WO2023231465A1

WO2023231465A1 - Time synchronization method, communication apparatus and communication system

Info

Publication number: WO2023231465A1
Application number: PCT/CN2023/077913
Authority: WO
Inventors: 臧昕; 周润泽; 王远
Original assignee: 华为技术有限公司
Priority date: 2022-05-31
Filing date: 2023-02-23
Publication date: 2023-12-07
Also published as: CN117202336A

Abstract

Embodiments of the present application provide a time synchronization method, a communication apparatus, and a communication system. The method comprises: a terminal device receiving timing information from an access network device; when the terminal device does not receive new timing information from the access network device within a set duration, the terminal device performing time synchronization according to the current time of the terminal device, the receiving time of the timing information, and the timing information. According to the solution, when the access network device cannot send new timing information to the terminal device, or the access network device cannot send new timing information to the terminal device in time, the terminal device can realize accurate time synchronization between the terminal device and the access network device according to the timing information received from the access network device, and the communication capability of the terminal device can be improved.

Description

A time synchronization method, communication device and communication system

Cross-references to related applications

This application claims priority to a Chinese patent application filed with the China Patent Office on May 31, 2022, with application number 202210613427.3 and the application title "A time synchronization method, communication device and communication system", the entire content of which is incorporated by reference. in this application.

Technical field

The present application relates to the field of communication technology, and in particular, to a time synchronization method, communication device and communication system.

Background technique

In order to ensure correct communication between the terminal device and other devices, time synchronization of the terminal device is generally required. The current synchronization method is that the terminal device receives the system information block (SIB) message broadcasted by the access network device. The SIB message carries the time synchronization information of the access network device, and the terminal device obtains the synchronization information from the SIB message. time information, and perform time synchronization with the access network equipment based on the time information.

In the above scheme, the terminal equipment relies more on the timing of the access network equipment. When the clock source on the access network equipment fails, or the timing frequency of the access network equipment is low, the terminal equipment will be unable or unable to receive the time information in time. , which in turn causes the terminal device to be unable to maintain accurate time synchronization with the access network device, reducing the communication capability of the terminal device.

Contents of the invention

Embodiments of the present application provide a time synchronization method, communication device and communication system to achieve time synchronization between terminal equipment and access network equipment.

In the first aspect, embodiments of the present application provide a time synchronization method, which can be executed by a terminal device or a module (such as a chip) in the terminal device. Taking the terminal device executing this method as an example, the method includes: the terminal device receives the time synchronization information from the access network device; the terminal device according to the current time of the terminal device, the reception time of the time synchronization information and the time synchronization information, Perform time synchronization.

With the above solution, the terminal device can achieve precise time synchronization between the terminal device and the access network device based on the time synchronization information previously received from the access network device. The terminal device does not rely on the access network device to provide timely synchronization information. Therefore, when the access network device cannot send new time synchronization information to the terminal device, or the access network device cannot send new time synchronization information to the terminal device in time, the terminal device can also complete the time synchronization, which helps to improve the terminal device. communication capabilities.

In a possible implementation method, the terminal device performs time synchronization based on the current time of the terminal device, the reception time of the time synchronization information, and the time synchronization information, including: when the preset conditions are met, the terminal device performs time synchronization according to the time synchronization information of the terminal device. The current time, the reception time of the time synchronization information and the time synchronization information are time synchronized; wherein, the preset condition is: the terminal device does not receive a new time synchronization from the access network device within the set time period. information; or, the terminal device receives the first indication information and the new time synchronization information from the access network device within a set period of time, and the first indication information indicates that the new time synchronization information does not meet the requirements of the terminal device. time accuracy requirements.

In the above solution, when the terminal device does not receive new time information from the access network device within the set time period; or, The terminal device receives indication information and new time synchronization information from the access network device within a set time period. If the indication information indicates that the new time synchronization information does not meet the time synchronization accuracy requirements of the terminal device, the terminal device can Based on the time synchronization information previously received from the access network equipment, precise time synchronization between the terminal equipment and the access network equipment is achieved, which helps to improve the communication capabilities of the terminal equipment.

In a possible implementation method, after the terminal device receives the time synchronization information from the access network device, the terminal device stores the reception time of the time synchronization information and the time synchronization information.

In the above scheme, the terminal device stores the time synchronization information from the access network device, so that when the terminal device cannot receive new time synchronization information from the access network device within a certain time period, the terminal device can obtain the stored time synchronization information and The reception time of the time synchronization information, and time synchronization based on the time synchronization information and the reception time of the time synchronization information, helps to achieve precise time synchronization between the terminal equipment and the access network equipment, thereby helping to improve the terminal The communication capabilities of the device.

In a possible implementation method, the terminal device performs time synchronization based on the current time of the terminal device, the reception time of the time synchronization information, and the time synchronization information, including: the terminal device determines that the current time of the terminal device is consistent with the time synchronization information. The difference between the reception times of the time synchronization information; the terminal device determines the synchronization time based on the difference and the time synchronization information; the terminal device performs time synchronization based on the synchronization time.

In a possible implementation method, the time synchronization information includes a clock frequency ratio and a clock deviation. The clock frequency ratio represents a clock frequency ratio between the terminal device and the access network device. The clock deviation represents a clock frequency ratio between the terminal device and the access network device. Clock deviation between access network devices; the terminal device determines the synchronization time based on the difference and the time synchronization information, including: the terminal device determines the ratio of the difference to the clock frequency ratio; the terminal device determines the synchronization time based on the ratio , the clock deviation and the reception time of the time synchronization information, determine the synchronization time.

In the above solution, the terminal device performs time synchronization based on the clock frequency ratio and clock deviation, which helps to achieve accurate time synchronization.

In a possible implementation method, the time synchronization information includes a clock frequency ratio, a transmission delay and a sending time of the time synchronization information. The clock frequency ratio represents a clock frequency ratio between the terminal device and the access network device, The transmission delay represents the transmission delay between the terminal device and the access network device; the terminal device determines the synchronization time based on the difference and the time synchronization information, including: the terminal device determines the difference and the clock The ratio of the frequency ratio; the terminal device determines the synchronization time based on the ratio, the transmission delay and the sending time of the time synchronization information.

In the above solution, the terminal equipment performs time synchronization based on the clock frequency ratio and transmission delay, which helps to achieve accurate time synchronization.

In a possible implementation method, the time synchronization information includes a clock deviation change rate, a clock frequency ratio, and a clock deviation. The clock deviation change rate represents the change of the clock deviation over time, and the clock frequency ratio represents the clock frequency ratio between the terminal device and the interface. The clock frequency ratio between network access devices, the clock deviation represents the clock deviation between the terminal device and the access network device; the terminal device determines the synchronization time based on the difference and the time synchronization information, including: the terminal The device determines the product of the clock deviation change rate and the difference, and determines the ratio of the product to the clock frequency ratio; the terminal device determines the synchronization time based on the ratio, the clock deviation, and the current time of the terminal device.

In the above solution, the terminal device performs time synchronization based on the clock frequency ratio, clock deviation and clock deviation change rate, which helps to achieve accurate time synchronization.

In a possible implementation method, the terminal device receives the set duration from the access network device.

In a possible implementation method, the set time period is preset.

In a possible implementation method, the terminal device sends a time synchronization request message, the time synchronization request message includes identification information of the terminal device and second indication information, and the second indication information indicates that the time synchronization service is provided for the terminal device.

In a possible implementation method, the terminal device receives information indicating turning on the time synchronization function.

In the above scheme, the terminal device turns on the time synchronization function according to the information used to indicate turning on the time synchronization function. Therefore, when the terminal device does not receive new time synchronization information from the access network device within a set period of time, the terminal device will turn on the time synchronization function according to the terminal device. The current time, the reception time of the time synchronization information and the time synchronization information are synchronized. This solution helps terminal devices synchronize time in the correct way.

In a possible implementation method, the time synchronization information includes a transmission delay and a sending time of the time synchronization information. The transmission delay represents the transmission delay between the terminal device and the access network device; the terminal device is based on Before performing time synchronization on the current time of the terminal device, the reception time of the time synchronization information, and the time synchronization information, the terminal device performs time synchronization based on the transmission delay and the sending time of the time synchronization information.

