A communication method and apparatus

Abstract

The present application discloses a communication method and apparatus. The method can be applied to a second terminal device and includes: receiving a first message from a first relay device; the first message includes an identifier of a first terminal device; the identifier of the first terminal device is: the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or an identifier assigned by the first relay device to the first terminal device; communicating with the first terminal device according to the identifier of the first terminal device. Thus, the second terminal device can identify, through the identifier of the first terminal device, data sent from a protocol layer below the RLC layer to the relay device or data received from the relay device, so as to determine that the source terminal device or the destination terminal device associated with the data is the first terminal device. In some relay scenarios, corresponding resources or bearer configurations can be requested for different destination terminal devices, improving communication quality.

Description

Technical Field

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

[0002] Currently, in addition to directly communicating with a terminal device, a terminal device can also communicate with a terminal device through a relay device. For example, a relay device (e.g., a relay terminal device) can act as a relay between a source terminal device (source UE) and a destination terminal device (destination UE), enabling the source terminal device (e.g., terminal device 1) to communicate with the destination terminal device (e.g., terminal device 2) through the relay device. This technology is called User Equipment to User Equipment Relay (UE to UE relay, U2U relay) technology.

[0003] Currently, in one possible way, relay transmission and reception between terminal devices can be achieved through layer 3 (L3) relay technology. At this time, relay data can be forwarded through the Internet Protocol (IP) layer, that is, the data of the source terminal device will be parsed to the IP layer by the relay device and then forwarded by the relay device to the destination terminal device. In another way, relay transmission and reception between terminal devices can be achieved through layer 2 (L2) relay technology. Relay data is forwarded below the Packet Data Convergence Protocol (PDCP) layer, that is, the data of the source terminal device will be parsed to the adaptation layer or the Radio Link Control (RLC) layer by the relay device and then forwarded by the relay device to the corresponding destination terminal device.

[0004] For a scenario where a source terminal device (e.g., terminal device 1) communicates with multiple destination terminal devices (e.g., terminal device 2, terminal device 3) through the same relay device, at this time, there may be only one unicast connection between terminal device 1 and the relay device, and the relay device establishes respective unicast connections with terminal device 2 and terminal device 3. Based on the existing technology, terminal device 1 may only be able to sense the relay device, resulting in the network where terminal device 1 is located can only allocate 2 sidelink data radio bearer (SL DRB) configurations with the same performance for terminal device 1 (for transmitting unicast data between terminal device 1 and terminal device 2, and unicast data between terminal device 1 and terminal device 3), and cannot allocate different configurations for different destination terminal devices, which may lead to a relatively low transmission quality of unicast data corresponding to different destination terminal devices. Summary of the Invention

[0005] The present application provides a communication method and apparatus for improving the unicast data transmission quality when a terminal device communicates with a relay device.

[0006] In a first aspect, the present application provides a communication method, which can be executed by a second communication device. Exemplarily, the second communication device may be a terminal device. The second communication device may be a communication device or a communication device that can support the functions required for the communication device to implement this method, such as a chip. The second communication device may be a source terminal device or a destination terminal device. The second communication device may be a sending device or a receiving device.

[0007] Taking the second terminal device as an example, the method includes: The second terminal device receives a first message from a first relay device, and the first message includes an identifier of a first terminal device; wherein, the identifier of the first terminal device is: the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or an identifier assigned by the first relay device to the first terminal device. The second terminal device communicates with the first terminal device according to the identifier of the first terminal device.

[0008] Through the above method, the second terminal device can obtain the identifier of the first terminal device. Thus, for the protocol layers above the RLC layer of the second terminal device, it can also identify the data sent from the protocol layers below the RLC layer to the relay device or the data received from the relay device through the identifier of the first terminal device, so as to determine that the source terminal device or the destination terminal device associated with the data is the first terminal device. In some relay scenarios, for example, on the same unicast connection established between the source terminal device (the second terminal device) and the relay device, multiple unicast links associating the relay device with different destination terminal devices (such as different first terminal devices) are involved. At this time, since the identifier of the first terminal device has been obtained, corresponding resources or bearer configurations can be allocated for different destination terminal devices. Thus, when the second terminal device communicates with the first terminal device according to the identifier of the first terminal device, the communication quality can be improved.

[0009] In a possible implementation, the second terminal device sends a second message to the first relay device. The second message includes an identifier of the second terminal device, wherein the identifier of the second terminal device is: the layer 2 identifier of the second terminal device, the adaptation layer identifier of the second terminal device, or an identifier assigned by the first relay device to the second terminal device.

[0010] Through the above method, the second terminal device can send the identifier of the second terminal device to the first relay device. As a result, the first relay device can obtain the identifier of the second terminal device, so that the first relay device can send the identifier of the second terminal device to the first terminal device, enabling the first terminal device to communicate with the second terminal device based on the identifier of the second terminal device through the first relay device, thereby improving the communication quality between the first terminal device and the second terminal device through the first relay device.

[0011] In a possible implementation, the first message or the second message is any one of the following: unicast connection establishment request message, unicast connection establishment acceptance message, security activation command message, security activation completion message, PC5-RRC message, PC5-S message.

[0012] Through the above method, the first message and the second message can be implemented based on different methods to improve the flexibility of sending or receiving the first message or the second message in this application.

[0013] Scenario 1, the second terminal device is the sending device.

[0014] In a possible implementation, the first protocol layer obtains first data; the first data is data sent by the second terminal device to the first terminal device through the first relay device; the first data is associated with the identifier of the second terminal device and the identifier of the first terminal device.

[0015] Through the above method, the second terminal device can obtain the first data through the first protocol layer. And since the second terminal device has obtained the identifier of the first terminal device, the first protocol layer can associate the first data with the identifier of the second terminal device and the identifier of the first terminal device. Thus, for the protocol layer above the RLC layer of the second terminal device, the receiving device of the first data can be determined as the first terminal device based on the association relationship of the first data.

[0016] In a possible implementation, the first protocol layer determines second data according to the first data; the second data is data sent by the second terminal device to the first terminal device through the first relay device; the second data is associated with the identifier of the second terminal device and the second identifier of the first relay device.

[0017] Through the above method, the second terminal device can determine the second data through the first protocol layer according to the association relationship of the first data, so that the second data can be sent to the relay device through the protocol layer below the RLC layer.

[0018] In a possible implementation, the first protocol layer is the packet data convergence protocol PDCP layer or the adaptation layer.

[0019] Through the above method, the first protocol layer can be implemented based on different protocol layers to improve the flexibility of sending the second data in this application.

[0020] Scenario 2, the second terminal device is a receiving device.

[0021] In a possible implementation, the second protocol layer obtains third data; the third data is the data that the second terminal device receives from the first terminal device through the first relay device; the third data is associated with the first identifier of the first relay device and the identifier of the second terminal device.

[0022] Through the above method, the second terminal device can obtain the third data through the second protocol layer, and since the second terminal device has obtained the identifier of the first terminal device, therefore, the second protocol layer can determine that the third data originates from the first terminal device based on the association between the first identifier of the first relay device and the identifier of the second terminal device in the third data.

[0023] In a possible implementation, the second protocol layer determines fourth data according to the third data; the fourth data is the data that the second terminal device receives from the first terminal device through the first relay device; the fourth data is associated with the identifier of the first terminal device and the identifier of the second terminal device.

[0024] Through the above method, the second terminal device can implement determining the third data as the fourth data through the second protocol layer, and the fourth data is associated with the identifier of the second terminal device and the identifier of the first terminal device. Thus, for the protocol layer above the RLC layer of the second terminal device, it can determine that the sending device of the data packet is the first terminal device based on the association relationship of the fourth data.

[0025] In a possible implementation, the second protocol layer is: the Radio Link Control (RLC) layer or the adaptation layer.

[0026] Through the above method, the second protocol layer can be implemented based on different protocol layers to improve the flexibility of receiving the third data in this application.

[0027] In a possible implementation, the second terminal device sends a first request message to the access network device, and the first request message is used to request the first radio bearer configuration information corresponding to the first terminal device; the first request message includes: first QoS information and the identifier of the first terminal device; the first QoS information is the QoS information corresponding to the first terminal device.

[0028] Through the above method, the second terminal device is the source terminal device. The second terminal device can generate a first request message according to the first message, and thus, obtain the first radio bearer configuration information allocated for the first terminal device through the first request message. Since the first radio bearer configuration information is configured based on the first QoS information and the identifier of the first terminal device, the access network device can allocate corresponding resources or bearer configurations for different destination terminal devices (the first terminal device), and thus, when the second terminal device communicates with the first terminal device according to the first radio bearer configuration information, the communication quality of the second terminal device and the first terminal device communicating through the first relay device can be improved.

[0029] A possible implementation manner is that the second terminal device receives first configuration information from the access network device; the first configuration information is the first radio bearer configuration information corresponding to the first terminal device, and the first radio bearer is used for the second terminal device to send data to the first terminal device.

[0030] Through the above method, the second terminal device can receive the first radio bearer configuration information configured by the access network device for the first terminal device, and thus, when the second terminal device communicates with the first terminal device based on the first radio bearer configuration information, the communication quality of the second terminal device and the first terminal device communicating through the first relay device can be improved.

[0031] In a second aspect, the present application provides a communication method, which can be executed by a second communication device. Exemplarily, the second communication device may be a terminal device. The second communication device may be a communication device or a communication device that can support the communication device to implement the functions required by this method, such as a chip. The second communication device may be a source terminal device or a destination terminal device. The second communication device may be a sending end device or a receiving end device. Taking the second terminal device as an example, the method includes:

[0032] The second terminal device determines a second request message; the second terminal device sends the second request message to the access network device. The second request message includes: first QoS information, a second identifier of the first relay device, and first information; the first QoS information is the QoS information corresponding to the first terminal device, the second identifier of the first relay device is used for the second terminal device to communicate with the first relay device, the first information and the first QoS information have a corresponding relationship, and the first information and the second identifier have a corresponding relationship.

[0033] Through the above method, the second terminal device can send the first QoS information, the second identifier of the first relay device, and the first information to the access network device. Since the first QoS information is the QoS information corresponding to the first terminal device and the first information has a corresponding relationship with the first QoS information, the access network device can determine that the first QoS information is used for allocating radio bearers for the first terminal device. Since the first information has a corresponding relationship with the second identifier, the access network device can determine that the radio bearer is used when the second terminal device communicates with the first terminal device through the first relay device. Therefore, even when the second terminal device does not know the identifier of the first terminal device, it can request the radio bearer configuration of the first terminal device from the access network device, improving the communication quality of the second terminal device and the first terminal device when communicating through the first relay device.

[0034] In a possible implementation, the first terminal device includes N third terminal devices, the first QoS information includes: M second QoS information, and the first information includes: N second information, where N is a positive integer and M is a positive integer greater than or equal to N; the second QoS information is the QoS information corresponding to the third terminal device, and the second information and the second QoS information have a corresponding relationship.

[0035] Through the above method, when the first terminal device includes N third terminal devices, the second terminal device can send M second QoS information corresponding to the N third terminal devices to the access network device. Thus, the access network device can configure radio bearers for the N third terminal devices respectively according to the M second QoS information and the N second information, improving the communication quality of the second terminal device and the N third terminal devices when communicating through the first relay device.

[0036] In a possible implementation, receive a second response message from the access network device, where the second response message includes: radio bearer configuration information corresponding to the first terminal device; communicate with the first terminal device through the first relay device on the radio bearer corresponding to the first terminal device.

[0037] Through the above method, the second terminal device can receive the first radio bearer configuration information configured by the access network device for the first terminal device. Thus, the second terminal device can communicate with the first terminal device based on the first radio bearer configuration information, improving the communication quality of the second terminal device and the first terminal device when communicating through the first relay device.

[0038] In a possible implementation, the radio bearer configuration information corresponding to the first terminal device includes X third radio bearer configuration information, where X is a positive integer less than or equal to N; communicate with the corresponding third terminal device through the first relay device on the third radio bearer.

[0039] Through the above method, the second terminal device can receive the X third radio bearer configuration information configured by the access network device for the N third terminal devices. Thus, the second terminal device can communicate with the N third terminal devices based on the X third radio bearer configuration information, so as to improve the communication quality of the second terminal device and the N third terminal devices communicating through the first relay device.

[0040] In a possible implementation, the first QoS information includes: a first QoS identifier, and the first QoS identifier does not correspond to the first information; the second response message further includes: the first QoS identifier and the first information.

[0041] Through the above method, the first QoS identifier in the first QoS information does not correspond to the first information. Thus, by using the first QoS identifier and the first information to correspond to the QoS information of the first terminal device, the flexibility of identifying the QoS information of the first terminal device is improved.

[0042] In a possible implementation, the first QoS information includes: a first QoS identifier, and the first QoS identifier corresponds to the first information; the second response message further includes: the first QoS identifier.

[0043] Through the above method, the first QoS identifier corresponds to the first information. Thus, it is made that the first QoS identifier corresponds to the QoS information of the first terminal device, and the complexity of identifying the QoS information of the first terminal device is improved.

[0044] In a possible implementation, the first information is one of the following: a local identifier of the adaptation layer of the first terminal device, a unique identifier of the adaptation layer of the first terminal device, an identifier of the PC5-S layer of the first terminal device, or an identifier of layer 2 of the first terminal device.

[0045] Through the above method, the first information can have multiple implementation manners, which can improve the flexibility of identifying the QoS information of the first terminal device.

[0046] In a third aspect, the present application provides a communication method, which can be executed by a first communication device. Exemplarily, the first communication device may be a relay device. The relay device may be a terminal device or a network device. The first communication device may be a communication device or a communication device capable of supporting the functions required for the communication device to implement this method, such as a chip. Hereinafter, the first communication device is taken as an example of a first relay device for explanation. The method includes: sending a first message to a second terminal device, the first message including an identifier of a first terminal device, where the identifier of the first terminal device is: the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or an identifier assigned by the first relay device to the first terminal device; the identifier of the first terminal device is used for the second terminal device to communicate with the first terminal device according to the identifier of the first terminal device. Sending a second message to the first terminal device, the second message including an identifier of the second terminal device, where the identifier of the second terminal device is: the layer 2 identifier of the second terminal device, the adaptation layer identifier of the second terminal device, or an identifier assigned by the first relay device to the second terminal device; the identifier of the second terminal device is used for the first terminal device to communicate with the second terminal device according to the identifier of the second terminal device.

[0047] Through the above method, the first relay device can send the identifier of the first terminal device to the second terminal device and send the identifier of the second terminal device to the first terminal device. Thus, when the second terminal device communicates with the first terminal device through the first relay device, for the protocol layers above the RLC layer of the second terminal device, it can identify the data packet sent from the protocol layer below the RLC layer to the relay device or receive the data from the relay device through the identifier of the first terminal device, so as to determine that the source terminal device or the destination terminal device associated with the data is the first terminal device. Thus, in some relay scenarios, for example, on the same unicast connection established between the source terminal device (the second terminal device) and the relay device, multiple unicast links associating the relay device with different destination terminal devices (for example, different first terminal devices) are established. At this time, since the identifier of the first terminal device has been obtained, corresponding resources or bearer configurations can be allocated for different destination terminal devices. Thus, when the second terminal device communicates with the first terminal device according to the identifier of the first terminal device, the communication quality can be improved.

[0048] A possible implementation is to send a third message to a second relay device; the third message includes the identifier of the first terminal device; the second relay device provides relay services for the second terminal device and the first terminal device.

[0049] Through the above method, it can be applied to a multi-hop scenario, that is, the first relay device and the second relay device provide relay services for the second terminal device and the first terminal device. At this time, the first relay device may send a third message to the second relay device, so that the second relay device can send the identifier of the first terminal device to the second terminal device.

[0050] A possible implementation is to send a fourth message to the second relay device; the fourth message includes the identifier of the second terminal device; the second relay device provides relay services for the second terminal device and the first terminal device.

[0051] Through the above method, it can be applied to a multi-hop scenario, that is, the first relay device and the second relay device provide relay services for the second terminal device and the first terminal device. At this time, the first relay device may send a fourth message to the second relay device, so that the second relay device can send the identifier of the second terminal device to the first terminal device.

[0052] A possible implementation is that the first message or the second message is any one of the following: unicast connection establishment request message, unicast connection establishment acceptance message, security activation command message, security activation completion message, PC5-RRC message, PC5-S message.

[0053] Through the above method, the flexibility of the first relay device in sending the first message or the second message in this application can be improved.

[0054] Fourthly, this application provides a communication method, which can be executed by a second communication device. Exemplarily, the second communication device may be a terminal device. The second communication device may be a communication device or a communication device that can support the functions required for the communication device to implement this method, such as a chip. The second communication device may be a source terminal device or a destination terminal device. The second communication device may be a sending-end device or a receiving-end device. Taking the second terminal device as an example, the method includes:

[0055] The second terminal device sends a third request message to the first relay device. The third request message is a PC5-RRC message, and the third request message is used to request the first relay device to establish a unicast connection with the fourth terminal device. The first terminal device and the second terminal device establish a unicast connection through the first relay device; the second terminal device receives a third response message sent by the first relay device. The third response message is a PC5-RRC message, and the third response message is used to indicate that the first relay device and the fourth terminal device have completed the unicast connection establishment.

[0056] Through the above method, the second terminal device can receive a third request message from the first terminal device via the first radio bearer, and thereby, via the first radio bearer, request to establish a unicast connection between the first relay device and the fourth terminal device to multiplex the first radio bearer and save resource overhead.

