CN112073997A

CN112073997A - Communication method and device

Info

Publication number: CN112073997A
Application number: CN201910500931.0A
Authority: CN
Inventors: 宗在峰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-06-11
Filing date: 2019-06-11
Publication date: 2020-12-11
Anticipated expiration: 2039-06-11
Also published as: WO2020249032A1; CN112073997B

Abstract

The application provides a communication method and device. The scheme comprises the following steps: the session management network element obtains the first control information and the second control information. Then, the session management network element determines that a first interface exists between the first candidate mid-user plane network element and the first candidate anchor user plane network element according to the first control information and the second control information, and selects the first candidate mid-user plane network element and the first candidate anchor user plane network element as target user plane network elements. The first control information includes first interface information of at least one candidate mid-user plane network element, the second control information includes first interface information of at least one candidate anchor user plane network element, the first candidate mid-user plane network element is a user plane network element of the at least one candidate mid-user plane network element, and the first candidate anchor user plane network element is a user plane network element of the at least one candidate anchor user plane network element. The method is suitable for the selection process of the user plane network element or the session management network element.

Description

Communication method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method and apparatus.

Background

In an existing fifth generation (5rd generation, 5G) mobile communication system, a Session Management Function (SMF) network element does not consider whether an N9 interface exists between selected UPF network elements in a process of selecting a User Plane Function (UPF) network element, or an access and mobility management function (AMF) network element does not consider whether an N9 interface exists between UPF network elements controlled by the selected SMF network element in a process of selecting an SMF network element, thereby causing a session connection establishment failure between a Radio Access Network (RAN) to which a terminal device accesses and a data network (data, DN) to which the terminal device has to access.

Disclosure of Invention

The embodiment of the application provides a communication method and a communication device, which can improve the reliability and efficiency of network element selection.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, a method of communication is provided. The communication method comprises the following steps: the session management network element obtains the first control information and the second control information. Wherein the first control information comprises first interface information of at least one candidate mid-user plane network element, and the second control information comprises first interface information of at least one candidate anchor user plane network element. Then, the session management network element determines that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element according to the first control information and the second control information. The first candidate intermediate user plane network element is a user plane network element in the at least one candidate intermediate user plane network element, and the first candidate anchor user plane network element is a user plane network element in the at least one candidate anchor user plane network element. And then, the session management network element selects the first candidate intermediate user plane network element and the first candidate anchor user plane network element as target user plane network elements.

In the communication method provided by the application, the session management network element firstly determines that a first interface exists between a first candidate mid-user plane network element in the at least one candidate mid-user plane network element and a first candidate anchor-user plane network element in the at least one candidate anchor-user plane network element according to the first interface information of the at least one candidate mid-user plane network element and the first interface information of the at least one candidate anchor-user plane network element, and then selects the first candidate mid-user plane network element and the first candidate anchor-user plane network element as the target user plane network element, so that the situation that normal session connection cannot be established due to the fact that the first interface does not exist between two or more than two user plane network elements selected by the session management network element can be avoided, and the waste of signaling, resource waste and time signaling caused by selecting a proper target user plane network element through multiple interactions can be reduced, the reliability and efficiency of selecting the user plane network element by the session management network element can be improved.

In one possible design approach, the first control information includes: a set of internet protocol addresses of user plane network elements reachable by the first interface of the at least one candidate intermediate user plane network element; the second control information includes: an internet protocol address of a first interface of at least one candidate anchor user plane network element. Correspondingly, the determining, by the session management network element according to the first control information and the second control information, that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element may include: the session management network element determines that the internet protocol address of the first interface of the first candidate anchor user plane network element exists in the internet protocol address set of the user plane network element which the first interface of the first candidate intermediate user plane network element can reach.

In another possible design approach, the first control information includes: an internet protocol address of a first interface of at least one candidate intermediate user plane network element; the second control information includes: a set of internet protocol addresses of user plane network elements reachable by the first interface of the at least one candidate anchor user plane network element. Correspondingly, the determining, by the session management network element according to the first control information and the second control information, that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element may include: the session management network element determines that the internet protocol address of the first interface of the first candidate intermediate user plane network element exists in the internet protocol address set of the user plane network element which can be reached by the first interface of the first candidate anchor user plane network element.

In one possible design approach, the first control information may include: an identification set of data centers reachable by a first interface of at least one candidate intermediate user plane network element; the second control information may include: an identification of a data center in which the at least one candidate anchor user plane network element is located. Correspondingly, the determining, by the session management network element according to the first control information and the second control information, that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element may include: the session management network element determines that the identifier of the data center where the first candidate anchor user plane network element is located exists in the identifier set of the data center where the first interface of the first candidate intermediate user plane network element is reachable.

In another possible design approach, the first control information may include: an identifier of a data center in which the at least one candidate mid-user plane network element is located; the second control information may include: and the identification set of the data center of which the first interface of the at least one candidate anchor user plane network element is reachable. Correspondingly, the determining, by the session management network element according to the first control information and the second control information, that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element may include: the session management network element determines that the identifier of the data center where the first candidate intermediate user plane network element is located exists in the identifier set of the data center where the first interface of the first candidate anchor user plane network element is reachable.

In one possible design approach, the first control information may include: an identification set of user plane network elements reachable by the first interface of the at least one candidate intermediate user plane network element; the second control information may include: an identification of at least one candidate anchor user plane network element. Correspondingly, the determining, by the session management network element according to the first control information and the second control information, that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element may include: the session management network element determines that the identifier of the first candidate anchor user plane network element exists in the identifier set of the user plane network element which is reachable by the first interface of the first candidate intermediate user plane network element.

In another possible design approach, the first control information may include: an identification of at least one candidate intermediate user plane network element; the second control information may include: and the identification set of the user plane network elements which can be reached by the first interface of the at least one candidate anchor user plane network element. Correspondingly, the determining, by the session management network element according to the first control information and the second control information, that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element may include:

the session management network element determines that the identifier of the first candidate intermediate user plane network element exists in the identifier set of the user plane network element which is reachable by the first interface of the first candidate anchor user plane network element.

In one possible design approach, the first control information may include: a set of locations of user plane network elements reachable by the first interface of the at least one candidate intermediate user plane network element; the second control information may include: a location of at least one candidate anchor user plane network element. Correspondingly, the determining, by the session management network element according to the first control information and the second control information, that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element may include: the session management network element determines that the position of the candidate first anchor user plane network element exists in the position set of the user plane network element which is reachable by the first interface of the first candidate middle user plane network element.

In another possible design approach, the first control information may include: a location of at least one candidate intermediate user plane network element; the second control information may include: a set of locations of user plane network elements reachable by the first interface of the at least one candidate anchor user plane network element. Correspondingly, the determining, by the session management network element according to the first control information and the second control information, that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element may include: the session management network element determines that the position of the first candidate intermediate user plane network element exists in the position set of the user plane network element which is reachable by the first interface of the first candidate anchor user plane network element.

In a possible design method, the obtaining, by the session management network element, the first control information and the second control information may include: the session management network element acquires first control information from at least one candidate intermediate user plane network element or network storage network element; and the session management network element acquires the second control information from at least one candidate anchor point user plane network element or network storage network element.

Illustratively, the at least one candidate intermediate user plane element may be: a user plane network element with a second interface exists between the user plane network element and an access network element accessed by the terminal equipment; the at least one candidate anchor user plane mesh may be: and the user plane network element has a third interface with the data network to be accessed by the terminal equipment.

In a second aspect, a method of communication. The communication method comprises the following steps: and the access management network element acquires the third control information and the fourth control information. Wherein the third control information comprises first interface information of a user plane network element controlled by at least one candidate intermediate session management network element, and the fourth control information comprises first interface information of a user plane network element controlled by at least one candidate anchor session management network element. Then, the access management network element determines, according to the third control information and the fourth control information, that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element. The first candidate intermediate session management network element is a session management network element in the at least one candidate intermediate session management network element, and the first candidate anchor session management network element is a session management network element in the at least one candidate anchor session management network element. And then, the access management network element selects the first candidate intermediate session management network element and the first candidate anchor point session management network element as a target session management network element.

In the communication method provided by the present application, the access management network element first determines, according to the first interface information of the user plane network element controlled by the first candidate middle session management network element in the at least one candidate middle session management network element and the first interface information of the user plane network element controlled by the first candidate anchor session management network element in the at least one candidate anchor session management network element, that a first interface exists between the user plane network element controlled by the first candidate middle session management network element and the user plane network element controlled by the first candidate middle session management network element, and then selects the first candidate middle session management network element and the first candidate anchor session management network element as the target session management network element, which can avoid the situation that a normal session connection cannot be established due to the absence of the first interface between the user plane network elements controlled by two or more session management network elements selected by the access management network element, and signaling waste, resource waste and time waste caused by that the appropriate target session management network element can be selected only through multiple interactions can be reduced, and the reliability and the efficiency of selecting the session management network element by the access management network element can be improved.

In one possible design approach, the third control information may include: a set of internet protocol addresses of user plane network elements reachable by a first interface of the user plane network element controlled by the at least one candidate mid-session management network element; the fourth control information may include: an internet protocol address of a first interface of a user plane network element controlled by the at least one candidate anchor session management network element. Correspondingly, the determining, by the access management network element, that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information may include: the access management network element determines that the internet protocol address of the first interface of the user plane network element controlled by the first candidate anchor session management network element exists in the internet protocol address set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the first candidate intermediate session management network element.

In another possible design approach, the third control information may include: an internet protocol address of a first interface of a user plane network element controlled by at least one candidate mid-session management network element; the fourth control information may include: and the internet protocol address set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element. Correspondingly, the determining, by the access management network element, that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information may include: the access management network element determines that the internet protocol address of the first interface of the user plane network element controlled by the first candidate intermediate session management network element exists in the internet protocol address set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the first candidate anchor session management network element.

In one possible design approach, the third control information may include: the identification set of the data center which is reachable by the first interface of the user plane network element controlled by the at least one candidate middle conversation management network element; the fourth control information may include: and the identifier of the data center where the user plane network element controlled by the at least one candidate anchor point session management network element is located. Correspondingly, the determining, by the access management network element, that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information may include: the access management network element determines that the identifier of the data center where the user plane network element controlled by the first candidate anchor session management network element is located exists in the identifier set of the data center where the first interface of the user plane network element controlled by the first candidate intermediate session management network element is reachable.

In another possible design approach, the third control information may include: an identifier of a data center where a user plane network element controlled by at least one candidate middle session management network element is located; the fourth control information may include: and the identifier set of the data center which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element. Correspondingly, the determining, by the access management network element, that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information may include: the access management network element determines that the identifier of the data center where the user plane network element controlled by the first candidate intermediate session management network element is located exists in the identifier set of the data center where the first interface of the user plane network element controlled by the first candidate anchor session management network element is reachable.

In one possible design approach, the third control information may include: at least one candidate mid-session management network element controlled user plane network element, wherein the candidate mid-session management network element is a first interface reachable user plane network element; the fourth control information may include: an identification of a user plane network element controlled by the at least one candidate anchor session management network element. Correspondingly, the determining, by the access management network element, that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information may include: the access management network element determines that the identifier of the user plane network element controlled by the first candidate anchor session management network element exists in the identifier set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate intermediate session management network element.

In another possible design approach, the third control information may include: an identity of a user plane network element controlled by at least one candidate mid-session management network element; the fourth control information may include: and the identifier set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element. Correspondingly, the determining, by the access management network element, that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information may include: the access management network element determines that the identifier of the user plane network element controlled by the first candidate intermediate session management network element exists in the identifier set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the first candidate anchor session management network element.

In one possible design approach, the third control information may include: a set of locations of user plane network elements reachable by a first interface of a user plane network element controlled by at least one candidate mid-session management network element; the fourth control information may include: the location of the user plane network element controlled by the at least one candidate anchor session management network element. Correspondingly, the determining, by the access management network element, that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information may include: the access management network element determines that the position of the user plane network element controlled by the first candidate anchor session management network element exists in the position set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate intermediate session management network element.

In another possible design approach, the third control information may include: a location of a user plane network element controlled by at least one candidate mid-session management network element; the fourth control information may include: and the position set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element. Correspondingly, the determining, by the access management network element, that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information may include: the access management network element determines that the position of the user plane network element controlled by the first candidate intermediate session management network element exists in the position set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate anchor session management network element.

In a possible design method, the obtaining, by the access management network element, the third control information and the fourth control information may include: the access management network element acquires third control information from the network storage network element or at least one candidate intermediate session management network element; and the access management network element acquires the fourth control information from the network storage network element or the at least one candidate anchor point session management network element.

Illustratively, the at least one candidate intermediate session management network element may be: a session management network element of the user plane network element with a second interface exists between the controlled user plane network element and an access network element accessed by the terminal equipment; the at least one candidate anchor session management network element may be: and a session management network element of the user plane network element with a third interface between the controlled user plane network element and the data network to be accessed by the terminal equipment exists in the controlled user plane network element.

In a third aspect, a method of communication is provided. The communication method comprises the following steps: the network storage network element receives and stores the first interface information of at least one user plane network element. The first interface information includes an identifier of a user plane network element that is reachable by the user plane network element in the at least one user plane network element. The network storage network element then receives the first request. The first request is used for acquiring first interface information of a candidate user plane network element in at least one user plane network element, or the first request is used for requesting to select the candidate user plane network element from the at least one user plane network element, or the first request is used for requesting to select the candidate session management network element according to the first interface information of the at least one user plane network element. Thereafter, the network storage network element sends a first response. The first response carries first interface information of a candidate user plane network element in at least one user plane network element, or an identifier of the candidate user plane network element, or an identifier of a candidate session management network element.

In the communication method provided by the present application, the network storage element may receive and uniformly manage the first interface information of at least one user plane network element, and when the network storage element receives the first request for selecting a user plane network element sent by the session management element, the network storage element may send a first response carrying the first interface information of the candidate user plane network element or the identifier of the candidate user plane network element to the session management element, so that the session management element quickly selects the target user plane network element, or when the network storage element receives the first request for selecting a session management element sent by the access management element, the network storage element may send a first response carrying the first interface information of the user plane network element controlled by the candidate session management element or the identifier of the user plane network element controlled by the candidate session management element to the access management element, therefore, the access management network element can quickly select the target session management network element, the situation that normal session connection cannot be established due to the fact that a first interface does not exist between two or more user plane network elements in a xu state of the session management network element and/or a first interface does not exist between the user plane network elements controlled by the two or more session management network elements selected by the access management network element can be avoided, signaling waste, resource waste and time waste caused by the fact that the appropriate target user plane network element and/or the target session management network element can be selected through multiple interactions can be reduced, and the reliability and the efficiency of the session management network element selected by the session management network element and/or the session management network element selected by the access management network element can be improved.

In a possible design method, the receiving and storing, by the network storage element, the first interface information of at least one user plane network element may include at least one of: a network storage network element receives and stores first interface information sent by at least one user plane network element; the network storage network element receives and stores first interface information of at least one user plane network element sent by the operation management maintenance equipment; and the network storage network element receives and stores the first interface information of the user plane network element controlled by the at least one session management network element, which is sent by the at least one session management network element.

Illustratively, the candidate user plane network elements may comprise candidate intermediate user plane network elements. In one possible design method, the first request carries network information of an access network element to which the terminal device is accessed. Correspondingly, the first response carries the first interface information of the candidate middle user plane network element. And a second interface exists between the candidate middle user plane network element and the access network element.

Illustratively, the candidate user plane network elements comprise candidate anchor user plane function anchor user plane network elements. In another possible design method, the first request carries network information of a data network to be accessed by the terminal device. Correspondingly, the first response carries the first interface information of the candidate anchor user plane network element. And a third interface exists between the candidate anchor point user plane network element and the data network.

The candidate user plane network elements may include a candidate intermediate user plane function intermediate user plane network element and a candidate anchor user plane function anchor user plane network element, where the candidate intermediate user plane network element is a user plane network element having a second interface with an access network element accessed by the terminal device. In a possible design method, the first request carries first interface information of candidate mid-user plane network elements, and the first interface information of the candidate mid-user plane network elements is used to select, from at least one user plane network element, a user plane network element having a first interface with the candidate mid-user plane network element as a candidate anchor user plane network element. Correspondingly, the first response carries the identifier of the candidate anchor user plane network element.

The candidate user plane network elements may include a candidate intermediate user plane function intermediate user plane network element and a candidate anchor user plane function anchor user plane network element, where the candidate anchor user plane network element is a user plane network element having a third interface with a data network to be accessed by the terminal device. In another possible design method, the first request carries first interface information of a candidate anchor user plane network element, and the first interface information of the candidate anchor user plane network element is used for selecting, from at least one user plane network element, a user plane network element having a first interface with the candidate anchor user plane network element as a candidate intermediate user plane network element. Correspondingly, the first response carries the identifier of the candidate middle user plane network element.

The candidate user plane network elements may illustratively include candidate mid-user plane function mid-user plane network elements and candidate anchor user plane function anchor user plane network elements. In yet another possible design method, the first request carries network information of an access network element to which the terminal device is accessed and network information of a data network to which the terminal device is to access. Correspondingly, the first response carries the first interface information of the candidate middle user plane network element and the first interface information of the candidate anchor user plane network element. The candidate intermediate user plane network element is a user plane network element with a second interface between the candidate intermediate user plane network element and an access network element accessed by the terminal equipment, and the candidate anchor point user plane network element is a user plane network element with a third interface between the candidate anchor point user plane network element and a data network accessed by the terminal equipment.

Optionally, a first interface exists between the candidate intermediate user plane network element and the candidate anchor user plane network element.

