Wireless communication method and communication device

Abstract

Provided are a wireless communication method and a communication device. The wireless communication method comprises: a first terminal device receives a first identifier configured by a first device, the first identifier being used for transmitting data on a first link, wherein the first link is a sidelink, and the first link passes through a plurality of relay terminal devices.

Description

Wireless communication method and communication device Technical Field

[0001] The present application relates to the field of communication technology, and more particularly, to a wireless communication method and communication device. Background Art

[0002] Considering that two terminal devices may not be able to communicate with each other directly, some sideline communication systems have introduced terminal device to terminal device (or UE to UE, U2U) relay technology, that is, two terminal devices can be connected through a relay terminal device to transmit data through the relay terminal device.

[0003] U2U relay scenarios include multi-hop U2U relay scenarios, where data can be transmitted between two end devices through multiple relay devices. In multi-hop U2U relay scenarios, identifying the data flow of the U2U relay link is a problem that needs to be solved.

[0004] Summary of the Invention

[0005] The present application provides a wireless communication method and a communication device. The following introduces various aspects of the present application.

[0006] In a first aspect, a method for wireless communication is provided, comprising: a first terminal device receives a first identifier configured by a first device, the first identifier being used to transmit data on a first link; wherein the first link is a side link, and the first link passes through multiple relay terminal devices.

[0007] In a second aspect, a method for wireless communication is provided, including: a first device sends a first identifier configured by the first device to a first terminal device, wherein the first identifier is used to transmit data on a first link; wherein the first link is a side link, and the first link passes through multiple relay terminal devices.

[0008] According to a third aspect, a terminal device is provided, which is a first terminal device, and includes: a receiving module for receiving a first identifier configured by the first device, and the first identifier is used to transmit data on a first link; wherein the first link is a side link, and the first link passes through multiple relay terminal devices.

[0009] In a fourth aspect, a communication device is provided, which is a first device, and the communication device includes: a sending module for sending a first identifier configured by the first device to a first terminal device, and the first identifier is used to transmit data on a first link; wherein, the first link is a side link, and the first link passes through multiple relay terminal devices.

[0010] In a fifth aspect, a terminal device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the terminal device executes part or all of the steps in the method of the first aspect.

[0011] In the sixth aspect, a communication device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the communication device executes part or all of the steps in the method of the second aspect.

[0012] In a seventh aspect, an embodiment of the present application provides a communication system, which includes the above-mentioned terminal device and / or communication device. In another possible design, the system may also include other devices that interact with the terminal device or communication device in the solution provided in the embodiment of the present application.

[0013] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program enables a computer to execute part or all of the steps in the methods of the above aspects.

[0014] In a ninth aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a computer to perform some or all of the steps of the methods described in each of the above aspects. In some implementations, the computer program product may be a software installation package.

[0015] In the tenth aspect, an embodiment of the present application provides a chip, which includes a memory and a processor. The processor can call and run a computer program from the memory to implement some or all of the steps described in the methods of the above aspects.

[0016] In this embodiment of the present application, the first device can be configured with a first identifier so that nodes on the first link (multi-hop U2U relay link) can transmit data on the first link based on the first identifier. In other words, the first identifier configured by the first device can be used to identify the data flow of the U2U relay link, which helps to ensure normal data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a diagram illustrating an example of a system architecture of a wireless communication system to which an embodiment of the present application may be applied.

[0018] FIG2 is an example diagram of a network device allocating sideline communication resources to a terminal device.

[0019] FIG3 is an example diagram of a terminal device autonomously selecting side communication resources provided by an embodiment of the present application.

[0020] FIG4 is an example diagram of a terminal device autonomously selecting side communication resources provided by another embodiment of the present application.

[0021] FIG5 is a diagram showing an example of the architecture of a U2U relay.

[0022] FIG6 is a flow chart of a possible implementation of establishing an end-to-end PC5 connection between a source terminal device and a target terminal device.

[0023] FIG7 is a diagram illustrating an example of a layer 2 U2U relay architecture.

[0024] FIG8 is a flowchart of a wireless communication method provided in an embodiment of the present application.

[0025] FIG9 is a schematic flow chart of a wireless communication method provided in another embodiment of the present application.

[0026] FIG10 is a flow chart of a wireless communication method provided in yet another embodiment of the present application.

[0027] FIG11 is an example diagram of configuring a first identifier provided by an embodiment of the present application.

[0028] FIG12 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0029] FIG13 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0030] FIG14 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0031] FIG15 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0032] FIG16 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0033] FIG17 is an example diagram of sending assistance information provided by an embodiment of the present application.

[0034] FIG18 is an example diagram of sending assistance information provided by another embodiment of the present application.

[0035] FIG19 is an example diagram of sending assistance information provided by another embodiment of the present application.

[0036] FIG20 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0037] FIG21 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0038] FIG22 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0039] FIG23 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0040] FIG24 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0041] FIG25 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0042] FIG26 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0043] FIG27 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0044] FIG28 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0045] FIG29 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0046] FIG30 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0047] FIG31 is an example diagram of configuring the first identifier provided by another embodiment of the present application.

[0048] Figure 32 is a structural diagram of the terminal device provided in an embodiment of the present application.

[0049] Figure 33 is a structural diagram of the communication device provided in an embodiment of the present application.

[0050] Figure 34 is a structural diagram of the communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] Communication system architecture

[0052] FIG1 is a diagram illustrating an exemplary system architecture of a wireless communication system 100 to which embodiments of the present application may be applied. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographic area and may communicate with the terminal device 120 within the coverage area.

[0053] FIG1 exemplarily shows a network device and two terminal devices. Optionally, the wireless communication system 100 may include one or more network devices 110 and / or one or more terminal devices 120. For one network device 110, the one or more terminal devices 120 may all be located within the network coverage of the network device 110, or all be located outside the network coverage of the network device 110, or some may be located within the network coverage of the network device 110 and others outside the network coverage of the network device 110. This is not limited in the embodiments of the present application.

[0054] Optionally, the wireless communication system 100 may further include other network entities such as a network controller and a mobility management entity, which is not limited in the embodiment of the present application.

[0055] It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), etc. The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, satellite communication system, etc.

[0056] The terminal device in the embodiments of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiments of the present application may refer to a device that provides voice and / or data connectivity to a user and can be used to connect people, objects and machines, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. Optionally, the UE can be used to act as a base station. For example, the UE can act as a scheduling entity that provides sidelink signals between UEs in V2X or D2D, etc. For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and smart home devices communicate without relaying the communication signal through the base station.

[0057] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. A base station can broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmission point (TRP), transmission point (TP), master station MeNB, secondary station SeNB, multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. A base station can also refer to a communication module, a modem or a chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs base station functions in device-to-device D2D, vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. The base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form used by the network equipment.

[0058] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0059] In some deployments, the network device in the embodiments of the present application may refer to a CU or a DU, or the network device may include a CU and a DU. The gNB may also include an AAU.

[0060] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0061] It should be understood that all or part of the functions of the communication device in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (such as a cloud platform).

[0062] Sideline communication mode

[0063] Sidelink communication refers to a communication technology based on sidelink (SL). Sidelink communication can be, for example, D2D or V2X. In traditional cellular systems, communication data is received or sent between terminal devices and network devices, while sidelink communication supports direct transmission of communication data between terminal devices. Compared to traditional cellular communication, direct transmission of communication data between terminal devices can achieve higher spectrum efficiency and lower transmission latency. For example, the Internet of Vehicles system uses sidelink communication technology.

[0064] Certain standards or protocols (such as the 3rd Generation Partnership Project (3GPP)) define two modes (or transmission modes) of sideline communication: a first mode (or mode A, mode 3, etc.) and a second mode (or mode B, mode 4, etc.).

[0065] In the first mode, the resources of the terminal device (the resources mentioned in this application may also be referred to as transmission resources, such as time-frequency resources) are allocated by the network device. The terminal device can send data on the side link according to the resources allocated by the network device. The network device can allocate resources for a single transmission to the terminal device, or it can allocate resources for semi-static transmission to the terminal device. This first mode can be applied to scenarios covered by network devices, such as the scenario shown in Figure 2. In the scenario shown in Figure 2, the terminal device 120 is within the network coverage of the network device 110, so the network device 110 can allocate resources used in the side transmission process to the terminal device 120.

[0066] In the second mode, the terminal device can autonomously select one or more resources from a resource pool (RP). The terminal device can then perform side transmission based on the selected resources. For example, in the scenario shown in FIG3 , the terminal device 120 is located within the network coverage of the network device 110, and the terminal device 120 can also autonomously select one or more resources from the resource pool configured by the network device 110 for side transmission. For another example, in the scenario shown in FIG4 , the terminal device 120 is located outside the network coverage of the network device 110, and therefore, the terminal device 120 can autonomously select one or more resources from the pre-configured resource pool for side transmission.

[0067] Different research stages of side communication

[0068] In 3GPP, sideline communications can be divided into different research phases, and the research contents in different research phases vary.

[0069] In Release 12 (Rel-12) / Rel-13, sidelink communications (e.g., D2D) primarily focus on proximity-based service (ProSe) scenarios, for example, focusing on public safety services within proximity-based services. In ProSe services, the location of resource pools in the time domain can be configured to differentiate the transmission / reception of sidelink communication data between terminal devices. For example, resource pools can be configured to be discontinuous in the time domain, allowing terminal devices to discontinuously transmit / receive sidelink communication data on the sidelink, thereby achieving power savings.

[0070] In Rel-14 / 15, sidewalk communication is primarily studied for V2X scenarios, or more specifically, vehicle-to-vehicle communication scenarios. For example, research focuses on relatively high-speed vehicle-to-vehicle and vehicle-to-pedestrian communication services. In V2X, since the onboard system has a continuous power supply, power efficiency is not the primary issue. Instead, reducing data transmission latency is the primary concern. As an implementation method, in V2X, terminal devices can continuously transmit and receive sidewalk communication data to reduce data transmission latency.

[0071] In Rel-14, sideline communication also targets wearable device scenarios (further enhancements to device-to-device, FeD2D). For example, the focus is on scenarios where wearable devices access network devices through mobile phones. It should be understood that FeD2D is mainly aimed at low mobile speed and low-power access scenarios. During the FeD2D research process, in the pre-research stage, 3GPP determined that network equipment can configure the DRX (discontinuous reception) parameters of remote terminals through a relay terminal. However, because this topic did not enter the standardization stage, the specific details of how to configure DRX have not been determined.

[0072] NR has further enhanced the research on sidewalk communications based on LTE. For example, NR V2X has expanded the application scenarios of LTE V2X. NR V2X is no longer limited to broadcast scenarios, but has further expanded the application scenarios of V2X to unicast and multicast scenarios, so as to study the application of V2X in different application scenarios.

[0073] NR V2X can also define the two modes of side communication mentioned above. Furthermore, the terminal device can be in a mixed mode, that is, it can use the first mode to acquire resources and the second mode to acquire resources at the same time.

[0074] In addition to being applicable to scenarios where there is no feedback and the terminal device autonomously initiates hybrid automatic repeat request (HARQ) retransmission, NR V2X can also be applied to scenarios where HARQ retransmission is based on feedback, for example, in a unicast communication scenario, or in a multicast communication scenario.

[0075] Similar to LTE V2X, in NR V2X, since the on-board system has a continuous power supply, power efficiency is not the main issue to be solved in the V2X scenario. Instead, how to reduce the latency of data transmission is the main issue that needs to be solved in the V2X scenario. As an implementation method, in V2X, terminal devices can reduce the latency of data transmission by continuously sending / receiving side communication data.

[0076] Side-by-side U2U relay technology

[0077] Taking into account that two terminal devices may not be able to communicate with each other directly, some side communication systems have introduced U2U relay technology (or, U2U relay function). For example, in Rel-17 ProSe, 3GPP studied U2U relay technology based on layer 2 or layer 3 relay. Figure 5 shows an example diagram of the architecture of a U2U relay. As shown in Figure 5, the source terminal device is connected to the target terminal device through a relay terminal device, and the relay terminal device can transfer data between the source terminal device and the target terminal device. In some embodiments, the source terminal device and the target terminal device in the U2U relay architecture can also be referred to as end terminal devices (or remote terminal devices), that is, in the U2U relay scenario, the two end terminal devices can be connected through the relay terminal device to transmit data through the relay terminal device.

[0078] As a possible implementation, the source terminal device and the target terminal device (i.e., the two end terminal devices) can each establish a connection with the relay terminal device to establish an end-to-end PC5 connection through the relay terminal device. The following describes a possible implementation of establishing an end-to-end PC5 connection between the source terminal device and the target terminal device in conjunction with FIG6 .

[0079] As shown in FIG6 , the method for establishing an end-to-end PC5 connection between a source terminal device and a target terminal device may include steps 1 to 5.

[0080] In step 1, the relay terminal device registers the specified terminal device relay capability and configures relay policy parameters.

[0081] In step 2, the source terminal device, the relay terminal device, and the target terminal device discover each other.

[0082] As a possible implementation manner, the source terminal device, the relay terminal device, and the target terminal device may discover each other through a discovery message or a direct communication request (DCR) message.

[0083] In some embodiments, the relay terminal device may help the source terminal device forward the discovery message or the DCR message.

[0084] In step 3, the source terminal device and the target terminal device perform relay selection.

[0085] In some embodiments, the source terminal device and the target terminal device may perform relay selection after discovering each other, so as to select an appropriate relay to establish a connection with each other.

[0086] In step 4, the source terminal device and the target terminal device respectively establish connections with the relay terminal device.

[0087] In some embodiments, the connections established by the source terminal device and the target terminal device with the relay terminal device are single-hop connections, that is, the source terminal device and the target terminal device can establish single-hop connections with the relay terminal device.

[0088] In step 5, the source terminal device and the target terminal device establish an end-to-end connection through the relay terminal device.

[0089] As mentioned earlier, 3GPP is researching U2U relay technology based on Layer 2 or Layer 3 relay. The following introduces U2U relay technology based on Layer 2.

[0090] Figure 7 illustrates the Layer 2 U2U relay architecture. As shown in Figure 7, the adaptation layer (ADAPT) is placed above the control plane and user plane radio link control (RLC) sublayers between the relay terminal device and the source / destination terminal device. The PC5-service data adaptation protocol (SDAP) / PC5-packet data convergence protocol (PDCP) and radio resource control (RRC) layers terminate between the source and destination terminal devices, while the RLC, medium access control (MAC), and physical layer (PHY) terminate in each link (i.e., the link between the source and relay terminal devices and the link between the relay and destination terminal devices).

[0091] In some embodiments, the adaptation layer may also be referred to as a sidelink relay adaptation protocol (SRAP) layer.

[0092] For layer 2 U2U relay, in some embodiments, the adaptation layer of the relay terminal device supports side bearer mapping between access PC5-RLC channels.

[0093] For sidelink relay services, different end-to-end bearers on the same end terminal device and / or different end terminal devices can be mapped N:1 and data multiplexed on a single PC5-RLC channel. In some embodiments, the end-to-end bearers can include signaling radio bearers (SRBs) and / or data radio bearers (DRBs).

[0094] In some embodiments, the adaptation layer can support terminal identification for side traffic (multiplexing data from multiple terminal devices), or in other words, the adaptation layer can allocate terminal identification for side traffic. The PC5 radio bearer and terminal identification of the terminal device can be included in the adaptation layer so that the destination terminal device can associate received data packets with a specific PDCP entity associated with the radio bearer of the source terminal device.

[0095] Sideline U2U relay scenarios can include single-hop U2U relay scenarios and multi-hop U2U relay scenarios. In a single-hop U2U relay scenario, two end-terminal devices can be connected through a single relay terminal device, or in other words, two end-terminal devices can transmit data through a single relay terminal device. In a multi-hop U2U relay scenario, two end-terminal devices can be connected through multiple (two or more) relay terminal devices, or in other words, two end-terminal devices can transmit data through multiple relay terminal devices.

[0096] As a possible implementation, in a single-hop U2U relay scenario, the adaptation layer can identify data streams using ID information and bearer ID information. For example, the relay terminal device can assign a terminal device identifier (UE ID) to the end terminal device to identify the data stream using the UE ID.

[0097] However, in multi-hop U2U relay scenarios, the presence of multiple relay terminal devices complicates the topology between communication devices, making identification conflicts more likely to occur, leading to data flow identification issues. Therefore, in multi-hop U2U relay scenarios, identifying data flows within U2U relay links is a challenge that needs to be addressed.

