A clock synchronization guarantee method and device

Abstract

This application relates to the field of communication technology and discloses a clock synchronization guarantee method and apparatus, which can guarantee clock synchronization between a terminal device and a user plane function network element when their clocks are out of sync. The method includes: a clock management network element receiving a General Precision Time Protocol (gPTP) clock synchronization request from an application function network element, the gPTP clock synchronization request including the identifier of the target user plane function network element and the identifier of the target terminal device; when the clocks of the target user plane function network element and the target terminal device are out of sync, the clock management network element obtains the clock deviation between the target user plane function network element and the target access network device, the target access network device being the timing access network device for the target terminal device; the clock management network element sends the clock deviation to the target user plane function network element or the target terminal device, the clock deviation being used by the target access network device or the target terminal device for clock synchronization.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a clock synchronization guarantee method and apparatus. Background Art

[0002] The timing function of 5G networks is a network function that can be opened to external devices to provide timing information. The timing openness of 5G networks can be activated and deactivated by application function (AF) network elements. Currently, in the discussion phase of the Industrial Internet requirements, the service requirement to support time-sensitive networks (TSNs) has been clearly defined. For fields such as communications and industrial control, most tasks are based on a time reference; therefore, accurate clock synchronization is a fundamental requirement. TSNs must first solve the problems of clock synchronization and latency calculation in the network to ensure high consistency in task scheduling across the entire network. For many vertical industry users, they hope that 5G networks can replace traditional wired access to TSNs. When terminal devices access TSNs through a 5G communication system, they should be able to implement the existing control functions of TSNs while meeting various performance indicators for TSN data transmission.

[0003] The basic idea of ​​the TSN clock synchronization scheme is as follows: Terminal devices, access network devices (such as gNBs), and user plane function (UPF) network elements in a 5G communication system are first synchronized with the 5G communication system clock. The TSN clock information is carried in the general precise time protocol (gPTP) synchronization message and transmitted to the device-side TSN translator (DS-TT) via the network-side TSN translator (NW-TT). The NW-TT is typically a functional module within a UPF network element, while the DS-TT is typically a functional module within a terminal device. The DS-TT in the terminal device calculates the residence time of the gPTP synchronization message in the 5G communication system based on the timestamp information in the gPTP synchronization message. Finally, based on the TSN clock information carried in the gPTP synchronization message and the residence time in the 5G communication system, it obtains the accurate TSN clock information.

[0004] As a component of the TSN (Transmission Networking System) in 5G communication systems, 5G clock synchronization is crucial for TSN clock synchronization. Currently, TSN clock synchronization schemes rely on the clock synchronization of access network equipment and user plane functional network elements that provide timing for terminal devices. However, when 5G clock malfunctions or handovers occur, the clocks of the access network equipment and user plane functional network elements providing timing for terminal devices may become out of sync, leading to inaccurate dwell times for gPTP synchronization messages. Therefore, ensuring clock synchronization between terminal devices and user plane functional network elements when their clocks are out of sync becomes a problem to be solved. Summary of the Invention

[0005] This application provides a clock synchronization guarantee method and apparatus, which can guarantee clock synchronization between the terminal device and the user plane functional network element when the clocks of the access network device that provides time synchronization to the terminal device and the user plane functional network element are not synchronized.

[0006] In a first aspect, embodiments of this application provide a clock synchronization guarantee method. This method can be executed by a clock management network element, or by a component of the clock management network element (such as a processor, chip, or chip system), or by a logic module or software that can implement all or part of the functions of the clock management network element. The method includes: a clock management network element receiving a Generalized Precision Time Protocol (gPTP) clock synchronization request from an application function network element. The gPTP clock synchronization request includes clock synchronization parameters. The clock management network element can obtain the identifier of the target user plane function network element and the identifier of the target terminal device when transmitting the gPTP synchronization message during TSN clock synchronization from the clock synchronization parameters. If the clocks of the target user plane function network element and the target terminal device are not synchronized, the clock management network element obtains the clock deviation between the target user plane function network element and the target access network device, where the target access network device is the timing access network device of the target terminal device. The clock management network element sends the clock deviation to the target user plane function network element, and the clock deviation is used by the target user plane function network element to synchronize with the clock of the target terminal device. Alternatively, the clock management network element sends the clock deviation to the target terminal device, and the clock deviation is used by the target terminal device to synchronize with the clock of the user plane function network element.

[0007] Using the above method, when the clocks of the target access network device and the target user plane function network element are out of sync, causing the clocks of the target terminal device and the target user plane function network element to be out of sync, the clock management network element can achieve clock synchronization between the target terminal device and the target user plane network element by obtaining the clock deviation between the target user plane function network element and the target access network device and instructing it to the target terminal device or the target user plane network element, thereby supporting TSN clock synchronization.

[0008] In one possible design, the clock management network element acquires the clock deviation between the target user plane function network element and the target access network device, including: the clock management network element sending a first clock deviation measurement indication to the target user plane function network element, the first clock deviation measurement indication including the identifier of the target access network device, used to instruct the target user plane function network element to initiate the measurement of the clock deviation between the target user plane function network element and the target access network device; the clock management network element receiving a first clock deviation measurement indication response from the target user plane function network element, the first clock deviation measurement indication including the clock deviation between the target user plane function network element and the target access network device.

[0009] In the above design, the clock management network element can instruct the target user plane function network element to initiate the measurement of the clock deviation relative to the target access network device, such as initiating a round trip time (RTT) operation, to obtain the clock deviation between the target user plane function network element and the target access network device. This is simple to implement and can accurately determine the clock deviation, which helps to achieve clock synchronization of the target terminal device or the target user plane network element.

[0010] In one possible design, when multiple clocks are used by the target user plane function network element, the first clock deviation measurement indication also includes the identifier of the target clock, and the first clock deviation measurement indication response also includes the identifier of the target clock; wherein, the target clock is the clock determined by the clock management network element among multiple clocks for the target user plane function network element to use for clock synchronization with the target access network equipment or the target terminal equipment.

[0011] In the above design, when multiple clocks are used in the target user plane function network element, the clock for clock synchronization between the target user plane function network element and the target access network device or the target terminal device can be specified. This enables clock synchronization between the target terminal device and the target user plane function network element when the target user plane function network element is operating in multiple clock domains.

[0012] In one possible design, the clock management network element acquires the clock deviation between the target user plane function network element and the target access network device, including: the clock management network element sending a second clock deviation measurement indication to the target access network device, the second clock deviation measurement indication including the identifier of the target user plane function network element, used to instruct the target access network device to initiate a measurement of the clock deviation between the target user plane function network element and the target access network device; the clock management network element receiving a second clock deviation measurement indication response from the target access network device, the second clock deviation measurement indication response including the clock deviation between the target user plane function network element and the target access network device.

[0013] In the above design, the clock management network element can instruct the target access network device to initiate the measurement of the clock deviation relative to the target user plane functional network element, such as by initiating an RTT operation, to obtain the clock deviation between the target user plane functional network element and the target access network device. This is simple to implement and can accurately determine the clock deviation, which helps to achieve clock synchronization of the target terminal device or the target user plane network element.

[0014] In one possible design, when multiple clocks are used by the target user plane function network element, the second clock deviation measurement indication also includes the identifier of the target clock, and the second clock deviation measurement indication response also includes the identifier of the target clock; wherein, the target clock is the clock determined by the clock management network element from among multiple clocks for the user plane function network element to use for clock synchronization with the target access network equipment or the target terminal equipment.

[0015] Optionally, the method further includes: the clock management network element sending a second clock deviation measurement response indication to the target user plane function network element, the second clock deviation measurement response indication including the identifier of the target clock and the identifier of the target access network device, used to instruct the target user plane function network element to respond to the clock deviation measurement initiated by the target access network device using the target clock.

[0016] In the above design, when multiple clocks are used in the target user plane function network element, the clock for clock synchronization between the target user plane function network element and the target access network device or the target terminal device can be specified. This enables clock synchronization between the target terminal device and the target user plane function network element when the target user plane function network element is operating in multiple clock domains.

[0017] In one possible design, the clock management network element obtains the clock deviation between the target user plane function network element and the target access network device, including: the clock management network element obtaining the clock attributes of the target user plane function network element's clock and the clock attributes of the target access network device's clock; and the clock management network element determining the clock deviation between the target user plane function network element and the target access network device based on the clock attributes of the target user plane function network element's clock and the clock attributes of the target access network device's clock.

[0018] In the above design, the clock management network element can maintain the clock information of the target user plane function network element and the target access network equipment, and can determine the clock deviation between the target user plane function network element and the target access network equipment based on the clock attributes of the target user plane function network element clock and the target access network equipment clock (such as the deviation from the set reference clock such as Universal Time Coordinated (UTC)), which can reduce signaling overhead.

[0019] In one possible design, the clock management network element determines that the clocks of the target user plane function network element and the target terminal device are out of sync when at least one of the following conditions is met: the clock management network element receives a clock switching notification from the target user plane function network element; the clock management network element receives a clock switching notification from the target access network device; the clock management network element receives a clock switching notification from the network management network element indicating that the clocks of the target user plane function network element or the target access network device have switched; the clock management network element receives a clock asynchronization notification from the target terminal device, the clock asynchronization notification indicating that the clocks of the target terminal device and the target user plane function network element are out of sync; the clock management network element receives a clock asynchronization notification from the target user plane function network element, the clock asynchronization notification indicating that the clocks of the target user plane function network element and the target terminal device are out of sync.

[0020] Secondly, embodiments of this application provide a clock synchronization guarantee method. This method can be executed by a clock management network element, or by a component of the clock management network element (such as a processor, chip, or chip system), or by a logic module or software that can implement all or part of the functions of the clock management network element. The method includes: a clock management network element receiving a gPTP clock synchronization request from an application function network element. The gPTP clock synchronization request includes clock synchronization parameters. The clock management network element can obtain from the clock synchronization parameters the identifier of the target user plane function network element transmitting the gPTP synchronization message, the identifier of the target terminal device, and the gPTP clock synchronization error budget when performing TSN clock synchronization. If the clock synchronization parameters do not contain a gPTP clock synchronization error budget, the clock management network element can use the default configured gPTP clock synchronization error budget. The clock management network element determines whether the clock synchronization requirement is met based on the clock deviation between the target user plane function network element and the target access network device, the gPTP clock synchronization error budget, and the existing available timing error budget of the target access network device for the target terminal device. The target access network device is the timing access network device for the target terminal device. If the gPTP clock synchronization error budget is large, even if the target user plane function network element and the target access network device... If the clock skew introduced by the clock asynchrony, plus the timing error budget of the access network device to the target terminal device, and the deviation between the core network and the device side during gPTP clock synchronization implementation, are still within the required gPTP clock synchronization error budget, then the clock synchronization management network element will implement gPTP clock synchronization according to the existing method. If the gPTP clock synchronization error budget is relatively small, and the clock skew introduced by the clock asynchrony between the target user plane function network element and the target access network device, plus the timing error budget of the access network device to the target terminal device, and the deviation between the core network and the device side during gPTP clock synchronization implementation exceed the required gPTP clock synchronization error budget, then the clock management network element may further update the available timing error budget of the target access network device to the target terminal device. When the available timing error budget is within the timing error budget supported by the target access network device, the clock management network element sends the available timing error budget to the target access network device, and the available timing error budget is used for timing synchronization between the target access network device and the terminal device. In one possible implementation, the available timing error budget supported by the target access network device is reported to the clock management network element or to the access and management network element when the target access network device sends an NG setup request. The clock management network element then queries the access and management network element or notifies the clock management unit from the access and management network element. Here, NG represents the interface between the access network and the core network.

