WO2023213215A1 - 一种通信方法及装置 - Google Patents

一种通信方法及装置 Download PDF

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Publication number
WO2023213215A1
WO2023213215A1 PCT/CN2023/090793 CN2023090793W WO2023213215A1 WO 2023213215 A1 WO2023213215 A1 WO 2023213215A1 CN 2023090793 W CN2023090793 W CN 2023090793W WO 2023213215 A1 WO2023213215 A1 WO 2023213215A1
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WO
WIPO (PCT)
Prior art keywords
network element
visited
session management
management network
home
Prior art date
Application number
PCT/CN2023/090793
Other languages
English (en)
French (fr)
Inventor
陈泽昊
李永翠
倪慧
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
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Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Publication of WO2023213215A1 publication Critical patent/WO2023213215A1/zh

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
    • H04W36/0027—Control or signalling for completing the hand-off for data sessions of end-to-end connection for a plurality of data sessions of end-to-end connections, e.g. multi-call or multi-bearer end-to-end data connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/10—Connection setup
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W80/00—Wireless network protocols or protocol adaptations to wireless operation
    • H04W80/08—Upper layer protocols
    • H04W80/10—Upper layer protocols adapted for application session management, e.g. SIP [Session Initiation Protocol]

Definitions

  • the embodiments of the present application relate to the field of wireless communications, and in particular, to a communication method and device.
  • Edge computing (EC) services often have relatively high latency requirements, so mobile edge computing (MEC) platforms need to be deployed intensively.
  • MEC mobile edge computing
  • a reasonable way is for multiple operators (or third parties) to jointly deploy an MEC platform (ie, edge hosting environment (EHE)), that is to say, an MEC platform with a specific function, or a specific
  • EHE edge hosting environment
  • the service may be deployed by different operators in different locations, or the service may be deployed only on MEC platforms deployed by some operators, or the MEC platform may be deployed by only some operators.
  • This application provides a communication method and device to solve the problem that the MEC platform deploying a certain service does not support PSA access of other operators, which may lead to high latency and/or poor reliability of terminal equipment accessing the service. question.
  • the present application provides a communication method, which method includes: a home session management network element receiving a first session establishment request message, where the first session establishment request message is used to request the establishment of a session of a terminal device; the home session management network element receives a first session establishment request message.
  • the local session management network element determines the visited session management network element; the home session management network element obtains the information of the visited anchor point user plane network element from the visited session management network element.
  • the terminal device can access the service through the visited anchor point user plane network element, so it can improve
  • the reliability of the terminal device's access to the service deployed in the visiting place and the reduction of the delay in accessing the service solve the problem that the edge application server deploying the service (which can be called the first service) does not support the anchor point user plane network element access in the home place. access, resulting in high latency and/or poor reliability for terminal devices to access the service.
  • the information about the visited anchor point user plane network element may be the identity and/or address of the visited anchor point user plane network element.
  • the home session management network element determines the visited session management network element
  • determines the first visited public land mobile network based on the location of the terminal device.
  • the home session management network element obtains the information of the visited session management network element according to the identification of the first visited public land mobile network, and the visited session management network element is deployed in the first visited place Public land mobile network.
  • the home session management network element selects the visited public land mobile network based on the location of the terminal device, and obtains information about the session management network element deployed in the selected visited public land mobile network.
  • the method further includes: the home session management network element obtains the corresponding relationship between the first service and the first visited public land mobile network; the first visited public land mobile network does not support The home user plane network element accesses the first service; when the home session management network element determines the first visited public land mobile network based on the location of the terminal device, the home session management network element determines the first visited public land mobile network based on the location of the terminal device. The corresponding relationship and/or the location of the terminal device determines the first visited public land mobile network.
  • the home session management network element can obtain the corresponding relationship between the service and the visited public land mobile network, and then select the visited public land mobile network based on the corresponding relationship and the location of the terminal device.
  • the home session management network element also obtains first indication information, and the first indication information is used to instruct the first service to pass through the anchor user of the first visited public land mobile network. Network element access.
  • the home session management network element can learn that the first service can only be accessed through the anchor user plane network element of the first visited public land mobile network.
  • the home session management network element when the home session management network element obtains the information of the visited session management network element based on the identification of the first visited public land mobile network, the home session management network The element sends a request message to the network storage function network element, where the request message includes an identifier of the first visited public land mobile network; the identifier of the first visited public land mobile network is used to determine the visited session management Network element: the home session management network element receives a response message from the network storage function network element, where the response message includes information about the visited session management network element.
  • the home session management network element can obtain the information of the visiting session management network element from the network storage function network element.
  • the home session management network element when the home session management network element obtains the information of the visited session management network element based on the identification of the first visited public land mobile network, the home session management network The element sends a request message to the home access and mobility management network element, where the request message includes the identifier of the first visited public land mobile network; the identifier of the first visited public land mobile network is used to determine the The visited session management network element; the home session management network element receives a response message from the home access and mobility management network element, where the response message includes information about the visited session management network element.
  • the home session management network element can obtain the information of the visited session management network element from the network storage function network element through the home access and mobility management network elements.
  • the request message also includes information about the visited user plane network element, and the first visited public land mobile network supports the visited user plane network element to access the first service, The information about the visited user plane network element is used to determine the visited session management network element.
  • the information about the visited user plane network element includes the identity and/or address of the visited user plane network element.
  • the information of the visited user plane network element can assist the network storage function network element to select and manage or control the visited session management network element of the visited user plane network element, thereby realizing the visited user plane network element selection to support access.
  • the method further includes: the home session management network element also sends second indication information to the visited session management network element, and the second indication information instructs the visited session management network element Select the visited anchor point user plane network element and do not select the visited offload point.
  • the method further includes: the home session management network element also sends location information of the terminal device to the visited session management network element, and the location information of the terminal device is used to select the Visits the anchor point user plane network element.
  • the home session management network element sends the location information of the terminal device in the home public land mobile network to the visited session management network element, and the visited session management network element obtains the mapping relationship, and the visited session management network element can obtain the mapping relationship according to The location information of the terminal equipment in the home public land mobile network and the mapping relationship determine the location information of the terminal equipment in the first visited public land mobile network.
  • the mapping relationship indicates a mapping relationship between location information in the home public land mobile network and location information in the first visited public land mobile network.
  • the home session management network element obtains the mapping relationship, and the home session management network element determines that the terminal device is mobile in the first visited public land mobile network based on the location information of the terminal device in the home public land mobile network and the mapping relationship. Location information on the network.
  • the mapping relationship indicates a mapping relationship between location information in the home public land mobile network and location information in the first visited public land mobile network.
  • the home session management network element sends the location information of the terminal device in the first visited public land mobile network to the visited session management network element.
  • the location information of the terminal device is the geographical location information of the terminal device.
  • the latitude and longitude information of the terminal device are the geographical location information of the terminal device.
  • the method further includes: the home session management network element also sends an identifier of the first service to the visited session management network element, and the identifier of the first service is used to select support for access. Enter the visited anchor point user plane network element of the first service.
  • the method further includes: the home session management network element sending a offloading rule to the home offloading point, the offloading rule indicating that the report of the address range corresponding to the first visited public land mobile network will be The traffic is diverted to the user plane network element of the visited anchor point.
  • the present application provides a communication method.
  • the method includes: a home session management network element receiving an identifier of a first service that a terminal device requests to access; and the home session management network element responding to the identification of the first service by The identification, and the corresponding relationship between the first service and the first visited public land mobile network determine the visited session management network element, and the visited session management network element is deployed in the first visited public land mobile network, so The first visited public land mobile network does not support the home user plane network element to access the first service; the home session management network element obtains the visited anchor point user plane network from the visited session management network element Yuan information.
  • the visited session management network element and the visited anchor point user plane network element for the terminal device when it accesses the service deployed in the visited place (which can be called the first service), and then the terminal device can access the service through the visited place.
  • the ground anchor user plane network element accesses the service, which can improve the reliability of the terminal device accessing the service and reduce the delay of accessing the service. This solves the problem that the edge application server deploying the service does not support the home anchor user plane. Network element access leads to problems such as high latency and/or poor reliability for terminal devices to access the service.
  • the home session management network element determines the visited session management network based on the identification of the first service and the corresponding relationship between the first service and the first visited public land mobile network. At this time, the home session management network element determines the first visited public land mobile network based on the identification of the first service and the corresponding relationship between the first service and the first visited public land mobile network. Network; the home session management network The information of the visited session management network element is obtained according to the identification of the first visited public land mobile network.
  • the home session management network element can learn the visited public land mobile network corresponding to the first service, and obtain information about the session management network elements deployed in the visited public land mobile network.
  • the home session management network element when the home session management network element obtains the information of the visited session management network element based on the identification of the first visited public land mobile network, the home session management network The element sends a request message to the network storage function network element, where the request message includes an identifier of the first visited public land mobile network; the identifier of the first visited public land mobile network is used to determine the visited session management Network element: the home session management network element receives a response message from the network storage function network element, where the response message includes information about the visited session management network element.
  • the home session management network element can obtain the information of the visiting session management network element from the network storage function network element.
  • the home session management network element when the home session management network element obtains the information of the visited session management network element based on the identification of the first visited public land mobile network, the home session management network The element sends a request message to the home access and mobility management network element, where the request message includes the identifier of the first visited public land mobile network; the identifier of the first visited public land mobile network is used to determine the The visited session management network element; the home session management network element receives a response message from the home access and mobility management network element, where the response message includes information about the visited session management network element.
  • the home session management network element can obtain the information of the visited session management network element from the network storage function network element through the home access and mobility management network elements.
  • the request message also includes information about the visited user plane network element, and the first visited public land mobile network supports the visited user plane network element to access the first service, The information about the visited user plane network element is used to determine the visited session management network element.
  • the information of the visited user plane network element can assist the network storage function network element to select and manage or control the visited session management network element of the visited user plane network element, thereby realizing the visited user plane network element selection to support access.
  • the anchor user plane network element visited by the first service can assist the network storage function network element to select and manage or control the visited session management network element of the visited user plane network element, thereby realizing the visited user plane network element selection to support access.
  • the home session management network element obtains the address of the edge application server; the home session management network element sends the address of the edge application server to the visited session management network element, so The address of the edge application server is used to select the visited anchor point user plane network element.
  • the home session management network element also sends instruction information to the visited session management network element, and the instruction information instructs the visited session management network element to select the visited anchor point.
  • User plane network elements do not select the visited distribution point.
  • the home session management network element also sends location information of the terminal device to the visited session management network element, and the location information of the terminal device is used to select the visited anchor. Click on the user plane network element.
  • the home session management network element also sends an identifier of the first service to the visited session management network element, and the identifier of the first service is used to select to support access to the The anchor user plane network element visited by the first service.
  • the The home session management network element after the home session management network element determines the visited session management network element and before obtaining the information of the visited anchor point user plane network element from the visited session management network element, the The home session management network element sends the information of the visited session management network element to the home access and mobility management network element, and the information of the visited session management network element is used to establish the terminal device. session.
  • the home access and mobility management network element can select the home session management network element and the visited session management network element to establish a new session, that is, the first session.
  • the home session management network element determines the visited session management network element and before obtaining the information of the visited anchor point user plane network element from the visited session management network element, the The home session management network element sends a session modification instruction to the home access and mobility management network element, where the session modification instruction is used to instruct the establishment of the first session; the home session management network element sends a session modification instruction from the home access and mobility management network element.
  • the local access and mobility management network element receives a session management context message used to create the first session, where the session management context message used to create the first session includes an identification of the second session, and the The second session is a session previously established by the terminal device with the home session management network element; the home session management network element is based on the identifier of the second session, and the identifier of the second session and the The corresponding relationship between the information of the visited session management network element determines the information of the visited session management network element. Wherein, the corresponding relationship between the identifier of the second session and the identifier of the visited session management network element is stored in the context of the second session.
  • the home session management network element determines that the new session (ie, the first session) to be established needs to select the visited session management network element in the old session (ie, the second session).
  • the present application provides a communication method, which method includes: the visited session management network element receives a first message from the home session management network element, where the first message is used to request or modify the establishment of a session of the terminal device; The visited session management network element selects a visited anchor user plane network element for the session; the visited session management network element sends the visited anchor user plane network element to the home session management network element. Information.
  • the visited session management network element selects the visited anchor user plane network element for the session, and then the terminal device can access the service through the visited anchor user plane network element. Therefore, it can improve the efficiency of the terminal device accessing the visited place deployment. The reliability of the service and the reduction of the delay in accessing the service. Moreover, the visited session management network element does not select the visited offloading point for the session, but the home session management network element selects the home offloading point. In this way, the session can carry a variety of services, including mobile services on the home public land.
  • the network deployment business also includes the business of public land mobile network deployment at the place of visit.
  • the visited session management network element selects the visited anchor point user plane network element and does not select the visited offload point.
  • the visited session management network element receives indication information from the home session management network element, and the indication information instructs the visited session management network element to select a visited anchor user plane network. element, do not select the visited offloading point; when the visited session management network element selects the visited anchor point user plane network element for the session, the visited session management network element selects the visited based on the indication information.
  • the ground anchor point user plane network element does not choose to visit the distribution point.
  • the visited session management network element receives an identifier of the first service from the home session management network element; and the visited session management network element selects a visited anchor point for the session.
  • the visited session management network element selects the visited anchor point user plane network element according to the identifier of the first service, wherein the visited anchor point user plane network element is a user plane network element that supports access.
  • the visited anchor point user plane network element of the first service is a user plane network element that supports access.
  • the visited session management network element receives the address of the edge application server from the home session management network element; and the visited session management network element selects a visited location for the session.
  • the visited session management network element selects the visited anchor user plane network element according to the address of the edge application server, wherein the visited anchor user plane network element is a supporting Access the visited anchor point user plane network element of the edge application server.
  • the visited session management network element receives location information of the terminal device from the home session management network element; and the visited session management network element selects a visited location for the session.
  • the visited session management network element selects the visited anchor user plane network element based on the location information of the terminal device.
  • this application provides a communication method, which method includes:
  • the home access and mobility management network element receives a session establishment request message from the terminal device.
  • the session establishment request message includes an identifier of a second session.
  • the second session is the terminal device's previous communication with the home session management network element.
  • the established session; the home access and mobility management network element determines the home session management network element and the visited session management network element according to the identifier of the second session.
  • the home access and mobility management network element can determine the home session management network element and the visited session management network element according to the identifier of the second session, and create a new session for the terminal device.
  • the home access and mobility management network element determines the visited session management network element
  • the home access and mobility management network element obtains the information from the home session management network element.
  • the home access and mobility management network element receives the information of the visited session management network element from the network storage function network element.
  • the home access and mobility management network elements can obtain the information of the visited session management network element in different ways.
  • this application also provides a device.
  • the device can perform the above method design.
  • the device may be a chip or circuit capable of performing the functions corresponding to the above methods, or a device including the chip or circuit.
  • the device includes: a memory for storing computer executable program code; and a processor, the processor is coupled to the memory.
  • the program code stored in the memory includes instructions, and when the processor executes the instructions, the device or the device installed with the device executes the method in any of the above possible designs.
  • the device may further include a communication interface, which may be a transceiver, or, if the device is a chip or a circuit, the communication interface may be an input/output interface of the chip, such as an input/output pin, etc.
  • a communication interface which may be a transceiver, or, if the device is a chip or a circuit, the communication interface may be an input/output interface of the chip, such as an input/output pin, etc.
  • the device includes corresponding functional units, respectively used to implement the steps in the above method.
  • Functions can be implemented by hardware, or by hardware executing corresponding software.
  • Hardware or software includes one or more units corresponding to the above functions.
  • the present application provides a computer-readable storage medium that stores a computer program.
  • the computer program When the computer program is run on a device, the method in any of the above possible designs is executed.
  • the present application provides a computer program product.
  • the computer program product includes a computer program.
  • the computer program is run on a device, the method in any of the above possible designs is executed.
  • the present application provides a communication system, which includes one or more of a device for performing the second aspect, a terminal device, and/or a device for performing the fourth aspect.
  • Figure 1 is a schematic diagram of the architecture of the mobile communication system applied in this application.
  • FIG. 2 is a schematic diagram of the three forms of UPF applied in this application.
  • Figure 3 is a schematic diagram of a possible application scenario in this application.
  • Figure 4 is a schematic diagram of another possible application scenario in this application.
  • Figure 5 is a schematic diagram of terminal equipment 1 and terminal equipment 2 accessing service X in this application;
  • Figure 6 is one of the overview flow charts of a communication method in this application.
  • Figure 7 is a schematic diagram of selecting V-SMF and V-PSA during the session establishment process in this application;
  • Figure 8 is the second overview flow chart of a communication method in this application.
  • Figure 9 is a schematic diagram of selecting V-SMF and V-PSA when the UE accesses service 1 in scenario 1 in this application;
  • Figure 10 is a schematic diagram of selecting V-SMF and V-PSA when the UE accesses service 1 in sub-scenario 1 in this application;
  • Figure 11 is a schematic diagram of selecting V-SMF and V-PSA when the UE accesses service 1 in sub-scenario 2 in this application;
  • Figure 12 is a schematic diagram of selecting V-SMF and V-PSA when the UE accesses service 1 in sub-scenario 3 in this application;
  • Figure 13 is one of the structural schematic diagrams of a communication device in this application.
  • Figure 14 is the second structural schematic diagram of a communication device in this application.
  • At least one of a, b, or c can mean: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c can be single or multiple .
  • FIG. 1 is a schematic architectural diagram of a mobile communication system applied in an embodiment of the present application.
  • the communication system includes terminal equipment (for example, user equipment (UE)), network equipment (for example, access network (AN) equipment or radio access network (AN) equipment, below) Taking RAN as an example to illustrate), core network (Core network, CN), and data network (data network, DN).
  • UE user equipment
  • AN access network
  • AN radio access network
  • DN data network
  • the network elements of the core network can be divided into two parts: the user plane and the control plane.
  • the control plane is responsible for the management of the mobile network
  • the user plane is responsible for the transmission of service data.
  • the terminal device is the entrance for mobile users to interact with the network. It can provide basic computing capabilities and storage capabilities, display business windows to users, and receive user operation inputs.
  • Next-generation terminal equipment NextGen UE
  • NextGen UE can use new air interface technology to establish signal connections and data connections with the RAN to transmit control signals and business data to the mobile network.
  • Terminal devices may include various handheld devices with wireless communication functions, vehicle-mounted devices, wearable devices, computing devices or other processing devices connected to wireless modems, as well as various forms of terminals, mobile stations (MS), terminals (terminal), soft terminal, etc., such as water meters, electricity meters, sensors, etc.
  • RAN Deployed close to terminal equipment, it provides network access functions for authorized users in specific areas, and can determine transmission tunnels of different qualities to transmit user data based on user levels, business needs, etc.
  • RAN can manage its own resources, utilize them rationally, provide access services to terminal devices on demand, and is responsible for forwarding control signals and user data between terminal devices and the core network.
  • Core network responsible for maintaining the contract data of the mobile network, managing the network elements of the mobile network, and providing session management, mobility management, policy management, security authentication and other functions for terminal devices.
  • network access authentication is provided for the terminal device; when the terminal device has a service request, network resources are allocated to the terminal device; when the terminal device moves, network resources are updated for the terminal device; when the terminal device is idle, Provide a quick recovery mechanism for the terminal device; release network resources for the terminal device when the terminal device is detached; when the terminal device has business data, provide data routing functions for the terminal device, such as forwarding uplink data to the data network; or from data
  • the network receives downlink data from the terminal device and forwards it to the RAN, which then sends it to the terminal device.
  • Data network A data network that provides business services to users.
  • the client is located in the terminal device and the server is located in the data network.
  • the data network can be a private network, such as a local area network, or an external network that is not controlled by the operator, such as the Internet. It can also be a proprietary network deployed by operators, such as an IP multimedia network subsystem. core network subsystem, IMS) service network.
  • IMS IP multimedia network subsystem
  • the core network user plane includes user plane function (UPF); the core network control plane includes access and mobility management function (AMF), session management function (SMF) , unified data management (UDM), policy control function (PCF), application function (AF), authentication server function (AUSF), network slice selection function (network slice selection function (NSSF), network slice-specific authentication and authorization function (NSSAAF), network slice admission control function (NSACF).
  • UPF user plane function
  • AMF access and mobility management function
  • SMF session management function
  • UDM unified data management
  • PCF policy control function
  • AF authentication server function
  • AUSF authentication server function
  • NSSF network slice selection function
  • NSSAAF network slice-specific authentication and authorization function
  • NSACF network slice admission control function
  • the core network control plane adopts a service-oriented architecture, and the interaction between control plane network elements adopts service invocation to replace the point-to-point communication method in the traditional architecture.
  • control plane network elements will open services to other control plane network elements for calls by other control plane network elements; in point-to-point communication, the communication interfaces between control plane network elements will store a specific set of messages, only It can be used by the control plane network elements at both ends of the interface during communication.
  • Session management network element Mainly used for session management, IP address allocation and management of terminal equipment, selecting endpoints that can manage user equipment plane functions, policy control, or charging function interfaces, and downlink data notifications.
  • the session management network element can be an SMF network element.
  • the session management function network element can still be an SMF network element, or have other names. This application does not limit this.
  • Nsmf is a service-based interface provided by SMF. SMF can communicate with other network functions through Nsmf.
  • Access management network element It is mainly used for mobility management and access management.
  • it can be the mobility management entity (MME) function in the 4G communication network or the AMF network element in the 5G network.
  • MME mobility management entity
  • the access management network element can still be an AMF network element, or have other names, which is not limited in this application.
  • Namf is a service-based interface provided by AMF. AMF can communicate with other network functions through Namf.
  • Policy control network element A unified policy framework used to guide network behavior and provide policy rule information for control plane functional network elements (such as AMF, SMF, etc.).
  • the policy control network element can be the PCF network element.
  • future communications such as 6G communications, the policy control network element can still be a PCF network element, or have other names. This application does not limit this.
  • Npcf is a service-based interface provided by PCF. PCF can communicate with other network functions through Npcf.
  • Data management network element used to process user identification, subscription, access authentication, registration, or mobility management, etc.
  • the data management network element can be a UDM network element.
  • future communications such as 6G communication, the data management network element can still be a UDM network element, or have other names. This application does not limit this.
  • Nudm is a service-based interface provided by UDM. UDM can communicate with other network functions through Nudm.
  • Application network element used for data routing affected by applications, access to network open functions, or interaction with the policy framework for policy control, etc.
  • the application network element can be an AF network element.
  • future communications such as 6G communication, the application network element can still be an AF network element, or have other names. This application does not limit this.
  • Naf is a service-based interface provided by AF. AF can communicate with other network functions through Naf.
  • User plane network element used for packet routing and forwarding, or quality of service (QoS) processing of user plane data.
  • QoS quality of service
  • user plane network elements can be user plane function (UPF) network elements.
  • UPF user plane function
  • user plane network elements can still be UPF network elements, or have other names. This application There is no limit to this.
  • Authentication service network element mainly used for user authentication, etc.
  • the authentication service network element can be an AUSF network element.
  • future communications such as 6G communication, the authentication service network element can still be an AUSF network element, or have other names. This application does not limit this.
  • Nausf is a service-based interface provided by AUSF.
  • AUSF can communicate with other network functions through Nausf.
  • Network slicing selection function network element used to select network slices for terminal devices.
  • network slicing selection function network elements can be NSSF network elements.
  • future communications such as 6G communications, network slicing selection function network elements will still be used. It may be an NSSF network element or have other names, which is not limited in this application.
  • Authentication and authorization function network elements selected by network slicing used to perform slice authentication for terminal devices.
  • Figure 1 is only an example, and the core network may also include more or fewer network elements, which is not limited in this application.
  • UPF can include general UPF, PSA, local PSA, branch points (for example, uplink classifier user plane function (UL CL) and branch point (BP), etc.), as shown in Table 1 below for PSA, Local PSA, distribution points are explained.
  • branch points for example, uplink classifier user plane function (UL CL) and branch point (BP), etc.
  • the interface between AN and UPF may be an N3 interface, for example, the interface between RAN and ULCL in Figure 2.
  • the interface between any two UPFs can be an N9 interface, for example, the interface between the UL CL and the local PSA in Figure 2, and the interface between the UL CL and the PSA.
  • the interface between the PSA and the DN may be an N6 interface, for example, the interface between the PSA and the Internet and the interface between the local PSA and the local DN in Figure 2. It can be understood that the above interface names are only examples, and other interface names may be used as the network evolves, which is not limited in this application.
  • FIG. 2 shows a schematic diagram of the network architecture of the uplink classifier user plane function (UL CL).
  • UE1 wishes to access non-EC services (eg, Internet).
  • UE1 sends uplink data to UL CL through AN, and UL CL shunts the uplink data to PSA based on the characteristics of the uplink data, and then the PSA further forwards the uplink data to the Internet.
  • PSA receives downlink data from the Internet and forwards the downlink data to UL CL, and UL CL forwards the downlink data to UE1 through AN.
  • UE2 wishes to access EC services (for example, local DN).
  • UE2 sends uplink data to UL CL through AN, and UL CL offloads the uplink data to the local PSA based on the characteristics of the uplink data, and further forwards the uplink data to the local DN from the local PSA.
  • the local PSA receives the downlink data from the local DN and forwards the downlink data to the UL CL UPF, and the UL CL forwards the downlink data to UE2 through the AN.
  • user plane devices basically follow a tree topology deployment.
  • Uplink user packets pass through the base station and backhaul network, and finally access the data network through the centrally deployed anchor gateway.