[0098] In addition, since there are more nodes in the multi-hop U2U relay scenario, who configures the identifier also needs further discussion.

[0099] To address the above issues, embodiments of the present application provide a wireless communication method and communication device, which configures a first identifier on a first device to ensure that nodes on a first link can transmit data normally on the first link. The following describes an embodiment of the method of the present application in conjunction with the accompanying drawings.

[0100] FIG8 is a flow chart of a wireless communication method according to an embodiment of the present application. The method shown in FIG8 may include step S810, which is described below.

[0101] In step S810, the first terminal device receives a first identifier configured by the first device.

[0102] In some embodiments, the first identifier may be sent directly from the first device to the first terminal device. In other words, after the first device is configured with the first identifier, the first identifier may be sent directly to the first terminal device.

[0103] In some embodiments, the first identifier can be sent by the first device to the first terminal device via other terminal devices (e.g., other terminal devices on the first link). In other words, after the first device is configured with the first identifier, the first identifier can be forwarded to the first terminal device via other terminal devices. As an example, the first identifier can be sent by the first device to the first terminal device via a second terminal device, where the second terminal device is associated with the first terminal device via a single-hop link.

[0104] In an embodiment of the present application, the first identifier can be used to transmit data on a first link, where the first link is a sidelink and passes through multiple relay terminal devices. In other words, the first identifier can be used to transmit data on a multi-hop U2U relay link. In other words, the first identifier can be used to identify a data flow on a multi-hop U2U relay link.

[0105] In an embodiment of the present application, the first identifier may be associated with the first link. For example, the first identifier may be used to identify some or all single-hop links on the first link. Alternatively, the first identifier may be used to identify a node on the first link.

[0106] In some embodiments, the first identifier mentioned in the embodiments of the present application may be an identifier. The identifier may independently identify a link (such as a first link) so as to transmit data on the link. Alternatively, the identifier may jointly identify a link with other identifiers (such as a second identifier, etc.) so as to transmit data on the link. Alternatively, the identifier may jointly identify nodes on a link with other identifiers so as to identify a link through these nodes, thereby transmitting data on the link.

[0107] The embodiments of the present application do not limit the implementation method of how to use the first identifier to transmit data on the first link. As one possible implementation method, the first identifier can be used to identify a link, such as identifying the first link or a portion of the link on the first link. In this way, the first link can be identified based on the first identifier, thereby completing data transmission on the first link. As another possible implementation method, the first identifier can be used to identify a node on the first link. In this way, the node on the first link can be identified based on the first identifier, thereby completing data transmission on the first link.

[0108] In some embodiments, the first identifier may be used to identify one of the following: the first link; a single-hop link on the first link; multiple single-hop links on the first link; or a terminal device on the first link. This is exemplified below.

[0109] Case 1: The first identifier is used to identify the first link

[0110] In this case, it can be understood that the first identifier can be used to identify a complete link. In other words, the first link can be identified by an identifier.

[0111] In some embodiments, if the first identifier is used to identify the first link, it can be considered that the identifiers corresponding to the single-hop links on the first link are the same, that is, the single-hop links on the first link are all identified by the first identifier.

[0112] In some embodiments, when the first identifier is used to identify the first link, the first identifier can be carried in the SRAP packet as an identification identifier of the first link. In this way, when a terminal device on the first link receives the SRAP packet, it can know which link the packet belongs to (e.g., the first link) and thus know how to process the packet.

[0113] In case 1, the first identifier may be configured by the first device. For an introduction to the first device and how the first device configures the first identifier, please refer to the relevant introduction below. For the sake of brevity, it is not described in detail here.

[0114] In some embodiments, after configuring the first identifier, the first device may send the first identifier to each terminal device (each node) on the first link, wherein the first identifier sent by the first device to each terminal device is the same.

[0115] As an implementation manner, the first device may directly send the first identifier to each terminal device on the first link.

[0116] As another implementation method, the first device can send the first identifier to a terminal device on the first link that is directly connected to the first device or served by the first device. Thereafter, the terminal device that receives the first identifier sends it in turn to the next terminal device that is directly connected to the terminal device that received the first identifier.

[0117] Case 2: The first identifier is used to identify a single-hop link on the first link

[0118] That is, the first link can be identified by multiple identifiers (the first identifier and the other identifiers). In this case, it can be considered that the identifiers corresponding to the individual single-hop links on the first link are different, that is, the individual single-hop links on the first link are identified by different identifiers.

[0119] The embodiment of the present application does not limit the single-hop link identified by the first identifier. The first identifier can be used to identify any single-hop link on the first link (such as the first single-hop link), and other single-hop links can be identified by other identifiers, and the identifier corresponding to each single-hop link is different.

[0120] For example, if the first identifier is used to identify the first single-hop link on the first link, the first identifier, as an identification identifier of the first single-hop link, can be carried in the SRAP packet. In this way, when a terminal device on the first link receives the SRAP packet, it can know which hop the packet originated from, which hop it should be destined for, and / or how to process the packet.

[0121] In some embodiments, the identifiers of the single-hop links corresponding to the first link may be configured by the same device (eg, the first device).

[0122] In some embodiments, the identifiers of some or all of the single-hop links corresponding to the first link may be configured by different devices. For example, the identifiers of the single-hop links corresponding to the first link may all be configured by different devices. Alternatively, the identifiers of two adjacent single-hop links corresponding to the first link may be configured by different devices.

[0123] In some embodiments, an identifier corresponding to a single-hop link on the first link can be configured by a terminal device associated with the single-hop link. In other words, a single-hop link on the first link is associated with two terminal devices, and the identifier corresponding to the single-hop link can be configured by one of the two terminal devices. Taking the example of a first identifier used to identify the first single-hop link, the first single-hop link is associated with a first terminal device and a second terminal device, and the first identifier can be configured by the second terminal device (wherein the first terminal device is the terminal device that receives the first identifier).

[0124] In some embodiments, a terminal device on the first link may be configured with only an identifier corresponding to a single-hop link.

[0125] In some embodiments, a terminal device on the first link may be configured with identifiers corresponding to multiple single-hop links, for example, identifiers corresponding to two single-hop links associated with the terminal device.

[0126] In some embodiments, an identifier corresponding to a single-hop link on the first link may be configured by an end terminal device.

[0127] In some embodiments, the identifier corresponding to a single-hop link on the first link may be configured by the relay terminal device.

[0128] In some embodiments, both the end terminal device and the relay terminal device on the first link participate in the configuration of the identifier on the first link.

[0129] Taking the example of the first link including N single-hop links, each of the N single-hop links can correspond to an identifier, and the identifier corresponding to each single-hop link can be configured by a terminal device associated with each single-hop link, where N is a positive integer greater than or equal to 2.

[0130] As an example, the identifier corresponding to each single-hop link in the N single-hop links can be configured by the terminal device at the starting end of the single-hop link. Taking the two terminal devices associated with the first single-hop link as the source terminal device (the terminal device at the starting end) and the relay terminal device 1 (the terminal device at the ending end) as an example, the identifier of the first single-hop link can be configured by the source terminal device. Taking the two terminal devices associated with the first single-hop link as the relay terminal device 1 (the terminal device at the starting end) and the relay terminal device 2 (the terminal device at the ending end) as an example, the identifier of the first single-hop link can be configured by the relay terminal device 1.

[0131] As another example, the identifier corresponding to each of the N single-hop links can be configured by the terminal device at the end of the single-hop link. Taking the two terminal devices associated with the first single-hop link as the source terminal device (the terminal device at the starting end) and the relay terminal device 1 (the terminal device at the end end) as an example, the identifier of the first single-hop link can be configured by the relay terminal device 1. Taking the two terminal devices associated with the first single-hop link as the relay terminal device 1 (the terminal device at the starting end) and the relay terminal device 2 (the terminal device at the end end) as an example, the identifier of the first single-hop link can be configured by the relay terminal device 2.

[0132] In some embodiments, a terminal device on the first link can only be configured with an identifier of a single-hop link.

[0133] In some embodiments, the relay terminal device on the first link participates in the configuration of the identifier on the first link. For example, the relay device on the first link participates in the configuration of the identifier on the first link, while the end terminal device does not participate in the configuration of the identifier on the first link.

[0134] In some embodiments, a relay terminal device on the first link can be configured with identifiers of two or more single-hop links.

[0135] Taking the example of the first link including M relay terminal devices, each of the M relay terminal devices is associated with two single-hop links on the first link, and each relay terminal device can configure identifiers for the two single-hop links associated with each relay terminal device, where M is a positive integer greater than or equal to 2.

[0136] In some embodiments, if a relay terminal device configures identifiers for two single-hop links associated with the relay terminal device, a single-hop link may be configured with two identifiers (such as the two relay terminal devices associated with the single-hop link are both configured with the single-hop link identifier), resulting in an identifier conflict.

[0137] In response to the above problems, the embodiments of the present application provide several solutions. Below, taking the example of a first single-hop link located between a first relay terminal device and a second relay terminal device on the first link, and the first single-hop link may be configured with two identifiers, these solutions are introduced exemplarily.

[0138] Solution 1: Assuming that the first single-hop link is configured with two identifiers, the two identifiers may be associated with different transmission directions.

[0139] Assuming that the first relay terminal device configures a second identifier for the first single-hop link and the second relay terminal device configures a third identifier for the first single-hop link, the second identifier can be associated with the first transmission direction of the first single-hop link, and the third identifier can be associated with the second transmission direction of the first single-hop link.

[0140] Solution 2: Assuming that the first single-hop link is configured with two identifiers, different relay terminal devices can use different identifiers for data transmission.

[0141] Assume that the first relay terminal device configures the second identifier for the first single-hop link, and the second relay terminal device configures the third identifier for the first single-hop link. The first relay terminal device can identify the first single-hop link or perform data transmission based on the mapping relationship between the second identifier and the third identifier, and the second identifier. In other words, for the first terminal device, the first single-hop link can perform data transmission based on the mapping relationship between the second identifier and the third identifier, and the second identifier. The second relay terminal device can identify the first single-hop link or perform data transmission based on the mapping relationship between the second identifier and the third identifier, and the third identifier. In other words, for the second terminal device, the first single-hop link can perform data transmission based on the mapping relationship between the second identifier and the third identifier, and the third identifier.

[0142] Solution 3: Assuming that both the first relay terminal device and the second relay terminal device can be the first single-hop link configuration identifier, it can be determined that one of the relay terminal devices is the first single-hop link configuration identifier.

[0143] In other words, assuming that both the first relay terminal device and the second relay terminal device can be configured as the first single-hop link identifier, it can be determined that the first relay terminal device is configured as the first single-hop link identifier, while the second relay terminal device will not be configured as the first single-hop link identifier.

[0144] In some embodiments, the relay terminal device that is identified for the first single-hop link configuration can be determined based on one or more of the following: the time of sending the identification of the first single-hop link, the time of sending the assistance information, the terminal device capabilities of the relay terminal device, the information coordinated by the relay terminal device, relevant information on establishing the connection with the first single-hop link, etc.

[0145] Taking the relay terminal device that is determined as the first single-hop link configuration identifier based on the time of sending the first single-hop link identifier as an example, the relay terminal device that is determined as the first single-hop link configuration identifier can be a relay terminal device that sends the first single-hop link identifier earlier, or it can be a relay terminal device that sends the first single-hop link identifier later.

[0146] Taking the relay terminal device identified as the first single-hop link configuration according to the time of sending the assistance information as an example, the relay terminal device identified as the first single-hop link configuration can be a relay terminal device that sends the assistance information earlier, or a relay terminal device that sends the assistance information later.

[0147] Taking the relay terminal device identified as the first single-hop link configuration according to the terminal device capability of the relay terminal device as an example, the relay terminal device identified as the first single-hop link configuration can be a relay terminal device with stronger terminal device capability or a relay terminal device with weaker terminal device capability.

[0148] Taking the relay terminal device determined as the first single-hop link configuration identifier based on the relevant information of the connection establishment with the first single-hop link as an example, the relay terminal device identified as the first single-hop link configuration identifier can be the relay terminal device that initiates the connection establishment request for the first single-hop link, or it can be the relay terminal device that receives the connection establishment request for the first single-hop link.

[0149] In some embodiments, the assistance information may be used to determine an identifier corresponding to the first single-hop link.

[0150] Taking the first relay terminal device as an example of configuring an identifier for the first single-hop link, the first relay terminal device may meet one or more of the following conditions: the time when the first relay terminal device sends the identifier of the first single-hop link is earlier than the time when the second relay terminal device sends the identifier of the first single-hop link; the time when the first relay terminal device sends assistance information is earlier than the time when the second relay terminal device sends assistance information; the terminal device capability of the first relay terminal device is higher than the terminal device capability of the second relay terminal device; the first relay terminal device and the second relay terminal device negotiate to determine that the identifier of the first single-hop link is configured by the first relay terminal device; the connection establishment request for establishing the first single-hop link is initiated by the first relay terminal device.

[0151] Solution 4: Assuming that the first single-hop link is configured with two identifiers, the relay terminal device can perform data transmission based on the target identifier of the two identifiers.

[0152] Assuming that the first relay terminal device configures a second identifier for the first single-hop link and the second relay terminal device configures a third identifier for the first single-hop link, the first single-hop link can transmit data based on a target identifier among the second identifier and the third identifier.

[0153] The embodiment of the present application does not limit the method for determining the target identifier. In some embodiments, the target identifier can be determined by negotiation between the first relay terminal device and the second relay terminal device. In some embodiments, the target identifier can be determined based on certain conditions or information, for example, the target identifier can be determined based on the value of the identifier.

[0154] Taking determining the target identifier based on the value of the identifier as an example, in some embodiments, the target identifier can be the identifier with the smaller value between the second identifier and the third identifier; in some embodiments, the target identifier can be the identifier with the larger value between the second identifier and the third identifier.

[0155] Case 3: The first identifier is used to identify multiple single-hop links on the first link

[0156] In other words, the first link can be identified by one or more identifiers (the first identifier and other identifiers). In this case, it can be considered that the identifiers corresponding to some single-hop links on the first link may be the same, while the identifiers corresponding to other single-hop links may be different. In other words, different single-hop links on the first link can be identified by the same identifier or by different identifiers.

[0157] The embodiments of the present application do not limit the multiple single-hop links identified by the first identifier, and the first identifier can be any multiple single-hop links on the first link. As a possible implementation, the first identifier can be used to identify two single-hop links on the first link. As another possible implementation, the first identifier can be used to identify three or more single-hop links on the first link.

[0158] In some embodiments, when the first identifier is used to identify two single-hop links on the first link, the two single-hop links may be two adjacent single-hop links, or the two single-hop links may be two single-hop links associated with the same terminal device (such as a relay terminal device). However, the embodiments of the present application are not limited thereto, and the two single-hop links may be any two single-hop links on the first link.

[0159] In some embodiments, if the first identifier is used to identify two single-hop links associated with the same relay terminal device, the first identifier may be configured by the relay terminal device associated with the two single-hop links. Taking the example of a first identifier being used to identify two single-hop links associated with a first relay terminal device, the first identifier may be configured by the first relay terminal device. However, the embodiments of the present application are not limited to this. For example, the first identifier may also be configured by a relay terminal device that is not associated with the two single-hop links.

[0160] In some embodiments, when the first identifier is used to identify three or more single-hop links on the first link, the three or more single-hop links may be adjacent single-hop links. However, the embodiments of the present application are not limited thereto, and the three or more single-hop links may be any three or more single-hop links on the first link.

[0161] In some embodiments, the first identifier is used to identify multiple single-hop links on the first link, which can also be understood or replaced by the first identifier is used to identify a link segment on the first link, and the link segment can include multiple single-hop links.

[0162] Case 4: The first identifier is used to identify a terminal device on the first link

[0163] That is, the first link can be identified by multiple identifiers, each of which is used to identify a terminal device on the first link. In this case, it can be considered that the identifiers corresponding to the terminal devices on the first link are different.

[0164] In some embodiments, if the first identifier is used to identify a terminal device on the first link, the first identifier may include a terminal device identifier (UE ID) of the terminal device. However, the embodiment of the present application is not limited thereto, and the first identifier may also identify a terminal device on the first link in other ways.

[0165] In some embodiments, the first identifier may include a terminal device identifier of an end terminal device on the first link, so as to identify the end terminal device through the first identifier.

[0166] In some embodiments, the first identifier may include a terminal device identifier of a relay terminal device on the first link, so as to identify the relay terminal device through the first identifier.

