A communication method, apparatus, and system

Abstract

The application relates to a communication method, device and system. A first network element learns that a terminal device requests to access a first application, and selects a first data network access identifier for the terminal device, wherein the sum of a first time delay and a second time delay is less than or equal to an access time delay threshold of the first application. The first time delay is a transmission time delay between the terminal device and a core network device corresponding to the first data network access identifier, or a transmission time delay between an access network device serving the terminal device and the core network device corresponding to the first data network access identifier; and the second time delay is a processing time delay of an edge application server in a first data network, the first data network access identifier being used to identify the first data network, and the edge application server being used to support the first application. The selection of the first network element is more conducive to the terminal device to quickly access the first application, thereby improving the access experience of a user using the terminal device for a service of the application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, and particularly relates to a communication method, device and system. BACKGROUND

[0002] In the prior art, after a session management function (SMF) discovers a data network (DN) closest to a user equipment (UE), the SMF can provide an address of an edge application server (EAS) in the DN for the UE. The DN includes multiple local data networks (LDNs), for example, LDN 1, LDN 2 and LDN 3, and EASs 1, 2 and 3 supporting the same application are respectively located in different LDNs to provide the same service for the UE.

[0003] When the UE requests to access the application, the SMF selects the LDN 1 closest to the UE, so that an edge application server discovery function (EASDF) can send the address of the EAS 1 in the LDN 1 to the UE, and the UE accesses the application supported by the EAS 1 according to the address.

[0004] However, the EAS 1 selected by the SMF can not provide a better service quality for the UE. SUMMARY

[0005] Embodiments of the present application provide a communication method and device, which are beneficial to improve the service quality provided for a terminal device.

[0006] In a first aspect, a communication method is provided, which can be performed by a first network element, or by other equipment comprising a function of the first network element, or by a chip system (or chip) or other functional module capable of implementing the function of the first network element, e.g., arranged in the first network element. Optionally, the first network element is, for example, an SMF, or a module or equipment having a function of selecting a data network access identifier. The method comprises: obtaining, by the first network element, that a terminal device requests to access a first application; and selecting, by the first network element, a first data network access identifier for the terminal device, wherein a sum of a first time delay and a second time delay is less than or equal to an access time delay threshold of the first application, the first time delay is a transmission time delay between the terminal device and a core network device corresponding to the first data network access identifier, or a transmission time delay between an access network device serving the terminal device and the core network device corresponding to the first data network access identifier, and the second time delay is a processing time delay of an edge application server in a first data network, the first data network access identifier being used to identify the first data network, and the edge application server being used to support the first application.

[0007] By applying the embodiments of the present application, the selection of the first network element is more conducive to the terminal device to quickly access the first application, so that the terminal device can obtain a faster response of the edge application server for the application, and is conducive to reducing the data transmission time delay between the terminal device and the edge application server supporting the application, thereby improving the access experience of a user using the terminal device for the service of the application.

[0008] In an optional implementation, a sum of the first time delay, the second time delay and a third time delay is less than or equal to the access time delay threshold of the first application, and the third time delay comprises a transmission time delay between the core network device and the edge application server. The embodiments of the present application are expected to reduce the time delay between the terminal device and the edge application server, and the time delay between the terminal device and the edge application server can comprise the transmission time delay between the core network device corresponding to the data network access identifier and the edge application server in addition to the first time delay and the second time delay. Therefore, the third time delay can also be considered when selecting the data network access identifier for the terminal device, which is more conducive to the terminal device to quickly access the first application, thereby further improving the quality of service obtained by the terminal device.

[0009] In an optional implementation, the method further includes: the first network element obtaining at least one data network access identifier, wherein each of the N edge application servers in at least one data network supports the first application, the at least one data network access identifier is used to identify the at least one data network, and N is a positive integer; and the first network element selecting a first data network access identifier for the terminal device, including: the first network element selecting the first data network access identifier for the terminal device from the at least one data network access identifier. The first network element can have at least one selection, for example, the first network element can select the first data network access identifier for the terminal device from the at least one data network access identifier. The more the number of the at least one data network access identifier, the greater the selection range, and the more conducive to the terminal device to quickly access the first application; and the less the number of the at least one data network access identifier, the more the processing process of the first network element can be simplified, and the selection efficiency can be improved.

[0010] In an optional implementation, the method further includes: the first network element obtaining a processing delay of the N edge application servers. The first network element can refer to the processing delay of the edge application servers when selecting a data network access identifier for the terminal device. For example, the first network element can obtain the processing delay of the N edge application servers, so that the first network element can select a first data network access identifier for the terminal device from the at least one data network access identifier according to the obtained processing delay, to more conducive to the terminal device to quickly access the first application.

[0011] In an optional implementation, the first network element obtaining the processing delay of the N edge application servers includes: the first network element receiving association information from a second network element, the association information being used to indicate an association between a load and a processing delay of each of the N edge application servers; and the first network element determining the processing delay of the N edge application servers according to the association information and user information, wherein the user information includes a number of access users of each of the N edge application servers. The first network element can know the association between the load and the processing delay of each of the N edge application servers through the received association information, and the first network element can also know the number of access users of each of the N edge application servers, so that the first network element can determine the processing delay of the N edge application servers in combination with the two kinds of information.

[0012] In an optional implementation, the first network element acquires the processing delays of the N edge application servers, including: the first network element sending a first request to a second network element, the first request being optional to request the processing delays of the EASs in the DN; and the first network element receiving a response to the first request, the response including the processing delays of the N edge application servers. The processing delays of the N edge application servers can be stored in the second network element, and the first network element can acquire the processing delays of the N edge application servers by sending the first request to the second network element.

[0013] In an optional implementation, the first request includes one or more of the following: the identifier of the terminal device, the identifier of the first application, or the at least one data network access identifier. For example, the first request includes the identifier of the terminal device, and the second network element can query the edge application servers that the terminal device has historically accessed, and send the processing delays of the edge application servers to the first network element. For another example, the first request includes the identifier of the first application, and the second network element can query the edge servers that can support the first application, and send the processing delays of the edge application servers to the first network element. For yet another example, the first request includes the at least one data network access identifier, so that the second network element can send the processing delays of the N edge application servers of the data network identified by the at least one data network access identifier to the first network element. It can be seen that the implementation of the first request is flexible.

[0014] In an optional implementation, the processing delays of the N edge application servers include the processing delays of one or more or all of the N edge application servers, or in other words, the processing delays of the N edge application servers only include the processing delays of part or all of the N edge application servers. There can be one or more edge application servers in the data network identified by a data network access identifier, and the performances of different edge application servers in the one or more edge application servers can be the same or different. If the performances of different edge application servers in the one or more edge application servers are different, the processing delays of the N edge application servers can include the processing delays of all of the N edge application servers, and the first network element can implement finer selection granularity when selecting the data network access identifier.

[0015] Or, if the performance of different edge application servers in the one or more edge application servers is the same or similar, the processing time delay of the N edge application servers can include the processing time delay of part or all of the edge application servers in the N edge application servers, for example, for any data network access identifier, the processing time delay of the edge application server in the data network identified by the data network access identifier, including the processing time delay of any edge application server in the data network, without having to include the processing time delay of all edge application servers in the data network. In this way, the number of obtained processing time delays of edge application servers can be reduced, and the processing process can be simplified.

[0016] In an optional implementation, the method further includes: the first network element receiving address information of N edge application servers from a second network element, the N edge application servers being located in at least one data network, the at least one data network being identified by at least one data network access identifier, and the at least one data network including the first data network. The first network element can only select a data network access identifier for the terminal device, without further selecting an edge application server. Or, the first network element can also obtain the address information of the edge application server, so that the first network element can directly select an edge application server in the data network identified by a certain data network access identifier for the terminal device, thereby being able to select a more suitable edge application server for the terminal device, for example, an edge application server with a smaller time delay between the terminal device and the edge application server, to further improve the service quality of the terminal device.

[0017] In an optional implementation, the method further includes: the first network element sending address information of a first edge application server in the first data network to the terminal device, wherein the first edge application server is the edge application server selected by the first network element for the terminal device. If the first network element selects a first edge application server for the terminal device, the first network element can send the address information of the first edge application server to the terminal device, so that the terminal device can access the first edge application server according to the address information. For example, the first network element can directly send the address information to the terminal device, without having to pass through other network elements; or, the first network element can also send the address information to the terminal device through the forwarding of other network elements, for example, the first network element can send the address information to the terminal device through the EASDF or other network elements.

[0018] In an optional implementation, the method further includes: the first network element receiving the access time delay threshold value from a second network element. The first network element can refer to the access time delay threshold value of the first application when selecting a data network access identifier for the terminal device, so the first network element can obtain the access time delay threshold value of the first application in advance.

[0019] In an optional implementation, the method further comprises: the first network element notifying the second network element that the number of access users of the first edge application server changes; or, the first network element updating the number of access users of the first edge application server; wherein the first edge application server is in the first data network. The information indicating the association between the load and the processing delay of each of the N edge application servers can be stored in the second network element, in order to enable the second network element to update the load of the N edge application servers in time, when the load (for example, the number of access users) of the first edge application server changes, the first network element can notify (for example, the first network element sends a request to the second network element) the second network element, so that the second network element can update the number of access users of the first edge application server accordingly, for example, increase or decrease. Alternatively, the information indicating the association between the load and the processing delay of each of the N edge application servers can also be stored in the second network element, and then the first network element can update the number of access users of the first edge application server by itself. In this way, the first network element or the second network element can determine the number of access users of a certain edge application server by itself, without having to request the edge application server for the information, which can reduce the interaction process between network elements, save signaling overhead, and reduce processing delay.

[0020] In a second aspect, another communication method is provided, which can be performed by a second network element, or by other devices including the function of the second network element, or by a chip system (or, a chip) or other functional modules capable of realizing the function of the second network element, for example, arranged in the second network element. Optionally, the second network element is, for example, a UDR. The method comprises: the second network element receiving a first request from a first network element, the first request being used to request to obtain the processing delay of an edge application server in a data network; and the second network element sending a response to the first request to the first network element, the response comprising the processing delay of N edge application servers in at least one data network, the at least one data network being identified by at least one data network access identifier, and N being a positive integer.

[0021] In the embodiments of the present application, the second network element can send the processing delay of the N edge application servers to the first network element in response to the request of the first network element, so as to support the first network element to select a data network access identifier for a terminal device, which is equivalent to adding a reference element for the first network element when selecting a data network access identifier, so that the selection result of the first network element is more conducive to the terminal device to quickly access the first application, and is conducive to improving the quality of service obtained by the terminal device.

[0022] In an optional implementation, the first request comprises one or more of the following: an identifier of a terminal device that can be served by at least one of the N edge application servers, an identifier of a first application that can be supported by at least one of the N edge application servers, or the at least one data network access identifier.

[0023] In an optional implementation, the method further comprises: receiving, by the second network element, association information from a network exposure function network element, the association information being used to indicate an association between a load and a processing delay of each of the N edge application servers; and determining, by the second network element, the processing delay of the N edge application servers according to the association information and user information, wherein the user information comprises a number of access users of each of the N edge application servers.

[0024] In an optional implementation, the method further comprises: detecting, by the second network element, a change in the number of access users of a first edge application server, the first edge application server being located in a first data network of at least one data network, the at least one data network being identified by the at least one data network access identifier; and updating, by the second network element, the number of access users of the first edge application server.

[0025] The technical effects brought by the various optional implementations of the second aspect can be referred to the introduction of the technical effects of the first aspect or the corresponding implementations.

[0026] A third aspect provides an apparatus that can implement the functions of the first network element of the first aspect. The apparatus comprises a processing unit and a transceiver unit. The processing unit is configured to detect a request of a terminal device to access a first application. The processing unit is further configured to select a first data network access identifier for the terminal device, wherein a sum of a first delay and a second delay is less than or equal to an access delay threshold of the first application. The first delay is a transmission delay between the terminal device and a core network device corresponding to the first data network access identifier, or a transmission delay between an access network device serving the terminal device and the core network device corresponding to the first data network access identifier. The second delay is a processing delay of an edge application server in a first data network, the first data network access identifier being used to identify the first data network, and the edge application server being used to support the first application.

[0027] A fourth aspect provides another apparatus comprising one or more processors configured to execute computer program instructions that, when executed by the one or more processors, cause the apparatus to perform any of the methods of the first aspect.

[0028] In a fifth aspect, there is provided yet another apparatus that can implement the functions of the second network element as described in the second aspect above. The apparatus comprises a processing unit and a transceiver unit. The transceiver unit is configured to receive a first request from a first network element, the first request being for requesting processing latency of edge application servers within data networks; and the transceiver unit is further configured to send a response to the first request to the first network element, the response comprising processing latency of N edge application servers within at least one data network, the at least one data network being identified by at least one data network access identification, N being a positive integer.

[0029] In a sixth aspect, there is provided yet another apparatus comprising one or more processors configured to execute computer program instructions that, when executed by the one or more processors, cause the apparatus to perform any of the methods described in the second aspect above.

[0030] In a seventh aspect, there is provided a communication system that can comprise a first network element and a second network element. The first network element is configured to perform any of the methods described in the first aspect above, wherein the first network element is specifically configured to obtain processing latency of edge application servers from the second network element; and the second network element is configured to perform any of the methods described in the second aspect above.

[0031] In an eighth aspect, there is provided yet another communication method that can be performed by the communication system described in the seventh aspect. The method can comprise: sending, by a first network element, a first request to a second network element, the first request being for requesting processing latency of edge application servers within data networks; receiving, by the second network element, the first request, and sending, by the second network element, a response to the first request to the first network element, the response comprising processing latency of N edge application servers within at least one data network, the at least one data network being identified by at least one data network access identification, N being a positive integer; and receiving, by the first network element, the response.

[0032] In a ninth aspect, there is provided yet another communication system that can comprise a first network element and a terminal device. The first network element is configured to perform any of the methods described in the first aspect above; and the terminal device is configured to receive address information of edge application servers.

[0033] For example, the first network element is configured to learn that a terminal device requests to access a first application, select a first data network access identifier and / or a first edge application server in a first data network for the terminal device, and send address information of the first edge application server to the terminal device, where the first data network access identifier is used to identify the first data network, and the first edge application server is used to support the first application; the terminal device is configured to receive the address information; and a sum of a first time delay and a second time delay is less than or equal to an access time delay threshold of the first application, the first time delay is a transmission time delay between the terminal device and a core network device corresponding to the first data network access identifier, or a transmission time delay between an access network device serving the terminal device and the core network device corresponding to the first data network access identifier, and the second time delay is a processing time delay of the first edge application server.

[0034] In a tenth aspect, a communication method is provided, which can be performed by the communication system of the ninth aspect. The method can include: a first network element learning that a terminal device requests to access a first application; the first network element selecting a first data network access identifier and / or a first edge application server in a first data network for the terminal device, where the first data network access identifier is used to identify the first data network, and the first edge application server is used to support the first application; the first network element sending address information of the first edge application server to the terminal device; the terminal device receiving the address information; and a sum of a first time delay and a second time delay being less than or equal to an access time delay threshold of the first application, the first time delay being a transmission time delay between the terminal device and a core network device corresponding to the first data network access identifier, or a transmission time delay between an access network device serving the terminal device and the core network device corresponding to the first data network access identifier, and the second time delay being a processing time delay of the first edge application server.

[0035] In an eleventh aspect, a computer readable storage medium is provided, which includes a computer program, when the computer program is run on a computing device, causes the computing device to perform the method of any one of the first aspect, the second aspect, the eighth aspect, or the tenth aspect.

[0036] In a twelfth aspect, a chip is provided, which is coupled with a memory, and is configured to read and execute program instructions stored in the memory, to implement the method of any one of the first aspect, the second aspect, the eighth aspect, or the tenth aspect.

