CN117641491A - Session migration control method, device, network equipment and medium - Google Patents

Abstract

The application discloses a session migration control method, a device, network side equipment and a medium, which belong to the technical field of communication, and the session migration control method in the embodiment of the application comprises the following steps: the method comprises the steps that first network side equipment determines a second network slice with a migration mapping relation corresponding to a first network slice accessed by a first terminal; the first network side equipment controls the first terminal to migrate the first session in the first network slice to the second network slice.

Description

Session migration control method, device, network equipment and medium

Technical Field

The application belongs to the technical field of communication, and particularly relates to a session migration control method, a session migration control device, network side equipment and a medium.

Background

The network slicing is an on-demand networking mode, and is a concept which can carry out differentiation processing according to terminal requirements. By means of the slicing, different flows can be differentiated, and resources can be isolated. Different terminals may have different service requirements, which network slices the terminals may be required to use according to the service level agreement (Service Level Agreement, SLA).

Aiming at the requirements of diversified services, the terminal can sign up and acquire a plurality of network slice services at the same time. When a terminal is registered in a network slice, the currently registered network slice may not be available due to various reasons such as that the service level protocol of the currently registered network slice does not meet the service requirement, that the terminal moves out of the coverage of the currently registered network slice, that the operation and maintenance policy of the currently registered network slice is modified, and the like, so that session migration between the network slices is required.

However, in the related art, session migration is only limited to the inside of the network slices, and no explicit method is provided at present how to implement session migration between the network slices to avoid service interruption provided for the terminal.

Disclosure of Invention

The embodiment of the application provides a session migration control method, a session migration control device, network side equipment and a session migration control medium, so as to realize session migration between network slices, avoid interruption of service provided for a terminal and ensure service continuity of the terminal.

In a first aspect, a session migration control method is provided, including:

the method comprises the steps that first network side equipment determines a second network slice with a migration mapping relation corresponding to a first network slice accessed by a first terminal;

The first network side device controls the first terminal to migrate a first session in the first network slice to the second network slice.

In a second aspect, there is provided a session migration control apparatus including:

the first determining module is used for determining a second network slice with a migration mapping relation corresponding to a first network slice accessed by the first terminal;

and the control module is used for controlling the first session of the first terminal in the first network slice to migrate into the second network slice.

In a third aspect, a network side device is provided, comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the method as described in the first aspect.

In a fourth aspect, there is provided a readable storage medium having stored thereon a program or instructions which when executed by a processor perform the steps of the method according to the first aspect.

In a fifth aspect, there is provided a computer program/program product stored in a storage medium, the computer program/program product being executed by at least one processor to carry out the steps of the method according to the first aspect.

In the embodiment of the application, after the first network side device determines the second network slice with the migration mapping relation corresponding to the first network slice accessed by the first terminal, the first session of the first terminal in the first network slice can be controlled to migrate to the second network slice, and the second network slice continuously provides services for the terminal, so that session migration among the network slices is realized, service interruption provided for the terminal is avoided, and terminal service continuity is ensured.

Drawings

Fig. 1 is a block diagram of a wireless communication system to which embodiments of the present application are applicable;

FIG. 2 is a flowchart illustrating a method for controlling session migration according to an embodiment of the present application;

fig. 3 is a schematic diagram of an initial registration procedure of a network slice in an embodiment of the present application;

fig. 4 is a schematic diagram of a session migration flow between network slices in the embodiment of the present application;

fig. 5 is a schematic diagram of determining a migration mapping relationship during handover of a radio access network in an embodiment of the present application;

fig. 6 is a schematic structural diagram of a session migration control device in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a network side device in an embodiment of the present application;

fig. 8 is a schematic structural diagram of another network side device in an embodiment of the present application.

Detailed Description

Technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application are within the scope of the protection of the present application.

The terms first, second and the like in the description and in the claims, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application are capable of operation in sequences other than those illustrated or otherwise described herein, and that the terms "first" and "second" are generally intended to be used in a generic sense and not to limit the number of objects, for example, the first object may be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/" generally means a relationship in which the associated object is an "or" before and after.

It is noted that the techniques described in embodiments of the present application are not limited to long term evolution (Long Term Evolution, LTE)/LTE evolution (LTE-Advanced, LTE-a) systems, but may also be used in other wireless communication systems, such as code division multiple access (Code Division Multiple Access, CDMA), time division multiple access (Time Division Multiple Access, TDMA), frequency division multiple access (Frequency Division Multiple Access, FDMA), orthogonal frequency division multiple access (Orthogonal Frequency Division Multiple Access, OFDMA), single carrier frequency division multiple access (Single-carrier Frequency Division Multiple Access, SC-FDMA), and other systems. The terms "system" and "network" in embodiments of the present application are often used interchangeably, and the techniques described may be used for both the above-mentioned systems and radio technologies, as well as other systems and radio technologies. The following description describes a New air interface (NR) system for purposes of example and uses NR terminology in much of the description that follows, but these techniques are also applicable to applications other than NR system applications, such as generation 6 (6) ^th Generation, 6G) communication system.

Fig. 1 shows a block diagram of a wireless communication system to which embodiments of the present application are applicable. The wireless communication system includes a terminal 11 and a network device 12.

The terminal 11 may be a mobile phone, a tablet (Tablet Personal Computer), a Laptop (Laptop Computer) or a terminal-side Device called a notebook, a personal digital assistant (Personal Digital Assistant, PDA), a palm top, a netbook, an ultra-mobile personal Computer (ultra-mobile personal Computer, UMPC), a mobile internet appliance (Mobile Internet Device, MID), an augmented reality (augmented reality, AR)/Virtual Reality (VR) Device, a robot, a Wearable Device (weather Device), a vehicle-mounted Device (VUE), a pedestrian terminal (PUE), a smart home (home Device with a wireless communication function, such as a refrigerator, a television, a washing machine, or a furniture), a game machine, a personal Computer (personal Computer, PC), a teller machine, or a self-service machine, and the Wearable Device includes: intelligent wrist-watch, intelligent bracelet, intelligent earphone, intelligent glasses, intelligent ornament (intelligent bracelet, intelligent ring, intelligent necklace, intelligent anklet, intelligent foot chain etc.), intelligent wrist strap, intelligent clothing etc.. Note that, the specific type of the terminal 11 is not limited in the embodiment of the present application.