[0021] Optionally, the method further includes: when the available timing error budget is not within the timing error budget supported by the target access network device, or when the application function network element requires internal clock synchronization of the 5G communication system, or when the 5G communication system cannot meet the gPTP clock synchronization error budget, the clock management network element sends a clock synchronization request failure notification to the application function network element. The clock synchronization request failure notification is used to notify that the requested gPTP clock synchronization has failed, that is, TSN clock synchronization has failed.

[0022] Using the above method, when the clocks of the target access network equipment and the target user plane function network element are out of sync, causing the clocks of the target terminal equipment and the target user plane function network element to be out of sync, the clock management network element can flexibly adjust the available timing error budget of the air interface according to the requirements of gPTP clock synchronization error budget, so as to enable the target user plane function network element and the target terminal equipment to meet the clock synchronization requirements, thereby supporting TSN clock synchronization.

[0023] Thirdly, embodiments of this application provide a clock synchronization guarantee method. This method can be executed by a clock management network element, by a component of the clock management network element (e.g., a processor, chip, or chip system), or by a logic module or software capable of implementing all or part of the clock management network element's functions. The method includes: the clock management network element determining that the clocks of a target user plane function network element and a target terminal device are out of sync; the clock management network element sending a first timing indication to a target access network device and a first multi-domain clock indication to the target user plane function network element, wherein the first timing indication includes an identifier of the target user plane function network element, used to instruct the target access network device to provide timing to the target user plane function network element; the first multi-domain clock indication includes an identifier of the target access network device and an identifier of the target terminal device, used to instruct the target user plane function network element to receive the timing from the target access network device and to synchronize with the target terminal device using the clock from the target access network device. Clock synchronization; or, the clock management network element sends a second timing indication to the target user plane function network element and a second multi-domain clock indication to the target access network device, wherein the second timing indication includes the identifier of the target access network device, used to instruct the target user plane function network element to synchronize the time of the target access network device, and the second multi-domain clock indication includes the identifier of the target user plane function network element and the identifier of the target terminal device, used to instruct the target access network device to receive the timing from the target user plane function network element and to synchronize the time of the target terminal device using the clock from the target user plane function network element; wherein, the target access network device is the timing access network device of the target terminal device.

[0024] Using the above method, when the clocks of the target access network device and the target user plane function network element are out of sync, causing the clocks of the target terminal device and the target user plane function network element to be out of sync, the clock management network element can instruct the target access network device or the target user plane function network element to accept the time synchronization from the other party, thereby supporting the clock synchronization of TSN.

[0025] In one possible design, the clock management network element determines that the clocks of the target user plane function network element and the target terminal device are out of sync when at least one of the following conditions is met: the clock management network element receives a clock switching notification from the target user plane function network element; the clock management network element receives a clock switching notification from the target access network device; the clock management network element receives a clock switching notification from the network management network element indicating that the clocks of the target user plane function network element or the target access network device have switched; the clock management network element receives a clock asynchronization notification from the target terminal device, the clock asynchronization notification indicating that the clocks of the target terminal device and the target user plane function network element are out of sync; the clock management network element receives a clock asynchronization notification from the target user plane function network element, the clock asynchronization notification indicating that the clocks of the target user plane function network element and the target terminal device are out of sync.

[0026] Fourthly, embodiments of this application provide a communication device that performs the functions described in the first to third aspects above. These functions can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the aforementioned functions, such as an interface unit and a processing unit.

[0027] In one possible design, the device can be a chip or an integrated circuit.

[0028] In one possible design, the device includes a memory and a processor, the memory for storing instructions executed by the processor, and when the instructions are executed by the processor, the device can perform the methods described in the first to third aspects above.

[0029] In one possible design, the device could be a clock management network element.

[0030] Fifthly, embodiments of this application provide a communication device including an interface circuit and a processor, wherein the processor and the interface circuit are coupled to each other. The processor implements the methods described in the first to third aspects through logic circuits or execution instructions. The interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor, or to send signals from the processor to other communication devices outside the communication device. It is understood that the interface circuit can be a transceiver, a transceiver terminal, or an input / output interface.

[0031] Optionally, the communication device may also include a memory for storing instructions executed by the processor, or storing input data required by the processor to execute instructions, or storing data generated after the processor executes instructions. The memory may be a physically independent unit, or it may be coupled to the processor, or the processor may include the memory.

[0032] Sixthly, embodiments of this application provide a computer-readable storage medium storing a computer program or instructions, which, when executed, can implement the methods described in the first to third aspects.

[0033] In a seventh aspect, embodiments of this application also provide a computer program product, including a computer program or instructions, which, when executed, can implement the methods described in the first to third aspects.

[0034] Eighthly, embodiments of this application also provide a chip coupled to a memory for reading and executing programs or instructions stored in the memory to implement the methods described in the first to third aspects.

[0035] The technical effects that can be achieved by aspects four through eight above are the same as those that can be achieved by aspects one through three above, and will not be repeated here. Attached Figure Description

[0036] Figure 1A A schematic diagram of a service-based network architecture for a 5G communication system;

[0037] Figure 1B A schematic diagram of a 5G communication system based on a point-to-point interface;

[0038] Figure 2 A schematic diagram of the logical architecture for 5G communication systems to access the TSN system;

[0039] Figure 3 This is one of the schematic diagrams of the clock synchronization guarantee method provided in the embodiments of this application;

[0040] Figure 4 A schematic diagram of time round-trip operation provided for embodiments of this application;

[0041] Figure 5 This is the second schematic diagram of the clock synchronization guarantee method provided in the embodiments of this application;

[0042] Figure 6 This is the third schematic diagram of the clock synchronization guarantee method provided in the embodiments of this application;

[0043] Figure 7Schematic diagram four of the clock synchronization guarantee method provided in the embodiments of this application;

[0044] Figure 8 Fifth schematic diagram of the clock synchronization guarantee method provided in the embodiments of this application;

[0045] Figure 9 Sixth schematic diagram of the clock synchronization guarantee method provided in the embodiments of this application;

[0046] Figure 10 This is one of the schematic diagrams of a communication device provided in the embodiments of this application;

[0047] Figure 11 This is a second schematic diagram of a communication device provided in an embodiment of this application. Detailed Implementation

[0048] The technical solutions of this application can be applied to 5G communication systems, as well as to communication systems that evolve after 5G, such as 6th generation (6G) communication systems. The following describes some network architectures to which this application applies, using user equipment (UE) as an example.

[0049] Figure 1A This is a schematic diagram of the network architecture of a 5G communication system based on a service-oriented architecture. Figure 1A The network architecture shown includes a data network (DN) and a carrier network. The functions of some of these network elements are briefly described below.

[0050] The operator network includes one or more of the following network elements: unified data management (UDM) network element, unified data repository (UDR) network element, application function (AF) network element, policy control function (PCF) network element, access and mobility management function (AMF) network element, session management function (SMF) network element, user plane function (UPF) network element, access network (AN) equipment (radio access network (RAN) equipment is used as an example in the figure), time-sensitive communication and time synchronization function (TSCTSF) network element, authentication server function (AUSF) network element (not shown in the figure), network repository function (NRF) network element (not shown in the figure), network exposure function (NEF) network element (not shown in the figure), etc. In the aforementioned operator networks, network elements or equipment other than access network equipment can be referred to as core network elements or core network equipment.

[0051] Access network equipment includes wired access network equipment and wireless access network equipment. Wireless access network equipment can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB) in a 5G mobile communication system, a next-generation base station in a 6th-generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a wireless fidelity (WiFi) system; it can also be a module or unit that performs some of the functions of a base station, for example, a central unit (CU) or a distributed unit (DU). Wireless access network equipment can be a macro base station, a micro base station, an indoor station, a relay node, or a donor node, etc. The embodiments of this application do not limit the specific technologies or equipment forms used in the access network equipment.

[0052] Terminal devices communicating with the RAN include terminals, user equipment (UE), mobile stations, and mobile terminals. The figure uses UE as an example of a terminal device. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc. The embodiments of this application do not limit the specific technologies or device forms used in the terminal devices.

[0053] Access network equipment and terminal equipment can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the access network equipment and terminal equipment.

[0054] Access and Mobility Management (AMM) network elements are control plane network elements provided by the operator's network, responsible for access control and mobility management of terminal equipment accessing the operator's network. These functions include mobility state management, allocation of temporary user identities, authentication, and authorization. In 5G, AMM network elements can be AMF network elements. In future communications such as the 6th generation (6G), AMM network elements may still be AMF network elements or have other names; this application does not impose any limitations.

[0055] The session management function network element is a control plane network element provided by the operator's network, responsible for managing the protocol data unit (PDU) sessions of terminal equipment. A PDU session is a channel used to transmit PDUs; terminal equipment needs to exchange PDUs with the DN through PDU sessions. The session management function network element is responsible for establishing, maintaining, and deleting PDU sessions. Session management functions include session management (such as session establishment, modification, and release, including tunnel maintenance between user plane function network elements and access network equipment), selection and control of user plane function network elements, service and session continuity (SSC) mode selection, roaming, and other session-related functions. In 5G, the session management function network element can be an SMF network element. In future communications such as 6G, the session management function network element can still be an SMF network element, or have other names; this application does not limit this.

[0056] User plane function (UDP) network elements are gateways provided by the operator, serving as the gateway for communication between the operator's network and the DN (Digital Network Provider). UDP network elements include user plane-related functions such as packet routing and transmission, packet inspection, service usage reporting, Quality of Service (QoS) processing, lawful interception, uplink packet inspection, and downlink packet storage. In 5G, UDP network elements can be UPF (User Plane Function) network elements. In future communications such as 6G, UDP network elements may still be UPF network elements, or may have other names; this application does not impose any limitations.

[0057] The Unified Data Management (UDM) network element is a control plane network element provided by the operator, responsible for storing information such as the subscriber permanent identifier (SUPI), credential, security context, and subscription data of subscribed users in the operator's network. This information stored by the UDM network element can be used for authentication and authorization of terminal devices accessing the operator's network. In 5G, the UDM network element can be a UDM network element. In future communications such as 6G, the UDM network element may still be a UDM network element, or it may have other names; this application does not limit this.

[0058] A unified database network element is a control plane network element provided by the operator, which includes the function of storing and retrieving data of various types, such as subscription data, policy data, and application data. In 5G, the unified database network element can be a UDR network element. In future communications such as 6G, the unified database network element can still be a UDR network element, or it may have other names. This application does not limit this.