In the second aspect, embodiments of the present application provide a time synchronization method, which can be executed by an access network device or a module (such as a chip) in the access network device. Taking the access network device executing this method as an example, the method includes: the access network device determines time synchronization information, the time synchronization information includes a clock frequency ratio, and the clock frequency ratio represents the clock frequency ratio between the terminal device and the access network device. Clock frequency ratio; the access network device sends the time synchronization information to the terminal device, and the time synchronization information is used for local time synchronization of the terminal device.

In the above solution, the access network device sends time synchronization information to the terminal device, so that later the access network device cannot send new time synchronization information to the terminal device, or the access network device cannot send new time synchronization information to the terminal device in a timely manner. , then the terminal device can achieve precise time synchronization between the terminal device and the access network device based on the time synchronization information previously received from the access network device, which helps to improve the communication capabilities of the terminal device.

In a possible implementation method, the time synchronization information also includes a clock deviation, where the clock deviation represents a clock deviation between the terminal device and the access network device.

In a possible implementation method, the time synchronization information also includes a transmission delay and a sending time of the time synchronization information. The transmission delay represents a transmission delay between the terminal device and the access network device.

In a possible implementation method, the time synchronization information also includes a clock deviation change rate and a clock deviation. The clock deviation change rate represents the change of the clock deviation over time. The clock deviation represents the difference between the terminal device and the access network device. clock skew between.

In a possible implementation method, the access network device determines the first clock deviation at the first time and determines the second clock deviation at the second time; the access network device determines the second clock deviation according to the second clock deviation and the third clock deviation. A first difference in clock bias and a second difference between the second time and the first time determine the clock bias change rate.

In a possible implementation method, before the access network device determines the time synchronization information, the access network device receives indication information indicating that the time synchronization service is provided for the terminal device.

In the third aspect, embodiments of the present application provide a time synchronization method, which can be executed by a clock management network element or a module (such as a chip) in the clock management network element. Taking the clock management network element to execute this method as an example, the method includes: the clock management network element receives a time synchronization request message. The time synchronization request message includes identification information and indication information of the terminal device. The indication information indicates that the time synchronization request message is provided for the terminal device. time service; the clock management network element selects the access network device that provides time service for the terminal device; the clock management network element sends a notification message to the policy control network element, the notification message includes the identification information of the terminal device, the access network device The identification information of the network access device and the instruction information.

In the above solution, after receiving the time synchronization request message, the clock management network element selects the access network device that provides time synchronization services for the terminal device, and instructs the access network device to provide time synchronization services for the terminal device, which can realize the communication between the terminal device and the access network device. Precise time synchronization between networked devices helps improve the communication capabilities of terminal devices.

In a possible implementation method, the clock management network element sends a query message to the unified database network element, and the query message The information includes the identification information of the terminal device, and the query message requests to obtain the policy control network element that provides services for the terminal device; the clock management network element receives the identification information of the policy control network element from the unified database network element.

In a possible implementation method, the clock management network element sends a request message to the unified data management network element. The request message includes the identification information of the terminal device. The request message is used to request to query whether the terminal device is authorized to provide time synchronization. service; the clock management network element receives a response message from the unified data management network element, and the response message indicates that the terminal device is authorized to provide time synchronization services.

In the above solution, if the clock management network element determines that the terminal device is authorized to obtain time synchronization services, it instructs the access network device to provide time synchronization services for the terminal device, which helps avoid providing time synchronization services to unauthorized terminal devices.

In a possible implementation method, the clock management network element receives the time adjustment request message from the terminal device or application function network element.

In a fourth aspect, embodiments of the present application provide a communication device, which may be a terminal device or a module (such as a chip) in the terminal device. The device has the function of implementing any implementation method of the above-mentioned first aspect. This function can be implemented by hardware, or it can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

In a fifth aspect, embodiments of the present application provide a communication device, which may be an access network device or a module (such as a chip) in the access network device. The device has the function of implementing any implementation method of the above second aspect. This function can be implemented by hardware, or it can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

In a sixth aspect, embodiments of the present application provide a communication device, which may be a clock management network element or a module (such as a chip) in the clock management network element. The device has the function of implementing any implementation method of the above third aspect. This function can be implemented by hardware, or it can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

In a seventh aspect, embodiments of the present application provide a communication device, including a processor and a memory; the memory is used to store computer instructions, and when the device is running, the processor executes the computer instructions stored in the memory to cause the device to execute Any implementation method in the above first to third aspects.

In an eighth aspect, embodiments of the present application provide a communication device, including units or means (means) for executing each step of any implementation method in the above-mentioned first to third aspects.

In a ninth aspect, embodiments of the present application provide a communication device, including a processor coupled to a memory. The processor is configured to call a program stored in the memory to execute any implementation method in the above first to third aspects. . The memory may be located within the device or external to the device. And the processor can be one or more.

In a tenth aspect, embodiments of the present application provide a communication device, including a processor and an interface circuit. The processor is configured to communicate with other devices through the interface circuit and execute any implementation method in the above-mentioned first to third aspects. The processor includes one or more.

In an eleventh aspect, embodiments of the present application further provide a computer program product. The computer program product includes a computer program or instructions. When the computer program or instructions are run by a communication device, any one of the above-mentioned first to third aspects is enabled. The implementation method is executed.

In a twelfth aspect, embodiments of the present application further provide a computer-readable storage medium, in which instructions are stored, and when run on a communication device, the instructions in the first to third aspects are implemented. Any implementation method of is executed.

In a thirteenth aspect, embodiments of the present application further provide a chip system, including: a processor, configured to execute the above first Any implementation method from aspect to third aspect.

In a fourteenth aspect, embodiments of the present application further provide a communication system, including a terminal device for performing any of the methods of the first aspect, and an access network device for performing any of the methods of the second aspect.

Description of the drawings

Figure 1(a) is a schematic diagram of the 5G network architecture based on service-based architecture;

Figure 1(b) is a schematic diagram of the 5G network architecture based on point-to-point interface;

Figure 2 is a flow chart of a time synchronization method provided by an embodiment of the present application;

Figure 3(a) is an example diagram of time synchronization provided by the embodiment of the present application;

Figure 3(b) is another example diagram of time synchronization provided by the embodiment of the present application;

Figure 3(c) is another example diagram of time synchronization provided by the embodiment of the present application;

Figure 4 is a flow chart of a time synchronization method provided by an embodiment of the present application;

Figure 5 is a flow chart of a time synchronization method provided by an embodiment of the present application;

Figure 6 is a flow chart of a time synchronization method provided by an embodiment of the present application;

Figure 7 is a schematic diagram of a communication device provided by an embodiment of the present application;

Figure 8 is a schematic diagram of a communication device provided by an embodiment of the present application.

Detailed ways

Figure 1(a) is a schematic diagram of the 5G network architecture based on service-based architecture. The 5G network architecture shown in Figure 1(a) includes a data network (DN) and an operator network. The following is a brief introduction to the functions of some of the network elements.

The operator's network includes one or more of the following network elements: Authentication Server Function (AUSF) network element (not shown in the figure), unified data management (UDM) network element, unified database (Unified Data Repository, UDR) network element, Network Repository Function (NRF) network element (not shown in the figure), Network Exposure Function (NEF) network element (not shown in the figure), 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, 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 functions (Time Sensitive Communication and Time Synchronization Function, TSCTSF) network elements, etc. In the above operator network, network elements or equipment other than access network equipment can be called core network elements or core network equipment.

Access network equipment includes wired access network equipment and wireless access network equipment. The wireless access network equipment may be a base station (base station), an evolved base station (evolved NodeB, eNodeB), a transmission reception point (TRP), or a next generation base station (next generation NodeB, in the 5G mobile communication system). gNB), the next generation base station in the 6th generation (6G) mobile communication system, the base station in the future mobile communication system or the access node in the wireless fidelity (wireless fidelity, WiFi) system, etc.; it can also be completed The modules or units of some functions of the base station, for example, can be a centralized unit (CU) or a distributed unit (DU). The wireless access network equipment can be a macro base station, a micro base station or an indoor station, or a relay node or a donor node, etc. The embodiments of this application do not limit the specific technology and specific equipment form used by the access network equipment.

