Communication method and apparatus

Abstract

[0009] The present application provides a communication method and apparatus for solving the problem that a change in 5GS clock information cannot be determined in a time provision process. The communication method and apparatus can be used in a 5G system. The method includes: a first network element determining that quality information of a first clock needs to be acquired; and sending first indication information to a second network element, where the first clock is a reference clock of a wireless communication system, and the first indication information indicates that the quality information of the first clock should be acquired. The first network element receives the quality information of the first clock from the second network element and sends the quality information of the first clock to a terminal device.

Description

[Technical Field]

[0001] TECHNICAL FIELD Embodiments of this application relate to the field of communications, and in particular to communication methods and devices. [Background technology]

[0002] The time provision capability of a 5th generation (5G) network is a network function that can be exposed to the outside world. The time provision capability exposure specified in Release 17 (R17) can be activated and deactivated by an application function (AF) to perform time provisioning to terminal devices.

[0003] Specifically, the AF sends an access stratum clock information time provision request to a network exposure function (NEF), which then forwards the access stratum clock information time provision request to a time sensitive communication and time synchronization function (TSCTSF). After receiving the access stratum clock information time provision request, the TSCTSF activates the time provisioning capability of the access network device, calculates the air interface time provisioning error of the access network device, and sends a time provisioning instruction and the air interface time provisioning error of the access network device to a policy control function (PCF). The PCF updates an access and mobility (AMF) policy using an access and mobility management function (AM) and sends a time provisioning instruction and the air interface time provisioning error of the access network device to the AMF, which indicates that the access network device will start providing time with a certain error to the terminal device and provide access stratum clock information to the terminal device. When performing a time provision service to a terminal device, the TSCTSF may alternatively obtain clock subscription information of the terminal device from a unified data management (UDM) and refer to the clock subscription information of the terminal device to complete time provision to the terminal device.

[0004] Currently, in addition to the above-mentioned method in which the AF triggers the access network device to send access stratum clock information, the terminal device can further obtain access stratum clock information by using a system information block (SIB) message broadcast by the access network device, or can request access stratum clock information by sending a radio resource control (RRC) message to the access network device.

[0005] However, in the above-mentioned time provision process, the terminal device can only obtain 5th generation system (5GS) clock information synchronized by the access network device and cannot determine changes to the 5GS clock information. As a result, the terminal device cannot compare the 5GS clock with other available clocks and cannot select the most appropriate and accurate clock as the grandmaster. Summary of the Invention [Means for solving the problem]

[0006] The embodiments of the present application provide a communication method and apparatus to solve the problem that a terminal device cannot determine changes in 5GS clock information.

[0007] To achieve the aforementioned objectives, the following technical solutions are used in the embodiments of this application.

[0008] According to a first aspect, a communication method is provided. The method may be executed by a first network element, or may be executed by a component of the first network element, such as a processor, chip, or chip system of the first network element, or may be implemented by a logic module or software capable of realizing all or part of the functions of the first network element. The following describes an example in which the method is executed by the first network element. The communication method includes: the first network element determining that quality information of a first clock needs to be acquired; the first clock is a reference clock of a wireless communication system; the first network element transmitting first indication information to a second network element; the first indication information indicating that the quality information of the first clock should be acquired; the first network element receiving the quality information of the first clock from the second network element and transmitting the quality information of the first clock to a terminal device.

[0009] In the process of providing time to the terminal device based on the communication method, the first network element can use the first instruction information to trigger the second network element to obtain quality information of the first clock, so that the first network element can obtain the quality information of the first clock from the second network element and provide the quality information of the first clock to the terminal device. Then, after obtaining the quality information of the first clock, for example, the terminal device can compare the first clock with another available clock based on the quality information of the first clock to select a better and more accurate clock as a grandmaster.

[0010] In a possible design solution, the first network element is a mobility management network element. The first network element's determination that quality information of the first clock needs to be acquired may include the first network element sending, to the access network device, information used to confirm whether the access network device has the quality information of the first clock. The first network element receives an acknowledgement from the access network device. The acknowledgement indicates that the access network device does not have the quality information of the first clock. The first network element determines, based on the acknowledgement, that the quality information of the first clock needs to be acquired. In this way, if the quality information of the first clock is not deployed on the access network device, the mobility management network element can trigger a procedure to acquire the quality information of the first clock to enable the terminal device to acquire the quality information of the first clock.

[0011] In a possible design solution, the first network element transmitting the quality information of the first clock to the terminal device may include the first network element transmitting a non-access stratum NAS message to the terminal device. The NAS message includes the quality information of the first clock. In this way, if the first network element is a mobility management network element, after acquiring the quality information of the first clock, the first network element can transmit the quality information of the first clock to the terminal device in a transparent transmission manner. This can reduce signaling overhead and improve the speed at which the terminal device acquires the quality information of the first clock.

[0012] Furthermore, the communication method provided in this embodiment of the present application may further include the first network element receiving second instruction information from the terminal device. The second instruction information indicates that the terminal device requests to stop providing time. The first network element sends third instruction information to the access network device. The third instruction information indicates that the access network device stops providing time to the terminal device. In this way, when the first network element is a mobility management network element, the first network element can control the access network device to stop providing time to the terminal device based on the time provision stop instruction sent by the terminal device, thereby achieving the purpose of stopping providing time to the terminal device.

[0013] In a possible design solution, the second network element may be an operation, administration and maintenance network element or a time synchronization network element.

[0014] In another possible design solution, the first network element is an access network device. The first network element's determination that quality information of the first clock needs to be acquired may include the first network element receiving a time provision request from the terminal device. The time provision request includes first indication information. The first network element determines whether the first network element has the quality information of the first clock based on the first indication information. If the first network element determines that it does not have the quality information of the first clock, the first network element determines that the quality information of the first clock needs to be acquired. In this way, in a scenario where the terminal device autonomously requests time provision, the access network device can trigger a procedure to acquire the quality information of the first clock to enable the terminal device to acquire the quality information of the first clock.

[0015] Furthermore, the communication method provided in this embodiment of the present application may further include the first network element receiving second instruction information from the terminal device. The second instruction information indicates that the terminal device requests to stop providing time. The first network element sends fourth instruction information to the terminal device. The fourth instruction information indicates that the first network element has stopped providing time to the terminal device. In this way, when the first network element is an access network device, the first network element can autonomously determine to stop providing time to the terminal device based on the time provision stop instruction sent by the terminal device.

[0016] Optionally, the fourth indication information may be carried in an RRC message.

[0017] In a possible design solution, the first network element transmitting the quality information of the first clock to the terminal device may include the first network element transmitting a radio resource control (RRC) message to the terminal device, wherein the RRC message may include the quality information of the first clock.

[0018] In another possible design solution, the first network element transmitting the quality information of the first clock to the terminal device may include the first network element transmitting a system message to the terminal device, wherein the system message may include the quality information of the first clock.

[0019] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0020] According to a second aspect, a communication method is provided. The method may be executed by a second network element, or may be executed by a component of the second network element, such as a processor, chip, or chip system of the second network element, or may be implemented by a logic module or software capable of realizing all or part of the functions of the second network element. Hereinafter, an example in which the method is executed by the second network element will be described. The communication method includes the second network element receiving first indication information from a first network element. The first indication information indicates that quality information of a first clock should be acquired, the first clock being a reference clock of a wireless communication system. The second network element acquires the quality information of the first clock based on the first indication information. The second network element transmits the quality information of the first clock to the first network element.

[0021] In a possible design solution, the second network element is a time synchronization network element. The second network element obtaining the quality information of the first clock based on the first indication information may include the second network element sending a first message to the user plane network element based on the first indication information. The first message is used to request the quality information of the first clock. The second network element receives the quality information of the first clock from the user plane network element.

[0022] In another possible design solution, the second network element may be a time-synchronization network element. The second network element obtaining the quality information of the first clock based on the first indication information may include the second network element sending a second message to the operation, management, and maintenance network element based on the first indication information. The second message is used to request the quality information of the first clock. The second network element receives the quality information of the first clock from the operation, management, and maintenance network element.

[0023] Furthermore, the communication method provided in this embodiment of the present application may further include: the second network element receiving second instruction information from the terminal device. The second instruction information indicates that the terminal device requests to stop providing time. The second network element sends third instruction information to the access network device. The third instruction information indicates that the access network device stops providing time to the terminal device.

[0024] Optionally, the first network element is a mobility management network element or an access network device.

[0025] In a possible design solution, the first network element is a mobility management network element and the second network element is an operation, administration and maintenance network element.

[0026] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0027] For the technical effects of the communication method according to the second aspect, please refer to the technical effects of the communication method according to the first aspect, and the details will not be described again in this specification.

[0028] According to a third aspect, a communication method is provided. The method may be executed by a terminal device, or may be executed by a component of the terminal device, such as a processor, chip, or chip system of the terminal device, or may be implemented by a logic module or software capable of realizing all or part of the functions of the terminal device. The following describes an example in which the method is executed by the terminal device. The communication method includes the terminal device receiving quality information of a first clock from a first network element. The first clock is a reference clock of a wireless communication system. The terminal device determines, based on the quality information of the first clock, that the access network device needs to continue providing time to the terminal device. Alternatively, the terminal device determines, based on the quality information of the first clock, that the access network device needs to stop providing time to the terminal device.

[0029] In a possible design solution, the first network element is an access network device. The communication method provided in this embodiment of the present application may further include: when the terminal device determines that the access network device needs to stop providing time to the terminal device, sending second indication information to the first network element. The second indication information indicates that the terminal device requests to stop providing time. The terminal device receives fourth indication information from the first network element. The fourth indication information indicates that the first network element has stopped providing time to the terminal device. In this way, after receiving the quality information of the first clock, the terminal device can determine to change the first clock based on the quality information of the first clock. If the first clock is not as good as the clock locally deployed on the terminal device, the terminal device can send a time provision stop indication to the access network device to timely notify the network that the network no longer needs to provide time to the terminal device.

[0030] In a possible design solution, receiving, by the terminal device, the quality information of the first clock from the first network element may include receiving, by the terminal device, a radio resource control (RRC) message from the first network element, wherein the RRC message includes the quality information of the first clock.

[0031] In another possible design solution, receiving the quality information of the first clock from the first network element by the terminal device includes receiving a system message from the first network element by the terminal device, the system message including the quality information of the first clock.

[0032] In a possible design solution, the first network element is a mobility management network element. The communication method provided in this embodiment of the present application may further include, when the terminal device determines that the access network device needs to stop providing time to the terminal device, sending second indication information to the first network element. The second indication information indicates that the terminal device requests to stop providing time.

[0033] In a possible design solution, the first network element is a mobility management network element. The communication method provided in this embodiment of the present application may further include, when the terminal device determines that the access network device needs to stop providing time to the terminal device, sending second indication information to the time synchronization network element. The second indication information indicates that the terminal device requests to stop providing time.

[0034] In a possible design solution, receiving, by the terminal device, the quality information of the first clock from the first network element may include receiving, by the terminal device, a non-access stratum NAS message from the first network element, wherein the NAS message includes the quality information of the first clock.

[0035] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0036] For the technical effects of the communication method according to the third aspect, please refer to the technical effects of the communication method according to the first aspect, and the details will not be described again in this specification.

[0037] According to a fourth aspect, a communication method is provided. The method may be executed by a time synchronization network element, or may be executed by a component of the time synchronization network element, such as a processor, chip, or chip system of the time synchronization network element, or may be implemented by a logic module or software capable of realizing all or part of the functions of the time synchronization network element. The following describes an example in which the method is executed by the time synchronization network element. The communication method includes the time synchronization network element receiving fifth indication information from an application network element. The fifth indication information indicates that the wireless communication network will provide quality information of a first clock to the terminal device, where the first clock is a reference clock of the wireless communication system. The time synchronization network element obtains the quality information of the first clock based on the fifth indication information. The time synchronization network element transmits the quality information of the first clock to the terminal device.

[0038] According to the communication method, the time synchronization network element may trigger acquisition of quality information of the first clock based on the fifth indication information sent by the application network element to provide the quality information of the first clock to the terminal device. After acquiring the quality information of the first clock, for example, the terminal device may compare the first clock with another available clock based on the quality information of the first clock to select a better and more accurate clock as the grandmaster.

[0039] In a possible design solution, the time synchronization network element obtaining the quality information of the first clock based on the fifth indication information may include the time synchronization network element sending a third message to the user plane network element based on the fifth indication information, the third message being used to request the quality information of the first clock, and the time synchronization network element receiving the quality information of the first clock from the user plane network element.

[0040] In another possible design solution, the time synchronization network element obtaining the quality information of the first clock based on the fifth instruction information may include the time synchronization network element sending a fourth message to the operation, management, and maintenance network element based on the fifth instruction information, the fourth message being used to request the quality information of the first clock, and the time synchronization network element receiving the quality information of the first clock from the operation, management, and maintenance network element.

[0041] In a possible design solution, the communication method provided in this embodiment of the present application may further include the time synchronization network element receiving first indication information from the application network element before the time synchronization network element receives the fifth indication information from the application network element. The first indication information indicates acquiring quality information of the first clock, and the quality information of the first clock is used by the application network element to determine whether to continue querying the time providing service for the terminal device. The time synchronization network element acquires the quality information of the first clock based on the first indication information. The time synchronization network element transmits the quality information of the first clock to the application network element. Correspondingly, the time synchronization network element acquiring the quality information of the first clock based on the fifth indication information includes the time synchronization network element locally acquiring the quality information of the first clock based on the fifth indication information.

[0042] In a possible design solution, the time synchronization network element transmitting the quality information of the first clock to the terminal device may include the time synchronization network element transmitting, to the access network device, information used to confirm whether the access network device has the quality information of the first clock. The time synchronization network element receives an acknowledgment from the access network device. The acknowledgment indicates that the access network device does not have the quality information of the first clock. The time synchronization network element transmits the quality information of the first clock to the terminal device based on the acknowledgment.

[0043] In a possible design solution, the communication method provided in this embodiment of the present application may further include the time synchronization network element receiving second instruction information from the terminal device, the second instruction information indicating that the terminal device requests to stop providing time, and the time synchronization network element sending third instruction information to the access network device, the third instruction information indicating that the access network device stops providing time to the terminal device.

[0044] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0045] According to a fifth aspect, a communication method is provided. The method may be executed by an application network element, or may be executed by a component of the application network element, such as a processor, chip, or chip system of the application network element, or may be implemented by a logic module or software capable of realizing all or part of the functions of the application network element. The following describes an example in which the method is executed by the application network element. The communication method includes the application network element sending fifth indication information to a time synchronization network element. The fifth indication information indicates that the wireless communication system will provide quality information of a first clock to the terminal device, where the first clock is a reference clock of the wireless communication system.

[0046] In a possible design solution, before the application network element sends the fifth indication information to the time synchronization network element, the method provided in this embodiment of the present application further includes the application network element sending first indication information to the time synchronization network element. The first indication information indicates obtaining quality information of the first clock. The application network element receives the quality information of the first clock from the time synchronization network element. The application network element determines, based on the quality information of the first clock, to continue querying the time providing service for the terminal device.

[0047] In a possible design solution, the communication method provided in this embodiment of the present application may further include: the application network element receiving sixth indication information from the terminal device, wherein the sixth indication information indicates that the application network element requests the terminal device to stop querying the time providing service.

[0048] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0049] For the technical effects of the communication method according to the fifth aspect, please refer to the technical effects of the communication method according to the fourth aspect, and the details will not be described again in this specification.

[0050] According to a sixth aspect, a communication method is provided. The method may be executed by a terminal device, or may be executed by a component of the terminal device, such as a processor, chip, or chip system of the terminal device, or may be implemented by a logic module or software capable of realizing all or part of the functions of the terminal device. The following describes an example in which the method is executed by the terminal device. The communication method includes the terminal device receiving quality information of a first clock from a time synchronization network element. The quality information of the first clock is used by the terminal device to determine whether the access network device needs to continue providing time to the terminal device, where the first clock is a reference clock of a wireless communication system. The terminal device determines, based on the quality information of the first clock, that the access network device needs to continue providing time to the terminal device. Alternatively, the terminal device determines, based on the quality information of the first clock, that the access network device needs to stop providing time to the terminal device.

[0051] In a possible design solution, the communication method provided in this embodiment of the present application may further include, when the terminal device determines that the access network device needs to stop providing time to the terminal device, sending second indication information to the access network device. The second indication information indicates that the terminal device requests to stop providing time. The terminal device receives fourth indication information from the access network device. The fourth indication information indicates that the access network device has stopped providing time to the terminal device.