[0059] Network Open Function (NEF) network elements are control plane network elements provided by the operator. NEF network elements securely expose the operator's network to third parties. When a session management network element needs to communicate with a third-party network element, the NEF network element can act as a relay for this communication. As a relay, the NEF network element can translate the identification information of subscribed users and the identification information of third-party network elements. For example, when the NEF network element sends a subscribed user's SUPI from the operator's network to a third party, it can translate the SUPI into its corresponding external identity identifier. Conversely, when the NEF network element sends an external ID (the third party's network element ID) to the operator's network, it can translate it into a SUPI. In 5G, the NEF network element can be a NEF network element. In future communications such as 6G, the NEF network element can still be a NEF network element, or it may have other names; this application does not limit this.

[0060] Application function network elements are used to convey application-side requirements to the network side, such as QoS requirements or user state event subscriptions. Application function network elements can be third-party functional entities or application servers deployed by operators. In 5G, application function network elements can be AF network elements. In future communications such as 6G, application function network elements can still be AF network elements, or have other names; this application does not limit this. The AF network element includes TSN AF network elements.

[0061] The policy control function (PCF) network element is a control plane function provided by the operator to provide policies for PDU sessions to the session management function (SEM) network element. These policies may include billing-related policies, QoS-related policies, and authorization-related policies. In 5G, the PCF network element can be a PCF network element. In future communications such as 6G, the PCF network element may still be a PCF network element, or may have other names; this application does not limit its scope.

[0062] Network storage function network elements can provide network element discovery capabilities, offering network element information corresponding to the network element type based on requests from other network elements. Network storage function network elements also provide network element management services, such as network element registration, updating, deregistration, and network element status subscription and push. In 5G, network storage function network elements can be NRF network elements. In future communications such as 6G, network storage function network elements can still be NRF network elements, or have other names; this application does not impose any limitations.

[0063] The clock management network element can manage the clock information of one or more clock sources in a 5G network. It can provide the clock information of these sources to external entities through its own ports, such as directly or indirectly providing clock information to terminal devices, access network devices, core network devices, or third-party application function network elements. The clock information represents the time, moment, or point in time. The clock management network element can also select the appropriate timing network element based on the timing request from the requesting party. This timing network element can be, for example, a UPF network element, an access network device, or the clock management network element itself. The clock management network element then instructs the timing network element to provide timing services to the requesting party. In 5G, the clock management network element can be the TSCTSF network element defined by the 3rd Generation Partnership Project (3GPP). In future communications such as 6G, the clock management network element can still be a TSCTSF network element, or it can have other names; this application does not limit its scope.

[0064] A Domain Provider (DN) is a network located outside of the carrier's network. A carrier's network can connect to multiple DNs, and various services can be deployed on a DN, providing data and / or voice services to terminal devices. For example, a DN might be the private network of a smart factory. Sensors installed in the workshop can act as terminal devices, and a control server for these sensors is deployed within the DN. The control server provides services to the sensors. Sensors can communicate with the control server, receive instructions from it, and transmit the collected sensor data back to the control server accordingly. Another example is a DN serving as an internal office network for a company. Employees' mobile phones or computers can act as terminal devices, accessing information and data resources on the company's internal office network.

[0065] Figure 1ANpcf, Nudr, Nudm, Naf, Namf, Nsmf, and Ntsctsf are the service interfaces provided by the aforementioned PCF, UDR, UDM, AF, AMF, SMF, and TSCTSF network elements, respectively, used to invoke the corresponding service operations. N1, N2, N3, N4, and N6 are interface sequence numbers, with the following meanings:

[0066] 1) N1: The interface between the AMF network element and the UE, which can be used to transmit non-access stratum (NAS) signaling (such as QoS rules from the AMF network element) to the UE.

[0067] 2) N2: The interface between the AMF network element and the wireless access network equipment, which can be used to transmit wireless bearer control information from the core network side to the wireless access network equipment.

[0068] 3) N3: The interface between the wireless access network device and the UPF network element, mainly used to transmit uplink user plane data and / or downlink user plane data between the wireless access network device and the UPF network element.

[0069] 4) N4: The interface between SMF network elements and UPF network elements. It can be used to transmit information between the control plane and the user plane, including the distribution of forwarding rules, QoS rules, traffic statistics rules, etc. from the control plane to the user plane, as well as the reporting of information from the user plane.

[0070] 5) N6: The interface between the UPF network element and the DN, used to transmit uplink user data streams and / or downlink user data streams between the UPF network element and the DN.

[0071] Figure 1B This is a schematic diagram of a 5G communication system based on a point-to-point interface. For a description of the functions of the network elements, please refer to [link / reference needed]. Figure 1A The functions of the corresponding network elements will not be described in detail here. Figure 1B and Figure 1A The main difference is: Figure 1A The interfaces between the various control plane network elements are service-oriented interfaces. Figure 1B The interfaces between the various control plane network elements are point-to-point interfaces.

[0072] exist Figure 1B In the architecture shown, the interface names and functions between the various network elements are as follows:

[0073] 1) The meanings of interfaces N1, N2, N3, N4 and N6 can be found in the previous description.

[0074] 2) N5: The interface between the AF network element and the PCF network element, which can be used for application service request distribution and network event reporting.

[0075] 3) N7: The interface between PCF network elements and SMF network elements, which can be used to issue protocol data unit (PDU) session granularity and service data flow granularity control strategies.

[0076] 4) N8: The interface between the AMF network element and the UDM network element. It can be used by the AMF network element to obtain access and mobility management related subscription data and authentication data from the UDM network element, as well as by the AMF network element to register terminal device mobility management related information with the UDM network element.

[0077] 5) N9: User plane interface between UPF network elements, used to transmit uplink user data streams and / or downlink user data streams between UPF network elements.

[0078] 6) N10: The interface between SMF network elements and UDM network elements. It can be used for SMF network elements to obtain session management-related subscription data from UDM network elements, and for SMF network elements to register terminal device session-related information with UDM network elements.

[0079] 7) N11: The interface between SMF network elements and AMF network elements. It can be used to transmit PDU session tunnel information between radio access network devices and UPF network elements, transmit control messages sent to terminal devices, and transmit radio resource control information sent to radio access network devices.

[0080] 8) N15: The interface between PCF network elements and AMF network elements, which can be used to issue terminal equipment policies and access control related policies.

[0081] 9) N35: The interface between UDM network elements and UDR network elements, which can be used by UDM network elements to obtain user subscription data information from UDR network elements.

[0082] 10) N36: The interface between PCF network elements and UDR network elements, which can be used by PCF network elements to obtain policy-related contract data and application data related information from UDR network elements.

[0083] It is understood that the aforementioned network element or function can be a network component in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the aforementioned network element or function can be implemented by one device, multiple devices working together, or a functional module within a single device; this application embodiment does not specifically limit this.

[0084] The logical architecture diagram for accessing the TSN system through a 5G communication system can be seen as follows: Figure 2 As shown. In Figure 2 The image only shows a portion of the network elements in the 5G architecture (i.e., base station, UE, UPF). Figure 2 In this system, network elements such as base stations, UEs, and UPFs, along with NW-TT and DS-TT, are used as a logical TSN bridge (referred to as the 5G TSN bridge) to connect TSN system 1 and TSN system 2.

[0085] NW-TT, used to connect to the TSN system 1 on the network side, is typically a functional module within a UPF network element. It's used to introduce TSN data into the 5G network. Because it receives gPTP synchronization messages from the TSN system, it can be understood as a slave interface. NW-TT needs to perform functions such as measuring latency and frequency deviation with the TSN bridge and adding entry timestamps (Tsi) to the gPTP synchronization messages.

[0086] DS-TT, used to connect the TSN system 2 on the terminal device side, can be a functional module within the terminal device or can connect to the terminal device via wired or wireless means. It is used to input TSN data into the TSN network. Because it needs to send gPTP synchronization messages to the TSN network, it can be understood as the master interface. DS-TT needs to work with the end station to complete latency and frequency deviation measurements, adding an egress timestamp (Tsc) to the gPTP synchronization messages received from the terminal device, and then calculating the internal forwarding latency.

[0087] The TSN system (including TAN system 1 on the network side and TSN system 2 on the device side) operates in the TSN working domain. In the TSN working domain, TSN GM represents the clock source of the TSN system. TSN GM can be a factory-defined clock source and does not necessarily need to be consistent with global positioning system (GPS) or universal time coordinated (UTC). The TSN bridge is mainly used to send gPTP synchronization messages to the 5G time domain so that terminal devices (or their corresponding end stations) in the 5G communication system can synchronize with the TSN system time.

[0088] The 5G time domain in which a 5G communication system operates is a Precise Time Protocol (PTP) node for the TSN system, meaning it is PTP-compatible 5G transport. Therefore, devices within the 5G time domain need to operate on the same clock. 5G GM represents the clock source of the 5G communication system, typically using GPS.

[0089] Specifically, during TSN system time synchronization, the NW-TT in the UPF network element receives the gPTP synchronization message from the TSN bridge and adds an ingress timestamp Tsi to the gPTP synchronization message according to the 5G time. Then, the gPTP synchronization message is sent to the terminal device through the access network equipment (such as a base station) in the 5G communication system. The DS-TT in the terminal device adds an egress timestamp Tsc to the gPTP synchronization message according to the 5G time, and determines the forwarding delay from the UPF network element to the terminal device based on the ingress timestamp Tsi and the egress timestamp Tsc. Thus, the time synchronization between the terminal device and the TSN network is achieved based on the forwarding delay and the TSN clock information recorded in the gPTP synchronization message.

[0090] Optionally, taking NW-TT as the importing node and DS-TT as the exporting node as an example, NW-TT can also add the link delay of the TSN node to the correction field of the gPTP synchronization message. This link delay indicates the delay from when TSN system 1 sends the gPTP synchronization message to when the gPTP synchronization message arrives at NW-TT. Additionally, NW-TT can calculate a new cumulative rate ratio to replace the original TSN node rate ratio recorded in the gPTP synchronization message. This cumulative rate ratio can be understood as the conversion ratio between 5G GM time and TSN GM time. When calculating the residence time, DS-TT can convert the residence time into the time in TSN GM based on the cumulative rate ratio and add it to the correction field. The terminal device or endpoint receiving the gPTP synchronization message can then determine the accurate TSN clock information based on the TSN clock information in the gPTP synchronization message, the converted residence time, and the link delay.

[0091] Therefore, time synchronization between the terminal device and the TSN relies on the time synchronization of the 5G communication system. However, when the 5G clock malfunctions or switches, the clocks of the access network equipment and user plane function network elements that provide time synchronization for the terminal device may become out of sync. In this case, the dwell time of the obtained gPTP synchronization message will be inaccurate, failing to support TSN clock synchronization. Therefore, ensuring clock synchronization between the terminal device and user plane function network elements when their clocks are out of sync becomes a problem to be solved. This application aims to provide a clock synchronization guarantee method that can ensure clock synchronization between the terminal device and user plane function network elements even when their clocks are out of sync.

[0092] The following describes the embodiments of this application in detail, taking the terminal device as UE, the access network device as RAN, and the clock management network element, user plane function network element, application function network element, etc. as TSCTSF network element, UPF network element, AF network element, etc. in 5G as examples, in conjunction with the accompanying drawings.