Illustratively, the candidate session management network element may comprise a candidate mid-session management network element. In one possible design method, the first request carries network information of an access network element to which the terminal device is accessed. Correspondingly, the first response carries the first interface information of the user plane network element controlled by the candidate middle session management network element. And a second interface exists between the user plane network element controlled by the candidate intermediate session management network element and the access network element.

Illustratively, the candidate session management network element may comprise a candidate anchor session management function anchor session management network element. In another possible design method, the first request carries network information of a data network to be accessed by the terminal device. Correspondingly, the first response carries the first interface information of the user plane network element controlled by the candidate anchor session management network element. And a third interface exists between the user plane network element controlled by the candidate anchor point session management network element and the data network to be accessed by the terminal equipment.

The candidate session management network elements may include candidate intermediate session management network elements and candidate anchor session management function anchor session management network elements, and among the user plane network elements controlled by the candidate intermediate session management network elements, there is a user plane network element having a second interface with an access network element accessed by the terminal device. In a possible design method, the first request carries first interface information of a user plane network element controlled by a candidate middle session management network element, and the first interface information of the user plane network element controlled by the candidate middle session management network element is used for selecting a first user plane network element having a first interface with the user plane network element controlled by the candidate middle session management network element from at least one user plane network element, and selecting a candidate anchor point session management network element from the session management network elements controlling the first user plane network element. Correspondingly, the first response carries the identifier of the candidate anchor session management network element.

The candidate session management network elements may include a candidate intermediate user plane function intermediate session management network element and a candidate anchor session management function anchor session management network element, where a user plane network element having a third interface with a data network to be accessed by the terminal device exists in the user plane network elements controlled by the candidate anchor session management network element. In another possible design method, the first request carries first interface information of a user plane network element controlled by a candidate anchor session management network element, and the first interface information of the user plane network element controlled by the candidate anchor session management network element is used for selecting a second user plane network element having a first interface with the user plane network element controlled by the candidate anchor session management network element from at least one user plane network element, and selecting a candidate intermediate session management network element from session management network elements controlling the second user plane network element. Correspondingly, the first response carries the first interface information of the user plane network element controlled by the candidate middle session management network element.

Illustratively, the candidate session management network elements may include a candidate mid-user plane function mid-session management network element and a candidate anchor user plane function anchor session management network element. In yet another possible design method, the first request carries network information of an access network element to which the terminal device is accessed and network information of a data network to which the terminal device is to access. Correspondingly, the first response carries the first interface information of the user plane network element controlled by the candidate intermediate session management network element and the first interface information of the user plane network element controlled by the candidate anchor session management network element. And the user plane network element controlled by the candidate anchor point session management network element has a user plane network element with a third interface with a data network to be accessed by the terminal equipment.

Optionally, a first interface exists between the user plane network element controlled by the candidate intermediate session management network element and the user plane network element controlled by the candidate anchor session management network element.

In a fourth aspect, a communication device is provided. The communication device includes: a processing module and a transceiver module. The transceiver module is used for acquiring the first control information and the second control information. Wherein the first control information comprises first interface information of at least one candidate mid-user plane network element, and the second control information comprises first interface information of at least one candidate anchor user plane network element. And the processing module is used for determining that a first interface exists between the first candidate intermediate user plane network element and the first candidate anchor user plane network element according to the first control information and the second control information. The first candidate intermediate user plane network element is a user plane network element in the at least one candidate intermediate user plane network element, and the first candidate anchor user plane network element is a user plane network element in the at least one candidate anchor user plane network element. The processing module is further configured to select the first candidate mid-user plane network element and the first candidate anchor user plane network element as target user plane network elements.

In one possible design, the first control information includes: a set of internet protocol addresses of user plane network elements reachable by the first interface of the at least one candidate intermediate user plane network element; the second control information includes: an internet protocol address of a first interface of at least one candidate anchor user plane network element. Correspondingly, the processing module is further configured to determine that the internet protocol address of the first interface of the first candidate anchor user plane network element exists in the internet protocol address set of the user plane network element reachable by the first interface of the first candidate intermediate user plane network element.

In another possible design, the first control information includes: an internet protocol address of a first interface of at least one candidate intermediate user plane network element; the second control information includes: a set of internet protocol addresses of user plane network elements reachable by the first interface of the at least one candidate anchor user plane network element. Correspondingly, the processing module is further configured to determine that the internet protocol address of the first interface of the first candidate intermediate user plane network element exists in the internet protocol address set of the user plane network element reachable by the first interface of the first candidate anchor user plane network element.

In one possible design, the first control information may include: an identification set of data centers reachable by a first interface of at least one candidate intermediate user plane network element; the second control information may include: an identification of a data center in which the at least one candidate anchor user plane network element is located. Correspondingly, the processing module is further configured to determine that an identifier of the data center where the first candidate anchor user plane network element is located exists in the identifier set of the data center where the first interface of the first candidate intermediate user plane network element is reachable.

In another possible design, the first control information may include: an identifier of a data center in which the at least one candidate mid-user plane network element is located; the second control information may include: and the identification set of the data center of which the first interface of the at least one candidate anchor user plane network element is reachable. Correspondingly, the processing module is further configured to determine that an identifier of a data center where the first candidate intermediate user plane network element is located exists in the identifier set of data centers where the first interface of the first candidate anchor user plane network element is reachable.

In one possible design, the first control information may include: an identification set of user plane network elements reachable by the first interface of the at least one candidate intermediate user plane network element; the second control information may include: an identification of at least one candidate anchor user plane network element. Correspondingly, the processing module is further configured to determine that the identifier of the first candidate anchor user plane network element exists in the identifier set of the user plane network element reachable by the first interface of the first candidate intermediate user plane network element.

In another possible design, the first control information may include: an identification of at least one candidate intermediate user plane network element; the second control information may include: and the identification set of the user plane network elements which can be reached by the first interface of the at least one candidate anchor user plane network element. Correspondingly, the processing module is further configured to determine that the identifier of the first candidate intermediate user plane network element exists in the identifier set of the user plane network element reachable by the first interface of the first candidate anchor user plane network element.

In one possible design, the first control information may include: a set of locations of user plane network elements reachable by the first interface of the at least one candidate intermediate user plane network element; the second control information may include: a location of at least one candidate anchor user plane network element. Correspondingly, the processing module is further configured to determine that the position of the candidate first anchor user plane network element exists in the position set of the user plane network element reachable by the first interface of the first candidate intermediate user plane network element.

In another possible design, the first control information may include: a location of at least one candidate intermediate user plane network element; the second control information may include: a set of locations of user plane network elements reachable by the first interface of the at least one candidate anchor user plane network element. Correspondingly, the processing module is further configured to determine that a location of the first candidate intermediate user plane network element exists in the location set of the user plane network element reachable by the first interface of the first candidate anchor user plane network element.

In one possible design, the transceiver module is further configured to obtain the first control information from at least one candidate intermediate user plane network element or network storage network element, and obtain the second control information from at least one candidate anchor user plane network element or network storage network element.

In a fifth aspect, a communications apparatus is provided. The communication device includes: a processing module and a transceiver module. The transceiver module is configured to acquire the third control information and the fourth control information. Wherein the third control information comprises first interface information of a user plane network element controlled by at least one candidate intermediate session management network element, and the fourth control information comprises first interface information of a user plane network element controlled by at least one candidate anchor session management network element. And the processing module is used for determining that a first interface exists between the user plane network element controlled by the first candidate intermediate session management network element and the user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information. The first candidate intermediate session management network element is a session management network element in the at least one candidate intermediate session management network element, and the first candidate anchor session management network element is a session management network element in the at least one candidate anchor session management network element. The processing module is further configured to select the first candidate intermediate session management network element and the first candidate anchor point session management network element as a target session management network element.

In one possible design, the third control information may include: a set of internet protocol addresses of user plane network elements reachable by a first interface of the user plane network element controlled by the at least one candidate mid-session management network element; the fourth control information may include: an internet protocol address of a first interface of a user plane network element controlled by the at least one candidate anchor session management network element. Correspondingly, the processing module is further configured to determine that the internet protocol address of the first interface of the user plane network element controlled by the first candidate anchor session management network element exists in the internet protocol address set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate intermediate session management network element.

In another possible design, the third control information may include: an internet protocol address of a first interface of a user plane network element controlled by at least one candidate mid-session management network element; the fourth control information may include: and the internet protocol address set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element. Correspondingly, the processing module is further configured to determine that the internet protocol address of the first interface of the user plane network element controlled by the first candidate intermediate session management network element exists in the internet protocol address set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate anchor session management network element.

In one possible design, the third control information may include: the identification set of the data center which is reachable by the first interface of the user plane network element controlled by the at least one candidate middle conversation management network element; the fourth control information may include: and the identifier of the data center where the user plane network element controlled by the at least one candidate anchor point session management network element is located. Correspondingly, the processing module is further configured to determine that the identifier of the data center where the user plane network element controlled by the first candidate anchor session management network element is located exists in the identifier set of the data center where the first interface of the user plane network element controlled by the first candidate intermediate session management network element is reachable.

In another possible design, the third control information may include: an identifier of a data center where a user plane network element controlled by at least one candidate middle session management network element is located; the fourth control information may include: and the identifier set of the data center which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element. Correspondingly, the processing module is further configured to determine that the identifier of the data center where the user plane network element controlled by the first candidate intermediate session management network element is located exists in the identifier set of the data center where the first interface of the user plane network element controlled by the first candidate anchor session management network element is reachable.

In one possible design, the third control information may include: at least one candidate mid-session management network element controlled user plane network element, wherein the candidate mid-session management network element is a first interface reachable user plane network element; the fourth control information may include: an identification of a user plane network element controlled by the at least one candidate anchor session management network element. Correspondingly, the processing module is further configured to determine that the identifier of the user plane network element controlled by the first candidate anchor session management network element exists in the identifier set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate intermediate session management network element.

In another possible design, the third control information may include: an identity of a user plane network element controlled by at least one candidate mid-session management network element; the fourth control information may include: and the identifier set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element. Correspondingly, the processing module is further configured to determine that the identifier of the user plane network element controlled by the first candidate intermediate session management network element exists in the identifier set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate anchor session management network element.

In one possible design, the third control information may include: a set of locations of user plane network elements reachable by a first interface of a user plane network element controlled by at least one candidate mid-session management network element; the fourth control information may include: the location of the user plane network element controlled by the at least one candidate anchor session management network element. Correspondingly, the processing module is further configured to determine that the location of the user plane network element controlled by the first candidate anchor session management network element exists in the location set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate intermediate session management network element.

In another possible design, the third control information may include: a location of a user plane network element controlled by at least one candidate mid-session management network element; the fourth control information may include: and the position set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element. Correspondingly, the processing module is further configured to determine that the location of the user plane network element controlled by the first candidate intermediate session management network element exists in the location set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate anchor session management network element.

In one possible design, the transceiver module is further configured to obtain third control information from the network storage network element or the at least one candidate intermediate session management network element, and obtain fourth control information from the network storage network element or the at least one candidate anchor session management network element.

In a sixth aspect, a communications apparatus is provided. The communication device includes: a processing module and a transceiver module. The transceiver module is configured to receive first interface information of at least one user plane network element. The first interface information includes an identifier of a user plane network element that is reachable by the user plane network element in the at least one user plane network element. And the processing module is used for storing the first interface information received by the transceiver module. The transceiver module is further configured to receive the first request. The first request is used for acquiring first interface information of a candidate user plane network element in at least one user plane network element, or the first request is used for requesting to select the candidate user plane network element from the at least one user plane network element, or the first request is used for requesting to select the candidate session management network element according to the first interface information of the at least one user plane network element. The transceiver module is further configured to transmit a first response. The first response carries first interface information of a candidate user plane network element in at least one user plane network element, or an identifier of the candidate user plane network element, or an identifier of a candidate session management network element.

In a possible design, the transceiver module is further configured to receive first interface information sent by at least one user plane network element. The transceiver module is further configured to receive first interface information of at least one user plane network element sent by the operation management maintenance device. The transceiver module is further configured to receive first interface information of the user plane network element controlled by the at least one session management network element, where the first interface information is sent by the at least one session management network element.

Illustratively, the candidate user plane network elements may comprise candidate intermediate user plane network elements. In one possible design, the first request carries network information of an access network element to which the terminal device is accessed. Correspondingly, the first response carries the first interface information of the candidate middle user plane network element. And a second interface exists between the candidate middle user plane network element and the access network element.

Illustratively, the candidate user plane network elements comprise candidate anchor user plane function anchor user plane network elements. In another possible embodiment, the first request carries network information of the data network to be accessed by the terminal. Correspondingly, the first response carries the first interface information of the candidate anchor user plane network element. And a third interface exists between the candidate anchor point user plane network element and the data network.

The candidate user plane network elements may include a candidate intermediate user plane function intermediate user plane network element and a candidate anchor user plane function anchor user plane network element, where the candidate intermediate user plane network element is a user plane network element having a second interface with an access network element accessed by the terminal device. In one possible design, the first request carries first interface information of candidate mid-user plane network elements, and the first interface information of the candidate mid-user plane network elements is used to select, from at least one user plane network element, a user plane network element having a first interface with the candidate mid-user plane network element as a candidate anchor user plane network element. Correspondingly, the first response carries the identifier of the candidate anchor user plane network element.

The candidate user plane network elements may include a candidate intermediate user plane function intermediate user plane network element and a candidate anchor user plane function anchor user plane network element, where the candidate anchor user plane network element is a user plane network element having a third interface with a data network to be accessed by the terminal device. In another possible design, the first request carries first interface information of the candidate anchor user plane network element, and the first interface information of the candidate anchor user plane network element is used to select, from at least one user plane network element, a user plane network element having a first interface with the candidate anchor user plane network element as a candidate intermediate user plane network element. Correspondingly, the first response carries the identifier of the candidate middle user plane network element.

The candidate user plane network elements may illustratively include candidate mid-user plane function mid-user plane network elements and candidate anchor user plane function anchor user plane network elements. In yet another possible design, the first request carries network information of an access network element to which the terminal device is accessing and network information of a data network to which the terminal device is accessing. Correspondingly, the first response carries the first interface information of the candidate middle user plane network element and the first interface information of the candidate anchor user plane network element. The candidate intermediate user plane network element is a user plane network element with a second interface between the candidate intermediate user plane network element and an access network element accessed by the terminal equipment, and the candidate anchor point user plane network element is a user plane network element with a third interface between the candidate anchor point user plane network element and a data network accessed by the terminal equipment.

Illustratively, the candidate session management network element may comprise a candidate mid-session management network element. In one possible design, the first request carries network information of an access network element to which the terminal device is accessed. Correspondingly, the first response carries the first interface information of the user plane network element controlled by the candidate middle session management network element. And a second interface exists between the user plane network element controlled by the candidate intermediate session management network element and the access network element.

Illustratively, the candidate session management network element may comprise a candidate anchor session management function anchor session management network element. In another possible embodiment, the first request carries network information of the data network to be accessed by the terminal. Correspondingly, the first response carries the first interface information of the user plane network element controlled by the candidate anchor session management network element. And a third interface exists between the user plane network element controlled by the candidate anchor point session management network element and the data network to be accessed by the terminal equipment.

The candidate session management network elements may include candidate intermediate session management network elements and candidate anchor session management function anchor session management network elements, and among the user plane network elements controlled by the candidate intermediate session management network elements, there is a user plane network element having a second interface with an access network element accessed by the terminal device. In one possible design, the first request carries first interface information of a user plane network element controlled by a candidate middle session management network element, and the first interface information of the user plane network element controlled by the candidate middle session management network element is used for selecting a first user plane network element having a first interface with the user plane network element controlled by the candidate middle session management network element from at least one user plane network element, and selecting a candidate anchor point session management network element from the session management network elements controlling the first user plane network element. Correspondingly, the first response carries the identifier of the candidate anchor session management network element.

The candidate session management network elements may include a candidate intermediate user plane function intermediate session management network element and a candidate anchor session management function anchor session management network element, where a user plane network element having a third interface with a data network to be accessed by the terminal device exists in the user plane network elements controlled by the candidate anchor session management network element. In another possible design, the first request carries first interface information of a user plane network element controlled by the candidate anchor session management network element, and the first interface information of the user plane network element controlled by the candidate anchor session management network element is used for selecting a second user plane network element having a first interface with the user plane network element controlled by the candidate anchor session management network element from at least one user plane network element, and selecting a candidate intermediate session management network element from the session management network elements controlling the second user plane network element. Correspondingly, the first response carries the first interface information of the user plane network element controlled by the candidate middle session management network element.

Illustratively, the candidate session management network elements may include a candidate mid-user plane function mid-session management network element and a candidate anchor user plane function anchor session management network element. In yet another possible design, the first request carries network information of an access network element to which the terminal device is accessing and network information of a data network to which the terminal device is accessing. Correspondingly, the first response carries the first interface information of the user plane network element controlled by the candidate intermediate session management network element and the first interface information of the user plane network element controlled by the candidate anchor session management network element. And the user plane network element controlled by the candidate anchor point session management network element has a user plane network element with a third interface with a data network to be accessed by the terminal equipment.

In a seventh aspect, a communication apparatus is provided, including: a processor; the processor is coupled to the memory and obtains computer instructions from the memory, which when executed by the processor, cause the communication device to perform the communication method of any implementation of any of the above aspects. The communication device may be the session management network element of the first aspect, or a chip system set in the session management network element; alternatively, the communication device may be the access management network element of the second aspect, or a chip system set in the access management network element; alternatively, the communication device may be the network storage network element of the third aspect, or a chip system disposed in the network storage network element.

