WO2019047209A1

WO2019047209A1 - Session management method and terminal

Info

Publication number: WO2019047209A1
Application number: PCT/CN2017/101208
Authority: WO
Inventors: 窦凤辉; 金辉; 欧阳国威; 杨皓睿; 李小娟
Original assignee: 华为技术有限公司
Priority date: 2017-09-11
Filing date: 2017-09-11
Publication date: 2019-03-14
Also published as: CN110140333B; CN110140333A

Abstract

The embodiments of the present application relate to a session management method and terminal. The method comprises: a terminal receiving a first message, sent by an access and mobility management function (AMF) entity, said first message comprising or not comprising information of a local area data network (LADN); according to the first message, the terminal determining that a change has occurred in the state of availability of the LADN; the terminal modifying or releasing the PDU session. The embodiments of the present application reduce the data loss caused by modifying a network or releasing a PDU session when a terminal is in an idle state, and also reduce signaling waste caused by a network device paging a terminal when the PDU session of the accessed LADN has downlink data that has arrived.

Description

Method and terminal for session management

Technical field

The embodiments of the present invention relate to the field of communications technologies, and in particular, to a method and a terminal for session management.

Background technique

In the 5G network, the concept of a Local Area Data Network (LADN) is introduced. When the terminal is in the Registration Procedure, the access and mobility management function (AMF) is directed to the terminal. Provide LADN information (for example, LADN availability information), LADN availability information includes LADN data network name (LADN DNN) and LADN service area (LADN Service Area), the service area of the LADN For a specific tracking area (TA) in the terminal registration area, when the terminal is located within the LADN Service Area, a protocol data unit (PDU) session with the LADN can be established. After the LADN Servcie Area is removed, the transfer of LADN-based data will not be possible.

Generally, the Access and Mobility Management Function (AMF) provides a session management function (SMF) with information about whether the terminal is in the LADN Service Area, so that the SMF determines whether the terminal can establish a session for accessing the LADN, or The session of the currently established LADN is managed to ensure that the LADN-based data can be transmitted only when the terminal is in the LADN Service Area.

After the SMF determines that the terminal moves out of the service area of the LADN, the user plane function (UPF) may be notified to discard the downlink data of the session accessing the LADN or stop sending the downlink data notification related to the session to the SMF (Downlink Data Notification, DDN), however, when the terminal is in an idle state, data loss may occur. After the SMF determines that the terminal moves out of the service area of the LADN, the SMF does not notify the UPF to discard the downlink data of the session or stop sending the DDN related to the session to the SMF. At this time, signaling resources may be wasted.

Summary of the invention

The embodiment of the present application provides a method and a device for session management. To achieve the management of the session accessing the LADN, the problem of data loss or signaling waste is reduced.

In a first aspect, a method of session management is provided. The terminal has a PDU session that accesses the LADN. The method includes: receiving, by the terminal, a first message sent by the access and mobility management function entity AMF in a first registration area (RA), where the first message includes or The information of the LADN is not included; wherein the first RA is a current registration area of the terminal; the terminal determines, according to the first message, that an available state of the LADN changes; the terminal modifies or releases the PDU session. The first message may be a Registration Accept message or a UE Configration Update Command (UE Configration Update Command), and the LADN information may be available information of the LADN. With the embodiment of the present application, for the LADN session, when the terminal enters the information registration area that does not support the LADN from the registration area of the information supporting the LADN, the terminal modifies or releases the PDU session, or the terminal does not support the LADN information. When the registration area enters the registration area of the information supporting the LADN, the terminal modifies the PDU session, thereby reducing the time when the terminal is in the idle state. The registration area does not include the LADN information, and the network device wastes signaling caused by paging the terminal because the downlink data arrives in the PDU session of the access LADN.

It can be understood that the LADN information is not included in the first message, and the LADN information in the first message is not available, or the LADN information in the first message is empty, or the first message includes other indication information indicating that there is no LADN. The information is not specifically limited in the present invention.

It should be noted that the terminal has a PDU session accessing the LADN, and the terminal may save the context of the PDU session in which the LADN is accessed, where the context of the PDU session may include one or more of the following: an identifier of the PDU session; Session service continuity (SSC) mode of the session; type of PDU session (eg IP type), ethernet type, unstructured type, etc.; data network name corresponding to the PDU session (data network Name, DNN); network slice information corresponding to the PDU session (eg, single network slice selection information (S-NSSAI)), network slice identification (NSI), etc.; quality of service flow identification (QoS) of the PDU session Flow identifier, QFI), QoS parameters corresponding to the QoS flow, such as 5G QoS indicator (5QI), guaranteed flow bit rate (GFBR), maximum flow bit rate (MFBR) ), session aggregate maximum bit rate (Session-AMBR), radio bearer corresponding to the PDU session Information, such as data radio bearer (data radio bearer, DRB), which the UE may establish an access session LADN a PDU, the terminal may transmit data through the downlink PDU session. Specifically, the PDU session accessing the LAND means that the DNN attribute corresponding to the PDU session is the LADN DNN.

In a first optional implementation of the first aspect, the terminal determines, according to the first message, that the available state of the LADN changes, including: when the first message does not include information of the LADN, further, the When the terminal determines that the second registration area includes the information of the LADN, the terminal determines that the information of the LADN in the registration area changes; or, when the first message does not include the information of the LADN, and the first registration area When the information of the LADN is included before the first message is received, the terminal determines that the information of the LADN in the registration area changes; wherein the first registration area is a current registration area of the terminal, where The second registration area is a registration area before the terminal enters the current registration area.

In a second optional implementation of the first aspect, the terminal modifying the PDU session includes: the terminal sending a first session modification request message to the SMF, where the first session modification request message includes a first indication, where the first indication is used Indicates information when the first RA does not include the LADN. It can be understood that the terminal also needs to access the identifier of the PDU session of the LADN to the SMF. The identifier of the PDU session may be included in the first session modification request message, or may be included in the NAS message sent by the terminal to the AMF. It is then forwarded to the SMF by AMF. The PDU session can be managed based on the current registration area and the service area of the LADN, and the granularity is fine.

In a third optional implementation of the first aspect, the terminal releasing the PDU session includes: the terminal sending a session release request message to the session management entity SMF. The embodiment of the present application can be implemented, when the terminal is located outside the service area of the LADN, the terminal initiates the release of the PDU session, thereby reducing the existence of the PDU session, but the terminal is not in the service area of the LADN, and the paging terminal is caused by the paging terminal. Signaling is wasted.

In a fourth optional implementation of the first aspect, the method further includes: receiving, by the terminal, a first session modification command message sent by the SMF, where the first session modification command message includes an identifier of the PDU session and a first parameter, where the A parameter is used to indicate that the PDU session is unavailable, and the identity of the PDU session is used to identify the PDU session. The PDU session is unavailable, including one or more of the following combinations: the user plane connection of the LADN session has been released; the UPF has been notified of the loss. The downlink data of the LADN session is discarded; the UPF is notified to stop sending the downlink data notification (DDN) related to the session to the SMF, and the gate corresponding to the LADN session is set to be closed. After the PDU session is modified or released on the network side, the terminal is notified, so that the terminal can modify or release the PDU session synchronously, thereby reducing the existence of the PDU session, but the terminal is not in the service area of the LADN. , signaling waste caused by paging terminals.

In a fifth alternative implementation of the first aspect, the method further comprises the terminal marking the PDU session as unavailable. The embodiment of the present application can be implemented that, by marking the PDU session, the terminal can count the number of times that the terminal continuously enters the registration area of the service area that does not include the LADN, thereby setting a rule, and the registration area of the service area that does not include the LADN is less than or When the number of times is equal to the set number of times, the terminal modifies the PDU session. When the set number of times is reached or exceeded, the terminal releases the PDU session, and the management granularity of the PDU session accessing the LADN is finer.

In a sixth optional implementation of the first aspect, the terminal determines, according to the first message, that the available state of the LADN changes, including: when the first message includes information of the LADN, and receives the information at the terminal When the information of the LADN is not included in the first RA before the first message, the terminal determines that the available state of the LADN changes; or when the first message includes the information of the LADN, and the second When the information of the LADN is not included in the RA, the terminal determines that the available state of the LADN changes; the second RA is the RA before the terminal enters the first RA.

In a seventh optional implementation of the first aspect, the method further includes: the terminal sending a second session modification request message to the SMF, where the second session modification request message includes a second indication, where the second indication is used to indicate The information of the LADN is not included in the first RA. Through the embodiment of the present application, when the terminal re-enters the RA of the service area including the LADN, the PDU session of the access LADN is re-enabled for data transmission, thereby managing the PDU session from a finer granularity, and The network device is more reasonable for the paging of the terminal, saves signaling, and improves efficiency.

In an eighth optional implementation of the first aspect, the method further includes: receiving, by the terminal, a second session modification command message sent by the SMF, where the second session modification command message includes a second parameter, where the second parameter is used to indicate A PDU session is available. The embodiment of the present application can implement synchronization of the PDU session state between the network side and the terminal side, thereby reducing the possibility of data loss.

In a ninth alternative implementation of the first aspect, the method further comprises the terminal marking the PDU session as available. The embodiment of the present application can be implemented that, by marking the PDU session, the terminal can count the number of times that the terminal continuously enters the registration area of the service area that does not include the LADN, thereby setting a rule, and the registration area of the service area that does not include the LADN is less than or When the number of times is equal to the set number of times, the terminal modifies the PDU session. When the set number of times is reached or exceeded, the terminal releases the PDU session, and the management granularity of the PDU session accessing the LADN is finer.

With the embodiment of the present application, for the session of the LADN, when the terminal enters the registration area that does not support the LADN, the terminal modifies or releases the PDU session, thereby reducing the network device because the downlink data arrives in the PDU session of the access LADN. The signaling waste caused by the calling terminal. The PDU session can also be managed based on the current registration area and the service area of the LADN, with a fine granularity.

In a second aspect, a method of session management is provided. The SMF has a PDU session in which the terminal accesses the LADN, and the method includes: the SMF receiving the session modification request message sent by the terminal, where the session modification request message includes an indication, where the indication is used to indicate that the registration area includes or does not include the LADN information. The SMF modifies the PDU session according to the indication, and the LADN information may be the available information of the LADN. It can be realized by the embodiment of the present application, based on the current note The area of the book and the service area of the LADN are used to manage the PDU session with a finer granularity.

In a first alternative implementation of the second aspect, when the indication is used to indicate that the RA does not include the LADN, the SMF modifies the PDU session according to the indication, including: the SMF sends the first session modification command message to the terminal The first session modification command message includes an identifier of the PDU session and a first parameter, where the first parameter is used to indicate that the PDU session is unavailable. The PDU session can be managed based on the current registration area and the service area of the LADN, and the granularity is fine.

In a second alternative implementation of the second aspect, the SMF modifies the PDU session according to the indication, including one or more of the following: the SMF marks the PDU session as unavailable; the SMF notifies the user of the face function entity UPF to drop the Determining downlink data corresponding to the PDU session; the SMF notifies the UPF to stop sending the downlink data notification DDN to the SMF.

In a third optional implementation of the second aspect, when the indication is used to indicate that the RA does not include the information of the LADN, the SMF modifies the PDU session according to the indication, including: the SMF sends the second session modification to the terminal The command message, the second session modification command message includes an identifier of the PDU session and a second parameter, the second parameter is used to indicate that the PDU session is available. Through the embodiment of the present application, when the terminal re-enters the RA of the service area including the LADN, the PDU session of the access LADN is re-enabled for data transmission, thereby managing the PDU session from a finer granularity, and The network device is more reasonable for the paging of the terminal, saves signaling, and improves efficiency.

It can be understood that the SMF modifies the PDU session according to the indication, and the SMF modifies the PDU session according to the received identifier of the PDU session and the indication.

In a third aspect, a method of service subscription is provided. The SMF has a PDU session in which the terminal accesses the LADN. The method includes: the SMF subscribes to the AMF subscription notification service, and the notification service is used to notify the SMF when the preset event occurs, wherein the available state of the LADN changes. The embodiment of the present application can implement the change notification of the service area of the RA including the LADN that the SMF moves to the AMF subscription terminal by using the embodiment of the present application. When the condition is met, the AMF notifies the SMF. The granularity of PDU session management is finer.

In a first alternative implementation of the third aspect, the SMF subscribes to the AMF notification service, including: the SMF sends the data network name and the preset event of the LADN to the AMF to subscribe to the AMF subscription service. The change notification of the service area of the RA including the LADN to which the SMF moves to the AMF subscription terminal can be implemented by using the embodiment of the present application. The granularity of PDU session management is finer.

In a second alternative implementation of the third aspect, the available state of the LADN is changed, including at least one of the following: information of the LADN is not included in the first registration area, and the LADN is included in the second registration area The information in the first registration area is changed from information including the LADN to information not including the LADN; the first registration area includes information of the LADN, and the information of the LADN is not included in the second registration area; Or, the information that does not include the LADN in the first registration area is changed to information including the LADN; wherein the first registration area is a current registration area of the terminal, and the second registration area is the The terminal enters the registration area before the first registration area, and the LADN information may be the available information of the LADN.

