Communication method, device and communication system

Abstract

The invention provides a communication method, a communication device and a communication system, which are used for enabling network equipment to configure relay terminal equipment for first terminal equipment so as to ensure that data of emergency service can be normally transmitted. In the method, a first terminal device sends a first message to a network device, the first message comprising at least one first identifier, the first identifier being an identifier used by a second terminal device for providing a relay service for an emergency service, the first message further comprising an indication field of the first identifier, the indication field of the first identifier can be used for indicating that the second terminal equipment supports the emergency service; and receiving one of the at least one first identifier from the network device, and establishing a first connection with a target terminal device corresponding to the one first identifier, the first connection being used for transmitting data of an emergency service.

Description

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on August 23, 2023, with application number 202311071394.5 and application name “A communication method, device and communication system”, the entire contents of which are incorporated by reference in this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a communication method, device and communication system. Background Art

[0003] User equipment to network relay (U2N relay) is a technology that allows a user equipment (UE) to help another UE communicate with a base station. It is also called relay technology. In the U2N relay communication scenario, the remote UE communicates with the base station through the cooperation of the relay UE. The remote UE and the relay UE communicate through a sidelink, whose interface is called the PC5 interface. The relay UE communicates directly with the base station, that is, through the Uu interface. Figure 1 shown.

[0004] The current protocol stipulates that in the U2N relay communication scenario, the remote UE and relay UE have a dedicated relay service code (RSC) for emergency services (also called emergency services). The relay service code is used to discover and establish a PC5 connection, and the PC5 connection associated with the RSC for emergency services is only used to transmit data for the emergency services. The relay UE will only indicate to the remote UE that it supports emergency services during the discovery process. So when the remote UE has emergency service data to be transmitted, how to achieve the transmission of the emergency service data is a problem that needs to be solved. Summary of the invention

[0005] The present application provides a communication method, an apparatus and a communication system for enabling a network device to configure a relay UE for a remote UE to ensure that data of an emergency service can be transmitted normally.

[0006] In a first aspect, the present application provides a communication method, which can be applied to a first terminal device, or a component (such as a processor, chip, chip system, circuit or other, etc.) configured in the first terminal device, or a software module. The method may include: the first terminal device sends a first message to a network device, the first message includes at least one first identifier, the first identifier is an identifier of a second terminal device for providing relay services for emergency services, the first message also includes an indication field of the first identifier, the indication field of the first identifier is used to indicate that the second terminal device supports the emergency service; receiving a first identifier from the at least one first identifier of the network device; and establishing a first connection between a target terminal device corresponding to the one first identifier, the first connection is used to transmit data of the emergency service.

[0007] Based on the above communication method, the first terminal device sends the first message to the network device, so that the network device can configure a relay terminal device supporting emergency services for the first terminal device based on the first message, thereby ensuring that the data of the emergency service can be transmitted normally.

[0008] In a possible implementation, the value of the indication field of the first identifier includes a first value and a second value, and the value of the indication field of the first identifier is the first value, wherein the first value is used to indicate that the second terminal device supports the emergency service, and the second value is used to indicate that the second terminal device supports non-emergency service.

[0009] Based on the above implementation method, the first terminal device can indicate that the second terminal device supports emergency services by carrying the indication field of the first identifier in the first message, or can also indicate that the second terminal device supports emergency services by the value of the indication field of the first identifier. The implementation method is flexible.

[0010] In a possible implementation, the first message also includes at least one second identifier, and the second identifier is an identifier of the third terminal device for providing relay services for non-emergency services. Furthermore, the first message does not include an indication field of the second identifier, and the first message is used to indicate that the third terminal device supports the non-emergency service; or, the first message also includes an indication field of the second identifier, and the value of the indication field of the second identifier includes a first value and a second value, and the value of the indication field of the second identifier is the second value, wherein the first value is used to indicate that the third terminal device supports the emergency service, and the second value is used to indicate that the third terminal device supports the non-emergency service. Optionally, a third terminal device and a second terminal device may be the same terminal device.

[0011] Based on the above implementation, the first terminal device can send at least one second identifier corresponding to the terminal device supporting non-emergency services to the network device. Furthermore, the first terminal device can indicate that the third terminal device supports non-emergency services by not carrying the indication field of the second identifier in the first message, or can also indicate that the third terminal device supports non-emergency services by taking the value of the indication field of the second identifier, and the implementation method is flexible.

[0012] In a possible implementation, the first terminal device may also send at least one identifier of the first terminal device to the network device, and the at least one identifier includes a third identifier, or includes a third identifier and a fourth identifier, wherein the third identifier is an identifier of the first terminal device used for the emergency service, and the fourth identifier is an identifier of the first terminal device used for non-emergency services.

[0013] Based on the above implementation, the first terminal device sends the third identifier to the network device, so that the network device can configure the corresponding target terminal device according to the service requirements of the first terminal device, thereby ensuring that the service of the first terminal device proceeds normally.

[0014] In a possible implementation manner, the first terminal device may also receive first indication information from the network device, where the first indication information instructs the first terminal device to measure the second terminal device.

[0015] Based on the above implementation, the first terminal device only measures the relay terminal device that supports emergency services in response to the first indication information, which can reduce the measurement complexity and the overhead of reporting the measurement results.

[0016] In a possible implementation, the first terminal device may also send a second indication information to the core network device, the second indication information indicating that a fourth terminal device needs to be switched, the fourth terminal device providing a relay service for the first terminal device; and receive a second message from the network device, the second message being used to request the first terminal device to send the first message. Exemplarily, the second message may be sent by the network device in response to a third indication information from the core network device, the third indication information indicating that a fifth terminal device is configured for the first terminal device, the fifth terminal device supporting the emergency service and having the ability to provide a relay service for the first terminal device.

[0017] In another possible implementation, the first terminal device may also receive a third message from the network device, where the third message includes a trigger condition for sending the first message, and the trigger condition includes data of the emergency service to be transmitted by the first terminal device.

[0018] Based on the above two implementation methods, the first terminal device can send the first message to the network device in response to the second message, or can also send the first message to the network device in response to the trigger condition. The implementation method is flexible.

[0019] In a possible implementation manner, there is a second connection between the target terminal device and the first terminal device, and the second connection is used to transmit data of non-emergency services.

[0020] Based on the above implementation, the target terminal device can provide relay services for the first terminal device, that is, the first terminal device can communicate with the network device through the target terminal device. Further, the first terminal device can retain the second connection, that is, the target terminal device can provide relay services for both emergency services and non-emergency services of the first terminal device, which can improve transmission efficiency.

[0021] In one possible implementation, the first terminal device establishes the first connection with the target terminal device corresponding to the first identifier by: releasing the second connection and establishing the first connection based on the first identifier; or updating the configuration information of the second connection based on the first identifier to obtain the first connection, and stopping transmitting the data of the non-emergency service.

[0022] Based on the above implementation, the first terminal device can establish the first connection in a variety of ways, and the implementation is flexible.

[0023] In one possible implementation, the first terminal device establishes a first connection with a target terminal device corresponding to the first identifier, which may be specifically as follows: the first terminal device sends a ninth message to the target terminal device, and the ninth message is used to request establishment of the first connection, wherein the ninth message includes a relay service code for the emergency service, and the source identifier used to send the ninth message is a third identifier, and the third identifier is an identifier of the first terminal device used for the emergency service.

[0024] Based on the above implementation, the target terminal device determines that the first connection is used for emergency services based on the relay service code.

[0025] In a possible implementation, the first terminal device may also send a tenth message to the target terminal device, and the source identifier used to send the tenth message is the third identifier. Optionally, the tenth message may be sent by the first terminal device in response to the first identifier of the network device.

[0026] In the second aspect, the present application provides a communication method, which can be applied to a network device, or a component (such as a processor, chip, chip system, circuit or other, etc.) configured in the network device, or a software module. The method may include: the network device receives a first message from a first terminal device, the first message includes at least one first identifier, the first identifier is an identifier of the second terminal device for providing relay services for emergency services, and the first message also includes an indication field of the first identifier, the indication field of the first identifier is used to indicate that the second terminal device supports the emergency service; sending a first identifier of the at least one first identifier to the first terminal device, and sending a third identifier to the target terminal device corresponding to the one first identifier, so that the first terminal device establishes a first connection with the target terminal device, the first connection is used to transmit data of the emergency service, and the third identifier is an identifier of the first terminal device used for the emergency service.

[0027] In a possible implementation, the value of the indication field of the first identifier includes a first value and a second value, and the value of the indication field of the first identifier is the first value, wherein the first value is used to indicate that the second terminal device supports the emergency service, and the second value is used to indicate that the second terminal device supports non-emergency service.

[0028] In a possible implementation, the first message also includes at least one second identifier, and the second identifier is an identifier used by the third terminal device to provide relay services for non-emergency services. Furthermore, the first message does not include an indication field of the second identifier, and the first message is used to indicate that the third terminal device supports the non-emergency service; or, the first message also includes an indication field of the second identifier, and the value of the indication field of the second identifier includes a first value and a second value, and the value of the indication field of the second identifier is the second value, wherein the first value is used to indicate that the third terminal device supports the emergency service, and the second value is used to indicate that the third terminal device supports the non-emergency service.

[0029] In a possible implementation, the network device may also receive at least one identifier from the first terminal device, wherein the at least one identifier of the first terminal device includes the third identifier, or includes the third identifier and a fourth identifier, and the fourth identifier is an identifier of the first terminal device used for non-emergency services.

[0030] In one possible implementation, the network device may also receive at least one identifier from a sixth terminal device, wherein the at least one identifier of the sixth terminal device includes a fifth identifier and / or a sixth identifier, the fifth identifier being an identifier of the sixth terminal device used to provide relay service for the emergency service, and the sixth identifier being an identifier of the sixth terminal device used to provide relay service for non-emergency service, wherein if the at least one identifier of the sixth terminal device includes the fifth identifier, the sixth terminal device is the second terminal device.

[0031] Based on the above implementation, the network device may determine that the sixth terminal device providing relay service for the first terminal device supports emergency services, or supports non-emergency services, or supports both emergency services and non-emergency services.

[0032] In a possible implementation manner, the network device may further send first indication information to the first terminal device, where the first indication information instructs the first terminal device to measure the second terminal device.

[0033] In one possible implementation, the network device may also receive a third indication information from the core network device, wherein the third indication information indicates that a fifth terminal device is configured for the first terminal device, wherein the fifth terminal device supports the emergency service and has the ability to provide relay services for the first terminal device; and, according to the third indication information, send a second message to the first terminal device, wherein the second message is used to request the first terminal device to send the first message.

[0034] In a possible implementation manner, the network device may further send a third message to the first terminal device, where the third message includes a triggering condition for sending the first message, and the triggering condition includes the emergency service data to be transmitted by the first terminal device.

[0035] In a possible implementation, the network device may also receive an eleventh message from the target terminal device, the eleventh message being used to request establishment of a third connection, the third connection being a connection between the target terminal device and the network device, the eleventh message including a reason for establishing the third connection, and the reason for establishing the third connection including emergency services.

[0036] In a possible implementation, the network device may also receive a tenth message from the target terminal device. Optionally, the tenth message may be sent by the first terminal device in response to the first identifier of the network device.

[0037] For the technical effects that can be achieved by the above-mentioned second aspect and any possible implementation method thereof, please refer to the technical effects that can be achieved by the above-mentioned first aspect and any possible implementation method thereof, and no further details will be given.

[0038] In a third aspect, the present application further provides a communication method, which can be applied to a sixth terminal device, or a component (such as a processor, a chip, a chip system, a circuit or other, etc.) configured in the sixth terminal device, or a software module. The method may include: the sixth terminal device sends at least one identifier to the network device, the at least one identifier includes a fifth identifier and / or a sixth identifier, the fifth identifier is an identifier of the sixth terminal device for providing a relay service for an emergency service, and the sixth identifier is an identifier of the sixth terminal device for providing a relay service for a non-emergency service.

[0039] In one possible implementation, the at least one identifier includes the fifth identifier, and the sixth terminal device can also receive a third identifier from the network device, where the third identifier is an identifier used by the first terminal device for the emergency service; based on the third identifier, a first connection is established with the first terminal device, and the first connection is used to transmit data of the emergency service.

[0040] In one possible implementation, the sixth terminal device establishes a first connection with the first terminal device, which can be specifically: the sixth terminal device receives a ninth message from the first terminal device, and the ninth message is used to request to establish the first connection, wherein the ninth message includes a relay service code for emergency services, and the source identifier used to send the ninth message is the third identifier.

[0041] In a possible implementation, the sixth terminal device may also receive a tenth message from the first terminal device, and the source identifier used to send the tenth message is the third identifier. Optionally, the tenth message may be sent by the first terminal device in response to a first identifier of the network device. Optionally, the sixth terminal device may send the tenth message to the network device via a third connection, and the third connection is a connection between the sixth terminal device and the network device.

[0042] In one possible implementation, the sixth terminal device may also send an eleventh message to the network device, where the eleventh message is used to request establishment of a third connection, where the third connection is a connection between the sixth terminal device and the network device, and the eleventh message includes a reason for establishing the third connection, which includes emergency services.

[0043] Based on the above implementation, the target terminal device can correctly set the reason for establishing the third connection, and establish the third connection supporting the emergency service with the network device, thereby ensuring that the data of the emergency service can be transmitted normally.

[0044] In a possible implementation, the sixth terminal device may also determine, based on the third identifier, that a reason for establishing the third connection includes an emergency service, and the third connection is a connection between the sixth terminal device and the network device.

[0045] For the technical effects that can be achieved by the above-mentioned third aspect and any possible implementation method thereof, please refer to the technical effects that can be achieved by the above-mentioned first aspect or second aspect and any possible implementation method thereof, and no further details will be given.

[0046] In a fourth aspect, the present application also provides a communication method, which can be applied to a core network device, or a component (such as a processor, chip, chip system, circuit or other, etc.) configured in the core network device, or a software module. The method may include: the core network device receives second indication information from a first terminal device, the second indication information indicates that a fourth terminal device needs to be switched, and the fourth terminal device provides a relay service for the first terminal device; and, sends third indication information to a network device, the third indication information indicates that a fifth terminal device is configured for the first terminal device, and the fifth terminal device supports the emergency service and has the ability to provide a relay service for the first terminal device.

[0047] For the technical effects that can be achieved in the fourth aspect, please refer to the technical effects that can be achieved in the first aspect and any possible implementation method thereof, and no further details will be given.

[0048] In a fifth aspect, the present application also provides a communication method, which can be applied to a first terminal device, or a component (such as a processor, chip, chip system, circuit or other, etc.) configured in the first terminal device, or a software module. The method may include: the first terminal device sends at least one first identifier to a network device, the first identifier being an identifier used by a second terminal device to provide a relay service for an emergency service; receiving a first identifier from the at least one first identifier of the network device; and establishing a first connection between a target terminal device corresponding to the first identifier, the first connection being used to transmit data of the emergency service.

[0049] Based on the above communication method, the first terminal device sends at least one first identifier to the network device, where the first identifier is an identifier of the second terminal device used to provide relay service for emergency services, enabling the network device to configure a relay terminal device that supports emergency services for the first terminal device based on the at least one first identifier, thereby ensuring that data of the emergency services can be transmitted normally.

[0050] In a possible implementation, the first terminal device may also receive a sixth message from the network device, the sixth message being used to request the first terminal device to send the at least one first identifier. Exemplarily, the sixth message may be sent by the network device in response to a seventh message from a core network device, the seventh message being used to request establishment of a first session, the first session being used for the emergency service.

[0051] In another possible implementation, an eighth message is first received from the network device, where the eighth message includes a trigger condition for sending the at least one first identifier, and the trigger condition includes data of the emergency service to be transmitted by the first terminal device.

[0052] Based on the above two implementation methods, the first terminal device can send at least one first identifier to the network device in response to the sixth message, or can also send at least one first identifier to the network device in response to a trigger condition. The implementation method is flexible.

[0053] In a possible implementation, the first terminal device may also send at least one identifier of the first terminal device to the network device, and the at least one identifier includes a third identifier, or includes a third identifier and a fourth identifier, wherein the third identifier is an identifier of the first terminal device used for the emergency service, and the fourth identifier is an identifier of the first terminal device used for non-emergency services.

[0054] In a possible implementation manner, there is a second connection between the target terminal device and the first terminal device, and the second connection is used to transmit data of non-emergency services.

