagram illustrating a second operation example according to the first embodiment.

[0063] As shown in FIG. 8, in step S20, the UE 100-1 and the UE 100-2 start processing.

[0064] In step S21, UE 100-1 establishes synchronous PDCP entity 150-1, and UE 100-2 establishes synchronous PDCP entity 150-2. For example, similar to step S12 (FIG. 11) in the first operation example, synchronous PDCP entities 150-1 and 150-2 are established by setting by gNB 200.

[0065] In step S22, the UE 100-1 receives data from the gNB 200. The synchronization PDCP entity 150-1 of the UE 100-1 normally decodes the received data (PDCP PDU), and outputs the decoded data (PDCP SDU) to a higher layer (such as an SDAP layer).

[0066] In step S23, UE 100-1 transmits the PDCP SN to UE 100-2. UE 100-1 and UE 100-2 may be connected via a PC5 interface. In this case, synchronous PDCP entity 150-1 of UE 100-1 may transmit the PDCP SN to synchronous PDCP entity 150-2 of UE 100-2 by using a PC5-RRC message or a PC5-S message of the PC5 interface. Also, UE 100-1 and UE 100-2 may be connected by wire. UE 100-1 may transmit the PDCP SN to UE 100-2 via an application.

[0067] In step S24, the UE 100-2 receives from the UE 100-1 the PDCP SN transmitted from the UE 100-1. The synchronous PDCP entity 150-2 receives the PDCP SN.

[0068] First, the UE 100-2 regards the UE 100-2 as having received the PDCP SN even if the UE 100-2 has not actually received data from the gNB 200. Alternatively, the UE 100-2 may regard the UE 100-2 as having received the PDCP up to the sequence number in question in response to the reception of the PDCP SN. The synchronous PDCP entity 150-1 may move the reception window (RX_DELIV) to the sequence number in question. The reception window (RX_DELIV) represents a count value of waiting PDCP SDUs that have not been transmitted to a higher layer.

[0069] Secondly, UE 100-2 may notify the lower layer (RLC / MAC / PHY) that the data has been received. The synchronous PDCP entity 150-2 may notify the lower layer of this. The synchronous PDCP entity 150-2 may instruct the lower layer to discard the currently received packet. The synchronous PDCP entity 150-2 may also instruct the lower layer to immediately hand over the currently received packet to the upper layer. When the RLC entity of UE 100-2 is performing a retransmission process, it may cancel the transmission of the NACK by receiving this notification from the synchronous PDCP entity 150-2.

[0070] In step S25, in response to receiving the PDCP SN from the UE 100-1, the UE 100-2 transmits a PDCP Status Report to the gNB 200. For example, the synchronous PDCP entity 150-2 transmits the PDCP Status Report to the gNB 200. The PDCP Status Report indicates that data (PDCP PDU) up to the sequence number has been normally received. Note that the UE 100-2 may transmit another report (or message) instead of the PDCP Status Report.

[0071] In step S26, in response to receiving the PDCP Status Report from UE 100-2, gNB 200 stops transmitting data (PDCP) having the sequence number to UE 100-2. Upon receiving the PDCP Status Report, gNB 200 determines that data has been successfully received at UE 100-2, and stops transmitting data (PDCP) having the sequence number. If gNB 200 is performing a retransmission process to UE 100-2, gNB 200 stops retransmission of data having the sequence number to UE 100-2.

[0072] In step S27, the gNB200 ends the example process.

[0073] (Third operation example of the first embodiment) Next, a third operation example of the first embodiment will be described. The third operation example of the first embodiment is an example in which, when the UE 100-1 receives data from the gNB 200, the synchronization PDCP entity 150-1 transmits the received data (PDCP SDU) to the synchronization PDCP entity 150-2.

[0074] Specifically, a first user equipment (e.g., UE 100-1) receives data from a base station (e.g., gNB 200). Secondly, a first synchronous PDCP entity (e.g., synchronous PDCP entity 150-1) transfers a packet (e.g., PDCP SDU) included in the data to a second synchronous PDCP entity (e.g., synchronous PDCP entity 150-2).

[0075] As a result, even if, for example, UE 100-1 receives data transmitted from gNB 200 but UE 100-2 fails to receive the data, UE 100-2 can properly receive the data because the data is transferred from UE 100-1. Also, even if both UE 100-1 and UE 100-2 receive data transmitted from gNB 200, UE 100-2 can properly receive the data because the data is transferred from UE 100-1, and it is possible to improve the reception accuracy in UE 100-2.

