CN116260795A

CN116260795A - Method and device for selecting edge application server

Info

Publication number: CN116260795A
Application number: CN202111509231.1A
Authority: CN
Inventors: 赵鹏涛; 李岩
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-12-10
Filing date: 2021-12-10
Publication date: 2023-06-13
Also published as: WO2023104070A1

Abstract

The application provides a method and a device for selecting an edge application server, wherein the method can comprise the following steps: the application function network element receives a message from the first session management network element, the message being for indicating that an edge application server of the first terminal device is to be reselected. Wherein the first session management network element is a network element for providing services for sessions of a first terminal device, and the first terminal device belongs to a terminal set; the application function network element obtains first user plane path information of a first terminal device and second user plane path information of a second terminal device, wherein the second terminal device is a terminal device except the first terminal device in a terminal set; and the application function network element selects an edge application server for the terminal set according to the first user plane path information and the second user plane path information. According to the scheme, the edge application server can be reselected for the terminal equipment in the terminal set, and service experience after switching to the reselected edge application server is guaranteed.

Description

Method and device for selecting edge application server

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a method and an apparatus for selecting an edge application server.

Background

In an Edge Computing (EC) deployment scenario, some traffic may be served by one or more edge application servers (edge application server, EAS) deployed at the edge of the network. In some scenarios, multiple User Equipments (UEs) may need the same EAS to provide services to keep the services synchronized, and improve the user experience. For example, the popular games of the mobile terminal are mostly interactive, and often require matching of multiple users to play the games, and when multiple users in the same game request to obtain the mobile edge computing service, the network side needs to select an EAS for the multiple users.

However, it is worthwhile to reselect EAS for multiple UEs in the event that the EAS serving the multiple UEs cannot meet user requirements.

Disclosure of Invention

The application provides a method and a device for selecting an edge application server, which can be used for providing user plane path information for selecting the edge application server for a plurality of terminal devices in one terminal set and/or selecting the edge application server for a plurality of terminal devices in the same terminal set.

In a first aspect, a method for selecting an edge application server is provided, which may be performed by an application function network element, or may also be performed by a component (such as a chip or a circuit) of the application function network element, which is not limited to this, and for convenience of description, an application function network element is described below as an example.

The method may include: the application function network element receives a message from a first session management network element, wherein the message is used for indicating an edge application server of first terminal equipment to be reselected, the first session management network element is a network element for providing service for a session of the first terminal equipment, and the first terminal equipment belongs to a terminal set; the application function network element obtains first user plane path information of the first terminal equipment and second user plane path information of second terminal equipment, wherein the second terminal equipment is terminal equipment except the first terminal equipment in the terminal set; the application function network element selects a first edge application server for the terminal set according to the first user plane path information and the second user plane path information.

Based on the above scheme, the application function network element receives the message for indicating the edge application server of the first terminal device to be reselected, thereby triggering the application function network element to obtain the user plane path information of each terminal device in the terminal set, and selecting the first edge application server for the terminal set according to the user plane information.

The edge application server of the first terminal device is to be reselected, which may also be said to be the edge application server of the first terminal device is to be switched.

That is, when the edge application server of any one terminal device in the terminal set is to be reselected, the application function network element comprehensively considers the user plane path information of a plurality of terminal devices in the terminal set to select a first edge application server for the terminal set, thereby ensuring the service experience of the terminal devices in the terminal set after the edge application server is switched.

With reference to the first aspect, in certain implementations of the first aspect, the first user plane path information includes a first data network access identifier DNAI, the second user plane path information includes a second DNAI, and both the first DNAI and the second DNAI include DNAI corresponding to the first edge application server.

Based on the above scheme, after the application function network element obtains the first user plane path information and the second user plane path information, in the edge application servers corresponding to DNAI shared by the first user plane path information and the second user plane path information, the first edge application server is selected for the terminal set, so that the first edge server can simultaneously ensure service experience of a plurality of terminal devices in the terminal set.

With reference to the first aspect, in some implementations of the first aspect, the first user plane path information further includes a transmission delay corresponding to the first DNAI, the second user plane path information further includes a transmission delay corresponding to the second DNAI, and the transmission delay corresponding to the DNAI corresponding to the first edge application server is less than or equal to a threshold.

Based on the above scheme, the first user plane path information and the second user plane path information include DNAI of the user plane paths and transmission delays corresponding to DNAI, so that the application function network element can select a user plane path meeting the user plane delay requirement (i.e., a user plane path with a transmission delay less than or equal to a threshold) according to the transmission delays, and then select a first edge application server for the terminal set in one or more edge application servers corresponding to the user plane path meeting the user plane delay requirement, so as to ensure user experience after the edge application servers are switched.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: the application function network element sends an edge application server switching message to the first session management network element and the second session management network element, wherein the edge application server switching message comprises information of the first edge application server, and the edge application server switching message is used for indicating switching to the first edge application server.

Based on the above scheme, the application function network element may instruct the first session management network element and the second session management network element to reselect to the first edge application server after determining the first edge application server serving the terminal set, so that the first edge application server may serve the terminal devices in the terminal set.

With reference to the first aspect, in some implementations of the first aspect, the application function network element obtains second user plane path information of the second terminal device, including: the application function network element sends a user plane path information request message to a second session management network element according to the information of the terminal set, wherein the user plane path information request message comprises the identifier of the second terminal device, and the second session management network element is a network element for providing service for the session of the second terminal device; the application function network element receives the second user plane path information from the second session management network element.

Based on the above scheme, the application function network element may request the second user plane path information of the second terminal device from the second session management network element through the user plane path information request message.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: the application function network element determines a DNAI to be selected according to the first user plane path information, and the user plane path information request message further includes the DNAI to be selected.

Optionally, the second user plane path information includes a second DNAI, and the DNAI to be selected is used to determine the second DNAI.

Based on the above scheme, after the application function network element receives the first user plane path information, the to-be-selected DNAI may be determined according to the first user plane path information, and the to-be-selected DNAI may be carried in the user plane path information request message sent to the second session management network element. In this case, the second session management network element may select (i.e. determine the second user plane path information) from the user plane paths corresponding to the DNAI to be selected, without selecting from all the selectable user plane paths, so that resources may be saved and efficiency may be improved.

In a second aspect, a method for selecting an edge application server is provided, which may be performed by a core network element, or may also be performed by a component (such as a chip or a circuit) of the core network element, which is not limited, and is described below as being performed by a session management network element for convenience of description.

The method may include: the method comprises the steps that a session management network element sends user plane path information of terminal equipment to an application function network element, wherein the session management network element is a network element for providing services for a session of the terminal equipment, and the terminal equipment belongs to a terminal set; the session management network element receives an edge application server switching message from the application function network element, the edge application server switching message including information of the edge application server of the terminal set, the edge application server switching message being used to indicate a reselection to the edge application server.

Based on the above scheme, the session management network element may report the user plane path information of the terminal device belonging to the terminal set to the application function network element, so that the application function network element may determine an edge application server for the terminal set according to the user plane path information. And the session management network element may determine, according to the edge application server switching message of the application function network element, an edge application server to which the terminal device needs to be switched.

With reference to the second aspect, in a certain implementation manner of the second aspect, the session management network element is a network element that provides a service for a session of a terminal device in the terminal set.

The session management network element may also be referred to as an anchor session management network element at this point.

In this case, the user plane path information may be information of terminal set granularity.

Alternatively, the session management network element may be a network element that provides services for a session of a terminal device in the set of terminals. In this case, the user plane path information may be information of terminal device granularity.

With reference to the second aspect, in a certain implementation manner of the second aspect, the method further includes: the session management network element obtains the user plane path information of the terminal equipment in the terminal set.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the session management network element sends a message to the application function network element, where the message is used to indicate that an edge application server of the terminal set is to be reselected, or that an edge application server of a terminal device in the terminal set is to be reselected.

In one implementation, the user plane path information is carried in the message; in another implementation, the session management network element sends the user plane path information to the application function network element after sending the message to the application function network element.

With reference to the second aspect, in some implementations of the second aspect, the user plane path information is used to determine an edge application server for the set of terminals.

Based on the above scheme, the session management network element provides the application function network element with the user plane path information for determining the edge application server for the terminal set, so that the application function network element can determine the edge application server for the terminal set according to the user plane path information.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the session management network element determines that an edge application server of the terminal device is to be reselected.

Based on the above scheme, the session management network element may send the user plane path information of the terminal device to the application function network element under the condition that the edge application server of the terminal device is to be reselected, so that the application function network element may reselect the edge application server for the terminal set according to the user plane path information.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the session management network element receives a user plane path information request message from the application function network element, the user plane path information request message comprising an identification of the terminal device.

Based on the above scheme, the session management network element may send the user plane path information of the terminal device to the application function network element according to the request of the application function network element.

With reference to the second aspect, in certain implementations of the second aspect, the user plane path information includes DNAI.

Based on the above scheme, the session management network element may carry DNAI in the user plane path information in order to indicate different user plane paths to the application function network element.

With reference to the second aspect, in some implementations of the second aspect, the user plane path information further includes a transmission delay corresponding to the DNAI, where the transmission delay corresponding to the DNAI is less than or equal to a threshold.

Based on the above scheme, the session management network element may carry DNAI and a transmission delay corresponding to DNAI in the user plane path information, so that the application function network element may select an edge application server for the terminal set according to the transmission delay.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the session management network element determines that the transmission delay corresponding to the DNAI is less than or equal to a threshold.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the session management network element sends a message to the data management network element or the application function network element, where the message is used to indicate that the terminal device or the edge application server of the terminal set is to be reselected.

Based on the above scheme, the session management network element may send a message to the data management network element or the application function network element to indicate that the terminal device or the edge application server of the terminal set is to be reselected.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the session management network element receives a subscription message from the data management network element, the subscription message being for subscribing to a reselection notification of the terminal device or an edge application server of the set of terminals.

Or, the subscription message is used for subscribing to the edge server switching notification of the terminal equipment or the terminal set, or, the subscription message is used for subscribing to the waiting reselection notification of the edge application server of the terminal equipment or the terminal set.

Based on the above scheme, the data management network element can subscribe the session management network element to the reselection notification of the terminal device or the edge application server of the terminal set, so that when the terminal device or the edge application server of the terminal set is to be reselected, the session management network element can send a message to the data management network element to indicate.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the session management network element sends a subscription message to the data management network element, the subscription message being used for subscribing to a reselection notification of an edge application server of the terminal set.

Based on the above scheme, the session management network element may subscribe the data management network element to the reselection notification of the edge application server of the terminal set, so when the edge application server of the terminal set is to be reselected, the data management network element may notify the session management network element.

With reference to the second aspect, in some implementations of the second aspect, the user plane path information is information of granularity of the terminal set.

Based on the above scheme, the session management network element may provide the user plane path information of the terminal set granularity to the application function network element, that is, the user plane path information may be the user plane path information of a plurality of terminal devices in the terminal set, so that the application function network element may determine the edge application server for the terminal set according to the user plane path information.

In a third aspect, a method for selecting an edge application server is provided, which may be performed by a core network element, or may also be performed by a component (such as a chip or a circuit) of the core network element, which is not limited to this, and for convenience of description, will be described below by taking a data management network element as an example.

The method may include: the data management network element receives an edge application server reselection indication message from a first session management network element, wherein the edge application server reselection indication message is used for indicating an edge application server of the first terminal equipment or a terminal set to be reselected, the first session management network element is a network element for providing services for the session of the first terminal equipment, and the first terminal equipment belongs to the terminal set; the data management network element sends an edge application server reselection notification message to a second session management network element, wherein the edge application server reselection notification message comprises an identifier of the terminal set, the edge application server reselection notification message is used for indicating that an edge application server of the terminal set is to be reselected, the second session management network element is a network element for providing services for a session of a second terminal device, and the second terminal device is a terminal device except the first terminal device in the terminal set.

Based on the above scheme, when the data management network element determines that the edge application server of the first terminal device or the terminal set is to be reselected according to the message from the first session management network element, the session management network element (i.e., the second session management network element) corresponding to other terminal devices except the first terminal device in the terminal set may be notified to the edge application server of the terminal set that is to be reselected.

Through the scheme, when any one of the terminal devices in the terminal set needs to reselect the edge application server, the session management network element of the terminal device in the terminal set can receive the notification message, so that the user plane path information of the terminal device can be reported to the application function network element according to the notification message, and the application function network element can select the edge application server for the terminal set.

The data management network element herein may be a unified data management network element, or a unified data storage network element, etc.

With reference to the third aspect, in certain implementations of the third aspect, before the receiving the message from the first session management network element, the method further includes: the data management network element sends a subscription message to the first session management network element, the subscription message being used for subscribing to a reselection notification of the first terminal device or an edge application server of the terminal set.

Based on the above scheme, the data management network element may subscribe the first session management network element to a reselection notification of the first terminal device or the edge application server of the terminal set, so when the first terminal device or the edge application server of the terminal set is to be reselected, the first session management network element may send a message to the data management network element to indicate.

With reference to the third aspect, in certain implementations of the third aspect, before sending the edge application server reselection notification message, the method further includes: the data management network element receives a subscription message from the second session management network element, the subscription message being for subscribing to a reselection notification of an edge application server of the set of terminals.

Based on the above scheme, the second session management network element can subscribe the data management network element to the reselection notification of the edge application server of the terminal set, so that when the edge application server of the terminal set is to be reselected, the data management network element can notify the second session management network element.

With reference to the third aspect, in certain implementations of the third aspect, the method further includes: the data management network element determines the second session management network element according to the information of the terminal set.

Based on the above scheme, after the data management network element receives the message of the first session management network element, it may be determined that, in the terminal set, terminal devices other than the first terminal device are second terminal devices according to the information of the terminal set, and the session management network element corresponding to the second terminal device is a second session management network element.

With reference to the third aspect, in some implementations of the third aspect, the information of the terminal set includes an identifier of the terminal set, and identifiers of all terminal devices in the terminal set.

Based on the above scheme, the information of the terminal set includes the identifier of the terminal set and the identifiers of all the terminal devices in the terminal set, so that the data management network element can determine the second session management network element according to the information of the terminal set.

In a fourth aspect, a method for selecting an edge application server is provided, where the method may be performed by an application function network element, or may also be performed by a component (such as a chip or a circuit) of the application function network element, and this is not limited, and for convenience of description, an application function network element is described below as an example.

The method may include: the application function network element receives a message from a session management network element, wherein the message is used for indicating an edge application server of a terminal set to be reselected, and the session management network element is a network element for providing service for a session of terminal equipment in the terminal set; the application function network element selects a first edge application server for the terminal set according to the user plane path information of the terminal equipment in the terminal set.

Based on the above scheme, when the application function network element determines that the edge application server of the terminal set is to be reselected according to the information from the session management network element, the application function network element may select the edge application server for the terminal combination according to the user plane path information of the terminal device in the terminal set. Therefore, the application function network element comprehensively considers the user plane path information of a plurality of terminal devices in the terminal set to select an edge application server for the terminal set, so that the service experience of the terminal devices in the terminal set after the edge application server is switched is ensured.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the message includes: user plane path information of terminal devices in the terminal set.

Based on the above scheme, the application function network element can acquire the user plane path information of the terminal equipment in the terminal set from the message sent by the session management network element, so that the edge application server can be selected for the terminal set according to the user plane path information of the terminal equipment in the terminal set.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the method further includes: the application function network element obtains user plane path information of the terminal equipment in the terminal set from the session management network element.

Based on the above scheme, the application function network element can obtain the user plane path information of the terminal equipment in the terminal set through the session management network element after receiving the message from the session management network element, so that the edge application server can be selected for the terminal set according to the user plane path information of the terminal equipment in the terminal set.

With reference to the fourth aspect, in some implementations of the fourth aspect, the user plane path information includes DNAI, which includes DNAI of the edge application server.

Based on the above scheme, the user plane path information includes DNAI. The application function network element selects an edge application server for the terminal set in the edge application servers corresponding to the DNAI, so that the edge application server can meet the service requirements of terminal equipment in the terminal set.

With reference to the fourth aspect, in some implementations of the fourth aspect, the user plane path information further includes a transmission delay corresponding to the DNAI, and the transmission delay corresponding to the DNAI corresponding to the first edge application server is less than or equal to a threshold.

Based on the above scheme, the user plane path information includes DNAI and a transmission delay corresponding to DNAI. And the application function network element selects an edge application server for the terminal set from the edge application servers corresponding to the DNAI according to the transmission time delay, wherein the transmission time delay corresponding to the DNAI corresponding to the selected edge application server is smaller than or equal to a set threshold value.

With reference to the fourth aspect, in certain implementations of the fourth aspect, before the application function network element receives the message from the session management network element, the method further includes: the application function network element receives an edge application service acquisition request message from terminal equipment, wherein the terminal equipment belongs to the terminal set; the application function network element sends a session management network element reselection request message to the session management network element according to the information of the terminal set, wherein the session management network element reselection request message comprises the identification of the terminal set and the identification of the terminal equipment in the terminal set, and the session management network element reselection request message is used for requesting the terminal equipment to be reselected to the session management network element.