[0055] In one possible implementation, the first terminal device establishes the first connection with the target terminal device corresponding to the first identifier by: releasing the second connection and establishing the first connection based on the first identifier; or updating the configuration information of the second connection based on the first identifier to obtain the first connection, and stopping transmitting the data of the non-emergency service.

[0056] In one possible implementation, the first terminal device establishes a first connection with a target terminal device corresponding to the first identifier, which may be specifically as follows: the first terminal device sends a ninth message to the target terminal device, and the ninth message is used to request establishment of the first connection, wherein the ninth message includes a relay service code for the emergency service, and the source identifier used to send the ninth message is a third identifier, and the third identifier is an identifier of the first terminal device used for the emergency service.

[0057] In a possible implementation, the first terminal device may also send a tenth message to the target terminal device, and the source identifier used to send the tenth message is the third identifier. Optionally, the tenth message may be sent by the first terminal device in response to the first identifier of the network device.

[0058] For the technical effects that can be achieved in the fifth aspect, please refer to the technical effects that can be achieved in the first aspect and any possible implementation method thereof, and no further details will be given.

[0059] In a sixth aspect, the present application further provides a communication method, which can be applied to a network device, or a component (such as a processor, a chip, a chip system, a circuit or other, etc.) configured in the network device, or a software module. The method may include: the network device receives at least one first identifier from a first terminal device, the first identifier being an identifier of a second terminal device for providing a relay service for an emergency service;

[0060] A first identifier among the at least one first identifier is sent to the first terminal device, and a third identifier is sent to a target terminal device corresponding to the one first identifier, so that the first terminal device establishes a first connection with the target terminal device, wherein the first connection is used to transmit data of the emergency service, and the third identifier is an identifier of the first terminal device used for the emergency service.

[0061] In a possible implementation, the network device may also send a sixth message to the first terminal device, the sixth message being used to request the first terminal device to send the at least one first identifier. Exemplarily, the network device may also receive a seventh message from a core network device, the seventh message being used to request the establishment of a first session, the first session being used for the emergency service; the network device sending the sixth message to the first terminal device may specifically be: the network device sending the sixth message to the first terminal device according to the seventh message.

[0062] In another possible implementation, the network device may further send an eighth message to the first terminal device, where the eighth message includes a trigger condition for sending the at least one first identifier, and the trigger condition includes data of the emergency service to be transmitted by the first terminal device.

[0063] In a possible implementation, the network device may also receive at least one identifier from the first terminal device, wherein the at least one identifier of the first terminal device includes the third identifier, or includes the third identifier and a fourth identifier, and the fourth identifier is an identifier of the first terminal device used for non-emergency services.

[0064] In one possible implementation, the network device may also receive at least one identifier from a sixth terminal device, wherein the at least one identifier of the sixth terminal device includes a fifth identifier and / or a sixth identifier, the fifth identifier being an identifier of the sixth terminal device used to provide relay service for the emergency service, and the sixth identifier being an identifier of the sixth terminal device used to provide relay service for non-emergency service, wherein if the at least one identifier of the sixth terminal device includes the fifth identifier, the sixth terminal device is the second terminal device.

[0065] In a possible implementation, the network device may also receive an eleventh message from the target terminal device, the eleventh message being used to request establishment of a third connection, the third connection being a connection between the target terminal device and the network device, the eleventh message including a reason for establishing the third connection, and the reason for establishing the third connection including emergency services.

[0066] In a possible implementation, the network device may also receive a tenth message from the target terminal device. Exemplarily, the tenth message may be sent by the first terminal device in response to the first identifier of the network device.

[0067] For the technical effects that can be achieved in the sixth aspect, please refer to the technical effects that can be achieved in the fifth aspect and any possible implementation method thereof, and no further details will be given.

[0068] In a seventh aspect, the present application provides a communication device. The communication device is used to execute the method described in the first aspect or the fourth aspect and any possible implementation thereof. The communication device is, for example, a first terminal device, or a functional module in the first terminal device, such as a baseband device or a chip system.

[0069] In a possible implementation, the communication device includes a baseband device and a radio frequency device.

[0070] In another possible implementation, the communication device includes a processing module (sometimes also referred to as a processing unit) and a transceiver module (sometimes also referred to as a transceiver unit). The transceiver module can implement a sending function and a receiving function. When the transceiver module implements the sending function, it can be called a sending module (sometimes also referred to as a sending unit), and when the transceiver module implements the receiving function, it can be called a receiving module (sometimes also referred to as a receiving unit). The sending module and the receiving module can be the same functional module, which is called a transceiver module, and the functional module can implement a sending function and a receiving function; or, the sending module and the receiving module can be different functional modules, and the transceiver module is a general term for these functional modules.

[0071] In an eighth aspect, the present application provides a communication device. The communication device is used to execute the method described in the second aspect or the sixth aspect and any possible implementation thereof. The communication device is, for example, a network device, or a functional module in a network device, such as a baseband device or a chip system.

[0072] In a possible implementation, the communication device includes a baseband device and a radio frequency device.

[0073] In another possible implementation, the communication device includes a processing module (sometimes also referred to as a processing unit) and a transceiver module (sometimes also referred to as a transceiver unit). The transceiver module can implement a sending function and a receiving function. When the transceiver module implements the sending function, it can be called a sending module (sometimes also referred to as a sending unit), and when the transceiver module implements the receiving function, it can be called a receiving module (sometimes also referred to as a receiving unit). The sending module and the receiving module can be the same functional module, which is called a transceiver module, and the functional module can implement a sending function and a receiving function; or, the sending module and the receiving module can be different functional modules, and the transceiver module is a general term for these functional modules.

[0074] In a ninth aspect, the present application provides a communication device. The communication device is used to execute the method described in the third aspect and any possible implementation thereof. The communication device is, for example, a sixth terminal device, or a functional module in the sixth terminal device, such as a baseband device or a chip system.

[0075] In a possible implementation, the communication device includes a baseband device and a radio frequency device.

[0076] In another possible implementation, the communication device includes a processing module (sometimes also referred to as a processing unit) and a transceiver module (sometimes also referred to as a transceiver unit). The transceiver module can implement a sending function and a receiving function. When the transceiver module implements the sending function, it can be called a sending module (sometimes also referred to as a sending unit), and when the transceiver module implements the receiving function, it can be called a receiving module (sometimes also referred to as a receiving unit). The sending module and the receiving module can be the same functional module, which is called a transceiver module, and the functional module can implement a sending function and a receiving function; or, the sending module and the receiving module can be different functional modules, and the transceiver module is a general term for these functional modules.

[0077] In a tenth aspect, the present application provides a communication device. The communication device is used to execute the method described in the implementation of the fourth aspect. The communication device is, for example, a core network device, or a functional module in a core network device, such as a baseband device or a chip system.

[0078] In a possible implementation, the communication device includes a baseband device and a radio frequency device.

[0079] In another possible implementation, the communication device includes a processing module (sometimes also referred to as a processing unit) and a transceiver module (sometimes also referred to as a transceiver unit). The transceiver module can implement a sending function and a receiving function. When the transceiver module implements the sending function, it can be called a sending module (sometimes also referred to as a sending unit), and when the transceiver module implements the receiving function, it can be called a receiving module (sometimes also referred to as a receiving unit). The sending module and the receiving module can be the same functional module, which is called a transceiver module, and the functional module can implement a sending function and a receiving function; or, the sending module and the receiving module can be different functional modules, and the transceiver module is a general term for these functional modules.

[0080] In the eleventh aspect, the present application also mentions a communication system, comprising one or more of the following: the communication device described in the seventh aspect above, the communication device described in the eighth aspect above, the communication device described in the ninth aspect above, or the communication device described in the tenth aspect above.

[0081] In a twelfth aspect, the present application also provides a chip system. The chip system may include at least one processor. Optionally, the at least one processor is coupled to a memory. The at least one processor is used to execute one or more computer programs or instructions in the memory to implement the method described in any one of the first to sixth aspects above and any possible implementation thereof. Optionally, the chip system may be composed of a chip, or may include a chip and other discrete devices. Optionally, the chip system may also include a memory.

[0082] In the thirteenth aspect, the present application also provides a computer-readable storage medium, which is used to store computer programs or instructions. When the computer-readable storage medium is executed, the method described in any aspect of the first to sixth aspects above and any possible implementation method thereof is implemented.

[0083] In a fourteenth aspect, the present application also provides a computer program product comprising instructions, which, when executed on a computer, enables the method described in any one of the first to sixth aspects and any possible implementation thereof to be implemented.

[0084] For the technical effects that can be achieved by the above-mentioned seventh to fourteenth aspects and any possible implementation methods thereof, please refer to the technical effects that can be achieved by the above-mentioned first and sixth aspects and any possible implementation methods thereof, and no repetition will be given. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 is a schematic diagram of a U2N communication scenario;

[0086] Figure 2 A schematic diagram of the architecture of a communication system;

[0087] Figure 3 is a schematic diagram of the structure of a RAN node;

[0088] Figure 4 is a schematic diagram of a D2D communication scenario;

[0089] Figure 5 is a schematic diagram of an L2 protocol stack;

[0090] Figure 6 A flow chart of a communication method provided in an embodiment of the present application;

[0091] Figure 7 A flowchart of another communication method provided in an embodiment of the present application;

[0092] Figure 8 A flowchart of another communication method provided in an embodiment of the present application;

[0093] Fig. 9 A flowchart of another communication method provided in an embodiment of the present application;

[0094] Fig.10 A flowchart of another communication method provided in an embodiment of the present application;

[0095] Fig.11 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0096] Fig.12 A schematic diagram of the structure of another communication device provided in an embodiment of the present application;

[0097] Fig.13 A schematic diagram of the structure of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0098] The embodiments of the present application will be presented around a system including multiple devices, components, modules, etc. It should be understood that the system may include other devices, components, modules, etc. not mentioned, or may only include some of the devices, components, or modules, etc. mentioned in the embodiments.

[0099] The embodiments of the present application provide a communication method, device and communication system for enabling a network device to configure a relay UE for a remote UE to ensure that data of an emergency service can be transmitted normally. The method and device described in the present application are based on the same technical concept. Since the principles of solving problems by the method and device are similar, the implementation of the device and the method can refer to each other, and the repeated parts will not be repeated.

[0100] In the embodiments of the present application, "multiple" may refer to two or more than two. In view of this, in the embodiments of the present application, "multiple" may also be understood as "at least two". "At least one" may be understood as one or more, for example, one, two or more. For example, "including at least one" means including one, two or more. For example, including at least one of A, B and C, then A, B, C, A and B, A and C, B and C, or A, B and C may be included. "And / or" describes the association relationship of associated objects. Specifically, there may be three relationships. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the previously associated objects are in an "or" relationship.

[0101] In addition, the terms "system" and "network" in the embodiments of the present application may be used interchangeably, and "according to" and "based on" may be used interchangeably.

[0102] The ordinal numbers such as "first", "second", "third" etc. mentioned in the embodiments of the present application are generally used to distinguish different objects and are not used to limit the order, timing, priority or importance of multiple objects.

[0103] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0104] The following first introduces a communication system to which the embodiments of the present application are applicable.

[0105] The network architecture and application scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. It is known to those skilled in the art that with the evolution of network architecture and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems. Figure 2 The communication system shown is described as an example. When the technical solutions of the embodiments of the present application are applied to other communication systems, the devices, components, modules, etc. in the embodiments can be replaced with corresponding devices, components, modules in other communication systems without limitation.

[0106] like Figure 2 As shown, the communication system 1000 includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the communication system 100 may also include the Internet 300. The RAN 100 includes at least one RAN node (such as Figure 2 110a and 110b, collectively referred to as 110) and at least one terminal (such as Figure 2 RAN 100 may also include other RAN nodes, such as wireless relay equipment and / or wireless backhaul equipment ( Figure 2 The terminal 120 is connected to the RAN node 110 in a wireless manner. The RAN node 110 is connected to the core network (CN) 200 in a wireless or wired manner. The core network device in the core network 200 and the RAN node 110 in the RAN 100 can be different physical devices, or can be the same physical device that integrates the core network logical function and the radio access network logical function.

[0107] The core network equipment in the core network 200, which may also be referred to as core network network elements, may be divided into control plane network elements and user plane network elements. Control plane network elements may include, for example, access management function network elements, unified data management network elements, session management function network elements, policy control function network elements, or network storage function network elements. User plane network elements may include, for example, user plane function network elements. Exemplarily, the access management function network element, which may also be referred to as access management function equipment, is responsible for access control and mobility management of terminal access to the operator's network, such as mobile state management, allocation of user temporary identity identification, authentication and authorization and other functions. In a 5G communication system, the access management function network element may be an access and mobility management function (AMF) network element. In future communication systems, the access management function network element may also have other names, without limitation.

[0108] RAN 100 may be a cellular system related to the 3rd Generation Partnership Project (3GPP), for example, a 4th generation (4G) mobile communication system (such as a long term evolution (LTE) system), a 5th generation (5G) mobile communication system (such as a new radio (NR) system), or a future-oriented evolution system (such as a 6th generation (6G) mobile communication system). RAN 100 may also be an open access network (open RAN, O-RAN or ORAN), a cloud radio access network (cloud radio access network, CRAN), or a wireless fidelity (wireless fidelity, WiFi) system. RAN 100 may also be a communication system that integrates two or more of the above systems.

[0109] The RAN node 110, which may also be sometimes referred to as an access network device, an access network element, a network device, a network apparatus, a RAN entity, or an access node, constitutes a part of a communication system to help a terminal achieve wireless access. The multiple RAN nodes 110 in the communication system 1000 may be nodes of the same type or nodes of different types. In some scenarios, the roles of the RAN node 110 and the terminal 120 are relative, for example, Figure 2 The network element 120i may be a helicopter or a drone, which may be configured as a mobile base station. For the terminals 120j that access the RAN 100 through the network element 120i, the network element 120i is a base station; but for the base station 110a, the network element 120i is a terminal. The RAN node 110 and the terminal 120 are sometimes referred to as communication devices, for example Figure 2 The network elements 110a and 110b may be understood as communication devices having base station functions, and the network elements 120a-120j may be understood as communication devices having terminal functions.

[0110] In one possible scenario, a RAN node may be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next generation NodeB (gNB), a next generation base station in a sixth generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. A RAN node may be a macro base station (e.g. Figure 2 110a in), micro base stations or indoor stations (such as Figure 2 110b in the example above), a relay node or a donor node, or a wireless controller in a CRAN scenario. Optionally, the RAN node may also be a server, a wearable device, a vehicle or an onboard device, etc. For example, the access network device in the vehicle to everything (V2X) technology may be a road side unit (RSU).

[0111] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, and different RAN nodes respectively implement part of the functions of the base station. For example, the RAN node can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be set separately, or can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU) or a remote radio head (RRH).

[0112] 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 described as examples in this application. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0113] In the embodiments of the present application, the functions of the RAN node may also be performed by a module (such as a chip) in the RAN node, or by a control subsystem including the RAN node functions. The control subsystem including the RAN node functions here may be a control center in the above application scenarios such as smart grid, industrial control, smart transportation, and smart city.

[0114] The terminal may also be referred to as a terminal device, a terminal apparatus, a UE, a mobile station, or a mobile terminal. The terminal can be widely used in various scenarios, for example, device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IOT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, or smart city. Exemplarily, the terminal may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a robotic arm, or a smart home device. The embodiments of the present application do not limit the device form of the terminal.

[0115] In the embodiment of the present application, the functions of the terminal may also be performed by a module (such as a chip or a modem) in the terminal, or may be performed by a device that includes the terminal functions.

[0116] RAN nodes and terminals can be fixed or mobile. RAN nodes and terminals can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on aircraft, balloons, and artificial satellites in the air. The embodiments of the present application do not limit the application scenarios of RAN nodes and terminals.

[0117] The communication between the RAN node and the terminal follows a certain protocol layer structure. The protocol layer may include a control plane protocol layer and a user plane protocol layer. The control plane protocol layer may include at least one of the following: a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, a media access control (MAC) layer, or a physical (PHY) layer. The user plane protocol layer may include at least one of the following: a service data adaptation protocol (SDAP) layer, a PDCP layer, an RLC layer, a MAC layer, or a physical layer.

[0118] like Figure 3 As shown, a RAN node may include one or more CUs, one or more DUs, and one or more RUs. For clarity, Figure 3Only one CU, DU and RU are shown. The CU is used to connect to the core network and one or more DUs. Optionally, the CU may have some functions of the core network. The CU may include a CU-CP and a CU-UP.