[0052] Optionally, the fourth indication information may be carried in an RRC message.

[0053] In a possible design solution, the first network element is a mobility management network element. The communication method provided in this embodiment of the present application may further include, when the terminal device determines that the access network device needs to stop providing time to the terminal device, sending second indication information to the time synchronization network element. The second indication information indicates that the terminal device requests to stop providing time.

[0054] In a possible design solution, the first network element is a mobility management network element. The communication method provided in this embodiment of the present application may further include, when the terminal device determines that the access network device needs to stop providing time to the terminal device, sending second indication information to the mobility management network element. The second indication information indicates that the terminal device requests to stop providing time.

[0055] In a possible design solution, the communication method provided in this embodiment of the present application may further include, when the terminal device determines that the access network device needs to stop providing time to the terminal device, sending sixth indication information to the application network element, wherein the sixth indication information indicates that the application network element requests the terminal device to stop querying the time providing service.

[0056] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0057] For the technical effects of the communication method according to the sixth aspect, please refer to the technical effects of the communication method according to the fourth aspect, and the details will not be described again in this specification.

[0058] According to a seventh aspect, there is provided a communication device for performing the aforementioned method. The communication device may be the first network element of the first aspect, a device including the first network element, or a device, such as a chip, included in the first network element. The communication device includes corresponding modules, units, or means for performing the method according to the first aspect. The modules, units, or means may be implemented by hardware, software, or hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the aforementioned functions.

[0059] In some possible designs, the communications device includes a processing module and a transceiver module. The processing module is configured to determine that quality information of a first clock needs to be acquired. The first clock is a reference clock of a wireless communications system. The transceiver module is configured to send first indication information to a second network element. The first indication information indicates acquiring the quality information of the first clock. The transceiver module is configured to receive the quality information of the first clock from the second network element and send the quality information of the first clock to a terminal device.

[0060] In a possible design solution, the communications device according to a seventh aspect is a mobility management network element. Specifically, the processing module being configured to determine that quality information of the first clock needs to be acquired includes the processing module being configured to: send, to an access network device using a transceiver module, information used to confirm whether the access network device has the quality information of the first clock; receive, from the access network device using the transceiver module, an acknowledgement; and, if the acknowledgement indicates that the access network device does not have the quality information of the first clock, determine that the quality information of the first clock needs to be acquired based on the acknowledgement.

[0061] In a possible design solution, the transceiver module being further configured to transmit the quality information of the first clock to the terminal device specifically includes the transceiver module being configured to transmit a non-access stratum NAS message to the terminal device, the NAS message including the quality information of the first clock.

[0062] Furthermore, the transceiver module is further configured to receive second instruction information from the terminal device, the second instruction information indicating that the terminal device requests to stop providing time. The transceiver module is further configured to send third instruction information to the access network device, the third instruction information indicating that the access network device will stop providing time to the terminal device.

[0063] In a possible design solution, the communication device according to the seventh aspect may be an operation, administration and maintenance network element or a time synchronization network element.

[0064] In another possible design solution, the communication apparatus according to the seventh aspect is an access network device. The processing module configured to determine that quality information of the first clock needs to be acquired specifically includes the processing module configured to: receive a time-providing request from a terminal device using a transceiver module; determine whether the first network element has quality information of the first clock based on first indication information included in the time-providing request; and determine that the quality information of the first clock needs to be acquired if the processing module determines that the first network element does not have the quality information of the first clock.

[0065] Furthermore, the transceiver module is further configured to receive second indication information from the terminal device, the second indication information indicating that the terminal device requests to stop providing time. The transceiver module is further configured to send fourth indication information to the terminal device, the fourth indication information indicating that the first network element has stopped providing time to the terminal device.

[0066] Optionally, the fourth indication information may be carried in an RRC message.

[0067] In a possible design solution, the transceiver module being further configured to transmit the quality information of the first clock to the terminal device may include the transceiver module being further configured to transmit a radio resource control (RRC) message to the terminal device, wherein the RRC message may include the quality information of the first clock.

[0068] In another possible design solution, the transceiver module being further configured to transmit the quality information of the first clock to the terminal device may include the transceiver module being further configured to transmit a system message to the terminal device, wherein the system message may include the quality information of the first clock.

[0069] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0070] Optionally, the transceiver module in this embodiment of the present application may include a receiving module and a transmitting module, wherein the transmitting module is configured to realize a transmitting function of the communication device according to the seventh aspect, and the receiving module is configured to realize a receiving function of the communication device according to the seventh aspect.

[0071] Optionally, the communication device according to the seventh aspect may further include a storage module, the storage module storing a program or instruction, and when the processing module executes the program or instruction, the communication device according to the seventh aspect is enabled to perform the communication method according to the first aspect.

[0072] For the technical effects of the communication device according to the seventh aspect, please refer to the technical effects of the communication method according to the first aspect, and the details will not be described again in this specification.

[0073] According to an eighth aspect, there is provided a communication device for performing the aforementioned method. The communication device may be the second network element of the second aspect, or may be a device including the second network element, or may be a device, such as a chip, included in the second network element. The communication device includes corresponding modules, units, or means for performing the method according to the second aspect. The modules, units, or means may be implemented by hardware, software, or hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the aforementioned functions.

[0074] In some possible designs, the communications device includes a processing module and a receiving module. The transceiver module is configured to receive first indication information from a first network element. The first indication information indicates acquiring quality information of a first clock, the first clock being a reference clock of the wireless communications system. The processing module is configured to acquire the quality information of the first clock based on the first indication information. The transceiver module is further configured to transmit the quality information of the first clock to the first network element.

[0075] In a possible design solution, the communication device according to the eighth aspect may be a time synchronization network element. Specifically, the processing module configured to obtain the quality information of the first clock based on the first indication information includes the processing module configured to: send a first message to the user plane network element based on the first indication information using a transceiver module; and receive the quality information of the first clock from the user plane network element using the transceiver module. The first message is used to request the quality information of the first clock.

[0076] In another possible design solution, the communication device according to the eighth aspect may be a time-synchronization network element. Specifically, the processing module configured to obtain the quality information of the first clock based on the first instruction information includes the processing module configured to: send a second message to the operation, management, and maintenance network element based on the first instruction information using the transceiver module; and receive the quality information of the first clock from the operation, management, and maintenance network element using the transceiver module. The second message is used to request the quality information of the first clock.

[0077] Furthermore, the transceiver module is further configured to receive second instruction information from the terminal device, the second instruction information indicating that the terminal device requests to stop providing time. The transceiver module is further configured to send third instruction information to the access network device, the third instruction information indicating that the access network device will stop providing time to the terminal device.

[0078] Optionally, the communication apparatus according to the eighth aspect may be a mobility management network element or an access network device.

[0079] In a possible design solution, the first network element is a mobility management network element and the communication device according to the eighth aspect is an operation, administration and maintenance network element.

[0080] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0081] Optionally, the transceiver module in this embodiment of the present application may include a receiving module and a transmitting module, wherein the transmitting module is configured to realize a transmitting function of the communication device according to the eighth aspect, and the receiving module is configured to realize a receiving function of the communication device according to the eighth aspect.

[0082] Optionally, the communication device according to the eighth aspect may further include a storage module, the storage module storing a program or instruction, and when the processing module executes the program or instruction, the communication device according to the eighth aspect is enabled to perform the communication method according to the second aspect.

[0083] For the technical effects of the communication device according to the eighth aspect, please refer to the technical effects of the communication method according to the second aspect, and the details will not be described again in this specification.

[0084] According to a ninth aspect, there is provided a communication device for performing the aforementioned method. The communication device may be the terminal device of the third aspect, a device including the terminal device, or a device, such as a chip, included in the terminal device. The communication device includes corresponding modules, units, or means for performing the method according to the third aspect. The modules, units, or means may be implemented by hardware, software, or hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the aforementioned functions.

[0085] In some possible designs, a communications apparatus includes a processing module and a transceiver module. The transceiver module is configured to receive quality information of a first clock from a first network element. The first clock is a reference clock of a wireless communications system. The processing module is configured to determine, based on the quality information of the first clock, that the access network device needs to continue providing time to the terminal device. Alternatively, the processing module is configured to determine, based on the quality information of the first clock, that the access network device needs to stop providing time to the terminal device.

[0086] In a possible design solution, the first network element is an access network device. The transceiver module is further configured to send second indication information to the first network element when the processing module determines that the access network device needs to stop providing time to the terminal device. The second indication information indicates that the terminal device requests that the time be stopped. The transceiver module is further configured to receive fourth indication information from the first network element. The fourth indication information indicates that the first network element has stopped providing time to the terminal device.

[0087] In a possible design solution, the transceiver module being further configured to receive the quality information of the first clock from the first network element specifically includes the transceiver module being further configured to receive a radio resource control (RRC) message from the first network element, the RRC message including the quality information of the first clock.

[0088] In another possible design solution, the transceiver module being further configured to receive the quality information of the first clock from the first network element specifically includes the transceiver module being further configured to receive a system message from the first network element, the system message including the quality information of the first clock.

[0089] In a possible design solution, the first network element is a mobility management network element. The transceiver module is further configured to, when the processing module determines that the access network device needs to stop providing time to the terminal device, send second indication information to the first network element. The second indication information indicates that the terminal device requests to stop providing time.

[0090] In a possible design solution, the first network element is a mobility management network element. The transceiver module is further configured to, when the processing module determines that the access network device needs to stop providing time to the terminal device, send second indication information to the time synchronization network element. The second indication information indicates that the terminal device requests to stop providing time.

[0091] In a possible design solution, the transceiver module being further configured to receive the quality information of the first clock from the first network element specifically includes the transceiver module being further configured to receive a non-access stratum NAS message from the first network element, the NAS message including the quality information of the first clock.

[0092] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0093] Optionally, the transceiver module in this embodiment of the present application may include a receiving module and a transmitting module, wherein the transmitting module is configured to realize a transmitting function of the communication device according to the ninth aspect, and the receiving module is configured to realize a receiving function of the communication device according to the ninth aspect.

[0094] Optionally, the communication device according to the ninth aspect may further include a storage module, the storage module storing a program or instruction, and when the processing module executes the program or instruction, the communication device according to the ninth aspect is enabled to perform the communication method according to the third aspect.

[0095] For the technical effects of the communication device according to the ninth aspect, please refer to the technical effects of the communication method according to the third aspect, and the details will not be described again in this specification.

[0096] According to a tenth aspect, there is provided a communication device for performing the aforementioned method. The communication device may be the time synchronization network element of the fourth aspect, a device including the time synchronization network element, or a device, such as a chip, included in the time synchronization network element. The communication device includes corresponding modules, units, or means for performing the method according to the fourth aspect. The modules, units, or means may be implemented by hardware, software, or hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the aforementioned functions.

[0097] In some possible designs, the communications apparatus includes a processing module and a transceiver module. The transceiver module is configured to receive fifth indication information from an application network element. The fifth indication information indicates that the wireless communications network will provide quality information of a first clock to the terminal device, the first clock being a reference clock of the wireless communications system. The processing module is configured to obtain the quality information of the first clock based on the fifth indication information. The transceiver module is further configured to transmit the quality information of the first clock to the terminal device.

[0098] In a possible design solution, the step of configuring the processing module to obtain the quality information of the first clock based on the fifth indication information specifically includes the step of: using the transceiver module to send a third message to the user plane network element based on the fifth indication information; and using the transceiver module to receive the quality information of the first clock from the user plane network element. The third message is used to request the quality information of the first clock.

[0099] In another possible design solution, the step of configuring the processing module to obtain the quality information of the first clock based on the fifth instruction information specifically includes the step of: using the transceiver module to send a fourth message to the operation, management, and maintenance network element based on the fifth instruction information; and using the transceiver module to receive the quality information of the first clock from the operation, management, and maintenance network element. The fourth message is used to request the quality information of the first clock.

[0100] In a possible design solution, the transceiver module is further configured to receive first indication information from the application network element before receiving fifth indication information from the application network element. The first indication information indicates acquiring quality information of the first clock, and the quality information of the first clock is used by the application network element to determine whether to continue querying the time providing service for the terminal device. The processing module is configured to acquire the quality information of the first clock based on the first indication information. The transceiver module is further configured to transmit the quality information of the first clock to the application network element. Correspondingly, configuring the processing module to acquire the quality information of the first clock based on the fifth indication information includes configuring the processing module to locally acquire the quality information of the first clock based on the fifth indication information.

[0101] In a possible design solution, the transceiver module being further configured to transmit the quality information of the first clock to the terminal device specifically includes the transceiver module being further configured to transmit, to the access network device, information used to confirm whether the access network device has the quality information of the first clock, and receive an acknowledgement from the access network device, where the acknowledgement indicates that the access network device does not have the quality information of the first clock. Furthermore, the transceiver module is further configured to transmit the quality information of the first clock to the terminal device based on the acknowledgement.

[0102] In a possible design solution, the transceiver module is further configured to receive second instruction information from the terminal device, the second instruction information indicating that the terminal device requests to stop providing time. The transceiver module is further configured to send third instruction information to the access network device, the third instruction information indicating that the access network device stops providing time to the terminal device.

[0103] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0104] Optionally, the transceiver module in this embodiment of the present application may include a receiving module and a transmitting module, wherein the transmitting module is configured to realize a transmitting function of the communication device according to the tenth aspect, and the receiving module is configured to realize a receiving function of the communication device according to the tenth aspect.

[0105] Optionally, the communication device according to the tenth aspect may further include a storage module, the storage module storing a program or instruction, and when the processing module executes the program or instruction, the communication device according to the tenth aspect is enabled to perform the communication method according to the fourth aspect.

[0106] For the technical effects of the communication device according to the tenth aspect, please refer to the technical effects of the communication method according to the fourth aspect, and the details will not be described again in this specification.

[0107] According to an eleventh aspect, there is provided a communication device for performing the aforementioned method. The communication device may be the application network element of the fifth aspect, a device including the application network element, or a device, such as a chip, included in the application network element. The communication device includes corresponding modules, units, or means for performing the method according to the fifth aspect. The modules, units, or means may be implemented by hardware, software, or hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the aforementioned functions.

[0108] In some possible designs, the communications apparatus includes a transceiver module configured to transmit fifth indication information to the time synchronization network element, the fifth indication information indicating that the wireless communications system will provide quality information of a first clock to the terminal device, the first clock being a reference clock of the wireless communications system.

[0109] In a possible design solution, the communication device according to the eleventh aspect further includes a processing module. The transceiver module is further configured to send first instruction information to the time synchronization network element before sending the fifth instruction information to the time synchronization network element. The first instruction information indicates obtaining quality information of the first clock. The transceiver module is further configured to receive the quality information of the first clock from the time synchronization network element. The processing module is further configured to determine whether to continue querying the time providing service for the terminal device based on the quality information of the first clock.

[0110] In a possible design solution, the transceiver module being further configured to send fifth instruction information to the time synchronization network element specifically includes the processing module being further configured to send fifth instruction information to the time synchronization network element if the processing module decides to continue to query the time providing service to the terminal device.

[0111] In a possible design solution, the transceiver module is further configured to receive sixth indication information from the terminal device, the sixth indication information indicating that the application network element requests the terminal device to stop querying the time providing service.

[0112] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0113] Optionally, the transceiver module in this embodiment of the present application may include a receiving module and a transmitting module, wherein the transmitting module is configured to realize a transmitting function of the communication device according to the eleventh aspect, and the receiving module is configured to realize a receiving function of the communication device according to the eleventh aspect.

[0114] Optionally, the communication device according to the eleventh aspect may further include a storage module, the storage module storing a program or instruction, and when the processing module executes the program or instruction, the communication device according to the eleventh aspect is enabled to perform the communication method according to the fifth aspect.

[0115] For the technical effects of the communication device according to the eleventh aspect, please refer to the technical effects of the communication method according to the fifth aspect, and the details will not be described again in this specification.

[0116] According to a twelfth aspect, there is provided a communication device for performing the aforementioned method. The communication device may be the terminal device of the sixth aspect, a device including the terminal device, or a device, such as a chip, included in the terminal device. The communication device includes corresponding modules, units, or means for performing the method according to the sixth aspect. The modules, units, or means may be implemented by hardware, software, or hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the aforementioned functions.

[0117] In some possible designs, the communications apparatus includes a processing module and a transceiver module. The transceiver module is configured to receive quality information of a first clock from a time synchronization network element. The quality information of the first clock is used by the terminal device to determine whether the access network device needs to continue providing time to the terminal device, the first clock being a reference clock of the wireless communications system. The processing module is configured to determine, based on the quality information of the first clock, that the access network device needs to continue providing time to the terminal device. Alternatively, the processing module is configured to determine, based on the quality information of the first clock, that the access network device needs to stop providing time to the terminal device.