The network side device 12 may comprise an access network device or a core network device.

The access network device may also be referred to as a radio access network device, a radio access network (Radio Access Network, RAN), a radio access network function or a radio access network element, among others. The access network device may include a base station, a WLAN access point, a WiFi node, or the like, where the base station may be referred to as a node B, an evolved node B (eNB), an access point, a base transceiver station (Base Transceiver Station, BTS), a radio base station, a radio transceiver, a basic service set (Basic Service Set, BSS), an extended service set (Extended Service Set, ESS), a home node B, a home evolved node B, a transmission receiving point (Transmitting Receiving Point, TRP), or some other suitable terminology in the field, and the base station is not limited to a specific technical vocabulary so long as the same technical effect is achieved, and it should be noted that in the embodiment of the present application, only the base station in the NR system is described by way of example, and the specific type of the base station is not limited.

The core network device may include, but is not limited to, at least one of: core network nodes, core network functions, mobility management entities (Mobility Management Entity, MME), access mobility management functions (Access and Mobility Management Function, AMF), session management functions (Session Management Function, SMF), user plane functions (User Plane Function, UPF), policy control functions (Policy Control Function, PCF), policy and charging rules function units (Policy and Charging Rules Function, PCRF), edge application service discovery functions (Edge Application Server Discovery Function, EASDF), unified data management (Unified Data Management, UDM), unified data repository (Unified Data Repository, UDR), home subscriber server (Home Subscriber Server, HSS), centralized network configuration (Centralized network configuration, CNC), network storage functions (Network Repository Function, NRF), network opening functions (Network Exposure Function, NEF), local NEF (or L-NEF), binding support functions (Binding Support Function, BSF), application functions (Application Function, AF), and the like. In the embodiment of the present application, only the core network device in the NR system is described as an example, and the specific type of the core network device is not limited.

For ease of understanding, related techniques and concepts related to the embodiments of the present application are described first.

In the network slice selection procedure, for AMF selection, the terminal may provide network slice selection assistance information (Network Slice Selection Assistance Information, nsai) or temporary identification (Temp ID) in the network slice registration request for selection. The network slice registration request is Non-Access Stratum (NAS) information, and may be carried in a radio resource control (Radio Resource Control, RRC) setup complete message. Temp ID can be understood as 5G S-temporary Mobile subscription identifier (5G S-Temporary Mobile Subscription Identifier, 5G-S-TMSI), a short form of 5G globally unique temporary UE identifier (5G Globally Unique Temporary UE Identifier,5G-GUTI).

For initial attachment, the terminal may provide network slice selection assistance information to support selection of AMFs. If network slice selection assistance information is available, the base station (gNB) may select an appropriate AMF using the network slice selection assistance information. If the base station cannot select the AMF using the network slice selection assistance information or the terminal does not provide any network slice selection assistance information, the base station transmits NAS signaling to the default AMF. Each base station will have a default corresponding AMF that is responsible for selecting the appropriate AMF and forwarding the request to the selected serving AMF. Finally, the AMF will issue the Temp ID and nsai information to the terminal through registration accept (Registration Accept) information, which may include: access-allowed nsai, configured nsai, etc.

For subsequent registration requests, the terminal may use the Temp ID to enable a more efficient wireless signaling procedure for AMF selection, because once the terminal initially attaches to a selected serving AMF, the serving AMF may assign the terminal a Temp ID that may uniquely identify the AMF. Thus, as long as the Temp ID is valid, the base station can route NAS information to the appropriate AMF, where the base station knows and can access the AMF associated with the Temp ID.

The 5G system supports three different session and service continuation modes (Session and Service Continuity Mode, SSC mode). The SSC pattern of a PDU session does not change throughout the life of the PDU session, i.e. a PDU session is set to SSC mode-X at its establishment, then the pattern of this PDU session is not modifiable and is SSC mode-X until it is deactivated.

SSC mode 1：

For the PDU session of SSC mode 1, the network will always maintain the UPF, which acts as a PDU session anchor at the time of PDU session establishment, regardless of the access technology, e.g., access type and cell, that the terminal continues to use for accessing the network.

For PDU sessions of IP type, the IP address assigned to the terminal is unchanged, which is the so-called IP address continuity.

When IPv6 multi-homing (multi-homing) or uplink classifier (UL CL) is applied to SSC mode1, the network assigns additional PDU session anchors (PDU Session Anchor) to the PDU session (based on local policy), which can be released and assigned, and the terminal cannot consider these additional IPv6 prefixes to be maintained by the network throughout the PDU session lifetime.

The SSC mode1 can be applied to any PDU session type and any access type.

SSC mode 2：

If a PDU session of SSC mode 2 has a PDU session anchor point, if the Network wants to migrate the anchor point UPF and the service SMF, in order to maintain the continuity service, the Network will let the terminal initiate a new PDU session establishment procedure again immediately after releasing the PDU session, and connect to the same Data Network (DN).

Otherwise, if one PDU session of SSC mode 2 has multiple PDU session anchors, i.e., multi-homing PDU Session or a scenario using UL CL, the additional PDU session anchors may be released or allocated.

The SSC mode 2 can be applied to any PDU session type and any access type.

SSC mode3：

For the PDU session of SSC mode 3, the network allows a connection to be established through the new PDU session anchor before the connection between the terminal and the previous PDU session anchor is released. That is, when migrating the anchor point, firstly establishing a PDU session connection passing through the new anchor point, accessing the same DN, and then releasing the PDU session connection of the old anchor point.

