CN117812685A

CN117812685A - Information transmission method, device and system

Info

Publication number: CN117812685A
Application number: CN202211209525.7A
Authority: CN
Inventors: 孙海洋
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-09-30
Filing date: 2022-09-30
Publication date: 2024-04-02
Also published as: WO2024066922A9; WO2024066922A1

Abstract

The application provides an information transmission method, device and system, which are used for acquiring real-time and accurate time synchronization error budget so as to provide accurate access layer time for terminal equipment. When a preset event occurs, the SMF network element can report third information; the first network element can receive the first information, and determine a network time synchronization error budget according to the first information, so as to determine an accurate air interface time synchronization error budget, provide accurate access layer time for the terminal equipment, and improve the reliability of network transmission.

Description

Information transmission method, device and system

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to an information transmission method, apparatus, and system.

Background

In the forwarding process of the traditional ethernet, when a large number of data packets arrive at a forwarding port at one instant, the problem of large forwarding delay or packet loss can be caused, so that the traditional ethernet cannot provide services with high reliability and guaranteed transmission delay, and cannot meet the requirements of the fields of automobile control, industrial internet and the like. The institute of electrical and electronics engineers (Institute of Electrical and Electronics Engineers, IEEE) has defined a related time sensitive network (TimeSensitive Networking, TSN) standard for reliable latency transmission that provides reliable latency transmission services based on two-layer switching, guarantees reliability of latency sensitive traffic data transmission, and predictable end-to-end transmission delays.

For real-time communications, time plays an important role in the TSN, and End-to-End (End-to-End) transmission delays have time boundaries that are difficult to negotiate, so that all devices in the network need a common time reference, requiring clocks to be synchronized with each other. In synchronizing clocks, a time synchronization error budget (time synchronization error budget) in the network needs to be considered. For example, a mobile communication network, such as a fifth generation (5th generation,5G) network, provides access stratum time to a terminal device according to a pre-configured time synchronization error budget. However, in practical applications, due to the dynamics of the network, the actual time synchronization error budget is also dynamically changed, and if the access layer time is provided to the terminal device by using the preconfigured time synchronization error budget, a problem of inaccurate clock exists.

How to obtain real-time and accurate time synchronization error budget and provide accurate access layer time for terminal equipment is a technical problem to be solved.

Disclosure of Invention

The application provides an information transmission method, device and system, which are used for acquiring real-time and accurate time synchronization error budget so as to provide accurate access layer time for terminal equipment.

In a first aspect, there is provided an information transmission method, including: the first network element receives first information; the first network element determines network time synchronization error budget of the PDU session according to the first information; the first network element determines an air interface time synchronization error budget for the PDU session based on the network time synchronization error budget.

In the above scheme, the first network element obtains the network time synchronization error budget according to the first information sent by other network elements (such as the SMF network element or the PCF network element) in the network, so as to determine the accurate Uu time synchronization error budget and provide the terminal equipment with accurate access layer time. The scheme can improve the instantaneity of the time synchronization error budget acquired by the first network element and can improve the reliability of network transmission.

In one possible design, the first information includes a network time synchronization error budget.

In this way, the first network element can directly receive the network time synchronization error budget, and the calculation process is omitted.

In one possible design, the first information may further include one or more of the following: the identification of the data network corresponding to the PDU session, the identification of the network slice corresponding to the PDU session, and the application information corresponding to the PDU session.

In this way, the first network element can determine which data network or network slice or network time synchronization error budget of the applied PDU session the network time synchronization error budget in the first information is, which can improve the scheme reliability.

In one possible design, the third information may include calculation parameters for determining a changed network time synchronization error budget. By way of example, the third information may include one or more of the following: the identification of the user plane function network element and/or the identification of the access network element corresponding to the PDU session; the clock type and/or clock precision of the user plane function network element and/or the access network element corresponding to the PDU session.

In this way, the network element reporting the third information may omit the process of calculating the network time synchronization error budget.

In this way, the first network element may determine that the calculation parameter in the first information is a parameter for calculating which data network or network slice or network time synchronization error budget of the applied PDU session, which may improve the scheme reliability.

In one possible design, the first network element determines a network time synchronization error budget for the PDU session based on the first information, comprising: the first network element determines network time synchronization error budget of the PDU session according to network topology information corresponding to the PDU session and/or clock type and/or clock precision of a user plane function network element and/or an access network element corresponding to the PDU session; the network topology information comprises information of each node and an adjacent relation between the nodes on a first path, wherein the first path is a path between a user plane function network element and an access network element.

In the method, the first network element can determine the network time synchronization error budget according to one or more items of network topology information, a user plane function network element corresponding to the PDU session, and/or a clock type and/or clock precision of the access network element, and the scheme is flexible and high in reliability.

In one possible design, the network topology information further includes: the time synchronization error budget for each node on the first path and/or the transmission time synchronization error budget between the nodes.

In this way, the first network element may directly accumulate the time synchronization error budget of each node and/or the transmission time synchronization error budget between the nodes on the first path to obtain the network time synchronization error budget of the PDU session.

In one possible design, the first information further includes network topology information corresponding to the PDU session, and the first network element may directly obtain the network topology information corresponding to the PDU session from the first information; or the first network element acquires the network topology information corresponding to the PDU session from the OAM or CNC according to the first information.

In this way, the first network element obtains the network topology information in multiple implementation manners, so that the flexibility of the scheme can be improved.

In one possible design, the first network element determines a network time synchronization error budget for the PDU session based on the first information, comprising: the first network element sends a first request to the OAM or CNC, wherein the first request comprises first information; the first network element receives a first response from the OAM or CNC, the first response including a network time synchronization error budget for the PDU session.

In this way, the OAM or CNC calculates the network time synchronization error budget, which can reduce the amount of computation of the first network element.

In one possible design, the first network element may further send second information to the PCF network element or the SMF network element, where the second information is used to configure the PCF network element or the SMF network element to report the first information.

In this manner, the PCF network element or the SMF network element may report the first information.

In one possible design, the second information includes an identification of the preset event.

In this way, the PCF network element or the SMF network element may report the first information after the preset event occurs.

In one possible design, the preset event may include one or more of the following: the user plane function network element and/or the access network element corresponding to the PDU session are changed; the network topology information corresponding to the PDU session changes; the clock type of the user plane function network element and/or the access network element corresponding to the PDU session is changed; the clock precision of the user plane function network element and/or the access network element corresponding to the PDU session is changed; the network time synchronization error budget corresponding to the PDU session changes.

It should be appreciated that the above preset events are merely examples and are not limiting.

In one possible design, the first network element is a TSC TSF network element or a TSN AF network element.

Of course, this is merely an example, and other network elements that need to determine the network time synchronization error budget are actually possible, which is not limited in this application.

In a second aspect, there is provided an information transmission method, including: the PCF network element receives third information from the SMF network element; the PCF network element sends first information to the first network element, wherein the first information is third information or the first information is determined according to the third information, and the first information is used for determining network time synchronization error budget of PDU session.

In the scheme, the PCF network element can report the first information to the first network element after receiving the third information reported by the SMF network element, so that the first network element can obtain the network time synchronization error budget, and the reliability of network transmission can be improved.

In one possible design, the first information and the third information are the same. For example, the first information and the third information each comprise the network time synchronization error budget, and the third information comprises the network time synchronization error budget. Optionally, the first information and the third information may further include one or more of: the identification of the data network corresponding to the PDU session, the identification of the network slice corresponding to the PDU session, and the application information corresponding to the PDU session.

In this way, the PCF network element directly penetrates the network time synchronization error budget, and the PCF network element does not need to participate in the calculation of the network time synchronization error budget.

In one possible design, the first information and the third information are the same. For example, the first information and the third information may each include one or more of: the identification of the user plane function network element and/or the identification of the access network element corresponding to the PDU session; the clock type and/or clock precision of the user plane function network element and/or the access network element corresponding to the PDU session. Optionally, the first information and the third information may further include one or more of: the identification of the data network corresponding to the PDU session, the identification of the network slice corresponding to the PDU session, and the application information corresponding to the PDU session.

In the mode, the PCF network element directly transmits the calculation parameters of the network time synchronization error budget, and the PCF network element does not need to participate in the calculation of the network time synchronization error budget.

In one possible design, the first information includes a network time synchronization error budget; the third information may include one or more of the following: the identification of the user plane function network element and/or the identification of the access network element corresponding to the PDU session; the clock type and/or clock precision of the user plane function network element and/or the access network element corresponding to the PDU session. Optionally, the first information and the third information may further include one or more of: the identification of the data network corresponding to the PDU session, the identification of the network slice corresponding to the PDU session, and the application information corresponding to the PDU session.

