A communication method and apparatus

Abstract

The application provides a communication method and device, and relates to the technical field of communication. In the method, a first terminal receives a first message used for configuring a transmission channel, a first identifier and first information of a second terminal in the first message, so that the first terminal can uniquely determine the second terminal, or in other words, the first terminal can distinguish the second terminal and a third terminal using the same local identifier through different second identifiers, thereby avoiding the problem of local identifier conflict caused by the same local identifier of the second terminal and the third terminal in a communication link. In this way, even if there are relay terminals with the same local identifier in the communication link, it can be ensured that each hop of data can be successfully forwarded.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0002] In single-hop relay communication scenarios, a relay user equipment (UE) can serve a maximum of 256 remote UEs, and each remote UE can be uniquely identified within the relay network. Different relay users may serve remote UEs with the same local identifier. For situations where remote UEs on different links within the same base station may have the same local identifier, the base station can ensure that the local identifiers of the remote UEs do not conflict. For example, relay user A serves a remote UE with local identifier #1, and relay user B also serves a remote UE with local identifier #1. When network devices (such as base stations) receive data from remote UEs with the same local identifier, they can distinguish them by the different Uu interfaces (the Uu interfaces between the network devices and the relay users).

[0003] In multi-hop relay communication scenarios, multiple relay terminals exist in the sidelink (SL). If two or more terminals (including relay terminals and remote terminals) use the same local identifier in the SL link, a local identifier conflict will occur, leading to data forwarding failure. Therefore, resolving local identifier conflicts among terminals in the SL link is an urgent problem to be solved in multi-hop relay communication scenarios. Summary of the Invention

[0004] This application provides a communication method and apparatus.

[0005] Firstly, a communication method is provided. This method can be executed by a first terminal, for example, by the first terminal itself, or by a module applied to the first terminal (e.g., a processor, chip, or chip system), or by a logical node, logical module, or software capable of implementing all or part of the functions of the first terminal. For ease of description, the following description assumes that the method is executed by the first terminal. The method includes: receiving a first message and sending a second message in response to the first message. The first message is used to configure a transmission channel; the first message includes a first identifier and first information, which are used to identify a second terminal. The first information includes a second identifier, which is an identifier of the transmission channel or a radio bearer identifier. The first identifier is used to locally identify the second terminal, and the first terminal provides relay services to the second terminal. The second identifier of the second terminal is different from the second identifier of a third terminal, while the first identifier is the same as the identifier used to locally identify the third terminal, and the second terminal provides relay services to the third terminal.

[0006] Based on the method described in the first aspect, the first terminal receives a first message for configuring the transmission channel. The first message contains a first identifier and first information of the second terminal, enabling the first terminal to uniquely identify the second terminal. In other words, the first terminal can distinguish between the second terminal and the third terminal using the same local identifier through different second identifiers, avoiding local identifier conflicts caused by the second and third terminals having the same local identifier in the side-link communication link. Thus, even if there are relay terminals with the same local identifier in the side-link communication link, it can be guaranteed that each hop of data can be successfully forwarded.

[0007] In one possible implementation, the transmission channel identifier is used to identify the radio link control protocol (RLC) channel of the link between the first terminal and the second terminal, or to identify the RLC channel of the link between the first terminal and the access network device. It is understood that the transmission channel identifier is different from the transmission channel identifier corresponding to the third terminal. For example, if the access network device assigns the same local identifier (i.e., the first identifier) ​​to the second terminal and the third terminal, then the access network device configures the radio bearer data of the second terminal to be transmitted using a different RLC channel than that of the third terminal. It can be understood that different RLC channels correspond to different transmission channel identifiers.

[0008] In this way, the second and third terminals are distinguished by the transmission channel identifier, and the first terminal can subsequently identify data packets carrying the same local identifier through different RLC channels. Furthermore, the upper limit of relay terminals or remote terminals served by a single relay terminal (such as the first terminal) is sufficiently high; for example, the number of available RLC channels is 512, meaning a single relay terminal can determine a maximum of 512 different RLC channels, which can meet the requirement of serving a maximum of 256 relay terminals or remote terminals simultaneously.

[0009] In one possible implementation, the radio bearer identifier of the second terminal is used to identify the radio bearer of the second terminal. It is understood that the radio bearer identifier of the second terminal is different from that of the third terminal. During subsequent data packet transmission (such as sidelink relay adaptation protocol (SRAP) packets), the radio bearer identifier can be carried in the packet header.

[0010] Thus, the first terminal receives the first identifier and the radio bearer identifier of the second terminal through the first message. The configuration allows for the determination of a unique second terminal, i.e., a unique exit RLC channel, based on the first identifier and the radio bearer identifier of the second terminal during subsequent data transmission. Furthermore, the radio bearer identifier can be carried in the packet header, which can improve the data packet transmission rate.

[0011] Optionally, the second terminal is uniquely identified by the first terminal. For example, the second terminal can be the next-hop terminal in the communication link where the first terminal is located, and the first terminal can connect to the second terminal via a PC5 interface. The local identifier of the second terminal ranges from 0 to 255. The local identifier of the second terminal can be uniquely identified by the first terminal.

[0012] The first terminal can uniquely identify the second terminal. When the first terminal receives downlink transmitted data (such as SRAP data), it can determine the unique egress RLC channel (which can be an egress RLC channel) as the channel between the second terminal and the first terminal. In this embodiment, each terminal (including relay terminals and remote terminals) in the side-hop communication link can be uniquely identified by the previous hop terminal. Correspondingly, in the communication link, the local identifier of the next-hop terminal of each hop terminal has a value range of 0-255.

[0013] In one possible implementation, the communication method may further include: receiving data and sending data to a second terminal based on the first information.

[0014] It is understandable that after the first terminal receives the data, since the data is associated with the first identifier and the first information, the first terminal determines the unique exit RLC channel for sending the data through the first identifier and the first information, which can ensure the successful transmission of data.

[0015] Optionally, data is sent to the second terminal based on the first identifier and the first information.

[0016] Optionally, if the second identifier is the radio bearer identifier of the second terminal, then the data, the first identifier, and the radio bearer identifier of the second terminal are carried in the first data unit. Alternatively, if the second identifier is the identifier of the transmission channel, then the first identifier and the data are carried in the first data unit, and the identifier of the transmission channel is carried in the data in indication information independent of the first data unit.

[0017] It is understood that the first data unit can be an SRAP protocol data unit (PDU). If the first information includes a radio bearer identifier, then the first information is carried in the first data unit; if the first information includes a transmission channel identifier, then the first information is carried in indication information independent of the first data unit. Optionally, if the first information includes both a transmission channel identifier and a radio bearer identifier, then the radio bearer identifier is carried in the first data unit, and the transmission channel identifier is carried in indication information independent of the first data unit.

[0018] Thus, during relay communication, the first terminal can uniquely identify the second terminal based on the second terminal's first identifier and first information. In other words, by using different second identifiers to distinguish between the second terminal and the third terminal using the same local identifier, the problem of local identifier conflict caused by the second and third terminals having the same local identifier in the side-link communication can be avoided. Therefore, when the first terminal receives data from the access network device or the relay terminal, it can ensure that each hop of data is successfully forwarded.

[0019] Secondly, a communication method is provided. This method can be executed by an access network device, for example, by the access network device itself, or by a module applied to the access network device (e.g., a processor, chip, or chip system), or by a logical node, logical module, or software capable of implementing all or part of the functions of the access network device. For ease of description, the following description uses the execution of the method by the access network device as an example. The method includes: sending a first message to a first terminal, the first message being used to configure a transmission channel; the first message includes a first identifier and first information, the first identifier and the first information being used to identify a second terminal. The first information includes a second identifier, the second identifier being an identifier of the transmission channel or a radio bearer identifier; the first identifier is used to locally identify the second terminal, and the first terminal provides relay services to the second terminal; the second identifier of the second terminal is different from the second identifier of a third terminal, and the first identifier is the same as the identifier used to locally identify the third terminal, and the second terminal provides relay services to the third terminal. Receiving a second message, the second message being used to respond to the first message.

[0020] In one possible implementation, the transmission channel identifier is used to identify the RLC channel of the link between the first terminal and the second terminal, or to identify the RLC channel of the link between the first terminal and the access network device.

[0021] In one possible implementation, the radio bearer identifier of the second terminal is used to identify the radio bearer of the second terminal.

[0022] Optionally, the second terminal is uniquely identified by the first terminal.

[0023] The technical effects of the method described in the second aspect above can also be found in the description of the first aspect above, and will not be repeated here.

[0024] Thirdly, a communication method is provided. This method can be executed by a first unit of an access network device, for example, by the first unit itself, or by a module (e.g., processor, chip, or chip system) applied to the first unit, or by a logical node, logical module, or software capable of implementing all or part of the functions of the first unit of the access network device. For ease of description, the following description assumes that the method is executed by the first unit of the access network device. The method includes: receiving a first message from a second unit of the access network device, the first message being used to assign a first local identifier to a first terminal, the first local identifier being the same as a second local identifier of at least one terminal, and at least one terminal providing relay services to the first terminal; and sending a second message to the second unit, the second message being used to identify the first terminal.

[0025] Based on the method in the third aspect, during the relay communication process, the first unit of the access network device sends a second message to the second unit to identify the first terminal. This allows the second unit to uniquely identify the first terminal based on the second message when the first local identifier of the first terminal is the same as the local identifier of at least one terminal. This avoids the problem of local identifier conflict caused by the existence of terminals with the same local identifier in the side-link communication link, and also avoids the failure of the first terminal's initial access process.

[0026] Optionally, the second message is a radio resource control (RRC) establishment request message for the first terminal. For example, the second message is the initial uplink RRC message transmission message during the RRC establishment request process of the first terminal.

[0027] In one possible implementation, the first message includes a transmission channel identifier of a first terminal, which identifies the RLC channel of the link between the first terminal and the second terminal, wherein the second terminal provides relay services to the first terminal. The transmission channel identifier of the first terminal is different from the transmission channel identifier of at least one terminal.

[0028] In other words, when the second unit of the access network device allocates the local identifier of the first terminal through the first message, it also sends the transmission channel identifier of the first terminal to the first unit through the first message. Thus, when the first unit receives data, it can determine the first terminal by combining the transmission channel identifier and the first local identifier of the first terminal.

[0029] Optionally, the second message includes the transmission channel identifier of the first terminal.

[0030] In this way, the second unit can uniquely identify the first terminal based on the transmission channel identifier of the first terminal. For example, after receiving the second message, the second unit can store the transmission channel identifier of the first terminal in the second message, and determine the first terminal based on the transmission channel identifier and the first local identifier. Then, the second unit can send an RRC establishment message to the first terminal through the first unit, thus avoiding access failure during the initial access process of the first terminal. Alternatively, the second unit can determine that the data comes from the first terminal based on the transmission channel identifier of the received data, thus uniquely identifying the first terminal and ensuring successful data forwarding.

[0031] In one possible implementation, the first message further includes first indication information, which indicates the correspondence between the first local identifier and the Layer 2 identifier of the first terminal. That is, when the second unit of the access network device allocates the local identifier of the first terminal through the first message, it also sends the first indication information to the first unit through the first message, so that when the first unit receives the SRAP data PDU, it can identify the first terminal through the correspondence between the first local identifier and the Layer 2 identifier of the first terminal.

[0032] Optionally, the second message includes the first indication information. Thus, the second unit can identify the first terminal based on the correspondence between the first local identifier and the layer 2 identifier of the first terminal, avoiding access failure during the initial access process of the first terminal.

[0033] In one possible implementation, the first message also includes path information, which indicates the previous-hop terminal and the next-hop terminal of each terminal in the relay communication link between the first terminal and the access network device. That is, when the second unit of the access network device allocates the local identifier of the first terminal through the first message, it also sends the path information to the first unit through the first message, so that the first unit can identify the first terminal through the first local identifier and the path information when it receives the SRAP data PDU.

[0034] Optionally, the second message includes path information. Thus, after receiving the second message, the second unit can store the path information in the second message, and uniquely identify the first terminal based on the path information and the first local identifier. The first unit then sends an RRC establishment message to the first terminal, thus preventing access failure during the initial access process of the first terminal.

[0035] In one possible implementation, the first terminal is a remote terminal. The first message includes second indication information, which indicates the local identifier of the second terminal. The second terminal provides relay services to the first terminal, and its local identifier is different from the first local identifier. That is, when the second unit of the access network device allocates the local identifier of the first terminal through the first message, it also sends the second indication information to the first unit through the first message. Thus, when the first unit receives data, it can determine that the first-hop relay terminal corresponding to the data is the second terminal by comparing the first local identifier with the local identifier of the second terminal.

[0036] Optionally, the second message includes second indication information. Thus, after receiving the second message, the second unit can store the local identifier of the second terminal in the second message, and determine the first-hop relay terminal as the second terminal based on the local identifier of the second terminal. The first unit then sends an RRC establishment message to the second terminal, and subsequently, the second terminal sends an RRC establishment message to the first terminal, thus avoiding access failure during the initial access process of the first terminal.

[0037] Fourthly, a communication method is provided. This method can be executed by a second unit of an access network device, for example, by the second unit itself, or by a module (e.g., processor, chip, or chip system) applied to the second unit of the access network device, or by a logical node, logical module, or software capable of implementing all or part of the functions of the second unit of the access network device. For ease of description, the following description uses the execution of this method by the second unit of the access network device as an example. The method includes: sending a first message to a first unit of the access network device, the first message being used to assign a first local identifier to a first terminal, the first local identifier being the same as a second local identifier of at least one terminal, and at least one terminal providing relay services to the first terminal; and receiving a second message from the second unit, the second message being used to identify the first terminal.

[0038] Optionally, the second message is an RRC establishment request message for the first terminal.

[0039] In one possible implementation, the first message includes a transmission channel identifier of a first terminal, which identifies a Radio Link Control (RLC) channel for the link between the first terminal and the second terminal, wherein the second terminal provides relay services to the first terminal; the transmission channel identifier of the first terminal is different from the transmission channel identifier of at least one terminal.

