METHOD FOR DETERMINING APPLICATION INSTANCE, APPARATUS, AND SYSTEM

TECHNICAL FIELD

The embodiments relate to the field of communication technologies, a method for determining an application instance, an apparatus, and a system.

BACKGROUND

Multi-access edge computing (MEC) provides a cloud computing-based capability for a mobile user at the edge of a carrier network close to the user, so that the user can deploy an application at the edge of the network by using the capability. After the cloud computing capability is deployed at the edge of the network, a telecom service that boasts high performance, a low latency, and high bandwidth can be provided, to accelerate delivery and downloading of content, services, and applications in the network, improving network experience of a consumer.

The European Telecommunications Standards Institute (ETSI) defines a reference architecture of MEC in its specification ETSI GS MEC 003. As shown in FIG. 1, the architecture mainly includes two parts: an MEC host and an MEC management system. The MEC host includes an MEC platform, virtualization infrastructure, and an MEC application. The virtualization infrastructure provides virtualized computing, storage, and network resources for the MEC application. The MEC application is deployed on the MEC host in a form of a virtual machine or a container. The MEC platform mainly includes service registration and discovery functions, and also includes some common services, such as a domain name system (DNS) server or a DNS proxy service. The MEC management system includes a multi-access edge orchestrator, an MEC platform manager, a virtualization infrastructure manager (VIM), and the like. The multi-access edge orchestrator maintains an overall view of an MEC system including all mobile edge hosts, available resources, and available MEC services, and triggers application instantiation and termination. The MEC platform manager is configured to manage the MEC platform, a life cycle of a mobile MEC application, and a flow rule and a DNS rule of the application. The VIM manages virtualization resources required by the MEC application. A user application life cycle management (LCM) proxy allows a device application to request the MEC system to instantiate and terminate the MEC application.

How to provide an optimal MEC application instance for a terminal is a problem to be resolved.

SUMMARY

The embodiments provide a method for determining an application instance, an apparatus, and a system, to determine an optimal MEC application instance for a terminal.

According to a first aspect, a method for determining an application instance is provided, including: A first network element obtains location information of a terminal. The first network element determines first at least one MEC application instance based on the location information of the terminal. The first network element sends address information of the first at least one MEC application instance to the terminal.

Based on the foregoing solution, when the terminal requests an MEC application instance, the first network element determines, based on a maintained correspondence between location information and an MEC application instance and the obtained location information of the terminal, an MEC application instance that has an optimal distance from the terminal. This reduces a latency of packet transmission between the MEC application instance and the terminal and improves quality of services.

In a possible implementation method, the first network element receives a first message sent by the terminal. The first message includes the location information of the terminal.

In a possible implementation method, the first network element receives a second message sent by a core network control plane function network element. The second message includes the location information of the terminal.

In a possible implementation method, the first network element stores address information of second at least one MEC application instance and location information of the second at least one MEC application instance. That the first network element determines first at least one MEC application instance based on the location information of the terminal includes: The first network element determines the first at least one MEC application instance from the second at least one MEC application instance based on the location information of the terminal and the location information of the second at least one MEC application instance.

According to a second aspect, a method for determining an application instance is provided, including: A control plane function network element sends first notification information to a first network element. The first notification information is used to notify the first network element that a user plane path of a terminal changes. The first network element obtains location information of the terminal. The first network element determines first at least one MEC application instance based on the location information of the terminal. The first network element sends address information of the first at least one MEC application instance to the terminal.

Based on the foregoing solution, when a UPF network element serving the terminal changes, a current MEC application instance may not be optimal. The first network element determines, based on the location information (a destination user plane location) of the terminal, an optimal application instance after the terminal switches to a new UPF network element. This reduces a latency of packet transmission between an MEC application instance and the terminal and improves quality of services.

In a possible implementation method, that the first network element obtains location information of the terminal includes: The first network element receives the first notification information. The first notification information includes the location information of the terminal, and the location information of the terminal is location information of a target user plane function (UPF) network element.

In a possible implementation method, the method further includes: The first network element receives an MEC application instance change subscription request message sent by the terminal.

According to a third aspect, a method for determining an application instance is provided, including: A first network element obtains information about first at least one EDN from a session management network element or a source EES. The first at least one EDN is determined based on location information of a terminal. The first network element determines first at least one MEC application instance in the first at least one EDN. The first network element sends address information of the first at least one MEC application instance to the terminal or the source EES. According to the method provided in the third aspect, when the terminal requests an MEC application instance, the first network element requests the information about the first at least one EDN from an SMF network element, to determine the first at least one MEC application instance. This reduces a latency of packet transmission between the MEC application instance and the terminal and improves quality of services.

In a possible implementation method, that a first network element obtains information about first at least one EDN from a session management network element or a source EES includes: The first network element sends a third message to the session management network element or the source EES. The third message is used to request at least one EDN that includes the MEC application instance requested by the terminal. The first network element receives the information about the first at least one EDN from the session management network element or the source EES.

In a possible implementation method, the third message includes information about a candidate EDN. The candidate EDN is determined by the first network element based on the location information of the terminal and information about an EDN stored in the first network element.

In a possible implementation method, the third message includes the location information of the terminal.

In a possible implementation method, the information about the first at least one EDN includes a data network application identifier (DNAI) of the first at least one EDN.

In a possible implementation method, the DNAI of the first at least one EDN includes a DNAI of an EES in the first at least one EDN and/or a DNAI of an MEC application instance in the first at least one EDN.

In a possible implementation method, the method further includes: The first network element sends to the terminal or the source EES, address information of an EES associated with the first at least one MEC application instance. The EES associated with the first at least one MEC application instance is included in the first at least one EDN.

In a possible implementation method, the information about the first at least one EDN is used to indicate communication performance of a communication path between the terminal and the first at least one EDN.

In a possible implementation method, the information about the first at least one EDN further includes at least one of the following information: a quantity of user plane network elements between the terminal and the first at least one EDN, an internal mobile network communication latency between the terminal and the first at least one EDN, an end-to-end communication latency between the terminal and the first at least one EDN, an internal mobile network communication bandwidth between the terminal and the first at least one EDN, and priority information of the communication path between the terminal and the first at least one EDN.

In a possible implementation method, the method further includes: The first network element sends priority information of the first at least one MEC application instance to the terminal or the source EES.

According to a fourth aspect, a method for determining an EES is provided, including: A first network element obtains information about first at least one EDN from a session management network element or a source EES. The first at least one EDN is determined based on location information of a terminal. The first network element determines first at least one EES in the first at least one EDN. The first network element sends address information of the first at least one EES to the terminal or the source EES. According to the method provided in the fourth aspect, when the terminal requests an EES, the first network element requests the information about the first at least one EDN from an SMF network element, to determine the first at least one EES. This reduces a latency of packet transmission between the terminal and an MEC application instance managed by the EES and improves quality of services.

In a possible implementation method, that a first network element obtains information about first at least one EDN from a session management network element or a source EES includes: The first network element sends a third message to the session management network element or the source EES. The third message is used to request at least one EDN that includes the EES requested by the terminal. The first network element receives the information about the first at least one EDN from the session management network element or the source EES.

In a possible implementation method, the third message includes the location information of the terminal.

In a possible implementation method, the information about the first at least one EDN includes a data network application identifier (DNAI) of the first at least one EDN.

In a possible implementation method, the DNAI of the first at least one EDN includes a DNAI of an EES in the first at least one EDN and/or a DNAI of a multi-access edge computing (MEC) application instance in the first at least one EDN.

In a possible implementation method, the method further includes: The first network element sends priority information of the first at least one EES to the terminal or the source EES.