[0093] Figure 3 A clock synchronization guarantee method provided in this application embodiment includes:

[0094] S301: The TSCTSF network element receives a gPTP clock synchronization request from the AF network element.

[0095] The gPTP clock synchronization request includes clock synchronization parameters. The TSCTSF network element can obtain the identifier of the target UPF network element and the identifier of the target UE from the clock synchronization parameters. For example, the identifier of the target UE and the identifier of the target UPF network element are respectively the identity document (ID) of the target UE and the ID of the target UPF network element.

[0096] Specifically, the AF network element can determine the target UE and target UPF network element for gPTP clock synchronization based on the network-side TSN system and device-side TSN system requiring gPTP clock synchronization, as well as the connection status between the network-side TSN system and the UPF network element, and the connection status between the device-side TSN system and the UE. After determining the target UE and target UPF network element, the AF network element can send a gPTP clock synchronization request to the TSCTF network element to activate the 5G network's timing open capability.

[0097] After receiving a gPTP clock synchronization request from the AF network element, the TSCTSF network element will determine whether the clocks of the target UPF network element and the target UE are synchronized.

[0098] Specifically, the TSCTSF network element can maintain the clock attributes of each RAN device clock managed by the TSCTSF network element, as well as the clock attributes of each managed UPF network element clock. The clock attributes can include the clock identifier, clock class, clock offset from a set reference clock (offsetScaledLogVariance), clock accuracy, and other clock quality information. These clock attributes of the RAN devices and UPF network elements managed by the TSCTSF network element can be reported by the RAN devices and UPF network elements when establishing a connection with the TSCTSF network element, or they can be reported by the RAN devices and UPF network elements according to a set period or a set policy. When the TSCTSF network element detects that the identifier of the target RAN device clock used for timing the target UE is different from the identifier of the target UPF network element clock, the TSCTSF network element can determine that the target UPF network element and the target UE are using different clocks, indicating that their clocks are out of sync; otherwise, it determines that their clocks are synchronized.

[0099] In some implementations, when the target UE or target UPF network element detects a difference in the clock identifiers recorded in the timestamps of the transmitted gPTP synchronization messages, it can send a clock asynchronization notification to the TSCTSF network element, including the identifiers of the target UE and the target UPF network element. Upon receiving this notification, the TSCTSF network element can also determine that the clocks of the corresponding target UE and target UPF network element are out of sync. The clock asynchronization notification sent by the target UE may also include the identifier of the gPTP clock synchronization instance or the target UE's port status information, such as a port management information container (PMIC). Similarly, the clock asynchronization notification sent by the target UPF network element may include the identifier of the gPTP clock synchronization instance or the target UPF network element's port status information, such as a user plane management information container (UMIC). When the clock management network element receives this information, it can also determine the change in the clock synchronization status of the target UE or target UPF.

[0100] In addition, for a target UE and target UPF network element whose clock synchronization has been determined, when the TSCTSF network element receives a clock switching notification sent by the target RAN device or target UPF network element that provides timing for the target UE after a clock switch, or receives a clock switching notification sent by the network management network element to the TSCTSF network element after detecting a clock switch in the target RAN device or target UPF network element, the TSCTSF network element can also determine that the clocks of the target RAN device and target UPF network element are out of sync, as well as that the clocks of the target UE that receives timing from the target RAN device and target UPF network element are out of sync.

[0101] Additionally, when the TSCTSF network element receives the clock attributes of the target RAN device or the target UPF network element, it can also determine whether the two are synchronized. For example, if the clocks of the target RAN device and the target UPF network element were previously synchronized, but the target RAN device's clock is in a holdover state due to a clock failure, they will still become out of sync. In this case, the clock management network element can also determine that the clocks of the target RAN device and the target UPF network element are out of sync, as well as that the clocks of the target UE and the target UPF network element that are being timed by the target RAN device are out of sync.

[0102] S302: When the clocks of the target UPF network element and the target UE are out of sync, the TSCTSF network element obtains the clock deviation between the target UPF network element and the target RAN device, where the target RAN device is the timing RAN device of the target UE.

[0103] In one possible implementation, the TSCTSF network element can determine the clock offset between the target UPF network element and the target RAN device by using the clock attributes of the target UPF network element's clock and the target UPF network element's clock. As an example: if the target UPF network element uses 5G GM1 and 5G GM2, and the clock offsets of 5G GM1 and 5G GM2 from the set reference clock are both clock offsets from UTC, the TSCTSF network element can determine the clock offset between the target UPF network element and the target RAN device based on the clock offsets of 5G GM1 and UTC, and the clock offsets of 5G GM2 and UTC.

[0104] It is important to understand that the clock deviation between the target UPF network element and the target RAN device can be described as the clock deviation of the target RAN device relative to the target UPF network element, and the clock deviation of the target UPF network element relative to the target RAN device. As an example: at a certain moment, the clock of the target UPF network element (5G GM1) is 00:00:01, and the clock of the target RAN device (5G GM2) is 00:00:00. Then, the clock deviation of the target UPF network element relative to the target RAN device is 00:00:00 - 00:00:01 (5G GM2 - 5G GM1), which is -1 second; the clock deviation of the target RAN device relative to the target UPF network element is 00:00:01 - 00:00:00 (5G GM1 - 5G GM2), which is 1 second. In the subsequent description of the embodiments in this application, the clock deviation between the target UPF network element and the target RAN device will be used as the clock deviation of the target RAN device relative to the target UPF network element for explanation.

[0105] In other implementations, the TSCTSF network element can also obtain the clock offset between the target UPF network element and the target RAN device by instructing the target UPF network element to perform a round trip time (RTT) operation with the target RAN device.

[0106] like Figure 4 The diagram shown is a schematic diagram of RTT operation between the target RAN device and the target UPF network element according to an embodiment of this application:

[0107] Step 1: The target RAN device sends a request message to the target UPF network element at time t1 and records the time t1 when the request message is sent;

[0108] Step 2: The target UPF network element receives the request message at time t2 and timestamps t2 on the request message;

[0109] Step 3: The target UPF network element sends a response message at time t3 and records the time t3 when the response message is sent. The response message carries a timestamp t2.

[0110] Step 4: The target RAN device receives the response message at time t4 and timestamps t4 on the response message.

[0111] In addition, after sending the response message, the target UPF network element will also send a follow-up message to the target RAN device. This follow-up message carries the time t3 when the target UPF network element sent the response message. At this point, the target RAN device obtains the time t1 when the request message was sent, the time t2 when the target UPF network element received the request message, the time t3 when the target UPF network element sent the response message, and the time t4 when the target RAN device received the response message. Using [(t2-t1)-(t4-t3)] / 2, the target RAN device can determine the clock offset between itself and the target UPF network element. Using [(t2-t1)+(t4-t3)] / 2, the target RAN device can also calculate the delay between itself and the target UPF network element.

[0112] As an example, a TSCTSF network element can send a first clock deviation measurement indication to a target UPF network element. This first clock deviation measurement indication includes the identifier of the target RAN device, instructing the target UPF network element to initiate a measurement of the clock deviation between the target UPF network element and the target RAN device. Upon receiving the first clock deviation measurement indication, the target UPF network element can initiate an RTT operation to the target RAN device to measure the clock deviation between them. After completing the clock deviation measurement, the target UPF network element can send a first clock deviation measurement indication response to the TSCTSF network element, carrying the measured clock deviation in the first clock deviation measurement indication. Optionally, the target UPF network element can also carry one or more of the following in the first clock deviation measurement indication: the identifier of the target UPF network element, the identifier of the target RAN device, the identifier of the target UPF network element's clock, and the identifier of the target RAN device's clock. This facilitates the TSCTSF network element in identifying the target UPF network element and / or the target RAN device corresponding to the clock deviation carried in the first clock deviation measurement, as well as the corresponding clock of the target UPF network element and / or the target RAN device.

[0113] Of course, the TSCTSF network element can also send a second clock deviation measurement indication to the target RAN device. The second clock deviation measurement indication includes the identifier of the target UPF network element, which is used to instruct the RAN device to initiate the measurement of the clock deviation between the target UPF network element and the target RAN device. The RAN device initiates the clock deviation measurement and replies to the TSCTSF network element with a second clock deviation response that includes the clock deviation between the target RAN device and the target UPF network element.

[0114] In one possible implementation, the TSCTSF network element can also periodically acquire the clock offset between different RAN devices and the UPF network element according to a set period. Upon receiving a gPTP clock synchronization request, it can directly use the latest acquired clock offset between the target RAN device and the target UPF. Optionally, if the difference between the time of receiving the gPTP clock synchronization request and the time of acquiring the clock offset is greater than a set threshold, the TSCTSF network element can reacquire the clock offset between the target RAN device and the target UPF.

[0115] TSCTSF network elements are configured to use S303A or S303B.

[0116] S303A: The TSCTSF network element sends a clock offset to the target UPF network element, and the clock offset is used by the target UPF network element to synchronize with the clock of the target UE.

[0117] In one possible implementation, the TSCTSF network element can send a clock offset to the target UPF network element. The target UPF network element can then use this clock offset to correct its own clock when subsequently stamping gPTP synchronization messages from or to the target UE.

[0118] Taking clock offset as an example, when the exit point of the gPTP synchronization message is at the target UE side, the target UPF network element (such as NW-TT in the target UPF network element) changes the entry timestamp from the uncorrected Tsi to Tsi-offset when it timestamps the gPTP synchronization message sent to the target UE. When the target UE (such as DS-TT in the target UE) receives the gPTP synchronization message, it timestamps the exit timestamp Tse. By subtracting Tsi-offset from Tse, the accurate dwell time of the gPTP synchronization message in the 5G bridge (i.e., in the 5G communication system) can be obtained.

[0119] When the exit point of the gPTP synchronization message is at the target UPF network element, the target UE adds an entry timestamp (Tsi) to the gPTP synchronization message sent to the target UPF network element. When the target UPF network element receives the gPTP synchronization message, it changes the exit timestamp from the uncorrected Tse to Tse-offset. By using Tse-offset-Tsi, the accurate dwell time of the gPTP synchronization message in the 5G bridge can be obtained.

[0120] S303B: The TSCTSF network element sends a clock offset to the target UE. The clock offset is used for clock correction when the target UE is synchronizing with the UPF network element.

[0121] In another possible implementation, the TSCTSF network element can send a clock offset to the target UE. The target UE network element can then use this clock offset to correct its own clock when subsequently stamping gPTP synchronization messages. Taking `offset` as an example, when the exit point of the gPTP synchronization message is at the target UE side, the entry timestamp of the gPTP synchronization message by the target UPF network element (such as NW-TT in the target UPF network element) is `Tsi`. After receiving the gPTP synchronization message, when the target UE (such as DS-TT in the target UE) stamps the exit timestamp of the gPTP synchronization message, the exit timestamp changes from the uncorrected `Tse` to `Tse + offset`. By subtracting `Tsi` from `Tse + offset`, the accurate dwell time of the gPTP synchronization message in the 5G bridge can be obtained.