Terminal equipment that communicates with RAN includes terminals, user equipment (UE), mobile stations, mobile terminals, etc. In the figure, the terminal device is a UE as an example. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), and the Internet of Things (Internet of things, IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver functions, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc. The embodiments of this application do not limit the specific technology and specific equipment form used by the terminal equipment.

Access network equipment and terminal equipment can be fixed-position or removable. Access network equipment and terminal equipment can be deployed on land, indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed on aircraft, balloons and satellites in the sky. The embodiments of this application do not limit the application scenarios of access network equipment and terminal equipment.

The mobility management network element is a control plane network element provided by the operator's network. It is responsible for access control and mobility management of terminal devices accessing the operator's network. For example, it includes mobility status management, assigning user temporary identities, authenticating and authorizing users. and other functions. In 5G, the mobility management network element can be an AMF network element. In future communications such as the 6th generation (6G), the mobility management network element can still be an AMF network element, or have other names. There are no restrictions on application.

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

The user plane network element is a gateway provided by the operator, and is the gateway for communication between the operator's network and the DN. UPF network elements include user plane-related functions such as data packet routing and transmission, packet detection, business usage reporting, Quality of Service (QoS) processing, legal interception, uplink packet detection, and downlink data packet storage. In 5G, the user plane network element can be a UPF network element. In future communications such as 6G, the user plane network element can still be a UPF network element, or have other names. This application does not limit it.

The data management network element is a control plane network element provided by the operator. It is responsible for storing the subscriber permanent identifier (SUPI), credential, security context, and subscription of subscribed users in the operator's network. Data and other information. This information stored in the data management network element can be used for authentication and authorization of terminal devices accessing the operator's network. Among them, the contract users of the above-mentioned operator network can specifically be users who use services provided by the operator network, such as users who use China Telecom's mobile phone chip cards, or users who use China Mobile's mobile phone chip cards, etc. The permanent subscription identifier (Subscription Permanent Identifier, SUPI) of the above-mentioned subscriber can be the number of the mobile phone chip card, etc. The trust certificate and security context of the above-mentioned contract user can be a small file stored in the encryption key of the mobile phone chip card or information related to the encryption of the mobile phone chip card, for authentication and/or authorization. The above security context may be data (cookie) or token stored on the user's local terminal (such as a mobile phone). The contract data of the above-mentioned contract users can be the supporting services of the mobile phone chip card, such as the traffic package or network usage of the mobile phone chip card. It should be noted that permanent identifiers, credentials, security context, authentication data (cookies), and tokens are equivalent to authentication and authorization. The relevant information is not distinguished or restricted in this application document for the convenience of description. Unless otherwise specified, the embodiments of this application will be described using security context as an example, but the embodiments of this application are also applicable to authentication and/or authorization information expressed in other ways. In 5G, the data management network element can be a UDM network element. In future communications such as 6G, the data management network element can still be a UDM network element, or have other names. This application does not limit it.

The unified database network element is a control plane network element provided by the operator, and includes access functions for executing contract data, policy data, application data and other types of 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 have other names. This application does not limit it.

Network open network elements are control plane network elements provided by operators. The network opening network element opens the external interface of the operator's network to third parties in a secure manner. When the session management network element needs to communicate with a third-party network element, the network open network element can serve as a relay for the communication between the session management network element and the third-party network element. When the network open network element serves as a relay, it can be used to translate the identification information of the subscriber and the identification information of the third-party network element. For example, when the network opening network element sends the SUPI of the subscriber from the operator network to a third party, it can translate the SUPI into its corresponding external identity. On the contrary, when the network opening network element sends the external ID (the third-party network element ID) to the operator network, it can be translated into SUPI. In 5G, network open network elements can be NEF network elements. In future communications such as 6G, network open network elements can still be NEF network elements, or have other names. This application does not limit it.

The application function network element is used to transmit the requirements of the application side to the network side, such as QoS requirements or user status event subscriptions. The application function network element can be a third-party functional entity or an application server deployed by the operator. In 5G, the application function network element can be an AF network element. In future communications such as 6G, the application function network element can still be an AF network element, or have other names. This application does not limit it.

The policy control network element is a control plane function provided by the operator and is used to provide PDU session policies to the session management network element. Policies may include accounting-related policies, QoS-related policies, authorization-related policies, etc. In 5G, the policy control network element can be a PCF network element. In future communications such as 6G, the policy control network element can still be a PCF network element, or have other names. This application does not limit it.

Network storage function network elements can be used to provide network element discovery functions and provide network element information corresponding to network element types based on requests from other network elements. The network storage function network element also provides network element management services, such as network element registration, update, de-registration, network element status subscription and push, etc. In 5G, the network storage function network element can be an NRF network element. In future communications such as 6G, the network storage function network element can still be an NRF network element, or have other names. This application does not limit it.

The clock management network element can be used to manage the clock information of one or more clock sources in the 5G network. It can provide the clock information of the clock source externally through its own port, such as directly or indirectly to terminal equipment, access network equipment, core network equipment or Third-party application function network elements provide clock information. Among them, the clock information represents the time, moment or time point of the clock; the clock management network element can also select the corresponding timing network element according to the timing request of the timing requester. The timing network element can be, for example, a UPF network element or an access network device. etc., or it can be the clock management network element itself, and then the clock management network element instructs the timing network element to provide timing services to the timing requester. In 5G, the clock management network element can be a TSCTSF network element defined by 3GPP. In future communications such as 6G, the clock management network element can still be a TSCTSF network element, or have other names. This application does not limit it.

DN is a network located outside the operator's network. The operator's network can access multiple DNs. A variety of services can be deployed on the DN, which can provide data and/or voice services to terminal devices. For example, DN is a private network of a smart factory. The sensors installed in the workshop of the smart factory can be terminal devices. The control server of the sensor is deployed in the DN, and the control server can provide services for the sensor. The sensor can communicate with the control server, obtain instructions from the control server, and transmit the collected sensor data to the control server according to the instructions. For another example, DN is the internal office network of a company. The mobile phones or computers of company employees can be used as terminal devices, and the employees' mobile phones or computers can access information and data resources on the company's internal office network.

In Figure 1(a), Npcf, Nudr, Nudm, Naf, Namf, Nsmf, and Ntsctsf are respectively provided by the above-mentioned PCF network element, UDR network element, UDM network element, AF network element, AMF network element, SMF network element, and TSCTSF network element. The service interface is used to call the corresponding service operation. N1, N2, N3, N4 and N6 are interface serial numbers. The meanings of these interface serial numbers are as follows:

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.

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, etc.

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

4), N4: The interface between the SMF network element and the UPF network element can be used to transfer information between the control plane and the user plane, including controlling the delivery of user-oriented forwarding rules, QoS rules, traffic statistics rules, etc. Report information on the user interface.

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

Figure 1(b) is a schematic diagram of the 5G network architecture based on point-to-point interfaces. For the introduction of the functions of the network elements, please refer to the introduction of the functions of the corresponding network elements in Figure 1(a) and will not be described again. The main difference between Figure 1(b) and Figure 1(a) is that the interfaces between the control plane network elements in Figure 1(a) are service-oriented interfaces. The interface between them is a point-to-point interface.

In the architecture shown in Figure 1(b), the interface names and functions between each network element are as follows:

1), the meaning of N1, N2, N3, N4 and N6 interfaces can refer to the previous description.

2), N5: The interface between the AF network element and the PCF network element, which can be used to deliver application service requests and report network events.

3), N7: The interface between PCF network element and SMF network element can be used to deliver protocol data unit (PDU) session granularity and service data flow granularity control policy.

4), N8: The interface between AMF network elements and UDM network elements, which can be used by AMF network elements to obtain access and mobility management-related subscription data and authentication data from UDM network elements, and for AMF network elements to register with UDM network elements. Information related to terminal device mobility management, etc.

