CN115190649A - Method, device and system for session control - Google Patents

Abstract

The present application provides a session control method, apparatus and system, which can avoid session and service interruption of a terminal device and ensure the session and service continuity of the terminal device. Specifically, first, the first network element receives the session attribute information of the first session that the terminal device requests to establish; then, the first network element receives the session attribute information of the second session of the terminal device previously established and the session of the first session attribute information, to determine that the establishment of the first session is allowed; wherein, the first session is a new session corresponding to the second session, and the session attribute information of the first session and the session attribute information of the second session include the same identification information of the terminal device , network slice identification information, and data network information.

Description

Method, device and system for session control

technical field

The present application relates to the field of communications, and more particularly, to a method, apparatus and system for session control.

Background technique

In the 5G communication system, the network elements in the core network will limit the number of sessions in the network slice according to the customer's order. After the number of sessions in the network slice reaches or exceeds the maximum number of sessions allowed to be established in the network slice, the relevant network The element will reject the session establishment request from the client's end device. However, when the terminal device needs to change the session anchor point of the protocol data unit (PDU) due to the location movement, the terminal device will release the original session and establish a new session. The number of sessions in the slice is limited, and the service interruption of the terminal device is caused, which affects the session and service continuity of the terminal device.

SUMMARY OF THE INVENTION

The present application provides a session control method, apparatus and system, which can avoid session and service interruption of terminal equipment and ensure the session and service continuity of terminal equipment.

In a first aspect, a session control method is provided, the method comprising: a first network element receiving session attribute information of a first session requested by a terminal device to establish; The session attribute information of the second session and the session attribute information of the first session determine that the establishment of the first session is allowed; wherein the first session is a new session corresponding to the second session, and the The session attribute information of the first session and the session attribute information of the second session include the same identification information of the terminal device, network slice identification information, and data network information.

According to the method provided by the present application, after the first network element determines that the first session is a new session corresponding to the second session, the first network element allows the establishment of the first session, and no longer judges that the network slicing after the establishment of the first session is accepted. Whether the number of established sessions in the network exceeds the maximum number of sessions allowed to be established in the network slice, or the establishment of the first session is no longer restricted according to the session quota in the network slice, thereby avoiding the second session of the terminal device to change the PDU session anchor Point failure and interruption of sessions and services of terminal devices ensure the continuity of sessions and services of terminal devices.

It should be understood that the session quota of the network slice refers to the number of sessions allowed by the first network element to be established within the range of the maximum number of sessions of the network slice. When there are multiple first network element entities to control the maximum number of sessions allowed to be established in the network slice, the sum of session quotas in the network slice of each first network element entity is less than or equal to the maximum number of sessions allowed to be established in the network slice.

With reference to the first aspect, in some implementations of the first aspect, the session attribute information of the first session and the session attribute information of the second session further include the same session and service continuity mode SSC mode parameters.

With reference to the first aspect, in some implementations of the first aspect, the first session is a new one in which the session anchor of the protocol data unit (PDU) needs to be changed for the second session due to the session and business continuity of the terminal device. session, the first session and the second session are SSC mode 2 sessions or SSC mode 3 sessions; the first network element determines that the establishment of the first session is allowed, including: the first network element It is determined to skip the check of the number of sessions in the network slice corresponding to the network slice identifier, that is, it is no longer judged whether the number of established sessions in the network slice after accepting the establishment of the first session exceeds the maximum number of sessions allowed to be established in the network slice, Or, it is determined that the establishment of the first session is permitted without judging whether the session quota of the network slice is exceeded after accepting the first session.

With reference to the first aspect, in some implementations of the first aspect, the session attribute information of the second session is used to indicate that: establishment of the first session is not restricted; or, a quota is reserved for the first session , that is, to prevent the number of established sessions in the network slice from reaching or exceeding the maximum number of sessions allowed to be established in the network slice after accepting the establishment of other new sessions, reserve at least a quota for the number of sessions in the network slice, and wait for the first session to be established. or, the establishment of the first session occupies the session quota of the second session, that is, the session quota of the second session of the just released SSC mode2 is reserved for use when the first session is established, Or let the session quota of the second session to be released be used when the first session of SSC mode3 is established.

With reference to the first aspect, in some implementations of the first aspect, the first network element determines a valid timer for session attribute information of the second session, and the valid timer indicates a session of the second session Valid time for attribute information.

By determining a valid timer for the attribute information of the second session, after the valid timer expires, the session attribute information of the second session is deleted, so as to avoid erroneously judging other subsequent sessions as the first session.

With reference to the first aspect, in some implementations of the first aspect, the first network element is a network slice admission control function NSACF entity, and the first network element receives the session attribute of the first session requested by the terminal device to establish information, the method further includes: the NSACF entity receives a first message from a first session management network element, the first session management network element is a session management network element corresponding to the second session, the first session management network element The message includes session attribute information of the second session of the terminal device; the NSACF entity stores the session attribute information of the second session.

With reference to the first aspect, in some implementations of the first aspect, the first message is used to: check the number of sessions in the network slice corresponding to the network slice identifier, or update the network slice corresponding to the network slice identifier The number of sessions in the slice, or the session quota in the network slice corresponding to the network slice identifier is reserved.

With reference to the first aspect, in some implementations of the first aspect, the receiving, by the first network element, the session attribute information of the first session requested by the terminal device to establish includes: the NSACF entity receiving from the second session management network element a second message, the second session management network element is the network element corresponding to the first session, the second message includes session attribute information of the first session of the terminal device, and the second message uses For inquiring whether to allow the establishment of the first session, or for updating the number of sessions in the network slice corresponding to the network slice identifier, or for inquiring whether to allow the establishment of the first session to occupy the second session Session quota.

With reference to the first aspect, in some implementations of the first aspect, the first network element is a policy control network element, and before the first network element receives the session attribute information of the first session requested by the terminal device to establish, The method further includes: the policy control network element receiving a third message from a first session management network element, the first session management network element being a session management network element corresponding to the second session, the third message The session attribute information of the second session of the terminal device is included; the policy control network element saves the session attribute information of the second session.

With reference to the first aspect, in some implementations of the first aspect, the third message is used to: report an update of the session management policy association of the second session, or request establishment of session management for the second session Policy association, or, notifying an update of the session management policy association that controls the second session, or requesting deletion of the session management policy association of the second session.

With reference to the first aspect, in some implementations of the first aspect, the receiving, by the first network element, the session attribute information of the first session requested by the terminal device to establish includes: the policy control network element obtains information from the second session management network element receives a fourth message, the second session management network element is the session management network element corresponding to the first session, the fourth message includes the session attribute information of the first session of the terminal device, and the The fourth message is used to request to establish a session management policy association of the first session.

With reference to the first aspect, in some implementations of the first aspect, before the policy control network element receives the third message from the first session management network element, the method further includes: the policy control network element receives the NSACF The intra-slice session quota allocated by the entity.

With reference to the first aspect, in some implementations of the first aspect, the first network element is an access and mobility management network element, and the first network element receives the session attribute of the first session requested by the terminal device to establish The method further includes: acquiring, by the access and mobility management network element, session attribute information of the second session.

With reference to the first aspect, in some implementations of the first aspect, the receiving, by the first network element, the session attribute information of the first session requested by the terminal device to establish, includes: the access and mobility management network element obtains information from the The terminal device receives a session establishment request message, where the session establishment request message includes session attribute information of the first session, and the session establishment request message requests establishment of the first session.

In a second aspect, a session control method is provided, the method comprising: a second network element sending first indication information to a terminal device, where the first indication information is used to instruct the terminal device to establish a first session, Or, the first indication information is used to instruct the terminal device to release the second session and establish the first session; the second network element sends the session attribute information of the second session to the first network element, The session attribute information of the second session is used by the first network element to determine that the establishment of the first session is permitted; wherein the first session is a new session corresponding to the second session, and the first session is a new session corresponding to the second session. The session attribute information of one session and the session attribute information of the second session include the same identification information of the terminal device, network slice identification information, and data network information.

According to the method provided by the present application, the second network element provides the first network element with session attribute information of the second session when the first session is established, and the session attribute information of the second session is used by the first network element to determine permission The establishment of the first session, and the first network element will no longer judge whether the number of established sessions in the network slice after accepting the first session exceeds the maximum number of sessions allowed to be established in the network slice, or will no longer be based on the session quota of the network slice. The establishment of the first session is restricted, thereby avoiding failure of the second session of the terminal device to change the PDU session anchor and interruption of the session and service of the terminal device, and ensuring the continuity of the session and service of the terminal device.

With reference to the second aspect, in some implementations of the second aspect, the session attribute information of the first session and the session attribute information of the second session further include the same session and service continuity mode SSC mode parameters.

With reference to the second aspect, in some implementations of the second aspect, the first session is a new one in which the session anchor of the protocol data unit (PDU) needs to be changed for the second session due to the session and business continuity of the terminal device. session, the first session and the second session are SSC mode 2 sessions or SSC mode 3 sessions; the session attribute information of the second session is used by the first network element to determine whether the first session is allowed The establishment of the second session includes: using the session attribute information of the second session for the first network element to determine to skip the check of the number of sessions in the network slice corresponding to the network slice identifier, and to determine that the establishment of the first session is allowed.

With reference to the second aspect, in some implementations of the second aspect, the first network element is a network slice admission control function NSACF entity, the second network element is a first session management network element, and the second network element is a sending the session attribute information of the second session to the first network element, including: the first session management network element sending a first message to the NSACF entity, where the first session management network element is the second session management network element. A session management network element corresponding to the session, and the first message includes session attribute information of the second session.

With reference to the second aspect, in some implementations of the second aspect, the first message is used to: check the number of sessions in the network slice corresponding to the network slice identifier, or update the network slice corresponding to the network slice identifier The number of sessions in the slice, or the reserved quota of sessions in the network slice corresponding to the network slice identifier.

With reference to the second aspect, in some implementations of the second aspect, the first network element is a policy control network element, the second network element is a first session management network element, and the second network element reports to the first network element. Sending the session attribute information of the second session by a network element includes: the first session management network element sends a third message to the policy control network element, where the first session management network element is the second session For a corresponding session management network element, the third message includes session attribute information of the second session.

With reference to the second aspect, in some implementations of the second aspect, the third message is used to: report an update of the session management policy association of the second session, or request establishment of session management for the second session Policy association, or, notifying an update of the session management policy association that controls the second session, or requesting deletion of the session management policy association of the second session.

