CN112333788B

CN112333788B - Session management method and device under N2 interface switching scene

Info

Publication number: CN112333788B
Application number: CN202011270331.9A
Authority: CN
Inventors: 朱咏梅
Original assignee: WUHAN HONGXU INFORMATION TECHNOLOGY CO LTD
Current assignee: WUHAN HONGXU INFORMATION TECHNOLOGY CO LTD
Priority date: 2020-11-13
Filing date: 2020-11-13
Publication date: 2022-10-11
Anticipated expiration: 2040-11-13
Also published as: CN112333788A

Abstract

The embodiment of the invention provides a session management method and a session management device under an N2 interface switching scene, wherein the method comprises the following steps: acquiring a session endpoint identifier and an IP address of a receiving end of a target NGAP message carried by the target NGAP message, and judging whether an NGAP session with the same session endpoint identifier and IP address as those of the receiving end exists in the established NGAP session or not; if yes, updating the value of the target cell in the NGAP session, wherein the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end, according to the message type of the target NGAP message. The session management method and the session management device under the N2 interface switching scene provided by the embodiment of the invention can associate the messages of the signaling flow of the N2 interface under the messages belonging to the same user, and can more conveniently realize the session management of the NGAP protocol under the N2 interface switching scene.

Description

Session management method and device under N2 interface switching scene

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a session management method and apparatus in an N2 interface switching scenario.

Background

In the 5G system, the N2 interface is an interface between the NG-RAN and the AMF. NG-RAN (NG Wireless Access Network, also called RAN) is a radio Access Network. The AMF (Access and Mobility Management) is an Access and Mobility Management network element, and is configured to terminate an N2 interface of the RAN control plane and terminate an N1 (NAS, non-Access-Stratum, signaling message between the UE and the AMF) interface, thereby implementing functions of NAS encryption and integrity protection, UE (User Equipment) registration, connection, reachability, mobility Management, and the like.

The NGAP (NG Application Protocol, application layer Protocol of N2 interface) message of the signaling flow of the N2 interface contains many valuable information, such as the location of the user and the identity of the user. In order to better operate the 5G network, it is necessary to perform session management on the N2 interface, that is, to manage the session context of the N2 interface of the same user, especially the session context management of the N2 interface during handover. However, session management in the current N2 interface switching scenario is an urgent issue to be solved in the field.

Disclosure of Invention

The embodiment of the invention provides a session management method and device in an N2 interface switching scene, which are used for solving the defect that the session management in the N2 interface switching scene cannot be realized in the prior art and realizing the session management in the N2 interface switching scene.

The embodiment of the invention provides a session management method under an N2 interface switching scene, which comprises the following steps:

acquiring a session endpoint identifier and an IP address of a receiving end of the target NGAP message carried by the target NGAP message, and judging whether an NGAP session with the same session endpoint identifier and IP address in the context as those of the receiving end exists in the established NGAP session or not;

if yes, updating the value of the target cell in the NGAP conversation, wherein the conversation endpoint identification and the IP address in the context are the same as the conversation endpoint identification and the IP address of the receiving end, according to the message type of the target NGAP message;

the target NGAP message is an NGAP message in an N2 interface switching scene; the target information element corresponds to the message type.

According to the session management method under the N2 interface switching scenario of an embodiment of the present invention, the message type includes at least one of a path switching request message, a path switching response message, a switching preparation request message, a switching resource allocation response message, a switching preparation response message, and a switching notification message; wherein the response message comprises a success response message and a failure response message.

According to the session management method under the N2 interface switching scenario of an embodiment of the present invention, the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end according to the message type of the target NGAP message includes:

and if the message type of the target NGAP message is a path switching request message, a path switching successful response message, a switching preparation request message, a switching resource allocation successful response message or a switching notification message, updating the value of the target cell carried by the target NGAP message into an NGAP session in which the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end.

According to the session management method under the N2 interface switching scenario of an embodiment of the present invention, the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end according to the message type of the target NGAP message further includes:

if the message type of the target NGAP message is a path switching request message, a path switching success response message, a switching preparation request message, a switching resource allocation success response message or a switching notification message, backing up the value of a backup cell carried by the target NGAP message;

wherein the backup cell is a part of the target cell; the backup cell is used for searching for the session.

if the message type of the target NGAP message is a path switching failure response message, restoring the value of the backup cell in the NGAP session, wherein the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end, according to the value of the backup cell corresponding to the target NGAP message and backed up;

the value of the backed-up cell corresponding to the target NGAP message is the value of the backed-up cell carried by the path switching request message corresponding to the target NGAP message.

if the message type of the target NGAP message is a switching resource allocation failure response message, restoring the value of the backup cell in the NGAP session, wherein the session endpoint identifier and the IP address in the context of the backup cell are the same as the session endpoint identifier and the IP address of the receiving end, according to the value of the backup cell corresponding to the target NGAP message and backed up;

wherein, the value of the backup cell backed up corresponding to the target NGAP message is the value of the backup cell carried by the handover resource allocation request message corresponding to the target NGAP message.

if the message type of the target NGAP message is a switching preparation failure response message, restoring the value of the backup cell in the NGAP session, wherein the session endpoint identifier and the IP address in the context of the backup cell are the same as the session endpoint identifier and the IP address of the receiving end, according to the value of the backup cell corresponding to the target NGAP message;

wherein the backed-up value of the backup cell corresponding to the target NGAP message is the value of the backup cell carried by the handover preparation request message corresponding to the target NGAP message.