[0119] CU and DU can be configured according to the protocol layer functions of the wireless network they implement. For example, CU is configured to implement the functions of the PDCP layer and the protocol layers above (such as the RRC layer and / or the SDAP layer, etc.); DU is configured to implement the functions of the protocol layers below the PDCP layer (such as the RLC layer, the MAC layer, and / or the PHY layer, etc.). For another example, CU is configured to implement the functions of the protocol layers above the PDCP layer (such as the RRC layer and / or the SDAP layer), and DU is configured to implement the functions of the PDCP layer and the protocol layers below (such as the RLC layer, the MAC layer, and / or the PHY layer, etc.).

[0120] When the CU includes a CU-CP and a CU-UP, the CU-CP is used to implement the control plane function of the CU, and the CU-UP is used to implement the user plane function of the CU. For example, when the CU is configured to implement the functions of the PDCP layer, the RRC layer, and the SDAP layer, the CU-CP is used to implement the control plane function of the RRC layer and the PDCP layer, and the CU-UP is used to implement the user plane function of the SDAP layer and the PDCP layer.

[0121] CU-CP can interact with network elements in the core network for implementing control plane functions. The network elements in the core network for implementing control plane functions can be access and mobility function network elements, for example, access and mobility management function (AMF) network elements in 5G systems. The access and mobility function network elements are responsible for mobility management in mobile networks, such as location update of terminal devices, registration network of terminal devices, switching of terminal devices, etc.

[0122] CU-UP can interact with network elements in the core network for implementing user plane functions. Network elements in the core network for implementing user plane functions, for example, user plane function (UPF) network elements in the 5G system, are responsible for forwarding and receiving data in terminal devices.

[0123] The above configuration of CU and DU is only an example, and the functions of CU and DU can also be configured as needed. For example, CU or DU can be configured to have functions of more protocol layers, or CU or DU can be configured to have partial processing functions of protocol layers. For example, some functions of the RLC layer and the functions of the protocol layers above the RLC layer are set in the CU, and the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer are set in the DU. For another example, the functions of CU or DU can be divided according to service type or other system requirements, such as by delay, and the functions whose processing time needs to meet the smaller delay requirement are set in the DU, and the functions that do not need to meet the delay requirement are set in the CU.

[0124] The foregoing describes a communication system to which the embodiments of the present application are applicable. Next, some technical features involved in the embodiments of the present application are introduced.

[0125] In a wireless communication system, data communication can be performed between UEs through network devices, or directly between UEs without the help of network devices. This communication scenario is called a D2D communication scenario. When UEs communicate directly with each other, the link between UEs is called a sidelink (SL), and its interface is a PC5 interface. Figure 4 As shown, UE1 and UE2 directly transmit data through the side link without going through the network, which can effectively reduce communication delay.

[0126] Broadcast communication, multicast communication and unicast communication are supported on the sidelink. Broadcast communication is similar to the base station broadcasting system information, that is, the UE sends broadcast service data to the outside without encryption, and any other UE within the effective reception range can receive the data of the broadcast service if they are interested in the broadcast service. Multicast communication refers to the communication between all UEs in a communication group, and any UE in the communication group can send and receive the data of the multicast service.

[0127] Unicast communication is similar to the data communication performed after the RRC connection is established between the UE and the base station, and requires the establishment of a unicast connection between the two UEs in advance. After the unicast connection is established, the two UEs can communicate data based on the negotiated identifier, and the data can be encrypted or unencrypted. Compared with broadcast communication, in unicast communication, unicast communication can only be performed between two UEs that have established a unicast connection. A unicast communication on the sidelink corresponds to a pair of source layer 2 identifiers (source layer 2 identifier, source L2 ID) and destination layer 2 identifiers (destination layer2 identifier, destination L2 ID). The subheader of each sidelink media access control layer data protocol unit (media access control protocol data unit, MAC PDU) will contain the source L2 ID and destination L2ID so that data can be transmitted from the sender to the correct receiver.

[0128] U2N relay is a technology that allows a UE to help another UE communicate with a base station, such as Figure 1 As shown. U2N relay technology mainly has two protocol architectures: layer 2 (layer 2, L2) and layer 3 (layer 3, L3). The embodiment of this application mainly involves the L2 protocol architecture. Figure 5 As shown, in the L2 protocol architecture, the data packets of the remote UE are relayed below the PDCP layer of the relay UE, that is, the relay UE only maintains the relayed RLC bearer, including the RLC layer, MAC layer and PHY layer. Therefore, there is an end-to-end PDCP layer between the remote UE and the base station, but there is no end-to-end RLC layer, MAC layer and PHY layer. In addition, a sidelink relay adaptation protocol adaptation layer (SRAP) is added between the RLC layer and the PDCP layer. The main function of the SRAP layer is to multiplex and demultiplex the bearers, that is, to support different bearers to be multiplexed into one bearer or to split one bearer into different bearers, and to distinguish the data of different remote UEs. The adaptation layer in the protocol stack at both ends of the PC5 interface is called PC5-SRAP, and the adaptation layer in the protocol stack at both ends of the Uu interface is called Uu-SRAP.

[0129] In one possible implementation, in the U2N relay communication scenario, the remote UE and the relay UE have a dedicated relay service code for emergency services (also called emergency services), which is used to discover and establish a PC5 connection, and the PC5 connection associated with the RSC for emergency services is only used to transmit data for the emergency services. The relay UE will only indicate to the remote UE that it supports emergency services during the discovery process. Then, when the remote UE has emergency service data to be transmitted, how to achieve the transmission of the emergency service data is a technical problem that needs to be solved.

[0130] In view of this, the embodiments of the present application provide a communication method, apparatus and communication system for enabling a network device to configure a relay UE for a remote UE to ensure that emergency service data can be transmitted normally. Figure 1 or Figure 2 The communication system shown is not limited.

[0131] The following is an introduction to some technical terms involved in the embodiments of the present application.

[0132] The first terminal device may be a remote UE, for example Figure 1 A remote UE or a component in the remote UE in the communication system shown; or Figure 2 The UE in the communication system shown or the components in the UE are not limited. In the embodiment of the present application, the first terminal device supports emergency services. It should be noted that the first terminal device can communicate with the network device through one or more relay terminal devices. For ease of understanding, the embodiment of the present application is described by taking the first terminal device communicating with the network device through a relay terminal device as an example.

[0133] Network devices can be Figure 1 A network device in the communication system shown or a component in the network device; or Figure 2 The RAN node 110 in the communication system shown or the components in the RAN node 110 are not limited. In the embodiment of the present application, the network device supports emergency services.

[0134] The second terminal device may be a relay UE, also referred to as a candidate relay UE, which has the capability of providing relay services for the first terminal device and supports emergency services. Optionally, the second terminal device provides relay services for the first terminal device, in other words, the first terminal device communicates with the network device through the second terminal device, which may be referred to as a service relay UE. Optionally, the second terminal device may also support non-emergency services.

[0135] The third terminal device may be a relay UE, or may be referred to as a candidate relay UE, which has the capability of providing relay services for the first terminal device and supports non-emergency services. Optionally, the third terminal device may also support emergency services. In this case, the third terminal device is the same terminal device as the second terminal device, that is, one terminal device supports both emergency services and non-emergency services.

[0136] The fourth terminal device may be a relay UE. In an embodiment of the present application, the fourth terminal device may provide a relay service for the first terminal device, that is, the fourth terminal device is a terminal device that currently provides a relay service for the first terminal device. In addition, the connection (such as a unicast connection) established between the fourth terminal device and the first terminal device may be recorded as a second connection, and the second connection is used to transmit data for non-emergency services. The fourth terminal device may or may not support emergency services without restriction. When the fourth terminal device supports emergency services, the fourth terminal device and the second terminal device may be the same terminal device, and / or the fourth terminal device and the target terminal device may be the same terminal device.

[0137] The fifth terminal device may be a relay UE. In the application embodiment, the fifth terminal device may be a terminal device that the core network device indicates the network device is configured for the first terminal device, and the fifth terminal device has the ability to provide a relay service for the first terminal device and supports emergency services.

[0138] The sixth terminal device may be an active relay UE capable of providing services to the first terminal device, or the sixth terminal device may be an inactive or idle relay UE. The sixth terminal device may or may not support emergency services, without limitation.

[0139] The target terminal device may be a relay UE, which is a terminal device configured by the network device for the first terminal device and used for emergency services. The target terminal device has the ability to provide relay services for the first terminal device and supports emergency services. Optionally, the target terminal device may also support non-emergency services. In addition, the connection established between the target terminal device and the first terminal device may be recorded as a first connection, which is used to transmit data for emergency services.

[0140] Exemplarily, the second terminal device, the third terminal device, the fourth terminal device, the fifth terminal device or the sixth terminal device may be Figure 1 A relay UE or a component in the relay UE in the communication system shown; or it may also be Figure 2 The UE in the communication system shown or the components in the UE are not limited.

[0141] Emergency service is a communication service used to access a public emergency center. Optionally, the emergency service may have a specific local access number and a higher priority. In addition, the emergency service may also have a unique interaction process. The emergency service may also be called a first service, an emergency service, or an emergency service, etc., without limitation. In addition, services other than the emergency service may be called a non-emergency service, a second service, a normal service, or a normal service, etc., without limitation.

[0142] The indication domain can be understood as a field of signaling, or can also be understood as indication information. In an embodiment of the present application, an L2 ID can correspond to an indication domain, or an L2 ID is associated with an indication domain. This indication domain can be used to indicate that the terminal device corresponding to this L2 ID supports emergency services, or to indicate that the terminal device corresponding to this L2 ID supports non-emergency services. For example, an indication domain corresponding to L2 ID#1 is recorded as indication domain 1, and the indication domain 1 is used to indicate that the terminal device corresponding to L2 ID#1 supports emergency services, or to indicate that the terminal device corresponding to L2 ID#1 supports non-emergency services.

[0143] It should be noted that one or more of the second terminal device, the third terminal device, the fourth terminal device, the fifth terminal device or the sixth terminal device may be the same terminal device.

[0144] In addition, the term "supporting emergency services" may be replaced by "supporting forwarding data of emergency services" or by "supporting provision of relay services for emergency services".

[0145] Figure 6 FIG. 1 is a flow chart of a communication method provided by an embodiment of the present application. In this embodiment, a first terminal device sends a first message to a network device when there is data of an emergency service to be transmitted. Figure 6 As shown, the method may include the following contents.

[0146] S601: A first terminal device sends a first message to a network device.

[0147] Accordingly, the network device receives the first message from the first terminal device. For example, the DU receives the first message from the first terminal device and forwards the first message to the CU so that the CU processes the first message.

[0148] In this embodiment, the first terminal device sends the first message to the network device when there is data of an emergency service to be transmitted. For example, the first terminal device can actively send the first message to the network device when there is data of an emergency service to be transmitted; or, the first terminal device can also send the first message to the network device in response to a trigger condition when there is data of an emergency service to be transmitted. For example, before S601, the network device can send a third message to the first terminal device, and the third message includes a trigger condition for sending the first message, and the trigger condition may include data of an emergency service to be transmitted by the first terminal device. The first terminal device receives the third message from the network device, and sends the first message to the network device in response to the trigger condition when there is data of an emergency service to be transmitted. Optionally, the third message may also include measurement configuration information, and the measurement configuration information may include, for example, a measurement target, which is used to indicate the frequency point information of the measurement, so that the first terminal device measures at least one relay terminal device based on the measurement configuration information. It should be noted that the measurement configuration information may be included in the third message, or may not be included in the third message, such as the network device sending the third message and the measurement configuration information to the first terminal device, without limitation.

[0149] The trigger condition may be a measurement report trigger event, and the measurement report trigger event is data of emergency services to be transmitted by the first terminal device. For example, the first terminal device receives measurement configuration information and a measurement report trigger event from a network device, measures at least one relay terminal device according to the measurement configuration information, and in response to the measurement report trigger event, sends a measurement result and a first message to the network device when data of emergency services to be transmitted. Optionally, the measurement result may be included in the first message, or the first message is included in the measurement result, without limitation. The measurement result may, for example, include but is not limited to one or more of the following: an identifier of a serving cell, or link quality, etc.

[0150] Alternatively, the trigger condition may also be indication information, which is carried in other configuration (otherconfig) information elements and is used to instruct the first terminal device to send a first message when there is data of an emergency service to be transmitted, such as sending the first message through UE assistance information (UE assistance information, UAI). For example, the first terminal device receives measurement configuration information and other config information elements from a network device, measures at least one relay terminal device according to the measurement configuration information, and in response to the indication information in the other config information element, when there is data of an emergency service to be sent, sends the first message and the measurement result to the network device through UAI. For another example, the first terminal device receives other config information elements from a network device, determines information of at least one terminal device supporting an emergency service through a discovery process, and in response to the indication information in the other config information element, sends the first message to the network device through UAI when there is data of an emergency service to be sent.

[0151] The first message can be carried in a measurement report message, or the first message includes a measurement report, or is carried in the UAI, without limitation. The first message includes at least one first identifier, such as at least one L2ID. The first identifier is an identifier of the second terminal device used to provide relay services for emergency services, or is expressed as the first identifier is an identifier of the second terminal device used for emergency services, or is expressed as the first identifier is an identifier of the second terminal device used to forward data for emergency services. Among them, the at least one first identifier corresponds one-to-one with at least one second terminal device, that is, a first identifier in the at least one first identifier corresponds to a second terminal device in the at least one second terminal device, and a second terminal device in the at least one second terminal device corresponds to a first identifier in the at least one first identifier. In other words, each first identifier in the at least one first identifier is an identifier for emergency services, and a first identifier corresponds to a second terminal device. For example, the at least one first identifier includes L2 ID#1, L2ID#2 and L2 ID#3, L2 ID#1 is the identifier of terminal device 1 for emergency services, L2 ID#2 is the identifier of terminal device 2 for emergency services, and L2 ID#3 is the identifier of terminal device 3 for emergency services.

[0152] The first message also includes an indication field of the first identifier (or replaced by indication information associated with the first identifier, or replaced by indication information corresponding to the first identifier). The indication field of the first identifier is used to indicate that the second terminal device supports emergency services. In other words, the first message includes at least one first identifier and at least one indication field of the at least one first identifier. The at least one first identifier and the at least one indication field correspond one-to-one, that is, one first identifier in the at least one first identifier corresponds to one indication field in the at least one indication field, and one indication field in the at least one indication field corresponds to one first identifier in the at least one first identifier. An indication field is used to indicate that the terminal device corresponding to the first identifier thereof supports emergency services. For example, the first message includes: {L2 ID#1, indication field 1}, {L2 ID#2, indication field 2} and {L2 ID#3, indication field 3}, wherein indication field 1 is used to indicate that the terminal device corresponding to L2 ID#1 supports emergency services, indication field 2 is used to indicate that the terminal device corresponding to L2 ID#2 supports emergency services, and indication field 3 is used to indicate that the terminal device corresponding to L2 ID#1 supports emergency services.

[0153] Exemplarily, Table 1 shows the measurement result of UE1 by taking the indication field as the emergencySupported-r18 field as an example. The measurement result of UE1 includes the emergencySupported-r18 field, indicating that the UE1 corresponding to the L2 ID supports emergency services. If the measurement result of UE1 does not include the emergencySupported-r18 field, it means that the UE1 corresponding to the L2 ID supports non-emergency services. It should be understood that the various parameters in Table 1 are examples and are not limited thereto.

[0154] Table 1

[0155]

[0156] The first terminal device can indicate that the second terminal device supports emergency services by carrying an indication field of a first identifier in a first message. In another possible implementation, the first terminal device can also indicate that the second terminal device supports emergency services by taking a value of the indication field of the first identifier. Exemplarily, the value of the indication field of the first identifier includes a first value and a second value, the first value being used to indicate that the second terminal device supports emergency services, and the second value being used to indicate that the second terminal device supports non-emergency services. In an embodiment of the present application, the value of the indication field of the first identifier is the first value. For example, the indication field of the first identifier occupies 1 bit. If the value of the indication field of the first identifier is 1, it indicates that the second terminal device supports emergency services, or if the value of the indication field of the first identifier is 0, it indicates that the second terminal device supports non-emergency services. In this case, the value of the indication field of the first identifier in an embodiment of the present application is 1. For another example, the indication field of the first identifier occupies 1 bit. If the value of the indication field of the first identifier is 0, it indicates that the second terminal device supports emergency services; or if the value of the indication field of the first identifier is 1, it indicates that the second terminal device supports non-emergency services. In this case, the value of the indication field of the first identifier in the embodiment of the present application is 0.

