CN111770124B

CN111770124B - Method and device for selecting session management network element

Info

Publication number: CN111770124B
Application number: CN201910364111.3A
Authority: CN
Inventors: 宗在峰; 朱奋勤
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-04-02
Filing date: 2019-04-30
Publication date: 2022-01-11
Anticipated expiration: 2039-04-30
Also published as: CN111770124A

Abstract

The application provides a method and a device for selecting a session management network element, wherein a service communication agent network element can judge whether a session management network element meeting first parameter information exists, the first parameter information comprises position information and a data network name DNN of UE, and under the condition that the session management network element meeting the first parameter information does not exist, the service communication agent network element selects one or more first session management network elements supporting the DNN and sends a rejection message to a mobility management network element, and the rejection message comprises the information of the one or more first session management network elements, so that the mobility management network element can acquire the information of the one or more first session management network elements, and the selection of the session management network element in a home routing mode or an enhanced topology mode is supported.

Description

Method and device for selecting session management network element

The present application claims priority of chinese patent application filed on 2/4/2019 under the name "method and apparatus for selecting a session management network element" by the chinese patent office under application number 201910263105.9, the entire contents of which are incorporated herein by reference.

Technical Field

The present application relates to the field of communications, and more particularly, to a method and apparatus for selecting a session management network element.

Background

A proxy discovery mode (deleted discovery) is introduced into a service architecture in the 3GGP Release 16, that is, a network element (network function) does not perform a discovery function and performs service discovery by a Service Communication Proxy (SCP). However, for the following situation that two Session Management Functions (SMFs) need to be selected, such as a home routing mode, an enhanced topology of SMF and UPF in 5G network (ETSUN) mode between the SMF and a User Plane Function (UPF) introduced in the 5G network, the proxy discovery mode is no longer applicable.

Specifically, for example, if the session is in home routed mode, the AMF needs to select V-smf (vplmn smf) and H-smf (hplmn smf). In the home-rural routing mode, the AMF includes information of the selected H-SMF in a request message to send to the V-SMF, so that the V-SMF can send the request message to the H-SMF according to the H-SMF selected by the AMF. However, when the AMF operates in the proxy discovery mode, since the AMF does not select the SMF, the AMF cannot fill the H-SMF information into the request message, and thus how to select the H-SMF and how to send the H-SMF information to the V-SMF are problems to be solved.

Disclosure of Invention

In view of the above, the present application provides a method and an apparatus for selecting a session management network element, where a serving communication proxy network element supports selection of an SMF in a home routing mode or an enhanced topology mode by sending one or more first SMFs to a mobility management network element.

In a first aspect, a method for selecting a session management network element is provided, including: the serving communication agent network element receiving a first message from the mobility management network element; the service communication agent network element acquires first parameter information according to the first message, wherein the first message is used for requesting the service communication agent network element to select an SMF according to the first parameter information, and the first parameter information comprises the position information of User Equipment (UE) and a Data Network Name (DNN); the service communication agent network element determines whether the SMF meeting the first parameter information exists; and in the case that there is no SMF satisfying the first parameter information, the serving communication agent network element selects one or more first SMFs supporting the DNN, and sends a rejection message to the mobility management network element, where the rejection message includes information of the one or more first SMFs. Accordingly, the serving communication agent network element enables the mobility management network element to acquire information of the one or more first SMFs by transmitting the one or more first SMFs supporting the DNN to the mobility management network element, thereby performing a subsequent operation.

In one possible implementation, the method further includes: and under the condition that the SMF meeting the first parameter information exists, the service communication agent network element acquires a first request message according to the first message and sends the first request message to the SMF.

Optionally, the information of the first one or more first SMFs includes one or more of service area information of servers of the one or more first SMFs, identification information of the one or more first SMFs, and URIs of the one or more first SMFs.

In one possible implementation, the method further includes: the serving communication agent network element receiving a second message from the mobility management network element; the service communication agent network element acquires second parameter information according to the second message, wherein the second parameter information comprises the position information of the UE; the serving communication agent network element selects the second SMF based on the second parameter information; and the service communication agent network element acquires a second request message according to the second message and sends the second request message to the second SMF. Thus, the serving communication agent network element may receive the second message from the mobility management network element and obtain the second parameter information, thereby selecting the second SMF that satisfies the second parameter information.

In one possible implementation, the method further includes: and the service communication agent network element sends the information of the second SMF to the mobility management network element. Thus, the serving communication proxy network element may send information of the selected second SMF to the mobility management network element.

Optionally, the serving communication agent network element may receive a response message from the second SMF, and then send the response message to the mobility management network element, where a header or a message body of the response message carries information of the second SMF.

Optionally, the information of the second SMF includes one or more of service area information of a server of the second SMF, identification information of the second SMF, and a URI of the second SMF.

In one possible implementation manner, in a case where there is no SMF satisfying the first parameter information, the selecting, by the serving communication agent network element, one or more first SMFs supporting the DNN and sending a rejection message to the mobility management network element includes: the first parameter information further includes target network element type indication information, and if the target network element type indication information is used to indicate that the serving communication agent network element selects an SMF, the serving communication agent network element selects one or more first SMFs that support the DNN and sends information of the one or more first SMFs to the mobility management network element, in a case that it is determined that there is no SMF that satisfies the first parameter information. That is, the serving communication agent network element may select one or more first SMFs supporting the DNN based on the target network element type indication information and send a reject message to the mobility management network element.

In one possible implementation, the method further includes: the serving communication agent network element receives first indication information from the mobility management network element, where the first indication information is used to indicate: and the serving communication agent network element selects one or more first SMFs supporting the DNN under the condition that the serving communication agent network element determines that the SMFs meeting the first parameter information do not exist, and sends information of the one or more first SMFs to the mobility management network element. That is, the serving communication agent network element may select one or more first SMFs supporting the DNN based on the first indication information and send a reject message to the mobility management network element. Optionally, the first indication information is used to indicate that an H-SMF is selected, where the H-SMF is an SMF supporting DNN.

Optionally, the second request message includes information of the one or more first SMFs.

Optionally, the second SMF is a visited session management function V-SMF, and the first SMF is an H-SMF, wherein the first parameter information further includes an identifier HPLMN ID of a home public land mobile network, the first parameter information is used to discover the home session management function H-SMF, and the reject message includes information of one or more H-SMFs.

Optionally, in the absence of an SMF satisfying the first parameter information, the selecting, by the serving communication agent network element, one or more first SMFs supporting the DNN includes:

in the absence of an SMF satisfying the first parameter information, the serving communication agent network element selects one or more H-SMFs supporting the HPLMN ID and the DNN. Thus, if there are no SMFs that satisfy the location information, HPLMN ID and DNN of the UE at the same time, the serving communication agent network element selects one or more H-SMFs that support the HPLMN ID and the DNN.

Optionally, the second SMF is an intermediate session management function I-SMF.

In a second aspect, a method for selecting a session management network element is provided, including: a mobility management network element sends a first message to a serving communication agent network element, wherein the first message comprises first parameter information, the first message is used for requesting the serving communication agent network element to select an SMF (short message service) according to the first parameter information, a first request message is obtained according to the first request message, and the first request message is sent to the SMF, and the first parameter information comprises position information of User Equipment (UE) and a Data Network Name (DNN); and the mobility management network element receives a rejection message from the serving communication agent network element, wherein the rejection message comprises information of one or more first SMFs supporting the DNN selected by the serving communication agent. Accordingly, the mobility management network element may obtain information of the one or more first SMFs to perform subsequent operations.

In one possible implementation, the method further includes: the mobility management network element sends a second message to the serving communication agent network element, where the second message includes second parameter information and one or more third SMFs in the one or more first SMFs, the second parameter information is used to discover the second SMF, the second parameter information includes location information of the UE, and the one or more third SMFs are used to send to the second SMF. Therefore, the mobility management network element may send a second message to the serving communication agent network element, so that the serving communication agent network element obtains the second parameter information.

In one possible implementation, the method further includes: the mobility management network element receives information of the second SMF from the serving communication agent network element. Thus, the mobility management network element may obtain information of said second SMF.

Optionally, the mobility management network element receives a response message from the serving communication agent network element, where a header or a message body of the response message carries information of the second SMF.

In a possible implementation manner, the first parameter information further includes target network element type indication information, where the target network element type indication information is used to indicate that the serving communication agent network element selects an SMF.

In one possible implementation, the method further includes:

the mobility management network element sends first indication information to the serving communication agent network element, where the first indication information is used to indicate: and the serving communication agent network element selects one or more first SMFs supporting the DNN under the condition that the serving communication agent network element determines that the SMFs meeting the first parameter information do not exist, and sends the information of the one or more first SMFs to the mobility management network element.

Optionally, the second SMF is a visited session management function V-SMF, the one or more first SMFs are one or more H-SMFs, wherein the first parameter information further includes an identity HPLMN ID of a home public land mobile network, the first parameter information is used for discovering the home session management function H-SMF, and the reject message includes information of the one or more H-SMFs.

Optionally, the information of the one or more H-SMFs is the one or more H-SMFs supporting the HPLMN ID and the DNN selected by the serving communication proxy network element.

In a third aspect, a method for selecting a session management network element is provided, including: the serving communication agent network element receiving a first message from the mobility management network element; the service communication agent network element acquires first parameter information according to the first message, the first message is used for requesting the service communication agent network element to select an SMF according to the first parameter information, acquires a first request message according to the first message, and sends the first request message to the SMF, and the first parameter information comprises position information and a data network name DNN of User Equipment (UE); the service communication agent network element determines whether SMF meeting the first parameter information exists; and under the condition that the SMF meeting the first parameter information does not exist, the service communication agent network element sends a rejection message to the mobility management network element, wherein the rejection message is used for indicating that the SMF meeting the first parameter information does not exist. Therefore, the serving communication agent network element sends the rejection message to the mobility management network element, so that the mobility management network element can know that there is no SMF that satisfies the first parameter information, thereby performing subsequent operations.

In one possible implementation, the method further includes:

the serving communication agent network element receiving second parameter information from the mobility management network element, the second parameter information comprising the DNN; and the serving communication agent network element selects one or more first SMFs supporting the second parameter information, and sends a first response message to a mobility management network element, wherein the first response message comprises the information of the one or more first SMFs. Therefore, the serving communication agent network element enables the mobility management network element to acquire information of the first SMF by transmitting the one or more first SMFs supporting the DNN to the mobility management network element, thereby performing a subsequent operation. In this way, the mobility management network element may send information of the first SMF to the second SMF. For example, in the enhanced topology mode, the mobility management network element may send information of the I-SMF to the SMF.

Optionally, the information of the first one or more first SMFs includes at least one of service area information of servers of the one or more first SMFs, identification information of the one or more first SMFs, and URIs of the one or more first SMFs.

In one possible implementation, the method further includes:

the service communication agent network element receives a second message from the mobility management network element;

the service communication agent network element acquires third parameter information according to the second message, wherein the third parameter information comprises the position information of the UE;

the service communication agent network element selects the second SMF according to the third parameter information;

and the service communication agent network element acquires a second request message according to the second message and sends the second request message to the second SMF.

In one possible implementation, the method further includes:

and the service communication agent network element sends the information of the second SMF to the mobility management network element.

In one possible implementation manner, the selecting, by the serving communication agent network element, one or more first SMFs supporting the DNN, and sending a first response message to the mobility management network element includes:

the second parameter information further includes first indication information, where the first indication information is used to indicate that the serving communication agent network element selects one or more SMFs that support the DNN, and send the first response message to the mobility management network element.

the second parameter information further includes first target network element type indication information, and if the first target network element type indication information is used to indicate an SMF, the serving communication agent network element selects one or more first SMFs supporting the DNN, and sends the first response message to the mobility management network element.

the second parameter information further includes first indication information, and the first indication information is used for indicating: the serving communication agent network element selects one or more first SMFs supporting the DNN and sends the first response message to the mobility management network element.

In a possible implementation manner, the selecting, by the serving communication agent network element, the second SMF based on the third parameter information includes:

the third parameter information further includes second target network element type indication information, where the second target network element type indication information is used to indicate the intermediate SMF.

In a fourth aspect, a method for selecting a session management network element is provided, including: a mobility management network element sends a first message to a serving communication agent network element, wherein the first message comprises first parameter information, the first message is used for requesting the serving communication agent network element to select an SMF (short message service) according to the first parameter information, a first request message is obtained according to the first request message, and the first request message is sent to the SMF, and the first parameter information comprises position information of User Equipment (UE) and a Data Network Name (DNN); and the mobility management network element receives a rejection message from the serving communication agent network element, wherein the rejection message is used for indicating that no SMF meeting the first parameter information exists. Therefore, the mobility management network element can know that there is no SMF satisfying the first parameter information, thereby performing subsequent operations.

In one possible implementation, the method further includes: the mobility management network element sends second parameter information to the serving communication agent network element, where the second parameter information includes the DNN; the mobility management network element receives a first response message from the serving communication agent network element, where the first response message includes information of the one or more first SMFs.

In one possible implementation, the method further includes: and the mobility management network element sends a second message to the serving communication agent network element, where the second message includes third parameter information, the third parameter information includes location information of the UE, and the third parameter information is used to select a second SMF.

In one possible implementation, the method further includes: the mobility management network element receives information of the second SMF from the serving communication agent network element.

Optionally, the mobility management network element may receive a response message from the serving communication agent network element, where the response message is sent to the serving communication agent network element by the second SMF, and a header or a message body of the response message carries information of the second SMF.

Optionally, the second parameter information further includes first indication information, where the first indication information is used to indicate that the serving communication agent network element selects one or more SMFs that support the DNN, and send the first response message to the mobility management network element.

Optionally, the second parameter information further includes first target network element type indication information, where the first target network element type indication information is used to indicate that the serving communication agent network element selects an SMF.

Optionally, the second parameter information further includes second target network element type indication information, where the second target network element type indication information is used to indicate that the serving communication agent network element selects an intermediate SMF.

In a fifth aspect, a method for selecting a session management network element is provided, including: the serving communication agent network element receiving a first message from the mobility management network element; the service communication agent network element acquires first parameter information according to the first message, wherein the first message is used for requesting the service communication agent network element to discover the H-SMF according to the first parameter information, and the first parameter information comprises an identifier HPLMN ID and a data network name DNN of a home public land mobile network; and the serving communication agent network element selects one or more H-SMFs meeting the first parameter information, and sends a first response message to the mobility management network element, wherein the first response message comprises the information of the one or more H-SMFs. Therefore, in the home and rural routing mode, the serving communication agent network element enables the mobility management network element to acquire the information of the H-SMF by sending one or more H-SMFs supporting the HPLMN ID and DNN to the mobility management network element, so as to perform subsequent operations, for example, the mobility management network element may send the received information of the H-SMF to the V-SMF.

In one possible implementation, the method further includes:

the serving communication agent network element receiving a second message from the mobility management network element;

the service communication agent network element acquires second parameter information according to the second message, wherein the second parameter information comprises the position information of the UE;

the service communication agent network element selects the V-SMF according to the second parameter information;

and the service communication agent network element acquires a second request message according to the second message and sends the second request message to the V-SMF.

