Time synchronization method, time synchronization apparatus, electronic device, and storage medium

Abstract

The present application discloses a time synchronization method, a time synchronization apparatus, an electronic device, and a storage medium. The method comprises: a second terminal device sends a first message to a first terminal device, the first message comprising a time synchronization mode supported by the second terminal device; and the first terminal device provides time synchronization to the second terminal device on the basis of the time synchronization mode supported by the second terminal device. According to the embodiments of the present application, the first terminal device and the second terminal device determine a time synchronization mode by means of a negotiation process and then perform time synchronization, so that regardless of whether the second terminal device is within the coverage of a wireless access network, the first terminal device can provide time synchronization for the second terminal device by means of ProSe, without heavily relying on the access network device for time synchronization; thus, the present application allows to provide time synchronization for a terminal device in a more reasonable manner, helping to ensure the reliability and effectiveness of time synchronization.

Description

Timing method, timing device, electronic device and storage medium

[0001] This application claims priority to the Chinese patent application with application number 202311692506.9 filed with the State Intellectual Property Office of China on December 9, 2023, and priority to the Chinese patent application with the invention name “Time service method, time service device, electronic device and storage medium”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication network technology, and in particular to a timing method, a timing device, an electronic device, and a storage medium. Background Art

[0003] New wireless communication scenarios are enabling collaborative tasks among multiple user equipment (UEs). UEs can communicate directly with each other using Sidelink technology. Sidelink technology can also be used for device-to-device (D2D) and vehicle-to-everything (V2X) communications. In this multi-UE collaborative mode, each UE may operate in a different network environment. Therefore, ensuring reliable and effective timing for slave UEs is a pressing issue. Summary of the Invention

[0004] The embodiments of the present application provide a timing method, a timing device, an electronic device, and a storage medium.

[0005] In a first aspect, an embodiment of the present application provides a timing method, applied to a first terminal device, the method comprising:

[0006] receiving a first message from a second terminal device; the first message including a timing mode supported by the second terminal device;

[0007] Based on the timing mode supported by the second terminal device, provide time for the second terminal device.

[0008] It can be seen that in the embodiment of the present application, the first terminal device can receive the timing mode sent by the second terminal device, and thus can provide time to the second terminal device based on the timing mode supported by the second terminal device. The first terminal device and the second terminal device determine the timing mode through a negotiation process and perform timing, so that whether the second terminal device is within the coverage of the wireless access network, the first terminal device can provide time to the second terminal device through the proximity service ProSe, without having to rely heavily on the access network device for timing, thereby achieving a more reasonable way to provide time to the terminal device, which is conducive to ensuring the reliability and effectiveness of the timing.

[0009] In one possible implementation, the timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing, and base station timing;

[0010] The timing modes supported by the first terminal device include one or more of broadcast timing, unicast timing, PTP timing and base station timing.

[0011] In this implementation, the first terminal device and the second terminal device can multiplex PTP timing according to their own capabilities on the basis of supporting broadcast timing and unicast timing, which is conducive to enhancing the selectivity of timing.

[0012] In one possible implementation, providing time to the second terminal device based on a time service mode supported by the second terminal device includes:

[0013] Determining a timing mode for timing the second terminal device based on the timing mode supported by the first terminal device and the timing mode supported by the second terminal device; wherein the timing mode for timing the second terminal device is one of the intersections of the timing mode supported by the first terminal device and the timing mode supported by the second terminal device;

[0014] The second terminal device is provided with time service based on the determined time service method.

[0015] In this implementation, when the second terminal device sends the timing mode it supports, the first terminal device can determine the specific timing mode for providing time to the second terminal device based on the timing mode supported by itself and the timing mode supported by the second terminal device. This is relatively more friendly to provide time to the second terminal device in a negotiated manner.

[0016] In one possible implementation, providing time to the second terminal device based on a time service mode supported by the second terminal device includes:

[0017] If the timing mode determined is PTP timing, a PTP message is sent to the second terminal device via a direct link between the terminal device and the second terminal device; wherein a direct link refers to a link in which two terminal devices communicate directly, or a link in which two terminal devices communicate via another terminal device (i.e., a relay terminal device) without passing through any network node;

[0018] Among them, the PTP message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the first clock deviation after obtaining the first clock deviation from the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0019] In this implementation, the first terminal device can send the master clock time information of the group to which the second terminal device belongs to the second terminal device by multiplexing PTP timing. This allows the second terminal device to obtain the clock deviation from the first terminal device through interaction with the first terminal device and then use the time information sent by the first terminal device and the clock deviation to synchronize its clock. In addition, based on the direct link between the first terminal device and the second terminal device, the first terminal device can transmit time information to the second terminal device, overcoming the defect of existing ProSe communication that cannot transmit absolute time information, thereby realizing timing based on ProSe services.

[0020] In one possible implementation, providing time to the second terminal device based on a time service mode supported by the second terminal device includes:

[0021] If the timing mode is determined to be broadcast timing, a sidelink broadcast message is sent;

[0022] If the determined timing mode is unicast timing, sending a first unicast message to the second terminal device through the direct link between the second terminal device and the second terminal device;

[0023] Among them, the sidelink broadcast message or the first unicast message includes the first time information and the group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0024] In this implementation, the first terminal device can send the master clock time information of the group to which the second terminal device belongs to the second terminal device via sidelink broadcast or unicast, so that the second terminal device can synchronize its clock using the time information and propagation delay sent by the first terminal device after obtaining the propagation delay with the first terminal device through interaction with the first terminal device. The sidelink broadcast message or the first unicast message includes the group identifier of the group to which the second terminal device belongs, which enhances the sidelink broadcast message or unicast message. Based on the direct link with the second terminal device, the first terminal device can transmit time information to the second terminal device, overcoming the defect that absolute time information cannot be transmitted in existing ProSe communications, thereby realizing time synchronization based on ProSe services.

[0025] In a possible implementation, the propagation delay is obtained by the first terminal device and the second terminal device based on a round-trip time (RTT) measurement mechanism.

[0026] In this implementation, the first terminal device and the second terminal device can obtain the propagation delay between the two based on the RTT measurement mechanism, and can use the propagation delay to correct the clock synchronization error, which is beneficial to improving the timing accuracy.

[0027] In a possible implementation, before receiving the first message from the second terminal device, the method further includes:

[0028] Sending a direct communication request to the second terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that ProSe timing service needs to be performed by establishing a direct link;

[0029] The first message is sent when the second terminal device determines that the identifier of at least one target terminal device includes the identifier of the second terminal device.

[0030] In this implementation, when the identifier of at least one target terminal device includes the identifier of the second terminal device, the first terminal device will receive the acceptance message (i.e., the first message) sent by the second terminal device, thereby establishing a direct link with the second terminal device, and can determine a reasonable timing method based on the timing method sent by the second terminal device through the acceptance message to provide time for the second terminal device.

[0031] In a possible implementation, before receiving the first message from the second terminal device, the method further includes:

[0032] Sending a direct communication request to the second terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that ProSe timing service needs to be performed by establishing a direct link;

[0033] The first message is sent when the second terminal device determines that the identifier of at least one target terminal device does not include the identifier of the second terminal device and ProSe timing service is required.

[0034] In this implementation, when the identifier of at least one target terminal device does not include the identifier of the second terminal device and the second terminal device needs to perform ProSe timing service, the first terminal device will receive an acceptance message (i.e., the first message) sent by the second terminal device, thereby establishing a direct link with the second terminal device, and can determine a reasonable timing method based on the timing method reported by the second terminal device through the acceptance message to provide time for the second terminal device.

[0035] In one possible implementation, the direct communication request is sent when the path preference corresponding to the ProSe service information is a PC5 interface. The ProSe service may specifically be a ProSe timing service.

[0036] In this implementation, if the path preference of the ProSe service is the PC5 interface, the first terminal device can initiate the process of establishing a direct link by sending a direct communication request.

[0037] In a possible implementation, the method further includes:

[0038] Receive a second clock deviation sent by the access network device; the second clock deviation is the clock deviation between the master clock terminal device and the access network device;

[0039] Upload the second clock offset to the application layer; or,

[0040] The second clock deviation is sent to the unified data management network element for storage.

[0041] In this implementation, the first terminal device can receive the second clock deviation sent by the access network device and send it to the application layer, or store it in the unified data management network element, so that when the direct link between the second terminal device and the first terminal device is disconnected or the second terminal device only supports base station timing or the path preference corresponding to the timing service in the ProSe service is the Uu interface, the second terminal device can obtain the second clock deviation from the application layer or send the second clock deviation through the access network device, thereby ensuring that the second terminal device can synchronize the clock with the master clock terminal device of the group to which it belongs through the access network device, thereby ensuring the reliability and continuity of timing for the second terminal device.

[0042] In a second aspect, an embodiment of the present application provides a timing method, applied to a second terminal device; the method includes:

[0043] A first message is sent to a first terminal device; the first message includes a timing mode supported by a second terminal device; the timing mode supported by the second terminal device is used by the first terminal device to provide timing to the second terminal device.

[0044] It can be seen that in the embodiment of the present application, the second terminal device can send the timing mode it supports to the first terminal device, so that the first terminal device can provide time to the second terminal device based on the timing mode supported by the second terminal device. The first terminal device and the second terminal device determine the timing mode and perform timing through a negotiation process, so that whether the second terminal device is within the coverage of the wireless access network, the first terminal device can provide time to the second terminal device through ProSe, without having to rely heavily on the access network device for timing, thereby achieving a more reasonable way to provide time to the terminal device, which is conducive to ensuring the reliability and effectiveness of the timing.

[0045] In one possible implementation, the timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing, and base station timing;

[0046] The timing modes supported by the first terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing and base station timing.

[0047] In this implementation, the first terminal device and the second terminal device can multiplex PTP timing according to their own capabilities on the basis of supporting broadcast / unicast timing, which is conducive to enhancing the selectivity of timing.

[0048] In a possible implementation, the method further includes:

[0049] Receiving a PTP message sent by the first terminal device through a direct link between the first terminal device and the second terminal device;

[0050] Among them, the PTP message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the first clock deviation after obtaining the first clock deviation from the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group to which the second terminal device belongs.

[0051] In this implementation, the second terminal device can obtain the time information sent by the first terminal device through the PTP message sent by the first terminal device. After obtaining the clock deviation from the first terminal device through interaction with the first terminal device, the second terminal device can use the time information sent by the first terminal device and the clock deviation from the first terminal device to synchronize its clock. In addition, based on the direct link with the first terminal device, the second terminal device can receive the time information transmitted by the first terminal device, overcoming the defect of existing ProSe communication that cannot transmit absolute time information, thereby realizing time synchronization based on ProSe services.

[0052] In a possible implementation, the method further includes:

[0053] receiving at least one sidelink broadcast message; wherein the at least one sidelink broadcast message includes a sidelink broadcast message sent by a first terminal device; the sidelink broadcast message sent by the first terminal device includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of a group to which the second terminal device belongs; the first time information is used by the second terminal device to perform clock synchronization based on the first time information and the propagation delay after obtaining a propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is a master clock time of the group; or,

[0054] Receive a first unicast message sent by a first terminal device through a direct link between the first terminal device and the second terminal device; wherein the first unicast message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of the group to which the second terminal device belongs; the first time information is used by the second terminal device to synchronize its clock based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group to which the second terminal device belongs.

[0055] In this implementation, the second terminal device can obtain the time information sent by the first terminal device through the sidelink broadcast message or the first unicast message sent by the first terminal device, so that after obtaining the propagation delay with the first terminal device through interaction with the first terminal device, the second terminal device can use the time information sent by the first terminal device and the propagation delay to synchronize the clock. The sidelink broadcast message or the first unicast message includes the group identifier of the group to which the second terminal device belongs, which enhances the sidelink broadcast message or unicast message. Based on the direct link with the first terminal device, the second terminal device can obtain the time information transmitted by the first terminal device, which overcomes the defect that the absolute time information cannot be transmitted in the existing ProSe communication, thereby realizing time synchronization based on the ProSe service.

[0056] In a possible implementation, the propagation delay is obtained by the first terminal device and the second terminal device based on an RTT measurement mechanism.

[0057] In this implementation, the second terminal device and the first terminal device can obtain the propagation delay between the two based on the RTT measurement mechanism, and can use the propagation delay to correct the clock synchronization error, which is beneficial to improving the timing accuracy.

[0058] In a possible implementation, before sending the first message to the first terminal device, the method further includes:

[0059] receiving a direct communication request from a first terminal device; the direct communication request including an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service is required by establishing a direct link;

[0060] Sending a first message to a first terminal device includes:

[0061] When it is determined that the identifier of the at least one target terminal device includes the identifier of the second terminal device, a first message is sent to the first terminal device.

[0062] In this implementation, when the second terminal device determines that the identifier of at least one target terminal device includes its own identifier, it can send an acceptance message of the direct communication request to the first terminal device, thereby establishing a direct link with the first terminal device, and can report the timing mode supported by itself to the first terminal device to assist the first terminal device in deciding a reasonable timing mode for timing the second terminal device based on the timing modes supported by both.

[0063] In a possible implementation, before sending the first message to the first terminal device, the method further includes:

[0064] receiving a direct communication request from a first terminal device; the direct communication request including an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service is required by establishing a direct link;

[0065] Sending a first message to a first terminal device includes:

[0066] When it is determined that the identifier of the second terminal device is not included in the identifier of the at least one target terminal device and the ProSe timing service is required, a first message is sent to the first terminal device.

[0067] In this implementation, when the second terminal device determines that the identifier of at least one target terminal device does not include its own identifier and ProSe timing service is required, it can send an acceptance message of the direct communication request to the first terminal device, thereby establishing a direct link with the first terminal device, and can report the timing mode supported by itself to the first terminal device to assist the first terminal device in deciding a reasonable timing mode for timing the second terminal device based on the timing modes supported by both.

[0068] In a possible implementation, the direct communication request is sent when the path preference corresponding to the ProSe service information is a PC5 interface.

[0069] In this implementation, if the path preference of the ProSe service is the PC5 interface, the first terminal device can initiate the process of establishing a direct link by sending a direct communication request.

[0070] In a possible implementation, the method further includes:

[0071] When it is determined that the direct link with the first terminal device is disconnected, a relay terminal device is determined from the group and a direct link is established with the relay terminal device so that the relay terminal device provides time to the second terminal device after being provided time by the first terminal device.

[0072] In this implementation, when the second terminal device determines that the direct link between it and the first terminal device is disconnected, the second terminal device can find a relay terminal device from the group, so that the relay terminal device can provide time to the second terminal device after being timed by the first terminal device, thereby ensuring the reliability and continuity of time synchronization for the second terminal device to the greatest extent.

[0073] In one possible implementation, the second terminal device is within coverage of the wireless access network; the direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the ProSe service information is a Uu interface, the method further includes:

[0074] Obtaining a second clock deviation from the application layer; the second clock deviation is the clock deviation between the master clock terminal device and the access network device;

[0075] receiving a system information block message sent by an access network device; the system information block message includes second time information of the access network device;

[0076] Performing clock synchronization with a master clock terminal device of the group based on the second clock deviation and the second time information;

[0077] or,

[0078] Sending a second message to the application function network element; the second message is used to request the access network device to provide timing for the second terminal device;

[0079] receiving a second unicast message and a broadcast message sent by the access network device; the second unicast message includes a second clock deviation; the second clock deviation is a clock deviation between the master clock terminal device and the access network device; the broadcast message includes second time information of the access network device; the second clock deviation is obtained by the access network device from the unified data management network element;

[0080] Based on the second clock deviation and the second time information, clock synchronization is performed with the master clock terminal device of the group to which it belongs.

[0081] In one possible implementation, the second message includes an identifier of the second terminal device and a group identifier; the identifier of the second terminal device is used to identify the terminal device requesting time synchronization from the access network device; the group identifier is used to indicate that the second terminal device needs to obtain the clock deviation between the group's master clock time and the time of the access network device.

