Communication method, communication device and communication system

Abstract

The invention provides a communication method, a communication device and a communication system, the communication method is applied to a first terminal device, and the first terminal device communicates with an access network device through a second terminal device. The communication method comprises the following steps: receiving a first message from a second terminal device, wherein the first message is used for indicating that a wireless link failure occurs between the second terminal device and an access network device; and stopping sending data to the second terminal equipment, wherein the data comprises data sent by the first terminal equipment to the access network equipment through the second terminal equipment. In this way, in the process of reestablishing the first terminal equipment and the access network equipment, the first terminal equipment clears away the cached uplink data. After the first terminal equipment and the access network equipment are reestablished, the access network equipment does not receive the data packet which is forwarded by the second terminal equipment and is encrypted by adopting the secret key before reestablishment, so that wrong data cannot be decrypted.

Description

Technical Field

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

[0002] User equipment (UE) to network relay (UE-to-Network Relay, U2N Relay) technology is a technology that uses relay terminal equipment (relay UE) to assist remote terminal equipment (remote UE) and access network equipment in communicating. The relay terminal equipment and the remote terminal equipment communicate through the sidelink (SL), and the relay terminal equipment and the access network equipment communicate through the air interface.

[0003] In the existing scheme, after the relay terminal device detects that the wireless link between the relay terminal device and the access network device fails, the remote terminal device and the relay terminal device need to re-establish the connection with the access network device respectively, and in the process of re-establishing the connection, the access network device will update the encryption key for the data packet. However, after the remote terminal device and the relay terminal device re-establish the connection with the access network device respectively, there is often a phenomenon that the access network device uses the re-established key to decrypt the wrong data. Summary of the invention

[0004] The present application provides a communication method, a communication device and a communication system. Through the communication method, after the first terminal device and the access network device are reestablished, the access network device will not receive the data packet encrypted by the original key, and thus no erroneous data will be decrypted.

[0005] In a first aspect, a communication method is provided, which can be executed by a first terminal device, or can also be executed by a chip or circuit for the first terminal device, and the present application does not limit this. For ease of description, the following is an example of execution by the first terminal device. The first terminal device communicates with the access network device through the second terminal device.

[0006] The communication method includes: receiving a first message from a second terminal device, the first message being used to indicate a wireless link failure between the second terminal device and an access network device; and stopping sending data to the second terminal device, the data including data sent by the first terminal device to the access network device via the second terminal device.

[0007] In the technical solution provided by the present application, when a wireless link failure occurs between the second terminal device and the access network device, the second terminal device sends a first message to the first terminal device, and after the first terminal device receives the first message, it stops sending uplink data to the second terminal device. In this way, during the reconstruction process between the first terminal device and the access network device, the first terminal device clears the cached uplink data. Furthermore, after the first terminal device and the access network device are reconstructed, the access network device will not receive the data packet forwarded by the second terminal device that is encrypted using the key before the reconstruction, so that the access network device will not decrypt erroneous data.

[0008] In a possible implementation, after stopping sending data to the second terminal device, the method further includes: sending a first request message to the second terminal device, where the first request message is used to request to re-establish a connection between the first terminal device and the access network device.

[0009] Before the first terminal device requests the access network device to reestablish through the second terminal device, the first terminal device stops sending data to the second terminal device. In this way, during the process of the first terminal device and the access network device being reestablished, the second terminal device will not receive the data packet encrypted by the first terminal device using the key before the reestablishment. Furthermore, after the first terminal device and the access network device are reestablished, the access network device will not receive the data packet forwarded by the second terminal device and encrypted using the key before the reestablishment, so that the access network device will not decrypt the wrong data.

[0010] In a possible implementation, when a first condition is met, the first entity is released. The first entity is used by the first terminal device to send a message to the second terminal device. The first condition includes that the first terminal device receives the first message or the first terminal device sends a first request message.

[0011] When the first terminal device receives the first message or sends the first request message, the first terminal device releases the first entity. In this way, the first terminal device clears the data packets encrypted with the key before re-establishment cached on the first terminal device side. Then, after the first terminal device and the access network device are re-established, the access network device will not receive the data packets forwarded by the second terminal device and encrypted with the key before re-establishment, so that the access network device will not decrypt erroneous data.

[0012] In a possible implementation, when a second condition is met, the first configuration is released. The first configuration is used for the first terminal device to receive a message from the second terminal device. The second condition includes the first terminal device receiving the first message or the first terminal device sending the first request message.

[0013] When the first terminal device receives the first message or sends the first request message, the first terminal device releases the first configuration. In this way, since the first terminal device does not have a corresponding configuration to receive the data packet forwarded by the second terminal device and encrypted with the key before re-establishment, the first terminal device will not receive the data packet forwarded by the second terminal device and encrypted with the key before re-establishment by the access network device. Furthermore, the first terminal device will not decrypt erroneous data.

[0014] In one possible implementation, the communication method further includes: receiving a second message from an access network device, the second message being used to indicate one or more added or modified wireless link control channel configurations; and releasing the wireless link control channel configuration between the first terminal device and the second terminal device.

[0015] When the access network device indicates that the first terminal device needs to add or modify the radio link control channel configuration, the first terminal device processes it according to the full configuration and releases all radio link control channel configurations between the first terminal device and the second terminal device. In this way, the first terminal device side clears the data packets encrypted with the key before the re-establishment cached on the first terminal device side. Then, the access network device will not receive the data packets of the first terminal device forwarded by the second terminal device and encrypted with the key before the re-establishment, so the access network device will not decrypt the wrong data.

[0016] In a second aspect, a communication method is provided, which can be executed by a second terminal device, or can also be executed by a chip or circuit for the second terminal device, which is not limited in this application. For ease of description, the following is an example of execution by the second terminal device. The second terminal device is used to provide a relay service for communication between the first terminal device and the access network device.

[0017] The communication method includes: sending a first message to a first terminal device, the first message is used to indicate that a wireless link failure occurs between a second terminal device and an access network device; stopping sending data to the first terminal device, the data including data sent by the access network device to the first terminal device via the second terminal device.

[0018] In the technical solution provided by the present application, when a wireless link failure occurs between the second terminal device and the access network device, the second terminal device sends a first message to the first terminal device, and the second terminal device stops sending downlink data to the first terminal device. In this way, during the process of the first terminal device and the access network device being reestablished, the second terminal device clears the cached downlink data. Furthermore, after the first terminal device and the access network device are reestablished, the first terminal device will not receive the data packet forwarded by the second terminal device that is encrypted using the key before the reestablishment, so that the first terminal device will not decrypt erroneous data.

[0019] In a possible implementation, after stopping sending data to the first terminal device, the communication method further includes: sending a second request message to the access network device, where the second request message is used to request to re-establish a connection between the second terminal device and the access network device.

[0020] Before the second terminal device requests the access network device to reestablish, the first terminal device stops sending data to the first terminal device. In this way, during the process of reestablishing the connection between the second terminal device and the access network device, the first terminal device will not receive the data packet forwarded by the second terminal device and encrypted with the key before reestablishment. Furthermore, after the second terminal device and the access network device are reestablished, the first terminal device will not receive the data packet forwarded by the second terminal device and encrypted with the key before reestablishment, so that the first terminal device will not decrypt erroneous data.

[0021] In a possible implementation, the communication method further includes: releasing the second entity when a third condition is met. The second entity is used by the second terminal device to send a message to the first terminal device; the third condition includes one of the following: the second terminal device detects that a wireless link failure occurs between the second terminal device and the access network device; the second terminal device sends a first message; the second terminal device sends a second request message.

[0022] When the second terminal device detects that the wireless link between the second terminal device and the access network device fails, or the second terminal device sends a first message, or the second terminal device sends a second request message, the second terminal device releases the second entity. In this way, the second terminal device side clears the data packets encrypted with the key before the re-establishment cached on the second terminal device side. Then, after the first terminal device and the access network device are reestablished, the first terminal device will not receive the data packets forwarded by the second terminal device that are encrypted with the key before the re-establishment, so the first terminal device will not decrypt erroneous data.

[0023] In a possible implementation, the communication method further includes: when a fourth condition is met, releasing the second configuration. The second configuration is used for the second terminal device to receive a message from the first terminal device. The fourth condition includes one of the following: the second terminal device detects that a wireless link failure occurs between the second terminal device and the access network device; the second terminal device sends a first message; the second terminal device sends a second request message.

[0024] When the second terminal device detects that the wireless link between the second terminal device and the access network device fails, or the second terminal device sends the first message, or the second terminal device sends the second request message, the second terminal device releases the second configuration. In this way, since the second terminal device does not have a corresponding configuration to receive the data packet encrypted by the first terminal device using the key before the re-establishment, the access network device will not receive the data packet forwarded by the second terminal device and encrypted by the first terminal device using the key before the re-establishment. Furthermore, the access network device will not decrypt erroneous data.

[0025] In one possible implementation, the communication method further includes: receiving a third message from an access network device, the third message being used to indicate one or more added or modified wireless link control channel configurations; and releasing the wireless link control channel between the first terminal device and the second terminal device.

[0026] When the access network device instructs the second terminal device to add or modify the radio link control channel configuration, the second terminal device processes it according to the full configuration and releases all radio link control channel configurations between the first terminal device and the second terminal device. In this way, the second terminal device side clears the data packets encrypted with the key before the re-establishment from the access device cached on the second terminal device side. Then, after the first terminal device and the access network device are reestablished, the first terminal device will not receive the data packets encrypted with the key before the re-establishment forwarded by the second terminal device, so the first terminal device will not decrypt the wrong data.

[0027] In a third aspect, a communication method is provided, which can be executed by a first terminal device, or can also be executed by a chip or circuit for the first terminal device, and the present application does not limit this. For ease of description, the following is an example of execution by the first terminal device. The first terminal device communicates with the access network device through the second terminal device.

[0028] The communication method includes: receiving a first response message from an access network device, the first response message is used to indicate a second identifier and a second key; receiving first information from a second terminal device, the first information includes first data and a first identifier, the first data is encrypted using a first key, the first identifier is an identifier of the first terminal device, and the first identifier is used for a sidelink relay adaptation layer; and processing the first data using the first key.

[0029] In the technical solution provided in the present application, the first terminal device processes the received first data according to the first identifier, so that the first terminal device can avoid decoding an erroneous data packet.

[0030] In a possible implementation manner, using the first key to process the first data includes: decrypting the first data or discarding the first data according to the first identifier.

[0031] In a possible implementation, decrypting the first data or discarding the first data according to the first identifier includes: determining that the first data is encrypted using a first key according to the first identifier; and decrypting the first data or discarding the first data.

[0032] The first identifier carried by the first information is used to distinguish whether the first data carried by the first information is encrypted using the first key or the second key. In this way, the first terminal device determines whether the first data is encrypted using the first key based on the first identifier in the first information, and then uses the first key to decrypt the first data or discard the first data. In this way, the first terminal device can avoid decrypting an erroneous data packet.

[0033] In a possible implementation, the communication method further includes: stopping sending data to the second terminal device, the data including data sent by the first terminal device to the access network device via the second terminal device.

[0034] The first terminal device processes the received first data according to the first identifier, and the first terminal device stops sending uplink data to the second terminal device. In this way, after the first terminal device and the access network device are reestablished, the access network device will not receive the data packet forwarded by the second terminal device and encrypted with the first key, so that the access network device will not decrypt erroneous data.

[0035] In a possible implementation, the communication method further includes: sending a fourth message to the access network device, the fourth message being used to indicate that the connection between the first terminal device and the access network device has been reestablished; and releasing the first identifier.

[0036] After the first terminal device and the access network device complete the re-establishment, the first terminal device releases the first identifier and stops maintaining the first identifier, thereby reducing the overhead of the first terminal device.

[0037] In a possible implementation manner, the releasing the first local identifier includes: if the second information carrying the first identifier is not received within a preset time, releasing the first identifier.

[0038] After the first terminal device completes the re-establishment with the access network device, if the second information carrying the first identifier is not received within a preset time, the first terminal device automatically releases the first identifier and automatically stops maintaining the first identifier, thereby reducing the overhead of the first terminal device.

[0039] In a fourth aspect, a communication method is provided, which may be executed by a first terminal device, or may be executed by a chip or circuit for the first terminal device, and the present application does not limit this. For ease of description, the following is an example of execution by the first terminal device. The first terminal device communicates with the access network device through the second terminal device.

[0040] The communication method includes: sending a first request message to a second terminal device, the first request message is used to request to re-establish a connection between the first terminal device and the access network device; rebuilding a third entity, the third entity is used for the first terminal device to send a message to the second terminal device; receiving first information from the second terminal device, the first information includes first data and a first identifier, the first data is encrypted using a first key, the first identifier is an identifier of the first terminal device, and the first identifier is used for a sidelink relay adaptation layer; and stopping processing the first data.

[0041] In the technical solution provided by the present application, after the first terminal device sends a request to the access network device through the second terminal device to re-establish the connection between the first terminal device and the access network device, the first terminal device re-establishes the third entity by itself. However, since the first terminal device has not re-established the configuration corresponding to the third entity or the first terminal device has not received the instruction from the access network device to establish the configuration corresponding to the third entity, after the first terminal device receives the first information, it stops processing the first data, which can prevent the first terminal device from decoding an erroneous data packet.

[0042] In a possible implementation, the first terminal device includes a third entity and a fourth entity, the fourth entity is a wireless link control entity, and stopping processing the first data includes: the fourth entity stops submitting the first data to the third entity, or the fourth entity discards the first data.