In a third alternative implementation of the third aspect, the SMF receives the notification information sent by the AMF, the notification information being used to inform the terminal that the registration area includes or does not include information of the LADN. The SMF modifies the PDU session based on the notification information. The AMF notifies the RA that the terminal moves to include the change notification of the service area of the LADN, and the release or modification of the LADN session is initiated by the SMF, thereby reducing the message caused by the paging terminal because the network device has downlink data arrival of the PDU session of the access LADN. Make a waste.

In a fourth alternative implementation of the third aspect, the SMF modifies the PDU session based on the notification information, the packet When the notification information is used to notify the registration area of the terminal that the information of the LADN is not included, the SMF performs one or more of the following: notifying the user plane function entity UPF to discard the corresponding PDU session Downstream data; notifying that the UPF stops sending the downlink data notification DDN corresponding to the PDU session to the SMF; or, when the notification information is used to notify the registration area of the terminal that the information of the LADN is included, the SMF performs One or more of the following: notifying the UPF to send downlink data corresponding to the PDU session; and informing the UPF to send a downlink data notification DDN corresponding to the PDU session. The embodiment of the present application can be implemented by the SMF to determine whether to initiate release or modification of the LADN session according to the support status of the LADN in the registration area, and the management granularity is fine, and the network device reduces the arrival of the downlink data by the PDU session of the access LADN. The signaling caused by the paging terminal is wasted, so that it is no longer necessary to page the terminal, which saves signaling.

Through the embodiment of the present application, the AMF notifies the SMF that the RA that the terminal moves to includes the change notification of the service area of the LADN, and the release or modification of the LADN session is initiated by the SMF, thereby reducing the network device because the PDU session of the access LADN is Downlink data arrives and signaling waste caused by paging terminals. Alternatively, the SMF can discard the downlink data when the PDU session is not modified, thereby eliminating the need to page the terminal and saving signaling.

In a fourth aspect, a method of service subscription is provided. The AMF has a PDU session in which the terminal accesses the LADN, and the method includes: the AMF receives a subscription notification service request sent by the SMF, where the notification service is used to notify the SMF when the preset event occurs, where the preset is The event changes for the available state of the LADN, where the LADN information can be the available information for the LADN. The change notification of the service area of the RA including the LADN to which the SMF moves to the AMF subscription terminal can be implemented by the embodiment of the present application. When the condition is met, the AMF notifies the SMF.

In a first alternative implementation of the fourth aspect, the AMF receives the subscription notification service request sent by the SMF, including:

The AMF receives the data network name DNN of the LADN and the preset event sent by the SMF to accept the SMF subscription notification service.

In a second alternative implementation of the fourth aspect, the available state of the LADN changes, including at least one of the following: the first registration area does not include information of the LADN, the second registration area includes information of the LADN, the first registration The area is changed from information including the LADN to information not including the LADN; the first registration area includes information of the LADN, and the second registration area does not include information of the LADN; the first registration area changes information that does not include the LADN The information includes the LADN; wherein the first registration area is a current registration area of the terminal, and the second registration area is a registration area before the terminal enters the first registration area.

In a third optional implementation of the fourth aspect, after the AMF receives the subscription notification service request sent by the SMF, the method further includes: the AMF sending the notification information to the SMF, where the notification information is used to notify the registration area of the terminal that the Information about the LADN is not included. The notification information may specifically include a LADN DNN and an indication, where the indication is used to indicate that the registration area does not include the LADN information.

The embodiment of the present application can implement that when the SMF does not modify the PDU session, the downlink data can be discarded, so that the terminal does not need to be paged again, and signaling is saved.

In a fifth aspect, a session management method is provided. The SMF has a PDU session for accessing the LADN, and the method includes: the SMF receiving a downlink data notification corresponding to the PDU session sent by the UPF; the SMF calling a first service provided by the AMF, where the first service is used by the SMF The SMF requests the AMF to send a message or information, such as N2 SM information, to the access node AN. The SMF receives an indication parameter sent by the AMF, where the indication parameter is used to indicate that the LADN information is not included in the current registration area; and the SMF modifies the PDU session according to the indication parameter. The embodiment of the present application can implement that the SMF can implement the downlink number when the PDU session is not modified. It is discarded, so that it is no longer necessary to page the terminal, saving signaling.

In a sixth aspect, a session management method is provided. The SMF has a PDU session accessing the LADN, the method includes: the AMF receives the first service request invoked by the SMF, and the first service request is used by the SMF to request the AMF to send a message or information to the access node AN; When the service area of the LADN is not included in the registration area of the terminal, the AMF sends an indication parameter to the SMF, where the indication parameter is used to indicate that the LADN is not included in the registration area. The indication parameter may specifically include a LADN DNN and an indication, the indication being used to indicate that the registration area does not include information of the LADN. The embodiment of the present application can implement that when the SMF does not modify the PDU session, the downlink data can be discarded, so that the terminal does not need to be paged again, and signaling is saved.

In a seventh aspect, a terminal is provided having the functionality to implement terminal behavior in the first aspect described above and its alternative implementation. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above. With the PDU session accessing the LADN, when the terminal enters the registration area that does not support the LADN, the terminal modifies or releases the PDU session, thereby reducing the network device's downlink data due to the PDU session of the access LADN. Signaling waste caused by the arrival of the paging terminal. The PDU session can also be managed based on the current registration area and the service area of the LADN, with a fine granularity. It is solved that when the terminal is located outside the service area of the LADN, the terminal initiates the release of the PDU session, thereby reducing the signaling waste caused by the paging terminal when the PDU session exists, but the terminal is not in the service area of the LADN. After the PDU session is modified or released on the network side, the terminal can be notified, so that the terminal can modify or release the PDU session synchronously, thereby reducing the existence of the PDU session, but the terminal is not in the service area of the LADN, and the paging terminal is caused by the paging terminal. Signaling is wasted. By marking the PDU session, the terminal can count the number of times the terminal continuously enters the registration area of the service area that does not include the LADN, thereby setting a rule. When the registration area of the service area that does not include the LADN is continuously less than or equal to the set number of times, The terminal modifies the PDU session. When the set number of times is reached or exceeded, the terminal releases the PDU session, and the management granularity of the PDU session accessing the LADN is finer. When the terminal re-enters the RA of the service area including the LADN, the PDU session of the access LADN is re-enabled for data transmission, thereby managing the PDU session from a finer granularity, and causing the network device to page the terminal more Reasonable, saving signaling and improving efficiency.

In an eighth aspect, there is provided an SMF entity having the functionality to implement the SMF entity behavior in the second aspect above and its alternative implementation. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above. Through the embodiment of the present application, the PDU session is managed based on the current registration area and the service area of the LADN, and the granularity is fine. When the terminal re-enters the RA of the service area including the LADN, the PDU session of the access LADN is re-enabled for data transmission, thereby managing the PDU session from a finer granularity, and causing the network device to page the terminal more Reasonable, saving signaling and improving efficiency.

In a ninth aspect, there is provided an SMF entity having a function of implementing the SMF entity behavior in the third aspect described above and optionally in the implementation or in the fifth aspect. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above. With the embodiment of the present application, the AMF notifies the SMF that the RA that the terminal moves to includes the change notification of the service area of the LADN, and the release or modification of the LADN session is initiated by the SMF, thereby reducing the network device's downlink data due to the PDU session of the access LADN. Signaling waste caused by the arrival of the paging terminal. The SMF may notify the change of the service area of the RA including the LADN by the AMF subscription terminal, and the AMF notifies the SMF when the condition is satisfied. Or, When the SMF does not modify the PDU session, the downlink data can be discarded, so that the terminal does not have to be paged again, and signaling is saved.

In a tenth aspect, there is provided an AMF entity having the functionality to implement the AMF entity behavior of the fourth aspect described above and its alternative implementation or sixth aspect. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above. With the embodiment of the present application, the AMF notifies the SMF that the RA that the terminal moves to includes the change notification of the service area of the LADN, and the release or modification of the LADN session is initiated by the SMF, thereby reducing the network device's downlink data due to the PDU session of the access LADN. Signaling waste caused by the arrival of the paging terminal. The SMF may notify the change of the service area of the RA including the LADN by the AMF subscription terminal, and the AMF notifies the SMF when the condition is satisfied. Alternatively, the SMF can discard the downlink data when the PDU session is not modified, thereby eliminating the need to page the terminal and saving signaling.

According to an eleventh aspect, a computer readable storage medium storing a computer program, the computer program being executed by a processor, implements the first aspect, the second aspect, the third aspect, and the The method of any one or more of the four aspects, the fifth aspect, and the sixth aspect.

According to a twelfth aspect, a computer program product comprising instructions for causing a computer to perform the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, and The method of any one or more of the sixth aspects.

The embodiment of the present application can be implemented. For a LADN session, when the terminal enters the registration area that does not support the LADN, the terminal modifies or releases the PDU session, thereby reducing the network device's downlink data arrival due to the PDU session of the access LADN. The signaling caused by the paging terminal is wasted. The PDU session can also be managed based on the current registration area and the service area of the LADN, with a fine granularity. It is solved that when the terminal is located outside the service area of the LADN, the terminal initiates the release of the PDU session, thereby reducing the signaling waste caused by the paging terminal when the PDU session exists, but the terminal is not in the service area of the LADN.

DRAWINGS

1 is a schematic structural diagram of a 5G communication network;

2 is a schematic diagram of a service area of a LADN.

FIG. 3 is a schematic diagram of signaling interaction of a method for session management according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of signaling interaction of another method for session management according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of signaling interaction of another method for session management according to an embodiment of the present disclosure;

FIG. 6 is an example provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of signaling interaction of a method for service subscription according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of signaling interaction of another method for session management according to an embodiment of the present disclosure;

FIG. 9 is a schematic diagram of signaling interaction of another method for session management according to an embodiment of the present disclosure;

FIG. 10 is another example provided by an embodiment of the present application;

FIG. 11 is a schematic structural diagram of a terminal according to an embodiment of the present application;

FIG. 12 is a schematic structural diagram of an SMF according to an embodiment of the present disclosure;

FIG. 13 is a schematic structural diagram of another SMF according to an embodiment of the present disclosure;

FIG. 14 is a schematic structural diagram of an AMF according to an embodiment of the present disclosure;

15 is a schematic structural diagram of another SMF provided by an embodiment of the present application;

FIG. 16 is a schematic structural diagram of another AMF according to an embodiment of the present disclosure;

FIG. 17 is a schematic structural diagram of another terminal according to an embodiment of the present disclosure;

FIG. 18 is a schematic structural diagram of another SMF according to an embodiment of the present disclosure;

FIG. 19 is a schematic structural diagram of another SMF according to an embodiment of the present disclosure;

FIG. 20 is a schematic structural diagram of another AMF according to an embodiment of the present disclosure;

FIG. 21 is a schematic structural diagram of another SMF according to an embodiment of the present disclosure;

FIG. 22 is a schematic structural diagram of another AMF according to an embodiment of the present disclosure.

Detailed ways

The embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application.

The embodiment of the present application provides a method and a device for session management, which are applied to a 5G communication network.

In the embodiment of the present application, a terminal may also be referred to as a user equipment, and may be a device that provides voice and/or data connectivity to a user, a handheld device with a wireless connection function, or is connected to a wireless device. Other processing devices for the modem. The wireless terminal can communicate with one or more core networks via a Radio Access Network (RAN), which can be a mobile terminal, such as a mobile phone (or "cellular" phone) and with a mobile terminal device. The computer, for example, can be a portable, pocket, handheld, computer built-in or in-vehicle mobile device that exchanges language and/or data with the wireless access network. For example, personal communication service (PCS) telephone, cordless telephone, session initiated protocol (SIP) telephone, wireless local loop (WLL) station, personal digital assistant (personal digital assistant, PDA) and other equipment. A wireless terminal may also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, an access point, a remote terminal, an access terminal, a user terminal, a user agent, a user device, or a terminal device, in the embodiment of the present application Not limited. According to the service type, the terminal involved in the embodiment of the present invention may be a terminal device with high requirements for speed and mobility, such as a mobile phone, a multimedia device, or the like, or a terminal of the Internet of Things, or a car network. Terminal.

FIG. 1 is a schematic structural diagram of a 5G communication network according to an embodiment of the present application.

As shown in FIG. 1, an authentication service function (AUSF), an AMF, an SMF, a unified data management (UDM), an application function entity (AF), and a policy control function entity ( The policy control function (PCF) and the UPF may be one or more servers in the core network of the 5G communication network. The terminal can realize network interconnection by accessing the communication network. For example, a PDU session can be established through the access communication network to perform data transmission with the UPF, and the PDU session can be managed by the SMF.

The function of each module in the 5G communication network is briefly introduced below.

AUSF is primarily used for authentication.

The AMF has terminal mobility management, registration management, connection management, lawful interception, support for session management (SM) information between the transmission terminal and the SMF, access authentication and access authorization. The AMF Information such as TA, RA, and LADN of the terminal can be determined.

