CN108605269B

CN108605269B - Session management method and device

Info

Publication number: CN108605269B
Application number: CN201780009886.8A
Authority: CN
Inventors: 窦凤辉; 金辉; 欧阳国威; 杨皓睿; 何岳
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2017-01-09
Filing date: 2017-03-20
Publication date: 2021-05-18
Anticipated expiration: 2037-03-20
Also published as: CN113784418B; CN113784418A; CN108605269A; CN113784417A; WO2018126535A1

Abstract

A session management method and device, thereby realizing the conversion of PDU session from active state to idle state. The method comprises the following steps: a first device receives a request message for activating a PDU session; the first device sends a timer of the PDU session to a second device; the first device receives a first message initiated by the second device to invalidate the operation of the PDU session; the first message is issued by the second device detecting no data transmission on the PDU session and persisting until the timer times out. The operation of invalidating the PDU session may include: and converting the PDU session from an active state to an idle state or deleting the PDU session.

Description

Session management method and device

The present application claims priority of chinese patent application with application number PCT/CN2017/070684, entitled "a session management method and apparatus", filed in 2017, 1, 9, and incorporated herein by reference in its entirety.

Technical Field

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

Background

In a Long Term Evolution (LTE) system, session management is performed based on a UE, and all bearers connected to all Packet Data Units (PDUs) in a session are activated or deactivated at the same time. After the releasing procedure of S1 is executed, the state between the UE and the core network is changed from the Connected state (ECM _ Connected) to the IDLE state (ECM _ IDLE). After performing a Service request (Service request) procedure, all bearers are activated, so that the UE and the core network are switched from an idle state to a connected state (which may also be referred to as an active state).

In a fifth generation mobile communication technology (5G) system, Session management is performed based on a PDU Session flow (Session). When the UE triggers multiple PDU sessions, each PDU Session has an independent state (ACTIVE state _ ACTIVE or IDLE state _ IDLE). When uplink and downlink data transmission is carried out, a Service request message sent by the UE carries a PDU Session ID required by the data transmission, so that when the Service request message is activated, only the PDU Session corresponding to the PDU Session ID is activated, and the PDU Session corresponding to the PDU Session ID is converted from an idle state to an activated state.

However, in the prior art, only the PDU Session is converted from the idle state to the active state, and an implementation manner of converting the PDU Session from the active state to the idle state is not implemented.

Disclosure of Invention

The embodiment of the application provides a session management method and device, so that a PDU session is converted from an active state to an idle state.

In a first aspect, an embodiment of the present application provides a session management method, including:

a first device receives a request message for activating a Packet Data Unit (PDU) session; the first device sends a timer of the PDU session to a second device; the first device receives a first message initiated by the second device to invalidate the operation of the PDU session; the first message is issued by the second device detecting no data transmission on the PDU session and persisting until the timer times out. The operation of invalidating the PDU session may include: and converting the PDU session from an active state to an idle state or deleting the PDU session.

Wherein, the first message may carry an identifier of the PDU session.

The first device is a first core network device, and the second device is a second core network device, or a base station, or a terminal. The first core network device may be a control plane network element, such as SMF, on the core network side. The second core network device may be a user plane network element, such as a UPF, on the core network side.

It should be noted that the activation of the PDU session may be activation when the PDU session is established, or the PDU session is converted from an idle state to an active state, or the activation of the PDU session when cell handover is performed.

By the above scheme, when the PDU session is activated, the first device sends a timer to the second device, so that the second device sends out a message for invalidating the operation of the PDU session when detecting that no data is transmitted on the PDU session and continuing until the timer times out. Based on the method, the PDU conversation without data transmission is triggered to be deleted or converted into an idle state, so that resource waste caused by the fact that the PDU conversation without data transmission occupies resources is avoided.

In a possible design, before the first device sends the timer to the second device, the first device obtains the timer corresponding to the PDU session, which may be specifically obtained by one of the following manners:

the first implementation mode comprises the following steps:

the first device determines a timer for the PDU session based on slice information for a network slice to which the PDU session belongs.

The second implementation mode comprises the following steps:

and the first equipment receives the timer of the PDU session sent by the third core network equipment.

The third implementation mode comprises the following steps:

and the first equipment determines the timer of the PDU session based on the Name of a Data Network (DNN) or the Name of an Access Point (APN).

In one possible design, the method further includes:

and the first equipment sends indication information to the second equipment, wherein the indication information is used for indicating the operation of invalidating the PDU session.

The first device may send the indication information to the second device together with the timer, or may send the indication information separately, which is not specifically limited in this embodiment of the application.

In one possible design, the indication information may be transmitted by a third core network device. Specifically, after receiving the request message, the first device receives indication information sent by a third core network device, where the indication information is information used to indicate that the PDU session operation is invalid.

In one possible design, the first device may not send the indication information to the second device, so that after receiving the first message, the first device determines, based on the indication information, that the operation of invalidating the PDU session is to convert the PDU session from the active state to the idle state or to delete the PDU session.

In one possible design, the first message may carry an identifier of the PDU session.

Based on this, the first message may also carry a cause value, where the cause value is used to indicate that a timer of the PDU session expires.

In the above design, the cause value is carried in the first message, so that the first device can know, at the time of the first message, what reason the second device is to trigger the first message, and based on this, determine the operation to be performed next.

In one possible design, the operation of invalidating the PDU session is to transition the PDU session from an active state to an idle state, and the method further includes:

and after receiving the first message, the first device sends a message for indicating to delete the information related to the base station and corresponding to the PDU session to the second core network device. And executing the operation of deleting the information related to the base station corresponding to the PDU session after the second core network equipment receives the message for indicating the deletion of the information related to the base station corresponding to the PDU session.

and after receiving the first message, the first device sets the state of the PDU session to an idle state.

Through the design, the first equipment stores the state of the PDU session, so that the state synchronization with the PDU session on the terminal is executed subsequently.

In one possible design, the operation of invalidating the PDU session is deleting the PDU session, the method further comprising:

and after receiving the first message, the first device sends a message for indicating to delete the information related to the PDU session to the second core network device. Therefore, after the second core network device receives the message for indicating to delete the information related to the PDU session, all the information related to the PDU session stored by the second core network device is deleted.

and after receiving the first message, the first device sends a message for indicating the terminal to delete the information related to the PDU session to the terminal. Therefore, after the terminal receives the message for indicating the terminal to delete the information related to the PDU session, all the information related to the PDU session stored by the terminal is deleted.

In one possible design, after receiving the first message, the first device sends a message to the base station, where the message is used to instruct the base station to release the context of the PDU session. And deleting or suspending the radio resource corresponding to the PDU session after the base station receives the message for indicating the base station to release the context of the PDU session.

In one possible design, the method may further include:

and after receiving the first message, the first device sends a message for instructing the fourth core network device to set the state of the PDU session to an idle state to the fourth core network device. Therefore, after receiving the message for instructing the fourth core network device to set the state of the PDU session to an idle state, the fourth core network device sets the state of the PDU session stored in the fourth core network device to an idle state. And when the fourth core network equipment subsequently executes the operation related to the PDU session, executing the operation based on the state of the PDU session.

In a possible design, a first core network device receives a second message sent by a fourth core network device, where the second message carries an identifier of a PDU session of a user plane context to be updated;

and after receiving the second message, the first device updates the user plane context of the PDU session corresponding to the identification of the PDU session. Through the design, before cell switching is performed, after the first core network device receives the second message sent by the fourth core network device, the user plane context of the PDU session corresponding to the identification of the PDU session is updated.

In a second aspect, an embodiment of the present application further provides a session management method, including:

when a Packet Data Unit (PDU) session is activated, a base station receives a timer of the PDU session sent by first core network equipment; and the base station detects that no data is transmitted on the PDU session and continuously sends a first message for invalidating the operation of the PDU session to the first core network equipment when the timer is timed out.

Through the design, the first core network equipment issues the timer to the base station when the PDU session is activated, so that the base station monitors that no data is transmitted on the PDU session when monitoring the PDU session, and triggers and sends the first message to the first core network equipment when the timer is overtime, and the first core network equipment executes the operation of invalidating the PDU session after receiving the first message. Based on the method, the PDU session without data transmission is triggered to be invalid, so that resource waste caused by the fact that the PDU session without data transmission occupies resources is avoided.

Wherein the operation of invalidating the PDU session comprises: and converting the state of the PDU session from an active state to an idle state or deleting the PDU session.

In one possible design, the method may further include:

when the PDU session is activated, the base station receives indication information sent by the first core network equipment, wherein the indication information is used for indicating the operation of invalidating the PDU session.

Through the design, the base station is instructed by the first core network device to detect that no data is transmitted on the PDU session and the timer is expired, so as to trigger the operation required to be executed by the first core network device. Of course, the first core network device may not send the indication information to the base station, so that the first core network device determines the operation to be triggered after receiving the first message sent by the base station.

In one possible design, the first message may carry an identification of the PDU session.

In addition, the first message may further carry a cause value, where the cause value is used to indicate that a timer of the PDU session is expired.

In a possible design, after a base station sends a first message to a first core network device, the first core network device may trigger the base station to release the context of the PDU session, and specifically, the base station receives a message sent by the first core network device and used for instructing the base station to release the context of the PDU; and the base station deletes or suspends the wireless resources corresponding to the PDU session.

In a possible design, after receiving a message sent by the first core network device and used for instructing the base station to release the context of the PDU, the base station sets the saved state of the PDU session to an idle state.

Through the design, the base station saves the state of the PDU session, so that the operation aiming at the PDU session can be executed subsequently based on the state of the PDU session.

In one possible design, the method may further include:

and the base station deletes the mapping relation between the service quality QoS flow corresponding to the PDU conversation and the radio resource bearing DRB after monitoring that no data is transmitted on the PDU conversation and continuing to time out the timer.

Optionally, the base station may delete the mapping relationship between the quality of service QoS flow corresponding to the PDU session and the radio resource bearer DRB when receiving the first message sent by the first core network device. The mapping relationship between the quality of service (QoS) flow corresponding to the PDU session and the radio resource bearer (DRB) can be deleted before the first message is sent to the first core network device after no data transmission is monitored on the PDU session and the timer is overtime.

In one possible design, the method may further include:

and the base station sends a message for indicating the terminal to delete or suspend the wireless resource corresponding to the PDU session to the terminal after monitoring that no data is transmitted on the PDU session and continuing until the timer is overtime.

Optionally, the base station may send, to the terminal, a message for instructing the terminal to delete or suspend the radio resource corresponding to the PDU session after deleting or suspending the radio resource corresponding to the PDU session. The base station may further send a message to the terminal for instructing the terminal to delete or suspend the radio resource corresponding to the PDU session before deleting or suspending the radio resource corresponding to the PDU session. The base station may further send, to the terminal, a message for instructing the terminal to delete or suspend the radio resource corresponding to the PDU session after receiving the first message sent by the first core network device. The sequence executed by the base station is not specifically limited in this application.

In one possible design, the message for instructing the terminal to delete or suspend the radio resource corresponding to the PDU session carries: the radio resource to be deleted or suspended carries the identity of the DRB.

In a third aspect, an embodiment of the present application provides a session management method, including:

a terminal receives a message which is sent by a base station and used for indicating the terminal to delete or suspend wireless resources corresponding to a PDU session; and the terminal deletes or suspends the wireless resource corresponding to the PDU session and sets the state of the PDU session to be an idle state.

Through the design, after receiving the message sent by the base station, the terminal deletes or suspends the wireless resource corresponding to the PDU session, and sets the state of the PDU session to an idle state. Thereby ensuring the state synchronization of the PDU conversation of the terminal and the base station. The message sent by the base station for instructing the terminal to delete or suspend the radio resource corresponding to the PDU session is triggered in the process of triggering and executing the operation of invalidating the PDU session when no data transmission is monitored on the PDU session and the timer corresponding to the PDU session is continuously timed out. In addition, the trigger may be the base station, the second core network device, or the terminal. In addition, the PDU conversation without data transmission in a period of time is invalid, so that the resource waste caused by the occupation of resources by the PDU conversation without data transmission is avoided.

In one possible design, before setting the status of the PDU session to an idle state, the method further includes:

and judging that all wireless resources corresponding to the PDU session are deleted or suspended. Through the above one mode, after all the radio resources of the PDU session are deleted or suspended, the state of the PDU session is triggered to be set to an idle state, so that the PDU session can be executed based on the state saved in the PDU when the operation is subsequently executed for the PDU session.

In one possible design, before the terminal receives a message sent by a base station to instruct the terminal to delete or suspend radio resources corresponding to a PDU session, the method further includes:

when the PDU session is activated, the terminal receives a timer of the PDU session sent by first core network equipment;

and the terminal monitors that no data is transmitted on the PDU session and continuously sends a first message for invalidating the operation of the PDU session to the first core network equipment when the timer is timed out.

The method for triggering and executing the invalid PDU session by the terminal is provided, so that the terminal triggers and executes the operation of invalidating the PDU session when monitoring that no data is transmitted on the PDU session and continuing to the time-out of the timer, and resource waste caused by the occupation of resources by the PDU session which continuously has no data transmission is avoided.

In one possible design, the operation of invalidating the PDU session includes: and converting the state of the PDU session from an active state to an idle state or deleting the PDU session.

In one possible design, the method may further include:

and when the PDU session is activated, the terminal receives first indication information sent by the first core network equipment, wherein the first indication information is used for indicating the operation of invalidating the PDU session.

In a fourth aspect, an embodiment of the present application provides a session management method, including:

a second core network device receives a message sent by a first core network device, wherein the message carries an identifier of a PDU session to be deleted and is used for indicating the second core network device to delete information related to a base station corresponding to the PDU session corresponding to the identifier or delete the information related to the PDU session;

and the second core network equipment deletes the information related to the base station corresponding to the PDU session or deletes the information related to the PDU session.

Through the design, after receiving the message sent by the base station, the second core network device executes the information related to the base station corresponding to the PDU session or deletes the information related to the PDU session. And the message sent by the first core network device is triggered in the flow of executing the operation of invalidating the PDU session when no data transmission is monitored on the PDU session and the time of the timer corresponding to the PDU session is up. In addition, the monitoring trigger may be a base station, the second core network device, or the terminal. In addition, the PDU conversation without data transmission in a period of time is invalid, so that the resource waste caused by the occupation of resources by the PDU conversation without data transmission is avoided.

In one possible design, the method may further include:

when the PDU session is activated, the second core network equipment receives the timer of the PDU session sent by the first core network equipment;

and the second core network equipment monitors that no data is transmitted on the PDU session and continues to send a first message for invalidating the operation of the PDU session to the first core network equipment until the timer is overtime.

The above design provides a method for triggering and executing the invalidation of the PDU session by the second core network device, so that the second core network device triggers and executes the operation of invalidating the PDU session when monitoring that no data is transmitted in the PDU session and continuing until the timer is overtime, thereby avoiding resource waste caused by resource occupation of the PDU session continuously without data transmission.

In one possible design, the method may further include:

when the PDU session is activated, the second core network device receives indication information sent by the first core network device, wherein the indication information is information indicating the operation of invalidating the PDU session.

In a fifth aspect, an embodiment of the present application further provides a session management method in a cell handover process, including:

in the process of cell switching, the fourth core network equipment receives the PDU session identification sent by the base station;

the fourth core network equipment determines the PDU session needing to update the user plane context based on the identification of the PDU session;

and the fourth core network equipment sends a message for informing the first core network equipment of updating the user plane context of the PDU session to the first core network equipment.

Through the design, in the cell switching process, PDU sessions needing to update the user context are determined, and therefore the first core network equipment is informed to update the user plane context of the PDU sessions. In addition, the PDU session needing to update the user context is the activated PDU session, so that the PDU session updating aiming at the activated state is ensured, and the resource waste caused by updating all the PDU sessions aiming at the terminal in the existing cell switching is avoided.

In one possible design, the method further includes:

the fourth core network device receives a message which is sent by the first core network device and is used for indicating the fourth core network device to set the state of the PDU session to be an idle state or delete the PDU session;

and the fourth core network equipment sets the stored state of the PDU session to be an idle state, or deletes the state information of the PDU session.

Through the design, in the process of invalidating the PDU session, the saved state of the PDU session is set to an idle state, or the state information of the PDU session is deleted, and the execution can be performed based on the state of the PDU session in the subsequent execution operation for the PDU session.

In a sixth aspect, an embodiment of the present application provides a session management method, which is used for synchronizing PDU sessions. The method comprises the following steps:

the terminal determines that uplink data arrives or a paging request is received; the terminal sends a request message to a network device, where the request message carries an identifier of a PDU session and/or first state information of a QoS flow corresponding to the PDU session, and the first state information indicates that a state of the QoS flow on the terminal is an active state or an inactive state, and is used for the network device and the terminal to synchronize the state of the QoS flow.

Through the design, when the terminal determines that uplink data arrives or receives a paging request, the terminal sends the state of the QoS flow corresponding to the PDU session to be synchronized to the network equipment, and the state of the QoS flow is synchronized by the network equipment and the terminal.

In a possible design, the radio resource control RRC state of the terminal is an RRC inactive connection state, the network device is a base station, and the request message is used to instruct to resume the RRC connection of the terminal. The method may further comprise:

the terminal receives second state information of a QoS flow corresponding to the PDU session, wherein the second state information indicates that the state of the QoS flow on the base station is an activated state or an inactivated state;

and the terminal synchronizes the state of the QoS flow corresponding to the PDU session with the base station based on the second state information.

Through the design, the base station sends the state information of the activated PDU session to the terminal after executing the QoS flow of the activated PDU session, so that the terminal and the base station synchronize the state of the QoS flow of the PDU session.

In a possible design, after the terminal sends a request message to a base station, the terminal receives a mapping relationship between a QoS flow corresponding to the PDU session sent by the base station and a DRB;

and the terminal stores the mapping relation.

In a possible design, the CM state of the connection management of the terminal is an idle state, the network device is a fourth core network device, and the request message is used to instruct to convert the terminal from the CM idle state to the CM connection state. The method may further comprise:

the terminal receives third state information of the QoS flow corresponding to the PDU session, which is sent by the first core network device, wherein the third state information indicates that the state of the QoS flow corresponding to the PDU session on the first core network device is an activated state or an inactivated state;

and the terminal synchronizes the state of the QoS flow corresponding to the PDU session with the first core network equipment based on the third flow state information.

