Method and apparatus for communicating

Abstract

The application provides a method and device for communication. The method can include: a session management network element in a home network receiving first information corresponding to a terminal device from a session management network element in a visited network, the first information being used to indicate a deployment position of an edge application server (EAS) in the visited network; and the session management network element in the home network obtaining EAS deployment information corresponding to the first information according to the first information. In the application, the VPLMN opens the EAS deployment information of the VPLMN to the HPLMN, thereby realizing discovery of the EAS in the VPLMN in the HR roaming scenario.

Description

Technical Field

[0001] This application relates to the field of communications, and more specifically, to a method and apparatus for communication. Background Technology

[0002] In edge computing (EC) deployment scenarios, certain services may be provided by multiple edge application servers (EAS) deployed at the network edge. These multiple EASs can provide the same services and content, and most of them have different Internet Protocol (IP) addresses. When user equipment (UE) requests access to this service, EC scenarios require it to connect to an available EAS located closest to the UE. Therefore, the appropriate IP address of the EAS is quite important.

[0003] In some cases, a UE may leave the coverage area of ​​its home public land mobile network (PLMN) (HPLMN) and access a visited public land mobile network (VPLMN) via home routed (HR) roaming, with the VPLMN providing services to the UE. Summary of the Invention

[0004] This application provides a communication method and apparatus that opens the VPLMN's EAS deployment information to the HPLMN through the VPLMN, thereby enabling the discovery of EAS in the VPLMN during HR roaming scenarios.

[0005] Firstly, a communication method is provided, which can be executed by a session management network element, or by a component of the session management network element (such as a chip or circuit), without limitation. For ease of description, the following description takes execution by a session management network element in the home network as an example.

[0006] The method may include: a session management network element in the home network receiving first information corresponding to a terminal device from a session management network element in the visited network, the first information being used to indicate the deployment location of the edge application server (EAS) in the visited network; and the session management network element in the home network obtaining EAS deployment information corresponding to the first information based on the first information.

[0007] For example, the session management element in the home network and the session management element in the visited network serve the session of the terminal device. For example, the session type of the terminal device is HR type.

[0008] The first information corresponding to the terminal device can be understood as the first information being determined based on the terminal device.

[0009] Based on the above technical solution, the session management element in the home network receives first information corresponding to the terminal device from the session management element in the visited network. This first information can be used to indicate the deployment location of the EAS in the visited network. The session management element in the home network then obtains the EAS deployment information corresponding to this first information. In this way, the session management element in the home network can determine which locations in the visited network contain edge application servers that the terminal device may access (or can access). When the terminal device accesses the visited network via HR roaming, because the session management element in the home network knows which locations in the visited network contain edge application servers that the terminal device may access (or can access), it can assist the terminal device in accessing edge application services in the visited network, improving the success rate of the terminal device accessing edge application services in the visited network, and realizing the discovery of the local EAS (i.e., the EAS in VPLMN) in the HR roaming scenario. Furthermore, the session management network element in the home network receives the first information corresponding to the terminal device. Therefore, the session management network element in the home network does not need to receive the first information corresponding to other terminal devices (such as terminal devices not served by the session management network element in the home network). This not only reduces the signaling overhead caused by transmitting the first information, but also improves the security of EAS deployment information sent to the session management network element in the home network.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the first information corresponding to the terminal device includes: the first information is determined based on the location of the terminal device.

[0011] Based on the above technical solution, the session management network element in the home network can determine the first information corresponding to the terminal device based on the location of the terminal device. In this way, by considering the location of the terminal device, it can avoid the session management network element in the visited network sending some first information that the terminal device does not need to the session management network element in the home network (such as the deployment location of the EAS indicated by the first information, which is an EAS deployment location that the terminal device is almost impossible to access), or avoid sending other terminal device-related first information to the session management network element in the home network. This not only assists the terminal device in accessing edge application services in the visited network, but also saves signaling overhead and improves the security of EAS deployment information sent to the session management network element in the home network.

[0012] In conjunction with the first aspect, in some implementations of the first aspect, the first information is determined based on the location of the terminal device, including: the first information is used to indicate: among the deployment locations of EAS determined based on the location of the terminal device, the deployment locations of EAS that the terminal device is allowed to access.

[0013] Based on the above technical solution, the first information corresponding to the terminal device is used to indicate the EAS deployment location that the terminal device is allowed to access, among the EAS deployment locations determined according to the location of the terminal device. This not only considers the location of the terminal device, thereby saving signaling overhead and improving the security of EAS deployment information sent to the session management network element in the home network, but also considers the authorization status of the visited network (such as providing the session management network element in the home network with the first information allowing access to the visited network), thus taking into account the requirements of the visited network itself and improving network security.

[0014] In conjunction with the first aspect, in some implementations of the first aspect, the session management network element in the home network obtains the EAS deployment information corresponding to the first information based on the first information, including: the session management network element in the home network sending a request message to the data management network element in the visited network, the request message including the first information, the request message being used to request the acquisition of the EAS deployment information corresponding to the first information; the session management network element in the home network receiving the EAS deployment information corresponding to the first information from the data management network element in the visited network.

[0015] Based on the above technical solution, the session management network element in the home network can obtain the EAS deployment information corresponding to the first information from the data management network element in the visited network. This not only enables the session management network element in the home network to obtain the EAS deployment information corresponding to the first information, but also allows the data management network element in the visited network to store the EAS deployment information corresponding to the first information, resulting in high security. For example, the session management network element in the home network can request the EAS deployment information corresponding to the first information from the data management network element in the visited network through network open network elements (such as network open network elements in the home network and network open network elements in the visited network).

[0016] In conjunction with the first aspect, in some implementations of the first aspect, the session management network element in the home network obtains the EAS deployment information corresponding to the first information based on the first information, including: the session management network element in the home network sending a request message to the data management network element in the home network, the request message including the first information, the request message being used to request the acquisition of the EAS deployment information corresponding to the first information; and the session management network element in the home network receiving the EAS deployment information corresponding to the first information from the data management network element in the home network.

[0017] Based on the above technical solution, the session management network element in the home network can obtain the EAS deployment information corresponding to the first information from the data management network element in the home network. In this way, the data management network element in the home network can store the EAS deployment information corresponding to the first information, allowing the session management network element in the home network to quickly obtain the EAS deployment information directly from other network elements in the home network, thus saving signaling overhead. For example, the session management network element in the home network can request the EAS deployment information corresponding to the first information from the data management network element in the home network through the network open network element in the home network.

[0018] In conjunction with the first aspect, in some implementations of the first aspect, the request message also includes an identifier of the network to be visited.

[0019] Based on the above technical solution, when a session management network element in the home network requests EAS deployment information corresponding to the first information, it can carry the identifier of the visited network, which facilitates the identification of the visited network or the network element in the visited network, and to know which visited network's EAS deployment information is being requested.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the session management network element in the home network determines the Domain Name System (DNS) processing rules based on the EAS deployment information corresponding to the first information, and the DNS processing rules are used to process DNS messages.

[0021] Based on the above technical solution, the session management network element in the home network determines the DNS processing rules according to the EAS deployment information corresponding to the first information, and the DNS processing rules can be used to process DNS messages.

[0022] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the session management element in the home network receiving the identifier of the visited network from the session management element in the visited network.

[0023] Based on the above technical solution, the session management network element in the home network can also receive the identifier of the visited network from the session management network element in the visited network. The identifier of the visited network and the first information can be carried in the same signaling or in different signaling, without restriction.

[0024] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the session management network element in the home network receiving the IP address and / or domain name corresponding to the EAS from the edge application server discovery network element, wherein the IP address corresponding to the EAS is the IP address of the EAS accessed by the terminal device in the visited network, and the domain name corresponding to the EAS is the domain name of the EAS accessed by the terminal device in the visited network; the session management network element in the home network sending the IP address and / or domain name corresponding to the EAS to the session management network element in the visited network.

[0025] Based on the above technical solution, the session management element in the home network sends the IP address and / or domain name corresponding to the EAS to the session management element in the visited network, thereby triggering the session management element in the visited network to perform traffic redirection for the sessions of terminal devices roaming to the visited network.

[0026] Secondly, a communication method is provided, which can be executed by a session management network element, or by a component of the session management network element (such as a chip or circuit), without limitation. For ease of description, the following description takes execution by a session management network element in a visited network as an example.

[0027] The method may include: a session management network element in the visited network determining first information corresponding to the terminal device based on the location of the terminal device, the first information being used to indicate the deployment location of the edge application server (EAS) in the visited network; and the session management network element in the visited network sending the first information to a session management network element in the home network.

[0028] Based on the above technical solution, the session management element in the visited network sends first information corresponding to the terminal device to the session management element in the home network. This first information can be used to indicate the deployment location of the EAS in the visited network. Since the session management element in the visited network sends the first information corresponding to the terminal device to the session management element in the home network, it does not need to send the first information corresponding to other terminal devices (such as terminal devices not served by the session management element in the home network) to the session management element in the home network. This not only reduces the signaling overhead of transmitting the first information but also improves the security of the EAS deployment information sent to the session management element in the home network. Furthermore, by sending the first information to the session management element in the home network, the session management element in the home network can obtain the corresponding EAS deployment information based on the first information if needed. Therefore, the session management element in the home network can determine which locations in the visited network contain edge application servers that the terminal device may access (or can access) based on the obtained EAS deployment information corresponding to the first information. When a terminal device accesses the visited network via HR roaming, the session management network element in the home network learns which locations in the visited network contain edge application servers that the terminal device may access (or can access). Therefore, it can assist the terminal device in accessing edge application services in the visited network, improve the success rate of the terminal device accessing edge application services in the visited network, and realize the discovery of local EAS in the HR roaming scenario.

[0029] In conjunction with the second aspect, in some implementations of the second aspect, the first information is used to obtain the EAS deployment information corresponding to the first information.

[0030] Based on the above technical solution, the session management network element in the home network can obtain the EAS deployment information corresponding to the first information. Therefore, the session management network element in the home network can, based on the obtained EAS deployment information corresponding to the first information, determine which locations in the visited network have edge application servers deployed, thereby assisting terminal devices in accessing edge application services in the visited network and realizing the discovery of local EAS in HR roaming scenarios.

[0031] In conjunction with the second aspect, in some implementations of the second aspect, the first information is used to indicate: among the deployment locations of EAS determined based on the location of the terminal device, the deployment locations of EAS that the terminal device is allowed to access; the session management network element in the visited network determines the first information corresponding to the terminal device based on the location of the terminal device, including: the session management network element in the visited network determines the first information corresponding to the terminal device based on the location of the terminal device and policy information, wherein the policy information is used to indicate the deployment locations of EAS that the visited network is allowed to send to the home network.

[0032] In conjunction with the second aspect, in some implementations of the second aspect, the first information is used to indicate: the deployment location of EAS that the terminal device is allowed to access, among the deployment locations of EAS determined according to the location of the terminal device; the session management network element in the visited network determines the first information corresponding to the terminal device according to the location of the terminal device, including: the session management network element in the visited network determines the second information corresponding to the terminal device according to the location of the terminal device; the session management network element in the visited network sends a request message to the policy control network element in the visited network, the request message including the second information, the request message being used to request permission for the visited network to send the deployment location of the EAS to the home network; the session management network element in the visited network receives the first information from the policy control network element in the visited network, the first information being determined based on the second information.

[0033] The second information and the first information can be the same, or the first information can be a subset of the second information.

[0034] For example, the request message includes the identifier of the home network.

[0035] In conjunction with the second aspect, in some implementations of the second aspect, the method further includes: the session management element in the visited network sending the identifier of the visited network to the session management element in the home network.

[0036] The benefits of the second aspect and various possible designs can be found in the description of the first aspect, and will not be repeated here.

[0037] Thirdly, a communication method is provided, which can be executed by a data management network element, or by a component of the data management network element (such as a chip or circuit), without limitation. For ease of description, the following explanation will take execution by a data management network element in the home network as an example.

[0038] The method may include: a data management network element in the home network receiving a request message from a session management network element in the home network, the request message including first information corresponding to the terminal device, the first information being used to indicate the deployment location of the edge application server (EAS) in the visited network, the request message being used to request the EAS deployment information corresponding to the first information; and the data management network element in the home network sending the EAS deployment information corresponding to the first information to the session management network element in the home network.

[0039] Based on the above technical solution, the session management network element in the home network can obtain the EAS deployment information corresponding to the first information from the data management network element in the home network. In this way, the data management network element in the home network can store (or manage, or be able to retrieve) the EAS deployment information corresponding to the first information. Consequently, the session management network element in the home network can quickly obtain the EAS deployment information corresponding to the first information directly from the network element in the home network, saving signaling overhead. For example, the session management network element in the home network can request the EAS deployment information corresponding to the first information from the data management network element in the home network through the network open network element in the home network.

[0040] In conjunction with the third aspect, in some implementations of the third aspect, the request message also includes the identifier of the visited network, and the method further includes: the data management network element in the home network determines the EAS deployment information corresponding to the first information based on the identifier of the visited network and the first information.

[0041] Based on the above technical solution, when a session management network element in the home network requests EAS deployment information corresponding to the first information, it can carry the identifier of the visited network, which facilitates the identification of the visited network or the network element in the visited network, and to know which visited network's EAS deployment information is being requested.

[0042] In conjunction with the third aspect, in some implementations of the third aspect, the method also includes: the data management network element in the home network locally stores the EAS deployment information corresponding to the first information.

[0043] Based on the above technical solution, the data management network element in the home network can store the EAS deployment information corresponding to the first information, so that the session management network element in the home network can quickly obtain the EAS deployment information corresponding to the first information directly from the network element in the home network.

[0044] Fourthly, a communication method is provided, which can be executed by a core network element or by a component of the core network element (such as a chip or circuit). There is no limitation on this. For ease of description, the following example illustrates the method executed by a policy control element in the visited network.

[0045] The method may include: a policy control network element in the visited network receiving a request message from a session management network element in the visited network, the request message including second information corresponding to the terminal device, the request message being used to request permission for the visited network to send the deployment location of the EAS to the home network; the policy control network element in the visited network determining first information corresponding to the terminal device based on the second information; and the policy control network element in the visited network sending the first information from the policy control network element in the visited network to the session management network element in the visited network.

