CN109219111B

CN109219111B - Slice selection method and device

Info

Publication number: CN109219111B
Application number: CN201710530394.5A
Authority: CN
Inventors: 朱方园; 余芳; 李岩; 倪慧
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2017-06-29
Filing date: 2017-06-29
Publication date: 2020-09-04
Anticipated expiration: 2037-06-29
Also published as: WO2019001204A1; CN109219111A

Abstract

The application relates to the technical field of wireless communication, and provides a slice selection method, which comprises the following steps: the first access and mobility management functional entity receiving a registration request message including a requested NSSAI from the terminal device, the requested NSSAI including at least a first S-NSSAI, the first S-NSSAI being an S-NSSAI not supported by the first access and mobility management functional entity; acquiring attribute information of a first S-NSSAI, and providing a service corresponding to the first S-NSSAI for the terminal equipment by using a slice corresponding to a second S-NSSAI according to the attribute information; obtaining an NSSP comprising an association between the application and a second S-NSSAI; and sending a registration acceptance message to the terminal equipment, wherein the registration acceptance message comprises the allowed NSSAI and the NSSP of the terminal equipment, and the allowed NSSAI comprises the second S-NSSAI. By the scheme provided by the embodiment, the service corresponding to the first S-NSSAI that is not supported is not abandoned, but is provided instead by the slice corresponding to the second S-NSSAI. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

Description

Slice selection method and device

Technical Field

The present application relates to the field of wireless communications technologies, and in particular, to a slice selection method and apparatus.

Background

Fifth generation (the 5)^thgeneration, 5G) communication era will have billions of internet of things devices accessing to the network, and the demands of different types of application scenarios on the network are differentiated. The network slicing technology provides mutually isolated network environments for different application scenes in a mode of simulating an independent logic network on the same network infrastructure, so that different application scenes can customize network functions and characteristics according to respective requirements, and requirements of different services are met.

A terminal device may access one or more network slices. When a network slice is deployed in a network and a terminal device needs to access to a certain slice, the terminal device may provide requested Network Slice Selection Assistance Information (NSSAI) to the network, so that the network selects an appropriate access and mobility management function (AMF) entity for the terminal device to connect to an appropriate network slice. NSSAI is a set of Single Network Slice selection assistance information (S-NSSAI).

In the prior art, if an AMF entity in a Public Land Mobile Network (PLMN) can only support a part of S-NSSAI requested by a terminal device, the terminal device needs to provide auxiliary information to indicate which S-NSSAI corresponds to a slice type that the terminal device prefers to access. The core network selects an AMF entity for providing service for the terminal equipment according to the auxiliary information. For example, as shown in fig. 1, if the first AMF entity AMF-1 supports S-NSSAI 1,2,3, the second AMF entity AMF-2 supports S-NSSAI3, 4, the type in the NSSAI requested by the terminal equipment (UE) is S-NSSAI2,3,4 and the terminal equipment prefers to access S-NSSAI 4, the network may select the second AMF entity AMF-2 as the AMF entity that initially serves the terminal equipment.

However, this may cause the service corresponding to the abandoned S-NSSAI (e.g., S-NSSAI2) to be subsequently unavailable, which may affect the service experience of the terminal device.

Disclosure of Invention

The application describes a slice selection method and apparatus.

In one aspect, an embodiment of the present application provides a slice selection method, including: the first access and mobility management function entity (e.g., the first AMF entity) receives a registration request message from the terminal device, where the registration request message includes NSSAI corresponding to a slice to which the terminal device requests access. The NSSAI corresponding to the slice requesting access at least comprises a first S-NSSAI, wherein the first S-NSSAI is an S-NSSAI which is not supported by the first access and mobility management function entity. And the first access and mobility management functional entity acquires the attribute information of the first S-NSSAI and provides the service corresponding to the first S-NSSAI for the terminal equipment by using the slice corresponding to the second S-NSSAI according to the attribute information. The first access and mobility management functional entity obtains an NSSP comprising an association between the application and the second S-NSSAI. The first access and mobility management functional entity sends a registration acceptance message to the terminal equipment, wherein the registration acceptance message comprises NSSAI and NSSP corresponding to the slice which the terminal equipment is allowed to access, and the NSSAI corresponding to the slice which is allowed to access comprises second S-NSSAI.

According to the slice selection scheme, the first AMF entity obtains attribute information, and when the first AMF entity does not support the first S-NSSAI, the slice corresponding to the second S-NSSAI is used for providing the service corresponding to the first S-NSSAI for the terminal equipment according to the attribute information. In this way, services corresponding to the first S-NSSAI that are not supported are not discarded, but instead provided by slices corresponding to the second S-NSSAI. Furthermore, the NSSP rule into the NSSP acquired by the first access and mobility management functional entity is associated with the second S-NSSAI. Therefore, after receiving the NSSP rule, the terminal device may perceive that the service corresponding to the first S-NSSAI is provided instead of the slice corresponding to the second S-NSSAI. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

In one possible design, obtaining the attribute information of the first S-NSSAI may be implemented as follows: the first access and mobility management function entity obtains attribute information of the first S-NSSAI from a user data management device (e.g., UDM device) or a policy control function device (e.g., PCF device). For example, the first access and mobility management functional entity obtains the slice subscription policy information from the user data management device or the policy control functional device, and obtains the attribute information of the first S-NSSAI from the slice subscription policy information.

In one possible design, acquiring NSSP may be accomplished by: the first access and mobility management functional entity sends the indication information to the policy control functional device, and requests the policy control functional device to update the NSSP related to the first S-NSSAI. The first access and mobility management function entity receives an NSSP from a policy control function device.

In one possible design, the method further includes: and the first access and mobility management functional entity adds indication information in the context of the terminal equipment, wherein the indication information is used for indicating the first access and mobility management functional entity to provide the service corresponding to the first S-NSSAI for the terminal equipment by using the slice corresponding to the second S-NSSAI. Therefore, through the context transfer, other access and mobility management functional entities can acquire the indication information, so as to judge whether the access and mobility management functional entities are suitable for serving the terminal equipment, thereby improving the service experience of the user.