[0043] In a possible implementation, the communication method further includes: stopping sending data to the second terminal device, the data including data sent by the first terminal device to the access network device via the second terminal device.

[0044] Since the first terminal device has not re-established the configuration corresponding to the third entity or the first terminal device has not received the access network device's instruction to establish the configuration corresponding to the third entity, the first terminal device stops sending uplink data to the second terminal device. In this way, after the first terminal device and the access network device are re-established, the access network device will not receive the data packet forwarded by the second terminal device that is encrypted using the key before the re-establishment, so that the access network device will not decrypt erroneous data.

[0045] In a fifth aspect, a communication method is provided, which can be executed by a second terminal device, or can also be executed by a chip or circuit for the second terminal device, which is not limited in this application. For ease of description, the following is an example of execution by the second terminal device. The second terminal device is used to provide a relay service for communication between the first terminal device and the access network device.

[0046] The communication method includes: sending a second request message to the access network device, the second request message is used to request to re-establish the connection between the second terminal device and the access network device; rebuilding the fifth entity, the fifth entity is used for the second terminal device to forward the message transmitted between the first terminal device and the access network device; receiving third information from the first terminal device, the third information includes second data and a first identifier, the second data is encrypted with a first key, the first identifier is the identifier of the first terminal device, and the first identifier is used for the sidelink relay adaptation layer; and stopping processing the second data.

[0047] In the technical solution provided by the present application, after the second terminal device sends a request to the access network device to reestablish the connection between the second terminal device and the access network device, the second terminal device reestablishes the fifth entity by itself. However, since the second terminal device does not reestablish the configuration corresponding to the fifth entity or the second terminal device does not receive the access network device's instruction to establish the configuration corresponding to the fifth entity, the second terminal device stops processing the second data after receiving the third information. Furthermore, after the second terminal device and the access network device are reestablished, the access network device will not receive the data packet encrypted with the first key forwarded by the second terminal device, so that the access network device will not decrypt erroneous data.

[0048] In a possible implementation, the second terminal device includes a fifth entity and a sixth entity, the sixth entity is a wireless link control entity, and stopping processing the second data includes: the sixth entity stops submitting the second data to the fifth entity, or the sixth entity discards the second data.

[0049] In a possible implementation, the communication method further includes: stopping sending data to the first terminal device, the data including data sent by the access network device to the first terminal device via the second terminal device.

[0050] In a sixth aspect, a communication method is provided, which can be executed by an access network device, or can also be executed by a chip or circuit for an access network device, which is not limited in this application. For ease of description, the following description is taken as an example of execution by an access network device.

[0051] The communication method includes: sending a sixth message to a second terminal device, the sixth message is used to indicate a second identifier and a second key; receiving third information from the second terminal device, the third information includes second data and a first identifier, the second data is encrypted using a first key, and the second terminal device is used to provide a relay service for the communication between the first terminal device and the access network device; and processing the second data using the first key. The first identifier and the second identifier are identifiers of the first terminal device, and the first identifier and the second identifier are used for the sidelink relay adaptation layer.

[0052] In the technical solution provided in the present application, the access network device processes the received second data according to the first identifier, so that the access network device can avoid decoding an erroneous data packet.

[0053] In a possible implementation manner, using the first key to process the second data includes: decrypting the second data or discarding the second data according to the first identifier.

[0054] In a possible implementation, decrypting the second data or discarding the second data according to the first identifier includes: determining that the second data is encrypted using the first key according to the first identifier; and decrypting the second data or discarding the second data.

[0055] The first identifier carried by the third information is used to distinguish whether the second data carried by the third information is encrypted using the first key or the second key. In this way, the access network device determines whether the second data is encrypted using the first key based on the first identifier in the third information, and then uses the first key to decrypt the second data or discard the second data. In this way, the access network device can avoid decrypting erroneous data packets.

[0056] In a seventh aspect, a communication method is provided, which can be executed by a second terminal device, or can also be executed by a chip or circuit for the second terminal device, which is not limited in this application. For ease of description, the following is an example of execution by the second terminal device. The second terminal device is used to provide a relay service for communication between the first terminal device and the access network device.

[0057] The communication method includes: initiating reestablishment between the second terminal device and the access network device; releasing the first entity and the second entity; applying the first predefined configuration to the third entity; and applying the second predefined configuration to the fourth entity. The first entity and the third entity are used for the second terminal device to receive a first request message from the first terminal device, and the second entity and the fourth entity are used for the second terminal device to receive a fourth message from the first terminal device, the first request message is used to request to reestablish the connection between the first terminal device and the access network device, and the fourth message is used to indicate that the connection between the first terminal device and the access network device has been reestablished.

[0058] After the second terminal device initiates the re-establishment process between the second terminal device and the access network device, the second terminal device releases the entity corresponding to the first predefined configuration and the second predefined configuration of the second terminal device, and re-establishes the entity corresponding to the first predefined configuration and the second predefined configuration. In this way, the first terminal device sends the first request message and the fourth message to the access network device through the second terminal device, and the sequence numbers of the entities of the first terminal device and the second terminal device both start from 0. Therefore, the second terminal device can correctly receive the first request message and the fourth message, and then forward them to the access network device, ensuring that the re-establishment process of the first terminal device proceeds normally.

[0059] In an eighth aspect, a communication device is provided, which may be a first terminal device, or a chip or circuit of the first terminal device, which is not limited in the present application.

[0060] The communication device includes: a transceiver unit, used to receive a first message from a second terminal device, the first message is used to indicate a wireless link failure between the second terminal device and the access network device; a processing unit, used to stop sending data to the second terminal device, the data including data sent by the first terminal device to the access network device via the second terminal device.

[0061] In a possible implementation, the transceiver unit is further used to send a first request message to the second terminal device, where the first request message is used to request to re-establish a connection between the first terminal device and the access network device.

[0062] In a possible implementation, the processing unit is further used to: release the first entity when a first condition is met. The first entity is used by the first terminal device to send a message to the second terminal device. The first condition includes that the first terminal device receives the first message or the first terminal device sends a first request message.

[0063] In a possible implementation, the processing unit is further used to: release the first configuration when a second condition is met. The first configuration is used for the first terminal device to receive a message from the second terminal device. The second condition includes the first terminal device receiving the first message or the first terminal device sending the first request message.

[0064] In one possible implementation, the transceiver unit is also used to receive a second message from the access network device, where the second message is used to indicate one or more added or modified wireless link control channel configurations; the processing unit is also used to release the wireless link control channel configuration between the first terminal device and the second terminal device.

[0065] The technical effects of any possible implementation method in the eighth aspect can refer to the technical effects of the corresponding implementation method of the first aspect, and will not be repeated here.

[0066] In a ninth aspect, a communication device is provided, which may be a second terminal device, or a chip or circuit of the second terminal device, and this application does not limit this.

[0067] The communication device includes: a transceiver unit, used to send a first message to a first terminal device, the first message is used to indicate that a wireless link failure occurs between a second terminal device and an access network device; a processing unit, used to stop sending data to the first terminal device, the data including data sent by the access network device to the first terminal device via the second terminal device.

[0068] In a possible implementation, the transceiver unit is further used to send a second request message to the access network device, where the second request message is used to request to re-establish a connection between the second terminal device and the access network device.

[0069] In a possible implementation, the processing unit is further used to: release the second entity when a third condition is met. The second entity is used for the second terminal device to send a message to the first terminal device; the third condition includes one of the following: the second terminal device detects that a wireless link failure occurs between the second terminal device and the access network device; the second terminal device sends a first message; the second terminal device sends a second request message.

[0070] In a possible implementation, the processing unit is further used to: release the second configuration when a fourth condition is met. The second configuration is used for the second terminal device to receive a message from the first terminal device. The fourth condition includes one of the following: the second terminal device detects that a wireless link failure occurs between the second terminal device and the access network device; the second terminal device sends a first message; the second terminal device sends a second request message.

[0071] In one possible implementation, the transceiver unit is also used to receive a third message from the access network device, where the third message is used to indicate one or more added or modified wireless link control channel configurations; the processing unit is also used to release the wireless link control channel configuration between the first terminal device and the second terminal device.

[0072] The technical effects of any possible implementation method in the ninth aspect can refer to the technical effects of the corresponding implementation method of the second aspect, and will not be repeated here.

[0073] In the tenth aspect, a communication device is provided, which may be a first terminal device, or a chip or circuit of the first terminal device, which is not limited in the present application.

[0074] The communication device includes: a transceiver unit, used to receive first information from a second terminal device, the first information includes first data and a first identifier, the first data is encrypted using a first key, the first identifier is an identifier of the first terminal device, and the first identifier is used for a sidelink relay adaptation layer; the transceiver unit is also used to receive a first response message from an access network device, the first response message is used to indicate a second identifier and a second key; a processing unit is used to process the first data using the first key.

[0075] In a possible implementation manner, using the first key to process the first data includes: decrypting the first data or discarding the first data according to the first identifier.

[0076] In a possible implementation, the processing unit is further configured to determine, based on the first identifier, that the first data is encrypted using the first key; and to decrypt the first data or discard the first data.

[0077] In a possible implementation, the transceiver unit is further used to stop sending data to the second terminal device, where the data includes data sent by the first terminal device to the access network device via the second terminal device.

[0078] In a possible implementation, the transceiver unit is further used to send a fourth message to the access network device, where the fourth message is used to indicate that the connection between the first terminal device and the access network device has been reestablished; and the processing unit is further used to release the first identifier.

[0079] In a possible implementation manner, the processing unit is further specifically configured to release the first identifier if the second information carrying the first identifier is not received within a preset time.

[0080] After the first terminal device completes the re-establishment with the access network device, if the second information carrying the first identifier is not received within a preset time, the first terminal device automatically releases the first identifier and automatically stops maintaining the first identifier, thereby reducing the overhead of the first terminal device.

[0081] The technical effects of any possible implementation method in the tenth aspect can refer to the technical effects of the corresponding implementation method of the third aspect, and will not be repeated here.

[0082] In the eleventh aspect, a communication device is provided, which may be a first terminal device, or a chip or circuit of the first terminal device, which is not limited in the present application.

[0083] The communication device includes: a transceiver unit, used to send a first request message to a second terminal device, the first request message is used to request to re-establish a connection between the first terminal device and the access network device; a processing unit, used to reconstruct a third entity, the third entity is used for the first terminal device to send a message to the second terminal device; the transceiver unit is used to receive first information from the second terminal device, the first information includes first data and a first identifier, the first data is encrypted using a first key, the first identifier is an identifier of the first terminal device, and the first identifier is used for a sidelink relay adaptation layer; the processing unit is also used to stop processing the first data.

[0084] In a possible implementation, the communication device also includes a third entity and a fourth entity, the fourth entity is a wireless link control entity, and the processing unit is specifically used to stop delivering the first data to the third entity through the fourth entity, or to discard the first data through the fourth entity.

[0085] In a possible implementation, the transceiver unit is further used to stop sending data to the second terminal device, where the data includes data sent by the first terminal device to the access network device via the second terminal device.

[0086] The technical effects of any possible implementation method in the eleventh aspect can refer to the technical effects of the corresponding implementation method of the fourth aspect, and will not be repeated here.

[0087] In a twelfth aspect, a communication device is provided, which may be a second terminal device, or a chip or circuit of the second terminal device, which is not limited in the present application.

[0088] The communication device includes: a transceiver unit, used to send a second request message to the access network device, the second request message is used to request to re-establish the connection between the second terminal device and the access network device; a processing unit, used to reconstruct the fifth entity, the fifth entity is used for the second terminal device to forward the message transmitted between the first terminal device and the access network device; the transceiver unit is also used to receive third information from the first terminal device, the third information includes second data and a first identifier, the second data is encrypted using a first key, the first identifier is the identifier of the first terminal device, and the first identifier is used for the sidelink relay adaptation layer; the processing unit is also used to stop processing the second data.

[0089] In a possible implementation, the communication device further includes: a processing unit, configured to reconstruct a fifth entity, the fifth entity being used by the second terminal device to forward a message transmitted between the first terminal device and the access network device. The communication device further includes a fifth entity and a sixth entity, the sixth entity being a radio link control entity, and the processing unit being further specifically configured to stop delivering the second data to the fifth entity through the sixth entity, or discard the second data through the sixth entity.

[0090] In a possible implementation, the transceiver unit is further used to stop sending data to the first terminal device, where the data includes data sent by the access network device to the first terminal device via the second terminal device.

[0091] In a thirteenth aspect, a communication device is provided, which may be an access network device, or a chip or circuit of an access network device, which is not limited in the present application.

[0092] The communication device includes: a transceiver unit, used to send a sixth message to a second terminal device, the sixth message is used to indicate a second identifier and a second key; a transceiver unit, used to receive third information from the second terminal device, the third information includes second data and a first identifier, the second data is encrypted using a first key, and the second terminal device is used to provide a relay service for the communication between the first terminal device and the access network device; a processing unit, used to process the second data using the first key. The first identifier and the second identifier are identifiers of the first terminal device, and the first identifier and the second identifier are used for the sidelink relay adaptation layer.

[0093] In a possible implementation manner, the processing unit is further specifically configured to decrypt the second data or discard the second data according to the first identifier.

[0094] In a possible implementation, the processing unit is further specifically configured to: determine, based on the first identifier, that the second data is encrypted using the first key; and decrypt the second data or discard the second data.

[0095] The technical effects of any possible implementation method in the thirteenth aspect can refer to the technical effects of the corresponding implementation method of the sixth aspect, and will not be repeated here.