[0046] Based on the above technical solution, the session management element in the visited network can determine the second information corresponding to the terminal device and query (or request, or query) the policy control element in the visited network for the first information corresponding to the terminal device. The policy control element in the visited network can then determine the first information based on the second information (e.g., the second information is the same as the first information, or the first information is a subset of the second information). This approach not only considers the location of the terminal device, thus saving signaling overhead and improving the security of EAS deployment information, but also takes into account the authorization status of the visited network, thereby meeting the requirements of the visited network itself and improving network security. Furthermore, the session management element in the visited network can dynamically send requests for the first information to the policy control element in the visited network according to actual conditions, making the solution flexible.

[0047] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the first information is used to obtain the EAS deployment information corresponding to the first information.

[0048] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the first information is used to indicate: among the deployment locations of EAS determined based on the location of the terminal device, the deployment locations of EAS that the terminal device is allowed to access.

[0049] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the request message includes the identifier of the home network.

[0050] Fifthly, a communication apparatus is provided for performing the method in any of the possible implementations of the first to fourth aspects described above. Specifically, the apparatus may include units and / or modules for performing the method in any of the possible implementations of the first to fourth aspects, such as processing units and / or communication units.

[0051] In one implementation, the device is a core network element (such as a session management element, a data management element, a network openness element, or a policy control element). When the device is a core network element, the communication unit can be a transceiver or an input / output interface; the processing unit can be at least one processor. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0052] In another implementation, the device is a chip, chip system, or circuit used in core network elements (such as session management elements, data management elements, network openness elements, and policy control elements). When the device is a chip, chip system, or circuit used in core network elements, the communication unit can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; the processing unit can be at least one processor, processing circuit, or logic circuit.

[0053] A sixth aspect provides a communication apparatus, the apparatus comprising: at least one processor for executing a computer program or instructions stored in a memory to perform the method in any of the possible implementations of the first to fourth aspects described above. Optionally, the apparatus further comprises a memory for storing the computer program or instructions. Optionally, the apparatus further comprises a communication interface through which the processor reads the computer program or instructions stored in the memory.

[0054] In one implementation, the device is a core network element (such as a session management network element, a data management network element, a network openness network element, or a policy control network element).

[0055] In another implementation, the device is a chip, chip system, or circuit used for core network elements (such as session management elements, data management elements, network openness elements, and policy control elements).

[0056] In a seventh aspect, this application provides a processor for performing the methods provided in the foregoing aspects.

[0057] Unless otherwise specified, or if it does not contradict its actual function or internal logic in the relevant description, the transmission and acquisition / reception operations involved in the processor can be understood as processor output and reception, input and other operations, or as transmission and reception operations performed by radio frequency circuits and antennas. This application does not limit them in this regard.

[0058] Eighthly, a computer-readable storage medium is provided that stores program code for execution by a device, the program code including methods for performing any of the possible implementations of the first to fourth aspects described above.

[0059] Ninth aspect, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the method in any one of the possible implementations of the first to fourth aspects described above.

[0060] In a tenth aspect, a communication system is provided, comprising one or more of the aforementioned session management network element in the home network, session management network element in the visited network, policy control network element in the visited network, network openness network element in the home network, or data management network element (such as data management network element in the home network, or data management network element in the visited network). Attached Figure Description

[0061] Figure 1 This is a schematic diagram of a network architecture applicable to embodiments of this application.

[0062] Figure 2This is a schematic diagram of another network architecture applicable to embodiments of this application.

[0063] Figure 3 This is a schematic diagram of a communication method 300 provided in an embodiment of this application.

[0064] Figure 4 This is a schematic diagram of the network architecture applicable to Scheme A provided in the embodiments of this application.

[0065] Figure 5 This is a schematic diagram of the network architecture applicable to Scheme B provided in the embodiments of this application.

[0066] Figure 6 This is a schematic diagram of another communication method 600 provided in an embodiment of this application.

[0067] Figure 7 This is a schematic flowchart of a communication method 700 provided in an embodiment of this application.

[0068] Figure 8 This is a schematic flowchart of another communication method 800 provided in an embodiment of this application.

[0069] Figure 9 This is a schematic flowchart of another communication method 900 provided in an embodiment of this application.

[0070] Figure 10 This is a schematic diagram of a communication device 1000 provided in an embodiment of this application.

[0071] Figure 11 This is a schematic diagram of another communication device 1100 provided in an embodiment of this application.

[0072] Figure 12 This is a schematic diagram of a chip system 1200 provided in an embodiment of this application. Detailed Implementation

[0073] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0074] The technical solutions provided in this application can be applied to various communication systems, such as 5th generation (5G) or new radio (NR) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, and LTE time division duplex (TDD) systems. The technical solutions provided in this application can also be applied to future communication systems, such as 6th generation mobile communication systems. Furthermore, the technical solutions provided in this application can also be applied to device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), and Internet of Things (IoT) communication systems or other communication systems.

[0075] First, combine Figure 1 and Figure 2 The network architecture applicable to this application is briefly described below.

[0076] Figure 1 This is a schematic diagram of a network architecture applicable to embodiments of this application. For example... Figure 1 As shown, this network architecture takes home-routed (HR) roaming as an example.

[0077] A cellular mobile communication network of a certain operator and its standard can be called a public land mobile network (PLMN). The PLMN to which a user equipment (UE) is subscribed can be called a home public land mobile network (HPLMN), representing the subscriber's home operator. When a UE leaves the coverage area of ​​an HPLMMN due to movement or other reasons, if a PLMN meets the following conditions: 1) it can cover the UE's current location, and 2) its operator has signed a roaming agreement with the operator of the UE's HPLMMN (a roaming agreement is an agreement between operators, the content of which may include, for example, the services and billing methods provided to subscribers of the other operator's network, etc., which is not limited), then the UE can access that PLMN, and that PLMN can be called a visited public land mobile network (VPLMN). The act of a UE accessing a VPLMN is called roaming. Generally, roaming scenarios can be divided into local breakout (LBO) roaming and home routed (HR) roaming. The main difference between the two lies in whether the session needs to connect to the home network's user plane function (UPF). In HR roaming scenarios, the session (referred to as an HR session) connects to the home network's UPF. An HR session refers to a session established when the user is in the visited network and connected to the home network's UPF. The traffic carried in this HR session is sent from the UE to the home network's UPF and then to the receiving end.

[0078] like Figure 1As shown, the network architecture may include, but is not limited to: network slice specific authentication and authorization function (NSSAAF), network slice selection function (NSSF), authentication server function (AUSF), unified data management (UDM), policy control function (PCF), application function (AF), access and mobility management function (AMF), session management function (SMF), UE, radio access network equipment, UPF, data network (DN), etc.

[0079] The following is about Figure 1 A brief introduction to each network element shown in the diagram is provided.

[0080] 1. UE: can be called terminal equipment, access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user equipment.

[0081] Terminal devices can be devices that provide voice / data to users, such as handheld devices with wireless connectivity, in-vehicle devices, etc. Currently, examples of terminals include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving vehicles, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, wearable devices, terminal devices in 5G networks, or future public land mobile communication networks. Terminal devices in a network (PLMN), etc., are not limited to this in the embodiments of this application.

[0082] By way of example and not limitation, in this embodiment, the terminal device can also be a wearable device. Wearable devices, also known as wearable smart devices, are a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are feature-rich, large in size, and can achieve complete or partial functions without relying on a smartphone, such as smartwatches or smart glasses, as well as those that focus on a specific type of application function and require the use of other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0083] Furthermore, in this embodiment, the terminal device can also be a terminal device in an IoT system. IoT is an important component of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection.

[0084] It should be noted that terminal devices and access network devices can communicate with each other using some air interface technology (such as NR or LTE). Terminal devices can also communicate with each other using some air interface technology (such as NR or LTE).

[0085] In this embodiment, the device for implementing the functions of the terminal device can be the terminal device itself, or it can be a device that supports the terminal device in implementing the functions, such as a chip system or a chip. This device can be installed in the terminal device. In this embodiment, the chip system can be composed of chips, or it can include chips and other discrete devices.

[0086] 2. Radio Access Network (RAN) Equipment: This equipment provides access to a communication network for authorized users in a specific area. Specifically, it can include wireless network equipment in 3GPP (3rd Generation Partnership Project) networks or access points in non-3GPP networks. For ease of description, RAN equipment will be used in the following text.

[0087] AN devices can employ different radio access technologies. Currently, there are two types of radio access technologies: 3GPP access technologies (e.g., those used in 3rd generation (3G), 4th generation (4G), or 5G systems) and non-3GPP access technologies. 3GPP access technologies refer to access technologies that conform to 3GPP standards and specifications. For example, access network equipment in a 5G system is called a next-generation NodeBase station (gNB) or RAN equipment. Non-3GPP access technologies can include air interface technologies such as access points (APs) in Wireless Fidelity (WiFi), Worldwide Interoperability for Microwave Access (WiMAX), and Code Division Multiple Access (CDMA). AN devices can allow terminal devices and the 3GPP core network to interconnect using non-3GPP technologies.

[0088] The AN device is responsible for functions such as radio resource management, quality of service (QoS) management, data compression, and encryption on the air interface side. The AN device provides access services to terminal devices, thereby completing the forwarding of control signals and user data between the terminal devices and the core network.

[0089] AN devices may include, but are not limited to: macro base stations, micro base stations (also known as small stations), radio network controllers (RNCs), Node Bs (NBs), base station controllers (BSCs), base transceiver stations (BTSs), home base stations (e.g., home-evolved Node Bs, or home Node Bs (HNBs)), baseband units (BBUs), access points (APs), wireless relay nodes, wireless backhaul nodes, transmission points (TPs), or transmission and reception points (TRPs) in WiFi systems. They may also be gNBs or transmission points (TRPs or TPs) in 5G (e.g., NR) systems, one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or network nodes constituting gNBs or transmission points, such as distributed units (DUs), or base stations in next-generation 6G communication systems. This application does not limit the specific technology or device form used in the AN devices.

[0090] 3. AMF: Primarily used for access control, mobility management, attach and detach functions.

[0091] 4. SMF: Primarily used for user plane network element selection, user plane network element redirection, Internet Protocol (IP) address allocation for terminal devices, and session management in mobile networks, such as session establishment, modification and release, and Quality of Service (QoS) control.

[0092] In this application, for the purpose of distinction, the SMF in HPLMN is referred to as the home SMF (H-SMF), and the SMF in VPLMN is referred to as the visited SMF (V-SMF).

[0093] 5. UPF: Primarily used for receiving and forwarding user plane data. For example, a UPF can receive user plane data from a DN and send it to the terminal device via an AN device. A UPF can also receive user plane data from the terminal device via an AN device and forward it to the DN. A UPF directly connected to the DN via the N6 interface in a session can be called a Protocol Data Unit (PDU) session anchor (PSA).

[0094] In this application, for distinction, the UPF in the HPLMN is referred to as the home UPF (H-UPF), and the UPF in the VPLMN is referred to as the visited UPF (V-UPF). Furthermore, for distinction, the PSA in the HPLMN is referred to as the home PSA (H-PSA), and the PSA in the VPLMN is referred to as the visited PSA (V-PSA) (or local PSA (L-PSA)).

[0095] 6. PCF: Primarily used as a unified policy framework to guide network behavior, providing policy rule information to control plane network elements (such as AMF, SMF, etc.).

[0096] 7. AF: Primarily used to provide services to 3GPP networks, such as interacting with PCF for policy control.

[0097] 8. Network slice selection function (NSSF): mainly used for network slice selection.

[0098] 9. UDM: Primarily used for UE subscription data management, including UE identifier storage and management, UE access authorization, etc.

[0099] 10. DN: Primarily used by operators to provide data services to the UE. Examples include the Internet, third-party service networks, and IP Multimedia Service (IMS) networks.

[0100] 11. AUSF: Primarily used for user authentication, etc.

[0101] Figure 2 This is a schematic diagram of another network architecture applicable to embodiments of this application.

[0102] like Figure 2As shown, the network architecture may include, but is not limited to: SMF (such as V-SMF and H-SMF), UE, UPF (such as V-UPF and H-UPF), PSA (such as L-PSA), Domain Name System (DNS), PCF (such as H-PCF), and Edge Application Server Discovery Function (EASDF). In this architecture, Domain Name System (DNS) messages may terminate at the HPLMN's EASDF. The fact that a DNS message terminates at the HPLMN's EASDF can indicate that the DNS message is processed by the HPLMN's EASDF, or that the destination address of the DNS message is the HPLMN's EASDF, or that the HPLMN's EASDF receives the DNS message. The Edge Application Server Discovery Function, for example, may also be called an Edge Application (Service) Discovery Function, Application Instance Discovery Function, Multi-access Edge Computing (MEC) Application (Server) Discovery Function, etc., without limitation.

[0103] EASDF is primarily used to assist edge application server (EAS) discovery. Its main functions include processing DNS messages according to SMF instructions. This processing may include, but is not limited to: reporting DNS messages to the SMF, adding the EDNS-client-subnet option (ECS option) to the DNS query, forwarding the DNS query to the DNS server, and forwarding the DNS response to the UE. EDNS stands for Extended Mechanisms for DNS. In this application, for distinction, the centralized DNS server deployed in the HPLMN is referred to as the C-DNS server, and the local DNS server deployed in the VPLMN is referred to as the L-DNS server.

[0104] For introductions to other network elements, please refer to [link / reference]. Figure 1 The description in the text will not be repeated here.

[0105] exist Figure 1 or Figure 2In the network architecture shown, network elements can communicate with each other via interfaces. For example, the UE connects to the AN device through the radio resource control (RRC) protocol, and the UE and the AN device communicate using the Uu interface. Alternatively, you can refer to... Figure 1 The interface shown will not be described in detail here.

[0106] It should be understood that the network architecture shown above is merely illustrative, and the network architecture applicable to the embodiments of this application is not limited thereto. Any network architecture capable of implementing the functions of the above-described network elements is applicable to the embodiments of this application. Furthermore, the network architecture shown above may also include other network elements, such as network exposure functions (NEF) and unified data repository (UDR), which are not limited thereto. NEF is mainly used to securely expose services and capabilities provided by 3GPP network functions to the outside world. In this application, for distinction, the NEF in HPLMN is referred to as the home NEF (H-NEF), and the NEF in VPLMN is referred to as the visited NEF (V-NEF). In this application, for distinction, the UDR in HPLMN is referred to as the home UDR (H-UDR), and the UDR in VPLMN is referred to as the visited UDR (V-UDR).

[0107] It should also be understood that Figure 1 or Figure 2 The functions or network elements shown, such as AMF, SMF, UPF, PCF, UDM, NSSF, and AUSF, can be understood as network elements used to implement different functions, such as network slices that can be combined as needed. These network elements can be independent devices or integrated into the same device to implement different functions. They can be network components in hardware devices, software functions running on dedicated hardware, or virtualization functions instantiated on a platform (e.g., a cloud platform). This application does not limit the specific form of the above network elements.