[0040] Optionally, the second message includes the transmission channel identifier of the first terminal.

[0041] In one possible implementation, the first message further includes first indication information, which is used to indicate the correspondence between the first local identifier and the layer 2 identifier of the first terminal.

[0042] Optionally, the second message includes the first instruction information.

[0043] In one possible implementation, the first message also includes path information, which is used to indicate the previous hop terminal and the next hop terminal of each terminal in the relay communication link between the first terminal and the access network device.

[0044] Optionally, the second message includes path information.

[0045] In one possible implementation, the first terminal is a remote terminal; the first message includes second indication information, which is used to indicate the local identifier of the second terminal, the second terminal provides relay services to the first terminal, and the local identifier of the second terminal is different from the first local identifier.

[0046] Optionally, the second message includes a second instruction message.

[0047] The technical effects of the method in the fourth aspect mentioned above can also be found in the relevant introduction in the third aspect mentioned above, and will not be repeated here.

[0048] Fifthly, a communication method is provided. This method can be executed by a first terminal or a chip within the first terminal. For example, it can be executed by the first terminal itself, or by a module applied to the first terminal (e.g., a processor, chip, or chip system), or by a logical node, logical module, or software capable of implementing all or part of the functions of the first terminal. For ease of description, the following description assumes the method is executed by the first terminal. The method includes: receiving data, a first identifier, and first information, wherein the first identifier and the first information are used to identify a second terminal. The first identifier is used to locally identify the second terminal, and the first identifier is the same as the identifier used to locally identify a third terminal. The first information is used to determine the second terminal. Data is then transmitted to the second terminal.

[0049] Based on the method described in the first aspect, the first terminal can uniquely identify the second terminal based on the first information. In other words, the first terminal can distinguish between the second terminal and the third terminal using the same local identifier through the first information, thus avoiding the problem of local identifier conflict caused by the second terminal and the third terminal having the same local identifier in the side-link communication link. In this way, even if there are relay terminals with the same local identifier in the side-link communication link, it can be guaranteed that each hop of data can be forwarded successfully.

[0050] In one possible implementation, the first information includes an identifier of a transmission channel, which is used to identify the Radio Link Control (RLC) channel of the link between the first terminal and the second terminal. The identifier of the transmission channel is different from the transmission channel identifier corresponding to the third terminal, which is used to identify the RLC channel of the link between the first terminal and the third terminal.

[0051] Optionally, data is transmitted to the first terminal via the RLC channel of the link between the first terminal and the second terminal.

[0052] In one possible implementation, the first information includes a radio bearer identifier, and the radio bearer identifier of the second terminal is different from that of the third terminal.

[0053] In one possible implementation, the first information includes the Layer 2 identifier of the second terminal.

[0054] In one possible implementation, the first information includes hop count information, which indicates that the first terminal is the Nth hop terminal in the relay communication link between the first terminal and the access network device, where N is an integer greater than or equal to 1.

[0055] In one possible implementation, the first information includes path information, which is used to indicate the previous hop terminal and the next hop terminal of each terminal in the relay communication link between the first terminal and the access network device.

[0056] In one possible implementation, if the first information includes a radio bearer identifier, then the data, the first identifier, and the radio bearer identifier are carried in the first data unit; or,

[0057] If the first information includes an identifier of the transmission channel, then the first identifier and the data are carried in the first data unit, and the identifier of the transmission channel is carried in indication information separate from the first data unit.

[0058] The technical effects of the method in the fifth aspect mentioned above can also be found in the descriptions of any of the first to fourth aspects mentioned above, and will not be repeated here.

[0059] A sixth aspect provides a communication device. The communication device includes a processor configured to perform the method according to any one of the embodiments of the first to fifth aspects.

[0060] In one possible implementation, the communication device of the sixth aspect may further include a transceiver. This transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used by the communication device of the sixth aspect to communicate with other communication devices.

[0061] In one possible implementation, the communication device of the sixth aspect may further include a memory. This memory may be integrated with the processor or disposed separately. The memory may be used to store computer programs and / or data relating to the methods of any of the embodiments of the first to fifth aspects.

[0062] In the embodiments of this application, the communication device of the sixth aspect can be a terminal device or access network device of any one of the first to fifth aspects, or a chip (system) or other component or assembly disposed in the terminal device or access network device, or a device containing the terminal device or access network device.

[0063] Furthermore, the technical effects of the communication device in the sixth aspect can be referred to the technical effects of any of the embodiments in the first to fifth aspects, and will not be repeated here.

[0064] A seventh aspect provides a communication device. The communication device includes a processor coupled to a memory, the processor being configured to execute a computer program or instructions stored in the memory, causing the communication device to perform the method of any one of the embodiments of the first to fifth aspects.

[0065] In one possible implementation, the communication device may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the seventh aspect and other communication devices.

[0066] In one possible implementation, the communication device further includes the memory for storing the aforementioned computer program or instructions. Optionally, the memory and processor are integrated together.

[0067] In the embodiments of this application, the communication device described in the seventh aspect may be a terminal device or access network device described in any one of the first to fifth aspects, or may be a chip (system) or other component or assembly disposed in the terminal device or access network device, or may include the terminal device or access network device.

[0068] Furthermore, the technical effects of the communication device described in the seventh aspect can be referred to the technical effects of any of the embodiments in the first to fifth aspects, and will not be repeated here.

[0069] Eighthly, a communication system is provided. The communication system includes: a first terminal for performing the method according to any embodiment of the first and fifth aspects; an access network device for performing the method according to any embodiment of the second aspect; and an access network device for performing the method according to any embodiment of the third and fourth aspects.

[0070] A ninth aspect provides a computer-readable storage medium comprising: a computer program or instructions; wherein, when the computer program or instructions are executed, the method as described in any of the embodiments of the first to fifth aspects is implemented.

[0071] In a tenth aspect, a computer program product is provided, comprising a computer program or instructions that, when executed, cause the method as described in any of the embodiments of the first to fifth aspects above to be implemented.

[0072] Eleventh aspect: A chip is provided, including a processor connected to a memory for storing a computer program, the processor for executing the computer program stored in the memory, such that the method of any of the embodiments of the first to fifth aspects described above is implemented. Attached Figure Description

[0073] Figure 1 This is a schematic diagram illustrating communication between a remote UE and a relay UE.

[0074] Figure 2 This is a schematic diagram of multi-hop relay communication;

[0075] Figure 3 This is a schematic diagram of the SRAP data format;

[0076] Figure 4 A diagram illustrating the allocation of local IDs for remote UEs;

[0077] Figure 5 A diagram illustrating local ID allocation in a multi-hop relay communication scenario. Figure 1 ;

[0078] Figure 6 A diagram illustrating local ID allocation in a multi-hop relay communication scenario. Figure 2 ;

[0079] Figure 7 This is a schematic diagram of the initial access process for a remote UE in a U2N relay communication scenario.

[0080] Figure 8 A schematic diagram of the architecture of a communication system to which the method provided in the embodiments of this application is applicable. Figure 1 ;

[0081] Figure 9 A schematic diagram of the architecture of a communication system to which the method provided in the embodiments of this application is applicable. Figure 2 ;

[0082] Figure 10 A schematic diagram illustrating the application scenarios to which the methods provided in the embodiments of this application are applicable;

[0083] Figure 11Flowchart of the communication method provided in the embodiments of this application Figure 1 ;

[0084] Figure 12 This is a communication diagram for a multi-hop relay communication scenario;

[0085] Figure 13 Flowchart of the communication method provided in the embodiments of this application Figure 2 ;

[0086] Figure 14 Flowchart of the communication method provided in the embodiments of this application Figure 3 ;

[0087] Figure 15 Flowchart of the communication method provided in the embodiments of this application Figure 4 ;

[0088] Figure 16 Flowchart of the communication method provided in the embodiments of this application Figure 5 ;

[0089] Figure 17 This is a flowchart illustrating the communication method under the O-RAN architecture.

[0090] Figure 18 Schematic diagram of the communication device provided in the embodiments of this application Figure 1 ;

[0091] Figure 19 Schematic diagram of the communication device provided in the embodiments of this application Figure 2 . Detailed Implementation

[0092] The technical solutions of this application embodiment can be applied to various communication systems, such as Wireless Fidelity (Wi-Fi) systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, vehicle-to-everything (V2X) communication systems, fourth-generation (4G) mobile communication systems, such as Long Term Evolution (LTE) systems, Worldwide Interoperability for Microwave Access (WiMAX) communication systems, fifth-generation (5G) mobile communication systems, such as New Radio (NR) systems, and future communication systems.

[0093] For ease of understanding, the technical terms involved in the embodiments of this application will be introduced below.

[0094] 1. Relay UE:

[0095] A relay UE typically refers to a special type of user equipment (UE) in the field of wireless communication. It can not only receive and transmit data as a regular UE, but also act as a relay device to forward wireless signals, thereby enhancing the coverage and quality of the wireless signal. This communication link through a relay UE can also be called an indirect path. It should be understood that a relay UE can also be called a relay device, relay node, etc., without restriction.

[0096] Relay UEs are used in both LTE and NR networks, especially in areas with poor signal coverage, such as remote areas and inside buildings. In certain V2X application scenarios, such as densely populated urban areas or long-distance communication, relay UEs can be used to enhance communication signals between vehicles and between vehicles and infrastructure. Especially in situations with insufficient signal coverage or obstructions, relay UEs can receive weak signals, amplify them, and retransmit them, thereby ensuring the stability and reliability of communication.

[0097] Relay UEs can be divided into two types: UE-to-network (U2N) relay UEs and UE-to-UE (U2U) relay UEs. U2N relay UEs can receive signals from the base station (gNB) and forward them to other UEs, which are called U2N remote UEs. This replaces a poor-quality link with two better-quality links, thereby obtaining higher link capacity and better coverage, and improving the communication quality of U2N remote UEs.

[0098] This application involves a U2N scenario. For ease of description, U2N relay UE will be abbreviated as relay UE, and U2N remote UE will be abbreviated as remote UE. This will be used uniformly here.

[0099] For example, Figure 1 This is a schematic diagram illustrating communication between a remote UE and a relay UE. (Example:) Figure 1 As shown, the relay UE and gNB are connected via the Uu interface, and the relay UE and the remote UE are connected via the near-field communication 5 (PC5) interface. Figure 1 In the past, the relay UE was a single-hop relay UE, meaning that the communication link between the gNB and the remote UE only went through one relay UE. Currently, 3GPP has introduced multi-hop relay. In multi-hop relay scenarios, there is more than one relay UE in the communication link.

[0100] For example, Figure 2 This is a schematic diagram of multi-hop relay communication. (Example) Figure 2 As shown, the relay UE and gNB are connected via the Uu interface, and the relay UE(s) are connected to each other and to the remote UE via the PC5 interface.

[0101] In this application, the first relay UE, the second relay UE, etc., can be collectively referred to as the intermediate relay UE. The intermediate relay UE can be a single hop (containing one relay UE) or multiple hops (containing the first relay UE, the second relay UE, and more possible relay UEs), and there is no limitation in this regard.

[0102] 2. Local identity (local ID) of the relay UE:

[0103] In relay communication scenarios, local IDs are typically used as identification information to identify remote UEs during data transmission. A remote UE's local ID is uniquely identifiable within the relay UE network. In cases where remote UEs on different links within the same site may have the same local ID, the base station can ensure that local ID conflicts do not occur.

[0104] For example, Figure 3 This is a schematic diagram of the data format for the Sidelink Relay Adaptation Protocol (SRAP). Figure 3 As shown, the local ID is stored in the UE ID field of the SRAP data packet and is represented by 8 bits. The data field in the SRAP data packet is used to store data. SRAP data packets carrying the local ID can be transmitted on the Uu interface or PC5 interface via bearers, such as radio bearers (RBs), using the same or different radio link control protocol (RLC) channels. If transmitted on the Uu interface, the relay RLC channel is also called a Uu relay RLC channel (or Uu relay RLC channel); if transmitted on the PC5 interface, the relay RLC channel is also called a PC5 relay RLC channel (or PC5 relay RLC channel). Different relay RLC channels use different identification information, such as the relay RLC channel ID. Different bearers use different bearer IDs, such as the RB ID.

[0105] Specifically, for the Uu relay RLC channel: the configuration of the side-link egress RLC Uu channel (which can be sl-EgressRLC-ChannelUu) is related to the side-link local identifier (which can be sl-LocalIdentity) and the RB ID of the side-link remote UE (which can be sl-RemoteUE-RB-Identity). For the PC5 relay RLC channel: the configuration of the side-link egress RLC PC5 channel (which can be sl-EgressRLC-ChannelPC5) is related to the side-link local identifier (which can be sl-LocalIdentity) and the RB ID of the side-link remote UE (which can be sl-RemoteUE-RB-Identity).

[0106] In relay communication scenarios, the local ID is used to identify the UE in the local context, thereby simplifying the management and communication of the local network. The local ID is only valid within the relay node or the local network and is not globally unique.

[0107] Currently, in single-hop relay communication scenarios, a single relay UE can serve a maximum of 256 remote UEs, meaning a single relay UE can connect to a maximum of 256 remote UEs via PC5. It should be understood that a relay UE serving remote UEs can be termed the relay UE providing relay services to the remote UEs.

[0108] For example, Figure 4 A diagram illustrating the allocation of local IDs for remote UEs. (See diagram below.) Figure 4 As shown, different relay UEs (i.e., relay UE a and relay UE b) may have remote UEs with the same local ID. For example, relay UE a is connected to remote UE1 to remote UE256 via the PC5 interface, and relay UE b is connected to remote UE1 to remote UE256 via the PC5 interface. The base station can distinguish SRAP data from relay UE a and relay UE b through different Uu interfaces.