[0167] In some embodiments, the first link may be determined based on terminal device identifiers of multiple terminal devices. For example, the first link may be determined based on terminal device identifiers of two end terminal devices on the first link. Alternatively, the first link may be determined based on terminal device identifiers of each terminal device on the first link, etc.

[0168] As an example, the first identifier may include a terminal device identifier of an end terminal device on the first link, and the first link may be determined by the terminal device identifiers of two end terminal devices on the first link.

[0169] As another example, the first identifier may include a terminal device identifier of a terminal device (such as a relay terminal device or an end terminal device) on the first link, and the first link may be determined by the terminal device identifiers of each terminal device on the first link.

[0170] In some embodiments, for different U2U relay links (such as the first link and other U2U relay links), the terminal device identifier (such as the first identifier) ​​corresponding to the same terminal device entity may be different. In other words, for the same terminal device, its corresponding terminal device identifier in different U2U relay links may be different. Taking the first link including UE1, UE2 and UE3, and the second link including UE1, UE4 and UE5 as an example, the terminal device identifier corresponding to UE1 in the first link (such as AA123) is different from the terminal device identifier corresponding to UE1 in the second link (such as BB123).

[0171] In this way, the embodiment of the present application can identify a link or a data stream based on the terminal device identifiers of the two end terminal devices. For example, the first link includes the end terminal device UE1, the relay terminal device UE2, the relay terminal device UE3 and the end terminal device UE4, wherein the terminal device identifier of UE1 in the first link is AA123, and the terminal device identifier of UE4 in the first link is AA456; the second link includes the end terminal device UE1, the relay terminal device UE5, the relay terminal device UE6 and the end terminal device UE4, wherein the terminal device identifier of UE1 in the second link is BB123, and the terminal device identifier of UE4 in the second link is BB456. Then, the terminal device identifier AA123 and the terminal device identifier AA456 can be used to identify or determine the first link, and the terminal device identifier BB123 and the terminal device identifier BB456 can be used to identify or determine the second link.

[0172] In this embodiment of the present application, the first device can be configured with a first identifier so that nodes on the first link (multi-hop U2U relay link) can transmit data on the first link based on the first identifier. In other words, the first identifier configured by the first device can be used to identify the data flow of the U2U relay link, which helps to ensure normal data transmission.

[0173] The following introduces the first device and the method of configuring the first identifier.

[0174] In some embodiments, the first link is identified by using an identifier, for example, the first identifier is used to identify the first link. In this case, the identifier can be configured by a device.

[0175] In some embodiments, the first link is identified using multiple identifiers, for example, the first identifier is used to identify a single-hop link or multiple single-hop links of the first link, or the first identifier is used to identify a terminal device on the first link. In this case, the multiple identifiers can be configured by one device or by multiple devices.

[0176] In some embodiments, the manner in which all identifiers corresponding to the first link are configured by one device can be understood as central node configuration. For example, the central node can configure one identifier to determine the first link. Alternatively, the central node can configure multiple identifiers to determine the first link. Taking the example of all identifiers corresponding to the first link being configured by the first device, the first device can configure one identifier to determine the first link (e.g., the one identifier is used to identify a link), and the first device can also configure multiple identifiers to determine the first link (e.g., each of the multiple identifiers is used to identify a single-hop link, multiple single-hop links, a terminal device, etc. on a link).

[0177] In some embodiments, the manner in which all identifiers corresponding to the first link are configured by multiple devices can be understood as distributed node configuration. For example, each of the multiple devices can respectively configure identifiers corresponding to some single-hop links on the first link. Alternatively, each of the multiple devices can respectively configure identifiers corresponding to some terminal devices on the first link, etc. Taking the example of all identifiers corresponding to the first link being configured by the first device and the second device, the first device and the second device can respectively configure one or more identifiers to determine the first link (for example, each of the one or more identifiers can be used to identify a single-hop link, multiple single-hop links, a terminal device, etc. on a link).

[0178] As mentioned above, the first identifier is configured by the first device. This embodiment of the application does not limit the first device, as long as the first device can be configured with the first identifier. For example, the first device can be a terminal device on the first link. Alternatively, the first device can be an external device of the first link.

[0179] In some embodiments, when the first device is a terminal device on the first link, the first device may be an end terminal device on the first link, for example, the first device may be a source terminal device and / or a target terminal device on the first link.

[0180] In some embodiments, when the first device is a terminal device on the first link, the first device may be a relay terminal device on the first link. For example, the first device may be a target relay terminal device on the first link.

[0181] In some embodiments, the target relay terminal device may be any relay terminal device on the first link that can be configured with the first identifier.

[0182] In some embodiments, the target relay terminal device may be determined based on certain conditions or information. For example, the target relay terminal device may be determined based on one or more of the following: the distance between the relay terminal device and the end terminal device on the first link; first indication information sent by an upper layer; terminal device capabilities of the relay terminal device on the first link; whether the relay terminal device on the first link is within the coverage of the network device; or the location of the relay terminal device on the first link within the first link.

[0183] The embodiments of the present application do not limit the implementation method for determining the distance between the relay terminal device and the end terminal device on the first link. As a possible implementation method, the distance between the relay terminal device and the end terminal device can be indicated by the number of relay hops between the relay terminal device and the end terminal device. In other words, the target relay terminal device can be determined based on the number of relay hops between the relay terminal device and the end terminal device on the first link. However, the embodiments of the present application are not limited to this. For example, the distance between the relay terminal device and the end terminal device can also be indicated by the distance between the terminal device entities (for example, how many meters apart).

[0184] In some embodiments, the upper layer may be an upper layer of RRC or an upper layer of the adaptation layer. That is, the RRC layer or the adaptation layer may determine the target relay terminal device based on the first indication information sent by the upper layer of RRC or the upper layer of the adaptation layer. As an example, the upper layers of each node on the first link may negotiate the target relay terminal device and indicate the negotiated target relay terminal device to the RRC layer or the adaptation layer.

[0185] In some embodiments, the upper layer may refer to an upper layer of each node on the first link. For example, the upper layer of each node may send the first indication information to its own RRC layer or adaptation layer.

[0186] In some embodiments, the upper layer may refer to the upper layer of the target relay terminal device. For example, after the upper layers of each node have negotiated the target relay terminal device, the upper layer of the target relay terminal device may send the first indication information to its own RRC layer or adaptation layer.

[0187] In some embodiments, the upper layer may include one or more of the following: application layer, ProSe layer, V2X layer, etc.

[0188] Exemplarily, the above-mentioned target relay terminal device can be one or more of the following: the relay terminal device closest to the end terminal device on the first link, the relay terminal device indicated by the first indication information sent by the upper layer, the relay terminal device determined according to the terminal device capabilities, the relay terminal device on the first link within the network coverage, and the relay terminal device at the center of the first link.

[0189] In some embodiments, the relay terminal device closest to the end terminal device on the first link may be the relay terminal device with the least relay hops from the end terminal device. In other words, the target relay terminal device may be the relay terminal device with the least relay hops from the end terminal device.

[0190] In some embodiments, the relay terminal device closest to the end terminal device on the first link may be the relay terminal device closest to the source terminal device. In other words, the target relay terminal device may be the relay terminal device closest to the source terminal device.

[0191] In some embodiments, the relay terminal device closest to the end terminal device on the first link may refer to the relay terminal device closest to the target terminal device. In other words, the target relay terminal device may be the relay terminal device closest to the target terminal device.

[0192] In some embodiments, the aforementioned end terminal devices (such as source terminal devices or target terminal devices) may be protocol-predefined, preconfigured, or network-configured, and the embodiments of the present application do not limit this. For example, the protocol may specify that the relay terminal device closest to the end terminal device is the relay terminal device closest to the source terminal device. Alternatively, the network may configure the relay terminal device closest to the end terminal device to be the relay terminal device closest to the target terminal device, etc.

[0193] In some embodiments, determining the relay terminal device based on the terminal device capabilities may mean determining the relay terminal device with the strongest terminal device capabilities on the first link as the target relay terminal device, or in other words, the target relay terminal device may be the relay terminal device with the strongest terminal device capabilities on the first link. However, the embodiments of the present application are not limited thereto, and in some embodiments, the relay terminal device with the weakest or intermediate capabilities on the first link may also be determined as the target relay terminal device.

[0194] In some embodiments, the target relay terminal device may be a relay terminal device on the first link that is within the network coverage. However, the present application is not limited thereto. In some embodiments, the target relay terminal device may also be a relay terminal device on the first link that is outside the network coverage.

[0195] In some embodiments, the target relay terminal device may be a relay terminal device at the center of the first link. However, the present application is not limited thereto. In some embodiments, the target relay terminal device may also be a relay terminal device at another location on the first link.

[0196] In some embodiments, the target relay terminal device may be determined according to one of the above methods. For example, the target relay terminal device may be the relay terminal device closest to the end terminal device on the first link. Alternatively, the target relay terminal device may be the relay terminal device indicated by indication information sent by an upper layer. Alternatively, the target relay terminal device may be the relay terminal device at the center of the first link.

[0197] In some embodiments, the target relay terminal device can be determined based on multiple methods described above. For example, the target relay terminal device is the relay terminal device on the first link that is closest to the end terminal device and is within the network coverage area. Alternatively, the target relay terminal device is a relay terminal device at the center of the first link with relatively strong terminal device capabilities. Alternatively, the target relay terminal device is a relay terminal device at the center of the first link and within the network coverage area, etc.

[0198] In some embodiments, the target relay terminal device determined according to one of the above methods may include multiple devices. For example, there are multiple (such as two or more) relay terminal devices that are at the same distance (such as the number of relay hops) from the end terminal device (such as the source terminal device). Or, the terminal device capabilities of the multiple relay terminal devices on the first link are the same or similar. Alternatively, there are multiple relay terminal devices on the first link that are within the coverage of the network device. Alternatively, there are multiple relay terminal devices at the center of the first link, etc. In response to the above problem, as a possible implementation method, the target relay terminal device can be arbitrarily selected from multiple relay terminal devices that meet the conditions. As another possible implementation method, the target relay terminal device can be determined based on multiple methods described above, or in other words, when the relay terminal device determined according to one of the above methods includes multiple devices, more conditions or information can be considered to jointly determine the target relay terminal device. For example, if there are multiple relay terminal devices that are at the same distance from the end terminal device, then the relay terminal device within the network coverage range among the multiple relay terminal devices can be considered as the target relay terminal device. Alternatively, if there are multiple relay terminal devices with the same terminal device capabilities, the relay terminal device at the center of the first link among the multiple relay terminal devices may be determined as the target relay terminal device.

[0199] In some embodiments, when the first device is an external device of the first link, the first device may be a serving terminal device (serving UE or service UE) of the terminal device on the first link, or the first device may be a network device, which is not limited in the embodiments of the present application.

[0200] The embodiment of the present application does not limit the service terminal device of the terminal device on the first link. For example, the service terminal device can be a service terminal device of an end terminal device (such as a source terminal device or a target terminal device). Alternatively, the service terminal device can be a service terminal device of a relay terminal device.

[0201] The embodiment of the present application does not limit the carrying method of the first identifier. For example, taking the first identifier being carried by a first message as an example, the first message can be a message for sidelink transmission or a message for downlink transmission.

[0202] In some embodiments, if the first identifier is configured by a terminal device on the first link, the first message carrying the first identifier may be a message for sideline transmission. For example, if the first identifier is configured by an end terminal device on the first link, the first message may be a message for sideline transmission. Alternatively, if the first identifier is configured by a relay terminal device on the first link, the first message may be a message for sideline transmission.

[0203] In some embodiments, if the first identifier is configured by the serving terminal device of a terminal device on the first link, the first message carrying the first identifier may be a message for sideline transmission. For example, if the first identifier is configured by the serving terminal device of an end terminal device on the first link, the first message may be a message for sideline transmission. Alternatively, if the first identifier is configured by the serving terminal device of a relay terminal device on the first link, the first message may be a message for sideline transmission.

[0204] In some embodiments, if the first message is a message for sideline transmission, the first message may be one or more of the following: PC5-RRC message, PC5-S message.

[0205] In some embodiments, the first message may include configuration information of the SRAP layer, and the configuration information may include the first identifier. For example, if the first message is a PC5-RRC message, the first message may include configuration information of the SRAP layer, and the configuration information may include the first identifier.

[0206] In some embodiments, if the first identifier is configured by the network device, the first message carrying the first identifier may be a message for downlink transmission.

[0207] In some embodiments, if the first message is a message for downlink transmission, the first message may be one or more of the following: RRC message, MAC CE, DCI, etc.

[0208] In some embodiments, the first identifier does not distinguish between data transmission directions. That is, the same single-hop link may correspond to one identifier, and the identifier can be used in both data transmission directions corresponding to the single-hop link.

[0209] In some embodiments, the first identifier distinguishes the direction of data transmission. That is, the same single-hop link can correspond to two identifiers, and the two identifiers correspond to the two data transmission directions corresponding to the single-hop link (or the two identifiers are used for different data transmission directions). That is, each of the two identifiers is only used in one of the two data transmission directions corresponding to the single-hop link. In other words, for the same single-hop link, identifiers for different data transmission directions can be configured separately.

[0210] In some embodiments, before the first terminal device receives the first identifier, the first terminal device may transmit data based on other identifiers to ensure normal transmission of the data stream of the first link. This will be described in detail below with reference to FIG9 .

[0211] FIG9 is a flow chart of a wireless communication method according to another embodiment of the present application. The method shown in FIG9 may include step S910 and step S920.

[0212] In step S910, the first terminal device sends or receives signaling on the first link based on the fourth identifier.

[0213] In some embodiments, the fourth identifier may be one of the following: a default identifier, an identifier determined based on protocol predefined information (or referred to as a protocol predefined identifier), and an identifier determined based on the first mapping relationship.

[0214] The embodiment of the present application does not limit the implementation form of the default identifier or the identifier determined according to the predefined information of the protocol. It can be an identifier set arbitrarily according to actual needs.

[0215] In some embodiments, the default identifier or the identifier predefined by the protocol may be for all terminal devices, that is, all terminal devices may use the same identifier. For example, the default identifier or the identifier predefined by the protocol may be "0000".

[0216] In some embodiments, the default identifier or protocol-predefined identifier can be specific to a terminal device or terminal device group, i.e., different terminal devices can use different identifiers. For example, the default identifier or protocol-predefined identifier can be determined based on the terminal device ID, such as the ID of the end terminal device on the first link (such as the ID of the source terminal device or the ID of the destination terminal device). As an example, the default identifier or protocol-predefined identifier can be the lower N bits (N is a positive integer greater than or equal to 2) of the layer 2 ID of the end terminal device on the first link. As another example, the default identifier or protocol-predefined identifier can be the upper M bits (M is a positive integer greater than or equal to 2) of the layer 2 ID of the end terminal device on the first link. As yet another example, the default identifier or protocol-predefined identifier can be determined based on the higher-layer ID (such as the layer 3 ID, etc.) of the end terminal device on the first link. For example, the default identifier or protocol-predefined identifier can be the lower N bits or the upper M bits of the higher-layer ID of the end terminal device on the first link.

[0217] The embodiment of the present application does not limit the first mapping relationship. For example, the first mapping relationship may be associated with one or more of the following information: service, service identifier, relay service code, terminal device ID, etc.

[0218] In some embodiments, the above-mentioned first mapping relationship may include one or more of the following: a mapping relationship between a service and a fourth identifier, a mapping relationship between a service identifier and a fourth identifier, a mapping relationship between a relay service code and a fourth identifier, a mapping relationship between a layer 2 ID of a terminal device and a fourth identifier, etc.

[0219] In step S920, the first terminal device receives the first identifier configured by the first device.

[0220] After the first terminal device receives the first identifier, data transmission can be performed based on the first identifier.

[0221] For a detailed description of step S920, please refer to the previous description of step S810, which will not be repeated here for the sake of brevity.

[0222] In some embodiments, the identifier configured by the first device may be determined based on the assistance information. The following describes in detail the configuration of the first identifier based on the first assistance information, with reference to FIG10 .

[0223] Figure 10 is a flow chart of a wireless communication method according to another embodiment of the present application. The method shown in Figure 10 may include step S1010 and step S1020.

[0224] In step S1010, a first terminal device sends first assistance information to a first device. The first assistance information is used to determine a first identifier.