Through the design, when the network device is the fourth core network device, the terminal receives the third state information corresponding to the QoS flow corresponding to the PDU session sent by the first core network device, so that the terminal and the first core network device synchronize the state of the QoS flow, and data transmission errors caused by asynchronous states are avoided.

In a seventh aspect, an embodiment of the present application provides a session management method, including:

a base station receives an RRC connection recovery message sent by the terminal, wherein the RRC connection recovery message carries parameters;

the base station determines a PDU session to be activated according to the parameters;

and the base station triggers and activates the PDU conversation process.

Through the design, the base station determines the PDU session needing to be activated after receiving the RRC connection recovery message, so that the activation operation is only carried out on the needed PDU session, and the resource waste caused by the fact that the activation operation is carried out on all PDU sessions of the terminal in the prior art is avoided.

In a possible design, the parameter is an identifier of the PDU session to be activated or an identifier of a radio resource bearer DRB corresponding to the PDU session to be activated.

The base station comprises the corresponding relation between the PDU conversation and the wireless resource bearing, so that the base station determines the PDU conversation to be activated according to the corresponding relation.

And the state of the PDU session to be activated is an idle state.

In a possible design, the RRC connection recovery message further carries first state information of a quality of service QoS flow corresponding to the PDU session; the state information is used for the base station and the terminal to synchronize the state of the QoS flow.

Wherein, activating the PDU session means activating the QoS flow corresponding to the PDU session.

In one possible design, the base station triggers execution of a procedure for activating the PDU session, including:

and the base station sends a message for triggering the PDU conversation to be converted into an activated state to the first core network equipment.

Through the design, the process of triggering and executing the PDU session to be activated by sending the message for triggering the PDU session to be converted into the activated state is simple and effective.

In one possible design, the method may further include:

and the base station configures the mapping relation between the QoS flow corresponding to the PDU session and the DRB.

Through the design, after the base station triggers and executes the process of activating the PDU session, the PDU session needs to be activated, so that the base station configures the mapping relationship between the QoS flow corresponding to the PDU session and the DRB for the session.

In one possible design, the method may further include:

and the base station sends the mapping relation to the terminal. Therefore, the terminal receives the mapping relation and executes the operation corresponding to the PDU conversation based on the mapping relation.

In one possible design, the method may further include:

and the base station sends the second state information of the QoS flow corresponding to the PDU session to a terminal so as to indicate the state of the QoS synchronization between the terminal and the base station.

The above designs a way for the terminal and the base station to synchronize the QoS status.

In one possible design, the method may further include:

the base station determines to execute cell switching aiming at the terminal;

and the base station sends a switching request message to fourth core network equipment, wherein the switching request message carries the PDU session identifier which corresponds to the terminal and is in an activated state, or the switching request carries the PDU session identifier which corresponds to the terminal and is stored with a PDU session context in the base station.

Through the design, when cell switching is executed, the base station sends a switching request to the fourth core network device, and carries the identifier of the PDU session in the activated state in the request, so that the fourth core network device indicates the SMF corresponding to the PDU session to update the user plane context corresponding to the PDU session in the activated state.

In an eighth aspect, an embodiment of the present application provides a session management method, including:

a first core network device receives a service request message sent by a terminal, wherein the service request message carries an identifier of a PDU session to be activated;

and the first core network equipment executes the flow of activating the PDU session based on the service request message.

Through the design, the terminal sends the identification of the PDU session needing to be activated to the first core network equipment, and the first core network equipment only aims at the PDU session needing to be activated and does not need to activate all PDU sessions of the terminal, so that the occupation of resources is reduced.

In a possible design, the service request message carries first state information of a quality of service QoS flow corresponding to the PDU session; the first state information indicates that the state of the QoS flow corresponding to the PDU session on the terminal is an active state or an inactive state, and is used for the first core network device and the terminal to synchronize the state of the QoS flow.

In the design, the first core network device sends the state of the QoS flow corresponding to the PDU session to the terminal, so that the terminal and the first core network device synchronize the state of the QoS flow, and data transmission errors caused by state asynchronism are avoided.

In one possible design, the method may further include:

the first core network device sends third state information of the QoS flow corresponding to the PDU session to the terminal so as to indicate that the terminal and the first core network device synchronize the state of the QoS flow corresponding to the PDU session; the third status information indicates that the status of the QoS flow corresponding to the PDU session on the first core network device is an active status or an inactive status.

In the design, the terminal sends the state of the QoS flow corresponding to the PDU session to the first core network device, so that the first core network device and the terminal synchronize the state of the QoS flow, and data transmission errors caused by asynchronous states are avoided.

Based on the same inventive concept as the method embodiment, the embodiment of the present application further provides a session management device, where beneficial effects of the method and the device are mutually referred to, and are not described herein again.

In a ninth aspect, an embodiment of the present application provides a session management apparatus, where the session management apparatus is applied to a first device, and the apparatus includes:

a receiving module for receiving a request message for activating a packet data unit, PDU, session;

a sending module, configured to send the timer of the PDU session to a second device;

the receiving module is further configured to receive a first message initiated by the second device to invalidate the operation of the PDU session; the first message is issued by the second device detecting no data transmission on the PDU session and persisting until the timer times out.

In a possible design, the first device is a first core network device, and the second device is a second core network device, or a base station, or a terminal.

In one possible design, the operation of invalidating the PDU session includes: and converting the PDU session from an active state to an idle state or deleting the PDU session.

In one possible design, further comprising:

a first determining module, configured to determine a timer of the PDU session based on slice information of a network slice to which the PDU session belongs, before the sending module sends the timer to the second device.

In a possible design, the receiving module is further configured to receive a timer of the PDU session sent by a third core network device.

In a possible design, the sending module is further configured to send, to the second device, indication information, where the indication information is information used to indicate that the operation of the PDU session is not valid.

In a possible design, the receiving module is further configured to receive, after receiving the request message, indication information sent by a third core network device, where the indication information is information used to indicate that the operation of the PDU session is disabled.

In a possible design, the second determining module is configured to determine, based on the indication information, that the PDU session is to be deactivated, based on the indication information, to switch the PDU session from an active state to an idle state or to delete the PDU session.

In one possible design, the first message carries an identifier of the PDU session.

In one possible design, the first message further carries a cause value indicating that a timer for the PDU session expires.

In a possible design, the operation of invalidating the PDU session is to convert the PDU session from an active state to an idle state, and the receiving module is further configured to send, after receiving the first message, a message for instructing to delete the information related to the base station and corresponding to the PDU session to the second core network device.

In one possible design, the deactivating the PDU session is operable to transition the PDU session from an active state to an idle state, the apparatus further comprising:

and the processing module is used for setting the state of the PDU conversation to be an idle state after the first message is received.

In a possible design, the operation of invalidating the PDU session is to delete the PDU session, and the sending module is further configured to send, to the second core network device, a message indicating to delete the information related to the PDU session after the receiving module receives the first message.

In a possible design, the operation of invalidating the PDU session is deleting the PDU session, and the sending module is further configured to send, to the terminal, a message for instructing the terminal to delete the information related to the PDU session after receiving the first message.

In a possible design, the sending module is further configured to send, to the base station, a message for instructing the base station to release the context of the PDU session after the receiving module receives the first message.

In a possible design, the sending module is further configured to send, to a fourth core network device, a message for instructing the fourth core network device to set the status of the PDU session to an idle status after the receiving module receives the first message.

In a possible design, the receiving module is further configured to receive a second message sent by a fourth core network device, where the second message carries an identifier of a PDU session of a user plane context to be updated;

the device further comprises:

and the updating module is used for updating the user plane context of the PDU session corresponding to the identification of the PDU session.

In a tenth aspect, an embodiment of the present application provides a session management apparatus, where the apparatus is applied to a base station, and the apparatus includes:

the device comprises a receiving module, a sending module and a receiving module, wherein the receiving module is used for receiving a PDU session timer sent by first core network equipment when the PDU session is activated;

a processing module for detecting that there is no data transmission on the PDU session and continuing until the timer times out;

the sending module is configured to send a first message to the first core network device, where the first message invalidates the operation of the PDU session.

In a possible design, the receiving module is further configured to receive, when a PDU session is activated, indication information sent by the first core network device, where the indication information is information used to indicate that the operation of the PDU session is disabled.

In one possible design, the first message carries an identification of the PDU session.

In one possible design, the first message further carries a cause value, and the cause value is used to indicate that a timer of the PDU session expires.

In a possible design, the receiving module is further configured to receive a message, sent by the first core network device, for instructing the base station to release the context of the PDU;

the processing module is further configured to delete or suspend the radio resource corresponding to the PDU session.

In one possible design, the processing module is further configured to:

and setting the saved state of the PDU conversation to be an idle state.

In a possible design, the processing module is further configured to delete the mapping relationship between the QoS flow corresponding to the PDU session and the DRB after monitoring that there is no data transmission in the PDU session and continuing until the timer expires.

In a possible design, the sending module is further configured to send, to the terminal, a message for instructing the terminal to delete or suspend radio resources corresponding to the PDU session after the processing module monitors that there is no data transmission on the PDU session and continues until the timer expires.

In an eleventh aspect, an embodiment of the present application provides a session management apparatus, where the apparatus is applied to a terminal, and the apparatus includes:

a receiving module, configured to receive a message sent by a base station, where the message is used to instruct the terminal to delete or suspend a radio resource corresponding to a PDU session;

and the processing module is used for deleting or suspending the wireless resources corresponding to the PDU session and setting the state of the PDU session to be an idle state.

In a possible design, the processing module is further configured to set the status of the PDU session to an idle status when the receiving module receives a message that is sent by the base station and used to instruct the terminal to delete or suspend the radio resource corresponding to the PDU session and determines that all the radio resources corresponding to the PDU session are deleted or suspended.

In a possible design, the receiving module is further configured to receive, before receiving a message sent by a base station and used to instruct the terminal to delete or suspend radio resources corresponding to a PDU session, a timer of the PDU session sent by a first core network device when the PDU session is activated;

the device further comprises:

and the sending module is further configured to send a first message for invalidating the operation of the PDU session to the first core network device when the processing module monitors that no data is transmitted on the PDU session and continues until the timer times out.

In a possible design, the receiving module is further configured to receive, when the PDU session is activated, first indication information sent by the first core network device, where the first indication information is information used to indicate that the operation of the PDU session is not valid.

In a twelfth aspect, an embodiment of the present application provides a session management apparatus, where the session management apparatus is applied to a second core network device, and the session management apparatus includes:

a receiving module, configured to receive a message sent by a first core network device, where the message carries an identifier of a PDU session to be deleted, and is used to instruct a second core network device to delete information related to a base station corresponding to the PDU session corresponding to the identifier or delete information related to the PDU session;

and the processing module is used for deleting the information related to the base station corresponding to the PDU session or deleting the information related to the PDU session.

In a possible design, the receiving module is further configured to receive a timer of the PDU session sent by the first core network device when the PDU session is activated;

the device further comprises:

and the sending module is used for monitoring that no data is transmitted on the PDU session at the processing module, and sending a first message for invalidating the operation of the PDU session to the first core network equipment when the timer is overtime.

In a possible design, the receiving module is further configured to receive, when a PDU session is activated, indication information sent by the first core network device, where the indication information is information indicating that the operation of the PDU session is disabled.

In a thirteenth aspect, an embodiment of the present application provides a session management apparatus, where the session management apparatus is applied to a fourth core network device, and the session management apparatus includes:

a receiving module, configured to receive, during a cell handover process, an identifier of a PDU session sent by a base station;

the processing module is used for determining the PDU session needing to update the user plane context based on the identification of the PDU session;

a sending module, configured to send, to a first core network device, a message for notifying the first core network device to update a user plane context of the PDU session.

In one possible design, the receiving module is further configured to:

receiving a message which is sent by first core network equipment and used for indicating the fourth core network equipment to set the state of the PDU session to be an idle state or delete the PDU session;

the processing module is further configured to set the stored state of the PDU session to an idle state, or delete the state information of the PDU session.

In a fourteenth aspect, an embodiment of the present application provides a session management method, where the session management method is applied to a terminal, and the session management method includes:

the processing module is used for determining that uplink data arrives or a paging request is received;

a sending module, configured to send a request message to a network device, where the request message carries an identifier of a PDU session and/or first state information of a QoS flow corresponding to the PDU session, and the first state information indicates that a state of the QoS flow on the terminal is an active state or an inactive state, and is used for the network device and the terminal to synchronize a state of the QoS flow.

In a possible design, the radio resource control RRC state of the terminal is an RRC inactive connection state, the network device is a base station, and the request message is used to instruct to resume the RRC connection of the terminal.

In a possible design, the receiving module is further configured to receive second state information of a QoS flow corresponding to the PDU session, where the second state information indicates that a state of the QoS flow on the base station is an active state or an inactive state;

the processing module is further configured to synchronize, based on the second status information, a status of a QoS flow corresponding to the PDU session with the base station.

In a possible design, the receiving module is further configured to receive a mapping relationship between a QoS flow corresponding to the PDU session and a DRB sent by the base station;

the processing module is further configured to store the mapping relationship.

In a possible design, the CM state of the connection management of the terminal is an idle state, the network device is a fourth core network device, and the request message is used to instruct to convert the terminal from the CM idle state to the CM connection state.

In a possible design, the receiving module is further configured to receive third status information of the QoS flow corresponding to the PDU session, where the third status information indicates that a status of the QoS flow corresponding to the PDU session on the first core network device is an active status or an inactive status;

the processing module is further configured to synchronize, based on the third flow state information, a state of a QoS flow corresponding to the PDU session with the first core network device.

In a fifteenth aspect, an embodiment of the present application provides a session management apparatus, where the apparatus is applied to a base station, and the apparatus includes:

a receiving module, configured to receive an RRC connection recovery message sent by the terminal, where the RRC connection recovery message carries parameters;

the processing module is used for determining the PDU session to be activated according to the parameters; and triggering the flow of activating the PDU session.

In one possible design, the state of the PDU session to be activated is an idle state.

In one possible design, the apparatus further includes:

and the sending module is used for sending a message for triggering the conversion of the PDU session into the activated state to the first core network equipment.

In a possible design, the processing module is further configured to configure a mapping relationship between a QoS flow corresponding to the PDU session and a DRB.

In one possible design, further comprising:

and the sending module is further used for sending the mapping relation to the terminal.

In one possible design, the apparatus further includes:

and the sending module is used for sending the second state information of the QoS flow corresponding to the PDU session to a terminal so as to indicate the state of the QoS synchronization between the terminal and the base station.

In one possible design, the processing module is further configured to determine to perform cell handover for the terminal;

a sending module, configured to send a handover request message to a fourth core network device, where the handover request message carries an identifier of a PDU session that is in an active state and corresponds to the terminal, or the handover request carries an identifier of a PDU session that is in an active state and corresponds to the terminal and is stored in the base station with a PDU session context.

In a sixteenth aspect, an embodiment of the present application provides a session management apparatus, where the session management apparatus is applied to a first core network device, and the session management apparatus includes:

a receiving module, configured to receive a service request message sent by a terminal, where the service request message carries an identifier of a PDU session to be activated;

and the processing module is used for executing the flow of activating the PDU session based on the service request message.

In a possible design, the service request message carries first state information of a quality of service QoS flow corresponding to the PDU session; the first state information indicates that the state of the QoS flow corresponding to the PDU session on the first core network device is an active state or an inactive state, and is used for the first core network device and the terminal to synchronize the state of the QoS flow.

In one possible design, the apparatus further includes:

a sending module, configured to send, to the terminal, third state information of a QoS flow corresponding to the PDU session, so as to indicate that the terminal and the first core network device synchronize a state of the QoS flow corresponding to the PDU session; the third status information indicates that the status of the QoS flow corresponding to the PDU session on the first core network device is an active status or an inactive status.

In a seventeenth aspect, an embodiment of the present application further provides a first core network device, where the first core network device includes a communication interface, a processor, and a memory, where the communication interface is used to transmit and receive data, the memory is used to store a software program, and the processor is used to read the software program stored in the memory and implement the method provided by the first aspect or any design of the first aspect, or implement the method provided by any design of the eighth aspect or the eighth aspect.

In an eighteenth aspect, an embodiment of the present application further provides a second core network device, where the second core network device includes a communication interface, a processor, and a memory, where the communication interface is used to transmit and receive data, the memory is used to store a software program, and the processor is used to read the software program stored in the memory and implement the method provided in the fourth aspect or any design of the foregoing fourth aspect.

In a nineteenth aspect, an embodiment of the present application provides a fourth core network device, where the fourth core network device includes a communication interface, a processor, and a memory, the communication interface is used to transmit and receive data, the memory is used to store a software program, and the processor is used to read the software program stored in the memory and implement the method provided in the fifth aspect or any one of the designs of the fifth aspect.

In a twentieth aspect, an embodiment of the present application provides a terminal, where the terminal includes a transceiver, a processor and a memory, the transceiver is configured to transceive data, the memory is configured to store a software program, and the processor is configured to read the software program stored in the memory and implement the third aspect or the method provided by any design of the foregoing third aspect, or the method provided by the sixth aspect or any design of the foregoing sixth aspect.

In a twenty-first aspect, an embodiment of the present application provides a base station, where the base station includes a transceiver, a processor, and a memory, where the transceiver is configured to transceive data, and the memory is configured to store a software program, and the processor is configured to read the software program stored in the memory and implement the second aspect or the method provided in any design of the foregoing second aspect, or the method provided in the seventh aspect or any design of the foregoing seventh aspect.

In a twenty-second aspect, this embodiment of the present application further provides a computer storage medium, where a software program is stored, and when the software program is read and executed by one or more processors, the software program may implement the method provided in any one of the first to eighth aspects or any one of the first to eighth aspects.

In a twenty-third aspect, an embodiment of the present application further provides a session management method, including:

when a PDU session of a terminal is established or activated, a source base station which the terminal is currently accessed to receives a timer of the PDU session sent by first core network equipment; if the source base station detects that no data transmission continues on the PDU session until the timer is overtime, recording the state of the PDU session as an inactive state;

when the source base station determines to execute the switching from the source base station to the target base station aiming at the terminal, determining a first class of PDU session included in the activated PDU session of the terminal, wherein the first class of PDU session is recorded as an inactive state PDU session, and executing a switching process aiming at a second class of PDU session, wherein the second class of PDU session is a PDU session of the terminal except the first class of session.