SMF has functions such as session management and roaming. Among them, session management functions, for example, session establishment, modification, and release, include tunnel maintenance of UPF and access network (AN) nodes. The roaming function may include charging data collection, and signaling transmission supporting authentication/authorization with an external data network (DN). For example, the SMF can be used to manage a PDU session accessing the LADN, including modifying or releasing a PDU session accessing the LADN, receiving a DDN corresponding to the PDU session accessing the LADN, and the like.

UPF has functions such as packet routing and lawful interception. The UPF can route and legally listen to packets corresponding to the PDU session accessing the LADN.

UDM has the functions of authentication certificate processing, user identification processing, access authorization, registration and mobility management, subscription management, and SMS management.

The AF can interact with the 3GPP core network.

The PCF is able to support policy frameworks as well as policy rules.

The interface between the entities can be specifically referred to the 3GPP standard. It should be noted that the 5G communication network structure shown in FIG. 1 is merely an example, and the 5G communication network structure used in the embodiment of the present invention may include more or less network devices.

The applicant of the present application finds that the LADN in the 5G network has a certain relationship with the RA. The tracking area (TA) in the RA can support the LADN in whole or in part, or the TA in the RA can all not support. LADN. When the TA in the RA supports all or part of the LADN, that is, when the LADN Service Area and the Registration Area have an intersection, the RA is considered to include the service area of the LADN. When all the TAs in the RA do not support the LADN, that is, when the LADN Servcie Area has no intersection with the RA, the service area of the LADN is not included in the RA.

It can be understood that the TA supporting the LADN means that when the terminal is within the coverage of the TA, the PDU session accessing the LADN can be established through the base station under the TA and data transmission is performed on the PDU session of the LADN. The TA does not support LADN. When the terminal is in the coverage of the TA, the PDU session to the LADN cannot be established. For the PDU session of the established LADN, the corresponding user plane connection cannot be activated for data transmission.

For example, as shown in FIG. 2, FIG. 2 is a schematic diagram of a service area of a LADN. TA1-TA16 constitutes four RAs (RA1-RA4), of which TA1-TA5 supports LADN. At this time, all the TAs in RA1 support LADN, and it is considered that the RA1 includes the service area of LADN; if the TA in RA2 only supports LADN by TA5, it is considered that the service area of LADN is included in RA1; all TAs in RA3 and RA4 are not If LADN is supported, it is considered that the service areas of LADN are not included in RA3 and RA4.

The embodiments of the present application are further described below with reference to the accompanying drawings.

FIG. 3 is a schematic diagram of signaling interaction of a method for session management according to an embodiment of the present disclosure. The terminal has a PDU session accessing the LADN.

The PDU session in which the terminal accesses the LADN may be used by the terminal to save the context of the PDU session in which the LADN is accessed. The context of the PDU session may include one or more of the following: an identifier of the PDU session; an SSC of the PDU session. Mode; type of PDU session (eg IP type), ethernet type, unstructured type, etc.; DNN corresponding to PDU session; network slice information corresponding to PDU session, such as S-NSSAI, network slice identifier ( NSI), etc.; QFI of the PDU session, QoS parameters corresponding to the QoS flow (eg 5QI), GFBR, MFBR, Session-AMBR, radio bearer information corresponding to the PDU session, such as DRB, may also refer to The UE establishes a PDU session with access to the LADN, and the terminal can transmit uplink and downlink data through the PDU session. Specifically, the PDU session accessing the LAND means that the DNN attribute corresponding to the PDU session is the LADN DNN.

As shown in FIG. 3, the method specifically includes:

S310. The terminal receives the first message sent by the AMF. The AMF registered by the terminal sends the LADN information in the registration area where the terminal is located to the terminal through the first message. The LADN information includes the LADN DNN and the LADN Service Area. Of course, the LADN information sent to the terminal is a set of LADN information corresponding to the LADN of the terminal subscription. If the terminal subscribes to multiple LADNs, the LADN information corresponding to multiple LADNs is sent to the terminal. The first message may carry the LADN information when the registration area RA where the terminal is located supports the LADN information. For example, the information of the LADN may be the LADN available information (LADN availability info). For example, the first message may be a registration accept message, the registration accept message includes information of the LADN; or the first message may be a UE configuration update command message, the terminal configuration update command message includes LADN information and more. The terminal performs the registration process, and the AMF sends a registration accept message to the terminal.

When the registration area where the terminal is located does not support the LADN information, the first message may not carry the LADN information.

In the example of a LADN message, the LADN information includes the LADN data network name (LADN DNN) and the LADN service area (LADN service area). The LADN service area may refer to the TA set of the LADN.

Wherein, a plurality of LADNs may be included in the 5G network, and the multiple LADNs are not always available to the terminal. The LADN information received by the terminal includes the LADN DNN of the LADN that the terminal can access, and the corresponding LADN service area.

Specifically, the AMF saves the service area of the LADN available to the terminal, and the AMF can determine whether the current RA of the terminal includes the LADN according to the current RA of the terminal and the service area of the LADN available to the terminal, that is, the current RA of the terminal and the terminal. Whether the service areas of the available LADNs overlap. When the current RA of the terminal includes the information of the LADN, that is, the current RA of the terminal overlaps with the service area of the LADN available to the terminal, the first message may carry the LADN information, where the LADN information indicates the LADN included in the current RA ( LADN DNN) and the service area of the LADN; when the current RA of the terminal does not include the LADN information, that is, the current RA of the terminal does not overlap with the service area of the LADN available to the terminal, the first message may not carry the LADN information. .

As an example, as shown in FIG. 2, TA1-TA5 belong to the service area of the LADN available to the terminal. If the current RA of the terminal is RA1, since RA1 includes TA1-TA4, the information of the LADN may be carried in the first message. If the current RA of the terminal is RA3, since the RA3 does not overlap with the service area of the LADN available to the terminal, the information of the LADN may not be carried in the first message. If the current RA of the terminal is RA2, since RA2 includes TA5, the information of the LADN may be carried in the first message.

S320. The terminal determines that the LADN information is not included in the first message.

After receiving the first message, the terminal may determine, according to the first message, that the state of the LADN in the registration area changes, thereby triggering modification or release of the PDU session accessing the LADN.

Specifically, when the first message received by the terminal does not include the information of the LADN, the terminal determines that the information of the LADN is not included in the first RA, and further, the terminal determines that before receiving the first message. When the information of the LADN is included in the first RA, that is, the terminal currently stores information of the LADN, and the terminal determines the The available state of the LADN within the RA changes, thereby triggering modification or release of a PDU session accessing the LADN, the first RA being the current RA of the terminal.

In another scenario, when the first message received by the terminal does not include the information of the LADN, the terminal determines that the information of the LADN is not included in the first RA, and further, the terminal determines that the second RA includes When the information of the LADN, that is, the terminal currently holds the information of the LADN, the terminal determines that the available state of the LADN in the RA changes. The first RA is the current RA of the terminal, and the second RA is the RA before the terminal enters the first RA.

In another embodiment, the terminal may determine whether the preset condition is reached according to the first message, and if so, release the PDU session accessing the LADN. If not, modify the PDU session accessing the LADN.

For example, the preset condition may be the number of times the terminal continuously is in an RA that does not support LADN. That is, the number of times the current RA of the terminal does not include the LADN information continuously. For example, when the terminal is in the RA that does not support LADN for the first time, the PDU session accessing the LADN can be marked as unavailable. Then, when the terminal is in the RA for the second time in a row, the terminal determines that the PDU session accessing the LADN has been marked as unavailable, and then releases the PDU session of the access LADN. Among them, unavailable can include a suspended state.

For modifying the PDU session accessing the LADN, as shown in FIG. 3, the S330-S360 may be specifically included:

S330. The terminal sends a first session modification request message (PDU session Modification request) to the SMF. The first session modification request message includes a first indication, and the first indication may be used to indicate that the current RA does not include LADN information (no LADN available info indication in current RA). The LADN information includes at least one of a LADN DNN and a LADN Service Area.

The terminal also needs to send a PDU session identifier to the SMF. The PDU session identifier may be included in the first session modification request message, or may be included in the NAS message sent by the terminal to the AMF, and the MF session ID is sent by the AMF to the SMF. The PDU session ID identifies the PDU session for which the terminal accesses the LADN.

S340. The SMF modifies the PDU session accessing the LADN according to the first session modification request message.

The SMF modifies the PDU session accessing the LADN according to the first session modification request message, including one or more of the following:

The SMF instructs the UPF to set the gating corresponding to the PDU session accessing the LADN to be closed. For example, the SMF may send a door close command (GATE OFF) to the PDU;

The SMF notifies the UPF to stop sending the DDN associated with the PDU session accessing the LADN;

The SMF notifies the UPF to discard the downlink data corresponding to the PDU session accessing the LADN;

The SMF marks the PDU session accessing the LADN as unavailable or suspended. Among them, the unavailable or suspended state includes one or more of the following:

The user plane connection of the PDU session does not exist;

The SMF cannot trigger a user plane connection that activates the PDU session;

The SMF cannot accept the user plane connection request for the active PDU session requested by the terminal.

In addition, after receiving the first session modification request message, the SMF may determine whether the status of the PDU session corresponding to the first session modification request message is in an available state, for example, the PDU session corresponding to the first session modification request message is unavailable. Or the suspended state indicates that the PDU session is unavailable before receiving the first session modification request message. In this case, the PDU session can be directly released, that is, the context of the PDU session is deleted. If the PDU session corresponding to the first session modification request message is in an available state, the PDU session is available before receiving the first session modification request message. At this time, after receiving the first session modification request message, the PDU is received. Session marked as unavailable Or suspend state. The available status of the PDU session includes one or more of the following:

The user plane connection of the PDU session exists;

The SMF can trigger a user plane connection that activates the PDU session;

The SMF can accept the user plane connection request of the activated PDU session requested by the terminal;

The SMF can send messages about the PDU session to other network elements.

S350. The SMF sends a first session modification command message (PDU session modification command) to the terminal. The first session modification command message includes an identifier of the PDU session and a first parameter, and the first parameter may be used to indicate that the PDU session is unavailable or suspended.

The SMF may also instruct the terminal to mark the PDU session as unavailable or suspended after marking the PDU session as unavailable or suspended.

S360, the terminal marks the PDU session as unavailable or suspended.

The terminal marks the PDU session accessing the LADN as unavailable or suspended.

In another implementation, the terminal may also save a record that has sent the first indication to the SMF. For the PDU session, if the terminal has a record that has sent the first indication to the SMF, it may indicate that the PDU session is marked as unavailable.

Among them, S350 and S360 are optional steps. For example, the process of marking the PDU session as unavailable by the terminal may also be performed locally by the terminal. At this time, the terminal may perform before receiving the first session modification command message, or the SMF does not need to send the first session modification command message.

Through S360, the terminal can also achieve statistics on the number of consecutive consecutive RAs that do not support LADN. Further, the rule may be set, in a case where the registration area of the service area that does not include the LADN is continuously less than or equal to the set number of times, the terminal modifies the PDU session, and when the set number of times is reached or exceeded, the terminal releases the In the PDU session, the management granularity of the PDU session accessing the LADN is finer.

Therefore, after modifying or releasing the PDU session on the network side, the terminal is notified, so that the terminal synchronizes modification or release of the PDU session, thereby reducing paging due to the existence of the PDU session, but the terminal is not in the service area of the LADN. Signaling waste caused by the terminal. .

In the case where the PDU session accessing the LADN is marked as unavailable, when the terminal determines to re-enter the RA supporting the LADN, the terminal may also mark the PDU session accessing the LADN as available. FIG. 4 is a schematic diagram of signaling interaction of another method for session management according to an embodiment of the present disclosure. As shown in FIG. 4, specifically, S410-S460 may be included:

S410. The terminal receives the second message sent by the AMF.

The AMF also determines whether the current RA of the terminal includes the LADN information according to the current RA of the terminal and the service area of the LADN available to the terminal. When the current RA of the terminal includes the information of the LADN, the second message may carry the information of the LADN, where the information of the LADN indicates the service area of the LADN and the LADN included in the current RA; when the current RA of the terminal does not include the information of the LADN, the The second message may not carry the LADN information. The second message may be a registration accept message, or the terminal configures an update command message. For example, the LADN information can be the available information for the LADN.

As an example, as shown in FIG. 2, TA1-TA5 belong to the service area of the LADN available to the terminal. If the current RA of the terminal is RA1, since RA1 includes TA1-TA4, the information of the LADN may be carried in the second message. If the current RA of the terminal is RA3, since the RA3 does not overlap with the service area of the LADN available to the terminal, the information of the LADN may not be carried in the second message. If the current RA of the terminal is RA2, due to RA2 includes TA5, then the second message can carry the LADN information.

S420. The terminal determines information that includes the LADN in the second message.

After receiving the second message, the terminal may determine that the available state of the LADN changes according to the change of the available state of the information LADN carried in the second message. Thereby triggering a modification of the PDU session accessing the LADN.