[0108] It should also be understood that the above naming is defined solely for the purpose of distinguishing different functions and should not constitute any limitation on this application. This application does not preclude the possibility of using other naming conventions in 6G networks and other future networks. For example, in 6G networks, some or all of the above-mentioned network elements may use the terminology from 5G, or they may use other names, etc.

[0109] To facilitate understanding of the embodiments of this application, several basic concepts involved in the embodiments of this application are briefly explained. It should be understood that the basic concepts introduced below are based on the basic concepts specified in the current protocol for simple explanation, but do not limit the embodiments of this application to be applied only to existing systems. Therefore, the names that appear when describing existing systems are functional descriptions, and the specific names are not limited, but only indicate functions, and can be extended to other systems, such as 6G or future communication systems.

[0110] 1. EAS: Can refer to an application or a server application (e.g., social media software, AR, VR, etc.) deployed and running on a data network. EAS can also be referred to as any of the following: edge application (server), application instance, edge application instance, MEC application (server), or EAS function, etc.

[0111] In edge computing (EC) deployment scenarios, certain services may be provided by multiple Edge Application Servers (EASs) deployed at the network edge. These multiple EASs can provide the same services and content, and most of them have different IP addresses. In an EC scenario, when a UE accesses this service, it can request access to the nearest available EAS.

[0112] EAS can be deployed on the local data network (local DN). The network establishes a transmission path for the UE by selecting a UPF that is closer to the local DN, so as to ensure that the UE can access edge services normally.

[0113] 2. EAS deployment information: This includes information about the deployment of EAS in the edge network.

[0114] As an example, EAS deployment information may include one or more of the following: DNN, single-network slice selection assistance information (S-NSSAI), external group identifier / internal group identifier, application ID (AppID), full qualified domain name (FQDN), DNS server information, and EAS IP address range information. See Table 1 for descriptions of each parameter.

[0115] Table 1

[0116]

[0117] The terminology used in this application has been briefly explained above, and will not be repeated in the following embodiments.

[0118] As mentioned above, the UE may access the VPLMN via HR roaming, and the VPLMN will provide services to the UE. If the UE accesses via HR roaming, for edge application services, on the one hand, since the session anchor is in the HPLMN, the application server (AS) IP (such as the EAS IP) returned by the DNS server deployed in the HPLMN is close to the H-UPF, but may be far from the UE, causing the UE to access the EAS through a roundabout path, resulting in a poor user experience; on the other hand, if the EAS deployed in the VPLMN is used, according to the existing edge service discovery mechanism, it is difficult for the UE to obtain the EAS information deployed in the VPLMN.

[0119] This application proposes a scheme to enable the discovery of EAS within the VPLMN in HR roaming scenarios by sharing VPLMN's EAS deployment information with HPLMN (or, V-SMF to H-SMF). For example, the session management network element in the HPLMN receives first information corresponding to the terminal device from the VPLMN. This first information indicates the deployment location of the EAS within the VPLMN. The HPLMN then obtains the EAS deployment information corresponding to this first information, thus enabling it to determine which locations within the VPLMN contain edge application servers. Based on the first information corresponding to the terminal device, the HPLMN obtains the deployment information of the EAS that the terminal device may access (or can access). Therefore, when a terminal device accesses the VPLMN via HR roaming, the session management network element in the HPLMN learns which locations within the VPLMN contain edge application servers that the terminal device may access. This assists the terminal device in accessing edge application services within the VPLMN, enabling the discovery of local EAS (i.e., EAS within the VPLMN) in HR roaming scenarios. Furthermore, the HPLMN receives the first information corresponding to the terminal device, eliminating the need to receive first information from other terminal devices (such as those not served by the session management network element in the HPLMN). This not only reduces signaling overhead from transmitting first information but also improves the security of EAS deployment information sent to the session management network element in the home network. Therefore, this application can effectively solve the problem of local EAS discovery in HR roaming scenarios.

[0120] In the embodiments of this application, local EAS discovery is mentioned many times. It can be understood that, unless otherwise specified, local EAS discovery means discovering the EAS of the visited network (such as VPLMN).

[0121] It is understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0122] The communication method provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings. The embodiments provided in this application can be applied to the above-described embodiments. Figure 1 or Figure 2 The network architecture shown is not limited.

[0123] Figure 3 This is a schematic diagram of a communication method 300 provided in an embodiment of this application. Method 300 may include the following steps.

[0124] 310. The session management network element in the home network receives the first information corresponding to the terminal device from the session management network element in the visited network. The first information is used to indicate the deployment location of the EAS in the visited network.

[0125] The visited network refers to the network that the terminal device accesses after leaving its home network, such as a VPLMN. The home network refers to the network that the terminal device is subscribed to, such as an HPLMN. The following explanation will primarily use a VPLMN as the visited network and an HPLMN as the home network as an example.

[0126] Session management network elements in the home network refer to those deployed in the home network, such as those deployed in an HPLMN. Similarly, session management network elements in the visited network refer to those deployed in the visited network, such as those deployed in a VPLMN. For simplicity and ease of understanding, the following explanation uses H-SMF as the session management network element in the home network and V-SMF as the session management network element in the visited network as an example.

[0127] The first information corresponding to the terminal device can be used to indicate the deployment location of the EAS accessed by the terminal device in the visited network. As an example, the first information can be in the form of a Data Network Access Identifier (DNAI). For instance, the first information corresponding to the terminal device may consist of N DNAIs, where N is an integer greater than or equal to 1. For example, in step 310, the H-SMF receives N DNAIs from the V-SMF. The method for determining the first information corresponding to the terminal device will be explained in detail later.

[0128] 320. The session management network element in the home network obtains the EAS deployment information corresponding to the first information based on the first information.

[0129] For example, in step 310, H-SMF receives N DNAIs from V-SMF, and in step 320, H-SMF obtains the EAS deployment information corresponding to the N DNAIs.

[0130] Based on the above technical solution, the session management element in the home network receives first information corresponding to the terminal device from the session management element in the visited network. This first information can be used to indicate the deployment locations of allowed EAS in the visited network. The session management element in the home network then obtains the corresponding EAS deployment information based on this first information. In this way, the session management element in the home network can know which locations in the visited network contain edge application servers that the terminal device may access (or can access). After the terminal device accesses the visited network via HR roaming, because the session management element in the home network knows which locations in the visited network contain edge application servers that the terminal device may access, it can assist the terminal device in accessing edge application services in the visited network, improving the success rate of the terminal device accessing edge application services in the visited network, and realizing the discovery of local EAS in HR roaming scenarios. Furthermore, the session management element in the home network does not need to receive first information corresponding to other terminal devices (such as terminal devices not served by the session management element in the home network), which not only reduces the signaling overhead of transmitting first information but also improves the security of EAS deployment information sent to the session management element in the home network.

[0131] For the sake of brevity and ease of description, the first piece of information corresponding to the terminal device will be denoted as information #A in the following text.

[0132] As mentioned earlier, information #A can be used to indicate the deployment location of the EAS accessed by the terminal device in the visited network. One possible implementation is that information #A is determined based on the location of the terminal device. The location of the terminal device reflects its position. For example, the location of the terminal device can be represented by a tracking area identifier (TAI). Another example is that the location of the terminal device can be represented by a cell ID. Yet another example is that the location of the terminal device can be represented by its geographic location (e.g., latitude and longitude coordinates). For ease of understanding and explanation, the following explanation primarily uses the representation of the terminal device's location using a TAI as an example. It is understood that the TAI in the following text can be replaced with other information that reflects the location of the terminal device.

[0133] Optionally, before step 310, method 300 further includes: visiting the session management network element in the network to determine information #A. One possible implementation is that the V-SMF determines information #A based on the location of the terminal device. For example, information #A may be N DNAIs, and the V-SMF can determine these N DNAIs based on the location of the terminal device (such as TAI).

[0134] Taking the session management network element in the visited network as V-SMF, and information #A as N DNAIs, the V-SMF can optionally determine the N DNAIs in the following ways.

[0135] In the first possible implementation, V-SMF determines N DNAIs based on the location of the terminal device.

[0136] For example, V-SMF can determine, based on the S-NSSAI and DNN corresponding to the session, that the terminal device can (or is able to, or will, or may) access N DNAIs at its current location. V-SMF then determines these N DNAIs and sends them to H-SMF.

[0137] Based on the first possible implementation described above, V-SMF can determine information #A (i.e., N DNAIs) based on the location of the terminal device. In this way, by considering the location of the terminal device, it can avoid sending information #A that the terminal device doesn't need (such as the deployment location of the EAS, which the terminal device is almost impossible to access), or sending information #A corresponding to other terminal devices to the H-SMF. This not only saves signaling overhead but also improves the security of EAS deployment information sent to the H-SMF.

[0138] The second possible implementation is that V-SMF determines N DNAIs based on the location and policy information of the terminal device.

[0139] For example, the V-SMF can configure and store this policy information, and when using this policy information, the V-SMF can directly read the policy information locally; as another example, the V-SMF can configure this policy information, and other core network elements in the VPLMN (such as the V-PCF) can store this policy information, and when using this policy information, the V-SMF can obtain the policy information from other core network elements.

[0140] The policy information can be used to indicate the deployment locations of EAS that are allowed to be sent from the VPLMN to the HPLMMN. For example, the policy information can be used to indicate which DNAIs within the VPLMN can be opened (or sent) to other PLMNs. Specifically, it can be represented in the form of a DNAI list and / or a PLMN list, or in other ways, without limitation.

[0141] One possible scenario is that the policy information includes DNAIs that the VPLMN allows (or authorizes) to be shared with other PLMNs. This policy information directly reveals which DNAIs within the VPLMN can be shared with other PLMNs. As an example, Tables 2 and 3 show the format of the policy information suitable for this scenario.

[0142] Table 2

[0143] PLMN#1 DNAI#1, DNAI#2 PLMN#2 DNAI#2, DNAI#3 PLMN#3 DNAI#1

[0144] Table 3

[0145]

[0146] Taking Table 2 as an example, VPLMN can open DNAI#1 and DNAI#2 to PLMN#1, VPLMN can open DNAI#2 and DNAI#3 to PLMN#2, and VPLMN can open DNAI#1 to PLMN#3. For example, the PLMN ID in Table 2 can be the ID of HPLMN. For instance, if V-SMF knows that HPLMN is PLMN#1, then based on Table 2, it can be known that VPLMN can open DNAI#1 and DNAI#2 to this HPLMN, that is, N DNAIs include DNAI#1 and DNAI#2.

[0147] Taking Table 3 as an example, VPLMN can open to PLMN#1, PLMN#2, and PLMN#3: DNAI#1, DNAI#2, and DNAI#3. For example, the PLMN ID in Table 3 can be the ID of the HPLMN. For instance, if V-SMF knows that the HPLMN is PLMN#3, then based on Table 3, it can be known that VPLMN can open to this HPLMN: DNAI#1, DNAI#2, and DNAI#3, that is, N DNAIs include: DNAI#1, DNAI#2, and DNAI#3.

[0148] This application does not restrict the method by which the V-SMF determines the HPLMN. As an example, the V-SMF can identify the HPLMN based on the identifiers of the network elements deployed in the HPLMN (such as the H-SMF identifier, or the identifiers of other network elements). One possible method is for the V-SMF to receive the H-SMF identifier (e.g., H-SMF ID, which is not limited in this application) from the AMF, and then determine the HPLMN identifier based on this H-SMF identifier, thus determining the HPLMN. This will not be elaborated further below.

[0149] It is understood that Tables 2 and 3 are merely illustrative examples and are not intended to be limiting. Any variations of Tables 2 or 3 are applicable to this application. For example, the PLMN ID in Tables 2 or 3 can be replaced with SMF IDs, such as PLMN#1 being replaced with one or more SMF IDs (i.e., the IDs of one or more SMFs corresponding to PLMN#1). As another example, the PLMN IDs in Tables 2 or 3 may correspond to a greater number of DNAIs.

[0150] It is also understood that the above description mainly uses the example of the strategy information including DNAIs that the VPLMN allows to be opened to other PLMNs, and the embodiments of this application are not limited to this. For example, the strategy information includes DNAIs that the VPLMN prohibits from being opened to other PLMNs. In this way, through the strategy information, it can be known which DNAIs in the VPLMN are prohibited from being opened to other PLMNs, and thus it can be known that the DNAIs in the VPLMN other than the DNAIs that are prohibited from being opened can be opened to other PLMNs.

[0151] Based on the second possible implementation, V-SMF can determine the second information corresponding to the terminal device based on the terminal device's location, and then determine the first information based on the second information and the aforementioned strategy information. For simplicity and ease of description, the second information corresponding to the terminal device will be denoted as information #B below.

[0152] Information #B indicates the deployment location of an EAS that a determined terminal device can (or is able to, will, or may) access in the visited network, based on the location of the terminal device. As an example, information #B can be in the form of DNAIs. For instance, information #B consists of M DNAIs, where M is an integer greater than or equal to 1, and M is greater than or equal to N. The N DNAIs may be all of the M DNAIs (i.e., M equals N), or the N DNAIs may be a subset of the M DNAIs (i.e., M is greater than N).

[0153] The following example uses information #A and information #B to illustrate DNAI.

[0154] For example, V-SMF can determine that there are M DNAIs accessible at the current location of the terminal device based on the S-NSSAI and DNN corresponding to the session; further, V-SMF determines N DNAIs from the M DNAIs based on the above policy information.

[0155] Assuming V-SMF knows that HPLMN is PLMN#1, V-SMF determines the M DNAIs as: DNAI#1, DNAI#2, and DNAI#3. For example, taking Table 2 as an example, the PLMN ID in Table 2 can be the ID of HPLMN. Based on Table 2, it can be known that VPLMN can provide DNAI#1 and DNAI#2 to PLMN#1. Therefore, V-SMF determines that the N DNAIs include some of the M DNAIs, that is, the N DNAIs include DNAI#1 and DNAI#2, but not DNAI#3. As another example, taking Table 3 as an example, the PLMN ID in Table 3 can be the ID of HPLMN. Based on Table 3, it can be known that VPLMN can provide DNAI#1, DNAI#2, and DNAI#3 to PLMN#1. Therefore, V-SMF determines that the N DNAIs are the M DNAIs, that is, the N DNAIs include: DNAI#1, DNAI#2, and DNAI#3.