In this way, the PCF network element receives the calculation parameter of the network time synchronization error budget, and determines the network time synchronization error budget according to the calculation parameter, so as to reduce the calculation amount of the SMF network element or the first network element.

In one possible design, the PCF network element may also receive second information from the first network element; and sending the first information to the first network element according to the second information.

In this way, the PCF network element can be configured by the first network element to report the first information, thereby improving the reliability of the scheme.

In one possible design, the second information includes an identification of a preset event.

In this manner, the PCF network element may be configured to report the first information after the occurrence of the preset event.

In one possible design, the PCF network element may further send fourth information to the SMF network element according to the second information, where the fourth information is used to configure the SMF network element to report the third information.

In this way, the PCF network element may further configure the SMF network element to report the third information, and then may report the first information according to the third information.

In one possible design, the fourth information includes an identification of a preset event.

In this manner, the PCF network element may configure the SMF network element to report the third information after the preset event occurs.

In one possible design, the preset event may include one or more of the following:

the user plane function network element and/or the access network element corresponding to the PDU session are changed;

the network topology information corresponding to the PDU session changes;

the clock type of the user plane function network element and/or the access network element corresponding to the PDU session is changed;

the clock precision of the user plane function network element and/or the access network element corresponding to the PDU session is changed;

the network time synchronization error budget corresponding to the PDU session changes.

Of course, the foregoing are by way of example only and not limiting.

In a third aspect, there is provided an information transmission method, including: the SMF network element determines the occurrence of a preset event; the SMF network element sends third information, wherein the third information is first information or third information is used for determining the first information, and the first information is used for determining network time synchronization error budget of the PDU session.

In the scheme, after the preset event occurs, the SMF network element can report the third information in time, so that the first network element can obtain the network time synchronization error budget after the preset event occurs, and the reliability of network transmission can be improved.

In one possible design, the SMF network element receives fourth information from the PCF network element; and the SMF network element sends the third information to the PCF network element according to the fourth information.

In this manner, the SMF network element may be configured to report the third information.

In this manner, the SMF network element may be configured to report the third information after the preset event occurs.

the network topology information corresponding to the PDU session changes;

Of course, the foregoing are by way of example only and not limiting.

In a fourth aspect, there is provided a communication device comprising means or units or technical means for performing the method described in the first aspect or any one of the possible designs of the first aspect.

For example, an apparatus may include:

the receiving and transmitting module is used for receiving the first information;

a processing module for determining a network time synchronization error budget for the PDU session based on the first information; and determining the air interface time synchronization error budget of the PDU session according to the network time synchronization error budget.

In a fifth aspect, there is provided a communication device comprising means or units or technical means for performing the method described in the second aspect or any one of the possible designs of the second aspect.

For example, an apparatus may include:

the receiving and transmitting module is used for receiving third information from the SMF network element;

the transceiver module is further configured to send first information to the first network element, where the first information is third information or the first information is determined according to the third information, and the first information is used to determine a network time synchronization error budget of the PDU session.

In a sixth aspect, there is provided a communication device comprising means or units or technical means for performing the method described in the third aspect or any one of the possible designs of the third aspect.

For example, an apparatus may include:

the processing module is used for determining the occurrence of a preset event;

and the transceiver module is used for transmitting third information, wherein the third information is first information or the third information is used for determining the first information, and the first information is used for determining the network time synchronization error budget of the PDU session.

In a seventh aspect, there is provided a communication device comprising a processor and interface circuitry for receiving signals from or transmitting signals to a processor other than the communication device, the processor being operable by logic circuitry or executing code instructions to implement the method as described in the first aspect or any one of the possible designs of the first aspect, or to implement the method as described in the second aspect or any one of the possible designs of the second aspect, or to implement the method as described in the third aspect or any one of the possible designs of the third aspect.

In an eighth aspect, a computer readable storage medium is provided, in which a computer program or instructions is stored which, when executed by a communication device, carries out the method as described in the first aspect or any one of the possible designs of the first aspect, or carries out the method as described in the second aspect or any one of the possible designs of the second aspect, or carries out the method as described in the third aspect or any one of the possible designs of the third aspect.

In a ninth aspect, embodiments of the present application provide a computer program product for implementing a method as described in the first aspect or any one of the possible designs of the first aspect, or for implementing a method as described in the second aspect or any one of the possible designs of the second aspect, or for implementing a method as described in the third aspect or any one of the possible designs of the third aspect, when the computer program product is run on a processor.

In a tenth aspect, there is provided a communication system comprising: a first network element for performing the method as in the first aspect or any one of the possible designs of the first aspect;

a PCF network element configured to perform the method as described in the second aspect or any one of the possible designs of the second aspect;

an SMF network element for performing the method as described in the third aspect or any one of the possible designs of the third aspect.

Effects of any of the fourth to tenth aspects are described with reference to effects of the corresponding aspects of the first to third aspects, and repetitive matters will not be repeated.

Drawings

Fig. 1A and fig. 1B are schematic diagrams of a network architecture applicable to the embodiments of the present application;

FIG. 2 is a system architecture diagram of interworking of a 3GPP network and a TSN;

FIG. 3 is a system architecture diagram of a 3GPP network supporting delay-sensitive communications in a non-TSN network scenario;

FIG. 4 is a schematic diagram of a time synchronization model of a 5G supported TSN network;

FIG. 5 is a schematic diagram of a time synchronization model of a 5G supported TSN network;

fig. 6 is a flowchart of a TSCTSF network element providing a 5G access stratum time distribution indication and Uu time synchronization error budget to the NG-RAN;

fig. 7 is a flowchart of an information transmission method provided in an embodiment of the present application;

fig. 8 is a flowchart of an SMF network element acquiring network topology information from OAM;

fig. 9 is a flowchart of another information transmission method according to an embodiment of the present application;

fig. 10 is a flowchart of another information transmission method according to an embodiment of the present application;

fig. 11 is a schematic diagram of a communication device according to an embodiment of the present application;

fig. 12 is a schematic diagram of another communication device according to an embodiment of the present application.

Detailed Description

The technical solution of the embodiment of the application can be applied to various communication systems, for example: the fourth generation (4th generation,4G) communication system, the fifth generation (5th generation,5G) communication system, the sixth generation (6th generation,6G) communication system, or other future evolution systems, or various other wireless communication systems employing wireless access technologies, and the like, are not limited in this application. The following takes the application of the technical solution of the embodiment of the present application to a 5G communication system as an example.

Referring to fig. 1A, a schematic diagram of a network architecture, such as a service architecture of a 5G network, and a non-roaming network architecture, is shown in the embodiment of the present application. The 5G network includes a radio access network (radio access network, (R) AN), a user plane function (user plane function, UPF), AN access and mobility management function (access and mobility management function, AMF), a session management function (session management function, SMF), AN authentication server function (authentication server function, AUSF), a network slice selection function (network slice selection function, NSSF), a network opening function (network exposure function, NEF), a network storage function (network repository function, NRF), a policy control function (policy control function, PCF), a unified data management (unified data management, UDM), a unified data storage (unified data repository, UDR), AN application function (application function, AF) or a billing function (charging function, CHF), a binding support function (Binding Support Function, BSF), and the like. It should be noted that fig. 1A is only an example of some network elements or entities in a 5G network, and the 5G network may further include some network elements or entities not illustrated in fig. 1A, such as a network data analysis function (network data analytics function, NWDAF), which is not limited in this embodiment of the present application.

As shown in fig. 1A, a User Equipment (UE) accesses a 5G network through AN (R) AN, and the UE communicates with AN AMF through AN N1 interface (N1 for short); (R) the AN communicates with the AMF through AN N2 interface (N2 for short); (R) the AN communicates with the UPF via AN N3 interface (N3 for short); the SMF communicates with the UPF through an N4 interface (abbreviated as N4), and the UPF accesses a Data Network (DN) through an N6 interface (abbreviated as N6). In addition, the control plane functions such as AUSF, AMF, SMF, NSSF, NEF, NRF, PCF, UDM, UDR, CHF, BSF and AF shown in fig. 1A interact with each other by using a service interface. For example, the server interface provided by the AUSF is Nausf; the AMF provides a service interface as Namf; the SMF provides a service interface as Nsmf; the NSSF provides a service interface for the outside as Nnssf; the NEF provides a service interface for the outside as Nnef; the service interface externally provided by the NRF is Nnrf; the PCF provides a service interface for the outside as an Npcf; the service interface externally provided by the UDM is Nudm; the service interface externally provided by the UDR is Nudr; the service interface provided by CHF is Nchf; the BSF provides a service interface for the outside, which is Nbsf; the service interface provided by the AF is Naf. The relevant functional descriptions and interface descriptions may refer to the 5G system architecture (5G system architecture) diagram in the 23501 standard, which is not listed here.