In one possible design, the method further includes: the first access and mobility management function entity receiving a request message from a second access and mobility management function entity (e.g., a second AMF entity) to request a context of the terminal device; and the first access and mobility management functional entity sends the context of the terminal equipment to the second access and mobility management functional entity, wherein the context comprises the indication information. Therefore, according to the scheme of the application, after the terminal device moves, the second AMF entity requests the first AMF entity before moving for the context of the terminal device, so as to learn that the second AMF entity is not the most suitable AMF entity, and if other access and mobility management functional entities (e.g., a third AMF entity) capable of supporting the first S-NSSAI exist in the PLMN network currently visited by the terminal device, the terminal device is redirected to the third AMF entity supporting the first S-NSSAI, and the "most suitable" third AMF entity provides services for the terminal device. Therefore, although the first AMF entity in the first PLMN does not support the first S-NSSAI, the service corresponding to the first S-NSSAI can still be implemented in the second PLMN after the terminal device moves. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

In another aspect, the present application further discloses a slice selection method, including: and the second access and mobility management functional entity receives a registration request message, wherein the registration request message comprises NSSAI corresponding to the slice which is allowed to be accessed by the terminal equipment and the temporary identifier of the terminal equipment, and the NSSAI corresponding to the slice which is allowed to be accessed comprises second S-NSSAI. And the second access and mobility management functional entity acquires the context of the terminal equipment from the first access and mobility management functional entity according to the temporary identifier, wherein the context comprises indication information. The indication information is used for indicating the first access and mobility management functional entity to use the slice corresponding to the second S-NSSAI to provide the service corresponding to the first S-NSSAI for the terminal equipment. If the second access and mobility management functional entity does not support the first S-NSSAI, but there are other access and mobility management functional entities that can support the first S-NSSAI in the PLMN network currently visited by the terminal device, the second access and mobility management functional entity redirects the terminal device to a third access and mobility management functional entity (e.g., a third AMF entity) that supports the first S-NSSAI.

According to the slice selection scheme, after the terminal device moves, the second AMF entity requests the first AMF entity before moving for the context of the terminal device, so that the fact that the second AMF entity is not the most suitable AMF entity is known, if other access and mobility management functional entities capable of supporting the first S-NSSAI exist in a PLMN (public land Mobile network) currently visited by the terminal device, the terminal device is redirected to a third AMF entity supporting the first S-NSSAI, and the most suitable third AMF entity provides services for the terminal device. Therefore, although the first AMF entity in the first PLMN does not support the first S-NSSAI, the service corresponding to the first S-NSSAI can still be implemented in the second PLMN after the terminal device moves. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

In one possible design, the method further includes: and the second access and mobility management functional entity sends the context of the terminal equipment to the third access and mobility management functional entity, wherein the context comprises the indication information. Thus, the third access and mobility management function entity receiving the indication can send the indication to the PCF device and request the PCF device to update the NSSP relating to the second S-NSSAI. Thus, the updated NSSP is restored to the "real" content. Subsequently, the terminal device may associate the application with the S-NSSAI according to the updated NSSP, thereby obtaining a complete service. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

In another aspect, the present application further discloses a slice selection method, including: and the third access and mobility management functional entity acquires the context of the terminal equipment, wherein the context comprises the indication information. The indication information is used for indicating the first access and mobility management functional entity to use the slice corresponding to the second S-NSSAI to provide the service corresponding to the first S-NSSAI for the terminal device. The third access and mobility management function entity sends an indication to the policy control function device requesting the policy control function device to update the NSSP relating to the second S-NSSAI. The updated NSSP includes an association between the application and the first S-NSSAI. The third access and mobility management function entity receives the updated NSSP from the policy control function device.

According to the slice selection scheme, after the terminal device moves, the third AMF entity which is most suitable provides service for the terminal device. The third AMF entity obtains the context containing the indication information, sends the indication information to the PCF equipment and requests the PCF equipment to update the NSSP related to the second S-NSSAI. Thus, the updated NSSP is restored to the "real" content. Subsequently, the terminal device may associate the application with the S-NSSAI according to the updated NSSP, thereby obtaining a complete service. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

In another aspect, the present application also discloses a slice selection method, including: the policy control function device receives indication information from the first access and mobility management function entity. The indication information is used for indicating the first access and mobility management functional entity to use the slice corresponding to the second S-NSSAI to provide the service corresponding to the first S-NSSAI for the terminal equipment. And the policy control function device updates the NSSP related to the first S-NSSAI according to the indication information and sends the updated first NSSP to the first access and mobility management function entity. Wherein the updated first NSSP includes an association between the application and the second S-NSSAI.

According to the above slice selection scheme, when the first AMF entity does not support the first S-NSSAI and provides the terminal device with the service corresponding to the first S-NSSAI using the slice corresponding to the second S-NSSAI, the PCF device updates the NSSP related to the first S-NSSAI, so that the updated NSSP includes the association between the application and the second S-NSSAI. Thus, services corresponding to the first S-NSSAI that are not supported are not discarded, but instead provided by slices corresponding to the second S-NSSAI. And through the updating of the PCF equipment to the NSSP, the terminal equipment can sense that the service corresponding to the first S-NSSAI is provided by the slice corresponding to the second S-NSSAI instead. The service corresponding to NSSAI requested by the terminal equipment can be satisfied, and the service experience of the user is improved.

In one possible design, the method further includes: the policy control function device receives the indication information from the third access and mobility management function entity; the strategy control function device updates the NSSP related to the second S-NSSAI according to the indication information, wherein the updated second NSSP comprises the association between the application and the first S-NSSAI; and the policy control function device sends the updated second NSSP to a third access and mobility management function entity. Therefore, when the terminal device moves, the terminal device is served by the "most suitable" third AMF entity. The third AMF entity sends the indication information to the PCF device and requests the PCF device to update the NSSP related to the second S-NSSAI. Thus, the updated NSSP is restored to the "real" content. Subsequently, the terminal device may associate the application with the S-NSSAI according to the updated NSSP, thereby obtaining a complete service. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

In another aspect, the present application also discloses a slice selection method, including: and the terminal equipment judges whether the current position of the terminal equipment is in the service area of the first slice corresponding to the first S-NSSAI or not according to the NSSP. Wherein the NSSP includes an association between the first S-NSSAI and a service area of the first slice. And when the current position of the terminal equipment is in the service area of the first slice, the terminal equipment sends a registration request message. The registration request message carries the first S-NSSAI. The first S-NSSAI is used to select the first slice.

