Communication method, apparatus, and communication system

Abstract

A communication method, an apparatus and a communication system, used to improve communication performance in a relay scenario. A first terminal device sends a first parameter to a network device, and receives from the network device a value of a first timer, the first parameter being related to a number of relay terminal devices between the first terminal device and a second terminal device, and the first terminal device communicating with the second terminal device by means of the relay terminal device, or the first parameter being related to a hop count between the first terminal device and the second terminal device. Thus, the first terminal device can report the first parameter to the network device, so that the network device, based on the first parameter, sends the value of the first timer to the first terminal device, thereby realizing timer configuration in a relay scenario, such that the timer is correctly started or stopped when the first terminal device subsequently satisfies a condition, improving communication performance in the relay scenario.

Description

Communication method, device and communication system

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on July 14, 2023, with application number 202310875943.8 and application name “A communication method, device and communication system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a communication method, device, and communication system. Background Art

[0004] In wireless communication systems, devices can communicate with each other directly, either over a network or without the aid of network equipment. When devices communicate directly, the link between them is called a sidelink (SL). This direct data transmission between devices, without going through the network, effectively reduces communication latency.

[0005] In some scenarios, terminal devices can communicate with each other through one or more relay terminal devices to improve sidelink coverage and capacity. In this scenario, sidelinks are used for communication between the source terminal device and the relay terminal device, between the relay terminal device and the target terminal device, and between relay terminal devices themselves.

[0006] Currently, in scenarios where two terminal devices communicate directly, when a terminal device sends a sidelink configuration message, it starts a timer for the target terminal device receiving the message. Upon receiving a configuration response message or a link failure message from the target terminal device, the timer is stopped. If the timer expires, the terminal device determines that the link has failed. However, there is currently no clear method for ensuring communication performance in relay scenarios. Therefore, improving communication performance in relay scenarios is an urgent issue.

[0007] Summary of the Invention

[0008] The present application provides a communication method, device and communication system for improving communication performance in relay scenarios.

[0009] 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: sending a first parameter to a network device, and receiving a value of a first timer from the network device. The first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, and the first terminal device communicates with the second terminal device through the relay terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device.

[0010] Based on the above communication method, the first terminal device can report the first parameter to the network device so that the network device sends the value of the first timer to the first terminal device based on the first parameter, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met, thereby improving the communication performance of the relay scenario.

[0011] In one possible design, the value of the first timer is determined based on the first parameter. This allows the network device to accurately determine the value of the first timer based on the first parameter and then configure it to the first terminal device.

[0012] In one possible design, the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, including: the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one. In this way, the first parameter can be accurately determined based on the number of relay terminal devices between the first terminal device and the second terminal device, and thus the value of the first timer can be accurately determined.

[0013] In one possible design, the first parameter is related to the number of hops between the first terminal device and the second terminal device, including: the first parameter being the number of hops between the first terminal device and the second terminal device; or the first parameter being the number of hops between the first terminal device and the second terminal device minus one. In this way, the first parameter can be accurately determined based on the number of hops between the first terminal device and the second terminal device, thereby accurately determining the value of the first timer.

[0014] In one possible design, it is determined that a first condition is met, and the first timer is stopped; wherein the first condition may include: receiving first indication information from the first relay terminal device, the first indication information is used to instruct the first terminal device to retain the unicast connection with the first relay terminal device, or is used to instruct the first terminal device to release the unicast connection with the first relay terminal device, or is used to indicate that a radio link failure occurs between the first relay terminal device and a third terminal device, the third terminal device is the second terminal device or the third terminal device is a relay terminal device between the first relay terminal device and the second terminal device, the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device. In this way, the first terminal device can correctly stop the first timer when it is determined that the first condition is met.

[0015] In one possible design, if the first timer expires, one or more of the following operations may be performed: sending a message to the first relay terminal device to instruct the first relay terminal device to maintain a link activation with the fourth terminal device, where the first relay terminal device is one of the relay terminal devices, the first relay terminal device communicates directly with the first terminal device, and the fourth terminal device is the second terminal device or the fourth terminal device is a relay terminal device between the first relay terminal device and the second terminal device; or sending second indication information to the first relay terminal device, where the second indication information is used to indicate the expiration of the first timer. In this way, after the first timer expires, the first terminal device can perform the corresponding operation.

[0016] In one possible design, a first parameter is determined so that the first parameter is subsequently reported to the network device.

[0017] In one possible design, the first parameter can be determined by the following method: determining the first parameter based on a fourth parameter, where the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices or the number of hops between the first terminal device and the second terminal device, or the fourth parameter includes the identifiers of one or more relay terminal devices; wherein the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device. In this way, the first parameter can be accurately determined based on the fourth parameter and then subsequently reported to the network device.

[0018] In one possible design, a fourth parameter is determined, and then the first terminal device determines the first parameter based on the fourth parameter.

[0019] In one possible design, the fourth parameter may be determined by the following method: receiving the fourth parameter from the first relay terminal device. In this way, the fourth parameter may be directly obtained from the first relay terminal device, thereby accurately determining the first parameter.

[0020] In one possible design, the fourth parameter may be determined by the following method: receiving a first value of the fourth parameter, so that the first parameter can be subsequently determined based on the first value of the fourth parameter.

[0021] In one possible design, the second value of the fourth parameter is sent, and the second value is used to determine the first value. This allows the relay terminal device and the second terminal device to accurately determine the first value of the fourth parameter based on the second value of the fourth parameter.

[0022] In one possible design, the fourth parameter can be determined by the following method: sending a fifth parameter and a sixth parameter, where the fifth parameter represents the maximum number of relay terminal devices and the sixth parameter represents the remaining number of relay terminal devices, or where the fifth parameter represents the maximum number of hops and the sixth parameter represents the remaining number of hops; and receiving a fourth parameter, where the fourth parameter is determined based on the fifth and sixth parameters. In this way, the fourth parameter can be accurately determined, and thus the first parameter can be accurately determined.

[0023] In one possible design, the first parameter is determined based on the fourth parameter. The method may be: when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter; or, when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus two. In this way, the first parameter can be accurately determined based on the fourth parameter.

[0024] In one possible design, the first parameter is sent to the second terminal device so that the first parameters of the second terminal device and the first terminal device are aligned, and then a suitable timer is started when the second terminal device subsequently transmits information to the first terminal device.

[0025] In a second aspect, the present application provides a communication method, which can be applied to a network device, or a component configured in the network device (such as a processor, chip, chip system, circuit, or other, etc.), or a software module. The method may include: receiving a first parameter from a first terminal device, and sending a first timer value to the first terminal device. The first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, and the first terminal device communicates with the second terminal device through the relay terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device.

[0026] Based on the above communication method, the first terminal device reports the first parameter to the network device so that the network device sends the value of the first timer to the first terminal device based on the first parameter, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met, thereby improving the communication performance of the relay scenario.

[0027] In one possible design, the value of the first timer is determined according to the first parameter. In this way, the network device can accurately determine the value of the first timer based on the first parameter, and then configure the value of the first timer to the first terminal device.

[0028] In one possible design, the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, including: the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one. In this way, the first parameter can be accurately determined based on the number of relay terminal devices between the first terminal device and the second terminal device, and thus the value of the first timer can be accurately determined.

[0029] The first parameter is related to the number of hops between the first terminal device and the second terminal device, including: the first parameter is the number of hops between the first terminal device and the second terminal device; or the first parameter is the number of hops between the first terminal device and the second terminal device minus one. In this way, the first parameter can be accurately determined based on the number of hops between the first terminal device and the second terminal device, and the value of the first timer can be accurately determined.

[0030] In a third aspect, the present application provides a communication method that can be applied to a first terminal device, or a component configured in the first terminal device (such as a processor, chip, chip system, circuit, or other, etc.), or a software module. The method may include: determining first information, and determining a value of a first timer based on the first information. The first information includes a first parameter; the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, and the first terminal device communicates with the second terminal device through the relay terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device.

[0031] Based on the above communication method, the first terminal device can accurately determine the value of the first timer based on the first parameter, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met, thereby improving the communication performance of the relay scenario.

[0032] In one possible design, the value of the first timer is positively correlated with the first parameter.

[0033] In one possible design, the first information further includes a second parameter and a third parameter, or the first information further includes the second parameter, the second parameter includes the value of the second timer, and the third parameter includes the offset value. In this way, the first terminal device can accurately determine the value of the first timer by combining the second parameter or the second parameter and the third parameter.

[0034] In one possible design, when the first information also includes a second parameter and a third parameter, the value of the first timer is positively correlated with the first parameter, the second parameter and the third parameter, or the value of the first timer is positively correlated with the first parameter and the second parameter and negatively correlated with the third parameter; when the first information also includes a second parameter, the value of the first timer is positively correlated with the first parameter and the second parameter.

[0035] In one possible design, determining the value of the first timer according to the first information may include: the value of the first timer = T0+N*T1; or, the value of the first timer = N*T0+T1; or, the value of the first timer = N*T0-T1; or, the value of the first timer = N*(T0+T1); or, the value of the first timer = N*(T0-T1); or, the value of the first timer = T0+(N-1)*T1; or, the value of the first timer = (N-1)*T0+T1; or, the value of the first timer = (N-1)*T0-T1; or, the value of the first timer = (N-1)*(T0+T1); or, the value of the first timer = (N-1)*(T0-T1); or, the value of the first timer = (N+1)*T0; or, the value of the first timer = N*T0. Wherein, T0 is the value of the second timer, which is a positive number; T1 is the offset value, which is a number greater than or equal to 0; and N is the first parameter, which is a positive integer. In this way, the value of the first timer can be accurately determined.

[0036] In one possible design, the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, including: the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one. In this way, the first parameter can be accurately determined based on the number of relay terminal devices between the first terminal device and the second terminal device, and thus the value of the first timer can be accurately determined.

[0037] In one possible design, the first parameter is related to the number of hops between the first terminal device and the second terminal device, including: the first parameter being the number of hops between the first terminal device and the second terminal device; or the first parameter being the number of hops between the first terminal device and the second terminal device minus one. In this way, the first parameter can be accurately determined based on the number of hops between the first terminal device and the second terminal device, thereby accurately determining the value of the first timer.

[0038] In one possible design, it is determined that a first condition is met, and the first timer is stopped; wherein the first condition may include: receiving first indication information from the first relay terminal device, the first indication information is used to instruct the first terminal device to retain the unicast connection with the first relay terminal device, or is used to instruct the first terminal device to release the unicast connection with the first relay terminal device, or is used to indicate that a radio link failure occurs between the first relay terminal device and a third terminal device, the third terminal device is the second terminal device or the third terminal device is a relay terminal device between the first relay terminal device and the second terminal device, the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device. In this way, the first terminal device can correctly stop the first timer when it is determined that the first condition is met.

[0039] In one possible design, if the first timer expires, one or more of the following operations may be performed: sending a message to the first relay terminal device to instruct the first relay terminal device to maintain a link activation with the fourth terminal device, where the first relay terminal device is one of the relay terminal devices, the first relay terminal device communicates directly with the first terminal device, and the fourth terminal device is the second terminal device or the fourth terminal device is a relay terminal device between the first relay terminal device and the second terminal device; or sending second indication information to the first relay terminal device, where the second indication information is used to indicate the expiration of the first timer. In this way, after the first timer expires, the first terminal device can perform the corresponding operation.

[0040] In one possible design, the first parameter included in the first information can be determined by the following method: the first parameter is determined based on a fourth parameter, where the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices or the number of hops between the first terminal device and the second terminal device, or the fourth parameter includes the identifiers of one or more relay terminal devices; wherein the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device. In this way, the first parameter can be accurately determined based on the fourth parameter and then subsequently reported to the network device.

[0041] In one possible design, a fourth parameter is determined, and then the first terminal device determines the first parameter based on the fourth parameter.

[0042] In one possible design, the fourth parameter may be determined by the following method: receiving the fourth parameter from the first relay terminal device. In this way, the fourth parameter may be directly obtained from the first relay terminal device, thereby accurately determining the first parameter.

[0043] In one possible design, the fourth parameter may be determined by the following method: receiving a first value of the fourth parameter, so that the first parameter can be subsequently determined based on the first value of the fourth parameter.

[0044] In one possible design, the second value of the fourth parameter is sent, and the second value is used to determine the first value. This allows the relay terminal device and the second terminal device to accurately determine the first value of the fourth parameter based on the second value of the fourth parameter.

[0045] In one possible design, the fourth parameter can be determined by the following method: sending a fifth parameter and a sixth parameter, where the fifth parameter represents the maximum number of relay terminal devices and the sixth parameter represents the remaining number of relay terminal devices, or where the fifth parameter represents the maximum number of hops and the sixth parameter represents the remaining number of hops; and receiving a fourth parameter, where the fourth parameter is determined based on the fifth and sixth parameters. In this way, the fourth parameter can be accurately determined, and thus the first parameter can be accurately determined.

[0046] In one possible design, the first parameter is determined based on the fourth parameter. The method may be: when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter; or, when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus two. In this way, the first parameter can be accurately determined based on the fourth parameter.

