CN109429362B

CN109429362B - Session processing method and device

Info

Publication number: CN109429362B
Application number: CN201710471318.1A
Authority: CN
Inventors: 唐廷芳; 李岩; 杨娇
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2017-06-20
Filing date: 2017-06-20
Publication date: 2022-02-11
Anticipated expiration: 2037-06-20
Also published as: CN109429362A

Abstract

The application provides a session processing method and a session processing device, wherein the method comprises the following steps: judging whether a first session management device serving a first session needs to be migrated or not by the first session management device; the first session management equipment sends a first message to the terminal equipment; if the first session management device determines that the first session management device does not need to be migrated, the first message is used for indicating that a first session identifier of the first session is carried when a second session is established; and if the first session management device judges that the first session management device needs to be migrated, the first message is used for indicating that a second session identifier is carried when the second session is established. For improving the reliability of the session handling.

Description

Session processing method and device

Technical Field

The embodiment of the invention relates to the technical field of communication, in particular to a session processing method and device.

Background

At present, when an application in a terminal device needs to perform network data transmission, a session needs to be established for the application in the terminal device, and the network data transmission is performed through the established session.

In a fifth Generation mobile communication technology (5th-Generation, abbreviated as 5G) network, a Session Management Function (SMF) network element manages a Session, such as establishment, deletion, release, and the like of the Session; user messages involved in a session are processed by a User Plane Function (UPF) network element, for example, message forwarding, message statistics, and the like. In the process of practical application. When the terminal device is displaced or the load of the UPF network element providing the data transmission service for the session is too high, the UPF network element needs to be replaced for the session of the terminal device. Specifically, in the process of replacing the UPF network element for the session, for a session in a Service and Session Continuity (SSC) 2 mode, the session may be released first and then re-established, and for a session in an SSC3 mode, the session may be re-established first and then released. When session reestablishment is performed, in the prior art, a previous SMF network element (an SMF network element that manages a session that needs to be released) is generally requested to reestablish a session after migration and provide a service for the session after migration, but the previous SMF network element may not provide a service for the session after migration, which results in poor reliability of session processing.

Disclosure of Invention

The embodiment of the invention provides a session processing method and device, which improve the reliability of session processing.

In a first aspect, the present application provides a session processing method, where an execution subject of the method is a first session management device of a first session providing server, and the first session management device determines whether the first session management device needs to be migrated, and sends a first message to a terminal device according to whether the first session management device needs to be migrated; when the first session management device is judged not to need to be migrated, the first message is used for indicating that a first session identifier of a first session is carried when a second session is established; and when the first session management equipment is judged to need to be migrated, the first message is used for indicating that a second session is established and carries a second session identifier.

It should be noted that the session management network element may be a session management device.

In the above process, the first message received by the terminal device indicates a session identifier (a first session identifier or a second session identifier) that needs to be carried when the second session is established, so that when the terminal device requests an access and mobility management function network element (e.g., an AMF network element) to establish the second session, the carried session identifier may be determined according to the first message, so that the access and mobility management function network element may select an appropriate session management device according to the session identifier carried in the request for establishing the second session, and provide a service for the second session by the appropriate session management device, thereby improving the reliability of session processing.

In a possible implementation manner, the first session management device may determine whether the first session management device needs to be migrated according to one or more of the following: a load of the first session management device; location information of the terminal device; and presetting a strategy. The information can accurately reflect whether the first session management device is suitable for continuously providing the session service for the terminal device, when the first session management device is suitable for continuously providing the session service for the terminal device, the first session management device does not need to be migrated, and when the first session management device is not suitable for continuously providing the session service for the terminal device, the first session management device needs to be migrated. Therefore, whether the first session management device needs to be migrated can be accurately judged according to the information.

Optionally, the first message is a session release reestablishment message, and the session release reestablishment message is used for requesting release of the first session and reestablishment of the second session.

In another possible implementation manner, the session identifier carried when the first message indicates to establish the second session may be determined in at least two possible manners:

one possible implementation is: when the first message comprises first indication information, the first indication information is used for indicating that a second session is established and carries a first session identifier; or, when the first message does not include the first indication information, the second message carries the second session identifier when indicating that the second session is established. In this feasible implementation manner, when the indication to establish the second session carries the second session identifier, no indication information needs to be carried in the first message, so that the signaling overhead can be reduced.

Another possible implementation: the first message comprises first indication information, and the first indication information is used for indicating that a second session is established and carries a first session identifier; or the first message comprises second indication information, and the second indication information is used for indicating that the second session is established and carries a second session identifier.

In another possible implementation, the first session managing device may release the first session according to the following feasible implementation: the first session management equipment receives a second message sent by the terminal equipment, wherein the second message comprises a first session identifier; the first session management device maintains session context information of a control plane of the first session, wherein the session context information of the control plane includes one or more of an address of a policy control function network element corresponding to the first session, policy information of the first session, and data network authorization information of the first session.

In the above process, when the first session management device releases the first session, the session context information of the control plane of the first session is retained, so that in the process of creating the second session, the session context information of the control plane of the first session can be reused, and the speed of creating the second session can be increased.

In another possible implementation, upon determining that the first session managing device does not need to migrate, the first session managing device may establish the second session according to the following feasible implementation: the first session management device receives a third message sent by the terminal device, wherein the third message is used for requesting to establish a second session, and the third message comprises a first session identifier, or the third message comprises the first session identifier and a second session identifier; the first session management device establishes a second session according to session context information of a control plane of the first session.

Optionally, the first session management device determines a user plane functional network element corresponding to the second session, allocates a second internet protocol IP address corresponding to the second session, and establishes a user plane path between the terminal device and the user plane functional network element; and the first session management equipment updates the first IP address of the session recorded by the policy management function network element corresponding to the first session into the second IP address.

In the above process, when the first session management device establishes the second session, the session context information of the control plane of the first session is reused, so that the speed of creating the second session can be increased.

In a second aspect, the present application provides a session processing method, where an execution subject of the method is a terminal device, and after the terminal device receives a first message from a first session management device serving a first session, the terminal device sends a fourth message to an access and mobility management function network element, where the first message is used to request release of the first session and establishment of a second session.

When the first message indicates that a second session is established and carries a first session identifier of the first session, the fourth message comprises the first session identifier; and when the first message indicates that the second session is established and carries the second session identifier, the fourth message comprises the second session identifier.

In the above process, the first message received by the terminal device indicates a session identifier (a first session identifier or a second session identifier) that needs to be carried when the second session is established, so that when the terminal device sends a fourth message to the access and mobility management function network element, the terminal device indicates the session identifier that needs to be carried according to the first message, and the fourth message carries a corresponding session identifier.

In a possible implementation manner, when the second session identifier is included in the fourth message, the fourth message further includes the first session identifier or the identifier of the first session managing device. In this way, the access and mobility management functional network element may select, according to the first session identifier or the identifier managed by the first session, a second session management device different from the first session management device, further ensuring that the appropriate session management device can provide services for the second session, and further improving the reliability of session processing.

In a third aspect, the present application provides a session processing method, where an execution subject of the method is a first session management device of a first session providing server, the first session management device determines whether the first session management device needs to be migrated, and when it is determined that the first session management device needs to be migrated, sends session context information of a control plane of a first session to a second session management device after the first session management device is migrated, and the session context information of the control plane of the first session includes at least one of an address of a policy control function network element corresponding to the first session that needs to be migrated, data network authorization information of the first session, and policy information of the first session.

In the above process, the first session management device determines whether migration is needed, and when the first session management device needs migration, the first session management device sends the session context information of the control plane of the first session to the migrated second session management device, so that the second session management device establishes the second session according to the session context information of the control plane of the first session, which can ensure that a proper session management device provides service for the second session, thereby improving the reliability of session processing.

In one possible implementation, the first session managing device determines whether the first session managing device can serve the first session according to one or more of the following:

a load of the first session management device;

location information of the terminal device;

and presetting a strategy.

Optionally, the first session management device may release the first session through the following feasible implementation manners: the first session management equipment receives a first session identifier of a first session from the terminal equipment; the first session management device maintains session context information of a control plane of the first session, wherein the session context information of the control plane includes one or more of an address of a policy control function network element corresponding to the first session, policy information of the first session, and data network authorization information.

Optionally, the second session management device may be determined by at least two possible implementations as follows:

one possible implementation is: the second session managing device is determined by the first session managing device.

Specifically, the first session management device determines the second session management device according to one or more of the location information of the terminal device and the load of the session management devices other than the first session management device; and the first session management equipment sends the identification of the second session management equipment to the access and mobility management function network element.

Another possible implementation: the second session management device is determined by the access and mobility management function network element.