In one possible implementation, the method further includes:

and the service communication agent network element sends the information of the V-SMF to the mobility management network element.

Optionally, the serving communication agent network element may receive a response message from the V-SMF, and then send the response message to the mobility management network element, where a header or a message body of the response message carries information of the V-SMF.

Optionally, the information of the V-SMF includes one or more of service area information of a server of the V-SMF, identification information of the V-SMF, and a URI of the V-SMF.

In one possible implementation, the method further includes:

the serving communication agent network element receives first indication information from the mobility management network element, wherein the first parameter information further includes first indication information, and the first indication information is used for indicating the serving communication agent network element to reply a response message to the mobility management network element after finding the H-SMF.

Optionally, the selecting, by the serving communication agent network element, one or more H-SMFs that satisfy the first parameter information, and sending a first response message to the mobility management network element includes:

the first parameter information further includes first target network element type indication information, where the first target network element type indication information is used to indicate an H-SMF or an SMF, and then the serving communication agent network element selects one or more H-SMFs that support the HPLMN ID and the DNN, and sends the first response message to the mobility management network element.

Optionally, the selecting, by the serving communication agent network element, a V-SMF supporting location information of the UE based on the second parameter information includes:

the second parameter information further includes second target network element type indication information, where the second target network element type indication information is used to indicate the serving communication agent network element to select V-SMF.

In a sixth aspect, a method for selecting a session management network element is provided, including: a mobility management network element sends a first message to a service communication agent network element, wherein the first message comprises first parameter information, the first message is used for requesting the service communication agent network element to discover an H-SMF according to the first parameter information, and the first parameter information comprises an identifier HPLMN ID and a data network name DNN of a home public land mobile network; the mobility management network element receives a first response message from the serving communication agent network element, the first response message including information of the one or more H-SMFs. Therefore, in the home and rural routing mode, the mobility management element can acquire the information of the H-SMF to perform subsequent operations, for example, the mobility management element can send the received information of the H-SMF to the V-SMF.

In one possible implementation, the method further includes:

and the mobility management network element sends a second message to the serving communication agent network element, wherein the second message comprises second parameter information, the second parameter information is used for discovering the V-SMF, and the second parameter information comprises the position information of the UE.

In one possible implementation, the method further includes:

the mobility management network element receives information of the V-SMF from the serving communication agent network element.

Optionally, the mobility management network element may receive a response message from the serving communication agent network element, where the response message is sent by the V-SMF to the serving communication agent network element, and a header or a message body of the response message carries information of the V-SMF.

In one possible implementation, the method further includes:

the first parameter information further includes first indication information, where the first indication information is used to indicate that the serving communication agent network element replies a response message to the mobility management network element after discovering the H-SMF.

Optionally, the first parameter information further includes first target network element type indication information, where the first target network element type indication information is used to indicate that the serving communication agent network element selects H-SMF or SMF.

Optionally, the second parameter information further includes second target network element type indication information, where the second target network element type indication information is used to indicate that the serving communication agent network element selects V-SMF.

A seventh aspect provides a method for selecting a session management network element, including: the serving communication agent network element receiving a first message from the mobility management network element; the service communication agent network element acquires first parameter information according to the first message, wherein the first parameter information comprises position information of User Equipment (UE) and a Data Network Name (DNN); the service communication agent network element determines whether SMF meeting the first parameter information exists; and under the condition that the SMF meeting the first parameter information does not exist, the service communication agent network element selects one or more first SMFs according to the DNN and selects a second SMF according to the position information of the UE. Therefore, the serving communication proxy network element may determine itself whether the session needs to select two SMFs simultaneously, so that when the mobility management network element operates in the proxy discovery mode, it still supports creating a session including two SMFs, thereby not limiting the application scenarios in which the mobility management network element operates in the proxy discovery mode.

In one possible implementation, the method further includes:

the service communication agent network element generates a second request message according to the first message and the one or more first SMFs, wherein the second request message comprises information of one or more fourth SMFs in the one or more first SMFs;

and the service communication agent network element sends a second request message to the second SMF.

In one possible implementation, the method further includes:

the serving communication agent network element sends, to the mobility management network element, information of the fifth SMF and information of the second SMF, where the fifth SMF is an SMF selected by the second SMF among the one or more fourth SMFs.

Optionally, the information of the second SMF includes at least one of service area information of a server of the second SMF, identification information of the second SMF, and a URI of the second SMF; the information of the fifth SMF includes one or more of service area information of a server of the fifth SMF, identification information of the fifth SMF, and a URI of the fifth SMF.

Optionally, the information of the fifth SMF and the information of the second SMF are included in a header of the first response message or in a message body of the first response message.

In one possible implementation, the method further includes:

the service communication agent network element receives a first response message from the second SMF, wherein the first response message comprises URI information of the fifth SMF;

wherein the sending, by the serving communication agent network element, the information of the fifth SMF to the mobility management network element further includes:

the service communication agent network element acquires the information of the fifth SMF according to the URI information of the fifth SMF in the first response message;

and the service communication agent network element sends the information of the fifth SMF to the mobility management network element.

Optionally, the generating, by the serving communication agent network element, a second request message according to the first message and the one or more first SMFs, where the second request message includes information of one or more fourth SMFs in the one or more first SMFs, and further includes:

information of the one or more fourth SMFs is included in a header of the second request message or in a message body of the second request message.

Optionally, the first SMF is an SMF and the second SMF is an I-SMF;

alternatively, the first SMF is H-SMF and the second SMF is V-SMF.

In an eighth aspect, a method for selecting a session management network element is provided, including: a mobility management network element sends a first message to a service communication agent network element, wherein the first message comprises first parameter information, and the first parameter information comprises position information of User Equipment (UE) and a Data Network Name (DNN); and the mobility management network element receives the information of the fifth SMF and the information of the second SMF from the service communication agent network element. Therefore, the mobility management network element may obtain the two SMFs determined by the serving communication agent network element, so that when the mobility management network element operates in the agent discovery mode, the creation of a session including the two SMFs is still supported, and thus, the application scenario in which the mobility management network element operates in the agent discovery mode is not limited.

In a possible implementation manner, the receiving, by the mobility management network element, information of the fifth SMF and information of the second SMF from the serving communication agent network element includes:

the mobility management network element receives a first response message from the serving communication agent network element, wherein the information of the fifth SMF and the information of the second SMF are included in a header of the first response message or in a message body of the first response message.

Optionally, the first SMF is an SMF and the second SMF is an I-SMF; alternatively, the first SMF is H-SMF and the second SMF is V-SMF.

In a ninth aspect, a method for selecting a session management network element is provided, including: the serving communication agent network element receiving a first message from the mobility management network element; the service communication agent network element acquires first parameter information according to the first message, wherein the first message is used for requesting the service communication agent network element to discover the SMF according to the first parameter information, and the first parameter information comprises a data network name DNN; the serving communication agent network element selects one or more SMFs satisfying the first parameter information, and sends a first response message to the mobility management network element, where the first response message includes information of the one or more SMFs. Therefore, the serving communication agent network element enables the mobility management network element to acquire the information of the SMFs by sending one or more SMFs supporting the DNN to the mobility management network element, so as to perform subsequent operations, for example, the mobility management network element may determine whether it is necessary to select the intermediate session management network element I-SMF according to the received information of the SMFs.

In one possible implementation, the method further includes:

the service communication agent network element selects I-SMF according to the second parameter information;

and the service communication agent network element acquires a second request message according to the second message and sends the second request message to the I-SMF.

In one possible implementation, the method further includes:

and the service communication agent network element sends the information of the I-SMF to the mobility management network element.

Optionally, the serving communication agent network element may receive a response message from the I-SMF, and then send the response message to the mobility management network element, where a header or a message body of the response message carries information of the I-SMF.

Optionally, the information of the I-SMF includes one or more of service area information of a server of the I-SMF, identification information of the I-SMF, and a URI of the I-SMF.

In one possible implementation, the method further includes:

the serving communication agent network element receives first indication information from the mobility management network element, where the first parameter information further includes the first indication information, and the first indication information is used to indicate that the serving communication agent network element replies a response message to the mobility management network element after discovering the SMF.

Optionally, the selecting, by the serving communication agent network element, one or more SMFs satisfying the first parameter information, and sending a first response message to the mobility management network element includes:

the first parameter information further includes first target network element type indication information, where the first target network element type indication information is used to indicate an H-SMF or an SMF, and then the serving communication agent network element selects one or more H-SMFs or SMFs that support the DNN, and sends the first response message to the mobility management network element.

Optionally, the selecting, by the serving communication agent network element, an I-SMF supporting location information of the UE based on the second parameter information includes:

the second parameter information further includes second target network element type indication information, where the second target network element type indication information is used to indicate that the serving communication agent network element selects I-SMF or V-SMF, and then the serving communication agent network element selects I-SMF or V-SMF that supports the location information of the UE.

In a tenth aspect, a method for selecting a session management network element is provided, including: a mobility management network element sends a first message to a serving communication agent network element, wherein the first message comprises first parameter information, the first message is used for requesting the serving communication agent network element to discover an SMF according to the first parameter information, and the first parameter information comprises a data network name DNN; the mobility management network element receives a first response message from the serving communication agent network element, the first response message including information of the one or more SMFs. Therefore, the mobility management element can obtain the information of the SMF to perform subsequent operations, for example, the mobility management element may determine whether the intermediate session management element I-SMF needs to be selected according to the information of the SMF.

In one possible implementation, the method further includes:

and the mobility management network element sends a second message to the serving communication agent network element, wherein the second message comprises second parameter information, the second parameter information is used for discovering I-SMF, and the second parameter information comprises the position information of the UE.

In one possible implementation, the method further includes:

before the mobility management network element sends the second message to the serving communication agent network element, the mobility management network element determines whether an SMF supporting the location information of the UE exists according to the information of the SMF, and if the SMF supporting the location information of the UE does not exist, the mobility management network element determines that the I-SMF needs to be selected.

In one possible implementation, the method further includes:

the mobility management network element receives the information of the I-SMF from the serving communication agent network element.

Optionally, the mobility management network element may receive a response message from the serving communication agent network element, where the response message is sent to the serving communication agent network element by the I-SMF, and a header or a message body of the response message carries information of the I-SMF.

In one possible implementation, the method further includes:

the first parameter information further includes first indication information, where the first indication information is used to indicate that the serving communication agent network element replies a response message to the mobility management network element after discovering the H-SMF or SMF.

Optionally, the first parameter information further includes first target network element type indication information, where the first target network element type indication information is used to indicate an H-SMF or an SMF, and is used to indicate the serving communication agent network element to reply a response message to the mobility management network element after discovering the H-SMF or the SMF.

In an eleventh aspect, there is provided a method of selecting a session management network element, including: the serving communication agent network element receiving a first message from the mobility management network element; the service communication agent network element acquires first parameter information and second parameter information according to the first message, wherein the first parameter information is used for selecting a first SMF, and the second parameter information is used for selecting a second SMF; and the service communication agent network element selects one or more first SMFs according to the first parameter information and selects a second SMF according to the second parameter information. Therefore, the serving communication agent network element may determine that the first SMF and the second SMF need to be selected simultaneously according to the first parameter information and the second parameter information, thereby simplifying the logic of the serving communication agent so that the serving communication agent does not need to understand the service-related logic.

In one possible implementation, the method further includes:

the first message includes indication information, where the indication information is used to indicate that a serving communication agent includes information of the first SMF in the second request message, or the indication information is used to indicate that the serving communication agent network element sends the second request message to the second SMF.

In one possible implementation, the method further includes:

the indication information is included in first parameter information, where the indication information is a first network element type indication, and the first network element type indication is used to indicate that the serving communication agent network element selects H-SMF or SMF, and then the serving communication agent network element determines that the second request message includes information of the first SMF;

or, the indication information is included in second parameter information, where the indication information is a second network element type indication, and the second network element type indication is used to indicate that the serving communication agent network element selects V-SMF or I-SMF, and then the serving communication agent network element determines to send the second request message to the second SMF.

In one possible implementation, the method further includes:

In a twelfth aspect, a method for selecting a session management network element is provided, including: a mobility management network element sends a first message to a service communication agent network element, wherein the first message comprises first parameter information and second parameter information, the first parameter information is used for selecting a first SMF, and the second parameter information is used for selecting a second SMF; and the mobility management network element receives the information of the fifth SMF and the information of the second SMF from the service communication agent network element. Therefore, the mobility management network element may obtain the two SMFs determined by the serving communication agent network element, so that when the mobility management network element operates in the agent discovery mode, the creation of a session including the two SMFs is still supported, and thus, the application scenario in which the mobility management network element operates in the agent discovery mode is not limited.

Optionally, before requesting the serving communication agent network element to select the first SMF and the second SMF, the mobility management network element determines whether the second SMF needs to be selected.

In one implementation, before the mobility management network element sends the first message to the serving communication agent network element, the mobility management network element requests the serving communication agent network element to select an SMF that supports both the location information of the UE and the DNN, and if the SMF that supports both the location information of the UE and the DNN does not exist, the mobility management network element determines that the first SMF and the second SMF need to be selected.

In a thirteenth aspect, a communication device is provided, which is a serving communication proxy network element (such as an SCP entity), and may also be a chip or a circuit, and is configured to execute the method performed by the serving communication proxy network element in the method in any aspect or any possible implementation manner of any aspect. Specifically, the communication device may be implemented by hardware, or may be implemented by hardware executing corresponding software.

In some possible implementations, the communication device comprises means for performing the method performed by the serving communication agent network element in any of the above aspects or any of the possible implementations of any of the aspects.

In some possible implementations, the communication device includes: a processor and a memory; the memory is configured to store instructions that, when executed by the communication apparatus, cause the communication apparatus to perform the method performed by the serving communication agent network element in any of the above aspects or any possible implementation manner of any aspect. It should be noted that the memory may be integrated into the processor or may be independent from the processor.

In some possible implementations, the communication device includes a processor configured to be coupled to a memory, and to read instructions in the memory and execute the method performed by the serving communication agent network element in any one of the above aspects or any possible implementation of any one of the above aspects according to the instructions.

In a fourteenth aspect, a communication device is provided, which is a mobility management network element (such as an AMF entity), and may also be a chip or a circuit, and is configured to perform the method performed by the mobility management network element in the method of any aspect or any possible implementation manner of any aspect. Specifically, the communication device may be implemented by hardware, or may be implemented by hardware executing corresponding software.

In some possible implementations, the communications apparatus includes means for performing the method performed by the mobility management network element in any of the above aspects or any possible implementations of any aspect.

In some possible implementations, the communication device includes: a processor and a memory; the memory is configured to store instructions that, when executed by the communication apparatus, cause the communication apparatus to perform the method performed by the mobility management network element in any one of the above aspects or any possible implementation manner of any one of the above aspects. It should be noted that the memory may be integrated into the processor or may be independent from the processor.

In some possible implementations, the communication device includes a processor configured to couple with a memory, and to read instructions in the memory and execute the method performed by the mobility management network element in any one of the above aspects or any possible implementation of any one of the above aspects according to the instructions.