[0156] Based on the second possible implementation described above, V-SMF can determine information #A (i.e., N DNAIs) according to the location and policy information of the terminal device. This not only considers the location of the terminal device, thus saving signaling overhead and improving the security of EAS deployment information sent to H-SMF, but also takes into account the authorization status of VPLMN (such as providing H-SMF with VPLMN-permitted DNAIs), thereby balancing the requirements of VPLMN itself and improving network security.

[0157] The third possible implementation is that V-SMF determines M DNAIs (i.e., information #B) based on the location of the terminal device, and queries N DNAIs from V-PCF based on the M DNAIs.

[0158] For example, V-PCF can store DNAIs that are allowed to be shared with other PLMNs (as shown in Table 2 or Table 3), and V-PCF can directly read them locally when needed; as another example, other core network elements in VPLMN (such as V-UDR) store DNAIs that are allowed to be shared with other PLMNs, and V-PCF can obtain them from other core network elements when needed.

[0159] For example, the V-SMF determines M DNAIs based on the location of the terminal device. The V-SMF sends a request message to the V-PCF, which includes the M DNAIs. This request message requests the deployment locations of EAS that the VPLMN can send to the HPLMN. Specifically, this request message requests the DNAIs from the M DNAIs that can be opened to the HPLMN (or H-SMF).

[0160] Assuming HPLMN is PLMN#1, V-SMF identifies M DNAIs as DNAI#1, DNAI#2, and DNAI#3. V-SMF sends a request message to V-PCF, which includes the M DNAIs (i.e., DNAI#1, DNAI#2, and DNAI#3). For example, taking Table 2 as an example, the PLMN ID in Table 2 can be the ID of HPLMN. Based on Table 2, it can be seen that VPLMN can open DNAI#1 and DNAI#2 to PLMN#1. Therefore, V-PCF identifies N DNAIs, including some of the M DNAIs, that is, N DNAIs include DNAI#1 and DNAI#2, but not DNAI#3 among the M DNAIs; V-PCF can send DNAI#1 and DNAI#2 to V-SMF. For example, taking Table 3 as an example, the PLMN ID in Table 3 can be the ID of the HPLMN. Based on Table 3, we know that the VPLMN can open to PLMN#1: DNAI#1, DNAI#2, and DNAI#3. Therefore, the V-PCF determines that the N DNAIs are the M DNAIs, that is, the N DNAIs include: DNAI#1, DNAI#2, and DNAI#3. The V-PCF can send: DNAI#1, DNAI#2, and DNAI#3 to the V-SMF, or the V-PCF can send an acknowledgment message to the V-SMF, which indicates that all M DNAIs in the request message are allowed to be opened (i.e., the N DNAIs are the M DNAIs). As an example, if the N DNAIs are the same as the M DNAIs, the V-PCF can send a smaller bit of acknowledgment message to the V-SMF (such as a 1-bit acknowledgment message), thereby saving signaling overhead.

[0161] Optionally, the query message may also include an HPLMN ID (or H-SMF ID) used to identify the HPLMN. In one possible scenario, the V-PCF stores DNAIs that are allowed to be shared with other PLMNs, and these DNAIs are identical (as shown in the example in Table 3). The V-PCF receives a request message from the V-SMF containing M DNAIs. The V-PCF determines which of these M DNAIs are allowed to be shared with other PLMNs (i.e., N DNAIs) and sends these N DNAIs to the V-SMF. Another possible scenario is that the V-PCF stores DNAIs that can be opened to other PLMNs, and the DNAIs that can be opened to other PLMNs are not completely identical (as shown in the example in Table 2); the V-PCF receives a request message from the V-SMF, and the request message includes M DNAIs and HPLMN IDs; the V-PCF determines the HPLMN based on the HPLMN ID in the request message, and determines the DNAIs (i.e., N DNAIs) that can be opened to the HPLMN from the M DNAIs, and sends the N DNAIs to the V-SMF.

[0162] Based on the third possible implementation described above, the V-SMF can determine information #B (i.e., M DNAIs) according to the location of the terminal device, and then query (or request, or query) the V-PCF to determine which of the M DNAIs can be opened (or sent) to the HPLMN. This approach not only considers the location of the terminal device, thus saving signaling overhead and improving the security of EAS deployment information sent to the H-SMF, but also takes into account the authorization status of the VPLMN (such as providing the H-SMF with DNAIs permitted by the VPLMN), thereby balancing the requirements of the VPLMN itself and improving network security. Furthermore, the V-SMF can dynamically send requests to the V-PCF to determine which of the M DNAIs can be opened (or sent) to the HPLMN based on actual circumstances, making the solution flexible.

[0163] The foregoing section introduced three implementation methods for V-SMF to determine N DNAIs. These methods are illustrative and any variations thereof are applicable to the embodiments of this application. The following section describes a scheme for H-SMF to obtain the deployment information of the EAS corresponding to information #A.

[0164] Taking the session management network element in the home network as H-SMF, the H-SMF can optionally obtain the EAS deployment information corresponding to information #A, which may include the following two schemes:

[0165] Option A: H-SMF obtains the EAS deployment information corresponding to #A from the VPLMN;

[0166] Option B: H-SMF obtains the EAS deployment information corresponding to #A from HPLMN.

[0167] The two schemes are described in detail below.

[0168] Option A: H-SMF obtains information from VPLMN #A, corresponding to the EAS deployment information.

[0169] Under Scheme A, one possible scenario is that the data management network element in the VPLMN stores the EAS deployment information in the VPLMN. Thus, after receiving information #A, the H-SMF can query the data management network element in the VPLMN to retrieve the corresponding EAS deployment information for #A.

[0170] In the embodiments of this application, a data management network element refers to a network element that can be used to manage and / or store EAS deployment information corresponding to information #A, or a network element used to provide EAS deployment information corresponding to information #A. As an example, data management network elements include, for example, UDR and / or UDM. It is understood that the naming of data management network elements does not limit the scope of protection of the embodiments of this application; for example, when the data management network element is a UDR, it can also be called a data storage network element or a unified data storage network element. A data management network element in a VPLMN refers to a data management network element deployed in a VPLMN, such as a UDR (i.e., V-UDR) deployed in a VPLMN and / or a UDM (i.e., V-UDM) deployed in a VPLMN.

[0171] Taking information #A in the form of DNAI as an example, as an example, the EAS deployment information in VPLMN (such as the data management network element in VPLMN) can exist in the form of Table 4.

[0172] Table 4

[0173] DNAI#1 EAS Deployment Information #1 DNAI#2 EAS Deployment Information #2 DNAI#3 EAS Deployment Information #3

[0174] Taking Table 4 as an example, the DNAI in Table 4 refers to the DNAI in the VPLMN. For instance, information #A includes DNAI#1, DNAI#2, and DNAI#3. From Table 4, we can see that the EAS deployment information for DNAI#1 is EAS deployment information #1, the EAS deployment information for DNAI#2 is EAS deployment information #2, and the EAS deployment information for DNAI#3 is EAS deployment information #3.

[0175] It should be understood that Table 4 is merely illustrative and not intended to be limiting. Any variations of Table 4 are applicable to this application. For example, a column for PLMN IDs could be added to Table 4 to represent the PLMN corresponding to the DANI. Furthermore, Table 4 could include an even greater number of DNAIs.

[0176] Based on scheme A, one possible implementation is that H-SMF can query and obtain the EAS deployment information corresponding to information #A from the data management network element in VPLMN through the interaction between H-NEF and V-NEF.

[0177] Taking the data management network element in the VPLMN as V-UDR, for example, after H-SMF receives N DNAIs, it can send a request message to H-NEF, which includes the N DNAIs; H-NEF forwards the request message to V-NEF; V-UDR stores the EAS deployment information in the VPLMN (as shown in Table 4), and V-NEF queries the EAS deployment information corresponding to the N DNAIs from V-UDR; further, V-NEF sends the EAS deployment information corresponding to the N DNAIs to H-NEF; H-NEF then forwards the EAS deployment information corresponding to the N DNAIs to H-SMF, and then H-SMF queries the V-UDR to obtain the EAS deployment information corresponding to the N DNAIs.

[0178] Optionally, the request message also includes a VPLMN ID, which can be used to identify the VPLMN or to determine the NEF (i.e., V-NEF) within the VPLMN. For example, after receiving a request message from the H-SMF, the H-NEF can identify the VPLMN based on the VPLMN ID in the request message, and then determine the V-NEF of the VPLMN, thereby forwarding the request message to the V-NEF. It can be understood that when the H-NEF sends the request message to the V-NEF, it does not need to carry the VPLMN ID to save signaling overhead.

[0179] It is understood that the above implementation is illustrative and the embodiments of this application are not limited thereto. For example, the H-SMF can query the EAS deployment information corresponding to information #A from the data management network element in the VPLMN through other network elements, or the H-SMF can directly query the EAS deployment information corresponding to information #A from the data management network element in the VPLMN.

[0180] Option B: H-SMF obtains the EAS deployment information corresponding to #A from HPLMN.

[0181] Under Scheme B, in one possible scenario, the data management network element in the HPLMN stores the EAS deployment information in the VPLMN. Thus, after receiving information #A, the H-SMF can query the corresponding EAS deployment information from the H-UDR. The data management network element in the HPLMN refers to the data management network element deployed in the HPLMN, such as a UDR (i.e., H-UDR) deployed in the HPLMN and / or a UDM (i.e., H-UDM) deployed in the HPLMN.

[0182] Taking information #A in the form of DNAI as an example, as an example, the EAS deployment information in HPLMN (such as the data management network element in HPLMN) can exist in the form of Table 5.

[0183] Table 5

[0184]

[0185] Taking Table 5 as an example, the PLMN ID in Table 5 can be the ID of a VPLMN, and the DNAI can be the DNAI in the corresponding VPLMN. For example, information #A includes DNAI#1, DNAI#2, and DNAI#3. From Table 5, we can see that the EAS deployment information for DNAI#1 is EAS deployment information #1, the EAS deployment information for DNAI#2 is EAS deployment information #2, and the EAS deployment information for DNAI#3 is EAS deployment information #3. As another example, information #A includes DNAI#4, DNAI#5, and DNAI#6. From Table 5, we can see that the EAS deployment information for DNAI#4 is EAS deployment information #4, the EAS deployment information for DNAI#5 is EAS deployment information #5, and the EAS deployment information for DNAI#6 is EAS deployment information #6.

[0186] It should be understood that Table 5 is merely illustrative and not intended to be limiting. Any variations of Table 5 are applicable to this application. For example, the DNAIs in Table 5 may be DNAIs that the corresponding PLMN allows to be shared with other PLMNs. For instance, the DNAIs that PLMN#1 allows to be shared with other PLMNs include: DNAI#1, DNAI#2, and DNAI#3. Furthermore, Table 5 may include an additional number of DNAIs. Also, Table 5 may include an additional column for PLMN IDs, indicating which PLMNs the corresponding PLMN allows to share its DNAIs with.

[0187] Based on scheme B, one possible implementation is that H-SMF can query and obtain the EAS deployment information corresponding to information #A from the data management network element in HPLMN through H-NEF.

[0188] Taking the data management network element in HPLMN as H-UDR, for example, after H-SMF receives N DNAIs, it can send a request message to H-NEF, which includes the N DNAIs; H-UDR stores the EAS deployment information corresponding to the N DNAIs (as shown in Table 5), and H-NEF queries the EAS deployment information corresponding to the N DNAIs from H-UDR; furthermore, H-NEF returns the EAS deployment information corresponding to the N DNAIs to H-SMF, and then H-SMF queries H-UDR to obtain the EAS deployment information corresponding to the N DNAIs.

[0189] Optionally, the request message may also include a VPLMN ID, which can be used to identify a VPLMN. For example, the H-UDR stores EAS deployment information for multiple PLMNs (as shown in Table 5). The H-UDR can identify a VPLMN based on the VPLMN ID in the request message, and then determine the EAS deployment information corresponding to N DNAIs in the VPLMN.

[0190] It is understood that the above implementation is illustrative and the embodiments of this application are not limited thereto. For example, the H-SMF can query the EAS deployment information corresponding to information #A from the data management network element in the HPLMMN through other network elements, or the H-SMF can directly query the EAS deployment information corresponding to information #A from the data management network element in the HPLMMN.

[0191] As an example, Scheme B can be used in scenarios where there is a strong trust relationship between HPLMN and VPLMN.

[0192] The above describes the relevant solutions for obtaining EAS deployment information corresponding to information #A via H-SMF, combining two approaches.

[0193] Optionally, method 300 further includes: H-SMF determining DNS handling rule based on EAS deployment information corresponding to the first information (such as N DNAIs).

[0194] DNS processing rules can be used to process DNS messages, such as DNS messages related to terminal devices. For example, DNS processing rules can be used to process DNS query messages.

[0195] As an example, DNS processing rules may include one or more of the following information: FQDN range, ECS option, local DNS (L-DNS) server address, and DNS forwarding rules.

[0196] The ECS option can be used to represent the UE's location information.

[0197] DNS forwarding rules, also known as forwarding rules or data plane forwarding rules, are used by EASDF to process DNS messages from the UE. For example, when the FQDN in a DNS query sent by the UE matches the FQDN range in the DNS processing rules, EASDF adds an ECS option to the DNS query based on the DNS forwarding rules. As another example, when the FQDN in a DNS query sent by the UE matches the FQDN range in the DNS processing rules, EASDF forwards the DNS query (such as the DNS query with the added ECS option) to the DNS server based on the DNS forwarding rules.

[0198] For relevant schemes regarding DNS processing rules, existing technologies can be referenced, and the embodiments of this application do not limit them.

[0199] Optionally, method 300 further includes: the H-SMF sending an IP address and / or domain name (such as an FQDN) to the V-SMF, thereby triggering the V-SMF to perform traffic steering for the HR session within the VPLMN. Here, the IP address is the IP address corresponding to the EAS, representing the IP address of the EAS accessed by the terminal device in the VPLMN. The domain name is the domain name corresponding to the EAS, representing the domain name of the EAS accessed by the terminal device in the VPLMN.

[0200] For example, the H-SMF receives the EAS IP address and / or FQDN from the EASDF; the H-SMF sends the EAS IP address and / or FQDN to the V-SMF; the V-SMF selects a routing point in the visited network and / or an anchor point UPF deployed in the VPLMN for the terminal device's session (such as the terminal device's HR session) based on the EAS IP address and / or FQDN. The routing point can be used to route packets to the VPLMN, such as routing service packets accessing the EAS deployed in the VPLMN to the VPLMN. In this way, although the current terminal device session is an HR session, the terminal can access the EAS deployed in the VPLMN directly through the UPF deployed in the VPLMN instead of going through the HPLMN's UPF, greatly improving service access efficiency and reducing service access latency.