An embodiment of the present invention further provides a session management device in an N2 interface switching scenario, including:

the user judgment module is used for acquiring the session endpoint identifier and the IP address of the receiving end of the target NGAP message carried by the target NGAP message, and judging whether the established NGAP session has the session endpoint identifier and the IP address which are the same as the session endpoint identifier and the IP address of the receiving end in the context;

a backup updating module, configured to update, if the message type of the target NGAP message exists, a value of a target cell in an NGAP session where a session endpoint identifier and an IP address in a context are the same as a session endpoint identifier and an IP address of the receiving end, according to the message type of the target NGAP message;

The embodiment of the present invention further provides an electronic device, which includes a memory, a processor, and a computer program that is stored in the memory and can be run on the processor, and when the processor executes the program, the steps of the session management method in any of the above N2 interface switching scenarios are implemented.

An embodiment of the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of the session management method in the N2 interface switching scenario.

The session management method and the session management device under the N2 interface switching scene provided by the embodiment of the invention determine the NGAP session belonging to the same UE with the target NGAP message through the session endpoint identifier and the IP address of the receiving end of the target NGAP message, update the value of the target cell in the NGAP session belonging to the same UE with the target NGAP message according to the message type of the target NGAP message, can associate the message of the signaling flow of the N2 interface under the message belonging to the same user, realize the management of the context of the NGAP session, improve the processing efficiency, simplify the program complexity, improve the association accuracy, and more conveniently realize the session management of the NGAP protocol under the N2 interface switching scene in the 5G system, and have the advantages of simple and easy processing, high accuracy and strong practicability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

Fig. 1 is a schematic flowchart of a session management method in an N2 interface switching scenario according to an embodiment of the present invention;

fig. 2 is a signaling flowchart in a session management method in an N2 interface switching scenario according to an embodiment of the present invention, in the switching scenario based on Xn;

fig. 3 is a signaling flowchart in a switching scenario based on N2 in a session management method in an N2 interface switching scenario according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a session management apparatus in an N2 interface switching scenario according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.

In the description of the embodiments of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the embodiments of the present invention and simplifying the description, but do not indicate or imply that the referred devices or elements must have specific orientations, be configured in specific orientations, and operate, and thus, should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the embodiments of the present invention, it should be noted that the terms "mounted," "connected" and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected or integrally connected unless otherwise explicitly stated or limited; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. Specific meanings of the above terms in the embodiments of the present invention can be understood in specific cases by those of ordinary skill in the art.

In order to overcome the above problems in the prior art, embodiments of the present invention provide a session management method and apparatus in an N2 interface handover scenario, where in the N2 interface handover scenario, an NGAP session context of all established UEs is searched through a certain set of parameters in a target signaling (i.e., a target NGAP message) to find an NGAP session belonging to the same UE as a current message, and an effective parameter (i.e., a value of a target cell) in the target NGAP message is stored in a session, thereby implementing session management in the N2 interface handover scenario.

Fig. 1 is a schematic flowchart of a session management method in an N2 interface switching scenario according to an embodiment of the present invention. The following describes a session management method in an N2 interface switching scenario according to an embodiment of the present invention with reference to fig. 1. As shown in fig. 1, the method includes: step S101, obtaining the session endpoint identification and IP address of the receiving end of the target NGAP message carried by the target NGAP message, and judging whether the established NGAP session has the NGAP session with the session endpoint identification and the IP address in the context the same as those of the receiving end.

The target NGAP message is the NGAP message in the N2 interface switching scene.

Specifically, in the N2 interface handover scenario, multiple interactive signaling may be generated between the NG-RAN and the AMF. Each interactive signaling generated in the above process can be respectively used as a target NGAP message.

Session management first needs to determine the NGAP session belonging to the same UE as the target NGAP message.

And for the target NGAP message, acquiring the session endpoint identifier and the IP address of the opposite-end network element carried by the target NGAP message.

The opposite terminal network element of the target NGAP message refers to the receiving terminal of the target NGAP message.

The session endpoint identifier and the IP address of the peer network element may be a session endpoint identifier and an IP address of a control plane and/or a data plane of the peer network element. The session endpoint identity and IP address of the control plane of the peer network element are used first and the session endpoint identity and IP address of the data plane are used second.

Searching the established NGAP session according to the session endpoint identification and the IP address of the receiving end of the target NGAP message preferentially; and secondly, searching the established NGAP session according to the session endpoint identification and the IP address of the data surface of the receiving end of the target NGAP message.

For different signaling, if the peer network element changes, the session endpoint identifier and IP address of the data plane, that is, TEID and IP of gNB and UPF, may be used to find the established NGAP session.

The purpose of searching the established NGAP session is to determine whether there is an NGAP session belonging to the same UE as the target NGAP message in the established NGAP session.

If the established NGAP session and the target NGAP message belong to the same UE, the session endpoint identifier and the IP address in the established NGAP session context are the same as the session endpoint identifier and the IP address of the receiving end of the target NGAP message.

For any established NGAP session, whether the session endpoint identification and the IP address in the NGAP session context are the same as the session endpoint identification and the IP address of the receiving end of the target NGAP message can be judged.

If yes, the NGAP session and the target NGAP message belong to the same UE; if not, the NGAP session and the target NGAP message belong to different UEs.

If the session endpoint identification and the IP address in each established NGAP session context are different from the session endpoint identification and the IP address of the receiving end of the target NGAP message, the NGAP session with the session endpoint identification and the IP address in the context identical to the session endpoint identification and the IP address of the receiving end does not exist in the established NGAP session.