Based on the above scheme, when the terminal device in the terminal set requests to the application function network element to acquire the edge application service, the application function network element may instruct the session management network element corresponding to the terminal device in the terminal set to switch the terminal device in the terminal set to the session management network element.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the method further includes: the application function network element sends the identifier of the terminal set and the identifier of the terminal equipment in the terminal set to the session management network element.

Based on the above scheme, the application function network element may send the information of the terminal set to the session management network element, so that the session management network element may determine the user plane path information for the terminal set according to the information of the terminal set.

In a fifth aspect, a method of selecting an edge application server is provided, the method comprising: the network storage function network element receives a first query request message from a first session management network element, wherein the first session management network element is a network element for providing service for a session of first terminal equipment, the first terminal equipment belongs to a terminal set, the first query request message comprises an identifier of the terminal set and/or an identifier of terminal equipment in the terminal set, and the query request message is used for requesting to query the session management network element serving the terminal equipment in the terminal set; the network storage function network element determines the session management network element; the network storage function network element sends a first query response message to the first session management network element, the first query response message including an identification of the session management network element.

Based on the above scheme, the network storage function network element can select a session management network element for the terminal set according to the request of the first session management network element, and indicate the selected session management network element to the first session management network element, so that the first session management network element can switch the first terminal device to the session management network element, thereby facilitating the session management network element to perform unified management on the terminal devices in the terminal set and improving the working efficiency.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the method further includes: the network storage function network element stores the corresponding relation between the session management network element and the terminal set.

Based on the above scheme, after the network storage function network element selects the session management network element for the terminal set, the identifier of the selected session management network element can be locally stored for subsequent use, so that the condition that other terminal devices in the subsequent terminal set need to acquire the session management network element is avoided, and the session management network element does not need to be re-determined again, so that resources are saved.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the method further includes: the network storage function network element determines the session management network element according to the identification of the terminal set and the corresponding relation.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the method further includes: the network storage function network element receives a second query request message from a second session management network element, wherein the second session management network element is a network element for providing service for a session of a second terminal device, the second terminal device belongs to the terminal set, the second query request message comprises an identifier of the terminal set, and the second query request message is used for requesting to search the session management network element capable of serving the terminal device in the terminal set; the network storage function network element sends a second query response message to the second session management network element, the second query response message including an identification of the session management network element.

Based on the above scheme, when the network storage function network element receives the session management network element search request message of the session management network element corresponding to the other terminal devices except the first terminal device in the terminal set, the network storage function network element can indicate the session management network element determined for the terminal set to the session management network elements, so that the terminal devices in the terminal set can be switched to the session management network element, and the session management network element can uniformly manage the terminal devices in the terminal set, thereby improving the working efficiency.

In a sixth aspect, a method of selecting an edge application server is provided, the method comprising: the method comprises the steps that a session management network element sends a query request message to a network storage function network element, wherein the session management network element is a network element for providing service for a session of terminal equipment, the terminal equipment belongs to a terminal set, the query request message comprises an identifier of the terminal set and an identifier of the terminal equipment in the terminal set, and the query request message is used for requesting to search the session management network element serving the terminal equipment in the terminal set; the session management network element receives a query response message from the network storage function network element, wherein the query response message comprises an identifier of the session management network element; and the session management sends a session reestablishment request message to the terminal equipment, wherein the session reestablishment request message comprises the identification of the session management network element.

Based on the above scheme, the first session management network element corresponding to the first terminal device in the terminal set can acquire the information of the session management network element through the network storage function network element, and access the session management network element through the session reestablishment flow, so that the terminal device in the terminal set can be managed by one session management network element in a unified way, and the working efficiency is improved.

With reference to the sixth aspect, in certain implementations of the sixth aspect, the method further includes: the session management network element receives a session management network element switching request message from an application function network element, wherein the session management network element switching request message comprises an identifier of the terminal set and an identifier of a terminal device in the terminal set, and the session management network element switching request message is used for indicating the session management network element to switch the terminal device to the session management network element capable of serving the terminal device in the terminal set.

Based on the above scheme, the first session management network element can obtain the information of the session management network element from the storage function network element according to the indication of the application function network element, and access the session management network element through the session reconstruction process, so that the terminal equipment in the terminal set can be uniformly managed by one session management network element, and the working efficiency is improved.

In a seventh aspect, there is provided an apparatus for selecting an edge application server, the apparatus being configured to perform any of the methods provided in the first to sixth aspects above. In particular, the apparatus may comprise means and/or modules, such as processing modules and/or communication modules, for performing the methods provided in the first to sixth aspects. In one implementation, the apparatus is a network device, e.g., the apparatus is an application function network element, or a session management network element, or a data management network element, or a network storage function network element. When the apparatus is a network device, the communication module may be a transceiver, or an input/output interface; the processing module may be a processor.

In another implementation, the apparatus is a chip, a system-on-chip, or a circuit for use in a network device. When the apparatus is a chip, a system-on-chip or a circuit used in a communication device, the communication module may be an input/output interface, an interface circuit, an output circuit, an input circuit, a pin or related circuit, etc. on the chip, the system-on-chip or the circuit; the processing module may be a processor, a processing circuit, a logic circuit, or the like.

In a possible case, the device is a chip, a system of chips or a circuit in an application-function network element. In this case, the apparatus may comprise means and/or modules, such as a processing unit and/or a communication unit, for performing the method provided in the first or fourth aspect.

Yet another possibility is that the device is a chip, a system-on-chip or a circuit in a session management network element. In this case, the apparatus may comprise means and/or modules, such as a processing module and/or a communication module, for performing the method provided in the second or sixth aspect.

In yet another possibility, the device is a chip, a system-on-chip or a circuit in a data management network element. In this case, the apparatus may comprise means and/or modules, such as a processing module and/or a communication module, for performing the method provided by the third aspect.

In a further possibility, the device is a chip, a system-on-chip or a circuit in a network element of a network storage function. In this case, the apparatus may comprise means and/or modules, such as a processing module and/or a communication module, for performing the method provided by the third aspect.

Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input/output interface may be an input/output circuit.

In an eighth aspect, there is provided an apparatus for selecting an edge application server, the apparatus comprising: a memory for storing a program; a processor for executing a memory-stored program, the processor being for performing any one of the methods provided in the first to sixth aspects above, when the memory-stored program is executed.

In a ninth aspect, the present application provides a processor configured to perform the method provided in the above aspects. In executing these methods, the process of transmitting the above information and acquiring/receiving the above information in the above methods can be understood as a process of outputting the above information by a processor and a process of receiving the above information inputted by the processor. When outputting the information, the processor outputs the information to the transceiver for transmission by the transceiver. This information, after being output by the processor, may also require additional processing before reaching the transceiver. Similarly, when the processor receives the input of the above information, the transceiver acquires/receives the above information and inputs it to the processor. Further, after the transceiver receives the information, the information may need to be further processed and then input to the processor.

Based on the above principle, for example, the reception request message mentioned in the foregoing method may be understood as information that the processor receives input.

With respect to operations such as transmitting, transmitting and acquiring/receiving, etc., which are referred to by a processor, unless otherwise specified, or if not contradicted by actual or inherent logic in the relevant description, operations such as outputting and receiving, inputting, etc., by the processor are more generally understood as being operations such as transmitting, transmitting and receiving, etc., rather than directly by radio frequency circuitry and antennas.

In implementation, the processor may be a processor dedicated to performing the methods, or may be a processor that executes computer instructions in a memory to perform the methods, e.g., a general purpose processor. The memory may be a non-transitory (non-transitory) memory, such as a Read Only Memory (ROM), which may be integrated on the same chip as the processor, or may be separately provided on different chips, and the type of the memory and the manner of providing the memory and the processor are not limited in this embodiment of the present application.

In a tenth aspect, there is provided a computer readable storage medium storing program code for execution by a device, the program code comprising instructions for performing any one of the methods provided in the first to sixth aspects above.

In an eleventh aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform any of the methods provided in the first to sixth aspects above.

In a twelfth aspect, there is provided a chip comprising a processor and a communication interface through which the processor reads instructions stored on a memory, performing any of the methods provided in the first to sixth aspects above.

Optionally, as an implementation manner, the chip may further include a memory, where the memory stores instructions, and the processor is configured to execute the instructions stored on the memory, where the instructions, when executed, are configured to perform any of the methods provided in the first aspect to the sixth aspect.

In a thirteenth aspect, a communication system is provided, which includes one or more of the foregoing application function network element, session management network element, first session management network element, second session management network element, and data management network element.

Drawings

Fig. 1 shows a schematic diagram of a network architecture.

Fig. 2 shows a schematic diagram of an edge computation scenario.

Fig. 3 is a schematic diagram of a method 300 for selecting an edge application server according to an embodiment of the present application.

Fig. 4 is a schematic diagram of a path before and after switching of an edge application server according to an embodiment of the present application.

Fig. 5 is a schematic flow chart diagram of a method 500 for selecting an edge application server according to an embodiment of the present application.

Fig. 6 is a schematic flow chart diagram of another method 600 of selecting an edge application server provided by an embodiment of the present application.

Fig. 7 is a schematic flow chart diagram of another method 700 of selecting an edge application server provided by an embodiment of the present application.

Fig. 8 is a schematic flow chart diagram of another method 800 of selecting an edge application server provided by an embodiment of the present application.

Fig. 9 shows a schematic block diagram of an apparatus 10 for selecting an edge application server according to an embodiment of the present application.

Fig. 10 shows a schematic block diagram of another apparatus 20 for selecting an edge application server according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions in the present application will be described below with reference to the accompanying drawings. The specific method of operation in the method embodiment may also be applied to the device embodiment or the system embodiment. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the various embodiments of the application, if there is no specific description or logical conflict, terms and/or descriptions between the various embodiments are consistent and may reference each other, and features of the various embodiments may be combined to form new embodiments according to their inherent logical relationships.

The technical solution of the embodiment of the application can be applied to various communication systems, for example: fifth generation (5th generation,5G) systems or New Radio (NR) or long term evolution (long term evolution, LTE) systems, etc. The technical scheme provided by the application can also be applied to future communication systems, such as a sixth generation mobile communication system. The technical solutions of the embodiments of the present application may also be applied to device-to-device (D2D) communication, vehicle-to-device (V2X) communication, machine-to-machine (machine to machine, M2M) communication, machine type communication (machine type communication, MTC), and internet of things (internet of things, ioT) communication systems or other communication systems.

To facilitate understanding of the embodiments of the present application, a communication system to which the embodiments of the present application are applicable will be briefly described with reference to fig. 1.

As an exemplary illustration, fig. 1 (a) shows a schematic architecture diagram of a 5G system 100a to which the embodiments of the present application are applicable. As shown in (a) of fig. 1, the network architecture may include, but is not limited to, the following network elements (alternatively referred to as functional network elements, functional entities, nodes, devices, etc.):

user Equipment (UE), (radio) access network equipment (radio access network, (R) AN), user plane function (user plane function, UPF) network elements, edge application servers (edge application server, EAS), access and mobility management functions (access and mobility management function, AMF) network elements, session management functions (session management function, SMF) network elements, network opening functions (network exposure function, NEF) network elements, EASDF network elements, network storage functions (NF repository function, NRF) network elements, policy control functions (policy control function, PCF) network elements, application functions (application function, AF) network elements, unified data management (unified data management, UDM) network elements, and the like.

The following briefly describes each network element shown in (a) in fig. 1:

1. User equipment: may be referred to as a terminal device (terminal equipment), a terminal apparatus, an access terminal, a subscriber unit, a subscriber station, a Mobile Station (MS), a Mobile Terminal (MT), a remote station, a remote terminal, a mobile device, a subscriber terminal, a wireless communication device, a user agent, or a subscriber apparatus. The terminal device may be a device providing voice/data connectivity to a user, e.g., a handheld device with wireless connectivity, an in-vehicle device, etc. Currently, some examples of terminals may be: a mobile phone (mobile phone), a tablet (pad), a computer with wireless transceiver function (e.g., a notebook, a palm, etc.), a mobile internet device (mobile internet device, MID), a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in an industrial control (industrial control), a wireless terminal in an unmanned (self-drive), a wireless terminal in a telemedicine (remote medical), a wireless terminal in a smart grid (smart grid), a wireless terminal in a transportation security (transportation safety), a wireless terminal in a smart city (smart city), a wireless terminal in a smart home (smart home), a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol, SIP) phone, a wireless local loop (wireless local loop, WLL) station, a personal digital assistant (personal digital assistant, PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a wireless terminal in a wearable device, a land-based device, a future-mobile terminal in a smart city (smart city), a public network (35G) or a future mobile communication device, etc.

Furthermore, the terminal device may also be a terminal device in an internet of things (internet of things, ioT) system. IoT is an important component of future information technology development, and its main technical feature is to connect an item with a network through a communication technology, so as to implement man-machine interconnection and an intelligent network for object interconnection. IoT technology may enable massive connectivity, deep coverage, and terminal power saving through, for example, narrowband (NB) technology.

In addition, the terminal device may further include an intelligent printer, a train detector, and the like, and the main functions include collecting data (part of the terminal device), receiving control information of the network device and downstream data, and transmitting electromagnetic waves to transmit upstream data to the network device.

It should be appreciated that the user equipment may be any device that can access the network. And the terminal equipment and the access network equipment can communicate with each other by adopting a certain air interface technology.

Alternatively, the user equipment may be used to act as a base station. For example, the user equipment may act as a scheduling entity that provides side-uplink signals between user equipments in V2X or D2D, etc. For example, a cellular telephone and a car communicate with each other using side-link signals. Communication between the cellular telephone and the smart home device is accomplished without relaying communication signals through the base station.

2. (radio) access network device: the system is used for providing network access functions for authorized user equipment in a specific area and can use transmission tunnels with different service qualities according to the level of the user equipment, the service requirements and the like.

The (R) AN can manage radio resources, provide access services for the ue, and further complete forwarding of control signals and ue data between the ue and the core network.

The access network device in the embodiments of the present application may be any communication device with a wireless transceiver function for communicating with a user device. The access network device includes, but is not limited to, an evolved Node B (eNB) or 5G, such as NR, a gNB in a system, or a transmission point (TRP or TP), one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system, or may also be a network Node, such as a baseband unit (BBU), or a Distributed Unit (DU), etc., that forms the gNB or the transmission point.

In some deployments, the gNB may include a Centralized Unit (CU) and DUs. The gNB may also include an active antenna unit (active antenna unit, AAU). The CU implements part of the functionality of the gNB and the DU implements part of the functionality of the gNB. For example, the CU is responsible for handling non-real time protocols and services, implementing the functions of the radio resource control (radio resource control, RRC), packet data convergence layer protocol (packet data convergence protocol, PDCP) layer. The DUs are responsible for handling physical layer protocols and real-time services, implementing the functions of the radio link control (radio link control, RLC), medium access control (media access control, MAC) and Physical (PHY) layers. The AAU realizes part of physical layer processing function, radio frequency processing and related functions of the active antenna. Since the information of the RRC layer may eventually become information of the PHY layer or be converted from the information of the PHY layer, under this architecture, higher layer signaling, such as RRC layer signaling, may also be considered to be transmitted by the DU or by the du+aau. It is understood that the access network device may be a device comprising one or more of a CU node, a DU node, an AAU node. In addition, the CU may be divided into access network devices in an access network (radio access network, RAN), or may be divided into access network devices in a Core Network (CN), which is not limited in this application.

3. User plane functional network element: the user plane functional network element mainly comprises the following functions: data packet routing and transmission, packet detection, traffic reporting, quality of service (quality of service, qoS) handling, lawful interception, uplink packet detection, downlink data packet storage, and other user plane related functions.

Illustratively, the UPFs can be divided into protocol data unit session anchor UPF (protocol data unit session anchor UPF, PSA UPF) and upstream classifier function UPF (uplink classifier functionality UPF, UL CL UPF).

The UPF shown in (a) in FIG. 1 is a PSA UPF, which is a UPF supporting a PDU session anchor function, and the UE is connected with the AMF through an N1 interface; the AN is connected with the AMF through AN N2 interface and connected with the PSA UPF through AN N3 interface; the PSA UPF is connected with the SMF through an N4 interface; the PSA UPF interfaces with EAS via an N6 interface.

Hereinafter, for simplicity of description, PSA UPF may be simply referred to as PSA; UL CL UPF may be simply referred to as UL CL.

The user plane function network element in the 5G architecture may be a UPF network element in a future communication system, or may have other names, which is not limited in this application.

4. Edge application server: EAS is an application server deployed in EDN for providing Edge Computing (EC) services.

The edge application may also be referred to as an "application instance," and may specifically refer to an instance (instance) of a server application (e.g., social media software, augmented reality (augmented reality, AR), virtual Reality (VR)) deployed to run on an edge data network (edge data network, EDN). An application (or service as well) may deploy one or more EAS in one or more EDNs, deploying EAS running in different EDNs may be considered as different EAS of an application, they may share a domain name, or may use different domain names with applications deployed on the cloud, where the domain name may be a fully qualified domain name (fully qualified domain name, FQDN), may use an anycast IP address, or may use different IP addresses.