[0109] However, the relay UE in a single-hop relay communication scenario corresponds to the last-hop relay UE in a multi-hop relay communication scenario. In a multi-hop relay communication scenario, to ensure that the local IDs of the relay UEs do not conflict, the base station needs to ensure that the local ID of the last-hop relay UE can uniquely identify the remote UE. That is, each last-hop relay UE can serve a maximum of 256 remote UEs. Furthermore, two or more UEs cannot use the same local ID in the SL link, otherwise a local ID conflict will occur. In the embodiments of this application, the last-hop relay UE can be a device connected to the access network equipment via a Uu interface.

[0110] For example, Figure 5 A diagram illustrating local ID allocation in a multi-hop relay communication scenario. Figure 1 .like Figure 5 As shown in (a), under the same gNB, the gNB can distinguish SRAP data from last-hop relay UE a and last-hop relay UE b through different Uu interfaces. The intermediate relay UEs (including the first-hop relay UE) and remote UEs served by last-hop relay UE a share 256 local IDs, and these 256 local IDs cannot be duplicated. Similarly, the intermediate relay UEs and remote UEs served by last-hop relay UE b share 256 local IDs, and these 256 local IDs cannot be duplicated. For example, as... Figure 5 As shown in (b), the gNB is connected to the last-hop relay UE via the Uu interface. The last-hop relay UE is connected to intermediate relay UE a and intermediate relay UE b via PC5. The local ID of intermediate relay UE a is 1, and the local ID of intermediate relay UE b is 4. Intermediate relay UE a is connected to remote UE a and remote UE b via PC5. The local ID of remote UE a is 2, and the local ID of remote UE b is 3. Intermediate relay UE b is connected to remote UE c via PC5. The local ID of remote UE c is 5. In other words, the local IDs of intermediate relay UEs and remote UEs in the SL link where a last-hop relay UE is located cannot be duplicated.

[0111] Thus, in multi-hop relay communication scenarios, the intermediate relay UEs (including the first-hop relay UE) and remote UEs served by the last-hop relay UE share 256 local IDs. As the number of hops increases, the number of remote UEs that the last-hop relay UE can support is constrained compared to single-hop relay communication scenarios. The maximum number of remote UEs that the last-hop relay UE can serve will be much less than 256, resulting in limited service range. If the number of remote UEs connected by the last-hop relay UE is to be increased, for example, still reaching 256, local ID conflicts will occur.

[0112] For example, Figure 6 A diagram illustrating local ID allocation in a multi-hop relay communication scenario. Figure 2 .like Figure 6As shown, the gNB is connected to the last-hop relay UE via the Uu interface. The last-hop relay UE is connected to intermediate relay UE a via PC5, and intermediate relay UE a's local ID is 1. Intermediate relay UE a is connected to remote UE a, remote UE b, and intermediate relay UE b via PC5, with remote UE a's local ID being 1, remote UE b's local ID being 2, and intermediate relay UE b's local ID being 3. Intermediate relay UE b is connected to remote UE c via PC5, and remote UE c's local ID is 3. At this point, intermediate relay UE a and remote UE a have the same local ID, and intermediate relay UE b and remote UE c have the same local ID. This means that two UEs in the SL link are using the same local ID, causing a local ID conflict. Similarly, each hop UE may experience a local ID conflict, leading to data packet transmission problems and severely impacting service operation.

[0113] 3. Initial access process for remote UEs in relay communication scenarios:

[0114] With the development of communication technology, in order to improve network efficiency, flexibility and performance, gNB has been further divided into two logical functional entities: the central unit (CU) and the distributed unit (DU).

[0115] gNB-CU: Primarily responsible for handling higher-level protocol functions that are less time-sensitive. It performs control plane and non-real-time user plane functions.

[0116] gNB-DU: Primarily responsible for handling time-sensitive low-level protocol functions, including RLC, media access control (MAC), and physical layer protocol (PHY). The gNB-DU connects directly to the radio interface and manages all real-time operations of the air interface, such as scheduling and access.

[0117] Figure 7 This is a schematic diagram illustrating the initial access process of a remote UE in a U2N relay communication scenario. Figure 7 As shown, this process includes S700-S710, which involves single-hop relay UE communication. The gNB is split into CU-DU, and the specific process is as follows:

[0118] In S700, the remote UE and the relay UE perform a discovery process and establish a PC5 connection.

[0119] S701, the remote UE sends an RRC establishment request (which may be an RRCSetupRequest) message to the relay UE.

[0120] Specifically, the remote UE sends an RRC establishment request message to the relay UE through the PC5 relay RLC channel.

[0121] S702, the relay UE sends a sidelink UE information NR (which may be a SidelinkUEInformationNR) message to the gNB-DU.

[0122] The relay UE temporarily stores the RRC establishment request message received from the remote UE and sends a side-link UE information NR message to the gNB-DU. Before this, if the relay UE is in RRC idle state (which can be RRC_IDLE) / RRC inactive state (which can be RRC_INACTIVE), then when the relay UE receives the RRC establishment request message, it should trigger the RRC establishment / recovery process to enter the RRC connected state (which can be RRC_CONNECTED).

[0123] S703, gNB-DU and gNB-CU exchange information to complete the local ID allocation for the remote UE.

[0124] The gNB-CU assigns a local ID to the remote UE based on its data link layer / layer 2 (L2) ID. Furthermore, the gNB-DU and gNB-CU exchange information to configure the Uu trunk RLC channel. The L2 ID is an identifier for the data link layer in the Open System Interconnection (OSI) model. The L2 ID is used to uniquely identify a device or node at the data link layer. L2 IDs are typically used in local area networks (LANs) or virtual local area networks (VLANs). In trunk communication scenarios, the local ID focuses more on local device management, while the L2 ID focuses more on data link layer communication and management. Both play important roles in the network and are usually used together to achieve efficient data transmission and resource management.

[0125] S704, gNB-DU sends an RRC reconfiguration (which may be RRCReconfiguration) message to the relay UE.

[0126] The RRC reconfiguration message is used to configure the remote UE's local ID, Uu Relay RLC channel, and the bearer mapping for the signalalling radio bearer (SRB0). In other words, the RRC reconfiguration message can include the remote UE's local ID, Uu Relay RLC channel configuration, and the bearer mapping for the remote UE's SRB0. SRB0 is the bearer used to transmit RRC establishment request messages / RRC connection establishment messages.

[0127] S705, the relay UE sends an RRC reconfiguration complete (or RRCReconfigurationComplete) message to the gNB-DU.

[0128] S706, gNB-DU sends an uplink RRC message transmission (which can be a UL RRC MESSAGE TRANSFER message) to gNB-CU.

[0129] Specifically, gNB-DU encapsulates the RRC reconfiguration completion message and sends the uplink RRC message transmission message of the relay UE to gNB-CU.

[0130] S707, the relay UE sends an RRC establishment request message to the gNB-DU.

[0131] This RRC establishment request message is an RRC establishment request message for the remote UE.

[0132] After receiving the remote UE's local ID, Uu relay RLC channel configuration, and SRB0 bearer mapping for the remote UE via the RRC reconfiguration message, the relay UE sends the remote UE's RRC establishment request message to the gNB-DU. The remote UE's local ID and the SRB's RB ID are transmitted in the header of the SRAP data packet.

[0133] S708, gNB-DU sends an initial uplink RRC message transmission (which may be INITIAL UL RRCMESSAGE TRANSFER) message to gNB-CU.

[0134] The gNB-DU assigns a cell radio network temporary identifier (C-RNTI) to the remote UE and a UE-related logical F1 interface identifier (which can be gNB-DU UE F1APID) to the relay UE within the gNB-DU. It then sends an initial uplink RRC message transmission message to the gNB-CU by encapsulating the remote UE's RRC establishment request message. This initial uplink RRC message transmission message also includes the remote UE's local ID and the relay UE's gNB-DU UE F1AP ID.

[0135] The allocation of a gNB-DU UE F1AP ID is for the purpose of uniquely identifying the UE within the gNB-DU via the F1 interface. When the gNB-CU receives the gNB-DU UE F1AP ID, it should store the ID for the duration of the UE's UE-related logical F1 interface connection. The gNB-DU UE F1AP ID should be unique within the gNB-DU logical node.

[0136] S709, gNB-CU sends a downlink RRC message transmission (which can be a DL RRC MESSAGE TRANSFER message) to gNB-DU.

[0137] Specifically, the gNB-CU assigns a UE-related logical F1 interface identifier (which can be the gNB-CU UEF1AP ID) to the remote UE and generates an RRC establishment message pointing to the remote UE. The RRC establishment message is encapsulated in a downlink RRC message transmission (which can be a DL RRC MESSAGE TRANSFER) message and contains at least the PC5 trunk RLC channel configuration and bearer mapping for transmitting the remote UE's SRB1.

[0138] The allocation of a gNB-CU UE F1AP ID is for the purpose of uniquely identifying the UE within the gNB-CU via the F1 interface. When the gNB-DU receives the gNB-CU UE F1AP ID, it should store the ID for the duration of the UE's UE-related logical F1 interface connection. The gNB-CU UE F1AP ID should be unique within the gNB-CU logical node.

[0139] S710, gNB-DU sends an RRC establishment message to a remote UE through the relay UE.

[0140] The remote UE begins the RRC connection establishment process.

[0141] During the initial access process of a remote UE, if the local ID assigned to the remote UE by the gNB is the same as that of a previously accessed UE (such as a relay UE), then the local ID of the remote UE will conflict in the initial uplink RRC message transmission message sent by the gNB-DU to the gNB-CU. Since the gNB-DU UE F1AP ID of the relay UE can only be uniquely identified within the node, the gNB-CU cannot uniquely identify the remote UE. As a result, the remote UE cannot accurately receive the RRC establishment message, causing the remote UE to fail to access.

[0142] To address the aforementioned technical problems, this application proposes the following technical solutions, which will be described below with reference to the accompanying drawings.

[0143] In the embodiments of this application, "instruction" can include direct and indirect instructions, as well as explicit and implicit instructions. The information indicated by a certain piece of information is called the information to be instructed. In the specific implementation process, there are many ways to instruct the information to be instructed, such as, but not limited to, directly instructing the information to be instructed, such as the information to be instructed itself or its index. It can also indirectly instruct the information to be instructed by instructing other information, where there is a correlation between the other information and the information to be instructed. It can also instruct only a part of the information to be instructed, while the other parts are known or pre-agreed upon. For example, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing instruction overhead to some extent. At the same time, common parts of various pieces of information can be identified and uniformly indicated to reduce the instruction overhead caused by individually indicating the same information.

[0144] Furthermore, the specific instruction method can also be any existing instruction method, such as, but not limited to, the above-mentioned instruction methods and their various combinations. As described above, for example, when multiple pieces of information of the same type need to be indicated, the instruction methods for different pieces of information may differ. In the specific implementation process, the required instruction method can be selected according to specific needs. This application embodiment does not limit the selected instruction method. Therefore, the instruction methods involved in this application embodiment should be understood to cover various methods that enable the party to be instructed to obtain the information to be indicated.

[0145] The information to be instructed can be sent as a whole or divided into multiple sub-information messages, and the sending period and / or timing of these sub-information messages can be the same or different. The specific sending method is not limited in this application embodiment. The sending period and / or timing of these sub-information messages can be predefined, for example, according to a protocol, or configured by the sending node device by sending configuration information to the receiving node device.

[0146] In this application, "sending information" can be understood as one device sending information to another device, or it can also be understood as one logical module within a device sending information to another logical module. For example, "network device sending information" can be understood as a network device sending information to another device (such as a terminal device or other network devices), or it can be understood as logical module 1 in the network device sending information to logical module 2 in the network device.

[0147] In this application, "receiving information" can be understood as one device receiving information from another device, or it can also be understood as a logical module within a device receiving information from another logical module. For example, "network device receiving information" can be understood as a network device receiving information from another device (such as a terminal device or other network devices), or it can be understood as logical module 1 in the network device receiving information from logical module 2 in the network device.

[0148] In this application, the phrase "sending information to... (e.g., a terminal device)" or the related illustrations in the accompanying drawings can be understood as the destination of the information being the terminal device. This can include sending information directly or indirectly to the terminal device. Similarly, "receiving information from... (e.g., a terminal device)," "receiving information from... (e.g., a terminal device)," or "receiving information sent (e.g., by a terminal device)," or the related illustrations in the accompanying drawings, can be understood as the source of the information being the terminal device. This can include receiving information directly or indirectly from the terminal device. Information may undergo necessary processing between the source and destination, such as format changes, but the destination can understand the valid information from the source. Similar expressions in this application can be interpreted similarly, and will not be elaborated further here.

[0149] "Predefined" or "pre-configured" can be achieved by pre-saving corresponding codes, tables, or other means that can be used to indicate relevant information in the device. This application does not limit the specific implementation method. "Saving" can refer to saving in one or more memories. These memories can be separate installations or integrated into the encoder, decoder, processor, or communication device. Alternatively, some memories can be separately installed, while others are integrated into the decoder, processor, or communication device. The type of memory can be any form of storage medium, and this application does not limit this.

[0150] The “protocol” mentioned in the embodiments of this application may refer to a protocol family in the field of communication, a standard protocol with a similar protocol family frame structure, or a related protocol applied to future communication systems. The embodiments of this application do not specifically limit this.

[0151] In the embodiments of this application, descriptions such as "when," "under the circumstances," "if," and "if" all refer to the device making corresponding processing under certain objective circumstances, and are not limited to a specific time. They do not require the device to make a judgment action during implementation, nor do they imply any other limitations.

[0152] In the description of the embodiments of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can represent A or B. "And / or" in the embodiments of this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, in the description of the embodiments of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. Additionally, to facilitate a clear description of the technical solutions of the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or order of execution, and that "first," "second," etc., are not necessarily different. Furthermore, in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or implementation described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or implementations. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner for ease of understanding.