[0122] When the exit point of the gPTP synchronization message is at the target UPF network element, when the target UE adds an entry timestamp to the gPTP synchronization message sent to the target UPF network element, the entry timestamp changes from the uncorrected Tsi to Tsi + offset. When the target UPF network element receives the gPTP synchronization message, it sets the exit timestamp to Tse. By subtracting (Tsi + offset) from Tse, the accurate dwell time of the gPTP synchronization message in the 5G bridge can be obtained.

[0123] The following is combined Figure 1A and Figure 1B The network architecture is achieved through the following Figure 5 The embodiments described above Figure 3 The specific implementation examples will be described in detail.

[0124] S501: The AF network element sends a gPTP clock synchronization request to the NEF network element. The gPTP clock synchronization request includes the identifier of the target UPF network element and the identifier of the target UE.

[0125] In one possible implementation, the gPTP clock synchronization request may also include a requirement for clock synchronization between the target UE and the target UPF, such as whether clock synchronization (i.e., the same clock) is required between the target UE and the target UPF.

[0126] Optionally, the AF element can be a TSN AF element.

[0127] Optionally, the gPTP synchronization request message is Nnef_TimeSynchronization_ASTICreate / Update / Deleterequest.

[0128] S502: The NEF network element sends a gPTP clock synchronization request to the TSCTSF network element.

[0129] After receiving a gPTP clock synchronization request from an AF network element, the NEF network element can authenticate the AF network element. Once authentication is successful, the NEF network element sends a gPTP clock synchronization request to the TSCTSF network element. The content of this gPTP clock synchronization request is the same as the content of the gPTP clock synchronization request in step 501 above.

[0130] Optionally, the gPTP clock synchronization request is Ntsctsf_TimeSynchronization_ASTICreate / Update / Deleterequest.

[0131] S503: The TSCTSF network element sends a gPTP clock synchronization response to the NEF network element.

[0132] S504: The NEF network element sends a gPTP clock synchronization response to the AF network element.

[0133] After receiving the gPTP clock synchronization request, the TSCTSF network element sends a gPTP clock synchronization response to the NEF network element. When the NEF network element receives the gPTP clock synchronization response, it forwards the gPTP clock synchronization response to the AF network element.

[0134] Optionally, the gPTP clock synchronization response can be Ntsctsf_TimeSynchronization_ASTICreate / Update / Delete response.

[0135] Optionally, if the gPTP clock synchronization request may also include requirements for clock synchronization within the 5G network, or clock synchronization between the target UE and the target UPF, and if the clocks of the target UE and the target UPF are not synchronized, the gPTP clock synchronization response will also carry a notification of clock synchronization request failure. Simultaneously, the TSCTSF network element may also change the corresponding port information. For example, if the target RAN device clock is switched, the TSCTSF network element will temporarily mark the DS-TT port on the target UE as disabled. If the target UPF network element clock is switched, the TSCTSF network element will temporarily mark the NW-TT port on the target UPF network element as disabled. Once the target device clock is synchronized / normalized after the clock switch, the corresponding ports will be marked as enabled.

[0136] S505: When the target UPF network element and the target RAN clock are out of sync, the TSCTSF network element sends a first clock deviation measurement indication to the target UPF network element.

[0137] The first clock deviation measurement indication includes the identifier of the target RAN device, which is used to instruct the target UPF network element to initiate the measurement of the clock deviation between the target UPF network element and the target RAN device, that is, to instruct the target UPF network element to initiate the RTT operation on the target RAN device.

[0138] Optionally, the TSCTSF network element can also send a first clock deviation measurement response indication to the target RAN device. The first clock deviation measurement response indication includes the identifier of the target UPF network element, which is used to indicate that the target RAN device responds to the clock deviation measurement initiated by the target UPF, that is, to indicate that the target RAN device responds to the RTT operation initiated by the target UPF network element.

[0139] Figure 5 In this example, when a target UE detects a difference in clock identifiers recorded in the timestamps of the transmitted gPTP synchronization message between the target UE and the target UPF network element, it sends a clock asynchronization notification to the TSCTSF network element, including the identifiers of both the target UE and the target UPF network element. Upon receiving this clock asynchronization notification, the TSCTSF network element determines that the target UE and the target UPF network element are clock-asynchronous. Optionally, the clock asynchronization notification may also carry the identifier of the target RAN device that provides timing for the target UE, facilitating the TSCTSF network element's identification of the target RAN device. This identifier can be added by the target UE to the clock asynchronization notification or by the AMF network element forwarding the notification.

[0140] S506: The TSCTSF network element receives a first clock deviation measurement indication response from the target UPF network element, the first clock deviation measurement indication including the clock deviation between the target UPF network element and the target RAN device.

[0141] After the TSCTSF network element obtains the clock deviation between the target UPF network element and the target RAN device, it can send the clock deviation to the target UE or the target UPF network element for clock synchronization between the target UE and the target UPF network element. In other words, when the target UE or the target UPF network element receives the clock deviation, it uses the clock deviation to correct its own clock when stamping the gPTP synchronization message.

[0142] Understandably, if the target UPF network element performs the RTT operation and determines the clock offset between the target UPF network element and the target RAN device, the TSCTSF network element may no longer send the clock offset to the target UE or the target UPF network element. By default, the target UPF network element that initiated the RTT operation will use the clock offset for clock correction.

[0143] In some scenarios, the target UPF network element may use multiple clocks, meaning that the target UPF network element uses information from multiple clock domains. When the target UPF network element uses multiple clocks, the TSCTSF network element can also determine (or specify) a target clock among the multiple clocks used by the target UPF network element, as the clock used by the target UPF network element when synchronizing with the target RAN device or target UE.

[0144] Furthermore, if the TSCTSF network element instructs the target UPF network element to initiate a measurement of the clock deviation between the target UPF network element and the target RAN device, the first clock deviation indication sent to the target UPF network element also includes the identifier of the target clock, indicating that the target clock is the clock used by the target UPF network element when synchronizing with the target RAN device or the target UE. If the TSCTSF network element instructs the target RAN device to initiate a measurement of the clock deviation between the target UPF network element and the target RAN device, the TSCTSF network element can also send a second clock deviation measurement response indication to the target UPF network element. The second clock deviation measurement response indication includes the identifier of the target clock and the identifier of the target RAN device, used to instruct the target UPF network element to respond to the clock deviation measurement initiated by the target RAN device using the target clock. Simultaneously, the second clock deviation indication sent to the target RAN device can also include the identifier of the target clock, instructing the target RAN device to perform deviation measurement with the target clock in the target UPF network element.

[0145] Information about multiple clocks used by the target UPF network element, such as the clock attributes of the multiple clocks, can be reported by the target UPF network element to the clock management network element through a setting request or other requests. This application does not impose any restrictions on this.

[0146] In some implementations, in order to facilitate the TSCTSF network element's knowledge of the clock used by the UPF network element corresponding to the clock deviation, the first clock deviation measurement indication response replied by the target UPF network element to the TSCTSF network element, or the second clock deviation measurement indication response replied by the target RAN device to the TSCTSF network element, also includes the identifier of the target clock.

[0147] It should be understood that when the target UPF network element has multiple clocks, the clock of the target UPF network element and the target UE are not synchronized. This can mean that the target UE is not synchronized with the target clock of the target UPF network element, or it can mean that the target UE is not synchronized with each clock of the target UPF network element. This application does not limit this.

[0148] The following example uses the measurement of clock deviation between the target UPF network element and the target RAN equipment as an example, combined with... Figure 1A and Figure 1B The network architecture is achieved through the following Figure 6The specific implementation examples will be described in detail.

[0149] S601: The AF network element sends a gPTP clock synchronization request to the NEF network element. The gPTP clock synchronization request includes the identifier of the target UPF network element and the identifier of the target UE.

[0150] S602: The NEF network element sends a gPTP clock synchronization request to the TSCTSF network element.

[0151] S603: The TSCTSF network element sends a gPTP clock synchronization response to the NEF network element.

[0152] S604: The NEF network element sends a gPTP clock synchronization response to the AF network element.

[0153] The implementation of S601-S604 is the same as that of S501-S504, and will not be described again.

[0154] S605: When the target UPF network element and the target RAN clock are out of sync, the TSCTSF network element sends a first clock deviation measurement indication to the target UPF network element.

[0155] The first clock deviation measurement indication includes the identifier of the target RAN device, which is used to instruct the target UPF network element to initiate the measurement of the clock deviation between the target UPF network element and the target RAN device. The first clock deviation measurement indication also includes the identifier of the target clock, which instructs the target UPF network element to use the target clock to synchronize with the target RAN device or the target UE. When performing clock deviation measurement with the target RAN device, the target UPF network element uses the target clock.

[0156] Optionally, the TSCTSF network element can also send a first clock deviation measurement response indication to the target RAN device. The first clock deviation measurement response indication includes the identifier of the target UPF network element, which is used to instruct the target RAN device to respond to the clock deviation measurement initiated by the target UPF, such as responding to the RTT operation initiated by the target UPF network element.

[0157] S606: The TSCTSF network element receives a first clock deviation measurement indication response from the target UPF network element. The first clock deviation measurement indication includes the clock deviation between the target UPF network element and the target RAN device, as well as the identifier of the target clock.

[0158] Based on the first clock offset measurement indication from the target UPF network element, the TSCTSF network element can determine the clock offset between the target UPF network element and the target RAN equipment when the target clock is applied. The TSCTSF can send this clock offset to the target UE or the target UPF network element for clock synchronization between the target UE and the target UPF network element. That is, when the target UE or the target UPF network element (applying the target clock) receives the clock offset, it uses the clock offset to correct its own clock when stamping the gPTP synchronization message.

[0159] Understandably, if the target UPF network element initiates the clock offset measurement to determine the clock offset between the target UPF network element and the target RAN device, the TSCTSF network element may no longer send the clock offset to the target UE or the target UPF network element. By default, the target UPF network element that initiated the clock offset measurement will use the clock offset for clock correction.

[0160] The above Figure 3 and Figure 6 The clock synchronization guarantee is mainly achieved by obtaining the clock deviation between the target RAN device and the target UPF network element for timing the target UE, and using the clock correction when the target UE and the target UPF network element perform clock synchronization. In some implementations, clock synchronization can also be guaranteed by enabling the target RAN device or the target UPF network element to receive timing from the other party.

[0161] Figure 7 This is a schematic diagram of another clock synchronization guarantee method provided in an embodiment of this application. The method includes:

[0162] S701: The TSCTSF network element receives a gPTP clock synchronization request from the AF network element. The gPTP clock synchronization request includes the identifier of the target UPF network element and the identifier of the target UE.

[0163] When the target UPF network element and the target RAN clock are out of sync, perform S702A and S702B, or S703A and S703B, where the target RAN device is the timing RAN device of the target UE.

[0164] S702A: The TSCTSF network element sends the first timing instruction to the target RAN equipment.

[0165] S702B: The TSCTSF network element sends the first multi-domain clock indication to the target UPF network element.

[0166] The first timing indication includes the identifier of the target UPF network element, which is used to instruct the target RAN device to provide timing to the target UPF network element. The first multi-domain clock indication includes the identifier of the target RAN device and the identifier of the target UE, which is used to instruct the target UPF network element to receive the timing from the target RAN device and to synchronize the clock with the target UE using the clock from the target RAN device.