[0047] In one possible design, the first parameter is sent to the second terminal device so that the first parameters of the second terminal device and the first terminal device are aligned, and then a suitable timer is started when the second terminal device subsequently transmits information to the first terminal device.

[0048] In a fourth aspect, the present application provides a communication method that 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: determining second information, and determining a value of a first timer based on the second information. The second information includes a second parameter and a third parameter, or the second information includes the second parameter, the second parameter includes the value of the second timer, and the third parameter includes an offset value.

[0049] Based on the above communication method, in a scenario with only one relay terminal device, the first terminal device can accurately determine the value of the first timer, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met.

[0050] In one possible design, the value of the first timer is determined based on the second information. The method may be: when the second information includes the second parameter, the value of the first timer is a multiple of the value of the second timer; when the second information includes the second parameter and the third parameter, the value of the first timer is the sum of the value of the second timer and an offset value, or the difference between the multiple of the value of the second timer and the offset value. In this way, the first terminal device can accurately determine the value of the first timer based on the second information.

[0051] In one possible design, the multiple of the value of the second timer may be twice the value of the second timer.

[0052] In one possible design, it is determined that a first condition is met, and the first timer is stopped; wherein the first condition may include: receiving first indication information from the first relay terminal device, the first indication information being used to instruct the first terminal device to retain the unicast connection with the first relay terminal device, or being used to instruct the first terminal device to release the unicast connection with the first relay terminal device, or being used to indicate that a wireless link failure occurs between the first relay terminal device and the second terminal device, and the first terminal device communicates with the second terminal device through the first relay terminal device. In this way, the first terminal device can correctly stop the first timer when it is determined that the first condition is met.

[0053] In one possible design, if the first timer expires, one or more of the following operations may be performed: a message is sent to the first relay terminal device to instruct the first relay terminal device to maintain a link activation with the second terminal device, and the first terminal device communicates with the second terminal device through the first relay terminal device; or a second indication message is sent to the first relay terminal device, where the second indication message is used to indicate the expiration of the first timer. In this way, after the first timer expires, the first terminal device can perform the corresponding operation.

[0054] In a fifth aspect, the present application provides a communication method that 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: determining a value of a first timer, and sending the value of the first timer to a first terminal device.

[0055] Based on the above communication method, in a scenario where there is only one relay terminal device, the first terminal device can obtain the value of the first timer from the network device, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met.

[0056] In one possible design, the second parameter may be obtained, or the second parameter and the third parameter may be obtained, and then the value of the first timer may be determined based on the second parameter or the second parameter and the third parameter. In this way, the network device can accurately determine the value of the first timer.

[0057] In a sixth 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: determining a first parameter, the first parameter being related to the number of relay terminal devices between the first terminal device and the second terminal device, or the first parameter being related to the number of hops between the first terminal device and the second terminal device.

[0058] Based on the above communication method, the first terminal device can accurately determine the first parameter, and then subsequently determine the value of the first timer based on the first parameter, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met.

[0059] In one possible design, the first parameter can be determined based on the following method: the first parameter is determined based on a fourth parameter, where the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices or the number of hops between the first terminal device and the second terminal device, or the fourth parameter includes identifiers of one or more relay terminal devices; wherein the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device. In this way, the first parameter can be accurately determined based on the fourth parameter and then subsequently reported to the network device.

[0060] In one possible design, a fourth parameter is determined, and then the first terminal device determines the first parameter based on the fourth parameter.

[0061] In one possible design, the fourth parameter may be determined based on the following method: receiving the fourth parameter from the first relay terminal device. In this way, the fourth parameter may be directly obtained from the first relay terminal device, thereby accurately determining the first parameter.

[0062] In one possible design, the fourth parameter may be determined based on the following method: a first value of the fourth parameter is received, so that the first parameter may be subsequently determined based on the first value of the fourth parameter.

[0063] In one possible design, the second value of the fourth parameter is sent, and the second value is used to determine the first value. This allows the relay terminal device and the second terminal device to accurately determine the first value of the fourth parameter based on the second value of the fourth parameter.

[0064] In one possible design, the fourth parameter can be determined based on the following method: sending a fifth parameter and a sixth parameter, where the fifth parameter represents the maximum number of relay terminal devices and the sixth parameter represents the remaining number of relay terminal devices, or where the fifth parameter represents the maximum number of hops and the sixth parameter represents the remaining number of hops; and receiving a fourth parameter, where the fourth parameter is determined based on the fifth and sixth parameters. This allows accurate determination of the fourth parameter, and thus accurate determination of the first parameter.

[0065] In one possible design, the first parameter is determined based on the fourth parameter. The method may be: when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter; or, when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus two. In this way, the first parameter can be accurately determined based on the fourth parameter.

[0066] In one possible design, a first parameter is sent to the second terminal device so that the first parameters of the second terminal device and the first terminal device are aligned, and then an appropriate timer is started when the second terminal device subsequently transmits information to the first terminal device.

[0067] In the seventh aspect, the present application provides a communication method, which can be applied to a first terminal device, or a component configured in the first terminal device (such as a processor, chip, chip system, circuit or other, etc.), or a software module. The method may include: determining that a first condition is met and stopping a first timer; wherein the first condition may include: receiving a first indication information from a first relay terminal device, the first indication information is used to instruct the first terminal device to retain the unicast connection with the first relay terminal device, or to instruct the first terminal device to release the unicast connection with the first relay terminal device, or to indicate that a wireless link failure occurs between the first relay terminal device and a third terminal device, the third terminal device is the second terminal device or the third terminal device is a relay terminal device between the first relay terminal device and the second terminal device, the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device. In this way, the first terminal device can correctly stop the first timer when it is determined that the first condition is met.

[0068] In an eighth aspect, the present application provides a communication method, which can be applied to a first terminal device, or a component configured in the first terminal device (such as a processor, chip, chip system, circuit or other, etc.), or a software module. The method may include: if the first timer expires, one or more of the following operations may be performed: sending a message to the first relay terminal device to instruct the first relay terminal device to keep the link activated with the fourth terminal device, the first relay terminal device is one of the relay terminal devices, the first relay terminal device communicates directly with the first terminal device, the fourth terminal device is the second terminal device or the fourth terminal device is a relay terminal device between the first relay terminal device and the second terminal device; or, sending a second indication information to the first relay terminal device, the second indication information is used to indicate that the first timer has expired. In this way, after the first timer expires, the first terminal device can perform the corresponding operation.

[0069] In a ninth aspect, the present application further provides a communication device, which may be a first terminal device. The communication device has the function of implementing the first aspect or each possible design example of the first aspect, or the third aspect or each possible design example of the third aspect, or the fourth aspect or each possible design example of the fourth aspect, or the sixth aspect or each possible design example of the sixth aspect. The function can be implemented by hardware or by hardware executing the corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0070] In one possible design, the structure of the communication device includes a processing unit and, optionally, a transceiver unit. These units can perform the corresponding functions of the first aspect or each possible design example of the first aspect, or the third aspect or each possible design example of the third aspect, or the fourth aspect or each possible design example of the fourth aspect, or the sixth aspect or each possible design example of the sixth aspect. For details, please refer to the detailed description in the method example, which is not repeated here.

[0071] In one possible design, the structure of the communication device includes a processor and, optionally, a transceiver and / or memory. The transceiver is used to send and receive information and to communicate and interact with other devices in the system. The processor is configured to support the communication device in performing the corresponding functions of the first aspect or each possible design example of the first aspect, or the third aspect or each possible design example of the third aspect, or the fourth aspect or each possible design example of the fourth aspect, or the sixth aspect or each possible design example of the sixth aspect. The memory is coupled to the processor and stores program instructions and data necessary for the communication device.

[0072] In a tenth aspect, the present application further provides a communication device, which may be a network device. The communication device has the functions of implementing the second aspect or each possible design example of the second aspect, or the fifth aspect or each possible design example of the fifth aspect. The functions can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0073] In one possible design, the structure of the communication device includes a processing unit and, optionally, a transceiver unit. These units can perform the corresponding functions of the second aspect or each possible design example of the second aspect, or the fifth aspect or each possible design example of the fifth aspect. For details, please refer to the detailed description in the method example, which is not repeated here.

[0074] In one possible design, the communication device includes a processor and, optionally, a transceiver and / or memory. The transceiver is used to send and receive information and to communicate and interact with other devices in the system. The processor is configured to support the communication device in performing the corresponding functions described in the second aspect or each possible design example of the second aspect, or in the fifth aspect or each possible design example of the fifth aspect. The memory is coupled to the processor and stores program instructions and data necessary for the communication device.

[0075] In an eleventh aspect, the present application provides a communication system, which may include a first terminal device, a second terminal device, a network device, and a relay terminal device between the first terminal device and the second terminal device; or the communication system may include a first terminal device and a second terminal device, and a relay terminal device between the first terminal device and the second terminal device.

[0076] In the twelfth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores program instructions. When the program instructions are executed on a computer, the computer executes the method of the first aspect of the embodiment of the present application and any possible design thereof, or the method of the second aspect and any possible design thereof, or the method of the third aspect and any possible design thereof, or the method of the fourth aspect and any possible design thereof, or the method of the fifth aspect and any possible design thereof, or the method of the sixth aspect and any possible design thereof. Exemplarily, the computer-readable storage medium can be any available medium that can be accessed by a computer. Taking this as an example but not limited to: the computer-readable medium can include non-transitory computer-readable media, random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), CD-ROM or other optical disk storage, magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer.

[0077] In aspect 13, an embodiment of the present application provides a computer program product comprising computer program code or instructions. When the computer program code or instructions are run on a computer, the method of the first aspect or any possible design of the first aspect, or the method of the second aspect or any possible design of the second aspect, or the method of the third aspect or any possible design of the third aspect, or the method of the fourth aspect or any possible design of the fourth aspect, or the method of the fifth aspect or any possible design of the fifth aspect, or the method of the sixth aspect or any possible design of the sixth aspect is executed.

[0078] In the fourteenth aspect, the present application also provides a chip, including a processor, which is coupled to a memory and is used to read and execute program instructions stored in the memory, so that the chip implements the method of the above-mentioned first aspect or any possible design of the first aspect, or the above-mentioned second aspect or any possible design of the second aspect, or the above-mentioned third aspect or any possible design of the third aspect, or the above-mentioned fourth aspect or any possible design of the fourth aspect, or the above-mentioned fifth aspect or any possible design of the fifth aspect, or the above-mentioned sixth aspect or any possible design of the sixth aspect.

[0079] For each of the above-mentioned aspects 7 to 14 and the technical effects that may be achieved by each of the aspects 7 to 14, please refer to the above-mentioned description of the technical effects that can be achieved with respect to the first aspect or the various possible solutions in the first aspect, or the above-mentioned second aspect or the various possible solutions in the second aspect, or the third aspect and the various possible solutions in the third aspect, or the fourth aspect and the various possible solutions in the fourth aspect, or the fifth aspect and the various possible solutions in the fifth aspect, or the sixth aspect and the various possible solutions in the sixth aspect, and no further details will be given here. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] FIG1 is a schematic diagram of the architecture of a communication system provided by the present application;

[0081] FIG2a is a flow chart of a communication method provided by the present application;

[0082] Figure 2b is a schematic diagram of a scenario provided by this application;

[0083] Figure 2c is a schematic diagram of another scenario provided by this application;

[0084] Figure 2d is a schematic diagram of another scenario provided by this application;

[0085] Figure 2e is a schematic diagram of another scenario provided by this application;

[0086] Figure 2f is a schematic diagram of another scenario provided by this application;

[0087] Figure 2g is a schematic diagram of another scenario provided by this application;

[0088] FIG3 is a flow chart of another communication method provided by the present application;

[0089] FIG4 is a flow chart of another communication method provided by the present application;

[0090] FIG5 is a flow chart of another communication method provided by the present application;

[0091] FIG6 is a flow chart of another communication method provided by the present application;

[0092] FIG7 is a schematic structural diagram of a communication device provided by the present application;

[0093] FIG8 is a structural diagram of a communication device provided in this application. DETAILED DESCRIPTION

[0094] The present application will be described in further detail below with reference to the accompanying drawings.

[0095] The embodiments of the present application provide a communication method, device, and communication system for improving communication performance in relay scenarios. The method and device described in this application are based on the same technical concept. Since the method and device solve similar problems, the implementation of the device and method can refer to each other, and the repeated parts will not be repeated.

[0096] In the description of this application, words such as "first" and "second" are only used for the purpose of distinguishing the description and cannot be understood as indicating or implying relative importance or order.

[0097] In the description of this application, "at least one" means one or more, and "more" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c can be single or plural.

[0098] In the description of this application, "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. " / " means "or", for example, a / b means a or b.