[0096] In a fourteenth aspect, a communication device is provided, which may be a second terminal device, or a chip or circuit of the second terminal device, which is not limited in the present application.

[0097] The communication device includes: a processing unit, which is used to: initiate the re-establishment between the second terminal device and the access network device; release the first entity and the second entity; apply the first predefined configuration to the third entity; and apply the second predefined configuration to the fourth entity. The first entity and the third entity are used for the second terminal device to receive a first request message from the first terminal device, and the second entity and the fourth entity are used for the second terminal device to receive a fourth message from the first terminal device, the first request message is used to request to re-establish the connection between the first terminal device and the access network device, and the fourth message is used to indicate that the connection between the first terminal device and the access network device has been re-established.

[0098] The technical effects of any possible implementation method in the fourteenth aspect can refer to the technical effects of the corresponding implementation method of the seventh aspect, and will not be repeated here.

[0099] In the fifteenth aspect, a communication device is provided, comprising: at least one processor, the at least one processor being coupled to at least one memory, the at least one processor being used to execute a computer program or instruction stored in the at least one memory, so that the communication device executes a communication method in any possible implementation of the first to seventh aspects mentioned above.

[0100] In a sixteenth aspect, a processor is provided for executing a communication method in any possible implementation of the first to seventh aspects.

[0101] For the operations such as sending and acquiring / receiving involved in the processor, unless otherwise specified, or unless they conflict with their actual function or internal logic in the relevant description, they can be understood as operations such as processor output, reception, input, etc., or as sending and receiving operations performed by the radio frequency circuit and antenna, and this application does not limit this.

[0102] In the seventeenth aspect, a chip system is provided, comprising: a processor for calling and running a computer program from a memory, so that a communication device equipped with the chip system executes a communication method in any possible implementation of the first to seventh aspects above.

[0103] Optionally, as an implementation method, the chip also includes a memory, in which a computer program or instructions are stored, and the processor is used to execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the processor is used to execute the communication method in any possible implementation of the first to seventh aspects above.

[0104] In an eighteenth aspect, a computer program product comprising instructions is provided. When the computer program product is run on a communication device, the communication device executes a communication method in any possible implementation of the first to seventh aspects.

[0105] In a nineteenth aspect, a computer-readable storage medium is provided, which stores a program code for execution by a device, wherein the program code includes instructions for executing a communication method provided by any possible implementation of the first to seventh aspects.

[0106] In the twentieth aspect, a chip is provided, comprising at least one processor and a communication interface, wherein the communication interface is used to receive data and / or information and transmit the received data and / or information to the processor, and the processor processes the data and / or information to execute the communication method in any possible implementation of the first to seventh aspects above.

[0107] In a twenty-first aspect, a communication system is provided, comprising a first terminal device and a second terminal device, wherein the first terminal device is used to execute the communication method in any possible implementation of the first aspect; and the second terminal device is used to execute the communication method in any possible implementation of the second aspect.

[0108] In aspect 22, a communication system is provided, comprising a first terminal device and at least one of the following: a second terminal device and an access network device. The first terminal device is used to execute the communication method in any possible implementation of the third aspect; or the first terminal device is used to execute the communication method in any possible implementation of the fourth aspect.

[0109] In a twenty-third aspect, a communication system is provided, comprising a second terminal device and an access network terminal device, wherein the second terminal device is used to execute the communication method in any possible implementation of the fifth aspect; and the access network device is used to execute the communication method in any possible implementation of the sixth aspect.

[0110] In a twenty-fourth aspect, a communication system is provided, comprising a first terminal device, a second terminal device and an access network device, wherein the access network device is used to execute the communication method in any possible implementation of the seventh aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0111] Figure 1 A schematic diagram of the architecture of an example communication system applicable to an embodiment of the present application.

[0112] Figure 2 For L2-based Figure 1 The protocol stack diagram of the communication system shown.

[0113] Figure 3 A schematic flowchart of a communication method provided in an embodiment of the present application.

[0114] Figure 4 A schematic flowchart of another communication method provided in an embodiment of the present application.

[0115] Figure 5 A schematic flowchart of another communication method provided in an embodiment of the present application.

[0116] Figure 6 A schematic flowchart of another communication method provided in an embodiment of the present application.

[0117] Figure 7 A schematic flowchart of another communication method provided in an embodiment of the present application.

[0118] Figure 8A schematic flowchart of another communication method provided in an embodiment of the present application.

[0119] Fig. 9 A schematic flowchart of another communication method provided in an embodiment of the present application.

[0120] Fig.10 A schematic flowchart of another communication method provided in an embodiment of the present application.

[0121] Fig.11 A schematic flowchart of another communication method provided in an embodiment of the present application.

[0122] Fig.12 A schematic structural diagram of an example of a communication device provided in an embodiment of the present application.

[0123] Fig.13 A schematic block diagram of another communication device provided in an embodiment of the present application.

[0124] Fig.14 It is a schematic block diagram of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0125] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0126] In order to facilitate understanding of the embodiments of the present application, the following points are explained before introducing the embodiments of the present application.

[0127] First, in the embodiments of the present application, "indication" may include direct indication and indirect indication, and may also include explicit indication and implicit indication. The information indicated by a certain signal (such as the first information described below) is called information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, such as but not limited to, the information to be indicated may be directly indicated, such as the information to be indicated itself or the index of the information to be indicated. The information to be indicated may also be indirectly indicated by indicating other information, wherein the other information has an association relationship with the information to be indicated. It is also possible to indicate only a part of the information to be indicated, while the other parts of the information to be indicated are known or agreed in advance. For example, the indication of specific information may also be achieved by means of the arrangement order of each information agreed in advance (such as specified by the protocol), thereby reducing the indication overhead to a certain extent.

[0128] Second, the first, second and various digital numbers in the embodiments shown below are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application. For example, to distinguish different messages, information, etc.

[0129] Third, the “multiple” involved in the embodiments of the present application generally refers to two or more.

[0130] First, in the various embodiments of the present application, unless otherwise specified or logically conflicting, the terms and / or descriptions between the different embodiments are consistent and can be referenced to each other, and the technical features in the different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0131] In a wireless communication system, terminal devices can communicate data with each other through access network devices, or they can communicate directly with each other without the help of access network devices, which can effectively reduce communication delays.

[0132] The interface between terminal devices is called a PC5 interface, which is similar to the Uu interface between a terminal device and an access network device.

[0133] The link between terminal devices is called SL. A typical application scenario of SL communication is vehicle-to-everything (V2X). In the vehicle-to-everything (V2X) network, each vehicle can be considered as a terminal device.

[0134] SL supports broadcast communication, unicast communication, and multicast communication. The following describes broadcast communication, unicast communication, and multicast communication respectively.

[0135] (1) Broadcast Communications

[0136] Similar to the broadcast system information of access network equipment, that is, the terminal equipment sends the broadcast service data to the outside without encryption. Any other terminal equipment within the effective receiving range can receive the data of the broadcast service if it is interested in the broadcast service.

[0137] (2) Unicast communication

[0138] Similar to the data communication between the terminal device and the access network device after establishing a radio resource control (RRC) connection. In unicast communication, two terminal devices need to establish a unicast connection first, and after the unicast connection is established, the two terminal devices communicate data based on the negotiated identifiers (such as the source L2 ID and the destination L2 ID described below).

[0139] Among them, a unicast communication on the SL corresponds to a pair of IDs: source layer 2 identifier (L2 ID) and destination layer 2 identifier (Destination layer 2 identifier, Destination L2 ID). The subheader of each SL media access control protocol data unit (MAC PDU) will contain some bytes of the source L2 ID and some bytes of the destination L2 ID, so that the data can be transmitted to the correct receiving end.

[0140] The data transmitted between two terminal devices can be encrypted or unencrypted. Compared with broadcast communication, in unicast communication, the unicast communication can only be carried out between two terminal devices that have established a unicast connection.

[0141] (3)Multicast communication

[0142] Refers to the communication between all terminal devices in a communication group. Any terminal device in the group can send and receive data of the multicast service.

[0143] Radio bearer (RB): Radio bearer is a general term for a series of protocol entities and configurations allocated by access network equipment to UE. It is a service provided by Layer 2 for transmitting user data between UE and base station, including a series of resources allocated by packet data convergence protocol (PDCP) protocol entity, radio link control (RLC) protocol entity, medium access control layer (MAC) protocol entity and physical layer (PHY) protocol entity. Radio bearers are divided into data radio bearers (DRB) and signaling radio bearers (SRB). The former is used to carry data, and the latter is used to carry signaling messages.

[0144] Combine the following Figure 1 and Figure 2 The U2N relay communication system provided in the embodiment of the present application is introduced.

[0145] Figure 1 A schematic diagram of the architecture of an example communication system applicable to an embodiment of the present application.

[0146] For example, Figure 1As shown, the U2N relay communication system 100 includes: a first terminal device (also referred to as remote UE), at least one second terminal device (also referred to as relay UE), and an access network device. The second terminal device is used to provide relay services for communication between the first terminal device and the access network device.

[0147] In the communication system 100, the second terminal device communicates with the first terminal device via a sidelink (SL) (eg, a PC5 interface), and the second terminal device communicates with the access network device via an air interface (eg, a Uu interface).

[0148] It should be understood that the second terminal device and the first terminal device (hereinafter collectively referred to as terminal devices) are a type of device with wireless transceiver functions, which may refer to user equipment (UE), access terminal, subscriber unit, user station, mobile station, remote station, remote terminal, mobile device, user terminal, wireless communication equipment, user agent or user device. The terminal device 120 may also be a satellite phone, a cellular phone, a smart phone, a wireless data card, a wireless modem, a machine type communication device, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a customer-premises equipment (CPE), a smart point of sale (POS) machine, a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a communication device carried on a high-altitude aircraft, a wearable device, a drone, a robot, a terminal in device-to-device communication (D2D), a terminal in vehicle-to-everything (V2X), a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a remote medical device, or a wireless terminal in medical equipment. This application does not limit the wireless terminals in medical, smart grid, transportation safety, smart city, smart home, or terminal devices in communication networks evolved after 5G.

[0149] The communication device for realizing the function of the terminal device can be a terminal device, or a device that can support the terminal device to realize the function, such as a chip system. The device can be installed in the terminal device or used in combination with the terminal device. In the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0150] Access network equipment is a device with wireless transceiver functions, which is used to communicate with terminal equipment. Access network equipment can be a node in the radio access network (RAN), which can be called a base station or a RAN node. It can be an evolved Node B (eNB or eNodeB) of long term evolution (LTE); or a base station of a 5G network such as gNodeB (gNB) or a base station in a public land mobile network (PLMN) evolved after 5G, a broadband network service gateway (BNG), an aggregation switch or the 3rd generation partnership project (3GPP) access equipment, etc.

[0151] The above-mentioned RAN can be configured as a RAN defined by the 3GPP protocol, an open radio access network (O-RAN) or a cloud radio access network (C-RAN), etc. The access network device 110 can also include various forms of base stations, such as: macro base stations, micro base stations (also called small stations), relay stations, transmission points (transmitting and receiving points, TRP), transmission points (transmitting points, TP), mobile switching centers, and devices that assume the function of base stations in device-to-device (D2D), vehicle-to-everything (V2X), machine-to-machine (M2M) communications, access network devices in non-terrestrial networks (NTN), etc., without specific limitation.

[0152] The access network equipment may also include network elements or modules that implement some functions of the base station, for example, one or more of the following: a centralized unit (CU), a distributed unit (DU), or a radio unit (RU). Optionally, the CU can be further separated into a CU-control plane (CP) and a CU-user plane (UP). The functions of the CU and DU can be implemented by different network elements, or simultaneously by the baseband unit (BBU) of the base station. The function of the RU can be implemented by the radio frequency equipment of the base station. For example, the radio frequency equipment of the base station may be a remote radio unit (RRU), a pico remote radio unit (pRRU), an active antenna unit (AAU), or other units, modules or devices with radio frequency processing functions. The communication interface protocol between the BBU and the radio frequency equipment can be a common public radio interface (CPRI) interface protocol, an enhanced common public radio interface (eCPRI) interface protocol, or a fronthaul interface protocol between the DU and the RU in the O-RAN system, etc., without limitation.

[0153] In different systems, 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, in the ORAN system, CU may also be called O-CU (Open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the convenience of description, CU, CU-CP, CU-UP, DU and RU are used as examples for description in this application.

[0154] The communication device for implementing the function of the access network device may be an access network device, or may be a device capable of supporting the access network device to implement the function, such as a chip system. The device may be installed in the access network device or used in conjunction with the access network device. The chip system in the embodiment of the present application may be composed of a chip, or may include a chip and other discrete devices.

[0155] The communication system 100 can also be the following systems: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, universal mobile telecommunication system (UMTS), 5G system, 6G system, intersatellite communication and satellite communication and other NTN systems. Among them, the satellite communication system includes a satellite base station and a terminal device. The satellite base station provides communication services for the terminal device. The satellite base station can also communicate with the ground base station. The satellite can be used as a base station or as a terminal device. Among them, the satellite can refer to non-ground base stations or non-ground equipment such as drones, hot air balloons, low-orbit satellites, medium-orbit satellites, and high-orbit satellites.

[0156] The communication system 100 may also be a ground cellular communication system, a high altitude platform station (HAPS) communication system, a V2X system, an integrated access and backhaul (IAB) system, and a reconfigurable intelligent surface (RIS) communication system, etc., without limitation.