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

6), N10: The interface between the SMF network element and the UDM network element, which can be used for the SMF network element to obtain session management-related contract data from the UDM network element, and for the SMF network element to register terminal device session-related information with the UDM network element.

7), N11: The interface between SMF network element and AMF network element can be used to transmit PDU session tunnel information between wireless access network equipment and UPF network element, control messages sent to terminal equipment, and control messages sent to Wireless resource control information of wireless access network equipment, etc.

8), N15: The interface between the PCF network element and the AMF network element, which can be used to deliver terminal device policies and access control-related policies.

9), N35: The interface between UDM network element and UDR network element, which can be used by UDM network element to obtain from UDR network element User contract data information.

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

It can be understood that the above network elements or functions can be network elements in hardware devices, software functions running on dedicated hardware, or virtualization functions instantiated on a platform (for example, a cloud platform). Optionally, the above network element or function can be implemented by one device, or can be implemented by multiple devices together, or can be a functional module in one device, which is not specifically limited in the embodiments of this application.

In the embodiments of this application, the base station and the UE are used as specific examples of access network equipment and terminal equipment respectively for description.

Figure 2 is a flow chart of a time synchronization method provided by an embodiment of the present application. The method includes the following steps:

Step 201: The base station determines time synchronization information.

Optionally, before step 201, the base station receives indication information indicating providing time synchronization services for the UE. The indication information triggers the base station to determine the time synchronization information.

Step 202: The base station sends time synchronization information to the UE. The time synchronization information is used for the UE to perform local time synchronization.

After receiving the time synchronization information, the UE stores the reception time of the time synchronization information and the time synchronization information.

Step 203: The UE performs time synchronization based on the current time of the UE, the reception time of the time synchronization information, and the time synchronization information.

In a possible implementation method, when the preset conditions are met, the UE performs time synchronization based on the current time of the UE, the reception time of the time information and the time information; where the preset condition is: the UE is not setting Receive new time synchronization information from the base station within a set time period; or, the UE receives indication information and new time synchronization information from the base station within a set time period, and the indication information indicates that the new time synchronization information does not satisfy the UE's synchronization requirements. time accuracy requirements.

The set duration may be sent to the UE by the base station, or may be preset on the UE.

With the above solution, the UE can achieve precise time synchronization between the UE and the base station based on the time synchronization information previously received from the base station. The UE does not rely on the base station to provide timely synchronization information. Therefore, the base station cannot send new time synchronization information to the UE. , or the base station cannot send new time synchronization information to the UE in time, the UE can also complete the time synchronization, which helps to improve the communication capability of the UE.

In one implementation method, before the above step 201, the UE also sends a time synchronization request message to the base station or core network element (such as AMF network element, TSCTSF network element, etc.). The time synchronization request message includes the identification information and instructions of the UE. Information, the indication information indicates providing time synchronization services for the UE.

In one implementation method, before the above step 203, the UE performs time synchronization based on the time synchronization information from the base station. For example, when the time synchronization information includes the transmission delay and the sending time of the time synchronization information, and the transmission delay represents the transmission delay between the UE and the base station, then the UE performs the processing according to the transmission delay and the sending time of the time synchronization information. Time synchronization. For another example, when the time synchronization information includes a clock deviation, and the clock deviation represents the clock deviation between the UE and the base station, the UE performs time synchronization based on the clock deviation and the reception time of the time synchronization information. In this way, precise time synchronization can be achieved.

In one implementation method, before the above step 203, the UE also receives information from the base station or core network element (such as AMF network element, TSCTSF network element, etc.) indicating to turn on the time synchronization function, and the UE turns on the time synchronization function based on this information. function, so that when the UE does not receive new time synchronization information from the base station within the set time period, the UE will perform time synchronization based on the current time of the UE, the reception time of the time synchronization information, and the time synchronization information. This solution helps the UE perform time synchronization in the correct method.

In one implementation method, in the above step 203, the UE performs time synchronization based on the current time of the UE, the reception time of the time synchronization information, and the time synchronization information. Specifically, the UE may determine the current time of the UE and the reception time of the time synchronization information. Of The difference between them is determined, and then the synchronization time is determined based on the difference and the time synchronization information, and time synchronization is performed based on the synchronization time.

The following describes three different methods for the UE to determine the synchronization time based on the difference between the UE's current time and the reception time of the time synchronization information, as well as the time synchronization information.

Method 1: The time synchronization information received by the UE includes a clock frequency ratio and a clock deviation. The UE determines the ratio of the difference to the clock frequency ratio, and determines the synchronization time based on the ratio, clock deviation, and the reception time of the time synchronization information.

The clock frequency ratio represents the ratio between the clock frequency of the UE and the clock frequency of the base station. For example, it can be calculated based on the time when the base station sends a message to the UE and the time when the UE receives the message, and the time when the UE sends the message to the base station and the time when the base station receives the message.

The clock offset represents the difference between the UE's clock and the base station's clock.

For example, synchronization time=(tx-ty)/ratio+ty+offset.

Among them, tx represents the current time of the terminal device, ty represents the reception time of the time synchronization information, ratio represents the clock frequency ratio, offset represents the clock deviation between the base station and the UE at time ty, and tx-ty represents the current time and time synchronization information of the UE. The difference between the reception times.

In the above formula, the UE receives the offset at time ty, and the UE updates the UE's time to ty+offset to complete time synchronization with the base station at time ty. Then, after the duration of (tx-ty) has elapsed, the UE takes the sum of the elapsed time and the UE's time at ty as the UE's synchronization time at tx. That is, the sum of (tx-ty)/ratio and (ty+offset) is regarded as the synchronization time of the UE. Among them, the reason why it needs to be divided by the ratio is that the time elapsed in the UE domain needs to be converted into the time elapsed in the base station domain. This method can accurately synchronize the time of the UE with the time of the base station when the UE does not receive the time synchronization information of the base station, or when the new time synchronization information received is not accurate enough.

Method 2: The time synchronization information received by the UE includes the clock frequency ratio, transmission delay and the sending time of the time synchronization information. The UE determines the ratio of the difference to the clock frequency ratio, and the UE determines the ratio, transmission delay and time synchronization information based on the ratio. The sending time determines the synchronization time.

The clock frequency ratio represents the clock frequency ratio between the UE and the base station, and the transmission delay represents the transmission delay between the UE and the base station.

For example, synchronization time=(tx-ty)/ratio+tz+delay.

Among them, tx represents the current time of the terminal device, ty represents the receiving time of the time information, tz represents the sending time of the time information, ratio represents the clock frequency ratio, delay represents the transmission delay, and tx-ty represents the time between the current time of the UE and the corresponding time. The difference between the time the message was received.

In the above formula, the UE receives tz and delay at time ty, and the UE updates the time of the UE to tz+delay to complete time synchronization with the base station at time ty. Then, after the duration of (tx-ty) has elapsed, the UE takes the sum of the elapsed time and the UE's time at ty as the UE's synchronization time at tx. That is, the sum of (tx-ty)/ratio and (tz+delay) is regarded as the synchronization time of the UE. Among them, the reason why it needs to be divided by the ratio is that the time elapsed in the UE domain needs to be converted into the time elapsed in the base station domain. This method can accurately synchronize the time of the UE with the time of the base station when the UE does not receive the time synchronization information of the base station, or when the new time synchronization information received is not accurate enough.

Method 3: The time synchronization information received by the UE includes the clock deviation change rate, clock frequency ratio and clock deviation. The UE determines the product of the clock deviation change rate and the difference, and determines the ratio of the product to the clock frequency ratio, and then based on the ratio, clock The offset and the UE's current time determine the synchronization time.

Among them, the clock deviation change rate represents the change of the clock deviation over time, the clock frequency ratio represents the clock frequency ratio between the UE and the base station, and the clock deviation represents the clock deviation between the UE and the base station.

For example, synchronization time=tx+drift*(tx-ty)/ratio+offset.