[0037] In a thirteenth aspect, a computer program product is provided, which, when invoked by a computer, causes the computer to perform the method of any one of the first aspect, the second aspect, the eighth aspect, or the tenth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1A An illustration of selecting the nearest EAS for a UE by a network side;

[0039] Figure 1B An illustration of the corresponding latency of a UE under different service experiences;

[0040] Figure 2A And Figure 2B An illustration of two application scenarios of embodiments of the present application;

[0041] Figure 3 A flowchart of a first communication method provided by embodiments of the present application;

[0042] Figure 4 A flowchart of a second communication method provided by embodiments of the present application;

[0043] Figure 5 A flowchart of a third communication method provided by embodiments of the present application; Figure 6 A flowchart of a fourth communication method provided by embodiments of the present application;

[0044] Figure 7 A flowchart of a fifth communication method provided by embodiments of the present application; Figure 8 An illustration of an apparatus provided by embodiments of the present application;

[0045] Figure 9 An illustration of another apparatus provided by embodiments of the present application;

[0046] Figure 10 An example of the transmission latency corresponding to a DNAI in embodiments of the present application;

[0047] Figure 11 Another example of the transmission latency corresponding to a DNAI in embodiments of the present application;

[0048] Figure 12 An example of the association between the load and the processing latency of an EAS in embodiments of the present application;

[0049] Figure 13 An example of the access latency threshold applied in embodiments of the present application;

[0050] Figure 14 An example of the address information of an EAS in embodiments of the present application. DETAILED DESCRIPTION

[0051] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the following further describes the embodiments of the present application with reference to the drawings.

[0052] In the embodiments of the present application, the number of a noun, unless otherwise specified, represents "a singular noun or a plural noun", that is, "one or more". "At least one" means one or more, and "multiple" means two or more than two. "And / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone, wherein A or B can be singular or plural. The character " / " generally represents that the associated objects before and after it are in an "or" relationship. For example, A / B represents A or B. "At least one of the following" or "one or more of the following" and the like means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b, or c, or one or more of a, b, or c, represents a, b, c, a and b, a and c, b and c, or a and b and c. Each of a, b, and c can be single or multiple.

[0053] The ordinal numbers "first", "second", and the like mentioned in the embodiments of the present application are used to distinguish a plurality of objects, and are not used to limit the size, content, order, time sequence, priority, or importance of the plurality of objects. In addition, the numbering of the steps in each of the embodiments introduced in the embodiments of the present application is only used to distinguish different steps, and is not used to limit the order of the steps. For example, S501 can occur before S502, or can occur after S502, or can occur simultaneously with S502.

[0054] In the following, some terms or concepts in the embodiments of the present application are explained and described, so as to facilitate the understanding of the skilled in the art.

[0055] (1) In the embodiments of the present application, the terminal device is a device with wireless transceiving function, which can be a fixed device, a mobile device, a handheld device (for example, a mobile phone), a wearable device, a vehicle-mounted device, or a wireless device (for example, a communication module, a modem, or a chip system, etc.) built in the above devices. The terminal device is used to connect people, objects, machines, etc., and can be widely used in various scenes, for example, including but not limited to the following scenes: cellular communication, device-to-device (D2D) communication, V2X, machine-to-machine / machine-type communications (M2M / MTC), internet of things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self driving, remote medical, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, unmanned aerial vehicle, robot, etc. The terminal device can be sometimes referred to as UE, terminal, access station, UE station, remote station, wireless communication device, or user equipment, etc.

[0056] For the convenience of description, the terminal device is taken as an example of UE in the embodiments of the present application.

[0057] (2) The network device in the embodiments of the present application, for example, includes an access network device and / or a core network device. The access network device is a device with wireless transceiving function, used for communicating with the terminal device. The access network device includes, but is not limited to, a base station (base transceiver station (BTS), Node B, eNodeB / eNB, or gNodeB / gNB), a transmission reception point (TRP), a base station evolved from the 3rd generation partnership project (3GPP) in the future, an access node in a wireless fidelity (Wi-Fi) system, a wireless relay node, a wireless backhaul node, and the like. The base station can be a macro base station, a micro base station, a pico base station, a small station, a relay station, and the like. A plurality of base stations can support a network of the same access technology or a network of different access technologies. A base station can include one or more co-sited or non-co-sited transmission reception points. The access network device can also be a wireless controller, a centralized unit (CU), and / or a distributed unit (DU) in a cloud radio access network (CRAN) scenario. The access network device can also be a server and the like. For example, the network device in vehicle to everything (V2X) technology can be a road side unit (RSU). The following describes the access network device by taking a base station as an example. The base station can communicate with the terminal device or communicate with the terminal device through a relay station. The terminal device can communicate with a plurality of base stations in different access technologies. The core network device is used to implement mobile management, data processing, session management, policy and charging, and the like. The names of devices implementing core network functions in systems of different access technologies can be different, and the embodiments of the present application do not limit this. Taking the 5th generation (5G) mobile communication system as an example, the core network device includes an access and mobility management function (AMF), a session management function (SMF), a policy control function (PCF), a user plane function (UPF), and the like.

[0058] In the embodiments of the present application, the communication device for implementing the function of the network device can be a network device, or a device capable of supporting the network device to implement the function, such as a chip system, which can be installed in the network device. In the technical solutions provided in the embodiments of the present application, the device for implementing the function of the network device is taken as an example of the network device to describe the technical solutions provided in the embodiments of the present application.

[0059] The technical features related to the embodiments of the present application are introduced below.

[0060] Cloud gaming is a game mode based on cloud computing. From the principle of cloud gaming, the UE only needs to perform simple decoding output and upload player operation instructions, where the UE is not limited to personal computers (PCs), notebooks, tablet computers, mobile phones, or television boxes and the like, so that the cloud gaming greatly reduces the performance requirements of the UE, and only needs to have a certain decoding capability. In the running mode of cloud gaming, all games run in the application server, and the UE can send user commands to the application server, and the application server can compress the rendered game screen and transmit it to the UE through the network, for example, through the way of video stream transmission. Compared with traditional games, the introduction of the cloud gaming platform moves the functions of game operation and rendering to the cloud through cloud network integration, fully utilizes the advantages of large bandwidth and low latency of the 5th generation (5G) network, and improves the service perception of cloud gaming. The benefits brought by this are that the performance requirements of the UE are reduced, and the game experience is more easily and conveniently obtained.

[0061] Cloud gaming is a strong interactive service, and the delay of the service is the highest requirement for the cloud gaming solution. From the perspective of end-to-end (for example, the UE is one end and the application server is the other end), the delay of the service includes the transmission delay of data in the network and the processing delay of the application server providing the service. Among them, the transmission delay of data in the network includes, for example, the transmission delay of data between the UE and the application server; the processing delay of the application server is also called the server processing delay, or the service quality of the server. Among them, the transmission delay of data in the network is related to many complex factors such as network bandwidth, network topology, user plane path, etc.; the server processing delay (or the service quality of the server) is related to factors such as the load of the server and the graphics processing unit (GPU) capability. For reference Figure 1B For example, the delay of different service experiences of the UE is as follows, wherein, Figure 1BThe UE in the above-mentioned is, for example, a mobile phone or other UE:

[0062] In the starting stage (referred to as stage 1), the end-to-end time delay of operation response is ≤100 ms. Among them, the local processing time delay of the UE side is ≤30 ms, the data transmission time delay in the network is ≤30 ms, and the server processing time delay is ≤40 ms. At this time, the game operation delay is within the acceptable range, and the user's service experience is fair.

[0063] In the comfortable experience stage (referred to as stage 1), the end-to-end time delay of operation response is ≤70 ms. Among them, the local processing time delay of the UE side is ≤20 ms, the data transmission time delay in the network is ≤20 ms, and the server processing time delay is ≤30 ms. At this time, the game operation delay reaches the level of a quasi-electronic player, and the user's service experience is good.

[0064] In the ideal experience stage (referred to as stage 1), the end-to-end time delay of operation response is ≤50 ms. Among them, the local processing time delay of the UE side is ≤10 ms, the data transmission time delay in the network is ≤15 ms, and the server processing time delay is ≤25 ms. At this time, the game operation delay reaches the level of an electronic player, and the user's service experience is excellent.

[0065] As can be seen from the above, in order to meet the user's service experience, the server processing time delay should be guaranteed.

[0066] The server processing time delay is related to the load of the application server. If the work undertaken by the application server exceeds the amount of resources that can be supported by the application server, the response speed of the application server will decrease. The application server will undertake work even in an overload state, but will take more time for context switching, that is, the response speed will become very slow. If the application server is overloaded and its processing time delay exceeds a certain time delay limit, the request of the UE will fail. Therefore, the larger the throughput submitted to the application server, the longer the response time of the application server, and eventually the turning point of rapid deterioration is reached.

[0067] The time delay sensitive service needs to guarantee the end-to-end service time delay. For example, in order to guarantee the service experience of the UE, the total amount of end-to-end time delay needs to be optimized. The current standard clearly specifies how to discover the DN closest to the UE position for the UE, so as to provide the UE with the address of the EAS deployed by the DN, thereby reducing the data transmission time delay in the network. For example, refer to Figure 1AWhen the EAS1 is deployed in the LDN1, the EAS2 is deployed in the LDN2, and the EAS3 is deployed in the LDN3, the EAS1 to the EAS3 can support the same application. When the UE requests to access a certain application, the SMF selects the LDN1 closest to the location of the UE, and the EASDF can return the address of the EAS1 deployed in the LDN1 to the UE, and the UE can access the application supported by the EAS1 according to the address.

[0068] However, the EAS1 selected by the SMF can not provide better service quality for the UE.

[0069] Therefore, the selection of the first network element in the embodiments of the present application is more conducive to the UE to quickly access the first application, so that the UE can obtain a faster response of the EAS for the application, and the data transmission delay between the UE and the EAS supporting the application is reduced, thereby improving the access experience of the user using the UE for the service of the application.

[0070] Please refer to Figure 2A FIG. 1 is a schematic diagram of a 5G network architecture based on a service-oriented architecture, and the network architecture is also a network architecture to which the embodiments of the present application are applied. Figure 2A The illustrated 5G network architecture can include three parts, which are a UE part, a DN, and an operator network part.

[0071] The operator network can 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, an SMF network element, a (radio) access network (R)AN or a user plane function (UPF) network element, and the like.

[0072] The above operator network includes a radio access network and a core network. The UE accesses the core network through the (R)AN, and the core network includes a user plane network element and a control plane network element. The user plane network element of the core network includes a UPF, and the control plane network element of the core network includes at least one of an AUSF, an AMF, an SMF, an NSSF, an NEF, an NRF, a UDM, a PCF, or an AF.

[0073] The user plane network element (for example, the UPF) is mainly responsible for packet data forwarding, QoS control, charging information statistics, and the like. The control plane network element is mainly responsible for service process interaction, issuing packet forwarding policies and QoS control policies to the user plane, and the like. In the embodiments of the present application, it is considered that sensors and the like can access the core network through the UE and the (R)AN and the like, so that the controller connected with the sensors and the like in the industrial Ethernet can perform industrial data communication in the user plane through the UPF.

[0074] Among them, the core network control plane can adopt a service-oriented architecture, that is, the interaction between control plane network elements adopts a service call mode to replace the point-to-point communication mode in the traditional architecture. In the service-oriented architecture, a control plane network element will open services to other control plane network elements for calling by other control plane network elements; in the point-to-point communication, there will be a specific set of messages for the communication interface between the control plane network elements, which can only be used by the control plane network elements at both ends of the interface when communicating.

[0075] The functions of the network elements in the core network are introduced as follows:

[0076] The UPF performs user data packet forwarding according to the routing rules of the SMF, such as sending uplink data to a DN or other UPF, and forwarding downlink data to other UPF or (R)AN.

[0077] The AUSF performs security authentication of the UE.

[0078] The AMF performs access management and mobility management of the UE. It is responsible for maintaining the state of the UE, managing the reachability of the UE, forwarding non-mobility management (MM) non-access-stratum (NAS) messages, and forwarding session management (SM) N2 messages.

[0079] The SMF performs session management of the UE, allocates resources for the session of the UE, and releases the resources. The resources include session quality of service (QoS), session path, forwarding rule, and the like.

[0080] The NSSF selects a network slice for the UE.

[0081] NEF, which exposes network functions to third parties in the form of northbound application programming interface (API) interfaces.

[0082] NRF, which provides storage and selection functions for network function entity information for other network elements.

[0083] UDM, user subscription context management.

[0084] PCF, user policy management, which is used to generate, manage user, session, and QoS flow processing policies.

[0085] AF, application management, which is a functional network element that provides various service services and can interact with the core network through the NEF and can interact with the policy management framework for policy management.

[0086] The related interfaces between the network element functions involved in the embodiments of the present application include:

[0087] N1: interface between UE and core network control plane.

[0088] N2: communication interface between (R)AN and core network control plane.

[0089] N3: communication interface between (R)AN and UPF, used for transmitting user plane data.

[0090] N4: communication interface between SMF and UPF, used for SMF to configure policies for UPF, etc.

[0091] N6: communication port between UPF and DN.

[0092] Please refer to Figure 2B , which is another network architecture to which the embodiments of the present application are applied. Regarding Figure 2B , the network elements in the network architecture can refer to the introduction of the related network elements in Figure 2A . Figure 2B The main difference between Figure 2A is that Figure 2B , the interfaces between the network elements in are point-to-point interfaces, not service interfaces.

[0093] The method provided by the embodiments of the present application is described below with reference to the drawings. In each of the embodiments herein, an application can correspond to a service one by one, for example, one application can correspond to (or provide) one service, and a user accessing one application can obtain the service provided by the application. Alternatively, the application and the service can have other correspondence, which is not limited in the embodiments of the present application. In each of the embodiments herein, “accessing” can mean that the UE establishes a data plane link between the UE and the application (or the application server), for example, the UE can establish a PDU session with the core network, and through the PDU session, the UE can transmit data plane messages with the application. For example, the UE accessing the EAS or the application supported by the EAS can mean that the UE has accessed the EAS, or the UE is accessing the EAS, or the UE expects to access but has not accessed the EAS.

[0094] In each of the embodiments of the present application, one data network access identifier (DNAI) can identify one DN or LDN in which one or more EASs exist. The UE needs to pass through the UPF to communicate with the one or more EASs, and the UPF can be regarded as the UPF corresponding to the first DNAI. Optionally, the one or more EASs existing in one DN or LDN can mean that there is one or more EASs supporting the same application in the DN or LDN; or the one or more EASs existing in one DN or LDN can mean that the locations of the one or more EASs are in the DN or LDN, without limiting the applications supported by the one or more EASs. Generally, one DN or LDN covers a specific area, so the existence of the EAS in one DN or LDN can also be understood as the existence of the EAS in the area covered by one DN or LDN, and it can also be understood as the deployment of one or more EASs in one DN or LDN. In the following description of each of the embodiments, the DNAI identifies the DN as an example.

[0095] The embodiments herein can be applied to the network architecture shown in Figure 2A or Figure 2B For example, the session management function network element described in each of the embodiments herein can be the SMF in Figure 2A or Figure 2B The second network element described in each of the embodiments herein can be the UDR in Figure 2A or Figure 2B The EAS described in each of the embodiments herein can be located in Figure 2A or Figure 2Bthe DN in the figure; the network exposure function network element described in each embodiment of the present disclosure can be Figure 2A or Figure 2B the NEF in the figure; the AF described in each embodiment of the present disclosure can be Figure 3 or Figure 4 the AF in the figure. In the corresponding drawings of each embodiment of the present disclosure, the steps represented by dashed lines are optional steps.