[0076] Fig. 9 is a diagram showing a third operation example according to the first embodiment. Fig. 9 is also applicable to a case where both UE 100-1 and UE 100-2 receive data. Fig. 9 is also applicable to a case where UE 100-1 receives the data and UE 100-2 does not receive the data.

[0077] As shown in FIG. 9, in step S30, the UE 100-1 and the UE 100-2 start processing.

[0078] In step S31, the UE 100-1 establishes the synchronized PDCP entity 150-1, and the UE 100-2 establishes the synchronized PDCP entity 150-2. For example, the synchronized PDCP entity 150-1 and the UE 100-2 may be established by configuration by the gNB 200, similar to step S12 (FIG. 11) in the first operation example.

[0079] In step S32, UE 100-1 receives data from gNB 200. Synchronous PDCP entity 150-1 of UE 100-1 normally decodes a packet (PDCP PDU) included in the received data by, for example, decrypting the encrypted PDCP SDU. Synchronous PDCP entity 150-1 outputs the decoded packet (PDCP SDU) to an upper layer of UE 100-1.

[0080] In step S33, the UE 100-1 transfers the packet (PDCP SDU) included in the data to the UE 100-2. For example, the synchronous PDCP entity 150-1 transfers the PDCP SDU to the synchronous PDCP entity 150-2. The synchronous PDCP entity 150-1 may transmit the SN of the PDCP SDU to the synchronous PDCP entity 150-2.

[0081] In step S34, UE 100-2 receives the data (PDCP SDU) transmitted from UE 100-1. UE 100-2 considers that it has received the data even if it has not actually received the data from gNB 200. When UE 100-2 receives PDCP SN from UE 100-1, UE 100-2 may consider that it has received up to the data (PDCP PDU) of the sequence number indicated by the PDCP SN.

[0082] In addition, when the synchronization PDCP entity 150-2 of the UE 100-2 receives data transmitted from the gNB 200 and successfully decodes the data, the synchronization PDCP entity 150-2 may transfer the received data (PDCP SDU) to the synchronization PDCP entity 150-1 of the UE 100-1.

[0083] Then, in step S35, the UE 100-1 and the UE 100-2 end the series of processes.

[0084] (2) In case of transmission

[0085] (Fourth operation example of the first embodiment) Next, a fourth operation example of the first embodiment will be described. The fourth operation example of the first embodiment and a fifth operation example of the first embodiment described later are examples in which data is transmitted from the UE 100-1 and the UE 100-2.

[0086] The fourth operation example of the first embodiment is an example in which, when the UE 100-1 normally transmits data to the gNB 200, the UE 100-1 transmits the sequence number of the packet included in the data to the UE 100-2.

[0087] Specifically, first, a first user device (e.g., UE 100-1) transmits data to a base station (e.g., gNB 200). Second, a first synchronized PDCP entity (e.g., synchronized PDCP entity 150-1) transmits a sequence number of a packet included in the data to a second synchronized PDCP entity (e.g., synchronized PDCP entity 150-2).

[0088] As a result, for example, when UE 100-1 and UE 100-2 are transmitting the same data to gNB 200, UE 100-1 transmits the sequence number to UE 100-2, and UE 100-2 considers that transmission of the data is completed and can stop data transmission. Therefore, UE 100-1 and UE 100-2 can appropriately transmit data to gNB 200. Also, UE 100-1 and UE 100-2 can reduce redundancy by stopping transmission of the same data.

[0089] FIG. 10 is a diagram illustrating a fourth operation example according to the first embodiment.

[0090] The fourth operation example is also applicable to a case in which the UE 100-1 transmits data and the UE 100-2 does not transmit data. The fourth operation example is also applicable to a case in which both the UE 100-1 and the UE 100-2 transmit data.

[0091] In the fourth operation example, it is assumed that synchronous PDCP entities 150-1 and 150-2 are both connected to the same application layer, and UE 100-1 and UE 100-2 transmit the same data.

[0092] As shown in FIG. 10, in step S40, the UE 100-1 and the UE 100-2 start the process.

[0093] In step S41, UE 100-1 establishes synchronous PDCP entity 150-1, and UE 100-2 establishes synchronous PDCP entity 150-2.