Specifically, the first session management device sends a request message to the access and mobility management function network element, where the request message includes a session identifier of the first session, and the request message is used to trigger selection of the second session management device; the first session managing device receives a first session identification of the first session from the second session managing device.

In a fourth aspect, the present application provides a session processing apparatus, comprising a determining module and a sending module, wherein,

the judging module is used for judging whether the first session management equipment needs to be migrated or not;

the sending module is used for sending a first message to the terminal equipment;

if the judging module judges that the first session management equipment does not need to be migrated, the first message is used for indicating that a first session identifier of the first session is carried when the second session is established; and if the judging module judges that the first session management equipment needs to be migrated, the first message is used for indicating that the second session is established and carries a second session identifier.

In a possible implementation manner, the determining module is specifically configured to:

determining whether the first session management device needs to be migrated according to one or more of:

a load of the first session management device;

location information of the terminal device;

and presetting a strategy.

In another possible embodiment, the first message is a session release reestablishment message, and the session release reestablishment message is used for requesting release of the first session and reestablishment of the second session.

In another possible embodiment, the apparatus further comprises a receiving module and a session releasing module, wherein,

the receiving module is used for receiving a second message sent by the terminal equipment, wherein the second message comprises a first session identifier;

the session release module is configured to retain session context information of a control plane of the first session, where the session context information of the control plane includes one or more of an address of a policy control function network element corresponding to the first session, policy information of the first session, and data network authorization information of the first session.

In another possible embodiment, the apparatus further comprises a session establishment module, wherein,

the receiving module is further configured to receive a third message sent by the terminal device when the determining module determines that the first session management device does not need to be migrated, where the third message is used to request to establish a second session, and the third message includes the first session identifier, or the third message includes the first session identifier and the second session identifier;

the session establishing module is used for establishing a second session according to the session context information of the control plane of the first session.

In another possible implementation manner, the session establishing module is specifically configured to:

determining a user plane function network element corresponding to the second session, allocating a second Internet Protocol (IP) address corresponding to the second session, and establishing a user plane path between the terminal equipment and the user plane function network element;

and updating the first IP address of the session recorded by the policy management function network element corresponding to the first session into the second IP address.

In a fifth aspect, the present application provides a session processing apparatus, comprising a receiving module and a sending module, wherein,

the receiving module is used for receiving a first message from a first session management device serving the first session, wherein the first message is used for requesting the release of the first session and the establishment of a second session;

the sending module is used for sending a fourth message to the access and mobility management function network element;

if the first message indicates to establish the second session and carries the first session identifier of the first session, the fourth message comprises the first session identifier;

and if the first message indicates that the second session is established and carries the second session identifier, the fourth message comprises the second session identifier.

In a possible implementation manner, when the second session identifier is included in the fourth message, the fourth message further includes the first session identifier or the identifier of the first session managing device.

In another possible implementation, the first message includes first indication information, where the first indication information is used to indicate that the second session is established and carries a first session identifier;

alternatively, the first and second electrodes may be,

the first message does not include the first indication information to indicate that the second session is established and carries the second session identifier.

alternatively, the first and second electrodes may be,

the first message comprises second indication information, and the second indication information is used for indicating that a second session identifier is carried when the second session is established.

In a sixth aspect, the present application provides a session processing apparatus, comprising a determining module and a sending module, wherein,

the sending module is configured to send, to the second session management device after the migration of the first session management device, session context information of a control plane of the first session when the determining module determines that the first session management device needs to be migrated, where the session context information of the control plane of the first session includes at least one of an address of a policy control function network element corresponding to the first session to be migrated, data network authorization information of the first session, and policy information of the first session.

the first session management device determines whether the first session management device needs to be migrated according to one or more of:

a load of the first session management device;

location information of the terminal device;

and presetting a strategy.

the receiving module is used for receiving a first session identifier of a first session from the terminal equipment;

the session release module is configured to retain session context information of a control plane of the first session, where the session context information of the control plane includes one or more of an address of a policy control function network element corresponding to the first session, policy information of the first session, and data network authorization information.

In another possible embodiment, the apparatus further comprises a determination module, wherein,

the determining module is used for determining second session management equipment according to the position information of the terminal equipment and one or more loads of the session management equipment except the first session management equipment;

the sending module is further configured to send the identifier of the second session management device to the access and mobility management function network element.

In another possible implementation manner, the sending module is further configured to send a request message to the network element, where the request message includes a session identifier of the first session, and the request message is used to trigger selection of the second session management device;

the receiving module is further configured to receive a first session identifier of the first session from the second session management device.

In a seventh aspect, the present application provides a session management device, including a processor and a memory, where the memory is used to store program instructions, and the processor is used to read the program instructions in the memory and execute the method of any one of the above first aspects according to the program instructions in the memory.

In an eighth aspect, the present application provides a terminal device, including a processor and a memory, where the memory is used to store program instructions, and the processor is used to read the program instructions in the memory and execute the method of any one of the above second aspects according to the program instructions in the memory.

In a ninth aspect, the present application provides a session management device, comprising a processor and a memory, the memory being configured to store program instructions, and the processor being configured to read the program instructions from the memory and execute the method of any one of the above third aspects according to the program instructions in the memory.

In a tenth aspect, the present application provides a computer-readable storage medium having stored therein computer-executable instructions that, when executed by at least one processor of a storage device, cause the storage device to perform the data reading methods provided by the various possible designs described above.

In an eleventh aspect, the present application provides a computer program product comprising computer executable instructions stored in a computer readable storage medium. The computer executable instructions may be read by the at least one processor of the storage device from a computer readable storage medium, execution of which by the at least one processor causes the storage device to implement the data reading method provided by the various possible designs of the method embodiments described above.

In a twelfth aspect, the present application provides a chip system, which includes a processor for enabling a session management apparatus to implement the functions referred to in the above aspects, for example, to generate or process information referred to in the above methods. In one possible design, the system-on-chip further includes a memory for storing program instructions and data necessary for the data transmission device. The chip system may be constituted by a chip, or may include a chip and other discrete devices.

According to the session processing method and device provided by the application, the first session management device judges whether the first session management device needs to be migrated, and informs the terminal device whether a first session identifier needs to be carried when a second session is established through the first message. Therefore, when the terminal equipment requests the AMF network element to establish the second session, whether the terminal equipment carries the first session identifier can be determined according to the first message, so that the AMF network element can select proper session management equipment according to the request for establishing the second session, and the proper session management equipment provides service for the second session, thereby improving the reliability of session processing.

Drawings

FIG. 1 is a system architecture diagram provided herein;

fig. 2 is a first schematic diagram of a session processing method provided in the present application;

fig. 3 is a flowchart illustrating a method for releasing a first session according to the present application;

fig. 4 is a flowchart illustrating a method for establishing a second session according to the present application;

fig. 5 is a second schematic diagram of a session processing method provided in the present application;

fig. 6 is a third schematic diagram of a session processing method provided in the present application;

fig. 7 is a fourth schematic diagram of a session processing method provided in the present application;

fig. 8 is a fifth schematic diagram of a session processing method provided in the present application;

fig. 9 is a sixth schematic diagram of a session processing method provided in the present application;

fig. 10 is a first schematic structural diagram of a session processing apparatus provided in the present application;

fig. 11 is a schematic structural diagram of a session processing apparatus according to the present application;

fig. 12 is a schematic structural diagram of another session processing apparatus provided in the present application;

fig. 13 is a first schematic structural diagram of another session processing apparatus provided in the present application;

fig. 14 is a schematic structural diagram of another session processing apparatus provided in the present application;

fig. 15 is a schematic structural diagram of a session management device provided in the present application;

fig. 16 is a schematic structural diagram of a terminal device provided in the present application;

fig. 17 is a schematic structural diagram of a session management device according to the present application.

Detailed Description

Fig. 1 is a system architecture diagram provided herein. Referring to fig. 1, a communication system may include a terminal device (UE) 101, AN Access Network (AN) node 102, a User Plane Function (UPF) Network element 103, a Data Network (DN) 104, AN Access and Mobility Management Function (AMF) Network element 105, a Session Management Function (SMF) Network element 106, and a Policy Control Function (PCF) Network element 107.

Alternatively, the UE101 may be a mobile telephone (or so-called "cellular" telephone) or a computer having a mobile terminal, e.g., a mobile device that may be portable, pocket, hand-held, computer-included, or vehicle-mounted, etc.

The AN Node 102 may be a device providing WIreless Access to a terminal device, and includes but is not limited to AN Evolved Node B (Evolved Node B, eNB), a WIreless-FIdelity Access point (WiFi AP), a Worldwide Interoperability for Microwave Access Base Station (WiMAX BS), a Base Station in a 5G network, and the like.