According to a fifth aspect, a communication method is provided, including: A session management network element receives a third message from a first network element. The third message is used to request at least one EDN that includes an MEC application instance requested by a terminal or an EES requested by the terminal. The session management network element sends information about first at least one EDN to the first network element based on the third message. When the at least one EDN includes the MEC application instance requested by the terminal, the first at least one EDN includes an EDN that includes the MEC application instance requested by the terminal. When the at least one EDN includes the EES requested by the terminal, the first at least one EDN includes an EDN that includes the EES requested by the terminal. According to the communication method provided in the fifth aspect, when the terminal requests the MEC application instance, the first network element requests the information about the first at least one EDN from an SMF network element, to determine first at least one MEC application instance. This reduces a latency of packet transmission between the MEC application instance and the terminal and improves quality of services. When the terminal requests the EES, the first network element requests the information about the first at least one EDN from the SMF network element, to determine the first at least one EES. This reduces a latency of packet transmission between the terminal and an MEC application instance managed by the EES and improves quality of services.

In a possible implementation method, the first at least one EDN is determined based on location information of the terminal and information about second at least one EDN obtained by the session management network element.

In a possible implementation method, the first at least one EDN is determined based on the location information of the terminal and information about a candidate EDN, and the information about the candidate EDN is carried in the third message.

In a possible implementation method, the location information of the terminal is carried in the third message.

In a possible implementation method, the information about the first at least one EDN includes a data network application identifier (DNAI) of the first at least one EDN.

In a possible implementation method, the DNAI of the first at least one EDN includes a DNAI of the EES in the first at least one EDN and/or a DNAI of the MEC application instance in the first at least one EDN.

According to a sixth aspect, a signal sending method is provided, including: A terminal sends a first message. The first message includes location information of the terminal. Alternatively, the terminal sends an MEC application instance change subscription request.

According to a seventh aspect, a method for determining an EES is provided, including: A first network element obtains information about first at least one EDN from a second network element. The first at least one EDN is determined based on at least one of location information of a terminal or service information of the terminal, and the second network element is a first session management network element, an NEF network element, or a source EES. The first network element determines first at least one EES based on the information about the first at least one EDN. The first network element sends address information of the first at least one EES to the terminal or the source EES.

In a possible implementation method, that a first network element obtains information about first at least one EDN from a second network element includes: The first network element sends a third message to the second network element. The third message includes at least one of information used to determine a location of the terminal or the service information of the terminal. The first network element receives the information about the first at least one EDN from the second network element. The first at least one EDN matches at least one of the location information of the terminal or the service information of the terminal.

In a possible implementation method, the information about the first at least one EDN includes at least one DNAI of the first at least one EDN.

In a possible implementation method, the method further includes: The first network element sends priority information of the first at least one EES to the terminal or the source EES.

According to an eighth aspect, a communication method is provided, including: A second network element receives a third message from a first network element. The third message includes at least one of information used to determine a location of a terminal or service information of the terminal, and the second network element is a first session management network element, an NEF network element, or a source EES. The second network element sends information about first at least one EDN to the first network element based on the third message. The first at least one EDN matches at least one of location information of the terminal or the service information of the terminal.

In a possible implementation method, that the second network element sends information about first at least one EDN to the first network element based on the third message includes: The second network element determines a second session management network element based on the location information of the terminal. The second network element sends a request message to the second session management network element. The request message includes at least one of location information or service information, the location information includes the location information of the terminal, and the service information includes the service information of the terminal. The second network element receives the information about the first at least one EDN from the second session management network element. The second network element sends the information about the first at least one EDN to the first network element.

In a possible implementation method, the second network element is the NEF network element, and that the second network element sends information about first at least one EDN to the first network element based on the third message includes: The second network element determines the information about the first at least one EDN based on the location information of the terminal and a first correspondence. The first correspondence includes a correspondence between location area information and information about an EDN. Alternatively, the second network element determines the information about the first at least one EDN based on the service information of the terminal and a second correspondence. The second correspondence includes a correspondence between service information and information about an EDN. Alternatively, the second network element determines the information about the first at least one EDN based on the location information of the terminal, the service information of the terminal, and a third correspondence. The third correspondence includes a correspondence among location area information, information about an EDN, and service information. The second network element sends the information about the first at least one EDN to the first network element.

In a possible implementation method, the information about the first at least one EDN includes at least one DNAI of the first at least one EDN.

According to a ninth aspect, a communication method is provided, including: A second session management network element receives a request message from a second network element. The request message includes at least one of location information and service information, the location information includes location information of a terminal, the service information includes service information of the terminal, and the second network element is a first session management network element, an NEF network element, or a source EES. When the request message includes the location information, the second session management network element determines information about first at least one EDN based on the location information and a first correspondence. The first correspondence includes a correspondence between location area information and information about an EDN. Alternatively, when the request message includes the service information, the second session management network element determines information about first at least one EDN based on the service information and a second correspondence. The second correspondence includes a correspondence between the service information and information about an EDN. Alternatively, when the request message includes the location information and the service information, the second session management network element determines information about first at least one EDN based on the location information, the service information, and a third correspondence. The third correspondence includes a correspondence among location area information, information about an EDN, and the service information. The second session management network element sends the information about the first at least one EDN to the second network element.

According to a tenth aspect, a communication apparatus is provided, including a function unit configured to perform any method provided in any one of the first aspect to the ninth aspect. An action performed by the function unit is implemented by hardware or implemented by hardware executing corresponding software.

According to an eleventh aspect, a communication apparatus is provided, including a processor and a memory. The memory is configured to store computer-executable instructions. When the apparatus runs, the processor executes the computer-executable instructions stored in the memory, so that the apparatus performs any method provided in any one of the first aspect to the ninth aspect.

According to a twelfth aspect, a terminal apparatus is provided. The terminal apparatus is configured to send a first message, where the first message includes location information; or the terminal apparatus is configured to send an MEC application instance change subscription request.

According to a thirteenth aspect, a communication apparatus is provided, including units or means configured to perform the steps in any method provided in any one of the first aspect to the ninth aspect.

According to a fourteenth aspect, a communication apparatus is provided, including a processor and an interface circuit. The processor is configured to: communicate with another apparatus through the interface circuit, and perform any method provided in any one of the first aspect to the ninth aspect. There are one or more processors.

According to a fifteenth aspect, a communication apparatus is provided, including a processor, configured to: connect to a memory, and invoke a program stored in the memory, to perform any method provided in any one of the first aspect to the ninth aspect. The memory may be located inside or outside the apparatus. In addition, there are one or more processors.

According to a sixteenth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores instructions. When the instructions are run on a computer, a processor is enabled to perform any method provided in any one of the first aspect to the ninth aspect.

According to a seventeenth aspect, a computer program product including instructions is provided. When the computer program product runs on a computer, the computer is enabled to perform any method provided in any one of the first aspect to the ninth aspect.

According to an eighteenth aspect, a chip system is provided, including a processor, configured to perform any method provided in any one of the first aspect to the ninth aspect.

According to a nineteenth aspect, a communication system is provided, including a control plane function network element and a first network element. The control plane function network element is configured to send first notification information to the first network element. The first notification information is used to notify the first network element that a user plane path of a terminal changes. The first network element is configured to: obtain location information of the terminal and determine first at least one MEC application instance based on the location information of the terminal. The first network element is further configured to send address information of the first at least one MEC application instance to the terminal.