According to the slice selection scheme, before the terminal equipment initiates a registration request, whether the current position of the terminal equipment is in the service area of the slice corresponding to the first S-NSSAI in the requested NSSAI is judged. The first S-NSSAI is included in the NSSAI of the registration request message only if the current location of the terminal device is within the service area. Therefore, the phenomenon that the core network rejects the registration request of the terminal equipment because the core network cannot support the S-NSSAI requested by the terminal equipment is avoided, and the signaling interaction between the terminal equipment and the core network is saved.

In one possible design, the step of determining includes: and the terminal equipment periodically judges whether the base station corresponding to the current position of the terminal equipment is in the service area of the first slice. Therefore, if the location of the terminal device at the first time is not in the service area of the slice corresponding to the first S-NSSAI in the requested NSSAI, when the terminal device determines that the location of the terminal device is in the service area of the slice corresponding to the first S-NSSAI in the requested NSSAI at the subsequent second time, a new registration request can still be initiated to obtain the corresponding service.

In another aspect, an embodiment of the present application provides an access and mobility management function entity, where the session management function entity has a function of implementing a behavior of the first access and mobility management function entity, the second access and mobility management function entity, or the third access and mobility management function entity in the foregoing method. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In one possible design, the structure of the access and mobility management function entity includes a processor and a transceiver, and the processor is configured to process the first access and mobility management function entity, the second access and mobility management function entity, or the third access and mobility management function entity to perform corresponding functions in the above method. The transceiver is used for realizing communication between the first access and mobility management functional entity, the second access and mobility management functional entity or the third access and mobility management functional entity and other access and mobility management functional entities/policy control functional device/user data management device/access network device. The access and mobility management function may further comprise a memory for coupling with the processor, which holds program instructions and data necessary for the session management function.

In another aspect, an embodiment of the present application provides a policy control function device, where the policy control function device has a function of implementing a behavior of the policy control function device in the foregoing method. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In one possible design, the structure of the policy control function device includes a processor and a transceiver, and the processor is configured to process the policy control function device to perform the corresponding functions in the above method. The transceiver is used for realizing communication between the policy control function device and the access and mobility management function entity. The policy control function device may further comprise a memory for coupling with the processor, which stores program instructions and data necessary for the session management function entity.

In another aspect, an embodiment of the present application provides a terminal device, where the terminal device has a function of implementing a behavior of the terminal device in the foregoing method. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In one possible design, the terminal device includes a processor and a transceiver in its structure, and the processor is configured to process the terminal device to perform the corresponding functions in the above method. The transceiver is used for realizing communication between the terminal equipment and the access and mobility management function entity/access network equipment. The terminal device may further comprise a memory for coupling with the processor, which stores program instructions and data necessary for the session management function.

In yet another aspect, the present application provides a computer-readable storage medium having stored therein instructions, which when executed on a computer, cause the computer to perform the method of the above aspects.

In yet another aspect, the present application provides a computer program product containing instructions which, when executed on a computer, cause the computer to perform the method of the above aspects.

In yet another aspect, the present application provides a chip system, which includes a processor, configured to support the above-mentioned access and mobility management function entity, policy control function device, or terminal device to implement the functions referred to in the above-mentioned aspects, for example, to generate or process the information referred to in the above-mentioned method. In one possible design, the system-on-chip further includes a memory for storing program instructions and data necessary for the data transmission device. The chip system may be constituted by a chip, or may include a chip and other discrete devices.

Drawings

The drawings that are required to be used in the description of the embodiments will be briefly described below.

Fig. 1 is a schematic diagram of a part of S-NSSAI in which an AMF entity can only support a terminal device request in the prior art;

FIG. 2 is a schematic diagram of a network slice based communication system to which embodiments of the present invention are applicable;

fig. 3 is a signaling interaction diagram of a slice selection method according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating reselection of an AMF entity after a terminal device moves according to an embodiment of the present invention;

fig. 5 is a signaling interaction diagram of a slice selection method according to an embodiment of the present invention;

fig. 6 to 9 are schematic flow charts of a slice selection method according to an embodiment of the present invention;

FIG. 10 is a flow chart illustrating a slice selection method according to another embodiment of the present invention;

FIGS. 11A and 11B are schematic structural diagrams of AMF entities according to embodiments of the present invention;

fig. 12A and 12B are schematic structural diagrams of a PCF entity according to an embodiment of the present invention;

fig. 13A and 13B are schematic structural diagrams of a terminal device according to an embodiment of the present invention.

Detailed Description

The 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.

The embodiment of the present application proposes a solution based on the communication system shown in fig. 2, and is applicable to implement selection of network slices in a next generation mobile network (e.g. 5G network) architecture. For example, in a 5G mobile network architecture, the control plane function and the forwarding plane function of a mobile gateway are decoupled, and the separated control plane function is merged with a conventional control network element MME of the third generation partnership project (3 GPP) and the like to form a unified control plane (control plane) entity. The user plane UPF entity can implement user plane functions (SGW-U and PGW-U) of a Serving Gateway (SGW) and a packet data network gateway (PGW). Further, the unified control plane entity may be decomposed into an access and mobility management function (AMF) entity and a Session Management Function (SMF) entity. The AMF entity may be responsible for attachment of the terminal device, mobility management, tracking area update procedure, and the like. The SMF entity may be responsible for session management of the terminal device, selection of the user plane device, reselection of the user plane device, network protocol (IP) address allocation, quality of service (QoS) control, and establishment, modification, and release of a session.