[0118] In a possible design solution, the transceiver module is further configured to send second indication information to the access network device when the processing module determines that the access network device needs to stop providing time to the terminal device. The second indication information indicates that the terminal device requests that the time be stopped. The transceiver module is further configured to receive fourth indication information from the access network device. The fourth indication information indicates that the access network device has stopped providing time to the terminal device.

[0119] Optionally, the fourth indication information may be carried in an RRC message.

[0120] In a possible design solution, the first network element is a mobility management network element. The transceiver module is further configured to, when the processing module determines that the access network device needs to stop providing time to the terminal device, send second indication information to the mobility management network element. The second indication information indicates that the terminal device requests to stop providing time.

[0121] In a possible design solution, the transceiver module is further configured to, when the processing module determines that the access network device needs to stop providing time to the terminal device, send sixth indication information to the application network element, wherein the sixth indication information indicates that the application network element requests the terminal device to stop querying the time providing service.

[0122] Optionally, the quality information of the first clock may include one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time UTC traceability.

[0123] Optionally, the transceiver module may include a receiving module and a transmitting module, the transmitting module configured to implement a transmitting function of the communication device according to the twelfth aspect, and the receiving module configured to implement a receiving function of the communication device according to the twelfth aspect.

[0124] Optionally, the communication device according to the twelfth aspect may further include a storage module, the storage module storing a program or instruction, and when the processing module executes the program or instruction, the communication device according to the twelfth aspect is enabled to perform the communication method according to the sixth aspect.

[0125] For the technical effects of the communication device according to the twelfth aspect, please refer to the technical effects of the communication method according to the fifth aspect, and the details will not be described again in this specification.

[0126] According to a thirteenth aspect, there is provided a communication device, the communication device including a processor, coupled to a memory, configured to execute a computer program stored in the memory to enable the communication device to perform a method according to any one of the possible implementations described in the first to sixth aspects.

[0127] In a possible design solution, the communication device according to the thirteenth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used by the communication device according to the thirteenth aspect to communicate with other communication devices.

[0128] In this embodiment of the present application, the communication apparatus according to the thirteenth aspect may be the first network element of the first aspect, the second network element of the second aspect, the terminal device of the third aspect, the time synchronization network element of the fourth aspect, the application network element of the fifth aspect, or the terminal device of the sixth aspect, or may be a chip (system) or another component or assembly that may be disposed in the first network element, the second network element, the terminal device, the time synchronization network element, or the application network element, or may be an apparatus including the first network element, the second network element, the terminal device, the time synchronization network element, or the application network element.

[0129] For the technical effects of the thirteenth aspect, please refer to the technical effects of the method according to any one of the implementation forms described in the first to sixth aspects, and the details will not be described again in this specification.

[0130] According to a fourteenth aspect, there is provided a communication system including a first network element, a second network element, and a terminal device, wherein the first network element is configured to perform the communication method according to the first aspect, the second network element is configured to perform the communication method according to the second aspect, and the terminal device is configured to perform the communication method according to the third aspect.

[0131] According to a fifteenth aspect, there is provided a communication system including a time synchronization network element, an application network element, and a terminal device, wherein the time synchronization network element is configured to perform the communication method according to the fourth aspect, the application network element is configured to perform the communication method according to the fifth aspect, and the terminal device is configured to perform the communication method according to the sixth aspect.

[0132] According to a sixteenth aspect, there is provided a computer-readable storage medium, which stores a computer program or instructions, which, when executed on a computer, enables the computer to perform a method according to any one of the possible implementations described in the first to sixth aspects.

[0133] According to a seventeenth aspect, there is provided a computer program product, the computer program product comprising a computer program or instructions, which, when executed on a computer, enable the computer to perform a method according to any one of the possible implementations described in the first to sixth aspects. [Brief explanation of the drawings]

[0134] [Figure 1] 1 is a diagram of the architecture of a communication system according to an embodiment of the present application; [Figure 2] FIG. 2 is a diagram of another communication system architecture according to an embodiment of the present application. [Figure 3] FIG. 1 is a diagram of a 5GS architecture according to an embodiment of the present application. [Figure 4] 1 is a schematic flowchart of a communication method according to an embodiment of the present application; [Figure 5] 4 is a schematic flowchart of another communication method according to an embodiment of the present application; [Figure 6] 4 is a schematic flowchart of yet another communication method according to an embodiment of the present application; [Figure 7] 4 is a schematic flowchart of yet another communication method according to an embodiment of the present application; [Figure 8] 4 is a schematic flowchart of yet another communication method according to an embodiment of the present application; [Figure 9] 1 is a diagram of the structure of a communication device according to an embodiment of the present application; [Figure 10] FIG. 10 is a diagram of the structure of another communication device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0135] For ease of understanding, the following first describes the related art in the embodiments of the present application.

[0136] Network elements in a 5G system are time-synchronized, and the clock for synchronization is called a 5G clock. The 5GS clock, a 5G network capability, can be exposed to external networks to release the clock and provide the time synchronization function, i.e., the time provisioning capability of the 5G network, based on the external network's requirements. However, the time provisioning capability exposure specified in R17 may be enabled and disabled by the AF to provide time to terminal devices. When providing time to terminal devices, time synchronization is first performed on the clock information of the access network device and the 5GS grandmaster (GM). Then, the access network device transmits the clock information to terminal devices within its coverage area to complete the time provisioning for the terminal devices.

[0137] In the process in which the AF requests the 5G network to provide clock information to the terminal device, the core network device can provide the time to the terminal device by referring to the clock subscription data of the terminal device, or can provide the time to the terminal device without referring to the clock subscription data of the terminal device.

[0138] However, in the above-mentioned time provision process, the terminal device can only obtain 5GS clock information synchronized by the access network device and cannot determine changes to the 5GS clock information. In this case, the terminal device cannot compare the 5GS clock with other available clocks, and as a result, cannot select the most suitable and accurate clock as the grandmaster. Therefore, an embodiment of the present application provides a communication method to solve the problem that the terminal device cannot determine changes to the 5GS clock information.

[0139] The technical solutions of the present application are described below with reference to the accompanying drawings.

[0140] The technical solutions in the embodiments of the present application can be applied to various communication systems, such as wireless fidelity (WiFi) systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, vehicular Internet communication systems, fourth-generation (4G) mobile communication systems, such as long-term evolution (LTE) systems and worldwide interoperability for microwave access (WiMAX) communication systems, fifth-generation (5G) mobile communication systems, such as new radio (NR) systems, and future communication systems, such as sixth-generation (6G) mobile communication systems.

[0141] All aspects, embodiments, or features are presented in this application by describing systems that may include multiple devices, components, modules, etc. It is to be appreciated and understood that each system may include other devices, components, modules, etc. and / or may not include all of the devices, components, modules, etc. discussed with reference to the accompanying drawings. Additionally, combinations of these may also be used.

[0142] Furthermore, in the embodiments of the present application, terms such as "example" and "for example" are used to denote serving as an example, an illustration, or an illustration. Any embodiment or design solution described as an "example" in the present application should not be described as preferred or having more advantages than another embodiment or design solution. Rather, the term "example" is used to present a concept in a particular way.

[0143] In the embodiments of the present application, the terms "information," "signal," "message," "channel," and "signaling" may be used interchangeably. It should be noted that the meanings expressed by the terms are consistent when the differences between the terms are not emphasized. The terms "of," "relevant," and "corresponding" may be used interchangeably. It should be noted that the meanings expressed by the terms are consistent when the differences between the terms are not emphasized.

[0144] The network architectures and service scenarios described in the embodiments of the present application are intended to more clearly explain the technical solutions of the embodiments of the present application, and do not constitute limitations on the technical solutions provided in the embodiments of the present application. As those skilled in the art can see, with the evolution of network architectures and the emergence of new service scenarios, the technical solutions provided in the embodiments of the present application can also be applied to similar technical problems.

[0145] In order to facilitate the understanding of the embodiments of the present application, the communication system shown in Figure 1 is first used as an example to describe in detail the communication system to which the embodiments of the present application can be applied. For example, Figure 1 is an architecture diagram of a communication system to which the communication method according to one embodiment of the present application can be applied.

[0146] As shown in Figure 1, the communication system includes a first network element, a second network element, and a terminal device, where the first network element, the second network element, and the terminal device may communicate with each other directly or via transmission by another device.

[0147] In a possible implementation, the first network element determines that quality information of a first clock needs to be acquired and sends first indication information to a second network element. The first clock is a reference clock of a wireless communication system, and the first indication information indicates that the quality information of the first clock should be acquired. The second network element receives the first indication information from the first network element, acquires the quality information of the first clock based on the first indication information, and sends the quality information of the first clock to the terminal device. The terminal device then receives the quality information of the first clock from the first network element and determines whether the access network device needs to continue providing time to the terminal device based on the quality information of the first clock. For a specific implementation process of the solution, please refer to the relevant description of the method embodiment below. Details will not be described in this specification.

[0148] In this embodiment of the present application, the first network element may be a mobility management network element or may be an access network device shown in Figure 1, which is not limited in this embodiment of the present application.

[0149] When the first network element is a mobility management network element, the second network element may be a time synchronization network element or an operation, management, and maintenance network element. In other words, when the first network element is a mobility management network element, the communication system shown in FIG. 1 may include a mobility management network element, a time synchronization network element, and a terminal device. Alternatively, the communication system shown in FIG. 1 may include a mobility management network element, an operation, management, and maintenance network element, and a terminal device. In addition, the operation, management, and maintenance network element in this embodiment of the present application may be a network management system of the communication system. This is not specifically limited in this embodiment of the present application.

[0150] When the first network element is an access network element, the second network element may be a time-synchronization network element. In other words, when the first network element is a mobility management network element, the communication system shown in Figure 1 includes a time-synchronization network element, an access network element, and a terminal device.

[0151] For example, Figure 2 is a diagram of another communication system architecture according to an embodiment of the present application. The communication system includes a time synchronization network element, an application network element, and a terminal device. The time synchronization network element, the application network element, and the terminal device can communicate with each other directly or through transfer by another device.

[0152] In a possible implementation, the application network element sends fifth indication information to the time synchronization network element. The fifth indication information indicates that the wireless communication system will provide quality information of a first clock to the terminal device, where the first clock is a reference clock of the wireless communication system. The time synchronization network element receives the fifth indication information from the application network element, obtains the quality information of the first clock based on the fifth indication information, and then sends the quality information of the first clock to the terminal device. The terminal device receives the quality information of the first clock from the time synchronization network element and determines whether the access network device needs to continue providing time to the terminal device based on the quality information of the first clock. For a specific implementation process of the solution, please refer to the relevant description of the method embodiment below. Details will not be described in this specification.

[0153] Although not shown, the communication system shown in Figure 1 and / or Figure 2 may further include other network elements or devices, such as a user plane network element and a network exposure network element, which are not specifically limited in this embodiment of the present application.

[0154] The mobility management network element in this embodiment of the present application is mainly configured for terminal device attachment, mobility management, and tracking area update procedures in a mobile network. The mobility management network element terminates non-access stratum (NAS) messages, completes registration management, connection management, reachability management, tracking area list (TA) allocation, mobility management, etc., and transparently routes session management (SM) messages to the session management network element. In a 5G communication system, the mobility management network element may be an AMF network element. In future communication systems such as a 6G communication system, the mobility management network element may remain an AMF network element or have another name. This is not limited in this embodiment of the present application.

[0155] The time synchronization network element in this embodiment of the present application is mainly configured to support time synchronization functions. The time synchronization network element determines and manages precision time protocol (PTP) functions supported by a device-side time sensitive network translator (DS-TT) and a network-side time sensitive network translator (NW-TT) by exchanging port management information and user plane node management information. In a 5G communication system, the time synchronization network element may be a TSCTSF network element. In future communication systems, such as a 6G communication system, the time synchronization network element may remain a TSCTSF network element or have another name. This is not limited in this embodiment of the present application.

[0156] The application network element in this embodiment of the present application is a functional network element that can provide various business services. The application network element may be a third-party application control platform or a carrier's device. The application network element can provide services to multiple application servers, interact with the core network directly or through a network exposure functional network element, and interact with a policy management framework to perform policy management. In a 5G communication system, the application network element may be an AF network element. In future communication systems, such as a 6G communication system, the application network element may remain an AF network element or may have a different name. This is not limited in this embodiment of the present application.

[0157] In this embodiment of the present application, the access network device is disposed on the network side of a communication system and is a device having a wireless transceiver function, or a chip or chip system that can be disposed within the device. The network device includes, but is not limited to, an access point (AP) in a wireless fidelity (WiFi) system, such as a home gateway, a router, a server, a switch, or a bridge, an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., home evolved Node B or home Node B, HNB), a baseband unit (BBU), a wireless relay node, a wireless backhaul node, a transmission and reception point (TRP, or transmission point, TP), etc. The network device may alternatively be a gNB or transmission point (TRP or TP) of a 5G system, for example, a new radio (NR) system, or one antenna panel or a group of antenna panels (including multiple antenna panels) of a base station of a 5G system. The network device may alternatively be a network node constituting a gNB or transmission point, for example, a baseband unit (BBU) or a distributed unit (DU), or a road side unit (RSU) having base station functionality.

[0158] In this embodiment of the present application, the terminal device is a terminal that accesses a communication system and has a wireless transceiver function, or the terminal device is a chip or chip system that can be disposed in a terminal. The terminal device may also be called user equipment (UE), user equipment, access terminal, subscriber unit, subscriber station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user equipment. The terminal device in this embodiment of the present application may be a mobile phone, a tablet, a computer with a wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, an in-vehicle terminal, an RSU with a terminal function, etc. The terminal device of the present application may alternatively be an on-board module, on-board assembly, on-board component, on-board chip, or on-board unit that is incorporated into the vehicle as one or more components or units. The vehicle can perform the communication method of the present application by using the on-board module, on-board assembly, on-board component, on-board chip, or on-board unit that is incorporated into the vehicle.

[0159] It should be noted that the communication system provided in this embodiment of the present application can be applied to various communication systems mentioned above. A 5G communication system is used as an example. A network element or entity corresponding to a mobility management network element may be an AMF network element in a 5G mobile communication system, a network element or entity corresponding to a time synchronization network element may be a TSCTSF network element in a 5G mobile communication system, and a network element or entity corresponding to an application network element may be an AF network element in a 5G mobile communication system. This is not specifically limited in this embodiment of the present application.

[0160] For example, Figure 3 is a diagram of a 5GS architecture according to an embodiment of the present application. As shown in Figure 3, the communication system includes a UE, an access network (AN), and a core network (CN).

[0161] The AN is configured to realize access-related functions, can provide network access functions to authorized users within a specific area, and can determine transmission links of different qualities based on user levels, service requirements, etc. to transmit user data. The AN transfers control signals and user data between the UE and the CN. The AN may include an access network device, which is also called a radio access network (RAN) device. The CN is responsible for maintaining mobile network subscription data and provides session management, mobility management, policy management, security authentication, and other functions to the UE. The CN mainly includes the following network elements: AMF, PCF, UDM, TSCTSF, NEF, and AF.

[0162] As shown in Figure 3, the UE communicates with the AMF via the next generation network (N1) interface (abbreviated as N1). The RAN communicates with the AMF via the N2 interface (abbreviated as N2). The RAN communicates with the user plane function (UPF) via the N3 interface (abbreviated as N3). The UPF communicates with the session management function (SMF) via the N4 interface (abbreviated as N4). The UPF communicates with the data network (DN) via the N6 interface (abbreviated as N6). The UPF communicates with the UPF via the N9 interface (abbreviated as N9).

[0163] Although not shown in Figure 3, it will be understood that AMF network elements can communicate with SMF network elements via an N11 interface (abbreviated as N11). AMF network elements communicate with PCF network elements via an N15 interface (abbreviated as N15). SMF network elements communicate with PCF network elements via an N7 interface (abbreviated as N7).

[0164] Additionally, it should be noted that network elements such as the AF, AMF, SMF, policy control function (PCF), unified data management (UDM), unified data repository (UDR), and TSCTSF shown in FIG. 3 may alternatively interact with each other via service-oriented interfaces. For example, the external service-oriented interface provided by the AF may be Naf. The external service-oriented interface provided by the AMF may be Namf. The external service-oriented interface provided by the SMF may be Nsmf. The external service-oriented interface provided by the PCF may be Npcf. The external service-oriented interface provided by the UDM may be Nudm. The external service-oriented interface provided by the UDR may be Nudr. The external service-oriented interface provided by the TSCTSF may be Ntsctsf.