It is to be appreciated that EAS may also be referred to as edge applications (servers), application instances, edge application instances, multiple access edge computing (MEC) applications (servers), EAS functions, and the like.

The EDN may be a local part of DN (local data center), the EDN including an edge enabled server (edge enabler server, EES) and a plurality of EAS's, each EDN having a particular service area.

5. Access and mobility management function network elements: the mobility management network element mainly comprises the following functions: access and mobility related functions such as connection management, mobility management, registration management, access authentication and authorization, reachability management, security context management, etc.

The access and mobility management function network element, which is called in the 5G architecture, may still be an AMF network element in a future communication system, or may have other names, which is not limited in this application.

6. Session function management network element: the session management network element may be a network element that provides services for a session of the UE, mainly for session management, network interconnection protocol (internet protocol, IP) address allocation and management of terminal devices, selection of termination points for manageable user plane functions, policy control and charging function interfaces, and downlink data notification.

In future communication systems, the session management function element may still be an SMF element, or may have other names, which is not limited in this application.

7. Network element with open function: it can be understood that the capability open network element is named in the 5G architecture. The capability opening network element mainly comprises the following functions: the services and the capabilities provided by the safe open 3GPP network function are internally opened or opened to a third party and the like; converting or translating information interacting with AF and information interacting with internal network functions, such as AF service identification and internal 5G core network information such as data network names (data network name, DNN), single network slice selection assistance information (single network slice selection assistance information, S-NSSAI), etc.

8. EAS discovery function network element: the primary responsibility for discovering EAS includes functions to register with the NRF for discovery and selection, process DNS messages according to the SMF's instructions (e.g., receive DNS message processing rules sent by the SMF, send DNS messages to a local DNS server or a central DNS server, add ECS option for DNS query message, exchange DNS messages sent by the UE, notify the SMF of EASDF related information, etc.), terminate DNS security, etc.

9. Network storage function network element: it is understood that the naming of network storage function network elements in a 5G architecture. Wherein, the network storage function network element mainly comprises the following functions: service discovery function, maintaining NF text of available Network Function (NF) instances and services they support.

10. Policy control function network element: a unified policy framework for guiding network behavior, providing policy rule information for control plane function network elements (e.g., AMF, SMF network elements, etc.), and the like.

In future communication systems, the policy control function network element may still be a PCF network element, or may have other names, which is not limited in this application.

11. Application function network element: the data route for application influence provides application layer information, and can interact with the policy framework or directly interact with the policy framework to perform policy decision request control and the like through accessing the network element with an open function of the network.

In future communication systems, the application function network element may still be an AF network element, or may have other names, which is not limited in this application.

12. Unified data management network element: it is understood that the naming of the network elements in the 5G architecture is unified. Wherein, unified data management network element mainly includes following function: unified data management, authentication credentials handling in 3GPP authentication and key agreement mechanisms, user identity handling, access authorization, registration and mobility management, subscription management, short message management, etc.

In future communication systems, the unified data management network element may still be a UDM network element, or may have other names, which is not limited in this application.

As an exemplary illustration, fig. 1 (b) shows a schematic architecture diagram of another 5G system 100b to which the embodiments of the present application are applicable. The system 100b shown in (b) of fig. 1 is different from the system 100a shown in (a) of fig. 1 in that: the 5G system in system 100a shown in fig. 1 (a) does not provide access to EAS through UL CL/BP, and the 5G system in system 100b shown in fig. 1 (b) provides access to EAS through UL CL/BP. As shown in (b) of fig. 1, the network architecture may include, but is not limited to, the following network elements (alternatively referred to as functional network elements, functional entities, nodes, devices, etc.):

UE, (R) AN, UPF, EAS, central DN, AMF network element, SMF network element, NEF network element, EASDF network element, NRF network element, PCF network element, AF network element, UDM network element, etc.

The network elements included in (b) in fig. 1 and the connections between the network elements are similar to (a) in fig. 1, and are not repeated, except that:

1. the UPF shown in (b) of FIG. 1 includes a UL CL UPF (alternatively referred to as a Branching Point UPF (BPUPF)), a local PSA UPF (local PSA UPF, L-PSA UPF), and a center PSA UPF (Central PSA UPF, C-PSA UPF).

The UL CL UPF is a UPF with an uplink classifier function. The UE is connected with the AMF through an N1 interface; the AN is connected with the AMF through AN N2 interface and connected with the UL CL UPF through AN N3 interface; the UL CL UPF is connected with the SMF through an N4 interface and connected with the PSA UPF through an N9 interface; the SMF is respectively connected with the PSA UPF through an N4 interface; the C-PSA UPF is connected with a central DN through an N6 interface; the L-PSA UPF interfaces with the EAS through the N6 interface.

2. The architecture shown in fig. 1 (b) includes a center DN in addition to EAS.

It will be appreciated that the network elements or functional network elements described above may be either network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform).

In the network architecture shown in fig. 1, the network elements may communicate through interfaces shown in the figure, and part of the interfaces may be implemented by adopting a non-service interface manner. As shown in fig. 1, the UE and the AMF may interact through an N1 interface, and the interaction Message may be referred to as an N1 Message (N1 Message), for example. The interaction between the RAN and the AMF may be performed through an N2 interface, and the N2 interface may be used for sending non-access stratum (NAS) messages, etc. Interaction between RAN and UPF may be performed through an N3 interface, and the N3 interface may be used to transfer data of the user plane, etc. The SMF and the UPF may interact through an N4 interface, where the N4 interface may be used to transmit information such as tunnel identification information of the N3 connection, data buffer indication information, and a downlink data notification message. Interaction between the UPF and DN can be performed through an N6 interface, and the N6 interface can be used for transmitting data of a user plane and the like.

In addition, each network element of the control plane function in fig. 1 may also communicate through a service interface, for example, the AMF accesses the service architecture through the Namf interface to provide a corresponding service; the SMF accesses the service architecture through the Nsmf interface to provide corresponding service; similarly, the NRF, PCF and AF access the service architecture through respective corresponding interfaces to provide corresponding services, which are not described herein. The relationship between the other interfaces and the network elements is shown in fig. 1, and is not described in detail here for the sake of brevity.

It should be understood that the network architecture applicable to the embodiments of the present application is merely an exemplary illustration, and the network architecture applicable to the embodiments of the present application is not limited thereto, and any network architecture including the functions capable of implementing the respective network elements described above is applicable to the embodiments of the present application.

It should also be understood that AMF, SMF, UPF, PCF and the like shown in fig. 1 can be understood as network elements for implementing different functions, e.g. can be combined into network slices as desired. The network elements may be independent devices, may be integrated in the same device to implement different functions, or may be network elements in hardware devices, may be software functions running on dedicated hardware, or may be virtualized functions instantiated on a platform (for example, a cloud platform), where the specific form of the network elements is not limited in this application.

It should also be understood that the above designations are merely defined to facilitate distinguishing between different functions and should not be construed as limiting the present application in any way. The present application does not exclude the possibility of employing other naming in 5G networks as well as other networks in the future. For example, in a 6G network, some or all of the individual network elements may follow the terminology in 5G, possibly by other names, etc.

It should also be understood that the names of interfaces between the network elements in fig. 1 are only an example, and the names of interfaces in the specific implementation may be other names, which are not specifically limited in this application. Furthermore, the names of the transmitted messages (or signaling) between the various network elements described above are also merely an example, and do not constitute any limitation on the function of the message itself.

In the edge computing deployment scenario, multiple UEs in the same UE set may need the same EAS to provide services to keep the traffic synchronized, and improve the user experience. If one or more UEs in the UE set need to reselect EAS (or need to perform EAS handover), in this case, how to allow the reselected EAS to still serve multiple UEs in the UE set is a current problem to be solved.

In order to facilitate understanding of the technical solutions of the embodiments of the present application, before describing the solutions of the embodiments of the present application based on a 5G architecture, some terms or concepts in 5G that may be related to the embodiments of the present application will be first described briefly.

1. 5G architecture.

The evolved packet system (evolved packet system, EPS) defined in the third generation partnership project (3rd generation partnership project,3GPP) includes a 5G network architecture based on a servitization interface or a 5G network architecture based on a point-to-point interface, and the 5G network can be divided into three parts, namely a UE, a DN, and an operator network.

The operator network may include one or more network elements shown in fig. 1 except for the UE and the DN, or may further include other network elements, which are not limited to the 5G network structure in the present application, and reference may be made to the description in the related art.

2. Edge computation

The rapid development of mobile communication promotes continuous emergence of various new services, besides the traditional mobile broadband and the internet of things, the mobile communication has spawned a plurality of new application fields such as augmented reality (augmented reality, AR) technology, virtual Reality (VR) technology, internet of vehicles technology, industrial control, IOT and the like, and simultaneously, higher demands are also put forward on the performance of network bandwidth, time delay and the like, and the network load is further increased.

Traditional centralized anchor deployment in LTE is increasingly difficult to support for rapidly growing mobile traffic models. On one hand, in the network with centralized deployment of anchor gateways, the increased flow is finally concentrated at the gateways and the core machine room, and higher requirements are put on the backhaul network bandwidth, the machine room throughput and the gateway specification; on the other hand, a long-distance backhaul network from an access network to an anchor gateway and a complex transmission environment result in a large delay and jitter of user message transmission.

Based on the above, the industry proposes Edge Computing (EC). By moving down the user plane network element and the service processing capability to the network edge, the edge calculation realizes the local processing of distributed service flow, and avoids the excessive concentration of the flow, thereby greatly reducing the specification requirements on a core machine room and a concentrated gateway. Meanwhile, the distance of the backhaul network is shortened by edge calculation, and the end-to-end transmission delay and jitter of the user message are reduced, so that the deployment of ultra-low delay service is possible.

FIG. 2 is a schematic diagram of an edge computation scenario. Compared to DN networks, edge computing platforms are deployed at a submerged UPF (i.e., a local UPF); the DN network is deployed at the remote UPF. The path for the UE to access the edge computing platform (as shown by the dash-dot line) is greatly shortened compared to the path for the UE to access the DN (as shown by the solid line). Thus, edge computing techniques may provide low latency, high bandwidth services to users.

The scenario in which the embodiment of the present application can be applied is described above in conjunction with fig. 1, and basic concepts involved in the present application are also briefly described, and a method for selecting an edge application server provided in the present application will be described in detail below in conjunction with the accompanying drawings.

The embodiments shown below are not particularly limited to the specific structure of the execution body of the method provided in the embodiment of the present application, as long as the communication can be performed by the method provided in the embodiment of the present application by running the program recorded with the code of the method provided in the embodiment of the present application, and for example, the execution body of the method provided in the embodiment of the present application may be a core network device or a functional module in the core network device that can call the program and execute the program.

In order to facilitate understanding of the embodiments of the present application, the following description is made.

First, in this application, "for indicating" may be understood as "enabling" which may include direct enabling and indirect enabling. When describing that a certain information is used to enable a, it may be included that the information directly enables a or indirectly enables a, and does not necessarily represent that a is carried in the information.

In the specific implementation process, the information to be enabled may be enabled in various ways, for example, but not limited to, the information to be enabled may be directly enabled, such as the information to be enabled itself or an index of the information to be enabled. The information to be enabled may also be indirectly enabled by enabling other information, where an association exists between the other information and the information to be enabled. It is also possible to enable only a part of the information to be enabled, while other parts of the information to be enabled are known or agreed in advance. For example, the enabling of specific information may also be implemented by means of a pre-agreed (e.g., protocol-specified) arrangement sequence of the respective information, thereby reducing the enabling overhead to some extent. And meanwhile, the universal parts of the information can be identified and enabled uniformly, so that the enabling expense caused by independently enabling the same information is reduced.

Second, the first, second, and various numerical numbers (e.g., "#1", "#2", etc.) shown in the present application are for convenience of description only, and are not intended to limit the scope of the embodiments of the present application for distinguishing objects. For example, distinguishing between different messages, etc. Rather than to describe a particular order or sequence. It is to be understood that the objects so described may be interchanged under appropriate circumstances so as to be able to describe aspects other than the embodiments of the application.

Third, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or apparatus.

Fourth, in this application, "pre-configured" may include pre-defined, e.g., protocol definitions. The "pre-defining" may be implemented by pre-storing a corresponding code, a table, or other means that may be used to indicate the relevant information in the device (including, for example, each network element), and the specific implementation of the present application is not limited herein.

Fifth, references to "save" in embodiments of the present application may refer to saving in one or more memories. The one or more memories may be provided separately or may be integrated in an encoder or decoder, processor, or communication device. The one or more memories may also be provided separately in part, and integrated in the decoder, processor, or communication device. The type of memory may be any form of storage medium, and this application is not limited in this regard.

Sixth, the "protocol" referred to in the embodiments of the present application may refer to a standard protocol in the field of communications, and may include, for example, a 5G protocol, a New Radio (NR) protocol, and related protocols applied in future communication systems, which are not limited in this application.

The method for discovering an edge application server provided in the embodiment of the present application is described in detail below by taking interaction between network elements as an example. It is to be understood that the terms and steps in the various embodiments of the application may be referenced to each other.

Fig. 3 is a schematic flow chart of a method for selecting an edge application server provided in an embodiment of the present application.

Fig. 3 (a) shows an exemplary flow of one possible method for selecting an edge application server, the flow shown in fig. 3 comprising the steps of:

S301, an application function network element receives a message from a first session management network element.

Illustratively, the first session management network element sends a message to the application function network element. The first session management network element is a network element that provides services for a session of the first terminal device, or the first session management network element is a session management network element to which the first terminal device has access. The first terminal device belongs to a terminal set. The terminal set may comprise a plurality of terminal devices.

Alternatively, the first session management network element may send the message to the application function network element in case the trigger condition is met.

The triggering condition may be, for example: the data transmission delay of the first terminal device does not meet the user plane delay requirement, where the user plane delay requirement is used to indicate the maximum delay allowed by the user plane transmission, or the user plane delay requirement indicates the threshold of the user plane transmission delay, so that the triggering condition herein may also be expressed that the data transmission delay of the first terminal device is greater than or equal to the threshold. It should be understood that the user plane delay requirement (or threshold) herein may be configured to the first session management network element by the application function network element before S301, or the user plane delay requirement (or threshold) herein may be configured to the session management network element corresponding to all the terminal devices in the terminal set by the application function network element before S301. It should be appreciated that the first session management network element may also send a message to the application function network element under other triggering conditions (e.g. when the server fails), which is not limited in this application.

Correspondingly, the application function network element receives the message from the first session management network element. The message is used for indicating that the edge application server of the first terminal device is to be reselected, or the message is used for indicating that the edge application server is to be reselected for the first terminal device, where the edge application server is to be reselected means that one edge application server is to be reselected to provide services for the first terminal device. It should be understood that the edge application server here is to be reselected, so to speak, that the edge application server is to be switched, etc., i.e. the message may indicate that the edge application server of the first terminal device is to be switched. It should be understood that the message indicates that the edge application server is to be reselected, or specifically the message indicates that the user plane path of the first terminal device is to be reselected, or the message indicates that the data transmission delay of the first terminal device does not meet the user plane delay requirement, or the message indicates that the data transmission delay of the first terminal device is greater than or equal to a threshold, or the message indicates that the load of the first terminal device is greater than or equal to a threshold, or the like.

S302, the application function network element obtains first user plane path information of the first terminal equipment and second user plane path information of the second terminal equipment.

The application function network element may receive the message from the first session management network element, and may obtain the first user plane path information of the first terminal device and the second user plane path information of the second terminal device in a certain manner, where the second terminal device is a terminal device other than the first terminal device in the terminal set. Specifically, the second terminal device is all terminal devices except the first terminal device in the terminal set. The second terminal device may include one or more terminal devices, which are not limited in this application.

The user plane path information in the present application may be user plane information for determining EAS. In particular, the information of the user plane path application side endpoint, such as the potential location of the application (which can be represented by DNAI); the user plane path information may also include delay corresponding to DNAI, etc.

For convenience of explanation, in the embodiment of the present application, the user plane path information includes DNAI as an example, but it should be understood that the user plane path information may be DNAI.

In some implementations, the first user plane path information and the second user plane path information may be used to determine an edge application server for the set of terminals.

First, an exemplary implementation manner of the application function network element to obtain the first user plane path information of the first terminal device is described.

In one example, in S301, the first session management network element sends a message to the application function network element, and carries first user plane path information in the message. That is, the first session management network element may send the first user plane path information to the application function network element through the message of S301. The application function network element may obtain the first user plane path information from the message. It should be understood that, when the first user plane path information has the above-mentioned effect of indicating that the edge application server of the first terminal device is to be reselected, the application function network element may further determine that the edge application server of the first terminal device is to be reselected according to the first user plane path information, or determine that the user plane delay of the first terminal device cannot meet the user plane delay requirement according to the first user plane path information, or determine that the load of the first terminal device is greater than or equal to a threshold according to the first user plane path information, or the like.