If the session endpoint identification and the IP address in the context of a certain established NGAP session are the same as the session endpoint identification and the IP address of the receiving end of the target NGAP message, the established NGAP session has the NGAP session in which the session endpoint identification and the IP address in the context are the same as the session endpoint identification and the IP address of the receiving end.

Step S102, if the message type of the target NGAP message exists, updating the value of the target cell in the NGAP session, wherein the session endpoint identification and the IP address in the context are the same as the session endpoint identification and the IP address of the receiving end;

wherein the target cell corresponds to the message type.

Specifically, if an NGAP session exists in the established NGAP session, where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end, the NGAP session in the context, where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end, is an NGAP session belonging to the same UE as the target NGAP message.

The current value of the target cell in the NGAP session belonging to the same UE as the target NGAP message can be updated to a new value or restored to an old value according to the message type of the target NGAP message, so as to facilitate the session management for other target NGAP messages later.

The target cell is the valid cell that needs to be saved to the NGAP session.

The embodiment of the invention determines the NGAP session belonging to the same UE with the target NGAP message through the session endpoint identification and the IP address of the receiving end of the target NGAP message, updates the value of the target cell in the NGAP session belonging to the same UE with the target NGAP message according to the message type of the target NGAP message, can associate the message of the signaling flow of the N2 interface under the message belonging to the same user, realizes the management of the context of the NGAP session, can improve the processing efficiency, can simplify the program complexity, can improve the accuracy of association, can more conveniently realize the session management of the NGAP protocol under the switching scene of the N2 interface in the 5G system, and has the advantages of simple and easy processing, high accuracy and strong practicability.

Based on the content of the foregoing embodiments, the message type includes at least one of a path switching request message, a path switching response message, a switching preparation request message, a switching resource allocation response message, a switching preparation response message, and a switching notification message; wherein the response message comprises a success response message and a failure response message.

Specifically, the N2 interface switching scenario may include two types: n2 based handover and Xn based handover.

The N2 based handover is a handover in which both the NG-RAN and the AMF are changed.

Xn based handover is handover where only NG-RAN changes and AMF remains unchanged.

Based on the Xn handover scenario, the messages that occur on the N2 interface during the handover process include the following signaling: (1) path switching request message: PATH SWITCH REQUEST; (2) path switching success response message: PATH SWITCH REQUEST ACKNOWLEDGE; (3) path switch failure response message: PATH SWITCH REQUEST FAILURE.

The path switching response message comprises a path switching success response message and a path switching failure response message.

For the PATH SWITCH REQUEST message, the fields AMF UE NGAP ID and AMF IP in the message are used to associate with the established NGAP session context.

For the PATH SWITCH REQUEST ACKNOWLEDGE message, the RAN UE NGAP ID and RAN IP are used to associate with the established NGAP session context.

For the PATH SWITCH REQUEST FAILURE message, the RAN UE NGAP ID and RAN IP are used to associate with the established NGAP session context.

In the Xn-based handover scenario, the signaling flow occurring on the N2 interface is only the path handover signaling flow between the destination NG-RAN and the AMF. At this time, because the AMF is not changed, the path switch request message uses the session endpoint identifier and IP of the AMF to associate with the NGAP session context that the user has already established, and after finding the corresponding session context, updates the session endpoint identifier and IP of the RAN, and then uses the session endpoint identifier and IP of the RAN to associate with the NGAP session context that the user has already established in the path switch response.

Fig. 2 is a signaling flowchart in an Xn-based handover scenario in a session management method in an N2 interface handover scenario according to an embodiment of the present invention. As shown in fig. 2, in the Xn-based handover scenario, the destination NG-RAN sends a path switching request message to the AMF, where an opposite-end network element of the path switching request message is the AMF; and the AMF sends a path switching success response message to the target NG-RAN after the request response is successful, and the opposite terminal network element of the path switching success response message is the target NG-RAN.

In the handover scenario based on N2, the handover process includes three phases, namely, a handover preparation phase, a handover resource allocation phase, and a handover notification phase, and the messages occurring at the N2 interface in each message flow of the handover process include the following messages: (1) handover preparation request message: HANDOVER REQUIRED; (2) handover preparation success response message: HANDOVER COMMAND; (3) handover preparation failure response message: HANDOVER preamble FAILURE; (4) handover resource allocation request message: HANDOVER REQUEST; (5) handover resource allocation success response message: HANDOVER REQUEST ACKNOWLEDGE; (6) handover resource allocation failure response message: HANDOVER FAILURE; (7) handover notification message: HANDOVER NOTIFY.

The handover preparation response message includes a handover preparation success response message and a handover preparation failure response message.

The switching resource allocation response message comprises a switching resource allocation success response message and a switching resource allocation failure response message.

In the HANDOVER preparation process, for the HANDOVER REQUIRED message, using fields AMF UE NGAP ID and AMF IP in the message to associate with the established NGAP session context; for the HANDOVER COMMAND message, this message is not processed; for the HANDOVER prepare FAILURE message, the established NGAP session context is associated through the RAN UE NGAP ID and the RAN IP.

In the process of switching resource allocation, for a HANDOVER REQUEST message, using the TEID and IP of UPF to associate with the established NGAP session context; for the HANDOVER REQUEST ACKNOWLEDGE message, associating with the established NGAP session context using AMF UE NGAP ID and AMF IP; for HANDOVER FAILURE messages, the AMF UE NGAP ID and AMF IP are also used to associate with the established NGAP session context.