[0225] In some embodiments, the sending of the first assistance information is triggered based on a condition, for example, based on a request trigger, or based on an event trigger, etc.

[0226] The embodiments of the present application do not limit the triggering conditions for the first assistance information. Taking the case where the sending of the first assistance information is triggered based on the first condition as an example, the first condition may include one or more of the following: the first terminal device receives a request for assistance information; the first terminal device receives a data packet containing a new identifier or an unknown identifier; the first terminal device establishes a new sidelink based on the relay terminal device; the first terminal device has a conflicting configured identifier; the first terminal device receives second assistance information sent by another terminal device, where the second assistance information is used to determine the identifier associated with the first link, etc.

[0227] As an example, when the first terminal device receives request information for assistance information sent by the first device, the first terminal device may send first assistance information to the first device.

[0228] As another example, when the first terminal device receives a data packet containing a new identifier or an unknown identifier, the first terminal device may send first assistance information to the first device.

[0229] As another example, when the first terminal device receives the second assistance information sent by other terminal devices, it can send the first assistance information to the first device.

[0230] In some embodiments, if a first terminal device receives second assistance information sent by another terminal device, the first terminal device may also send the second assistance information when sending the first assistance information. As one implementation, the first terminal device may send the first assistance information and the second assistance information to the first device. As another implementation, the first terminal device may include the second assistance information in the first assistance information and then send the first assistance information to the first device.

[0231] The embodiments of the present application do not specifically limit the content of the first assistance information. For example, the first assistance information may be associated with one or more of the following information: identification information of the first terminal device, information about terminal devices adjacent to the first terminal device in the first link, and related information about the first terminal device in the first link.

[0232] In some embodiments, the identification information of the first terminal device may include an identification corresponding to the first terminal device on the U2U relay link. In some embodiments, the identification information of the first terminal device may include an ID of the first terminal device (such as a layer 2 ID, a high layer ID, etc.).

[0233] In some embodiments, the first assistance information may include one or more of the following: a configured identifier of the first terminal device; the position of the first terminal device on the first link; a layer 2 identifier of the first terminal device; a layer 2 identifier of the previous-hop terminal device of the first terminal device; a layer 2 identifier of the next-hop terminal device of the first terminal device; or information indicating that the first terminal device is a relay terminal device or an end terminal device.

[0234] In some embodiments, the configured identification of the first terminal device may include an identification of the first terminal device in other links except the first link.

[0235] In some embodiments, the position of the first terminal device on the first link may include one of the following: the first terminal device is at the position of a source terminal device on the first link, the first terminal device is at the position of a target terminal device on the first link, the first terminal device is at the position of a relay terminal device on the first link (such as the specific position of the relay terminal device), the first terminal device is at the position of the hop on the first link, etc.

[0236] In some embodiments, the first assistance information may be sent directly from the first terminal device to the first device.

[0237] In some embodiments, the first assistance information may be sent by the first terminal device to the first terminal device via another terminal device on the first link. For example, the first assistance information may be sent by the first terminal device to the first terminal device via a second terminal device, where the second terminal device is associated with the first terminal device via a single-hop link.

[0238] In step S1020, the first terminal device receives a first identifier configured by the first device.

[0239] For other detailed descriptions of step S1020, please refer to the above description of step S810, which will not be repeated here for the sake of brevity.

[0240] In some embodiments, the first identifier may be configured after the first device receives assistance information sent by each terminal device on the first link, wherein the first device is an external device of the first link.

[0241] In some embodiments, the first identifier may be configured after the first device receives assistance information sent by each terminal device on the first link except the first device, wherein the first device is a terminal device on the first link.

[0242] In some embodiments, the first identifier may be configured after the first device receives assistance information sent by at least one terminal device on the first link.

[0243] In some embodiments, the first identifier may be configured after a first duration has passed since the sending of the distance request information, where the request information is used to request assistance information.

[0244] In some embodiments, the first identifier may be configured after a second time period has elapsed since the connection of the first link was established.

[0245] In some embodiments, the configuration of the first identifier is not related to whether the assistance information is received. In other words, the first device can configure the first identifier without waiting for the assistance information.

[0246] In some embodiments, after receiving the first identifier, the first terminal device may perform data transmission based on the first identifier. For example, in some embodiments, the first terminal device may send or receive a first data packet, and the first data packet includes the first identifier.

[0247] In some embodiments, the first data packet sent or received by the first terminal device may be a data packet of the SRAP layer. In some embodiments, the data packet of the SRAP layer may include a first identifier.

[0248] In some embodiments, after the first terminal device receives the first data packet, it can maintain a mapping relationship between the ingress-hop of the single-hop link corresponding to the first data packet and the egress-hop of the single-hop link, so as to send the first data packet to the terminal device corresponding to the next hop.

[0249] Taking the example of a first terminal device being associated with a second single-hop link and a third single-hop link, the first identifier can be used to identify the second single-hop link, and the first data packet is a data packet transmitted to the first terminal device via the second single-hop link. In this case, the first terminal device can replace the first identifier with the fifth identifier and forward the first data packet via the third single-hop link. The fifth identifier can be used to identify the third single-hop link.

[0250] In some embodiments, the fifth identifier is determined by the first terminal device based on a mapping relationship between the first identifier and the fifth identifier, and the first identifier.

[0251] For ease of understanding, several embodiments are given below using different functions of the first identifier as an example. It should be noted that the embodiments mentioned below are for illustration only.

[0252] Example 1: The first identifier is used to identify the first link

[0253] In embodiment 1, the first identifier can be used to identify a complete U2U relay link (first link).

[0254] In Example 1, the first identifier, serving as the identifier of the first link, may be carried in the first data packet (e.g., a data packet at the SRAP layer). Thus, when a terminal device on the first link receives the first data packet, it can know which link the first data packet belongs to, and thus how to process the first data packet.

[0255] In some embodiments, the first identifier in embodiment 1 can also be used to identify an end terminal device on the first link. In this way, the first link can be identified based on the identifiers of the two end terminal devices.

[0256] In embodiment 1, the first identifier may be allocated by the first device. In other words, in embodiment 1, the identifier associated with the first link may be configured by a central node, which is the first device.

[0257] In some embodiments, the first device may be one of the following: an end terminal device on the first link, a target relay terminal device on the first link, or an external device of the first link.

[0258] In some embodiments, the target relay terminal device on the first link may include one or more of the following: a relay terminal device with the least relay hops from the end terminal device on the first link, a relay terminal device indicated by an upper layer (such as an application layer, a ProSe layer, a V2X layer, etc.), a relay terminal device determined according to the terminal device capabilities of the relay terminal device on the first link, a relay terminal device on the first link that is within the coverage of a network device, and a relay terminal device at the center of the first link.

[0259] In some embodiments, the external device of the first link may include one or more of the following: a service terminal device of the terminal device on the first link, and a network device.

[0260] In some embodiments, the serving terminal device of the terminal device on the first link may be, for example, the serving terminal device of the end terminal device on the first link. In some embodiments, the serving terminal device of the terminal device on the first link may be, for example, the serving terminal device of the relay terminal device on the first link.

[0261] In some embodiments, after the first device configures the first identifier, it can send the first identifier to each terminal device on the first link. As an implementation method, the first device can directly send the first identifier to each terminal device on the first link. That is, the first device can send the first identifier to each terminal device across hops. As another implementation method, the first device can send the first identifier to each terminal device on the first link through other terminal devices on the first link. For example, the first device can send the first identifier to a terminal device directly connected to the first device, and each terminal device can send it to the next terminal device directly connected to itself in turn.

[0262] The following introduces these two implementation methods respectively.

[0263] Implementation method 1: The first device directly sends the first identifier to each terminal device on the first link

[0264] Taking the first device as an end terminal device on the first link as an example, the end terminal device on the first link can directly send the first identifier to each terminal device on the first link. For example, the first device can be a source terminal device, and the source terminal device can send the first identifier to the target terminal device and each relay terminal device. Alternatively, the first device can be a target terminal device, and the target terminal device can send the first identifier to the source terminal device and each relay terminal device. Figure 11 shows a situation where the first device is a source terminal device and the source terminal device can send the first identifier to the target terminal device and each relay terminal device.

[0265] Taking the first device as a relay terminal device on the first link as an example, referring to FIG12 , the relay terminal device on the first link can directly send the first identifier to the two end terminal devices and other relay terminal devices on the first link.

[0266] Taking the first device as a serving terminal device on the first link as an example, referring to FIG13 , the serving terminal device may directly send the first identifier to each terminal device on the first link (including two end terminal devices and each relay terminal device).

[0267] In some embodiments, the first identifier may be carried in a PC5-RRC message or a PC5-S message.

[0268] In some embodiments, if the first identifier is carried in a PC5-RRC message, the PC5-RRC message may include configuration information of the SRAP layer.

[0269] In some embodiments, the first identifier may not distinguish the data transmission direction. In other words, the same single-hop link may correspond to only one identifier, and the identifier can be used in both data transmission directions corresponding to the single-hop link.

[0270] In some embodiments, the first identifier can distinguish the direction of data transmission. In other words, the same single-hop link can correspond to two identifiers, and the two identifiers correspond to the two data transmission directions corresponding to the single-hop link (or the two identifiers are used for different data transmission directions). Taking the single-hop link between the first relay terminal device and the second relay terminal device as an example, the first relay terminal device can use the identifier configured by the first relay terminal device when sending data to the second relay terminal device, and the second relay terminal device can use the identifier configured by the second relay terminal device when sending data to the first relay terminal device.

[0271] In some embodiments, before a terminal device on the first link receives an identifier configured by the first device, the terminal device on the first link may use a fourth identifier to send or receive data or signaling on the first link. The fourth identifier may be one or more of the following: a default identifier, an identifier determined based on protocol predefined information, or an identifier determined based on the first mapping relationship.

[0272] In some embodiments, the default identifier or the identifier determined based on protocol predefined information can be, for example, "0000", or the low / high N bits of the layer 2 ID of the end terminal device on the first link, or the high layer ID of the end terminal device on the first link, etc.

[0273] In some embodiments, the above-mentioned first mapping relationship may include one or more of the following: a mapping relationship between a service and a fourth identifier, a mapping relationship between a service identifier and a fourth identifier, a mapping relationship between a relay service code and a fourth identifier, and a mapping relationship between a layer 2 identifier of a terminal device and a fourth identifier.

[0274] In some embodiments, each terminal device on the first link may send assistance information to the first device to determine the first identifier.

[0275] In some embodiments, the assistance information may be request-triggered or event-triggered.

[0276] In some embodiments, the triggering conditions of the assistance information may include one or more of the following: receiving a request for assistance information sent by the first device, receiving a data packet containing a new identifier or an unknown identifier, establishing a new side link based on a relay terminal device (or establishing a new side link for relay services), and a conflict in the configured identifier.

[0277] In some embodiments, the assistance information may include one or more of the following: an identifier currently configured of the terminal device sending the assistance information (for example, an identifier on other U2U relay links), the hop number of the terminal device sending the assistance information, the layer 2 ID of the terminal device sending the assistance information, the layer 2 ID of the terminal device of the previous hop of the terminal device sending the assistance information, the layer 2 ID of the terminal device of the next hop of the terminal device sending the assistance information, and information indicating that the terminal device sending the assistance information is a relay terminal device or an end terminal device.

[0278] In some embodiments, the first identifier may be configured after the first device receives assistance information sent by each terminal device on the first link, wherein the first device is an external device of the first link.

[0279] In some embodiments, the first identifier may be configured after the first device receives assistance information sent by each terminal device on the first link except the first device, wherein the first device is a terminal device on the first link.

[0280] In some embodiments, the first identifier may be configured after the first device receives assistance information sent by at least one terminal device on the first link.

[0281] In some embodiments, the first identifier may be configured after a first duration has passed since the sending of the distance request information, where the request information is used to request assistance information.

[0282] In some embodiments, the first identifier may be configured after a second time period has elapsed since the connection of the first link was established.

[0283] In some embodiments, the configuration of the first identifier is irrelevant to whether assistance information is received.

[0284] Implementation method 2: The first device sends the first identifier to the terminal device directly connected to the first device

[0285] After the first device sends the first identifier to the terminal device directly connected to the first device, each terminal device sends the first identifier to the next terminal device directly connected to itself in turn.

[0286] Taking the first device as an end terminal device on the first link as an example, the end terminal device on the first link can send the first identifier to the first relay terminal device connected to it, and then the first relay terminal device sends the first identifier to the second relay terminal device directly connected to it, and so on. For example, the first device can be a source terminal device, and the source terminal device can send the first identifier to the first relay terminal device connected to it, and then the first relay terminal device sends the first identifier to the second relay terminal device directly connected to it, and so on, until a certain relay terminal device sends the first identifier to the target terminal device directly connected to it. Alternatively, the first device can be a target terminal device, and the target terminal device can send the first identifier to the first relay terminal device connected to it, and then the first relay terminal device sends the first identifier to the second relay terminal device directly connected to it, and so on, until a certain relay terminal device sends the first identifier to the source terminal device directly connected to it. Figure 14 shows a situation where the first device is a source terminal device and the source terminal device sends the first identifier.

[0287] Taking the example of the first device being a relay terminal device on the first link, the relay terminal device can send the first identifier to the end terminal device directly connected to it and / or other relay terminal devices, and then the other relay terminal devices can sequentially send the first identifier to the terminal devices directly connected to them. Referring to Figure 15, the first device is relay terminal device 1 on the first link. Relay terminal device 1 can send the first identifier to the source terminal device directly connected to it and relay terminal device 2, and then relay terminal device 2 can send the first identifier to the target terminal device.

[0288] Taking the example of a first device being a serving terminal device on a first link, the serving terminal device can send a first identifier to a terminal device on the first link directly connected to it, and then the terminal device directly connected to the serving terminal device can sequentially send the first identifier to other terminal devices directly connected to it. Referring to Figure 16 , the first device is a serving terminal device of relay terminal device 1. The serving terminal device can send the first identifier to relay terminal device 1 directly connected to it, and then relay terminal device 1 can send the first identifier to the source terminal device and relay terminal device 2 directly connected to it, and then relay terminal device 2 can send the first identifier to the target terminal device directly connected to it.

[0289] In some embodiments, the first identifier may be carried in a PC5-RRC message or a PC5-S message.

[0290] In some embodiments, if the first identifier is carried in a PC5-RRC message, the PC5-RRC message may include configuration information of the SRAP layer.

[0291] In some embodiments, the first identifier may not distinguish the data transmission direction. In other words, the same single-hop link may correspond to only one identifier, and the identifier can be used in both data transmission directions corresponding to the single-hop link.

[0292] In some embodiments, the first identifier can distinguish the direction of data transmission. In other words, the same single-hop link can correspond to two identifiers, and the two identifiers correspond to the two data transmission directions corresponding to the single-hop link (or the two identifiers are used for different data transmission directions). Taking the single-hop link between the first relay terminal device and the second relay terminal device as an example, the first relay terminal device can use the identifier configured by the first relay terminal device when sending data to the second relay terminal device, and the second relay terminal device can use the identifier configured by the second relay terminal device when sending data to the first relay terminal device.

[0293] In some embodiments, before a terminal device on the first link receives an identifier configured by the first device, the terminal device on the first link may use a fourth identifier to send or receive data or signaling on the first link. The fourth identifier may be one or more of the following: a default identifier, an identifier determined based on protocol predefined information, or an identifier determined based on the first mapping relationship.

[0294] In some embodiments, the default identifier or the identifier determined based on protocol predefined information can be, for example, "0000", or the low / high N bits of the layer 2 ID of the end terminal device on the first link, or the high layer ID of the end terminal device on the first link, etc.

[0295] In some embodiments, the above-mentioned first mapping relationship may include one or more of the following: a mapping relationship between a service and a fourth identifier, a mapping relationship between a service identifier and a fourth identifier, a mapping relationship between a relay service code and a fourth identifier, and a mapping relationship between a layer 2 identifier of a terminal device and a fourth identifier.

[0296] In some embodiments, each terminal device on the first link may send assistance information to the first device to determine the first identifier.

[0297] In some embodiments, the assistance information can be sent by each terminal device on the first link to the terminal device of the previous hop directly connected to itself. The terminal device that receives the assistance information can add its own corresponding information to it and pass it forward again (if the terminal device is not the first device) until the assistance information is delivered to the first device.