  • these anchor gateways are generally deployed at higher locations in the network, such as regional central computer rooms.
  • the above deployment method is relatively simple and facilitates operators to conduct centralized business management and control and packet processing at the anchor gateway.
  • EC edge computing
  • some services may be served by multiple EAS deployed at the edge of the network. These EAS provide the same services and content, but have different IP addresses.
  • the EC scenario requires it to access an available EAS that is close to the terminal device. Therefore, the end device needs to obtain the appropriate EAS IP address.
  • the 3rd generation partnership project (3GPP) standard TS 23.548 defines a new network element that assists EAS discovery, namely the edge application server discovery function (EASDF). Its main function is to detect The instructions of the management network element process domain name server (DNS) messages.
  • EASDF edge application server discovery function
  • DNS domain name server
  • the DNS query message includes the identification of the service that the terminal device requests to access, such as a fully qualified domain name (FQDN).
  • FQDN fully qualified domain name
  • EASDF sends the identification of the service that the terminal device requests to access to the session management network element, and obtains the DNS extended mechanisms for DNS-client-subnet option (ECS option) from the session management network element.
  • ECS option is a DNS message extension defined by the Internet Engineering Task Force (IETF). It is used to represent the location of the terminal device and assist the DNS server in resolving the local EAS IP address of the terminal device.
  • EASDF can add the ECS option in the DNS query message, forward the DNS query with the ECS option added to the DNS server, and forward the DNS response (response) message from the DNS server to the terminal device.
  • the DNS response message includes the EAS IP address.
  • EASDF sends the identification of the service that the terminal device requests to access to the session management network element, and obtains the local DNS (local DNS) address from the session management network element.
  • the local DNS address is a DNS server deployed locally on the terminal device. Therefore, even if the DNS query message does not contain information indicating the location of the terminal device, the local DNS server that receives the DNS query message will parse the local EAS of the terminal device based on its own location. IP address. Further, EASDF forwards the DNS query to the DNS server corresponding to the local DNS address, and forwards the DNS response message from the DNS server to the terminal device.
  • the DNS response message includes the EAS IP address.
  • PLMN a certain standard of cellular mobile communication network of a certain operator
  • the PLMN signed by the terminal equipment is called the home PLMN (HPLMN), which represents the network deployed by the subscriber's home operator.
  • HPLMN home PLMN
  • the home PLMN can also be called the home PLMN, which is the preferred PLMN for terminal equipment to access.
  • the visited PLMN can be understood as a PLMN other than the home PLMN, which can also be called a non-home PLMN, or a PLMN other than the home PLMN that deploys EC services, and the EC services do not support User plane network element access of the home PLMN, or a PLMN other than the home PLMN that can access the EC service, and the EC service does not support user plane network element access of the home PLMN.
  • the home PLMN may also be called the first PLMN
  • the visited PLMN may also be called the second PLMN.
  • the visited network element can understand network elements deployed in PLMNs other than the home PLMN.
  • the visited network elements may include visited session management network elements, visited user plane network elements (for example, visited anchor point user plane network elements), etc.
  • the home session management network element refers to the session management network element deployed in the first PLMN
  • the visited session management network element refers to the second PLMN.
  • the session management network element deployed in the first PLMN; the home user plane network element refers to the user plane network element deployed in the first PLMN, and the visited user plane network element refers to the user plane network element deployed in the second PLMN.
  • the visited anchor user plane network element refers to the anchor user plane network element deployed in the second PLMN.
  • Figure 3 shows a network architecture including UL CL, and some network elements have been omitted.
  • the home session management network element (SMF in HPLMN in Figure 2) determines the visiting session management network element (VPLMN in Figure 2 SMF), and obtains the information of the visited anchor user plane network element (L-PSA in Figure 2) through the visited session management network element. Belonging place
  • the call management network element selects the home distribution point (UL CL in Figure 2) and the visited anchor point user plane network element to create a session for the terminal device, which is used to enable the terminal device to access the first user plane network element through the visited anchor point user plane network element. business.
  • the visited anchor point user plane network element supports an edge application server (EAS) that accesses the first service (EAS in Figure 2) or an EHE that deploys the first service.
  • EAS edge application server
  • EHE EHE
  • Figure 4 shows a network architecture that does not include UL CL, and some network elements have been omitted.
  • the home session management network element (SMF in HPLMN in Figure 4) determines the visiting session management network element (SMF in VPLMN in Figure 4), And obtain the information of the visited anchor point user plane network element (L-PSA in Figure 4) through the visited session management network element.
  • the home session management network element selects the home user plane network element (UPF in HPLMN in Figure 4) and the visited anchor point user plane network element (L-PSA in Figure 4) to create a session for the terminal device.
  • the terminal device is enabled to access the first service through the visited anchor point user plane network element.
  • the visited anchor point user plane network element supports EAS for accessing the first service (EAS in Figure 3) or EHE for deploying the first service.
  • EAS accessing the first service
  • FIGS. 10 to 12 For the above specific process, reference can also be made to the embodiment shown in FIGS. 10 to 12 .
  • the public land mobile network at the first visited place does not support (or allow) the home user plane network element to access the first service; or, it can also be understood that the public land mobile network at the first visited place does not support other than the first visited service.
  • User plane network elements in other PLMNs other than the public land mobile network in the first visited place are allowed to access the first service; or, it can also be understood that only some user plane network elements in the public land mobile network in the first visited place are allowed to access the first service. service; alternatively, it can also be understood that the EHE of the first visited public land mobile network only allows access to the anchor user plane network element (for example, PSA) of the first visited public land mobile network.
  • PSA anchor user plane network element
  • the EHE of the home public land mobile network does not deploy the first service, or the home public land mobile network does not deploy the EHE.
  • terminal equipment 1 accesses service X
  • operator B's MEC platform does not support operator A's UPF access
  • the terminal equipment accesses service That is to say, the terminal device may not be able to access service X, or the terminal device may not be able to access a platform that deploys service
  • the EAS that deploys service X is nearby, but can only access the platform that deploys service
  • terminal device 2 accesses service .
  • this application provides a communication method to solve the problem that the MEC platform deploying a certain service does not support PSA access of other operators, which may lead to high latency and/or poor reliability of terminal equipment accessing the service.
  • the problem is not limited to, but not limited to, but not limited to, but not limited to, but not limited to, but not to, but not to, but not to, but not to, but not to, but not to, but not to, but not to terminal equipment accessing the service.
  • the method includes:
  • Step 600 The terminal device sends a session establishment request message to the home session management network element.
  • the session establishment request message is used to request the establishment of a session of the terminal device.
  • the terminal device may send a session establishment request message to the home session management network element through the home access and mobility management network element.
  • Step 610 The home session management network element determines the visiting session management network element.
  • the following describes how the home session management network element determines the visited session management network element based on the first possible implementation method, the second possible implementation method, and the third possible implementation method:
  • the home session management network element determines the first visited public land mobile network based on the location of the terminal device. Further, the home session management network element obtains the information of the visited session management network element according to the identifier of the first visited public land mobile network, and the visited session management network element is deployed in the first visited public land mobile network.
  • the home session management network element may determine the visited public land mobile network corresponding to the location of the terminal device based on the location of the terminal device, and use the visited public land mobile network corresponding to the location of the terminal device as the first visited location.
  • Public land mobile network may be determined the visited public land mobile network corresponding to the location of the terminal device based on the location of the terminal device, and use the visited public land mobile network corresponding to the location of the terminal device as the first visited location.
  • the visited public land mobile network corresponding to the location of the terminal device may refer to the visited public land mobile network with coverage (or deployment) at the location of the terminal device.
  • the number of visited public land mobile networks corresponding to the location of the terminal device may be N, and N is a positive integer.
  • the number of first visited public land mobile networks may be M, M is a positive integer, and M ⁇ N. That is to say, the home session management network element can determine one or more visited public land mobile networks based on the location of the terminal device.
  • this embodiment is described with the first visited public land mobile network and the first visited session management network element being one. It should be understood that when there are multiple first visited public land mobile networks and first visited session management network elements, the relevant actions can be performed in each first visited session management network element, or in This can be performed between the home session management network element and each first visited session management network element.
  • PLMN 1 and PLMN 2 are deployed at the location of the UE.
  • the UE belongs to PLMN 1
  • PLMN 1 is the home public land mobile network
  • PLMN 2 is the visiting public land mobile network.
  • the home session management network element determines PLMN 2 based on the location of the UE, and obtains the information of the visited session management network element based on the identification of PLMN 2.
  • the visited session management network element is deployed in PLMN 2.
  • PLMN 1, PLMN 2 and PLMN 3 are deployed at the location of the UE.
  • the UE belongs to PLMN 1
  • PLMN 1 is the home public land mobile network
  • PLMN 2 and PLMN 3 are the visiting public land mobile networks.
  • the home session management network element determines PLMN 2 and PLMN 3 based on the location of the UE, and obtains the information of the visited session management network element 1 based on the identity of PLMN 2.
  • the visited session management network element 1 is deployed in PLMN 2, and based on PLMN 3
  • the identifier obtains the information of the visited session management network element 2, and the visited session management network element 2 is deployed in PLMN 3.
  • the home session management network element can also determine the visited public land mobile network from the above determined visited public land mobile network.
  • the network is screened out for visiting public land mobile networks that have a cooperative relationship with the home public land mobile network, such as visiting public land mobile networks that have signed a Service Level Agreement (Service Level Agreement, SLA) with the home public land mobile network.
  • SLA Service Level Agreement
  • the home session management network element may use the selected visited public land mobile network as the first visited public land mobile network.
  • the home session management network element can obtain the corresponding relationship between the first service and the first visited public land mobile network.
  • the home session management network element may also determine the first visited public land mobile network based on the location of the terminal device and the corresponding relationship between the first service and the first visited public land mobile network. Further, The home session management network element can obtain the information of the visited session management network element according to the identifier of the first visited public land mobile network, and the visited session management network element is deployed in the first visited public land mobile network.
  • the home session management network element may locally configure or receive the corresponding relationship between the first service and the first visited public land mobile network from the application function network element.
  • This application does not limit the home session management network element to obtain the corresponding relationship. specific way.
  • the corresponding relationship between the first service and the first visited public land mobile network may be included in the EAS deployment information (EAS deployment information, EDI). That is to say, the EDI includes the corresponding relationship between the first service and the first visited public land mobile network.
  • the EDI includes the FQDN of the first service and the identification of the first visited public land mobile network.
  • the EDI includes the corresponding relationship between the FQDN of service X (an example of the first service) and PLMN2 (an example of the first visited public land mobile network), where service Access business. This application does not limit the specific form of the above corresponding relationship.
  • EDI can also include DN name (data network name DNN), single network slice selection assistance information (S-NSSAI), DNS server information, EAS IP range, and/or EDI group identifier, etc. .
  • DN name data network name DNN
  • S-NSSAI single network slice selection assistance information
  • DNS server information EAS IP range
  • EAS IP range EAS IP range
  • EDI group identifier etc.
  • the above corresponding relationship or the EDI including the corresponding relationship may be valid for multiple or all terminal devices, and is not limited to the session or terminal device involved in step 600.
  • obtaining and storing the corresponding relationship or the EDI granularity including the corresponding relationship is not limited to the session or terminal device involved in step 600.
  • the home session management network element selects the visited session management network element for the session, and selects the visited session management network element from the visited session.
  • the local session management network element obtains the information of the user plane network element of the visited anchor point, and then establishes a path for the terminal device to access the first service in advance.
  • the terminal device can access the first service through the previously established path to access the first service.
  • the terminal device may not initiate access to the first service until the session is released.
  • the home session management network element can also obtain first indication information, which is used to indicate that the first service is accessed through the anchor user plane network element of the first visited public land mobile network.
  • first indication information which is used to indicate that the first service is accessed through the anchor user plane network element of the first visited public land mobile network.
  • the home session management network element may receive EDI, where the EDI includes the correspondence between the first service and the first visited public land mobile network, and the first indication information.
  • the home session management network element can determine the first visited public land mobile network based on the corresponding relationship and the location of the terminal device, the home session management network element can first determine the location of the terminal device based on the location of the terminal device. The visited public land mobile network corresponding to the location, and then determine the first visited public land mobile network based on the corresponding relationship between the first service and the first visited public land mobile network and the visited public land mobile network corresponding to the location of the terminal device. For example, when the visited public land mobile network corresponding to the location of the terminal device includes a first visited public land mobile network, the home session management network element selects the first visited public land mobile network.
  • PLMN 1, PLMN 2 and PLMN 3 are deployed at the location of the UE.
  • the UE belongs to PLMN 1
  • PLMN 1 is the home public land mobile network
  • PLMN 2 and PLMN 3 are the visiting public land mobile networks.
  • PLMN 2 has deployed service X that only supports PSA access of PLMN 2, but PLMN 1 has not deployed service X.
  • the home session management network element obtains the corresponding relationship between the service Deployed on PLMN 2.
  • the home session management network element can also The first visited public land mobile network is determined based on the public land mobile network of the visited place that has a cooperative relationship with the public land mobile network of the home place, which will not be described again here.
  • the corresponding relationship between the first service and the first visited public land mobile network can be replaced by the first The corresponding relationship between the service and the visited user plane network element (including the corresponding relationship between the first service and the visited user plane network element and the first visited public land mobile network).
  • the home session management network element can be based on the terminal equipment.
  • the location and the corresponding relationship between the first service and the visited user plane network element determine the visited user plane network element.
  • the home session management network element can obtain the information of the visited session management network element based on the information of the visited user plane network element.
  • the visited user plane network element and the visited session management network element are deployed in the same visited public land mobile network. network.
  • the corresponding relationship between the first service and the visited user plane network element can be understood as the first visited public land mobile network supports the visited user plane network element to access the first service. It can also be understood that the first visited public land mobile network supports the home public land mobile network to access the first service through the visited user plane network element, or the first visited public land mobile network supports other than the first visited public land mobile network. Other public land mobile networks other than the mobile network access the first service through the visited user plane network element.
  • the corresponding relationship between the first service and the first visited public land mobile network may be included in EDI or other information, and the corresponding relationship between the first service and the first visited public land mobile network may be stored locally in the home session management network element.
  • the home session management network element can obtain the information of the visited session management network element in but not limited to the following methods:
  • the home session management network element can obtain the information of the visiting session management network element from the network storage function network element.
  • the information about the visited session management network element may include the identity and/or address of the visited session management network element.
  • the home session management network element may send a request message to the network storage function network element, where the request message includes the identification of the first visited public land mobile network and/or the information of the visited user plane network element.
  • the network storage function network element After the network storage function network element receives the request message, the network storage function network element sends a response message to the home session management network element, where the response message includes information about the visiting session management network element.
  • the identifier of the first visited public land mobile network is used to determine the visited session management network element.
  • the information of the visited user plane network element is used to determine the visited session management network element.
  • the information of the visited user plane network element can assist the network storage function network element in selecting and managing or controlling the visited session of the visited user plane network element.
  • Manage network elements thereby enabling the visited user plane network element to select the visited anchor user plane network element that supports access to the first service.
  • the request message may also include other content, such as location information of the terminal device, DNN, S-NSSAI, etc., which is not limited in this application.
  • the above-mentioned network storage function network element can be a visiting network storage function network element or a home network storage function network element, which is not limited in this application.
  • the home session management network element can obtain the information of the visited session management network element through the home access and mobility management network elements.
  • the information about the visited session management network element may include the identity and/or address of the visited session management network element.
  • the home session management network element sends a first request message to the home access and mobility management network element.
  • the first request message includes the identification of the first visited public land mobile network and/or the visited user plane network. Yuan information. That , for details about the relevant content of the first request message, please refer to the relevant description in the above method 1.
  • the home access and mobility management network element may obtain and feed back the visited session management network in the following manner, but is not limited to Yuan information.
  • the home access and mobility management network element can locally configure the corresponding relationship between the identity of the public land mobile network and the information of the session management network element, and then the home access and mobility management network element can configure the corresponding relationship between the identity of the public land mobile network and the information of the session management network element according to the request message.
  • the identification of the first visited public land mobile network determines the corresponding visited session management network element.
  • the home access and mobility management network element locally configures the corresponding relationship between the address of the user plane network element and the information of the session management network element, and then the home access and mobility management network element can configure the corresponding relationship between the address of the user plane network element and the information of the session management network element according to the request message.
  • the information of the visited user plane network element determines the corresponding visited session management network element.
  • the home access and mobility management network element sends a response message to the first request message to the home session management network element, where the response message to the first request message includes information about the visited session management network element.
  • Method B The home access and mobility management network element sends a second request message to the network storage function network element.
  • the second request message may include the content included in the first request message.
  • the network storage function network element sends a response message to the second request message to the home access and mobility management network element.
  • the response message to the second request message includes information about the visited session management network element.
  • the home access and mobility management network element sends a response message to the first request message to the home session management network element, where the response message to the first request message includes information about the visited session management network element.
  • the home session management network element can locally configure the corresponding relationship between the identity of the public land mobile network and the information of the session management network element, and then the home session management network element can determine the corresponding relationship based on the identity of the first visited public land mobile network.
  • the visited session management network element can locally configure the corresponding relationship between the address of the user plane network element and the information of the session management network element, and then the home session management network element can use the information of the visited user plane network element in the request message. Determine the corresponding visited session management network element.
  • Step 620 The home session management network element obtains the information of the visited anchor point user plane network element from the visited session management network element.
  • the home session management network element sends a session establishment request message to the visited session management network element, and the visited session management network element selects the visited anchor user plane network element. Specifically, the visited session management network element does not select Visit the diversion point.
  • the visited session management network element sends a session establishment response message to the home session management network element.
  • the session establishment response message includes information about the visited anchor point user plane network element.
  • the home session management network element can also send one or more of the following contents to the visited session management network element.
  • the following are all used to assist the visited session management network element in selecting the visited anchor user plane network element, as follows:
  • the content may be carried by the session establishment request message or sent separately, which is not limited in this application.
  • the home session management network element may also send second indication information to the visiting session management network element.
  • the second instruction information instructs the visited session management network element to select the visited anchor point user plane network element and not to select the visited distribution point.
  • the home session management network element may also send an identifier of the first service to the visited session management network element.
  • the identifier of the first service is used to select a visited anchor point that supports access to the first service.
  • User plane network elements may also send an identifier of the first service to the visited session management network element.
  • the home session management network element can also send the location information of the terminal device to the visited session management network element.
  • the location information of the terminal device is used to select the visited anchor user plane network element.
  • the location information of the terminal device may be at least one of tracking area information, a cell identifier, a data network access identifier, and the like.
  • the location of the same terminal device The definition of configuration information may be different.
  • the area information tracked by the terminal equipment in PLMN A is different from the area information tracked by the terminal equipment in PLMN B. That is to say, the session management network element in PLMN B cannot understand the area information in PLMN A.
  • the terminal equipment tracking area information in PLMN A is sent by the session management network element.
  • embodiments of this application provide the following solutions to enable the visited session management network element to understand the location information of the terminal device sent by the home session management network element.
  • Solution 1 The home session management network element sends the location information of the terminal device in the home public land mobile network to the visited session management network element.
  • the visited session management network element obtains the mapping relationship, and the visited session management network element can determine the location information of the terminal device in the home public land mobile network.
  • the location information of the device in the home public land mobile network and the mapping relationship determine the location information of the terminal device in the first visited public land mobile network.
  • the location information of the terminal device includes at least one of tracking area information in the home public land mobile network, or cell identification, or data network access identification.
  • the mapping relationship indicates a mapping relationship between location information in the home public land mobile network and location information in the first visited public land mobile network.
  • the mapping relationship may be locally configured by the visited session management network element or sent by the application function network element. This application does not limit the specific way in which the visited session management network element obtains the mapping relationship.
  • the visited session management network element obtains the mapping relationship between the TAI of the home public land mobile network and the DNAI of the first visited public land mobile network.
  • the visited session management network element can configure the home public land mobile network according to the terminal equipment.
  • the TAI and the mapping relationship can determine the public land mobile network DNAI of the terminal device in the first visited place.
  • the home session management network element obtains the mapping relationship.
  • the home session management network element determines where the terminal device is in the first visited public land mobile network based on the location information of the terminal device in the home public land mobile network and the mapping relationship. location information in.
  • the home session management network element sends the location information of the terminal device in the first visited public land mobile network to the visited session management network element.
  • the location information of the terminal device includes at least one of tracking area information in the public land mobile network of the first visited place, or cell identification, or data network access identification.
  • tracking area information in the public land mobile network of the first visited place or cell identification, or data network access identification.
  • the home session management network element obtains the mapping relationship between the TAI of the home public land mobile network and the DNAI of the first visited public land mobile network.
  • the home session management network element can configure the home public land mobile network in the home public land mobile network based on the terminal device.
  • the TAI and the mapping relationship can determine the public land mobile network DNAI of the terminal device in the first visited place.
  • the home session management network element sends the DNAI of the terminal equipment in the first visited public land mobile network to the visited session management network element.
  • the location information of the terminal device is the geographical location information of the terminal device. For example, the latitude and longitude information of the terminal device.
  • the home session management network element converts the location information of the terminal device in the home public land mobile network into the geographical location information of the terminal device, and sends the geographical location information of the terminal device to the visited session management network element .
  • the visited session management network element converts the received geographical location information of the terminal device into the location information of the terminal device in the first visited public land mobile network.
  • the home session management network element selects the home offloading point (for example, UL CL in Figure 3), the home anchor point user plane network element (for example, HPLMN in Figure 3) (PSA in Figure 3) and home edge application server discovery network elements (such as EASDF in HPLMN in Figure 3), etc. Further, after obtaining the information of the user plane network element of the visited anchor point, the home session management network element sends an offload to the home offload point. Rules, the offloading rule instructs to offload packets in the address range corresponding to the public land mobile network in the first visited place to the visited anchor point user plane network element.
  • the offloading rule instructs the packets in the address range corresponding to the location of the terminal device to be offloaded.
  • the traffic is diverted to the user plane network element of the visited anchor point.
  • the address range corresponding to the public land mobile network of the first visited place refers to the IP address range of the services deployed by the public land mobile network of the first visited place, for example, the IP address of the EAS or EHE deployed by the public land mobile network of the first visited place.
  • the packets in the address range corresponding to the public land mobile network of the first visited place refer to the packets whose destination IP address falls within the address range corresponding to the public land mobile network in the first visited place.
  • the home distribution point receives the first message, and determines that the target IP address of the first message falls within the address range based on the address range corresponding to the public land mobile network of the first visited place and the target IP address of the first message, Then the home distribution point sends the first message to the visited anchor point user plane network element.
  • the offloading rule indicates that the packets in the address range of the first service are offloaded to the visited anchor point user plane network element.
  • the home session management network element may determine the address range of the first service based on EDI, or may determine it in other ways, which is not limited by this application.
  • the address range corresponding to the location of the terminal device refers to the IP address of the EAS or EHE deployed at the location of the terminal device.
  • the packets in the address range corresponding to the location of the terminal device refer to the packets whose destination IP address falls within the address range corresponding to the location of the terminal device.
  • the home session management network element can select or not select the home anchor user plane network element. If the home anchor user plane network element is not selected, the home offloading point can Directly connect to the visited edge application server to discover network elements.
  • the PSA in HPLMN in Figure 3 is an optional network element.
  • the H-UPF as UL CL in HPLMN can also be used as H-PSA at the same time and directly connect to H-EASDF.
  • the terminal device can send uplink data to the visited anchor user plane network element (such as the L-PSA in the VPLMN in Figure 3) through the home distribution point, and the visited anchor point
  • the user plane network element sends the received uplink data to the edge application server deploying the first service (such as EAS in the VPLMN in Figure 3).
  • the edge application server deploying the first service will need to send the downlink data to the terminal device.
  • the data is sent to the home distribution point through the visited anchor point user plane network element, and the home distribution point forwards the received downlink data to the terminal device.
  • the terminal device can access the service through the visited anchor point user plane network element, so it can improve
  • the reliability of the terminal device's access to the service deployed in the visiting place and the reduction of the delay in accessing the service solve the problem that the edge application server deploying the service (which can be called the first service) does not support the anchor point user plane network element access in the home place. access, resulting in high latency and/or poor reliability for terminal devices to access the service.
  • H-SMF corresponds to the home session management network element in the embodiment shown in Figure 6
  • V-SMF corresponds to the visited session management network element in the embodiment shown in Figure 6.
  • H-NRF corresponds to the network storage function network element in the embodiment shown in Figure 6.
  • V-AMF corresponds to the home access and mobility management network element in the embodiment shown in Figure 6.
  • H-UL CL is the home distribution point in the embodiment shown in Figure 6
  • H-PSA is the home anchor point user plane network element in the embodiment shown in Figure 6
  • H-EASDF corresponds to the home anchor point user plane network element in the embodiment shown in Figure 6
  • the home edge application server discovers network elements.
  • V-PSA is the visited anchor point user plane network element in the embodiment shown in Figure 8.
  • H-SMF obtains EDI, which contains the corresponding relationship between service X and PLMN1ID.
  • service X may be an example of the first service in Figure 6 above.
  • PLMN1 is the First visited public land mobile network.
  • S702 The UE sends a PDU session establishment request to H-SMF.
  • the PDU session establishment request may be a possible implementation manner of the above step 600.
  • step 610 The following S703 to S706A or S703 to S708B are two possible implementations of step 610.
  • H-SMF determines PLMN1.
  • the H-SMF determines which (one or more) PLMNs to select based on the PLMNs deployed at the UE's location and the PLMNs that have a cooperative relationship with the HPLMN.
  • the partnership may be a roaming agreement. The following only uses H-SMF to determine PLMN1 and determine to insert H-UL CL as an example.