[0201] Optionally, the splitting point can be an uplink classifier (UL CL) or a branching point (BP). When a terminal device needs to transmit services, it can establish multiple PDU sessions to the same or different DNs through the SMF. The SMF can control the data routing of the PDU, allowing this PDU session to have multiple N6 interfaces simultaneously. The UPF connecting each N6 interface is called a PSA, and each PSA provides a different path to the same DN. Therefore, in one possible way, the V-SMF can determine the UL CL in the VPLMN. For different types of PDU sessions, the SMF can insert a UL CL into the data transmission path of that PDU session. The UL CL function is provided by the UPF and is used to forward packets that meet the service filtering rules to the specified path. When a UL CL is inserted into a PDU session data channel, this PDU session can have multiple PDU session anchors, providing multiple different paths to the same DN. In other words, the function of the UL CL can be to transmit uplink data to different PSAs and merge downlink data into the UE. Another possible approach is that V-SMF can identify branch points in a VPLMN. Specifically, data from each PSA can converge to a common UPF, which functions as a branch point. The branch point forwards uplink data to different PSAs and merges downlink data from PSAs. Essentially, a branch point can be considered a UPF; in other words, a branch point is a branching function that the aforementioned UPF can implement.

[0202] It is understood that the above is merely an illustrative example and is not intended to be limiting.

[0203] To facilitate understanding, the following will be combined with... Figures 4 to 9 The embodiments of this application are illustrated by way of example. In the following example, it is assumed that information #A represents N DNAIs and the data management network element in the VPLMN is a V-UDR. The specific steps involved can be referred to the description above.

[0204] First, combined Figure 4 and 5 The architecture shown above briefly introduces the implementation methods of scheme A and scheme B.

[0205] Figure 4 This is a schematic diagram of the network architecture applicable to scheme A provided in the embodiments of this application. For example... Figure 4As shown, in this architecture, V-UDR can store EAS deployment information in VPLMN, and H-SMF can obtain EAS deployment information corresponding to N DNAIs from VPLMN (such as V-UDR). As an example, in this architecture, to achieve local EAS discovery in HR roaming scenarios, the following steps can be included.

[0206] 401, V-SMF sends N DNAIs to H-SMF.

[0207] One possible approach is for the V-SMF to determine the N DNAIs based on its local policy information and then send the N DNAIs to the H-SMF. Another possible approach is for the V-SMF to query the N DNAIs from the V-PCF and then send the N DNAIs to the H-SMF. For details on how the V-SMF determines the N DNAIs, please refer to the relevant description in Method 300; it will not be repeated here.

[0208] 402. H-SMF requests EAS deployment information corresponding to N DNAIs from V-UDR via H-NEF.

[0209] After receiving the N DNAIs, H-SMF can request EAS deployment information corresponding to the N DNAIs from H-NEF; furthermore, H-NEF can request EAS deployment information corresponding to the N DNAIs from V-UDR.

[0210] The H-NEF requests EAS deployment information corresponding to N DNAIs from the V-UDR. This could involve the H-NEF sending a request message to the V-NEF, which then forwards the message to the V-UDR. The request message includes N DNAIs and is used to request the EAS deployment information corresponding to those N DNAIs. Optionally, the request message may also include a VPLMN ID, which can be used to identify the VPLMN, i.e., the VPLMN the UE is currently in.

[0211] After receiving a request from H-NEF, V-UDR can retrieve the EAS deployment information corresponding to N DNAIs from the stored EAS deployment information in VPLMN, and send the EAS deployment information corresponding to the N DNAIs to H-NEF. Further, H-NEF sends the EAS deployment information corresponding to the N DNAIs to H-SMF, thus allowing H-SMF to obtain the EAS deployment information corresponding to the N DNAIs.

[0212] Through the above steps, H-SMF can obtain EAS deployment information corresponding to N DNAIs from VPLMN (such as V-UDR).

[0213] After receiving the EAS deployment information corresponding to N DNAIs, H-SMF can determine the DNS processing rules and send the DNS processing rules to EASDF, i.e., step 403.

[0214] 403, H-SMF sends DNS processing rules to EASDF.

[0215] exist Figure 4 In the architecture shown, EASDF is located in HPLMN and can be used to assist in EAS discovery in VPLMN.

[0216] Regarding DNS processing rules, please refer to the relevant description in Method 300 above, which will not be repeated here. The EAS server corresponding to the domain name included in the DNS processing rules can be deployed on a VPLMN.

[0217] After obtaining the DNS processing rules from the H-SMF, the EASDF can process the DNS messages sent by the UE accordingly. For example, when a UE wants to access an edge service or request an edge service (or the address of an edge server), it can initiate a DNS query, which contains the domain name corresponding to the edge service. This is step 404.

[0218] 404, the UE sends a DNS query to EASDF.

[0219] One possible implementation is that the UE sends the DNS query to the EASDF via the user plane, through the RAN and UPF (i.e., V-UPF and H-UPF).

[0220] After receiving a DNS query from the UE, the EASDF can process the DNS query according to the DNS processing rules received from the H-SMF. For example, if the EASDF detects that the domain name (e.g., FQDN) in the UE's DNS query matches a domain name in the DNS processing rules, or if the EAS server corresponding to the domain name in the DNS query is deployed in the VPLMN, then the EASDF adds an ECS option to the DNS query and sends the DNS query with the added ECS option to the C-DNS server. Alternatively, when the domain name (e.g., FQDN) in the DNS query sent by the UE matches a domain name in the DNS processing rules, the EASDF determines the address of the L-DNS server located in the VPLMN according to the DNS processing rules and sends the UE's DNS query to the L-DNS server. Figure 4As shown, EASDF can determine the L-DNS server based on DNS processing rules, and then forward DNS messages to the L-DNS server, thereby allowing the L-DNS server to determine the EAS.

[0221] In this embodiment, assuming the domain name in the UE's DNS query matches the domain name in the DNS processing rules, the EASDF adds an ECS option to the DNS query and can then forward the DNS query with the added ECS option to the C-DNS server. Further, the C-DNS server can send a response to the EASDF, such as a DNS response. This DNS response may contain address information, such as the EAS IP address and / or FQDN. After receiving the DNS response, the EASDF can report the address information contained in the DNS response, such as the EAS IP address and / or FQDN, to the H-SMF.

[0222] 405, EASDF sends a DNS report request to H-SMF.

[0223] The DNS report request includes the EAS IP address and / or FQDN. After receiving the DNS report request, the H-SMF can send the EAS IP address and / or FQDN to the V-SMF to trigger traffic steering for the UE's HR session.

[0224] 406, H-SMF sends a notify message to V-SMF.

[0225] The notification message carries the EAS IP address and / or FQDN, and can be used to trigger traffic steering for the HR session of the UE.

[0226] It is understood that the above steps are merely illustrative and the embodiments of this application are not limited thereto. In actual communication, more processing steps may be included. For example, please refer to the description of method 600 and method 700 below.

[0227] Through the above scheme, the H-SMF obtains N DNAIs accessible to the UE from the VPLMN, and further obtains the EAS deployment information corresponding to these N DNAIs from the VPLMN. This allows the H-SMF to determine which locations within the VPLMN are equipped with Edge Application Servers (EAS), thus assisting the EASDF in discovering local EAS. Furthermore, the H-SMF can determine DNS processing rules based on the EAS deployment information corresponding to the N DNAIs, and the EASDF is responsible for processing DNS query messages from the UE, thereby enabling the discovery of local EAS in HR roaming scenarios.

[0228] Figure 5 This is a schematic diagram of the network architecture applicable to Scheme B provided in the embodiments of this application. For example... Figure 5 As shown, under this architecture, H-UDR can store EAS deployment information in VPLMN, and H-SMF can obtain EAS deployment information corresponding to N DNAIs from HPLMMN (such as H-UDR). As an example, under this architecture, to achieve local EAS discovery in HR roaming scenarios, the following steps can be included.

[0229] 501, V-SMF sends N DNAIs to H-SMF.

[0230] One possible approach is for the V-SMF to determine the N DNAIs based on its local policy information and then send the N DNAIs to the H-SMF. Another possible approach is for the V-SMF to query the N DNAIs from the V-PCF and then send the N DNAIs to the H-SMF. For details on how the V-SMF determines the N DNAIs, please refer to the relevant description in Method 300; it will not be repeated here.

[0231] 502. H-SMF requests EAS deployment information corresponding to N DNAIs from H-UDR via H-NEF.

[0232] After receiving the N DNAIs, H-SMF can request EAS deployment information corresponding to the N DNAIs from H-NEF; furthermore, H-NEF can request EAS deployment information corresponding to the N DNAIs from H-UDR.

[0233] The H-NEF requests EAS deployment information corresponding to N DNAIs from the H-UDR. This could include, for example, the H-NEF sending a request message to the H-UDR containing N DNAIs, and this request message being used to request the EAS deployment information corresponding to the N DNAIs. Optionally, the request message also includes a VPLMN ID, which can be used to identify the VPLMN, i.e., to identify the VPLMN where the UE is currently located.

[0234] After receiving a request from H-NEF, H-UDR can retrieve the EAS deployment information corresponding to N DNAIs from the stored EAS deployment information in the VPLMN, and send the EAS deployment information corresponding to the N DNAIs to H-NEF. Further, H-NEF sends the EAS deployment information corresponding to the N DNAIs to H-SMF, thus allowing H-SMF to obtain the EAS deployment information corresponding to the N DNAIs.

[0235] Through the above steps, H-SMF can obtain EAS deployment information corresponding to N DNAIs from HPLMN (such as H-UDR).

[0236] After receiving the EAS deployment information corresponding to N DNAIs, H-SMF can determine the DNS processing rules and send the DNS processing rules to EASDF, i.e., step 503.

[0237] 503, H-SMF sends DNS processing rules to EASDF.

[0238] 504, the UE sends a DNS query to EASDF.

[0239] 505, EASDF sends a DNS report request to H-SMF.

[0240] 506, H-SMF sends a notification message to V-SMF.

[0241] Steps 503-506 are similar to steps 403-406, and will not be described again here.

[0242] It is understood that the above steps are merely illustrative and the embodiments of this application are not limited thereto. In actual communication, more processing steps may be included. For example, please refer to the descriptions of methods 800 and 900 below.

[0243] Through the above scheme, the H-SMF obtains N DNAIs accessible to the UE from the VPLMN, and further obtains the EAS deployment information corresponding to these N DNAIs from the HPLMMN. This allows the H-SMF to determine which locations within the VPLMN are equipped with Edge Application Servers (EAS), thus assisting the EASDF in discovering local EAS. Furthermore, the H-SMF can determine DNS processing rules based on the EAS deployment information corresponding to the N DNAIs, and the EASDF is responsible for processing DNS query messages from the UE, thereby enabling the discovery of local EAS in HR roaming scenarios.

[0244] Below, in conjunction with Figures 6 to 9 The above possible processes are described.

[0245] Figure 6This is a schematic flowchart illustrating a communication method 600 provided in an embodiment of this application. Method 600 can be used to implement a scheme such as method 300. For example, method 600 can be used in a scenario where the V-SMF determines N DNAIs according to a local policy, and the H-SMF obtains the EAS deployment information corresponding to the N DNAIs from the VPLMN. Method 600 can... Figure 4 The architecture implementation is shown. As an example, method 600 may include the following steps.

[0246] 601, V-SMF configuration policy information.

[0247] The strategy information can be used to indicate which DNAIs within a VPLMN can be opened to other PLMNs. For details on the strategy information, please refer to the relevant description in Method 300 above; it will not be repeated here.

[0248] 602, V-UDR stores EAS deployment information in VPLMN.

[0249] For EAS deployment information, please refer to the previous terminology explanation; it will not be repeated here.

[0250] In this embodiment, V-UDR can store EAS deployment information in VPLMN, such as EAS deployment information corresponding to each DNAI in VPLMN, or EAS deployment information corresponding to DNAIs in VPLMN that are allowed to be opened to other PLMNs, without limitation.

[0251] 603, the UE sends a session establishment request message to the V-SMF.

[0252] Optionally, the session establishment request message includes: S-NSSAI, DNN, and PDU session ID.

[0253] In HR roaming scenarios, the UE can initiate an HR session establishment process. For example, the UE can send a session establishment request message to the V-SMF via the V-AMF. Specifically, the UE sends a PDU session establishment request to the V-AMF; the V-AMF sends an Nsmf interface PDU session establishment request to the V-SMF; upon receiving the Nsmf_PDUSession_Create Request, the V-SMF establishes the session context. The specific session establishment process can refer to existing technologies or future session establishment methods, and is not limited thereto.

[0254] 604, V-SMF determines N DNAIs based on policy information and the UE's location.

[0255] Among them, N DNAIs represent the DNAIs that VPLMN allows to be opened to HPLMN.

[0256] One possible implementation is that the V-SMF determines the M DNAIs accessible to the UE at its current location (represented by TAI) based on the S-NSSAI and DNN corresponding to the session; then, based on policy information, it determines the N DNAIs that can be opened to the HPLMN (or H-SMF) from the M DNAIs. Specifically, refer to the second possible implementation in method 300 above, which will not be elaborated here.

[0257] 605. The V-SMF sends N DNAIs to the H-SMF. Optionally, the V-SMF also sends a VPLMN ID or a V-SMF ID to the H-SMF, which can be used to determine the VPLMN where the UE is currently located. Specifically, if the V-SMF sends a VPLMN ID to the H-SMF, the H-SMF can directly obtain the VPLMN ID; if the V-SMF sends a V-SMF ID to the H-SMF, the H-SMF can determine the VPLMN ID based on the V-SMF ID. The N DNAIs and the VPLMN ID or V-SMF ID can be carried in the same signaling, or they can be transmitted separately; there is no restriction on this.

[0258] One possible implementation is that the V-SMF sends an Nsmf interface PDU session establishment request (Nsmf_PDUSession_Create Request) to the H-SMF. This Nsmf_PDUSession_Create Request includes N DNAIs and a VPLMNID. According to this implementation, the H-SMF can directly obtain the VPLMN ID from the PDU session establishment request.