According to a twentieth aspect, a communication system is provided, including any one or more network elements in the first aspect to the ninth aspect.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of an architecture of an MEC system;

FIG. 2 is a schematic diagram of a 5G network architecture based on a service-oriented architecture;

FIG. 3 is a schematic diagram of an architecture of an MEC system;

FIG. 3A is a schematic diagram of an architecture of another MEC system;

FIG. 3B is a schematic diagram of an architecture of still another MEC system;

FIG. 3C is a schematic diagram of an architecture of yet another MEC system;

FIG. 4 is a schematic diagram of a relationship between a location of a terminal and a location of an MEC application instance;

FIG. 5 is a schematic flowchart of a method for determining an application instance according to an embodiment;

FIG. 6 is a schematic flowchart of another method for determining an application instance according to an embodiment;

FIG. 6A is a schematic flowchart of still another method for determining an application instance according to an embodiment;

FIG. 6B is a schematic flowchart of a method for determining an EES according to an embodiment;

FIG. 6C is a schematic diagram of locations of an EES and an EDN CS according to an embodiment;

FIG. 6D is a schematic flowchart of a method for determining an EES according to an embodiment;

FIG. 6E is a schematic flowchart of a method for obtaining information about an EDN according to an embodiment;

FIG. 6F is a schematic flowchart of another method for obtaining information about an EDN according to an embodiment;

FIG. 6G is a schematic diagram of a correspondence between a DNAI and an EDN according to an embodiment;

FIG. 6H-1 and FIG. 6H-2 are a flowchart of a method for determining an EES that provides a service for a terminal according to an embodiment;

FIG. 6I-1 and FIG. 6I-2 are a flowchart of a method for determining an MEC application instance that provides a service for a terminal according to an embodiment;

FIG. 7 is a schematic diagram of a communication apparatus according to an embodiment;

FIG. 8 is a schematic diagram of another communication apparatus according to an embodiment;

FIG. 8A is a schematic diagram of still another communication apparatus according to an embodiment;

FIG. 8B is a schematic diagram of yet another communication apparatus according to an embodiment; and

FIG. 9 is a schematic diagram of still yet another communication apparatus according to an embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

To make objectives, solutions, and advantages of the embodiments clearer, the following further describes the embodiments in detail with reference to accompanying drawings. An operation in a method embodiment may also be applied to an apparatus embodiment or a system embodiment. In descriptions of the embodiments, “a plurality of” means two or more than two unless otherwise specified.

FIG. 2 is a schematic diagram of a 5th generation (5G) network architecture based on a service-oriented architecture. The 5G network architecture shown in FIG. 2 may include three parts: a terminal (namely, UE in FIG. 2), a data network (DN), and a carrier network. The following briefly describes functions of some network elements.

The carrier network may include one or more of the following network elements: an authentication server function (AUSF) network element, a network exposure function (NEF) network element, a policy control function (PCF) network element, a unified data management (UDM) network element, a unified data repository (UDR), a network repository function (NRF) network element, an application function (AF) network element, an access and mobility management function (AMF) network element, a session management function (SMF) network element, a radio access network (RAN) network element, a user plane function (UPF) network element, and the like. In the foregoing carrier network, parts other than the radio access network may be referred to as core network parts.

The terminal is a device having a wireless transceiver function, may be deployed on land, and includes an indoor device, an outdoor device, a hand-held device, or a vehicle-mounted device. The terminal may also be deployed on water (for example, on a ship), and may also be deployed in air (for example, in an aircraft, a balloon, or a satellite). Alternatively, the terminal may be referred to as user equipment (UE), a terminal device, an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user apparatus. The terminal may be a mobile phone, a tablet (pad), a computer having the wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, or the like.

The terminal may establish a connection to the carrier network through an interface (for example, N1) provided by the carrier network, and use services such as a data service and/or a voice service provided by the carrier network. The terminal may further access the DN through the carrier network and use a carrier service deployed on the DN and/or a service provided by a third party. The third party may be a service provider other than the carrier network and the terminal and may provide another service such as a data service and/or a voice service for the terminal device. A representation form of the third party may be determined based on an actual application scenario and is not limited herein.

The RAN is a sub-network of the carrier network and is an implementation system between a service node in the carrier network and the terminal. To access the carrier network, the terminal first passes through the RAN, and may be connected to the service node in the carrier network through the RAN. A RAN device is a device that provides a wireless communication function for the terminal, and the RAN device is also referred to as an access network device. The RAN device includes but is not limited to: a next generation NodeB (gNB), an evolved NodeB (eNB), a radio network controller (RNC), a NodeB (NB), a base station controller (BSC), a base transceiver station (BTS), a home evolved NodeB (HNB), a baseband unit (BBU), a transmitting and receiving point (TRP), a transmitting point (TP), a mobile switching center, and the like in 5G.

The AMF network element is responsible for mobility management of a user, including mobility status management, temporary user identity allocation, user authentication and authorization, and the like.

The SMF network element has functions such as session management, execution of a control policy delivered by a PCF network element, selection of a UPF network element, terminal internet protocol (IP) address allocation, bearer setup, modification, and release, and quality of service (QoS) control.

The UPF network element supports functions such as interconnection between a protocol data unit (PDU) session and the data network, packet routing and forwarding, and data packet detection.

The UDM network element is responsible for functions such as subscription data management and user access authorization.

The UDR stores and retrieves subscription data, policy data, and common architecture data, so that the UDM, PCF network element, and NEF network element can obtain related data. The UDR can provide different data access authentication mechanisms for different types of data, such as the subscription data and the policy data, to ensure data access security. The UDR needs to return a failure response with an appropriate cause value for an invalid service operation or data access request.

The NEF network element supports a network capability exposure function and exposes network capabilities and services to external systems. A 3rd generation partnership project (3GPP) network function (NF) network element publishes a function and an event to another NF network element through the NEF network element. A capability and an event exposed by the NF network element can be securely exposed to a third-party application. The NEF network element uses a standardized interface (Nudr) of a unified data repository (UDR) to store/retrieve structured data and translates exchange information of an AF network element and exchange information of an internal network function.

The AF network element is configured to provide an application layer service for the terminal. When providing the service for the terminal, the AF network element has a requirement on a QoS policy and a charging policy and needs to notify a network. In addition, the AF network element also requires application-related information fed back by the core network.

The PCF network element is responsible for policy control functions such as session-level or service flow-level charging, QoS bandwidth guarantee and mobility management, and terminal policy decision. In this architecture, PCF network elements connected to the AMF network element and the SMF network element are separately an Access and Mobility (AM) PCF network element and a Session Management (SM) PCF network element. In an actual deployment scenario, the PCF network elements may not be a same PCF entity.

The NRF network element may be configured to provide a network element discovery function and provide network element information corresponding to a network element type based on a request from another network element. The NRF network element further provides a network element management service, for example, registration, update, and deregistration of a network element and subscription and push of a network element status.

The AUSF network element is responsible for authenticating the user, to determine whether to allow the user or the device to access the network.

The DN is a network outside the carrier network. The carrier network may access a plurality of DNs. A plurality of services may be deployed on the DN, and the DN may provide services such as a data service and/or a voice service for the terminal. For example, the DN is a private network of a smart factory, a sensor installed in a workshop of the smart factory may be the terminal, a control server of the sensor is deployed in the DN, and the control server may provide a service for the sensor. The sensor may communicate with the control server, to obtain instructions of the control server, transmit collected sensor data to the control server according to the instructions, and the like. For another example, the DN is an internal office network of a company, a mobile phone or a computer of an employee of the company may be the terminal, and the mobile phone or the computer of the employee may access information, data resources, and the like on the internal office network of the company.

In FIG. 2, Nausf, Nnef, Npcf, Nudm, Naf, Namf, Nsmf, N1, N2, N3, N4, and N6 are interface serial numbers. For meanings of these interface serial numbers, refer to definitions in 3GPP specifications. No limitation is imposed herein.

It may be understood that the network elements or the functions may be network elements in a hardware device, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (for example, a cloud platform). Optionally, the foregoing network elements or functions may be implemented by one device or may be jointly implemented by a plurality of devices or may be one function module in one device. This is not limited in the embodiments.

A mobility management network element, a session management network element, a policy control network element, an application function network element, an access network device, a network exposure function network element, and a user plane network element in embodiments may be respectively an AMF network element, an SMF network element, a PCF network element, an AF network element, a RAN, an NEF network element, and a UPF network element in FIG. 2, or may be network elements that have functions of the AMF network element, the SMF network element, the PCF network element, the AF network element, the RAN, the NEF network element, and the UPF network element in future communication such as a 6th generation (6G) network. This is not limited in the embodiments. For ease of description, that the mobility management network element, the session management network element, the policy control network element, the application function network element, the access network device, the network exposure function network element, and the user plane network element are respectively the AMF network element, the SMF network element, the PCF network element, the AF network element, the RAN, the NEF network element, and the UPF network element is used an example for description in the embodiments.