[0082] In this implementation, if the direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with the terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the timing service in the ProSe service is the Uu interface, then the second terminal device can obtain the clock deviation (i.e., the second clock deviation) between the master clock terminal device of the group to which it belongs and the access network device from the application layer, and can obtain the time information of the access network device (i.e., the second time information) through the SIB message sent by the access network device, so that it can use the second clock deviation and the second time information to synchronize the clock with the master clock terminal device of the group to which it belongs, thereby ensuring the reliability and continuity of the timing for the second terminal device. Alternatively, the second terminal device can send a timing request (i.e., a second message) to the core network side, and can add its own identifier and group identifier in the timing request to request the access network device to send the second clock deviation and the second time information, so that it can use the second clock deviation and the second time information to synchronize the clock with the master clock terminal device of the group to which it belongs, thereby ensuring the reliability and continuity of the timing for the second terminal device. Obtaining the clock deviation between the master clock terminal device and the access network device from the application layer helps save signaling overhead compared to transmitting the clock deviation through unicast messages / encrypted broadcasts.

[0083] In a possible implementation, the second unicast message further includes a group identifier; the group identifier is used to indicate that the second clock deviation is a clock deviation between a master clock time of the group and a time of the access network device.

[0084] In this implementation, the second terminal device can determine the second clock deviation as the clock deviation between the master clock time of the group to which it belongs and the time of the access network device based on the group identifier in the second unicast message, thereby facilitating the use of the second clock deviation to synchronize the clock with the master clock terminal device of the group to which it belongs.

[0085] In a third aspect, an embodiment of the present application provides a timing method, applied to an access network device; the method includes:

[0086] Obtaining a second clock deviation from a master clock terminal device of a group to which the second terminal device belongs;

[0087] Sending the second clock deviation to the first terminal device, so that the first terminal device uploads the second clock deviation to the application layer; or,

[0088] The second clock deviation is sent to the unified data management network element for storage.

[0089] The second clock deviation is used to provide timing for the second terminal device when the direct link between the second terminal device and the first terminal device is disconnected or the second terminal device only supports base station timing.

[0090] It can be seen that in an embodiment of the present application, the access network device can send the second clock deviation of the master clock terminal device of the group to which the second terminal device belongs to the first terminal device, so that the first terminal device sends it to the application layer, and can also store it in the unified data management network element, so that when the direct link between the second terminal device and the first terminal device is disconnected or the second terminal device only supports base station timing or the path preference corresponding to the ProSe service information is the Uu interface, the second terminal device can obtain the second clock deviation from the application layer or send the second clock deviation through the access network device, thereby ensuring that the second terminal device can synchronize the clock with the master clock terminal device of the group to which it belongs through the access network device, thereby ensuring the reliability and continuity of timing for the second terminal device.

[0091] In a possible implementation, sending the second clock offset to the unified data management network element for storage includes:

[0092] sending the second clock deviation to the access and mobility management function network element, so that the access and mobility management function network element sends the second clock deviation to the unified data management network element for storage; or,

[0093] The second clock deviation is sent to the time-sensitive communication and time synchronization function network element, so that the time-sensitive communication and time synchronization function network element sends the second clock deviation to the unified data management network element for storage.

[0094] In this implementation, the access network device can store the second clock deviation in the unified data management network element through the access and mobility management function network element or the time-sensitive communication and time synchronization function network element, so that when the second terminal device requests the access network device for time synchronization, the access network device can obtain the second clock deviation from the unified data management network element and send it to the second terminal device.

[0095] In a possible implementation, the method further includes:

[0096] Receive a third message sent by the access and mobility management function network element; the third message includes an identifier of the second terminal device and a group identifier of the group to which the second terminal device belongs; the identifier of the second terminal device is used to identify the terminal device requesting timing of the access network device; the group identifier is used to indicate that the second terminal device needs to obtain the clock deviation between the master clock time of the group and the time of the access network device; the second terminal device is within the coverage of the wireless access network; the direct link between the second terminal device and the first terminal device is disconnected, and a direct link cannot be established with the terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the ProSe service information is the Uu interface;

[0097] Obtaining a second clock offset from a unified data management network element based on the group identifier;

[0098] Sending a second unicast message to the second terminal device; the second unicast message includes a second clock deviation and a group identifier; the group identifier is used to indicate that the second clock deviation is a clock deviation between the master clock time of the group and the time of the access network device;

[0099] Send a broadcast message; the broadcast message includes the second time information of the access network device.

[0100] In this implementation method, when the second terminal device requests time synchronization, the access network device can obtain the second clock deviation from the unified data management network element based on the group identifier in the third message sent by the core network side, and send the second clock deviation and its own time information (i.e., the second time information) to the second terminal device, so that the second terminal device can use the second clock deviation and the second time information to synchronize the clock with the master clock terminal device of the group to which it belongs, thereby ensuring the reliability and continuity of time synchronization for the second terminal device.

[0101] In one possible implementation, the third message is sent by the access and mobility management function network element when the time-sensitive communication and time synchronization function network element confirms that the second message sent by the second terminal device to the application function network element is valid; the second message is used to request that the access network device be enabled to provide time synchronization for the second terminal device.

[0102] In this implementation, when the core network side determines that the timing request sent by the second terminal device is valid, the access network device will receive the third message sent by the core network side, thereby providing time for the second terminal device, thereby ensuring the reliability of the timing of the second terminal device.

[0103] In a possible implementation, the second clock deviation is obtained by the access network device and the master clock terminal device based on an RTT measurement mechanism.

[0104] In this implementation, the access network device and the master clock terminal device can obtain the clock deviation between the two through the RTT measurement mechanism, and can store the clock deviation in a unified data management network element, or send it to the first terminal device and upload it to the application layer to facilitate time synchronization for the second terminal device.

[0105] In a fourth aspect, an embodiment of the present application provides a timing device, applied to a first terminal device; the device includes a first transceiver unit and a first processing unit;

[0106] A first transceiver unit is configured to receive a first message from a second terminal device; the first message includes a timing mode supported by the second terminal device;

[0107] The first processing unit is used to provide time service for the second terminal device based on the time service mode supported by the second terminal device.

[0108] In one possible implementation, the timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing, and base station timing;

[0109] The timing modes supported by the first terminal device include one or more of broadcast timing, unicast timing, PTP timing and base station timing.

[0110] In one possible implementation, in providing time to the second terminal device based on a time service mode supported by the second terminal device, the first processing unit is specifically configured to:

[0111] Determine the timing mode for the second terminal device to perform timing based on the timing mode supported by the terminal device and the timing mode supported by the second terminal device;

[0112] The second terminal device is provided with time service based on the determined time service method.

[0113] In one possible implementation, in providing time to the second terminal device based on a time service mode supported by the second terminal device, the first processing unit is specifically configured to:

[0114] If the determined timing mode is PTP timing, instruct the first transceiver unit to send a PTP message to the second terminal device through the direct link between the first transceiver unit and the second terminal device;

[0115] Among them, the PTP message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the first clock deviation after obtaining the first clock deviation from the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0116] In one possible implementation, in providing time to the second terminal device based on a time service mode supported by the second terminal device, the first processing unit is specifically configured to:

[0117] If the determined timing mode is broadcast timing, instructing the first transceiver unit to send a sidelink broadcast message;

[0118] If the determined timing mode is unicast timing, instructing the first transceiver unit to send a first unicast message to the second terminal device through the direct link between the first transceiver unit and the second terminal device;

[0119] Among them, the sidelink broadcast message or the first unicast message includes the first time information and the group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0120] In a possible implementation, the propagation delay is obtained by the first terminal device and the second terminal device based on an RTT measurement mechanism.

[0121] In a possible implementation, the first transceiver unit is further configured to:

[0122] Sending a direct communication request to the second terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that ProSe timing service needs to be performed by establishing a direct link;

[0123] The first message is sent when the second terminal device determines that the identifier of at least one target terminal device includes the identifier of the second terminal device.

[0124] In a possible implementation, the first transceiver unit is further configured to:

[0125] Sending a direct communication request to the second terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that ProSe timing service needs to be performed by establishing a direct link;

[0126] The first message is sent when the second terminal device determines that the identifier of at least one target terminal device does not include the identifier of the second terminal device and ProSe timing service is required.

[0127] In a possible implementation, the direct communication request is sent when the path preference corresponding to the ProSe service information is a PC5 interface.

[0128] In a possible implementation, the first transceiver unit is further configured to:

[0129] Receive a second clock deviation sent by the access network device; the second clock deviation is the clock deviation between the master clock terminal device and the access network device;

[0130] Upload the second clock offset to the application layer; or,

[0131] The second clock deviation is sent to the unified data management network element for storage.

[0132] It should be understood that since the method embodiment and the device embodiment are different presentation forms of the same technical concept, the content of the first aspect of the embodiment of the present application should be synchronously adapted to the fourth aspect of the embodiment of the present application, and can achieve the same or similar beneficial effects, and will not be repeated here.

[0133] In a fifth aspect, an embodiment of the present application provides a timing device, applied to a second terminal device; the device includes a second transceiver unit;

[0134] The second transceiver unit is used to send a first message to the first terminal device; the first message includes the timing mode supported by the second terminal device; the timing mode supported by the second terminal device is used by the first terminal device to provide time to the second terminal device.

[0135] In one possible implementation, the timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing, and base station timing;

[0136] The timing modes supported by the first terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing and base station timing.

[0137] In a possible implementation, the second transceiver unit is further configured to:

[0138] Receiving a PTP message sent by the first terminal device through a direct link between the first terminal device and the second terminal device;

[0139] Among them, the PTP message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the first clock deviation after obtaining the first clock deviation from the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0140] In a possible implementation, the second transceiver unit is further configured to:

[0141] receiving at least one sidelink broadcast message; wherein the at least one sidelink broadcast message includes a sidelink broadcast message sent by a first terminal device; the sidelink broadcast message sent by the first terminal device includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of a group to which the second terminal device belongs; the first time information is used by the second terminal device to perform clock synchronization based on the first time information and the propagation delay after obtaining a propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is a master clock time of the group; or,

[0142] Receive a first unicast message sent by a first terminal device through a direct link between the first terminal device and the second terminal device; wherein the first unicast message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of the group to which the second terminal device belongs; the first time information is used by the second terminal device to synchronize its clock based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0143] In a possible implementation, the propagation delay is obtained by the first terminal device and the second terminal device based on an RTT measurement mechanism.

[0144] In a possible implementation, the second transceiver unit is further configured to:

[0145] receiving a direct communication request from a first terminal device; the direct communication request including an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service is required by establishing a direct link;

[0146] In terms of sending an acceptance message of the direct communication request to the first terminal device, the second transceiver unit is specifically configured to:

[0147] When it is determined that the identifier of the at least one target terminal device includes the identifier of the second terminal device, an acceptance message for the direct communication request is sent to the first terminal device.

[0148] In a possible implementation, the second transceiver unit is further configured to:

[0149] receiving a direct communication request from a first terminal device; the direct communication request including an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service is required by establishing a direct link;

[0150] In terms of sending an acceptance message of the direct communication request to the first terminal device, the second transceiver unit is specifically configured to:

[0151] When it is determined that the identifier of the at least one target terminal device does not include the identifier of the second terminal device and the ProSe timing service is required, an acceptance message for the direct communication request is sent to the first terminal device.

[0152] In a possible implementation, the direct communication request is sent when the path preference corresponding to the ProSe service information is a PC5 interface.

[0153] In a possible implementation, the apparatus further includes a second processing unit;

[0154] The second processing unit is used to determine the relay terminal device from the group and establish a direct link with the relay terminal device when it is determined that the direct link between the relay terminal device and the first terminal device is disconnected, so that the relay terminal device can provide time for the second terminal device after being provided time by the first terminal device.

[0155] In one possible implementation, the apparatus further includes a second processing unit; the second terminal device is within coverage of the wireless access network; and when a direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the ProSe service information is a Uu interface:

[0156] The second processing unit is configured to obtain a second clock deviation from the application layer; the second clock deviation is a clock deviation between the master clock terminal device and the access network device;

[0157] The second transceiver unit is further configured to receive a system information block message sent by the access network device; the system information block message includes second time information of the access network device;

[0158] The second processing unit is further configured to perform clock synchronization with a master clock terminal device of the group to which it belongs based on the second clock deviation and the second time information;

[0159] or,

[0160] The second transceiver unit is further configured to send a second message to the application function network element; the second message is used to request that the access network device be enabled to provide time synchronization for the second terminal device; receive a second unicast message and a broadcast message sent by the access network device; the second unicast message includes a second clock deviation; the second clock deviation is a clock deviation between the master clock terminal device and the access network device; the broadcast message includes second time information of the access network device; the second clock deviation is obtained by the access network device from the unified data management network element;

[0161] The second processing unit is configured to perform clock synchronization with the master clock terminal device of the group to which it belongs based on the second clock deviation and the second time information.

[0162] In one possible implementation, the second message includes an identifier of the second terminal device and a group identifier; the identifier of the second terminal device is used to identify the terminal device requesting time synchronization from the access network device; the group identifier is used to indicate that the second terminal device needs to obtain the clock deviation between the group's master clock time and the time of the access network device.

[0163] In a possible implementation, the second unicast message further includes a group identifier; the group identifier is used to indicate that the second clock deviation is a clock deviation between a master clock time of the group and a time of the access network device.

[0164] It should be understood that since the method embodiment and the device embodiment are different presentation forms of the same technical concept, the content of the second aspect of the embodiment of the present application should be synchronously adapted to the fifth aspect of the embodiment of the present application, and can achieve the same or similar beneficial effects, and will not be repeated here.

[0165] In a sixth aspect, an embodiment of the present application provides a timing device, applied to an access network device; the device includes a third transceiver unit and a third processing unit;

[0166] a third processing unit, configured to obtain a second clock deviation from a master clock terminal device of a group to which the second terminal device belongs;

[0167] The third transceiver unit is used to send the second clock deviation to the first terminal device, so that the first terminal device uploads the second clock deviation to the application layer; or send the second clock deviation to the unified data management network element for storage.

[0168] In a possible implementation, in terms of sending the second clock deviation to the unified data management network element for storage, the third transceiver unit is specifically configured to:

[0169] sending the second clock deviation to the access and mobility management function network element, so that the access and mobility management function network element sends the second clock deviation to the unified data management network element for storage; or,

[0170] The second clock deviation is sent to the time-sensitive communication and time synchronization function network element, so that the time-sensitive communication and time synchronization function network element sends the second clock deviation to the unified data management network element for storage.

[0171] In a possible implementation, the third transceiver unit is further configured to:

[0172] Receive a third message sent by the access and mobility management function network element; the third message includes an identifier of the second terminal device and a group identifier of the group to which the second terminal device belongs; the identifier of the second terminal device is used to identify the terminal device requesting time synchronization from the access network device; the group identifier is used to indicate that the second terminal device needs to obtain the clock deviation between the master clock time of the group and the time of the access network device; the second terminal device is within the coverage of the wireless access network; the direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with the terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the ProSe service information is the Uu interface;

[0173] Obtaining a second clock offset from a unified data management network element based on the group identifier;

[0174] Sending a second unicast message to the second terminal device; the second unicast message includes a second clock deviation and a group identifier; the group identifier is used to indicate that the second clock deviation is a clock deviation between the master clock time of the group and the time of the access network device;

[0175] Send a broadcast message; the broadcast message includes the second time information of the access network device.

[0176] In one possible implementation, the third message is sent by the access and mobility management function network element when the time-sensitive communication and time synchronization function network element confirms that the second message sent by the second terminal device to the application function network element is valid; the second message is used to request that the access network device be enabled to provide time synchronization for the second terminal device.

[0177] In a possible implementation, the second clock deviation is obtained by the access network device and the master clock terminal device based on an RTT measurement mechanism.

[0178] It should be understood that since the method embodiment and the device embodiment are different presentation forms of the same technical concept, the content of the third aspect of the embodiment of the present application should be synchronously adapted to the sixth aspect of the embodiment of the present application, and can achieve the same or similar beneficial effects, and will not be repeated here.

[0179] In the seventh aspect, an embodiment of the present application provides an electronic device, comprising a processor, a memory, a communication interface, and one or more programs, wherein the one or more programs are stored in the memory and are configured to, when executed by the processor, cooperate with the communication interface to implement the method in any one of the embodiments of the first, second or third aspects above.

[0180] In an eighth aspect, an embodiment of the present application provides a chip, comprising: a processor for calling and running a computer program from a memory, so that a device equipped with the chip executes a method in any one of the embodiments of the first, second or third aspects above.