[0153] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0154] To facilitate understanding of the embodiments of this application, let's first take... Figure 8 The communication system illustrated herein is used as an example to illustrate a communication system applicable to embodiments of this application. For example, Figure 8 A schematic diagram of the architecture of a communication system to which the method provided in the embodiments of this application is applicable. Figure 1 .

[0155] like Figure 8 As shown, the communication system mainly includes a first terminal and access network equipment. The first terminal can be a relay device, such as the last-hop relay UE, intermediate relay UE (including the first-hop relay UE), etc., as mentioned above. The first terminal can also be a remote UE, and there are no restrictions on this.

[0156] The access network equipment may also include a first unit and a second unit. The first unit may be a DU, as described above in gNB-DU, and the second unit may be a CU, as described above in gNB-CU.

[0157] Understandable. Figure 8 This is a simplified diagram for ease of understanding. The communication system may also include other devices, such as terminal devices other than the first terminal. Figure 8 It was not drawn.

[0158] In one possible scenario, this communication system could be applied to 5G or future communication systems, for example, Figure 9 A schematic diagram of the architecture of a communication system to which the method provided in the embodiments of this application is applicable. Figure 2 .like Figure 9 As shown, the communication system 10 includes a RAN 100, a core network (CN) 200, and an Internet 300. The RAN 100 includes at least one RAN node (e.g., Figure 9 110a and 110b (collectively referred to as 110) and at least one terminal device (such as Figure 9 RAN 100, denoted as RAN 120a-120j, is collectively referred to as RAN 120. RAN 100 may also include other RAN nodes, such as wireless relay equipment and / or wireless backhaul equipment. Figure 9 (Not shown in the image). Terminal device 120 is connected to RAN node 110 wirelessly. RAN node 110 is connected to core network 200 wirelessly or via wired connection. The core network equipment in core network 200 and RAN node 110 in RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and radio access network logical functions.

[0159] RAN 100 can be a 3GPP-related cellular system, such as a 4G or 5G mobile communication system, or a future-oriented evolution system (such as a future mobile communication system). RAN 100 can also be an open access network (open RAN, O-RAN, or ORAN), a cloud radio access network (CRAN), or a Wi-Fi system. RAN 100 can also be a communication system that integrates two or more of the above systems.

[0160] RAN node 110, sometimes also referred to as access network equipment, RAN entity, or access node, constitutes part of the communication system and assists terminal equipment in achieving wireless access. Multiple RAN nodes 110 in communication system 10 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal equipment 120 are relative, for example... Figure 9 Network element 120i can be a helicopter or a drone, and it can be configured as a mobile base station. For terminal devices 120j that access RAN 100 through network element 120i, network element 120i is a base station; however, for base station 110a, network element 120i is a terminal device. RAN node 110 and terminal device 120 are sometimes referred to as communication devices, for example... Figure 9 Network elements 110a and 110b can be understood as communication devices with base station functions, while network elements 120a-120j can be understood as communication devices with terminal equipment functions.

[0161] In one possible scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a future mobile communication system, a base station in a future mobile communication system, or an access point (AP) in a Wi-Fi system, etc. A RAN node can also be a macro base station (such as...) Figure 9 110a), micro base stations or indoor stations (such as Figure 9 The RAN node can be a relay node or donor node (as described in section 110b), or a wireless controller in a CRAN scenario. Optionally, the RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of the RAN node in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The RAN node in this application can also be a logical node, logical module, or software capable of implementing all or part of the RAN node functions.

[0162] In another possible scenario, multiple RAN nodes collaborate to assist terminal devices in achieving wireless access, with different RAN nodes each implementing a portion of the base station's functions. For example, RAN nodes can be CUs, DUs, CUs (control plane, CP), CUs (user plane, UP), or radio units (RUs). CUs and DUs can be configured separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as RRUs, active antenna units (AAUs), or remote radio heads (RRHs).

[0163] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0164] It is understood that the RAN node mentioned above can be a newly defined name, and RAN nodes can also be described in different ways, such as access node, network device, wireless access node, etc., without limitation. Unless otherwise specified in this application, network device will be used as the term.

[0165] Terminal devices can also be called terminals, user equipment (UE), mobile stations, mobile terminal devices, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), V2X communication, machine-type communication (MTC), Internet of Things (IoT), point-of-sale (POS) machines, customer-premises equipment (CPE), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables (e.g., smartwatches, smart bracelets, pedometers, smart glasses), smart transportation, smart cities, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicle devices (e.g., vehicle units, in-vehicle modules, in-vehicle chips, on-board units (OBUs) or telematics boxes (T-BOXs)), drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, satellite terminal devices, etc. The embodiments of this application do not limit the device form of the terminal device.

[0166] In one possible scenario, this communication system can be applied to multi-hop relay communication scenarios, for example, Figure 10 This is a schematic diagram illustrating the application scenarios to which the methods provided in the embodiments of this application are applicable. For example... Figure 10 As shown, the remote UE connects to the gNB through multi-hop relay UEs, meaning the remote UE communicates with the gNB through intermediate relay UEs. The intermediate relay UEs can be referred to in the technical terminology section for details. For example, remote UE a and remote UE b are each connected to intermediate relay UE a via PC5. Intermediate relay UE a communicates with the gNB through the last-hop relay UE. The local ID of remote UE a is 1, the local ID of remote UE b is 2, and the local ID of intermediate relay UE a is 1. Remote UE c connects to intermediate relay UE b via PC5. Intermediate relay UE b communicates with the gNB through the last-hop relay UE. The local ID of both remote UE c and intermediate relay UE b is 2. Each relay UE (including intermediate and last-hop relay UEs) can serve a maximum of 256 next-hop UEs, and the possible values ​​of the local ID of each hop UE are 0 to 255.

[0167] In this communication system, the first terminal receives a first message for configuring the transmission channel. This first message contains a first identifier and first information for the second terminal, enabling the first terminal to uniquely identify the second terminal. In other words, the first terminal can distinguish between the second terminal and the third terminal using the same local identifier through different second identifiers, avoiding local identifier conflicts caused by identical local identifiers between the second and third terminals in the communication link. Thus, even if relay terminals with the same local identifier exist in the communication link, it can be guaranteed that data is successfully forwarded at each hop.

[0168] The following will combine Figures 11-14 This application provides a detailed description of the interaction process between various network elements / devices in the aforementioned communication system through method embodiments. The communication method provided in this application can be applied to the aforementioned communication system and specifically to various scenarios / processes mentioned in the aforementioned communication system, which will be described in detail below.

[0169] First, we will introduce the downlink transmission process in multi-hop relay communication scenarios.

[0170] In a multi-hop relay communication scenario, the communication link includes an access network device, a last-hop relay terminal, at least one intermediate relay terminal (including the first-hop relay terminal), and a remote terminal. For any one of the last-hop relay terminal, at least one intermediate relay terminal (including the first-hop relay terminal), and the remote terminal (which can be referred to as the first terminal), the access network device configures a transmission channel for that first terminal. The following discusses the process of the access network device configuring a transmission channel for different terminal types, such as Case 1, Case 2, and Case 3.

[0171] Case 1: The first terminal is the last hop relay terminal or an intermediate relay terminal (excluding the first hop relay terminal).

[0172] In scenario 1, for downlink transmission, in the communication link where the first terminal is located, there are at least two more hops after the first terminal; in other words, there is at least one hop between the first terminal and the remote terminal. For the first terminal, there may be a conflict between the local identifiers of at least two hops. The corresponding communication method for scenario 1 is as follows: Figure 11 As shown.

[0173] Figure 11 Flowchart of the communication method provided in the embodiments of this application Figure 1 This communication method is applicable to the aforementioned communication system and mainly involves the interaction between the first terminal and the access network equipment.

[0174] like Figure 11 As shown, the flow of this communication method is as follows:

[0175] S1101, the access network device sends a first message to the first terminal, and correspondingly, the first terminal receives the first message from the access network device.

[0176] The first message is used to configure the transmission channel, i.e., the data transmission exit channel after the first terminal subsequently receives data. The first message may include a first identifier and first information, which are used to identify the second terminal. The first message can be a downlink transmission message, for example, an RRC reconfiguration message. The RRC reconfiguration message contains sidelink SRAP configuration (which may be SL-SRAP-Config), used to configure the configurable SRAP parameters used by the UE. The configurable SRAP parameters may include the first identifier and first information. Of course, the first message can also be other RRC messages in the future; there are no restrictions on this.

[0177] The first identifier is used to locally identify the second terminal. For example, the first identifier may be the local ID of the second terminal, or other identifiers that can locally identify the second terminal. There are no restrictions on this.

[0178] The second terminal can be an intermediate relay terminal, with the first terminal providing relay services to the second terminal. The first terminal can be connected to the second terminal via a PC5 interface, meaning the second terminal is the next-hop terminal on the communication link / relay communication link where the first terminal is located. Alternatively, the first terminal and the second terminal can be connected via other relay devices.

[0179] The third terminal can be a remote terminal or an intermediate relay terminal, with the second terminal providing relay services to the third terminal.

[0180] The first identifier is the same as the identifier used to identify the third terminal locally; that is, the first identifier cannot uniquely identify the second terminal, for example, if the local IDs of both the second and third terminals are 1. Therefore, the second terminal can be jointly identified by the first identifier and the first information.

[0181] The first information may include a second identifier, wherein the second identifier of the second terminal is different from the second identifier of the third terminal.

[0182] The second identifier of the second terminal can be either the identifier of the transmission channel (denoted as transmission channel identifier #1) or the radio bearer identifier of the second terminal. Transmission channel identifier #1 corresponds to the second terminal. That is, transmission channel identifier #1 may differ from the transmission channel identifier corresponding to the third terminal (denoted as transmission channel identifier #2), or the radio bearer identifier of the second terminal may differ from the radio bearer identifier of the third terminal. Of course, it is also possible for transmission channel identifier #1 and transmission channel identifier #2 to differ, and for the radio bearer identifier of the second terminal to differ from the radio bearer identifier of the third terminal; this will not be elaborated upon further.

[0183] Optionally, transmission channel identifier #1 is used to identify the RLC channel of the link between the first terminal and the second terminal. Transmission channel identifier #1 can be the PC5 relay RLC channel identifier of the second terminal. Transmission channel identifier #1 is different from transmission channel identifier #2, which is used to identify the RLC channel of the link between the first terminal and the third terminal. For example, if the first message is an RRC reconfiguration message, and the access network device assigns the same local identifier (i.e., the first identifier) ​​to the second terminal and the third terminal, then the access network device configures the radio bearer data of the second terminal to be transmitted using a different RLC channel than that of the third terminal. It can be understood that different RLC channels correspond to different transmission channel identifiers.

[0184] For example, if the SL link local identifier (which can be sl-LocalIdentity) of the second terminal and the third terminal is the same, then the SL link transmission channel identifier (which can be SL-RLC-ChannelID) allocated by the access network equipment is different, and the SL egress RLC channel (which can be sl-EgressRLC-Channel) configuration is different.

[0185] For example, such as Figure 12 As shown, the first terminal is the last-hop relay terminal (denoted as UE1), the second terminal is the intermediate relay terminal (denoted as UE2), and the third terminal is the remote UE (denoted as UE3). The access network device (denoted as gNB) is connected to UE1 via the Uu interface, UE1 is connected to UE2 via PC5, and UE2 is connected to UE3 via PC5. The local IDs of UE2 and UE3 are both 1. UE1 receives RRC reconfiguration message #1 (i.e., the first message) from the gNB. RRC reconfiguration message #1 contains the local ID of UE2 and the PC5 relay RLC channel identifier #1 (i.e., transmission channel identifier #1) corresponding to UE2. This PC5 relay RLC channel identifier #1 is used to identify the channel between UE2 and UE1. The local IDs of UE2 and UE3 are the same, but the PC5 relay RLC channel identifier #1 of UE2 is different from the PC5 relay RLC channel identifier #2 of UE3. Therefore, UE1 can uniquely identify UE2 based on UE2's local ID and PC5 relay RLC channel identifier #1, or in other words, it can uniquely identify the egress RLC channel.

[0186] Of course, the first terminal can also be one of the intermediate relay terminals, which will not be elaborated on here.

[0187] It is understandable that the second and third terminals are distinguished by the transmission channel identifier #1, and the first terminal can subsequently identify data packets carrying the same local identifier (such as SRAP data packets) through different RLC channels. Furthermore, the upper limit of relay terminals or remote terminals served by a single relay terminal (such as the first terminal) is sufficiently high; for example, the number of available RLC channels is 512, meaning a single relay terminal can identify a maximum of 512 different RLC channels, which can meet the requirement of serving a maximum of 256 relay terminals or remote terminals simultaneously.

[0188] Optionally, the radio bearer identifier (such as RB ID) of the second terminal is used to identify the radio bearer (RB) of the second terminal. The radio bearer identifier of the third terminal is used to identify the radio bearer of the third terminal.

[0189] It is understandable that the radio bearer identifier of the second terminal is different from that of the third terminal. During subsequent data packet transmission (such as SRAP data packets), the radio bearer identifier can be included in the packet header.

[0190] Thus, the first terminal receives the first identifier and the radio bearer identifier of the second terminal through the first message. During subsequent data transmission, it can determine a unique second terminal based on the first identifier and the radio bearer identifier of the second terminal, i.e., determine a unique exit RLC channel (e.g., exit RLC channel #1). If the first terminal receives the first identifier and the radio bearer identifier of the third terminal through the first message, it can determine a unique third terminal based on the first identifier and the radio bearer identifier of the third terminal during subsequent data transmission, i.e., determine exit RLC channel #2, which is different from exit RLC channel #1. Furthermore, the radio bearer identifier can be carried in the packet header, which can improve the data packet transmission rate.