  • the H-SMF can also determine PLMN1 based on the corresponding relationship between the service
  • the H-SMF obtains the information of the V-SMF, specifically including the above-mentioned S704A to S706A, or S704B to S708B.
  • H-SMF sends a network element discovery request (Nnrf_NFDiscovery_Request) message to H-NRF. This message is used to request V-SMF information.
  • Nnrf_NFDiscovery_Request a network element discovery request
  • This message may include the UE's location information, PLMN1ID.
  • the message can also include DNN, S-NSSAI.
  • the message may include the address of the V-UPF.
  • V-UPF is the UPF in PLMN1.
  • the network element discovery request message can be a possible implementation manner of the request message in the above-mentioned method 1 for the home session management network element to obtain the information of the visited session management network element.
  • H-NRF obtains V-SMF information.
  • V-SMF information includes V-SMFID and/or address.
  • V-SMF is the SMF in PLMN1.
  • H-NRF sends a network element discovery response (Nnrf_NFDiscovery_Response) message to H-SMF.
  • This message includes V-SMF information.
  • the network element discovery response message can be a possible implementation method of the response message in method 1 in which the home session management network element obtains the information of the visited session management network element.
  • H-SMF sends a PDU session context status notification request (Nsmf_PDUSession_SMContextStatusNotify Request) message to H-AMF.
  • This message includes PLMN1ID and may also include instruction information for selecting V-SMF.
  • the PDU session context status notification request message may be a possible implementation manner of the first request message in the method 2 for the home session management network element to obtain the information of the visited session management network element.
  • H-AMF sends a network element discovery request message to H-NRF. This message is used to request V-SMF information.
  • the message content is the same as S704A.
  • the network element discovery request message may be a possible implementation manner of the second request message in Method 2 in which the home session management network element obtains the information of the visited session management network element.
  • S706B H-NRF obtains V-SMF information.
  • H-NRF sends a network element discovery response message to H-AMF.
  • the message content is the same as S706A.
  • the network element discovery response message may be a possible implementation manner of the second response message in Method 2 in which the home session management network element obtains the information of the visited session management network element.
  • H-AMF sends a PDU session context status notification response (Nsmf_PDUSession_SMContextStatusNotify Response) message to H-SMF.
  • This message includes V-SMF information.
  • the PDU session context status notification response message may be a possible implementation manner of the first response message in Method 2 in which the home session management network element obtains the information of the visited session management network element.
  • H-SMF sends a PDU session establishment request (Nsmf_PDUSession_Create Request) message to V-SMF.
  • the PDU session establishment request message may be a possible implementation manner of the message sent by the home session management network element to the visited session management network element in step 820 in order to obtain information about the visited anchor point user plane network element.
  • the H-SMF can also send other information to the V-SMF.
  • the H-SMF can also send other information to the V-SMF. For details, please refer to step 620.
  • V-SMF selects V-PSA, but does not select V-UL CL/BP.
  • V-SMF sends a PDU session establishment response (Nsmf_PDUSession_Create Response) message to H-SMF, which includes V-PSA information.
  • V-PSA information includes the identification and/or address of the V-PSA.
  • the PDU session establishment request message may be a possible implementation manner for the visited session management network element to send information about the visited anchor point user plane network element to the home session management network element in step 820.
  • H-SMF selects H-UL CL, H-PSA, H-EASDF, and sends offloading rules to H-UL CL.
  • This offloading rule instructs packets in the IP address range corresponding to PLMN1 to be offloaded to V-PSA.
  • H-UL CL determines that the target IP address of the received message falls into the IP address range corresponding to PLMN1, and H-UL CL forwards the message to V-PSA.
  • the IP address range corresponding to PLMN1 can be the IP address range of the MEC platform where service X is deployed, or the IP address range of the EAS of service X.
  • H-SMF sends a PDU session establishment accept message to the UE.
  • the message includes the address of H-EASDF.
  • V-SMF and V-PSA can be selected when the UE establishes a session, and then the UE can access service X through V-PSA, which can improve the reliability of the UE's access to service X and reduce the delay of accessing service X.
  • this application provides a communication method to solve the problem that the MEC platform deploying a certain service does not support PSA access of other operators, which may lead to higher latency and/or lower reliability of terminal equipment accessing the service. Bad question.
  • the method includes:
  • Step 800 The home session management network element receives the identification of the first service requested by the terminal device to access.
  • the terminal device sends a domain name system query (DNS Query) message to the home edge application server discovery network element.
  • DNS Query domain name system query
  • the message includes the identifier of the first service, for example, the FQDN of the first service.
  • the home edge application server discovers the network element and sends the identifier of the first service to the home session management network element.
  • the terminal device accesses the first service.
  • Step 810 The home session management network element determines the visited session management network element according to the identification of the first service and the correspondence between the first service and the first visited public land mobile network.
  • the visited session management network element is deployed in the first visited public land mobile network.
  • the first visited public land mobile network does not support the home user plane network element to access the first service.
  • the home session management network element determines the first visited public land mobile network based on the identification of the first service and the corresponding relationship between the first service and the first visited public land mobile network.
  • the visited public land mobile network is the visited public land mobile network corresponding to the location of the terminal device. Further, the home session management network element may obtain the visited session management network based on the identification of the first visited public land mobile network.
  • the visited destination session management network element is deployed in the first visited destination public land mobile network.
  • the home session management network element can also obtain the first indication information, and reference can be made to the relevant description in the second possible implementation manner in step 610.
  • the home session management network element queries whether to store a corresponding relationship between a service and the first visited public land mobile network according to the identifier of the first service. If saved, the home session management network element determines the first visited public land mobile network. At the same time, the home session management network element can also determine the visited public land mobile network corresponding to the location of the terminal device based on the location of the terminal device, and determine the first visited public land mobile network as the visited location corresponding to the location of the terminal device. One of the public land mobile networks.
  • the home session management network element may also combine with the visited public land mobile network that has a cooperative relationship with the home public land mobile network to determine the first visited public land mobile network as the first visited public land mobile network that has a cooperative relationship with the home public land mobile network. Visited public land mobile network.
  • the home session management network element may determine the visited user plane network element according to the identity of the first service and the correspondence between the first service and the visited user plane network element. Further, the home session management network element can obtain the information of the visited session management network element based on the information of the visited user plane network element. The visited user plane network element and the visited session management network element are deployed in the same visited public land mobile network. network.
  • the home session management network element queries whether to store a corresponding relationship between a service and the visited user plane network element according to the identifier of the first service. If saved, the home session management network element determines the visited user plane network element.
  • the home session management network element can obtain the information of the visited session management network element by referring to the methods 1 to 1 of the home session management network element obtaining the information of the visited session management network element in step 610.
  • Way 3 the home session management network element can obtain the information of the visited session management network element by referring to the methods 1 to 1 of the home session management network element obtaining the information of the visited session management network element in step 610.
  • Step 820 The home session management network element obtains the information of the visited anchor point user plane network element from the visited session management network element.
  • step 820 can be applied to two different possible implementation scenarios, that is, the embodiment shown in Figure 8 can be applied to two different possible implementation scenarios.
  • Scenario 1 The home session management network element selects the home distribution point to enable the terminal device to access the first service through the visited anchor point user plane network element.
  • step 820 may refer to the relevant description in step 620 above, and repeated details will not be repeated. For details, please refer to the network architecture shown in Figure 3.
  • the home session management network element can also obtain the address of the edge application server.
  • the home session management network element can also send the address of the edge application server to the visited session management network element.
  • the address of the edge application server is used to select the visited anchor user plane network element.
  • the home session management network element inserts the home distribution point according to the address of the edge application server.
  • the distribution rule indicates that the address of the edge application server should be reported.
  • the traffic is diverted to the user plane network element of the visited anchor point.
  • the address of the edge application server may be the IP address of the edge application server, and the packet with the address of the edge application server is a packet whose destination IP address falls into the address of the edge application server.
  • Scenario 2 The home session management network element instructs the terminal device to create the first session. Among them, the first session is a new session. At this time, the operations before step 820 are all performed in the second session, and step 820 is to establish the first session.
  • the home session management network element does not directly select the home offloading point for the second session.
  • the second session is a session previously established by the terminal device with the home session management network element, that is, the second session is an old session, and the second session has not been released.
  • the first session is a session established between the terminal device and the home session management network element and the visited session management network element.
  • the second session is also a session established between the terminal device and the home session management network element and the visited session management network element. .
  • the home session management network element can determine the information of the visited session management network element according to the context of the second session.
  • the second session may be released after the first session is established, or may be released when the preset duration is reached, which is not limited in this application.
  • the terminal device can also access services deployed in the home public land mobile network according to the first session.
  • Scenario 1 may include three sub-scenarios:
  • Sub-scenario 1 The home session management network element notifies the home access and mobility management network elements of the visited session management network element, which is used to enable the home access and mobility management network elements to establish a new session (i.e. the first The home session management network element and the visited session management network element are selected during a session), that is, the home session management network element and the selected visited session management network element in the second session are reused.
  • the home session management network element determines the visited session management network element, and before obtaining the information about the visited anchor point user plane network element from the visited session management network element, the home session management network element sends a request to the home session management network element.
  • the access and mobility management network element sends the information of the visited session management network element, and the information of the visited session management network element is used to establish the first session.
  • Sub-scenario 2 The home session management network element does not notify the home access and mobility management network elements of the information about the visited session management network elements.
  • the home access and mobility management network elements know the information of the visited session management network elements.
  • the information or home access and mobility management network element stores information about the visited session management network element. For example, in the above-mentioned steps 610 and 810, the home session management network element obtains the content of method 2 in the information of the visited session management network element.
  • the home access and mobility management network element obtains the information of the visited session management network element and can store the information of the visited session management network element.
  • the home access and mobility management network element may select the home session management network element and the visited session management network element when establishing a new session (ie, the first session).
  • Sub-scenario 3 The home session management network element does not notify the home access and mobility management network elements of the visited session management network element, and the home access and mobility management network elements do not know the information of the visited session management network element. Information, the home session management network element selects the visited session management network element in the old session when determining the established new session.
  • the home session management network element determines the visited session management network element, and before obtaining the information about the visited anchor point user plane network element from the visited session management network element, the home session management network element sends a request to the home session management network element.
  • the access and mobility management network element sends a session modification instruction, and the session modification instruction is used to instruct the establishment of the first session.
  • the home session management network element receives a session management context message for creating the first session from the home access and mobility management network element.
  • the session management context message for creating the first session includes an identifier of the second session.
  • the session is a session previously established by the terminal device with the home session management network element, and the second session has not been released.
  • the home session management network element determines the information of the visited session management network element based on the identifier of the second session and the correspondence between the identifier of the second session and the information of the visited session management network element.
  • the corresponding relationship between the identifier of the second session and the identifier of the visited session management network element is stored in the context of the second session.
  • the visited session management network element and the visited anchor point user plane network element for the terminal device when it accesses the service deployed in the visited place (which can be called the first service), and then the terminal device can access the service through the visited place.
  • the ground anchor user plane network element accesses the service, which can improve the reliability of the terminal device accessing the service and reduce the delay of accessing the service. This solves the problem that the edge application server deploying the service does not support the home anchor user plane. Network element access leads to problems such as high latency and/or poor reliability for terminal devices to access the service.
  • H-SMF corresponds to the home session management network element in the embodiment shown in Figure 8
  • V-SMF corresponds to the visited session management network element in the embodiment shown in Figure 8.
  • H-NRF corresponds to the network storage function network element in the embodiment shown in Figure 8.
  • V-AMF corresponds to the home access and mobility management network element in the embodiment shown in Figure 8.
  • H-UL CL is the home distribution point in the embodiment shown in Figure 8
  • H-PSA is the home anchor point user plane network element in the embodiment shown in Figure 8
  • H-EASDF corresponds to the home anchor point user plane network element in the embodiment shown in Figure 8
  • the home edge application server discovers network elements.
  • V-PSA is the visited anchor point user plane network element in the embodiment shown in Figure 8.
  • H-SMF obtains the corresponding relationship between service X and PLMN1ID.
  • PLMN1 is not the PLMN accessed by the UE.
  • the corresponding relationship between service X and PLMN1ID can be included in the EDI.
  • the UE executes the PDU session establishment process. It is understandable that this is a non-roaming session establishment process.
  • S902 The UE sends a DNS Query message to H-EASDF.
  • the message includes the FQDN of service X.
  • H-EASDF sends FQDN to H-SMF.
  • step 800 the above-mentioned S902 and S903 can be used as a possible implementation manner of step 800.
  • H-EASDF matches the FQDN in the DNS Query with the DNS processing rules, and if the match is successful, the FQDN is reported to H-SMF.
  • S904 to S907A or S904 to S909B are two possible implementations of step 810.
  • H-SMF determines PLMN1.
  • H-SMF determines PLMN1 based on the correspondence between FQDN, service X and PLMN1ID.
  • PLMN1 is a PLMN deployed at the location of the UE, and a PLMN that has a cooperative relationship with the HPLMN.
  • S905A to S907A may refer to the above-mentioned S704A to S706A.
  • S905B to 809A can refer to the above-mentioned S704B to S708B.
  • H-SMF obtains the information of V-SMF, specifically including the above-mentioned S905A to S907A, or S905B to S909B.
  • H-SMF sends a request message to V-SMF.
  • the request message is used to request the ECS option or L-DNS address.
  • the request message may also include the authorization policy and/or the location information of the UE.
  • the authorization policy indicates that service access is allowed through V-PSA, or H-SMF is allowed to obtain the ECS option/L-DNS address corresponding to PLMN1.
  • the location information of the UE please refer to the relevant content of the location information of the terminal device in the embodiment shown in FIG. 6 .
  • V-SMF sends ECS option or L-DNS address to H-SMF.
  • H-SMF sends the ECS option or L-DNS address to H-EASDF.
  • H-EASDF sends a DNS Query message to DNS.
  • the DNS Query message includes ECS option.
  • H-SMF sends the L-DNS address to H-EASDF
  • H-EASDF sends a DNS Query message to L-DNS
  • the DNS at this time is L-DNS.
  • H-EASDF receives a DNS Response message from DNS.
  • the DNS Response message includes the EAS IP address.
  • H-EASDF sends the EAS IP address to H-SMF.
  • H-EASDF matches the EAS IP address in the DNS Response message with the DNS processing rules. If the match is successful, it caches the DNS Response message and reports the EAS IP address to H-SMF.
  • S910 to S915 are a possible implementation manner for the home session management network element to obtain the address of the edge application server.
  • H-SMF sends the EAS IP address and/or target DNAI to V-SMF.
  • the target DNAI is the DNAI determined by H-SMF based on the EAS IP address.
  • the DNAI can be the DNAI corresponding to HPLMN or PLMN1.
  • the EAS IP address and/or target DNAI can be carried through a PDU session establishment request message.
  • This application does not limit the messages carrying the above content.
  • H-SMF can also send other information to the V-SMF.
  • H-SMF may send indication information to V-SMF, and the indication information instructs V-SMF to select V-UPF and not select V-UL CL or BP.
  • V-SMF selects V-PSA, but does not select V-UL CL/BP.
  • V-SMF sends V-PSA information to H-SMF.
  • the V-PSA information includes the identification and/or address of the V-PSA.
  • V-PSA information may be carried by a PDU session establishment response message. This application does not limit the message carrying V-PSA information.
  • H-SMF selects H-UL CL, H-PSA, H-EASDF, and sends offloading rules to H-UL CL.
  • This offloading rule instructs packets in the IP address range corresponding to the target DNAI to be offloaded to V-PSA, or packets in the IP address range corresponding to the EAS IP address to be offloaded to V-PSA.
  • H-SMF sends a DNS context update request (NeasdfDNS Context_Update Request) message to H-EASDF.
  • This message is used to instruct H-EASDF to forward the DNS Response message to the UE.
  • H-EASDF sends a DNS context update response (NeasdfDNS Context_Update Response) message to H-SMF.
  • V-SMF and V-PSA for the UE when it accesses the service X, and then the UE can access the service X through the V-PSA, which can improve the reliability of the UE accessing the service delay.
  • the H-SMF corresponds to the home session management network element in the embodiment shown in Figure 8
  • the V-SMF corresponds to the visited session management network element in the embodiment shown in Figure 8.
  • V-AMF corresponds to the home access and mobility management network element in the embodiment shown in Figure 8.
  • H-PSA is the home anchor point user plane network element in the embodiment shown in Figure 8
  • H-EASDF corresponds to the home edge application server discovery network element in the embodiment shown in Figure 8.
  • V-PSA is the visited anchor point user plane network element in the embodiment shown in Figure 8.
  • S1001 to S1015 may refer to the above-mentioned S901 to S915, which are not shown here.
  • H-SMF sends the PDU session modification instruction and V-SMF information to H-AMF.
  • H-SMF can also send indication information to H-AMF to select the same SMF for the new session.
  • the above content may be carried by the N1N2 message transfer (Namf_Communication_N1N2MessageTransfer) message.
  • the H-SMF sends V-SMF information to the H-AMF, corresponding to the information of the home session management network element notifying the home access and mobility management network elements of the visited session management network element in sub-scenario 1.
  • H-AMF sends a PDU session modification command (PDU session modification command) to the UE.
  • H-AMF sends PDU session modification instructions to the UE through non-access stratum (NAS) messages.
  • NAS non-access stratum
  • the UE sends a PDU session establishment request message to the H-AMF.
  • the PDU session establishment request message contains the old session ID, that is, the ID of the session established before S902 in Figure 9.
  • the UE sends a PDU session establishment request message to the H-AMF, corresponding to the terminal device establishing a new session (ie, the first session) in sub-scenario 1.
  • the old session corresponds to the second session in the above sub-scenario 1.
  • the UE may also send indication information for selecting the same SMF to the H-AMF.
  • H-AMF determines to select H-SMF and V-SMF.
  • H-AMF determines to select H-SMF and V-SMF according to the old session ID and V-SMF information (from S1016).
  • the H-AMF determines to select the V-SMF based on the information of the V-SMF obtained from the H-SMF.
  • H-AMF can also determine to select H-SMF and V-SMF based on the indication information for selecting the same SMF, old session ID, and V-SMF information (from S1016).
  • H-AMF sends the old session ID to H-SMF.
  • the old session ID may be carried by the PDU Session Create Session Management Context (Nsmf_PDUSession_CreateSMContext) message.
  • H-SMF selects H-UPF.
  • H-SMF sends a PDU session establishment request message to V-SMF.
  • V-SMF selects V-PSA and configures N4 rules, selects V-EASDF and configures DNS processing rules.
  • V-SMF sends a PDU session establishment response message to H-SMF.
  • the message includes the address of V-PSA and the address of V-EASDF.
  • H-SMF and V-SMF establish tunnel information.
  • H-SMF and V-SMF can exchange information such as the UPF address to establish a user plane path. Specifically, H-SMF sends the address of H-UPF to V-SMF, V-SMF sends the address of H-UPF to V-PSA, and H-SMF sends the addresses of V-PSA and (R)AN to H-UPF. H-SMF sends the address of H-UPF to (R)AN.
  • H-SMF sends a PDU session establishment accept message to the UE, which includes the address information of V-EASDF.
  • Sub-scenario 2 in scenario 2 of the embodiment shown in Fig. 8 is described below with reference to Fig. 11: the correspondence between the network elements in Fig. 11 and the network elements in Fig. 8 can be referred to the above-mentioned Fig. 10, and will not be described again here.
  • S1101 to S1115 may refer to the above-mentioned S901 to S915, which are not shown here.
  • H-SMF sends a PDU session modification instruction to H-AMF.
  • H-SMF can also send indication information to H-AMF to select the same SMF for the new session.
  • the H-SMF does not send V-SMF information to the H-AMF, which corresponds to the home session management network element not notifying the home access and mobility management network elements of the visited session management network element in sub-scenario 2.
  • H-AMF sends a PDU session modification instruction to the UE.
  • the UE sends a PDU session establishment request to the H-AMF.
  • the PDU session establishment request contains the old session ID, that is, the ID of the session established before S902 in Figure 9.
  • the UE may also send indication information for selecting the same SMF to the H-AMF.
  • the UE sends a PDU session establishment request message to the H-AMF, corresponding to the terminal device establishing a new session (ie, the first session) in sub-scenario 2.
  • the old session corresponds to the second session in the above sub-scenario 2.
  • H-AMF determines to select H-SMF and V-SMF.
  • the H-AMF determines to select H-SMF and V-SMF according to the old session ID and V-SMF information (for example, from S707B).
  • the H-AMF executes S704B to S708B to save the information of the V-SMF, corresponding to the information of the home access and mobility management network element known to the visited session management network element in sub-scenario 2, or the home location.
  • the access and mobility management network element stores information about the visited session management network element.
  • H-AMF may also determine to select H-SMF and V-SMF based on the indication information for selecting the same SMF, old session ID, and V-SMF information (for example, from S707B).
  • S1120 to S1126 may refer to S1120 to S1126.
  • Sub-scenario 3 in scenario 2 of the embodiment shown in Fig. 8 is described below with reference to Fig. 12:
  • the correspondence between the network elements in Fig. 11 and the network elements in Fig. 8 can be referred to the above-mentioned Fig. 10, and will not be described again here.
  • S1201 to S1215 may refer to the above-mentioned S901 to S915, which are not shown here.
  • H-SMF sends a PDU session modification instruction to H-AMF.
  • H-SMF does not send V-SMF information to H-AMF.
  • H-SMF can also send indication information to H-AMF to select the same SMF for the new session.
  • H-SMF does not send V-SMF information to H-AMF, which corresponds to the home session management network element not notifying the home access and mobility management network elements of the visited session management network element in sub-scenario 3.
  • H-AMF sends a PDU session modification instruction to the UE.
  • the UE sends a PDU session establishment request to the H-AMF.
  • the PDU session establishment request contains the old session ID, that is, the ID of the session established before S902 in Figure 9.
  • the UE may also send indication information for selecting the same SMF to the H-AMF.
  • the UE sends a PDU session establishment request message to the H-AMF, corresponding to the terminal device establishing a new session (ie, the first session) in sub-scenario 3.
  • the old session corresponds to the second session in the above sub-scenario 3.
  • H-AMF determines to select H-SMF.
  • the H-AMF determines to select the H-SMF based on the old session ID. Among them, H-AMF did not perform the relevant steps in S704B to S708B mentioned above.
  • the H-AMF can also determine to select the H-SMF based on the indication information for selecting the same SMF and the old session ID.
  • H-AMF sends the old session ID to H-SMF.
  • H-SMF selects V-SMF based on the old session ID and the saved V-SMF information.
  • S1222 to S1227 may refer to S1021 to S1026.
  • FIG. 13 shows a possible exemplary block diagram of a communication device involved in the embodiment of the present application.
  • the device 1300 includes: a transceiver module 1320 and a processing module 1310.
  • the transceiver module 1320 may include a receiving unit and a sending unit.
  • the processing module 1310 is used to control and manage the actions of the device 1300 .
  • the transceiver module 1320 is used to support communication between the device 1300 and other network entities.
  • the device 1300 may also include a storage unit used to store program codes and data of the device 1300 .
  • each module in the device 1300 may be implemented by software.
  • the processing module 1310 may be a processor or a controller, such as a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing (DSP), or an application-specific integrated circuit (Application Specification).
  • CPU central processing unit
  • DSP digital signal processing
  • Application Specification application-specific integrated circuit
  • ASIC application-specific integrated circuit
  • FPGA field programmable gate array
  • the processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and so on.
  • the transceiver module 1320 may be a communication interface, a transceiver, or a transceiver circuit, etc., where the communication interface is a general term.
  • the communication interface may include multiple interfaces, and the storage unit may be a memory.
  • the processing module 1310 in the device 1300 can support the device 1300 to perform the actions of the home session management network element in the above method examples, for example
  • the device 1300 may be supported to perform step 610 in FIG. 6 or step 810 in FIG. 8 .
  • the transceiver module 1320 can support the device 1300 to communicate with the visited session management network element.
  • the transceiver module 1320 can support the device 1300 to perform steps 600 and 620 in Figure 6 or steps 800 and 820 in Figure 8 .
  • the transceiver module 1320 is used to receive the first session establishment request message, which is used to request the establishment of a session of the terminal device; the processing module 1310 is used to determine the visited session management network element; the transceiver module 1320 is used to Information about the user plane network element of the visited anchor point is obtained from the visited session management network element.
  • the information about the visited anchor point user plane network element may be the identity and/or address of the visited anchor point user plane network element.
  • the processing module 1310 is configured to determine the first visited public land mobile network based on the location of the terminal device when determining the visited session management network element. According to the first visited public land mobile network, The identifier of the mobile network acquires the information of the visited session management network element, and the visited session management network element is deployed in the first visited public land mobile network.
  • the processing module 1310 is used to obtain the corresponding relationship between the first service and the first visited public land mobile network; the first visited public land mobile network does not support the home user plane network. access the first service; when determining the first visited public land mobile network based on the location of the terminal device, determining the first visited public land mobile network based on the corresponding relationship and the location of the terminal device. network.
  • the processing module 1310 is configured to also obtain first indication information, where the first indication information is used to indicate that the first service passes through the anchor user plane network of the first visited public land mobile network. Meta access.
  • the transceiver module 1320 is configured to send a request message to the network storage function network element when obtaining the information of the visited session management network element according to the identity of the first visited public land mobile network.
  • the request message includes the identification of the first visited public land mobile network; the first visited public land mobile network The identity of the network is used to determine the visited session management network element; and a response message is received from the network storage function network element, where the response message includes information about the visited session management network element.