In the HANDOVER notification process, for the HANDOVER NOTIFY message, the AMF UE NGAP ID and the AMF IP are used to associate with the established NGAP session context.

Based on the switching scene of N2, the switching preparation phase and the switching execution phase are all completed on the N2 interface under the switching scene. In a handover preparation phase, when the user is not handed over to the target NG-RAN and the AMF, a signaling message occurs between the source NG-RAN and the source AMF, and the session endpoint identification and the IP of the source AMF are associated with the NGAP session context that the user has established. In the handover resource allocation phase, when the user has handed over to the destination NG-RAN and AMF, a signaling message occurs between the destination NG-RAN and the destination AMF, because the NG-RAN and the AMF have changed, only the session endpoint identification of the data plane can be used to associate the NGAP session context, that is, the TEID and IP of the UPF are used to associate the established NGAP session context of the user. In the handover notification phase, when the handover of the user has been completed, a signaling message occurs between the destination NG-RAN and the destination AMF, because the information of the destination NG-RAN and the destination AMF has been stored in the handover resource allocation phase in the NGAP session context of the user, the NGAP session context of the user is associated with the session endpoint identification and IP of the new AMF at this time.

Fig. 3 is a signaling flowchart in a handover scenario based on N2 in a session management method in an N2 interface handover scenario provided in an embodiment of the present invention. As shown in fig. 3, in a handover scenario based on N2, a source NG-RAN sends a handover preparation request message to a source AMF, where an opposite-end network element of the handover preparation request message is the source AMF; the target AMF sends a switching resource allocation request message to the target NG-RAN, and an opposite terminal network element of the switching resource allocation request message is the target NG-RAN; the target NG-RAN sends a response message of successful switching resource allocation to the target AMF, and the opposite-end network element of the response message of successful switching resource allocation serves as the target AMF; the source AMF sends a response message of successful switching preparation to the source NG-RAN, and an opposite terminal network element of the response message of successful switching preparation is the source NG-RAN; and the target NG-RAN sends a switching notification message to the target AMF, and the opposite end network element of the switching notification message is the target AMF.

And the session endpoint identification and the IP address of the control plane of the opposite terminal in the path switching request message are AMF UE NGAP ID and IP address.

And the session endpoint identification and the IP address of the control plane of the opposite terminal in the path switching success response message are the RAN UE NGAP ID and the IP address.

And the session endpoint identification and the IP address of the control plane of the opposite terminal in the switching preparation request message are AMF UE NGAP ID and AMF IP address.

And the session endpoint identification and the IP address of the data plane in the switching resource allocation request message are the TEID and the IP address of the UPF.

And the session endpoint identification and the IP address of the control plane of the opposite terminal in the switching resource allocation response message are AMF UE NGAP ID and IP address.

And the session endpoint identification and the IP address of the control plane of the opposite terminal in the switching preparation failure response message are the RAN UE NGAP ID and the IP address.

And the session endpoint identification and the IP address of the control plane of the opposite terminal in the switching notification message are AMF UE NGAP ID and IP address.

The embodiment of the invention aims at two conditions of an N2 interface switching scene, associates the target NGAP message with the established NGAP session according to the session endpoint identifier and the IP address of the receiving end carried by the target NGAP message, can realize the management of the context of the NGAP session, can more conveniently realize the session management of the NGAP protocol under the N2 interface switching scene in the 5G system, and has the advantages of simple and easy processing, high accuracy and strong practicability.

Based on the content of the foregoing embodiments, according to the message type of the target NGAP message, the specific step of updating the value of the target cell in the NGAP session in which the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end includes: and if the message type of the target NGAP message is a path switching request message, a path switching successful response message, a switching preparation request message, a switching resource allocation successful response message or a switching notification message, updating the value of the target cell carried by the target NGAP message into the NGAP session with the same session endpoint identifier and IP address in the context as the session endpoint identifier and IP address of the receiving end.

Specifically, the message type of the target NGAP message is a path switch request message, a path switch success response message, a switch preparation request message, a switch resource allocation success response message, or a switch notification message, and the current value of the target cell in the NGAP session belonging to the same UE as the target NGAP message may be updated to the value of the target cell carried by the target NGAP message.

All valid cells (i.e. target cells) to be stored in the path switching request message include RAN UE NGAP ID parameter, tend parameter and IP parameter of gNB, RAN IP address, location information of user and PDU Session ID. The location information of the user includes a TAI and an NGCI.

All the effective cells to be stored in the response message of successful path switching are AMF UE NGAP ID parameters, TEID and IP values of UPF, AMF IP address and PDU Session ID.

All valid cells (i.e. target cells) to be stored in the handover preparation request message include RAN UE NGAP ID parameter, TEID parameter and IP parameter of UPF, RAN IP address and PDU Session ID.

All valid cells (i.e. target cells) to be stored in the handover resource allocation request message include parameters AMF UE NGAP ID, AMF IP address and PDU Session ID.

All valid cells (i.e. target cells) to be stored in the handover resource allocation success response message include parameters RAN UE NGAP ID, TEID and IP of gNB, RAN IP address and PDU Session ID.

All valid cells (i.e. target cells) to be saved in the handover notification message include the parameters RAN UE NGAP ID, location information of the user and RAN IP address. The location information of the user includes a TAI and an NGCI.