[0191] For example, continuing the above example, gNB and UE1 are connected via the Uu interface, UE1 and UE2 are connected via PC5, and UE2 and UE3 are connected via PC5. The local IDs of UE2 and UE3 are both 1. UE1 receives RRC reconfiguration message #1 (i.e., the first message) from gNB. RRC reconfiguration message #1 contains UE2's local ID and UE2's RB ID#1 (i.e., the radio bearer identifier of the second terminal). UE2's local ID is the same as UE3's local ID, but UE2's RB ID#1 is different from UE3's RB ID#2. Therefore, UE1 can uniquely identify UE2 based on UE2's local ID and RB ID#1, or in other words, can uniquely identify the egress RLC channel.

[0192] Optionally, the second terminal is uniquely identified by the first terminal.

[0193] For example, the second terminal can be the next-hop terminal in the communication link where the first terminal is located, and the first terminal can connect to the second terminal via a PC5 interface. The local identifier of the second terminal has a value range of 0-255. The local identifier of the second terminal can be uniquely identified by the first terminal.

[0194] It is understandable that the local identifiers of multiple terminals (including the second terminal) that are directly connected to the first terminal / PC5 ​​are not duplicated.

[0195] The first terminal can uniquely identify the second terminal. When the first terminal receives downlink transmitted data (such as SRAP data), it can determine that the unique egress RLC channel is the channel between the second terminal and the first terminal. In this embodiment, each terminal in the communication link (including relay terminals and remote terminals) can be uniquely identified by the previous hop terminal. Correspondingly, in the communication link, the local identifier of the next hop terminal of each hop terminal ranges from 0 to 255.

[0196] S1102, the first terminal sends a second message to the access network device, and correspondingly, the access network device receives the second message from the first terminal.

[0197] The second message is used in response to the first message. For example, if the first message is an RRC reconfiguration message, the second message could be an RRC reconfiguration complete message. Of course, the second message could also be any other RRC message used in response to the first message in the future, without any restrictions.

[0198] Thus, the first terminal receives a first message for configuring the transmission channel. The first message contains the first identifier and first information of the second terminal, enabling the first terminal to uniquely identify the second terminal. In other words, the first terminal can distinguish between the second terminal and the third terminal using the same local identifier through different second identifiers, avoiding local identifier conflicts caused by identical local identifiers between the second and third terminals in the communication link. Therefore, even if relay terminals with the same local identifier exist in the communication link, it can be guaranteed that data is successfully forwarded at each hop.

[0199] The process of configuring the transmission channel for the first terminal by the access network device has been introduced above. The following describes how the first terminal sends downlink data during the data transmission phase.

[0200] In one possible implementation, the access network device sends data to the first terminal, and correspondingly, the first terminal receives data from the access network device. The first terminal then sends data to the second terminal based on the first information.

[0201] Optionally, the first terminal sends data to the second terminal based on the first identifier and the first information.

[0202] It is understandable that, for the downlink transmission process, the data can be downlink data, such as downlink SRAP data packets. After the first terminal receives the data, since the data is associated with the first identifier and the first information, the first terminal determines the egress RLC channel used to send the data through the first identifier and the first information.

[0203] Optionally, if the first information includes a transmission channel identifier #1, then the first terminal sends data to the second terminal through the transmission channel identifier #1.

[0204] For example, continuing from the above Figure 12 For example, UE1 receives an SRAP data packet from the gNB. The SRAP data packet carries UE2's local ID and UE2's PC5 Relay RLC channel identifier #1. UE2's local ID is the same as UE3's local ID, but the PC5 Relay RLC channel identifier #1 for UE2 is different from the PC5 Relay RLC channel identifier #2 for UE3. Therefore, UE1 determines the SL egress RLC channel of the SRAP data packet based on the PC5 Relay RLC channel identifier #1. This SL egress RLC channel is the egress RLC channel of the link between UE1 and UE2. Then, UE1 sends the SRAP data packet to UE2 through the SL egress RLC channel.

[0205] Optionally, if the first information includes the radio bearer identifier of the second terminal, then the first terminal sends data to the second terminal through the radio bearer identifier of the second terminal.

[0206] For example, continuing from the above Figure 12 For example, UE1 receives an SRAP data packet from the gNB. UE2's local ID and RB ID#1 are carried in the header of the SRAP data packet. UE2's local ID is the same as UE3's local ID, but UE2's RB ID#1 is different from UE3's RB ID#2. UE1 determines the SL egress RLC channel based on UE2's RB ID#1. This SL egress RLC channel is the egress RLC channel of the link between UE1 and UE2. UE1 then sends the SRAP data packet to UE2 through the SL egress RLC channel.

[0207] It should be understood that the transmission channel identifier #1 and the radio bearer identifier of the second terminal can be used together. For example, the first terminal determines the SL egress RLC channel based on the PC5 relay RLC channel identifier and RB ID corresponding to the second terminal. The SL egress RLC channel is the egress RLC channel of the link between the first terminal and the second terminal. Then, the first terminal sends SRAP data packets to the second terminal through the SL egress RLC channel.

[0208] Optionally, if the second identifier is a radio bearer identifier, then the data, the first identifier, and the radio bearer identifier are carried in the first data unit. Alternatively, if the second identifier is an identifier of a transmission channel, then the first identifier and the data are carried in the first data unit, and the identifier of the transmission channel is carried in indication information separate from the first data unit.

[0209] It is understood that the first data unit can be an SRAP data PDU, or other possible data units, and there are no restrictions on this. If the first information includes a radio bearer identifier, then the first information is carried in the first data unit; if the first information includes a transmission channel identifier, then the first information is carried in indication information independent of the first data unit. Optionally, if the first information includes both a transmission channel identifier and a radio bearer identifier, then the radio bearer identifier is carried in the first data unit, and the transmission channel identifier is carried in indication information independent of the first data unit.

[0210] For example, when the first terminal receives an SRAP data packet, it determines the exit RLC channel based on the RB ID and local ID in the header of the SRAP data packet. If multiple exit RLC channels are determined, it further determines the unique exit RLC channel as the RLC channel between the first and second terminals based on the PC5 relay RLC channel identifier corresponding to the second terminal indicated by indication information independent of the SRAP data packet.

[0211] Thus, during relay communication, the first terminal can uniquely identify the second terminal based on the second terminal's first identifier and first information. In other words, by using different second identifiers to distinguish between the second terminal and the third terminal using the same local identifier, the problem of local identifier conflicts caused by the second and third terminals having the same local identifier in the communication link can be avoided. Therefore, when the first terminal receives data from the access network device or the relay terminal, it can ensure that each hop of data is successfully forwarded.

[0212] Case 2: The first terminal is the first hop relay terminal.

[0213] In other words, the first terminal serves the remote terminal. The second terminal can also be a remote terminal, and the first terminal provides relay services to the second terminal. The second terminal and the third terminal can be the same terminal. In this case, there will be no conflict between the local identifiers of the first terminal.

[0214] The process for the access network equipment to configure the transmission channel for the first terminal is as follows:

[0215] S11, the access network device sends a first message to the first terminal, and the first terminal receives the first message accordingly. The first message may include a first identifier and first information, which are used to identify the second terminal.

[0216] The first identifier is used to locally identify the second terminal, and the first information may include the second identifier, which is either the transmission channel identifier #1 or the radio bearer identifier. The first identifier, transmission channel identifier #1, and radio bearer identifier can also be found in the relevant description in S1101, and will not be repeated here.

[0217] S12, the first terminal sends a second message to the access network device, and the access network device receives the second message accordingly.

[0218] The second message is used in response to the first message.

[0219] It is understood that when the first terminal is the first hop relay terminal, there will be no conflict in the local identifier of the terminal. That is, the first terminal can uniquely identify the remote terminal (second terminal) that is being served. Therefore, the specific implementation of the access network equipment configuring the transmission channel for the first terminal can refer to the scheme of S1101. The scheme for the first terminal to transmit data can refer to the scheme of S1101 or the existing technology, which will not be elaborated here.

[0220] Scenario 3: The first terminal is a remote terminal.

[0221] In other words, the third terminal and the second terminal can be the same terminal as the first terminal, all of which are remote terminals. In this case, there will be no conflict in the local identifier of the first terminal.

[0222] The process for the access network equipment to configure the transmission channel for the first terminal is as follows:

[0223] S21, the access network device sends a first message to the first terminal, and the first terminal receives the first message accordingly. The first message may include a first identifier and first information, which are used to identify the first terminal.

[0224] The first identifier is used to locally identify the first terminal, and the first information may include a second identifier of the first terminal, which is either the transmission channel identifier or the radio bearer identifier of the first terminal. The transmission channel identifier of the first terminal is used to identify the RLC channel of the link between the first terminal and its previous hop terminal.

[0225] The first identifier can also refer to the description of the first identifier in S1101, and the radio bearer identifier can also refer to the description of the radio bearer identifier in S1101, which will not be repeated here.

[0226] S22, the first terminal sends a second message to the access network device, and the access network device receives the second message accordingly.

[0227] The second message is used in response to the first message.

[0228] It is understandable that when the first terminal is a remote terminal, there will be no conflict in the local identifier of the terminal. Therefore, the specific implementation of the access network device configuring the transmission channel for the first terminal can refer to the scheme of S1101, and the scheme for the first terminal to transmit data can refer to the scheme of S1101 or existing technology, which will not be elaborated here.

[0229] The following section introduces the uplink transmission process in multi-hop relay communication scenarios.

[0230] In a multi-hop relay communication scenario, the communication link includes access network equipment, last-hop relay terminal, at least one intermediate relay terminal (including the first-hop relay terminal), and remote terminal. The following discusses different data transmission scenarios where the first terminal is of different terminal types, such as scenario 4 and scenario 5.

[0231] Case 4: The first terminal is the last hop relay terminal or an intermediate relay terminal (excluding the first hop relay terminal).

[0232] In other words, in the communication link where the first terminal is located, there are at least two more hop terminals after the first terminal. It should be understood that the next-hop terminal in this application embodiment refers to the next-hop terminal in the communication link. For example, if the first terminal provides relay service to the second terminal and is connected to the second terminal via PC5, then the second terminal is the next-hop terminal of the first terminal. For the first terminal, during uplink transmission, there may be a conflict between the local identifiers of the terminals associated with the received uplink data packets.

[0233] In one possible implementation, the second terminal sends data, a first identifier, and first information to the first terminal, and correspondingly, the first terminal receives data, the first identifier, and the first information from the second terminal. Based on the first information, the first terminal sends data to its upstream terminal.

[0234] The second terminal can be an intermediate relay terminal, with the first terminal providing relay services to the second terminal. The first terminal can be connected to the second terminal via a PC5 interface, meaning the second terminal is the next-hop terminal on the communication link / relay communication link where the first terminal is located. Alternatively, the first terminal and the second terminal can be connected via other relay devices.

[0235] The data in question is uplink data. After receiving the data, the first terminal determines the egress RLC channel for transmitting the data based on the association between the data and the first identifier and the first information.

[0236] The first identifier is used to locally identify the second terminal and is the same as the identifier used to locally identify the third terminal. The first identifier can be found in the relevant description in S1101, and will not be repeated here. The third terminal can be a remote terminal / intermediate relay terminal, and the second terminal provides relay services to the third terminal.

[0237] The first information may include a second identifier, which is either the transmission channel identifier #1 or the radio bearer identifier of the second terminal. The transmission channel identifier #1 is different from the transmission channel identifier #2, or the radio bearer identifier of the second terminal is different from the radio bearer identifier of the third terminal. Of course, it is also possible that the transmission channel identifier #1 is different from the transmission channel identifier #2, and the radio bearer identifier of the second terminal is different from the radio bearer identifier of the third terminal; this will not be elaborated upon.

[0238] Optionally, the transmission channel identifier #1 is used to identify the RLC channel of the link between the first terminal and its upstream terminal. For example, the transmission channel identifier #1 is a PC5 relay RLC channel identifier, used to indicate the PC5 relay RLC channel between the first terminal and its upstream terminal.

[0239] Optionally, if the second terminal is the last-hop relay terminal, then the transmission channel identifier #1 is used to identify the RLC channel of the link between the first terminal and the access network device. For example, the transmission channel identifier #1 is a Uu relay RLC channel identifier, used to indicate the Uu relay RLC channel between the first terminal and the access network device.

[0240] The wireless bearer identifier of the second terminal can be found in the relevant description in S1101, and will not be repeated here.

[0241] Optionally, the first terminal sends data to the second terminal based on the first identifier and the first information.

[0242] For example, if the first information includes a transmission channel identifier #1, then the first terminal can uniquely identify the second terminal through the transmission channel identifier #1, that is, identify that the data comes from the second terminal. The first terminal determines the egress RLC transmission channel (denoted as channel #1) based on the transmission channel identifier #1, and sends data to the upstream terminal (or access network equipment) of the first terminal through the egress RLC transmission channel.

[0243] It is understandable that if the first terminal receives data from the third terminal, and the data from the third terminal is associated with transmission channel identifier #2, then the exit RLC transmission channel (denoted as channel #2) determined by the first terminal according to transmission channel identifier #2 is different from channel #1, so that the upstream terminal (or access network device) of the first terminal can identify data from different terminals.

[0244] For example, if the first information includes the radio bearer identifier of the second terminal, then the first terminal can uniquely identify the second terminal through the radio bearer identifier, that is, identify that the data comes from the second terminal. The first terminal determines the egress RLC transmission channel (denoted as channel #1) based on the radio bearer identifier of the second terminal, and sends data to the upstream terminal of the first terminal through the egress RLC transmission channel.

[0245] It is understandable that if the first terminal receives data from the third terminal, and the data from the third terminal is associated with the radio bearer identifier of the third terminal, then the egress RLC transmission channel (denoted as channel #2) determined by the first terminal based on the radio bearer identifier of the third terminal is different from channel #1, so that the upstream terminal (or access network device) of the first terminal can identify data from different terminals.

[0246] It should be understood that the identification of the transmission channel and the radio bearer identification can be used in combination. For example, the first terminal determines the SL egress RLC channel based on the PC5 relay RLC channel identification and RB ID of the second terminal. The SL egress RLC channel is the egress RLC channel of the link between the first terminal and the previous hop terminal of the first terminal. Then, the first terminal sends data to the previous hop terminal (or access network equipment) of the first terminal through the SL egress RLC channel.