[0167] S703A: The TSCTSF network element sends a second timing instruction to the target UPF network element.

[0168] S703B: Sends a second multi-domain clock indication to the target RAN device.

[0169] The second timing indication includes the identifier of the target RAN device, which is used to instruct the target UPF network element to provide timing for the target RAN device. The second multi-domain clock indication includes the identifier of the target UPF network element and the identifier of the target UE, which is used to instruct the target RAN device to receive the timing from the target UPF network element and to use the clock from the target UPF network element to provide timing for the target UE.

[0170] The target RAN device is the timing RAN device of the target UE.

[0171] The implementation of S701 can be referred to the implementation of S301, and will not be described in detail here.

[0172] In cases where the target UPF network element and the target UE clocks are out of sync, in one possible implementation, the TSCTSF network element can instruct the target UPF network element to receive timing information from the target RAN device. Multiple clocks are applied to the target UPF network element. When clock synchronization with the target UE is involved (such as timestamping gPTP synchronization messages sent to or from the target UE), the target UPF network element uses the clock from the target RAN device to ensure that it operates on the same clock as the target UE.

[0173] In another possible implementation, the TSCTSF network element can also instruct the target RAN device to receive timing from the target UPF network element, apply multiple clocks on the target RAN device, and use the clock from the target UPF network element to provide timing to the target UE, ensuring that the target UPF network element and the target UE work under the same clock.

[0174] Additionally, it is understandable that the TSCTSF network element can also instruct the target UPF network element to provide time synchronization to the target UE. The target UE receives the time synchronization from the target UPF and applies multiple clocks (such as the clock from the target RAN equipment and the clock from the target UE). The target UE uses the clock from the target UPF network element to synchronize with the target UPF network element. For example, when the target UE receives a gPTP synchronization message from the target UPF network element, it uses the clock from the target UPF to stamp it.

[0175] The following example illustrates how the TSCTSF network element instructs the target UPF network element to receive timing information from the target RAN device. Figure 1A and Figure 1B The network architecture is achieved through the following Figure 8 The embodiments described above Figure 7 The specific implementation examples will be described in detail.

[0176] S801: The AF network element sends a gPTP clock synchronization request to the NEF network element. The gPTP clock synchronization request includes the identifier of the target UPF network element and the identifier of the target UE.

[0177] S802: The NEF network element sends a gPTP clock synchronization request to the TSCTSF network element.

[0178] S803: The TSCTSF network element sends a gPTP clock synchronization response to the NEF network element.

[0179] S804: The NEF network element sends a gPTP clock synchronization response to the AF network element.

[0180] Perform S805A and S805B when the target UPF network element and the target RAN clock are out of sync.

[0181] The implementation of S801-S804 is the same as that of S501-S504, and will not be described again.

[0182] Figure 8 In this example, when the target UE detects that the clock identifiers recorded in the timestamps of the target UE and the target UPF network element in the transmitted gPTP synchronization message are different, it sends a clock asynchronization notification including the identifiers of the target UE and the target UPF network element to the TSCTSF network element. When the TSCTSF network element receives the clock asynchronization notification sent by the target UE, it determines that the clocks of the target UE and the target UPF network element are out of sync.

[0183] S805A: The TSCTSF network element sends the first timing instruction to the target RAN equipment.

[0184] S805B: The TSCTSF network element sends the first multi-domain clock indication to the target UPF.

[0185] The first timing indication includes the identifier of the target UPF network element, used to instruct the target RAN device to provide timing to the target UPF network element; the first multi-domain clock indication includes the identifier of the target RAN device and the identifier of the target UE, used to instruct the target UPF network element to receive the timing from the target RAN device and to synchronize its clock with the target UE using the clock from the target RAN device. Optionally, the first multi-domain clock indication may also include port status information of the DS-TT port on the target UE.

[0186] After the target RAN device synchronizes the time with the target UPF network element, the target UPF network element maintains a clock with the same clock parameters as the target RAN's clock. Subsequently, the target UPF network element uses this clock for stamping gPTP synchronization messages sent to or from the target UE. Additionally, if ratio measurements are involved for a UPF network element (such as NW-TT on the UPF network element), the UPF network element uses the corresponding target RAN's clock for ratio measurements, such as when measuring the ratio between the 5G communication system and the TSN system.

[0187] In some implementations, the available timing error budget of the air interface can be flexibly adjusted based on the gPTP clock synchronization error budget of the target UE and the target UPF network element, thereby enabling clock synchronization between the target UE and the target UPF network element.

[0188] Figure 9 Another clock synchronization guarantee method provided in this application embodiment includes:

[0189] S901: The TSCTSF network element receives a gPTP clock synchronization request from the AF network element.

[0190] The gPTP clock synchronization request includes clock synchronization parameters. The clock management network element can obtain the identifier of the target user plane function network element, the identifier of the target terminal device, and the gPTP clock synchronization error budget from the clock synchronization parameters when performing TSN clock synchronization.

[0191] The implementation of S901 can refer to the implementation of S301. The difference between S901 and S301 is that in S901, the TSCTSF network element can also obtain the gPTP clock synchronization error budget from the gPTP clock synchronization request from the AF network element.

[0192] The gPTP clock synchronization error budget can be the clock error allowed between the device-side TSN system corresponding to the target UE and the network-side TSN network corresponding to the target UPF element. This clock error can be pre-configured by the TSN network user according to usage requirements, etc.

[0193] S902: The TSCTSF network element determines the available timing error budget of the target RAN device for the target terminal device based on the clock error of the target UPF network element and the target RAN device, as well as the gPTP clock synchronization error budget. The target RAN device is the timing RAN device for the target terminal device.

[0194] Specifically, the TSCTSF network element can determine the available timing error budget of the target RAN device for the target terminal device, i.e., the available timing error budget of the air interface, based on the difference between the gPTP clock synchronization error budget and the absolute value of the clock deviation between the target UPF network element and the target RAN device.

[0195] In some implementations, after considering the determination of the target UPF network element and the target RAN device, the link for transmitting messages between the target UPF network element and the target RAN device is usually fixed. The TSCTSF network element can also obtain the error caused by this link and further subtract this error when determining the available timing error budget of the target RAN device to the target terminal device.

[0196] S903: When the available timing error budget is within the timing error budget supported by the target RAN device, the TSCTSF network element sends the available timing error budget to the target RAN device. The available timing error budget is used by the target RAN device for timing with the terminal device.

[0197] S904: When the available timing error budget is not within the timing error budget supported by the target RAN device, the TSCTSF network element sends a clock synchronization request failure notification to the AF network element. The clock synchronization request failure notification is used to notify that the requested gPTP clock synchronization has failed, i.e., TSN clock synchronization has failed. Optionally, the clock synchronization request failure notification may also carry a reason for failure, such as the target UPF network element and the target UE clocks being out of sync.

[0198] When the available timing error budget is within the timing error budget supported by the target RAN device, the TSCTSF network element can send the available timing error budget to the target RAN device. The target RAN device uses the available timing error budget to time the target UE. That is, the target RAN device guarantees that the timing error of the target UE is within the available timing error budget, which can ensure that the gPTP synchronization message is stamped by the target UE and the target UPF, and the resulting dwell time is within the required gPTP clock synchronization error budget, thus meeting the synchronization requirements of TSN.

[0199] Understandably, the time synchronization error (or timing error) budget range supported by the target RAN device can be determined based on the minimum time synchronization error that the target RAN device's hardware or software, such as its clock, can support. In other words, the time synchronization error budget range supported by the target RAN device is greater than or equal to this minimum time synchronization error. Furthermore, the target RAN device typically provides time synchronization errors to the target UE within a certain range. If the available time synchronization error budget is significantly greater than the target RAN device's operating time synchronization error range for the target UE, then it can be considered that the target RAN device's time synchronization for the target UE meets the requirements of the available time synchronization error budget, and the TSCTSF network element can stop sending the available time synchronization error budget to the target RAN device.

[0200] When the available timing error budget is not within the timing error budget supported by the target RAN device, the TSCTSF network element can send a clock synchronization request failure notification to the AF network element, informing the AF network element that the clock synchronization between the target UPF network element and the target UE has failed.

[0201] Optionally, if the available timing error budget is not within the timing error budget supported by the target RAN equipment, the TSCTSF network element can also use the above-mentioned... Figure 3 , Figure 5 , Figure 6 , Figure 7 , Figure 8 This method ensures clock synchronization between the target UE and the target UPF.

[0202] It's important to note that when using a 5G communication system for gPTP clock synchronization, another possibility is that the gPTP packets are imported into one UE and exported to another. In this case, the clock management network element needs to first determine whether the clocks of the two UEs are synchronized with the same access network device. If they are different access network devices, one of them can be used as the UPF network element in the above method. Specifically, the access network device corresponding to the UE importing the gPTP packets can be used as the UPF network element in the above method, and the above process can be performed. Figure 3 , Figure 5 , Figure 6 , Figure 7 ,or Figure 8 The clock synchronization guarantee method shown can also be applied by treating the access network device of the corresponding gPTP message exit UE as the UPF network element in the above method. Figure 3 , Figure 5 , Figure 6 , Figure 7 ,or Figure 8The clock synchronization guarantee method is shown. If the access network devices are the same, then when the access network device clock switches / abnormales / holdovers, the two UEs will still synchronize with the same access network device. At this time, the clock management network element can still reuse the existing technology to perform gPTP clock synchronization, or temporarily mark the DS-TT port number on the affected UEs as unavailable.

[0203] It is understood that, in order to implement the functions in the above embodiments, the clock management function network element includes the corresponding hardware structure and / or software module for executing each function. Those skilled in the art should readily recognize that, based on the units and method steps described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0204] Figure 10 and Figure 11 The diagram illustrates the possible communication devices provided in the embodiments of this application. These communication devices can be used to implement the functions of the clock management function network element in the above method embodiments, and thus also achieve the beneficial effects of the above method embodiments. In one possible implementation, the communication device can be a clock management function network element, or it can be a module (such as a chip) applied to the clock management function network element.

[0205] like Figure 10 As shown, the communication device 1000 includes a processing unit 1010 and an interface unit 1020, wherein the interface unit 1020 may also be a transceiver unit or an input / output interface. The communication device 1000 can be used to implement the above-mentioned... Figure 3 , Figures 5-9 The method embodiments shown illustrate the functions of network devices or terminal devices.

[0206] When the communication device 1000 is used to implement Figure 3 , Figure 5 , Figure 6 In the method embodiment shown, the clock management function network element functions as follows:

[0207] Interface unit 1020 is used to receive gPTP clock synchronization requests from application function network elements. The gPTP clock synchronization requests include the identifier of the target user plane function network element and the identifier of the target terminal device.

[0208] Processing unit 1010 is used to obtain the clock deviation between the target user plane functional network element and the target access network device through interface unit 1020 when the clocks of the target user plane functional network element and the target terminal device are out of sync. The target access network device is the timing access network device of the target terminal device.

[0209] The interface unit 1020 is also used to send a clock offset to the target user plane function network element, the clock offset being used by the target user plane function network element to synchronize with the clock of the target terminal device; or, it is used to send a clock offset to the target terminal device, the clock offset being used by the target terminal device to synchronize with the clock of the user plane function network element.