In a third aspect, an apparatus for session control is provided, and the apparatus may be a core network device or a chip used for the core network device. The apparatus has the functionality to implement the behavior in the method example of the first aspect above. The functions can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In a possible design, the apparatus includes a transceiving unit and a processing unit, the transceiving unit is configured to receive session attribute information of a first session requested by a terminal device to be established; the processing unit is configured to The session attribute information of the second session of the device and the session attribute information of the first session determine that the establishment of the first session is allowed; wherein, the first session is a new session corresponding to the second session, The session attribute information of the first session and the session attribute information of the second session include the same identification information of the terminal device, network slice identification information, and data network information.

These modules can perform the corresponding functions in the method examples of the first aspect. For details, please refer to the detailed descriptions in the method examples, which will not be repeated here.

In a fourth aspect, an apparatus for session control is provided, and the apparatus may be a core network device or a chip used for the core network device. The apparatus has the functionality to implement the behavior in the method example of the second aspect above. The functions can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In a possible design, the apparatus includes a transceiving unit, and the transceiving unit is configured to send first indication information to the terminal device, where the first indication information is used to indicate the establishment of the first session of the terminal device, or , the first indication information is used to indicate the release of the second session of the terminal device and the establishment of the first session; the transceiver unit is further configured to send the session attribute information of the second session to the first network element, The session attribute information of the second session is used by the first network element to determine that the establishment of the first session is permitted; wherein the first session is a new session corresponding to the second session, and the first session is a new session corresponding to the second session. The session attribute information of one session and the session attribute information of the second session include the same identification information of the terminal device, network slice identification information, and data network information.

These modules can perform the corresponding functions in the method examples of the second aspect. For details, please refer to the detailed descriptions in the method examples, which will not be repeated here.

In a fifth aspect, a session control system is provided, the system includes a first network element, a terminal device; the first network element is configured to receive session attribute information of a first session requested by the terminal device to be established; The first network element is further configured to determine to allow the establishment of the first session according to the session attribute information of the second session of the terminal device and the session attribute information of the first session previously established; wherein, the first session is allowed to be established; A session is a new session corresponding to the second session, the session attribute information of the first session and the session attribute information of the second session include the same identification information of the terminal device and network slice identification information, and data network information.

According to the system provided by the present application, after the first network element determines that the first session is a new session corresponding to the second session, the first network element allows the establishment of the first session, and no longer controls the first session according to the session quota in the network slice. The establishment of the session is restricted, thereby avoiding the failure of the second session of the terminal device to change the PDU session anchor, and the interruption of the session and service of the terminal device, thereby ensuring the continuity of the session and service of the terminal device.

With reference to the fifth aspect, in some implementations of the fifth aspect, the session attribute information of the first session and the session attribute information of the second session further include the same session and service continuity mode SSC mode parameters.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first session is a new one in which the session anchor of the protocol data unit (PDU) needs to be changed for the second session due to the session and business continuity of the terminal device. session, the first session and the second session are SSC mode 2 sessions or SSC mode 3 sessions; the first network element is used to determine that the establishment of the first session is allowed, and the first network element It is specifically used for: determining to skip the check of the number of sessions in the network slice corresponding to the network slice identifier, and determining to allow establishment of the first session.

With reference to the fifth aspect, in some implementations of the fifth aspect, the session attribute information of the second session is used to indicate that: establishment of the first session is not restricted; or, a quota is reserved for the first session ; or, the establishment of the first session occupies the session quota of the second session.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first network element is further configured to determine a valid timer for the session attribute information of the second session, where the valid timer indicates the second session Valid time of session attribute information for the session.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first network element is a network slice admission control function NSACF entity, and the system further includes a first session management network element, the first session management network The element is a session management network element corresponding to the second session. Before the first network element is used to receive the session attribute information of the first session requested by the terminal device to be established, the first network element is further used for: Receive a first message from the first session management network element, where the first message includes session attribute information of the second session of the terminal device; save the session attribute information of the second session.

In a possible implementation manner, the NSACF entity of the network slice admission control function determines that session attribute information of the second session exists from the stored attribute information of each session, wherein the session attribute information of the second session includes the same information as the session attribute information of the second session. The same terminal equipment identification information, network slice identification information, data network information, and optionally the same SSC mode parameter as the first session, the network slice admission control function NSACF entity determines that the first session is the same as the first session. The new session corresponding to the second session.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first message is used to: check the number of sessions in the network slice corresponding to the network slice identifier, or update the network slice corresponding to the network slice identifier The number of sessions in the slice, or the session quota in the network slice corresponding to the network slice identifier is reserved.

With reference to the fifth aspect, in some implementations of the fifth aspect, the system further includes a second session management network element, where the second session management network element is a network element corresponding to the first session, and the second session management network element is a network element corresponding to the first session. A network element is configured to receive session attribute information of the first session requested by the terminal device to establish, and the first network element is specifically configured to: receive a second message from the second session management network element, the second message Including session attribute information of the first session of the terminal device, the second message is used to inquire whether to allow the establishment of the first session, or to update the session in the network slice corresponding to the network slice identifier The number, or for inquiring whether the establishment of the first session is allowed to occupy the session quota of the second session.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first network element is a policy control network element, and the system further includes a first session management network element, and the first session management network element is the the session management network element corresponding to the second session, before the first network element is used to receive the session attribute information of the first session requested by the terminal device to establish, the policy control network element is further configured to: The first session management network element receives a third message, where the third message includes session attribute information of the second session of the terminal device; and saves the session attribute information of the second session.

In a possible implementation manner, the policy control network element determines that session attribute information of the second session exists from the saved session attribute information, wherein the session attribute information of the second session includes the same information as the first session attribute information. The same terminal equipment identification information, network slice identification information, data network information, and optionally the same SSC mode parameter as the session, the policy control network element determines that the first session is a new one corresponding to the second session. session.

With reference to the fifth aspect, in some implementations of the fifth aspect, the third message is used to: report an update of the session management policy association of the second session, or request establishment of session management for the second session Policy association, or, notifying an update of the session management policy association that controls the second session, or requesting deletion of the session management policy association of the second session.

With reference to the fifth aspect, in some implementations of the fifth aspect, the system further includes a second session management network element, where the second session management network element is a network element corresponding to the first session, and the second session management network element is a network element corresponding to the first session. A network element is configured to receive session attribute information of the first session requested by the terminal device to establish, and the policy control network element is specifically configured to: receive a fourth message from the second session management network element, the fourth message The session attribute information of the first session of the terminal device is included, and the fourth message is used to request the establishment of a session management policy association of the first session.

With reference to the fifth aspect, in some implementations of the fifth aspect, before the policy control network element is configured to receive the third message from the first session management network element, the policy control network element is further configured to: receive the NSACF The intra-slice session quota allocated by the entity.

With reference to the fifth aspect, in some implementation manners of the fifth aspect, the first network element is an access and mobility management network element, and the first network element is configured to receive a first network element that the terminal device requests to establish. Before the session attribute information of the session, the access and mobility management network element is further configured to: acquire the session attribute information of the second session.

In a possible implementation manner, the access and mobility management network element stores session attribute information of the second session. The access and mobility management network element determines that session attribute information of the second session exists from the saved session attribute information, wherein the session attribute information of the second session includes the same terminal device as the first session. identification information, network slice identification information, data network information, and optionally the same SSC mode parameter, the access and mobility management network element determines that the first session is a new session corresponding to the second session.

With reference to the fifth aspect, in some implementations of the fifth aspect, the first network element is configured to receive session attribute information of the first session requested by the terminal device to establish, and the access and mobility management network element is specifically is used for: receiving a session establishment request message from the terminal device, where the session establishment request message includes session attribute information of the first session, and the session establishment request message requests establishment of the first session.

In a sixth aspect, a method for session control is provided, the method comprising: a fourth network element receiving first information from a terminal device, where the first information is used to request establishment of a first session of the terminal device, the The first information includes the identification information of the second session of the terminal device, wherein the first session is the second session because the session and business continuity of the terminal device needs to change the protocol data unit PDU session anchor point. a new session, the first session and the second session are established in the same network slice; the fourth network element determines the number of sessions skipped in the network slice according to the identification information of the second session Check and determine that the establishment of the first session is allowed.

According to the method provided by the present application, after receiving the request message of the first session and the identification information of the second session, the fourth network element can determine that the first session is a new session corresponding to the second session after changing the PDU session anchor. At this time, the fourth network element will not check whether the number of sessions in the network slice reaches or exceeds the session quota in the network slice, and allows the establishment of the first session, thus avoiding that the number of sessions in the current network slice has reached or exceeded the network slice. When the session quota is used, if the first session cannot be established, the terminal device can successfully modify the PDU session anchor, and the continuity of the session and service of the terminal device can be ensured.

With reference to the sixth aspect, in some implementation manners of the sixth aspect, the fourth network element is an access and mobility management network element, and the fourth network element receives the first information from the terminal device, including: the access and mobility management network element. The inbound and mobility management network element receives a session establishment request message from the terminal device, and the session establishment request message includes the first information.

With reference to the sixth aspect, in some implementations of the sixth aspect, the fourth network element is a session management network element, and the fourth network element receives the first information from the terminal device, including: the session management network element Receive a create session context request message from a first access and mobility management network element, where the first access and mobility management network element is an access and mobility management network element corresponding to the first session, and the create session context request message The message includes the first information.

With reference to the sixth aspect, in some implementations of the sixth aspect, the fourth network element is a policy control network element, and the fourth network element receives the first information from the terminal device, including: the policy control network element Receive a create session management policy association request message from a third session management network element, where the third session management network element is a session management network element corresponding to the first session, and the create session management policy association request message includes the first session management policy association request message. a message.

In a seventh aspect, an apparatus for session control is provided, and the apparatus may be a core network device or a chip used for the core network device. The apparatus has the function of implementing the behavior in the method example of the sixth aspect above. The functions can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In a possible design, the apparatus includes a transceiving unit and a processing unit, the transceiving unit is configured to receive first information from a terminal device, and the first information is used to request the establishment of a first session of the terminal device, The first information includes identification information of the second session of the terminal device, wherein the first session is the second session because the session and business continuity of the terminal device needs to change the protocol data unit PDU session anchor. The first session and the second session are established in the same network slice; the processing unit is configured to determine to skip the network slice according to the identification information of the second session. The number of sessions is checked and it is determined that the establishment of the first session is allowed.

These modules can perform the corresponding functions in the method examples of the sixth aspect. For details, please refer to the detailed descriptions in the method examples, which will not be repeated here.

In an eighth aspect, a session control system is provided, the system includes: a fourth network element, a terminal device; the fourth network element is configured to receive first information from the terminal device, and the first information is used for In order to request the establishment of the first session of the terminal device, the first information includes identification information of the second session of the terminal device, wherein the first session is the second session due to the Session and business continuity need to change the new session of the protocol data unit PDU session anchor point, the first session and the second session are established in the same network slice; the fourth network element is also used for according to the The identification information of the second session is determined to skip the check of the number of sessions in the network slice, and the establishment of the first session is determined to be allowed.