[0157] It should be understood that Figure 1 The simplified schematic diagram is only for the sake of understanding. The communication system may also include other devices. Figure 1 Not drawn in.

[0158] Currently, there are two possible implementations of U2N relay technology: layer 3 (L3) relay and L2 relay. In the L2 relay, the user plane data is forwarded below the PDCP layer. Figure 2 shown.

[0159] Figure 2 For L2-based Figure 1 The protocol stack diagram of the communication system shown.

[0160] For example, Figure 2As shown, the user plane protocol stack of the first terminal device includes: Uu-PDCP layer, PC5 relay adaptation protocol (sidelink relay adaptation protocol, PC5-SRAP) layer, PC5-RLC layer, PC5-MAC layer, and PC5-PHY layer. The user plane protocol stack of the second terminal device includes: PC5-SRAP layer, PC5-RLC layer, PC5-MAC layer, PC5-PHY layer, Uu-SRAP layer, Uu-RLC layer, Uu-MAC layer, and Uu-PHY layer. The user plane protocol stack of the access network device includes: Uu-PDCP layer, Uu-SRAP layer, Uu-RLC layer, Uu-MAC layer, and Uu-PHY layer.

[0161] The data packets of the first terminal device are relayed below the PDCP layer of the second terminal device, that is, the second terminal device only maintains the relayed RLC bearer, including the RLC layer, MAC layer and PHY layer. Therefore, there is an end-to-end Uu-PDCP layer between the first terminal device and the access network device, but there is no end-to-end RLC, MAC and PHY layer.

[0162] In addition, if Figure 2 The protocol architecture shown adds PC5-SRAP between the RLC layer and the PDCP layer. The main function of the PC5-SRAP layer is to multiplex and demultiplex bearers, that is, to support different bearers to be multiplexed into one bearer or to split one bearer into different bearers, and to distinguish data of different first terminal devices. The SRAP in the protocol stack at both ends of the PC5 port is called PC5-SRAP, and the SRAP in the protocol stack at both ends of the Uu port is called Uu-SRAP.

[0163] In the U2N relay scenario, data forwarding is achieved through SRAP configuration. The access network device will configure the mapping relationship between DRB and PC5 RLC channel (PC5 RLC channel) and the local ID (local ID) for the first terminal device, and the first terminal device sends uplink data according to the configuration. Correspondingly, the access network device will configure the mapping relationship between DRB and UuRLC channel (Uu RLC channel) and the local ID of the first terminal device for the second terminal device, and the second terminal device forwards uplink data according to the configuration. The access network device will configure the mapping relationship between DRB and PC5 RLC channel and the local ID of the first terminal device for the second terminal device, and the second terminal device forwards downlink data according to the configuration.

[0164] For uplink transmission, the SRAP header of the data packet carries the local ID and the bearer identifier (BEARER ID). After the second terminal device receives the data packet from the first terminal device, it determines that the data packet comes from the first terminal device based on the local ID, and further forwards the data packet to the access network device based on the mapping relationship between the DRB and the Uu RLC channel. The access network device delivers the data packet to the corresponding PDCP entity based on the BEARER ID. For downlink transmission, the SRAP header of the data packet carries the local ID and the BEARERID. After the second terminal device receives the data packet from the access network device, it determines that the data packet is to be forwarded to the first terminal device based on the local ID, and further forwards the data packet to the first terminal device based on the mapping relationship between the DRB and the PC5 RLC channel. The first terminal device delivers the data packet to the corresponding PDCP entity based on the BEARER ID.

[0165] In the U2N relay scenario, if a radio link failure (RLF) is sent on the Uu port between the second terminal device and the access network device, the second terminal device will send a sidelink notification message to the first terminal device, indicating that the Uu of the second terminal device has an RLF. After receiving the message, the first terminal device will execute the RRC connection re-establishment process, during which the first terminal device will release the SRAP entity and SRAP configuration. Similarly, the second terminal device will also trigger the RRC connection re-establishment process and release the SRAP entity and SRAP config accordingly.

[0166] Since the entities and configurations of the RLC layer and the layers below RLC of the first terminal device and the second terminal device have not been released, the first terminal device can still send data packets on the PC5RLC channel during the process of re-establishing the RRC connection of the second terminal device, that is, the data packets submitted to the RLC layer and the layers below RLC before the first terminal device triggers the RRC re-establishment. These data packets are encrypted by the original key, where the original key refers to the key used by the second terminal device to decrypt the data packets before re-establishing the RRC connection. When the second terminal device re-establishes the RRC connection, the access network device will send configuration information, and the second terminal device will create a new SRAP entity based on the configuration information and forward these data packets to the access network device. During the process of re-establishing the RRC connection of the first terminal device, the access network device will update the key. Therefore, when the access network device receives the data packets encrypted by the original key, it will use the new key to decrypt the erroneous data.

[0167] Based on this, the present application embodiment provides Figures 3 to 10 The communication method shown, Figures 3 to 10 The communication method shown is applied to Figure 1 The U2N relay communication system 100 shown in the figure. The communication method includes a first terminal device, one or more second terminal devices and an access network device. The first terminal device communicates with the access network device through the one or more second terminal devices, or the one or more second terminal devices provide relay services for the communication between the first terminal device and the access network device. Figures 3 to 10 The communication method provided in the embodiment of the present application is described in detail.

[0168] The interaction flow chart in this application uses the first terminal device, the second terminal device and the access network device as examples of the execution subjects of the interaction diagram to illustrate the corresponding method, but this application does not limit the execution subjects of the interaction diagram. For example, the first terminal device in the figure can also be a chip, a chip system, or a processor that supports the first terminal device to implement the corresponding method, and can also be a logic module or software that can implement all or part of the functions of the first terminal device; the second terminal device in the figure can also be a chip, a chip system, or a processor that supports the second terminal device to implement the corresponding method, and can also be a logic module or software that can implement all or part of the functions of the second terminal device. The access network device in the figure can also be a chip, a chip system, or a processor that supports the access network device to implement the corresponding method, and can also be a logic module or software that can implement all or part of the functions of the access network device.

[0169] Figure 3 A schematic flowchart of a communication method 300 provided in an embodiment of the present application.

[0170] like Figure 3 As shown, the communication method 300 includes S301 and S302. S301 and S302 are described in detail below.

[0171] S301, a second terminal device sends a first message to a first terminal device, the first message being used to indicate that a radio link failure occurs between the second terminal device and an access network device. Correspondingly, the first terminal device receives a sidelink notification message sent by the second terminal device.

[0172] Exemplarily, the first message may be a sidelink notification message.

[0173] The triggering condition of S301 may be that the second terminal device detects that a radio link failure (RLF) occurs on the Uu interface between the second terminal device and the access network device.

[0174] S302, the first terminal device stops sending data to the second terminal device, wherein the data includes data sent by the first terminal device to the access network device via the second terminal device.

[0175] In some embodiments, the first terminal device stops sending data to the second terminal device, including each protocol layer entity of the first terminal device stops processing data and does not submit PDU to the lower layer.

[0176] For example, the protocol layer of the first terminal device includes: Figure 2 The Uu-PDCP layer, PC5-SRAP layer, PC5-RLC layer, PC5-MAC layer, and PC5-PHY layer shown in the figure, wherein the lower layer of the Uu-PDCP layer includes the PC5-SRAP layer, the lower layer of the PC5-SRAP layer includes the PC5-RLC layer, the lower layer of the PC5-RLC layer includes the PC5-MAC layer, and the lower layer of the PC5-MAC layer includes the PC5-PHY layer. The various protocol layer entities of the first terminal device stop processing data, that is, the Uu-PDCP layer, PC5-SRAP layer, PC5-RLC layer, PC5-MAC layer, and PC5-PHY layer of the first terminal device stop processing data respectively. The various protocol layer entities of the first terminal device do not submit PDUs to the lower layers, that is, the Uu-PDCP layer entity of the first terminal device does not submit PDUs to the PC5-SRAP layer, the PC5-SRAP layer entity of the first terminal device does not submit PDUs to the PC5-RLC layer, the PC5-RLC layer entity of the first terminal device does not submit PDUs to the PC5-MAC layer, and the PC5-MAC layer entity of the first terminal device does not submit PDUs to the PC5-PHY layer.

[0177] In some embodiments, the first terminal device stops sending data to the second terminal device, including the first terminal device releasing the first entity. The first entity is used by the first terminal device to send a message to the second terminal device. For example, the first entity may be an RLC entity. In this way, since the first terminal device releases the first entity, the first terminal device clears the uplink data cached on the first terminal device side, and the first terminal device will not send uplink data to the second terminal device.

[0178] Furthermore, in some embodiments, the first terminal device stops sending data to the second terminal device further includes: re-establishing an entity of the same type as the first entity; and performing a MAC reset. The re-establishing an entity of the same type as the first entity is performed after the first terminal device releases the first entity.

[0179] For example, the first terminal device releases the RLC entity, re-establishes the RLC entity, and releases the configuration related to the MAC layer.

[0180] Through S301 and S302, when RLF occurs on the Uu interface of the second terminal device, after the first terminal device receives the first message sent by the second terminal device, it stops uplink data transmission or the various protocol layer entities of the first terminal device stop processing data, and does not submit PDU to the lower layer. In this way, during the RRC reconstruction process of the first terminal device, the first terminal device clears the cached uplink data. Therefore, after the first terminal device performs RRC reconstruction, the access network device will not receive the data packet encrypted by the original key, and thus no erroneous data will be decrypted.

[0181] In some embodiments, the first terminal device may also clear uplink data cached on the first terminal device side.

[0182] In some embodiments, the first terminal device clears the uplink data cached on the first terminal device side, including the first terminal device rebuilding the first entity. Here, it can be considered that the first terminal device has a function of rebuilding the first entity of the first terminal device and the PC5 of the second terminal device. For example, the first terminal device clears the uplink data cached on the first terminal device side, including the first terminal device rebuilding the RLC entity.

[0183] In some other embodiments, the first terminal device clears the uplink data cached on the first terminal device side, including: the first terminal device releases the first entity; the first terminal device reestablishes an entity of the same type as the first entity. For example, the first terminal device clears the uplink data cached on the first terminal device side, including the first terminal device releasing the RLC entity and reestablishing the RLC entity.

[0184] Optionally, in some embodiments, when the first condition is met, the first terminal device clears the uplink data cached on the first terminal device side, that is, when the first condition is met, the first terminal device rebuilds the first entity or the first terminal device releases the first entity.

[0185] Among them, the first condition includes that the first terminal device receives the first message or the first terminal device sends the first request message. In other words, when the first terminal device receives the first message or when the first terminal device sends the first request message, the first terminal device reconstructs the first entity or the first terminal device releases the first entity. For the relevant description of the first entity, please refer to the above, which will not be repeated here. For the first request message, please refer to the relevant description in S303a below, which will not be repeated here.

[0186] Further, in some embodiments, after the first terminal device reestablishes the first entity or after the first terminal device reestablishes an entity of the same type as the first entity, the first terminal device performs a MAC reset. MAC reset can be understood as releasing the configuration related to the MAC layer.

[0187] It should be noted that if the first terminal device stops sending data to the second terminal device in S302, including the first terminal device releasing the first entity, the first terminal device does not need to clear the uplink data cached on the first terminal device side. If the first terminal device stops sending data to the second terminal device in S302, including the first terminal device releasing the first entity, after S302, the first terminal device clears the uplink data cached on the first terminal device side.

[0188] In some embodiments, the first terminal device may also stop receiving data from the second terminal device, the data including data sent by the access network device to the first terminal device via the second terminal device. In this way, it is possible to avoid the first terminal device receiving a data packet encrypted by the access network device using the original key during the process of re-establishing the connection with the access network device, thereby avoiding the first terminal device using the new key to decode erroneous data after the first terminal device re-establishes the connection with the access network device.

[0189] Specifically, when the second condition is met, the first terminal device releases the first configuration. The first configuration is used for the first terminal device to receive a message from the second terminal device. The second condition includes the first terminal device receiving the first message or the first terminal device sending the first request message. In other words, when the first terminal device receives the first message or when the first terminal device sends the first request message, the first terminal device releases the first configuration.

[0190] Exemplarily, the first configuration is allocated by the second terminal device to the first terminal device. The first configuration may include an RLC mode, an RLC sequence number, a logical channel identifier, and the like.

[0191] Figure 4 A schematic flowchart of another communication method 400 provided in an embodiment of the present application.

[0192] Optionally, in some embodiments, Figure 4 As shown, in addition to S301 and S302, the communication method 400 may also include S303a, S303b, S304a, S304b, S305a, S305b, S306a, S306b, S307, S401 to S406. Among them, S303a, S303b, S304a, S304b, S305a, S305b, S306a, S306b, S307 are the process of the first terminal device re-establishing the connection with the access network device. S402 to S406 are the process of the second terminal device re-establishing the connection with the access network device. The present application does not limit the execution order of S303a and S302, S401, S402, S403, S404, S405, and S406, and whether they are executed simultaneously. The execution order of S302 to S401, and whether they are executed simultaneously, are also not limited. S303b is executed after S405, and S401 is an optional step. The following describes in detail the other steps of the communication method 400 except S301 and S302.

[0193] S401, the second terminal device stops sending data to the first terminal device, wherein the data includes data sent by the access network device to the first terminal device via the second terminal device.

[0194] In some embodiments, the second terminal device stops sending data to the first terminal device, including each protocol layer entity of the second terminal device stops processing data and does not submit PDU to the lower layer.