  • the transceiver module 1320 is configured to send the access and mobility management information to the home place when obtaining the information of the visited session management network element according to the identity of the first visited public land mobile network.
  • the network element sends a request message, where the request message includes the identifier of the first visited public land mobile network; the identifier of the first visited public land mobile network is used to determine the visited session management network element; from the The home access and mobility management network element receives a response message, where the response message includes information about the visited session management network element.
  • the request message also includes information about the visited user plane network element, and the first visited public land mobile network supports the visited user plane network element to access the first service, The information about the visited user plane network element is used to determine the visited session management network element.
  • the transceiver module 1320 is configured to send second instruction information to the visited session management network element, where the second instruction information instructs the visited session management network element to select the visited anchor. Click on the user plane network element and do not select the access distribution point.
  • the transceiving module 1320 is configured to send the location information of the terminal device to the visited session management network element, and the location information of the terminal device is used to select the visited anchor point user plane. network element.
  • the transceiving module 1320 is configured to send an identifier of the first service to the visited session management network element, and the identifier of the first service is used to select to support access to the first service.
  • the visited anchor point user plane network element is configured to send an identifier of the first service to the visited session management network element, and the identifier of the first service is used to select to support access to the first service.
  • the transceiver module 1320 is configured to send offloading rules to the home offloading point, where the offloading rules indicate that packets in the address range corresponding to the first visited public land mobile network are to be offloaded to the home offloading point. Visits the anchor point user plane network element.
  • the transceiver module 1320 is configured to receive the identifier of the first service requested by the terminal device to access; the processing module 1310 is configured to receive the identifier of the first service according to the identifier of the first service and the relationship between the first service and the public land mobile network of the first visited place. The corresponding relationship determines the visited session management network element.
  • the visited session management network element is deployed in the first visited public land mobile network.
  • the first visited public land mobile network does not support home user plane network element access.
  • the transceiver module 1320 is configured to obtain information about the visited anchor point user plane network element from the visited session management network element.
  • the processing module 1310 is configured to determine the visited session management network element according to the identification of the first service and the corresponding relationship between the first service and the first visited public land mobile network, Determine the first visited public land mobile network according to the identification of the first service and the corresponding relationship between the first service and the first visited public land mobile network; according to the first visited public land mobile network The identity of the mobile network obtains the information of the visited session management network element.
  • the transceiver module 1320 is configured to send a request message to the network storage function network element when obtaining the information of the visited session management network element according to the identity of the first visited public land mobile network.
  • the request message includes the identifier of the first visited public land mobile network; the identifier of the first visited public land mobile network is used to determine the visited session management network element; from the network storage function network The network element receives a response message, where the response message includes information about the visited session management network element.
  • the transceiver module 1320 is configured to send the access and mobility management information to the home place when obtaining the information of the visited session management network element according to the identity of the first visited public land mobile network.
  • the network element sends a request message, where the request message includes the identification of the first visited public land mobile network; the first visited public land mobile network The identification of the land mobile network is used to determine the visited session management network element; and a response message is received from the home access and mobility management network element, where the response message includes information about the visited session management network element.
  • the request message also includes information about the visited user plane network element, and the first visited public land mobile network supports the visited user plane network element to access the first service, The information about the visited user plane network element is used to determine the visited session management network element.
  • the processing module 1310 is used to obtain the address of the edge application server
  • the transceiving module 1320 is configured to send the address of the edge application server to the visited session management network element, and the address of the edge application server is used to select the visited anchor point user plane network element.
  • the transceiver module 1320 is configured to send instruction information to the visited session management network element, where the instruction information instructs the visited session management network element to select the visited anchor point user plane network. Yuan, do not choose to visit the diversion point.
  • the transceiving module 1320 is configured to send the location information of the terminal device to the visited session management network element, and the location information of the terminal device is used to select the visited anchor point user plane. network element.
  • the transceiving module 1320 is configured to send an identifier of the first service to the visited session management network element, and the identifier of the first service is used to select to support access to the first service.
  • the visited anchor point user plane network element is configured to send an identifier of the first service to the visited session management network element, and the identifier of the first service is used to select to support access to the first service.
  • the transceiver module 1320 is configured to, after determining the visited session management network element, and before obtaining the information about the visited anchor point user plane network element, the home access and mobility management network
  • the information of the visited session management network element is sent to the visited session management network element, and the information of the visited session management network element is used to establish a session of the terminal device.
  • the transceiver module 1320 is configured to, after determining the visited session management network element, and before obtaining the information about the visited anchor point user plane network element, send the home access and mobility management
  • the network element sends a session modification instruction, the session modification instruction is used to instruct the establishment of the first session; and receives a session management context message used to create the first session from the home access and mobility management network element, the The session management context message used to create the first session includes an identifier of the second session, and the second session is a session previously established by the terminal device with the home session management network element;
  • the processing module 1310 Determine the information of the visited session management network element according to the identifier of the second session and the corresponding relationship between the identifier of the second session and the information of the visited session management network element. Wherein, the corresponding relationship between the identifier of the second session and the identifier of the visited session management network element is stored in the context of the second session.
  • the device 1300 according to the embodiment of the present application may correspond to the home session management network element in the foregoing method embodiment, and the operations and/or functions of each module in the device 1300 are respectively to implement the home session in the foregoing method embodiment.
  • the corresponding steps of the method for managing network elements can also achieve the beneficial effects in the foregoing method embodiments. For the sake of simplicity, they will not be described again here.
  • the device 1300 according to the embodiment of the present application may correspond to the terminal equipment, home access and mobility management network element, network storage function network element, home distribution point, and visited anchor point user network element in the aforementioned method embodiment. etc., and the operations and/or functions of each module in the device 1300 are respectively to implement the steps of the corresponding equipment in the foregoing method embodiments.
  • the processing module 1310 in the device 1300 can support the device 1300 to perform the actions of the visited session management network element in the above method examples.
  • the transceiver module 1320 can support the device 1300 to communicate with the home session management network element.
  • the transceiver module 1320 can support the device 1300 to perform step 620 in Figure 6 and step 820 in Figure 8 .
  • Transceiver module 1320 configured to receive a first message from the home session management network element, where the first message is used to request or Modify and establish a session of the terminal device; the processing module 1310 is used to select the visited anchor user plane network element for the session; the transceiving module 1320 is used to send the visited anchor user plane to the home session management network element Network element information.
  • the processing module 1310 is configured to select the visited anchor point user plane network element and not select the visited offload point.
  • the transceiver module 1320 is configured to receive indication information from the home session management network element, where the indication information instructs the visited session management network element to select the visited anchor point user plane network element, Do not choose the diversion point to visit.
  • the transceiver module 1320 is configured to receive the identity of the first service from the home session management network element; the processing module 1310 is configured to select the visited anchor user plane network element for the session.
  • the visited anchor point user plane network element is selected according to the identifier of the first service, wherein the visited anchor point user plane network element is a visited anchor point user plane network that supports access to the first service. Yuan.
  • the transceiver module 1320 is configured to receive the address of the edge application server from the home session management network element;
  • the processing module 1310 is configured to select the visited anchor user plane network element according to the address of the edge application server when selecting the visited anchor user plane network element for the session, wherein the visited anchor user
  • the plane network element is a visited anchor point user plane network element that supports access to the edge application server.
  • the transceiver module 1320 is configured to receive the location information of the terminal device from the home session management network element; the processing module 1310 is configured to select the visited anchor point user interface for the session. When a network element is used, the user plane network element of the visited anchor point is selected according to the location information of the terminal device.
  • the device 1300 according to the embodiment of the present application may correspond to the visited session management network element in the foregoing method embodiment, and the operations and/or functions of each module in the device 1300 are respectively to implement the visited session in the foregoing method embodiment.
  • the corresponding steps of the method for managing network elements can also achieve the beneficial effects in the foregoing method embodiments. For the sake of simplicity, they will not be described again here.
  • the device 1300 according to the embodiment of the present application may correspond to the terminal equipment, home access and mobility management network element, network storage function network element, home distribution point, and visited anchor point user network element in the aforementioned method embodiment. etc., and the operations and/or functions of each module in the device 1300 are respectively to implement the steps of the corresponding equipment in the foregoing method embodiments.
  • Figure 14 shows a schematic structural diagram of a communication device 1400 according to an embodiment of the present application.
  • the device 1400 includes: a processor 1401.
  • the device 1400 is a home session management network element or a chip in the home session management network element
  • the processor 1401 is used to call an interface to perform the following actions:
  • Receive a first session establishment request message the first session establishment request message is used to request the establishment of a session of the terminal device; determine the visited session management network element; obtain the visited anchor point user plane network from the visited session management network element Yuan information.