In another example, in S301, the first session management network element sends a message to the application function network element, where the message carries indication information, where the indication information is used to indicate that an edge application server of the first terminal device is to be reselected. According to the indication information, the application function network element sends a user plane path information request message to the first session management network element, wherein the user plane path information request message comprises an identifier of the first terminal equipment, and the first session management network element sends first user plane path information to the application function network element according to the user plane path information request message. The application function network element receives the first user plane path information from the first session management network element.

Alternatively, the first user plane path information may include information of one or more user plane paths, for example, the first user plane path information may include a first DNAI, which is a DNAI corresponding to the one or more user plane paths, or otherwise associated with the one or more user plane paths. Optionally, the first user plane path information may further include a transmission delay corresponding to the first DNAI. It should be understood that, the transmission delay herein refers to a transmission delay of a user plane path corresponding to a first DNAI, where the first DNAI corresponds to the transmission delay, and it refers to that the first DNAI has an association with the transmission delay, or that the first DNAI corresponds to the same user plane path with the transmission delay.

The manner in which the first session management network element obtains the first user plane path information is exemplarily described below.

For convenience of explanation, the embodiment of the present application describes the first session management network element determining the first user plane path information according to the user plane transmission delay of the first terminal device on different user plane paths as an example, but it should be understood that the first session management network element may also determine the first user plane path information according to other information (for example, the load of the first terminal device), which is not limited in this application. Specifically, for example, the first session management network element estimates the data transmission delay of the first terminal device on different user plane paths according to the position of the first terminal device, network topology, deployment information of an edge application server, and the like, or the first session management network element measures the data transmission delay of the first terminal device on different user plane paths by using a measurement data packet, so as to finally obtain one or more user plane paths of the first terminal device meeting the user plane delay requirement. In one implementation, the first session management network element includes information of a user plane path of the first terminal device that meets a user plane delay requirement in the first user plane path information, that is, the first user plane path information may include only information of the user plane path that meets the user plane delay requirement; in another implementation manner, the first session management network element may include information of all available user plane paths of the first terminal device in the first user plane path information, and carry transmission delays corresponding to the user plane paths in the first user plane path information.

An exemplary implementation of the application function network element to obtain the second user plane path information of the second terminal device is described below.

In one implementation (denoted as mode 1), the application function network element requests to a second session management network element to obtain second user plane path information of the second terminal device, where the second session management network element is a network element that provides services for a session of the second terminal device.

Illustratively, after the application function network element receives the message from the first session management network element in S301, the application function network element determines information of other terminal devices in the terminal set except the first terminal device according to information of the terminal set (for example, the application function network element locally stores information of the terminal set). The information of the terminal set includes one or more of the following: the identifier of the terminal set, the identifier of the terminal equipment in the terminal set, and the identifier of the session management network element corresponding to the terminal equipment in the terminal set. Specifically, the terminal set may include identifiers of all terminal devices in the terminal set and identifiers of session management network elements corresponding to all terminal devices.

If the information of the terminal set includes the identifier of the terminal set, the identifier of the terminal device in the terminal set, and the identifier of the session management network element corresponding to the terminal device in the terminal set, the application function network element may determine that the second terminal device is a terminal device other than the first terminal device in the terminal set according to the information of the terminal set, and the second session management network element is a network element that provides a service for a session of the second terminal device. Then, the application function network element sends a user plane path information request message to the second session management network element, the user plane path information request message including an identification of the second terminal device.

If the information of the terminal set includes the identifier of the terminal set, and the identifier of the terminal equipment in the terminal set, the application function network element may determine that the second terminal equipment is the terminal equipment except the first terminal equipment in the terminal set according to the information of the terminal set. The application function network element may then send a user plane path information request message to the second session management network element via the network capability opening function network element. For example, the application function network element provides the identifier of the second terminal device and the identifier of the service flow to the network capability openness function network element, so that the network capability openness function network element can determine the second session management network element corresponding to the second terminal device according to the identifier of the second terminal device and the identifier of the service flow, and then the network capability openness function network element can forward the user plane path information request message from the application function network element to the second session management network element.

The ue path information request message is used for requesting, from the second session management network element, information of a ue path of the second terminal device that meets a ue delay requirement, or the ue path information request message is used for requesting information of ue paths available to the second terminal device and delays corresponding to the ue paths.

Optionally, if the application function network element has already obtained the first user plane path information before sending the user plane path information request message to the second session management network element (e.g., the application function network element obtains the first user plane path information from the message in S301), the application function network element may determine information of the user plane path to be selected according to the first user plane path information, and carry the information of the user plane path to be selected in the user plane path information request message. For example, the first user plane path information includes a first DNAI, where the user plane paths corresponding to the first DNAI all meet the user plane delay requirement, and the application functional network element may carry the first DNAI as the DNAI to be selected in the user plane path request message; for another example, the first user plane path information includes a first DNAI and a transmission delay corresponding to the first DNAI, and the application functional network element determines a DNAI to be selected according to the transmission delay corresponding to the first DNAI, where the DNAI to be selected may include DNAI in the first DNAI, and the corresponding transmission delay satisfies a user plane delay requirement.

It should be understood that the application function network element locally stores the information of the terminal set, or, before the application function network element in the above scheme, pre-stores the information of the terminal set, or, the application function network element maintains the information of the terminal set. For example, after one terminal device in the terminal set registers in the network, or after a session is established, the session management network element serving the terminal device sends the identifier of the terminal device, the identifier of the terminal set (optionally including the identifier of the session management network element) to the application function network element, where the application function network element receives and stores the identifier of the terminal device and the identifier of the terminal set, optionally, the application function network element also stores the identifier of the session management network element, and these information have an association relationship.

Correspondingly, the second session management network element receives the user plane path information request message from the application function network element. And according to the user plane path information request message, the second session management network element sends second user plane path information to the application function network element.

Alternatively, the second user plane path information may include information of one or more user plane paths, for example, the first user plane path information may include a second DNAI, which is a DNAI corresponding to the one or more user plane paths. Optionally, the second user plane path information may further include a transmission delay corresponding to the second DNAI.

Specifically, for example, after the second session management network element receives the user plane path information request message, the second session management network element estimates the data transmission delay of the second terminal device on different user plane paths according to the position of the second terminal device, the network topology, the deployment information user plane delay requirement of the edge application server, and the like, or the second session management network element measures the data transmission delay of the second terminal device on different user plane paths by using a measurement data packet, finally one or more user plane paths of the second terminal device meeting the user plane delay requirement are obtained, and then the second session management network element sends the second user plane path information to the application function network element. In one implementation manner, the second session management network element includes information of a user plane path of the second terminal device that meets the requirement of user plane delay in the second user plane path information, that is, the second user plane path information may include only information of the user plane path that meets the requirement of user plane delay; in another implementation manner, the second session management network element may include information of all available user plane paths of the second terminal device in the second user plane path information, and carry transmission delays corresponding to the user plane paths in the second user plane path information.

Optionally, if the user plane path information request message carries information of a user plane path to be selected, for example, the user plane path information request message carries DNAI to be selected, the second session management network element may select, from the user plane paths corresponding to the DNAI to be selected, a user plane path that meets a user plane delay requirement of the second terminal device, that is, the second DNAI is included in the first DNAI. Therefore, in this case, the user plane path corresponding to the second DNAI satisfies both the user plane delay requirement of the first terminal device and the user plane delay requirement of the second terminal device.

In another implementation manner (denoted as mode 2), the data management network element may further trigger the second session management network element to send second user plane path information of the second terminal device to the application function network element.

Illustratively, in S303, the first session management network element sends an edge application server reselection indication message to the data management network element, where the edge application server reselection indication message is used to indicate that an edge application server of the first terminal device is to be reselected, or is used to indicate that an edge application server of the first terminal device is to be switched, or is used to indicate that a data transmission delay of the first terminal device cannot meet a user plane delay requirement, or is used to indicate that a transmission delay of the first terminal device is greater than or equal to a threshold, or is used to indicate that a load of the first terminal device is greater than or equal to the threshold.

The data management network element may for example be a UDM or a UDR in a 5G system. It should be appreciated that in future communication systems, such as 6G systems, the data management network element may also be another name, not limited herein.

Alternatively, the first session management network element may send the edge application server handover indication message to the data management network element if the trigger condition is met. The triggering condition herein may refer to the description of the S301 section, and will not be described in detail.

It should be understood that S303 may be performed after S301 or may be performed before S301, which is not limited in this application.

Optionally, before S303, the data management network element may send a subscription message to the first session management network element, where the subscription message is used to subscribe to a reselection notification of the first terminal device or the edge application server of the terminal set, which may be further described as: the subscription message is used for subscribing the notification that the data transmission delay of the first terminal device does not meet the requirement of the user plane delay, or the subscription message is used for subscribing the notification that the data transmission delay of the first terminal device is greater than or equal to a threshold value, or the subscription message is used for subscribing the notification that the load of the first terminal device is greater than or equal to the threshold value, and the like. That is, when the first terminal device or the terminal set needs to reselect the edge application server (specifically, when the data transmission delay of the first terminal device does not meet the user plane delay requirement, or when the data transmission delay of the first terminal device is greater than or equal to a threshold, or when the load of the first terminal device is greater than or equal to a threshold), the data management network element needs to be notified. For example, the data management network element sends a subscription message to the first session management network element, where the subscription message carries an identifier of the first terminal device or an identifier of the terminal set. Correspondingly, the first session management network element receives a subscription message from the data management network element, according to which, when the above-mentioned trigger condition is met, the first session management network element needs to notify the data management network element (e.g. sends an edge application server reselection indication message to the data management network element in S303).

It should be appreciated that the data management network element may also send a subscription message to the second session management network element for subscribing to a reselection notification by the second terminal device or an edge application server of the terminal set, see in particular the description of subscription messages sent to the first session management network element above. In other words, the data management network element may send the subscription message to the session management network elements corresponding to all the terminal devices in the terminal set, in which case, when the edge application server of any one of the terminal devices in the terminal set is to be reselected, the corresponding session management network element needs to be notified to the data management network element.

S304, the data management network element sends an edge application server reselection notification message to the second session management network element.

In an exemplary embodiment, after receiving the edge application server reselection indication message from the first session management network element, the data management network element sends an edge application server reselection notification message to the second session management network element, where the edge application server reselection notification message includes an identifier of the terminal set, the edge application server reselection notification message is used to indicate that an edge application server of the terminal set is to be reselected, or the edge application server reselection notification message is used to indicate that the second session management network element sends second user plane path information of the second terminal device, or the edge application server reselection notification message is used to indicate that the user plane path information of the terminal device in the terminal set is to be sent, or the edge application server reselection notification message is used to indicate that the second session management network element sends second user plane path information of the second terminal device to the application function network element, or the edge application server reselection notification message is used to indicate that the edge application server of the second terminal device is to be reselected. And the edge application server reselecting notification message is used for indicating that the transmission delay of the first terminal equipment is greater than or equal to a threshold value, the edge application server reselecting notification message is used for indicating that the transmission delay of the terminal equipment in the terminal set is greater than or equal to the threshold value, or the edge application server reselecting notification message is used for indicating that the load of the first terminal equipment is greater than or equal to the threshold value, or the edge application server reselecting notification message is used for indicating that the load of the terminal equipment in the terminal set is greater than or equal to the threshold value. It should be understood that the edge application server of the terminal set is to be reselected, which can also be said to be the edge server of the terminal set is to be switched.

Specifically, for example, after the data management network element receives the reselection indication information of the edge application server, it determines that the edge application server of the first terminal device is to be reselected, and the data management network element determines that the first terminal device belongs to the terminal set according to the locally stored information of the terminal set, and determines that the second terminal device is a terminal device other than the first terminal device in the terminal set, where the second session management network element is a network element that provides services for a session of the second terminal device, and then the data management network element sends the edge server reselection notification message to the second session management network element.

It should be understood that the data management network element locally stores the information of the terminal set, or the data management network element pre-stores the information of the terminal set before the above scheme. For example, after the first terminal device establishes the session, the first session management network element reports the identifier of the first terminal device to the data management network element, and carries the identifier of the terminal set. Correspondingly, the data management network element receives and stores the identifier of the first terminal device, the identifier of the terminal set and the identifier of the first session management network element, and the identifier of the first terminal device, the identifier of the terminal set and the identifier of the first session management network element have an association relationship. Similarly, after the second terminal device establishes the session, the second session management network element reports the identifier of the second terminal device to the data management network element, and carries the identifier of the terminal set. The data management network element receives and stores the information reported by the first session management network element and the second session management network element. Correspondingly, the data management network element receives and stores the identifier of the second terminal device, the identifier of the terminal set and the identifier of the second session management network element, and the identifier of the second terminal device, the identifier of the terminal set and the identifier of the second session management network element have an association relationship.

Optionally, before S303, the second session management network element may send a subscription message to the data management network element, where the subscription message is used for subscribing to a reselection notification of an edge application server of the terminal set, or may be said to be a change notification of information of a terminal device subscribed to the terminal set, or a notification that the subscription message is used for subscribing to a notification that an edge application server of the terminal device of the terminal set cannot meet a requirement, for example, a transmission delay of a terminal device existing in the terminal set is greater than or equal to a threshold, or a transmission delay of a terminal device existing in the terminal set is greater than or equal to a threshold.

That is, when the terminal set needs to reselect the edge application server, the data management network element notifies the second session management network element. For example, the second session management network element sends a subscription message to the data management network element, where the subscription message carries the identity of the terminal set. Correspondingly, the data management network element receives a subscription message from the first session management network element, according to the subscription message, when the data management network element determines that the edge application server of the terminal set is to be reselected (e.g., the data management network element receives an edge application server reselection indication message from the first session management network element in S303), the data management network element needs to notify the second session management network element (e.g., sends an edge application server reselection notification message to the second session management network element in S304).

It should be appreciated that the first session management network element may also send a subscription message to the data management network element for subscribing to a reselection notification of the edge application server of the set of terminals. In other words, the session management network elements corresponding to all the terminal devices in the terminal set send the subscription message to the data management, in which case, when the edge application server of the terminal set is to be reselected, the data management network element needs to notify the session management network elements corresponding to all the terminal devices in the terminal set. Correspondingly, the second session management network element receives the edge application server reselection notification message from the data management network element, and sends second user plane path information of the second terminal device to the application function network element according to the edge application server reselection notification message. Correspondingly, the application function network element obtains the second user plane path information from the second session management network element.

It should be understood that in the above solution, the first session management network element triggers the edge application server reselection procedure (or triggers the user plane path information reporting procedure of the terminal device in the terminal set) when the triggering condition is met (e.g., the transmission delay of the first terminal device is greater than or equal to the threshold). However, in some possible implementations, it is also possible that the above procedure is triggered by the application function network element. For example, when the load of the edge application server serving the terminal set is greater than or equal to a set threshold, the application function network element may request, according to the locally stored information of the terminal set, first user plane path information of the first terminal device and second user plane path information of the second terminal device from the first session management network element and the second session management network element, respectively.

S305, the application function network element selects a first edge application server for the terminal set according to the first user plane path information and the second user plane path information.

The application function network element, after obtaining the first user plane path information of the first terminal device and the second user plane path information of the second terminal device, selects an edge application server (here denoted as first edge application server) to serve the terminal set.

For example, if the first user plane path information includes a first DNAI and the second user plane path information includes a second DNAI, the application function network element determines a first edge application server according to the first DNAI and the second DNAI, where the first DNAI and the second DNAI each include a DNAI corresponding to the first edge application server. In other words, the first application function network element selects one of the edge application servers corresponding to the intersection of the first DNAI and the second DNAI as the first edge application server. When the intersection of the first DNAI and the second DNAI includes a plurality of DNAIs, the application functional network element may select the first edge application server from the edge application servers corresponding to the plurality of DNAIs according to an index metric selection algorithm, which is not limited in this application.

For another example, the first user plane path information includes a first DNAI and a transmission delay corresponding to the first DNAI, the second user plane path information includes a second DNAI and a transmission delay corresponding to the second DNAI, and the application function network element determines the first edge application server according to the first DNAI and the corresponding transmission delay thereof and the second DNAI and the corresponding transmission delay thereof, where the first DNAI and the second DNAI each include a DNAI corresponding to the first edge application server, and the transmission delay corresponding to the DNAI corresponding to the first edge application server is less than or equal to a threshold (or meets a user plane delay requirement). In other words, the first application function network element selects, from edge application servers corresponding to the intersection of the first DNAI and the second DNAI, an edge application server with a transmission delay meeting the user plane delay requirement as the first edge application server. If there are multiple edge application servers meeting the requirements, the application function network element may select the first edge application server from the multiple edge application servers according to an index measurement selection algorithm or the like, which is not limited in this application.

S306, the application function network element sends the edge application server switching message to the first session management network element and the second session management network element.

The application function network element, after selecting the first edge application server for the terminal set, sends an edge application server switching message to the first session management network element and the second session management network element, respectively, where the edge application server switching message includes information of the first edge application server. The edge application server handoff message may also be referred to as an edge application server reselection message or the like. In particular, the edge application server switch message is used to indicate a reselection to the first edge application server, which in turn is to be understood as the edge application server switch message is used to indicate a switch to the first edge application server.