[0195] For example, the protocol layer of the second terminal device includes: Figure 2 The PC5-SRAP layer, PC5-RLC layer, PC5-MAC layer, and PC5-PHY layer shown in . The various protocol layer entities of the second terminal device stop processing data, that is, the PC5-SRAP layer, PC5-RLC layer, PC5-MAC layer, and PC5-PHY layer of the second terminal device stop processing data respectively. The various protocol layer entities of the second terminal device do not submit PDUs to the lower layer, that is, the PC5-SRAP layer entity of the second terminal device does not submit PDUs to the PC5-RLC layer, the PC5-RLC layer entity of the second terminal device does not submit PDUs to the PC5-MAC layer, and the PC5-MAC layer entity of the second terminal device does not submit PDUs to the PC5-PHY layer.

[0196] In some embodiments, the second terminal device stops sending data to the first terminal device, including the second terminal device releasing the second entity. The second entity is used by the second terminal device to send a message to the first terminal device. For example, the second entity may be an RLC entity. In this way, since the second terminal device releases the second entity, the downlink data cached on the second terminal device side has no corresponding second entity transmission, the second terminal device will not send downlink data to the first terminal device, and the second terminal device clears the downlink data cached on the second terminal device side.

[0197] In some embodiments, the second terminal device may also clear the downlink data cached on the second terminal device side.

[0198] In some embodiments, the second terminal device clears the uplink data cached on the second terminal device side, including the second terminal device rebuilding the second entity. Here, it can be considered that the second terminal device has a function of rebuilding the second entity of the first terminal device and the PC5 of the second terminal device. For example, the second terminal device clears the downlink data cached on the second terminal device side, including the second terminal device rebuilding the RLC entity.

[0199] In some other embodiments, the second terminal device clears the downlink data cached on the second terminal device side, including: the second terminal device releases the second entity; the second terminal device reestablishes an entity of the same type as the second entity. For example, the second terminal device clears the downlink data cached on the second terminal device side, including the second terminal device releasing the RLC entity and reestablishing the RLC entity.

[0200] Optionally, in some embodiments, when the third condition is met, the second terminal device clears the downlink data cached on the second terminal device side, that is, when the third condition is met, the second terminal device rebuilds the second entity or the second terminal device releases the second entity.

[0201] Among them, the third condition includes one of the following: the second terminal device detects that a wireless link failure occurs between the second terminal device and the access network device; the second terminal device sends a first message; the second terminal device sends a second request message. In other words, when the second terminal device detects that a wireless link failure occurs between the second terminal device and the access network device, when the second terminal device sends the first message, or when the second terminal device sends the second request message, the second terminal device reconstructs the second entity or the second terminal device releases the second entity. For the relevant description of the second entity, please refer to the above, which will not be repeated here. For the second request message, please refer to the relevant description in S402 below, which will not be repeated here.

[0202] Further, in some embodiments, after the second terminal device reestablishes the second entity or after the second terminal device reestablishes an entity of the same type as the second entity, the second terminal device performs a MAC reset. MAC reset can be understood as releasing configuration related to the MAC layer.

[0203] It should be noted that if the second terminal device stops sending data to the first terminal device in S401, including the second terminal device releasing the second entity, the second terminal device does not need to clean up the downlink data cached on the second terminal device side. If the second terminal device stops sending data to the second terminal device in S401, including the second terminal device releasing the second entity, after S401, the second terminal device cleans up the downlink data cached on the second terminal device side.

[0204] In some embodiments, the second terminal device may also stop receiving data from the first terminal device, the data including data sent by the first terminal device to the access network device through the second terminal device. In this way, it is possible to avoid the second terminal device forwarding to the access network device data packets received from the first terminal device encrypted with the original key during the process of re-establishing the connection with the access network device, thereby avoiding the access network device from decrypting erroneous data using the new key after the first terminal device re-establishes the connection with the access network device.

[0205] Specifically, when the fourth condition is met, the second terminal device releases the second configuration. The second configuration is used for the second terminal device to receive a message from the first terminal device. The fourth condition includes one of the following: the second terminal device detects that a radio link failure occurs between the second terminal device and the access network device; the second terminal device sends a first message; the second terminal device sends a second request message. In other words, when the second terminal device detects that a radio link failure occurs between the second terminal device and the access network device, when the second terminal device sends the first message, or when the second terminal device sends the second request message, the second terminal device releases the second configuration.

[0206] Exemplarily, the first configuration is allocated by the first terminal device to the second terminal device. The second configuration may include an RLC mode, an RLC sequence number, a logical channel identifier, and the like.

[0207] The following is a detailed description of the process of reestablishing the connection between the first terminal device and the access network device.

[0208] S303a, the first terminal device sends a first request message to the second terminal device, the first request message is used to request to re-establish the connection between the first terminal device and the access network device. Correspondingly, the second terminal device receives the first request message from the first terminal device.

[0209] Exemplarily, the first request message may be a radio resource control reestablishment request (RRC reestablishment request) message, and the first request is specifically used to request establishment of an RRC connection between the first terminal device and the access network device.

[0210] S303b, the second terminal device sends a first request message to the access network device. Correspondingly, the access network device receives the first request message from the second terminal device.

[0211] In some embodiments, after receiving the first request message, the second terminal device does not process the content of the first request message, but forwards the first request message carrying the SRAP header to the access network device.

[0212] S304a, the access network device sends a first response message to the second terminal device, the first response message is a response message of the access network device to the first request message described in S303b. Accordingly, the second terminal device receives the first response message sent by the access network device.

[0213] Exemplarily, the first response message may be an RRC Reestablishment message.

[0214] Exemplarily, the first response message is also used to indicate a second key, which is used to decrypt data transmitted after the first terminal device reestablishes a connection with the access network device. In other words, the second key is a reestablished key. For example, the first response message includes a next hop chaining count (NCC) parameter, which is used to determine the second key.

[0215] In some embodiments, the access network device accepts to re-establish a connection with the first terminal device, and the access network device executes S304; the access network device refuses to re-establish a connection with the first terminal device, and the access network device does not execute S304a.

[0216] In some other embodiments, the access network device executes S304a regardless of whether the access network device accepts to re-establish the connection with the first terminal device. Here, the first response message is used to indicate that the access network device accepts or refuses to re-establish the connection with the first terminal device.

[0217] S304b, the second terminal device sends a first response message to the first terminal device. Correspondingly, the first terminal device receives the first response message sent by the second terminal device.

[0218] In some embodiments, after receiving the first response message, the second terminal device directly forwards the first response message to the first terminal device.

[0219] In an embodiment where the access network device accepts to re-establish a connection with the first terminal device and the access network device executes S304, the first terminal device receives a first response message and the first terminal device executes S305a. In an embodiment where the access network device executes S304a regardless of whether the access network device accepts to re-establish a connection with the first terminal device, the first terminal device receives the first response message, determines that the first response message is used to indicate that the access network device accepts to re-establish a connection with the first terminal device, and the first terminal device executes S305a.

[0220] S305a, the first terminal device sends a fourth message to the second terminal device, the fourth message is used to indicate that the connection between the first terminal device and the access network device has been reestablished. Correspondingly, the second terminal device receives the fourth message from the first terminal device.

[0221] Exemplarily, the fourth message may be an RRC reestablishment complete (RRCReestablishmentComplete) message. When the first terminal device and the access network device successfully complete the RRC reestablishment, the first terminal device executes S305a.

[0222] S305b, the second terminal device sends a fourth message to the access network device. Correspondingly, the access network device receives the fourth message from the second terminal device.

[0223] In some embodiments, after receiving the fourth message, the second terminal device does not process the content of the fourth message in any way, and directly forwards the fourth message to the access network device.

[0224] S306a, the access network device sends a second message to the second terminal device. Correspondingly, the second terminal device receives the second message from the access network device.

[0225] Among them, the second message is used to modify the RRC connection between the first terminal device and the access network device.

[0226] Exemplarily, the second message may be an RRC reconfiguration message (RRCRecongfiguration).

[0227] Exemplarily, the second message is used to indicate one of the following: one or more added or modified PC5 relay RLC channel configurations, and one or more released PC5 relay RLC channel configurations; full configuration (fullConfig) reconfiguration indication information and one or more added or modified radio link control channel configurations; one or more added or modified radio link control channel configurations.

[0228] Exemplarily, one or more released radio link control channel configurations indicate one or more PC5 RLC channel identifiers that need to be released, and one or more added or modified radio link control channel configurations include one or more PC5 RLC channel identifiers that need to be newly added, RLC configuration and MAC configuration, wherein the RLC configuration includes the RLC mode and corresponding parameters, and the MAC configuration includes sidelink logical channel parameters.

[0229] This embodiment of the present application does not limit the form of the one or more released radio link control channel configurations indicated by the second message.

[0230] For example, the second message may indicate one or more released radio link control channel configurations in the form of a list. Here, the list may be referred to as a radio link control channel release list of the first terminal device and the second terminal device.

[0231] For another example, the second message may indicate one or more released radio link control channel configurations through a first information element. Here, the first information element may be called sl-RLC-Channel To Release List. The first information element may include one or more RLC channel IDs. Here, the RLC channel ID is previously configured.

[0232] The embodiment of the present application does not limit the form of the one or more added or modified radio link control channel configurations indicated by the second message.

[0233] For example, the second message may indicate one or more added or modified radio link control channel configurations in the form of a list. Here, the list may be referred to as a radio link control channel addition or modification list of the first terminal device and the second terminal device.

[0234] For another example, the second message may indicate one or more added or modified radio link control channel configurations through a second information element. Here, the second information element may be called sl-RLC-Channel To Add Mod List. The specific structure of the second information element may be one or more {RLC channel ID, configuration} configurations. Here, the RLC channel ID is not configured.

[0235] In some embodiments, when the first terminal device stops sending data to the second terminal device and the first terminal device does not release the PC5 RLC channel (including releasing the RLC entity, MAC reset, etc.), the second message is used for one of the following: one or more added or modified PC5 relay RLC channel configurations, and one or more released PC5 relay RLC channel configurations; full configuration (fullConfig) reconfiguration indication information and one or more added or modified radio link control channel configurations.

[0236] In some embodiments, when the first terminal device releases the PC5 RLC channel by itself (including releasing RLCentity, MAC reset, etc.), the present application does not limit the content carried by the second message. The content carried by the second message may depend on the implementation of the access network device, for example, the second message only carries the release configuration.

[0237] In some embodiments, when the first terminal device releases the first configuration, the second message is used to indicate one or more added or modified radio link control channel configurations.

[0238] S306b, the second terminal device sends a second message to the first terminal device. Correspondingly, the first terminal device receives the second message from the second terminal device.

[0239] In some embodiments, after receiving the second message, the second terminal device does not process the content of the second message in any way, and directly forwards the second message to the first terminal device.

[0240] S307: The first terminal device is configured according to the second message.

[0241] In the case where the second message is used to indicate: one or more added or modified radio link control channel configurations, and one or more released radio link control channel configurations, or in the case where the second message is used to indicate full configuration (fullConfig) reconfiguration indication information and one or more added or modified radio link control channels, the first terminal device releases and reconstructs the RLC channel (referred to as PC5RLC channel) on PC5 of the first terminal device and the second terminal device, and configures a logical channel for the MAC entity. Releasing and reconstructing the PC5 RLC channel includes releasing the RLC entity and the corresponding logical channel, and reconstructing the RLC entity.

[0242] In the case where the second message is used to indicate one or more added or modified radio link control channels, the first terminal device releases and reestablishes the PC5 RLC channel. Releasing the PC5 RLC channel includes releasing the RLC entity and the corresponding logical channel, and reestablishing the PC5 RLC channel includes reestablishing the RLC entity and the corresponding logical channel. Exemplarily, the first terminal device may process the configuration information carried in the second message according to the full configuration (fullConfig) by default, release / clear all current dedicated wireless configurations, including the PC5 RLC channel configuration, and establish the PC5 RLC channel according to the one or more PC5 relay RLC channel configurations to be added in the second message. Establishing the PC5 RLC channel includes establishing the RLCentity and configuring the logical channel for the MAC entity. It should be noted that, in this example, the one or more added or modified PC5 relay RLC channel configurations indicated by the second message include one or more PC5 relay RLC channel configurations that need to be added, and do not include one or more PC5 relay RLC channel configurations that need to be modified.

[0243] The following describes in detail the process of reestablishing the connection between the second terminal device and the access network device.

[0244] S402: The second terminal device sends a second request message to the access network device. Correspondingly, the access network device receives the second request message from the second terminal device.

[0245] Exemplarily, the second request message may be an RRC reestablishment request message, and the second request is specifically used to request establishment of an RRC connection between the second terminal device and the access network device.

[0246] S403, the access network device sends a second response message to the second terminal device, where the second response message is a response message of the access network device to the second request message described in S402. Accordingly, the second terminal device receives the second response message sent by the access network device.

[0247] Exemplarily, the second response message may be an RRC Reestablishment (RRCReestablishment) message.

[0248] In some embodiments, the access network device accepts to re-establish a connection with the second terminal device, and the access network device executes S403; the access network device refuses to re-establish a connection with the first terminal device, and the access network device does not execute S403.

[0249] In some other embodiments, the access network device executes S403 regardless of whether the access network device accepts to re-establish the connection with the second terminal device. Here, the second response message is used to indicate that the access network device accepts or refuses to re-establish the connection with the second terminal device.

[0250] S404, the second terminal device sends a fifth message to the first terminal device. Correspondingly, the first terminal device receives the fifth message sent by the second terminal device.