It should be noted that, for technical effects brought by any one of the design manners in the fourth aspect to the seventh aspect, reference may be made to technical effects brought by different design manners in the first aspect to the third aspect, and details are not described here again.

In an eighth aspect, a communication system is provided. The communication system comprises a plurality of user plane network elements, one or more session management network elements, an access management network element, and a network storage network element. Wherein the session management network element is operable to perform the communication method described in the first aspect or any possible implementation manner of the first aspect; the access management network element may be configured to perform the communication method described in the second aspect or any possible implementation manner of the second aspect; the network storage network element may be configured to perform the communication method described in the third aspect or any possible implementation manner of the third aspect.

In a possible design, the communication system may further include another device or network element, such as a user plane network element, interacting with the session management network element in the first aspect or in the scheme provided in this embodiment of the present application, where the user plane network element may be configured to execute the method performed by the user plane function network element in the scheme provided in this embodiment of the present application.

In a possible design, the communication system may further include another device or network element, such as a session management network element, interacting with the access management network element in the second aspect or in the solution provided in the embodiment of the present application, where the session management network element is configured to perform the method performed by the session management functional network element in the solution provided in the embodiment of the present application.

In a possible design, the communication system may further include another device or network element, such as a session management network element or an access management network element, interacting with the network storage network element in the third aspect or in the solution provided in the embodiment of the present application, where the session management network element or the access management network element may be configured to perform the method performed by the session management function network element in the solution provided in the embodiment of the present application.

It should be noted that, for technical effects brought by any one of the design methods in the eighth aspect, reference may be made to the technical effects brought by the different design methods in the first aspect to the third aspect, and details are not described here again.

In a ninth aspect, there is provided a computer-readable storage medium having stored therein instructions which, when run on a computer, cause the computer to perform the communication method of any of the above aspects.

In a tenth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the communication method of any of the preceding aspects.

Drawings

Fig. 1 is a schematic architecture diagram of a communication system according to an embodiment of the present application;

fig. 2 is a first schematic structural diagram of a communication device according to an embodiment of the present disclosure;

fig. 3 is a first flowchart of a communication method according to an embodiment of the present application;

fig. 4 is a second flowchart illustrating a communication method according to an embodiment of the present application;

fig. 5 is a third schematic flowchart of a communication method according to an embodiment of the present application;

fig. 6 is a fourth flowchart of a communication method according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a communication device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Where in the description of the present application, "/" indicates a relationship where the objects associated before and after are an "or", unless otherwise stated, for example, a/B may indicate a or B; in the present application, "and/or" is only an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. Also, in the description of the present application, "a plurality" means two or more than two unless otherwise specified. "at least one" means one or more, "a plurality" means two or more. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple. In addition, in order to facilitate clear description of technical solutions of the embodiments of the present application, in the embodiments of the present application, terms such as "first" and "second" are used to distinguish the same items or similar items having substantially the same functions and actions. Those skilled in the art will appreciate that the terms "first," "second," etc. do not denote any order or quantity, nor do the terms "first," "second," etc. denote any order or importance.

In addition, the network architecture and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not constitute a limitation to the technical solution provided in the embodiment of the present application, and it can be known by a person skilled in the art that the technical solution provided in the embodiment of the present application is also applicable to similar technical problems along with the evolution of the network architecture and the appearance of a new service scenario.

Fig. 1 is an example of a communication system provided in an embodiment of the present application. Referring to fig. 1, a communication system provided in an embodiment of the present application may generally include the following devices, network elements, and networks:

1. the terminal equipment: may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices or other processing devices connected to a wireless modem with wireless communication capabilities, as well as various forms of terminals, Mobile Stations (MSs), terminals (terminals), User Equipment (UEs), soft terminals, and so forth. Such as water meters, electricity meters, sensors, etc.

2. (radio access network, (R) AN) network element: the method and the device are used for providing a network access function for authorized terminal equipment in a specific area, and can use transmission tunnels with different qualities according to the grade of the terminal equipment, the service requirement and the like.

The (R) AN network element can manage wireless resources and provide access service for the terminal equipment, and then completes the forwarding of control signals and terminal equipment data between the terminal equipment and the core network, and the (R) AN can also be understood as a base station in the traditional network.

3. A user plane network element: for packet routing and forwarding, quality of service (QoS) handling of user plane data, etc.

As shown in fig. 1, in the 5G communication system, the user plane network element may be a User Plane Function (UPF) network element, and may include an intermediate user plane function (I-UPF) network element and an anchor user plane function (a-UPF) network element. In a future communication system, the user plane network element may still be a UPF network element, or may also have another name, which is not limited in this application.

4. Data Network (DN): for providing a network for transmitting data.

As shown in fig. 1, in a 5G communication system, the data networks may be DN1 and DN 2. In future communication systems, the data network may still be the DN, or may have other names, and the present application is not limited thereto.

5. Accessing a management network element: the method is mainly used for mobility management, access management and the like, and can be used for realizing other functions except session management in Mobility Management Entity (MME) functions, such as functions of lawful interception, access authorization/authentication and the like.

As shown in fig. 1, in the 5G communication system, the access management network element may be an access and mobility management function (AMF) network element. In a future communication system, the access management network element may still be an AMF network element, or may also have another name, which is not limited in this application.

6. A session management network element: the method is mainly used for session management, Internet Protocol (IP) address allocation and management of terminal equipment, selection of a termination point capable of managing a user plane function, a policy control and charging function interface, downlink data notification and the like.

As shown in fig. 1, in the 5G communication system, the session management network element may be a Session Management Function (SMF) network element, and may include an intermediate session management function (I-SMF) network element and an anchor session management function (a-SMF) network element. In future communication systems, the session management network element may still be an SMF network element, or may also have another name, which is not limited in this application.

7. The strategy control network element: the unified policy framework is used for guiding network behavior, providing policy rule information for control plane function network elements (such as AMF, SMF network elements and the like), and the like.

In the 4G communication system, the policy control network element may be a Policy and Charging Rules Function (PCRF) network element. As shown in fig. 1, in a 5G communication system, the policy control network element may be a Policy Control Function (PCF) network element. In future communication systems, the policy control network element may still be a PCF network element, or may also have another name, which is not limited in this application.

8. Authenticating the serving network element: the method is used for authentication service and key generation to realize bidirectional authentication of the terminal equipment, and supports a uniform authentication framework.

As shown in fig. 1, in the 5G communication system, the authentication service network element may be an authentication server function (AUSF) network element. In a future communication system, the authentication server function network element may still be an AUSF network element, or may also have another name, which is not limited in this application.

9. A data management network element: the method is used for processing terminal equipment identification, access authentication, registration, mobility management and the like.

As shown in fig. 1, in the 5G communication system, the data management network element may be a Unified Data Management (UDM) network element. In future communication systems, the unified data management may still be a UDM network element, or may also have other names, which is not limited in this application.

10. The application network element: the method is used for carrying out data routing of application influence, accessing to a network open function network element, carrying out strategy control by interacting with a strategy framework and the like.

As shown in fig. 1, in the 5G communication system, the application network element may be an Application Function (AF) network element. In a future communication system, the application network element may still be an AF network element, or may also have another name, which is not limited in this application.

11. A network storage network element: for maintaining real-time information of all network function services in the network.

In the 5G communication system, the network storage network element may be a Network Registration Function (NRF) network element (not shown in fig. 1). In future communication systems, the network storage network element may still be an NRF network element, or may also have another name, which is not limited in this application.

It is to be understood that the above network elements or functions may be network elements in a hardware device, or may be software functions running on dedicated hardware, or virtualization functions instantiated on a platform (e.g., a cloud platform). The network elements or functions may be divided into one or more services and further services may exist independently of the network functions. In the present application, an instance of the above-described function, or an instance of a service included in the above-described function, or an instance of a service existing independently of the network function, may be referred to as a service instance.

Further, the AF network element may be abbreviated as AF, the NRF network element may be abbreviated as NRF, and the PCF network element may be abbreviated as PCF. That is, AF described later in this application may be replaced with an application network element, NRF may be replaced with a network storage network element, and PCF may be replaced with a policy control network element.

For convenience of description, in the present application, a method for UPF selection or SMF selection is described by taking a device as an SMF entity, an AMF entity, or an NRF entity as an example, and for an implementation method in which the device is a chip in the SMF entity, a chip in the AMF entity, or a chip in the NRF entity, reference may be made to specific descriptions of the device as the SMF entity, the AMF entity, or the NRF entity, respectively, and no repeated description is provided.

It should be noted that the embodiment of the present application is not limited to the above system architecture, and may also be applied to other future communication systems, such as the 6th generation (6G) system architecture. In addition, the names of the network elements used in the embodiments of the present application may remain the same in the future communication system, but the names may change.

In addition, although not shown in fig. 1, the communication system may further include other network elements, devices, network entities or network subsystems, such as Binding Support Function (BSF) network elements, and the like, which are not described in detail in this embodiment of the present application.

As shown in fig. 1, the terminal device communicates with the AMF network element via AN N1 interface (abbreviated to N1), communicates with the R AN network element via the Uu interface, (R) the AN network element communicates with the AMF network element via AN N2 interface (abbreviated to N2), communicates with the I-UPF network element via AN N3 interface (abbreviated to N3), the I-UPF network element communicates with the DN1 via AN N6 interface (abbreviated to N6), communicates with the I-SMF network element via AN N4 interface (abbreviated to N4), communicates with the a-UPF network element via AN N9 interface (abbreviated to N9), the a-UPF network element communicates with the DN2 via another N6 interface, communicates with the a-SMF network element via another N4 interface, the AMF network element communicates with the NSSF network element via AN N22 interface (abbreviated to N22), communicates with the AUSF network element via AN N12 interface (abbreviated to N12), communicates with the udsf network element via AN N8269556, communicates with the SMF network element via AN N11, the I-SMF network element communicates with the A-SMF network element through an N16a interface (N16 a for short), the A-SMF network element communicates with the UDM network element through an N10 interface (N10 for short), and communicates with the PCF network element through an N7 interface (N7 for short), the PCF network element communicates with the AF network element through an N5 interface (N5 for short), and the AUSF network element communicates with the UDM network element through an N13 interface (N13 for short). The DN1 is a DN co-located with the terminal device, such as a DN in a service area, and the DN2 is a DN not co-located with the terminal device, i.e., a foreign DN.

Illustratively, the I-UPF network element and the I-SMF network element shown in fig. 1 may be a visited UPF (visited UPF, V-UPF) network element and a visited SMF (visited SMF, V-SMF) network element, respectively, and the a-UPF network element and the a-SMF network element shown in fig. 1 may be a home UPF (home UPF, H-UPF) network element and a home SMF (home SMF, H-SMF) network element, respectively.

It should be noted that the network architecture shown in fig. 1 is a reference point-based network architecture. In fact, control plane network elements such as the AMF network element, the I-SMF network element, the a-SMF network element, the PCF network element, the NSSF network element, the AUSF network element, the UDM network element, and the AF network element shown in fig. 1 may also interact with each other by using a service interface, which is not limited in this embodiment of the present application.

Optionally, various network elements in this embodiment may be communication equipment, or may be a chip or a chip system that can be used in the communication equipment, and this is not limited in this embodiment of the present application.

It should be noted that the various network elements may be different communication devices, or different communication apparatuses, modules, or subsystems in the same communication device, and this is not limited in this embodiment of the present application.

Optionally, the terminal device (terminal) in the embodiment of the present application may be a device for implementing a wireless communication function, for example, a terminal or a chip that can be used in the terminal. The terminal may be a User Equipment (UE), an access terminal, a terminal unit, a terminal station, a mobile station, a distant station, a remote terminal, a mobile device, a wireless communication device, a terminal agent or a terminal device, etc. in a 5G network or a PLMN which is evolved in the future. An access terminal may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having wireless communication capabilities, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, or a wearable device, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and the like. The terminal may be mobile or stationary.

Optionally, the access network device in this embodiment generally includes a device for accessing a core network, for example, a base station, a broadband network service gateway (BNG), an aggregation switch, a non-third generation partnership project (3 GPP) access device, and the like. The base station may include various forms of base stations, such as: macro base stations, micro base stations (also referred to as small stations), relay stations, access points, etc.

Optionally, various network elements, network devices, or terminal devices in the embodiment of the present application may also be referred to as a communication apparatus, which may be a general device or a special device, and this is not specifically limited in the embodiment of the present application.

Optionally, the relevant functions of the policy control network element or the network device in the embodiment of the present application may be implemented by one device, or may be implemented by multiple devices together, or may be implemented by one or more functional modules in one device, which is not specifically limited in this embodiment of the present application. It is understood that the above functions may be network elements in a hardware device, or software functions running on dedicated hardware, or a combination of hardware and software, or virtualization functions instantiated on a platform (e.g., a cloud platform).

For example, the relevant functions of various network elements or network devices or terminal devices in the embodiments of the present application may be implemented by the communication apparatus 200 shown in fig. 2. As shown in fig. 2, the communication device 200 includes one or more processors 201, a communication line 202, and at least one communication interface, and optionally a memory 203.

The processor 201 may be a general-purpose Central Processing Unit (CPU), or a microprocessor or an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs in accordance with the present invention.

The communication link 202 may include a path for connecting different components.

The communication interface 204, which may be a transceiver module, is used for communicating with other devices or communication networks, such as ethernet, RAN, Wireless Local Area Networks (WLAN), etc. For example, the transceiver module may be a transceiver, a transceiver circuit, a transceiver, or the like. Optionally, the communication interface 204 may also be a transceiver circuit located in the processor 201, so as to implement signal input and signal output of the processor.

The memory 203 may be a device having a storage function. Such as, but not limited to, read-only memory (ROM) or other types of static storage devices that may store static information and instructions, Random Access Memory (RAM) or other types of dynamic storage devices that may store information and instructions, electrically erasable programmable read-only memory (EEPROM), compact disk read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory 203 is coupled to the processor 201. For example, the memory 203 may be separate and coupled to the processor 201 via the communication line 202. Also for example, the memory 203 may be integrated with the processor 201.

The memory 203 is used for storing computer execution instructions for executing the scheme of the application, and is controlled by the processor 201 to execute. The processor 201 is configured to execute computer-executable instructions stored in the memory 203, so as to implement the communication method provided in the embodiment of the present application.

Alternatively, in this embodiment of the application, the processor 201 may also execute functions related to processing in the method for implementing communication provided in the following embodiments of the application, and the communication interface 204 is responsible for communicating with other devices or a communication network, which is not specifically limited in this embodiment of the application.

Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application program codes, which are not specifically limited in the embodiments of the present application.

In particular implementations, processor 201 may include one or more CPUs such as CPU0 and CPU1 in fig. 2, for example, as one embodiment.

In particular implementations, communication apparatus 200 may include multiple processors, such as processor 201 and processor 207 in fig. 2, for example, as an example. Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions).

In one implementation, the communications apparatus 200 may further include an output device 205 and an input device 206. The output device 205 is in communication with the processor 201 and may display information in a variety of ways. For example, the output device 205 may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, a projector (projector), or the like. The input device 206 is in communication with the processor 201 and may receive user input in a variety of ways. For example, the input device 206 may be a mouse, a keyboard, a touch screen device, or a sensing device, among others.

The communication apparatus 200 may also be referred to as a communication device, which may be a general-purpose device or a special-purpose device, and the embodiment of the present application does not limit the type of the communication apparatus 200.

The communication method provided by the embodiment of the present application will be specifically described below with reference to fig. 3 to 6. For convenience of understanding, in the following method embodiments, the network element name, the device name, and the network name shown in fig. 1 are used as examples for description. For example, taking an SMF network element, a UPF network element, an AMF network element, and an NRF network element as examples, the functions of the session management network element, the user plane network element, the access management network element, and the network storage network element are respectively described.

It should be noted that, in the following embodiments of the present application, names of messages or names of parameters in messages used for interaction between network elements are only an example; or the name of the service for interaction or the names of the parameters in the service, etc. are only an example, and other names may also be used in the specific implementation, which is not specifically limited in this embodiment of the application.

Fig. 3 is a schematic flowchart of a communication method provided in the present application, which may be applied to a process of selecting a UPF network element by an SMF network element in the communication system shown in fig. 1. As shown in fig. 3, the communication method includes the steps of:

s301, the session management function SMF network element acquires the first control information and the second control information.

The first control information comprises first interface information of at least one candidate I-UPF network element, and the second control information comprises first interface information of at least one candidate A-UPF network element.

Illustratively, the at least one candidate I-UPF network element may be a radio access network RAN for access with the terminal device, such as a UPF network element having a second interface between base stations. Accordingly, the at least one candidate a-UPF network element may be a UPF network element having a third interface with the data network DN to be accessed by the terminal device. Wherein, the first interface refers to an N9 interface between UPF network elements.

In a possible design method, in step S301, the obtaining, by the session management function SMF network element, the first control information and the second control information may include the following steps:

the SMF network element acquires first control information from at least one candidate I-UPF network element or network repository function NRF network element;

the SMF network element acquires the first control information from at least one candidate A-UPF network element or a network repository function NRF network element.

That is, the SMF network element may obtain the first interface information of each candidate UPF network element from the at least one candidate I-UPF network element itself or the at least one candidate a-UPF network element itself, or the NRF network element may obtain the first interface information of each candidate UPF network element.

For example, the SMF network element may send an acquisition request for acquiring the first interface information of each candidate UPF network element to each candidate UPF network element or NRF network element, and receive the first interface information of each candidate UPF network element carried in an acquisition response sent by each candidate UPF network element or NRF network element.