In a fifteenth aspect, a communication device is provided that includes a processor, a memory, and a transceiver. The processor is coupled to the memory and the transceiver. The memory is for storing instructions, the processor is for executing the instructions, and the transceiver is for communicating with other network elements under control of the processor. The processor, when executing the instructions stored by the memory, causes the processor to perform the method of any of the above aspects or any possible implementation of any aspect.

In a sixteenth aspect, there is provided a computer-readable storage medium storing a program for causing a communication device to perform any of the above aspects, and any of its various implementations, a method of selecting a session management network element.

In a seventeenth aspect, the present application also provides a computer program product comprising instructions that, when run on a computer, cause the computer to perform the method of selecting a session management network element of any of the above aspects.

In an eighteenth aspect, the present application further provides a system, where the system includes a serving communication proxy network element, and the serving communication proxy network element is configured to perform the steps performed by the serving communication proxy network element in any of the methods of the first aspect and the first aspect.

In some possible implementations, the system may further include a mobility management network element, and the mobility management network element may be configured to perform the steps performed by the mobility management network element in any one of the methods of the second aspect and the second aspect.

In some possible implementations, the system may further include other devices that interact with one or more of the serving communication agent network element and the mobility management network element in the solution provided in this embodiment of the present application, and the like.

In a nineteenth aspect, the present application further provides a system, where the system includes a serving communication proxy network element, and the serving communication proxy network element is configured to perform the steps performed by the serving communication proxy network element in any of the methods of the third aspect and the fourth aspect.

In some possible implementations, the system may further include a mobility management network element, and the mobility management network element may be configured to perform the steps performed by the mobility management network element in any one of the methods of the fourth aspect and the fourth aspect.

In a twentieth aspect, the present application further provides a system comprising a serving communication proxy network element, the serving communication proxy network element being operable to perform the steps performed by the serving communication proxy network element in any of the methods of the fifth and the seventh aspects.

In some possible implementations, the system may further include a mobility management network element, and the mobility management network element may be configured to perform the steps performed by the mobility management network element in any one of the methods of the sixth aspect and the sixth aspect.

In a twenty-first aspect, the present application further provides a system, where the system includes a serving communication proxy network element, and the serving communication proxy network element is configured to perform the steps performed by the serving communication proxy network element in any one of the methods in the seventh aspect and the seventh aspect.

In some possible implementations, the system may further include a mobility management network element, and the mobility management network element may be configured to perform the steps performed by the mobility management network element in any one of the methods of the eighth aspect and the eighth aspect.

In a twenty-second aspect, the present application further provides a system, which includes a serving communication proxy network element, and the serving communication proxy network element is operable to perform the steps performed by the serving communication proxy network element in any of the methods of the ninth aspect and the ninth aspect.

In some possible implementations, the system may further include a mobility management network element, and the mobility management network element may be configured to perform the steps performed by the mobility management network element in any one of the methods of the tenth aspect and the tenth aspect.

In a twenty-third aspect, the present application further provides a system, which includes a serving communication proxy network element, and the serving communication proxy network element is operable to perform the steps performed by the serving communication proxy network element in any of the methods of the eleventh aspect and the eleventh aspect.

In some possible implementations, the system may further include a mobility management network element, and the mobility management network element may be configured to perform the steps performed by the mobility management network element in any one of the methods of the twelfth aspect and the twelfth aspect.

A twenty-fourth aspect provides a communication chip having instructions stored thereon, which when run on a communication device, cause the communication chip to perform the method of any of the above aspects or any possible implementation of any aspect.

Drawings

FIG. 1 is an exemplary diagram of a system architecture to which embodiments of the present application may be applied.

Fig. 2 is a schematic interaction diagram of a method of selecting a session management network element according to an embodiment of the application.

Fig. 3 is another schematic interaction diagram of a method of selecting a session management network element according to an embodiment of the application.

Fig. 4 is a schematic interaction diagram of a method of selecting a session management network element according to another embodiment of the present application.

Fig. 5 is another schematic interaction diagram of a method of selecting a session management network element according to another embodiment of the present application.

Fig. 6 is a schematic interaction diagram of a method of selecting a session management network element according to yet another embodiment of the present application.

Fig. 7 is a schematic interaction diagram of a method of selecting a session management network element according to yet another embodiment of the present application.

Fig. 8 is a schematic interaction diagram of a method of selecting a session management network element according to another embodiment of the present application.

Fig. 9 is a possible exemplary block diagram of an apparatus involved in an embodiment of the present application.

Fig. 10 is a schematic structural diagram of an apparatus for selecting a session management network element according to an embodiment of the present application.

Fig. 11 is a possible exemplary block diagram of another apparatus involved in the embodiments of the present application.

Fig. 12 is a schematic block diagram of another apparatus for selecting a session management network element according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

In the embodiments of the present application, "a plurality" may be understood as "at least two"; "plurality" is to be understood as "at least two".

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a global system for mobile communications (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a General Packet Radio Service (GPRS), a long term evolution (long term evolution, LTE) system, a LTE Frequency Division Duplex (FDD) system, a LTE Time Division Duplex (TDD), a universal mobile telecommunications system (universal mobile telecommunications system, UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a future fifth generation (5G) or new radio NR (5G) system, and the like.

Various aspects or features of the disclosure may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROM), card, stick, or key drive, etc.). In addition, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.

A UE in the embodiments of the present application may refer to a terminal (terminal), an access terminal, a terminal in V2X communication, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a terminal device, a wireless communication device, a user agent, or a user equipment. The terminal may also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a V2X device (e.g., a vehicle or an On Board Unit (OBU) in a vehicle), a wearable device, a terminal device in a future 5G network or a terminal device in a future evolved Public Land Mobile Network (PLMN), and the like, which are not limited in this embodiment of the present application.

The session management network element is mainly used for session management in a mobile network, such as session creation, modification, and release, including tunnel maintenance between a UPF and AN), selection and control of the UPF, SSC (service and session continuity) mode selection, roaming, and other session related functions. The specific functions include, for example, allocating an Internet Protocol (IP) address to a user, selecting a user plane network element providing a message forwarding function, and the like. In 5G, the session management network element may be a Session Management Function (SMF) network element, and in future communications such as 6G, the session management network element may still be an SMF network element or have another name, which is not limited in this application.

The communication agent network element is mainly used for supporting the message forwarding function between the network elements and the service discovery function. In 5G, the communication proxy network element may be a Service Communication Proxy (SCP) network element, and in future communication such as 6G, the communication proxy network element may still be an SCP network element, or may have another name, which is not limited in this application.

The mobility management network element mainly comprises the following functions: connection management, mobility management, registration management, access authentication and authorization, reachability management, security context management, and other access and mobility related functions. In 5G, the mobility management network element may be an access and mobility management function (AMF) network element, and in future communication such as 6G, the mobility management network element may be an AMF network element or has another name, which is not limited in this application.

The policy control network element comprises a user subscription data management function, a policy control function, a charging policy control function, policy control providing and policy related functions such as acquiring subscription information related to policy decision from the UDR, quality of service (QoS) control, and the like. In 5G, the policy control network element may be a Policy Control Function (PCF) network element, and in future communications such as 6G, the policy control network element may still be a PCF network element, or have another name, which is not limited in this application.

The authentication server network element is mainly used for verifying a service function, storing a key, and performing an authentication server function by using an Extensible Authentication Protocol (EAP), interacting with the UDM to acquire user information, and performing authentication related functions, such as generating an intermediate key, to authenticate and authenticate a user. In 5G, the authentication server network element may be an authentication server function (AUSF) network element, and in future communications such as 6G, the user plane network element may still be an AUSF network element or have another name, which is not limited in this application.

And the data management network element is mainly used for storing user data, such as subscription information and authentication/authorization information. In 5G, the data management network element may be a Unified Data Management (UDM) network element, and in future communications such as 6G, the data management network element may still be a UDM network element or have another name, which is not limited in this application. Unified Data Manager (UDM) mainly includes the following functions: unified data management, support authentication credential processing in 3GPP authentication and key negotiation mechanisms, user identity processing, access authorization, registration and mobility management, subscription management, short message management and the like.

The user plane network element is mainly used for service processing of a user plane, such as service routing, packet forwarding, an anchoring function, quality of service (QoS) mapping and execution, identification and routing of an uplink to a data network, downlink packet buffering, notification triggering of downlink data arrival, connection with an external data network, and the like. In 5G, the user plane network element may be a User Plane Function (UPF) network element, and in future communications such as 6G, the user plane network element may still be a UPF network element or have another name, which is not limited in this application.

An access network device, which may also be referred to as a Radio Access Network (RAN) device, is a device that provides a terminal device with a wireless communication function. Access network devices include, but are not limited to: next generation base station (G node B, gNB), evolved node B (eNB), Radio Network Controller (RNC), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), home base station (e.g., home evolved node B, or home node B, HNB), Base Band Unit (BBU), transmission point (TRP), Transmission Point (TP), mobile switching center, etc. in 5G. The embodiment of the present application does not limit the specific technology and the specific device form adopted by the access network device.

A User Equipment (UE), which is a device with a wireless transceiving function, can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal device may be a mobile phone (mobile phone), a tablet computer (pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal, an Augmented Reality (AR) terminal, 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 (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and the like.

Data Networks (DNs) are mainly used to provide services for users, such as operator services, internet access services, and third-party services.

The Network Exposure Function (NEF) mainly includes the following functions: the service and the capability provided by the safe open 3GPP network function have internal opening or are opened to a third party and the like; and converting or translating information interacted with the AF and information interacted with internal network functions, such as AF service identification and internal 5G core network information, such as DNN, S-NSSAI and the like.

The network function storage function (NRF) mainly includes the following functions: service discovery functions, maintaining NF text of available Network Function (NF) instances and the services they support.

The Application Function (AF) mainly includes the following functions: and interacting with the 3GPP core network to provide services or services, including interacting with NEF, interacting with a policy framework and the like.

The Network Slice Selection Function (NSSF) mainly includes the following functions: selecting a set of network slice instances for the UE, determining allowed NSSAIs, and determining a set of AMFs that may serve the UE, etc.

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 above-described functionality may be divided into one or more services, and further, services may exist independently of 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.

Optionally, the network element or the function may be implemented by one device, or may be implemented by multiple devices together, or may be a functional module in one device, which is not specifically limited in this embodiment of the present application.

It should be understood that, for the unified description, if the above network elements appear below, the above description of the functions included in each network element may be equally applicable, and will not be described in detail in the next appearance.

FIG. 1 is an exemplary diagram of a system architecture to which embodiments of the present application may be applied. The network elements in the system architecture include control plane functions and user plane network functions (such as UPF, etc.). The control plane functions communicate through a servitization interface. The interface between the control plane functions and the access network or UPF is a non-serving interface. For example, the Control plane network Function may include an AMF, an SMF, a Policy Control Function (PCF), a UDM, an Authentication Server Function (AUSF), and the like. As shown in fig. 1, the system architecture specifically includes an authentication server function AUSF, AMF, SMF, Service Communication Proxy (SCP), NSSF, NEF, NRF, PCF, UDM, AF, UPF, DN, RAN, and User Equipment (UE). The control plane functions communicate with each other through the following service interfaces: the external service interface provided by the NSSF can be Nnssf, the external service interface provided by the NEF can be Nnef, the external service interface provided by the NRF can be Nnrf, and the external service interface provided by the AMF can be Namf; the service interface provided by the SMF can be Nsmf; the serving interface provided by the UDM can be Nudm, and the serving interface provided by the AF can be Naf; the service interface externally provided by the PCF can be Npcf, and the service interface externally provided by the AUSF can be Nausf; the interface between the control plane functions and the RAN and UPF is a non-serving interface. The relevant description may refer to the 5G system architecture (5G system architecture) in the 23501 standard. The AMF is connected with the RAN through an N2 interface, and is connected with the UE through an N1 interface. The SMF and UPF are connected through an N4 interface. The RAN and the UPF are connected via an N3 interface. The UPF and DN are connected via the N6 interface. The SCP is used to pass messages between control plane network elements in the indirect communication mode and to support discovery of network elements and network functions.

It should be noted that the name of each network element (such as SCP, AMF, SMF, etc.) included in fig. 1 is only a name, and the name does not limit the function of the network element itself. In the 5G network and other networks in the future, the network elements may also be given other names, which is not specifically limited in the embodiment of the present application. For example, in a 6G network, some or all of the above network elements may use the terminology in 5G, or may use other nomenclature, and so on, which are described herein in a unified manner and will not be described again below.

It should be understood that whether the interface in fig. 1 is a service interface or not does not limit the scope of the embodiments of the present application, for example, if the non-service interface in fig. 1 is evolved into a service interface in the future, the embodiments of the present application still apply.

As explained herein, the various embodiments described below may be applicable to other scenarios where a proxy discovery mode is required and two network elements need to be discovered simultaneously, e.g., selecting H-PCF and V-PCF, etc. using proxy discovery mode.

For convenience of description, the following description takes a session management network element as an SMF, but this is not a limitation to the embodiments of the present application.

Fig. 2 shows a schematic interaction diagram of a method 200 of selecting a session management network element according to an embodiment of the application. In the method 200, the method at the serving communication proxy network element side may be performed by the serving communication proxy network element (such as SCP) or a chip (or module) in the serving communication proxy network element, and the method at the mobility management network element side may be performed by the mobility management network element (such as AMF) or a chip (or module) in the mobility management network element. As shown in fig. 2, the method 200 includes:

s210, the mobility management network element sends a first message to the serving communication agent network element. Correspondingly, the service communication proxy network element receives the first message.

Optionally, the first message may be a first request message, and the first parameter information may be carried in a header of the first request message, or may also be located in a message body of the first request message, which is not limited to this.

S220, the serving communication agent network element obtains the first parameter information according to the first message.

The first message is used for requesting the serving communication agent network element to select an SMF according to the first parameter information (and acquiring a first request message according to the first message, and sending the first request message to the SMF).

Optionally, the first request message may be for requesting to create a session. Specifically, for example, the mobility management network element receives a create session request message of the UE, and needs to send the create session request message to the SMF, so that the SMF can create a session for the UE. And the mobility management network element generates the first request message based on a session creation request message from the UE and determines parameters for selecting the SMF. If the mobile communication proxy network element operates in the proxy discovery mode, the mobility management network element may send the first request message and the parameter one for selecting the SMF to the serving communication proxy network element.

Here, the first parameter information includes location information of the UE and a data network name DNN. For example, the logical expression of the first parameter information is: location of UE & DNN.

Optionally, the first parameter information may further include network slice information, such as S-NSSAI. For example, the logical expression of the first parameter information is: location of UE & DNN & S-NSSAI.

S230, the serving communication agent network element determines whether there is an SMF that satisfies the first parameter information.

Optionally, after obtaining the first parameter information, the serving communication agent network element may query the NRF to determine whether there is an SMF that satisfies the location information of the UE and the DNN at the same time.

S240, in case that there is no SMF satisfying the first parameter information, the serving communication agent network element selects one or more first SMFs supporting the DNN, and sends a reject message to the mobility management network element, where the reject message includes information of the one or more first SMFs.