Through the design, the source base station monitors the timer of the PDU conversation of the terminal, does not execute the switching process aiming at the PDU with overtime timer, and only executes the switching aiming at the PDU conversation with non-overtime timer, thereby avoiding the resource waste caused by the occupation of resources by the PDU conversation without data transmission.

In one possible design, the source base station performs a handover procedure for the second type PDU session, including:

the source base station sends a switching request to the target base station, wherein the switching request only carries the identification of the second PDU session; alternatively, the first and second electrodes may be,

the switching request carries the identification of the first PDU conversation and the identification of the second PDU conversation; alternatively, the first and second electrodes may be,

the switching request carries an identifier of the activated PDU session of the terminal and a first indication, and the first indication is used for marking the first class PDU session in the activated PDU session of the terminal.

The above provides a switching method based on XN.

In one possible design, the method further includes:

in the process of executing switching aiming at the second type PDU conversation, the source base station sends a message for instructing the terminal to execute the operation of invalidating the first type PDU conversation to the terminal.

In one possible design, the message for instructing the terminal to perform the operation of invalidating the PDU sessions of the first type carries: an identification of the first type PDU session; alternatively, the first and second electrodes may be,

the message for instructing the terminal to execute the operation of invalidating the first-class PDU session carries: the terminal comprises an identification of the terminal's active PDU sessions and a first indication, wherein the first indication is used for identifying the first class of PDU sessions in the terminal's active PDU sessions.

In one possible design, the operation of invalidating the PDU sessions of the first type includes: and converting the state of the first type PDU conversation from an active state to an idle state or deleting the first type PDU conversation.

the source base station sends a switching request to fourth core network equipment, wherein the switching request only carries the identification of the second PDU session; alternatively, the first and second electrodes may be,

In a twenty-fourth aspect, an embodiment of the present application provides a session management method, including:

a target base station to be switched in by a terminal receives a switching request sent by a source base station to which the terminal is currently accessed, wherein the switching request only carries an identifier of the second PDU session; or, the switching request carries the identifier of the first type PDU session and the identifier of the second type PDU session; or, the handover request carries an identifier of an activated PDU session of the terminal and a first indication, where the first indication is used to mark a first type of PDU session in the identifier of the activated PDU session of the terminal;

wherein, each active PDU session of the terminal is configured with a corresponding timer when being established or activated; the first type of PDU session is a PDU session recorded in an inactive state; the PDU session recorded as inactive refers to the PDU session which meets the condition that no data transmission continues until the corresponding timer is overtime; the second PDU session is the PDU session except the PDU session marked as the active state in the activated PDU session of the terminal;

and the target base station sends a message for indicating the fourth core network equipment to execute the operation of invalidating the first-class PDU session to the fourth core network equipment.

In a possible design, the message for instructing the fourth core network device to perform the operation of invalidating the PDU session of the second type carries: identification of the first type PDU session.

In a twenty-fifth aspect, an embodiment of the present application provides a session management method, including:

in the process that the terminal is switched from the source base station to the target base station, the fourth core network equipment receives the identifier of the second PDU session sent by the source base station or the target base station;

wherein, each active PDU session of the terminal is configured with a corresponding timer when being established or activated; the second type of PDU session is the PDU session except the PDU session recorded in the inactive state in the activated PDU session of the terminal, and the PDU session recorded in the inactive state is the PDU session which meets the condition that no data transmission lasts until the corresponding timer is overtime;

and the fourth core network equipment sends a message for informing the first core network equipment of updating the context of the second PDU session to the first core network equipment.

Through the design, the fourth core network only executes the context updating aiming at the second type PDU conversation, thereby avoiding the resource waste caused by the resource occupation of the PDU conversation without data transmission.

In a possible design, the receiving, by the fourth core network device, the identifier of the PDU session of the second type sent by the target base station includes:

and the fourth core network equipment receives a path switching message sent by the target base station, wherein the path switching message carries the identifier of the second PDU session.

In a possible design, the receiving, by the fourth core network device, an identifier of a PDU session of the second type sent by the source base station includes:

and the fourth core network equipment receives a switching request sent by the source base station, wherein the switching request carries the identifier of the second PDU session.

In one possible design, the method further includes:

the fourth core network device determines a first class PDU session based on the identifier of the second class PDU session, wherein the first class PDU session is a PDU session which is saved by the fourth core network device and is activated by the terminal and is other than the second class PDU session corresponding to the identifier;

and the fourth core network equipment sends a message for indicating to execute the operation of invalidating the first-class PDU session to the first core network equipment.

In one possible design, the operation of invalidating the PDU sessions of the first type includes converting the status of the PDU sessions of the first type from an active status to an idle status or deleting the PDU sessions of the first type.

In one possible design, after the fourth core network device determines the first type PDU session based on the identifier of the first type PDU session, the method further includes:

and the fourth core network equipment converts the state of the first type PDU conversation from an active state to an idle state or deletes the first type PDU conversation.

In one possible design, the method further includes:

the fourth core network device receives an identifier of a third type PDU session sent by the source base station or the target base station, wherein the third type PDU session is the PDU session recorded in the inactive state;

and the fourth core network equipment sends a message for indicating to execute the operation of invalidating the third-class PDU session to the first core network equipment.

In one possible design, the operation of invalidating the PDU sessions of the third type includes:

and converting the state of the third PDU session from an active state to an idle state or deleting the third PDU session.

In a possible design, after the fourth core network device receives an identifier of a PDU session of a third type sent by the source base station or the target base station, the method further includes:

and the fourth core network equipment converts the state of the third PDU session from an active state to an idle state or deletes the third PDU session.

and the fourth core network device sends the identifier of the third PDU session to the terminal, and is used for indicating the terminal to set the state of the third PDU session to an idle state.

In a twenty-sixth aspect, an embodiment of the present application provides a session management method, including:

in the process that a terminal is switched to a target base station from a source base station which is accessed currently, the terminal receives a message which is sent by the source base station or fourth core network equipment and used for indicating to execute the operation of invalid first-class Packet Data Unit (PDU) conversation;

wherein, each active PDU session of the terminal is configured with a corresponding timer when being established or activated; the first type of PDU session is a PDU session recorded in an inactive state; the PDU session recorded as inactive refers to the PDU session which meets the condition that no data transmission continues until the corresponding timer is overtime;

and the terminal performs the operation of invalidating the first class PDU session based on the message.

In one possible design, the message for instructing the terminal to perform the operation of invalidating the first type packet data unit PDU session carries: identification of the first type of PDU session.

In one possible design, the message for instructing to perform the operation of invalidating the first type packet data unit PDU session carries: the terminal comprises an identification of the terminal's active PDU sessions and a first indication, wherein the first indication is used for marking the first class PDU session in the terminal's active PDU sessions;

the terminal performs the operation of invalidating the first type PDU session based on the message, including:

and the terminal determines the first class PDU session in the activated PDU sessions of the terminal according to the first indication and executes the operation of invalidating the first class PDU session.

In one possible design, the operation of invalidating the PDU sessions of the first type includes:

and converting the state of the first type PDU conversation from an active state to an idle state or deleting the first type PDU conversation.

In a twenty-seventh aspect, an embodiment of the present application provides a session management apparatus, where the apparatus is applied to a source base station, and the apparatus includes:

the receiving module is used for receiving a PDU session timer sent by first core network equipment when the PDU session of a terminal is established or activated; if the source base station detects that no data transmission continues on the PDU session until the timer is overtime, recording the state of the PDU session as an inactive state;

the processing module is configured to determine a first type of PDU session included in an activated PDU session of the terminal when it is determined that handover is performed for the terminal from the source base station to the target base station, where the first type of PDU session is a PDU session recorded in an inactive state, and perform a handover procedure for a second type of PDU session, where the second type of PDU session is a PDU session of the terminal except for the first type of session.

In one possible design, further comprising:

a sending module, configured to send, at the processing module, a handover request to the target base station for a second type PDU session, where the handover request only carries an identifier of the second type PDU session; alternatively, the first and second electrodes may be,

In one possible design, further comprising:

and the sending module is used for sending a message for indicating the terminal to execute the operation of invalidating the first-class PDU session to the terminal in the process of executing the switching aiming at the second-class PDU session.

In one possible design, further comprising:

the sending module is configured to send a handover request to a fourth core network device when the processing module executes a handover procedure for a second type PDU session, where the handover request only carries an identifier of the second type PDU session; alternatively, the first and second electrodes may be,

In a twenty-eighth aspect, an embodiment of the present application provides a session management apparatus, where the apparatus applies a target base station, and includes:

a receiving module, configured to receive a handover request sent by a source base station to which a terminal is currently accessed, where the handover request only carries an identifier of the second type PDU session; or, the switching request carries the identifier of the first type PDU session and the identifier of the second type PDU session; or, the handover request carries an identifier of an activated PDU session of the terminal and a first indication, where the first indication is used to mark a first type of PDU session in the identifier of the activated PDU session of the terminal;

a sending module, configured to send, to a fourth core network device, a message used to instruct the fourth core network device to perform an operation of invalidating the first-class PDU session.

In a twenty-ninth aspect, an embodiment of the present application provides a session management apparatus, where the apparatus is applied to a fourth core network device, and the apparatus includes:

the receiving module is used for receiving the identifier of the second PDU session sent by the source base station or the target base station in the process that the terminal is switched from the source base station to the target base station;

a sending module, configured to send, to a first core network device, a message for notifying the first core network device to update a context of the second type PDU session.

In a possible design, the receiving module is specifically configured to receive a path switching message sent by the target base station, where the path switching message carries an identifier of the second type PDU session.

In a possible design, the receiving module is specifically configured to receive a handover request sent by the source base station, where the handover request carries an identifier of the second type PDU session.

In one possible design, the apparatus further includes:

a processing module, configured to determine a first type PDU session based on an identifier of the second type PDU session, where the first type PDU session is a PDU session that is saved by the fourth core network device and activated by the terminal, and is other than the second type PDU session corresponding to the identifier;

In a possible design, the processing module is further configured to, after determining a first type PDU session based on the identifier of the first type PDU session, convert the state of the first type PDU session from an active state to an idle state or delete the first type PDU session.

In a possible design, the receiving module is further configured to receive an identifier of a PDU session of a third type sent by the source base station or the target base station, where the PDU session of the third type is the PDU session recorded in the inactive state;

the sending module is configured to send, to the first core network device, a message used for instructing to execute an operation of invalidating the third-class PDU session.

In one possible design, the apparatus further includes:

and the processing module is used for converting the state of the third PDU session from an activated state to an idle state or deleting the third PDU session after the receiving module receives the identifier of the third PDU session sent by the source base station or the target base station.

In one possible design, the sending module is further configured to: and after the receiving module receives the identifier of the third PDU session sent by the source base station or the target base station, sending the identifier of the third PDU session to the terminal for indicating the terminal to set the state of the third PDU session to an idle state.

In a thirtieth aspect, an embodiment of the present application provides a session management apparatus, where the apparatus is applied to a terminal, and the apparatus includes:

a receiving module, configured to receive, during a process that a terminal is switched from a currently accessed source base station to a target base station, a message sent by the source base station or a fourth core network device and used to instruct execution of an operation of invalidating a first type of packet data unit PDU session;

and the processing module is used for executing the operation of invalidating the first type PDU session based on the message.

In a thirty-first aspect, an embodiment of the present application further provides a fourth core network device, where the fourth core network device includes a communication interface, a processor, and a memory, the communication interface is used to receive and transmit data, the memory is used to store a software program, and the processor is used to read the software program stored in the memory and implement the twenty-fifth aspect or the method provided by any design of the twenty-fifth aspect.

In a thirty-sixth aspect, an embodiment of the present application provides a terminal, where the terminal includes a transceiver, a processor, and a memory, where the transceiver is configured to transmit and receive data, the memory is configured to store a software program, and the processor is configured to read the software program stored in the memory and implement the method provided in the twenty-sixth aspect or any design of the twenty-sixth aspect.

In a thirty-third aspect, an embodiment of the present application provides a base station, where the base station includes a transceiver, a processor, and a memory, where the transceiver is configured to transceive data, and the memory is configured to store a software program, and the processor is configured to read the software program stored in the memory and implement the method provided by the twenty-third aspect or any design of the twenty-fourth aspect, or any design of the twenty-fourth aspect.

Drawings

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

FIG. 1B is a schematic diagram of another system architecture according to an embodiment of the present application;

FIG. 2 is a state diagram provided in accordance with an embodiment of the present application;

fig. 3 is a schematic diagram of a session management method according to an embodiment of the present application;

fig. 4A is a schematic diagram of a timer configuration method according to an embodiment of the present application;

fig. 4B is a schematic diagram of another timer configuration method according to an embodiment of the present application;

fig. 4C is a schematic diagram of another timer configuration method according to an embodiment of the present application;

fig. 5A is a schematic diagram of a timer triggering method according to an embodiment of the present application;

fig. 5B is a schematic diagram of another timer triggering method according to an embodiment of the present application;

fig. 5C is a schematic diagram of another timer triggering method according to an embodiment of the present application;

fig. 6A is a schematic diagram of state synchronization provided in an embodiment of the present application;

fig. 6B is a schematic diagram of another state synchronization provided in the present embodiment;

fig. 7 is a schematic diagram of a cell handover method according to an embodiment of the present application;

fig. 8A to 8C are schematic diagrams of a first core network device according to an embodiment of the present application;

fig. 9A to 9E are schematic diagrams of a base station according to an embodiment of the present application;

fig. 10A to 10D are schematic diagrams of terminals provided in the embodiment of the present application;

fig. 11A to 11B are schematic diagrams of a second core network device according to an embodiment of the present application;

fig. 12A to 12C are schematic diagrams of a fourth core network device according to an embodiment of the present application;

fig. 13 is a schematic diagram illustrating a method for triggering a timer in a base station handover of a terminal according to an embodiment of the present application;

fig. 14A to 14C are schematic diagrams illustrating a base station handover method of a terminal according to an embodiment of the present application.

Detailed Description

The embodiments of the present application may be applicable to a 4G (fourth generation mobile communication system) Evolution system, such as an LTE (Long Term Evolution) system, or may also be applicable to a 5G (fifth generation mobile communication system) system, such as an access network using a New radio access technology (New RAT); communication systems such as a CRAN (Cloud Radio Access Network ).

Fig. 1A illustrates a system architecture diagram applicable to the embodiment of the present application. It should be understood that the embodiments of the present application are not limited to the system shown in fig. 1A, and the apparatus in fig. 1A may be hardware, software divided from functions, or a combination of the two. As shown in fig. 1A, a system architecture provided in the embodiment of the present application includes a terminal, a base station, a first core network device, a second core network device, a third core network device, and a fourth core network device. The terminal can communicate with the first core network device, the second core network device and the fourth core network device through the base station. The first core network device and the fourth core network device are communicated with each other, and in addition, the first core network device and the fourth core network device may be collectively referred to as a control plane network element. The fourth core network device is connected with the third core network device through a communication interface.

The Control Plane network element (CP) may include all or part of an Authentication and Mobility Management Entity (AMF), a Session Management Function Entity (SMF), an SDN controller, a gateway Control Plane (GW-C), a Mobility Management Entity (MME), or a Control Function formed by fusing the above network elements. The control plane network element is responsible for mobility management and forwarding path management in the mobile network, for example, a message forwarding policy is issued to a forwarding plane gateway (GW-U), and the GW-U is instructed to process and forward a message according to the message forwarding policy. The AMF is responsible for UE authentication and mobility management, NAS message routing, SMF selection and the like; and the SMF is responsible for session management, such as session creation, modification and deletion. UPF selection, UE IP address assignment, etc. Referring to the specific system architecture shown in fig. 1B, the first core network device is an SMF, and the fourth core network device is an AMF, for example, in the following description of the present application, the first core network device is an SMF, and the fourth core network device is an AMF.

The second core network device may be a forwarding Plane network element (UPF), as shown in fig. 1B. The UPF is responsible for message processing and forwarding. The forwarding plane function of a Packet Data Network (PDN) Gateway (GW), the forwarding plane function of a Serving gateway (S-GW), a router, a switch, and other physical or virtual forwarding devices may be used.

The third core network device may be a Policy control Function entity (PCF) or a Policy and Charging Rules Function entity (PCRF). Wherein, the PCF or PCRF is responsible for policy control decision and flow charging based control. The third core network device may also be a Subscriber Data Management entity (SDM), or a Home Subscriber Server (HSS). The User Data Management entity english may also correspond to User Data Management, or UDM for short. SDM, UDM or HSS are used to help operators achieve a uniform management of all user-related data.

The base station may also be called AN Access Node (AN), as shown in fig. 1B, and provides a wireless Access service for the terminal. The Access Node may be specifically a Base Transceiver Station (BTS) in a Global System for Mobile communication (GSM) System or a Code Division Multiple Access (CDMA) System, may also be a Base Station (NodeB) in a Wideband Code Division Multiple Access (WCDMA) System, may also be an evolved Node B (eNB) or eNodeB) in an LTE System, or may be a Base Station device, a small Base Station device, a wireless Access Node (WiFi AP), a wireless interworking Microwave Access Base Station (WiMAX BS) in a future 5G network, and the like, which is not limited in this application.

A terminal may also be referred to as an access terminal, User Equipment (UE), a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a User terminal, a wireless communication device, a User agent, or a User Equipment. Fig. 1B illustrates a UE as an example. The terminal may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with Wireless communication function, a computing device or other processing device connected to a Wireless modem, a vehicle-mounted device, a wearable device, an internet of things terminal device, such as a fire detection sensor, an intelligent water meter/electricity meter, a factory monitoring device, and so on.

In addition, the system architecture may further include a Network Application Function (AF), a user Data Management entity (SDM), and a Data Network (DN), as shown in fig. 1B.

The Data Network (DN) provides Data transmission Service for users, and may be a PDN Network, such as the Internet (Internet), IP Multimedia Service (IMS), and so on.

And the AF is mainly used for carrying out dynamic policy/charging control on the forwarding plane behavior. These services require dynamic policy and charging control. The AF transmits dynamic session information needed by the PCF, receives specific information of the IP connectivity access network (IP-CAN) and acknowledgements of IP-CAN bearer layer events.

In the present application, the plurality of the present invention means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. Meanwhile, it should be understood that although the terms first, second, third, etc. may be used to describe various messages, requests, devices and core network devices in the embodiments of the present application, these messages, requests, devices and core network devices should not be limited to these terms. These terms are only used to distinguish messages, requests, devices, and core network devices from one another.