[0165] It should be noted that the solutions in the embodiments of the present application may also be applied to another communication system, and the corresponding names may also be replaced with the names of corresponding functions in another communication system.

[0166] It should be understood that Figures 1 and 2 are merely simplified diagrams for ease of understanding, and the communication system may further include other network devices and / or other terminal devices not shown in Figures 1 and 2.

[0167] Hereinafter, the communication method provided in the embodiment of the present application will be described in detail with reference to FIGS.

[0168] For example, Figure 4 is a schematic flowchart of a communication method according to an embodiment of the present application. The communication method is applicable to communication between a first network element, a second network element, and a terminal device in the communication system shown in Figure 1. The first network element may be an access network device or a mobility management network element, and the second network element may be a time synchronization network element or an operation, management, and maintenance network element.

[0169] As shown in FIG. 4, the communication method may include the following steps.

[0170] S401: A first network element determines that quality information of a first clock needs to be obtained.

[0171] The first clock is a reference clock for the wireless communication system.

[0172] In a possible design solution, the first network element is a mobility management network element, which may be, for example, the AMF in the above-mentioned Figure 3. In this scenario, S401 may include the following steps 1-1 to 1-3.

[0173] Step 1-1: A first network element sends information to an access network device, the information being used to determine whether the access network device has quality information of a first clock, to the access network device, and the information being used to determine whether the access network device has quality information of the first clock is used to determine whether the quality information of the first clock is deployed on the access network device.

[0174] Step 1-2: The first network element receives an acknowledgement from the access network device, which indicates that the access network device does not have quality information of the first clock.

[0175] Step 1-3: The first network element determines, based on the acknowledgement, that the quality information of the first clock needs to be obtained.

[0176] It will be understood that when the confirmation response indicates that the access network device has quality information of the first clock, the first network element can directly indicate that the access network device should send the quality information of the first clock to the terminal device, and the first network element does not need to obtain the quality information of the first clock.

[0177] For the specific implementation process of the above steps 1-1 to 1-3, please refer to the related descriptions of S505 and S506 below, and the details will not be described in this specification.

[0178] In another possible design solution, the second network element is an access network device, which may be, for example, the RAN in the above-mentioned Figure 3. In this scenario, S401 may include the following steps 2-1 to 2-3.

[0179] Step 2-1: A first network element receives a request to provide time from a terminal device.

[0180] The time provision request is used to request an access network device to provide time to a terminal device. The time provision request may include an identifier of the terminal device, time synchronization service parameters, and first indication information. The time synchronization service parameters indicate the time provision requirements of the terminal device, and the first indication information indicates obtaining quality information of the first clock.

[0181] Step 2-2: The first network element determines, based on the first indication information, whether the first network element has quality information of the first clock.

[0182] For example, after receiving a time provision request, the first network element can provide information of the first clock to the terminal device based on the time synchronization service parameters in the time provision request, and can check whether quality information of the first clock is locally deployed on the first network element based on the first indication information.

[0183] Step 2-3: If the first network element determines that it does not have the quality information of the first clock, the first network element determines that the quality information of the first clock needs to be obtained.

[0184] For example, the first network element determines that the quality information of the first clock is not locally deployed on the first network element, and thus the first network element needs to request the quality information of the first clock from the second network element.

[0185] For the specific implementation process of the above steps 2-1 to 2-3, please refer to the relevant description of S602 below, and the details will not be described in this specification.

[0186] S402: The first network element sends first indication information to the second network element, and in response, the second network element receives the first indication information from the first network element.

[0187] The first instruction information indicates that quality information of the first clock is to be acquired.

[0188] In a possible design solution, the second network element may be a time synchronization network element, which may be, for example, the TSCTSF in Figure 3. In other words, regardless of whether the first network element is an access network device or a mobility management network element, the first network element may request to obtain the quality information of the first clock from the time synchronization network element. It will be understood that the access network device may forward the first indication information to the time synchronization network element via the mobility management network element.

[0189] In addition, if the first network element is a mobility management network element, the second network element may alternatively be an operation, administration and maintenance network element, which may be, for example, an OAM.

[0190] S403: The second network element obtains quality information of the first clock based on the first indication information.

[0191] If the second network element is a time synchronization network element:

[0192] If possible, the second network element may obtain quality information of the first clock from a user plane network element, which may be, for example, the UPF in Figure 3. For example, step S403 may include the following steps 3-1 and 3-2.

[0193] Step 3-1: The second network element sends a first message to the user plane network element based on the first indication information, where the first message is used to request quality information of the first clock.

[0194] Step 3-2: The second network element receives the quality information of the first clock from the user plane network element.

[0195] In another possible case, the second network element may obtain quality information of the first clock from an operation, management, and maintenance network element. The operation, management, and maintenance network element may be, for example, an OAM. For example, S403 may include the following steps 4-1 and 4-2.

[0196] Step 4-1: The second network element sends a second message to the operation, management, and maintenance network element based on the first instruction information, where the second message is used to request quality information of the first clock.

[0197] Step 4-2: The second network element receives the quality information of the first clock from the operation, administration and maintenance network element.

[0198] In yet another possible case, if the quality information of the first clock is deployed on a second network element, the second network element may locally obtain the quality information of the first clock.

[0199] For example, if the second network element is an operation, management, and maintenance network element, the quality information of the first clock is locally deployed on the operation, management, and maintenance network element, and then, after receiving the first indication information, the operation, management, and maintenance network element can directly feed back the quality information of the first clock to the first network element.

[0200] For the specific implementation process of S403, please refer to the related descriptions of S508 and S604 below, and details will not be described in this specification.

[0201] S404: The second network element sends the quality information of the first clock to the first network element, and in response, the first network element receives the quality information of the first clock from the second network element.

[0202] It will be understood that if the first network element is an access network device, the second network element can forward the quality information of the first clock to the access network device via the mobility management network element.

[0203] S405: The first network element sends the quality information of the first clock to the terminal device, and in response, the terminal device receives the quality information of the first clock from the first network element.

[0204] If the first network element is a mobility management network element, the first network element can send a NAS message to the terminal device. The NAS message can include the quality information of the first clock. Alternatively, the first network element can first send the quality information of the first clock to the access network device, and then the access network device forwards the quality information of the first clock to the terminal device.

[0205] When the first network element is an access network device, the first network element may send an RRC message or a SIB message to the terminal device, The RRC message or the SIB message includes the quality information of the first clock.

[0206] For the specific implementation process of S405, please refer to the related descriptions of S509 to S511 and S605 to S607 below, and details will not be described in this specification.

[0207] Then, after receiving the quality information of the first clock, the terminal device can also determine, based on the quality information of the first clock, whether the access network device needs to continue providing time to the terminal device.

[0208] If the end device determines that the access network device should stop providing time to the end device:

[0209] In a possible design solution, the terminal device sends second indication information to the access network device. The second indication information indicates that the terminal device requests to stop providing time. Then, the terminal device receives fourth indication information from the access network device. The fourth indication information indicates that the access network device has stopped providing time to the terminal device.

[0210] In another possible design solution, the terminal device can send second indication information to the mobility management network element, and the mobility management network element indicates that the access network device will stop providing the time to the terminal device. In this way, the terminal device receives fourth indication information from the access network device, and the fourth indication information notifies the terminal device that the access network device will no longer provide information of the first clock to the terminal device. In this case, the mobility management network element has the ability to decide to stop providing the time.

[0211] In this case, it will be appreciated that the second indication information may be forwarded by the access network device to the mobility management network element.

[0212] In yet another possible design solution, the terminal device can send second indication information to the time synchronization network element, and the time synchronization network element indicates that the access network device will stop providing time to the terminal device. In this way, the terminal device receives fourth indication information from the access network device, and the fourth indication information notifies the terminal device that the access network device will no longer provide information of the first clock to the terminal device. In this case, the time synchronization network element also has the ability to decide to stop providing time. It will be understood that in this case, the second indication information can be sequentially forwarded to the time synchronization network element by the access network device and the mobility management network element.

[0213] For the process by which the terminal device decides to stop providing the time, please refer to the relevant description of S512 to S518 below, and the details will not be described in this specification.

[0214] In the process of providing time to a terminal device based on the communication method shown in Figure 4, the first network element can use the first instruction information to trigger the second network element to obtain quality information of the first clock, so that the first network element can obtain the quality information of the first clock from the second network element and provide the quality information of the first clock to the terminal device. Then, after obtaining the quality information of the first clock, for example, the terminal device can compare the first clock with another available clock based on the quality information of the first clock to select a better and more accurate clock as a grandmaster.

[0215] For ease of understanding, the following will describe in detail the specific implementation process of the communication method shown in Figure 4 with reference to 5GS and different scenarios.

[0216] For example, an example in which the communication method provided in this embodiment of the present application is applied to the 5GS architecture shown in Figure 3, the terminal device is a UE, the access network device is a RAN, the mobility management network element is an AMF, and the time synchronization network element is a TSCTSF is used to describe the communication method provided in this embodiment of the present application in detail. The first clock is a reference clock in 5GS, and the quality information of the first clock is 5GS clock quality information.

[0217] For example, Figure 5 is a schematic flowchart of another communication method according to an embodiment of the present application. The communication method may be performed during UE registration, and the AMF initiates a time provision request to the UE. In this scenario, the first network element is the AMF and the second network element is the TSCTSF.

[0218] As shown in FIG. 5, the communication method may include the following steps.

[0219] S501: The UE performs an attach procedure.

[0220] The attach procedure may be performed between the UE, the RAN, the AMF, and the UDM. The attach procedure may include UE random access (RRC connection setup), registration and authentication procedures, etc. For the specific process of S501, please refer to the existing implementation process. The details will not be described again in this specification.

[0221] S502: The AMF sends a first clock subscription data request to the UDM. In response, the UDM receives the first clock subscription data request from the AMF.

[0222] The first clock subscription data request (Nudm_SDM_Get_Req) ​​carries a UE identifier and is used to request acquisition of the UE's clock subscription data. The UE's clock subscription data may include one or more of the following: a time synchronization type supported by the UE, a time synchronization error tolerated by the UE, or a clock accuracy tolerated by the UE. The time synchronization type may be access stratum time synchronization and / or generalized precision time protocol (gPTP) time synchronization. The time synchronization error may be a requirement for the time synchronization error budget (sometimes referred to as time provisioning error for short) during time provisioning, where the error budget indicates the maximum error of time synchronization in the core network-RAN-UE time provisioning process. For example, the UE supports an access stratum time synchronization time provisioning service with a clock accuracy of 0.01 s and a time provisioning error not exceeding 0.05 s.

[0223] For example, during configuration of an attach procedure, the AMF may send a first clock subscription data request to the UDM to obtain clock subscription data for the UE to trigger time provision to the UE.

[0224] S503: The UDM sends a first clock subscription data response to the AMF. In response, the AMF receives a first clock subscription data response from the UDM.

[0225] The first clock subscription data response (Nudm_SDM_Get_Resp) carries the clock subscription data of the UE.

[0226] For example, the UDM may inquire about the UE's clock subscription data based on the UE's identifier in the received first clock subscription data request, and feed back the UE's clock subscription data to the AMF.

[0227] S504: The AMF sends a subscription message for clock subscription data to the UDM. In response, the UDM receives a subscription message for clock subscription data from the AMF.

[0228] The clock subscription data subscription message (Nudm_SDM_Subscribe) is used to deliver and view UE clock subscription data update notifications. In other words, when the UE's clock subscription data changes, the UDM sends updated clock subscription data to the AMF based on the AMF's subscription requirements.

[0229] It should be understood that S504 is an optional step. For example, instead of subscribing to clock subscription data update notifications from the UDM, the AMF can use the aforementioned S502 and S503 to obtain updated clock subscription data for the UE.

[0230] S505: The AMF sends a first UE context modification request to the RAN. In response, the RAN receives the first UE context modification request from the AMF.

[0231] The first UE context modification request (UE Context Modification req) carries information used to determine whether the RAN has 5GS clock quality information, a time provisioning instruction, and requirements for providing time to the UE. The time provisioning instruction is used to activate the RAN's time provisioning capability, and the requirements for providing time to the UE may include the RAN air interface time provisioning error (Uu error budget), time provisioning time synchronization type, time provisioning clock accuracy, etc.

[0232] For example, after receiving the UE's clock subscription data, the AMF can trigger the RAN to provide time to the UE. For example, the AMF can obtain the Uu error budget by calculation based on the time synchronization error (i.e., error budget) allowed by the UE in the UE's clock subscription data, determine the RAN that will provide time to the UE, and then send a UE context change request, a time provision indication, the Uu error budget, and information used to determine whether the RAN has 5GS clock quality information to the RAN. When the AMF activates the RAN's time provision capability and indicates that the RAN will provide time to the UE with an error that does not exceed the Uu error budget, the AMF can check with the RAN whether 5GS clock quality information is deployed on the RAN.

[0233] S506: The RAN sends a first UE context modification response to the AMF. In response, the AMF receives a first UE context modification response from the RAN.

[0234] In a possible design solution, if the 5GS clock quality information is locally deployed on the RAN, the first UE context modification response indicates that the RAN has the 5GS clock quality information, and the following steps S507 to S509 do not need to be performed. Instead, the AMF can indicate that the RAN provides the UE with the 5GS clock quality information.

[0235] In another possible design solution, if the 5GS clock quality information is not locally deployed on the RAN, the first UE context modification response may indicate that the RAN does not have 5GS clock quality information, and the following S507 to S509 may be further executed.

[0236] S507: The AMF sends a first 5GS clock quality information request to the TSCTSF. In response, the TSCTSF receives the first 5GS clock quality information request from the AMF.

[0237] The first 5GS clock quality information request (5GS clock quality info Req) is used to request to acquire 5GS clock quality information, and the first 5GS clock quality information request carries first indication information, an AMF identifier, and / or a RAN identifier. The first indication information indicates to acquire the 5GS clock quality information.

[0238] S508: The TSCTSF acquires the 5GS clock quality information based on the first instruction information.

[0239] For example, after receiving the first 5GS clock quality information request, the TSCTSF checks whether the 5GS clock quality information is locally deployed on the TSCTSF. If the 5GS clock quality information is locally deployed on the TSCTSF, the TSCTSF feeds back the 5GS clock quality information to the AMF based on the first indication information.

[0240] In a possible design solution, if the 5GS clock quality information is not provided on the TSCTSF, the TSCTSF can obtain the 5GS clock quality information from the UPF. For example, S508 may include the following steps 5-1 and 5-2.

[0241] Step 5-1: The TSCTSF sends a second 5GS clock quality information request to the UPF.

[0242] The second 5GS clock quality information request is used to request 5GS clock quality information, and the second 5GS clock quality information request may carry an identifier of the TSCTSF and first indication information.

[0243] It will be appreciated that the TSCTSF may alternatively send the second 5GS clock quality information request to the UPF via the SMF.

[0244] Step 5-2: The TSCTSF receives a second 5GS clock quality information response from the UPF.

[0245] The second 5GS clock quality information response carries the 5GS clock quality information.

[0246] In another possible design solution, if the 5GS clock quality information is not provided on the TSCTSF, the TSCTSF can alternatively obtain the 5GS clock quality information from the OAM. For example, S508 may include the following steps 6-1 and 6-2.

[0247] Step 6-1: The TSCTSF sends a third 5GS clock quality information request to the OAM.

[0248] The third 5GS clock quality information request is used to request 5GS clock quality information, and the third 5GS clock quality information request may carry an identifier of the TSCTSF and the first indication information.

[0249] Step 6-2: The TSCTSF receives a third 5GS clock quality information response from the OAM.

[0250] The third 5GS clock quality information response carries the 5GS clock quality information.

[0251] S509: The TSCTSF sends a first 5GS clock quality information response to the AMF. In response, the AMF receives the first 5GS clock quality information response sent by the TSCTSF.

[0252] The first 5GS clock quality information response (5GS clock quality info Resp) carries the 5GS clock quality information.

[0253] It will be understood that in this embodiment of the present application, the UPF and the OAM are both core network devices or network elements where 5GS clock quality information is locally deployed.

[0254] It should be noted that if the first indication indicates that 5GS clock quality information should be acquired, only the corresponding requested 5GS clock quality parameters may be returned in the response (e.g., the first 5GS clock quality information response, the second 5GS clock quality information response, or the third 5GS clock quality information response). For example, if the quality level and accuracy of the 5GS clock are requested to be acquired, the TSCTSF, OAM, or UPF may return only the quality level and accuracy of the 5GS clock. It will be understood that all 5GS clock quality parameters configured on the OAM, UPF, or TSCTSF may be returned as an alternative in the response. In addition, if the 5GS clock quality information that the first indication indicates to be acquired is a default value, some or all of the 5GS clock quality information configured on the OAM, UPF, or TSCTSF may be returned as an alternative in the response. This is not limited to this embodiment of the present application.