The first interface information of each candidate UPF network element, which is acquired by the SMF network element from the NRF network element, may be the first interface information that is sent by each candidate UPF network element or OAM equipment to the NRF network element in the UPF network element registration process and is centrally stored by the NRF network element. For example, the NRF network element may store the first interface information of each candidate UPF network element in a configuration file of each candidate UPF network element. The configuration file may be a configuration file in various forms such as a spreadsheet, a text file, and the like, and the embodiment of the application is not limited. The detailed implementation manner of collecting and acquiring the first interface information may refer to the related description of the method embodiment on the NRF network element side shown in fig. 5, and is not described herein again.

It should be noted that, in addition to the first interface information, the SMF network element may also obtain the second interface information and/or the third interface information. The second interface information may include network information of a radio access network RAN reachable by each candidate UPF network element, such as an IP address, an equipment identifier, an equipment name, and location information of a radio access network device having an N3 interface with each candidate UPF network element. The third interface information may include an IP address, a network identifier, a network name, location information, and the like of the data network reachable by each candidate UPF network element.

It is easy to understand that in the embodiment of the present application, the candidate I-UPF network element refers to a candidate UPF network element on the user side, and the candidate a-UPF network element refers to a candidate UPF network element on the data network side. Therefore, for the candidate I-UPF network element, the embodiment of the present application does not need to care about the third interface information of the candidate I-UPF network element, and for the candidate a-UPF network element, the embodiment of the present application does not need to care about the second interface information of the candidate a-UPF network element, so as to narrow the selection range of the candidate I-UPF network element and the candidate a-UPF network element, and further improve the efficiency of the SMF network element in selecting the UPF network element.

S302, the SMF network element determines that a first interface exists between the first candidate I-UPF network element and the first candidate A-UPF network element according to the first control information and the second control information.

The first candidate I-UPF network element is a user plane network element in the at least one candidate I-UPF network element, and the first candidate A-UPF network element is a user plane network element in the at least one candidate A-UPF network element.

In one possible design approach, the first control information may include: the IP address set of the Internet protocol of the UPF network element which can be reached by the first interface of the candidate I-UPF network element; the second control information may include: an internet protocol, IP, address of a first interface of at least one candidate a-UPF network element. Correspondingly, in the above S302, the determining, by the SMF network element according to the first control information and the second control information, that the first interface exists between the first candidate I-UPF network element and the first candidate a-UPF network element may include the following steps:

the SMF network element determines that an Internet Protocol (IP) address of a first interface of a first candidate A-UPF network element exists in an Internet Protocol (IP) address set of a UPF network element which can be reached by the first interface of the first candidate I-UPF network element.

Wherein, at least one candidate I-UPF network element can be one candidate I-UPF network element or a plurality of candidate I-UPF network elements. For any one UPF network element in the at least one candidate I-UPF network element, there may be one or more other UPF network elements whose first interface is reachable. Moreover, for different candidate I-UPF network elements, other UPF network elements that are reachable by the respective first interfaces may be the same or different, which is not limited in this embodiment of the present application.

It is assumed that the at least one candidate I-UPF network element comprises a candidate I-UPF network element 1 and a candidate I-UPF network element 2. For example, the other UPF network elements of which the first interface of the candidate I-UPF network element 1 is reachable may include the UPF network element 3 and the UPF network element 4, while the other UPF network elements of which the first interface of the candidate I-UPF network element 2 is reachable may include the UPF network element 4 and the UPF network element 5, and the other UPF network elements of which the first interfaces of both candidate I-UPF network elements are reachable include the UPF network element 4. For another example, the other UPF network elements that the first interface of the candidate I-UPF network element 1 can reach may include the UPF network element 3 and the UPF network element 4, while the other UPF network elements that the first interface of the candidate I-UPF network element 2 can reach may include the UPF network element 5 and the UPF network element 6, and there is no intersection between the sets of UPF network elements that are formed by the other UPF network elements that the first interfaces of the two candidate I-UPF network elements can reach, respectively.

It should be noted that, for the following correspondence between the at least one candidate a-UPF network element and the other UPF network elements whose respective first interfaces of the at least one candidate a-UPF network element are reachable, reference may be made to the relevant description of the correspondence between the at least one candidate I-UPF network element and the UPF network element whose respective first interfaces of the at least one candidate I-UPF network element are reachable, which is not described in detail in this embodiment of the present application.

Illustratively, assume that the set of IP addresses of the UPF network elements reachable by the first interface of the first candidate I-UPF network element is: {192.168.1.xx, 192.168.2.56, 192.168.125.2-192.168.125.25 }, where "xx" represents any IP address in a segment 192.168.1.1-192.168.1.255. If the internet protocol IP address of the first interface of the first candidate a-UPF network element is any one IP address of the network segment 192.168.1.1-192.168.1.255, or 192.168.2.56, or any one IP address of 192.168.125.2-192.168.125.25, it indicates that the first candidate a-UPF network element is a UPF network element that the first candidate I-UPF network element can reach, that is, a first interface exists between two UPF network elements.

In another possible design approach, the first control information may include: an internet protocol, IP, address of a first interface of at least one candidate I-UPF network element; the second control information may include: and the Internet protocol IP address set of the UPF network element which can be reached by the first interface of the at least one candidate A-UPF network element. Correspondingly, in the above S302, the determining, by the SMF network element according to the first control information and the second control information, that the first interface exists between the first candidate I-UPF network element and the first candidate a-UPF network element may include the following steps:

the SMF network element determines that the Internet protocol IP address of the first interface of the first candidate I-UPF network element exists in the Internet protocol IP address set of the UPF network element which can be reached by the first interface of the first candidate A-UPF network element.

Illustratively, assume that the set of IP addresses of the UPF network elements reachable by the first interface of the first candidate a-UPF network element is: {192.168.1.xx, 192.168.2.56, 192.168.125.2-192.168.125.25 }, where "xx" represents any IP address in a segment 192.168.1.1-192.168.1.255. If the internet protocol IP address of the first interface of the first candidate I-UPF network element is any one IP address of the network segment 192.168.1.1-192.168.1.255, or 192.168.2.56, or any one IP address of 192.168.125.2-192.168.125.25, it indicates that the first candidate I-UPF network element is a UPF network element that the first candidate a-UPF network element can reach, that is, a first interface exists between two UPF network elements.

The IP address of each candidate UPF network element refers to an IP address allocated by the network to one UPF network element, and the IP address set of other UPF network elements that one UPF network element can reach includes IP addresses of other UPF network elements having a first interface with the one UPF network element. The set of IP addresses may be a set of one or more IP addresses, one or more network segments, or a set of one or more IP addresses plus one or more network segments. The network segment may be represented by IP address prefix plus prefix length, such as: IP address prefix/IP address prefix length, or in the form of an IP address plus a mask, such as: IP address/address mask. The network segments may also take the form of network segment first and last addresses, such as: the network segment head address to network segment end address, for example, when the IP address set includes a plurality of consecutive IP addresses, may be represented in the form of a start IP address + an end IP address, such as the above IP address segment: 192.168.125.2-192.168.125.25.

In one possible design approach, the first control information may include: an identification set of a data center DC with a reachable first interface of at least one candidate I-UPF network element; the second control information may include: an identification of the data center DC where the at least one candidate a-UPF network element is located. Correspondingly, in the above S302, the determining, by the SMF network element according to the first control information and the second control information, that the first interface exists between the first candidate I-UPF network element and the first candidate a-UPF network element may include the following steps:

the SMF network element determines that the identification of the data center DC where the first candidate A-UPF network element is located exists in the identification set of the data center DC where the first interface of the first candidate I-UPF network element is reachable.

Exemplarily, it is assumed that the set of identities of the data center DC reachable by the first interface of the first candidate I-UPF network element is: { DC1, DC3, DC6 }. If the identifier of the data center DC where the first candidate a-UPF network element is located is any one of the identifiers DC1, DC3, and DC6 of the data center DC, it indicates that the first candidate a-UPF network element is located in the data center DC where the first candidate I-UPF network element is reachable, that is, there is a first interface between the two UPF network elements.

In another possible design approach, the first control information may include: an identification of a data center DC where the at least one candidate I-UPF network element is located; the second control information may include: an identification set of data centers DC reachable by the first interface of the at least one candidate a-UPF network element. Correspondingly, in the above S302, the determining, by the SMF network element according to the first control information and the second control information, that the first interface exists between the first candidate I-UPF network element and the first candidate a-UPF network element may include the following steps:

the SMF network element determines that the identification of the data center DC where the first candidate I-UPF network element is located exists in the identification set of the data center DC where the first interface of the first candidate A-UPF network element is reachable.

Illustratively, the set of identities of the data center DC reachable by the first interface of the first candidate a-UPF network element is: { DC0, DC2, DC5 }. If the identifier of the data center DC where the first candidate I-UPF network element is located is any one of the above-mentioned data center DC identifiers DC0, DC2, and DC5, it indicates that the first candidate I-UPF network element is located in the data center DC where the first candidate I-UPF network element is reachable, that is, there is a first interface between the two UPF network elements.

The identifier of the data center DC may be an instance identifier of one data center DC, a name of the data center, and other character strings represented by different combinations of characters such as numbers, underlines, and english letters, and used for representing the identity of the data center DC.

In one possible design approach, the first control information may include: an identification set of a UPF network element which can be reached by a first interface of at least one candidate I-UPF network element; the second control information may include: an identification of at least one candidate a-UPF network element. Correspondingly, in the above S302, the determining, by the SMF network element according to the first control information and the second control information, that the first interface exists between the first candidate I-UPF network element and the first candidate a-UPF network element may include the following steps:

and the SMF network element determines that the identifier of the first candidate A-UPF network element exists in the identifier set of the UPF network element which can reach the first interface of the first candidate I-UPF network element.

Exemplarily, the identification set of the UPF network element reachable by the first interface of the first candidate I-UPF network element is assumed to be: { UPF-ID1, UPF-ID8, UPF-ID29 }. And if the identifier of the first candidate A-UPF network element is any one of the identifiers UPF-ID1, UPF-ID8 and UPF-ID29 of the reachable UPF network element, the first candidate A-UPF network element is represented as the reachable UPF network element of the first candidate I-UPF network element, that is, a first interface exists between the two UPF network elements.

In another possible design approach, the first control information may include: an identification of at least one candidate I-UPF network element; the second control information may include: and the identification set of the UPF network elements which can be reached by the first interface of the at least one candidate A-UPF network element. Correspondingly, in the above S302, the determining, by the SMF network element according to the first control information and the second control information, that the first interface exists between the first candidate I-UPF network element and the first candidate a-UPF network element may include the following steps:

and the SMF network element determines that the identifier of the first candidate I-UPF network element exists in the identifier set of the UPF network element which can reach the first interface of the first candidate A-UPF network element.

Exemplarily, it is assumed that the identification set of the UPF network element reachable by the first interface of the first candidate a-UPF network element is: { UPF-ID3, UPF-ID15, UPF-ID48 }. And if the identifier of the first candidate I-UPF network element is any one of the identifiers UPF-ID1, UPF-ID8 and UPF-ID29 of the reachable UPF network element, the first candidate I-UPF network element is the reachable UPF network element of the first candidate A-UPF network element, that is, a first interface exists between the two UPF network elements.

The identifier of each candidate UPF network element may be an instance identifier of the UPF network element, a network element name, and a character string representing the identity of the UPF network element, which is represented by different combinations of characters such as numbers, underlines, and english letters.

In one possible design approach, the first control information may include: a location set of UPF network elements that are reachable by a first interface of at least one candidate I-UPF network element; the second control information may include: a location of at least one candidate a-UPF network element. Correspondingly, in the above S302, the determining, by the SMF network element according to the first control information and the second control information, that the first interface exists between the first candidate I-UPF network element and the first candidate a-UPF network element may include the following steps:

and the SMF network element determines that the position of the candidate first A-UPF network element exists in the position set of the UPF network element which can be reached by the first interface of the first candidate I-UPF network element.

Illustratively, the location set of the UPF network element reachable by the first interface of the first candidate I-UPF network element is assumed to be: { SMF _ zone _ ID, SMF _ set _ ID }, where SMF _ zone _ ID and SMF _ set _ ID are service area identities or service set identities, respectively, of an SMF network element controlling the reachable UPF network element. And if the position of the first candidate A-UPF network element is any one of the positions SMF _ zone _ ID and SMF _ set _ ID of the reachable UPF network element, the first candidate A-UPF network element is the reachable UPF network element of the first candidate I-UPF network element, namely a first interface exists between the two UPF network elements.

In another possible design approach, the first control information may include: a location of at least one candidate I-UPF network element; the second control information may include: a set of locations of UPF network elements reachable by the first interface of the at least one candidate A-UPF network element. Correspondingly, in the above S302, the determining, by the SMF network element according to the first control information and the second control information, that the first interface exists between the first candidate I-UPF network element and the first candidate a-UPF network element may include the following steps:

and the SMF network element determines that the position of the first candidate I-UPF network element exists in the position set of the UPF network element which can be reached by the first interface of the first candidate A-UPF network element.

Exemplarily, the location set of the UPF network element reachable by the first interface of the first candidate a-UPF network element is assumed to be: { SMF _ zone _ ID, SMF _ set _ ID }, where SMF _ zone _ ID and SMF _ set _ ID are service area identities or service set identities, respectively, of an SMF network element controlling the reachable UPF network element. And if the position of the first candidate I-UPF network element is any one of the positions SMF _ zone _ ID and SMF _ set _ ID of the reachable UPF network element, the first candidate I-UPF network element is the reachable UPF network element of the first candidate A-UPF network element, namely a first interface exists between the two UPF network elements.

The location of each candidate UPF network element may be a service area identifier or a service set identifier of the SMF network element that controls the UPF network element, or a service area identifier or a service set identifier of the SMF network element that is represented by different combinations of characters such as numbers, underlines, and english letters and used for representing and controlling the UPF network element.

It should be noted that, in addition to the IP address, the identifier, the location, the identifier of the data center DC, and the identifier of the data network DN, the first interface information may also include other information that can be used to indicate whether the first interface exists between the candidate I-UPF network element and the candidate a-UPF network element, and details are not repeated here.

S303, the SMF network element selects a first candidate I-UPF network element and a first candidate A-UPF network element as a target UPF network element.

Optionally, the first interface information may further include interface parameter information of an N9 interface of the candidate UPF network element, such as at least one of bandwidth, interface type (e.g., optical fiber, network cable, wireless, coaxial cable, etc.), weight, and load. Correspondingly, the SMF network element may also preferentially select the target UPF network element according to the interface parameter information. For example, the SMF network element may select a group of candidate UPF network elements with higher bandwidth, higher interface data rate, higher weight and lower load as the target UPF network element from a plurality of candidate UPF network element combinations { candidate I-UPF network element + candidate a-UPF network element } satisfying the existence of the first interface described in S302. The candidate I-UPF network element and the candidate a-UPF network element in each candidate UPF network element combination may be one or multiple, and this is not limited in this embodiment of the present application.

In the communication method provided by the application, the SMF network element firstly determines that a first interface exists between a first candidate I-UPF network element in the at least one candidate I-UPF network element and a first candidate A-UPF network element in the at least one candidate A-UPF network element according to the first interface information of the at least one candidate I-UPF network element and the first interface information of the at least one candidate A-UPF network element, then the first candidate I-UPF network element and the first candidate a-UPF network element are selected as target UPF network elements, the situation that the normal session connection cannot be established due to the absence of the first interface between two or more UPF network elements selected by the SMF network element can be avoided, and signaling waste, resource waste and time waste caused by that the appropriate target UPF network element can be selected only through multiple interactions can be reduced, and the reliability and efficiency of the selection of the UPF network element by the SMF network element can be improved.

Fig. 4 is a schematic flowchart of another communication method provided in this application, which may be applied to a process of selecting an SMF network element performed by an AMF network element in the communication system shown in fig. 1. As shown in fig. 4, the communication method includes the steps of:

s401, the access and mobility management function AMF network element acquires the third control information and the fourth control information.

The third control information comprises first interface information of a user plane function UPF network element controlled by at least one candidate intermediate session management function I-SMF network element, and the fourth control information comprises first interface information of a user plane function UPF network element controlled by at least one candidate anchor session management function A-SMF network element.

Illustratively, the at least one candidate I-SMF network element may be: and the SMF network element of the UPF network element with the second interface between the controlled UPF network element and the radio access network RAN accessed by the terminal equipment exists in the controlled UPF network elements. Accordingly, the at least one candidate a-SMF network element may be: and the SMF network element of the UPF network element with a third interface between the controlled UPF network element and the data network DN to be accessed by the terminal equipment exists in the controlled UPF network element. The first interface refers to an N9 interface between UPF network elements controlled by the candidate SMF network elements.

In a possible design method, in the step S401, the accessing and mobility management function AMF network element obtaining the third control information and the fourth control information may include the following steps:

the AMF network element acquires third control information from a network repository function NRF network element or at least one candidate I-SMF network element;

the AMF network element obtains the fourth control information from the network repository function NRF network element or the at least one candidate a-SMF network element.

That is, the AMF network element may obtain the first interface information of the UPF network element controlled by each candidate SMF network element from the at least one candidate I-SMF network element itself or the at least one candidate a-SMF network element itself, or the NRF network element may obtain the first interface information of the UPF network element controlled by each candidate SMF network element.

For example, the AMF network element may send an acquisition request for acquiring the first interface information of the UPF network element controlled by each candidate SMF network element to each candidate SMF network element or NRF network element, and receive the first interface information of the UPF network element controlled by each candidate SMF network element, which is carried in an acquisition response sent by each candidate SMF network element or NRF network element.