[0210] In one possible design, when the processing unit 1010 obtains the clock deviation between the target user plane function network element and the target access network device through the interface unit 1020, it is specifically used to send a first clock deviation measurement indication to the target user plane function network element through the interface unit 1020. The first clock deviation measurement indication includes the identifier of the target access network device, which is used to instruct the target user plane function network element to initiate the measurement of the clock deviation between the target user plane function network element and the target access network device; and to receive a first clock deviation measurement indication response from the target user plane function network element, which includes the clock deviation between the target user plane function network element and the target access network device.

[0211] In one possible design, when multiple clocks are used by the target user plane function network element, the first clock deviation measurement indication also includes the identifier of the target clock, and the first clock deviation measurement indication response also includes the identifier of the target clock; wherein, the target clock is the clock used by the target user plane function network element for clock synchronization with the target access network equipment or the target terminal equipment, as determined by the processing unit 1010 among multiple clocks.

[0212] In one possible design, when the processing unit 1010 obtains the clock deviation between the target user plane function network element and the target access network device through the interface unit 1020, it is specifically used to send a second clock deviation measurement indication to the target access network device through the interface unit 1020. The second clock deviation measurement indication includes the identifier of the target user plane function network element, which is used to instruct the target access network device to initiate the measurement of the clock deviation between the target user plane function network element and the target access network device; and to receive a second clock deviation measurement indication response from the target access network device, which includes the clock deviation between the target user plane function network element and the target access network device.

[0213] In one possible design, when multiple clocks are used by the target user plane function network element, the second clock deviation measurement indication also includes the identifier of the target clock, and the second clock deviation measurement indication response also includes the identifier of the target clock; wherein, the target clock is the clock used by the user plane function network element to synchronize with the target access network equipment or the target terminal equipment, which is determined by the processing unit 1010 from among multiple clocks.

[0214] In one possible design, the processing unit 1010 is further configured to send a second clock deviation measurement response indication to the target user plane function element via the interface unit 1020. The second clock deviation measurement response indication includes the identifier of the target clock and the identifier of the target access network device, and is used to instruct the target user plane function element to respond to the clock deviation measurement initiated by the target access network device using the target clock.

[0215] In one possible design, when the processing unit 1010 obtains the clock deviation between the target user plane function network element and the target access network device through the interface unit 1020, it is specifically used to obtain the clock attributes of the target user plane function network element clock and the clock attributes of the target access network device clock through the interface unit 1020; and to determine the clock deviation between the target user plane function network element and the target access network device based on the clock attributes of the target user plane function network element clock and the clock attributes of the target access network device clock.

[0216] In one possible design, the processing unit 1010 determines that the clocks of the target user plane function network element and the target terminal device are out of sync when at least one of the following conditions is met: the interface unit 1020 receives a clock switching notification from the target user plane function network element; the interface unit 1020 receives a clock switching notification from the target access network device; the interface unit 1020 receives a clock switching notification from the network management network element indicating that the clocks of the target user plane function network element or the target access network device have switched; the interface unit 1020 receives a clock asynchronization notification from the target terminal device, the clock asynchronization notification indicating that the clocks of the target terminal device and the target user plane function network element are out of sync; the interface unit 1020 receives a clock asynchronization notification from the target user plane function network element, the clock asynchronization notification indicating that the clocks of the target user plane function network element and the target terminal device are out of sync.

[0217] When the communication device 1000 is used to implement Figure 9 In the method embodiment shown, the clock management function network element functions as follows:

[0218] Interface unit 1020 is used to receive a General Precision Time Protocol (gPTP) clock synchronization request from an application function network element. The gPTP clock synchronization request includes the identifier of the target user plane function network element, the identifier of the target terminal device, and the gPTP clock synchronization error budget.

[0219] Processing unit 1010 is used to determine the available timing error budget of the target access network device for the target terminal device based on the clock deviation between the target user plane functional network element and the target access network device, as well as the gPTP clock synchronization error budget. The target access network device is the timing access network device for the target terminal device.

[0220] The interface unit 1020 is also used to send the available timing error budget to the target access network device when the available timing error budget is within the range of the timing error budget supported by the target access network device. The available timing error budget is used by the target access network device to synchronize the timing of the terminal device.

[0221] In one possible design, the interface unit 1020 is also used to send a clock synchronization request failure notification to the application function network element when the available timing error budget is not within the range of the timing error budget supported by the target access network device. The clock synchronization request failure notification is used to notify that the requested gPTP clock synchronization has failed.

[0222] When the communication device 1000 is used to implement Figure 7 , Figure 8 In the method embodiment shown, the clock management function network element functions as follows:

[0223] Processing unit 1010 is used to determine that the clocks of the target user plane functional network element and the target terminal equipment are out of sync;

[0224] Interface unit 1020 is configured to send a first timing indication to a target access network device and a first multi-domain clock indication to a target user plane function network element. The first timing indication includes an identifier of the target user plane function network element and is used to instruct the target access network device to provide timing to the target user plane function network element. The first multi-domain clock indication includes an identifier of the target access network device and an identifier of the target terminal device and is used to instruct the target user plane function network element to receive timing from the target access network device and synchronize its clock with the target terminal device using the clock from the target access network device. Alternatively, it is configured to send a second timing indication to the target user plane function network element and a second multi-domain clock indication to the target access network device. The second timing indication includes an identifier of the target access network device and is used to instruct the target user plane function network element to provide timing to the target access network device. The second multi-domain clock indication includes an identifier of the target user plane function network element and an identifier of the target terminal device and is used to instruct the target access network device to receive timing from the target user plane function network element and synchronize its clock with the target terminal device using the clock from the target user plane function network element. The target access network device is the timing access network device for the target terminal device.

[0225] In one possible design, the processing unit 1010 determines that the clocks of the target user plane function network element and the target terminal device are out of sync when at least one of the following conditions is met: the interface unit 1020 receives a clock switching notification from the target user plane function network element; the interface unit 1020 receives a clock switching notification from the target access network device; the interface unit 1020 receives a clock switching notification from the network management network element indicating that the clocks of the target user plane function network element or the target access network device have switched; the interface unit 1020 receives a clock asynchronization notification from the target terminal device, the clock asynchronization notification indicating that the clocks of the target terminal device and the target user plane function network element are out of sync; the interface unit 1020 receives a clock asynchronization notification from the target user plane function network element, the clock asynchronization notification indicating that the clocks of the target user plane function network element and the target terminal device are out of sync.

[0226] like Figure 11 As shown, this application also provides a communication device 1100, including a processor 1110 and an interface circuit 1120. The processor 1110 and the interface circuit 1120 are coupled to each other. It is understood that the interface circuit 1120 can be a transceiver, an input / output interface, an input interface, an output interface, a communication interface, etc. Optionally, the communication device 1100 may also include a memory 1130 for storing instructions executed by the processor 1110, or storing input data required by the processor 1110 to run instructions, or storing data generated after the processor 1110 runs instructions. Optionally, the memory 1130 may also be integrated with the processor 1110.

[0227] When the communication device 1100 is used to implement Figure 3 , Figures 5-9 In the method shown, processor 1110 can be used to implement the functions of the processing unit 1010, and interface circuit 1120 can be used to implement the functions of the interface unit 1020.

[0228] It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), logic circuits, field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0229] The method steps in the embodiments of this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Additionally, the ASIC can reside in a network device or terminal device. Alternatively, the processor and storage medium can exist as discrete components in the network device or terminal device.

[0230] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one network device, terminal, computer, server, or data center to another network device, terminal, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0231] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0232] Additionally, it should be understood that in the embodiments of this application, the term "exemplary" is used to indicate that it is an example, illustration, or description. Any embodiment or design scheme described as "exemplary" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the term "exemplary" is intended to present the concept in a concrete manner.

[0233] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A clock synchronization guarantee method, characterized in that, include: The clock management network element receives a General Precision Time Protocol (gPTP) clock synchronization request from the application function network element. The gPTP clock synchronization request includes the identifier of the target user plane function network element and the identifier of the target terminal device. When the clocks of the target user plane function network element and the target terminal device are out of sync, the clock management network element obtains the clock deviation between the target user plane function network element and the target access network device, where the target access network device is the timing access network device of the target terminal device; The clock management network element sends the clock deviation to the target user plane function network element, and the clock deviation is used by the target user plane function network element to synchronize with the clock of the target terminal device. or, The clock management network element sends the clock deviation to the target terminal device, and the clock deviation is used by the target terminal device to synchronize with the clock of the user plane function network element.

2. The method as described in claim 1, characterized in that, The clock management network element acquires the clock offset between the target user plane function network element and the target access network device, including: The clock management network element sends a first clock deviation measurement instruction to the target user plane function network element. The first clock deviation measurement instruction includes the identifier of the target access network device and is used to instruct the target user plane function network element to initiate a measurement of the clock deviation between the target user plane function network element and the target access network device. The clock management network element receives a first clock deviation measurement indication response from the target user plane function network element, the first clock deviation measurement indication including the clock deviation between the target user plane function network element and the target access network device.

3. The method as described in claim 2, characterized in that, When multiple clocks are applied to the target user plane function network element, the first clock deviation measurement indication further includes the identifier of the target clock, and the first clock deviation measurement indication response further includes the identifier of the target clock; Wherein, the target clock is the clock determined by the clock management network element from among the plurality of clocks, used by the target user plane function network element for clock synchronization with the target access network device or the target terminal device.

4. The method as described in claim 1, characterized in that, The clock management network element acquires the clock offset between the target user plane function network element and the target access network device, including: The clock management network element sends a second clock deviation measurement indication to the target access network device. The second clock deviation measurement indication includes the identifier of the target user plane function network element, which is used to instruct the target access network device to initiate a measurement of the clock deviation between the target user plane function network element and the target access network device. The clock management network element receives a second clock deviation measurement indication response from the target access network device, the second clock deviation measurement indication response including the clock deviation between the target user plane function network element and the target access network device.

5. The method as described in claim 4, characterized in that, When multiple clocks are applied to the target user plane function network element, the second clock deviation measurement indication also includes the identifier of the target clock, and the second clock deviation measurement indication response also includes the identifier of the target clock; The target clock is the clock determined by the clock management network element from among the multiple clocks, used by the user plane function network element for clock synchronization with the target access network device or the target terminal device.

6. The method as described in claim 5, characterized in that, The method further includes: The clock management network element sends a second clock deviation measurement response indication to the target user plane function network element. The second clock deviation measurement response indication includes the identifier of the target clock and the identifier of the target access network device, and is used to instruct the target user plane function network element to respond to the clock deviation measurement initiated by the target access network device using the target clock.

7. The method according to any one of claims 1-6, characterized in that, The clock management network element acquires the clock offset between the target user plane function network element and the target access network device, including: The clock management network element obtains the clock attributes of the target user plane function network element clock and the clock attributes of the target access network device clock. The clock management network element determines the clock deviation between the target user plane function network element and the target access network device based on the clock attributes of the target user plane function network element's clock and the target access network device's clock.