If the serving communication agent network element does not find the SMFs which simultaneously satisfy the location information of the UE and the DNN, the serving communication agent network element selects a list of the SMFs (such as one or more first SMFs) supporting the DNN, and then carries the information of the one or more first SMFs in the list and sends the information to the mobility management network element. Wherein the information of the one or more first SMFs comprises one or more of the following information: an identification (e.g., instance Identification (ID)) of the first SMF, an endpoint address of the first SMF, and service area information of the first SMF.

Here, the serving communication agent network element may perform the above step S240 based on the target network element type indication information or the first indication information.

Optionally, the first parameter information may further include target network element type indication information, and if the target network element indication information is used to indicate that the serving communication agent network element selects an SMF, the serving communication agent network element selects one or more first SMFs that support the DNN if it is determined that there is no SMF that satisfies the first parameter information, and sends information of the one or more first SMFs to the mobility management network element.

Or, optionally, the serving communication agent network element receives first indication information from the mobility management network element, where the first indication information is used to indicate: and the serving communication agent network element selects one or more first SMFs supporting the DNN under the condition that the serving communication agent network element determines that the SMFs meeting the first parameter information do not exist, and sends information of the one or more first SMFs to the mobility management network element. If the serving communication agent network element receives the first indication information, in case that no SMF satisfying both the location information of the UE and the DNN is found, selecting a list of SMFs (such as one or more first SMFs) supporting the DNN, and then sending information of the one or more first SMFs to the mobility management network element. It should be further noted that the first indication information is further used for indicating: and the serving communication agent network element sends the first request message to the SMF only under the condition that the SMF selected by the serving communication agent network element simultaneously meets the position information and DNN of the UE. Therefore, even if the serving communication agent network element selects an SMF (such as one or more first SMFs) that supports the DNN, the serving communication agent network element does not send the first request message to the SMF because the SMF selected by the serving communication agent network element does not support the location information of the UE.

Optionally, the first indication information may be carried in the first parameter information.

Optionally, in an implementation manner, the mobility management network element includes, in the first parameter information sent to the serving communication agent network element, a logical relationship description between first parameters, for example, when the first parameter includes DNN and UE location information, the logical relationship description is: (DNN AND UE location information) OR (DNN) that instructs the serving communication agent network element to select an SMF that satisfies both DNN AND UE location information, or to select an SMF that satisfies DNN. Correspondingly, the service communication agent network element acquires the SMF network element meeting the logical relation according to the logical relation.

Therefore, in this embodiment of the present application, the serving communication agent network element enables the mobility management network element to acquire information of the first SMF by sending one or more first SMFs supporting DNN to the mobility management network element, so as to perform subsequent operations. In this way, the mobility management network element may send information of the first SMF to the second SMF. For example, in a home and rural routing mode, the mobility management network element may send the received information of the H-SMF to the V-SMF; in the enhanced topology mode, the mobility management network element may send information of the I-SMF to the SMF. Thus, the method for selecting the session management network element in the embodiment of the present application is applicable to both the home routing mode and the enhanced mode.

If the mobility management network element receives the reject message, where the reject message includes the list of the first SMF selected by the serving communication agent network element, the mobility management network element determines that a second SMF needs to be selected (for example, the second SMF may be an I-SMF). The mobility management network element may regenerate the parameter information, i.e. the second parameter information, which is used for discovering said second SMF.

Optionally, as shown in fig. 3, the method 200 further includes:

s250, the mobility management network element sends a second message to the serving communication agent network element. The serving communication agent network element receives a second message from the mobility management network element.

Optionally, the second message includes second parameter information and one or more third SMFs of the one or more first SMFs, where the second parameter information includes location information of the UE, and the one or more third SMFs are used to send to the second SMF.

S260, the serving communication agent network element obtains second parameter information according to the second message, where the second parameter information includes location information of the UE. Here, the second parameter information does not carry DNN, but carries location information of the UE, so as to select the second SMF. Optionally, in the home routing mode, the HPLMNID is not carried in the second parameter information.

Optionally, the second message may be understood as a second request message, and the second parameter information may be carried in a header of the second request message or located in a message body of the second request message, which is not limited herein. Optionally, the second request message may include information of one or more of the one or more first SMFs. Optionally, the information of the first SMF is included in a message body of the second request message.

S270, the serving communication agent network element selects the second SMF based on the second parameter information.

And the serving communication agent network element uses the second parameter information (including the position information of the UE) to execute a discovery process and selects the second SMF supporting the position information of the UE. It should be understood that the discovery process performed by the serving communication agent network element may refer to the description in the existing protocol, and is not described herein for brevity.

Optionally, the second parameter information includes network element type information, where the network element type information is used to indicate that the serving communication agent network element selects an intermediate SMF.

S280, the service communication proxy network element obtains a second request message according to the second message, and sends the second request message to the second SMF.

And if the serving communication agent network element finds a second SMF meeting the position information of the supporting UE, sending the second request message to the selected second SMF. Specifically, the serving communication agent network element needs to replace the host name in the second request message sent by the mobility management network element with the address or FQDN corresponding to the selected second SMF.

Optionally, the second SMF may perform an operation related to the second request message after receiving the second request message. For example, if the second request message is used to create a session, the second SMF creates session resources for the second request message, and if the second request message includes information of the specified SMF, the second SMF may further interact with the specified SMF, so as to establish the session on the specified SMF. Here, the session processing procedure of the second SMF and the specified SMF may refer to the description in the prior art, and for brevity, is not described herein again.

Optionally, after performing the operation related to the second request message, the second SMF may send a message that the execution is successful (for example, a message that the session establishment is successful), that is, a response message, to the mobility management network element. Optionally, in the proxy discovery mode, the second SMF may first send a response message to the serving communication proxy network element, in order for the serving communication proxy network element to forward to the mobility management network element. When forwarding the response message to the mobility management network element, the serving communication agent network element may carry information of the second SMF in the response message.

Optionally, the method 200 further comprises: and the service communication agent network element sends the information of the second SMF to the mobility management network element.

Specifically, after receiving the response message of the second SMF, the serving communication agent network element may carry the information of the second SMF in the response message, and send the information of the second SMF to the mobility management network element through the response message. Optionally, the information of the second SMF may be included in a header of the response message or a message body of the response message, which is not limited in this embodiment of the present application.

Optionally, the information of the second SMF includes at least service area information of the second SMF. Optionally, the information of the second SMF may further include identification information of the second SMF, such as an intermediate SMF (I-SMF) instance identification.

Optionally, the identification information of the second SMF may also be used to send, by the mobility management network element, the identification information of the second SMF to the target mobility management network element, so that the current mobility management network element obtains the service area information of the second SMF according to the identification information of the second SMF, and thus the target mobility management network element determines whether to replace the existing SMF with the second SMF. Or, optionally, after obtaining the service area information of the second SMF, the mobility management network element may send the service area information of the second SMF to the target mobility management network element, so that the target mobility management network element determines whether to replace the existing SMF with the second SMF according to the service area information of the second SMF.

The unified description here is: in various embodiments of the present application (including the first and second SMFs presented below), if the home routing mode is selected, the first SMF may be an H-SMF and the second SMF may be a V-SMF; and if the topology mode is the enhanced topology mode, the first SMF is the SMF, and the second SMF is the I-SMF.

If the first SMF is H-SMF and the second SMF is V-SMF, the first parameter information further comprises the identification HPLMN ID of the home public land mobile network, the first parameter information is used for discovering the home session management function H-SMF, and the reject message comprises information of one or more H-SMFs.

Here, the serving communication agent network element may determine whether there is a simultaneous satisfaction of: location information of the UE, DNN, and SMF of HPLMN ID. If there are no SMFs that satisfy the location information, DNN and HPLMN ID of the UE at the same time, the serving communication proxy network element may select one or more H-SMFs that support the HPLMN ID and the DNN.

The present application also provides another method of selecting SMF. Fig. 4 shows a schematic interaction diagram of a method 300 of selecting an SMF according to another embodiment of the present application. In the method 300, the method at the serving communication proxy network element side may be performed by the serving communication proxy network element (such as SCP) or a chip (or module) in the serving communication proxy network element, and the method at the mobility management network element side may be performed by the mobility management network element (such as AMF) or a chip (or module) in the mobility management network element. As shown in fig. 4, the method 300 includes:

s310, the mobility management network element sends a first message to the serving communication agent network element. Correspondingly, the service communication proxy network element receives the first message.

Here, the explanation of the first message may refer to the description of the first message in the method 200, and for brevity, the description is not repeated here.

S320, the serving communication agent network element obtains the first parameter information according to the first message, where the first message is used to request the serving communication agent network element to select an SMF according to the first parameter information, and then obtains a first request message according to the first message, and sends the first request message to the SMF.

Here, for the explanation of the first message or the explanation of the first parameter information, reference may be made to the description of the first message in the method 200, and details are not described here for brevity.

S330, the serving communication agent network element determines whether there is an SMF that satisfies the first parameter information.

It should be understood that the description or explanation of steps S310-S330 may refer to the description of steps S210-S230 in the method 200, which is not repeated herein.

S340, in the case that there is no SMF satisfying the first parameter information, the serving communication agent network element sends a rejection message to the mobility management network element, where the rejection message is used to indicate that there is no SMF satisfying the first parameter information.

And if the serving communication agent network element does not find the SMF which simultaneously meets the position information of the UE and the DNN, sending a rejection message to the mobility management network element to inform the mobility management network element that the SMF which meets the first parameter information does not exist. Optionally, the reject message may carry a cause value, where the cause value is used to indicate, to a mobility management network element, that the serving communication agent network element does not find an SMF that satisfies the first parameter information. The difference with step S240 in the method 200 is that the DNN-capable first SMF selected by the serving communication agent network element is not included in the reject message.

Optionally, after obtaining the first parameter information, the serving communication agent network element may store the DNN and the location information of the UE.

After receiving the reject message, the mobility management network element determines that two SMFs, such as I-SMF and SMF, need to be selected according to the cause value of the reject message.

S350, the serving communication agent network element receives second parameter information from the mobility management network element, where the second parameter information includes the DNN.

Here, the second parameter information includes DNN. The serving communication agent network element selects an SMF based on the DNN.

S360, the serving communication agent network element selects one or more first SMFs supporting the second parameter information, and sends a first response message to the mobility management network element, where the first response message includes information of the one or more first SMFs.

That is, if the serving communication agent network element selects one or more first SMFs supporting the second parameter information, the information of the one or more first SMFs is sent to the mobility management network element. Here, for the explanation or the related description of the information of the one or more first SMFs, reference may be made to the description in the method 200, and details are not described here for brevity.

Here, the serving communication agent network element may perform the above step S360 based on the target network element type indication information or the first indication information.

Optionally, the second parameter information may further include first target network element type indication information, and if the first target network element indication information is used to indicate that the serving communication agent network element selects an SMF, the serving communication agent network element selects one or more first SMFs that support the DNN, and sends the first response message to the mobility management network element. That is, the serving communication agent network element does not send a message from a mobility management network element to the first SMF.

Optionally, the second parameter information further includes first indication information, where the first indication information is used to indicate that the serving communication agent network element selects one or more first SMFs that support the DNN, and send the first response message to the mobility management network element. If the serving communication agent network element receives the first indication information, the serving communication agent network element selects one or more first SMFs supporting the DNN, does not send a request message to the first SMFs, and sends the one or more first SMFs to the mobility management network element. That is, the serving communication agent network element does not send a message to the selected first SMF.

Therefore, in this embodiment of the present application, the serving communication agent network element enables the mobility management network element to acquire information of the first SMF by sending one or more first SMFs supporting DNN to the mobility management network element, so as to perform subsequent operations. In this way, the mobility management network element may send information of the first SMF to the second SMF. For example, in the enhanced topology mode, the mobility management network element may send information of the I-SMF to the SMF.

Optionally, as shown in fig. 4, the method 300 further includes:

s370, the mobility management network element sends a second message to the serving communication agent network element. The serving communication agent network element receives a second message from the mobility management network element. Optionally, the second message includes third parameter information.

And S380, the service communication agent network element acquires the third parameter information according to the second message. The third parameter information includes location information of the UE. Here, the third parameter information does not carry DNN, but carries location information of the UE so as to select the second SMF.

Optionally, the second message may be understood as a second request message, and the third parameter information may be carried in a header of the second request message or located in a message body of the second request message, which is not limited herein. Optionally, the second request message may include information of one or more of the one or more first SMFs.

S390, the serving communication agent network element selects the second SMF based on the third parameter information.

And the serving communication agent network element uses the third parameter information (including the position information of the UE) to execute a discovery process and selects the second SMF supporting the position information of the UE. It should be understood that the discovery process performed by the serving communication agent network element may refer to the description in the existing protocol, and is not described herein for brevity.

Optionally, the third parameter information may further include second target network element type indication information, where the second target network element type indication information is used to indicate an intermediate SMF (i.e., I-SMF). If the serving communication agent network element obtains the second target network element type indication information, when selecting the SMF supporting the UE location information, it also selects the SMF conforming to the network element type indicated by the second target network element type indication information, that is, selects the middle SMF supporting the UE location information.

S391, the serving communication agent network element obtains a second request message according to the second message, and sends the second request message to the second SMF.

And if the serving communication agent network element finds the second SMF supporting the position information of the UE, sending the second request message to the selected second SMF. Specifically, the serving communication agent network element needs to replace the host name in the second request message sent by the mobility management network element with the address or FQDN corresponding to the selected second SMF.

Here, the subsequent operation of the second SMF receiving the second request message may be described with reference to the method 200, and for brevity, is not described herein again.

Optionally, the method 300 further comprises: s392, the serving communication agent network element sends the information of the second SMF to the mobility management network element.

Specifically, after receiving the response message of the second SMF, the serving communication agent network element may carry the information of the second SMF in the response message, and send the information of the second SMF to the mobility management network element through the response message.

Optionally, the information of the second SMF includes at least service area information of the second SMF. Optionally, the information of the second SMF may further include identification information of the second SMF, such as an I-SMF instance identification.

Here, for the description of the identification information of the second SMF, reference may be made to the description in the method 200, and for brevity, the description is not repeated here.

The present application also provides a method for selecting an SMF in yet another embodiment. Fig. 6 shows a schematic interaction diagram of a method 400 of selecting an SMF according to yet another embodiment of the present application. The method 400 supports selection of an SMF in a home routing mode and also supports a scenario in which two SMFs need to be selected in a non-home routing mode. In the method 400, the method at the serving communication proxy network element side may be performed by the serving communication proxy network element (such as SCP) or a chip (or module) in the serving communication proxy network element, and the method at the mobility management network element side may be performed by the mobility management network element (such as AMF) or a chip (or module) in the mobility management network element. As shown in fig. 6, the method 400 includes:

s410, the mobility management network element sends a first message to the serving communication agent network element. Correspondingly, the service communication proxy network element receives the first message.

Here, after receiving the session establishment request sent by the UE, the mobility management network element determines that the session adopts the home routing mode, that is, the session needs to include the H-SMF and the V-SMF. Specifically, the mobility management network element may determine that the session adopts the home routing mode according to subscription information of the UE or other information. The specific process of determining that the session adopts the home routing mode by the mobility management element may refer to descriptions in the prior art, and for brevity, details are not described here.

If the session is not in the home routing mode and the mobility management element cannot determine whether to select the I-SMF, the mobility management element may first send a first message to the serving communication agent element for selecting the SMF.