The first interface information of each candidate SMF network element, which is obtained by the AMF network element from the NRF network element, may be first interface information that is sent by a UPF network element or OAM equipment controlled by each candidate SMF network element to the NRF network element in a UPF network element registration process and is stored in the NRF network element in a centralized manner, or first interface information that is sent by a UPF network element controlled by each candidate SMF network element to a candidate SMF network element and is sent by the candidate SMF network element to the NRF network element and is stored in the NRF network element in a centralized manner, or first interface information that is sent by a UPF network element or OAM equipment controlled by each candidate SMF network element to the NRF network element and is sent by the NRF network element to the candidate SMF network element after the first interface information of the UPF network element is sent to the candidate SMF network element, the candidate SMF network element summarizes the first interface information of each UPF network element controlled by the candidate SMF network element and then reselects to the NRF network element and stores the first interface information. For example, the NRF network element may store the first interface information of the UPF network element controlled by each candidate SMF network element in the configuration file of each candidate SMF network element. The configuration file may be a configuration file in various forms such as a spreadsheet, a text file, and the like, and the embodiment of the application is not limited. The detailed implementation manner of collecting and acquiring the first interface information may refer to the related description of the method embodiment on the NRF network element side shown in fig. 5, and is not described herein again.

It should be noted that the UPF network elements controlled by the candidate SMF network elements include one or more UPF network elements.

In addition, in addition to the first interface information, the AMF network element may also obtain second interface information and/or third interface information of the UPF network element controlled by each candidate SMF network element. The second interface information may include network information of a radio access network RAN reachable by a UPF network element controlled by each candidate SMF network element, such as an IP address, an equipment identifier, an equipment name, location information, and the like of a radio access network device having an N3 interface with the UPF network element controlled by each candidate SMF network element. The third interface information may include an IP address, a network identifier, a network name, location information, and the like of the data network reachable by the UPF network element controlled by each candidate SMF network element.

It is easily understood that, in the embodiment of the present application, the candidate I-SMF network element refers to a candidate SMF network element on the user side, and the candidate a-SMF network element refers to a candidate SMF network element on the data network side. Therefore, for the candidate I-SMF network element, the embodiment of the present application does not need to care about the third interface information of the UPF network element controlled by the candidate I-SMF network element, and for the candidate a-SMF network element, the embodiment of the present application does not need to care about the second interface information of the UPF network element controlled by the candidate a-SMF network element, so as to narrow the selection ranges of the candidate I-SMF network element and the candidate a-SMF network element, and further improve the efficiency of the AMF network element for selecting the SMF network element.

And S402, the AMF network element determines that a first interface exists between the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate A-SMF network element according to the third control information and the fourth control information.

The first candidate I-SMF network element is an SMF network element in the at least one candidate I-SMF network element, and the first candidate A-SMF network element is an SMF network element in the at least one candidate A-SMF network element.

In one possible design approach, the third control information may include: the IP address set of the Internet protocol of the UPF network element which is reachable by the first interface of the UPF network element controlled by the at least one candidate I-SMF network element; the fourth control information may include: an internet protocol, IP, address of a first interface of a UPF network element controlled by the at least one candidate a-SMF network element. Correspondingly, in step S402, the determining, by the AMF network element, that the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate a-SMF network element have the first interface according to the third control information and the fourth control information may include the following steps:

and the AMF network element determines that the Internet protocol IP address of the first interface of the UPF network element controlled by the first candidate A-SMF network element exists in the Internet protocol IP address set of the UPF network element which can be reached by the first interface of the UPF network element controlled by the first candidate I-SMF network element.

Wherein, at least one candidate I-SMF network element may be one candidate I-SMF network element or a plurality of candidate I-SMF network elements. For any one SMF network element in the at least one candidate I-SMF network element, the SMF to which the other UPF network element whose controlled UPF network element has the reachable first interface belongs may be one or multiple. Moreover, for different candidate I-SMF network elements, the SMF network elements to which other UPF network elements that can respectively control the first interface of the UPF network element belong may be the same or different, which is not limited in this embodiment of the present application.

It is assumed that the at least one candidate I-SMF network element comprises candidate I-SMF network element 1 and candidate I-SMF network element 2. For example, the SMF network elements to which the other UPF network elements whose first interfaces of the UPF network elements controlled by the candidate I-SMF network element 1 are reachable may include the SMF network element 3 and the SMF network element 4, the SMF network elements to which the other UPF network elements whose first interfaces of the UPF network elements controlled by the candidate I-SMF network element 1 are reachable may include the SMF network element 4 and the SMF network element 5, and the SMF network elements to which the other UPF network elements whose first interfaces of the UPF network elements controlled by the two candidate I-SMF network elements are reachable both include the SMF network element 4. For another example, the SMF network elements to which the other UPF network elements whose first interfaces of the UPF network elements controlled by the candidate I-SMF network element 1 are reachable may include the SMF network element 3 and the SMF network element 4, the SMF network elements to which the other UPF network elements whose first interfaces of the UPF network elements controlled by the candidate I-SMF network element 1 are reachable may include the SMF network element 5 and the SMF network element 6, and there is no intersection between the sets of the SMF network elements consisting of the SMF network elements to which the other UPF network elements whose first interfaces of the UPF network elements controlled by the two candidate I-SMF network elements are reachable.

It should be noted that, for the following correspondence between the at least one candidate a-SMF network element and the SMF network element to which the UPF network element controlled by the at least one candidate a-SMF network element respectively has the first interface reachable, the other UPF network element to which the UPF network element controlled by the at least one candidate I-SMF network element respectively has the first interface reachable, may refer to the description of the correspondence between the at least one candidate I-SMF network element and the other SMF network element to which the UPF network element controlled by the at least one candidate I-SMF network element respectively has the first interface reachable, and this embodiment is not described again in this application.

Illustratively, assume that the IP address set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate I-SMF network element is: {192.168.1.xx, 192.168.2.56, 192.168.125.2-192.168.125.25 }, where "xx" represents any IP address in a segment 192.168.1.1-192.168.1.255. If the internet protocol IP address of the first interface of the UPF network element controlled by the first candidate a-SMF network element is any one or more IP addresses in the network segments 192.168.1.1-192.168.1.255, or 192.168.2.56, or 192.168.125.2-192.168.125.25, it indicates that the UPF network element controlled by the first candidate a-SMF network element is a UPF network element reachable by the UPF network element controlled by the first candidate I-SMF network element, that is, there is a first interface between the UPF network elements controlled by the two candidate SMF network elements.

In another possible design approach, the third control information may include: an Internet Protocol (IP) address of a first interface of a UPF network element controlled by at least one candidate I-SMF network element; the fourth control information may include: and the IP address set of the Internet protocol of the UPF network element which can be reached by the first interface of the UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, in step S402, the determining, by the AMF network element, that the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate a-SMF network element have the first interface according to the third control information and the fourth control information may include the following steps:

and the AMF network element determines that the Internet protocol IP address of the first interface of the UPF network element controlled by the first candidate I-SMF network element exists in the Internet protocol IP address set of the UPF network element which can be reached by the first interface of the UPF network element controlled by the first candidate A-SMF network element.

Illustratively, assume that the IP address set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate a-SMF network element is: {192.168.1.xx, 192.168.2.56, 192.168.125.2-192.168.125.25 }, where "xx" represents any IP address in a segment 192.168.1.1-192.168.1.255. If the internet protocol IP address of the first interface of the UPF network element controlled by the first candidate I-SMF network element is any one or more IP addresses in the network segments 192.168.1.1-192.168.1.255, or 192.168.2.56, or 192.168.125.2-192.168.125.25, it indicates that the UPF network element controlled by the first candidate I-SMF network element is a UPF network element reachable by the UPF network element controlled by the first candidate a-SMF network element, that is, there is a first interface between the UPF network elements controlled by the two candidate SMF network elements.

The IP address of the UPF network element controlled by each candidate SMF network element refers to an IP address allocated by the network to a UPF network element controlled by one SMF network element, and the IP address set of UPF network elements controlled by other SMF network elements that the UPF network element controlled by one SMF network element can reach includes IP addresses of UPF network elements controlled by other SMF network elements having a first interface with the UPF network element controlled by one SMF network element. The set of IP addresses may be a set of one or more IP addresses, one or more network segments, or a set of one or more IP addresses plus one or more network segments. The network segment may be represented by IP address prefix plus prefix length, such as: IP address prefix/IP address prefix length, or in the form of an IP address plus a mask, such as: IP address/address mask. The network segments may also take the form of network segment first and last addresses, such as: the network segment head address to network segment end address, for example, when the IP address set includes a plurality of consecutive IP addresses, may be represented in the form of a start IP address + an end IP address, such as the above IP address segment: 192.168.125.2-192.168.125.25.

In one possible design approach, the third control information may include: the identification set of the data center DC with the reachable first interface of the UPF network element controlled by the at least one candidate I-SMF network element; the fourth control information may include: an identification of a data center DC where the UPF network element controlled by the at least one candidate a-SMF network element is located. Correspondingly, in step S402, the determining, by the AMF network element, that the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate a-SMF network element have the first interface according to the third control information and the fourth control information may include the following steps:

and the AMF network element determines that the identification of the data center DC where the UPF network element controlled by the first candidate A-SMF network element is located exists in the identification set of the data center DC where the first interface of the UPF network element controlled by the first candidate I-SMF network element is reachable.

Exemplarily, the set of identities of the data center DC reachable by the first interface of the UPF network element controlled by the first candidate I-SMF network element is assumed to be: { DC1, DC3, DC6 }. If the identifier of the data center DC where the UPF network element controlled by the first candidate a-SMF network element is located is any one of the identifiers DC1, DC3, and DC6 of the data center DC, it indicates that the UPF network element controlled by the first candidate a-SMF network element is located in the data center DC where the UPF network element controlled by the first candidate I-SMF network element is reachable, that is, a first interface exists between the two UPF network elements.

In another possible design approach, the third control information may include: an identifier of a data center DC where a UPF network element controlled by at least one candidate I-SMF network element is located; the fourth control information may include: and the identification set of the data center DC which is reachable by the first interface of the UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, in step S402, the determining, by the AMF network element, that the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate a-SMF network element have the first interface according to the third control information and the fourth control information may include the following steps:

and the AMF network element determines that the identification of the data center DC where the UPF network element controlled by the first candidate I-SMF network element is located exists in the identification set of the data center DC where the first interface of the UPF network element controlled by the first candidate A-SMF network element is reachable.

Exemplarily, the set of identities of the data center DC reachable by the first interface of the UPF network element controlled by the first candidate a-SMF network element is assumed to be: { DC1, DC3, DC6 }. If the identifier of the data center DC where the UPF network element controlled by the first candidate I-SMF network element is located is any one of the identifiers DC1, DC3, and DC6 of the data center DC, it indicates that the UPF network element controlled by the first candidate I-SMF network element is located in the data center DC where the UPF network element controlled by the first candidate a-SMF network element is reachable, that is, a first interface exists between the two UPF network elements.

In one possible design approach, the third control information may include: the identification set of the UPF network element which is controlled by at least one candidate I-SMF network element and can reach the first interface of the UPF network element; the fourth control information may include: an identification of a UPF network element controlled by at least one candidate A-SMF network element. Correspondingly, in step S402, the determining, by the AMF network element, that the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate a-SMF network element have the first interface according to the third control information and the fourth control information may include the following steps:

and the AMF network element determines that the identifier of the UPF network element controlled by the first candidate A-SMF network element exists in the identifier set of the UPF network element which is reachable by the first interface of the UPF network element controlled by the first candidate I-SMF network element.

Exemplarily, the identification set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate I-SMF network element is assumed to be: { UPF-ID1, UPF-ID8, UPF-ID29 }. And if the identifier of the UPF network element controlled by the first candidate A-SMF network element is any one of the identifiers UPF-ID1, UPF-ID8 and UPF-ID29 of the reachable UPF network element, the UPF network element controlled by the first candidate A-SMF network element is the reachable UPF network element of the UPF network element controlled by the first candidate I-SMF network element, that is, a first interface exists between the UPF network elements controlled by the two candidate SMF network elements.

In another possible design approach, the third control information may include: an identifier of a UPF network element controlled by at least one candidate I-SMF network element; the fourth control information may include: and the identifier set of the UPF network element which is reachable by the first interface of the UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, in step S402, the determining, by the AMF network element, that the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate a-SMF network element have the first interface according to the third control information and the fourth control information may include the following steps:

and the AMF network element determines that the identifier of the UPF network element controlled by the first candidate I-SMF network element exists in the identifier set of the UPF network element which is reachable by the first interface of the UPF network element controlled by the first candidate A-SMF network element.

Exemplarily, the identification set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate a-SMF network element is assumed to be: { UPF-ID1, UPF-ID8, UPF-ID29 }. And if the identifier of the UPF network element controlled by the first candidate I-SMF network element is any one of the identifiers UPF-ID1, UPF-ID8 and UPF-ID29 of the reachable UPF network element, the UPF network element controlled by the first candidate I-SMF network element is the reachable UPF network element of the UPF network element controlled by the first candidate A-SMF network element, that is, a first interface exists between the UPF network elements controlled by the two candidate SMF network elements.

The identifier of the UPF network element controlled by each candidate SMF network element may be an example identifier and a network element name of the UPF network element controlled by the candidate SMF network element, or another character string represented by different combinations of characters such as numbers, underlines, and english letters and used for representing the identity of the UPF network element.

In one possible design approach, the third control information may include: the position set of the UPF network element which is controlled by at least one candidate I-SMF network element and can be reached by the first interface of the UPF network element; the fourth control information may include: a location of a UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, in step S402, the determining, by the AMF network element, that the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate a-SMF network element have the first interface according to the third control information and the fourth control information may include the following steps:

and the AMF network element determines that the position of the UPF network element controlled by the first candidate A-SMF network element exists in the position set of the UPF network element which is reachable by the first interface of the UPF network element controlled by the first candidate I-SMF network element.

Illustratively, the location set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate I-SMF network element is assumed to be: { SMF _ zone _ ID, SMF _ set _ ID }, where SMF _ zone _ ID and SMF _ set _ ID are service area identities or service set identities, respectively, of an SMF network element controlling the reachable UPF network element. And if the position of the UPF network element controlled by the first candidate A-SMF network element is any one of the position SMF _ zone _ ID and the position SMF _ set _ ID of the reachable UPF network element, the UPF network element controlled by the first candidate A-SMF network element is the reachable UPF network element of the UPF network element controlled by the first candidate I-SMF network element, namely a first interface exists between the UPF network elements controlled by the two candidate SMF network elements.

In another possible design approach, the third control information may include: a location of a UPF network element controlled by at least one candidate I-SMF network element; the fourth control information may include: and the position set of the UPF network element which is reachable by the first interface of the UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, in step S402, the determining, by the AMF network element, that the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate a-SMF network element have the first interface according to the third control information and the fourth control information may include the following steps:

and the AMF network element determines that the position of the UPF network element controlled by the first candidate I-SMF network element exists in the position set of the UPF network element which is reachable by the first interface of the UPF network element controlled by the first candidate A-SMF network element.

Illustratively, the location set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate a-SMF network element is assumed to be: { SMF _ zone _ ID, SMF _ set _ ID }, where SMF _ zone _ ID and SMF _ set _ ID are service area identities or service set identities, respectively, of an SMF network element controlling the reachable UPF network element. And if the position of the UPF network element controlled by the first candidate I-SMF network element is any one of the positions SMF _ zone _ ID and SMF _ set _ ID of the reachable UPF network element, the UPF network element controlled by the first candidate I-SMF network element is the reachable UPF network element of the UPF network element controlled by the first candidate A-SMF network element, namely a first interface exists between the UPF network elements controlled by the two candidate SMF network elements.

The location of the UPF network element controlled by each candidate SMF network element may be a service area identifier or a service set identifier of each candidate SMF network element, or a service area identifier or a service set identifier represented by different combinations of numbers, underlines, english letters, and other characters and used for representing each candidate SMF network element.

It should be noted that, in addition to the IP address, the identifier, the location, the identifier of the data center DC, and the identifier of the data network DN, the first interface information may also include other information that can be used to indicate whether the first interface exists between the UPF network element controlled by the candidate I-SMF network element and the UPF network element controlled by the candidate a-SMF network element, which is not described herein again.

And S403, the AMF network element selects the first candidate I-SMF network element and the first candidate A-SMF network element as a target SMF network element.

Optionally, the first interface information may further include interface parameter information of an N9 interface of a UPF network element controlled by the candidate SMF network element, such as at least one of bandwidth, interface type (e.g., optical fiber, network cable, wireless, coaxial cable, etc.), weight, and load. Correspondingly, the AMF network element may also preferentially select the target SMF network element according to the interface parameter information. For example, the AMF network element may select, as the target SMF network element, a group of candidate SMF network elements having a larger bandwidth, a higher interface data rate, a larger weight, and a smaller load from a plurality of candidate SMF network element combinations { candidate I-SMF network element + candidate a-SMF network element } in which the first interface exists between the UPF network elements satisfying the control described in S402. The number of the candidate I-SMF network elements and the number of the candidate a-SMF network elements in each candidate SMF network element combination may be one or multiple, which is not limited in the embodiment of the present application.