The difference between the SSC mode 3 and the SSC mode 2 is that the SSC mode 3 is to firstly establish the connection of the new anchor point and then release the connection of the old anchor point to ensure the continuity of the service, and the mode 2 is to firstly release the connection of the old anchor point and then immediately establish the connection of the new anchor point to ensure the continuity of the service.

The SSC mode 3 is applicable only to PDU sessions of an IP type, and an access type may be 3GPP or non-3GPP.

The related technology and concepts related to the embodiments of the present application are described above, and the session migration control method provided by the embodiments of the present application is described in detail below through some embodiments and application scenarios thereof with reference to the accompanying drawings.

Referring to fig. 2, a flowchart of an implementation of a session migration control method according to an embodiment of the present application is shown, where the method may include the following steps:

s210: the first network side equipment determines a second network slice with a migration mapping relation corresponding to a first network slice accessed by the first terminal.

As mentioned before, a terminal may sign up for and acquire multiple network slice services at the same time. When a terminal is registered in a network slice, the currently registered network slice may not be available due to various reasons such as that the service level protocol of the currently registered network slice does not meet the service requirement, that the terminal moves out of the coverage of the currently registered network slice, that the operation and maintenance policy of the currently registered network slice is modified, and the like, so that session migration between the network slices is required.

When session migration between network slices is to be performed for a session of a first terminal, the first network side device may determine a second network slice with a migration mapping relationship corresponding to the first network slice accessed by the first terminal. The first network slice may be one or more of allowed access network slices of the first terminal, for which a second network slice having a migration mapping relationship with the first network slice is predetermined. The network slices with migration mapping relationships corresponding to the same network slice may be the same or different for different terminals. A third network slice having a migration mapping relationship with the first network slice is determined as for the second terminal.

The first network side device may specifically be an AMF.

S220: the first network side equipment controls the first terminal to migrate the first session in the first network slice to the second network slice.

After the first terminal accesses the first network slice, a session connection may be established. When session migration between network slices is to be performed for a session of a first terminal, after determining a second network slice with a migration mapping relationship corresponding to the first network slice, the first network side device may control the first session of the first terminal in the first network slice to migrate to the second network slice. Specifically, the first network side device may send a migration instruction to the first terminal, and the first terminal may perform session migration between network slices according to the migration instruction. In this way, the terminal can continue to perform service processing in the second network slice, and accept the service provided by the second network slice.

After the first network side device determines the second network slice with the migration mapping relation corresponding to the first network slice accessed by the first terminal, the first network side device can control the first session of the first terminal in the first network slice to migrate into the second network slice, and the second network slice continuously provides services for the terminal, so that session migration among different network slices is realized, service interruption provided for the terminal is avoided, and terminal service continuity is ensured.

In one embodiment of the present application, the first network side device controlling migration of a first session of the first terminal in the first network slice to the second network slice may include the following steps:

the first network side equipment sends first session migration indication information to the first terminal, wherein the first session migration indication information is used for indicating the first terminal to release the first session in the first network slice and then establish the second session in the second network slice.

In this embodiment of the present application, when session migration between network slices is to be performed for a session of a first terminal, after determining, by a first network side device, a second network slice having a migration mapping relationship corresponding to a first network slice to which the first terminal accesses, the first network side device may send first session migration indication information to the first terminal. The first session migration indication information may indicate that the first terminal releases the first session in the first network slice before establishing the second session in the second network slice. I.e. SSC mode2 is used. According to the first session migration indication information, the first terminal can firstly release the first session in the first network slice, then initiate the second session, directly point to the second network slice, and establish the second session in the second network slice. Session migration between network slices is achieved.

In one embodiment of the present application, the first network side device controlling migration of a first session of the first terminal in the first network slice to the second network slice may include the following steps:

the first network side equipment sends second session migration indication information to the first terminal, wherein the second session migration indication information is used for indicating the first terminal to release the first session in the first network slice after the first terminal establishes a third session in the second network slice.

In this embodiment of the present application, when session migration between network slices is to be performed for a session of a first terminal, after determining, by a first network side device, a second network slice having a migration mapping relationship corresponding to a first network slice to which the first terminal accesses, second session migration instruction information may be sent to the first terminal. The second session migration indication information may indicate that the first terminal establishes the third session in the second network slice before releasing the first session in the first network slice. I.e. SSC mode3 is used. The first terminal may initiate a third session according to the second session migration indication information, point to the second network slice, and release the first session in the first network slice after the third session is established in the second network slice. Session migration between network slices is achieved.

In one embodiment of the present application, the third session is different from the session anchor point corresponding to the first session. The first terminal can establish a session connection passing through the new session anchor point according to the second session migration indication information, and establish a third session in the second network slice.

In one embodiment of the present application, the network address associated with the third session is used for the transmission of the new traffic flow. After establishing the third session in the second network slice, the first terminal may use a network address, such as an IP address/prefix, associated with the third session for transmission of the new traffic stream, while also actively moving the existing traffic stream from the first session to the third session. After the third session is established, uplink and downlink data are transmitted from the third session and are not transmitted from the first session. The network address associated with the third session refers to the address of the original session, i.e. the address of the first session.

In one embodiment of the present application, before the first network side device controls the first terminal to migrate the first session in the first network slice into the second network slice, the method further includes:

the first network side equipment sends the context information of the first session to the first terminal.

In the embodiment of the application, when the session migration between the network slices is to be performed for the session of the first terminal, the first network side device can acquire the context information of the first session of the first terminal in the first network slice, then send the context information of the first session to the first terminal, and the first terminal establishes a second session or a third session in the second network slice according to the context information of the first session, so that the success rate of session establishment is improved, and the continuity of terminal services is further ensured.