With reference to the eighth aspect, in some implementations of the eighth aspect, the fourth network element is an access and mobility management network element, and the fourth network element is configured to receive the first information from the terminal device, including : the access and mobility management network element receives a session establishment request message from the terminal device, where the session establishment request message includes the first information.

With reference to the eighth aspect, in some implementations of the eighth aspect, the fourth network element is a session management network element, and the fourth network element is configured to receive the first information from the terminal device, including: the The session management network element receives a create session context request message from a first access and mobility management network element, where the first access and mobility management network element is an access and mobility management network element corresponding to the first session, and the first access and mobility management network element is an access and mobility management network element corresponding to the first session. The create session context request message includes the first information.

With reference to the eighth aspect, in some implementations of the eighth aspect, the fourth network element is a policy control network element, and the fourth network element is configured to receive the first information from the terminal device, including: the The policy control network element receives a create session management policy association request message from a third session management network element, where the third session management network element is a session management network element corresponding to the first session, and the create session management policy association request message including the first information.

In a ninth aspect, an apparatus is provided that includes a processor and a transceiver. The processor is connected to the transceiver. The processor is used to execute instructions, and the transceiver is used to communicate with other network elements under the control of the processor. When the processor executes the instructions, the execution causes the apparatus to perform any of the above aspects or a method in any possible implementation of any of the aspects. The apparatus also includes a memory for storing the instructions.

In a tenth aspect, a computer-readable medium is provided, the computer-readable medium is stored with a computer program (also referred to as code, or instruction), when it runs on a computer, causing the computer to perform any aspect or any one of the above A method in any possible implementation of an aspect.

In an eleventh aspect, a communication chip is provided, in which instructions are stored that, when executed on a computer device, cause the communication chip to perform the method in any of the above-mentioned aspects or any possible implementation manner of any of the aspects.

A twelfth aspect provides a computer program product comprising instructions, the instructions, when run on a computer, cause the computer to perform any of the above aspects or the method in any possible implementation of any of the aspects.

A thirteenth aspect provides a chip system, comprising: an input interface, an output interface, at least one processor, and a memory, wherein the input interface, the output interface, the processor, and the memory are connected through an internal connection path, The processor is configured to execute code in the memory, and when the code is executed, the processor is configured to execute the methods of the above aspects.

Based on the above technical solutions, service interruption of the terminal device can be avoided, and the session and service continuity of the terminal device can be ensured. .

Description of drawings

Figure 1 is a schematic diagram of the architecture of a 5G mobile communication system;

2 is a schematic flowchart of a method for session control provided by the present application;

3 is a schematic flowchart of a method for session control provided by the present application;

4 is a schematic flowchart of a specific example of a method for session control provided by the present application;

5 is a schematic flowchart of a specific example of a method for session control provided by the present application;

6 is a schematic flowchart of another session control method provided by the present application;

7 is a schematic structural diagram of an apparatus for session control provided by the present application;

FIG. 8 is a schematic structural diagram of another apparatus for session control provided by the present application.

Detailed ways

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

The technical solutions of the embodiments of the present application can be applied to various communication systems, for example, a Global System of Mobile communication (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (Wideband) system Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (Long Term Evolution, LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (Time Division Duplex, TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, fifth generation (5th Generation, 5G) system, new wireless ( NewRadio, NR) or other communication systems that may appear in the future.

FIG. 1 shows a schematic diagram of a network architecture of a communication system to which an embodiment of the present application is applied. The network architecture includes a terminal device, an access network device, an access management network element, a session management network element, a user plane network element, and a policy Control network element, network slice selection network element, network warehouse function network element, network data analysis network element, unified data management network element, unified data storage network element, authentication service function network element, network capability opening network element, application function network element , and a data network (DN) and a charging function network element connected to the operator's network. The terminal equipment can send service data to the data network and receive service data from the data network through the access network equipment and user plane network elements.

Among them, the terminal device is a device with wireless transceiver function, which can be deployed on land, including indoor or outdoor, handheld, wearable or vehicle-mounted; it can also be deployed on water (such as ships, etc.); it can also be deployed in the air (such as Aircraft, balloons, satellites, etc. The terminal device can communicate with the core network via a radio access network (RAN), and exchange voice and/or data with the RAN. The terminal device can be a mobile phone (mobile phone) ), tablet computer (Pad), computer with wireless transceiver function, mobile internet device (MID), wearable device, virtual reality (VR) terminal device, augmented reality (AR) terminal equipment, wireless terminals in industrial control, wireless terminals in self driving, wireless terminals in remote medical, wireless terminals in smart grid, transportation security ( Wireless terminals in transportation safety), wireless terminals in smart cities, wireless terminals in smart homes, etc. The embodiments of this application do not limit application scenarios. Terminal equipment may also be called For user equipment (user equipment, UE), a mobile station, a remote station, etc., the embodiments of this application do not limit the specific technology, device form, and name used by the terminal equipment.

An access network device is a device in the network that is used to connect a terminal device to a wireless network. The access network device may be a node in a radio access network, may also be called a base station, may also be called an access network (access network, AN), and may also be called a radio access network (radio access network, RAN) ) node (or device). The network equipment may include an evolved base station (NodeB or eNB or e-NodeB, evolutional Node B) in a long term evolution (long term evolution, LTE) system or an evolved LTE system (LTE-Advanced, LTE-A), such as traditional The macro base station eNB and the micro base station eNB in the heterogeneous network scenario, or may also include the next generation node B (next generation node B) in the fifth generation mobile communication technology (5th generation, 5G) new radio (new radio, NR) system , gNB), or may also include radio network controller (radio network controller, RNC), Node B (Node B, NB), base station controller (basestation controller, BSC), base transceiver station (base transceiver station, BTS), Transmission reception point (transmission reception point, TRP), home base station (for example, home evolved NodeB, or homeNode B, HNB), base band unit (base band unit, BBU), baseband pool BBU pool, or WiFi access point (access point, AP), etc., or may also include a centralized unit (centralized unit, CU) and a distributed unit (distributed unit, DU) in a cloud radio access network (cloud radio access network, CloudRAN) system, the embodiment of the present application does not limited. In a separate deployment scenario where the access network equipment includes CU and DU, the CU supports radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (service data adaptation protocol) , SDAP) and other protocols; DU mainly supports radio link control layer (radio link control, RLC), media access control layer (media access control, MAC) and physical layer protocols.

The access management network element is mainly used for terminal attachment, mobility management, and tracking area update procedures in the mobile network. The access management network element terminates non-access stratum (NAS) messages, completes registration management, Connection management and reachability management, allocation of track area list (TA list) and mobility management, etc., and transparent routing of session management (SM) messages to session management network elements. In the fifth generation (5th generation, 5G) communication system, the access management network element may be an access and mobility management function (AMF). In future communication systems (such as 6G communication systems), mobile The property management network element may still be the AMF network element, or may have other names, which are not limited in this application.

The session management network element is mainly used for session management in the mobile network, such as session establishment, modification and release. Specific functions include allocating an Internet Protocol (IP) address to a terminal, selecting a user plane network element that provides a packet forwarding function, and the like. In a 5G communication system, the session management network element may be a session management function (SMF). In a future communication system (such as a 6G communication system), the session management network element may still be an SMF network element, or may also have Other names are not limited in this application.

User plane NEs are mainly used to process user packets, such as forwarding, accounting, and lawful interception. The user plane network element may also be referred to as a protocol data unit (protocol data unit, PDU) session anchor (PDU session anchor, PSA). In a 5G communication system, a user plane network element may be a user plane function (UPF). In a future communication system (such as a 6G communication system), the user plane network element may still be a UPF network element, or it may be With other names, this application is not limited.

The policy control network element includes user subscription data management function, policy control function, charging policy control function, quality of service (quality of service, QoS) control, and the like. In a 5G communication system, the policy control network element may be a policy control function (PCF). In a future communication system (such as a 6G communication system), the policy control network element may still be a PCF network element, or it may be With other names, this application is not limited.

The network slice selection function network element is mainly used to select the appropriate network slice for the service of the terminal device. In the 5G communication system, the network slice selection network element may be a network slice selection function (NSSF) network element. In future communication systems (such as 6G communication systems), the network slice selection network element may still be an NSSF network element. element, or may have other names, which is not limited in this application.

The network warehouse function network element is mainly used to provide the registration and discovery functions of the network element or the services provided by the network element. In a 5G communication system, the network warehouse function network element may be a network repository function (NRF), and in a future communication system (such as a 6G communication system), the network warehouse function network element may still be an NRF network element, or It can also have other names, which is not limited in this application.

Network data analysis network elements can be analyzed from various network functions (network function, NF), such as policy control network elements, session management network elements, user plane network elements, access management network elements, and application function network elements (through the network capability opening function). network elements) to collect data and make analysis and predictions. In the 5G communication system, the network data analysis network element may be a network data analysis function (NWDAF). In the future communication system (such as a 6G communication system), the network data analysis network element may still be an NWDAF network element. , or may have other names, which are not limited in this application.

The unified data management network element is mainly used to manage the subscription information of terminal equipment. In a 5G communication system, the unified data management network element may be a unified data management (UDM) network element. In a future communication system (such as a 6G communication system), the unified data management network element may still be a UDM network element, or It can also have other names, which is not limited in this application.

The unified data storage network element is mainly used to store structured data information, including subscription information, policy information, and network data or service data defined in a standard format. In a 5G communication system, the unified data storage network element may be a unified data repository (UDR). In a future communication system (such as a 6G communication system), the unified data storage network element may still be a UDR network element, or It can also have other names, which is not limited in this application.

The authentication service function network element is mainly used to perform security authentication on terminal equipment. In a 5G communication system, the authentication service function network element may be an authentication server function (AUSF). In a future communication system (such as a 6G communication system), the authentication service function network element may still be an AUSF network element, or It can also have other names, which is not limited in this application.

The network capability exposure network element can expose some functions of the network to applications in a controlled manner. In a 5G communication system, the network capability exposure network element may be a network capability exposure function (NEF). In a future communication system (such as a 6G communication system), the network capability exposure network element may still be an NEF network element. Alternatively, it may have other names, which are not limited in this application.

The application function network element can provide service data of various applications to the control plane network element of the operator's communication network, or obtain network data information and control information from the control plane network element of the communication network. In the 5G communication system, the application function network element may be an application function (AF), and in the future communication system (such as a 6G communication system), the application function network element may still be an AF network element, or may have other The name is not limited in this application.