[0096] The first communication method provided in the embodiments of the present disclosure is described below with reference to Figure 5 , which is a flowchart of the method.

[0097] S301, the first network element learns that a UE requests to access a first application.

[0098] The first network element is, for example, an SMF; or, the first network element can also be a newly defined network element, for example, the first network element is referred to as a new network function (network function, NF), or can also have other names. If the first network element is a newly defined network element, the first network element can be an independent network element, for example, arranged in a core network; or, the first network element can also be a function module implemented by software and / or hardware, which can be deployed in an SMF or other network element.

[0099] S302, the first network element selects a first DNAI for the UE.

[0100] The sum of the first delay and the second delay can be less than or equal to the access delay threshold of the first application. The first delay is the transmission delay between the core network device corresponding to the DNAI and the UE, or the first delay is the transmission delay between the access network device serving the UE and the core network device corresponding to the first DNAI. Optionally, the core network device is, for example, a UPF, or can also be other core network devices, and the embodiments of the present disclosure take the UPF as an example; the "transmission delay" can also be referred to as "network transmission delay", which refers to the delay of service transmission in the network.

[0101] For example, the first delay can be included in the transmission delay corresponding to the first DNAI. The transmission delay corresponding to one DNAI can be understood as any one of case 1 or case 2. The core network device corresponding to the first DNAI is, for example, the UPF corresponding to the first DNAI.

[0102] Case 1: The transmission delay corresponding to one DNAI is the transmission delay between the UE and the DNAI. For example, the transmission delay between the UE and the DNAI includes delay A, which is the transmission delay between the UPF corresponding to the DNAI and the UE. For example, the transmission delay between the UPF and the UE refers to the delay of the user plane transmission path between the UPF and the UE. For example, delay A includes the delay of the user plane transmission path of the N3 interface between the UPF corresponding to the DNAI and the RAN, and the delay of the user plane transmission path of the air interface link between the RAN and the UE, where the RAN serves the UE. That is, optionally, the transmission delay corresponding to the DNAI can satisfy the following relationship:

[0103] Transmission delay corresponding to the DNAI = air interface transmission delay + N3 interface transmission delay (Formula 1)

[0104] Optionally, in case 1, the transmission delay between the UE and the DNAI can include delay B in addition to delay A, where delay B includes the transmission delay of the N6 interface between the UPF and the EAS in the DN identified by the DNAI. That is, the transmission delay corresponding to the DNAI can satisfy the following relationship:

[0105] Transmission delay corresponding to the DNAI = air interface transmission delay + N3 interface transmission delay + N6 interface transmission delay (Formula 2)

[0106] In general, in actual scenarios, if there is an EAS in the DN identified by a certain DNAI, and the DN has a UPF, the distance between the UPF and the EAS can be relatively short, so delay B can be ignored. That is, optionally, in case 1, the transmission delay corresponding to the DNAI can satisfy the relationship shown in Formula 1.

[0107] If the transmission delay corresponding to the first DNAI is implemented in case 1, the first delay is, for example, the delay A corresponding to the first DNAI, that is, the transmission delay between the UPF corresponding to the first DNAI and the UE.

[0108] Case 2: The transmission delay corresponding to one DNAI is the transmission delay between the RAN serving the UE and the DNAI. For example, the transmission delay between the RAN and the DNAI includes delay C, which is the delay of the user plane transmission path of the N3 interface between the UPF corresponding to the DNAI and the RAN. That is, the transmission delay corresponding to the DNAI can satisfy the following relationship:

[0109] Transmission delay corresponding to the DNAI = N3 interface transmission delay (Formula 3)

[0110] Optionally, in case 2, the transmission delay between the RAN and the DNAI can include the delay B in addition to the delay C. As described before, the delay B is the transmission delay of the N6 interface between the UPF and the EAS within the DN identified by the DNAI. That is, the transmission delay corresponding to the DNAI can satisfy the following relationship:

[0111] Transmission delay corresponding to the DNAI = N3 interface transmission delay + N6 interface transmission delay (Formula 4)

[0112] As described before, generally, the delay B can be ignored. That is, optionally, in case 2, the transmission delay corresponding to the DNAI can satisfy the relationship shown in Formula 3.

[0113] If the transmission delay corresponding to the first DNAI is implemented in case 2, the first delay is, for example, the delay C corresponding to the first DNAI, that is, the transmission delay between the UPF corresponding to the first DNAI and the RAN serving the UE.

[0114] Take case 1 as an example. The delay of the user plane transmission path between the UE and the UPF corresponding to the DNAI can be independent of the application accessed by the UE. One DNAI can correspond to one or more UPFs, and the transmission delay corresponding to the DNAI can include the transmission delay between the UE and each of the one or more UPFs corresponding to the DNAI. That is, one DNAI can correspond to one or more transmission delays. One transmission delay can include uplink transmission delay and / or downlink transmission delay.

[0115] For example, a certain DNAI in the network corresponds to UPF1 and UPF2, and the transmission delay corresponding to the DNAI can include one or more of the following: the transmission delay T1 between the UE and UPF1 (including uplink transmission delay and / or downlink transmission delay), or the transmission delay T2 between the UE and UPF2 (including uplink transmission delay and / or downlink transmission delay).

[0116] The second delay is the processing delay of the EAS within the DN identified by the first DNAI, which is used to support the first application. The processing delays of different EASs can be the same or different. The processing delay of the EAS can be understood as the internal processing delay of the EAS.

[0117] According to the foregoing introduction, for case 1, the transmission delay corresponding to the DNAI can include the delay B in addition to the delay A; for case 2, the transmission delay corresponding to the DNAI can include the delay B in addition to the delay C. Therefore, optionally, when selecting the DNAI, the first network element can consider the delay A or the delay C, and not consider the delay B; or, when selecting the DNAI, the first network element can consider the delay A or the delay C, and also consider the delay B. For example, the first DNAI selected by the SMF can satisfy that the sum of the first delay, the second delay, and a third delay is less than or equal to the access delay threshold of the first application, where the third delay is, for example, the delay B corresponding to the first DNAI. That is, the third delay is the transmission delay of the N6 interface between the UPF and the EAS in the DN (for example, the first DN) identified by the first DNAI.

[0118] When selecting the DNAI for the UE, the first network element in the embodiment of the present application considers both the transmission delay between the UE and the UPF corresponding to the DNAI and the processing delay of the EAS, so that the selected first DNAI is more conducive to fast access of the UE to the first application, thereby enabling the UE to obtain a faster response of the EAS for the application, and being conducive to reducing the data transmission delay between the UE and the EAS supporting the application, thereby improving the access experience of a user using the UE for the service of the application.

[0119] The embodiment of the present application provides a second communication method, please refer to Figure 3 , which is a flowchart of the method.

[0120] S401, the first network element sends a first request to the second network element. Correspondingly, the second network element receives the first request from the first network element. The first request can be used to request to obtain the processing delay of the EAS in the DN.

[0121] For example, the first network element can select the DNAI for the UE according to the processing delay of the EAS in the DN. If the first network element does not store the information for determining the processing delay of the EAS, the first network element can obtain the processing delay of the EAS in the DN through the first request.

[0122] S402, the second network element sends a response to the first request to the first network element. Correspondingly, the first network element receives the response from the second network element. The response can include the processing delays of N EASs in at least one DN, where N is a positive integer. The at least one DN is identified by at least one DNAI, and one DNAI can identify one DN. There can be one or more EASs in one DN, and the N EASs are, for example, part or all of the EASs in the at least one DN.

[0123] For example, the first request can include at least one DNAI, and the second network element provides the processing delay of the EAS in the at least one DN identified by the at least one DNAI to the first network element; or the first request can not include at least one DNAI, and the second network element determines the at least one DNAI according to the first request, and provides the processing delay of the EAS in the at least one DN identified by the at least one DNAI to the first network element.

[0124] For example, the first network element knows the processing delay of the N EASs, and can select a DNAI for the UE according to the processing delay of the N EASs. In this way, the first DNAI selected by the first network element is more conducive to the UE to quickly access the first application, so that the UE can obtain a faster response of the EAS for the access to the application, and the data transmission delay between the UE and the EAS supporting the application is reduced, thereby improving the access experience of a user using the UE for the service of the application.

[0125] The third communication method is provided in the embodiments of the present application, please refer to Figure 4 , which is a flowchart of the method. The method can be regarded as an example of the method shown in Figure 5 and the method shown in Figure 3 .

[0126] S501, the SMF obtains the transmission delay (or the delay A or the delay C) corresponding to each of the K DNAIs. Figure 10 Taking the transmission delay as an example) of each of the K DNAIs. K is a positive integer. The transmission delay corresponding to one DNAI can include the delay A or the delay C corresponding to the DNAI, which can be referred to the introduction of the embodiment shown in Figure 11 .

[0127] Optionally, the SMF can obtain the transmission delay or the delay A or the delay C corresponding to each of the K DNAIs through a quality of service (QoS) monitoring mechanism. In the network, a data packet can be set with a time stamp when it is transmitted, for example, when a data packet is sent from a network element, the network element adds a sending time stamp to the data packet; when the data packet arrives at another network element, the other network element adds an arrival time stamp to the data packet. In this way, the time stamp of the data packet can determine the user plane transmission path delay between the UE (or the RAN) and the UPF corresponding to different DNAIs, that is, the delay A or the delay C corresponding to different DNAIs. Optionally, the transmission delay of the N6 interface between the UPF and the EAS in the DN identified by different DNAIs can also be determined through the time stamp of the data packet, and in combination with the delay A or the delay C, the SMF can determine the transmission delay corresponding to each of the K DNAIs.

[0128] Alternatively, the network management system can obtain the transmission delay corresponding to each of the K DNAIs or the delay A or the delay C. The network management system can configure the obtained transmission delay corresponding to each of the K DNAIs or the delay A or the delay C to the SMF, and then the SMF can obtain the transmission delay corresponding to each of the K DNAIs or the delay A or the delay C.

[0129] For example, if there is only one UPF supporting each DNAI in the network (i.e., there is only one UPF corresponding to the DNAI), the transmission delay corresponding to the DNAI can refer to Table 1-1 shown as follows. Figure 12 For example, the transmission delay corresponding to the K DNAIs obtained by the SMF can include one or more of Table 1-1. Wherein, one row in Table 1-1 represents the transmission delay corresponding to one DNAI, and thus one row in Table 1-1 is regarded as one item.

[0130] For another example, if there can be multiple UPFs supporting one DNAI in the network (i.e., there are multiple UPFs corresponding to the DNAI), the transmission delay corresponding to the DNAI can refer to Table 1-2 shown as follows. Figure 13 For example, the transmission delay corresponding to the K DNAIs obtained by the SMF can include one or more of Table 1-2. Wherein, one row in Table 1-2 represents one transmission delay corresponding to one DNAI, and thus one row in Table 1-2 is regarded as one item.

[0131] In S502a, the AF sends third information and first information to the NEF, and correspondingly, the NEF receives the third information and the first information from the AF. The NEF sends the third information and the first information to the second network element, and correspondingly, the second network element receives the third information and the first information from the NEF. In this embodiment of the present application, the second network element is taken as an example of the UDR. Wherein, the NEF sends the third information and the first information to the UDR, and this step can also be understood as that the NEF stores the third information and the first information in the UDR. In each embodiment of the present application, the third information can also have other names, for example, it can also be called association information, and the following will not be described in detail.

[0132] The third information can indicate the association between the load and the processing delay of the EAS in the DN identified by the M DNAIs. Optionally, the association between A and B can be understood as the association relationship or the corresponding relationship between A and B. M is a positive integer. Optionally, the third information can also indicate the application supported by the EAS, for example, the third information includes the identifier of the application supported by the EAS. Please refer to Figure 2AThe third information includes one or more items in Table 2 as shown in Table 2. One row in Table 2 is regarded as one item. "DNAI" in Table 2 is used to identify a DN, for example, one-to-one correspondence between DNAI and DN. "Number of accessed users" in Table 2 represents the number of access users of the EAS, which can be understood as the load of the EAS. The access users of the EAS can include a UE that has accessed the EAS and requests to access an application supported (or provided) by the EAS.

[0133] FQDN in Table 2 represents the fully qualified domain name (FQDN) of an application. For example, the identifier of the application can include the FQDN of the application, which is not limited in the embodiments of the present application. According to Table 2, the application supporting FQDN#1 is located in EAS1 of DNAI#1 and EAS2 of DNAI#2. The number of users that can be accommodated by the two EASs can be different due to the performance of general process unit (GPU) or other reasons. EAS1 of DNAI#1 can handle the maximum number of access users of user number#1 without performance degradation, that is, as long as the number of access users of EAS1 is less than user number#1, the processing delay of EAS1 can be guaranteed to be T1. If the number of access users of EAS1 increases, the performance of EAS1 decreases. However, as long as the number of access users accessing EAS1 is less than user number#2, the processing delay of EAS1 can be guaranteed to be T2. It can be seen from Table 2 that T2 is greater than T1. In addition, EAS1 can support other applications in addition to the application supporting FQDN#1, which is not indicated one by one in Table 2.

[0134] Similarly, EAS2 of DNAI#2 can handle the maximum number of access users of user number#3 without performance degradation. As long as the number of access users of EAS2 is less than user number#3, the processing delay of EAS2 can be guaranteed to be T3. If the number of access users of EAS2 increases, the performance of EAS2 decreases. However, as long as the number of access users of EAS2 is less than user number#4, the processing delay of EAS1 can be guaranteed to be T4. It can be seen from Table 2 that T4 is greater than T3. In addition, EAS2 can support other applications in addition to the application supporting FQDN#1, which is not indicated one by one in Table 2.

[0135] The first information can indicate an access latency threshold of the first application, where the access latency threshold can be understood as a latency requirement to be met for accessing the first application. For example, the first information can indicate an access latency threshold of at least one application, where the at least one application includes the first application. The access latency threshold of an application, for example, is an end-to-end access latency threshold of the application, where "end-to-end" refers to a UE end to an EAS end that supports (or, provides) the application. That is, the access latency threshold of an application can be a threshold to be met for a latency between a UE accessing the application and an EAS supporting the application. When a UE accesses an application supported by an EAS, if a latency between the UE and the EAS is less than or equal to the access latency threshold of the application, the UE can obtain a better quality of service. Therefore, one application of the access latency threshold of an application is that a transmission latency corresponding to a DNAI (or, a latency A or a latency C corresponding to the DNAI) and a processing latency of an EAS in a DN identified by the DNAI that supports the application are less than or equal to the access latency threshold of the application. Alternatively, embodiments of the present application consider that the EASs in the DN identified by one DNAI can all support the same application. For example, referring to Table 3 shown in Figure 2A The first information can include one or more of Table 3. One row in Table 3 represents an access latency threshold of an application, and thus one row in Table 3 is considered as one item.

[0136] S502b, the UDR sends the first information to the SMF. Correspondingly, the SMF receives the first information from the UDR.

[0137] S503, the UE sends a session establishment request message to the SMF. Correspondingly, the SMF receives the session establishment request message from the UE. The session establishment request message can be used for the UE to establish a session with the SMF, where the session is, for example, a protocol data unit (PDU) session. For example, the UE requests to access the first application, and the UE can request to establish a PDU session with the SMF to transmit data corresponding to the first application.

[0138] S504, the SMF sends a first creation request message to the EASDF. Correspondingly, the EASDF receives the first creation request message from the SMF.

[0139] After receiving the session establishment request message, the SMF can select the EASDF and send the first creation request message to the EASDF. For example, for Figure 2AAs shown in the network architecture, the SMF can invoke a serviceized operation of the EASDF to implement the first creation request message, which is referred to as a first serviceized operation for example. The first serviceized operation can be used for the SMF to send a request to the EASDF. The first serviceized operation can include a DNS handling rule, which includes a context of the UE for example. Accordingly, the EASDF can receive the first serviceized operation. For example, the first serviceized operation is Neasdf_DNSContext_Create_Request.