[0094] In step S42, UE 100-1 and UE 100-2 receive the same packet from the application layer. For example, synchronous PDCP entity 150-1 of UE 100-1 and synchronous PDCP entity 150-2 of UE 100-2 receive the same packet from the application layer.

[0095] Here, UE 100-1 and UE 100-2 attempt to transmit data including the packet. Then, a case is assumed in which UE 100-2 retransmits the packet and the transmission of the data is delayed. Alternatively, a case may be assumed in which UE 100-1 transmits the data and UE 100-2 does not transmit the data. The gNB 200 may set, for UE 100-1 and UE 100-2, which of UE 100-1 and UE 100-2 UE 100 will attempt to transmit first. The setting may be performed using an RRC message, a PDCP Control PDU, a MAC CE (Control Element), or DCI (Downlink Control Information), etc.

[0096] In step S43, the UE 100-1 completes the transmission of the data. For example, the synchronous PDCP entity 150-1 may confirm the completion of the transmission of the data including the packet by receiving confirmation of ACK reception from a lower layer (RLC or MAC) in retransmission control in the lower layer.

[0097] In step S44, UE 100-1 transmits the PDCP SN of the packet to UE 100-2. For example, synchronized PDCP entity 150-1 transmits the PDCP SN to synchronized PDCP entity 150-2 of UE 100-2. As in the second operation example (step S23 in FIG. 8), synchronized PDCP entity 150-1 may transmit the PDCP SN by using a PC5-RRC message or a PC5-S message, etc.

[0098] In step S45, UE 100-2 considers that the transmission of the packet is completed. UE 100-2 may consider that the transmission of the packet (PDCP PDU) up to the PDCP SN is completed. For example, synchronous PDCP entity 150-2 of UE 100-2 is configured to consider that the transmission of the packet is completed in response to receiving PDCP SN, even if the transmission of the packet is not completed or the transmission of the packet is not being performed. Note that the upper layer of UE 100-2 (RRC entity or synchronous PDCP entity 150-2) may notify the lower layer of the completion of the transmission of the packet. In this case, synchronous PDCP entity 150-2 may discard the packet received from the application layer. In addition, in this case, the lower layer of UE 100-2 (RLC entity or MAC entity) may discard the packet upon receiving the transmission completion.

[0099] In step S46, when UE 100-1 has not completed transmission of the packet (or when transmission of the packet is delayed due to retransmission processing), UE 100-1 may transmit the PDCP SN of the packet that has not been completed to UE 100-2. In this case, UE 100-2 may attempt to transmit the packet that has not been completed in UE 100-1 to gNB 200 in response to receiving the PDCP SN. Thereby, for example, in a case where UE 100-1 has performed transmission and UE 100-2 has not performed transmission, if UE 100-1 has not completed transmission, it becomes possible to transmit data that has not been completed by using UE 100-2.

[0100] Then, in step S47, UE 100-1 and UE 100-2 end the series of processes.

[0101] (Fifth operation example of the first embodiment) Next, a fifth operation example of the first embodiment will be described. The fifth operation example of the first embodiment is an example in which UE 100-1 and UE 100-2 transmit the same data to the gNB 200. Specifically, first, a first synchronized PDCP entity (e.g., synchronized PDCP entity 150-1) transmits data to a second synchronized PDCP entity (e.g., synchronized PDCP entity 150-2). Second, a first user equipment (e.g., UE 100-1) and a second user equipment (e.g., UE 100-2) transmit data to a base station (e.g., gNB 200).

[0102] This allows, for example, the UE 100-1 and the UE 100-2 to appropriately transmit the same data to the gNB 200. Also, it is possible to improve the reliability of data transmission from the UEs 100-1 and 100-2.

[0103] FIG. 11 is a diagram showing a fifth operation example according to the first embodiment. In the fifth operation example according to the first embodiment, a case in which UE 100-1 and UE 100-2 perform transmission is applicable. In addition, in the fifth operation example, a case in which UE 100-1 performs transmission and UE 100-2 does not perform transmission is also applicable. However, in the fifth operation example, it is assumed that UE 100-1 and UE 100-2 receive data (packets) from different application layers.

[0104] As shown in FIG. 11, in step S50, the UE 100-1 and the UE 100-2 start the process.