[0057] In a possible implementation, the second terminal device receives a fourth request message from the second relay device; the fourth request message is used to request the second terminal device to establish a unicast connection with the fifth terminal device via the second relay device; the fifth terminal device and the first terminal device establish a unicast connection via the second relay device; the fourth request message is a PC5-RRC message; the second terminal device sends a fourth response message via the second relay device; the fourth response message is used to indicate that the second terminal device establishes a unicast connection with the fifth terminal device via the second relay device; the fourth response message is a PC5-RRC message.

[0058] Through the above method, it can be applied to a multi-hop scenario, and the first relay device and the second relay device provide relay services for the first terminal device and the second terminal device. At this time, the second terminal device can receive a fourth request message from the second relay device via the first radio bearer, and thereby, via the first radio bearer, request to establish a unicast connection between the first relay device and the fifth terminal device to multiplex the first radio bearer and save resource overhead.

[0059] In a possible implementation, the third request message or the fourth request message includes at least one of the following: the application identifier of the second terminal device, the application layer identifier of the fifth terminal device, the service identifier, the security capability information, and the identifier of the fifth terminal device.

[0060] Through the above method, the third request message or the fourth request message can include various information, thereby enriching the applicable scenarios of the third request message or the fourth request message.

[0061] In a possible implementation, the identifier of the fifth terminal device is the layer 2 identifier of the fifth terminal device, the adaptation layer identifier of the fifth terminal device, or the identifier assigned by the first relay device to the fifth terminal device.

[0062] Through the above method, the identifier of the fifth terminal device can be determined in various ways, improving the flexibility and applicability of the identifier of the fifth terminal device.

[0063] In a possible implementation, the third request message is generated by the PC5-S layer instructing the PC5-RRC layer, and the third response message is generated by the PC5-S layer instructing the PC5-RRC layer; or, the fourth request message is generated by the PC5-S layer instructing the PC5-RRC layer, and the third response message is generated by the PC5-S layer instructing the PC5-RRC layer.

[0064] Through the above method, the third request message can be sent in multiple ways, thereby improving the flexibility of sending the third request message.

[0065] In a fifth aspect, the present application provides a communication method, which can be executed by a second communication device. Exemplarily, the second communication device can be a terminal device. The second communication device can be a communication device or a communication device capable of supporting the functions required for the communication device to implement this method, such as a chip. The second communication device can be a source terminal device or a destination terminal device. The second communication device can be a sending end device or a receiving end device. Taking the second terminal device as an example, the method includes:

[0066] Receiving a third request message from a first terminal device through a first radio bearer; the third request message is used to request a first relay device to establish a unicast connection with a fourth terminal device; the first radio bearer is a radio bearer between the first terminal device and the second terminal device; the third request message is a PC5-RRC message; sending a third response message to the first terminal device on the first radio bearer; the third response message is used to indicate that the first relay device and the fourth terminal device have completed the establishment of the unicast connection; the third response message is a PC5-RRC message.

[0067] Through the above method, the second terminal device can receive the third request message from the first terminal device through the first radio bearer, thereby, through the first radio bearer, requesting to establish a unicast connection between the first relay device and the fourth terminal device to multiplex the first radio bearer and save resource overhead.

[0068] In a possible implementation, the third request message is indicated by the PC5-S layer to the PC5-RRC layer for sending; the third response message is indicated by the PC5-S layer to the PC5-RRC layer for sending.

[0069] Through the above method, the third request message can be sent in multiple ways, thereby improving the flexibility of sending the third request message.

[0070] In a possible implementation, the third request message includes at least one of the following: an application identifier of the first terminal device, an application layer identifier of the fourth terminal device, a service identifier, security capability information, an identifier of the fourth terminal device.

[0071] Through the above method, the third request message can include multiple types of information, thereby enriching the applicable scenarios of the third request message.

[0072] In a possible implementation, the identifier of the fourth terminal device is a layer 2 identifier of the fourth terminal device, an adaptation layer identifier of the fourth terminal device, or the identifier of the fourth terminal device is an identifier assigned by the first relay device to the fourth terminal device.

[0073] Through the above method, the identifier of the fourth terminal device can be determined in various ways, improving the flexibility and applicability of the identifier of the fourth terminal device.

[0074] In a sixth aspect, the present application provides a communication device. For example, the communication device is the second communication device as described above. The second communication device is used to execute the methods in the implementation manners of the first aspect, the second aspect, the fourth aspect, or the fifth aspect. Specifically, the first communication device may include modules for executing the methods in the implementation manners of the first aspect, the second aspect, the fourth aspect, or the fifth aspect. For example, it includes a processing module, a sending module, and a receiving module.

[0075] Exemplarily, the sending module and the receiving module may be different functional modules, or may also be the same functional module, but can implement different functions (the sending module is used to implement the function of sending signals, and the receiving module is used to implement the function of receiving signals). Exemplarily, the first communication device is a communication device, or a chip or other component provided in the communication device. For example, the first communication device may be a terminal device, or a chip or other component provided in the terminal device. For example, the sending module may also be implemented by a transceiver, and the processing module may also be implemented by a processor. Or, the sending module may be implemented by a transmitter, the receiving module may be implemented by a receiver, and the transmitter and the receiver may be different functional modules, or may also be the same functional module, but can implement different functions (the transmitter is used to implement the function of sending signals, and the receiver is used to implement the function of receiving signals). If the first communication device is a communication device, the transceiver is implemented, for example, by an antenna, a feeder, a codec, etc. in the communication device. Or, if the first communication device is a chip provided in the communication device, then the transceiver (or, the transmitter and the receiver) is, for example, a communication interface in the chip (or rather, an interface circuit), and the communication interface is connected to a radio frequency transceiver component in the communication device to implement the sending and receiving of information through the radio frequency transceiver component.

[0076] In a seventh aspect, the present application provides a communication device. For example, the communication device is the first communication device as described above. The second communication device is used to execute the method in the implementation manner of the third aspect. Specifically, the first communication device may include modules for executing the method in the implementation manner of the third aspect. For example, it includes a processing module and a sending module.

[0077] Exemplarily, the first communication device may further include a receiving module. The transmitting module and the receiving module may be different functional modules, or may also be the same functional module, but can implement different functions (the transmitting module is used to implement the function of transmitting signals, and the receiving module is used to implement the function of receiving signals). Exemplarily, the first communication device is a relay device, or a chip or other component provided in the relay device. For example, the first communication device may be a network device or a terminal device, or may be a chip or other component provided in the network device or the terminal device. For example, the transmitting module may also be implemented by a transceiver, and the processing module may also be implemented by a processor. Alternatively, the transmitting module may be implemented by a transmitter, and the receiving module may be implemented by a receiver. The transmitter and the receiver may be different functional modules, or may also be the same functional module, but can implement different functions (the transmitter is used to implement the function of transmitting signals, and the receiver is used to implement the function of receiving signals). If the first communication device is a relay device, the transceiver is implemented, for example, by an antenna, a feeder, a codec, etc. in the relay device. Or, if the first communication device is a chip provided in a communication device, then the transceiver (or, the transmitter and the receiver) is, for example, a communication interface in the chip (or rather, an interface circuit), and the communication interface is connected to a radio frequency transceiver component in the communication device to implement the transmission and reception of information through the radio frequency transceiver component.

[0078] In an eighth aspect, a communication device is provided. The communication device is, for example, the second communication device as described above. The communication device includes a processor and a communication interface (or, an interface circuit). The communication interface can be used to communicate with other devices or equipment. Optionally, a memory may also be included for storing computer instructions. The processor and the memory are coupled to each other to implement the methods described in the embodiments of the first aspect, the second aspect, the fourth aspect, or the fifth aspect. Or, the second communication device may not include a memory, and the memory may be located outside the second communication device. The processor, the memory, and the communication interface are coupled to each other to implement the methods described in the embodiments of the first aspect, the second aspect, the fourth aspect, or the fifth aspect. For example, when the processor executes the computer instructions stored in the memory, the second communication device is caused to execute the methods in the embodiments of the first aspect, the second aspect, the fourth aspect, or the fifth aspect. Exemplarily, the second communication device is a communication device, or a chip or other component provided in the communication device. For example, the second communication device may be a terminal device, or may be a chip or other component provided in the terminal device.

[0079] Among them, if the second communication device is a communication equipment, the communication interface is implemented, for example, by a transceiver (or a transmitter and a receiver) in the communication equipment. For example, the transceiver is implemented by an antenna, a feeder, a codec, etc. in the communication equipment. Or, if the second communication device is a chip disposed in the communication equipment, then the communication interface is, for example, an input / output interface of the chip, such as input / output pins, etc., and the communication interface is connected to a radio frequency transceiver component in the communication equipment to implement information transmission and reception through the radio frequency transceiver component.

[0080] In a ninth aspect, a communication device is provided. The communication device is, for example, the first communication device as described above. The communication device includes a processor and a communication interface (or an interface circuit), and the communication interface can be used to communicate with other devices or equipment. Optionally, a memory may also be included for storing computer instructions. The processor and the memory are coupled to each other to implement the method described in the implementation manner of the third aspect above. Or, the first communication device may not include a memory, and the memory may be located outside the first communication device. The processor, the memory, and the communication interface are coupled to each other to implement the method described in the implementation manner of the third aspect above. For example, when the processor executes the computer instructions stored in the memory, the first communication device is caused to execute the method in the implementation manner of the third aspect above. Exemplarily, the communication equipment is a relay equipment. For example, the first communication device may be a relay equipment, or may be a chip or other component disposed in the relay equipment. Exemplarily, the first communication device is a communication equipment, or is a chip or other component disposed in the communication equipment. Among them, if the first communication device is a communication equipment, the communication interface is implemented, for example, by a transceiver (or a transmitter and a receiver) in the communication equipment. For example, the transceiver is implemented by an antenna, a feeder, a codec, etc. in the communication equipment. Or, if the first communication device is a chip disposed in the communication equipment, then the communication interface is, for example, an input / output interface of the chip, such as input / output pins, etc., and the communication interface is connected to a radio frequency transceiver component in the communication equipment to implement information transmission and reception through the radio frequency transceiver component.

[0081] In a tenth aspect, a chip is provided. The chip includes a processor and a communication interface, and the processor is coupled to the communication interface to implement the method provided in the implementation manner of the first aspect, the second aspect, the fourth aspect, or the fifth aspect above.

[0082] Optionally, the chip may further include a memory. For example, the processor can read and execute the software program stored in the memory to implement the method provided in the implementation manner of the first aspect, the second aspect, the fourth aspect, or the fifth aspect above. Or, the memory may not be included in the chip, but is located outside the chip. Equivalently, the processor can read and execute the software program stored in the external memory to implement the method provided in the implementation manner of the first aspect, the second aspect, the fourth aspect, or the fifth aspect above.

[0083] In an eleventh aspect, a chip is provided, which includes a processor and a communication interface. The processor is coupled to the communication interface and is used to implement the method provided by the implementation manner of the third aspect above.

[0084] Optionally, the chip may further include a memory. For example, the processor can read and execute the software program stored in the memory to implement the method provided by the implementation manner of the third aspect above. Alternatively, the memory may not be included in the chip but located outside the chip. That is, the processor can read and execute the software program stored in the external memory to implement the method provided by the implementation manner of the third aspect or the fourth aspect above.

[0085] In a twelfth aspect, a communication system is provided, which includes the communication device of the sixth aspect or the communication device of the eighth aspect, and includes the communication device of the seventh aspect or the communication device of the ninth aspect.

[0086] In a thirteenth aspect, a computer-readable storage medium is provided, which is used to store a computer program. When the computer program runs on a computer, the computer is enabled to execute the method in the implementation manner of the first aspect, the second aspect, the fourth aspect or the fifth aspect above.

[0087] In a fourteenth aspect, a computer-readable storage medium is provided, which is used to store a computer program. When the computer program runs on a computer, the computer is enabled to execute the method in the implementation manner of the third aspect above.

[0088] In a fifteenth aspect, a computer program product containing instructions is provided. The computer program product is used to store a computer program. When the computer program runs on a computer, the computer is enabled to execute the method in the implementation manner of the first aspect, the second aspect, the fourth aspect or the fifth aspect above.

[0089] In a sixteenth aspect, a computer program product containing instructions is provided. The computer program product is used to store a computer program. When the computer program runs on a computer, the computer is enabled to execute the method in the implementation manner of the third aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1a A schematic diagram of an application scenario of a communication method provided by an embodiment of the present application;

[0091] Figures 1b - 1d A schematic diagram of the system architecture of a communication method provided by an embodiment of the present application;

[0092] Figure 2 A schematic flowchart of a unicast connection establishment method provided by an embodiment of the present application;

[0093] Figure 3 A schematic diagram of a protocol stack provided by an embodiment of the present application;

[0094] Figure 4 A schematic flowchart of a method for establishing a unicast connection provided by an embodiment of the present application;

[0095] Figure 5 A schematic flowchart of a communication method provided by an embodiment of the present application;

[0096] Figure 6 A schematic flowchart of a communication method provided by an embodiment of the present application;

[0097] Figure 7 A schematic flowchart of a communication method provided by an embodiment of the present application;

[0098] Figure 8 A schematic flowchart of a communication method provided by an embodiment of the present application;

[0099] Figure 9 A schematic flowchart of a communication method provided by an embodiment of the present application;

[0100] Figure 10 A schematic flowchart of a communication method provided by an embodiment of the present application;

[0101] Figure 11 A schematic flowchart of a communication method provided by an embodiment of the present application;

[0102] Figure 12 A schematic diagram of a protocol stack provided by an embodiment of the present application;

[0103] Figure 13 A schematic flowchart of a communication method provided by an embodiment of the present application;

[0104] Figure 14 A schematic diagram of the structure of a second communication device provided by an embodiment of the present application;

[0105] Figure 15 A schematic diagram of the structure of a communication device provided by an embodiment of the present application. Detailed implementation manners

[0106] Hereinafter, some terms in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0107] 1) Vehicle-to-Everything (V2X) refers to providing vehicle information through sensors, in-vehicle terminals, etc. installed on vehicles, and enabling mutual communication between vehicles, between vehicles and people, between vehicles and roadside infrastructure, and between vehicles and the network through various communication technologies.

[0108] The solution provided by the embodiments of this application is introduced by taking the application to the V2X scenario as an example. Figure 1a A schematic diagram of the V2X communication architecture 100 is shown. As Figure 1a shown, the V2X communication architecture 100 includes: V2X devices (such as Figure 1a the V2X UE 1 and V2X UE 2 shown therein) and network devices. The V2X communication architecture 100 may also include a V2X application server. There are two communication interfaces in this V2X communication architecture, namely the PC5 interface and the Uu interface. Among them, the PC5 interface is a direct communication interface between V2X UEs, and the direct communication link between V2X UEs is also defined as a sidelink or side chain (SL). Uu interface communication is that the sending V2X UE (for example, V2X UE 1) sends V2X data through the Uu interface to the network device, and after being sent to the V2X application server for processing by the network device, it is then sent by the V2X application server to the network device and sent by the network device to the receiving V2X UE (for example, V2X UE 2). In the Uu interface communication mode, the network device that forwards the uplink data of the sending V2X UE to the application server and the network device that forwards the downlink data sent by the application server to the receiving V2X UE may be the same network device or different network devices, which can be specifically determined by the application server. It should be understood that the sending of the sending V2X UE to the network device is called uplink (UL) transmission, which is represented by Uu UL in Figure 1a ; the sending of the network device to the receiving V2X UE is called downlink (DL) transmission, which is represented by Uu DL in Figure 1a .

[0109] The technical solution provided by this application can be applied to the device-to-device (D2D) scenario. Optionally, it can be applied to the vehicle-to-everything (V2X) scenario. Exemplarily, D2D can be D2D in a long term evolution (LTE) communication system, D2D in a new radio (NR) communication system, or D2D in other communication systems that may emerge with the development of technology. R12 D2D mainly targets public safety and includes two parts: D2D communication and D2D discovery. R12 D2D communication targets public safety and only supports multicast communication (one-to-many D2D communication); R12 D2D discovery supports simple commercial broadcasts (such as advertising broadcasts, etc.). Similarly, V2X can be LTE V2X, NR V2X, or V2X in other communication systems that may emerge with the development of technology.

[0110] 2) The terminal device in the embodiments of the present application may include a device that provides voice and / or data connectivity to the user. Specifically, it includes a device that provides voice to the user, or a device that provides data connectivity to the user, or a device that provides both voice and data connectivity to the user. The terminal device may also be referred to as a user equipment (UE), a mobile station (MS), a mobile terminal (MT), etc. It is a device that provides voice or data connectivity to the user and may also be an Internet of Things device. For example, the terminal device includes handheld devices, in-vehicle devices, etc. with wireless connection capabilities. The terminal device may be: a mobile phone, a tablet computer, a laptop computer, a handheld computer, a mobile internet device (MID), a wearable device (such as a smart watch, a smart bracelet, a pedometer, etc.), an in-vehicle device (such as a car, a bicycle, an electric vehicle, an airplane, a ship, a train, a high-speed train, etc.), a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a smart home device (such as a refrigerator, a TV, an air conditioner, an electric meter, etc.), a smart robot, a workshop device, 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, or a wireless terminal in a smart home, a flying device (such as a smart robot, a hot air balloon, a drone, an airplane), etc. The terminal may also be other devices with terminal functions. For example, the terminal may also be a device that serves as a terminal function in D2D communication or vehicle-to-everything communication. By way of example and not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. And for the various terminal devices introduced above, if they are located on a vehicle (such as placed inside or installed inside a vehicle), they can all be considered in-vehicle terminal devices. In-vehicle terminal devices are also referred to as on-board units (OBUs) for example.

[0111] In the embodiments of the present application, the terminal device may also include a relay. Or it can be understood that anything that can communicate data with a base station can be regarded as a terminal device.