[0099] In order to more clearly describe the technical solutions of the embodiments of the present application, the communication method and device provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0100] The embodiments of the present application can be applied to user equipment-to-user equipment (U2U) scenarios. FIG1 shows a schematic diagram of the architecture of a possible communication system to which the communication method provided by the present application is applicable. The architecture of the communication system may include network devices (such as network device 1 and network device 2 shown in FIG1 ), and terminal devices (such as source terminal devices, relay terminal devices, and target terminal devices shown in FIG1 ). Among them:

[0101] A network device is a device that provides access to a terminal device. A network device may include a radio access network (RAN) device, such as a base station. A network device may be a base station, an evolved Node B (eNB or e-NodeB) in a long-term evolution (LTE) system or long-term evolution-advanced (LTE-A), a transmission reception point (TRP), a next-generation NodeB (gNB) in a fifth-generation (5G) mobile communication system, 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 wireless local area network (WiFi) system. It may also be an access network device in an open access network (ORAN) system. Optionally, the network device may also be a module or unit that performs some of the functions of the base station. For example, the network device may 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 here performs the functions of the radio resource control protocol and the packet data convergence protocol (PDCP) of the base station, and may also perform the functions of the service data adaptation protocol (SDAP); the DU performs the functions of the radio link control layer and the medium access control (MAC) layer of the base station, and may also perform the functions of part or all of the physical layer. In different systems, CU (or CU-CP and CU-UP), DU, or RU may also have different names, but those skilled in the art will understand their meanings. For example, in the ORAN system, CU can also be called O-CU, DU can also be called open (open, O)-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CUP-UP, and RU can also be called O-RU.

[0102] Exemplarily, the network device may be a macro base station, a micro base station (also known as a small station) or an indoor station, or a relay node or a donor node, etc. The network device may also be a radio network controller (RNC), a node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (for example, a home evolved NodeB, or a home Node B, HNB), a base band unit (BBU) or a remote radio unit (RRU), or a wireless fidelity (Wifi) access point (AP), or a baseband pool (BBU pool) and RRU in a cloud radio access network (CRAN), etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device.

[0103] In this application, the network device may also be a functional module, a chip or a chip system. Optionally, the functional module, the chip or the chip system may be provided in the network device.

[0104] A terminal device, also known as user equipment (UE), mobile station (MS), or mobile terminal (MT), is a device that provides voice and / or data connectivity to users. For example, a terminal device may include a handheld device or vehicle-mounted device with wireless connectivity. Currently, terminal devices may include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, XR devices, MR devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, or wireless terminals in smart homes.

[0105] The terminal device may also be a device-to-device communication (D2D) terminal device, a vehicle-to-everything (V2X) communication terminal device, an intelligent vehicle, a vehicle-to-machine system (or a telematics box, TBOX), a machine-to-machine / machine-type communication (M2M / MTC) terminal device, or an Internet of Things (IoT) terminal device. For example, the terminal device may be a vehicle, ship, or aircraft, or a terminal-type roadside unit, or a communication module or chip built into a vehicle or roadside unit. For example, the terminal device may be a vehicle-mounted module. The terminal device may also be a roadside unit (RSU).

[0106] In this application, the terminal device may also be a functional module, a chip or a chip system. Optionally, the functional module, the chip or the chip system may be provided in the terminal device.

[0107] In this application, a relay terminal device is a terminal device that supports providing relay services, and a source terminal device and a target terminal device support communicating with each other through the relay service. The relay terminal device can assist the source terminal device and the target terminal device in communicating, thereby expanding the communication range and forwarding data between the source terminal device and the target terminal device. Sidelink (SL) communication can be performed between terminal devices. For example, SL unicast communication occurs between the source terminal device and the relay terminal device, and between the relay terminal device and the target terminal device.

[0108] In the present application, the source terminal device, the relay terminal device and the target terminal device may be in a radio resource control (RRC) connected state, an RRC idle state, an RRC inactive state, or an out of coverage (OOC) state.

[0109] It should be understood that the number of devices in the communication system shown in FIG1 is only an example and is not intended to limit the present application. For example, more relay terminal devices may be included.

[0110] At present, in the scenario where two terminal devices communicate directly, when the source terminal device sends a sidelink reconfiguration message, it will start a timer for the target terminal device that receives the message, such as timer T400, and stop the timer when it receives the configuration response message or link failure message returned by the target terminal device. If the timer expires, the source terminal device determines that the link has failed. However, the above-mentioned timer is currently only applicable to the scenario where two terminal devices communicate directly, that is, the scenario where there is no relay terminal device. In the scenario where there are one or more relay terminal devices between the terminal devices, if the judgment method of the above-mentioned timer is still used, the source terminal device will prematurely judge that the timer has expired, resulting in communication failure. Based on this, an embodiment of the present application provides a communication method that can improve the communication performance of the relay scenario. For example, the communication performance of the relay scenario can be improved by flexibly configuring the timer of the source terminal device in the scenario where there is a relay terminal device.

[0111] It should be noted that in the following description of this application, the operations performed by a certain device may also be performed by a processor, a chip, a chip system, or a functional module of the certain device. This application only uses the execution of a certain device as an example, but does not limit this application.

[0112] Based on the above description, a communication method provided in an embodiment of the present application is applicable to the communication system shown in Figure 1. Referring to Figure 2a, the specific process of the method may include:

[0113] Step 201: The first terminal device determines first information, where the first information includes a first parameter; the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, and the first terminal device communicates with the second terminal device through the relay terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device.

[0114] It should be understood that the number can also be described as quantity, etc. The number of relay terminal devices between the first terminal device and the second terminal device can be understood as the number of relay terminal devices present on the link between the first terminal device and the second terminal device, and can also be understood as the number of relay terminal devices through which the first terminal device and the second terminal device communicate.

[0115] The number of hops between the first terminal device and the second terminal device can be understood as the number of hops in the transmission process from the first terminal device to the second terminal device through the relay terminal device. For example, when there is a relay terminal device between the first terminal device and the second terminal device, the number of hops between the first terminal device and the second terminal device is 2, from the first terminal device to the relay terminal device is the first hop, and from the relay terminal device to the second terminal device is the second hop.

[0116] Here, step 201 may be an optional step.

[0117] Optionally, the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, and may include: the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or, the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one.

[0118] Among them, when the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one, it can also be understood that the first parameter is numerically equal to the number of hops between the first terminal device and the second terminal device.

[0119] Optionally, the first parameter is related to the number of hops between the first terminal device and the second terminal device, and may include: the first parameter is the number of hops between the first terminal device and the second terminal device; or the first parameter is the number of hops between the first terminal device and the second terminal device minus one.

[0120] Among them, when the first parameter is the number of hops of the relay terminal device between the first terminal device and the second terminal device minus one, it can also be understood that the first parameter is numerically equal to the number of relay terminal devices between the first terminal device and the second terminal device.

[0121] Step 202: The first terminal device determines the value of the first timer according to the first information.

[0122] Based on the above method, in a scenario where a relay terminal device exists, the first terminal device can accurately configure the first timer.

[0123] Exemplarily, the first timer is used to serve end-to-end transmission. For example, the first timer can be used to determine whether end-to-end message transmission fails.

[0124] In some embodiments, the first information may further include a second parameter and a third parameter, or the first information may further include a second parameter, the second parameter may include a value of the second timer, and the third parameter may include an offset value.

[0125] It should be understood that when the first information includes the second parameter and the third parameter, it can be understood that the first terminal device determines the value of the first timer based on the first parameter, the second parameter, and the third parameter. Optionally, the third parameter can be predefined or preconfigured. When the first information includes the third parameter, it can be understood that the first terminal device obtains the predefined or preconfigured third parameter. Of course, in this scenario, it can also be understood that the first information can include the second parameter, and the first terminal device determines the value of the first timer based on the first and second parameters in the first information, combined with the predefined or preconfigured third parameter.

[0126] The value of the first timer can be understood as the maximum time value of the first timer. The value of the second timer can be understood as the maximum time value of the second timer. The maximum time value can be understood as a period of time or a duration, etc. The maximum time value can represent the maximum time of the timer. That is, when the time value of the timer reaches the maximum time value, it can be understood that the timer expires. The time value can be in units such as microseconds (us), milliseconds (ms), or seconds (s).

[0127] In a possible case, the first timer and the second timer are the same, for example, the first timer and the second timer may be timer T400. In this case, the value of the first timer is different from the value of the second timer.

[0128] In another possible scenario, the first timer and the second timer may be different. For example, the second timer may be timer T400, and the first timer may be another newly defined timer, which is not limited in this application.

[0129] It should be understood that the multiple parameters included in the first information can be obtained separately through multiple signaling or multiple methods, or some of the multiple parameters can be obtained through one same signaling or one same method, and another part of the parameters can be obtained through another same signaling or another same method, or multiple parameters can also have other acquisition methods, which is not limited in this application.

[0130] In some embodiments, the network device is not aware of the topology of the U2U relay communication. When the first terminal device is in a different state, the first terminal device may determine the second parameter in the first information, or determine the second parameter and the third parameter in the first information in the following manner:

[0131] When the first terminal device is in the OOC state, the first terminal device may obtain the second parameter, or obtain the second parameter and the third parameter from a pre-configuration.

[0132] When the first terminal device is in an idle (IDLE) state or an inactive (INACTIVE) state, the first terminal device may obtain the second parameter, or obtain the second parameter and the third parameter, from a system information block (SIB).

[0133] When the first terminal device is in a connected state, the first terminal device may obtain the second parameter, or the second parameter and the third parameter, from a dedicated signaling, wherein the dedicated signaling may be an RRC reconfiguration message or other RRC message, which is not limited in this application.

[0134] In some further embodiments, the network device can perceive the topology of the U2U relay communication. When the first terminal device is in the OOC state, IDLE state or INACTIVE state, the method of determining the second parameter in the first information, or determining the second parameter and the third parameter in the first information, is the same as the method in the case where the above-mentioned network device does not perceive the topology of the U2U relay communication. They can refer to each other and will not be repeated here.

[0135] In an optional implementation, the value of the first timer is positively correlated with the first parameter.

[0136] Furthermore, when the first information also includes a second parameter and a third parameter, the value of the first timer is positively correlated with the first parameter, the second parameter, and the third parameter, or the value of the first timer is positively correlated with the first parameter and the second parameter and negatively correlated with the third parameter. When the first information also includes a second parameter, the value of the first timer is positively correlated with the first parameter and the second parameter.

[0137] Exemplarily, the first terminal device may determine the value of the first timer based on the first parameter, the value of the second timer and / or the offset value.

[0138] For example, when the first information includes the first parameter, the second parameter, and the third parameter, the first terminal device may determine the value of the first timer according to the first information, which may include the following method:

[0139] Method a1: the value of the first timer = T0 + N*T1.

[0140] Method a2: the value of the first timer = N*T0+T1.

[0141] Method a3: the value of the first timer = N*T0-T1.

[0142] Method a4: the value of the first timer = N*(T0+T1).

[0143] Method a5: the value of the first timer = N*(T0-T1).

[0144] Method a6: The value of the first timer = T0 + (N-1) * T1.

[0145] Method a7: The value of the first timer = (N-1)*T0+T1.

[0146] Method a8: The value of the first timer = (N-1)*T0-T1.

[0147] Method a9: The value of the first timer = (N-1)*(T0+T1).

[0148] Method a10: The value of the first timer = (N-1)*(T0-T1).

[0149] Wherein, T0 is the value of the second timer, and T0 is a positive number; T1 is the offset value, and T1 is a number greater than or equal to 0; N is the first parameter, and the first parameter is a positive integer.

[0150] In the above methods a1-a5, the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device, or the first parameter is the number of hops between the first terminal device and the second terminal device minus one. In the above methods a6-a10, the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one, or the first parameter is the number of hops between the first terminal device and the second terminal device.

[0151] In the case where the network device is not aware of the topology of the U2U relay communication, when the first terminal device is in any of the states of OOC, IDLE, INACTIVE, and connected, the first terminal device can determine the value of the first timer through the above methods a1-a10. In the case where the network device is aware of the topology of the U2U relay communication, when the first terminal device is in any of the states of OOC, IDLE, and INACTIVE, the first terminal device can determine the value of the first timer through the above methods a1-a10.

[0152] For another example, when the first information includes the first parameter and the second parameter, the first terminal device may determine the value of the first timer according to the first information, which may include the following method:

[0153] Method b1: the value of the first timer = (N+1)*T0.

[0154] For example, the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device, or the first parameter is the number of hops between the first terminal device and the second terminal device minus one.

[0155] Method b2: the value of the first timer = N*T0.

[0156] For example, the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one, or the first parameter is the number of hops between the first terminal device and the second terminal device.

[0157] In the case where the network device is not aware of the topology of the U2U relay communication, when the first terminal device is in any of the states of OOC, IDLE, INACTIVE, and connected, the first terminal device can determine the value of the first timer through the above methods b1 and b2. In the case where the network device is aware of the topology of the U2U relay communication, when the first terminal device is in any of the states of OOC, IDLE, and INACTIVE, the first terminal device can determine the value of the first timer through the above methods b1 and b2.

[0158] After the first terminal device determines the value of the first timer, the first terminal device may start the first timer after sending a sidelink reconfiguration message (RRCReconfigurationSidelink) to the second terminal device.