Specifically, when the first message received by the terminal includes the LADN information, the terminal determines that the first RA includes the LADN information, and further, the terminal is in the first RA before receiving the second message. When the information of the LADN is not included, that is, the terminal does not currently have the LADN information, the terminal determines that the available state of the LADN changes; or

When the second information includes the information of the LADN, and the information of the LADN is not included in the second RA, that is, the terminal does not currently have the LADN information, the terminal determines that the available state of the LADN changes;

The first RA is a current registration area of the terminal, and the second RA is an RA before the terminal enters the first RA.

S430. The terminal sends a second session modification request message (PDU session Modification request) to the SMF. The second session modification request message includes a second indication, which may be used to indicate that the current RA includes LADN information (no LADN available info indication in current RA).

The terminal also needs to send the identifier of the PDU session to the SMF. The identifier of the PDU session may be included in the second session modification request message, or may be included in the NAS message sent by the terminal to the AMF, and sent by the AMF to the SMF, the PDU session. The ID identifies the PDU session that the terminal accesses the LADN.

S440. The SMF modifies the PDU session accessing the LADN according to the second session modification request message.

The SMF modifies the PDU session accessing the LADN according to the second session modification request message, including one or more of the following:

The SMF instructs the UPF to set the gating corresponding to the PDU session of the access LADN to be on, for example, the SMF may send a door open command (GATE ON) to the PDU;

The SMF notifies the UPF to send a DDN related to the PDU session accessing the LADN;

The SMF notifies the UPF to send downlink data corresponding to the PDU session accessing the LADN;

The SMF marks the PDU session accessing the LADN as available.

In addition, after receiving the second session modification request message, the SMF may determine whether the state of the PDU session corresponding to the second session modification request message is in an available state, for example, the PDU session corresponding to the second session modification request message is unavailable. Then, the PDU session is unavailable before receiving the second session modification request message, and the PDU session can be marked as available at this time. If the PDU session corresponding to the second session modification request message is in a configurable state, the PDU session is available before receiving the second session modification request message. In this case, no modification is possible.

S450. The SMF sends a second session modification command message (PDU session modification command) to the terminal. The second session modification command message includes an identifier of the PDU session and a second parameter, the second parameter is used to indicate that the PDU session is available.

The SMF may also instruct the terminal to mark the PDU session as available after marking the PDU session as available.

S460. The terminal marks the PDU session as available.

The terminal marks the PDU session accessing the LADN as available.

Among them, S450 and S460 are optional steps. For example, the process of the terminal marking the PDU session as an available state may also be performed locally by the terminal. In this case, before the second session modification command message is received, after the information of the LADN is included in the second message, the SMF does not need to be sent. The second session modifies the command message.

Therefore, when the terminal re-enters the RA of the service area including the LADN, the PDU session of the access LADN is re-enabled for data transmission, thereby managing the PDU session from a finer granularity, and causing the network device to The paging of the terminal is more reasonable, saving signaling and improving efficiency.

FIG. 5 is a schematic diagram of signaling interaction of another method for session management according to an embodiment of the present disclosure. As shown in FIG. 5, for releasing the LADN related PDU session that has already been established, the S510-S520 may be specifically included:

S510. The terminal sends a session release message to the SMF. The session release message may include a PDU session ID indicating a PDU session in which the terminal accesses the LADN.

S520. The SMF releases the PDU session accessing the LADN according to the session release message.

FIG. 6 is an example provided by an embodiment of the present application. The terminal has a PDU session accessing the LADN. As shown in FIG. 6, the method includes:

S601. The terminal performs a registration procedure (Mobility Registration procedure), and receives a registration accept message sent by the AMF.

S602. When the registration accept message received by the terminal does not include the information of the LADN, the terminal determines that the available state of the LADN changes, thereby triggering a modification process of the LADN PDU session. For example, the LADN information can be the available information for the LADN.

Specifically, the terminal determines that the available state of the LADN changes as in the method in step S320. The registration accept message in the flow is equivalent to the first message in S320.

S603. The terminal sends a PDU session modification request message to the AMF. The PDU session modification request message includes indication information (no LADN available info indication) without the availability information of the LADN, and the indication information of the availability information without the LADN is used to indicate that the current RA does not include the LADN service area.

S604. The AMF sends a PDU session modification request message to the SMF by calling a request of the SMF service.

S605. The SMF determines whether the PDU session accessing the LADN is in a suspended state.

If yes, S612 is directly executed to release the PDU session; if not, S606-S611 is performed.

S606. The SMF marks the status of the PDU session accessing the LADN as a suspended state according to the PDU session modification request message.

S607. The SMF sends a response to the AMF that invokes the SMF service, where the response to the SMF service includes a PDU session modification command message. The PDU session modification command message includes a session suspension parameter, and the parameter is used to instruct the terminal to mark the PDU session as a suspended state.

S608. The AMF sends a PDU session modification command message to the terminal.

After modifying or releasing the PDU session on the network side, the terminal may be notified, so that the terminal can modify or release the PDU session synchronously, thereby reducing the message caused by the paging terminal when the terminal is not in the service area of the LADN due to the existence of the PDU session. Make a waste.

S609. The terminal marks the PDU session accessing the LADN as a suspended state.

Or, in another implementation, the terminal may save an indication that the information of the LADN has not been sent to the SMF. Record of information. After the terminal re-enters the RA including the LADN service area, the PDU session modification process is initiated again to notify the SMF that the terminal re-enters the RA including the LADN service area.

By marking the PDU session, the terminal can count the number of times the terminal continuously enters the registration area of the service area that does not include the LADN, thereby setting a rule. When the registration area of the service area that does not include the LADN is continuously less than or equal to the set number of times, The terminal modifies the PDU session. When the set number of times is reached or exceeded, the terminal releases the PDU session, and the management granularity of the PDU session accessing the LADN is finer.

S610. The SMF sends a session modification request message to the UPF. The session modification request message can be sent through the N4 interface.

The session modification request message carries an indication that the gating is set to be off (GATE OFF), or notifies the UPF to stop sending a Downlink Data Notification (DNN) related to the PDU session accessing the LADN, and discards the corresponding downlink data.

S611. The UPF sends a session modification response to the SMF. The UPF may set the gating of the data flow corresponding to the PDU session to the closed state, or stop sending the DDN related to the PDU session accessing the LADN, and discard the corresponding data.

When the terminal re-enters the RA of the service area including the LADN, the PDU session of the access LADN is re-enabled for data transmission, thereby managing the PDU session from a finer granularity, and causing the network device to page the terminal more Reasonable, saving signaling and improving efficiency.

FIG. 7 is a schematic diagram of signaling interaction of a method for service subscription according to an embodiment of the present disclosure. The terminal has a PDU session that accesses the LADN. As shown in FIG. 7, the method specifically includes:

S710. The SMF subscribes to the AMF notification service. For example, the SMF sends a subscription notification service request to the AMF, that is, the SMF invokes the subscription notification service provided by the AMF to implement the SMF subscription notification service to the AMF. The notification service is used to notify the SMF when the preset event occurs, wherein the preset event is a change in the available state of the LADN, and the change in the available state of the LADN may change the available state of the LADN in the registration area.

When the SMF subscribes to the AMF to notify the service, the SMF may send the LADN's data network name (LADN DNN) and a preset event to the AMF to subscribe to the AMF subscription service. Of course, the SMF can also send a filter to the AMF about the preset event, so that the AMF can determine the occurrence of the preset event through the filter. In addition, the SMF can also send other parameters to the AMF that can identify the occurrence of the preset event. No specific restrictions are imposed.

The preset event is a change of the available state of the LADN. Specifically, the registration area may be converted between the LADN information and the LADN information, including one or more of the following:

The terminal enters the second RA that does not include the information of the LADN by the first RA including the information of the LADN;

The terminal enters the second RA including the information of the LADN by the first RA that does not include the information of the LADN;

The terminal does not replace the RA, but the LADN available for the terminal is changed, so that the first RA of the terminal is changed from the information including the LADN to the information not including the LADN;

The terminal does not replace the RA, but the LADN available for the terminal is changed, so that the first RA of the terminal is changed from the information not including the LADN to the information including the LADN.

The first RA is the current RA of the terminal, and the second RA is the RA before the terminal enters the first RA. The LADN information can be the available information for the LADN.

For example, as shown in FIG. 2, TA1-TA5 belong to the service area of the LADN available to the terminal. When the current registration area of the terminal is moved from RA1 (or RA2) to RA3, or from RA2 to RA4, that is, the terminal is The RA including the information of the LADN is moved to the RA that does not include the information of the LADN, and the registration area that the terminal enters is considered to change between the information including and not including the LADN, and vice versa.

For another example, as shown in FIG. 2, TA1-TA5 belong to a service area for the LADN available to the terminal. When the network side cancels the LADN service by TA1-TA5, if the current registration area of the terminal is RA1, the RA of the terminal is changed from the information including the LADN to the information that does not include the LADN, and the registration area that the terminal enters is considered to be included and not. There is a change between the information including LADN. When the network side sets the TA10 to support the LADN, and the TA10 belongs to the service area of the LADN available to the terminal, if the current registration area of the terminal is RA3, the RA of the terminal becomes information including the LADN by the information not including the LADN. The registration area that the terminal enters is considered to change between information including and not including the LADN.

At S720, the AMF determines that the available state of the LADN has changed.

The AMF determines whether the current RA of the terminal includes the LADN information according to the change of the RA of the terminal and the change of the service area of the LADN available to the terminal, and determines whether the information of the LADN in the registration area entered by the terminal changes or is the same. Under the registration area, whether there is a change between the information including the LADN and the information not including the LADN, that is, whether the available state of the LADN has changed.

S730. The AMF sends a notification message to the SMF, where the notification information is used to notify the SMF that the preset event occurs. The notification information may include: a LADN DNN and/or an indication parameter, the LADN DNN is used to identify the LADN, and the indication parameter is used to indicate that a preset event of the SMF subscription occurs, and specifically, the RA of the terminal may include or not include the information of the LADN. (LADN available/unavailable indication in current RA), or a parameter indicating that the RA of the terminal converts between the information including the LADN and the information not including the LADN, or other parameters for indicating the change of the preset event, The invention is not specifically limited.

Specifically, the AMF sends the registration area of the terminal to the SMF including LAND information, which means that the registration area of the terminal is converted from information not including the LADN to the information including the LADN. If sent to the SMF, the registration area of the terminal does not include the information available to the LADN, which means that the registration area of the terminal is converted from information including the LADN to information not including the LADN. Of course, the AMF may also send other parameters to the SMF to indicate that the registration area of the terminal transitions between including the LADN information and not including the LADN information.

For example, when the AMF determines that the terminal enters the first registration area of the information including the LADN from the second registration area including the LADN, when the terminal registers with the first registration area, the AMF sends a notification message to the SMF, the notification message is not Includes information about LADN.

Alternatively, when the AMF determines that the terminal enters the first registration area including the information of the LADN by the second registration area that does not include the information of the LADN, when the terminal registers with the first registration area, the AMF sends a notification message to the SMF, the notification message including LADN information.

Or, when the AMF determines that the registration area of the terminal is the first registration area, and the first registration area is reconfigured to include the information of the LADN by the information including the LADN, the AMF sends a notification message to the SMF, where the notification message does not include the LADN. information.

Or, when the AMF determines that the registration area of the terminal is the first registration area, the first registration area is not including the LADN. When the information is reconfigured to include the LADN information, the AMF sends a notification message to the SMF, the notification message including the LADN information.

For another example, as shown in FIG. 2, when the current registration area of the terminal is moved from RA1 (or RA2) to RA3, or from RA2 to RA4, that is, the terminal is moved from the RA including the information of the LADN to the LA that does not include the LADN. RA of the information, at this time, the AMF sends the notification information of the information that the terminal RA does not include the LADN to the SMF. When the current registration area of the terminal is moved from RA3 to RA1 (or RA2), or from RA4 to RA2, that is, the terminal moves from the RA that does not include the information of the LADN to the RA including the information of the LADN, at this time, the AMF The SMF sends the notification information of the current RA of the terminal including the LADN information.

S740. The SMF modifies or releases the PDU session according to the notification information.

After receiving the notification information and determining that the available state of the LADN has changed, the SMF may modify or release the PDU session accessing the LADN.

If the PDU session accessing the LADN is unavailable, after the SMF receives the notification information that the current RA includes the LADN information, the PDU session that accesses the LADN is modified to be in an available state. Further, the SMF may also perform one or more of the following steps: notifying the UPF to set the gating corresponding to the PDU session accessing the LADN to ON; notifying the UPF to send the DDN related to the PDU session accessing the LADN; notifying the UPF to send Downlink data related to the PDU session accessing the LADN.

If the PDU session accessing the LADN is in an available state, after the SMF receives the notification information that the current RA does not include the LADN information, the PDU session of the access LADN is modified to be unavailable. Further, the SMF may perform the following one. Item or multiple steps: notifying the UPF that the gating corresponding to the PDU session accessing the LADN is set to OFF; notifying the UPF to stop transmitting the DDN associated with the PDU session accessing the LADN; notifying the UPF to discard the PDU session associated with accessing the LADN Downstream data.