The UPF network element 103 is mainly responsible for processing user messages, such as forwarding and counting messages, and the UFP network element 103 also completes execution of session-related policies according to the instruction of the SMF. The DN104 may be connected through a UPF network element 103.

The AMF network element 105 is configured to forward a message exchanged between the SMF and the UE, and is further configured to be responsible for mobility management in the mobile network, such as user location update, user registration network, user handover, and the like.

The SMF network element 106 is mainly responsible for session management in the mobile network, such as session establishment, session modification, session release, etc.

The PCF network element 107 is configured to make policies of the terminal device, such as Quality of Service (QoS) policies, slice selection policies, and the like.

It should be further noted that the session management network element may be a session management device, and hereinafter, the session management network element is taken as the session management device for example.

In the application, the SMF network element determines whether the SMF network element needs to be migrated or not, and sends a first message to the terminal device, according to whether the SMF network element is suitable for providing a session management service to a session or not, in real time or periodically or under a preset condition, and indicates whether the terminal device needs to carry a first session identifier of a first session when establishing a second session through the first message. When the SMF network element does not need to be migrated, the first message indicates that the first Session identifier is carried when the second Session is established, so that, when the terminal device requests the AMF network element to establish the migrated Session, the AMF network element may select an original SMF network element according to the first Session identifier, and route Session Management (SM) information (for example, also referred to as N1SM information), where the original SMF network element provides a service for the migrated Session. When the SMF network element needs to be migrated, the first message indicates that the first session identifier (which may be the second session identifier) does not need to be carried when the second session is established, so that, when the terminal device requests the AMF network element to establish the migrated session, the AMF network element may select a new SMF network element according to the second session identifier, and the new SMF network element provides a service for the migrated session. In the above process, the AMF network element can select a suitable SMF network element to provide service for the session after migration, so that the SMF network element selected by the AMF network element can provide service for the session after migration, and the reliability of session processing is further improved.

It should be noted that the session identifier carried when the second session is established refers to a session identifier sent to the AMF network element for the AMF network element to use when performing SMF network element selection, and the session identifier is not a session identifier carried in the session management information. The session management information is not visible to the AMF, and therefore, the session identifier carried when the second session is established is all parameters except the session management information unless explicitly stated otherwise. In specific implementation, the session management information may carry the first session identifier or the second session identifier, or both, according to specific situations. In addition, whether the SMF network element is migrated may also be whether the SMF network element is suitable for providing a service for the current session, where the SMF network element needs to migrate the corresponding SMF network element and is not suitable for providing a service for the current session, and the SMF network element does not need to migrate the corresponding SMF network element and is suitable for providing a service for the current session.

The technical means shown in the present application will be described in detail below with reference to specific examples. It should be noted that the following embodiments may be combined with each other, and the description of the same or similar contents in different embodiments is not repeated. Specifically, a session processing method is described by the embodiments shown in fig. 2 to fig. 6, and another session processing method is described by the embodiments shown in fig. 7 to fig. 9.

Fig. 2 is a first schematic diagram of a session processing method provided in the present application. Referring to fig. 2, the method may include:

s201, a first session management device serving for a first session determines whether the first session management device needs to be migrated.

Optionally, the first session management device may be an SMF network element. The first session management device may manage sessions of a plurality of terminal devices. The first session may be any one of the sessions of any terminal device managed by the first session management device.

Optionally, the first session management device may determine whether it needs to be migrated in real time or periodically. Or, the first session management device may also determine whether the first session management device needs to be migrated when determining that the UPF network element corresponding to the first session needs to be migrated.

Optionally, the UPF network element corresponding to the first session is a UPF network element providing services such as data transmission for the first session. The UPF network element migration corresponding to the first session means that the first session is migrated to obtain a second session, and other UPF network elements provide services for the second session. Wherein, migrating the first session means: and releasing the first session and then establishing the second session, or establishing the second session and then releasing the first session. The first session and the second session are used to provide the same service to the terminal device.

Optionally, the first session management device may determine, in real time or periodically, whether the UPF network element corresponding to the first session needs to be migrated. Of course, the first session management device may also determine whether the UPF network element corresponding to the first session needs to be migrated under a preset condition, for example, the preset condition may be that the terminal device corresponding to the first session is displaced.

For example, the first session management device may determine whether a UPF network element corresponding to the first session needs to be migrated according to one or more of the following determination conditions: whether the position of the terminal equipment corresponding to the first session is outside the service area of the UPF network element or not; and/or whether the load of the UPF network element is greater than a preset threshold.

And when the first session management device judges that the one or more judgment conditions are met, the first session management device determines that the UPF network element corresponding to the first session needs to be migrated. Of course, in the actual application process, it may also be determined whether the UPF network element corresponding to the first session needs to be migrated according to other determination conditions, which is not specifically limited in this application.

The first session management device migration means: and replacing one session management device for serving the second session after the first session is migrated, or adding one session management device for serving the first session and replacing one session management device for serving the second session.

When the session mode is the SSC2 mode, in the process of migrating the UPF network element corresponding to the first session, the first session needs to be released first, and then a second session after the first session is migrated needs to be established. Correspondingly, the first session management device migration refers to replacing one session management device to provide service for the second session after the first session migration.

For example, assuming that the first session management device currently provides service for the first session, during the first session migration process, the first session is released first, and then the second session after the first session migration is established. After establishing the second session, the second session is served by the second session management device.

When the session mode is the SSC3 mode, in the process of migrating the UPF network element corresponding to the first session, a second session after the migration of the first session needs to be established first, and then the first session is released. Correspondingly, the migration of the first session management device refers to adding one session management device to provide service for the first session and replacing one session management device to provide service for the second session.

For example, assume that the first session management device currently provides service for the first session, and during the first session migration process, the second session after the first session migration is established first, and then the first session is released. Before releasing the first session, the first session is served by the first session managing device and the second session managing device, and the second session is served by the second session managing device.

Optionally, the first session managing device determines whether the first session managing device is the first session service according to one or more of the following: a load of the first session management device; location information of the terminal device; and presetting a strategy. Optionally, the preset policy may be whether to request the same session management device to establish the second session, or the preset policy may be whether to request the same session management device to establish the second session when the load of the session management device is greater than a preset threshold, and of course, in an actual application process, the preset policy may be set according to actual needs, which is not specifically limited in this application.

Specifically, the first session management device may determine that the first session management device needs to be migrated when any one or more of the following determination conditions are satisfied: the load of the first session management equipment is greater than the preset load, the position of the terminal equipment is outside the service area of the first session management equipment, the first session management equipment does not meet the preset strategy, and the service quality of the first session management equipment for providing service for the first session is less than the preset threshold value. Alternatively, when the session management device does not provide the session service, the session management device may not provide the service to all sessions, or may not provide the service to the session of a certain terminal device.

Of course, in the actual application process, the determination condition for determining whether the first session management device needs to be migrated may be determined according to actual needs, which is not specifically limited in this application.

Optionally, when the SMF network element 1 determines that it is not suitable for providing the first session with the service (for example, when the SMF1 determines that the quality of providing the service for the first session is less than the preset threshold), before the SMF network element 1 sends the release reestablishment message to the terminal device, the SMF network element 1 may send a request message to the AMF network element, and the AMF network element determines whether there is a more suitable SMF network element for providing the session with the first session. If the AMF network element determines that there is no more suitable SMF network element to provide session service for the first session, the AMF sends a failure message to the SMF network element 1, and accordingly, the SMF network element 1 may determine that the SMF network element 1 does not need to migrate according to the failure message. Otherwise, the SMF network element 1 determines that the AMF network element 1 needs to be migrated. Optionally, when the SMF network element 1 determines that the SMF network element 1 does not need to migrate, the SMF network element 1 may continue to provide services for the first session by using an unoptimized path, or may directly release the first session.

Optionally, the AMF network element may also detect whether the first session management device needs to be migrated, and when the AMF network element detects that the first session management device needs to be migrated, the AMF network element sends a notification message to the first session management device to notify that the first session management device needs to be migrated.

S202, the first session management equipment sends a first message to the terminal equipment.

If the first session management device determines that the first session management device does not need to be migrated, the first message is used to indicate that the first session identifier (i.e., old session identifier, old session ID) of the first session is carried when the second session is established; if the first session management device determines that the first session management device needs to be migrated, the first message is used to indicate that the second session is established and carries a second session identifier (i.e., a new session identifier, new session ID).

Optionally, the first message may be a session release reestablishment message, and the session release reestablishment message is used to request release of the first session and reestablishment of the second session.