[0140] S505, the EASDF sends a first creation response to the SMF. Accordingly, the SMF receives the first creation response from the EASDF.

[0141] After the EASDF receives the first creation request message, the EASDF can send a first creation response to the SMF. For example, the first creation response is Neasdf_DNSContext_Create_Response. Figure 3 As shown in the network architecture, the EASDF can invoke a serviceized operation of the EASDF to implement the first creation response, which is referred to as a second serviceized operation for example. The second serviceized operation can be used for the EASDF to send a response to the SMF. For example, the second serviceized operation can be a response to the first serviceized operation. For example, the second serviceized operation is Neasdf_DNSContext_Create_Response.

[0142] S506, the SMF sends a session establishment accept message to the UE. Accordingly, the UE receives the session establishment accept message from the SMF.

[0143] After the SMF receives the first creation response, the SMF can send a session establishment accept message to the UE. The session establishment accept message can indicate that the PDU session establishment is successful. The session establishment accept message can include address information of the DNS server, for example, the address information of the DNS server included in the session establishment accept message is the address information of the EASDF.

[0144] S507, the UE sends a DNS query request to the EASDF. Accordingly, the EASDF receives the DNS query request from the UE.

[0145] For example, the UE can send the DNS query request to the EASDF according to the address information of the EASDF. The DNS query request can include an identifier of the first application.

[0146] S508, the EASDF sends fifth information to the first network element. Accordingly, the first network element receives the fifth information from the EASDF. In the embodiments of the present application, the first network element is the SMF for example, and the SMF is taken as an example hereinafter.

[0147] The fifth information can indicate an application that the UE requests to access, so that the SMF can determine the application that the UE requests to access according to the fifth information. For example, the fifth information includes an identifier of the first application, to indicate that the UE requests to access the first application. The SMF can determine that the UE requests to access the first application according to the identifier of the first application. For example, the identifier of the first application is an FQDN of the first application. For example, after the EASDF receives the DNS query request, the EASDF can determine whether to send the identifier of the first application to the SMF according to the identifier of the first application and a DNS processing rule. Embodiments of the present application take an example in which the EASDF sends the identifier of the first application to the SMF.

[0148] For example, as shown in the network architecture, Figure 4 For example, the EASDF can invoke a service operation of the EASDF to send the fifth information. The service operation is referred to as a third service operation for example. The third service operation can be used for the EASDF to send a request to the SMF. The third service operation can include the first information. Correspondingly, the SMF can receive the third service operation. For example, the third service operation is Neasdf_DNSContext_Notify_Request.

[0149] After the SMF receives the fifth information, the SMF can know that the UE requests to access the first application. Therefore, S508 is the same as Figure 4 S301 in the embodiment shown in

[0150] After the SMF knows that the UE requests to access the first application, the SMF can select a DNAI for the first application (or for the UE).

[0151] S509, the SMF determines processing delays of N EASs in at least one DN. N is a positive integer. The at least one DN is identified by at least one DNAI. One DNAI can identify one DN, and therefore at least one DNAI can identify at least one DN. There can be one or more EASs in one DN, and the N EASs are all or part of the EASs in the at least one DN for example.

[0152] The SMF can determine the DNAI that the UE can access according to the location where the UE is located (wherein the UE accessing the DNAI can be understood as the UE accessing the application supported by the EAS in the DN identified by the DNAI). For example, the SMF determines a list of DNAIs that the UE can access based on the location where the UE is located, and the list of DNAIs contains at least one DNAI, that is, the at least one DNAI is the DNAI that the UE can access. The at least one DNAI can include all or part of the K DNAIs described in S501. There can be one or more EASs in the DN identified by any DNAI in the at least one DNAI, and the number of EASs present in the DN identified by different DNAIs can be the same or different.

[0153] Optionally, in addition to considering the location of the UE, the SMF can also consider whether the EAS in the DN identified by the DNAI supports the first application when determining the at least one DNAI. For example, the SMF determines that there are multiple DNAIs that the UE can access, and the SMF determines the DNAI from the multiple DNAIs, wherein the EAS in the DN identified by the DNAI supports the first application, for example, the at least one DNAI. Alternatively, the SMF determines that the EAS in the DN identified by the multiple DNAIs all supports the first application, and then the SMF determines the DNAI that the UE can access according to the location of the UE from the multiple DNAIs, for example, the at least one DNAI. In the embodiments of the present application, the EAS in the DN identified by each DNAI in the at least one DNAI can support the same application.

[0154] After determining the at least one DNAI, the SMF can further determine the processing delay of the EAS in the at least one DN identified by the at least one DNAI to determine which DNAI to select for the UE. Optionally, the SMF can obtain the processing delay of the N EASs in the at least one DN from the UDR. For example, S509 can include S509a and S509b.

[0155] S509a, the SMF sends a first request to the UDR. Correspondingly, the UDR receives the first request from the SMF.

[0156] The first request can be used to request to obtain the processing latency of the EAS in the DN. Optionally, the first request can include one or more of the following: an identity of the UE, an identity of the first application, or at least one DNAI. For example, the identity of the UE can include a subscription permanent identifier (SUPI) of the UE. For example, the first request includes the identity of the UE, the UDR can query the application corresponding to the UE according to the identity of the UE. The application corresponding to the UE includes, for example, the application that the UE has historically accessed, or the application that has a binding relationship with the UE, and the like. For example, the UDR queries to determine that the UE corresponds to one or more applications, and the processing latency of the EAS supporting the one or more applications can be determined respectively. In this case, the UDR can determine the processing latency of part or all of the EAS in at least one DN, and can also determine the processing latency of the EAS in the DN other than the at least one DN.

[0157] Alternatively, the first request includes the identity of the first application, and the UDR can determine the processing latency of the EAS supporting the first application. In this case, the UDR can determine the processing latency of part or all of the EAS in at least one DN, and can also determine the processing latency of the EAS in the DN other than the at least one DN.

[0158] Alternatively, the first request includes the at least one DNAI, and the UDR can directly determine the processing latency of part or all of the EAS in the at least one DN.

[0159] Alternatively, the first request includes the identity of the UE and the at least one DNAI, and the UDR can query one or more applications corresponding to the UE according to the identity of the UE, and determine the EAS supporting the one or more applications. Further, the UDR selects the EAS in the at least one DN from the EAS, and the UDR selected, for example, part or all of the EAS in the at least one DN, and the UDR can determine the processing latency of the selected EAS.

[0160] Alternatively, the first request includes the identity of the first application and the at least one DNAI, and the UDR can determine the EAS supporting the first application, and select the EAS in the at least one DN from the EAS. The UDR selected, for example, part or all of the EAS in the at least one DN, and the UDR can determine the processing latency of the selected EAS.

[0161] It can be seen that if the first request includes the at least one DNAI, the DNAI queried by the UDR can be the DNAI that the UE can access, which can improve the effectiveness of the information obtained by the SMF, and also can reduce the query range of the UDR; and if the first request does not include the at least one DNAI, the transmission overhead between the SMF and the UDR can be reduced.

[0162] S509a is an optional implementation of S401. Figure 3 S401 in the embodiments shown is, for example, a same step. Alternatively, S509a is an optional implementation of S401.

[0163] S509b, the UDR sends a response to the first request to the SMF. Correspondingly, the SMF receives the response from the UDR. The response can include the processing delay of the N EASs in the at least one DN.

[0164] The UDR can store the third information. The manner in which the UDR obtains the third information and the content of the third information can refer to S502a. The UDR can determine the processing delay of the N EASs in the at least one DN according to the third information and the fourth information. In various embodiments of the present application, the fourth information can also have other names, such as user information, and the like, which will not be described below. The fourth information can include the number of access users of the N EASs. It can be understood that the fourth information includes the number of access users of the N EASs, and the third information indicates the association between the load (for example, the number of access users of the EAS) of the EAS and the processing delay of the EAS, so that the UDR can determine the processing delay corresponding to the fourth information from the third information.

[0165] As introduced above, one or more EASs can exist in one DN, and embodiments of the present application take an example that EASs in one DN can support the same application, and embodiments of the present application also take an example that the performance of EASs in one DN is the same or similar. Therefore, in embodiments of the present application, the processing delay of EASs in one DN can include the processing delay of any EAS in the DN. Alternatively, since embodiments of the present application consider that the processing delay of all EASs in one DN is equal, it can also be considered that the processing delay of EASs in one DN can include the processing delay of all EASs in the DN, but the processing delay of all EASs is equal. For example, at least one DN includes a second DN, and there are E EASs in the second DN, then the processing delay of the E EASs in the second DN can include the processing delay of any one of the E EASs, or can include the processing delay of all the E EASs, but the processing delay of the E EASs can be equal. E is a positive integer less than or equal to N, and the second DN can be any one of the at least one DN. In this case, the processing delay of the N EASs in the at least one DN determined by the UDR can include the processing delay of part of the N EASs, and the part of the N EASs can correspond to the at least one DN one by one, for example, the number of the part of the N EASs is equal to the number of the at least one DN AI, and the correspondence between the EAS and the DN is, for example, that the DN includes the EAS; or the processing delay of the N EASs in the at least one DN determined by the UDR can include the processing delay of all the N EASs, but the processing delay of all the N EASs can be equal.

[0166] For example, the number of the at least one DN AI is 3, the 3 DN AIs identify 3 DNs, and there are 7 EASs in the 3 DNs (for example, EAS1 and EAS2 exist in the DN identified by DN AI#1, EAS3, EAS4 and EAS5 exist in the DN identified by DN AI#2, and EAS6 and EAS7 exist in the DN identified by DN AI#3). Then, the processing delay of the 7 EASs in the 3 DNs can include the processing delay of 3 EASs in the 7 EASs, and the 3 EASs correspond to the 3 DN AIs one by one. For example, the 3 EASs are EAS1, EAS4 and EAS6 respectively. Alternatively, the processing delay of the 7 EASs in the 3 DNs can include the processing delay of the 7 EASs, but the processing delay of EAS1 and EAS2 is equal, the processing delay of EAS3, EAS4 and EAS5 is equal, and the processing delay of EAS6 and EAS7 is equal. For the UDR, if there are multiple EASs in the DN identified by a certain DN AI, the UDR only needs to determine the processing delay of any one of the multiple EASs, which helps to simplify the determination process of the UDR.

[0167] For example, the first request in S509a includes an identity of the first application as FQDN#1, and the first request includes a DNAI list including at least one DNAI, the at least one DNAI including DNAI#1 and DNAI#2. According to Table 2, EAS1 in the DN identified by DNAI#1 and EAS2 in the DN identified by DNAI#2 support the first application, then the UDR can determine the load of EAS1 and EAS2, i.e., determine the number of access users of EAS1 and the number of access users of EAS2. Optionally, the UDR can adjust the number of access users of the corresponding EAS according to the increase or decrease of the access users, thus the number of access users of the EAS determined by the UDR is the current number of users accessing the EAS. The process of the UDR adjusting the number of access users of the EAS will be described later.

[0168] After the UDR determines the number of access users of EAS1 and the number of access users of EAS2, the UDR can determine the processing delay of EAS1 and the processing delay of EAS1 in combination with the third information. For example, the UDR determines that the number of access users of EAS1 is 400 (at this time, the UE has not been counted), and according to Table 2, the number of access users of EAS1 is less than the user number #1 in Table 2, indicating that the performance of EAS1 has not decreased, and the processing delay of EAS1 is T1 (20ms). For another example, the UDR determines that the number of access users of EAS2 is 700 (at this time, the UE has not been counted), and according to Table 2, the number of access users of EAS1 is greater than the user number #3 in Table 2 and less than the user number #4 in Table 2, indicating that the performance of EAS2 has decreased, and the processing delay of EAS2 is T4 (40ms).

[0169] After determining the processing delays of the N EASs, S509b can be performed, and the UDR can indicate the processing delays of the N EASs to the SMF. Continuing the above example, the response in S509b can indicate that the processing delay of EAS1 is 20ms, and the processing delay of EAS2 is 40ms.

[0170] S509b is an optional implementation of S402. Figure 2A S402 in the embodiment shown in FIG. 4 is, for example, the same step. Alternatively, S509b is an optional implementation of S402.

[0171] S510, the SMF selects a first DNAI for the UE, the first DNAI identifying that an EAS within a DN identified by the first DNAI supports the first application. For example, the SMF selects the first DNAI from the at least one DNAI, and the UE can access the first application supported by the EAS within the DN identified by the first DNAI to obtain a service corresponding to the first application. A sum of the first latency and the second latency can be less than or equal to an access latency threshold of the first application. Alternatively, a sum of the first latency, the second latency, and the third latency can be less than or equal to the access latency threshold of the first application. S510 is, for example, the same step as S302 in the embodiment shown in FIG. 3, or alternatively, S510 is an optional implementation of S302. Therefore, the introduction of the concepts of the first latency, the second latency, and the third latency can refer to S302. Figure 6 S302 in the embodiment shown in FIG. 3, or alternatively, S510 is an optional implementation of S302. Therefore, the introduction of the concepts of the first latency, the second latency, and the third latency can refer to S302.

[0172] Alternatively, in S510, the SMF can select the first DNAI for the UE from the at least one DNAI according to the processing latency of the N EASs, the latency A or the latency C or the transmission latency corresponding to the at least one DNAI, and the access latency threshold of the first application.

[0173] In S501, the SMF obtains the latency A or the latency C or the transmission latency corresponding to each of the K DNAIs, for example, the K DNAIs including the at least one DNAI. In S502b, the SMF obtains the third information, that is, obtains the access latency threshold of the first application. In S509, the SMF determines the processing latency of the N EASs. Based on the above, the SMF can select a DNAI for the UE from the at least one DNAI according to the processing latency of the N EASs, the latency A or the latency C or the transmission latency corresponding to the at least one DNAI, and the access latency threshold of the first application. The selected DNAI can be referred to as a selected DNAI. For example, the SMF selects the first DNAI, and the first DNAI can be referred to as the selected DNAI. For example, the SMF can determine a sum of the latency A or the latency C or the transmission latency corresponding to each of the at least one DNAI and the processing latency of any EAS within the DN identified by the each of the at least one DNAI, and a total of at least one sum value can be determined. The SMF can determine a sum value less than or equal to the access latency threshold of the first application from the at least one sum value, and determine the DNAI corresponding to the sum value as the first DNAI. Alternatively, the sum value corresponding to the first DNAI is not only less than the access latency threshold of the first application, but also can be the minimum value in the at least one sum value. The smaller the sum value is, the smaller the latency between the UE and the EAS is, and therefore the better the quality of service obtained by the UE can be, thereby enabling the SMF to select a more optimal DNAI for the UE.

[0174] Optionally, the SMF can determine the DNAI according to the latency A or the latency C corresponding to the DNAI, and whether to use the latency A or the latency C can also be preconfigured or protocol predefined or determined by the SMF itself. For example, the SMF determines at least one sum value according to the latency A or the latency C corresponding to the DNAI, and the SMF can determine a first sum value from the at least one sum value. For example, the first sum value is the minimum value in the at least one sum value, and the first sum value corresponds to a first DNAI. If the first sum value is less than or equal to the access latency threshold of the first application, the SMF can further determine a sum value of the first sum value and a third latency, for example, referred to as sum value A. If the sum value A is also less than or equal to the access latency threshold of the first application, the SMF can finally select the first DNAI for the UE; and if the sum value A is greater than the access latency threshold of the first application, the SMF can not select the first DNAI for the UE, at which time it is considered that the selection of the DNAI fails. Alternatively, if the first sum value is greater than the access latency threshold of the first application (since the first sum value is the minimum value in the at least one sum value, the at least one sum value is greater than the access latency threshold of the first application), the SMF can not have to determine the sum value of the first sum value and the third latency, and also does not select the first DNAI for the UE, at which time it is considered that the selection of the DNAI fails.