In an embodiment of the present application, before the first network side device determines the second network slice with the migration mapping relationship corresponding to the first network slice accessed by the first terminal, the method may further include the following steps:

the first network side equipment determines a first session according to the network deployment information;

or,

the first network side equipment determines a first session according to the received session migration information sent by the second network side equipment.

In the embodiment of the application, the first network side device may decide whether to perform session migration between network slices according to the network deployment information. If it is determined that the first network slice accessed by the first terminal is unavailable or the access type of the first network slice is adjusted according to the network deployment information, it may be determined that the first session of the first terminal in the first network slice is to be migrated.

Or the second network side device may determine that session migration between network slices is to be performed when the first network slice accessed by the first terminal has a problem or needs to be adjusted, and may send session migration information to the first network side device. The first network side device can determine that a first session of the first terminal in the first network slice is to be migrated when receiving session migration information sent by the second network side device. The second network side device may be specifically an SMF.

The session migration information may include information of at least one of:

context information of the first session;

identification information of the first session;

an N1 interface session management container (N1 SM container);

session management function reassignment (SMF reassignment) requests.

The session migration information sent by the second network side device to the first network side device may include at least one of the foregoing information, where the first network side device receives the session migration information sent by the second network side device, and may effectively control, according to the information included therein, migration of the first session of the first terminal in the first network slice to the second network slice.

In one embodiment of the present application, the N1 interface session management container includes a session migration command, the session migration command including a migration cause and/or a protocol configuration option, the protocol configuration option including a session network address lifetime.

The first network side device may control the first terminal to migrate to the second network slice in the first session in the first network slice according to the information.

In one embodiment of the present application, in the case that the session migration information includes an N1 interface session management container and a session management function reassignment request, the method may further include the steps of:

the first network side device transmits the N1 interface session management container to a target session management function corresponding to the session management function reassignment request.

In the case that the session migration information includes the N1 interface session management container and the session management function reassignment request, the first network side device may transfer the N1 interface session management container to the target session management function corresponding to the session management function reassignment request, so that the target session management function performs session management.

In one embodiment of the present application, the determining, by the first network side device, a second network slice with a migration mapping relationship corresponding to a first network slice accessed by the first terminal includes:

the first network side device determines a second network slice with a migration mapping relation corresponding to the first network slice according to first migration mapping information of the first terminal, which is stored in advance and allows access to the network slice;

The allowed access network slice of the first terminal comprises a first network slice.

In this embodiment of the present application, the first network side device may obtain and store, in advance, first migration mapping information of Allowed access network slices (Allowed nsai) of the first terminal, where the first migration mapping information may include network slices with migration mapping relationships corresponding to each Allowed access network slice of the first terminal, and network slices with migration mapping relationships corresponding to different Allowed access network slices may be the same or different. The allowed access network slice of the first terminal comprises a first network slice.

The first network side device can determine a second network slice with a migration mapping relation corresponding to the first network slice according to first migration mapping information of the first terminal, which is stored in advance and allows access to the network slice.

In the first migration mapping information of the first terminal, which is stored in advance and allows access to the network slice, a second network slice with a migration mapping relation corresponding to the first network slice can be accurately determined. And the first migration mapping information is obtained and stored in advance, so that the second network slice with the migration mapping relation corresponding to the first network slice can be determined quickly.

In one embodiment of the present application, the first migration map information is determined based on network slice selection information.

The network slice selection information includes at least one of:

information of Allowed access network slice (Allowed NSSAI) of the first terminal;

migration mapping information (Secondary NSSAI mapping corresponding to Allowed NSSAI) of the first terminal for allowing access to the network slice;

an access management function set (AMF set);

access management function address information (AMF address list);

network slice instance identification (NSI-ID).

In this embodiment of the present application, the first network side device may obtain network slice selection information, where the network slice selection information may include migration mapping information of the first terminal that allows access to the network slice, and according to the information, may determine first migration mapping information of the first terminal that allows access to the network slice.

In one embodiment of the present application, the network slice selection information is determined according to the received access management function redirection information for the first terminal sent by the third network side device.

In this embodiment of the present application, when receiving a network slice registration request sent by a first terminal, the first network side device may obtain subscription information of the first terminal through the UDM, send a network slice selection request to a fourth network side device, such as a network slice selection function (Network Slice Selection Function, NSSF), based on the subscription information of the first terminal, and the fourth network side device returns network slice selection information, where the first network side device obtains the network slice selection information and determines first migration mapping information of the first terminal that allows access to a network slice based on the network slice selection information.

When the first terminal is initially registered, if a network slice registration request is sent to third network side equipment, the third network side equipment acquires subscription information of the first terminal through UDM, sends a network slice selection request to fourth network side equipment based on the subscription information of the first terminal, the fourth network side equipment returns network slice selection information, and the third network side equipment acquires the network slice selection information. If the third network side device is not the service access management function, the first network side device is the service access management function, the third network side device may initiate a redirection procedure, and send the access management function redirection information for the first terminal to the first network side device. Network slice selection information may be included in the access management redirection information. The third network side device is a source device for redirecting the access management function, and the first network side device is a target device for redirecting the access management function. The first network side device can obtain the network slice selection information and determine the first migration mapping information of the first terminal allowing access to the network slice based on the network slice selection information.

In one embodiment of the present application, the network slice selection information is information sent by the fourth network side device after sending the network slice selection request to the fourth network side device, and/or the network slice selection information is determined according to a migration mapping relationship of network slices in the network.

The network slice selection request may be sent by the first network side device to the fourth network side device, or may be sent by the third network side device to the fourth network side device. The fourth network side device may specifically select a function for the network slice. The fourth network side device has a migration mapping relation of network slices in the network, can select a second network slice with the migration mapping relation for the first network slice after determining the first network slice, and transmits the second network slice to the first network side device or to the third network side device after placing the second network slice in the network slice selection information, and then the third network side device redirects information to the first network side device through an access management function.