According to the communication method provided by the application, the AMF network element firstly determines that a first interface exists between the UPF network element controlled by the first candidate I-SMF network element and the UPF network element controlled by the first candidate A-SMF network element in the at least one candidate A-SMF network element according to the first interface information of the UPF network element controlled by the first candidate I-SMF network element in the at least one candidate I-SMF network element and the first interface information of the UPF network element controlled by the first candidate A-SMF network element in the at least one candidate A-SMF network element, then selects the first candidate I-SMF network element and the first candidate A-SMF network element as the target SMF network element, can avoid the situation that normal session connection cannot be established due to the fact that the first interface does not exist between the UPF network elements controlled by two or more than two SMF network elements selected by the AMF network element, and can reduce the situation that signaling waste, and signaling waste, caused by the fact that the target, The resource waste and the time waste can improve the reliability and the efficiency of the AMF network element for selecting the SMF network element.

Fig. 5 is a flowchart of another communication method provided by the present application, which may be applied to the NRF network element in the communication system shown in fig. 1, and provide the first interface information or the candidate UPF network element or the candidate SMF network element in the process of selecting the UPF network element by the SMF network element or in the process of selecting the SMF network element by the AMF network element. That is, the NRF network element may assist the SMF network element to complete the UPF network element selection procedure shown in fig. 3, or assist the AMF network element to complete the SMF network element selection procedure shown in fig. 4. As shown in fig. 5, the communication method includes the steps of:

s501, the network repository function NRF network element receives and stores the first interface information of at least one user plane function UPF network element.

The first interface information includes an identifier of a UPF network element that is reachable by the UPF network element in the at least one UPF network element.

For example, the at least one UPF network element includes a UPF1, a UPF2, and a UPF3, and the first interface information may include: identification of UPF network elements reachable by the UPF1 (e.g. identification of UPF4, identification of UPF 5); UPF network element identification (such as identification of UPF5 and identification of UPF 6) with which the UPF2 is reachable; UPF network element identification (such as identification of UPF4 and identification of UPF 6) reachable by the UPF3, and the like.

In a possible design method, as shown in fig. 6, in the above S501, the network repository function NRF network element receives the first interface information of the at least one user plane function UPF network element, which may include at least one of the following:

s601, the NRF network element receives the first interface information sent by at least one UPF network element.

For example, the UPF network element may actively send the first interface information of the UPF network element itself to the NRF network element in a process of executing a registration procedure after powering on the NRF network element. It is easy to understand that, when the configuration of the first interface information of the UPF network element changes, the UPF network element may also actively send the updated first interface information to the NRF network element.

Optionally, when the NRF network element discovers a UPF network element newly added in the network, for example, discovers a UPF network element that has just been powered on or has executed a registration process, or when the NRF network element learns that the first interface information of some UPF network elements changes, if the NRF network element discovers that the UPF network element 2 that originally has the first interface with the UPF network element 1 has a fault or has been powered off, the NRF network element may also send an update instruction of the first interface information to the newly added UPF network element or the UPF network element that has changed the first interface information.

S602, the NRF network element receives the first interface information of the at least one UPF network element, which is sent by the operation, administration and maintenance OAM equipment.

Illustratively, the OAM device may actively send the first interface information of the UPF network element managed by the OAM device to the NRF network element in the process of performing the registration procedure for the UPF network element managed by the OAM device. It is easy to understand that, when the configuration of the first interface information of the UPF network element managed by the OAM equipment changes, the UPF network element managed by the OAM equipment may also actively send the updated first interface information to the NRF network element again.

Optionally, when the NRF network element discovers a UPF network element newly added in the network, for example, discovers a UPF network element that has just been powered on or is executing a registration process, or when the NRF network element learns that the first interface information of some UPF network elements changes, if the NRF network element discovers that the UPF network element 2 that originally has the first interface with the UPF network element 1 has a fault or has been powered off, the NRF network element may also send an update instruction of the first interface information to the OAM device.

S603, the NRF network element receives the first interface information of the UPF network element controlled by the at least one SMF network element, which is sent by the at least one SMF network element.

In a possible design method, the SMF network element may actively send the first interface information of the UPF network element controlled by the SMF network element to the NRF network element. It is easy to understand that, when the configuration of the first interface information of the UPF network element controlled by the SMF network element changes, the SMF network element may also actively send the updated first interface information of the UPF network element controlled by the SMF network element to the NRF network element.

For example, in the process of the SMF network element performing the UPF selection procedure shown in fig. 3, if the SMF network element finds that the configuration of the first interface information of the candidate I-UPF network element and/or the candidate a-UPF network element is incorrect, the SMF network element may also actively send correct first interface information to the NRF network element.

In this embodiment of the present application, in the process of the AMF network element performing the SMF network element selection procedure shown in fig. 4, if the AMF network element finds that the configuration of the first interface information of the UPF network element controlled by the candidate I-SMF network element and/or the candidate a-SMF network element is incorrect, the AMF network element may also notify the SMF network element of the UPF network element whose configuration information is incorrect, and send correct first interface information to the NRF network element.

It should be noted that, as to whether or not the above S601-S603 are executed, and the execution sequence may be determined by the UPF network element, the OAM equipment, the SMF network element, and the NRF network element, and the embodiment of the present application is not limited in any way.

After performing at least one of the above S601-S603, the NRF network element may perform the following steps:

s604, the NRF network element stores the received first interface information of the UPF network element.

Illustratively, the NRF network element may store the received first interface information in the form of a configuration file or the like.

Optionally, the NRF network element may establish one UPF configuration file for each UPF network element.

Optionally, the NRF network element may respectively establish an SMF configuration file for each SMF network element, where the SMF configuration file is used to store the first interface information of the UPF network element having the first interface with the external UPF network element in all the UPF network elements controlled by the SMF network element. Wherein, the external UPF network element refers to a UPF network element which is not controlled by the SMF network element.

In addition, the configuration file may further store second interface information and third interface information of the UPF network element. The second interface information includes network information of the radio access network RAN that each UPF network element can reach, such as a device identifier, an IP address, a device name, a service area identifier, and the like of a base station in the radio access network RAN. The third interface information includes network information of the data network DN that each UPF network element can reach, such as a network identifier, an IP address, a data server name, and the like of the data network.

It should be noted that the NRF network element may also store the first interface information, the second interface information, and the third interface information in other file forms, such as a script, a spreadsheet, and the like, which is not limited in this embodiment of the present application.

S502, the NRF network element receives the first request.

The first request is used for acquiring first interface information of a candidate UPF network element in at least one UPF network element, or the first request is used for requesting to select the candidate UPF network element from the at least one UPF network element, or the first request is used for requesting to select the candidate Session Management Function (SMF) network element according to the first interface information of the at least one UPF network element.

In one possible design approach, the SMF network element may subscribe to the NRF network element for a notification of a change of state of a UPF network element controlled by the SMF network element. After the NRF network element receives the updated first interface information of the UPF network element controlled by the SMF network element, the NRF network element may send the updated first interface information of the UPF network element to the SMF network element. Then, the SMF network element may further verify whether the received first interface information of the UPF network element is incorrect, and determine whether to send the verified first interface information to the NRF network element, so as to update the first interface information of the UPF network element in the SMF network element configuration file stored in the NRF network element.

S503, the NRF network element sends the first response.

The first response carries first interface information of a candidate UPF network element in the at least one UPF network element, or an identifier of the candidate SMF network element.

In the process of selecting the UPF network element by the SMF network element, before performing the above S502, where the NRF network element receives the first request, the communication method further includes: and the SMF network element sends the first request to the NRF network element. Then, the NRF network element receives the first request, and uses the content carried by the first request as a query condition, queries candidate I-UPF network elements and/or candidate A-UPF network elements meeting the condition in a local cache of the NRF network element, and loads the queried candidate I-UPF network elements and/or candidate A-UPF network elements in a first response, and returns the response to the SMF network element, so that the SMF network element completes the UPF selection process. The content of the first request bearer and the content of the first response bearer are exemplified as follows.

Illustratively, the candidate UPF network elements may include candidate mid-user plane function I-UPF network elements, which are UPF network elements having a second interface with a radio access network RAN to which the terminal device is accessed. Therefore, in one possible design approach, the first request carries network information of a radio access network RAN to which the terminal device is accessing. The network information of the radio access network RAN accessed by the terminal equipment is used for inquiring the first interface information of the candidate I-UPF network element. Correspondingly, the first response carries the first interface information of the candidate I-UPF network element. And a second interface exists between the candidate I-UPF network element and the radio access network RAN.

Illustratively, the candidate UPF network elements may include candidate anchor user plane function a-UPF network elements, which are UPF network elements having a third interface with the data network DN to be accessed by the terminal device. In another possible embodiment, the first request therefore carries network information of the data network DN to be accessed by the terminal. The network information of the data network DN to be accessed by the terminal equipment is used for inquiring the first interface information of the candidate A-UPF network elements. Correspondingly, the first response carries the first interface information of the candidate a-UPF network element. And a third interface exists between the candidate A-UPF network element and the data network DN.

The two candidate UPF network element query methods can also be used in combination. For example, the query may be divided into two times, and in the first query and the second query, the first request may carry one of the following contents: network information of a radio access network RAN to which the terminal device is accessed, or network information of a data network DN to which the terminal device is to access. It is easy to understand that when the above two design methods are used in combination, in order to further improve the accuracy of the second query, the first request sent by the SMF network element for the second time may also carry the first interface information of the candidate I-UPF network element or the first interface information of the candidate a-UPF network element, which is carried by the first response returned during the first query. For another example, the SMF network element may also simultaneously carry, in the first request sent in the same query request, network information of a radio access network RAN to which the terminal device accesses and network information of a data network DN to which the terminal device accesses. Each of which is described in detail below.

Illustratively, the candidate UPF network elements may include a candidate intermediate user plane function I-UPF network element and a candidate anchor user plane function a-UPF network element, where the candidate I-UPF network element is a UPF network element having a second interface with a radio access network RAN to which the terminal device is accessed. Therefore, in a possible design method, the first request carries first interface information of the candidate I-UPF network elements, and the first interface information of the candidate I-UPF network elements is used to select, from at least one UPF network element, a UPF network element having a first interface with the candidate I-UPF network element as the candidate a-UPF network element. Correspondingly, the first response carries the identity of the candidate a-UPF network element.

Illustratively, the candidate UPF network elements may include a candidate intermediate user plane function I-UPF network element and a candidate anchor user plane function a-UPF network element, where the candidate a-UPF network element is a UPF network element having a third interface with the data network DN to be accessed by the terminal device. Therefore, in another possible design method, the first request carries first interface information of the candidate a-UPF network elements, and the first interface information of the candidate a-UPF network elements is used to select, from the at least one UPF network element, a UPF network element having a first interface with the candidate a-UPF network element as the candidate I-UPF network element. Correspondingly, the first response carries the identification of the candidate I-UPF network element.

Illustratively, the candidate UPF network elements may include candidate mid-user plane function I-UPF network elements and candidate anchor user plane function a-UPF network elements. Therefore, in yet another possible design method, the first request carries network information of a radio access network RAN to which the terminal device is connected and network information of a data network DN to which the terminal device is to access. Correspondingly, the first response carries the first interface information of the candidate I-UPF network element and the first interface information of the candidate A-UPF network element. The candidate I-UPF network element is a UPF network element with a second interface between the candidate I-UPF network element and a radio access network RAN accessed by the terminal equipment, and the candidate A-UPF network element is a UPF network element with a third interface between the candidate A-UPF network element and a data network DN to be accessed by the terminal equipment. Optionally, a first interface exists between the candidate I-UPF network element and the candidate a-UPF network element.

It should be noted that, in the process of selecting the UPF network element by the SMF network element, the NRF network element may query, in the local cache of the NRF network element, the content to be requested by the first request, with the content carried in the first request as a query condition, and return the query result to the SMF network element after carrying in the first response.

Illustratively, the NRF network element may query, according to the network information of the access network element accessed by the terminal device and/or the network information of the data network to be accessed by the terminal device, first interface information of the candidate I-UPF network element and/or the candidate a-UPF network element, which is locally stored in the NRF network element in the form of a configuration file, a spreadsheet, and the like, and load the first interface information in the first response and return the first response to the SMF network element.

In the process of selecting the SMF network element by the AMF network element, before performing the above S502, where the NRF network element receives the first request, the communication method further includes: and the AMF network element sends the first request to the NRF network element. Then, the NRF network element receives the first request, and uses the content carried by the first request as a query condition, queries a candidate I-SMF network element and/or a candidate A-SMF network element which meet the condition in a local cache of the NRF network element, and loads the queried candidate I-SMF network element and/or the candidate A-SMF network element in a first response, and returns the first response to the AMF network element, so that the AMF network element completes the SMF selection process. The content of the first request bearer and the content of the first response bearer are exemplified as follows.

Illustratively, the candidate SMF network elements may include candidate intermediate session management function I-SMF network elements, and among the UPF network elements controlled by the candidate I-SMF network elements, there is a UPF network element having a second interface with the radio access network RAN accessed by the terminal device. Therefore, in one possible design approach, the first request carries network information of a radio access network RAN to which the terminal device is accessing. Correspondingly, the first response carries the first interface information of the UPF network element controlled by the candidate I-SMF network element. And a second interface exists between the UPF network element controlled by the candidate I-SMF network element and the radio access network RAN.

Illustratively, the candidate SMF network elements may include candidate anchor point session management function a-SMF network elements, and among the UPF network elements controlled by the candidate a-SMF network elements, there is a UPF network element having a third interface with the data network DN to be accessed. In another possible embodiment, the first request therefore carries network information of the data network DN to be accessed by the terminal. Correspondingly, the first response carries the first interface information of the UPF network element controlled by the candidate A-SMF network element. And the UPF network element with a third interface between the UPF network element controlled by the candidate A-SMF network element and the data network DN to be accessed by the terminal equipment exists.

The two query methods of the candidate SMF network elements can also be used in combination. For example, the query may be divided into two times, and in the first query and the second query, the first request may carry one of the following contents: network information of a radio access network RAN to which the terminal device is accessed, or network information of a data network DN to which the terminal device is to access. It is easy to understand that, when the two design methods are used in combination, in order to further improve the accuracy of the second query, the first request sent by the AMF network element for the second time may also carry the first interface information of the candidate I-SMF network element control UPF network element carried by the first response returned during the first query, or the first interface information of the candidate a-SMF network element control UPF network element. For another example, the AMF network element may also simultaneously carry, in the first request sent in the same query request, network information of a radio access network RAN to which the terminal device accesses and network information of a data network DN to which the terminal device needs to access. Each of which is described in detail below.

Illustratively, the candidate SMF network elements may include a candidate intermediate session management function I-SMF network element and a candidate anchor session management function a-SMF network element, and among the UPF network elements controlled by the candidate I-SMF network elements, there is a UPF network element having a second interface with the radio access network RAN to which the terminal device is accessed. Therefore, in a possible design method, the first request carries first interface information of a candidate I-SMF network element-controlled UPF network element, and the first interface information of the candidate I-SMF network element-controlled UPF network element is used to select a candidate a-SMF network element from at least one SMF network element, so that the candidate a-SMF network element-controlled UPF network element and the candidate I-SMF network element-controlled UPF network element have a first interface. Correspondingly, the first response carries the identity of the candidate a-SMF network element.

Illustratively, the candidate SMF network elements may include a candidate intermediate user plane function I-SMF network element and a candidate anchor point session management function a-SMF network element, and among the UPF network elements controlled by the candidate a-SMF network elements, there is a UPF network element having a third interface with the data network DN to be accessed by the terminal device. Therefore, in another possible design method, the first request carries first interface information of a UPF network element controlled by the candidate a-SMF network element, and the first interface information of the UPF network element controlled by the candidate a-SMF network element is used to select a subsequent I-SMF network element from at least one SMF network element, so that a first interface exists between the UPF network element controlled by the candidate I-SMF network element and the UPF network element controlled by the candidate a-SMF network element, and the first response carries the first interface information of the UPF network element controlled by the candidate I-SMF network element.

Illustratively, the candidate SMF network elements may include candidate mid-user plane function I-SMF network elements and candidate anchor user plane function a-SMF network elements. Therefore, in yet another possible design method, the first request carries network information of a radio access network RAN to which the terminal device is connected and network information of a data network DN to which the terminal device is to access. Correspondingly, the first response carries the first interface information of the UPF network element controlled by the candidate I-SMF network element and the first interface information of the UPF network element controlled by the candidate A-SMF network element. And the UPF network elements controlled by the candidate A-SMF network elements have a UPF network element with a third interface with a data network DN to be accessed by the terminal equipment. Optionally, a first interface exists between the UPF network element controlled by the candidate I-SMF network element and the UPF network element controlled by the candidate a-SMF network element.

It should be noted that, in the process of selecting the SMF network element by the AMF network element, the NRF network element may query, in the local cache of the NRF network element, the content to be requested by the first request, with the content carried in the first request as a query condition, and return the query result to the AMF network element after carrying the query result in the first response.

Illustratively, the NRF network element may query, according to the network information of the access network element accessed by the terminal device and/or the network information of the data network to be accessed by the terminal device, first interface information of the candidate I-SMF network element and/or the UPF network element controlled by the candidate a-SMF network element, which are locally stored in the NRF network element in the form of a configuration file, a spreadsheet, and the like, and load the first interface information in the first response and return the first response to the AMF network element.