[0159] In an optional embodiment, the first terminal device determines that the first condition is met and stops the first timer; illustratively, the first condition may include one or more of the following: the first terminal device receives a sidelink reconfiguration completion (RRCReconfigurationCompleteSidelink) message from the second terminal device; or the first terminal device receives a first indication message from the first relay terminal device, the first indication message is used to instruct the first terminal device to retain the unicast connection with the first relay terminal device, or to instruct the first terminal device to release the unicast connection with the first relay terminal device, or to indicate that a radio link failure occurs between the first relay terminal device and the third terminal device, the third terminal device is the second terminal device or the third terminal device is a relay terminal device between the first relay terminal device and the second terminal device, the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device. Based on the above method, the first terminal device can identify the completion of link communication or link failure in advance without waiting for the first timer to expire, so as to perform link reconstruction or relay terminal device reselection.

[0160] In another optional embodiment, if the first timer expires, the first terminal device may perform one or more of the following operations: the first terminal device reselects the relay terminal device; or, the first terminal device retransmits the sidelink reconfiguration message; or, the first terminal device sends a unicast connection release message to the first relay terminal device; or, the first terminal device sends a message to the first relay terminal device for indicating that the link between the first relay terminal device and the fourth terminal device is kept activated, where the fourth terminal device is the second terminal device or the fourth terminal device is a relay terminal device between the first relay terminal device and the second terminal device. For example, the fourth terminal device may be as shown in Figures 2b and 2c. It should be understood that Figures 2b and 2c only show two possible situations. When there are multiple relay terminal devices between the first relay terminal device and the second terminal device, the fourth terminal device can be any one of the multiple relay terminal devices, which is no longer shown in the figure here; or, the first terminal device sends a second indication message to the first relay terminal device, where the second indication message is used to indicate that the first timer has expired. Based on the above method, the communication resources of the first terminal device can be saved, or the first terminal device can identify which links can continue to be used, thereby shortening the end-to-end communication delay.

[0161] Optionally, after the first relay terminal device receives a message instructing the first relay terminal device to keep the link between the first relay terminal device and the fourth terminal device activated, the first relay terminal device may forward the message to the fourth terminal device.

[0162] Exemplarily, after the first relay terminal device receives the second indication information, the first relay terminal device may send a message to the fifth terminal device for instructing the first relay terminal device to maintain link activation with the fifth terminal device, where the fifth terminal device is the second terminal device or the fifth terminal device is a relay terminal device between the first relay terminal device and the second terminal device. Alternatively, the first relay terminal device may also forward the second indication information to the fifth terminal device. For example, the fifth terminal device may be as shown in Figures 2d and 2e. It should be understood that Figures 2d and 2e only show two possible situations. When there are multiple relay terminal devices between the first relay terminal device and the second terminal device, the fifth terminal device may be any one of the multiple relay terminal devices, which is no longer shown in the figure here.

[0163] In some embodiments, the first terminal device can determine the first parameter included in the first information by the following method: the first terminal device determines the first parameter based on a fourth parameter, the fourth parameter can be the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter can be the number of relay terminal devices between the first relay terminal device and the second terminal device, or the fourth parameter can be the number of relay terminal devices or the number of hops between the first terminal device and the second terminal device, or the fourth parameter can include the identification of one or more relay terminal devices.

[0164] Before determining the first parameter, the first terminal device may determine the fourth parameter. For example, the first terminal device may determine the fourth parameter using one or more of a variety of methods. For example, the first terminal device may determine the fourth parameter using one or more of the following methods c1 to c4, which are not limited in this application.

[0165] Method c1: The first terminal device receives a fourth parameter from the first relay terminal device.

[0166] For example, this method can be applied to the process of discovering terminal devices, such as the process in which a terminal device broadcasts a message so as to be discovered by other terminal devices, such as the Model A discovery process; or the process in which a terminal device discovers other terminal devices by broadcasting a message, such as the Model B discovery process.

[0167] In one possible manner, the first terminal device may receive the fourth parameter by receiving a first message from the first relay terminal device. For example, the first message may be an announcement message. In the following description, the first message is taken as an example of an announcement message. Optionally, the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter may be the number of relay terminal devices between the first relay terminal device and the second terminal device. For example, the fourth parameter is represented by M, where M is an integer greater than or equal to 0.

[0168] Before the first relay terminal device sends an announcement message to the first terminal device, the first relay terminal device may determine the list information in the announcement message, wherein the list information may include the correspondence between the remote UE and the fourth parameter M. The list information may include the correspondence in such a way that each entry in the list includes the remote UE identifier and the fourth parameter M; or it may include two lists, list #1 includes the remote UE identifier, list #2 includes the fourth parameter M, and the remote UE identifier in list #1 corresponds to the fourth parameter M in list #2 according to the order of arrangement in the list. For example, if list #1 includes {remote UE#1, remote UE#2}, and list #2 includes {M#1, M#2}, then remote UE#1 corresponds to M#1, and remote UE#2 corresponds to M#2. The remote UE identifier may be a user information identifier (user info ID).

[0169] The first relay terminal device may determine the list information in a manner that is a combination of one or more of the following manners:

[0170] Method 1: The first relay terminal device receives an announcement message from other relay terminal devices. The other relay terminal devices may be relay terminal devices around the first relay terminal device that can mutually discover or communicate with the first relay terminal device. For example, the other terminal devices may be the second relay terminal device, the third relay terminal device, and the fourth relay terminal device shown in Figure 2f. For example, the first relay terminal device receives an announcement message from the second relay terminal device. Optionally, the first relay terminal device can receive an announcement message from the second relay terminal device, which can be understood as the first relay terminal device and the second relay terminal device being able to communicate directly. The announcement message of the other relay terminal device may include a remote UE identifier and a corresponding parameter M1, where M1 is the number of hops between the other relay terminal device and the remote UE, or may be the number of relay terminal devices between the other relay terminal device and the remote UE. The first relay terminal device adds the remote UE identifier carried in the announcement message of other relay terminal devices to the list information, and the corresponding M=M1+1, where M1 is an integer greater than or equal to 0.

[0171] Optionally, the first relay terminal device determines whether M1 is greater than the maximum number of hops minus two or the maximum number of relays minus two. If not, the remote UE identifier is added to the list information, otherwise it is not added.

[0172] Method 2: The first relay terminal device receives a second message from other terminal devices (such as other relay terminal devices or remote UE). Exemplarily, the other terminal devices may be relay terminal devices around the first relay terminal device that can discover or communicate with the first relay terminal device. For example, the other terminal devices may be the second relay terminal device and the third relay terminal device shown in Figure 2g, etc.; or the other terminal devices may also be the second terminal device shown in Figure 2g. For example, the second message may be a solicitation message or a response message. The second message may carry a remote UE identifier and parameter M2, where M2 represents the number of relay terminals or the number of hops between the remote UE and the first relay terminal device, and M2 is an integer greater than or equal to 0. The first relay terminal device adds the remote UE identifier carried in the solicitation message or the response message to the list information, and the corresponding M may be:

[0173] M=M2, where M is the number of hops between the first relay terminal device and the second terminal device, and M2 is the number of hops between the remote UE and the first relay terminal device; or, M is the number of relay terminal devices between the first relay terminal device and the second terminal device, and M2 is the number of relay terminals between the remote UE and the first relay terminal device; or

[0174] M=M2+1, where M is the number of hops between the first relay terminal device and the second terminal device, and M2 is the number of relay terminals between the remote UE and the first relay terminal device; or

[0175] M=M2-1, where M is the number of relay terminal devices between the first relay terminal device and the second terminal device, and M2 is the number of hops between the remote UE and the first relay terminal device.

[0176] In the above manner, the first relay terminal device can obtain the identifiers of one or more remote UEs and their corresponding M, and then the first relay terminal device can carry the identifiers of the one or more remote UEs and their corresponding M in the first message and send it to the first terminal device. The one or more remote UEs include the second terminal device, so that the first terminal device can identify the M corresponding to the second terminal device, which is the fourth parameter.

[0177] Furthermore, the first terminal device determining the first parameter according to the fourth parameter may include:

[0178] When the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter; in this case, the first parameter is the number of hops between the first terminal device and the second terminal device minus one; or

[0179] When the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; in this case, the first parameter is the number of hops between the first terminal device and the second terminal device; or

[0180] When the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; in this case, the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or

[0181] When the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus two; at this time, the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one.

[0182] In one possible manner, the first terminal device may receive the fourth parameter by receiving the third message from the first relay terminal device. For example, the fourth parameter may include identifiers of one or more relay terminal devices.

[0183] Exemplarily, this approach can be applied to one or more of the Model B discovery process, the discovery integration into unicast connection establishment process, or the hop-by-hop unicast connection establishment process.

[0184] In different processes, the third message may be different messages.

[0185] For example, the third message may be a response message sent by the first relay terminal device to the first terminal device.

[0186] Exemplarily, after the first terminal device broadcasts a solicitation message, the first relay terminal device, after receiving the solicitation message broadcast by the first terminal device, broadcasts a solicitation message. After the second terminal device receives the solicitation message broadcast by the first relay terminal device, it sends a response message to the first relay terminal device. Afterwards, the first relay terminal device sends a response message to the first terminal device, wherein the response message sent by the first relay terminal device to the first terminal device includes an identifier of the first relay terminal device. The identifier of the first relay terminal device may be the user info ID of the first relay terminal device.

[0187] It should be understood that the above description uses the example of the first terminal device and the second terminal device communicating through the first relay terminal device. When the first terminal device and the second terminal device communicate through the first relay terminal device and other relay terminal devices, the response message received by the first relay terminal device from the other relay terminal devices includes the identifiers of the other relay terminals, and the response message sent by the first relay terminal device to the first terminal device includes the identifier of the first relay terminal device and the identifiers of the other relay terminal devices.

[0188] For another example, the third message may be a direct communication accept (DCA) message sent by the first relay terminal device to the first terminal device.

[0189] Exemplarily, the first terminal device broadcasts a direct communication request (DCR) message. After receiving the DCR message broadcast by the first terminal device, the first relay terminal device broadcasts the DCR message. After receiving the DCR message broadcast by the first relay terminal device, the second terminal device sends a DCA message to the first relay terminal device. Thereafter, the first relay terminal device sends a DCA message to the first terminal device, wherein the DCA message sent by the first relay terminal device to the first terminal device includes an identifier of the first relay terminal device. Similarly, the identifier of the first relay terminal device can be the user info ID of the first relay terminal device.

[0190] It should be understood that the above description uses the example of the first terminal device and the second terminal device communicating through the first relay terminal device. When the first terminal device and the second terminal device communicate through the first relay terminal device and other relay terminal devices, the DCA message received by the first relay terminal device from the other relay terminal devices includes the identifiers of the other relay terminals, and then the DCA message sent by the first relay terminal device to the first terminal device includes the identifier of the first relay terminal device and the identifiers of the other relay terminal devices.

[0191] Furthermore, the first terminal device may determine the first parameter by the number of identifiers of the relay terminal devices included in the third message. For example:

[0192] First parameter=number of relay terminal device identifiers, where the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or

[0193] The first parameter=the number of identifiers of relay terminal devices+1. In this case, the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one.

[0194] Method c2: The first terminal device may receive a first value of the fourth parameter. In this case, the first value of the fourth parameter is the number of relay terminal devices or the number of hops between the first terminal device and the second terminal device.

[0195] Illustratively, the method may be applied to one or more of the Model B discovery process, the discovery integration into unicast connection establishment process, or the hop-by-hop unicast connection establishment process.

[0196] Optionally, the first terminal device may receive the first value of the fourth parameter by receiving a fourth message from the first relay terminal device.

[0197] In different processes, the fourth message may be a different message.

[0198] For example, the fourth message may be a response message sent by the first relay terminal device to the first terminal device.

[0199] Exemplarily, after the first terminal device broadcasts a solicitation message, the first relay terminal device broadcasts a solicitation message after receiving the solicitation message broadcast by the first terminal device. After the second terminal device receives the solicitation message broadcast by the first relay terminal device, it sends a response message to the first relay terminal device. The response message sent by the second terminal device to the first relay terminal device may carry the third value of the fourth parameter. For example, the fourth parameter may be denoted as X. X is used as an example below. The value of X is 0 or 1, that is, the third value of the fourth parameter is 0 or 1. For example, X may include the following three designs:

[0200] Design 1: X represents the number of relay terminal devices, and the value of X is 0. The value of X being 0 indicates that when the second terminal device sends a response message, it has not yet passed through the relay terminal device.

[0201] Design 2: X represents the number of hops, and X is 0. A value of 0 indicates that when the second terminal device sends a response message, the link between the second terminal device and the relay terminal device (e.g., the first relay terminal device) that directly receives the response message from the second terminal device does not count as a hop. The relay terminal device that directly receives the response message from the second terminal device can also be understood as the destination relay terminal device for the response message, and the same applies to the rest of the text.

[0202] Design three, X represents the number of hops, and the value of X is 1; the value of X being 1 can indicate that when the second terminal device sends a response message, the link between the second terminal device and the relay terminal device (such as the first relay terminal device) that directly receives the response message from the second terminal device itself is counted as one hop.

