Communication method, device and system

Abstract

The embodiment of the invention discloses a communication method, device and system, relates to the technical field of communication, and can enable remote equipment to sense relay equipment outside adjacent hops. The method comprises the steps that a first message is sent, the first message is used for indicating that a relay service between a second terminal device and a network device is supported to be provided for the second terminal device, and the first terminal device and the second terminal device are relayed through at least one third terminal device; receiving a second message, wherein the second message is used for indicating to establish unicast connection between the second terminal equipment and the first terminal equipment; wherein the unicast connection is established through at least one third terminal device. The embodiment of the invention is applied to a relay process.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of communication technologies, and in particular, to a communication method, apparatus, and system. Background Art

[0002] In a scenario where a remote device accesses a network device through a multi-hop relay device, since the remote device only establishes a direct connection with the relay device of its adjacent hop, the remote device can only perceive the relay device of its adjacent hop and cannot perceive the relay devices of other hops. Summary of the Invention

[0003] Embodiments of the present application provide a communication method and apparatus, which can enable a remote device to perceive relay devices other than adjacent hops.

[0004] To achieve the above object, the present application provides the following technical solutions:

[0005] In a first aspect, a communication method is provided. This method can be executed by a first terminal device, or by components of the first terminal device, such as a processor, chip, or chip system of the first terminal device, etc., and can also be implemented by a logic module or software that can implement all or part of the first terminal device. Hereinafter, an example in which this method is executed by the first terminal device will be used for description. The communication method includes: sending a first message, where the first message is used to indicate: supporting providing relay services between the second terminal device and the network device, and relaying between the first terminal device and the second terminal device through at least one third terminal device; receiving a second message, where the second message is used to indicate establishing a unicast connection between the second terminal device and the first terminal device; wherein the unicast connection is established through at least one third terminal device.

[0006] The present application provides a communication method. In a case where the second terminal device is connected to the first terminal device through multi-hop relay, a unicast connection is established between the first terminal device directly connected to the network device and the second terminal device, so that the second terminal device can directly perceive the first terminal device directly connected to the network device.

[0007] In a possible implementation, the first message is used to indicate, including: the first message includes first indication information and / or second indication information, and the first indication information and / or second indication information are used to indicate: supporting providing relay services for the second terminal device, and relaying between the first terminal device and the second terminal device through at least one third terminal device.

[0008] Based on this, the first message can indicate the relay capability of the first terminal device through the carried first indication information and / or second indication information, so that other devices can determine the relay capability of the first terminal device according to the first indication information and / or second indication information in the first message after receiving the first message.

[0009] In a possible implementation, the second message includes one or more of the following: the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device.

[0010] Based on this, based on the second message, the first terminal device can determine the terminals between the first terminal device and the second terminal device and / or the hop count information between the first terminal device and the second terminal device. Based on this information, the first terminal device can determine whether to establish a unicast connection with the second terminal device.

[0011] In a possible implementation, the second message includes: the first indication information and / or the second indication information, and the first indication information and / or the second indication information is used to indicate: supporting the provision of relay services for the second terminal device, and relaying between the first terminal device and the second terminal device through at least one third terminal device.

[0012] Based on this, the first terminal device can, based on the first indication information and / or the second indication information in the second message, determine that the unicast connection established this time is a unicast connection for providing multi-hop relay services for the second terminal device.

[0013] In a possible implementation, the method further includes: receiving a third message; the third message is used to request the provision of relay services.

[0014] Based on this, the first terminal device can send the first message after receiving the third message for requesting the provision of relay services for the second terminal device, saving the resource overhead of the first terminal device for sending the first message.

[0015] In a possible implementation, the third message includes one or more of the following: the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device.

[0016] Based on this, the first terminal device can determine the terminals between the first terminal device and the second terminal device and / or the hop count information between the first terminal device and the second terminal device. Based on this information, the first terminal device can determine whether to provide the relay services required by the second terminal device.

[0017] In a possible implementation, the third message includes: the third indication information and / or the fourth indication information; the third indication information and / or the fourth indication information is used to request the provision of relay services for the second terminal device, and relaying between the first terminal device and the second terminal device through at least one third terminal device.

[0018] Based on this, the first terminal device may determine the relay service that needs to provide multi-hop relay for the second terminal device this time based on the third indication information and / or the fourth indication information in the third message.

[0019] In a possible implementation, the method further includes: receiving a first data packet; the first data packet includes one or more of the following: first data or a first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device; sending a second data packet to a network device; the second data packet includes one or more of the following: first data, or a second local identifier; the second local identifier is used to identify the second terminal device between the first terminal device and the network device.

[0020] Based on this, the first terminal device may, during the uplink transmission, adjust the first data packet transmitted between the first terminal device and the second terminal device to the second data packet transmitted between the first terminal device and the network device. Thereby enabling the first terminal device to send the first data in the data packet to the network device.

[0021] In a possible implementation, the first data packet further includes a first identifier, and the first identifier is used to identify the radio bearer corresponding to the data of the second terminal device transmitted between the first terminal device and the second terminal device.

[0022] Based on this, the first terminal device may determine the radio bearer corresponding to the first data according to the first identifier in the first data packet.

[0023] In a possible implementation, the second data packet further includes a second identifier, and the second identifier is used to identify the radio bearer corresponding to the data of the second terminal device transmitted between the network device and the first terminal device.

[0024] Based on this, the first terminal device may send the second data packet according to the radio bearer identified by the second identifier in the second data packet.

[0025] In a possible implementation, the method further includes: determining a first configuration, the first configuration includes a second local identifier, and the first configuration is used to send the second data packet.

[0026] Based on this, the first terminal device may determine the second local identifier based on the first configuration, and adjust the first data packet to the second data packet based on the second local identifier.

[0027] In a possible implementation, the method further includes: sending the second data packet to the network device based on the first RLC channel indicated in the first configuration, and the first RLC channel is a channel associated with the radio bearer corresponding to the first data.

[0028] Based on this, the first terminal device may determine a channel for transmitting the first data between the first terminal device and the network device according to the first configuration, and transmit a second data packet on this channel.

[0029] In a possible implementation, the method further includes: receiving a first configuration from the network device.

[0030] Based on this, the first terminal device may obtain the first configuration from the network device, reducing the resources required for the first terminal device to determine the first configuration.

[0031] In a possible implementation, the method further includes: receiving a third data packet from the network device; the third data packet includes one or more of the following: second data, or a second local identifier; the second local identifier is used to identify a second terminal device between the first terminal device and the network device; sending a fourth data packet; the fourth data packet includes one or more of the following: second data, or a first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

[0032] Based on this, the first terminal device may, during downlink transmission, adjust the third data packet transmitted between the network device of the first terminal device to the fourth data packet transmitted between the second terminal device of the first terminal device. Thereby enabling the first terminal device to send the second data in the data packet to the second terminal device.

[0033] In a possible implementation, the third data packet further includes a second identifier, and the second identifier is used to identify a radio bearer corresponding to the data of the second terminal device transmitted between the network device and the first terminal device.

[0034] Based on this, the first terminal device may determine the radio bearer corresponding to the second data between the network device and the first terminal device according to the second identifier in the third data packet.

[0035] In a possible implementation, the fourth data packet further includes a first identifier, and the first identifier is used to identify a radio bearer corresponding to the data of the second terminal device transmitted between the first terminal device and the second terminal device.

[0036] Based on this, the first terminal device may send the fourth data packet according to the radio bearer identified by the first identifier in the fourth data packet.

[0037] In a possible implementation, the method further includes: determining a second configuration, where the second configuration includes a first local identifier, and the second configuration is used to send the fourth data packet.

[0038] Based on this, the first terminal device can determine a first local identifier based on the second configuration, and adjust the third data packet to a fourth data packet based on the first local identifier.

[0039] In a possible implementation, the method further includes: sending the fourth data packet based on a second RLC channel indicated in the second configuration, where the second RLC channel is a channel associated with a radio bearer corresponding to the fourth data.

[0040] Based on this, the first terminal device can determine a channel for transmitting the second data between the first terminal device and the second terminal device based on the second configuration, and transmit the fourth data packet on this channel.

[0041] In a possible implementation, the second configuration is a configuration determined based on downlink QoS information between the first terminal device and an adjacent terminal device.

[0042] Based on this, when the first terminal device transmits downlink data based on the second configuration, it can meet the downlink QoS requirements between the first terminal device and the adjacent terminal device.

[0043] In a possible implementation, the method further includes: receiving downlink QoS information between the first terminal device and the second terminal device; determining the second configuration based on the downlink QoS information between the first terminal device and the second terminal device.

[0044] Based on this, the first terminal device can determine, from the downlink QoS information between the first terminal device and the second terminal device, the downlink QoS information of one hop of the first terminal device in the downlink direction.

[0045] In a possible implementation, determining the second configuration based on the downlink QoS information between the first terminal device and the second terminal device includes: determining the downlink QoS information between the first terminal device and the adjacent terminal device based on the downlink QoS information between the first terminal device and the second terminal device; determining the second configuration based on the downlink QoS information between the first terminal device and the adjacent terminal device.

[0046] Based on this, the first terminal device can independently determine the second configuration that meets the downlink QoS requirements between the first terminal device and the adjacent terminal device.

[0047] In a possible implementation, determining the downlink QoS information between the first terminal device and the adjacent terminal device based on the downlink QoS information between the first terminal device and the second terminal device includes: sending the downlink QoS information between the first terminal device and the second terminal device to the adjacent terminal device; receiving the downlink QoS information between the first terminal device and the adjacent terminal device from the adjacent terminal device.

[0048] Based on this, the first terminal device can independently obtain a second configuration from an adjacent terminal device that meets the downlink QoS requirements between the first terminal device and the adjacent terminal device.

[0049] In a second aspect, a communication method is provided. This method can be executed by a first device, or by components of the first device, such as the processor, chip, or chip system of the first device, or can also be implemented by a logic module or software that can implement all or part of the first device. Hereinafter, an example will be given with the method being executed by the first device. The first device includes a second terminal device or a third terminal device; the communication method includes: receiving a fourth message, where the fourth message is used to indicate: supporting providing a relay service between the second terminal device and a network device, and relaying between the first terminal device and the second terminal device through at least one third terminal device; sending a fifth message, where the fifth message is used to indicate establishing a unicast connection between the second terminal device and the first terminal device; wherein, the unicast connection is established through at least one third terminal device.

[0050] In a possible implementation manner, the fourth message is used to indicate, including: the fourth message includes first indication information and / or second indication information, and the first indication information and / or second indication information is used to indicate: supporting providing a relay service for the second terminal device, and relaying between the first terminal device and the second terminal device through at least one third terminal device.

[0051] In a possible implementation manner, the fifth message includes one or more of the following: the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device.

[0052] In a possible implementation manner, the fifth message includes: first indication information and / or second indication information, and the first indication information and / or second indication information is used to indicate: supporting providing a relay service for the second terminal device, and relaying between the first terminal device and the second terminal device through at least one third terminal device.

[0053] In a possible implementation manner, the method further includes: sending a sixth message; the sixth message is used to request providing a relay service.

[0054] In a possible implementation manner, the sixth message includes: third indication information and / or fourth indication information; the third indication information and / or fourth indication information is used to request providing a relay service for the second terminal device, and relaying between the first terminal device and the second terminal device through at least one third terminal device.

[0055] In a possible implementation, the method is applied to a fourth terminal device. The sixth message includes one or more of the following: the identifier of the fourth terminal device, the identifiers of one or more third terminal devices between the fourth terminal device and the second terminal device, or the hop count information between the fourth terminal device and the second terminal device. The fourth terminal device is one of at least one third terminal device.

[0056] In a possible implementation, the method further includes: sending a first data packet; the first data packet includes one or more of the following: first data, or a first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

[0057] In a possible implementation, the first data packet further includes a first identifier, and the first identifier is used to identify the radio bearer corresponding to the data of the second terminal device transmitted between the first terminal device and the second terminal device.

[0058] In a possible implementation, the method is applied to a fourth terminal device, and the fourth terminal device is one of at least one third terminal device; the method further includes: receiving a fifth data packet, and generating a first data packet according to the fifth data packet, where the fifth data packet includes first data, or a first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

[0059] In a possible implementation, the method further includes: determining a third configuration, where the third configuration includes a first local identifier, and the third configuration is used to send the first data packet.

[0060] In a possible implementation, it includes: sending the first data packet based on the third RLC channel indicated in the third configuration; the third RLC channel is a channel associated with the radio bearer corresponding to the first data.

[0061] In a possible implementation, the third configuration is a configuration determined based on the uplink QoS information between the first device and the next-hop terminal device in the uplink direction.

[0062] In a possible implementation, the method further includes: obtaining the uplink QoS information between the first device and the first terminal device; based on the uplink QoS information between the first device and the first terminal device, determining the uplink QoS information between the first device and the next-hop terminal device in the uplink direction.

[0063] In a possible implementation, the method includes: receiving the uplink QoS information between the first device and the next-hop terminal device in the uplink direction.

[0064] In a possible implementation, the method further includes: receiving a fourth data packet, where the fourth data packet includes one or more of the following: first data, or a first local identifier; where the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

[0065] In a possible implementation, the fourth data packet further includes a first identifier, where the first identifier is used to identify the radio bearer corresponding to the data of the second terminal device transmitted between the first terminal device and the second terminal device.

[0066] In a possible implementation, the method is applied to a fourth terminal device, and the fourth terminal device is a third terminal device among at least one third terminal device; the method further includes: sending a sixth data packet, where the sixth data packet includes one or more of the following: second data, or a first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

[0067] In a possible implementation, the method further includes: determining a fourth configuration, where the fourth configuration includes a first local identifier, and the fourth configuration is used to send the sixth data packet.

[0068] In a possible implementation, sending the sixth data packet includes: sending the sixth data packet based on a fourth RLC channel indicated in the fourth configuration; the fourth RLC channel is a channel associated with the radio bearer corresponding to the fourth data.

[0069] In a possible implementation, the fourth configuration is a configuration determined based on the downlink QoS information between the fourth terminal device and the next-hop terminal device in the downlink direction.

[0070] In a possible implementation, the method further includes: receiving the downlink QoS information between the fourth terminal device and the next-hop terminal device in the downlink direction.

[0071] In a possible implementation, the method further includes: obtaining the downlink QoS information between the fourth terminal device and the second terminal device; based on the downlink QoS information between the fourth terminal device and the second terminal device, determining the downlink QoS information between the fourth terminal device and the next-hop terminal device in the downlink direction.

[0072] In a third aspect, a communication method is provided. This method can be executed by a third terminal device, or by components of the third terminal device, such as a processor, a chip, or a chip system of the third terminal device, etc., and can also be implemented by a logic module or software that can implement all or part of the third terminal device. Hereinafter, an example in which this method is executed by the third terminal device will be described. The communication method includes: sending a fourth message, where the fourth message is used to indicate: supporting providing a relay service between the second terminal device and the network device, and relaying between the first terminal device and the second terminal device through at least one third terminal device; receiving a fifth message, where the fifth message is used to indicate establishing a unicast connection between the second terminal device and the first terminal device; wherein, the unicast connection is established through at least one third terminal device.

[0073] In a possible implementation, the fourth message is used to indicate, including: the fourth message includes first indication information and / or second indication information, and the first indication information and / or second indication information are used to indicate: supporting providing a relay service for the second terminal device, and relaying between the first terminal device and the second terminal device through at least one third terminal device.

[0074] In a possible implementation, the fifth message includes one or more of the following: the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device.

[0075] In a possible implementation, the fifth message includes: first indication information and / or second indication information, and the first indication information and / or second indication information are used to indicate: supporting providing a relay service for the second terminal device, and relaying between the first terminal device and the second terminal device through at least one third terminal device.

[0076] In a fourth aspect, a communication method is provided. This method can be executed by a network device, or by components of the network device, such as a processor, a chip, or a chip system of the network device, etc., and can also be implemented by a logic module or software that can implement all or part of the network device. Hereinafter, an example in which this method is executed by the network device will be described. The communication method includes: obtaining QoS information between the first terminal device and the second terminal device; sending the QoS information between the first terminal device and the second terminal device.

[0077] In a possible implementation, the QoS information between the first terminal device and the second terminal device includes: uplink QoS information between the first terminal device and the second terminal device, and / or downlink QoS information between the first terminal device and the second terminal device.

[0078] In a possible implementation, sending QoS information between a first terminal device and a second terminal device includes: sending the downlink QoS information between the first terminal device and the second terminal device to the first terminal device.

[0079] In a possible implementation, sending QoS information between a first terminal device and a second terminal device includes: sending the uplink QoS information between the first terminal device and the second terminal device to the second terminal device.

[0080] In a possible implementation, the method further includes: sending a first configuration to the first terminal device; the first configuration is determined based on the QoS information between the first terminal device and the network device.

[0081] In a possible implementation, the method further includes: sending a second configuration to the first terminal device; the second configuration is determined based on the QoS information between the first terminal device and an adjacent terminal device.

[0082] In a fifth aspect, a communication method is provided. This method can be executed by a first terminal device, or by components of the first terminal device, such as the processor, chip, or chip system of the first terminal device, etc., and can also be implemented by a logic module or software that can implement all or part of the first terminal device. The following takes the example of the method being executed by the first terminal device for illustration. The communication method includes: determining a first configuration, and sending a second data packet according to the first configuration. The first configuration includes a second local identifier, and the first configuration is used to send the second data packet. The second data packet includes one or more of the following: first data, or the second local identifier; the second local identifier is used to identify the second terminal device between the first terminal device and the network device, and the first terminal device and the second terminal device are relayed through at least one third terminal device.

[0083] In a possible implementation, sending the second data packet according to the first configuration includes: sending the second data packet to the network device based on the first RLC channel indicated in the first configuration, and the first RLC channel is a channel associated with the radio bearer corresponding to the first data.

[0084] In a possible implementation, the method further includes: receiving the first configuration from the network device.

[0085] In a sixth aspect, a communication method is provided. This method can be executed by a first terminal device, or by components of the first terminal device, such as a processor, a chip, or a chip system of the first terminal device, etc., and can also be implemented by a logic module or software that can implement all or part of the first terminal device. Hereinafter, an example in which this method is executed by the first terminal device will be described. The communication method includes: determining a second configuration, and sending a fourth data packet according to the second configuration. The second configuration includes a first local identifier, and the second configuration is used to send the fourth data packet; the fourth data packet includes one or more of the following: second data, or the first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device, and the first terminal device and the second terminal device are relayed through at least one third terminal device.

[0086] In a possible implementation manner, sending the fourth data packet according to the second configuration includes: sending the fourth data packet based on a second RLC channel indicated in the second configuration, where the second RLC channel is a channel associated with a radio bearer corresponding to the fourth data.

[0087] In a possible implementation manner, the second configuration is a configuration determined based on downlink QoS information between the first terminal device and an adjacent terminal device.

[0088] In a possible implementation manner, determining the second configuration includes: receiving downlink QoS information between the first terminal device and the second terminal device; determining the second configuration based on the downlink QoS information between the first terminal device and the second terminal device.

[0089] In a possible implementation manner, determining the second configuration based on the downlink QoS information between the first terminal device and the second terminal device includes: determining downlink QoS information between the first terminal device and an adjacent terminal device based on the downlink QoS information between the first terminal device and the second terminal device; determining the second configuration based on the downlink QoS information between the first terminal device and the adjacent terminal device.

[0090] In a possible implementation manner, determining the downlink QoS information between the first terminal device and an adjacent terminal device based on the downlink QoS information between the first terminal device and the second terminal device includes: sending the downlink QoS information between the first terminal device and the second terminal device to the adjacent terminal device; receiving the downlink QoS information between the first terminal device and the adjacent terminal device from the adjacent terminal device.

[0091] In a seventh aspect, a communication method is provided. This method can be executed by a first device, or by components of the first device, such as a processor, a chip, or a chip system of the first device, etc., and can also be implemented by a logic module or software that can implement all or part of the first device. Hereinafter, an example will be given where this method is executed by the first device. The first device includes a second terminal device or a third terminal device; the communication method includes: determining a third configuration, and sending a first data packet according to the third configuration. The third configuration includes a first local identifier, and the third configuration is used for sending the first data packet. The first data packet includes one or more of the following: first data, or the first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device, and the first terminal device and the second terminal device are relayed through at least one third terminal device.