[0175] Alternatively, whether the SMF selects the DNAI according to the latency A, the latency C or the transmission latency corresponding to the DNAI can be preconfigured, or protocol predefined, or determined by the SMF itself. For example, the preconfigured selection of the DNAI according to the transmission latency corresponding to the DNAI, and the SMF can select one DNAI from the at least one DNAI according to the processing latency of the N EASs, the transmission latency corresponding to the at least one DNAI, and the access latency threshold of the first application. For another example, the SMF is preconfigured to select the DNAI according to the latency A corresponding to the DNAI, and the SMF can select one DNAI from the at least one DNAI according to the processing latency of the N EASs, the latency A corresponding to the at least one DNAI, and the access latency threshold of the first application, without considering the latency B corresponding to the DNAI.

[0176] For example, the first application accessed by the UE is FQDN#1, and according to Table 3, the access delay threshold of the first application is 80 ms. The SMF determines that the DNAIs accessible by the UE at its current location include DNAI#1 and DNAI#2. The SMF can determine the transmission delay of DNAI#1 and the transmission delay of DNAI#2 according to S501. For example, according to Table 1-1, the transmission delay of DNAI#1 is 50 ms, and the transmission delay of DNAI#2 is 45 ms. The SMF can determine the processing delay of the EAS in the DN identified by DNAI#1 and the processing delay of the EAS in the DN identified by DNAI#2 according to the response from the UDR in S509b. For example, the processing delay of EAS1 is 20 ms, and the processing delay of EAS2 is 40 ms. The SMF can determine the selected DNAI according to the above information. For example, the sum of the transmission delay of DNAI#1 and the processing delay of EAS1 is 70 ms, the sum of the transmission delay of DNAI#2 and the processing delay of EAS2 is 85 ms, and the access delay threshold of the first application is 80 ms. The SMF can determine that DNAI#1 can meet the access delay threshold of the first application, and DNAI#2 cannot meet the access delay threshold of the first application. Therefore, the SMF can determine that DNAI#1 is the selected DNAI.

[0177] As described above, the sum of at least one of the values determined by the SMF can be greater than the access delay threshold of the first application, or the sum of the first value corresponding to the first DNAI and the third delay can be greater than the access delay threshold of the first application. In this case, none of the at least one DNAI can meet the access delay threshold of the first application. In this case, the SMF can not select a DNAI for the UE, i.e., the process of selecting a DNAI fails, and the access of the UE also fails. Alternatively, the SMF can select a DNAI for the UE from the at least one DNAI, for example, the SMF selects the DNAI corresponding to the first sum value. Although the DNAI cannot meet the access delay threshold of the first application, the access success rate of the UE can be improved as much as possible.

[0178] Optionally, the end-to-end delay between the UE and the EAS in the DN identified by the DNAI can include the response time of the UPF in addition to the transmission delay corresponding to the DNAI and the processing delay of the EAS. The various embodiments of the present application assume that the response time of the UPF remains unchanged, and the response times of different UPFs are the same or have small differences, so the response time of the UPF can be ignored when selecting the DNAI.

[0179] Therefore, since the SMF in this embodiment of the application considers both the transmission latency of the DNAI and the processing latency of the EAS when selecting the DNAI, the latency between the DNAI selected by the SMF and the UE can be reduced, thereby enabling the UE to respond to access faster, resulting in better service quality for the UE and improving the service experience for users using the UE.

[0180] S511, SMF sends the extension mechanisms for DNS client subnet (ECS) option to EASDF. EASDF then receives this ECS option from SMF.

[0181] by Figure 3 Taking the network architecture shown as an example, the SMF can invoke an EASDF service operation to send an EAS option, which is, for example, referred to as the fourth service operation. The fourth service operation can be used by the SMF to send a response to the EASDF. For example, the fourth service operation can be a response to the third service operation described in S508. The fourth service operation can include the ECS option. Correspondingly, the EASDF can receive the fourth service operation. For example, the fourth service operation is Neasdf_DNSContext_Notify_Response.

[0182] In this scenario, the SMF expects to send the first DNAI to the DNS server via EASDF, but the DNS server may not recognize the first DNAI. Therefore, the SMF can determine the ECS option based on the first DNAI. This ECS option can indicate the first DNAI and is recognized by the DNS server.

[0183] After receiving the ECS option, the EASDF can add the ECS option to a DNS query message and send the DNS query message to a DNS server. After receiving the ECS option, the DNS server can determine a certain EAS in the DN identified by the first DNAI. For example, the DNS server determines the first EAS, and the DNS server can send address information of the first EAS, such as an internet protocol (IP) address of the first EAS, to the EASDF. In an embodiment of the present application, each EAS in the DN identified by one DNAI supports the same application, and each EAS in the DN identified by one DNAI has the same or similar performance. Therefore, the first EAS selected by the DNS server can meet the access latency threshold of the first application. That is, the sum of the first latency and the second latency can be less than or equal to the access latency threshold of the first application; or alternatively, the sum of the first latency, the second latency, and the third latency can be less than or equal to the access latency threshold of the first application.

[0184] S512, the SMF selects an uplink classifier (ULCL) / branching point (BP) and a local PDU session anchor (PSA) according to the first DNAI. S512 may, for example, occur before S511 or after S511, and no limitation is made in this regard.

[0185] In this case, the SMF selects the ULCL or the BP according to the first DNAI, so that when the UE subsequently accesses an EAS in the DN identified by the first DNAI, the sum of the transmission latency corresponding to the first DNAI and the processing latency of the EAS can be optimized.

[0186] S513, the EASDF sends address information of the first EAS to the UE, and correspondingly, the UE receives the address information from the EASDF.

[0187] For example, the EASDF determines the first EAS in the DN identified by the first DNAI, and the EASDF can send a DNS response to the UE, and the DNS response can include address information of the first EAS, such as an IP address. S513 may, for example, occur before S512 or after S512, and no limitation is made in this regard.

[0188] Optionally, the EASDF can further send address information of the first EAS to the SMF, and the SMF can receive the address information of the first EAS. This step can occur after S511. In addition, this step can occur before S513, or after S513, or simultaneously with S513.

[0189] Through the above process, the number of access users of the first EAS increases (i.e., the UE is added). In order to enable the UDR to more accurately determine the processing delay of the first EAS, the method can further include S514 and S515.

[0190] S514, the SMF sends a second request to the UDR. Correspondingly, the UDR receives the second request from the SMF.

[0191] The second request can indicate that the number of access users of the first EAS in the DN identified by the first DNAI changes. Therefore, S514 can also be understood as that the SMF notifies the UDR that the number of access users of the first EAS in the DN identified by the first DNAI changes. Wherein, the change can be an increase or a decrease. In S514, the change refers to an increase, and therefore the second request can specifically indicate that the number of access users of the first EAS in the DN identified by the first DNAI increases. Alternatively, the second request can also be used to instruct the UDR to increase the number of access users of the first EAS in the DN identified by the first DNAI. For example, the second request can include first indication information, which is used to instruct the UDR to increase the number of access users of the first EAS in the DN identified by the first DNAI, or to indicate that the number of access users of the first EAS in the DN identified by the first DNAI increases. Optionally, the second request can further include the address information of the first EAS and the first DNAI, so that the UDR is clear that the second request is for the first EAS in the DN identified by the first DNAI. Optionally, the second request can further include the identity of the UE and / or the identity of the first application. For example, the identity of the UE can include the SUPI of the UE; and the identity of the first application can include the FQDN corresponding to the first application.

[0192] S515, the UDR updates the number of access users of the first EAS. For example, in S515, the UDR can increase the number of access users of the first EAS by 1.

[0193] The first EAS whose access user number is to be increased by the UDR, e.g. related to the number of UE identities included in the second request. For example, the second request includes C1 UE identities, then the UDR can increase the access user number of the first EAS by C1, embodiments of the present application take C1 = 1 as an example. For example, the first DNAI is DNAI#1, and the first EAS is EAS1 in the DN identified by DNAI#1. In the example of S509b, the UDR determines that the access user number of EAS1 is 400. Then by performing S515, the UDR updates the access user number of EAS1 recorded by it to 401.

[0194] Alternatively, the second request can also not include the identity of the UE, then the UDR can increase the access user number of the first EAS by 1 by default.

[0195] According to the foregoing, the second request can indicate that the access user number of the first EAS in the DN identified by the first DNAI changes, and the change can be an increase or a decrease. For example, the session between the UE and the SMF is released, then the UE is disconnected from the EAS, at this time the access user number of the first EAS will decrease. Therefore, optionally, the method can further include S516 to S518.

[0196] S516, the SMF releases the session with the UE. The session is for example the session established through steps such as S503 and S506. After releasing the session, the UE is disconnected from the first EAS.

[0197] S517, the SMF sends a third request to the UDR. Correspondingly, the UDR receives the third request from the SMF.

[0198] The third request can indicate that the number of access users of the first EAS in the DN identified by the first DNAI changes. Therefore, S517 can also be understood as that the SMF notifies the UDR that the number of access users of the first EAS in the DN identified by the first DNAI changes. Wherein, the change can be an increase or a decrease, and in S517, the change refers to a decrease. Therefore, the third request can specifically indicate that the number of access users of the first EAS in the DN identified by the first DNAI decreases. Alternatively, the third request can also be used to instruct the UDR to decrease the number of access users of the first EAS in the DN identified by the first DNAI. For example, the third request can include second indication information, which is used to indicate that the number of access users of the first EAS in the DN identified by the first DNAI decreases, or to instruct the UDR to decrease the number of access users of the first EAS in the DN identified by the first DNAI. Optionally, the third request can include address information of the first EAS and the first DNAI, so that the UDR knows that the third request is for the first EAS in the DN identified by the first DNAI. Optionally, the third request can also include the identity of the UE and / or the identity of the first application.

[0199] In S518, the UDR updates the number of access users of the first EAS. For example, in S518, the UDR can decrease the number of access users of the first EAS by 1.

[0200] The number of access users of the first EAS to be decreased by the UDR, for example, is related to the number of identities of the UE included in the third request. For example, the third request includes the identities of C2 UEs, and then the UDR can decrease the number of access users of the first EAS by C2. Embodiments of the present application take C2 = 1 as an example. For example, the first DNAI is DNAI#1, and the first EAS is EAS1 in the DN identified by DNAI#1. In the example of S509b, the UDR determines that the number of access users of EAS1 is 400; by performing S515, the UDR updates the number of access users of EAS1 recorded by it to 401; and by further performing S518, the UDR updates the number of access users of EAS1 recorded by it to 400.

[0201] Alternatively, the third request can also not include the identity of the UE, and then the UDR can decrease the number of access users of the first EAS by 1 by default.

[0202] By the scheme of the embodiments of the present application, the sum of the first time delay and the second time delay is less than or equal to the access time delay threshold of the first application (or the sum of the first time delay, the second time delay and the third time delay is less than or equal to the access time delay threshold of the first application), which means that when the DNAI is selected, both the transmission time delay corresponding to the DNAI and the processing time delay of the EAS are considered, so that the selected first DNAI is more conducive to the UE to quickly access the first application, thereby enabling the UE to obtain a faster response of the EAS for the application access, and facilitating the reduction of the data transmission time delay between the UE and the EAS supporting the application, thereby improving the access experience of the user using the UE for the service of the application.

[0203] The fourth communication method provided by the embodiments of the present application is introduced below, please refer to Figure 6 , which is a flowchart of the method. The method can be regarded as an example of the embodiment shown in Figure 3 .

[0204] S601, the first network element obtains the time delay A or the time delay C or the transmission time delay (take the transmission time delay as an example) corresponding to each of the K DNAIs. Figure 5 K is a positive integer.

[0205] In the embodiments of the present application, the first network element is a newly defined network element, and the introduction thereof can be referred to the embodiment shown in Figure 5 . Among them, if the first network element is a functional module deployed in the SMF, the communication process between the first network element and the SMF in the embodiments of the present application can not be performed.

[0206] For the process of the first network element obtaining the time delay A or the time delay C or the transmission time delay corresponding to each of the K DNAIs, and the understanding of the transmission time delay corresponding to the DNAI, etc., please refer to the introduction of S501 in the embodiment shown in Figure 5 .

[0207] S602, the AF sends the third information and the first information to the NEF, and correspondingly, the NEF receives the third information and the first information from the AF. The NEF sends the third information and the first information to the second network element, and correspondingly, the second network element receives the third information and the first information from the NEF. The second network element sends the third information and the first information to the first network element. Correspondingly, the first network element receives the third information and the first information from the second network element. The embodiments of the present application take the UDR as an example. Among them, the NEF sends the third information and the first information to the UDR, and this step can also be understood as that the NEF stores the third information and the first information in the UDR.

[0208] Optionally, the first network element can pre-subscribe the EAS deployment information to the UDR. After the UDR receives the subscription information from the first network element, if the third information and / or the first information from the NEF are received, the third information and / or the first information can be sent to the first network element. For more information about S602, such as the content of the third information and the first information, etc., please refer to Figure 5 S502a and S502b of the embodiments shown.

[0209] S603, the UDR sends the third indication information to the SMF. Correspondingly, the SMF receives the third indication information from the UDR.

[0210] The third indication information can indicate which applications correspond to the access delay threshold. For example, the applications corresponding to the delay-sensitive services generally have a corresponding access delay threshold; and the applications corresponding to the non-delay-sensitive services may or may not have a corresponding access delay threshold. For the applications without a corresponding access delay threshold, it can be considered that the access delay for the applications is not limited. Therefore, the UDR can indicate to the SMF which applications correspond to the access delay threshold, and if the UE requests to access these applications, the SMF can execute the scheme of the embodiments of the present application; and if the UE requests to access the applications without a corresponding access delay threshold (for example, the applications not indicated by the third indication information), the SMF can not execute the scheme of the embodiments of the present application, for example, the SMF can select a DNAI for the UE according to the location of the UE.

[0211] The third indication information is, for example, the first information. That is, the third indication information can include the identifier of the application and the access delay threshold; or it is understood that the third indication information includes the correspondence between the identifier of the application and the access delay threshold. Or, since the SMF does not have to decide which DNAI to select for the UE, the decision-making behavior is performed by the first network element. Therefore, the SMF can not have to know the access delay threshold of the application, and then the third indication information can include the identifier of the application but not the access delay threshold of the application.

[0212] S604, the UE sends a session establishment request message to the SMF. Correspondingly, the SMF receives the session establishment request message from the UE.

[0213] The session establishment request message can be used for the UE to establish a session with the SMF, and the session is, for example, a PDU session. For example, the UE requests to access the first application, and the UE can request to establish a PDU session with the SMF to transmit the data corresponding to the first application.

[0214] S605, the SMF sends a first creation request message to the EASDF. Correspondingly, the EASDF receives the first creation request message from the SMF.

[0215] The SMF receiving the session establishment request message can select the EASDF, and can send a first creation request message to the EASDF. For the first creation request message, refer to Figure 5 S504 in the embodiment shown.

[0216] S606, the EASDF sends a first creation response to the SMF. Correspondingly, the SMF receives the first creation response from the EASDF.

[0217] The EASDF receiving the first creation request message can send a first creation response to the SMF. For the first creation response, refer to Figure 3 S505 in the embodiment shown.

[0218] S607, the SMF sends a session establishment acceptance message to the UE. Correspondingly, the UE receives the session establishment acceptance message from the SMF.