8. The method according to any one of claims 1-6, characterized in that, The clock management network element determines that the clocks used by the target user plane function network element and the target terminal device are out of sync when at least one of the following conditions is met: The clock management network element receives a clock switching notification from the target user plane function network element; The clock management network element receives a clock switching notification from the target access network device; The clock management network element receives a clock switching notification from the network management network element, which indicates that the clock of the target user plane function network element or the target access network device has been switched. The clock management network element receives a clock asynchrony notification from the target terminal device. The clock asynchrony notification is used to indicate that the clocks of the target terminal device and the target user plane function network element are out of sync. The clock management network element receives a clock asynchronization notification from the target user plane function network element. The clock asynchronization notification is used to indicate that the clocks of the target user plane function network element and the target terminal device are out of sync.

9. A clock synchronization guarantee method, characterized in that, include: The clock management network element receives a General Precision Time Protocol (gPTP) clock synchronization request from the application function network element. The gPTP clock synchronization request includes the identifier of the target user plane function network element, the identifier of the target terminal device, and the gPTP clock synchronization error budget. The clock management network element determines the available timing error budget of the target access network device for the target terminal device based on the clock deviation between the target user plane function network element and the target access network device, as well as the gPTP clock synchronization error budget. The target access network device is the timing access network device of the target terminal device. When the available timing error budget is within the time error budget supported by the target access network device, the clock management network element sends the available timing error budget to the target access network device. The available timing error budget is used by the target access network device to provide time synchronization for the terminal device.

10. The method as described in claim 9, characterized in that, The method further includes: When the available timing error budget is not within the timing error budget supported by the target access network device, the clock management network element sends a clock synchronization request failure notification to the application function network element. The clock synchronization request failure notification is used to notify that the requested gPTP clock synchronization has failed.

11. A clock synchronization guarantee method, characterized in that, include: The clock management network element determines that the clocks of the target user plane functional network element and the target terminal equipment are out of sync; The clock management network element sends a first timing indication to the target access network device and a first multi-domain clock indication to the target user plane function network element. The first timing indication includes the identifier of the target user plane function network element and is used to instruct the target access network device to provide timing to the target user plane function network element. The first multi-domain clock indication includes the identifier of the target access network device and the identifier of the target terminal device and is used to instruct the target user plane function network element to receive the timing from the target access network device and to synchronize its clock with the target terminal device using the clock from the target access network device. or, The clock management network element sends a second timing indication to the target user plane function network element and a second multi-domain clock indication to the target access network device. The second timing indication includes the identifier of the target access network device and is used to instruct the target user plane function network element to provide timing for the target access network device. The second multi-domain clock indication includes the identifier of the target user plane function network element and the identifier of the target terminal device and is used to instruct the target access network device to receive the timing from the target user plane function network element and to use the clock from the target user plane function network element to provide timing for the target terminal device. The target access network device is the timing access network device of the target terminal device.

12. The method as described in claim 11, characterized in that, The clock management network element determines that the clocks of the target user plane function network element and the target terminal device are out of sync when at least one of the following conditions is met: The clock management network element receives a clock switching notification from the target user plane function network element; The clock management network element receives a clock switching notification from the target access network device; The clock management network element receives a clock switching notification from the network management network element, which indicates that the clock of the target user plane function network element or the target access network device has been switched. The clock management network element receives a clock asynchrony notification from the target terminal device. The clock asynchrony notification is used to indicate that the clocks of the target terminal device and the target user plane function network element are out of sync. The clock management network element receives a clock asynchronization notification from the target user plane function network element. The clock asynchronization notification is used to indicate that the clocks of the target user plane function network element and the target terminal device are out of sync.

13. A communication device, characterized in that, Includes interface units and processing units; The interface unit is used to receive a General Precision Time Protocol (gPTP) clock synchronization request from an application function network element. The gPTP clock synchronization request includes the identifier of the target user plane function network element and the identifier of the target terminal device. The processing unit is configured to obtain the clock deviation between the target user plane function network element and the target access network device through the interface unit when the clocks of the target user plane function network element and the target terminal device are out of sync. The target access network device is the timing access network device of the target terminal device. The interface unit is further configured to send the clock offset to the target user plane function network element, and the clock offset is used by the target user plane function network element to synchronize with the clock of the target terminal device; Alternatively, it can be used to send the clock offset to the target terminal device, the clock offset being used by the target terminal device to synchronize with the clock of the user plane function network element.

14. The apparatus as claimed in claim 13, characterized in that, When the processing unit obtains the clock deviation between the target user plane function network element and the target access network device through the interface unit, it is specifically used to send a first clock deviation measurement indication to the target user plane function network element through the interface unit. The first clock deviation measurement indication includes the identifier of the target access network device and is used to instruct the target user plane function network element to initiate the measurement of the clock deviation between the target user plane function network element and the target access network device. It also receives a first clock deviation measurement indication response from the target user plane function network element, the first clock deviation measurement indication including the clock deviation between the target user plane function network element and the target access network device.

15. The apparatus as claimed in claim 14, characterized in that, When the target user plane function network element applies multiple clocks, the first clock deviation measurement indication further includes an identifier of the target clock, and the first clock deviation measurement indication response further includes the identifier of the target clock; wherein, the target clock is the clock determined by the processing unit from the multiple clocks for the target user plane function network element to perform clock synchronization with the target access network device or the target terminal device.

16. The apparatus as claimed in claim 13, characterized in that, When the processing unit obtains the clock deviation between the target user plane function network element and the target access network device through the interface unit, it is specifically used to send a second clock deviation measurement indication to the target access network device through the interface unit. The second clock deviation measurement indication includes the identifier of the target user plane function network element and is used to instruct the target access network device to initiate a measurement of the clock deviation between the target user plane function network element and the target access network device. It also receives a second clock deviation measurement indication response from the target access network device, the second clock deviation measurement indication response including the clock deviation between the target user plane function network element and the target access network device.

17. The apparatus as claimed in claim 16, characterized in that, When the target user plane function network element applies multiple clocks, the second clock deviation measurement indication further includes the identifier of the target clock, and the second clock deviation measurement indication response further includes the identifier of the target clock; wherein, the target clock is the clock determined by the processing unit from the multiple clocks for the user plane function network element to perform clock synchronization with the target access network device or the target terminal device.

18. The apparatus as claimed in claim 17, characterized in that, The processing unit is further configured to send a second clock deviation measurement response indication to the target user plane function network element through the interface unit. The second clock deviation measurement response indication includes the identifier of the target clock and the identifier of the target access network device, and is used to instruct the target user plane function network element to respond to the clock deviation measurement initiated by the target access network device using the target clock.

19. The apparatus as claimed in any one of claims 13-18, characterized in that, When the processing unit obtains the clock deviation between the target user plane function network element and the target access network device through the interface unit, it is specifically used to obtain the clock attributes of the clock of the target user plane function network element and the clock attributes of the clock of the target access network device through the interface unit. Based on the clock attributes of the target user plane functional network element clock and the clock attributes of the target access network device clock, the clock deviation between the target user plane functional network element and the target access network device is determined.

20. The apparatus according to any one of claims 13-18, characterized in that, The processing unit determines that the clocks of the target user plane function network element and the target terminal device are out of sync when at least one of the following conditions is met: The interface unit receives a clock switching notification from the target user plane function network element; The interface unit receives a clock switching notification from the target access network device; The interface unit receives a clock switching notification from the network management network element, which indicates that the clock of the target user plane function network element or the target access network device has been switched. The interface unit receives a clock asynchrony notification from the target terminal device. The clock asynchrony notification is used to indicate that the clocks of the target terminal device and the target user plane function network element are out of sync. The interface unit receives a clock asynchronization notification from the target user plane function network element, which indicates that the clocks of the target user plane function network element and the target terminal device are out of sync.

21. A communication device, characterized in that, Includes interface units and processing units; The interface unit is used to receive a General Precision Time Protocol (gPTP) clock synchronization request from an application function network element. The gPTP clock synchronization request includes the identifier of the target user plane function network element, the identifier of the target terminal device, and the gPTP clock synchronization error budget. The processing unit is configured to determine the available timing error budget of the target access network device for the target terminal device based on the clock deviation between the target user plane function network element and the target access network device, and the gPTP clock synchronization error budget, wherein the target access network device is the timing access network device of the target terminal device; The interface unit is further configured to send the available timing error budget to the target access network device when the available timing error budget is within the range supported by the target access network device, wherein the available timing error budget is used by the target access network device to provide timing for the terminal device.

22. The apparatus as claimed in claim 21, characterized in that, The interface unit is further configured to send a clock synchronization request failure notification to the application function network element when the available timing error budget is not within the timing error budget supported by the target access network device. The clock synchronization request failure notification is used to notify that the requested gPTP clock synchronization has failed.

23. A communication device, characterized in that, Includes interface units and processing units; The processing unit is used to determine that the clocks of the target user plane functional network element and the target terminal device are out of sync; The interface unit is configured to send a first timing indication to the target access network device and a first multi-domain clock indication to the target user plane function element, wherein the first timing indication includes the identifier of the target user plane function element and is used to instruct the target access network device to provide timing to the target user plane function element; the first multi-domain clock indication includes the identifier of the target access network device and the identifier of the target terminal device and is used to instruct the target user plane function element to receive the timing from the target access network device and synchronize its clock with the target terminal device using the clock from the target access network device; or, it is configured to send a second timing indication to the target user plane function element and a second multi-domain clock indication to the target access network device, wherein the second timing indication includes the identifier of the target access network device and is used to instruct the target user plane function element to provide timing to the target access network device; the second multi-domain clock indication includes the identifier of the target user plane function element and the identifier of the target terminal device and is used to instruct the target access network device to receive the timing from the target user plane function element and synchronize its clock with the target terminal device using the clock from the target user plane function element. The target access network device is the timing access network device of the target terminal device.

24. The apparatus as claimed in claim 23, characterized in that, The processing unit determines that the clocks of the target user plane function network element and the target terminal device are out of sync when at least one of the following conditions is met: The interface unit receives a clock switching notification from the target user plane function network element; The interface unit receives a clock switching notification from the target access network device; The interface unit receives a clock switching notification from the network management network element, which indicates that the clock of the target user plane function network element or the target access network device has been switched. The interface unit receives a clock asynchrony notification from the target terminal device. The clock asynchrony notification is used to indicate that the clocks of the target terminal device and the target user plane function network element are out of sync. The interface unit receives a clock asynchronization notification from the target user plane function network element, which indicates that the clocks of the target user plane function network element and the target terminal device are out of sync.

25. A communication device, characterized in that, The device includes a processor and an interface circuit. The interface circuit is used to receive signals from other communication devices besides the communication device and transmit them to the processor, or to send signals from the processor to other communication devices besides the communication device. The processor is used to implement the method as described in any one of claims 1-12 through logic circuits or execution instructions.

26. A computer program product, characterized in that, It includes instructions that, when executed, cause the method as described in any one of claims 1-12 to be implemented.

27. A chip, characterized in that, The chip is used to implement the method as described in any one of claims 1-12.

28. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions that, when executed, cause the method as described in any one of claims 1-12 to be implemented.

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