Optionally, whether the second session is established with the first session identifier of the first session may be indicated by the first message through at least the following two possible implementation manners:

one possible implementation is: the first message may or may not carry the first indication information.

When the first message includes the first indication information, the first indication information is used for indicating that the second session is established and carries the first session identifier. When the first message does not include the first indication information, the second message carries a second session identifier when indicating that the second session is established.

In this feasible implementation manner, when the first session management device does not need to be migrated, the first indication information is carried in the first message; when the first session management device needs to be migrated, the first indication information is not carried in the first message.

Accordingly, the terminal device may determine whether to carry the first session identifier when establishing the second session according to whether the first message includes the first indication information, so that, when the terminal device sends a request for establishing the second session to the AMF network element, the AMF network element may route the SM information or select the SMF network element according to the session identifier included in the request.

It should be noted that, in an actual application process, when the first message includes the first indication, the first indication information may also indicate that the second session identifier is carried when the second session is established. When the first message does not include the first indication information, the first message may further indicate to carry the first session identifier when the second session is established.

Another possible implementation: the first message may carry the first indication information or the second indication information.

When the first message includes the first indication information, the first indication information is used for indicating that the second session is established and carries the first session identifier.

And when the first message comprises second indication information, the second indication information is used for indicating that a second session is established and carries a second session identifier.

In this feasible implementation manner, when the first session management device does not need to be migrated, the first indication information is carried in the first message; and when the first session management equipment needs to be migrated, carrying second indication information in the first message.

Accordingly, the terminal device may determine whether to carry the first Session identifier when establishing the second Session according to the indication information carried in the first message, so that, when the terminal device sends a request for establishing the second Session to the AMF network element, the AMF network element may route a Session Management (SM) message or select the SMF network element according to the Session identifier included in the request.

According to the session processing method provided by the application, the first session management device judges whether the first session management device needs to be migrated, and informs the terminal device whether a first session identifier needs to be carried when a second session is established through the first message. Therefore, when the terminal equipment requests the AMF network element to establish the second session, whether the terminal equipment carries the first session identifier can be determined according to the first message, so that the AMF network element can select proper session management equipment according to the request for establishing the second session, and the proper session management equipment provides service for the second session, thereby improving the reliability of session processing.

On the basis of any of the above embodiments, optionally, in order to create the second session quickly, when the first session is released, the session context information of the control plane of the first session may be retained, so that the session context information of the control plane of the first session may be reused in the process of creating the second session. The process of releasing the first session and establishing the second session will be described in detail below by the embodiments described in fig. 3-4, respectively.

Fig. 3 is a flowchart illustrating a method for releasing a first session according to the present application. Please refer to fig. 3, which includes:

s301, the first session management device receives a second message sent by the terminal device, wherein the second message comprises a first session identifier.

It should be noted that, for the SSC2 mode, the embodiment shown in fig. 3 may be executed before the first session management device sends the first indication information to the terminal device, or the embodiment shown in fig. 3 may be executed after the first session management device sends the first indication information to the terminal device. The present application does not specifically limit the executing network element of the embodiment in fig. 3.

Optionally, when the terminal device needs to release the first session, the terminal device sends a second message to the first session management device, and the second message carries the first session identifier, and the second message is used to request to release the first session.

Optionally, the terminal device may send the second message to the first session management device through the AN node and the SMF network element.

S302, the first session management device reserves the session context information of the control plane of the first session.

The session context information of the control plane may include one or more of a PCF address corresponding to the first session, policy information of the first session, and DN authorization information. Of course, in an actual application process, the session context information of the control plane may also include other contents, which is not specifically limited in this application.

Optionally, the first session management device retains the session context information of the control plane of the first session and releases other contents of the first session, for example, a user plane path corresponding to the first session may be released, a first IP address corresponding to the first session may be deleted, and the like.

In the embodiment shown in fig. 3, when the first session is released, the session context information of the control plane of the first session is retained, so that the session context information of the control plane of the first session can be reused in the process of creating the second session, and thus, the speed of creating the second session can be increased.

It should be noted that, for the SSC3 mode, the first session management device may release the first session according to an existing procedure, and the procedure of releasing the first session may refer to the existing standard technology, which is not described herein again.

Fig. 4 is a flowchart illustrating a method for establishing a second session according to the present application. Referring to fig. 4, the method may include:

s401, the terminal equipment sends a fourth message to the AMF network element.

When the first session management device does not need to migrate, the first message indicates that the second session is established and carries the first session identifier, and correspondingly, the fourth message includes the first session identifier. The first session identity is used to cause the selection of the SMF network element by the AMF network element. In this scenario, the SMF network element selected by the AMF network element is the first session management device.

When the first session management device needs to be migrated, the first message indicates that the second session is established without carrying the first session identifier, and correspondingly, the fourth message includes the second session identifier. The second session identifier is used for enabling the AMF network element to select the SMF network element. Further, in order to make the SMF network element selected by the AMF network element different from the first session management device, the fourth message may carry the first session identifier or the identifier of the first session management device, so that the AMF network element selects an SMF in the session management devices other than the first session management device according to the identifier of the first session management device.

Optionally, the fourth message may further include SM information, the AMF network element does not parse the SM information, and the AMF network element forwards the SM information to the selected SMF network element. For the SSC2 mode, a first session identification is included in the SM message to enable the first session management device to reestablish the first session and, in turn, the second session. For the SSC3 mode, the SM message includes a second session identifier to enable the first session management device to newly establish the second session, and the SM message may further include a first session identifier to associate the second session with the first session.

S402, the AMF network element determines whether the session corresponding to the session identifier included in the fourth message is an established session.

If so, S405-S406 are performed.

If not, S403-S404 are executed.

When the first session identifier is included in the fourth message, it may be determined that the session corresponding to the session identifier included in the fourth message is an established session.

When the second session identifier is included in the fourth message, it may be determined that the session corresponding to the session identifier included in the fourth message is not an established session.

S403, the AMF network element selects the second session management device, and sends a third message to the second session management device.

Wherein the third message is for requesting establishment of the second session. The third message includes the second session identifier, or the third message includes the first session identifier and the second session identifier.

In this case, the session identifier included in the fourth message is the second session identifier, and the AMF network element determines that the second session is an unestablished session, and then selects a session management device for the second session.

And when the fourth message includes the first session identifier, the AMF network element determines that the session management device corresponding to the first session is the first session management device, and then the AMF network element selects a second session management device from the session management devices except the first session management device to ensure that the selected second session management device is different from the first session management device.

When the fourth message includes the identifier of the first session management device, the AMF network element may select a second session management device among the session management devices other than the first session management device according to the identifier of the first session management device, so as to ensure that the selected second session management device is different from the first session management device.

Optionally, the third message may be an SM message.

Optionally, the third message may include the second session identifier, or the third message may include the first session identifier and the second session identifier.

S404, the second session management device establishes a second session.

Optionally, when the third message includes the second session identifier, the second session management device creates a second session.

Optionally, when the third message includes the first session identifier and the second session identifier, the second session management device obtains the session context information of the control plane of the first session according to the first session identifier, and establishes the second session according to the session context information of the control plane of the first session. In this case, for the SSC2, the second session management device needs to determine whether session context information of the control plane of the first session exists, and if so, the second session management device establishes the second session according to the session context information of the control plane of the first session, and if not, the second session management device needs to establish a new second session. For the SSC3 mode, since the first session is released after the second session is established, at the time of the second session established by the second session management device, the session context information of the control plane of the first session may be generally acquired, and the second session may be established according to the session context information of the control plane of the first session.

Optionally, the second session management device may obtain session context information of the control plane recorded on the first session management device through the UDM or other channels. For example, obtaining PCF address information may allow the second session management device to find the same PCF when establishing a PDU-CAN session, and obtaining DN authorization information may allow the second session management device to avoid performing DN authentication authorization again.

In S404, the second session management device needs to establish a connection between the second session and the PCF.

S405, the AMF network element selects the first session management device, and sends a third message to the first session management device.

It should be noted that the third message in S405 is similar to the third message in S403, and is not described herein again.

S406, the first session management device establishes a second session.

Optionally, the first session management device may reestablish the first session according to the session context information of the control plane of the first session, so as to obtain the second session.

Further, the first session management device may also determine a UPF network element corresponding to the second session, establish a user plane path between the terminal device and the UPF network element, and allocate a second IP address corresponding to the second session; the second session can reuse the connection between the SMF and the PCF corresponding to the first session, if the connection is reused, the first IP address corresponding to the first session is updated to be the second IP address, otherwise, the connection between the SMF and the PCF corresponding to the second session is newly established, and then the strategy information of the second session is determined.