The data network is mainly used to provide data transmission services for terminal equipment. The data network can be a private network, such as a local area network, or a public data network (PDN) network, such as the Internet (Internet), or a private network jointly deployed by operators, such as a configured IP multimedia network sub-network. System (IP multimedia corenetwork subsystem, IMS) service.

The charging function network element is mainly used for convergent charging, that is, the offline charging function and the online charging function are combined together. In a 5G communication system, the charging function network element may be a charging function (charging function, CHF). In a future communication system (such as a 6G communication system), the charging function network element may still be a CHF network element, or it may also be a CHF network element. It can have other names, which is not limited in this application.

In addition to the above network elements, the network architecture may also include a network slice admission control function (NSACF) logical entity, which is mainly responsible for controlling the number of sessions established in the network slice and registering with the terminals in the slice. The number of uplink and downlink data traffic transmitted within the slice does not exceed the maximum upper limit specified by the service level agreement (SLA) technical indicators of the network slice. It should be understood that the NSACF logical entity may be an independent NSACF network element, or may be a functional component included in the network element, and the network element may be a policy control network element, a charging function network element, or an access management network element , or a session management network element, or a slice selection function network element, or other above-mentioned network elements, which are not limited in this application. It should be understood that when the NSACF logical entity is a functional component included in a network element, the information interaction between the NSACF logical entity and the network element may be an interaction within the network element. In future communication systems (such as 6G communication systems), the network slice admission control function logic entity may still be an NSACF logic entity, an NSACF entity, or an NSACF network element, or may have other names. This application does not limited.

It should be understood that the above network elements or functions may be network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (eg, a cloud platform). Optionally, the foregoing network element or function may be implemented by one device, or may be implemented jointly by multiple devices, or may be a functional module in one device, which is not specifically limited in this embodiment of the present application.

For the convenience of description, in the following application, the access management network element is the AMF network element, the session management network element is the SMF network element, the user plane network element is the PDU session anchor or the UPF network element, and the policy control network element is the PCF network element. , the charging function network element is the CHF network element, and the network slice admission control function logical entity is the NSACF entity, which is described as an example. Further, the AMF network element is abbreviated as AMF, the SMF network element is SMF, the UPF network element is UPF, the PCF network element is PCF, the CHF network element is CHF, and the NSACF entity is NSACF. That is, the AMF described later in this application can be replaced by the access management network element, the SMF can be replaced by the session management network element, the PDU session anchor or the UPF network element can be replaced by the user plane network element, and the PCF can be replaced by the policy control network element. Element, CHF can be replaced by charging function network element, NSACF can be replaced by network slice admission control function logical entity.

Based on the above communication system, the present application provides a method, apparatus and system for session control. In order to facilitate the understanding of the technical solutions proposed in this application, the following takes a 5G communication system as an example to introduce related technologies involved in this application, which are also a part of the invention content of this application.

In recent years, communication business needs and application scenarios have gradually diversified. From the connection between people to the connection between all things, the types and number of users have increased, and the number of connections has increased exponentially. The communication network will become more and more congested, and more and more more complicated. If the network is compared to traffic, the vehicle is the user. With the increase of vehicles, the urban traffic will become congested. At this time, it is necessary to carry out "traffic management", that is, to implement the diversion management of the network.

A network slice is a logical structure with specific network characteristics, and is a key technology to meet the network differentiation requirements of the 5G mobile communication system proposed by the 3rd Generation Partnership Project (3GPP). In essence, network slicing is to divide the operator's physical network into multiple virtual networks. Different virtual networks correspond to different service requirements. In order to meet the different business needs of customers through network slicing, it can flexibly respond to different network application scenarios. Specifically, 5G networks will deal with three types of scenarios: 1) Enhanced mobile broadband (eMBB), mainly for applications such as 4K/8K ultra-high-definition time-frequency, holographic technology, augmented reality or virtual reality, etc. High requirements; 2) Massive machine type of communication (mMTC), in this scenario, massive IoT sensors do not belong to the fields of measurement, construction, agriculture, logistics, smart cities, homes, etc. These sensor devices are Very dense, large-scale, and most of them are stationary, with low requirements for latency and mobility; 3) Ultra reliable low latency communication (URLLC), mainly used in unmanned driving and Internet of Vehicles , automatic factories, telemedicine and other fields, requiring ultra-low latency and high reliability.

In other words, a 5G physical IoT network can be abstractly divided into multiple network slices. Each network slice constitutes an end-to-end logical network, which is logically isolated from each other and does not affect each other. Therefore, a network slicing is a logical network with specific network characteristics divided in an operator's communication network. The services of each network slice are identified by a single network slice selection assistance information (single-network slice selection assistance information, S-NSSAI), that is, the identification of the network slice is S-NSSAI.

When a terminal device obtains a service through a communication system, the terminal device first needs to sign a contract, and only after the contract is successful can it obtain a business service and perform communication. And after the signing is successful, the communication system will store the signing information of the terminal equipment, the signing information includes the identity of the terminal equipment, the network slice information signed by the terminal equipment, and the data network (DN) that provides services for the terminal equipment. information, etc. The identity identifier of the terminal device may be a subscription permanent identifier (SUPI), or an internet protocol (IP) address of the terminal device, or a media access control (media access control, MAC) address of the terminal device , or Ethernet Address; terminal equipment can sign up to one or more network slices, that is, terminal equipment can obtain different types of business services through different network slices signed up; the data network information that provides services for terminal equipment includes Data network name (DNN).

When the terminal device communicates and establishes a session, it will send a session establishment request message to the access and mobility management function network element AMF through the access network AN or RAN. The session establishment request message includes the attribute information of the session requested to be established. The attribute information of the session includes identification information of the terminal device, network slice identification information, data network information, and the like. The network slice identification information is used to indicate in which network slice the current session is established. Then, the AMF will select the session management function network element SMF according to the network slice identification information and the data network information, and the AMF will forward the session establishment request message to the selected SMF. Next, the SMF processes the session establishment request message after receiving the message. The SMF will determine whether to allow the establishment of the session according to the information stored by itself or by inquiring to other network elements. After confirming that the establishment of the session is allowed, the SMF will Select an appropriate user plane function network element UPF, and control the UPF to establish a packet data unit session (packet date unit session, PDU Session or PDU session) within the indicated network slice. Finally, the service information of the terminal equipment can be transmitted to the data network DN through the AN or RAN and the UPF.

It should be understood that in a 5G physical IoT network, multiple terminal devices may belong to the same customer who subscribes to communication service services, for example, the customer is an enterprise user. The operator will create one or more network slices for the customer according to the customer's order. At this time, the operator and the customer will determine the service level agreement (SLA) technical indicators of each network slice according to the actual business requirements. The SLA determines the size of the network slice ordered by the customer. However, the types and quantities of network slice scales ordered by different customers are different. Generally, the type of network slice scale, or the parameter of the network slice scale, is the maximum number of sessions allowed to be established in the network slice, that is, the maximum number of sessions in the network slice. number of sessions.

The maximum number of sessions of a network slice refers to the maximum allowable number of PDU sessions that can be established by a client accessing the current network slice. In the process of the customer's terminal device communicating through the current network slice, the operator needs to perform admission control on the PDU session requested by the customer's terminal device according to the maximum allowable number of PDU sessions corresponding to the customer: if the current network slice has established When the number of PDU sessions has reached or exceeded the maximum allowable number of PDU sessions, the requested PDU session will be rejected. In this way, the customer's usage of network slices is guaranteed not to exceed the upper limit determined by the SLA.

In order to limit the number of PDU sessions established in the network slice, in the 5G communication system, it is possible to check whether the number of PDU sessions established in the network slice exceeds a certain quota through the relevant network elements in the communication system. For example, one network element unified Or centrally check whether the number of PDU sessions established in the network slice exceeds the maximum number of sessions in the network slice. For another example, multiple network elements are allocated session quotas for multiple network slices, and then the multiple network elements are allocated according to their respective The session quota of the network slice checks whether the number of established PDU sessions in the network slice exceeds the session quota of the network slice. For example, the network slice admission control function logic entity NSACF checks whether the number of PDU sessions in the network slice exceeds the maximum number of sessions of the network slice. There are two ways for the NSACF to limit the number of PDU sessions in a network slice: 1) When requesting to establish a PDU session, the SMF asks the NSACF whether the maximum allowed number of PDU sessions has been reached, and if so, the NSACF will reject the requested PDU session. , otherwise the NSACF allows the PDU session requested to be established; 2) The NSACF subscribes to the SMF for the number of PDU sessions in the network slice. Each SMF in the same network slice will notify the NSACF when creating or releasing a PDU session, and the NSACF will report each SMF to the SMF. The total number of PDU sessions in the network slice is accumulated to obtain the total number of PDU sessions in the current network slice, and then the NSACF determines whether the total number of PDU sessions reaches the maximum number of sessions in the network slice: if so, the NSACF will notify each SMF. Deny the new session, otherwise, the NSACF will not restrict. It should be understood that the above two methods can be used sequentially or independently to limit the number of PDU sessions. In addition, similarly, the NSACF can also be replaced by the PCF, that is, the PCF implements the limit of the number of sessions in the network slice. At this time, the PCF will receive the session quota of the network slice allocated by the NSACF, that is, the NSACF allocates the maximum number of sessions in the network slice to the PCF. All or part of the number of sessions.

In addition, in the 5G communication system, for the session and service continuity (SSC) problems caused by the movement of terminal equipment, 3GPP provides three types of session and service continuity modes (session and service continuity mode). ,SSC mode). When the terminal device establishes a PDU session, it will select the PDU session anchor, that is, the UPF for connection. For SSC mode 1, when the terminal device moves, the UPF to which the terminal device is connected remains unchanged, that is, the terminal device does not create new PDUs. The session, that is, the Internet Protocol address (IP address) of the terminal device remains unchanged; for SSC mode 2, when the terminal device moves, the terminal device first releases the original PDU session and disconnects the connection with the original UPF, and then Request to establish a new PDU session and connect to a new UPF, that is, the IP address of the terminal device changes; for SSC mode 3, when the terminal device moves, the terminal device will first establish a new PDU session and connect to the new UPF, and then release the The original PDU session is disconnected from the original UPF.