The network slice selection request carries at least one of the following information:

information of a first terminal requesting access to a network slice;

the method comprises the steps of signing network slice information of a first terminal;

tracking area indication information.

The fourth network side device can accurately determine the network slice selection information according to the information carried in the network slice selection request.

In one embodiment of the present application, the network slice selection request is sent to the fourth network side device after receiving the network slice registration request of the first terminal and obtaining the subscription information of the first terminal.

As described above, the network slice selection request may be sent to the fourth network side device after the first network side device receives the network slice registration request of the first terminal and obtains the subscription information of the first terminal, or may be sent to the fourth network side device after the third network side device receives the network slice registration request of the first terminal and obtains the subscription information of the first terminal.

In one embodiment of the present application, the method may further comprise the steps of:

step one: the first network side equipment receives second migration mapping information which is transmitted by the fifth network side equipment and allows access to the network slice of the first terminal;

step two: the first network side equipment determines first migration mapping information based on the second migration mapping information;

the second migration mapping information is sent by the fifth network side equipment when the wireless access network switching request is received.

For convenience of description, the above two steps are described in combination.

In this embodiment of the present application, the first network side device may determine and store, in advance, first migration mapping information of a first terminal that allows access to a network slice, and according to the first migration mapping information, may determine a second network slice with a migration mapping relationship corresponding to the first network slice, so as to perform session migration between network slices.

Because of the mobility of the terminals, the location of the first terminal may change, so that the accessed radio access network (Radio Access Network, RAN) needs to be handed over, and thus the AMF also changes, the source AMF may send second migration map information of the first terminal allowing access to the network slice to the target AMF.

That is, the first network side device may receive second migration mapping information of the first terminal allowed to access the network slice, which is sent by the fifth network side device, and determine the first migration mapping information based on the second migration mapping information.

The fifth network side device may be a source AMF before the radio access network is switched, the first network side device may be a target AMF after the radio access network is switched, and the fifth network side device may send the second migration mapping information to the first network side device when receiving the radio access network switching request.

The first network side device determines first migration mapping information based on the second migration mapping information, which may specifically be:

the first network side equipment determines the second migration mapping information as first migration mapping information under the condition that migration mapping information of the first terminal allowing access to the network slice is not stored.

The first network side device may directly determine, as the first migration mapping information, the second migration mapping information of the first terminal allowed to access the network slice sent by the fifth network side device, and store the first migration mapping information, without storing any migration mapping information of the first terminal allowed to access the network slice.

The first network side device determines first migration mapping information based on the second migration mapping information, which may specifically be:

and under the condition that the first migration mapping information is stored in the first network side equipment, if the first migration mapping information is different from the second migration mapping information, determining the first migration mapping information according to whether the first migration mapping information contains migration mapping information corresponding to all the allowed access network slices of the first terminal.

That is, the first network side device may have stored the first migration mapping information of the first terminal allowing access to the network slice before, if the first migration mapping information is the same as the second migration mapping information, the first migration mapping information may be kept unchanged, and the first migration mapping information may be directly used when session migration between network slices is performed subsequently.

If the first migration mapping information is different from the second migration mapping information, whether the first migration mapping information contains migration mapping information corresponding to all allowed access network slices of the first terminal or not can be judged, and the first migration mapping information is determined according to a judging result.

Specifically, the first network side device keeps the first migration mapping information unchanged when the first migration mapping information contains migration mapping information of all allowed access network slices of the first terminal;

or,

and under the condition that the first migration mapping information comprises migration mapping information of a part of the first terminal which is allowed to access the network slice, the first network side equipment acquires new migration mapping information of the first terminal which is allowed to access the network slice through the fourth network side equipment, and updates the first migration mapping information into the new migration mapping information.

That is, if the first network side device stores the first migration mapping information, the first migration mapping information is different from the second migration mapping information, but the first migration mapping information includes migration mapping information of all allowed access network slices of the first terminal, the first migration mapping information can be kept unchanged, and the first migration mapping information can be directly used when session migration between network slices is performed subsequently.

If the first migration mapping information is different from the second migration mapping information, but the first migration mapping information includes migration mapping information of a part of the first terminal allowed to access the network slice, new migration mapping information of the first terminal allowed to access the network slice can be obtained through the fourth network side device, the first migration mapping information is updated to be the new migration mapping information, and the new migration mapping information is directly used when session migration between the network slices is carried out subsequently. No access management function redirection is required.

The first network side equipment obtains and stores the first migration mapping information of the first terminal allowing access to the network slices in advance, and is beneficial to smooth proceeding of session migration among subsequent network slices.

The technical solutions provided by the embodiments of the present application are described in detail above, and for convenience of understanding, the technical solutions provided by the embodiments of the present application are described again by way of specific examples.

For example, as shown in fig. 3, the network slice migration mapping relationship may be determined when the network slice is initially registered:

step 1: the terminal initiates an initial network slice registration request, which can carry information of requesting to access the network slice, namely, requested NSSAI;

step 2: if the current source AMF needs to acquire the subscription information of the terminal to perform redirection of the access management function, the source AMF may initiate a subscription information acquisition request, such as nudm_sdm_get, to the UDM to request to acquire the subscription information of the terminal;

step 3: the UDM returns the subscription information of the terminal;

step 4: the source AMF sends a network slice selection request, such as an nnssf_nsselection_get request, to the NSSF, which may carry information such as Requested nsai, subscription network slice (sub-subscription NSSAI), TAI, etc.;

step 5: NSSF returns source AMF network slice selection information including, but not limited to, one or more of the following: secondary NSSAI mapping corresponding to the Allowed NSSAI, the AMF Set, the AMF address list and the NSI-ID;

Step 6: the source AMF performs AMF redirection and communicates NS information to the target AMF including, but not limited to, one or more of the following: allowed NSSAI, secondary NSSAI mapping corresponding to Allowed NSSAI, AMF Set, AMF address list, NSI-ID. In this step, the target AMF stores Secondary NSSAI mapping corresponding to the Allowed NSSAI, that is, migration mapping information of the Allowed access network slice of the terminal;

step 7: executing the rest registration flow;

step 8: the target AMF transmits registration response information to the terminal, which may include at least one of the following information: the information of the Allowed access network slice of the terminal, namely the information of the UE Allowed NSSAI, and the migration mapping information of the Allowed access network slice of the terminal, namely Secondary NSSAI mapping information corresponding to the Allowed NSSAI.