[0259] Another possible implementation is that the V-SMF sends an Nsmf_PDUSession_Create Request to the H-SMF. This Nsmf_PDUSession_Create Request includes N DNAIs and a V-SMF ID, where the V-SMF ID may contain a VPLMN ID. According to this implementation, the H-SMF can obtain the VPLMN ID from the V-SMF ID. 606, the H-SMF sends a request message to the H-NEF.

[0260] 607, H-NEF sends a request message to V-NEF.

[0261] For example, if the request message in step 606 carries a VPLMN ID, H-NEF selects the NEF (i.e., V-NEF) in the VPLMN based on the VPLMN ID carried in the request message and sends a request message to V-NEF. The request message sent by H-NEF to V-NEF includes N DNAIs, which trigger V-NEF to query the EAS deployment information corresponding to these N DNAIs. Optionally, the request message sent by H-NEF to V-NEF may also include an HPLMN ID or an H-NEF ID. Specifically, if the request message sent by H-NEF to V-NEF also includes an HPLMN ID, V-NEF can directly obtain the HPLMN ID; if the request message sent by H-NEF to V-NEF also includes an H-NEF ID, V-NEF can determine the HPLMN ID based on the H-NEF ID.

[0262] One possible implementation is that H-NEF sends an Nnef_EASDeploymnet_SubscribeRequest to V-NEF. This Nnef_EASDeploymnet_SubscribeRequest includes N DNAIs and an HPLMN ID. This Nnef_EASDeploymnet_SubscribeRequest triggers V-NEF to query the EAS deployment information corresponding to the N DNAIs. With this implementation, V-NEF can directly obtain the HPLMN ID.

[0263] Another possible implementation involves H-NEF sending an Nnef_EASDeploymnet_SubscribeRequest to V-NEF. This Nnef_EASDeploymnet_SubscribeRequest includes N DNAIs and an H-NEF ID. The Nnef_EASDeploymnet_SubscribeRequest triggers V-NEF to query the EAS deployment information corresponding to the N DNAIs. The H-NEF ID may contain the HPLMN ID. With this implementation, V-NEF can obtain the HPLMN ID from the H-NEF ID.

[0264] 608. V-NEF obtains EAS deployment information corresponding to N DNAIs from V-UDR.

[0265] For example, V-NEF uses N DNAIs as index values ​​to query the EAS deployment information corresponding to those N DNAIs from V-UDR, thereby obtaining the EAS deployment information corresponding to those N DNAIs from V-UDR.

[0266] Optionally, V-NEF can also send an HPLMN ID to V-UDR to indicate which PLMN V-UDR requested EAS deployment information. In this case, V-UDR can further determine whether to return EAS deployment information corresponding to N DNAIs based on the HPLMN ID.

[0267] 609, V-NEF sends a response message to H-NEF.

[0268] The response message includes EAS deployment information corresponding to N DNAIs.

[0269] One possible implementation is that V-NEF sends an Nnef interface EAS deployment notification response (Nnef_EASDeploymnet_Notify response) to H-NEF. This Nnef_EASDeploymnet_Notify response includes EAS deployment information corresponding to N DNAIs.

[0270] 610, H-NEF forwards the response message to H-SMF.

[0271] One possible implementation is that H-NEF sends an Nnef_EASDeploymnet_Notify response to H-SMF, which includes EAS deployment information corresponding to N DNAIs.

[0272] 611. H-SMF determines DNS processing rules based on the EAS deployment information corresponding to N DNAIs.

[0273] After receiving the EAS deployment information corresponding to N DNAIs, H-SMF can determine the DNS processing rules based on the EAS deployment information corresponding to the N DNAIs.

[0274] As an example, DNS processing rules may include one or more of the following information: FQDN range, ECS option, L-DNS server address, and DNS forwarding rules.

[0275] The ECS option can be used to represent the UE's location information.

[0276] DNS forwarding rules, also known as forwarding rules or data plane forwarding rules, are used by H-EASDF to process DNS messages from the UE. For example, when the FQDN in a DNS query sent by the UE matches the FQDN range in the DNS processing rules, H-EASDF adds an ECS option to the DNS query based on the DNS forwarding rules. As another example, when the FQDN in a DNS query sent by the UE matches the FQDN range in the DNS processing rules, H-EASDF forwards the DNS query (such as the DNS query with the added ECS option) to the L-DNS server based on the DNS forwarding rules.

[0277] For relevant schemes regarding DNS processing rules, existing technologies can be referenced, and the embodiments of this application do not limit them.

[0278] Optionally, method 600 further includes: H-SMF selecting H-EASDF and sending DNS processing rules to H-EASDF. Specifically, existing procedures can be referenced, and there are no restrictions on this.

[0279] After the above steps and other steps (for details, please refer to the existing session establishment process), the UE can complete the session establishment.

[0280] 612, the UE sends a DNS query to H-EASDF.

[0281] For example, the UE sends the DNS query message to the H-EASDF via the user plane, through the RAN and UPF.

[0282] The DNS query includes the FQDN of the application that the UE wants to access.

[0283] 613. H-EASDF processes DNS queries according to DNS processing rules.

[0284] After receiving a DNS query, H-EASDF can process it according to the DNS processing rules received from H-SMF. For example, if H-EASDF detects that the FQDN contained in the UE's DNS query matches the FQDN contained in the DNS processing rules (or, in other words, the EAS server corresponding to the FQDN in the DNS query is deployed in the VPLMN), then H-EASDF adds an ECS option to the DNS query and sends the DNS query with the added ECS option to the C-DNS server. Alternatively, when the FQDN contained in the DNS query sent by the UE matches the FQDN range in the DNS processing rules, H-EASDF determines the address of the L-DNS server located in the VPLMN according to the DNS processing rules and sends the UE's DNS query to the L-DNS server, allowing the L-DNS server to determine the EAS.

[0285] In this embodiment, assuming the FQDN in the UE's DNS query matches the FQDN range in the DNS processing rules, H-EASDF can add an ECS option to the DNS query and forward it to the C-DNS server. Furthermore, the C-DNS server can send a response, such as a DNS response, to H-EASDF. This DNS response may contain address information, such as the EAS IP address and / or FQDN. After receiving the DNS response, H-EASDF can report the address information contained in the DNS response, such as the EAS IP address and / or FQDN, to H-SMF.

[0286] 614. H-EASDF sends a DNS reporting request to H-SMF.

[0287] The DNS report request includes the EAS IP address and / or FQDN.

[0288] 615. H-SMF sends EAS IP address and / or FQDN to V-SMF.

[0289] One possible implementation is that the H-SMF sends a notification message to the V-SMF, which carries the EAS IP address and / or FQDN.

[0290] 616, V-SMF selects UL CL or BP, and L-PSA.

[0291] Taking the EAS IP address as an example, V-SMF can determine the DNAI based on the received EAS IP address and determine whether the DNAI allows insertion of UL CL or BP; if insertion of UL CL or BP is allowed, V-SMF selects ULCL or BP for the session, as well as L-PSA.

[0292] 617, V-SMF returns an acknowledgment message to H-SMF.

[0293] One possible implementation is that the H-SMF sends a notification ack message to the V-SMF.

[0294] 618. H-SMF sends a DNS reporting response to H-EASDF.

[0295] 619, H-EASDF sends a DNS response to the UE.

[0296] After receiving the DNS reporting response from the H-SMF, the H-EASDF can send a DNS response to the UE.

[0297] Based on the aforementioned method 600, during the HR session establishment process, the V-SMF can determine the DNAIs that the current UE can access based on the UE's location, and, combined with locally configured policy information, determine to open N DNAIs to the H-SMF. After obtaining these N DNAIs, the H-SMF can query the EAS deployment information corresponding to these N DNAIs from the V-UDR through the interaction between the H-NEF and V-NEF. Furthermore, the H-SMF can determine the DNS processing rules based on the EAS deployment information corresponding to the N DNAIs, and the H-EASDF is responsible for processing the DNS query messages from the UE. Thus, local EAS discovery can be achieved in HR roaming scenarios. In addition, the information (N DNAIs) transmitted between the V-SMF and H-SMF is UE-specific (per UE), requiring minimal changes to the interfaces between SMFs.

[0298] Figure 7 This is a schematic flowchart of another communication method 700 provided in this application embodiment. Method 700 can be used to implement a scheme such as method 300. For example, method 700 can be used in a scenario where the V-SMF queries N DNAIs from the V-PCF, and the H-SMF obtains EAS deployment information corresponding to the N DNAIs from the VPLMN. Method 700 can... Figure 4 The architecture implementation is shown. As an example, method 700 may include the following steps.

[0299] 701, V-UDR stores EAS deployment information in VPLMN.

[0300] For EAS deployment information, please refer to the previous terminology explanation; it will not be repeated here.

[0301] 702, the UE sends a session establishment request message to the V-SMF.

[0302] Step 702 is similar to step 603, and will not be described again here.

[0303] 703, V-SMF identifies M DNAIs.

[0304] One possible implementation is that V-SMF determines the M DNAIs that the UE can access at its current location (represented by TAI) based on S-NSSAI and DNN.

[0305] 704, V-SMF sends a query message to V-PCF.

[0306] The query message includes M DNAIs, and is used to find the DNAI among the M DNAIs that can be opened to HPLMN (or H-SMF). Optionally, the query message also includes an HPLMN ID, which is used to identify the HPLMN.

[0307] One possible implementation involves the V-SMF sending an EAS Policy Request to the V-PCF. This EAS Policy Request includes the HPLMN ID and M DNAIs. The EAS Policy Request is used to request the V-PCF to determine which DNAIs can be made available to the HPLMN. For details, please refer to the description of the third possible implementation in method 300; it will not be repeated here.

[0308] 705, V-PCF sends a query response message to V-SMF.

[0309] One possible implementation is that the V-PCF sends an EAS Policy Response to the V-SMF. This EAS Policy Response includes N DNAIs, which are the DNAIs that are open to HPLMN from among the M DNAIs.

[0310] 706, V-SMF sends N DNAIs to H-SMF.

[0311] 707, H-SMF sends a request message to H-NEF.

[0312] 708, H-NEF sends a request message to V-NEF.

[0313] 709. V-NEF obtains EAS deployment information corresponding to N DNAIs from V-UDR.

[0314] 710, V-NEF sends a response message to H-NEF.

[0315] 711, H-NEF forwards the response message to H-SMF.

[0316] 712. H-SMF determines DNS processing rules based on the EAS deployment information corresponding to N DNAIs.

[0317] 713, the UE sends a DNS query to H-EASDF.

[0318] 714. H-EASDF processes DNS queries according to DNS processing rules.

[0319] 715, H-EASDF sends a DNS report request to H-SMF.

[0320] 716. H-SMF sends EAS IP address and / or FQDN to V-SMF.

[0321] 717, V-SMF selects UL CL or BP, and L-PSA.

[0322] 718, V-SMF returns an acknowledgment message to H-SMF.

[0323] 719, H-SMF sends a DNS report response to H-EASDF.

[0324] 720, H-EASDF sends a DNS response to the UE.

[0325] Steps 706-720 are similar to steps 605-619, and will not be described again here.

[0326] Based on the aforementioned method 700, during the HR session establishment process, the V-SMF can determine the DNAIs that the current UE can access based on the UE's location, and request the V-PCF to determine which DNAIs among those accessible to the current UE can be opened to the H-SMF. After obtaining N DNAIs, the H-SMF can query the V-UDR to obtain the EAS deployment information corresponding to these N DNAIs through the interaction between the H-NEF and V-NEF. Furthermore, the H-SMF can determine the DNS processing rules based on the EAS deployment information corresponding to the N DNAIs, and the H-EASDF is responsible for processing the DNS query messages from the UE, thereby enabling the discovery of local EAS in HR roaming scenarios. In addition, the information (N DNAIs) transmitted between the V-SMF and H-SMF is per UE, requiring minimal changes to the interfaces between SMFs.

[0327] Figure 8 This is a schematic flowchart of another communication method 800 provided in this application embodiment. Method 800 can be used to implement a scheme such as method 300. For example, method 800 can be used in a scenario where the V-SMF determines N DNAIs according to a local policy, and the H-SMF obtains the EAS deployment information corresponding to the N DNAIs from the HPLMN. Method 800 can... Figure 5 The architecture implementation is shown. As an example, method 800 may include the following steps.

[0328] 801, V-SMF local configuration policy information.

[0329] The strategy information can be used to indicate which DNAIs within a VPLMN can be opened to other PLMNs. For details on the strategy information, please refer to the relevant description in Method 300 above; it will not be repeated here.

[0330] 802, H-UDR stores EAS deployment information in VPLMN.

[0331] One possible implementation is that the AF in the VPLMN sends the EAS deployment information of the VPLMN to the H-UDR; the H-UDR receives the EAS deployment information from the VPLMN and stores it. For example, the AF in the VPLMN sends the EAS deployment information from the VPLMN to the V-NEF; after receiving the EAS deployment information from the VPLMN, the V-NEF sends the EAS deployment information from the VPLMN to the H-NEF; after receiving the EAS deployment information from the VPLMN, the H-NEF sends the EAS deployment information from the VPLMN to the H-UDR; the H-UDR receives the EAS deployment information from the VPLMN and stores it.

[0332] In this embodiment, the H-UDR can store EAS deployment information in the VPLMN, such as EAS deployment information corresponding to each DNAI in the VPLMN, or EAS deployment information corresponding to DNAIs in the VPLMN that are allowed to be opened to other PLMNs, without limitation.

[0333] 803, the UE sends a session establishment request message to the V-SMF.

[0334] 804, V-SMF determines N DNAIs based on policy information and the UE's location.

[0335] 805, V-SMF sends N DNAIs to H-SMF.

[0336] 806, H-SMF sends a request message to H-NEF.

[0337] Steps 803-806 are similar to steps 603-606, and will not be described again here.

[0338] 807, H-NEF sends a query message to H-UDR.

[0339] The query message includes N DNAIs, and is used to query the EAS deployment information corresponding to the N DNAIs.

[0340] Optionally, the query message may also include a VPLMN ID, which H-UDR uses to identify the VPLMN.

[0341] In this embodiment of the application, H-UDR can store the EAS deployment information of VPLMN. Therefore, H-NEF can directly query H-UDR for the EAS deployment information corresponding to N DNAIs.

[0342] 808, H-UDR sends a query response message to H-NEF.

[0343] The query response message includes EAS deployment information corresponding to N DNAIs.

[0344] 809. H-NEF sends EAS deployment information corresponding to N DNAIs to H-SMF.

[0345] 810. H-SMF determines DNS processing rules based on the EAS deployment information corresponding to N DNAIs.

[0346] 811, the UE sends a DNS query to H-EASDF.