Correspondingly, after the first session management network element or the second session management network element receives the edge application server switching message from the application function network element, the switching of the edge application server is performed, and the specific mode is not limited in the application.

Fig. 3 (b) shows another possible exemplary flow of a method for selecting an edge application server, the flow shown in fig. 3 (b) comprising the steps of:

s310, the session management network element sends user plane path information to the application function network element.

The session management network element is illustratively a network element that serves sessions of terminal devices in the terminal set. Specifically, the session management network element is a network element that provides services for sessions of all terminal devices in the terminal set. In some scenarios, the session management network element may be referred to as an anchor session management network element.

Optionally, the session management network element may send the user plane path information to the application function network element when the trigger condition is satisfied, where the user plane path information is information of granularity of a terminal set, or the user plane path information is user plane path information of terminal equipment in the terminal set. In one implementation, the user plane path information may be a set of user plane path information corresponding to different terminal devices in a terminal set, that is, in this implementation, the user plane path information includes a plurality of user plane path information, where the plurality of user plane path information corresponds to a plurality of terminal devices in the terminal set one by one; in another implementation, the user plane path information may be an intersection of user plane path information corresponding to different terminal devices in the terminal set, i.e. in this implementation, the user plane path information includes one or more user plane path information, which is user plane path information common to the user plane path information of multiple terminal devices in the terminal set.

The triggering condition may be, for example: the transmission delay of any one or more terminal devices in the terminal set does not meet the requirement of the user plane delay, or the transmission delay of any one or more terminal devices in the terminal set is greater than or equal to a threshold value, or the load of any one or more terminal devices in the terminal set is greater than or equal to the threshold value.

Alternatively, the user plane path information may include information of one or more user plane paths, for example, the user plane path information may include DNAI corresponding to the one or more user plane paths. Optionally, the user plane path information may further include a transmission delay corresponding to the DNAI.

Specifically, for example, when the trigger condition is met, the session management network element estimates the data transmission delay of the terminal device on different user plane paths according to the position, network topology, edge application server deployment information and the like of the terminal device in the terminal set, or the session management network element measures the data transmission delay of the terminal device on different user plane paths by using a measurement data packet, so as to finally obtain one or more user plane paths meeting the user plane delay requirement of the terminal device in the terminal set. In one implementation, the session management network element includes information of the user plane path meeting the user plane delay requirement in the user plane path information, that is, the user plane path information may include only information of the user plane path meeting the user plane delay requirement; in another implementation manner, the session management network element may include information of all available user plane paths in the user plane path information, and carry transmission delays corresponding to the user plane paths in the user plane path information.

It should be understood that the session management network element is a network element that serves sessions of terminal devices in a terminal set. The terminal equipment in the terminal set may select the same session management network element for the terminal equipment in the terminal set in the process of accessing to the network or establishing the session, or may switch the terminal equipment in the terminal set to the session management network element when the terminal equipment in the terminal set requests the edge computing service from the application function network element. The second case is exemplarily described below in connection with steps S320 to S370.

S320, the first session management network element sends a first query request message to the network storage function network element.

The first session management network element is, for example, a network element serving a session of a first terminal device belonging to the terminal set, or, in other words, any one of the terminal sets. The first query request message may include an identification of a terminal set and identifications of all terminal devices in the terminal set, and is used for requesting to query a session management network element serving the terminal devices in the terminal set.

Alternatively, the first session management network element may initiate the first query request message according to an indication of the application function network element. For example, the terminal device in the terminal set sends an edge application server acquisition request message to the application function network element, and according to the edge application server acquisition request message, the application function network element sends a session management network element (including the first session management network element) for providing services for the session of the terminal device in the terminal set, where the session management network element reselection request message includes an identifier of the terminal set and an identifier of the terminal device in the terminal set, and the session management network element reselection request message is used to request the terminal device in the terminal set to be switched to the session management network element. After receiving the session management network element request message, the first session management network element sends the first query request message to the network storage function network element.

S330, the network storage function network element determines a session management network element.

For convenience of explanation, the first session management network element will be described herein by taking as an example that the first session management network element first requests to the network storage function network element to query the session management network element. That is, the network storage function network element first receives the first query request message from the first session management network element. According to the first inquiry request message, the network storage function network element determines a session management network element for the terminal set, and the session management network element can provide service for terminal equipment in the terminal set. The specific manner of determining the session management network element for the terminal set by the network storage function network element is not limited in the application.

Optionally, the network storage function element stores an identity of the session management element, the identity of the session management element being associated with an identity of the set of terminals.

S340, the network storage function network element sends a first inquiry response message to the first session management network element.

The network storage function network element, after determining a session management network element for the set of terminals, sends a first query response message to the first session management network element, the first query response message comprising an identification of the session management network element.

S350, the second session management network element sends a second query request message to the network storage function network element.

The second session management network element is, for example, a network element serving a session of a second terminal device, which is a terminal device of the terminal set other than the first terminal device. The second query request message includes an identification of the set of terminals and an identification of terminal devices in the set of terminals. The second query request message is used for requesting to query session management network elements serving the terminal devices in the terminal set.

S360, the network storage function network element sends a second query response message to the second session management network element.

The network storage function network element receives a second query request message from a second session management network element, obtains information of the session management network element in a local storage according to the identifier of the terminal set, then sends a second query response message to the second session management network element, and carries the identifier of the session management network element in the second query response message.

Or in another implementation manner, the network storage function network element may determine the session management network element for the terminal set after receiving the first query request message and the second query request message, which is not limited in this application.

S370, switching the session management network element.

The first session management network element, after receiving the first query response message from the network storage function network element, triggers the first terminal device to perform session reestablishment and instructs the session management network element to provide session service for the first terminal device so as to switch the first terminal device to the session management network element

Similarly, after receiving the second session inquiry response message, the second session management network element triggers session reestablishment of the second terminal device, and instructs the session management network element to provide session service for the second terminal device, so as to switch the second terminal device to the session management network element.

And S380, the application function network element selects a first edge application server for the terminal set according to the user plane path information.

Illustratively, after the application function network element receives the user plane path information from the session management network element, an edge application server (herein denoted as a first edge application server) is selected to serve the set of terminals.

For example, if the user plane path information includes DNAI, the application function network element determines a first edge application server according to the DNAI, where the DNAI includes DNAI corresponding to the first edge application server. In other words, the application function network element selects one of the edge application servers corresponding to the DNAI as the first edge application server. When the DNAI corresponds to a plurality of edge application servers, the application function network element may select a first edge application server from the plurality of edge application servers according to an index measurement selection algorithm, which is not limited in this application.

For another example, the first user plane path information includes DNAI and a transmission delay corresponding to the DNAI, and the application function network element determines the first edge application server according to the DNAI and the transmission delay corresponding to the DNAI, where the DNAI includes DNAI corresponding to the first edge application server, and the transmission delay corresponding to the DNAI corresponding to the first edge application server is less than or equal to a threshold (or meets a user plane delay requirement). In other words, the application function network element selects an edge application server with transmission delay meeting the requirement of user plane delay as a first edge application server from the edge application servers corresponding to the DNAI. If there are multiple edge application servers meeting the requirements, the application function network element may select the first edge application server from the multiple edge application servers according to an index measurement selection algorithm or the like, which is not limited in this application.

S390, the application function network element sends the edge application server switching message to the session management network element.

The application function network element sends an edge application server switching message to the session management network element after selecting a first edge application server for the terminal set, where the edge application server switching message includes information of the first edge application server, and the edge application server switching message is used to instruct switching of terminal devices in the terminal set to the first edge application server, or the edge application server switching message is used to instruct reselecting of terminal devices in the terminal set to the first edge application server.

Correspondingly, after receiving the edge application server switching message from the application function network element, the session management network element switches the edge application server, and the specific mode is not limited in the application.

In summary, in the above scheme, when the terminal set needs to switch (or reselect) the edge application servers, the application function network element comprehensively considers the user plane path information of all the terminal devices in the terminal set, and selects an appropriate edge application server to provide services for the terminal set, so as to ensure the service experience of the terminal set after switching the edge application servers.

In order to facilitate understanding of the solution provided by the embodiments of the present application, the reselection procedure of the edge application server of the embodiments of the present application is briefly described below with reference to fig. 4. Assume that a certain set of UEs includes UE1 and UE2, which require the same EAS to provide service. As shown in fig. 4 (a), UE1 and UE2 are served by EAS 1. However, when UE2 continues to be served by EAS1 due to a position shift (e.g., from the coverage of RAN2 to the coverage of RAN 1), its user plane transmission delay may not meet the user plane delay requirement, as shown in fig. 4 (b). At this time, the AF may consider the user plane path information of UE1 and UE2 in combination, and reselect one EAS (e.g., EAS2 in the figure) for UE1 and UE 2.

For ease of understanding, the EAS reselection process illustrated in fig. 4 will be described in detail below in connection with specific embodiments. It should be appreciated that AF in methods 500-800 described below may correspond to application function network elements in method 300, including method 300 (a) and method 300 (b), UE2 may correspond to a first terminal device in method 300, SMF2 may correspond to a first session management network element in method 300, UE1 may correspond to a second terminal device in method 300, SMF1 may correspond to a second session management network element in method 300, and UDR may correspond to a data management network element in method 300.

Fig. 5 illustrates an exemplary flowchart of a method 500 for selecting an edge application server provided by an embodiment of the present application.

For convenience of description, the session management function network element is an SMF in the 5G network, the application function network element is an AF in the 5G network, the terminal device is a UE, the access network device is a RAN in the 5G network, and the user plane function network element is a UPF in the 5G network, so that names of the network elements or devices are not limited in the embodiment of the present application, and other network elements capable of implementing corresponding functions are also within the protection scope of the present application.

As can be seen in fig. 5, the method 500 includes:

s501, UE1 and UE2 acquire service of EAS 1.

Illustratively, UE1 and UE2 belong to the same UE set, and UEs in the UE set need to access the same EAS, or, in other words, UEs in the UE set need to be served by the same EAS. The UE1 may comprise one or more UEs, that is, the set of UEs may comprise two or more UEs.

As an example, the UEs in the UE set may be multiple user devices in a multiplayer interactive game, where the multiple user devices may play a game simultaneously or together through matching, and the service architecture of such a game often consists of a login server and a service server, where the login server uniformly manages registration information, personal information, and the like of the user, and implements a grouping function when the game is matched. And the service server provides actual game service for the user after the user accesses the service server. In order to reduce the time delay and jitter in the game process, the MEC technology can be adopted to move down the user plane network element and the service processing capability to the network edge, so as to realize the local processing of distributed service flow, avoid the excessive concentration of the flow, and shorten the distance of the backhaul network, thereby reducing the time delay and jitter of the end-to-end transmission. In the scenario of multi-player games using MEC, the same edge application server EAS can be selected for different game users to ensure service synchronization and promote user experience. Multiple users of a matching game may be partitioned into a set of UEs, so that UEs in the set of UEs need to be serviced by the same EAS. It should be understood that the UE set herein may also be applied to other various scenarios, for example, the same vehicle formation may also constitute one UE set, which is not limited in this application. Any scenario in the prior art where transmission delay is reduced by selecting the same EAS for multiple UEs is applicable to the solutions provided by the embodiments of the present application.

It should be understood that the UE set may include two or more UEs, or may include 3 or more UEs, and the solution in this case should also be within the protection scope of the embodiments of the present application.

Thus, based on the above scenario, the AF needs to select the same EAS for UE1 and UE2 when UE1 and UE2 request to acquire edge calculation services.

Specifically, for example, UE1 and UE2 send edge calculation service request messages to AFs (which may be centralized AFs, for example), respectively, and the AFs select one EAS to provide edge calculation services for UE1 and UE2 according to the edge calculation service request messages of UE1 and UE 2. The AF may select EAS that serve UE1 and UE2 in combination with network topology, user plane path information, and the like, which is not specifically limited in this application.

Meanwhile, EAS selected by AF for UE1 and UE2 are denoted as EAS1 herein for convenience of explanation. It should be understood, however, that the various numbers of "1", "2", etc., or "first", "second", etc., before or after the various terms in this application are merely for distinguishing between similar objects and are not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are intended to designate identical objects, or different objects, and that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are capable of operation in other sequences than illustrated or otherwise described herein.

S502, AF sends user plane time delay requirement to SMF1 and SMF2 respectively.

Illustratively, the AF sends user plane delay requirements to SMF1 and SMF2, respectively, where SMF1 is the SMF that provides service to UE1, or SMF1 is the network element that provides service to the PDU session of UE 1. The SMF2 is an SMF that provides a service to the UE2, or, in other words, the SMF2 is a network element that provides a service to the PDU session of the UE 2.

The user plane delay requirement is used for indicating the maximum delay allowed by the user plane transmission, or the user plane delay requirement is used for indicating the threshold value of the user plane transmission delay. In order to guarantee user experience, the user plane transmission delay should not exceed the threshold.

The specific form in which the AF indicates the delay requirement of the user plane is not limited in this application. Only a few possible ways are given here: an example, the user plane delay requirement is 1 value (value), which occupies a field, and the value is carried in the existing bit for indicating the transmission delay; as another example, the user plane delay requirement includes an indication field (description) and a value (value), and two fields are occupied, where the description is used to indicate that the value is a user plane transmission delay threshold.

It should be understood that S502 may be performed after S501. For example, when the AF selects EAS1 for UE1 and UE2, and after UE1 and UE2 access EAS1, EAS1 may notify AF that UEs in the UE set have accessed, after the AF receives the notification message of EAS1, send the user plane delay requirement to SMF1 and SMF 2. Alternatively, S502 may be performed during S501 or before S501, and AF may determine to send the user plane delay requirement to UE1 and UE2 at any time after UE1 and UE2 establish a session with the network, which is not limited in this application.

It should also be appreciated that the AF may be that the information of the UE set is pre-saved prior to S502. For example, after all UEs in the UE set register to the network, or after all UEs in the UE set establish a session, the network side may send information of the UE set to the AF, and the AF receives and stores the information of the UE set. The information of the set of UEs includes an identity of the set of UEs, an identity of the UEs in the set of UEs, and an identity of network devices (particularly SMFs) to which the UEs in the set of UEs have access. For example, SMF1 and SMF2 send the identities of UE1 and UE2 (and carry the identity of the UE set) to the AF, respectively, and the AF receives and stores the association relationship between UE1, SMF1 and UE set, and the association relationship between UE2, SMF2 and UE set. Alternatively, EAS1 may send information of the set of UEs together to the AF when informing the AF that a UE in the set of UEs has been accessed. For another example, the AF may also acquire and save information of a UE set by itself after the UE in the UE set accesses a network service. For example, in a multiplayer interactive game scenario, the EAS is similar to a game server, the AF is similar to a login server, and after player matching is performed, the AF can obtain information of a UE set consisting of multiple game players. The several schemes described above are merely examples, and the present application is not limited thereto.

S503, when the transmission delay of the UE2 does not meet the user plane delay requirement, the SMF2 selects a user plane transmission path for the UE 2.

For example, when the UE in the UE set (i.e., UE1 and UE 2) acquires the edge computing service, and performs data transmission with EAS 1 through the established user plane path, SMFs (i.e., SMF 1 and SMF 2) corresponding to the UE in the UE set respectively measure the data transmission delay of the corresponding UE. If the data transmission delay of a UE cannot meet the user plane delay requirement (or the data transmission delay of a UE is greater than or equal to the threshold indicated by the user plane delay requirement), the adjustment of the user plane path, or the EAS reselection, is required.

For example, the data transmission delay becomes larger due to the position movement of the UE2, and when the SMF2 finds that the data transmission delay of the UE2 cannot meet the user plane delay requirement, the SMF2 reselects the user plane transmission path for the UE 2. For example, the SMF2 estimates the transmission delay of the UE2 on different user plane transmission paths according to the location of the UE2, network topology, EAS deployment information, user plane delay requirements, and the like, so as to obtain all user plane paths that meet the user plane delay requirements. For another example, the SMF2 may measure the user plane transmission delays of different user plane paths through a measurement packet, so as to obtain all the user plane paths meeting the delay requirement, and the specific mode is not limited in the application.

It should be understood that the above embodiment is described by taking an example that the UE2 is moved in position, so that the data transmission delay cannot meet the user plane delay requirement, and thus the user plane transmission path needs to be reselected, but the application is not limited thereto. In a different implementation, it may also be that the movement of other UEs in the UE set (or multiple UEs or all UEs in the UE set) results in the need to reselect the user plane transmission path; alternatively, the user plane transmission path may need to be reselected due to excessive load, unbalanced load, server failure, and the like, which is not limited in the present application.

If there is no user plane path satisfying the user plane delay requirement, the AF may send service failure notification to UE1 and UE2, and carry the cause value. If there is a user plane path that meets the user plane delay requirement, then:

at S504, SMF2 sends user plane path information #1 to the AF.