Example two, as shown in fig. 4, the inter-network-slice PDU session migration flow-SMF modification (supporting SSC Mode2 and SSC Mode 3):

step 1: AMF makes a decision to carry out PDU session migration among network slices according to the network deployment condition, and migrates to secondary S-NSSAI;

step 2,3: AMF triggers PDU session Modification flow, AMF can obtain context information of the first PDU session through Nsmf_PDUSion_SMContextStatusNotify;

For the case of supporting service continuity SSC Mode 2:

step 4a: a first PDU session release based on a source UPF;

step 5a: according to the context information of the first PDU session acquired in the step 2,3, the terminal initiates a new PDU session connection, directly points to the second S-NSSAI, and establishes a second PDU session based on the target UPF;

for the case of supporting service continuity SSC Mode 3:

step 4b: the SMF transmits session migration information to the AMF through Namf_communication_N1N2MessageTransferto inform the first PDU that the session needs to be migrated, wherein the session migration information comprises but is not limited to context information of the PDU session, PDU session identification information, N1 SM container, SMF relocation request and the like;

the PDU session identity indicates the first PDU session to migrate and the SMF reassignment request indicates whether the SMF also needs to migrate. The N1 SM Container includes PDU Session Modification Command including a migration Cause (Cause), a protocol configuration option (Protocol Configuration Option, PCO), the protocol configuration option including a session network address lifetime, PDU Session Address Lifetime value;

step 5b: the AMF transmits the PDU session migration command to the terminal through NAS information, and the terminal responds;

Step 6,7: AMF transmits N1 SM content to target SMF through Nsmmf_PDUSion_UpdateSMContext;

step 8: the terminal establishes a PDU session connection (access to the same DN) through the new anchor point, i.e. establishes a third PDU session based on the target UPF. The terminal starts using the IP address/prefix associated with the third PDU session for all new traffic and can also actively move the existing traffic flow (if possible) from the old PDU session (first PDU session) to the new PDU session (third PDU session). After the new session is established, uplink and downlink data are transmitted from the new PDU session and are not transmitted from the old PDU session any more;

step 9: the terminal releases the first PDU session based on the source UPF.

Example three, as shown in fig. 5, determining a migration mapping relationship in the PDU session migration flow between network slices—inter RAN:

step 1: the source RAN determines to execute a switching flow, namely an N2 relocation flow;

step 2: the source RAN sends a switching request to the source AMF;

step 3: in the selection process of the target AMF, the source AMF sends second migration mapping information of the terminal which is stored in the source AMF and allows access to the network slice, namely the corresponding relation between the second NSSAI and the Allowed NSSAI to the target AMF;

after the target AMF receives the information, the second migration mapping information is compared with the first migration mapping information of the terminal which is stored by the target AMF and allows access to the network slice:

If the two are consistent, continuing to execute the step 4;

if the first migration mapping information stored in the target AMF is inconsistent with the second migration mapping information, but the first migration mapping information stored in the target AMF contains migration mapping relations corresponding to all Allowed NSSAI, deleting the second migration mapping information of the source AMF by the target AMF, executing the step 4, and using the first migration mapping information stored in the target AMF for subsequent continuity management;

if the two pieces of migration mapping information are inconsistent, but the first migration mapping information stored by the target AMF cannot contain all migration mapping relations of the Allowed NSSAI, the target AMF acquires new migration mapping information through NSSF in a registration flow after the RAN handover is completed, and updates the first migration mapping information; (in this registration procedure, AMF redirection is not required);

step 4: the rest RAN switching flows;

step 5,6: similar to the mobile flow without the terminal, when the target AMF finds that the current SLA is not satisfied or the CN is not loaded enough, the session migration between the network slices is triggered.

Through the scheme, the embodiment of the application realizes session migration among network slices, and can effectively ensure the continuity of terminal services.

The technical solution of the embodiment of the present application may be applied to a 5g+ system, where the control of network access management and session management is not limited to network slicing application, for example, the control may also play a reference role for a new common network (New Public Network, NPN), multi-access edge computing (Multi-access Edge Computing, MEC), etc.

According to the session migration control method provided by the embodiment of the application, the execution subject can be the session migration control device. In the embodiment of the present application, a session migration control device executes a session migration control method by using a session migration control device as an example, and the session migration control device provided in the embodiment of the present application is described.

Referring to fig. 6, the session migration control apparatus 600 includes the following modules:

a first determining module 610, configured to determine a second network slice with a migration mapping relationship corresponding to a first network slice accessed by a first terminal;

the control module 620 is configured to control the first terminal to migrate a first session in the first network slice to the second network slice.

After the device provided by the embodiment of the application is used for determining the second network slice with the migration mapping relation corresponding to the first network slice accessed by the first terminal, the first session of the first terminal in the first network slice can be controlled to migrate to the second network slice, the second network slice continuously provides services for the terminal, session migration among different network slices is realized, service interruption provided for the terminal is avoided, and terminal service continuity is ensured.

In one embodiment of the present application, the control module 620 is configured to:

And sending first session migration indication information to the first terminal, wherein the first session migration indication information is used for indicating the first terminal to establish a second session in the second network slice after releasing the first session in the first network slice.

In one embodiment of the present application, the control module 620 is configured to:

and sending second session migration indication information to the first terminal, wherein the second session migration indication information is used for indicating the first terminal to release the first session in the first network slice after the third session is established in the second network slice.