[0181] In the ninth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program for execution by a device, and when the computer program is executed, it implements the method in any one of the embodiments of the first, second or third aspects mentioned above.

[0182] In the tenth aspect, an embodiment of the present application provides a computer program product. When the computer program product is run by a device, the device executes a method in any one of the embodiments of the first aspect, the second aspect, or the third aspect mentioned above. BRIEF DESCRIPTION OF THE DRAWINGS

[0183] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0184] FIG1 is a schematic diagram of a related art in which multiple robots collaborate online to construct a map;

[0185] FIG2 is a schematic diagram of clock synchronization error compensation provided by a related art;

[0186] FIG3 is a schematic diagram of clock synchronization error compensation provided by another related technology;

[0187] FIG4 is a schematic diagram of a process flow of group timing provided by a related technology;

[0188] FIG5 is a schematic diagram of problems existing in the related art;

[0189] FIG6 is a schematic diagram of a network system architecture provided in an embodiment of the present application;

[0190] FIG7 is a flow chart of a timing method according to an embodiment of the present application;

[0191] FIG7A is a flow chart of another timing method provided in an embodiment of the present application;

[0192] FIG7B is a flow chart of another timing method provided in an embodiment of the present application;

[0193] FIG7C is a flow chart of another timing method provided in an embodiment of the present application;

[0194] FIG7D is a flow chart of another timing method provided in an embodiment of the present application;

[0195] FIG8 is a schematic diagram of a process for obtaining a propagation delay between terminal devices according to an embodiment of the present application;

[0196] FIG9 is a schematic diagram of a process for obtaining and storing clock deviations between a master clock terminal device and an access network device according to an embodiment of the present application;

[0197] FIG9A is a flow chart of another timing method provided in an embodiment of the present application;

[0198] FIG9B is a flow chart of another timing method provided in an embodiment of the present application;

[0199] FIG10 is a schematic diagram of a process for a core network to process a timing request of a terminal device according to an embodiment of the present application;

[0200] FIG11 is a flow chart of another timing method provided in an embodiment of the present application;

[0201] FIG12 is a schematic diagram of the overall flow of a timing method provided in an embodiment of the present application;

[0202] FIG13 is a flow chart of another timing method provided in an embodiment of the present application;

[0203] FIG14 is a flow chart of another timing method provided in an embodiment of the present application;

[0204] FIG15 is a schematic diagram of the overall flow of another timing method provided in an embodiment of the present application;

[0205] FIG16 is a flow chart of another timing method provided in an embodiment of the present application;

[0206] FIG17 is a schematic diagram of the overall flow of another timing method provided in an embodiment of the present application;

[0207] FIG18 is a schematic structural diagram of a timing device provided in an embodiment of the present application;

[0208] FIG19 is a schematic structural diagram of another timing device provided in an embodiment of the present application;

[0209] FIG20 is a schematic structural diagram of another timing device provided in an embodiment of the present application;

[0210] FIG21 is a schematic structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0211] The terms "first," "second," "third," and "fourth," etc., in the specification and claims of this application and the accompanying drawings are used to distinguish different objects, not to describe a specific order. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0212] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0213] As used in this specification, the terms "component", "module", "system", etc. are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program and / or a computer. By way of illustration, both an application running on a terminal device and a terminal device can be a component. One or more components can reside in a process and / or an execution thread, and a component can be located on a computer and / or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can communicate, for example, through local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system and / or a network, such as the Internet interacting with other systems via signals).

[0214] First, a brief introduction to the relevant terms and related technical background in this application is given to facilitate understanding by those skilled in the art.

[0215] 3rd Generation Partnership Project: 3GPP;

[0216] 5G Core Network: 5G Core Network, 5GC;

[0217] 5G system: 5G System, 5GS;

[0218] Operations, Administration and Management: QAM;

[0219] 5G base station: gNodeB, gNB;

[0220] Data Network: Data Network, DN;

[0221] Generic Public Subscription Identifier: Generic Public Subscription Identifier, GPSI;

[0222] Radio Access Network: RAN;

[0223] Next Generation Radio Access Network / 5G Radio Access Network: Next Generation Radio Access Network, NG-RAN;

[0224] Subscription Permanent Identifier (SUPI)

[0225] Uplink / Downlink: Up link / Down link, UL / DL;

[0226] Timing advance: Timing advance, TA;

[0227] Round-trip time: RTT;

[0228] Quality of service: Quality of service, QoS;

[0229] Propagation delay compensation: Propagation delay compensation, PDC;

[0230] Tracking reference signal: Tracking reference signal, TRS;

[0231] Channel detection signal: Sounding reference signal, SRS;

[0232] Positioning reference signal: Positioning reference signal, PRS;

[0233] End-to-end: Endtoend, E2E;

[0234] Reference signal: Reference signal, RS;

[0235] Precision Time Protocol: precise time protocol, PTP; a high-precision time synchronization protocol.

[0236] One related technology proposes a scenario in which multiple robots collaborate online to build a three-dimensional (3D) map. In this scenario, multiple robots within a defined area form a group. The robots are equipped with multi-dimensional environmental sensing, computing (independently and / or through computing structures), learning, model building, and communication based on 3GPP subscriptions. This scenario is illustrated in Figure 1. Before starting a business process, the multiple robots must select a leader UE (leader UE) and member UEs (member UEs), and the leader UE's clock is designated as the master clock. The leader UE is responsible for collecting data measured by other UEs and initializing the process. All UEs in the group transmit their capabilities (communication layer and battery information, etc.) to each other. To ensure that member UEs in the group can simultaneously upload data to the leader UE, group clock synchronization is required. The leader UE, acting as the master clock, synchronizes its time information to all member UEs in the group. All member UEs perform data measurements, begin moving, and collect measurement data. The member UEs synchronously upload the measurement data to the leader UE. Finally, the leader UE further processes all measurement data at that moment to generate a comprehensive 3D map. The scenario shown in Figure 1 requires that when some robots perform Proximity Services (ProSe)-based operations outside the coverage of NG-RAN services, 5GS can ensure that clock synchronization is timely, complete, and effective within the specified time.

[0237] The second related technology proposes compensation for clock synchronization error. It should be understood that the time synchronization error between the gNB and the UE primarily comes from downlink propagation delay, which can be compensated using PDC technology. Currently, common PDC technologies include TA-based PDC and RTT-based PDC. The implementation of TA-based PDC is shown in Figure 2. The gNB sends a downlink measurement message to the UE. After receiving the downlink measurement message, the UE sends an uplink message to the gNB. The gNB obtains the TA value based on this uplink message and sends it to the UE via TA signaling. The UE adjusts its timing information based on the TA value in the TA signaling to obtain more accurate time information, thereby improving timing accuracy. The implementation of RTT-based PDC is shown in Figure 3. The side performing time compensation must wait for DL ​​RS, UL RS, and receive (Rx)-transmit (Tx) measurements before obtaining the propagation delay. Both the gNB and the UE have the ability to perform time correction by measuring the Rx-Tx time difference of the other party. PDC technology improves timing accuracy by estimating propagation delay and making pre-compensation. In TA-based PDC, only the base station can obtain the compensated TA value. However, for RTT-based PDC, both the base station and the UE can calculate the compensation value and perform clock correction themselves. Therefore, if PDC is performed between two UEs, only RTT-based PDC can be used.

[0238] The third related technology provides a process for 5GC to perform group timing. In the local dynamic collaboration of the production line in the 5G industrial scenario, 5GC achieves clock synchronization of industrial equipment in the dynamic collaboration group through the process shown in Figure 4. Among them:

[0239] 1a: The Application Function (AF) NE sends Nnef_ASTI_Create_Req to the Network Exposure Function (NEF) NE to create a group based on service requirements. The request includes group member information (UE list), the identifier (ID) of the master clock UE, such as SUPI, GPSI, etc., the group ID (optional; such as External Group Identifier, etc.), and the timing error (optional; such as E2E time synchronization error budget);

[0240] 1b: When NEF receives the timing request from AF, it authenticates it. The authenticated AF timing request further sends Ntsctsf_ASTI_Create_Req to the Time Sensitive Communication and Time Synchronization Function (TSCTSF) network element. At this time, NEF may map the external group ID of the AF request to the 5GC group ID.

[0241] 1c: The NEF NE stores group information to the Unified Data Management (UDM) NE via Nudm_groupinfo_Create_Req / Resp. The information includes group member information, master clock UE, group ID (optional), which can be a mapped 5GC group ID, and E2E time synchronization error budget (optional).

[0242] 2: After receiving the timing request from the AF network element, the TSCTSF network element obtains the subscription data of the group members from the UDM network element through Nudm_SDM_Get to determine whether the timing service requested by the AF network element is allowed;

[0243] 3a: The TSCTSF network element initiates the AM policy for group timing to the Policy Control Function (PCF) network element through Npcf_AMPolicyAuthorization_Create_Req. This policy includes the timing UE list, the group ID of the group to which the timing UE belongs, the master clock UE, and the air interface timing error (Uutimesynchronizationerrorbudget) obtained by the TSCTSF network element through pre-configuration or E2E timesynchronizationerrorbudget.

[0244] 3b: The PCF network element provides the AM policy to the Access and Mobility Management Function (AMF) network element;

[0245] 3c: After the AM Policy, the PCF network element responds to the request of the TSCTSF network element through Npcf_AMPolicyAuthorization_Create_Resp;

[0246] 4: The TSCTSF network element responds to the request initiated by the NEF network element through Ntsctsf_ASTI_Create_Resp, and the NEF network element responds to the timing request initiated by the AF network element;

[0247] 5a: The AMF network element sends an N2 message to the RAN, including the timing object (UE list), the group to which it belongs, the master clock UE, and the requirements for air interface timing error;

[0248] 5b: RAN calculates the clock offset between it and the master clock UE;

[0249] 5c (optional): After the RAN calculation is completed, the calculated offset is sent to the AMF network element / TSCTSF network element, which can be stored in the UDM network element;

[0250] 5d: RAN provides timing to group members (UE1 and UE2). The specific solution can be:

[0251] (1) When PDC is not used, the RAN uses unicast Radio Resource Control (RRC) to synchronize the timing of group members. The corresponding group members add an offset to synchronize their clocks. The offset can be compensated when the RAN sends the RRC, or sent along with the RRC signaling. In this case, the UE compensates for the offset.

[0252] (2) When performing PDC, the RAN synchronizes the timing of group members using unicast RRC. After the RAN calculates the offset for each group member, it adds the offset of the current group granularity to the group members. These two offsets can be sent separately or combined into a total clock offset.

[0253] (3) When PDC is not used, the RAN uses broadcast timing to synchronize timing. In this case, the RAN needs to first send the key to all members in the group using RRC unicast, and then send the group-granular offset using broadcast encryption. Alternatively, the RAN can directly encrypt the time t of the master clock UE plus the offset, for example, t + offset.

[0254] (4) When performing PDC, the RAN uses broadcast timing. When the RAN calculates the TA for each UE, it needs to send the TA in unicast mode. For group members, the RAN adds an offset when sending the TA. The TA and offset can be two values, such as: TA, offset; or they can be one value, such as: TA+offset.

[0255] After research, it was found that the relevant technologies have the following defects or deficiencies: (1) When there are UEs in the group that are intermittently connected to the NG-RAN, the UE can only communicate through ProSe when it is disconnected from the NG-RAN. However, in the current ProSe communication, frame alignment can only be performed through the direct link synchronization signal (Sidelink Synchronization Signal, SLSS). The UE cannot transmit absolute time information through the sidelink broadcast / unicast. In other words, it is difficult for the UE to use ProSe for timing, as shown in Problem 1 in Figure 5. (2) In the group timing scenario, if the UE hardware conditions can support multiple timing methods, such as PTP timing, broadcast / unicast timing, it is difficult for the timing device to determine which timing method to use for timing, and the reliability of timing cannot be fully guaranteed. (3) When the direct link between the member UE and the leader UE in the group is disconnected, the member UE cannot guarantee that it can still synchronize its clock with the leader UE, that is, the continuity of timing cannot be guaranteed, as shown in Problem 2 in Figure 5. (4) The method of transmitting the master clock time through the base station requires sending unicast messages or encrypted broadcast messages to the UEs in the group. However, in either method, the base station needs to send unicast messages to all member UEs in the group (if encrypted broadcast messages are used, a key needs to be unicast to all member UEs in the group to ensure that the time sent to the UE is the corresponding group time), resulting in a waste of signaling resources. At the same time, if the member UE switches from the leader UE timing to the base station timing, the base station cannot actively perceive the current timing status of the member UE and cannot trigger the base station to unicast the time or key to the member UE.

[0256] In order to overcome the defects and shortcomings of the prior art, an embodiment of the present application provides a timing method to transmit absolute time information when using ProSe, thereby realizing clock synchronization between UEs using ProSe. In addition, for UEs that are intermittently connected to NG-RAN, they can switch the timing link to ensure the continuity of their own timing. Please refer to Figure 6. The timing method can be implemented based on the network system architecture shown in Figure 6. As shown in Figure 6, the system architecture may include UE, RAN equipment, TSC TSF network element, AF network element, NEF network element, PCF network element, AMF network element, Binding Support Function (BSF) network element, UDM network element, Unified Data Repository (UDR) network element, OAM network element, Network Function Repository Function (NRF) network element, User Plane Function (UPF) network element, Data Network (DN) network element, Session Management Function (SMF) network element, etc.

[0257] UE includes but is not limited to: user equipment, user unit, user station, mobile station, mobile station, remote station, remote terminal equipment, mobile terminal equipment, user terminal equipment, wireless electronic device, user agent, user device, cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication function, computing device, processing device connected to a wireless modem, vehicle-mounted device, wearable device, terminal device in the Internet of Things, home appliances, virtual reality device, terminal device in the future 5G network or terminal device in the future evolved public land mobile network (PLMN), etc.

[0258] RAN equipment is primarily responsible for air interface-side functions such as radio resource management, quality of service (QoS) management, data compression, and encryption. RAN equipment can include various base stations, such as macro base stations, micro base stations (also known as small cells), relay stations, and access points. In systems using different radio access technologies, the names of devices with base station functionality may vary. For example, in 5GS, they are called gNBs; in LTE systems, they are called evolved NodeBs (eNBs or eNodeBs); and in third-generation (3G) systems, they are called NodeBs. Optionally, in some RAN deployments, RAN equipment can be a centralized unit (CU) or a distributed unit (DU). For example, operations or steps at the Radio Link Control (RLC) layer, Media Access Control (MAC) layer, and Radio Resource Control (RRC) layer may be performed by the CU, while operations or steps at the Physical (PHY) layer may be performed by the DU. In other deployments of RAN devices, the CU can also be divided into CU-control plane (CP) and CU-user plane (UP), etc. In some other deployments of RAN devices, the RAN device can also be an antenna unit (RU). In some other deployments of RAN devices, the RAN device can also be an open radio access network (ORAN) architecture, etc. The embodiments of the present application do not limit the deployment method of the RAN device. For example, when the RAN device is an ORAN architecture, the RAN device shown in the embodiments of the present application can be an access network device in the ORAN, or a module in the access network device, etc. In the ORAN architecture, CU can also be called open (open, O)-CU, DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU.

[0259] The main function of the TSCTSF network element is to associate the clock synchronization service request of the network element consumer with the AF session of the PCF network element; detect the availability of 5GS bridge information of Ethernet and IP type protocol data unit (PDU) sessions reported by the PCF network element, and realize deterministic forwarding management capabilities within the 5G system.

[0260] The AF network element communicates application-side requirements to the network, such as QoS requirements or user status event subscriptions. The AF network element can be a third-party functional entity or an application server deployed by the operator. The UE can send requests to the AF network element to obtain specific applications and services.

[0261] The NEF is responsible for exposing 5G network capabilities and events to the outside world, receiving relevant external information, and allowing third-party applications and services to access and utilize 5G network functions and resources. It is also responsible for handling the security authentication and authorization of third-party applications and services, ensuring that only authorized applications and services can access and utilize 5G network functions and resources.

[0262] The PCF network element is responsible for generating UE access policies and QoS flow control policies. It makes decisions and adjusts network policies based on the network operator's policies and user needs. It dynamically adjusts policy rules based on different scenarios and requirements to meet the needs of different users and applications.

[0263] The AMF network element performs registration, connection, reachability and mobility management, provides a session management message transmission channel for UE and SMF network elements, provides authentication and authorization functions for user access, and is the access point for the terminal and the wireless core network control plane.