FIG. 3 is a schematic diagram of an architecture of an MEC system according to an embodiment. An MEC server is deployed between a radio access network and a core network. The MEC server is a server on which an MEC platform is deployed and that is managed by the MEC platform. In addition, the MEC server may be connected to a cloud data center and another network, for example, an enterprise network. In this way, the MEC server provides a service and a cloud computing function for a terminal nearby by using the radio access network. In this embodiment, the MEC server may be established by a carrier, an enterprise, a virtual network operator, or a service provider. Alternatively, the UPF network element in FIG. 2 may be integrated into the MEC server.

The method provided in the embodiments may be applied to the following two MEC architectures.

Manner 1: A reference architecture of MEC defined by ETSI in the ETSI GS MEC 003 specification. For details, refer to FIG. 1. For a description of FIG. 1, refer to the background. Details are not described again.

Manner 2: A reference architecture of MEC defined by the 3GPP SA6 working group, as shown in FIG. 3A or FIG. 3B. A difference between FIG. 3B and FIG. 3A lies only in that, in FIG. 3B, functions of an edge enabler client (EEC) and an edge data network configuration client (EDN CC) are integrated to form an enabler client, as shown in FIG. 3B, that has functions of the EDN CC and the EEC. The following briefly describes function modules and interfaces between the function modules in FIG. 3A and FIG. 3B.

Edge data network (EDN): The EDN is configured to provide an edge computing service for a terminal, and may include functions such as computing, storage, network, communication, and routing. The EDN may generally include an edge computing management platform (for example, an edge enabler server (EES) below) and an edge application instance (for example, an edge application server (EAS)). In an understanding, the EDN may be a local data network (DN), and represents an access point of a data network that is physically closest to a user attachment point (that is, an access network device (for example, a base station) accessed by the terminal). One data network may have a plurality of local data networks. The local data network may be identified by using a data network name (DNN) and/or a data network application identifier (DNAI). The DNAI may identify a location of the local data network. In another understanding, the EDN is a peer-to-peer concept of a central cloud, that is, the EDN may be understood as a local data center and may support a plurality of local data networks. The data center may also be identified by using a DNAI.

EAS: The EAS is configured to provide an application service having an edge computing feature for an application client and is an instance of a server application (for example, social media software, augmented reality (AR), or virtual reality (VR)) that is deployed and runs on the EDN. One MEC application may have one or more EASs deployed in one or more EDNs. EASs deployed and running in different EDNs may be considered as different EASs. The EASs may share a domain name and may use a same IP address or different IP addresses. The EAS may also be referred to as an edge application, an application instance, an edge application instance, an MEC application, an MEC application instance, an EAS function, or the like.

Application client: the application client is used by an application user to obtain an application service from an application server. The application client is a client program of the MEC application on a terminal side. The application client may be connected to an application server on a cloud to obtain an application service or may be connected to an EAS deployed and running in one or more EDNs to obtain an application service.

EES: The EES is configured to provide some edge computing enabling services for the EAS and the EEC, so as to better support deployment of the MEC application at an edge. The EES may support EAS registration, terminal authentication and authorization, a DNS function that provides IP address information of the application server for the terminal, and the like. The EDN includes the EES. Generally, the EAS is registered with an EES, or information about the EAS is configured on an EES by using a management system. The EES is referred to as an EES associated with the EAS. The EES controls (or manages) the EAS that is registered with (or configured on) the EES.

EEC: The EEC is a peer entity of the EES on the terminal side. The EEC is configured to: register information about the EEC and information about the application client with the EES, perform security authentication and authorization, obtain an IP address of the EAS from the EES, and provide an edge computing enabling capability for the application client, for example, an EAS discovery service returns the IP address of the EAS to the application client. The EEC can also invoke a service interface provided by the EDN CC.

Edge data network configuration server (EDN CS): The EDN CS is configured to configure information about the EDN for the terminal, for example, provide information about the EES in the EDN for the terminal. Further, the EDN CS may have the DNS function, and have a domain name of the EAS, an IP address of the EAS, and information about the EES with which the EAS registers. The EDN CS may further directly provide the information about the EAS for the terminal and interact with a DNS server of the MEC application to obtain information about the application server. The EDN CS may accept an EES query or an EAS query of the EDN CC and provide a corresponding query result. The EDN CS may accept EES registration to obtain the domain name of the EAS, the IP address of the EAS, and the information about the EES with which the EAS registers. The information may also be obtained through configuration.

EDN CC: The EDN CC is a peer entity of the EDN CS on the terminal side. The EDN CC may obtain the information about the EES from the EDN CS, and may further obtain the information about the EAS from the EDN CS. The EDN CC may be further configured to provide an edge computing enabling service interface for the EEC or the application client.

The application user signs a service agreement with a provider of the MEC application, to provide a service for the application user. The application user logs in to the application client on the terminal and performs communication by using a connection between the application client and the EAS. An enabler client (for example, the EEC or the EDN CC) is a middleware layer, and is generally located in an operating system, or is located in middleware between the application client and the operating system. The application client may obtain an edge enabling service from the enabler client through an application programming interface (API).

Edge-1 interface: The edge-1 interface is an interface between the EEC and the EES, and can implement EEC registration, security authentication, EAS discovery, and application context removal.

Edge-2 interface: The edge-2 interface is an interface between the EES and the 3GPP network, is used to interact with a 3GPP core network element and may be connected to network elements such as a network exposure function (NEF) network element and a policy control function (PCF) network element.

Edge-3 interface: The edge-3 interface is an interface between the EAS and the EES and is used by the EAS to invoke a service such as event subscription and notification provided by the EES, and by the EAS to register with the EES.

Edge-4 interface: The edge-4 interface is an interface between the EDN CS and the EDN CC, and is used by the EDN CS to provide the information about the EES, EAS discovery, security authorization, and the like for the EDN CC.

Edge-5 interface: The edge-5 interface is an interface between the application client and the EEC and is used by the application client to invoke a service provided by the EEC, such as EAS discovery, event subscription and notification, and context removal.

Edge-6 interface: The edge-6 interface is an interface between the EES and the EDN CS and is used by the EES to register the information about the EES with the EDN CS, further including the information about the EAS registered with the EES.

Edge-7 interface: The edge-7 interface is an interface between the EAS and the 3GPP network, is used to interact with the 3GPP core network element and may be connected to network elements such as the NEF network element and the PCF network element.

Edge-X interface: The edge-X interface is an interface between the EEC and the EDN CC and may be used by the EDN CC to provide the information (such as identifier and address information) about the EES for the EEC.

It should be noted that the function modules in FIG. 3A and FIG. 3B and the interfaces between the function modules may also have other names. This is not limited.

As shown in FIG. 3C, in an actual application scenario, the terminal may communicate with one or more EDNs by using a mobile communication network connection. One or more EESs are deployed in one EDN, and one EES may manage one or more EASs. For example, in FIG. 3C, an EES 1 deployed in an EDN 1 may manage an EAS 11, an EAS 12, and an EAS 13, an EES 2 deployed in an EDN 2 may manage an EAS 21 and an EAS 22, and an EES 3 deployed in an EDN 3 may manage an EAS 31, an EAS 32, and an EAS 33. The EES may store information about each EAS managed by the EES, including an identifier of the EAS, such as a fully qualified domain name (fully qualified domain name, FQDN), and address information of the EAS, such as a URL or an IP address.

EESs deployed in a plurality of EDNs may be connected to a same EDN CS. The EDN CS may store address information of each EES connected to the EDN CS and information about an EAS managed by each EES, for example, an identifier of the managed EAS, and further includes address information of the managed EAS. For example, in FIG. 3C, the EDN CS may store address information of the EES 1, the EES 2, and the EES 3, and further store identifiers and address information of EASs managed by the EES 1, the EES 2, and the EES 3.