  • the visited session management network element Receives the identification of the first service requested by the terminal device to access; determine the visited session management network element according to the identification of the first service and the corresponding relationship between the first service and the first visited public land mobile network, said The visited session management network element is deployed in the first visited public land mobile network, and the first visited public land mobile network does not support the home user plane network element to access the first service; from the visited place The session management network element obtains the information of the user plane network element of the visited anchor point.
  • the device 1400 can also be used to perform other steps and/or operations on the home session management network element side in the previous embodiments, which will not be described again here for the sake of brevity.
  • the device 1400 can also be used to execute terminal equipment, home access and mobility management network elements, network storage function network elements, home distribution points, and visited anchor point user networks in the foregoing method embodiments. corresponding steps and/or operations.
  • the device 1400 is a visited session management network element or a chip in a visited session management network element
  • the processor 1401 is used to call an interface to perform the following actions:
  • Receive the first message from the home session management network element the first message is used to request or modify the establishment of a session of the terminal device; select the visited anchor point user plane network element for the session; send the home session management network element to the home session management network element.
  • the user plane network element sends the information of the visited anchor point user plane network element.
  • the device 1400 can also be used to perform other steps and/or operations on the visited session management network element side in the previous embodiments, which will not be described again here for the sake of brevity.
  • the device 1400 can also be used to execute terminal equipment, home access and mobility management network elements, network storage function network elements, home distribution points, and visited anchor point user networks in the foregoing method embodiments. corresponding steps and/or operations.
  • the processor 1401 can call an interface to perform the above transceiver action, where the called interface can be a logical interface or a physical interface, which is not limited.
  • the physical interface can be implemented via transceivers.
  • the device 1400 further includes a transceiver 1403.
  • the device 1400 also includes a memory 1402, in which the program code in the above method embodiment can be stored, so that the processor 1401 can call it.
  • the device 1400 includes a processor 1401, a memory 1402, and a transceiver 1403, the processor 1401, the memory 1402, and the transceiver 1403 communicate with each other through internal connection paths to transmit control and/or data signals.
  • the processor 1401, the memory 1402 and the transceiver 1403 can be implemented on a chip.
  • the processor 1401, the memory 1402 and the transceiver 1403 can be implemented in the same chip, or they can be implemented in different chips. Or any two functions can be combined in one chip.
  • the memory 1402 can store program codes, and the processor 1401 calls the program codes stored in the memory 1402 to implement corresponding functions of the device 1400 .
  • the methods disclosed in the above embodiments of the present application can be applied in a processor or implemented by the processor.
  • the processor may be an integrated circuit chip that has signal processing capabilities. During the implementation process, each step of the above method embodiment can be completed through an integrated logic circuit of hardware in the processor or instructions in the form of software.
  • the above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (field programmable gate array, FPGA), or other available processors.
  • Programmable logic devices discrete gate or transistor logic devices, discrete hardware components, system on chip (SoC), central processor unit (CPU), or network processor (network processor) processor (NP), it can also be a digital signal processor (DSP), it can also be a microcontroller (micro controller unit, MCU), it can also be a programmable logic device (PLD) or other Integrated chip.
  • SoC system on chip
  • CPU central processor unit
  • NP network processor
  • DSP digital signal processor
  • MCU microcontroller
  • PLD programmable logic device
  • a general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.
  • the steps of the method disclosed in conjunction with the embodiments of the present application can be directly implemented by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor.
  • the software module can be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other mature storage media in this field.
  • the storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.
  • non-volatile memory can be read-only memory (ROM), programmable ROM (PROM), erasable programmable read-only memory (erasable PROM, EPROM), electrically removable memory. Erase electrically programmable read-only memory (EPROM, EEPROM) or flash memory. Volatile memory can be random access memory (RAM), which is used as an external cache.
  • RAM random access memory
  • RAM static random access memory
  • DRAM dynamic random access memory
  • SDRAM synchronous dynamic random access memory
  • double data rate SDRAM double data rate SDRAM
  • DDR SDRAM double data rate SDRAM
  • ESDRAM enhanced synchronous dynamic random access memory
  • SLDRAM synchronous link dynamic random access memory
  • direct rambus RAM direct rambus RAM
  • the system includes a home session management network element, a home access and mobility management network element, a terminal device, a home distribution point, a visited session management network element, and a network storage function network.
  • a home session management network element One or more of the user plane network elements of the visited anchor point and the visited anchor point user plane network element, wherein the terminal device is used to perform the steps and/or operations on the terminal device side in the previous embodiments, and the home session management network element is used
  • the home access and mobility management network element is used to perform the home access and mobility management network element side in the previous embodiments. steps and/or actions.
  • the size of the sequence numbers of the above-mentioned processes does not mean the order of execution.
  • the execution order of each process should be determined by its functions and internal logic.
  • the various numerical numbers or serial numbers involved in the above processes are only for convenience of description and should not constitute any limitation on the implementation process of the embodiments of the present application.
  • the above is an example of three elements A, B and C to illustrate the optional items of the project.
  • the disclosed systems, devices and methods can be implemented in other ways.
  • the device embodiments described above are only illustrative.
  • the division of the units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components may be combined or can be integrated into another system, or some features can be ignored, or not implemented.
  • the coupling or direct coupling or communication connection between each other shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the devices or units may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.
  • each functional unit in each embodiment of the present application can be integrated into one processing unit, each unit can exist physically alone, or two or more units can be integrated into one unit.
  • the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.
  • the technical solution of the present application is essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product.
  • the computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application.
  • the aforementioned storage media include: U disk, mobile hard disk, read-only memory ROM, random access memory RAM, magnetic disk or optical disk and other various media that can store program codes.

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Abstract

一种通信方法及装置，该方法包括：归属地会话管理网元接收第一会话建立请求消息，第一会话建立请求消息用于请求建立终端设备的会话，归属地会话管理网元确定拜访地会话管理网元，归属地会话管理网元从拜访地会话管理网元获得拜访地锚点用户面网元的信息。采用上述方法，可以实现在终端设备的会话建立流程中选择拜访地会话管理网元和拜访地锚点用户面网元，进而终端设备可以通过拜访地锚点用户面网元访问业务。

Description

一种通信方法及装置
相关申请的交叉引用
本申请要求在2022年05月02日提交中国专利局、申请号为202210477031.0、申请名称为“一种通信方法及装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及无线通信领域，尤其涉及一种通信方法及装置。
背景技术
边缘计算(edge computing，EC)业务往往对时延要求比较高，因此需要比较密集的部署移动边缘计算(mobile edge computing，MEC)平台。可是，在实际部署过程中，由于成本等原因的限制，很难实现单一运营商或第三方进行部署。一种合理的方式是，由多家运营商(或第三方)共同部署MEC平台(即边缘支持环境(edge hosting environment，EHE))，也就是说某种特定功能的MEC平台，或某个特定业务可能在不同位置由不同的运营商部署，或者该业务仅部署在部分运营商部署的MEC平台上，或该MEC平台仅由部分运营商部署。
而在上述部署模式下，假设终端设备所处位置部署运营商A的公共陆地移动网络(public land mobile network，PLMN)和运营商B的PLMN，且终端设备归属于运营商A。业务X部署于运营商B的MEC平台，其中，运营商B的MEC平台不支持运营商A的协议数据单元会话锚点(protocol data unit Session Anchor，PSA)接入，而在运营商A的MEC平台没有部署业务X或运营商A未部署MEC平台。
当终端设备请求访问业务X时，由于运营商B的MEC平台不支持运营商A的PSA接入，进而可能导致终端设备访问业务X的时延较高和/或可靠性较差。
发明内容
本申请提供一种通信方法及装置，用以解决由于部署某个业务的MEC平台不支持其他运营商的PSA接入，可能导致终端设备访问该业务时延较高和/或可靠性较差的问题。
第一方面，本申请提供一种通信方法，该方法包括：归属地会话管理网元接收第一会话建立请求消息，所述第一会话建立请求消息用于请求建立终端设备的会话；所述归属地会话管理网元确定拜访地会话管理网元；所述归属地会话管理网元从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息。
采用上述方法，可以实现在终端设备的会话建立流程中选择拜访地会话管理网元和拜访地锚点用户面网元，进而终端设备可以通过拜访地锚点用户面网元访问业务，因此能够提升终端设备访问拜访地部署的业务的可靠性，以及降低访问该业务的时延，解决了由于部署该业务(可以称为第一业务)的边缘应用服务器不支持归属地锚点用户面网元接入，导致终端设备访问该业务的时延较高和/或可靠性较差的问题。
其中，拜访地锚点用户面网元的信息可以为拜访地锚点用户面网元的标识和/或地址。
在一种可能的设计中，在所述归属地会话管理网元确定拜访地会话管理网元时，所述归属地会话管理网元根据所述终端设备的位置确定第一拜访地公共陆地移动网络，所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息，所述拜访地会话管理网元部署于所述第一拜访地公共陆地移动网络。
采用上述设计，归属地会话管理网元根据终端设备的位置选择拜访地公共陆地移动网络，并获取选择的拜访地公共陆地移动网络中部署的会话管理网元的信息。
在一种可能的设计中，还包括：所述归属地会话管理网元获取第一业务与所述第一拜访地公共陆地移动网络的对应关系；所述第一拜访地公共陆地移动网络不支持归属地用户面网元接入所述第一业务；在所述归属地会话管理网元根据所述终端设备的位置确定第一拜访地公共陆地移动网络时，所述归属地会话管理网元根据所述对应关系和/或所述终端设备的位置确定所述第一拜访地公共陆地移动网络。
采用上述设计，归属地会话管理网元可以获取业务与拜访地公共陆地移动网络的对应关系，进而根据该对应关系和终端设备的位置选择拜访地公共陆地移动网络。
在一种可能的设计中，所述归属地会话管理网元还获得第一指示信息，所述第一指示信息用于指示所述第一业务通过第一拜访地公共陆地移动网络的锚点用户面网元接入。
采用上述设计，归属地会话管理网元可以获知第一业务仅可以通过第一拜访地公共陆地移动网络的锚点用户面网元接入。
在一种可能的设计中，在所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息时，所述归属地会话管理网元向网络存储功能网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；所述归属地会话管理网元从所述网络存储功能网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
采用上述设计，归属地会话管理网元可以从网络存储功能网元获取拜访地会话管理网元的信息。
在一种可能的设计中，在所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息时，所述归属地会话管理网元向归属地接入和移动性管理网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；所述归属地会话管理网元从所述归属地接入和移动性管理网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
采用上述设计，归属地会话管理网元可以通过归属地接入和移动性管理网元从网络存储功能网元获取拜访地会话管理网元的信息。
在一种可能的设计中，所述请求消息还包括拜访地用户面网元的信息，所述第一拜访地公共陆地移动网络支持所述拜访地用户面网元接入所述第一业务，所述拜访地用户面网元的信息用于确定所述拜访地会话管理网元。所述拜访地用户面网元的信息包括所述拜访地用户面网元的标识和/或地址。
采用上述设计，拜访地用户面网元的信息可以辅助网络存储功能网元选择管理或控制该拜访地用户面网元的拜访地会话管理网元，进而实现拜访地用户面网元选择支持接入第 一业务的拜访地锚点用户面网元。
在一种可能的设计中，还包括：所述归属地会话管理网元还向所述拜访地会话管理网元发送第二指示信息，所述第二指示信息指示所述拜访地会话管理网元选择所述拜访地锚点用户面网元，不选择拜访地分流点。
在一种可能的设计中，还包括：所述归属地会话管理网元还向所述拜访地会话管理网元发送所述终端设备的位置信息，所述终端设备的位置信息用于选择所述拜访地锚点用户面网元。
示例性地，归属地会话管理网元向拜访地会话管理网元发送终端设备在归属地公共陆地移动网络中的位置信息，拜访地会话管理网元获取映射关系，拜访地会话管理网元可以根据终端设备在归属地公共陆地移动网络中的位置信息，以及映射关系，确定终端设备在第一拜访地公共陆地移动网络中的位置信息。该映射关系指示在归属地公共陆地移动网络中位置信息与在第一拜访地公共陆地移动网络中的位置信息的映射关系。
示例性地，归属地会话管理网元获取映射关系，归属地会话管理网元根据终端设备在归属地公共陆地移动网络中的位置信息，以及映射关系，确定终端设备在第一拜访地公共陆地移动网络中的位置信息。该映射关系指示在归属地公共陆地移动网络中位置信息与在第一拜访地公共陆地移动网络中的位置信息的映射关系。归属地会话管理网元向拜访地会话管理网元发送终端设备在第一拜访地公共陆地移动网络中的位置信息。
示例性地，终端设备的位置信息为终端设备的地理位置信息。例如，终端设备的经纬度信息。
在一种可能的设计中，还包括：所述归属地会话管理网元还向所述拜访地会话管理网元发送所述第一业务的标识，所述第一业务的标识用于选择支持接入所述第一业务的拜访地锚点用户面网元。
在一种可能的设计中，还包括：所述归属地会话管理网元向归属地分流点发送分流规则，所述分流规则指示将所述第一拜访地公共陆地移动网络对应的地址范围的报文分流至所述拜访地锚点用户面网元。
第二方面，本申请提供一种通信方法，该方法包括：归属地会话管理网元接收终端设备请求接入的第一业务的标识；所述归属地会话管理网元根据所述第一业务的标识，以及所述第一业务与第一拜访地公共陆地移动网络的对应关系确定拜访地会话管理网元，所述拜访地会话管理网元部署于所述第一拜访地公共陆地移动网络，所述第一拜访地公共陆地移动网络不支持归属地用户面网元接入所述第一业务；所述归属地会话管理网元从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息。
采用上述方法，可以实现在终端设备访问拜访地部署的业务(可以称为第一业务)时为终端设备选择拜访地会话管理网元和拜访地锚点用户面网元，进而终端设备可以通过拜访地锚点用户面网元访问该业务，因此能够提升终端设备访问该业务的可靠性，以及降低访问该业务的时延，解决了由于部署该业务的边缘应用服务器不支持归属地锚点用户面网元接入，导致终端设备访问该业务的时延较高和/或可靠性较差的问题。
在一种可能的设计中，在所述归属地会话管理网元根据所述第一业务的标识，以及所述第一业务与第一拜访地公共陆地移动网络的对应关系确定拜访地会话管理网元时，所述归属地会话管理网元根据所述第一业务的标识，以及所述第一业务与所述第一拜访地公共陆地移动网络的对应关系确定所述第一拜访地公共陆地移动网络；所述归属地会话管理网 元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息。
采用上述设计，归属地会话管理网元可以获知第一业务对应的拜访地公共陆地移动网络，并获取该拜访地公共陆地移动网络中部署的会话管理网元的信息。
在一种可能的设计中，在所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息时，所述归属地会话管理网元向网络存储功能网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；所述归属地会话管理网元从所述网络存储功能网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
采用上述设计，归属地会话管理网元可以从网络存储功能网元获取拜访地会话管理网元的信息。
在一种可能的设计中，在所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息时，所述归属地会话管理网元向归属地接入和移动性管理网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；所述归属地会话管理网元从所述归属地接入和移动性管理网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
采用上述设计，归属地会话管理网元可以通过归属地接入和移动性管理网元从网络存储功能网元获取拜访地会话管理网元的信息。
在一种可能的设计中，所述请求消息还包括拜访地用户面网元的信息，所述第一拜访地公共陆地移动网络支持所述拜访地用户面网元接入所述第一业务，所述拜访地用户面网元的信息用于确定所述拜访地会话管理网元。
采用上述设计，拜访地用户面网元的信息可以辅助网络存储功能网元选择管理或控制该拜访地用户面网元的拜访地会话管理网元，进而实现拜访地用户面网元选择支持接入第一业务的拜访地锚点用户面网元。
在一种可能的设计中，所述归属地会话管理网元获取边缘应用服务器的地址；所述归属地会话管理网元向所述拜访地会话管理网元发送所述边缘应用服务器的地址，所述边缘应用服务器的地址用于选择所述拜访地锚点用户面网元。
在一种可能的设计中，所述归属地会话管理网元还向所述拜访地会话管理网元发送指示信息，所述指示信息指示所述拜访地会话管理网元选择所述拜访地锚点用户面网元，不选择拜访地分流点。
在一种可能的设计中，所述归属地会话管理网元还向所述拜访地会话管理网元发送所述终端设备的位置信息，所述终端设备的位置信息用于选择所述拜访地锚点用户面网元。
在一种可能的设计中，所述归属地会话管理网元还向所述拜访地会话管理网元发送所述第一业务的标识，所述第一业务的标识用于选择支持接入所述第一业务的拜访地锚点用户面网元。
在一种可能的设计中，在所述归属地会话管理网元确定拜访地会话管理网元之后，在从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息之前，所述归属地会话管理网元向所述归属地接入和移动性管理网元发送所述拜访地会话管理网元的信息，所述拜访地会话管理网元的信息用于建立所述终端设备的会话。
采用上述设计可以实现归属地接入和移动性管理网元选择归属地会话管理网元和拜访地会话管理网元建立新会话，即第一会话。
在一种可能的设计中，在所述归属地会话管理网元确定拜访地会话管理网元之后，在从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息之前，所述归属地会话管理网元向所述归属地接入和移动性管理网元发送会话修改指令，所述会话修改指令用于指示建立第一会话；所述归属地会话管理网元从所述归属地接入和移动性管理网元接收用于创建所述第一会话的会话管理上下文消息，所述用于创建所述第一会话的会话管理上下文消息包括所述第二会话的标识，所述第二会话为所述终端设备之前与所述归属地会话管理网元建立的会话；所述归属地会话管理网元根据所述第二会话的标识，以及所述第二会话的标识和所述拜访地会话管理网元的信息的对应关系确定所述拜访地会话管理网元的信息。其中，所述第二会话的标识和所述拜访地会话管理网元的标识的对应关系保存于所述第二会话的上下文。
采用上述设计，归属地会话管理网元确定建立的新会话(即第一会话)需要选择旧会话(即第二会话)中的拜访地会话管理网元。
第三方面，本申请提供一种通信方法，该方法包括：拜访地会话管理网元从归属地会话管理网元接收第一消息，所述第一消息用于请求或修改建立终端设备的会话；所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元；所述拜访地会话管理网元向所述归属地会话管理网元发送所述拜访地锚点用户面网元的信息。
采用上述方法，拜访地会话管理网元为所述会话选择拜访地锚点用户面网元，进而终端设备可以通过拜访地锚点用户面网元访问业务，因此能够提升终端设备访问拜访地部署的业务的可靠性，以及降低访问该业务的时延。并且，拜访地会话管理网元不为所述会话选择拜访地分流点，而是归属地会话管理网元选择归属地分流点，进而该会话可以承载多种业务，既包括在归属地公共陆地移动网络部署的业务，也包括拜访地公共陆地移动网络部署的业务。
在一种可能的设计中，所述拜访地会话管理网元选择所述拜访地锚点用户面网元，不选择拜访地分流点。
在一种可能的设计中，所述拜访地会话管理网元从所述归属地会话管理网元接收指示信息，所述指示信息指示所述拜访地会话管理网元选择拜访地锚点用户面网元，不选择拜访地分流点；在所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元时，所述拜访地会话管理网元根据所述指示信息选择所述拜访地锚点用户面网元，不选择拜访地分流点。