[0112] In the embodiments of the present application, the device for implementing the functions of the terminal device may be the terminal device or a device capable of supporting the terminal device to implement such functions, such as a chip system, which may be installed in the terminal device. In the embodiments of the present application, the chip system may be composed of chips or may include chips and other discrete devices. In the technical solutions provided in the embodiments of the present application, taking the device for implementing the functions of the terminal as the terminal device as an example, the technical solutions provided in the embodiments of the present application are described. For example, the terminal device in the embodiments of the present application may also refer to the chips in the terminal device, communication devices, units or modules having D2D or V2X communication functions, such as vehicle-mounted communication devices, vehicle-mounted communication modules or vehicle-mounted communication chips, etc.

[0113] 3) A network device, such as including an access network (AN) device, such as a base station (for example, an access point), may refer to a device in the access network that communicates with a wireless terminal device through one or more cells over the air interface. Or, for example, a network device in a V2X technology is a roadside unit (RSU). The base station can be used to mutually convert the received air frames and IP packets and serve as a router between the terminal device and the rest of the access network, where the rest of the access network may include an IP network. The RSU can be a fixed infrastructure entity supporting V2X applications and can exchange messages with other entities supporting V2X applications. The network device can also coordinate the attribute management of the air interface. For example, the network device may include an evolved Node B (NodeB or eNB or e-NodeB, evolutional Node B) in an LTE system or a long term evolution-advanced (LTE-A) system, or may also include a next generation Node B (gNB) in a 5G new radio (NR) system (also simply referred to as the NR system), or may also include a centralized unit (CU) and a distributed unit (DU) in a cloud radio access network (Cloud RAN) system. The embodiments of the present application do not limit this.

[0114] The network device may also include a core network device. However, since the embodiments of the present application mainly relate to access network devices, hereinafter, unless otherwise specified, the network devices mentioned may all refer to access network devices.

[0115] In the embodiments of this application, the device for implementing the functions of a network device may be the network device itself or a device capable of supporting the network device to implement such functions, such as a chip system. This device may be installed in the network device. In the technical solutions provided in the embodiments of this application, taking the device for implementing the functions of a network device as the network device itself as an example, the technical solutions provided in the embodiments of this application are described.

[0116] 4) Access (AS) layer:

[0117] The AS layer of the terminal device may include one or more of the radio resource control (RRC) layer, service data adaptation protocol (SDAP) layer, packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, and media access control (MAC) layer. Optionally, the access layer may further include the physical (PHY) layer.

[0118] The upper layer of the AS layer may refer to the layer above the AS layer of the terminal device, such as the V2X layer, application layer, or the layer between the V2X layer and the application layer.

[0119] 5) Process of establishing a unicast connection for SL communication:

[0120] In NR V2X R16, SL communication supports three communication modes: unicast, multicast, and broadcast. For unicast communication, a PC5-S connection needs to be established between two terminal devices. The PC5-S connection can also be referred to as a PC5 unicast link or unicast connection. The PC5-S connection can be regarded as a connection of the upper layer of the terminal device. The connection of the AS layer can be regarded as a PC5-RRC connection. When the upper-layer PC5-S connection is established, the corresponding PC5-RRC connection of the AS layer is also considered established. In practical applications, there is no need for an additional explicit PC5-RRC connection establishment process. After the PC5-S connection is established, the PC5-RRC message can be directly transmitted using the protocol-predefined sidelink singaling radio bearer (SL-SRB). Specifically, the unicast connection establishment process is as follows Figure 2As shown. The two terminal devices that need to establish a unicast connection are represented by UE1 and UE2. Message 1 is the PC5-S connection establishment request (Direct Communication Request) message sent by UE2 to UE1; Message 2 is the security activation command (Direct Security Mode Command) message sent by UE1 to UE2; Message 3 is the security activation completion (Direct Security Mode Complete) message fed back by UE2 to UE1; Message 4 is the PC5-S connection establishment acceptance (Direct Communication Accept) message fed back by UE1 to UE2. During the establishment of the PC5-S connection, the corresponding security will also be established.

[0121] After the upper layer of the terminal device completes the establishment of the PC5-S connection, the terminal device will allocate a PC5 connection identifier (PC5 link identifier) that is unique within the terminal device for each unicast connection. The upper layer of the terminal device will provide the AS layer with the unicast link profile information associated with each unicast connection. Specifically, the unicast link profile includes one or more of the following information: V2X service type; application layer ID and layer 2 ID of the source terminal device; application layer ID and layer 2 ID of the destination terminal device; network layer protocol corresponding to the unicast connection; a set of PC5 QoS flow indicators (PC5 QoS flow indicator, PFIs) associated with each V2X service type, and each PFI is associated with a set of QoS parameters. The V2X service type may include a provider service identifier (PSID) or an intelligent transportation system application identifier (ITS application identifier, ITS-AID).

[0122] 6) Sidelink Radio Bearer (SLRB): A bearer in Layer 2 for transmitting and receiving sidelink data. The SLRB may include SL-SRB and sidelink data radio bearer (SL-DRB). The SLRB includes one or more of a Packet Data Convergence Protocol (PDCP) entity, a Radio Link Control (RLC) entity, and a Logical Channel (LCH). One SLRB is uniquely associated with a set of address information, which includes a source address identifier (e.g., source L2 ID) and a destination address identifier (e.g., destination L2 ID), and the address information may also include a communication type (cast type). The cast type may be unicast, multicast, or broadcast.

[0123] 7) PC5 quality of service flow (PC5 QoS flow): One PC5 QoS flow is associated with one PFI. The PFI is an identifier assigned to the upper layer of the terminal device and is used to uniquely identify a QoS flow under a layer 2 destination address (destination L2 ID). One PFI is also associated with a set of QoS profiles. The QoS profile may include one or more of the following parameters: PC5 interface 5G quality of service identifier (PQI), guaranteed flow bit rate (GFBR), maximum flow bit rate (MFBR), minimum required communication range (range), allocation and retention priority (ARP), PC5LINK-aggregate maximum bit rate (PC5LINK-AMBR), default values, resource type, priority level, packet delay budget (PDB), packet error rate (PER), averaging window (for QoS flows of GBR and Delay-critical GBR resource types), or maximum data burst volume (for QoS flows of Delay-critical GBR resource type), etc. The resource type may be, for example, guaranteed bit rate (GBR), Delay critical GBR, or Non-GBR. In the embodiments of this application, the PC5 QoS flow may be simply referred to as the QoS flow.

[0124] 8) Relationship among service, QoS flow, or unicast connection: Two terminal devices performing SL communication are represented by UE A and UE B. An upper-layer PC5-S unicast connection may include multiple V2X services, and each service may also have multiple PC5 QoS flows. Different QoS flows are distinguished by the QoS flow identifier (PFI) at the same destination address. For example, PC5-S unicast connection 1 includes two V2X services, namely V2X service A and V2X service B. Service A has PC5 QoS flow 1 and PC5 QoS flow 2, and service B has PC5 QoS flow 3.

[0125] 9) The terms "system" and "network" in the embodiments of the present application may be used interchangeably. "At least one" means one or more, and "multiple" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B may be singular or plural. The character " / " generally represents an "or" relationship between the preceding and following associated objects. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c may represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c may be single or multiple.

[0126] Moreover, unless otherwise stated, the ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects and are not used to limit the size, content, order, timing, priority, or importance of multiple objects. For example, the first message and the second message are only used to distinguish different messages and do not indicate differences in the amount of information, content, sending order, priority, or importance of these two messages.

[0127] Some noun concepts related to the embodiments of the present application are introduced above. Next, the technical features involved in the embodiments of the present application are introduced.

[0128] The communication method provided by the embodiments of the present application can be applied to a 4th generation (4G) communication system, such as Long Term Evolution (LTE), and can also be applied to a 5th generation (5G) communication system, such as 5G New Radio (NR), or applied to various future communication systems, such as a 6th generation (6G) communication system, or a 7th generation (7G) communication system. The embodiments of the present application can also be applied to an Integrated Access and Backhaul (IAB) scenario.

[0129] With the development of technology, the relay communication of 5G NR technology introduced into User Equipment (UE) has started to be discussed in the 3GPP standard. In addition to being used for the above-mentioned public safety, the relay communication between UEs in 5G NR mainly considers the improvement of network and user system performance, such as coverage enhancement and capacity improvement.

[0130] Before introducing the solution, some concepts, terms, or descriptions of implementation processes mentioned in the embodiments of the present application are first introduced to facilitate a better understanding of the solution provided by the embodiments of the present application.

[0131] As Figure 1b shown, it is a schematic diagram of a communication system architecture to which the embodiments of the present application can be applied. The communication system includes at least two terminal devices: a first terminal device 101 and a second terminal device 102. The communication system may further include a relay device 103 that implements the function of relay forwarding. The relay device 103 can be a type of terminal device or a type of network device, which is not limited herein. The relay device can be one relay device or multiple relay devices (not shown in the figure). The first terminal device 101 and the second terminal device 102 can achieve data transmission through the relay device 103. The first terminal device 101 sends data to the second terminal device 102 through the relay device 103, and the second terminal device 102 sends data to the first terminal device 101 through the relay device 103. When the first terminal device 101 is outside the coverage area or at the edge of the coverage area of the second terminal device 102, or the second terminal device 102 is outside the coverage area or at the edge of the coverage area of the first terminal device 101, data can be relayed through the relay device 103 to achieve coverage enhancement of the sidelink. Communication between the first terminal device 101 and the relay device 103 is through the sidelink, and communication between the relay device 103 and the second terminal device 102 is also through the sidelink. The first terminal device 101 can be one terminal device or include multiple terminal devices. For example, as Figure 1cAs shown, when the terminal device is called a UE, the second terminal device 102 can be denoted as UE2, and the first terminal device 101 can include three third terminal devices (UE1, UE3, and UE4). Taking the first terminal device as UE1 as an example, UE2 establishes a unicast connection through a relay device to perform U2U relay communication with UE1, enabling UE2 to send data to UE1 through the relay device.

[0132] The first terminal device 101, the second terminal device 102, and the relay device 103 can all be collectively referred to as terminal devices. For the sake of distinction, they can be represented by a first communication device, a second communication device, and a relay device. Among them, the first communication device corresponds to the first terminal device, the second communication device corresponds to the second terminal device, and the relay device corresponds to the relay device. In the embodiments of the present application, the devices implementing the method functions are uniformly introduced by taking the terminal device as an example.

[0133] When the terminal device is called a UE, combined with Figure 1b the communication scenario shown can also be called user equipment to user equipment relay (UE to UE relay, U2U relay) communication. The communication between the source terminal device and the relay device and between the relay device and the destination terminal device is SL unicast communication. The source terminal device, the relay device, and the destination terminal device can be in the RRC connected state, the RRC idle state, the RRC inactive state, or the OOC state.

[0134] Taking the relay device as a base station as an example. In a possible scenario, under the condition that the source terminal device and the destination terminal device are within the network coverage (in coverage, IC) of the relay device (for example, a base station), the source terminal device and the destination terminal device can independently access the network of the relay device through the Uu interface. The network corresponding to the relay device can control the communication configuration and the allocation of communication resources on the uplink and downlink between the source terminal device and the destination terminal device. For example, real-time resource scheduling on the UL and DL can be performed. For the case where the source terminal device and the destination terminal device are in the IC state of the relay device, reference can be made to Figure 1d . Figure 1d It includes a relay device 103 (for example, base station 1), a first terminal device 101, and a second terminal device 102. Base station 1 is the base station accessed by the first terminal device 101, base station 1 is the base station accessed by the second terminal device 102, and base station 1 is the relay device for the first terminal device 101 and the second terminal device 102.

[0135] For ease of description, the relay device is taken as a relay terminal device as an example. Operators can deploy a relay terminal device, which has stronger capabilities, such as more receiving and transmitting antennas. The relay terminal device can assist the two terminal devices of the U2U relay communication to transfer data, thereby improving coverage and increasing communication distance. For example, when the coverage signal between one terminal device and another terminal device is poor, or one terminal device is out of the coverage range of another terminal device, the coverage range can be enhanced through the relay terminal device, and the capacity of the sidelink system can also be improved.

[0136] Combination Figure 1b , the second terminal device sends data to the first terminal device through the relay device. The second terminal device can also be called a transmitter, a data transmitter or a U2U relay data transmitter, and the first terminal device can also be called a receiver, a data receiver or a U2U relay data receiver; the first terminal device sends data to the second terminal device through the relay device. The first terminal device can also be called a transmitter, a data transmitter or a U2U relay data transmitter, and the second terminal device can also be called a receiver, a data receiver or a U2U relay data receiver. When applied to the scenario where the second terminal device establishes a unicast connection with the first terminal device, if the second terminal device initiates a unicast connection establishment request, the second terminal device can also be called an initiator of the end-to-end unicast connection establishment, and if the first terminal device initiates a unicast connection establishment request, the second terminal device can also be called a receiver of the end-to-end unicast connection establishment.

[0137] For example, the first terminal device is recorded as UE1, the second terminal device is recorded as UE2, and the relay device is recorded as relay UE. During UE-to-UE relay communication, there is a source UE2 (as a source terminal device), a destination UE1 (as a destination terminal device) and one or more relay devices, wherein there is a need for unicast communication between UE2 and UE1. UE2 and UE1 can transmit data and signaling through the relay device. The source terminal device and the relay device, as well as the relay device and the destination terminal device, communicate through the side link. UE2 communicates with UE1 through the relay UE. UE1 is outside the coverage range of UE2 or at the edge of the coverage range, UE2 needs to send data to UE1, UE2 can send data to the relay UE, and the relay UE forwards the data to UE1. Similarly, UE2 is outside the coverage range of UE1 or at the edge of the coverage range, UE1 needs to send data to UE2, UE1 can send data to the relay UE, and the relay UE forwards the received data to UE2. Thereby, the side link coverage enhancement between UE2 and UE1 is achieved.

[0138] Currently, there are two possible implementation methods for UE-to-UE relay: the relay method based on L3 (Layer 3), and the relay method based on L2 (Layer 2).

[0139] A possible relay form is the relay method based on L3. For example, using the UE to UE relay architecture of L3, in the user plane, the source terminal device, the relay device, and the destination terminal device perform relay at the IP layer. The user plane data is relayed and forwarded at the IP layer. For example, for the data packet sent from UE2 to UE1, the relay device needs to parse it to the IP layer and determine the forwarding to UE2 according to information such as the layer 2 identifier.

[0140] Another possible relay form is layer 2 (L2) relay. In the relay method based on L2, the user plane data is relayed and forwarded below the PDCP layer. Figure 3 Fig. is a schematic diagram of the protocol stack of the user plane under L2 relay. The protocol stacks of the source terminal and the destination terminal at least include: the upper layer (such as the V2X layer or the PC5-S layer), the service data adaptation protocol (SDAP) layer, the PDCP layer, the Adaption layer, the radio link control (RLC) layer, the media access control (MAC) layer, and the physical layer (PHY layer). The protocol stack of the relay device at least includes: the Adaption layer, the RCL layer, the MAC layer, and the PHY layer. Among them, the SDAP layer, the PDCP layer, the RLC layer, the Adaption layer, the MAC layer, and the PHY layer can be collectively referred to as belonging to the access stratum (AS). The upper layer, such as including the PC5-S layer or the V2X layer, is the layer above the access stratum. For the functions of the protocol layers, such as the SDAP layer, the PDCP layer, the RLC layer, etc., their definitions and functions can refer to the descriptions of the prior art and will not be elaborated here.

[0141] In the above two relay methods, since the source terminal device sends data to the destination terminal device through the relay device, when the source terminal device forwards data to the relay device, the protocol layers below the RLC layer of the source terminal device do not perceive the layer 2 identifier of the peer terminal device. When the destination terminal device receives data, it also receives it through the relay device, and the protocol layers below the RLC layer of the destination terminal device do not perceive the layer 2 identifier of the peer terminal device either, which will cause some problems. For example, combined with Figure 1cAs shown, on the same unicast connection established between a source terminal device (e.g., UE2) and a relay terminal device, multiple unicast links associating the relay terminal device with different destination terminal devices (e.g., UE1, UE3, and UE4) are involved. At this time, since the source terminal device cannot perceive the layer 2 identifier of the destination terminal device, it is unable to request different resources or bearer configurations based on different destination terminal devices, and can only use the same resources or bearer configurations for different destination terminal devices. Therefore, the data transmission of some destination terminal devices may have a relatively low transmission quality and cannot meet their preset transmission quality requirements.

[0142] The following introduces the relay process of user plane data to illustrate the reason why the source terminal device cannot perceive the layer 2 identifier of the destination terminal device. The relay terminal device maintains a relay RLC bearer and relays the sidelink data transmission between the second terminal device (e.g., UE2) and the first terminal device (e.g., UE1).

[0143] The relay terminal device will allocate a second identifier of the relay terminal device, e.g., identifier B2, for the communication link between the source terminal device and the relay terminal device, which is specifically used for transmitting the data packets exchanged between the source terminal device and the relay terminal device in U2U relay. The relay terminal device will allocate a first identifier of the relay terminal device, e.g., identifier B1, for the communication link between the destination terminal device and the relay terminal device, which is specifically used for transmitting the data packets exchanged between the destination terminal device and the relay terminal device in U2U relay.

[0144] The identifier of the source terminal device can be an identifier assigned by the source terminal device itself or an identifier assigned by the relay terminal device to the source terminal device, e.g., identifier A. For example, refer to Figure 3 , between the source terminal device and the relay terminal device, a transmission data packet with source address as identifier A and destination address as identifier B2 is sent; for example, for the transmission from the second terminal device to the relay terminal device, when the second terminal device sends a data packet to the relay terminal device, it uses identifier A as the source address and the second identifier B2 set by the relay terminal device for the communication link between the source terminal device and the relay terminal device as the destination address, and sends the data packet to the relay terminal device through the sidelink radio bearer between the second terminal device and the relay terminal device.

[0145] After receiving the data packet, the relay terminal device modifies it to the first identifier of the relay terminal device and the identifier of the destination terminal device according to the identifier of the source terminal device and the second identifier of the relay terminal device, and then forwards the data packet to the destination terminal device. The data packet being forwarded is associated with the first identifier of the relay terminal device and the identifier of the destination terminal device.

[0146] For example, for the data packet sent by the source terminal device, the relay terminal device parses the data packet to determine that identifier A and identifier B2 correspond to identifier B1 and identifier C, thereby modifying the source address and destination address of the data packet. The relay terminal device needs to replace the source address of the data packet with the first identifier of the relay terminal device. For example, identifier B1. The destination address is replaced with the identifier of the first terminal device. The identifier of the first terminal device can be an identifier assigned by the destination terminal device itself or an identifier assigned by the relay terminal device for the destination terminal device. For example, identifier C. At this time, the relay terminal device sends the data packet with the replaced source address and destination address to the first terminal device.

[0147] Correspondingly, for the data packet sent by the destination terminal device to the relay terminal device, the source address that the data packet can carry is identifier C, and the destination address is the first identifier of the relay terminal device. For example, identifier B1. After the relay terminal device receives the data packet, the relay terminal device needs to replace the destination address of the data packet with the identifier of the second terminal device. For example, identifier A, and replace the source address with the second identifier of the relay terminal device. For example, identifier B2, and then send the replaced data packet to UE2.

[0148] The specific process of the relay terminal device setting corresponding identifiers for the communication links of the source terminal device and the destination terminal device can be set during the corresponding unicast connection process. Taking the communication between the first terminal device and the second terminal device as an example, the two terminal devices can communicate through a relay device. The link through the relay device can be called a relay link. For example, Figure 1b The relay link for the first terminal device and the second terminal device to communicate through the relay device can include two: the link between the first terminal device and the relay device, and the link between the relay device and the second terminal device. As Figure 4 shown, taking the second terminal device initiating a unicast connection establishment request as an example to illustrate the process of establishing a unicast connection. It includes:

[0149] Step 401: When the set conditions are met, the second terminal device triggers the establishment of a communication link.

[0150] Among them, the communication link includes a first communication link and a second communication link. The first communication link is the link between the first terminal device and the relay device, and the second communication link is the link between the second terminal device and the relay device.

[0151] When the second terminal device meets the trigger condition, it triggers the establishment of the second communication link or triggers the sending of a corresponding unicast connection establishment request (direct communication request) message.

[0152] Based on the NR V2X mode, there can be multiple ways for the second terminal device (e.g., UE2) to initiate a unicast connection establishment request message. For example, the UE-triggered mode and the service-triggered mode.

[0153] In a possible implementation, before the second terminal device UE2 establishes a connection with the destination terminal device (e.g., UE1), the second terminal device UE2 determines the layer 2 identifier (destination L2 ID) of the first terminal device through the upper-layer application layer or other means. Among them, the layer 2 identifier of the destination terminal device can be an identifier configured by the upper layer for the destination terminal device for unicast connection. For example, the destination terminal device UE1 can determine the layer 2 identifier of UE1, the destination terminal device UE3 can determine the layer 2 identifier of UE3, and the destination terminal device UE4 can determine the layer 2 identifier of UE4. Further, the destination terminal device compares the layer 2 identifier corresponding to the received unicast connection establishment PC5-S signaling to determine whether to parse the unicast connection establishment PC5-S signaling.

[0154] After the upper layer of the source terminal device determines the layer 2 identifier of the destination terminal device, the second terminal device UE2 can send a unicast connection establishment request message (direct communication request) in unicast mode. That is to say, the destination address of this message is the layer 2 identifier corresponding to UE1 (e.g., L2 ID1); at this time, if UE1 agrees to establish a unicast connection, it can reply with a unicast connection establishment acceptance message (direct communication accept) in unicast mode.

[0155] In another possible implementation, the second terminal device UE2 can trigger a unicast connection request with the destination terminal device through a service. UE2 determines the service (e.g., V2X service) that needs to establish a connection through the upper-layer application layer or other means, and thus determines the layer 2 identifier corresponding to the service. UE2 sends a unicast connection establishment request message in broadcast mode, and the destination address of this message is the layer 2 identifier corresponding to the V2X service; the UEs (e.g., UE1 or UE4) interested in the corresponding service reply with a unicast connection establishment acceptance message in unicast mode.

[0156] Step 402: The second terminal device sends a unicast connection establishment (direct communicationrequest) message.

[0157] Among them, the unicast connection establishment request message may include: application identifier, application layer identifier of UE1, application layer identifier of the target UE, indication information for supporting relay, etc.

[0158] The unicast connection establishment request message sent by the source terminal device can be sent to the relay device in unicast mode after determining the relay device. The method of determining the relay device can be that the relay device broadcasts discovery messages or announcement messages to the surrounding terminal devices. Taking the announcement message as an example, the announcement message is used to indicate that the relay device has relay capabilities. The announcement message can be sent to the surrounding terminal devices through the PC5 interface. The surrounding terminal devices will determine that the relay device has relay capabilities by receiving the announcement message. It can also be that the source terminal device sends the unicast connection establishment request message in broadcast mode, and determines whether to establish a unicast connection with the destination terminal device through the relay device, which is not limited here.

[0159] Step 403: The relay device receives the unicast connection establishment request message sent by the second terminal device UE2, and forwards the unicast connection establishment request message;

[0160] Among them, the relay device can determine whether the application is supported according to the application information in the unicast connection establishment request message (for example, the indication information supporting relay, the application identifier, the application layer identifier of UE2, the application layer identifier of the target UE, etc.) and the application information configured for itself. If the matching result is supported, the relay device can allocate a first identifier of the relay device for the first communication link between the relay device and the destination relay device, for example, R1-L2-ID-a or identifier B1. This first identifier is associated with the layer 2 identifier of the source terminal device and is used to forward the unicast connection establishment request message and the subsequent communication between the relay device and the first terminal device (UE1).

[0161] In the forwarded unicast connection establishment request message, the source address can be modified to the first identifier (for example, R1-L2-ID-a, or identifier B1), and the destination address can still be the layer 2 identifier of UE1. At the same time, the identifier of the relay device can also be added to the forwarded unicast connection establishment request message. For example, the identifier of the relay device can be the unique relay identifier (RID). For example, the unique relay identifier of the first relay device can be expressed as RID1. The unique relay identifier of the second relay device can be expressed as RID2.

[0162] Step 404: The second terminal device and the first terminal device trigger the security establishment process.

[0163] The first terminal device is interested in the application indicated in the unicast connection establishment request message, triggers the security establishment process with the second terminal device, and after establishing security through the upper layer, will notify the corresponding security configuration (security algorithm, security parameter, security policy, etc.) to the AS layer. The AS layer uses the corresponding security configuration to forward the messages in the security establishment process through the relay device; thereby realizing the security protection for the PC5-S message, PC5-RRC message and user plane data transmitted between the source terminal device and the destination terminal device through the relay device. The specific process can be referred to Figure 2 in the manner of.

[0164] It can be understood that the relay device receives the security establishment command (Direct SecurityMode Command) message sent by the first terminal device. The relay device determines that the message needs to be forwarded to the second terminal device according to the mapping relationship stored by itself. Thus, the relay device assigns a second identifier of the relay device to itself, for example, (R1-L2-ID-b, or identifier B2). The second identifier of the relay device is associated with the layer 2 identifier of the destination terminal device and is used for communication between the relay device and the second terminal device.

[0165] For example, in the message sent by the second terminal device to the first terminal device received by the relay device through the second communication link, the destination address of the message is the second identifier of the relay device (for example, R1-L2-ID-b), and the source address is the L2 ID of the second terminal device. When the relay device forwards the message of the second terminal device to the first terminal device through the first communication link, the source address of the message is the first identifier (for example, R1-L2-ID-a or identifier B1), and the destination address is the layer 2 identifier of the first terminal device.

[0166] Thus, the relay device maintains the mapping relationship of the layer 2 identifiers of the first communication link between the relay device and the first terminal device (UE1) and the layer 2 identifiers of the second communication link between the relay device and the second terminal device. Taking the relay device as the first relay terminal device as an example, the mapping relationship maintained by the first relay terminal device for the first terminal device (UE1) and the second terminal device (UE2) can be shown in Table 1.

[0167] Table 1

[0168]

[0169] Step 405: The relay device receives the unicast connection establishment accept (DirectCommunication Accept) message sent by the first terminal device UE1.

[0170] With reference to Table 1, the first relay device receives the message via the first communication link. The source address of the message can be the layer 2 identifier of the first terminal device UE1, and the destination address of the message can be the first identifier of the first relay device.

[0171] Step 406: Forward the unicast connection establishment acceptance message sent by the first terminal device UE1 to the second terminal device UE2 via the relay device.

[0172] With reference to Table 1, the first relay device sends the message via the second communication link. The source address of the message can be the second identifier of the first relay device, and the destination address of the message can be the layer 2 identifier of the second terminal device UE2.

[0173] After the U2U relay unicast connection is established, a unicast connection is uniquely associated with a pair of source layer 2 identifier (source L2ID) and destination layer 2 identifier (destination L2 ID). That is, in the unicast connection between the source terminal device and the relay device, it is associated through the layer 2 identifier of the source terminal device and the second identifier of the relay device. In the unicast connection between the relay device and the destination terminal device, it is associated through the layer 2 identifier of the destination terminal device and the first identifier of the relay device.

[0174] Optionally, after the destination communication link is established, step 407 may further be included.

[0175] Step 407: The second terminal device communicates with the first terminal device via the communication link.

[0176] The sidelink communication may include one of the two communication directions or both communication directions may exist simultaneously. The two communication directions are respectively:

[0177] 1) The second terminal device sends data to the first terminal device.

[0178] The second terminal device sends the first data to the first relay device via the second communication link. The source address of the first data is the layer 2 identifier of the second terminal device, and the destination address of the first data is the second identifier of the first relay device (e.g., R1-L2-ID-b). After receiving the first data, the first relay device modifies the source address to the first identifier of the first relay device (e.g., R1-L2-ID-a), and the destination address to the identifier of the first terminal device. The first relay device forwards the second data to the first terminal device via the first communication link.

[0179] 2) The first terminal device sends data to the second terminal device.

[0180] The first terminal device sends the second data to the first relay device via the first communication link. The source address of the second data is the layer 2 identifier of the first terminal device, and the destination address of the second data is the first identifier (R1-L2-ID-a) of the first relay device. After receiving the second data, the first relay device modifies the source address to the second identifier (R1-L2-ID-b) of the first relay device and the destination address to the identifier of the second terminal device, and the first relay device forwards the second data to the second terminal device via the second communication link.

[0181] In addition, the first terminal device can also achieve relay communication between the first terminal device and the second terminal device based on a multi-hop manner. For example, the first terminal device communicates with the second terminal device via the first relay device and the second relay device.

[0182] During the above relay process, after the U2U relay unicast connection is established, the relay terminal device can identify which data packets are from the source terminal device. However, for the protocol layers below the RLC layer of the source terminal device and the destination terminal device, it only sends data packets to the relay device or receives data packets from the relay device, and does not know that some of the data packets are actually associated with the source terminal device or the destination terminal device. That is, the protocol layers below the RLC layer of the source terminal device and the destination terminal device do not perceive the layer 2 identifiers of the peer terminal devices, which may cause some problems. For example, on the same unicast connection established between the source terminal device (UE2) and the relay device, multiple unicast links associating the relay device with different destination terminal devices (for example, UE1, UE3, and UE4) are associated. At this time, the same resources or bearer configurations can only be used for different destination terminal devices. Therefore, the data transmission of some destination terminal devices may have a low transmission quality and cannot meet their preset transmission quality requirements.

[0183] In view of this, the technical solutions of the embodiments of the present application are provided. Based on Figures 1a - 1d the description of the V2X communication architecture 100 shown, in the following introduction process, it is assumed that this method is applied to Figures 1b - 1c the network architecture shown as an example. The communication method provided by the embodiments of the present application will be introduced in detail below. The application scenarios of the embodiments of the present application can refer to Figures 1a - 1d . For the convenience of introduction, in the following, it is assumed that this method is executed by the relay device and the terminal device. Because the embodiments of the present application are based on the network architecture shown in Figure 1b as an example. Therefore, the relay device in the following can be Figure 1b the terminal device in the network architecture shown. The first terminal device in the following can be Figure 1b the first terminal device 101 in the network architecture shown, and the second terminal device in the following can be Figure 1bThe terminal device 102 in the network architecture shown. For example, the first terminal device 101 may be UE1, and the second terminal device 102 may be UE2. The L2 ID used by UE1 is L2 ID 1, the L2 ID used by UE2 is L2 ID 2, and the L2 ID used by the relay device may include a first identifier (e.g., L2 ID a) (for communication between the relay device and UE1) and a second identifier (e.g., L2 ID b) (for communication between the relay device and UE2).

[0184] The first communication method provided by the embodiments of this application is shown in Figure 5 , which is a flowchart of this method. Specifically, it may include the following steps:

[0185] Step 501a: The first relay device sends a second message to the first terminal device.

[0186] Wherein, the second message includes the identifier of the second terminal device.

[0187] Wherein, the identifier of the second terminal device may be the layer 2 identifier of the second terminal device, the adaptation layer identifier of the second terminal device, or the identifier assigned by the first relay device to the second terminal device.

[0188] In a possible implementation, the timing for the relay device to send the second message to the first terminal device or the first message to the second terminal device may be during the unicast establishment process. The second message may be any one of the following: unicast connection establishment request message, unicast connection establishment acceptance message, security activation command message, security activation completion message. The second message may also be sent after the unicast connection is established. The second message may be any one of the following: PC5-RRC message, PC5-S message, etc.

[0189] Step 502a: The first terminal device communicates with the second terminal device according to the identifier of the second terminal device.

[0190] The following takes the first terminal device receiving the third data forwarded by the second terminal device via the first relay device through the first communication link as an example for illustration.

[0191] Combined with Figure 3As shown, the second protocol layer of the first terminal device receives the third data, which is the data sent by the second terminal device and received by the first terminal device through the first relay device. In the data packet of the third data received by the second protocol layer, the source address is the first identifier of the first relay device, and the destination address is the identifier of the first terminal device. That is, the third data is associated with the first identifier of the first relay device and the identifier of the first terminal device. To enable the upper layer of the first terminal device to recognize the third data as the data corresponding to the second terminal device, when the third data is delivered to the first protocol layer of the first terminal device, the source address needs to be modified to the identifier of the second terminal device. That is, the modification of the source address can be achieved through the second protocol layer of the first terminal device. That is, the second protocol layer of the first terminal device determines the fourth data according to the third data; the source address of the fourth data is the identifier of the second terminal device, and the destination address of the fourth data is the identifier of the first terminal device. That is, the fourth data is associated with the identifier of the second terminal device and the identifier of the first terminal device. Optionally, the destination addresses (the identifier of the first terminal device) of the third data and the fourth data may be different, that is to say, the destination address of the third data can also be modified. After the second protocol layer of the first terminal device delivers the fourth data to the first protocol layer of the first terminal device, the first protocol layer of the first terminal device and the upper layer of the first protocol layer can recognize the fourth data as the data from the second terminal device.

[0192] The above method for modifying the source address can be implemented through different protocol layers. For example, the second protocol layer can be the RLC layer or the adaptation layer, and the first protocol layer can be the adaptation layer or the PDCP layer. The following uses method a1 and method a2 as examples for illustration.

[0193] In method a1, the second protocol layer is the RLC layer, and the first protocol layer is the adaptation layer or the PDCP layer. The RLC layer receives the third data from the first relay device. The source address of the third data is the first identifier of the first relay device (for example, R1-L2ID-a), and the destination address is the identifier of the first terminal device (for example, L2 ID1). The RLC layer modifies the source address in the third data to the layer 2 identifier of the second terminal device (for example, L2 ID2), thereby determining the fourth data. The fourth data is delivered to the adaptation layer or the PDCP layer to enable the PDCP layer or the upper layer to recognize the fourth data as the data from the first terminal device after receiving the fourth data.

[0194] In mode a2, the second protocol layer is the adaptation layer and the first protocol layer is the PDCP layer. The adaptation layer receives the third data from the first relay device. The source address of the third data is the first identifier of the first relay device (e.g., R1-L2 ID-a), and the destination address is the identifier of the first terminal device (e.g., L2 ID1). The adaptation layer modifies the source address in the third data to the layer 2 identifier of the second terminal device (e.g., L2 ID2), thereby determining the fourth data. The fourth data is delivered to the PDCP layer so that after the PDCP layer or the upper layer receives the fourth data, it can identify that the fourth data is from the first terminal device.

[0195] Step 501b: The first relay device sends a first message to the second terminal device.

[0196] Wherein, the first message includes the identifier of the first terminal device.

[0197] Wherein, the identifier of the first terminal device can be the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or the identifier assigned by the first relay device to the first terminal device.

[0198] In a possible implementation, the timing for the relay device to send the first message to the second terminal device or the second message to the first terminal device can also be during the data transmission process after the unicast connection is established. The first message can be any of the following: unicast connection establishment request message, unicast connection establishment acceptance message, security activation command message, security activation completion message. The first message can also be sent after the unicast connection is established. The first message can be any of the following: PC5-RRC message, PC5-S message, etc.

[0199] Therefore, the first message can be any of the following: unicast connection establishment request message, unicast connection establishment acceptance message, security activation command message, security activation completion message, PC5-RRC message, PC5-S message, etc.

[0200] Step 502b: The second terminal device communicates with the first terminal device according to the identifier of the first terminal device.

[0201] In a possible implementation, taking the second terminal device as the source terminal device as an example, the second terminal device can request the radio bearer configuration corresponding to the first terminal device according to the identifier of the first terminal device. Specifically, it can include the following steps:

[0202] Step 5021b: The second terminal device sends a first request message to the access network device.

[0203] Among them, the first request message is used to request the first radio bearer configuration information corresponding to the first terminal device. The first request message may include: the first QoS information and the identifier of the first terminal device.

[0204] Among them, the first QoS information is the QoS information corresponding to UE1.

[0205] For example, the access network device may be the serving base station registered by the second terminal device. The first request message may be a sidelink UE information (SUI) message, and the SUI message may carry the address information of the first terminal device (for example, the identifier of the first terminal device (for example, destination ID), the type of the first terminal device (cast type)), and QoS information (for example, QoS flow ID and / or QoS profile). Thus, the access network device is requested to configure the first radio bearer configuration information for the first terminal device respectively through the QoS information reported in the first request message.

[0206] Step 5022b: The access network device determines the first radio bearer configuration information according to the first request message.

[0207] Among them, the first radio bearer configuration information may be the configuration information of the SLRB required for the communication link between the second terminal device and the first terminal device.

[0208] Step 5023b: The access network device sends a first response message to the second terminal device.

[0209] Among them, the first response message may include: the first radio bearer configuration information.

[0210] Thus, the second terminal device may establish a corresponding radio bearer according to the first radio bearer configuration information, and send data to the first terminal device or receive data from the first terminal device through the first relay device.

[0211] The following takes the second terminal device sending the first data to the first terminal device as an example for illustration.

[0212] Combined with Figure 3 As shown, the upper layer of the second terminal device determines the first data, and the first data is the data sent by the second terminal device to the first terminal device through the first relay device.

[0213] The upper layer (application layer, V2X layer, SDAP layer, etc.) of the second terminal device determines the first data and transmits the first data to the first protocol layer; in the data packet of the first data received by the first protocol layer, the source address is the second terminal device and the destination address is the first terminal device. That is, the first data is associated with the identifier of the second terminal device and the identifier of the first terminal device. To forward the first data to the first terminal device through the first relay device, when the first data is sent down to the second protocol layer, the destination address needs to be modified to the second identifier of the first relay device. Therefore, the modification of the destination address can be achieved through the first protocol layer. That is, the first protocol layer determines the second data according to the first data; the source address of the second data is the identifier of the second terminal device, and the destination address of the second data is the second identifier of the first relay device. That is, the second data is associated with the identifier of the second terminal device and the second identifier of the first relay device. Optionally, the source addresses (identifiers of the second terminal device) of the first data and the second data may be different, that is to say, the source address of the first data may also be modified. After the first protocol layer sends the second data to the second protocol layer, the second data can be sent to the first relay device. The first relay device determines that the second data is the data to be forwarded to the first terminal device according to the source address and destination address of the second data.

[0214] The above method for modifying the destination address can be implemented through different protocol layers. For example, the first protocol layer can be the PDCP layer or the adaptation layer, and the second protocol layer can be the adaptation layer or the RLC layer. The following takes method b1 and method b2 as examples for illustration.

[0215] In method b1, the first protocol layer is the PDCP layer and the second protocol layer is the adaptation layer or the RLC layer. The PDCP layer receives the first data from the upper layer. The source address of the first data is the layer 2 identifier of the second terminal device (for example, L2 ID2), and the destination address is the identifier of the first terminal device (for example, L2 ID1). The PDCP layer modifies the destination address in the first data to the second identifier of the first relay device (for example, R1-L2-ID-b), thereby determining the second data. The second data is delivered to the adaptation layer or the RLC layer so that after the RLC layer receives the second data, the second data can be further delivered to the MAC and PHY layers and sent to the first relay device.

[0216] Mode b2, the first protocol layer is the adaptation layer, and the second protocol layer is the RLC layer. The adaptation layer receives first data from the upper layer. The source address of the first data is the layer 2 identifier of the second terminal device (e.g., L2 ID2), and the destination address is the identifier of the first terminal device (e.g., L2 ID1). The adaptation layer modifies the destination address in the first data to the second identifier of the first relay device (e.g., R1-L2-ID-b). Thus, the adaptation layer determines second data. The adaptation layer delivers the second data to the RLC layer, so that after the RLC layer receives the second data, it can further deliver the second data to the MAC and PHY layers and send it to the first relay device.

[0217] By obtaining the end-to-end L2 ID during the establishment process of the U2U relay unicast connection, the protocol layers of UE1 and UE2 maintain the L2 ID mapping relationship, which can reasonably and better maintain the bearer model and ensure the normal communication of the U2U relay.

[0218] The following uses Example 1 to Example 4 to illustrate Figure 5 the implementation manners of Step 501a and Step 501b in the communication method in

[0219] Example 1

[0220] An embodiment of the present application provides a communication method. Please refer to Figure 6 , which is a flowchart of this method. In this communication method, through the U2U unicast connection establishment process, the first terminal device and the second terminal device obtain the identifiers of the peer through the first relay device to improve the association relationship of the L2 ID in the bearer model and improve the communication performance between the first terminal device and the second terminal device based on the first relay device. The specific steps may include:

[0221] Step 601: The second terminal device sends a unicast connection establishment request message.

[0222] A possible implementation manner is that the unicast connection establishment request message includes the identifier of the second terminal device (e.g., L2 ID 2), and may also include the adaptation layer identifier corresponding to the second terminal device;

[0223] Another possible implementation manner is that the unicast connection establishment request message does not include the layer 2 identifier of the second terminal device, but carries the layer 2 identifier or the adaptation layer identifier of the second terminal device through the MAC layer or the adaptation layer of the unicast connection establishment request message.

[0224] Step 602: The first relay device sends a unicast connection establishment request message to the first terminal device.

[0225] In a possible implementation, the unicast connection establishment request message may include the identifier of the second terminal device (e.g., L2 ID2), and may also include the adaptation layer identifier corresponding to the second terminal device.

[0226] In another possible implementation, the first relay device adds the layer 2 identifier (L2 ID2) of the second terminal device carried in the MAC layer or adaptation layer of the unicast connection establishment request message in step 601 to the unicast connection establishment request message in step 602.

[0227] Step 603a: The first terminal device sends a unicast connection establishment acceptance message to the first relay device.

[0228] Optionally, the unicast connection establishment acceptance message may include the layer 2 identifier L2 ID 2 of the first terminal device; it may also include the adaptation layer identifier corresponding to the first terminal device.

[0229] Optionally, the unicast connection establishment acceptance message does not include the layer 2 identifier of the first terminal device, but carries the layer 2 identifier or adaptation layer identifier of the first terminal device through the MAC layer or adaptation layer of the unicast connection establishment acceptance message.

[0230] Step 603b: The first terminal device sends a security activation command message to the first relay device.

[0231] In a possible implementation, the security activation command message may include the layer 2 identifier L2 ID 1 of the first terminal device, and may also include the adaptation layer identifier corresponding to the first terminal device.

[0232] In another possible implementation, the security activation command message does not include the layer 2 identifier of the first terminal device, but carries the layer 2 identifier or adaptation layer identifier of the first terminal device through the MAC layer or adaptation layer of the security activation command message.

[0233] Step 604a: The first relay device sends a unicast connection establishment acceptance message to the second terminal device.

[0234] Optionally, the unicast connection establishment acceptance message may include the layer 2 identifier of the first terminal device (e.g., the layer 2 identifier L2 ID1 of UE1), and may also include the adaptation layer identifier corresponding to the first terminal device.

[0235] Optionally, the first relay device may add the layer 2 identifier (L2 ID2) of the first terminal device carried in the MAC layer or adaptation layer of the message in step 603a or step 603b to the unicast connection establishment acceptance message in step 604a.

[0236] Step 604b: The first relay device sends a security activation command message to the second terminal device.

[0237] In a possible implementation, the security activation command message may include the layer 2 identifier of the first terminal device (e.g., the layer 2 identifier L2 ID1 of UE1), and may also include the adaptation layer identifier corresponding to the first terminal device.

[0238] In another possible implementation, the first relay device may add the layer 2 identifier (L2 ID2) of the first terminal device carried in the MAC layer or adaptation layer of the message in step 603b to the security activation command message in step 604b.

[0239] It should be noted that, to avoid repeated transmission of the layer 2 identifier of the first terminal device, the layer 2 identifier of the first terminal device may be carried in steps 603a - 604a or the layer 2 identifier of the first terminal device may be carried in steps 603b - 604b.

[0240] Example 2

[0241] Considering the scenario of multiple hops in U2U relay, an embodiment of the present application provides a communication method. As Figure 7 shown, taking two hops as an example for illustration, other scenarios of multiple hops can refer to this embodiment and will not be elaborated here. The specific steps may include:

[0242] Step 701: The second terminal device UE2 sends a unicast connection establishment request message to the second relay device.

[0243] In a possible implementation, the unicast connection establishment request message includes the layer 2 identifier (L2 ID 2) of the second terminal device.

[0244] In another possible implementation, the unicast connection establishment request message does not include the layer 2 identifier of the second terminal device, but carries the layer 2 identifier of the second terminal device through the MAC layer or adaptation layer of the unicast connection establishment request message.

[0245] Step 702: The second relay device sends a unicast connection establishment request message to the first relay device.

[0246] In a possible implementation, the unicast connection establishment request message includes the layer 2 identifier (L2 ID 2) of the second terminal device.

[0247] In another possible implementation, the unicast connection establishment request message does not carry the layer 2 identifier of the second terminal device, and the second relay device may carry the layer 2 identifier of the second terminal device through the MAC layer or adaptation layer of the unicast connection establishment request message.

[0248] Step 703: The first relay device sends a unicast connection establishment request message to the first terminal device.

[0249] In a possible implementation, the unicast connection establishment request message includes the layer 2 identifier (L2 ID 2) of the second terminal device.

[0250] In another possible implementation, the first relay device adds the layer 2 identifier (L2 ID2) of the second terminal device carried in the MAC layer or the adaptation layer of the unicast connection establishment request message in step 702 to the unicast connection establishment request message in step 703.

[0251] Step 704a: The first terminal device sends a unicast connection establishment acceptance message to the first relay device.

[0252] Optionally, the unicast connection establishment acceptance message includes the layer 2 identifier (L2 ID1) of the first terminal device; it may also include the adaptation layer identifier corresponding to the first terminal device.

[0253] Optionally, the unicast connection establishment acceptance message does not include the layer 2 identifier of the first terminal device, but carries the layer 2 identifier of the first terminal device through the MAC layer or the adaptation layer of the unicast connection establishment acceptance message.

[0254] Step 704b: The first terminal device sends a security activation command message to the first relay device.

[0255] In a possible implementation, the security activation command message may include the layer 2 identifier (L2 ID 1) of the first terminal device, and may also include the adaptation layer identifier corresponding to the first terminal device.

[0256] In another possible implementation, the security activation command message does not include the layer 2 identifier of the first terminal device, but carries the layer 2 identifier of the first terminal device through the MAC layer or the adaptation layer of the security activation command message.

[0257] Step 705a: The first relay device sends a unicast connection establishment acceptance message to the second relay device.

[0258] Optionally, the unicast connection establishment acceptance message may include the layer 2 identifier (L2 ID1) of the first terminal device, and may also include the adaptation layer identifier corresponding to the first terminal device.

[0259] Optionally, the unicast connection establishment acceptance message does not include the layer 2 identifier of the first terminal device, but carries the layer 2 identifier of the first terminal device through the MAC layer or the adaptation layer of the unicast connection establishment acceptance message.

[0260] Step 705b: The first relay device sends a security activation command message to the second relay device;

[0261] A possible implementation is that the secure activation command message includes the layer 2 identifier (L2ID1) of the first terminal device, and may also include the adaptation layer identifier corresponding to the first terminal device.

[0262] Another possible implementation is that the secure activation command message does not include the layer 2 identifier of the first terminal device, but carries the layer 2 identifier of the first terminal device through the MAC layer or the adaptation layer of the secure activation command message.

[0263] Step 706a: The second relay device sends a unicast connection establishment acceptance message to the second terminal device.

[0264] Optionally, the unicast connection establishment acceptance message includes the layer 2 identifier (L2 ID1) of the first terminal device, and may also include the adaptation layer identifier corresponding to UE1.

[0265] Optionally, the second relay device adds the layer 2 identifier (L2 ID2) of the first terminal device carried by the MAC layer or the adaptation layer of the message in step 705a or 705b to the unicast connection establishment acceptance message in step 706a.

[0266] Step 706b: The second relay device sends a secure activation command message to the second terminal device.

[0267] A possible implementation is that the secure activation command message includes the layer 2 identifier (L2ID1) of the first terminal device, and may also include the adaptation layer identifier corresponding to the first terminal device.

[0268] Another possible implementation is that the second relay device adds the layer 2 identifier (L2 ID2) of the first terminal device carried by the MAC layer or the adaptation layer of the secure activation command message in step 705b to the secure activation command message in step 706b.

[0269] It should be noted that to avoid repeated transmission of the layer 2 identifier of the first terminal device, the layer 2 identifier of the first terminal device can be carried in steps 704a to 706a or the layer 2 identifier of the first terminal device can be carried in steps 704b to 706b.

[0270] Example 3

[0271] Consider another possible implementation. The relay device may send the identifier of the peer to the terminal device after the U2U relay unicast connection establishment process, so that the first terminal device and the second terminal device can obtain the identifier of the peer. As Figure 8 shown, it includes the following steps:

[0272] Step 801: The second terminal device sends a second message to the first relay device.

[0273] Step 802: The first relay device forwards the second message to the first terminal device.

[0274] Wherein, the second message may be a PC5-RRC message or a PC5-S message. The second message may include the layer 2 identifier (L2 ID2) of the second terminal device (UE2), and may also include the adaptation layer identifier corresponding to the second terminal device.

[0275] Step 803: The first terminal device sends a first message to the first relay device.

[0276] Step 804: The first relay device forwards the first message to the second terminal device.

[0277] Wherein, the first message may be a PC5-RRC message or a PC5-S message. The first message may include the layer 2 identifier (e.g., L2 ID 1) of the first terminal device, and may also include the adaptation layer identifier corresponding to the first terminal device.

[0278] It should be noted that there is no sequence between step 801 and step 803. For example, step 801 and step 802 may be executed first, and then step 803 and step 804; or step 803 and step 804 may be executed first, and then step 801 and step 802. It may be that the second terminal device sends the second message first, and then the first terminal device sends the first message, or it may be that the first terminal device sends the first message first, and the second terminal device sends the second message later, which is not limited herein.

[0279] Example 4

[0280] Considering the scenario of multi-hop in U2U relay, an embodiment of the present application provides a communication method. As Figure 9 shown, taking two-hop as an example for illustration, the relay device may include a first relay device and a second relay device. The first relay device and the second relay device jointly provide relay services for the second terminal device and the first terminal device. Among them, the first relay device establishes a unicast connection communication link with the first terminal device, and the second relay device establishes a unicast connection communication link with the second terminal device. Data can be forwarded between the first relay device and the second relay device to achieve multi-hop. Other multi-hop scenarios can refer to this embodiment and will not be elaborated herein. The specific steps may include:

[0281] Step 901: The second terminal device sends a third message to the second relay device.

[0282] Wherein, the third message may be a PC5-RRC message or a PC5-S message.

[0283] A possible implementation manner is that the third message may include the identifier of the second terminal device.

[0284] Another possible implementation manner is that the third message does not include the identifier of the second terminal device, but carries the identifier of the second terminal device through the MAC layer or the adaptation layer of the third message.

[0285] Step 902: The second relay device forwards the third message to the first relay device.

[0286] A possible implementation manner is that the third message forwarded to the first relay device may include the identifier of the second terminal device.

[0287] Another possible implementation manner is that the third message forwarded to the first relay device does not include the identifier of the second terminal device, but carries the identifier of the second terminal device through the MAC layer or the adaptation layer of the third message.

[0288] Step 903: The first relay device forwards the third message to the first terminal device.

[0289] A possible implementation manner is that the third message includes the identifier of the second terminal device. Among them, the identifier of the second terminal device may be the layer 2 identifier of the second terminal device (UE2), or may also be the adaptation layer identifier of UE2.

[0290] Step 904: The first terminal device sends a fourth message to the first relay device.

[0291] Among them, the fourth message may be a PC5-RRC message or a PC5-S message.

[0292] A possible implementation manner is that the fourth message may include the identifier of the first terminal device.

[0293] Another possible implementation manner is that the fourth message does not include the identifier of the first terminal device, but carries the identifier of the first terminal device through the MAC layer or the adaptation layer of the fourth message.

[0294] Step 905: The first relay device forwards the fourth message to the second relay device.

[0295] A possible implementation manner is that the fourth message forwarded to the second relay device may include the identifier of the first terminal device.

[0296] Another possible implementation manner is that the fourth message does not include the identifier of the first terminal device. Instead, it carries the identifier of the first terminal device through the MAC layer or the adaptation layer of the fourth message.

[0297] Step 906: The second relay device forwards the fourth message to the second terminal device.

[0298] In a possible implementation, the fourth message includes the identifier of the first terminal device; the identifier of the first terminal device may be the layer 2 identifier of the first terminal device (UE1), or may also be the adaptation layer identifier of UE1.

[0299] It should be noted that there is no sequence between step 901 to step 903 and step 904 to step 906. It may be that the second terminal device first sends the third message, and then the first terminal device sends the fourth message. It may also be that the first terminal device first sends the fourth message, and the second terminal device then sends the third message. This is not limited here.

[0300] By obtaining the end-to-end L2 ID during the establishment process of the U2U relay unicast connection, the UE1 and UE2 protocol layers maintain the L2 ID mapping relationship, which can reasonably and better maintain the bearer model and ensure the normal communication of the U2U relay.

[0301] When considering that the second terminal device communicates with multiple terminal devices through a relay device, by indicating the established unicast connection between the second terminal device and the relay device to establish a unicast connection between the relay device and the new destination terminal device, the number of required unicast connections can be reduced, and the resource overhead can be reduced. As shown in Figure 1c As shown, the second terminal device and the first terminal device establish a unicast connection through the first relay device. For example, the second terminal device 102 may be UE2, and the first terminal device 101 may include N third terminal devices. Taking N as 3, the third terminal device may be one of UE1, UE3, and UE4. UE2 sends data to UE1 through the relay device. Taking the first terminal device as UE1 as an example. UE2 establishes a unicast connection through the relay device to perform U2U relay communication with UE1. The L2 ID used by UE2 is L2 ID 2, the L2 ID used by UE1 is L2 ID 1, and the L2 IDs assigned by the relay device for use are L2 ID a (for communication between the relay device and UE1) and L2 ID b (for communication between the relay device and UE2) respectively.

[0302] At this time, UE2 can initiate the establishment of a connection with the new destination terminal device (for example, the fourth terminal device UE3) through the unicast connection corresponding to the same relay device, so as to enable UE2 to communicate with multiple destination terminal devices simultaneously through a unicast connection corresponding to the same relay device.

[0303] Combined with Figure 5 the communication method in Figure 10 As shown, the embodiment of the present application further provides another communication method. When the second terminal device has obtained the identifier of the first terminal device, based on the second communication link between UE2 and the first relay device, it requests the first relay device to establish a unicast connection with the fourth terminal device. The specific process is as followsFigure 10 As shown in the figure, it includes the following steps:

[0304] Step 1001: The second terminal device sends a third request message to the first relay device.

[0305] Among them, the third request message is used to request the first relay device to establish a unicast connection with the fourth terminal device, and the fourth terminal device can be one of the third terminal devices that have not established a communication connection with the second terminal device. For example, this third request message is used to instruct the relay device to establish a corresponding unicast connection with UE3.

[0306] A possible implementation is that the third request message is a PC5-RRC message, and this PC5-RRC message is the PC5 RRC message for the unicast connection between the second terminal device and the first relay device.

[0307] Optionally, this third request message can also be sent by the PC5-S layer of the second terminal device instructing the PC5-RRC layer.

[0308] A possible implementation is that the third request message includes one or more of the following: the application layer identifier (APPlayer ID) of UE2, the application layer identifier of UE3, V2X service information (such as the V2X service identifier of interest), security information (such as security capabilities), and the destination layer 2 identifier (destination L2 ID) corresponding to UE3. So that the first relay device triggers the establishment of a unicast connection between the first relay device and the fourth terminal device according to the third request message.

[0309] Step 1002: The first relay device sends a unicast connection establishment request message for the fourth terminal device to the fourth terminal device.

[0310] Optionally, the PC5-RRC layer of the first relay device instructs the PC5-S layer to send this unicast connection establishment request message.

[0311] Step 1003: The fourth terminal device sends a unicast connection establishment acceptance message to the first relay device.

[0312] Step 1004: The second terminal device receives the third response message sent by the first relay device.

[0313] Among them, the third response message is used to indicate that the first relay device and the fourth terminal device have completed the establishment of the unicast connection.

[0314] In a possible implementation manner, the third response message may be a PC5-RRC message, and the PC5-RRC message is the PC5-RRC message of the unicast connection established between the first terminal device and the relay device. Optionally, the PC5-S layer of the first relay device instructs the PC5-RRC layer to send the third response message.

[0315] Considering the scenario of multiple hops in U2U relay, by indicating the establishment of a unicast connection between the relay device and a new destination terminal device through the already established unicast connection between UE2 and the relay device, the number of required unicast connections can be reduced, and the resource overhead can be reduced. Combining Figure 5 with the communication method in, the embodiments of the present application further provide a communication method. As Figure 11 shown, taking two hops as an example for illustration, the relay device may include a first relay device and a second relay device, and the first relay device and the second relay device jointly provide relay services for the second terminal device and the first terminal device. Among them, the first relay device establishes a communication link of a unicast connection with the first terminal device, and the second relay device establishes a communication link of a unicast connection with the second terminal device. Data can be forwarded between the first relay device and the second relay device to achieve multiple hops. When the second terminal device has obtained the identifier of the first terminal device, based on the communication links between UE2 and the first relay device and the second relay device, it requests the first relay device and the second relay device to establish a unicast connection with the fifth terminal device. Other scenarios of multiple hops can refer to this embodiment and will not be elaborated here. The specific steps may include:

[0316] Step 1101: The second terminal device sends a fourth request message to the second relay device.

[0317] Among them, the fourth request message is used to request the second relay device to establish a unicast connection with the fifth terminal device; the fifth terminal device may be one of the third terminal devices that have not established a communication connection with the second terminal device. For example, the fifth terminal device may be UE4. The fourth request message is used to instruct the first relay device and the second relay device to establish corresponding unicast connections with UE4.

[0318] In a possible implementation manner, the fourth request message is a PC5-RRC message; optionally, the PC5-RRC may be instructed by the PC5-S layer of the second terminal device to send the PC5-RRC layer.

[0319] In a possible implementation manner, the fourth request message includes at least one of the following: the application layer identifier of the second terminal device (for example, the application layer identifier of UE2), the application layer identifier of the fifth terminal device (for example, the application layer identifier of UE4), the service identifier, the security capability information, the identifier of the fifth terminal device (for example, the identifier of UE4).

[0320] In a possible implementation, the identifier of the fifth terminal device may be the layer 2 identifier of the fifth terminal device, the adaptation layer identifier of the fifth terminal device, or the identifier assigned by the first relay device to the fifth terminal device.

[0321] Step 1102: The second relay device forwards the fourth request message to the first relay device.

[0322] In a possible implementation, the fourth request message is a PC5-RRC message; optionally, the PC5-RRC may be sent by the PC5-S layer of the first relay device instructing the PC5-RRC layer.

[0323] Step 1103: The first relay device sends a unicast connection establishment request message to the fifth terminal device.

[0324] Step 1104: The fifth terminal device sends a unicast connection establishment acceptance message to the first relay device.

[0325] Step 1105: The first relay device sends a fourth response message to the second relay device.

[0326] For example, the first relay device forwards a unicast connection establishment acceptance message to the second relay device.

[0327] Step 1106: The second relay device sends a fourth response message to the second terminal device.

[0328] Among them, the fourth response message is used to indicate that the second relay device has completed the establishment of a unicast connection with the fifth terminal device.

[0329] In a possible implementation, the fourth response message may be a PC5-RRC message. Optionally, the fourth response message is generated by the PC5-S layer of the first relay device instructing the PC5-RRC layer.

[0330] Combined with Figure 3 , consider the scenario where UE2 communicates with multiple UEs (such as UE1, UE3, UE4) through the same relay device. UE2 performs U2Urelay communication with multiple destination terminal devices (UE1, UE3, UE4) through the same relay device. At this time, one unicast connection between UE2 and the relay device is associated with multiple unicast connections between the relay device and UE1, the relay device and UE3, and the relay device and UE4.

[0331] Since UE2 communicates with UE1, UE3, and UE4 through the corresponding relay device of the same unicast connection, and the PDCP entity is end-to-end corresponding (corresponding to the source terminal device and the destination terminal device), the PDCP entities for different UE1, UE3, and UE4 are different, and the configurations of these PDCP entities may be different. For example, UE2 has different QoS requirements when communicating with UE1, UE3, and UE4, so different PDCP entities need to be configured for their respective communication links. As Figure 12 shown, when UE2 communicates with UE1, the QoS is QoS1, and the corresponding PDCP entity that can be configured is PDCP1. When UE2 communicates with UE3, the QoS is QoS2, and the corresponding PDCP entity that can be configured is PDCP2. When UE4 communicates with UE2, the QoS is QoS3, and the corresponding PDCP entity that can be configured is PDCP3.

[0332] On the other hand, the RLC entity may be shared by different destination terminal devices. For example, UE1, UE3, and UE4 share an RLC entity. That is, when communicating between UE2 and UE1 through the first relay device, the RLC entity used is RLC2, and the RLC2 entity associates the identifier of UE2 and the second identifier of the first relay device. When communicating between UE3 and UE2 through the first relay device, the RLC entity used can also be RLC2, and the association relationship stored in the RLC2 entity is still the identifier of UE2 and the second identifier of the first relay device. When communicating between UE2 and UE4 through the first relay device, the RLC entity used can also be RLC2, and RLC2 associates the identifier of UE2 and the second identifier of the first relay device. The PDCP entities corresponding to different destination terminal devices are associated with different identifiers (the identifier of UE2 and the identifier of the corresponding destination terminal device). Therefore, there may be a situation where the same RLC entity is associated with multiple PDCP entities (corresponding to different destination terminal devices, such as UE1, UE3, and UE4), and these PDCP entities may correspond to different QoS requirements. So, it is necessary to comprehensively consider the QoS of multiple UEs to configure a reasonable RLC entity.

[0333] Combined with Figure 12 the scenario, considering that the second terminal device may not be able to obtain the identifiers of multiple end-to-end destination terminal devices, the second terminal device can only sense the relay device, resulting in the network where the terminal device is located can only allocate side-link data radio bearer configurations with the same performance for the destination terminal devices, and cannot allocate different configurations for different destination terminal devices, resulting in a relatively low unicast data transmission quality for different destination terminal devices. To achieve a more reasonable SLRB configuration for multiple destination terminal devices, as Figure 13As shown in the figure, an embodiment of the present application further provides a communication method. Here, taking the source terminal device as the second terminal device and the destination terminal device as the first terminal device as an example, the implementation manner in which the second terminal device requests the access network device to configure reasonable SLRB configurations for multiple destination terminal devices will be described. Among them, the first terminal device may include N third terminal devices. Combining Figure 3 As shown in the figure, the second terminal device may be UE2, and the third terminal devices may be UE1, UE3, and UE4. The specific steps may include:

[0334] Step 1301: The second terminal device determines a second request message.

[0335] Among them, the second request message may be used to carry QoS information corresponding to multiple destination terminal devices (for example, the second request message carries QoS information corresponding to UE1 and QoS information corresponding to UE3). Thus, after receiving the second request message, the access network device can configure SLRBs for multiple destination terminal devices based on the QoS information corresponding to the multiple destination terminal devices.

[0336] A possible implementation manner is that the second request message may be used to request the configuration of the SLRB configuration of the first terminal device.

[0337] Taking the first terminal device as a single terminal device as an example, the second request message may include: first QoS information, a second identifier of the first relay device, and first information.

[0338] Among them, the first QoS information is the QoS information corresponding to the first terminal device. The second identifier of the first relay device is used to identify the second communication link between the second terminal device and the first relay device. The first information has a corresponding relationship with the first QoS information, and the first information has a corresponding relationship with the second identifier.

[0339] It can be understood that the QoS information includes a QoS flow identifier (QoS flow ID) and / or a QoS profile (QoSprofile).

[0340] For example, the first information may be the unique identifier of the adaptation layer of the first terminal device, or the local identifier of the adaptation layer of the first terminal device, or the identifier of the PC5-S layer of the first terminal device, or the L2 ID of the first terminal device, or the QoS flow identifier.

[0341] Taking the example that the first terminal device includes multiple terminal devices, for instance, the first terminal device includes N third terminal devices. At this time, the first QoS information may include: M second QoS information. The second QoS information is the QoS information corresponding to the third terminal device. At this time, the first information may include: N second information, where N is a positive integer and M is a positive integer greater than or equal to N. There is a corresponding relationship between the second information and the second QoS information. The corresponding relationship among the second information, the second identifier, and the second QoS information may be as shown in Table 2 below.

[0342] Taking Table 2 as an example, the first information of UE1 may be the unique identifier adaption ID1 of the adaption layer of UE1, the first information of UE3 may be the unique identifier adaption ID3 of the adaption layer of UE3, and the first information of UE4 may be the unique identifier adaption ID4 of the adaption layer of UE4. Thus, the access network device may determine, based on the first QoS information and the first information, that the first QoS information is an SLRB configured for the second terminal device to communicate with the first terminal device through the first relay device. It should be noted that the first information may be information indicated by the upper layer (V2X layer or PC5-S layer) to the AS layer, or may be determined by the AS layer itself, which is not limited herein.

[0343] Table 2

[0344]

[0345] Step 1302: The second terminal device sends a second request message to the access network device.

[0346] Considering that UE1 is in the RRC connected state, the second request message may be an SUI message. Thus, through the SUI message, the QoS information corresponding to each destination terminal device is reported to the access network device. So that the access network device can distinguish the QoS information of different destination terminal devices (used to indicate whether the QoS information is for UE1 or UE3 or UE4).

[0347] Step 1303: The second terminal device receives a second response message from the access network device.

[0348] Among them, the second response message includes: the radio bearer configuration information corresponding to the first terminal device.

[0349] Considering the scenario where the first terminal device is a single terminal device, the second response message may include the radio bearer configuration information corresponding to the first terminal device. Considering the scenario where the first terminal device is N terminal devices, the radio bearer configuration information in the second response message may include X pieces of third radio bearer configuration information, where X is a positive integer less than or equal to M. That is, the access network device may configure M pieces of third radio bearer configuration information for N third terminal devices.

[0350] Taking the third terminal device as UE1 as an example, the third radio bearer configuration information of UE1 may include: the PDCP configuration information of UE1 and / or the SDAP configuration information, and the third radio bearer configuration information is associated with the QoS information of UE1; that is, the third radio bearer configuration information is determined based on the QoS information of UE1. The third radio bearer configuration information of UE1 may also include or be associated with: the RLC bearer configuration information shared by N third terminal devices; the RLC bearer configuration information is determined by the access network device based on the X pieces of QoS information corresponding to N third terminal devices. The RLC bearer configuration information is associated with the second identifier of the first relay device.

[0351] Taking the third terminal device as UE3 as an example, the third radio bearer configuration information of UE3 may include: the PDCP configuration information of UE3 and / or the SDAP configuration information, and the third radio bearer configuration information is associated with the QoS information of UE3; that is, the third radio bearer configuration information is determined based on the QoS information of UE3. The third radio bearer configuration information of UE3 may also include or be associated with: the RLC bearer configuration information shared by N third terminal devices; the RLC bearer configuration information is determined by the access network device based on the X pieces of QoS information corresponding to N third terminal devices. The RLC bearer configuration information is associated with the second identifier of the first relay device.

[0352] In one possible implementation, the access network device sends the X pieces of third radio bearers through a second response message. In another possible implementation, the access network device may also include the X pieces of third radio bearer configuration information in multiple second response messages to indicate the corresponding third radio bearers for N third terminal devices. This is not limited here.

[0353] Step 1304: The second terminal device communicates with the first terminal device through the first relay device on the radio bearer corresponding to the first terminal device.

[0354] Considering the scenario where the first terminal device is a single terminal device, the second terminal device may communicate with the first terminal device on the radio bearer corresponding to the first terminal device. Considering the scenario where the first terminal device is N terminal devices, the second terminal device may communicate with the corresponding third terminal device through the first relay device on the corresponding third radio bearer.

[0355] The following uses Mode c1 - Mode c3 as examples to illustrate the implementation methods of the second request message and the second response message in different scenarios.

[0356] In Mode c1, when the second terminal device and the first terminal device perform relay communication through the first relay device, the first QoS information may further include: a first QoS identifier.

[0357] Wherein, the first QoS identifier is used to indicate the QoS flow in the third terminal device, and the first QoS identifier does not correspond to the first information.

[0358] For example, the first QoS identifier may be a QoS flow identifier, and the QoS flow identifier can distinguish different QoS flows in each third terminal device. At this time, the QoS flow identifier of each third terminal device may not correspond to the layer 2 identifier of the third terminal device and the communication type cast type of the third terminal device, that is, different third terminal devices may correspond to the same QoS flow identifier. That is, the first QoS identifier of UE1 is QoS flow identifier 1, the first QoS identifier of UE3 is QoS flow identifier 1, and the first QoS identifier of UE4 is QoS flow identifier 1, and their corresponding relationships can be shown in Table 3.

[0359] Table 3

[0360]

[0361] Therefore, in the second response message sent by the access network device to the second terminal device, it is also necessary to include: the first QoS identifier and the first information, to indicate the third terminal device corresponding to the SLRB configuration in the second response message. Their corresponding relationships can be shown in Table 4.

[0362] Table 4

[0363]

[0364] In Mode c2, the first QoS information further includes: a first QoS identifier. At this time, the first QoS identifier corresponds to the first information.

[0365] In this mode, the first QoS identifier may also be a QoS flow identifier, and the QoS flow identifier can distinguish each third terminal device and the corresponding QoS information. For example, the second terminal device may establish a QoS flow identifier for each third terminal device after determining the QoS information of each third terminal device. At this time, the QoS flow identifier of each third terminal device may correspond to the layer 2 identifier of the third terminal device, the communication type cast type of the third terminal device, and the QoS information. That is, the first QoS identifier of UE1 is QoS flow identifier 1, the first QoS identifier of UE3 is QoS flow identifier 3, and the first QoS

[0366] It is identified as QoS flow identifier 4, and its corresponding relationship can be as shown in Table 5.

[0367] Table 5

[0368]

[0369] Therefore, in the second response message sent by the access network device to the second terminal device, only the first QoS identifier can be carried, that is, it can indicate the third terminal device corresponding to the SLRB configuration allocated in the second response message. Its corresponding relationship can be as shown in Table 6.

[0370] Table 6

[0371]

[0372] In method c3, in the radio bearer configuration information of the first terminal device sent by the access network device to the second terminal device, RLC configuration information can be carried or associated, and the RLC configuration information is associated with multiple PDCP entity configuration information. For example, the RLC bearer configuration includes a PDCP entity configuration index list SLRB-Uu-configindex-list. Its corresponding relationship can be as shown in Table 7.

[0373] Table 7

[0374]

[0375] Furthermore, in a possible scenario, to distinguish between the scenarios of relay communication and non-relay communication, corresponding characters can be set for the first information to distinguish whether the second terminal device and the first terminal device are in relay communication or direct communication.

[0376] For example, when the first information is zero, it can indicate that the second terminal device and the first terminal device are in direct communication. It is used to represent the QoS information corresponding to the first information, or that the first terminal device and the second terminal device corresponding to the first information are in direct communication, and the first terminal device and the second terminal device do not need to establish a U2U relay communication link through a relay device. When the first information is a non-zero value, it can indicate that the second terminal device and the first terminal device are in relay communication.

[0377] In another possible scenario, considering that when the second terminal device is not in the RRC connected state, it cannot request the SLRB configuration of the first terminal device from the access network device. At this time, the second terminal device can determine the SLRB configuration for the first terminal device based on its own settings. For example, when determining the configuration of the PDCP entity, only the QoS of a corresponding destination terminal device can be considered, that is, the PDCP entity is configured separately for each third terminal device. For example, when determining that the destination terminal devices shared on the unicast connection between the current second terminal device and the first relay device include UE1, UE3, and UE4, the PDCP1 corresponding to UE1 can be determined based on the QoS1 corresponding to UE1; the PDCP3 corresponding to UE3 can be determined based on the QoS3 corresponding to UE3; the PDCP4 corresponding to UE4 can be determined based on the QoS4 corresponding to UE4.

[0378] When determining the configuration of the RLC entity, the RLC configuration can be jointly determined according to the QoS of multiple destination terminal devices shared on the unicast connection between the current second terminal device and the first relay device. For example, when determining that the destination terminal devices shared on the unicast connection between the current second terminal device and the first relay device include UE1, UE3, and UE4, at this time, the RLC configuration can be jointly determined based on the QoS1 corresponding to UE1, the QoS2 corresponding to UE3, and the QoS3 corresponding to UE4.

[0379] Through the above method, when the second terminal device communicates with multiple destination terminal devices through a relay device, the second terminal device can report the first information to enable the access network device to report the QoS information for differentiating different destination terminal devices under the same relay device L2ID, so as to obtain a reasonable SLRB configuration (PDCP configuration, RLC bearer configuration, etc.), thereby better and more accurately ensuring the QoS of U2U relay communication and improving the communication performance between the second terminal device and the destination terminal device.

[0380] The following describes the apparatus for implementing the above method in the embodiments of the present application with reference to the accompanying drawings. Therefore, the content in the above text can be used in subsequent embodiments, and the repeated content will not be elaborated.

[0381] Figure 14 It is a schematic block diagram of a communication apparatus 1400 provided in an embodiment of the present application.

[0382] The communication device 1400 includes a processing module 1410 and a receiving module 1420. Optionally, the communication device 1400 may further include a transmitting module 1430. Exemplarily, the communication device 1400 may be a transmitting device or a receiving device. Exemplarily, the communication device 1400 may be a second communication device, and the second communication device may be a second terminal device, or a first terminal device, or a chip applied to the second terminal device or the first terminal device, or other combined devices, components, etc. having the functions of the above terminal devices. When the communication device 1400 is a terminal device, the receiving module 1420 or the transmitting module 1430 may be a transceiver, and the transceiver may include an antenna and a radio frequency circuit, etc., and the processing module 1410 may be a processor, such as a baseband processor, and one or more CPUs may be included in the baseband processor. When the communication device 1400 is a component having the functions of the above terminal devices, the receiving module 1420 or the transmitting module 1430 may be a radio frequency unit, and the processing module 1410 may be a processor, such as a baseband processor. When the communication device 1400 is a chip system, the receiving module 1420 or the transmitting module 1430 may be an input / output interface of the chip (such as a baseband chip), and the processing module 1410 may be a processor of the chip system, and may include one or more central processing units. It should be understood that the processing module 1410 in the embodiments of the present application may be implemented by a processor or processor-related circuit components, and the receiving module 1420 or the transmitting module 1430 may be implemented by a transceiver or transceiver-related circuit components.

[0383] For example, the processing module 1410 may be used to execute Figures 5 to 13 all operations other than the transceiver operations performed by the terminal device in the embodiments shown, such as step 502a or step 502b, and / or other processes for supporting the technologies described herein. The receiving module 1420 and the transmitting module 1430 may be used to execute Figures 5 to 13 all transceiver operations performed by the terminal device in the embodiments shown, and / or other processes for supporting the technologies described herein.

[0384] The receiving module 1420 and the transmitting module 1430 may be a functional module that can complete both the transmitting operation and the receiving operation. For example, the receiving module 1420 and the transmitting module 1430 may be used to execute Figures 5 to 13 all the transmitting operations and receiving operations performed by the terminal device in the embodiments shown. For example, when performing a transmitting operation, this module may be considered as the transmitting module 1430, and when performing a receiving operation, this module may be considered as the receiving module 1430; or, the receiving module 1420 and the transmitting module 1430 may also be two functional modules, and the transmitting module 1430 is used to complete the transmitting operation. For example, the transmitting module may be used to execute Figures 5 to 13For any of the embodiments shown, all the transmission operations performed by the terminal device, the receiving module 1420 is used to complete the receiving operations. For example, the receiving module 1420 can be used to execute Figures 5 to 13 All the receiving operations performed by the terminal device in the embodiments shown.

[0385] In a possible embodiment, the receiving module 1420 is used to receive a first message from a first relay device. The first message includes an identifier of a first terminal device. Wherein, the identifier of the first terminal device is: the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or an identifier assigned by the first relay device to the first terminal device.

[0386] The processing module 1410 is used to communicate with the first terminal device according to the identifier of the first terminal device.

[0387] In a possible implementation manner, the sending module 1430 is used to send a second message to the first relay device. The second message includes an identifier of a second terminal device. Wherein, the identifier of the second terminal device is: the layer 2 identifier of the second terminal device, the adaptation layer identifier of the second terminal device, or an identifier assigned by the first relay device to the second terminal device.

[0388] In a possible implementation manner, the first message or the second message is any one of the following: a unicast connection establishment request message, a unicast connection establishment acceptance message, a security activation command message, a security activation completion message, a PC5-RRC message, a PC5-S message.

[0389] Scenario 1, the communication device 1400 is a sending-end device.

[0390] In a possible implementation manner, the receiving module 1420 is used to obtain first data through a first protocol layer. The first data is data sent by a second terminal device to a first terminal device through a first relay device. The first data is associated with the identifier of the second terminal device and the identifier of the first terminal device.

[0391] Optionally, the processing module 1410 is used to determine second data according to the first data through the first protocol layer. The second data is data sent by a second terminal device to a first terminal device through a first relay device. The second data is associated with the identifier of the second terminal device and a second identifier of the first relay device.

[0392] Optionally, the first protocol layer is a packet data convergence protocol PDCP layer or an adaptation layer.

[0393] Scenario 2, the communication device 1400 is a receiving-end device.

[0394] A possible implementation, a receiving module 1420, configured to obtain third data through a second protocol layer; the third data is data received by a second terminal device from a first terminal device through a first relay device; the third data is associated with a first identifier of the first relay device and an identifier of the second terminal device.

[0395] Optionally, a processing module 1410, configured to determine fourth data according to the third data through the second protocol layer; the fourth data is data received by a second terminal device from a first terminal device through a first relay device; the fourth data is associated with an identifier of the first terminal device and an identifier of the second terminal device.

[0396] Optionally, the second protocol layer is: a Radio Link Control (RLC) layer or an adaptation layer.

[0397] A possible implementation, a sending module 1430, configured to send a first request message to an access network device, where the first request message is used to request first radio bearer configuration information corresponding to a first terminal device; the first request message includes: first QoS information and an identifier of the first terminal device; the first QoS information is QoS information corresponding to the first terminal device.

[0398] A possible implementation, the receiving module 1420 is further configured to receive first configuration information from the access network device; the first configuration information is first radio bearer configuration information corresponding to the first terminal device, and the first radio bearer is used for the second terminal device to send data to the first terminal device.

[0399] In another possible embodiment, a processing module 1410 is configured to determine a second request message; a sending module 1430 is configured to send the second request message to the access network device. The second request message includes: first QoS information, a second identifier of the first relay device, and first information; the first QoS information is QoS information corresponding to the first terminal device, the second identifier of the first relay device is used for the second terminal device to communicate with the first relay device, the first information and the first QoS information have a corresponding relationship, and the first information and the second identifier have a corresponding relationship.

[0400] A possible implementation, the first terminal device includes N third terminal devices, the first QoS information includes: M second QoS information, the first information includes: N second information, N is a positive integer, M is a positive integer greater than or equal to N; the second QoS information is QoS information corresponding to the third terminal device, and the second information and the second QoS information have a corresponding relationship.

[0401] A possible implementation, the receiving module 1420 is further configured to receive a second response message from the access network device, where the second response message includes: radio bearer configuration information corresponding to the first terminal device;

[0402] A processing module 1410 is configured to communicate with a first terminal device via a first relay device on a radio bearer corresponding to the first terminal device.

[0403] In a possible implementation, the radio bearer configuration information corresponding to the first terminal device includes X pieces of third radio bearer configuration information, where X is a positive integer less than or equal to N.

[0404] A processing module 1410 is configured to communicate with a corresponding third terminal device via a first relay device on a third radio bearer.

[0405] In a possible implementation, the first QoS information includes: a first QoS identifier, where the first QoS identifier does not correspond to the first information; the second response message further includes: the first QoS identifier and the first information.

[0406] In a possible implementation, the first QoS information includes: a first QoS identifier, where the first QoS identifier corresponds to the first information; the second response message further includes: the first QoS identifier.

[0407] In a possible implementation, the first information is one of the following: a local identifier of the adaptation layer of the first terminal device, a unique identifier of the adaptation layer of the first terminal device, an identifier of the PC5-S layer of the first terminal device, or an identifier of the layer 2 of the first terminal device.

[0408] In another embodiment, a sending module 1430 is further configured to send a third request message to the first relay device, where the third request message is a PC5-RRC message, and the third request message is used to request the first relay device to establish a unicast connection with a fourth terminal device, and the first terminal device and the second terminal device establish a unicast connection via the first relay device; a receiving module 1420 is further configured to receive a third response message sent by the first relay device, where the third response message is a PC5-RRC message, and the third response message is used to indicate that the first relay device has completed the establishment of the unicast connection with the fourth terminal device.

[0409] In a possible implementation, a receiving module 1420 is further configured to receive a fourth request message from a second relay device; the fourth request message is used to request the second terminal device to establish a unicast connection with a fifth terminal device via the second relay device; the fifth terminal device and the first terminal device establish a unicast connection via the second relay device; the fourth request message is a PC5-RRC message; a sending module 1430 is further configured to send a fourth response message via the second relay device; the fourth response message is used to indicate that the second terminal device has established a unicast connection with the fifth terminal device via the second relay device; the fourth response message is a PC5-RRC message.

[0410] In a possible implementation, the third request message or the fourth request message includes at least one of the following: the application identifier of the second terminal device, the application layer identifier of the fifth terminal device, the service identifier, the security capability information, and the identifier of the fifth terminal device.

[0411] In a possible implementation, the identifier of the fifth terminal device is the layer 2 identifier of the fifth terminal device, the adaptation layer identifier of the fifth terminal device, or the identifier assigned by the first relay device to the fifth terminal device.

[0412] In a possible implementation, the third request message is generated by the PC5-S layer instructing the PC5-RRC layer, and the third response message is generated by the PC5-S layer instructing the PC5-RRC layer; or, the fourth request message is generated by the PC5-S layer instructing the PC5-RRC layer, and the third response message is generated by the PC5-S layer instructing the PC5-RRC layer.

[0413] In another embodiment, the receiving module 1420 is further configured to receive, via the first radio bearer, a third request message from the first terminal device; the third request message is used to request the first relay device to establish a unicast connection with the fourth terminal device; the first radio bearer is the radio bearer between the first terminal device and the second terminal device; the third request message is a PC5-RRC message; the sending module 1430 is further configured to send, on the first radio bearer, a third response message to the first terminal device; the third response message is used to indicate that the first relay device and the fourth terminal device have completed the establishment of the unicast connection; the third response message is a PC5-RRC message.

[0414] In a possible implementation, the third request message is sent by the PC5-S layer instructing the PC5-RRC layer; the third response message is sent by the PC5-S layer instructing the PC5-RRC layer.

[0415] In a possible implementation, the third request message includes at least one of the following: the application identifier of the first terminal device, the application layer identifier of the fourth terminal device, the service identifier, the security capability information, and the identifier of the fourth terminal device.

[0416] In a possible implementation, the identifier of the fourth terminal device is the layer 2 identifier of the fourth terminal device, the adaptation layer identifier of the fourth terminal device, or the identifier assigned by the first relay device to the fourth terminal device.

[0417] In another embodiment, the communication device 1400 may also be a first communication device. Exemplarily, the communication device 1400 may be a relay device, and the relay device may be a terminal device or a network device. The communication device 1400 may also be a chip applied to the relay device or other combined devices, components, etc. having the functions of the above relay device. When the communication device 1400 is a relay device, the receiving module 1420 or the transmitting module 1430 may be a transceiver, and the transceiver may include an antenna and a radio frequency circuit, etc. The processing module 1410 may be a processor, such as a baseband processor, and one or more CPUs may be included in the baseband processor. When the communication device 1400 is a component having the functions of the above relay device, the receiving module 1420 or the transmitting module 1430 may be a radio frequency unit, and the processing module 1410 may be a processor, such as a baseband processor.

[0418] For example, the processing module 1410 may be used to execute Figures 5 to 13 all operations other than the transceiver operations performed by the first relay device in the embodiments shown, and / or other processes for supporting the technologies described herein. The receiving module 1420 and the transmitting module 1430 may be used to execute Figures 5 to 13 all transceiver operations performed by the first relay device in the embodiments shown, and / or other processes for supporting the technologies described herein.

[0419] The receiving module 1420 and the transmitting module 1430 may be a functional module that can complete both the transmitting operation and the receiving operation. For example, the receiving module 1420 and the transmitting module 1430 may be used to execute Figures 5 to 13 all the transmitting operations and receiving operations performed by the first relay device in the embodiments shown. For example, when performing the transmitting operation, this module may be considered as the transmitting module 1430, and when performing the receiving operation, this module may be considered as the receiving module 1430; alternatively, the receiving module 1420 and the transmitting module 1430 may also be two functional modules. The transmitting module 1430 is used to complete the transmitting operation. For example, the transmitting module may be used to execute Figures 5 to 13 all the transmitting operations performed by the first relay device in any one of the embodiments shown, and the receiving module 1420 is used to complete the receiving operation. For example, the receiving module 1420 may be used to execute Figures 5 to 13 all the receiving operations performed by the first relay device in the embodiments shown. The following takes the communication device 1400 as the first relay device as an example for illustration.

[0420] A processing module 1410 is configured to send a first message to a second terminal device via a sending module 1430. The first message includes an identifier of the first terminal device, and the identifier of the first terminal device is: the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or an identifier assigned by a first relay device to the first terminal device; the identifier of the first terminal device is used for the second terminal device to communicate with the first terminal device according to the identifier of the first terminal device.

[0421] The processing module 1410 is configured to send a second message to the first terminal device via the sending module 1430. The second message includes an identifier of the second terminal device, and the identifier of the second terminal device is: the layer 2 identifier of the second terminal device, the adaptation layer identifier of the second terminal device, or an identifier assigned by the first relay device to the second terminal device; the identifier of the second terminal device is used for the first terminal device to communicate with the second terminal device according to the identifier of the second terminal device.

[0422] A possible implementation, the processing module 1410 is configured to send a third message to a second relay device via the sending module 1430; the third message includes an identifier of the first terminal device; the second relay device provides relay services for the second terminal device and the first terminal device.

[0423] A possible implementation, the first message or the second message is any one of the following: a unicast connection establishment request message, a unicast connection establishment acceptance message, a security activation command message, a security activation completion message, a PC5-RRC message, a PC5-S message.

[0424] Based on the same concept as the above communication method, as Figure 15 shown, an embodiment of the present application further provides a communication device 1500. The communication device 1500 can be used to implement the method executed by the terminal device in the above method embodiment. The terminal device can be the first terminal device or the second terminal device. Reference can be made to the description in the above method embodiment, where the communication device 1500 can be a terminal device, or can be located in a terminal device, and can be a transmitting device or a receiving device.

[0425] The communication device 1500 includes one or more processors 1501. The processor 1501 can be a general-purpose processor or a special-purpose processor, etc. For example, it can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication device (such as a terminal device or a chip, etc.), execute software programs, and process data of software programs. The communication device 1500 can include a transceiver unit for implementing signal input (reception) and output (transmission). For example, the transceiver unit can be a transceiver, a radio frequency chip, etc.

[0426] The communication device 1500 includes one or more processors 1501, and the one or more processors 1501 can implement the methods executed by the terminal device in the above - shown embodiments.

[0427] Optionally, in addition to implementing the methods in the above - shown embodiments, the processor 1501 can also implement other functions. Optionally, in one implementation, the processor 1501 can execute a computer program to cause the communication device 1500 to execute the methods executed by the terminal device in the above - mentioned method embodiments. This computer program can be stored in whole or in part in the processor 1501, such as the computer program 1503, or can be stored in whole or in part in the memory 1502 coupled to the processor 1501, such as the computer program 1504, or can cause the communication device 1500 to execute the methods executed by the terminal device in the above - mentioned method embodiments through the cooperation of the computer programs 1503 and 1504.

[0428] In another possible implementation, the communication device 1500 can also include a circuit, and this circuit can implement the functions executed by the terminal device in the foregoing method embodiments.

[0429] In another possible implementation, the communication device 1500 can include one or more memories 1502, on which a computer program 1504 is stored. This computer program can be run on the processor to cause the communication device 1500 to execute the communication methods described in the above - mentioned method embodiments. Optionally, data can also be stored in the memory. Optionally, computer programs and / or data can also be stored in the processor. For example, the above - mentioned one or more memories 1502 can store the association or correspondence relationships described in the above - mentioned embodiments, or the relevant parameters or tables involved in the above - mentioned embodiments, etc. Among them, the processor and the memory can be set separately, or can be integrated or coupled together.

[0430] In another possible implementation, the communication device 1500 can further include a transceiver unit 1505. The processor 1501 can be referred to as a processing unit to control the communication device (terminal device). The transceiver unit 1505 can be referred to as a transceiver, a transceiver circuit, or a transceiver, etc., and is used to implement the transceiver of data or control signaling.

[0431] For example, if the communication device 1500 is a chip applied to a communication device or other combined devices, components, etc. with the functions of the above - mentioned communication device, the communication device 1500 can include a transceiver unit 1505.

[0432] In another possible implementation, the communication device 1500 may further include a transceiver unit 1505 and an antenna 1506. The processor 1501 may be referred to as a processing unit, which controls the communication device (terminal device). The transceiver unit 1505 may be referred to as a transceiver, a transceiver circuit, or a transceiver, etc., which is used to implement the transceiver function of the device through the antenna 1506.

[0433] The communication device 1500 of the embodiment of the present application can be used to implement the method performed by the relay device in the above method embodiment, and the relay device can be a network device or a terminal device. Please refer to the description in the above method embodiment, where the communication device 1500 can be a relay device, or can be located in a relay device, and can be a transmitting device or a receiving device.

[0434] The communication device 1500 includes one or more processors 1501. The processor 1501 may be a general-purpose processor or a dedicated processor, etc. For example, it may be a baseband processor or a central processing unit. The baseband processor may be used to process the communication protocol and the communication data, and the central processing unit may be used to control the communication device (such as a relay device or a chip, etc.), execute the software program, and process the data of the software program. The communication device 1500 may include a transceiver unit to realize the input (reception) and output (transmission) of the signal. For example, the transceiver unit may be a transceiver, a radio frequency chip, etc.

[0435] The communication device 1500 includes one or more processors 1501 , and the one or more processors 1501 can implement the method performed by the first relay device in the above-mentioned embodiment.

[0436] Optionally, in addition to implementing the methods in the embodiments shown above, the processor 1501 may also implement other functions. Optionally, in one implementation, the processor 1501 may execute a computer program so that the communication device 1500 executes the method executed by the first relay device in the above method embodiment. The computer program may be stored in whole or in part in the processor 1501, such as computer program 1503, or may be stored in whole or in part in a memory 1502 coupled to the processor 1501, such as computer program 1504, or the computer programs 1503 and 1504 may be used together to cause the communication device 1500 to execute the method executed by the first relay device in the above method embodiment.

[0437] In yet another possible implementation, the communication device 1500 may also include a circuit, which may implement the function performed by the first relay device in the aforementioned method embodiment.

[0438] In yet another possible implementation, the communication device 1500 may include one or more memories 1502, on which a computer program 1504 is stored. The computer program can be run on the processor, enabling the communication device 1500 to execute the communication method described in the above method embodiments. Optionally, data may also be stored in the memory. Optionally, the computer program and / or data may also be stored in the processor. For example, the above one or more memories 1502 may store the association or correspondence relationship described in the above embodiments, or relevant parameters or tables involved in the above embodiments. Among them, the processor and the memory can be provided separately, or integrated or coupled together.

[0439] In yet another possible implementation, the communication device 1500 may further include a transceiver unit 1505. The processor 1501 may be referred to as a processing unit to control the communication device (the first relay device). The transceiver unit 1505 may be referred to as a transceiver, a transceiver circuit, or a transceiver, etc., for implementing the transceiver of data or control signaling.

[0440] For example, if the communication device 1500 is a chip applied to a communication device or other combined devices, components, etc. with the functions of the above communication device, the communication device 1500 may include a transceiver unit 1505.

[0441] In yet another possible implementation, the communication device 1500 may further include a transceiver unit 1505 and an antenna 1506. The processor 1501 may be referred to as a processing unit to control the communication device (the first relay device). The transceiver unit 1505 may be referred to as a transceiver, a transceiver circuit, or a transceiver, etc., for implementing the transceiver function of the device through the antenna 1506.

[0442] It should be noted that the processor in the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. In the implementation process, the steps of the above method embodiments may be completed by the integrated logic circuit in the hardware of the processor or the computer program in the form of software. The above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The method steps disclosed in combination with the embodiments of the present application may be directly embodied as being executed and completed by the hardware decoding processor, or executed and completed by the combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0443] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and directrambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include but not be limited to these and any other suitable types of memory.

[0444] The embodiments of the present application further provide a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a computer, the method of any of the method embodiments applied to the first communication device or the second communication device is implemented.

[0445] The embodiments of the present application further provide a computer program product, and when the computer program product is executed by a computer, the method described in any of the method embodiments applied to the first communication device or the second communication device is implemented.

[0446] In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs. When the computer program is loaded and executed on a computer, the processes or functions according to the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer program may 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 program may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired manner (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a high-definition digital video disc (DVD)), or a semiconductor medium (such as a solid state disk (SSD)), etc.

[0447] An embodiment of the present application further provides a communication device, including a processor and an interface; the processor is configured to execute the method described in any of the above method embodiments applied to a relay device or a terminal device.

[0448] It should be understood that the above processing device may be a chip, and the processor may be implemented by hardware or software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor may be a general-purpose processor, which is implemented by reading software code stored in a memory. The memory may be integrated in the processor or located outside the processor and exist independently.

[0449] An embodiment of the present application provides a communication system. The communication system may include the above Figures 5 to 13 relay device and terminal device involved in the shown embodiments. The relay device is, for example, Figure 14 the communication device 1400 in Figure 15 or, Figure 14 the communication device 1500 in Figure 15 The terminal device is, for example,

[0450] The embodiments of the present application further provide a computer-readable storage medium storing a computer program, which, when executed by a computer, enables the computer to implement the Figures 5 to 13 processes related to relay devices or terminal devices in the embodiments shown above.

[0451] The embodiments of the present application further provide a computer program product for storing a computer program, which, when executed by a computer, enables the computer to implement the Figures 5 to 13 processes related to relay devices or terminal devices in the embodiments shown above.

[0452] The embodiments of the present application provide a communication method and apparatus, aiming to reduce the resource overhead of U2U relay and improve communication quality. Among them, the method and the apparatus are based on the same or similar concepts of the same technology. Since the principles of the method and the apparatus for solving problems are similar, the implementation of the apparatus and the method can be referred to each other, and the repeated parts will not be described again.

[0453] In the description of the embodiments of the present application, "and / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. At least one involved in the present application refers to one or more; a plurality refers to two or more. In addition, it should be understood that in the description of the present application, terms such as "first", "second", and "third" are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying an order. The reference to "one embodiment" or "some embodiments" in this specification means that a specific feature, structure, or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in other embodiments" and the like that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

Claims

1. A communication method, applied to a second terminal device, characterized in that including: receiving a first message from a first relay device, where the first message includes an identifier of a first terminal device; the identifier of the first terminal device being: the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or an identifier assigned by the first relay device to the first terminal device; communicating with the first terminal device according to the identifier of the first terminal device; a second protocol layer obtaining third data; the third data being data received by the second terminal device from the first terminal device through the first relay device; the third data being associated with a first identifier of the first relay device and an identifier of the second terminal device; the second protocol layer determining fourth data according to the third data; the fourth data being data received by the second terminal device from the first terminal device through the first relay device; the fourth data being associated with an identifier of the first terminal device and an identifier of the second terminal device; wherein the second protocol layer is: a radio link control (RLC) layer or an adaptation layer.

2. The method according to claim 1, wherein The method further includes: sending a second message to the first relay device; the second message including: an identifier of the second terminal device; wherein the identifier of the second terminal device is: the layer 2 identifier of the second terminal device, the adaptation layer identifier of the second terminal device, or an identifier assigned by the first relay device to the second terminal device.

3. The method according to claim 2, characterized in that, The first message or the second message is any one of the following: a unicast connection establishment request message, a unicast connection establishment acceptance message, a security activation command message, a security activation completion message, a PC5-RRC message, a PC5-S message.

4. The method according to any one of claims 1 to 3, characterized in that, The method further includes: a first protocol layer obtaining first data; the first data being data sent by the second terminal device to the first terminal device through the first relay device; the first data being associated with an identifier of the second terminal device and an identifier of the first terminal device.

5. The method according to claim 4, wherein The method further includes: the first protocol layer determining second data according to the first data; the second data being data sent by the second terminal device to the first terminal device through the first relay device; the second data being associated with an identifier of the second terminal device and a second identifier of the first relay device.

6. The method according to claim 4, wherein The first protocol layer is a packet data convergence protocol (PDCP) layer or an adaptation layer.

7. The method according to any one of claims 1 to 3, characterized in that The method further includes: sending a first request message to an access network device, the first request message being used to request first radio bearer configuration information corresponding to the first terminal device; the first request message including: first QoS information and an identifier of the first terminal device; the first QoS information being QoS information corresponding to the first terminal device.

8. The method according to claim 7, characterized in that The method further includes: receiving first configuration information from the access network device; the first configuration information being first radio bearer configuration information corresponding to the first terminal device, the first radio bearer configuration information being used for the second terminal device to send data to the first terminal device.

9. A communication method, characterized in that, including: Send a first message to a second terminal device, where the first message includes an identifier of the first terminal device, and the identifier of the first terminal device is: the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or an identifier assigned by a first relay device to the first terminal device; The identifier of the first terminal device is used for the second terminal device to communicate with the first terminal device according to the identifier of the first terminal device. The communication includes: the second protocol layer of the second terminal device obtains third data, where the third data is data received by the second terminal device from the first terminal device through the first relay device, and the third data is associated with a first identifier of the first relay device and an identifier of the second terminal device; the second protocol layer of the second terminal device determines fourth data according to the third data, where the fourth data is data received by the second terminal device from the first terminal device through the first relay device, and the fourth data is associated with the identifier of the first terminal device and the identifier of the second terminal device; where the second protocol layer is: a radio link control (RLC) layer or an adaptation layer; Send a second message to the first terminal device, where the second message includes an identifier of the second terminal device, and the identifier of the second terminal device is: the layer 2 identifier of the second terminal device, the adaptation layer identifier of the second terminal device, or an identifier assigned by the first relay device to the second terminal device; the identifier of the second terminal device is used for the first terminal device to communicate with the second terminal device according to the identifier of the second terminal device.

10. The method according to claim 9, characterized in that The method further includes: Send a third message to a second relay device; the third message includes the identifier of the first terminal device; the second relay device provides a relay service for the second terminal device and the first terminal device; Or, send a fourth message to the second relay device; the fourth message includes the identifier of the second terminal device.

11. The method according to claim 9 or 10, characterized in that, The first message or the second message is any one of the following: A unicast connection establishment request message, a unicast connection establishment acceptance message, a security activation command message, a security activation completion message, a PC5-RRC message, a PC5-S message.

12. A communication device is applied to a second terminal device, characterized in that, Including: A receiving module, configured to receive a first message from a first relay device, where the first message includes an identifier of a first terminal device; The identifier of the first terminal device is: the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or an identifier assigned by the first relay device to the first terminal device; A processing module, configured to communicate with the first terminal device according to the identifier of the first terminal device; The receiving module is further configured to obtain third data through a second protocol layer; the third data is data received by the second terminal device from the first terminal device through the first relay device; the third data is associated with a first identifier of the first relay device and an identifier of the second terminal device; The processing module is configured to determine fourth data according to the third data through a second protocol layer; the fourth data is data received by the second terminal device from the first terminal device through the first relay device; the fourth data is associated with the identifier of the first terminal device and the identifier of the second terminal device. Wherein, the second protocol layer is: a Radio Link Control (RLC) layer or an adaptation layer.

13. The device according to claim 12, characterized in that, The apparatus further includes: A sending module, configured to send a second message to the first relay device; the second message includes: the identifier of the second terminal device; wherein, the identifier of the second terminal device is: the layer 2 identifier of the second terminal device, the adaptation layer identifier of the second terminal device, or an identifier allocated by the first relay device for the second terminal device.

14. The device according to claim 13, characterized in that, The first message or the second message is any one of the following: a unicast connection establishment request message, a unicast connection establishment acceptance message, a security activation command message, a security activation completion message, a PC5-RRC message, a PC5-S message.

15. The device according to any one of claims 12 - 14, characterized in that, The receiving module is further configured to obtain first data through a first protocol layer; the first data is data sent by the second terminal device to the first terminal device through the first relay device; the first data is associated with the identifier of the second terminal device and the identifier of the first terminal device.

16. The device according to claim 15, wherein The processing module is configured to determine second data according to the first data through the first protocol layer; the second data is data sent by the second terminal device to the first terminal device through the first relay device. The second data is associated with the identifier of the second terminal device and the second identifier of the first relay device.

17. The device according to claim 15, characterized in that, The first protocol layer is a Packet Data Convergence Protocol (PDCP) layer or an adaptation layer.

18. The device according to any one of claims 12-14, characterized in that, The apparatus further includes: A sending module, configured to send a first request message to an access network device, where the first request message is used to request first radio bearer configuration information corresponding to the first terminal device; the first request message includes: first QoS information and the identifier of the first terminal device; the first QoS information is QoS information corresponding to the first terminal device.

19. The device according to claim 18, characterized in that, The receiving module is further configured to receive first configuration information from the access network device; the first configuration information is first radio bearer configuration information corresponding to the first terminal device, and the first radio bearer configuration information is used for the second terminal device to send data to the first terminal device.

20. A communication device, characterized in that, It includes: A processing module, configured to send a first message to a second terminal device through the sending module, where the first message includes the identifier of the first terminal device, and the identifier of the first terminal device is: the layer 2 identifier of the first terminal device, the adaptation layer identifier of the first terminal device, or an identifier allocated by the first relay device for the first terminal device. The identifier of the first terminal device is used for the second terminal device to communicate with the first terminal device according to the identifier of the first terminal device. The communication includes: the second protocol layer of the second terminal device obtains third data, where the third data is data received by the second terminal device from the first terminal device through the first relay device, and the third data is associated with the first identifier of the first relay device and the identifier of the second terminal device; the second protocol layer of the second terminal device determines fourth data according to the third data, where the fourth data is data received by the second terminal device from the first terminal device through the first relay device, and the fourth data is associated with the identifier of the first terminal device and the identifier of the second terminal device; wherein, the second protocol layer is: the Radio Link Control (RLC) layer or the adaptation layer; The processing module is configured to send a second message to the first terminal device through the sending module. The second message includes the identifier of the second terminal device, and the identifier of the second terminal device is: the layer 2 identifier of the second terminal device, the adaptation layer identifier of the second terminal device, or the identifier assigned by the first relay device to the second terminal device; the identifier of the second terminal device is used for the first terminal device to communicate with the second terminal device according to the identifier of the second terminal device.

21. The device according to claim 20, characterized in that, The processing module is configured to send a third message to the second relay device through the sending module; the third message includes the identifier of the first terminal device; the second relay device provides relay services for the second terminal device and the first terminal device; Alternatively, the processing module is configured to send a fourth message to the second relay device through the sending module; the fourth message includes the identifier of the second terminal device; the second relay device provides relay services for the second terminal device and the first terminal device.

22. The device according to claim 20 or 21, characterized in that, The first message or the second message is any one of the following: Unicast connection establishment request message, unicast connection establishment acceptance message, security activation command message, security activation completion message, PC5-RRC message, PC5-S message.

23. A communication device, characterized in that, Comprising a processor, the processor is coupled to at least one memory, and the processor is configured to read the computer program stored in the at least one memory to execute the method according to any one of claims 1 to 8.

24. A communication device, characterized in that, Comprising a processor, the processor is coupled to at least one memory, and the processor is configured to read the computer program stored in the at least one memory to execute the method according to any one of claims 9 to 11.

25. A computer-readable storage medium, characterized in that, Comprising a computer program, when the computer program runs on a computer, it causes the computer to execute the method according to any one of claims 1 to 8, or causes the computer to execute the method according to any one of claims 9 to 11.

26. A computer program product, characterized in that, When the computer program product runs on a processor, it causes the processor to execute the method according to any one of claims 1 to 8, or causes the processor to execute the method according to any one of claims 9 to 11.

27. A chip, characterized in that, Comprising a processor and a communication interface, the processor is configured to read instructions to execute the method according to any one of claims 1 to 8, or execute the method according to any one of claims 9 to 11.

28. A communication system, characterized in that, Comprising a communication device according to any one of claims 12 to 19, or, a communication device according to claim 23, and comprising a communication device according to any one of claims 20 to 22, or, a communication device according to claim 24.

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