In the communication method provided by the present application, the NRF network element may receive and uniformly manage the first interface information of at least one UPF network element, and when the NRF network element receives the first request for selecting a UPF network element sent by the SMF network element, the NRF network element may send a first response to the SMF network element, the first response carrying the first interface information of the candidate UPF network element or the identifier of the candidate UPF network element, so that the SMF network element quickly selects the target UPF network element, or, when the NRF network element receives the first request for selecting a SMF network element sent by the AMF network element, the NRF network element may send a first response to the AMF network element, the first response carrying the first interface information of the UPF network element controlled by the candidate SMF network element or the identifier of the xuf network element controlled by the candidate SMF network element, so that the AMF network element quickly selects the target SMF network element, which may prevent the existence of the first interface between two or more UPF network elements in the state of the SMF network element, the first interface does not exist between the UPF network elements controlled by two or more than two SMF network elements selected by the AMF network element, so that the condition that normal session connection cannot be established is caused, the signaling waste, the resource waste and the time waste caused by selecting a proper target UPF network element and/or a target SMF network element through multiple interactions can be reduced, and the reliability and the efficiency of selecting the UPF network element and/or the SMF network element by the SMF network element can be improved.

It should be noted that the actions of the SMF network element, the AMF network element and the NRF network element involved in the communication method shown in any one of fig. 3 to 6 may be performed by the processor 201 in the communication apparatus 200 shown in fig. 2 calling the program code stored in the memory 203.

It is to be understood that, in the foregoing embodiments, the methods and/or steps implemented by the SMF network element, the AMF network element, and the NRF network element may also be implemented by a component (e.g., a chip or a circuit) disposed inside the foregoing network element, which is not limited in this embodiment of the present application.

The above-mentioned scheme provided by the embodiment of the present application is introduced mainly from the perspective of interaction between network elements. Correspondingly, the embodiment of the application also provides a communication device, and the communication device is used for realizing the various communication methods. The communication device may be an SMF network element, an AMF network element, or an NRF network element in the foregoing method embodiment, or a device including the foregoing SMF network element, AMF network element, or NRF network element, or a component that can be used in the foregoing SMF network element, AMF network element, or NRF network element. It is to be understood that the communication device comprises corresponding hardware structures and/or software modules for performing the respective functions in order to realize the above-mentioned functions. Those of skill in the art would readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiment of the present application, the communication apparatus may be divided into functional modules according to the method embodiments, for example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. It should be noted that, in the embodiment of the present application, the division of the module is schematic, and is only one logic function division, and there may be another division manner in actual implementation.

Fig. 7 is a schematic structural diagram of a communication apparatus 700 according to an embodiment of the present application, configured to execute functions performed by an SMF network element in the communication method shown in fig. 3. As shown in fig. 7, the communication apparatus 700 includes: a processing module 701 and a transceiver module 702.

The transceiver module 702 is configured to obtain the first control information and the second control information. The first control information comprises first interface information of at least one candidate I-UPF network element, and the second control information comprises first interface information of at least one candidate A-UPF network element.

A processing module 701, configured to determine, according to the first control information and the second control information, that a first interface exists between the first candidate I-UPF network element and the first candidate a-UPF network element. The first candidate I-UPF network element is a user plane network element in the at least one candidate I-UPF network element, and the first candidate A-UPF network element is a user plane network element in the at least one candidate A-UPF network element.

The processing module 701 is further configured to select a first candidate I-UPF network element and a first candidate a-UPF network element as target user plane network elements.

In one possible design, the first control information may include: the IP address set of the Internet protocol of the UPF network element which can be reached by the first interface of the candidate I-UPF network element; the second control information may include: an internet protocol, IP, address of a first interface of at least one candidate a-UPF network element. Correspondingly, the determining module 702 is further configured to determine that the internet protocol IP address of the first interface of the first candidate a-UPF network element exists in the internet protocol IP address set of the UPF network element where the first interface of the first candidate I-UPF network element is reachable.

In another possible design, the first control information may include: an internet protocol, IP, address of a first interface of at least one candidate I-UPF network element; the second control information may include: and the Internet protocol IP address set of the UPF network element which can be reached by the first interface of the at least one candidate A-UPF network element. Correspondingly, the processing module 701 is further configured to determine that the internet protocol IP address of the first interface of the first candidate I-UPF network element exists in the internet protocol IP address set of the UPF network element where the first interface of the first candidate a-UPF network element is reachable.

In one possible design, the first control information may include: an identification set of a data center DC with a reachable first interface of at least one candidate I-UPF network element; the second control information may include: an identification of the data center DC where the at least one candidate a-UPF network element is located. Correspondingly, the processing module 701 is further configured to determine that the identifier of the data center DC where the first candidate a-UPF network element is located exists in the identifier set of the data center DC where the first interface of the first candidate I-UPF network element is reachable.

In another possible design, the first control information may include: an identification of a data center DC where the at least one candidate I-UPF network element is located; the second control information may include: an identification set of data centers DC reachable by the first interface of the at least one candidate a-UPF network element. Correspondingly, the processing module 701 is further configured to determine that the identifier of the data center DC where the first candidate I-UPF network element is located exists in the identifier set of the data center DC where the first interface of the first candidate a-UPF network element is reachable.

In one possible design, the first control information may include: an identification set of a UPF network element which can be reached by a first interface of at least one candidate I-UPF network element; the second control information may include: an identification of at least one candidate a-UPF network element. Correspondingly, the processing module 701 is further configured to determine that the identifier of the first candidate a-UPF network element exists in the identifier set of the UPF network element where the first interface of the first candidate I-UPF network element is reachable.

In another possible design, the first control information may include: an identification of at least one candidate I-UPF network element; the second control information may include: and the identification set of the UPF network elements which can be reached by the first interface of the at least one candidate A-UPF network element. Correspondingly, the processing module 701 is further configured to determine that the identifier of the first candidate I-UPF network element exists in the identifier set of the UPF network element that the first interface of the first candidate a-UPF network element is reachable.

In one possible design, the first control information may include: a location set of UPF network elements that are reachable by a first interface of at least one candidate I-UPF network element; the second control information may include: a location of at least one candidate a-UPF network element. Correspondingly, the processing module 701 is further configured to determine that a location of the candidate first a-UPF network element exists in the location set of UPF network elements reachable by the first interface of the first candidate I-UPF network element.

In another possible design, the first control information may include: a location of at least one candidate I-UPF network element; the second control information may include: a set of locations of UPF network elements reachable by the first interface of the at least one candidate A-UPF network element. Correspondingly, the processing module 701 is further configured to determine that the location of the first candidate I-UPF network element exists in the location set of UPF network elements reachable by the first interface of the first candidate a-UPF network element.

In one possible design, the transceiver module 702 is further configured to the SMF network element obtain the first interface information of the at least one candidate I-UPF network element from the at least one candidate I-UPF network element or the network repository function NRF network element, and obtain the first interface information of the at least one candidate a-UPF network element from the at least one candidate a-UPF network element or the network repository function NRF network element.

Exemplarily, the at least one candidate I-UPF network element may be a UPF network element having a second interface with a radio access network RAN to which the terminal device is accessed; the at least one candidate a-UPF network element may be a UPF network element having a third interface with the data network DN to be accessed by the terminal device.

The communication apparatus 700 shown in fig. 7 may also be used to perform the functions performed by the AMF network element in the communication method shown in fig. 4. As shown in fig. 7, the transceiver module 702 is configured to obtain first interface information of a user plane function UPF network element controlled by at least one candidate intermediate session management function I-SMF network element and first interface information of a user plane function UPF network element controlled by at least one candidate anchor session management function a-SMF network element.

A processing module 701, configured to determine, according to the first interface information of the UPF network element controlled by the at least one candidate I-SMF network element and the first interface information of the UPF network element controlled by the at least one candidate a-SMF network element, that a first interface exists between the UPF network element controlled by the first candidate I-SMF network element in the at least one candidate I-SMF network element and the UPF network element controlled by the first candidate a-SMF network element in the at least one candidate a-SMF network element.

A processing module 701, configured to select a first candidate I-SMF network element and a first candidate a-SMF network element as a target SMF network element.

In one possible design, the third control information may include: the IP address set of the Internet protocol of the UPF network element which is reachable by the first interface of the UPF network element controlled by the at least one candidate I-SMF network element; the fourth control information may include: an internet protocol, IP, address of a first interface of a UPF network element controlled by the at least one candidate a-SMF network element. Correspondingly, the processing module 701 is further configured to determine that the internet protocol IP address of the first interface of the UPF network element controlled by the first candidate a-SMF network element exists in the internet protocol IP address set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate I-SMF network element.

In another possible design, the third control information may include: an Internet Protocol (IP) address of a first interface of a UPF network element controlled by at least one candidate I-SMF network element; the fourth control information may include: and the IP address set of the Internet protocol of the UPF network element which can be reached by the first interface of the UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, the processing module 701 is further configured to determine that the internet protocol IP address of the first interface of the UPF network element controlled by the first candidate I-SMF network element exists in the internet protocol IP address set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate a-SMF network element.

In one possible design, the third control information may include: the identification set of the data center DC with the reachable first interface of the UPF network element controlled by the at least one candidate I-SMF network element; the fourth control information may include: an identification of a data center DC where the UPF network element controlled by the at least one candidate a-SMF network element is located. Correspondingly, the processing module 701 is further configured to determine that an identifier of the data center DC where the UPF network element controlled by the first candidate a-SMF network element is located exists in the identifier set of the data center DC where the first interface of the UPF network element controlled by the first candidate I-SMF network element is reachable.

In another possible design, the third control information may include: an identifier of a data center DC where a UPF network element controlled by at least one candidate I-SMF network element is located; the fourth control information may include: and the identification set of the data center DC which is reachable by the first interface of the UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, the processing module 701 is further configured to determine that an identifier of the data center DC where the UPF network element controlled by the first candidate I-SMF network element is located exists in the identifier set of the data center DC where the first interface of the UPF network element controlled by the first candidate a-SMF network element is reachable.

In one possible design, the third control information may include: the identification set of the UPF network element which is controlled by at least one candidate I-SMF network element and can reach the first interface of the UPF network element; the fourth control information may include: an identification of a UPF network element controlled by at least one candidate A-SMF network element. Correspondingly, the processing module 701 is further configured to determine that the identifier of the UPF network element controlled by the first candidate a-SMF network element exists in the identifier set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate I-SMF network element.

In another possible design, the third control information may include: an identifier of a UPF network element controlled by at least one candidate I-SMF network element; the fourth control information may include: and the identifier set of the UPF network element which is reachable by the first interface of the UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, the processing module 701 is further configured to determine that the identifier of the UPF network element controlled by the first candidate I-SMF network element exists in the identifier set of the UPF network element reachable by the first interface of the UPF network element controlled by the first candidate a-SMF network element.

In one possible design, the third control information may include: the position set of the UPF network element which is controlled by at least one candidate I-SMF network element and can be reached by the first interface of the UPF network element; the fourth control information may include: a location of a UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, the processing module 701 is further configured to determine that the location of the UPF network element controlled by the first candidate a-SMF network element exists in the location set of UPF network elements reachable by the first interface of the UPF network element controlled by the first candidate I-SMF network element.

In another possible design, the third control information may include: a location of a UPF network element controlled by at least one candidate I-SMF network element; the fourth control information may include: and the position set of the UPF network element which is reachable by the first interface of the UPF network element controlled by the at least one candidate A-SMF network element. Correspondingly, the processing module 701 is further configured to determine that the location of the UPF network element controlled by the first candidate I-SMF network element exists in the location set of UPF network elements reachable by the first interface of the UPF network element controlled by the first candidate a-SMF network element.

In one possible design, the transceiver module 702 is further configured to obtain the first interface information of the UPF network element controlled by the at least one candidate I-SMF network element from the network repository function NRF network element or the at least one candidate I-SMF network element, and obtain the first interface information of the UPF network element controlled by the at least one candidate a-SMF network element from the network repository function NRF network element or the at least one candidate a-SMF network element.

Illustratively, the at least one candidate I-SMF network element may be: the SMF network element of the UPF network element with a second interface between the UPF network element and a radio access network RAN accessed by the terminal equipment exists in the controlled UPF network element; the at least one candidate a-SMF network element may be: and the SMF network element of the UPF network element with a third interface between the controlled UPF network element and the data network DN to be accessed by the terminal equipment exists in the controlled UPF network element.

It should be noted that the communication apparatus 700 may be an SMF network element in the communication method shown in fig. 3, or a chip system set in the SMF network element; alternatively, the communication apparatus 700 may also be an AMF network element in the communication method shown in fig. 4 or a chip system set in the AMF network element. The technical effects of the communication apparatus 700 can be referred to in the description related to the technical effects of the method embodiments shown in fig. 3 or fig. 4, and are not described herein again.

The communication apparatus 700 shown in fig. 7 may also be used to perform the functions performed by the NRF network element in the communication methods shown in fig. 5 and 6. The transceiver module 702 is configured to receive first interface information of at least one user plane function UPF network element. The first interface information may include an identifier of a reachable UPF network element of each UPF network element in the at least one UPF network element. The processing module 701 is configured to store the first interface information received by the transceiver module 702. The transceiver module 702 is further configured to receive a first request. The first request is used for acquiring first interface information of a candidate UPF network element in at least one UPF network element, or the first request is used for requesting to select the candidate UPF network element from the at least one UPF network element, or the first request is used for requesting to select the candidate Session Management Function (SMF) network element according to the first interface information of the at least one UPF network element. The transceiver module 702 is further configured to transmit a first response. The first response carries first interface information of a candidate UPF network element in the at least one UPF network element, or an identifier of the candidate SMF network element.

In a possible design, the transceiver module 702 is further configured to receive the first interface information sent by the at least one UPF network element, and/or the transceiver module 702 is further configured to receive the first interface information of the at least one UPF network element sent by the operation, administration and maintenance OAM equipment, and/or the transceiver module 702 is further configured to receive the first interface information of the UPF network element controlled by the at least one SMF network element sent by the at least one SMF network element.

Illustratively, the candidate UPF network elements may comprise candidate mid-user plane function I-UPF network elements. In one possible design, the first request carries network information of a radio access network RAN to which the terminal device is accessing. Correspondingly, the first response carries the first interface information of the candidate I-UPF network element, and a second interface exists between the candidate I-UPF network element and the radio access network RAN.

Illustratively, the candidate UPF network elements may comprise candidate anchor user plane function a-UPF network elements. In another possible embodiment, the first request carries network information of the data network DN to be accessed by the terminal. Correspondingly, the first response carries the first interface information of the candidate A-UPF network element, and a third interface exists between the candidate A-UPF network element and the data network DN.

Illustratively, the candidate UPF network elements may include a candidate intermediate user plane function I-UPF network element and a candidate anchor user plane function a-UPF network element, and the candidate I-UPF network element may be a UPF network element having a second interface with a radio access network RAN to which the terminal device is accessed. In one possible design, the first request carries first interface information of the candidate I-UPF network elements, and the first interface information of the candidate I-UPF network elements is used for selecting a UPF network element having a first interface with the candidate I-UPF network element from at least one UPF network element as a candidate a-UPF network element. Correspondingly, the first response carries the identity of the candidate a-UPF network element.

The candidate UPF network elements may illustratively include candidate mid-user plane function I-UPF network elements and candidate anchor user plane function a-UPF network elements, which may be UPF network elements having a third interface with the data network DN to be accessed by the terminal device. In another possible design, the first request carries first interface information of the candidate a-UPF network elements, and the first interface information of the candidate a-UPF network elements is used to select, from the at least one UPF network element, a UPF network element having a first interface with the candidate a-UPF network element as the candidate I-UPF network element. Correspondingly, the first response carries the identification of the candidate I-UPF network element.

Illustratively, the candidate UPF network elements may include candidate mid-user plane function I-UPF network elements and candidate anchor user plane function a-UPF network elements. In a further possible design, the first request carries network information of a radio access network RAN to which the terminal device is connected and network information of a data network DN to which the terminal device is to access. Correspondingly, the first response carries the first interface information of the candidate I-UPF network element and the first interface information of the candidate a-UPF network element, the candidate I-UPF network element may be a UPF network element having a second interface with a radio access network RAN to which the terminal device is accessed, and the candidate a-UPF network element may be a UPF network element having a third interface with a data network DN to which the terminal device is accessed.

Optionally, a first interface exists between the candidate I-UPF network element and the candidate a-UPF network element.

Illustratively, the candidate SMF network elements may comprise candidate mid-session management function I-SMF network elements. In one possible design, the first request carries network information of a radio access network RAN to which the terminal device is accessing. Correspondingly, the first response carries the first interface information of the UPF network element controlled by the candidate I-SMF network element, and a second interface exists between the UPF network element controlled by the candidate I-SMF network element and the radio access network RAN.

Illustratively, the candidate SMF network elements may comprise candidate anchor session management function a-SMF network elements. In another possible embodiment, the first request carries network information of the data network DN to be accessed by the terminal. Correspondingly, the first response carries the first interface information of the UPF network element controlled by the candidate A-SMF network element, and a third interface exists between the UPF network element controlled by the candidate A-SMF network element and the data network DN to be accessed by the terminal equipment.

Illustratively, the candidate SMF network elements may include a candidate intermediate session management function I-SMF network element and a candidate anchor session management function a-SMF network element, and among the UPF network elements controlled by the candidate I-SMF network elements, there is a UPF network element having a second interface with the radio access network RAN to which the terminal device is accessed. In one possible design, the first request carries first interface information of a UPF network element controlled by a candidate I-SMF network element, and the first interface information of the UPF network element controlled by the candidate I-SMF network element is used to select a first UPF network element having a first interface with the UPF network element controlled by the candidate I-SMF network element from at least one UPF network element, and select a candidate a-SMF network element from the SMF network elements controlling the first UPF network element. Correspondingly, the first response carries the identity of the candidate a-SMF network element.