[0264] The BSF network element performs service authentication on the consumer network element and sends all service messages of the same user sent from the same interface or different interfaces to the same PCF network element for processing based on the session binding information.

[0265] The UDM network element manages user contracts, authorizes access, and generates authentication information.

[0266] The UDR network element provides storage capabilities for contract data, policy data, and capability exposure-related data.

[0267] NRF network elements enable mutual communication between various network elements.

[0268] The UPF network element is an important part of the 3GPP 5G core network system architecture, and is mainly responsible for the routing and forwarding of user plane data packets in the 5G core network.

[0269] SMF network elements implement IP address allocation and management, policy control, and billing data collection.

[0270] DN network elements provide data-centric services such as the Internet, cloud, and enterprise networks.

[0271] The technical solution provided in this application is introduced in detail below in conjunction with specific implementation methods.

[0272] Please refer to FIG. 7 , which is a flow chart of a timing method provided in an embodiment of the present application. As shown in FIG. 7 , the method may include steps 701-703:

[0273] 701: The second terminal device sends a first message to the first terminal device.

[0274] In an embodiment of the present application, illustratively, the first message includes a timing mode supported by the second terminal device. The timing mode (or timing capability) supported by the second terminal device includes one or more of broadcast timing, unicast timing, PTP timing, and base station timing, and may also include other timing modes. The first message may be actively sent by the second terminal device to the first terminal device, or may be sent by the second terminal device to the first terminal device after receiving a request from the first terminal device. Exemplarily, the second terminal device and the first terminal device may communicate via the PC5 interface.

[0275] In which, the first terminal device and the second terminal device may be two devices capable of direct communication. In some scenarios, the first terminal device and the second terminal device may simply be two terminal devices with communication needs. In other scenarios, the first terminal device and the second terminal device may be two terminal devices with communication needs and belonging to the same group, for example: the first terminal device and the second terminal device both belong to group 1. In still other scenarios, the first terminal device and the second terminal device may be two terminal devices with communication needs but belonging to different groups, for example: the first terminal device belongs to group 1 and the second terminal device belongs to group 2. In still other scenarios, the first terminal device and the second terminal device may have communication needs but only one terminal device has a group, while the other terminal device does not belong to any group, for example: the second terminal device belongs to group 1 and the first terminal device does not belong to any group. Exemplarily, when the first terminal device and the second terminal device belong to the same group, the first terminal device may be a master clock terminal device, such as a leader UE; and the second terminal device may be a slave clock terminal device, such as a member UE.

[0276] 702: The first terminal device receives a first message from the second terminal device.

[0277] 703: The first terminal device provides time to the second terminal device based on the time service mode supported by the second terminal device.

[0278] In an embodiment of the present application, the first terminal device can decide a timing method for the second terminal device based on the timing method sent by the second terminal device, and use the determined timing method to provide time for the second terminal device. For example: the timing methods supported by the second terminal device include broadcast timing, unicast timing, and PTP timing, then the first terminal device can choose any one of them to provide time for the second terminal device.

[0279] Exemplarily, the first terminal device may also provide timing for the second terminal device in combination with the timing mode supported by itself and the timing mode supported by the second terminal device. For example: the timing mode supported by the first terminal device includes one or more of broadcast timing, unicast timing, PTP timing and base station timing, and may also include other timing modes. The first terminal device decides the timing mode for providing timing for the second terminal device based on the timing mode supported by itself and the timing mode supported by the second terminal device. Among them, the timing mode for providing timing for the second terminal device is one of the intersections of the timing mode supported by the first terminal device and the timing mode supported by the second terminal device (that is, one of the timing modes supported by both the first terminal device and the second terminal device). For example: if the timing modes supported by the first terminal device and the second terminal device both include PTP timing, the first terminal device may use the PTP timing mode to provide timing for the second terminal device; if the first terminal device supports PTP timing, broadcast and unicast timing, and the second terminal only supports broadcast and unicast timing, the first terminal device may use the broadcast timing or unicast timing mode to provide timing for the second terminal device.

[0280] In this implementation, when the second terminal device sends the timing mode it supports, the first terminal device can determine the specific timing mode for timing the second terminal device based on the timing mode supported by itself and the timing mode supported by the second terminal device. This is more friendly than directly timing the second terminal device in a negotiated manner.

[0281] Exemplarily, a direct link is established between the first terminal device and the second terminal device, and the first terminal device can provide time to the second terminal device based on the direct link. The direct link refers to a link in which the two terminal devices communicate directly, or a link in which the two terminal devices communicate through another terminal device (i.e., a relay terminal device) without passing through any network node.

[0282] It can be seen that in the embodiment of the present application, the second terminal device can send the timing mode it supports to the first terminal device, so that the first terminal device can provide time to the second terminal device based on the timing mode supported by the second terminal device. The first terminal device and the second terminal device determine the timing mode and perform timing through a negotiation process, so that whether the second terminal device is within the coverage of the wireless access network, the first terminal device can provide time to the second terminal device through ProSe, without having to rely heavily on the access network device for timing, thereby achieving a more reasonable way to provide time to the terminal device, which is conducive to ensuring the reliability and effectiveness of the timing.

[0283] For example, referring to FIG. 7A , in one implementation, after step 702 , the method may include steps 703 a - 703 c:

[0284] 703a: If the timing mode determined by the first terminal device is PTP timing, the first terminal device sends a PTP message to the second terminal device via the direct link between the first terminal device and the second terminal device.

[0285] Among them, the PTP message includes the first time information t1 and the group ID of the group to which the second terminal device belongs; t1 is added by the first terminal device, and t1 is used for the second terminal device to synchronize the clock with the master clock terminal device of the group to which it belongs based on t1 and offset1 after obtaining the first clock deviation offset1 from the first terminal device. t1 can be the master clock time of the group to which the second terminal device belongs; when the first terminal device is the master clock UE, t1 can be the time information of the first terminal device, for example: when the first terminal device and the second terminal device belong to the same group, and the first terminal device is the leader UE. The group ID is used to indicate that t1 is the master clock time of the group, and can uniquely identify the group to which the second terminal device belongs in the system. Exemplarily, offset1 can be obtained by the first terminal device and the second terminal device using a request response mechanism or an end delay mechanism.

[0286] 703b: The second terminal device receives the PTP message and obtains offset1.

[0287] 703c: The second terminal device uses t1 and offset1 to compensate for the clock synchronization error to complete clock synchronization.

[0288] Optionally, as shown in FIG7B , after step 702 and before step 703a, the method may further include step 702a:

[0289] 702a: The first terminal device determines a timing mode for timing the second terminal device based on the timing modes supported by the first terminal device and the timing modes supported by the second terminal device.

[0290] In this implementation, the first terminal device can send the master clock time information (i.e., t1) of the group to which the second terminal device belongs to the second terminal device by multiplexing PTP timing, so that the second terminal device can obtain the clock deviation (i.e., offset1) from the first terminal device through interaction with the first terminal device, and then use the time information sent by the first terminal device and the clock deviation from the first terminal device to synchronize the clock (for example, add t1 to offset1). The PTP message includes the group ID of the group to which the first terminal device and the second terminal device belong, which enhances the PTP message. In addition, based on the direct link with the second terminal device, the first terminal device can transmit time information to the second terminal device, overcoming the defect that absolute time information cannot be transmitted in existing ProSe communications, thereby realizing timing based on ProSe services.

[0291] For example, referring to FIG. 7C , in another implementation, after step 702 , the method may include steps 704 a - 704 c:

[0292] 704a: If the timing mode determined by the first terminal device is broadcast timing, the first terminal device sends a sidelink broadcast message; or if the timing mode determined by the first terminal device is unicast timing, the first terminal device sends a first unicast message to the second terminal device through the direct link between the second terminal device and the second terminal device.

[0293] If the first terminal device sends a sidelink broadcast message, the sidelink broadcast message includes the first time information t1 and the group ID of the group to which the second terminal device belongs. t1 is added by the first terminal device and is used by the second terminal device to synchronize its clock based on the first time information t1 and the propagation delay after obtaining the propagation delay with the first terminal device. t1 can be the master clock time of the group to which the second terminal device belongs. When the first terminal device is a master clock UE, t1 can be the time information of the first terminal device. The group ID is used to indicate that the first time information t1 is the master clock time of the group.

[0294] Among them, if the first terminal device sends a first unicast message, the first unicast message includes t1 and the group ID of the group to which the second terminal device belongs; t1 is added by the first terminal device, and t1 is used for the second terminal device to synchronize the clock based on the first time information t1 and the propagation delay after obtaining the propagation delay with the first terminal device. t1 can be the master clock time of the group to which the second terminal device belongs. When the first terminal device is the master clock UE, t1 can be the time information of the first terminal device. The group ID is used to indicate that the first time information t1 is the master clock time of the group. Exemplarily, the first unicast message can be an RRC unicast message.

[0295] 704b: The second terminal device receives the sidelink broadcast message or the first unicast message and obtains the propagation delay.

[0296] 704c: The second terminal device corrects the clock synchronization error using t1 and the propagation delay to complete clock synchronization.

[0297] Optionally, as shown in FIG7D , after step 702 and before step 704a, the method may further include step 702a:

[0298] 702a: The first terminal device determines a timing mode for timing the second terminal device based on the timing modes supported by the first terminal device and the timing modes supported by the second terminal device.

[0299] In this implementation, the first terminal device can send the master clock time information (i.e., t1) of the group to which the second terminal device belongs to the second terminal device via sidelink broadcast or unicast, so that the second terminal device can synchronize its clock using the time information and propagation delay sent by the first terminal device after obtaining the propagation delay with the first terminal device through interaction with the first terminal device. The sidelink broadcast message or the first unicast message includes the group ID of the group to which the second terminal device belongs, which enhances the sidelink broadcast message or unicast message. Based on the direct link with the second terminal device, the first terminal device can transmit time information to the second terminal device, overcoming the defect that absolute time information cannot be transmitted in existing ProSe communications, thereby realizing time synchronization based on ProSe services.

[0300] In addition, the first terminal device and the second terminal device can obtain the propagation delay between the two based on the RTT measurement mechanism, and can use the propagation delay to correct the clock synchronization error, which is beneficial to improving the timing accuracy.

[0301] For example, as shown in FIG8 , UE1 sends a signal to UE2 and records the sending time T1; UE2 receives the signal and records the receiving time T2; UE2 sends a signal to UE1 and records the sending time T3; UE1 receives the signal and records the receiving time T4; UE1 performs Rx-Tx time difference measurement and sends an Rx-Tx time difference measurement report to UE2, which includes T1 and T4. UE2 can then calculate the propagation delay based on T2, T3, and the Rx-Tx time difference sent by the UE (i.e., T4-T1):

[0302] T2-T1=delay+offset;

[0303] T4-T3=delay-offset;

[0304] delay=[(T2-T1)+(T4-T3)] / 2;

[0305] Delay represents the propagation delay between UE1 and UE2, and offset represents the clock deviation between UE1 and UE2. UE1 can be the first terminal device, and UE2 can be the second terminal device. The second terminal device can use t1 and delay to correct the clock synchronization error (t1 + delay), ultimately completing clock synchronization.

[0306] In this implementation, the first terminal device and the second terminal device can obtain the propagation delay between the two based on the RTT measurement mechanism, and can use the propagation delay to correct the clock synchronization error, which is beneficial to improving the timing accuracy.

[0307] For example, referring to FIG9 , the timing method provided in this application may further include the following steps:

[0308] 705: The access network device and the master clock terminal device of the group to which the second terminal device belongs obtain a second clock offset offset2 between the two through an RTT measurement mechanism.

[0309] For example, an access network device can send a downlink message to a master clock terminal device and record the sending time s1. After receiving the downlink message, the master clock terminal device records the receiving time s2. It then transmits an uplink message to the access network device, which includes the sending time s3. The access network device records the receiving time s4. The access network device can then calculate offset2 based on s1, s2, s3, and s4:

[0310] s2-s1=delay+offset2;

[0311] s4-s3=delay-offset2;

[0312] offset2=1 / 2[(s2-s1)-(s4-s3)];

[0313] Wherein, delay represents the propagation delay between the access network device and the master clock terminal device. In some exemplary embodiments, the master clock terminal device may be the first terminal device.

[0314] 706a: The access network device sends offset2 to the first terminal device. Or,

[0315] 706b: The access network device sends offset2 to the UDM network element for storage.

[0316] Exemplarily, the first terminal device may be the master clock terminal device of the group to which the second terminal device belongs. Exemplarily, in terms of sending offset2 to the UDM network element, the access network device may send an N2 message to the AMF network element, the N2 message including offset2, the AMF network element sends offset2, the ID of the first terminal device, and the group ID of the group to which the first terminal device and the second terminal device belong to the UDM network element, that is, the offset2 is sent to the UDM network element through the AMF network element for storage. Alternatively, the access network device may also send offset2 to the TSCTSF network element, the TSCTSF network element sends a UE information update message to the UDM network element, the UE information update message including offset2 and the group ID of the group to which the first terminal device and the second terminal device belong, that is, the offset2 is sent to the UDM network element through the TSCTSF network element for storage.

[0317] In this implementation, the access network device can store the second clock deviation in the unified data management network element through the access and mobility management function network element or the time-sensitive communication and time synchronization function network element, so that when the second terminal device requests the access network device for time synchronization, the access network device can obtain the second clock deviation from the unified data management network element and send it to the second terminal device.

[0318] 707a: The first terminal device uploads offset2 to the application layer. Or,

[0319] 707b: The first terminal device sends offset2 to the UDM network element for storage.

[0320] For example, in terms of sending offset2 to the UDM network element, the first terminal device can send a non-access-stratum (NAS) message to the AMF network element through the access network device. The NAS message includes offset2. The AMF network element can send offset2, the ID of the first terminal device, and the group ID of the group to which the first terminal device and the second terminal device belong to the UDM network element. That is, the first terminal device can also send offset2 to the UDM network element through the AMF network element for storage.

[0321] In this implementation, the access network device can send the second clock deviation from the master clock terminal device to the first terminal device so that the first terminal device sends it to the application layer, and can also store it in the unified data management network element, so that when the direct link between the second terminal device and the first terminal device is disconnected or the second terminal device only supports base station timing or the path preference corresponding to the timing service in the ProSe service is the Uu interface, the second terminal device can obtain the second clock deviation from the application layer or send the second clock deviation through the access network device, thereby ensuring that the second terminal device can synchronize the clock with the master clock terminal device of the group to which it belongs through the access network device, thereby ensuring the reliability and continuity of timing for the second terminal device.

[0322] Please refer to FIG. 9A , which is a flow chart of another timing method provided in an embodiment of the present application. As shown in FIG. 9A , based on the embodiment shown in FIG. 9 , the method may further include steps 708 a - 708 e:

[0323] 708a: The second terminal device sends a first message to the first terminal device.

[0324] The first message includes the timing mode supported by the second terminal device, and the timing mode supported by the second terminal device is used by the first terminal device to provide time to the second terminal device.

[0325] If the second terminal device is within the RAN coverage area and the second terminal device only supports base station timing or the path preference corresponding to the ProSe service information is the Uu interface, the second terminal device can switch to timing by the access network device (for example, if the timing message of the first terminal device is not received):

[0326] 708b: The second terminal device obtains offset2 from the application layer.

[0327] 708c: The access network device sends a system information block message.

[0328] The system information block (SIB) message may be a SIB9 message, which is broadcast by the access network device. The system information block message includes the second time information t2 of the access network device.

[0329] 708d: The second terminal device receives the system message block message.

[0330] 708e: The second terminal device performs clock synchronization with the master clock terminal device of the group to which it belongs based on offset2 and t2.

[0331] For example, offset2 and t2 can be added to obtain the corrected time.

[0332] In this implementation, if the second terminal device only supports base station timing or the timing service in the ProSe service and the path preference corresponding to the Uu interface, the second terminal device can obtain the clock deviation (i.e., the second clock deviation) between the master clock terminal device of the group to which it belongs and the access network device from the application layer, and can obtain the time information of the access network device (i.e., the second time information) through the SIB message sent by the access network device, so that it can use the second clock deviation and the second time information to synchronize the clock with the master clock terminal device of the group to which it belongs, thereby ensuring the reliability and continuity of the timing for the second terminal device. Obtaining the clock deviation between the master clock terminal device and the access network device from the application layer is more conducive to saving signaling overhead than transmitting the clock deviation through unicast messages / encrypted broadcasts.