[0247] Thus, during relay communication, the first terminal can uniquely identify the second terminal based on the first identifier and first information associated with the data. In other words, by using different second identifiers to distinguish between the second and third terminals using the same local identifier, the problem of local identifier conflicts caused by the second and third terminals having the same local identifier in the communication link can be avoided. Therefore, when the first terminal receives data from a remote terminal or relay terminal, it can ensure that each hop of data is successfully forwarded.

[0248] Case 5: The first terminal is the first hop relay terminal.

[0249] In other words, the first terminal serves the remote terminal. The second terminal can also be a remote terminal, and the first terminal provides relay services to the second terminal. The second terminal and the third terminal can be the same terminal. In this case, after receiving data, the first terminal can uniquely identify the second terminal based on its local identifier, meaning there will be no conflict between the terminal's local identifiers.

[0250] The scheme for the first terminal to transmit uplink data can refer to the scheme in case 4 or refer to existing technologies, which will not be elaborated here.

[0251] The above combination Figures 11-12 The overall flow of the communication method provided in the embodiments of this application is described below. Figure 13This application provides a detailed description of the communication method provided in specific application scenarios.

[0252] Figure 13 Flowchart of the communication method provided in the embodiments of this application Figure 2 . Figure 13 The process shown mainly involves the interaction between the remote UE, the intermediate relay UE, the last-hop relay UE, and the gNB.

[0253] For scenario 1 above: the remote UE is the third terminal mentioned above, the intermediate relay UE is the second terminal mentioned above, and the last hop relay UE is the first terminal mentioned above.

[0254] Specifically, such as Figure 13 As shown, the flow of this communication method is as follows:

[0255] S1301a, gNB sends RRC reconfiguration message #1 (i.e. the first message mentioned above) to the last hop relay UE.

[0256] Correspondingly, the last-hop relay UE receives RRC reconfiguration message #1 from the gNB.

[0257] The RRC reconfiguration message #1 includes a sidelink SRAP configuration (which can be SL-SRAP-Config). This sidelink SRAP configuration is used to configure the configurable SRAP parameters used by the UE, and may include the local ID #1 of the intermediate relay UE (i.e., the first identifier mentioned above). The RRC reconfiguration message #1 may also include the PC5 relay RLC channel identifier #1 of the intermediate relay UE (i.e., the transmission channel identifier #1 mentioned above), and / or the RB ID #1 of the intermediate relay UE (i.e., the radio bearer identifier of the second terminal mentioned above).

[0258] In this context, the local ID#1 of the intermediate relay UE is the same as the local ID#2 of the remote UE. If RRC reconfiguration message #1 includes PC5 relay RLC channel identifier #1, then PC5 relay RLC channel identifier #1 is different from the PC5 relay RLC channel identifier #2 of the remote UE. If RRC reconfiguration message #1 includes RB ID#1, then RB ID#1 is different from the RB ID#2 of the remote UE.

[0259] The local ID #1 of the intermediate relay UE can be found in the description of the first identifier in S1101, and will not be repeated here. The PC5 relay RLC channel identifier #1 can be found in the description of the transmission channel identifier #1 in S1101, and will not be repeated here. The RB ID #1 of the intermediate relay UE can be found in the description of the radio bearer identifier of the second terminal in S1101, and will not be repeated here.

[0260] S1302a, the last-hop relay UE sends an RRC reconfiguration complete message #1 to the gNB.

[0261] Accordingly, the gNB receives RRC reconfiguration complete message #1 from the last-hop relay UE.

[0262] Thus, during relay communication, when the last-hop relay UE receives the sidelink SRAP configuration in the RRC reconfiguration message from the gNB, the subsequent last-hop relay UE can uniquely identify the intermediate relay UE based on the local identifier of the intermediate relay UE, as well as RB ID#1 and / or PC5 relay RLC channel identifier#1. This ensures that data is successfully forwarded at each hop.

[0263] Regarding scenario 2 above: the remote UE is the second / third terminal mentioned above, and the intermediate relay UE (specifically the first hop relay UE) is the first terminal mentioned above.

[0264] S1301b, gNB sends RRC reconfiguration message #2 (i.e. the first message mentioned above) to the intermediate relay UE.

[0265] Correspondingly, the intermediate relay UE receives RRC reconfiguration message #2 from the gNB.

[0266] The RRC reconfiguration message #2 includes a sidelink SRAP configuration (which can be SL-SRAP-Config). This sidelink SRAP configuration is used to configure the configurable SRAP parameters used by the UE. The configurable SRAP parameters may include the remote UE's local ID #1 (i.e., the first identifier mentioned above). The RRC reconfiguration message #2 may also include the remote UE's PC5 relay RLC channel identifier #1 (i.e., the transmission channel identifier #1 mentioned above), and / or the remote UE's RB ID #1 (i.e., the radio bearer identifier of the second terminal mentioned above).

[0267] Specifically, the local ID #1 of the remote UE can be found in the description of the first identifier in S1101, and will not be repeated here. The PC5 relay RLC channel identifier #1 can be found in the description of the transmission channel identifier #1 in S1101, and will not be repeated here. The RB ID #1 of the remote UE can be found in the description of the radio bearer identifier of the second terminal in S1101, and will not be repeated here.

[0268] S1302b, the intermediate relay UE sends an RRC reconfiguration complete message #2 to the gNB.

[0269] Regarding scenario 3 above: The remote UE is the first terminal mentioned above, and the third terminal and the second terminal can be the same terminal as the first terminal.

[0270] S1301c, gNB sends RRC reconfiguration message #3 (i.e. the first message mentioned above) to the remote UE.

[0271] Correspondingly, the intermediate relay UE receives RRC reconfiguration message #3 from the gNB.

[0272] The RRC reconfiguration message #3 includes a sidelink SRAP configuration (which can be SL-SRAP-Config). This sidelink SRAP configuration is used to configure the configurable SRAP parameters used by the UE. The configurable SRAP parameters may include the remote UE's local ID #1 (i.e., the first identifier mentioned above). The RRC reconfiguration message #3 may also include the remote UE's PC5 relay RLC channel identifier #1 (i.e., the transmission channel identifier #1 mentioned above), and / or the remote UE's RB ID #1 (i.e., the radio bearer identifier of the second terminal mentioned above).

[0273] Specifically, the local ID #1 of the remote UE can be found in the description of the first identifier in S1101, and will not be repeated here. The PC5 relay RLC channel identifier #1 can be found in the description of the transmission channel identifier #1 in S1101, and will not be repeated here. The RB ID #1 of the remote UE can be found in the description of the radio bearer identifier of the second terminal in S1101, and will not be repeated here.

[0274] S1302c, the remote UE sends an RRC reconfiguration complete message #3 to the gNB.

[0275] S1303, data transmission occurs between the remote UE, intermediate relay UE, last-hop relay UE and gNB.

[0276] S1303 is an optional step. Data transmission, including uplink data transmission or downlink data transmission, occurs between the remote UE, intermediate relay UE, last-hop relay UE, and gNB according to the aforementioned RRC reconfiguration message.

[0277] The above describes the scheme for configuring a transmission channel for the first terminal in the access network device, as well as the data forwarding process. The following describes the scheme for ensuring that the DU and CU can uniquely identify the relay terminal / remote terminal in the scenario where the DU and CU are separated in the access network device.

[0278] Figure 14 Flowchart of the communication method provided in the embodiments of this application Figure 3 This communication method is applicable to the aforementioned communication system and mainly involves the interaction between the first and second units of the access network equipment. It can be understood that terms such as "first" and "second" are expressions at the granularity of an embodiment, such as... Figure 11 In the corresponding embodiment, "first message" and Figure 14 The content indicated by "first message" may differ in the corresponding embodiments, which will not be elaborated here.

[0279] like Figure 14As shown, the flow of this communication method is as follows:

[0280] S1401, the second unit of the access network device sends a first message to the first unit of the access network device, and correspondingly, the first unit of the access network device receives the first message from the second unit of the access network device.

[0281] The first message is used to assign a first local identifier to the first terminal. For example, the first message may be an RRC message during the initial access process of the first terminal. Optionally, the first message may also be used to determine the configuration of the relay RLC channel for the first terminal.

[0282] The first local identifier is the same as the second local identifier of at least one terminal, and at least one terminal provides relay services to the first terminal. That is, at least one terminal requests access to the access network device before the first terminal. Before assigning the first local identifier to the first terminal, the access network device assigns the second local identifier to at least one terminal in the order in which they request access to the access network device, and the first local identifier is the same as the second local identifier.

[0283] S1402, the first unit sends a second message to the second unit, and correspondingly, the second unit receives the second message from the first unit.

[0284] The second message is used to identify the first terminal. The second message may also include the first local identifier of the first terminal and the gNB-DU UE F1AP ID of the last hop relay terminal in the communication link where the first terminal is located.

[0285] Optionally, the second message is an RRC establishment request message for the first terminal. For example, the second message is an initial uplink RRC message transmission message during the RRC establishment request process of the first terminal.

[0286] Optionally, the first message can also be an RRC message for path handover, such as a terminal connection establishment request (which could be a UE CONTEXT SETUP REQUEST message). This path handover can be a handover across DUs within the same CU, such as a handover from a source DU managed by the CU (i.e., the second unit) to a target DU (i.e., the first unit) for the first terminal. For example, for a handover within the same access network device, the first terminal may switch from a direct connection to the access network device (i.e., direct connection) to a connection via a one-hop or multi-hop relay terminal (i.e., multi-hop non-direct connection). Another example is a handover within the same access network device, where the first terminal switches from a connection via a one-hop relay terminal (i.e., single-hop non-direct connection) to a connection via a multi-hop relay terminal (i.e., multi-hop non-direct connection).

[0287] The first message used for path switching may include an identifier that the first terminal can be uniquely identified within the second unit, such as gNB-CU UE F1AP ID.

[0288] Optionally, the communication method may further include: the first unit sending a third message to the second unit, the third message being a response to the first message, the third message being an RRC message for path switching, such as a terminal connection establishment response (which may be a UE CONTEXT SETUP RESPONSE message). The third message may include an identifier that can be uniquely identified by the first terminal within the first unit, such as the gNB-DU UE F1AP ID.

[0289] Therefore, in the scenario where the first message is used for path switching, after the first unit uniquely identifies the first terminal, the second message sent to the second unit carries an identifier that can be uniquely identified within the first unit, such as the gNB-DU UE F1AP ID, so that the first unit can uniquely identify the first terminal. Therefore, in the scenario where the first message is used for path switching, the second message may include information used to determine the first terminal as described later, or it may be implemented using existing technology.

[0290] The following describes several implementation methods for the first unit to uniquely identify the first terminal, and for the second message to determine the first terminal.

[0291] Implementation method 1: The first terminal is identified by the transmission channel identifier of the first terminal.

[0292] Optionally, the second message may include a transmission channel identifier of the first terminal, which identifies the RLC channel of the link between the second terminal and the first terminal, and the second terminal provides relay services to the first terminal. The transmission channel identifier of the first terminal is different from the transmission channel identifier of at least one terminal.

[0293] The second terminal can be the upstream terminal of the first terminal in the communication link between the second terminal and the first terminal, or in other words, the first terminal and the second terminal are connected via PC5. The transmission channel identifier of the first terminal can be the PC5 relay RLC channel identifier of the first terminal. The transmission channel identifier of the first terminal can also refer to the description of the transmission channel identifier #1 in S1101, which will not be repeated here.

[0294] It is understood that at least one terminal may or may not include a second terminal, and there is no restriction on this.

[0295] Thus, the second unit can uniquely identify the first terminal based on the transmission channel identifier of the first terminal. For example, after receiving the second message, the second unit can store the transmission channel identifier of the first terminal in the second message, and determine the first terminal based on the transmission channel identifier and the first local identifier, and then send an RRC establishment message to the first terminal through the first unit. Alternatively, the second unit can determine that the SRAP data PDU comes from the first terminal based on the transmission channel identifier of the first terminal corresponding to the received SRAP data PDU, thus uniquely identifying the first terminal. Optionally, after determining that the SRAP data PDU comes from the first terminal, the SRAP data PDU is associated with the transmission channel identifier and the layer 2 identifier of the first terminal.

[0296] Accordingly, the first message may include the transmission channel identifier of the first terminal. That is, when the second unit of the access network device allocates the local identifier of the first terminal through the first message, it also sends the transmission channel identifier of the first terminal to the first unit through the first message. Thus, when the first unit receives the SRAP data PDU, it can identify the first terminal by combining the transmission channel identifier of the first terminal with the first local identifier. For example, the transmission channel identifier of the first terminal may be carried in the configuration of the first terminal's Uu relay RLC channel (which may be a Uu relay RLC channel).

[0297] For example, Figure 14 Corresponding embodiments and Figure 11 The corresponding embodiments are combined. If the second unit of the access network device assigns the same local identifier (i.e., the first local identifier and the second local identifier) ​​to the first terminal and at least one terminal, then the second unit configures the radio bearer data of the first terminal to be transmitted using a different RLC channel than that of the at least one terminal. For example, when the access network device transmits the RRC reconfiguration message of the first terminal, the first unit of the access network device uses a different RLC channel than that of the at least one terminal to transmit the RRC reconfiguration message of the first terminal. It can be understood that different RLC channels correspond to different transmission channel identifiers.

[0298] Implementation method 2: The first terminal is determined by the layer 2 identifier of the first terminal.

[0299] Optionally, the second message may include first indication information, which indicates the mapping / correspondence between the first local identifier and the Layer 2 identifier of the first terminal. At least one terminal's Layer 2 identifier is different from the first terminal's Layer 2 identifier. Thus, the second unit can identify the first terminal based on the correspondence between the first local identifier and the first terminal's Layer 2 identifier.