Please refer to fig. 1B, which is a schematic diagram of another network architecture applicable to the embodiment of the present application, wherein the network architecture is a non-roaming network architecture. In this network architecture, network elements such as NSSF, AUSF, UDM, UE, (R) AN, PCF, and SMF can communicate with the AMF. The AUSF can also communicate with UDM, UDM can also communicate with SMF, and SMF can communicate with UPF and PCF in addition to AMF and UDM. The PCF is also capable of communicating with AF and NEF. The NEF can also communicate with the AF. The UPF is able to communicate with the (R) AN and DN. In fig. 1B, "Nxx" between two network elements represents an interface between the two network elements. For example, N22 represents an interface between NSSF and AMF, N12 represents an interface between AUSF and AMF, N8 represents an interface between UDM and AMF, and so on. In this scenario, the BSF network element may be deployed separately, or may be integrated with other network elements, which is not limited in this application. Fig. 1B does not show BSF network elements.

It should be noted that, in the non-roaming scenario shown in fig. 1A or fig. 1B, the UE is equivalent to being in the home public land mobile network (home public land mobile network, HPLMN), and the PCF is equivalent to the PCF in the HPLMN, and thus may be called an H-PCF, an hPCF, or an hPCF; AMF is equivalent to AMF in HPLMN and thus may be referred to as H-AMF, H-AMF, hAMF or HAMF; CHF corresponds to CHF in HPLMN and may therefore be referred to as H-CHF, hCHF or hCHF.

It should be noted that, the application function network element, the binding support function network element, the policy control network element, the session management network element, and the like related to the embodiments of the present application are just one name, and the name does not limit the device itself. Taking a 5G system as an example, the application function network element is, for example, AF, the policy control network element is, for example, PCF, the session management network element is, for example, SMF, and the binding support function network element is BSF. In a non-5G system, for example, in other future communication systems, an application function network element, a policy control network element, a session management network element, a binding support function network element, and the like may also correspond to other network elements, which is not specifically limited in the embodiment of the present application.

The following describes the functions of the network elements and devices mainly related to the embodiments of the present application.

A terminal may also be referred to as a terminal device, user Equipment (UE), mobile station, mobile terminal, etc. The terminal may be widely applied to various scenes, for example, device-to-device (D2D), vehicle-to-device (vehicle to everything, V2X) communication, machine-type communication (MTC), internet of things (internet of things, IOT), virtual reality, augmented reality, industrial control, autopilot, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, and the like. The terminal can be a mobile phone, a tablet personal computer, a computer with a wireless receiving and transmitting function, a wearable device, a vehicle, an unmanned aerial vehicle, a helicopter, an airplane, a ship, a robot, a mechanical arm, intelligent household equipment and the like. The embodiment of the application does not limit the specific technology and the specific equipment form adopted by the terminal.

(R) AN network element: the Network elements for providing Access to the terminal Network elements include radio Access Network (Radio Access Network, RAN) Network elements and Access Network (AN) Network elements. The RAN network element is mainly a 3GPP network radio network element, and the AN may be a non-3GPP defined access network element. Radio access network (Radio Access Network, RAN) network element: mainly responsible for radio resource management, quality of service (quality of service, qoS) management, data compression, encryption, etc. functions on the air interface side. The RAN network elements may comprise various forms of base stations, such as: macro base stations, micro base stations (also referred to as small stations), relay stations, access points, and the like. In systems employing different radio access technologies, the names of network elements with base station functionality may be different, e.g. in fifth generation (5th generation,5G) systems, called RAN or gNB (5 GNodeB); in the LTE system, it is called evolved NodeB (eNB or eNodeB); in the third generation (3rd generation,3G) system, it is called a Node B (Node B) or the like. The AN network element allows interworking between the terminal network element and the 3GPP core network using non-3GPP technologies, for example: wireless fidelity (Wireless Fidelity, wi-Fi), worldwide interoperability for microwave access (Worldwide Interoperability for Microwave Access, wiMAX), code division multiple access (Code Division Multiple Access, CDMA) networks, and the like.

The (R) AN network element and the terminal may be fixed in location or may be mobile. (R) AN network elements and terminals may be deployed on land, including indoor or outdoor, hand-held or vehicle-mounted; the device can be deployed on the water surface; but also on aerial planes, balloons and satellites. The embodiment of the application does not limit the application scene of the (R) AN network element and the terminal.

Access and mobility management function (access and mobility management function, AMF) network element: is mainly responsible for mobility management in mobile networks, such as user location update, user registration network, user handover, etc.

Session management function (Session Management Function, SMF) network element: may be abbreviated as SMF, and is mainly responsible for session management in mobile networks, such as session establishment, modification, release. Specific functions are for example assigning IP addresses to users, selecting UPFs providing message forwarding functions, etc.

User plane function (User Plane Function, UPF) network element: may be abbreviated as UPF, responsible for forwarding and receiving user data in a terminal device. User data can be received from the data network and transmitted to the terminal equipment through the access network equipment; the UPF network element may also receive user data from the terminal device via the access network device and forward the user data to the data network. The transmission resources and scheduling functions in the UPF network element that serve the terminal device are managed and controlled by the SMF network element.

Policy control function (policy control function, PCF) network element: the method can be called PCF for short, mainly supports the provision of a unified policy framework to control network behavior, provides policy rules for a control layer network function, and is responsible for acquiring user subscription information related to policy decision.

Network open function (Network Exposure Function, NEF) network element: may be abbreviated as NEF, primarily for supporting the opening of capabilities and events.

-application function (Application Function, AF) network element: may be abbreviated as AF, mainly support interactions with the 3GPP core network to provide services, such as influencing data routing decisions, policy control functions or providing some services of third parties to the network side.

Unified data management (Unified Data Management, UDM) network element: may be referred to as UDM for short, for generating authentication credentials, user identification processes (e.g., storing and managing user permanent identities, etc.), access authorization control, subscription data management, etc.

Data Network (DN): is a Service network providing a data transmission Service for a user, such as an IMS (IP multimedia Service), the Internet (Internet), etc.

The UE accesses a Data Network (DN) through a PDU (Packet Data Unit) session established between the UE and the DN.

Referring to fig. 2, there is a system architecture diagram of a third generation partnership project (3rd Generation Partnership Project,3GPP) network and TSN interworking, in which the 5G system (5G system,5 GS) is integrally formed as a logical TSN Bridge (Bridge) comprising TSN converters for use as the TSN system and the TSN interworking. The functions of the TSN converter include a Device-side TSN converter (Device-side TSN translator, DS-TT) and a Network-side TSN converter (Network-side TSN translator, NW-TT). The specific flow of 5GS at the 5G core network and access network (Radio Access Network, RAN) is transparent to the TSN system, and to ensure this transparency, the 5GS provides TSN ingress and egress port information to the TSN system through the DS-TT and NW-TT. The 5GS exchanges information with nodes in the TSN network through a TSN AF network element (TSN AF network element, which may be understood as an AF network element supporting TSN), the exchanged information including: 5GS network bridge capability information, TSN configuration information, time scheduling information of TSN input/output ports, time synchronization information and the like.

The 5GS bridge includes a port on the anchor User plane function (User Plane Function, UPF) element side, a User plane tunnel between a terminal (UE) and the UPF element, and a port on the DS-TT side. For each 5GS bridge, the NW-TT side port supports connectivity to the TSN network, and the DS-TT side port is associated with a Packet Data Unit (PDU) session while also providing connectivity to the TSN network.

Referring to fig. 3, a system architecture diagram of a 3GPP network supporting delay-sensitive communications in a non-TSN network scenario is shown, where for the non-TSN scenario, a clock synchronization service is supported by adding a time synchronization function (Time Synchronization Function, TSF) network element (which may be understood as a TSF network element supporting a TSC protocol) for delay-sensitive communications (Time Sensitive Communication, TSC), and TSC traffic in the non-TSN scenario is enabled. Wherein the functions of the TSCTSF gateway include:

(1) Associating a time synchronized service request from an AF network element to an AF session;

(2) And a DS-TT/NW-TT interactive port management information container (Port Management Information Container, PMIC)/user plane node management information container (User plane node Management Information Container, UMIC) for managing and controlling DS-TT/NW-TT;

(3) Detecting availability of 5GS network bridge or 5GS node information reported by PCF network elements;

(4) Creating a TSC support container (Assistance Container) according to the service type parameters provided by the AF/network opening function (Network Exposure Function, NEF) and providing the TSC support container to the PCF network element;

(5) A 5GS bridge Delay (Delay) is determined based on the UE-DS-TT residence time and provided to the PCF network element.