[0333] Please refer to FIG. 9B , which is a flowchart of another timing method provided in an embodiment of the present application. As shown in FIG. 9B , based on the embodiment shown in FIG. 9 , the method may further include steps 709a-709g:

[0334] 709a: The second terminal device sends a first message to the first terminal device.

[0335] The first message includes the timing mode supported by the second terminal device, and the timing mode supported by the second terminal device is used by the first terminal device to provide time to the second terminal device.

[0336] If the second terminal device is within the RAN coverage area and the second terminal device only supports base station timing or the path preference corresponding to the ProSe service information is the Uu interface, the second terminal device can switch to timing by the access network device (for example, if the timing message of the first terminal device is not received):

[0337] 709b: The second terminal device sends a second message to the AF network element.

[0338] The second message is used to request that the access network device be enabled to provide timing to the second terminal device. The second message includes the ID of the second terminal device and the group ID of the group to which the second terminal device belongs. The ID of the second terminal device identifies the terminal device requesting timing from the access network device. The group ID indicates that the second terminal device needs to obtain the clock deviation between the group's master clock time and the access network device's time.

[0339] In this implementation, if the second terminal device only supports base station timing or the timing service in the ProSe service and the path preference corresponding to the timing service is Uu interface, the second terminal device can send a timing request (i.e., a second message) to the core network side, and can add its own ID and group ID in the timing request to request the access network device to send the second clock deviation, thereby facilitating clock synchronization with the master clock terminal device of the group to which it belongs.

[0340] Exemplarily, as shown in FIG10 , the processing of the second message by the core network side may include the following steps:

[0341] (1) The AF network element receives a second message sent by the second terminal device;

[0342] The second message may be unicast via the access network device.

[0343] (2) The AF network element sends a first request to the NEF network element;

[0344] The first request may include the ID of the second terminal device, the ID of the first terminal device, and the group identifier of the group to which the second terminal device belongs. For example, the first request may be “Nnef_ASTI_Create_Req”.

[0345] (3) The NEF network element authenticates the first request and sends a second request to the TSCTSF network element after authentication is successful;

[0346] The second request may include the ID of the second terminal device, the ID of the first terminal device, and the group identifier of the group to which the second terminal device belongs. For example, the second request may be "Ntsctsf_ASTI_Create_Req".

[0347] (4) After receiving the second request, the TSCTSF network element obtains the group member subscription data from the UDM network element and determines whether the timing service requested by the AF network element is valid. For example, the TSCTSF network element can interact with the UDM network element through "Nudm_SDM_Get";

[0348] (5) The TSCTSF network element sends a third request to the PCF network element when determining that the timing service requested by the AF network element is valid;

[0349] The third request may include the ID of the second terminal device, the ID of the first terminal device and the group identifier of the group to which the second terminal device belongs. The third request is used to initiate an AM policy for timing the second terminal device. For example, the third request may be "Npcf_AMPolicyAuthorization_Create_Req".

[0350] (6) PCF network elements and AMF network elements collaborate to provide AM policy;

[0351] (7) The PCF network element responds to the request of the TSCTSF network element, for example, by responding through "Npcf_AMPolicyAuthorization_Create_Resp";

[0352] (8) The TSCTSF network element responds to the request of the NEF network element, for example, it can respond through "Ntsctsf_ASTI_Create_Resp";

[0353] (9) The AMF network element sends an N2 message to the access network device.

[0354] 709c: The access network device receives the third message sent by the AMF network element.

[0355] Among them, the third message includes the ID of the second terminal device and the group ID of the group to which the second terminal device belongs; the ID of the second terminal device is used to identify the terminal device requesting time synchronization from the access network device; the group ID is used to indicate that the second terminal device needs to obtain the clock deviation between the group's master clock time and the time of the access network device; the third message can be an N2 message.

[0356] The third message is sent by the AMF network element when the TSCTSF network element confirms that the second message sent by the second terminal device to the AF network element is valid. In this implementation, when the core network side determines that the timing request sent by the second terminal device is valid, it sends the third message to the access network device to enable the access network device to provide time for the second terminal device, thereby ensuring the reliability of the timing of the second terminal device.

[0357] 709d: The access network device obtains offset2 from the UDM network element based on the group ID.

[0358] 709e: The access network device sends a broadcast message and sends a second unicast message to the second terminal device.

[0359] The second unicast message includes offset2, and the broadcast message includes t2. Exemplarily, the second unicast message also includes a group ID, which is used to indicate that the second clock offset is the clock offset between the group's master clock time and the access network device time.

[0360] In this implementation, the access network device can add the group ID of the group to which the second terminal device belongs in the second unicast message, so that the second terminal device can determine the second clock deviation as the clock deviation between the master clock time of the group to which it belongs and the time of the access network device, thereby enabling the second terminal device to use the second clock deviation to synchronize the clock with the master clock terminal device of the group to which it belongs.

[0361] 709f: The second terminal device receives the second unicast message and broadcast message sent by the access network device.

[0362] 709g: The second terminal device performs clock synchronization with the master clock terminal device of the group to which it belongs based on offset2 and t2.

[0363] In this implementation, if the second terminal device only supports base station timing or the timing service in the ProSe service and the path preference corresponding to the timing service is Uu interface, the second terminal device can send a timing request (i.e., a second message) to the core network side, and can add its own identifier and group identifier in the timing request to request the access network device to send the second clock deviation and second time information, so that the second clock deviation and the second time information can be used to synchronize the clock with the master clock terminal device of the group to which it belongs, thereby ensuring the reliability and continuity of timing for the second terminal device.

[0364] Please refer to FIG11 , which is a flow chart of another timing method provided in an embodiment of the present application. As shown in FIG11 , the method may include steps 1101-1105:

[0365] 1101: The first terminal device sends a direct communication request to the second terminal device.

[0366] In an embodiment of the present application, a direct communication request is used to request the establishment of a direct communication link (i.e., a direct link). When the first terminal device needs to communicate directly with the second terminal device, it can initiate the process of establishing a direct communication link. For example: a scenario where the first terminal device needs to provide time for the second terminal device. For example, in a group timing scenario, a group needs to be created on the core network side, and then the group's leader UE, member UE, group ID and master clock UE (for example: leader UE) are pre-configured at the application layer. It should be noted that the leader UE may be a terminal device within the group or may not be a terminal device within the group.

[0367] Exemplarily, when the path preference of the ProSe service providing the timing service is the PC5 interface, the process of establishing a direct link can be initiated within the group. For example, the path preference corresponding to the ID of the ProSe service (exemplarily, it can be the ID of the ProSe service at the application layer) can be queried. If the path preference is PC5 perferred (can be pre-configured), the terminal devices in the group can determine the layer 2 identifier (Layer-2 ID) of the direct communication request (also known as unicast link establishment signaling) they receive. The ProSe application in the first terminal device can provide application information for the establishment of a direct link. The application information may include information about the ProSe service (for example, it can be the ID of the ProSe service), the ID of the first terminal device (leader UE) (exemplarily, it can be the ID of the first terminal device at the application layer), and the IDs of some or all terminal devices (member UEs) in the group other than the first terminal device (exemplarily, it can be the ID of the member UE at the application layer). Among them, the ID of the ProSe service is used to identify the need to establish a direct link to perform ProSe timing service, the ID of the first terminal device is used to uniquely identify the first terminal device, the ID of the member UE is used to uniquely identify the corresponding terminal device, and the second terminal device can be any member UE in the group.

[0368] Exemplarily, the first terminal device may send a direct communication request to the Layer-2 ID of the second terminal device through its own Layer-2 ID. The direct communication request may include source terminal device information (e.g., the ID of the first terminal device), target terminal device information (e.g., the ID of at least one target terminal device), and the ID of the ProSe service. For example, the ID of the first terminal device may be the ID of the leader UE, and the ID of the at least one target terminal device may be the IDs of some or all terminal devices other than the first terminal device in the application information provided by the ProSe application. The at least one target terminal device may be a terminal device indicating that a direct link needs to be established with the first terminal device.

[0369] Optionally, the direct communication request may also include security information (Security Information), and the terminal device that needs to use the ProSe timing service needs to establish security with the first terminal device.

[0370] 1102: The second terminal device receives a direct communication request from the first terminal device.

[0371] In an embodiment of the present application, the second terminal device can receive a direct communication request through its own Layer-2 ID. Optionally, if the ID of at least one target terminal device of the direct communication request includes the ID of the second terminal device, the second terminal device establishes security with the first terminal device; if the ID of at least one target terminal device of the direct communication request does not include the ID of the second terminal device, but the second terminal device needs to perform ProSe timing service, the second terminal device can also establish security with the first terminal device. When security protection is turned on, if the first terminal device and the second terminal device use IP communication, the first terminal device and the second terminal device negotiate to configure an IP address for the link, and the first terminal device may also send PC5 QoS flow information and PC5 QoS rules (optional) to the second terminal device. Among them, QoS flow information is used to negotiate the application's demand for traffic with the second terminal device; QoS rules are used to negotiate the rules for allocating traffic on the link.

[0372] 1103: The second terminal device sends a first message to the first terminal device.

[0373] In an embodiment of the present application, the first message may be an acceptance message for the direct communication request. When the second terminal device determines that the ID of the at least one target terminal device includes the ID of the second terminal device, the second terminal device sends an acceptance message for the direct communication request to the first terminal device; or when the second terminal device determines that the ID of the at least one target terminal device does not include the ID of the second terminal device and the ProSe timing service is required, the second terminal device sends an acceptance message for the direct communication request to the first terminal device; or when the second terminal device is determined to be included in the ID of the at least one target terminal device and security is successfully established with the first terminal device, the second terminal device sends an acceptance message for the direct communication request to the first terminal device; or when the second terminal device is determined to be not included in the ID of the at least one target terminal device and the ProSe timing service is required and security is successfully established with the first terminal device, the second terminal device sends an acceptance message for the direct communication request to the first terminal device.

[0374] In this implementation, the second terminal device can send an acceptance message for the direct communication request to the first terminal device when it is determined that the ID of at least one target terminal device includes its own ID; or it can send an acceptance message for the direct communication request to the first terminal device when it is determined that the ID of at least one target terminal device does not include its own ID and ProSe timing service is required, thereby establishing a direct link with the first terminal device, and being able to send the timing method supported by itself to the first terminal device to assist the first terminal device in deciding a reasonable timing method for timing the second terminal device based on the timing methods supported by the two.

[0375] 1104: The first terminal device receives a first message from the second terminal device.

[0376] In an embodiment of the present application, the first message includes the timing modes supported by the second terminal device. The timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, PTP timing, and base station timing, and may also include other timing modes. Optionally, the first message may also include the ID of the second terminal device, PC5 QoS flow information, PC5 QoS rules, and IP address negotiation information.

[0377] 1105: The first terminal device provides time to the second terminal device based on the time service mode supported by the second terminal device.

[0378] In the embodiment of the present application, the specific implementation method of step 1105 can refer to the relevant description of step 703 in Figure 7, or refer to the relevant description of steps 703a-703c in Figure 7A, or refer to the relevant description of steps 704a-704c in Figure 7C, and can achieve the same or similar beneficial effects.

[0379] In this implementation, the first terminal device can initiate a process of establishing a direct link with the second terminal device through a direct communication request. The second terminal device can respond to the direct communication request by receiving a message, successfully establish a direct link with the first terminal device, and send the supported timing method to the first terminal device, so that the first terminal device can provide time to the second terminal device through the established direct link based on the timing method supported by the second terminal device. The first terminal device and the second terminal device determine the timing method and perform timing through a negotiation process, so that whether the second terminal device is within the coverage of the wireless access network, the first terminal device can provide time to the second terminal device through ProSe, without having to rely heavily on the access network device for timing, thereby achieving a more reasonable way to provide time to the terminal device, which is conducive to ensuring the reliability and effectiveness of the timing.

[0380] To better understand the direct link establishment process and the timing process based on the direct link, the following is a brief description using a group as an example. The group includes UE1, UE2, UE3, UE4, and UE5. UE1 and UE2 are within the NG-RAN coverage area, while UE3 and UE4 are not. UE2, UE3, and UE5 include a Device Side TSN Translator (DS-TT) module, meaning that the hardware capabilities of UE2, UE3, and UE5 enable them to support PTP timing. As shown in Figure 12, the entire process can include the following steps:

[0381] 0: Pre-configure the group leader UE (UE5), member UEs (UE1, UE2, UE3, UE4), group ID, and master clock UE at the application layer;

[0382] If the path preference corresponding to the ProSe service (specifically, the ProSe timing service) is PC5 perferred, a direct link is established:

[0383] 1: UE(s) determines the destination Layer-2 ID for receiving unicast link establishment signaling;

[0384] 2: The ProSe application in the leader UE provides application information (or application requirements) for establishing a unicast link. This application information may include the ProSe service ID, the leader UE ID, and the IDs of some or all member UEs.

[0385] 3: The leader UE sends a direct communication request (Direct Communication Request) to the member UE's Layer-2 ID through its Layer-2 ID to initiate the unicast link establishment process.

[0386] The Direct Communication Request may include source terminal device information (Source User Info), target terminal device information (Target User Info), ProSe information (ProSe Service Info), and security information. The Source User Info may be the ID of the Leader UE; the Target User Info may be the ID of the member UE provided in step 2; and the ProSe Service Info may be the ID of the ProSe service.

[0387] 4: Each member UE establishes security with the leader UE, including:

[0388] 4a: If the Direct Communication Request includes its own ID, it establishes security with the leader UE;

[0389] 4b: If the Direct Communication Request does not include its own ID but the ProSe timing service is required, security establishment is performed with the leader UE;

[0390] When security protection is enabled, if the leader UE and the member UE use IP communication, the leader UE negotiates with the member UE to configure an IP address for the link. The leader UE can also send PC5 QoS flow information and PC5 QoS rules to the member UE;

[0391] 5: The member UE that has successfully established security sends a direct communication accept message to the leader UE;

[0392] The direct communication accept message includes the timing modes supported by the member UE, which include one or more of broadcast timing, unicast timing, PTP timing, or base station timing. For example, UE1 supports broadcast timing, unicast timing, and UE2 supports broadcast timing, unicast timing, and PTP timing. The direct communication accept message may also include the member UE ID, PC5 QoS flow information, PC5 QoS rules, and IP address negotiation information.

[0393] The leader UE selects the corresponding timing mode for the member UE based on the timing modes supported by itself and the timing modes supported by the member UE:

[0394] If PTP timing is used:

[0395] 6a: The leader UE sends a PTP message to the member UEs (e.g., UE2 and UE3).

[0396] The PTP message includes the time information of the leader UE and the group ID of the group to which the leader UE and member UE belong;

[0397] 6b: Member UEs and leader UEs use a request-response mechanism / end-delay mechanism to compensate for clock synchronization errors.

[0398] If broadcast / unicast timing is used:

[0399] 7a: The leader UE sends a sidelink broadcast message or RRC unicast message to the member UEs (e.g., UE1 and UE4);

[0400] The sidelink broadcast message or RRC unicast message also includes the time information of the leader UE and the group ID of the group to which the leader UE and the member UE belong;

[0401] 7b: Member UEs and leader UEs use an RTT-based time compensation mechanism to compensate for clock synchronization errors.

[0402] Please refer to FIG. 13 , which is a flow chart of another timing method provided in an embodiment of the present application. As shown in FIG. 13 , the method may include steps 1301 to 1308:

[0403] 1301: The first terminal device sends a direct communication request to the second terminal device;

[0404] 1302: The second terminal device receives a direct communication request from the first terminal device;

[0405] 1303: The second terminal device sends a first message to the first terminal device;

[0406] 1304: The first terminal device receives a first message from the second terminal device;

[0407] 1305: The first terminal device provides time to the second terminal device based on the time service mode supported by the second terminal device.

[0408] In the embodiment of the present application, the specific implementation of steps 1301-1305 may correspond to the relevant description of steps 1101-1105 in the embodiment shown in Figure 11, and can achieve the same or similar beneficial effects.