And S420, the service communication agent network element acquires the first parameter information according to the first message, the first message is used for requesting the service communication agent network element to discover the H-SMF according to the first parameter information, and the first parameter information comprises an identifier HPLMN ID and a data network name DNN of a home public land mobile network. The HPLMN ID refers to the PLMN ID of the PLMN in which the H-SMF is located.

If the session is not in the home routing mode, the first parameter does not include the HPLMN ID, and the first parameter information includes other parameters for selecting the SMF except the location information of the UE, the serving communication agent network element discovers the SMF according to the first parameter information.

S430, the serving communication agent network element selects one or more H-SMFs satisfying the first parameter information, and sends a first response message to the mobility management network element, where the first response message includes information of the one or more H-SMFs.

That is, if the serving communication agent network element discovers one or more H-SMFs satisfying the HPLMN ID and DNN or discovers one or more SMFs satisfying the DNN, the serving communication agent network element may transmit information of the discovered one or more H-SMFs or SMFs to the mobility management network element.

Here, the serving communication agent network element may perform the above step S430 based on the target network element type indication information or the first indication information.

Optionally, the first parameter information may further include first target network element type indication information, and if the first target network element indication information is used to indicate that the serving communication agent network element selects an H-SMF or an SMF, the serving communication agent network element selects one or more H-SMFs that support the HPLMN ID and the DNN or selects one or more SMFs that support the DNN, and sends information of the one or more H-SMFs or SMFs to the mobility management network element.

Or, optionally, the serving communication agent network element receives first indication information from the mobility management network element, where the first indication information is used to indicate: and the service communication agent network element replies a response message to the mobility management network element after finding the H-SMF or the SMF. If the serving communication agent network element receives the first indication information, a first response message is sent to the mobility management network element under the condition that the HPLMN ID and one or more H-SMFs of the DNN are simultaneously met or one or more SMFs supporting the DNN are found, namely the information of the one or more H-SMFs or SMFs is sent to the mobility management network element. Optionally, the first indication information is further used for indicating: the serving communication agent network element does not send the first request message to the selected H-SMF or SMF. Alternatively, the first indication information may be home routing indication information.

Therefore, in the home and rural routing mode, the serving communication agent network element enables the mobility management network element to acquire the information of the H-SMF by sending one or more H-SMFs supporting the HPLMNID and the DNN to the mobility management network element, so as to perform subsequent operations, for example, the mobility management network element may send the received information of the H-SMF to the V-SMF. In the non-home routing mode, the serving communication agent network element may send one or more SMFs supporting DNN to the mobility management network element, and the mobility management network element may obtain information of the SMFs, thereby performing subsequent operations, for example, the mobility management network element may determine whether it is necessary to select an I-SMF according to the received information of the SMFs.

Optionally, the method 400 further comprises:

s440, the mobility management network element sends a second message to the serving communication agent network element. The serving communication agent network element receives a second message from the mobility management network element.

S450, the serving communication agent network element obtains second parameter information according to the second message, where the second parameter information includes location information of the UE.

Optionally, the second message may be understood as a second request message, and the second parameter information may be carried in a header of the second request message or located in a message body of the second request message, which is not limited herein.

S460, the service communication agent network element selects V-SMF or I-SMF according to the second parameter information.

That is, the serving communication agent network element selects a V-SMF supporting location information of the UE based on the second parameter information. The serving communication proxy network element may query the NRF to obtain a V-SMF or I-SMF that satisfies the second parameter information.

Optionally, the second parameter information further includes second target network element type indication information, where the second target network element type indication information is used to indicate that the serving communication agent network element selects V-SMF or I-SMF. If the serving communication agent network element obtains the second target network element type indication information, when selecting the SMF supporting the UE location information, it also selects the V-SMF or I-SMF that conforms to the network element type indicated by the second target network element type indication information, i.e. selects the V-SMF or I-SMF supporting the UE location information. Optionally, the serving communication agent network element determines, according to the second target network element type indication information, that the second request message needs to be sent to the selected V-SMF or I-SMF.

S470, the service communication agent network element obtains a second request message according to the second message, and sends the second request message to the V-SMF or I-SMF.

And if the service communication agent network element finds the V-SMF or the I-SMF supporting the position information of the UE, sending the second request message to the selected V-SMF or I-SMF. Specifically, the serving communication agent network element needs to replace the host name in the second request message sent by the mobility management network element with the address or FQDN corresponding to the selected V-SMF or I-SMF.

Optionally, the V-SMF or the I-SMF may perform an operation related to the second request message after receiving the second request message. For example, if the second request message is used to create a session, the V-SMF or I-SMF creates session resources for the second request message, and if the second request message includes information of a specified SMF, the V-SMF or I-SMF may further interact with the specified SMF (such as H-SMF) to establish the session on the specified SMF. Here, the session processing procedure of the V-SMF or the I-SMF and the specified SMF may refer to the description in the prior art, and is not described herein for brevity.

Optionally, after performing the operation related to the second request message, the V-SMF or the I-SMF may send a message that the execution is successful (for example, a message that the session establishment is successful), that is, a response message, to the mobility management network element. Optionally, in the proxy discovery mode, the V-SMF or the I-SMF may first send a response message to the serving communication proxy network element in order for the serving communication proxy network element to forward to the mobility management network element. Optionally, the V-SMF or I-SMF may carry information of the V-SMF or I-SMF in the response message; or, optionally, when the serving communication agent network element forwards the response message to the mobility management network element, the V-SMF or I-SMF information may be carried in the response message. Optionally, the information of the V-SMF or the I-SMF may be carried in a header of the response message or a message body of the response message, which is not limited in this embodiment of the present application.

Optionally, the method 400 further comprises: and the service communication agent network element sends the information of the V-SMF or the I-SMF to the mobility management network element.

Specifically, after receiving the response message of the V-SMF or I-SMF, the serving communication agent network element may carry the information of the V-SMF or I-SMF in the response message, and send the information of the second SMF to the mobility management network element through the response message.

Optionally, the information of the V-SMF or the I-SMF at least includes service area information of the V-SMF or the I-SMF, so that after the UE moves, the mobility management network element determines whether to reselect the V-SMF or the I-SMF according to the service area information of the V-SMF or the I-SMF and the location information of the UE. Optionally, the information of the second SMF may further include identification information of the V-SMF or the I-SMF, such as an I-SMF instance identification.

Optionally, the identification information of the V-SMF or I-SMF may also be used for the mobility management network element to send to the target mobility management network element, so that the current mobility management network element obtains the service area information of the V-SMF or I-SMF according to the identification information of the V-SMF or I-SMF, thereby enabling the target mobility management network element to determine whether a new V-SMF or I-SMF needs to be selected to replace the existing V-SMF or I-SMF. Or, optionally, after obtaining the service area information of the V-SMF or the I-SMF, the mobility management network element may send the service area information of the V-SMF or the I-SMF to the target mobility management network element, so that the target mobility management network element determines whether to select to replace the existing V-SMF or the I-SMF with a new SMF according to the service area information of the V-SMF or the I-SMF.

The present application also provides for a further method of selecting SMF. Fig. 7 shows a schematic interaction diagram of a method 500 of selecting an SMF according to yet another embodiment of the present application. In the method 500, the serving communication proxy network element may itself select the first SMF and the second SMF. Selection of SMF in support of home routing mode. The proxy network element (such as SCP) or a chip (or module) in the serving communication proxy network element, and the method at the mobility management network element side may be performed by the mobility management network element (such as AMF) or a chip (or module) in the mobility management network element. As shown in fig. 7, the method 500 includes:

s510, the mobility management network element sends a first message to the serving communication agent network element. Correspondingly, the service communication proxy network element receives the first message.

S520, the service communication agent network element acquires first parameter information according to the first message, wherein the first parameter information comprises the position information of the user equipment UE and the data network name DNN.

Optionally, the first message includes a first request message, and the first parameter information is carried in a header of the first request message or a message body of the first request message, which is not limited to this.

Here, the logical relationship between the location relationship of the UE and the DNN is determined by the serving communication agent network element, not specified by the mobility management network element. Optionally, the serving communication agent network element may set the location information of the UE to be optional, select one or more SMFs supporting DNN, then determine whether to support the location information of the UE according to the selected one or more SMFs, and select a second SMF if there is no SMF supporting the location information of the UE in the one or more SMFs; or, optionally, the serving communication agent network element may generate a certain logical expression according to the UE location information and the DNN, so as to select one or more SMFs satisfying both the UE location information and the DNN according to the logical expression, or select one or more SMFs satisfying the DNN and a second SMF supporting the UE location information when there is no SMF satisfying both the UE location information and the DNN.

S530, the serving communication agent network element determines whether there is an SMF satisfying the first parameter information.

Here, the serving communication agent network element may determine whether there is an SMF that satisfies both the location information and the DNN of the UE.

S540, in case there is no SMF satisfying the first parameter information, the serving communication agent network element selects one or more first SMFs according to the DNN, and selects a second SMF according to the location information of the UE.

That is, if there are no SMFs that satisfy both the location information of the UE and the DNN, the serving communication agent network element selects one or more first SMFs that support DNN and selects a second SMF that supports UE location information.

Therefore, in the embodiment of the present application, the serving communication proxy network element may determine itself whether the session needs to select two SMFs at the same time, so that when the mobility management network element operates in the proxy discovery mode, the creation of the session including two SMFs is still supported, and thus, the application scenario in which the mobility management network element operates in the proxy discovery mode is not limited.

Optionally, the method 500 further comprises:

and the service communication agent network element generates a second request message according to the first message and the one or more first SMFs, wherein the second request message comprises information of one or more fourth SMFs in the one or more selected first SMFs.

Here, the serving communication proxy network element may fill information of one or more fourth SMFs in the first request message, and generate a second request message, that is, a message body of the first request message sent by the mobility management network element needs to be modified by the serving communication proxy network element. For example, when the first request message sent by the mobility management element is an Nsmf _ pdusesion _ CreateSMContext request, the serving communication agent element inserts information of one or more fourth SMFs into a message body of the message, so that the second SMF may select one fifth SMF to send a message according to the information of the one or more fourth SMFs, and complete session establishment.

Or, optionally, the serving communication agent network element may add information of one or more fourth SMFs in a header of the first request message without modifying a message body of the first request message, to obtain the second request message, that is, the header of the second request message carries the information of one or more fourth SMFs. Thus, the second SMF needs to additionally read the header of the second request message when processing the session, so as to obtain information of the fifth SMF (the fifth SMF is an SMF of one or more fourth SMFs).

S550, the serving communication agent network element sends a second request message to the second SMF. The second request message includes information of one or more fourth SMFs.

Here, if the serving communication proxy network element finds one or more first SMFs that satisfy the mobility management network element, the serving communication proxy network element may select one or more fourth SMFs from the one or more first SMFs and send information of the one or more fourth SMFs to the second SMF, so that the second SMF selects one of the one or more fourth SMFs to serve the session.

S560, the second SMF sends a first response message to the serving communication agent network element. Correspondingly, the serving communication agent network element receives the first response message from the second SMF.

Optionally, after performing the operation related to the second request message, the second SMF may send a message that the execution is successful (for example, a message that the session establishment is successful), that is, a first response message, to the mobility management network element. Optionally, in the proxy discovery mode, the second SMF may first send the first response message to the serving communication proxy network element, so that the serving communication proxy network element forwards to the mobility management network element. The serving communication proxy network element may obtain information of the fifth SMF in the first response message. The fifth SMF is the SMF that the second SMF selects to serve the session according to the one or more fourth SMF information in the second request message.

Optionally, the first response message includes Uniform Resource Identifier (URI) information of the fifth SMF. The serving communication proxy network element may obtain address information (such as an IP address or a Fully Qualified Domain Name (FQDN) (or called a full domain name)) of the fifth SMF according to the URI information of the fifth SMF, and then determine an SMF corresponding to the session according to the address information of the fifth SMF. For example, the serving communication agent network element compares the address information of the fifth SMF acquired from the first response message with the address information of the SMF in the configuration file obtained in step S540 and selecting one or more first SMFs according to the DNN, and if the address information of the fifth SMF matches the address information of the SMF in the configuration file, the SMF described in the SMF configuration file is the SMF corresponding to the session. The SCP sends the service area information of the fifth SMF in the configuration file to the AMF.

S570, the serving communication agent network element sends the first response message, information of a fifth SMF and information of the second SMF to the mobility management network element, where the fifth SMF is an SMF of the one or more first SMFs. Optionally, the information of the fifth SMF and the information of the second SMF may be carried in a header of the response message or a message body, which is not limited in this embodiment.

Optionally, the information of the fifth SMF includes at least service area information of the fifth SMF. Optionally, the information of the fifth SMF may further include identification information of the fifth SMF, such as an SMF instance identification.

Optionally, the first response message includes URI information of a fifth SMF, where the URI information of the fifth SMF is used by the mobility management network element to determine information of the fifth SMF. For example, the mobility management network element may obtain the service area information of the fifth SMF according to the URI information.

For example, the mobility management network element may send a request message to the serving communication proxy network element, and send the URI information of the fifth SMF or the address information in the URI information of the fifth SMF to the serving communication proxy network element, so that the configuration file of the fifth SMF or the service area information of the fifth SMF may be obtained according to the address information in the URI information of the fifth SMF. Correspondingly, the service communication proxy network element needs to provide a service interface, so that the mobility management network element calls the service interface to acquire the service area information of the fifth SMF. Or, the mobility management network element may obtain the configuration file of the fifth SMF from the NRF according to the address information in the URI information of the fifth SMF, and accordingly, the NRF needs to support the capability of querying the SMF according to the URI of the SMF.

In the embodiments of the present application, unless otherwise specified or conflicting with respect to logic, the terms and/or descriptions in different embodiments have consistency and may be mutually cited, and technical features in different embodiments may be combined to form a new embodiment according to their inherent logic relationship.

The present application also provides for a further method of selecting SMF. Fig. 8 shows a schematic interaction diagram of a method 1200 of selecting SMFs according to yet another embodiment of the present application. In the method 1200, the serving communication agent network element may select the first SMF and the second SMF directly according to parameters specified by the mobility management network element. When the embodiment corresponds to the home routing mode, the first SMF is H-SMF, and the second SMF corresponds to V-SMF. The method at the serving communication proxy network element side is performed by a proxy network element (such as an SCP) or a chip (or module) in the serving communication proxy network element, and the method at the mobility management network element side may be performed by a mobility management network element (such as an AMF) or a chip (or module) in the mobility management network element. As shown in fig. 8, the method 1200 includes:

s1210, the mobility management network element sends a first message to the serving communication agent network element. Correspondingly, the service communication proxy network element receives the first message.

S1220, the serving communication agent network element obtains the first parameter information and the second parameter information according to the first message.

In this embodiment, the mobility management network element classifies the parameters of selecting the first SMF and selecting the second SMF in the first message, so that the SCP can directly select the first SMF according to the parameters of selecting the first SMF and directly select the second SMF according to the parameters of selecting the second SMF. For example, the first parameter information is used to select a first SMF and the second parameter information is used to select a second SMF. The serving communication agent network element may directly select based on both sets of parameters. Thus, the serving communication agent network element does not need the judgment logic as in the method 500 in order to determine whether the SMFs satisfying all the parameters at the same time need to be selected, and if the first SMF and the second SMF do not exist, the logic of the serving communication agent is simplified, so that the serving communication agent does not need to understand the service-related logic.