In addition, the PDU session in the embodiment of the present application relates to two states: an idle state and an active state. Wherein, the state of the PDU session is used for describing the user plane connection condition of the PDU session between the UE and the UPF. The specific name may be a session management state, a session connection state, or other possible names describing a session state, and the specific name of the PDU session state is not limited in the present invention. The state of PDU session is stored in UE and SMF, and also stored in AMF and UPF.

The idle state refers to that a user plane connection between the UE and the UPF does not exist in the PDU session, and may specifically be a combination of one or more of the following operations:

1. the UPF deletes or suspends information corresponding to the base station side in the NG3 interface (e.g., IP address, tunnel id, port number, etc. of the base station, so that the UPF cannot be sent to the base station after the downlink data arrives at the UPF).

2. The base station may delete or suspend the radio resource corresponding to the PDU session (the radio resource in the present invention may be a time-frequency resource for carrying data corresponding to the PDU session, or a radio resource configuration DRB, or a combination thereof), and delete or suspend the NG3 interface.

3. And the UE deletes or suspends the corresponding wireless resources according to the configuration of the base station.

The active state means that a PDU session exists in a user plane connection between the UE and the UPF, including an air interface connection between the UE and the base station and a connection of an NG3 interface between the base station and the UPF, and when uplink and downlink data arrive in the active state, the PDU session can be directly transmitted between the UE and the UPF.

The embodiment of the application provides a Session management method and a Session management device, wherein a timer is configured for each PDU Session and is used for monitoring the operation of triggering and executing the invalid PDU Session when no data transmission continues on the PDU Session and the timer is overtime, wherein the operation of the invalid PDU Session can be the execution of the PDU Session to enter an idle state, and can also be the deletion of the PDU Session, so that an implementation mode for realizing the conversion of the state of the PDU Session from an active state to the idle state is provided.

The state of PDU Session (Session) is stored in the SMF on the UE, the base station (AN) and the core network side, each PDU Session has a different state, and different SMFs manage different PDU sessions, as shown in fig. 2, SMF a is used for managing Session a and Session B, and SMF B is used for managing Session C. The state of a PDU session is divided into two states, IDLE (IDLE) and ACTIVE (ACTIVE).

The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

Fig. 3 is a schematic flow chart of a session management method according to an embodiment of the present application.

S301, the SMF receives a request message for activating a PDU session.

It should be noted that activating the PDU session may be establishing the PDU session, or may be a PDU session that is switched from an idle state to an active state, or may be creating the PDU session when performing handover (specifically, may be a PDU session that is created when a non-3GPP (non-3GPP) session is mapped to a 3GPP session from the non-3GPP session when a UE is handed over from the non-3GPP network to the 3GPP network).

S302, the SMF sends a Timer (Timer) of the PDU session to the second device.

And S303, after receiving the timer of the PDU session, the second device sends a first message for invalidating the operation of the PDU session to the first core network device when detecting that no data is transmitted on the PDU session and the timer is over.

It should be noted that the timer may be started when no data is transmitted within a predetermined time after each PDU session transmits data, and the first message is triggered to be sent when no data is transmitted within the time period from the time when the timer is started until the time is out. The timer may also be started after each data transmission of the PDU session, and then the sending of the first message is triggered when no data is transmitted during the time period from the timer being started until the time-out. In addition, the timer is reset if data is sent on the PDU session during the period of time open to timeout.

In this embodiment of the present application, the second device may be a UPF, a base station, or a terminal. That is, the operation of triggering invalidation of the PDU session may be performed by the second core network device, or may be performed by the base station, or may be performed by the terminal.

The operation of invalidating the PDU session may be to convert the status of the PDU session from an active state to an idle state, or may be to delete the PDU session.

The following takes the PDU session setup time configuration timer as an example for specific description, that is, the request message is a PDU session setup request message.

Referring to fig. 4A to 4C, fig. 4A is a schematic diagram of AN SMF configuring a timer of a PDU session to AN, fig. 4B is a schematic diagram of AN SMF configuring a timer of a PDU session to a UPF, and fig. 4C is a schematic diagram of AN SMF configuring a timer of a PDU session to a UE.

The SMF configures the timer of the PDU session to the base station, as shown in fig. 4A:

s401a, the UE sends a PDU session Setup Request (PDU session Setup Request) message to the SMF.

S402a, the SMF performs the PDU Session Authorization with the SDM. Specifically, the SMF acquires subscription information related to a Session from the SDM, such as Access Point Name (APN) information, Data Network Name (DNN), Session and Service Continuity (SSC) mode, and authenticates a PDU Session requested by the UE according to the subscription information.

S403a, performing Policy Retrieval (Policy Retrieval) between the SMF and the PCF. Specifically, the SMF obtains a QoS policy, a charging policy, and the like corresponding to the PDU session from the PCF.

S404a, the SMF configures a timer for the PDU session. For example: the SMF serves a specific network slice, and configures a corresponding timer, which may be referred to as a Session active timer, according to the network slice of the service. The network slice is a logical entity of network division for providing customized network service by an operator in 5G, and may be specifically divided according to a service type of the service, such as a slice supporting Mobile broadband (MBB) service and a slice supporting Internet of Things (IOT). Or may be partitioned according to different network tenants, such as a network specifically provided for some large enterprises or organizations.

Optionally, the timer may also be configured for the PDU session by the PCF according to the policy information to which the PDU session belongs, and send the timer to the SMF. Or the timer is obtained by the SMF from the subscription information.

S405a, the SMF sends the timer to the AN.

Specifically, the SMF may carry the timer in a PDU Session Setup Request (PDU Session Setup Request) message or a PDU Session Setup Accept (PDU Session Setup Accept) message, and send the PDU Session Setup Accept message to the AN, which is illustrated in fig. 4A by taking the PDU Session Setup Accept message as AN example.

Optionally, the SMF may further obtain, from the PCF, information indicating an operation to invalidate the PDU session that needs to be performed when the timer of the PDU session expires.

In a possible implementation manner, the SMF may further send the obtained indication information indicating that the operation of the PDU session is invalidated to the AN, so that when the AN monitors that there is no data transmission on the PDU session, the AN may trigger sending a message indicating whether to convert the PDU session state into AN idle state or delete the PDU session to the SMF. Specifically, the SMF may carry the indication message in a PDU Session Accept message and send the PDU Session Accept message to the AN. The indication information may be used to indicate to convert the status of the PDU Session into an idle state (SM handling for Session idle) or to indicate to delete the PDU Session (delete Session).

In addition, when the SMF does not send the indication information to the AN, when receiving a message which is sent by the AN and detects that no data is transmitted on the PDU session and lasts until the timer times out and invalidates the operation of the PDU session, the SMF determines to execute to convert the PDU session state into AN idle state or to execute to delete the PDU session according to the indication information acquired from the PCF.

The following describes the flow of the SMF configuring the timer of the PDU session to the UPF specifically, as shown in fig. 4B:

s401 b-S404 b refer to S401 a-S404A of fig. 4A, and the embodiments of the present application are not described herein again.

S405b, the SMF sends the timer to the UPF.

Specifically, the SMF may carry a timer in a Session creation Request (Create Session Request) message and send the timer to the UPF, where the Session creation Request is taken as an example in fig. 4B.

In a possible implementation manner, the SMF may further send the obtained indication information indicating that the operation of the PDU session is invalid to the UPF, so that when the UPF monitors that there is no data transmission on the PDU session, the UPF may trigger sending a message indicating whether to convert the PDU session state into an idle state or delete the PDU session to the SMF. Specifically, the SMF may carry the indication message in a PDU Session Accept message and send the PDU Session Accept message to the AN. The indication information may be used to indicate to convert the status of the PDU Session into an idle state (SM handling for Session idle) or to indicate to delete the PDU Session (delete Session).

In addition, when the SMF does not send the indication information to the AN, when receiving a message which is sent by the UPF and detects that no data is transmitted on the PDU session and lasts until the timer times out and invalidates the operation of the PDU session, the SMF determines to execute to convert the PDU session state into AN idle state or to execute to delete the PDU session according to the indication information acquired from the PCF.

The following describes a procedure of configuring a timer of a PDU session to a UE by the SMF, as shown in fig. 4C:

s401 c-S404 c refer to S401 a-S404A of fig. 4A, and the embodiments of the present application are not described herein again.

The SMF sends a message for invalidating the operation of the PDU session to the UE through the AN.

Specifically, the method comprises the following steps:

s405c, the SMF sends a Session Create Request (Create Session Request) message or a PDU Session Setup Accept (PDU Session Setup Accept) message to the AN. The session creation request message is illustrated in fig. 4C.

In one possible implementation, the Create Session Request carries a PDU Session timer (Session Inactive timer).

In another possible implementation manner, the Create Session Request carries a timer of the PDU Session and indication information for indicating an operation for invalidating the PDU Session.

S406c, the AN sends the timer to the UE after receiving the Create Session Request message.

And under the condition that the Create Session Request message carries indication information for indicating the operation of invalidating the PDU Session, the AN sends the indication information to the UE.

The AN may carry the timer and the indication information in AN RRC Connection reconfiguration (RRC Connection reconfiguration) message or AN RRC Connection direct transfer message to the UE, where the RRC Connection message is taken as AN example in fig. 4C and the RRC Connection reconfiguration is taken as AN example in fig. 4C.

S407c, the UE sends AN RRC Connection reconfiguration response (RRC Connection reconfiguration response) message to the AN.

S408c, the AN sends a Session Setup Response (Session Setup Response) message to the SMF.

Based on the scheme described in the embodiment corresponding to fig. 4A, the following describes in detail a procedure for triggering invalidation of the PDU session by the AN, as shown in fig. 5A.

S501a, the AN detects no data transmission on a certain PDU session and continues until the timer times out.

When a PDU Session is configured, if the AN receives indication information which is sent by the SMF and used for indicating invalid PDU Session, if the indication information is Session Idle, the PDU Session is determined to be triggered to be executed and converted into AN Idle state, and if the indication information is delete Session, the PDU Session is determined to be triggered to be executed and deleted. Fig. 5A illustrates an example in which the instruction information is Session Idle.

S502a-S503a, the AN sends a first message for indicating a transition of the PDU session into AN idle state to the SMF through the AMF.

The first message may be a PDU Session Inactive Request (PDU _ Session _ Inactive _ Request) message or a Session status transmission Request (Session status transmission Request) message. Taking PDU Session Inactive Request as an example, the PDU Session Inactive Request message may carry the identifier of the PDU Session. The PDU session identifier may be an ID of the PDU session, and of course, other information that can identify the PDU session is applicable to the present application, which is not described herein again. In addition, when the application relates to the identification of the PDU session in the following, the ID of the PDU session is taken as an example for explanation. The PDU Session Inactive Request message may also carry a cause value (cause), where the cause value is used to indicate that a timer of the PDU Session is overtime.

In addition, if the indication information is a delete Session, the first message may be a delete Session request (delete Session request) message, where the delete Session request message may carry an identifier of the PDU Session and may also carry a cause value, and the cause value is used to indicate that a timer of the PDU Session is overtime.

In a possible implementation manner, when a PDU session is configured, if the AN does not receive indication information sent by the SMF and used for indicating AN invalid PDU session, after receiving a first message triggered by the AN, the SMF determines whether to perform a state transition of the PDU session to AN idle state or to perform deletion of the PDU session based on the indication information acquired from the PCF.

S504a, the SMF sends a message to the UPF indicating to delete the information related to the AN corresponding to the PDU session.

The message for indicating to delete the information related to the PDU Session may be a Session-idle transition Request (Session-idle transition Request) message, or a Release Access Bearers Request (Release Access Bearers Request) message. The Session-idle transition Request message carries a PDU Session ID. The Session-idle transition Request message may also carry a cause value, where the cause value indicates that a timer is overtime (Session Inactive timer is overtime). Fig. 5A illustrates a Session-idle transition Request message as an example.

S505a, the UPF deletes the information related to the AN corresponding to the PDU Session ID. Wherein the UPF can also suspend (suspend) NG3 interface information corresponding to the PDU session.

In one possible design, if the first message indicates to delete the PDU session, the SMF sends a message, such as a delete session request message, to the UPF in step S504a, indicating to delete the information related to the PDU session. So that the UPF performs the deletion of the information related to the PDU session.

Optionally, the method further comprises:

s506a, the UPF sends a Session-idle transition Response (Session-idle transition Response) message to the SMF.

S507a, the SMF sends a message to the AMF instructing the AMF to set the PDU session to idle.

The message instructing the AMF to set the PDU Session to idle may be a Session-idle transition Request Response (Session-idle transition Request Response) message. In fig. 5A, a Session-idle transition Request Response message is transmitted in a Session-in-idle state.

Optionally, after receiving the transmission response that the session enters the idle state, the AMF sets the state of the PDU session to the idle state.

S508a, the SMF sets the status of the PDU Session to IDLE (Session-IDLE).

Optionally, the SMF sets the state of the PDU Session to an IDLE-state (Session-IDLE) time, and may also be after receiving the first message.

In addition, the embodiment of the present application does not limit the execution sequence of step S508a and step S507 a.

S509a, the AMF sends a message to the AN instructing the AN to release the context of the PDU session. The message for instructing the base station to Release the Context of the PDU Session may be a Session Context Release Command (Session Context Release Command), which is taken as an example in fig. 5A.

S510a, the AN deletes or suspends the radio resource corresponding to the PDU session.

Specifically, the Radio resource Bearer (DRB) corresponding to the PDU session is suspended or deleted or the Radio resource allocated for transmitting the Data of the PDU session is deleted.

It should be noted that, in the case that multiple PDU sessions multiplex a DRB, the AN may delete the mapping relationship between the data of the PDU session and the DRB, so that a specific DRB is no longer used for transmitting the data of the PDU session in the IDLE state.

Specifically, the AN may delete a mapping relationship between a Quality of Service (QoS) flow (flow) corresponding to the PDU session and the DRB.

Optionally, the AN updates AN Access Stratum (AS) filter (AS-level filter), where the filter is used for the AN to perform mapping from QoS flow to DRB, and specifically, information related to the PDU session in the AS-level filter may be deleted, or information related to the PDU session in the AS-level filter is marked AS inactive (inactive) or idle.

If the UE is in the RRC inactive state, after performing S510a, S514a is performed, otherwise S511a is performed.

S511a, the AN sends a message to the UE instructing the UE to delete or suspend radio resources corresponding to the PDU session.

The message for instructing the UE to delete or suspend the radio resource corresponding to the PDU session may be an RRC Connection Reconfiguration (RRC Connection Reconfiguration) message, which is exemplified in fig. 5A.

The message for instructing the UE to delete or suspend the radio resource corresponding to the PDU session may carry an identifier of a radio resource bearer DRB to be deleted or suspended.

S512a, the UE deletes or suspends the DRB corresponding to the PDU session.

The UE may also set the status of the PDU session to an idle state.

Specifically, the UE may also delete the mapping relationship from the QoS flow of the PDU session to the DRB.

Optionally, before the UE sets the state of the PDU session to an idle state, it is determined that all radio resources corresponding to the PDU session are deleted or suspended.

S513a, the UE sends AN RRC Connection Reconfiguration Complete (RRC Connection Reconfiguration Complete) message to the AN.

S514a, the AN sends a Session Context release Complete message to AMF.

Based on the scheme described in the embodiment corresponding to fig. 4B, the following describes in detail a procedure for invalidating the PDU session triggered by the UPF, which is shown in fig. 5B.

S501b, the UPF detects no data transmission on a certain PDU session and continues until the timer times out.

When the PDU Session is configured, if the UPF receives indication information which is sent by the SMF and used for indicating invalid PDU Session, if the indication information is SM handling for Session Idle, the PDU Session is determined to be triggered to be executed and converted into an Idle state, and if the indication information is delete Session, the PDU Session is determined to be triggered to be executed and deleted. In fig. 5B, the instruction information is SM handling for Session Idle as an example.

S502b, the UPF sends a first message to the SMF indicating to convert the PDU session into an idle state.

The first message may be a PDU Session inactivity Request (PDU Session Inactive Request) message, which is exemplified in fig. 5B. The PDU Session Inactive Request message may carry an identifier of the PDU Session. The PDU session identifier may be an ID of the PDU session, and of course, other information that can identify the PDU session is applicable to the present application, which is not described herein again. The PDU Session Inactive Request message may also carry a cause value (cause), where the cause value is used to indicate that a timer of the PDU Session is overtime.

In addition, if the indication information is a delete Session, the first message may be a delete Session request message.

In a possible implementation manner, when a PDU session is configured, if a UPF does not receive indication information sent by an SMF and used for indicating an invalid PDU session, the SMF determines whether to convert a status of executing the PDU session into an idle status or to execute deletion of the PDU session based on the indication information acquired from a PCF after receiving a first message triggered by the UPF.

S503 b-S504 b, the SMF sends a message for indicating the AN to release the context of the PDU session to the AN through the AMF. The message for instructing the AN to Release the Context of the PDU Session may be a Session Context Release Command (Session Context Release Command) or may be a PDU Session Inactive Request (PDU Session Inactive Request) message. The message for instructing the base station to release the context of the PDU session may carry an identifier of the PDU session (in this application, the ID of the PDU session is taken as an example).

S505b, the AN deletes or suspends the radio resource corresponding to the PDU session.

Specifically, the Radio resource Bearer (DRB) corresponding to the PDU session is suspended or deleted.

When a DRB is multiplexed with a plurality of PDU sessions, the mapping relationship between the data of the PDU sessions and the DRB is deleted.

In addition, the AN can also delete the mapping relation between the QoS flow corresponding to the PDU session and the DRB.

Specifically, the AN updates the AS-level filter, where the filter is used for the AN to perform mapping from the QoS flow to the DRB, and specifically, the information related to the PDU session in the AS-level filter may be deleted, or the information related to the PDU session in the AS-level filter is marked AS inactive (inactive) or idle.

S506b, the AN sends a message to the UE instructing the UE to delete or suspend radio resources corresponding to the PDU session.

The message for instructing the UE to delete or suspend the radio resource corresponding to the PDU session may be an RRC Connection Reconfiguration (RRC Connection Reconfiguration) message.

S507b, the UE deletes or suspends the DRB corresponding to the PDU session.

The UE may also set the status of the PDU session to an idle state.