[0105] In step S51, UE 100-1 establishes synchronous PDCP entity 150-1, and UE 100-2 establishes synchronous PDCP entity 150-2.

[0106] In step S52, the UE 100-1 receives a packet from the application layer.

[0107] In step S53, the UE 100-1 transfers the packet (PDCP SDU) to the UE 100-2. For example, the synchronous PDCP entity 150-1 copies the packet received from the application layer and transmits the copied packet to the synchronous PDCP entity 150-2 of the UE 100-2. The synchronous PDCP entity 150-1 may transmit the packet through sidelink communication.

[0108] In step S54, the UE 100-1 and the UE 100-2 attempt to transmit the packet. The same data (packet) is transmitted from the UE 100-1 and the UE 100-2.

[0109] Then, in step S55, the UE 100-1 and the UE 100-2 end the series of processes.

[0110] [Second embodiment] Next, a second embodiment will be described.

[0111] In the first embodiment, an example has been described in which data is received at two UEs 100-1 and 100-2 and data is transmitted from two UEs 100-1 and 100-2 by using synchronous PDCP entities 150-1 and 150-2.

[0112] The second embodiment is an example in which an inter-UE split bearer is set in two UEs 100-1 and 100-2. The UEs 100-1 and 100-2 transmit and receive data to and from the gNB 200 by using the inter-UE split bearer.

[0113] Specifically, first, a base station (e.g., gNB200) sets a split bearer between a first user equipment (e.g., UE100-1) and a second user equipment (e.g., UE100-2) for the first user equipment and the second user equipment. Second, the first user equipment communicates with the base station using a first route (e.g., first radio bearer) between the first user equipment and the base station according to the setting, and also communicates with the base station using a second route (e.g., second radio bearer) between the second user equipment and the base station.

[0114] As described above, in the second embodiment, the UE 100-1, 100-2 transmits and receives data to and from the gNB 200 by using the first route and the second route set by the inter-UE split bearer, and therefore, appropriate communication can be performed between the UE 100-1, 100-2 and the gNB 200. In addition, efficient communication can also be performed.

[0115] FIG. 12 is a diagram illustrating an example of an inter-UE split bearer according to the first embodiment. As illustrated in FIG. 12, the PDCP entity 155 of the UE 100-1 is associated with the RLC entity 151-1 of the UE 100-1 and is associated with the RLC entity 151-2 of the UE 100-2. In this case, the UE 100-1 may be a master UE, and the UE 100-2 may be a secondary UE. The inter-UE split bearer includes a first radio bearer between the UE 100-1 including the RLC entity 151-1 and the gNB 200, and a second radio bearer between the UE 100-2 including the RLC entity 151-2 and the gNB 200. The UE 100-1 can communicate with the gNB 200 by using the first radio bearer. The UE 100-1 can also communicate with the gNB 200 by using the second radio bearer via the UE 100-2.

[0116] Here, the UE 100-1 and the UE 100-2 may be connected by PC5 (SL (Sidelink)) as in the first embodiment. The UE 100-1 and the UE 100-2 may communicate with each other by using sidelink communication as in the first embodiment. The UE 100-1 and the UE 100-2 may be connected by another wireless interface or may be connected by a wired connection as in the first embodiment.

[0117] Note that UE 100-2 may be connected to an application layer. In this case, when UE 100-2 receives a packet from the application layer, it transmits the packet to an SDAP entity or PDCP entity 155 of UE 100-1. The SDAP entity maps the QoS flow and the radio bearer for the packet, and the PDCP entity 155 performs processing such as encryption for the packet (PDCP SDU).

[0118] Then, PDCP entity 155 can transmit the processed packet to RLC entity 151-2 of UE 100-2 by using the inter-UE split bearer. This allows, for example, data on the UE 100-2 side to be subjected to processing such as encryption on the UE 100-1 side, and the processed data to be transmitted from UE 100-2.

[0119] In the following, first, an operation example (first operation example) regarding the setting of an inter-UE split bearer will be described. Next, an operation example (second operation example) of UL transmission after the inter-UE split bearer is set will be described. Finally, an operation example (third operation example) of DL transmission after the inter-UE split bearer is set will be described.

[0120] (First operation example of the second embodiment) Next, a description will be given of a first operation example of the second embodiment. The first operation example of the second embodiment represents a setting example in which an inter-UE split bearer is set for the UE 100-1 and the UE 100-2.