According to the embodiment of the invention, the value of the target cell carried by the target NGAP message is updated to the NGAP session in which the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end according to the path switching request message, the path switching success response message, the switching preparation request message, the switching resource allocation success response message or the switching notification message, so that the management of the NGAP session context can be realized, the session management of the NGAP protocol under the switching scene of the N2 interface in the 5G system can be realized more conveniently, and the processing is simple and easy to implement, the accuracy is high, and the practicability is strong.

Based on the content of the foregoing embodiments, according to the message type of the target NGAP message, the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end further includes: if the message type of the target NGAP message is a path switching request message, a path switching success response message, a switching preparation request message, a switching resource allocation success response message or a switching notification message, the value of the backup cell carried by the target NGAP message is backed up.

Wherein, the backup cell is a part of the target cell; and the backup cell is used for searching the session.

Specifically, the message type of the target NGAP message is a path switch request message, a path switch success response message, a switch preparation request message, a switch resource allocation success response message, or a switch notification message, and except that the current value of the target cell in the NGAP session belonging to the same UE as the target NGAP message may be updated to the value of the target cell carried by the target NGAP message, the value of the backup cell carried by the target NGAP message may also be backed up.

The valid information element (i.e., the backup information element) for the lookup session in the path switch request message includes the RAN UE NGAP ID parameter, the TEID parameter and IP parameter of the gNB, and the RAN IP address.

The valid cell (i.e., the backup cell) for the lookup session in the path switch success response message includes the AMF UE NGAP ID parameter, the TEID and IP values of the UPF, and the AMF IP address.

The valid information element (i.e., the backup information element) for the lookup session in the handover preparation request message includes the RAN UE NGAP ID parameter, the TEID parameter and IP parameter of the UPF, and the RAN IP address.

The effective cell (namely backup cell) for searching the session in the switching resource allocation request message comprises an AMF UE NGAP ID and an AMF IP address;

the valid information element (i.e., the backup information element) for searching the session in the handover resource allocation success response message includes the RAN UE NGAP ID, the TEID and IP of the gNB, and the RAN IP address.

The valid information element (i.e., the backup information element) used to find the session in the handover notification message includes the RAN UE NGAP ID and the RAN IP address.

The embodiment of the invention backups the value of the backup cell carried by the target NGAP message according to the path switching request message, the path switching success response message, the switching preparation request message, the switching resource allocation success response message or the switching notification message, thereby restoring the value of the backup cell in the NGAP conversation belonging to the same UE as the target NGAP message according to the value of the backup cell, realizing the management of the context of the NGAP conversation, more conveniently realizing the conversation management of the NGAP protocol under the switching scene of the N2 interface in the 5G system, and having simple and easy processing, high accuracy and strong practicability.

Based on the content of the foregoing embodiments, according to the message type of the target NGAP message, the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end further includes: if the message type of the target NGAP message is a path switching failure response message, restoring the values of the backup cells in the NGAP conversation, wherein the conversation endpoint identification and the IP address in the context are the same as the conversation endpoint identification and the IP address of the receiving end, according to the backup cells corresponding to the target NGAP message.

The value of the backed-up backup cell corresponding to the target NGAP message is the value of the backup cell carried by the path switching request message corresponding to the target NGAP message.

Specifically, the path switch failure response message indicates that the response to the path switch request is failed, and after determining that the path switch failure response message belongs to the NGAP session of the same UE according to the session endpoint identifier and the IP address of the control plane of the opposite end carried by the path switch failure response message, the current value of the backup cell in the target cell in the NGAP session is restored to the value of the backup cell carried by the path switch request message corresponding to the path switch failure response message.

The path switching failure response message is generated after responding to the path switching request message corresponding to the path switching failure response message.

It should be noted that, for the non-backup cell in the target cell in the NGAP session, the restoration is not performed.

The embodiment of the invention restores the value of the backup cell in the NGAP conversation belonging to the same UE with the path switching failure response message according to the value of the backup cell corresponding to the path switching failure response message, can realize the management of the context of the NGAP conversation, can more conveniently realize the conversation management of the NGAP protocol under the switching scene of the N2 interface in the 5G system, and has the advantages of simple and easy processing, high accuracy and strong practicability.

Based on the content of the foregoing embodiments, according to the message type of the target NGAP message, the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end further includes: if the message type of the target NGAP message is a switching resource allocation failure response message, restoring the values of the backup cells in the NGAP session, wherein the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end, according to the value of the backup cells corresponding to the target NGAP message.

The value of the backed-up backup cell corresponding to the target NGAP message is the value of the backup cell carried by the switching resource allocation request message corresponding to the target NGAP message.

Specifically, the handover resource allocation failure response message indicates that the response to the handover resource allocation request fails, and after determining that the handover resource allocation failure response message belongs to the NGAP session of the same UE according to the session endpoint identifier and the IP address of the control plane of the opposite terminal carried in the handover resource allocation failure response message, the current value of the backup cell in the target cell in the NGAP session is restored to the value of the backup cell carried in the handover resource allocation request message corresponding to the handover resource allocation failure response message.

The switching resource allocation failure response message is generated after responding to the switching resource allocation request message corresponding to the switching resource allocation failure response message.

It should be noted that, for the non-backup cell in the target cell in the NGAP session, no restoration is performed.

The embodiment of the invention restores the value of the backup cell in the NGAP conversation belonging to the same UE with the switching resource allocation failure response message according to the value of the backup cell corresponding to the switching resource allocation failure response message, can realize the management of the context of the NGAP conversation, can more conveniently realize the conversation management of the NGAP protocol under the switching scene of the N2 interface in the 5G system, and has the advantages of simple and easy processing, high accuracy and strong practicability.