Illustratively, the candidate SMF network elements may include a candidate intermediate user plane function I-SMF network element and a candidate anchor point session management function a-SMF network element, and among the UPF network elements controlled by the candidate a-SMF network elements, there is a UPF network element having a third interface with the data network DN to be accessed by the terminal device. In another possible design, the first request carries first interface information of the UPF network elements controlled by the candidate a-SMF network elements, and the first interface information of the UPF network elements controlled by the candidate a-SMF network elements is used to select a second UPF network element having a first interface with the UPF network elements controlled by the candidate a-SMF network elements from the at least one UPF network element, and select the candidate I-SMF network element from the SMF network elements controlling the second UPF network element. Correspondingly, the first response carries the first interface information of the UPF network element controlled by the candidate I-SMF network element.

Illustratively, the candidate SMF network elements may include candidate mid-user plane function I-SMF network elements and candidate anchor user plane function a-SMF network elements. In a further possible design, the first request carries network information of a radio access network RAN to which the terminal device is connected and network information of a data network DN to which the terminal device is to access. Correspondingly, the first response carries the first interface information of the UPF network element controlled by the candidate I-SMF network element and the first interface information of the UPF network element controlled by the candidate A-SMF network element, a UPF network element with a second interface between the UPF network element controlled by the candidate I-SMF network element and a radio access network RAN accessed by the terminal equipment exists in the UPF network element controlled by the candidate I-SMF network element, and a UPF network element with a third interface between the UPF network element controlled by the candidate A-SMF network element and a data network DN to be accessed by the terminal equipment exists in the UPF network element controlled by the candidate A-SMF.

Optionally, a first interface exists between the UPF network element controlled by the candidate I-SMF network element and the UPF network element controlled by the candidate a-SMF network element.

It should be noted that the transceiver module 702 may also be configured as a receiving module and a sending module, respectively, which is not limited in this embodiment of the application.

Further, the communication apparatus 700 may be an NRF network element in the communication methods shown in fig. 5 and 6 or a chip system provided in the NRF network element. The technical effects of the communication apparatus 700 can be described with reference to the technical effects of the method embodiments shown in fig. 5 and fig. 6, and are not described herein again.

The embodiment of the application provides a communication system. The communication system comprises a plurality of UPF network elements, one or more SMF network elements, AMF network elements and NRF network elements.

Wherein the SMF network element is operable to perform the communication method shown in fig. 3; the AMF network element may be configured to perform the communication method shown in fig. 4; the NRF network element may be configured to perform the communication methods of fig. 5 and 6.

In a possible design, the communication system may further include other devices or network elements interacting with the SMF network element in the communication method shown in fig. 3, such as a UPF network element, which may be configured to perform the functions performed by the I-UPF network element or the a-UPF network element in the communication method shown in fig. 3.

In a possible design, the communication system may further include other devices or network elements interacting with the AMF network element in the communication method shown in fig. 4, such as an SMF network element, and the SMF network element may be configured to perform the functions performed by the I-SMF network element or the a-SMF network element in the communication method shown in fig. 4.

In a possible design, the communication system may further include other devices or network elements, such as an SMF network element or an AMF network element, interacting with the NRF network element in the communication methods shown in fig. 5 and 6, where the SMF network element is operable to perform the functions performed by the SMF network element in the communication methods shown in fig. 5 and 6, and the AMF network element is operable to perform the functions performed by the AMF network element in the communication methods shown in fig. 5 and 6.

The present application provides a computer-readable storage medium, which stores instructions that, when executed on a computer, cause the computer to perform the communication method described in the above method embodiment.

Embodiments of the present application provide a computer program product containing instructions that, when executed on a computer, enable the computer to perform the communication method described in the above method embodiments.

It should be understood that the processor in the embodiments of the present application may be a Central Processing Unit (CPU), and the processor may also be other general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It will also be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile 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. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of Random Access Memory (RAM) are available, such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct bus RAM (DR RAM).

The above embodiments may be implemented in whole or in part by software, hardware (e.g., circuitry), firmware, or any combination thereof. When implemented in software, the above-described embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product comprises one or more computer instructions or computer programs. The procedures or functions according to the embodiments of the present application are wholly or partially generated when the computer instructions or the computer program are loaded or executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains one or more collections of available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium may be a solid state disk.

It should be understood that the term "and/or" herein is merely one type of association relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. In addition, the "/" in this document generally indicates that the former and latter associated objects are in an "or" relationship, but may also indicate an "and/or" relationship, which may be understood with particular reference to the former and latter text.

In the present application, "at least one" means one or more, "a plurality" means two or more. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple.

It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or session connection may be through some interfaces, indirect coupling or session connection of devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the 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 conceive of the changes or substitutions within the technical scope of the present application, and shall 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 communication method, characterized in that the communication method comprises:

a session management network element acquires first control information and second control information; wherein the first control information comprises first interface information of at least one candidate mid-user plane network element, and the second control information comprises first interface information of at least one candidate anchor user plane network element;

the session management network element determines that a first interface exists between a first candidate intermediate user plane network element and a first candidate anchor user plane network element according to the first control information and the second control information; the first candidate intermediate user plane network element is a user plane network element in the at least one candidate intermediate user plane network element, and the first candidate anchor user plane network element is a user plane network element in the at least one candidate anchor user plane network element;

and the session management network element selects the first candidate intermediate user plane network element and the first candidate anchor user plane network element as target user plane network elements.

2. The communication method according to claim 1, wherein the first control information includes: a set of internet protocol addresses of user plane network elements reachable by the first interface of the at least one candidate intermediate user plane network element; the second control information includes: an internet protocol address of a first interface of the at least one candidate anchor user plane network element;

the determining, by the session management network element according to the first control information and the second control information, that a first interface exists between a first candidate intermediate user plane network element and a first candidate anchor user plane network element includes:

the session management network element determines that the internet protocol address of the first interface of the first candidate anchor user plane network element exists in the internet protocol address set of the user plane network element where the first interface of the first candidate intermediate user plane network element can reach.

3. The communication method according to claim 1, wherein the first control information includes: an internet protocol address of a first interface of the at least one candidate mid-user plane network element; the second control information includes: a set of internet protocol addresses of user plane network elements reachable by the first interface of the at least one candidate anchor user plane network element;

the session management network element determines that the internet protocol address of the first interface of the first candidate intermediate user plane network element exists in the internet protocol address set of the user plane network element which can be reached by the first interface of the first candidate anchor user plane network element.

4. The communication method according to any of claims 1 to 3, wherein the obtaining, by the session management network element, the first control information and the second control information comprises:

the session management network element acquires the first control information from the at least one candidate intermediate user plane network element or network storage network element;

and the session management network element acquires the second control information from the at least one candidate anchor user plane network element or network storage network element.

5. The communication method according to any of claims 1 to 4, wherein the at least one candidate intermediate user plane network element is: a user plane network element with a second interface exists between the user plane network element and an access network element accessed by the terminal equipment; the at least one candidate anchor user plane network element is: and the user plane network element has a third interface with the data network to be accessed by the terminal equipment.

6. A communication method, characterized in that the communication method comprises:

the access management network element acquires third control information and fourth control information; wherein the third control information comprises first interface information of a user plane network element controlled by at least one candidate intermediate session management network element, and the fourth control information comprises first interface information of a user plane network element controlled by at least one candidate anchor session management network element;

the access management network element determines that a first interface exists between a user plane network element controlled by the first candidate intermediate session management network element and a user plane network element controlled by the first candidate anchor session management network element according to the third control information and the fourth control information; wherein the first candidate intermediate session management network element is a session management network element of the at least one candidate intermediate session management network element, and the first candidate anchor session management network element is a session management network element of the at least one candidate anchor session management network element;

and the access management network element selects the first candidate intermediate session management network element and the first candidate anchor point session management network element as a target session management network element.

7. The communication method according to claim 6, wherein the third control information comprises: a set of internet protocol addresses of user plane network elements reachable by a first interface of the user plane network element controlled by the at least one candidate mid-session management network element; the fourth control information includes: an internet protocol address of a first interface of a user plane network element controlled by the at least one candidate anchor session management network element;

the determining, by the access management network element according to the third control information and the fourth control information, that a first interface exists between a user plane network element controlled by the first candidate intermediate session management network element and a user plane network element controlled by the first candidate anchor session management network element includes:

the access management network element determines that the internet protocol address of the first interface of the user plane network element controlled by the first candidate anchor session management network element exists in the internet protocol address set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate intermediate session management network element.

8. The communication method according to claim 6, wherein the third control information comprises: an internet protocol address of a first interface of a user plane network element controlled by the at least one candidate mid-session management network element; the fourth control information includes: the internet protocol address set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element;

the access management network element determines that the internet protocol address of the first interface of the user plane network element controlled by the first candidate intermediate session management network element exists in the internet protocol address set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the first candidate anchor session management network element.

9. The communication method according to any of claims 6 to 8, wherein the obtaining, by the access management network element, the third control information and the fourth control information comprises:

the access management network element obtains the third control information from a network storage network element or the at least one candidate intermediate session management network element;

the access management network element obtains the fourth control information from a network storage network element or the at least one candidate anchor session management network element.

10. The communication method according to any of claims 6 to 9, wherein the at least one candidate mid-session management network element is: a session management network element of the user plane network element with a second interface exists between the controlled user plane network element and an access network element accessed by the terminal equipment; the at least one candidate anchor session management network element is: and a session management network element of the user plane network element with a third interface exists between the controlled user plane network element and the data network to be accessed by the terminal equipment.

11. A communication method, characterized in that the communication method comprises:

a network storage network element receives and stores first interface information of at least one user plane network element; wherein the first interface information includes an identifier of a user plane network element reachable by a user plane network element in the at least one user plane network element;

the network storage network element receives a first request; the first request is used for acquiring first interface information of a candidate user plane network element in the at least one user plane network element, or the first request is used for requesting to select a candidate user plane network element from the at least one user plane network element, or the first request is used for requesting to select a candidate session management network element according to the first interface information of the at least one user plane network element;

the network storage network element sends a first response; wherein the first response carries first interface information of a candidate user plane network element in the at least one user plane network element, or an identifier of the candidate session management network element.

12. The communication method according to claim 11, wherein the network storage network element receives the first interface information of at least one user plane network element, and comprises at least one of the following:

the network storage network element receives and stores the first interface information sent by the at least one user plane network element;

the network storage network element receives and stores the first interface information of the at least one user plane network element sent by the operation management maintenance equipment;

and the network storage network element receives and stores the first interface information of the user plane network element controlled by the at least one session management network element, which is sent by the at least one session management network element.

13. The communications method according to claim 11 or 12, characterized in that the candidate user plane network elements comprise candidate intermediate user plane network elements; the first request carries network information of an access network element accessed by the terminal equipment, the first response carries first interface information of the candidate intermediate user plane network element, and a second interface exists between the candidate intermediate user plane network element and the access network element.

14. The communication method according to claim 11 or 12, wherein the candidate user plane network elements comprise candidate anchor user plane function anchor user plane network elements; the first request carries network information of a data network to be accessed by the terminal equipment, the first response carries first interface information of the candidate anchor point user plane network element, and a third interface exists between the candidate anchor point user plane network element and the data network.

15. A communication apparatus, characterized in that the communication apparatus comprises: the device comprises a processing module and a transmitting-receiving module; wherein the content of the first and second substances,

the transceiver module is used for acquiring first control information and second control information; wherein the first control information comprises first interface information of at least one candidate mid-user plane network element, and the second control information comprises first interface information of at least one candidate anchor user plane network element;

the processing module is configured to determine, according to the first control information and the second control information, that a first interface exists between a first candidate intermediate user plane network element and a first candidate anchor user plane network element; the first candidate intermediate user plane network element is a user plane network element in the at least one candidate intermediate user plane network element, and the first candidate anchor user plane network element is a user plane network element in the at least one candidate anchor user plane network element;

the processing module is further configured to select the first candidate intermediate user plane network element and the first candidate anchor user plane network element as target user plane network elements.

16. The communications apparatus of claim 15, wherein the first control information comprises: a set of internet protocol addresses of user plane network elements reachable by the first interface of the at least one candidate intermediate user plane network element; the second control information includes: an internet protocol address of a first interface of the at least one candidate anchor user plane network element;

the processing module is further configured to determine that the internet protocol address of the first interface of the first candidate anchor user plane network element exists in the internet protocol address set of the user plane network element reachable by the first interface of the first candidate intermediate user plane network element.

17. The communications apparatus of claim 15, wherein the first control information comprises: an internet protocol address of a first interface of the at least one candidate mid-user plane network element; the second control information includes: a set of internet protocol addresses of user plane network elements reachable by the first interface of the at least one candidate anchor user plane network element;

the processing module is further configured to determine that an internet protocol address of the first interface of the first candidate intermediate user plane network element exists in an internet protocol address set of a user plane network element reachable by the first interface of the first candidate anchor user plane network element.

18. The communication device according to any of claims 15-17,

the transceiver module is further configured to acquire the first control information from the at least one candidate intermediate user plane network element or network storage network element;

the transceiver module is further configured to acquire the second control information from the at least one candidate anchor user plane network element or network storage network element.

19. The communications apparatus according to any of claims 15-18, wherein the at least one candidate mid-user plane network element is: a user plane network element with a second interface exists between the user plane network element and an access network element accessed by the terminal equipment; the at least one candidate anchor user plane network element is: and the user plane network element has a third interface with the data network to be accessed by the terminal equipment.

20. A communication apparatus, characterized in that the communication apparatus comprises: the device comprises a processing module and a transmitting-receiving module; wherein the content of the first and second substances,

the transceiver module is used for acquiring third control information and fourth control information; wherein the third control information comprises first interface information of a user plane network element controlled by at least one candidate intermediate session management network element, and the fourth control information comprises first interface information of a user plane network element controlled by at least one candidate anchor session management network element;

the processing module is configured to determine, according to the third control information and the fourth control information, that a first interface exists between a user plane network element controlled by the first candidate intermediate session management network element and a user plane network element controlled by the first candidate anchor session management network element; wherein the first candidate intermediate session management network element is a session management network element of the at least one candidate intermediate session management network element, and the first candidate anchor session management network element is a session management network element of the at least one candidate anchor session management network element;

the processing module is further configured to select one of the first candidate intermediate session management network element and the first candidate anchor session management network element as a target session management network element.

21. The communications apparatus of claim 20, wherein the third control information comprises: a set of internet protocol addresses of user plane network elements reachable by a first interface of the user plane network element controlled by the at least one candidate mid-session management network element; the fourth control information includes: an internet protocol address of a first interface of a user plane network element controlled by the at least one candidate anchor session management network element;

the processing module is further configured to determine that an internet protocol address of the first interface of the user plane network element controlled by the first candidate anchor session management network element exists in an internet protocol address set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate intermediate session management network element.

22. The communications apparatus of claim 20, wherein the third control information comprises: an internet protocol address of a first interface of a user plane network element controlled by the at least one candidate mid-session management network element; the fourth control information includes: the internet protocol address set of the user plane network element which is reachable by the first interface of the user plane network element controlled by the at least one candidate anchor point session management network element;

the processing module is further configured to determine that an internet protocol address of the first interface of the user plane network element controlled by the first candidate intermediate session management network element exists in an internet protocol address set of the user plane network element reachable by the first interface of the user plane network element controlled by the first candidate anchor session management network element.

23. The communication device according to any of claims 20-22,

the transceiver module is further configured to obtain the third control information from a network storage network element or the at least one candidate mid-session management network element;

the transceiver module is further configured to acquire the fourth control information from a network storage network element or the at least one candidate anchor point session management network element.

24. The communications device according to any of claims 20-23, wherein the at least one candidate mid-session management network element is: a session management network element of the user plane network element with a second interface exists between the controlled user plane network element and an access network element accessed by the terminal equipment; the at least one candidate anchor session management network element is: and a session management network element of the user plane network element with a third interface exists between the controlled user plane network element and the data network to be accessed by the terminal equipment.

25. A communication apparatus, characterized in that the communication apparatus comprises: the device comprises a processing module and a transmitting-receiving module; wherein the content of the first and second substances,

the transceiver module is configured to receive first interface information of at least one user plane network element; wherein the first interface information includes an identifier of a user plane network element reachable by a user plane network element in the at least one user plane network element;

the processing module is used for storing the first interface information received by the transceiver module;

the transceiver module is further configured to receive a first request; the first request is used for acquiring first interface information of a candidate user plane network element in the at least one user plane network element, or the first request is used for requesting to select a candidate user plane network element from the at least one user plane network element, or the first request is used for requesting to select a candidate session management network element according to the first interface information of the at least one user plane network element;

the transceiver module is used for transmitting a first response; wherein the first response carries first interface information of a candidate user plane network element in the at least one user plane network element, or an identifier of the candidate session management network element.

26. The communication device of claim 25,

the transceiver module is further configured to receive first interface information sent by the at least one user plane network element;

the transceiver module is further configured to receive first interface information of the at least one user plane network element, which is sent by the operation management maintenance device;

the transceiver module is further configured to receive first interface information of a user plane network element controlled by at least one session management network element, where the first interface information is sent by the at least one session management network element.

27. The communications device according to claim 25 or 26, wherein the candidate user plane network elements comprise candidate intermediate user plane network elements; the first request carries network information of an access network element accessed by the terminal equipment, the first response carries first interface information of the candidate intermediate user plane network element, and a second interface exists between the candidate intermediate user plane network element and the access network element.

28. The communications device of claim 25 or 26, wherein the candidate user plane network elements comprise candidate anchor user plane function anchor user plane network elements; the first request carries network information of a data network to be accessed by the terminal equipment, the first response carries first interface information of the candidate anchor point user plane network element, and a third interface exists between the candidate anchor point user plane network element and the data network.