In the embodiment shown in fig. 4, when the second session is established, the session context information of the control plane of the first session can be reused, so that the speed of creating the second session can be increased.

Based on any of the above embodiments, the SSC2 mode and the SSC3 mode are different from each other in the process of session migration, and the following description will explain in detail the process of session migration in the SSC2 mode and the SSC3 mode by using the embodiments shown in fig. 5 to fig. 6, respectively, taking the first session management device as the SMF network element 1 and the second session management device as the SMF network element 2 as an example.

Fig. 5 is a schematic diagram of a session processing method provided in the present application. In the embodiment shown in fig. 5, the session mode is the SSC2 mode, please refer to fig. 5, the method may include:

s501, the SMF network element 1 judges whether the UPF network element corresponding to the first session needs to be migrated.

It should be noted that the execution process of S501 may refer to S201, and is not described herein again.

S502, when it is determined that the UPF network element corresponding to the first session needs to be migrated, the SMF network element 1 judges whether the SMF network element 1 needs to be migrated.

If so, S509-S514 are performed.

If not, S503-S508 are executed.

It should be noted that the SMF network element 1 may also determine whether the SMF network element 1 needs to be migrated under other conditions, for example, the SMF network element 1 may determine whether the SMF network element 1 needs to be migrated in real time or periodically. The embodiment of the present invention does not specifically limit the determination condition for determining whether the SMF network element 1 needs to be migrated.

S503, the SMF network element 1 sends a session release reestablishment message to the terminal device, where the session release reestablishment message includes the first indication information.

The session release reestablishment message is used for requesting release of the first session and establishment of the second session, and the SMF network element 1 determines that the migration is not performed, so the session release reestablishment message is used for indicating the terminal device to carry the first session identifier when the second session is established.

Optionally, the first indication information may be included in the session release reestablishment message. The first indication information may be newly added indication information or reuse existing reconstruction indication information.

S504, the terminal device sends a session release request message to the SMF network element 1, wherein the session release request includes a first session identifier.

It should be noted that S503 and S504 may be executed sequentially or in parallel; when S503 and S504 are sequentially executed, S504 may be executed first, and then S503 may be executed, and the execution sequence of S503 and S504 is not specifically limited in the present application.

S505, the SMF network element 1 reserves the session context information of the control plane of the first session, and releases the information except the session context information of the control plane of the first session.

S506, the terminal device sends a Non-access stratum (NAS) message to the AMF network element, wherein the NAS message comprises the first session identifier and the SM information.

It should be noted that the NAS message shown in this application includes at least two parts of content, one part of content is a session identifier other than the SM information (which may also be referred to as N1SM information), and the other part of content is the SM information. Wherein, the session identifier except the SM information is visible to the AMF network element (i.e. the AMF can resolve), and the content in the SM information is invisible to the AMF network element (i.e. the AMF cannot resolve). And the session identification except the SM information is used for the AMF network element to select the SMF network element, the AMF network element forwards the SM information to the selected SMF network element, and the selected SMF network element processes the SM information.

Wherein, the SM information of the NAS message in S506 includes the first session identifier.

Optionally, because the first session release reestablishment message received by the terminal device includes the first indication information, the terminal device carries the first session identifier in the NAS message sent to the AMF network element.

S507, the AMF network element selects the SMF network element 1 according to the first session identifier, and sends SM information to the SMF network element 1.

Wherein, the SM information comprises a first session identifier.

S508, the SMF network element 1 establishes the second session according to the session context information of the control plane of the first session.

Optionally, the SMF network element 1 reconstructs the first session according to the context information of the control plane of the first session, to obtain a second session, where a session identifier of the second session is the same as the first session identifier of the first session. It should be noted that, in the present application, the session identifier of the second session is a session identifier for identifying the second session, which may be the same as the first session identifier of the first session. However, the second session identification refers to another session identification different from the first session identification.

S509, the SMF network element 1 sends a session release reestablishment message to the terminal device.

The session release reestablishment message is used for requesting release of the first session and reestablishment of the second session, and the SMF network element 1 determines to perform migration, so the session release reestablishment message is used for indicating the terminal device to carry the second session identifier when the second session is established.

Optionally, the session release reestablishment message may not carry any indication information, or the session release reestablishment message may carry the second indication information.

S510, the terminal device sends a session release request message to the SMF network element 1, wherein the session release request includes a first session identifier.

S511, the SMF network element 1 reserves the session context information of the control plane of the first session, and releases the information except the session context information of the control plane of the first session.

Optionally, as shown above, the SMF network element 1 may also completely release the first session, that is, the SMF network element 1 may not retain the session context information of the control plane of the first session, and release all information related to the first session, including the information of the control plane and the user plane.

S512, the terminal device sends an NAS message to the AMF network element, wherein the NAS message comprises a second session identifier and SM information.

Optionally, the NAS message may further include a first session identifier or an identifier of the first session management device, so that the AMF network element selects, according to the first session identifier or the identifier of the first session management device, a second session management device different from the first session management device.

The SM information of the NAS message in S512 includes the second session identifier, or the SM information includes the first session identifier and the second session identifier.

And S513, the AMF network element selects the SMF network element 2 according to the second session identifier, and sends SM information to the SMF network element 2.

Optionally, when the NAS message received by the AMF network element only includes the second session identifier, the AMF network element selects the SMF network element according to the current location of the terminal device, the DN accessed by the second session, the SMF load, and the like.

Optionally, when the NAS message received by the AMF network element includes the first session identifier or the identifier of the first session management device, the AMF network element may further select the SMF network element 2 according to the first session identifier or the identifier of the first session management device. In this way it can be ensured that the SMF network element selected by the AMF network element is different from SMF network element 1.

Optionally, the SM information includes a second session identifier, or the SM information includes a first session identifier and a second session identifier.

And S514, the SMF network element 2 establishes a second session.

Optionally, when the SM information only includes the second session identifier, the SMF network element 2 establishes a new second session. When the SM information includes the first session identifier and the second session identifier, the SMF network element 2 may obtain the session context information of the control plane of the first session according to the first session identifier, and establish the second session according to the session context information of the control plane of the first session.

It should be further noted that the technical solution shown in the embodiment of fig. 5 has the beneficial effects of the technical solutions shown in the embodiments of fig. 2 to 4, and the beneficial effects of the technical solution shown in the embodiment of fig. 5 are not described again here.

Fig. 6 is a third schematic diagram of a session processing method provided in the present application. In the embodiment shown in fig. 6, the session mode is the SSC3 mode, please refer to fig. 6, the method may include:

s601, the SMF network element 1 judges whether the UPF network element corresponding to the first session needs to be migrated.

It should be noted that the execution process of S601 may refer to S201, and is not described herein again.

S602, when determining that the UPF network element corresponding to the first session needs to be migrated, the SMF network element 1 judges whether the SMF network element 1 needs to be migrated.

If yes, then S609-S614 are performed.

If not, S603-S608 are performed.

S603, the SMF network element 1 sends a session release reestablishment message to the terminal device, where the session release reestablishment message includes the first indication information and a Timer (Timer).

Optionally, the session release reestablishment message in S603 may refer to the session release reestablishment message in S503, and further, the session release reestablishment message in S603 further includes a timer, where the timer is used to instruct the terminal device to release the session after a specified time length.

S604, the terminal equipment sends NAS information to the AMF network element, wherein the NAS information comprises the first session identification and the SM information.

Optionally, the SM information of the NAS message in S604 may include the second session identifier, or the SM information may include the first session identifier and the second session identifier.

S605, the AMF network element selects the SMF network element 1 according to the first session identifier, and sends SM information to the SMF network element 1.

And S606, the SMF network element 1 establishes a second session.

Optionally, when the SM information only includes the second session identifier, the SMF network element 1 creates a new second session. And when the SM information comprises the first session identifier and the second session identifier, the SMF network element 1 establishes the second session according to the session context information of the control plane of the first session.

It should be noted that the execution process of S606 may refer to S406, and is not described herein again.

S607, the SMF network element 1 sends the second session identifier to the AMF network element.

And S608, the AMF network element records the binding relationship between the second session and the SMF network element 1.

And S609, after the timer is overtime (expired), the terminal equipment sends a session release request message to the SMF network element 1, wherein the session release request comprises a first session identifier.

S610, the SMF network element 1 releases the first session.

S611, the SMF network element 1 sends a session release reestablishment message to the terminal device.

Optionally, the session release reestablishment message in S611 may refer to the session release reestablishment message in S509, and further, the session release reestablishment message may further include a timer.

S612, the terminal device sends an NAS message to the AMF network element, wherein the NAS message comprises a second session identifier and SM information.