Based on the content of the foregoing embodiments, according to the message type of the target NGAP message, the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end further includes: if the message type of the target NGAP message is a switching preparation failure response message, restoring the values of the backup cells in the NGAP conversation, wherein the conversation endpoint identification and the IP address in the context are the same as the conversation endpoint identification and the IP address of the receiving end, according to the value of the backup cells corresponding to the target NGAP message.

The value of the backed-up backup cell corresponding to the target NGAP message is the value of the backup cell carried by the switching preparation request message corresponding to the target NGAP message.

Specifically, the handover preparation failure response message indicates that the response to the handover preparation request is failed, and after determining that the handover preparation failure response message belongs to the NGAP session of the same UE according to the session endpoint identifier and the IP address of the control plane of the opposite terminal carried by the handover preparation failure response message, the current value of the backup cell in the target cell in the NGAP session is restored to the value of the backup cell carried by the handover preparation failure request message corresponding to the handover preparation failure response message.

The handover preparation failure response message is generated in response to the handover preparation request message corresponding to the handover preparation failure response message.

The embodiment of the invention restores the value of the backup cell in the NGAP conversation belonging to the same UE with the switching preparation failure response message according to the value of the backup cell corresponding to the switching preparation failure response message, can realize the management of the NGAP conversation context, can more conveniently realize the conversation management of the NGAP protocol under the switching scene of the N2 interface in the 5G system, and has the advantages of simple and easy processing, high accuracy and strong practicability.

In order to facilitate understanding of the above embodiments of the present invention, the following describes a session management procedure in two cases of an N2 interface switching scenario.

For an Xn-based handoff scenario, the steps of the session management method may include:

(1) obtaining PATH SWITCH REQUEST information from a target NG-RAN to AMF, wherein parameters extracted from the information comprise AMF UE NGAP ID parameter, RAN UE NGAP ID parameter, TEID parameter and IP parameter of gNB, RAN IP address, AMF IP address, user location information including TAI, NGCI and PDU Session ID, searching Session context of all users according to AMF UE NGAP ID and AMF IP, if AMF UE NGAP ID and AMF IP value in the Session of the user are the same as the value in the information, representing the same user, backing up original value of cell used for searching the Session, updating RAN UE NGAP ID and RAN IP in the user Session, TEID and IP value of gNB, and user location information and PDU Session ID.

(2) Acquiring a response message from AMF to a target NG-RAN, if the response message is a successful response, obtaining a PATH SWITCH REQUEST ACKNOWLEDGE message, extracting AMF UE NGAP ID parameter, RAN UE NGAP ID parameter, TEID parameter and IP parameter of UPF, RAN IP address, AMF IP address and PDU Session ID from the message, searching Session context of all users according to RAN UE NGAP ID and RAN IP, if RAN UE NGAP ID and IP value in a Session of a user are the same as the value in the message, representing the same user, backing up original values of cells for searching the Session, and updating AMF UE NGAP ID and AMF IP in the Session of the user, TEID and IP values of UPF and PDU Session ID. And if the path switching fails, correlating the RAN UE NGAP ID and the RAN IP with the session of the same user, and recovering the TEID and the IP of the RAN UE NGAP ID, the RAN IP and the gNB which are backed up according to the path switching request message.

For an N2-based handoff scenario, the steps of the session management method may include:

(1) acquiring a HANDOVER REQUIRED message from a source NG-RAN to a source AMF, extracting parameters from the message, including AMF UE NGAP ID parameter, RAN UE NGAP ID parameter, TEID parameter and IP parameter of UPF, RAN IP address, AMF IP address and PDU Session ID, searching Session context of all users according to AMF UE NGAP ID and AMF IP, if AMF UE NGAP ID and IP value in a Session of a user are the same as the value in the message, representing the same user, backing up original value of cell used for searching the Session, and updating RAN UE NGAP ID and RAN IP in the user Session, TEID and IP value of UPF, and PDU Session ID.

(2) Acquiring a HANDOVER REQUEST message from a target NG-RAN to a target AMF, and acquiring parameters AMF UE NGAP ID, TEID and IP of UPF, AMF IP address and PDU Session ID from the message. According to the TEID and IP of the UPF, if the TEID and IP are the same as the TEID and IP values of the UPF in the HANDOVER REQUIRED message, the UPF is represented as the same user, the original value of the cell used for searching the Session in the updated parameters is backed up, and meanwhile, the values of the AMF UE NGAP ID and AMF IP in the user Session and the PDU Session ID are updated.

(3) If the HANDOVER resource allocation is successful, a HANDOVER REQUEST acknowledgement message from the destination AMF to the destination RAN is obtained, and parameters RAN UE NGAP ID, AMF UE NGAP ID, TEID and IP of gNB, RAN IP address, AMF IP address, and PDU Session ID can be obtained from the message. And associating the AMF UE NGAP ID and the AMF IP with the AMF UE NGAP ID and the AMF IP in the HANDOVER REQUEST message, if the same is the same user message, backing up the original value of the cell used for searching the Session in the updated parameters, and updating the RAN UE NGAP ID and the RAN IP in the user Session, the TEID and the IP value of the gNB and the PDU Session ID. And if the resource switching preparation fails, associating the AMF UE NGAP ID and the AMF IP with the session of the same user, and recovering the values of the AMF UE NGAP ID and the AMF IP backed up according to the resource allocation request message.