[0157] Exemplarily, Table 2 shows the measurement result of UE1 using the indication field as the emergencySupported-r18 field as an example. In the measurement result of UE1, the value of the emergencySupported-r18 field is num0, indicating that the UE1 corresponding to the L2 ID supports emergency services; the value of the emergencySupported-r18 field is num1, indicating that the UE1 corresponding to the L2 ID supports non-emergency services. Alternatively, the value of the emergencySupported-r18 field is num1, indicating that the UE1 corresponding to the L2 ID supports emergency services; the value of the emergencySupported-r18 field is num0, indicating that the UE1 corresponding to the L2 ID supports non-emergency services. It should be understood that the various parameters in Table 2 are examples and are not limited to this.

[0158] Table 2

[0159]

[0160] It should be noted that the first terminal device can measure terminal devices that only support emergency services, or it can measure all terminal devices discovered by the first terminal device in the discovery process (or measure all terminal devices corresponding to the measurement configuration information of the network device) without restriction.

[0161] Optionally, the first message may also include at least one second identifier, such as at least one L2 ID. That is, the first message includes at least one first identifier, at least one indication field of at least one first identifier, and at least one second identifier. The second identifier is an identifier of the third terminal device used to provide relay services for non-emergency services, or is expressed as the second identifier is an identifier of the third terminal device used for non-emergency services, or is expressed as the second identifier is an identifier of the third terminal device used to forward data for non-emergency services. Among them, the at least one second identifier corresponds one-to-one with the at least one third terminal device, that is, a second identifier in the at least one second identifier corresponds to a third terminal device in the at least one third terminal device, and a third terminal device in the at least one third terminal device corresponds to a second identifier in the at least one second identifier. In other words, each second identifier in the at least one second identifier is an identifier for non-emergency services, and a second identifier corresponds to a third terminal device. For example, the at least one second identifier includes L2 ID#4, L2ID#5 and L2 ID#6, L2 ID#4 is the identifier of terminal device 4 for non-emergency services, L2 ID#5 is the identifier of terminal device 5 for non-emergency services, and L2ID#6 is the identifier of terminal device 6 for non-emergency services. It should be understood that a third terminal device and a second terminal device may be the same terminal device, that is, a terminal device can support both emergency services and non-emergency services. For example, the first message includes L2 ID#1 and L2 ID#7, L2 ID#1 is the identifier of terminal device 1 for emergency services, and L2 ID#7 is the identifier of terminal device 1 for non-emergency services.

[0162] The first message may not include the indication field of the second identifier (or be replaced by the indication information associated with the second identifier, or replaced by the indication information corresponding to the second identifier), and the first message may be used to indicate that the third terminal device supports non-emergency services. In other words, the first message does not include the indication field corresponding to the at least one second identifier, so as to implicitly indicate that the at least one third terminal device corresponding to the at least one second identifier supports non-emergency services. For details, please refer to the description in Table 1, which will not be repeated here.

[0163] The first terminal device can indicate that the third terminal device supports non-emergency services by not carrying the indication field of the second identifier in the first message. In another possible implementation, the first terminal device can also indicate that the third terminal device supports non-emergency services by the value of the indication field of the second identifier. That is, the first message can also include the indication field of the second identifier. The indication field of the second identifier is used to indicate that the third terminal device supports non-emergency services. In other words, the first message includes at least one first identifier, at least one indication field of the at least one first identifier, at least one second identifier and at least one indication field of the at least one second identifier. The at least one second identifier and the at least one indication field correspond one-to-one, that is, a second identifier in the at least one second identifier corresponds to an indication field in the at least one indication field, and an indication field in the at least one indication field corresponds to a second identifier in the at least one second identifier. An indication field is used to indicate that the terminal device corresponding to the second identifier corresponding to it supports non-emergency services. For example, the first message also includes: {L2ID#4, indication field 4}, {L2 ID#5, indication field 5} and {L2 ID#6, indication field 6}, wherein indication field 4 is used to indicate that the terminal device corresponding to L2ID#4 supports non-emergency services, indication field 5 is used to indicate that the terminal device corresponding to L2 ID#5 supports non-emergency services, and indication field 6 is used to indicate that the terminal device corresponding to L2 ID#6 supports non-emergency services.

[0164] Exemplarily, the value of the indication field of the second identifier includes a first value and a second value, the first value is used to indicate that the third terminal device supports emergency services, and the second value is used to indicate that the third terminal device supports non-emergency services. In the embodiment of the present application, the value of the indication field of the second identifier is the second value. For example, the indication field of the second identifier occupies 1 bit. If the value of the indication field of the second identifier is 1, it indicates that the third terminal device supports emergency services, or if the value of the indication field of the second identifier is 0, it indicates that the third terminal device supports non-emergency services. In this case, the value of the indication field of the second identifier in the embodiment of the present application is 0. For another example, the indication field of the second identifier occupies 1 bit. If the value of the indication field of the second identifier is 0, it indicates that the third terminal device supports emergency services, or if the value of the indication field of the second identifier is 1, it indicates that the third terminal device supports non-emergency services. In this case, the value of the indication field of the second identifier in the embodiment of the present application is 1. For details, please refer to the description of Table 2 and will not be repeated here.

[0165] Taking the example that the indication field occupies 1 bit and the value of the indication field is 1, indicating support for emergency services, otherwise it indicates support for non-emergency services, the first message includes: {L2 ID#1, 1}, {L2 ID#2, 1} and {L2 ID#4, 0}, among which the terminal device corresponding to L2 ID#1 supports emergency services, the terminal device corresponding to L2 ID#2 supports emergency services, and the terminal device corresponding to L2 ID#4 supports non-emergency services.

[0166] In a possible implementation, the first terminal device may also send at least one identifier of the first terminal device to the network device, such as sending at least one identifier of the first terminal device to the network device before S601; accordingly, the network device receives at least one identifier of the first terminal device. Among them, the at least one identifier of the first terminal device includes a third identifier, or includes a fourth identifier, or includes a third identifier and a fourth identifier. The third identifier is an identifier of the first terminal device for emergency services. The fourth identifier is an identifier of the first terminal device for non-emergency services. Optionally, at least one identifier of the first terminal device is carried in the sidelink user information (sidelink UE information, SUI), without limitation. In an embodiment of the present application, at least one identifier of the first terminal device includes a third identifier, that is, the embodiment of the present application is introduced by taking the first terminal device supporting emergency services as an example.

[0167] In a possible implementation, the sixth terminal device may send at least one identifier of the sixth terminal device to the network device, such as sending at least one identifier of the sixth terminal device to the network device before S601; accordingly, the network device receives at least one identifier of the sixth terminal device. Optionally, at least one identifier of the sixth terminal device is carried in the SUI, without limitation. Among them, the sixth terminal device is in a connected state and has the ability to provide relay services for the first terminal device. At least one identifier of the sixth terminal device includes a fifth identifier, or includes a sixth identifier, or includes a fifth identifier and a sixth identifier. The fifth identifier is an identifier of the sixth terminal device for providing relay services for emergency services, or is expressed as an identifier of the sixth terminal device for performing a discovery process related to emergency services. The sixth identifier is an identifier of the sixth terminal device for providing relay services for non-emergency services, or is expressed as an identifier of the sixth terminal device for performing a discovery process related to non-emergency services. For example, if the sixth terminal device sends the fifth identifier to the network device, the sixth terminal device can send an RSC corresponding to the emergency service in the discovery process, such as carrying the RSC corresponding to the emergency service in a notification message related to broadcast emergency services. For another example, if the sixth terminal device sends a sixth identifier to the network device, the sixth terminal device can send the RSC corresponding to the non-emergency service in the discovery process, such as carrying the RSC corresponding to the non-emergency service in the notification message related to the broadcast non-emergency service. Furthermore, if at least one identifier of the sixth terminal device includes the fifth identifier, the sixth terminal device is the second terminal device. Optionally, the sixth terminal device can be the target terminal device.

[0168] S602: The network device sends a first identifier of the at least one first identifier to the first terminal device.

[0169] Correspondingly, the first terminal device receives the first identifier from the network device.

[0170] One of the at least one first identifiers may be carried in an RRC reconfiguration message, that is, the network device sends an RRC reconfiguration message to the first terminal device, and the RRC reconfiguration message includes the one first identifier. The embodiment of the present application does not limit the specific implementation method of the network device sending a first identifier to the first terminal device. For example, the CU generates an RRC reconfiguration message, the RRC reconfiguration message includes one of the at least one first identifier, and sends the RRC reconfiguration message to the DU. Furthermore, the DU sends the RRC reconfiguration message to the first terminal device.

[0171] Exemplarily, after receiving the first message, the network device can determine a second terminal device as the target terminal device from at least one second terminal device corresponding to at least one first identifier, send the first identifier corresponding to the target terminal device to the first terminal device (i.e., execute S602), and send a third identifier to the target terminal device (i.e., execute S603). For example, if the first message includes a first identifier, the network device determines that the terminal device corresponding to the first identifier is the target terminal device. For another example, if the first message includes multiple first identifiers, the network device selects a second terminal device from multiple second terminal devices corresponding to the multiple first identifiers as the target terminal device. The embodiment of the present application does not limit the specific implementation process of the network device determining the target terminal device.

[0172] Optionally, the target terminal device can provide a relay service for the first terminal device (i.e., the target terminal device is a fourth terminal device). In other words, the target terminal device selected by the network device for the first terminal device can be a terminal device that currently provides a relay service for the first terminal device, and the relay terminal device is not switched. Accordingly, there is a second connection between the target terminal device and the first terminal device. In an embodiment of the present application, the second connection is used to transmit data of non-emergency services.

[0173] It should be noted that if the first message includes multiple first identifiers, the network device can send multiple first identifiers of the multiple first identifiers to the first terminal device. In other words, the network device can select multiple target terminal devices for the first terminal device. The embodiment of the present application is described by taking the network device selecting a target terminal device for the first terminal device as an example.

[0174] S603: The network device sends a third identifier to the target terminal device.

[0175] Correspondingly, the target terminal device receives the third identifier from the network device.

[0176] The third identifier is an identifier used by the first terminal device for emergency services. The third identifier can be carried in an RRC reconfiguration message, that is, the network device sends an RRC reconfiguration message to the target terminal device, and the RRC reconfiguration message includes the third identifier. The embodiment of the present application does not limit the specific implementation method of the network device sending the third message to the target terminal device. For example, the CU generates an RRC reconfiguration message, the RRC reconfiguration message includes the third identifier, and sends the RRC reconfiguration message to the DU. Furthermore, the DU sends the RRC reconfiguration message to the target terminal device.

[0177] It should be understood that the execution order of S602 and S603 is an example and is not limited thereto. For example, the network device may first send the third identifier to the target terminal device, and then send one of the at least one first identifiers to the first terminal device. For another example, the network device may simultaneously send the third identifier to the target terminal device and one of the at least one first identifiers to the first terminal device.

[0178] S604: The first terminal device establishes a first connection with the target terminal device.

[0179] Wherein, the first connection is used to transmit data of emergency services. For the target terminal device, the target terminal device can establish the first connection according to the third identifier. For the first terminal device, the first terminal device can establish the first connection according to the first identifier corresponding to the target terminal device. For example, the target terminal device is a fourth terminal device (that is, there is a second connection between the target terminal device and the first terminal device), the first terminal device can release the second connection, and establish the first connection according to the first identifier corresponding to the target terminal device. For another example, the target terminal device is a fourth terminal device (that is, there is a second connection between the target terminal device and the first terminal device), the first terminal device can also retain the second connection, and establish the first connection according to the first identifier corresponding to the target terminal device. For another example, the target terminal device is a fourth terminal device (that is, there is a second connection between the target terminal device and the first terminal device), the first terminal device can also update the configuration information of the second connection according to the first identifier corresponding to the target terminal device to obtain the first connection, and stop transmitting data of non-emergency services. Wherein, updating can be understood as releasing the original configuration information and applying new configuration information. For example, the first terminal device may release the PDCP / RLC entity used for non-emergency services and perform a MAC layer reset.

[0180] Afterwards, the target terminal device may receive emergency service data from the first terminal device based on the first connection and forward the data to the network device. Alternatively, the target terminal device receives emergency service data from the network device and forwards the data to the first terminal device through the first connection.

[0181] It should be pointed out that in Figure 6 In the illustrated embodiment, the first terminal device may communicate directly with the network device through the Uu interface, or may communicate with the network device through the fourth terminal device, without limitation. For example, in S601, the first terminal device may send a first message to the network device through the Uu interface; or the first terminal device may send a first message to the fourth terminal device through the PC5 interface, and the fourth terminal device may forward the first message to the network device through the Uu interface.

[0182] In S601, the first terminal device may send a first message to the network device when there is data of an emergency service to be transmitted. In another possible case, the first terminal device may also send a first message to the network device when the measurement result meets the measurement reporting condition.

[0183] Figure 7 FIG. 2 is a flow chart of another communication method provided by an embodiment of the present application. In this embodiment, the first terminal device sends a first message to the network device when the measurement result meets the measurement reporting condition. Figure 7 As shown, the method may include the following contents.

[0184] Among them, S701 and S702 are optional steps. Figure 7 Indicated by dotted line.

[0185] S701: The sixth terminal device sends the fifth identifier and / or the sixth identifier to the network device.

[0186] Accordingly, the network device receives the fifth identifier and / or the sixth identifier from the sixth terminal device. For example, the DU receives the fifth identifier and / or the sixth identifier from the sixth terminal device, and sends the fifth identifier and / or the sixth identifier to the CU for processing.

[0187] The sixth terminal device processes the connection state. The fifth identifier is an identifier of the sixth terminal device for providing relay services for emergency services. The sixth identifier is an identifier of the sixth terminal device for providing relay services for non-emergency services. For details, please refer to the relevant description of S601, which will not be repeated here.

[0188] Optionally, the sixth terminal device may be a target terminal device. Figure 7 In the example, the sixth terminal device is not the target terminal device. Optionally, the sixth terminal device may be the second terminal device.

[0189] S702: The first terminal device sends a third identifier to the network device.

[0190] Correspondingly, the network device receives the third identifier from the first terminal device. For example, the DU receives the third identifier from the first terminal device and sends the third identifier to the CU for processing.

[0191] The third identifier is an identifier of the first terminal device for emergency services. Optionally, the first terminal device may also send a fourth identifier to the network device, where the fourth identifier is an identifier of the first terminal device for non-emergency services; accordingly, the network device receives the fourth identifier. Figure 7 In the example, the first terminal device sends the third identifier and the fourth identifier to the network device.

[0192] Optionally, the first terminal device may send a third identifier to the network device through a fourth terminal device. Figure 7 Not shown in the figure, no limitation is given.

[0193] It should be noted that the execution order of S701 and S702 is only an example, and the embodiments of the present application are not limited thereto.

[0194] S703: The network device sends measurement configuration information to the first terminal device. For example, the CU determines the measurement configuration information for the first terminal device and sends the measurement configuration information to the DU. After receiving the measurement configuration information, the DU sends the measurement configuration information to the first terminal device.

[0195] Correspondingly, the first terminal device receives the measurement configuration information from the network device.

[0196] For a description of the measurement configuration information, please refer to the relevant description of S601, which will not be repeated here.

[0197] Optionally, the measurement configuration information may include first indication information, which instructs the first terminal device to measure the second terminal device, or the first indication information instructs the first terminal device to measure the relay terminal device supporting emergency services. In this way, the first terminal device can only measure the relay terminal device supporting emergency services according to the first indication information, and report the measurement results of the relay terminal device supporting emergency services, which can reduce the measurement complexity and reduce the overhead of reporting the measurement results.

[0198] Optionally, the network device may send the measurement configuration information to the first terminal device through the fourth terminal device. Figure 7 Not shown in the figure, no limitation is given.

[0199] S704: The first terminal device measures at least one relay terminal device corresponding to the measurement configuration information to obtain a measurement result.

[0200] For example, the first terminal device measures all relay terminal devices corresponding to the measurement configuration information to obtain measurement results. Alternatively, the measurement configuration information includes first indication information, and the first terminal device measures the relay terminal device (i.e., the second terminal device) that supports emergency services in at least one relay terminal device corresponding to the measurement configuration information to obtain measurement results. Alternatively, the first terminal device has data for emergency services to be transmitted, and the first terminal device can measure the relay terminal device that supports emergency services in at least one relay terminal device corresponding to the measurement configuration information to obtain measurement results.