[0298] Figure 17 shows a scenario where the first device is a source terminal device and the source terminal device receives assistance information. As shown in Figure 17, the target terminal device can send assistance information to relay terminal device 2, which is directly connected to it. Relay terminal device 2 can add its own corresponding information to the assistance information and send the assistance information to relay terminal device 1. Subsequently, relay terminal device 1 can add its own corresponding information to the assistance information and send the assistance information to the source terminal device.

[0299] Figure 18 illustrates a scenario where the first device is a relay terminal device, which receives assistance information. As shown in Figure 18, the first device is relay terminal device 1. The source terminal device can send assistance information to relay terminal device 1, which is directly connected to it. The destination terminal device can send assistance information to relay terminal device 2, which is directly connected to it. Relay terminal device 2 can add its own information to the assistance information and send the assistance information to relay terminal device 1.

[0300] Figure 19 illustrates a situation where the first device is a service terminal device that receives assistance information. As shown in Figure 19, the first device is a service terminal device of relay terminal device 1. The source terminal device can send assistance information to relay terminal device 1, to which it is directly connected. The target terminal device can send assistance information to relay terminal device 2, to which it is directly connected. Relay terminal device 2 can add its own corresponding information to the assistance information and send the assistance information to relay terminal device 1. Afterwards, relay terminal device 1 can combine the assistance information sent by the source terminal device and relay terminal device 2, add its own corresponding information to the assistance information, and finally send the assistance information to the service terminal device.

[0301] In some embodiments, the assistance information may be request-triggered or event-triggered.

[0302] In some embodiments, the triggering conditions for the assistance information may include one or more of the following: receiving a request for assistance information sent by the first device, receiving a data packet containing a new identifier or an unknown identifier, establishing a new side link based on a relay terminal device (or establishing a new side link for relay services), a conflict in the configured identifier, and receiving assistance information sent by other terminal devices.

[0303] In some embodiments, the assistance information may include one or more of the following: an identifier currently configured of the terminal device sending the assistance information (for example, an identifier on other U2U relay links), the hop number of the terminal device sending the assistance information, the layer 2 ID of the terminal device sending the assistance information, the layer 2 ID of the terminal device of the previous hop of the terminal device sending the assistance information, the layer 2 ID of the terminal device of the next hop of the terminal device sending the assistance information, and information indicating that the terminal device sending the assistance information is a relay terminal device or an end terminal device.

[0304] In some embodiments, the first identifier may be configured after the first device receives assistance information sent by each terminal device on the first link, wherein the first device is an external device of the first link.

[0305] In some embodiments, the first identifier may be configured after the first device receives assistance information sent by each terminal device on the first link except the first device, wherein the first device is a terminal device on the first link.

[0306] In some embodiments, the first identifier may be configured after the first device receives assistance information sent by at least one terminal device on the first link.

[0307] In some embodiments, the first identifier may be configured after a first duration has passed since the sending of the distance request information, where the request information is used to request assistance information.

[0308] In some embodiments, the first identifier may be configured after a second time period has elapsed since the connection of the first link was established.

[0309] In some embodiments, the configuration of the first identifier is irrelevant to whether assistance information is received.

[0310] Embodiment 2: The first identifier is used to identify a single-hop link on the first link

[0311] In Example 2, the first identifier, as an identifier of a single-hop link on the first link, can be carried in the first data packet (e.g., a data packet at the SRAP layer). In this way, when a terminal device on the first link receives the first data packet, it can know which hop the first data packet comes from and which hop it should be destined for, and / or how to process the data packet.

[0312] In some embodiments, each relay terminal device needs to maintain a mapping relationship between ingress-hop and egress-hop. For example, each relay terminal device needs to fill in one or more of the following information in the first data packet.

[0313] Information 1: egress-hop identifier. For example, after receiving the first data packet, each relay terminal device can re-fill the egress-hop identifier of the first data packet according to the identifier carried in the first data packet and the mapping relationship between the ingress-hop identifier and the egress-hop identifier.

[0314] Information 2: ingress-hop identifier and egress-hop identifier. In some embodiments, the ingress-hop identifier of the end terminal device can be empty or a default value (such as 0000, 1111, etc.). In some embodiments, after each relay terminal device receives the first data packet, it can re-fill the egress-hop identifier of the first data packet based on the identifier carried in the first data packet and the mapping relationship between the ingress-hop identifier and the egress-hop identifier.

[0315] In some embodiments, the identifiers of each single-hop link on the first link are configured by a single device, i.e., the identifiers of the first link are configured by a central node. In some embodiments, the identifiers of each single-hop link on the first link are configured by multiple devices, i.e., the identifiers of the first link are configured by distributed nodes. This is described below in conjunction with Example 2.1 and Example 2.2.

[0316] Example 2.1: Central Node Configuration Identifier

[0317] That is, the first device (central node) may configure the identifier of each single-hop link on the first link.

[0318] For an introduction to the first device, please refer to the introduction to Example 1, which will not be repeated here for the sake of brevity.

[0319] In some embodiments, after the first device configures the identifiers of each single-hop link, it can send each identifier to each terminal device on the first link. As an implementation method, the first device can directly send each identifier to the terminal device associated with each identifier. That is, the first device can send each identifier to each terminal device across hops. As another implementation method, the first device can send each identifier to each terminal device on the first link through other terminal devices on the first link. For example, the first device can send the first identifier to the terminal device directly connected to the first device, and each terminal device will send one or more identifiers associated with subsequent terminal devices to the next terminal device directly connected to the terminal device in turn.

[0320] The following introduces these two implementation methods respectively.

[0321] Implementation method 1: The first device directly sends the identifier of each single-hop link to each terminal device on the first link

[0322] Figure 20 illustrates a scenario where the first device is a source terminal device, which configures the identifiers of each single-hop link. As shown in Figure 20 , the source terminal device can directly send two identifiers, ID1 and ID2, associated with relay terminal device 1 to relay terminal device 1. The source terminal device can also directly send two identifiers, ID2 and ID3, associated with relay terminal device 2 to relay terminal device 2. The source terminal device can also directly send one identifier, ID3, associated with a target terminal device to the target terminal device.

[0323] Figure 21 illustrates a scenario where the first device is a relay terminal device, which configures identifiers for each single-hop link. As shown in Figure 21, the first device is relay terminal device 1. Relay terminal device 1 can directly send an identifier, ID1, associated with a source terminal device to the source terminal device. Relay terminal device 1 can directly send two identifiers, ID2 and ID3, associated with relay terminal device 2 to relay terminal device 2. Relay terminal device 1 can directly send an identifier, ID3, associated with a target terminal device to the target terminal device.

[0324] Figure 22 illustrates a scenario where the first device is a service terminal device, which configures identifiers for each single-hop link. As shown in Figure 22 , the service terminal device can directly send an identifier, ID1, associated with the source terminal device to the source terminal device. The service terminal device can directly send two identifiers, ID1 and ID2, associated with relay terminal device 1 to relay terminal device 1. The service terminal device can directly send two identifiers, ID2 and ID3, associated with relay terminal device 2 to relay terminal device 2. The service terminal device can directly send an identifier, ID3, associated with the target terminal device to the target terminal device.

[0325] For other solutions not described in detail, please refer to the introduction of Example 1, such as the carrying method of the identifier, the sending of the assistance information, etc. For the sake of brevity, they will not be described here.

[0326] Implementation 2: The first device sends the identifier of each single-hop link to the terminal device directly connected to the first device

[0327] After the first device sends the first identifier to the terminal device directly connected to the first device, each terminal device configures the identifiers of one or more single-hop links associated with the terminal device, and sends the identifiers of one or more single-hop links associated with subsequent terminal devices to the next terminal device directly connected to the terminal device in sequence.

[0328] Figure 23 illustrates a scenario where the first device is a source terminal device, which configures identifiers for each single-hop link. As shown in Figure 23, the source terminal device can send three identifiers, ID1, ID2, and ID3, associated with subsequent terminal devices to relay terminal device 1, directly connected to it. Relay terminal device 1 can send two identifiers, ID2 and ID3, associated with subsequent terminal devices to relay terminal device 2, directly connected to it. Relay terminal device 2 can send one identifier, ID3, associated with subsequent terminal devices to a target terminal device, directly connected to it.

[0329] Figure 24 illustrates a scenario where the first device is a relay terminal device, which configures identifiers for each single-hop link. As shown in Figure 24, the first device is relay terminal device 1. Relay terminal device 1 can send an identifier, ID1, associated with a subsequent terminal device to the source terminal device directly connected to it, and send two identifiers, ID2 and ID3, associated with the subsequent terminal device to relay terminal device 2 directly connected to it. Relay terminal device 2 can send an identifier, ID3, associated with the subsequent terminal device to the target terminal device directly connected to it.

[0330] Figure 25 illustrates a situation where the first device is a service terminal device, and the service terminal device configures identifiers for each single-hop link. As shown in Figure 25, the first device is a service terminal device for a source terminal device. The service terminal device can send the three identifiers ID1, ID2, and ID3 associated with a subsequent terminal device to the source terminal device directly connected to it. The source terminal device can send the three identifiers ID1, ID2, and ID3 associated with a subsequent terminal device to relay terminal device 1 directly connected to it. Relay terminal device 1 can send two identifiers ID2 and ID3 associated with a subsequent terminal device to relay terminal device 2 directly connected to it. Relay terminal device 2 can send one identifier ID3 associated with a subsequent terminal device to a target terminal device directly connected to it.

[0331] For other solutions not described in detail, please refer to the introduction of Example 1, such as the carrying method of the identifier, the sending of the assistance information, etc. For the sake of brevity, they will not be described here.

[0332] Example 2.2: Distributed node configuration identification

[0333] That is, the identifiers of all single-hop links on the first link may be configured by different devices.

[0334] In some embodiments, the identifier of each single-hop link on the first link may be configured by a terminal device associated with the single-hop link.

[0335] In some embodiments, the terminal device on the first link may configure an identifier of the single-hop link associated with itself.

[0336] In some embodiments, after the terminal device on the first link configures the identifier of the single-hop link associated with itself, the identifier may be sent to other terminal devices associated with the single-hop link.

[0337] In some embodiments, both the end terminal device and the relay terminal device on the first link participate in configuring the identifier on the first link. For example, each terminal device on the first link can configure the identifier of a single-hop link on the first link.

[0338] As an implementation method, the identifier of each single-hop link on the first link can be configured by the terminal device at the starting end of the single-hop link. Referring to Figure 26, the source terminal device, as the terminal device at the starting end of the single-hop link between the source terminal device and the relay terminal device 1, can configure the identifier ID1 of the single-hop link between the source terminal device and the relay terminal device 1, and send the identifier ID1 to the relay terminal device 1. The relay terminal device 1, as the terminal device at the starting end of the single-hop link between the relay terminal device 1 and the relay terminal device 2, can configure the identifier ID2 of the single-hop link between the relay terminal device 1 and the relay terminal device 2, and send the identifier ID2 to the relay terminal device 2. The relay terminal device 2, as the terminal device at the starting end of the single-hop link between the relay terminal device 2 and the target terminal device, can configure the identifier ID3 of the single-hop link between the relay terminal device 2 and the target terminal device, and send the identifier ID3 to the target terminal device.

[0339] In some embodiments, the relay terminal device on the first link participates in the configuration of the identifier on the first link, while the end terminal device on the first link does not participate in the configuration of the identifier on the first link. For example, each relay terminal device on the first link can configure the identifiers of the two single-hop links associated with it.

[0340] As an implementation method, referring to FIG27 , relay terminal device 1 can configure identifiers ID1 and ID2 of two single-hop links associated with itself, and send the configured identifiers ID1 and ID2 to the source terminal device and relay terminal device 2, respectively. Relay terminal device 2 can configure identifiers ID3 and ID4 of two single-hop links associated with itself, and send the configured identifiers ID3 and ID4 to relay terminal device 1 and the target terminal device, respectively.

[0341] In some embodiments, for a single-hop link between two relay terminal devices, a conflict between two identifiers corresponding to the single-hop link may occur. For example, referring to FIG27 , a single-hop link between relay terminal device 1 and relay terminal device 2 may be configured with two identifiers, ID2 and ID3, resulting in an identifier conflict.

[0342] In order to avoid the above problems, the embodiments of the present application provide the following solutions.

[0343] Solution 1: A single-hop link between two relay terminal devices uses only one identifier.

[0344] As a possible implementation, the identifier used for a single-hop link between two relay terminal devices is configured by one relay terminal device. For example, the identifier can be configured by the following relay terminal devices: the relay terminal device that sends the identifier first, the relay terminal device that sends the assistance information request first, the relay terminal device with higher terminal capabilities, the relay terminal device determined by coordination between two relay terminal devices, the relay terminal device that initiates the sidelink connection establishment, etc.

[0345] As another possible implementation, the identifier used for a single-hop link between two relay terminal devices is selected after configuration by the two relay terminal devices. For example, if one relay terminal device is configured with a second identifier for the single-hop link, and the other relay terminal device is configured with a third identifier for the single-hop link, the single-hop link can transmit data based on a target identifier selected between the second identifier and the third identifier.

[0346] In some embodiments, the target identifier is the identifier with the smaller value between the second identifier and the third identifier.

[0347] In some embodiments, the target identifier is the identifier with the larger value between the second identifier and the third identifier.

[0348] Solution 2: Use two identifiers for a single-hop link between two relay terminal devices.

[0349] As a possible implementation, two relay terminal devices can configure identifiers for the single-hop link between them, and the two configured identifiers can be associated with different data transmission directions. Taking Figure 27 as an example, relay terminal device 1 configures identifier ID2 for the single-hop link between relay terminal device 1 and relay terminal device 2, and relay terminal device 2 configures identifier ID3 for the single-hop link between relay terminal device 1 and relay terminal device 2. When relay terminal device 1 sends data to relay terminal device 2, it can use identifier ID2 configured by relay terminal device 1, and when relay terminal device 2 sends data to relay terminal device 1, it can use identifier ID3 configured by relay terminal device 2.

[0350] For other solutions not described in detail, please refer to the introduction of Example 1, such as the carrying method of the identifier, the sending of the assistance information, etc. For the sake of brevity, they will not be described here.

[0351] In some embodiments, the solution of embodiment 2 can be further extended so that the first identifier is used to identify a terminal device on the first link. In this case, the first link can be determined based on the terminal device identifiers of each terminal device on the first link.

[0352] Embodiment 3: The first identifier is used to identify multiple single-hop links on the first link

[0353] In embodiment 3, the first identifier can be used to identify multiple single-hop links on the first link. For example, the first identifier can be used to identify two single-hop links associated with a relay terminal device on the first link.

[0354] In some embodiments, if the first identifier is used to identify two single-hop links associated with a relay terminal device on a first link, the first device configured with the first identifier may be the relay terminal device. Taking the example of the first identifier being used to identify two single-hop links associated with a first relay terminal device on the first link, the first device is the first relay terminal device.

[0355] In some embodiments, after the relay terminal device configures the identifiers of the two single-hop links associated with itself, it can send the configured identifiers to other terminal devices (such as end terminal devices or relay terminal devices) associated with the two single-hop links.

[0356] In some embodiments, some relay terminal devices and some end terminal devices on the first link participate in the configuration of the identifier associated with the first link.

[0357] As a possible implementation, referring to FIG28 , the relay terminal device 1 and the target terminal device on the first link participate in the configuration of the identifier associated with the first link, while the source terminal device and the relay terminal device 2 do not participate in the configuration of the identifier associated with the first link. Relay terminal device 1 can configure the identifiers of two single-hop links associated with itself, and the identifiers of the two single-hop links are the same (both are ID1), while the target terminal device can configure the identifier of one single-hop link associated with itself (ID2).

[0358] As another possible implementation, referring to FIG. 29 , the source terminal device and the relay terminal device 2 may participate in the configuration of the identifier associated with the first link, while the relay terminal device 1 and the end terminal device may not participate in the configuration of the identifier associated with the first link.

[0359] In some embodiments, some or all relay terminal devices on the first link participate in the configuration of the identifier associated with the first link. For example, only some relay terminal devices on the first link participate in the configuration of the identifier associated with the first link, while the end terminal devices do not participate in the configuration of the identifier associated with the first link. Alternatively, only all relay terminal devices on the first link participate in the configuration of the identifier associated with the first link, while the end terminal devices do not participate in the configuration of the identifier associated with the first link.