(4) If the HANDOVER resource allocation process is completed, a response message of a HANDOVER preparation message is received next, if the HANDOVER preparation is successful, a HANDOVER COMMAND message can be acquired, the message is not processed, if the HANDOVER preparation is failed, the NGAP session of the user is found through the source RAN UE NGAP ID and the RAN IP, and the TEID and IP of the UPF backed up according to the HANDOVER preparation request, and the values of the RAN ID and IP are restored.

(5) If the HANDOVER preparation and the HANDOVER resource allocation process are completed, a HANDOVER notification message, namely HANDOVER NOTIFY, sent by the destination NG-RAN to the destination AMF is received, in which the parameters of the destination AMF UE NGAP ID and RAN UE NGAP ID can be obtained, and the location information of the user includes TAI and NGCI, AMF IP and RAN IP. And if the NGAP session of the user is found through the AMF UE NGAP ID and AMF IP, backing up the original value of the updated cell, and meanwhile, the RAN UE NGAP ID, IP and the position information of the user in the user session.

The following describes the session management device in the N2 interface switching scenario provided in the embodiment of the present invention, and the session management device in the N2 interface switching scenario described below and the session management method in the N2 interface switching scenario described above may be referred to correspondingly.

Fig. 4 is a schematic structural diagram of a session management apparatus in an N2 interface handover scenario according to an embodiment of the present invention. Based on the content of the foregoing embodiments, as shown in fig. 4, the apparatus includes a user determination module 401 and a backup update module 402, where:

a user determining module 401, configured to obtain a session endpoint identifier and an IP address of a receiving end of a target NGAP message carried by the target NGAP message, and determine whether an NGAP session exists in the established NGAP session, where the session endpoint identifier and the IP address are the same as the session endpoint identifier and the IP address of the receiving end;

a backup updating module 402, configured to update, if the message type of the target NGAP message exists, a value of a target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end according to the message type of the target NGAP message;

the target NGAP message is an NGAP message in an N2 interface switching scene; a target information element corresponding to the message type.

Specifically, the user determination module 401 and the backup update module 402 are electrically connected.

The user judgment module 401 obtains the session endpoint identifier and the IP address of the opposite-end network element carried by the target NGAP message; and searching the established NGAP session according to the session endpoint identification and the IP address of the opposite-end network element, and determining whether the established NGAP session has the NGAP session belonging to the same UE as the target NGAP message.

The backup updating module 402 updates the current value of the target cell in the NGAP session belonging to the same UE as the target NGAP message to a new value or restores the current value to an old value according to the message type of the target NGAP message, so as to facilitate the session management for other target NGAP messages later.

It should be noted that the backup updating module 402 may be specifically configured to update the value of the target cell carried by the target NGAP message to an NGAP session in which the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end if the message type of the target NGAP message is a path switch request message, a path switch success response message, a switch preparation request message, a switch resource allocation success response message, or a switch notification message.

The backup updating module 402 may be specifically configured to backup a value of a backup cell carried by the target NGAP message if the message type of the target NGAP message is a path switch request message, a path switch success response message, a switch preparation request message, a switch resource allocation success response message, or a switch notification message;

wherein, the backup cell is a part of the target cell; and the backup cell is used for searching the conversation.

The backup updating module 402 may be specifically configured to restore, if the message type of the target NGAP message is the path switch failure response message, the value of the backup cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end, according to the value of the backup cell corresponding to the target NGAP message;

the value of the backup cell backed up corresponding to the target NGAP message is the value of the backup cell carried by the path switching request message corresponding to the target NGAP message.

The backup updating module 402 may be specifically configured to restore, according to a value of a backed-up backup cell corresponding to the target NGAP message, a value of a backup cell in an NGAP session in which a session endpoint identifier and an IP address in a context are the same as a session endpoint identifier and an IP address of a receiving end if the message type of the target NGAP message is a handover resource allocation failure response message;

The backup updating module 402 may be specifically configured to restore, according to a value of a backed-up backup cell corresponding to the target NGAP message, a value of a backup cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end if the message type of the target NGAP message is a handover preparation failure response message;

The specific method and process for implementing the corresponding function by each module included in the session management device in the N2 interface switching scenario provided in the embodiments of the present invention are detailed in the embodiment of the session management method in the N2 interface switching scenario, and are not described herein again.

The session management device in the N2 interface switching scenario is used in the session management method in the N2 interface switching scenario of the foregoing embodiments. Therefore, the description and definition in the session management method under the N2 interface switching scenario in the foregoing embodiments may be used for understanding each execution module in the embodiments of the present invention.

Fig. 5 illustrates a physical structure diagram of an electronic device, which may include, as shown in fig. 5: a processor (processor) 501, a memory (memory) 502, and a bus 503; the processor 501 and the memory 502 complete communication with each other through a bus 503; the processor 501 is configured to invoke computer program instructions stored in the memory 502 and executable on the processor 501 to perform a session management method in an N2 interface switching scenario provided by the above-mentioned method embodiments, where the method includes: acquiring a session endpoint identifier and an IP address of a receiving end of a target NGAP message carried by the target NGAP message, and judging whether an NGAP session with the same session endpoint identifier and IP address as those of the receiving end exists in the established NGAP session or not; if yes, updating the value of the target cell in the NGAP conversation, wherein the conversation endpoint identification and the IP address in the context are the same as the conversation endpoint identification and the IP address of the receiving end, according to the message type of the target NGAP message; the target NGAP message is an NGAP message in an N2 interface switching scene; a target information element corresponding to the message type.