When the terminal device moves, for the PDU sessions of SSC mode 2 and SSC mode 3, the terminal device will establish a new PDU session. However, due to the limitation of the number of sessions established in the network slice, it will fail to connect to the two modes. Issues with new UPFs and establishing new PDU sessions, resulting in session and business continuity failures. For example, for the original PDU session of SSC mode 2, the quota of the original PDU session released by the terminal device may be immediately occupied by the new PDU session of other terminal devices, so that when the number of sessions in the current network slice reaches the maximum allowable number of PDU sessions , which will cause the current terminal device to fail to establish a new PDU session and connect to a new UPF, that is, the failure to change the anchor point of the PDU session, that is, the failure to change the UPF. For another example, for the original PDU session of SSC mode 3, when the terminal device establishes a new PDU session and connects to a new UPF, if the number of sessions in the current network slice has reached the maximum allowable number of PDU sessions, the terminal device will also Unable to establish new PDU session and connect to new UPF.

Therefore, in order to avoid the problem of session and service continuity failure of the terminal device due to the limitation of the number of sessions in the network slice, it is ensured that the terminal device can also establish the PDU session normally after changing the connection PDU session anchor point after moving the location. , to communicate, the present application proposes a method for session control.

FIG. 2 shows a schematic flowchart of a method 200 for session control provided by the present application. The method 200 includes:

S201, the first network element receives, from the third network element or the terminal device, the session attribute information of the first session requested by the terminal device to establish, and correspondingly, the third network element or the terminal device sends the first network element the first network element requested to be established by the terminal device. Session attribute information for a session.

Specifically, in this embodiment of the present application, the first network element may receive the session attribute information of the first session requested by the terminal device to be established and sent by the third network element or the terminal device. Wherein, optionally, the first network element may be an NSACF entity, a policy control network element, a charging function network element, or an access and mobility management network element; the third network element may be a session The management network element may also be an access and mobility management network element, which is not limited in this application.

S202, the first network element determines to allow establishment of the first session according to the session attribute information of the second session of the terminal device and the session attribute information of the first session previously established.

In the above steps S201-S202, the first session is a new session corresponding to the second session, and the session attribute information of the first session and the session attribute information of the second session include the same terminal device identification information, network slice identification information, and data network information. That is, the first session and the second session are established in the network slice corresponding to the same network slice identifier.

Optionally, the session attribute information of the first session and the session attribute information of the second session further include the same session and service continuity mode SSC mode parameters, or may also be referred to as session and service continuity mode SSC mode information.

It should be understood that in this embodiment of the present application, the first session is a new session in which the second session needs to change the PDU session anchor due to the session and service continuity of the terminal device, and the first session or the second session is SSC mode 2 or SSC mode. 3 sessions. In other words, for the session of SSC mode 2 or the session of SSC mode 3 previously established by the terminal device, that is, the second session, after the location of the terminal device moves, in order to ensure the session and service continuity, it may be necessary to change the PDU of the second session. The session anchor point, that is, establishing a first session different from the PDU anchor point of the second session, and releasing the second session. During this process, the SMF controlling the first session may also change, which is different from the SMF controlling the second session.

It should also be understood that, in this embodiment of the present application, since the session attribute information of the PDU session includes multiple parameters or multiple types of information, the first session is a new session established by the terminal device after changing the PDU session anchor of the second session. session, and the first session and the second session are sessions in the same network slice, therefore, in the session attribute information of the first session and the session attribute information of the second session, the identification information of the terminal device, the network slice identification information and the Parameters such as data network information are the same. Optionally, the identification information of the terminal device is the subscription permanent identification SUPI, the network slice identification information is S-NSSAI, the data network information is the data network name DNN, and the specific name of the relevant information is not limited in this application.

It should be understood that the session attribute information of the second session is received by the first network element from other network elements and stored and recorded, or obtained by the first network element from context information stored or recorded by itself. The present application does not limit the acquisition method of the session attribute information of the second session.

For the case where the session attribute information of the second session is received and recorded by the first network element from other network elements, in a possible implementation manner, the first network element may obtain data from other network elements when the second session or the first session is established. The network element receives and saves the session attribute information of the second session. For example, the first network element is an NSACF entity, and the NSACF entity receives a request message for checking the number of sessions in the network slice received from the session management network element, or in a request message for updating the number of sessions in the network slice, or reserves the number of sessions in the network slice. In the session quota request message, the session attribute information of the second session is obtained. For another example, the first network element is a PCF, and the PCF obtains an update request message associated with a session management policy of the second session, or a message requesting establishment of a session management policy association of the second session, or notifies the control The session attribute information of the second session is obtained in the update message associated with the session management policy of the second session, or in the message requesting to delete the session management policy association of the second session. For a specific method for the first network element to receive and save the session attribute information of the second session from other network elements when the first session is established, reference may be made to the method 300 shown in FIG. 3 below.

For the case where the session attribute information of the second session is obtained by the first network element from context information saved or recorded by itself, a possible implementation manner is that the first network element is an access and mobility management network element, and the connection The ingress and mobility management network element may acquire the session attribute information of the second session from the context information stored or recorded by itself. Further optionally, the access and mobility management network element may receive a session establishment request message from the terminal device, where the session establishment request message includes session attribute information of the first session, and the session establishment request message requests establishment of the first session.

For the above step S202, the first network element determines to allow the establishment of the first session according to the session attribute information of the second session and the session attribute information of the first session. In a possible implementation manner, since the first session and the second session are sessions in the same network slice, the first network element determines to skip the first session according to the session attribute information of the second session and the first session. The number of sessions in the network slice corresponding to the second session is checked, and it is determined that the establishment of the first session is allowed. It should be understood that, after receiving the session attribute information of the first session, the first network element compares the session attribute information of the first session with the session attribute information of the second session, and determines the terminal in the session attribute information of the first session. When the device identification information, network slice identification information, and data network information are the same as the second session, the first network element will skip the check of the number of sessions in the corresponding network slice, and determine that the establishment of the first session is allowed.

Therefore, through the above method, after receiving the session attribute information of the first session requested by the terminal device to establish, the first network element can determine that the first session is the cause corresponding to the second session according to the saved session attribute information of the second session. A new session is requested to be established by changing the PDU session anchor. At this time, the first network element can allow the establishment of the first session, thereby avoiding that when the number of sessions in the current network slice has reached or exceeded the session quota in the network slice, the first network element If the session cannot be established, the terminal device can successfully modify the PDU session anchor, and the continuity of the session and service of the terminal device can be ensured.

In a possible implementation manner, the session attribute information of the second session will be used to indicate any one of the following: 1) the first network element does not restrict the establishment of the first session; 2) the first network element preempts the first session. 3) The establishment of the first session occupies the session quota of the second session. Optionally, the first network element may perform three corresponding operations according to the session attribute information of the second session, that is, the first network element skips checking the number of sessions in the corresponding network slice, and may only record the session attribute information of the second session. , or the first network element may also record the indication information of the three operations according to the session attribute information of the second session, that is, the first network element records the session attribute information of the second session and the indication information of the three operations, or further There can be other specific implementations. The present application does not limit the specific implementation.

Optionally, the first network element may further determine a validity timer for the session attribute information of the second session, where the validity timer indicates the validity time of the session attribute information of the second session. That is, after the valid timer expires, the first network element will delete the session attribute information of the second session. Alternatively, the first network element may also delete the session attribute information of the second session when it is determined that the establishment of the first session is allowed, regardless of whether the valid timer expires.

Therefore, by determining a valid timer for the session attribute information of the second session in the first network element, after the valid timer expires, the session attribute information of the second session is deleted, thereby preventing other subsequent sessions from being mistakenly It is determined to be the first session.

It should be understood that the first network element in the above method may be a network slice admission control function NSACF entity, or may be a policy control network element, or may also be an access and mobility management network element, which is not limited in this application.

Optionally, before the above step S201, the method 200 further includes the method 300 shown in FIG. 3, that is, when the first session is established, the first network element receives and saves the session attribute information for recording the second session from the second network element. specific method.

It should be noted that some of the steps mentioned below are the same as the above-mentioned method 200 , and the relevant details will not be repeated here. For the specific process, reference may be made to the relevant steps of the method 200 .

FIG. 3 shows a schematic flowchart of a method 300 for session control provided by the present application. The method 300 includes:

S301: The second network element sends first indication information to the terminal device, where the first indication information is used to instruct the establishment of a first session of the terminal device, or the first indication information is used to instruct the release and release of the second session of the terminal device and When the first session is established, correspondingly, the terminal device receives the first indication information from the second network element.

Specifically, in this embodiment of the present application, the second network element may be a session management network element corresponding to the second session of the terminal device.

It should be understood that, in this embodiment of the present application, two different indication contents of the first indication information correspond to two scenarios respectively: 1) establishment of the first session; 2) release of the second session and establishment of the first session.

In a possible implementation manner, when the first indication information is used to indicate the establishment of the first session of the terminal device, that is, the above scenario 1), corresponding to the situation that the second session is a session of SSC mode 3, the first session will be established first. The first session, and then the second session is released. At this time, optionally, the first indication information may also include a second session address validity time parameter, and the second session address validity time parameter indicates the valid duration of the second session, that is, The remaining valid time until the second session is released.

In another possible implementation manner, when the first indication information is used to indicate the release of the second session of the terminal device and the establishment of the first session, that is, the above scenario 2), the session corresponding to the second session is SSC mode 2 In the case of instructing to release the second session, the establishment of the first session will be instructed, for example, the first indication information is the release reason indication information of the second session.

It should be understood that before the above-mentioned first indication information indicates the establishment of the first session or the release of the second session and the establishment of the first session, the second network element may determine that the second session needs to be released according to the location information of the terminal device, and establish the first session. session. That is, before the above steps S301-S302, the location of the terminal device is moved, and the moved location information is sent to the second network element. After receiving the moved location information, the second network element determines that the second session needs to be released, Establishing the first session requires changing the PDU session anchor of the second session.

Optionally, after the second network element receives the location information after the terminal device moves, the second network element may further determine the third network element. The third network element and the second network element are core network network elements of the same type, the second network element is a core network network element corresponding to the second session, and the third network element is a core network network element corresponding to the first session. For example, the second network element and the third network element are both session management network elements, such as SMF.

It should be noted that the third network element here is the third network element in the foregoing method 200 .

It should be understood that the second network element and the third network element may be the same or different. That is, the second session of the terminal device, or the original PDU session, corresponds to the second network element; the first session of the terminal device, or the new PDU session, corresponds to the third network element. When the terminal device is required to release the second session and establish the first session, the corresponding second network element may or may not be changed. Therefore, the second network element and the third network element may be the same or different.

S302: The second network element sends session attribute information of the second session to the first network element, where the session attribute information of the second session is used by the first network element to determine that the establishment of the first session is allowed. The second network element receives the session attribute information of the second session.

Specifically, in the embodiment of the present application, for the scenario 1) in the above S301: the establishment of the first session, that is, the second session is a session of SSC mode 3, the second network element may send the first session to the first session when the first session is established. A network element sends session attribute information of the second session. For scenario 2) in the above S301: the release of the second session and the establishment of the first session, that is, the second session is a session of SSC mode 2, the second network element may release the second session and establish the first session, Send session attribute information of the second session to the first network element.