In this embodiment, the mobility management network element specifies that the serving communication agent network element selects the first SMF and the second SMF, and specifies that the parameters of the first SMF are selected, and that the parameters of the second SMF are selected.

For a home routing scenario, the first SMF is an H-SMF, and the first parameter information includes: network element type indication, HPLMNID and DNN information, and the like, the second SMF is a V-SMF, and the second parameter information includes: network element type indication, location information of optional UEs, etc.

If the first SMF is an SMF, the first parameter information includes: network element type indication, DNN information, and the like, the second SMF is an I-SMF, and the second parameter information includes: network element type indication, location information of the UE, and the like.

Further, optionally, the mobility management network element indicates which set of parameters is used for selecting the second SMF (i.e. the target SMF for which the serving communication proxy network element sent the second request message) or which set of parameters is used for selecting the first SMF. In this way, the serving communication agent network element may place the selected first SMF in the first request message to generate a second request message based on the indication, and send the second request message to the second SMF.

Optionally, in an implementation, the mobility management network element may use a network element type to indicate which set of parameters is used to select the second SMF or which set of parameters is used to select the first SMF, for example, in a home and rural routing scenario, when the network element type indication is used to indicate that the serving communication proxy network element selects V-SMF or I-SMF, the set of parameters is used to select the second SMF, and when the network element type is used to indicate that the serving communication proxy network element selects H-SMF or SMF, the set of parameters is used to select the first SMF.

It should be noted that, optionally, before requesting the serving communication agent network element to select the first SMF and the second SMF, the mobility management network element determines whether the second SMF needs to be selected. In an implementation manner, before triggering the present procedure, a mobility management network element first requests a serving communication agent network element to select an SMF that supports both the location information of the UE and the DNN, and if the SMF that supports both the location information of the UE and the DNN does not exist, the mobility management network element determines that it is necessary to select the first SMF and the second SMF. Specifically, the mobility management network element sends an xth message to the serving communication agent network element, where the xth message includes a yth parameter, and the yth parameter includes: the method comprises the steps that a network element type (the network element type is SMF), UE position information and DNN, if the SCP determines that the SMF which supports the position information of the UE and the DNN at the same time does not exist, the SCP sends a rejection message to a mobility management network element to indicate that the mobility management network element cannot select the SMF which supports the position information of the UE and the DNN at the same time.

S1230, the serving communication agent network element selects the first SMF and the second SMF.

Here, the serving communication agent network element selects one or more first SMFs directly according to the first parameter information and selects second SMFs according to the second parameter information.

Optionally, the method 1200 further comprises:

and the service communication agent network element generates a second request message according to the first message and the one or more first SMFs, wherein the second request message comprises the information of one or more fourth SMFs in the information of the selected one or more first SMFs.

Here, the serving communication proxy network element may fill the information of one or more fourth SMFs in the information of one or more first SMFs into the first request message, and generate the second request message, that is, a message body of the first request message sent by the mobility management network element needs to be modified by the serving communication proxy network element. For example, when the first request message sent by the mobility management element is an Nsmf _ pdusesion _ CreateSMContext request, the serving communication agent element inserts information of one or more fourth SMFs of the one or more first SMFs into a message body of the message, so that the second SMF can select, according to the information of the one or more fourth SMFs of the one or more first SMFs, one fifth SMF from the one or more fourth SMFs to send a message, and complete session establishment.

Or, optionally, the serving communication proxy network element may not modify the message body of the first request message, but add information of one or more fourth SMFs in the one or more first SMFs to the message header of the first request message to obtain the second request message, that is, information of the one or more fourth SMFs in the one or more first SMFs is carried in the message header of the second request message. Thus, the second SMF needs to additionally read the header of the second request message when processing the session, so as to obtain information of the fifth SMF (the fifth SMF is an SMF of one or more fourth SMFs of the one or more first SMFs).

S1240, the serving communication agent network element sends a second request message to the second SMF. The second request message includes information of one or more fourth SMFs of the one or more first SMFs.

Here, the second SMF may select one of the one or more fourth SMFs among the one or more first SMFs to serve the session.

S1250, the second SMF sends a first response message to the serving communication agent network element. Correspondingly, the serving communication agent network element receives the first response message from the second SMF.

Optionally, after performing the operation related to the second request message, the second SMF may send a message that the execution is successful (for example, a message that the session establishment is successful), that is, a first response message, to the mobility management network element.

In one implementation, the second SMF sends information of the second SMF to the mobility management network element in the first response message, and the first response message further includes information of the fifth SMF.

Optionally, the information of the second SMF includes service area information of the second SMF. Optionally, the information of the second SMF may further include identification information of the second SMF, such as an I-SMF instance identification.

Optionally, the information of the fifth SMF includes service area information of the fifth SMF. Optionally, the information of the fifth SMF may further include identification information of the fifth SMF, such as an SMF instance identification.

If the information of the second SMF and the fifth SMF is the identifier of the SMF (such as an example identifier or URI information), the mobility management network element may obtain the service area information of the SMF according to the identifier information of the SMF.

In another implementation, after receiving the first response message, the serving communication proxy network element sends the area information of the second SMF and the fifth SMF to the mobility management network element. The serving communication proxy network element may obtain address information (such as an IP address or a Fully Qualified Domain Name (FQDN) (or called a full domain name)) of the fifth SMF according to the URI information of the fifth SMF in the first response message, and then determine an SMF corresponding to the session according to the address information of the fifth SMF. For example, the serving communication agent network element compares the address information of the fifth SMF acquired from the first response message with the address information of the SMF in the configuration file obtained in step S540 and selecting one or more first SMFs according to the DNN, and if the address information of the fifth SMF matches the address information of the SMF in the configuration file, the SMF described in the SMF configuration file is the SMF corresponding to the session. The SCP sends the service area information of the fifth SMF in the configuration file to the AMF.

Or, in another implementation manner, after receiving the first response message, the serving communication proxy network element sends the information of the second SMF to the mobility management network element. The information of the fifth SMF is included by the second SMF in the first response message. The information of the second SMF and the fifth SMF may be an identifier of the SMF, and the mobility management network element may obtain the service area information of the SMF according to the identifier information of the SMF.

S1260, the serving communication agent network element sends the first response message to the mobility management network element.

Optionally, the serving communication agent network element may send the information of the second SMF and the information of the fifth SMF to the mobility management network element.

The method of selecting SMF is described above, and an apparatus for selecting SMF according to an embodiment of the present application will be described below. It should be understood that the technical features described in the method embodiments are equally applicable to the following apparatus embodiments.

Fig. 9 shows a possible exemplary block diagram of an apparatus involved in the embodiment of the present application, where the apparatus 800 may exist in the form of software, or may be a serving communication proxy network element, or may be a chip in the serving communication proxy network element. The apparatus 800 comprises: a transceiver module 810 and a processing module 820, the transceiver module 810 may include a receiving unit and a transmitting unit. The processing module 820 is used for controlling and managing the actions of the apparatus 800. The transceiver module 810 is used for supporting communication between the apparatus 800 and other network entities (e.g., session control function entity, etc.). Optionally, the apparatus 800 may further comprise a storage unit for storing program codes and data of the apparatus 800.

Alternatively, the modules in the apparatus 800 may be implemented by software.

Alternatively, the processing module 820 may be a processor or a controller, such as a general purpose Central Processing Unit (CPU), a general purpose processor, a Digital Signal Processing (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure of the embodiments of the application. The processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, DSPs, and microprocessors, among others. The transceiver module 810 may be a communication interface, a transceiver circuit, or the like, wherein the communication interface is referred to as a generic term, and in a specific implementation, the communication interface may include a plurality of interfaces, which may include, for example: an interface between a serving communication proxy network element and a CSCF network element, and/or other interfaces. The storage unit may be a memory.

The processing module 820 may support the apparatus 800 to perform the actions of the serving communication agent network element in the above method examples, e.g. may support the apparatus 800 to perform steps 220,230 in fig. 2, steps 260,270 in fig. 3, steps 320,330 in fig. 4, step 320,330,380,390 in fig. 5, step 420,450,460 in fig. 6, steps 520,530,540 in fig. 7.

The transceiver module 810 may support communication between the apparatus 800 and a mobility management network element, SMF (such as V-SMF or I-SMF), for example, the transceiver module 810 may support the apparatus 800 to perform steps 210 and 240 in fig. 2, steps 250 and 280 in fig. 3, steps 310, 340, 350 and 360 in fig. 4, steps 370, 391 and 392 in fig. 5, and steps 410, 430, 440, 470 in fig. 6. For example, the following may be used:

in a first implementation, the apparatus 800 includes:

a transceiver module 810 for receiving a first message from a mobility management network element;

a processing module 820, configured to obtain first parameter information according to the first message, where the first message is used to request the serving communication agent network element to select an SMF according to the first parameter information, and the first parameter information includes location information of a user equipment UE and a data network name DNN;

the processing module 820 is further configured to determine whether there is an SMF that satisfies the first parameter information; and in the absence of the SMF satisfying the first parameter information, selecting one or more first SMFs supporting the DNN, and invoking the transceiver module 810 to send a rejection message to the mobility management network element, where the rejection message includes information of the one or more first SMFs.

In one possible implementation manner, the transceiver module 810 is further configured to:

receiving a second message from the mobility management network element;

the processing module 820 is further configured to obtain second parameter information according to the second message, where the second parameter information includes location information of the UE;

the processing module 820 is further configured to select the second SMF based on the second parameter information;

the processing module 820 is further configured to obtain a second request message according to the second message, and invoke the transceiver module 810 to send the second request message to the second SMF.

In one possible implementation manner, the transceiver module 810 is further configured to: and sending the information of the second SMF to the mobility management network element.

In a possible implementation manner, the processing module 820 is configured to select one or more first SMFs supporting the DNN and invoke the transceiver module 810 to send a reject message to the mobility management network element, where the selecting step includes:

the first parameter information further includes target network element type indication information, and if the target network element type indication information is used to indicate that the serving communication agent network element selects an SMF, under the condition that it is determined that there is no SMF that satisfies the first parameter information, one or more first SMFs that support the DNN are selected, and the transceiver module 810 is invoked to send information of the one or more first SMFs to the mobility management network element.

In a possible implementation manner, the transceiver module 810 is further configured to receive first indication information from the mobility management network element, where the first indication information is used to indicate: the apparatus selects one or more first SMFs supporting the DNN and sends information of the one or more first SMFs to the mobility management network element, in a case where it is determined that there is no SMF satisfying the first parameter information.

In a possible implementation manner, the processing module 820 is configured to select one or more first SMFs that support the DNN if there is no SMF that satisfies the first parameter information, and specifically includes:

in the absence of SMFs that satisfy the first parameter information, selecting one or more H-SMFs that support the HPLMN ID and the DNN.

It should be understood that the apparatus 800 according to the embodiment of the present application may correspond to the method for serving a communication proxy network element in the foregoing method embodiment, for example, the method in fig. 2 or fig. 3, and the above and other management operations and/or functions of each module in the apparatus 800 are respectively for implementing corresponding steps of the method for serving a communication proxy network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, are not described herein again.

In a second implementation, the apparatus 800 includes:

a processing module 820, configured to obtain first parameter information according to the first message, where the first message is used to request the serving communication agent network element to select an SMF according to the first parameter information, and obtain a first request message according to the first message, and send the first request message to the SMF, where the first parameter information includes location information of a user equipment UE and a data network name DNN;

the processing module 820 is further configured to determine whether there is an SMF that satisfies the first parameter information;

in the absence of an SMF that satisfies the first parameter information, the processing module 820 is further configured to invoke the transceiver module 810 to send a rejection message to the mobility management element, where the rejection message is used to indicate that there is no SMF that satisfies the first parameter information;

the transceiver module 810 is further configured to receive second parameter information from the mobility management network element, where the second parameter information includes the DNN;

the processing module 820 is further configured to select one or more first SMFs supporting the second parameter information, and invoke the transceiver module 810 to send a first response message to a mobility management network element, where the first response message includes information of the one or more first SMFs.

In a possible implementation manner, the transceiver module 810 is further configured to receive a second message from the mobility management network element;

the processing module 820 is further configured to obtain third parameter information according to the second message, where the third parameter information includes location information of the UE; selecting the second SMF according to the third parameter information; and acquiring a second request message according to the second message, and calling the transceiver module 810 to send the second request message to the second SMF.

In a possible implementation manner, the transceiver module 810 is further configured to send the information of the second SMF to the mobility management network element.

In a possible implementation manner, the processing module 820 is configured to select one or more first SMFs that support the DNN, and send a first response message to a mobility management network element, and specifically includes:

In a possible implementation manner, the processing module 820 is configured to select one or more first SMFs supporting the DNN, and invoke the transceiver module 810 to send a first response message to a mobility management network element, and specifically includes:

the second parameter information further includes first target network element type indication information, and if the first target network element type indication information is used to indicate an SMF, the processing module 820 selects one or more first SMFs that support the DNN, and sends the first response message to the mobility management network element.

Optionally, the selecting, by the serving communication agent network element, the second SMF based on the third parameter information includes:

It should be understood that the apparatus 800 according to the embodiment of the present application may correspond to the method for serving a communication proxy network element in the foregoing method embodiment, for example, the method in fig. 4 or fig. 5, and the above and other management operations and/or functions of each module in the apparatus 800 are respectively for implementing corresponding steps of the method for serving a communication proxy network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, are not described herein again.

In a third implementation, the apparatus 800 includes:

a transceiver module 810 that receives a first message from a mobility management network element;

a processing module 820, configured to obtain first parameter information according to the first message, where the first message is used to request the serving communication agent network element to discover an H-SMF according to the first parameter information, and the first parameter information includes an identifier HPLMN ID and a data network name DNN of a home public land mobile network;

the processing module 820 is further configured to select one or more H-SMFs that satisfy the first parameter information, and invoke the transceiver module 810 to send a first response message to the mobility management network element, where the first response message includes information of the one or more H-SMFs.

the processing module 820 is further configured to obtain second parameter information according to the second message, where the second parameter information includes location information of the UE; selecting V-SMF according to the second parameter information; and acquiring a second request message according to the second message, and calling the transceiver module 810 to send the second request message to the V-SMF.

In a possible implementation manner, the transceiver module 810 is further configured to send the information of the V-SMF to the mobility management network element.

In a possible implementation manner, the transceiver module 810 is further configured to receive first indication information from the mobility management element, where the first parameter information further includes first indication information, and the first indication information is used to indicate that the serving communication agent network element replies a response message to the mobility management element after discovering the H-SMF.

In a possible implementation manner, the processing module 820 is configured to select one or more H-SMFs that satisfy the first parameter information, and invoke the transceiver module 810 to send a first response message to the mobility management network element, where the method specifically includes:

the first parameter information further includes first target network element type indication information, and if the first target network element type indication information is used to indicate an H-SMF or an SMF, one or more H-SMFs supporting the HPLMN ID and the DNN are selected, and the transceiver module 810 is invoked to send the first response message to the mobility management network element.