[0255] It should be noted that the above steps S507 to S509 may alternatively be replaced by the AMF sending a first 5GS clock quality information request to the OAM, and the OAM feeding back the 5GS clock quality information to the AMF after receiving the first 5GS clock quality information request. In other words, the AMF can directly query the OAM to obtain the 5GS clock quality information.

[0256] S510: The AMF sends 5GS clock quality information to the RAN. In response, the RAN receives 5GS clock quality information from the AMF.

[0257] It should be understood that S510 is an optional step. For example, when the AMF transmits 5GS clock quality information to the UE using a NAS message, the AMF may not transmit the 5GS clock quality information to the RAN. In this case, the RAN may provide the UE with time but may not provide the UE with 5GS clock information.

[0258] S511: The RAN sends 5GS clock quality information to the UE, and in response, the UE receives 5GS clock quality information from the RAN.

[0259] For example, after receiving the 5GS clock quality information, the RAN can provide time to the UE together with the 5GS clock quality information. In other words, when the RAN provides the 5GS clock information to the UE, it also provides the 5GS clock quality information to the UE.

[0260] It will be appreciated that after receiving the time provision instruction sent by the AMF, the RAN can provide 5GS clock information to the UE and start providing time to the UE without waiting to obtain 5GS clock quality information, in other words, the RAN can provide 5GS clock quality information to the UE after providing time to the UE.

[0261] Then, after receiving the 5GS clock quality information, the UE can determine whether the RAN needs to continue providing time to the UE based on the 5GS clock quality information. For example, the following steps S512 to S518 are performed.

[0262] S512: The UE determines, based on the 5GS clock quality information, whether the RAN needs to continue providing time to the UE.

[0263] For example, the UE can determine whether the RAN needs to continue providing time to the UE based on the 5GS clock quality information and the clock quality information of another available clock deployed on the UE. In other words, the UE can determine whether to continue using the 5GS clock as a grandmaster based on the 5GS clock quality information.

[0264] For example, if the 5GS clock quality information includes the quality level of the 5GS clock, the UE can determine whether the quality level of the 5GS clock has been degraded and whether the changed quality level is higher than the quality level of another available clock. If the quality level of the 5GS clock is lower than the quality level of another available clock, the UE determines that the RAN does not need to continue providing time to the UE and continues to execute step S513 below. If the quality level of the 5GS clock is higher than the quality level of another available clock, the RAN continues to provide 5GS clock information to the UE.

[0265] In another example, the 5GS clock quality information includes the crystal stability of the 5GS clock. If the crystal stability of the 5GS clock is worse than that of another available clock, the UE determines that the RAN does not need to continue providing time to the UE and continues executing step S513 below. If the crystal stability of the 5GS clock is better than that of another available clock, the RAN continues to provide 5GS clock information to the UE.

[0266] S513: The UE sends a first time provision stop request to the RAN, and in response, the RAN receives the first provision stop request from the UE.

[0267] The first time provision stop request is used by the UE to request the UE to stop providing time, and the first time provision stop request carries second indication information and an identifier of the UE. The second indication information indicates that the UE requests the UE to stop providing time. The second indication information may be called a time provision stop indication, which is not limited in this embodiment of the present application.

[0268] It will be appreciated that the first time provision stop request may be an RRC message, for example, RRC_ASTI_Update_Req.

[0269] In a possible design solution, if the RAN has the ability to determine whether to stop providing the time to the UE, the RAN can directly stop providing the time to the UE based on the second instruction information, for example, can disable the ability to provide the time to the UE. Therefore, the following S518 is executed, and the following S514 to S517 are not executed.

[0270] In another possible design solution, if the RAN does not have the ability to decide whether to stop providing the time to the UE, the AMF can decide whether the RAN stops providing the time to the UE. For example, the following S514, S517, and S518 are executed, but the following S515 and S516 are not executed.

[0271] In yet another possible design solution, if the RAN does not have the ability to decide whether to stop providing the time to the UE, the TSCTSF can instead decide whether the RAN should stop providing the time to the UE. For example, the following steps S514 to S518 are executed.

[0272] S514: The RAN sends a second time provision stop request to the AMF. In response, the AMF receives a second time provision stop request from the RAN.

[0273] The second time provision stop request is used by the UE to request the UE to stop providing time, and the second time provision stop request carries second indication information and an identifier of the UE.

[0274] If the RAN does not have the ability to determine whether to stop providing time, after receiving the first request to stop providing time sent by the UE, the RAN forwards second instruction information to the AMF using a second request to stop providing time. The AMF can determine whether to stop providing time based on the second instruction information. Alternatively, the AMF can use the TSCTSF to determine whether to stop providing time. For example, the following steps S515 to S518 are performed.

[0275] S515: The AMF sends a third suspension request to the TSCTSF. In response to this, the TSCTSF receives the third suspension request from the AMF.

[0276] The third time provision stop request also carries second indication information and an identifier of the UE.

[0277] S516: The TSCTSF sends a third suspension response to the AMF. In response, the AMF receives a third suspension response from the TSCTSF.

[0278] The third time provision stop response carries third instruction information, and the third instruction information indicates that the RAN will stop providing time to the UE.

[0279] S517: The AMF sends a second time provision stop response to the RAN. In response, the AMF receives a second provision stop response from the RAN.

[0280] The second time provision stop response carries third instruction information.

[0281] S518: The RAN sends a first time provision stop response to the UE, and in response, the UE receives the first provision stop response from the RAN.

[0282] The first time provision stop response carries fourth indication information, and the fourth indication information indicates that the RAN has stopped providing time to the UE.

[0283] It should be noted that the UE obtains the 5GS clock quality information based on the above-described steps S501 to S511. The 5GS clock quality information may be used not only for the clock comparison performed in the above-described steps S512 to S518, but also for determining whether the state of the 5GS clock changes. Alternatively, the 5GS clock quality information may be used to provide the 5GS clock quality information during time provision to associated devices. This is not specifically limited in this embodiment of the present application.

[0284] Based on the communication method shown in Figure 5, during the UE registration process, the AMF can initiate a time provision procedure to the UE, indicate that 5GS clock quality information will be obtained in the time provision procedure, and provide 5GS clock quality information to the UE.

[0285] For example, Figure 6 is a schematic flowchart of yet another communication method according to an embodiment of the present application, in which a UE can autonomously request a time-providing service. In this scenario, the first network element is a RAN and the second network element is a TSCTSF.

[0286] As shown in FIG. 6, the communication method may include the following steps.

[0287] S601: The UE sends a first access stratum clock information time provision request to the RAN, and in response, the RAN receives the first access stratum clock information time provision request from the UE.

[0288] The first access stratum clock information time provision request (RRC_ASTI_Create_Req) ​​is used to request the RAN to provide time to the UE. The first access stratum clock information time provision request may carry a UE identifier, time synchronization service parameters, and first instruction information. The time synchronization service parameters indicate the UE's requirements for the requested time provision service, and the time synchronization service parameters may include one or more of a requested time synchronization type, a requirement for clock information, and a requirement for time provision information. The time synchronization type may be access stratum time synchronization and / or gPTP time synchronization. The requirement for clock information may be a requirement for the accuracy of the clock information. The requirement for time provision information may be a requirement for a RAN air interface time provision error (Uu error budget), where the Uu error budget indicates the maximum error of time synchronization in the RAN-UE time provision process. For example, the UE requests an access stratum time synchronization time provision service with a clock information accuracy of 0.01 s and a RAN air interface time provision error not exceeding 0.05 s. The first instruction information indicates to acquire 5GS clock quality information.

[0289] If possible, after receiving the first access stratum clock information time provision request, the RAN can provide 5GS clock information to the UE based on the time provision request requested in the first access stratum clock information time provision request, and transmit the acquired 5GS clock information to the UE. In another possible case, after receiving the first access stratum clock information time provision request, the RAN does not temporarily provide 5GS clock information to the UE, but provides time to the UE after obtaining 5GS clock quality information, in other words, provides 5GS clock information to the UE. For example, after the following steps S602 to S606 are executed, the RAN provides 5GS clock information and 5GS clock quality information to the UE in S607.

[0290] S602: The RAN sends a second access stratum clock information time provision request to the AMF. In response, the AMF receives the second access stratum clock information time provision request from the RAN.

[0291] For example, after receiving the first access stratum clock information time provision request, the RAN can first check whether 5GS clock quality information is locally deployed on the RAN based on the first indication information. If 5GS clock quality information is not locally deployed on the RAN, the RAN sends a second access stratum clock information time provision request (N2 message_ASTI_Create_Req) ​​to the AMF to request acquisition of 5GS clock quality information. The second access stratum clock information time provision request carries the RAN identifier and the first indication information.

[0292] S603: The AMF sends a third access stratum clock information time provision request to the TSCTSF. In response, the TSCTSF receives the third access stratum clock information time provision request from the AMF.

[0293] For example, after receiving the second access stratum clock information time provision request, the AMF sends a third access stratum clock information time provision request (Ntsctsf_ASTI_Create_Req) ​​to the TSCTSF based on the first indication information to request the TSCTSF to obtain 5GS clock quality information. The third access stratum clock information time provision request also carries the RAN identifier and the first indication information.

[0294] S604: The TSCTSF acquires the 5GS clock quality information based on the first indication information.

[0295] For example, the TSCTSF receives a third access stratum clock information time provision request and obtains 5GS clock quality information based on the first instruction information. For the specific implementation process of S604, please refer to the relevant description of S508 above. Details will not be described again in this specification.

[0296] S605: The TSCTSF sends a third access stratum clock information time provision response to the AMF. In response, the AMF receives a third access stratum clock information time provision response from the TSCTSF.

[0297] The third access stratum clock information time provision response (Ntsctsf_ASTI_Create_Resp) carries 5GS clock quality information.

[0298] Please note that the above S603 to S605 may alternatively be replaced by the AMF sending a third access stratum clock information time provision request to the OAM, and after receiving the third access stratum clock information time provision request, the OAM feeding back 5GS clock quality information to the AMF based on the first instruction information.

[0299] S606: The AMF sends a second access stratum clock information time provision response to the RAN. In response, the RAN receives a second access stratum clock information time provision response from the AMF.

[0300] The second access stratum clock information time provision response (N2 message_ASTI_Create_Resp) carries 5GS clock quality information.

[0301] S607: The RAN sends a first access stratum clock information time provision response to the UE, and in response, the UE receives a first access stratum clock information time provision response from the RAN.

[0302] The first access stratum clock information time provision response (RRC_ASTI_Create_Resp) may carry 5GS clock quality information.

[0303] Then, after receiving the 5GS clock quality information, the UE can alternatively determine whether the RAN needs to continue providing time to the UE based on the 5GS clock quality information. For details, please refer to the relevant descriptions of S512 to S518 above. The details will not be described again in this specification.

[0304] Based on the communication method shown in Figure 6, the UE can autonomously request time provisioning services. If the RAN determines that 5GS clock quality information is not locally deployed on the RAN, it requests the TSCTSF to obtain 5GS clock quality information to provide the UE with the 5GS clock quality information. Furthermore, the UE can determine whether to change the 5GS clock information based on the 5GS clock quality information. If the 5GS clock information is not as good as the UE's locally available clock information, a better clock may be selected as the grandmaster, and the 5GS does not need to continue providing time to the UE. This improves the accuracy of the UE's clock information.

[0305] 5 and 6 illustrate in detail the implementation process of the communication method shown in FIG. 4 in a UE registration scenario and a scenario in which the UE autonomously requests time provision. An embodiment of the present application further provides a communication method for providing quality information of a first clock to a terminal device.

[0306] For example, Figure 7 is a schematic flowchart of another communication method according to an embodiment of the present application. The communication method is applicable to communication between an application network element, a time synchronization network element, and a terminal device in the communication system shown in Figure 2 above. As shown in Figure 7, the communication method may include the following steps:

[0307] S701: An application network element sends first indication information to a time synchronization network element, and in response, the time synchronization network element receives the first indication information from the application network element.

[0308] The first instruction indicates acquiring quality information of a first clock, the first clock being a reference clock of the wireless communication system, and the quality information of the first clock may include one or more of a quality level, a crystal oscillator stability, an accuracy, or a UTC traceability.

[0309] For example, before querying the time providing service for the terminal device, the application network element can first send first indication information to the time synchronization network element to obtain quality information of the first clock, which is used by the application network element to determine whether to continue querying the time providing service for the terminal device.

[0310] It will be understood that the first instruction information may indicate which quality parameter information of the first clock is specifically requested. For example, the first instruction information may indicate a request to acquire the quality level and crystal oscillator stability of the first clock. The first instruction information may or may not indicate which quality parameter information of the first clock is specifically requested. In this case, the first instruction information may be considered to be used to request acquisition of all quality parameter information of the first clock. This is not limited to this embodiment of the present application.

[0311] For the specific implementation process of S701, please refer to the relevant descriptions of S801 and S802 below, and details will not be described in this specification.

[0312] S702: The time synchronization network element sends the quality information of the first clock to the application network element, and in response, the application network element receives the quality information of the first clock from the time synchronization network element.

[0313] For example, after receiving the first indication information, the time synchronization network element may first determine whether the quality information of the first clock is locally deployed on the time synchronization network element. If the time synchronization network element determines that the quality information of the first clock is locally deployed on the time synchronization network element, the time synchronization network element may provide the quality information of the first clock to the application network element based on the specific content requested by the first indication information. If the time synchronization network element determines that the quality information of the first clock is not locally deployed on the time synchronization network element, the time synchronization network element may request the quality information of the first clock from the user plane network element or the operation, management, and maintenance network element based on the first indication information. For specific implementation processes, please refer to the relevant descriptions of S508 or S604 above. Details will not be described again in this specification.

[0314] S703: The application network element determines whether to continue to query the time providing service to the terminal device based on the quality information of the first clock.

[0315] For example, after receiving quality information of a first clock fed back by a time synchronization network element, the application network element can compare the quality information of the first clock with the quality information of another available clock deployed on the application network element to determine whether the first clock is more suitable than another available clock deployed on the application network element to be used as a grandmaster for providing clock information to the terminal device, and decide whether to continue querying the time providing service to the terminal device.

[0316] In a possible design solution, if the application network element decides to continue to inquire about the time providing service to the terminal device, the following S704 may be executed.

[0317] In another possible design solution, if the application network element decides not to continue querying the time providing service to the terminal device, the following S704 does not need to be executed.

[0318] For the specific implementation process of S703, please refer to the related description of S805 below, and the details will not be described in this specification.

[0319] It should be noted that the above steps S701 to S703 are pre-determined processes before the application network element queries the time providing service for the terminal device. When querying the time providing service for the terminal device, the application network element can directly request the time providing service from the time synchronization network element, and the above steps S701 to S703 do not need to be performed. That is, the above steps S701 to S703 are optional steps.

[0320] It should be understood that after receiving the time provision service request initiated by the application network element, the time synchronization network element may indicate that the access network device synchronizes the clock information of the wireless communication system for the terminal device based on the time provision request. For the specific process, please refer to the following time provision procedure shown in Figure 8. Details will not be described in this specification.

[0321] S704: The application network element sends fifth indication information to the time synchronization network element, and in response, the time synchronization network element receives fifth indication information from the application network element.

[0322] For example, after determining to inquire about a time providing service for the terminal device, the application network element can send fifth indication information to the time synchronization network element, where the fifth indication information indicates that the wireless communication system will provide the quality information of the first clock to the terminal device, or the fifth indication information indicates that the wireless communication system will provide the quality information of the first clock to the terminal device when providing time to the terminal device.

[0323] In addition, the fifth indication information may alternatively specifically indicate which quality information of the first clock needs to be provided to the terminal device by the wireless communication system. For example, the fifth indication information may indicate that the wireless communication system provides the terminal device with the quality level and crystal oscillator stability of the first clock. Alternatively, the fifth indication information may only indicate that the wireless communication system needs to provide the terminal device with the quality information of the first clock, rather than specifically indicating which quality information of the first clock needs to be provided to the terminal device by the wireless communication system. In this case, the fifth indication information may be considered to indicate that the wireless communication system provides all the quality information of the first clock to the terminal device. This is not limited to this embodiment of the present application.

[0324] For the specific implementation process of S704, please refer to the related description of S806 below, and details will not be described in this specification.