Referring to fig. 4, a time synchronization model of a TSN network is supported for 5G. When the clocks are synchronized, the whole UE, RAN, UPF network element is regarded AS a 5GS Bridge or a 5GS node, the 5GS Bridge is connected with other TSN devices through a TSN link, and the parameter transmission is carried out by adopting the time synchronization principle of an 802.1AS protocol or an IEEE 1588 protocol. The external TSN and TSC clocks are used as a main clock source (i.e., (g) PTPGM), the time delay required for transmitting accurate time protocol (Precision Time Protocol, PTP) information is accurately calculated in the 5GS, and the TSN and TSC clocks are time-given to the DS-TT of the UE side; conversely, the DS-TT side clock may also clock the Data Network (DN) side clock. UE, RAN, UPF to the 5GS internal clock (i.e., 5G GM), the UE (or DS-TT on the UE side) acquires timing of the 5GS internal clock. The 5GS may deliver universal precision time protocol (Generic Precision Time Protocol, gPTP) messages for multiple TSN clock domains simultaneously.

Referring to fig. 5, a time synchronization model of a TSN network is supported for 5G. By using the 5GS internal clock synchronization, the time delay of the message in the 5GS can be accurately calculated, and a PTP packet head is set for time delay compensation (correctionfield) to finish the time service from the TSN clock to the End Station (End Station).

There are two methods for the UE to synchronize to the 5G clock: 1) The next generation node B (next generation Node B, gNB) broadcasts clock information via system information blocks (System Information Block, SIBs); 2) And the gNB sends 5G time service to the UE through the RRC unicast message.

In a specific implementation, the AF network element may request a time synchronization allocation method, where the request may carry a time synchronization error budget (time synchronization error budget). It will be appreciated that the time synchronization error budget herein defines an upper limit for the 5 GS-introduced time synchronization error, which is referred to as the 5GS time synchronization error budget for ease of distinction.

If the AF network element includes a 5GS time synchronization error budget in the request, the TSCTSF network element may derive a time synchronization error budget available to the next generation radio access network (Next Generation Radio Access Network, NG-RAN) to provide a 5G access layer time (hereinafter referred to as an air interface time synchronization error budget (Uu time synchronization error budget) or Uu time synchronization error budget) to each target UE over the Uu interface. The TSCTSF network element uses the 5GS time synchronization error budget provided by the AF (either directly or through the NEF network element) to derive the air-interface time synchronization error budget.

In order to derive the air time synchronization error budget for each target UE, the TSCTSF network element considers the following factors:

1) A selected time synchronization distribution method (time distribution methods) (e.g., 5G access stratum time distribution (5 Gaccess stratum time distribution), or (G) PTP-based time distribution ((G) PTP based time distribution));

2) Whether the 5GS operates as a boundary clock and acts as a master clock (GM), or whether a clock connected to the DS-TT/NW-TT acts as a GM in the case of time distribution based on (g) PTP;

3) PTP port status in (g) PTP based time distribution case;

4) The CN portion of the time synchronization error budget (i.e., network time synchronization error budget (CN parts of the time synchronization error budget), abbreviated CN error budget, representing the time synchronization error budget from the UPF to the RAN) and the device portion (i.e., device time synchronization error budget (Device parts of the time synchronization error budget), abbreviated Device error budget, identifying the time synchronization error budget between the DS-TT to the UE). The device time synchronization error budget may be predefined or calculated by 5GS by implementation-based means.

For example, 5GS time synchronization error budget = CN time synchronization error budget + Uu time synchronization error budget + device time synchronization error budget. Of course, this is by way of example only and does not exclude other possibilities.

It can be understood that, in order to facilitate distinguishing the time synchronization error budgets on each node or road segment, the upper definition of the time synchronization error introduced by 5GS is referred to as a 5GS time synchronization error budget, the time synchronization error budget between DS-TT and UE is referred to as a device time synchronization error budget, the time synchronization error budget between UPF and RAN is referred to as a CN time synchronization error budget, and the time synchronization error budget between RAN and UE is referred to as an air time synchronization error budget, in which, in practical cases, the 5GS time synchronization error budget, the CN time synchronization error budget, the Uu time synchronization error budget, and the device time synchronization error budget may be respectively named in other manners.

If the AF network element does not contain a 5GS time synchronization error budget in the request, the TSCTSF network element may use the preconfigured 5GS time synchronization error budget to derive the Uu time synchronization error budget. On this basis, the NG-RAN may provide the UE with 5G access layer time according to the Uu interface time synchronization error budget provided by the TSCTSF network element.

Referring to fig. 6, a flowchart for providing a 5G access layer time distribution indication and Uu time synchronization error budget to an NG-RAN for a TSCTSF network element, comprising:

S601, a mobility management (Access and mobility Management, AM) policy association is established. The PCF network element in this step is a PCF network element served by the UE (PCF for a UE), which may be simply referred to as AM-PCF.

S602, the AF network element sends a request to the NEF (when the AF network element request trigger affects the 5G access stratum time distribution), the request being for create/update/delete/acquire traffic operations.

When the request is for creating a service operation, the AF network element may provide access stratum time distribution parameters to the NEF network element using the nnef_asti_create service operation, including a target identity (e.g., a UE identified by a subscription permanent identity (Subscription Permanent Identifier, SUPI) or a generic public subscription identity (Generic Public Subscription Identifier, GPSI), or a group of ue.nef network elements identified by an external group identifier may map the external group identifier to an internal group identifier, mapping any GPSI to SUPI).

When the request is used for updating or deleting the service operation, the AF network element can call the Nnef_ASTI_update or the Nnef_ASTI_delete service operation to provide corresponding time synchronization configuration identification (Identity document, ID).

When the request is for acquiring a service operation, the AF network element may invoke an nnef_asti_get service operation to provide a target (UE identity list (SUPI or GPSI)).

It is understood that S601 and S602 do not limit the order of precedence.

S603, the NEF network element forwards the request to the TSCTSF network element.

When the procedure is triggered by a PTP instance activation, modification or deactivation in the TSCTSF network element, if the time synchronization error budget is provided by the AF network element, the TSCTSF may use the PTP port status of each DS-TT to determine the Uu time synchronization error budget of the corresponding SUPI as part of the PTP instance. If the time synchronization error budget is provided by the AF network element, the TSCTSF calculates the air-interface time synchronization error budget.

S604, if the request of the AF network element is for a group of UEs, the TSCTSF network element may use the nudm_sdm_get request to retrieve subscription information (e.g. SUPI list) from the UDM using the internal group ID.

S605. the udm network element provides a nudm_sdm_get response, which contains a SUPI list identifying UEs belonging to the UE group.

S606, the TSCTSF network element uses SUPI as an input parameter, and uses Nbsf_management_subscient to request PCF identification associated with SUPI from the BSF network element.

S607, the BSF network element provides the PCF identification of the SUPI requested by the UE to the TSCTSF network element through Nbsf_management_notify operation.

S608, the TSCTSF network element uses the npcf_amppolicy grant request to send a modification request to the PCF for the UE (SUPI identification) AM policy, including a 5G access stratum time distribution indication (enabled, disabled) and optionally the calculated Uu time synchronization error budget.

S609, if the PCF network element receives multiple time synchronization error budgets for a given UE, the PCF network element selects the strictest budget. The PCF network element makes policy decisions, and then the PCF network element can initiate an AM policy association modification flow of the UE to the AMF network element, and provide 5G access layer time distribution parameters to the AMF network element. The PCF network element may subscribe to a certain data network identifier (data network name, DNN) with respect to a binding support function (Binding Support Function, BSF) network element, and the single network slice selects establishment and release of a PDU session of assistance information (Single Network Slice Selection Assistance Information, S-nsai) or subscribes to a PCF corresponding to a certain DNN, S-nsai (i.e., PCF managing the PDU session, PCF for a PDU Session, which may be abbreviated as SM-PCF) with respect to the BSF network element, and subscribes to opening or closing of a certain application with respect to the PCF network element.

Optionally, the AMF network element should store the 5G access layer time distribution indication (enabled, disabled) and Uu time synchronization error budget in the UE context in the AMF network element in case of TSN support, and send the 5G access layer time distribution indication (enabled, disabled) and Uu time synchronization error budget when available. NG-RAN during service request, N2 handover and Xn handover. If the NG-RAN supports TSN, the NG-RAN node should store information in the UE context. Based on this information, the NG-RAN node may provide the UE with 5GS access layer time based on the Uu time synchronization error budget provided by the TSCTSF network element (if supported by the UE and NG-RAN).

S610, the PCF network element of the UE replies an AM strategy association modification result to the TSCTSF network element.

S611, the TSCTSF network element returns a create/update/delete/acquire service operation response to the NEF network element.

S612, the NEF network element notifies the AF network element to create/update/delete/obtain the service operation response.

In the above scheme, the 5GS obtains the time synchronization error budget (i.e. CN time synchronization error budget) between the RAN and the UPF based on implementation, for example, the CN time synchronization error budget is obtained according to the configuration.

In an actual network, however, the CN time synchronization error budget is dynamically changing. For example, the network may support different clock types, such as global navigation satellite system (Global Navigation Satellite System, GNSS) clocks or back-up clocks); the accuracy of the clock may also vary, such as degradation; or the relative positions of RAN and UPF network elements may change during mobility, etc., which may result in a large change in CN time synchronization error budget. The Uu time synchronization error budget generated by the TSCTSF based on the above method is thus no longer accurate.

In order to solve the technical problems, a technical scheme of the embodiment of the application is provided. When the CN time synchronization error budget changes, network elements (such as SMF or PCF) in the network may report relevant change parameters, so that the first network element (such as TSCTSF or TSN AF) may obtain the changed CN time synchronization error budget according to the reported parameters, thereby determining an accurate Uu time synchronization error budget, and providing accurate access layer time for the terminal device.

Referring to fig. 7, a flowchart of an information transmission method according to an embodiment of the present application may be applied to the scenario shown in fig. 1A or fig. 1B or fig. 2 or fig. 3. The method comprises the following steps:

s701, the SMF network element determines that a preset event occurs.

In one possible design, the preset event may be an event that causes a change in the network time synchronization error budget for a certain PDU session. For example, the preset event may include one or more of the following:

1) The UPF network element and/or (R) AN network element corresponding to the PDU session changes;

it can be understood that the network time synchronization error budget of the PDU session mainly refers to the time synchronization error budget on the path from the UPF network element to the (R) AN network element corresponding to the PDU session. Therefore, after the UPF network element or (R) AN network element corresponding to the PDU session is switched, the network time synchronization error budget of the PDU session is affected.

2) The network topology information corresponding to the PDU session changes;

it can be understood that the network topology information corresponding to the PDU session mainly refers to the network topology information on the path from the UPF network element to the (R) AN network element corresponding to the PDU session.

3) The clock type or clock precision of the UPF network element and/or the (R) AN network element corresponding to the PDU session is changed;

it will be appreciated that the UPF network element and/or the (R) AN network element may support multiple clock types, where different clock types may correspond to different network time synchronization error budgets, and thus the clock types of the UPF network element and/or the (R) AN network element may change and may also affect the network time synchronization error budget of the PDU session.

It will be appreciated that the UPF network element and/or the (R) AN network element may support clocks of various accuracies, where different accuracies may correspond to different network time synchronization error budgets, and thus that the clock accuracies of the UPF network element and/or the R (AN) network element may change and may also affect the network time synchronization error budget of the PDU session. In some possible implementations, different clock types may correspond to different accuracies.

The clock type or precision change may refer to one or more of clock domain, reference time of clock, synchronization state (synchronization state), master clock source information (e.g., one or more of type, quality, lock state), related PTP data set parameters (e.g., clock class), traceability information, stability, and clock precision (e.g., precision level) information.

It will be appreciated that the above are examples only, and that there may actually be other events that result in a change in the network time synchronization error budget of the PDU session.

In another possible design, the predetermined event may be a change in the network time synchronization error budget. For example, after the SMF determines that the UPF network element and/or the (R) AN network element corresponding to the PDU session changes, or network topology information corresponding to the PDU session changes, or clock type or accuracy of the UPF network element and/or the (R) AN network element corresponding to the PDU session changes, it may further determine that the network time synchronization error budget changes, and further determine that a preset event occurs. The specific implementation manner of the SMF determining that the UPF network element and/or the (R) AN network element corresponding to the PDU session changes, or the network topology information corresponding to the PDU session changes, or the clock type or the precision of the UPF network element and/or the (R) AN network element corresponding to the PDU session changes, etc. may refer to the above related description, and will not be repeated herein.

Alternatively, the PDU session herein may be a PDU session corresponding to a specific data network, a network slice, or application information.

S702, the SMF network element sends third information, and the PCF network element receives the third information.

In one possible design, the third information may include a changed network time synchronization error budget. In other words, when a preset event occurs, the SMF network element may determine and report the changed network time synchronization error budget.

There are various implementations of the SMF network element to determine the changed network time synchronization error budget, of which several possible ways are exemplified below:

mode 1, each "RAN and UPF" pair may be configured on the smf network element, and optionally a network time synchronization error budget corresponding to clock accuracy and/or clock type. And after the preset event occurs, the SMF network element can directly inquire and obtain the changed network time synchronization error budget according to the UPF network element, (R) AN network element, clock precision, clock type and the like corresponding to the current PDU session.

In mode 2, the smf network element may determine a network time synchronization error budget of the PDU session according to network topology information corresponding to the PDU session and/or clock type and/or clock accuracy of the UPF network element and/or the (R) AN network element corresponding to the PDU session. The network topology information may include information of each node and AN adjacency relationship between the nodes on a first path, where the first path is a path between a UPF network element and a (R) AN network element.

Alternatively, the SMF network element may obtain network topology information from operation, administration and maintenance (Operation Administration and Maintenance, OAM) OAM or TSN centralized network configuration (Centralized Network Configuration, CNC), such as CNC in a transport network.

Referring to fig. 8, taking an example that the SMF network element obtains network topology information from OAM, the method includes the following procedures:

s801, AN SMF network element sends a first request to AN OAM, the OAM receives the first request, and the first request at least comprises AN identifier (R) AN network element (abbreviated as (R) AN identifier) corresponding to a PDU session and a UPF network element (abbreviated as UPF identifier);

s802, OAM sends a first response, the SMF network element receives the first response, and the first response comprises network topology information corresponding to PDU session.

For example, the SMF network element sends a first request to the OAM, where the first request carries the (R) AN identifier and the UPF identifier. After the OAM receives the first request, the information of each node on the first path and the adjacent relation between the nodes are determined according to the identification of the PCF network element and the identification of the UPF network element, and the information is carried in the first response as network topology information and returned to the SMF network element. After the SMF network element receives the first response, the network time synchronization error budget of the PDU session may be determined according to the network topology information corresponding to the PDU session, for example, the SMF network element may perform a test by transmitting a clock packet on the first path, to obtain the network time synchronization error budget of the PDU session.

For example, the SMF network element sends a first request to the OAM, where the first request may include, in addition to the (R) AN identifier and the UPF identifier corresponding to the PDU session, one or more of a clock type and/or clock precision of the UPF network element and/or the (R) AN network element corresponding to the PDU session, AN identifier (e.g., DNN) of a data network corresponding to the PDU session, AN identifier (e.g., S-nsai) of a network slice corresponding to the PDU session, application information (e.g., policy and charging control (Policy and Charging Control, PCC) rule ID or application description information) corresponding to the PDU session, and so on. After the OAM receives the first request, the OAM may determine a time synchronization error budget of each node and/or a transmission time synchronization error budget between nodes on the first path according to the information in the first request, so that when the OAM returns network topology information, the OAM returns, in addition to the information of each node and an adjacency relationship between nodes on the first path, the time synchronization error budget of each node and/or the transmission time synchronization error budget between nodes on the first path, and the SMF network element may accumulate the time synchronization error budget of each node and/or the transmission time synchronization error budget between nodes on the first path to obtain a network time synchronization error budget of the PDU session, or the OAM may determine the network time synchronization error budget of the PDU session according to the information in the first request, and the network time synchronization error budget of the DU session is carried in the first response, and the SMF network element may directly obtain the network time synchronization error budget of the DU session from the first response.

It will be appreciated that both of the above methods are equally applicable to TSN CNC. In the case of acquiring network topology information from TSN CNC, the SMF network element needs to replace the (R) AN identification, UPF identification with identification information of a sender (Talker) or a receiver (list) in the TSN network, such as a port number (port number) or a port address (port address), etc. The CNC may determine a corresponding network topology based on a link layer discovery protocol (Link Layer Discovery Protocol, LLDP).

Further optionally, when the third information includes a changed network time synchronization error budget, the third information may further include at least one of: the identification of the data network to which the PDU session corresponds (e.g., DNN), the identification of the network slice to which the PDU session corresponds (e.g., S-nsai), and the application information to which the PDU session corresponds (e.g., policy and charging control (Policy and Charging Control, PCC) rule ID or application description information). In this way, after the receiving end (such as the PCF network element or the first network element (such as TSCTSF or TSN AF)) receives the third information, it can determine which data network or network slice or network time synchronization error budget of the PDU session applied is the network time synchronization error budget in the third information, and the scheme reliability can be improved.

Further optionally, when there are multiple changed network time synchronization error budgets (for example, when there are multiple PDU sessions in the same DNN, S-nsai), the SMF network element may report all or only one of the multiple changed network time synchronization error budgets. For example, the SMF may report only the minimum network time synchronization error budget required by a certain DNN+S-NSSAI.

In another possible design, the third information may include a calculation parameter for determining a changed network time synchronization error budget. By way of example, the third information may include one or more of the following:

1) Identification of UPF network element and/or identification of (R) AN network element corresponding to PDU session;

2) Clock types of UPF network elements and/or (R) AN network elements corresponding to PDU session;

3) The clock type and/or clock accuracy of the UPF network element and/or the (R) AN network element corresponding to the PDU session.

Of course, the above three are merely examples and are not limiting.

Optionally, the third information may further include network topology information corresponding to the PDU session. In this way, the first network element may omit the process of acquiring network topology information.

Optionally, the third information may further include one or more of: the identification of the data network corresponding to the PDU session, the identification of the network slice corresponding to the PDU session, and the application information corresponding to the PDU session. In this way, the first network element may determine that the calculation parameter in the first information is a parameter for calculating which data network or network slice or network time synchronization error budget of the applied PDU session, which may improve the scheme reliability.

Optionally, the third information may further include an identifier of a preset event, where the identifier of the preset event is used to indicate the preset event, so that the network element (such as the PCF network element or the first network element) that receives the third information may determine that the preset event has occurred according to the identifier. Alternatively, the third information may not include an identifier of the preset event, but may carry a changed value (for example, a changed network time synchronization error budget, or a calculation parameter used to determine the changed network time synchronization error budget, etc.), and after receiving the third information, a network element (for example, a PCF network element or the first network element) that receives the third information may determine that the preset event has occurred according to the changed value.

S703, PCF sends first information, and the first network element receives the first information.

The first network element may be a TSCTSF network element or a TSN AF network element or other network elements needing to determine a network time synchronization error budget, which is not limited in this application.

In one possible design, the first information and the third information are the same, i.e. after the PCF network element receives the third information, the PCF network element does not process the third information, and directly sends the third information to the first network element. For example, the SMF network element may send the third information directly to the first network element via a container, and the PCF network element simply transparently passes the container.

For example, the first information and the third information each include a changed network time synchronization error budget. Optionally, each of the first information and the third information may further include at least one of DNN corresponding to the PDU session, S-nsai corresponding to the PDU session, application information corresponding to the PDU session, and the like. Optionally, the first information and the third information each further include an identifier of a preset event.

For example, each of the first information and the third information may include a calculation parameter for determining a changed network time synchronization error budget, such as one or more of AN identification of a UPF network element and/or AN identification of AN (R) AN network element corresponding to the PDU session, a clock type of a UPF network element and/or AN (R) AN network element corresponding to the PDU session, a clock type and/or a clock precision of a UPF network element and/or AN (R) AN network element corresponding to the PDU session, and the like. Optionally, each of the first information and the third information further includes one or more of network topology information corresponding to the PDU session, an identifier of a data network corresponding to the PDU session, an identifier of a network slice corresponding to the PDU session, application information corresponding to the PDU session, and the like. Optionally, the first information and the third information each further include an identifier of a preset event.

In another possible design, the first information and the third information may also be different. After receiving the third information, the PCF network element determines the first information according to the third information, and then sends the first information to the first network element.

The third information may include, for example, a calculation parameter for determining a changed network time synchronization error budget. The first information includes a changed network time synchronization error budget. In other words, the PCF may determine the changed network time synchronization error budget according to the calculation parameters reported by the SMF network element, and then report the changed network time synchronization error budget to the first network element.

Optionally, the first information and/or the third information further include an identification of a preset event.

In this case, the PCF network element may determine the specific implementation of the changed network time synchronization error budget, and may refer to the above specific implementation of the network time synchronization error budget determined by the SMF network element (e.g., the SMF network element determines the network time synchronization error budget of the PDU session according to the network topology information corresponding to the PDU session and/or the clock type and/or clock accuracy of the UPF network element and/or the (R) AN network element corresponding to the PDU session, or the SMF network element sends the third information to the OAM, the OAM feeds back the changed network time synchronization error budget, etc.), which will not be described herein.

It may be appreciated that when the PCF network element needs to determine the network time synchronization error budget according to the network topology information corresponding to the PDU session, if the third information includes the network topology information of the PDU session, the PCF network element may determine the network time synchronization error budget according to the network topology information in the third information. If the third information has no network topology information, the PCF network element may also acquire the network topology information from the OAM or TSN CNC, and the manner in which the PCF network element acquires the network topology information may refer to the manner in which the SMF network element acquires the network topology information above, which is not described herein.

S704, the first network element determines a network time synchronization error budget of the PDU session according to the first information; and determining the air interface time synchronization error budget of the PDU session according to the network time synchronization error budget.

According to the above, if the first information includes the changed network time synchronization error budget, the first network element may directly obtain the changed network time synchronization error budget.

If the first information carries a calculation parameter for determining the changed network time synchronization error budget, the first network element also needs to determine the changed network time synchronization error budget according to the calculation parameter carried in the first information. In this case, the specific implementation manner of the first network element in determining the changed network time synchronization error budget may refer to the specific implementation manner of the first network element in determining the changed network time synchronization error budget (for example, the first network element determines the network time synchronization error budget of the PDU session according to the network topology information corresponding to the PDU session and/or the clock type and/or clock precision of the UPF network element and/or the (R) AN network element corresponding to the PDU session, or the first network element sends the first information to the OAM, the OAM feeds back the changed network time synchronization error budget, etc.), which is not expanded herein.

It may be appreciated that, when the first network element needs to determine the network time synchronization error budget according to the network topology information corresponding to the PDU session, if the first information includes the network topology information of the PDU session, the first network element may determine the network time synchronization error budget according to the network topology information in the first information. If the first information has no network topology information, the first network element may also acquire the network topology information from the OAM or TSN CNC, and the manner in which the first network element acquires the network topology information may refer to the manner in which the SMF network element acquires the network topology information above, which is not described herein.

The first network element obtains the changed network time synchronization error budget, and then the air interface time synchronization error budget can be determined according to the changed network time synchronization error budget. For example, the first network element knows the 5GS time synchronization error budget and the device time synchronization error budget, and then uses the 5GS time synchronization error budget, the device time synchronization error budget, and the CN time synchronization error budget to obtain the Uu time synchronization error budget.

In the above steps S701 to S704, when the preset event occurs, the SMF network element may report the third information, so that the first network element may obtain the network time synchronization error budget, further determine the accurate Uu time synchronization error budget, and provide the terminal device with accurate access layer time. The scheme can improve the instantaneity of the time synchronization error budget acquired by the first network element and can improve the reliability of network transmission.

In one possible design, the first network element may subscribe to the SMF network element and/or the PCF network element for the purpose of enabling the SMF network element to report the third information in time when the preset event occurs, and for enabling the PCF network element to report the first information in time.

Referring to fig. 9, a flowchart of another information transmission method provided in an embodiment of the present application includes:

s901, a UE initiates a PDU session establishment flow, wherein the step is an optional step;

s902, an AF network element sends a clock synchronization requirement for PDU session, and a first network element receives the clock synchronization requirement;

the clock synchronization requirement may be that the AF network element requests to affect the 5G access layer time distribution (AF request to influence the, 5, G access stratum time distribution), or that the PTP instance in the TSCTSF activates, modifies or deactivates the trigger (triggered by PTP instance activation, modification, or deactivation in the TSCTSF).

S903, the first network element sends second information, the PCF network element receives the second information, and the second information is used for configuring the PCF network element or the SMF network element to report the first information;

optionally, the second information includes an identification of a preset event. The identification of the preset event is used for indicating the preset event. Optionally, the second information may also include one or more of PDU session identification, DNN, S-NSSAI, application identification, etc.

S904, the PCF network element sends fourth information to the SMF network element according to the second information, the SMF network element receives the fourth information, and the fourth information is used for configuring the SMF network element to report the third information;

it will be appreciated that the second information and the fourth information may be the same or different. For example, in the case that the second information and the fourth information are the same, the second information may also be understood as being used to configure the SMF network element to report the third information.

Optionally, the fourth information includes an identification of a preset event. The identification of the preset event is used for indicating the preset event. Optionally, the fourth information may also include one or more of PDU session identification, DNN, S-NSSAI, application identification, etc.

It will be appreciated that the fourth information may be the same as or different from the second information.

In a possible implementation manner, the second information is used for subscribing the network time synchronization error budget to the PCF network element, and the fourth information is used for subscribing the network time synchronization error budget to the SMF network element, so that the SMF network element reports an event that the network time synchronization error budget changes after the network time synchronization error budget changes. Optionally, the SMF network element may also report the changed network time synchronization error budget.

As one possible example, the PCF network element may set a policy control request trigger (Policy control request trigger) on the SMF to implement this function, e.g., the fourth information is used to set a policy control request trigger on the SMF network element, which is used to implement the function of the SMF reporting the third information. The trigger has the function of enabling the SMF network element to report the change event to the PCF network element when the network time synchronization error budget changes. In addition, the PCF can report the changed network time synchronization error budget to the PCF network element.