In addition, the embodiment of the application can also be applied to other communication technologies facing the future. The system architecture and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not form a limitation on the technical solution provided in the embodiment of the present application, and as a person of ordinary skill in the art knows that along with the evolution of the network architecture and the appearance of a new service scenario, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

As shown in fig. 2, an embodiment of the present application provides a communication system based on network slicing. For example, the communication system includes at least a terminal device 202, an access network device 204, and a plurality of network slices, such as: network slice 1 and network slice 2. In the following description, the description is given with an abbreviation "slice" of "network slice", and each slice may also be referred to as "slice instance" or "network slice instance", and the present application is not limited thereto.

Terminal device 202 may access one or multiple slices simultaneously. In the example of fig. 2, slice 1 and slice 2 may share part of a control plane, which may also be referred to as a shared control network function (CCNF). The control plane that slice 1 and slice 2 may share includes the AMF entity 206. Furthermore, the session management functions are slice-specific, and this part of the control functions needs to be instantiated within a slice. To achieve isolation of data routing, user plane functions also need to be instantiated within the slice. In other words, the session management functions and the user plane functions are slice-specific for implementing slice-specific services. For example, in the example of fig. 2, slice 1 includes SMF entity 208a and user plane entity 210 a; slice 2 includes SMF entity 208b and user plane entity 210 b.

The terminal device 202(terminal device) referred to in the embodiments of the present application may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem, which have wireless communication functions. The terminal device may also be referred to as a User Equipment (UE), a Mobile Station (MS), a terminal (terminal), and may further include a subscriber unit (subscriber unit), a cellular phone (cellular phone), a smart phone (smart phone), a wireless data card, a Personal Digital Assistant (PDA) computer, a tablet computer, a wireless modem (modem), a hand-held device (hand-held), a laptop computer (laptop computer), a cordless phone (cordless phone), or a Wireless Local Loop (WLL) station, a Machine Type Communication (MTC) terminal, and the like.

The access network device referred to in the embodiments of the present application is a device deployed in a wired or wireless access network to provide a wireless communication function for the terminal device 102. The access network equipment may include various forms of base stations, such as: macro base stations, micro base stations (also referred to as small stations), relay stations, access points, etc. In systems using different radio access technologies, names of devices having a base station function may be different, for example, in an LTE system, the device is called an evolved node B (eNB or eNodeB), and in a third generation (3G) system, the device is called a node B (node B). In a new generation system, called gnb (gnnodeb).

The AMF entity involved in the embodiment of the present application may be responsible for attachment, mobility management, tracking area update procedures, and the like of the terminal device. The AMF entity may also be referred to as an AMF device or an AMF network element. In the example of fig. 2, only one AMF entity is shown. However, the present invention does not limit the number of AMF entities. Different AMF entities may be connected to different slices or to the same slice.

In the example of fig. 2, slice 1 and slice 2 each comprise one SMF entity: SMF entities 208a and 208 b. The SMF entity involved in the embodiments of the present application may be responsible for session management of the terminal device, selection of the user plane entity, reselection of the user plane entity, IP address allocation, QoS control, and establishment, modification, and release of a session. The SMF entity may also be referred to as an SMF device or an SMF network element.

Furthermore, in the example of fig. 2, slice 1 and slice 2 each comprise one UPF entity: a UPF entity 210a and a UPF entity 210 b. The UPF entity 210a and the UPF entity 210b may be connected to the same or different Data Networks (DNs) for enabling data transmission of the service. The UPF entity may also be referred to as a UPF device or a UPF network element.

Optionally, the communication system further comprises a User Data Management (UDM) device 212. The UDM device 212 is used to store subscription data for the user, such as: subscription data related to mobility management and subscription data related to session management. A UDM device may also be referred to as a UDM entity or a UDM network element.

Optionally, the communication system further comprises a Policy Control Function (PCF) device 214. PCF device 214 contains the functionality of policy control and flow-based charging control. For example, PCF device 214 may implement a user subscription data management function, a policy control function, a charging policy control function, QoS control, and/or the like. A PCF device may also be referred to as a PCF entity or a PCF network element.

Under the above-mentioned communication system based on network slicing, establishing a user plane connection to a data network through slicing includes two steps: firstly, selecting an AMF entity supporting NSSAI through a registration process; second, one or more Packet Data Unit (PDU) sessions to the data network are established by slicing. That is, in order to select a suitable slice to serve the terminal device, it is first necessary to select a suitable AMF entity.

It should be noted that terminal device 202 may access one slice or multiple slices simultaneously. Each slice may provide different services. In addition, the operator may also lay out multiple slices to provide the same service to different user groups.

The type of slice may be identified by S-NSSAI. NSSAI is a collection of S-NSSAIs. Each S-NSSAI is used to assist the network in selecting a particular network slice instance. It is also possible to select the same network slice instance by different S-NSSAIs.

Under each PLMN, the terminal device 202 locally stores NSSAI (hereinafter, referred to as configured NSSAI) corresponding to the slice configured for access. In the initial registration procedure initiated to the network, the terminal device 202 may use the S-NSSAI in the configured NSSAIs as the NSSAI corresponding to the slice requested to be accessed (referred to as the requested NSSAI in the following description for short) to perform slice selection. And the access network equipment selects a proper AMF entity according to the requested NSSAI and sends an initial registration request message to the AMF entity. In the initial registration procedure, the terminal device 202 obtains and stores NSSAI (hereinafter, referred to as allowed NSSAI) corresponding to the slice allowed to be accessed under the PLMN from the core network. Each S-NSSAI of the allowed NSSAIs is valid under the registration area of the AMF that the terminal device 202 has registered. When the subsequent terminal device 202 initiates a service request, the allowed NSSAI may be provided to the network for slice selection. In addition, after the terminal device 202 successfully completes the initial registration procedure, if the core network needs to update the allowed NSSAI of the terminal device 202, the allowed NSSAI locally stored in the terminal device 202 may be updated through a network-triggered Mobility Management (MM) procedure.

A method for selecting a network slice according to an embodiment of the present application will be described below with reference to the embodiments of fig. 3 to 6.

As shown in fig. 3, in step 301, the terminal device 202 sends a registration request message to the access network device 204. Wherein, the registration request message carries the requested NSSAI.