[0219] The SMF receiving the first creation response can send a session establishment acceptance message to the UE. The session establishment acceptance message can indicate that the PDU session establishment is successful. The session establishment acceptance message can include address information of the DNS server, for example, the address information of the DNS server included in the session establishment acceptance message is the address information of the EASDF.

[0220] S608, the UE sends a DNS query request to the EASDF. Correspondingly, the EASDF can receive the DNS query request.

[0221] For example, the UE can send a DNS query request to the EASDF according to the address information of the EASDF. The DNS query request can include the identifier of the first application.

[0222] S609, the EASDF sends the identifier of the first application to the SMF. Correspondingly, the SMF receives the identifier of the first application from the EASDF.

[0223] The EASDF receiving the DNS query request can determine whether to send the identifier of the first application to the SMF according to the identifier of the first application and the DNS processing rule. For example, the EASDF sends the identifier of the first application to the SMF, and correspondingly, the SMF can receive the identifier of the first application. For example, the EASDF can invoke a service operation of the EASDF to send the identifier of the first application according to the identifier of the first application and the DNS processing rule, for example, the service operation is called a fifth service operation, and the fifth service operation can be used for the EASDF to send a request to the SMF. The fifth service operation can include the identifier of the first application. Correspondingly, the SMF can receive the fifth service operation. For example, the fifth service operation is

[0224] Neasdf_DNSContext_Notify_Request. The S609 performed by the EASDF is equivalent to informing the SMF that the network is able to support the requirement of the UE, and then the SMF can further select a DNAI for the UE (or for the first application of the UE).

[0225] S610. The SMF sends fifth information to the first network element. Correspondingly, the first network element receives the fifth information from the SMF. The fifth information can indicate the application accessed by the UE, so that the SMF can determine the application accessed by the UE according to the fifth information.

[0226] For example, the fifth information includes the identifier of the first application, to indicate that the UE requests to access the first application. The first network element can determine that the UE requests to access the first application according to the identifier of the first application. For example, the identifier of the first application is the FQDN of the first application. Optionally, the fifth information can further include at least one DNAI. The embodiments of the present application can select the DNAI (for example, the first DNAI) for the UE by the first network element, so that the SMF can perform S610 after receiving the identifier of the first application from the EASDF. For example, the SMF can determine the at least one DNAI, and send the at least one DNAI and the identifier of the first application to the first network element through the fifth information, so that the first network element selects the DNAI for the UE. For the at least one DNAI and how the SMF determines the at least one DNAI, etc., please refer to S509 of the embodiments shown in Figure 5

[0227] The first network element receives the fifth information, and can know that the UE requests to access the first application. Therefore, S610 is, for example, S301 in the embodiments shown in Figure 3

[0228] S611. The first network element determines the processing delay of N EASs in at least one DN. The at least one DN is identified by at least one DNAI. One DNAI can identify one DN, so at least one DNAI can identify at least one DN. There can be one or more EASs in one DN, and the N EASs are, for example, all or part of the EASs in the at least one DN.

[0229] ​​The first network element can obtain the third information through S602b. The first network element can determine the processing delay of the N EASs in the at least one DN according to the third information and the fourth information. The fourth information can include the number of access users of the EASs in each of the at least one DN. It can be understood that the fourth information includes the number of access users of the N EASs in the at least one DN, and the fifth information includes the association between the load (for example, the number of access users) of the EASs and the processing delay of the EASs, so that the first network element can determine the processing delay corresponding to the fourth information from the third information.

[0230] Optionally, if the fifth information includes the at least one DNAI, the first network element can directly determine the at least one DNAI, so as to determine the processing delay of the N EASs in the at least one DN. Or, if the fifth information does not include the at least one DNAI, the first network element can determine the processing delay of all or part of the EASs in the DN supporting the identification of all the DNAIs of the first application, wherein all or part of the EASs in the DN supporting the identification of all the DNAIs of the first application supporting the first application can include the N EASs.

[0231] For more information about S611, for example, how the first network element determines the processing delay of the N EASs, etc., please refer to one or more of S509, S509a or S509b of the embodiments shown in the figure. For example, please refer to the process of determining the processing delay of the N EASs by the UDR in one or more of them. Figure 5

[0232] S612, the first network element selects a first DNAI for the UE. The EASs in the DN identified by the first DNAI support the first application. For example, the first network element selects the first DNAI from the at least one DNAI, and the UE can access the first application supported by the EASs in the DN identified by the first DNAI to obtain the service corresponding to the first application. The sum of the first delay and the second delay can be less than or equal to the access delay threshold of the first application. Or, optionally, the sum of the first delay, the second delay and the third delay can be less than or equal to the access delay threshold of the first application. S612 is, for example, S302 in the embodiments shown in the figure. Or, S612 is an optional implementation of S302. Therefore, the introduction of the concepts of the first delay, the second delay and the third delay can refer to S302. Figure 5

[0233] Optionally, in S612, the first network element can select the first DNAI for the UE from the at least one DNAI according to the processing delay of the N EASs, the delay A or the delay C or the transmission delay corresponding to the at least one DNAI, and the access delay threshold of the first application.

[0234] ​​The first network element can determine the processing delay of the N EASs and obtain the access delay threshold of the first application through S611 as described above, and can also obtain the delay A or the delay C or the transmission delay corresponding to each DNAI in the K DNAIs through S601, for example, the K DNAIs include the at least one DNAI. Therefore, the first network element can select one DNAI from the at least one DNAI according to the processing delay of the N EASs, the delay A or the delay C or the transmission delay corresponding to the at least one DNAI, and the access delay threshold of the first application. The selected DNAI can be referred to as a selected DNAI. For example, the first network element selects the first DNAI, and the first DNAI can be referred to as a selected DNAI. For the process of selecting a DNAI and the like, please refer to Figure 5 S510 of the embodiment shown.

[0235] S613, the first network element sends the first DNAI to the SMF. Correspondingly, the SMF receives the first DNAI from the first network element.

[0236] S614, the SMF sends the ECS option to the EASDF. Correspondingly, the EASDF receives the ECS option from the SMF.

[0237] After receiving the ECS option, the EASDF can add the ECS option to the DNS query message and send the DNS query message to the DNS server. After receiving the ECS option, the DNS server can determine a certain EAS in the DN identified by the first DNAI, for example, the DNS server determines the first EAS, and the DNS server can send the address information of the first EAS to the EASDF. In the embodiment of the application, each EAS in the DN identified by one DNAI supports the same application, and the performance of each EAS in the DN identified by one DNAI is the same or similar, so the first EAS selected by the DNS server can meet the access delay threshold of the first application, that is, the sum of the first delay and the second delay can be less than or equal to the access delay threshold of the first application, or the sum of the first delay, the second delay and the third delay can be less than or equal to the access delay threshold of the first application.

[0238] For more information about S614, please refer to Figure 7 S511 of the embodiment shown.

[0239] S615, the SMF selects the ULCL / BP and the local PSA according to the first DNAI. For this step, please refer to Figure 7 S512 of the embodiment shown. S615 occurs before S614 or after S614, which is not limited.

[0240] S616, the EASDF sends the address information of the first EAS to the UE. Correspondingly, the UE receives the address information of the first EAS from the EASDF.

[0241] For example, the EASDF determines the first EAS in the first DNAI, the EASDF can send a DNS response to the UE, the DNS response can include the address information of the first EAS, for example, an IP address. S616 occurs before S615, or after S615, which is not limited.

[0242] Optionally, the EASDF can also send the address information of the first EAS to the SMF, and the SMF can receive the address information of the first EAS. This step can occur after S615. In addition, this step occurs before S616, or after S616, or simultaneously with S616.

[0243] S617, the first network element updates the number of access users of the first EAS. For example, in S617, the first network element can increase the number of access users of the first EAS by 1. Since the first network element stores the third information and the first information, the third information can be maintained by the first network element, and does not have to be maintained by the UDR, so the first network element can update the third information, for example, update the number of access users of the EAS indicated by the third information. Optionally, S617 can occur after S616, and / or after the step of the EASDF sending the address information of the first EAS to the SMF.

[0244] For example, the SMF sends a second request to the first network element. Correspondingly, the UDR receives the second request from the SMF. The second request can indicate that the number of access users of the first EAS within the DN identified by the first DNAI changes. Therefore, S617 can also be understood as that the SMF notifies the first network element that the number of access users of the first EAS within the DN identified by the first DNAI changes. The change can be an increase or a decrease. In S617, the change is an increase. Therefore, the second request can specifically indicate that the number of access users of the first EAS within the DN identified by the first DNAI increases. Alternatively, the second request can also be used to instruct the first network element to increase the number of access users of the first EAS within the DN identified by the first DNAI. For example, the second request can include first indication information used to instruct the first network element to increase the number of access users of the first EAS within the DN identified by the first DNAI, or used to indicate that the number of access users of the first EAS within the DN identified by the first DNAI increases. Optionally, the second request can further include address information of the first EAS and the first DNAI, so that the first network element knows that the second request is for the first EAS within the DN identified by the first DNAI. Optionally, the second request can further include an identifier of the UE and / or an identifier of the first application. For example, the identifier of the UE can include the SUPI of the UE; and the identifier of the first application can include the FQDN corresponding to the first application.

[0245] The number of access users of the EAS can increase or decrease. For example, the session between the UE and the SMF is released, and the UE is disconnected from the EAS, and at this time, the number of access users of the first EAS decreases. Therefore, optionally, the method can further include S618 to S620.

[0246] S618, the SMF releases the session between the UE and the SMF, for example, the session established through S604 and S607. After releasing the session, the UE is disconnected from the first EAS.

[0247] S619, the SMF sends a third request to the first network element. Correspondingly, the first network element receives the third request from the SMF.

[0248] The third request can indicate that the number of access users of the first EAS in the DN identified by the first DNAI changes. Therefore, S619 can also be understood as that the SMF notifies the first network element that the number of access users of the first EAS in the DN identified by the first DNAI changes. The change can be an increase or a decrease. In S619, the change is a decrease. Therefore, the third request can specifically indicate that the number of access users of the first EAS in the DN identified by the first DNAI decreases. Alternatively, the third request can also be used to instruct the first network element to decrease the number of access users of the first EAS in the DN identified by the first DNAI. For example, the third request can include second indication information used to indicate that the number of access users of the first EAS in the DN identified by the first DNAI decreases, or instruct the first network element to decrease the number of access users of the first EAS in the DN identified by the first DNAI. Optionally, the third request can include address information of the first EAS and the first DNAI, so that the first network element knows that the third request is for the first EAS in the DN identified by the first DNAI. Optionally, the third request can also include an identifier of the UE and / or an identifier of the first application.

[0249] In S620, the first network element updates the number of access users of the first EAS. For example, in S620, the first network element can decrease the number of access users of the first EAS by 1.

[0250] The number of access users of the first EAS to be decreased by the first network element, for example, is related to the number of identifiers of the UEs included in the third request. For example, the third request includes identifiers of C3 UEs, and the first network element can decrease the number of access users of the first EAS by C3. Embodiments of the present application take C3 = 1 as an example.

[0251] Alternatively, the third request can not include the identifiers of the UEs, and the first network element can decrease the number of users of the first EAS by 1 by default.

[0252] Through the scheme of the embodiments of the present application, the sum of the first delay and the second delay is less than or equal to the access delay threshold of the first application (or the sum of the first delay, the second delay, and the third delay is less than or equal to the access delay threshold of the first application), which means that both the transmission delay corresponding to the DNAI and the processing delay of the EAS are considered when selecting the DNAI, so that the selected first DNAI is more conducive to the UE to quickly access the first application, thereby enabling the UE to obtain a faster response of the EAS for application access, and facilitating the reduction of the data transmission delay between the UE and the EAS supporting the application, thereby improving the access experience of the user using the UE for the service of the application. Moreover, the function of selecting the DNAI is arranged in the first network element in the embodiments of the present application, instead of being distributed in multiple network elements, which reduces the interaction process between the network elements, saves transmission overhead, and reduces processing delay.

[0253] The fifth communication method provided by the embodiments of the present application is introduced as follows, please refer to Figure 5 for the flowchart of the method.

[0254] S701, the SMF obtains the delay A or the delay C or the transmission delay (for example, the transmission delay) corresponding to each of the K DNAIs. Figure 14 K is a positive integer.

[0255] For more information about S701, please refer to Figure 5 S501 in the embodiments shown in

[0256] S702a, the AF sends third information, second information and first information to the NEF, and correspondingly, the NEF receives the third information, the second information and the first information from the AF. The NEF sends the third information, the second information and the first information to the second network element, and correspondingly, the second network element receives the third information, the second information and the first information from the NEF. The embodiments of the present application take the second network element as the UDR for example. Wherein, the NEF sends the third information and the first information to the UDR, and this step can also be understood as that the NEF stores the third information and the first information in the UDR.

[0257] S702b, the UDR sends the second information and the first information to the SMF. Correspondingly, the SMF receives the second information and the first information from the UDR.

[0258] The second information can include address information of N EASs in the DN identified by the at least one DNAI. Wherein, the at least one DN is identified by the at least one DNAI. One DNAI can identify one DN, and then the at least one DNAI can identify at least one DN. There can be one or more EASs in one DN, and the N EASs are for example all or part of the EASs in the at least one DN. The address of the EAS is for example the IP address of the EAS. For example, refer to Figure 5 Table 4 shown in, the second information can include one or more items in Table 4. One row in Table 4 represents a DNAI capable of supporting an application and an EAS in the DN identified by the DNAI (the EAS is the EAS in the DN identified by the DNAI capable of supporting the application), and then one row in Table 4 is regarded as one item.

[0259] In Table 4, the EAS with IP address #1 existing in the DN identified by DNAI#1 supports FQDN#1, and the EAS with IP address #1 existing in the DN identified by DNAI#2 also supports FQDN#1. The EAS with IP address #3 existing in the DN identified by DNAI#1 supports FQDN#2, and so on. As can be seen, in the embodiment of the present application, one or more EASs can exist in the DN identified by one DNAI, and different EASs can support the same application, or different EASs can support different applications, which is more flexible.

[0260] For more information about S702a and S702b, such as the content of the third information and the first information, etc., refer to Figure 5 S502a and S502b of the embodiment shown in

[0261] S703, the UE sends a session establishment request message to the SMF, and correspondingly, the SMF receives the session establishment request message from the UE. The session establishment request message can be used for the UE to establish a session with the SMF, and the session is, for example, a PDU session. For example, the UE requests to access a first application, and the UE can request to establish a PDU session with the SMF to transmit data corresponding to the first application.

[0262] S704, the SMF sends a first creation request message to the EASDF. Correspondingly, the EASDF receives the first creation request message from the SMF. For more information about S704, refer to Figure 5 S504 of the embodiment shown in

[0263] S705, the EASDF sends a first creation response to the SMF. Correspondingly, the SMF receives the first creation response from the EASDF. For more information about S705, refer to Figure 3 S505 of the embodiment shown in

[0264] S706, the SMF sends a session establishment acceptance message to the UE. Correspondingly, the UE receives the session establishment acceptance message from the SMF. For more information about S706, refer to Figure 5 S506 of the embodiment shown in

[0265] S707, the UE sends a DNS query request to the EASDF. Correspondingly, the EASDF receives the DNS query request from the UE. For example, the UE can send the DNS query request to the EASDF according to the address information of the EASDF. The DNS query request can include the identification of the first application.

[0266] S708, the EASDF sends fifth information to the first network element. Correspondingly, the first network element receives the fifth information from the EASDF. In embodiments of the present application, the first network element is, for example, an SMF, and hereinafter the SMF is taken as an example.