Among them, tx represents the current time of the terminal device, ty represents the reception time of the time information, drift represents the clock deviation change rate, that is, the rate of change of the clock deviation between the base station and the UE over time, ratio represents the clock frequency ratio, and offset represents The clock deviation between the base station and the UE at time ty, tx-ty represents the difference between the current time of the UE and the time when the time information is received.

The drift can be determined in the following manner: the base station determines the first clock deviation at the first time, and determines the second clock deviation at the second time, and then based on the first difference between the second clock deviation and the first clock deviation, And the second difference between the second time and the first time determines the drift. Specifically, drift=(second clock deviation-first clock deviation)/(second time-first time).

According to the above formula, the UE receives the offset at time ty, that is, the offset represents the deviation between the base station and the UE at time ty. Then after (tx-ty) time has passed, the deviation between the base station and the UE has changed, and the deviation change amount is drift*(tx-ty)/ratio, so drift*(tx-ty)/ratio+ offset represents the clock offset between the base station and the UE at tx time. Therefore, the UE uses the sum of tx and (drift*(tx-ty)/ratio+offset) as the synchronization time of the UE at time tx, and time synchronization can be achieved. Among them, the reason why it needs to be divided by the ratio is that the time elapsed in the UE domain needs to be converted into the time elapsed in the base station domain. This method can accurately synchronize the time of the UE with the time of the base station when the UE does not receive the time synchronization information of the base station, or when the new time synchronization information received is not accurate enough.

The above three methods will be described below with reference to specific examples shown in Figure 3(a), Figure 3(b) and Figure 3(c).

Figure 3(a) is an example diagram of time synchronization provided by the embodiment of the present application. The method is as follows:

Time t1: The base station sends message 1 to the UE at time t1;

Time t2: UE receives message 1 at time t2;

Time t3: UE sends message 2 to the base station at time t3. The header of message 2 carries the reception time t2 of message 1 and the sending time t3 of message 2;

Time t4: The base station receives message 2 at time t4;

Time t5: UE sends message 3 to the base station at time t5, and the header of message 3 carries the sending time t5 of message 3;

Time t6: The base station receives message 3 at time t6.

After the base station obtains the above time t1 to t6, it can execute the following method A or method B. Among them, the method A is an example of the above-mentioned method one, and the method B is an example of the above-mentioned method two.

Method A: The base station calculates the ratio and offset and sends the ratio and offset to the UE.

ratio=(t5-t3)/(t6-t4). ratio represents the clock frequency ratio between the UE and the base station.

offset=((t2-t1)-(t4-t3))/2. offset represents the clock offset between the UE and the base station.

Assume that the base station sends time synchronization information to the UE at time t7, and the UE receives the time synchronization information at time t8. The time synchronization information includes ratio and offset. Then the UE synchronizes the time based on the offset. The time after the UE synchronizes the time is t_new1=t8 +offset. Moreover, the UE also saves the received time synchronization information. Subsequently, if the UE does not receive new time synchronization information from the base station within the set time period, the UE starts local time synchronization. For example, if the current time of the UE is t9, the time after the UE performs local time synchronization is t_new2=(t9-t8)/ratio+t8+offset. Among them, the ratio and offset here come from the latest timing information received and saved by the UE.

Method B, the base station calculates the ratio and delay, and sends the ratio and delay to the UE.

delay=(ratio*(t4-t1)-(t3-t2))/2. delay represents the transmission delay between the UE and the base station.

Assume that the base station sends time synchronization information to the UE at time t7, and the UE receives the time synchronization information at time t8. The time synchronization information includes t7, ratio, and delay. Then the UE performs time synchronization based on t7 and delay. The time after the UE performs time synchronization It is t_new1=t7+delay. Moreover, the UE also saves the received time synchronization information. Subsequently, if the UE does not receive new time synchronization information from the base station within the set time period, the UE starts local time synchronization. For example, if the current time of the UE is t9, the time after the UE performs local time synchronization is t_new2=(t9-t8)/ratio+t7+delay. Among them, t7, ratio and delay here come from the latest time synchronization information received and saved by the UE.

Figure 3(b) is another example diagram of time synchronization provided by the embodiment of the present application. The main difference between Figure 3(b) and Figure 3(a) above is that in Figure 3(a), a message can carry the sending time of the message, for example, message 2 carries t3, and message 3 carries t5. ; In Figure 3(b), a message does not carry the sending time of the message. For example, message 2 does not carry t3, and message 3 does not carry t5. Based on the above differences, in Figure 3(a), the UE sends two messages to the base station to send time information to the base station. The time information includes t2, t3 and t5. In Figure 3(b), the UE sends 3 messages are used to send time information to the base station. The time information includes t2, t3 and t5. Other aspects of the embodiment based on FIG. 3(b) are the same as the above-mentioned embodiment of FIG. 3(a).

Figure 3(c) is another example diagram of time synchronization provided by the embodiment of the present application. The method is as follows:

Time t1: The base station sends message 1 to the UE at time t1;

Time t2: UE receives message 1 at time t2;

Time t4: The base station receives message 2 at time t4;

Time t5: The base station sends message 3 to the UE at time t5;

Time t6: UE receives message 3 at time t6;

Time t7: UE sends message 4 to the base station at time t7. The header of message 4 carries the reception time t6 of message 3 and the sending time t7 of message 4;

Time t8: The base station receives message 4 at time t8.

After the base station obtains the above time t1 to t8, it can perform the following method C. This method C is an example of method three above.

Method C: The base station calculates the drift, ratio and offset, and sends the drift, ratio and offset to the UE.

First, the base station calculates drift and ratio. Among them, drift=(offset2-offset1)/(t8-t4), offset1=((t2-t1)-(t4-t3))/2, offset2=((t6-t5)-(t8-t7))/ 2. Offset1 and offset2 both represent the clock deviation between the UE and the base station, and drift represents the change in offset over time. ratio=(t7-t3)/(t8-t4), ratio represents the clock frequency ratio between the UE and the base station.

Then, the base station sends time synchronization information to the UE at time t9, and the UE receives the time synchronization information at time t10. The time synchronization information includes ratio, drift, and offset2. The time after the UE performs time synchronization is t_new1=t10+offset2. Moreover, the UE also saves the received time synchronization information. Subsequently, if the UE does not receive new time synchronization information from the base station within the set time period, the UE starts local time synchronization. For example, if the current time of the UE is t11, the time after the UE performs local time synchronization is t_new2=t11+drift/ratio*(t11-t10)+offset2. Among them, the drift, ratio and offset2 here come from the latest time synchronization information received and saved by the UE.

In the embodiment of the present application, the above-mentioned method A and method B may be called an enhanced round trip time (Round Trip Time, RTT) time synchronization method, and the above-mentioned method C is called a two-way RTT time synchronization method.

The above-mentioned embodiment of FIG. 2 will be described in detail below with reference to the specific embodiments of FIGS. 4 to 6 .

Figure 4 is a schematic flowchart of a time synchronization method provided by an embodiment of the present application. This method is the AF request to provide timing services to the UE.

The method includes the following steps:

Step 401: The AF sends a time synchronization request message to the NEF. The time synchronization request message includes the identification information of the UE, the required time synchronization error accuracy and indication information.

The UE indicated by the identification information of the UE is the object that needs to be synchronized.

Among them, the required time error accuracy can be nanoseconds (ns), microseconds (us), etc.

In an implementation method, the indication information indicates that time synchronization services are provided for the UE.

In yet another implementation method, the indication information indicates that the time synchronization service is provided for the UE according to the enhanced RTT time synchronization method.

In another implementation method, the indication information indicates that the time synchronization service is provided for the UE according to the two-way RTT time synchronization method.

Optionally, the time synchronization request message is the Nnef_TimeSynchronization_ASTICreate/Update/Delete message.

Step 402: NEF sends a time synchronization request message to the TSCTSF. The time synchronization request message includes the identification information of the UE, the required time synchronization error accuracy and indication information.

After NEF receives the time request message from AF, it authenticates AF. When the authentication is passed, NEF sends a time request message to TSCTSF. The UE's identification information, required time error accuracy and indication information in the time synchronization request message sent by the NEF come from the AF.