After receiving the registration request message, the access network device 204 selects an AMF entity for the terminal device 202 according to the requested NSSAI. If no AMF entity in the current PLMN can satisfy all S-NSSAIs in the requested NSSAI, the access network device 204 selects the first AMF entity according to the local policy information.

For example, the requested NSSAI includes S-NSSAI2,3, 4. No AMF entity within the current PLMN can support S-NSSAI2,3,4 at the same time. The first AMF entity within the current PLMN supports S-NSSAI3, 4 in the requested NSSAI, but does not support S-NSSAI2 in the requested NSSAI. And the access network equipment selects the first AMF entity according to the local policy information.

The access network device 204 then sends a registration request message containing the requested NSSAI to the first AMF entity.

Step 302, after receiving the registration request message, the first AMF entity obtains attribute information of the first S-NSSAI.

Wherein the first S-NSSAI is an S-NSSAI not supported by the first AMF entity in the requested NSSAI (e.g., S-NSSAI2 described above). The first AMF entity does not support the first S-NSSAI, which means that the first AMF entity is not connected with the slice corresponding to the first S-NSSAI. The attribute information of the first S-NSSAI is used to indicate whether to allow the slice corresponding to the other S-NSSAI to be used to provide the service corresponding to the first S-NSSAI for the terminal device 202 if the current PLMN does not support the first S-NSSAI. For example, the "other S-NSSAI" herein may be a default S-NSSAI (default S-NSSAI).

Alternatively, the first S-NSSAI may be preferentially replaced by other S-NSSAIs in the requested NSSAI.

For example, the first AMF entity sends a request message to the UDM device 212 or the PCF device 214, where the request message carries the permanent identifier of the terminal device 202, and the request message is used to request the slice subscription policy information of the terminal device 202. The first AMF entity receives a response message containing slice subscription policy information. The slice subscription policy information includes each S-NSSAI in the NSSAI subscribed by the terminal device 202 and attribute information of each S-NSSAI. For example, the NSSAI subscribed by the terminal device 202 includes S-NSSAI2,3, and 4, and the slice subscription policy information obtained by the first AMF entity is shown in table 1:

S-NSSAI 2	S-NSSAI 3
		S-NSSAI 3	X
S-NSSAI 4	X

TABLE 1

The first column indicates each S-NSSAI in the NSSAI subscribed by the terminal device 202, and the second column indicates attribute information of each S-NSSAI. In the example of table 1, in the first row, the attribute information of S-NSSAI2 is S-NSSAI3, indicating that the service corresponding to S-NSSAI2 can be provided by the slice corresponding to S-NSSAI3 instead of the slice corresponding to S-NSSAI 2. In the second row, the attribute information of S-NSSAI3 is null, which indicates that the service corresponding to S-NSSAI3 can be replaced by no slice corresponding to other S-NSSAI, in other words, if the current PLMN cannot support S-NSSAI3, no slice corresponding to other S-NSSAI can be provided instead of providing the service corresponding to S-NSSAI 3. Similarly, in the third row, the attribute information of S-NSSAI3 is also null.

After receiving the response message including the slice subscription policy information, the first AMF entity may acquire the attribute information of the first S-NSSAI from the slice subscription policy information.

Step 303, the first AMF entity provides the service corresponding to the first S-NSSAI for the terminal device 202 by using the slice corresponding to the second S-NSSAI according to the attribute information.

For example, the first AMF entity knows that the second S-NSSAI can provide a service corresponding to the first S-NSSAI instead of the first S-NSSAI according to the attribute information. For example, the service corresponding to S-NSSAI2 may be provided by a slice corresponding to S-NSSAI 3. In other words, the second S-NSSAI is determined according to the attribute information and can provide a service corresponding to the first S-NSSAI in place of the first S-NSSAI. For example, the second S-NSSAI is S-NSSAI 3. Optionally, the second S-NSSAI is an S-NSSAI of the requested NSSAI.

Since the first AMF entity supports S-NSSAI3, 4 and the service corresponding to S-NSSAI2 can be provided by the slice corresponding to S-NSSAI3, the first AMF entity that supports S-NSSAI3, 4 can provide the service corresponding to S-NSSAI2,3,4 to the terminal device 202. The first AMF entity may use the slice corresponding to the second S-NSSAI to provide the terminal device 202 with the service corresponding to the first S-NSSAI to serve the terminal device 202.

In step 304, the first AMF entity adds indication information (indication) in the context of the terminal device 202, where the indication information is used to indicate that the first AMF entity uses the slice corresponding to the second S-NSSAI to provide the service corresponding to the first S-NSSAI for the terminal device 202. For example, the indication information is used to indicate that the first AMF entity provides the service corresponding to S-NSSAI2 for the terminal device 202 by using the slice corresponding to S-NSSAI 3.

Optionally, the first AMF entity may further add the received slice subscription policy information to the context of the terminal device 202.

At step 305, the first AMF entity sends a request message to PCF device 214. The request message carries the indication information. For example, the request message is a Network Slice Selection Policy (NSSP) update request message.

Step 306, PCF device 214 updates the NSSP according to the indication information after receiving the request message, and sends a response message carrying the updated NSSP to the first AMF entity. For example, before PCF device 214 receives the request message, the NSSP of terminal device 202 stored in PCF device 214 is shown in table 2:

NSSP rule 1	Applications A	S-NSSAI 2
			NSSP rule 2	Application B	S-NSSAI 2
NSSP rule 3	Applications C	S-NSSAI 3
			NSSP rule 4	Applications D	S-NSSAI 4

TABLE 2

An NSSP comprises one or more NSSP rules, each of which associates an application (application) with an S-NSSAI. For example, in the NSSP of the terminal device 202, NSSP rule 1 is associated with application a and S-NSSAI2, and NSSP rule 2 is associated with application B and S-NSSAI 2. In other words, application a and application B need to select slices according to NSSP rule 1 and rule 2, respectively, and the slice types corresponding to application a and application B both correspond to S-NSSAI 2. By analogy, NSSP rule 3 is associated with applications C and S-NSSAI3, and NSSP rule 4 is associated with applications D and S-NSSAI 4.