In another possible implementation, after the SMF receives the notification information that the current RA does not include the LADN information, the SMF may also release the PDU session accessing the LADN. For example, if the PDU session accessing the LADN is in an available state, after the SMF receives the notification information that the current RA does not include the LADN information, the PDU session that accesses the LADN is released.

In another possible implementation, when the SMF acquires the registration information of the terminal when the downlink data arrives, the AMF sends the notification information of the information that the current RA does not include the LADN to the SMF, and the SMF may also perform the following. One or more steps: notifying the UPF to discard the downlink data; notifying the UPF to set the gating corresponding to the PDU session accessing the LADN to off; notifying the UPF to stop transmitting the DDN associated with the PDU session accessing the LADN; The LADN PDU session is modified to be unavailable. When the SMF does not modify the PDU session, the downlink data can be discarded, so that the terminal does not have to be paged again, and signaling is saved.

It can be implemented by the embodiment of the present application that the AMF notifies the SMF that when the RA moved by the terminal transitions between the service area including the LADN and the service area not including the LADN, the release or modification of the LADN session is initiated by the SMF, thereby reducing When the terminal is in an RA that does not support LADN, the network device wastes signaling caused by paging the terminal because the downlink data arrives in the PDU session of the access LADN.

FIG. 8 is a schematic diagram of signaling interaction of another method for session management according to an embodiment of the present disclosure. The terminal has a PDU session that accesses the LADN. As shown in FIG. 8, the method specifically includes:

S810. The terminal receives the first message sent by the AMF in the first RA. The first message includes or does not include information of the LADN (for example, the first message shown in conjunction with FIG. 8 may be the first message shown in conjunction with FIG. 3 or In conjunction with the second message shown in FIG. 4, the first RA is the current registration area of the terminal.

The first message may be a registration accept message or a terminal configuration update command message.

For example, when the AMF determines that the terminal enters the first registration area by the second registration area, if the first registration area includes the information of the LADN, the AMF sends a registration accept message to the terminal, where the registration acceptance message includes the LADN information, if the first registration If the area does not include the LADN information, the AMF sends a registration accept message to the terminal, and the registration accept message does not include the LADN information.

It can be understood that the LADN information is not included in the registration accept message, and may be no LADN information, or the LADN information is empty, or other indication information indicates that there is no LADN information.

Alternatively, when the AMF determines that the terminal enters the first registration area that does not include the information of the LADN by the second registration area including the information of the LADN, when the terminal registers with the first registration area, the AMF sends a registration accept message to the terminal, and the registration is received. The message does not include information about LADN.

Alternatively, when the AMF determines that the terminal enters the first registration area including the information of the LADN by the second registration area that does not include the information of the LADN, when the terminal registers with the first registration area, the AMF sends a registration accept message to the terminal, and the registration is received. The message includes information about LADN.

Alternatively, when the AMF determines that the registration area of the terminal is the first registration area, and the first registration area is reconfigured to include the information of the LADN by the information including the LADN, the AMF sends a terminal configuration update command message to the terminal, and the terminal configuration update is performed. The command message does not include information about the LADN.

Alternatively, when the AMF determines that the registration area of the terminal is the first registration area, and the first registration area is reconfigured to include the LADN information by the information not including the LADN, the AMF sends a terminal configuration update command message to the terminal, and the terminal configuration update is performed. The command message includes information about the LADN.

In the embodiment of the present application, the first registration area is the current registration area of the terminal, and the second registration area is the registration area before the terminal enters the current registration area.

The information about the LADN can be referred to the related description in S310 in the embodiment shown in FIG. 3, and details are not described herein again.

S820. The terminal determines, according to the first message, that an available state of the LADN changes.

The change in the available state of the LADN includes that the registration area is changed from information including the LADN to information not including the LADN, or the registration area is changed from information not including the LADN to information including the LADN.

For example, when the first message does not include the information of the LADN, indicating that the current registration area does not include the information of the LADN and the second registration area includes the information of the LADN, the terminal determines that the available state of the LADN changes; or, when the first message includes the LADN The information indicates that the current registration area includes the LADN information, and the terminal determines that the available state of the LADN changes when the second registration area does not include the LADN information.

The information that the second registration area includes or does not include the LADN may be determined according to the second message that is received by the terminal when the second registration area is received. The second message includes or does not include information of the LADN. The second message includes information of the LADN, indicating that the second registration area includes information of the LADN; the second message does not include information of the LADN, indicating that the second registration area does not include information of the LADN. The second message may be a registration accept message or a terminal configuration update command message. The second message received by the terminal in the second registration area may be recorded, or the second registration area may be recorded with or without LADN information. When the terminal receives the first message, the second registration area may be directly determined according to the record. Or do not include information about LADN.

In addition, the second registration area includes or does not include information of the LADN, and may also be based on when the first message is received. The status of the PDU session in which the terminal accesses the LADN is determined. For example, when the first message is received, the status of the PDU session in which the terminal accesses the LADN is unavailable, indicating that the second registration area does not include the LADN information; when the first message is received, the terminal accesses the LADN PDU session. The status is available, indicating that the second registration area includes information about the LADN.

For another example, when the first message does not include the information of the LADN, and the terminal includes the information of the LADN before the first message is received in the first registration area, the terminal determines that the available state of the LADN changes; or, when the first message includes the When the LADN information is described, and the terminal does not include the LADN information before receiving the first message, the terminal determines that the LAND available state changes in the registration area.

The information that the first registration area includes or does not include the LADN before receiving the first message may be determined according to the third message received in the first registration area, or determined according to the state of the PDU session accessing the LADN. The third message includes or does not include information about the LADN. The third message includes information of the LADN, indicating that the first registration area includes information of the LADN, and the third message does not include information of the LADN, indicating that the first registration area does not include information of the LADN. The third message may be a registration accept message or a terminal configuration update command message. The second message received by the terminal in the second registration area may be recorded, or the information of the first registration area including or not including the LADN may be recorded. When the terminal receives the first message, the first registration area may be directly determined according to the record. Information including or not including LADN before the first message.

In addition, the first registration area includes or does not include the information of the LADN before receiving the first message, and may also be determined according to the state of the PDU session in which the terminal accesses the LADN when the first message is received. For example, when the first message is received, the status of the PDU session in which the terminal accesses the LADN is unavailable, indicating that the first registration area does not include the LADN information before receiving the first message; when receiving the first message, the terminal The status of the PDU session accessing the LADN is available, indicating that the first registration area includes the LADN information before receiving the first message.

The state of the PDU session in which the terminal accesses the LADN is unavailable. Referring to the related description in the embodiment shown in FIG. 3, FIG. 4 and FIG.

The SMF can manage the PDU session based on the current registration area and the service area of the LADN, and the granularity is fine. It is solved that when the terminal is located outside the service area of the LADN, the terminal initiates the release of the PDU session, thereby reducing the signaling waste caused by the paging terminal when the PDU session exists, but the terminal is not in the service area of the LADN.

S830. Modify or release the PDU session.

When the first message does not include the information of the LADN, and the second registration area includes the information of the LADN, or when the first message does not include the information of the LADN, and the first registration area includes the information of the LADN before receiving the first message Revising or releasing the PDU session includes one or more of the following (see S330-S360 in conjunction with the embodiment shown in FIG. 3, and S510-S520 in conjunction with the embodiment shown in FIG. 5, and in conjunction with FIG. Related description of S603-S611 in the embodiment):

The terminal notifies the SMF to modify or release the PDU session;

The terminal marks the PDU session as unavailable;

The SMF marks the PDU session as unavailable;

The SMF notifies the UPF to drop the downlink data corresponding to the PDU session;

The SMF notifies the UPF to stop sending the downlink data notification DDN to the SMF.

When the first message includes information of the LADN, and the second registration area does not include the information of the LADN; or, When the first message includes information of the LADN, and the first registration area does not include the information of the LADN before receiving the first message; modifying or releasing the PDU session includes one or more of the following (refer to the combination shown in FIG. 4) Related description of S430-S460 in the embodiment):

The terminal notifies the SMF to modify the PDU session;

The terminal marks the PDU session as available;

The SMF marks the PDU session as available;

The SMF notifies the UPF to send downlink data corresponding to the PDU session;

The SMF notifies the UPF to send a downlink data notification DDN corresponding to the PDU session.

After modifying or releasing the PDU session on the network side, the terminal may be notified, so that the terminal can modify or release the PDU session synchronously, thereby reducing the message caused by the paging terminal when the terminal is not in the service area of the LADN due to the existence of the PDU session. Make a waste. By marking the PDU session, the terminal can count the number of times the terminal continuously enters the registration area of the service area that does not include the LADN, thereby setting a rule. When the registration area of the service area that does not include the LADN is continuously less than or equal to the set number of times, The terminal modifies the PDU session. When the set number of times is reached or exceeded, the terminal releases the PDU session, and the management granularity of the PDU session accessing the LADN is finer.

In addition, when the terminal re-enters the RA of the service area including the LADN, the PDU session of the access LADN can be re-enabled for data transmission, thereby managing the PDU session from a finer granularity, and making the network device to the terminal. The paging is more reasonable, saving signaling and improving efficiency.

The embodiment of the present application can be implemented. For a session of the LADN, when the terminal enters the registration area that does not support the LADN, the terminal modifies or releases the PDU session, thereby reducing the network device because the terminal is in the RA that does not support the LADN. The PDU session accessing the LADN has downlink data arriving and signaling waste caused by the paging terminal. also

FIG. 9 is a schematic diagram of signaling interaction of another method for session management according to an embodiment of the present disclosure. As shown in FIG. 9, the method includes:

S910. The UPF sends a DDN to the SMF. The DNN is used to indicate that downlink data corresponding to a PDU session with access to the LADN needs to be transmitted.

S920. The SMF invokes a first service provided by the AMF, where the first service is used by the SMF to request the AMF to send a message or information, such as N2SM information, to the access node AN. The message or information sent by the SMF to the access node AN through the AMF is used to instruct the SMF to request the AMF to send the message or information to the AN.

S930. The AMF determines that the PDU session is a session corresponding to the LADN, and the current registration area of the terminal has no service area of the available LADN.

S940, the AMF sends an indication parameter to the SMF, where the indication parameter is used to indicate that the LADN information is not included in the current registration area, and the indication parameter may be an acknowledgement of the message in S920.

If the downlink data belongs to the PDU session accessing the LADN, the AMF determines that the service area without the LADN in the current RA, and sends an indication (LADN unavailable indication in current TA) that the current registration area LADN is unavailable to the SMF. The AMF saves an indication that the LADN unavailable indication in current TA is sent to the SMF, and notifies the SMF after the terminal re-enters the RA of the service area including the LADN.

The AMF can save information that has sent indication parameters to the SMF. When the terminal re-enters the RA of the service area including the LADN, the SMF may be notified to re-enable the PDU session of the access LADN for data transmission, thereby managing the PDU session from a finer granularity, and making the network device to the terminal Paging is more reasonable and saves Signaling has improved efficiency.

S950: The SMF modifies the PDU session according to the indication parameter.

The SMF modifies the PDU session according to the indication parameters, including the SMF performing one or more of the following:

Notifying the UPF to drop the downlink data corresponding to the PDU session;

The UPF is notified to stop sending the downlink data notification DDN corresponding to the PDU session to the SMF.

FIG. 10 is another example provided by an embodiment of the present application. As shown in FIG. 10, the method specifically includes the following steps:

S1001: The terminal sends a registration request message to the AMF.

When the terminal moves, moving from one RA to another, the AMF may change, at which point the terminal can register with the new AMF.

S1002, the AMF determines that the available state of the LADN of the terminal changes.

If, the SMF subscribed to the AMF notification service before S1001. The notification service is used by the AMF to notify the SMF when a preset event occurs, wherein the preset event changes for the presence or absence of the LADN. S1002 can be executed at this time. The SMF subscription notification service to the AMF can be referred to the description in the embodiment shown in FIG. 7.

S1003. The AMF sends a notification message to the SMF.

If the SMF subscribes to the AMF to the notification service, the AMF needs to send the notification information to the SMF when it is determined in S1002 that the available state of the LADN of the terminal changes. The notification information can be referred to the description in the embodiment shown in FIG.

After receiving the notification message, the SMF can return a response.

After receiving the notification information, the SMF may perform S1005b, and the SMF modifies or releases the PDU session accessing the LADN. The SMF modifies or releases the PDU session accessing the LADN. Referring to the description in the embodiment shown in FIG.

S1004. The AMF sends a registration accept message to the terminal.

If the registration area of the terminal includes the LADN information, the AMF registration message to the terminal may include the LADN information, otherwise it is not included. The AMF sends a registration accept message to the terminal. For details, refer to the description in the embodiments shown in FIG. 3-6 and FIG.

When the terminal determines, according to the registration accept message received in S1004, that the information of the LADN in the registration area changes, the S1005a is executed, and the terminal modifies or releases the PDU session accessing the LADN. The terminal modifies or releases the PDU session accessing the LADN. See the description in the embodiment shown in FIG. 3-6 and FIG.