S508b, the UE sends AN RRC Connection Reconfiguration Complete (RRC Connection Reconfiguration Complete) message to the AN.

S509b, the AN sends a message to the AMF instructing the AMF to set the status of the PDU session to AN idle state.

The message instructing the AMF to set the status of the PDU Session to an idle status may be a PDU Session Inactive response (PDU Session Inactive response) message.

S510b, the AMF sets the status of the PDU session to idle.

S511b, the AMF forwards the received message for instructing the AMF to set the status of the PDU session to an idle state to the SMF.

S512b, the SMF setting the status of the PDU session to idle.

S513b, the SMF sends a message to the UPF indicating to delete the information related to the AN corresponding to the PDU session.

Wherein the message for indicating to delete the information related to the PDU Session may be a PDU Session Inactive response (PDU Session Inactive response) message. The PDU Session Inactive response message carries a PDU Session ID.

S514b, the UPF deletes the information related to the AN corresponding to the PDU session. Wherein the UPF can also delete NG3 interface information corresponding to the PDU session.

Through the scheme, the timer of the PDU session is configured in the UPF, so that the complexity of the AN for monitoring the timer based on the PDU session can be reduced. In this scheme, the AN may configure a timer for each UE separately, and the timer of the UE and the timer of the PDU session are independent from each other.

Based on the scheme described in the embodiment corresponding to fig. 4C, the following describes in detail a procedure for triggering the invalidation of the PDU session by the UE, which is shown in fig. 5C.

S501c, the UE detects no data transmission on a certain PDU session and continues until the timer times out.

When a PDU Session is configured, if UE receives indication information which is sent by SMF and used for indicating invalid PDU Session, if the indication information is SM handling for Session Idle, the PDU Session is determined to be triggered to be executed and converted into an Idle state, and if the indication information is delete Session, the PDU Session is determined to be triggered to be executed and deleted. In fig. 5C, the instruction information is SM handling for Session Idle.

S502c-S503c, the UE transmits a first message for instructing transition of the PDU session into AN idle state to the SMF through the AN.

Wherein the first message may be a PDU Session Inactive Request (PDU Session Inactive Request) message. The PDU Session Inactive Request message may carry an ID of the PDU Session. The PDU Session Inactive Request message may also carry a cause value (cause), where the cause value is used to indicate that a timer of the PDU Session is overtime.

In a possible implementation manner, when a PDU session is configured, if the UE does not receive indication information sent by the SMF and used for indicating an invalid PDU session, after receiving a first message triggered by the UE, the SMF determines whether to perform a state transition of the PDU session to an idle state or to perform a deletion of the PDU session based on the indication information acquired from the PCF.

S504c, the SMF sends a message to the UPF indicating to delete the information related to the AN corresponding to the PDU session.

The message for indicating to delete the information related to the PDU Session may be a PDU Session Inactive Request (PDU Session Inactive Request) message, and the PDU Session Inactive Request is taken as an example in fig. 5C. The PDU Session Inactive Request message carries a PDU Session ID. The PDU Session Inactive Request message may also carry a cause value, where the cause value indicates that the timer is overtime (Session Inactive timer is overtime).

S505c, the UPF deletes the information related to the AN corresponding to the PDU session. Wherein the UPF can also delete NG3 interface information corresponding to the PDU session.

Optionally, the method further comprises:

s506c, the UPF sends a PDU Session Inactive Request Response (PDU Session Inactive Request Response) message to the SMF.

S507c, the SMF sends a PDU Session Inactive Request Response (PDU Session Inactive Request Response) message to the AMF.

Optionally, after receiving the PDU session inactivity request response message, the AMF sets the status of the PDU session to an idle state.

S508c, the SMF sets the status of the PDU Session to IDLE (Session-IDLE).

S509c, the AMF sends a message to the AN instructing the AN to release the context of the PDU session. The message for instructing the base station to Release the Context of the PDU Session may be a Session Context Release Command (Session Context Release Command) or a PDU Session inactivity request response message.

S510c, the AN deletes or suspends the radio resource corresponding to the PDU session.

Specifically, the DRB corresponding to the PDU session is suspended (suspend) or deleted.

Specifically, the AN updates the AS-level filter, where the filter is used for the AN to perform mapping from the QoS flow to the DRB, and specifically, information related to the PDU session in the AS-level filter may be deleted, or information related to the PDU session in the AS-level filter is marked AS inactive or idle.

S511c, the AN sends a message to the UE instructing the UE to delete or suspend radio resources corresponding to the PDU session.

S512c, the UE deletes or suspends the DRB corresponding to the PDU session.

The UE may also set the status of the PDU session to an idle state.

S513c, the UE sends AN RRC Connection Reconfiguration Complete (RRC Connection Reconfiguration Complete) message to the AN.

S514c, the AN sends a PDU session context release complete message to the AMF.

When the UE is in the RRC inactive connected state, the state of the PDU session may be idle or active. Therefore, it is required that the UE transits to the idle state after the last active PDU session transits to the idle state at the UE.

When the UE is in the RRC non-activated connection state, the state of the PDU session is set to be the idle state by the AN after the PDU session enters the idle state. So that the UE needs to perform state synchronization of the PDU session with the AN after entering the RRC connected state thereafter.

The following describes the state synchronization process in detail, and refer to fig. 6A, which is a schematic diagram of a corresponding state synchronization procedure when the UE is in an RRC inactive connection state.

S601a, the UE determines that it is in an RRC inactive connection state.

S602a, when uplink data arrives or a paging request is received, the UE sends a request message to the AN for instructing to resume the RRC connection of the UE.

The Request message for indicating to Resume the RRC Connection of the UE may be an RRC Connection Resume Request (RRC Connection Resume Request) message. The request message for indicating to recover the RRC connection of the UE carries parameters, where the parameters may include an identifier of a PDU session or an identifier of a DRB corresponding to the PDU session. The parameter may further include first status information of a QoS flow corresponding to a PDU session, where the first status information indicates that a status of the QoS flow on the UE is AN active status or AN inactive status, and is used for the AN and the UE to synchronize the status of the QoS flow.

It should be noted that the PDU session corresponding to the identification of the PDU session may be a PDU session with a data transmission requirement, or a PDU session to be activated.

Optionally, the request message for indicating to restore the RRC connection of the UE may also carry Status information (Established PDU Session Status) of a PDU Session required for data transmission, where the Status information is used to indicate that a PDU Session Established by the AN is in AN active state or in AN idle state on the UE.

S603a, the AN determines the PDU session to be activated according to the parameter carried in the request message for indicating to recover the RRC connection of the UE.

Wherein, the state of the PDU conversation to be activated is an idle state.

S604a, the AN triggers the process of activating the PDU session.

It should be noted that the PDU session is activated, that is, the user plane connection between the UE and the UPF corresponding to the PDU session is established.

Specifically, the AN triggers the process of activating the PDU session, and specifically, the AN may send a message for triggering the conversion of the PDU session into the active state to the SMF.

And after receiving the message for triggering the PDU to be converted into the active state, the SMF executes the process of converting the PDU session into the active state.

S605a, the AN configures the mapping relationship between the QoS flow corresponding to the PDU session and the DRB.

S606a, the AN sends the configured mapping relation to the UE.

Optionally, the AN sends the second state information of the QoS flow corresponding to the PDU session to the terminal, so as to indicate that the terminal and the base station synchronize the state of the QoS. The second status information indicates that the status of the QoS flow corresponding to the PDU session on the AN is AN active status or AN inactive status (idle status).

The sequence between the step S607a and the steps S605a to S606a is not distinguished.

Optionally, the AN may carry the configured mapping relationship in AN RRC connection recovery response message and send the RRC connection recovery response message to the UE, where the RRC connection recovery response message is taken as AN example in fig. 6A. The AN may also carry the second state information of the QoS flow corresponding to the PDU session in AN RRC connection resume response message, and send the RRC connection resume response message to the UE.

S607a, the UE synchronizes the state of the QoS flow corresponding to the PDU session with the AN based on the second state information, and the UE saves the mapping relation.

As described with reference to fig. 6B, the UE is in a Connection Management (CM) idle state.

S601b, the UE sends a request message to the SMF through the AMF.

The Request message may also be a Service Request (Service Request) message or an Active Session Request (Active Session Request) message, and fig. 6B illustrates the Active Session Request message as an example. The Active Session Request message carries parameters, and the parameters may include an identifier of a PDU Session or an identifier of a DRB corresponding to the PDU Session. The parameters may further include status information of a QoS flow corresponding to a PDU session, where the status information indicates that the status of the QoS flow on the UE is an active status or an inactive status, and is used for the SMF and the UE to synchronize the status of the QoS flow.

Optionally, the Active Session Request message may also carry Status information (updated PDU Session Status) of the PDU Session required for data transmission, where the Status information is used to indicate that the Status of the PDU Session Established by the SMF on the UE is an Active Status or an idle Status. Thereby for state synchronization of the PDU session between the UE and the SMF.

S602b, after receiving the request message sent by the UE, the SMF completes activating the QoS flow in the PDU session with the UPF.

S603b, the SMF determines the status of the QoS flow in the PDU session after completion of the activation.

And after determining that the activated state of the QoS flow in the PDU session is completed, the SMF sends the state information of the QoS flow in the PDU session to the UE. The state information of the QoS flow in the PDU session indicates that the state of the QoS flow corresponding to the PDU session on the SMF is an active state or an inactive state.

Specifically, the SMF sends the state information of the QoS flow in the PDU session to the UE through the AMF and the AN.

Alternatively, S604b, the SMF may send the state information of the QoS flow in the PDU Session to the AMF first through an Active Session request response (Active Session response) message.

S605b, the AMF carries the status information of the QoS flow in the PDU Session in a Session Context Update (Session Context Update) message, or in AN Active Session response (Active Session response) message, and sends the status information to the AN.

In addition, after the AN receives the state information of the QoS flow in the PDU session sent by the SMF, the AN and the SMF may synchronize the state of the QoS flow in the PDU session and forward the state to the UE.

S606b, the AN may send the status information of the QoS flow in the PDU session to the UE in AN RRC Reconfiguration (RRC Reconfiguration) message.

S607b, the UE synchronizes the state of the QoS flow corresponding to the PDU session with the SMF based on the state information sent by the SMF.

Optionally, the method may further include:

s608b, the UE sends AN RRC Reconfiguration response (RRC Reconfiguration response) message to the AN.

S609b, the AN sends a Session context update response (Session context update response) message to the AMF.

S610b, the AMF sends a Session context update response (Session context update response) message to the SMF.

S611b, a User Plane (Update Session User Plane) for executing an Update Session is performed between the SMF and the UPF.

S612b, the SMF sends an Update Session response (Update Session response) message to the AMF.

The following describes a cell handover method flow when different states exist for different PDU sessions, and refer to fig. 7, which is a schematic diagram illustrating a cell handover flow. In fig. 7S-AN denotes the source AN and T-AN denotes the target AN.

S701, the UE sends a measurement report to the S-AN. The measurement report includes the measurement result of the serving cell and the measurement result of the neighboring cell.

S702, the S-AN determines to execute cell Handover (HO for short) based on the measurement report sent by the UE.

S703, the S-AN sends a handover request message (HO Required) to the AMF.

And the switching request message carries the identification of the PDU session on the UE. And the state of the PDU session corresponding to the identification of the PDU session is an activated state. And the PDU session corresponding to the PDU session identifier is the PDU session corresponding to the UE and having the PDU session context stored in the S-AN.

S704, the AMF determines the PDU session needing to update the user plane context based on the identification of the PDU session.

S705, the AMF sends a message for informing the SMF to update the user plane context of the PDU session to the SMF.

The message for notifying the SMF to update the user plane context of the PDU session may be a handover Request (HO Request) message, and fig. 7 illustrates a handover Request as an example. Wherein, the HO Request message sent to SMF carries the Identification (ID) of PDU conversation.

S706, the SMF sends AN HO Request message to the T-AN through the AMF. The HO Request message sent to the T-AN may carry the related information of the PDU session (PDU session Info). The method specifically includes QoS information corresponding to PDU session, NG3 tunnel information, QoS flow ID and the like.

S707, the T-AN sends a switching Request receipt (HO Request acknowledgement) to the AMF.

The AMF transmits a handover command (HO command) to the UE through the S-AN S708.

S709, the UE sends a switching confirmation (HO Confirm) to the T-AN after completing the switching.

S710, the T-AN sends a switching notice (HO notify) to the SMF through the AMF.

S711, the SMF sends a Modify Session request (Modify Session request) message to the UPF, where the Modify Session request message is used to instruct the UPF to Modify the related information of the PDU Session.

S712, the UPF sends a Modify Session request response (Modify Session request response) message to the SMF.

The purpose of the message involved in steps S707 to S712 is the same as that of the message in the prior art, and is not described herein again.

Based on the scheme described in the embodiment corresponding to fig. 4A, the following describes in detail a procedure for triggering invalidation of the PDU session by the AN in the handover process, which is shown in fig. 13. In FIG. 13, S-AN represents the source AN currently accessed by the terminal, and T-AN represents the target AN to which the UE is to be handed in.

S801, when the PDU session of the terminal is established or activated, the S-AN configures the timer of the PDU session.

Specifically, if the S-AN currently accessed by the UE receives the PDU session timer sent by the SMF, the S-AN configures the PDU session timer.

S802, after the S-AN receives the timer of the PDU session sent by SMF, if the S-AN detects that no data transmission continues on the PDU session until the timer is overtime, the state of the PDU session is recorded as AN inactive state.

For example, the PDU Session is recorded as an inactive PDU Session, or the PDU Session ID is marked, or the PDU Session ID used to characterize the PDU Session as an inactive state is updated.

S803, when the S-AN determines to execute switching from the S-AN to the T-AN aiming at the UE, determining a first type of PDU session included in the activated PDU session of the UE, wherein the first type of PDU session is AN inactive PDU session (inactive PDU session), and executing a switching process aiming at a second type of PDU session, and the second type of PDU session is a PDU session (active PDU session) except the first type of session in the PDU session of the terminal.

Specifically, the S-AN receives a measurement report (measurement report) sent by the UE, and the S-AN determines whether to perform switching from the S-AN to the T-AN for the UE according to the measurement report. And if the switching from the S-AN to the T-AN is determined to be performed aiming at the UE, determining the PDU session recorded in the inactive state in all the activated PDU sessions of the current terminal, thereby not performing the switching process aiming at the first class of PDU session and only performing the switching process aiming at the second class of PDU session.

In a possible implementation manner, the S-AN performing a handover procedure for the second type PDU session includes: and the S-AN sends a handover request (handover request) to the T-AN.

Wherein, the handover request may only carry the identifier of the second type PDU session, but not the identifier of the first type PDU session. Or, the handover request may carry an identifier of the first type PDU session and an identifier of the second type PDU session. For example, the ID of the first type PDU session is configured in the array 1, and the ID of the second type PDU session is configured in the array 2. Or, the handover request may also carry identifiers of all activated PDU sessions of the terminal and a first indication, where the first indication is used to mark a first type of PDU session in the activated PDU sessions of the terminal. For example, all the enabled PDU session IDs of the terminal are placed in an array, and different flags are used for the first type PDU session and the second type PDU session, for example, the first type PDU session flag is 0 and the second type PDU session flag is 1.

It should be noted that the Identification (ID) of the activated PDU session of the UE, the first-class PDU session ID, or the second-class PDU session ID may be carried in the context (active PDU session info) of the activated PDU session, and may also be carried outside the active PDU session info.

For example, the AS layer content (AS content) may be carried in the handover request. The AS content may include therein the context of all the activated PDU sessions of the terminal. The context of all the activated PDU sessions of the terminal comprises the ID of the activated PDU session of the terminal, and the ID of the first type of PDU session is also carried outside the context of all the activated PDU sessions of the terminal and in the switching request, or the ID of all the activated PDU sessions and the first indication are also carried outside the context of all the activated PDU sessions of the terminal and in the switching request. Or, the AS content in the handover request may only include a context (active PDU session info) of the second type PDU session, and the id (active PDU session ids) of the first type PDU session is carried in the handover request besides the active PDU session info. Or, the switching request only carries active PDU session info.

In another possible implementation manner, the S-AN performing a handover procedure for the second type PDU session includes: and the S-AN sends a handover request (handed required) to the AMF. Wherein, the handover request may only carry the identifier of the second type PDU session, but not the identifier of the first type PDU session. Or, the handover request may carry an identifier of the first type PDU session and an identifier of the second type PDU session. For example, the ID of the first type PDU session is configured in the array 1, and the ID of the second type PDU session is configured in the array 2. Or, the handover request may also carry identifiers of all activated PDU sessions of the terminal and a first indication, where the first indication is used to mark a first type of PDU session in the activated PDU sessions of the terminal. For example, all the enabled PDU session IDs of the terminal are placed in an array, and different flags are used for the first type PDU session and the second type PDU session, for example, the first type PDU session flag is 0 and the second type PDU session flag is 1.

For example, a transparent container (source to target transit container) may be carried in the handover request. The source to target parent container may include therein the context of all the activated PDU sessions of the terminal. The context of all the activated PDU sessions of the terminal comprises the ID of the activated PDU session of the terminal, and the ID of the first type of PDU session is also carried outside the context of all the activated PDU sessions of the terminal and in the switching request, or the ID of all the activated PDU sessions and the first indication are also carried outside the context of all the activated PDU sessions of the terminal and in the switching request. Or, the AS content in the handover request may only include a context (active PDU session info) of the second type PDU session, and the id (active PDU session ids) of the first type PDU session is carried in the handover request except for the active PDU session info, or the handover request only carries the active PDU session info.

Next, on the basis of fig. 13, a flow of triggering and invalidating the PDU session by the AN in the handover process is described in detail below, and refer to fig. 14A to 14C.

Referring to fig. 14A, AN interface handover based on Xn (interface between AN and AN) is shown. Take AS an example that the AS content in the handover request includes a context (active PDU session info) of the second type PDU session, and the switching request carries an id (active PDU session ids) of the first type PDU session in addition to the active PDU session info.

S901a, when the PDU session of the terminal is established or activated, the S-AN configures a timer for the PDU session.

S902a, after the S-AN receives the timer of the PDU session sent by SMF, if the S-AN detects that no data transmission continues on the PDU session until the timer times out, recording the status of the PDU session as AN inactive status.

S903a, the UE sends a measurement report (measurement report) to the S-AN.