在一种可能的设计中，所述拜访地会话管理网元从所述归属地会话管理网元接收第一业务的标识；在所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元时，所述拜访地会话管理网元根据所述第一业务的标识选择所述拜访地锚点用户面网元，其中，所述拜访地锚点用户面网元为支持接入所述第一业务的拜访地锚点用户面网元。
在一种可能的设计中，所述拜访地会话管理网元从所述归属地会话管理网元接收所述边缘应用服务器的地址；在所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元时，所述拜访地会话管理网元根据所述边缘应用服务器的地址选择所述拜访地锚点用户面网元，其中，所述拜访地锚点用户面网元为支持接入所述边缘应用服务器的拜访地锚点用户面网元。
在一种可能的设计中，所述拜访地会话管理网元从所述归属地会话管理网元接收所述终端设备的位置信息；在所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元时，所述拜访地会话管理网元根据所述终端设备的位置信息选择所述拜访地锚点用户面网元。
第四方面，本申请提供一种通信方法，该方法包括：
归属地接入和移动性管理网元从终端设备接收会话建立请求消息，所述会话建立请求消息包括第二会话的标识，所述第二会话为所述终端设备之前与归属地会话管理网元建立的会话；所述归属地接入和移动性管理网元根据所述第二会话的标识确定所述归属地会话管理网元和拜访地会话管理网元。
采用上述方法，归属地接入和移动性管理网元可以根据所述第二会话的标识确定所述归属地会话管理网元和拜访地会话管理网元，为终端设备创建新会话。
在一种可能的设计中，在所述归属地接入和移动性管理网元确定拜访地会话管理网元时，所述归属地接入和移动性管理网元从所述归属地会话管理网元接收所述拜访地会话管理网元的信息；或者，所述归属地接入和移动性管理网元从所述网络存储功能网元接收所述拜访地会话管理网元的信息。
采用上述方法，归属地接入和移动性管理网元可以采用不同方式获取拜访地会话管理网元的信息。
第五方面，本申请还提供一种装置。该装置可以执行上述方法设计。该装置可以是能够执行上述方法对应的功能的芯片或电路，或者是包括该芯片或电路的设备。
在一种可能的实现方式中，该装置包括：存储器，用于存储计算机可执行程序代码；以及处理器，处理器与存储器耦合。其中存储器所存储的程序代码包括指令，当处理器执行所述指令时，使该装置或者安装有该装置的设备执行上述任意一种可能的设计中的方法。
其中，该装置还可以包括通信接口，该通信接口可以是收发器，或者，如果该装置为芯片或电路，则通信接口可以是该芯片的输入/输出接口，例如输入/输出管脚等。
在一种可能的设计中，该装置包括相应的功能单元，分别用于实现以上方法中的步骤。功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。硬件或软件包括一个或多个与上述功能相对应的单元。
第六方面，本申请提供一种计算机可读存储介质，所述计算机可读存储介质存储有计算机程序，当所述计算机程序在装置上运行时，执行上述任意一种可能的设计中的方法。
第七方面，本申请提供一种计算机程序产品，所述计算机程序产品包括计算机程序，当所述计算机程序在装置上运行时，执行上述任意一种可能的设计中的方法。
第八方面，本申请提供一种通信系统，所述通信系统包括执行第二方面的装置、终端设备和/或执行第四方面的装置中的一个或多个装置。
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图1为本申请应用的移动通信系统的架构示意图；
图2为本申请应用的UPF三种形态的示意图；
图3为本申请中一种可能的应用场景的示意图；
图4为本申请中另一种可能的应用场景的示意图；
图5为本申请中终端设备1和终端设备2访问业务X的示意图；
图6为本申请中一种通信方法的概述流程图之一；
图7为本申请中在会话建立过程中选择V-SMF和V-PSA的示意图；
图8为本申请中一种通信方法的概述流程图之二；
图9为本申请中在场景1下UE访问业务1时选择V-SMF和V-PSA的示意图；
图10为本申请中在子场景1下在UE访问业务1时选择V-SMF和V-PSA的示意图；
图11为本申请中在子场景2下在UE访问业务1时选择V-SMF和V-PSA的示意图；
图12为本申请中在子场景3下在UE访问业务1时选择V-SMF和V-PSA的示意图；
图13为本申请中一种通信装置的结构示意图之一；
图14为本申请中一种通信装置的结构示意图之二。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。本申请的说明书和权利要求书及上述附图中的术语“第一”、第二”以及相应术语标号等是用于区别类似的对象，而不必用于描述特定的顺序或先后次序。应该理解这样使用的术语在适当情况下可以互换，这仅仅是描述本申请的实施例中对相同属性的对象在描述时所采用的区分方式。此外，术语“包括”和“具有”以及他们的任何变形，意图在于覆盖不排他的包含，以便包含一系列单元的过程、方法、系统、产品或设备不必限于那些单元，而是可包括没有清楚地列出的或对于这些过程、方法、产品或设备固有的其它单元。
在本申请的描述中，除非另有说明，“/”表示或的意思，例如，A/B可以表示A或B；本申请中的“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，在本申请的描述中，“至少一项”是指一项或者多项，“多项”是指两项或两项以上。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合。例如，a,b,或c中的至少一项(个)，可以表示：a,b,c,a-b,a-c,b-c,或a-b-c，其中a,b,c可以是单个，也可以是多个。
图1是本申请的实施例应用的移动通信系统的架构示意图。该通信系统包括终端设备(例如，用户设备(user equipment，UE))，网络设备(例如，接入网(access network，AN)设备或无线接入网(radio access network，AN)设备，以下以RAN为例进行说明)，核心网(Core network，CN)，数据网络(data network，DN)。在逻辑上，核心网的网元它们可以分为用户面和控制面两部分，控制面负责移动网络的管理，用户面负责业务数据的传输。
以下对图1中涉及的设备的功能进行简要说明。
其中，终端设备是移动用户与网络交互的入口，能够提供基本的计算能力，存储能力，向用户显示业务窗口，接收用户操作输入。下一代终端设备(NextGen UE)可以采用新空口技术，与RAN建立信号连接，数据连接，从而传输控制信号和业务数据到移动网络。终端设备可以包括各种具有无线通信功能的手持设备、车载设备、可穿戴设备、计算设备或连接到无线调制解调器的其它处理设备，以及各种形式的终端，移动台(mobile station，MS)，终端(terminal)，软终端等等，例如水表、电表、传感器等。
RAN：部署在靠近终端设备的位置，为特定区域的授权用户提供入网功能，并能够根据用户的级别，业务的需求等确定不同质量的传输隧道来传输用户数据。RAN能够管理自身的资源，合理利用，按需为终端设备提供接入服务，并负责把控制信号和用户数据在终端设备和核心网之间转发。
核心网：负责维护移动网络的签约数据，管理移动网络的网元，为终端设备提供会话管理，移动性管理，策略管理，安全认证等功能。在终端设备附着的时候，为终端设备提供入网认证；在终端设备有业务请求时，为终端设备分配网络资源；在终端设备移动的时候，为终端设备更新网络资源；在终端设备空闲的时候，为终端设备提供快恢复机制；在终端设备去附着的时候，为终端设备释放网络资源；在终端设备有业务数据时，为终端设备提供数据路由功能，如转发上行数据到数据网络；或者从数据网络接收终端设备的下行数据，转发到RAN，从而由RAN发送给终端设备。
数据网络(data network，DN)：为用户提供业务服务的数据网络，一般客户端位于终端设备，服务端位于数据网络。数据网络可以是私有网络，如局域网，也可以是不受运营商管控的外部网络，例如互联网(Internet)，还可以是运营商共同部署的专有网络，例如提供IP多媒体网络子系统(IP multimedia core network subsystem，IMS)服务的网络。
其中，核心网用户面包括用户面功能(user plane function，UPF)；核心网控制面包括接入和移动性管理功能(access and mobility management function，AMF)，会话管理功能(session management function，SMF)，统一数据管理(unified data management，UDM)，策略控制功能(policy control function，PCF)，应用功能(application function，AF)，认证服务器功能(authentication server function，AUSF)，网络切片选择功能(network slice selection function，NSSF)，网络切片选择的认证和授权功能(network slice-specific authentication and authorization function,NSSAAF)，网络切片准入控制功能(network slice admission control function，NSACF)。
核心网控制面采用服务化架构，控制面网元之间的交互采用服务调用的方式，来替换传统架构中的点对点通信方式。在服务化架构中，控制面网元会向其他控制面网元开放服务，供其他控制面网元调用；在点对点通信中，控制面网元之间通信接口会存储一套特定的消息，只能由接口两端的控制面网元在通信时使用。
以下对核心网中的功能实体的功能进行简单介绍：
1、会话管理网元：主要用于会话管理、终端设备的IP地址分配和管理、选择可管理用户设备平面功能、策略控制、或收费功能接口的终结点以及下行数据通知等。在5G通信中，会话管理网元可以是SMF网元，在未来通信如6G通信中，会话管理功能网元仍可以是SMF网元，或者有其它名称，本申请对此不作限定。Nsmf是SMF提供的基于服务的接口，SMF可以通过Nsmf与其他的网络功能通信。
2、接入管理网元：主要用于移动性管理和接入管理等，例如可以是4G通信网络中的移动性管理实体(mobility management entity，MME)功能或者5G网络中的AMF网元。在未来通信如6G通信中，接入管理网元仍可以是AMF网元，或者有其它名称，本申请对此不作限定。Namf是AMF提供的基于服务的接口，AMF可以通过Namf与其他的网络功能通信。
3、策略控制网元：用于指导网络行为的统一策略框架，为控制平面功能网元(例如AMF，SMF等)提供策略规则信息等。在5G通信中，策略控制网元可以是PCF网元，在 未来通信如6G通信中，策略控制网元仍可以是PCF网元，或者有其它名称，本申请对此不作限定。其中Npcf是PCF提供的基于服务的接口，PCF可以通过Npcf与其他的网络功能通信。
4、数据管理网元：用于处理用户标识、签约、接入鉴权、注册、或移动性管理等。在5G通信中，数据管理网元可以是UDM网元，在未来通信如6G通信中，数据管理网元仍可以是UDM网元，或者有其它名称，本申请对此不作限定。其中Nudm是UDM提供的基于服务的接口，UDM可以通过Nudm与其他的网络功能通信。
5、应用网元：用于进行应用影响的数据路由，接入网络开放功能，或与策略框架交互进行策略控制等。在5G通信中，应用网元可以是AF网元，在未来通信如6G通信中，应用网元仍可以是AF网元，或者有其它名称，本申请对此不作限定。Naf是AF提供的基于服务的接口，AF可以通过Naf与其他的网络功能通信。
6、用户面网元：用于分组路由和转发、或用户面数据的服务质量(quality of service，QoS)处理等。在5G通信中，用户面网元可以是用户面功能(user plane function，UPF)网元，在未来通信如6G通信中，用户面网元仍可以是UPF网元，或者有其它名称，本申请对此不作限定。
7、认证服务网元：主要用于用户鉴权等。在5G通信中，认证服务网元可以是AUSF网元，在未来通信如6G通信中，认证服务网元仍可以是AUSF网元，或者有其它名称，本申请对此不作限定。Nausf是AUSF提供的基于服务的接口，AUSF可以通过Nausf与其他的网络功能通信。
8、网络切片选择功能网元：用于为终端设备选择网络切片，在5G通信中，网络切片选择功能网元可以是NSSF网元，在未来通信如6G通信中，网络切片选择功能网元仍可以是NSSF网元，或者有其它名称，本申请对此不作限定。
9、网络切片选择的认证和授权功能网元：用于为终端设备进行切片鉴权。
可以理解的是，图1仅为举例，核心网还可以包括更多或更少的网元，本申请对此不作限定。
本申请实施例提供的技术方案可以应用于各种通信系统。例如：可以适用于LTE系统或5G系统，也可以适用于其它面向未来的新系统等。本申请实施例对此不作具体限定。此外，术语“系统”可以和“网络”相互替换。
为便于理解本申请实施例，对本申请实施例中涉及的几个基本概念做简单说明。
1.UPF的几种形态
UPF的形态可以包含一般的UPF、PSA、本地PSA、分流点(例如，上行分类器(uplink classifier user plane function，UL CL)和分支点(branch point，BP)等)，如下表1对PSA、本地PSA、分流点进行说明。
表1

其中，AN和UPF之间的接口可以为N3接口，例如，图2中的RAN和ULCL之间的接口。任意两个UPF之间的接口可以为N9接口，例如，图2中的UL CL与本地PSA之间的接口，以及UL CL与PSA之间的接口。PSA和DN之间的接口可以为N6接口，例如，图2中的PSA和Internet之间接口以及本地PSA和本地DN之间的接口。可以理解的是，上述接口名称仅为举例，随着网络的演进还可能为其他接口名称，本申请对此不作限定。
如图2所示为上行分类器(uplink classifier user plane function，UL CL)的网络架构示意图。在图2中，UE1希望访问非EC业务(例如，Internet)。UE1通过AN向UL CL发送上行数据，UL CL根据该上行数据的特征将该上行数据分流至PSA，则进一步由PSA转发至Internet。类似的，PSA接收到Internet的下行数据，并将下行数据转发至UL CL，UL CL通过AN将下行数据转发至UE1。
UE2希望访问EC业务(例如，本地DN)。UE2通过AN向UL CL发送上行数据，UL CL根据该上行数据的特征将该上行数据分流至本地PSA，并进一步由本地PSA转发至本地DN。类似的，本地PSA接收到本地DN的下行数据，并将下行数据转发至UL CL UPF，UL CL通过AN将下行数据转发至UE2。
2.使用边缘应用服务器发现网元(edge application server discovery function，EASDF)的EAS发现
在4G及之前的传统移动网络架构和部署中，用户面设备基本遵从树形拓扑部署。上行用户报文经过基站及回程网络，最终通过集中部署的锚点网关接入数据网络。其中，这些锚点网关一般部署在网络中较高的位置，如大区中心机房等。上述部署方式相对简单，便于运营商在锚点网关处进行集中业务管控和报文处理。
随着移动业务流量的爆炸式增长，上述部署方式越来越难以支撑快速增长的移动业务流量。一方面，在锚点网关集中部署式的网络中，增长的流量最终集中在锚点网关及核心机房处，对回程网络带宽、机房吞吐量和网关规格提出的要求越来越高；另一方面，从接入点到锚点网关的长距离回程网络以及复杂的传输环境，也导致了用户报文传输的较大时延和抖动。
基于以上背景，业界提出了边缘计算(edge computing，EC)的概念。EC通过将用户面设备及业务处理能力下移到网络边缘，实现了分布式业务流量的本地处理，避免了流量的过度集中，从而大大降低了对核心机房和锚点网关的规格需求。同时，也缩短了回程网络的距离，降低了用户报文传输的时延和抖动，使得超低时延业务的部署成为可能。
在EC部署场景中，某些业务可能会由多个部署于网络边缘的EAS提供服务。这些EAS提供相同的业务和内容，但是具有不同的IP地址。当终端设备需要接入该业务时，EC场景要求其接入距离终端设备较近的可用EAS。因此，终端设备需要获取恰当的EAS IP地址。
第三代合作伙伴计划(3rd generation partnership project，3GPP)标准TS 23.548定义了辅助EAS发现的新网元，即边缘应用服务器发现网元(edge application server discovery function，EASDF)，其主要作用为根据会话管理网元的指示处理域名服务器(domain name server，DNS)消息。
具体可以包括：EASDF接收来自于终端设备的DNS查询(query)消息。该DNS查询消息包括终端设备请求访问的业务的标识，例如全量域名(full qualified domain name，FQDN)。
EASDF向会话管理网元发送终端设备请求访问的业务的标识，并从会话管理网元获取DNS扩展机制客户端子网选项(extended mechanisms for DNS-client-subnet option，ECS option)。其中，ECS option是国际互联网工程任务组(the internet engineering task force，IETF)定义的一种DNS消息扩展项，用来表征终端设备的位置，以辅助DNS服务器解析终端设备本地的EAS IP地址。进一步地，EASDF可以在DNS查询消息中添加ECS option，并将添加ECS option的DNS查询转发到DNS服务器，以及将来自于DNS服务器的DNS响应(response)消息转发到终端设备。其中，DNS响应消息包括EAS IP地址。
或者，EASDF向会话管理网元发送终端设备请求访问的业务的标识，并从会话管理网元获取本地DNS(local DNS)地址。其中，本地DNS地址是部署在终端设备本地的DNS服务器，因此即使DNS查询消息中不包含表征终端设备位置的信息，接收DNS查询消息本地DNS服务器也会根据自身的位置，解析终端设备本地的EAS IP地址。进一步地，EASDF将DNS查询转发到本地DNS地址对应DNS服务器，以及将来自于该DNS服务器的DNS响应消息转发到终端设备。其中，DNS响应消息包括EAS IP地址。
3.归属地PLMN和拜访地PLMN
在某个国家或地区，某个运营商的某种制式的蜂窝移动通信网络称为PLMN。
终端设备签约的PLMN称为归属地PLMN(Home PLMN，HPLMN)，表征签约用户的归属运营商部署的网络。此外，归属地PLMN又可称为家乡PLMN，是终端设备首选接入的PLMN。
在本申请中，拜访地PLMN可以理解为除归属地PLMN之外的PLMN，又可称为非归属地PLMN，或者除归属地PLMN之外的部署EC业务的PLMN，且所述EC业务不支持归属地PLMN的用户面网元接入，或者除归属地PLMN之外的能够访问EC业务的PLMN，且所述EC业务不支持归属地PLMN的用户面网元访问。
此外，为了区分上述两种PLMN，归属地PLMN又可称为第一PLMN，拜访地PLMN又可称为第二PLMN。
进一步地，拜访地网元可以理解除归属地PLMN之外的PLMN中部署的网元。拜访地网元可以包括拜访地会话管理网元、拜访地用户面网元(例如，拜访地锚点用户面网元)等。
在归属地PLMN称为第一PLMN，拜访地PLMN称为第二PLMN时，归属地会话管理网元是指第一PLMN中部署的会话管理网元，拜访地会话管理网元是指第二PLMN中部署的会话管理网元；归属地用户面网元是指第一PLMN中部署的用户面网元，拜访地用户面网元是指第二PLMN中部署的用户面网元。其中，拜访地锚点用户面网元是指第二PLMN中部署的锚点用户面网元。
作为本申请一种可能的应用场景，如图3所示为包括UL CL的网络架构，部分网元已省略。在该场景下，采用本申请图6和图8所示的实施例，归属地会话管理网元(如图2中的HPLMN中SMF)确定拜访地会话管理网元(如图2中的VPLMN中SMF)，并通过拜访地会话管理网元获取拜访地锚点用户面网元(如图2中的L-PSA)的信息。归属地会 话管理网元选择归属地分流点(如图2中的UL CL)和拜访地锚点用户面网元为终端设备创建会话，用于实现终端设备通过拜访地锚点用户面网元访问第一业务。其中，拜访地锚点用户面网元支持访问第一业务的边缘应用服务器(edge application server，EAS)(如图2中的EAS)或部署第一业务的EHE。上述具体流程还可以参考图7和图9所示实施例。
作为本申请另一种可能的应用场景，如图4所示为不包括UL CL的网络架构，部分网元已省略。在该场景下，采用本申请图8所示的实施例，归属地会话管理网元(如图4中的HPLMN中SMF)确定拜访地会话管理网元(如图4中的VPLMN中SMF)，并通过拜访地会话管理网元获取拜访地锚点用户面网元(如图4中的L-PSA)的信息。归属地会话管理网元选择归属地用户面网元(如图4中的HPLMN中UPF)和拜访地锚点用户面网元(如图4中的L-PSA)为终端设备创建会话，用于实现终端设备通过拜访地锚点用户面网元访问第一业务。其中，拜访地锚点用户面网元支持访问第一业务的EAS(如图3中的EAS)或部署第一业务的EHE。上述具体流程还可以参考图10至图12所示实施例。
对于本申请中的第一业务，需要说明如下两点：
第一，第一拜访地公共陆地移动网络不支持(或允许)归属地用户面网元接入第一业务；或者，还可以理解为，第一拜访地公共陆地移动网络不支持除第一拜访地公共陆地移动网络之外的其他PLMN中的用户面网元接入第一业务；或者，还可以理解为，仅允许第一拜访地公共陆地移动网络中的部分用户面网元接入第一业务；或者，还可以理解为，第一拜访地公共陆地移动网络的EHE仅允许第一拜访地公共陆地移动网络的锚点用户面网元(例如PSA)接入。
第二，归属地公共陆地移动网络的EHE没有部署第一业务，或归属地公共陆地移动网络未部署EHE。
如图5所示，假设终端设备1和终端设备2所处位置部署有运营商A的PLMN和运营商B的PLMN，且终端设备1归属于运营商A，终端设备2归属于运营商B。其中，业务X部署于运营商B的MEC平台，其中，运营商B的MEC平台不支持运营商A的UPF接入(也即仅支持运营商B的本地UPF接入)，运营商A未部署MEC平台。
当终端设备1访问业务X时，由于运营商B的MEC平台不支持运营商A的UPF接入，进而导致终端设备访问业务X的时延较高和/或可靠性较差。也就是说，终端设备可能无法访问业务X，或者终端设备无法接入与自身位置距离较近的部署业务X的平台(例如，运营商B的MEC平台)，或无法接入与自身位置距离较近的部署业务X的EAS，而只能接入与自身位置距离较远的部署业务X的平台，进而导致终端设备1访问业务X时延较高和/或可靠性较差。
当终端设备2访问业务X时，由于运营商B的MEC平台仅支持运营商B的本地PSA接入，终端设备2归属于运营商B，终端设备2可以通过本地PSA访问部署业务X的MEC平台。
基于此，本申请提供一种通信方法，用以解决由于部署某个业务的MEC平台不支持其他运营商的PSA接入，可能导致终端设备访问该业务时延较高和/或可靠性较差的问题。
如图6所示，该方法包括：
步骤600：终端设备向归属地会话管理网元发送会话建立请求消息，会话建立请求消息用于请求建立终端设备的会话。
示例性地，终端设备可以通过归属地接入和移动性管理网元向归属地会话管理网元发送会话建立请求消息。
步骤610：归属地会话管理网元确定拜访地会话管理网元。
以下结合第一种可能的实现方式、第二种可能的实现方式和第三种可能的实现方式对归属地会话管理网元确定拜访地会话管理网元进行说明：
第一种可能的实现方式：归属地会话管理网元根据终端设备的位置确定第一拜访地公共陆地移动网络。进一步地，归属地会话管理网元根据第一拜访地公共陆地移动网络的标识获取拜访地会话管理网元的信息，拜访地会话管理网元部署于第一拜访地公共陆地移动网络。
示例性地，归属地会话管理网元可以根据终端设备的位置确定终端设备所处位置对应的拜访地公共陆地移动网络，将终端设备所处位置对应的拜访地公共陆地移动网络作为第一拜访地公共陆地移动网络。
其中，终端设备所处位置对应的拜访地公共陆地移动网络可以是指终端设备所处位置有覆盖(或部署)的拜访地公共陆地移动网络。
此外，终端设备所处位置对应的拜访地公共陆地移动网络可以为N个，N为正整数，则第一拜访地公共陆地移动网络的数量可以为M个，M为正整数，M≤N。也就是说，归属地会话管理网元可以根据终端设备的位置确定一个或多个拜访地公共陆移动网络。为便于描述，该实施例以所述第一拜访地公共陆地移动网络和所述第一拜访地会话管理网元均为一个进行描述。应理解，当所述第一拜访地公共陆地移动网络和所述第一拜访地会话管理网元为多个时，相关动作在每个第一拜访地会话管理网元中均可以执行，或在所述归属地会话管理网元和每个第一拜访地会话管理网元之间均可以执行。
例如，在UE所处的位置部署了PLMN 1和PLMN 2，其中，UE归属于PLMN 1，PLMN 1为归属地公共陆地移动网络，PLMN 2为拜访地公共陆地移动网络。归属地会话管理网元根据UE的位置确定PLMN 2，并根据PLMN 2的标识获取拜访地会话管理网元的信息，拜访地会话管理网元部署于PLMN 2。
又例如，在UE所处的位置部署了PLMN 1、PLMN 2和PLMN 3，其中，UE归属于PLMN 1，PLMN 1为归属地公共陆地移动网络，PLMN 2和PLMN 3为拜访地公共陆地移动网络。归属地会话管理网元根据UE的位置确定PLMN 2和PLMN 3，并根据PLMN 2的标识获取拜访地会话管理网元1的信息，拜访地会话管理网元1部署于PLMN 2，以及根据PLMN 3的标识获取拜访地会话管理网元2的信息，拜访地会话管理网元2部署于PLMN 3。
在一种可能的实现方式中，在归属地会话管理网元确定终端设备所处位置对应的拜访地公共陆地移动网络之后，归属地会话管理网元还可以从上述确定出的拜访地公共陆地移动网络中筛选出与归属地公共陆地移动网络存在合作关系的拜访地公共陆地移动网络，例如与归属地公共陆地移动网络签署服务水平协议(Service Level Agreement，SLA)的拜访地公共陆地移动网络。归属地会话管理网元可以将筛选出的拜访地公共陆地移动网络作为第一拜访地公共陆地移动网络。
第二种可能的实现方式：归属地会话管理网元可以获取第一业务与第一拜访地公共陆地移动网络的对应关系。归属地会话管理网元还可以根据终端设备的位置，以及第一业务与第一拜访地公共陆地移动网络的对应关系确定第一拜访地公共陆地移动网络。进一步地， 归属地会话管理网元可以根据第一拜访地公共陆地移动网络的标识获取拜访地会话管理网元的信息，拜访地会话管理网元部署于第一拜访地公共陆地移动网络。
示例性地，归属地会话管理网元可以本地配置或从应用功能网元接收第一业务与第一拜访地公共陆地移动网络的对应关系，本申请不限定归属地会话管理网元获取该对应关系的具体方式。
其中，第一业务与第一拜访地公共陆地移动网络的对应关系可以包含在EAS部署信息(EAS deployment information，EDI)中。也就是说，EDI包括第一业务与第一拜访地公共陆地移动网络的对应关系。例如，EDI包括第一业务的FQDN与第一拜访地公共陆地移动网络的标识。一种可能的实施方式为，EDI包括业务X(第一业务的一例)的FQDN与PLMN2(第一拜访地公共陆地移动网络的一例)的对应关系，其中业务X为仅允许拜访地PLMN2的PSA接入的业务。本申请不限定上述对应关系的具体形式。此外，EDI还可以包括DN名称(data network name DNN)，单个网络切片选择辅助信息(single network slice selection assistance information，S-NSSAI)，DNS服务器信息，EAS IP范围，和/或EDI的组标识等。本申请对EDI包括的具体参数不作限定。可以理解的是，第一业务与第一拜访地公共陆地移动网络的对应关系还可以包含在其他信息中，本申请对此不作限定。
需要说明的是，上述对应关系或包括该对应关系的EDI可以针对多个或全部终端设备有效，不限于步骤600所涉及的会话或终端设备。此外，获取和存储该对应关系或包括该对应关系的EDI粒度也不限于步骤600所涉及的会话或终端设备。
可以理解的是，对于本实施例，在终端设备的会话建立过程中(也即在终端设备发起访问业务之前)，归属地会话管理网元为该会话选择拜访地会话管理网元，并从拜访地会话管理网元获得拜访地锚点用户面网元的信息，进而为终端设备提前建立访问第一业务的路径。当终端设备发起访问第一业务时，终端设备可以通过之前建立的访问第一业务的路径访问第一业务。此外，终端设备也可能直至该会话被释放，也未发起访问第一业务。
此外，归属地会话管理网元还可以获得第一指示信息，该第一指示信息用于指示第一业务通过第一拜访地公共陆地移动网络的锚点用户面网元接入。示例性地，归属地会话管理网元可以接收EDI，EDI包括第一业务与第一拜访地公共陆地移动网络的对应关系，和第一指示信息。
示例性地，在归属地会话管理网元可以根据该对应关系和终端设备的位置确定第一拜访地公共陆地移动网络时，归属地会话管理网元可以首先根据终端设备的位置确定终端设备所处位置对应的拜访地公共陆地移动网络，然后根据第一业务与第一拜访地公共陆地移动网络的对应关系以及终端设备所处位置对应的拜访地公共陆地移动网络确定第一拜访地公共陆地移动网络，例如，在终端设备所处位置对应的拜访地公共陆地移动网络包括第一拜访地公共陆地移动网络时，归属地会话管理网元选择第一拜访地公共陆地移动网络。
例如，在UE所处的位置部署了PLMN 1、PLMN 2和PLMN 3，其中，UE归属于PLMN 1，PLMN 1为归属地公共陆地移动网络，PLMN 2和PLMN 3为拜访地公共陆地移动网络。其中，PLMN 2部署了只支持PLMN 2的PSA接入的业务X，但是PLMN 1未部署业务X。归属地会话管理网元获取业务X与PLMN 2的对应关系，则根据UE的位置和该对应关系确定PLMN 2，并根据PLMN 2的标识获取拜访地会话管理网元的信息，拜访地会话管理网元部署于PLMN 2。
此外，可以理解的是，在上述第二种可能的实现方式中，归属地会话管理网元还可以 结合与归属地公共陆地移动网络存在合作关系的拜访地公共陆地移动网络确定第一拜访地公共陆地移动网络，此处不再赘述。
与上述第二种可能的实现方式类似，作为一种可选的实现方式(即第三种可能的实现方式)，第一业务与第一拜访地公共陆地移动网络的对应关系可以替换为第一业务与拜访地用户面网元的对应关系(包括第一业务与拜访地用户面网元、第一拜访地公共陆地移动网络的对应关系)，此时，归属地会话管理网元可以根据终端设备的位置，以及第一业务与拜访地用户面网元的对应关系确定拜访地用户面网元。进一步地，归属地会话管理网元可以根据拜访地用户面网元的信息获取拜访地会话管理网元的信息，拜访地用户面网元和拜访地会话管理网元部署于同一拜访地公共陆地移动网络。
其中，第一业务与拜访地用户面网元的对应关系可以理解为第一拜访地公共陆地移动网络支持拜访地用户面网元接入第一业务。也可以理解为，第一拜访地公共陆地移动网络支持归属地公共陆地移动网络通过拜访地用户面网元接入第一业务，或者第一拜访地公共陆地移动网络支持除第一拜访地公共陆地移动网络之外的其他公共陆地移动网络通过拜访地用户面网元接入第一业务等。
其中，第一业务与第一拜访地公共陆地移动网络的对应关系可以包含在EDI或其他信息中，第一业务与第一拜访地公共陆地移动网络的对应关系可以在归属地会话管理网元本地配置，或从应用功能网元获取，或从统一数据存储库(unified data repository，UDR)网元或统一数据管理(unified data management，UDM)网元获取，本申请对此不作限定。
对于上述三种实现方式或者其他实现方式，归属地会话管理网元获取拜访地会话管理网元的信息可以采用但不限于以下方式：
方式1：归属地会话管理网元可以从网络存储功能网元获取拜访地会话管理网元的信息。示例性地，拜访地会话管理网元的信息可以包括拜访地会话管理网元的标识和/或地址。
示例性地，归属地会话管理网元可以向网络存储功能网元发送请求消息，请求消息包括第一拜访地公共陆地移动网络的标识和/或拜访地用户面网元的信息。在网络存储功能网元在接收到请求消息之后，网络存储功能网元向归属地会话管理网元发送响应消息，响应消息包括拜访地会话管理网元的信息。
其中，第一拜访地公共陆地移动网络的标识用于确定拜访地会话管理网元。拜访地用户面网元的信息用于确定拜访地会话管理网元，其中，拜访地用户面网元的信息可以辅助网络存储功能网元选择管理或控制该拜访地用户面网元的拜访地会话管理网元，进而实现拜访地用户面网元选择支持接入第一业务的拜访地锚点用户面网元。
此外，该请求消息还可以包括其他内容，例如，终端设备的位置信息，DNN，S-NSSAI等，本申请对此不作限定。
可以理解的是，上述网络存储功能网元可以为拜访地网络存储功能网元或归属地网络存储功能网元，本申请对此不作限定。
上述方式1的相关内容还可以具体可以参考下述图7中的S704A至S706A。
方式2：归属地会话管理网元可以通过归属地接入和移动性管理网元获取拜访地会话管理网元的信息。示例性地，拜访地会话管理网元的信息可以包括拜访地会话管理网元的标识和/或地址。
示例性地，归属地会话管理网元向归属地接入和移动性管理网元发送第一请求消息，第一请求消息包括第一拜访地公共陆地移动网络的标识和/或拜访地用户面网元的信息。其 中，关于第一请求消息的相关内容具体可以参考上述方式1中的相关描述。
在归属地接入和移动性管理网元从归属地会话管理网元接收第一请求消息之后，归属地接入和移动性管理网元可以采用但不限于以下方式获取并反馈拜访地会话管理网元的信息。
方式A，归属地接入和移动性管理网元可以本地配置公共陆地移动网络的标识与会话管理网元的信息的对应关系，进而归属地接入和移动性管理网元可以根据该请求消息中的第一拜访地公共陆地移动网络的标识确定相应的拜访地会话管理网元。和/或，归属地接入和移动性管理网元本地配置用户面网元的地址与会话管理网元的信息的对应关系，进而归属地接入和移动性管理网元可以根据该请求消息中的拜访地用户面网元的信息确定相应的拜访地会话管理网元。归属地接入和移动性管理网元向归属地会话管理网元发送针对第一请求消息的响应消息，针对第一请求消息的响应消息包括拜访地会话管理网元的信息。
方式B，归属地接入和移动性管理网元向网络存储功能网元发送第二请求消息，第二请求消息可以包括第一请求消息包括的内容。网络存储功能网元向归属地接入和移动性管理网元发送针对第二请求消息的响应消息，针对第二请求消息的响应消息包括拜访地会话管理网元的信息。归属地接入和移动性管理网元向归属地会话管理网元发送针对第一请求消息的响应消息，针对第一请求消息的响应消息包括拜访地会话管理网元的信息。上述相关内容还可以具体可以参考下述图7中的S704B至S708B。