[0251] In an embodiment where the access network device accepts to re-establish a connection with the second terminal device, and the access network device executes S403, the second terminal device receives a second response message, and the second terminal device executes S404. In an embodiment where the access network device executes S403 regardless of whether the access network device accepts to re-establish a connection with the second terminal device, the second terminal device receives the second response message, determines that the second response message is used to indicate that the access network device accepts to re-establish a connection with the second terminal device, and the second terminal device executes S404.

[0252] Exemplarily, the fifth message may be an RRCReestablishment complete message. When the second terminal device and the access network device successfully complete the RRC reestablishment, the second terminal device executes S404.

[0253] S405: The access network device sends a third message to the second terminal device. Correspondingly, the second terminal device receives the third message from the access network device.

[0254] Among them, the third message is used to indicate the configuration information of the communication between the second terminal device and the access network device.

[0255] Exemplarily, the third message may be an RRC Recongfiguration message.

[0256] Exemplarily, the third message is used to indicate one of the following: one or more added or modified radio link control channel configurations, and one or more released radio link control channel configurations; full configuration (fullConfig) reconfiguration indication information and one or more added or modified radio link control channel configurations; one or more added or modified radio link control channel configurations. For a specific description of the content indicated by the third message, please refer to the above description, which will not be repeated here.

[0257] This embodiment of the present application does not limit the form of the one or more released radio link control channel configurations indicated by the third message.

[0258] For example, the third message may indicate one or more released radio link control channel configurations in the form of a list. Here, the list may be referred to as a radio link control channel release list of the first terminal device and the second terminal device.

[0259] For another example, the third message may indicate one or more released radio link control channel configurations through a third information element. Here, the third information element may be called sl-RLC-Channel To Release List. The specific structure of the third information element may be one or more RLC channel IDs. Here, the RLC channel ID is previously configured.

[0260] The embodiment of the present application does not limit the form of the one or more added or modified radio link control channel configurations indicated by the third message.

[0261] For example, the third message may indicate one or more added or modified radio link control channel configurations in the form of a list. Here, the list may be referred to as a radio link control channel addition list of the first terminal device and the second terminal device.

[0262] For another example, the third message may indicate one or more added or modified radio link control channel configurations through the fourth information element. Here, the fourth information element may be called sl-RLC-Channel To Add Mod List. The specific structure of the second fourth information element may be one or more {RLC channel ID, configuration} configurations. Here, the RLC channel ID is not configured.

[0263] In some embodiments, when the second terminal device stops sending data to the first terminal device and the first terminal device does not release the PC5 RLC channel (including releasing the RLC entity, MAC reset, etc.), the third message is used for one of the following: one or more added or modified PC5 relay RLC channel configurations, and one or more released PC5 relay RLC channel configurations; full configuration (fullConfig) reconfiguration indication information and one or more added or modified radio link control channel configurations.

[0264] In some embodiments, when the second terminal device releases the PC5 RLC channel by itself (including releasing RLCentity, MAC reset, etc.), the present application does not limit the content carried by the third message. The content carried by the third message may depend on the implementation of the access network device, for example, the third message only carries the release configuration.

[0265] In some embodiments, when the second terminal device releases the first configuration, the third message is used to indicate one or more added or modified radio link control channel configurations.

[0266] S406: The second terminal device is configured according to the third message.

[0267] In the case where the third message is used to indicate: one or more added or modified radio link control channel configurations, and one or more released radio link control channel configurations, or in the case where the third message is used to indicate full configuration (fullConfig) reconfiguration indication information and one or more added or modified radio link control channels, the second terminal device releases and reconstructs the PC5 RLC channel between the first terminal device and the second terminal device, and configures a logical channel for the MAC entity. Releasing and reconstructing the PC5 RLC channel includes releasing the RLC entity and the corresponding logical channel, and reconstructing the RLC entity.

[0268] In the case where the third message is used to indicate one or more added or modified radio link control channels, the second terminal device releases and reestablishes the PC5 RLC channel. Releasing the PC5 RLC channel includes releasing the RLC entity and the corresponding logical channel, and reestablishing the PC5 RLC channel includes reestablishing the RLC entity and the corresponding logical channel. Exemplarily, the second terminal device may process the configuration information carried in the third message according to the full configuration (fullConfig) by default, release / clear all current dedicated wireless configurations, including the PC5 RLC channel configuration, and establish the PC5 RLC channel according to the one or more PC5 relay RLC channel configurations to be added in the third message. Establishing the PC5 RLC channel includes establishing the RLCentity and configuring the logical channel for the MAC entity. It should be noted that, in this example, the one or more added or modified PC5 relay RLC channel configurations indicated by the third message include one or more PC5 relay RLC channel configurations that need to be added, and do not include one or more PC5 relay RLC channel configurations that need to be modified.

[0269] In this way, the second terminal device clears the downlink data cached on the second terminal device side.

[0270] Figure 5 A schematic flowchart of another communication method 500 provided in an embodiment of the present application.

[0271] like Figure 5As shown, the communication method 500 includes S501a, S501b, S502 and S503. S501a, S501b, S502 and S503 are described in detail below.

[0272] S501a, the access network device sends a first response message to the second terminal device. Correspondingly, the second terminal device receives the first response message from the access network device.

[0273] The first response message is used to indicate the second identifier and the second key.

[0274] The second key can be understood as: after the first terminal device and the access network device are reestablished, the access network device and the first terminal device communicate with each other using a key, and the second key is used to decrypt data transmitted after the first terminal device and the access network device reestablish a connection. For example, the first response message includes a next hop chaining count (NCC) parameter, and the first terminal device determines the second key based on the NCC parameter.

[0275] The second identifier can be understood as: a local identifier after re-establishment that is allocated by the access network device to the first terminal device during the process of re-establishing a connection between the access network device and the first terminal device.

[0276] Exemplarily, the first response message may be an RRCReestablishment message.

[0277] S501b, the second terminal device sends a first response message to the first terminal device. Correspondingly, the first terminal device receives the first response message from the second terminal device.

[0278] In some embodiments, after receiving the first response message, the second terminal device does not process the content of the first response message, but forwards the first response message carrying the SRAP header to the first terminal device.

[0279] After receiving the first response message, the first terminal device maintains two local identifiers according to the first response message, that is, the first terminal device maintains the first identifier and the second identifier. The first terminal device maintains two keys according to the second response message, that is, the first terminal device maintains the first key and the second key.

[0280] It should be understood that, since the first response message includes the second identifier and the second key, the first terminal device assumes that there is an association relationship between the second identifier and the second key.

[0281] S501b, the second terminal device sends the first information to the first terminal device. Correspondingly, the first terminal device receives the first information from the second terminal device.

[0282] The first information includes first data and a first identifier, and the first data is encrypted using a first key. The first identifier is an identifier of a first terminal device, and the first identifier is used for a sidelink relay adaptation layer.

[0283] Here, the first key can be understood as: the key used by the access network device to communicate with the first terminal device before the first terminal device initiates re-establishment.

[0284] The first identifier can be understood as: a local identifier allocated by the access network device to the first terminal device before the first terminal device initiates re-establishment.

[0285] S503: The first terminal device uses the first key to process the first data.

[0286] The first key is configured by the access network device for the first terminal device before S501 and notified to the first terminal device. In addition, the first key is associated with the first identifier.

[0287] In one example, S503 includes: decrypting the first data or discarding the first data according to the first identifier. In other words, the first terminal device first obtains the first identifier according to the first information described in S501. Then, the first terminal device knows that the first data is encrypted using the first key, and directly decrypts the first data or discards the first data.

[0288] In another example, S503 includes: determining that the first data is encrypted using the first key according to the first identifier; decrypting the first data or discarding the first data. In other words, first, the first terminal device obtains the first identifier according to the first information described in S501. Secondly, the first terminal device determines that the key used to encrypt the first data is the first key according to the first identifier. Finally, the first terminal device directly decrypts the first data or discards the first data according to the first key.

[0289] Through communication method 500, the first terminal device maintains local identifiers of two first terminal devices. After the first terminal device receives the first information carrying the first data, it processes the first data according to the first identifier in the first information using the first key associated with the first identifier. In this way, the first terminal device can avoid decoding erroneous data packets.

[0290] Figure 6 A schematic flowchart of another communication method 600 provided in an embodiment of the present application.

[0291] Optionally, in some embodiments, Figure 6As shown, in addition to S501 to S503, the communication method 600 may also include S301, S302, S303a, S303b, S305a, S305b, S504, S401 to S405. Among them, S501b is executed before S502, S504 is executed after S305a, and S301, S302, and S401 are optional steps. S504, S505, S506a, and S506b of the communication method 600 are described in detail below. For other steps, please refer to the above description and will not be repeated here.

[0292] S504: The first terminal device releases the first identification.

[0293] In some embodiments, when the first terminal device sends the fourth message to the second terminal device, the first terminal device releases the first identifier. In other embodiments, when the second message carrying the first identifier is not received within a preset time, the first terminal device releases the first identifier.

[0294] The embodiment of the present application does not limit the specific value of the preset time. For example, the preset time may be a factory default value of the first terminal device, or the preset time may be a core network configuration, or the preset time may be determined by the first terminal device based on implementation.

[0295] After the first terminal device and the access network device complete the re-establishment, the first terminal device releases the first identifier and stops maintaining the first identifier, thereby reducing the overhead of the first terminal device.

[0296] Figure 7 A schematic flowchart of another communication method 700 provided in an embodiment of the present application.

[0297] like Figure 7 As shown, the communication method 700 includes S701a, S702 to S704, S703 is executed after S701a, and the embodiment of the present application does not limit the execution order of S702 and S701a and whether they are executed simultaneously, nor does it limit the execution order of S702 and S703 and whether they are executed simultaneously. S701a, S702 to S704 are described in detail below.

[0298] S701a, the first terminal device sends a first request message to the second terminal device, the first request message being used to request to reestablish the connection between the first terminal device and the access network device. Correspondingly, the second terminal device receives the first request message from the first terminal device.

[0299] For the description of 701a, please refer to the description of S303a above, which will not be repeated here.

[0300] S702, reconstructing a third entity, where the third entity is used by the first terminal device to send a message to the second terminal device.

[0301] Exemplarily, the third entity may be a SRAP entity.

[0302] S703: The second terminal device sends the first information to the first terminal device. Correspondingly, the first terminal device receives the first information from the second terminal device.

[0303] For the description of S703, reference may be made to the description of S501b above, which will not be repeated here.

[0304] S704: The first terminal device stops processing the first data.

[0305] In one example, the first terminal device stopping processing the first data can be understood as the first terminal device caching the first data, or the first terminal device temporarily storing the first data, or the protocol entity of the first terminal device stopping submitting the first data to the upper layer entity.

[0306] In some embodiments, the first terminal device includes a third entity and a fourth entity, the fourth entity is a wireless link control entity, and stopping processing the first data includes: the fourth entity stops submitting the first data to the third entity, or the fourth entity discards the first data.

[0307] Optionally, in some embodiments, before the fourth entity stops delivering the first data to the third entity, the third entity may instruct the fourth entity to stop delivering the first data to the third entity.

[0308] Optionally, in some embodiments, before S704, the first terminal device does not receive the corresponding SRAP configuration of the access network device or the local identifier of the first terminal device after re-establishment, such as the second identifier.

[0309] Through method 700, after the first terminal device sends a request to the access network device through the second terminal device to re-establish the connection between the first terminal device and the access network device, the first terminal device re-establishes the third entity by itself. However, since the first terminal device does not re-establish the configuration corresponding to the third entity or the first terminal device does not receive an instruction from the access network device to establish the configuration corresponding to the third entity, after the first terminal device receives the first information, it stops processing the first data, which can prevent the first terminal device from decoding an erroneous data packet.

[0310] Figure 8 A schematic flowchart of another communication method 800 provided in an embodiment of the present application.

[0311] Optionally, in some embodiments, Figure 8As shown, in addition to S701a, S702 to S704, the communication method 800 may also include S301, S302, S501a, S501b, S305a, S305b, S401 to S405, S705 to S708. Among them, S501b is executed after S703, S705 to S708 are executed after S402, S706 is executed before S403, and S301, S302, and S401 are optional steps. S705 to S708 are described below, and other steps can refer to the above description, which will not be repeated here.

[0312] S705, the second terminal device reconstructs the fifth entity, and the fifth entity is used by the second terminal device to forward the message transmitted between the first terminal device and the access network device.

[0313] Exemplarily, the fifth entity may be a SRAP entity.

[0314] S706, the first terminal device sends third information to the second terminal device, the third information includes second data and the first identifier, and the second data is encrypted using the first key. Correspondingly, the second terminal device receives the third information from the first terminal device.

[0315] For the first identifier, please refer to the relevant description in S501b above, which will not be repeated here.

[0316] S707: The second terminal device stops processing the second data.

[0317] In one example, the second terminal device stopping processing the second data can be understood as the second terminal device caching the second data, or the second terminal device temporarily storing the second data, or the protocol entity of the second terminal device stopping submitting the second data to the upper layer entity.

[0318] In some embodiments, the first terminal device includes a fifth entity and a sixth entity, the fifth entity is a wireless link control entity, and stopping processing the first data includes: the sixth entity stops submitting the second data to the fifth entity, or the fifth entity discards the second data.

[0319] Optionally, in some embodiments, before the sixth entity stops delivering the second data to the fifth entity, the fifth entity may instruct the sixth entity to stop delivering the second data to the fifth entity.