[0201] When the measurement result meets the measurement reporting condition, the first terminal device may send a first message to the network device, that is, execute the content of S705. The measurement reporting condition may be, for example, that the link quality between the first terminal device and a relay terminal device is higher than a set threshold, which is not limited.

[0202] S705: The first terminal device sends a first message to the network device.

[0203] Accordingly, the network device receives the first message from the first terminal device. For example, the DU receives the first message from the first terminal device and forwards the first message to the CU so that the CU processes the first message.

[0204] In this embodiment, the first message includes a measurement result, at least one first identifier and an indication field of the first identifier. For example, the first message is a measurement report message, or is carried in a measurement report message, without limitation. The first identifier is an identifier of the second terminal device used to provide relay services for emergency services. The indication field of the first identifier is used to indicate that the second terminal device supports emergency services. The first identifier and the indication field of the first identifier can refer to the relevant content of S601 and will not be repeated here. It should be understood that the second terminal device is included in at least one relay terminal device measured by the first terminal device.

[0205] Optionally, the first message may also include at least one second identifier. The second identifier is an identifier of the third terminal device used to provide relay service for non-emergency services. Optionally, the first message does not include an indication field for the second identifier, and the first message may indicate that the third terminal device supports non-emergency services; or, the first message includes an indication field for the second identifier, and the indication field for the second identifier is used to indicate that the third terminal device supports non-emergency services. The second identifier and the indication field of the second identifier can refer to the relevant content of S601 and will not be repeated here. It should be understood that the third terminal device is included in at least one relay terminal device measured by the first terminal device.

[0206] Optionally, the first terminal device may send the first message to the network device through the fourth terminal device. Figure 7 Not shown in the figure, no limitation is given.

[0207] S706: The network device sends a first identifier of at least one first identifier to the first terminal device.

[0208] Correspondingly, the first terminal device receives the first identifier from the network device.

[0209] One first identifier among the at least one first identifier can be carried in an RRC reconfiguration message, that is, the network device sends an RRC reconfiguration message to the first terminal device, and the RRC reconfiguration message includes the one first identifier. The embodiment of the present application does not limit the specific implementation method of the network device sending a first identifier to the first terminal device. For example, the CU generates an RRC reconfiguration message, and the RRC reconfiguration message includes one first identifier among the at least one first identifier, and sends the RRC reconfiguration message to the DU. Furthermore, the DU sends the RRC reconfiguration message to the first terminal device. Please refer to S602 for the specific implementation process of S706, which will not be repeated.

[0210] Optionally, the network device may send the first identifier to the first terminal device through the fourth terminal device. Figure 7 Not shown in the figure, no limitation is given.

[0211] S707: The network device sends a third identifier to the target terminal device.

[0212] Correspondingly, the target terminal device receives the third identifier from the network device.

[0213] The third identifier is an identifier used by the first terminal device for emergency services. The third identifier can be carried in an RRC reconfiguration message, that is, the network device sends an RRC reconfiguration message to the target terminal device, and the RRC reconfiguration message includes the third identifier. The embodiment of the present application does not limit the specific implementation method of the network device sending the third message to the target terminal device. For example, the CU generates an RRC reconfiguration message, the RRC reconfiguration message includes the third identifier, and sends the RRC reconfiguration message to the DU. Furthermore, the DU sends the RRC reconfiguration message to the target terminal device.

[0214] It should be understood that the execution order of S706 and S707 is an example and is not limited thereto. For example, the network device may first send the third identifier to the target terminal device, and then send one of the at least one first identifier to the first terminal device. For another example, the network device may simultaneously send the third identifier to the target terminal device and one of the at least one first identifier to the first terminal device.

[0215] S708: The first terminal device establishes a first connection with the target terminal device.

[0216] Among them, the first connection is used to transmit data of emergency services. For the target terminal device, the target terminal device can establish the first connection according to the third identifier. For the first terminal device, the first terminal device can establish the first connection according to the first identifier corresponding to the target terminal device. For example, the target terminal device is a fourth terminal device (that is, there is a second connection between the target terminal device and the first terminal device), the first terminal device can release the second connection, and establish the first connection according to the first identifier corresponding to the target terminal device. For another example, the target terminal device is a fourth terminal device (that is, there is a second connection between the target terminal device and the first terminal device), the first terminal device can also retain the second connection, and establish the first connection according to the first identifier corresponding to the target terminal device. For another example, the target terminal device is a fourth terminal device (that is, there is a second connection between the target terminal device and the first terminal device), the first terminal device can also update the configuration information of the second connection according to the first identifier corresponding to the target terminal device (for example, including the identifier of the fourth terminal device for providing relay services for non-emergency services) to obtain the first connection, and stop transmitting data of non-emergency services.

[0217] Afterwards, the target terminal device may receive emergency service data from the first terminal device based on the first connection and forward the data to the network device. Alternatively, the target terminal device receives emergency service data from the network device and forwards the data to the first terminal device through the first connection.

[0218] It should be pointed out that in Figure 7 In the illustrated embodiment, the first terminal device may communicate directly with the network device through the Uu interface, or may communicate with the network device through the fourth terminal device, without limitation. For example, in S703, the network device may send measurement configuration information to the first terminal device through the Uu interface; or the network device may send measurement configuration information to the fourth terminal device through the Uu interface, and the fourth terminal device may forward the measurement configuration information to the first terminal device through the PC5 interface.

[0219] exist Figure 6 In the illustrated embodiment, the first terminal device may send a first message to the network device when there is data of an emergency service to be transmitted. Figure 7 In the illustrated embodiment, the first terminal device may send a first message to the network device when the measurement result meets the measurement reporting condition. In another possible case, the first terminal device may also send the first message to the network device according to the second message of the network device.

[0220] Figure 8FIG. 2 is a flow chart of another communication method provided by an embodiment of the present application. In this embodiment, a first terminal device sends a first message to a network device according to a second message of the network device. Figure 8 As shown, the method may include the following contents.

[0221] Among them, S801 and S802 are optional steps. Figure 8 Indicated by dotted line.

[0222] S801: The sixth terminal device sends the fifth identifier and / or the sixth identifier to the network device.

[0223] Accordingly, the network device receives the fifth identifier and / or the sixth identifier from the sixth terminal device. For example, the DU receives the fifth identifier and / or the sixth identifier from the sixth terminal device, and sends the fifth identifier and / or the sixth identifier to the CU for processing.

[0224] The sixth terminal device processes the connection state. The fifth identifier is an identifier of the sixth terminal device for providing relay services for emergency services. The sixth identifier is an identifier of the sixth terminal device for providing relay services for non-emergency services. For details, please refer to the relevant description of S601, which will not be repeated here.

[0225] Optionally, the sixth terminal device may be a target terminal device. Figure 8 In the example, the sixth terminal device is used as the target terminal device, and the target terminal device sends the fifth identifier to the network device. Optionally, the target terminal device may also send the sixth identifier to the network device.

[0226] S802: The first terminal device sends a third identifier to the network device.

[0227] Correspondingly, the network device receives the third identifier from the first terminal device. For example, the DU receives the third identifier from the first terminal device and sends the third identifier to the CU for processing.

[0228] The third identifier is an identifier of the first terminal device for emergency services. Optionally, the first terminal device may also send a fourth identifier to the network device, where the fourth identifier is an identifier of the first terminal device for non-emergency services; accordingly, the network device receives the fourth identifier. Figure 8 In the example, the first terminal device sends the third identifier and the fourth identifier to the network device.

[0229] Optionally, the first terminal device may send a third identifier to the network device via a fourth terminal device. Figure 8 It is used to represent circles without restriction.

[0230] S803: The first terminal device sends second indication information to the core network device.

[0231] Correspondingly, the core network device receives the second indication information from the first terminal device.

[0232] Figure 8 In the example, the core network device is AMF. That is, the first terminal device sends the second indication information to AMF; correspondingly, AMF receives the second indication information from the first terminal device.

[0233] For example, the first terminal device may send a second indication message to the core network device through the network device. The second indication message indicates that a fourth terminal device needs to be switched, and the fourth terminal device provides a relay service for the first terminal device, that is, the first terminal device communicates with the network device through the fourth terminal device. The second indication message may be carried in a fourth message, and the fourth message may be, for example, a service request message, which is not limited. For example, the first terminal device sends a service request message to the core network device, and the service request message may be used to indicate that an emergency services fallback is required. The service request message includes the second indication message, and the second indication message indicates that a fourth terminal device needs to be switched.

[0234] Optionally, the reason for the first terminal device to switch to the fourth terminal device may be that the fourth terminal device supports emergency services, a connection (such as a second connection) for transmitting data of non-emergency services is established between the first terminal device and the fourth terminal device, and the first terminal device has emergency service data to be transmitted; or the fourth terminal device does not support emergency services, and the first terminal device has emergency service data to be transmitted; or the fourth terminal device supports emergency services, the first terminal device has emergency service data to be transmitted, the fourth terminal device establishes a connection for transmitting data of emergency services with the first terminal device, and the reference signal received power (RSRP) between the fourth terminal device and the first terminal device is less than a set threshold, etc.

[0235] It should be noted that the execution order of S801, S802 and S803 is only an example, and the embodiments of the present application are not limited thereto.

[0236] S804: The core network device sends third indication information to the network device.

[0237] Correspondingly, the network device receives the third indication information from the core network device. For example, the CU receives the third indication information from the core network device.

[0238] Figure 8In the example, the core network device is AMF. That is, AMF sends the third indication information to the network device; accordingly, the network device receives the third indication information from AMF. For example, CU receives the third indication information from AMF.

[0239] The third indication information instructs the network device to configure a fifth terminal device for the first terminal device, and the fifth terminal supports emergency services and has the ability to provide relay services for the first terminal device. In other words, the third indication information instructs the network device to configure a relay terminal device that supports emergency services for the first terminal device. The third indication information can be carried in a fifth message, and the fifth message is, for example, an emergency services fallback request message, without limitation. For example, the core network device sends an emergency services fallback request message to the network device based on the second indication information, and the emergency services fallback request message includes the third indication information.

[0240] S805: The network device sends a second message to the first terminal device.

[0241] Correspondingly, the first terminal device receives the second message from the network device.

[0242] Exemplarily, the network device sends a second message to the first terminal device according to the third indication information. The second message is used to request the first terminal device to send the first message, or the second message is used to request the first terminal device to send the measurement result. For example, the CU generates a second message according to the third indication information, sends the second message to the DU, and after the DU receives the second message, it sends the second message to the first terminal device.

[0243] Optionally, the network device may send the second message to the first terminal device through the fourth terminal device. Figure 8 It is used to represent circles without restriction.

[0244] S806: The first terminal device measures at least one relay terminal device to obtain a measurement result.

[0245] The at least one relay terminal device may be all relay terminal devices corresponding to the measurement configuration information. For example, the first terminal device may also receive the measurement configuration information from the network device ( Figure 8 (not shown), according to the second message, all relay terminal devices corresponding to the measurement configuration information are measured to obtain measurement results.

[0246] Alternatively, the at least one relay terminal device may be a relay terminal device supporting emergency services corresponding to the measurement configuration information. For example, the first terminal device may also receive measurement configuration information from the network device ( Figure 8 (not shown), according to the second message, the relay terminal device supporting the emergency service corresponding to the measurement configuration information is measured to obtain a measurement result. For another example, the first terminal device may also receive measurement configuration information ( Figure 8 (not shown), the measurement configuration information includes first indication information, and according to the second message and the first indication information, the relay terminal device supporting emergency services corresponding to the measurement configuration information is measured to obtain a measurement result.

[0247] Alternatively, the at least one relay terminal device may be all relay terminal devices discovered by the first terminal device in the discovery process. For example, the first terminal device discovers at least one relay terminal device in the discovery process, and measures the at least one relay terminal device according to the second message to obtain a measurement result.

[0248] Alternatively, the at least one relay terminal device may be a relay terminal device supporting emergency services discovered by the first terminal device in the discovery process. For example, the first terminal device discovers at least one relay terminal device supporting emergency services in the discovery process, and measures the at least one relay terminal device supporting emergency services according to the second message to obtain a measurement result.

[0249] It should be pointed out that the embodiment of the present application does not limit or restrict the discovery process of the first terminal device.

[0250] S807: The first terminal device sends a first message to the network device.

[0251] Accordingly, the network device receives the first message from the first terminal device. For example, the DU receives the first message from the first terminal device and forwards the first message to the CU so that the CU processes the first message.

[0252] In this embodiment, the first message includes a measurement result, at least one first identifier and an indication field of the first identifier. For example, the first message is a measurement report message, or is carried in a measurement report message, without limitation. The first identifier is an identifier of the second terminal device used to provide relay services for emergency services. The indication field of the first identifier is used to indicate that the second terminal device supports emergency services. The first identifier and the indication field of the first identifier can refer to the relevant content of S601 and will not be repeated here. It should be understood that the second terminal device is included in at least one relay terminal device measured by the first terminal device.

[0253] Optionally, the first message may also include at least one second identifier. The second identifier is an identifier of the third terminal device used to provide relay service for non-emergency services. Optionally, the first message does not include an indication field for the second identifier, and the first message may indicate that the third terminal device supports non-emergency services; or, the first message includes an indication field for the second identifier, and the indication field for the second identifier is used to indicate that the third terminal device supports non-emergency services. The second identifier and the indication field of the second identifier can refer to the relevant content of S601 and will not be repeated here. It should be understood that the third terminal device is included in at least one relay terminal device measured by the first terminal device.

[0254] Optionally, the first terminal device may send the first message to the network device through the fourth terminal device. Figure 8 It is used to represent circles without restriction.

[0255] S808: The network device sends a first identifier of at least one first identifier to the first terminal device.

[0256] Correspondingly, the first terminal device receives the first identifier from the network device.

[0257] One first identifier among the at least one first identifier can be carried in an RRC reconfiguration message, that is, the network device sends an RRC reconfiguration message to the first terminal device, and the RRC reconfiguration message includes the one first identifier. The embodiment of the present application does not limit the specific implementation method of the network device sending a first identifier to the first terminal device. For example, the CU generates an RRC reconfiguration message, and the RRC reconfiguration message includes one first identifier among the at least one first identifier, and sends the RRC reconfiguration message to the DU. Furthermore, the DU sends the RRC reconfiguration message to the first terminal device. Please refer to S602 for the specific implementation process of S706, which will not be repeated.

[0258] Optionally, the network device may send the first identifier to the first terminal device through the fourth terminal device. Figure 8 It is used to represent circles without restriction.

[0259] In this embodiment, the target terminal device is the sixth terminal device, and the first identifier is the fifth identifier. Figure 8 In the example, the first identifier is used as the fifth identifier.

[0260] S809: The network device sends a third identifier to the target terminal device.

[0261] Correspondingly, the target terminal device receives the third identifier from the network device.

[0262] The third identifier is an identifier used by the first terminal device for emergency services. The third identifier can be carried in an RRC reconfiguration message, that is, the network device sends an RRC reconfiguration message to the target terminal device, and the RRC reconfiguration message includes the third identifier. The embodiment of the present application does not limit the specific implementation method of the network device sending the third message to the target terminal device. For example, the CU generates an RRC reconfiguration message, the RRC reconfiguration message includes the third identifier, and sends the RRC reconfiguration message to the DU. Furthermore, the DU sends the RRC reconfiguration message to the target terminal device.

[0263] It should be understood that the execution order of S808 and S809 is an example and is not limited thereto. For example, the network device may first send the third identifier to the target terminal device, and then send one of the at least one first identifier to the first terminal device. For another example, the network device may simultaneously send the third identifier to the target terminal device and one of the at least one first identifier to the first terminal device.

[0264] S810: The first terminal device releases the connection with the fourth terminal device.

[0265] Optionally, the first terminal device may release the second connection with the fourth terminal device, or may retain the connection with the fourth terminal device, without limitation.

[0266] S811: The first terminal device establishes a first connection with the target terminal device.

[0267] The first connection is used to transmit emergency service data. For the target terminal device, the target terminal device can establish the first connection according to the third identifier. For the first terminal device, the first terminal device can establish the first connection according to the first identifier (ie, the fifth identifier) ​​corresponding to the target terminal device.

[0268] It should be understood that the execution order of S810 and S811 is only an example, and the embodiments of the present application are not limited thereto.

[0269] It should be pointed out that in Figure 8 In the illustrated embodiment, the first terminal device may communicate directly with the network device via a Uu interface, or may communicate with the network device via a fourth terminal device, without limitation.