[0360] As a possible implementation, referring to FIG30 , the relay terminal device 1 and the relay terminal device 3 on the first link participate in the configuration of the identifier associated with the first link. Relay terminal device 1 can configure the identifiers of the two single-hop links associated with itself, and the identifiers of the two single-hop links are the same (both are ID1), and relay terminal device 3 can configure the identifiers of the two single-hop links associated with itself, and the identifiers of the two single-hop links are the same (both are ID2).

[0361] As another possible implementation, referring to FIG31 , the relay terminal device 1, the relay terminal device 2 and the relay terminal device 3 on the first link all participate in the configuration of the identifier associated with the first link. Among them, the relay terminal device 1 can configure the identifiers of the two single-hop links associated with itself, and the identifiers of the two single-hop links are the same (both are ID1), and the relay terminal device 2 can configure the identifiers of the two single-hop links associated with itself, and the identifiers of the two single-hop links are the same (both are ID2). The relay terminal device 3 can configure the identifiers of the two single-hop links associated with itself, and the identifiers of the two single-hop links are the same (both are ID3). In this case, the single-hop link between the relay terminal device 1 and the relay terminal device 2 may be configured with two identifiers, and the single-hop link between the relay terminal device 2 and the relay terminal device 3 may also be configured with two identifiers, resulting in an identifier conflict. For the relevant introduction on how to resolve the identifier conflict, please refer to the previous introduction. For the sake of brevity, it will not be repeated here.

[0362] As another possible implementation, the relay terminal device 1 in Figure 28 can configure the identifiers of the two single-hop links associated with itself, and the identifiers of the two single-hop links are the same (both are ID1), while the relay terminal device 2 can configure the identifiers of the two single-hop links associated with itself (both are ID2). In this case, the single-hop link between the relay terminal device 1 and the relay terminal device 2 may be configured with two identifiers, resulting in an identifier conflict. For the relevant introduction on how to resolve the identifier conflict, please refer to the previous introduction. For the sake of brevity, it will not be repeated here.

[0363] For other solutions not described in detail, please refer to the introduction of Example 1, such as the carrying method of the identifier, the sending of the assistance information, etc. For the sake of brevity, they will not be described here.

[0364] In some embodiments, the solution of embodiment 3 can be further extended so that the first identifier is used to identify a terminal device on the first link. In this case, the first link can be determined based on the terminal device identifiers of each terminal device on the first link.

[0365] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 31. The device embodiment of the present application is described in detail below in conjunction with Figures 32 to 34. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment. Therefore, for parts not described in detail, reference can be made to the above method embodiment.

[0366] FIG32 is a schematic diagram of the structure of a terminal device provided in an embodiment of the present application. The terminal device 3200 shown in FIG32 may include a receiving module 3210.

[0367] The receiving module 3210 can be used to receive a first identifier configured by a first device, where the first identifier is used to transmit data on a first link; wherein the first link is a side link, and the first link passes through multiple relay terminal devices.

[0368] Optionally, the first identifier is used to identify one of the following: the first link; a single-hop link on the first link; multiple single-hop links on the first link; and a terminal device on the first link.

[0369] Optionally, the first identifier includes a terminal device identifier of an end terminal device on the first link, and the first link is determined based on the terminal device identifiers of two end terminal devices on the first link.

[0370] Optionally, the first device is one of the following: an end terminal device on the first link; a target relay terminal device on the first link; and an external device of the first link.

[0371] Optionally, the target relay terminal device is determined based on one or more of: the number of relay hops between the relay terminal device and the end terminal device on the first link; the first indication information sent by the upper layer; the terminal device capability of the relay terminal device on the first link; whether the relay terminal device on the first link is within the coverage of the network device; and the position of the relay terminal device on the first link in the first link.

[0372] Optionally, the target relay terminal device is one or more of the following: a relay terminal device on the first link with the least number of relay hops from the end terminal device; a terminal device indicated by the first indication information sent by the upper layer; a relay terminal device on the first link that is within the coverage of the network device; and a relay terminal device at the center of the first link.

[0373] Optionally, the external device is one of the following: a service terminal device of the terminal device on the first link; and a network device.

[0374] Optionally, the first identifier is used to identify a first single-hop link on the first link, the first single-hop link is associated with the first terminal device and the second terminal device, and the first device is the second terminal device; or the first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

[0375] Optionally, the first link includes N single-hop links, each of the N single-hop links corresponds to an identifier, and the identifier corresponding to each single-hop link is configured by a terminal device associated with each single-hop link, and N is a positive integer greater than or equal to 2.

[0376] Optionally, the first link includes M relay terminal devices, each of the M relay terminal devices is associated with two single-hop links on the first link, and each relay terminal device is used to configure identifiers for the two single-hop links associated with each relay terminal device, where M is a positive integer greater than or equal to 2.

[0377] Optionally, the first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link, the second identifier is associated with the first transmission direction of the first single-hop link, and the third identifier is associated with the second transmission direction of the first single-hop link.

[0378] Optionally, the first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link; for the first relay terminal device, the first single-hop link transmits data based on the mapping relationship between the second identifier and the third identifier and the second identifier; for the second relay terminal device, the first single-hop link transmits data based on the mapping relationship between the second identifier and the third identifier and the third identifier.

[0379] Optionally, the first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, and the first single-hop link transmits data based on an identifier configured by the first relay terminal device.

[0380] Optionally, the first relay terminal device sends the identifier of the first single-hop link earlier than the second relay terminal device sends the identifier of the first single-hop link; or, the first relay terminal device sends assistance information earlier than the second relay terminal device sends assistance information, and the assistance information is used to determine the identifier corresponding to the first single-hop link; or, the terminal device capability of the first relay terminal device is higher than the terminal device capability of the second relay terminal device; or, the first relay terminal device and the second relay terminal device negotiate to determine that the identifier of the first single-hop link is configured by the first relay terminal device; or, the connection establishment request for establishing the first single-hop link is initiated by the first relay terminal device.

[0381] Optionally, the first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link, and the first single-hop link transmits data based on a target identifier among the second identifier and the third identifier.

[0382] Optionally, the target identifier is the identifier with the smaller value between the second identifier and the third identifier; or, the target identifier is the identifier with the larger value between the second identifier and the third identifier.

[0383] Optionally, the first identifier is used to identify two single-hop links associated with a first relay terminal device on the first link, and the first device is the first relay terminal device; or the first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

[0384] Optionally, the first identifier is carried by a first message, and the first message is a PC5-RRC message or a PC5-S message.

[0385] Optionally, the first message is a PC5-RRC message, the first message includes configuration information of the SRAP layer, and the configuration information includes the first identifier.

[0386] Optionally, the terminal device also includes: a first communication module 3220, used to send or receive signaling on the first link based on a fourth identifier; wherein the fourth identifier is one of the following: a default identifier; an identifier determined based on protocol predefined information; and an identifier determined based on the first mapping relationship.

[0387] Optionally, the first mapping relationship includes one or more of the following: a mapping relationship between a service and the fourth identifier; a mapping relationship between a service identifier and the fourth identifier; a mapping relationship between a relay service code and the fourth identifier; and a mapping relationship between a layer 2 identifier of a terminal device and the fourth identifier.

[0388] Optionally, the terminal device further includes: a sending module, configured to send first assistance information to the first device, where the first assistance information is used to determine the first identifier.

[0389] Optionally, the sending of the first assistance information is triggered based on a first condition, and the first condition includes one or more of the following: the first terminal device receives a request for assistance information; the first terminal device receives a data packet containing a new identifier or an unknown identifier; the first terminal device establishes a new side link based on a relay terminal device; there is a conflict in the configured identifier of the first terminal device; and the first terminal device receives second assistance information sent by other terminal devices, and the second assistance information is used to determine the identifier associated with the first link.

[0390] Optionally, the first assistance information includes one or more of the following: a configured identifier of the first terminal device; the position of the first terminal device on the first link; a layer 2 identifier of the first terminal device; a layer 2 identifier of the previous-hop terminal device of the first terminal device; a layer 2 identifier of the next-hop terminal device of the first terminal device; and information indicating that the first terminal device is a relay terminal device or an end terminal device.

[0391] Optionally, the first assistance information is sent directly from the first terminal device to the first device; or, the first assistance information is sent from the first terminal device to the first device via a second terminal device; wherein the second terminal device is associated with the first terminal device via a single-hop link.

[0392] Optionally, the first identifier is sent directly by the first device to the first terminal device; or, the first identifier is sent by the first device to the first terminal device via a second terminal device; wherein the second terminal device is associated with the first terminal device via a single-hop link.

[0393] Optionally, the terminal device further includes: a second communication module, configured to send or receive a first data packet, where the first data packet is a data packet of the SRAP layer, and the first data packet includes the first identifier.

[0394] Optionally, the first terminal device is associated with a second single-hop link and a third single-hop link, the first identifier is used to identify the second single-hop link, the first data packet is a data packet transmitted through the second single-hop link, and the terminal device further includes: a forwarding module, used to forward the first data packet through the third single-hop link after the first terminal device replaces the first identifier with a fifth identifier; wherein the fifth identifier is used to identify the third single-hop link.

[0395] FIG33 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. The communication device 3300 shown in FIG33 can be any of the first devices described above. The communication device 3300 can include a sending module 3310.

[0396] The sending module 3310 can be used to send a first identifier configured by the first device to a first terminal device, where the first identifier is used to transmit data on a first link; wherein the first link is a side link, and the first link passes through multiple relay terminal devices.

[0397] Optionally, the first identifier is used to identify one of the following: the first link; a single-hop link on the first link; multiple single-hop links on the first link; and a terminal device on the first link.

[0398] Optionally, the first identifier includes a terminal device identifier of an end terminal device on the first link, and the first link is determined based on the terminal device identifiers of two end terminal devices of the first link.

[0399] Optionally, the first device is one of the following: an end terminal device on the first link; a target relay terminal device on the first link; and an external device of the first link.

[0400] Optionally, the target relay terminal device is determined based on one or more of: the number of relay hops between the relay terminal device and the end terminal device on the first link; the first indication information sent by the upper layer; the terminal device capability of the relay terminal device on the first link; whether the relay terminal device on the first link is within the coverage of the network device; and the position of the relay terminal device on the first link in the first link.

[0401] Optionally, the target relay terminal device is one or more of the following: a relay terminal device on the first link with the least number of relay hops from the end terminal device; a terminal device indicated by the first indication information sent by the upper layer; a relay terminal device on the first link that is within the coverage of the network device; and a relay terminal device at the center of the first link.

[0402] Optionally, the external device is one of the following: a service terminal device of the terminal device on the first link; and a network device.

[0403] Optionally, the first identifier is used to identify a first single-hop link on the first link, the first single-hop link is associated with the first terminal device and the second terminal device, and the first device is the second terminal device; or the first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

[0404] Optionally, the first link includes N single-hop links, each of the N single-hop links corresponds to an identifier, and the identifier corresponding to each single-hop link is configured by a terminal device associated with each single-hop link, and N is a positive integer greater than or equal to 2.

[0405] Optionally, the first link includes M relay terminal devices, each of the M relay terminal devices is associated with two single-hop links on the first link, and each relay terminal device is used to configure identifiers for the two single-hop links associated with each relay terminal device, where M is a positive integer greater than or equal to 2.

[0406] Optionally, the first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link, the second identifier is associated with the first transmission direction of the first single-hop link, and the third identifier is associated with the second transmission direction of the first single-hop link.

[0407] Optionally, the first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link; for the first relay terminal device, the first single-hop link transmits data based on the mapping relationship between the second identifier and the third identifier and the second identifier; for the second relay terminal device, the first single-hop link transmits data based on the mapping relationship between the second identifier and the third identifier and the third identifier.

[0408] Optionally, the first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, and the first single-hop link transmits data based on an identifier configured by the first relay terminal device.

[0409] Optionally, the first relay terminal device sends the identifier of the first single-hop link earlier than the second relay terminal device sends the identifier of the first single-hop link; or, the first relay terminal device sends assistance information earlier than the second relay terminal device sends assistance information, and the assistance information is used to determine the identifier corresponding to the first single-hop link; or, the terminal device capability of the first relay terminal device is higher than the terminal device capability of the second relay terminal device; or, the first relay terminal device and the second relay terminal device negotiate to determine that the identifier of the first single-hop link is configured by the first relay terminal device; or, the connection establishment request for establishing the first single-hop link is initiated by the first relay terminal device.

[0410] Optionally, the first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link, and the first single-hop link transmits data based on a target identifier among the second identifier and the third identifier.

[0411] Optionally, the target identifier is the identifier with the smaller value between the second identifier and the third identifier; or, the target identifier is the identifier with the larger value between the second identifier and the third identifier.

[0412] Optionally, the first identifier is used to identify two single-hop links on the first link that are associated with a first relay terminal device, and the first device is the first relay terminal device; or

[0413] The first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

[0414] Optionally, the first identifier is carried by a first message, and the first message is a PC5-RRC message or a PC5-S message.

[0415] Optionally, the first message is a PC5-RRC message, the first message includes configuration information of the SRAP layer, and the configuration information includes the first identifier.

[0416] Optionally, before the first device sends the first identifier configured by the first device to the first terminal device, the first link sends or receives signaling based on a fourth identifier transmission, and the fourth identifier is one of the following: a default identifier; an identifier determined based on protocol predefined information; and an identifier determined based on the first mapping relationship.

[0417] Optionally, the first mapping relationship includes one or more of the following: a mapping relationship between a service and the fourth identifier; a mapping relationship between a service identifier and the fourth identifier; a mapping relationship between a relay service code and the fourth identifier; and a mapping relationship between a layer 2 identifier of a terminal device and the fourth identifier.

[0418] Optionally, the communication device further includes: a receiving module 3320, configured to receive first assistance information sent by the first terminal device, where the first assistance information is used to determine the first identifier.

[0419] Optionally, the sending of the first assistance information is triggered based on a first condition, and the first condition includes one or more of the following: the first terminal device receives a request for assistance information; the first terminal device receives a data packet containing a new identifier or an unknown identifier; the first terminal device establishes a new side link based on a relay terminal device; there is a conflict in the configured identifier of the first terminal device; and the first terminal device receives second assistance information sent by other terminal devices, and the second assistance information is used to determine the identifier associated with the first link.

[0420] Optionally, the first assistance information includes one or more of the following: a configured identifier of the first terminal device; the position of the first terminal device on the first link; a layer 2 identifier of the first terminal device; a layer 2 identifier of the previous-hop terminal device of the first terminal device; a layer 2 identifier of the next-hop terminal device of the first terminal device; and information indicating that the first terminal device is a relay terminal device or an end terminal device.

[0421] Optionally, the first assistance information is sent directly from the first terminal device to the first device; or, the first assistance information is sent from the first terminal device to the first device via a second terminal device; wherein the second terminal device is associated with the first terminal device via a single-hop link.

[0422] Optionally, the first identifier is sent directly by the first device to the first terminal device; or, the first identifier is sent by the first device to the first terminal device via a second terminal device; wherein the second terminal device is associated with the first terminal device via a single-hop link.

[0423] Optionally, the first identifier is configured after the first device receives assistance information sent by each terminal device on the first link, wherein the first device is an external device of the first link; or, the first identifier is configured after the first device receives assistance information sent by each terminal device on the first link other than the first device, wherein the first device is a terminal device on the first link; or, the first identifier is configured after the first device receives assistance information sent by at least one terminal device on the first link; or, the first identifier is configured after a first time has passed since the sending of the request information, wherein the request information is used to request assistance information; or the first identifier is configured after a second time has passed since the connection of the first link was established; or the configuration of the first identifier is not related to whether the assistance information is received; wherein the assistance information is used to determine the identifier associated with the first link.

[0424] Figure 34 is a schematic block diagram of a communication device according to an embodiment of the present application. The dashed lines in Figure 34 indicate that the unit or module is optional. The device 3400 may be used to implement the method described in the above method embodiment. The device 3400 may be a chip, a terminal device, or a network device.

[0425] The device 3400 may include one or more processors 3410. The processor 3410 may support the device 3400 to implement the method described in the method embodiment above. The processor 3410 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0426] The apparatus 3400 may further include one or more memories 3420. The memories 3420 store programs that can be executed by the processor 3410, causing the processor 3410 to perform the methods described in the above method embodiments. The memories 3420 may be independent of the processor 3410 or integrated into the processor 3410.

[0427] The apparatus 3400 may further include a transceiver 3430. The processor 3410 may communicate with other devices or chips via the transceiver 3430. For example, the processor 3410 may transmit and receive data with other devices or chips via the transceiver 3430.