[0121] FIG. 13 is a diagram illustrating a first operation example according to the second embodiment.

[0122] As shown in FIG. 13, in step S60, the UE 100-1 and the UE 100-2 start the process.

[0123] In step S61, the UE 100-1 and the UE 100-2 may be in a state where they have been discovered by each other. As in the first embodiment (step S11 in FIG. 7), the UE 100-1 and the UE 100-2 may be in a discovery state by discovering each other by using a discovery function.

[0124] In step S62, the gNB 200 sets up an inter-UE split bearer for the UE 100-1 and the UE 100-2. The gNB 200 may perform the setting by transmitting a message including setting information of the inter-UE split bearer to the UE 100-1 and the UE 100-2.

[0125] First, the setting information of the UE-to-UE split bearer may be, for example, as follows: Fig. 14 and Fig. 15 are diagrams showing examples of setting information of the UE-to-UE split bearer according to the second embodiment. Among them, Fig. 14 shows an example of the setting information that the gNB 200 sets for the UE 100-1.

[0126] FIG. 14 shows an example in which "RLC-BearerConfig" is used as the setting information. The dotted line (X) ("Serving LogicalChannel") in FIG. 14 represents the RLC channel (RLC bearer and MAC LCH) of the UE 100-1. The dotted line (Y) in FIG. 14 represents information related to the radio bearer of sidelink communication associated with this RLC channel. Furthermore, the line ("ServedRadioBearer") below the dotted line (Y) in FIG. 14 includes information related to the DRB (PDCP entity 155) associated with this RLC channel.

[0127] In other words, the configuration information set in UE 100-1 links the DRB (PDCP entity 155), the DRB for sidelink communication, and the RLC channel of UE 100-1, and this linking indicates that an inter-UE split bearer is configured.

[0128] On the other hand, FIG. 15 shows an example of the setting information that the gNB 200 sets for the UE 100-2. FIG. 15 also shows an example in which "RLC-BearerConfig" is used as the setting information. FIG. 15 includes "LogicalChannelIdentity" and "serverRadioBearer". "LogicalChannelIdentity" represents the RLC channel (RLC bearer and MAC LCH) of the UE 100-2. "serverRadioBearer" represents information on the bearer associated with the RLC channel. The information on the bearer associated with the RLC channel includes "drb-identity" and the radio bearer ("sl-drb") for sidelink communication (dotted line (X)). "drb-identity" represents the ID of the DRB (PDCP entity 155) of the UE 100-1.

[0129] In other words, the configuration information set in UE 100-2 links the RLC channel of UE 100-2, the DRB (PDCP entity 155) of UE 100-1, and the DRB for sidelink communication between UE 100-1 and UE 100-2, and this linking indicates that an inter-UE split bearer is configured.

[0130] Secondly, the setting information of the inter-UE split bearer may include the following. That is, the setting information of the inter-UE split bearer may include information indicating which UE is the master and which UE is the secondary. For example, the setting information shown in FIG. 14 may include information indicating that UE 100-1 is the master UE, and the setting information shown in FIG. 15 may include information indicating that UE 100-2 is the secondary UE.

[0131] The configuration information for setting up the inter-UE split bearer may include information indicating which UE (or which link) is to be the primary in UL transmission, and may further include information indicating which UE (or which link) is to be the secondary.

[0132] Furthermore, the configuration information for configuring the inter-UE split bearer may include information indicating whether or not duplication (or simultaneous transmission) is to be performed.

[0133] Returning to FIG. 13, in step S63, the gNB 200 may configure to activate or deactivate the inter-UE split bearer. The configuration may be performed using an RRC message, a MAC CE, or a DCI. The configuration may be the activation or deactivation of the SL DRB. In this case, the inter-UE split bearer may be activated (or turned on) by activating the SL DRB. Also, the inter-UE split bearer may be deactivated (or turned off) by deactivating the SL DRB. Note that, when a Radio Link Failure (SL-RLF) occurs in the PC5 connection between the UE 100-1 and the UE 100-2, or when the PC-5 RRC connection is released, the inter-UE split bearer may be (automatically) de-activated. Or, in such a case, the configuration of the inter-UE split bearer may be (automatically) de-configured.