[0347] 812, H-EASDF processes DNS queries according to DNS processing rules.

[0348] 813, H-EASDF sends a DNS report request to H-SMF.

[0349] 814, H-SMF sends EAS IP address and / or FQDN to V-SMF.

[0350] 815, V-SMF selects UL CL or BP, and L-PSA.

[0351] 816, V-SMF returns an acknowledgment message to H-SMF.

[0352] 817, H-SMF sends a DNS report response to H-EASDF.

[0353] 818, H-EASDF sends a DNS response to the UE.

[0354] Steps 810-818 are similar to steps 611-619, and will not be described again here.

[0355] Based on the aforementioned method 800, during the HR session establishment process, the V-SMF can determine the DNAIs that the current UE can access based on the UE's location, and, in conjunction with locally configured policy information, determine to open N DNAIs to the H-SMF. After obtaining these N DNAIs, the H-SMF can query the EAS deployment information corresponding to these N DNAIs from the H-UDR. Furthermore, the H-SMF can determine DNS processing rules based on the EAS deployment information corresponding to the N DNAIs, and the H-EASDF is responsible for processing DNS query messages from the UE, thereby enabling the discovery of local EAS in HR roaming scenarios. In addition, the information (N DNAIs) transmitted between the V-SMF and H-SMF is per UE, requiring minimal changes to the interface between SMFs.

[0356] Figure 9 This is a schematic flowchart of another communication method 900 provided in this application embodiment. Method 900 can be used to implement a scheme such as method 300. For example, method 900 can be used in a scenario where the V-SMF queries N DNAIs from the V-PCF, and the H-SMF obtains EAS deployment information corresponding to the N DNAIs from the HPLMN. Method 900 can... Figure 5 The architecture shown is implemented. Method 900 may include the following steps.

[0357] 901, H-UDR stores EAS deployment information in VPLMN.

[0358] 902, the UE sends a session establishment request message to the V-SMF.

[0359] Steps 901-902 are similar to steps 802-803, and will not be described again here.

[0360] 903, V-SMF identifies M DNAIs.

[0361] One possible implementation is that V-SMF determines the M DNAIs that the UE can access at its current location (represented by TAI) based on S-NSSAI and DNN.

[0362] 904, V-SMF sends a query message to V-PCF.

[0363] 905, V-PCF sends a query response message to V-SMF.

[0364] Steps 904-905 are similar to steps 704-705, and will not be described again here.

[0365] 906, V-SMF sends N DNAIs to H-SMF.

[0366] 907, H-SMF sends a request message to H-NEF.

[0367] 908, H-NEF sends a query message to H-UDR.

[0368] 909, H-UDR sends a query response message to H-NEF.

[0369] 910, H-NEF sends N EAS deployment information corresponding to DNAI to H-SMF.

[0370] 911. H-SMF determines DNS processing rules based on the EAS deployment information corresponding to N DNAIs.

[0371] 912, the UE sends a DNS query to H-EASDF.

[0372] 913, H-EASDF processes DNS queries according to DNS processing rules.

[0373] 914, H-EASDF sends a DNS report request to H-SMF.

[0374] 915, H-SMF sends EAS IP address and / or FQDN to V-SMF.

[0375] 916, V-SMF selects UL CL or BP, and L-PSA.

[0376] 917, V-SMF returns an acknowledgment message to H-SMF.

[0377] 918, H-SMF sends a DNS report response to H-EASDF.

[0378] 919, H-EASDF sends a DNS response to the UE.

[0379] Steps 906-919 are similar to steps 805-818, and will not be described again here.

[0380] Based on the aforementioned method 900, during the HR session establishment process, the V-SMF can determine the DNAIs that the current UE can access based on the UE's location, and request the V-PCF to determine which DNAIs among those accessible to the current UE can be opened to the H-SMF. After obtaining N DNAIs, the H-SMF can query the EAS deployment information corresponding to these N DNAIs from the H-UDR. Furthermore, the H-SMF can determine the DNS processing rules based on the EAS deployment information corresponding to the N DNAIs, and the H-EASDF is responsible for processing the DNS query messages from the UE, thereby enabling the discovery of local EAS in HR roaming scenarios. In addition, the information (N DNAIs) transmitted between the V-SMF and H-SMF is per UE, requiring minimal changes to the interface between SMFs.

[0381] It is understood that in the embodiments of this application... Figures 4 to 9 The examples provided are merely to facilitate understanding of the embodiments of this application by those skilled in the art, and are not intended to limit the embodiments of this application to the specific scenarios illustrated. Figures 4 to 9 The examples above clearly allow for various equivalent modifications or variations, and such modifications or variations also fall within the scope of the embodiments of this application. For example, the above... Figures 6 to 9 The session establishment process can also be replaced with a session modification process. For example, the above... Figures 4 to 9 The ECS option in the DNS query can also be replaced with the L-DNS server address. Correspondingly, adding the ECS option to the DNS query can be replaced with forwarding the DNS query to the L-DNS server. For example, the above... Figures 4 to 9 It can also include more network elements or devices.

[0382] It is also understood that the message names involved in some of the above embodiments, such as Nsmf_PDUSession_Update Request message, Nsmf_PDUSession_Create Request, query message, etc., are merely examples and do not limit the scope of protection of the embodiments of this application. For example, a query message can also be replaced with a request message.

[0383] It is also understood that the sending of messages is mentioned multiple times in some of the above embodiments. Taking A sending a message to B as an example, A sending a message to B can include A sending a message directly to B, or it can include A sending a message to B through other devices or network elements, and there is no limitation on this.

[0384] It is also understood that, in the embodiments of this application, local EAS discovery is mentioned many times. It is understood that, unless otherwise specified, local EAS discovery means discovering the EAS of the visited network (such as VPLMN).

[0385] It is also understood that in some of the above embodiments, the location of the terminal device is mainly represented by TAI as an example for illustrative purposes, and this is not intended to be limiting. TAI can be replaced with other information that can represent (or reflect) the location of the terminal device.

[0386] It is also understood that some optional features in the various embodiments of this application may not depend on other features in some scenarios, or may be combined with other features in some scenarios, without limitation.

[0387] It is also understood that the solutions in the various embodiments of this application can be used in reasonable combinations, and the explanations or descriptions of the various terms appearing in the embodiments can be referenced or explained to each other in the various embodiments, without limitation.

[0388] It should also be understood that the various numerical sequences in the embodiments of this application do not imply the order of execution, but are merely a distinction for the convenience of description, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0389] It can also be understood that the methods and operations implemented by the device in the above-described method embodiments can also be implemented by components of the device (such as chips or circuits).

[0390] Corresponding to the methods described in the above embodiments, this application also provides corresponding apparatuses, which include modules for executing the methods described above. These modules can be software, hardware, or a combination of both. It is understood that the technical features described in the above method embodiments are also applicable to the following apparatus embodiments.

[0391] Figure 10 This is a schematic diagram of a communication device 1000 provided in an embodiment of this application. The device 1000 includes a transceiver unit 1010 and a processing unit 1020. The transceiver unit 1010 can be used to implement corresponding communication functions. The transceiver unit 1010 can also be referred to as a communication interface or a communication unit. The processing unit 1020 can be used to implement corresponding processing functions, such as determining first information, or determining the deployment information of the EAS corresponding to the first information.

[0392] Optionally, the device 1000 further includes a storage unit, which can be used to store instructions and / or data. The processing unit 1020 can read the instructions and / or data in the storage unit so that the device can perform the operation of the device or network element in the aforementioned method embodiments.

[0393] In the first design, the device 1000 can be a session management network element (such as H-SMF) in the home network as described in the foregoing embodiments, or it can be a component (such as a chip) of the session management network element in the home network. The device 1000 can implement the steps or processes corresponding to those executed by the session management network element in the home network in the above method embodiments. The transceiver unit 1010 can be used to perform transceiver-related operations of the session management network element in the home network in the above method embodiments, and the processing unit 1020 can be used to perform processing-related operations of the session management network element in the home network in the above method embodiments.

[0394] In one possible implementation, the transceiver unit 1010 is configured to receive first information corresponding to the terminal device from the session management network element in the visited network, the first information being used to indicate the deployment location of the edge application server (EAS) in the visited network; the receiving unit 1010 is further configured to obtain EAS deployment information corresponding to the first information based on the first information.

[0395] For example, the first information corresponding to the terminal device includes: the first information is determined based on the location of the terminal device.

[0396] For example, the first information is determined based on the location of the terminal device and includes: the first information is used to indicate: among the deployment locations of EAS determined based on the location of the terminal device, the deployment locations of EAS that the terminal device is allowed to access.

[0397] Optionally, the transceiver unit 1010 is specifically used to send a request message to a data management network element in the home network, the request message including first information, the request message being used to request the EAS deployment information corresponding to the first information; and to receive the EAS deployment information corresponding to the first information from the data management network element in the home network.

[0398] Optionally, the transceiver unit 1010 is specifically used to send a request message to a data management network element in the visited network, the request message including first information, the request message being used to request the EAS deployment information corresponding to the first information; and to receive the EAS deployment information corresponding to the first information from the data management network element in the visited network.

[0399] For example, the request message may also include an identifier of the network to be visited.

[0400] Optionally, the processing unit 1020 is used to determine the Domain Name System (DNS) processing rules based on the EAS deployment information corresponding to the first information, and the DNS processing rules are used to process DNS messages.

[0401] Optionally, the transceiver unit 1010 is also configured to receive the identifier of the visited network from the session management network element in the visited network.

[0402] In the second design, the device 1000 can be a session management network element (such as V-SMF) in the visited network of the aforementioned embodiments, or it can be a component (such as a chip) of the session management network element in the visited network. The device 1000 can implement the steps or processes corresponding to those executed by the session management network element in the visited network of the above method embodiments. The transceiver unit 1010 can be used to execute the transceiver-related operations of the session management network element in the visited network of the above method embodiments, and the processing unit 1020 can be used to execute the processing-related operations of the session management network element in the visited network of the above method embodiments.

[0403] In one possible implementation, the processing unit 1020 is used to determine the first information corresponding to the terminal device based on the location of the terminal device, and the first information is used to indicate the deployment location of the edge application server (EAS) in the visited network; the transceiver unit 1010 is used to send the first information to the session management network element in the home network.

[0404] For example, the first information is used to obtain the EAS deployment information corresponding to the first information.

[0405] Optionally, the first information is used to indicate: among the deployment locations of EAS determined according to the location of the terminal device, the deployment locations of EAS that the terminal device is allowed to access; the processing unit 1020 is specifically used to determine the first information corresponding to the terminal device according to the location and policy information of the terminal device, wherein the policy information is used to indicate the deployment locations of EAS that the visited network is allowed to send to the home network.

[0406] Optionally, the first information is used to indicate: among the EAS deployment locations determined based on the location of the terminal device, the deployment location of the EAS that the terminal device is allowed to access; the processing unit 1020 is specifically used to determine the second information corresponding to the terminal device based on the location of the terminal device; the transceiver unit 1010 is further used to send a request message to the policy control network element in the visited network, the request message including the second information, the request message being used to request permission for the visited network to send the deployment location of the EAS to the home network; and to receive the first information from the policy control network element in the visited network, the first information being determined based on the second information.

[0407] Optionally, the transceiver unit 1010 is also used to send the identifier of the visited network to the session management network element in the home network.

[0408] In the third design, the device 1000 can be a data management network element (such as H-UDR) in the home network of the aforementioned embodiments, or it can be a component (such as a chip) of the data management network element in the home network of the visited network. The device 1000 can implement the steps or processes corresponding to those executed by the data management network element in the home network of the above method embodiments. Specifically, the transceiver unit 1010 can be used to execute transceiver-related operations of the data management network element in the home network of the above method embodiments, and the processing unit 1020 can be used to execute processing-related operations of the data management network element in the home network of the above method embodiments.

[0409] In one possible implementation, the transceiver unit 1010 is configured to receive a request message from a session management network element in the home network. The request message includes first information corresponding to the terminal device. The first information is used to indicate the deployment location of the edge application server (EAS) in the visited network. The request message is used to request the EAS deployment information corresponding to the first information. The transceiver unit 1010 is also configured to send the EAS deployment information corresponding to the first information to the session management network element in the home network.

[0410] Optionally, the request message may also include the identifier of the visited network; the processing unit 1020 is used to determine the EAS deployment information corresponding to the first information based on the identifier of the visited network and the first information.

[0411] Optionally, the processing unit 1020 is used to locally store the EAS deployment information corresponding to the first information.

[0412] It should be understood that the specific process of each unit performing the above-mentioned corresponding steps has been described in detail in the above-mentioned method embodiments, and will not be repeated here for the sake of brevity.

[0413] It should also be understood that the device 1000 here is embodied in the form of a functional unit. The term "unit" here can refer to an application-specific integrated circuit (ASIC), electronic circuitry, a processor (e.g., a shared processor, a proprietary processor, or a group processor, etc.) and memory for executing one or more software or firmware programs, combined logic circuitry, and / or other suitable components supporting the described functions. In an alternative example, those skilled in the art will understand that the device 1000 may be specifically a session management network element (such as a session management network element in a home network, or a session management network element in a visited network) in the above embodiments, and may be used to execute the various processes and / or steps corresponding to the session management network element in the above method embodiments; or, the device 1000 may be specifically a network open network element (such as a network open network element in a home network) in the above embodiments, and may be used to execute the various processes and / or steps corresponding to the network open network element in the above method embodiments; or, the device 1000 may be specifically a data management network element (such as a data management network element in a home network) in the above embodiments, and may be used to execute the various processes and / or steps corresponding to the data management network element in the above method embodiments. To avoid repetition, further details are omitted here.

[0414] The apparatus 1000 of each of the above schemes has the function of implementing the corresponding steps performed by the network elements (such as session management network elements (such as session management network elements in the home network, or session management network elements in the visited network), or network open network elements, or data management network elements) in the above methods. The functions can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions; for example, the transceiver unit can be replaced by a transceiver (e.g., the sending unit in the transceiver unit can be replaced by a transmitter, and the receiving unit in the transceiver unit can be replaced by a receiver), and other units, such as processing units, can be replaced by processors, respectively executing the transceiver operations and related processing operations in each method embodiment.

[0415] In addition, the transceiver unit 1010 may also be a transceiver circuit (for example, it may include a receiving circuit and a transmitting circuit), and the processing unit may be a processing circuit.