[0428] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal device or network device provided in the present application, and the program enables a computer to execute the method performed by the terminal device or network device in each embodiment of the present application.

[0429] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal device or network device provided in the present application, and the program causes a computer to execute the method performed by the terminal device or network device in each embodiment of the present application.

[0430] The present application also provides a computer program that can be applied to a terminal device or network device provided in the present application, and enables a computer to execute the method performed by the terminal device or network device in each embodiment of the present application.

[0431] It should be understood that the terms "system" and "network" in this application can be used interchangeably. In addition, the terms used in this application are only used to explain the specific embodiments of this application and are not intended to limit this application. The terms "first", "second", "third", and "fourth" in the specification and claims of this application and the accompanying drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0432] In the embodiments of this application, the term "indication" may refer to a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" may refer to a direct indication of B, e.g., B can obtain information through A; it may refer to an indirect indication of B, e.g., A indicates C, e.g., B can obtain information through C; or it may refer to an association between A and B.

[0433] In the embodiment of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0434] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and indication, configuration and configuration, etc.

[0435] In the embodiments of this application, the term "include" can refer to direct inclusion or indirect inclusion. Alternatively, the term "include" in the embodiments of this application can be replaced with "indicates" or "is used to determine." For example, "A includes B" can be replaced with "A indicates B" or "A is used to determine B."

[0436] In the embodiments of the present application, "pre-definition" or "pre-configuration" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device and a network device). The present application does not limit the specific implementation method. For example, pre-definition may refer to information defined in a protocol.

[0437] In the embodiments of the present application, the “protocol” may refer to a standard protocol in the communications field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0438] In the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0439] In various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean 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 the present application.

[0440] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0441] The units described as separate components may or may not be physically separate, and 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 these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0442] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0443] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it 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. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. 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 computer-readable storage medium. 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 a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0444] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A wireless communication method, characterized in that: include: The first terminal device receives a first identifier configured by the first device, where the first identifier is used to transmit data on the first link; The first link is a side link, and the first link passes through multiple relay terminal devices.

2. The method according to claim 1, characterized in that The first identifier is used to identify one of the following: the first link; a single-hop link on the first link; A plurality of single-hop links on the first link; and A terminal device on the first link.

3. The method according to claim 2, characterized in that The first identifier includes a terminal device identifier of an end terminal device on the first link, and the first link is determined based on the terminal device identifiers of two end terminal devices on the first link.

4. The method according to any one of claims 1 to 3, characterized in that The first device is one of the following: An end terminal device on the first link; The target relay terminal device on the first link; and The external device of the first link.

5. The method according to claim 4, characterized in that The target relay terminal device is determined based on one or more of the following: The number of relay hops between the relay terminal device and the end terminal device on the first link; The first indication information sent by the upper layer; terminal device capabilities of the relay terminal device on the first link; Whether the relay terminal device on the first link is within the coverage of the network device; and The position of the relay terminal device on the first link in the first link.

6. The method according to claim 4 or 5, characterized in that: The target relay terminal device is one or more of the following: A relay terminal device on the first link having the least number of relay hops from the end terminal device; The terminal device indicated by the first indication information sent by the upper layer; A relay terminal device on the first link that is within the coverage of the network device; and A relay terminal device at the center of the first link.

7. The method according to any one of claims 4 to 6, characterized in that: The external device is one of the following: A serving terminal device of the terminal device on the first link; and Network equipment.

8. The method according to any one of claims 1 to 3, characterized in that The first identifier is used to identify a first single-hop link on the first link, the first single-hop link is associated with the first terminal device and the second terminal device, and the first device is the second terminal device; or The first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

9. The method according to claim 8, characterized in that The first link includes N single-hop links, each of the N single-hop links corresponds to an identifier, and the identifier corresponding to each single-hop link is configured by a terminal device associated with each single-hop link, and N is a positive integer greater than or equal to 2.

10. The method according to claim 8, characterized in that The first link includes M relay terminal devices, each of the M relay terminal devices is associated with two single-hop links on the first link, and each relay terminal device is used to configure identifiers for the two single-hop links associated with each relay terminal device, and M is a positive integer greater than or equal to 2.

11. The method according to claim 10, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link, the second identifier is associated with a first transmission direction of the first single-hop link, and the third identifier is associated with a second transmission direction of the first single-hop link.

12. The method according to claim 10, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device configures a second identifier for the first single-hop link, and the second relay terminal device configures a third identifier for the first single-hop link; For the first relay terminal device, the first single-hop link performs data transmission based on the mapping relationship between the second identifier and the third identifier and the second identifier; For the second relay terminal device, the first single-hop link is based on the mapping relationship between the second identifier and the third identifier. The system and the third identifier are used for data transmission.

13. The method according to claim 10, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, and the first single-hop link performs data transmission based on an identifier configured by the first relay terminal device.

14. The method according to claim 13, characterized in that: The time at which the first relay terminal device sends the identifier of the first single-hop link is earlier than the time at which the second relay terminal device sends the identifier of the first single-hop link; or, The first relay terminal device sends the assistance information earlier than the second relay terminal device sends the assistance information, and the assistance information is used to determine the identifier corresponding to the first single-hop link; or The terminal device capability of the first relay terminal device is higher than the terminal device capability of the second relay terminal device; or, The first relay terminal device and the second relay terminal device negotiate to determine that the first relay terminal device configures an identifier of the first single-hop link; or, The connection establishment request for establishing the first single-hop link is initiated by the first relay terminal device.

15. The method according to claim 10, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device configures a second identifier for the first single-hop link, the second relay terminal device configures a third identifier for the first single-hop link, and the first single-hop link transmits data based on a target identifier among the second identifier and the third identifier.

16. The method according to claim 15, characterized in that: The target identifier is an identifier with a smaller value between the second identifier and the third identifier; or The target identifier is the identifier with the larger value between the second identifier and the third identifier.

17. The method according to any one of claims 1 to 3, characterized in that: The first identifier is used to identify two single-hop links on the first link that are associated with a first relay terminal device, and the first device is the first relay terminal device; or The first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

18. The method according to any one of claims 1 to 17, characterized in that The first identifier is carried by a first message, and the first message is a PC5-RRC message or a PC5-S message.

19. The method according to claim 18, characterized in that The first message is a PC5-RRC message, the first message includes configuration information of the SRAP layer, and the configuration information includes the first identifier.

20. The method according to any one of claims 1 to 19, characterized in that Before the first terminal device receives the first identifier configured by the first device, the method further includes: The first terminal device sends or receives signaling on the first link based on the fourth identifier; The fourth identifier is one of the following: Default logo; An identifier determined based on information predefined in the protocol; and The identifier is determined based on the first mapping relationship.

21. The method according to claim 20, characterized in that The first mapping relationship includes one or more of the following: A mapping relationship between the service and the fourth identifier; A mapping relationship between the service identifier and the fourth identifier; A mapping relationship between the relay service code and the fourth identifier; as well as The mapping relationship between the layer 2 identifier of the terminal device and the fourth identifier.

22. The method according to any one of claims 1 to 21, characterized in that Before the first terminal device receives the first identifier configured by the first device, the method further includes: The first terminal device sends first assistance information to the first device, where the first assistance information is used to determine the first identifier.

23. The method according to claim 22, characterized in that The sending of the first assistance information is triggered based on a first condition, where the first condition includes one or more of the following: The first terminal device receives request information for assistance information; The first terminal device receives a data packet including a new identifier or an unknown identifier; The first terminal device establishes a new sidelink based on the relay terminal device; There is a conflict in the configured identifiers of the first terminal device; as well as The first terminal device receives second assistance information sent by other terminal devices, where the second assistance information is used to determine an identifier associated with the first link.

24. The method according to claim 22 or 23, characterized in that The first assistance information includes one or more of the following: a configured identifier of the first terminal device; The position of the first terminal device on the first link; a layer 2 identifier of the first terminal device; A layer 2 identifier of a previous-hop terminal device of the first terminal device; A layer 2 identifier of a next-hop terminal device of the first terminal device; as well as Information indicating that the first terminal device is a relay terminal device or an end terminal device.

25. The method according to any one of claims 22 to 24, characterized in that: The first assistance information is sent directly from the first terminal device to the first device; or, The first assistance information is sent by the first terminal device to the first device via the second terminal device; The second terminal device is associated with the first terminal device via a single-hop link.

26. The method according to any one of claims 1 to 25, characterized in that: The first identifier is sent directly by the first device to the first terminal device; or, The first identifier is sent by the first device to the first terminal device via the second terminal device; The second terminal device is associated with the first terminal device via a single-hop link.

27. The method according to any one of claims 1 to 26, characterized in that The method further comprises: The first terminal device sends or receives a first data packet, where the first data packet is a data packet of the SRAP layer and includes the first identifier.

28. The method according to claim 27, characterized in that The first terminal device is associated with a second single-hop link and a third single-hop link, the first identifier is used to identify the second single-hop link, and the first data packet is a data packet transmitted via the second single-hop link. The method further comprises: After the first terminal device replaces the first identifier with the fifth identifier, the first terminal device forwards the first data packet through the third single-hop link; wherein the fifth identifier is used to identify the third single-hop link.

29. A method of wireless communication, characterized in that: include: A first device sends a first identifier configured by the first device to a first terminal device, where the first identifier is used to transmit data on a first link; wherein the first link is a sidelink and passes through multiple relay terminal devices.

30. The method according to claim 29, characterized in that The first identifier is used to identify one of the following: the first link; a single-hop link on the first link; A plurality of single-hop links on the first link; and A terminal device on the first link.

31. The method according to claim 30, characterized in that The first identifier includes a terminal device identifier of an end terminal device on the first link, and the first link is determined based on the terminal device identifiers of two end terminal devices of the first link.

32. The method according to any one of claims 29 to 31, characterized in that The first device is one of the following: An end terminal device on the first link; The target relay terminal device on the first link; and The external device of the first link.

33. The method according to claim 32, characterized in that The target relay terminal device is determined based on one or more of the following: The number of relay hops between the relay terminal device and the end terminal device on the first link; The first indication information sent by the upper layer; terminal device capabilities of the relay terminal device on the first link; Whether the relay terminal device on the first link is within the coverage of the network device; and The position of the relay terminal device on the first link in the first link.

34. The method according to claim 32 or 33, characterized in that The target relay terminal device is one or more of the following: A relay terminal device on the first link having the least number of relay hops from the end terminal device; The terminal device indicated by the first indication information sent by the upper layer; A relay terminal device on the first link that is within the coverage of the network device; and A relay terminal device at the center of the first link.

35. The method according to any one of claims 32 to 34, characterized in that The external device is one of the following: A serving terminal device of the terminal device on the first link; and Network equipment.

36. The method according to any one of claims 29 to 31, characterized in that The first identifier is used to identify a first single-hop link on the first link, the first single-hop link is associated with the first terminal device and the second terminal device, and the first device is the second terminal device; or The first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

37. The method according to claim 36, characterized in that The first link includes N single-hop links, each of the N single-hop links corresponds to an identifier, and the identifier corresponding to each single-hop link is configured by a terminal device associated with each single-hop link, and N is a positive integer greater than or equal to 2.

38. The method according to claim 36, characterized in that The first link includes M relay terminal devices, each of the M relay terminal devices is associated with two single-hop links on the first link, and each relay terminal device is used to configure identifiers for the two single-hop links associated with each relay terminal device, and M is a positive integer greater than or equal to 2.

39. The method according to claim 38, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link, the second identifier is associated with a first transmission direction of the first single-hop link, and the third identifier is associated with a second transmission direction of the first single-hop link.

40. The method according to claim 38, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device configures a second identifier for the first single-hop link, and the second relay terminal device configures a third identifier for the first single-hop link; For the first relay terminal device, the first single-hop link performs data transmission based on the mapping relationship between the second identifier and the third identifier and the second identifier; For the second relay terminal device, the first single-hop link transmits data based on the mapping relationship between the second identifier and the third identifier and the third identifier.

41. The method according to claim 38, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, and the first single-hop link performs data transmission based on an identifier configured by the first relay terminal device.

42. The method according to claim 41, characterized in that: The time at which the first relay terminal device sends the identifier of the first single-hop link is earlier than the time at which the second relay terminal device sends the identifier of the first single-hop link; or, The first relay terminal device sends the assistance information earlier than the second relay terminal device sends the assistance information, and the assistance information is used to determine the identifier corresponding to the first single-hop link; or The terminal device capability of the first relay terminal device is higher than the terminal device capability of the second relay terminal device; or, The first relay terminal device and the second relay terminal device negotiate to determine that the first relay terminal device configures an identifier of the first single-hop link; or, The connection establishment request for establishing the first single-hop link is initiated by the first relay terminal device.

43. The method according to claim 38, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device configures a second identifier for the first single-hop link, the second relay terminal device configures a third identifier for the first single-hop link, and the first single-hop link transmits data based on a target identifier among the second identifier and the third identifier.

44. The method according to claim 43, characterized in that: The target identifier is an identifier with a smaller value between the second identifier and the third identifier; or The target identifier is the identifier with the larger value between the second identifier and the third identifier.

45. The method according to any one of claims 29 to 31, characterized in that The first identifier is used to identify two single-hop links on the first link that are associated with a first relay terminal device, and the first device is the first relay terminal device; or The first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

46. ​​The method according to any one of claims 29 to 45, characterized in that The first identifier is carried by a first message, and the first message is a PC5-RRC message or a PC5-S message.

47. The method according to claim 46, characterized in that The first message is a PC5-RRC message, the first message includes configuration information of the SRAP layer, and the configuration information includes the first identifier.

48. The method according to any one of claims 29 to 47, characterized in that Before the first device sends the first identifier configured by the first device to the first terminal device, the first link sends or receives signaling based on the fourth identifier transmission, and the fourth identifier is one of the following: Default logo; An identifier determined based on information predefined in the protocol; and The identifier is determined based on the first mapping relationship.

49. The method according to claim 48, characterized in that The first mapping relationship includes one or more of the following: A mapping relationship between the service and the fourth identifier; A mapping relationship between the service identifier and the fourth identifier; A mapping relationship between the relay service code and the fourth identifier; as well as The mapping relationship between the layer 2 identifier of the terminal device and the fourth identifier.

50. The method according to any one of claims 29 to 49, characterized in that Before the first device sends the first identifier configured by the first device to the first terminal device, the method further includes: The first device receives first assistance information sent by the first terminal device, where the first assistance information is used to determine the first identifier.

51. The method according to claim 50, characterized in that The sending of the first assistance information is triggered based on a first condition, where the first condition includes one or more of the following: The first terminal device receives request information for assistance information; The first terminal device receives a data packet including a new identifier or an unknown identifier; The first terminal device establishes a new sidelink based on the relay terminal device; There is a conflict in the configured identifiers of the first terminal device; as well as The first terminal device receives second assistance information sent by other terminal devices, where the second assistance information is used to determine an identifier associated with the first link.

52. The method according to claim 50 or 51, characterized in that The first assistance information includes one or more of the following: a configured identifier of the first terminal device; The position of the first terminal device on the first link; a layer 2 identifier of the first terminal device; A layer 2 identifier of a previous-hop terminal device of the first terminal device; A layer 2 identifier of a next-hop terminal device of the first terminal device; as well as Information indicating that the first terminal device is a relay terminal device or an end terminal device.

53. The method according to any one of claims 50 to 52, characterized in that: The first assistance information is sent directly from the first terminal device to the first device; or, The first assistance information is sent by the first terminal device to the first device via the second terminal device; The second terminal device is associated with the first terminal device via a single-hop link.

54. The method according to any one of claims 29 to 53, characterized in that: The first identifier is sent directly by the first device to the first terminal device; or, The first identifier is sent by the first device to the first terminal device via the second terminal device; The second terminal device is associated with the first terminal device via a single-hop link.

55. The method according to any one of claims 29 to 54, characterized in that: The first identifier is configured after the first device receives assistance information sent by each terminal device on the first link, wherein the first device is an external device of the first link; or The first identifier is configured after the first device receives assistance information sent by each terminal device on the first link except the first device, wherein the first device is a terminal device on the first link; or The first identifier is configured after the first device receives assistance information sent by at least one terminal device on the first link; or, The first identifier is configured after a first duration has passed since a distance request message was sent, wherein the request message is used to request assistance information; or The first identifier is configured after a second time period has passed since the connection of the first link was established; or The configuration of the first identifier is irrelevant to whether the assistance information is received; The assistance information is used to determine an identifier associated with the first link.