方式3：归属地会话管理网元可以本地配置公共陆地移动网络的标识与会话管理网元的信息的对应关系，进而归属地会话管理网元可以根据第一拜访地公共陆地移动网络的标识确定相应的拜访地会话管理网元。或者，归属地会话管理网元可以本地配置用户面网元的地址与会话管理网元的信息的对应关系，进而归属地会话管理网元可以根据该请求消息中的拜访地用户面网元的信息确定相应的拜访地会话管理网元。
步骤620：归属地会话管理网元从拜访地会话管理网元获得拜访地锚点用户面网元的信息。
示例性地，归属地会话管理网元向拜访地会话管理网元发送会话建立请求消息，拜访地会话管理网元选择拜访地锚点用户面网元，具体地，拜访地会话管理网元不选择拜访地分流点。拜访地会话管理网元向归属地会话管理网元发送会话建立响应消息，会话建立响应消息包括拜访地锚点用户面网元的信息。
此外，归属地会话管理网元还可以向拜访地会话管理网元发送以下一项或多项内容，下述均用以辅助拜访地会话管理网元选择拜访地锚点用户面网元，下述内容可以由会话建立请求消息携带或单独发送，本申请对此不作限定。
在一种可能的实现方式中，归属地会话管理网元还可以向拜访地会话管理网元发送第二指示信息。第二指示信息指示拜访地会话管理网元选择拜访地锚点用户面网元，不选择拜访地分流点。
在一种可能的实现方式中，归属地会话管理网元还可以向拜访地会话管理网元发送第一业务的标识，第一业务的标识用于选择支持接入第一业务的拜访地锚点用户面网元。
在一种可能的实现方式中，归属地会话管理网元还可以向拜访地会话管理网元发送终端设备的位置信息，终端设备的位置信息用于选择拜访地锚点用户面网元。
可以理解的是，终端设备的位置信息可以为跟踪区信息，或小区的标识，或数据网络接入标识等中的至少一个。但是，在不同的公共陆地移动网络中，对于同一终端设备的位 置信息的定义可能并不相同。例如，对于同一个终端设备，终端设备在PLMN A中跟踪区信息，与终端设备在PLMN B中跟踪区信息并不相同，也就是说，PLMN B中的会话管理网元无法理解PLMN A中的会话管理网元发送的终端设备在PLMN A中跟踪区信息。
基于此，本申请实施例提供如下几种解决方案，以使拜访地会话管理网元能够理解归属地会话管理网元发送的终端设备的位置信息。
方案1：归属地会话管理网元向拜访地会话管理网元发送终端设备在归属地公共陆地移动网络中的位置信息，拜访地会话管理网元获取映射关系，拜访地会话管理网元可以根据终端设备在归属地公共陆地移动网络中的位置信息，以及映射关系，确定终端设备在第一拜访地公共陆地移动网络中的位置信息。
示例性地，终端设备的位置信息包括在归属地公共陆地移动网络中的跟踪区信息，或小区的标识，或数据网络接入标识中的至少一项。该映射关系指示在归属地公共陆地移动网络中位置信息与在第一拜访地公共陆地移动网络中的位置信息的映射关系。其中，该映射关系可以是拜访地会话管理网元本地配置或应用功能网元发送的，本申请不限定拜访地会话管理网元获取该映射关系的具体方式。
例如，拜访地会话管理网元获取归属地公共陆地移动网络的TAI与第一拜访地公共陆地移动网络的DNAI的映射关系，拜访地会话管理网元可以根据终端设备在归属地公共陆地移动网络中的TAI，以及该映射关系，就可以确定终端设备在第一拜访地公共陆地移动网络DNAI。
方案2：归属地会话管理网元获取映射关系，归属地会话管理网元根据终端设备在归属地公共陆地移动网络中的位置信息，以及映射关系，确定终端设备在第一拜访地公共陆地移动网络中的位置信息。归属地会话管理网元向拜访地会话管理网元发送终端设备在第一拜访地公共陆地移动网络中的位置信息。
示例性地，终端设备的位置信息包括在第一拜访地公共陆地移动网络中的跟踪区信息，或小区的标识，或数据网络接入标识中的至少一项。其中，该映射关系的相关内容可以参考方案1中的描述。
例如，归属地会话管理网元获取归属地公共陆地移动网络的TAI与第一拜访地公共陆地移动网络的DNAI的映射关系，归属地会话管理网元可以根据终端设备在归属地公共陆地移动网络中的TAI，以及该映射关系，就可以确定终端设备在第一拜访地公共陆地移动网络DNAI。归属地会话管理网元向拜访地会话管理网元发送终端设备在第一拜访地公共陆地移动网络DNAI。
方案3：终端设备的位置信息为终端设备的地理位置信息。例如，终端设备的经纬度信息。
示例性地，归属地会话管理网元将终端设备在归属地公共陆地移动网络中的位置信息，转换为终端设备的地理位置信息，并将终端设备的地理位置信息发送至拜访地会话管理网元。拜访地会话管理网元将接收到的终端设备的地理位置信息转换为终端设备在第一拜访地公共陆地移动网络中的位置信息。
进一步地，在步骤620之后，或者在步骤600之后，归属地会话管理网元选择归属地分流点(例如图3中的UL CL)、归属地锚点用户面网元(例如图3中的HPLMN中的PSA)和归属地边缘应用服务器发现网元(例如图3中的HPLMN中的EASDF)等。进一步地，在获取拜访地锚点用户面网元的信息之后，归属地会话管理网元向归属地分流点发送分流 规则，分流规则指示将第一拜访地公共陆地移动网络对应的地址范围的报文分流至拜访地锚点用户面网元，也可以描述为分流规则指示将终端设备的位置对应的地址范围的报文分流至拜访地锚点用户面网元。其中，第一拜访地公共陆地移动网络对应的地址范围是指第一拜访地公共陆地移动网络部署的业务的IP地址范围，例如，第一拜访地公共陆地移动网络部署的EAS或EHE的IP地址。第一拜访地公共陆地移动网络对应的地址范围的报文是指报文的目的IP地址落入第一拜访地公共陆地移动网络对应的地址范围的报文。例如，归属地分流点接收第一报文，根据第一拜访地公共陆地移动网络对应的地址范围和第一报文的目标IP地址，确定第一报文的目标IP地址落入该地址范围，则归属地分流点将第一报文发送至拜访地锚点用户面网元。
在另一种可能的情况中，分流规则指示将第一业务的地址范围的报文分流至拜访地锚点用户面网元。其中，归属地会话管理网元可以根据EDI确定该第一业务的地址范围，也可以通过其他方式确定，本申请不进行限制。
类似的，终端设备的位置对应的地址范围是指终端设备所在位置部署的EAS或EHE的IP地址。终端设备的位置对应的地址范围的报文是指报文的目的IP地址落入终端设备的位置对应的地址范围的报文。
需要说明的是，作为一种可能的场景，归属地会话管理网元可以选择或不选择归属地锚点用户面网元，如果不选择归属地锚点用户面网元，则归属地分流点可以直接连接拜访地边缘应用服务器发现网元。例如，图3中HPLMN中的PSA为可选的网元，当HPLMN中的SMF未选择PSA时，HPLMN中作为UL CL的H-UPF也可以同时作为H-PSA，直接连接H-EASDF。
进一步地，终端设备在访问第一业务时，终端设备可以通过归属地分流点向拜访地锚点用户面网元(例如图3中的VPLMN中的L-PSA)发送上行数据，拜访地锚点用户面网元将接收到的上行数据发送至部署第一业务的边缘应用服务器(例如图3中的VPLMN中的EAS)，同时，部署第一业务的边缘应用服务器将需要发送给终端设备的下行数据，通过拜访地锚点用户面网元发送至归属地分流点，归属地分流点将接收到的下行数据转发至终端设备。
采用上述方法，可以实现在终端设备的会话建立流程中选择拜访地会话管理网元和拜访地锚点用户面网元，进而终端设备可以通过拜访地锚点用户面网元访问业务，因此能够提升终端设备访问拜访地部署的业务的可靠性，以及降低访问该业务的时延，解决了由于部署该业务(可以称为第一业务)的边缘应用服务器不支持归属地锚点用户面网元接入，导致终端设备访问该业务的时延较高和/或可靠性较差的问题。
以下结合图7对图6所示实施例进行示例性说明：
其中，H-SMF对应图6所示实施例中的归属地会话管理网元，V-SMF对应图6所示实施例中的拜访地会话管理网元。H-NRF对应图6所示实施例中的网络存储功能网元。V-AMF对应图6所示实施例中的归属地接入与移动性管理网元。H-UL CL为图6所示实施例中的归属地分流点，H-PSA为图6所示实施例中的归属地锚点用户面网元，H-EASDF对应图6所示实施例中的归属地边缘应用服务器发现网元。V-PSA为图8所示实施例中的拜访地锚点用户面网元。
S701：可选地，H-SMF获取EDI，EDI中包含业务X与PLMN1ID的对应关系。
其中，业务X可以为上述图6中第一业务的一例，相应的，PLMN1为上述图6中的 第一拜访地公共陆地移动网络。
S702:UE向H-SMF发送PDU会话建立请求。
其中，PDU会话建立请求可以为上述步骤600的一种可能实现方式。
下述S703至S706A，或者S703至S708B为步骤610的两种可能的实现方式。
S703:H-SMF确定PLMN1。
若未执行S701，H-SMF根据UE的位置部署的PLMN，以及与HPLMN存在合作关系PLMN，确定要选择哪些(一个或多个)PLMN。作为示例，所述合作关系可以是漫游协议。以下仅以H-SMF确定PLMN1和确定插入H-UL CL为例进行说明。
若执行S701，H-SMF还可以根据业务X与PLMN1ID的对应关系确定PLMN1，其中，PLMN1还为UE的位置部署的PLMN，以及与HPLMN存在合作关系PLMN。
进一步地，H-SMF获得V-SMF的信息，具体包括上述S704A至S706A，或者S704B至S708B。
S704A：H-SMF向H-NRF发送网元发现请求(Nnrf_NFDiscovery_Request)消息，该消息用于请求V-SMF的信息。
该消息可以包括UE的位置信息，PLMN1ID。该消息还可以包括DNN，S-NSSAI。
可选的，该消息可以包括V-UPF的地址。V-UPF为PLMN1中的UPF。
其中，网元发现请求消息可以为上述归属地会话管理网元获取拜访地会话管理网元的信息的方式1中请求消息的一种可能实现方式。
S705A：H-NRF获取V-SMF的信息。
例如，V-SMF的信息包括V-SMFID和/或地址。V-SMF为PLMN1中的SMF。
S706A：H-NRF向H-SMF发送网元发现响应(Nnrf_NFDiscovery_Response)消息。
该消息包括V-SMF的信息。
其中，网元发现响应消息可以为上述归属地会话管理网元获取拜访地会话管理网元的信息中方式1中响应消息的一种可能实现方式。
S704B：H-SMF向H-AMF发送PDU会话上下文状态通知请求(Nsmf_PDUSession_SMContextStatusNotify Request)消息。
该消息包括PLMN1ID，还可以包括选择V-SMF的指示信息。
其中，PDU会话上下文状态通知请求消息可以为上述归属地会话管理网元获取拜访地会话管理网元的信息的方式2中第一请求消息的一种可能实现方式。
S705B：H-AMF向H-NRF发送网元发现请求消息，该消息用于请求V-SMF的信息。
该消息内容与S704A相同。
其中，网元发现请求消息可以为上述归属地会话管理网元获取拜访地会话管理网元的信息中方式2中的第二请求消息的一种可能实现方式。
S706B：H-NRF获取V-SMF的信息。
S707B：H-NRF向H-AMF发送网元发现响应消息。
该消息内容与S706A相同。
其中，网元发现响应消息可以为上述归属地会话管理网元获取拜访地会话管理网元的信息中方式2中的第二响应消息的一种可能实现方式。
S708B：H-AMF向H-SMF发送PDU会话上下文状态通知响应(Nsmf_PDUSession_SMContextStatusNotify Response)消息。
该消息包括V-SMF的信息。
其中，PDU会话上下文状态通知响应消息可以为上述归属地会话管理网元获取拜访地会话管理网元的信息中方式2中的第一响应消息的一种可能实现方式。
S709：H-SMF向V-SMF发送PDU会话建立请求(Nsmf_PDUSession_Create Request)消息。
其中，PDU会话建立请求消息可以为上述步骤820中归属地会话管理网元为了获得拜访地锚点用户面网元的信息向拜访地会话管理网元发送的消息的一种可能实现方式。
此外，H-SMF还可以向V-SMF发送其他信息，具体可参考步骤620。
S710：V-SMF选择V-PSA，但不选择V-UL CL/BP。
S711：V-SMF向H-SMF发送PDU会话建立响应(Nsmf_PDUSession_Create Response)消息，该消息包括V-PSA的信息。例如，V-PSA的信息包括V-PSA的标识和/或地址。
其中，PDU会话建立请求消息可以为上述步骤820中拜访地会话管理网元向归属地会话管理网元发送拜访地锚点用户面网元的信息的一种可能实现方式。
上述S709至S711为步骤620的一种可能的实现方式。
S712：H-SMF选择H-UL CL，H-PSA，H-EASDF，以及向H-UL CL发送分流规则。
该分流规则指示PLMN1对应的IP地址范围的报文分流至V-PSA。也就是说，H-UL CL确定接收到的报文的目标IP地址落入PLMN1对应的IP地址范围，H-UL CL将该报文转发至V-PSA。例如，PLMN1对应的IP地址范围可以为部署业务X的MEC平台的IP地址范围，或业务X的EAS的IP地址范围。
S713：H-SMF向UE发送PDU会话建立接受消息。该消息包括H-EASDF的地址。
采用上述设计，可以在UE建立会话时选择V-SMF和V-PSA，进而UE可以通过V-PSA访问业务X，能够提升UE访问业务X的可靠性，以及降低访问业务X的时延。
基于此，本申请提供还一种通信方法，用以解决由于部署某个业务的MEC平台不支持其他运营商的PSA接入，可能导致终端设备访问该业务时延较高和/或可靠性较差的问题。
如图8所示，该方法包括：
步骤800：归属地会话管理网元接收终端设备请求接入的第一业务的标识。
示例性地，终端设备向归属地边缘应用服务器发现网元发送域名系统查询(DNS Query)消息，该消息包括第一业务的标识，例如，第一业务的FQDN。归属地边缘应用服务器发现网元向归属地会话管理网元发送第一业务的标识。
需要说明的是，不同于图6所示实施例，在本实施例中，终端设备访问第一业务。
步骤810：归属地会话管理网元根据第一业务的标识，以及第一业务与第一拜访地公共陆地移动网络的对应关系确定拜访地会话管理网元。拜访地会话管理网元部署于第一拜访地公共陆地移动网络，第一拜访地公共陆地移动网络不支持归属地用户面网元接入第一业务。
在一种可能的实现方式中，归属地会话管理网元根据第一业务的标识，以及第一业务与第一拜访地公共陆地移动网络的对应关系确定第一拜访地公共陆地移动网络，第一拜访地公共陆地移动网络为终端设备所处位置对应的拜访地公共陆地移动网络。进一步地，归属地会话管理网元可以根据第一拜访地公共陆地移动网络的标识获取拜访地会话管理网 元的信息，拜访地会话管理网元部署于第一拜访地公共陆地移动网络。
其中，关于第一业务与第一拜访地公共陆地移动网络的对应关系，以及归属地会话管理网元如何获取该对应关系可以参考上述步骤610中的第二种可能的实现方式中的相关描述。此外，归属地会话管理网元还可以获取第一指示信息，可以参考上述步骤610中的第二种可能的实现方式中的相关描述。
示例性地，归属地会话管理网元根据第一业务的标识，查询是否保存一业务与第一拜访地公共陆地移动网络的对应关系。若保存，则归属地会话管理网元确定第一拜访地公共陆地移动网络。同时，归属地会话管理网元还可以根据终端设备的位置确定终端设备所处位置对应的拜访地公共陆地移动网络，以及确定第一拜访地公共陆地移动网络为终端设备所处位置对应的拜访地公共陆地移动网络中的一个。此外，归属地会话管理网元还可以结合与归属地公共陆地移动网络存在合作关系的拜访地公共陆地移动网络，确定第一拜访地公共陆地移动网络为与归属地公共陆地移动网络存在合作关系的拜访地公共陆地移动网络。
在另一种可能的实现方式中，归属地会话管理网元可以根据第一业务的标识，以及第一业务与拜访地用户面网元的对应关系确定拜访地用户面网元。进一步地，归属地会话管理网元可以根据拜访地用户面网元的信息获取拜访地会话管理网元的信息，拜访地用户面网元和拜访地会话管理网元部署于同一拜访地公共陆地移动网络。
其中，关于第一业务与拜访地用户面网元的对应关系可以参考上述步骤610中的第三种可能的实现方式中的相关描述。
示例性地，归属地会话管理网元根据第一业务的标识，查询是否保存一业务与拜访地用户面网元的对应关系。若保存，则归属地会话管理网元确定拜访地用户面网元。
对于上述两种实现方式或者其他实现方式，归属地会话管理网元获取拜访地会话管理网元的信息可以参考步骤610中归属地会话管理网元获取拜访地会话管理网元的信息的方式1至方式3。
步骤820：归属地会话管理网元从拜访地会话管理网元获得拜访地锚点用户面网元的信息。
其中，步骤820可以应用于两种不同的可能实现场景，也即图8所示的实施例可以应用于两种不同的可能实现场景。
场景1：归属地会话管理网元选择归属地分流点，用于实现终端设备通过拜访地锚点用户面网元访问第一业务。此时，步骤820可以参考上述步骤620中的相关描述，重复之处不再赘述。具体可以参考图3所示的网络架构。
此外，在一种可能的设计中，归属地会话管理网元还可以获取边缘应用服务器的地址。具体可以参考图9中的S910至S915。归属地会话管理网元还可以向拜访地会话管理网元发送边缘应用服务器的地址，边缘应用服务器的地址用于选择拜访地锚点用户面网元。此时，归属地会话管理网元根据边缘应用服务器的地址插入归属地分流点，在归属地会话管理网元向归属地分流点发送分流规则时，分流规则指示将该边缘应用服务器的地址的报文分流至拜访地锚点用户面网元。其中，边缘应用服务器的地址可以是边缘应用服务器的IP地址，边缘应用服务器的地址的报文是报文的目标IP地址落入边缘应用服务器的地址的报文。
下文将结合图9对上述场景进行说明。
场景2：归属地会话管理网元指示终端设备创建第一会话。其中，第一会话为新的会话。此时，步骤820之前的操作均是在第二会话中执行，而步骤820是执行第一会话的建立。该场景下，归属地会话管理网元没有直接为第二会话选择归属地分流点。其中，第二会话为终端设备之前与归属地会话管理网元建立的会话，也即第二会话为旧会话，且第二会话并未被释放。其中，第一会话为终端设备与归属地会话管理网元和拜访地会话管理网元建立的会话，第二会话也为终端设备与归属地会话管理网元和拜访地会话管理网元建立的会话。
可以理解的是，归属地会话管理网元可以根据第二会话的上下文确定拜访地会话管理网元的信息。第二会话可以在第一会话建立后释放，或者在到达预设时长时释放，本申请对此不作限定。此外，终端设备还可以根据第一会话访问在归属地公共陆地移动网络部署的业务。
示例性地，场景1具体可以包括3个子场景：
子场景1：归属地会话管理网元通知归属地接入和移动性管理网元拜访地会话管理网元的信息，用于实现归属地接入和移动性管理网元在建立新会话(即第一会话)时选择归属地会话管理网元和拜访地会话管理网元，也即是重用第二会话中的归属地会话管理网元，和选择的拜访地会话管理网元。
示例性地，在归属地会话管理网元确定拜访地会话管理网元之后，在从拜访地会话管理网元获得拜访地锚点用户面网元的信息之前，归属地会话管理网元向归属地接入和移动性管理网元发送拜访地会话管理网元的信息，拜访地会话管理网元的信息用于建立第一会话。
子场景2：归属地会话管理网元不通知归属地接入和移动性管理网元拜访地会话管理网元的信息，归属地接入和移动性管理网元已知拜访地会话管理网元的信息或者说归属地接入和移动性管理网元存储有拜访地会话管理网元的信息。例如，在上述步骤610和步骤810中归属地会话管理网元获取拜访地会话管理网元的信息中的方式2中的内容。归属地接入和移动性管理网元获取过拜访地会话管理网元的信息，并可以存储该拜访地会话管理网元的信息。归属地接入和移动性管理网元可以在建立新会话(即第一会话)时选择归属地会话管理网元和拜访地会话管理网元。
子场景3：归属地会话管理网元不通知归属地接入和移动性管理网元拜访地会话管理网元的信息，归属地接入和移动性管理网元未获知拜访地会话管理网元的信息，归属地会话管理网元确定建立的新会话时选择旧会话中的拜访地会话管理网元。
示例性地，在归属地会话管理网元确定拜访地会话管理网元之后，在从拜访地会话管理网元获得拜访地锚点用户面网元的信息之前，归属地会话管理网元向归属地接入和移动性管理网元发送会话修改指令，会话修改指令用于指示建立第一会话。归属地会话管理网元从归属地接入和移动性管理网元接收用于创建第一会话的会话管理上下文消息，用于创建第一会话的会话管理上下文消息包括第二会话的标识，第二会话为终端设备之前与归属地会话管理网元建立的会话，且第二会话未被释放。归属地会话管理网元根据第二会话的标识，以及第二会话的标识和拜访地会话管理网元的信息的对应关系确定拜访地会话管理网元的信息。其中，第二会话的标识和拜访地会话管理网元的标识的对应关系保存于第二会话的上下文。
下文结合图10至图12对上述子场景1至子场景3进行说明。
采用上述方法，可以实现在终端设备访问拜访地部署的业务(可以称为第一业务)时为终端设备选择拜访地会话管理网元和拜访地锚点用户面网元，进而终端设备可以通过拜访地锚点用户面网元访问该业务，因此能够提升终端设备访问该业务的可靠性，以及降低访问该业务的时延，解决了由于部署该业务的边缘应用服务器不支持归属地锚点用户面网元接入，导致终端设备访问该业务的时延较高和/或可靠性较差的问题。
以下结合图9对图8所示实施例的场景1进行说明：
其中，H-SMF对应图8所示实施例中的归属地会话管理网元，V-SMF对应图8所示实施例中的拜访地会话管理网元。H-NRF对应图8所示实施例中的网络存储功能网元。V-AMF对应图8所示实施例中的归属地接入与移动性管理网元。H-UL CL为图8所示实施例中的归属地分流点，H-PSA为图8所示实施例中的归属地锚点用户面网元，H-EASDF对应图8所示实施例中的归属地边缘应用服务器发现网元。V-PSA为图8所示实施例中的拜访地锚点用户面网元。
S901：H-SMF获取业务X与PLMN1ID的对应关系。其中，PLMN1不是UE接入的PLMN。作为一种可能的示例，业务X与PLMN1ID的对应关系可以包含在EDI中。
其中，业务X可以为上述图8中第一业务的一例，相应的，PLMN1为上述图8中的第一拜访地公共陆地移动网络。
UE执行PDU会话建立流程。可以理解的是，此处为非漫游的会话建立流程。
S902:UE向H-EASDF发送DNS Query消息。该消息包括业务X的FQDN。
S903:H-EASDF向H-SMF发送FQDN。
其中，通过上述S902和S903可以作为步骤800的一种可能的实现方式。
示例性地，H-EASDF将DNS Query中的FQDN与DNS处理规则进行匹配，如果匹配成功则向H-SMF报此FQDN。
下述S904至S907A，或者S904至S909B为步骤810的两种可能的实现方式。
S904:H-SMF确定PLMN1。
示例性地，H-SMF根据FQDN，业务X与PLMN1ID的对应关系确定PLMN1。
其中，PLMN1为UE的位置部署的PLMN，以及与HPLMN存在合作关系PLMN。
S905A至S907A可以参考上述S704A至S706A。S905B至809A可以参考上述S704B至S708B。H-SMF获得V-SMF的信息，具体包括上述S905A至S907A，或S905B至S909B。
S910：H-SMF向V-SMF发送请求消息，该请求消息用于请求ECS option或L-DNS地址，此外，该请求消息还可以包括授权策略和/或UE的位置信息。其中，授权策略指示允许通过V-PSA接入业务，或允许H-SMF获取PLMN1对应的ECS option/L-DNS地址。UE的位置信息可以参考上述图6所示实施例中终端设备的位置信息的相关内容。
S911：V-SMF向H-SMF发送ECS option或L-DNS地址。
S912：H-SMF向H-EASDF发送ECS option或L-DNS地址。
S913：H-EASDF向DNS发送DNS Query消息。
若H-SMF向H-EASDF发送ECS option，DNS Query消息包括ECS option。
若H-SMF向H-EASDF发送L-DNS地址，H-EASDF向L-DNS发送DNS Query消息即此时的DNS为L-DNS。
S914：H-EASDF从DNS接收DNS Response消息。DNS Response消息包括EAS IP地址。
S915：H-EASDF向H-SMF发送EAS IP地址。
示例性地，H-EASDF将DNS Response消息中的EAS IP地址与DNS处理规则进行匹配，如果匹配成功则缓存此DNS Response消息并向H-SMF上报此EAS IP地址。
上述S910至S915为归属地会话管理网元获取边缘应用服务器的地址的一种可能的实现方式。
S916：H-SMF向V-SMF发送EAS IP地址和/或目标DNAI。目标DNAI为H-SMF根据该EAS IP地址确定的DNAI。该DNAI可以是HPLMN或PLMN1对应的DNAI，具体实施方式可参考步骤620中所述方案1或方案2。
示例性地，EAS IP地址和/或目标DNAI可以通过PDU会话建立请求消息携带，本申请对携带上述内容的消息不作限定。
此外，H-SMF还可以向V-SMF发送其他信息，具体可参考步骤620。例如，H-SMF可以向V-SMF发送指示信息，该指示信息指示V-SMF选择V-UPF，不选择V-UL CL或BP。
S917：V-SMF选择V-PSA，但不选择V-UL CL/BP。
S918：V-SMF向H-SMF发送V-PSA的信息。
上述S916至S918为步骤820的一种可能的实现方式。
例如，V-PSA的信息包括V-PSA的标识和/或地址。
示例性地，V-PSA的信息可以由PDU会话建立响应消息携带，本申请对携带V-PSA的信息的消息不作限定。
S919：H-SMF选择H-UL CL，H-PSA，H-EASDF，以及向H-UL CL发送分流规则。
该分流规则指示目标DNAI对应的IP地址范围的报文分流至V-PSA，或者，EAS IP地址对应的IP地址范围的报文分流至V-PSA。
S920：H-SMF向H-EASDF发送DNS上下文更新请求(NeasdfDNS Context_Update Request)消息。
该消息用于指示H-EASDF向UE转发DNS Response消息。
S921：H-EASDF向H-SMF发送DNS上下文更新响应(NeasdfDNS Context_Update Response)消息。
S922：H-EASDF向UE转发DNS Response消息。
采用上述实施例，可以实现在UE访问业务X时为UE选择V-SMF和V-PSA，进而UE可以通过V-PSA访问业务X，能够提升UE访问业务X的可靠性，以及降低访问业务X的时延。
以下结合图10对图8所示实施例的场景2中的子场景1进行说明：
其中，H-SMF对应图8所示实施例中的归属地会话管理网元，V-SMF对应图8所示实施例中的拜访地会话管理网元。V-AMF对应图8所示实施例中的归属地接入与移动性管理网元。H-PSA为图8所示实施例中的归属地锚点用户面网元，H-EASDF对应图8所示实施例中的归属地边缘应用服务器发现网元。V-PSA为图8所示实施例中的拜访地锚点用户面网元。
S1001至S1015可以参考上述S901至S915，此处未画出。
S1016:H-SMF向H-AMF发送PDU会话修改指令和V-SMF的信息。
可选的，H-SMF还可以向H-AMF发送新会话选择相同SMF的指示信息。
例如，上述内容可以由N1N2消息传输(Namf_Communication_N1N2MessageTransfer)消息携带。
其中，H-SMF向H-AMF发送V-SMF的信息，对应在子场景1中归属地会话管理网元通知归属地接入和移动性管理网元拜访地会话管理网元的信息。
S1017：H-AMF向UE发送PDU会话修改指令(PDU session modification command)。
例如，H-AMF通过非接入层(non-access stratum，NAS)消息向UE发送PDU会话修改指令。
S1018：UE向H-AMF发送PDU会话建立请求消息，PDU会话建立请求消息包含旧会话ID，即如图9中在S902之前建立的会话的ID。
其中，UE向H-AMF发送PDU会话建立请求消息，对应在子场景1中终端设备建立新会话(即第一会话)。其中，旧会话对应上述子场景1中的第二会话。
可选的，UE还可以向H-AMF发送选择相同SMF的指示信息。
S1019：H-AMF确定选择H-SMF和V-SMF。
示例性地，H-AMF根据旧会话ID，V-SMF的信息(来自于S1016)确定选择H-SMF和V-SMF。
因此，H-AMF根据从H-SMF获得的V-SMF的信息确定选择V-SMF。
可选的，H-AMF还可以根据选择相同SMF的指示信息，旧会话ID，V-SMF的信息(来自于S1016)确定选择H-SMF和V-SMF。
S1020：H-AMF向H-SMF发送旧会话ID。
例如，旧会话ID可以由PDU会话创建会话管理上下文(Nsmf_PDUSession_CreateSMContext)消息携带。
S1021：H-SMF选择H-UPF。
S1022：H-SMF向V-SMF发送PDU会话建立请求消息。
S1023：V-SMF选择V-PSA并配置N4规则，选择V-EASDF并配置DNS处理规则。
S1024：V-SMF向H-SMF发送PDU会话建立响应消息，该消息包括V-PSA的地址和V-EASDF的地址。
S1025：H-SMF和V-SMF建立隧道信息。
示例性地，H-SMF和V-SMF可以交换UPF的地址等信息，以建立用户面路径。具体的，H-SMF向V-SMF发送H-UPF的地址，V-SMF向V-PSA发送H-UPF的地址，H-SMF向H-UPF发送V-PSA和(R)AN的地址，H-SMF向(R)AN发送H-UPF的地址。
S1026：H-SMF向UE发送PDU会话建立接受消息，该消息包括V-EASDF的地址信息。
以下结合图11对图8所示实施例的场景2中的子场景2进行说明：其中，图11中网元与图8中网元的对应关系可以参考上述图10，此处不再赘述。
S1101至S1115可以参考上述S901至S915，此处未画出。
S1116:H-SMF向H-AMF发送PDU会话修改指令。
可选的，H-SMF还可以向H-AMF发送新会话选择相同SMF的指示信息。
其中，H-SMF不向H-AMF发送V-SMF的信息，对应在子场景2中归属地会话管理网元不通知归属地接入和移动性管理网元拜访地会话管理网元的信息。
S1117：H-AMF向UE发送PDU会话修改指令。
S1118：UE向H-AMF发送PDU会话建立请求，PDU会话建立请求包含旧会话ID，即如图9中在S902之前建立的会话的ID。
可选的，UE还可以向H-AMF发送选择相同SMF的指示信息。
其中，UE向H-AMF发送PDU会话建立请求消息，对应在子场景2中终端设备建立新会话(即第一会话)。其中，旧会话对应上述子场景2中的第二会话。
S1119：H-AMF确定选择H-SMF和V-SMF。
示例性地，H-AMF根据旧会话ID，V-SMF的信息(例如，来自于S707B)确定选择H-SMF和V-SMF。
示例性地，H-AMF执行S704B至S708B，保存V-SMF的信息，对应上述在子场景2中归属地接入和移动性管理网元已知拜访地会话管理网元的信息或者说归属地接入和移动性管理网元存储有拜访地会话管理网元的信息。
可选的，H-AMF还可以根据选择相同SMF的指示信息，旧会话ID，V-SMF的信息(例如，来自于S707B)确定选择H-SMF和V-SMF。
S1120至S1126可以参考S1120至S1126。
以下结合图12对图8所示实施例的场景2中的子场景3进行说明：其中，图11中网元与图8中网元的对应关系可以参考上述图10，此处不再赘述。
S1201至S1215可以参考上述S901至S915，此处未画出。
S1216:H-SMF向H-AMF发送PDU会话修改指令。
其中，H-SMF不向H-AMF发送V-SMF的信息。
可选的，H-SMF还可以向H-AMF发送新会话选择相同SMF的指示信息。
其中，H-SMF不向H-AMF发送V-SMF的信息，对应在子场景3中归属地会话管理网元不通知归属地接入和移动性管理网元拜访地会话管理网元的信息。
S1217：H-AMF向UE发送PDU会话修改指令。
S1218：UE向H-AMF发送PDU会话建立请求，PDU会话建立请求包含旧会话ID，即如图9中在S902之前建立的会话的ID。
可选的，UE还可以向H-AMF发送选择相同SMF的指示信息。
其中，UE向H-AMF发送PDU会话建立请求消息，对应在子场景3中终端设备建立新会话(即第一会话)。其中，旧会话对应上述子场景3中的第二会话。
S1219：H-AMF确定选择H-SMF。
示例性地，H-AMF根据旧会话ID确定选择H-SMF。其中，H-AMF未执行上述S704B至S708B中的相关步骤。
可选的，H-AMF还可以根据选择相同SMF的指示信息，旧会话ID确定选择H-SMF。
S1220：H-AMF向H-SMF发送旧会话ID。
S1221：H-SMF根据旧会话ID，以及保存的V-SMF的信息选择V-SMF。
S1221对应归属地会话管理网元确定建立的新会话时选择旧会话中的拜访地会话管理网元。
S1222至S1227可以参考S1021至S1026。
采用上述实施例，可以实现在UE访问业务X时为UE建立新的会话，进而UE可以通过V-PSA访问业务X，能够提升UE访问业务X的可靠性，以及降低访问业务X的时 延。
图13示出了本申请实施例中所涉及的一种通信装置的可能的示例性框图，该装置1300包括：收发模块1320和处理模块1310，收发模块1320可以包括接收单元和发送单元。处理模块1310用于对装置1300的动作进行控制管理。收发模块1320用于支持装置1300与其他网络实体的通信。可选地，装置1300还可以包括存储单元，所述存储单元用于存储装置1300的程序代码和数据。
可选地，所述装置1300中各个模块可以是通过软件来实现。
可选地，处理模块1310可以是处理器或控制器，例如可以是通用中央处理器(central processing unit，CPU)，通用处理器，数字信号处理(digital signal processing，DSP)，专用集成电路(application specific integrated circuits，ASIC)，现场可编程门阵列(field programmable gate array，FPGA)或者其他可编程逻辑器件、晶体管逻辑器件、硬件部件或者其任意组合。其可以实现或执行结合本申请实施例公开内容所描述的各种示例性的逻辑方框，模块和电路。所述处理器也可以是实现计算功能的组合，例如包含一个或多个微处理器组合，DSP和微处理器的组合等等。收发模块1320可以是通信接口、收发器或收发电路等，其中，该通信接口是统称，在具体实现中，该通信接口可以包括多个接口，存储单元可以是存储器。
当装置1300为归属地会话管理网元或归属地会话管理网元中的芯片时，装置1300中的处理模块1310可以支持装置1300执行上文中各方法示例中归属地会话管理网元的动作，例如可以支持装置1300执行图6中的步骤610或图8中的步骤810。
收发模块1320可以支持装置1300与拜访地会话管理网元进行通信，例如，收发模块1320可以支持装置1300执行图6中的步骤600、步骤620或图8中的步骤800、步骤820。
一种可能的实现方式：