Furthermore, the logic instructions in the memory 502 may be implemented in the form of software functional units and stored in a computer readable storage medium when the software functional units are sold or used as independent products. Based on such understanding, the technical solution of the present invention or a part thereof which substantially contributes to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

In another aspect, an embodiment of the present invention further provides a computer program product, where the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, where the computer program includes program instructions, and when the program instructions are executed by a computer, the computer is capable of executing the session management method in the N2 interface switching scenario provided by the foregoing method embodiments, where the method includes: acquiring a session endpoint identifier and an IP address of a receiving end of a target NGAP message carried by the target NGAP message, and judging whether an NGAP session with the same session endpoint identifier and IP address as those of the receiving end exists in the established NGAP session or not; if yes, updating the value of the target cell in the NGAP session, wherein the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end, according to the message type of the target NGAP message; the target NGAP message is an NGAP message in an N2 interface switching scene; a target information element corresponding to the message type.

In another aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored, where the computer program is implemented to, when executed by a processor, perform a session management method in an N2 interface switching scenario provided in the foregoing embodiments, where the method includes: acquiring a session endpoint identifier and an IP address of a receiving end of a target NGAP message carried by the target NGAP message, and judging whether an NGAP session with the same session endpoint identifier and IP address as those of the receiving end exists in the established NGAP session or not; if yes, updating the value of the target cell in the NGAP conversation, wherein the conversation endpoint identification and the IP address in the context are the same as the conversation endpoint identification and the IP address of the receiving end, according to the message type of the target NGAP message; the target NGAP message is an NGAP message in an N2 interface switching scene; a target information element corresponding to the message type.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. Based on the understanding, the above technical solutions substantially or otherwise contributing to the prior art may be embodied in the form of a software product, which may be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the various embodiments or some parts of the embodiments.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A session management method under an N2 interface switching scene is characterized by comprising the following steps:

acquiring a session endpoint identifier and an IP address of a receiving end of the target NGAP message carried by the target NGAP message, and judging whether an NGAP session with the same session endpoint identifier and IP address in the context as those of the receiving end exists in the established NGAP session or not; the session endpoint identifier and the IP address of the receiving end are the session endpoint identifier and the IP address of the control plane and/or the data plane of the receiving end;

if yes, updating the value of the target cell in the NGAP session, wherein the session endpoint identifier and the IP address in the context of the target cell are the same as the session endpoint identifier and the IP address of the receiving end;

2. The session management method in the N2 interface handover scenario according to claim 1, wherein the message type includes at least one of a path handover request message, a path handover response message, a handover preparation request message, a handover resource allocation response message, a handover preparation response message, and a handover notification message; wherein the response message comprises a success response message and a failure response message.

3. The session management method under the N2 interface switching scenario according to claim 2, wherein the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end according to the message type of the target NGAP message includes:

4. The session management method under the N2 interface switching scenario according to claim 3, wherein the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end according to the message type of the target NGAP message further comprises:

wherein the backup cell is a part of the target cell; the backup cell is used for searching for the conversation.

5. The session management method under the N2 interface switching scenario according to claim 4, wherein the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end according to the message type of the target NGAP message further comprises:

if the message type of the target NGAP message is a path switching failure response message, restoring the value of the backup cell in the NGAP session, wherein the session endpoint identifier and the IP address in the context of the backup cell are the same as the session endpoint identifier and the IP address of the receiving end, according to the value of the backup cell corresponding to the target NGAP message;

6. The session management method under the N2 interface switching scenario according to claim 4, wherein the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end according to the message type of the target NGAP message further comprises:

if the message type of the target NGAP message is a switching resource allocation failure response message, restoring the value of the backup cell in the NGAP session, wherein the session endpoint identifier and the IP address in the context of the backup cell are the same as the session endpoint identifier and the IP address of the receiving end, according to the value of the backup cell corresponding to the target NGAP message;

the backed-up value of the backup cell corresponding to the target NGAP message is the value of the backup cell carried by the handover resource allocation request message corresponding to the target NGAP message.

7. The session management method under the scenario of switching N2 interfaces according to any of claims 4 to 6, wherein the specific step of updating the value of the target cell in the NGAP session where the session endpoint identifier and the IP address in the context are the same as the session endpoint identifier and the IP address of the receiving end according to the message type of the target NGAP message further comprises:

if the message type of the target NGAP message is a switching preparation failure response message, restoring the value of the backup cell in the NGAP session, wherein the session endpoint identifier and the IP address in the context of the backup cell are the same as the session endpoint identifier and the IP address of the receiving end, according to the value of the backup cell corresponding to the target NGAP message and backed up;

8. A session management device under an N2 interface switching scene is characterized by comprising:

the user judgment module is used for acquiring the session endpoint identifier and the IP address of the receiving end of the target NGAP message carried by the target NGAP message, and judging whether the established NGAP session has the session endpoint identifier and the IP address which are the same as the session endpoint identifier and the IP address of the receiving end in the context; the session endpoint identifier and the IP address of the receiving end are the session endpoint identifier and the IP address of the control plane and/or the data plane of the receiving end;

a backup updating module, configured to update, if the message type of the target NGAP message exists, a value of a target cell in an NGAP session where a session endpoint identifier and an IP address in a context are the same as a session endpoint identifier and an IP address of the receiving end;

9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program implements the steps of the session management method in the context of an N2 interface switch as claimed in any one of claims 1 to 7.

10. A non-transitory computer readable storage medium, on which a computer program is stored, which, when being executed by a processor, implements the steps of the session management method in an N2 interface switching scenario according to any one of claims 1 to 7.