[0325] S705: The time synchronization network element sends information used to verify whether the access network device has the quality information of the first clock to the access network device. In response, the access network device receives information used to verify whether the access network device has the quality information of the first clock from the time synchronization network element.

[0326] For example, after receiving the fifth indication information, the time synchronization network element can further send confirmation information to the access network device, which provides time to the terminal device. The confirmation information is used to confirm whether the access network device has quality information of the first clock.

[0327] S706: The access network device sends an acknowledgement to the time synchronization network element. In response, the time synchronization network element receives an acknowledgement from the access network device.

[0328] In a possible design solution, if the quality information of the first clock is deployed on the access network device, the confirmation response indicates that the access network device has the quality information of the first clock. In this case, instead of performing the following S707 and S708, the time synchronization network element can indicate that the access network device will provide the quality information of the first clock to the terminal device after confirming that the quality information of the first clock is deployed on the access network device.

[0329] In another possible design solution, if the quality information of the first clock is not deployed on the access network device, the acknowledgement indicates that the access network device does not have the quality information of the first clock. In this case, the time synchronization network element performs the following steps S707 and S708.

[0330] It should be noted that the above steps S705 and S706 are optional steps. For example, the time synchronization network element can directly obtain and provide the quality information of the first clock to the terminal device according to the fifth indication information, without checking whether the quality information of the first clock is deployed on the access network device.

[0331] For the specific implementation process of the above S705 and S706, please refer to the related descriptions of S807 and S808 below, and details will not be described in this specification.

[0332] S707: The time synchronization network element obtains quality information of the first clock based on the fifth indication information.

[0333] In a possible design solution, if the above steps S701 to S703 are not performed, after receiving the fifth indication information, the time synchronization network element can first determine whether the quality information of the first clock is locally deployed on the time synchronization network element. If the time synchronization network element determines that the quality information of the first clock is locally deployed on the time synchronization network element, the time synchronization network element locally acquires the quality information of the first clock based on the fifth indication information. If the time synchronization network element determines that the quality information of the first clock is not locally deployed on the time synchronization network element, the time synchronization network element can request the quality information of the first clock from a user plane network element or an operation, administration, and maintenance network element.

[0334] In a possible design solution, S707 may include the following steps 7-1 and 7-2.

[0335] Step 7-1: The time synchronization network element sends a third message to the user plane network element based on the fifth indication information, where the third message is used to request quality information of the first clock.

[0336] For example, after determining that the quality information of the first clock is not deployed on the time synchronization network element, the time synchronization network element can send a third message to the user plane network element. The third message carries indication information (e.g., first indication information) used to request acquisition of the quality information of the first clock, and the indication information used to request acquisition of the quality information of the first clock indicates based on the fifth indication information. The user plane network element may be the UPF described above.

[0337] Step 7-2: The time synchronization network element receives the first clock quality information from the user plane network element.

[0338] For example, after receiving the third message, the user plane network element feeds back the quality information of the requested first clock to the time synchronization network element.

[0339] In another possible design solution, S707 may include the following steps 8-1 and 8-2.

[0340] Step 8-1: The time synchronization network element sends a fourth message to the operation, management and maintenance network element based on the fifth instruction information.

[0341] The fourth message is used to request quality information of the first clock. The operation, administration and maintenance network element may be an OAM.

[0342] Step 8-2: The time synchronization network element receives the first clock quality information from the operation, administration and maintenance network element.

[0343] In another possible design solution, when the above-mentioned S701 to S703 are executed, after receiving the fifth instruction information, the time synchronization network element can locally acquire the quality information of the first clock based on the fifth instruction information, and the quality information of the first clock is acquired in the above-mentioned S702.

[0344] For the specific implementation process of S707, please refer to the related description of S806 below, and details will not be described in this specification.

[0345] S708: The time synchronization network element sends the quality information of the first clock to the terminal device. In response, the terminal device receives the quality information of the first clock from the time synchronization network element.

[0346] For example, after obtaining the quality information of the first clock, the time synchronization network element can transmit the quality information of the first clock to the access network device via the policy control network element and the mobility management network element. The access network device then transmits the quality information of the first clock to the terminal device using an RRC message or an SIB message. Alternatively, the time synchronization network element transmits the quality information of the first clock to the mobility management network element via the policy control network element. The mobility management network element then transmits the quality information of the first clock to the terminal device using an NAS message. For specific implementation processes, please refer to the relevant descriptions of S812 to S815 below. Details will not be described in this specification. The policy control network element may be the aforementioned PCF, and the mobility management network element may be the aforementioned AMF.

[0347] Then, after receiving the quality information of the first clock, the terminal device can determine, based on the quality information of the first clock, whether the access network device needs to continue providing time to the terminal device.

[0348] For example, the terminal device may determine a change to the first clock based on the quality information of the first clock, compare the first clock with another available clock deployed on the terminal device, and determine whether the first clock can continue to be used as a grandmaster for providing clock information to the terminal device to further confirm whether the access network device needs to continue providing time to the terminal device. For example, the quality information of the first clock may include a quality level of the first clock, and the terminal device may compare the quality level of the first clock with the quality level of another available clock deployed on the terminal device. If the quality level of the first clock is higher than the quality level of another available clock deployed on the terminal device, the access network device may continue to provide time to the terminal device. If the quality level of the first clock is lower than the quality level of another available clock deployed on the terminal device, the terminal device may determine that the access network device does not need to continue providing time to the terminal device.

[0349] If the end device determines that the access network device should stop providing time to the end device:

[0350] In a possible design solution, the terminal device can send second instruction information to the access network device and receive fourth instruction information from the access network device. The second instruction information indicates that the terminal device requests to stop providing time, and the fourth instruction information indicates that the access network device has stopped providing time to the terminal device. In this case, the access network device has the ability to decide to stop providing time. After receiving the time provision stop instruction from the terminal device, the access network device can disable its ability to provide time to the terminal device and notify the terminal device that it will no longer provide information of the first clock to the terminal device.

[0351] In another possible design solution, the terminal device can send second indication information to the mobility management network element, and the mobility management network element indicates that the access network device will stop providing the time to the terminal device. In this way, the terminal device receives fourth indication information from the access network device, and the fourth indication information notifies the terminal device that the access network device will no longer provide information of the first clock to the terminal device. In this case, the mobility management network element has the ability to decide to stop providing the time.

[0352] In this case, it will be appreciated that the second indication information may be forwarded by the access network device to the mobility management network element.

[0353] In yet another possible design solution, the terminal device can send second indication information to the time synchronization network element, and the time synchronization network element indicates that the access network device will stop providing time to the terminal device. In this way, the terminal device receives fourth indication information from the access network device, and the fourth indication information notifies the terminal device that the access network device will no longer provide information of the first clock to the terminal device. In this case, the time synchronization network element also has the ability to decide to stop providing time. It will be understood that in this case, the second indication information can be sequentially forwarded to the time synchronization network element by the access network device and the mobility management network element.

[0354] In yet another possible design solution, the terminal device can alternatively send sixth indication information to the application network element via the application layer, and in response, the application network element receives sixth indication information from the terminal device, the sixth indication information indicating that the application network element should stop querying the time providing service for the terminal device.

[0355] Optionally, when sending the sixth indication information to the application network element, the terminal device may further send quality information of the current first clock to the application network element to enable the application network element to decide whether to continue to query the time provision to the terminal device.

[0356] For the process by which the terminal device decides to stop providing the time, please refer to the relevant description of S512 to S518 above, and the details will not be described again in this specification.

[0357] It will be understood that the process of the terminal device obtaining the quality information of the first clock can be implemented in the process of providing time to the terminal device. In addition, in the time providing process, if the quality information of the first clock is updated, the updated quality information of the first clock can be provided to the terminal device as an alternative using the above-mentioned S701 to S708.

[0358] It should be noted that after the terminal device acquires the quality information of the first clock, the quality information of the first clock may be used for clock comparison and not only to select a better and more accurate clock as the grandmaster, but also to determine a state change of the first clock. Alternatively, the quality information of the first clock may be used to provide the quality information of the first clock during time provision to an apparatus associated with the terminal device. This is not specifically limited in this embodiment of the present application.

[0359] According to the communication method shown in FIG. 7, the time synchronization network element can obtain quality information of the first clock based on the fifth indication information sent by the application network element and provide the quality information of the first clock to the terminal device. Then, the terminal device can determine a more accurate clock as the grandmaster based on the obtained quality information of the first clock. If the first clock is not as good as the local clock of the terminal device, the terminal device indicates in time that the wireless communication network should stop providing time to the terminal device. This can reduce network overhead.

[0360] For ease of understanding, the following describes in detail the specific implementation process of the communication method shown in Figure 7 with reference to 5GS and a specific scenario.

[0361] For example, an example in which the communication method provided in this embodiment of the present application is applied to the 5GS architecture shown in Figure 3, the terminal device is a UE, the access network device is a RAN, the mobility management network element is an AMF, the time synchronization network element is a TSCTSF, and the application network element is an AF is used to describe the communication method provided in this embodiment of the present application in detail. The first clock is a reference clock in 5GS, and the quality information of the first clock is 5GS clock quality information.

[0362] As shown in FIG. 8, the communication method may include the following steps.

[0363] S801: The AF sends a fourth 5GS clock quality information request to the NEF. In response, the NEF receives the fourth 5GS clock quality information request from the AF.

[0364] The fourth 5GS clock quality information request (5GS clock quality info Request) is used to request acquisition of 5GS clock quality information, where the 5GS clock quality information may represent a performance characteristic change of the 5GS clock. The fourth 5GS clock quality information request may carry an AF identifier and first indication information. The first indication information indicates that 5GS clock quality information is to be acquired, for example, indicating a request to acquire the quality level and accuracy of the 5GS clock.

[0365] In this embodiment of the present application, the 5GS clock quality information may include one or more of the quality level, accuracy, crystal oscillator stability, and UTC traceability of the 5GS clock.

[0366] It will be appreciated that after receiving the AF's fourth 5GS clock quality information request, the NEF may authenticate the AF based on the AF's identifier to determine whether the AF is a third party trusted by the carrier. If the AF is a third party trusted by the carrier (i.e., authentication is successful or passed), the NEF forwards the fourth 5GS clock quality information request to the TSCTSF and performs, for example, S802 below. If the AF is a third party not trusted by the carrier (i.e., authentication fails), the NEF does not accept the AF's fourth 5GS clock quality information request and cannot perform subsequent procedures.

[0367] S802: The NEF sends a fourth 5GS clock quality information request to the TSCTSF. In response, the TSCTSF receives the fourth 5GS clock quality information request from the NEF.

[0368] For example, after receiving a fourth 5GS clock quality information request from the AF, the NEF determines that the AF is a third party trusted by the carrier and forwards the fourth 5GS clock quality information request to the TSCTSF.

[0369] It will be understood that if the AF is a third party trusted by the carrier, the AF can alternatively skip the NEF and send the fourth 5GS clock quality information request directly to the TSCTSF. In other words, S801 and S802 may be replaced by the AF sending the fourth 5GS clock quality information request to the TSCTSF. In response, the TSCTSF receives the fourth 5GS clock quality information request from the AF.

[0370] S803: The TSCTSF requests to obtain 5GS clock quality information based on the fourth 5GS clock quality information request.

[0371] For example, after receiving the fourth 5GS clock quality information request, the TSCTSF can check whether the 5GS clock quality information is locally deployed on the TSCTSF based on the first indication information.

[0372] In a possible design solution, when the 5GS clock quality information is deployed on the TSCTSF, the TSCTSF transmits the 5GS clock quality information to the AF based on the first instruction information. For example, when the first instruction information indicates that the quality level and accuracy of the 5GS clock are to be acquired, the TSCTSF feeds back the quality level and accuracy of the 5GS clock to the AF.

[0373] If the 5GS clock quality information is not provided on the TSCTSF, the TSCTSF can obtain the 5GS clock quality information from the UPF or OAM based on the first indication. For specific implementation processes, please refer to the relevant descriptions of S403, S508, or S604 above. Details will not be described again in this specification.

[0374] S804: The TSCTSF sends a fourth 5GS clock quality information response to the AF. In response, the AF receives the fourth 5GS clock quality information response sent by the TSCTSF.

[0375] The fourth 5GS clock quality information response carries the 5GS clock quality information.

[0376] It should be noted that if the first indication information includes specific requested 5GS clock quality parameters, only the corresponding requested 5GS clock quality parameters may be returned in the response (e.g., the fourth 5GS clock quality information response). For example, if the quality level and accuracy of the 5GS clock are requested to be obtained, the TSCTSF, OAM, or UPF may return only the quality level and accuracy of the 5GS clock. It will be understood that all 5GS clock quality parameters configured on the OAM, UPF, or TSCTSF may be returned as an alternative in the response. In addition, if the 5GS clock quality parameters requested in the first indication information are default values, some or all of the 5GS clock quality information configured on the OAM, UPF, or TSCTSF may be returned as an alternative in the response.

[0377] S805: The AF determines whether to continue to query the time providing service to the UE based on the 5GS clock quality information.

[0378] For example, the AF may compare the fed back 5GS clock quality information with the quality information of another available clock deployed on the AF, and may select the clock with better clock performance as the grandmaster for providing time to the UE.

[0379] For example, the fed back 5GS clock quality information may include the quality level of the 5GS clock, and the AF may select a clock with a higher quality level as the grandmaster for providing time to the UE. In this way, the AF may compare the quality level of the 5GS clock with the quality level of another available clock deployed on the AF. If the quality level of the 5GS clock is lower than the quality level of another available clock deployed on the AF, the AF may decide to provide time to the UE based on the clock with a higher quality level deployed on the AF, rather than continuing to query a time-providing service for the UE. If the quality level of the 5GS clock is higher than the quality level of another available clock deployed on the AF, the AF may decide to continue to query a time-providing service for the UE, for example, by executing S806 below, querying a time-providing service from the TSCTSF.

[0380] In another example, the fed back 5GS clock quality information includes the accuracy of the 5GS clock, and the AF can select a clock with higher accuracy as the grandmaster for providing time to the UE. In this way, the AF can compare the accuracy of the 5GS clock with the accuracy of another available clock deployed on the AF. If the accuracy of the 5GS clock is lower than the accuracy of another available clock deployed on the AF, the AF decides to provide time to the UE based on the higher accuracy clock deployed on the AF rather than continuing to query the time providing service to the UE. If the accuracy of the 5GS clock is higher than the accuracy of another available clock deployed on the AF, the AF decides to continue to query the time providing service to the UE and performs S806 below.

[0381] As yet another example, the 5GS clock quality information fed back in the first response may include the crystal stability of the 5GS clock, and the AF may select a clock with good crystal stability as the grandmaster for providing time to the UE. In this manner, the AF may compare the crystal stability of the 5GS clock with that of another available clock deployed on the AF. If the crystal stability of the 5GS clock is worse than that of another available clock deployed on the AF, the AF may decide to provide time to the UE based on a more accurate clock deployed on the AF rather than continuing to query the time-providing service for the UE. If the crystal stability of the 5GS clock is better than that of another available clock deployed on the AF, the AF may decide to continue to query the time-providing service for the UE and perform step S806 below.

[0382] S806: The AF sends a fourth access stratum clock information time provision request to the TSCTSF. In response, the TSCTSF receives the fourth access stratum clock information time provision request from the AF.

[0383] The fourth access stratum clock information time provision request (ASTI_Create_Req) ​​is used to request the 5GS or TSCTSF to provide time to the UE. The fourth access stratum clock information time provision request carries a UE identifier, an AF identifier, time sync service parameters, and fifth indication information.

[0384] In this embodiment of the present application, the UE identifier is used to identify the UE that needs to be provided with time, and the UE identifier may be a generic public subscription identifier (GPSI) or a subscription permanent identifier (SUPI). The time synchronization service parameters indicate requirements for the time providing service requested by the UE, and the time synchronization service parameters may include one or more of a requested time synchronization type, a clock information requirement, and a time providing information requirement. The time synchronization type may be access stratum time synchronization and / or general precision time protocol (gPTP) time synchronization. The clock information requirement may be a requirement for the accuracy of the clock information. The time providing information requirement may be a requirement for a time synchronization error budget during time providing (which can be referred to as time providing error for short), and the error budget indicates the maximum error of time synchronization in the core network-RAN-UE time providing process. For example, the AF requests an access stratum time synchronization time providing service for the UE, with a clock information accuracy of 0.01 s and a time providing error of no more than 0.05 s. The fifth indication information indicates to the 5GS to provide 5GS clock quality information to the UE. In other words, when providing time to the UE, the 5GS needs to provide 5GS clock quality information to the UE.

[0385] It should be noted that the above steps S801 to S805 are optional steps. Alternatively, the AF can directly send a fourth access stratum clock information time provision request to the TSCTSF, i.e., perform S806, instead of obtaining the 5GS clock quality information to pre-determine whether to query (continue to) the time provision service to the UE.

[0386] If the above steps S801 to S805 are not performed, after receiving the fourth access stratum clock information time provision request, the TSCTSF can acquire 5GS clock quality information based on the fifth instruction information. The process by which the TSCTSF acquires 5GS clock quality information is the same as the above step S803. The details will not be described again in this specification.

[0387] Optionally, if the above steps S801 to S805 are not performed, after receiving the fourth access stratum clock information time provision request, the TSCTSF can first determine whether 5GS clock quality information is deployed on the TSCTSF. If the 5GS clock quality information is deployed on the TSCTSF, continue to execute the following step S807. If the 5GS clock quality information is not deployed on the TSCTSF, the 5GS clock quality information can be obtained from the UPF or OAM. For specific processes, please refer to the relevant description of the above step S803. Details will not be described again in this specification.

[0388] When the aforementioned S801 to S805 are executed, after receiving the fourth access stratum clock information time provision request, the TSCTSF does not need to obtain the 5GS clock quality information, but can directly provide the 5GS clock quality information obtained from S803 and locally stored according to the fifth instruction information to the UE.

[0389] It will be understood that if the aforementioned S801 to S805 are not performed, the AF may alternatively first send a fourth access stratum clock information time provision request to the NEF, and the NEF will send the fourth access stratum clock information time provision request to the TSCTSF after authentication is passed.

[0390] Furthermore, the TSCTSF can determine the RAN that provides time to the UE, and can calculate the RAN air interface time provision error (Uu error budget) based on the error budget. The Uu error budget indicates the maximum error of the time provided by the RAN to the UE. Regarding the Uu error budget, if the fourth access stratum clock information time provision request has a requirement on the upper limit of the error budget, the TSCTSF can obtain the Uu error budget by subtracting the core network time provision error from the error budget requested in the time provision request. If the fourth access stratum clock information time provision request does not have a requirement on the upper limit of the error budget, the TSCTSF can obtain the Uu error budget by subtracting the core network time provision error from the preconfigured error budget. This is not limited to this embodiment of the present application.

[0391] S807: The TSCTSF sends a confirmation request to the RAN. In response, the RAN receives a confirmation request from the TSCTSF.

[0392] The confirmation request is used to confirm whether 5GS clock quality information is deployed on the RAN, and the confirmation request carries information used to confirm whether the RAN has 5GS clock quality information.

[0393] For example, after receiving the fourth access stratum clock information time provision request, the TSCTSF can send a confirmation request to the RAN based on the fifth instruction information to confirm whether the 5GS clock quality information is deployed on the RAN.

[0394] S808: The RAN sends an acknowledgement to the TSCTSF, so that the TSCTSF receives the acknowledgement from the RAN.

[0395] The acknowledgment indicates whether the RAN has 5GS clock quality information. If 5GS clock quality information is deployed on the RAN, the acknowledgment indicates that the RAN has 5GS clock quality information. In this way, the TSCTSF does not need to provide the RAN with 5GS clock quality information. If 5GS clock quality information is not deployed on the TSCTSF, the TSCTSF does not need to obtain 5GS clock quality information from the OAM or UPF, and only needs to notify the RAN that the RAN needs to provide 5GS clock quality information to the UE when providing time to the UE. If 5GS clock quality information is not deployed on the RAN, the acknowledgment indicates that the RAN does not have 5GS clock quality information. In this way, the TSCTSF needs to provide the RAN with 5GS clock quality information. If 5GS clock quality information is not deployed on the TSCTSF, the TSCTSF also needs to obtain 5GS clock quality information from the OAM or UPF.

[0396] It should be understood that the above S807 and S808 are optional steps. The TSCTSF can provide the 5GS clock quality information to the RAN or the UE in the process of indicating to the RAN to provide time to the UE without checking with the RAN whether the RAN has the 5GS clock quality information.

[0397] S809: The TSCTSF sends a second clock subscription data request to the UDM. In response, the UDM receives the second clock subscription data request from the TSCTSF.

[0398] For example, after receiving the fourth access stratum clock information time provision request, if the UE's clock subscription data is deployed on the UDM, the TSCTSF can alternatively send a second clock subscription data request to the UDM and perform time provision to the UE by referring to the UE's clock subscription data.

[0399] The second clock subscription data request (Nudm_SDM_Get_Req) ​​is used to request clock subscription data of the UE, and the second clock subscription data request carries an identifier of the UE. The clock subscription data of the UE may include one or more of a time synchronization type supported by the UE, a time synchronization error tolerated by the UE, and a clock accuracy tolerated by the UE.

[0400] S810: The UDM sends a second clock subscription data response to the TSCTSF. In response, the TSCTSF receives the second clock subscription data response from the UDM.

[0401] The second clock subscription data response (Nudm_SDM_Get_Resp) carries the clock subscription data of the UE.

[0402] In this embodiment of the present application, if the second clock subscription data request indicates which clock subscription data of the UE needs to be acquired, the second clock subscription data response can feedback the required clock subscription data of the UE or all of the clock subscription data of the UE. For example, if the second clock subscription data request is used to request a time synchronization type of the UE's broadcast view, the second clock subscription data response may feedback only the time synchronization type of the UE's broadcast view, or may feedback all of the UE's clock subscription data. Alternatively, if the second clock subscription data request does not indicate which clock subscription data of the UE needs to be acquired, the second clock subscription data response can also feedback some or all of the UE's clock subscription data. This is not limited to this embodiment of the present application.

[0403] Additionally, in some embodiments, if the UE's clock subscription data is not stored in the UDM, the second clock subscription data response may notify the TSCTSFU that there is no clock subscription data for the UE or that the UDM does not have the UE's clock subscription data.

[0404] S811: The TSCTSF determines, based on the clock subscription data of the UE, whether the UE is broadcasting and browsing a time synchronization service corresponding to the time synchronization service parameters.

[0405] For example, if the time synchronization type provided by the UE in the UE's clock subscription data is access stratum time synchronization, but the UE's time synchronization type requested in the time synchronization service parameters in the fourth access stratum clock information time provision request is gPTP time synchronization, the UE's clock subscription data does not support the UE in performing gPTP time synchronization, and the TSCTSF rejects the AF's fourth access stratum clock information time provision request and does not perform the time provision service to the UE. Conversely, if the UE's time synchronization type requested in the time synchronization service parameters in the fourth access stratum clock information time provision request is access stratum time synchronization, the TSCTSF can select a time providing device suitable for the UE based on the requested time synchronization service parameters for the UE, i.e., the time provision service requirements, and activate the device's time provision capability.

[0406] In another example, the UE's clock subscription data indicates that the access stratum time synchronization accuracy provided by the UE is 0.01 seconds, but the access stratum time synchronization accuracy requested in the time synchronization service parameters in the fourth access stratum clock information time provision request is 0.05 seconds. In this case, the UE's clock subscription data does not support access stratum time synchronization with an accuracy of 0.05 seconds, and the TSCTSF rejects the AF's fourth access stratum clock information time provision request and does not perform the time provision service for the UE. Conversely, if the access stratum time synchronization accuracy requested in the time synchronization service parameters in the fourth access stratum clock information time provision request is 0.01 seconds, the TSCTSF can select a time providing device suitable for the UE based on the time synchronization service parameters requested for the UE, i.e., the time provision service requirements, and activate the device's time provision capability.

[0407] It should be noted that in this embodiment of the present application, the RAN is selected as the clock source, i.e., the time providing device, to provide 5GS clock information to the UE.

[0408] If the TSCTSF determines, based on the UE's clock subscription data, that the UE is viewing a time synchronization service corresponding to the time synchronization service parameters, the TSCTSF may determine to activate the RAN's time provisioning capability for the UE, and may calculate a RAN air interface time provisioning error (Uu error budget) based on the error budget. The Uu error budget indicates the maximum error of the RAN's time provisioning to the UE. Regarding the Uu error budget, if the fourth access stratum clock information time provisioning request has a requirement for an upper limit of the error budget, the TSCTSF may obtain the Uu error budget by subtracting the core network time provisioning error from the error budget required in the first access stratum clock information time provisioning request. If the first access stratum clock information time provisioning request does not have a requirement for an upper limit of the error budget, the TSCTSF may obtain the Uu error budget by subtracting the core network time provisioning error from the preconfigured error budget. This is not limited to this embodiment of the present application.

[0409] It should be understood that the above steps S808 to S811 are optional. For example, if the clock subscription data of the UE is not stored in the UDM, the above steps S808 to S811 may not be executed. In other words, the TSCTSF can provide the time providing service to the UE based on a time providing request, rather than providing the time providing service to the UE by referring to the clock subscription data of the UE.

[0410] In addition, the above-described steps S807 and S808, and steps S809 to S811 are all optional steps. The above-described steps S807 and S808, and steps S809 to S811 may or may not be executed, or only one of the above-described steps S807 and S808, and steps S809 to S811 may be executed. When both of the above-described steps S807 and S808, and steps S809 to S811 may be executed, the order in which the steps S807 and S808, and steps S809 to S811 are executed is not limited.

[0411] S812: The TSCTSF sends an access and mobility (AM) policy creation / update request to the PCF. In response, the PCF receives an AM policy creation / update request from the TSCTSF.

[0412] For example, after receiving the fourth access stratum clock information time provisioning request, if the TSCTSF decides to continue providing time to the UE and / or if the RAN does not have 5GS clock quality information, it initiates an AM policy creation / update request to the PCF to continue the subsequent time provisioning procedure. The AM policy creation / update request (AMPolicyAuthorization_Create / Update req) carries UE time synchronization data (UE Time Sync Data) and 5GS clock quality information. The UE time synchronization data may include a time provisioning capability activation indication (also referred to as a time provisioning indication) and a Uu error budget, and the time provisioning capability activation indication is used to activate the RAN's time provisioning capability.

[0413] S813: The PCF initiates an AM policy update for the UE to the AMF.

[0414] In the process in which the PCF and the AMF update the UE's AM policy, the PCF sends the UE time synchronization data and the 5GS clock quality information to the AMF. Note that in this implementation of the present application, the AM policy update process refers to the existing implementation process, and details are not described in this specification.

[0415] S814: The AMF sends a second UE context modification request to the RAN. In response, the RAN receives a second UE context modification request from the AMF.

[0416] The second UE context modification request (UE Context Modification req) carries UE time synchronization data and 5GS clock quality information and is used to configure the time serving capability of the RAN. The RAN can enable the time serving capability based on the time serving capability enabling indication in the UE time synchronization data, and can provide 5GS clock information to the UE based on the Uu error budget.

[0417] S815: The RAN provides the time to the UE.

[0418] For example, the RAN may provide time to the UE based on the Uu error budget and may transmit 5GS clock quality information to the UE when transmitting 5GS clock information to the UE. The 5GS clock quality information may be used by the UE to determine whether the RAN needs to continue providing time to the UE. The RAN may transmit the 5GS clock information and the 5GS clock quality information using an RRC message or an SIB message. For example, the RAN broadcasts SIB19 to provide time to the UE together with the 5GS clock quality information. In other words, SIB19 carries the 5GS clock information and the 5GS clock quality information.

[0419] Optionally, when providing time to the UE, the RAN may alternatively not transmit 5GS clock quality information to the UE but only provide the 5GS clock information to the UE. Instead, the AMF transmits an NAS message to the UE, and the NAS message includes the 5GS clock quality information. In other words, the AMF initiates a DL NAS message to transparently transmit the 5GS clock quality information to the UE via the RAN, and the RAN only performs time provisioning to the UE.

[0420] S816: The RAN sends a second UE context modification response to the AMF. In response, the AMF receives a second UE context modification response from the RAN.

[0421] The second UE Context Modification response may be used to notify the AMF that time provision to the UE has been completed.

[0422] S817: The PCF sends an AM policy creation / update response to the TSCTSF. In response, the TSCTSF receives an AM policy creation / update response from the PCF.

[0423] The AM Policy Create / Update response (AMPolicyAuthoritation_Create / Update resp) may be used to notify the TSCTSF that time provisioning to the UE has been completed.

[0424] S818: The TSCTSF sends a fourth access stratum clock information time provision response to the AF. In response, the AF receives a fourth access stratum clock information time provision response from the TSCTSF.

[0425] The fourth access stratum clock information time provision response (ASTI_Create_Resp) may be used to notify the AF that time provisioning to the UE has been completed.

[0426] Then, after receiving the 5GS clock quality information, the UE can alternatively determine whether the RAN needs to continue providing time to the UE based on the 5GS clock quality information. For details, please refer to the relevant descriptions of S512 to S518 above. The details will not be described again in this specification.

[0427] In addition to the methods for indicating the stop of time provision described above in S512 to S518, the UE can alternatively send a time provision stop request to the AF via the application layer, which carries sixth indication information, and the sixth indication information indicates that the AF requests the UE to stop querying the time provision service so as to no longer provide 5GS clock information to the UE.

[0428] Based on the communication method shown in Figure 8, the AF can request the 5GS to synchronize the 5GS clock information to the UE. In the time provision request sent to the TSCTSF, the AF indicates that the 5GS will provide the 5GS clock quality information to the UE, so that the 5GS clock quality information can be distributed to the RAN and the UE in the process of providing time to the UE.

[0429] It will be understood that in the foregoing embodiments, the methods and / or steps performed by the first network element may alternatively be performed by components (e.g., processors, chips, chip systems, circuits, logic modules, or software) that may be used in the first network element. The methods and / or steps performed by the second network element may alternatively be performed by components (e.g., processors, chip systems, circuits, logic modules, or software) that may be used in the second network element. The methods and / or steps performed by the time synchronization network element may alternatively be performed by components (e.g., processors, chips, chip systems, circuits, logic modules, or software) that may be used in the time synchronization network element. The methods and / or steps performed by the application network element may alternatively be performed by components (e.g., processors, chips, chip systems, circuits, logic modules, or software) that may be used in the application network element. The methods and / or steps performed by the terminal device may alternatively be performed by components (e.g., processors, chips, chip systems, circuits, logic modules, or software) that may be used in the terminal device.

[0430] The above mainly describes the solution provided in the present application. Correspondingly, the present application also provides a communication device. The communication device is configured to execute the method of the aforementioned method embodiment. The communication device may be the first network element, a device including the first network element, or a component that can be used in the first network element, such as a chip or chip system, in the aforementioned method embodiment. Alternatively, the communication device may be the second network element, a device including the second network element, or a component that can be used in the second network element, such as a chip or chip system, in the aforementioned method embodiment. Alternatively, the communication device may be the time synchronization network element, a device including the time synchronization network element, or a component that can be used in the time synchronization network element, such as a chip or chip system, in the aforementioned method embodiment. Alternatively, the communication device may be the application network element, a device including the application network element, or a component that can be used in the application network element, such as a chip or chip system, in the aforementioned method embodiment. Alternatively, the communication device may be the terminal device, a device including the terminal device, or a component that can be used in the terminal device, such as a chip or chip system, in the aforementioned method embodiment.

[0431] It should be understood that to realize the above-described functions, the communication device includes corresponding hardware structures and / or software modules for performing the functions. Those skilled in the art should easily understand that, in combination with the example units and algorithm steps described in the embodiments disclosed herein, the present application can be implemented by hardware or a combination of hardware and computer software. Whether the functions are performed by hardware or by hardware driven by computer software depends on the specific application and design constraints of the technical solution. Professionals may use different methods to realize the described functions for each specific application, but the implementation should not be considered beyond the scope of the present application.

[0432] In the embodiments of the present application, the communication device may be divided into functional modules based on the above-described method embodiments. For example, each functional module may be obtained by dividing the functional modules based on the corresponding functions, or two or more functions may be integrated into one processing module. The integrated module may be implemented in the form of hardware or a software functional module. It should be noted that the module division in the embodiments of the present application is an example and is merely a logical division of functions. In actual implementation, other division schemes may be used.

[0433] For example, the communication device may be a first network element, a second network element, a time synchronization network element, an application network element, or a terminal device in the above-described method embodiments. Figure 9 is a diagram of the structure of a communication device according to an embodiment of the present application. As shown in Figure 9, the communication device 900 includes a processing module 901 and a transceiver module 902.

[0434] The processing module 901 is configured to perform a processing function of the first network element, the second network element, the time synchronization network element, the application network element, or the terminal device in the implementation of the above-mentioned method. The transceiver module 902 is configured to perform a transceiver function of the first network element, the second network element, the time synchronization network element, the application network element, or the terminal device.