In a possible implementation manner, the processing module 820 is configured to select, based on the second parameter information, a V-SMF that supports location information of the UE, and specifically includes:

It should be understood that the apparatus 800 according to the embodiment of the present application may correspond to the method for serving the communication proxy network element in the foregoing method embodiment, for example, the method in fig. 6, and the above and other management operations and/or functions of each module in the apparatus 800 are respectively for implementing corresponding steps of the method for serving the communication proxy network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no repeated description is provided here.

In a fourth implementation, the apparatus 800 includes:

a processing module 820, configured to obtain first parameter information according to the first message, where the first parameter information includes location information of a user equipment UE and a data network name DNN;

the processing module 820 is further configured to determine whether there is an SMF that satisfies the first parameter information; and under the condition that the SMF meeting the first parameter information does not exist, selecting one or more first SMFs according to the DNN, and selecting a second SMF according to the position information of the UE.

In one possible implementation, the method further includes:

the processing module 820 is further configured to generate a second request message according to the first message and the one or more first SMFs, where the second request message includes information of one or more fourth SMFs;

the transceiver module 810 is further configured to send a second request message to the second SMF;

in a possible implementation manner, the transceiver module 810 is further configured to send, to the mobility management network element, information of a fifth SMF and information of the second SMF, where the fifth SMF is an SMF selected by the second SMF among the one or more fourth SMFs.

In a possible implementation manner, the transceiver module 810 is further configured to receive a first response message from the second SMF, where the first response message includes URI information of the fifth SMF;

the transceiver module 810 is configured to send the information of the fifth SMF to the mobility management network element, and specifically includes: acquiring information of a fifth SMF according to URI information of the fifth SMF in the first response message; and sending the information of the fifth SMF to the mobility management network element.

Optionally, the information of the fifth SMF is included in a header of the second request message or in a message body of the second request message.

Optionally, the first SMF is an SMF and the second SMF is an I-SMF;

alternatively, the first SMF is H-SMF and the second SMF is V-SMF.

It should be understood that the apparatus 800 according to the embodiment of the present application may correspond to the method for serving the communication proxy network element in the foregoing method embodiment, for example, the method in fig. 7, and the above and other management operations and/or functions of each module in the apparatus 800 are respectively for implementing corresponding steps of the method for serving the communication proxy network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no repeated description is provided here.

In a sixth implementation, the apparatus 800 includes:

a processing module 820, configured to obtain first parameter information according to the first message, where the first message is used to request the serving communication agent network element to discover a session management network element according to the first parameter information, and the first parameter information includes a data network name DNN;

the processing module 820 is further configured to select one or more session management network elements that satisfy the first parameter information, and invoke the transceiver module 810 to send a first response message to the mobility management network element, where the first response message includes information of the one or more session management network elements.

In one possible implementation manner, the transceiver module 810 is further configured to: receiving a second message from the mobility management network element;

the processing module 820 is further configured to obtain second parameter information according to the second message, where the second parameter information includes location information of the UE; selecting an intermediate session management network element according to the second parameter information; and acquiring a second request message according to the second message, and sending the second request message to the intermediate session management network element.

In one possible implementation manner, the transceiver module 810 is further configured to: and sending the information of the intermediate session management network element to the mobility management network element.

In one possible implementation manner, the transceiver module 810 is further configured to: receiving first indication information from the mobility management network element, where the first parameter information further includes the first indication information, and the first indication information is used to indicate that the serving communication agent network element replies a response message to the mobility management network element after discovering the session management network element.

In a possible implementation manner, the processing module 820 is configured to select one or more session management network elements that satisfy the first parameter information, and invoke the transceiver module 810 to send a first response message to the mobility management network element, and specifically includes:

In a possible implementation manner, the transceiver module 810 is configured to select, based on the second parameter information, an intermediate session management network element that supports location information of the UE, and specifically includes:

the second parameter information further includes second target network element type indication information, where the second target network element type indication information is used to indicate that the serving communication agent network element selects an inter-session management network element I-SMF or a visited session management network element V-SMF, and then the serving communication agent network element selects an inter-session management network element I-SMF or a visited session management network element V-SMF that supports the location information of the UE.

Optionally, the first parameter information further comprises an identification HPLMN ID of a home public land mobile network.

In a sixth implementation, the apparatus 800 includes:

a processing module 820, configured to obtain first parameter information and second parameter information according to the first message, where the first parameter information is used to select a first SMF, and the second parameter information is used to select a second SMF;

the processing module 820 is further configured to select one or more first SMFs according to the first parameter information, and select a second SMF according to the second parameter information. Therefore, the serving communication agent network element may determine that the first SMF and the second SMF need to be selected simultaneously according to the first parameter information and the second parameter information, thereby simplifying the logic of the serving communication agent so that the serving communication agent does not need to understand the service-related logic.

In a possible implementation manner, the processing module 820 is further configured to generate a second request message according to the first message and the one or more first SMFs, where the second request message includes information of one or more fourth SMFs in the one or more first SMFs; the transceiver module 810 is further configured to send a second request message to the second SMF.

In a possible implementation manner, the first message includes indication information, where the indication information is used to indicate that a serving communication agent includes information of the first SMF in the second request message, or the indication information is used to indicate that the serving communication agent network element sends the second request message to the second SMF.

In one possible implementation, the method further includes: the indication information is included in first parameter information, where the indication information is a first network element type indication, and the first network element type indication is used to indicate that the serving communication agent network element selects H-SMF or SMF, and then the serving communication agent network element determines that the second request message includes information of the first SMF; or, the indication information is included in second parameter information, where the indication information is a second network element type indication, and the second network element type indication is used to indicate that the serving communication agent network element selects V-SMF or I-SMF, and then the serving communication agent network element determines to send the second request message to the second SMF.

In a possible implementation manner, the transceiver module is further configured to receive a first response message from the second SMF, where the first response message includes URI information of the fifth SMF; wherein the transceiver module is configured to send the information of the fifth SMF to the mobility management network element, and further includes: acquiring information of a fifth SMF according to URI information of the fifth SMF in the first response message; and sending the information of the fifth SMF to the mobility management network element.

It should be understood that the apparatus 800 according to the embodiment of the present application may correspond to the method for serving the communication proxy network element in the foregoing method embodiment, for example, the method in fig. 8, and the above and other management operations and/or functions of each module in the apparatus 800 are respectively for implementing corresponding steps of the method for serving the communication proxy network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no repeated description is provided here.

When the processing module 820 in the embodiment of the present application is a processor and the transceiver module 810 is a transceiver, the apparatus 800 according to the embodiment of the present application may be the apparatus 900 shown in fig. 10.

Fig. 10 is a schematic block diagram of an apparatus 900 for selecting a session management network element according to an embodiment of the present application. As shown in fig. 10, the apparatus 900 includes: a processor 901.

In one possible implementation, the processor 901 is configured to invoke an interface to perform the following actions: receiving a first message from a mobility management network element; the processor 901 is configured to: acquiring first parameter information according to the first message, wherein the first message is used for requesting the service communication agent network element to select an SMF according to the first parameter information, acquiring a first request message according to the first message, and sending the first request message to the SMF, and the first parameter information comprises the position information of User Equipment (UE) and a Data Network Name (DNN); further for determining whether there is an SMF that satisfies the first parameter information; and in the absence of the SMF satisfying the first parameter information, selecting one or more first SMFs supporting the DNN, and invoking the transceiver module to send a rejection message to the mobility management network element, where the rejection message includes information of the one or more first SMFs.

It should be understood that the processor 901 may invoke an interface to perform the above transceiving actions, wherein the invoked interface may be a logical interface or a physical interface, which is not limited thereto. Alternatively, the physical interface may be implemented by a transceiver. Optionally, the apparatus 900 further comprises a transceiver 903.

Optionally, the apparatus 900 further includes a memory 902, and the memory 902 may store the program codes in the above method embodiments, so as to be called by the processor 901.

Specifically, if the apparatus 900 includes a processor 901, a memory 902 and a transceiver 903, the processor 901, the memory 902 and the transceiver 903 communicate with each other through an internal connection path to transmit control and/or data signals. In one possible design, the processor 901, the memory 902, and the transceiver 903 may be implemented by chips, and the processor 901, the memory 902, and the transceiver 903 may be implemented in the same chip, or may be implemented in different chips, or any two functions may be implemented in one chip. The memory 902 may store program code, which the processor 901 calls to implement the corresponding functions of the apparatus 900 stored by the memory 902.

It should be understood that the apparatus 900 may also be configured to perform other steps and/or operations on the network element side of the serving communication agent in the foregoing embodiments, and details are not described herein for brevity.

Fig. 11 shows a possible exemplary block diagram of another apparatus involved in the embodiment of the present application, where the apparatus 1000 may exist in the form of software, or may be a mobility management network element, or may be a chip in the mobility management network element. The apparatus 1000 comprises: a transmitting module 1010 and a receiving module 1020, the transmitting module 1010 may include a receiving unit and a transmitting unit. The receiving module 1020 is used for controlling and managing the operation of the apparatus 1000. The sending module 1010 is configured to support communication between the apparatus 1000 and other network entities (e.g., a session control function entity, etc.). Optionally, the apparatus 1000 may further comprise a storage unit for storing program codes and data of the apparatus 1000.

Alternatively, the modules in the apparatus 1000 may be implemented by software.

Alternatively, the receiving module 1020 may be a processor or a controller, such as a general purpose Central Processing Unit (CPU), a general purpose processor, a Digital Signal Processing (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure of the embodiments of the application. The processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, DSPs, and microprocessors, among others. The sending module 1010 may be a communication interface, a transceiver circuit, or the like, wherein the communication interface is generally referred to, and in a specific implementation, the communication interface may include a plurality of interfaces, which may include, for example: an interface between a mobility management network element and a CSCF network element, and/or other interfaces. The storage unit may be a memory.

The receiving module 1020 may support the apparatus 1000 to perform the actions of the mobility management network element in the above method examples, for example, may support the apparatus 1000 to perform step 240 in fig. 2, steps 240 and 280 in fig. 3, steps 340 and 360 in fig. 4, step 340,360,392 in fig. 5, step 430 in fig. 6, and step 570 in fig. 7.

The sending module 1010 may support communication between the apparatus 1000 and a mobility management network element, SMF (such as V-SMF or I-SMF), for example, the sending module 1010 may support the apparatus 1000 to perform step 210 in fig. 2, steps 210,250 in fig. 3, steps 310,350 in fig. 4, steps 310,350, 370 in fig. 5, steps 410, 440 in fig. 6, step 510 in fig. 7. For example, the following may be used:

in a first implementation, the apparatus 1000 includes:

a sending module 1010, configured to send a first message to a serving communication agent network element, where the first message includes first parameter information, and the first message is used to request the serving communication agent network element to select an SMF according to the first parameter information, and obtain a first request message according to the first request message, and send the first request message to the SMF, where the first parameter information includes location information of a user equipment UE and a data network name DNN;

a receiving module 1020, configured to receive a rejection message from the serving communication agent network element, where the rejection message includes information of one or more first SMFs supporting the DNN selected by the serving communication agent.

In a possible implementation manner, the sending module 1010 is further configured to:

and sending a second message to the serving communication agent network element, where the second message includes second parameter information and one or more third SMFs in the one or more first SMFs, the second parameter information is used to discover a second SMF, the second parameter information includes location information of the UE, and the one or more third SMFs are used to send to the second SMF.

In a possible implementation manner, the receiving module 1020 is further configured to:

receiving information of the second SMF from the serving communication agent network element.

Optionally, the first parameter information further includes target network element type indication information, where the target network element type indication information is used to indicate the serving communication agent network element to select the SMF.

sending first indication information to the serving communication agent network element, where the first indication information is used to indicate: and the serving communication agent network element selects one or more first SMFs supporting the DNN under the condition that the serving communication agent network element determines that the SMFs meeting the first parameter information do not exist, and sends the information of the one or more first SMFs to the mobility management network element.

It should be understood that the apparatus 1000 according to the embodiment of the present application may correspond to the method for mobility managing a network element in the foregoing method embodiment, for example, the method in fig. 2 or fig. 3, and the above and other management operations and/or functions of each module in the apparatus 1000 are respectively for implementing corresponding steps of the method for mobility managing a network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no repeated description is provided here.

In a second implementation, the apparatus 1000 includes:

a receiving module 1020, configured to receive a rejection message from the serving communication agent network element, where the rejection message is used to indicate that there is no SMF that satisfies the first parameter information;

the sending module 1010 is further configured to send second parameter information to the serving communication agent network element, where the second parameter information includes the DNN;

the receiving module 1020 is further configured to receive a first response message from the serving communication agent network element, where the first response message includes information of the one or more first SMFs.

and sending a second message to the serving communication agent network element, wherein the second message comprises third parameter information, the third parameter information comprises the position information of the UE, and the third parameter information is used for selecting a second SMF.

It should be understood that the apparatus 1000 according to the embodiment of the present application may correspond to the method for mobility managing a network element in the foregoing method embodiment, for example, the method in fig. 4 or fig. 5, and the above and other management operations and/or functions of each module in the apparatus 1000 are respectively for implementing corresponding steps of the method for mobility managing a network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no repeated description is provided here.

In a third implementation, the apparatus 1000 includes:

a sending module 1010, configured to send a first message to a serving communication agent network element, where the first message includes first parameter information, the first message is used to request the serving communication agent network element to discover an H-SMF according to the first parameter information, and the first parameter information includes an identifier HPLMN ID and a data network name DNN of a home public land mobile network;

a receiving module 1020, configured to receive a first response message from the serving communication agent network element, where the first response message includes information of the one or more H-SMFs.

In a possible implementation manner, the sending module 1010 is further configured to: and sending a second message to the serving communication agent network element, wherein the second message comprises second parameter information, the second parameter information is used for discovering the V-SMF, and the second parameter information comprises the position information of the UE.

In a possible implementation manner, the receiving module 1020 is further configured to: receiving information of the V-SMF from the serving communication agent network element.

Optionally, the first parameter information further includes first indication information, where the first indication information is used to indicate that the serving communication agent network element replies a response message to the mobility management network element after discovering the H-SMF.

It should be understood that the apparatus 1000 according to the embodiment of the present application may correspond to the method for mobility managing a network element in the foregoing method embodiment, for example, the method in fig. 6, and the above and other management operations and/or functions of each module in the apparatus 1000 are respectively for implementing corresponding steps of the method for mobility managing a network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no detailed description is provided here.

In a fourth implementation, the apparatus 1000 includes:

a sending module 1010, configured to send a first message to a serving communication agent network element, where the first message includes first parameter information, and the first parameter information includes location information of a user equipment UE and a data network name DNN;

a receiving module 1020, configured to receive information of a fifth SMF and information of a second SMF from the serving communication proxy network element, where the fifth SMF is an SMF in one or more fourth SMFs in the second request message.

In a possible implementation manner, the receiving module 1020 is configured to receive information of a third SMF and information of a second SMF from the serving communication agent network element, and specifically includes:

receiving a first response message from the serving communication proxy network element, wherein the information of the fifth SMF and the information of the second SMF are included in a header of the first response message or in a message body of the first response message.