[0300] For example, after receiving the second message, the second unit can store the correspondence between the first local identifier and the Layer 2 identifier of the first terminal in the second message, and send an RRC establishment message to the first terminal through the first unit. Alternatively, the second unit can determine that the SRAP data PDU comes from the first terminal by associating it with the correspondence between the first local identifier and the Layer 2 identifier of the first terminal, thus uniquely identifying the first terminal. Optionally, after determining that the SRAP data PDU comes from the first terminal, the SRAP data PDU is associated with the Layer 2 identifier of the first terminal.

[0301] Correspondingly, the first message may also include first indication information. That is, when the second unit of the access network device allocates the local identifier of the first terminal through the first message, it also sends the first indication information to the first unit through the first message, so that when the first unit receives the SRAP data PDU, it can identify the first terminal through the correspondence between the first local identifier and the Layer 2 identifier of the first terminal.

[0302] Implementation method 3: Determine the first terminal through path information.

[0303] Optionally, the second message may include path information, which can be used to indicate the previous-hop terminal and the next-hop terminal of each terminal in the communication link / relay communication link between the first terminal and the access network device. Specifically, the second message may include the local identifier of the previous-hop terminal and the local identifier of the next-hop terminal of each terminal in the aforementioned communication link. The path information corresponding to at least one terminal is different from the path information corresponding to the first terminal.

[0304] Optionally, the path information can be used to indicate the path in which the first terminal is located, such as the second message including an identifier of the path in which the first terminal is located. Alternatively, the path information can also be used to indicate the number of hops in the path in which the first terminal is located, such as the second message including the i-th hop of the first terminal in the path in which it is located, where i is an integer greater than or equal to 1.

[0305] Thus, after receiving the second message, the second unit can store the path information in the second message and uniquely identify the first terminal based on the path information and the first local identifier, and then send an RRC establishment message to the first terminal through the first unit. Alternatively, after receiving the SRAP data PDU, the second unit can determine that the SRAP data PDU comes from the first terminal based on the path information corresponding to the SRAP data PDU, thus uniquely identifying the first terminal. Optionally, after determining that the SRAP data PDU comes from the first terminal, the SRAP data PDU is associated with the path information and the Layer 2 identifier of the first terminal.

[0306] Correspondingly, the first message may also include path information. That is, when the second unit of the access network device allocates the local identifier of the first terminal through the first message, it also sends the path information to the first unit through the first message, so that the first unit can identify the first terminal through the first local identifier and the path information when it receives the SRAP data PDU.

[0307] Implementation method 4: Determine the first terminal through the local identifier of the second terminal.

[0308] Optionally, the second message may include second indication information, which indicates the local identifier of the second terminal. The first terminal is a remote terminal, and the second terminal provides relay services to the first terminal. The second terminal may be the first-hop relay terminal of the communication link where the first terminal is located, that is, the first terminal and the second terminal are directly connected. The second unit indicates to the first unit through the second indication information that the first terminal corresponding to the first local identifier is a terminal connected to the second terminal. The local identifier of the second terminal is different from the first local identifier.

[0309] Thus, after receiving the second message, the second unit can store the local identifier of the second terminal in the second message, and determine the first-hop relay terminal as the second terminal based on the local identifier of the second terminal. The first unit then sends an RRC establishment message to the second terminal, and subsequently, the second terminal sends an RRC establishment message to the first terminal. Alternatively, after receiving the SRAP data PDU, the second unit determines the first-hop relay terminal corresponding to the SRAP data PDU as the second terminal based on the local identifier of the second terminal corresponding to the SRAP data PDU. This uniquely identifies the second terminal, and since the local identifier of the second terminal is different from the first local identifier, the first terminal can be uniquely identified by identifying the first-hop relay terminal as the second terminal. Optionally, after determining that the first-hop relay terminal from which the SRAP data PDU comes is the second terminal, the SRAP data PDU is associated with the local identifier of the second terminal and the Layer 2 identifier of the first terminal.

[0310] Correspondingly, the first message may include second indication information. That is, when the second unit of the access network device allocates the local identifier of the first terminal through the first message, it also sends the second indication information to the first unit through the first message, so that when the first unit receives the SRAP data PDU, it can determine that the first hop relay terminal corresponding to the SRAP data PDU is the second terminal by comparing the first local identifier with the local identifier of the second terminal.

[0311] Thus, during relay communication, the second unit of the access network device sends a second message to the first unit to identify the first terminal. This allows the first unit to uniquely identify the first terminal based on the second message when the first local identifier of the first terminal is the same as the local identifier of at least one terminal. This avoids the problem of local identifier conflict caused by the existence of terminals with the same local identifier in the communication link, and also avoids the failure of the first terminal's initial access process.

[0312] It is understandable that the specific implementations of S1401-S1402 can also refer to the specific implementations of S1101-S1102, and will not be elaborated further.

[0313] The various implementation methods in the embodiments of this application can be used in combination, and the combination form of the various implementation methods in the above embodiments is not limited.

[0314] The above combination Figure 14 The overall flow of the communication method provided in the embodiments of this application is described below. Figure 15 This application provides a detailed description of the communication method provided in specific application scenarios.

[0315] Figure 15 Flowchart of the communication method provided in the embodiments of this application Figure 4 . Figure 15 The process shown mainly involves the interaction between the remote UE (such as the first terminal mentioned above), the intermediate relay UE (including at least one terminal and the second terminal mentioned above), the last-hop relay UE, the gNB-DU (such as the first unit mentioned above), and the gNB-CU (such as the second unit mentioned above).

[0316] Specifically, such as Figure 15 As shown, the flow of this communication method is as follows:

[0317] S1500, the remote UE and the intermediate relay UE perform a discovery process and establish a PC5 connection.

[0318] S1501, the remote UE sends an RRC establishment request message to the last-hop relay UE through the intermediate relay UE.

[0319] S1502, the last-hop relay UE sends a sidelink UE information NR (which may be a SidelinkUEInformationNR) message to the gNB-DU.

[0320] The last-hop relay UE temporarily stores the received RRC establishment request message and sends a side-link UE information NR message to the gNB-DU.

[0321] S1503, gNB-DU and gNB-CU exchange information to complete the local ID allocation for the remote UE.

[0322] Furthermore, the gNB-DU and gNB-CU exchange information to complete the configuration of the Uu relay RLC channel. For example, the local ID #1 assigned by the gNB-CU to the remote UE is the same as the local ID assigned to at least one of the intermediate relay UEs.

[0323] The gNB-CU sends first information (as described above) to the gNB-DU. The first information includes at least one of the following: the PC5 relay RLC channel identifier of the remote UE (i.e., the transmission channel identifier of the first terminal), the correspondence between the local ID and L2 ID of the remote UE, path information, or the local ID of the first-hop relay UE. The intermediate relay UE may include the first-hop relay UE.

[0324] Specifically, the PC5 relay RLC channel identifier of the remote UE can be referred to in S1501 for the description of the transmission channel identifier of the first terminal, and will not be repeated here. The correspondence between the local ID and L2 ID of the remote UE can be referred to in S1501 for the description of the correspondence between the first local identifier and the Layer 2 identifier of the first terminal, and will not be repeated here. The path information can be referred to in S1501 for the description of the path information, and will not be repeated here. The local ID of the first-hop relay UE can be referred to in S1501 for the description of the local identifier of the second terminal, and will not be repeated here.

[0325] S1504, gNB-DU sends an RRC reconfiguration (which may be RRCReconfiguration) message to the last-hop relay UE.

[0326] The RRC reconfiguration message is used to configure the remote UE's local ID, Uu relay RLC channel, and SRB0 bearer mapping. The RRC reconfiguration message includes the remote UE's local ID. Furthermore, the RRC reconfiguration message also includes first information, namely, at least one of the following: the remote UE's PC5 relay RLC channel identifier, the mapping between the remote UE's local ID and L2 ID, path information, or the local ID of the first-hop relay UE.

[0327] S1505, the last-hop relay UE sends an RRC reconfiguration complete (or RRCReconfigurationComplete) message to the gNB-DU.

[0328] S1506, gNB-DU sends an uplink RRC message transmission (which may be a UL RRC MESSAGETRANSFER message) to gNB-CU.

[0329] Specifically, gNB-DU encapsulates the RRC reconfiguration completion message and sends the aforementioned uplink RRC message transmission message to gNB-CU.

[0330] S1507, the last-hop relay UE sends an RRC establishment request message to the gNB-DU.

[0331] This RRC establishment request message is an RRC establishment request message for the remote UE.

[0332] After receiving the remote UE's local ID, Uu relay RLC channel configuration, and SRB0 bearer mapping for the remote UE via the RRC reconfiguration message, the relay UE sends the remote UE's RRC establishment request message to the gNB-DU. The remote UE's local ID and the SRB's RB ID are transmitted in the header of the SRAP data packet.

[0333] S1508, gNB-DU sends an initial uplink RRC message transmission (which may be INITIAL UL RRCMESSAGE TRANSFER) message to gNB-CU.

[0334] The initial uplink RRC message transmission message may include the local ID of the remote UE and the gNB-DUUE F1AP ID of the last-hop relay UE. The initial uplink RRC message transmission message may also include first information, namely, at least one of the following: the PC5 relay RLC channel identifier of the remote UE, the correspondence between the remote UE's local ID and L2 ID, path information, or the local ID of the first-hop relay UE.

[0335] Therefore, after the gNB-CU receives the initial uplink RRC message transmission message, it can determine the remote UE corresponding to the received SRAP data packet, that is, uniquely identify the remote UE.

[0336] S1509, gNB-CU sends a downlink RRC message transmission message to gNB-DU.

[0337] The gNB-CU generates an RRC setup (or RRCSetup) message, which is then encapsulated in a downlink RRC message transmission message.

[0338] Specifically, the gNB-CU assigns a UE-related logical F1 interface identifier (which can be the gNB-CU UEF1AP ID) to the remote UE and generates an RRC establishment message pointing to the remote UE. At this point, the gNB-CU can accurately distinguish the remote UE corresponding to the RRC establishment message through the first information.

[0339] S1510, gNB-DU sends RRC establishment messages to the remote UE through the last-hop relay UE and intermediate relay UE.

[0340] gNB-DU can also accurately distinguish the remote UE corresponding to the RRC establishment message. The remote UE begins the RRC connection establishment process.

[0341] Figure 16 Flowchart of the communication method provided in the embodiments of this application Figure 5 This communication method is applicable to the aforementioned communication system and mainly involves the interaction between access network equipment, the first terminal, and the second terminal.

[0342] like Figure 16 As shown, the flow of this communication method is as follows:

[0343] S1601, the access network device sends data, a first identifier, and first information to the first terminal.

[0344] Accordingly, the first terminal receives data, a first identifier, and first information from the access network device.

[0345] The first identifier and the first information are used to identify the second terminal. The first identifier is used to locally identify the second terminal, and the first identifier is the same as the identifier used to locally identify the third terminal. The first information is used to determine the second terminal.

[0346] The first identifier can be referred to in the description of the first identifier in S1101, and will not be repeated here. The first information can be referred to in the description of the first information in S1101, and will not be repeated here. The second terminal and the third terminal can be referred to in the description of the second terminal and the third terminal in S1101, and will not be repeated here.

[0347] S1602, the first terminal sends data to the second terminal, and correspondingly, the second terminal receives data from the first terminal.

[0348] Optionally, the first information may include an identifier of a transmission channel, which is used to identify the RLC channel of the link between the first terminal and the second terminal. The identifier of the transmission channel is different from the identifier of the transmission channel of the third terminal, which is used to identify the RLC channel of the link between the first terminal and the third terminal.

[0349] The identification of the transmission channel can be found in the description of transmission channel identifier #1 in S1101, and will not be repeated here.

[0350] Optionally, the first terminal can transmit data to the first terminal through the RLC channel of the link between the first terminal and the second terminal.

[0351] Optionally, the first information may include the radio bearer identifier of the second terminal, which is different from the radio bearer identifier of the third terminal. The radio bearer identifier of the second terminal can be found in the description of the radio bearer identifier of the second terminal in S1101, and will not be repeated here.

[0352] Optionally, the first information may include the Layer 2 identifier of the second terminal. The Layer 2 identifier of the second terminal corresponds to the first identifier. For example, by extending the SRAP data packet, a Layer 2 identifier, such as a 24-bit L2ID, is added to the SRAP data packet.

[0353] Optionally, the first information may include hop count information, which indicates that the first terminal is the Nth hop terminal in the communication link / relay communication link between the first terminal and the access network device, where N is an integer greater than or equal to 1. The hop count information may also be used to indicate the total number of hops in the communication link / relay communication link between the first terminal and the access network device, without limitation.

[0354] For example, SRAP packets can be extended by adding hop count information. For instance, 4 bits can be used to represent up to 16 hop terminals, or the number of bits can be further increased to represent more hop terminals.

[0355] Optionally, the first information may include path information, which is used to indicate the previous hop terminal and the next hop terminal of each terminal in the relay communication link between the first terminal and the access network device.

[0356] For example, SRAP packets can be extended by adding path information, such as using 16 bits to represent the local identifiers of the previous and next hop terminals for each hop terminal.

[0357] Optionally, if the first information includes the radio bearer identifier of the second terminal, then the data, the first identifier, and the radio bearer identifier of the second terminal are carried in the first data unit; or, if the first information includes the identifier of the transmission channel, then the first identifier and the data are carried in the first data unit, and the identifier of the transmission channel is carried in indication information independent of the first data unit.

[0358] For example, by directly adding bits to existing SRAP data packets, i.e., carrying the first information within the SRAP data packet, a new format for multi-hop scenarios can be defined. Alternatively, without changing the existing SRAP data packet format, an associated indication message carrying the first information can be sent along with the SRAP data packet.

[0359] In the embodiments of this application, the contents of the first information can be used in combination. For example, the first information may include the identifier of the transmission channel and the wireless bearer identifier of the second terminal, or the first information may include the identifier of the transmission channel, the wireless bearer identifier of the second terminal, and hop count information, etc. The combination form is not limited.