Illustratively, the user plane path information #1 may include information of one or more user plane paths, where the information of the one or more user plane paths may include DNAI, time delay, and other information of the one or more user plane paths, where the time delay represents a user plane path time delay estimated value when the UE2 obtains the edge computing service through the DNAI. In this implementation, the path information #1 may include only the information of the user plane paths that meet the user plane delay requirement, or may include the information of all the user plane paths available to the UE2 (i.e., may include the information of the user plane paths that meet the user plane delay requirement, or may include the information of the user plane paths that do not meet the user plane delay requirement).

Optionally, the UE path information #1 may also include no delay, or, in other words, the UE path information #1 may also include only DNAI, where DNAI is a DNAI of a UE path that meets a user plane delay requirement, or, in other words, the path information #1 may indicate that when the UE2 obtains an edge service through the DNAI, a user plane delay estimated value thereof meets the user plane delay requirement. In this implementation, the path information #1 includes only user plane path information that meets the user plane delay requirement.

It should be understood that, when there are multiple user plane paths that meet the user plane delay requirement, the user plane path information #1 may include all the information of the user plane paths that meet the user plane delay requirement, or may include only part of the user plane path information that meets the user plane delay requirement. For example, when there are a large number of user plane paths satisfying the user plane delay requirement, the SMF2 may include information of preferred several user plane paths only in the user plane path information # 1.

It should also be appreciated that when the user plane path information #1 includes information of a plurality of user plane paths, the SMF2 may sort the information of the plurality of user plane paths. For example, SMF2 orders the plurality of user plane paths from small to large in terms of user plane delay estimates so that AF can select a user plane path according to the order. The present application is not limited in this regard.

It should be appreciated that in one implementation, user plane path information #1 in S504 may correspond to the first user plane path information in method 300.

S505, the AF determines a user plane path list to be selected.

Illustratively, the AF receives the user plane path information #1 from the SMF2 and then determines a user plane path list to be selected from the user plane path information # 1.

For example, the user plane path information #1 includes DNAI for one or more user plane paths and estimated delays on the one or more user plane paths. And the AF determines a user plane path list to be selected according to the estimated time delay on the one or more user plane paths, wherein the user plane path list to be selected comprises DNAI of user plane paths with time delay meeting the requirement of the time delay of the user plane in the one or more user plane paths. And AF stores the user plane path list to be selected. Alternatively, the AF may determine the EAS list to be selected according to the user plane path list to be selected, where the EAS list to be selected includes information of one or more EAS, i.e., the AF may determine its corresponding one or more EAS according to DNAI in the user plane path list to be selected. The AF may save the EAS list to be selected.

For another example, the ue path information #1 includes DNAI of only one or more ue paths, and the list of ue paths to be selected includes DNAI of the one or more ue paths at this time, that is, in this case, the AF may directly compose the ue paths in the ue path information #1 into the list of ue paths to be selected.

S506, the AF sends a user plane path information acquisition request message to the SMF1.

For example, the AF determines, according to the locally stored information of the UE set, information of other UEs in the UE set except for the UE2, that is, UE1 and SMF1 corresponding to UE 1.

Then, the AF sends a user plane path information acquisition request message to the SMF1, where the user plane path information acquisition request message includes an identifier of the UE1, and the user plane path information acquisition request message is used to request to acquire information of a user plane path of the UE1, or the user plane path information acquisition request message is used to request to acquire user plane path information of the UE1 that meets a user plane delay requirement. It should be understood that if UE1 includes a plurality of UEs, the AF sends the user plane path information acquisition request message to a plurality of SMFs corresponding to the plurality of UEs, respectively.

Alternatively, if S506 is performed after the completion of S505, the AF may also carry the list of user plane paths to be selected acquired in S505 in the user plane path request message.

S507, SMF1 selects a user plane transmission path for UE 1.

S508, the SMF1 sends user plane path information #2 to the AF.

Illustratively, the SMF1 receives a user plane path information request message from the AF, selects a user plane transmission path for the UE1 according to the user plane path information request message, and transmits information of the selected user plane path (denoted as user plane path information # 2) to the AF.

In one implementation manner (denoted as a), the UE1 identifier is included in the UE1 path information request message, and then the SMF1 estimates the transmission delays of the UE1 on different user plane transmission paths according to the location of the UE1, network topology, EAS deployment information, user plane delay requirements, and the like, so as to obtain all the user plane paths that meet the user plane delay requirements. Or the SMF1 measures the transmission delay of the user plane of different user plane paths through the measurement data packet, so as to obtain all the user plane paths meeting the delay requirement. If the user plane path meeting the user plane delay requirement does not exist, the SMF2 sends indication information of user plane path selection failure to the AF and carries a cause value, wherein the cause value is used for indicating that the cause of the failure is that the user plane path meeting the user plane delay requirement does not exist. If there is a user plane path satisfying the user plane delay requirement, the SMF1 sends user plane path information #2 to the AF.

Illustratively, in such an implementation, the user plane path information #2 may include information of one or more user plane paths, where the information of the one or more user plane paths may include information of DNAI, time delay, etc. of the one or more user plane paths, where the time delay represents a user plane path time delay estimate when the UE1 obtains the edge computing service through the DNAI. In this implementation, the path information #1 may include only the information of the user plane paths that meet the user plane delay requirement, or may include the information of all the user plane paths available to the UE 1. Optionally, the UE path information #2 may also include no delay, or, in other words, the UE path information #2 may also include only DNAI, where DNAI is a DNAI of a UE path that meets a user plane delay requirement, or, in other words, the path information #2 may indicate that when the UE1 obtains an edge service through the DNAI, a user plane delay estimated value thereof meets the user plane delay requirement. In this implementation, the path information #2 includes only user plane path information that meets the user plane delay requirement.

In another implementation manner (denoted as the manner b), the UE1 identifier and the to-be-selected user plane path list are included in the user plane path information request message, and then the SMF1 determines, according to the location of the UE1, the network topology, and the like, a user plane path that meets the delay requirement from the user plane paths corresponding to the to-be-selected user plane path list. If the user plane path in the user plane path list to be selected does not have the user plane path meeting the user plane delay requirement, the SMF2 sends indication information of user plane path selection failure to the AF and carries a cause value, wherein the cause value is used for indicating that the cause of the failure is that the user plane path meeting the user plane delay requirement does not exist in the user plane path list to be selected. If the user plane path which meets the user plane delay requirement exists in the user plane path list to be selected, the SMF1 sends user plane path information #2 to the AF.

Illustratively, in such an implementation, the user plane path information #2 may include information of one or more user plane paths belonging to the list of user planes to be selected, and the information of the one or more user plane paths may include DNAI of the one or more user plane paths. Optionally, the ue path information #2 may further include a delay of the one or more ue paths, which is not limited in this application.

S509, the AF determines that EAS2 serves the set of UEs.

The AF receives the user plane path information #2 from the SMF2, and determines EAS serving the UE set (or UEs in the UE set) according to the user plane path information #2 (optionally, may also include the user plane path list to be selected determined by the AF in S505).

Illustratively, in the mode a, if the user plane path information #2 includes DNAI, delay, etc. information of one or more user plane paths, the AF determines a user plane path of the UE1 satisfying the user plane delay requirement in the one or more user plane paths, and then determines an EAS serving the UE set in combination with a user plane path list to be selected. It should be appreciated that in such an implementation, S505 may be performed after S508, which is not limiting in this application.

For example, the AF determines that UE1 meets the user plane delay requirement on two user plane paths corresponding to DNAI 1, DNAI 2. If the user plane path list to be selected determined by the AF in S505 includes DNAI 1, DNAI 2, DNAI 3, that is, the user plane path determined by the AF to meet the user plane delay requirement of UE2 is DNAI 1, DNAI 2, DNAI 3, the AF may select one of EAS corresponding to DNAI 1 or DNAI 2 to provide services for the UE set. It should be appreciated that the AF may select from EAS corresponding to DNAI 1 and DNAI 2 according to an index scale selection algorithm, which is not limited in this application.

Illustratively, in the mode b, if the user plane path information #2 includes DNAI of one or more user plane paths and does not include delay of the user plane path, it indicates that the user plane path in the user plane path information #2 is a user plane transmission path determined by the SMF1 in the list of user plane paths to be selected that the UE1 meets the requirement of the user plane delay, and the AF determines EAS serving the UE set according to the user plane path information # 2. For example, if the user plane path information #2 includes DNAI 1 and DNAI 2, the AF selects one of EAS corresponding to DNAI 1 or DNAI 2 to serve the UE set, and the specific manner is not limited in this application.

For convenience of explanation, the embodiment of the present application refers to EAS serving the UE set as EAS1 and EAS serving the UE set as EAS2, which is redetermined by the AF in S509, before reselecting the user plane path.

It should be appreciated that in one implementation, S509 may correspond to S305 in method 300 (a). EAS2 here may correspond to the first edge application server in method 300 (a).

S510, the AF performs context migration when running on the EAS1 and the EAS2.

Illustratively, the AF determines that the run-time context is migrated between EAS1 and EAS2 after selecting EAS2 to serve the UE set.

S511, the AF sends EAS switching indication information to SMF1 and SMF2, respectively.

Illustratively, the EAS switch indication information includes EAS2 information, such as DNAI, IP address, etc. corresponding to EAS2.

Correspondingly, SMF1 and SMF2 receive EAS handoff indication information from AF, respectively, and then SMF1 and SMF2 configure and activate new user plane paths for UE1 and UE2, respectively, in combination with the information of EAS2. After the new user plane path is activated, SMF1 and SMF2 send configuration complete messages to the AF, respectively. On the other hand, SMF1 and SMF2 provide information of EAS2 to the UE, respectively, for example, SMF1 and SMF2 transmit information of EAS2 to UE1 and UE2, respectively, through NAS messages of the control plane. Alternatively, the information of EAS2 may be provided to UE1 and UE2 by the AF through the application layer.

SMF1 and SMF2 release the original user plane resources, i.e. EAS 1 service UE1 resources and EAS 1 service UE2 resources, respectively.

In summary, in the above embodiments, the AF maintains information of the UE set. When any one UE in the UE set needs to perform EAS reselection, the SMF corresponding to the UE sends the user plane path information of the UE to the AF, and the AF can acquire the user plane path information of other UEs through the SMFs corresponding to other UEs in the UE set. Finally, AF comprehensively considers the user plane path information of all the UEs in the UE set, and selects a proper EAS to provide service for the UE set, thereby ensuring the service experience of the UE set after the EAS reselection.

Fig. 6 illustrates an exemplary flowchart of a method 600 of selecting an edge application server provided by an embodiment of the present application. As can be seen in fig. 6, method 600 includes:

s601, UE1 and UE2 acquire service of EAS 1.

Illustratively, UE1 and UE2 belong to the same UE set, and UEs in the UE set need to access the same EAS, or, in other words, UEs in the UE set need to be served by the same EAS. It should be appreciated that S601 is similar to S501 in method 500 and will not be described in detail for brevity.

S602, AF sends user plane delay requirement and UE set identification to SMF1 and SMF2 respectively.

Illustratively, the AF sends a user plane delay requirement and an identity of the UE set to SMF1 and SMF2, respectively, where the SMF1 is an SMF that provides services to UE1 and the SMF2 is an SMF that provides services to UE2, and the user plane delay requirement and the identity of the UE set may be carried in the same message. The UE set identifier refers to the identifier of the set in which UE1 and UE2 are located, and the user plane delay requirement may be used to indicate the maximum delay allowed by the user plane transmission, and specifically reference may be made to the description related to S502 of the method 500, which is not repeated here.

S603, SMF1 and SMF2 subscribe to the UDR for UE set change notification, respectively.

For example, SMF1 may request to the UDR, after receiving a user plane delay requirement from the AF and a UE set identity, to subscribe to a UE set change notification, e.g. SMF1 sends to the UDR a UE set change subscription request message including the identity of the UE set, the UE set change subscription request message being used to notify SMF1 when the UDR has a UE in the UE set that needs EAS reselection. The subscription request message may also include an identification of the traffic flow.

It should be understood that the UDR herein may also be other network elements, such as UDM, which is not limited in this application.

SMF2 performs similar to SMF1 and will not be repeated.

S604, UDR subscribes to the EAS reselection notification to SMF1 and SMF2, respectively.

Illustratively, after receiving subscription requests from SMF1 and SMF2, the UDR subscribes to the SMF1 and SMF2, respectively, for example, the UDR sends an EAS reselection subscription request message to the SMF1, the EAS reselection subscription request message including an identity of UE1, the EAS reselection subscription request message requesting that the SMF notify the UDR when the UE1 needs to perform an EAS reselection. The EAS reselection subscription request message may also include an identification of the traffic flow.

S605, SMF2 sends an EAS reselection notification to UDR.

Illustratively, when an EAS reselection to UE2 is required (e.g., when the data transmission delay of UE2 fails to meet the user plane delay requirement, the specific reason is not limited), SMF2 sends an EAS reselection notification message to the UDR, the EAS reselection notification message including an identity of UE2, and/or an identity of the set of UEs. The EAS reselection notification message is used to indicate that the UE2 needs to perform EAS reselection, or the EAS reselection notification message is used to indicate that the transmission delay of the UE2 cannot meet the user plane delay requirement. The EAS reselection notification message may include an identification of the traffic flow.

S606, the UDR sends a UE set change notification to the SMF 1.

For example, after receiving the EAS reselection notification message from the SMF2, the UDR determines that UEs other than the UE2 in the UE set are UE1 and the SMF corresponding to the UE1 is SMF1 according to the identifier (i.e., the identifier of the UE2 and/or the identifier of the UE set) carried in the EAS reselection notification message and the locally stored information of the UE set, and then the UDR sends a UE set change notification message to the SMF 1. The UE set change notification message may carry an identifier of the UE set and EAS reselection indication information, where the EAS reselection indication information is used to indicate that the UE set needs to perform EAS reselection; or, the UE set change notification message carries an identifier of the UE1 and EAS reselection indication information, where the EAS reselection indication information is used to indicate that the UE1 needs to perform EAS reselection.

The information for the set of UEs includes the identity of the set of UEs, as well as the identities of all UEs in the set of UEs (i.e., UE1 and UE 2), and the identities of the SMFs serving those UEs. It should be appreciated that UDR maintains information of the set of UEs in advance. For example, after the UE1 has established the PDU session, the SMF1 reports the identity of the UE1 to the UDR, while carrying the identity of the UE set. Correspondingly, the UDR receives and stores the identifier of the UE1, the identifier of the UE set, and the identifier of the SMF1, where the identifier of the UE1, the identifier of the UE set, and the identifier of the SMF1 have an association relationship. Similarly, after the UE2 has established the PDU session, the SMF2 reports the identity of the UE2 to the UDR, while carrying the identity of the UE set. The UDR receives and stores the information reported by SMF1 and SMF 2. Correspondingly, the UDR receives and stores the identification of the UE2, the identification of the UE set and the identification of the SMF2, and the identification of the UE2, the identification of the UE set and the identification of the SMF2 have an association relation.

As a specific example, after receiving the EAS reselection notification message from the SMF2, if the EAS reselection notification message includes the identifier of the UE2, the UDR determines that the SMF serving other UEs (i.e., UE 1) in the UE set except the UE2 is SMF1 according to the locally stored association relationship between the identifier of the UE2 and the identifier of the UE set and the association relationship between the identifier of the UE1, the identifier of the UE set and the identifier of the SMF1, and then the UDR sends a UE set change notification to the SMF 1.

S607, SMF2 sends user plane path information #1 to AF.

Illustratively, when an EAS reselection is required to UE2, SMF2 selects an available user plane transmission path for UE 2. For example, after UE2 establishes a user plane path and performs data transmission with EAS1, SMF2 measures the data transmission delay of UE 2. When the data transmission delay of the UE2 cannot meet the user plane delay requirement, the SMF2 reselects the user plane transmission path for the UE 2.

For example, the SMF2 estimates the transmission delay of the UE2 on different user plane transmission paths according to the location of the UE2, network topology, EAS deployment information, user plane delay requirements, and the like, so as to obtain all user plane paths that meet the user plane delay requirements. For another example, SMF2 may measure the user plane transmission delays of different user plane paths by using a measurement packet, so as to obtain all the user plane paths that meet the delay requirement.

Further, the SMF2 sends the user plane transmission path information #1 to the AF, where the user plane transmission path information #1 includes information of one or more user plane paths, and the information of the one or more user plane paths may include DNAI, time delay, and other information of the one or more user plane paths, where the time delay represents a user plane path time delay estimated value when the UE1 obtains the edge computing service through the DNAI. In this implementation manner, the path information #1 may include only the information of the user plane paths of the UE1 that meet the user plane delay requirement, or may include the information of all the user plane paths available to the UE 1. Optionally, the ue path information #1 may also not include delay, where DNAI in the ue path information #1 is DNAI of a ue path that meets the requirement of the ue delay. It should be understood that, when there are multiple user plane paths that meet the user plane delay requirement, the user plane path information #1 may include all the information of the user plane paths that meet the user plane delay requirement, or may include only part of the user plane path information that meets the user plane delay requirement. The present application is not limited.

It should be understood that S607 may be performed before S605, may be performed after S605, may be performed simultaneously with S605, and is not limited in this application.