[0409] If the direct link between the second terminal device and the first terminal device is disconnected:

[0410] 1306: The second terminal device determines a relay terminal device from the group and establishes a direct link with the relay terminal device;

[0411] Among them, the direct link between the relay terminal device and the first terminal device is not disconnected.

[0412] 1307: The first terminal device provides time to the relay terminal device.

[0413] In an embodiment of the present application, the first terminal device may receive the timing mode sent by the relay terminal device and provide timing to the relay terminal device based on the timing mode supported by the relay terminal device. The timing modes supported by the relay terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol (PTP) timing, and base station timing, and may also include other timing modes.

[0414] 1308: The relay terminal device provides time synchronization for the second terminal device.

[0415] In an embodiment of the present application, the second terminal device and the relay terminal device can establish a direct link through a negotiation process, and send the timing mode supported by them to the relay terminal device. The relay terminal device can obtain the clock deviation between itself and the second terminal device, and send its own time information, the clock deviation and the group ID to the second terminal device, so that the second terminal device can synchronize its clock with the master clock terminal device of the group to which it belongs to the greatest extent, that is, the relay terminal device acts as the leader UE of the second terminal device.

[0416] For example, the second terminal device may send a fourth message to the first terminal device, such as a keep-alive message. The fourth message is used to determine the status of the direct link between the second terminal device and the first terminal device, where the status of the direct link may include being present or disconnected. If the first terminal device responds with an Ack message to the second terminal device after receiving the fourth message, it indicates that the direct link still exists. If the second terminal device does not receive a response from the first terminal device, it determines that the direct link between the second terminal device and the first terminal device is disconnected.

[0417] In this implementation, when the second terminal device determines that the direct link between it and the first terminal device is disconnected, the second terminal device can find a relay terminal device from the group, so that the relay terminal device can provide time to the second terminal device after being timed by the first terminal device, thereby ensuring the reliability and continuity of time synchronization for the second terminal device to the greatest extent.

[0418] Please refer to FIG. 14 , which is a flowchart of another timing method provided in an embodiment of the present application. As shown in FIG. 14 , the method may include steps 1401-1409:

[0419] 1401: The first terminal device sends a direct communication request to the second terminal device;

[0420] 1402: The second terminal device receives a direct communication request from the first terminal device;

[0421] 1403: The second terminal device sends a first message to the first terminal device;

[0422] 1404: The first terminal device receives a first message from the second terminal device;

[0423] 1405: The first terminal device provides time to the second terminal device based on the time service mode supported by the second terminal device;

[0424] In the embodiment of the present application, the specific implementation of steps 1401-1405 may correspond to the relevant description of steps 1101-1105 in the embodiment shown in Figure 11, and can achieve the same or similar beneficial effects.

[0425] If the second terminal device is within the coverage of the wireless access network, and the direct link between the second terminal device and the first terminal device is disconnected, and a direct link cannot be established with the terminal devices in the group (that is, the relay terminal device cannot be found, and the timing is switched to the access network device):

[0426] 1406: The second terminal device obtains offset2 from the application layer;

[0427] Wherein, offset2 is the clock deviation between the access network device and the master clock terminal device of the group to which the second terminal device belongs, and the access network device and the master clock terminal device obtain offset2 based on the RTT measurement mechanism. Wherein, offset2 is uploaded to the application layer by the first terminal device.

[0428] 1407: The access network device sends a system information block message;

[0429] The system information block message includes the time information t2 of the access network device.

[0430] 1408: The second terminal device receives a system message block message;

[0431] 1409: The second terminal device performs clock synchronization with the master clock terminal device of the group to which it belongs based on offset2 and t2.

[0432] In this implementation, if the direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with the terminal devices in the group, the second terminal device can obtain the clock deviation between the master clock terminal device and the access network device from the application layer, and can obtain the time information of the access network device through the SIB message sent by the access network device. It can then use the second clock deviation and second time information to synchronize the clock with the master clock terminal device of the group to which it belongs, thereby ensuring the reliability and continuity of timing for the second terminal device. Obtaining the clock deviation between the master clock terminal device and the access network device from the application layer helps save signaling overhead compared to transmitting the clock deviation via unicast messages / encrypted broadcasts.

[0433] To better understand the timing process after the direct link is disconnected, a brief description is given below using the group in the embodiment shown in FIG. 12 as an example.

[0434] As shown in FIG15 , based on steps 0-7b, the following steps may also be included:

[0435] 8: Member UEs (UE1, UE2, UE3, UE4) send keep-alive messages to the leader UE;

[0436] 9: The leader UE sends a keep-alive Ack message to UE2 and UE4 to indicate that the direct link between UE2 and UE4 and the leader UE still exists;

[0437] If UE3 is out of NG-RAN coverage and the direct link between UE3 and the leader UE is disconnected, UE3 can switch to timing from the relay UE:

[0438] 10: UE3 discovers the relay UE (UE4) from the group and establishes a direct link with the relay UE;

[0439] 11: UE4 sends a unicast message to UE3;

[0440] The unicast message includes the group ID and the time information of UE4.

[0441] UE1 is within the coverage of NG-RAN, and the direct link between UE1 and the leader UE is disconnected. If UE1 cannot establish a direct link with any UE in the group, UE1 can switch to timing by the base station:

[0442] 12a: The access network device and the leader UE obtain the clock offset between them based on the RTT measurement mechanism;

[0443] 12b: The access network device sends the clock offset to the leader UE;

[0444] 12c: The leader UE uploads the clock deviation to the application layer;

[0445] 13: UE1 obtains the clock deviation from the application layer;

[0446] 14: The access network device broadcasts its time information to UE1 via SIB9;

[0447] 15: UE1 obtains the time of the leader UE based on the acquired clock deviation and time information.

[0448] It should be noted that steps 12a-12c can be decoupled from the steps before step 13 in implementation. For example, steps 12a-12c can be implemented before these steps (one or more steps before step 13), or after these steps, or in parallel with these steps, etc.

[0449] Please refer to FIG. 16 , which is a flowchart of another timing method provided in an embodiment of the present application. As shown in FIG. 16 , the method may include steps 1601-1611:

[0450] 1601: The first terminal device sends a direct communication request to the second terminal device;

[0451] 1602: The second terminal device receives a direct communication request from the first terminal device;

[0452] 1603: The second terminal device sends a first message to the first terminal device;

[0453] 1604: The first terminal device receives a first message from the second terminal device;

[0454] 1605: The first terminal device provides time to the second terminal device based on the time service mode supported by the second terminal device.

[0455] In the embodiment of the present application, the specific implementation of steps 1601-1605 may correspond to the relevant description of steps 1101-1105 in the embodiment shown in Figure 11, and can achieve the same or similar beneficial effects.

[0456] If the second terminal device is within the coverage of the wireless access network, and the direct link between the second terminal device and the first terminal device is disconnected, and a direct link cannot be established with the terminal devices in the group (that is, the relay terminal device cannot be found, and the timing is switched to the access network device):

[0457] 1606: The second terminal device sends a second message to the AF network element;

[0458] The second message is used to request that the access network device be enabled to provide timing to the second terminal device. The second message includes the ID of the second terminal device and the group ID of the group to which the second terminal device belongs. The ID of the second terminal device identifies the terminal device requesting timing from the access network device. The group ID indicates that the second terminal device needs to obtain the clock deviation between the group's master clock and the access network device's time. The core network's processing of the second message can be referred to the description of the embodiment shown in Figure 10.

[0459] 1607: The access network device receives the third message sent by the AMF network element;

[0460] Among them, the third message includes the ID of the second terminal device and the group ID of the group to which the second terminal device belongs; the ID of the second terminal device is used to identify the terminal device requesting time synchronization from the access network device; the group ID is used to indicate that the second terminal device needs to obtain the clock deviation between the group's master clock time and the time of the access network device; the third message can be an N2 message.

[0461] Among them, the third message is sent by the AMF network element when the TSCTSF network element confirms that the second message sent by the second terminal device to the AF network element is valid.

[0462] 1608: The access network device obtains offset2 from the UDM network element based on the group ID.

[0463] 1609: The access network device sends a broadcast message and a second unicast message to the second terminal device.

[0464] 1610: The second terminal device receives the second unicast message and the broadcast message sent by the access network device;

[0465] 1611: The second terminal device performs clock synchronization with the master clock terminal device of the group to which it belongs based on offset2 and t2.

[0466] In this implementation, if the direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with the terminal devices in the group, the second terminal device can send a timing request (i.e., a second message) to the core network side, and can add its own identifier and group identifier in the timing request to request the access network device to send a second clock deviation and second time information, so that the second clock deviation and second time information can be used to synchronize the clock with the master clock terminal device of the group to which it belongs, thereby ensuring the reliability and continuity of timing for the second terminal device.

[0467] To better understand the timing process after the direct link is disconnected, a brief description is given below using the group in the embodiment shown in FIG. 12 as an example.

[0468] As shown in FIG17 , based on steps 0-7b, the following steps may also be included:

[0469] 8: Member UEs (UE1, UE2, UE3, UE4) send keep-alive messages to the leader UE;

[0470] 9: The leader UE sends a keep-alive Ack message to UE2 (and UE4) to indicate that the direct link between UE2 (and UE4) and the leader UE still exists;

[0471] 16a: The access network device and the leader UE obtain the clock offset between them through the RTT measurement mechanism;

[0472] 16b: The access network device sends the clock deviation to the UDM network element for storage;

[0473] UE1 is within the coverage of NG-RAN, and the direct link between UE1 and the leader UE is disconnected. If UE1 cannot establish a direct link with any UE in the group, UE1 can switch to timing by the base station:

[0474] 17: UE1 sends a timing request to the AF network element;

[0475] The timing request is used to request that the access network device provide timing for UE1. It includes UE1's ID and the group ID of the group to which UE1 belongs. UE1's ID identifies the terminal device requesting timing from the access network device. The group ID indicates that UE1 needs to obtain the clock deviation between the group's master clock and the access network device's time.

[0476] 18: The access network device receives the N2 message sent by the AMF network element;

[0477] The N2 message includes the ID of UE1 and the group ID of the group to which UE1 belongs. The ID of UE1 is used to identify the terminal device requesting timing from the access network device. The group ID is used to indicate that UE1 needs to obtain the clock deviation between the group's master clock time and the access network device time. The N2 message is sent by the AMF network element when the TSCTSF network element confirms that the timing request sent by UE1 to the AF network element is valid.

[0478] 19: The access network device obtains the clock deviation from the UDM network element based on the group ID;

[0479] 20: The access network device sends a broadcast message and an RRC unicast message to UE1;

[0480] The RRC unicast message includes the clock offset between the access network device and the leader UE, while the broadcast message includes the time information of the access network device. Exemplarily, the RRC unicast message also includes a group ID; the group ID is used to indicate that the clock offset is the clock offset between the group's master clock time and the access network device time.

[0481] 21: UE1 receives RRC unicast messages and broadcast messages sent by the access network device;

[0482] 22: UE1 obtains the time of the leader UE based on the acquired clock deviation and time information.

[0483] It should be noted that steps 16a and 16b can be decoupled from the steps before step 17 in implementation. For example, steps 16a and 16b can be implemented before these steps (one or more steps before step 17), or after these steps, or in parallel with these steps, etc.

[0484] It should be noted that since UE3 is not within the coverage of NG-RAN, if UE3 does not receive the keep-alive Ack message from the leader UE, UE3 can obtain timing by looking for a relay UE.

[0485] The method of the embodiment of the present application is described above, and the device of the embodiment of the present application is provided below.

[0486] Please refer to Figure 18, which is a schematic diagram of the structure of a timing device provided in an embodiment of the present application. The device can be applied to a first terminal device. As shown in Figure 18, the device may include a first transceiver unit 1801 and a first processing unit 1802; wherein:

[0487] The first transceiver unit 1801 is configured to receive a first message from a second terminal device; the first message includes a timing mode supported by the second terminal device;

[0488] The first processing unit 1802 is configured to provide time service for the second terminal device based on a time service mode supported by the second terminal device.

[0489] It can be seen that in the apparatus shown in FIG18 , the first terminal device can receive the timing mode sent by the second terminal device, and thus can provide timing to the second terminal device based on the timing mode supported by the second terminal device. The first terminal device and the second terminal device determine the timing mode through a negotiation process and perform timing. This allows the first terminal device to provide timing to the second terminal device through ProSe, regardless of whether the second terminal device is within the coverage of the wireless access network, without having to rely heavily on the access network device for timing. This allows the terminal device to be timed in a more reasonable manner, which in turn helps ensure the reliability and effectiveness of timing.

[0490] In one possible implementation, the timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing, and base station timing;

[0491] The timing modes supported by the first terminal device include one or more of broadcast timing, unicast timing, PTP timing and base station timing.

[0492] In one possible implementation, in providing time to the second terminal device based on the time service mode supported by the second terminal device, the first processing unit 1802 is specifically configured to:

[0493] Determine the timing mode for the second terminal device to perform timing based on the timing mode supported by the terminal device and the timing mode supported by the second terminal device;

[0494] The second terminal device is provided with time service based on the determined time service method.

[0495] In one possible implementation, in providing time to the second terminal device based on the time service mode supported by the second terminal device, the first processing unit 1802 is specifically configured to:

[0496] If the determined timing mode is PTP timing, instruct the first transceiver unit to send a PTP message to the second terminal device through the direct link between the first transceiver unit and the second terminal device;

[0497] Among them, the PTP message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the first clock deviation after obtaining the first clock deviation from the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0498] In one possible implementation, in providing time to the second terminal device based on the time service mode supported by the second terminal device, the first processing unit 1802 is specifically configured to:

[0499] If the determined timing mode is broadcast timing, the first transceiver unit 1801 is instructed to send a sidelink broadcast message;

[0500] If the determined timing mode is unicast timing, instruct the first transceiver unit 1801 to send a first unicast message to the second terminal device through the direct link between the first transceiver unit 1801 and the second terminal device;

[0501] Among them, the sidelink broadcast message or the first unicast message includes the first time information and the group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0502] In a possible implementation, the propagation delay is obtained by the first terminal device and the second terminal device based on an RTT measurement mechanism.

[0503] In a possible implementation, the first transceiver unit 1801 is further configured to:

[0504] Sending a direct communication request to the second terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that ProSe timing service needs to be performed by establishing a direct link;

[0505] The first message is sent when the second terminal device determines that the identifier of at least one target terminal device includes the identifier of the second terminal device.

[0506] In a possible implementation, the first transceiver unit 1801 is further configured to:

[0507] Sending a direct communication request to the second terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that ProSe timing service needs to be performed by establishing a direct link;

[0508] The first message is sent when the second terminal device determines that the identifier of at least one target terminal device does not include the identifier of the second terminal device and ProSe timing service is required.

[0509] In a possible implementation, the direct communication request is sent when the path preference corresponding to the ProSe service information is a PC5 interface.

[0510] In a possible implementation, the first transceiver unit 1801 is further configured to:

[0511] Receive a second clock deviation sent by the access network device; the second clock deviation is the clock deviation between the master clock terminal device and the access network device;

[0512] Upload the second clock offset to the application layer; or,

[0513] The second clock deviation is sent to the unified data management network element for storage.

[0514] It should be noted that the implementation of each unit described in Figure 18 can also correspond to the corresponding description of the embodiments shown in Figures 7 to 17. In addition, the beneficial effects brought about by the timing device described in Figure 18 can be referred to the corresponding description of the embodiments shown in Figures 7 to 17, and will not be repeated here.

[0515] Please refer to Figure 19, which is a schematic diagram of the structure of another timing device provided in an embodiment of the present application. The device can be applied to a second terminal device. As shown in Figure 19, the device can include a second transceiver unit 1901 and a second processing unit 1902; wherein:

[0516] The second transceiver unit 1901 is used to send a first message to the first terminal device; the first message includes the timing mode supported by the second terminal device; the timing mode supported by the second terminal device is used by the first terminal device to provide time to the second terminal device.

[0517] It can be seen that in the apparatus shown in FIG19 , the second terminal device can send the timing mode it supports to the first terminal device, so that the first terminal device can provide time to the second terminal device based on the timing mode supported by the second terminal device. The first terminal device and the second terminal device determine the timing mode and perform timing through a negotiation process, so that whether the second terminal device is within the coverage of the wireless access network, the first terminal device can provide time to the second terminal device through ProSe, without having to rely heavily on the access network device for timing, thereby achieving a more reasonable way to provide time to the terminal device, which is conducive to ensuring the reliability and effectiveness of the timing.