EASs of a same MEC application may be deployed in different EDNs. For example, in FIG. 3C, EASs of an MEC application 1 may be the EAS 11, the EAS 21, and the EAS 31, EASs of an MEC application 2 may be the EAS 12, the EAS 22, and the EAS 32, and EASs of an MEC application 3 may be the EAS 13 and the EAS 33. Whether a plurality of EASs are different EASs of a same MEC application may be determined by using the EASs.

In an understanding, it may be considered that an EAS registered with the EES is a capability of the EES. For example, if an EAS of the MEC application 1 is registered with the EES, it may be considered that the capability of the EES includes supporting the MEC application 1. Generally, the EAS is registered with an EES that is located in a same EDN as the EAS. Therefore, it may be understood that an optimal EDN (physically closest, with a shortest network connection path, or with an optimal network connection path) to a terminal may provide an EES and an EAS that are closest to the terminal.

In an embodiment, for ease of description, the MEC application instance in the architecture shown in FIG. 1 and the EAS in FIG. 3A to FIG. 3C are collectively referred to as an MEC application instance, and the MEC application instance is a copy of a same MEC application. The MEC application instance is deployed on an edge node (for example, EDN). A plurality of MEC application instances can be deployed on a same edge node to implement load balancing. For an MEC application installed on the terminal, an MEC application instance that is of an edge node and that is corresponding to the MEC application provides a service for the MEC application at a moment. Generally, a shorter distance between a location of the edge node on which the MEC application instance is deployed and a location of the terminal indicates a shorter latency of packet transmission between the MEC application instance and the terminal, and higher quality of service. As shown in FIG. 4, when the terminal is at a location 1, an MEC application instance 1 on an edge node 1 may be considered as an optimal MEC application instance. When the terminal moves to a location 2, an MEC application instance 2 on the edge node 2 may be considered as the optimal MEC application instance. Currently, there is no method for providing the optimal MEC application instance for the MEC application of the terminal.

Based on the network architecture shown in FIG. 2 and the MEC architectures shown in FIG. 1, FIG. 3, FIG. 3A, FIG. 3B, and FIG. 3C, FIG. 5 is a schematic diagram of a communication method (which may also be referred to as a method for determining an MEC application instance) according to an embodiment. In the embodiment shown in FIG. 5, a process of discovering the MEC application instance is used as an example and includes the following steps.

S501: A terminal sends a first message to a first network element, where the first message may be an MEC application instance discovery request message. Correspondingly, the first network element receives the first message from the terminal.

In the MEC architecture shown in FIG. 1, the first network element may be an MEC system management plane function network element, and step S501 may be performed by a terminal application.

In the MEC architectures shown in FIG. 3A, FIG. 3B, and FIG. 3C, the first network element may be an EES or an EDN CS. If the first network element is an EES, step S501 may be performed by an EEC in the terminal. If the first network element is an EDN CS, step S501 may be performed by an EDN CC or an EEC in the terminal.

The MEC application instance discovery request message reaches the first network element from the terminal through an access network device (for example, a gNB) and a user plane gateway (for example, a UPF network element).

The MEC application instance discovery request message includes one or more of the following information:

(1) Terminal identifier

The terminal identifier may be a subscription permanent identifier (SUPI), a generic public subscription identifier (GPSI), a media access control (MAC) address, an IP address, a mobile station international subscriber directory number (MSISDN), or another identifier. The terminal identifier may be used to determine a location of the terminal.

(2) MEC application name

(3) MEC application provider name

(4) MEC application version

(5) MEC application identifier

An identifier information element of the MEC application may include identifiers of one or more MEC applications. An identifier of one MEC application may be an FQDN of the MEC application, a URL of the MEC application, or the like. The identifier of the MEC application is used to indicate requesting to obtain address information of a corresponding EAS. For example, if the identifier of the MEC application is an identifier of an MEC application 1, it indicates that address information of an EAS of the MEC application 1 is obtained. If the first message does not include the identifier of the MEC application, it may indicate that address information of EASs of all MEC applications is obtained.

(6) Information about an application client

The information about the application client may be information used by the EAS to identify the terminal. The information about the application client may be the GPSI, the IP address, or an identifier formed by a combination of other characters. The information about the application client may be used to indicate to request to support EASs corresponding to these application clients.

(7) Identifier of an EEC

The identifier of the EEC is used to identify the EEC. The identifier of the EEC may be the GPSI, the IP address, or a combination of other characters used to identify the EEC. The identifier of the EEC may be used to perform authentication and authorization on the terminal and obtain location information of the terminal (for example, determine the SUPI, the GPSI, and the like of the terminal by using the identifier of the EEC, to determine a location of the terminal).

(8) Location information of the terminal

The location information of the terminal may be any information that can indicate the location of the terminal, such as coordinates of the location of the terminal, information (for example, an identifier of a cell) about a cell in which the terminal is located, tracking area information (for example, an identifier of a tracking area) about a tracking area in which the terminal is located, or an identifier of a data network access point of the terminal. The location information of the terminal may be used to determine the location of the terminal.

S502: The first network element determines first at least one MEC application instance.

During implementation of step S502, the first network element needs to first obtain the location information of the terminal, and then determine the first at least one MEC application instance based on the location information of the terminal.

Optionally, if the MEC application instance discovery request message received by the first network element includes the location information of the terminal, it is considered that the first network element obtains the location information of the terminal by receiving the MEC application instance discovery request message. If the MEC application instance discovery request message does not include the location information of the terminal, another optional method is that the first network element obtains the location information of the terminal from a telecom operator network function network element such as a 5G core network control plane function network element (for example, an NEF network element) based on the terminal identifier. The NEF network element provides an API to open a telecom network capability. The first network element sends a location query request including the terminal identifier to the NEF network element. After receiving the location query request, the NEF network element invokes a network function such as an AMF network element of a core network to obtain location information. The AMF network element sends the queried location information of the terminal to an invoker, that is, the NEF network element. The NEF network element sends a second message to the first network element. The second message includes the location information of the terminal.

S503: The first network element sends address information of the first at least one MEC application instance to the terminal. Correspondingly, the terminal receives the address information of the first at least one MEC application instance from the first network element.

For example, if the terminal requests an MEC application instance of the MEC application 1, the first MEC application instance may be the MEC application instance of the MEC application 1.

The address information of the first at least one MEC application instance may be carried in an MEC application instance discovery response message.

Address information of an MEC application instance may be an IP address, a URL, an identifier, a port number, address connection information that can be uniquely connected to the MEC application instance, or the like of the MEC application instance.

If the first at least one MEC application instance is one first MEC application instance, the first MEC application instance may be an optimal MEC application instance determined by the first network element. In this case, the terminal may use the first MEC application instance as an MEC application instance providing a service.

If the first at least one MEC application instance is a plurality of first MEC application instances, the plurality of first MEC application instances may be a plurality of optimal MEC application instances determined by the first network element. In this case, the terminal may select an optimal MEC application instance from the MEC application instances as the MEC application instance providing the service. A method for determining, by the terminal, which MEC application instance is the optimal MEC application instance is not limited.

Optionally, when the first at least one MEC application instance is the plurality of first MEC application instances, the method further includes: The first network element sends priority information of the first at least one MEC application instance to the terminal. In this case, the terminal may select an MEC application instance with the highest priority from the MEC application instances as the MEC application instance providing the service. Further, the terminal may alternatively select another MEC application instance as the MEC application instance providing the service.

In this embodiment, when the terminal requests the MEC application instance, the first network element determines, based on the obtained location information of the terminal, the MEC application instance providing the service for the terminal. This reduces a latency of packet transmission between the MEC application instance and the terminal and improves quality of services.

The first network element may be responsible for life cycle management of an MEC application, including selection of a deployment location of the MEC application instance. The first network element stores information about each MEC application instance, including an identifier of the MEC application instance, an address of the MEC application instance, a deployment location of the MEC application instance, and a correspondence between the information. The first network element determines the first at least one MEC application instance from the MEC application instance based on the location information of the terminal and the location information of the MEC application instance. In other words, the first network element determines, as the first MEC application instance based on the location information of the terminal, one or more MEC application instances closest to a location identified by the location information. A quantity of first MEC application instances to be determined by the first network element may be predefined, preset, or specified in a protocol. This is not limited.