[0416] It should be pointed out that, Figure 10 The device mentioned can be the network element or equipment in the foregoing embodiments, or it can be a chip or chip system, such as a system on chip (SoC). The transceiver unit can be an input / output circuit or a communication interface; the processing unit is a processor, microprocessor, or integrated circuit integrated on the chip. No limitations are imposed here.

[0417] Figure 11 This is a schematic diagram of another communication apparatus 1100 provided in an embodiment of this application. The apparatus 1100 includes a processor 1110, which is used to execute computer programs or instructions stored in a memory 1120, or to read data / signaling stored in the memory 1120, to perform the methods in the above-described method embodiments. Optionally, there may be one or more processors 1110.

[0418] Optionally, such as Figure 11 As shown, the device 1100 also includes a memory 1120 for storing computer programs or instructions and / or data. The memory 1120 may be integrated with the processor 1110 or may be disposed separately. Optionally, there may be one or more memories 1120.

[0419] Optionally, such as Figure 11 As shown, the device 1100 also includes a transceiver 1130, which is used for receiving and / or transmitting signals. For example, the processor 1110 is used to control the transceiver 1130 to receive and / or transmit signals.

[0420] As one approach, the device 1100 is used to implement the operations performed by the session management network element in the various method embodiments described above.

[0421] For example, processor 1110 is used to execute computer programs or instructions stored in memory 1120 to implement relevant operations of session management network elements in the home network in the various method embodiments described above. For example, Figure 3 The method executed by the session management network element in the home network in the illustrated embodiment, or Figures 4 to 9 The method executed by H-SMF in any of the illustrated embodiments.

[0422] For example, processor 1110 is used to execute computer programs or instructions stored in memory 1120 to implement related operations of session management network elements in the visited network in the various method embodiments described above. For example, Figure 3 The method executed by the session management network element in the visited network in the illustrated embodiment, or Figures 4 to 9 The method of V-SMF execution in any of the illustrated embodiments.

[0423] As an alternative, the device 1100 is used to implement the operations performed by the network open element in the various method embodiments described above.

[0424] For example, processor 1110 is used to execute computer programs or instructions stored in memory 1120 to implement relevant operations of network open network elements in the home network in the various method embodiments described above. For example, Figure 3 The method executed by the network open network element in the home network in the illustrated embodiment, or Figures 4 to 9 The method executed by H-NEF in any of the illustrated embodiments.

[0425] As an alternative, the device 1100 is used to implement the operations performed by the data management network element in the various method embodiments described above.

[0426] For example, processor 1110 is used to execute computer programs or instructions stored in memory 1120 to implement relevant operations of data management network elements in the home network in the various method embodiments described above. For example, Figure 3 The method executed by the data management network element in the home network in the illustrated embodiment, or Figures 4 to 9 The method of H-UDR execution in any of the illustrated embodiments.

[0427] It should be understood that the processor mentioned in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0428] It should also be understood that the memory mentioned in the embodiments of this application can be volatile memory and / or non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM includes the following forms: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0429] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated into the processor.

[0430] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0431] Figure 12 This is a schematic diagram of a chip system 1200 provided in an embodiment of this application. The chip system 1200 (or may also be referred to as a processing system) includes logic circuitry 1210 and an input / output interface 1220.

[0432] The logic circuit 1210 can be a processing circuit in the chip system 1200. The logic circuit 1210 can be coupled to a memory unit, calling instructions from the memory unit, enabling the chip system 1200 to implement the methods and functions of the embodiments of this application. The input / output interface 1220 can be an input / output circuit in the chip system 1200, outputting processed information from the chip system 1200, or inputting data or signaling information to be processed into the chip system 1200 for processing.

[0433] Specifically, for example, if the H-SMF has the chip system 1200 installed, and the logic circuit 1210 is coupled to the input / output interface 1220, the logic circuit 1210 can send a request message through the input / output interface 1220. This request message can be generated by the logic circuit 1210 based on the first information. Alternatively, the input / output interface 1220 can input the first information from the V-SMF to the logic circuit 1210 for processing. As another example, if the V-SMF has the chip system 1200 installed, and the logic circuit 1210 is coupled to the input / output interface 1220, the logic circuit 1210 can send the first information to the H-SMF through the input / output interface 1220. This first information can be generated by the logic circuit 1210.

[0434] As one approach, the chip system 1200 is used to implement the operations performed by the session management network element in the various method embodiments described above.

[0435] For example, logic circuit 1210 is used to implement processing-related operations performed by the session management network element in the home network in the above method embodiment, such as... Figure 3 The operations performed by the session management network element in the home network in the illustrated embodiment are related to processing. Figures 4 to 9 The H-SMF performs processing-related operations in any of the illustrated embodiments; the input / output interface 1220 is used to implement the send and / or receive-related operations performed by the session management element in the home network in the above method embodiments, such as... Figure 3 The transmission and / or reception related operations performed by the session management network element in the home network in the illustrated embodiment, or Figures 4 to 9 The H-SMF in any of the illustrated embodiments performs send and / or receive related operations.

[0436] For example, logic circuit 1210 is used to implement processing-related operations performed by the session management element in the visited network in the above method embodiment, such as... Figure 3 The operations performed by the session management network element in the visited network in the illustrated embodiment are related to processing. Figures 4 to 9The V-SMF performs processing-related operations in any of the illustrated embodiments; the input / output interface 1220 is used to implement send and / or receive-related operations performed by the session management element in the visited network in the above method embodiments, such as... Figure 3 The session management element in the visited network of the illustrated embodiment performs send and / or receive related operations, or Figures 4 to 9 The V-SMF in any of the illustrated embodiments performs transmit and / or receive related operations.

[0437] As an alternative, the chip system 1200 is used to implement the operations performed by the network open elements in the various method embodiments described above.

[0438] For example, logic circuit 1210 is used to implement processing-related operations performed by network open elements in the home network in the above method embodiments, such as... Figure 3 The processing-related operations performed by the network open network element in the home network in the illustrated embodiment, or Figures 4 to 9 The H-NEF in any of the illustrated embodiments performs processing-related operations; the input / output interface 1220 is used to implement the transmission and / or reception-related operations performed by the network open elements in the home network in the above method embodiments, such as... Figure 3 The transmission and / or reception related operations performed by the network open elements in the home network in the illustrated embodiment, or Figures 4 to 9 The H-NEF in any of the illustrated embodiments performs transmission and / or reception-related operations.

[0439] As an alternative, the chip system 1200 is used to implement the operations performed by the data management network element in the various method embodiments described above.

[0440] For example, logic circuit 1210 is used to implement processing-related operations performed by the data management network element in the home network in the above method embodiments, such as... Figure 3 The data management network element in the home network of the illustrated embodiment performs processing-related operations, or Figures 4 to 9 The H-UDR in any of the illustrated embodiments performs processing-related operations; the input / output interface 1220 is used to implement the sending and / or receiving-related operations performed by the data management network element in the home network in the above method embodiments, such as... Figure 3 The data management network element in the home network of the illustrated embodiment performs transmission and / or reception-related operations, or Figures 4 to 9 The H-UDR in any of the illustrated embodiments performs transmission and / or reception-related operations.

[0441] This application also provides a computer-readable storage medium storing computer instructions for implementing the methods executed by the network element in the above-described method embodiments.

[0442] For example, when the computer program is executed by a computer, it enables the computer to implement the methods performed by session management network elements (such as session management network elements in the home network or session management network elements in the visited network) in the various embodiments of the above methods.

[0443] For example, when the computer program is executed by the computer, it enables the computer to implement the methods executed by network open network elements (such as network open network elements in the home network) in the various embodiments of the above methods.

[0444] For example, when the computer program is executed by the computer, it enables the computer to implement the methods executed by the data management network element (such as the data management network element in the home network) in the various embodiments of the above methods.

[0445] This application also provides a computer program product containing instructions that, when executed by a computer, implement the methods described above, which are performed by network elements (such as session management network elements (such as session management network elements in the home network or in the visited network), or network open network elements, or data management network elements).

[0446] This application also provides a communication system, including one or more of the following: a session management network element in the home network, a session management network element in the visited network, a network open network element in the visited network, a network open network element in the home network, a policy control network element, or a data management network element (such as a data management network element in the home network, or a data management network element in the visited network). Optionally, the system also includes a device that communicates with the above-mentioned one or more network elements. For example, the system may also include at least one of the following: a terminal device, an EASDF (such as an EASDF in the home network), etc.

[0447] The explanations and beneficial effects of the relevant contents in any of the devices provided above can be found in the corresponding method embodiments provided above, and will not be repeated here.

[0448] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of apparatus or units may be electrical, mechanical, or other forms.

[0449] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. 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 wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs). For example, the aforementioned available media include, but are not limited to, USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, and other media capable of storing program code.

[0450] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, include: The session management network element in the home network receives first information corresponding to the terminal device from the session management network element in the visited network. The first information is used to indicate the deployment location of the edge application server (EAS) in the visited network, wherein the first information is determined based on the location of the terminal device. The session management network element in the home network obtains the EAS deployment information corresponding to the first information based on the first information.

2. The method according to claim 1, characterized in that, The location of the terminal device includes a tracking area identifier (TAI).

3. The method according to claim 1, characterized in that, The first information is determined based on the location of the terminal device and includes: the first information is used to indicate: among the deployment locations of EAS determined based on the location of the terminal device, the deployment locations of EAS that the terminal device is allowed to access.

4. The method according to any one of claims 1 to 3, characterized in that, The session management network element in the home network obtains the EAS deployment information corresponding to the first information based on the first information, including: The session management network element in the home network sends a request message to the data management network element in the home network. The request message includes the first information and is used to request the EAS deployment information corresponding to the first information. The session management network element in the home network receives the EAS deployment information corresponding to the first information from the data management network element in the home network.

5. The method according to any one of claims 1 to 3, characterized in that, The session management network element in the home network obtains the EAS deployment information corresponding to the first information based on the first information, including: The session management network element in the home network sends a request message to the data management network element in the visited network. The request message includes the first information and is used to request the EAS deployment information corresponding to the first information. The session management element in the home network receives the EAS deployment information corresponding to the first information from the data management element in the visited network.

6. The method according to claim 4, characterized in that, The request message also includes the identifier of the visited network.

7. The method according to claim 5, characterized in that, The request message also includes the identifier of the visited network.

8. The method according to any one of claims 1 to 3, characterized in that, The method further includes: The session management network element in the home network determines the Domain Name System (DNS) processing rules based on the EAS deployment information corresponding to the first information. The DNS processing rules are used to process DNS messages.

9. The method according to any one of claims 1 to 3, characterized in that, The method further includes: The session management element in the home network receives the identifier of the visited network from the session management element in the visited network.

10. A method of communication, characterized in that, include: The session management network element in the visited network determines the first information corresponding to the terminal device based on the location of the terminal device. The first information is used to indicate the deployment location of the edge application server (EAS) in the visited network. The session management element in the visited network sends the first information to the session management element in the home network.

11. The method according to claim 10, characterized in that, The first information is used to obtain the EAS deployment information corresponding to the first information.

12. The method according to claim 10 or 11, characterized in that, The first information is used to indicate: among the EAS deployment locations determined based on the location of the terminal device, the EAS deployment locations that the terminal device is allowed to access; The session management network element in the visited network determines the first information corresponding to the terminal device based on the location of the terminal device, including: The session management network element in the visited network determines the first information corresponding to the terminal device based on the location and policy information of the terminal device, wherein the policy information is used to indicate the deployment location of the EAS that the visited network is allowed to send to the home network.

13. The method according to claim 10 or 11, characterized in that, The first information is used to indicate: among the EAS deployment locations determined based on the location of the terminal device, the EAS deployment locations that the terminal device is allowed to access; The session management network element in the visited network determines the first information corresponding to the terminal device based on the location of the terminal device, including: The session management network element in the visited network determines the second information corresponding to the terminal device based on the location of the terminal device; The session management network element in the visited network sends a request message to the policy control network element in the visited network. The request message includes the second information and is used to request the deployment location of the EAS that the visited network is allowed to send to the home network. The session management element in the visited network receives the first information from the policy control element in the visited network, and the first information is determined based on the second information.

14. The method according to claim 10 or 11, characterized in that, The method further includes: The session management element in the visited network sends the identifier of the visited network to the session management element in the home network.

15. A method of communication, characterized in that, include: The data management network element in the home network receives a request message from the session management network element in the home network. The request message includes first information corresponding to the terminal device. The first information is used to indicate the deployment location of the edge application server (EAS) in the visited network. The request message is used to request the EAS deployment information corresponding to the first information. The first information is determined based on the location of the terminal device. The data management network element in the home network sends the EAS deployment information corresponding to the first information to the session management network element in the home network.

16. The method according to claim 15, characterized in that, The request message also includes the identifier of the visited network, and the method further includes: The data management network element in the home network determines the EAS deployment information corresponding to the first information based on the identifier of the visited network and the first information.

17. The method according to claim 15 or 16, characterized in that, The method further includes: The data management network element in the home network locally stores the EAS deployment information corresponding to the first information.

18. A communication apparatus, characterized in that, The apparatus includes: a unit for performing the method as described in any one of claims 1 to 9, or a unit for performing the method as described in any one of claims 10 to 14, or a unit for performing the method as described in any one of claims 15 to 17.

19. A communication apparatus, characterized in that, include: A processor for executing a computer program stored in a memory to cause the apparatus to perform the method as claimed in any one of claims 1 to 9, or to cause the apparatus to perform the method as claimed in any one of claims 10 to 14, or to cause the apparatus to perform the method as claimed in any one of claims 15 to 17.

20. The apparatus according to claim 19, characterized in that, The device also includes the memory.

21. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1 to 9, or causes the computer to perform the method as described in any one of claims 10 to 14, or causes the computer to perform the method as described in any one of claims 15 to 17.

22. A computer program product, characterized in that, The computer program product includes computer instructions that, when executed on a communication device, cause the communication device to perform the method as described in any one of claims 1 to 9, or the method as described in any one of claims 10 to 14, or the method as described in any one of claims 15 to 17.

23. A communication system, characterized in that, Includes any of the following: A session management network element in the home network, and one or more of the following for communicating with the session management network element in the home network: a data management network element in the home network, a session management network element in the visited network, and a data management network element in the visited network; or, The session management network element in the visited network, and one or more of the following for communicating with the session management network element in the visited network: the session management network element in the home network, and the policy control network element in the visited network; Wherein, the session management network element in the home network is used to perform the method as described in any one of claims 1 to 9, the session management network element in the visited network is used to perform the method as described in any one of claims 10 to 14, and the data management network element in the home network is used to perform the method as described in any one of claims 15 to 17.

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