[0518] In one possible implementation, the timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing, and base station timing;

[0519] The timing modes supported by the first terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing and base station timing.

[0520] In a possible implementation, the second transceiver unit 1901 is further configured to:

[0521] Receiving a PTP message sent by the first terminal device through a direct link between the first terminal device and the second terminal device;

[0522] Among them, the PTP message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the first clock deviation after obtaining the first clock deviation from the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0523] In a possible implementation, the second transceiver unit 1901 is further configured to:

[0524] receiving at least one sidelink broadcast message; wherein the at least one sidelink broadcast message includes a sidelink broadcast message sent by a first terminal device; the sidelink broadcast message sent by the first terminal device includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of a group to which the second terminal device belongs; the first time information is used by the second terminal device to perform clock synchronization based on the first time information and the propagation delay after obtaining a propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is a master clock time of the group; or,

[0525] Receive a first unicast message sent by a first terminal device through a direct link between the first terminal device and the second terminal device; wherein the first unicast message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of the group to which the second terminal device belongs; the first time information is used by the second terminal device to synchronize its clock based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0526] In a possible implementation, the propagation delay is obtained by the first terminal device and the second terminal device based on an RTT measurement mechanism.

[0527] In a possible implementation, the second transceiver unit 1901 is further configured to:

[0528] receiving a direct communication request from a first terminal device; the direct communication request including an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service is required by establishing a direct link;

[0529] In terms of sending an acceptance message of the direct communication request to the first terminal device, the second transceiver unit 1901 is specifically configured to:

[0530] When it is determined that the identifier of the at least one target terminal device includes the identifier of the second terminal device, an acceptance message for the direct communication request is sent to the first terminal device.

[0531] In a possible implementation, the second transceiver unit 1901 is further configured to:

[0532] receiving a direct communication request from a first terminal device; the direct communication request including an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service is required by establishing a direct link;

[0533] In terms of sending an acceptance message of the direct communication request to the first terminal device, the second transceiver unit 1901 is specifically configured to:

[0534] When it is determined that the identifier of the at least one target terminal device does not include the identifier of the second terminal device and the ProSe timing service is required, an acceptance message for the direct communication request is sent to the first terminal device.

[0535] In a possible implementation, the direct communication request is sent when the path preference corresponding to the ProSe service information is a PC5 interface.

[0536] In one possible implementation, the second processing unit 1902 is used to determine a relay terminal device from the group and establish a direct link with the relay terminal device when it is determined that the direct link between the second terminal device is disconnected, so that the relay terminal device can provide time to the second terminal device after being provided time by the first terminal device.

[0537] In one possible implementation, the second terminal device is within the coverage of the wireless access network; the direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with the terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the ProSe service information is a Uu interface:

[0538] The second processing unit 1902 is configured to obtain a second clock deviation from the application layer; the second clock deviation is a clock deviation between the master clock terminal device and the access network device;

[0539] The second transceiver unit 1901 is further configured to receive a system information block message sent by an access network device; the system information block message includes second time information of the access network device;

[0540] The second processing unit 1902 is further configured to perform clock synchronization with the master clock terminal device of the group based on the second clock deviation and the second time information;

[0541] or,

[0542] The second transceiver unit 1901 is further configured to send a second message to the application function network element; the second message is used to request that the access network device be enabled to provide time synchronization for the second terminal device; receive a second unicast message and a broadcast message sent by the access network device; the second unicast message includes a second clock deviation; the second clock deviation is the clock deviation between the master clock terminal device and the access network device; the broadcast message includes second time information of the access network device; the second clock deviation is obtained by the access network device from the unified data management network element;

[0543] The second processing unit 1902 is configured to perform clock synchronization with the master clock terminal device of the group to which it belongs based on the second clock deviation and the second time information.

[0544] In one possible implementation, the second message includes an identifier of the second terminal device and a group identifier; the identifier of the second terminal device is used to identify the terminal device requesting time synchronization from the access network device; the group identifier is used to indicate that the second terminal device needs to obtain the clock deviation between the group's master clock time and the time of the access network device.

[0545] In a possible implementation, the second unicast message further includes a group identifier; the group identifier is used to indicate that the second clock deviation is a clock deviation between a master clock time of the group and a time of the access network device.

[0546] It should be noted that the implementation of each unit described in Figure 19 can also correspond to the corresponding description of the embodiments shown in Figures 7 to 17. In addition, the beneficial effects brought about by the timing device described in Figure 19 can be referred to the corresponding description of the embodiments shown in Figures 7 to 17, and will not be repeated here.

[0547] Please refer to Figure 20, which is a schematic diagram of the structure of another timing device provided in an embodiment of the present application. The device can be applied to access network equipment. As shown in Figure 20, the device can include a third transceiver unit 2001 and a third processing unit 2002; wherein:

[0548] The third processing unit 2002 is configured to obtain a second clock deviation from a master clock terminal device of a group to which the second terminal device belongs;

[0549] The third transceiver unit 2001 is used to send the second clock deviation to the first terminal device so that the first terminal device uploads the second clock deviation to the application layer; or send the second clock deviation to the unified data management network element for storage.

[0550] It can be seen that in the device shown in Figure 20, the access network device can send the second clock deviation of the master clock terminal device of the group to which the second terminal device belongs to the first terminal device, so that the first terminal device can send it to the application layer, and can also store it in the unified data management network element, so that when the direct link between the second terminal device and the first terminal device is disconnected or the second terminal device only supports base station timing or the path preference corresponding to the ProSe service information is the Uu interface, the second terminal device can obtain the second clock deviation from the application layer or send the second clock deviation through the access network device, thereby ensuring that the second terminal device can synchronize the clock with the master clock terminal device of the group to which it belongs through the access network device, thereby ensuring the reliability and continuity of timing for the second terminal device.

[0551] In a possible implementation, in terms of sending the second clock deviation to the unified data management network element for storage, the third transceiver unit 2001 is specifically configured to:

[0552] sending the second clock deviation to the access and mobility management function network element, so that the access and mobility management function network element sends the second clock deviation to the unified data management network element for storage; or,

[0553] The second clock deviation is sent to the time-sensitive communication and time synchronization function network element, so that the time-sensitive communication and time synchronization function network element sends the second clock deviation to the unified data management network element for storage.

[0554] In a possible implementation, the third transceiver unit 2001 is further configured to:

[0555] Receive a third message sent by the access and mobility management function network element; the third message includes an identifier of the second terminal device and a group identifier of the group to which the second terminal device belongs; the identifier of the second terminal device is used to identify the terminal device requesting time synchronization from the access network device; the group identifier is used to indicate that the second terminal device needs to obtain the clock deviation between the master clock time of the group and the time of the access network device; the second terminal device is within the coverage of the wireless access network; the direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with the terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the ProSe service information is the Uu interface;

[0556] Obtaining a second clock offset from a unified data management network element based on the group identifier;

[0557] Sending a second unicast message to the second terminal device; the second unicast message includes a second clock deviation and a group identifier; the group identifier is used to indicate that the second clock deviation is a clock deviation between the master clock time of the group and the time of the access network device;

[0558] Send a broadcast message; the broadcast message includes the second time information of the access network device.

[0559] In one possible implementation, the third message is sent by the access and mobility management function network element when the time-sensitive communication and time synchronization function network element confirms that the second message sent by the second terminal device to the application function network element is valid; the second message is used to request that the access network device be enabled to provide time synchronization for the second terminal device.

[0560] In a possible implementation, the second clock deviation is obtained by the access network device and the master clock terminal device based on an RTT measurement mechanism.

[0561] It should be noted that the implementation of each unit described in Figure 20 can also correspond to the corresponding description of the embodiments shown in Figures 7 to 17. In addition, the beneficial effects brought about by the timing device described in Figure 20 can be referred to the corresponding description of the embodiments shown in Figures 7 to 17, and will not be repeated here.

[0562] Based on the description of the above method embodiment and device embodiment, the embodiment of the present application also provides an electronic device. Please refer to Figure 21, which is a structural diagram of an electronic device provided in an embodiment of the present application, and the electronic device at least includes a processor 2101, a memory 2102 and a communication interface 2103, and the processor 2101, the memory 2102 and the communication interface 2103 are interconnected via a bus 2104. The electronic device can be used to execute the relevant steps of the timing method. The electronic device can be a terminal device (such as UE) or a chip in a terminal device, or it can be an access network device, or it can also be a robot device with communication capabilities, etc. The processor 2101 in the electronic device is used to read the computer program code stored in the above-mentioned memory 2102 and execute the method of any one of the embodiments shown in Figures 7 to 17.

[0563] The memory 2102 includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM), and is used to store relevant computer programs and data.

[0564] The processor 2101 may be one or more central processing units (CPUs). When the processor 2101 is a CPU, the CPU may be a single-core CPU or a multi-core CPU.

[0565] In one example, the processor 2101 in the electronic device may be configured to read one or more programs stored in the memory 2102 and cooperate with the communication interface 2103 to perform the following operations:

[0566] A first message is received from a second terminal device through the communication interface 2103; the first message includes a timing mode supported by the second terminal device; and timing is provided to the second terminal device based on the timing mode supported by the second terminal device.

[0567] In one possible implementation, the timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing, and base station timing;

[0568] The timing modes supported by the electronic device include one or more of broadcast timing, unicast timing, PTP timing and base station timing.

[0569] In one possible implementation, the processor 2101 performs timing service for the second terminal device based on the timing service mode supported by the second terminal device, including:

[0570] Determining a timing mode for the second terminal device to perform timing based on the timing mode supported by the electronic device and the timing mode supported by the second terminal device; wherein the timing mode for performing timing for the second terminal device is one of the intersections of the timing mode supported by the electronic device and the timing mode supported by the second terminal device;

[0571] The second terminal device is provided with time service based on the determined time service method.

[0572] In one possible implementation, the processor 2101 performs timing service for the second terminal device based on the timing service mode supported by the second terminal device, including:

[0573] If the determined timing mode is PTP timing, the communication interface 2103 is instructed to send a PTP message to the second terminal device through the direct link between the second terminal device and the second terminal device;

[0574] Among them, the PTP message includes first time information and a group identifier; the first time information is added by the electronic device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the first clock deviation after obtaining the first clock deviation from the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0575] In one possible implementation, the processor 2101 performs timing service for the second terminal device based on the timing service mode supported by the second terminal device, including:

[0576] If the timing mode determined is broadcast timing, the communication interface 2103 is instructed to send a sidelink broadcast message;

[0577] If the determined timing mode is unicast timing, instruct the communication interface 2103 to send a first unicast message to the second terminal device through the direct link between the second terminal device and the second terminal device;

[0578] Among them, the sidelink broadcast message or the first unicast message includes the first time information and the group identifier; the first time information is added by the electronic device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to synchronize the clock based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

[0579] In a possible implementation, the propagation delay is obtained by the first terminal device and the second terminal device based on a round-trip time (RTT) measurement mechanism.

[0580] In a possible implementation, before receiving the first message from the second terminal device, the processor 2101 is further configured to:

[0581] Sending a direct communication request to the second terminal device through the communication interface 2103; the direct communication request includes an identifier of the electronic device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the electronic device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service is required by establishing a direct link;

[0582] The first message is sent when the second terminal device determines that the identifier of at least one target terminal device includes the identifier of the second terminal device.

[0583] In a possible implementation, before receiving the first message from the second terminal device, the processor 2101 is further configured to:

[0584] Sending a direct communication request to the second terminal device through the communication interface 2103; the direct communication request includes an identifier of the electronic device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the electronic device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service is required by establishing a direct link;

[0585] The first message is sent when the second terminal device determines that the identifier of at least one target terminal device does not include the identifier of the second terminal device and ProSe timing service is required.

[0586] In a possible implementation, the direct communication request is sent when the path preference corresponding to the ProSe service information is a PC5 interface.

[0587] In a possible implementation, the processor 2101 is further configured to:

[0588] Receive a second clock deviation sent by the access network device through the communication interface 2103; the second clock deviation is the clock deviation between the master clock terminal device and the access network device;

[0589] Upload the second clock offset to the application layer; or,

[0590] The second clock deviation is sent to the unified data management network element through the communication interface 2103 for storage.

[0591] In another example, the processor 2101 in the electronic device may also be configured to read one or more programs stored in the memory 2102 and cooperate with the communication interface 2103 to perform the following operations:

[0592] A first message is sent to the first terminal device through the communication interface 2103; the first message includes the timing mode supported by the electronic device; the timing mode supported by the electronic device is used by the first terminal device to provide time for the electronic device.

[0593] In one possible implementation, the timing modes supported by the first terminal device include one or more of broadcast timing, unicast timing, Precision Time Protocol PTP timing, and base station timing;

[0594] The timing modes supported by the electronic device include one or more of broadcast timing, unicast timing, Precision Time Protocol (PTP) timing, and base station timing.

[0595] In a possible implementation, the processor 2101 is further configured to:

[0596] Receiving, through the communication interface 2103, a PTP message sent by the first terminal device through the direct link between the first terminal device and the electronic device;

[0597] Among them, the PTP message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the electronic device belongs; the first time information is used by the electronic device to synchronize the clock based on the first time information and the first clock deviation after obtaining the first clock deviation from the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group to which the electronic device belongs.

[0598] In a possible implementation, the processor 2101 is further configured to:

[0599] At least one sidelink broadcast message is received through the communication interface 2103; wherein the at least one sidelink broadcast message includes a sidelink broadcast message sent by the first terminal device; the sidelink broadcast message sent by the first terminal device includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of the group to which the electronic device belongs; the first time information is used by the electronic device to perform clock synchronization based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group; or,

[0600] A first unicast message sent by a first terminal device through a direct link between the first terminal device and the electronic device is received through the communication interface 2103; wherein the first unicast message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of the group to which the electronic device belongs; the first time information is used by the electronic device to perform clock synchronization based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group to which the electronic device belongs.

[0601] In a possible implementation, the propagation delay is obtained between the first terminal device and the electronic device based on an RTT measurement mechanism.

[0602] In a possible implementation, before sending the first message to the first terminal device, the processor 2101 is further configured to:

[0603] receiving, via the communication interface 2103, a direct communication request from a first terminal device; the direct communication request including an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device being used to identify the terminal device initiating the direct link establishment process; and the ProSe service information being used to identify a need for ProSe timing service by establishing a direct link;

[0604] The processor 2101 executes sending a first message to the first terminal device, including:

[0605] When it is determined that the identifier of the at least one target terminal device includes the identifier of the electronic device, a first message is sent to the first terminal device through the communication interface 2103 .

[0606] In a possible implementation, the processor 2101 is further configured to:

[0607] receiving, via the communication interface 2103, a direct communication request from a first terminal device; the direct communication request including an identifier of the first terminal device, an identifier of at least one target terminal device, and ProSe service information; the identifier of the first terminal device being used to identify the terminal device initiating the direct link establishment process; and the ProSe service information being used to identify a need for ProSe timing service by establishing a direct link;

[0608] The processor 2101 executes sending an acceptance message of the direct communication request to the first terminal device, including:

[0609] When it is determined that the identifier of the electronic device is not included in the identifier of the at least one target terminal device and the ProSe timing service is required, an acceptance message for the direct communication request is sent to the first terminal device.

[0610] In a possible implementation, the direct communication request is sent when the path preference corresponding to the ProSe service information is a PC5 interface.

[0611] In a possible implementation, the processor 2101 is further configured to:

[0612] When it is determined that the direct link with the first terminal device is disconnected, a relay terminal device is determined from the group and a direct link is established with the relay terminal device so that the relay terminal device provides time to the electronic device after being provided time by the first terminal device.

[0613] In one possible implementation, the electronic device is within coverage of a wireless access network; when a direct link between the electronic device and the first terminal device is disconnected and a direct link cannot be established with terminal devices in the group, or the electronic device only supports base station timing, or the path preference corresponding to the ProSe service information is a Uu interface, the processor 2101 is further configured to:

[0614] Obtaining a second clock deviation from the application layer; the second clock deviation is the clock deviation between the master clock terminal device and the access network device;

[0615] receiving a system information block message sent by the access network device through the communication interface 2103; the system information block message includes the second time information of the access network device;

[0616] Performing clock synchronization with a master clock terminal device of the group based on the second clock deviation and the second time information;

[0617] or,

[0618] Sending a second message to the application function network element via communication interface 2103; the second message is used to request that the access network device be enabled to provide time synchronization for the electronic device; receiving a second unicast message and a broadcast message sent by the access network device; the second unicast message includes a second clock deviation; the second clock deviation is the clock deviation between the master clock terminal device and the access network device; the broadcast message includes second time information of the access network device; the second clock deviation is obtained by the access network device from the unified data management network element;

[0619] Based on the second clock deviation and the second time information, clock synchronization is performed with the master clock terminal device of the group to which it belongs.