S904a, the S-AN receives a measurement report (measurement report) sent by the UE, and the S-AN determines whether to switch from the S-AN to the T-AN aiming at the UE according to the measurement report.

When the S-AN determines to execute switching from the S-AN to the T-AN aiming at the UE, determining a first class of PDU session included in the activated PDU session of the UE, wherein the first class of PDU session is recorded as AN inactive state PDU session, and executing a switching process aiming at a second class of PDU session, and the second class of PDU session is a PDU session of the terminal except the first class of session.

Specifically, the S-AN performing a handover procedure for the second type PDU session includes:

s905a, the S-AN sends a handover request to the T-AN.

S906a, the T-AN sends a handover request acknowledgement (handover request ACK) to the S-AN. The handover request reply may include the context of the second type PDU session parsed from As content by T-AN and the id (inactive PDU session ids) of the first type PDU session.

S907a, the S-AN sends a message to the UE instructing the terminal to perform AN operation of invalidating the first type PDU session.

Wherein, the message for instructing the terminal to execute the operation of invalidating the first type PDU session carries: an identification of the first type PDU session; or, the message for instructing the terminal to execute the operation of invalidating the first-class PDU session carries: the terminal comprises an identification of the terminal's active PDU sessions and a first indication, wherein the first indication is used for identifying the first class of PDU sessions in the terminal's active PDU sessions.

The message for instructing the terminal to perform the operation of invalidating the PDU session of the first type may be an RRC reconfiguration (RRC reconfiguration) message, which is taken as an example in fig. 14A. And carrying the ID of the first type PDU conversation in an RRC reconfiguration (RRC reconfiguration) message. Fig. 14A illustrates an operation of invalidating the first type PDU session as an example of converting the state of the first type PDU session from the active state to the idle state.

S908a, the UE sends AN RRC reconfiguration complete (RRC reconfiguration complete) message to the S-AN.

S909a, the UE updates the state corresponding to the first PDU session (inactive PDU session) in the RRC reconfiguration message to an IDLE state (session-IDLE).

S910a-S916a are procedures for performing core network path switching for the second type PDU session.

S910a, the T-AN sends AN N2 path switch (N2 path switch) message to the AMF, and the N2 path switch carries the context of the second type PDU session. The N2 path switch may also carry an identification of the first type of PDU session. N2 is the interface between the base station and the AMF. The N2 path switch is used to instruct AMF to switch the path from S-AN to T-AN, and update the context of the second type PDU session.

S911a, AMF sends N11 message (N11 message) to SMF, N11 message carries the context of the second type PDU conversation. N11 is the interface between SMF and AMF. And the N11 message is used for indicating the SMF to update the context of the second PDU session.

S912a, the SMF sends N4session modification (N4session modification) to the UPF, and N4session modification carries the context of the second type PDU session. N4 is the interface between SMF and UPF.

S913a, the UPF sends an N4session modification receipt (ACK) to the SMF.

S914a, the SMF sends an N11 session modify ACK to the AMF.

S915a, the AMF sends AN N2 path switch ACK to the T-AN.

S916a, the T-AN sends a UE context release message (UE content release) to the S-AN.

S917a, in S910, after receiving the N2 path switch (N2 path switch) sent by the S-AN, if the N2 path switch does not carry the identifier of the first type PDU session, the AMF determines the first type PDU session based on the identifier of the second type PDU session. And storing the identifications of all the activated PDU sessions of the terminal in the AMF, so that the AMF determines the PDU sessions except the second type PDU session corresponding to the identification in the stored activated PDU sessions of the terminal.

S918a, the AMF sends a message to the SMF instructing the SMF to perform an operation of invalidating the first type PDU session. The message for the SMF to indicate to perform the operation of invalidating the first type PDU session may be N11 message.

If the AMF receives the N2 path switch (N2 path switch) sent by the S-AN in S910a, and carries the identifier of the first-type PDU session in the N2 path switch, S918a may be directly executed.

S919a, the SMF sends a message to the UPF instructing the UPF to perform an operation of invalidating the first-type PDU session. The message for the SMF to indicate to perform the operation of invalidating the first type PDU session may be a session-IDLE transition (N4 session-IDLE transition).

S920a, the UPF converts the status of the first type PDU session into an idle status. Fig. 14A illustrates an example of a state transition from the first-type PDU session to the idle state by invalidating the first-type PDU session.

S921a, the UPF sending a message to the SMF, the message indicating that the operation of invalidating the first-type PDU session is completed. The message for indicating that the execution of the operation of invalidating the first-type PDU session is completed may be an N4session transition-IDLE transition complete message (N4 session-IDLE transition complete).

S922a, the SMF performs a state transition of the first type PDU session to an idle state.

S923a, the SMF sends a message to the AMF indicating to perform an operation of invalidating the first-type PDU session. The message for instructing to perform the operation of invalidating the first-type PDU session may be through an N11 message ACK.

S924a, the AMF performs a transition of the status of the first type PDU session to an idle status.

Referring to fig. 14B, AN interface handover based on Xn (interface between AN and AN) is shown. Take AS an example that the AS content in the handover request includes a context (active PDU session info) of the second type PDU session, and the handover request does not carry an id (active PDU session ids) of the first type PDU session.

S901b, when the PDU session of the terminal is established or activated, the S-AN configures a timer for the PDU session.

S902b, after the S-AN receives the timer of the PDU session sent by SMF, if the S-AN detects that no data transmission continues on the PDU session until the timer times out, recording the status of the PDU session as AN inactive status.

S903b, the UE sends a measurement report (measurement report) to the S-AN.

S904b, the S-AN receives a measurement report (measurement report) sent by the UE, and the S-AN determines whether to switch from the S-AN to the T-AN aiming at the UE according to the measurement report.

s905b, the S-AN sends a handover request to the T-AN.

S906b, the T-AN sends a handover request acknowledgement (handover request ACK) to the S-AN. The handover request back-to-back may include the context of the second type PDU session parsed from Ascontent by the T-AN.

S907b, the S-AN sends RRC reconfiguration (RRC reconfiguration) message to the UE.

S908b, the UE sends AN RRC reconfiguration complete (RRC reconfiguration complete) message to the S-AN.

S909b-S915b are procedures for performing core network path switching for the second type PDU session.

S909b, the T-AN sends AN N2 path switch (N2 path switch) message to the AMF, and the N2 path switch carries the context of the PDU session of the second type. N2 is the interface between the base station and the AMF. The N2 path switch is used to instruct AMF to switch the path from S-AN to T-AN, and update the context of the second type PDU session.

S910b, AMF sends N11 message (N11 message) to SMF, N11 message carries the context of the second type PDU conversation. N11 is the interface between SMF and AMF. And the N11 message is used for indicating the SMF to update the context of the second PDU session.

S911b, the SMF sends N4session modification (N11 session modification) to the UPF, and the N11 path switch carries the context of the second type PDU session. N11 is the interface between SMF and AMF.

S912b, the UPF sends an N11 session modify Acknowledgement (ACK) to the SMF.

S913b, the SMF sends an N11 session modify ACK to the AMF.

S914b, AMF sends N2 path switch ACK to T-AN.

S915b, the T-AN sends a UE context release message (UE content release) to the S-AN.

S916b, after the AMF receives the N2 path switch (N2 path switch) sent by the S-AN in S909b, the AMF determines the first type PDU session based on the identity of the second type PDU session. And storing the identifications of all the activated PDU sessions of the terminal in the AMF, so that the AMF determines the PDU sessions except the second type PDU session corresponding to the identification in the stored activated PDU sessions of the terminal.

S917b, the AMF sends a message to the SMF instructing the SMF to perform an operation of invalidating the PDU session of the first type. The message for the SMF to indicate to perform the operation of invalidating the first type PDU session may be through N11 message.

S918b, the SMF sends a message to the UPF instructing the UPF to perform an operation of invalidating the first-type PDU session. The message for instructing the UPF to perform the operation of invalidating the first-type PDU session may be N4 session-IDLE transition.

S919b, the UPF converts the status of the first type PDU session to an idle state. Fig. 14B illustrates an example of a state transition from the first-type PDU session to the idle state by invalidating the first-type PDU session.

S920ba, the UPF sends a message to the SMF to indicate to perform an operation of invalidating the first type PDU session.

S921b, the SMF performs converting the status of the first type PDU session into an idle state.

S922b, the SMF sends a message to the AMF indicating that the operation of invalidating the PDU session of the first type is completed. The message for instructing to perform the operation of invalidating the first-type PDU session may be through an N11 message ACK.

S923b, the AMF performs a state transition of the first type PDU session to an idle state.

S924b, the AMF sends a message to the UE for instructing the UE to perform an operation of invalidating the first type PDU session. The message for instructing the UE to perform the operation of invalidating the first-type PDU session may be an N1 session-IDLE transition request. The N1 session-IDLE transition request carries the identifier of the first type PDU session, or carries the identifier of the activated PDU session of the terminal and the first indication. N1 is the interface between the AMF and the UE.

S925b, the UE updates the status of the PDU session of the first type to idle.

S926b, the UE sends a message to the AMF indicating to perform an operation of invalidating the first type PDU session. The message for indicating that the operation of invalidating the first-type PDU session is performed may be an N1 session-IDLE transition response.

Referring to fig. 14C, interface switching based on X1 (interface between AN and core network) is shown. The transparent container (source to target destination container) in the handover request includes a context (active PDU session info) of the second type PDU session, and the switching request carries an id (active PDU session ids) of the first type PDU session.

S901c, when the PDU session of the terminal is established or activated, the S-AN configures a timer for the PDU session.

S902c, after the S-AN receives the timer of the PDU session sent by SMF, if the S-AN detects that no data transmission continues on the PDU session until the timer times out, recording the status of the PDU session as AN inactive status.

S903c, the UE sends a measurement report (measurement report) to the S-AN.

S904c, the S-AN receives a measurement report (measurement report) sent by the UE, and the S-AN determines whether to switch from the S-AN to the T-AN aiming at the UE according to the measurement report.

s905c, the S-AN sends a handover request (handed required) to the AMF.

The transparent container (source to target transparent container) in the driver required includes a context (active PDU session info) of the second type PDU session, and the id (active PDU session ids) of the second type PDU session is carried in the handover request besides the active PDU session info.

The handover request (handover required) is used to indicate that no handover operation is performed for other PDU sessions outside the second type of PDU session (i.e. the first type of PDU session), i.e. an operation to invalidate other PDU sessions outside the second type of PDU session is performed. And the first-class PDU session is invalidated to update the state of the first-class PDU session into an idle state or delete the first-class PDU session.

S906c, the AMF sends an N11 handover request (N2 handover required) message to the SMF.

S907c, the SMF sends N11 handover request (N11 handover request) to the AMF, N11 handover request carries the context of all activated PDU sessions (PDU session info) of the terminal.

S908c, AMF sends switch request (handover request) to T-AN, the handover request carries transparent container (source to target transparent container).

S909c, T-AN sends a handover request acknowledgement (Handover request ACK) to AMF. The handover request ACK carries a transparent container (source to target parent container).

S910c, the AMF sends a handover request acknowledgement (handover request ACK) to the SMF, where the handover request ACK carries a context of the PDU session.

S911c, the SMF sends an N11 switch command (N11 handover command) to the AMF.

S912c, the AMF sends a handover command (handover command) to the UE through the S-AN.

S913c, the UE sends a handover confirm (handover confirm) to the T-AN.

S914c, the T-AN sends a handover notification (handover notify) to the AMF. The handover notification (handover notification) is used to instruct the AMF to transfer the PDU session of the terminal from the S-AN to the T-AN.

S915c, the AMF determining the first type PDU session based on the identification of the second type PDU session. And storing the identifications of all the activated PDU sessions of the terminal in the AMF, so that the AMF determines the PDU sessions except the second type PDU session corresponding to the identification in the stored activated PDU sessions of the terminal.

Specifically, in step S905c, the handover request (handover required) sent by the S-AN to the AMF carries the identifier of the second type PDU session.

Optionally, the AMF determines a first type PDU session based on the identifier of the second type PDU session, and then the AMF performs to update the state of the first type PDU session to an idle state or delete the first type PDU session.

S916c, the AMF sends a handover notification (handover notify) to the SMF. And the switching notice (handover notification) carries the identification of the first type PDU session, and is used for indicating the AMF to convert the PDU session of the terminal from S-AN to T-AN.

S917c, a PDU session modification (modify session) is performed between the SMF and the UPF.

S918c, after determining the first type PDU session based on the identifier of the second type PDU session, the AMF sends a message to the SMF, where the message is used to instruct the SMF to perform an operation of invalidating the first type PDU session. The message instructing the SMF to perform an operation of invalidating the first type PDU session may be an N11 message. The message for instructing the SMF to execute the operation of invalidating the first type PDU session may carry an identifier of the first type PDU session.

S920c, the SMF sending a message to the UPF instructing the UPF to perform an operation of invalidating the PDU sessions of the first type. The message for instructing the UPF to perform the operation of invalidating the first-type PDU session may be N4 session-IDLE transition.

S920c, the UPF converts the status of the first type PDU session into an idle status.

S921c, the UPF sending a message to the SMF, the message indicating that the operation of invalidating the first-type PDU session is completed.

S922c, the SMF performs a state transition of the first type PDU session to an idle state.

S923c, the SMF sends a message to the AMF indicating to perform an operation of invalidating the first-type PDU session. The message for instructing to perform the operation of invalidating the first-type PDU session may be through an N11 message ACK.

S924c, the AMF performs a transition of the status of the first type PDU session to an idle status.

S925c, the AMF sends a message to the UE instructing the UE to perform an operation of invalidating the PDU session of the first type. The message for instructing the UE to perform the operation of invalidating the first-type PDU session may be an N1 session-IDLE transition request. N1 is the interface between the AMF and the UE.

S926c, the UE updates the status of the first type PDU session to an idle state.

S927c, the UE sends a message to the AMF, the message indicating that the operation of invalidating the first-class PDU session is performed. The message for indicating that the operation of invalidating the first-type PDU session is performed may be an N1 session-IDLE transition response.

Based on the same inventive concept as the method embodiment, the embodiment of the present application further provides a session management device, and because the principles of the method and the device for solving the problem are similar, the implementation of the device and the method can be mutually referred, and repeated parts are not described again.

An embodiment of the present application provides a session management apparatus, where the apparatus is applied to a first core network device, including as shown in fig. 8A.

A receiving module 801a, configured to receive a request message for activating a packet data unit PDU session;

a sending module 802a, configured to send the timer of the PDU session to a second device;

the receiving module 801a is further configured to receive a first message, initiated by the second device, for invalidating the operation of the PDU session; the first message is issued by the second device detecting no data transmission on the PDU session and persisting until the timer times out.

In one possible design, the second device is a second core network device, or a base station, or a terminal.

In one possible design, further comprising:

a first determining module 803a, configured to determine the timer of the PDU session based on slice information of a network slice to which the PDU session belongs, before the sending module 802a sends the timer to the second device.

In a possible design, the receiving module 801a is further configured to receive a timer of the PDU session sent by a third core network device.

In a possible design, the sending module 802a is further configured to send, to the second device, indication information, where the indication information is information used to indicate that the operation of the PDU session is not valid.

In a possible design, the receiving module 801a is further configured to receive, after receiving the request message, indication information sent by a third core network device, where the indication information is information used to indicate that the operation of the PDU session is invalidated.

In one possible design, the second determining module 804a is configured to determine, based on the indication information, that the PDU session is to be deactivated to convert the PDU session from the active state to the idle state or to delete the PDU session after the receiving module 801a receives the first message.

In a possible design, the operation of invalidating the PDU session is to convert the PDU session from an active state to an idle state, and the receiving module 801a is further configured to send, after receiving the first message, a message for instructing to delete the information related to the base station corresponding to the PDU session to the second core network device.

the processing module 805a is configured to set the status of the PDU session to an idle state after the receiving module 801a receives the first message.

In a possible design, the operation of invalidating the PDU session is to delete the PDU session, and the sending module is further configured to send, after the receiving module 801a receives the first message, a message for instructing to delete the information related to the PDU session to the second core network device.

In a possible design, the sending module 802a is further configured to send, to the base station, a message for instructing the base station to release the context of the PDU session after the receiving module 801a receives the first message.

In a possible design, the sending module 802a is further configured to send, after the receiving module 801a receives the first message, a message for instructing a fourth core network device to set the status of the PDU session to an idle status.

In a possible design, the receiving module 801a is further configured to receive a second message sent by a fourth core network device, where the second message carries an identifier of a PDU session of a user plane context to be updated;

the device further comprises:

an updating module 806a, configured to update the user plane context of the PDU session corresponding to the identifier of the PDU session.

The division of the modules in the embodiments of the present application is schematic, and only one logical function division is provided, and in actual implementation, there may be another division manner, and in addition, each functional module in each embodiment of the present application may be integrated in one processor, may also exist alone physically, or may also be integrated in one module by two or more modules. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode.

An embodiment of the present application provides a session management apparatus, where the apparatus is applied to a first core network device, as shown in fig. 8B, and includes:

a receiving module 801b, configured to receive a service request message sent by a terminal, where the service request message carries an identifier of a PDU session to be activated;

a processing module 802b, configured to execute a procedure of activating the PDU session based on the service request message.

In one possible design, the apparatus further includes:

a sending module 803b, configured to send third state information of the QoS flow corresponding to the PDU session to the terminal, so as to indicate that the terminal and the first core network device synchronize the state of the QoS flow corresponding to the PDU session; the third status information indicates that the status of the QoS flow corresponding to the PDU session on the first core network device is an active status or an inactive status.

As shown in fig. 8C, the first core network device may include a processor 820. The hardware of the entity corresponding to the module shown in fig. 8A or 8B may be the processor 820. The processor 820 may be a Central Processing Unit (CPU), a digital processing module, or the like. The first core network device may also include a communication interface 810, and the processor 820 receives data or messages through the communication interface 810. The device also includes: a memory 830 for storing programs executed by the processor 820. The memory 830 may be a nonvolatile memory such as a hard disk (HDD) or a solid-state drive (SSD), and may also be a volatile memory such as a random-access memory (RAM). The memory 830 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such.

The processor 820 is configured to execute the program codes stored in the memory 830, and in particular, is configured to execute the method executed by the first core network device in the embodiments shown in fig. 3 to 7, 13, and 14A to 14C. Reference may be made to the methods described in the embodiments shown in fig. 3 to 7, 13, and 14A to 14C, which are not described herein again.