S608, the SMF1 sends the user plane path information #2 to the AF.

Illustratively, after the SMF1 receives the UE set change notification message from the UDR, an available user plane transmission path is selected for the UE1 according to the EAS reselection indication information in the UE set change notification message.

The manner in which SMF1 selects the user plane path information for UE1 is similar to the manner in which SMF2 selects the user plane path information for UE2, and the description in S607 may be referred to specifically, and will not be repeated here.

Further, the SMF1 transmits user plane transmission path information #2 to the AF, the user plane transmission path information #2 including information of one or more user plane paths. The user plane path information #2 is similar to the user plane path information #1, except that the user plane path information #1 includes information of a user plane path selected by the SMF2 for the UE2, and the user plane path information #2 includes information of a user plane path selected by the SMF1 for the UE 1. For brevity, no further description is provided herein.

S609, the AF determines that EAS2 serves the UE set.

Illustratively, the AF determines the EAS to serve the UE set after receiving user plane path information #1 from SMF2 and user plane path information #2 from SMF 1. For example, if the user plane path information #1 includes DNAI 1, DNAI 2, and DNAI 3, and the user plane path information #2 includes DNAI 1 and DNAI 2, the AF may select one of EAS corresponding to DNAI 1 or DNAI 2 to serve the UE set. It should be appreciated that the AF may select from EAS corresponding to DNAI 1 and DNAI 2 according to an index scale selection algorithm, which is not limited in this application.

S610, AF performs run-time context migration for EAS1 and EAS 2.

S611, the AF sends EAS switching indication information to SMF1 and SMF2, respectively.

It should be appreciated that S610 and S611 are similar to S510 and S511 in method 500, and for brevity, the description will not be repeated.

To sum up, in the above embodiment, the UDR maintains information of the UE set. When any one UE in the UE set needs to perform EAS reselection, the SMF corresponding to the UE informs the UDR, and the UDR further informs the SMF corresponding to other UEs in the UE set. SMF corresponding to UE in the UE set reports user plane path information of the UE to AF respectively. The AF comprehensively considers the user plane path information of all the UEs in the UE set, selects a proper EAS to provide service for the UE set, and ensures the service experience of the UE set after the EAS reselection.

Fig. 7 illustrates an exemplary flowchart of a method 700 of selecting an edge application server provided by an embodiment of the present application. As can be seen in fig. 7, method 700 includes:

s701, UE1 and UE2 acquire service of EAS 1.

Illustratively, UE1 and UE1 belong to the same UE set, and UEs in the UE set need to access the same EAS, or, in other words, UEs in the UE set need to be served by the same EAS. The description of the UE set may refer to S501 in the method 500, and the description is not repeated here.

When UE1 and UE2 request to acquire edge computation services, the AF needs to select the same EAS for UE1 and UE2 (here, EAS1 is illustrated as an example). Meanwhile, the AF trigger network selects an anchor SMF to provide services for UE1 and UE2, and the specific process is not limited in this embodiment. It should be understood that, here, the anchor SMF refers to a network element that provides services for the session of UE1 and UE2, and in other scenarios, the anchor SMF may have other names, which is not limited in this application.

S702, AF sends user plane delay requirement, UE set identification, identification of UE1 and UE2 to anchor SMF.

Illustratively, after selecting the anchor SMF, or after UE1 and UE2 have accessed the anchor SMF, or after UE1 and UE2 have established a session on the anchor SMF, the AF sends a user plane delay requirement to the anchor SMF, along with an identification of the UE set, an identification of UE1 and UE 2.

It should be understood that the user plane delay requirement is similar to the user plane delay requirement described in S502 of the method 500, and detailed description thereof will be omitted herein, and specific reference to the related description in S502 is made.

S703, when the transmission delay of the UE2 cannot meet the user plane delay requirement, the anchor SMF selects a user plane path for the UE1 and the UE 2.

Illustratively, when UE1 and UE2 perform data transmission with EAS1 through the established user plane path, the anchor SMF measures the data transmission delay of UE1 and UE 2. If the data transmission delay of any UE of UE1 and UE2 cannot meet the user plane delay requirement, EAS reselection or user plane path adjustment is required. For example, the data transmission delay of the UE2 becomes larger due to the position movement, and when the SMF2 finds that the data transmission delay of the UE2 cannot meet the user plane delay requirement, the SMF2 reselects the user plane paths meeting the user plane delay requirement for the UE1 and the UE 2. For a specific manner, reference may be made to the manner in which the SMF2 described in S503 of the method 500 obtains the user plane path that satisfies the user plane delay requirement, which will not be described in detail herein.

If the user plane path meeting the user plane delay requirement does not exist, the anchor SMF sends indication information of user plane path selection failure to the AF and carries a cause value, wherein the cause value is used for indicating that the user plane path meeting the user plane delay requirements of the UE1 and the UE2 does not exist. If there is a user plane path that satisfies the user plane delay requirements of both UE1 and UE2, then

At S704, the anchor SMF transmits user plane path information #3 to the AF.

Illustratively, the anchor SMF selects a user plane path satisfying the user plane delay requirement for UE1 and UE2, respectively, and then carries information of the user plane path capable of satisfying the user plane delay requirements of UE1 and UE2 simultaneously in the user plane path information #3. For example, if the anchor SMF determines that the user plane paths that meet the user plane delay requirement of the UE1 include DNAI 1, DNAI 2, and DNAI 3, and the anchor SMF determines that the user plane paths that meet the user plane delay requirement of the UE2 include DNAI 2, DNAI 3, and DNAI4, the anchor SMF may carry DNAI 2 and DNAI 3 in the user plane path information #3, and simultaneously carry an identifier of the UE set, and send the user plane path information #3 to the AF.

It should be appreciated that in one implementation, S704 may correspond to S310 in method 300 (b).

S705, the AF determines that EAS2 serves the UE set.

The AF receives user plane path information #3 from the anchor SMF and determines EAS serving the set of UEs (or UEs in the set of UEs) based on the user plane path information # 3.

If the user plane path information #3 includes only DNAI of one user plane path, the AF determines that EAS (denoted as EAS 2) corresponding to the DNAI serves the UE set; if user plane path information #3 includes DNAI for multiple paths, the AF may select one of multiple EAS corresponding to the multiple DNAI to serve the UE set. It should be understood that the AF may select from a plurality of EAS corresponding to the plurality of DNAIs according to an index scale selection algorithm, which is not limited in this application.

S706, AF performs run-time context migration for EAS1 and EAS 2.

S707, the AF sends EAS switching indication information to SMF1 and SMF2, respectively.

It should be appreciated that S706 and S707 are similar to S510 and S511 in method 500, and the description is not repeated for brevity.

In summary, in the above embodiment, one anchor SMF serves UEs in the UE set. When any UE in the UE set needs to perform EAS reselection, the anchor SMF transmits user plane path information of the UE in the UE set to the AF. AF comprehensively considers user plane path information of UE in UE set, selects a proper EAS to provide service for the UE set, and ensures service experience of the UE set after EAS reselection.

Fig. 8 illustrates an exemplary flowchart of a method 800 for selecting an edge application server provided by an embodiment of the present application. As can be seen in fig. 8, method 800 includes:

s801, UE1 and UE2 request acquisition of edge computing services.

Illustratively, UE1 and UE2 belong to the same UE set, and UE1 respectively request edge computing services from the network.

S802, AF sends SMF indication information of the selected anchor point to SMF1 and SMF2 respectively.

Illustratively, if the AF determines that the same EAS needs to be selected to serve the UE set, the AF sends information to the core network at this time to instruct SMF1 and SMF2 to select an anchor SMF. For example, the AF sends the SMF1 a selection anchor SMF indication message, carrying the UE set identifier and all the UE identifiers in the UE set (denoted as UE identifiers, i.e. the UE1 and UE2 identifiers). The selected anchor SMF indication information is used to indicate that an anchor SMF is selected for a UE in the set of UEs.

Similarly, the AF sends the selected anchor SMF indication information to SMF2, carrying the UE set identity and the UE identity at the same time.

S803, SMF1 and SMF2 send anchor point seeking SMF request messages to NRF, respectively.

S804, the NRF sends a find anchor SMF response message to SMF1 and SMF2, respectively.

In one implementation, the NRF receives a find anchor SMF request message from SMF1, where the find anchor SMF request message includes an identifier of a UE set and an identifier of UE1, and the NRF determines an anchor SMF for all UEs in the UE set, and sends a find anchor SMF response message to SMF1, where the find anchor SMF response message carries the identifier of the anchor SMF. The NRF locally saves the identity of the anchor SMF, and the identity of the anchor SMF is associated with the identity of the set of UEs. In this implementation, after the NRF receives the anchor point SMF searching request message from the SMF2, and the anchor point SMF searching request message of the SMF2 includes the identifier of the UE set and the identifier of the UE2, the NRF may locally obtain the identifier of the anchor point SMF associated with the identifier of the UE set according to the identifier of the UE set, and then the NRF sends an anchor point SMF searching response message to the SMF2, where the anchor point SMF searching response message carries the identifier of the anchor point SMF.

In another implementation, the NRF receives a find anchor SMF request message from SMF1, the find anchor SMF request message including an identification of a set of UEs and an identification of all UEs in the set of UEs. After the NRF receives the anchor point searching SMF request message from the SMF2, the NRF determines an anchor point SMF for the UE in the UE set, and then sends anchor point searching SMF response messages to the SMF1 and the SMF2, respectively, where the anchor point searching SMF response message carries the identifier of the anchor point SMF.

It should be appreciated that other manners of selecting an anchor point for the UE set may be employed, and the present application is not limited. For example, the AF may indicate that the SMF corresponding to the UE that first requested the EAS service is NRF registered as an anchor SMF of the UE set, or the AF may arbitrarily indicate that the SMF corresponding to any one of UE1 and UE2 is NRF registered as an anchor SMF of the UE set. For example, according to the indication of AF, SMF1 registers as an anchor SMF of the UE set to NRF, after registration is successful, when SMF2 requests to query the anchor SMF to NRF, NRF indicates SMF1 as anchor SMF to SMF2; for another example, the NRF may take as the anchor SMF the SMF in the UE set that first requests to query the anchor SMF. For example, when the NRF receives the anchor point searching request message from the SMF1, the NRF takes the SMF1 as an anchor point SMF if the anchor point searching request message sent by the SMF corresponding to other UEs in the UE set is not received yet. In this case, SMF1 is indicated to SMF2 as an anchor SMF after the subsequent NRF receives the anchor seeking request message from SMF2 transmission.

S805, SMF1 and SMF2 trigger PDU session reestablishment procedure of UE1 and UE 2.

Illustratively, after receiving a find anchor SMF response message from the NRF, SMF1 triggers UE1 to perform PDU session reestablishment and instructs the anchor SMF to provide session management services. UE1 re-requests the edge computing service after the PDU session establishment on the anchor SMF is completed.

The SMF2 side scheme is similar to SMF1 and will not be described in detail here.

After selecting the anchor session management network element to provide session management services for UE1 and UE2, in one implementation, UE1 and UE2 re-request to obtain edge computing services, then AF sends a user plane delay requirement, and an identifier of a UE set, and identifiers of UE1 and UE2, to the anchor SMF in S806. The ue delay requirement is similar to the ue delay requirement described in S502 of the method 500, and will not be described herein, specifically, reference may be made to the description related to S502. In another implementation, the AF stores the edge calculation service requests of UE1 and UE2 received at S801. After PDU session reestablishment for UE1 and UE2 is completed, the anchor SMF indicates to the AF that the UEs in the UE set have successfully established a session, then:

in S806, the AF sends the user plane delay requirement to the anchor SMF, along with the identity of the UE set, the identities of UE1 and UE 2.

S807, the anchor SMF transmits user plane path information #3 to the AF.

Illustratively, when the transmission delay of UE2 fails to meet the user plane delay requirement, the anchor SMF selects a user plane path for UE1 and UE2 and provides user plane path information #3 to the AF, the user plane path information #3 including information of one or more user plane paths.

S808, the AF selects EAS1 to serve the UE set.

Illustratively, the AF receives user plane path information #3 from the anchor SMF, and selects an EAS (e.g., EAS 1) to serve the set of UEs based on the user plane path information #3. The specific implementation is not limited in this application.

In summary, in the above embodiment, all UEs in the UE set select one anchor SMF to provide services for the UE set. When the UE set needs to perform EAS reselection, the anchor SMF transmits user plane path information of the UE in the UE set to the AF. AF comprehensively considers user plane path information of UE in UE set, selects a proper EAS to provide service for the UE set, and ensures service experience of the UE set after EAS reselection.

Corresponding to the methods given by the above method embodiments, the embodiments of the present application also provide corresponding apparatuses, where the apparatuses include corresponding modules for performing the above method embodiments. The module may be software, hardware, or a combination of software and hardware. It will be appreciated that the technical features described in the method embodiments described above are equally applicable to the device embodiments described below.

Fig. 9 is a schematic block diagram of an apparatus for selecting an edge application server according to an embodiment of the present application. The device 10 comprises a transceiver module 11 and a processing module 12. The transceiver module 11 may be used to implement corresponding communication functions. The transceiver module 11 may also be referred to as a communication interface or a communication unit. The processing module 12 may be configured to implement a corresponding processing function, such as selecting a first edge application server for the terminal set according to the first user plane path information and the second user plane path information.

Optionally, the apparatus 10 may further include a storage module, where the storage module may be configured to store instructions and/or data, and the processing module 12 may read the instructions and/or data in the storage module, so that the apparatus implements the actions of the device or network element in the foregoing method embodiments.

In a first design, the apparatus 10 may be an application function network element in the foregoing embodiment, or may be a component (such as a chip) of the application function network element. The apparatus 10 may implement steps or processes corresponding to the execution of the application functions in the above method embodiments, where the transceiver module 11 may be configured to perform operations related to the transceiver of the application function network element in the above method embodiments, and the processing module 12 may be configured to perform operations related to the processing of the application function network element in the above method embodiments.

A first possible implementation manner, the transceiver module 11 is configured to receive a message from a first session management network element, where the message is used to instruct an edge application server of a first terminal device to reselect, and the first session management network element is a network element that provides services for a session of the first terminal device, and the first terminal device belongs to a terminal set;

a processing module 12, configured to obtain first user plane path information of the first terminal device and second user plane path information of a second terminal device, where the second terminal device is a terminal device in the terminal set other than the first terminal device; and selecting a first edge application server for the terminal set according to the first user plane path information and the second user plane path information.

Optionally, the first user plane path information includes a first data network access identifier DNAI, the second user plane path information includes a second DNAI, and the first DNAI and the second DNAI both include DNAI corresponding to the first edge application server.

Optionally, the first user plane path information further includes a transmission delay corresponding to the first DNAI, the second user plane path information further includes a transmission delay corresponding to the second DNAI, and the transmission delay corresponding to the DNAI corresponding to the first edge application server is less than or equal to a threshold.

Optionally, the transceiver module 11 is further configured to: and sending an edge application server switching message to the first session management network element and the second session management network element, wherein the edge application server switching message comprises information of the first edge application server, and the edge application server switching message is used for indicating switching to the first edge application server.

Optionally, the processing module 12 is specifically configured to: transmitting a user plane path information request message to a second session management network element according to the information of the terminal set, wherein the user plane path information request message comprises an identifier of the second terminal device, and the second session management network element is a network element for providing service for the session of the second terminal device; the transceiver module 11 is specifically configured to: and receiving the second user plane path information from the second session management network element.

Optionally, the processing module 12 is further configured to: and determining DNAI to be selected according to the first user plane path information, wherein the user plane path information request message also comprises the DNAI to be selected.

A second possible implementation manner, the transceiver module 11 is configured to receive a message from a session management network element, where the message is used to instruct an edge application server of a terminal set to reselect, and the session management network element is a network element that provides services for a session of a terminal device in the terminal set; and the processing module 12 is configured to select a first edge application server for the terminal set according to the user plane path information of the terminal device in the terminal set.

Optionally, the message includes: user plane path information of terminal equipment in the terminal set.

Optionally, the processing module 12 is further configured to: and obtaining the user plane path information of the terminal equipment in the terminal set from the session management network element.

Optionally, the user plane path information includes DNAI, which includes DNAI of the edge application server.

Optionally, the user plane path information further includes a transmission delay corresponding to the DNAI, and the transmission delay corresponding to the DNAI corresponding to the first edge application server is less than or equal to a threshold.

Optionally, the transceiver module 11 is further configured to: receiving an edge application service acquisition request message from terminal equipment, wherein the terminal equipment belongs to the terminal set; the processing module 12 is further configured to: according to the information of the terminal set, a session management network element reselection request message is sent to a first session management network element of the terminal device, wherein the session management network element reselection request message comprises an identifier of the terminal set and an identifier of a terminal device in the terminal set, and the session management network element reselection request message is used for requesting the terminal device to be reselected to the session management network element.

Optionally, the transceiver module 11 is further configured to: and sending the identification of the terminal set and the identification of the terminal equipment in the terminal set to the session management network element.