[0203] Afterwards, the first relay terminal device sends a response message to the first terminal device, wherein the value of X included in the response message sent by the first relay terminal device to the first terminal device is one greater than the value of X carried in the response message sent by the second terminal device to the first relay terminal device. The value of X carried in the response message sent by the first relay terminal device to the first terminal device is the first value of the fourth parameter.

[0204] It should be understood that the above process is explained using the example of the first terminal device and the second terminal device communicating through the first relay terminal device. When the first terminal device and the second terminal device communicate through the first relay terminal device and other relay terminal devices, the response message received by the first relay terminal device from the other relay terminal devices includes another value of X, and the response message sent by the first relay terminal device to the first terminal device includes another value of X plus one. After the response message is sent from the second terminal device, the corresponding value of X increases by one for each relay terminal device passed through. For example, when there are three relay terminal devices between the first terminal device and the second terminal device, the first value of the fourth parameter received by the first terminal device is the value obtained by adding 3 to the initial value of X (here, the third value).

[0205] For another example, the fourth message may be a DCA message sent by the first relay terminal device to the first terminal device.

[0206] For example, after the first terminal device broadcasts a DCR message, the first relay terminal device, after receiving the DCR message broadcast by the first terminal device, also broadcasts a DCR message. After receiving the DCR message broadcast by the first relay terminal device, the second terminal device sends a DCA message to the first relay terminal device. The DCA message sent by the second terminal device to the first relay terminal device can carry X, where X takes a value of 0 or 1. For example, the three designs described above may be included, which will not be further described here.

[0207] Afterwards, the first relay terminal device sends a DCA message to the first terminal device, wherein X included in the DCA message sent by the first relay terminal device to the first terminal device is the value of X carried in the DCA message sent by the second terminal device to the first relay terminal device, increased by one. The value of X carried in the DCA message sent by the first relay terminal device to the first terminal device is the first value of the fourth parameter.

[0208] It should be understood that the above process uses the example of a first terminal device and a second terminal device communicating via a first relay terminal device. When the first terminal device and the second terminal device communicate via the first relay terminal device and other relay terminal devices, the DCA message received by the first relay terminal device from the other relay terminal device includes another value of X, and the DCA message sent by the first relay terminal device to the first terminal device includes the other value of X incremented by one. After the DCA message is sent from the second terminal device, the corresponding value of X increments by one for each relay terminal device passed through. For example, when there are three relay terminal devices between the first terminal device and the second terminal device, the first value of the fourth parameter received by the first terminal device is the initial value of X plus 3.

[0209] Furthermore, the first terminal device may determine the first parameter by using the first value of the fourth parameter included in the fourth message. For example:

[0210] For the above design 1:

[0211] The first parameter=the first value of the fourth parameter, where the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or

[0212] The first parameter=the first value of the fourth parameter+1, where the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one.

[0213] For the above design 2:

[0214] The first parameter=the first value of the fourth parameter, where the first parameter is the number of hops between the first terminal device and the second terminal device minus one; or

[0215] The first parameter=the first value of the fourth parameter+1, where the first parameter is the number of hops between the first terminal device and the second terminal device.

[0216] For the above design three:

[0217] The first parameter=the first value of the fourth parameter-1, where the first parameter is the number of hops between the first terminal device and the second terminal device minus one; or

[0218] The first parameter=the first value of the fourth parameter, where the first parameter is the number of hops between the first terminal device and the second terminal device.

[0219] Method c3: The first terminal device may send a second value of the fourth parameter, the second value being used to determine the first value of the fourth parameter; and the first terminal device receives the first value of the fourth parameter. For example, the first value of the fourth parameter is the number of relay terminal devices or the number of hops between the first terminal device and the second terminal device.

[0220] Illustratively, the method may be applied to one or more of the Model B discovery process, the discovery integration into unicast connection establishment process, or the hop-by-hop unicast connection establishment process.

[0221] Exemplarily, the first terminal device may send the second value of the fourth parameter via a fifth message, and receive the first value of the fourth parameter by receiving a sixth message from the first relay terminal device.

[0222] In different processes, the fifth message may be a different message, and correspondingly the sixth message may be a different message.

[0223] For example, the fifth message may be a solicitation message broadcast by the first terminal device, and the sixth message may be a response message sent by the first relay terminal device to the first terminal device.

[0224] Exemplarily, the first terminal device broadcasts a solicitation message, and the request message broadcast by the first terminal device carries the second value of the fourth parameter. The fourth parameter can be recorded as W. The following takes W as an example. The value of W is 0 or 1, that is, the second value of the fourth parameter is 0 or 1. For example, W can include the following three designs:

[0225] Design 1, W represents the number of relay terminal devices, and the value of W is 0; the value of W being 0 can indicate that when the first terminal device broadcasts the request message, it has not yet passed through the relay terminal device.

[0226] Design 2: W represents the number of hops, and W is 0. A value of 0 indicates that when the first terminal device broadcasts a request message, the link between the first terminal device and the relay terminal device that directly receives the request message from the first terminal device (e.g., the first relay terminal device) does not count as a hop. The relay terminal device that directly receives the response message from the first terminal device can also be understood as the destination relay terminal device of the response message, and the same applies to the following.

[0227] Design 3, W represents the number of hops, and the value of W is 1; the value of W is 1, which means that when the first terminal device broadcasts a request message, the link between the first terminal device and the relay terminal device (such as the first relay terminal device) that directly receives the request message from the first terminal device is counted as one hop.

[0228] After the first relay terminal device receives the solicitation message broadcast by the first terminal device, it broadcasts the solicitation message. The value of W contained in the solicitation message broadcast by the first relay terminal device is increased by one relative to the value of W in the solicitation message broadcast by the first terminal device. After the second terminal device receives the solicitation message broadcast by the first relay terminal device, it sends a response message to the first relay terminal device. Among them, for the above-mentioned Design 1 and Design 3, the value of W contained in the response message sent by the second terminal device to the first relay terminal device remains unchanged relative to the value of W in the solicitation message broadcast by the first relay terminal device; for the above-mentioned Design 2, the value of W contained in the response message sent by the second terminal device to the first relay terminal device is increased by one relative to the value of W in the solicitation message broadcast by the first relay terminal device.

[0229] Afterwards, the first relay terminal device sends a response message to the first terminal device, wherein the value of W included in the response message sent by the first relay terminal device to the first terminal device is unchanged relative to the value of W carried in the response message sent by the second terminal device to the first relay terminal device. The value of W carried in the response message sent by the first relay terminal device to the first terminal device is the first value of the fourth parameter.

[0230] It should be understood that the above process is explained using the example of the first terminal device and the second terminal device communicating through the first relay terminal device. When the first terminal device and the second terminal device communicate through the first relay terminal device and other relay terminal devices, the second terminal device receives from the other relay terminal devices a broadcast request message containing another value of W, and then the second terminal device performs the above-mentioned unchanged or plus one operation based on the other value of W contained in the request message broadcast by the other relay terminal devices. After the request message is broadcast from the first terminal device, the corresponding value of W is increased by one for each relay terminal device passed through. For example, when there are three relay terminal devices between the first terminal device and the second terminal device, for Design 1 and Design 3, the first value of the fourth parameter received by the first terminal device is the value obtained by adding 2 to the second value of W; for Design 2, the first value of the fourth parameter received by the first terminal device is the value obtained by adding 3 to the second value of W.

[0231] For another example, the fifth message is a DCR message broadcast by the first terminal device, and the sixth message may be a DCA message sent by the first relay terminal device to the first terminal device.

[0232] Exemplarily, the first terminal device broadcasts a DCR message, and the DCR message broadcast by the first terminal device carries W, where W takes a value of 0 or 1, that is, the second value of the fourth parameter is 0 or 1. For example, W can include the three designs described above, which will not be repeated here.

[0233] After receiving the DCR message broadcast by the first terminal device, the first relay terminal device broadcasts the DCR message. The value of W contained in the DCR message broadcast by the first relay terminal device is increased by one relative to the value of W in the DCR message broadcast by the first terminal device. After receiving the DCR message broadcast by the first relay terminal device, the second terminal device sends a DCA message to the first relay terminal device. Specifically, for the above-mentioned Design 1 and Design 3, the value of W contained in the DCA message sent by the second terminal device to the first relay terminal device remains unchanged relative to the value of W in the DCR message broadcast by the first relay terminal device; for the above-mentioned Design 2, the value of W contained in the DCA message sent by the second terminal device to the first relay terminal device is increased by one relative to the value of W in the DCR message broadcast by the first relay terminal device.

[0234] Afterwards, the first relay terminal device sends a DCA message to the first terminal device, wherein the value of W included in the DCA message sent by the first relay terminal device to the first terminal device remains unchanged relative to the value of W carried in the DCA message sent by the second terminal device to the first relay terminal device. The value of W carried in the DCA message sent by the first relay terminal device to the first terminal device is the first value of the fourth parameter.

[0235] It should be understood that the above process is illustrated using the example of a first terminal device and a second terminal device communicating via a first relay terminal device. When the first terminal device and the second terminal device communicate via the first relay terminal device and other relay terminal devices, the second terminal device receives a broadcast DCR message from the other relay terminal devices containing another value of W. The second terminal device then performs the above-described unchanged or incremented operation based on the other value of W contained in the DCR message broadcast by the other relay terminal devices. After the DCR message is broadcast from the first terminal device, the corresponding value of W is incremented by one for each relay terminal device it passes through. For example, when there are three relay terminal devices between the first terminal device and the second terminal device, for Designs 1 and 3, the first value of the fourth parameter received by the first terminal device is the value obtained by adding 2 to the second value of W; for Design 2, the first value of the fourth parameter received by the first terminal device is the value obtained by adding 3 to the second value of W.

[0236] Furthermore, the first terminal device may determine the first parameter by using the first value of the fourth parameter included in the sixth message. For example:

[0237] The first parameter=the first value of the fourth parameter-1, the first value of the fourth parameter is the number of hops between the first terminal device and the second terminal device, and the first parameter is the number of hops between the first terminal device and the second terminal device minus one; or

[0238] The first parameter = the first value of the fourth parameter, in which case the fourth parameter is the number of relay terminal devices between the first terminal device and the second terminal device, and the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or, the first value of the fourth parameter is the number of hops between the first terminal device and the second terminal device, and the first parameter is the number of hops between the first terminal device and the second terminal device; or

[0239] The first parameter = the first value of the fourth parameter + 1. At this time, the fourth parameter is the number of relay terminal devices between the first terminal device and the second terminal device, and the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one.

[0240] Method c4: The first terminal device may send a fifth parameter and a sixth parameter, where the fifth parameter indicates the maximum number of relay terminal devices and the sixth parameter indicates the remaining number of relay terminal devices, or the fifth parameter indicates the maximum number of hops and the sixth parameter indicates the remaining number of hops. The first terminal device may receive a fourth parameter, which is determined based on the fifth and sixth parameters. In this case, the fourth parameter is the number of relay terminal devices between the first terminal device and the second terminal device, or the fourth parameter is the number of hops between the first terminal device and the second terminal device.

[0241] Illustratively, the method may be applied to one or more of the Model B discovery process, the discovery integration into unicast connection establishment process, or the hop-by-hop unicast connection establishment process.

[0242] Exemplarily, the first terminal device may send the fifth parameter and the sixth parameter via the seventh message, and the first terminal device may receive the fourth parameter by receiving the eighth message from the first relay terminal device.

[0243] In different processes, the seventh message may be a different message, and the eighth message may be a different message.

[0244] For example, the seventh message may be a solicitation message broadcast by the first terminal device, and the eighth message may be a response message sent by the first relay terminal device to the first terminal device.

[0245] Exemplarily, in the process of discovering the other end, the first terminal device broadcasts a solicitation message, and the solicitation message broadcast by the first terminal device carries a fifth parameter (denoted as MAX) and a sixth parameter (denoted as Y1), and the initial Y1=MAX or Y1=MAX-1. After the first relay terminal device receives the solicitation message broadcast by the first terminal device, it broadcasts the solicitation message. Among them, the request message broadcast by the first relay terminal device carries MAX and Y1, and the value of Y1 is one less than the value of Y1 carried in the request message broadcast by the first terminal device. After the second terminal device receives the request message broadcast by the first relay terminal device, it sends a response message to the first relay terminal device, and the response message carries parameter Y2, and the value of Y2 is Y2=MAX-Y1+1 or Y2=MAX-Y1, wherein the value of Y1 is the value of Y1 carried in the request message broadcast by the first relay terminal device. Afterwards, the first relay device sends a response message to the first terminal device, which carries Y2, whose value remains unchanged from the value of Y2 in the response message sent by the second terminal device to the first relay terminal device. Y2 carried in the response message sent by the first relay terminal device to the first terminal device is the fourth parameter.

[0246] For another example, the seventh message is a DCR message broadcast by the first terminal device, and the eighth message may be a DCA message sent by the first relay terminal device to the first terminal device.