For example, if the terminal requests the MEC application instance of the MEC application 1, the terminal can access a total of five MEC application instances of the MEC application 1, and the five MEC application instances are denoted as an MEC application instance 1, an MEC application instance 2, an MEC application instance 3, an MEC application instance 4, and an MEC application instance 5. Distances between the terminal and each of the MEC application instance 3, the MEC application instance 2, the MEC application instance 1, the MEC application instance 4, and the MEC application instance 5 are in ascending order. If the first at least one MEC application instance is one first MEC application instance, the first network element may determine that the MEC application instance 3 is the first at least one MEC application instance. If the first at least one MEC application instance is three first MEC application instances, the first network element may determine that the MEC application instance 3, the MEC application instance 2, and the MEC application instance 1 are the first at least one MEC application instance.

Based on the network architecture shown in FIG. 2 and the MEC architectures shown in FIG. 1, FIG. 3, FIG. 3A, FIG. 3B, and FIG. 3C, FIG. 6 is a schematic diagram of another communication method (which may also be referred to as another method for determining an MEC application instance) according to an embodiment. In the embodiment shown in FIG. 6, a change procedure of the MEC application instance is used as an example. Alternatively, after the MEC application instance shown in FIG. 5 is determined, the method in this embodiment may be performed when the MEC application instance needs to be changed. As shown in FIG. 6, the method includes the following steps.

S601: A first network element subscribes to a user plane path change notification event (which is a user plane path management event) from a core network control plane function network element such as an NEF network element, a PCF network element, or an SMF network element. The first network element may subscribe to the user plane path change notification event by sending a user plane path change subscription request message. After completing sending, the first network element receives response information sent by the core network control plane function network element.

In the MEC architecture shown in FIG. 1, the first network element may be an MEC system management plane function network element. In the MEC architectures shown in FIG. 3A, FIG. 3B, and FIG. 3C, the first network element may be an EES or an EDN CS.

A terminal accesses an application network (for example, an EDN) by using a UPF network element, and different UPF network elements access application networks at different locations. When the terminal moves between different locations, a core network switches user plane paths and selects an optimal UPF network element, to reduce an access latency between the terminal and the application network and improve user experience. The user plane path changes when the terminal is switched to a new UPF network element.

S602: The terminal sends an MEC application instance change subscription request message to the first network element. The MEC application instance change subscription request message includes at least one of information such as a terminal identifier, an MEC application name, an MEC application provider name, and an MEC application version. After completing sending, the terminal receives response information sent by the first network element.

If the first network element is the MEC system management plane function network element, step S602 may be performed by a terminal application. If the first network element is an EES, step S602 may be performed by an EEC in the terminal. If the first network element is an EDN CS, step S602 may be performed by an EDN CC in the terminal.

S603: The core network control plane function network element sends first notification information to the first network element, to notify the first network element that the user plane path of the terminal changes, where the first notification information may be user plane path change notification information. Because the terminal moves, the core network control plane function network element is triggered to select the optimal UPF network element for the terminal that moves to a new location. When a new UPF network element is switched, user plane switching is performed. The core network control plane function network element sends the user plane path change notification information to the first network element. The user plane path change notification information includes the terminal identifier (for example, an IP address or a generic public subscriber identity of the terminal), source user plane location information, and destination user plane location information. User plane location information may be a DNAI, and there is a correspondence between the DNAI and a cell.

S604: The first network element determines source MEC application instance information based on the terminal identifier and the source user plane location information, determines a destination MEC application instance based on the terminal identifier and a destination user plane location, and determines a new MEC application instance based on the destination user plane location, which may also refer to step S502 in the embodiment shown in FIG. 5. The first network element may obtain location information of a destination UPF network element by receiving the user plane path change notification information. If there are a plurality of destination MEC application instances, one MEC application instance may be selected at random or an instance with the lightest load may be selected. After determining the new MEC application instance, the first network element indicates the source MEC application instance and the destination MEC application instance to complete terminal context removal. The determined MEC application instance is the first MEC application instance.

The first network element sends response information of the user plane path change notification to the core network control plane function network element, so that a core network control plane network function network element controls a user plane to complete path switching.

In this embodiment, the destination UPF location information may also be considered as a current location of the terminal and is a form of the location information of the terminal.

S605: The first network element sends the MEC application instance change notification information to the terminal. The MEC application instance change notification information includes information about the destination MEC application instance, for example, at least one of an MEC application name, an MEC application provider name, an MEC application version, an MEC application instance identifier, and an MEC application instance address. After receiving the MEC application instance change notification information, the terminal may send response information to the first network element.

The terminal subsequently switches to use the new MEC application instance, that is, the destination MEC application instance.

In this embodiment, when a UPF network element serving the terminal changes, a current MEC application instance may not be optimal. The first network element determines, based on the location information (the destination user plane location) of the terminal, an optimal MEC application instance after the terminal switches to a new UPF network element. This reduces a latency of packet transmission between the MEC application instance and the terminal and improves quality of services.

Based on the network architecture shown in FIG. 2 and the MEC architectures shown in FIG. 3, FIG. 3A, FIG. 3B, and FIG. 3C, FIG. 6A is a schematic diagram of a communication method (which may also be referred to as a method for determining an application instance) according to an embodiment. In the embodiment shown in FIG. 6A, a process of discovering an MEC application instance is used as an example and includes the following steps.

S601A: A terminal sends a first message to a first network element. Correspondingly, the first network element receives the first message from the terminal.

The first message is used to request address information of the MEC application instance, and the address information of the MEC application instance is used by the terminal to connect to the MEC application instance. The first message may be an MEC application instance discovery request message.

In the MEC architectures shown in FIG. 3A, FIG. 3B, and FIG. 3C, the first network element may be an EES or an EDN CS. If the first network element is an EES, step S601A may be performed by an EEC in the terminal. If the first network element is an EDN CS, step S601A may be performed by an EDN CC or an EEC in the terminal.

Information included in the MEC application instance discovery request message in the embodiment shown in FIG. 6A is similar to the information included in the MEC application instance discovery request message in the embodiment shown in FIG. 5. Details are not described again.

S602A: The first network element obtains information about first at least one EDN from an SMF network element, where the first at least one EDN is determined based on location information of the terminal.

S603A: The first network element determines first at least one MEC application instance in the first at least one EDN.

S604A: The first network element sends address information of the first at least one MEC application instance to the terminal.

For example, if the terminal requests an MEC application instance of an MEC application 1, the first MEC application instance may be the MEC application instance of the MEC application 1.

The address information of the first at least one MEC application instance may be carried in an MEC application instance discovery response message.

Address information of an MEC application instance may be an IP address, a URL, address connection information that can be uniquely connected to the MEC application instance, or the like of the MEC application instance.

Optionally, when the first at least one MEC application instance is a plurality of first MEC application instances, the method further includes: The first network element sends priority information of the first at least one MEC application instance to the terminal. In this case, the terminal may select an MEC application instance with the highest priority from the MEC application instances as an MEC application instance providing a service. Additionally, the terminal may alternatively select another MEC application instance as the MEC application instance providing the service.

In this embodiment, when the terminal requests the MEC application instance, the first network element requests the information about the first at least one EDN from the SMF network element, to determine the first at least one MEC application instance. This reduces a latency of packet transmission between the MEC application instance and the terminal and improves quality of services.

Optionally, during implementation, step S602A includes:

(11) The first network element sends a third message to the SMF network element, where the third message is used to request at least one EDN that includes the MEC application instance requested by the terminal. Correspondingly, the SMF network element receives the third message from the first network element.

(12) The SMF network element sends the information about the first at least one EDN to the first network element based on the third message, where the first at least one EDN includes an EDN that includes the MEC application instance requested by the terminal. Correspondingly, the first network element receives a response message of the third message from the SMF network element.

The information about the first at least one EDN may be carried in the response message of the third message.