[0134] In step S64, when the inter-UE split bearer is in an activated state, the UEs 100-1 and 100-2 and the gNB 200 perform a predetermined process. The predetermined process is UL transmission or DL ​​transmission. The UL transmission will be described in a second operation example of the second embodiment, and the DL transmission will be described in a third operation example of the second embodiment.

[0135] In step S65, UE 100-1, 100-2 and gNB 200 end the series of processes.

[0136] (Second operation example of the second embodiment) Next, a description will be given of a second operation example of the second embodiment. The second operation example of the second embodiment is an example in which UL transmission is performed in a state in which an inter-UE split bearer is active.

[0137] Specifically, a PDCP entity of a first user equipment (e.g., the PDCP entity 155 of the UE 100-1) transmits data to a base station (e.g., the gNB 200) using a first path (e.g., a first radio bearer). Also, the PDCP entity of the first user equipment transmits data to the base station using a second path (e.g., a second radio bearer).

[0138] In this way, UE 100-1 can transmit data to gNB 200 using the first radio bearer and the second radio bearer, thereby enabling proper UL transmission.

[0139] FIG. 16 is a diagram illustrating a second operation example according to the second embodiment.

[0140] As shown in FIG. 16, in step S70, the UE 100-1 starts UL transmission.

[0141] In step S71, the SDAP entity of the UE 100-1 receives a packet (SDAP SDU) from the application layer. The SDAP entity of the UE 100-1 may receive a packet (SDAP SDU) from the UE 100-2.

[0142] In step S72, the PDCP entity 155 of the UE 100-1 receives the packet (PDCP SDU) from the SDAP entity. The PDCP entity 155 may perform processing such as security, header compression, and header attachment on the packet.

[0143] In step S73, PDCP entity 155 of UE 100-1 outputs the packet to either RLC entity 151-1 of UE 100-1 or RLC entity 151-2 of UE 100-2 in accordance with the setting of the inter-UE split bearer (step S62 in FIG. 13).

[0144] First, when duplication is set, PDCP entity 155 outputs the packet to both RLC entities 151-1 and 151-2.

[0145] Secondly, if single transmission is set, the PDCP entity 155 outputs the packet to either the RLC entity 151-1 or the RLC entity 151-2 in accordance with the setting of the inter-UE split bearer.

[0146] In addition, the PDCP entity 155 transmits the packet to the RLC entity 151-2 of the UE 100-2 by mapping the packet to the SL DRB in accordance with the setting. The RLC entity 151-2 receives the packet via the SL DRB.

[0147] In step S74, UE 100-1 and / or UE 100-2 transmit data including the packet to gNB 200. UE 100-1 transmits data to gNB 200 using the first radio bearer. Also, UE 100-1 transmits data to gNB 200 via UE 100-2 using the second radio bearer.

[0148] In step S75, the gNB 200 receives the data. The PDCP entity of the gNB 200 may perform processing such as discarding duplicate packets and performing sequence control.

[0149] Then, in step S76, the gNB200 ends the series of processes.

[0150] (Third operation example of the second embodiment) Next, a description will be given of a third operation example of the second embodiment. The third operation example of the second embodiment is an example in which DL transmission is performed in a state in which an inter-UE split bearer is active.

[0151] Specifically, a PDCP entity of a first user equipment (e.g., PDCP entity 155 of UE 100-1) receives data transmitted from a base station (e.g., gNB 200) using a first route (e.g., a first radio bearer) and receives data transmitted from the base station using a second route (e.g., a second radio bearer).

[0152] As a result, the UE 100-1 can receive data transmitted from the gNB 200 via the first radio bearer and the second radio bearer, thereby enabling proper DL transmission.

[0153] FIG. 17 is a diagram illustrating a third operation example according to the second embodiment.

[0154] As shown in FIG. 17, in step S80, gNB200 starts DL transmission.

[0155] In step S81, the gNB 200 transmits data to the UE 100-1 and / or the UE 100-2. The gNB 200 may duplicate the data (PDCP PDU), transmit the original data to the UE 100-1, and transmit the duplicated data to the UE 100-2.

[0156] In step S82, the UE 100-1 receives the data transmitted from the gNB 200. The RLC entity 151-1 of the UE 100-1 outputs, to the PDCP entity 155, a packet (PDCP PDU) included in the data.

[0157] In step S83, the UE 100-2 receives the data transmitted from the gNB 200. The RLC entity 151-2 of the UE 100-2 maps a packet (PDCP PDU) included in the data to an SL DRB in accordance with the setting of the inter-UE split bearer. The PDCP entity 155 of the UE 100-1 receives the packet via the SL DRB.