PCF device 214 updates the NSSP of terminal device 202 after receiving the request message carrying the indication information. For example, PCF device 214 updates NSSP rules relating to a first S-NSSAI to be both associated with a second S-NSSAI (e.g., S-NSSAI 3). The updated NSSP is referred to as a first NSSP and includes an association of an application with a second S-NSSAI. For example, the first NSSP is shown in table 3:

NSSP rule 1	Applications A	S-NSSAI 3(flag)
			NSSP rule 2	Application B	S-NSSAI 3(flag)
NSSP rule 3	Applications C	S-NSSAI 3
			NSSP rule 4	Applications D	S-NSSAI 4

TABLE 3

For example, when the PCF apparatus 214 generates the first NSSP, a flag bit (flag) is added to the modified NSSP rule, where the flag bit is used to indicate that the first S-NSSAI corresponding to the NSSP rule is modified by the core network to become the second S-NSSAI, so as to distinguish the NSSP rule modified to be associated with the second S-NSSAI from the non-modified NSSP rule itself associated with the second S-NSSAI.

For example, in table 3, a flag bit (flag) is added to the second S-NSSAI (i.e., S-NSSAI3) corresponding to NSSP rule 1 and NSSP rule 2, respectively, to distinguish the differences between NSSP rules 1 and 2 and NSSP rule 3: NSSP rule 1 and NSSP rule 2 are rules that will be applied in association with the second S-NSSAI after modification by the core network. Whereas NSSP rule 3 is unmodified by the core network and is itself the rule that will apply in association with the second S-NSSAI.

PCF device 214 then sends a response message to the first AMF entity. The response message carries the first NSSP.

In step 307, the first AMF entity sends a registration accept message to the terminal device 202 through the access network device 204. The registration accept message includes the first NSSP and the allowed NSSAI. Wherein the allowed NSSAI comprises the second S-NSSAI. For example, S-NSSAI3 is a second S-NSSAI, and permissible NSSAIs include S-NSSAI3, 4.

In addition, the registration acceptance message further includes a temporary identifier allocated by the first AMF entity to the terminal device 202. For example, the temporary identifier includes a 5G-globally unique temporary identifier (5G-globally unique temporary identifier, 5G-GUTI). The temporary identifier assigned to the terminal device 202 by the first AMF entity includes a first field (e.g., identification information of the first AMF) for identifying the first AMF entity, and a second field for uniquely identifying the terminal device 202 in the first AMF entity.

At step 308, the terminal device 202 stores the first NSSP. In addition, the terminal device 202 also stores the allowed NSSAI.

Subsequently, the terminal device 202 selects a corresponding S-NSSAI for the application to initiate a session establishment procedure according to the first NSSP associated application and S-NSSAI. For example, an application of the terminal device 202 initiates data transfer, and the terminal device 202 selects an S-NSSAI for the application based on the first NSSP. For example, to apply data transmission initiated by a, the terminal device 202 selects S-NSSAI3 according to NSSP rule 1 in the first NSSP, sends a session establishment request message carrying the S-NSSAI3 to the core network, and the core network continues the session establishment procedure.

According to the slice selection method in the embodiment of the present application, the first AMF entity obtains the attribute information from the UDM device 212 or the PCF device 214, and according to the attribute information, when the first AMF entity does not support the first S-NSSAI, the slice corresponding to the second S-NSSAI is used to provide the service corresponding to the first S-NSSAI for the terminal device 202. Thus, services corresponding to the first S-NSSAI that are not supported are not discarded, but instead provided by slices corresponding to the second S-NSSAI. In addition, the PCF device 214 accordingly updates the NSSP rules relating to the first S-NSSAI to be associated with the second S-NSSAI. Therefore, after the terminal device 202 receives the NSSP rule, the terminal may sense that the service corresponding to the first S-NSSAI is provided instead of the slice corresponding to the second S-NSSAI. Therefore, the service corresponding to the NSSAI requested by the terminal device 202 can be satisfied, and the service experience of the user is improved.

When the terminal device 202 moves from the first PLMN to the second PLMN, the AMF entity needs to be reselected. As shown in fig. 4, the first AMF entity is located in the first PLMN, and the second PLMN includes the second AMF entity and the third AMF entity. For example, the second AMF entity supports S-NSSAI3, 4, and the third AMF entity supports S-NSSAI2,3, 4. Since the allowed NSSAI stored in the terminal device 202 includes S-NSSAI3, 4, when the terminal device 202 initiates the periodic registration update request procedure again after moving, the NSSAI requested by the terminal device 202 is the allowed NSSAI. Thus, both the second AMF entity and the third AMF entity can fulfill the request of the terminal device 202. According to the scheme of the application, the terminal device 202 may be redirected to the "most suitable" third AMF entity by the "second AMF entity that is" next suitable "to obtain the service, so as to improve the service experience of the user.

This is further described below in conjunction with the signaling interaction diagram of fig. 5.

Before step 501, the terminal device 202 is located in the first PLMN, and the terminal device 202 is registered with the first AMF entity through a registration procedure. For example, the terminal device 202 registers with the first AMF entity through steps 301 to 308 in fig. 3 described above. And will not be described in detail herein.

In step 501, when the terminal device 202 moves from the first PLMN to the second PLMN, the terminal device 202 sends a registration request message to the access network device 204' in the second PLMN.

Wherein, the registration request message carries the requested NSSAI. At this point, the requested NSSAI is the allowed NSSAI stored by the terminal device 202. In fig. 5, the allowed NSSAI carried by the UE in step 501 is referred to as a first allowed NSSAI, and the first allowed NSSAI includes the second S-NSSAI. For example, the first allowed NSSAI includes S-NSSAI3, 4.

In addition, the registration request message further includes the temporary identifier allocated by the first AMF entity to the terminal device 202. At this time, the temporary identifier may also be referred to as an old temporary identifier.

Step 502, after the access network device 204' receives the registration request message, it selects an AMF entity for the terminal device 202 according to the requested NSSAI.

For example, due to the movement of the terminal device 202, the access network device 204' in the second PLMN cannot identify the first AMF entity according to the old temporary identity of the terminal device 202. Accordingly, the access network device 204're-selects the AMF entity for the terminal device 202 based on the requested NSSAI.