收发模块1320，用于接收第一会话建立请求消息，所述第一会话建立请求消息用于请求建立终端设备的会话；处理模块1310，用于确定拜访地会话管理网元；收发模块1320，用于从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息。
其中，拜访地锚点用户面网元的信息可以为拜访地锚点用户面网元的标识和/或地址。
在一种可能的设计中，处理模块1310，用于在确定拜访地会话管理网元时，根据所述终端设备的位置确定第一拜访地公共陆地移动网络，根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息，所述拜访地会话管理网元部署于所述第一拜访地公共陆地移动网络。
在一种可能的设计中，处理模块1310，用于获取第一业务与所述第一拜访地公共陆地移动网络的对应关系；所述第一拜访地公共陆地移动网络不支持归属地用户面网元接入所述第一业务；在根据所述终端设备的位置确定第一拜访地公共陆地移动网络时，根据所述对应关系和所述终端设备的位置确定所述第一拜访地公共陆地移动网络。
在一种可能的设计中，处理模块1310，用于还获得第一指示信息，所述第一指示信息用于指示所述第一业务通过第一拜访地公共陆地移动网络的锚点用户面网元接入。
在一种可能的设计中，收发模块1320，用于在根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息时，向网络存储功能网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网 络的标识用于确定所述拜访地会话管理网元；从所述网络存储功能网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
在一种可能的设计中，收发模块1320，用于在根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息时，向归属地接入和移动性管理网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；从所述归属地接入和移动性管理网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
在一种可能的设计中，所述请求消息还包括拜访地用户面网元的信息，所述第一拜访地公共陆地移动网络支持所述拜访地用户面网元接入所述第一业务，所述拜访地用户面网元的信息用于确定所述拜访地会话管理网元。
在一种可能的设计中，收发模块1320，用于向所述拜访地会话管理网元发送第二指示信息，所述第二指示信息指示所述拜访地会话管理网元选择所述拜访地锚点用户面网元，不选择拜访地分流点。
在一种可能的设计中，收发模块1320，用于向所述拜访地会话管理网元发送所述终端设备的位置信息，所述终端设备的位置信息用于选择所述拜访地锚点用户面网元。
在一种可能的设计中，收发模块1320，用于向所述拜访地会话管理网元发送所述第一业务的标识，所述第一业务的标识用于选择支持接入所述第一业务的拜访地锚点用户面网元。
在一种可能的设计中，收发模块1320，用于向归属地分流点发送分流规则，所述分流规则指示将所述第一拜访地公共陆地移动网络对应的地址范围的报文分流至所述拜访地锚点用户面网元。
一种可能的实现方式：
收发模块1320，用于接收终端设备请求接入的第一业务的标识；处理模块1310，用于根据所述第一业务的标识，以及所述第一业务与第一拜访地公共陆地移动网络的对应关系确定拜访地会话管理网元，所述拜访地会话管理网元部署于所述第一拜访地公共陆地移动网络，所述第一拜访地公共陆地移动网络不支持归属地用户面网元接入所述第一业务；收发模块1320，用于从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息。
在一种可能的设计中，处理模块1310，用于在根据所述第一业务的标识，以及所述第一业务与第一拜访地公共陆地移动网络的对应关系确定拜访地会话管理网元，根据所述第一业务的标识，以及所述第一业务与所述第一拜访地公共陆地移动网络的对应关系确定所述第一拜访地公共陆地移动网络；根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息。
在一种可能的设计中，收发模块1320，用于在根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息时，向网络存储功能网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；从所述网络存储功能网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
在一种可能的设计中，收发模块1320，用于在根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息时，向归属地接入和移动性管理网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共 陆地移动网络的标识用于确定所述拜访地会话管理网元；从所述归属地接入和移动性管理网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
在一种可能的设计中，所述请求消息还包括拜访地用户面网元的信息，所述第一拜访地公共陆地移动网络支持所述拜访地用户面网元接入所述第一业务，所述拜访地用户面网元的信息用于确定所述拜访地会话管理网元。
在一种可能的设计中，处理模块1310，用于获取边缘应用服务器的地址；
收发模块1320，用于向所述拜访地会话管理网元发送所述边缘应用服务器的地址，所述边缘应用服务器的地址用于选择所述拜访地锚点用户面网元。
在一种可能的设计中，收发模块1320，用于向所述拜访地会话管理网元发送指示信息，所述指示信息指示所述拜访地会话管理网元选择所述拜访地锚点用户面网元，不选择拜访地分流点。
在一种可能的设计中，收发模块1320，用于向所述拜访地会话管理网元发送所述终端设备的位置信息，所述终端设备的位置信息用于选择所述拜访地锚点用户面网元。
在一种可能的设计中，收发模块1320，用于向所述拜访地会话管理网元发送所述第一业务的标识，所述第一业务的标识用于选择支持接入所述第一业务的拜访地锚点用户面网元。
在一种可能的设计中，收发模块1320，用于在确定拜访地会话管理网元之后，在从获得拜访地锚点用户面网元的信息之前，所述归属地接入和移动性管理网元发送所述拜访地会话管理网元的信息，所述拜访地会话管理网元的信息用于建立所述终端设备的会话。
在一种可能的设计中，收发模块1320，用于在确定拜访地会话管理网元之后，在从获得拜访地锚点用户面网元的信息之前，向所述归属地接入和移动性管理网元发送会话修改指令，所述会话修改指令用于指示建立第一会话；从所述归属地接入和移动性管理网元接收用于创建所述第一会话的会话管理上下文消息，所述用于创建所述第一会话的会话管理上下文消息包括所述第二会话的标识，所述第二会话为所述终端设备之前与所述归属地会话管理网元建立的会话；所述处理模块1310，用于根据所述第二会话的标识，以及所述第二会话的标识和所述拜访地会话管理网元的信息的对应关系确定所述拜访地会话管理网元的信息。其中，所述第二会话的标识和所述拜访地会话管理网元的标识的对应关系保存于所述第二会话的上下文。
应理解，根据本申请实施例的装置1300可对应于前述方法实施例中归属地会话管理网元，并且装置1300中的各个模块的操作和/或功能分别为了实现前述方法实施例中归属地会话管理网元的方法的相应步骤，因此也可以实现前述方法实施例中的有益效果，为了简洁，这里不作赘述。此外，根据本申请实施例的装置1300可对应于前述方法实施例中终端设备、归属地接入和移动性管理网元、网络存储功能网元、归属地分流点、拜访地锚点用户网元等，并且装置1300中的各个模块的操作和/或功能分别为了实现前述方法实施例中相应设备的步骤。
当装置1300为拜访地会话管理网元或拜访地会话管理网元中的芯片时，装置1300中的处理模块1310可以支持装置1300执行上文中各方法示例中拜访地会话管理网元的动作。
收发模块1320可以支持装置1300与归属地会话管理网元进行通信，例如，收发模块1320可以支持装置1300执行图6中的步骤620，图8中的步骤820。
收发模块1320，用于从归属地会话管理网元接收第一消息，所述第一消息用于请求或 修改建立终端设备的会话；处理模块1310，用于为所述会话选择拜访地锚点用户面网元；收发模块1320，用于向所述归属地会话管理网元发送所述拜访地锚点用户面网元的信息。
在一种可能的设计中，处理模块1310，用于选择所述拜访地锚点用户面网元，不选择拜访地分流点。
在一种可能的设计中，收发模块1320，用于从所述归属地会话管理网元接收指示信息，所述指示信息指示所述拜访地会话管理网元选择拜访地锚点用户面网元，不选择拜访地分流点。
在一种可能的设计中，收发模块1320，用于从所述归属地会话管理网元接收第一业务的标识；处理模块1310，用于在为所述会话选择拜访地锚点用户面网元时根据所述第一业务的标识选择所述拜访地锚点用户面网元，其中，所述拜访地锚点用户面网元为支持接入所述第一业务的拜访地锚点用户面网元。
在一种可能的设计中，收发模块1320，用于从所述归属地会话管理网元接收所述边缘应用服务器的地址；
处理模块1310，用于在为所述会话选择拜访地锚点用户面网元时根据所述边缘应用服务器的地址选择所述拜访地锚点用户面网元，其中，所述拜访地锚点用户面网元为支持接入所述边缘应用服务器的拜访地锚点用户面网元。
在一种可能的设计中，收发模块1320，用于从所述归属地会话管理网元接收所述终端设备的位置信息；处理模块1310，用于在为所述会话选择拜访地锚点用户面网元时根据所述终端设备的位置信息选择所述拜访地锚点用户面网元。
应理解，根据本申请实施例的装置1300可对应于前述方法实施例中拜访地会话管理网元，并且装置1300中的各个模块的操作和/或功能分别为了实现前述方法实施例中拜访地会话管理网元的方法的相应步骤，因此也可以实现前述方法实施例中的有益效果，为了简洁，这里不作赘述。此外，根据本申请实施例的装置1300可对应于前述方法实施例中终端设备、归属地接入和移动性管理网元、网络存储功能网元、归属地分流点、拜访地锚点用户网元等，并且装置1300中的各个模块的操作和/或功能分别为了实现前述方法实施例中相应设备的步骤。
图14示出了根据本申请实施例的通信装置1400的示意性结构图。如图14所示，所述装置1400包括：处理器1401。
当装置1400为归属地会话管理网元或归属地会话管理网元中的芯片时，一种可能的实现方式中，当所述处理器1401用于调用接口执行以下动作：
一种可能的实现方式：
接收第一会话建立请求消息，所述第一会话建立请求消息用于请求建立终端设备的会话；确定拜访地会话管理网元；从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息。
一种可能的实现方式：
接收终端设备请求接入的第一业务的标识；根据所述第一业务的标识，以及所述第一业务与第一拜访地公共陆地移动网络的对应关系确定拜访地会话管理网元，所述拜访地会话管理网元部署于所述第一拜访地公共陆地移动网络，所述第一拜访地公共陆地移动网络不支持归属地用户面网元接入所述第一业务；从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息。
应理解，所述装置1400还可用于执行前文实施例中归属地会话管理网元侧的其他步骤和/或操作，为了简洁，这里不作赘述。此外，所述装置1400还可用于执行前文实施例中前述方法实施例中终端设备、归属地接入和移动性管理网元、网络存储功能网元、归属地分流点、拜访地锚点用户网元的相应步骤和/或操作。
当装置1400为拜访地会话管理网元或拜访地会话管理网元中的芯片时，一种可能的实现方式中，当所述处理器1401用于调用接口执行以下动作：
从归属地会话管理网元接收第一消息，所述第一消息用于请求或修改建立终端设备的会话；为所述会话选择拜访地锚点用户面网元；向所述归属地会话管理网元发送所述拜访地锚点用户面网元的信息。
应理解，所述装置1400还可用于执行前文实施例中拜访地会话管理网元侧的其他步骤和/或操作，为了简洁，这里不作赘述。此外，所述装置1400还可用于执行前文实施例中前述方法实施例中终端设备、归属地接入和移动性管理网元、网络存储功能网元、归属地分流点、拜访地锚点用户网元的相应步骤和/或操作。
应理解，所述处理器1401可以调用接口执行上述收发动作，其中，调用的接口可以是逻辑接口或物理接口，对此不作限定。可选地，物理接口可以通过收发器实现。可选地，所述装置1400还包括收发器1403。
可选地，所述装置1400还包括存储器1402，存储器1402中可以存储上述方法实施例中的程序代码，以便于处理器1401调用。
具体地，若所述装置1400包括处理器1401、存储器1402和收发器1403，则处理器1401、存储器1402和收发器1403之间通过内部连接通路互相通信，传递控制和/或数据信号。在一个可能的设计中，处理器1401、存储器1402和收发器1403可以通过芯片实现，处理器1401、存储器1402和收发器1403可以是在同一个芯片中实现，也可能分别在不同的芯片实现，或者其中任意两个功能组合在一个芯片中实现。该存储器1402可以存储程序代码，处理器1401调用存储器1402存储的程序代码，以实现装置1400的相应功能。
上述本申请实施例揭示的方法可以应用于处理器中，或者由处理器实现。处理器可能是一种集成电路芯片，具有信号的处理能力。在实现过程中，上述方法实施例的各步骤可以通过处理器中的硬件的集成逻辑电路或者软件形式的指令完成。上述的处理器可以是通用处理器、数字信号处理器(digital signal processor，DSP)、专用集成电路(application specific integrated circuit，ASIC)、现成可编程门阵列(field programmable gate array，FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件，还可以是系统芯片(system on chip，SoC)，还可以是中央处理器(central processor unit，CPU)，还可以是网络处理器(network processor，NP)，还可以是数字信号处理电路(digital signal processor，DSP)，还可以是微控制器(micro controller unit，MCU)，还可以是可编程控制器(programmable logic device，PLD)或其他集成芯片。可以实现或者执行本申请实施例中的公开的各方法、步骤及逻辑框图。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件译码处理器执行完成，或者用译码处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器，处理器读取存储器中的信息，结合其硬件完成上述方法的步骤。
可以理解，本申请实施例中的存储器可以是易失性存储器或非易失性存储器，或可包括易失性和非易失性存储器两者。其中，非易失性存储器可以是只读存储器(read-only memory，ROM)、可编程只读存储器(programmable ROM，PROM)、可擦除可编程只读存储器(erasable PROM，EPROM)、电可擦除可编程只读存储器(electrically EPROM，EEPROM)或闪存。易失性存储器可以是随机存取存储器(random access memory，RAM)，其用作外部高速缓存。通过示例性但不是限制性说明，许多形式的RAM可用，例如静态随机存取存储器(static RAM，SRAM)、动态随机存取存储器(dynamic RAM，DRAM)、同步动态随机存取存储器(synchronous DRAM，SDRAM)、双倍数据速率同步动态随机存取存储器(double data rate SDRAM，DDR SDRAM)、增强型同步动态随机存取存储器(enhanced SDRAM，ESDRAM)、同步连接动态随机存取存储器(synchlink DRAM，SLDRAM)和直接内存总线随机存取存储器(direct rambus RAM，DR RAM)。应注意，本文描述的系统和方法的存储器旨在包括但不限于这些和任意其它适合类型的存储器。
本申请还提供一种通信系统，所述系统包括归属地会话管理网元、归属地接入和移动性管理网元、终端设备、归属地分流点、拜访地会话管理网元、网络存储功能网元、拜访地锚点用户面网元中的一种或多种，其中，所述终端设备用于执行前文实施例中终端设备侧的步骤和/或操作，所述归属地会话管理网元用于执行前文实施例中归属地会话管理网元侧的步骤和/或操作，所述归属地接入和移动性管理网元用于执行前文实施例中归属地接入和移动性管理网元侧的步骤和/或操作。
应理解，在本申请实施例中，编号“第一”、“第二”…仅仅为了区分不同的对象，比如为了区分不同的参数信息或者消息，并不对本申请实施例的范围构成限制，本申请实施例并不限于此。
还应理解，在本申请的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定。上述各个过程涉及的各种数字编号或序号仅为描述方便进行的区分，而不应对本申请实施例的实施过程构成任何限定。
还应理解，本文中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本文中字符“/”，一般表示前后关联对象是一种“或”的关系。
本申请中出现的类似于“项目包括如下中的一项或多项：A，B，以及C”表述的含义，如无特别说明，通常是指该项目可以为如下中任一个：A；B；C；A和B；A和C；B和C；A，B和C；A和A；A，A和A；A，A和B；A，A和C，A，B和B；A，C和C；B和B，B，B和B，B，B和C，C和C；C，C和C，以及其他A，B和C的组合。以上是以A，B和C共3个元素进行举例来说明该项目的可选用条目，当表达为“项目包括如下中至少一种：A，B，……，以及X”时，即表达中具有更多元素时，那么该项目可以适用的条目也可以按照前述规则获得。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
所述功能如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器ROM、随机存取存储器RAM、磁碟或者光盘等各种可以存储程序代码的介质。

Claims (42)

  1. 一种通信方法，其特征在于，该方法包括：
    归属地会话管理网元接收第一会话建立请求消息，所述第一会话建立请求消息用于请求建立终端设备的会话；
    所述归属地会话管理网元确定拜访地会话管理网元；
    所述归属地会话管理网元从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息。
  2. 如权利要求1所述的方法，其特征在于，所述归属地会话管理网元确定拜访地会话管理网元，包括：
    所述归属地会话管理网元根据所述终端设备的位置确定第一拜访地公共陆地移动网络；
    所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息，所述拜访地会话管理网元部署于所述第一拜访地公共陆地移动网络。
  3. 如权利要求2所述的方法，其特征在于，还包括：
    所述归属地会话管理网元获取第一业务与所述第一拜访地公共陆地移动网络的对应关系；所述第一拜访地公共陆地移动网络不支持归属地用户面网元接入所述第一业务；
    所述归属地会话管理网元根据所述终端设备的位置确定第一拜访地公共陆地移动网络，包括：
    所述归属地会话管理网元根据所述对应关系和所述终端设备的位置确定所述第一拜访地公共陆地移动网络。
  4. 如权利要求3所述的方法，其特征在于，还包括：
    所述归属地会话管理网元还获得第一指示信息，所述第一指示信息用于指示所述第一业务通过第一拜访地公共陆地移动网络的锚点用户面网元接入。
  5. 如权利要求2-4任一项所述的方法，其特征在于，所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息，包括：
    所述归属地会话管理网元向网络存储功能网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；
    所述归属地会话管理网元从所述网络存储功能网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
  6. 如权利要求2-4任一项所述的方法，其特征在于，所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息，包括：
    所述归属地会话管理网元向归属地接入和移动性管理网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；
    所述归属地会话管理网元从所述归属地接入和移动性管理网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
  7. 如权利要求5或6所述的方法，其特征在于，所述请求消息还包括拜访地用户面网 元的信息，所述第一拜访地公共陆地移动网络支持所述拜访地用户面网元接入所述第一业务，
    所述拜访地用户面网元的信息用于确定所述拜访地会话管理网元。
  8. 如权利要求1-7任一项所述的方法，其特征在于，还包括：
    所述归属地会话管理网元还向所述拜访地会话管理网元发送第二指示信息，所述第二指示信息指示所述拜访地会话管理网元选择所述拜访地锚点用户面网元，不选择拜访地分流点。
  9. 如权利要求1-8任一项所述的方法，其特征在于，还包括：
    所述归属地会话管理网元还向所述拜访地会话管理网元发送所述终端设备的位置信息，所述终端设备的位置信息用于选择所述拜访地锚点用户面网元。
  10. 如权利要求1-9任一项所述的方法，其特征在于，还包括：
    所述归属地会话管理网元还向所述拜访地会话管理网元发送所述第一业务的标识，所述第一业务的标识用于选择支持接入所述第一业务的拜访地锚点用户面网元。
  11. 如权利要求1-10任一项所述的方法，其特征在于，还包括：
    所述归属地会话管理网元向归属地分流点发送分流规则，所述分流规则指示将所述第一拜访地公共陆地移动网络对应的地址范围的报文分流至所述拜访地锚点用户面网元。
  12. 如权利要求1-11任一项所述的方法，其特征在于，所述拜访地锚点用户面网元的信息为所述拜访地锚点用户面网元的标识和/或地址。
  13. 如权利要求9所述的方法，其特征在于，还包括：
    所述归属地会话管理网元向所述拜访地会话管理网元发送所述终端设备在归属地公共陆地移动网络中的位置信息；
    所述拜访地会话管理网元获取映射关系；其中，所述映射关系指示在所述归属地公共陆地移动网络中位置信息与在所述第一拜访地公共陆地移动网络中的位置信息的映射关系；
    所述拜访地会话管理网元根据所述终端设备在归属地公共陆地移动网络中的位置信息，以及所述映射关系，确定所述终端设备在所述第一拜访地公共陆地移动网络中的位置信息。
  14. 如权利要求9所述的方法，其特征在于，还包括：
    所述归属地会话管理网元获取映射关系；其中，所述映射关系指示在归属地公共陆地移动网络中位置信息与在所述第一拜访地公共陆地移动网络中的位置信息的映射关系；
    所述归属地会话管理网元根据所述终端设备在所述归属地公共陆地移动网络中的位置信息，以及所述映射关系，确定所述终端设备在所述第一拜访地公共陆地移动网络中的位置信息；
    所述归属地会话管理网元向所述拜访地会话管理网元发送所述终端设备在所述第一拜访地公共陆地移动网络中的位置信息。
  15. 如权利要求9所述的方法，其特征在于，所述终端设备的位置信息为所述终端设备的地理位置信息。
  16. 一种通信方法，其特征在于，该方法包括：
    归属地会话管理网元接收终端设备请求接入的第一业务的标识；
    所述归属地会话管理网元根据所述第一业务的标识，以及所述第一业务与第一拜访地 公共陆地移动网络的对应关系确定拜访地会话管理网元，所述拜访地会话管理网元部署于所述第一拜访地公共陆地移动网络，所述第一拜访地公共陆地移动网络不支持归属地用户面网元接入所述第一业务；
    所述归属地会话管理网元从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息。
  17. 如权利要求16所述的方法，其特征在于，所述归属地会话管理网元根据所述第一业务的标识，以及所述第一业务与第一拜访地公共陆地移动网络的对应关系确定拜访地会话管理网元，包括：
    所述归属地会话管理网元根据所述第一业务的标识，以及所述第一业务与所述第一拜访地公共陆地移动网络的对应关系确定所述第一拜访地公共陆地移动网络；
    所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息。
  18. 如权利要求17所述的方法，其特征在于，所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息，包括：
    所述归属地会话管理网元向网络存储功能网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；
    所述归属地会话管理网元从所述网络存储功能网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
  19. 如权利要求17所述的方法，其特征在于，所述归属地会话管理网元根据所述第一拜访地公共陆地移动网络的标识获取所述拜访地会话管理网元的信息，包括：
    所述归属地会话管理网元向归属地接入和移动性管理网元发送请求消息，所述请求消息包括所述第一拜访地公共陆地移动网络的标识；所述第一拜访地公共陆地移动网络的标识用于确定所述拜访地会话管理网元；
    所述归属地会话管理网元从所述归属地接入和移动性管理网元接收响应消息，所述响应消息包括所述拜访地会话管理网元的信息。
  20. 如权利要求18或19所述的方法，其特征在于，所述请求消息还包括拜访地用户面网元的信息，所述第一拜访地公共陆地移动网络支持所述拜访地用户面网元接入所述第一业务，所述拜访地用户面网元的信息用于确定所述拜访地会话管理网元。
  21. 如权利要求16-20任一项所述的方法，其特征在于，还包括：
    所述归属地会话管理网元获取边缘应用服务器的地址；
    所述归属地会话管理网元向所述拜访地会话管理网元发送所述边缘应用服务器的地址，所述边缘应用服务器的地址用于选择所述拜访地锚点用户面网元。
  22. 如权利要求16-21任一项所述的方法，其特征在于，还包括：
    所述归属地会话管理网元还向所述拜访地会话管理网元发送指示信息，所述指示信息指示所述拜访地会话管理网元选择所述拜访地锚点用户面网元，不选择拜访地分流点。
  23. 如权利要求16-22任一项所述的方法，其特征在于，还包括：
    所述归属地会话管理网元还向所述拜访地会话管理网元发送所述终端设备的位置信息，所述终端设备的位置信息用于选择所述拜访地锚点用户面网元。
  24. 如权利要求16-23任一项所述的方法，其特征在于，还包括：
    所述归属地会话管理网元还向所述拜访地会话管理网元发送所述第一业务的标识，所述第一业务的标识用于选择支持接入所述第一业务的拜访地锚点用户面网元。
  25. 如权利要求16-20任一项所述的方法，其特征在于，在所述归属地会话管理网元确定拜访地会话管理网元之后，在从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息之前，还包括：
    所述归属地会话管理网元向所述归属地接入和移动性管理网元发送所述拜访地会话管理网元的信息，所述拜访地会话管理网元的信息用于建立所述终端设备的会话。
  26. 如权利要求16-20任一项所述的方法，其特征在于，在所述归属地会话管理网元确定拜访地会话管理网元之后，在从所述拜访地会话管理网元获得拜访地锚点用户面网元的信息之前，还包括：
    所述归属地会话管理网元向所述归属地接入和移动性管理网元发送会话修改指令，所述会话修改指令用于指示建立第一会话；
    所述归属地会话管理网元从所述归属地接入和移动性管理网元接收用于创建所述第一会话的会话管理上下文消息，所述用于创建所述第一会话的会话管理上下文消息包括所述第二会话的标识，所述第二会话为所述终端设备之前与所述归属地会话管理网元建立的会话；
    所述归属地会话管理网元根据所述第二会话的标识，以及所述第二会话的标识和所述拜访地会话管理网元的信息的对应关系确定所述拜访地会话管理网元的信息。
  27. 一种通信方法，其特征在于，该方法包括：
    拜访地会话管理网元从归属地会话管理网元接收第一消息，所述第一消息用于请求或修改建立终端设备的会话；
    所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元；
    所述拜访地会话管理网元向所述归属地会话管理网元发送所述拜访地锚点用户面网元的信息。
  28. 如权利要求27所述的方法，其特征在于，所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元，包括：
    所述拜访地会话管理网元选择所述拜访地锚点用户面网元，不选择拜访地分流点。
  29. 如权利要求27或28所述的方法，其特征在于，还包括：
    所述拜访地会话管理网元从所述归属地会话管理网元接收指示信息，所述指示信息指示所述拜访地会话管理网元选择拜访地锚点用户面网元，不选择拜访地分流点。
  30. 如权利要求27-29任一项所述的方法，其特征在于，还包括：
    所述拜访地会话管理网元从所述归属地会话管理网元接收第一业务的标识；
    所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元，包括：
    所述拜访地会话管理网元根据所述第一业务的标识选择所述拜访地锚点用户面网元，其中，所述拜访地锚点用户面网元为支持接入所述第一业务的拜访地锚点用户面网元。
  31. 如权利要求27-30任一项所述的方法，其特征在于，还包括：
    所述拜访地会话管理网元从所述归属地会话管理网元接收所述边缘应用服务器的地址；
    所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元，包括：
    所述拜访地会话管理网元根据所述边缘应用服务器的地址选择所述拜访地锚点用户 面网元，其中，所述拜访地锚点用户面网元为支持接入所述边缘应用服务器的拜访地锚点用户面网元。
  32. 如权利要求27-31任一项所述的方法，其特征在于，还包括：
    所述拜访地会话管理网元从所述归属地会话管理网元接收所述终端设备的位置信息；
    所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元，包括：
    所述拜访地会话管理网元根据所述终端设备的位置信息选择所述拜访地锚点用户面网元。
  33. 一种通信方法，其特征在于，该方法包括：
    归属地接入和移动性管理网元从终端设备接收会话建立请求消息，所述会话建立请求消息包括第二会话的标识，所述第二会话为所述终端设备之前与归属地会话管理网元建立的会话；
    所述归属地接入和移动性管理网元根据所述第二会话的标识确定所述归属地会话管理网元和拜访地会话管理网元。
  34. 如权利要求33所述的方法，其特征在于，所述归属地接入和移动性管理网元确定所述拜访地会话管理网元，包括：
    所述归属地接入和移动性管理网元从所述归属地会话管理网元接收所述拜访地会话管理网元的信息；或者，所述归属地接入和移动性管理网元从所述网络存储功能网元接收所述拜访地会话管理网元的信息。
  35. 一种通信装置，其特征在于，包括处理器，所述处理器与存储器耦合：
    所述处理器，用于执行所述存储器中存储的计算机指令，以使得所述通信装置执行如权利要求1至34任一项所述的方法。
  36. 一种计算机可读存储介质，其特征在于，所述存储介质中存储有计算机程序或指令，当所述计算机程序或指令被通信装置执行时，实现如权利要求1至34中任一项所述的方法。
  37. 一种计算机程序产品，其特征在于，所述计算机程序产品包括计算机程序，当所述计算机程序在装置上运行时，执行如权利要求1至34中任一项所述的方法。
  38. 一种通信方法，其特征在于，该方法包括：
    归属地会话管理网元接收第一会话建立请求消息，所述第一会话建立请求消息用于请求建立终端设备的会话；
    所述归属地会话管理网元确定拜访地会话管理网元；
    所述归属地会话管理网元向所述拜访地会话管理网元发送第一消息，所述第一消息用于请求建立所述终端设备的会话；
    所述拜访地会话管理网元为所述会话选择拜访地锚点用户面网元；
    所述拜访地会话管理网元向所述归属地会话管理网元发送所述拜访地锚点用户面网元的信息。
  39. 一种通信方法，其特征在于，该方法包括：
    归属地会话管理网元接收终端设备请求接入的第一业务的标识；
    所述归属地会话管理网元根据所述第一业务的标识，以及所述第一业务与第一拜访地公共陆地移动网络的对应关系确定拜访地会话管理网元，所述拜访地会话管理网元部署于所述第一拜访地公共陆地移动网络，所述第一拜访地公共陆地移动网络不支持归属地用户 面网元接入所述第一业务；
    所述归属地会话管理网元向所述拜访地会话管理网元发送所述第一业务的标识；
    所述拜访地会话管理网元根据所述第一业务的标识选择所述拜访地锚点用户面网元，其中，所述拜访地锚点用户面网元为支持接入所述第一业务的拜访地锚点用户面网元；
    所述拜访地会话管理网元向所述归属地会话管理网元发送所述拜访地锚点用户面网元的信息。
  40. 一种通信装置，其特征在于，包括收发模块和处理模块；
    所述收发模块，用于接收和发送数据；
    所述处理模块，用于通过所述收发模块，执行如权利要求1至34中任一项所述的方法。
  41. 一种芯片，其特征在于，所述芯片与存储器耦合，所述芯片读取所述存储器中存储的计算机程序，执行权利要求1至34任一项所述的方法。
  42. 一种通信系统，其特征在于，该系统包括：归属地会话管理网元和拜访地会话管理网元，其中，所述归属地会话管理网元执行如权利要求1至15任一项所述的方法或者执行如权利要求16至26任一项所述的方法，所述拜访地会话管理网元执行如权利要求27-32任一项所述的方法。
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CN110035562A (zh) * 2018-01-12 2019-07-19 华为技术有限公司 会话管理方法、设备及系统
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