[0270] Afterwards, the target terminal device may receive emergency service data from the first terminal device based on the first connection and forward the data to the network device. Alternatively, the target terminal device receives emergency service data from the network device and forwards the data to the first terminal device through the first connection.

[0271] In the above Figures 6 to 8 In any of the embodiments shown in , the first terminal device sends at least one first identifier and an indication field of the first identifier to the network device. In another possible implementation, the first terminal device may send the at least one first identifier to the network device without sending the indication field of the first identifier.

[0272] Fig. 9 The flowchart of another communication method provided by the embodiment of the present application is exemplarily shown. In this embodiment, the first terminal device sends at least one first identifier to the network device.

[0273] Among them, compared with Figure 6 The embodiment shown, Fig. 9 S902, S903, and S904 in the embodiment shown are respectively Figure 6 S602, S603, and S604 in the illustrated embodiment are the same, except that:

[0274] S901: A first terminal device sends at least one first identifier to a network device.

[0275] Accordingly, the network device receives at least one first identifier from the first terminal device. For example, the DU receives at least one first identifier from the first terminal device and forwards the at least one first identifier to the CU so that the CU processes the at least one first identifier.

[0276] Among them, at least one first identifier is, for example, at least one L2 ID. The first identifier is an identifier of the second terminal device used to provide relay service for emergency services, or is expressed as the first identifier is an identifier of the second terminal device used for emergency services, or is expressed as the first identifier is an identifier of the second terminal device used to forward data for emergency services. For details, please refer to the description of S601, which will not be repeated here. In this embodiment, the second terminal device is a terminal device that supports emergency services. In other words, in this embodiment, the first terminal device reports the identifier of the second terminal device used for emergency services, which can be understood as the first terminal device only reporting the identifier of the relay terminal device that supports emergency services. In this embodiment, at least one first identifier can be carried in a measurement report message, or at least one first identifier can also be carried in the UAI, without limitation.

[0277] In one implementation, the first terminal device may send at least one first identifier to the network device. For example, when there is emergency service data to be transmitted, the first terminal device may actively send at least one first identifier to the network device. For another example, the network device may send measurement configuration information to the first terminal device. For the description of the measurement configuration information, please refer to the aforementioned content and will not repeat it; the first terminal device receives the measurement configuration information, measures at least one relay terminal device corresponding to the measurement configuration information, and obtains a measurement result; when the measurement result meets the measurement reporting condition, the first terminal device may send a measurement report message to the network device, and the measurement report message includes at least one first identifier. The specific implementation process may refer to Figure 7 or Figure 8 The relevant contents in the illustrated embodiments will not be repeated here. The measurement reporting condition may be, for example, that the link quality between the first terminal device and a relay terminal device is higher than a set threshold, without limitation. In this embodiment, the measurement report message only carries the measurement results of the relay terminal device that supports emergency services, that is, the measurement report message only carries the measurement results of the second terminal device. In other words, when the measurement result meets the measurement reporting condition, the first terminal device sends the measurement result of the second terminal device (including at least one first identifier) ​​to the network device. The measurement result may also include, but is not limited to, one or more of the following: an identifier of a serving cell, or link quality, etc.

[0278] For example, the first terminal device measures multiple relay terminal devices corresponding to the measurement configuration information, and obtains the measurement results of the multiple relay terminal devices, for example, respectively recorded as the measurement results of relay UE1, the measurement results of relay UE2, and the measurement results of relay UE3. Among them, relay UE1 and relay UE2 do not support emergency services, and relay UE3 supports emergency services. Then, when the measurement result meets the measurement reporting conditions, the first terminal device can send the measurement result of relay UE3 to the network device, and the measurement result of relay UE3 includes the L2 ID of the relay UE3 used for emergency services. It should be pointed out that relay UE3 can use different L2 IDs to send a discovery message carrying an RSC for non-emergency services and a discovery message carrying an RSC for emergency services, so that the first terminal device may obtain two measurement results of relay UE3, one measurement result corresponds to the L2 ID for non-emergency services, and the remaining measurement result corresponds to the L2 ID for emergency services. In this case, the first terminal device may send the L2 ID of relay UE3 for emergency services to the network device when sending the measurement result of relay UE3 to the network device. For example, the first terminal device may send the measurement result corresponding to the L2 ID of relay UE3 for emergency services to the network device, and the measurement result includes the L2 ID for emergency services.

[0279] In one embodiment, the first terminal device can send at least one first identifier to the network device according to the sixth message of the network device. The sixth message can be used to request the first terminal device to send at least one first identifier, or the sixth message can be used to request the first terminal device to send a measurement result. Optionally, the sixth message can be sent by the network device in response to the seventh message of the core network device (such as AMF, not limited), and the seventh message can be used to request to establish a first session, and the first session is used for emergency services. The first session can be, for example, a PDU session. For example, the core network device can send the seventh message to the network device; the network device receives the seventh message, and sends the sixth message to the first terminal device according to the seventh message.

[0280] In one example, the seventh message may be sent by the core network device in response to the twelfth message of the first terminal device, and the twelfth message may be used to request the establishment of the first session. Exemplarily, the first terminal device may send the twelfth message to the core network device, such as sending the twelfth message to the core network device through the network device. For example, the first terminal device sends a relay terminal device that supports emergency services in the sending process, or there are relay terminal devices that support emergency services around the first terminal device, and the first terminal device may send the twelfth message to the core network device. Correspondingly, the core network device receives the twelfth message through the network device, and sends the seventh message to the network device according to the twelfth message. Optionally, the seventh message may include a response message to the twelfth message. The response message to the twelfth message may be used to indicate acceptance of the establishment of the first session, such as a session establishment acceptance message; or, the response message to the twelfth message may also be used to indicate refusal to establish the first session, such as a session establishment rejection message. The embodiment of the present application takes acceptance of the establishment of the first session as an example. It should be understood that if there is no relay terminal device supporting emergency services around the first terminal device, the first terminal device may not send the twelfth message to the core network device, that is, it does not initiate the establishment of a session for emergency services.

[0281] In one example, the sixth message may include measurement configuration information, or may not include measurement configuration information, without limitation. For example, after receiving the sixth message, the first terminal device measures the relay terminal device supporting emergency services corresponding to the measurement configuration information according to the sixth message, obtains the measurement result, and sends the measurement result (including at least one first identifier) ​​of the relay terminal device supporting emergency services to the network device.

[0282] In one example, there may be no relay terminal devices supporting emergency services around the first terminal device, so the measurement report message sent by the first terminal device to the network device does not include relevant information about the relay terminal devices supporting emergency services. In this case, if the network device sends a response message to the seventh message to the core network device before receiving the measurement report message from the first terminal device, the response message to the seventh message is used to indicate acceptance of establishing the first session, and the network device can also send indication information for releasing the first session to the core network device based on the measurement report message. Alternatively, if the network device has not sent a response message to the seventh message to the core network device before receiving the measurement report message from the first terminal device, the network device can send a response message to the seventh message to the core network device based on the measurement report message. At this time, the response message to the seventh message is used to indicate refusal to establish the first session.

[0283] In another implementation, the first terminal device may send at least one first identifier to the network device according to a trigger condition. For example, the network device may send an eighth message to the first terminal device. The eighth message may be, for example, an RRC reconfiguration message, without limitation. The eighth message includes a trigger condition for sending at least one first identifier, and the trigger condition may include data of emergency services to be transmitted by the first terminal device; the first terminal device receives the eighth message from the network device, and in response to the trigger condition, sends at least one first identifier to the network device when there is data of emergency services to be transmitted. Optionally, the eighth message may include measurement configuration information, or may not include measurement configuration information, without limitation. For the description of the measurement configuration information, please refer to the aforementioned content, which will not be repeated.

[0284] The trigger condition may be, for example, a measurement report trigger event, and the measurement report trigger time is the data of the emergency service to be transmitted by the first terminal device. For example, the first terminal device receives measurement configuration information and a measurement report trigger event from a network device, measures at least one relay terminal device according to the measurement configuration information, and in response to the measurement report trigger event, sends a measurement result and at least one first identifier to the network device when there is data of the emergency service to be transmitted. The measurement result can refer to the aforementioned content and will not be repeated here.

[0285] Alternatively, the trigger condition may also be indication information, which is carried in other configuration (otherconfig) information elements and is used to instruct the first terminal device to send at least one first identifier when there is data of emergency service to be transmitted, such as sending the at least one first identifier through UAI. For example, the first terminal device receives measurement configuration information and other config information elements from the network device, measures at least one relay terminal device according to the measurement configuration information, and in response to the indication information in the other config information element, when there is data of emergency service to be sent, sends at least one first identifier and measurement result to the network device through UAI. For another example, the first terminal device receives otherconfig information elements from the network device, determines information of at least one terminal device supporting emergency service through a discovery process, and in response to the indication information in the other config information element, sends at least one first identifier to the network device through UAI when there is data of emergency service to be sent.

[0286] It should be noted that the first terminal device can communicate directly with the network device through the Uu interface, or can also communicate with the network device through the fourth terminal device, without limitation. For example, the network device can send measurement configuration information to the first terminal device through the Uu interface; or the network device can also send measurement configuration information to the fourth terminal device through the Uu interface, and the fourth terminal device then forwards the measurement configuration information to the first terminal device through the PC5 interface.

[0287] In a possible implementation, the first terminal device may also send at least one identifier of the first terminal device to the network device, such as sending at least one identifier of the first terminal device to the network device before S901; accordingly, the network device receives at least one identifier of the first terminal device. The at least one identifier of the first terminal device includes the third identifier, or includes the fourth identifier, or includes the third identifier and the fourth identifier. For details, please refer to the description of S601, which will not be repeated here.

[0288] In one possible implementation, the sixth terminal device may send at least one identifier of the sixth terminal device to the network device; accordingly, the network device receives at least one identifier of the sixth terminal device. Optionally, the at least one identifier of the sixth terminal device is carried in the SUI without limitation. The sixth terminal device is in a connected state and has the ability to provide relay services for the first terminal device. The at least one identifier of the sixth terminal device includes the fifth identifier, or includes the sixth identifier, or includes the fifth identifier and the sixth identifier. For details, please refer to the description of S601 and will not be repeated here.

[0289] exist Fig. 9 In the illustrated embodiment, a first terminal device sends at least one first identifier to a network device, where the first identifier is an identifier of a second terminal device used to provide relay service for emergency services, enabling the network device to configure a relay terminal device that supports emergency services for the first terminal device based on the at least one first identifier, thereby ensuring that data for the emergency services can be transmitted normally.

[0290] In the above Figures 6 to 9 In any of the embodiments shown in , the target terminal device may be in a connected state or in a non-connected state (or an idle state). For example, the target terminal device may be in a connected state before establishing the first connection, or the target terminal device may be in a non-connected state (or an idle state) before establishing the first connection. If the target terminal device is in a non-connected state (or an idle state), the target terminal device needs to establish a connection with the network device, such as being recorded as a third connection.

[0291] Fig.10The flowchart of another communication method provided by the embodiment of the present application is exemplarily shown. In this embodiment, the target terminal device is in a non-connected state (or an idle state), and the target terminal device establishes a third connection with the network device.

[0292] S1001: A network device sends a first identifier among at least one first identifier to a first terminal device.

[0293] Correspondingly, the first terminal device receives the first identifier from the network device.

[0294] Among them, please refer to the aforementioned content for the description of at least one first identifier, which will not be repeated here. One of the at least one first identifier can be carried in an RRC reconfiguration message, that is, the network device sends an RRC reconfiguration message to the first terminal device, and the RRC reconfiguration message includes the one first identifier. The embodiment of the present application does not limit the specific implementation method of the network device sending a first identifier to the first terminal device. For example, the CU generates an RRC reconfiguration message, which includes one of the at least one first identifier, and sends the RRC reconfiguration message to the DU. Furthermore, the DU sends the RRC reconfiguration message to the first terminal device. Please refer to S602 for the specific implementation process of S1001, which will not be repeated here.

[0295] Optionally, the network device may send the first identifier to the first terminal device via a fourth terminal device. The fourth terminal device may refer to the aforementioned content and will not be described in detail.

[0296] Optionally, the target terminal device may be replaced by a sixth terminal device, and accordingly, S1001 may be replaced by: the network device sends a fifth identifier to the first terminal device; accordingly, the first terminal device receives the fifth identifier from the network device.

[0297] S1002: The first terminal device sends a ninth message to the target terminal device.

[0298] Correspondingly, the target terminal device receives the ninth message from the first terminal device.

[0299] Among them, the ninth message can be used to request to establish the first connection. For example, the first terminal device can send the ninth message to the target terminal device during the process of establishing the first connection with the target terminal device. The ninth message can be, for example, a direct communication request (DCR) message, without limitation. The ninth message may include an RSC for emergency services, so that the target terminal device can determine that the first connection is used for emergency services through the RSC. The source identifier used to send the ninth message is the third identifier, that is, the first terminal device uses the third identifier as the source identifier to send the ninth message to the target terminal device. The third identifier is an identifier of the first terminal device for emergency services. The source identifier can be understood as a source identifier carried in the MAC layer during the SL communication process, such as a source L2 ID. Exemplarily, if before S1002, the first terminal device sends a third identifier to the network device, the first terminal device uses the third identifier as the source identifier to send the ninth message to the target terminal device; or, if before S1002, the first terminal device sends a third identifier and a fourth identifier to the network device, and the fourth identifier is an identifier used by the first terminal device for non-emergency services, the first terminal device uses the third identifier as the source identifier to send the ninth message to the target terminal device.

[0300] Optionally, the target terminal device may be replaced by a sixth terminal device, and accordingly, S1002 may be replaced by: the first terminal device sends a ninth message to the sixth terminal device; accordingly, the sixth terminal device receives the ninth message from the first terminal device.

[0301] S1003: The first terminal device sends a tenth message to the target terminal device.

[0302] Correspondingly, the target terminal device receives the tenth message from the first terminal device.

[0303] The tenth message may be, for example, an RRC reconfiguration completion message, which is a response message to the RRC reconfiguration message. The source identifier used to send the tenth message is the third identifier, and specific reference may be made to the description of S1002, which will not be repeated here. Exemplarily, the tenth message may be sent by the first terminal device in response to a first identifier of the network device, or the tenth message may be sent by the first terminal device in response to a fifth identifier of the network device.

[0304] Optionally, the target terminal device may be replaced by a sixth terminal device, and accordingly, S1003 may be replaced by: the first terminal device sends the tenth message to the sixth terminal device; accordingly, the sixth terminal device receives the tenth message from the first terminal device.

[0305] S1004: The target terminal device sends an eleventh message to the network device.

[0306] Accordingly, the network device receives the eleventh message from the target terminal device. For example, the DU receives the eleventh message from the target terminal device and forwards the eleventh message to the CU so that the CU processes the eleventh message.

[0307] Among them, the eleventh message can be used to request the establishment of a third connection. The third connection is a connection between the target terminal device and the network device. The eleventh message can be, for example, an RRC configuration request (RRC setup request), without limitation. The eleventh message includes the establishment cause of the third connection, and the establishment cause includes emergency service or the establishment cause includes emergency. For example, the establishment cause is the emergency service, or the establishment cause is emergency. Exemplarily, after the target terminal device receives the ninth message, it can determine that the first connection is a connection for emergency service according to the RSC in the ninth message. Further, the target terminal device can determine that the establishment cause of establishing the third connection includes emergency service according to the third identifier; or, the target terminal device can determine that the establishment cause of establishing the third connection includes emergency service according to the association between the third identifier and the first connection. For example, the target terminal device can determine that the establishment cause of establishing the third connection includes emergency service according to the third identifier used to send the tenth message.

[0308] Optionally, the target terminal device may be replaced by a sixth terminal device, and S1004 may be replaced by: the sixth terminal device sends an eleventh message to the network device; correspondingly, the network device receives the eleventh message from the sixth terminal device.

[0309] The present embodiment of the application does not limit the process of establishing the third connection. After the third connection is established, the target terminal device may also send a tenth message to the network device, that is, execute the content of S1005.

[0310] S1005: The target terminal device sends a tenth message to the network device.

[0311] Accordingly, the network device receives the tenth message from the target terminal device. For example, the DU receives the tenth message from the target terminal device and forwards the tenth message to the CU so that the CU processes the tenth message.

[0312] S1005 is an optional step. Fig.10 After the third connection is established, the target terminal device may forward the tenth message from the first terminal device to the network device through the third connection.