For example, the requested NSSAI includes S-NSSAI3, 4. A second AMF entity within the second PLMN supports S-NSSAI3, 4 in the requested NSSAI, and a third AMF entity within the second PLMN additionally supports S-NSSAI 2. And the access network equipment selects a second AMF entity according to the local policy information.

At step 503, the access network device 204' sends a registration request message to the second AMF entity. The registration request message includes the requested NSSAI and the old temporary identity of the terminal device 202.

In step 504, after receiving the registration request message, the second AMF entity obtains the context of the terminal device 202 from the first AMF entity according to the old temporary identifier of the terminal device 202.

For example, the second AMF entity obtains the identification information of the first AMF entity according to the first field in the old temporary identifier of the terminal device 202, so as to request the first AMF entity to obtain the context of the terminal device 202. Since the first AMF entity adds the indication information for instructing the first AMF entity to provide the service corresponding to the first S-NSSAI for the terminal device 202 by using the slice corresponding to the second S-NSSAI in the context of the terminal device 202 before (for example, by step 304 in fig. 3), the context of the terminal device 202 acquired by the second AMF entity from the first AMF entity includes the above indication information.

Meanwhile, the second AMF entity obtains the slice subscription policy information of the terminal device 202 from the first AMF entity in the context of the terminal device 202.

In step 505, if the second AMF entity does not support the first S-NSSAI, the second AMF entity redirects the terminal device 202 to a third AMF entity supporting the first S-NSSAI in the second PLMN.

For example, the second AMF entity knows, according to the indication information in the context: previously, the service corresponding to the first S-NSSAI was provided by the slice corresponding to the second S-NSSAI for the terminal device 202. In conjunction with the NSSAI (including the second S-NSSAI) of the request received by the second AMF entity at step 503, the second AMF entity may learn: the NSSAI "actually" requested by the terminal device 202 includes at least a first S-NSSAI. Thus, the second AMF entity is not the "most suitable" AMF entity to serve the terminal device 202. If there are other AMF entities (e.g., a third AMF entity) supporting the first S-NSSAI within the second PLMN, the second AMF entity redirects the terminal device 202 to the third AMF entity supporting the first S-NSSAI within the second PLMN. Moreover, the second AMF entity learns that the terminal device 202 has subscribed to the first S-NSSAI according to the slice subscription policy information included in the context acquired in step 504, and then, an AMF entity (for example, a third AMF entity) existing in the current PLMN may provide the UE with a slice service corresponding to the first S-NSSAI.

Or, after obtaining the indication information, the second AMF entity learns: the "actual" requested NSSAI of the terminal device 202 includes at least a first S-NSSAI and a second S-NSSAI. Thus, the second AMF entity is not the "most suitable" AMF entity to serve the terminal device 202, and the terminal device 202 is redirected to a third AMF entity supporting the first S-NSSAI and the second S-NSSAI within the second PLMN. Moreover, the second AMF entity knows that the terminal device 202 has signed the first S-NSSAI and the second S-NSSAI according to the slice subscription policy information included in the context acquired in step 504, and then, an AMF entity (for example, a third AMF entity) existing in the current PLMN may provide the UE with a slice service corresponding to both the first S-NSSAI and the second S-NSSAI.

For example, the second AMF entity may select the third AMF entity through the following three implementation manners, however, the method of selecting the third AMF entity by the second AMF entity is not limited in the present invention.

In a first possible implementation manner, the second AMF entity is configured with identification information of other AMF entities in the current second PLMN and corresponding capability information (supported S-NSSAI), and the second AMF entity determines that the third AMF entity can support the first S-NSSAI according to the capability information of other AMFs, and obtains the identification information of the third AMF entity.

In a second possible implementation manner, the second AMF entity sends a request message to a Network Slice Selection Function (NSSF) network element, where the request message carries an S-NSSAI (e.g., the first S-NSSAI) that the target AMF entity needs to support. After receiving the request message, the NSSF determines that the third AMF entity can support the first S-NSSAI, and sends a response message to the second AMF entity, wherein the response message carries the identification information of the third AMF entity.

In a third possible implementation manner, the second AMF entity sends a request message to a network Function discovery Function (NRF) network element, where the request message carries an S-NSSAI (e.g., the first S-NSSAI) that the target AMF entity needs to support. After receiving the request message, the NRF determines that the third AMF entity can support the first S-NSSAI, and sends a response message to the second AMF entity, wherein the response message carries the identification information of the third AMF entity.

By way of example in connection with the above example, the NSSAI of the request received by the second AMF entity via step 503 comprises S-NSSAI3, 4. The second AMF entity obtains the indication information through step 504: the first AMF entity provides the service corresponding to S-NSSAI2 to the terminal device 202 using the slice corresponding to S-NSSAI 3. Thus, the second AMF entity knows that the NSSAI requested "actually" by the terminal device 202 comprises S-NSSAI2,3, 4. Since the second AMF entity only supports S-NSSAI3, 4 but not S-NSSAI2, the second AMF entity is not the "most suitable" AMF entity to serve the terminal device 202. Since there is a third AMF entity in the second PLMN that supports S-NSSAI2,3,4 at the same time, the second AMF entity redirects the terminal device 202 to the third AMF entity that supports S-NSSAI2,3, 4.

For example, redirection may be achieved by two implementations:

in a possible implementation manner, the second AMF entity may forward the registration request message sent by the terminal device 202 to the third AMF entity through the access network device 204 ', that is, the second AMF entity first sends the registration request message sent by the terminal device 202 and the identification information of the third AMF entity to the access network device 204 ', and the access network device 204 ' forwards the registration request message sent by the terminal device 202 to the third AMF entity according to the identification information of the third AMF entity.

In another possible implementation manner, the second AMF entity directly forwards the registration request message sent by the terminal device 202 to the third AMF entity according to the identification information of the third AMF entity.

In the above two implementation manners, the registration request message sent by the terminal device 202 forwarded by the second AMF entity is the same as the parameters carried in step 501. See step 501 for a detailed description.