In one embodiment of the present application, the third session is different from the session anchor point corresponding to the first session.

In a specific embodiment of the present application, the network address associated with the third session is used for transmission of the new traffic flow.

In a specific embodiment of the present application, the session migration control apparatus 600 further includes a sending module, configured to:

the method includes transmitting context information of a first session to a first terminal before controlling the first terminal to migrate the first session in the first network slice into a second network slice.

In a specific embodiment of the present application, the session migration control apparatus 600 further includes a second determining module, configured to:

Before determining a second network slice with a migration mapping relation corresponding to a first network slice accessed by a first terminal, determining a first session according to network deployment information;

or,

and determining the first session according to the received session migration information sent by the second network side equipment.

In one embodiment of the present application, the session migration information includes information of at least one of:

context information of the first session;

identification information of the first session;

an N1 interface session management container;

the session management function reassigns the request.

In one embodiment of the present application, the N1 interface session management container includes a session migration command, the session migration command including a migration cause and/or a protocol configuration option, the protocol configuration option including a session network address lifetime.

In a specific embodiment of the present application, the session migration control apparatus 600 further includes a delivery module, configured to:

and when the session migration information comprises an N1 interface session management container and a session management function reassignment request, transmitting the N1 interface session management container to a target session management function corresponding to the session management function reassignment request.

In a specific embodiment of the present application, the first determining module 610 is configured to:

determining a second network slice with a migration mapping relation corresponding to the first network slice according to first migration mapping information of the pre-stored first terminal allowing access to the network slice;

the allowed access network slice of the first terminal comprises a first network slice.

In one embodiment of the present application, the first migration map information is determined based on network slice selection information.

In one embodiment of the present application, the network slice selection information includes at least one of:

information of the first terminal allowing access to the network slice;

migration mapping information of the first terminal allowing access to the network slice;

accessing a management function set;

accessing management function address information;

network slice instance identification.

In a specific embodiment of the present application, the network slice selection information is determined according to the received access management function redirection information for the first terminal sent by the third network side device.

In a specific embodiment of the present application, the network slice selection information is information sent by the fourth network side device after sending the network slice selection request to the fourth network side device, and/or the network slice selection information is determined according to a migration mapping relationship of network slices in the network.

In one embodiment of the present application, the network slice selection request carries at least one of the following information:

information of a first terminal requesting access to a network slice;

the method comprises the steps of signing network slice information of a first terminal;

tracking area indication information.

In a specific embodiment of the present application, the network slice selection request is sent to the fourth network side device after receiving a network slice registration request of the first terminal and obtaining subscription information of the first terminal.

In a specific embodiment of the present application, the session migration control apparatus 600 further includes:

the receiving module is used for receiving second migration mapping information which is transmitted by the fifth network side equipment and allows the first terminal to access the network slice;

a third determining module, configured to determine first migration mapping information based on the second migration mapping information;

the second migration mapping information is sent by the fifth network side equipment when the wireless access network switching request is received.

In a specific embodiment of the present application, the third determining module is configured to:

and determining the second migration mapping information as the first migration mapping information in the case that the migration mapping information of the first terminal allowing access to the network slice is not stored.

In a specific embodiment of the present application, the third determining module is configured to:

and under the condition that the first migration mapping information is stored, if the first migration mapping information is different from the second migration mapping information, determining the first migration mapping information according to whether the first migration mapping information contains migration mapping information corresponding to all the allowed access network slices of the first terminal.

In a specific embodiment of the present application, the third determining module is configured to:

under the condition that the first migration mapping information contains migration mapping information of all allowed access network slices of the first terminal, keeping the first migration mapping information unchanged;

or,

and under the condition that the first migration mapping information comprises migration mapping information of a part of the allowed access network slice of the first terminal, acquiring new migration mapping information of the allowed access network slice of the first terminal through fourth network side equipment, and updating the first migration mapping information into the new migration mapping information.

The session migration control apparatus 600 provided in this embodiment of the present application can implement each process implemented by the method embodiments shown in fig. 2 to 5, and achieve the same technical effects, and for avoiding repetition, a detailed description is omitted herein.

As shown in fig. 7, the embodiment of the present application further provides a network side device 700, including a processor 701 and a memory 702, where the memory 702 stores a program or an instruction that can be executed on the processor 701, and the program or the instruction implements each step of the above-mentioned session migration control method embodiment when executed by the processor 701, and can achieve the same technical effect, so that repetition is avoided, and no redundant description is given here.

Specifically, the embodiment of the application also provides network side equipment. As shown in fig. 8, the network side device 800 includes: a processor 801, a network interface 802, and a memory 803. The network interface 802 is, for example, a common public radio interface (common public radio interface, CPRI).

Specifically, the network side device 800 of the embodiment of the present invention further includes: instructions or programs stored in the memory 803 and capable of running on the processor 801, the processor 801 calls the instructions or programs in the memory 803 to execute the method executed by each module shown in fig. 6, and achieve the same technical effect, so that repetition is avoided, and therefore, the description is omitted herein.

The embodiment of the present application further provides a readable storage medium, where a program or an instruction is stored on the readable storage medium, and when the program or the instruction is executed by a processor, the processes of the embodiments of the methods shown in fig. 2 to fig. 5 are implemented, and the same technical effects can be achieved, so that repetition is avoided, and no further description is provided herein.

Wherein the processor is a processor in the terminal described in the above embodiment. The readable storage medium includes computer readable storage medium such as computer readable memory ROM, random access memory RAM, magnetic or optical disk, etc.

The embodiments of the present application further provide a computer program/program product, where the computer program/program product is stored in a storage medium, and the computer program/program product is executed by at least one processor to implement each process of the method embodiments shown in fig. 2 to 5 and achieve the same technical effects, and are not repeated herein.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of the present application is not limited to performing the functions in the order shown or discussed, but may also include performing the functions in a substantially simultaneous manner or in an opposite order depending on the functions involved, e.g., the described methods may be performed in an order different from that described, and various steps may also be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solutions of the present application may be embodied essentially or in a part contributing to the prior art in the form of a computer software product stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk), comprising several instructions for causing a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to perform the method described in the embodiments of the present application.