For example, the third message may be a user plane management event notification message subscribed by the first network element from the SMF network element, and the response message of the third message may be a user plane management event notification sent by the SMF network element to the first network element. The response message of the third message may be a notification message immediately sent by the SMF network element to the first network element after receiving a subscription message. The notification message includes information about an EDN corresponding to a current location of the terminal, for example, current user plane location information DNAI of the terminal.

The third message is used to request at least one EDN that includes the MEC application instance requested by the terminal. It may be understood that a third request message is used to request an EDN that meets a filter condition. The filter condition describes a condition that needs to be met by the MEC application instance requested by the terminal. The filter condition may be sent by the terminal to the first network element in the first message or may be independently generated by the first network element. For example, the third request message may further carry a filter, used to indicate to request information about the EDN that meets the filter. For example, the filter may be an MEC application instance deployed with an MEC application X, and this indicates to request an EDN of the MEC application instance deployed with the MEC application X.

Optionally, information about the first at least one EDN is used to indicate performance of a communication path between the terminal and the first at least one EDN. Because the EES and the MEC application instance are deployed in the EDN, it may also be considered that the information about the first at least one EDN may be further used to indicate: performance of a communication path between the terminal and the EES in the first at least one EDN, and/or performance of a communication path between the terminal and the MEC application instance in the first at least one EDN.

Performance of the communication path may include performance indicators such as a network topology distance of the communication path, a latency of the communication path, and a bandwidth of the communication path.

The first at least one EDN and the information about the at least one EDN may be any one of the following:

Case 1: The first at least one EDN includes all EDNs that include the MEC application instance requested by the terminal, and the information about the first at least one EDN (denoted as first information of the first at least one EDN) includes any one or more of the following information: a quantity of UPF network elements between the terminal and the first at least one EDN, an internal mobile network communication latency between the terminal and the first at least one EDN, an end-to-end communication latency between the terminal and the first at least one EDN, an internal mobile network communication bandwidth between the terminal and the first at least one EDN, and priority information of the communication path between the terminal and the first at least one EDN.

I It may also be considered that the first information of the first at least one EDN includes any one or more of the following information: a quantity of UPF network elements between the terminal and the EES in the first at least one EDN, an internal mobile network communication latency between the terminal and the EES in the first at least one EDN, an end-to-end communication latency between the terminal and the EES in the first at least one EDN, an internal mobile network communication bandwidth between the terminal and the EES in the first at least one EDN, and priority information of the communication path between the terminal and the EES in the first at least one EDN. Alternatively, it may be considered that the first information of the first at least one EDN includes any one or more of the following information: a quantity of UPF network elements between the terminal and the MEC application instance in the first at least one EDN, an internal mobile network communication latency between the terminal and the MEC application instance in the first at least one EDN, an end-to-end communication latency between the terminal and the MEC application instance in the first at least one EDN, an internal mobile network communication bandwidth between the terminal and the MEC application instance in the first at least one EDN, and priority information of the communication path between the terminal and the MEC application instance in the first at least one EDN.

For ease of description, the EDN that includes the MEC application instance requested by the terminal is denoted as a target EDN below. Optionally, the third message includes information (for example, an identifier of an MEC application) used to indicate the MEC application corresponding to the MEC application instance requested by the terminal. The SMF network element may determine, based on the information, the MEC application corresponding to the MEC application instance requested by the terminal, and further determine the EDN that includes the MEC application instance of the MEC application as the target EDN.

In the case 1, the SMF network element does not need to select from all the target EDNs, and only needs to use all the target EDNs as the first at least one EDN.

In the case 1, optionally, the response message of the third message sent by the SMF network element to the first network element includes priority information of the first at least one EDN.

Case 2: The first at least one EDN is all the target EDNs, and information about one first EDN (denoted as second information of the first EDN) is a DNAI of the first EDN.

In the case 2, the SMF network element does not need to select from all the target EDNs, and only needs to use all the target EDNs as the first at least one EDN.

In the case 2, optionally, the response message of the third message sent by the SMF network element to the first network element includes priority information of the first at least one EDN.

Case 3: The first at least one EDN is all the target EDNs, and the information about one first EDN is an identifier of the first EDN and priority information of the first EDN.

In the case 3, the SMF network element does not need to select from all the target EDNs, and only needs to determine priorities of all the target EDNs.

Case 4: The first at least one EDN is a part of target EDNs. Information about one first EDN is the first information of the first EDN.

In the case 4, the SMF network element may select a part of target EDNs from all the target EDNs as the first at least one EDN.

In the case 4, optionally, the response message of the third message sent by the SMF network element to the first network element includes priority information of the first at least one EDN.

Case 5: The first at least one EDN is a part of target EDNs, and the information about one first EDN is the DNAI of the first EDN.

In the case 5, the SMF network element may select a part of target EDNs from all the target EDNs as the first at least one EDN.

In the case 5, optionally, the response message of the third message sent by the SMF network element to the first network element includes priority information of the first at least one EDN.

Case 6: The first at least one EDN is a part of target EDNs, and the information about one first EDN is the identifier of the first EDN and the priority information of the first EDN.

In the case 6, the SMF network element may select a part of target EDNs from all the target EDNs as the first at least one EDN.

In the case 4 to the case 6, that the SMF network element selects a part of target EDNs from all the target EDNs as the first at least one EDN may be implemented in any one of the following manner 1 to manner 3.

Manner 1

The SMF network element may determine, based on the location information of the terminal and location information of the target EDN, that one or more target EDNs closest to a location of the terminal in all the target EDNs are the first at least one EDN. A shorter distance from the terminal indicates better performance of communication with the terminal.

The location information of the terminal may be carried in the third message, or the SMF network element determines the location information of the terminal based on an identifier of the terminal. Location information of the EDN may be determined based on a DNAI of the EDN. That the target EDN is closest to the terminal means that a network connection distance between the target EDN and the terminal is the smallest.

For example, based on the example shown in FIG. 3C, if the terminal requests the MEC application instance of the MEC application 1, all the target EDNs may be the EDN 1, the EDN 2, and the EDN 3. If the first at least one EDN includes two EDNs, and distances between the terminal and each of the EDN 2, the EDN 1, and the EDN 3 are in ascending order, the SMF network element may determine that the EDN 2 and the EDN 1 are the first at least one EDN.

Manner 2

The SMF network element may determine, based on the first information of the target EDN, one or more target EDNs with best communication performance with the terminal in all the target EDNs as the first at least one EDN.

Communication performance between one EDN and the terminal may be represented by one or more parameters of a quantity of UPF network elements between the terminal and the EDN, an internal mobile network communication latency between the terminal and the EDN, and an end-to-end communication latency between the terminal and the EDN, an internal mobile network communication bandwidth between the terminal and the EDN, and a performance indicator of another communication path.

Based on different parameters representing communication performance between the EDN and the terminal, the first at least one EDN determined by the SMF network element may also be different. For example, if the communication performance between the EDN and the terminal is represented by the end-to-end communication latency between the terminal and the EDN, and if the first at least one EDN is three first EDNs, the SMF network element may use, as the first at least one EDN, three target EDNs that are in all the target EDNs and that have minimum end-to-end communication latencies with the terminal.

Manner 3

The SMF network element may determine the first at least one EDN based on the location information of the terminal and information about a candidate EDN.

The SMF network element may determine the first at least one EDN based on the location information of the terminal, the information about the candidate EDN, and first information of candidate or all EDNs. The candidate EDN may be the target EDN or may not be the target EDN. This is not limited.

For example, if the candidate EDN is a candidate target EDN, the SMF network element may determine one or more target EDNs with best communication performance with the terminal in candidate target EDNs as the first at least one EDN. For another example, the SMF network element may determine one or more target EDNs with best communication performance with the terminal in candidate target EDNs and one or more target EDNs with best communication performance with the terminal in non-candidate target EDNs as the first at least one EDN.