The specific connection medium among the communication interface 810, the processor 820 and the memory 830 is not limited in the embodiments of the present application. In fig. 8C, the memory 830, the processor 820 and the communication interface 810 are connected by a bus 840, the bus is represented by a thick line in fig. 8C, and the connection manner among other components is only schematically illustrated and is not limited. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, fig. 8C is shown with only one thick line, but does not show only one bus or one type of bus.

An embodiment of the present application provides a session management apparatus, where the apparatus is applied to a base station, as shown in fig. 9A, and includes:

a receiving module 901a, configured to receive a timer of a packet data unit PDU session sent by a first core network device when the PDU session is activated;

a processing module 902a, configured to detect that there is no data transmission on the PDU session and continue until the timer expires;

the sending module 903a is configured to send, to the first core network device, a first message for invalidating the operation of the PDU session.

In a possible design, the receiving module 901a is further configured to receive, when a PDU session is activated, indication information sent by the first core network device, where the indication information is information used to indicate that the operation of the PDU session is disabled.

In a possible design, the receiving module 901a is further configured to receive a message sent by the first core network device and used to instruct the base station to release the context of the PDU;

the processing module 902a is further configured to delete or suspend the radio resource corresponding to the PDU session.

In one possible design, the processing module 902a is further configured to:

and setting the saved state of the PDU conversation to be an idle state.

In a possible design, the processing module 902a is further configured to delete the mapping relationship between the QoS flow corresponding to the PDU session and the DRB after monitoring that there is no data transmission in the PDU session and continuing until the timer expires.

In a possible design, the sending module 903a is further configured to send, to the terminal, a message for instructing the terminal to delete or suspend radio resources corresponding to the PDU session after the processing module 902a monitors that there is no data transmission on the PDU session and the timer expires.

An embodiment of the present application further provides a session management apparatus, where the apparatus is applied to a base station, as shown in fig. 9B, and includes:

a receiving module 901b, configured to receive an RRC connection recovery message sent by the terminal, where the RRC connection recovery message carries parameters;

a processing module 902b, configured to determine, according to the parameter, a PDU session to be activated; and triggering the flow of activating the PDU session.

In one possible design, the apparatus further includes:

a sending module 903b, configured to send, to the first core network device, a message used for triggering conversion of the PDU session into an active state.

In a possible design, the processing module 902b is further configured to configure a mapping relationship between a QoS flow corresponding to the PDU session and a DRB.

In one possible design, further comprising:

the sending module 903b is further configured to send the mapping relationship to the terminal.

In one possible design, the apparatus further includes:

a sending module 903b, configured to send the second state information of the QoS flow corresponding to the PDU session to a terminal, so as to indicate that the terminal and a base station synchronize the QoS state.

In one possible design, the processing module 902b is further configured to determine to perform cell handover for the terminal;

a sending module 903b, configured to send a handover request message to a fourth core network device, where the handover request message carries an identifier of a PDU session that is corresponding to the terminal and in an active state, or the handover request carries an identifier of a PDU session that is corresponding to the terminal and in which a PDU session context is stored in the base station.

An embodiment of the present application further provides a session management apparatus, where the session management apparatus is applied to a source base station, as shown in fig. 9D, and includes:

a receiving module 901d, configured to receive a timer of a PDU session sent by a first core network device when the PDU session of a terminal is established or activated; if the source base station detects that no data transmission continues on the PDU session until the timer is overtime, recording the state of the PDU session as an inactive state;

a processing module 902d, configured to, when it is determined that handover is performed for the terminal from the source base station to the target base station, determine a first type of PDU session included in an activated PDU session of the terminal, where the first type of PDU session is a PDU session recorded in an inactive state, and perform a handover procedure for a second type of PDU session, where the second type of PDU session is a PDU session of the terminal except for the first type of session.

In one possible implementation manner, the method further includes:

a sending module 903d, configured to send, in the processing module 902d, a handover request to the target base station for a second type PDU session, where the handover request only carries an identifier of the second type PDU session; alternatively, the first and second electrodes may be,

In a possible implementation manner, the sending module 903d is configured to send, to the terminal, a message for instructing the terminal to perform an operation of invalidating the first type PDU session in a process of performing handover for the second type PDU session.

Optionally, the message for instructing the terminal to execute the operation of invalidating the first type PDU session carries: an identification of the first type PDU session; alternatively, the first and second electrodes may be,

Optionally, the operation of invalidating the PDU session of the first type includes: and converting the state of the first type PDU conversation from an active state to an idle state or deleting the first type PDU conversation.

In a possible implementation manner, the sending module 903d in the apparatus is configured to send a handover request to a fourth core network device when the processing module 902d executes a handover procedure for a second type PDU session, where the handover request only carries an identifier of the second type PDU session; alternatively, the first and second electrodes may be,

An embodiment of the present application further provides a session management apparatus, where the apparatus applies a target base station, as shown in fig. 9E, and includes:

a receiving module 901e, configured to receive a handover request sent by a source base station to which a terminal is currently accessed, where the handover request only carries an identifier of the second type PDU session; or, the switching request carries the identifier of the first type PDU session and the identifier of the second type PDU session; or, the handover request carries an identifier of an activated PDU session of the terminal and a first indication, where the first indication is used to mark a first type of PDU session in the identifier of the activated PDU session of the terminal;

a sending module 902e, configured to send, to a fourth core network device, a message used to instruct the fourth core network device to perform an operation of invalidating the first-class PDU session.

Wherein the message for instructing the fourth core network device to execute the operation of invalidating the second-class PDU session carries: identification of the first type PDU session. Wherein the operation of invalidating the first type PDU session comprises: and converting the state of the first type PDU conversation from an active state to an idle state or deleting the first type PDU conversation.

As shown in fig. 9C, a base station (which may be a source base station or may be a target base station) may include a processor 920. The hardware of the entity corresponding to the module shown in fig. 9A or 9B or 9D or 9E may be the processor 920. The processor 920 may be a Central Processing Unit (CPU), a digital processing module, or the like. The base station may further comprise a transceiver 910, and the processor 920 receives data, messages through the transceiver 910. The device also includes: a memory 930 for storing programs executed by the processor 920. The memory 930 may be a non-volatile memory, such as a hard disk (HDD) or a solid-state drive (SSD), and may also be a volatile memory, such as a random-access memory (RAM). The memory 930 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such.

The processor 920 is configured to execute the program codes stored in the memory 930, and in particular, is configured to execute the method performed by the base station in the embodiments shown in fig. 3 to 7, 13, and 14A to 14C. Reference may be made to the methods described in the embodiments shown in fig. 3 to 7, 13, and 14A to 14C, which are not described herein again.

The specific connection medium among the transceiver 910, the processor 920 and the memory 930 is not limited in the embodiments of the present application. In the embodiment of the present application, the memory 930, the processor 920, and the transceiver 910 are connected through the bus 940 in fig. 9C, the bus is represented by a thick line in fig. 9C, and the connection manner between other components is merely illustrative and is not limited thereto. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, fig. 9C is shown with only one thick line, but does not show only one bus or one type of bus.

An embodiment of the present application provides a session management apparatus, where the apparatus is applied to a terminal, and as shown in fig. 10A, the apparatus includes:

a receiving module 1001a, configured to receive a message sent by a base station and used to instruct the terminal to delete or suspend a radio resource corresponding to a PDU session;

the processing module 1002a is configured to delete or suspend the radio resource corresponding to the PDU session, and set the status of the PDU session to an idle status.

In a possible design, the processing module 1002a is further configured to set the status of the PDU session to an idle state when the receiving module 1001a receives a message sent by the base station and used to instruct the terminal to delete or suspend the radio resource corresponding to the PDU session and determine that all the radio resources corresponding to the PDU session are deleted or suspended.

In a possible design, the receiving module 1001a is further configured to receive, before receiving a message sent by a base station and used to instruct the terminal to delete or suspend radio resources corresponding to a PDU session, a timer of the PDU session sent by a first core network device when the PDU session is activated;

the device further comprises:

the sending module 1003a is further configured to send, to the first core network device, a first message for invalidating the operation of the PDU session when the processing module 1002a monitors that there is no data transmission on the PDU session and the timer is expired.

In a possible design, the receiving module 1001a is further configured to receive, when the PDU session is activated, first indication information sent by the first core network device, where the first indication information is information used to indicate that the operation of the PDU session is not valid.

An embodiment of the present application provides a session management apparatus, where the apparatus is applied to a terminal, and as shown in fig. 10B, the apparatus includes:

a receiving module 1003b, configured to receive uplink data or receive a paging request;

a processing module 1001b, configured to determine that the receiving module receives uplink data or receives a paging request;

a sending module 1002b, configured to send a request message to a network device, where the request message carries an identifier of a PDU session and/or carries first state information of a QoS flow corresponding to the PDU session, and the first state information indicates that a state of the QoS flow on the terminal is an active state or an inactive state, and is used for the network device and the terminal to synchronize a state of the QoS flow.

In a possible design, the receiving module 1003a is further configured to receive second status information of a QoS flow corresponding to the PDU session, where the second status information indicates that a status of the QoS flow on the base station is an active status or an inactive status;

the processing module 1001b is further configured to synchronize a state of the QoS flow corresponding to the PDU session with the base station based on the second state information.

In a possible design, the receiving module 1003a is further configured to receive a mapping relationship between a QoS flow corresponding to the PDU session and a DRB sent by the base station;

the processing module 1001b is further configured to save the mapping relationship.

In a possible design, the receiving module 1003a is further configured to receive third status information of a QoS flow corresponding to the PDU session, where the third status information indicates that a status of the QoS flow corresponding to the PDU session on the first core network device is an active status or an inactive status;

the processing module 1001b is further configured to synchronize a state of the QoS flow corresponding to the PDU session with the first core network device based on the third flow state information.

An embodiment of the present application provides a session management apparatus, where the apparatus is applied to a terminal, and as shown in fig. 10D, the apparatus includes:

a receiving module 1001d, configured to receive, in a process that a terminal is switched from a currently accessed source base station to a target base station, a message sent by the source base station or a fourth core network device and used to instruct to execute an operation of invalidating a first type of packet data unit PDU session;

a processing module 1002d, configured to perform an operation of invalidating the first type PDU session based on the message.

As shown in fig. 10C, the terminal may include a processor 1020. The hardware of the entity corresponding to the module shown in fig. 10A, 10B or 10D may be the processor 1020. The processor 1020 may be a Central Processing Unit (CPU), a digital processing module, or the like. The terminal may also include a transceiver 1010, and the processor 1020 may receive data, messages, etc. via the transceiver 1010. The device also includes: a memory 1030 for storing programs executed by processor 1020. The memory 1030 may be a nonvolatile memory such as a hard disk (HDD) or a solid-state drive (SSD), and may also be a volatile memory such as a random-access memory (RAM). The memory 1030 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such.

The processor 1020 is configured to execute the program codes stored in the memory 1030, and in particular, is configured to execute the method performed by the terminal in the embodiment shown in fig. 3 to 7, 13, and 14A to 14C. Reference may be made to the methods described in the embodiments shown in fig. 3 to 7, 13, and 14A to 14C, which are not repeated herein.

The specific connection medium among the transceiver 1010, the processor 1020 and the memory 1030 is not limited in the embodiments of the present application. In the embodiment of the present application, the memory 1030, the processor 1020, and the transceiver 1010 are connected by a bus 1040 in fig. 10C, the bus is indicated by a thick line in fig. 10C, and the connection manner between other components is merely illustrative and not limited thereto. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 10C, but this does not indicate only one bus or one type of bus.

An embodiment of the present application provides a session management apparatus, where the apparatus is applied to a second core network device, as shown in fig. 11A, and includes:

a receiving module 1101, configured to receive a message sent by a first core network device, where the message carries an identifier of a PDU session to be deleted, and is used to instruct the second core network device to delete information related to a base station corresponding to the PDU session corresponding to the identifier or delete information related to the PDU session;

a processing module 1102, configured to delete the information related to the base station corresponding to the PDU session or delete the information related to the PDU session.

In a possible design, the receiving module 1101 is further configured to receive a timer of the PDU session sent by the first core network device when the PDU session is activated;

the device further comprises:

a sending module 1103, configured to monitor, at the processing module 1102, that there is no data transmission on the PDU session, and continue to send, until the timer expires, a first message to invalidate an operation of the PDU session to the first core network device.

In a possible design, the receiving module 1101 is further configured to receive, when a PDU session is activated, indication information sent by the first core network device, where the indication information is information indicating that the operation of the PDU session is disabled.

As shown in fig. 11B, the second core network device may include a processor 1120. The hardware of the entity corresponding to the module shown in fig. 11A may be the processor 1120. The processor 1120 may be a Central Processing Unit (CPU), a digital processing module, or the like. The second core network device may further include a communication interface 1110, and the processor 1120 receives data and messages through the communication interface 1110. The device also includes: a memory 1130 for storing programs executed by the processor 1120. The memory 1130 may be a nonvolatile memory such as a hard disk (HDD) or a solid-state drive (SSD), and may also be a volatile memory such as a random-access memory (RAM). The memory 1130 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such.

The processor 1120 is configured to execute the program code stored in the memory 1130, and in particular, is configured to execute the method executed by the second core network device in the embodiments shown in fig. 3 to 7, 13, and 14A to 14C. Reference may be made to the methods described in the embodiments shown in fig. 3 to 7, 13, and 14A to 14C, which are not repeated herein.

The specific connection medium among the communication interface 1110, the processor 1120, and the memory 1130 is not limited in the embodiments of the present application. In the embodiment of the present application, the memory 1130, the processor 1120 and the communication interface 1110 are connected by the bus 1140 in fig. 11B, the bus is represented by a thick line in fig. 11B, and the connection manner between other components is only schematically illustrated and is not limited thereto. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 11B, but this is not intended to represent only one bus or type of bus.

An embodiment of the present application provides a session management apparatus, where the apparatus is applied to a fourth core network device, and as shown in fig. 12A, the apparatus includes:

a receiving module 1201, configured to receive, during a cell handover process, an identifier of a PDU session sent by a base station;

a processing module 1202, configured to determine, based on the identifier of the PDU session, that a PDU session of a user plane context needs to be updated;

a sending module 1203, configured to send, to a first core network device, a message for notifying the first core network device to update a user plane context of the PDU session.

In one possible design, the receiving module 1201 is further configured to:

the processing module 1202 is further configured to set the stored status of the PDU session to an idle status, or delete the status information of the PDU session.

An embodiment of the present application provides a session management apparatus, where the apparatus is applied to a fourth core network device, as shown in fig. 12C, and includes:

a receiving module 1201c, configured to receive an identifier of a second type PDU session sent by a source base station or a target base station in a process that a terminal is switched from the source base station to the target base station;

a sending module 1202c, configured to send, to a first core network device, a message for notifying the first core network device to update a context of the second-type PDU session.

In a possible design, the receiving module 1201c is specifically configured to receive a path switching message sent by the target base station, where the path switching message carries an identifier of the second type PDU session.

In a possible design, the receiving module 1201c is specifically configured to receive a handover request sent by the source base station, where the handover request carries an identifier of the second type PDU session.

In one possible design, the apparatus further includes:

a processing module 1203c, configured to determine a first type PDU session based on an identifier of the second type PDU session, where the first type PDU session is a PDU session that is saved by the fourth core network device and is activated by the terminal, and is other than the second type PDU session corresponding to the identifier;

In a possible design, the processing module 1203c is further configured to, after determining a first type PDU session based on the identifier of the first type PDU session, convert the state of the first type PDU session from an active state to an idle state or delete the first type PDU session.

In a possible design, the receiving module 1201c is further configured to receive an identifier of a PDU session of a third type sent by the source base station or the target base station, where the PDU session of the third type is the PDU session recorded in the inactive state;

the sending module 1202c is configured to send, to the first core network device, a message used for instructing to execute an operation of invalidating the third-type PDU session.

In one possible design, the apparatus further includes:

a processing module 1203c, configured to convert the state of the third type PDU session from an active state to an idle state or delete the third type PDU session after the receiving module 1201c receives the identifier of the third type PDU session sent by the source base station or the target base station.

In one possible design, the sending module 1202c is further configured to: after the receiving module 1201c receives the identifier of the third type PDU session sent by the source base station or the target base station, the identifier of the third type PDU session is sent to the terminal, so as to instruct the terminal to set the state of the third type PDU session to an idle state.

As shown in fig. 12B, the fourth core network device may include a processor 1220. The hardware of the entity corresponding to the module shown in fig. 12A or fig. 12C may be the processor 1220. The processor 1220 may be a Central Processing Unit (CPU), a digital processing module, or the like. The fourth core network device may further include a communication interface 1210, and the processor 1220 may receive data and messages through the communication interface 1210. The device also includes: a memory 1230 for storing programs executed by the processor 1220. The memory 1230 may be a nonvolatile memory such as a hard disk (HDD) or a solid-state drive (SSD), and may also be a volatile memory such as a random-access memory (RAM). The memory 1230 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such.

The processor 1220 is configured to execute the program codes stored in the memory 1230, and in particular, is configured to execute the method executed by the fourth core network device in the embodiments shown in fig. 3 to 7, 13, and 14A to 14C. Reference may be made to the methods described in the embodiments shown in fig. 3 to 7, 13, and 14A to 14C, which are not repeated herein.

The specific connection medium among the communication interface 1210, the processor 1220 and the memory 1230 is not limited in the embodiments of the present application. In fig. 12B, the memory 1230, the processor 1220 and the communication interface 1210 are connected by a bus 1240, the bus is represented by a thick line in fig. 12B, and the connection manner among other components is only for illustrative purposes and is not limited thereto. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 12B, but this is not intended to represent only one bus or type of bus.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present application without departing from the scope of the embodiments of the present application. Thus, if such modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to encompass such modifications and variations.

Claims

1. A session management method, comprising:

a first device receives a request message for activating a Packet Data Unit (PDU) session;

the first device sends a timer of the PDU session to a second device;

the first device receives a first message initiated by the second device to invalidate the operation of the PDU session; the first message is issued by the second device detecting no data transmission on the PDU session and persisting until the timer times out.

2. The method of claim 1, wherein the first device is a first core network device, and the second device is a second core network device, or a base station, or a terminal.

3. The method of claim 1, wherein the operation of invalidating the PDU session comprises: and converting the PDU session from an active state to an idle state or deleting the PDU session.