[0435] Optionally, the transceiver module 902 may include a transmitting module and a receiving module (not shown in FIG. 9 ), where the transmitting module is configured to implement a transmitting function of the communication device 900, and the receiving module is configured to implement a receiving function of the communication device 900.

[0436] Optionally, the communication device 900 may further include a storage module (not shown in FIG. 9 ) for storing programs or instructions. When the processing module 903 executes the programs or instructions, the communication device 900 is enabled to perform the functions of the first network element, the second network element, the time synchronization network element, the application network element, or the terminal device in the communication method shown in FIG. 4 or FIG. 7 .

[0437] All relevant contents of the steps in the foregoing method embodiments can be cited in the functional descriptions of the corresponding functional modules, and the details will not be described again in this specification.

[0438] The communication device 900 provided in this implementation can perform the aforementioned communication method. Therefore, please refer to the aforementioned method embodiments for the technical effects that can be achieved by the communication device 900. Details will not be described again in this specification.

[0439] It should be understood that the processing module 901 in the communication device 900 may be implemented by a processor or processor-related circuitry, and may be a processor or a processing unit. The transceiver module 902 may be implemented by a transceiver or transceiver-related circuitry, and may be a transceiver or a transceiver unit.

[0440] For example, Figure 10 is a diagram of the structure of another communication device according to an embodiment of the present application. The communication device may be a terminal device or a network device, or may be a chip (system) or another part or component that may be disposed in the terminal device or the network device. As shown in Figure 10, the communication device 1000 may include a processor 1001. Optionally, the communication device 1000 may further include a memory 1002 and / or a transceiver 1003. The processor 1001 is coupled to the memory 1002, and the transceiver 1003 may be connected via a communication bus, for example.

[0441] The components of the communication device 1000 will be specifically described below with reference to FIG.

[0442] Processor 1001 is the control center of communication device 1000 and may be a single processor or a collective term for multiple processing elements. For example, processor 1001 may be one or more central processing units (CPUs), or an application specific integrated circuit (ASIC), or may be configured as one or more integrated circuits for implementing embodiments of the present application, such as one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (FPGAs).

[0443] Optionally, the processor 1001 can perform various functions of the communication device 1000 by launching or executing software programs stored in the memory 1002 and by accessing data stored in the memory 1002.

[0444] In a specific implementation, in one embodiment, the processor 1001 may include one or more CPUs, for example, CPU 0 and CPU 1 shown in FIG.

[0445] In a specific implementation, in one embodiment, the communications device 1000 may alternatively include multiple processors, such as the processor 1001 and processor 1004 shown in FIG. 10. Each of the processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). A processor herein may refer to one or more devices, circuits, and / or processing cores configured to process data (e.g., computer program instructions).

[0446] The memory 1002 is configured to store a software program for implementing the solution of the present application, and the processor 1001 controls the execution of the software program. For specific implementation, please refer to the aforementioned method embodiment. Details will not be described again in this specification.

[0447] Optionally, memory 1002 may be, but is not limited to, read-only memory (ROM) or another type of static storage device capable of storing static information and instructions, random access memory (RAM) or another type of dynamic storage device capable of storing information and instructions, electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other compact disc storage device, optical disc storage device (including compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), magnetic disc storage medium or other magnetic storage device, or any other medium that can be used to carry or store expected program code in the form of instructions or data structures and that can be accessed by a computer. Memory 1002 may be integrated with processor 1001 or may exist independently, and is coupled to processor 1001 via an interface circuit (not shown in FIG. 10 ) of communication device 1000, which is not specifically limited in this embodiment of the present application.

[0448] The transceiver 1003 is configured to communicate with other communication devices. For example, the communication device 1000 is a terminal device, and the transceiver 1003 may be configured to communicate with a network device or with another terminal device. In another example, the communication device 1000 is a network device, and the transceiver 1003 may be configured to communicate with a terminal device or with another network device.

[0449] Optionally, the transceiver 1003 may include a receiver and a transmitter (not shown separately in FIG. 10 ), where the receiver is configured to implement a receiving function and the transmitter is configured to implement a transmitting function.

[0450] In some cases, the transceiver 1003 may be integrated with the processor 1001 or may exist independently and be coupled to the processor 1001 via an interface circuit (not shown in FIG. 10) of the communication device 1000, which is not specifically limited in this embodiment of the present application.

[0451] It should be noted that the structure of the communications device 1000 shown in Figure 10 is not intended to be limiting of the communications device. An actual communications device may include more or fewer components than those shown in the figure, may combine some components, or may have a different arrangement of components.

[0452] In addition, for the technical effects of the communication device 1000, please refer to the technical effects of the communication method in the above method embodiments, and the details will not be described again in this specification.

[0453] An embodiment of the present application provides a communication system, which includes a first network element, a second network element, and a terminal device.

[0454] An embodiment of the present application provides another communication system, which includes a time synchronization network element, an application network element, and a terminal device.

[0455] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program or instruction, and when the computer program or instruction is executed by a computer, the function of any one of the embodiments described in the above-mentioned method is realized.

[0456] An embodiment of the present application further provides a computer program product, which, when executed by a computer, implements the functions of any one of the embodiments described in the above-mentioned method.

[0457] It should be understood that the term "and / or" in this specification describes only the relational relationship between related objects and indicates that three relationships may exist. For example, A and / or B may represent three cases: only A is present, both A and B are present, or only B is present. A and B may be singular or plural. In addition to the above, the character " / " in this specification usually indicates an "or" relationship between related things, but may also indicate an "and / or" relationship. For more details, please refer to the context for understanding.

[0458] In this application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following items" or similar expressions means any combination of those items, including any combination of single items or multiple items. For example, at least one of a, b, or c can refer to a, b, c, ab, ac, bc, or abc, where a, b, and c may be singular or plural.

[0459] It should be understood that the sequence numbers of the processes do not imply an execution sequence in various embodiments of the present application. The execution order of the above processes should be determined based on the functions and internal logic of the processes, and should not be construed as any limitation on the implementation process of the embodiments of the present application.

[0460] Those skilled in the art will understand that, in combination with the examples described in the embodiments disclosed herein, the steps of the units and algorithms can be implemented by electronic hardware or by a combination of computer software and electronic hardware. Whether a function is performed by hardware or software depends on the specific application and design constraints of the technical solution. Professionals may use different methods to realize the described functions for each specific application, but the implementation should not be considered beyond the scope of this application.

[0461] For the purpose of easy description, it is clearly understood by those skilled in the art that the detailed working processes of the aforementioned systems, devices and units should be referred to the corresponding processes of the aforementioned method embodiments, and the details will not be described again in this specification.

[0462] In some embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the described device embodiments are merely examples. For example, the division into units is merely a logical division of function, and other divisions may be used in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented. In addition, indicated or described mutual couplings or direct couplings or communication connections may be realized through some interfaces. Indirect couplings or communication connections between one or more devices may be realized in electrical, mechanical, or other forms.

[0463] Units described as separate parts may or may not be physically separate, and parts presented as units may or may not be physical units, in other words, may be located in one place or distributed across multiple network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions of the embodiments.

[0464] In addition, the functional units in the embodiments of the present application may be integrated into one processing unit, or each of the units may exist physically alone, or two or more units may be integrated into one unit.

[0465] When a function is implemented in the form of a software functional unit and sold or used as an independent product, the function may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or a portion contributing to the prior art, or some of the technical solutions may be implemented in the form of a software product. The computer software product is stored in a storage medium and includes some instructions for instructing a computer device (which may be a personal computer, a server, a network device, etc.) to execute all or some of the steps of the method described in the implementation form of the present application. The storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0466] The above description is merely a specific implementation of the present application. However, the scope of protection of the present application is not limited thereto. Any modifications or replacements that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application shall fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims. [Explanation of symbols]

[0467] 900 Communication Equipment 901 Processing Module 902 Transceiver Module 1000 Communication Equipment 1001 processor 1002 memory 1003 Transceiver 1004 processor

Claims

1. 1. A communication method comprising: determining, by a first network element, that quality information of a first clock needs to be obtained, the first clock being a reference clock of a wireless communication system; sending, by the first network element, a first indication to a second network element, the first indication indicating to acquire the quality information of the first clock; receiving, by the first network element, the quality information of the first clock from the second network element; transmitting, by the first network element, the quality information of the first clock to a terminal device; A method comprising:

2. The first network element is a mobility management network element, and the step of determining that quality information of a first clock needs to be obtained by the first network element includes: sending, by the first network element, to an access network device, information used to verify whether the access network device has the quality information of the first clock; receiving, by the first network element, an acknowledgement from the access network device, the acknowledgement indicating that the access network device does not have the quality information for the first clock; determining, by the first network element, based on the acknowledgment, that the quality information of the first clock needs to be obtained; 2. The method of claim 1, comprising:

3. the step of transmitting, by the first network element, the quality information of the first clock to a terminal device, 3. The method of claim 2, further comprising: transmitting, by the first network element, a non-access stratum (NAS) message to the terminal device, the NAS message including the quality information of the first clock.

4. The method comprises: receiving, by the first network element, second indication information from the terminal device, the second indication information indicating that the terminal device requests to stop providing time; sending, by the first network element, third instruction information to the access network device, the third instruction information indicating that the access network device should stop providing time to the terminal device; 4. The method of claim 2 or 3, further comprising:

5. The method according to any one of claims 2 to 4, wherein the second network element is an operation, administration and maintenance network element or a time synchronization network element.

6. The first network element is an access network device, and the step of determining that quality information of a first clock needs to be obtained by the first network element includes: receiving, by the first network element, a time providing request from the terminal device, the time providing request including the first indication information; determining, by the first network element, based on the first indication, whether the first network element has the quality information of the first clock; determining, by the first network element, when determining that the first network element does not have the quality information of the first clock, that the quality information of the first clock needs to be acquired; 2. The method of claim 1, comprising:

7. The method comprises: receiving, by the first network element, second indication information from the terminal device, the second indication information indicating that the terminal device requests to stop providing time; sending, by the first network element, a fourth indication to the terminal device, the fourth indication indicating that the first network element has stopped providing time to the terminal device; 7. The method of claim 6, further comprising:

8. the step of transmitting, by the first network element, the quality information of the first clock to a terminal device, 8. The method of claim 6, further comprising: transmitting, by the first network element, a radio resource control (RRC) message to the terminal device, wherein the RRC message includes the quality information of the first clock.

9. the step of transmitting, by the first network element, the quality information of the first clock to a terminal device, 8. The method of claim 6, further comprising the step of transmitting, by the first network element, a system message to the terminal device, the system message including the quality information of the first clock.

10. 10. The method of claim 1, wherein the quality information of the first clock comprises one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time (UTC) traceability.

11. 1. A communication method comprising: receiving, by a second network element, first indication information from a first network element, the first indication information indicating to obtain quality information of a first clock, the first clock being a reference clock of a wireless communication system; obtaining, by the second network element, the quality information of the first clock based on the first indication; transmitting, by the second network element, the quality information of the first clock to the first network element; A method comprising:

12. The second network element is a time synchronization network element, and the step of obtaining, by the second network element, the quality information of the first clock based on the first indication information includes: sending, by the second network element, a first message to a user plane network element based on the first indication information, the first message being used to request the quality information of the first clock; receiving, by the second network element, the quality information of the first clock from the user plane network element; 12. The method of claim 11, comprising:

13. The second network element is a time synchronization network element, and the step of obtaining, by the second network element, the quality information of the first clock based on the first indication information includes: sending, by the second network element, a second message to an operation, management and maintenance network element based on the first indication information, the second message being used to request the quality information of the first clock; receiving, by the second network element, the quality information of the first clock from the operation, administration and maintenance network element; 12. The method of claim 11, comprising:

14. The method comprises: receiving, by the second network element, second indication information from a terminal device, the second indication information indicating that the terminal device requests to stop providing time; sending, by the second network element, third instruction information to the access network device, the third instruction information indicating that the access network device should stop providing time to the terminal device; 14. The method of claim 12 or 13, further comprising:

15. 15. The method of claim 11, wherein the first network element is a mobility management network element or an access network device.

16. The method of claim 11 , wherein the first network element is a mobility management network element and the second network element is an operation, administration and maintenance network element.

17. 17. The method of claim 11, wherein the quality information of the first clock comprises one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time (UTC) traceability.

18. 1. A communication method comprising: receiving, by a time synchronization network element, fifth indication information from an application network element, the fifth indication information indicating that a wireless communication network provides quality information of a first clock to a terminal device, the first clock being a reference clock of the wireless communication system; obtaining, by the time synchronization network element, the quality information of the first clock based on the fifth indication; transmitting, by the time synchronization network element, the quality information of the first clock to the terminal device; A method comprising:

19. The step of obtaining, by the time synchronization network element, the quality information of the first clock based on the fifth indication information, sending, by the time synchronization network element, a third message to a user plane network element based on the fifth indication information, wherein the third message is used to request the quality information of the first clock; receiving, by the time synchronization network element, the quality information of the first clock from the user plane network element; 20. The method of claim 18, comprising:

20. The step of obtaining, by the time synchronization network element, the quality information of the first clock based on the fifth indication information, sending, by the time synchronization network element, a fourth message to an operation, management and maintenance network element based on the fifth indication information, wherein the fourth message is used to request the quality information of the first clock; receiving, by the time synchronization network element, the quality information of the first clock from the operation, administration, and maintenance network element; 20. The method of claim 18, comprising:

21. Before the step of receiving, by the time synchronization network element, fifth indication information from the application network element, the method further comprises: receiving, by the time synchronization network element, first indication information from the application network element, the first indication information indicating to obtain the quality information of the first clock, the quality information of the first clock being used by the application network element to determine whether to continue to query a time providing service to the terminal device; obtaining, by the time synchronization network element, the quality information of the first clock based on the first indication; transmitting, by the time synchronization network element, the quality information of the first clock to the application network element; further comprising Correspondingly, the step of obtaining, by the time synchronization network element, the quality information of the first clock based on the fifth indication information, comprises:

20. The method of claim 18, comprising locally obtaining, by the time synchronization network element, the quality information of the first clock based on the fifth indication.

22. the step of transmitting, by the time synchronization network element, the quality information of the first clock to the terminal device, sending, by the time synchronization network element, to an access network device, information used to verify whether the access network device has the quality information of the first clock; receiving, by the time synchronization network element, an acknowledgement from the access network device, the acknowledgement indicating that the access network device does not have the quality information of the first clock; transmitting, by the time synchronization network element, the quality information of the first clock to the terminal device based on the acknowledgement; 22. The method of any one of claims 18 to 21, comprising:

23. The method comprises: receiving, by the time synchronization network element, second indication information from the terminal device, the second indication information indicating that the terminal device requests to stop providing time; sending, by the time synchronization network element, third indication information to the access network device, the third indication information indicating that the access network device should stop providing time to the terminal device; 23. The method of any one of claims 18 to 22, further comprising:

24. 24. The method of claim 18, wherein the quality information of the first clock comprises one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time (UTC) traceability.

25. 1. A communication method comprising: A method comprising: a step of sending fifth indication information by an application network element to a time synchronization network element, the fifth indication information indicating that a wireless communication system provides quality information of a first clock to a terminal device, and the first clock is a reference clock of the wireless communication system.

26. before the step of sending fifth indication information by the application network element to the time synchronization network element; sending, by the application network element, first indication information to the time synchronization network element, the first indication information indicating that the quality information of the first clock is to be acquired; receiving, by the application network element, the quality information of the first clock from the time synchronization network element; determining, by the application network element, based on the quality information of the first clock, to continue to query a time providing service to the terminal device; 26. The method of claim 25, further comprising:

27. The method comprises: The method of claim 25 or 26, further comprising a step of receiving, by the application network element, sixth instruction information from the terminal device, the sixth instruction information indicating that the application network element requests the terminal device to stop querying a time-providing service.

28. 28. The method of claim 25, wherein the quality information of the first clock comprises one or more of a quality level, a crystal stability, an accuracy, or a Coordinated Universal Time (UTC) traceability.

29. a communication device comprising a processing module and a transceiver module; The processing module is configured to perform the processing functions of the method of any one of claims 1 to 28, 29. A communications device, wherein the transceiver module is configured to perform the transceiver functions of the method of any one of claims 1 to 28.

30. 1. A communications device comprising: a processor, the processor coupled to a memory; the memory is configured to store a computer program; 29. A communications device, wherein the processor is configured to execute the computer program stored in the memory to enable the communications device to perform the communications method of any one of claims 1 to 28.

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