In a possible implementation manner, the second network element may determine a valid timer for the session attribute information of the second session according to the valid time parameter of the second session address in S301, and the valid time indicated by the valid timer may be longer than or equal to the valid time period indicated by the valid time parameter of the second session address.

In the above steps S301-S302, the first session is a new session corresponding to the second session, and the session attribute information of the first session and the session attribute information of the second session include the same terminal device identification information, network slice identification information, and data network information. That is, the first session and the second session are established in the network slice corresponding to the same network slice identifier. For a more detailed description of the session attribute information of the first session and the session attribute information of the second session, reference may be made to the relevant detailed description of S202 in the method 200 .

It should be understood that, in the above method 300, the first network element may be a network slice admission control function NSACF entity, or may be a policy control network element.

Hereinafter, some steps in the above methods 200 and 300 will be described in detail by taking the first network element as an NSACF entity (FIG. 4) or a policy control network element (FIG. 5) as an example.

It should be noted that some of the steps mentioned below are the same as the above-mentioned methods 200 and 300, and the relevant details will not be repeated here.

FIG. 4 shows a schematic flowchart of a specific example 400 of a method for session control provided by the present application.

In the specific example 400: the first network element is the NSACF entity; the second network element is the first session management network element, that is, the session management network element corresponding to the second session; the third network element is the second session management network element, that is The session management network element corresponding to the first session. The method 400 includes:

S401: The first session management network element sends first indication information to the terminal device, where the first indication information is used to instruct the establishment of a first session of the terminal device, or the first indication information is used to indicate the establishment of a second session of the terminal device Release and establishment of the first session, correspondingly, the terminal device receives the first indication information from the first session management network element.

For the specific implementation of this step, reference may be made to the detailed description of S301 in the method 300 .

S402, the first session management network element sends a first message to the NSACF entity, where the first message includes session attribute information of the second session, and correspondingly, the NSACF entity receives the first message from the first session management network element.

It should be understood that, in this embodiment of the present application, the first message may be sent by the first session management network element when the second session is established, and in this case, steps S402-S403 may be performed before the foregoing step S401; or the first message may also be It is sent by the first session management network element when the first session is established. This application does not limit this.

Specifically, in this embodiment of the present application, the first message may be used to check the number of sessions in the network slice corresponding to the network slice identifier. For example, the first message is a check message for the number of sessions in the network slice, which carries the SSC of the second session. The indication of the mode parameter or the reserved quota; or, the first message may be used to update the number of sessions in the network slice corresponding to the network slice identifier. For example, the first message is an update message for the number of sessions in the network slice, which carries the SSC mode parameter or indication of reserved quota; alternatively, the first message can also be used to check and update the number of sessions in the network slice corresponding to the network slice identifier, for example, the first message is the number of sessions in the network slice check and update message, It carries the SSC mode parameter of the second session or the indication of reserved quota; alternatively, the first message can also be used to reserve the session quota in the network slice corresponding to the network slice identifier, for example, the first message is the session in the network slice Quota reservation message. This application does not limit the specific function and name of the first message. Since the first message includes the session attribute information of the second session, before the NSACF entity receives the session attribute information of the first session, the NSACF entity will receive the session attribute information of the second session from the first session management network element .

Optionally, the first message may include a valid timer, where the valid timer is used by the NSACF entity to determine the valid time for the session attribute information of the second session.

S403, the NSACF entity stores the session attribute information of the second session.

That is, after receiving the session attribute information of the second session, the NSACF entity will save the session attribute information of the second session.

Optionally, the NSACF entity may determine a valid timer for the session attribute information of the second session. For example, when the first message includes a valid timer, the NSACF entity may determine the valid time for the saved session attribute information of the second session according to the valid timer in the first message, that is, configure the session attribute information for the second session. the valid timer. For another example, when the first message does not include a valid timer, the NSACF entity may set a valid timer for the session attribute information of the second session by itself. This application does not limit this. For the specific implementation of the valid timer in this step, reference may be made to the detailed description in the foregoing step S202.

For more specific implementation of steps S402-S403, reference may be made to the detailed description of S302 in method 300.

S404, the second session management network element sends a second message to the NSACF entity, where the second message includes session attribute information of the first session, and the second message is used to ask whether to allow the establishment of the first session, or to ask whether to allow the establishment of the first session. The establishment of the first session occupies the session quota of the second session, and accordingly, the NSACF entity receives the second message from the second session management network element.

It should be understood that after the location of the terminal device moves and it is determined that the first session needs to be established, the terminal device will request to establish the first session, and send the relevant request message to the second session management network element, and then the second session management network element will The above step S404 is executed.

It should also be understood that the first session management network element and the second session management network element in the above S401-S404 respectively correspond to the second network element and the third network element in the above method 300, that is, the first session management network element is the first session management network element. The session management network element corresponding to the two sessions, the second session management network element is the session management network element corresponding to the first session, and the first session management network element and the second session management network element may be the same or different.

Optionally, the second message may be a message for checking the number of sessions in a network slice, or a message for updating the number of sessions in a network slice, or a message for checking and updating the number of sessions in a network slice. This application specifies the name of the second message. Not limited.

S405, the NSACF determines to allow the establishment of the first session according to the previously obtained session attribute information of the second session of the terminal device and the session attribute information of the first session.

Specifically, in this embodiment of the present application, the NSACF determines that session attribute information of the second session exists from the stored attribute information of each session, where the session attribute information of the second session includes the same terminal device identification information as the first session, and the network Slice identification information, data network information, and optionally the same SSC mode parameter, the NSACF determines that the first session is a new session corresponding to the second session, and allows the establishment of the first session.

For the specific implementation of this step, reference may be made to the detailed description of S202 in the method 200 .

FIG. 5 shows a schematic flowchart of a specific example 500 of a method for session control provided by the present application.

In the specific example 500: the first network element is the policy control network element; the second network element is the first session management network element, that is, the session management network element corresponding to the second session; the third network element is the second session management network element , that is, the session management network element corresponding to the first session. The method 500 includes:

S501, the policy control network element receives the session quota in the network slice allocated by the NSACF entity.

Specifically, in this embodiment of the present application, the NSACF entity may allocate a session quota within a network slice to a policy control network element. For example, the NSACF entity can allocate all or part of the maximum number of sessions of the network slice to the policy control network element, so that the policy control network element can control the number of sessions established in the network slice according to the allocated session quota of the network slice .

S502: The first session management network element sends first indication information to the terminal device, where the first indication information is used to instruct the establishment of the first session of the terminal device, or the first indication information is used to indicate the establishment of the second session of the terminal device Release and establishment of the first session, correspondingly, the terminal device receives the first indication information from the first session management network element.

For more specific implementation of this step, reference may be made to the detailed description of S301 in the method 300 .

S503, the first session management network element sends a third message to the policy control network element, where the third message includes session attribute information of the second session, and accordingly, the policy control network element receives the third message from the first session management network element information.

It should be understood that, in this embodiment of the present application, the third message may be sent by the first session management network element when the second session is established, and in this case, steps S503-S504 may be performed before the foregoing step S502; or the third message may also be It is sent by the first session management network element when the first session is established. This application does not limit this.

Specifically, in this embodiment of the present application, the third message may be used to report the update of the session management policy association of the second session when the second session is established. For example, the third message is a session management policy association update report message, It carries the SSC mode parameter of the second session or the indication of the reserved quota; or, the third message can be used to request the establishment of the session management policy association of the second session when the second session is established, for example, the third message is the session The management policy association control request message, which carries the SSC mode parameter of the second session or the indication of the reserved quota; or, the third message can also be used to notify the session controlling the second session when the second session is released or is about to be released. The update of the management policy association, for example, the third message is a session management policy association update control notification message, which carries the SSC mode parameter of the second session or the indication of the reserved quota; or, the third message can also be used to request deletion of the The session management policy association of the second session, for example, the third message is a delete session management policy association request message, which carries the SSC mode parameter of the second session or the indication of the reserved quota. Because the session attribute information of the second session is included in the third message, before the policy control network element receives the session attribute information of the first session, the policy control network element will receive the second session from the first session management network element session attribute information.

Optionally, the third message may include a valid timer, where the valid timer is used for the policy control network element to determine the valid time for the session attribute information of the second session.

S504, the policy control network element stores the session attribute information of the second session.

That is, after receiving the session attribute information of the second session, the policy control network element will save the session attribute information of the second session.

Optionally, the policy control network element may determine a valid timer for the session attribute information of the second session. For example, when the third message includes a valid timer, the policy control network element may determine the valid time for the saved session attribute information of the second session according to the valid timer in the third message, that is, the session attribute of the second session information to configure the valid timer. For another example, when the third message does not include a valid timer, the policy control network element may set a valid timer for the session attribute information of the second session by itself. This application does not limit this. This application does not limit this. For the specific implementation of the valid timer in this step, reference may be made to the detailed description in the foregoing step S202.

For more specific implementation of steps S503-S504, reference may be made to the detailed description of S302 in method 300.

S505, the second session management network element sends a fourth message to the policy control network element, where the fourth message includes session attribute information of the first session, and the fourth message is used to request the establishment of a session management policy association of the first session, and the corresponding , the policy control network element receives the fourth message from the second session management network element.

It should be understood that after the location of the terminal device moves and it is determined that the first session needs to be established, the terminal device will request to establish the first session, and send the relevant request message to the second session management network element, and then the second session management network element will The above step S505 is performed.

It should also be understood that the first session management network element and the second session management network element in the foregoing S501-S505 correspond to the second network element and the third network element in the foregoing method 300, respectively, that is, the first session management network element is the first session management network element. The session management network element corresponding to the two sessions, the second session management network element is the session management network element corresponding to the first session, and the first session management network element and the second session management network element may be the same or different.

Optionally, the fourth message is a request message for creating a session management policy association, and the specific name of the fourth message is not limited in this application.

S506: The policy control network element determines to allow establishment of the first session according to the previously obtained session attribute information of the second session of the terminal device and the session attribute information of the first session.

Specifically, in this embodiment of the present application, the policy control network element determines that there is session attribute information of the second session from saving each session attribute information, wherein the session attribute information of the second session includes the same information as the session attribute information of the second session. The same terminal equipment identification information, network slice identification information, data network information, and optionally the same SSCmode parameter as the first session, the policy control network element determines that the first session is a new session corresponding to the second session. session.

For the specific implementation of this step, reference may be made to the detailed description of S202 in the method 200 .

It should be understood that, in this application, the meanings of "save" and "record" are the same, and the two are interchangeable.