[0247] Exemplarily, in the process of discovering integration into unicast connection establishment, or in the process of hop-by-hop unicast connection establishment, the first terminal device broadcasts a DCR message, and the DCR message broadcast by the first terminal device carries a fifth parameter (denoted as MAX) and a sixth parameter (denoted as Y1), and the initial Y1=MAX or Y1=MAX-1. After the first relay terminal device receives the DCR message broadcast by the first terminal device, it broadcasts the DCR message. Among them, the DCR message broadcast by the first relay terminal device carries MAX and Y1, and the value of Y1 is one less than the value of Y1 carried in the DCR message broadcast by the first terminal device. After the second terminal device receives the DCR message broadcast by the first relay terminal device, it sends a DCA message to the first relay terminal device, and the response message carries parameter Y2, and the value of Y2 is Y2=MAX-Y1+1 or Y2=MAX-Y1, wherein the value of Y1 is the value of Y1 carried in the request message broadcast by the first relay terminal device. Afterwards, the first relay device sends a DCA message to the first terminal device, which carries Y2. The value of Y2 is the same as the value of Y2 in the DCA message sent by the second terminal device to the first relay terminal device. Y2 carried in the DCA message sent by the first relay terminal device to the first terminal device is the fourth parameter.

[0248] Furthermore, the first terminal device may determine the first parameter by including the fourth parameter in the eighth message. For example:

[0249] The first parameter = the fourth parameter - 1, where the fourth parameter is the number of hops between the first terminal device and the second terminal device, and the first parameter is the number of hops between the first terminal device and the second terminal device minus one; or

[0250] The second parameter = the fourth parameter, in which case the fourth parameter is the number of relay terminal devices between the first terminal device and the second terminal device, and the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or the fourth parameter is the number of hops between the first terminal device and the second terminal device, and the first parameter is the number of hops between the first terminal device and the second terminal device; or

[0251] The first parameter=the fourth parameter+1. In this case, the fourth parameter is the number of relay terminal devices between the first terminal device and the second terminal device, and the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one.

[0252] It should be understood that the above method for determining the first parameter is only an example, and there are many other methods for determining the first parameter, which are not listed one by one in this application.

[0253] Optionally, after the first terminal device determines the first parameter, the first terminal device can send the first parameter to the second terminal device so that the first parameters of the second terminal device and the first terminal device are aligned, and then the appropriate timer is started when the second terminal device subsequently transmits information to the first terminal device.

[0254] Exemplarily, the first terminal device may send the first parameter to the second terminal device via an end-to-end (E2E) DCR message. It should be understood that after the first terminal device sends the E2E DCR message, the relay terminal device forwards it to the second terminal device.

[0255] Optionally, after the first terminal device determines the first parameter, the corresponding relationship between the first parameter and the second terminal device may be saved.

[0256] Based on the above communication method, the first terminal device can accurately determine the value of the first timer based on the first parameter, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met, thereby improving the communication performance of the relay scenario.

[0257] Based on the above embodiments, the present application also provides another communication method, which is applicable to the communication system shown in Figure 1. Referring to Figure 3, the specific process of the method may include:

[0258] Step 301: A first terminal device sends a first parameter to a network device. In response, the network device receives the first parameter from the first terminal device. The first parameter is related to the number of relay terminal devices between the first terminal device and a second terminal device, through which the first terminal device communicates with the second terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device.

[0259] Before the first terminal device sends the first parameter to the network device, the first terminal device determines the first parameter. For example, the method for the first terminal device to determine the first parameter can refer to the method for the first terminal device to determine the first parameter involved in the embodiment shown in FIG2a, which will not be repeated here.

[0260] For the description of the first parameter, please refer to the description in the embodiment shown in FIG. 2 a , which will not be repeated here.

[0261] In an optional implementation, the first terminal device may send the first parameter to the network device through the following method: the network device may send sidelink uplink information (SUI) to the network device to send the first parameter to the network device.

[0262] Optionally, the SUI may include a correspondence between the first parameter and the second terminal device. In one example, the SUI carries an identifier of the second terminal device and the first parameter. The identifier of the second terminal device may be a layer 2 identifier (L2 ID), a user info ID, or other terminal identifiers.

[0263] Step 302: The network device sends the value of the first timer to the first terminal device. Correspondingly, the first terminal device receives the value of the first timer from the network device.

[0264] In some embodiments, the network device may determine the value of the first timer based on the first parameter.

[0265] For example, the network device may also obtain the second parameter, or obtain the second parameter and the third parameter, and then determine the value of the first timer in combination with the first parameter. The description of the second parameter and the third parameter can refer to the relevant description involved in the example shown in Figure 2a, which will not be repeated here.

[0266] Furthermore, the method for the network device to determine the first parameter is similar to the method for the first terminal device to determine the first parameter, and they can refer to each other and will not be repeated here.

[0267] Exemplarily, the network device may send the value of the first timer to the first terminal device via an RRC message. Optionally, the RRC message may carry a correspondence between the second terminal device and the value of the first timer. For example, the RRC message may carry an identifier of the second terminal device and the value of the first timer, where the identifier of the second terminal device may be an L2 ID, a user info ID, or another terminal identifier.

[0268] After the first terminal device receives the value of the first timer, it starts or stops the first timer under certain conditions, or the operation performed by the first terminal device after the first timer expires can be referred to the relevant description involved in the embodiment shown in Figure 2a above, which will not be repeated here.

[0269] In some embodiments, the above process may be that the DU receives a first parameter from the first terminal device, the DU sends the first parameter to the CU, and the CU determines the value of the first timer based on the first parameter. Subsequently, the CU sends the value of the first timer to the DU, and the DU sends the value of the first timer to the first terminal device.

[0270] In the ORAN system, the above process may be that the O-DU receives the first parameter from the first terminal device, the O-DU sends the first parameter to the O-CU, and the O-CU determines the value of the first timer based on the first parameter. Subsequently, the O-CU sends the value of the first timer to the O-DU, and the O-DU sends the value of the first timer to the first terminal device.

[0271] Optionally, the operation of the O-CU in the ORAN system may be implemented by the O-CU-CP.

[0272] Exemplarily, the above method can be applied to a scenario where a network device perceives a U2U relay communication topology and the first terminal device is in a connected state.

[0273] Based on the above communication method, the first terminal device can report the first parameter to the network device so that the network device sends the value of the first timer to the first terminal device based on the first parameter, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met, thereby improving the communication performance of the relay scenario.

[0274] Based on the above embodiments, the present application also provides another communication method, which is applicable to the communication system shown in Figure 1. Referring to Figure 4, the specific process of the method may include:

[0275] Step 401: The first terminal device determines second information, where the second information includes a second parameter and a third parameter, or the second information includes a second parameter, where the second parameter includes a value of a second timer, and the third parameter includes an offset value.

[0276] Step 402: The first terminal device determines the value of the first timer according to the second information.

[0277] Exemplarily, the method may be applied to a scenario where a relay terminal device exists between the first terminal device and the second terminal device.

[0278] In an optional embodiment, the first terminal device determines the value of the first timer based on the second information. The method may be: when the second information includes the second parameter, the value of the first timer is a multiple of the value of the second timer; when the second information includes the second parameter and the third parameter, the value of the first timer is the sum of the value of the second timer and the offset value, or the value of the first timer is the difference between the multiple of the value of the second timer and the offset value.

[0279] Optionally, the multiple of the value of the first timer may be twice the value of the first timer, for example, the value of the first timer may be twice the value of the second timer.

[0280] For the related description of the first timer and the second timer, reference may be made to the related description in the embodiment shown in FIG2 a , which will not be described in detail here.

[0281] After the first terminal device determines the value of the first timer, the first terminal device may start the first timer after sending a sidelink reconfiguration message (RRCReconfigurationSidelink) to the second terminal device.

[0282] In some embodiments, the first terminal device determines that the first condition is met and stops the first timer; exemplarily, the first condition may include: the first terminal device receives a sidelink reconfiguration completion (RRCReconfigurationCompleteSidelink) message from the second terminal device; or, the first terminal device receives a first indication message from the first relay terminal device, the first indication message being used to instruct the first terminal device to retain the unicast connection with the first relay terminal device, or to instruct the first terminal device to release the unicast connection with the first relay terminal device, or to indicate that a radio link failure occurs between the first relay terminal device and the second terminal device, and the first terminal device communicates with the second terminal device through the first relay terminal device.

[0283] In other embodiments, if the first timer expires, the first terminal device performs one or more of the following operations: the first terminal device reselects the relay terminal device; or, the first terminal device retransmits the sidelink reconfiguration message; or, the first terminal device sends a unicast connection release message to the first relay terminal device; or, a message is sent to the first relay terminal device to instruct the first relay terminal device to keep the link activated with the second terminal device, and the first terminal device communicates with the second terminal device through the first relay terminal device; or, a second indication message is sent to the first relay terminal device, and the second indication message is used to indicate that the first timer has expired.

[0284] Based on the above communication method, the first terminal device can accurately determine the value of the first timer, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met, thereby improving the communication performance of the relay scenario.

[0285] Based on the above embodiments, the present application also provides another communication method, which is applicable to the communication system shown in Figure 1. Referring to Figure 5, the specific process of this method may include:

[0286] Step 501: The network device determines the value of a first timer.

[0287] Exemplarily, the network device can obtain the second parameter, or obtain the second parameter and the third parameter, and then determine the value of the first timer based on the second parameter or the second parameter and the third parameter. The specific method is similar to the method for the first terminal device to determine the value of the first timer. Please refer to the relevant description involved in the embodiment shown in Figure 4, which will not be described in detail here.

[0288] Step 502: The network device sends the value of the first timer to the first terminal device. Correspondingly, the first terminal device receives the value of the first timer from the network device.

[0289] Correspondingly, the subsequent operations after the first terminal device receives the first timing value can refer to the relevant description involved in the embodiment shown in Figure 4, which will not be repeated here.

[0290] In some embodiments, the above process may be that the CU determines the value of the first timer. Subsequently, the CU sends the value of the first timer to the DU, and the DU sends the value of the first timer to the first terminal device.

[0291] In the ORAN system, the above process may be that the O-CU determines the value of the first timer. Subsequently, the O-CU sends the value of the first timer to the O-DU, and the O-DU sends the value of the first timer to the first terminal device.

[0292] Optionally, the operation of the O-CU in the ORAN system may be implemented by the O-CU-CP.

[0293] Exemplarily, the method may be applied to a scenario where a relay terminal device exists between the first terminal device and the second terminal device.

[0294] Based on the above communication method, the first terminal device can obtain the value of the first timer from the network device, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met, thereby improving the communication performance of the relay scenario.

[0295] Based on the above embodiments, the present application also provides another communication method applicable to the communication system shown in FIG1 . This method can determine a first parameter to determine the value of a first timer. Referring to FIG6 , the specific process of this method may include:

[0296] Step 601: The first terminal device determines a first parameter, where the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device.

[0297] Among them, the relevant description of the first parameter and the method for the first terminal device to determine the first parameter can be found in the relevant description involved in the embodiment shown in Figure 2a, which will not be repeated here.

[0298] Optionally, the first terminal device may further perform step 602: the first terminal device sends a first parameter to the second terminal device.

[0299] Based on the above communication method, the first terminal device can accurately determine the first parameter, and then subsequently determine the value of the first timer based on the first parameter, thereby realizing the timer configuration in the relay scenario, so that the subsequent first terminal device can correctly start or stop the timer when the conditions are met.

[0300] Based on the above embodiments, the present application also provides a communication device. Referring to FIG7 , the communication device 700 may include a processing unit 702. Optionally, the communication device may also include a transceiver unit 701. Transceiver unit 701 may be used to send and receive information, etc. Processing unit 702 may control and manage the actions of communication device 700. Processing unit 702 may also control operations performed by transceiver unit 701.

[0301] Exemplarily, the communication device 700 may be the first terminal device, the processor of the first terminal device, or a chip, or a chip system, or a functional module, etc. in the above-mentioned embodiment. Alternatively, the communication device 700 may also be the network device, the processor of the network device, or a chip, or a chip system, or a functional module, etc. in the above-mentioned embodiment.

[0302] In one embodiment, when the communication device 700 is used to implement the functions of the first terminal device in the embodiment shown in FIG. 2a , the communication device 700 may include: a processing unit 702 may be used to determine first information and determine a value of a first timer based on the first information. The first information includes a first parameter; the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, through which the first terminal device communicates with the second terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device.

[0303] The value of the first timer is positively correlated with the first parameter.

[0304] In an optional implementation manner, the first information further includes a second parameter and a third parameter, or the first information further includes the second parameter, the second parameter includes the value of the second timer, and the third parameter includes the offset value.

[0305] Exemplarily, when the first information also includes a second parameter and a third parameter, the value of the first timer is positively correlated with the first parameter, the second parameter and the third parameter, or the value of the first timer is positively correlated with the first parameter and the second parameter and negatively correlated with the third parameter; when the first information also includes a second parameter, the value of the first timer is positively correlated with the first parameter and the second parameter.