[0313] Optionally, the target terminal device may be replaced by the sixth terminal device, and accordingly, S1005 may be replaced by: the sixth terminal device sends the tenth message to the network device; accordingly, the network device receives the tenth message from the sixth terminal device.

[0314] Optionally, after the third connection is established, the target terminal device is in a connected state, and the network device can configure the target terminal device to provide a relay service for the emergency service of the first terminal device through the third connection, so that the target terminal device forwards the emergency service data of the first terminal device to the network device, or forwards the emergency service data of the network device to the first terminal device. For example, the network device can send a third identifier to the target terminal device through the third connection, and the details can be referred to the aforementioned content, which will not be repeated here.

[0315] When the target terminal device is in a disconnected or idle state, Fig.10 In the illustrated embodiment, the target terminal device can correctly set the reason for establishing the third connection, and establish the third connection supporting the emergency service with the network device, thereby ensuring that the data of the emergency service can be transmitted normally.

[0316] In the embodiments provided in the present application, the method provided in the embodiments of the present application is introduced from the perspective of the interaction between the first terminal device, the network device, the sixth terminal device and the core network device. Among them, the steps performed by the first terminal device can be implemented by different functional entities constituting the first terminal device. The steps performed by the network device can be implemented by different functional entities constituting the network device. The steps performed by the sixth terminal device can be implemented by different functional entities constituting the sixth terminal device. The steps performed by the core network device can be implemented by different functional entities constituting the core network device. In order to implement the functions of the method provided in the above-mentioned embodiments of the present application, the first terminal device, the network device, the sixth terminal device and the core network device may include a hardware structure and / or a software module, and implement the above-mentioned functions in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether a certain function of the above-mentioned functions is executed in the form of a hardware structure, a software module, or a hardware structure plus a software module depends on the specific application and design constraints of the technical solution.

[0317] The following describes the communication device used to implement the above method in the embodiment of the present application in conjunction with the accompanying drawings. Therefore, the above contents can be used in subsequent embodiments, and repeated contents will not be repeated.

[0318] Fig.11 A schematic diagram of the structure of a communication device 1100 is shown. The communication device 1100 can implement the functions or steps implemented by the first terminal device, the network device, the sixth terminal device, or the core network device in the above-mentioned various method embodiments.

[0319] In a possible implementation, the communication device 1100 may include a processing module 1101 and a transceiver module 1102. The processing module 1101 is used to perform processing operations other than transceiver operations. For example, the processing module 1101 may be used to perform Figures 6 to 10 In any of the embodiments shown, the first terminal device, the network device, the sixth terminal device, and the core network device perform processing operations other than the transceiver operation. The transceiver module 1102 may also be referred to as a communication interface or a communication unit, etc., and is used to receive or send related data, information, or messages. For example, the transceiver module 1102 is used to perform Figures 6 to 10 The receiving operation and sending operation of the first terminal device, the network device, the sixth terminal device and the core network device in any of the illustrated embodiments.

[0320] In another possible implementation, the communication device 1100 may include a transceiver module 1102, which may also be referred to as a communication interface or a communication unit, etc., for receiving or sending relevant data, information or messages. For example, the transceiver module 1102 is used to perform Figures 6 to 10 The receiving operation and sending operation of the first terminal device, the network device, the sixth terminal device and the core network device in any of the illustrated embodiments.

[0321] It should be noted that the above modules may be independently configured or partially or completely integrated. For example, the transceiver module 1102 may include a sending module and a receiving module.

[0322] As an example, the communication device 1100 can implement the functions or steps implemented by the first terminal device in any of the above method embodiments. Among them, the transceiver module 1102 is used to send a first message to a network device, the first message includes at least one first identifier, the first identifier is an identifier of the second terminal device for providing relay services for emergency services, the first message also includes an indication field of the first identifier, the indication field of the first identifier is used to indicate that the second terminal device supports the emergency service; and receive a first identifier from the at least one first identifier of the network device. The processing module 1101 is used to establish a first connection between a target terminal device corresponding to the one first identifier, and the first connection is used to transmit data of the emergency service.

[0323] In a possible implementation, the value of the indication field of the first identifier includes a first value and a second value, and the value of the indication field of the first identifier is the first value, wherein the first value is used to indicate that the second terminal device supports the emergency service, and the second value is used to indicate that the second terminal device supports non-emergency service.

[0324] In a possible implementation, the first message also includes at least one second identifier, and the second identifier is an identifier of the third terminal device for providing relay services for non-emergency services. Furthermore, the first message does not include an indication field of the second identifier, and the first message is used to indicate that the third terminal device supports the non-emergency service; or, the first message also includes an indication field of the second identifier, and the value of the indication field of the second identifier includes a first value and a second value, and the value of the indication field of the second identifier is the second value, wherein the first value is used to indicate that the third terminal device supports the emergency service, and the second value is used to indicate that the third terminal device supports the non-emergency service. Optionally, a third terminal device and a second terminal device may be the same terminal device.

[0325] In one possible implementation, the transceiver module 1102 is also used to send at least one identifier of the first terminal device to the network device, and the at least one identifier includes a third identifier, or includes a third identifier and a fourth identifier, wherein the third identifier is an identifier of the first terminal device used for the emergency service, and the fourth identifier is an identifier of the first terminal device used for non-emergency service.

[0326] In a possible implementation, the transceiver module 1102 is further configured to receive first indication information from the network device, where the first indication information instructs the first terminal device to measure the second terminal device.

[0327] In a possible implementation, the transceiver module 1102 is further used to send a second indication information to the core network device, the second indication information indicating that a fourth terminal device needs to be switched, and the fourth terminal device provides a relay service for the first terminal device; and receive a second message from the network device, the second message being used to request the first terminal device to send the first message. Exemplarily, the second message is sent by the network device in response to a third indication information of the core network device, the third indication information indicating that a fifth terminal device is configured for the first terminal device, the fifth terminal device supports the emergency service and has the ability to provide a relay service for the first terminal device.

[0328] In another possible implementation, the transceiver module 1102 is further used to receive a third message from the network device, where the third message includes a trigger condition for sending the first message, and the trigger condition includes data of the emergency service to be transmitted by the first terminal device.

[0329] In a possible implementation manner, there is a second connection between the target terminal device and the first terminal device, and the second connection is used to transmit data of non-emergency services.

[0330] In one possible implementation, when establishing a first connection between a target terminal device corresponding to the first identifier, the processing module 1101 is specifically used to: release the second connection and establish the first connection based on the first identifier; or, update the configuration information of the second connection based on the first identifier to obtain the first connection, and stop transmitting the data of the non-emergency service.

[0331] As an example, the communication device 1100 can implement the functions or steps implemented by the first terminal device in any of the above method embodiments. Among them, the transceiver module 1102 is used to send at least one first identifier to the network device; and receive one of the at least one first identifier from the network device. The processing module 1101 is used to establish a first connection between the target terminal device corresponding to the one first identifier, and the first connection is used to transmit the data of the emergency service.

[0332] As another example, the communication device 1100 can implement the functions or steps implemented by the network device in any of the above method embodiments. Among them, the transceiver module 1102 is used to receive a first message from a first terminal device, the first message includes at least one first identifier, the first identifier is an identifier of the second terminal device for providing relay services for emergency services, and the first message also includes an indication field of the first identifier, the indication field of the first identifier is used to indicate that the second terminal device supports the emergency service; and send a first identifier of the at least one first identifier to the first terminal device, and send a third identifier to the target terminal device corresponding to the one first identifier, so that the first terminal device establishes a first connection with the target terminal device, the first connection is used to transmit data of the emergency service, and the third identifier is an identifier of the first terminal device used for the emergency service.

[0333] In a possible implementation, the value of the indication field of the first identifier includes a first value and a second value, and the value of the indication field of the first identifier is the first value, wherein the first value is used to indicate that the second terminal device supports the emergency service, and the second value is used to indicate that the second terminal device supports non-emergency service.

[0334] In a possible implementation, the first message also includes at least one second identifier, and the second identifier is an identifier used by the third terminal device to provide relay services for non-emergency services. Furthermore, the first message does not include an indication field of the second identifier, and the first message is used to indicate that the third terminal device supports the non-emergency service; or, the first message also includes an indication field of the second identifier, and the value of the indication field of the second identifier includes a first value and a second value, and the value of the indication field of the second identifier is the second value, wherein the first value is used to indicate that the third terminal device supports the emergency service, and the second value is used to indicate that the third terminal device supports the non-emergency service.

[0335] In a possible implementation, the transceiver module 1102 is also used to receive at least one identifier from the first terminal device, and the at least one identifier of the first terminal device includes the third identifier, or includes the third identifier and a fourth identifier, and the fourth identifier is an identifier of the first terminal device used for non-emergency services.

[0336] In one possible implementation, the transceiver module 1102 is also used to receive at least one identifier from a sixth terminal device, and the at least one identifier of the sixth terminal device includes a fifth identifier and / or a sixth identifier, the fifth identifier is an identifier of the sixth terminal device used to provide relay service for the emergency service, and the sixth identifier is an identifier of the sixth terminal device used to provide relay service for non-emergency service, wherein if the at least one identifier of the sixth terminal device includes the fifth identifier, the sixth terminal device is the second terminal device.

[0337] In a possible implementation, before receiving the first message from the first terminal device, the transceiver module 1102 is further used to send first indication information to the first terminal device, where the first indication information instructs the first terminal device to measure the second terminal device.

[0338] In one possible implementation, before receiving a first message from a first terminal device, the transceiver module 1102 is further used to receive a third indication information from a core network device, wherein the third indication information indicates that a fifth terminal device is configured for the first terminal device, and the fifth terminal device supports the emergency service and has the ability to provide a relay service for the first terminal device; and, according to the third indication information, send a second message to the first terminal device, wherein the second message is used to request the first terminal device to send the first message.

[0339] In one possible implementation, before receiving a first message from a first terminal device, the transceiver module 1102 is also used to send a third message to the first terminal device, wherein the third message includes a trigger condition for sending the first message, and the trigger condition includes data of the emergency service to be transmitted by the first terminal device.

[0340] As another example, the communication device 1100 can implement the functions or steps implemented by the network device in any of the above method embodiments. Among them, the transceiver module 1102 is used to receive at least one first identifier from a first terminal device, the first identifier being an identifier used by a second terminal device to provide relay services for emergency services; and to send a first identifier among the at least one first identifier to the first terminal device, and to send a third identifier to a target terminal device corresponding to the first identifier, so that the first terminal device establishes a first connection with the target terminal device, the first connection being used to transmit data of the emergency service, and the third identifier being an identifier used by the first terminal device for the emergency service.

[0341] As another example, the communication device 1100 can implement the functions or steps implemented by the sixth terminal device in any of the above method embodiments. The transceiver module 1102 is used to send at least one identifier to the network device, the at least one identifier includes a fifth identifier and / or a sixth identifier, the fifth identifier is an identifier of the sixth terminal device for providing relay services for emergency services, and the sixth identifier is an identifier of the sixth terminal device for providing relay services for non-emergency services.

[0342] In one possible implementation, the at least one identifier includes the fifth identifier, and the transceiver module 1102 is also used to receive a third identifier from the network device, where the third identifier is an identifier of the first terminal device used for the emergency service; the processing module 1101 is used to establish a first connection with the first terminal device based on the third identifier, and the first connection is used to transmit data of the emergency service.

[0343] In one possible implementation, the sixth terminal device establishes a first connection with the first terminal device, which can be specifically: the sixth terminal device receives a ninth message from the first terminal device, and the ninth message is used to request to establish the first connection, wherein the ninth message includes a relay service code for emergency services, and the source identifier used to send the ninth message is the third identifier.

[0344] In one possible implementation, the sixth terminal device may also send an eleventh message to the network device, where the eleventh message is used to request establishment of a third connection, where the third connection is a connection between the sixth terminal device and the network device, and the eleventh message includes a reason for establishing the third connection, which includes emergency services.

[0345] In a possible implementation, the sixth terminal device may also determine, based on the third identifier, that a reason for establishing the third connection includes an emergency service, and the third connection is a connection between the sixth terminal device and the network device.

[0346] As another example, the communication device 1100 can implement the functions or steps implemented by the core network device in any of the above method embodiments. The transceiver module 1102 is used to receive second indication information from the first terminal device, the second indication information indicates that a fourth terminal device needs to be switched, and the fourth terminal device provides a relay service for the first terminal device; and send third indication information to the network device, the third indication information indicates that a fifth terminal device is configured for the first terminal device, and the fifth terminal device supports the emergency service and has the ability to provide a relay service for the first terminal device.

[0347] Among them, a more detailed description can be directly referred to Figures 6 to 10 The relevant description in any of the method embodiments shown is directly obtained and will not be repeated here.

[0348] like Fig.12 As shown, an embodiment of the present application provides a schematic diagram of the structure of a communication device 1200. The communication device 1200 may include a processor 1220, which is used to implement or support the communication device 1200 to implement the functions of a terminal device (e.g., a first terminal device, or a sixth terminal device), a network device, or a core network device in any method embodiment of the present application. For details, please refer to the detailed description in the aforementioned method embodiment, which will not be repeated here. For example, the processor 1220 is used to read and execute program instructions through a communication interface so that the communication device 1200 implements the corresponding method. The processor 1220 may include one or more processors without limitation.

[0349] Specifically, the communication device 1200 can be a first terminal device or a functional module located in the first terminal device, which can implement the functions of the first terminal device in any method embodiment of the present application; or, the communication device 1200 can be a network device or a functional module located in the network device, which can implement the functions of the network device in any method embodiment of the present application; or, the communication device 1200 can be a sixth terminal device or a functional module located in the sixth terminal device, which can implement the functions of the sixth terminal device in any method embodiment of the present application; or, the communication device 1200 can be a core network device or a functional module located in the core network device, which can implement the functions of the core network device in any method embodiment of the present application.

[0350] It should be pointed out that the above-mentioned functional modules can be implemented by hardware or by a combination of hardware and software without limitation.

[0351] For example, the communication device 1200 may be a chip system, wherein the chip system may be composed of a chip, or may include a chip and other discrete devices, without limitation.

[0352] Optionally, the communication device 1200 may further include a memory 1230 for storing program instructions and / or data. The memory 1230 is coupled to the processor 1220. The coupling may be understood as an indirect coupling or communication connection between devices, units or modules, which may be electrical, mechanical or other forms, for information exchange between devices, units or modules. The processor 1220 may operate in coordination with the memory 1230. The memory 1230 may include one or more memories, without limitation.

[0353] Furthermore, the processor 1220 is configured to execute program instructions stored in the memory 1230 so that the communication device 1200 implements a corresponding method.

[0354] Among them, one or more memories in the memory 1230 may be included in the processor, and the memory 1230 may also exist independently, such as an off-chip memory, through a communication bus ( Fig.12 The memory 1230 and the processor 1220 may also be integrated together.

[0355] Optionally, the communication device 1200 further includes a communication interface 1210 ( Fig.12 The communication interface 1210 is used to communicate with other devices through a transmission medium, so that the device in the communication device 1200 can communicate with other devices. Exemplarily, when the communication device is a terminal device, the other device can be a network device, etc. The processor 1220 can use the communication interface 1210 to send and receive data.

[0356] The communication interface 1210 may specifically be a transceiver. Optionally, the device used to implement the receiving function in the transceiver may be called a receiving unit, and the device used to implement the sending function may be called a sending unit, that is, the transceiver includes a receiving unit and a sending unit. The receiving unit is sometimes also referred to as a receiver, a receiver, or a receiving circuit, etc. The sending unit is sometimes also referred to as a transmitter, a transmitter, or a transmitting circuit, etc. In hardware implementation, the transceiver can be used to implement the functions of the above-mentioned transceiver module 902, and the transceiver is integrated in the communication device 1200 to form the communication interface 1210.

[0357] It should be noted that the specific connection medium between the communication interface 1210 , the processor 1220 , and the memory 1230 is not limited in the embodiment of the present application. Fig.12 In the figure, the memory 1230, the processor 1220 and the communication interface 1210 are connected via the communication bus 1240. The connection between other components is only for schematic illustration and is not limited thereto. The communication bus 1240 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.12 Only one thick line is used in the figure, but it does not mean that there is only one communication bus or one type of communication bus.

[0358] In the embodiment of the present application, the processor 1220 may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The general-purpose processor may be a microprocessor or any conventional processor, etc. The method disclosed in the embodiment of the present application may be executed by hardware in the processor, or by a combination of hardware and software in the processor.