It should also be understood that in this application, the NSACF entity may be the NSACF, the first session management network element may be the first SMF, the second session management network element may be the second SMF, and the policy control network element may be the PCF. This is not limited.

FIG. 6 shows a schematic flowchart of another session control method 600 provided by the present application. The method 600 includes:

S601: The terminal device sends first information to a fourth network element, where the first information is used to request establishment of a first session of the terminal device, where the first information includes identification information of a second session of the terminal device, wherein the first session It is a new session in which the second session needs to change the PDU session anchor due to the session and service continuity of the terminal device. The first session and the second session are established in the same network slice. Correspondingly, the fourth network element receives from the terminal device first information.

It should be understood that the terminal device sends the first information to the fourth network element, the terminal device may directly send the first information to the fourth network element, or the terminal device may also send the first information to the fourth network element through other network elements. This is not limited.

Specifically, in this embodiment of the present application, the fourth network element is an access and mobility management network element, such as an AMF, and the access and mobility management network element receives a session establishment request message from a terminal device, where the session establishment request message contains It includes the first information, including the identifier of the first session (ie, the new session ID) and the identifier of the second session (old session ID); or, the fourth network element is a session management network element, for example, SMF, the session management network The element receives a create session context request message from the first access and mobility management network element, the first access and mobility management network element is the access and mobility management network element corresponding to the first session, and the create session context request message includes first information; or, the fourth network element is a policy control network element, such as a PCF, and the policy control network element receives a request message for creating a session management policy association from a third session management network element, where the third session management network element is the first information. A session management network element corresponding to a session, and the request message for creating a session management policy association includes the first information. This application does not limit the specific network element type of the fourth network element.

Optionally, for the case where the fourth network element is an access and mobility management network element or a policy control network element, the fourth network element may further determine from the context information saved by itself that the first session is a new one corresponding to the second session. In this case, the fourth network element may allow the establishment of the first session to occupy the session quota of the second session.

S602, the fourth network element determines to skip the check of the number of sessions in the network slice according to the identification information of the second session, and determines to allow establishment of the first session.

Specifically, in this embodiment of the present application, the fourth network element may determine, according to the identification information of the second session, that the first session is a new session established by the terminal device because the second session changes the PDU session anchor point. The four network elements can directly skip the step of checking the number of sessions within the network slice and allow the establishment of the first session.

Therefore, by receiving the request message of the first session and the identification information of the second session by the fourth network element, the fourth network element can determine that the first session is a new session corresponding to the second session after changing the PDU session anchor point. The fourth network element will not check whether the number of sessions in the network slice reaches or exceeds the session quota in the network slice, but directly allows the establishment of the first session, thereby avoiding that the number of sessions in the current network slice has reached or exceeded the network slice. When the session quota is used, if the first session cannot be established, the terminal device can successfully modify the PDU session anchor, and the continuity of the session and service of the terminal device can be ensured.

FIG. 7 and FIG. 8 are schematic structural diagrams of a possible disaster roaming device according to an embodiment of the present application. These apparatuses can implement the functions of the terminal device or any network element in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In this embodiment of the present application, the apparatus may be a terminal device, a first network element, a second network element, or a module applied to the terminal device, the first network element or the second network element ( such as chips).

FIG. 7 is a schematic structural diagram of an apparatus 1000 for session control provided by an embodiment of the present application. The apparatus 1000 may include a transceiver unit 1001 and a processing unit 1002 .

When the apparatus 1000 is configured to implement the function of the first network element in the method embodiment shown in FIG. 2 , the transceiver unit is configured to receive session attribute information of the first session requested by the terminal device to be established; the processing unit is configured to The established session attribute information of the second session of the terminal device and the session attribute information of the first session determine that the establishment of the first session is allowed; wherein, the first session corresponds to the second session The session attribute information of the first session and the session attribute information of the second session include the same identification information of the terminal device, network slice identification information, and data network information.

When the apparatus 1000 is used to implement the function of the second network element in the method embodiment shown in FIG. 3 , the transceiver unit is used to send first indication information to a terminal device, where the first indication information is used to instruct the terminal device establishment of the first session, or the first indication information is used to indicate the release of the second session of the terminal device and establishment of the first session; the transceiver unit is further configured to send the first network element to the first network element. Session attribute information of the second session, where the session attribute information of the second session is used by the first network element to determine that the establishment of the first session is permitted; wherein the first session corresponds to the second session The session attribute information of the first session and the session attribute information of the second session include the same identification information of the terminal device, network slice identification information, and data network information.

When the apparatus 1000 is configured to implement the function of the fourth network element in the method embodiment shown in FIG. 6 , the transceiver unit is configured to receive first information from a terminal device, where the first information is used to request the first information of the terminal device The establishment of a session, the first information includes the identification information of the second session of the terminal device, wherein the first session is the second session because the session of the terminal device and business continuity need to change the protocol The new session of the session anchor point of the data unit PDU, the first session and the second session are established in the same network slice; the processing unit is configured to determine, according to the identification information of the second session, to skip the The number of sessions in the network slice is checked, and it is determined that the establishment of the first session is allowed.

For a more detailed description of the foregoing transceiver unit 1001 and the processing unit 1002, reference may be made to the relevant descriptions in the foregoing method embodiments, which are not described herein again.

FIG. 8 shows a schematic block diagram of an apparatus 2000 to which an embodiment of the present application is applied. Any network element involved in any of the foregoing methods 200 to 600 may be implemented by the apparatus shown in FIG. 8 .

It should be understood that the apparatus 2000 may be a physical device, a component of the physical device (eg, an integrated circuit, a chip, etc.), or a functional module in the physical device.

As shown in FIG. 8 , the apparatus 2000 includes: one or more processors 2001 . The processor 2001 may store execution instructions for executing the methods of the embodiments of the present application. Optionally, the processor 2001 may call an interface to implement the receiving and sending functions. The interface may be a logical interface or a physical interface, which is not limited. For example, the interface may be a transceiver circuit, or an interface circuit. Transceiver circuits or interface circuits for realizing receiving and transmitting functions may be separate or integrated. The above-mentioned transceiver circuit or interface circuit can be used for code/data reading and writing, or the above-mentioned transceiver circuit or interface circuit can be used for signal transmission or transmission.

Alternatively, the interface can be implemented by a transceiver. Optionally, the apparatus 2000 may further include a transceiver 2003 . The transceiver 2003 may be referred to as a transceiver unit, a transceiver, a transceiver circuit or a transceiver, etc., for implementing a transceiver function.

Optionally, the apparatus 2000 may further include a memory 2002 . This embodiment of the present application does not specifically limit the specific deployment location of the memory 2002, and the memory may be integrated in the processor, or may be independent of the processor. In the case where the apparatus 2000 does not include a memory, it is only necessary that the apparatus 2000 has a processing function, and the memory may be deployed in other locations (eg, a cloud system).

The processor 2001, the memory 2002 and the transceiver 2003 communicate with each other through an internal connection path to transmit control and/or data signals.

It will be appreciated that, although not shown, the device 2000 may also include other devices, such as input devices, output devices, batteries, and the like.

Optionally, in some embodiments, the memory 2002 may store execution instructions for executing the methods of the embodiments of the present application. The processor 2001 can execute the instructions stored in the memory 2002 in combination with other hardware (such as the transceiver 2003) to complete the steps of the method shown below. For the specific working process and beneficial effects, refer to the descriptions in the method embodiments below.

The methods disclosed in the embodiments of the present application may be applied to the processor 2001 or implemented by the processor 2001 . The processor 2001 may be an integrated circuit chip with signal processing capability. In the implementation process, each step of the method can be completed by an integrated logic circuit of hardware in a processor or instructions in the form of software. The aforementioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable Logic devices, discrete gate or transistor logic devices, discrete hardware components. The methods, steps, and logic block diagrams disclosed in the embodiments of this application can be implemented or executed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in conjunction with the embodiments of the present application may be directly embodied as executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. Software modules can be located in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory or electrically erasable programmable memory, registers, etc. in the storage medium. The storage medium is located in the memory, and the processor reads the instructions in the memory, and completes the steps of the above method in combination with its hardware.

It will be appreciated that memory 2002 may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Wherein, the non-volatile memory may be a read-only memory ROM, a programmable read-only memory (programmable ROM, PROM), an erasable programmable read-only memory (erasable PROM, EPROM), an electrically erasable programmable read-only memory (electrically EPROM, EEPROM) or flash memory. Volatile memory may be random access memory RAM, which acts as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synchlink DRAM, SLDRAM) And direct memory bus random access memory (direct rambus RAM, DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but not be limited to, these and any other suitable types of memory.

In addition, in this application, the apparatus 1000 is presented in the form of functional modules. A "module" herein may refer to an application-specific integrated circuit ASIC, a circuit, a processor and memory executing one or more software or firmware programs, an integrated logic circuit, and/or other devices that may provide the above-described functions. In a simple embodiment, those skilled in the art can contemplate that the apparatus 1000 may take the form shown in FIG. 7 . The processing unit 1001 may be implemented by the processor 2001 shown in FIG. 8 . Optionally, if the computer device shown in FIG. 8 includes the memory 2002 , the processing unit 1002 may be implemented by the processor 2001 and the memory 2002 . The transceiver unit 1001 can be implemented by the transceiver 2003 shown in FIG. 8 . The transceiver 2003 includes a receive function and a transmit function. Specifically, the processor is realized by executing the computer program stored in the memory. Optionally, when the apparatus 1000 is a chip, the function and/or implementation process of the transceiver unit 1001 may also be implemented by pins or circuits. Optionally, the memory may be a storage unit in the chip, such as a register, a cache, etc., and the storage unit may also be a storage unit located outside the chip in the computer device, as shown in FIG. 8 . The memory 2002, alternatively, may also be a storage unit deployed in other systems or devices, not within the computer device. Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

Various aspects or features of the present application may be implemented as methods, apparatus, or articles of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used in this application encompasses a computer program accessible from any computer readable device, carrier or medium. For example, computer readable media may include, but are not limited to: magnetic storage devices (eg, hard disks, floppy disks, or magnetic tapes, etc.), optical disks (eg, compact discs (CDs), digital versatile discs (DVDs) etc.), smart cards and flash memory devices (eg, erasable programmable read-only memory (EPROM), cards, stick or key drives, etc.). Additionally, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and/or carrying instructions and/or data.

The present application also provides a computer-readable medium on which a computer program is stored, and when the computer program is executed by a computer, implements the functions of any of the foregoing method embodiments.