[0620] In one possible implementation, the second message includes an identifier of the electronic device and a group identifier; the identifier of the electronic device is used to identify the terminal device requesting time synchronization from the access network device; the group identifier is used to indicate that the electronic device needs to obtain the clock deviation between the group's master clock time and the time of the access network device.

[0621] In a possible implementation, the second unicast message further includes a group identifier; the group identifier is used to indicate that the second clock deviation is a clock deviation between a master clock time of the group and a time of the access network device.

[0622] In another example, the processor 2101 in the electronic device may also be configured to read one or more programs stored in the memory 2102 and cooperate with the communication interface 2103 to perform the following operations:

[0623] Obtaining a second clock deviation from a master clock terminal device of a group to which the second terminal device belongs;

[0624] Sending the second clock deviation to the first terminal device through the communication interface 2103, so that the first terminal device uploads the second clock deviation to the application layer; or,

[0625] The second clock deviation is sent to the unified data management network element through the communication interface 2103 for storage.

[0626] In a possible implementation, the processor 2101 executes sending the second clock deviation to the unified data management network element for storage, including:

[0627] Sending the second clock deviation to the access and mobility management function network element through the communication interface 2103, so that the access and mobility management function network element sends the second clock deviation to the unified data management network element for storage; or,

[0628] The second clock deviation is sent to the time-sensitive communication and time synchronization function network element through the communication interface 2103, so that the time-sensitive communication and time synchronization function network element sends the second clock deviation to the unified data management network element for storage.

[0629] In a possible implementation, the processor 2101 is further configured to:

[0630] A third message sent by the access and mobility management function network element is received through the communication interface 2103; the third message includes an identifier of the second terminal device and a group identifier of the group to which the second terminal device belongs; the identifier of the second terminal device is used to identify the terminal device requesting timing of the electronic device; the group identifier is used to indicate that the second terminal device needs to obtain a clock deviation between the master clock time of the group and the time of the electronic device; the second terminal device is within the coverage of the wireless access network; the direct link between the second terminal device and the first terminal device is disconnected, and a direct link cannot be established with the terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the ProSe service information is the Uu interface;

[0631] Obtaining a second clock offset from a unified data management network element based on the group identifier;

[0632] Sending a second unicast message to the second terminal device via the communication interface 2103; the second unicast message includes a second clock deviation and a group identifier; the group identifier is used to indicate that the second clock deviation is the clock deviation between the master clock time of the group and the time of the electronic device;

[0633] A broadcast message is sent through the communication interface 2103; the broadcast message includes the second time information of the electronic device.

[0634] In one possible implementation, the third message is sent by the access and mobility management function network element when the time-sensitive communication and time synchronization function network element confirms that the second message sent by the second terminal device to the application function network element is valid; the second message is used to request that the electronic device be enabled to provide time synchronization for the second terminal device.

[0635] In a possible implementation, the second clock deviation is obtained between the electronic device and the master clock terminal device based on an RTT measurement mechanism.

[0636] It should be noted that the implementation of each operation may also correspond to the corresponding description of the method of any embodiment shown in Figures 7 to 17.

[0637] It should be noted that although the electronic device shown in Figure 21 only shows the processor 2101, memory 2102, communication interface 2103, and bus 2104, during the specific implementation process, those skilled in the art will understand that the electronic device also includes other components necessary for normal operation. At the same time, according to specific needs, those skilled in the art will understand that the electronic device may also include hardware components that implement other additional functions. In addition, those skilled in the art will understand that the electronic device may also include only the components necessary to implement the embodiments of the present application, and does not necessarily include all the components shown in Figure 21.

[0638] The present application also provides a chip, including a processor configured to call and execute a computer program from a memory, so that a device equipped with the chip executes the method described in any one of the embodiments shown in Figures 7 to 17. The chip may be a chip in an electronic device.

[0639] The embodiment of the present application also provides a computer-readable storage medium (Memory), which stores a computer program. When the computer program is run, the method described in any one of the embodiments in Figures 7 to 17 above is implemented. It can be understood that the computer-readable storage medium here can include both built-in storage media in the device and, of course, extended storage media supported by the device. The computer-readable storage medium provides a storage space that stores the operating system of the device. In addition, one or more computer programs suitable for being loaded and executed by the processor of the device are also stored in the storage space. It should be noted that the computer-readable storage medium here can be a high-speed RAM or a non-volatile memory, such as at least one disk storage; optionally, it can also be at least one computer-readable storage medium located away from the aforementioned processor.

[0640] An embodiment of the present application further provides a computer program product, which includes: computer program code. When the computer program code is executed by an electronic device, the method flow described in any one of the embodiments in Figures 3 to 7 is implemented.

[0641] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0642] It should be understood that the processor mentioned in the embodiments of the present application may be a CPU, or may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0643] It should also be understood that the memory mentioned in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a ROM, a programmable read-only memory (Programmable ROM, PROM), an EPROM, an electrically erasable programmable read-only memory (Electrically EPROM, EEPROM) or a flash memory. The volatile memory can be a RAM, which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM) and direct RAM bus random access memory (DR RAM).

[0644] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) is integrated into the processor.

[0645] It should be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0646] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0647] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely exemplary. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0648] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0649] In addition, the functional units in the various embodiments of the present application may be integrated into a first processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. If the aforementioned integrated units are implemented as software functional units and sold or used as independent products, they may be stored in a computer-readable storage medium.

[0650] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the associated objects are in an "or" relationship.

[0651] The steps in the method of the embodiment of the present application can be adjusted in order, combined and deleted according to actual needs.

[0652] The modules in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs.

[0653] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A timing method, characterized in that: Applied to a first terminal device; the method comprises: Receiving a first message from a second terminal device; the first message includes a timing mode supported by the second terminal device; Based on the timing mode supported by the second terminal device, provide time for the second terminal device.

2. The method according to claim 1, characterized in that The timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, precision time protocol PTP timing and base station timing; The timing modes supported by the first terminal device include one or more of broadcast timing, unicast timing, PTP timing and base station timing.

3. The method according to claim 1 or 2, characterized in that: The providing time for the second terminal device based on the time service mode supported by the second terminal device includes: Determine a timing mode for timing the second terminal device based on the timing mode supported by itself and the timing mode supported by the second terminal device; Provide time to the second terminal device based on the determined time synchronization method.

4. The method according to claim 1, characterized in that The providing time for the second terminal device based on the time service mode supported by the second terminal device includes: If the determined timing mode is PTP timing, sending a PTP message to the second terminal device through the direct link between the second terminal device and the second terminal device; Among them, the PTP message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to perform clock synchronization based on the first time information and the first clock deviation after obtaining the first clock deviation with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

5. The method according to claim 1, characterized in that The providing time for the second terminal device based on the time service mode supported by the second terminal device includes: If the determined timing mode is broadcast timing, a sidelink broadcast message is sent; If the determined timing mode is unicast timing, sending a first unicast message to the second terminal device through the direct link between the second terminal device and the second terminal device; Among them, the sidelink broadcast message or the first unicast message includes the first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to perform clock synchronization based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

6. The method according to claim 5, characterized in that The propagation delay is obtained by the first terminal device and the second terminal device based on a round-trip time RTT measurement mechanism.

7. The method according to any one of claims 1 to 6, characterized in that Before receiving the first message from the second terminal device, the method further includes: Sending a direct communication request to a second terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and information of a proximity service ProSe service; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service needs to be performed by establishing a direct link; The first message is sent when the second terminal device determines that the identifier of the at least one target terminal device includes the identifier of the second terminal device.

8. The method according to any one of claims 1 to 6, characterized in that Before receiving the first message from the second terminal device, the method further includes: Sending a direct communication request to a second terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and information about the ProSe service; the identifier of the first terminal device is used to identify the terminal device that initiates the direct link establishment process; the ProSe service information is used to identify that a ProSe timing service needs to be performed by establishing a direct link; The first message is sent when the second terminal device determines that the identifier of the at least one target terminal device does not include the identifier of the second terminal device and ProSe timing service is required.

9. The method according to claim 7 or 8, characterized in that: The direct communication request is sent when the path preference corresponding to the information of the ProSe service is the PC5 interface.

10. The method according to any one of claims 1 to 9, characterized in that The method further comprises: Receive a second clock deviation sent by the access network device; the second clock deviation is a clock deviation between the master clock terminal device and the access network device; Uploading the second clock deviation to the application layer; or, The second clock deviation is sent to a unified data management network element for storage.

11. A timing method, characterized in that: Applied to a second terminal device; the method comprises: A first message is sent to a first terminal device; the first message includes a timing mode supported by the second terminal device; the timing mode supported by the second terminal device is used by the first terminal device to provide timing for the second terminal device.

12. The method according to claim 11, characterized in that The timing modes supported by the second terminal device include one or more of broadcast timing, unicast timing, precision time protocol PTP timing and base station timing; The timing modes supported by the first terminal device include one or more of broadcast timing, unicast timing, precision time protocol PTP timing and base station timing.

13. The method according to claim 11 or 12, characterized in that: The method further comprises: Receiving a PTP message sent by the first terminal device through a direct link between the first terminal device and the second terminal device; Among them, the PTP message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is the identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to perform clock synchronization based on the first time information and the first clock deviation after obtaining the first clock deviation with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

14. The method according to claim 11 or 12, characterized in that: The method further comprises: Receive at least one sidelink broadcast message; wherein, the at least one sidelink broadcast message includes a sidelink broadcast message sent by the first terminal device; the sidelink broadcast message sent by the first terminal device includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to perform clock synchronization based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group; or, Receive a first unicast message sent by the first terminal device through a direct link between the first terminal device and the second terminal device; wherein the first unicast message includes first time information and a group identifier; the first time information is added by the first terminal device; the group identifier is an identifier of the group to which the second terminal device belongs; the first time information is used for the second terminal device to perform clock synchronization based on the first time information and the propagation delay after obtaining the propagation delay with the first terminal device; the group identifier is used to indicate that the first time information is the master clock time of the group.

15. The method according to claim 14, characterized in that The propagation delay is obtained by the first terminal device and the second terminal device based on an RTT measurement mechanism.

16. The method according to any one of claims 13 to 15, characterized in that Before sending the first message to the first terminal device, the method further includes: Receiving a direct communication request from a first terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and information of a ProSe service; the identifier of the first terminal device is used to identify a terminal device that initiates a direct link establishment process; the information of the ProSe service is used to identify that a ProSe timing service needs to be performed by establishing a direct link; The sending a first message to the first terminal device includes: When it is determined that the identifier of the at least one target terminal device includes the identifier of the second terminal device, the first message is sent to the first terminal device.

17. The method according to any one of claims 13 to 15, characterized in that Before sending the first message to the first terminal device, the method further includes: Receiving a direct communication request from a first terminal device; the direct communication request includes an identifier of the first terminal device, an identifier of at least one target terminal device, and information of a ProSe service; the identifier of the first terminal device is used to identify a terminal device that initiates a direct link establishment process; the information of the ProSe service is used to identify that a ProSe timing service needs to be performed by establishing a direct link; The sending a first message to the first terminal device includes: When it is determined that the identifier of the at least one target terminal device does not include the identifier of the second terminal device and the ProSe timing service is required, the first message is sent to the first terminal device.

18. The method according to claim 16 or 17, characterized in that The direct communication request is sent when the path preference corresponding to the information of the ProSe service is the PC5 interface.

19. The method according to any one of claims 13 to 17, characterized in that: The method further comprises: When it is determined that the direct link with the first terminal device is disconnected, a relay terminal device is determined from the group, and a direct link is established with the relay terminal device, so that the relay terminal device provides time to the second terminal device after being provided time by the first terminal device.

20. The method according to claim 16 or 17, characterized in that The second terminal device is within the coverage of the wireless access network; when the direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with the terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the information of the ProSe service is a Uu interface, the method further includes: Acquire a second clock deviation from the application layer; the second clock deviation is the clock deviation between the master clock terminal device and the access network device; Receiving a system information block message sent by an access network device; the system information block message includes second time information of the access network device; Performing clock synchronization with the master clock terminal device based on the second clock deviation and the second time information; or, Sending a second message to the application function network element; the second message is used to request to enable the access network device to provide timing for the second terminal device; receiving a second unicast message and a broadcast message sent by the access network device; the second unicast message includes a second clock deviation; the second clock deviation is the clock deviation between the master clock terminal device and the access network device; the broadcast message includes second time information of the access network device; the second clock deviation is obtained by the access network device from a unified data management network element; Clock synchronization is performed with the master clock terminal device based on the second clock deviation and the second time information.

21. The method according to claim 20, characterized in that The second message includes the identifier of the second terminal device and the group identifier; the identifier of the second terminal device is used to identify the terminal device requesting time synchronization from the access network device; the group identifier is used to indicate that the second terminal device needs to obtain the clock deviation between the master clock time of the group and the time of the access network device.

22. The method according to claim 20, characterized in that The second unicast message also includes the group identifier; the group identifier is used to indicate that the second clock deviation is the clock deviation between the master clock time of the group and the time of the access network device.

23. A timing method, characterized in that: Applied to access network equipment; the method comprises: Acquire a second clock deviation from a master clock terminal device of a group to which the second terminal device belongs; sending the second clock deviation to the first terminal device, so that the first terminal device uploads the second clock deviation to the application layer; or, The second clock deviation is sent to the unified data management network element for storage.

24. The method according to claim 23, characterized in that The sending the second clock deviation to a unified data management network element for storage includes: sending the second clock deviation to an access and mobility management function network element, so that the access and mobility management function network element sends the second clock deviation to the unified data management network element for storage; or, The second clock deviation is sent to a time-sensitive communication and time synchronization function network element, so that the time-sensitive communication and time synchronization function network element sends the second clock deviation to the unified data management network element for storage.

25. The method according to claim 24, characterized in that The method further comprises: Receive a third message sent by the access and mobility management function network element; the third message includes an identifier of the second terminal device and a group identifier of the group; the identifier of the second terminal device is used to identify the terminal device requesting timing of the access network device; the group identifier is used to indicate that the second terminal device needs to obtain the clock deviation between the master clock time of the group and the time of the access network device; the second terminal device is within the coverage of the wireless access network; the direct link between the second terminal device and the first terminal device is disconnected and a direct link cannot be established with the terminal devices in the group, or the second terminal device only supports base station timing, or the path preference corresponding to the information of the ProSe service is the Uu interface; Acquire the second clock deviation from the unified data management network element based on the group identifier; Sending a second unicast message to the second terminal device; the second unicast message includes the second clock deviation and the group identifier; the group identifier is used to indicate that the second clock deviation is the clock deviation between the master clock time of the group and the time of the access network device; Sending a broadcast message; the broadcast message includes the second time information of the access network device.

26. The method according to claim 25, characterized in that The third message is sent by the access and mobility management function network element when the time-sensitive communication and time synchronization function network element confirms that the second message sent by the second terminal device to the application function network element is valid; the second message is used to request to enable the access network device to provide time for the second terminal device.

27. The method according to any one of claims 23 to 26, characterized in that The second clock deviation is obtained by the access network device and the master clock terminal device based on the RTT measurement mechanism.

28. A timing device, characterized in that: The method comprises a module for executing the method according to any one of claims 1 to 10, or comprises a module for executing the method according to any one of claims 11 to 22, or comprises a module for executing the method according to any one of claims 23 to 27.

29. An electronic device, characterized in that: It includes a processor, a memory, a communication interface, and one or more programs, wherein the one or more programs are stored in the memory and are configured to cooperate with the communication interface when executed by the processor to implement the method as described in any one of claims 1-10, claims 11-22 or claims 23-27.

30. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for execution by a device, and when the computer program is executed, the method of any one of claims 1-10, claims 11-22, or claims 23-27 is implemented.

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