[0267] The fifth information can indicate the application accessed by the UE, so that the SMF can determine the application accessed by the UE according to the fifth information. For example, the fifth information includes an identifier of the first application, to indicate that the UE requests to access the first application, so that the first network element can determine the first application accessed by the UE according to the identifier of the first application. For example, the identifier of the first application is the FQDN of the first application. For example, after receiving the DNS query request, the EASDF can determine whether to send the identifier of the first application to the SMF according to the identifier of the first application and the DNS processing rule. Embodiments of the present application take the EASDF sending the identifier of the first application to the SMF as an example.

[0268] Optionally, S708 can be performed after S707, for example, in S708, the EASDF can invoke a service operation of the EASDF to send the fifth information to the SMF, for example, the service operation is called a sixth service operation, and the sixth service operation can be used for the EASDF to send a request to the SMF. The sixth service operation can include the fifth information. Correspondingly, the SMF can receive the sixth service operation. For example, the sixth service operation is Neasdf_DNSContext_Notify_Request. The EASDF performing S708 is equivalent to informing the SMF that the network can support the requirement of the UE, and after receiving the fifth information, the SMF can select a DNAI for the UE (or for the first application of the UE).

[0269] After the SMF receives the fifth information, it can know that the UE requests to access the first application, so S708 is equivalent to S301 shown in the embodiments. Figure 5 S301 shown in the embodiments is, for example, the same step, or it is understood that S708 is an optional implementation of S301.

[0270] For more information about S708, refer to S508 of the embodiments shown in Figure 4 .

[0271] S709, the SMF determines the processing delay of N EASs in the DNAI identified by the at least one DNAI.

[0272] For example, S709 is similar to S509 of the embodiments shown in Figure 4 .

[0273] S709a, the SMF sends a first request to the UDR. Correspondingly, the UDR receives the first request from the SMF.

[0274] S709a is, for example, the same step as S401 in the embodiment shown in Figure 5 S401 in the embodiment shown in

[0275] S709b, the UDR sends a response to the first request to the SMF. Correspondingly, the SMF receives the response from the UDR. The response can include the processing delay of the N EASs.

[0276] There can be one or more EASs in a DN identified by one DNAI. The embodiments of the present application take, for example, the case that different EASs in a DN identified by one DNAI can support the same or different applications, and in addition, the embodiments of the present application also take the case that the performance of different EASs in a DN identified by one DNAI is the same or different. Therefore, in the embodiments of the present application, the processing delay of the EASs in a DN identified by one DNAI can include the processing delay of all the EASs in the DN identified by the DNAI. For example, the at least one DNAI includes a second DNAI, there are E EASs in a DN identified by the second DNAI, and the processing delay of the E EASs can include the processing delay of all the E EASs. E is a positive integer less than or equal to N, and the second DNAI can be any one of the at least one DNAI. In this case, the processing delay of the N EASs determined by the UDR can include the processing delay of each of the N EASs. For example, the number of the at least one DNAI is 3, and there are 7 EASs in the DNs identified by the 3 DNAIs (for example, there are EAS1 and EAS2 in a DN identified by DNAI#1, there are EAS3, EAS4 and EAS5 in a DN identified by DNAI#2, and there are EAS6 and EAS7 in a DN identified by DNAI#3). Then, the processing delay of the 7 EASs in the DNs identified by the 3 DNAIs can include the processing delay of each of the 7 EASs.

[0277] S709b is, for example, the same step as S402 in the embodiment shown in Figure 3 S402 in the embodiment shown in

[0278] For more information about the steps S709, S709a and S709b, reference can be made to Figure 3 S509, S509a and S509b in the embodiment shown in

[0279] S710, the SMF selects a first EAS within a DN identified by the first DNAI for the UE. The first EAS supports the first application. The UE can access the first application supported by the first EAS to obtain a service corresponding to the first application. A sum of the first latency and the second latency can be less than or equal to an access latency threshold of the first application. Alternatively, a sum of the first latency, the second latency, and the third latency can be less than or equal to the access latency threshold of the first application. For details of the concepts of the first latency, the second latency, and the third latency, refer to the description of S302 in the embodiment shown in FIG. 7. Figure 3 S302 in the embodiment shown in FIG. 7.

[0280] Alternatively, in S710, the SMF can select a first EAS within a DN identified by the first DNAI for the UE from the N EASs according to the processing latency of the N EASs, the latency A or the latency C or the transmission latency corresponding to the at least one DNAI, the address information of the N EASs, and the access latency threshold of the first application.

[0281] In S701, the SMF obtains the latency A or the latency C or the transmission latency corresponding to each of the K DNAIs, for example, the K DNAIs include the at least one DNAI. In S702b, the SMF obtains the access latency threshold of the first application and the address information of the N EASs. In S709, the SMF determines the processing latency of the N EASs. Based on the above, the SMF can select an EAS from the N EASs according to the processing latency of the N EASs, the latency A or the latency C or the transmission latency corresponding to the at least one DNAI, the address information of the N EASs, and the access latency threshold of the first application. The DNAI corresponding to the selected EAS (i.e., the EAS is located within the DN identified by the DNAI) can be referred to as a selected DNAI. For example, the SMF selects a first EAS within a DN identified by the first DNAI, and the first DNAI can be referred to as the selected DNAI.

[0282] In the embodiments of the present application, the SMF can determine the processing delay of each EAS in the DN identified by the DNAI, and the processing delay of each EAS can be involved in determining the EAS. For example, the SMF can determine the sum of the processing delay A or the processing delay C or the transmission delay corresponding to each DNAI in the at least one DNAI and the processing delay of each EAS in the DN identified by the DNAI, and a total of P sum values can be determined, P being a positive integer, for example, P is equal to the total number of EASs in the at least one DN identified by the at least one DNAI. The SMF can determine a sum value from the P sum values that is less than or equal to the access delay threshold of the first application, and determine that the DNAI corresponding to the sum value is the first DNAI, and the EAS corresponding to the sum value is the first EAS. Optionally, the sum value determined by the SMF can not only be less than the access delay threshold of the first application, but also be the minimum value among the P sum values, so that the UE can obtain better service quality.

[0283] Optionally, the SMF can first determine the EAS according to the delay A or the delay C corresponding to the DNAI (whether to use the delay A or the delay C can also be preconfigured or pre-defined by a protocol or determined by the SMF). For example, the SMF determines at least one sum value according to the delay A or the delay C corresponding to the DNAI, and then determines a first sum value from the at least one sum value. For example, the first sum value is the minimum value among the at least one sum value, and the first sum value corresponds to the first EAS. If the first sum value is less than or equal to the access delay threshold of the first application, the SMF can further determine the sum value of the first sum value and the third delay, for example, referred to as sum value A. If the sum value A is also less than or equal to the access delay threshold of the first application, the SMF can finally select the first EAS for the UE; and if the sum value A is greater than the access delay threshold of the first application, the SMF can not select the first EAS for the UE, at this time, it is considered that the selection of the EAS fails, or it is considered that the selection of the DNAI and the EAS fails. Or, if the first sum value is greater than the access delay threshold of the first application (since the first sum value is the minimum value among the at least one sum value, therefore the at least one sum value is greater than the access delay threshold of the first application), the SMF can not have to determine the sum value of the first sum value and the third delay, and also not select the first EAS for the UE, at this time, it is considered that the selection of the EAS fails, or it is considered that the selection of the DNAI and the EAS fails.

[0284] Alternatively, whether the SMF selects the EAS according to the latency A, the latency C or the transmission latency corresponding to the DNAI, can be pre-configured, or predefined by a protocol, or determined by the SMF itself. For example, if it is pre-configured to select the EAS according to the transmission latency corresponding to the DNAI, the SMF can select one EAS for the UE from the N EASs according to the processing latency of the N EASs, the transmission latency corresponding to the at least one DNAI, and the access latency threshold of the first application. For another example, if it is pre-configured to select the DNAI according to the latency A corresponding to the DNAI, the SMF can select one EAS for the UE from the N EASs according to the processing latency of the N EASs, the latency A corresponding to the at least one DNAI, and the access latency threshold of the first application, without considering the latency B corresponding to the DNAI.

[0285] For example, the SMF determines that the DNAIs accessible to the UE at its current location include DNAI#1 and DNAI#2. In addition, according to Table 4, the EASs supporting FQDN#1 include the EAS with IP address #1 in the DN identified by DNAI#1, for example, EAS1, and the EAS with IP address #2 in the DN identified by DNAI#2, for example, EAS2. Then, the SMF can determine the transmission latency of DNAI#1 and the transmission latency of DNAI#2. For example, according to Table 1-1, the transmission latency of DNAI#1 is 50 ms, and the transmission latency of DNAI#1 is 45 ms. The SMF can determine the processing latency of the EAS in the DN identified by DNAI#1 and the processing latency of the EAS in the DN identified by DNAI#2 according to the response from the UDR in S709b. For example, the processing latency of EAS1 is determined to be 20 ms, and the processing latency of EAS2 is determined to be 40 ms. The SMF can determine that the sum of the transmission latency of DNAI#1 and the processing latency of EAS1 is 70 ms, and the sum of the transmission latency of DNAI#2 and the processing latency of EAS2 is 85 ms. For example, the first application requested to be accessed by the UE is FQDN#1, and according to Table 3, the access latency threshold of the first application is 80 ms. Then, the SMF can determine that the EAS1 in the DN identified by DNAI#1 can meet the access latency threshold of the first application, and can select the EAS1 in the DN identified by DNAI#1 for the UE, or can select DNAI#1 and EAS1 for the UE.

[0286] As introduced above, the P sum values determined by the SMF can all be greater than the access latency threshold of the first application, or the sum of the first sum value corresponding to the first EAS and the third latency can be greater than the access latency threshold of the first application, and no EAS in the N EASs meets the access latency threshold of the first application. In this case, the SMF can not select a DNAI or an EAS for the UE, that is, the process of selecting a DNAI fails, or the process of selecting a DNAI and an EAS fails, and the access of the UE also fails; or the SMF can also select an EAS for the UE from the N EASs, for example, the SMF selects the EAS corresponding to the first sum value, although the EAS cannot meet the access latency threshold of the first application, but can try to improve the access success rate of the UE.

[0287] Optionally, S710 can include a step of selecting, by the SMF, the first EAS in the DN identified by the first DNAI for the UE. Alternatively, S710 can include two steps, wherein the first step (for example, step a) includes selecting, by the SMF, the first DNAI for the UE, and the second step (for example, step b) includes selecting, by the SMF, the first EAS in the DN identified by the first DNAI for the UE. Alternatively, S710 can include a step of selecting, by the SMF, the first EAS in the DN identified by the first DNAI for the UE, and before S710, the embodiments of the present application further include a step (for example, step c) of selecting, by the SMF, the first DNAI for the UE.

[0288] If S710 includes two steps or step c before S710, in S710 or step c, the SMF can select the first DNAI for the UE from the at least one DNAI according to the processing latency of the N EASs in the at least one DN identified by the at least one DNAI, the latency A or the latency C or the transmission latency corresponding to the at least one DNAI, and the access latency threshold of the first application; and in S710, the SMF can select the first EAS for the UE in the DN identified by the first DNAI according to the address information of the N EASs. In addition, when S710 includes two steps or step c before S710, other related contents can be referred to the foregoing.

[0289] If S710 includes one step or two steps, S710 and Figure 2A S302 in the embodiment shown in FIG. 7 can be the same step; or S710 is an optional implementation of S302. Alternatively, if step c is included before S710, step c and Figure 5S302 in the illustrated embodiment can be the same step; or, step c is an optional implementation of S302, and S710 is a step after S302.

[0290] In the embodiment, the SMF obtains the address information of the N EASs through S702b, so that the SMF can select the EAS for the UE without having to select the EAS for the UE by the DNS. The SMF selects the EAS for the UE according to multiple parameters such as the processing delay of the EAS. Compared with the scheme of selecting the EAS by the DNS server, the embodiment is more conducive to selecting the EAS with the smallest delay between the UE, so that the user experience is better. Moreover, the embodiment does not require that the EASs in a DN identified by a DNAI all support the same application, and does not require that the performances of the EASs are all the same. For example, the EASs in a DN identified by a DNAI can support the same or different applications, and the performances can also be the same or different, so that the network deployment is more flexible.

[0291] S711, the SMF sends the address information of the first EAS to the EASDF. Correspondingly, the EASDF receives the address information of the first EAS.

[0292] The address of the first EAS is, for example, the IP address of the first EAS. Optionally, the SMF can send the first DNAI and the address information of the first EAS to the EASDF in S711. For example, the SMF can send the first DNAI and the address information of the first EAS to the EASDF in S711. Figure 5 For example, the network architecture illustrated, for example, the SMF calls the service operation of the EASDF to send the address information of the first EAS to the EASDF, which is, for example, called the seventh service operation. The seventh service operation can be used for the SMF to send a response to the EASDF. The seventh service operation can include the address information of the first EAS, and optionally include the first DNAI. Correspondingly, the EASDF can receive the seventh service operation. For example, the seventh service operation is Neasdf_DNSContext_Notify_Response. The seventh service operation is, for example, a response of the sixth service operation described in S708.

[0293] Since the EASDF has obtained the address information of the first EAS from the SMF, the EASDF does not have to interact with the DNS server, for example, the EASDF can not send a DNS query message to the DNS server.

[0294] S712, the SMF selects the ULCL / BP and the local PSA according to the first DNAI. For more details of this step, please refer to Figure 5 S512 of the illustrated embodiment. S712 occurs before S711 or after S711, which is not limited.

[0295] S713, the EASDF sends the address information of the first EAS to the UE. Correspondingly, the UE receives the address information from the EASDF.

[0296] For example, the EASDF receives the first EAS in the first DNAI from the SMF, the EASDF can send a DNS response to the UE, the DNS response can include the address information of the first EAS. Since the EASDF obtains the address information of the first EAS from the SMF, optionally, the SMF can also be considered to indirectly send the address information of the first EAS to the UE. S713 occurs before S712 or after S712, which is not limited.

[0297] Through the above process, the number of access users of the first EAS increases (i.e., the UE is added). In order to enable the UDR to more accurately determine the processing delay of the first EAS, the method can further include S714 and S715.

[0298] S714, the SMF sends a second request to the UDR. Correspondingly, the UDR receives the second request from the SMF. The second request message can indicate that the number of access users of the first EAS in the DN identified by the first DNAI changes. For more details about this step, please refer to Figure 5 S514 of the embodiment shown in

[0299] S715, the UDR updates the number of access users of the first EAS. For example, in S715, the UDR can add 1 to the number of access users of the first EAS. For more details about this step, please refer to Figure 5 S515 of the embodiment shown in

[0300] The number of access users of the EAS can increase or decrease. For example, the session between the UE and the SMF is released, the UE is disconnected from the EAS, at this time the number of access users of the first EAS decreases. Therefore, optionally, the method can further include S716 to S718.

[0301] S716, the SMF releases the session with the UE. The session is, for example, the session established through steps S703 and S706. After releasing the session, the UE is disconnected from the first EAS.

[0302] S717, the SMF sends a third request to the UDR. Correspondingly, the UDR receives the third request from the SMF. The third request can indicate that the number of access users of the first EAS in the DN identified by the first DNAI changes. Therefore, S717 can also be understood as that the SMF notifies the UDR that the number of access users of the first EAS in the DN identified by the first DNAI changes. For more details about this step, please refer to Figure 8S517 of the illustrated embodiment.

[0303] S718, the UDR updates the number of access users of the first EAS. For example, in S718, the UDR can decrease the number of access users of the first EAS by 1. More details about this step can be referred to Figures 3-7 S518 of the illustrated embodiment.