Optionally, the time synchronization request message is an Ntsctsf_TimeSynchronization_ASTICreate/Update/Delete message.

Step 403: The TSCTSF selects a base station that provides time synchronization services for the UE.

For example, TSCTSF selects a base station that provides time synchronization services for the UE from multiple base stations based on the distribution information of the base stations and the required time synchronization error accuracy.

Step 404: The TSCTSF sends a query message to the UDR. The query message includes the identification information of the UE, and the query message requests to obtain the PCF that provides services for the UE.

In one implementation method, the query message is a Nudr_DM_Create/Update/Delete request message.

Step 405: The UDR sends a response message to the TSCTSF. The response message includes the identification information of the PCF.

In one implementation method, the response message is a Nudr_DM_Create/Update/Delete response message.

Step 406: The TSCTSF sends a notification message to the PCF. The notification message includes the identification information of the UE, the identification information of the base station, the indication information and the required time error accuracy.

This base station is the base station selected by the TSCTSF to provide time synchronization services for the UE. The identification information, indication information and required time synchronization error accuracy of the UE were received by the TSCTSF in the above step 402.

Step 407: The PCF sends policy information to the AMF. The policy information includes the identification information of the UE, the identification information of the base station, the indication information and the required time error accuracy.

The UE identification information, base station identification information, indication information and required time error accuracy in the policy information are received by the PCF from the TSCTSF.

Step 408: The AMF sends a notification message to the base station. The notification message includes the UE's identification information, indication information and required time error accuracy.

The base station is the base station indicated by the identification information of the base station in the policy information.

The UE's identification information, indication information and required time error accuracy in the notification message are received by the AMF from the PCF.

Step 409: The base station determines the time synchronization information according to the required time synchronization error accuracy.

That is to say, the time synchronization information determined by the base station meets the required time synchronization error accuracy.

In one implementation method, when the indication information received by the base station indicates that the UE is provided with time synchronization services, the base station first selects the enhanced RTT time synchronization method or the bidirectional RTT time synchronization method according to the required time synchronization error accuracy. Specifically, if the enhanced RTT time synchronization method is selected, the base station determines the time synchronization information based on the enhanced RTT time synchronization method and the required time synchronization error accuracy. The content of the time synchronization information can refer to the aforementioned method A or method B. If the two-way RTT time synchronization method is selected, the base station determines the time synchronization information based on the two-way RTT time synchronization method and the required time synchronization error accuracy. The content of the time synchronization information can refer to the aforementioned method C.

In another implementation method, when the instruction information received by the base station indicates that the UE is provided with time synchronization services according to the enhanced RTT method, the base station determines the time synchronization information according to the enhanced RTT time synchronization method and the required time synchronization error accuracy. For the content of the time information, please refer to the aforementioned method A or method B.

In another implementation method, when the instruction information received by the base station indicates that the UE is provided with time synchronization services according to the two-way RTT method, the base station determines the time synchronization information based on the two-way RTT time synchronization method and the required time synchronization error accuracy. The content of the time information can refer to the aforementioned method C.

Step 410: The base station sends time synchronization information to the UE.

Optionally, the base station also sends information indicating the time synchronization function to the UE, so that the UE enables the time synchronization function based on the information, which helps to accurately achieve time synchronization.

Step 411: The UE performs time synchronization based on the time synchronization information.

For the specific implementation of step 411, reference can be made to the description of the embodiment in FIG. 2 and will not be described again.

Optionally, after the above step 406, the TSCTSF may send a time synchronization response message to NEF to notify the successful time synchronization, and then the NEF sends a time synchronization response message to the AF to notify the successful time synchronization.

In the above scheme, the AF requests time synchronization services for the UE, and the TSCTSF selects a base station that provides time synchronization services for the UE, and the base station sends time synchronization information to the UE. Therefore, when the base station cannot send time synchronization information to the UE, or the base station cannot send time synchronization information to the UE in a timely manner, If the UE sends time synchronization information, the UE can achieve precise time synchronization between the UE and the base station based on the time synchronization information previously received from the base station, which helps to improve the communication capability of the UE.

Figure 5 is a schematic flowchart of a time synchronization method provided by an embodiment of the present application. This method is that when the clock source on the base station fails, the UE performs time synchronization based on locally saved time information.

The method includes the following steps:

Step 501: The base station sends a notification message to the TSCTSF. The notification message includes the identification information of the base station and indication information 1. The indication information 1 indicates that the clock source of the base station fails.

Optionally, the notification message also includes identification information of a UE that is affected by a clock source failure of the base station. That is, due to a clock source failure of the base station, it is impossible to continue to provide time synchronization services to the UE.

Step 502: The TSCTSF determines the UEs affected by the clock source failure of the base station.

When the notification message in step 501 above carries the identification information of the UE affected by the clock source failure of the base station, there is no need to perform step 502.

When the notification message in step 501 above carries the identification information of the UE affected by the clock source failure of the base station, step 502 is executed. In one implementation method, TSCTSF sends a request message to AMF/PCF. The request message includes the identification information of the base station. The request message requests to obtain the identification information of the UE affected by the clock source failure of the base station. Then AMF/PCF sends the request message to TSCTSF. Identification information of the UE affected by the clock source failure of the base station.

Step 503: TSCTSF sends a query message to the UDR. The query message includes the identification information of the UE, and the query message requests to obtain the PCF that provides services for the UE.

The UE indicated by the identification information of the UE is the UE affected by the clock source failure of the base station.

Step 504: The UDR sends a response message to the TSCTSF. The response message includes the identification information of the PCF.

Step 505: The TSCTSF sends a notification message to the PCF. The notification message includes the UE's identification information and indication information 2.

This indication information 2 instructs the UE to perform local time synchronization.

Step 506: The PCF sends policy information to the AMF, where the policy information includes the UE's identification information and indication information 2.

Step 507: AMF sends indication information 2 to the UE.

Optionally, the AMF also sends information indicating the time synchronization function to the UE, so that the UE enables the time synchronization function based on the information, which helps to accurately achieve time synchronization.

Step 508: The UE performs time synchronization based on locally saved time information.

For the specific implementation of step 508, reference can be made to the description of the embodiment in FIG. 2 and will not be described again.

In the above scheme, when the clock source of the base station fails, TSCTSF can notify the UE to perform local time synchronization, that is, the UE achieves precise time synchronization between the UE and the base station based on the time synchronization information previously received from the base station, which helps to improve the UE's communication capabilities.

Figure 6 is a schematic flowchart of a time synchronization method provided by an embodiment of the present application. This method is that the UE actively requests to provide time synchronization services for the UE.

The method includes the following steps:

Step 601: The UE sends a time synchronization request message to the AMF. The time synchronization request message includes the identification information of the UE, the required time synchronization error accuracy and indication information.

Optionally, the time synchronization request message is an Nnas_TimeSynchronization_ASTICreate/Update/Delete message.

Step 602: The AMF sends a time synchronization request message to the TSCTSF. The time synchronization request message includes the identification information of the UE, the required time synchronization error accuracy and indication information.

The identification information of the UE, the required time error accuracy and the indication information in the time synchronization request message sent by the AMF come from the UE.

Step 603: TSCTSF sends a request message to UDM, where the request message includes the identification information of the UE.

When the indication information received by the TSCTSC indicates that time synchronization services are provided for the UE, the request message sent by the TSCTSF to the UDM is used to request to query whether the UE is authorized to provide time synchronization services.

When the indication information received by TSCTSC indicates that time synchronization services are provided for the UE according to the enhanced RTT time synchronization method, the request message sent by TSCTSF to UDM is used to request to query whether it is authorized to provide time synchronization services for the UE according to the enhanced RTT time synchronization method.

When the instruction information received by TSCTSC indicates that the UE is provided with time synchronization services according to the two-way RTT time synchronization method, the request message sent by TSCTSF to UDM is used to request whether to authorize the UE to use the two-way RTT time synchronization method. Provide timely services.

Step 604: UDM sends a response message to TSCTSF.

The response message indicates that the UE is authorized to provide time synchronization services for the UE, or that the UE is authorized to provide time synchronization services for the UE according to the enhanced RTT time synchronization method, or that the UE is authorized to provide time synchronization services for the UE according to the two-way RTT time synchronization method.

Steps 605 to 613 are the same as steps 403 to 411 described above.

In the above scheme, the UE actively requests time synchronization services, and the TSCTSF selects a base station that provides time synchronization services for the UE. The base station sends time synchronization information to the UE. Therefore, when the base station cannot send time synchronization information to the UE, or the base station cannot send time synchronization information to the UE in a timely manner, By sending time synchronization information, the UE can achieve precise time synchronization between the UE and the base station based on the time synchronization information previously received from the base station, which helps to improve the communication capabilities of the UE.

It can be understood that, in order to implement the functions in the above embodiments, the access network device or the terminal device includes corresponding hardware structures and/or software modules that perform each function. Those skilled in the art should easily realize that the units and method steps of each example described in conjunction with the embodiments disclosed in this application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software driving the hardware depends on the specific application scenarios and design constraints of the technical solution.

Figures 7 and 8 are schematic structural diagrams of possible communication devices provided by embodiments of the present application. These communication devices can be used to implement the functions of the access network equipment or terminal equipment in the above method embodiments, and therefore can also achieve the beneficial effects of the above method embodiments. In the embodiment of the present application, the communication device may be an access network device or a terminal device, or may be a module (such as a chip) in the access network device or a module (such as a chip) in the terminal device.

The communication device 700 shown in FIG. 7 includes a processing unit 710 and a transceiver unit 720. The communication device 700 is used to implement the functions of the access network equipment or terminal equipment in the above method embodiment. The transceiver unit 720 may be used to implement corresponding communication functions. The transceiver unit 720 may also be called a communication interface or communication unit. The processing unit 710 may be used to implement corresponding processing functions. Optionally, the communication device 700 further includes a storage unit, which can be used to store instructions and/or data, and the processing unit 710 can read the instructions and/or data in the storage unit, so that the communication device 700 implements each of the foregoing. Actions of terminal equipment (such as UE) or access network equipment (such as base station) in method embodiments.

When the communication device 700 is used to implement the functions of the terminal device in the above method embodiment, the transceiver unit 720 is used to receive time synchronization information from the access network device; the processing unit 710 is used to adjust the time according to the current time of the terminal device, The reception time of the time synchronization information and the time synchronization information are time synchronized.

In a possible implementation method, the processing unit 710 is specifically configured to perform time synchronization based on the current time of the terminal device, the reception time of the time synchronization information, and the time synchronization information when a preset condition is met; wherein, the preset time Assume that the condition is: the terminal device does not receive new time adjustment information from the access network device within a set time period; or the terminal device receives the first indication information and the first indication information from the access network device within a set time period. New time synchronization information, the first indication information indicates that the new time synchronization information does not meet the time synchronization accuracy requirements of the terminal device.

In one possible implementation method, the processing unit 710 is specifically configured to determine the difference between the current time of the terminal device and the reception time of the time synchronization information; determine the synchronization time based on the difference and the time synchronization information; Time synchronization is performed based on the synchronization time.

In a possible implementation method, the time synchronization information includes a clock frequency ratio and a clock deviation. The clock frequency ratio represents a clock frequency ratio between the terminal device and the access network device. The clock deviation represents a clock frequency ratio between the terminal device and the access network device. Clock deviation between access network devices; the processing unit 710 is specifically used to determine the ratio of the difference to the clock frequency ratio; The synchronization time is determined based on the ratio, the clock deviation and the reception time of the time synchronization information.

In a possible implementation method, the time synchronization information includes a clock frequency ratio, a transmission delay and a sending time of the time synchronization information. The clock frequency ratio represents a clock frequency ratio between the terminal device and the access network device, The transmission delay represents the transmission delay between the terminal device and the access network device; the processing unit 710 is specifically used to determine the ratio of the difference to the clock frequency ratio; the processing unit 710 is specifically used to determine the ratio according to the ratio , the transmission delay and the sending time of the time synchronization information determine the synchronization time.

In a possible implementation method, the time synchronization information includes a clock deviation change rate, a clock frequency ratio, and a clock deviation. The clock deviation change rate represents the change of the clock deviation over time, and the clock frequency ratio represents the clock frequency ratio between the terminal device and the interface. The clock frequency ratio between network access devices, the clock deviation represents the clock deviation between the terminal device and the access network device; the processing unit 710 is specifically used to determine the product of the clock deviation change rate and the difference, and Determine the ratio of the product to the clock frequency ratio; the processing unit 710 is specifically configured to determine the synchronization time based on the ratio, the clock deviation and the current time of the terminal device.

In a possible implementation method, the transceiver unit 720 is also configured to receive the set duration from the access network device.

In a possible implementation method, the set time period is preset.

In a possible implementation method, the transceiver unit 720 is also configured to send a time synchronization request message. The time synchronization request message includes identification information of the terminal device and second indication information. The second indication information indicates that the time synchronization request message is provided for the terminal device. On-time service.

In a possible implementation method, the transceiver unit 720 is also used to receive information indicating turning on the time synchronization function.

In a possible implementation method, the time synchronization information includes a transmission delay and a sending time of the time synchronization information. The transmission delay represents the transmission delay between the terminal device and the access network device; the processing unit 710, It is also used to perform time synchronization based on the transmission delay and the sending time of the time synchronization information before performing time synchronization based on the current time of the terminal device, the reception time of the time synchronization information, and the time synchronization information.

When the communication device 700 is used to implement the function of the access network device in the above method embodiment, the processing unit 710 is used to determine the time synchronization information. The time synchronization information includes a clock frequency ratio, and the clock frequency ratio indicates that the terminal equipment and The clock frequency ratio between the access network devices; the transceiver unit 720 is used to send the time synchronization information to the terminal device, and the time synchronization information is used for local time synchronization of the terminal device.

In a possible implementation method, the processing unit 710 is used to determine the first clock deviation at the first time, and determine the second clock deviation at the second time; according to the difference between the second clock deviation and the first clock deviation. The first difference, and the second difference between the second time and the first time, determine the clock bias change rate.

In a possible implementation method, the transceiver unit 720 is also configured to receive indication information indicating that the time synchronization service is provided for the terminal device before the processing unit 710 determines the time synchronization information.

When the communication device 700 is used to implement the function of the clock management network element (such as the TSCTSF network element) in the above method embodiment, the transceiver unit 720 is used to receive a time synchronization request message. The time synchronization request message includes the identification information of the terminal device. and indication information, the indication information indicates that the time synchronization service is provided for the terminal device; the processing unit 710 is used to select the access network device that provides the time synchronization service for the terminal device; the transceiver unit 720 is also used to provide the policy control network element with Send a notification message, which includes the identification information of the terminal device, the identification information of the access network device, and the indication information.

In a possible implementation method, the transceiver unit 720 is also used to send a query message to the unified database network element. The query message includes the identification information of the terminal device, and the query message requests to obtain the policy control network that provides services for the terminal device. element; receiving the identification information of the policy control network element from the unified database network element.

In a possible implementation method, the transceiver unit 720 is also used to send a request message to the unified data management network element. The request message includes the identification information of the terminal device. The request message is used to request to query whether the terminal device is authorized to provide Time synchronization service; receiving a response message from the unified data management network element, the response message indicating authorization to provide time synchronization service for the terminal device.

In a possible implementation method, the transceiver unit 720 is also configured to receive the time request message from the terminal device or application function network element.

More detailed descriptions about the above processing unit 710 and the transceiver unit 720 can be obtained directly by referring to the relevant descriptions in the above method embodiments, and will not be described again here.

The communication device 800 shown in FIG. 8 includes a processor 810 and an interface circuit 820. The processor 810 and the interface circuit 820 are coupled to each other. It can be understood that the interface circuit 820 may be a transceiver or an input-output interface. Optionally, the communication device 800 may also include a memory 830 for storing instructions executed by the processor 810 or input data required for the processor 810 to run the instructions or data generated after the processor 810 executes the instructions.