[0092] In a possible implementation manner, sending the first data packet according to the third configuration includes: sending the first data packet based on a third RLC channel indicated in the third configuration; the third RLC channel is a channel associated with a radio bearer corresponding to the first data.

[0093] In a possible implementation manner, the third configuration is a configuration determined based on uplink QoS information between the first device and the next-hop terminal device in the uplink direction.

[0094] In an eighth aspect, a communication method is provided. This method can be executed by a first device, or by components of the first device, such as a processor, a chip, or a chip system of the first device, etc., and can also be implemented by a logic module or software that can implement all or part of the first device. Hereinafter, an example will be given where this method is executed by the first device. The first device includes a second terminal device or a third terminal device; the communication method includes: determining a fourth configuration, and sending a sixth data packet according to the fourth configuration. The fourth configuration includes a first local identifier, and the fourth configuration is used for sending the sixth data packet. The sixth data packet includes one or more of the following: second data, or the first local identifier; wherein, the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device, and the first terminal device and the second terminal device are relayed through at least one third terminal device.

[0095] In a possible implementation manner, sending the sixth data packet according to the fourth configuration includes: sending the sixth data packet based on a fourth RLC channel indicated in the fourth configuration; the fourth RLC channel is a channel associated with a radio bearer corresponding to the fourth data.

[0096] In a possible implementation manner, the fourth configuration is a configuration determined based on downlink QoS information between the fourth terminal device and the next-hop terminal device in the downlink direction.

[0097] In a possible implementation, the method further includes: receiving downlink QoS information between a fourth terminal device and the next-hop terminal device in the downlink direction.

[0098] In a possible implementation, the method further includes: obtaining downlink QoS information between a fourth terminal device and a second terminal device; determining downlink QoS information between the fourth terminal device and the next-hop terminal device in the downlink direction based on the downlink QoS information between the fourth terminal device and the second terminal device.

[0099] In a ninth aspect, a communication device is provided for implementing the above various methods. The communication device may be the first terminal device in the first aspect, or the fifth aspect, or the sixth aspect above, or a device including the first terminal device above, or a device included in the first terminal device above, such as a chip. Alternatively, the communication device may be the first device in the second aspect, or the seventh aspect, or the eighth aspect above, or a device including the first device above, or a device included in the first device above, such as a chip. Alternatively, the communication device may be the third terminal device in the third aspect, or any implementation manner of the third aspect, or a device including the third terminal device above, or a device included in the third terminal device above, such as a chip. Alternatively, the communication device may be the network device in the fourth aspect, or any implementation manner of the fourth aspect, or a device including the network device above, or a device included in the network device above, such as a chip. The communication device includes corresponding modules, units, or means for implementing the above methods, and the modules, units, or means may be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

[0100] In some possible designs, the communication device may include a processing module and a transceiver module. The transceiver module, which may also be referred to as a transceiver unit, is used to implement the sending and / or receiving functions in any of the above aspects and any possible implementation manners thereof. The transceiver module may be composed of a transceiver circuit, a transceiver, a transceiver, or a communication interface. The processing module may be used to implement the processing functions in any of the above aspects and any possible implementation manners thereof.

[0101] In some possible designs, the transceiver module includes a sending module and a receiving module, which are respectively used to implement the sending and receiving functions in any of the above aspects and any possible implementation manners thereof.

[0102] In a tenth aspect, a communication device is provided, including: at least one processor; the processor is configured to execute computer programs or instructions stored in a memory, so that the communication device executes the method in any of the above aspects. The memory may be coupled to the processor, or may be independent of the processor. The communication device may be the first terminal device in the first aspect, or the fifth aspect, or the sixth aspect, or a device including the first terminal device, or a device included in the first terminal device, such as a chip. Or, the communication device may be the first device in the second aspect, or the seventh aspect, or the eighth aspect, or a device including the first device, or a device included in the first device, such as a chip. Or, the communication device may be the third terminal device in the third aspect, or any implementation manner of the third aspect, or a device including the third terminal device, or a device included in the third terminal device, such as a chip. Or, the communication device may be the network device in the fourth aspect, or any implementation manner of the fourth aspect, or a device including the network device, or a device included in the network device, such as a chip. In some possible designs, the communication device includes a memory, and the memory is configured to store necessary program instructions and data.

[0103] In a possible implementation manner, the processor includes a logic circuit, and an input interface and / or an output interface. Among them, the output interface is configured to perform the sending action in the corresponding method, and the input interface is configured to perform the receiving action in the corresponding method.

[0104] In a possible implementation manner, the communication device further includes a communication interface and a communication bus, and the processor, the memory, and the communication interface are connected through the communication bus. The communication interface is configured to perform the sending and receiving actions in the corresponding method. The communication interface may also be referred to as a transceiver. Optionally, the communication interface includes a transmitter and a receiver. In this case, the transmitter is configured to perform the sending action in the corresponding method, and the receiver is configured to perform the receiving action in the corresponding method.

[0105] In some possible designs, the communication device may be a chip or a chip system. Among them, when the communication device is a chip system, it may be composed of chips, or may include chips and other discrete devices. When the communication device is a chip, the above-mentioned sending action / function may be understood as output, and the above-mentioned receiving action / function may be understood as input.

[0106] In an eleventh aspect, a chip is provided, and the chip includes a processor for implementing the functions involved in any of the above aspects or any of its implementation manners.

[0107] In some possible designs, the chip includes a memory, and the memory is configured to store necessary program instructions and data.

[0108] In a twelfth aspect, a computer-readable storage medium is provided, in which a computer program or instruction is stored. When it runs on a communication device, the communication device can execute the method according to any of the above aspects or any of its implementation manners.

[0109] In a thirteenth aspect, a computer program product including instructions is provided. When it runs on a communication device, the communication device can execute the method according to any of the above aspects or any of its implementation manners.

[0110] In a fourteenth aspect, a communication system is provided. The communication system includes the first terminal device according to the first aspect, the first device according to the second aspect, and the network device according to the fourth aspect; or, the communication system includes the first terminal device according to the first aspect, the third terminal device according to the third aspect, and the network device according to the fourth aspect. Or, the communication system includes the first terminal device according to the fifth aspect or the sixth aspect, the first device according to the second aspect, and the network device according to the fourth aspect; or, the communication system includes the first device according to the seventh aspect or the eighth aspect, the first terminal device according to the first aspect, and the network device according to the fourth aspect.

[0111] For the technical effects brought by any implementation manner of the second aspect to the fourteenth aspect, reference may be made to the technical effects brought by the corresponding implementation manner of the first aspect, which will not be elaborated herein.

[0112] It should be noted that, for various possible implementation manners of any one of the above aspects, they can be combined on the premise that the solutions do not conflict. BRIEF DESCRIPTION OF THE DRAWINGS

[0113] Figure 1 FIG. is a schematic diagram of a scenario for communication between terminal devices based on a sidelink provided by an embodiment of the present application;

[0114] Figure 2 FIG. is a schematic diagram of a user plane protocol stack for communication between terminal devices based on a sidelink provided by an embodiment of the present application;

[0115] Figure 3 FIG. is a schematic diagram of a control plane protocol stack for communication between terminal devices based on a sidelink provided by an embodiment of the present application;

[0116] Figure 4 FIG. is a schematic diagram of a protocol stack of discovery messages during a discovery process provided by an embodiment of the present application;

[0117] Figure 5 FIG. is a schematic diagram of a process flow of a discovery process provided by an embodiment of the present application;

[0118] Figure 6Another flowchart of the discovery process provided by the embodiments of the present application;

[0119] Figure 7 A schematic diagram of a unicast connection establishment process provided by the embodiments of the present application;

[0120] Figure 8 A schematic diagram of the system architecture of an SL U2N relay network architecture provided by the embodiments of the present application;

[0121] Figure 9 A schematic diagram of the protocol stack of a layer 2 SL U2N relay provided by the embodiments of the present application;

[0122] Figure 10 A schematic diagram of the communication architecture of an SL U2U relay provided by the embodiments of the present application;

[0123] Figure 11 A schematic diagram of the user plane protocol stack of a relay method based on layer 3 in the SL U2U relay scenario provided by the embodiments of the present application;

[0124] Figure 12 A schematic diagram of the protocol stack of the user plane and the control plane of a relay method based on layer 2 in the SL U2U relay scenario provided by the embodiments of the present application;

[0125] Figure 13 A schematic diagram of the architecture of an IAB system architecture provided by the embodiments of the present application;

[0126] Figure 14 A schematic diagram of the architecture of a communication system provided by the embodiments of the present application;

[0127] Figure 15 A schematic diagram of the composition of a communication device provided by the embodiments of the present application;

[0128] Figure 16 A flowchart of a communication method provided by the embodiments of the present application;

[0129] Figure 17 Another flowchart of a communication method provided by the embodiments of the present application;

[0130] Figure 18 Another flowchart of a communication method provided by the embodiments of the present application;

[0131] Figure 19 Another flowchart of a communication method provided by the embodiments of the present application;

[0132] Figure 20 Another flowchart of a communication method provided by the embodiments of the present application;

[0133] Figure 21 Schematic diagram of another communication method provided by an embodiment of the present application;

[0134] Figure 22 Schematic diagram of the control plane protocol stack of a sidelink between a first terminal device and a second terminal device provided by an embodiment of the present application;

[0135] Figure 23 Schematic diagram of the user plane protocol stack between a network device and a second terminal device provided by an embodiment of the present application;

[0136] Figure 24 Schematic diagram of the control plane protocol stack between a network device and a second terminal device provided by an embodiment of the present application;

[0137] Figure 25 Schematic diagram of another communication method provided by an embodiment of the present application;

[0138] Figure 26 Schematic diagram of the format of data forwarded between a first terminal device and a network device provided by an embodiment of the present application;

[0139] Figure 27 Schematic diagram of the format of data forwarded between a first terminal device and a second terminal device provided by an embodiment of the present application;

[0140] Figure 28 Schematic diagram of another communication method provided by an embodiment of the present application;

[0141] Figure 29 Schematic diagram of the structure of another communication device provided by an embodiment of the present application. Detailed implementation manners

[0142] To facilitate understanding of the technical solutions provided by the embodiments of the present application, a brief introduction to the related technologies of the present application is first given. The brief introduction is as follows:

[0143] 1. Direct communication between terminal devices

[0144] Direct communication between terminal devices can also be referred to as direct communication between different terminal devices. Among them, direct communication includes wireless fidelity (WiFi) communication, Bluetooth communication, or sidelink communication, etc. Hereinafter, sidelink communication is taken as an example for introduction.

[0145] The sidelink, also known as sidelink, is a transmission link for communication between terminal devices in a wireless communication system. Based on the sidelink, terminal devices can communicate directly with each other without the need to rely on network devices, thereby effectively reducing the latency of communication between terminal devices. As Figure 1 shown, Figure 1 Figure 4 shows a schematic diagram of the communication scenario between terminal device 1 and terminal device 2 based on the sidelink. The communication interface when terminal devices communicate with each other via the sidelink is called the PC5 interface. When terminal devices communicate with each other via the sidelink, they need to communicate through a protocol stack related to the sidelink. Figure 2 Figure 6 shows the user plane protocol stack when terminal device 1 and terminal device 2 communicate based on the sidelink. Figure 3 Figure 8 shows the control plane protocol stack when terminal device 1 and terminal device 2 communicate based on the sidelink.

[0146] When terminal devices communicate with each other via the sidelink, broadcast communication, unicast communication, and multicast communication can be realized. During the broadcast communication based on the sidelink, the terminal device broadcasts and sends unencrypted broadcast service data via the sidelink; terminal devices within the sidelink broadcast reception range can all receive the broadcast service data broadcast by the terminal device. The multicast communication based on the sidelink means that terminal devices within a communication group can communicate with each other via the sidelink; terminal devices within the communication group can send and receive multicast service data with each other via the sidelink. When unicast communication based on the sidelink is carried out between terminal devices, a unicast connection is established between the two terminal devices of the unicast communication on the sidelink. After the unicast connection is established, the two terminal devices can communicate based on the negotiated identifier, and the data transmitted during the communication can be encrypted data or unencrypted data. During the unicast communication process, the sending end and the receiving end need to communicate through the source layer 2 identifier (source layer-2 identifier) and the destination layer 2 identifier (destination layer-2 identifier). The data packet transmitted between the sending end and the receiving end is a sidelink media access control (MAC) layer protocol data unit (PDU). The above source layer 2 identifier and destination layer 2 identifier are carried in the header of the sidelink MAC PDU to facilitate the correct transmission of data from the sending end to the receiving end.

[0147] 2. Radio Bearer (RB)

[0148] A radio bearer is a service provided by Layer 2 for transmitting user data between a terminal device and a network device. A radio bearer includes a series of protocol entities and configurations allocated by the network device for the terminal device, including but not limited to: resources allocated for a Packet Data Convergence Protocol (PDCP) entity, a Radio Link Control (RLC) protocol entity, a MAC protocol entity, and a Physical Layer (PHY). A radio bearer includes a Data Radio Bearer and a Signaling Radio Bearer. The Data Radio Bearer is used to carry data, and the Signaling Radio Bearer is used to carry signaling.

[0149] In the sidelink scenario, signaling and data are transmitted between terminal devices through a sidelink radio bearer (SL RB). The SL RB specifically includes an SL Data Radio Bearer (DRB) and an SL Signaling Radio Bearer (SRB). The SL DRB is used to carry sidelink data, and the SL SRB is used to carry sidelink signaling. In this scenario, the radio bearer configuration includes the configurations of the PDCP layer and the Service Data Adaptation Protocol (SDAP) layer; the protocol entities below the RLC layer are RLC bearers, and the corresponding configurations are given in the RLC bearer configuration.

[0150] 3. Discovery Procedure

[0151] The discovery procedure refers to the process by which a terminal device searches for nearby terminal devices that can perform direct communication through the discovery procedure. After the discovery procedure, the terminal device can establish a unicast connection with the discovered terminal device to achieve data transmission. Taking sidelink communication as an example, the protocol stack of the discovery message used in the discovery procedure is as Figure 4 shown. During the discovery procedure, the protocol layer of the terminal device generates a discovery message and delivers the discovery message to the PDCP layer, and sends it to the peer terminal device through the underlying layers (RLC layer, MAC layer, and PHY layer). The current discovery procedure includes two models: Model A and Model B, which are described separately below.

[0152] 3.1 Discovery Procedure of Model A

[0153] As Figure 5 shown, the discovery process of Model A can be specifically implemented through the following steps 501 and 502.

[0154] Step 501: The announcing UE broadcasts a discovery message. Correspondingly, the monitoring UE receives the discovery message.

[0155] Among them, in Model A, the discovery message can also be called an announcement message; the discovery message carries the relevant information of the announcing UE. For example: the type of services that the announcing UE can provide, and the type of services that can be provided by the announcing UE for the monitoring UE to determine whether it needs to announce.

[0156] As Figure 5 shown, after the announcing UE broadcasts the discovery message, Monitoring UE 1, Monitoring UE 2, Monitoring UE 3, and Monitoring UE 4 respectively receive the discovery message.

[0157] Step 502: The monitoring UE determines whether to establish a sidelink communication with the announcing UE.

[0158] In a possible implementation, after the monitoring UE receives the discovery message, it determines whether to establish a sidelink communication with the announcing UE based on the relevant information of the announcing UE carried in the announcement message.

[0159] As Figure 6 shown, the discovery process of Model B can be specifically implemented through the following steps 601 to 603.

[0160] Step 601: The discoverer UE broadcasts a discovery message. Correspondingly, the discovery UE receives the discovery message.

[0161] Among them, in Model B, the discovery message can be a solicitation message. The discovery message carries the information of the service type required by the discoverer UE.

[0162] As Figure 6 shown, after the discoverer UE broadcasts the discovery message, Discovery UE 1, Discovery UE 2, Discovery UE 3, and Discovery UE 4 respectively receive the discovery message.

[0163] Step 602: The discovered terminal device determines whether it can provide the required service type for the discovering terminal device or whether it is the peer device required by the discovering terminal device.

[0164] In a possible implementation, after receiving the discovery message, the discovered terminal device determines whether it can provide the service type required by the discovering terminal device according to the information of the service type required by the discovering terminal device carried in the discovery message. If the discovered terminal device determines that it can provide the service type required by the discovering terminal device, the discovered terminal device determines to establish a sidelink communication with the discovering terminal device. Further, the discovered terminal device performs the following step 603. If the discovered terminal device determines that it cannot provide the service type required by the discovering terminal device, the discovered terminal device does not need to reply to the discovering terminal device.

[0165] Step 603: The discovered terminal sends a reply message to the discovering terminal device. Correspondingly, the discovering terminal device receives the reply message from the discovered terminal device.

[0166] Among them, the reply message is used to indicate that the discovered terminal can provide the required service type for the discovering terminal device. As Figure 6 shown, if the discovered terminal device 2 and the discovered terminal device 3 determine that they can provide the required service type for the discovering terminal device, the discovered terminal device 2 and the discovered terminal device 3 send a reply message to the discovering terminal.

[0167] It should be noted that in the discovery processes of the above-mentioned Model A and Model B, both the source layer 2 identifier and the destination layer 2 identifier are carried in the discovery message for the terminal device to send or receive the discovery message. The source layer 2 identifier is the identifier assigned by the terminal device itself, and the destination layer 2 identifier is a predefined or preconfigured default identifier.

[0168] 4. Unicast connection establishment process

[0169] After the above discovery process, the terminal device can establish a unicast connection with the discovered terminal device so that the terminal device and the discovered terminal device can perform unicast communication.

[0170] During the unicast connection establishment process, the terminal device initiating the unicast connection establishment process can be called the initiating terminal device, and the peer terminal device can be called the target terminal device.

[0171] As Figure 7 shown, the current unicast connection establishment process includes the following steps 701 to 704.

[0172] Step 701: The initiating terminal device sends a unicast connection establishment request (direct communication request, DCR) message to the target terminal device. Correspondingly, the target terminal device receives the unicast connection establishment request message from the initiating terminal device.

[0173] Step 702: The target terminal device determines whether to establish a unicast connection with the initiating terminal device.

[0174] In the case where the target terminal device determines to establish a unicast connection with the initiating terminal device, the target terminal device performs the following Step 703. Alternatively, in the case where the target terminal device determines not to establish a unicast connection with the initiating terminal device, the target terminal device performs the following Step 704.

[0175] Step 703: The target terminal device sends a unicast connection establishment acceptance (Direct communication accept, DCA) message to the initiating terminal device. Correspondingly, the initiating terminal device receives the DCA message from the target terminal device.

[0176] Step 704: The target terminal device sends a reject message to the initiating terminal device. Correspondingly, the initiating terminal device receives the reject message from the target terminal device.

[0177] 5. SL user equipment (UE) to network (UE-to-Network, U2N) relay

[0178] SL U2N relay, also known as sidelink UE-to-Network relay, refers to a technology where one terminal device communicates with a network device through another terminal device. The network architecture of SL U2N relay is as Figure 8 shown, including a network device, a relay device (U2N), and a remote device; the remote device communicates with the network device through the relay device. Among them, the remote device and the relay device communicate through sidelink, and the communication interface is the PC5 interface; the relay device is directly connected to the network device, and the communication interface is the Uu interface.

[0179] SL U2N relay includes two solutions at layer 2 and layer 3. The protocol stack (including the user plane protocol and the control plane protocol) of layer 2 SL U2N relay is as Figure 9As shown in the figure, the data packets of the remote device are relayed and forwarded below the PDCP layer of the relay device. The relay device only maintains the relay RLC bearer, and the RLC bearer includes the RLC layer, MAC layer, and PHY layer. In other words, there is an end-to-end PDCP layer, SDAP layer, and radio resource control (RRC) layer between the remote device and the network device, but there is no end-to-end RLC layer, MAC layer, and PHY layer. In the SL U2N relay of layer 3, the data packets of the remote device are forwarded at the internet protocol (IP) layer of the network of the relay device.

[0180] 5.1 Data transmission of SL U2N relay

[0181] In the protocol architecture of the SL U2N relay of layer 2, the SRAP layer (or called the adaptation layer) is added. The SRAP layer is used to provide the multiplexing and demultiplexing functions of radio bearers, that is, the function of multiplexing different end-to-end radio bearers onto the same RLC bearer, and the corresponding demultiplexing function. In the multiplexing process, different radio bearers of a remote device can be multiplexed on a PC5 relay RLC channel, or the radio bearers between a relay device and multiple remote devices can be multiplexed on a Uu relay RLC channel.

[0182] Taking the downlink transmission between the network device and the remote device as an example, the SRAP layer of the network device can multiplex one or more radio bearers of the remote device onto a Uu Relay RLC channel, and the data of one or more radio bearers of the remote device can also be mapped onto a PC5 Relay RLC channel.

[0183] Taking the uplink transmission between the network device and the remote device as an example, the SRAP layer of the remote device can map the data of multiple radio bearers of the remote device onto a PC5 Relay RLC channel, and the relay device can map the data of multiple radio bearers of a remote device onto a Uu Relay RLC channel.

[0184] Among them, the PC5 relay RLC channel refers to the RLC bearer between the remote device and the relay device; the Uu relay RLC channel refers to the RLC bearer between the relay device and the network device.

[0185] 6. SL user equipment to user equipment (UE-to-UE, U2U) relay

[0186] The SL U2U relay is a technical solution for relay communication between terminal devices through relay devices, which is used to solve the problem that the direct communication distance between terminal devices through sidelink is short due to insufficient hardware capabilities of terminal devices and other reasons.

[0187] Based on the SL U2U relay technology, terminal devices can perform relay communication through one-hop or multi-hop relay devices, greatly increasing the communication distance between terminal devices. The communication architecture of SL U2U relay is as Figure 10 shown. Data and signaling are transmitted between terminal device 1 and terminal device 2 through a relay device, which is also called a U2U relay device. Terminal device 1 and terminal device 2 can also be called a remote device and a peer remote device respectively. The terminal device that initiates the U2U relay connection is also called the source terminal device (source UE), and the terminal device that receives the relay connection establishment is also called the target terminal device (target UE). It should be noted that in the system architecture as Figure 10 shown, relay communication can be performed between terminal device 1 and terminal device 2 through one or more relay devices, Figure 10 and only one relay device is taken as an example for illustration.

[0188] The implementation methods of U2U relay include: layer-3-based relay method and layer-2-based relay method. In the layer-3-based relay method, user plane data is relayed and forwarded at the IP layer, and the corresponding user plane protocol stack is as Figure 11 shown. When the relay device relays and forwards the data packet sent by terminal device 1 to terminal device 2, the relay device needs to parse to the IP layer and determine the destination terminal device for forwarding according to information such as the IP address. In the layer-2-based relay method, user plane data is relayed and forwarded below the PDCP layer, and its user plane protocol stack and control plane protocol stack are as Figure 12 shown. The relay device only maintains the PC5 relay RLC channel for relay, including the RLC layer, MAC layer, and PHY layer. In addition, an SRAP layer is added between the RLC layer and the PDCP layer in this protocol architecture. The main function of the SRAP layer is the multiplexing and splitting of bearers, that is, it supports that different sidelink radio bearers can be multiplexed onto one PC5 RLC bearer or the sidelink radio bearer data multiplexed on one PC5 RLC bearer can be split.

[0189] 7. Integrated Access and Backhaul (IAB)

[0190] The IAB is used to support the wireless fronthaul and relay links for wireless communication, enabling the flexible and dense deployment of new radio (NR) cells. The IAB system architecture is as shown in Figure 13 shown. As shown in Figure 13 shown, the nodes in the IAB system include: IAB-node and IAB-donor. Among them, the IAB-node is used to support the access and fronthaul functions of NR. The IAB-node includes two parts: the IAB-node-mobile termination (MT) (also known as the IAB-MT) and the IAB-node-distributed unit (DU) (also known as the IAB-DU). The IAB-node-MT is connected to the DU of its parent node or the IAB-donor-DU as an ordinary terminal device, serving as a wireless transmission fronthaul link. The IAB-node-DU is a pole station cell on the access side under the IAB-node, used to provide blind spot coverage and provide access for ordinary terminal devices or lower-level IAB-node-MTs.

[0191] The IAB-donor is a gNodeB (also known as the gNodeB-donor) that supports the additional functions of the IAB, and is connected to the core network through a non-IAB connection, such as optical fiber. The IAB-donor includes the IAB-donor-central unit (CU) and the IAB-donor-DU. The IAB-donor-CU provides a connection for the IAB-donor-DU and the IAB-node-DU; the IAB-donor-DU provides access for the UE or the IAB-MT.

[0192] The IAB node or the IAB donor DU is also configured with a mapping relationship configuration for data forwarding. The configuration includes the mapping relationship between (the previous-hop BAP address, Backhaul RLC channel ID) and (the next-hop BAP address, Backhaul RLC channel ID). The IAB node forwards data according to this mapping relationship, including: after receiving a data packet, the IAB node first queries the routing table to determine whether the data is its own data. If so, it delivers the data to the upper layer of its own node. If not, it delivers the data to the backhaul RLC channel corresponding to the next-hop IAB node according to the mapping relationship in the mapping relationship configuration.

[0193] Above, a brief introduction to the related technologies of this application is given.

[0194] In the current relay scenario, when the distance between the remote device and the network device is far and the remote device cannot access the network device through a one-hop relay device, the remote device can access the network device through a multi-hop relay device and communicate with the network device through the multi-hop relay device.

[0195] In the scenario where the remote device is connected to the network device through a multi-hop relay device, if the network architecture is networked using an architecture similar to the existing IAB networking architecture mentioned above, the remote device will be connected to a relay device, and the relay device and the network device are also connected through a relay. Each relay device is configured with the forwarding configuration of the previous hop and the next hop, and the relay device forwards the data transmitted between the network device and the remote device hop by hop through the forwarding configuration. However, in this scenario, since the remote device only establishes a direct connection with the U2N relay device of its adjacent hop, the remote device can only perceive the U2N relay device of its adjacent hop, but cannot perceive the relay devices of other hops. For example, when a link abnormality occurs at the Uu port of a relay device directly connected to the network device, it will not be able to directly inform the remote device, which may cause communication interruption of the remote device.

[0196] To solve the above technical problems, the present application provides a communication method. When the second terminal device is connected to the first terminal device through a multi-hop relay device, the first terminal device directly connected to the network device can establish a unicast connection with the second terminal device, so that the second terminal device can directly perceive the first terminal device directly connected to the network device.

[0197] The following is a detailed description of the solution provided by the embodiment of the present application. Before introducing the embodiment of the present application, the following points are explained.

[0198] In the description of this application, unless otherwise specified, " / " indicates that the objects associated with each other are in an "or" relationship, for example, A / B can represent A or B; "and / or" in this application is merely a description of the association relationship between associated objects, indicating that three relationships may exist, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural.

[0199] In the description of this application, A sending a message to B can be understood as A sending a message to B through one or more network elements.

[0200] In the description of the present application, unless otherwise specified, "a plurality" means two or more than two. "At least one of the following" or its similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, and / or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple.

[0201] In addition, for the convenience of clearly describing the technical solutions of the embodiments of the present application, in the embodiments of the present application, terms such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and roles. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity and execution order, and "first", "second", etc. do not necessarily mean different.

[0202] In the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, using words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner for easy understanding.

[0203] It can be understood that throughout the specification, the "embodiments" mentioned mean that specific features, structures, or characteristics related to the embodiments are included in at least one embodiment of the present application. Therefore, the various embodiments throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics can be combined in one or more embodiments in any suitable manner. It can be understood that in various embodiments of the present application, the magnitude of the serial numbers of the various processes does not mean the sequence of execution, and the execution sequence of the various processes should be determined by their functions and internal logics, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0204] It can be understood that in the present application, "when..." and "if" both refer to corresponding processing under certain objective circumstances, do not limit time, do not require a judgment action when implemented, and do not mean the existence of other limitations.

[0205] It can be understood that some optional features in the embodiments of the present application can, in some scenarios, be implemented independently without relying on other features, such as the current solution they are based on, to solve the corresponding technical problems and achieve the corresponding effects. In some scenarios, they can also be combined with other features according to requirements. Correspondingly, the devices given in the embodiments of the present application can also implement these features or functions accordingly, which will not be elaborated here.

[0206] In this application, unless otherwise specified, the same or similar parts among various embodiments can be referred to each other. In various embodiments of this application, as well as in each implementation manner / implementation method / realization method in each embodiment, if there is no special specification and logical conflict, the terms and / or descriptions among different embodiments, as well as among each implementation manner / implementation method / realization method in each embodiment, are consistent and can be referenced to each other. The technical features in different embodiments, as well as in each implementation manner / implementation method / realization method in each embodiment, can be combined to form new embodiments, implementation manners, implementation methods, or realization methods according to their internal logical relationships. The implementation manners of this application described below do not constitute a limitation on the protection scope of this application.

[0207] The technical solutions provided by the embodiments of this application can be applied to various communication systems. The communication system can be a 3rd generation partnership project (3GPP) communication system. For example, a 4th generation (4G) long term evolution (LTE) system, a 5th generation mobile communication technology (5G) NR system, a 6th generation (6G) communication system, a vehicle to everything (V2X) system, a system with hybrid networking of LTE and NR, or a device-to-device (D2D) system, a machine to machine (M2M) communication system, the Internet of things (IoT), and other next-generation communication systems, etc. Alternatively, the communication system can also be a non-3GPP communication system, and the embodiments of this application do not limit this.

[0208] The communication method provided by the embodiments of this application can be applied to a scenario where a second terminal device needs to access a network device through a multi-hop relay device. In this scenario, the second terminal device discovers a relay device that supports providing access to the network device through multi-hop through a discovery process, and establishes a unicast connection with the relay device, and then accesses the network device.

[0209] For example, as Figure 14 shown, it is a schematic diagram of the architecture of a communication system provided by the embodiments of this application. The communication system includes: a first terminal device 1401, a second terminal device 1402, at least one third terminal device 1403, and a network device 1404.

[0210] Among them, the second terminal device 1402 is a remote device that needs to access the network device through a multi-hop relay device. The first terminal device 1401 is a relay device directly connected to the network device 1404, and can also be referred to as a U2N relay device. At least one third terminal device 1403 is a relay device between the second terminal device 1402 and the first terminal device 1401, and is used to provide a relay service between the first terminal device 1401 and the second terminal device 1402.

[0211] In some scenarios, at least one third terminal device 1403 can be a U2U relay device, that is, a relay device that provides a relay service between terminal devices.

[0212] In still other scenarios, at least one third terminal device 1403 can establish a unicast connection with the first terminal device 1401, and then access the network device 1404 according to the first terminal device 1401. At this time, at least one third terminal device 1403 can be understood as a U2N relay device connected to the network device 1403.

[0213] In Figure 14 , the second terminal device 1402 accesses the network device 1404 through at least one third terminal device 1403 and the first terminal device 1401 in sequence.

[0214] It should be noted that in the embodiments of the present application, the number of third terminal devices is mainly taken as 1 for illustration. Of course, the number of third terminal devices can be greater than 1. At this time, the operations performed by other third terminal devices can refer to the third terminal device described in the following embodiments of the present application, which are explained uniformly here and will not be elaborated below.

[0215] Optionally, the terminal device involved in the present application (including the first terminal device, the second terminal device, or the third terminal device, etc.) can be a user equipment (UE), access terminal, terminal unit, user station, terminal station, mobile station, mobile unit, remote station, remote terminal, user terminal, terminal equipment (TE), mobile device, wireless communication device, terminal agent, tablet computer (pad), handheld device with wireless communication function, computing device, or other processing device connected to a wireless modem, vehicle-mounted device, vehicle-mounted transceiver unit, wearable device, or terminal device. The access terminal can be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication function, computing device, or other processing device connected to a wireless modem, vehicle-mounted device, drone, robot, intelligent point of sale (POS) machine, customer-premises equipment (CPE), or wearable device, virtual reality (VR) terminal device, augmented reality (AR) terminal device, wireless terminal in industrial control, wireless terminal in self-driving, wireless terminal in remote medical, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, etc. Alternatively, the terminal device can be a terminal with communication function in the internet of things (IoT), such as a terminal in V2X (e.g., vehicle-to-everything device), a terminal in device-to-device (D2D) communication, or a terminal in machine-to-machine (M2M) communication, etc. The terminal device can be mobile or fixed.

[0216] Embodiments of this application do not limit the form of the terminal device. The device for implementing the functions of the terminal device can be the terminal device; or it can be a device capable of supporting the terminal device to implement this function, such as a chip system. This device can be installed in the terminal device or used in combination with the terminal device. In the embodiments of this application, the chip system can be composed of chips or can also include chips and other discrete devices.

[0217] Optionally, the network device involved in this application (which can also be called an access network device or an access node, etc.) can be a device for communicating with the terminal device. For example, this network device can be a network device in a 3GPP-related cellular system, such as a network device in a 4G or 5G mobile communication system, or an evolved system for the future (such as a 6G mobile communication system). Or, this network device can also be a network device in an open radio access network (O-RAN), a cloud radio access network (CRAN), or a WiFi system. Or, this network device can also be a network device in a communication system that integrates two or more of the above systems. Embodiments of this application do not make specific limitations on this.

[0218] In a possible scenario, the network device can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next generation NodeB (gNB), a next generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc. This network device can be a macro base station, a micro base station or an indoor station, a relay node or a donor node, or a radio controller in a CRAN scenario. Optionally, this network device can also be a server, a wearable device, a vehicle or an in-vehicle device, etc. For example, the network device in V2X technology can be a road side unit (RSU).

[0219] In another possible scenario, multiple network devices cooperate to assist a terminal in achieving wireless access, and different network nodes respectively implement some functions of a base station. For example, the network device can also be a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and the DU can be set separately, or can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as being included in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0220] In different systems, the CU (or CU-CP and CU-UP), DU, or RU may also have different names, but those skilled in the art can understand their meanings. For example, the network device can be a network device or a module of a network device in an open radio access network (ORAN) system. In the ORAN system, the CU can also be called an open (O)-CU, the DU can also be called an O-DU, the CU-CP can also be called an O-CU-CP, the CU-UP can also be called an O-CU-UP, and the RU can also be called an O-RU. Any one of the CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0221] In the embodiments of this application, the form of the network device is not limited. The device for implementing the functions of the network device can be the network device; it can also be a device capable of supporting the network device to implement such functions, such as a chip system. This device can be installed in the network device or used in matching with the network device.

[0222] In one possible implementation manner, the network device and the terminal device in the embodiments of this application can also be called communication devices, which can be a general device or a special device, and the embodiments of this application do not make specific limitations thereon.

[0223] In a possible implementation, the relevant functions of the terminal device or network device in the embodiments of the present application can be implemented by one device, or by multiple devices jointly, or by one or more functional modules within one device. The embodiments of the present application do not make specific limitations thereto. It can be understood that the above functions can be either network elements in a hardware device, or software functions running on dedicated hardware, or a combination of hardware and software, or virtualized functions instantiated on a platform (such as a cloud platform).

[0224] In a possible implementation, Figure 15 is a schematic diagram of the composition of a communication device 1500 provided by an embodiment of the present application, Figure 14 Both the network device and the terminal device shown can adopt Figure 15 the composition structure shown, or include Figure 15 the components shown; or, Figure 14 The components (such as chips) in the network device and the terminal device shown can all adopt Figure 15 the composition structure shown, or include Figure 15 the components shown. It can be understood that the communication device 1500 includes means in the necessary forms such as modules, units, elements, circuits, or interfaces, which are appropriately configured together to execute the present solution.

[0225] As Figure 15 shown, the communication device 1500 includes one or more processors 111. The processor 111 can be a general-purpose processor or a dedicated 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 a communication device (such as a RAN node, a terminal, or a chip, etc.), execute software programs, and process data of software programs.

[0226] Optionally, in one design, the processor 111 can include a program 113 (sometimes also referred to as code or instructions), and the program 113 can be run on the processor 111, so that the communication device 1500 executes the methods described in the following embodiments.

[0227] Optionally, the communication device 1500 can include one or more memories 112, on which there is a program 114 (sometimes also referred to as code or instructions), and the program 114 can be run on the processor 111, so that the communication device 1500 executes the methods described in the following method embodiments.

[0228] Optionally, the processor 111 and / or the memory 112 may include artificial intelligence (AI) modules 115 and 118, and the AI modules are used to implement AI-related functions. The AI modules may be implemented in a software, hardware, or a combination of software and hardware manner. For example, the AI module may include a Radio Access Network (RAN) Intelligence Controller (RIC) module. For example, the AI module may be a near real-time RIC or a non-real-time RIC.

[0229] Optionally, data may also be stored in the processor 111 and / or the memory 112. The processor and the memory may be provided separately or integrated together.

[0230] Optionally, the communication device 1500 may further include a transceiver 115 and / or an antenna 116. The processor 111 is sometimes also referred to as a processing unit, which controls the communication device (such as a RAN node or a terminal). The transceiver 115 is sometimes also referred to as a transceiver unit, a transceiver, a transceiver circuit, or a transceiver, etc., and is used to implement the transceiver function of the communication device through the antenna 116.

[0231] It should be noted that Figure 15 the component structure shown in Figure 15 does not constitute a limitation on the communication device. Except for

[0232] the components shown, the communication device may include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0233] In addition, actions, terms, etc. involved in the embodiments of the present application may refer to each other without limitation. In the embodiments of the present application, the message names or parameter names in the messages exchanged between various devices are only examples, and other names may also be used in specific implementations without limitation.

[0234] Next, in combination with Figures 1 to 15 , the communication method provided by the embodiments of the present application will be described.

[0235] It should be noted that in the following embodiments of the present application, the message names between various network elements, the names of various parameters, or the names of various information are only examples, and in other embodiments, they may also be other names. The communication method provided by the present application does not make specific limitations thereto.

[0236] It can be understood that in the embodiments of the present application, each network element may execute some or all of the steps in the embodiments of the present application. These steps or operations are merely examples, and the embodiments of the present application may also execute other operations or various modifications of the operations. In addition, each step may be executed in a different order presented in the embodiments of the present application, and it is possible not to execute all the operations in the embodiments of the present application.

[0237] Figure 16 It is a schematic flowchart of a communication method provided by an embodiment of the present application. In the embodiments of the present application, the second terminal device discovers the first terminal device through at least one third terminal device. After the second terminal device discovers the first terminal device, it establishes a connection with the first terminal device and accesses the network device through the first terminal device. After accessing the network device, the second terminal device can communicate with the network device through the first terminal device and at least one third terminal device to transmit data. Hereinafter, in combination with the above discovery process and connection establishment process, taking the establishment of a unicast connection as an example, the functions and actions performed by each device in the communication system provided by the embodiments of the present application will be introduced. As Figure 16 shown, the communication method includes the following steps:

[0238] Step 1601: The first terminal device sends Message 1. Correspondingly, the third terminal device receives Message 1 from the first terminal device.

[0239] Among them, Message 1 is used to indicate that the first terminal device supports providing a relay service between the second terminal device and the network device, and supports relaying between the first terminal device and the second terminal device through at least one third terminal device (it can be understood that Message 1 is used to indicate the relay capability of the first terminal device). Or, Message 1 is used to indicate that the first terminal device supports providing a multi-hop relay service between the terminal device and the network device. It should be noted that in the embodiments of the present application, providing a relay service between the second terminal device and the network device can be understood as providing a relay service between the remote device that needs to be relayed by a relay device and the network device, rather than providing a relay service between a specific terminal device and the network device. For example, supporting providing a relay service between the second terminal device and the network device can be understood as supporting providing a relay service between the remote device that needs to be relayed by a relay device and the network device. Requesting to provide a relay service between the second terminal device and the network device can be understood as requesting to provide a relay service between the remote device that needs to be relayed by a relay device and the network device. The present application does not make any limitations in this regard.

[0240] In a possible implementation, Message 1 is used to indicate that the first terminal device supports providing a relay service between the second terminal device and the network device, and supports relaying between the first terminal device and the second terminal device through at least one third terminal device. It can be understood that the indication information is carried in Message 1, and this indication information is used to indicate that the first terminal device supports providing a relay service between the second terminal device and the network device, and that relaying between the first terminal device and the second terminal device is through at least one third terminal device. Or this indication information is used to indicate that the first terminal device supports providing a multi-hop relay service between the terminal device and the network device.

[0241] Optionally, Message 1 includes first indication information and / or second indication information, and the first indication information and / or the second indication information are used to indicate that the first terminal device supports providing a relay service between the second terminal device and the network device, and supports relaying between the first terminal device and the second terminal device through at least one third terminal device. For example, Message 1 includes first indication information, and the first indication information is used to indicate that the first terminal device supports providing a relay service between the second terminal device and the network device, and supports relaying between the first terminal device and the second terminal device through at least one third terminal device. Or the first indication information is used to indicate that the first terminal device supports providing a multi-hop relay service between the terminal device and the network device. Another example is that Message 1 includes second indication information, and the second indication information is used to indicate that the first terminal device supports providing a relay service between the second terminal device and the network device, and supports relaying between the first terminal device and the second terminal device through at least one third terminal device. Or the first indication information is used to indicate that the first terminal device supports providing a multi-hop relay service between the terminal device and the network device. Still another example is that Message 1 includes first indication information and second indication information. The first indication information is used to indicate that the first terminal device supports providing a relay service between the second terminal device and the network device, and the second indication information is used to indicate supporting relaying between the first terminal device and the second terminal device through at least one third terminal device. Message 1 jointly indicates through the first indication information and the second indication information that the first terminal device supports providing a relay service between the second terminal device and the network device, and supports relaying between the first terminal device and the second terminal device through at least one third terminal device. Or Message 1 jointly indicates through the first indication information and the second indication information that the first terminal device supports providing a multi-hop relay service between the terminal device and the network device. As an example, the first indication information may be a relay service code (RSC), and the second indication information may be a relay indication.

[0242] In a possible implementation, Message 1 includes one or more of the following: the identifier of the second terminal device, or the identifier of the first terminal device.

[0243] For example, Message 1 includes the identifier of the first terminal device. The first terminal device can indicate its relay capability based on the identifier of the first terminal device and the above-mentioned indication information. At this time, Message 1 is used, for example, to indicate the relay capability of the first terminal device; or, Message 1 is used, for example, to indicate that the first terminal device supports providing a multi-hop relay service between the second terminal device and the network device. Or, Message 1 is also used, for example, to indicate a response to establishing a unicast connection with the second terminal device.

[0244] Or for example, Message 1 includes one or more of the following: the identifier of the second terminal device, the identifier of the first terminal device, the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device. Here, at least one third terminal device refers to all or part of the third terminal devices between the first terminal device and the second terminal device. In a possible way, Message 1 is a discovery message replied based on a request from the second terminal device, and is used to indicate providing a multi-hop relay service for the second terminal device. In another possible way, the first terminal device requests to establish a unicast connection with the second terminal device through the identifier of the second terminal device and the identifier of the first terminal device in Message 1, so that the second terminal device can determine that the established unicast connection is the unicast connection between the first terminal device and the second terminal device according to the identifier of the second terminal device and the identifier of the first terminal device. At this time, Message 1 is used, for example, to indicate the relay capability of the first terminal device and to request to establish a unicast connection with the second terminal device.

[0245] Optionally, Message 1 in the embodiments of the present application may also be referred to as the first message or the fourth message. For unified description here, it will not be elaborated further below.

[0246] Step 1602: The third terminal device sends Message 2. Correspondingly, the second terminal device receives Message 2.

[0247] Among them, Message 2 is used to indicate that the third terminal device supports providing a relay service between the second terminal device and the network device, and the first terminal device and the second terminal device are relayed through at least one third terminal device. Or, Message 2 is used to indicate that the third terminal device supports providing a multi-hop relay service between the second terminal device and the network device. Or, Message 2 is used to indicate that the first terminal device and the third terminal device support providing a multi-hop relay service between the second terminal device and the network device.

[0248] In a possible implementation, the third terminal device receives Message 1, generates Message 2 based on Message 1, and after that, the third terminal device sends Message 2. Correspondingly, the second terminal device receives Message 2.

[0249] Optionally, with reference to the above Message 1, Message 2 may also include the above first indication information and / or second indication information. The first indication information and / or second indication information is used to indicate that the third terminal device supports providing a relay service between the second terminal device and the network device, and the first terminal device supports relaying with the second terminal device through at least one third terminal device. Or, the first indication information and / or second indication information is used to indicate that the third terminal device supports providing a multi-hop relay service between the second terminal device and the network device. Or, the first indication information and / or second indication information is used to indicate that the first terminal device and the third terminal device support providing a multi-hop relay service between the second terminal device and the network device. For the specific description of the first indication information and the second indication information, reference may be made to the above step 1601, which will not be elaborated here.

[0250] In a possible implementation, Message 2 includes one or more of the following: the identifier of the first terminal device, the identifier of the terminal device between the first terminal device and the current third terminal device, or the hop count information between the first terminal device and the current third terminal device. The current third terminal device refers to the third terminal device that sends this Message 2. For example, after the first terminal device broadcasts Message 1, Message 2 corresponding to Message 1 is sent through multiple third terminal devices in sequence. The third terminal device corresponds to Message 2 one by one. At this time, the current third terminal device may be the third terminal device corresponding to the Message 2 received by the second terminal device, or the third terminal device corresponding to other Message 2.

[0251] For example, Message 2 includes one or more of the following: the identifier of the first terminal device, the identifier of the terminal device between the first terminal device and the current third terminal device, or the hop count information between the first terminal device and the current third terminal device. At this time, Message 2 is used to indicate, for example, the relay capability of the third terminal device (correspondingly, at this time, Message 1 is also only used to indicate the relay capability of the first terminal device); or, Message 2 is used to indicate that the third terminal device supports providing a multi-hop relay service between the second terminal device and the network device (correspondingly, at this time, Message 1 is also used to indicate that the first terminal device supports providing a multi-hop relay service between the terminal device and the network device); or, Message 1 is also used to indicate a response to establishing a unicast connection with the second terminal device (correspondingly, at this time, Message 1 is also used to indicate a response to establishing a unicast connection with the second terminal device).

[0252] Based on this, the second terminal device may determine the relay service capability of the first terminal device based on the identifier of the first terminal device in Message 2 and the first indication information and / or the second indication information, and determine whether to select the first terminal device to establish a unicast connection according to the identifier of the terminal device between the first terminal device and the current third terminal device, or the hop count information between the first terminal device and the current third terminal device.

[0253] Or for example, Message 2 includes one or more of the following: the identifier of the second terminal device, the identifier of the first terminal device, the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device. At this time, Message 2 is used to indicate the relay capability of the third terminal device. In a possible scenario, Message 2 is a discovery response message for indicating providing a multi-hop relay service for the second terminal device. In a possible manner, Message 2 is used to indicate the relay capability of the third terminal device and to request to establish a unicast connection with the second terminal device (correspondingly, at this time, Message 1 is also used to indicate the relay capability of the first terminal device and to request to establish a unicast connection with the second terminal device); or, Message 2 is used to indicate, for example: the third terminal device supports providing a multi-hop relay service between the second terminal device and the network device and to request to establish a unicast connection with the second terminal device (correspondingly, at this time, Message 1 is also used to indicate that the first terminal device supports providing a multi-hop relay service between the terminal device and the network device and to request to establish a unicast connection with the second terminal device); or, Message 2 is further used to indicate in response to the second terminal device establishing a unicast connection and to request to establish a unicast connection with the second terminal device (correspondingly, at this time, Message 1 is also used to indicate in response to establishing a unicast connection with the second terminal device and to request to establish a unicast connection with the second terminal device).

[0254] Optionally, Message 2 in the embodiments of the present application may also be referred to as the fourth message, which is hereby uniformly described and will not be elaborated hereinafter.

[0255] Step 1603: The second terminal device sends Message 3 to the third terminal device. Correspondingly, the third terminal device receives Message 3 from the second terminal device.

[0256] Among them, Message 3 is used to indicate establishing a unicast connection between the second terminal device and the first terminal device. Among them, the unicast connection is established through at least one third terminal device.

[0257] Optionally, referring to the above Message 1, Message 3 may also include the above first indication information and / or second indication information, and indicate through the first indication information and / or second indication information that: the first terminal device supports providing a relay service between the second terminal device and the network device, and the relay between the first terminal device and the second terminal device is performed through at least one third terminal device. For the specific description of the first indication information and the second indication information, reference may be made to the above step 1601, which will not be elaborated here.

[0258] In a possible implementation, Message 3 includes one or more of the following: the identifier of at least one of the third terminal devices, or the hop count information between the first terminal device and the second terminal device.

[0259] For example, Message 3 includes one or more of the following: the identifier of the second terminal device, the identifier of the first terminal device, the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device. At this time, Message 3 is used, for example, to request the establishment of a unicast connection between the second terminal device and the first terminal device (correspondingly, at this time, Message 1 is used, for example, to indicate the relay capability of the first terminal device, and Message 2 is used, for example, to indicate the relay capability of the first terminal device).

[0260] Or for example, Message 3 includes one or more of the following: the identifier of the second terminal device, or the identifier of the first terminal device. At this time, Message 3 is used, for example, to respond to the establishment of a unicast connection between the second terminal device and the first terminal device (correspondingly, at this time, Message 1 is used, for example, to indicate the relay capability of the first terminal device, and for example, to request the establishment of a unicast connection with the second terminal device; Message 2 is used, for example, to indicate the relay capability of the second terminal device, and for example, to request the establishment of a unicast connection with the second terminal device).

[0261] Optionally, Message 3 in the embodiments of the present application may also be referred to as the fifth message, which is uniformly described here and will not be elaborated below.

[0262] Step 1604: The third terminal device sends Message 4. Correspondingly, the first terminal device receives Message 4.

[0263] Wherein, Message 4 is used to indicate the establishment of a unicast connection between the second terminal device and the first terminal device.

[0264] In a possible manner, Message 3 and Message 4 may include the same content. That is to say, after receiving Message 3, the third terminal device directly forwards Message 3 through the adaptation layer.

[0265] Optionally, referring to the above Message 1, Message 4 may also include the above first indication information and / or second indication information. The first indication information and / or second indication information is used to indicate that: the third terminal device supports providing a relay service between the second terminal device and the network device, and supports relaying between the first terminal device and the second terminal device through at least one third terminal device. Alternatively, the first indication information and / or second indication information is used to indicate that: the third terminal device supports providing a multi-hop relay service between the second terminal device and the network device. Or, the first indication information and / or second indication information is used to indicate that: the first terminal device and the third terminal device support providing a multi-hop relay service between the second terminal device and the network device. For the specific description of the first indication information and the second indication information, reference may be made to the above step 1601, which will not be elaborated here.

[0266] In a possible implementation, Message 4 includes one or more of the following: the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device.

[0267] For example, Message 4 includes one or more of the following: the identifier of the second terminal device, the identifier of the first terminal device, the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device. At this time, Message 4 is used to indicate, for example, the establishment of a unicast connection between the second terminal device and the first terminal device (at this time, Message 1 is used to indicate the relay capability of the first terminal device, Message 2 is used to indicate the relay capability of the first terminal device, and Message 3 is used to request the establishment of a unicast connection between the second terminal device and the first terminal device).

[0268] Or for example, Message 4 includes one or more of the following: the identifier of the second terminal device, or the identifier of the first terminal device. At this time, Message 4 is used to respond to the establishment of a unicast connection between the second terminal device and the first terminal device (correspondingly, at this time, Message 1 is used to indicate the relay capability of the first terminal device and, for example, to request the establishment of a unicast connection with the second terminal device; Message 2 is used to indicate the relay capability of the second terminal device and, for example, to request the establishment of a unicast connection with the second terminal device; Message 3 is used to respond to the establishment of a unicast connection between the second terminal device and the first terminal device).

[0269] It should be noted that the embodiments of the present application do not limit the order of the first terminal device sending Message 1 and receiving Message 4. For example, the first terminal device may first send Message 1 and receive Message 4 after sending Message 1; or, the first terminal device may first receive Message 4 and send Message 1 after receiving Message 4; or, the first terminal device may receive Message 4 while sending Message 1. The embodiments of the present application do not limit this.

[0270] For example, in the case where a first terminal device initiates a unicast connection establishment process with a second terminal device, the first terminal device sends Message 1 to request the establishment of a unicast connection with the second terminal device. A third terminal device sends Message 2 to the second terminal device to request the establishment of a unicast connection with the second terminal device. When the second terminal device determines to establish a unicast connection with the first terminal device, the second terminal device sends Message 3 to respond to the establishment of the unicast connection with the first terminal device. The third terminal device sends Message 4 to the first terminal device to respond to the establishment of the unicast connection with the first terminal device.

[0271] For another example, in the case where a second terminal device initiates a unicast connection establishment process with a first terminal device, the second terminal device sends Message 3 to request the establishment of a unicast connection with the first terminal device. A third terminal device sends Message 4 to the first terminal device to request the establishment of a unicast connection with the first terminal device. When the first terminal device determines to establish a unicast connection with the second terminal device, the first terminal device sends Message 1 to respond to the establishment of the unicast connection with the second terminal device. The third terminal device sends Message 2 to the second terminal device to respond to the establishment of the unicast connection with the second terminal device.

[0272] Optionally, Message 4 in the embodiments of the present application may also be referred to as the fifth message or the second message. This is uniformly described herein and will not be elaborated further below.

[0273] The present application provides a communication method. When a second terminal device is connected to a first terminal device through multi-hop relay, a unicast connection is established between the first terminal device directly connected to a network device and the second terminal device, so that the second terminal device can directly sense the first terminal device directly connected to the network device.

[0274] In a possible implementation, when Message 1 is used to indicate the relay capability of the first terminal device, the first terminal device may actively send Message 1 so that other terminal devices can determine the relay capability of the first terminal device according to Message 1; or, the first terminal device may also send the relay capability of the first terminal device based on the request of other terminal devices.

[0275] Among them, when the first terminal device sends the relay capability of the first terminal device based on the request of other terminal devices, combined with Figure 16 , as Figure 17 shown, the communication method provided by the embodiments of the present application further includes:

[0276] Step 1701: The second terminal device sends Message 5. Correspondingly, the third terminal device receives Message 5.

[0277] Among them, Message 5 is used to request the provision of a relay service (that is, Message 5 is used to request to provide a relay service between the second terminal device and the network device).

[0278] In one possible implementation, message 5 is used to request the provision of a relay service. It can be understood that the message 5 carries indication information, and the indication information is used to request the provision of a relay service.

[0279] Optionally, message 5 includes: third indication information and / or fourth indication information; the third indication information and / or the fourth indication information are used to request the provision of a relay service, and the relay between the first terminal device and the second terminal device is performed through at least one third terminal device. For example, the message 5 includes third indication information, and the third indication information is used to request a relay service (that is, to provide a relay service between the second terminal device and the network device), and the relay between the first terminal device and the second terminal device is performed through at least one third terminal device. Another example is that the message 5 includes fourth indication information, and the fourth indication information is used to provide a relay service, and the relay between the first terminal device and the second terminal device is performed through at least one third terminal device. Another example is that the message 5 includes third indication information and fourth indication information, the third indication information is used to request the provision of a relay service, and the fourth indication information is used to indicate that the relay between the first terminal device and the second terminal device is performed through at least one third terminal device; the message 5 jointly indicates that the second terminal device requests the provision of a relay service through the third indication information and the fourth indication information, and the relay between the first terminal device and the second terminal device is performed through at least one third terminal device.

[0280] As an example, the third indication information may be a relay service code, and the fourth indication information may be a relay indication. It should be noted that the relay service code corresponding to the third indication information may be the same as or different from the relay service code corresponding to the first indication information, and the relay indication corresponding to the fourth indication information may be the same as or different from the relay indication corresponding to the second indication information. The present application does not make any limitations in this regard.

[0281] In one possible implementation, message 5 includes one or more of the following: the identifier of the first terminal device, or the identifier of the second terminal device. Message 5 can indicate the terminal device that initiates the discovery process through the identifier of the second terminal device; or indicate the terminal device to be discovered through the identifier of the first terminal device. It should be noted that when the second terminal device has pre-determined the first terminal device to be discovered, the message 5 may include the identifier of the first terminal device; when the second terminal device has not pre-determined the first terminal device to be discovered, the message 5 may not include the identifier of the first terminal device.

[0282] Optionally, the message 5 in the embodiments of the present application may also be referred to as the sixth message, which is uniformly described here and will not be elaborated below.

[0283] Step 1702: The third terminal device sends Message 6. Correspondingly, the first terminal device receives Message 6.

[0284] Among them, Message 6 is used to request the provision of a relay service (that is, Message 6 is used to request to provide a relay service between the second terminal device and the network device). Optionally, Message 6 is further used to indicate that the third terminal device supports multi-hop relay services.

[0285] It can be understood that Message 6 may also carry indication information that is the same as or similar to the indication information of Message 5. Specifically, it can be understood with reference to the indication information in the above Message 5, and this application will not elaborate on this.

[0286] In a possible implementation manner, Message 6 includes one or more of the following: the identifier of at least one third terminal device, or the hop count information between the first terminal device and the second terminal device. Message 6 is a message sent by the third terminal device to the first terminal device for discovering the first terminal device. In this message, each third terminal device that forwards this message will add its own identifier to this message or update the hop count information. Therefore, the Message 6 finally received by the first terminal device will include the identifier of each third terminal device, or the hop count information between the first terminal device and the second terminal device. It can be understood that in the case where there are multiple third terminal devices between the first terminal device and the second terminal device, the Message 6 sent by other terminal devices except the third terminal device connected to the first terminal device includes one or more of the following: the identifier of the third terminal device between this other third terminal device and the second terminal device, the identifier of this other third terminal device, and the hop count information between this other third terminal device and the second terminal device.

[0287] In addition, Message 6 may further include one or more of the following: the identifier of the first terminal device, or the identifier of the second terminal device.

[0288] Optionally, Message 6 in the embodiments of this application may also be referred to as the sixth message or the third message. This is uniformly explained here and will not be elaborated on below.

[0289] It should be noted that the above Step 1701 - Step 1702 are optional steps. For example, when the first terminal device sends the relay capability of the first terminal device based on the request of other terminal devices, the above Step 1701 - Step 1702 are executed. When the first terminal device actively sends the relay capability of the first terminal device, the above Step 1701 - Step 1702 do not need to be executed.

[0290] The above steps 1601 - 1604 and steps 1701 - 1702 mainly relate to the discovery process and the unicast establishment process. Referring to the discovery process of SL U2U relay in the above - mentioned related technology, in the embodiments of the present application, the discovery process and the unicast establishment process can also include the following three methods: method a, method b, and method c. The following is a detailed description.

[0291] Method a: As Figure 18 shown, the discovery process of method a can be specifically implemented through the following steps:

[0292] Step 1801: The first terminal device sends relay capabilities. Correspondingly, the third terminal device receives the relay capabilities from the first terminal device.

[0293] Optionally, in method a, the relay capabilities sent by the first terminal device to the third terminal device can be carried in Message 1 described above. This application will not elaborate on this.

[0294] It should be noted that in method a, there may be multiple relay devices with U2N functions sending their own relay capabilities to the surrounding U2U relay devices (the first terminal device is one of the multiple relay devices with U2N functions). Figure 18 Here, only the example of the first terminal device sending relay capabilities to the third terminal device is used for illustration.

[0295] In a possible implementation, the first terminal device sends relay capabilities in a broadcast form. The third terminal devices around the first terminal device can obtain the relay capabilities of the first terminal device by listening to the broadcast message.

[0296] Step 1802: The third terminal device sends an announcement message. Correspondingly, the second terminal device receives the announcement message from the third terminal device.

[0297] Optionally, in method a, the announcement message sent by the third terminal device can be carried in Message 2 described above. This application will not elaborate on this.

[0298] In a possible implementation, the third terminal device sends an announcement message in a broadcast form. The second terminal devices around the third terminal device can obtain the announcement message by listening to the broadcast message.

[0299] Optionally, other third terminal devices around the third terminal device can also listen to the broadcast message to obtain the announcement message, generate a new announcement message according to the content in the announcement message, and broadcast the new announcement message. The new announcement message includes the identifier and capability information of the terminal device in the original announcement message. At this time, the second terminal device obtains the announcement message from the third terminal device. Correspondingly, at this time, the number of third terminal devices is multiple. Only one third terminal device is taken as an example for illustration in the figure.

[0300] In an example, the announcement message includes a U2N relay device information list, and the U2N relay device information list includes one or more of the following: the user information identifier of the first terminal device, the user information identifier of the third terminal device between the first terminal device and the third terminal device, or the hop count information between the first terminal device and the third terminal device. In addition, the announcement information also includes one or more of the following: the relay service code, the relay indication, or the discovery message type indication.

[0301] Step 1803: The second terminal device selects the first terminal device based on the announcement information.

[0302] In a possible implementation, the second terminal device can receive announcement messages broadcast by one or more third terminal devices for indicating the capability information of different U2N relay devices. The second terminal device selects the first terminal device from these different U2N relay devices according to the announcement messages of the capability information of different U2N relay devices.

[0303] The above is the process of the second terminal device discovering the first terminal device. After the second terminal device discovers the first terminal device, the second terminal device can establish a unicast connection with the first terminal device.

[0304] Step 1804: The second terminal device sends a first unicast connection establishment request message to the third terminal device. Correspondingly, the third terminal device receives the first unicast connection establishment request message from the second terminal device.

[0305] Optionally, in method a, the second terminal device sending the first unicast connection establishment request message to the third terminal device can be carried in message 3 described above, and this application will not elaborate on this.

[0306] Step 1805: The third terminal device sends a second unicast connection establishment request message to the first terminal device. Correspondingly, the first terminal device receives the second unicast connection establishment request message from the third terminal device.

[0307] Optionally, in method a, the third terminal device sending the second unicast connection establishment request message to the first terminal device can be carried in message 4 described above, and this application will not elaborate on this.

[0308] In a possible implementation, after the third terminal device receives the first unicast connection establishment request message, the user information identifier of the third terminal device and the hop count information between the second terminal device and the first terminal device are added to the first unicast connection establishment request message to generate a second unicast connection establishment request message. Optionally, in the case of multiple third terminal devices, each third terminal device adds its own user information identifier to the unicast connection establishment request message when forwarding the unicast connection establishment request message, and increments the hop count information by one.

[0309] In another possible implementation, the first unicast connection establishment request message and the second unicast connection establishment request message are the same unicast connection establishment request message. That is to say, after the third terminal device receives the first unicast connection establishment request message, it directly forwards the first unicast connection establishment request message without processing the first unicast connection establishment request message.

[0310] Step 1806: The first terminal device sends a unicast connection establishment reply message to the third terminal device. Correspondingly, the third terminal device receives the unicast connection establishment reply message from the first terminal device.

[0311] Step 1807: The third terminal device sends a unicast connection establishment reply message to the second terminal device. Correspondingly, the second terminal device receives the unicast connection establishment reply message from the first terminal device.

[0312] After the second terminal device receives the unicast connection establishment reply message, the unicast connection establishment between the second terminal device and the first terminal device is completed.

[0313] In a possible implementation, there may be multiple third terminal devices between the first terminal device and the second terminal device. At this time, the actions performed by each third terminal device can refer to the actions performed by the third terminal device in the above process, and the present application will not elaborate on this.

[0314] Method b: As Figure 19 shown, the discovery process of method b can be specifically implemented through the following steps:

[0315] Step 1901: The second terminal device sends a first request message. Correspondingly, the third terminal device 1 and the third terminal device 2 receive the first request message from the second terminal device.

[0316] Optionally, in method b, the first request message sent by the second terminal device can be carried in message 5 described above. The present application will not elaborate on this.

[0317] In a possible implementation, when the second terminal device needs to discover the first terminal device (for example, discover the first terminal device 1 and the first terminal device 2), it generates a first request message based on one or more of the user information identifier of the second terminal device and other information, the user identifier information of the first terminal device, the relay service code, the relay indication, or the discovery message type. Optionally, when the second terminal device has determined the first terminal device, the user identifier information of the first terminal device can be added to the first request message to facilitate the discovery of the first terminal device. Optionally, when the second terminal device is unsure of the first terminal device, the second terminal device may not add the user information identifier of the first terminal device to the first request message, and indicates through messages such as the relay service code and the relay indication that this discovery requires a relay device that can provide a relay service between the second terminal device and the network device and includes at least one third terminal device between the second terminal device. After the second terminal device generates the first request message, it broadcasts the first request message so that the surrounding relay devices can monitor the first request message.

[0318] In an example, the first request message sent by the second terminal device includes one or more of the following: the user information identifier of the second terminal device, the user information identifier of the first terminal device, the relay service code, the relay indication, or the discovery message type.

[0319] Step 1902: The third terminal device 1 sends a second request message. Correspondingly, the third terminal device 3 receives the second request message from the third terminal device 1.

[0320] Optionally, in mode b, the second request message sent by the third terminal device 1 can be carried in message 6 described above, and this application will not elaborate on this.

[0321] In a possible implementation, after the third terminal device 1 receives the first request message and determines that it can provide a relay service, it adds one or more of the user information identifier of the third terminal device 1 and the hop count information of the current hop to the first request message to generate a second request message. After that, the third terminal device 1 broadcasts the second request message.

[0322] In an example, the second request message includes one or more of the following: the user information identifier of the second terminal device, the user information identifier of the third terminal device 1, the user information identifier of the first terminal device 1, the relay service code, the relay indication, the relay hop count indication, or the discovery message type. Among them, the relay hop count indication is used to indicate which hop of the U2U relay device sends the request message. For example, the value of the relay hop count indication in step 1902 can be 1, which is used to indicate that the first request message is sent by the 1st hop of the U2U relay device.

[0323] Step 1903: The third terminal device 3 sends a third request message. Correspondingly, the first terminal device 1 receives the third request message.

[0324] Optionally, in Mode b, the third request message sent by the third terminal device 3 can be carried in Message 6 described above, which is not elaborated in this application.

[0325] In a possible implementation, after the third terminal device 3 receives the first request message and determines that it can provide relay services, it adds the user information identifier of the third terminal device 3 to the second request message and modifies the relay hop count indication in the second request message (for example, incrementing the hop count by 1) to generate the third request message. After that, the third terminal device 3 broadcasts the third request message.

[0326] An example is that the third request message includes one or more of the following: the user information identifier of the second terminal device, the user information identifier of the third terminal device 3, the user information identifier of the third terminal device 1, the user information identifier of the first terminal device 1, the relay service code, the relay indication, the relay hop count indication, or the discovery message type. Among them, the relay hop count indication is used to indicate which hop of the U2U relay device sends the request message. For example, the value of the relay hop count indication in Step 1903 can be 2, indicating that the third request message is sent by the 2nd-hop U2U relay device.

[0327] Step 1904: The first terminal device 1 sends a first response message to the third terminal device 3. Correspondingly, the third terminal device 3 receives the first response message from the first terminal device 1.

[0328] Optionally, in Mode b, the first response message sent by the first terminal device 1 to the third terminal device 3 can be carried in Message 1 described above. This is not elaborated in this application.

[0329] In a possible implementation, after the first terminal device 1 receives the third request message, it determines based on the relay service code and relay indication in the third request message that the third request message is used to request to provide relay services between the second terminal device and the network device. If the first terminal device 1 determines that it can provide corresponding relay services for the second terminal device, it generates a first response message and sends the first response message to the third terminal device 3.

[0330] An example is that the first response message includes one or more of the following: the user identification information of the first terminal device, the user identification information of the second terminal device, the relay service code, the relay indication, or the discovery message type.

[0331] Step 1905: The third terminal device 3 sends a second response message to the third terminal device 1. Correspondingly, the third terminal device 1 receives the second response message from the third terminal device 3.

[0332] Optionally, in mode b, the second response message sent by the third terminal device 3 to the third terminal device 1 can be carried in the message 2 described above. This application will not elaborate on this.

[0333] In a possible implementation, after the third terminal device 3 receives the first response message from the first terminal device 1, if it determines that the first response message is the response information that needs to be forwarded to the second terminal device, the third terminal device 3 adds the user identification information of the third terminal device 3 to the first response message to generate a second response message. The third terminal device 3 sends the second response message to the third terminal device 1.

[0334] An example is that the second response message includes one or more of the following: the user identification information of the third terminal device 3, the user identification information of the first terminal device 1, the user identification information of the second terminal device, the relay service code, the relay indication, or the discovery message type.

[0335] Step 1906: The third terminal device 1 sends a third response message to the second terminal device. Correspondingly, the second terminal device receives the third response message from the third terminal device 1.

[0336] Optionally, in mode b, the third request message sent by the third terminal device 3 can be carried in the message 2 described above. This application will not elaborate on this.

[0337] In a possible implementation, after the third terminal device 1 receives the second response message from the first terminal device 3, if it determines that the second response message is the response information that needs to be forwarded to the second terminal device, the third terminal device 1 adds the user identification information of the third terminal device 1 to the second response message to generate a third response message. The third terminal device 1 sends the third response message to the second terminal device.

[0338] An example is that the third response message includes one or more of the following: the user identification information of the third terminal device 1, the user identification information of the third terminal device 3, the user identification information of the first terminal device 1, the user identification information of the second terminal device, the relay service code, the relay indication, or the discovery message type.

[0339] Step 1907: The third terminal device 2 sends a fourth request message. Correspondingly, the third terminal device 4 receives the fourth request message from the third terminal device 2.

[0340] Optionally, in Mode b, the fourth request message sent by the third terminal device 2 may be carried in Message 6 described above, and this application will not elaborate on this.

[0341] In a possible implementation, after the third terminal device 2 receives the first request message and determines that it can provide relay services, it adds one or more of the user information identifier of the third terminal device 2 and the hop count information of the current hop to the first request message to generate a fourth request message. After that, the third terminal device 2 broadcasts the fourth request message.

[0342] As an example, the fourth request message includes one or more of the following: the user information identifier of the second terminal device, the user information identifier of the third terminal device 2, the user information identifier of the first terminal device 2, the relay service code, the relay indication, the relay hop count indication, or the discovery message type.

[0343] Step 1908: The third terminal device 4 sends a fifth request message. Correspondingly, the first terminal device 2 receives the fifth request message from the third terminal device 4.

[0344] Optionally, in Mode b, the fifth request message sent by the third terminal device 4 may be carried in Message 6 described above, and this application will not elaborate on this.

[0345] In a possible implementation, after the third terminal device 4 receives the fourth request message and determines that it can provide relay services for the second terminal device, it adds the user information identifier of the third terminal device 4 to the fourth request message and modifies the relay hop count indication in the fourth request message (for example, increment the hop count by 1) to generate a fifth request message. After that, the third terminal device 4 broadcasts the fifth request message.

[0346] As an example, the fifth request message includes one or more of the following: the user information identifier of the second terminal device 2, the user information identifier of the third terminal device 4, the user information identifier of the third terminal device 2, the user information identifier of the first terminal device, the relay service code, the relay indication, the relay hop count indication, or the discovery message type.

[0347] Step 1909: The first terminal device 2 sends a fourth response message to the third terminal device 4. Correspondingly, the third terminal device 4 receives the fourth response message from the first terminal device 2.

[0348] Optionally, in Mode b, the fourth response message sent by the first terminal device 2 to the third terminal device 4 may be carried in Message 1 described above, and this application will not elaborate on this.

[0349] In a possible implementation, after the first terminal device 2 receives the fifth request message, it determines, based on the relay service code and the relay indication in the fifth request message, that the fifth request message is used to request a relay service between the second terminal device and the network device, and the relay device includes at least one third terminal device between the first terminal device 2 and the second terminal device. If the first terminal device 2 determines that it can provide the corresponding relay service for the second terminal device, it generates a fourth response message and sends the fourth response message to the third terminal device 3.

[0350] In an example, the fourth response message includes one or more of the following: user identification information of the first terminal device, user identification information of the second terminal device, relay service code, relay indication, or discovery message type.

[0351] Step 1910: The third terminal device 4 sends a fifth response message to the third terminal device 2. Correspondingly, the third terminal device 2 receives the fifth response message from the third terminal device 4.

[0352] Optionally, in mode b, the fifth response message sent by the third terminal device 4 to the third terminal device 2 may be carried in the message 2 described above, and this application will not elaborate on this.

[0353] In a possible implementation, after the third terminal device 4 receives the fourth response message from the first terminal device 2, if it determines that the fourth response message is response information that needs to be forwarded to the second terminal device, the third terminal device 4 adds its own user identification information to the fourth response message to generate a fifth response message. The third terminal device 4 sends the fifth response message to the third terminal device 2.

[0354] In an example, the fifth response message includes one or more of the following: user identification information of the third terminal device 4, user identification information of the first terminal device, user identification information of the second terminal device, relay service code, relay indication, or discovery message type.

[0355] Step 1911: The third terminal device 2 sends a sixth response message to the second terminal device. Correspondingly, the second terminal device receives the sixth response message from the third terminal device 2.

[0356] Optionally, in mode b, the sixth response message sent by the third terminal device 2 to the second terminal device may be carried in the message 2 described above, and this application will not elaborate on this.

[0357] In a possible implementation, after the third terminal device 2 receives the fifth response message from the first terminal device 4 and determines that the fifth response message is response information that needs to be forwarded to the second terminal device, the third terminal device 2 adds the user identification information of the third terminal device 2 to the fifth response message to generate a sixth response message. The third terminal device 2 sends the sixth response message to the second terminal device.

[0358] An example is that the third response message includes one or more of the following: the user identification information of the third terminal device 2, the user identification information of the third terminal device 4, the user identification information of the first terminal device 2, the user identification information of the second terminal device, the relay service code, the relay indication, or the discovery message type.

[0359] Step 1912: The second terminal device determines the first terminal device based on the third response message and the sixth response message.

[0360] In a possible implementation, after the second terminal device receives the third response message and the sixth response message, it determines according to the third response message that the first terminal device 1 can provide relay services for the second terminal device, and determines according to the sixth response message that the first terminal device 2 can provide relay services for the second terminal device. At this time, the second terminal device can select one of the first terminal device 1 and the first terminal device 2 as the first terminal device according to its own requirements, network conditions and other parameters. For example, if the second terminal device selects the first terminal device 1 as the first terminal device, the second terminal device sends a unicast connection establishment request message to the first terminal device 1 to establish a unicast connection between the second terminal device and the first terminal device 1.

[0361] After that, the first terminal device, the second terminal device, and the third terminal device perform steps similar to those recorded in steps 1804 - 1807 above to establish a unicast connection between the first terminal device and the third terminal device.

[0362] It should be noted that in the figure, only the case where there are two third terminal devices between the first terminal device and the second terminal device is taken as an example for illustration. In specific implementation, there can be at least one third terminal device between the first terminal device and the second terminal device, and the present application does not limit the number of third terminal devices.

[0363] Method c, as Figure 20 shown, the discovery process of method c can be specifically implemented through the following steps:

[0364] Step 2001: The second terminal device sends a first unicast connection establishment request message. Correspondingly, the third terminal device 1 receives the first unicast connection establishment request message from the second terminal device.

[0365] Optionally, the first unicast connection establishment request message sent by the second terminal device may be carried in Message 3 described above, and details are not elaborated in this application.

[0366] An example is that the first unicast connection establishment request message includes one or more of the following: the user information identifier of the second terminal device, the user information identifier of the first terminal device, the relay service code, the relay indication, or security-related information. Among them, the relay service code is used to indicate a request to provide a multi-hop relay service; the relay indication is used to indicate that the U2U relay device can forward DCR messages; and the security-related information is used to indicate a secure connection between the END device 1 and the relay device.

[0367] Step 2002: The third terminal device 1 sends a second unicast connection establishment request message. Correspondingly, the third terminal device 3 receives the second unicast connection establishment request message from the third terminal device 1.

[0368] Optionally, the second unicast connection establishment request message sent by the third terminal device 1 may be carried in Message 4 described above, and details are not elaborated in this application.

[0369] Step 2003: The third terminal device 3 sends a third unicast connection establishment request message. Correspondingly, the first terminal device 1 receives the third unicast connection establishment request message.

[0370] Optionally, the third unicast connection establishment request message sent by the third terminal device 3 may be carried in Message 4 described above, and details are not elaborated in this application.

[0371] Step 2004: The first terminal device 1 sends a unicast connection establishment request response message to the third terminal device 3. Correspondingly, the third terminal device 3 receives the unicast connection establishment request response message from the first terminal device 1.

[0372] Optionally, the unicast connection establishment request response message sent by the first terminal device 1 to the third terminal device 3 may be carried in Message 1 described above, and details are not elaborated in this application.

[0373] Step 2005: The third terminal device 3 sends a unicast connection establishment request response message to the third terminal device 1. Correspondingly, the third terminal device 1 receives the unicast connection establishment request response message from the third terminal device 3.

[0374] Optionally, the second unicast connection establishment request response message sent by the third terminal device 3 to the third terminal device 1 may be carried in Message 2 described above, and details are not elaborated in this application.

[0375] Step 2006: The third terminal device 1 sends a unicast connection establishment request response message to the second terminal device. Correspondingly, the second terminal device receives the unicast connection establishment request response message from the third terminal device 1.

[0376] Optionally, the unicast connection establishment request response message sent by the first terminal device 1 to the third terminal device 3 can be carried in the message 2 described above, which is not elaborated in this application.

[0377] Optionally, the unicast connection establishment request response message sent by the third terminal device 2 to the second terminal device can be carried in the message 2 described above, which is not elaborated in this application.

[0378] Step 2007: The second terminal device determines to establish a unicast connection with the first terminal device based on the unicast connection establishment request response message.

[0379] After the second terminal device determines the first terminal device, the unicast connection establishment between the second terminal device and the first terminal device is completed.

[0380] In a possible implementation Figure 20 Take the case where the second terminal device initiates a unicast connection establishment request to the first terminal device through a relay link as an example. In specific implementation, the second terminal device can initiate a unicast connection establishment to the first terminal device through multiple relay links, and the first terminal device selects one relay link from the multiple relay links to send the unicast connection establishment request response message. This application does not make any limitations in this regard.

[0381] It should be noted that the above Figures 18 - 20 mainly describes the discovery and unicast establishment process between the second terminal device and the first terminal device. In the case where the third terminal device is a U2N relay device with one or more hops between it and the network device, the second terminal device can discover the third terminal device, and determine the first terminal device connected to the third terminal device through the third terminal device, and then establish a unicast connection with the first terminal device. Among them, the process of the second terminal device discovering the third terminal device is similar to the process of the second terminal device discovering the first terminal device described above, which is not elaborated in this application.

[0382] Combined with Figure 14, in some scenarios, the third terminal device is a terminal device that has established a unicast connection with the first terminal device and thus accessed the network device. The third terminal device is directly connected to the first terminal device or establishes a unicast connection through multiple relay devices. In this scenario, when the second terminal device needs to access the network device, it can access the network device by discovering the third terminal device. Specifically: The second terminal device discovers the third terminal device through a discovery process and establishes a unicast connection with the third terminal device. After establishing a unicast connection between the second terminal device and the third terminal device, the second terminal device can also establish a unicast connection with the first terminal device to transmit indication information between the first terminal device and the third terminal device, including but not limited to one or more of the Uu RLF or paging messages of the first terminal device.

[0383] In a possible implementation manner, the process of the second terminal device establishing a unicast connection with the first terminal device includes: After the second terminal device establishes a unicast connection with the third terminal device, the third terminal device sends the identifier of the second terminal device (such as the layer 2 identifier of the second terminal device, the user information identifier of the second terminal device) to the first terminal device. The first terminal device sends a unicast connection establishment request to the second terminal device according to the identifier of the second terminal device to establish a unicast connection between the second terminal device and the first terminal device. Among them, the process of the first terminal device sending a unicast connection establishment request to the second terminal device to establish a unicast connection between the second terminal device and the first terminal device is similar to the above Figure 18 steps 1804 - step 1807, the only difference is that the devices for sending and receiving the unicast connection establishment request message and the unicast connection establishment response message are different, and the specific process can refer to the above Figure 18 content recorded in steps 1804 - step 1807, and this application will not elaborate on this.

[0384] In another possible implementation manner, the process of the second terminal device establishing a unicast connection with the first terminal device further includes: After the second terminal device establishes a unicast connection with the third terminal device, the third terminal device sends the identifier of the first terminal device (such as the layer 2 identifier of the first terminal device, the user information identifier of the first terminal device) to the second terminal device. The second terminal device sends a unicast connection establishment request to the first terminal device according to the identifier of the first terminal device to establish a unicast connection between the second terminal device and the first terminal device. Among them, the process of the second terminal device sending a unicast connection establishment request to the first terminal device to establish a unicast connection between the second terminal device and the first terminal device can refer to the above Figure 18 steps 1804 - step 1807, and this application will not elaborate on this again.

[0385] It should be noted that the process by which the second terminal device discovers the third terminal device through the discovery process can refer to the Figure 5 model A described in the Figure 6 or the method in model B described in the Figure 7 This application will not elaborate on this. The process of the second terminal device establishing a unicast connection with the third terminal device can refer to the

[0386] way described in the above description of the related technology. This application will not elaborate on this either.

[0387] Figure 21 The above has elaborated in detail on the discovery process and the unicast connection establishment process in the communication method provided by the embodiments of this application. Figure 21 As shown in

[0388] Step 2101: The second terminal device sends a fifth data packet to the third terminal device. Correspondingly, the third terminal device receives the fifth data packet from the second terminal device.

[0389] Among them, the fifth data packet includes first data or a first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

[0390] Optionally, the fifth data packet further includes a first identifier, and the first identifier is used to identify the radio bearer corresponding to the data of the second terminal device transmitted between the first terminal device and the second terminal device.

[0391] In a possible implementation, the second terminal device sends the fifth data packet according to the fifth configuration. The fifth configuration includes one or more of the following: a first local identifier, a fifth RLC channel, a first identifier, or an identifier of the second terminal device. The fifth RLC channel is a channel associated with the radio bearer corresponding to the first data. The fifth RLC channel is a PC5 relay RLC channel. There is a corresponding relationship between the first identifier and the fifth RLC channel.

[0392] In a specific implementation manner, after the second terminal device obtains the first data, it generates a fifth data packet according to the fifth configuration. For example, the second terminal device receives the first data from an upper layer (such as PDCP), and the first data belongs to a first radio bearer. According to the fifth configuration, the second terminal device determines a first local identifier and a first identifier in the fifth data packet, and determines the RLC channel associated with the radio bearer corresponding to the first data (i.e., the above-mentioned fifth RLC channel) according to the fifth configuration. The second terminal device sends the fifth data packet to the third terminal device on the fifth RLC channel.

[0393] In a possible implementation manner, the first local identifier in the embodiments of the present application includes a first local identifier 1 (denoted as local ID1) and a first local identifier 2 (denoted as local ID2). The first local identifier 1 is used to identify the second terminal device between the second terminal device and the first terminal device; the first local identifier 2 is used to identify the first terminal device between the second terminal device and the first terminal device.

[0394] Step 2102: The third terminal device sends a first data packet to the first terminal device. Correspondingly, the first terminal device receives the first data packet from the third terminal device.

[0395] Optionally, in the embodiments of the present application, the third terminal device sends the first data packet to the first terminal device according to the third configuration. The third configuration includes one or more of the following: a first local identifier, a third RLC channel, a first identifier, or an identifier of the second terminal device. Optionally, the first data packet sent by the third terminal device to the first terminal device and the fifth data packet sent by the second terminal device to the third terminal device may be the same data packet (for example, the content in the fifth data packet and the first data packet may be the same), or may be different data packets, and the present application does not limit this.

[0396] In a possible implementation manner, after the third terminal device receives the fifth data packet from the second terminal device on the fifth RLC channel, it parses the header of the fifth data packet to determine the first local identifier and / or the first identifier in the fifth data packet. The third terminal device determines the third configuration corresponding to the fifth data packet according to the first local identifier and / or the first identifier in the fifth data packet, and the uplink RLC channel associated with the first identifier on the third terminal device side (which is a PC5 relay RLC channel, such as the third RLC channel). The third terminal device sends the first data packet to the first terminal device on the RLC channel associated with the first identifier on the third terminal device side according to the third configuration corresponding to the fifth data packet.

[0397] Step 2103: The first terminal device sends a second data packet to the network device. Correspondingly, the network device receives the second data packet from the first terminal device.

[0398] Wherein, the second data packet includes one or more of the following: first data, or a second local identifier; the second local identifier is used to identify the second terminal device between the first terminal device and the network device.

[0399] Optionally, the second data packet further includes a second identifier, and the second identifier is used to identify the radio bearer corresponding to the data of the second terminal device transmitted between the network device and the first terminal device.

[0400] In a possible implementation, the network device in the embodiments of the present application may be an O-CU or a CU. When the network device is an O-CU, the above step S2103 may be replaced with: the first terminal device sends the second data packet to the O-CU through the O-DU. Correspondingly, the O-CU receives the first data from the first terminal device through the O-DU. In a possible manner, the first terminal device sends the second data packet to the O-DU, and the O-DU obtains the first data based on the second data packet and delivers the first data to the O-CU; or the first terminal device sends the second data packet to the O-DU, and the O-DU delivers the second data packet to the O-CU. When the network device is a CU, the above step S2103 may be replaced with: the first terminal device sends the second data to the CU through the DU. Correspondingly, the CU receives the first data from the first terminal device through the DU. In a possible manner, the first terminal device sends the second data packet to the DU, and the DU obtains the first data based on the second data packet and delivers the first data to the CU; or the first terminal device sends the second data packet to the DU, and the DU delivers the second data packet to the CU.

[0401] In a possible implementation, after receiving the fifth data packet, the first terminal device determines a first configuration according to the first local identifier and / or the first identifier in the fifth data packet, and the first configuration includes the second local identifier. Exemplarily, the first terminal device determines that the fifth data packet corresponds to the first radio bearer of the second terminal device according to the first local identifier and / or the first identifier in the fifth data packet, and the first terminal device determines the first configuration associated with the first radio bearer of the second terminal device. In addition, the first terminal device generates a second data packet according to the fifth data packet and the second local identifier and / or the second identifier. Further, the first terminal device sends the second data packet to the network device according to the first RLC channel indicated by the first configuration. The first configuration indicates the mapping relationship between the first RLC channel and the radio bearer corresponding to the first data. For example, the first RLC channel is a Uu relay RLC channel.

[0402] In a specific implementation manner, after the first terminal device receives the fifth data packet, it parses the header of the fifth data packet to determine that the fifth data packet includes a first local identifier and / or a first identifier. The first terminal device determines that the first data is the radio bearer data of the second terminal device based on the first local identifier. The first terminal device determines, according to the first identifier, that the first data corresponds to a first radio bearer of the second terminal device. After that, the first terminal device determines an associated first configuration, where the first configuration includes a second local identifier of the second terminal device, a second identifier of the first radio bearer, and the correspondence between the first radio bearer of the second terminal device and the first RLC channel. Based on the first configuration, the first terminal device generates a second data packet, and the second data packet includes the second local identifier and the second identifier. The first terminal device sends the second data packet to the network device via the first RLC channel associated with the second identifier.

[0403] It should be noted that in the embodiments of the present application, the first local identifier and / or the first identifier, and the second local identifier and / or the second identifier can both be in the header of the data packet.

[0404] Above, the process of uplink data transmission among the first terminal device, the second terminal device, the third terminal device, and the network device is described. Next, the process of downlink data transmission among the first terminal device, the second terminal device, the third terminal device, and the network device is described.

[0405] As Figure 21 shown, the downlink data packet forwarding process can be specifically implemented through the following steps 2104 to 2106.

[0406] Step 2104: The network device sends a third data packet to the first terminal device. Correspondingly, the first terminal device receives the third data packet from the network device.

[0407] Among them, the third data packet includes one or more of the following: second data, or a second local identifier; the second local identifier is used to identify the second terminal device between the first terminal device and the network device. Optionally, the third data packet further includes a second identifier.

[0408] As described above, in a possible implementation, the network device in the embodiments of the present application may be an O-CU or a CU. When the network device is an O-CU, the above step S2104 may be replaced with: the O-CU sends the second data to the first terminal device through the O-DU. Correspondingly, the first terminal device receives the third data packet from the O-CU through the O-DU. In a possible way, the O-CU sends the second data to the O-DU, and the O-DU generates a third data packet according to the second data and sends the third data packet to the first terminal device. Or the O-CU sends the third data packet to the O-DU, and the O-DU sends the third data packet to the first terminal device. When the network device is a CU, the above step S2104 may be replaced with: the CU sends the third data packet to the first terminal device through the DU. Correspondingly, the first terminal device receives the third data packet from the CU through the DU. In a possible way, the CU sends the second data to the DU, and the DU generates a third data packet according to the second data and sends the third data packet to the first terminal device. Or the CU sends the third data packet to the DU, and the DU sends the third data packet to the first terminal device.

[0409] Step 2105: The first terminal device sends a fourth data packet to the third terminal device. Correspondingly, the third terminal device receives the fourth data packet from the first terminal device.

[0410] The fourth data packet includes one or more of the following: the second data, or the first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

[0411] Optionally, the fourth data packet further includes a first identifier.

[0412] In a possible implementation, after the first terminal device receives the third data packet from the network device, it determines a second configuration according to the second local identifier and / or the second identifier in the third data packet, and the second configuration includes the first local identifier. Exemplarily, the first terminal device determines, according to the second local identifier and / or the second identifier in the third data packet, that the third data packet corresponds to the second radio bearer of the second terminal device, and the first terminal device determines the second configuration associated with the second radio bearer of the second terminal device. In addition, the first terminal device generates a fourth data packet according to the third data packet, the first local identifier, and / or the first identifier. Further, the first terminal device sends the fourth data packet to the third terminal device according to the second RLC channel indicated by the second configuration. The second RLC channel is the channel associated with the radio bearer corresponding to the fourth data. For example, the second RLC channel is the PC5 relay RLC channel.

[0413] In a specific implementation manner, after receiving the third data packet, the first terminal device parses the third data packet to determine that the third data packet includes a second local identifier and / or a second identifier. The first terminal device determines that the second data is the radio bearer data of the second terminal device based on the second local identifier. The first terminal device determines that the second data corresponds to the second radio bearer of the second terminal device according to the second identifier. After that, the first terminal device determines an associated second configuration, where the second configuration includes the first local identifier of the second terminal device, the first identifier of the second radio bearer, and the correspondence between the second radio bearer of the second terminal device and the second RLC channel. Based on the second configuration, the first terminal device generates a fourth data packet, and the fourth data packet includes the first local identifier and the first identifier. The first terminal device sends the fourth data packet to the third terminal device via the second RLC channel associated with the first identifier.

[0414] Step 2106: The third terminal device sends a sixth data packet to the second terminal device. Correspondingly, the second terminal device receives the sixth data packet from the third terminal device.

[0415] Among them, the sixth data packet includes one or more of the following: the second data, or the first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

[0416] Optionally, the sixth data packet further includes the first identifier.

[0417] Optionally, in the embodiments of the present application, the third terminal device sends the sixth data packet to the second terminal device according to the fourth configuration. The fourth configuration includes one or more of the following: the first local identifier, the fourth RLC channel, the second identifier, or the identifier of the second terminal device. Optionally, the sixth data packet sent by the third terminal device to the first terminal device and the fourth data packet sent by the first terminal device to the third terminal device may be the same data packet (for example, a new data packet generated by the third terminal device according to the fourth data packet, and the contents of the fourth data packet and the new data packet may be the same), or may be different data packets, and the present application does not make a limitation on this.

[0418] In a possible implementation manner, after receiving the fourth data packet, the third terminal device parses the packet header of the fourth data packet to determine the first local identifier and / or the first identifier in the fourth data packet. The third terminal device determines the fourth configuration corresponding to the fourth data packet according to the first local identifier and / or the first identifier in the fourth data packet, and the downlink RLC channel (which is a PC5 relay RLC channel, such as the fourth RLC channel) associated with the first identifier on the third terminal device side. The third terminal device sends the sixth data packet to the second terminal device on the downlink RLC channel associated with the first identifier on the third terminal device side according to the fourth configuration corresponding to the fourth data packet.

[0419] It should be noted that in the above embodiments, only one third terminal device is included between the first terminal device and the second terminal device as an example for illustration. When the number of third terminal devices is multiple, the actions performed by each third terminal device are similar, and can be understood with reference to the actions of the above one third terminal device. This application will not elaborate on this.

[0420] In a possible implementation manner, the embodiments of the present application provide a protocol stack architecture used when the second terminal device and the network device perform data transmission. In the protocol stack used when the second terminal device and the network device perform data transmission: the control plane protocol stack of the sidelink between the first terminal device and the second terminal device is as Figure 22 shown, the user plane protocol stack between the network device and the second terminal device is as Figure 23 shown, and the control plane protocol stack between the network device and the second terminal device is as Figure 24 shown.

[0421] It should be noted that the above Figure 21 data forwarding process can be based on the discovery process and connection establishment process provided in the above embodiments of the present application, or can be based on other processes. The embodiments of the present application do not limit this.

[0422] In the above data forwarding process, each terminal device needs to forward according to the forwarding configuration corresponding to the data packet.

[0423] Figure 25 This is a schematic flowchart of a communication method provided by the embodiments of the present application. In the embodiments of the present application, the first terminal device, the second terminal device, and at least one third terminal device need to determine the corresponding configuration for data forwarding. Hereinafter, in combination with the process of the first terminal device, the second terminal device, and at least one third terminal device determining the corresponding configuration for data forwarding, the functions and actions performed by each device in the communication system provided by the embodiments of the present application will be introduced, as Figure 25 shown, including the following steps:

[0424] Step 2501, the second device determines the data forwarding configuration and sends data according to the data forwarding configuration.

[0425] Among them, the second device may be the above first terminal device, second terminal device, or third terminal device. The processes for different terminal devices to determine the data forwarding configuration are different, and the determined data forwarding configurations are also different. The following will be described separately:

[0426] Configuration for the first terminal device:

[0427] The configuration of the first terminal device includes an uplink configuration (such as the above-mentioned first configuration) for forwarding uplink data packets, and a downlink configuration (such as the above-mentioned second configuration) for forwarding downlink data packets.

[0428] The uplink configuration of the first terminal device includes one or more of the following: the identifier of the second terminal device, the second local identifier, the second identifier, or the identifier of RLC channel 1. Optionally, the uplink configuration of the first terminal device can also characterize the association relationship with the identifier of RLC channel 1. At this time, the process of the first terminal device performing uplink forwarding based on the uplink configuration includes: after the first terminal device receives the uplink data packet 1 (which can be a data packet sent by the third terminal device to the first terminal device), it parses the packet header of the data packet 1 to determine the first identifier and / or the first local identifier carried in the packet header of the data packet 1. The first terminal device determines that the data packet 1 is a data packet sent by the second terminal device based on the first local identifier, and determines the identifier of the second terminal device (such as the layer 2 identifier of the second terminal device). The first terminal device determines the uplink configuration including the identifier of the second terminal device, and obtains the second identifier, the second local identifier, and the identifier of RLC channel 1 in the uplink configuration. The first terminal device determines the data packet 2 based on the data packet 1 and the second identifier and the second local identifier, and sends the data packet 2 to the network device based on RLC channel 1 associated with the second identifier. The data packet 2 includes the second identifier and the second local identifier.

[0429] The downlink configuration of the first terminal device includes one or more of the following: the identifier of the second terminal device, the identifier of the first terminal device, the first local identifier, the first identifier, or the identifier of RLC channel 2. Optionally, the downlink configuration of the first terminal device can also characterize the association relationship between the first identifier and the identifier of RLC channel 2. At this time, the process of the first terminal device performing downlink forwarding based on the downlink configuration includes: after the first terminal device receives the downlink data packet 3, it parses the packet header of the data packet 3 to determine the second identifier and / or the second local identifier carried in the packet header of the data packet 3. The first terminal device determines that the data packet 3 is a data packet sent to the second terminal device based on the second local identifier, and determines the identifier of the second terminal device (such as the layer 2 identifier of the second terminal device). The first terminal device determines the downlink configuration including the identifier of the second terminal device, and obtains the first identifier, the first local identifier, and the identifier of RLC channel 2 in the downlink configuration. The first terminal device determines the data packet 4 based on the data packet 3 and the first identifier and the first local identifier, and sends the data packet 4 to the third terminal device based on RLC channel 2 associated with the first identifier. The data packet 4 includes the first identifier and the first local identifier.

[0430] In a possible implementation, the format of the data forwarded between the first terminal device and the network device is as Figure 26As shown, the format of the data forwarded between the first terminal device and the second terminal device is as follows Figure 27 as shown.

[0431] Configuration for the third terminal device:

[0432] The configuration of the third terminal device includes an uplink configuration (such as the above-mentioned third configuration) for forwarding uplink data packets, and a downlink configuration (such as the above-mentioned fourth configuration) for forwarding downlink data packets.

[0433] The uplink configuration of the third terminal device includes one or more of the following: the identifier of the first terminal device, the identifier of the second terminal device, the identifier of the third terminal device, the first identifier, the first local identifier, or the identifier of RLC channel 3. Optionally, the uplink configuration of the third terminal device can also characterize the association relationship between the first identifier and the identifier of RLC channel 3. At this time, the process of the third terminal device performing uplink forwarding based on the uplink configuration includes: after the third terminal device receives data packet 1 (which can be a data packet sent by the second terminal device or the third terminal device in the previous hop in the uplink direction), it parses the packet header of data packet 1 to determine the first identifier and the first local identifier carried in the packet header of data packet 1. The third terminal device determines that data packet 1 is a data packet sent by the second terminal device based on the first local identifier, and determines the identifier of the second terminal device. The third terminal device determines the uplink configuration including the identifier of the second terminal device, and obtains the identifier of RLC channel 3 that has an association relationship with the first identifier in the uplink configuration. The third terminal device continues to forward data packet 1 based on RLC channel 3 (for example, sending it to the first terminal device or the third terminal device in the next hop).

[0434] The downlink configuration of the third terminal device includes one or more of the following: the identifier of the first terminal device, the identifier of the second terminal device, the identifier of the third terminal device, the first identifier, the first local identifier, or the identifier of RLC channel 4. Optionally, the downlink configuration of the third terminal device can also characterize the association relationship between the second identifier and the identifier of RLC channel 4. At this time, the process of the third terminal device performing downlink forwarding based on the downlink configuration includes: after the third terminal device receives data packet 4 (which can be a data packet sent by the first terminal device or the third terminal device in the previous hop in the downlink direction), it parses the packet header of data packet 4 to determine the first identifier and the first local identifier carried in the packet header of data packet 4. The third terminal device determines that data packet 4 is a data packet sent by the second terminal device based on the first local identifier, and determines the identifier of the second terminal device. The third terminal device determines the downlink configuration including the identifier of the second terminal device, and obtains the identifier of RLC channel 4 that has an association relationship with the first identifier in the downlink configuration. The third terminal device continues to forward data packet 4 based on RLC channel 4 (for example, sending it to the second terminal device or the third terminal device in the next hop in the downlink direction).

[0435] Configuration for the second terminal device:

[0436] Since the second terminal device is the last hop in the downlink direction, the second terminal device does not need to perform downlink forwarding to other devices. Therefore, the configuration of the second terminal device does not include the downlink configuration for downlink forwarding, but only includes the downlink configuration for uplink transmission (such as the above-mentioned fifth configuration).

[0437] The uplink configuration of the second terminal device includes one or more of the following: the identifier of the first terminal device, the identifier of the second terminal device, the first identifier, the first local identifier, and the identifier of RLC channel 5. Optionally, the uplink configuration of the second terminal device can also characterize the association relationship between the first identifier and the identifier of RLC channel 5. At this time, the process of the second terminal device performing uplink transmission based on the uplink configuration includes: when the second terminal device determines that it needs to send uplink data to the network device, the second terminal device obtains the uplink configuration of the second terminal device, determines the first identifier and the first local identifier in the uplink configuration of the second terminal device, and encapsulates the first identifier and the first local identifier into the packet header of the data packet to obtain data packet 1. The second terminal device sends data packet 1 to the third terminal device according to RLC channel 5 associated with the first identifier.

[0438] Above, the data forwarding configurations of the first terminal device, the second terminal device, and the third terminal device have been described in detail respectively.

[0439] In a possible implementation, the uplink configuration and / or downlink configuration of each of the above terminal devices are determined based on the corresponding QoS information.

[0440] For example, the uplink configuration of the first terminal device is determined according to the QoS information between the first terminal device and the network device. Optionally, the process of determining the uplink configuration information of the first terminal includes: the network device determines the QoS information between the first terminal device and the network device, and determines the uplink configuration of the first terminal device according to the QoS information; the network device sends the uplink configuration of the first terminal device to the first terminal device. In addition, the network device can also determine the configuration information of RLC channel 1 according to the QoS information between the first terminal device and the network device, and send the configuration information of RLC channel 1 to the first terminal device, so that the first terminal device configures RLC channel 1 according to the configuration information of RLC channel 1.

[0441] The downlink configuration information of the first terminal device is determined according to the QoS information between the first terminal device and the adjacent third terminal device. Optionally, the network device determines the downlink QoS information between the first terminal device and the second terminal device, and sends the downlink QoS information between the first terminal device and the second terminal device to the first terminal device. The first terminal device determines the QoS information between the first terminal device and the adjacent third terminal device according to the downlink QoS information between the first terminal device and the second terminal device, and determines the downlink configuration information of the first terminal device based on the QoS information between the first terminal device and the adjacent third terminal device. In addition, the first terminal device may also determine the configuration information of RLC channel 2 according to the QoS information between the first terminal device and the adjacent third terminal device, and configure RLC channel 2 according to the configuration information of RLC channel 2. It should be noted that after the first terminal device obtains the downlink QoS information between the first terminal device and the second terminal device, the first terminal device may send the downlink QoS information between the first terminal device and the second terminal device to the adjacent terminal device; so that the adjacent terminal device determines the QoS information between the first terminal device and the adjacent third terminal device according to the downlink QoS information between the first terminal device and the second terminal device, and sends the QoS information between the first terminal device and the adjacent third terminal device to the first terminal device. The first terminal device may also obtain the QoS information between the first terminal device and the adjacent third terminal device in other ways, which is not limited in this application. In addition, the first terminal device may also obtain the downlink configuration information and / or the configuration information of RLC channel 2 of the first terminal device from other devices (such as network devices or adjacent terminal devices), which is not limited in this application.

[0442] The uplink configuration of the second terminal device is determined according to the uplink QoS information between the second terminal device and the next-hop terminal device in the uplink direction. Optionally, the network device determines the uplink QoS information between the first terminal device and the second terminal device, and sends the uplink QoS information between the first terminal device and the second terminal device to the second terminal device. The second terminal device determines the uplink QoS information between the second terminal device and the next-hop terminal device in the uplink direction based on the uplink QoS information between the first terminal device and the second terminal device, and determines the uplink configuration of the second terminal device based on the uplink QoS information between the second terminal device and the next-hop terminal device in the uplink direction. In addition, the second terminal device determines the configuration information of RLC channel 5 based on the uplink QoS information between the second terminal device and the next-hop terminal device in the uplink direction, and configures RLC channel 5 based on the configuration information of RLC channel 5. It should be noted that the embodiments of the present application do not limit the device that determines the uplink QoS information between the second terminal device and the next-hop terminal device in the uplink direction, and the device that determines the uplink configuration of the second terminal device and / or the configuration information of RLC channel 5 based on the uplink QoS information between the second terminal device and the next-hop terminal device in the uplink direction. The device that executes these processes may be the second terminal device, or the next-hop terminal device in the uplink direction of the second terminal device, or other devices, and the present application does not make any limitations in this regard.

[0443] The uplink configuration of the third terminal device is determined according to the uplink QoS information between the third terminal device and the next-hop terminal device in the uplink direction. Optionally, the third terminal device can obtain the uplink QoS information between the third terminal device and the next-hop terminal device in the uplink direction, and determine the uplink configuration of the third terminal device based on the uplink QoS information between the third terminal device and the next-hop terminal device in the uplink direction. In addition, the third terminal device can also determine the configuration information of RLC channel 3 based on the uplink QoS information between the third terminal device and the next-hop terminal device in the uplink direction, and configure RLC channel 3 according to the configuration information of RLC channel 3. It should be noted that the embodiments of the present application do not limit the device that determines the uplink QoS information between the third terminal device and the next-hop terminal device in the uplink direction, and the device that determines the uplink configuration of the third terminal device and / or the configuration information of RLC channel 3 based on the uplink QoS information between the third terminal device and the next-hop terminal device in the uplink direction. The device that executes these processes may be the third terminal device, or the next-hop terminal device in the uplink direction of the third terminal device, or other devices, and the present application does not make any limitations in this regard.

[0444] The downlink configuration of the third terminal device is determined according to the downlink QoS information between the third terminal device and the next-hop terminal device in the downlink direction. Optionally, the third terminal device may obtain the downlink QoS information between the third terminal device and the next-hop terminal device in the downlink direction, and determine the downlink configuration of the third terminal device based on the downlink QoS information between the third terminal device and the next-hop terminal device in the downlink direction. In addition, the third terminal device may also determine the configuration information of the RLC channel 4 based on the downlink QoS information between the third terminal device and the next-hop terminal device in the downlink direction, and configure the RLC channel 4 according to the configuration information of the RLC channel 4. It should be noted that the embodiments of the present application do not limit the device for determining the downlink QoS information between the third terminal device and the next-hop terminal device in the downlink direction, and the device for determining the downlink configuration of the third terminal device and / or the configuration information of the RLC channel 4 based on the downlink QoS information between the third terminal device and the next-hop terminal device in the downlink direction. The device for executing these processes may be the third terminal device, or the next-hop terminal device in the downlink direction of the third terminal device, or other devices, and the present application does not make any limitation thereto.

[0445] Combined with Figure 14 , in some scenarios, the third terminal device is a terminal device that has established a unicast connection with the first terminal device and thus accessed the network device. In this scenario, when the second terminal device needs to access the network device, it can access the network device by discovering the third terminal device. After establishing a unicast connection between the second terminal device and the third terminal device, the second terminal device also establishes a unicast connection with the first terminal device.

[0446] At this time, since the second terminal device has established unicast connections with the first terminal device and the third terminal device and accessed the network device, and the third terminal device has also established a unicast connection with the first terminal device and accessed the network device, and the first terminal device is a terminal device directly connected to the network device, therefore, after the second terminal device accesses the network device, the network device can obtain the parameters of each hop node between the network device and the second terminal device (including but not limited to one or more of the relay hop count or relay identifier). The network device may directly allocate QoS information, configure the relay RLC link, and perform one or more of the SRAP configurations for each hop node according to the parameters of each hop node. The present application does not make any limitation thereto.

[0447] In a possible implementation manner, the data forwarded in the above data forwarding process may be signaling-related signaling data, such as SRB0 messages, SRB1 messages, SRB2 messages; or service-related service data, such as DRB messages. The following will be described in detail in combination with the initial access process and the RRC configuration process between the second terminal device and the network device.

[0448] As Figure 28 shown, the initial access and RRC configuration process between the first terminal device, the second terminal device, the third terminal device, and the network device can be specifically implemented through the following steps:

[0449] Step 2801: Establish a relay link between the second terminal device, the third terminal device, and the first terminal device.

[0450] In a possible implementation, there may be multiple third terminal devices between the first terminal device and the second terminal device. At this time, the actions performed by each third terminal device can refer to the actions performed by the third terminal device in the above process, and this application will not elaborate on this.

[0451] Step 2802: Configure the configuration information for transmitting SRB0 messages (hereinafter referred to as SRB0 message transmission configuration) between the second terminal device, the third terminal device, and the first terminal device. The SRB0 message includes an RRC connection establishment request message and an RRC connection establishment message.

[0452] Among them, the SRB0 message transmission configuration includes: the configuration of the local identifier (local ID). In addition, the SRB0 message transmission configuration may further include: the configuration of the PC5 relay RLC channel, and the PC5 SRAP configuration. Among them, the PC5 SRAP configuration includes the configuration of the mapping relationship between SRB0 and the PC5 relay RLC channel.

[0453] Regarding the configuration of the local identifier: The third terminal device assigns a first local identifier 1 to the second terminal device according to the layer 2 identifier of the second terminal device; the third terminal device assigns a first local identifier 2 to the first terminal device according to the layer 2 identifier of the first terminal device. When the third terminal device assigns local identifiers to the second terminal device and the first terminal device, it can be assigned by one third terminal device, or negotiated and assigned by all the third terminal devices between the second terminal device and the first terminal device. This application does not make a limitation on this.

[0454] Regarding the configuration of the PC5 relay RLC channel and the PC5 SRAP configuration, there may be the following possible methods.

[0455] In a possible manner, a dedicated or default-configured PC5 RLC channel is applied to transmit SRB0 messages. For example, the dedicated or default-configured PC5 RLC channel corresponds to a specific logical channel (with a logical channel identifier of x). In this manner, when the second terminal device receives an SRB0 message from the upper layer, it will be directly delivered to the dedicated or default PC5 RLC channel. The third terminal device receives the SRB0 message from the dedicated or default PC5 RLC channel between it and the second terminal device, and delivers the SRB0 message through the dedicated or default PC5 RLC channel between it and the first terminal device.

[0456] In another possible manner, a configured PC5 RLC channel is applied to transmit SRB0 messages. Among them, the PC5 RLC channel can be configured by the network or the terminal device itself. For example, the PC5 RLC channel is configured based on system messages or pre-configured information.

[0457] For the latter case, the second terminal device or the third terminal device also needs to determine the mapping relationship between the SRB0 message and the PC5 RLC channel. This mapping relationship includes, for example: the mapping relationship between the SRB0 message of the second terminal device and the PC5 relay RLC channel between the second terminal device and the third terminal device 1; the third terminal device 1 is the third terminal device connected to the second terminal device. The PC5 SRAP configuration of the third terminal device can include, for example: the mapping relationship between the SRB0 message of the second terminal device and the upstream PC5 relay RLC channel of the third terminal device, and the mapping relationship between the SRB0 message of the second terminal device and the downstream PC5 relay RLC channel of the third terminal device; the upstream of the third terminal device can be between two third terminal devices or between the third terminal device and the second terminal device; the downstream of the third terminal device can be between two relay devices or between the third terminal device and the first terminal device. The PC5 SRAP configuration of the first terminal device includes, for example: the mapping relationship between the SRB0 message of the second terminal device and the PC5 relay RLC channel between the first terminal device and the third terminal device 2; the third terminal device 2 is the third terminal device connected to the first terminal device.

[0458] It should be noted that the second terminal device, the third terminal device, and the first terminal device are all configured with the relevant configurations of the SRB0 message, and the relevant configurations of the SRB0 message can be understood in combination with the above uplink and downlink transmission configurations of the second terminal device, the third terminal device, and the first terminal device.

[0459] Optionally, the layer 2 identifier used by the second terminal device and the first terminal device in the discovery process and the unicast establishment process is the layer 2 identifier specifically allocated by the upper layer for the multi-hop U2N relay scenario. The second terminal device or the first terminal device may perform the discovery process and the connection establishment process described in the embodiments of the present application based on this layer 2 identifier.

[0460] Step 2803: The second terminal device sends an uplink SRB0 message.

[0461] Optionally, the SRB0 message in the embodiments of the present application may be, for example, an RRC establishment request message sent by the second terminal device.

[0462] Optionally, the second terminal device sends an uplink SRB0 message based on the PC5 relay RLC channel in step 2802 above. Specifically, the second terminal device generates a first data packet, which includes the uplink SRB0 message, the above-mentioned first local identifier 1, the first local identifier 2, and the identifier of SRB0. This first data packet is a PC5 SRAP PDU generated by the SRAP protocol layer of the second terminal device, and the above-mentioned first local identifier 1, the first local identifier 2, and the identifier of SRB0 are located in the header of the PC5 SRAP PDU. In a possible implementation, if the application-specific PC5 relay RLC channel is used to carry the SRB0 message, the SRB0 identifier may not need to be carried in the header.

[0463] It should be noted that the identification information of the above uplink SRB 0 message may be index 0, and index 0 is an index occupying 5 bits; or the identification information of the SRB 0 message is an index allocated for the second terminal device, and the present application does not make any limitations in this regard.

[0464] Step 2804: The first terminal device sends a SUI message (SidelinkUEInformationNRmessage) to the network device.

[0465] Among them, the SUI message is used to request the network device to allocate a second local identifier for the second terminal device.

[0466] Optionally, the SUI message includes the layer 2 identifier of the second terminal device. Based on this, after receiving the layer 2 identifier of the second terminal device, the network device allocates a second local identifier for the second terminal device according to the layer 2 identifier of the second terminal device.

[0467] Step 2805: The network device configures Uu configuration for the first terminal device to transmit the uplink SRB 0 message.

[0468] Among them, the Uu configuration for transmitting the uplink SRB 0 message includes one or more of the following: the Uu relay RLC channel, the second local identifier of the second terminal device, or the mapping relationship between the uplink SRB 0 and the Uu relay RLC channel.

[0469] Step 2806: The first terminal device sends an uplink SRB 0 message to the network device.

[0470] In a possible way, the first terminal device receives the uplink SRB 0 message of the second terminal device from the third terminal device and generates a second data packet, which includes the SRB 0 message, the second local identifier, and the identifier of the uplink SRB 0 message.

[0471] In a specific implementation, the first terminal device receives a first data packet from the third terminal device, including the first local identifier 1, the first local identifier 2, and the identifier of SRB 0. Further, the first terminal device can determine the SRB 0 message based on the first data packet. Taking the first data packet as a PC5 SRAP PDU as an example, after the first terminal device receives the first data packet, it removes the header of the PC5 SRAP PDU and generates the header of the Uu SRAP PDU according to the pre-determined configuration information. The header of the Uu SRAP PDU includes the second local identifier and the identifier of the uplink SRB 0 message. The first terminal device delivers the Uu SRAP PDU to the Uu relay RLC channel with the mapping relationship according to the mapping relationship between the uplink SRB 0 message and the Uu relay RLC channel, and sends the uplink SRB 0 message to the network device through the Uu relay RLC channel.

[0472] It can be understood that the SRAP header of the PC5 SRAP PDU includes the first local identifier 1, the first local identifier 2, and the identifier of the uplink SRB 0 message.

[0473] Step 2807: The network device sends a downlink SRB 0 message.

[0474] Among them, the downlink SRB 0 message can be, for example, an RRC connection establishment message.

[0475] In a specific implementation, the network device sends a third data packet to the first terminal device, which includes the downlink SRB 0 message, as well as the second local identifier and the identifier of SRB 0. The first terminal device generates a fourth data packet, which includes the downlink SRB 0 message, the first local identifier 1, the first local identifier 2, and the identifier of the downlink SRB 0 message. The first terminal device delivers the fourth data packet to the PC5 relay RLC channel corresponding to the SRB 0 message. The third data packet can be, for example, a Uu SRAP PDU, and the fourth data packet can be, for example, a PC5 SRAP PDU.

[0476] The first terminal device receives a third data packet from the network device and determines an SRB0 message based on the third data packet. Taking the third data packet as a Uu SRAP PDU as an example, after the first terminal device receives the third data packet, it removes the header of the Uu SRAP PDU and generates a header of a PC5 SRAP PDU according to pre-determined configuration information. The header of the PC5 SRAP PDU includes a first local identifier 1 and a first local identifier 2, and an identifier of the downlink SRB0 message. The first terminal device delivers the PC5 SRAP PDU to the PC5 relay RLC channel with the mapping relationship according to the mapping relationship between the downlink SRB0 message and the PC5 relay RLC channel, and sends the downlink SRB0 message to the third terminal device through the PC5 relay RLC channel.

[0477] In a possible implementation, the downlink SRB0 message further includes QoS information between the network device and the first terminal device. Specifically, the network device determines the QoS information of SRB1; the QoS information includes the QoS information between the network device and the first terminal device, and the QoS information between the first terminal device and the second terminal device. The network device carries the QoS information between the first terminal device and the second terminal device in the above RRC establishment message and sends it to the second terminal device, so that the second terminal device configures SRBI according to the QoS information between the first terminal device and the second terminal device. In addition, the network device may also configure the SRB1-related configuration between the network device and the first terminal device according to the QoS information between the network device and the first terminal device.

[0478] Step 2808, configure the configuration information of the SRB1 message among the second terminal device, the first terminal device, the third terminal device, and the network device.

[0479] In a possible implementation, after the second terminal device receives the RRC message, it obtains the uplink QoS information between the first terminal device and the second terminal device carried in the RRC message. The second terminal device or the third terminal device may divide the uplink QoS information of each hop between the first terminal device and the second terminal device based on the uplink QoS information between the first terminal device and the second terminal device. Each device of each hop configures the PC5 relay RLC channel and the adaptation layer configuration for uplink transmission of SRB1 based on the uplink QoS information of that hop.

[0480] For example, in the case where the second terminal device divides the uplink QoS information, the second terminal device may divide the uplink QoS information for each hop based on the uplink QoS information between the first terminal device and the second terminal device, and the information of each hop between the first terminal device and the second terminal device.

[0481] Or, for example, in the case where the third terminal device performs uplink QoS information division, any third terminal device may divide the uplink QoS information for each hop based on the uplink QoS information between the first terminal device and the second terminal device, as well as the information for each hop between the first terminal device and the second terminal device. It is also possible for the third terminal device for each hop to separately perform the uplink QoS information division for the corresponding hop. For example, after the second terminal device obtains the uplink QoS information between the first terminal device and the second terminal device, it sends it to the third terminal device a connected to the second terminal device, and the third terminal device a divides the uplink QoS information for the number of hops between the third terminal device a and the second terminal device. After that, the third terminal device a sends the remaining uplink QoS information to the next-hop third terminal device b, and the third terminal device b continues to divide the uplink QoS information between the third terminal device a and the third terminal device b, and so on until the uplink QoS information division is completed. It should be noted that the last-hop third terminal device may divide the uplink QoS information for two hops, namely the uplink QoS information between it and the previous-hop third terminal device, and the uplink QoS information between it and the first terminal device. Or the third terminal device a may also divide the uplink QoS information for two hops, namely the uplink QoS information between it and the second terminal device, and the uplink QoS information between it and the third terminal device b. At this time, the third terminal device b is responsible for dividing the uplink QoS information between the third terminal device b and the next hop of the third terminal device b. This application will not elaborate on this.

[0482] It should be noted that the network device may also configure the Uu relay RLC channel for transmitting SRB1 between the network device and the first terminal device according to the QoS information between the network device and the first terminal device, as well as the adaptation layer configuration. In addition, the network device may also send the QoS information between the first terminal device and the second terminal device to the first terminal device for the relevant configuration of the downlink SRB1 message. The specific configuration process may refer to the above process, and this application will not elaborate on this.

[0483] It should be noted that the second terminal device, the third terminal device, and the first terminal device are all configured with the relevant configuration of the SRB1 message. The relevant configuration of the SRB1 message may be understood in combination with the above uplink and downlink transmission configurations of the second terminal device, the third terminal device, and the first terminal device.

[0484] In another possible implementation, the first terminal device receives the downlink QoS information between the first terminal device and the second terminal device sent by the network. The first terminal device and the third terminal device may divide the downlink QoS information of each hop between the first terminal device and the second terminal device based on the downlink QoS information between the first terminal device and the second terminal device. Each device of each hop determines the PC5 relay RLC channel and the adaptation layer configuration for downlink transmission of SRB1 based on the downlink QoS information of that hop.

[0485] When the first terminal device divides the downlink QoS information, the first terminal device may divide the downlink QoS information for each hop based on the downlink QoS information between the first terminal device and the second terminal device, and the information of each hop between the first terminal device and the second terminal device.

[0486] When the third terminal device divides the downlink QoS information, any third terminal device may divide the downlink QoS information for each hop based on the downlink QoS information between the first terminal device and the second terminal device, and the information of each hop between the first terminal device and the second terminal device. Or each third terminal device of each hop may separately divide the downlink QoS information of the corresponding hop. For example, after the first terminal device obtains the downlink QoS information between the first terminal device and the second terminal device, it sends it to the third terminal device c connected to the first terminal device, and the third terminal device c divides the downlink QoS information of the number of hops between the third terminal device c and the first terminal device. After that, the third terminal device c sends the remaining downlink QoS information to the next-hop third terminal device d, and the third terminal device d continues to divide the downlink QoS information between the third terminal device d and the third terminal device c, and so on until the downlink QoS information division is completed. It should be noted that the last-hop third terminal device may divide the downlink QoS information of two hops, namely the downlink QoS information between it and the previous-hop third terminal device, and the downlink QoS information between it and the second terminal device. Or the third terminal device a may also divide the downlink QoS information of two hops, namely the downlink QoS information between it and the first terminal device, and the downlink QoS information between it and the third terminal device b. At this time, the third terminal device b is responsible for dividing the downlink QoS information between the third terminal device b and the next hop of the third terminal device b. This application will not elaborate on this.

[0487] Step 2809: The second terminal device sends an RRC connection setup complete message.

[0488] Step 2810: The network device sends a first RRC reconfiguration message to the first terminal device.

[0489] Among them, the first RRC reconfiguration message is used to configure the Uu relay RLC channel, the mapping relationship between SRB2 and the Uu relay RLC channel, and the mapping relationship between the DRB and the Uu relay RLC channel.

[0490] Optionally, the first RRC reconfiguration message includes QoS information of SRB2 and the DRB in the downlink direction, so that the first terminal device, the second terminal device, and the third terminal device complete the PC5 relay RLC channel configuration and the PC5 SRAP configuration during the downlink transmission of SRB2 and the DRB. The specific configuration process can refer to step 2807 or step 2808 above, which will not be elaborated here.

[0491] An example, the QoS information of SRB2 and the DRB in the downlink direction is the QoS information of SRB2 and the DRB in the downlink direction between the first terminal device and the second terminal device.

[0492] Step 2811: The network device sends a second RRC reconfiguration message to the second terminal device.

[0493] Among them, the second RRC reconfiguration message is used to configure SRB2 and the DRB.

[0494] Optionally, the second RRC reconfiguration message further includes QoS information of SRB2 and the DRB in the uplink direction, so that the first terminal device, the second terminal device, and the third terminal device complete the PC5 relay RLC channel configuration and the PC5 SRAP configuration during the uplink transmission of SRB2 and the DRB. The specific configuration process can refer to step 2807 or step 2808 above, which will not be elaborated here.

[0495] An example, the QoS information of SRB2 and the DRB in the uplink direction is the QoS information of SRB2 and the DRB in the uplink direction between the first terminal device and the second terminal device.

[0496] It should be noted that the QoS information in the embodiments of the present application can also be understood as QoS parameters, which are used to indicate the QoS parameter requirements that a radio bearer should meet during transmission between devices (such as between the second terminal device, the third terminal device, the first terminal device, or the network device). Based on the QoS information, the corresponding device can configure the configuration of the channel for transmitting the signaling or data corresponding to the QoS information and the SRAP configuration. The present application will not elaborate on this.

[0497] Step 2812: The second terminal device, the third terminal device, and the first terminal device configure the configuration information of SRB2 and the DRB according to the first RRC reconfiguration message and the second RRC reconfiguration message.

[0498] Optionally, the configuration information of SRB2 and DRB includes one or more of the following: PC5 relay RLC channel, or PC5 SRAP.

[0499] It should be noted that the second terminal device, the third terminal device, and the first terminal device are all configured with the relevant configurations of the above SRB2 and DRB messages. The relevant configurations of the SRB2 and DRB messages can be understood in combination with the above uplink and downlink transmission configurations of the second terminal device, the third terminal device, and the first terminal device.

[0500] It should be noted that the above Figure 25 or Figure 28 The configuration process in can be applied to the discovery process, the unicast connection establishment process, and / or the data forwarding process provided in the embodiments of the present application above, and can also be applied to other processes. The embodiments of the present application do not limit this.

[0501] It should be noted that the first identifier and the second identifier in the embodiments of the present application are both used to identify the radio bearer of the data packet. The first identifier and the second identifier can be the same identifier, that is, the same identifier is used in the uplink and downlink configurations of the terminal device to identify the radio bearer of the data packet. Or the first identifier and the second identifier can be different identifiers, that is, different identifiers are used in the uplink and downlink configurations of the terminal device to identify the radio bearer of the data packet.

[0502] It can be understood that when executing the communication method described in the embodiments of the present application, all the process steps in the above embodiments can be executed, or some of the process steps in the above embodiments can be executed. The embodiments of the present application do not limit this.

[0503] It should be noted that the identifier of the terminal device in the embodiments of the present application can be, for example, the user information identifier (user Info ID) of the relay device. Through this user Info ID, the capabilities of the relay device can be identified, such as whether the relay device supports U2U relay, whether it supports U2N relay, etc. The present application does not limit this. In other words, the identifier of the first terminal device in the embodiments of the present application can be understood as the user information identifier of the first terminal device, the identifier of the second terminal device can be understood as the user information identifier of the second terminal device, the identifier of the third terminal device can be understood as the user information identifier of the third terminal device, and the identifier of the fourth terminal device can be understood as the user information identifier of the fourth terminal device.

[0504] The above mainly introduced the solution provided by the embodiments of the present application from the perspective of interactions between network elements. Correspondingly, the embodiments of the present application also provide a communication device, which is used to implement the above various methods. The communication device may be the first terminal device in the above method embodiments, or a device including the above first terminal device, or a component applicable to the first terminal device; or, the communication device may be the second terminal device in the above method embodiments, or a device including the above second terminal device, or a component applicable to the second terminal device; or, the communication device may be the third terminal device in the above method embodiments, or a device including the above third terminal device, or a component applicable to the third terminal device; or, the communication device may be the network device in the above method embodiments, or a device including the above network device, or a component applicable to the network device. It can be understood that in order to implement the above functions, the communication device includes corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should easily realize that, combining the units and algorithm steps of the examples described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the way of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0505] The embodiments of the present application can perform functional module division on the communication device according to the above method embodiments. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. It should be understood that the division of modules in the embodiments of the present application is illustrative, only a logical function division, and there may be other division methods in actual implementation.

[0506] For example, Figure 29 FIG. 2900 is a schematic diagram of a communication device 2900 provided by an embodiment of the present application. The communication device includes a transceiver module 2910. Optionally, it includes a processing module 2920. The transceiver module 2910, also referred to as a transceiver unit, is used to implement the transceiver function. For example, it can be a transceiver circuit, a transceiver, a transceiver, or a communication interface.

[0507] Taking the communication device 2900 as the first terminal device described in the above method embodiments as an example, in one possible implementation:

[0508] A transceiver module 2910 is configured to send a first message, where the first message is used to indicate: supporting providing a relay service between a second terminal device and a network device, and relaying between the first terminal device and the second terminal device through at least one third terminal device. The transceiver module 2910 is further configured to receive a second message, where the second message is used to indicate establishing a unicast connection between the second terminal device and the first terminal device; wherein, the unicast connection is established through at least one third terminal device.

[0509] Taking the communication device 2900 as the second terminal device or the third terminal device described in the above method embodiment as an example, in a possible implementation:

[0510] A transceiver module 2910 is configured to receive a fourth message, where the fourth message is used to indicate: supporting providing a relay service between a second terminal device and a network device, and relaying between the first terminal device and the second terminal device through at least one third terminal device. The transceiver module 2910 is further configured to send a fifth message, where the fifth message is used to indicate establishing a unicast connection between the second terminal device and the first terminal device; wherein, the unicast connection is established through at least one third terminal device.

[0511] Taking the communication device 2900 as the third terminal device described in the above method embodiment as an example, in a possible implementation:

[0512] The transceiver module 2910 is further configured to send a fourth message, where the fourth message is used to indicate: supporting providing a relay service between a second terminal device and a network device, and relaying between the first terminal device and the second terminal device through at least one third terminal device. The transceiver module 2910 is further configured to receive a fifth message, where the fifth message is used to indicate establishing a unicast connection between the second terminal device and the first terminal device; wherein, the unicast connection is established through at least one third terminal device.

[0513] Taking the communication device 2900 as the network device described in the above method embodiment as an example, in a possible implementation:

[0514] A processing module 2920 is configured to obtain QoS information between a first terminal device and a second terminal device. The transceiver module 2910 is configured to send the QoS information between the first terminal device and the second terminal device.

[0515] Taking the communication device 2900 as the first terminal device described in the above method embodiment as an example, in another possible implementation:

[0516] A processing module 2920 is configured to determine a first configuration, where the first configuration includes a second local identifier, and the first configuration is used to send a second data packet. The second data packet includes one or more of the following: first data, or the second local identifier. The second local identifier is used to identify a second terminal device between a first terminal device and a network device. The first terminal device and the second terminal device are relayed through at least one third terminal device. A transceiver module 2910 is configured to send the second data packet according to the first configuration.

[0517] Taking the communication device 2900 as the first terminal device described in the above method embodiment as an example, in another possible implementation:

[0518] A processing module 2920 is configured to determine a second configuration, where the second configuration includes a first local identifier, and the second configuration is used to send a fourth data packet. The fourth data packet includes one or more of the following: second data, or the first local identifier. The first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device. The first terminal device and the second terminal device are relayed through at least one third terminal device. A transceiver module 2910 is configured to send the fourth data packet according to the second configuration.

[0519] Taking the communication device 2900 as the second terminal device or the third terminal device described in the above method embodiment as an example, in another possible implementation:

[0520] A processing module 2920 is configured to determine a third configuration, where the third configuration includes a first local identifier, and the third configuration is used to send a first data packet. The first data packet includes one or more of the following: first data, or the first local identifier. The first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device. The first terminal device and the second terminal device are relayed through at least one third terminal device. A transceiver module 2910 is configured to send the first data packet according to the third configuration.

[0521] Taking the communication device 2900 as the second terminal device or the third terminal device described in the above method embodiment as an example, in another possible implementation:

[0522] A processing module 2920 is configured to determine a fourth configuration, where the fourth configuration includes a first local identifier, and the fourth configuration is used to send a fourth data packet. The fourth data packet includes one or more of the following: first data, or the first local identifier. Wherein, the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device. The first terminal device and the second terminal device are relayed through at least one third terminal device. A transceiver module 2910 is configured to send the fourth data packet according to the fourth configuration.

[0523] Among them, all relevant contents of each step involved in the above method embodiments can be cited in the function descriptions of the corresponding functional modules, and will not be elaborated here. Optionally, the communication device 2900 may further include a storage module 2930, and the storage module 2930 may be used to store instructions and / or data, and the processing module 2920 may read the instructions and / or data in the storage module 2930.

[0524] In the embodiments of the present application, the communication device 2900 is presented in the form of dividing each functional module in an integrated manner. Here, the "module" may refer to a specific ASIC, circuit, a processor and a memory that execute one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions. In a simple embodiment, those skilled in the art can think that the communication device may adopt Figure 15 the form of the communication device 1700 shown.

[0525] For example, Figure 15 the processor 117 in the communication device 1700 shown may call the computer-executable instructions stored in the memory 112, so that the communication device 1700 executes the communication method in the above method embodiments.

[0526] Specifically, Figure 29 the functions / implementation processes of the transceiver module 2910 and the processing module 2920 in Figure 15 can be implemented by the processor 117 in the communication device 1700 shown calling the computer-executable instructions stored in the memory 112. Or, Figure 29 the function / implementation process of the processing module 2920 in Figure 15 can be implemented by the processor 117 in the communication device 1700 shown calling the computer-executable instructions stored in the memory 112, Figure 29 the function / implementation process of the transceiver module 2910 in Figure 15 can be implemented by the transceiver 115 in the communication device 1700 shown.

[0527] Since the communication device provided by the embodiments of the present application can execute the above communication method, the technical effects that can be obtained thereby can refer to the above method embodiments, and will not be elaborated here.

[0528] It should be understood that one or more of the above modules or units can be implemented by software, hardware, or a combination of both. When any of the above modules or units is implemented by software, the software exists in the form of computer program instructions and is stored in the memory. The processor can be used to execute the program instructions and implement the above method flow. The processor can be built into the SoC (System on Chip) or ASIC, or it can be an independent semiconductor chip. In addition to the cores in the processor for executing software instructions for arithmetic or processing, it can further include necessary hardware accelerators, such as field programmable gate array (FPGA), PLD (Programmable Logic Device), or logic circuits for implementing dedicated logic operations.

[0529] When the above modules or units are implemented by hardware, the hardware can be any one or any combination of CPU, microprocessor, digital signal processing (DSP) chip, microcontroller unit (MCU), artificial intelligence processor, ASIC, SoC, FPGA, PLD, dedicated digital circuit, hardware accelerator, or non-integrated discrete device, which can run the necessary software or execute the above method flow without relying on software.

[0530] Optionally, an embodiment of the present application further provides a communication device (for example, the communication device can be a chip or a chip system). The communication device includes a processor for implementing the method in any of the above method embodiments. In a possible design, the communication device further includes a memory. The memory is used to store necessary program instructions and data. The processor can call the program code stored in the memory to instruct the communication device to execute the method in any of the above method embodiments. Of course, the memory may not be in the communication device. When the communication device is a chip system, it can be composed of chips or can include chips and other discrete devices. The embodiments of the present application do not make specific limitations on this.

[0531] Optionally, an embodiment of the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program or instructions. When it runs on the communication device, it enables the communication device to execute the method described in any of the above method embodiments or any of its implementation manners.

[0532] Optionally, an embodiment of the present application further provides a communication system. The communication system includes the network device described in the above method embodiment and the terminal device described in the above method embodiment.

[0533] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions according to the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from a website, a computer, a server, or a data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, a data center, etc. that contains one or more media integrated therein. The available medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD)), etc.

[0534] Although the present application has been described in conjunction with various embodiments herein, however, in the process of implementing the claimed present application, those skilled in the art can understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit can implement several functions recited in the claims. Certain measures are recited in mutually different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0535] Although the present application has been described in conjunction with specific features and their embodiments, it is obvious that various modifications and combinations can be made without departing from the scope of the present application. Accordingly, the present specification and the drawings are merely exemplary illustrations of the present application defined by the appended claims, and are considered to have covered any and all modifications, variations, combinations, or equivalents within the scope of the present application. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and modifications.

Claims

1. A communication method, characterized in that, Applied to a first terminal device, the method includes: Sending a first message, the first message being used to indicate: supporting providing a relay service between the second terminal device and a network device, and relaying between the first terminal device and the second terminal device through at least one third terminal device; Receiving a second message, the second message being used to indicate establishing a unicast connection between the second terminal device and the first terminal device; wherein, the unicast connection is established through the at least one third terminal device.

2. The method according to claim 1, wherein The first message being used to indicate includes: The first message includes first indication information and / or second indication information, the first indication information and / or second indication information being used to indicate: supporting providing the relay service for the second terminal device, and relaying between the first terminal device and the second terminal device through the at least one third terminal device.

3. The method according to claim 1 or 2, characterized in that, The second message includes one or more of the following: an identifier of the at least one third terminal device, or hop count information between the first terminal device and the second terminal device.

4. The method according to any one of claims 1 to 3, characterized in that, The second message includes: first indication information and / or second indication information, the first indication information and / or second indication information being used to indicate: supporting providing the relay service for the second terminal device, and relaying between the first terminal device and the second terminal device through the at least one third terminal device.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: Receiving a third message; the third message being used to request providing the relay service.

6. The method according to claim 5, characterized in that The third message includes one or more of the following: an identifier of the at least one third terminal device, or hop count information between the first terminal device and the second terminal device.

7. The method according to claim 5 or 6, characterized in that, The third message includes: third indication information and / or fourth indication information; the third indication information and / or fourth indication information being used to request providing the relay service, and relaying between the first terminal device and the second terminal device through the at least one third terminal device.

8. The method according to any one of claims 1-7, characterized in that, The method further includes: Receiving a first data packet; the first data packet includes one or more of the following: first data or a first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device; Sending a second data packet to the network device; the second data packet includes one or more of the following: the first data, or a second local identifier; the second local identifier is used to identify the second terminal device between the first terminal device and the network device.

9. The method according to claim 8, wherein The method further includes: Determining a first configuration, the first configuration including the second local identifier, the first configuration being used to send the second data packet.

10. The method according to claim 9, wherein The sending the second data packet to the network device: Based on a first RLC channel indicated in the first configuration, sending the second data packet to the network device, the first RLC channel being a channel associated with a radio bearer corresponding to the first data.

11. The method according to any one of claims 1-10, characterized in that, The method further includes: Receive a third data packet from the network device; the third data packet includes one or more of the following: second data, or a second local identifier; the second local identifier is used to identify the second terminal device between the first terminal device and the network device. Send a fourth data packet; the fourth data packet includes one or more of the following: the second data, or a first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

12. The method according to claim 14, characterized in that The method further includes: Determine a second configuration, the second configuration includes the first local identifier, and the second configuration is used to send the fourth data packet.

13. The method according to claim 12, wherein The sending of the fourth data packet includes: Based on a second RLC channel indicated in the second configuration, send the fourth data packet, and the second RLC channel is a channel associated with a radio bearer corresponding to the fourth data.

14. The method according to claim 12 or 13, characterized in that, The second configuration is a configuration determined based on downlink QoS information between the first terminal device and an adjacent terminal device.

15. The method according to any one of claims 12 - 14, characterized in that, The determining of the second configuration includes: Receive downlink QoS information between the first terminal device and the second terminal device; Determine the second configuration based on the downlink QoS information between the first terminal device and the second terminal device.

16. The method according to claim 15, characterized in that The determining the second configuration based on the downlink QoS information between the first terminal device and the second terminal device includes: Based on the downlink QoS information between the first terminal device and the second terminal device, determine the downlink QoS information between the first terminal device and the adjacent terminal device; Based on the downlink QoS information between the first terminal device and the adjacent terminal device, determine the second configuration.

17. A communication method, characterized in that, Applied to a first device, the first device includes a second terminal device or a third terminal device; the method includes: Receive a fourth message, the fourth message is used to indicate: support for providing relay services between the second terminal device and the network device, and the first terminal device and the second terminal device are relayed through at least one of the third terminal devices; Send a fifth message, the fifth message is used to indicate the establishment of a unicast connection between the second terminal device and the first terminal device; wherein, the unicast connection is established through at least one of the third terminal devices.

18. The method according to claim 17, wherein The fourth message is used to indicate, including: The fourth message includes first indication information and / or second indication information, and the first indication information and / or second indication information are used to indicate: support for providing the relay service for the second terminal device, and the first terminal device and the second terminal device are relayed through at least one of the third terminal devices.

19. The method according to claim 17 or 18, characterized in that The fifth message includes one or more of the following: an identifier of at least one of the third terminal devices, or hop count information between the first terminal device and the second terminal device.

20. The method according to any one of claims 17-19, characterized in that, The fifth message includes: first indication information and / or second indication information, where the first indication information and / or the second indication information is used to indicate: support for providing the relay service for the second terminal device, and relaying between the first terminal device and the second terminal device through the at least one third terminal device.

21. The method according to any one of claims 17-20, characterized in that, The method further includes: Sending a sixth message; the sixth message is used to request the provision of the relay service.

22. The method according to claim 21, wherein The sixth message includes: third indication information and / or fourth indication information; the third indication information and / or the fourth indication information is used to request the provision of the relay service, and relaying between the first terminal device and the second terminal device through the at least one third terminal device.

23. The method according to claim 21 or 22, characterized in that The method is applied to a fourth terminal device, and the sixth message includes one or more of the following: an identifier of the fourth terminal device, identifiers of one or more third terminal devices between the fourth terminal device and the second terminal device, or hop count information between the fourth terminal device and the second terminal device, where the fourth terminal device is one of the at least one third terminal device.

24. The method according to any one of claims 17 - 23, characterized in that, The method further includes: Sending a first data packet; the first data packet includes one or more of the following: first data, or a first local identifier; the first local identifier is used to identify the first terminal device and / or the second terminal device between the second terminal device and the first terminal device.

25. The method according to claim 24, wherein The method is applied to a fourth terminal device, and the fourth terminal device is one of the at least one third terminal device; the method further includes: Receiving the fifth data packet.

26. The method according to claim 24 or 25, characterized in that, The method further includes: Determining a third configuration, where the first configuration includes the first local identifier, and the third configuration is used to send the first data packet.

27. The method according to claim 26, wherein The sending of the first data packet includes: Sending the first data packet based on a third RLC channel indicated in the third configuration; the third RLC channel is a channel associated with a radio bearer corresponding to the first data.

28. A communication device, characterized in that, Includes: Functional units for performing the functions of the method according to any one of claims 1-27; wherein the actions performed by the functional units are implemented by hardware or by hardware executing corresponding software.

29. A communication device, characterized in that, Includes: A processor; The processor is connected to a memory, and the memory is used to store computer execution instructions. The processor executes the computer execution instructions stored in the memory so that the communication device implements the method according to any one of claims 1-27.

30. A computer-readable storage medium, characterized in that, Includes instructions that, when run on a computer, cause the computer to execute the method according to any one of claims 1-27.

31. A chip, characterized in that, The chip includes a processor; the processor is connected to a memory, and the memory is used to store computer execution instructions. The processor executes the computer execution instructions stored in the memory so that the communication device implements the method according to any one of claims 1-27.

32. A computer program product comprising instructions, characterized in that, When it runs on a communication device, it causes the communication device to implement the method according to any one of claims 1-27.

33. A communication system, characterized in that, The communication system includes a first terminal device as described in any one of claims 1-16 and a first device as described in any one of claims 17-27.

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