FIG. 11 is a schematic structural diagram of a terminal according to an embodiment of the present application. As shown in FIG. 11, the terminal includes a receiving unit 1101, a determining unit 1102, a modifying unit 1103, and a transmitting unit 1104. The terminal has a protocol data unit PDU session accessing the local area data network LADN, specifically,

The receiving unit 1101 is configured to receive, in the first registration area RA, a first message that is sent by the access management function entity AMF, where the first message includes or does not include information of the LADN; wherein the first RA Is the current registration area of the terminal;

a determining unit 1102, configured to determine, according to the first message, that an available state of the LADN changes;

The modifying unit 1103 is configured to modify the PDU session, or a releasing unit, configured to release the PDU session.

Optionally, the determining unit 1102 is further configured to:

Determining that the available state of the LADN changes when the first message does not include the information of the LADN and the information of the LADN is included in the first RA before the terminal receives the first message; Or

Determining that the available state of the LADN changes when the first message does not include the information of the LADN and the information of the LADN is included in the second RA;

The second RA is an RA before the terminal enters the first RA.

Optionally, the sending unit 1104 is configured to send, to the session management function entity SMF, a first session modification request message, where the first session modification request message includes a first indication, where the first indication is used to indicate The information of the LADN is not included in an RA; or a session release request message is sent to the SMF.

Optionally, the receiving unit 1101 is further configured to receive a first session modification command message sent by the SMF, where the first session modification command message includes an identifier of the PDU session and a first parameter, and an identifier of the PDU session For identifying the PDU session, the first parameter is used to indicate that the PDU session is unavailable.

Optionally, the modifying unit 1103 is further configured to: mark, by the terminal, that the PDU session is unavailable.

Optionally, the determining unit 1102 is further configured to: when the first message includes the information of the LADN, and the information of the LADN is not included in the first RA before the terminal receives the first message, Determining that the available state of the LADN changes; or, when the first message includes the information of the LADN, and the information of the LADN is not included in the second RA, determining that the available state of the LADN changes; The second RA is an RA before the terminal enters the first RA.

Optionally, the sending unit 1101 is further configured to send, to the SMF, a second session modification request message, where the second session modification request message includes a second indication, where the second indication is used to indicate that the LADN is included in the first RA Information.

Optionally, the receiving unit 1104 is further configured to:

Receiving a second session modification command message sent by the SMF, where the second session modification command message includes a second parameter, where the second parameter is used to indicate that the PDU session is available.

Optionally, the modifying unit 1103 is further configured to mark the PDU session as available.

The terminal can function as a terminal of the session management method as described in FIGS. 3 to 6, 8, and 10, and performs the steps performed by the terminal in FIGS. 3 to 6, 8, and 10. Therefore, the data loss caused by the network modification or release of the PDU session when the terminal is in the idle state is reduced, and the signaling waste caused by the paging terminal caused by the downlink data arrival of the network device accessing the LADN PDU session is also reduced.

FIG. 12 is a schematic structural diagram of an SMF according to an embodiment of the present application. As shown in FIG. 12, the SMF includes a receiving unit 1201, a modifying unit 1202, and a transmitting unit 1203. The SMF has a protocol data unit PDU session accessing the local area data network LADN, and the SMF includes:

The receiving unit 1201 is configured to receive a session modification request message sent by the terminal, where the session modification request message includes an indication, where the indication is used to indicate that the registration area includes or does not include information of the LADN;

The modifying unit 1202 is configured to modify the PDU session according to the indication.

Optionally, the method further includes: sending, by the sending unit 1203, when the indication is used to indicate that the RA of the terminal does not include the LADN, sending, by the terminal, a first session modification command message, where the first session modification command is The message includes an identifier of the PDU session and a first parameter, and the first parameter is used to indicate that the PDU session is unavailable.

Optionally, the modifying unit 1202 is further configured to: mark the PDU session as unavailable; notify the user plane function entity UPF to discard downlink data corresponding to the PDU session; and notify the UPF to stop sending downlink data notification to the SMF. DDN.

Optionally, the sending unit 1203 is further configured to: when the indication is used to indicate that the RA of the terminal does not include the LADN, send a second session modification command message to the terminal, where the second session modification command message is Including the stated An identifier of the PDU session and a second parameter, the second parameter is used to indicate that the PDU session is available.

Optionally, the modifying unit 1202 is further configured to: mark the PDU session as available; notify the UPF to send downlink data corresponding to the PDU session; and notify the UPF to send a downlink data notification DDN corresponding to the PDU session.

The SMF can be used as the SMF of the session management method as described in FIGS. 3 to 6, 8, and 10, and the steps performed by the SMFs in FIGS. 3 to 6, 8 and 10 are performed. Therefore, the data loss caused by the network modification or release of the PDU session when the terminal is in the idle state is reduced, and the signaling waste caused by the paging terminal caused by the downlink data arrival of the network device accessing the LADN PDU session is also reduced.

FIG. 13 is a schematic structural diagram of another SMF according to an embodiment of the present disclosure. As shown in FIG. 13, the SMF includes a subscribing unit 1301, and may further include a receiving unit 1302 and a modifying unit 1303. The SMF has a protocol data unit PDU session in which the terminal accesses the local area data network LADN, specifically,

a subscription unit 1301, configured to subscribe to a notification service to the access and mobility management function entity AMF, where the notification service is used to notify the SMF when a preset event occurs, where the preset event is LADN The available status changes.

Optionally, the subscription unit 1301 is further configured to:

Transmitting the data network name DNN of the LADN and the preset event to the AMF to subscribe to the notification service to the AMF.

Optionally, the available state of the LADN changes, including at least one of the following:

The information of the LADN is not included in the first registration area, and the information of the LADN is included in the second registration area;

Information in the first registration area is changed from information including the LADN to information not including the LADN;

The first registration area includes information of the LADN, and the information of the LADN is not included in the second registration area; or

Information that does not include the LADN in the first registration area is changed to information including the LADN;

The first registration area is a current registration area of the terminal, and the second registration area is a registration area before the terminal enters the first registration area.

Optionally, it also includes:

The receiving unit 1302 is configured to receive the notification information sent by the AMF, where the notification information is used to notify information in the registration area of the terminal that the LADN is included or not included.

Optionally, it also includes:

The modifying unit 1303 is configured to modify the PDU session according to the notification information.

Optionally, the modifying unit 1303 is further configured to:

When the notification information is used to notify that the registration area of the terminal does not include the information of the LADN, notify the user plane function entity UPF to discard the downlink data corresponding to the PDU session; notify the UPF to stop sending the PDU to the SMF. The downlink data corresponding to the session is notified to the DDN;

or,

When the notification information is used to notify that the registration area of the terminal includes the information of the LADN, notify the UPF to send downlink data corresponding to the PDU session; and notify the UPF to send a downlink data notification corresponding to the PDU session. DDN.

The SMF can be used as the SMF of the service subscription method as described in FIGS. 7 and 10, and the steps performed by the SMF in FIGS. 7 and 10 are performed. Thereby reducing the network modification or release of the PDU session when the terminal is in the idle state The loss of data also reduces the signaling waste caused by the paging terminal because the network device accesses the LADN PDU session with downlink data arriving.

FIG. 14 is a schematic structural diagram of an AMF according to an embodiment of the present application. As shown in FIG. 14, the AMF includes a subscribing unit 1401, and may further include a receiving unit 1402. The session management function entity SMF has a protocol data unit PDU session in which the terminal accesses the local area data network LADN, and includes:

The subscription unit 1401 is configured to receive the SMF subscription notification service, where the notification service is used to notify the SMF when a preset event occurs, where the preset event is a change in an available state of the LADN.

Optionally, the subscription unit 1402 is further configured to:

Receiving, by the SMF, the data network name DNN of the LADN and the preset event to accept the SMF to subscribe to the notification service.

The first registration area includes information of the LADN, and the information of the LADN is not included in the second registration area;

Optionally, it also includes:

The sending unit 1402 is configured to send, to the SMF, notification information, where the notification information is used to notify the registration area of the terminal that the information of the LADN is included or not.

The AMF can be used as the AMF of the method of service subscription as described in FIGS. 7 and 10, and the steps performed by the SMF in FIGS. 7 and 10 are performed. Therefore, the data loss caused by the network modification or release of the PDU session when the terminal is in the idle state is reduced, and the signaling waste caused by the paging terminal caused by the downlink data arrival of the network device accessing the LADN PDU session is also reduced.

FIG. 15 is a schematic structural diagram of another SMF provided by an embodiment of the present application. As shown in FIG. 15, the SMF has a PDU session accessing a LADN, and the SMF includes:

The receiving unit 1501 is configured to receive a downlink data notification corresponding to the PDU session sent by the user plane function entity UPF;

The sending unit 1502 is configured to invoke a first service provided by the access and mobility management entity AMF, where the first service is used by the SMF to send a message to the access node AN by using the AMF. ;

The receiving unit 1501 is further configured to receive an indication parameter sent by the AMF, where the indication parameter is used to indicate that the LADN information is not included in the current registration area;

The modifying unit 1503 is configured to modify the PDU session according to the indication parameter.

Optionally, the modifying unit 1503 is further configured to:

Notifying the user plane function entity UPF to discard the downlink data corresponding to the PDU session;

The SMF can be used as the SMF of the session management method as described in FIG. 9, and the steps performed by the SMF in FIG. 9 are performed. Therefore, the data loss caused by the network modification or release of the PDU session when the terminal is in the idle state is reduced, and the signaling wave caused by the paging terminal caused by the downlink data arrival of the network device accessing the LADN PDU session is also reduced. fee.

FIG. 16 is a schematic structural diagram of another AMF according to an embodiment of the present disclosure. As shown in FIG. 16, the SMF has a protocol data unit PDU session accessing the local area data network LADN, and the AMF includes:

The receiving unit 1601 is configured to receive a first service that is invoked by the SMF, where the first service is used by the SMF to send a message to the access node AN by using the AMF;

The sending unit 1602 is configured to send an indication parameter to the SMF when the service area of the LADN is not included in the registration area of the terminal, where the indication parameter is used to indicate that the LADN information is not included in the registration area.

Optionally, it also includes:

And a saving unit, configured to save information that the indication parameter has been sent to the SMF.

The AMF can be used as the AMF of the session management method as described in FIG. 9, and the steps performed by the AMF in FIG. 9 are performed. Therefore, the data loss caused by the network modification or release of the PDU session when the terminal is in the idle state is reduced, and the signaling waste caused by the paging terminal caused by the downlink data arrival of the network device accessing the LADN PDU session is also reduced.

FIG. 17 is a schematic structural diagram of another terminal according to an embodiment of the present application. As shown in FIG. 17, the terminal includes a transceiver 1701, a processor 1702, and a memory 1703 for communicating with an AMF, a UPF, or an SMF; the memory 1703 is for storing a program; the processor 1702 is for The program stored in the memory is executed to perform the steps performed by the terminal in the foregoing FIGS. 3-6 and 8. The terminal has a PDU session accessing the LADN, specifically,

The transceiver 1701 is configured to receive, in the first registration area RA, a first message sent by the access and mobility management function entity AMF, where the first message includes or does not include information of the LADN; wherein the first RA Is the current registration area of the terminal;

The processor 1702 is configured to determine, according to the first message, that an available state of the LADN changes;

The processor 1702 is configured to modify the PDU session; or, to release the PDU session.

Optionally, the processor 1702 is further configured to:

The second RA is an RA before the terminal enters the first RA.

Optionally, the transceiver 1701 is configured to send, to the session management function entity SMF, a first session modification request message, where the first session modification request message includes a first indication, where the first indication is used to indicate the first RA The information of the LADN is not included therein; or a session release request message is sent to the SMF.

Optionally, the transceiver 1701 is further configured to receive a first session modification command message sent by the SMF, where the first session modification command message includes an identifier of the PDU session and a first parameter, and an identifier of the PDU session. For identifying the PDU session, the first parameter is used to indicate that the PDU session is unavailable.

Optionally, the processor 1702 is further configured to: mark, by the terminal, that the PDU session is unavailable.

Optionally, the processor 1702 is further configured to: when the first message includes the information of the LADN, and the information of the LADN is not included in the first RA before the terminal receives the first message, Determining that the available state of the LADN changes; or, when the first message includes information of the LADN, and the second RA does not include Determining the available state of the LADN when the information of the LADN is changed;

The second RA is an RA before the terminal enters the first RA.

Optionally, the transceiver 1701 is further configured to send a second session modification request message to the SMF, where the second session modification request message includes a second indication, where the second indication is used to indicate that the registration area of the terminal includes the LADN information. .

Optionally, the transceiver 1701 is also used to,

Optionally, the processor 1702 is further configured to mark the PDU session as available.