56. A terminal device, characterized in that: The terminal device is a first terminal device, and the terminal device includes: A receiving module, configured to receive a first identifier configured by a first device, where the first identifier is used to transmit data on a first link; The first link is a side link, and the first link passes through multiple relay terminal devices.

57. The terminal device according to claim 56, characterized in that: The first identifier is used to identify one of the following: the first link; a single-hop link on the first link; A plurality of single-hop links on the first link; and A terminal device on the first link.

58. The terminal device according to claim 57, characterized in that: The first identifier includes a terminal device identifier of an end terminal device on the first link, and the first link is determined based on the terminal device identifiers of two end terminal devices on the first link.

59. The terminal device according to any one of claims 56-58, characterized in that: The first device is one of the following: An end terminal device on the first link; The target relay terminal device on the first link; and The external device of the first link.

60. The terminal device according to claim 59, characterized in that: The target relay terminal device is determined based on one or more of the following: The number of relay hops between the relay terminal device and the end terminal device on the first link; The first indication information sent by the upper layer; terminal device capabilities of the relay terminal device on the first link; Whether the relay terminal device on the first link is within the coverage of the network device; and The position of the relay terminal device on the first link in the first link.

61. The terminal device according to claim 59 or 60, characterized in that: The target relay terminal device is one or more of the following: A relay terminal device on the first link having the least number of relay hops from the end terminal device; The terminal device indicated by the first indication information sent by the upper layer; A relay terminal device on the first link that is within the coverage of the network device; and A relay terminal device at the center of the first link.

62. The terminal device according to any one of claims 59 to 61, characterized in that: The external device is one of the following: A serving terminal device of the terminal device on the first link; and Network equipment.

63. The terminal device according to any one of claims 56-58, characterized in that: The first identifier is used to identify a first single-hop link on the first link, the first single-hop link is associated with the first terminal device and the second terminal device, and the first device is the second terminal device; or The first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

64. The terminal device according to claim 63, characterized in that: The first link includes N single-hop links, each of the N single-hop links corresponds to an identifier, and the identifier corresponding to each single-hop link is configured by a terminal device associated with each single-hop link, and N is a positive integer greater than or equal to 2.

65. The terminal device according to claim 63, characterized in that: The first link includes M relay terminal devices, each of the M relay terminal devices is associated with two single-hop links on the first link, and each relay terminal device is used to configure identifiers for the two single-hop links associated with each relay terminal device, and M is a positive integer greater than or equal to 2.

66. The terminal device according to claim 65, characterized in that: The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link, the second identifier is associated with a first transmission direction of the first single-hop link, and the third identifier is associated with a second transmission direction of the first single-hop link.

67. The terminal device according to claim 65, characterized in that: The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device configures a second identifier for the first single-hop link, and the second relay terminal device configures a third identifier for the first single-hop link; For the first relay terminal device, the first single-hop link performs data transmission based on the mapping relationship between the second identifier and the third identifier and the second identifier; For the second relay terminal device, the first single-hop link transmits data based on the mapping relationship between the second identifier and the third identifier and the third identifier.

68. The terminal device according to claim 65, characterized in that: The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, and the first single-hop link performs data transmission based on an identifier configured by the first relay terminal device.

69. The terminal device according to claim 68, characterized in that: The time at which the first relay terminal device sends the identifier of the first single-hop link is earlier than the time at which the second relay terminal device sends the identifier of the first single-hop link; or, The first relay terminal device sends the assistance information earlier than the second relay terminal device sends the assistance information, and the assistance information is used to determine the identifier corresponding to the first single-hop link; or The terminal device capability of the first relay terminal device is higher than the terminal device capability of the second relay terminal device; or, The first relay terminal device and the second relay terminal device negotiate to determine that the first relay terminal device configures an identifier of the first single-hop link; or, The connection establishment request for establishing the first single-hop link is initiated by the first relay terminal device.

70. The terminal device according to claim 65, characterized in that: The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device configures a second identifier for the first single-hop link, the second relay terminal device configures a third identifier for the first single-hop link, and the first single-hop link transmits data based on a target identifier among the second identifier and the third identifier.

71. The terminal device according to claim 70, characterized in that: The target identifier is an identifier with a smaller value between the second identifier and the third identifier; or The target identifier is the identifier with the larger value between the second identifier and the third identifier.

72. The terminal device according to any one of claims 56-58, characterized in that: The first identifier is used to identify two single-hop links on the first link that are associated with a first relay terminal device, and the first device is the first relay terminal device; or The first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

73. The terminal device according to any one of claims 56 to 72, characterized in that: The first identifier is carried by a first message, and the first message is a PC5-RRC message or a PC5-S message.

74. The terminal device according to claim 73, characterized in that: The first message is a PC5-RRC message, the first message includes configuration information of the SRAP layer, and the configuration information includes the first identifier.

75. The terminal device according to any one of claims 56 to 74, characterized in that: The terminal device further includes: A first communication module, configured to send or receive signaling on the first link based on a fourth identifier; The fourth identifier is one of the following: Default logo; An identifier determined based on information predefined in the protocol; and The identifier is determined based on the first mapping relationship.

76. The terminal device according to claim 75, characterized in that: The first mapping relationship includes one or more of the following: A mapping relationship between the service and the fourth identifier; A mapping relationship between the service identifier and the fourth identifier; A mapping relationship between the relay service code and the fourth identifier; as well as The mapping relationship between the layer 2 identifier of the terminal device and the fourth identifier.

77. The terminal device according to any one of claims 56 to 76, characterized in that: The terminal device further includes: A sending module is used to send first assistance information to the first device, where the first assistance information is used to determine the first identifier.

78. The terminal device according to claim 77, characterized in that: The sending of the first assistance information is triggered based on a first condition, where the first condition includes one or more of the following: The first terminal device receives request information for assistance information; The first terminal device receives a data packet including a new identifier or an unknown identifier; The first terminal device establishes a new sidelink based on the relay terminal device; There is a conflict in the configured identifiers of the first terminal device; as well as The first terminal device receives second assistance information sent by other terminal devices, where the second assistance information is used to determine an identifier associated with the first link.

79. The terminal device according to claim 77 or 78, characterized in that: The first assistance information includes one or more of the following: a configured identifier of the first terminal device; The position of the first terminal device on the first link; a layer 2 identifier of the first terminal device; A layer 2 identifier of a previous-hop terminal device of the first terminal device; A layer 2 identifier of a next-hop terminal device of the first terminal device; as well as Information indicating that the first terminal device is a relay terminal device or an end terminal device.

80. The terminal device according to any one of claims 77 to 79, characterized in that: The first assistance information is sent directly from the first terminal device to the first device; or, The first assistance information is sent by the first terminal device to the first device via the second terminal device; The second terminal device is associated with the first terminal device via a single-hop link.

81. The terminal device according to any one of claims 56 to 80, characterized in that: The first identifier is sent directly by the first device to the first terminal device; or, The first identifier is sent by the first device to the first terminal device via the second terminal device; The second terminal device is associated with the first terminal device via a single-hop link.

82. The terminal device according to any one of claims 56 to 81, characterized in that: The terminal device further includes: The second communication module is used to send or receive a first data packet, where the first data packet is a data packet of the SRAP layer and includes the first identifier.

83. The terminal device according to claim 82, characterized in that: The first terminal device is associated with a second single-hop link and a third single-hop link, the first identifier is used to identify the second single-hop link, and the first data packet is a data packet transmitted via the second single-hop link. The terminal device further includes: A forwarding module, used to forward the first data packet through the third single-hop link after the first terminal device replaces the first identifier with a fifth identifier; wherein the fifth identifier is used to identify the third single-hop link.

84. A communication device, characterized in that: The communication device is a first device, and the communication device includes: A sending module is used to send a first identifier configured by the first device to a first terminal device, wherein the first identifier is used to transmit data on a first link; wherein the first link is a side link, and the first link passes through multiple relay terminal devices.

85. The communication device according to claim 84, characterized in that The first identifier is used to identify one of the following: the first link; a single-hop link on the first link; A plurality of single-hop links on the first link; and A terminal device on the first link.

86. The communication device according to claim 85, characterized in that The first identifier includes a terminal device identifier of an end terminal device on the first link, and the first link is determined based on the terminal device identifiers of two end terminal devices of the first link.

87. The communication device according to any one of claims 84 to 86, characterized in that: The first device is one of the following: An end terminal device on the first link; The target relay terminal device on the first link; and The external device of the first link.

88. The communication device according to claim 87, characterized in that The target relay terminal device is determined based on one or more of the following: The number of relay hops between the relay terminal device and the end terminal device on the first link; The first indication information sent by the upper layer; terminal device capabilities of the relay terminal device on the first link; Whether the relay terminal device on the first link is within the coverage of the network device; and The position of the relay terminal device on the first link in the first link.

89. The communication device according to claim 87 or 88, characterized in that The target relay terminal device is one or more of the following: A relay terminal device on the first link having the least number of relay hops from the end terminal device; The terminal device indicated by the first indication information sent by the upper layer; A relay terminal device on the first link that is within the coverage of the network device; and A relay terminal device at the center of the first link.

90. The communication device according to any one of claims 87 to 89, characterized in that: The external device is one of the following: A serving terminal device of the terminal device on the first link; and Network equipment.

91. The communication device according to any one of claims 84-86, characterized in that: The first identifier is used to identify a first single-hop link on the first link, the first single-hop link is associated with the first terminal device and the second terminal device, and the first device is the second terminal device; or The first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

92. The communication device according to claim 91, characterized in that The first link includes N single-hop links, each of the N single-hop links corresponds to an identifier, and the identifier corresponding to each single-hop link is configured by a terminal device associated with each single-hop link, and N is a positive integer greater than or equal to 2.

93. The communication device according to claim 91, characterized in that The first link includes M relay terminal devices, each of the M relay terminal devices is associated with two single-hop links on the first link, and each relay terminal device is used to configure identifiers for the two single-hop links associated with each relay terminal device, and M is a positive integer greater than or equal to 2.

94. The communication device according to claim 93, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device is configured with a second identifier for the first single-hop link, and the second relay terminal device is configured with a third identifier for the first single-hop link, the second identifier is associated with a first transmission direction of the first single-hop link, and the third identifier is associated with a second transmission direction of the first single-hop link.

95. The communication device according to claim 93, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device configures a second identifier for the first single-hop link, and the second relay terminal device configures a third identifier for the first single-hop link; For the first relay terminal device, the first single-hop link performs data transmission based on the mapping relationship between the second identifier and the third identifier and the second identifier; For the second relay terminal device, the first single-hop link transmits data based on the mapping relationship between the second identifier and the third identifier and the third identifier.

96. The communication device according to claim 93, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, and the first single-hop link performs data transmission based on an identifier configured by the first relay terminal device.

97. The communication device according to claim 96, characterized in that: The time at which the first relay terminal device sends the identifier of the first single-hop link is earlier than the time at which the second relay terminal device sends the identifier of the first single-hop link; or, The first relay terminal device sends the assistance information earlier than the second relay terminal device sends the assistance information, and the assistance information is used to determine the identifier corresponding to the first single-hop link; or The terminal device capability of the first relay terminal device is higher than the terminal device capability of the second relay terminal device; or, The first relay terminal device and the second relay terminal device negotiate to determine that the first relay terminal device configures an identifier of the first single-hop link; or, The connection establishment request for establishing the first single-hop link is initiated by the first relay terminal device.

98. The communication device according to claim 93, characterized in that The first single-hop link is located between a first relay terminal device and a second relay terminal device on the first link, the first relay terminal device configures a second identifier for the first single-hop link, the second relay terminal device configures a third identifier for the first single-hop link, and the first single-hop link transmits data based on a target identifier among the second identifier and the third identifier.

99. The communication device according to claim 98, characterized in that: The target identifier is an identifier with a smaller value between the second identifier and the third identifier; or The target identifier is the identifier with the larger value between the second identifier and the third identifier.

100. The communication device according to any one of claims 84-86, characterized in that: The first identifier is used to identify two single-hop links on the first link that are associated with a first relay terminal device, and the first device is the first relay terminal device; or The first identifier includes a terminal device identifier of a terminal device on the first link, and the first link is determined based on the terminal device identifiers of each terminal device on the first link.

101. The communication device according to any one of claims 84-100, characterized in that: The first identifier is carried by a first message, and the first message is a PC5-RRC message or a PC5-S message.

102. The communication device according to claim 101, characterized in that The first message is a PC5-RRC message, the first message includes configuration information of the SRAP layer, and the configuration information includes the first identifier.

103. The communication device according to any one of claims 84-102, characterized in that: Before the first device sends the first identifier configured by the first device to the first terminal device, the first link sends or receives signaling based on the fourth identifier transmission, and the fourth identifier is one of the following: Default logo; An identifier determined based on information predefined in the protocol; and The identifier is determined based on the first mapping relationship.

104. The communication device according to claim 103, characterized in that The first mapping relationship includes one or more of the following: A mapping relationship between the service and the fourth identifier; A mapping relationship between the service identifier and the fourth identifier; A mapping relationship between the relay service code and the fourth identifier; as well as The mapping relationship between the layer 2 identifier of the terminal device and the fourth identifier.

105. The communication device according to any one of claims 84-104, characterized in that: The communication device further comprises: A receiving module is used to receive first assistance information sent by the first terminal device, where the first assistance information is used to determine the first identifier.

106. The communication device according to claim 105, characterized in that The sending of the first assistance information is triggered based on a first condition, where the first condition includes one or more of the following: The first terminal device receives request information for assistance information; The first terminal device receives a data packet including a new identifier or an unknown identifier; The first terminal device establishes a new sidelink based on the relay terminal device; There is a conflict in the configured identifiers of the first terminal device; as well as The first terminal device receives second assistance information sent by other terminal devices, where the second assistance information is used to determine an identifier associated with the first link.

107. The communication device according to claim 105 or 106, characterized in that: The first assistance information includes one or more of the following: a configured identifier of the first terminal device; The position of the first terminal device on the first link; a layer 2 identifier of the first terminal device; A layer 2 identifier of a previous-hop terminal device of the first terminal device; A layer 2 identifier of a next-hop terminal device of the first terminal device; as well as Information indicating that the first terminal device is a relay terminal device or an end terminal device.

108. The communication device according to any one of claims 105-107, characterized in that: The first assistance information is sent directly from the first terminal device to the first device; or, The first assistance information is sent by the first terminal device to the first device via the second terminal device; The second terminal device is associated with the first terminal device via a single-hop link.

109. The communication device according to any one of claims 84 to 108, characterized in that: The first identifier is sent directly by the first device to the first terminal device; or, The first identifier is sent by the first device to the first terminal device via the second terminal device; The second terminal device is associated with the first terminal device via a single-hop link.

110. The communication device according to any one of claims 84 to 109, characterized in that: The first identifier is configured after the first device receives assistance information sent by each terminal device on the first link, wherein the first device is an external device of the first link; or The first identifier is configured after the first device receives assistance information sent by each terminal device on the first link except the first device, wherein the first device is a terminal device on the first link; or The first identifier is configured after the first device receives assistance information sent by at least one terminal device on the first link; or, The first identifier is configured after a first duration has passed since a distance request message was sent, wherein the request message is used to request assistance information; or The first identifier is configured after a second time period has passed since the connection of the first link was established; or The configuration of the first identifier is irrelevant to whether the assistance information is received; The assistance information is used to determine an identifier associated with the first link.

111. A terminal device, characterized in that: The method comprises a transceiver, a memory and a processor, wherein the memory is used to store a program, and the processor is used to call the program in the memory so that the terminal device executes the method as described in any one of claims 1 to 28.

112. A communication device, characterized in that: The device comprises a transceiver, a memory and a processor, wherein the memory is used to store a program, and the processor is used to call the program in the memory so that the communication device executes the method as described in any one of claims 29-55.

113. A device, characterized in that: It comprises a processor, which is used to call a program from a memory so that the device executes the method as described in any one of claims 1-55.

114. A chip, characterized in that: It comprises a processor, which is used to call a program from a memory so that a device equipped with the chip executes a method as described in any one of claims 1 to 55.

115. A computer-readable storage medium, characterized in that: A program is stored thereon, the program causing a computer to execute the method according to any one of claims 1 to 55.

116. A computer program product, characterized in that A program is included, which causes a computer to execute the method as claimed in any one of claims 1 to 55.

117. A computer program, characterized in that The computer program causes a computer to execute the method according to any one of claims 1 to 55.

Images