[0320] Optionally, in some embodiments, before S707, the second terminal device does not receive the corresponding SRAP configuration of the access network device or the local identifier of the re-established first terminal device, such as the second identifier.

[0321] It should be noted that, in some embodiments, S401, S705 to S708 can be implemented independently of the communication method 800. In this embodiment, S401 and S708 are optional steps. In this embodiment, after the second terminal device sends a request to the access network device to re-establish the connection between the second terminal device and the access network device, the second terminal device re-establishes the fifth entity by itself. However, since the second terminal device has not re-established the configuration corresponding to the fifth entity or the second terminal device has not received the access network device's instruction to establish the configuration corresponding to the fifth entity, the second terminal device stops processing the second data after receiving the third information. Furthermore, after the second terminal device and the access network device are reestablished, the access network device will not receive the data packet encrypted with the first key forwarded by the second terminal device, so that the access network device will not decrypt erroneous data.

[0322] Fig. 9 A schematic flowchart of another communication method 900 provided in an embodiment of the present application.

[0323] like Fig. 9 As shown, the communication method 900 includes S901a, S902, S903 and S904, and S901a, S902, S903a and S904 are executed in sequence. S901a, S902, S903a and S904 are described in detail below.

[0324] S901a, the access network device sends a sixth message to the second terminal device, where the sixth message is used to indicate the second identifier and the second key.

[0325] Exemplarily, the sixth message may be an RRC Recongfiguration message.

[0326] For the description of the second identifier, please refer to the description of S501a above, and for the description of the second key, please refer to the description of S405 above, which will not be repeated here.

[0327] S902, the first terminal device sends third information to the second terminal device, the third information including the second data and the first identifier. Correspondingly, the second terminal device receives the third information from the first terminal device.

[0328] The second data is encrypted using the first key.

[0329] S903: The second terminal device forwards the third information to the access network device according to the first identifier and the second identifier. Correspondingly, the access network device receives the third information from the second terminal device.

[0330] The first identifier is configured by the access network device for the first terminal device before S901a and is notified to the first terminal device.

[0331] S904: The access network device uses the first key to process the second data.

[0332] In one example, S904 includes: decrypting the second data or discarding the second data according to the first identifier. In other words, the access network device first obtains the first identifier according to the third information. Then, the access network device knows that the second data is encrypted with the first key, and directly decrypts the second data or discards the second data.

[0333] In another example, S904 includes: determining that the second data is encrypted with the first key according to the first identifier; decrypting the second data or discarding the second data. In other words, first, the access network device obtains the first identifier according to the third information. Secondly, the access network device determines that the key for encrypting the second data is the first key according to the first identifier. Finally, the access network device directly decrypts the second data or discards the second data according to the first key.

[0334] In method 900, the access network device maintains local identifiers of two first terminal devices. After receiving the third information carrying the second data, the access network device processes the second data based on the first identifier in the third information using the first key associated with the first identifier. In this way, the access network device can avoid decoding erroneous data packets.

[0335] Fig.10 A schematic flowchart of another communication method 1000 provided in an embodiment of the present application.

[0336] Optionally, in some embodiments, Fig.10 As shown, in addition to S901a, S902, S903 and S904, the communication method 1000 may also include S301, S302, S303a, S303b, S501a, S501b, S305a, S305b, S504, S401 to S404, S905. Among them, S901a, S902, S903 and S904 are executed after S401, and S301, S302, S401, S504, S905 are optional steps. S905 of the communication method 1000 is described in detail below, and other steps can refer to the above description, which will not be repeated here.

[0337] S905: The second terminal device releases the first identifier.

[0338] In some embodiments, when the second terminal device forwards the third information to the access network device, the second terminal device releases the first identifier. After the second terminal device forwards the third information to the access network device, the second terminal device releases the first identifier and stops maintaining the first identifier, thereby reducing the overhead of the second terminal device.

[0339] In some other embodiments, when the fourth information carrying the first identifier is not received within a preset time, the second terminal device releases the first identifier. After the second terminal device forwards the third information to the access network device, if the fourth information carrying the first identifier is not received within a preset time, the second terminal device automatically releases the first identifier and automatically stops maintaining the first identifier, thereby reducing the overhead of the second terminal device.

[0340] The embodiment of the present application does not limit the specific value of the preset time. For example, the preset time may be factory-installed by the second terminal device, or the preset time may be configured by the core network, or the preset time may be determined by the second terminal device based on implementation.

[0341] It should be noted that, when the access network equipment includes CU and DU, Figures 3 to 10 The action of the access network device sending and receiving messages from the second terminal device is performed by the DU. When the DU receives the message sent by the second terminal device, it forwards it to the CU, and the CU performs the processing action according to the content of the message. When the DU sends a message to the second terminal device, the CU first generates the message and forwards the message to the DU, and the DU then forwards it to the second terminal device. In addition, the CU can also be used to perform message or data processing actions.

[0342] For example, in S402 described above, the second terminal device sending the second request message to the access network device specifically includes the second terminal device sending the second request message to the DU of the access network device. The access network device receiving the second request message from the second terminal device includes the DU of the access network device receiving the second request message from the second terminal device. The specific processes of S404, S303b, S305b, S306b, S306b, and S903 described above are similar to the specific processes of S402 and are not repeated here.

[0343] For another example, in S403 described above, the access network device sending a second response message to the second terminal device specifically includes: the CU of the access network device generates a second response message, sends the second response message to the DU of the access network device, and the DU of the access network device then forwards the second response message to the second terminal device. The second terminal device receiving the second response message sent from the access network device specifically includes the second terminal device receiving the second response message sent from the DU of the access network device. The specific processes of S405, S304a, S306a, S501a, and S901a described above are similar to the specific process of S403 and will not be repeated here.

[0344] For example, in S904 described above, the access network device using the first key to process the second data specifically includes: the CU using the first key to process the second data.

[0345] After the first terminal device and the second terminal device trigger the re-establishment, before the first terminal device sends a re-establishment request message to the second terminal device, there will be a misalignment in the RLC sequence numbers (serial number, SN) of the first terminal device and the second terminal device. In this way, the second terminal device cannot correctly receive the re-establishment request message and the re-establishment completion message of the first terminal device.

[0346] In view of this, the present application also provides the following embodiments: Fig.11 The communication method 1100 shown below is combined with Fig.11 The communication method 1100 is described in detail.

[0347] Fig.11 A schematic flowchart of another communication method 1100 provided in an embodiment of the present application.

[0348] like Fig.11 As shown, the communication method 1100 includes S1101 to S1103. S1101 to S1103 are described in detail below.

[0349] S1101, the second terminal device initiates re-establishment between the second terminal device and the access network device.

[0350] In one example, when the second terminal device detects that RLF occurs on the Uu interface between the second terminal device and the access network device, the second terminal device executes S1101. In another example, when the second terminal device sends a first message to the first terminal device, the second terminal device executes S1101. For the first message, refer to the description of S301 above, which will not be repeated here.

[0351] It should be understood that the second terminal device initiating the re-establishment between the second terminal device and the access network device can be understood as the second terminal device initiating the re-establishment process between the second terminal device and the access network device.

[0352] S1102, releasing the first entity and the second entity.

[0353] Exemplarily, the first entity and the second entity are RLC entities.

[0354] The first entity is used to receive or send a message carried by the first signaling radio bearer of the first terminal device (referred to as the first signaling radio bearer message), and the second entity is used to receive or send a message carried by the second signaling radio bearer of the first terminal device (referred to as the second signaling radio bearer message). The first signaling radio bearer is used to carry the first request message, and the second signaling radio bearer is used to carry the fourth message. Among them, the first request message is used to request to re-establish the connection between the first terminal device and the access network device, and the fourth message is used to indicate that the connection between the first terminal device and the access network device has been reestablished. In this way, the first entity is used for the second terminal device to receive the first request message from the first terminal device or send the first request message of the first terminal device to the access network device, and the second entity is used for the second terminal device to receive the fourth message from the first terminal device or send the fourth message of the first terminal device to the access network device.

[0355] For example, the first signaling radio bearer is SRB0 of the first terminal device, and the first entity is an RLC entity for receiving or sending SRB0 messages of the first terminal device. The second radio bearer is SRB1 of the first terminal device, and the second entity is an RLC entity for receiving or sending SRB1 messages of the first terminal device.

[0356] S1103: Apply the first predefined configuration to the third entity, and apply the second predefined configuration to the fourth entity.

[0357] The third entity is used for the second terminal device to receive a first request message from the first terminal device, and the fourth entity is used for the second terminal device to receive a fourth message from the first terminal device.

[0358] Exemplarily, the third entity and the fourth entity are RLC entities.

[0359] Applying the first predefined configuration to the third entity can be understood as reestablishing the RLC entity corresponding to SL-RLC0. The PC5 relay RLC channel to which the first predefined configuration is applied is called SL-RLC0.

[0360] In one example, applying the first predefined configuration to the third entity includes establishing a fifth entity and applying the specified configuration of SL-RLC0 to obtain the third entity. In another example, applying the first predefined configuration to the third entity includes establishing the fifth entity according to the specified configuration of SL-RLC0 to obtain the fourth entity.

[0361] Applying the second predefined configuration to the fourth entity can be understood as reestablishing the RLC entity corresponding to SL-RLC1. The PC5 relay RLC channel to which the second predefined configuration is applied is called SL-RLC1.

[0362] In one example, applying the second predefined configuration to the fourth entity includes establishing a sixth entity and applying the default configuration of SL-RLC1. In another example, applying the second predefined configuration to the fourth entity includes establishing the fourth entity according to the default configuration of SL-RLC1.

[0363] Optionally, in some embodiments, when the first terminal device receives the first message from the second terminal device, the first terminal device releases the RLC entity corresponding to the first radio bearer and the RLC entity corresponding to the second radio bearer, and reestablishes the RLC entities corresponding to SL-RLC0 and SL-RLC1, and then initiates the triggering RRC reestablishment process.

[0364] Through method 1100, after the second terminal device initiates the re-establishment process between the second terminal device and the access network device, the second terminal device releases the PC5 RLC entity of the second terminal device corresponding to the message carried by the first signaling radio bearer for receiving or sending the first terminal device and the PC5 RLC entity corresponding to the message carried by the second signaling radio bearer for receiving or sending the first terminal device, and re-establishes the RLC entity for receiving or sending the message carried by the first signaling radio bearer for receiving or sending the first terminal device and the RLC entity for receiving or sending the message carried by the second signaling radio bearer for receiving or sending the first terminal device. In this way, the first terminal device sends the first request message and the fourth message to the access network device through the second terminal device, and the RLC SNs of the first terminal device and the second terminal device both start from 0. Therefore, the second terminal device can correctly receive the first request message and the fourth message, and then forward them to the access network device, ensuring that the RRC re-establishment process of the first terminal device proceeds normally.

[0365] It should be noted that Figure 3 The communication method 300 and Figures 5 to 10 The communication methods shown in any of the figures may be implemented in combination or individually, and the embodiments of the present application are not limited to this. Figure 4 The communication method 400 and Figures 5 to 10 The communication methods shown in any of the figures may be implemented in combination or individually, and the embodiments of the present application are not limited to this. Figures 3 to 10 The communication method shown in any one of the figures and Fig.11 The communication method 1100 shown can be implemented in combination or can be implemented separately, and this embodiment of the present application does not limit this. In addition, the communication method 1100 is also applicable to the O-RAN system.

[0366] Above, combined Figures 3 to 11 The communication method provided by the embodiment of the present application is described in detail. Fig.12 and Fig.13The device provided in the embodiments of the present application is described in detail.

[0367] Fig.12 This is a schematic block diagram of an example of a communication device provided in an embodiment of the present application. Fig.12 As shown, the communication device 1200 includes a transceiver unit 1210 and a processing unit 1220. The transceiver unit 1210 can implement corresponding communication functions, and the processing unit 1220 is used to perform data processing so that the communication device implements the aforementioned method embodiment. The transceiver unit 1210 can also be called a communication interface or a communication unit.

[0368] Optionally, the communication device 1200 may further include a storage unit, which may be used to store instructions and / or data, and the processing unit 1220 may read the instructions and / or data in the storage unit so that the communication device implements the aforementioned method embodiment.

[0369] The communication device 1200 can be used to execute the actions performed by the first terminal device in the above method embodiment. In this case, the communication device 1200 can be the first terminal device, or a component that can be configured on the first terminal device. The transceiver unit 1210 is used to execute the transceiver-related operations on the first terminal device side in the above method embodiment. The storage unit is used to execute the data or instruction storage-related operations on the first terminal device side in the above method embodiment. The processing unit 1220 is used to execute the processing-related operations on the first terminal device side in the above method embodiment.

[0370] Alternatively, the communication device 1200 can be used to execute the actions performed by the second terminal device in the above method embodiment. In this case, the communication device 1200 can be a second terminal device, or a component that can be configured on the second terminal device. The transceiver unit 1210 is used to execute the transceiver-related operations on the second terminal device side in the above method embodiment, the storage unit is used to execute the data or instruction storage-related operations on the second terminal device side in the above method embodiment, and the processing unit 1220 is used to execute the processing-related operations on the second terminal device side in the above method embodiment.

[0371] Alternatively, the communication device 1200 can be used to execute the actions performed by the access network device in the above method embodiment. In this case, the communication device 1200 can be an access network device, or a component that can be configured on the access network device. The transceiver unit 1210 is used to execute the transceiver-related operations on the access network device side in the above method embodiment. The storage unit is used to execute the data or instruction storage-related operations on the access network device side in the above method embodiment. The processing unit 1220 is used to execute the processing-related operations on the access network device side in the above method embodiment.