The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those of ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are also within the protection of the present application.

Claims (24)

1. A session migration control method, comprising:

the method comprises the steps that first network side equipment determines a second network slice with a migration mapping relation corresponding to a first network slice accessed by a first terminal;

the first network side device controls the first terminal to migrate a first session in the first network slice to the second network slice.

2. The method of claim 1, wherein the first network side device controlling migration of the first session of the first terminal in the first network slice into the second network slice comprises:

the first network side device sends first session migration indication information to the first terminal, wherein the first session migration indication information is used for indicating the first terminal to release a first session in the first network slice, and then a second session is established in the second network slice.

3. The method of claim 1, wherein the first network side device controlling migration of the first session of the first terminal in the first network slice into the second network slice comprises:

the first network side equipment sends second session migration indication information to the first terminal, wherein the second session migration indication information is used for indicating the first terminal to establish a third session in the second network slice and then releasing the first session in the first network slice.

4. A method according to claim 3, wherein the third session is different from the session anchor point corresponding to the first session.

5. A method according to claim 3, characterized in that the network address associated with the third session is used for the transmission of new traffic streams.

6. The method of claim 1, wherein prior to the first network side device controlling the first terminal to migrate a first session in the first network slice into the second network slice, further comprising:

and the first network side equipment sends the context information of the first session to the first terminal.

7. The method of claim 1, wherein before the first network side device determines the second network slice with the migration mapping relationship corresponding to the first network slice accessed by the first terminal, the method further comprises:

the first network side equipment determines the first session according to network deployment information;

or,

the first network side equipment determines the first session according to the received session migration information sent by the second network side equipment.

8. The method of claim 7, wherein the session migration information includes information of at least one of:

Context information of the first session;

identification information of the first session;

an N1 interface session management container;

the session management function reassigns the request.

9. The method according to claim 8, wherein the N1 interface session management container comprises a session migration command, the session migration command comprising a migration cause and/or a protocol configuration option, the protocol configuration option comprising a session network address lifetime.

10. The method according to claim 8, wherein in case the session migration information comprises the N1 interface session management container and the session management function reassignment request, further comprising:

and the first network side equipment transmits the N1 interface session management container to a target session management function corresponding to the session management function reassignment request.

11. The method according to any one of claims 1 to 10, wherein the determining, by the first network side device, a second network slice with a migration mapping relationship corresponding to a first network slice accessed by the first terminal includes:

the first network side device determines a second network slice with a migration mapping relation corresponding to the first network slice according to first migration mapping information of a prestored first terminal allowing access to the network slice;

The allowed access network slice of the first terminal includes the first network slice.

12. The method of claim 11, wherein the first migration-mapping information is determined based on network slice selection information.

13. The method of claim 12, wherein the network slice selection information comprises at least one of:

information of the first terminal allowing access to a network slice;

migration mapping information of the first terminal allowing access to the network slice;

accessing a management function set;

accessing management function address information;

network slice instance identification.

14. The method of claim 12, wherein the network slice selection information is determined based on received access management function redirection information for the first terminal sent by the third network side device.

15. The method of claim 12, wherein the network slice selection information is information sent by the fourth network side device after sending a network slice selection request to the fourth network side device, and/or the network slice selection information is determined according to a migration mapping relationship of network slices in a network.

16. The method of claim 15, wherein the network slice selection request carries at least one of the following information:

the first terminal requests to access the information of the network slice;

the information of the contracted network slice of the first terminal;

tracking area indication information.

17. The method of claim 15, wherein the network slice selection request is sent to the fourth network side device after receiving a network slice registration request of the first terminal and acquiring subscription information of the first terminal.

18. The method as recited in claim 11, further comprising:

the first network side equipment receives second migration mapping information which is transmitted by fifth network side equipment and allows access to network slices of the first terminal;

the first network side equipment determines the first migration mapping information based on the second migration mapping information;

the second migration mapping information is sent by the fifth network side equipment when receiving a radio access network switching request.

19. The method of claim 18, wherein the first network side device determining the first migration-map information based on the second migration-map information comprises:

And the first network side equipment determines the second migration mapping information as the first migration mapping information under the condition that the migration mapping information of the first terminal allowing access to the network slice is not stored.

20. The method of claim 18, wherein the first network side device determining the first migration-map information based on the second migration-map information comprises:

and under the condition that the first migration mapping information is stored in the first network side device, if the first migration mapping information is different from the second migration mapping information, determining the first migration mapping information according to whether the first migration mapping information contains migration mapping information corresponding to all the allowed access network slices of the first terminal.

21. The method according to claim 20, wherein the first network side device determines the first migration-mapping information according to whether the first migration-mapping information includes migration-mapping information of all allowed access network slices of the first terminal, including:

the first network side equipment keeps the first migration mapping information unchanged under the condition that the first migration mapping information contains migration mapping information of all allowed access network slices of the first terminal;

Or,

and under the condition that the first migration mapping information contains migration mapping information of the part of the first terminal which is allowed to access the network slice, the first network side equipment acquires new migration mapping information of the first terminal which is allowed to access the network slice through fourth network side equipment, and updates the first migration mapping information into the new migration mapping information.

22. A session migration control apparatus, comprising:

the first determining module is used for determining a second network slice with a migration mapping relation corresponding to a first network slice accessed by the first terminal;

and the control module is used for controlling the first session of the first terminal in the first network slice to migrate into the second network slice.

23. A network side device comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the session migration control method according to any one of claims 1 to 21.

24. A readable storage medium, wherein a program or instructions is stored on the readable storage medium, which when executed by a processor, implements the steps of the session migration control method according to any one of claims 1 to 21.