Optionally, the information about the candidate EDN is carried in the third message, and the candidate EDN is determined by the first network element based on the location information of the terminal and information about an EDN stored in the first network element. There may be one or more candidate EDNs. The first network element may determine, based on the location information of the terminal, one or more EDNs (or target EDNs) closest to the terminal as candidate EDNs (or target EDNs). In this case, the first network element may be the EDN CS. Optionally, the SMF network element may determine, based on information (for example, an identifier of the MEC application) that is in the first message and that is used to indicate the MEC application corresponding to the MEC application instance requested by the terminal, the MEC application corresponding to the MEC application instance requested by the terminal, so as to determine that an EDN that includes the MEC application instance of the MEC application is the target EDN.

In the case 1 to the case 6, optionally, priority of the first at least one EDN may be determined based on a distance between the first at least one EDN and the terminal or may be determined based on communication performance between the first at least one EDN and the terminal. For example, the SMF network element may set a higher priority for a first EDN closer to the terminal or set a higher priority for a first EDN with better communication performance with the terminal.

It should be noted that, in a case in which the response message of the third message includes the priority of the first at least one EDN, during implementation of step (12), the first network element may determine, as the first at least one MEC application instance, an MEC application instance that is requested by the terminal and that is in a part of or all the target EDNs in the first at least one EDN. In the case 1, the case 2, the case 4, and the case 5, if the response message of the third message does not include the priority of the first at least one EDN, during implementation of step (12), the first network element may determine the priority of the first at least one EDN based on the information about the first at least one EDN, and then determine, as the first at least one MEC application instance, an MEC application instance that is requested by the terminal and that is in a part of or all the first EDNs in the first at least one EDN.

A method for determining the priority of the first at least one EDN by the first network element is the same as that of the SMF network element. For details, refer to the foregoing description. Details are not described again.

Further, the first network element may alternatively determine the first at least one MEC application instance by using another method. For example, after receiving the information about the first at least one EDN, the first network element determines, with reference to load of the first at least one EDN, one or more first EDNs with relatively light load, and determines, as the first at least one MEC application instance, an MEC application instance that is requested by the terminal and that is in the one or more first EDNs with relatively light load.

In this embodiment, if the first network element is the EDN CS, after determining the first at least one MEC application instance, the first network element may further determine an EES associated with the first at least one MEC application instance. The EES associated with the first at least one MEC application instance is included in the first at least one EDN. In this case, optionally, the method further includes: The first network element sends address information of the EES associated with the first at least one MEC application instance to the terminal. After receiving the information, the terminal may first access the EES, and then access the first MEC application instance managed by the EES.

Based on the network architecture shown in FIG. 2 and the MEC architectures shown in FIG. 3, FIG. 3A, FIG. 3B, and FIG. 3C, FIG. 6B is a schematic diagram of a communication method (which may also be referred to as a method for determining an EES) according to an embodiment. In the embodiment shown in FIG. 6B, a process of discovering an EES is used as an example and includes the following steps.

S601B: A terminal sends a first message to a first network element. Correspondingly, the first network element receives the first message from the terminal.

The first message may be used to request address information of the EES, and the address information of the EES is used to connect to the EES. The first message may be an EES discovery request message.

The first network element may be an EDN CS, and step S601B may be performed by an EDN CC or an EEC in the terminal.

The EES discovery request message reaches the first network element from the terminal through an access network device (for example, a gNB) and a user plane gateway (for example, a UPF network element).

Information included in the EES discovery request message is similar to the MEC application instance discovery request message in the embodiment shown in FIG. 5, and a difference lies only in that: In the EES discovery request message, a function of information about an MEC application instance in the MEC application instance discovery request message is to indicate to obtain address information of an EES of an MEC application instance indicated by information for managing the MEC application instance.

S602B: The first network element obtains information about first at least one EDN from an SMF network element, where the first at least one EDN is determined based on location information of the terminal.

S603B: The first network element determines first at least one EES in the first at least one EDN.

S604B: The first network element sends address information of the first at least one EES to the terminal. Correspondingly, the terminal receives the address information of the first at least one EES from the first network element.

For example, if the terminal requests an EES that manages an MEC application instance of an MEC application 1, a first EES may be the EES that manages the MEC application instance of the MEC application 1.

The address information of the first at least one EES may be carried in a response message of the first message, and the response message of the first message may be an EES discovery response message.

Address information of an EES may be an IP address, a URL, other address connection information that can be uniquely connected to the EES, or the like of the EES.

Optionally, when the first at least one EES includes a plurality of first EESs, the method further includes: The first network element sends priority information of the first at least one EES to the terminal. In this case, the terminal may select an EES with the highest priority from the EESs as an EES providing a service. Further, the terminal may alternatively select another EES as the EES providing the service.

In this embodiment, when the terminal requests the EES, the first network element requests the information about the first at least one EDN from the SMF network element, to determine the first at least one EES. This reduces a latency of packet transmission between the terminal and an MEC application instance managed by the EES and improves quality of services.

Optionally, during implementation, step S602B includes:

(21) The first network element sends a third message to the SMF network element, where the third message is used to request at least one EDN that includes the EES requested by the terminal. Correspondingly, the SMF network element receives the third message from the first network element.

(22) The SMF network element sends the information about the first at least one EDN to the first network element based on the third message, where the first at least one EDN includes an EDN that includes the EES requested by the terminal. Correspondingly, the first network element receives a response message of the third message from the SMF network element.

The information about the first at least one EDN may be carried in the response message of the third message.

The third message is used to request at least one EDN that includes the EES requested by the terminal. It may be understood that a third request message is used to request an EDN that meets a filter condition. The filter condition describes a condition that needs to be met by the EES requested by the terminal. The filter condition may be sent by the terminal to the first network element in the first message or may be independently generated by the first network element. For example, the third request message may further carry a filter, used to indicate to request information about the EDN that meets the filter. For example, the filter may be an EES that manages an MEC application instance of an MEC application X, and this indicates to request an EDN that includes the EES that manages the MEC application instance of the MEC application X.

Optionally, information about the first at least one EDN is used to indicate communication performance of a communication path between the terminal and the first at least one EDN. Because the EES and the MEC application instance are deployed in the EDN, it may also be considered that the information about the first at least one EDN is used to indicate: communication performance of a communication path between the terminal and the EES in the first at least one EDN, and/or communication performance of a communication path between the terminal and the MEC application instance in the first at least one EDN.

The first at least one EDN and the information about the at least one EDN may be any one of the following:

Case 1: The first at least one EDN includes all EDNs that include the EES requested by the terminal, and the information about the first at least one EDN (denoted as first information of the first at least one EDN) includes any one or more of the following information: a quantity of UPF network elements between the terminal and the first at least one EDN, an internal mobile network communication latency between the terminal and the first at least one EDN, an end-to-end communication latency between the terminal and the first at least one EDN, an internal mobile network communication bandwidth between the terminal and the first at least one EDN, and priority information of the communication path between the terminal and the first at least one EDN.

It may also be considered that the first information of the first at least one EDN includes any one or more of the following information: a quantity of UPF network elements between the terminal and the EES in the first at least one EDN, an internal mobile network communication latency between the terminal and the EES in the first at least one EDN, an end-to-end communication latency between the terminal and the EES in the first at least one EDN, an internal mobile network communication bandwidth between the terminal and the EES in the first at least one EDN, and priority information of the communication path between the terminal and the EES in the first at least one EDN. Alternatively, it may be considered that the first information of the first at least one EDN includes any one or more of the following information: a quantity of UPF network elements between the terminal and the MEC application instance in the first at least one EDN, an internal mobile network communication latency between the terminal and the MEC application instance in the first at least one EDN, an end-to-end communication latency between the terminal and the MEC application instance in the first at least one EDN, an internal mobile network communication bandwidth between the terminal and the MEC application instance in the first at least one EDN, and priority information of the communication path between the terminal and the MEC application instance in the first at least one EDN.

For ease of description, the EDN that includes the EES requested by the terminal is denoted as a target EDN below. Optionally, the third message includes information used to indicate the EES requested by the terminal. The SMF network element may determine, based on the information, the EES requested by the terminal, and further determine the EDN that includes the EES as the target EDN.