FIG. 18 is a schematic structural diagram of another SMF according to an embodiment of the present application. As shown in FIG. 18, the SMF includes a transceiver 1801, a processor 1802, and a memory 1803, the transceiver 1801 is configured to communicate with an AMF, a UPF, or a terminal; the memory 1803 is configured to store a program; the processor 1802 is configured to: The program stored in the memory is executed to perform the steps performed by the SMFs in the aforementioned FIGS. 3-6, 8, and 10. The SMF has a PDU session accessing the LADN, specifically:

The transceiver 1801 is configured to receive a session modification request message sent by the terminal, where the session modification request message includes an indication, where the indication is used to indicate that the registration area includes or does not include information of the LADN;

The processor 1802 is configured to modify the PDU session according to the indication.

Optionally, the transceiver 1801 is configured to: when the indication is used to indicate that the RA of the terminal does not include the LADN, send a first session modification command message to the terminal, where the first session modification command is The message includes an identifier of the PDU session and a first parameter, and the first parameter is used to indicate that the PDU session is unavailable.

Optionally, the processor 1802 is further configured to: mark the PDU session as unavailable; notify the user plane function entity UPF to discard downlink data corresponding to the PDU session; and notify the UPF to stop sending downlink data notification to the SMF. DDN.

Optionally, the transceiver 1801 is further configured to: when the indication is used to indicate that the RA of the terminal does not include the LADN, send a second session modification command message to the terminal, where the second session modification command message is And including an identifier of the PDU session and a second parameter, where the second parameter is used to indicate that the PDU session is available.

Optionally, the processor 1802 is further configured to: mark the PDU session as available; notify the UPF to send downlink data corresponding to the PDU session; and notify the UPF to send a downlink data notification DDN corresponding to the PDU session.

FIG. 19 is a schematic structural diagram of another SMF according to an embodiment of the present disclosure. The SMF includes a transceiver 1901, a processor 1902 for communicating with an AMF, a UPF, or a terminal, and a memory 1903 for storing a program; the processor 1902 for executing the memory storage The program is to perform the steps performed by the SMFs in the aforementioned FIGS. 7 and 10. The SMF has a PDU session accessing the LADN, specifically:

The processor 1902 is configured to subscribe to a notification service to the access and mobility management function entity AMF, where the notification service is used to notify the SMF when a preset event occurs, where the preset event is LADN The available status changes.

Optionally, the processor 1902 is further configured to:

Optionally, it also includes:

The transceiver 1901 is configured to receive notification information sent by the AMF, where the notification information is used to notify that the registration area of the terminal includes or does not include information of the LADN.

Optionally, it also includes:

The processor 1902 is configured to modify the PDU session according to the notification information.

Optionally, the processor 1902 is further configured to:

or,

The SMF can be used as the SMF of the method of service subscription as described in FIG. 7 or FIG. 10, and the steps performed by the SMF in FIG. 7 or FIG. 10 are performed. Therefore, the data loss caused by the network modification or release of the PDU session when the terminal is in the idle state is reduced, and the signaling waste caused by the paging terminal caused by the downlink data arrival of the network device accessing the LADN PDU session is also reduced.

FIG. 20 is a schematic structural diagram of another AMF according to an embodiment of the present disclosure. The AMF includes a transceiver 2001 for communicating with an SMF or a terminal, and a memory 2003 for storing a program; the processor 2002 for performing the memory storage a program to perform the steps performed by the AMF in the aforementioned FIG. 7 or FIG. The SMF has a PDU session accessing the LADN, specifically:

The processor 2002 is configured to receive the SMF subscription notification service, where the notification service is used to notify the SMF when a preset event occurs, where the preset event is a change in an available state of the LADN.

Optionally, the processor 2002 is further configured to:

Receiving, by the SMF, the data network name DNN of the LADN and the preset event to accept the The SMF subscribes to the notification service.

Optionally, it also includes:

The transceiver 2001 is configured to send, to the SMF, notification information, where the notification information is used to notify the registration area of the terminal that the information of the LADN is included or not included.

The AMF can be used as the AMF of the method of service subscription as described in FIG. 7 or FIG. 10, and the steps performed by the SMF in FIG. 7 or FIG. 10 are performed. Therefore, the data loss caused by the network modification or release of the PDU session when the terminal is in the idle state is reduced, and the signaling waste caused by the paging terminal caused by the downlink data arrival of the network device accessing the LADN PDU session is also reduced.

FIG. 21 is a schematic structural diagram of another SMF provided by an embodiment of the present application. As shown in FIG. 21, the SMF includes a transceiver 2101 for communicating with an AMF, a UPF or a terminal, and a memory 2103 for storing a program; the processor 2102 is for storing a program; The program stored in the memory is executed to perform the steps performed by the SMF in Fig. 9 described above. The SMF has a PDU session accessing the LADN, and the SMF includes:

The transceiver 2101 is configured to receive a downlink data notification corresponding to the PDU session sent by the user plane function entity UPF.

The transceiver 2101 is configured to invoke a first service provided by the access and mobility management entity AMF, where the first service is used by the SMF to send a message to the access node AN through the AMF. ;

The transceiver 2101 receives an indication parameter sent by the AMF, where the indication parameter is used to indicate that the LADN information is not included in the current registration area.

The processor 2102 is configured to modify the PDU session according to the indication parameter.

Optionally, the processor 2102 is further configured to notify the user plane function entity UPF to discard the downlink data corresponding to the PDU session, and notify the UPF to stop sending the downlink data notification DDN corresponding to the PDU session to the SMF.

The SMF can be used as the SMF of the session management method as described in FIG. 9, and the steps performed by the SMF in FIG. 9 are performed. Therefore, the data loss caused by the network modification or release of the PDU session when the terminal is in the idle state is reduced, and the signaling waste caused by the paging terminal caused by the downlink data arrival of the network device accessing the LADN PDU session is also reduced.

FIG. 22 is a schematic structural diagram of another AMF according to an embodiment of the present disclosure. As shown in FIG. 22, the AMF includes a transceiver 2201, a processor 2202, and a memory 2203. The transceiver 2201 is configured to communicate with an SMF or a terminal; the memory 2203 is configured to store a program; and the processor 2202 is configured to execute The program stored in the memory is executed to perform the steps of the SMF execution described above in FIG. The SMF has a PDU session accessing the LADN, and the AMF includes:

a transceiver 2201, configured to receive a first service invoked by the SMF, where the first service is used by the SMF The AMF sends a message to the access node AN;

The transceiver 2201 is configured to send an indication parameter to the SMF when the service area of the LADN is not included in the registration area of the terminal, where the indication parameter is used to indicate that the LADN information is not included in the registration area.

Optionally, the method further includes a processor 2202, configured to save information that is sent to the SMF by the indication parameter.

Embodiments of the present application provide a computer program product comprising instructions that, when executed on a computer, perform the methods/steps of Figures 3 through 10 above.

The embodiment of the present application provides a computer readable storage medium for storing instructions, when the instructions are executed on a computer, performing the methods/steps in FIG. 3 to FIG. 10 above.

The embodiment of the present application provides a communication system. The system includes any one or more of the above-described embodiments described in connection with Figures 3-10.

In each of the above embodiments of the present invention, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in accordance with embodiments of the present invention are generated in whole or in part. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer readable storage medium or transferred from one computer readable medium to another computer readable medium, for example, the computer instructions can be wired from a website site, computer, server or data center (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (eg infrared, wireless, microwave, etc.) to another website site, computer, server or data center. The computer readable storage medium can be any available media that can be accessed by a computer or a data storage device such as a server, data center, or the like that includes one or more available media. The usable medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state hard disk) or the like.

The above description is only a preferred embodiment of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed in the present application. Replacement should be covered by the scope of this application. Therefore, the scope of protection of the present application should be determined by the scope of protection of the claims.

Claims

A method for session management, characterized in that the terminal has a protocol data unit PDU session accessing the local area data network LADN, including:

Receiving, by the terminal, the first message sent by the access and mobility management function entity AMF in the first registration area RA, where the first message includes or does not include information of the LADN; wherein the first RA is the The current registration area of the terminal;

Determining, by the terminal, that the available state of the LADN changes according to the first message;

The terminal modifies or releases the PDU session.
The method according to claim 1, wherein the terminal determines, according to the first message, that the available state of the LADN changes, including:

When the first message does not include the information of the LADN, and the information of the LADN is included in the first RA before the terminal receives the first message, the terminal determines an available state of the LADN. Changed; or,

When the first message does not include the information of the LADN, and the information of the LADN is included in the second RA, the terminal determines that the available state of the LADN changes;

The second RA is an RA before the terminal enters the first RA.
The method according to claim 2, wherein the modifying the PDU session by the terminal comprises:

The terminal sends a first session modification request message to the session management function entity SMF, where the first session modification request message includes a first indication, where the first indication is used to indicate that the first RA does not include LADN information; or,

The releasing the PDU session by the terminal includes: the terminal sending a session release request message to the SMF.
The method of claim 3, wherein the method further comprises:

Receiving, by the terminal, the first session modification command message sent by the SMF, where the first session modification command message includes an identifier of the PDU session and a first parameter, where the identifier of the PDU session is used to identify the PDU session. The first parameter is used to indicate that the PDU session is unavailable.
The method according to any one of claims 2-4, wherein the modifying the PDU session by the terminal comprises:

The terminal marks the PDU session as unavailable.
The method of claim 1 wherein

Determining, by the terminal, that the available state of the LADN changes according to the first message, including:

When the first message includes the information of the LADN, and the information of the LADN is not included in the first RA before the terminal receives the first message, the terminal determines an available state of the LADN. Changed; or,

When the first message includes the information of the LADN, and the information of the LADN is not included in the second RA, the terminal determines that the available state of the LADN changes;

The second RA is an RA before the terminal enters the first RA.
The method according to claim 6, wherein the modifying the PDU session by the terminal comprises:

The terminal sends a second session modification request message to the SMF, where the second session modification request message includes a second indication, where the second indication is used to indicate information that the LADN is not included in the first RA.
The method of claim 7, wherein the method further comprises:

The terminal receives a second session modification command message sent by the SMF, where the second session modification command message includes a second parameter, where the second parameter is used to indicate that the PDU session is available.
The method according to any one of claims 6-8, wherein the modifying the PDU session by the terminal comprises:

The terminal marks the PDU session as available.
A session management method, characterized in that the session management function entity SMF has a protocol data unit PDU session accessing the local area data network LADN, the method comprising:

The session management function entity SMF receives a session modification request message sent by the terminal, where the session modification request message includes an indication, where the indication is used to indicate that the registration area RA includes or does not include information of the LADN;

The SMF modifies the PDU session according to the indication.
The method according to claim 10, wherein, when the indication is used to indicate that the RA does not include information of a LADN, the SMF modifying the PDU session according to the indication, including:

The SMF sends a first session modification command message to the terminal, where the first session modification command message includes an identifier of the PDU session and a first parameter, where the first parameter is used to indicate that the PDU session is unavailable.
The method according to claim 11, wherein the SMF modifies the PDU session according to the indication, including one or more of the following:

The SMF marks the PDU session as unavailable;

The SMF notifies the user plane function entity UPF to discard the downlink data corresponding to the PDU session; or

The SMF notifies the UPF to stop sending a downlink data notification DDN to the SMF.
The method according to claim 10, wherein, when the indication is used to indicate that the RA does not include information of a LADN, the SMF modifying the PDU session according to the indication, including:

The SMF sends a second session modification command message to the terminal, where the second session modification command message includes an identifier of the PDU session and a second parameter, where the identifier of the PDU session is used to identify the PDU session. The second parameter is used to indicate that the PDU session is available.
The method according to claim 13, wherein the SMF modifies the PDU session according to the indication, including one or more of the following:

The SMF marks the PDU session as available;

The SMF notifies the UPF to send downlink data corresponding to the PDU session; or

The SMF notifies the UPF to send a downlink data notification DDN corresponding to the PDU session.
A method for service subscription, characterized in that the session management function entity SMF has a protocol data unit PDU session in which the terminal terminal accesses the local area data network LADN, and the method includes:

The SMF subscribes to the access and mobility management function entity AMF, and the notification service is used to notify the SMF when the preset event occurs, wherein the preset event is an available state of the LADN. Variety.
The method according to claim 15, wherein the SMF subscribes to the notification service to the AMF, including:

The SMF sends the data network name DNN of the LADN and the preset event to the AMF.
The method according to claim 15 or 16, wherein the available state of the LADN changes, including at least one of the following:

The information of the LADN is not included in the first registration area, and the information of the LADN is included in the second registration area;

Information in the first registration area is changed from information including the LADN to information not including the LADN;

The first registration area includes information of the LADN, and the information of the LADN is not included in the second registration area; or

Information that does not include the LADN in the first registration area is changed to information including the LADN;

The first registration area is a current registration area of the terminal, and the second registration area is a registration area before the terminal enters the first registration area.
The method according to any one of claims 15-17, further comprising: after the SMF subscribes to the notification service to the AMF, the method further comprises:

The SMF receives the notification information sent by the AMF, where the notification information is used to notify information about the LADN in the current registration area of the terminal.
The method of claim 18, after the receiving, by the SMF, the notification information, further comprising:

The SMF modifies the PDU session according to the notification information.
The method according to claim 19, wherein the modifying, by the SMF, the PDU session according to the notification information comprises:

When the notification information is used to notify that the current registration area of the terminal does not include the information of the LADN, the SMF performs one or more of the following:

Notifying the user plane function entity UPF to discard the downlink data corresponding to the PDU session;

Notifying the UPF to stop sending the downlink data notification DDN corresponding to the PDU session to the SMF;
The method according to claim 19, wherein the modifying, by the SMF, the PDU session according to the notification information comprises:

When the notification information is used to notify the terminal that the current registration area includes the information of the LADN, the SMF performs one or more of the following:

Notifying the UPF to send downlink data corresponding to the PDU session;

Notifying the UPF to send a downlink data notification DDN corresponding to the PDU session.
A method for service subscription, characterized in that the access and mobility management function entity AMF has a protocol data unit PDU session in which the terminal accesses the local area data network LADN, and the method includes:

Receiving, by the AMF, a subscription notification service request sent by the SMF, where the notification service request is used to notify the SMF when a preset event occurs, where the preset event is a change of an available state of the LADN .
The method according to claim 22, wherein the AMF receives the subscription notification service request sent by the SMF, including:

The AMF receives the data network name DNN of the LADN sent by the SMF and the preset event.
The method according to claim 22 or 23, wherein the available state of the LADN changes, including at least one of the following:

The information of the LADN is not included in the first registration area, and the information of the LADN is included in the second registration area;

Information in the first registration area is changed from information including the LADN to information not including the LADN;

The first registration area includes information of the LADN, and the information of the LADN is not included in the second registration area;

Information that does not include the LADN in the first registration area is changed to information including the LADN;

The first registration area is a current registration area of the terminal, and the second registration area is a registration area before the terminal enters the first registration area.
The method according to any one of claims 22-24, wherein after the AMF receives the subscription notification service request sent by the SMF, the method further includes:

The AMF sends notification information to the SMF, where the notification information is used to notify that the current registration area of the terminal includes or does not include information of the LADN.
A session management method, characterized in that the session management function entity SMF has a protocol data unit PDU session accessing the local area data network LADN, the method comprising:

Receiving, by the SMF, a downlink data notification corresponding to the PDU session sent by the user plane function entity UPF;

The SMF invokes a first service provided by the mobile management entity AMF, where the first service is used by the SMF to send a message to the access node AN through the AMF;

The SMF receives an indication parameter sent by the AMF, where the indication parameter is used to indicate that the LADN information is not included in the current registration area;

The SMF modifies the PDU session according to the indication parameter.
The method according to claim 26, wherein the SMF modifies the PDU session according to the indication parameter, including the SMF performing one or more of the following:

Notifying the user plane function entity UPF to discard the downlink data corresponding to the PDU session;

The UPF is notified to stop sending the downlink data notification DDN corresponding to the PDU session to the SMF.
A session management method, characterized in that the access and mobility management entity AMF has a protocol data unit PDU session accessing the local area data network LADN, the method comprising:

The AMF receives a first service request invoked by the session management function entity SMF, the first service request is used by the SMF to request the AMF to send a message to the access node AN, where the first service request includes the PDU The identity of the session;

When the service area of the LADN is not included in the registration area of the terminal, the AMF sends an indication parameter to the SMF, where the indication parameter is used to indicate that the LADN information is not included in the registration area of the terminal.
The method according to claim 28, wherein after the AMF sends the indication parameter to the SMF, the method further includes:

The AMF saves information that the indication parameter has been sent to the SMF.
A terminal, wherein the terminal has a protocol data unit PDU session accessing a local area data network LADN, and the terminal includes:

Receiving, in the first registration area RA, the first message sent by the access and mobility management function entity AMF, where the first message includes or does not include information of the LADN; wherein the first RA is the The current registration area of the terminal;

a determining unit, configured to determine, according to the first message, that an available state of the LADN changes;

a modifying unit, configured to modify the PDU session; or a releasing unit, configured to release the PDU session.
The terminal according to claim 30, wherein the determining unit is further configured to:

Determining that the available state of the LADN changes when the first message does not include the information of the LADN and the information of the LADN is included in the first RA before the terminal receives the first message; or,

Determining that the available state of the LADN changes when the first message does not include the information of the LADN and the information of the LADN is included in the second RA; the second RA is the terminal entering the first RA before a RA.
The terminal according to claim 31, further comprising: the sending unit, configured to send a first session modification request message to the session management function entity SMF, where the first session modification request message includes a first indication, The first indication is used to indicate information that the LADN is not included in the first RA; or, a session release request message is sent to the SMF.
The terminal according to claim 32, wherein the receiving unit is further configured to receive a first session modification command message sent by the SMF, where the first session modification command message includes an identifier of the PDU session and The first parameter, the identifier of the PDU session is used to identify the PDU session, and the first parameter is used to indicate that the PDU session is unavailable.
The terminal according to any one of claims 31 to 33, wherein the modifying unit is further configured to: the terminal marks the PDU session as unavailable.
The terminal according to claim 30, wherein the determining unit is further configured to: when the first message includes information of the LADN, and before the terminal receives the first message, the first When the information of the LADN is not included in the RA, it is determined that the available state of the LADN changes; or

Determining that an available state of the LADN changes when the first message includes information of the LADN and information that does not include the LADN in the second RA; the second RA is that the terminal enters the first RA before a RA.
The terminal according to claim 35, wherein the sending unit is further configured to send a second session modification request message to the SMF, where the second session modification request message includes a second indication, where the second indication is Information indicating the LADN is included in the first RA.
The terminal according to claim 36, wherein said receiving unit is further configured to:

Receiving a second session modification command message sent by the SMF, where the second session modification command message includes a second parameter, where the second parameter is used to indicate that the PDU session is available.
The terminal according to any one of claims 35 to 37, wherein the modifying unit is further configured to mark the PDU session as available.
A session management function entity SMF, wherein the SMF has a protocol data unit PDU session accessing a local area data network LADN, and the SMF includes:

a receiving unit, configured to receive a session modification request message sent by the terminal, where the session modification request message includes an indication, where the indication is used to indicate that the registration area RA includes or does not include information of the LADN;

And a modifying unit, configured to modify the PDU session according to the indication.
The SMF according to claim 39, further comprising: a transmitting unit for when said finger When indicating that the RA does not include the information of the LADN,

Sending a first session modification command message to the terminal, where the first session modification command message includes an identifier of the PDU session and a first parameter, where the first parameter is used to indicate that the PDU session is unavailable.
The SMF according to claim 40, wherein said modifying unit is further configured to:

Marking the PDU session as unavailable;

Notifying the user plane function entity UPF to discard the downlink data corresponding to the PDU session; or

Notifying the UPF to stop sending a downlink data notification DDN to the SMF.
The SMF according to claim 39, further comprising: a transmitting unit, configured to: when the indication is used to indicate that the RA of the terminal does not include information of the LADN,

And sending, by the terminal, a second session modification command message, where the second session modification command message includes an identifier of the PDU session and a second parameter, where the second parameter is used to indicate that the PDU session is available.
The SMF according to claim 42, wherein the modifying unit is further configured to:

Marking the PDU session as available;

Notifying the UPF to send downlink data corresponding to the PDU session; or

Notifying the UPF to send a downlink data notification DDN corresponding to the PDU session.
A session management function entity SMF, wherein the SMF has a protocol data unit PDU session in which the terminal accesses the local area data network LADN, and the SMF includes:

a subscription unit, configured to subscribe to a notification service to the access and mobility management function entity AMF, the notification service is configured to notify the SMF when the preset event occurs, wherein the preset event is available for the LADN The status changes.
The SMF according to claim 44, wherein said subscribing unit is further configured to:

Sending the data network name DNN of the LADN and the preset event to the AMF.
The SMF of claim 44 or 45, wherein the available state of the LADN changes, including at least one of the following:

The information of the LADN is not included in the first registration area, and the information of the LADN is included in the second registration area;

Information in the first registration area is changed from information including the LADN to information not including the LADN;

The first registration area includes information of the LADN, and the information of the LADN is not included in the second registration area; or

Information that does not include the LADN in the first registration area is changed to information including the LADN;

The first registration area is a current registration area of the terminal, and the second registration area is a registration area before the terminal enters the first registration area.
The SMF of any of claims 44-46, further comprising:

And a receiving unit, configured to receive the notification information sent by the AMF, where the notification information is used to notify information about the LADN in the current registration area of the terminal.
The SMF of claim 47, further comprising:

And a modifying unit, configured to modify the PDU session according to the notification information.
The SMF according to claim 48, wherein the modifying unit is further configured to: when the notification information is used to notify that the current registration area of the terminal does not include the information of the LADN, perform the following one Or more Item: notifying the user plane function entity UPF to discard the downlink data corresponding to the PDU session; notifying the UPF to stop sending the downlink data notification DDN corresponding to the PDU session to the SMF.
The SMF according to claim 48, wherein the modifying unit is further configured to: when the notification information is used to notify that the current registration area of the terminal includes information of the LADN, perform the following or And sending the downlink data corresponding to the PDU session to the UPF; and informing the UPF to send the downlink data notification DDN corresponding to the PDU session.
An access and mobility management function entity AMF, characterized in that the session management function entity SMF has a protocol data unit PDU session in which the terminal accesses the local area data network LADN, and the method includes:

a subscription unit, configured to receive a subscription notification service request message sent by the SMF, where the notification service is used to notify the SMF when a preset event occurs, where the preset event is an available state of the LADN A change has occurred.
The AMF according to claim 51, wherein the subscribing unit is further configured to receive a data network name DNN of the LADN and the preset event sent by the SMF.
The AMF of claim 51 or 52, wherein the available state of the LADN changes, including at least one of the following:

The information of the LADN is not included in the first registration area, and the information of the LADN is included in the second registration area;

Information in the first registration area is changed from information including the LADN to information not including the LADN;

The first registration area includes information of the LADN, and the information of the LADN is not included in the second registration area;

Information that does not include the LADN in the first registration area is changed to information including the LADN;

The first registration area is a current registration area of the terminal, and the second registration area is a registration area before the terminal enters the first registration area.
The AMF according to any one of claims 52-53, further comprising:

And a sending unit, configured to send, to the SMF, notification information, where the notification information is used to notify that the registration area of the terminal includes or does not include information of the LADN.
A session management function entity SMF, wherein the SMF has a protocol data unit PDU session accessing a local area data network LADN, and the SMF includes:

a receiving unit, configured to receive a downlink data notification corresponding to the PDU session sent by the user plane function entity UPF;

a sending unit, configured to invoke a first service provided by the access and mobility management entity AMF, where the first service is used by the SMF to send a message to the access node AN by using the AMF;

The receiving unit is further configured to receive an indication parameter sent by the AMF, where the indication parameter is used to indicate that the LADN information is not included in the current registration area;

And a modifying unit, configured to modify the PDU session according to the indication parameter.
The SMF according to claim 55, wherein said modifying unit is further configured to:

Notifying the user plane function entity UPF to discard the downlink data corresponding to the PDU session;

The UPF is notified to stop sending the downlink data notification DDN corresponding to the PDU session to the SMF.
An access and mobility management function entity AMF, characterized in that AMF has access to local area data Protocol Data Unit PDU session of the network LADN, the AMF including:

a receiving unit, configured to receive a first service invoked by a session management function entity SMF, where the first service is used by the SMF to send a message to the access node AN by using the AMF;

The sending unit is configured to send an indication parameter to the SMF when the service area of the LADN is not included in the registration area of the terminal, where the indication parameter is used to indicate that the LADN information is not included in the registration area.
The AMF of claim 57, further comprising:

And a saving unit, configured to save information that the indication parameter has been sent to the SMF.
A session management function entity SMF, comprising: a transceiver, a processor and a memory, wherein the transceiver is configured to communicate with an access and mobility management function entity AMF, a user plane function entity UPF or a terminal; the memory is used for storing The program is operative to execute the program stored by the memory to perform the method of any of claims 10-21, 26-27.
An access and mobility management function entity AMF, comprising: a transceiver, a processor and a memory, the transceiver for communicating with a session management function entity SMF or a terminal; the memory for storing a program; The program stored in the memory is executed to perform the method of any one of claims 22-25, 28-29.
A terminal, comprising: a transceiver, a processor and a memory, wherein the transceiver is configured to communicate with an access and mobility management function entity AMF or a session management function entity SMF; the memory is configured to store a program; The program stored in the memory is executed to perform the method of any of claims 1-9.
A computer readable storage medium comprising computer readable instructions which, when read and executed by a computer, cause a computer to perform the method of any of claims 1-29.
A computer program product comprising computer readable instructions which, when read and executed by a computer, cause a computer to perform the method of any of claims 1-29.
A communication system, comprising: the terminal according to any one of claims 30-38 and the session management function entity SMF according to any one of claims 39-43.
A communication system, comprising: a session management function entity SMF according to any one of claims 44-50; and an access and mobility management function entity AMF according to any one of claims 51-54; Alternatively, the SMF of claim 55 or 56 and the AMF of claim 57 or 58.