As another possible example, the PCF network element may carry fourth information in the PCC rule, where the fourth information is used to indicate that the service corresponding to the SMF network element (or the PCC rule) needs to report an event that the network time synchronization error budget changes and the changed network time synchronization error budget.

As another possible example, the first network element may subscribe to the event that the network time synchronization error budget changes directly to the SMF through a container, and the PCF network element simply transmits the container, where the container carries second information (also fourth information), and the second information indicates that the SMF network element reports the change event and the changed network time synchronization error budget when the network time synchronization error budget changes.

In another possible implementation manner, the second information is used to subscribe to the network time synchronization error budget with the PCF network element, and the fourth information is used to subscribe to a calculation parameter of the network time synchronization error budget with the SMF network element, where the calculation parameter is: the identification of the UPF network element and/or the identification of the (R) AN network element corresponding to the PDU session, the clock type of the UPF network element and/or the (R) AN network element corresponding to the PDU session, the clock type and/or the clock precision of the UPF network element and/or the (R) AN network element corresponding to the PDU session, and so on. When any calculation parameter changes, the SMF reports the event of the change of the calculation parameter to the PCF network element, and in addition, the PCF network element can also report the changed calculation parameter at the same time, so that the PCF network element can determine that the network time synchronization error budget changes according to the event of the change of the calculation parameter, and determine the changed network time synchronization error budget according to the changed calculation parameter, and further report the event of the change of the network time synchronization error budget and the changed network time synchronization error budget to the first network element.

As one possible example, the PCF network element may set a policy control request trigger (Policy control request trigger) on the SMF to implement this function. For example, the fourth information is used to set a policy control request trigger on the SMF network element, where the trigger is used to implement a function of reporting the third information by the SMF. The trigger has the function of enabling the SMF network element to report a change event and a changed value to the PCF network element when the identification of the UPF network element and/or the identification of the (R) AN network element corresponding to the PDU session, the clock type of the UPF network element and/or the (R) AN network element corresponding to the PDU session, or the clock type and/or the clock precision of the UPF network element and/or the (R) AN network element corresponding to the PDU session is changed.

As another possible example, the PCF network element may carry fourth information in the PCC rule, where the fourth information is used to indicate that the service corresponding to the SMF network element (or the PCC rule) needs to report the identifier of the UPF network element and/or the identifier of the (R) AN network element corresponding to the PDU session, the clock type of the UPF network element and/or the (R) AN network element corresponding to the PDU session, or AN event that the clock type and/or the clock precision level of the UPF network element and/or the (R) AN network element corresponding to the PDU session changes, and the changed value.

S905, after the preset event occurs, the SMF network element sends third information according to the fourth information, and the PCF network element receives the third information (i.e. the step S702 above);

s906, after receiving the third information, the PCF network element sends the first information according to the second information and the third information; the first network element receives the first information (i.e. step S703 above).

Through the above S901 to S906, when the SMF network element and the PCF network element occur at a preset event, the third information and the first information can be actively and timely reported, and the instantaneity of the first network element for acquiring the time synchronization error budget can be further improved.

In the above, the scenario is described in terms of standing on the whole of the PCF network element. In practical applications, PCF network elements may be further subdivided into AM-PCF network elements and SM-PCF network elements. Where the AM-PCF is PCF (PCF for a UE) responsible for serving the UE and the SM-PCF is PCF (PCF for a PDU Session) for PDU session.

Referring to fig. 10, a flowchart of another information transmission method provided in an embodiment of the present application includes:

s1001, the (optional) UE initiates a PDU session establishment procedure;

s1002, a first network element sends second information to an AM-PCF network element, and the AM-PCF network element receives the second information;

s1003, the AM-PCF network element further transmits fifth information to the SM-PCF network element, and the SM-PCF network element receives the fifth information;

The fifth information and the second information may be the same or different, and are not limited.

When the fifth information is identical to the second information, the fifth information may be referred to the description of the second information above, and is not expanded here.

When the fifth information and the second information are different, there are various cases, one of which is exemplified here: the event identifier contained in the fifth information is an identifier that the AM-PCF network element can subscribe to an event with the SM-PCF network element, and the event identifier contained in the second information is an event identifier that the first network element subscribes to the AM-PCF network element, and the two identifiers are different.

The event identifier included in the fifth information is, for example, an identifier of an event of a change of the network time synchronization error budget, that is, the fifth information is used to instruct the SM-PCF network element to report the event of the change of the network time synchronization error budget to the AM-PCF network element when the network time synchronization error budget is changed (and the changed value may also be reported to the AM-PCF network element together).

S1004, the SM-PCF network element sends fourth information to the SMF network element, and the SMF network element receives the fourth information;

s1005, after a preset event occurs, reporting third information to the SM-PCF network element by the SMF network element, and receiving the third information by the SM-PCF network element;

step S1005 may refer to the interaction procedure between the SMF network element and the PCF network element, which is not described herein.

S1006, the SM-PCF network element reports sixth information to the AM-PCF network element, and the AM-PCF network element receives the sixth information.

The sixth information and the third information may be the same or different, and are not limited.

When the sixth information is identical to the third information, the sixth information may be referred to the description of the third information above, and is not expanded here.

When the sixth information and the third information are different, there are various cases, two of which are exemplified here: for example, the event identifier included in the sixth information is an identifier that the AM-PCF subscribes to the SM-PCF, and the event identifier included in the third information is an event identifier that the SM-PCF network element subscribes to the SMF network element, where the two identifiers are different; for example, the sixth information includes a changed network time synchronization error budget, and the third information includes a calculation parameter for determining the changed network time synchronization error budget.

Optionally, the sixth information may include an identifier of a preset event, where the identifier of the preset event is used to indicate the preset event, so that the network element (such as an AM-PCF) that receives the sixth information may determine that the preset event has occurred according to the identifier. Alternatively, the sixth information may not include an identifier of the preset event, but may carry a changed value (for example, a changed network time synchronization error budget, or a calculation parameter used to determine the changed network time synchronization error budget, etc.), and after receiving the sixth information, the network element (for example, an AM-PCF network element) may determine that the preset event has occurred according to the changed value.

And S1007, the AM-PCF network element reports the first information to the first network element.

As another implementation manner, S1003 to S1004 may be replaced by: the AM-PCF network element sends fourth information to the SMF via the AMF. Accordingly, S1005 may be replaced by: after the preset event occurs, the SMF network element reports third information to the AM-PCF network element through the AMF. The AM-PCF network element may perceive the changed network time synchronization error budget according to the third information, and the manner in which the AM-PCF network element perceives the changed network time synchronization error budget may refer to the manner in which the SMF, the PCF, the first network element, etc. perceives the changed network time synchronization error budget, for example: the AMF network element reports relevant parameters or information (such as the identification of the UPF network element and/or the (R) AN network element, the clock type (or degradation notice) of the UPF network element or the (R) AN network element, and the like) which cause the change of the network time synchronization error budget to the AM-PCF network element, and the AM-PCF network element calculates the changed network time synchronization error budget. The reporting manner of the AMF to the AM-PCF network element may refer to the reporting manner of the SMF network element to the SM-PCF network element in the foregoing embodiment, which is not described herein. Correspondingly, the SMF network element shall report the related information to the AMF so that the AMF network element may obtain the information, and the specific reporting manner may refer to the embodiment in which the SMF network element reports the corresponding information to the PCF network element, which is not described herein.

By the scheme, under the condition that the PCF network element serving the UE and the PCF network element serving the PDU session are separated in different network elements, the TSCTSF can only generate correct air interface time synchronization error budget with the PCF network element serving the UE, and the flexibility of the scheme is improved.

It can be understood that if the AM-PCF network element issues the air interface time synchronization error budget finally, the AM-PCF network element can also sense the changed network time synchronization error budget, and the AM-PCF network element corrects the air interface time synchronization error budget according to the sensed network time synchronization error budget. Therefore, the AM-PCF network element does not need to report information to the first network element (such as TSCTSF) and does not need to calculate the air interface time synchronization error budget and then send the error budget to the AM-PCF network element, so that information transmission can be reduced, and system resources can be saved.

It is understood that the embodiments herein may be implemented separately or in combination with each other.

Based on the same technical concept, the embodiments of the present application provide a communication device 1100, where the communication device 1100 includes a module or a unit or means for performing the method performed by any network element in the method embodiments described above. The module or unit or means may be implemented by software, or by hardware executing corresponding software.

For example, referring to fig. 11, a communication device 1100 may include: a transceiver module 1101 and a processing module 1102.