In a second design, the apparatus 10 may be a session management network element (e.g., a first session management network element or a second session management network element) in the foregoing embodiment, or may be a component (e.g., a chip) of the session management network element. The apparatus 10 may implement steps or procedures performed by a session management network element in the above method embodiment, where the transceiver module 11 is configured to perform operations related to the transceiver of the session management network element in the above method embodiment, and the processing module 12 is configured to perform operations related to the processing of the session management network element in the above method embodiment.

A possible implementation manner, the transceiver module 11 is configured to send user plane path information of a terminal device to an application function network element, where the session management network element is a network element that provides services for a session of the terminal device, the terminal device belongs to a terminal set, and the user plane path information is used to determine an edge application server for the terminal set; and receiving an edge application server switching message from the application function network element, wherein the edge application server switching message comprises information of the edge application server of the terminal set, and the edge application server switching message is used for indicating switching to the edge application server.

Optionally, the processing module 12 is configured to determine that an edge application server of the terminal device is to be reselected.

Optionally, the transceiver module 11 is further configured to receive a user plane path information request message from the application function network element, where the user plane path information request message includes an identifier of the terminal device.

Optionally, the user plane path information includes DNAI.

Optionally, the user plane path information further includes a transmission delay corresponding to the DNAI, where the transmission delay corresponding to the DNAI is less than or equal to a threshold.

Optionally, the transceiver module 11 is further configured to send a message to a data management network element or the application function network element, where the message is used to indicate that the terminal device or the edge application server of the terminal set is to be reselected.

Optionally, the transceiver module 11 is further configured to receive a subscription message from a data management network element, where the subscription message is used to subscribe to a reselection notification of the terminal device or an edge application server of the terminal set.

Optionally, the transceiver module 11 is further configured to send a subscription message to the data management network element, where the subscription message is used to subscribe to a reselection notification of the edge application server of the terminal set.

Optionally, the user plane path information is information of granularity of the terminal set.

In a third design, the apparatus 10 may be a data management network element in the foregoing embodiment, or may be a component (such as a chip) of the data management network element. The apparatus 10 may implement steps or processes performed by the data management network element in the above method embodiment, where the transceiver module 11 is configured to perform operations related to the transceiver of the data management network element in the above method embodiment, and the processing module 12 is configured to perform operations related to the processing of the data management network element in the above method embodiment.

A possible implementation manner, the transceiver module 11 is configured to receive an edge application server reselection indication message from a first session management network element, where the edge application server reselection indication message is used to indicate that an edge application server of the first terminal device or a terminal set is to be reselected, and the first session management network element is a network element that provides services for a session of the first terminal device, and the first terminal device belongs to the terminal set; and sending an edge application server reselection notification message to a second session management network element, wherein the edge application server reselection notification message comprises an identifier of the terminal set, the edge application server reselection notification message is used for indicating that an edge application server of the terminal set is to be reselected, the second session management network element is a network element for providing services for a session of a second terminal device, and the second terminal device is a terminal device except the first terminal device in the terminal set.

Optionally, the transceiver module 11 is further configured to: and sending a subscription message to the first session management network element, wherein the subscription message is used for subscribing to a reselection notification of the first terminal equipment or the edge application server of the terminal set.

Optionally, the transceiver module 11 is further configured to: the data management network element receives a subscription message from the second session management network element, wherein the subscription message is used for subscribing to a reselection notification of an edge application server of the terminal set.

Optionally, the processing module 12 is configured to: and the data management network element determines the second session management network element according to the information of the terminal set.

Optionally, the information of the terminal set includes an identifier of the terminal set and identifiers of all terminal devices in the terminal set.

It should be understood that the specific process of each module performing the corresponding steps is described in detail in the above method embodiments, and for brevity, will not be described in detail herein.

It should also be appreciated that the apparatus 10 herein is embodied in the form of functional modules. The term module herein may refer to an application specific integrated circuit (application specific integrated circuit, ASIC), an electronic circuit, a processor (e.g., a shared, dedicated, or group processor, etc.) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that support the described functionality. In an alternative example, it will be understood by those skilled in the art that the apparatus 10 may be specifically configured as the first session management network element in the foregoing embodiments, and may be configured to perform the respective flows and/or steps corresponding to the first session management network element in the foregoing method embodiments; alternatively, the apparatus 10 may be specifically a second session management network element in the foregoing embodiments, and may be configured to perform each flow and/or step corresponding to the second session management network element in the foregoing method embodiments; alternatively, the apparatus 10 may be specifically an application function network element in the foregoing embodiments, and may be configured to execute each flow and/or step corresponding to the application network element in the foregoing method embodiments; alternatively, the apparatus 10 may be specifically a data management network element in the foregoing embodiments, and may be configured to execute each flow and/or step corresponding to the data management network element in the foregoing method embodiments, so that repetition is avoided, and no further description is given here.

The apparatus 10 of each of the above embodiments has a function of implementing the corresponding steps performed by the network device (such as an application function network element, or a session management network element, or a data management network element) in the above method. The functions may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or software comprises one or more modules corresponding to the functions; for example, the transceiver module may be replaced by a transceiver (e.g., a transmitting unit in the transceiver module may be replaced by a transmitter, a receiving unit in the transceiver module may be replaced by a receiver), and other units, such as a processing module, etc., may be replaced by a processor, to perform the transceiver operations and associated processing operations, respectively, in various method embodiments.

The transceiver module 11 may be a transceiver circuit (for example, may include a receiving circuit and a transmitting circuit), and the processing module may be a processing circuit.

It should be noted that the apparatus in fig. 9 may be a network element or a device in the foregoing embodiment, or may be a chip or a chip system, for example: system on chip (SoC). The transceiver module can be an input/output circuit and a communication interface; the processing module is an integrated processor or microprocessor or integrated circuit on the chip. And are not limited herein.

As shown in fig. 10, another apparatus 20 for selecting an edge application server is provided in an embodiment of the present application. The apparatus 20 comprises a processor 21, the processor 21 being arranged to execute computer programs or instructions stored in a memory 22 or to read data/signalling stored in the memory 22 for performing the methods of the method embodiments above. Optionally, the processor 21 is one or more.

Optionally, as shown in fig. 10, the apparatus 20 further comprises a memory 22, the memory 22 being for storing computer programs or instructions and/or data. The memory 22 may be integrated with the processor 21 or may be provided separately. Optionally, the memory 22 is one or more.

Optionally, as shown in fig. 10, the apparatus 20 further comprises a transceiver 23, the transceiver 23 being used for receiving and/or transmitting signals. For example, the processor 21 is configured to control the transceiver 23 to receive and/or transmit signals.

As an alternative, the apparatus 20 is configured to implement the operations performed by the various network elements or devices in the various method embodiments above.

For example, the processor 21 is configured to execute computer programs or instructions stored in the memory 22 to implement the relevant operations of the application function network elements in the above respective method embodiments. For example, the method performed by the application function network element in the embodiment shown in fig. 3, or the method performed by the AF in any one of the embodiments shown in fig. 5 to 8.

As another example, the processor 21 is configured to execute a computer program or instructions stored in the memory 22 to implement the relevant operations of the session management network element in the above method embodiments. For example, the first session management network element, or the second session management network element, or the method performed by the SMF1, or the SMF2, or the anchor SMF in any of the embodiments shown in fig. 3 to 8.

As another example, the processor 21 is configured to execute computer programs or instructions stored in the memory 22 to implement the relevant operations of the data management network element in the above method embodiments. For example, the method performed by the data management network element in the embodiment shown in fig. 3, or the method performed by the UDR in the embodiment shown in any one of fig. 5 to 8.

It should be appreciated that the processors referred to in the embodiments of the present application may be central processing modules (central processing unit, CPUs), but may also be other general purpose processors, digital signal processors (digital signal processor, DSPs), application specific integrated circuits (application specific integrated circuit, ASICs), off-the-shelf programmable gate arrays (field programmable gate array, FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should also be understood that the memories mentioned in the embodiments of the present application may be volatile memories and/or nonvolatile memories. The nonvolatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. The volatile memory may be random access memory (random access memory, RAM). For example, RAM may be used as an external cache. By way of example, and not limitation, RAM includes the following forms: static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous DRAM (SLDRAM), and direct memory bus RAM (DR RAM).

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

It should also be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

The embodiments of the present application further provide a computer readable storage medium, on which computer instructions for implementing the method performed by the core network element in the method embodiments described above are stored.

For example, the computer program when executed by a computer, enables the computer to implement the method performed by the application function network element in the embodiments of the method described above.

As another example, the computer program when executed by a computer may enable the computer to implement the method performed by the first session management network element in the embodiments of the method described above.

As another example, the computer program when executed by a computer may enable the computer to implement the method performed by the second session management network element in the embodiments of the method described above.

As another example, the computer program when executed by a computer may enable the computer to implement the method performed by the session management network element in the embodiments of the method described above.

As another example, the computer program when executed by a computer may enable the computer to implement the method performed by the data management network element in the embodiments of the method described above.

The embodiments of the present application also provide a computer program product, which contains instructions that, when executed by a computer, implement the method performed by the core network element in the above method embodiments.

The embodiment of the application also provides a communication system, which comprises one or more of the application function network element, the session management network element (comprising the session management network element, the first session management network element and the second session management network element) and the data management network element.

The explanation and beneficial effects of the related content in any of the above-mentioned devices can refer to the corresponding method embodiments provided above, and are not repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Furthermore, the coupling or direct coupling or communication connection shown or discussed with each other may be through some interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. For example, the computer may be a personal computer, a server, or a network device, etc. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, optical fiber, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. For example, the aforementioned usable media include, but are not limited to, U disk, removable hard disk, read-only memory (ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other various media that can store program code.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of selecting an edge application server, comprising:

the method comprises the steps that an application function network element receives a message from a first session management network element, wherein the message is used for indicating an edge application server of first terminal equipment to be reselected, the first session management network element is a network element for providing services for a session of the first terminal equipment, and the first terminal equipment belongs to a terminal set;

the application function network element obtains first user plane path information of the first terminal equipment and second user plane path information of second terminal equipment, wherein the second terminal equipment is terminal equipment except the first terminal equipment in the terminal set;

and the application function network element selects a first edge application server for the terminal set according to the first user plane path information and the second user plane path information.

2. The method of claim 1, wherein the first user plane path information comprises a first data network access identity DNAI, wherein the second user plane path information comprises a second DNAI, and wherein the first DNAI and the second DNAI each comprise a DNAI corresponding to the first edge application server.

3. The method of claim 2, wherein the first user plane path information further comprises a transmission delay corresponding to the first DNAI, wherein the second user plane path information further comprises a transmission delay corresponding to the second DNAI, and wherein the transmission delay corresponding to the DNAI corresponding to the first edge application server is less than or equal to a threshold.

4. A method according to any one of claims 1 to 3, further comprising:

the application function network element sends an edge application server switching message to the first session management network element and the second session management network element, wherein the edge application server switching message comprises information of the first edge application server, and the edge application server switching message is used for indicating switching to the first edge application server.

5. The method according to any of claims 1 to 4, wherein the application function network element obtaining second user plane path information of a second terminal device comprises:

The application function network element sends a user plane path information request message to a second session management network element according to the information of the terminal set, wherein the user plane path information request message comprises an identifier of the second terminal device, and the second session management network element is a network element for providing service for the session of the second terminal device;

the application function network element receives the second user plane path information from the second session management network element.

6. The method of claim 5, wherein the method further comprises:

the application function network element determines DNAI to be selected according to the first user plane path information, and the user plane path information request message further comprises the DNAI to be selected.

7. A method of selecting an edge application server, comprising:

the method comprises the steps that a session management network element sends user plane path information of terminal equipment to an application function network element, wherein the session management network element is a network element for providing services for a session of the terminal equipment, the terminal equipment belongs to a terminal set, and the user plane path information is used for determining an edge application server for the terminal set;

the session management network element receives an edge application server switching message from the application function network element, wherein the edge application server switching message comprises information of the edge application server of the terminal set, and the edge application server switching message is used for indicating switching to the edge application server.

8. The method of claim 7, wherein the method further comprises:

and the session management network element determines that an edge application server of the terminal equipment is to be reselected.

9. The method of claim 7, wherein the method further comprises:

the session management network element receives a user plane path information request message from the application function network element, wherein the user plane path information request message comprises the identification of the terminal equipment.

10. The method according to any of claims 7 to 9, wherein the user plane path information comprises DNAI.

11. The method of claim 4, wherein the user plane path information further comprises a transmission delay associated with the DNAI, the transmission delay associated with the DNAI being less than or equal to a threshold.

12. The method according to any one of claims 7 to 11, further comprising:

and the session management network element sends a message to a data management network element or the application function network element, wherein the message is used for indicating the terminal equipment or the edge application server of the terminal set to be reselected.

13. The method according to any one of claims 7 to 12, further comprising:

The session management network element receives a subscription message from a data management network element, wherein the subscription message is used for subscribing to a reselection notification of the terminal equipment or an edge application server of the terminal set.

14. The method according to any one of claims 7 to 13, further comprising:

and the session management network element sends a subscription message to the data management network element, wherein the subscription message is used for subscribing the reselection notification of the edge application server of the terminal set.

15. A method of selecting an edge application server, comprising:

the data management network element receives an edge application server reselection indication message from a first session management network element, wherein the edge application server reselection indication message is used for indicating an edge application server of the first terminal equipment or a terminal set to be reselected, the first session management network element is a network element for providing services for a session of the first terminal equipment, and the first terminal equipment belongs to the terminal set;

the data management network element sends an edge application server reselection notification message to a second session management network element, wherein the edge application server reselection notification message comprises an identifier of the terminal set, the edge application server reselection notification message is used for indicating that an edge application server of the terminal set is to be reselected, the second session management network element is a network element for providing services for a session of a second terminal device, and the second terminal device is a terminal device except the first terminal device in the terminal set.

16. The method of claim 15, wherein prior to the receiving the message from the first session management network element, the method further comprises:

the data management network element sends a subscription message to the first session management network element, wherein the subscription message is used for subscribing to a reselection notification of the first terminal device or the edge application server of the terminal set.

17. The method according to claim 15 or 16, wherein prior to sending the edge application server reselection notification message, the method further comprises:

the data management network element receives a subscription message from the second session management network element, wherein the subscription message is used for subscribing to a reselection notification of an edge application server of the terminal set.

18. The method according to any of claims 15 to 17, wherein the sending of the edge application server reselection notification message by the data management network element to the second session management network element comprises:

and the data management network element sends an edge application server reselection notification message to a second session management network element according to the information of the terminal set.

19. The method of claim 18, wherein the information for the set of terminals includes an identification of the set of terminals and an identification of all terminal devices in the set of terminals.

20. A method of selecting an edge application server, comprising:

an application function network element receives a message from a session management network element, wherein the message is used for indicating an edge application server of a terminal set to be reselected, and the session management network element is a network element for providing service for a session of terminal equipment in the terminal set;

and the application function network element selects a first edge application server for the terminal set according to the user plane path information of the terminal equipment in the terminal set.

21. The method of claim 20, wherein the message comprises: user plane path information of terminal equipment in the terminal set.

22. The method of claim 20, wherein the method further comprises: the application function network element obtains the user plane path information of the terminal equipment in the terminal set from the session management network element.

23. The method of any of claims 20 to 22, wherein the user plane path information comprises DNAI, the DNAI comprising DNAI of the first edge application server.

24. The method of claim 23, wherein the user plane path information further comprises a transmission delay corresponding to the DNAI, and wherein the transmission delay corresponding to the DNAI corresponding to the first edge application server is less than or equal to a threshold.

25. The method according to any of the claims 20 to 24, characterized in that before the application function network element receives the message from the session management network element, the method further comprises:

the application function network element receives an edge application service acquisition request message from terminal equipment in the terminal set, wherein the terminal equipment belongs to the terminal set;

the application function network element sends a session management network element reselection request message to a first session management network element of the terminal equipment according to the information of the terminal set, wherein the session management network element reselection request message comprises an identifier of the terminal set and an identifier of terminal equipment in the terminal set, and the session management network element reselection request message is used for requesting the terminal equipment to be reselected to the session management network element.

26. The method according to any one of claims 20 to 25, further comprising:

the application function network element sends the identifier of the terminal set and the identifier of the terminal equipment in the terminal set to the session management network element.

27. An apparatus for selecting an edge application server, the apparatus comprising: a module for performing the method of any one of claims 1 to 6, or for performing the method of any one of claims 7 to 14, or for performing the method of any one of claims 15 to 19, or for performing the method of any one of claims 20 to 26.

28. An apparatus for selecting an edge application server, comprising:

a processor for executing a computer program stored in a memory to cause the apparatus to perform the method of any one of claims 1 to 6 or to cause the apparatus to perform the method of any one of claims 7 to 14 or to cause the apparatus to perform the method of any one of claims 15 to 19 or to cause the apparatus to perform the method of any one of claims 20 to 26.

29. A computer program product comprising instructions for performing the method of any one of claims 1 to 6 or for performing the method of any one of claims 7 to 14 or for performing the method of any one of claims 15 to 19 or for performing the method of any one of claims 20 to 26.