[0306] In an optional implementation, when determining the value of the first timer according to the first information, the processing unit 702 is configured to:

[0307] The value of the first timer = T0 + N * T1; or

[0308] The value of the first timer = N*T0+T1; or

[0309] The value of the first timer = N*T0-T1; or

[0310] The value of the first timer = N*(T0+T1); or

[0311] The value of the first timer = N*(T0-T1); or

[0312] The value of the first timer = T0 + (N-1) * T1; or

[0313] The value of the first timer = (N-1)*T0+T1; or

[0314] The value of the first timer = (N-1)*T0-T1; or

[0315] The value of the first timer = (N-1)*(T0+T1); or

[0316] The value of the first timer = (N-1)*(T0-T1); or

[0317] The value of the first timer = (N+1)*T0; or

[0318] The value of the first timer = N*T0;

[0319] Wherein, T0 is the value of the second timer, and T0 is a positive number; T1 is the offset value, and T1 is a number greater than or equal to 0; N is the first parameter, and the first parameter is a positive integer.

[0320] In one possible manner, the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, including: the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one.

[0321] In another possible embodiment, the first parameter is related to the number of hops between the first terminal device and the second terminal device, including: the first parameter is the number of hops between the first terminal device and the second terminal device; or the first parameter is the number of hops between the first terminal device and the second terminal device minus one.

[0322] In one example, the processing unit 702 is also used to determine whether a first condition is met and stop the first timer; wherein the first condition includes: receiving a first indication information from the first relay terminal device through the transceiver unit 701, the first indication information is used to instruct the first terminal device to retain the unicast connection between the first relay terminal device, or to instruct the first terminal device to release the unicast connection between the first relay terminal device and the first relay terminal device, or to indicate that a wireless link failure occurs between the first relay terminal device and the third terminal device, the third terminal device is the second terminal device or the third terminal device is a relay terminal device between the first relay terminal device and the second terminal device, the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device.

[0323] In another example, the processing unit 702 is also used to perform one or more of the following operations if the first timer expires: sending a message to the first relay terminal device through the transceiver unit 701 to indicate that the link between the first relay terminal device and the fourth terminal device remains activated, the first relay terminal device is one of the relay terminal devices, the first relay terminal device communicates directly with the first terminal device, the fourth terminal device is the second terminal device or the fourth terminal device is a relay terminal device between the first relay terminal device and the second terminal device; or, sending a second indication information to the first relay terminal device through the transceiver unit 701, the second indication information being used to indicate that the first timer has expired.

[0324] Exemplarily, when determining the first parameter included in the first information, the processing unit 702 is used to: determine the first parameter based on a fourth parameter, the fourth parameter being the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter being the number of relay terminal devices between the first relay terminal device and the second terminal device, or the fourth parameter being the number of relay terminal devices or the number of hops between the first terminal device and the second terminal device, or the fourth parameter including the identification of one or more relay terminal devices; wherein the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device.

[0325] Optionally, the processing unit 702 is further configured to determine a fourth parameter.

[0326] In one possible manner, when determining the fourth parameter, the processing unit 702 is configured to: receive the fourth parameter from the first relay terminal device through the transceiver unit 701 .

[0327] In another possible manner, when determining the fourth parameter, the processing unit 702 is configured to: receive a first value of the fourth parameter through the transceiver unit 701 .

[0328] Optionally, the processing unit 702 may also be configured to send a second value of the fourth parameter through the transceiver unit 701 , where the second value is used to determine the first value.

[0329] Another possible way is that when determining the fourth parameter, the processing unit 702 is used to: send the fifth parameter and the sixth parameter through the transceiver unit 701, the fifth parameter represents the maximum number of relay terminal devices, and the sixth parameter represents the remaining number of relay terminal devices, or the fifth parameter represents the maximum number of hops, and the sixth parameter represents the remaining number of hops; receive the fourth parameter through the transceiver unit 701, and the fourth parameter is determined based on the fifth parameter and the sixth parameter.

[0330] In one example, when the processing unit 702 determines the first parameter based on the fourth parameter, it is used to: when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter; or when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus two.

[0331] Optionally, the transceiver unit 701 can be used to send the first parameter to the second terminal device.

[0332] In another embodiment, when the communication device 700 is used to implement the functions of the first terminal device in the embodiment shown in FIG. 3 , it may include: a transceiver unit 701 configured to send a first parameter to a network device and receive a first timer value from the network device. The first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, through which the first terminal device communicates with the second terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device. A processing unit 702 is configured to control the above-described operations of the transceiver unit 701.

[0333] The value of the first timer is determined based on the first parameter.

[0334] In one example, the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, including: the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or, the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one.

[0335] In another example, the first parameter is related to the number of hops between the first terminal device and the second terminal device, including: the first parameter is the number of hops between the first terminal device and the second terminal device; or the first parameter is the number of hops between the first terminal device and the second terminal device minus one.

[0336] In one possible embodiment, the processing unit 702 is also used to determine whether the first condition is met and stop the first timer; wherein the first condition includes: receiving first indication information from the first relay terminal device through the transceiver unit 701, the first indication information is used to instruct the first terminal device to retain the unicast connection between the first relay terminal device, or to instruct the first terminal device to release the unicast connection between the first relay terminal device and the first relay terminal device, or to indicate that a wireless link failure occurs between the first relay terminal device and the third terminal device, the third terminal device is the second terminal device or the third terminal device is a relay terminal device between the first relay terminal device and the second terminal device, the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device.

[0337] In another possible embodiment, the processing unit 702 is also used to perform one or more of the following operations if the first timer expires: sending a message to the first relay terminal device through the transceiver unit 701 to indicate that the link between the first relay terminal device and the fourth terminal device remains activated, the first relay terminal device is one of the relay terminal devices, the first relay terminal device communicates directly with the first terminal device, the fourth terminal device is the second terminal device or the fourth terminal device is a relay terminal device between the first relay terminal device and the second terminal device; or, sending a second indication information to the first relay terminal device, the second indication information is used to indicate that the first timer has expired.

[0338] Optionally, the processing unit 702 may also be configured to determine a first parameter.

[0339] Exemplarily, when the processing unit 702 determines the first parameter, it is used to: determine the first parameter based on a fourth parameter, where the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices or the number of hops between the first terminal device and the second terminal device, or the fourth parameter includes the identifier of one or more relay terminal devices; wherein the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device.

[0340] In one example, the processing unit 702 is further configured to determine a fourth parameter.

[0341] In one possible manner, when determining the fourth parameter, the processing unit 702 is configured to: receive the fourth parameter from the first relay terminal device through the transceiver unit 701 .

[0342] In another possible manner, when determining the fourth parameter, the processing unit 702 is configured to: receive a first value of the fourth parameter through the transceiver unit 701 .

[0343] Optionally, the processing unit 702 may also be configured to send a second value of the fourth parameter through the transceiver unit 701 , where the second value is used to determine the first value.

[0344] Another possible way is that when determining the fourth parameter, the processing unit 702 is used to: send the fifth parameter and the sixth parameter through the transceiver unit 701, the fifth parameter represents the maximum number of relay terminal devices, and the sixth parameter represents the remaining number of relay terminal devices, or the fifth parameter represents the maximum number of hops, and the sixth parameter represents the remaining number of hops; receive the fourth parameter through the transceiver unit 701, and the fourth parameter is determined based on the fifth parameter and the sixth parameter.

[0345] In one example, when determining the first parameter based on the fourth parameter, the processing unit 702 is configured to: when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter; or

[0346] When the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus two.

[0347] Optionally, the transceiver unit 701 may also be configured to send the first parameter to the second terminal device.

[0348] In another embodiment, when the communication device 700 is used to implement the functions of the network device in the embodiment shown in FIG. 3 , it may include: a transceiver unit 701 configured to receive a first parameter from a first terminal device and send a first timer value to the first terminal device. The first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, through which the first terminal device communicates with the second terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device. A processing unit 702 may be configured to control the transceiver unit 701's transceiver operations.

[0349] In an example, the processing unit 702 may also be configured to determine a value of the first timer according to the first parameter.

[0350] In one possible manner, the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, including: the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or the first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one.

[0351] In another possible embodiment, the first parameter is related to the number of hops between the first terminal device and the second terminal device, including: the first parameter is the number of hops between the first terminal device and the second terminal device; or the first parameter is the number of hops between the first terminal device and the second terminal device minus one.

[0352] In another embodiment, when the communication device 700 is used to implement the functions of the first terminal device in the embodiment shown in FIG. 4 , the communication device 700 may include: a processing unit 702 configured to determine second information and determine a value of the first timer based on the second information. The second information includes a second parameter and a third parameter, or the second information includes the second parameter, the second parameter includes the value of the second timer, and the third parameter includes an offset value;

[0353] Exemplarily, when the processing unit 702 determines the value of the first timer based on the second information, it is used to: when the second information includes the second parameter, the value of the first timer = a multiple of the value of the second timer; when the second information includes the second parameter and the third parameter, the value of the first timer = the sum of the value of the second timer and the offset value, or the value of the first timer = the difference between the multiple of the value of the second timer and the offset value.

[0354] In one possible embodiment, the processing unit 702 can also be used to determine whether the first condition is met and stop the first timer; wherein the first condition includes: receiving first indication information from the first relay terminal device through the transceiver unit 701, the first indication information is used to instruct the first terminal device to retain the unicast connection between the first relay terminal device, or to instruct the first terminal device to release the unicast connection between the first relay terminal device, or to indicate that a wireless link failure occurs between the first relay terminal device and the second terminal device, and the first terminal device communicates with the second terminal device through the first relay terminal device.

[0355] In another possible embodiment, the processing unit 702 can also be used to perform one or more of the following operations if the first timer expires: sending a message to the first relay terminal device through the transceiver unit 701 to instruct the first relay terminal device to keep the link activated with the second terminal device, and the first terminal device communicates with the second terminal device through the first relay terminal device; or sending second indication information to the first relay terminal device through the transceiver unit 701, and the second indication information is used to indicate that the first timer has expired.

[0356] In another embodiment, when the communication device 700 is used to implement the function of the first terminal device in the embodiment shown in Figure 6 above, it may include: the processing unit 702 is used to determine a first parameter, the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device.

[0357] Exemplarily, when determining the first parameter, the processing unit 702 is used to: determine the first parameter based on a fourth parameter, where the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices or the number of hops between the first terminal device and the second terminal device, or the fourth parameter includes the identification of one or more relay terminal devices; wherein the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device.

[0358] In one example, the processing unit 702 is further configured to determine a fourth parameter.

[0359] In one possible manner, when determining the fourth parameter, the processing unit 702 is configured to: receive the fourth parameter from the first relay terminal device through the transceiver unit 701 .

[0360] In another possible manner, when determining the fourth parameter, the processing unit 702 is configured to: receive a first value of the fourth parameter through the transceiver unit 701 .

[0361] Optionally, the processing unit 702 may also be configured to send a second value of the fourth parameter through the transceiver unit 701 , where the second value is used to determine the first value.

[0362] Another possible way is that when determining the fourth parameter, the processing unit 702 is used to: send the fifth parameter and the sixth parameter through the transceiver unit 701, the fifth parameter represents the maximum number of relay terminal devices, and the sixth parameter represents the remaining number of relay terminal devices, or the fifth parameter represents the maximum number of hops, and the sixth parameter represents the remaining number of hops; receive the fourth parameter through the transceiver unit 701, and the fourth parameter is determined based on the fifth parameter and the sixth parameter.

[0363] In one example, when determining the first parameter based on the fourth parameter, the processing unit 702 is configured to: when the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter; or

[0364] When the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or, when the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus two.

[0365] Optionally, the transceiver unit 701 may also be configured to send the first parameter to the second terminal device.

[0366] It should be noted that the division of units in the embodiments of the present application is schematic and is merely a logical functional division. In actual implementation, other division methods may be used. The functional units in the embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0367] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or 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 enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0368] Based on the above embodiments, the present application also provides a communication device. Referring to FIG8 , the communication device 800 may include a processor 802. Optionally, the communication device 800 may further include a transceiver 801 and / or a memory 803. The memory 803 may be located within the communication device 800 or external to the communication device 800. The processor 802 may control the transceiver 801 to receive and send messages, etc.

[0369] Specifically, processor 802 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. Processor 802 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0370] Transceiver 801, processor 802, and memory 803 are interconnected. Optionally, transceiver 801, processor 802, and memory 803 are interconnected via bus 804; bus 804 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. Buses can be categorized as address buses, data buses, control buses, and the like. For ease of illustration, FIG8 shows only one thick line, but this does not imply that there is only one bus or only one type of bus.

[0371] In an optional embodiment, memory 803 is used to store programs, etc. Specifically, the programs may include program code, which includes computer operating instructions. Memory 803 may include RAM or non-volatile memory, such as one or more disk drives. Processor 802 executes the application programs stored in memory 803 to implement the above functions, thereby realizing the functions of communication device 800.

[0372] In one embodiment, when the communication device 800 performs the functions of the first terminal device in the method embodiment shown in FIG. 2a , the processor 802 may implement the operations performed by the first terminal device in the method embodiment shown in FIG. For specific details, please refer to the description of the embodiment shown in FIG. 2a , and will not be described in detail here.

[0373] In one embodiment, when the communication device 800 functions as the first terminal device in the method embodiment shown in FIG. 3 , the transceiver 801 can implement the transceiver operations performed by the first terminal device in the method embodiment shown in FIG. 3 ; the processor 802 can implement other operations performed by the first terminal device in the method embodiment shown in FIG. 3 , except for the transceiver operations. For specific details, please refer to the description of the embodiment shown in FIG. 3 , and will not be described in detail here.

[0374] In one embodiment, when the communication device 800 functions as a network device in the method embodiment shown in FIG3 , the transceiver 801 can implement the transceiver operations performed by the network device in the method embodiment shown in FIG3 ; the processor 802 can implement other operations performed by the network device in the method embodiment shown in FIG3 , except for the transceiver operations. For specific details, please refer to the relevant description of the embodiment shown in FIG3 , and will not be described in detail here.

[0375] In one embodiment, when the communication device 800 functions as the first terminal device in the method embodiment shown in FIG. 4 , the processor 802 may implement the operations performed by the first terminal device in the method embodiment shown in FIG. For specific details, please refer to the description of the embodiment shown in FIG. 4 , and will not be described in detail here.

[0376] In one embodiment, when the communication device 800 functions as the first terminal device in the method embodiment shown in FIG. 5 , the transceiver 801 can implement the transceiver operations performed by the first terminal device in the method embodiment shown in FIG. 5 ; the processor 802 can implement other operations performed by the first terminal device in the method embodiment shown in FIG. 5 , except for the transceiver operations. For specific details, please refer to the description of the embodiment shown in FIG. 5 , and will not be described in detail here.

[0377] In one embodiment, when the communication device 800 functions as a network device in the method embodiment shown in FIG5 , the transceiver 801 can implement the transceiver operations performed by the network device in the method embodiment shown in FIG5 ; the processor 802 can implement other operations performed by the network device in the method embodiment shown in FIG5 , except for the transceiver operations. For specific details, please refer to the relevant description of the embodiment shown in FIG5 , and will not be described in detail here.

[0378] In one embodiment, when the communication device 800 functions as the first terminal device in the method embodiment shown in FIG. 6 , the transceiver 801 can implement the transceiver operations performed by the first terminal device in the method embodiment shown in FIG. 6 ; the processor 802 can implement other operations performed by the first terminal device in the method embodiment shown in FIG. 6 , except for the transceiver operations. For specific details, please refer to the description of the embodiment shown in FIG. 6 , and will not be described in detail here.

[0379] Based on the above embodiments, an embodiment of the present application provides a communication system, which may include the first terminal device, the second terminal device, and the relay terminal device between the first terminal device and the second terminal device involved in the above embodiments.

[0380] An embodiment of the present application further provides a computer-readable storage medium, which is used to store a computer program. When the computer program is executed by a computer, the computer can implement the communication method provided by the above method embodiment.

[0381] An embodiment of the present application further provides a computer program product, which is used to store a computer program. When the computer program is executed by a computer, the computer can implement the communication method provided by the above method embodiment.

[0382] An embodiment of the present application also provides a chip, including a processor, which is coupled to a memory and is used to call a program in the memory so that the chip implements the communication method provided by the above method embodiment.

[0383] An embodiment of the present application also provides a chip, which is coupled to a memory and is used to implement the communication method provided in the above method embodiment.

[0384] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0385] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or box in the flow chart and / or block diagram, as well as the combination of the flow chart and / or box in the flow chart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flow charts and / or one or more boxes in the block diagram.

[0386] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0387] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0388] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: include: Sending a first parameter to a network device, where the first parameter is related to the number of relay terminal devices between a first terminal device and a second terminal device, through which the first terminal device communicates with the second terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device; A value of a first timer is received from the network device.

2. The method according to claim 1, characterized in that The value of the first timer is determined based on the first parameter.

3. The method according to claim 1 or 2, characterized in that The method further comprises: The first parameter is determined.

4. The method according to claim 3, characterized in that Determining the first parameter includes: determining the first parameter according to a fourth parameter, wherein the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, or the fourth parameter is the number of the relay terminal devices or the number of hops between the first terminal device and the second terminal device, or the fourth parameter includes identifications of one or more relay terminal devices; The first relay terminal device is one of the relay terminal devices, and the first relay terminal device directly communicates with the first terminal device.

5. A communication method, characterized in that: include: receiving a first parameter from a first terminal device, wherein the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, through which the first terminal device communicates with the second terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device; Send the value of the first timer to the first terminal device.

6. The method according to claim 5, characterized in that The method further comprises: A value of a first timer is determined according to the first parameter.

7. A communication method, characterized in that: include: Determine first information, the first information including a first parameter; the first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, the first terminal device communicates with the second terminal device through the relay terminal device, or the first parameter is related to the number of hops between the first terminal device and the second terminal device; A value of a first timer is determined according to the first information.

8. The method according to claim 7, characterized in that The value of the first timer is positively correlated with the first parameter.

9. The method according to claim 7 or 8, characterized in that The first information further includes a second parameter and a third parameter, or the first information further includes the second parameter, the second parameter includes a value of a second timer, and the third parameter includes an offset value.

10. The method according to claim 9, characterized in that When the first information further includes the second parameter and the third parameter, the value of the first timer is positively correlated with the first parameter, the second parameter and the third parameter, or the value of the first timer is positively correlated with the first parameter and the second parameter and negatively correlated with the third parameter; When the first information further includes the second parameter, the value of the first timer is positively correlated with the first parameter and the second parameter.

11. The method according to claim 9 or 10, characterized in that Determining a value of the first timer according to the first information includes: The value of the first timer = T0 + N*T1; or The value of the first timer = N*T0+T1; or The value of the first timer = N*T0-T1; or The value of the first timer = N*(T0+T1); or The value of the first timer = N*(T0-T1); or The value of the first timer = T0 + (N-1) * T1; or The value of the first timer = (N-1)*T0+T1; or The value of the first timer = (N-1)*T0-T1; or The value of the first timer = (N-1)*(T0+T1); or The value of the first timer = (N-1)*(T0-T1); or The value of the first timer=(N+1)*T0; or The value of the first timer = N*T0; Among them, T0 is the value of the second timer, and T0 is a positive number; T1 is the offset value, and T1 is a number greater than or equal to 0; N is the first parameter, and the first parameter is a positive integer.

12. The method according to any one of claims 7 to 11, characterized in that: Determining the first parameter included in the first information includes: determining the first parameter according to a fourth parameter, wherein the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, or the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, or the fourth parameter is the number of the relay terminal devices or the number of hops between the first terminal device and the second terminal device, or the fourth parameter includes identifications of one or more relay terminal devices; The first relay terminal device is one of the relay terminal devices, and the first relay terminal device directly communicates with the first terminal device.

13. The method according to any one of claims 1-4, 5, 6, 7-12, characterized in that: The first parameter is related to the number of relay terminal devices between the first terminal device and the second terminal device, including: The first parameter is the number of relay terminal devices between the first terminal device and the second terminal device; or The first parameter is the number of relay terminal devices between the first terminal device and the second terminal device plus one; The first parameter is related to the number of hops between the first terminal device and the second terminal device, including: The first parameter is the number of hops between the first terminal device and the second terminal device; or The first parameter is the number of hops between the first terminal device and the second terminal device minus one.

14. The method according to any one of claims 1 to 4 and 7 to 12, characterized in that: The method further comprises: Determining that a first condition is met, stopping the first timer; The first condition includes: First indication information is received from a first relay terminal device, wherein the first indication information is used to instruct the first terminal device to retain a unicast connection with the first relay terminal device, or to instruct the first terminal device to release a unicast connection with the first relay terminal device, or to indicate that a wireless link failure occurs between the first relay terminal device and a third terminal device, wherein the third terminal device is the second terminal device or the third terminal device is a relay terminal device between the first relay terminal device and the second terminal device, the first relay terminal device is one of the relay terminal devices, and the first relay terminal device communicates directly with the first terminal device.

15. The method according to any one of claims 1 to 4, 7 to 12, characterized in that: The method further comprises: If the first timer expires, perform one or more of the following operations: Sending a message to a first relay terminal device for instructing the first relay terminal device to maintain a link activation with a fourth terminal device, where the first relay terminal device is one of the relay terminal devices, the first relay terminal device directly communicates with the first terminal device, and the fourth terminal device is the second terminal device or the fourth terminal device is a relay terminal device between the first relay terminal device and the second terminal device; or Send second indication information to the first relay terminal device, where the second indication information is used to indicate that the first timer has expired.

16. The method according to claim 4 or 12, characterized in that: The method further comprises: The fourth parameter is determined.

17. The method according to claim 16, characterized in that Determining the fourth parameter includes: Receive the fourth parameter from the first relay terminal device.

18. The method according to claim 16, characterized in that Determining the fourth parameter includes: A first value of the fourth parameter is received.

19. The method according to claim 18, characterized in that The method further comprises: A second value of the fourth parameter is sent, wherein the second value is used to determine the first value.

20. The method of claim 16, wherein: Determining the fourth parameter includes: Send the fifth parameter and the sixth parameter, the fifth parameter indicates the maximum number of relay terminal devices, and the sixth parameter indicates the remaining relay The number of terminal devices, or the fifth parameter indicates the maximum number of hops, and the sixth parameter indicates the remaining number of hops; The fourth parameter is received, where the fourth parameter is determined based on the fifth parameter and the sixth parameter.

21. The method according to any one of claims 4, 12, 16-20, characterized in that: Determining the first parameter according to the fourth parameter includes: When the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter; or When the fourth parameter is the number of hops between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or When the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus one; or When the fourth parameter is the number of relay terminal devices between the first relay terminal device and the second terminal device, the first parameter is equal to the fourth parameter plus two.

22. The method according to any one of claims 1-4, 7-21, characterized in that: The method further comprises: Send the first parameter to the second terminal device.

23. A communication method, characterized in that: include: Determine second information, where the second information includes a second parameter and a third parameter, or the second information includes the second parameter, the second parameter includes a value of a second timer, and the third parameter includes an offset value; The value of the first timer is determined according to the second information.

24. The method of claim 23, wherein: Determining a value of the first timer according to the second information includes: When the second information includes the second parameter, the value of the first timer is a multiple of the value of the second timer; When the second information includes the second parameter and the third parameter, the value of the first timer is the sum of the value of the second timer and the offset value, or the value of the first timer is the difference between a multiple of the value of the second timer and the offset value.

25. The method according to claim 23 or 24, characterized in that The method further comprises: Determining that a first condition is met, stopping the first timer; The first condition includes: A first indication message is received from a first relay terminal device, wherein the first indication message is used to instruct the first terminal device to retain a unicast connection with the first relay terminal device, or to instruct the first terminal device to release a unicast connection with the first relay terminal device, or to indicate that a wireless link failure occurs between the first relay terminal device and a second terminal device, and the first terminal device communicates with the second terminal device through the first relay terminal device.

26. The method according to claim 23 or 24, characterized in that The method further comprises: If the first timer expires, perform one or more of the following operations: sending a message to the first relay terminal device for instructing the first relay terminal device to keep the link between the first relay terminal device and the second terminal device activated, so that the first terminal device communicates with the second terminal device through the first relay terminal device; or Send second indication information to the first relay terminal device, where the second indication information is used to indicate that the first timer has expired.

27. A communication device, characterized in that: The method comprises a module or unit for executing the method described in any one of claims 1 to 4 and 13 to 22, or comprises a module or unit for executing the method described in any one of claims 7 to 22, or comprises a module or unit for executing the method described in any one of claims 23 to 26.

28. A communication device, characterized in that: The method comprises a module or a unit for executing the method according to any one of claims 5 to 6 and 13.

29. A communication device, characterized in that: comprising a processor, wherein: The processor is coupled to the memory, and is used to call computer instructions in the memory to execute the method according to any one of claims 1-4, 13-22, or the method according to any one of claims 7-22, or the method according to any one of claims 23-26.

30. A communication device, characterized in that: comprising a processor, wherein: The processor is coupled to the memory, and is used to call computer instructions in the memory to execute the method according to any one of claims 5-6 and 13.

31. A communication system, characterized in that: Comprising the communication device as claimed in claim 27, or comprising the communication device as claimed in claim 27 and the communication device as claimed in claim 28, or comprising the communication device as claimed in claim 29, or comprising the communication device as claimed in claim 29 and the communication device as claimed in claim 30.

32. 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 described in any one of claims 1-4, 13-22, or the method as described in any one of claims 5-6, 13, or the method as described in any one of claims 7-22, or the method as described in any one of claims 23-26.

33. A computer program product, characterized in that Contains instructions, which, when executed on a computer, cause the method according to any one of claims 1-4, 13-22, or the method according to any one of claims 5-6, 13 to be executed, or the method according to any one of claims 7-22 to be executed, or the method according to any one of claims 23-26 to be executed.

34. A chip, characterized in that: The chip is coupled to the memory and is used to read and execute program instructions stored in the memory to implement the method as described in any one of claims 1-4, 13-22, or the method as described in any one of claims 5-6, 13, or the method as described in any one of claims 7-22, or the method as described in any one of claims 23-26.

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