[0359] In the embodiment of the present application, the memory 1230 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), etc., or a volatile memory (volatile memory), such as a random-access memory (RAM). The memory may also be any other medium for carrying or storing program codes in the form of instructions or data structures and accessible by a computer; or, a circuit or any other device capable of realizing a storage function, for storing program instructions and / or data.

[0360] Based on the same idea, see Fig.13, the embodiment of the present application also provides another communication device 1300, including: an input-output interface 1310 and a logic circuit 1320; the input-output interface 1310 is used to receive code instructions and transmit them to the logic circuit 1320; the logic circuit 1320 is used to run code instructions to execute the method executed by the terminal device (such as the first terminal device, or the sixth terminal device), the network device, or the core network device in any of the above embodiments.

[0361] The following describes in detail the operations performed by the communication apparatus when applied to a terminal device (eg, the first terminal device or the sixth terminal device) or a network device.

[0362] In an optional implementation manner, the communication device 1300 can be applied to a first terminal device to execute the method executed by the first terminal device, for example, Figures 6 to 10 The method executed by the first terminal device in any of the illustrated embodiments. For example, the communication device 1300 sends a first message to the network device, or sends at least one first identifier to the network device.

[0363] Since the communication device 1300 provided in this embodiment can be applied to the first terminal device to complete the method executed by the first terminal device, the technical effects that can be obtained can refer to the above method embodiment and will not be repeated here.

[0364] In another optional implementation, the communication device 1300 can be applied to a network device to execute the method executed by the above network device, for example, Figures 6 to 10 The method executed by the network device in any of the illustrated embodiments. For example, the communication device 1300 receives a first message from a first terminal device, or receives at least one first identifier from a first terminal device.

[0365] Since the communication device 1300 provided in this embodiment can be applied to a network device to complete the method executed by the above network device, the technical effects that can be obtained can refer to the above method embodiment and will not be repeated here.

[0366] In another optional implementation manner, the communication device 1300 may be applied to a sixth terminal device to execute the method executed by the sixth terminal device, for example, Figures 6 to 10 The method executed by the sixth terminal device in any of the illustrated embodiments. For example, the communication device 1300 sends the fifth identifier and / or the sixth identifier to the network device.

[0367] Since the communication device 1300 provided in this embodiment can be applied to the sixth terminal device to complete the method performed by the sixth terminal device, the technical effects that can be obtained can refer to the above method embodiments and will not be repeated here.

[0368] In another optional implementation, the communication device 1300 can be applied to a core network device to execute the method executed by the core network device, such as the method executed by the core network device in each of the aforementioned embodiments. For example, the communication device 1300 receives the second indication information of the first terminal device, and sends the third indication information to the network device. For another example, the communication device 1300 receives the twelfth message of the first terminal device, and sends the seventh message to the network device.

[0369] Since the communication device 1300 provided in this embodiment can be applied to a core network device to complete the method executed by the core network device, the technical effects that can be obtained can refer to the above method embodiments and will not be described in detail here.

[0370] The embodiment of the present application also provides a communication system, which may include one or more of the following: a first terminal device, a network device, a sixth terminal device, or a core network device. The first terminal device, the network device, the sixth terminal device, or the core network device can all refer to the description in the above-mentioned method embodiments, and will not be repeated here.

[0371] A computer-readable storage medium is also provided in an embodiment of the present application, including program instructions, which, when executed on a computer, enables the computer to execute the method or steps of any communication device (for example, a first terminal device, a network device, a sixth terminal device, or a core network device) in the above-mentioned embodiments.

[0372] A computer program product is also provided in an embodiment of the present application, including program instructions, which, when executed on a computer, enable the computer to execute the method or steps of any communication device (for example, a first terminal device, a network device, a sixth terminal device, or a core network device) in the above-mentioned embodiments.

[0373] The embodiment of the present application provides a chip system, which includes a processor for implementing the functions of the terminal device or network device in the aforementioned method (for example, executing the corresponding method or step). The chip system can be composed of a chip, or can include a chip and other discrete devices.

[0374] Optionally, the chip system also includes a memory, which is used to store program instructions so that the above-mentioned processor can read and execute them to implement the corresponding method.

[0375] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0376] 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.

[0377] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0378] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the 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. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0379] The units described 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 achieve the purpose of the solution of this embodiment.

[0380] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0381] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the part of the technical solution of the present application that contributes essentially or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0382] The above is only a specific implementation of the present application, but the protection scope of the embodiments of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the embodiments of the present application, which should be included in the protection scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application should be based on the protection scope of the claims.

Claims

1. A communication method, applied to a first terminal device, characterized in that: The method comprises: Sending a first message to a network device, the first message including at least one first identifier, the first identifier being an identifier of a second terminal device used to provide a relay service for an emergency service, the first message also including an indication field of the first identifier, the indication field of the first identifier being used to indicate that the second terminal device supports the emergency service; receiving a first identifier of the at least one first identifier from the network device; A first connection is established between a target terminal device corresponding to the first identifier, wherein the first connection is used to transmit data of the emergency service.

2. The method according to claim 1, characterized in that The value of the indication field of the first identifier includes a first value and a second value, and the value of the indication field of the first identifier is the first value, wherein the first value is used to indicate that the second terminal device supports the emergency service, and the second value is used to indicate that the second terminal device supports non-emergency service.

3. The method according to claim 1 or 2, characterized in that: The first message also includes at least one second identifier, where the second identifier is an identifier of the third terminal device used to provide a relay service for non-emergency services.

4. The method according to claim 3, characterized in that The first message does not include an indication field of the second identifier, and the first message is used to indicate that the third terminal device supports the non-emergency service; or, The first message also includes an indication field of the second identifier, the value of the indication field of the second identifier includes a first value and a second value, and the value of the indication field of the second identifier is the second value, wherein the first value is used to indicate that the third terminal device supports the emergency service, and the second value is used to indicate that the third terminal device supports the non-emergency service.

5. The method according to any one of claims 1 to 4, characterized in that The method further comprises: Receive first indication information from the network device, where the first indication information instructs the first terminal device to measure the second terminal device.

6. The method according to any one of claims 1 to 5, characterized in that The method further comprises: Sending second indication information to the core network device, where the second indication information indicates that a fourth terminal device needs to be switched, and the fourth terminal device provides a relay service for the first terminal device; A second message is received from the network device, where the second message is used to request the first terminal device to send the first message.

7. The method according to any one of claims 1 to 5, characterized in that The method further comprises: A third message is received from the network device, wherein the third message includes a trigger condition for sending the first message, and the trigger condition includes data of the emergency service to be transmitted by the first terminal device.

8. A communication method, applied to a first terminal device, characterized in that: The method comprises: Sending at least one first identifier to the network device, where the first identifier is an identifier of the second terminal device used to provide a relay service for the emergency service; receiving a first identifier of the at least one first identifier from the network device; A first connection is established between a target terminal device corresponding to the first identifier, wherein the first connection is used to transmit data of the emergency service.

9. The method according to claim 8, characterized in that The method further comprises: A sixth message is received from the network device, where the sixth message is used to request the first terminal device to send the at least one first identifier.

10. The method according to claim 9, characterized in that The sixth message is sent by the network device in response to the seventh message of the core network device, the seventh message is used to request to establish a first session, and the first session is used for the emergency service.

11. The method according to claim 8, characterized in that The method further comprises: An eighth message is received from the network device, wherein the eighth message includes a trigger condition for sending the at least one first identifier, and the trigger condition includes data of the emergency service to be transmitted by the first terminal device.

12. The method according to any one of claims 1 to 11, characterized in that The method further comprises: Send at least one identifier of the first terminal device to the network device, wherein the at least one identifier includes a third identifier, or includes a third identifier and a fourth identifier, wherein the third identifier is an identifier of the first terminal device used for the emergency service, and the fourth identifier is an identifier of the first terminal device used for the non-emergency service.

13. The method according to any one of claims 1 to 12, characterized in that There is also a second connection between the target terminal device and the first terminal device, and the second connection is used to transmit data of non-emergency services.

14. The method according to claim 13, characterized in that The establishing a first connection between a target terminal device corresponding to the first identifier includes: releasing the second connection, and establishing the first connection according to the first identifier; or, The configuration information of the second connection is updated according to the first identifier to obtain the first connection, and the transmission of the data of the non-emergency service is stopped.

15. The method according to any one of claims 1 to 14, characterized in that The establishing a first connection between a target terminal device corresponding to the first identifier includes: A ninth message is sent to the target terminal device, wherein the ninth message is used to request establishment of the first connection, wherein the ninth message includes a relay service code for the emergency service, and the source identifier used to send the ninth message is a third identifier, and the third identifier is an identifier of the first terminal device used for the emergency service.

16. The method according to claim 15, characterized in that The method further comprises: A tenth message is sent to the target terminal device, and a source identifier used to send the tenth message is the third identifier.

17. A communication method, applied to a network device, characterized in that: The method comprises: Receive a first message from a first terminal device, the first message including at least one first identifier, the first identifier being an identifier of the second terminal device for providing a relay service for an emergency service, the first message also including an indication field of the first identifier, the indication field of the first identifier being used to indicate that the second terminal device supports the emergency service; A first identifier among the at least one first identifier is sent to the first terminal device, and a third identifier is sent to a target terminal device corresponding to the one first identifier, so that the first terminal device establishes a first connection with the target terminal device, wherein the first connection is used to transmit data of the emergency service, and the third identifier is an identifier of the first terminal device used for the emergency service.

18. The method according to claim 17, characterized in that The value of the indication field of the first identifier includes a first value and a second value, and the value of the indication field of the first identifier is the first value, wherein the first value is used to indicate that the second terminal device supports the emergency service, and the second value is used to indicate that the second terminal device supports non-emergency service.

19. The method according to claim 17 or 18, characterized in that The first message also includes at least one second identifier, where the second identifier is an identifier of the third terminal device used to provide a relay service for non-emergency services.

20. The method according to claim 19, characterized in that The first message does not include an indication field of the second identifier, and the first message is used to indicate that the third terminal device supports the non-emergency service; or, The first message also includes an indication field of the second identifier, the value of the indication field of the second identifier includes a first value and a second value, and the value of the indication field of the second identifier is the second value, wherein the first value is used to indicate that the third terminal device supports the emergency service, and the second value is used to indicate that the third terminal device supports the non-emergency service.

21. The method according to any one of claims 17 to 20, characterized in that The method further comprises: First indication information is sent to the first terminal device, where the first indication information instructs the first terminal device to measure the second terminal device.

22. The method according to any one of claims 17 to 21, characterized in that The method further comprises: receiving third indication information from a core network device, wherein the third indication information indicates configuring a fifth terminal device for the first terminal device, the fifth terminal device supporting the emergency service and having the ability to provide a relay service for the first terminal device; A second message is sent to the first terminal device according to the third indication information, where the second message is used to request the first terminal device to send the first message.

23. The method according to any one of claims 17 to 21, characterized in that The method further comprises: A third message is sent to the first terminal device, where the third message includes a triggering condition for sending the first message, and the triggering condition includes data of the emergency service to be transmitted by the first terminal device.

24. A communication method, applied to a network device, characterized in that: The method comprises: Receiving at least one first identifier from a first terminal device, where the first identifier is an identifier of a second terminal device used to provide a relay service for an emergency service; A first identifier among the at least one first identifier is sent to the first terminal device, and a third identifier is sent to a target terminal device corresponding to the one first identifier, so that the first terminal device establishes a first connection with the target terminal device, wherein the first connection is used to transmit data of the emergency service, and the third identifier is an identifier of the first terminal device used for the emergency service.

25. The method according to claim 24, characterized in that The method further comprises: A sixth message is sent to the first terminal device, where the sixth message is used to request the first terminal device to send the at least one first identifier.

26. The method according to claim 25, characterized in that The method further comprises: receiving a seventh message from a core network device, where the seventh message is used to request to establish a first session, where the first session is used for the emergency service; The sending the sixth message to the first terminal device includes: According to the seventh message, the sixth message is sent to the first terminal device.

27. The method according to claim 24, characterized in that The method further comprises: An eighth message is sent to the first terminal device, where the eighth message includes a triggering condition for sending the at least one first identifier, and the triggering condition includes data of the emergency service to be transmitted by the first terminal device.

28. The method according to any one of claims 17 to 27, characterized in that The method further comprises: Receive at least one identifier from the first terminal device, where the at least one identifier of the first terminal device includes the third identifier, or includes the third identifier and a fourth identifier, and the fourth identifier is an identifier of the first terminal device used for non-emergency services.

29. The method according to any one of claims 17 to 28, characterized in that The method further comprises: Receive at least one identifier from a sixth terminal device, wherein the at least one identifier of the sixth terminal device includes a fifth identifier and / or a sixth identifier, the fifth identifier is an identifier of the sixth terminal device used to provide relay service for the emergency service, and the sixth identifier is an identifier of the sixth terminal device used to provide relay service for non-emergency service.

30. The method according to any one of claims 17 to 29, characterized in that The method further comprises: An eleventh message is received from the target terminal device, the eleventh message is used to request to establish a third connection, the third connection is a connection between the target terminal device and the network device, the eleventh message includes a reason for establishing the third connection, and the reason for establishing includes emergency business.

31. The method according to claim 30, characterized in that The method further comprises: A tenth message is received from the target terminal device, where the tenth message is sent by the first terminal device in response to the first identifier of the network device.

32. A communication method, applied to a sixth terminal device, characterized in that: The method comprises: At least one identifier is sent to a network device, wherein the at least one identifier includes a fifth identifier and / or a sixth identifier, wherein the fifth identifier is an identifier of the sixth terminal device used to provide relay services for emergency services, and the sixth identifier is an identifier of the sixth terminal device used to provide relay services for non-emergency services.

33. The method according to claim 32, characterized in that The at least one identifier includes the fifth identifier, and the method further includes: receiving a third identifier from the network device, where the third identifier is an identifier of the first terminal device used for the emergency service; A first connection is established with the first terminal device according to the third identifier, where the first connection is used to transmit data of the emergency service.

34. The method according to claim 33, characterized in that The establishing a first connection with the first terminal device includes: A ninth message is received from the first terminal device, wherein the ninth message is used to request establishment of the first connection, wherein the ninth message includes a relay service code for the emergency service, and a source identifier for sending the ninth message is the third identifier.

35. The method according to claim 34, characterized in that The method further comprises: A tenth message is received from the first terminal device, and a source identifier used to send the tenth message is the third identifier.

36. The method according to claim 35, characterized in that The method further comprises: An eleventh message is sent to the network device, wherein the eleventh message is used to request establishment of a third connection, wherein the third connection is a connection between the sixth terminal device and the network device, and the eleventh message includes a reason for establishing the third connection, wherein the reason for establishing the third connection includes emergency services.

37. The method according to claim 35 or 36, characterized in that The method further comprises: It is determined according to the third identifier that the reason for establishing the third connection includes the emergency service, and the third connection is a connection between the sixth terminal device and the network device.

38. A communication device, characterized in that: A module or unit comprising a method for executing any one of claims 1 to 16, or a module or unit comprising a method for executing any one of claims 17 to 23, or a module or unit comprising a method for executing any one of claims 24 to 37.

39. A communication device, characterized in that: comprising at least one processor, wherein: The at least one processor is coupled to the memory, and is used to call computer instructions in the memory to execute the method as described in any one of claims 1 to 16, or to execute the method as described in any one of claims 17 to 23, or to execute the method as described in any one of claims 24 to 37.

40. A chip system, characterized in that: The chip system includes at least one processor, which is coupled to a memory and is used to execute one or more computer programs or instructions in the memory to implement the method as described in any one of claims 1 to 16, or to implement the method as described in any one of claims 17 to 23, or to implement the method as described in any one of claims 24 to 37.

41. A communication system, characterized in that: It includes one or more of the following: a first terminal device, a network device, and a sixth terminal device; wherein the first terminal device is used to execute the method as described in any one of claims 1 to 16, the network device is used to execute the method as described in any one of claims 17 to 23, and the sixth terminal device is used to execute the method as described in any one of claims 24 to 37.

42. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which, when called by the computer, execute the method as claimed in any one of claims 1 to 16, or the method as claimed in any one of claims 17 to 23, or the method as claimed in any one of claims 24 to 37.

43. A computer program product, characterized in that The method comprises instructions which, when executed on a computer, cause the method according to any one of claims 1 to 16 to be executed, or the method according to any one of claims 17 to 23 to be executed, or the method according to any one of claims 24 to 37 to be executed.

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