It should be noted that the NAS message in S612 is the same as the NAS message in S512, and is not described herein again.

And S613, the AMF network element selects the SMF network element 2 according to the second session identifier, and sends SM information to the SMF network element 2.

It should be noted that the execution process of S613 may refer to S513, and is not described herein again.

And S614, the SMF network element 2 establishes a second session.

It should be noted that the execution process of S614 may refer to S514, and is not described herein again.

S615, the SMF network element 2 sends the second session identifier to the AMF network element.

And S616, the AMF network element records the binding relationship between the second session and the SMF network element 2.

S617, after the timer is overtime, the terminal equipment sends a session release request message to the SMF network element 1, wherein the session release request includes a first session identifier

S618, the SMF network element 1 releases the first session.

It should be noted that, after the timer expires, the terminal device forwards the release request message of the first session through the AMF network element, and since the SMF network element 1 and the SMF network element 2 currently provide services for the first session at the same time, the AMF network element may send the release request message sent by the terminal device to the SMF network element 1, and may also send the release request message to the SMF network element 2. When the release request message is sent to the SMF network element 1, the SMF network element 1 releases the first session, and when the release request message is sent to the SMF network element 2, the SMF network element 2 sends the release request message to the SMF network element 1 again, and the SMF network element 1 releases the first session.

It should be further noted that the technical solution shown in the embodiment of fig. 6 has the beneficial effects of the technical solutions shown in the embodiments of fig. 2 to 4, and the beneficial effects of the technical solution shown in the embodiment of fig. 6 are not described again here.

Another session handling method is described below with the embodiments shown in fig. 7-9.

Fig. 7 is a fourth schematic diagram of a session processing method provided in the present application. Referring to fig. 7, the method may include:

s701, the first session management device sends a session release reestablishment message to the terminal device.

Optionally, the first session management device may send the session release reestablishment message to the terminal device when it is determined that the UPF network element corresponding to the first session needs to be migrated, and of course, may also send the session release reestablishment message to the terminal device under other trigger conditions.

Optionally, the session release reestablishment message is used to request release of the first session and reestablishment of the second session, and the session release reestablishment message is also used to indicate a request to the first session management device for establishing the second session.

It should be noted that, the process of the first session management device determining whether the UPF corresponding to the first session needs to be migrated may be referred to as S201, and details are not described here again.

S702, the first session management device releases the first session.

It should be noted that the execution process of S702 may refer to S301, and is not described herein again.

S703, after receiving the session establishment request, the first session managing device determines whether the first session managing device needs to be migrated.

If yes, go to step S704.

If not, go to S705.

The session establishment request in S703 is used to request establishment of the second session, and the terminal device sends the first session identifier to the AMF.

It should be noted that the execution process of S703 may refer to S202, and is not described herein again.

S704, sending the session context information of the control plane of the first session to the second session management device after the first session management device is migrated, and establishing the second session by the second session management device according to the session context information of the control plane of the first session.

The session context information of the control plane of the first session includes at least one of a PCF address corresponding to the first session and DN authorization information of the first session.

Before the first session management device sends at least one of the PCF address and the DN authorization information corresponding to the first session to the second session management device, the second session management device needs to be determined first, and optionally, the second session management device may be determined through at least two possible implementation manners as follows:

Optionally, the first session management device may determine the second session management device according to one or more of the location information of the terminal device and a load of the session management device other than the first session management device.

After the first session management device determines to obtain the second session management device, the first session management device may further send an identifier of the second session management device to the AMF network element, so that the AMF network element records a corresponding relationship between the first session and the second session management device.

Another possible implementation: the second session management device is determined by the AMF network element.

And the first session management equipment sends a request message to the AMF network element, wherein the request message comprises a second session identifier and is used for triggering the selection of the second session management equipment. After receiving the request message, the AMF network element determines a second session management device according to one or more of the location information of the terminal device and the load of the session management device except the first session management device.

After the AMF network element selects and completes the second session management device, the AMF network element further sends the first session identifier and the identifier of the first session management device to the second session management device, so that the second session management device requests the first session management device to obtain the session context information of the control plane of the first session.

It should be noted that, the process of the second session management device establishing the second session may refer to S404, which is not described herein again.

S705, the first session management device establishes a second session.

It should be noted that the execution process of S705 may refer to S406, and is not described herein again.

In the embodiment shown in fig. 7, when the first session management device determines that the UPF network element corresponding to the first session needs to be migrated, the first session management device first releases the first session, after receiving a session establishment request message requesting establishment of a second session, it is determined whether the first session managing apparatus needs to be migrated, when the first session managing device does not need to migrate, the first session managing device establishes a second session, when the first session management device needs to be migrated, the first session management device sends at least one of the PCF address and DN authorization information corresponding to the first session to the second session management device, so that the second session management device establishes the second session based on at least one of the PCF address and DN authorization information corresponding to the first session, and, as such, it can be determined that the second session is serviced by the appropriate session management device, thereby improving the reliability of the session handling.

Based on the embodiment shown in fig. 7, the SSC2 mode and the SSC3 mode are different from each other in the process of session migration, and the following describes in detail the process of session migration in the SSC2 mode and the SSC3 mode with the embodiments shown in fig. 8 to 9, respectively, taking the first session management device as the SMF network element 1 and the second session management device as the SMF network element 2 as an example.

Fig. 8 is a fifth schematic diagram of a session processing method provided in the present application. In the embodiment shown in fig. 8, the session mode is the SSC2 mode, please refer to fig. 8, the method may include:

s801, when the SMF network element 1 determines that the UPF network element corresponding to the first session needs to be migrated, the SMF network element 1 sends a session release reestablishment message to the terminal device.

It should be noted that the execution process of S801 may refer to S701, and details are not described here.

S802, the terminal equipment sends a session release request message to the SMF network element 1, wherein the session release request comprises a first session identifier.

S803, the SMF network element 1 reserves the session context information of the control plane of the first session, and releases the information other than the session context information of the control plane of the first session.

S804, the terminal equipment sends a session establishment request message to the SMF network element 1, wherein the session establishment request message comprises a first session identifier and a second session identifier.

S805, the SMF network element 1 determines whether the SMF network element 1 needs to perform migration.

If so, then S807-S809 are performed.

If not, go to S806.

S806, the SMF network element 1 establishes the second session according to the session context information of the control plane of the first session.

It should be noted that the execution process of S806 may refer to S406, and is not described herein again.

S807, the SMF network element 1 determines the SMF network element 2 according to one or more of the location information of the terminal device and the load of the session management device other than the first session management device.

Of course, it is also possible for the SMF network element 1 to request the AMF network element to select the SMF network element 2.

S808, the SMF network element 1 sends session context information of the control plane of the first session to the SMF network element 2.

And S809, the second session management device establishes a second session according to the session context information of the control plane of the first session.

It should be noted that the execution process of S809 may refer to S404, and is not described herein again.

It should be further noted that the technical solution shown in the embodiment of fig. 8 has the beneficial effects of the technical solutions shown in the embodiments of fig. 7 and fig. 3 to 4, and the beneficial effects of the technical solution shown in the embodiment of fig. 8 are not described again here.

Fig. 9 is a sixth schematic diagram of a session processing method provided in the present application. In the embodiment shown in fig. 9, the session mode is the SSC3 mode, please refer to fig. 9, the method may include:

s901, when the SMF network element 1 determines that the UPF network element corresponding to the first session needs to be migrated, the SMF network element 1 sends a session release reestablishment message to the terminal device.

Optionally, the release reestablishment message further includes a timer.

It should be noted that the execution process of S901 may refer to S701, and details are not described here.

S902, the terminal device sends a session establishment request message to the SMF network element 1, wherein the session establishment request message comprises a first session identifier and a second session identifier.

S903, the SMF network element 1 determines whether the SMF network element 1 needs to perform migration.

If so, S905-S909 are executed.

If not, S904, S908-S909 are executed.

S904, the SMF network element 1 establishes the second session according to the session context information of the control plane of the first session.

It should be noted that the execution process of S904 may refer to S406, and is not described herein again.

S905, the SMF network element 1 determines the SMF network element 2 according to one or more of the location information of the terminal device and the load of the session management device except the first session management device.

S906, the SMF network element 1 sends session context information of a control plane of the first session to the SMF network element 2.

S907, the second session management device establishes a second session according to the session context information of the control plane of the first session.

It should be noted that the execution process of S907 may refer to S404, and is not described herein again.

S908, when the timer expires, the terminal device sends a session release request message to the SMF network element 1, where the session release request includes the first session identifier.

S909, the SMF network element 1 releases the first session.