When the apparatus is configured to implement the method performed by the first network element in the above method embodiment, the transceiver module 1101 is configured to receive the first information; a processing module 1102, configured to determine a network time synchronization error budget for the PDU session according to the first information; and determining the air interface time synchronization error budget of the PDU session according to the network time synchronization error budget.

When the apparatus is configured to implement the method performed by the PCF network element in the method embodiment, the transceiver module 1101 is configured to receive third information from the SMF network element; the transceiver module 1101 is further configured to send first information to the first network element, where the first information is third information or the first information is determined according to the third information, and the first information is used to determine a network time synchronization error budget of the PDU session.

When the apparatus is configured to implement a method performed by the SMF network element in the foregoing method embodiment, a processing module 1102 is configured to determine that a preset event occurs; the transceiver module 1101 is configured to send third information, where the third information is first information or the third information is used to determine the first information, and the first information is used to determine a network time synchronization error budget of the PDU session.

It should be understood that all relevant contents of each step involved in the above method embodiments may be cited to the functional descriptions of the corresponding functional modules, and are not described herein.

Based on the same technical concept, referring to fig. 12, the present embodiment further provides a communication apparatus 1200, including at least one processor 1201 and an interface circuit 1202; the interface circuit 1202 is configured to receive signals from other devices than the device and transmit the signals to the processor 1201 or send signals from the processor 1201 to other devices than the device, where the processor 1201 is configured to implement, by logic circuitry or executing code instructions, a method performed by any of the network elements of the method embodiments described above.

Optionally, the apparatus may further include a memory, where the memory may store instructions or programs for execution by the processing circuitry 1202 and may store data needed during some processing.

Alternatively, the memory may be integral to the processor 1201 or may be provided separately.

It should be understood that the processors mentioned in the embodiments of the present application may be implemented by hardware or may be implemented by software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, or the like. When implemented in software, the processor may be a general purpose processor, implemented by reading software code stored in a memory.

By way of example, the processor may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should be understood that the memories mentioned in the embodiments of the present application may be volatile memories or nonvolatile memories, or may include both volatile and nonvolatile memories. The nonvolatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable EPROM (EEPROM), or a flash Memory. The volatile memory may be random access memory (Random Access Memory, RAM) which acts as an external cache. By way of example, and not limitation, many forms of RAM are available, such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double Data rate Synchronous DRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), and Direct RAM (DR RAM).

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

It should be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

Based on the same technical concept, the embodiments of the present application also provide a computer readable storage medium, including a program or an instruction, which when run on a computer, causes a method performed by any one of the network elements as in the method embodiments described above to be performed.

Based on the same technical idea, the embodiments of the present application also provide a computer program product comprising instructions stored in the computer program product, which when run on a computer, cause a method performed by any one of the network elements as described in the method embodiments to be performed.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the spirit or scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims and the equivalents thereof, the present application is intended to cover such modifications and variations.

Claims

1. An information transmission method, comprising:

the first network element receives first information;

the first network element determines a network time synchronization error budget of a packet data unit PDU session according to the first information;

and the first network element determines the air interface time synchronization error budget of the PDU session according to the network time synchronization error budget.

2. The method of claim 1, wherein the first information comprises the network time synchronization error budget.

3. The method of claim 2, wherein the first information further comprises one or more of: the identification of the data network corresponding to the PDU session, the identification of the network slice corresponding to the PDU session, and the application information corresponding to the PDU session.

4. The method of claim 1, wherein the first information comprises one or more of:

the identification of the user plane function network element and/or the identification of the access network element corresponding to the PDU session;

and the clock type and/or the clock precision of the user plane function network element and/or the access network element corresponding to the PDU session.

5. The method of claim 4, wherein the first information further comprises one or more of: the identification of the data network corresponding to the PDU session, the identification of the network slice corresponding to the PDU session, and the application information corresponding to the PDU session.

6. The method according to claim 4 or 5, wherein the first network element determining a network time synchronization error budget for a PDU session from the first information comprises:

the first network element determines the network time synchronization error budget of the PDU session according to the network topology information corresponding to the PDU session and/or the clock type and/or clock precision of the user plane function network element and/or the access network element corresponding to the PDU session;

The network topology information comprises information of each node and an adjacent relation between the nodes on a first path, wherein the first path is a path between the user plane function network element and the access network element.

7. The method of claim 6, wherein the network topology information further comprises: and the time synchronization error budget of each node and/or the transmission time synchronization error budget among the nodes on the first path.

8. The method of claim 6 or 7, wherein,

the first information also comprises network topology information corresponding to the PDU session; or,

and the first network element acquires network topology information corresponding to the PDU session from operation, administration and maintenance (OAM) or Centralized Network Configuration (CNC) according to the first information.

9. The method according to claim 4 or 5, wherein the first network element determining a network time synchronization error budget for a PDU session from the first information comprises:

the first network element sends a first request to an operation, administration and maintenance (OAM) or a Centralized Network Configuration (CNC), wherein the first request comprises the first information;

The first network element receives a first response from the OAM or CNC, wherein the first response comprises the network time synchronization error budget of the PDU session.

10. The method of any one of claims 1-9, wherein the method further comprises:

the first network element sends second information to a PCF network element or a SMF network element of a policy control function, wherein the second information is used for configuring the PCF network element or the SMF network element to report the first information.

11. The method of claim 10, wherein the method further comprises: the second information comprises an identifier of a preset event.

12. The method of claim 11, wherein the preset event comprises one or more of:

the network topology information corresponding to the PDU session changes;

13. The method according to any of claims 1-12, wherein the first network element is a time delay sensitive communication, TSC, time synchronization function, TSF, network element or a time sensitive network, TSN, application function, AF, network element.

14. An information transmission method, comprising:

the PCF network element receives third information from the SMF network element;

the PCF network element sends first information to a first network element, wherein the first information is the third information or the first information is determined according to the third information, and the first information is used for determining network time synchronization error budget of a packet data unit PDU session.

15. The method of claim 14, wherein the first information comprises the network time synchronization error budget and the third information comprises the network time synchronization error budget.

16. The method of claim 14, wherein the first information comprises the network time synchronization error budget;

the third information includes one or more of:

17. The method of claim 14, wherein the first information and the third information each comprise one or more of:

18. The method of any one of claims 14-17, wherein the method further comprises:

the PCF network element receives second information from the first network element;

the PCF network element sends first information to a first network element, including:

the PCF network element sends the first information to the first network element according to the second information;

the time sensitive network TSN applies a function AF network element.

19. An information transmission method, comprising:

the SMF network element determines the occurrence of a preset event;

the SMF network element sends third information, where the third information is first information or the third information is used to determine first information, and the first information is used to determine a network time synchronization error budget of a packet data unit PDU session.

20. The method of claim 19, wherein the first information comprises the network time synchronization error budget and the third information comprises the network time synchronization error budget.

21. The method of claim 19, wherein the first information comprises the network time synchronization error budget;

the third information includes one or more of:

22. The method of claim 19, wherein the first information and the third information each comprise one or more of:

23. The method of any one of claims 19-22, wherein the method further comprises:

the SMF network element receives fourth information from the PCF network element;

the SMF network element sending third information, including:

and the SMF network element sends the third information to the PCF network element according to the fourth information.

24. The method of any one of claims 19-23, wherein the preset event comprises one or more of:

the network topology information corresponding to the PDU session changes;

25. A communication device, comprising:

a processing module for determining a network time synchronization error budget for a packet data unit, PDU, session based on the first information; and determining the air interface time synchronization error budget of the PDU session according to the network time synchronization error budget.

26. A communication device, comprising:

the transceiver module is further configured to send first information to a first network element, where the first information is the third information or the first information is determined according to the third information, and the first information is used to determine a network time synchronization error budget of a packet data unit PDU session.

27. A communication device, comprising:

the processing module is used for determining the occurrence of a preset event;

and the transceiver module is used for transmitting third information, wherein the third information is first information or is used for determining first information, and the first information is used for determining network time synchronization error budget of the packet data unit PDU session.

28. A communication device comprising a processor and interface circuitry for receiving signals from other communication devices than the communication device and transmitting to the processor or sending signals from the processor to other communication devices than the communication device, the processor being configured to implement the method of any one of claims 1 to 13, or to implement the method of any one of claims 14 to 18, or to implement the method of any one of claims 19 to 24, by logic circuitry or execution of code instructions.

29. A computer readable storage medium, characterized in that the storage medium has stored therein a computer program or instructions which, when executed by a communication device, implements the method of any one of claims 1 to 13, or implements the method of any one of claims 14 to 18, or implements the method of any one of claims 19 to 24.

30. A communication system, comprising: a first network element for performing the method of any one of claims 1 to 13;

PCF network element for performing the method of any one of claims 14 to 18;

an SMF network element for performing the method of any of claims 19 to 24.