[0372] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0373] The processing unit 1220 in the above embodiment may be implemented by at least one processor or processor-related circuit. The transceiver unit 1210 may be implemented by a transceiver or a transceiver-related circuit. The transceiver unit 1210 may also be referred to as a communication unit or a communication interface. The storage unit may be implemented by at least one memory.

[0374] Fig.13 A schematic block diagram of another example of a communication device 1300 provided in an embodiment of the present application. As shown in the figure, the device 1300 includes: at least one processor 1310 and a transceiver 1320. The processor 1310 is coupled to the memory and is used to execute instructions stored in the memory to send signals and / or receive signals. Optionally, the device 1300 also includes a memory 1330 for storing instructions. Optionally, the device 1300 also includes a transceiver 1320, and the processor 1310 controls the transceiver 1320 to send signals and / or receive signals.

[0375] It should be understood that the processor 1310 and the memory 1330 may be combined into one processing device, and the processor 1310 is used to execute the program code stored in the memory 1330 to implement the above functions. In specific implementation, the memory 1330 may also be integrated into the processor 1310 or independent of the processor 1310.

[0376] It should also be understood that the transceiver 1320 may include a transceiver (or receiver) and a transmitter (or transmitter). The transceiver may further include an antenna, and the number of antennas may be one or more. The transceiver 1320 may also be a communication interface or an interface circuit.

[0377] For example, the transceiver 1320 in the device 1300 may correspond to the transceiver unit in the above embodiment, and the processor 1310 in the device 1300 may correspond to the processing unit in the above embodiment. It should be understood that the specific process of each transceiver processor performing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0378] Fig.14 The schematic block diagram of a chip system 1400 provided in an embodiment of the present application is as follows. The chip system 1400 (or also referred to as a processing system) includes a logic circuit 1410 and an input / output interface 1420 .

[0379] Among them, the logic circuit 1410 can be a processing circuit in the chip system 1400. The logic circuit 1410 can be coupled to the storage unit and call the instructions in the storage unit so that the chip system 1400 can implement the methods and functions of each embodiment of the present application. The input / output interface 1420 can be an input / output circuit in the chip system 1400, outputting information processed by the chip system 1400, or inputting data or signaling information to be processed into the chip system 1400 for processing.

[0380] As a solution, the chip system 1400 is used to implement the operations performed by the first terminal device in each of the above method embodiments.

[0381] For example, the logic circuit 1410 is used to implement the processing-related operations performed by the terminal device in the above method embodiment; the input / output interface 1420 is used to implement the sending and / or receiving-related operations performed by the first terminal device in the above method embodiment.

[0382] As another solution, the chip system 1400 is used to implement the operations performed by the second terminal device in the above method embodiments.

[0383] For example, the logic circuit 1410 is used to implement the processing-related operations performed by the second terminal device in the above method embodiment; the input / output interface 1420 is used to implement the sending and / or receiving-related operations performed by the second terminal device in the above method embodiment.

[0384] As another solution, the chip system 1400 is used to implement the operations performed by the access network device in the above method embodiments.

[0385] For example, the logic circuit 1410 is used to implement the processing-related operations performed by the access network device in the above method embodiment; the input / output interface 1420 is used to implement the sending and / or receiving-related operations performed by the access network device in the above method embodiment.

[0386] An embodiment of the present application also provides a computer-readable storage medium on which computer instructions are stored for implementing the methods executed by a communication device (such as a first terminal device, a second terminal device, or an access network device) in the above-mentioned method embodiments.

[0387] An embodiment of the present application also provides a computer program product, comprising instructions, which, when executed by a computer, implement the methods performed by a communication device (such as a first terminal device, a second terminal device, or an access network device) in the above-mentioned method embodiments.

[0388] An embodiment of the present application also provides a communication system, which includes the first terminal device, the second terminal device and the access network device in the above embodiments.

[0389] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0390] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the above units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0391] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to implement the solution provided by this application.

[0392] In addition, each functional unit in each embodiment of the present application may be integrated into one unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0393] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0394] When software is used for implementation, 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 loading and executing computer program instructions on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instruction can be stored in a computer-readable storage medium, or transmitted from a computer-readable storage medium to another computer-readable storage medium, for example, the computer instruction can be transmitted from a website site, a computer, a server or a data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. About computer-readable storage medium, it can be described with reference to the above.

[0395] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A communication method, characterized in that: The communication method is applied to a first terminal device, the first terminal device communicates with an access network device through a second terminal device, and the communication method includes: receiving a first message from the second terminal device, where the first message is used to indicate that a wireless link failure occurs between the second terminal device and the access network device; Stop sending data to the second terminal device, where the data includes data sent by the first terminal device to the access network device through the second terminal device.

2. The communication method according to claim 1, characterized in that: The method further comprises: A first request message is sent to the second terminal device, where the first request message is used to request to re-establish a connection between the first terminal device and the access network device.

3. The communication method according to claim 1 or 2, characterized in that: The method further comprises: When the first condition is met, releasing the first entity; The first entity is used by the first terminal device to send a message to the second terminal device; The first condition includes that the first terminal device receives the first message or the first terminal device sends a first request message.

4. The communication method according to any one of claims 1 to 3, characterized in that: The communication method further comprises: When the second condition is met, releasing the first configuration; Wherein, the first configuration is used for the first terminal device to receive a message from the second terminal device; The second condition includes that the first terminal device receives the first message or the first terminal device sends a first request message.

5. The communication method according to any one of claims 1 to 4, characterized in that: The communication method further comprises: receiving a second message from the access network device, the second message being used to indicate one or more added or modified radio link control channel configurations; Release the radio link control channel configuration between the first terminal device and the second terminal device.

6. A communication method, characterized in that: The communication method is applied to a second terminal device, the second terminal device is used to provide a relay service for communication between the first terminal device and the access network device, and the communication method includes: Sending a first message to the first terminal device, where the first message is used to indicate that a wireless link failure occurs between the second terminal device and the access network device; Stop sending data to the first terminal device, where the data includes data sent by the access network device to the first terminal device through the second terminal device.

7. The communication method according to claim 6, characterized in that: The communication method further comprises: A second request message is sent to the access network device, where the second request message is used to request to re-establish a connection between the second terminal device and the access network device.

8. The communication method according to claim 6 or 7, characterized in that: The communication method further comprises: When the third condition is met, releasing the second entity; The second entity is used by the second terminal device to send a message to the first terminal device; The third condition includes one of the following: the second terminal device detects that a wireless link failure occurs between the second terminal device and the access network device; the second terminal device sends the first message; the second terminal device sends a second request message.

9. The communication method according to any one of claims 6 to 8, characterized in that: The communication method further comprises: When the fourth condition is met, releasing the second configuration; The second configuration is used for the second terminal device to receive a message from the first terminal device; The fourth condition includes one of the following: the second terminal device detects that a wireless link failure occurs between the second terminal device and the access network device; the second terminal device sends the first message; the second terminal device sends a second request message.

10. The communication method according to any one of claims 6 to 9, characterized in that: The communication method further comprises: receiving a third message from the access network device, the third message being used to indicate one or more added or modified radio link control channel configurations; Release the radio link control channel configuration between the first terminal device and the second terminal device.

11. A communication method, characterized in that: The communication method is applied to a first terminal device, the first terminal device communicates with an access network device through a second terminal device, and the communication method includes: Receiving a first response message from the access network device, where the first response message is used to indicate a second identifier and a second key; Receive first information from a second terminal device, where the first information includes first data and a first identifier, where the first data is encrypted using a first key, where the first identifier is an identifier of the first terminal device, and where the first identifier is used for a sidelink relay adaptation layer; The first data is processed using the first key.

12. The communication method according to claim 11, characterized in that: The using the first key to process the first data comprises: The first data is decrypted or discarded according to the first identifier.

13. The communication method according to claim 12, characterized in that: The decrypting the first data or discarding the first data according to the first identifier includes: Determining, according to the first identifier, that the first data is encrypted using the first key; The first data is decrypted or discarded.

14. The communication method according to any one of claims 11 to 13, characterized in that: The communication method further comprises: Stop sending data to the second terminal device, where the data includes data sent by the first terminal device to the access network device through the second terminal device.

15. The communication method according to any one of claims 11 to 14, characterized in that: The communication method further comprises: Sending a fourth message to the access network device, where the fourth message is used to indicate that the connection between the first terminal device and the access network device has been reestablished; Release the first identifier.

16. The communication method according to claim 15, characterized in that: The releasing the first local identifier comprises: If the second information carrying the first identifier is not received within a preset time, the first identifier is released.

17. A communication method, characterized in that: The communication method is applied to a first terminal device, the first terminal device communicates with an access network device through a second terminal device, and the communication method includes: Sending a first request message to the second terminal device, where the first request message is used to request to re-establish a connection between the first terminal device and the access network device; Rebuilding a third entity, where the third entity is used by the first terminal device to send a message to the second terminal device; Receive first information from the second terminal device, where the first information includes first data and a first identifier, where the first data is encrypted using a first key, where the first identifier is an identifier of the first terminal device, and where the first identifier is used for a sidelink relay adaptation layer; Stop processing the first data.

18. The communication method according to claim 17, characterized in that: The first terminal device includes the third entity and the fourth entity, the fourth entity is a radio link control entity, and the stopping of processing the first data includes: The fourth entity stops submitting the first data to the third entity, or the fourth entity discards the first data.

19. The communication method according to claim 17 or 18, characterized in that: The communication method further comprises: Stop sending data to the second terminal device, where the data includes data sent by the first terminal device to the access network device through the second terminal device.

20. A communication method, characterized in that: The communication method is applied to a second terminal device, the second terminal device is used to provide a relay service for communication between the first terminal device and the access network device, and the communication method includes: Sending a second request message to the access network device, where the second request message is used to request to re-establish a connection between the second terminal device and the access network device; Rebuilding a fifth entity, where the fifth entity is used by the second terminal device to forward messages transmitted between the first terminal device and the access network device; Receive third information from the first terminal device, the third information including second data and a first identifier, the second data is encrypted using a first key, the first identifier is an identifier of the first terminal device, and the first identifier is used for a sidelink relay adaptation layer; Stop processing the second data.

21. The communication method according to claim 20, characterized in that: The second terminal device includes the fifth entity and the sixth entity, the sixth entity is a radio link control entity, and the stopping of processing the second data includes: The sixth entity stops submitting the second data to the fifth entity, or the sixth entity discards the second data.

22. The communication method according to claim 20 or 21, characterized in that: The communication method further comprises: Stop sending data to the first terminal device, where the data includes data sent by the access network device to the first terminal device through the second terminal device.

23. A communication method, characterized in that: The communication method is applied to an access network device, and the communication method includes: Sending a sixth message to the second terminal device, where the sixth message is used to indicate the second identifier and the second key; receiving third information from a second terminal device, the third information including second data and a first identifier, the second data being encrypted using a first key, the second terminal device being used to provide a relay service for communication between the first terminal device and the access network device; Processing the second data using the first key; The first identifier and the second identifier are identifiers of the first terminal device, and the first identifier and the second identifier are used for the sidelink relay adaptation layer.

24. The communication method according to claim 23, characterized in that: The using the first key to process the second data comprises: According to the first identifier, the second data is decrypted or discarded.

25. The communication method according to claim 24, characterized in that: The decrypting the second data or discarding the second data according to the first identifier includes: determining, according to the first identifier, that the second data is encrypted using the first key; The second data is decrypted or discarded.

26. A communication method, characterized in that: The communication method is applied to a second terminal device, the second terminal device is used to provide a relay service for communication between the first terminal device and the access network device, and the communication method includes: Initiate re-establishment between the second terminal device and the access network device; releasing the first entity and the second entity; applying the first predefined configuration to the third entity; applying the second predefined configuration to the fourth entity; Among them, the first entity and the third entity are used for the second terminal device to receive a first request message from the first terminal device, the second entity and the fourth entity are used for the second terminal device to receive a fourth message from the first terminal device, the first request message is used to request to re-establish the connection between the first terminal device and the access network device, and the fourth message is used to indicate that the connection between the first terminal device and the access network device has been re-established.

27. A communication device, characterized in that: The communication device comprises means for executing the communication method according to any one of claims 1 to 26.

28. A communication device, characterized in that: The device comprises at least one processor coupled to at least one memory, wherein the at least one processor is used to execute a computer program or instruction stored in the at least one memory so that the communication device executes the communication method according to any one of claims 1 to 26.

29. A chip, characterized in that: It includes at least one processor and a communication interface, wherein the communication interface is used to receive data and / or information and transmit the received data and / or information to the processor, and the processor processes the data and / or information to execute the communication method as described in any one of claims 1 to 26.

30. A computer-readable storage medium, characterized in that: Used to store a computer program, the computer program comprising instructions for implementing the communication method according to any one of claims 1 to 26.

31. A communication system, characterized in that: The communication system includes a first terminal device, a second terminal device and an access network device; Wherein, the first terminal device is used to execute the communication method according to any one of claims 1 to 5, or, the first terminal device is used to execute the communication method according to any one of claims 11 to 19; or, The second terminal device is used to execute the communication method according to any one of claims 6 to 10, or the second terminal device is used to execute the communication method according to any one of claims 20 to 22, or the second terminal device is used to execute the communication method according to claim 26; or The access network device is used to execute the communication method as described in any one of claims 23 to 25.

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