When the communication device 800 is used to implement the above method embodiment, the processor 810 is used to realize the function of the above processing unit 710, and the interface circuit 820 is used to realize the function of the above transceiver unit 720.

It can be understood that the processor in the embodiment of the present application can be a central processing unit (CPU), or other general-purpose processor, digital signal processor (DSP), or application-specific integrated circuit (application specific integrated circuit, ASIC), field programmable gate array (field programmable gate array, FPGA) 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.

The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. Software instructions can be composed of corresponding software modules, and the software modules 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 In memory, register, hard disk, mobile hard disk, CD-ROM or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage media may be located in an ASIC. Of course, the processor and the storage medium may also exist as discrete components in the base station or terminal.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it may be implemented in whole or in part 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 the computer, the processes or functions described in the embodiments of the present application are executed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a base station, a UE, or other programmable devices. The computer program or instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer program or instructions may be transmitted from a website, computer, Server or data center Transmission to another website, computer, server or data center by wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media, such as floppy disks, hard disks, and tapes; optical media, such as digital video optical disks; or semiconductor media, such as solid-state hard drives. The computer-readable storage medium may be volatile or nonvolatile storage media, or may include both volatile and nonvolatile types of storage media.

In the various embodiments of this application, if there is no special explanation or logical conflict, the terms and/or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments are based on their inherent Logical relationships can be combined to form new embodiments.

In this application, "at least one" refers to one or more, and "plurality" refers to two or more. "And/or" describes the association of associated objects, indicating that there can be three relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A, B can be singular or plural. In the text description of this application, the character "/" generally indicates that the related objects are in an "or" relationship; in the formula of this application, the character "/" indicates that the related objects are in a "division" relationship. Relationship.

It can be understood that the various numerical numbers involved in the embodiments of the present application are only for convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the serial numbers of the above processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic.

Claims

A time synchronization method, characterized by including:

The terminal device receives time synchronization information from the access network device;

The terminal device performs time synchronization based on the current time of the terminal device, the reception time of the time synchronization information, and the time synchronization information.
The method of claim 1, wherein the terminal device performs time synchronization based on the current time of the terminal device, the reception time of the time synchronization information and the time synchronization information, including:

When the preset conditions are met, the terminal device performs time synchronization based on the current time of the terminal device, the reception time of the time synchronization information, and the time synchronization information;

Among them, the preset conditions are:

The terminal device does not receive new time synchronization information from the access network device within a set time period; or,

The terminal device receives first indication information and new time synchronization information from the access network device within a set time period, and the first indication information indicates that the new time synchronization information does not meet the requirements of the terminal device. Time accuracy requirements.
The method according to claim 1 or 2, characterized in that after the terminal device receives the time synchronization information from the access network device, it further includes:

The terminal device stores the reception time of the time synchronization information and the time synchronization information.
The method according to any one of claims 1 to 3, characterized in that the terminal device performs time synchronization based on the current time of the terminal device, the reception time of the time synchronization information and the time synchronization information. ,include:

The terminal device determines a difference between the current time of the terminal device and the reception time of the time information;

The terminal device determines the synchronization time based on the difference and the time synchronization information;

The terminal device performs time synchronization according to the synchronization time.
The method of claim 4, wherein the time synchronization information includes a clock frequency ratio and a clock deviation, and the clock frequency ratio represents a clock frequency ratio between the terminal device and the access network device, The clock deviation represents the clock deviation between the terminal device and the access network device;

The terminal device determines the synchronization time based on the difference and the time synchronization information, including:

The terminal device determines a ratio of the difference to the clock frequency ratio;

The terminal device determines the synchronization time based on the ratio, the clock deviation and the reception time of the time synchronization information.
The method according to claim 4, wherein the time synchronization information includes a clock frequency ratio, a transmission delay and a sending time of the time synchronization information, and the clock frequency ratio indicates that the terminal device is connected to the interface. The clock frequency ratio between network access devices, and the transmission delay represents the transmission delay between the terminal device and the access network device;

The terminal device determines the synchronization time based on the difference and the time synchronization information, including:

The terminal device determines a ratio of the difference to the clock frequency ratio;

The terminal device determines the synchronization time based on the ratio, the transmission delay and the sending time of the time synchronization information.
The method of claim 4, wherein the time synchronization information includes a clock deviation change rate, a clock frequency ratio and a clock deviation, the clock deviation change rate represents the change of the clock deviation over time, and the clock frequency The ratio represents the clock frequency ratio between the terminal device and the access network device, and the clock deviation represents the clock deviation between the terminal device and the access network device;

The terminal device determines the synchronization time based on the difference and the time synchronization information, including:

The terminal device determines a product of the clock deviation change rate and the difference, and determines a ratio of the product to the clock frequency ratio;

The terminal device determines the synchronization time based on the ratio, the clock deviation and the current time of the terminal device.
The method according to any one of claims 2, further comprising:

The terminal device receives the set duration from the access network device.
The method according to any one of claims 2, characterized in that the set duration is preset.
The method according to any one of claims 1 to 9, further comprising:

The terminal device sends a time synchronization request message, the time synchronization request message includes identification information of the terminal device and second indication information, and the second indication information indicates that the time synchronization service is provided for the terminal device.
The method according to any one of claims 1 to 10, further comprising:

The terminal device receives information indicating turning on the time synchronization function.
The method according to any one of claims 1 to 4, characterized in that the time synchronization information includes a transmission delay and a sending time of the time synchronization information, and the transmission delay represents the time between the terminal device and the time synchronization information. Describe the transmission delay between access network devices;

Before the terminal device performs time synchronization based on the current time of the terminal device, the reception time of the time synchronization information and the time synchronization information, it also includes:

The terminal device performs time synchronization based on the transmission delay and the sending time of the time synchronization information.
A time synchronization method, characterized by including:

The access network device determines time synchronization information, the time synchronization information includes a clock frequency ratio, and the clock frequency ratio represents a clock frequency ratio between the terminal device and the access network device;

The access network device sends the time synchronization information to the terminal device, and the time synchronization information is used for local time synchronization of the terminal device.
The method of claim 13, wherein the time synchronization information further includes a clock deviation, and the clock deviation represents a clock deviation between the terminal device and the access network device.
The method according to claim 13, wherein the time synchronization information further includes a transmission delay and a sending time of the time synchronization information, and the transmission delay represents the difference between the terminal equipment and the access network equipment. transmission delay between them.
The method of claim 13, wherein the time synchronization information further includes a clock deviation change rate and a clock deviation. The clock deviation change rate represents the change of the clock deviation over time, and the clock deviation represents the clock deviation. The clock deviation between the terminal equipment and the access network equipment.
The method of claim 16, further comprising:

The access network device determines a first clock offset at a first time and determines a second clock offset at a second time;

The access network device determines the clock offset change based on a first difference between the second clock offset and the first clock offset, and a second difference between the second time and the first time. Rate.
The method according to any one of claims 13 to 17, characterized in that before the access network device determines the time synchronization information, it further includes:

The access network device receives indication information, and the indication information indicates providing time synchronization services for the terminal device.
A communication device, characterized in that it includes a processor and a memory, and the memory is coupled to the processor, The memory is used to store program instructions, and the processor is used to execute the program instructions to implement the method according to any one of claims 1 to 12.
A communication device, characterized in that it includes a processor and a memory, the memory is coupled to the processor, the memory is used to store program instructions, and the processor is used to execute the program instructions to implement claim 13 The method described in any one of to 18.
A computer program product, characterized in that it includes a computer program, and when the computer program is executed by a communication device, the method according to any one of claims 1 to 18 is implemented.
A computer-readable storage medium, characterized in that a computer program or instructions are stored in the storage medium. When the computer program or instructions are executed by a communication device, the implementation as described in any one of claims 1 to 18 is achieved. Methods.
A communication system, characterized in that it includes a terminal device for performing the method according to any one of claims 1 to 12, and an access for performing the method according to any one of claims 13 to 18. network equipment.