The present application also provides a computer program product, which implements the functions of any of the foregoing method embodiments when the computer program product is executed by a computer. In the above-mentioned embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented in software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general purpose computer, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be downloaded from a website site, computer, server or data center Transmission to another website site, computer, server, or data center by wire (eg, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (eg, infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that includes an integration of one or more available media. The available media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, high-density digital video discs (DVDs)), or semiconductor media (eg, solid state disks, SSD)) etc.

It is to be understood that reference throughout the specification to an "embodiment" means that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present application. Thus, various embodiments throughout this specification are not necessarily necessarily referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its functions and internal logic, and should not be dealt with in the embodiments of the present application. implementation constitutes any limitation.

It should also be understood that in this application, "when", "if" and "if" all mean that the UE or the base station will make corresponding processing under certain objective circumstances, not a limited time, and does not require the UE Or the base station must have a judgment action when it is implemented, and it does not mean that there are other limitations.

Additionally, the terms "system" and "network" are often used interchangeably herein. The term "and/or" in this article is only an association relationship to describe the associated objects, indicating that there can be three kinds of relationships, for example, A and/or B, it can mean that A exists alone, A and B exist at the same time, and A and B exist independently B these three cases.

The terms "at least one of" or "at least one of" herein mean all or any combination of the listed items, eg, "at least one of A, B, and C", It can be expressed that there are six cases of A alone, B alone, C alone, A and B at the same time, B and C at the same time, and A, B and C at the same time.

In this application, unless otherwise specified, "at least one" refers to one or more, and "a plurality" refers to two or more.

It should be understood that, in various embodiments of the present application, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean that B is only determined according to A, and B may also be determined according to A and/or other information.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above may refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

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

The functions, if implemented in the form of software functional units and sold or used as independent products, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution, and the computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program codes .

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. should be covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims (30)

1. A method for session control, comprising: The first network element receives session attribute information of the first session requested by the terminal device to be established; determining, by the first network element, that the establishment of the first session is permitted according to the session attribute information of the previously established second session of the terminal device and the session attribute information of the first session; Wherein, the first session is a new session corresponding to the second session, and the session attribute information of the first session and the session attribute information of the second session include the same identification information of the terminal device, Network slice identification information, and data network information. 2 . The method according to claim 1 , wherein the session attribute information of the first session and the session attribute information of the second session further include the same session and service continuity mode SSC mode parameters. 3 . 3. The method according to claim 1 or 2, wherein the first session is a new one in which the session anchor of a protocol data unit (PDU) needs to be changed for the second session due to the session and business continuity of the terminal device. session, the first session and the second session are SSC mode 2 sessions or SSC mode 3 sessions; The first network element determining to allow the establishment of the first session includes: The first network element determines to skip the check of the number of sessions in the network slice corresponding to the network slice identifier, and determines to allow establishment of the first session. 4. The method according to claims 1-3, wherein the session attribute information of the second session is used to indicate: not restricting the establishment of the first session; or, reserve a quota for the first session; or, The establishment of the first session occupies the session quota of the second session. 5. The method according to any one of claims 1-4, wherein the method further comprises: The first network element determines a validity timer for the session attribute information of the second session, and the validity timer indicates the validity time of the session attribute information of the second session. 6. The method according to any one of claims 1-5, wherein the first network element is a network slice admission control function NSACF entity, and the first network element receives a first request for establishment by a terminal device at the first network element. Before the session attribute information of the session, the method further includes: The NSACF entity receives a first message from a first session management network element, where the first session management network element is a session management network element corresponding to the second session, and the first message includes the session attribute information of the second session; The NSACF entity stores session attribute information of the second session. 7. The method according to claim 6, wherein the first message is used for: Check the number of sessions in the network slice corresponding to the network slice identifier, or update the number of sessions in the network slice corresponding to the network slice identifier, or reserve the session quota in the network slice corresponding to the network slice identifier. 8. The method according to claim 6 or 7, wherein the first network element receives session attribute information of the first session requested by the terminal device to establish, comprising: The NSACF entity receives a second message from a second session management network element, where the second session management network element is a network element corresponding to the first session, and the second message includes the first session attribute information of the session, the second message is used to ask whether to allow the establishment of the first session, or to update the number of sessions in the network slice corresponding to the network slice identifier, or to ask whether to allow the The establishment of the first session occupies the session quota of the second session. 9. The method according to any one of claims 1-5, wherein the first network element is an access and mobility management network element, and the first network element receives a first request to establish a terminal device at the first network element. Before the session attribute information of the session, the method further includes: The access and mobility management network element acquires session attribute information of the second session. 10 . The method according to claim 9 , wherein the receiving, by the first network element, session attribute information of the first session requested by the terminal device to establish, comprises: 10 . The access and mobility management network element receives a session establishment request message from the terminal device, the session establishment request message includes session attribute information of the first session, and the session establishment request message requests establishment of the first session . 11. A method for session control, comprising: The second network element sends first indication information to the terminal device, where the first indication information is used to instruct the establishment of the first session of the terminal device, or the first indication information is used to instruct the first indication information of the terminal device The release of the second session and the establishment of the first session; sending, by the second network element, session attribute information of the second session to the first network element, where the session attribute information of the second session is used by the first network element to determine that establishment of the first session is permitted; Wherein, the first session is a new session corresponding to the second session, and the session attribute information of the first session and the session attribute information of the second session include the same identification information of the terminal device, Network slice identification information, and data network information. 12 . The method according to claim 11 , wherein the session attribute information of the first session and the session attribute information of the second session further comprise the same session and service continuity mode SSC mode parameters. 13 . 13. The method according to claim 11 or 12, wherein the first session is a new one in which the session anchor of a protocol data unit (PDU) needs to be changed for the second session due to the session and service continuity of the terminal device. session, the first session and the second session are SSC mode 2 sessions or SSC mode 3 sessions; The session attribute information of the second session is used by the first network element to determine that the establishment of the first session is allowed, including: The session attribute information of the second session is used by the first network element to determine to skip the check of the number of sessions in the network slice corresponding to the network slice identifier, and to determine that establishment of the first session is allowed. The method according to any one of claims 11-13, wherein the first network element is a network slice admission control function NSACF entity, the second network element is a first session management network element, and the The second network element sends the session attribute information of the second session to the first network element, including: The first session management network element sends a first message to the NSACF entity, where the first session management network element is a session management network element corresponding to the second session, and the first message includes the second session session attribute information. 15. The method of claim 14, wherein the first message is used to: Check the number of sessions in the network slice corresponding to the network slice identifier, or update the number of sessions in the network slice corresponding to the network slice identifier, or reserve a quota for sessions in the network slice corresponding to the network slice identifier . 16. The method according to any one of claims 11-13, wherein the first network element is a policy control network element, the second network element is a first session management network element, and the second network element is a The network element sends the session attribute information of the second session to the first network element, including: The first session management network element sends a third message to the policy control network element, the first session management network element is a session management network element corresponding to the second session, and the third message includes the first session management network element. Session attribute information of the second session. 17. The method of claim 16, wherein the third message is used to: Report the update of the session management policy association of the second session, or request the establishment of the session management policy association of the second session, or notify the update of the session management policy association that controls the second session, or request deletion A session management policy association for the second session. 18. An apparatus for session control, characterized in that it is used to execute the method according to any one of claims 1-10; or, For carrying out the method of any one of claims 11-17. 19. A system for session control, wherein the system comprises a first network element, a terminal device; The first network element is configured to receive session attribute information of the first session requested by the terminal device to be established; The first network element is further configured to determine that the establishment of the first session is permitted according to the session attribute information of the second session of the terminal device and the session attribute information of the first session previously established; Wherein, the first session is a new session corresponding to the second session, and the session attribute information of the first session and the session attribute information of the second session include the same identification information of the terminal device, Network slice identification information, and data network information. 20. The system according to claim 19, wherein the session attribute information of the first session and the session attribute information of the second session further comprise the same session and service continuity mode SSC mode parameters. 21. The system according to claim 19 or 20, wherein the first session is a new one in which the session anchor of a protocol data unit (PDU) is changed for the second session due to the session and service continuity of the terminal device. session, the first session and the second session are SSC mode 2 sessions or SSC mode 3 sessions; The first network element is used to determine that the establishment of the first session is allowed, and the first network element is specifically used for: It is determined to skip the check of the number of sessions in the network slice corresponding to the network slice identifier, and it is determined that establishment of the first session is allowed. 22. The system according to any one of claims 19-21, wherein the session attribute information of the second session is used to indicate: not restricting the establishment of the first session; or, reserve a quota for the first session; or, The establishment of the first session occupies the session quota of the second session. 23. The system according to any one of claims 19-22, wherein the first network element is further configured to determine a valid timer for the session attribute information of the second session, and the valid timer indicates The valid time of the session attribute information of the second session. 24. The system according to any one of claims 19-23, wherein the first network element is a network slice admission control function NSACF entity, the system further comprises a first session management network element, the first network element A session management network element is the session management network element corresponding to the second session. Before the first network element is used to receive the session attribute information of the first session requested by the terminal device to be established, the first network element Also used for: receiving a first message from the first session management network element, the first message including session attribute information of the second session of the terminal device; The session attribute information of the second session is saved. 25. The system of claim 24, wherein the first message is used to: Check the number of sessions in the network slice corresponding to the network slice identifier, or update the number of sessions in the network slice corresponding to the network slice identifier, or reserve the session quota in the network slice corresponding to the network slice identifier. 26. The system according to claim 24 or 25, wherein the system further comprises a second session management network element, the second session management network element is a network element corresponding to the first session, the The first network element is configured to receive session attribute information of the first session requested by the terminal device to establish, and the first network element is specifically configured to: A second message is received from the second session management network element, the second message includes session attribute information of the first session of the terminal device, and the second message is used to inquire whether to allow the first session The establishment of the first session is either used to update the number of sessions in the network slice corresponding to the network slice identifier, or used to inquire whether the establishment of the first session is allowed to occupy the session quota of the second session. 27. The system according to any one of claims 19-23, wherein the first network element is an access and mobility management network element, and the first network element is used to receive the terminal device request Before the session attribute information of the established first session, the access and mobility management network element is further used for: Acquire session attribute information of the second session. 28. The system according to claim 27, wherein the first network element is configured to receive session attribute information of the first session requested by the terminal device to establish, and the access and mobility management network element is specifically configured to use At: A session establishment request message is received from the terminal device, the session establishment request message includes session attribute information of the first session, and the session establishment request message requests establishment of the first session. 29. A computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1-10 is implemented; or, A method as claimed in any of claims 11-17 is implemented. 30. A chip, comprising: a processor for reading instructions stored in a memory, and when the processor executes the instructions, the chip implements any one of the preceding claims 1-17 method described in item.

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