[0158] In step S84, PDCP entity 155 of UE 100-1 discards duplicate packets. PDCP entity 155 may discard either the packet received from RLC entity 151-1 or the packet received from RLC entity 151-2. PDCP entity 155 may perform sequence control. PDCP entity 155 may also perform processes performed by a PDCP entity, such as security, header compression, and header attachment.

[0159] In step S85, PDCP entity 155 of UE 100-1 outputs the processed packet (PDCP SDU) to an upper layer.

[0160] Then, in step S86, the UE 100-1 ends the series of processes.

[0161] [Other embodiments] A program may be provided that causes a computer to execute each process performed by the UE 100 or the gNB 200. The program may be recorded in a computer-readable medium. Using the computer-readable medium, it is possible to install the program in the computer. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.

[0162] In addition, circuits that execute each process performed by UE100 or gNB200 may be integrated, and at least a part of UE100 or gNB200 may be configured as a semiconductor integrated circuit (chip set, SoC).

[0163] As used in this disclosure, the terms "based on" and "depending on" do not mean "based only on" or "depending only on," unless otherwise specified. The term "based on" means both "based only on" and "based at least in part on." Similarly, the term "depending on" means both "based only on" and "based at least in part on." Additionally, "obtain / acquire" may mean obtaining information from stored information, from information received from other nodes, or by generating information. The terms "include," "comprise," and variations thereof do not mean including only the items listed, but may include only the items listed, or may include additional items in addition to the items listed. Additionally, the term "or" as used in this disclosure is not intended to be an exclusive or. Additionally, any reference to elements using designations such as "first," "second," etc., as used in this disclosure is not intended to generally limit the quantity or order of those elements. These designations may be used herein as a convenient method of distinguishing between two or more elements. Thus, reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some manner. In this disclosure, where articles are added by translation, such as a, an, and the in English, these articles are intended to include the plural unless the context clearly indicates otherwise.

[0164] Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes and the like are possible without departing from the scope of the invention. In addition, it is also possible to combine all or part of each embodiment as long as there is no contradiction.

[0165] This application claims priority to Japanese Patent Application No. 2021-119141 (filed July 19, 2021), the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0166] 1: Mobile communication systems 10:5GC 100(100-1,100-2):UE 110: Receiving unit 120: Transmitter 150-1, 150-2: Synchronous PDCP entity 151-1: RLC entity 151-2: RLC entity 155 :PDCP Entity 200(200-1~200-3): gNB 210: Transmission unit 220: Receiving unit 230: Control section 301: AMF 302: UPF

Claims

1. A network device sets up, for a first user device, a route between the network device and the first user device via a second user device; The configuring includes the network device sending an RRC message to the first user equipment; The RRC message includes information on a route addition for adding a route on a sidelink between the first user equipment and the second user equipment, information on an RLC channel, and information on a radio bearer. Communications control method.

2. A network device, a control unit that sets, for a first user device, a path between the network device and the first user device via a second user device; A transmitter for transmitting an RRC message to the first user equipment, The RRC message includes information on a route addition for adding a route on a sidelink between the first user equipment and the second user equipment, information on an RLC channel, and information on a radio bearer. Network device.

3. A first user device and a second user device; A cellular communication system having a network device, the network device sets, for the first user device, a route between the network device and the first user device via the second user device; setting up the route includes the network device sending an RRC message to the first user equipment; The RRC message includes information on a route addition for adding a route on a sidelink between the first user equipment and the second user equipment, information on an RLC channel, and information on a radio bearer. Cellular communication systems.

4. On the network device computer, causing a first user device to execute a process of setting a route between the network device and the first user device via a second user device; The process of configuring includes a process of the network device transmitting an RRC message to the first user equipment; The RRC message includes information on a route addition for adding a route on a sidelink between the first user equipment and the second user equipment, information on an RLC channel, and information on a radio bearer. program.

5. A chipset for a network device, comprising: for a first user device, setting up a route between the network device and the first user device via a second user device; The configuring includes transmitting an RRC message to the first user equipment; The RRC message includes information on a route addition for adding a route on a sidelink between the first user equipment and the second user equipment, information on an RLC channel, and information on a radio bearer. Chipset.

Images