It should be noted that the technical solution shown in the embodiment of fig. 9 has the beneficial effects of the technical solutions shown in the embodiments of fig. 7 and fig. 3 to 4, and the beneficial effects of the technical solution shown in the embodiment of fig. 9 are not described again here.

In an actual application process, the SSC3 mode has two implementation manners, one is a scenario of multiple PUD sessions (multiple PDU sessions), that is, a session in the SSC3 mode is implemented by multiple sessions, when a UPF network element needs to be replaced for the session, a network side device notifies a terminal device, and the terminal device initiates a request for establishing a new session. The other scenario is a Multi-homed PDU session (Multi homed PDU session) based on a sixth generation network Protocol (Internet Protocol version 6, IPv6), that is, a session in an SSC3 mode is implemented in one session, and when a UPF network element needs to be replaced for the session, the session management device SMF selects a new UPF network element for the terminal device, allocates a new IP address, and then notifies the terminal device of the new IP address.

In the application, when the session management device determines that it is not suitable to provide service for the terminal device and needs to migrate, the session management device adds a new UPF network element and allocates a new IP as unsuitable, and the session management device does not allocate a new IP address to the session of the terminal device in a multi-homing PDU session manner, but implements the session by using a multi-PUD session, that is, the session management device sends a session release reestablishment message carrying a preset duration to the terminal device, the terminal device initiates establishment of a new session after receiving the session release reestablishment message, and performs IP allocation of the new session and establishment of related connections thereof in the session establishment flow. It should be noted that, the process of triggering the terminal device to initiate the establishment of the new session by the session management device may refer to the embodiments shown in fig. 6 and fig. 9, and details are not described here again.

It should be noted that, in the above embodiment, the NAS message sent by the terminal device to the AMF network element may also be another message, which is not limited in this application.

Fig. 10 is a schematic structural diagram of a session processing apparatus according to the present application. The session handling means may be arranged in the first session managing device. Referring to fig. 10, the apparatus may include a determining module 11 and a sending module 12, wherein,

the judging module 11 is configured to judge whether the first session management device needs to be migrated.

The sending module 12 is configured to send a first message to the terminal device.

If the determining module 11 determines that the first session management device does not need to be migrated, the first message is used to indicate that a first session identifier of the first session is carried when a second session is established; if the determining module 11 determines that the first session management device needs to be migrated, the first message is used to indicate that the second session identifier is carried when the second session is established.

It should be noted that the session processing apparatus described in this application may execute the method shown in the embodiments of fig. 2 to fig. 6, and the implementation principle and the beneficial effect thereof are similar, and are not described herein again.

In a possible implementation manner, the determining module 11 is specifically configured to:

a load of the first session management device;

location information of the terminal device;

and presetting a strategy.

In another possible implementation manner, the first message is a session release reestablishment message, and the session release reestablishment message is used for requesting release of the first session and reestablishment of the second session.

Fig. 11 is a schematic structural diagram of a session processing apparatus according to the present application. On the basis of the embodiment shown in fig. 10, please refer to fig. 11, the apparatus further comprises a receiving module 13 and a session releasing module 14, wherein,

the receiving module 13 is configured to receive a second message sent by the terminal device, where the second message includes the first session identifier;

the session releasing module 14 is configured to retain session context information of a control plane of the first session, where the session context information of the control plane includes one or more of an address of a policy control function network element corresponding to the first session, policy information of the first session, and data network authorization information of the first session.

In another possible embodiment, the apparatus further comprises a session establishment module 15, wherein,

the receiving module 13 is further configured to receive a third message sent by the terminal device when the determining module 11 determines that the first session management device does not need to migrate, where the third message is used to request to establish the second session, and the third message includes the first session identifier, or the third message includes the first session identifier and the second session identifier;

the session establishing module 15 is configured to establish the second session according to the session context information of the control plane of the first session.

In another possible implementation manner, the session establishing module 15 is specifically configured to:

and updating the first IP address of the session recorded by the policy management function network element corresponding to the first session to the second IP address.

Fig. 12 is a schematic structural diagram of another session processing apparatus provided in the present application. The session handling means may be provided in the terminal device. Referring to fig. 12, the apparatus may include a receiving module 21 and a transmitting module 22, wherein,

the receiving module 21 is configured to receive a first message from a first session management device serving a first session, where the first message is used to request release of the first session and establishment of a second session.

The sending module 22 is configured to send the fourth message to the access and mobility management function network element.

If the first message indicates that the second session is established, the first message carries a first session identifier of the first session, and the fourth message comprises the first session identifier;

and if the first message indicates that the second session is established and carries a second session identifier, the fourth message comprises the second session identifier.

In a possible implementation manner, when the second session identifier is included in the fourth message, the fourth message further includes a first session identifier or an identifier of the first session management device.

In another possible implementation manner, the first message includes first indication information, where the first indication information is used to indicate that the first session identifier is carried when the second session is established;

alternatively, the first and second electrodes may be,

the first message does not include the first indication information to indicate that the second session identifier is carried when the second session is established.

alternatively, the first and second electrodes may be,

the first message comprises second indication information, and the second indication information is used for indicating that the second session is established and carries the second session identifier.

Fig. 13 is a schematic structural diagram of another session processing apparatus provided in the present application. The session handling means may be arranged in the first session managing device. Referring to fig. 13, the apparatus may include a determining module 31 and a sending module 32, wherein,

the determining module 31 is configured to determine whether the first session management device needs to be migrated;

the sending module 32 is configured to send, to the second session management device after the first session management device is migrated, session context information of a control plane of the first session when the determining module determines that the first session management device needs to be migrated, where the session context information of the control plane of the first session includes at least one of an address of a policy control function network element corresponding to the first session to be migrated, data network authorization information of the first session, and policy information of the first session.

It should be noted that the session processing apparatus described in this application may execute the method shown in the embodiments of fig. 7 to 9, and the implementation principle and the beneficial effect thereof are similar, and are not described herein again.

In a possible implementation manner, the determining module 31 is specifically configured to:

the first session management device determines whether the first session management device needs to be migrated according to one or more of the following:

a load of the first session management device;

location information of the terminal device;

and presetting a strategy.

Fig. 14 is a schematic structural diagram of another session processing apparatus provided in the present application. On the basis of the embodiment shown in fig. 13, please refer to fig. 14, the apparatus further comprises a receiving module 33 and a session releasing module 34, wherein,

the receiving module 33 is configured to receive a first session identifier of the first session from the terminal device;

the session release module 34 is configured to retain session context information of a control plane of the first session, where the session context information of the control plane includes one or more of an address of a policy control function network element corresponding to the first session, policy information of the first session, and data network authorization information.

In another possible embodiment, the apparatus further comprises a determining module 35, wherein,

the determining module 35 is configured to determine the second session management device according to one or more of the location information of the terminal device and a load of a session management device other than the first session management device;

the sending module 32 is further configured to send the identifier of the second session management device to the access and mobility management function network element.

In another possible implementation manner, the sending module 32 is further configured to send a request message to a network element, where the request message includes a session identifier of the first session, and the request message is used to trigger selection of the second session management device;

the receiving module 33 is further configured to receive a first session identifier of the first session from the second session managing apparatus.

Fig. 15 is a schematic structural diagram of a session management device according to the present application. Referring to fig. 15, the apparatus includes a processor 41, a memory 42, and a communication bus 43, where the communication bus 43 is used to implement connection between various components, the memory 42 is used to store program instructions, and the processor 41 is used to read the program instructions in the memory 42 and execute the method shown in the above embodiments of fig. 2 to fig. 6 according to the program instructions in the memory 42. The implementation principle and the beneficial effect are similar, and the detailed description is omitted here.

Fig. 16 is a schematic structural diagram of a terminal device provided in the present application. Referring to fig. 16, the apparatus includes a processor 51, a memory 52 and a communication bus 53, where the communication bus 53 is used to implement connection between various components, the memory 52 is used to store program instructions, and the processor 51 is used to read the program instructions in the memory 52 and execute the method shown in the above embodiments of fig. 2 to fig. 6 according to the program instructions in the memory 52. The implementation principle and the beneficial effect are similar, and the detailed description is omitted here.

Fig. 17 is a schematic structural diagram of a session management device according to the present application. Referring to fig. 17, the apparatus includes a processor 61, a memory 62 and a communication bus 63, where the communication bus 63 is used to implement connection between various components, the memory 62 is used to store program instructions, and the processor 61 is used to read the program instructions in the memory 62 and execute the method shown in the above embodiments of fig. 7 to 9 according to the program instructions in the memory 62. The implementation principle and the beneficial effect are similar, and the detailed description is omitted here.