4. The method of any of claims 1 to 3, wherein prior to the first device sending the timer to the second device, the method further comprises:

the first device determining a timer of the PDU session based on slice information of a network slice to which the PDU session belongs; alternatively, the first and second electrodes may be,

5. The method of any of claims 1 to 3, further comprising:

6. The method of any of claims 1 to 3, further comprising:

and after receiving the request message, the first device receives indication information sent by a third core network device, wherein the indication information is used for indicating the operation of invalidating the PDU session.

7. The method of claim 6, wherein the method further comprises:

and after receiving the first message, the first device determines, based on the indication information, that the operation of invalidating the PDU session is to convert the PDU session from an active state to an idle state or to delete the PDU session.

8. A method according to any of claims 1 to 3, wherein the first message carries an identity of the PDU session.

9. The method of claim 8, wherein the first message further carries a cause value indicating a timer timeout for the PDU session.

10. The method of any of claims 1 to 3, wherein the operation of invalidating the PDU session is to transition the PDU session from an active state to an idle state, the method further comprising:

and after receiving the first message, the first device sends a message for indicating to delete the information related to the base station and corresponding to the PDU session to a second core network device.

11. The method of any of claims 1 to 3, wherein the operation of invalidating the PDU session is to transition the PDU session from an active state to an idle state, the method further comprising:

12. The method according to any of claims 1 to 3, wherein said operation of invalidating said PDU session is deleting said PDU session, said method further comprising:

and after receiving the first message, the first device sends a message for indicating to delete the information related to the PDU session to a second core network device.

13. The method according to any of claims 1 to 3, wherein said operation of invalidating said PDU session is deleting said PDU session, said method further comprising:

and after receiving the first message, the first device sends a message for indicating the terminal to delete the information related to the PDU session to the terminal.

14. The method of any of claims 1 to 3, further comprising:

and after receiving the first message, the first device sends a message for indicating the base station to release the context of the PDU session to the base station.

15. The method of any of claims 1 to 3, further comprising:

and after receiving the first message, the first device sends a message for instructing the fourth core network device to set the state of the PDU session to an idle state to the fourth core network device.

16. The method of any of claims 1 to 3, further comprising:

the first equipment receives a second message sent by fourth core network equipment, wherein the second message carries an identification of a PDU session of a user plane context to be updated;

and the first equipment updates the user plane context of the PDU session corresponding to the identification of the PDU session.

17. A session management method, comprising:

when a Packet Data Unit (PDU) session is activated, a base station receives a timer of the PDU session sent by first core network equipment;

and the base station detects that no data is transmitted on the PDU session and continuously sends a first message for invalidating the operation of the PDU session to the first core network equipment when the timer is timed out.

18. The method of claim 17, wherein the operation of invalidating the PDU session comprises: and converting the state of the PDU session from an active state to an idle state or deleting the PDU session.

19. The method of claim 17, wherein the method further comprises:

20. The method according to any of claims 17 to 19, wherein the first message carries an identification of the PDU session.

21. The method of claim 20, wherein the first message further carries a cause value indicating a timer timeout for the PDU session.

22. The method of any of claims 17 to 19, further comprising:

the base station receives a message which is sent by the first core network equipment and used for indicating the base station to release the context of the PDU;

and the base station deletes or suspends the wireless resources corresponding to the PDU session.

23. The method of claim 22, wherein the method further comprises:

and the base station sets the stored PDU conversation state to be an idle state.

24. The method of any of claims 17 to 19, further comprising:

25. The method of any of claims 17 to 19, further comprising:

and the base station monitors that no data is transmitted on the PDU session and continues to send a message for indicating the terminal to delete or suspend the wireless resources corresponding to the PDU session to the terminal after the timer is overtime.

26. The method of claim 25, wherein the message for instructing the terminal to delete or suspend radio resources corresponding to the PDU session carries: the radio resource to be deleted or suspended carries the identity of the DRB.

27. A session management method, comprising:

when a Packet Data Unit (PDU) session is activated, a terminal receives a timer of the PDU session sent by first core network equipment;

the terminal monitors that no data is transmitted on the PDU session and continues to send a first message for invalidating the operation of the PDU session to the first core network equipment when the timer is timed out;

a terminal receives a message which is sent by a base station and used for indicating the terminal to delete or suspend wireless resources corresponding to a PDU session;

and the terminal deletes or suspends the wireless resource corresponding to the PDU session and sets the state of the PDU session to be an idle state.

28. The method of claim 27, wherein the method further comprises:

and after receiving the message which is sent by the base station and used for indicating the terminal to delete or suspend the wireless resources corresponding to the PDU session, the terminal sets the state of the PDU session to be an idle state when judging that all the wireless resources corresponding to the PDU session are deleted or suspended.

29. The method of claim 27, wherein the operation of invalidating the PDU session comprises: and converting the state of the PDU session from an active state to an idle state or deleting the PDU session.

30. The method of claim 27 or 29, wherein the method further comprises:

31. A session management method, comprising:

when a Packet Data Unit (PDU) session is activated, a second core network device receives a PDU session timer sent by a first core network device;

the second core network equipment monitors that no data is transmitted on the PDU session and continues to send a first message for invalidating the operation of the PDU session to the first core network equipment until the timer is overtime;

32. The method of claim 31, wherein the method further comprises:

33. A session management apparatus, applied to a first device, comprising:

34. The apparatus of claim 33, wherein the first device is a first core network device, and the second device is a second core network device, or a base station, or a terminal.

35. The apparatus of claim 33, wherein the operation of invalidating the PDU session comprises: and converting the PDU session from an active state to an idle state or deleting the PDU session.

36. The apparatus of any one of claims 33 to 35, further comprising:

37. The apparatus of any of claims 33 to 35, wherein the receiving module is further configured to receive a timer of the PDU session sent by a third core network device.

38. The apparatus of any of claims 33 to 35, wherein the sending module is further configured to send indication information to the second device, where the indication information is information indicating the operation of invalidating the PDU session.

39. The apparatus of any one of claims 33 to 35, wherein the receiving module is further configured to receive indication information sent by a third core network device after receiving the request message, where the indication information is information for indicating the operation of invalidating the PDU session.

40. The apparatus of claim 39, further comprising: a second determining module, configured to determine, based on the indication information, that the operation of invalidating the PDU session is to convert the PDU session from an active state to an idle state or to delete the PDU session after the receiving module receives the first message.

41. The apparatus according to any of claims 33 to 35, wherein the first message carries an identification of the PDU session.

42. The apparatus of claim 41, wherein the first message further carries a cause value indicating a timer timeout for the PDU session.

43. The apparatus of any of claims 33 to 35, wherein the operation of invalidating the PDU session is to convert the PDU session from an active state to an idle state, and wherein the receiving module is further configured to send, after receiving the first message, a message indicating to delete the base station related information corresponding to the PDU session to a second core network device.

44. The apparatus according to any of claims 33 to 35, wherein said invalidating the PDU session is operative to transition the PDU session from an active state to an idle state, the apparatus further comprising:

45. The apparatus according to any of claims 33 to 35, wherein the operation of invalidating the PDU session is deleting the PDU session, and the sending module is further configured to send, after the receiving module receives the first message, a message indicating deletion of information related to the PDU session to a second core network device.

46. The apparatus according to one of claims 33 to 35, wherein the operation of invalidating the PDU session is deleting the PDU session, and wherein the sending module is further configured to send a message to a terminal instructing the terminal to delete the information related to the PDU session after receiving the first message.

47. The apparatus of any one of claims 33 to 35, wherein the sending module is further configured to send a message to the base station instructing the base station to release the context of the PDU session after the receiving module receives the first message.

48. The apparatus of any one of claims 33 to 35, wherein the sending module is further configured to send, to a fourth core network device, a message for instructing the fourth core network device to set the status of the PDU session to an idle state after the receiving module receives the first message.

49. The apparatus according to any one of claims 33 to 35, wherein the receiving module is further configured to receive a second message sent by a fourth core network device, where the second message carries an identifier of a PDU session of a user plane context to be updated;

the device further comprises:

50. A session management apparatus, applied to a base station, comprising:

a sending module, configured to send, to the first core network device, a first message that invalidates the operation of the PDU session.

51. The apparatus of claim 50, wherein the operation of invalidating the PDU session comprises: and converting the state of the PDU session from an active state to an idle state or deleting the PDU session.

52. The apparatus of claim 50, wherein the receiving module is further configured to receive indication information sent by the first core network device when a PDU session is activated, where the indication information is information for indicating the operation of invalidating the PDU session.

53. The apparatus according to any of claims 50 to 52, wherein the first message carries an identification of the PDU session.

54. The apparatus of claim 53, wherein the first message further carries a cause value indicating a timer timeout for the PDU session.

55. The apparatus according to any of claims 50 to 52, wherein the receiving module is further configured to receive a message sent by the first core network device to instruct the base station to release the context of the PDU;

56. The apparatus of claim 55, wherein the processing module is further configured to:

and setting the saved state of the PDU conversation to be an idle state.

57. The apparatus of any of claims 50 to 52, wherein the processing module is further configured to delete the mapping relationship between the QoS flow corresponding to the PDU session and the DRB after monitoring that there is no data transmission in the PDU session and continuing until the timer expires.

58. The apparatus of any one of claims 50 to 52, wherein the sending module is further configured to send a message to the terminal for instructing the terminal to delete or suspend the radio resource corresponding to the PDU session after the processing module monitors that there is no data transmission in the PDU session and continues until the timer expires.

59. The apparatus of claim 58, wherein the message for instructing the terminal to delete or suspend radio resources corresponding to the PDU session carries: the radio resource to be deleted or suspended carries the identity of the DRB.

60. A session management apparatus, applied to a terminal, comprising:

the processing module is used for deleting or suspending the wireless resources corresponding to the PDU session and setting the state of the PDU session to be an idle state;

the receiving module is further configured to receive, before receiving a message sent by a base station and used to instruct the terminal to delete or suspend radio resources corresponding to a PDU session, a timer of the PDU session sent by a first core network device when the PDU session is activated;

the device further comprises:

61. The apparatus of claim 60, wherein the processing module is further configured to set the status of the PDU session to an idle state when the receiving module receives a message sent by the base station and used to instruct the terminal to delete or suspend the radio resource corresponding to the PDU session and determines that all the radio resources corresponding to the PDU session are deleted or suspended.

62. The apparatus of claim 61, wherein the operation of invalidating the PDU session comprises: and converting the state of the PDU session from an active state to an idle state or deleting the PDU session.

63. The apparatus of claim 61 or 62, wherein the receiving module is further configured to receive first indication information sent by the first core network device when the PDU session is activated, where the first indication information is information for indicating the operation of invalidating the PDU session.

64. A session management apparatus, applied to a second core network device, includes:

the processing module is used for deleting the information related to the base station corresponding to the PDU session or deleting the information related to the PDU session;

the receiving module is further configured to receive a timer of the PDU session sent by the first core network device when the PDU session is activated;

the device further comprises:

65. The apparatus of claim 64, wherein the operation of invalidating the PDU session comprises: and converting the state of the PDU session from an active state to an idle state or deleting the PDU session.

66. The apparatus of claim 64 or 65, wherein the receiving module is further configured to receive indication information sent by the first core network device when a PDU session is activated, where the indication information is information indicating the operation of disabling the PDU session.

67. A session management method, comprising:

68. The method of claim 67, wherein the source base station performs a handover procedure for the second type PDU session, comprising:

69. The method of claim 67 or 68, further comprising:

70. The method of claim 69, wherein the message for instructing the terminal to perform the operation of invalidating the PDU sessions of the first type carries: an identification of the first type PDU session; alternatively, the first and second electrodes may be,

71. The method of claim 69, wherein said invalidating the PDU sessions of the first type comprises: and converting the state of the first type PDU conversation from an active state to an idle state or deleting the first type PDU conversation.

72. The method of claim 67, wherein the source base station performs a handover procedure for the second type PDU session, comprising:

73. A session management method, comprising:

a target base station to be switched in by a terminal receives a switching request sent by a source base station to which the terminal is currently accessed, wherein the switching request only carries an identifier of a second PDU session; or, the switching request carries the identifier of the first type PDU session and the identifier of the second type PDU session; or, the handover request carries an identifier of an activated PDU session of the terminal and a first indication, where the first indication is used to mark a first type of PDU session in the identifier of the activated PDU session of the terminal;

wherein, each active PDU session of the terminal is configured with a corresponding timer when being established or activated; the first type of PDU session is a PDU session recorded in an inactive state; the PDU session recorded as inactive refers to the PDU session which meets the condition that no data transmission continues until the corresponding timer is overtime; the second type PDU session is a PDU session except the first type PDU session in the activated PDU session of the terminal;

74. The method of claim 73, wherein the message for instructing the fourth core network device to perform the operation of invalidating the PDU sessions of the first type carries: identification of the first type PDU session.

75. The method according to claim 73 or 74, wherein said operation of invalidating said first type PDU session comprises: and converting the state of the first type PDU conversation from an active state to an idle state or deleting the first type PDU conversation.

76. A session management method, comprising:

77. The method of claim 76, wherein the receiving, by the fourth core network device, the identification of the second-type PDU session sent by the target base station comprises:

78. The method of claim 76, wherein the fourth core network device receiving the identification of the second type PDU session sent by the source base station comprises:

79. The method of any one of claims 76 to 78, further comprising:

80. The method of claim 79, wherein the operation of invalidating the first type of PDU session comprises transitioning the status of the first type of PDU session from active to idle or deleting the first type of PDU session.

81. The method of claim 79, wherein after the fourth core network device determines the first type of PDU session based on the identity of the first type of PDU session, the method further comprises:

82. The method of any one of claims 76 to 78, further comprising:

83. The method of claim 82, wherein said operation of invalidating said third type PDU session comprises:

84. The method of claim 82, wherein after the fourth core network device receives the identifier of the third type PDU session sent by the source base station or the target base station, the method further comprises:

85. The method of claim 82, wherein after the fourth core network device receives the identifier of the third type PDU session sent by the source base station or the target base station, the method further comprises:

86. A session management method, comprising:

87. The method of claim 86, wherein the message instructing the terminal to perform the operation of invalidating Packet Data Unit (PDU) sessions of the first type carries: identification of the first type of PDU session.

88. The method of claim 86, wherein the message indicating to perform the operation of invalidating Packet Data Unit (PDU) sessions of the first type carries: the terminal comprises an identification of the terminal's active PDU sessions and a first indication, wherein the first indication is used for marking the first class PDU session in the terminal's active PDU sessions;

89. The method according to one of claims 86 to 88, wherein said operation of invalidating said first type of PDU session comprises:

90. A session management apparatus, applied to a source base station, comprising:

91. The apparatus of claim 90, further comprising:

92. The apparatus of claim 90, further comprising:

93. The apparatus of claim 92, wherein the message for instructing the terminal to perform the operation of invalidating the first type PDU sessions carries: an identification of the first type PDU session; alternatively, the first and second electrodes may be,

94. The apparatus of claim 92 or 93, wherein the operation of invalidating the first type of PDU session comprises: and converting the state of the first type PDU conversation from an active state to an idle state or deleting the first type PDU conversation.

95. The apparatus of claim 90, further comprising:

a sending module, configured to send a handover request to a fourth core network device when the processing module executes a handover procedure for a second type PDU session, where the handover request only carries an identifier of the second type PDU session; alternatively, the first and second electrodes may be,

96. A session management apparatus, wherein the apparatus applies a target base station, comprising:

the receiving module is used for receiving a switching request sent by a source base station which is currently accessed by a terminal, wherein the switching request only carries an identifier of a second type PDU session; or, the switching request carries the identifier of the first type PDU session and the identifier of the second type PDU session; or, the handover request carries an identifier of an activated PDU session of the terminal and a first indication, where the first indication is used to mark a first type of PDU session in the identifier of the activated PDU session of the terminal;

97. The apparatus of claim 96, wherein the message for instructing the fourth core network device to perform the operation of invalidating the first type PDU sessions carries: identification of the first type PDU session.

98. The apparatus according to claim 96 or 97, wherein the operation of invalidating the PDU sessions of the first type comprises: and converting the state of the first type PDU conversation from an active state to an idle state or deleting the first type PDU conversation.

99. A session management apparatus, applied to a fourth core network device, includes:

100. The apparatus of claim 99, wherein the receiving module is specifically configured to receive a path switching message sent by the target base station, and the path switching message carries an identifier of the second-type PDU session.

101. The apparatus of claim 99, wherein the receiving module is specifically configured to receive a handover request sent by the source base station, and the handover request carries an identifier of the second type PDU session.

102. The apparatus of any one of claims 99 to 101, wherein the apparatus further comprises:

103. The apparatus of claim 102, wherein the operation of invalidating the first type of PDU sessions comprises transitioning a status of the first type of PDU sessions from an active state to an idle state or deleting the first type of PDU sessions.

104. The apparatus of claim 102, wherein the processing module is further configured to change the status of the first type of PDU sessions from active to idle or delete the first type of PDU sessions after determining the first type of PDU sessions based on the identity of the first type of PDU sessions.

105. The apparatus according to any of claims 99 to 101, wherein the receiving module is further configured to receive an identifier of a third type PDU session sent by the source base station or the target base station, where the third type PDU session is the PDU session recorded in the inactive state;

106. The apparatus as claimed in claim 105, wherein said operation of invalidating said third type PDU session comprises:

107. The apparatus of claim 105, wherein the apparatus further comprises:

108. The apparatus of claim 105, wherein the means for transmitting is further for: and after the receiving module receives the identifier of the third PDU session sent by the source base station or the target base station, sending the identifier of the third PDU session to the terminal for indicating the terminal to set the state of the third PDU session to an idle state.

109. A session management apparatus, wherein the apparatus applied to a terminal comprises:

110. The apparatus of claim 109, wherein the message instructing the terminal to perform the operation of invalidating Packet Data Unit (PDU) sessions of a first type carries: identification of the first type of PDU session.

111. The apparatus of claim 109, wherein the message indicating to perform the operation of invalidating Packet Data Unit (PDU) sessions of the first type carries: the terminal comprises an identification of the terminal's active PDU sessions and a first indication, wherein the first indication is used for marking the first class PDU session in the terminal's active PDU sessions;

112. The apparatus according to one of claims 109 to 111, wherein said operation of invalidating said first type PDU session comprises: