Communication method and apparatus

Abstract

The present application provides a communication method and apparatus. The method comprises: a first network element receives a first message from a second network element, and then can send a second message to a third network element, the first message comprising a policy for a terminal device to access a local service, the second network element being used for managing a local user plane function network element, the second message being used for configuring a classification policy corresponding to the local service, and the classification policy being determined on the basis of the policy for the terminal device to access the local service. By using the second network element for performing in-domain user plane management and user policy management, direct management by a centralized control plane can be avoided, and thus when the deployment / activation / change of a user service is performed in-domain, the centralized control plane may not perceive the deployment / activation / change of a local service policy or a local service logic, so that the complexity in management of the centralized control plane can be effectively reduced.

Description

Communication method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on February 5, 2024, with application number 202410171399.3 and application name "A Communication Method and Device", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0004] The 3rd Generation Partnership Project (3GPP) defines edge computing as a way for operators and third-party services to be closer to the access point of terminal devices (such as user equipment (UE)), thereby improving service efficiency and reducing transmission latency. Edge computing can be used to select the nearest route within a subnet.

[0005] To start an edge application server, the terminal device needs to know the address (such as the Internet Protocol (IP) address) of the application server that provides the service. The terminal device can initiate the edge application server (EAS) discovery process to obtain the address of the appropriate EAS so that traffic can be locally routed to the edge application server.

[0006] Among them, 3GPP implements EAS discovery by defining the edge application server discovery function (EASDF) and using the domain name system (DNS). First, the terminal device initiates a DNS query request, which is sent to the EASDF network element through the user plane function (UPF) network element. After that, the EASDF network element sends the DNS query request to the corresponding DNS server based on the DNS message processing rules configured for it by the session management function (SMF) network element (SMF generates DNS message processing rules based on edge server deployment information), the fully qualified domain name (or fully qualified domain name, FQDN) of the DNS query, and the location of the terminal device. After the DNS server queries the optimal EAS address, it sends the optimal EAS address to the EASDF, which then sends the optimal EAS address to the SMF. Then, the SMF determines the local uplink diversion UPF (uplink classifier UPF, UL CL UPF) network element and the local protocol data unit (PDU) session anchor UPF (local PDU session anchor UPF, L-PSA UPF) network element to be inserted into the address corresponding to the optimal EAS based on the edge server deployment information (such as data network name (DNN), single network slice selection assistance information (S-NSSAI), application identifier, FQDN, DNS server information, address range information of the optimal EAS, etc.). Among them, the diversion capability of the UL CL UPF network element can be used to divert the edge traffic on the PDU session to the local EAS. After the local diversion user plane path is inserted, the EASDF network element can return the DNS query result to the terminal device so that the terminal device can achieve the optimal edge user plane path and thus perform edge computing services.

[0007] However, when a large number of applications are deployed at the edge, users' DNS requests will be processed centrally through SMF network elements and EASDF network elements. In this way, if the user's local policy is updated or modified, the centralized control plane will be updated, which will have a certain impact on the centralized control plane and greatly increase the management complexity of the centralized control plane. Summary of the Invention

[0008] The present application provides a communication method and apparatus for realizing that a centralized control plane can be unaware of the deployment / activation / change of local business policies or local business logic, thereby reducing the management complexity of the centralized control plane.

[0009] In a first aspect, the present application provides a communication method, which can be executed by a first network element or a module of the first network element (such as a processor, a processing unit, a chip, a chip system or a circuit, etc.). Optionally, the method can also be implemented by a logical node, a logical module or software that can implement all or part of the functions of the first network element. Exemplarily, the following takes the execution of the communication method by the first network element as an example. The method may include the following steps: the first network element may receive a first message from the second network element, and then the first network element may send a second message to the third network element, wherein the first message includes a policy for the terminal device to access local services, the second network element is used to manage the local user plane function network element, and the second message is used to configure the diversion policy corresponding to the local service, and the diversion policy is determined according to the policy for the terminal device to access the local service.

[0010] In this method, the user plane management and user policy management within the domain (or can be called local) are performed by the second network element, which can avoid direct management of the centralized control plane. Therefore, when the user service (which can be understood as local service) is deployed / activated / changed within the domain, the centralized control plane can be unaware of the deployment / activation / change of the local service policy or local service logic, thereby effectively alleviating (or reducing) the management complexity of the centralized control plane.

[0011] Accordingly, in a second aspect, the present application provides a communication method, which can be performed by a second network element or a module of the second network element (such as a processor, a processing unit, a chip, a chip system or a circuit, etc.). Optionally, the method can also be implemented by a logical node, a logical module or software that can implement all or part of the functions of the second network element. Exemplarily, the following takes the execution of the communication method by the second network element as an example. The method may include the following steps: the second network element sends a first message to the first network element, wherein the first message includes a policy for the terminal device to access local services, and the second network element is used to manage the local user plane function network element.

[0012] The technical effects that can be achieved in the second aspect can be referred to the technical effects that can be achieved in the first aspect mentioned above, and will not be repeated here.

[0013] Accordingly, in a third aspect, the present application provides a communication method, which can be executed by a third network element or a module of the third network element (such as a processor, a processing unit, a chip, a chip system or a circuit, etc.). Optionally, the method can also be implemented by a logical node, a logical module or software that can implement all or part of the functions of the third network element. Exemplarily, the following takes the execution of the communication method by the third network element as an example. The method may include the following steps: the third network element receives a second message from the first network element, wherein the second message is used to configure a diversion strategy for the terminal device to access local services.

[0014] The technical effects that can be achieved in the third aspect can be referred to the technical effects that can be achieved in the first aspect mentioned above, and will not be repeated here.

[0015] In a possible implementation method provided in the first aspect, when the policy for the terminal device to access the local service includes a diversion policy corresponding to the local service, the second message may include the diversion policy corresponding to the local service; or when the policy for the terminal device to access the local service does not include a diversion policy corresponding to the local service, the first network element may create a diversion policy corresponding to the local service based on the policy for the terminal device to access the local service.

[0016] In the above implementation, the method for determining the diversion strategy is relatively flexible and can meet the needs in different situations.

[0017] In a possible implementation of the first or second aspect, before receiving the first message from the second network element, the method further includes: the first network element receiving session information of a terminal device from a fourth network element; thereafter, the first network element may send a third message to the second network element based on information about the second network element included in the session information of the terminal device, wherein the third message is used to obtain (or request) a policy for the terminal device to access local services. Accordingly, after receiving the third message, the second network element may send the first message to the first network element based on the third message.

[0018] In the above implementation, the first network element establishes a communication connection with the second network element based on the second network element's information, and after the communication connection is established, requests the second network element for a policy for terminal device access to local services. The second network element is responsible for intra-domain (or local) user plane management and user policy management.

[0019] In a possible implementation manner provided by the first aspect, before receiving the session information of the terminal device from the fourth network element, the method further includes: the first network element sends a first subscription message to the fourth network element, wherein the first subscription message is used to subscribe to the session information of the terminal device.

[0020] In the above implementation method, after the first network element subscribes to the relevant session information of the terminal device (such as the information of the second network element (such as the identifier)) to the fourth network element, the fourth network element can make a session creation request when the terminal device is online, or the registration information of the second network element in the fourth network element (such as the identifier information of the second network element) is updated, or when the second network element used to provide corresponding services for the terminal device is newly registered in the fourth network element, the relevant session information of the terminal device is sent to the first network element. This enables the first network element to obtain the relevant session information of the terminal device in a timely manner, thereby facilitating the first network element to establish a communication connection with the second network element in a timely and accurate manner based on the information of the second network element.

[0021] In a possible implementation provided in the first aspect, the method also includes: if the policy for the terminal device to access local services does not include the addressing policy corresponding to the local services, and the session of the terminal device does not select the fifth network element, the first network element may select the fifth network element for the session of the terminal device, and then the first network element may send a fourth message to the fifth network element, and then the first network element may send the address information of the fifth network element to the terminal device, wherein the fourth message is used to configure the addressing policy corresponding to the local service, the addressing policy is generated according to the policy for the terminal device to access the local service, and the address information is used for the terminal device to perform subsequent domain name queries.

[0022] In the above implementation, the first network element selects the fifth network element based on the relevant information provided by the second network element (such as the fifth network element list, information about the second network element (such as the service scope of the second network element), the data network name, the single network slice selection auxiliary information, the data network access identifier, or the location of the terminal device), and configures the addressing policy, DNS processing policy, etc. for the fifth network element, so that the fifth network element can provide corresponding services for the session of the terminal device in a timely and effective manner. It can be understood that the addressing policy configured for the fifth network element is created based on the policy for the terminal device to access the local service from the second network element.

[0023] In a possible implementation provided in the first aspect, the method further includes: the first network element receives a fifth message from a fifth network element, wherein the fifth message may include address information of the first application server, and the address information of the first application server is obtained based on a domain name query initiated by the terminal device. Thereafter, the first network element can determine the third network element based on the fifth message.

[0024] In the above implementation method, when the strategy for the terminal device to access local services does not include the addressing strategy corresponding to the local services, or the strategy for the terminal device to access local services does not include the diversion strategy corresponding to the local services, the first network element can trigger the selection of the third network element based on the fifth message from the fifth network element, thereby achieving effective selection of the third network element.

[0025] In a possible implementation manner provided by the first aspect, the method further includes: if the policy for the terminal device to access the local service includes a diversion policy corresponding to the local service, the first network element can determine the third network element in a timely and effective manner according to the diversion policy.

[0026] In a possible implementation manner provided in the first aspect, the method also includes: the first network element sends first information to the second network element, after which the first network element can receive second information from the second network element, and then the first network element can send third information to the third network element, wherein the first information is used to request allocation of an uplink tunnel identifier of a sixth network element, the first information may include a downlink tunnel identifier of the third network element, the sixth network element is a local user plane function network element, the second information may include an uplink tunnel identifier of the sixth network element, the third information may include an uplink tunnel identifier of the sixth network element, and the downlink tunnel identifier of the third network element and the uplink tunnel identifier of the sixth network element can be used to establish a first user plane tunnel corresponding to the local service between the third network element and the sixth network element.

[0027] Accordingly, in a possible implementation manner provided by the second aspect, the method also includes: the second network element receives the first information from the first network element and can send the sixth information to the sixth network element. After that, the second network element can receive the seventh information from the sixth network element, and then, the second network element can send the second information to the first network element, wherein the first information can be used to request the allocation of the uplink tunnel identifier of the sixth network element, the first information may include the downlink tunnel identifier of the third network element, the sixth network element is a local user plane function network element, the sixth information can be used to request the allocation of the uplink tunnel identifier of the sixth network element, the sixth information may include the downlink tunnel identifier of the third network element, the seventh information may include the uplink tunnel identifier of the sixth network element, the second information may include the uplink tunnel identifier of the sixth network element, the downlink tunnel identifier of the third network element and the uplink tunnel identifier of the sixth network element can be used to establish the first user plane tunnel corresponding to the local service between the third network element and the sixth network element.

[0028] Accordingly, in a possible implementation provided in the third aspect, the method also includes: the third network element receives third information from the first network element, and the third information may include the uplink tunnel identifier of the sixth network element, wherein the uplink tunnel identifier of the sixth network element is used to establish a first user plane tunnel corresponding to the local service between the third network element and the sixth network element.

[0029] In the above implementation, because the second network element is responsible for user plane management within the domain (for example, management of the sixth network element), the second network element assists in establishing the user plane tunnel, making the establishment of the user plane tunnel more efficient. Furthermore, during the user plane tunnel establishment process, the centralized control plane does not need to directly manage the sixth network element, thereby reducing the management complexity of the centralized control plane.

[0030] In a possible implementation provided in the first aspect, the method also includes: the first network element can send fourth information to the third network element, and then the first network element can receive fifth information from the third network element. If the fifth information includes the updated uplink tunnel identifier of the third network element, the first network element can send the updated uplink tunnel identifier of the third network element to the access network device, wherein the fourth information may include the downlink tunnel identifier of the access network device, and the downlink tunnel identifier of the access network device and the updated uplink tunnel identifier of the third network element are used to establish a second user plane tunnel corresponding to the local service between the access network device and the third network element.

[0031] Accordingly, in a possible implementation provided in the third aspect, the method also includes: the third network element receives fourth information from the first network element, and then the third network element can send fifth information to the first network element, wherein the fourth information may include the downlink tunnel identifier of the access network device, and the fifth information may include the uplink tunnel identifier of the third network element or the updated uplink tunnel identifier of the third network element. The downlink tunnel identifier of the access network device and the uplink tunnel identifier of the third network element or the updated uplink tunnel identifier of the third network element can be used to establish a second user plane tunnel corresponding to the local service between the access network device and the third network element.

[0032] In the above implementation method, by providing the downlink tunnel identifier of the access network device to the third network element, the third network element can return the uplink tunnel identifier of the third network element, or if the uplink tunnel identifier of the third network element is updated, the updated uplink tunnel identifier of the third network element is returned. This can facilitate the access network device to establish a user plane tunnel corresponding to the local service with the third network element based on the uplink tunnel identifier of the third network element (or the updated uplink tunnel identifier), thereby facilitating timely and effective local service data transmission between the access network device and the third network element.

[0033] In a possible implementation provided in the second aspect, the method also includes: the second network element selects the fifth network element, after which the second network element can send a sixth message to the fifth network element, and then the second network element can send a seventh message to the first network element, wherein the sixth message can be used to configure the addressing strategy corresponding to the local service, the addressing strategy is included in the strategy for the terminal device to access the local service, the seventh message may include the identification information and / or address information of the fifth network element, and the identification information and / or address information of the fifth network element can be used to establish a communication connection between the first network element and the fifth network element.

[0034] In the above implementation, the second network element completes the selection of the fifth network element based on the relevant information corresponding to the session of the terminal device (such as the fifth network element list, information of the second network element (such as the service scope of the second network element), the data network name, the single network slice selection auxiliary information, the data network access identifier, or the location of the terminal device), and configures the addressing policy, DNS processing policy, etc. for the fifth network element, so that the fifth network element can provide corresponding services for the session of the terminal device in a timely and effective manner. In this way, this implementation method can help reduce the management complexity of the centralized control plane by having the second network element complete the corresponding configuration of the fifth network element.

[0035] In a possible implementation method provided in the second aspect, sending a first message to a first network element includes: the second network element sending a second subscription message to a fourth network element, after which the second network element receives session information of a terminal device from the fourth network element, and then, the second network element can send a first message to the first network element based on the information of the first network element, wherein the second subscription message is used to subscribe to the session information of the terminal device, and the session information of the terminal device includes information of the first network element used to provide services for the terminal device.

[0036] In the above implementation method, after the second network element subscribes to the relevant session information of the terminal device (such as the information of the first network element (such as the identifier)) to the fourth network element, the fourth network element can make a session creation request when the terminal device is online, or the registration information of the first network element in the fourth network element (such as the identifier information of the first network element) is updated, or when the first network element used to provide corresponding services for the terminal device is newly registered in the fourth network element, the relevant session information of the terminal device is sent to the second network element. This enables the second network element to obtain the relevant session information of the terminal device in a timely manner, thereby facilitating the second network element to establish a communication connection with the first network element in a timely and accurate manner based on the information of the first network element.

[0037] In a possible implementation provided in the second aspect, the method also includes: the second network element sends an eighth message to the fourth network element, wherein the eighth message may include information of the second network element and identification information of the terminal device, and the eighth message is used to trigger the establishment of a communication connection between the second network element and the first network element.

[0038] In the above implementation method, the second network element actively registers its own relevant information (such as the corresponding information included in the eighth message) to the fourth network element, which makes it convenient for the fourth network element to promptly send the relevant session information of the terminal device (such as the information of the second network element) to the first network element when the fourth network element stores the relevant information of itself registered by the second network element in the fourth network element or when the terminal device goes offline and comes back online to make a session creation request.

[0039] In a fourth aspect, the present application provides a communication device capable of implementing the method of any possible implementation of any of the first to third aspects above. The communication device can be implemented via hardware or by hardware executing corresponding software implementations. The hardware or software includes one or more units or modules corresponding to the above-mentioned functions.

[0040] In one possible implementation, the communication device includes a processor configured to support the communication device in executing the corresponding functions of the first network element, the second network element, the third network element, the fourth network element, the fifth network element, the sixth network element, the seventh network element, the eighth network element, the access network device, or the terminal device in the method described above. The communication device may also include a memory, which may be coupled to the processor and stores program instructions and data necessary for the communication device. Optionally, the communication device also includes a communication interface for supporting communication between the communication device and other devices.

[0041] In one possible implementation, the communication device includes corresponding functional modules, which are respectively used to implement the steps in the above method. The functions can be implemented by hardware, or the corresponding software can be implemented by hardware. The hardware or software includes one or more modules corresponding to the above functions. For example, the communication device includes corresponding means or modules for executing the methods of the first aspect, the second aspect or the third aspect. For example, the communication device includes a processing module (or can be called a processing unit) and / or a transceiver module (or can be called a communication unit, a communication module or a transceiver unit, for sending and receiving data). The transceiver module can implement the sending function and the receiving function. When the transceiver module implements the sending function, it can be called a sending unit (or can be called a sending module). When the transceiver module implements the receiving function, it can be called a receiving unit (or can be called a receiving module). The sending unit and the receiving unit can be the same functional unit, which is called a transceiver module, and the functional unit can implement the sending function and the receiving function; or, the sending unit and the receiving unit can be different functional units, and the transceiver module is a general term for these functional units. These modules (units) can perform the corresponding functions in the method examples of the first aspect, the second aspect or the third aspect mentioned above. For details, please refer to the detailed description in the method examples, which will not be repeated here.

[0042] In one possible embodiment, the structure of the communication device includes a transceiver module and a processing module, which can perform the corresponding functions in the above method example. For details, please refer to the description of the method in any possible implementation of any aspect from the first aspect to the third aspect, which will not be repeated here.

[0043] In a fifth aspect, the present application further provides a communication device, which includes a processor and a communication interface, wherein the communication interface is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor implements the method in any possible implementation of any aspect of the first to third aspects above through a logic circuit or by executing a computer program or instruction. Optionally, the communication device also includes a memory for storing computer programs or instructions.

[0044] In a sixth aspect, the present application provides a communication system, comprising multiple communication devices (e.g., multiple of a first network element, a second network element, a third network element, a fourth network element, a fifth network element, a sixth network element, a seventh network element, an eighth network element, an access network device, or a terminal device). The implementation of the relevant functions of the first network element, the second network element, the third network element, the fourth network element, the fifth network element, the sixth network element, the seventh network element, the eighth network element, the access network device, or the terminal device can refer to the relevant descriptions mentioned in the first aspect, the second aspect, or the third aspect above, and will not be repeated here.

[0045] In the seventh aspect, the present application provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are run on a computer, the computer executes the method in any possible implementation of any one of the first to third aspects above.

[0046] In an eighth aspect, the present application provides a computer-readable storage medium, which stores a computer program or instruction. When the computer program or instruction is executed by a computer, the computer executes a method in any possible implementation of any one of the first to third aspects above.

[0047] In a ninth aspect, the present application provides a chip, which may include a processor and a memory (or the chip is coupled to the memory), wherein the chip executes program instructions in the memory to perform the method in any possible implementation of any of the first to third aspects above. "Coupled" refers to the direct or indirect connection of two components to each other, such as electrical connection between two components.

[0048] In a tenth aspect, the present application further provides a chip system, which includes a processor for supporting a computer device to implement the method in any possible implementation of any of the first to third aspects above. In one possible implementation, the chip system also includes a memory for storing programs and data necessary for the computer device. The chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0049] Based on the implementation methods provided in the above aspects, this application can also be further combined to provide more implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG1a exemplarily shows a possible communication system architecture diagram provided by an embodiment of the present application;

[0051] FIG1b exemplarily shows another possible communication system architecture diagram provided by an embodiment of the present application;

[0052] FIG2 exemplarily shows a flow chart of a communication method provided in an embodiment of the present application;

[0053] FIG3 exemplarily shows a schematic diagram of a possible application scenario provided by an embodiment of the present application;

[0054] FIG4 exemplarily shows a flow chart of another communication method provided in an embodiment of the present application;

[0055] FIG5 exemplarily shows a flow chart of another communication method provided in an embodiment of the present application;

[0056] FIG6 exemplarily shows a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0057] FIG7 exemplarily shows a structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] Before introducing the technical solution provided by this application, some of the terms involved in this application are first explained to facilitate understanding by those skilled in the art.

[0059] (1) EAS: It is used to provide users with access to the network and can communicate with other server devices. Usually, edge application servers can be a group of servers that perform a single function, such as firewall servers, cache servers, load balancing servers, DNS servers, etc. For the Internet of Things, due to the continuous development of edge computing technology, many controls can be implemented by local devices without being handed over to the cloud. The processing process will be completed at the local edge computing layer, which will greatly improve processing efficiency and reduce the load on the cloud. Because it is closer to the user, it can also provide users with faster responses and solve their needs at the edge.

[0060] (2) Protocol Data Unit (PDU) Session: A logical connection between a terminal device and a data network (DN), which provides a user plane connection from the terminal device to the DN. PDU sessions include sessions between the terminal device and the access network device, between the access network device and the user plane function (UPF) network element, and between the UPF network element and the DN. A PDU session includes at least one Quality of Service (QoS) flow.

[0061] (3) Edge computing (EC): This refers to a distributed open platform (architecture) that integrates network, computing, storage, and application core capabilities at the edge of the network, close to the source of objects or data, to provide edge intelligent services nearby, meeting the key needs of industry digitalization in terms of agility, real-time business, data optimization, application intelligence, security and privacy protection, etc. It can serve as a bridge connecting the physical and digital worlds, enabling smart assets, smart gateways, smart systems, and smart services. Currently, edge computing encompasses three distinct paradigms: open edge computing (cloudlets), fog computing (of the openFog consortium), and mobile edge computing (MEC) to multi-access edge computing (MEC). Open edge computing can connect to the cloud via a limited internet connection. Its powerful computing capabilities enable it to efficiently process tasks from various mobile devices, while also being very close to them. Fog computing distributes computing, storage, networking, control, and decision-making resources and services to any location in the cloud and objects. It is primarily used to address business scenarios such as the Internet of Things (IoT), artificial intelligence (AI), virtual reality, and fifth-generation (5G) mobile communications technologies. From mobile edge computing to multi-access edge computing, applications can be run within wireless base stations to provide services to mobile users.

[0062] (4) Edge Hosting Environment (EHE): ​​The edge hosting environment (EHE) referred to in the embodiments of this application may refer to an environment that provides the necessary support for the execution of an edge application server (EAS). In an EC scenario, network applications or services may be deployed on an edge hosting environment (EHE), which may manage the applications or services.

[0063] It should be noted that, in the embodiments of the present application, "sending a message (or information)" can be understood as one device sending a message (or information) to another device, or it can also be understood as a logic module within a device sending a message (or information) to another logic module. For example, "a first network element sending a message" can be understood as the first network element sending a message to another device (such as a second network element), or it can be understood as logic module 1 in the first network element sending a message to logic module 2 in the second network element.

[0064] In the embodiments of the present application, "receiving a message (or information)" can be understood as a device receiving a message (or information) from another device, or it can also be understood as a logic module within a device receiving a message (or information) from another logic module. For example, "a first network element receiving a message" can be understood as the first network element receiving a message from another device (such as a second network element), or it can be understood as logic module 1 in the first network element receiving a message from logic module 2 in the second network element.

[0065] In the embodiment of the present application, "sending a message (or information) to the second network element" can be understood as the destination end of the message (or information) is the second network element. It can include sending a message (or information) to the second network element directly or indirectly. "Receiving a message (or information) from the second network element" can be understood as the source end of the message (or information) is the second network element, which can include receiving a message (or information) from the second network element directly or indirectly. The message (or information) may be subjected to necessary processing between the source end and the destination end of the message (or information), such as format changes, etc., but the destination end can understand the valid message from the source end. Similar expressions in the embodiments of the present application can be understood similarly and will not be repeated here.

[0066] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0067] The following describes the communication system architecture to which the communication method provided in this application is applicable. It should be noted that these descriptions are for the purpose of facilitating understanding by those skilled in the art and do not limit the scope of protection claimed in this application.

[0068] Figure 1a exemplarily shows a possible communication system architecture diagram applicable to an embodiment of the present application. Among them, the communication system architecture shown in Figure 1a is a 5G communication system architecture formulated by the 3rd Generation Partnership Project (3GPP) standard, and the communication system architecture includes terminal equipment (for example, user equipment (UE)), access network (AN) (for example, radio access network (RAN)), core network (CN) and data network. Optionally, the terminal device can be connected to the access network device (such as (R)AN device) in a wireless manner, and the access network device can be connected to the core network in a wireless or wired manner. The core network device and the radio access network device can be independent and different physical devices, or the functions of the core network device and the logical functions of the radio access network device can be integrated on the same physical device, or the functions of some core network devices and some radio access network devices can be integrated on one physical device. Terminal devices and terminal devices, and access network devices and access network devices can be connected to each other in a wired or wireless manner. Exemplarily, the communication system architecture may also include other network devices (such as wireless relay devices or wireless backhaul devices, etc.).

[0069] The following is a brief introduction to the functions of some devices included in the communication system architecture.

[0070] Terminal devices are user-side entities capable of transmitting and receiving signals, providing services such as video, voice, and data connectivity. For example, terminal devices are the gateway for mobile users to interact with the network, providing basic computing and storage capabilities, displaying service windows, and receiving user input. Next-generation terminal devices (NextGen UEs) utilize new air interface technologies to establish signal and data connections with access network equipment, transmitting control signals and service data to the mobile network.

[0071] Optionally, the terminal device may also be referred to as a terminal, user equipment (UE), access terminal equipment, vehicle-mounted terminal, industrial control terminal, UE unit, UE station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal equipment, mobile device, UE terminal equipment, terminal equipment, wireless communication equipment, UE agent or UE device, etc. In an embodiment of the present application, the terminal device may be fixed or mobile, and the implementation of the present application does not limit this. For example, the terminal device may be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted, or may be deployed on water (such as a ship, etc.), or may be deployed in the air (such as an airplane, a balloon or a satellite, etc.).

[0072] Exemplarily, the terminal device may be a mobile phone, a tablet computer, a subscriber unit, a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA) computer, a wireless modem, a handheld device, a laptop computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a vehicle-mounted terminal device, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a wearable terminal device, a vehicle, a drone, a helicopter, an airplane, factory machinery / equipment, a machine type communication (MTC) terminal, a ship or a robot, etc. For example, vehicles may include, but are not limited to, smart cars (or intelligent cars), digital cars, unmanned cars (or driverless cars or pilotless cars or automobiles), self-driving cars (or autonomous cars), pure electric vehicles (or battery EVs), hybrid electric vehicles (HEVs), range-extended EVs (REEVs), plug-in hybrid electric vehicles (PHEVs), or new energy vehicles, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device.

[0073] Access network equipment: This is the device that connects terminal devices to a wireless network. Access network equipment can also be referred to as access network devices, wireless access network equipment, (R)AN entities, network devices, access nodes, (R)AN nodes, or (R)AN devices. For example, access network equipment provides network access for authorized users in a specific area and can determine transmission tunnels of varying quality to transmit user data based on user levels and service requirements. Access network equipment manages its own resources, utilizing them effectively, providing access services to terminal devices on demand, and forwarding control signals and user data between terminal devices and the core network.

[0074] Exemplarily, the access network equipment may include, but is not limited to: a next generation NodeB (gNB) in a 5G communication system, a next generation base station in a sixth generation (6G) communication system, a base station in a future communication system, a transmission reception point (TRP), an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved Node B, or a home Node B, HNB), a base band unit (BBU), or a wireless fidelity (Wi-Fi) access point (AP), etc.

[0075] Optionally, in a network structure, the access network device may include a centralized unit (CU) or a distributed unit (DU). This structure can split the protocol layer of the access network device, with the functions of some protocol layers being centrally controlled by the CU, and the functions of the remaining part or all of the protocol layers being distributed in the DU, which is centrally controlled by the CU. For example, the functions of the packet data convergence protocol (PDCP) layer and above can be set in the CU, and the functions of the protocol layers below the PDCP (such as the RLC layer and the medium access control (MAC) layer, etc.) are set in the DU. It should be noted that this division of the protocol layers is only an example, and can also be divided in other protocol layers. The radio frequency device can be remote and not placed in the DU, or it can be integrated in the DU, or partly remote and partly integrated in the DU, and the embodiments of the present application do not impose any restrictions. In addition, in some embodiments, the control plane (CP) and user plane (UP) of the CU can be separated and implemented as different entities, namely the control plane CU entity (CU-CP entity) and the user plane CU entity (CU-UP entity).

[0076] For example, taking the access network device as a base station, the base station can communicate with the terminal device, or communicate with the terminal device through a relay station. The terminal device can communicate with multiple base stations using different access technologies.

[0077] In the embodiment of the present application, the access network device may be a macro base station, a micro base station, an indoor station, a relay node, a donor node, etc. The embodiment of the present application does not limit the specific technology and specific device form used by the wireless access network device.

[0078] Data network: A data network that provides business services to users. Typically, the client is located on a terminal device, and the server is located on the data network. A data network can be a private network, such as a local area network (LAN), an external network not controlled by the operator, such as the Internet, or a proprietary network jointly deployed by operators, such as the network that provides IP multimedia core network subsystem (IMS) services.

[0079] Core network: Responsible for maintaining mobile network subscription data, managing mobile network network elements, and providing terminal devices with session management, mobility management, policy management, security authentication, and other functions. When a terminal device is attached, it provides network access authentication for the terminal device; when the terminal device has a service request, it allocates network resources to the terminal device; when the terminal device moves, it updates network resources for the terminal device; when the terminal device is idle, it provides a fast recovery mechanism for the terminal device; when the terminal device is detached, it releases network resources for the terminal device; when the terminal device has service data, it provides data routing functions for the terminal device, such as forwarding uplink data to the data network; or receiving downlink data from the terminal device from the data network and forwarding it to the access network device, which then sends it to the terminal device. Optionally, in terms of functional logic, the core network elements can be divided into two parts: user plane network elements (or user plane function network elements or user plane functional entities) and control plane network elements. Among them, user plane network elements are responsible for the transmission of service data. For example, user plane network elements can include but are not limited to UPF network elements. The control plane network element is responsible for the management of the mobile network. For example, the control plane may include but is not limited to the access and mobility management function (AMF) network element (or entity), the session management function (SMF) network element, the unified data management (UDM) network element (or unified data repository (UDR) network element), the policy control function (PCF) network element, the AF network element, the authentication server function (AUSF) network element, and the network slice selection function (NSSF) network element. Of course, the core network may also include other network elements (such as the network exposure function (NEF) network element, the network storage function (NRF) network element, the network slice selection authentication and authorization function (NSSAAF) network element or the edge application server discovery function (EASDF) network element, etc.), which are not listed here one by one.

[0080] Optionally, the core network control plane adopts a service-based architecture, where interactions between control plane network elements use service invocations, replacing the traditional point-to-point communication. In a service-based architecture, control plane network elements expose services to other control plane network elements for invocation. In point-to-point communication, the communication interface between control plane network elements stores a set of specific messages that can only be used by the control plane network elements at both ends of the interface during communication.

[0081] The following is a brief introduction to the functions of some network elements included in the core network:

[0082] (1) SMF network element: mainly used for session management, IP address allocation and management of terminal devices, selection of endpoints for manageable user equipment plane functions, policy control, or charging function interfaces, and downlink data notification, etc. For example, it can complete processes such as establishment, release, and update of protocol data unit (PDU) sessions. In 5G communication systems, the session management network element can be an SMF network element. In future communications such as the sixth-generation (6G) communication system, the session management function network element can still be an SMF network element, or have other names, which is not limited in this application. Nsmf is a service-based interface provided by the SMF network element. The SMF network element can communicate with other network functions through Nsmf.

[0083] (2) AMF network element: Mainly used for mobility management and access management, etc. For example, it can receive non-access stratum (NAS) signaling of terminal devices (including mobility management (MM) signaling and session management (SM) signaling) and related signaling of access network devices (such as N2 signaling at the base station granularity that interacts with the AMF network element), complete the user registration process and forwarding of SM signaling and mobility management. For example, it can be the mobility management entity (MME) in the fourth-generation (6G) communication system or the AMF network element in the 5G communication system. In future communication systems such as 6G communication systems, the access management network element can still be the AMF network element, or have other names, which is not limited in this application. Namf is a service-based interface provided by the AMF network element. The AMF network element can communicate with other network functions through Namf.

[0084] (3) UDM network element: used to process user identification, contract signing, access authentication, registration, or mobility management. In 5G communication systems, the data management network element can be a UDM network element. In future communication systems such as 6G communication systems, the data management network element can still be a UDM network element or have other names, which are not limited in this application. Among them, Nudm is a service-based interface provided by the UDM network element. The UDM network element can communicate with other network functions through Nudm.

[0085] (4) PCF network element: a unified policy framework for guiding network behavior, providing policy rule information (such as mobility-related policies or PDU session-related policies (such as quality of service (QoS) policies, billing policies, etc.) or slice selection policies) for control plane functional network elements (such as AMF, SMF, etc.). In a 5G communication system, the policy control network element may be a PCF network element. In future communication systems such as a 6G communication system, the policy control network element may still be a PCF network element, or have other names, which is not limited in this application. Npcf is a service-based interface provided by the PCF network element, and the PCF network element can communicate with other network functions through Npcf.

[0086] (5) AF network element: used for data routing affected by applications, accessing network open functions, or interacting with the policy framework for policy control. In 5G communication systems, application network elements can be AF network elements. In future communication systems such as 6G communication systems, application network elements can still be AF network elements or have other names, which are not limited in this application. Naf is a service-based interface provided by AF. AF network elements can communicate with other network functions through Naf.

[0087] (6) UPF network element: used for packet routing and forwarding, or QoS processing of user plane data. In 5G communication systems, the user plane function network element can be a UPF network element. In future communication systems such as 6G communication systems, the user plane function network element can still be a UPF network element, or have other names. This application does not limit this.

[0088] (7) AUSF network element: Mainly used for user authentication, etc. In 5G communication systems, the authentication service network element can be an AUSF network element. In future communication systems such as 6G communication systems, the authentication service network element can still be an AUSF network element, or have other names, which are not limited in this application. Nausf is a service-based interface provided by the AUSF network element. The AUSF network element can communicate with other network functions through Nausf.

[0089] (8) NSSF network element: used to select network slices for terminal devices. In the 5G communication system, the network slice selection function network element may be the NSSF network element. In future communication systems such as the 6G communication system, the network slice selection function network element may still be the NSSF network element, or may have other names. This application does not limit this.

[0090] (9) NEF network element: This element is used to securely expose services and capabilities provided by 3GPP network functions to the outside world. In 5G communication systems, the network open network element may be an NEF network element. In future communication systems, such as 6G communication systems, the network open function network element may still be an NEF network element, or may have other names, which are not limited in this application. Nnef is a service-based interface provided by the NEF network element. The NEF network element can communicate with other network functions through Nnef.

[0091] (10) NRF network element: used to provide service registration, discovery and authorization, and maintain available network function (NF) instance information, which can realize on-demand configuration of network functions and services and interconnection between NFs. In the 5G communication system, the network storage network element can be an NRF network element. In future communication systems such as the 6G communication system, the network storage function network element can still be an NRF network element, or have other names, which is not limited in this application. Nnrf is a service-based interface provided by the NRF network element. The NRF network element can communicate with other network functions through Nnrf.

[0092] (11) NSSAAF network element: It is mainly responsible for the authentication and authorization of network slices and can interact with the authentication, authorization, and accounting server (AAA-S) through the authentication, authorization, and accounting proxy (AAA-P). Nnssaaf is a service-based interface provided by the NSSAAF network element. The NSSAAF network element can communicate with other network functions through Nnssaaf.

[0093] (12) UDR network element: used by UDM network elements to store or read subscription data and PCF network elements to store or read policy data. The UDR network element is not shown in Figure 1a.

[0094] (13) EASDF network element: Processes DNS messages according to the instructions of the SMF network element. For example, it is responsible for creating a DNS context for the PDU session and storing the IP address of the terminal device or the DNS message processing rules in the context. Optionally, the EASDF network element can also be used to discover EAS. For example, according to the DNS processing rules issued by the SMF network element, it processes the DNS request of the terminal device and selects the appropriate EAS for the terminal device. Neasdf is a service-based interface provided by the EASDF network element. The EASDF network element can communicate with other network functions through Neasdf.

[0095] As shown in Figure 1a, the terminal device can access the 5G communication system through access network devices such as (R)AN devices. The terminal device can communicate with the AMF network element through the next generation network (NG) 1 interface (N1 for short), the access network device can communicate with the AMF network element through the N2 interface (N2 for short), the access network device can communicate with the UPF network element through the N3 interface (N3 for short), the SMF network element can communicate with the UPF network element through the N4 interface (N4 for short), and the UPF network element can access the data network through the N6 interface (N6 for short).

[0096] Figure 1b is a schematic diagram of another possible communication system architecture applicable to an embodiment of the present application. As shown in Figure 1b, the communication system architecture may include a terminal device (such as UE), an access network (such as RAN), a core network and a data network. Unlike Figure 1a, Figure 1b illustrates multiple UPFs (such as UPF1, UPF2 and UPF3) and multiple DNs (such as DN1 and DN2). The access network includes access network network elements. For an introduction to the terminal device and the access network network elements of the access network, please refer to the functional description part of Figure 1a, which will not be repeated here. The UDR network element is not shown in Figure 1b.

[0097] The core network includes various core network elements and DN1 and DN2. DN1 is, for example, a central DN, and DN2 is, for example, an edge portion of the DN. Optionally, UPF1 can implement the function of an uplink classifier (UL CL) or a branching point (or branching point, BP), diverting part of the data services to DN1 and part of the data services to DN2. For example, UPF1 can be a UL CL UPF network element. Among them, UL CL / BP can be used to divert service traffic to different routes according to certain rules. The UE can access DN2 through UPF2 and access DN1 through UPF3. UPF2 and UPF3 are equivalent to implementing the function of a protocol data unit session anchor (PSA). For example, UPF2 can be an L-PSA UPF network element, and UPF3 can be a C-PSA UPF network element.

[0098] Core network elements may include NEF, NSSF, NSSAAF, NRF, PCF, AF, UDM, UDR, AMF, SMF, AUSF, UPF, and EASDF. The functions and interfaces of each element in Figure 1b can refer to those described in Figure 1a above. Furthermore, the SMF element communicates with the UPF1 element via the N4 interface, the SMF element communicates with the UPF2 element via the N4 interface, the SMF element communicates with the UPF3 element via the N4 interface, the UPF1 element communicates with the UPF3 element via the N9 interface (abbreviated as N9), the UPF3 element accesses DN1 via the N6 interface, and the UPF2 element accesses DN2 via the N6 interface.

[0099] It is understandable that in a session, the UPF network element directly connected to the data network DN through N6 can be called a PDU session anchor (PSA) (or a PSA UPF network element). Among them, the PSA deployed centrally or remotely (for example, UPF3) is called a central PSA (C-PSA) (or a C-PSA UPF network element), which can access the remote / cloud EHE or application server (AS); the PSA deployed locally (for example, UPF2) is called an L-PSA (or an L-PSA UPF network element), which can access the local EHE or EAS.

[0100] It should be understood that the above-mentioned network elements or functions can be network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (for example, a cloud platform). Optionally, the above-mentioned network elements or functions can be implemented by one device, or by multiple devices together, or can be a functional module within a device, and the embodiments of the present application do not specifically limit this. In addition, for the convenience of explanation, in the embodiments of the present application, "xxx network element" can also be referred to as "xxx", for example, the AMF network element can be referred to as AMF, and the SMF network element can be referred to as SMF.

[0101] It is understood that access network equipment, terminal equipment, and network elements in the core network can be referred to as communication devices. For example, access network equipment can be understood as a communication device with base station functions. Terminal equipment can be understood as a communication device with terminal functions. A network element in the core network can be understood as a device with core network element functions. For example, AMF can be understood as a communication device with AMF functions.

[0102] It should be noted that the communication system architecture shown in Figure 1a or Figure 1b is for the purpose of more clearly illustrating the technical solution of the embodiment of the present application, and does not constitute a limitation on the technical solution provided in the embodiment of the present application. Ordinary technicians in this field can know that with the evolution of the communication system architecture and the emergence of new business scenarios, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

[0103] The specific implementation of the communication method in the embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0104] It can be understood that Figure 2, Figure 4, or Figure 5 below uses multiple communication devices (such as multiple of the first network element, the second network element, the third network element, the fourth network element, the fifth network element, the sixth network element, the seventh network element, the eighth network element, the access network device, or the terminal device) as the execution subjects of the interaction diagram as an example for illustration, but the present application does not limit the execution subjects of the interaction diagram. For example, the first network element may be an SMF network element, the second network element may be a local session management function (local smf, L-SMF) network element, the third network element may be a UL CL UPF network element (or a user plane function network element with a traffic offload function), the fourth network element may be a UDM network element (or a UDR network element), the fifth network element may be an EASDF network element, the sixth network element may be an L-PSA UPF network element, the seventh network element may be an AMF network element, the eighth network element may be a session management policy control function (session management policy control function, SM-PCF) network element for session management, the terminal device may be a UE, and the access network device may be a RAN device.

[0105] It should be understood that the method performed by the first network element in the present application may also be performed by a module (e.g., a chip, a chip system, or a processor) applied to the first network element, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the first network element function. The method performed by the second network element in the present application may also be performed by a module (e.g., a chip, a chip system, or a processor) applied to the second network element, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the second network element function. The method performed by the third network element in the present application may also be performed by a module (e.g., a chip, a chip system, or a processor) applied to the third network element, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the third network element function. The method performed by the fourth network element in the present application may also be performed by a module (e.g., a chip, a chip system, or a processor) applied to the fourth network element, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the fourth network element function. The method performed by the fifth network element in the present application may also be performed by a module (such as a chip, a chip system, or a processor) applied to the fifth network element, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the fifth network element function. The method performed by the sixth network element in the present application may also be performed by a module (such as a chip, a chip system, or a processor) applied to the sixth network element, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the sixth network element function. The method performed by the seventh network element in the present application may also be performed by a module (such as a chip, a chip system, or a processor) applied to the seventh network element, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the seventh network element function. The method performed by the eighth network element in the present application may also be performed by a module (such as a chip, a chip system, or a processor) applied to the eighth network element, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the eighth network element function. The methods performed by the access network device in this application may also be performed by a module (such as a chip, a chip system, or a processor) applied to the access network device, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the functions of the access network device. The methods performed by the terminal device in this application may also be performed by a module (such as a chip, a chip system, or a processor) applied to the terminal device, and may also be implemented by a logical node, a logical module, or software that can implement all or part of the functions of the terminal device.

[0106] FIG2 exemplarily illustrates a flow chart of a communication method provided in an embodiment of the present application. The method is applicable to the communication system architecture shown in FIG1a or FIG1b. As shown in FIG2 , the method includes:

[0107] For example, the following takes the first network element as an SMF network element, the second network element as an L-SMF network element, the third network element as a UL CL UPF network element, the fifth network element as an EASDF network element, the sixth network element as an L-PSA UPF network element, the seventh network element as an AMF network element, and the eighth network element as an SM-PCF network element as an example to introduce the application scenarios applicable to the communication method shown in Figure 2.

[0108] Figure 3 is a schematic diagram of a possible application scenario provided by an embodiment of the present application. As shown in Figure 3, the application scenario includes a multi-layer network architecture, namely, a large region, a prefecture-level city core, and a district / venue / park. This can achieve the sharing of the management complexity of the centralized control plane in a hierarchical management manner. For example, the large region includes an AMF network element and an SMF network element. The prefecture-level city core includes an L-SMF network element, an SM-PCF network element, an EASDF network element, and a PSA UPF network element. The district / venue / park includes a UL CL UPF network element and an L-PSA UPF network element / MEC.

[0109] The following is a brief introduction to the functions of some network elements included in the application scenario shown in Figure 3:

[0110] a. For the relevant functions of the AMF network element, please refer to the functional description part of Figure 1a above for the functional content description of the AMF network element, which will not be repeated here.

[0111] b. SMF network element: (1) Manage UPF network elements in the existing manner; (2) Configure addressing strategy or DNS processing strategy to EASDF network element; (3) Select user plane function network element (such as UL CL UPF network element or PSA UPF network element) for the user and create forwarding path (such as path or channel for transmitting local service data), diversion strategy (or forwarding strategy or forwarding rule or distribution strategy or distribution rule) according to the address information of application server (such as EAS) returned by EASDF network element; (4) Obtain local policy information of terminal equipment (such as UE) from L-SMF network element (such as the policy of local service contract signed by terminal equipment); (5) Manage the selection and insertion of UL CL UPF network element; (6) Communicate with UDM network element to obtain information such as the identification of L-SMF network element corresponding to terminal equipment (such as UE).

[0112] c. L-SMF network element: (1) Manage local user plane function network elements, including selecting local user plane function network elements for user sessions, creating user plane forwarding paths, configuring diversion strategies to user plane function network elements, etc.; (2) Communicate with UDM network elements to obtain information such as the identification of the SMF network element corresponding to the terminal device (such as UE); (3) Obtain user policies from SM-PCF network elements and generate user plane policies; (4) Upload local policies (such as user plane policies) to SMF network elements.

[0113] d. SM-PCF network element: used to provide local user common policies, such as accessible applications, domain information, or locally configured policy information such as recorded user / application / network service quality.

[0114] e. EASDF network element: (1) adds address information to the user's DNS request and requests the address from the local DNS server; (2) sends the address information of the application server to the SMF network element, triggering the SMF network element to select the user plane function network element for the user (such as selecting the UL CL UPF network element) and create a forwarding path and diversion strategy.

[0115] f. PSA UPF network element: connects (or interfaces) with the DN located in the large network. For example, the PSA UPF network element connects with the DN located in the core of a prefecture-level city.

[0116] g. UL CL UPF network element: It has the offloading capability and can distribute the uplink data received from the terminal device to the corresponding PSA UPF network element (or L-PSA UPF network element) according to the offloading strategy, and can send the data received from the PSA UPF network element (or L-PSA UPF network element) to the terminal device.

[0117] h. L-PSA UPF network element: connects (or connects) to the DN (such as the campus enterprise private network) located in the local data center (DC) (such as mobile edge computing or multi-access edge computing). For example, when the terminal device is located at a location where there is a UPF network element connected to the local DN, the SMF network element can insert the UPF as an L-PSA UPF network element into the PDU session path so that the terminal device can access the application server in the local DN nearby.

[0118] It is understandable that the UL CL UPF network element and the L-PSA UPF network element can be set together, or the UL CL UPF network element and the L-PSA UPF network element can be set separately and independently, and the embodiments of the present application are not limited to this.

[0119] It should be understood that the communication scheme corresponding to the application scenario illustrated in Figure 3 is designed to not affect the centralized control plane when the local application policy is used for addressing or diverting user sessions. For example, large-scale updates and modifications of local application policies will not affect the centralized control plane. In addition, unlike the existing technology where the intermediate (intermediate) SMF (I-SMF) network element can directly manage the UL CL UPF network element, the L-SMF network element in this communication scheme will not participate in the management of the UL CL UPF network element. In this way, the management complexity of the centralized control plane can be reduced, and the routing path for terminal devices to access the edge application server can be optimized, thereby ensuring the service experience.

[0120] It is understandable that for the implementation of deploying the local application policy (or local user plane policy, such as the diversion policy), reference may be made to the technical solutions provided in the following steps 201 to 202 .

[0121] Step 201: The second network element sends a first message to the first network element. Correspondingly, the first network element receives the first message from the second network element.

[0122] Optionally, in an embodiment of the present application, if the first network element is replaced by a functional module such as a chip system, the functional module may not be aware of which device the received information comes from; if the second network element is replaced by a functional module such as a chip system, the functional module may not be aware of which device the sent information is sent to.

[0123] Among them, the first message may include a policy for the terminal device to access local services (or can be understood as a configuration policy for the terminal device to sign up for local services). The second network element (such as an L-SMF network element) can be used to manage the local user plane function network element (such as the sixth network element). Optionally, the first message may also include at least one of the following: FQDN, a data network access identifier (DNAI), or a fifth network element list (or a fifth network element identifier or a fifth network element index or a fifth network element name) pre-cached by the second network element, etc.

[0124] For example, local services may include, but are not limited to, edge services or regional services. The policy for a terminal device to access local services may be a local user-wide policy or a local application policy. For example, the policy for a terminal device to access local services may include a local addressing policy or a local traffic diversion policy.

[0125] It should be understood that the embodiment of the present application does not limit the circumstances under which the second network element sends the first message.

[0126] For example, in one example, the second network element may send a second subscription message to the fourth network element. After receiving the second subscription message from the second network element, the fourth network element may send the session information of the terminal device to the second network element. After receiving the session information of the terminal device from the fourth network element, the second network element may send a first message to the first network element based on the information of the first network element used to provide services for the terminal device included in the session information of the terminal device. The second subscription message may be used to subscribe to the session information of the terminal device, and the second subscription message may include identification information of the terminal device (such as an identity identifier, index or name, etc.). The information of the first network element may be used to establish a communication connection between the second network element and the first network element. For example, the information of the first network element may include identification information (such as an identity identifier) ​​or index information or name information or address information (such as an IP address) of the first network element; the session information of the terminal device may be carried (or carried or contained or included) in the response message of the second subscription message.

[0127] It is understandable that, after receiving the session information of the terminal device from the fourth network element, the second network element may establish a communication connection with the first network element based on the information of the first network element included in the session information of the terminal device. After the second network element establishes a communication connection with the first network element, the first network element may send a third message to the second network element. After receiving the third message from the first network element, the second network element may send the first message to the first network element based on the third message. Optionally, after the second network element establishes a communication connection with the first network element, the second network element may also proactively send the first message to the first network element. The third message may be used to request a policy for the terminal device to access local services. For example, the third message may carry identification information (such as an identity identifier, index, or name) of the terminal device or a service identifier (or service index or service name). Optionally, the policy for the terminal device to access local services may be obtained by the second network element from the eighth network element, or may be proactively pushed by the eighth network element to the second network element.

[0128] For example, the second subscription message may also include at least one of the following: data network name (DNN), single network slice selection assistance information (S-NSSAI), DNAI or area information, etc. Among them, the area information may include a specified (or indicated) area (or can be understood as an area range) for triggering the fourth network element to send the session information of the terminal device to the second network element. The area information is used to indicate that when the terminal device is located in the specified area, the fourth network element can send the session information of the terminal device to the second network element. Optionally, when the second subscription message includes the DNN, S-NSSAI, DNAI and other information corresponding to the terminal device, the DNN, S-NSSAI, DNAI and other information corresponding to the terminal device can be used by the fourth network element to determine whether to send the session information of the terminal device to the second network element. For example, when the DNN, S-NSSAI, DNAI and other information corresponding to the terminal device included in the second subscription message are the same as the DNN, S-NSSAI, DNAI and other information corresponding to the terminal device pre-stored by the fourth network element, the fourth network element can send the session information of the terminal device to the second network element.

[0129] In another example, the second network element may send an eighth message to the fourth network element. The eighth message may be used to trigger the establishment of a communication connection between the second network element and the first network element. After receiving the eighth message from the second network element, the fourth network element may send session information of the terminal device to the first network element. The session information of the terminal device may include information of the second network element providing services to the terminal device. After receiving the session information of the terminal device from the fourth network element, the first network element may establish a communication connection with the second network element based on the information of the second network element included in the session information of the terminal device. After the first network element establishes a communication connection with the second network element, the first network element may send a third message to the second network element. After receiving the third message from the first network element, the second network element may send the first message to the first network element based on the third message. Optionally, after the first network element establishes a communication connection with the second network element, the second network element may also proactively send the first message to the first network element.

[0130] It is understandable that the fourth network element sending the session information of the terminal device to the first network element may be triggered by the first network element pre-subscribing to the session information of the terminal device from the fourth network element. For example, the first network element may have sent a first subscription message to the fourth network element in advance. The first subscription message may be used to subscribe to the session information of the terminal device (such as subscribing to the information of the second network element corresponding to the terminal device). For example, the first subscription message may include identification information of the terminal device. When the session information of the terminal device is updated or the new session information of the terminal device is stored in the fourth network element, the fourth network element may send the new session information of the terminal device to the first network element. Optionally, the fourth network element sending the session information of the terminal device to the first network element may also be triggered by the active push mode of the fourth network element.

[0131] For example, the eighth message may include information of the second network element and identification information of the terminal device (such as an identity, index, or name, etc.). Exemplarily, the information of the second network element may include identification information (such as an identity) or index information or name information or address information (such as an IP address) of the second network element.

[0132] Optionally, the eighth message may also include at least one of the following: DNN, S-NSSAI, DNAI or area information, etc. Among them, the area information may include a designated area for triggering the fourth network element to send the session information of the terminal device to the first network element. The area information is used to indicate that when the terminal device is located in the designated area, the fourth network element can send the session information of the terminal device to the first network element. Optionally, when the eighth message includes the DNN, S-NSSAI, DNAI and other information corresponding to the terminal device, the DNN, S-NSSAI, DNAI and other information corresponding to the terminal device can be used by the fourth network element to determine whether to send the session information of the terminal device to the first network element. For example, when the DNN, S-NSSAI, DNAI and other information corresponding to the terminal device included in the eighth message is the same as the DNN, S-NSSAI, DNAI and other information corresponding to the terminal device pre-stored by the fourth network element, the fourth network element can send the session information of the terminal device to the first network element.

[0133] Step 202: The first network element sends a second message to the third network element. Correspondingly, the third network element receives the second message from the first network element.

[0134] The second message may be used to configure a diversion strategy for terminal devices to access local services, or the second message may be used to instruct a third network element to configure a diversion strategy for terminal devices to access local services. The diversion strategy for terminal devices to access local services is determined by the first network element based on a strategy for terminal devices to access local services (e.g., an addressing strategy corresponding to the local service).

[0135] For example, the process of determining the third network element (which may be understood as a selection process or an insertion process) is introduced below through the following possible implementation methods.

[0136] Method 1: When the policy for terminal devices to access local services does not include a diversion policy for terminal devices to access local services, the first network element can, after receiving the fifth message from the fifth network element (such as the EASDF network element), determine a user plane function network element as the third network element based on the fifth message and in accordance with the existing method for determining the third network element. It can be understood that the fifth message can be used to trigger the first network element to determine the third network element. Optionally, the fifth message may include the address information (such as an IP address) of the first application server (such as an EAS), or may also include the addressing policy corresponding to the local service, etc. The address information of the first application server may be obtained based on a domain name query initiated by the terminal device.

[0137] The following describes the implementation process of the first network element selecting the fifth network element through the following possible examples.

[0138] Example 1: During the process of completing the session creation request of the terminal device, the first network element selects a fifth network element for the session of the terminal device (such as the current user session or the current PDU session) according to the existing method of selecting the fifth network element. For example, the fifth network element can be used to forward the domain name query request (such as a DNS query request) from the terminal device to the DNS server, and forward the response message from the DNS server to the terminal device. The DNS server can be used to select an application server for the user corresponding to the terminal device, and the distance from the terminal device to the location is less than or equal to a first distance threshold. The application server can be used to provide corresponding application services for the terminal device. In this way, when the user needs to access a certain application, the network side can help the user find a nearby application server that supports the application and create the shortest possible path to access the application, thereby reducing the access delay.

[0139] Example 2: When the policy for the terminal device to access local services does not include the addressing policy corresponding to the local services, and the terminal device's session does not select the fifth network element, the first network element can select a fifth network element for the terminal device's session according to the existing method of selecting the fifth network element.

[0140] For example, when the first network element adopts the existing method for selecting the fifth network element, it can select a fifth network element as the fifth network element corresponding to the session of the terminal device through at least one of the following information: DNN, S-NSSAI, DNAI, information of the second network element (such as area information (or can be understood as service range or service area)), a fifth network element list provided by the second network element (or a fifth network element identifier or a fifth network element index or a fifth network element name) or the location of the terminal device. Optionally, the fifth network element list may include an identifier (or index or name) of at least one fifth network element, etc. It can be understood that the above-mentioned fifth network element list (or fifth network element identifier or fifth network element index or fifth network element name) can be an available fifth network element list (or fifth network element identifier or fifth network element index or fifth network element name) locally cached (or pre-cached) by the second network element.

[0141] Optionally, when the information of the second network element includes the service range of the second network element, the first network element may select a fifth network element whose service range includes the service range of the second network element as the fifth network element corresponding to the session of the terminal device; or, when the information of the second network element includes the location information of the second network element, the first network element may also select a fifth network element whose distance to the location of the second network element is less than or equal to a second distance threshold as the fifth network element corresponding to the session of the terminal device.

[0142] For example, the first network element is an SMF network element, the second network element is an L-SMF network element, and the fifth network element is an EASDF network element. The at least one information includes the information of the L-SMF network element (such as service range or location information) and the EASDF network element list provided by the L-SMF network element. The fifth network element list includes 3 EASDF network elements (such as EASDF network element 1, EASDF network element 2 and EASDF network element 3). The session of the terminal device is the current PDU session of the UE. Each EASDF network element has its own service range, such as the service range of EASDF network element 1 is a1, the service range of EASDF network element 2 is a2, and the service range of EASDF network element 3 is a3. Each EASDF network element has its own location, such as the location of EASDF network element 1 is s1, the location of EASDF network element 2 is s2, and the location of EASDF network element 3 is s3. In one example, when the information of the L-SMF network element includes the service range of the L-SMF network element (such as service range a0), the SMF network element may select an EASDF network element whose service range includes the service range a0 from the three EASDF network elements as the EASDF network element corresponding to the current PDU session of the UE, such as EASDF network element 2. The service range a0 of the L-SMF network element is included in the service range a2 of the EASDF network element 2. In another example, when the information of the L-SMF network element includes the location information of the L-SMF network element (such as location a), the SMF network element may select an EASDF network element whose distance from the location a of the L-SMF network element is less than or equal to a second distance threshold (such as r) from the three EASDF network elements as the EASDF network element corresponding to the current PDU session of the UE, such as EASDF network element 1. The distance value between the location s1 of the EASDF network element 1 and the location a of the L-SMF network element is less than or equal to r.

[0143] It is understandable that, when the policy for the terminal device to access the local service does not include the addressing policy corresponding to the local service, the first network element may send a fourth message to the fifth network element after selecting a fifth network element as the fifth network element corresponding to the session of the terminal device. For example, the fourth message may include the addressing policy corresponding to the local service. The fourth message may be used to configure the addressing policy corresponding to the local service, or the fourth message may also be used to instruct the fifth network element to configure the addressing policy corresponding to the local service. For example, the addressing policy corresponding to the local service may be created (or may be called generated) by the first network element for the fifth network element based on the policy for the terminal device to access the local service. Afterwards, the first network element may send the address information (such as an IP address or a physical address, etc.) of the fifth network element to the terminal device. The address information of the fifth network element may be used for the terminal device to perform subsequent domain name queries.

[0144] Optionally, in an embodiment of the present application, the fifth network element can also be selected through the second network element. For example, when the second network element has a list of fifth network elements pre-cached locally, the second network element can adopt the existing fifth network element selection method and select a fifth network element from the fifth network element list as the fifth network element corresponding to the session of the terminal device. For example, when the second network element adopts the existing fifth network element selection method, it can select the fifth network element through at least one of the following information: DNN, S-NSSAI, DNAI, information of the second network element (such as area information (or can be understood as service range or service area)), the fifth network element list or the location of the terminal device, etc.

[0145] After selecting the fifth network element corresponding to the session of the terminal device, the second network element may send a sixth message to the fifth network element. For example, the sixth message may include an addressing policy corresponding to the local service. The sixth message may be used to configure the addressing policy corresponding to the local service, or the sixth message may also be used to instruct the fifth network element to configure the addressing policy corresponding to the local service, and the addressing policy is included in the policy for the terminal device to access the local service. After selecting the fifth network element corresponding to the session of the terminal device, the second network element may also send a seventh message to the first network element. For example, the seventh message may include identification information and / or address information of the fifth network element. The identification information and / or address information of the fifth network element may be used to establish a communication connection between the first network element and the fifth network element.

[0146] It is understandable that when a user needs to access a certain application, the user can send a DNS request to the fifth network element through the terminal device based on the address information of the fifth network element. The DNS request is used to obtain the address information of the application server that supports the application. After receiving the DNS request, the fifth network element can forward the DNS request to the DNS server according to the configured addressing policy. After receiving the DNS request, the DNS server can select an application server for the user that is less than or equal to the first distance threshold from the location of the terminal device based on the client subnet option information of the DNS extended mechanism (extended mechanisms for DNS) carried in the DNS request for indicating the location of the terminal device, and can send a DNS response message to the fifth network element. The DNS response message can include the address information of the application server. After receiving the DNS response message, the fifth network element can send the DNS response message to the terminal device. Optionally, after receiving the DNS response message, the fifth network element can send a sixth message to the first network element based on the DNS response message.

[0147] Method 2: When the policy for terminal devices to access local services includes a diversion policy for terminal devices to access local services, the first network element can determine a user plane function network element as the third network element according to the diversion policy for terminal devices to access local services and the existing method for determining the third network element.

[0148] For example, when the first network element adopts the existing third network element determination method, it can determine a user plane function network element as the third network element through at least one of the following information: the location of the terminal device, a list of data networks supported by multiple user plane function network elements, the service ranges corresponding to the multiple user plane function network elements, the loads corresponding to the multiple user plane function network elements, or the sessions and service continuity (SSC) modes supported by the multiple user plane function network elements. It can be understood that the location of the terminal device can refer to user location information (ULI).

[0149] Method three: The third network element may be pre-configured or pre-defined through a protocol.

[0150] The following describes the implementation process of the first network element determining the diversion strategy for terminal devices to access local services through the following possible implementation methods.

[0151] Implementation method 1: When the policy for terminal devices to access local services includes a diversion policy for terminal devices to access local services, the first network element can directly carry the diversion policy for terminal devices to access local services in the second message, or can also directly carry the policy for terminal devices to access local services in the second message.

[0152] Implementation method 2: When the policy for terminal device access to local services does not include a diversion policy for terminal device access to local services, the first network element may create a diversion policy for terminal device access to local services based on the policy for terminal device access to local services (such as the addressing policy corresponding to the local service). The first network element may then include the diversion policy for terminal device access to local services in the second message.

[0153] Implementation method three: When the policy for terminal device access to local services does not include a diversion policy for terminal device access to local services, after receiving the fifth message from the fifth network element (e.g., the EASDF network element), the first network element may determine the third network element based on the fifth message. Thereafter, the first network element may create a diversion policy for terminal device access to local services based on the policy for terminal device access to local services (e.g., the addressing policy corresponding to the local service).

[0154] Optionally, in an embodiment of the present application, after the first network element determines the third network element, the first network element may send fourth information to the third network element. For example, the fourth information may be an N4 session modification request (or session modification request), or an N4 session creation request (or session creation request), requesting the third network element to allocate a corresponding uplink tunnel identifier and / or downlink tunnel identifier. The fourth information may include the downlink tunnel identifier of the access network device. Optionally, the fourth information may also include at least one of the following: requesting the third network element to allocate an uplink tunnel identifier and / or downlink tunnel identifier, or requesting the third network element to update a traffic diversion policy (e.g., sending uplink packets with specified characteristics to the local network). After receiving the fourth information from the first network element, the third network element may send fifth information to the first network element. For example, the fifth information may include the uplink tunnel identifier and / or downlink tunnel identifier of the third network element. In one example, if the uplink tunnel identifier of the third network element is updated, the fifth information may include the downlink tunnel identifier of the third network element and / or the updated uplink tunnel identifier. In another example, if the downlink tunnel identifier of the third network element is updated, the fifth information may also include the uplink tunnel identifier and / or the updated downlink tunnel identifier of the third network element. In yet another example, if both the uplink tunnel identifier and the downlink tunnel identifier of the third network element are updated, the fifth information may include the updated downlink tunnel identifier and / or the updated uplink tunnel identifier of the third network element.

[0155] It is understandable that after the first network element determines the third network element, the first network element may also send the first information to the second network element. For example, the first information may be a session modification request, or a session creation request, including additional N4 information for requesting the uplink tunnel identifier of the sixth network element. The first information may be used to request allocation of the uplink tunnel identifier of the sixth network element. The first information may include the downlink tunnel identifier of the third network element. The sixth network element is a local user plane function network element. Optionally, the first information may also include at least one of the following: DNN, S-NSSAI, or identification information of the terminal device. It is understandable that the first information may also notify the second network element to send the downlink tunnel identifier of the third network element to the sixth network element, so as to establish a user plane tunnel (or a communication tunnel) between the third network element and the sixth network element. After receiving the first information from the first network element, the second network element may send the sixth information to the sixth network element. For example, the sixth information may be an N4 session modification request, or an N4 session creation request. The sixth information may be used to request allocation of an uplink tunnel identifier for the sixth network element, and the sixth information may include the downlink tunnel identifier of the third network element. After receiving the sixth information from the second network element, the sixth network element may send seventh information to the second network element. For example, the seventh information may be a session modification response or an N4 session creation response. The seventh information may include the uplink tunnel identifier of the sixth network element. After receiving the seventh information from the sixth network element, the second network element may send second information to the first network element. The second information may include the uplink tunnel identifier of the sixth network element. After receiving the second information from the second network element, the first network element may send third information to the third network element. The third information may include the uplink tunnel identifier of the sixth network element. In this way, the third network element and the sixth network element can establish a first user plane tunnel corresponding to the local service using the uplink tunnel identifier of the sixth network element and the downlink tunnel identifier of the third network element. Subsequently, the third network element and the sixth network element can transmit local service data via the first user plane tunnel.

[0156] Optionally, if the fifth information includes the updated uplink tunnel identifier of the third network element, the first network element may send the updated uplink tunnel identifier of the third network element to the access network device. In this way, the third network element and the access network device may establish a second user plane tunnel corresponding to the local service through the downlink tunnel identifier of the access network device and the updated uplink tunnel identifier of the third network element. Subsequently, the access network device and the third network element may transmit local service data through the second user plane tunnel. If the fifth information includes the uplink tunnel identifier of the third network element, the first network element may send the uplink tunnel identifier of the third network element to the access network device. In this way, the third network element and the access network device may establish a user plane tunnel corresponding to the local service through the downlink tunnel identifier of the access network device and the uplink tunnel identifier of the third network element. Subsequently, the access network device and the third network element may transmit local service data through the user plane tunnel.

[0157] If the fifth information includes the updated downlink tunnel identifier of the third network element (or the downlink tunnel identifier of the third network element), the first network element may send the updated downlink tunnel identifier of the third network element (or the downlink tunnel identifier of the third network element) to the second network element. After receiving the updated downlink tunnel identifier of the third network element, the second network element may send the updated downlink tunnel identifier of the third network element (or the downlink tunnel identifier of the third network element) to the sixth network element. In one example, if the uplink tunnel identifier of the sixth network element has not been updated, the sixth network element sends a response message to the second network element indicating that the updated downlink tunnel identifier has been received. After receiving the response message, the second network element may send the response message to the first network element. In this way, a user plane tunnel corresponding to the local service can be established between the third network element and the sixth network element using the uplink tunnel identifier of the sixth network element and the updated downlink tunnel identifier of the third network element (or the downlink tunnel identifier of the third network element). Subsequently, local service data can be transmitted between the third network element and the sixth network element through the user plane tunnel.

[0158] In another example, if the uplink tunnel identifier of the sixth network element is updated, the response message sent by the sixth network element to the second network element carries the updated uplink tunnel identifier of the sixth network element. After receiving the response message, the second network element can send the response message to the first network element. After receiving the response message, the first network element can obtain the updated uplink tunnel identifier of the sixth network element from the response message and send the updated uplink tunnel identifier of the sixth network element to the third network element. In this way, the user plane tunnel corresponding to the local service can be established between the third network element and the sixth network element through the updated uplink tunnel identifier of the sixth network element and the updated downlink tunnel identifier of the third network element (or the downlink tunnel identifier of the third network element). Subsequently, local service data can be transmitted between the third network element and the sixth network element through the user plane tunnel.

[0159] It can be seen from the above steps 201 to 202 that the user plane management (such as the management of the sixth network element) and user policy management (or local user plane policy management, such as the management of the policy for the terminal device to sign up for local services) within the domain are performed by the second network element. This can avoid direct management of the centralized control plane, so that when user services (which can be understood as local services) are deployed / activated / changed within the domain, the centralized control plane can be unaware of the deployment / activation / change of local service policies or local service logic, thereby effectively alleviating (or reducing) the management complexity of the centralized control plane.

[0160] Based on the technical solution of the communication method illustrated in FIG. 2 above, the communication method illustrated in FIG. 2 is described in detail below through the specific examples shown in FIG. 4 and FIG. 5 . In the specific examples shown in FIG. 4 and FIG. 5 , the first network element is an SMF network element, the second network element is an L-SMF network element, the third network element is a UL CL UPF network element, the fourth network element is a UDM network element, the fifth network element is an EASDF network element, the sixth network element is an L-PSA UPF network element, the seventh network element is an AMF network element, the eighth network element is an SM-PCF network element, the terminal device is a UE, and the access network device is a RAN device. It can be understood that the communication solution illustrated in FIG. 4 is applicable to the scenario where, when the UE is continuously online and the PSA UPF remains unchanged, the UE signs up for a local service and subsequently performs the session modification process required for local services in a county / park / venue. The communication solution illustrated in FIG. 5 is applicable to the scenario where, after the UE signs up for a local service, the L-SMF network element obtains the local policy and completes the subscription of the UE's relevant session information to the UDM network element. Afterwards, when the UE re-establishes the session, the process of creating a local service session in the UE session is triggered. In other words, the communication solution shown in Figure 5 is applicable to the scenario where the UE first subscribes to a local service, goes offline, and then comes back online to access the local service.

[0161] FIG4 is a flow chart of another communication method provided in an embodiment of the present application. As shown in FIG4 , the specific flow of the method may include:

[0162] Step 401: The UE completes session creation.

[0163] Optionally, the above step 401 can reuse the existing session creation process, which will not be described again here.

[0164] In the embodiment of the present application, the UE regional session is created through the SMF network element and the PSA UPF network element. During this process, relevant information of the SMF network element that provides corresponding services to the UE (such as identification information of the SMF network element, etc.) and relevant information of the UE (such as identification information of the UE, etc.) can be registered in the UDM network element. Optionally, in step 401, the SMF network element can also select an EASDF network element as the EASDF network element corresponding to the UE session according to the existing method of selecting the EASDF network element.

[0165] Step 402: The L-SMF network element obtains the policy for UE to access local services from the SM-PCF network element.

[0166] In an embodiment of the present application, after the UE signs up for a local service (for example, by scanning a code, etc.), the L-SMF network element may request the SM-PCF network element to obtain the UE's policy for accessing local services, or the SM-PCF network element may actively push the UE's policy for accessing local services to the L-SMF network element. Optionally, the process of establishing a communication connection between the L-SMF network element and the SM-PCF network element may refer to the process of establishing a communication connection between the SMF network element and the PCF network element in the prior art, which will not be repeated here.

[0167] Step 403: A communication connection is established between the SMF network element and the L-SMF network element.

[0168] For example, the following describes the implementation process of establishing a communication connection between an SMF network element and an L-SMF network element through the following possible examples.

[0169] Example 1: The L-SMF network element sends a subscription message to the UDM network element. The subscription message is used to subscribe to the relevant session information of the UE. The subscription message may include the identification information and / or session information of the UE. Optionally, the subscription message may also include at least one of the following: area information, S-NSSAI, DNAI or DNN, etc. The area information is used to indicate that when the UE is located in the specified area included in the area information, the UDM network element is triggered to send the relevant session information of the UE (such as the identification information of the SMF network element that provides services for the UE's session) to the L-SMF network element; information such as S-NSSAI, DNAI or DNN can be used by the UDM network element to determine whether to trigger the sending of the relevant session information of the UE to the L-SMF network element. For example, when the subscription message includes information such as S-NSSAI, DNAI or DNN, if the information such as S-NSSAI, DNAI or DNN is the same as the locally cached information such as S-NSSAI, DNAI or DNN, the UDM network element can send the relevant session information of the UE to the L-SMF network element.

[0170] Afterwards, the UDM network element may send a response message to the subscription message to the L-SMF network element. The response message to the subscription message may include the identification information of the SMF network element that provides services for the UE's session. In this way, after receiving the response message to the subscription message, the L-SMF network element may obtain the identification information of the SMF network element from the response message to the subscription message, and may establish a communication connection with the SMF network element based on the identification information of the SMF network element.

[0171] Example 2: The L-SMF network element sends the eighth message to the UDM network element. For example, the eighth message may include information about the L-SMF network element and identification information of the corresponding UE. Optionally, the eighth message may also include at least one of the following: DNN, S-NSSAI, DNAI or area information, etc. After receiving the eighth message, the UDM network element may determine the identification information of the L-SMF network element responsible for local services corresponding to the currently serving UE based on the information of the L-SMF network element and the identification information of the UE included in the eighth message, and may send relevant session information of the UE to the SMF network element. The relevant session information of the UE may include the identification information of the L-SMF network element. After receiving the relevant session information of the UE, the SMF network element may obtain the identification information of the L-SMF network element from the relevant session information of the UE, and may establish a communication connection with the L-SMF network element based on the identification information of the L-SMF network element. It can be understood that before the UDM network element sends the relevant session information of the UE to the SMF network element, the SMF network element subscribes to the relevant session information of the UE from the UDM network element. For example, when the eighth message includes information such as S-NSSAI, DNAI or DNN, the UDM network element can determine whether to send the relevant session information of the UE to the SMF network element based on the S-NSSAI, DNAI or DNN information included in the eighth message. If the S-NSSAI, DNAI or DNN information is the same as the locally cached S-NSSAI, DNAI or DNN information, the UDM network element can send the relevant session information of the UE to the SMF network element.

[0172] Step 404: The L-SMF network element sends a first message to the SMF network element. Correspondingly, the SMF network element receives the first message from the L-SMF network element.

[0173] Optionally, the relevant implementation process of step 404 can refer to the relevant implementation process of the above-mentioned step 201, which will not be repeated here.

[0174] Optionally, after executing step 404, the SMF network element can also execute steps 405 to 407. By executing steps 405 to 407, the SMF network element can select the EASDF network element for the user session corresponding to the UE based on the relevant user session information provided by the L-SMF network element (such as DNN, S-NSSAI, DNAI, information of the second network element or one or more of the fifth network element list, etc.) when the policy for the UE to access local services does not include the addressing policy corresponding to the local services and the user session of the UE does not select the EASDF network element.

[0175] Step 405: When the policy for the UE to access local services does not include the addressing policy corresponding to the local services, and the UE's session does not select the EASDF network element, the SMF network element selects the EASDF network element for the UE's session.

[0176] Optionally, the relevant implementation process of step 405 can refer to the relevant implementation process described in Example 2 of the above step 202, and will not be repeated here.

[0177] Step 406: The SMF network element sends a fourth message to the EASDF network element. Correspondingly, the EASDF network element receives the fourth message from the SMF network element.

[0178] Optionally, the relevant implementation process of step 406 can refer to the relevant implementation process of the first network element sending the fourth message to the fifth network element in the above step 202, which will not be repeated here.

[0179] Step 407: The SMF network element sends the address information of the EASDF network element to the UE. Correspondingly, the UE receives the address information of the EASDF network element from the SMF network element.

[0180] The address information (such as IP address, etc.) of the EASDF network element may be used by the UE for subsequent domain name query, for example, the UE may initiate a DNS request.

[0181] Step 408: The UE sends a DNS request to the EASDF network element. Correspondingly, the EASDF network element receives the DNS request from the UE.

[0182] The DNS request is used to obtain the address information of an application server that supports an application that the user corresponding to the UE needs to access.

[0183] Step 409: The EASDF network element forwards the DNS request to the DNS server according to the configured addressing policy corresponding to the local service, and receives a DNS response message from the DNS server.

[0184] The DNS response message may include address information of an application server selected by the DNS server for the user to support the application to be accessed.

[0185] Step 410: The EASDF network element sends a fifth message to the SMF network element according to the DNS response message. Correspondingly, the SMF network element receives the fifth message from the EASDF network element.

[0186] Optionally, the description of the fifth message in step 410 may refer to the description of the fifth message in step 202 above, which will not be repeated here.

[0187] It should be understood that the above steps 405 to 410 are optional steps.

[0188] Step 411: The SMF network element determines the UL CL UPF network element.

[0189] Optionally, the relevant implementation process of step 411 can refer to the determination process of the third network element in the above step 202, which will not be repeated here.

[0190] Step 412: The SMF network element sends the fourth information to the UL CL UPF network element. Correspondingly, the UL CL UPF network element receives the fourth information from the SMF network element.

[0191] For example, the fourth information may be an N4 session modification request.

[0192] Optionally, the relevant implementation process of step 412 can refer to the relevant implementation process of the first network element sending the fourth information to the third network element in the above step 202, which will not be repeated here.

[0193] Step 413: The SMF network element sends the first information to the L-SMF network element. Correspondingly, the L-SMF network element receives the first information from the SMF network element.

[0194] For example, the first information may be a session modification request.

[0195] Optionally, the relevant implementation process of step 413 can refer to the relevant implementation process of the first network element sending the first information to the second network element in the above step 202, which will not be repeated here.

[0196] Step 414: The L-SMF network element sends the sixth information to the L-PSA UPF network element. Correspondingly, the L-PSA UPF network element receives the sixth information from the L-SMF network element.

[0197] For example, the sixth information may be an N4 session modification request.

[0198] Optionally, the relevant implementation process of step 414 can refer to the relevant implementation process of the second network element sending the sixth information to the sixth network element in the above step 202, which will not be repeated here.

[0199] Step 415: The L-PSA UPF network element sends the seventh information to the L-SMF network element. Correspondingly, the L-SMF network element receives the seventh information from the L-PSA UPF network element.

[0200] For example, the seventh message is a session modification response.

[0201] Optionally, the relevant implementation process of step 415 can refer to the relevant implementation process of the sixth network element sending the seventh information to the second network element in the above step 202, which will not be repeated here.

[0202] Step 416: The L-SMF network element sends the second information to the SMF network element. Correspondingly, the SMF network element receives the second information from the L-SMF network element.

[0203] Optionally, the relevant implementation process of step 416 can refer to the relevant implementation process of the second network element sending the second information to the first network element in the above step 202, which will not be repeated here.

[0204] Step 417: The SMF network element sends the third information to the UL CL UPF network element. Correspondingly, the UL CL UPF network element receives the third information from the SMF network element.

[0205] Optionally, the relevant implementation process of step 417 can refer to the relevant implementation process of the first network element sending the third information to the third network element in the above step 202, which will not be repeated here.

[0206] Step 418: The SMF network element sends the ninth message to the L-SMF network element. Correspondingly, the L-SMF network element receives the ninth message from the SMF network element.

[0207] In an embodiment of the present application, when the SMF network element sends the ninth message to the L-SMF network element, the user plane tunnel for transmitting local service data is established. For example, the ninth message can be a session modification completion response. The ninth message can be used to indicate that the session modification is completed.

[0208] Optionally, when the above step 410 is executed, the SMF network element also needs to send a session modification completion response to the EASDF network element.

[0209] Optionally, when step 408 is executed, the EASDF network element needs to send a DNS request response message to the UE, where the DNS request response message is used to indicate that the user plane tunnel required for transmitting local service data is established and the user can start local services.

[0210] As can be seen from the above steps 401 to 418, the SMF network element can select the user plane network element it manages as the UL CL UPF network element for the UE based on the diversion policy or addressing policy corresponding to the local service provided by the L-SMF network element, and can configure the diversion policy for the UL CL UPF network element. In addition, if the policy for the UE to access local services does not include the addressing policy corresponding to the local service and the UE's user session does not select the EASDF network element, the SMF network element can select the EASDF network element for the UE's corresponding user session and can configure the addressing policy for the EASDF network element. Optionally, the SMF network element can also configure the DNS processing policy for the EASDF network element. In this way, when the L-SMF network element manages the local user plane function network element and the local user plane policy, this method can achieve that the centralized SMF network element is unaware of the deployment of user plane network elements and applications within the domain (or can be understood as local), and is unaware of the policy generation method for the user's services within the domain, thereby reducing the management complexity of the centralized SMF network element and other control network elements.

[0211] It can be understood that compared with the existing technology, the communication solution provided by the above steps 401 to 418 is that the L-SMF network element performs user plane management and user policy management within the domain, which can avoid direct management of the centralized control plane, so that when user services (which can be understood as local services) are deployed / activated / changed within the domain, the centralized control plane may not perceive the deployment / activation / change of local service policies or local service logic, thereby effectively reducing the management complexity of the centralized control plane.

[0212] FIG5 is a flow chart of another communication method provided in an embodiment of the present application. As shown in FIG5 , the specific flow of the method may include:

[0213] Step 501: The L-SMF network element obtains the policy for UE to access local services from the SM-PCF network element.

[0214] Optionally, the relevant implementation process of step 501 can refer to the relevant implementation process of the above-mentioned step 402, which will not be repeated here.

[0215] Step 502: A communication connection is established between the SMF network element and the L-SMF network element.

[0216] For example, the following describes the implementation process of establishing a communication connection between an SMF network element and an L-SMF network element through the following possible examples.

[0217] Example 1: The L-SMF network element sends a subscription message to the UDM network element. The subscription message is used to subscribe to the relevant session information of the UE. The subscription message may include the identification information and / or session information of the UE. Optionally, the subscription message may also include at least one of the following: area information, S-NSSAI, DNAI or DNN, etc. The area information is used to indicate that when the UE is located in the specified area included in the area information, the UDM network element is triggered to send the relevant session information of the UE (such as the identification information of the SMF network element that provides services for the UE's session) to the L-SMF network element; information such as S-NSSAI, DNAI or DNN can be used by the UDM network element to determine whether to trigger the sending of the relevant session information of the UE to the L-SMF network element. For example, when the subscription message includes information such as S-NSSAI, DNAI or DNN, if the information such as S-NSSAI, DNAI or DNN is the same as the locally cached information such as S-NSSAI, DNAI or DNN, the UDM network element is triggered to send the relevant session information of the UE to the L-SMF network element. It should be understood that the process of the L-SMF network element sending the subscription message to the UDM network element is performed when the UE is online.

[0218] When the UDM network element initiates a session creation request after the UE goes offline (for example, the UE is powered off) and comes back online, it may send a tenth message to the L-SMF network element. The tenth message may include identification information of the SMF network element that provides services for the UE's session, so that a communication connection can be established between the L-SMF network element and the SMF network element. Optionally, after the UE goes offline and comes back online, it sends a session creation request to the RAN device, which then sends the session creation request to the AMF network element. After receiving the session creation request, the AMF network element selects the corresponding SMF network element for the UE's user session. Thereafter, the AMF network element sends a session creation request to the SMF network element. For example, the session creation request may include at least one of the following: a tunnel identifier of the RAN device (such as an uplink tunnel identifier or a downlink tunnel identifier), a DNN, or an S-NSSAI. It should be understood that during the session creation process, information (such as identification information) of the SMF network element corresponding to the UE and information (such as identification information) of the AMF network element may be registered with the UDM network element.

[0219] Example 2: The L-SMF network element sends the eighth message to the UDM network element. For example, the eighth message may include information of the L-SMF network element and identification information of the UE. Optionally, the eighth message may also include at least one of the following: DNN, S-NSSAI, DNAI or area information, etc. It should be understood that the process of the L-SMF network element sending the eighth message to the UDM network element is performed when the UE is online. The L-SMF network element sending the eighth message to the UDM network element can be understood as the L-SMF network element actively registering its own related information (such as the corresponding information included in the eighth message) to the UDM network element.

[0220] When the UDM network element initiates a session creation request after the UE goes offline (for example, the UE is turned off) and comes back online, it can send the relevant session information of the UE to the SMF network element corresponding to the current service UE and responsible for local services. Among them, the relevant session information of the UE may include the identification information of the L-SMF network element. After receiving the relevant session information of the UE, the SMF network element can obtain the identification information of the L-SMF network element from the relevant session information of the UE, and can establish a communication connection with the L-SMF network element based on the identification information of the L-SMF network element. It can be understood that before the UDM network element sends the relevant session information of the UE to the SMF network element, the SMF network element subscribes to the relevant session information of the UE to the UDM network element. For example, when the eighth message includes information such as S-NSSAI, DNAI or DNN, the UDM network element can determine whether to send the relevant session information of the UE to the SMF network element based on the information such as S-NSSAI, DNAI or DNN included in the eighth message. If the information such as S-NSSAI, DNAI or DNN is the same as the locally cached information such as S-NSSAI, DNAI or DNN, the UDM network element can send the relevant session information of the UE to the SMF network element. Optionally, after the UE goes offline and comes back online, it sends a session creation request to the RAN device, and the RAN device sends the session creation request to the AMF network element. After receiving the session creation request, the AMF network element selects the corresponding SMF network element for the UE's user session. Afterwards, the AMF network element sends a session creation request to the SMF network element. For example, the session creation request may include at least one of the following: a tunnel identifier of the RAN device (such as an uplink tunnel identifier or a downlink tunnel identifier), a DNN or S-NSSAI, etc. It should be understood that during the session creation process, the information of the SMF network element corresponding to the UE (such as identification information) and the information of the AMF network element (such as identification information) can be registered in the UDM network element.

[0221] Step 503: The L-SMF network element sends a first message to the SMF network element. Correspondingly, the SMF network element receives the first message from the L-SMF network element.

[0222] Optionally, the relevant implementation process of step 404 can refer to the relevant implementation process of the above-mentioned step 201, which will not be repeated here.

[0223] Optionally, after executing step 503, the embodiment of the present application may further execute steps 504 to 506 or steps 507 to 508. For example, if the L-SMF network element has the function of configuring the EASDF network element, the L-SMF network element configures the EASDF network element, and the L-SMF network element completes the corresponding configuration of the EASDF network element by executing steps 504 to 506, thereby reducing the management complexity of the centralized control plane (such as the centralized SMF network element). If the L-SMF network element does not have the function of configuring the EASDF network element, the SMF network element configures the EASDF network element, and the SMF network element completes the corresponding configuration of the EASDF network element by executing steps 507 to 508.

[0224] Step 504: The L-SMF network element selects an EASDF network element for the UE's session.

[0225] Optionally, the relevant implementation process of step 504 can refer to the relevant implementation process of the second network element selecting the fifth network element in the above step 202, which will not be repeated here.

[0226] Step 505: The L-SMF network element sends the sixth message to the EASDF network element. Correspondingly, the EASDF network element receives the sixth message from the L-SMF network element.

[0227] Optionally, the relevant implementation process of step 505 can refer to the relevant implementation process of the second network element sending the sixth message to the fifth network element in the above step 202, which will not be repeated here.

[0228] Step 506: The L-SMF network element sends the seventh message to the SMF network element. Correspondingly, the SMF network element receives the seventh message from the L-SMF network element.

[0229] Optionally, the relevant implementation process of step 506 can refer to the relevant implementation process of the second network element sending the seventh message to the first network element in the above step 202, which will not be repeated here.

[0230] Step 507: When the policy for the UE to access the local service does not include the addressing policy corresponding to the local service, and the UE's session does not select the EASDF network element, the SMF network element selects the EASDF network element for the UE's session.

[0231] Optionally, the relevant implementation process of step 507 may refer to the relevant implementation process described in Example 2 of the above step 202, and will not be repeated here.

[0232] Step 508: The SMF network element sends a fourth message to the EASDF network element. Correspondingly, the EASDF network element receives the fourth message from the SMF network element.

[0233] Optionally, the relevant implementation process of step 508 can refer to the relevant implementation process of the first network element sending the fourth message to the fifth network element in the above step 202, which will not be repeated here.

[0234] Step 509: The SMF network element sends the address information of the EASDF network element to the UE. Correspondingly, the UE receives the address information of the EASDF network element from the SMF network element.

[0235] The address information (such as IP address, etc.) of the EASDF network element may be used by the UE for subsequent domain name query, for example, the UE may initiate a DNS request.

[0236] It should be understood that the above steps 504 to 509 are optional steps.

[0237] Step 510: The SMF network element determines the UL CL UPF network element.

[0238] Optionally, the relevant implementation process of step 510 can refer to the determination process of the third network element in the above step 202, which will not be repeated here.

[0239] Step 511: The SMF network element sends the fourth information to the UL CL UPF network element. Correspondingly, the UL CL UPF network element receives the fourth information from the SMF network element.

[0240] For example, the fourth information may be an N4 session creation request.

[0241] Optionally, the relevant implementation process of step 511 can refer to the relevant implementation process of the first network element sending the fourth information to the third network element in the above step 202, which will not be repeated here.

[0242] Step 512: The SMF network element sends the first information to the L-SMF network element. Correspondingly, the L-SMF network element receives the first information from the SMF network element.

[0243] For example, the first information may be a session creation request.

[0244] Optionally, the relevant implementation process of step 512 can refer to the relevant implementation process of the first network element sending the first information to the second network element in the above step 202, which will not be repeated here.

[0245] Step 513: The L-SMF network element sends the sixth information to the L-PSA UPF network element. Correspondingly, the L-PSA UPF network element receives the sixth information from the L-SMF network element.

[0246] For example, the sixth information may be an N4 session creation request.

[0247] Optionally, the relevant implementation process of step 513 can refer to the relevant implementation process of the second network element sending the sixth information to the sixth network element in the above step 202, which will not be repeated here.

[0248] Step 514: The L-PSA UPF network element sends the seventh information to the L-SMF network element. Correspondingly, the L-SMF network element receives the seventh information from the L-PSA UPF network element.

[0249] For example, the seventh information may be a session creation response.

[0250] Optionally, the relevant implementation process of step 514 can refer to the relevant implementation process of the sixth network element sending the seventh information to the second network element in the above step 202, which will not be repeated here.

[0251] Step 515: The L-SMF network element sends the second information to the SMF network element. Correspondingly, the SMF network element receives the second information from the L-SMF network element.

[0252] Optionally, the relevant implementation process of step 515 can refer to the relevant implementation process of the second network element sending the second information to the first network element in the above step 202, which will not be repeated here.

[0253] Step 516: The SMF network element sends the third information to the UL CL UPF network element. Correspondingly, the UL CL UPF network element receives the third information from the SMF network element.

[0254] Optionally, the relevant implementation process of step 516 can refer to the relevant implementation process of the first network element sending the third information to the third network element in the above step 202, which will not be repeated here.

[0255] Step 517: The SMF network element sends the eleventh message to the L-SMF network element. Correspondingly, the L-SMF network element receives the eleventh message from the SMF network element.

[0256] In an embodiment of the present application, when the SMF network element sends the eleventh message to the L-SMF network element, the user plane tunnel for transmitting local service data is established. For example, the eleventh message may be a session creation completion response. The ninth message may be used to indicate that the session creation is complete. Optionally, the SMF network element may also send a session creation completion response to the AMF network element.

[0257] Optionally, when the above steps 504 to 506 are executed or the above steps 507 to 508 are executed, the SMF network element also needs to send a session creation completion response to the EASDF network element.

[0258] Optionally, when step 509 is executed, the EASDF network element needs to send a DNS request response message to the UE, wherein the DNS request response message is used to indicate that the user plane tunnel required for transmitting local service data is established and the user can start local services.

[0259] It can be seen from the above steps 501 to 517 that the SMF network element can select the user plane network element it manages as the UL CL UPF network element for the UE based on the diversion policy or addressing policy corresponding to the local service provided by the L-SMF network element, and can configure the diversion policy for the UL CL UPF network element. In this way, through this method, the centralized SMF network element is not aware of the deployment of user plane network elements and applications within the domain (or can be understood as local), nor is it aware of the policy generation method for the user's service within the domain, which can effectively reduce the management complexity of the centralized SMF network element and other centralized control plane network elements. In addition, this method can be implemented when the L-SMF network element has the function of configuring the EASDF network element, and the L-SMF network element completes the corresponding configuration of the EASDF network element, which can effectively reduce the complexity of the centralized control plane in managing local services. This method can also be implemented when the L-SMF network element does not have the function of configuring the EASDF network element, and the SMF network element completes the corresponding configuration of the EASDF network element.

[0260] It can be understood that compared with the existing technology, the communication solution provided by the above steps 501 to 517 is that the L-SMF network element performs user plane management and user policy management within the domain, which can avoid direct management of the centralized control plane, so that when user services (which can be understood as local services) are deployed / activated / changed within the domain, the centralized control plane may not perceive the deployment / activation / change of local service policies or local service logic, thereby effectively reducing the management complexity of the centralized control plane.

[0261] It should be noted that in the description of this application, "at least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC. And, unless otherwise specified, the ordinal numbers such as "first", "second", and "third" mentioned in the embodiments of this application are used to distinguish multiple objects and are not used to limit the order, timing, priority or importance of multiple objects. In addition, the terms "including", "comprising", "having" and their variations appearing in this application all mean "including but not limited to" unless otherwise specifically emphasized.

[0262] In addition, it should be noted that each step involved in the above embodiments can be performed by a corresponding device, or by a component such as a chip, processor, or chip system within the device, and the embodiments of the present application do not limit this. The above embodiments are described only as examples of execution by corresponding devices.

[0263] It should be noted that in each of the above embodiments, some steps may be selected for implementation, and the order of the steps in the diagrams may be adjusted for implementation, and this application does not limit this. It should be understood that executing some of the steps in the diagrams, adjusting the order of the steps, or combining them for specific implementation all fall within the scope of protection of this application.

[0264] It is understandable that in order to implement the functions in the above embodiments, the various devices involved in the above embodiments include hardware structures and / or software modules corresponding to the execution of each function. It should be readily apparent to those skilled in the art that, in combination with the units and method steps of the various examples described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0265] It should be understood that the "steps" in the embodiments of this application are merely illustrative, a method of expression used to better understand the embodiments, and do not constitute a substantive limitation on the implementation of the solutions of this application. For example, the "steps" can also be understood as "features." Furthermore, the steps do not constitute any limitation on the execution order of the solutions of this application. Any changes in the order of steps, or any operations such as step merging or step splitting that do not affect the implementation of the overall solution, resulting in new technical solutions, are also within the scope of this application.

[0266] The following is a schematic diagram of the structure of possible communication devices provided in embodiments of the present application. These communication devices can be used to implement the functions of the first network element, the second network element, the third network element, the fourth network element, the fifth network element, the sixth network element, the seventh network element, the eighth network element, the access network device, or the terminal device in the above-mentioned method embodiments, thereby also achieving the beneficial effects of the above-mentioned method embodiments.

[0267] As shown in FIG6 , a communication device 600 includes a transceiver module 601 (or a communication module, a transceiver unit, or a communication unit, for sending and receiving data) and a processing module 602 (or a processing unit). The communication device 600 is used to implement the functions of the first network element, the second network element, the third network element, the fourth network element, the fifth network element, the sixth network element, the seventh network element, the eighth network element, the access network device, or the terminal device in the method embodiments shown in FIG2 , FIG4 , or FIG5 .

[0268] Optionally, the transceiver module 601 may include a receiving module and / or a transmitting module. The receiving module may be used by the communication device 600 to receive signals (information or data, etc.); the transmitting module may be used by the communication device 600 to transmit signals (information or data, etc.). The transmitting module may transmit signals (information or data, etc.) under the control of the processing module 602, and the receiving module may receive signals (information or data, etc.) under the control of the processing module 602.

[0269] When the communication device 600 is used to implement the function of the first network element (such as an SMF network element) in the method embodiment shown in Figure 2 or Figure 4 or Figure 5 above: the transceiver module 601 is used to receive a first message from the second network element. The first message includes a policy for terminal equipment to access local services; the second network element is used to manage local user plane function network elements. The transceiver module 601 is also used to send a second message to a third network element. The second message is used to configure a diversion policy corresponding to the local service, and the diversion policy is determined according to the policy for terminal equipment to access local services. The processing module 602 is used to perform corresponding processing operations, such as determining a third network element based on the diversion policy.

[0270] When the communication device 600 is used to implement the functions of the second network element (e.g., an L-SMF network element) in the method embodiments shown in FIG. 2 , FIG. 4 , or FIG. 5 , the transceiver module 601 is configured to send a first message to the first network element. The first message includes a policy for a terminal device to access local services. The processing module 602 is configured to perform corresponding processing operations, such as selecting a fifth network element.

[0271] When the communication device 600 is used to implement the functions of the third network element (e.g., UL CL UPF network element) in the method embodiments shown in FIG. 2 , FIG. 4 , or FIG. 5 , the transceiver module 601 is configured to receive a second message from the first network element. The second message is used to configure a diversion policy for terminal devices accessing local services. The processing module 602 is configured to perform corresponding processing operations, such as diverting edge traffic on a PDU session to a local EAS.

[0272] Among them, when the communication device 600 is used to implement the function of the first network element or the second network element or the third network element or the fourth network element or the fifth network element or the sixth network element or the seventh network element or the eighth network element or the access network device or the terminal device in the method embodiment shown in Figure 2 or Figure 4 or Figure 5, for a more detailed description of the transceiver module 601 and the processing module 602, please refer to the relevant description of the first network element or the second network element or the third network element or the fourth network element or the fifth network element or the sixth network element or the seventh network element or the eighth network element or the access network device or the terminal device in the method embodiment shown in Figure 2 or Figure 4 or Figure 5, which will not be repeated here.

[0273] It should be understood that the transceiver module 601 in the embodiment of the present application can be implemented by a communication interface or a communication interface related circuit component, and the processing module 602 can be implemented by a processor or a processor related circuit component.

[0274] It should be noted that the division of modules in the embodiments of the present application is illustrative and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0275] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, or a server, etc.) or a processor to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0276] As another possible product form, as shown in FIG7 , a communication device 700 includes: a communication interface 701 and a processor 702. Optionally, the communication device 700 further includes a memory 703. The communication interface 701, the processor 702, and the memory 703 are interconnected. When the communication device 700 is used to implement the technical solutions involved in the first network element (or the second network element, or the third network element, or the fourth network element, or the fifth network element, or the sixth network element, or the seventh network element, or the eighth network element, or the access network device, or the terminal device) in the above embodiments, the communication interface 701 may be used to implement the functions of the transceiver module 601 when executing the technical solutions involved in the first network element (or the second network element, or the third network element, or the fourth network element, or the fifth network element, or the sixth network element, or the seventh network element, or the eighth network element, or the access network device, or the terminal device), and the processor 702 may be used to implement the functions of the processing module 602 when executing the technical solutions involved in the first network element (or the second network element, or the third network element, or the fourth network element, or the fifth network element, or the sixth network element, or the seventh network element, or the eighth network element, or the access network device, or the terminal device).

[0277] Optionally, communication interface 701, processor 702, and memory 703 are interconnected via bus 704. Bus 704 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. Buses can be categorized as address buses, data buses, control buses, and the like. For ease of illustration, FIG7 shows only one thick line, but this does not imply that there is only one bus or only one type of bus.

[0278] The communication interface 701 is used to receive and send data. For example, when the communication device 700 is a terminal device (such as a UE) as shown in Figure 1a (or Figure 1b), the communication interface 701 can communicate with the access network device (such as a RAN device) as shown in Figure 1a (or Figure 1b), or can also communicate with other devices (such as other terminal devices) outside the communication system architecture shown in Figure 1a (or Figure 1b). In one example, the communication interface can be a transceiver device with an integrated data transceiver function. In another example, the communication interface can also be composed of a transmitter and a receiver, wherein the transmitter is used to send data and the receiver is used to receive data.

[0279] Optionally, the communication interface 701 may include a transmitter and / or a receiver. The transmitter is used to transmit signals, messages, information, or data. The receiver is used to receive signals, messages, information, or data. For example, the transmitter transmits signals, messages, information, or data under the control of the processor 702. The receiver receives signals, messages, information, or data under the control of the processor 702.

[0280] The functions of processor 702 can refer to the descriptions of the corresponding functions involved in the first, second, third, fourth, fifth, sixth, seventh, eighth network elements, access network devices, or terminal devices in the above embodiments, and will not be repeated here. Processor 702 can be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP, etc. Processor 702 can further include a hardware chip. The hardware chip can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. When implementing the above functions, processor 702 can be implemented through hardware, or alternatively, hardware can execute corresponding software implementations.

[0281] Memory 703 is used to store program instructions, etc. Specifically, the program instructions may include program code, which includes computer operating instructions. Memory 703 may include random access memory (RAM) and may also include non-volatile memory (non-volatile memory), such as at least one disk storage. Processor 702 executes the program instructions stored in memory 703 to implement the above functions, thereby implementing the method steps required to be executed by the first network element, the second network element, the third network element, the fourth network element, the fifth network element, the sixth network element, the seventh network element, the eighth network element, the access network device, or the terminal device in the above embodiments.

[0282] Based on the same concept, an embodiment of the present application further provides a communication system, comprising multiple communication devices (e.g., multiple of a first network element, a second network element, a third network element, a fourth network element, a fifth network element, a sixth network element, a seventh network element, an eighth network element, an access network device, or a terminal device). The first network element can be used to implement the technical solution involved in the first network element in the above embodiment. The second network element can be used to implement the technical solution involved in the second network element in the above embodiment. The third network element can be used to implement the technical solution involved in the third network element in the above embodiment. The fourth network element can be used to implement the technical solution involved in the fourth network element in the above embodiment. The fifth network element can be used to implement the technical solution involved in the fifth network element in the above embodiment. The sixth network element can be used to implement the technical solution involved in the sixth network element in the above embodiment. The seventh network element can be used to implement the technical solution involved in the seventh network element in the above embodiment. The eighth network element can be used to implement the technical solution involved in the eighth network element in the above embodiment. The access network device can be used to implement the technical solution involved in the access network device in the above embodiment. The terminal device can be used to implement the technical solution involved in the terminal device in the above embodiment.

[0283] Based on the same concept, an embodiment of the present application further provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are run on a computer, the computer executes the method provided in the above embodiment.

[0284] Based on the same concept, an embodiment of the present application also provides a computer-readable storage medium, which stores a computer program or instruction. When the computer program or instruction is executed by a computer, the computer executes the method provided in the above embodiment.

[0285] The storage medium may be any available medium that can be accessed by a computer. By way of example and not limitation, computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer.

[0286] Based on the same concept, an embodiment of the present application further provides a chip, which may include a processor and a memory (or the chip is coupled to the memory), and the chip executes program instructions in the memory to perform the method provided in the above embodiment. Wherein, "coupling" refers to the direct or indirect connection between two components, such as coupling can refer to the electrical connection between two components.

[0287] Based on the same concept, an embodiment of the present application also provides a chip system, which includes a processor for supporting a computer device to implement the functions involved in the communication device (such as the first network element or the second network element or the third network element or the fourth network element or the fifth network element or the sixth network element or the seventh network element or the eighth network element or the access network device or the terminal device) in the above embodiment. In one possible implementation, the chip system also includes a memory, which is used to store the necessary programs and data for the computer device. The chip system can be composed of chips, or it can include chips and other discrete devices.

[0288] The methods provided in the embodiments of the present application can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, they can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the process or function described in the embodiments of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state drive (SSD)).

[0289] The steps of the methods described in the embodiments of the present application can be directly embedded in hardware, software units executed by a processor, or a combination of the two. The software units can be stored in RAM, ROM, EEPROM, registers, hard disks, removable disks, CD-ROMs, or other storage media in any form known in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Alternatively, the storage medium can also be integrated into the processor. The processor and storage medium can be arranged in an ASIC.

[0290] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or box in the flow chart and / or block diagram, as well as the combination of the flow chart and / or box in the flow chart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flow charts and / or one or more boxes in the block diagram.

[0291] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0292] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: Applied to a first network element, the method includes: receiving a first message from a second network element, the first message including a policy for a terminal device to access a local service; the second network element is used to manage a local user plane function network element; A second message is sent to a third network element, where the second message is used to configure a diversion strategy corresponding to the local service, and the diversion strategy is determined according to the strategy.

2. The method according to claim 1, wherein When the policy includes the diversion policy, the second message includes the diversion policy; or, When the policy does not include the diversion policy, the diversion policy is created according to the policy.

3. The method according to claim 1 or 2, wherein: Before receiving the first message from the second network element, the method further includes: receiving session information of the terminal device from a fourth network element, where the session information of the terminal device includes information of the second network element; A third message is sent to the second network element according to the information of the second network element, where the third message is used to obtain the policy.

4. The method according to claim 3, wherein Before receiving the session information of the terminal device from the fourth network element, the method further includes: A first subscription message is sent to the fourth network element, where the first subscription message is used to subscribe to the session information of the terminal device.

5. The method according to any one of claims 1 to 4, characterized in that The method further comprises: If the policy does not include the addressing policy corresponding to the local service, and the fifth network element is not selected for the session of the terminal device, selecting the fifth network element for the session of the terminal device; Sending a fourth message to the fifth network element, where the fourth message is used to configure an addressing policy corresponding to the local service, where the addressing policy is generated according to the policy; The address information of the fifth network element is sent to the terminal device, and the address information is used by the terminal device to perform domain name query subsequently.

6. The method according to claim 5, wherein The method further comprises: receiving a fifth message from the fifth network element, where the fifth message includes address information of the first application server, where the address information of the first application server is obtained based on a domain name query initiated by the terminal device; The third network element is determined according to the fifth message.

7. The method according to any one of claims 1 to 4, characterized in that The method further comprises: If the strategy includes the diversion strategy, the third network element is determined according to the diversion strategy.

8. The method according to any one of claims 1 to 7, wherein: The method further comprises: Sending first information to the second network element, where the first information is used to request allocation of an uplink tunnel identifier of a sixth network element, the first information including the downlink tunnel identifier of the third network element, and the sixth network element is a local user plane function network element; receiving second information from the second network element, where the second information includes an uplink tunnel identifier of the sixth network element; Sending third information to the third network element, where the third information includes an uplink tunnel identifier of the sixth network element; The downlink tunnel identifier of the third network element and the uplink tunnel identifier of the sixth network element are used to establish a first user plane tunnel corresponding to the local service between the third network element and the sixth network element.

9. The method according to any one of claims 1 to 8, wherein The method further comprises: Sending fourth information to the third network element, where the fourth information includes a downlink tunnel identifier of an access network device; receiving fifth information from the third network element; If the fifth information includes the updated uplink tunnel identifier of the third network element, sending the updated uplink tunnel identifier to the access network device; The downlink tunnel identifier of the access network device and the updated uplink tunnel identifier are used to establish a second user plane tunnel corresponding to the local service between the access network device and the third network element.

10. A communication method, characterized in that: Applied to a second network element, the method includes: Sending a first message to a first network element, where the first message includes a policy for a terminal device to access a local service; The second network element is used to manage the local user plane function network element.

11. The method according to claim 10, wherein Before sending the first message to the first network element, the method further includes: A third message is received from the first network element, where the third message is used to obtain the policy.

12. The method according to claim 10 or 11, wherein: The method further comprises: Select the fifth network element; Sending a sixth message to the fifth network element, where the sixth message is used to configure an addressing policy corresponding to the local service, where the addressing policy is included in the policy; A seventh message is sent to the first network element, where the seventh message includes identification information and / or address information of the fifth network element, and the identification information and / or address information of the fifth network element is used to establish a communication connection between the first network element and the fifth network element.

13. The method according to any one of claims 10 to 12, wherein: The method further comprises: receiving first information from the first network element, the first information being used to request allocation of an uplink tunnel identifier of a sixth network element, the first information including a downlink tunnel identifier of a third network element, and the sixth network element being a local user plane function network element; Sending sixth information to the sixth network element, where the sixth information is used to request allocation of an uplink tunnel identifier of the sixth network element, and the sixth information includes the downlink tunnel identifier of the third network element; receiving seventh information from the sixth network element, where the seventh information includes an uplink tunnel identifier of the sixth network element; Sending second information to the first network element, where the second information includes an uplink tunnel identifier of the sixth network element; The downlink tunnel identifier of the third network element and the uplink tunnel identifier of the sixth network element are used to establish a first user plane tunnel corresponding to the local service between the third network element and the sixth network element.

14. The method according to any one of claims 10 to 13, wherein: Sending a first message to a first network element includes: Sending a second subscription message to the fourth network element, where the second subscription message is used to subscribe to the session information of the terminal device; receiving session information of the terminal device from the fourth network element, where the session information of the terminal device includes information of the first network element used to provide services for the terminal device; Send the first message to the first network element according to the information of the first network element.

15. The method according to any one of claims 10 to 13, wherein: The method further comprises: An eighth message is sent to the fourth network element, where the eighth message includes information about the second network element and identification information of the terminal device, and is used to trigger establishment of a communication connection between the second network element and the first network element.

16. A communication method, characterized in that: Applied to a third network element, the method includes: A second message is received from the first network element, where the second message is used to configure a diversion strategy for a terminal device to access local services.

17. The method according to claim 16, wherein The method further comprises: receiving third information from the first network element, where the third information includes an uplink tunnel identifier of a sixth network element; The downlink tunnel identifier of the third network element and the uplink tunnel identifier of the sixth network element are used to establish a first user plane tunnel corresponding to the local service between the third network element and the sixth network element.

18. The method according to claim 16 or 17, wherein: The method further comprises: receiving fourth information from the first network element, where the fourth information includes a downlink tunnel identifier of an access network device; Sending fifth information to the first network element, where the fifth information includes the uplink tunnel identifier of the third network element or the updated uplink tunnel identifier of the third network element; The downlink tunnel identifier of the access network device and the uplink tunnel identifier of the third network element or the updated uplink tunnel identifier of the third network element are used to establish a second user plane tunnel corresponding to the local service between the access network device and the third network element.

19. A communication device, characterized in that: The method comprises a module or unit for executing the method according to any one of claims 1 to 9, or a module or unit for executing the method according to any one of claims 10 to 15, or a module or unit for executing the method according to any one of claims 16 to 18.

20. A communication device, characterized in that: include: Communication interface for receiving and sending data; Memory for storing computer program instructions and data; A processor, configured to execute and call computer program instructions and data in the memory, so that the communication device performs the method according to any one of claims 1 to 9, the method according to any one of claims 10 to 15, or the method according to any one of claims 16 to 18.

21. A communication system, characterized in that: including a first network element, a second network element and a third network element; The first network element is configured to perform the method according to any one of claims 1 to 9; The second network element is configured to perform the method according to any one of claims 10 to 15; The third network element is used to execute the method according to any one of claims 16 to 18.

22. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program or instructions. When the computer program or instructions are executed by a computer, the computer executes the method according to any one of claims 1 to 9, the method according to any one of claims 10 to 15, or the method according to any one of claims 16 to 18.

23. A computer program product, characterized in that The computer program product comprises a computer program or instructions, which, when executed on a computer, causes the computer to perform the method according to any one of claims 1 to 9, or the method according to any one of claims 10 to 15, or the method according to any one of claims 16 to 18.

24. A chip, characterized in that: The chip includes a processor, and the chip is used to execute program instructions in the memory to perform the method according to any one of claims 1 to 9, or the method according to any one of claims 10 to 15, or the method according to any one of claims 16 to 18.

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