The present application provides a computer-readable storage medium having stored therein computer-executable instructions that, when executed by at least one processor of a storage device, cause the storage device to perform the data reading methods provided by the various possible designs described above.

A computer program product is provided that includes computer executable instructions stored in a computer readable storage medium. The computer executable instructions may be read by the at least one processor of the storage device from a computer readable storage medium, execution of which by the at least one processor causes the storage device to implement the data reading method provided by the various possible designs of the method embodiments described above.

The present application provides a chip system comprising a processor for enabling a data transmission apparatus to carry out the functions referred to in the above aspects, e.g. to generate or process data and/or information referred to in the above methods. In one possible design, the system-on-chip further includes a memory for storing program instructions and data necessary for the data transmission device. The chip system may be constituted by a chip, or may include a chip and other discrete devices.

Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the embodiments of the present invention, and are not limited thereto; although embodiments of the present invention have been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the embodiments of the present invention.

Claims

1. A session processing method, comprising:

a first session management network element serving a first session judges whether the first session management network element needs to be migrated;

the first session management network element sends a first message to the terminal equipment;

if the first session management network element judges that the first session management network element does not need to be migrated, the first message is used for indicating that a first session identifier of the first session is carried when a second session is established; and if the first session management network element judges that the first session management network element needs to be migrated, the first message is used for indicating that a second session identifier is carried when the second session is established.

2. The method of claim 1, wherein determining whether the first session managing network element needs to be migrated for a first session managing network element served by the first session comprises:

the first session management network element determines whether the first session management network element needs to be migrated according to one or more of the following:

a load of the first session management network element;

location information of the terminal device;

and presetting a strategy.

3. The method according to claim 1 or 2, wherein the first message is a session release reestablishment message, and the session release reestablishment message is used for requesting release of the first session and reestablishment of the second session.

4. The method according to any one of claims 1 or 2, further comprising:

the first session management network element receives a second message sent by the terminal equipment, wherein the second message comprises the first session identifier;

the first session management network element retains session context information of a control plane of the first session, wherein the session context information of the control plane includes one or more of an address of a policy control function network element corresponding to the first session, policy information of the first session, and data network authorization information of the first session.

5. The method of any of claims 1 or 2, wherein determining that the first session managing network element does not require migration further comprises:

the first session management network element receives a third message sent by the terminal device, where the third message is used to request to establish the second session, where the third message includes the first session identifier, or the third message includes the first session identifier and the second session identifier;

and the first session management network element establishes the second session according to the session context information of the control plane of the first session.

6. The method of claim 5, wherein the first session management network element establishing the second session according to session context information of a control plane of the first session comprises:

the first session management network element determines a user plane function network element corresponding to the second session, allocates a second Internet Protocol (IP) address corresponding to the second session, and establishes a user plane path between the terminal equipment and the user plane function network element;

and the first session management network element updates the first IP address of the session recorded by the policy management function network element corresponding to the first session to the second IP address.

7. The method according to any one of claims 1-2, 6,

the first message comprises first indication information, and the first indication information is used for indicating that the first session identifier is carried when the second session is established;

alternatively, the first and second electrodes may be,

8. The method according to any one of claims 1-2, 6,

alternatively, the first and second electrodes may be,

9. A session processing method, comprising:

the terminal equipment receives a first message from a first session management network element serving a first session, wherein the first message is used for requesting the release of the first session and the establishment of a second session;

the terminal equipment sends a fourth message to an access and mobility management function network element;

10. The method of claim 9, wherein when the second session identifier is included in the fourth message, the fourth message further includes a first session identifier or an identifier of the first session managing network element.

11. The method according to claim 9 or 10,

alternatively, the first and second electrodes may be,

12. The method according to claim 9 or 10,

alternatively, the first and second electrodes may be,

13. A session processing method, comprising:

and when determining that the first session management network element needs to be migrated, sending session context information of a control plane of the first session to a second session management network element after the first session management network element is migrated, where the session context information of the control plane of the first session includes at least one of an address of a policy control function network element corresponding to the first session to be migrated, data network authorization information of the first session, and policy information of the first session.

14. The method of claim 13, wherein determining whether the first session managing network element needs to be migrated for a first session managing network element served by the first session comprises:

the first session management network element determines whether the first session management network element can serve the first session according to one or more of the following:

a load of the first session management network element;

location information of the terminal device;

and presetting a strategy.

15. The method of claim 13 or 14, further comprising:

the first session management network element receives a first session identifier of the first session from a terminal device;

the first session management network element reserves session context information of a control plane of the first session, wherein the session context information of the control plane includes one or more of an address of a policy control function network element corresponding to the first session, policy information of the first session, and data network authorization information.

16. The method of claim 13 or 14, further comprising:

the first session management network element determines the second session management network element according to one or more of the position information of the terminal equipment and the load of the session management network element except the first session management network element;

and the first session management network element sends the identifier of the second session management network element to the access and mobility management function network element.

17. The method of claim 13 or 14, further comprising:

the first session management network element sends a request message to an access and mobility management function network element, wherein the request message comprises a session identifier of the first session, and the request message is used for triggering the selection of the second session management network element;

the first session managing network element receives a first session identification of the first session from the second session managing network element.

18. A conversation processing device is characterized by comprising a judging module and a sending module, wherein,

the judging module is used for judging whether the first session management network element needs to be migrated or not;

if the judging module judges that the first session management network element does not need to be migrated, the first message is used for indicating that a first session identifier of the first session is carried when a second session is established; and if the judging module judges that the first session management network element needs to be migrated, the first message is used for indicating that a second session identifier is carried when the second session is established.

19. The apparatus of claim 18, wherein the determining module is specifically configured to:

judging whether the first session management network element needs to be migrated according to one or more of the following items:

a load of the first session management network element;

location information of the terminal device;

and presetting a strategy.

20. The apparatus according to claim 18 or 19, wherein the first message is a session release reestablishment message, and the session release reestablishment message is used for requesting release of the first session and reestablishment of the second session.

21. The apparatus according to claim 18 or 19, wherein the apparatus further comprises a receiving module and a session release module, wherein,

the receiving module is configured to receive a second message sent by the terminal device, where the second message includes the first session identifier;

22. The apparatus according to claim 18 or 19, wherein the apparatus further comprises a receiving module and a session establishing module, wherein,

the receiving module is configured to receive a third message sent by the terminal device when the determining module determines that the first session management network element does not need to be migrated, where the third message is used to request to establish the second session, and the third message includes the first session identifier, or the third message includes the first session identifier and the second session identifier;

the session establishing module is configured to establish the second session according to session context information of a control plane of the first session.

23. The apparatus of claim 22, wherein the session establishment module is specifically configured to:

24. The apparatus of any one of claims 18-19, 23,

alternatively, the first and second electrodes may be,

25. The apparatus of any one of claims 18-19, 23,

alternatively, the first and second electrodes may be,

26. A conversation processing device is characterized by comprising a receiving module and a sending module, wherein,

the receiving module is configured to receive a first message from a first session management network element serving a first session, where the first message is used to request release of the first session and establishment of a second session;

27. The apparatus of claim 26, wherein when the second session identifier is included in the fourth message, the fourth message further includes a first session identifier or an identifier of the first session managing network element.

28. The apparatus of claim 26 or 27,

alternatively, the first and second electrodes may be,

29. The apparatus of claim 26 or 27,

alternatively, the first and second electrodes may be,

30. A conversation processing device is characterized by comprising a judging module and a sending module, wherein,

the sending module is configured to send, to a second session management network element after the first session management network element is migrated, session context information of a control plane of the first session when the determining module determines that the first session management network element needs to be migrated, where the session context information of the control plane of the first session includes at least one of an address of a policy control function network element corresponding to the first session to be migrated, data network authorization information of the first session, and policy information of the first session.

31. The apparatus of claim 30, wherein the determining module is specifically configured to:

a load of the first session management network element;

location information of the terminal device;

and presetting a strategy.

32. The apparatus according to claim 30 or 31, wherein the apparatus further comprises a receiving module and a session release module, wherein,

the receiving module is used for receiving a first session identifier of the first session from the terminal equipment;

33. The apparatus of claim 30 or 31, further comprising a determination module, wherein,

the determining module is configured to determine the second session management network element according to one or more of location information of the terminal device and a load of a session management network element other than the first session management network element;

the sending module is further configured to send the identifier of the second session management network element to the access and mobility management function network element.

34. The apparatus of claim 32,

the sending module is further configured to send a request message to an access and mobility management function network element, where the request message includes a session identifier of the first session, and the request message is used to trigger selection of the second session management network element;

the receiving module is further configured to receive a first session identifier of the first session from the second session management network element.