It should be understood that the apparatus 1000 according to the embodiment of the present application may correspond to the method for mobility managing a network element in the foregoing method embodiment, for example, the method in fig. 7, and the foregoing and other management operations and/or functions of each module in the apparatus 1000 are respectively for implementing corresponding steps of the method for mobility managing a network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no detailed description is provided here.

In a fifth implementation, the apparatus 1000 includes:

a sending module 1010, configured to send a first message to a serving communication agent network element, where the first message includes first parameter information, and the first message is used to request the serving communication agent network element to discover a session management network element according to the first parameter information, where the first parameter information includes a data network name DNN;

a receiving module 1020, configured to receive a first response message from the serving communication agent network element, where the first response message includes information of the one or more session management network elements.

In a possible implementation manner, the sending module 1010 is further configured to send a second message to the serving communication agent network element, where the second message includes second parameter information, the second parameter information is used to discover an intermediate session management network element, and the second parameter information includes location information of the UE.

In one possible implementation, the apparatus further includes a processing module (not shown in fig. 10), and the processing module is further configured to:

before sending the second message to the serving communication agent network element, determining whether a session management network element supporting the location information of the UE exists according to the information of the session management network element, and if the session management network element supporting the location information of the UE does not exist, determining that an intermediate session management network element needs to be selected.

In a possible implementation manner, the receiving module 1020 is further configured to receive information of the intermediate session management network element from the serving communication agent network element.

In a possible implementation manner, the first parameter information further includes first indication information, where the first indication information is used to indicate that the serving communication agent network element replies a response message to the mobility management network element after discovering the home session management network element or the session management network element.

In a possible implementation manner, the first parameter information further includes first target network element type indication information, where the first target network element type indication information is used to indicate a home session management network element or a session management network element, and is used to indicate that the serving communication agent network element replies a response message to the mobility management network element after discovering the home session management network element or the session management network element.

In a possible implementation manner, the second parameter information further includes second target network element type indication information, where the second target network element type indication information is used to indicate that the serving communication agent network element selects a visited session management network element.

In a sixth implementation, the apparatus 1000 includes:

a sending module 1010, configured to send a first message, where the first message includes first parameter information and second parameter information, the first parameter information is used to select a first SMF, and the second parameter information is used to select a second SMF;

a receiving module 1020, configured to receive information of the fifth SMF and information of the second SMF from the serving communication proxy network element. Therefore, the mobility management network element may obtain the two SMFs determined by the serving communication agent network element, so that when the mobility management network element operates in the agent discovery mode, the creation of a session including the two SMFs is still supported, and thus, the application scenario in which the mobility management network element operates in the agent discovery mode is not limited.

In a possible implementation manner, the receiving module is configured to receive information of a fifth SMF and information of a second SMF from the serving communication agent network element, and specifically includes: receiving a first response message from the serving communication proxy network element, wherein the information of the fifth SMF and the information of the second SMF are included in a header of the first response message or in a message body of the first response message.

It should be understood that the apparatus 1000 according to the embodiment of the present application may correspond to the method for mobility managing a network element in the foregoing method embodiment, for example, the method in fig. 8, and the above and other management operations and/or functions of each module in the apparatus 1000 are respectively for implementing corresponding steps of the method for mobility managing a network element in the foregoing method embodiment, so that beneficial effects in the foregoing method embodiment may also be implemented, and for brevity, no detailed description is provided here.

When the receiving module 1020 and the transmitting module 1010 in the embodiment of the present application are transceivers, the apparatus 1000 according to the embodiment of the present application may be the apparatus 1100 shown in fig. 12.

Fig. 12 is a schematic block diagram of an apparatus 1100 for selecting a session management network element according to an embodiment of the present application. As shown in fig. 12, the apparatus 1100 includes: a processor 1101.

In one possible implementation, the processor 1101 is configured to invoke an interface to perform the following actions: sending a first message to a serving communication agent network element, wherein the first message comprises first parameter information, the first message is used for requesting the serving communication agent network element to select an SMF (short message service) according to the first parameter information, acquiring a first request message according to the first request message, and sending the first request message to the SMF, and the first parameter information comprises location information and a data network name DNN (network name network) of User Equipment (UE); receiving a reject message from the serving communication agent network element, wherein the reject message includes information of the one or more first SMFs supporting the DNN selected by the serving communication agent.

It should be understood that the processor 1101 may invoke an interface to perform the transceiving action, wherein the invoked interface may be a logical interface or a physical interface, which is not limited thereto. Alternatively, the physical interface may be implemented by a transceiver. Optionally, the apparatus 1100 further comprises a transceiver 1103.

Optionally, the apparatus 1100 further comprises a memory 1102, and the memory 1102 may store the program codes in the above method embodiments, so as to be called by the processor 1101.

Specifically, if the apparatus 1100 includes the processor 1101, the memory 1102 and the transceiver 1103, the processor 1101, the memory 1102 and the transceiver 1103 communicate with each other to transmit control and/or data signals through the internal connection path. In one possible design, the processor 1101, the memory 1102 and the transceiver 1103 may be implemented by chips, and the processor 1101, the memory 1102 and the transceiver 1103 may be implemented in the same chip, or may be implemented in different chips, or any two of the functions may be implemented in one chip. The memory 1102 may store program code, which the processor 1101 calls to the memory 1102 to implement the corresponding functions of the apparatus 1100.

It should be understood that the apparatus 1100 may also be configured to perform other steps and/or operations on the mobility management element side in the foregoing embodiments, and details are not described herein for brevity.

The method disclosed in the embodiments of the present application may be applied to a processor, or may be implemented by a processor. The processor may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The processor may be a general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, a system on chip (SoC), a Central Processing Unit (CPU), a Network Processor (NP), a Digital Signal Processor (DSP), a Microcontroller (MCU), a programmable logic controller (PLD), or other integrated chip. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will 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 RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should be understood that, in the embodiment of the present application, the numbers "first" and "second" … are only used for distinguishing different objects, such as for distinguishing different parameter information or messages, and do not limit the scope of the embodiment of the present application, and the embodiment of the present application is not limited thereto.

It should also be understood that, in the various embodiments of the present application, the size of the serial number of each process described above does not mean the execution sequence, and the execution sequence of each process should be determined by the function and the inherent logic of each process. The various numbers or serial numbers involved in the above processes are merely used for convenience of description and should not be construed as limiting the implementation processes of the embodiments of the present application in any way.

It should also be understood that the term "and/or" herein is merely one type of association 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. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

Items appearing in this application as similar to "include one or more of the following: the meaning of the expressions A, B, and C "generally means that the item may be any of the following, unless otherwise specified: a; b; c; a and B; a and C; b and C; a, B and C; a and A; a, A and A; a, A and B; a, A and C, A, B and B; a, C and C; b and B, B, B and C, C and C; c, C and C, and other combinations of A, B and C. The above description is made by taking 3 elements of a, B and C as examples of optional items of the item, and when the expression "item" includes at least one of the following: a, B, … …, and X ", i.e., more elements in the expression, then the items to which the item may apply may also be obtained according to the aforementioned rules.

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 communication connection may be an indirect coupling or communication connection through some interfaces, 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 U 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 method of selecting a session management network element, comprising:

the serving communication agent network element receiving a first message from the mobility management network element;

the service communication agent network element acquires first parameter information according to the first message, wherein the first parameter information comprises position information of User Equipment (UE) and a Data Network Name (DNN);

the service communication agent network element determines whether a session management network element meeting the first parameter information exists;

and under the condition that the session management network element meeting the first parameter information does not exist, the serving communication agent network element selects one or more first session management network elements supporting the DNN, and sends a rejection message to the mobility management network element, wherein the rejection message comprises the information of the one or more first session management network elements.

2. The method of claim 1, wherein the first message is used to request the serving communication proxy network element to select a session management network element according to the first parameter information.

3. The method according to claim 1 or 2, characterized in that the method further comprises:

the serving communication agent network element selects a second session management network element based on the second parameter information;

and the service communication agent network element acquires a second request message according to the second message and sends the second request message to the second session management network element.

4. The method of claim 3, further comprising:

and the service communication agent network element sends the information of the second session management network element to the mobility management network element.

5. The method of claim 1, 2 or 4, wherein in case there is no session management network element satisfying the first parameter information, the serving communication agent network element selecting one or more first session management network elements supporting the DNN and sending a reject message to the mobility management network element, comprises:

the first parameter information further includes target network element type indication information, and if the target network element type indication information is used to indicate that the serving communication proxy network element selects a session management network element, the serving communication proxy network element selects one or more first session management network elements supporting the DNN and sends information of the one or more first session management network elements to the mobility management network element, in a case that it is determined that there is no session management network element that satisfies the first parameter information.

6. The method of claim 1, 2 or 4, further comprising:

the serving communication agent network element receives first indication information from the mobility management network element, where the first indication information is used to indicate: and under the condition that the serving communication agent network element determines that the session management network element meeting the first parameter information does not exist, the serving communication agent network element selects one or more first session management network elements supporting the DNN, and sends the information of the one or more first session management network elements to the mobility management network element.

7. The method according to claim 3, characterized in that said second request message comprises information of said one or more first session managing network elements.

8. The method of claim 3, wherein the second session management network element is a visited session management function session management network element, wherein the first session management network element is a home session management network element, wherein the first parameter information further includes an identity (HPLMN ID) of a home public land mobile network, wherein the first parameter information is used for discovering the home session management network element, and wherein the reject message includes information of one or more home session management network elements.

9. The method of claim 8, wherein in the absence of a session management network element satisfying the first parameter information, the serving communication agent network element selecting one or more first session management network elements supporting the DNN, comprising:

in the absence of a session management network element that satisfies the first parameter information, the serving communication proxy network element selects one or more home session management network elements that support the HPLMN ID and the DNN.

10. The method of claim 3, wherein the second session management network element is an intermediate session management network element.

11. A method of selecting a session management network element, comprising:

a mobility management network element sends a first message to a service communication agent network element, wherein the first message comprises first parameter information, and the first parameter information comprises position information of User Equipment (UE) and a Data Network Name (DNN);

the mobility management network element receives a rejection message from the serving communication agent network element, where the rejection message includes information of one or more first session management network elements supporting the DNN selected by the serving communication agent.

12. The method of claim 11, wherein the first message is used to request the serving communication proxy network element to select a session management network element according to the first parameter information, obtain a first request message according to the first message, and send the first request message to the session management network element.

13. The method according to claim 11 or 12, characterized in that the method further comprises:

the mobility management network element sends a second message to the serving communication agent network element, where the second message includes second parameter information and one or more third session management network elements in the one or more first session management network elements, the second parameter information is used to discover the second session management network element, the second parameter information includes location information of the UE, and the one or more third session management network elements are used to send the second session management network element.

14. The method of claim 13, further comprising:

the mobility management network element receives information of the second session management network element from the serving communication agent network element.

15. The method according to claim 11, 12 or 14, wherein the first parameter information further includes target network element type indication information, and the target network element type indication information is used to instruct the serving communication agent network element to select a session management network element.

16. The method of claim 11, 12 or 14, further comprising:

the mobility management network element sends first indication information to the serving communication agent network element, where the first indication information is used to indicate: and under the condition that the serving communication agent network element determines that the session management network element meeting the first parameter information does not exist, selecting one or more first session management network elements supporting the DNN, and sending the information of the one or more first session management network elements to the mobility management network element.

17. The method of claim 13, wherein the second session management network element is a visited session management network element, wherein the one or more first session management network elements are one or more home session management network elements, wherein the first parameter information further includes an identity HPLMN ID of a home public land mobile network, wherein the first parameter information is used for discovering a home session management function home session management network element, and wherein the reject message includes information of the one or more home session management network elements.

18. The method of claim 17, wherein the information of the one or more home session management network elements is the one or more home session management network elements supporting the HPLMN ID and the DNN selected by the serving communication agent network element.

19. The method of claim 13, wherein the second session management network element is an intermediate session management network element.

20. A method of selecting a session management network element, comprising:

the service communication agent network element acquires first parameter information according to the first message, wherein the first parameter information comprises the position information and DNN of the UE;

under the condition that a session management network element meeting the first parameter information exists, the service communication agent network element acquires a first request message according to the first message and sends the first request message to the session management network element; alternatively, the first and second electrodes may be,

and under the condition that the session management network element meeting the first parameter information does not exist, the service communication agent network element sends a rejection message to the mobility management network element, wherein the rejection message is used for indicating that the session management network element meeting the first parameter information does not exist.

21. The method of claim 20, further comprising:

the service communication agent network element selects a second session management network element according to the third parameter information;

22. The method of claim 21, wherein the second request message comprises information of one or more first session management network elements.

23. The method according to claim 21 or 22, further comprising:

24. The method according to claim 21 or 22, further comprising:

the service communication agent network element receives a response message from the second session management network element, and adds the information of the second session management network element into the head or the message body of the response message;

and the service communication agent network element sends the response message carrying the information of the second session management network element in the header or the message body to the mobility management network element.

25. The method according to claim 21 or 22, wherein the information of the second session management network element comprises one or more of service area information of a server of the second session management network element, identification information of the second session management network element, and a uniform resource identifier, URI, of the second session management network element.

26. A method of selecting a session management network element, comprising:

the method comprises the steps that a mobile management network element sends a first message to a service communication agent network element, wherein the first message comprises first parameter information and first request information, the first parameter information is used for selecting a session management network element, and the first parameter information comprises position information and DNN of UE;

the mobility management network element receives a rejection message from the serving communication agent network element, where the rejection message is used to indicate that there is no session management network element that satisfies the first parameter information.

27. The method of claim 26, further comprising:

and the mobility management network element sends a second message to the serving communication agent network element, where the second message includes third parameter information and a second request message, the third parameter information includes location information of the UE, and the third parameter information is used to select a second session management network element.

28. The method of claim 27, wherein the second request message comprises information of one or more first session management network elements.

29. The method of claim 27 or 28, further comprising:

the mobility management network element receives information from the second session management network element.

30. The method according to claim 29, wherein said information of said second session management network element comprises one or more of service area information of a server of said second session management network element, identification information of said second session management network element, and a uniform resource identifier, URI, of said second session management network element.

31. An apparatus for selecting a session management network element, comprising a processor:

the processor is used for reading and running the program from the memory to realize the method according to any one of claims 1-10.

32. An apparatus for selecting a session management network element, comprising a processor:

the processor is configured to read and execute a program from the memory to implement the method according to any one of claims 11 to 19.

33. An apparatus for selecting a session management network element, comprising a processor:

the processor is configured to read and execute a program from the memory to implement the method according to any one of claims 20 to 25.

34. An apparatus for selecting a session management network element, comprising a processor:

the processor is configured to read and execute a program from the memory to implement the method according to any one of claims 26 to 30.

35. A computer-readable storage medium having stored thereon instructions which, when executed on a computer, cause the computer to perform the method of any of claims 1-10, or the method of any of claims 11-19, or the method of any of claims 20-25, or the method of any of claims 26-30.

36. A communication system, characterized in that the communication system comprises an apparatus according to claim 31 and claim 32 or an apparatus according to claim 33 and claim 34.