[0304] By the scheme of the embodiments of the present application, the sum of the first time delay and the second time delay is less than or equal to the access time delay threshold of the first application (or the sum of the first time delay, the second time delay and the third time delay is less than or equal to the access time delay threshold of the first application), which means that when selecting the DNAI, both the transmission time delay corresponding to the DNAI and the processing time delay of the EAS are considered, so that the selected first DNAI is more conducive to the UE to quickly access the first application, thereby making the UE access the application to obtain a faster response of the EAS, which is conducive to reducing the data transmission time delay between the UE and the EAS supporting the application, thereby improving the access experience of the user using the UE to the service of the application. Moreover, in the embodiments of the present application, the SMF can obtain the address information of the EAS, so that the SMF can select the EAS for the UE, which is conducive to selecting an EAS with better overall time delay to improve the user experience.

[0305] Figures 3-7 A structure schematic diagram of a communication apparatus provided by an embodiment of the present application is given. The communication apparatus 800 can be a first network element or circuit system of the first network element in the embodiments shown in any one of the accompanying drawings, for implementing the methods corresponding to the first network element in the above method embodiments. Alternatively, the communication apparatus 800 can be a second network element or circuit system of the second network element in the embodiments shown in any one of the accompanying drawings, for implementing the methods corresponding to the second network element in the above method embodiments. The specific functions can be referred to the descriptions in the above method embodiments. For example, one circuit system is a chip system. Figure 8 Figures 3-7 The communication apparatus 800 includes at least one processor 801. The processor 801 can be used for internal processing of the apparatus, to implement certain control processing functions. Optionally, the processor 801 includes instructions. Optionally, the processor 801 can store data. Optionally, different processors can be independent devices, can be located in different physical positions, and can be located on different integrated circuits. Optionally, different processors can be integrated in one or more processors, for example, integrated on one or more integrated circuits.

[0306] The communication apparatus 800 includes at least one processor 801. The processor 801 can be used for internal processing of the apparatus, to implement certain control processing functions. Optionally, the processor 801 includes instructions. Optionally, the processor 801 can store data. Optionally, different processors can be independent devices, can be located in different physical positions, and can be located on different integrated circuits. Optionally, different processors can be integrated in one or more processors, for example, integrated on one or more integrated circuits.

[0307] ​Optionally, the communication device 800 comprises one or more memories 803 to store instructions. Optionally, the memories 803 can also store data. The processor and the memories can be separately arranged or integrated together.

[0308] Optionally, the communication device 800 comprises a communication line 802 and at least one communication interface 804. Since the memories 803, the communication line 802 and the communication interface 804 are all optional, they are represented by dashed lines in the figure. Figures 3-7

[0309] Optionally, the communication device 800 can also comprise a transceiver and / or an antenna. The transceiver can be used to send information to other devices or receive information from other devices. The transceiver can be referred to as a transceiver, a transceiving circuit, an input / output interface, etc., and is used to realize the transceiving function of the communication device 800 through the antenna. Optionally, the transceiver comprises a transmitter and a receiver. Illustratively, the transmitter can be used to generate a radio frequency signal from a baseband signal, and the receiver can be used to convert a radio frequency signal into a baseband signal.

[0310] The processor 801 can comprise a general central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs of the solutions of the present application.

[0311] The communication line 802 can comprise a path to transmit information between the above-mentioned components.

[0312] The communication interface 804 uses any transceiver-like device for communicating with other devices or communication networks, such as an Ethernet, a radio access network (RAN), a wireless local area network (WLAN), a wired access network, etc.

[0313] ​The memory 803 can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM), or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, a magnetic disk storage or other magnetic storage devices, or any other medium capable of storing desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to this. The memory 803 can exist independently, and is connected to the processor 801 through the communication line 802. Alternatively, the memory 803 can be integrated with the processor 801.

[0314] The memory 803 is configured to store computer-executed instructions for implementing the solutions of the present application, and the processor 801 is configured to control the execution of the computer-executed instructions stored in the memory 803. Figure 8 The processor 801 is configured to execute the computer-executed instructions stored in the memory 803, so as to implement the steps performed by the first network element in the embodiments shown in any one of the accompanying drawings, or implement the steps performed by the second network element in the embodiments shown in any one of the accompanying drawings. Figure 8 The processor 801 is configured to execute the computer-executed instructions stored in the memory 803, so as to implement the steps performed by the first network element in the embodiments shown in any one of the accompanying drawings, or implement the steps performed by the second network element in the embodiments shown in any one of the accompanying drawings.

[0315] Optionally, the computer-executed instructions in the embodiments of the present application can also be referred to as application program codes, and the embodiments of the present application are not limited in this regard.

[0316] In a specific implementation, as an example, the processor 801 can include one or more CPUs, such as the CPU0 and the CPU1 in FIG. 8. Figure 8 In a specific implementation, as an example, the processor 801 can include one or more CPUs, such as the CPU0 and the CPU1 in FIG. 8.

[0317] In a specific implementation, as an example, the communication apparatus 800 can include multiple processors, such as the processor 801 and the processor 805 in FIG. 8. Each of the processors can be a single-CPU processor or a multi-CPU processor. The processor herein can refer to one or more devices, circuits, and / or processing cores for processing data (for example, computer program instructions). Figure 9

[0318] When the communication apparatus 800 is in the active mode, the processor 801 is configured to execute the computer-executed instructions stored in the memory 803, so as to implement the steps performed by the first network element in the embodiments shown in any one of the accompanying drawings, or implement the steps performed by the second network element in the embodiments shown in any one of the accompanying drawings. Figures 3-7 ​When the apparatus is a chip, for example, a chip of the first network element or a chip of the second network element, the chip includes the processor 801 (and can also include the processor 805), the communication line 802, and the communication interface 804, and optionally, the memory 803. Specifically, the communication interface 804 can be an input interface, a pin, or a circuit, etc. The memory 803 can be a register, a cache, etc. The processor 801 and the processor 805 can be a general-purpose CPU, a microprocessor, an ASIC, or one or more integrated circuits for executing programs for controlling the communication method of any of the above embodiments.

[0319] The embodiments of the present application can divide the functions of the apparatus according to the above method examples, for example, each function module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated module can be realized in the form of hardware or in the form of a software function module. It should be noted that the division of the modules in the embodiments of the present application is illustrative, and is only a logical function division. When each function module is divided according to each function, for example, Figure 9 An apparatus schematic diagram is shown, which is the apparatus 900 that can be the first network element or the second network element involved in any of the above method embodiments, or a chip in the first network element or a chip in the second network element. The apparatus 900 includes a sending unit 901, a processing unit 902, and a receiving unit 903.

[0320] It should be understood that the apparatus 900 can be used to implement the steps performed by the first network element or the second network element in the communication method of the embodiments of the present application, and the related features can refer to the embodiments shown in any of the above Figure 8 , and will not be described here.

[0321] Optionally, Figure 9 The functions / implementation processes of the sending unit 901, the receiving unit 903, and the processing unit 902 in the above Figure 8 may be realized by the processor 801 in the above Figure 9 invoking computer-executable instructions stored in the memory 803. Alternatively, Figure 8 The functions / implementation processes of the processing unit 902 in the above ​ may be realized by the processor 801 in the above ​ invoking computer-executable instructions stored in the memory 803.

[0322] Optionally, when the apparatus 900 is a chip or a circuit, the functions / implementation processes of the sending unit 901 and the receiving unit 903 can also be realized by a pin or a circuit, etc.

[0323] The application further provides a computer readable storage medium storing a computer program or instructions, which, when executed, implement the method performed by the first network element or the second network element in the foregoing method embodiments. In this way, the functions described in the foregoing embodiments can be implemented in the form of software function units and sold or used as independent products. Based on this understanding, the technical solutions of the application can essentially or in part or parts of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in the embodiments of the application. The storage medium includes: a U disk, a mobile hard disk, a ROM, a RAM, a magnetic disk or an optical disk, and various media that can store program codes.

[0324] The application further provides a computer program product, which includes computer program codes, which, when executed on a computer, cause the computer to perform the method performed by the first network element or the second network element in any of the foregoing method embodiments.

[0325] The embodiments of the application further provide a processing apparatus, including a processor and an interface; the processor is used to execute the method performed by the first network element or the second network element related to any of the foregoing method embodiments.

[0326] In the embodiments described above, all or some of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or some of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded into and executed by a computer, all or some of the procedures or functions described in the embodiments of the present application are performed. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from a website, a computer, a server or a data center to another website, computer, server or data center through a wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media sets. The available media can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, DVD), or a semiconductor medium (for example, solid state disk (SSD)) and the like.

[0327] The various illustrative logical blocks, modules, circuits, and algorithms described in connection with the embodiments disclosed herein can be implemented or performed by a general purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the described functions. The general purpose processor can be a microprocessor, optionally, the general purpose processor can also be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other similar configuration.

[0328] The steps of methods or algorithms described in the embodiments of the present application can be directly embedded in hardware, a software unit executed by a processor, or a combination of both. The software unit can be stored in a RAM, a flash memory, a ROM, an erasable programmable read-only memory (EPROM), an EEPROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium in the art. The storage medium can be connected to the processor, so that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium can be integrated into the processor. The processor and the storage medium can be located in an ASIC. The ASIC can be located in the terminal device. Alternatively, the processor and the storage medium can also be located in different components of the terminal device.

[0329] These computer program instructions can also be loaded onto a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable data processing device to generate a computer implemented process such that the instructions executed by the computer or other programmable device provide steps for implementing the functions specified in the flowchart block or blocks and / or the block or blocks in the block diagram.

[0330] The contents in various embodiments of the present application can be mutually referred to. If there is no special description and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be mutually referred to. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0331] It can be understood that, in the embodiments of the present application, the first network element or the second network element can perform part or all of the steps in the embodiments of the present application. These steps or operations are only examples, and other operations or various modifications of the operations can also be performed in the embodiments of the present application. In addition, the various steps can be performed in different orders according to the embodiments of the present application, and it is possible that not all the operations in the embodiments of the present application are performed.

Claims

1. A communication method characterized by comprising: The method comprises: The first network element learns that a terminal device requests to access a first application; The first network element selects a first data network access identifier for the terminal device; The sum of the first time delay and the second time delay is less than or equal to a threshold of an access time delay of the first application; The first time delay is a transmission time delay between the terminal device and a core network device corresponding to the first data network access identifier, or a transmission time delay between an access network device serving the terminal device and the core network device corresponding to the first data network access identifier; The second time delay is a processing time delay of an edge application server in a first data network, the first data network access identifier being used to identify the first data network, and the edge application server being used to support the first application.

2. The method of claim 1, wherein, The sum of the first time delay, the second time delay and a third time delay is less than or equal to the threshold of the access time delay of the first application, and the third time delay comprises a transmission time delay between the core network device and the edge application server.

3. The method of claim 1 or 2, wherein The method further comprises: the first network element obtaining at least one data network access identifier, wherein N edge application servers in at least one data network all support the first application, the at least one data network access identifier being used to identify the at least one data network, and N being a positive integer; The first network element selects a first data network access identifier for the terminal device, comprising: The first network element selects the first data network access identifier for the terminal device from the at least one data network access identifier.

4. The method of claim 3, wherein, The method further comprises: The first network element obtains the processing time delays of the N edge application servers.

5. The method of claim 4, wherein, The first network element obtains the processing time delays of the N edge application servers, comprising: The first network element receives association information from a second network element, the association information being used to indicate an association between a load and a processing time delay of each of the N edge application servers; According to the association information and user information, the first network element determines the processing time delays of the N edge application servers, wherein the user information comprises a number of access users of each of the N edge application servers.

6. The method of claim 4, wherein, The first network element obtains the processing time delays of the N edge application servers, comprising: The first network element sends a first request to a second network element; The first network element receives a response to the first request, the response comprising the processing time delays of the N edge application servers.

7. The method of claim 6, wherein, The first request comprises one or more of the following: An identifier of the terminal device; An identifier of the first application; or The at least one data network access identifier.

8. The method of any one of claims 4-7, wherein The processing time delays of the N edge application servers comprise processing time delays of one or more or all of the N edge application servers.

9. The method according to any one of claims 1 to 8, characterized in that, The method further comprises: The first network element receives address information of N edge application servers from a second network element, the N edge application servers are located in at least one data network, the at least one data network is identified by at least one data network access identifier, and the at least one data network includes the first data network.

10. The method of claim 9, wherein, The method further includes: The first network element sends address information of a first edge application server in the first data network to the terminal device, wherein the first edge application server is an edge application server selected by the first network element for the terminal device.

11. The method according to any one of claims 1 to 10, characterized in that, The method further includes: The first network element receives the access delay threshold value from a second network element.

12. The method of any one of claims 1-11, wherein, The method further includes: The first network element notifies a second network element that the number of access users of a first edge application server changes; or, The first network element updates the number of access users of a first edge application server; The first edge application server is in the first data network.

13. An apparatus, comprising: The apparatus includes a processing unit; The processing unit is configured to learn that a terminal device requests to access a first application; The processing unit is further configured to select a first data network access identifier for the terminal device, The sum of the first delay and the second delay is less than or equal to an access delay threshold value of the first application. The first delay is a transmission delay between the terminal device and a core network device corresponding to the first data network access identifier, or a transmission delay between an access network device serving the terminal device and the core network device corresponding to the first data network access identifier. The second delay is a processing delay of an edge application server in a first data network, the first data network access identifier is used to identify the first data network, and the edge application server is used to support the first application.

14. An apparatus, comprising: The apparatus includes: One or more processors configured to execute computer program instructions that, when executed by the one or more processors, cause the apparatus to perform the method of any one of claims 1-12.

15. A communication system, characterized by The apparatus includes: A first network element and a second network element; The first network element is configured to perform the method of any one of claims 1-12, wherein the first network element is specifically configured to obtain a processing delay of an edge application server from the second network element; The second network element is configured to receive a first request from a first network element and send a response to the first request to the first network element, wherein the first request is used to request to obtain a processing delay of an edge application server in a data network, and the response includes processing delays of N edge application servers in at least one data network, the at least one data network is identified by at least one data network access identifier, and N is a positive integer.

16. A communication system, characterized by The apparatus includes: A first network element and a terminal device; The first network element is configured to learn that a terminal device requests to access a first application, select a first data network access identifier and / or a first edge application server in a first data network for the terminal device, and send address information of the first edge application server to the terminal device, wherein the first data network access identifier is used to identify the first data network, and the first edge application server is used to support the first application. The terminal device is configured to receive the address information. The sum of the first time delay and the second time delay is less than or equal to a threshold value of an access time delay of the first application. The first time delay is a transmission time delay between the terminal device and a core network device corresponding to the first data network access identifier, or a transmission time delay between an access network device serving the terminal device and the core network device corresponding to the first data network access identifier. The second time delay is a processing time delay of the first edge application server.

17. A method of communication, comprising: The method comprises the following steps: A first network element learns that a terminal device requests to access a first application. The first network element selects a first data network access identifier and / or a first edge application server in a first data network for the terminal device, wherein the first data network access identifier is used to identify the first data network, and the first edge application server is used to support the first application. The first network element sends address information of the first edge application server to the terminal device. The terminal device receives the address information. The sum of the first time delay and the second time delay is less than or equal to a threshold value of an access time delay of the first application. The first time delay is a transmission time delay between the terminal device and a core network device corresponding to the first data network access identifier, or a transmission time delay between an access network device serving the terminal device and the core network device corresponding to the first data network access identifier. The second time delay is a processing time delay of the first edge application server.

18. A computer-readable storage medium, characterized in that, The computer readable storage medium comprises a computer program, which, when running on a computing device, causes the computing device to perform the method of any one of claims 1-12.

19. A chip, characterized by The chip is coupled with the memory, and is configured to read and execute program instructions stored in the memory, so as to implement the method of any one of claims 1-12.

20. A computer program product, characterised in that, The computer program product, when invoked by a computer, causes the computer to perform the method of any one of claims 1-12.

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