[0360] Figure 17This is a flowchart illustrating the communication method under the O-RAN architecture. (For example...) Figure 17 As shown, the process includes S1701a-S1704c, as detailed below:

[0361] S1701a, the O-DU sends the RRC reconfiguration message corresponding to the remote UE to the O-RU.

[0362] Alternatively, the O-CU sends an RRC reconfiguration message corresponding to the remote UE to the O-RU. The description of the RRC reconfiguration message for the remote UE in S1101 above is provided and will not be repeated here.

[0363] S1702a, the O-RU sends the RRC reconfiguration message corresponding to the remote UE to the remote UE.

[0364] S1703a, the remote UE sends an RRC reconfiguration completion message corresponding to the remote UE to the O-RU.

[0365] S1704a, the O-RU sends an RRC reconfiguration completion message corresponding to the remote UE to the O-DU.

[0366] If the decision is made by the O-CU, then the O-DU will pass the RRC reconfiguration completion message corresponding to the remote UE to the O-CU.

[0367] S1701b, the O-DU sends the RRC reconfiguration message corresponding to the intermediate relay UE to the O-RU.

[0368] Alternatively, the O-CU sends an RRC reconfiguration message corresponding to the intermediate relay UE to the O-RU. The RRC reconfiguration message can be found in the description of the RRC reconfiguration message in S1101 above, and will not be repeated here.

[0369] S1702b, the O-RU sends the RRC reconfiguration message corresponding to the intermediate relay UE to the intermediate relay UE.

[0370] S1703b, the intermediate relay UE sends an RRC reconfiguration completion message corresponding to the intermediate relay UE to the O-RU.

[0371] S1704b, the O-RU sends an RRC reconfiguration completion message to the O-DU corresponding to the intermediate relay UE.

[0372] If the decision is made by the O-CU, then the O-DU will pass the RRC reconfiguration completion message corresponding to the intermediate relay UE to the O-CU.

[0373] S1701c, the O-DU sends the RRC reconfiguration message corresponding to the last-hop relay UE to the O-RU.

[0374] Alternatively, the O-CU sends an RRC reconfiguration message corresponding to the last-hop relay UE to the O-RU. The RRC reconfiguration message can be found in the description of the RRC reconfiguration message in S1101 above, and will not be repeated here.

[0375] S1702c, the O-RU sends the RRC reconfiguration message corresponding to the last-hop relay UE to the last-hop relay UE.

[0376] S1703c, the last-hop relay UE sends an RRC reconfiguration completion message corresponding to the last-hop relay UE to the O-RU.

[0377] S1704b, the O-RU sends an RRC reconfiguration completion message to the O-DU corresponding to the last-hop relay UE.

[0378] If the decision is made by the O-CU, then the O-DU will pass the RRC reconfiguration completion message corresponding to the last-hop relay UE to the O-CU.

[0379] The above combination Figures 11-17 The methods provided in the embodiments of this application are described in detail below. Figures 18-19 This document describes in detail the communication apparatus used to perform the communication method provided in the embodiments of this application.

[0380] Figure 18 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application. Figure 1 For example, such as Figure 18 As shown, the communication device 1800 includes a transceiver module 1801 and a processing module 1802. For ease of explanation, Figure 18 Only the main components of the communication device are shown.

[0381] The transceiver module 1801 is used to perform the above. Figure 11 , Figure 14 ,or Figure 16 The sending and receiving functions of the method shown are executed by the processing module 1802. Figure 11 , Figure 14 ,or Figure 16 The method shown includes functions other than sending and receiving.

[0382] Optionally, the transceiver module 1801 may include a transmitting module ( Figure 18 (not shown in the image) and receiving module ( Figure 18 (Not shown in the diagram). The transmitting module is used to implement the transmitting function of the communication device 1800, and the receiving module is used to implement the receiving function of the communication device 1800.

[0383] Optionally, the communication device 1800 may also include a storage module. Figure 18(Not shown in the image), the storage module stores programs or instructions. When the processing module 1802 executes the program or instructions, the communication device 1800 can perform the above-described method. Figure 11 , Figure 14 ,or Figure 16 The method shown describes the functions of the terminal device or network device.

[0384] It is understood that the communication device 1800 may be a terminal device or a network device, or it may be a chip (system) or other component or assembly that can be disposed in a terminal device or a network device, or it may be a device that includes a terminal device or a network device. This application does not limit it in this regard.

[0385] In addition, the technical effects of the communication device 1800 can be referenced. Figure 11 , Figure 14 ,or Figure 16 The technical effects of the communication method shown will not be elaborated here.

[0386] Figure 19 Schematic diagram of the communication device provided in the embodiments of this application Figure 2 For example, the communication device can be a terminal device, or a chip (system) or other component or assembly that can be disposed in the terminal device. Figure 19 As shown, the communication device 1900 may include a processor 1901. Optionally, the communication device 1900 may also include a memory 1902 and / or a transceiver 1903. The processor 1901 is coupled to the memory 1902 and / or the transceiver 1903, for example, through a communication bus, an on-chip interface, or other communication lines. Optionally, the memory 1902 may be integrated with the processor 1901.

[0387] The following is combined with Figure 19 A detailed description of each component of the communication device 1900 is provided below:

[0388] The processor 1901 is the control center of the communication device 1900. It can be a single processor or a collective term for multiple processing elements. For example, the processor 1901 can be one or more central processing units (CPUs), application-specific integrated circuits (ASICs), or one or more integrated circuits configured to implement the embodiments of this application, such as one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs).

[0389] Optionally, the processor 1901 can perform various functions of the communication device 1900 by running or executing software programs stored in the memory 1902 and calling data stored in the memory 1902, such as performing the aforementioned functions. Figure 11 , Figure 14 ,or Figure 16 The communication method shown.

[0390] In a specific implementation, as one example, the processor 1901 may include one or more CPUs, for example... Figure 19 CPU0 and CPU1 are shown in the diagram.

[0391] In a specific implementation, as one example, the communication device 1900 may also include multiple processors, for example... Figure 19 The processors 1901 and 1904 are shown. Each of these processors can be a single-core processor or a multi-core processor. Here, "processor" can refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0392] The memory 1902 is used to store the software program that executes the solution of this application, and is controlled by the processor 1901 to execute it. The specific implementation method can be referred to the above method embodiment, and will not be repeated here.

[0393] Optionally, the memory 1902 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory 1902 may be integrated with the processor 1901 or may exist independently, and may be connected via the interface circuit of the communication device 1900. Figure 19 (Not shown in the image) is coupled to processor 1901, and this embodiment of the application does not specifically limit this.

[0394] Transceiver 1903 is used for communication with other communication devices. For example, if communication device 1900 is a terminal device, transceiver 1903 can be used to communicate with a network device or with another terminal device. As another example, if communication device 1900 is a network device, transceiver 1903 can be used to communicate with a terminal device or with another network device.

[0395] Alternatively, transceiver 1903 may include a receiver and a transmitter. Figure 19 (Not shown separately). The receiver is used to implement the receiving function, and the transmitter is used to implement the sending function.

[0396] Alternatively, the transceiver 1903 can be integrated with the processor 1901, or it can exist independently and be connected via the interface circuit of the communication device 1900. Figure 19 (Not shown in the image) is coupled to processor 1901, and this embodiment of the application does not specifically limit this.

[0397] Understandable, Figure 19 The structure of the communication device 1900 shown does not constitute a limitation on the communication device. Actual communication devices may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0398] Furthermore, the technical effects of the communication device 1900 can be referred to the technical effects of the method described in the above method embodiments, and will not be repeated here.

[0399] It should be understood that the processor in the embodiments of this application can be a central processing unit (CPU), or it can be other general-purpose processors, DSPs, ASICs, FPGAs, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0400] It should also be understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Non-volatile memory can be ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), EEPROM, or flash memory. Volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0401] The above embodiments can be implemented, in whole or in part, by software, hardware (such as circuits), firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0402] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0403] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0404] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0405] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0406] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0407] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0408] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0409] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0410] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes all the various possible memories described above.

Claims

1. A communication method, characterized in that, A chip applied to or in the first terminal, comprising: A first message is received, which is used to configure a transmission channel. The first message includes a first identifier and first information, which are used to identify a second terminal. The first information includes a second identifier, which is the identifier of the transmission channel or a radio bearer identifier. The first identifier is used to locally identify the second terminal, and the first terminal provides relay services to the second terminal. The second identifier of the second terminal is different from the second identifier of the third terminal, and the first identifier is the same as the identifier used to locally identify the third terminal. The second terminal provides relay services to the third terminal. Send a second message, which is a response to the first message.

2. The method according to claim 1, characterized in that, The identifier of the transmission channel is used to identify the Radio Link Control (RLC) channel of the link between the first terminal and the second terminal, or to identify the RLC channel of the link between the first terminal and the access network device.

3. The method according to claim 1 or 2, characterized in that, The radio bearer identifier of the second terminal is used to identify the radio bearer of the second terminal.

4. The method according to any one of claims 1 to 3, characterized in that, The second terminal is uniquely identified by the first terminal.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: Receive data; The data is transmitted to the second terminal based on the first information.

6. The method according to claim 5, characterized in that, If the second identifier is a radio bearer identifier, then the data, the first identifier, and the radio bearer identifier are carried in the first data unit; or, If the second identifier is the identifier of the transmission channel, then the first identifier and the data are carried in the first data unit, and the identifier of the transmission channel is carried in indication information independent of the first data unit.

7. A communication method, characterized in that, A chip used in an access network device or the access network device, comprising: A first message is sent to a first terminal, the first message being used to configure a transmission channel; the first message includes a first identifier and first information, the first identifier and the first information being used to identify a second terminal; wherein, the first information includes a second identifier, the second identifier being the identifier of the transmission channel or a radio bearer identifier; the first identifier is used to locally identify the second terminal, the first terminal providing relay services to the second terminal; the second identifier of the second terminal is different from the second identifier of the third terminal, the first identifier is the same as the identifier used to locally identify the third terminal, the second terminal providing relay services to the third terminal; Receive a second message, which is used in response to the first message.

8. The method according to claim 7, characterized in that, The identifier of the transmission channel is used to identify the RLC channel of the link between the first terminal and the second terminal, or to identify the RLC channel of the link between the first terminal and the access network device.

9. The method according to claim 7 or 8, characterized in that, The radio bearer identifier of the second terminal is used to identify the radio bearer of the second terminal.

10. The method according to any one of claims 7 to 9, characterized in that, The second terminal is uniquely identified by the first terminal.

11. A communication method, characterized in that, The first unit applied to the access network equipment includes: The device receives a first message from a second unit of the access network device. The first message is used to assign a first local identifier to a first terminal. The first local identifier is the same as a second local identifier of at least one terminal. The at least one terminal provides relay services to the first terminal. A second message is sent to the second unit, the second message being used to identify the first terminal.

12. The method according to claim 11, characterized in that, The second message is a Radio Resource Control (RRC) establishment request message for the first terminal.

13. The method according to claim 11 or 12, characterized in that, The first message includes a transmission channel identifier, which is used to identify the Radio Link Control (RLC) channel of the link between the first terminal and the second terminal, wherein the second terminal provides relay services to the first terminal; the transmission channel identifier of the first terminal is different from the transmission channel identifier of the at least one terminal.

14. The method according to claim 13, characterized in that, The second message includes the transmission channel identifier.

15. The method according to any one of claims 11 to 14, characterized in that, The first message also includes first indication information, which is used to indicate the correspondence between the first local identifier and the layer 2 identifier of the first terminal.

16. The method according to claim 15, characterized in that, The second message includes the first instruction information.

17. A communication method, characterized in that, The second unit applied to the access network equipment includes: A first message is sent to a first unit of the access network device. The first message is used to allocate a first local identifier to a first terminal. The first local identifier is the same as a second local identifier of at least one terminal. The at least one terminal provides relay services to the first terminal. A second message is received from the second unit, the second message being used to identify the first terminal.

18. The method according to claim 17, characterized in that, The second message is a Radio Resource Control (RRC) establishment request message for the first terminal.

19. The method according to claim 17 or 18, characterized in that, The first message includes a transmission channel identifier, which is used to identify the Radio Link Control (RLC) channel of the link between the first terminal and the second terminal, wherein the second terminal provides relay services to the first terminal; the transmission channel identifier of the first terminal is different from the transmission channel identifier of the at least one terminal.

20. The method according to claim 19, characterized in that, The second message includes the transmission channel identifier.

21. The method according to any one of claims 17 to 20, characterized in that, The first message further includes first indication information, which is used to indicate the correspondence between the first local identifier and the layer 2 identifier of the first terminal; the second message includes the first indication information.

22. A communication device, characterized in that, The apparatus includes: a module for performing the method as described in any one of claims 1-6, or a module for performing the method as described in any one of claims 7-10, or a module for performing the method as described in any one of claims 11-16, or a module for performing the method as described in any one of claims 17-21.

23. A communication device, characterized in that, The communication device includes a processing unit and a storage unit; the storage unit is used to store computer instructions, which, when executed by the processing unit, cause the method as described in any one of claims 1-6 to be executed, or cause the method as described in any one of claims 7-10 to be executed, or cause the method as described in any one of claims 11-16 to be executed, or cause the method as described in any one of claims 17-21 to be executed.

24. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a computer program or instructions that, when executed on a computer, cause the computer to perform the method as claimed in any one of claims 1-6, or the method as claimed in any one of claims 7-10, or the method as claimed in any one of claims 11-16, or the method as claimed in any one of claims 17-21.

25. A computer program product, characterized in that, The computer program product includes a computer program or instructions that, when executed on a computer, cause the method as described in any one of claims 1-6 to be performed, or the method as described in any one of claims 7-10 to be performed, or the method as described in any one of claims 11-16 to be performed, or the method as described in any one of claims 17-21 to be performed.

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