After redirection is completed, the third AMF entity serves the terminal device 202.

The third AMF entity sends a request message to PCF device 214, step 506. The request message carries the indication information for requesting PCF device 214 to update the NSSP related to the second S-NSSAI. For example, the request message is a network slice selection policy update request message.

For example, the third AMF entity first obtains the indication information as follows:

a first possible implementation: in the above redirection process, the second AMF entity passes the context containing the indication information to the third AMF entity.

A second possible implementation: in the above redirection procedure, the third AMF entity obtains the old temporary identity of the terminal device 202. Thereafter, the third AMF entity obtains the context of the terminal device 202 containing the indication information from the first AMF entity according to the old temporary identity of the terminal device 202.

In step 507, PCF device 214 updates the NSSP according to the indication information after receiving the request message, and sends a response message carrying the updated NSSP to the first AMF entity.

For example, before PCF device 214 receives the request message, the NSSP of terminal device 202 stored in PCF device 214 is as described in table 3 above. PCF device 214, upon receiving the request message carrying the indication information, updates the NSSP rules associated with the second S-NSSAI to be associated with the first S-NSSAI (e.g., S-NSSAI 2).

For example, when PCF device 214 generates the first NSSP of terminal device 202, a flag is added to the modified NSSP rule to indicate that the first S-NSSAI corresponding to the NSSP rule is modified by the core network to become the second S-NSSAI, so as to distinguish the NSSP rule modified to be associated with the second S-NSSAI from the NSSP rule that is not modified and is itself associated with the second S-NSSAI. Then, PCF apparatus 214 receives the request message carrying the indication information in step 507, and knows to update the second S-NSSAI included in the NSSP rule modified before to the first S-NSSAI. For example, PCF device 214 may determine that NSSP rule 1 and NSSP rule 2 are previously modified NSSP rules based on the flags in table 3, and update the second S-NSSAI (i.e., S-NSSAI3) contained in NSSP rule 1 and NSSP rule 2 to the first S-NSSAI (i.e., S-NSSAI 2). Although NSSP rule 3 also contains a second S-NSSAI (i.e., S-NSSAI3), since NSSP rule 3 does not contain a flag, no modification to the second S-NSSAI is required.

The updated NSSP is a second NSSP that includes an association of the application with the first S-NSSAI. For example, the second NSSP is as shown in table 2 above.

PCF device 214 then sends a response message to the third AMF entity. The response message carries a second NSSP.

The third AMF entity sends a registration accept message to the terminal device 202 via the access network device 204, step 508. The registration accept message includes the second NSSP and the second allowed NSSAI.

For example, the third AMF entity determines the second allowed NSSAI according to the requested NSSAI (i.e., the first allowed NSSAI) carried by the terminal device 202 in the registration request message, the subscription information of the terminal device 202, and the slice type supported by the third AMF entity. The second allowed NSSAI comprises the first S-NSSAI described above. Optionally, the second allowed NSSAI further comprises a second S-NSSAI. For example, S-NSSAI2 is a first S-NSSAI and S-NSSAI3 is a second S-NSSAI. The second allowed NSSAI includes S-NSSAI2,3, 4.

In addition, the registration acceptance message further includes a temporary identifier allocated by the third AMF entity to the terminal device 202. For example, the temporary identity includes a 5G-GUTI. The 5G-GUTI at the moment is a new temporary identifier. Wherein the new temporary identification of the terminal device 202 includes a first field (e.g., identification information of the third AMF) for identifying the third AMF entity, and a second field for uniquely identifying the terminal device 202 within the third AMF entity.

In step 509, the terminal device 202 stores the second NSSP. In addition, the terminal device 202 also updates the second allowed NSSAI.

Subsequently, the terminal device 202 selects a corresponding S-NSSAI for the application to initiate a session establishment procedure according to the second NSSP associated application and S-NSSAI. For example, to apply data transmission initiated by a, the terminal device 202 selects S-NSSAI2 according to NSSP rule 1 in the second NSSP, sends a session establishment request message carrying the S-NSSAI2 to the core network, and the core network continues the session establishment procedure.

According to the slice selection method in the embodiment of the application, after the terminal device 202 moves, the second AMF entity selected by the access network device 204 requests the context of the terminal device 202 from the first AMF entity before moving, so that it is known that the second AMF entity is not the most suitable AMF entity, and the terminal device 202 is redirected to the third AMF entity supporting the first S-NSSAI and the second S-NSSAI, and the "most suitable" third AMF entity provides a service for the terminal device 202. Thus, although the first AMF entity in the first PLMN does not support the first S-NSSAI, the service corresponding to the first S-NSSAI can still be implemented in the second PLMN after the terminal device 202 moves. The third AMF entity obtains the context containing the indication information, sends the indication information to the PCF equipment and requests the PCF equipment to update the NSSP related to the second S-NSSAI. Thus, the updated NSSP is restored to the "real" content. Subsequently, the terminal device 202 may associate the application with the S-NSSAI according to the updated NSSP, thereby obtaining a complete service. Therefore, the service corresponding to the NSSAI requested by the terminal device 202 can be satisfied, and the service experience of the user is improved.

Fig. 6 illustrates a slice selection method according to an embodiment of the invention. The method may be performed by a first access and mobility management function entity (e.g., the first AMF entity described above). Fig. 6 will be described in conjunction with fig. 3 to 5. For example, the method comprises:

in step 602, the first access and mobility management function entity receives a registration request message from a terminal device (for example, the terminal device 202 described above), where the registration request message includes an NSSAI corresponding to a slice requested to be accessed by the terminal device. The NSSAI corresponding to the slice requesting access at least includes a first S-NSSAI (e.g., the above-mentioned S-NSSAI2), where the first S-NSSAI is an S-NSSAI that is not supported by the first access and mobility management function entity.

For example, step 602 may be as described with reference to step 301 in FIG. 3.

Step 604, the first access and mobility management functional entity obtains attribute information of the first S-NSSAI, and provides the terminal device with a service corresponding to the first S-NSSAI by using a slice corresponding to the second S-NSSAI (for example, the above-mentioned S-NSSAI3) according to the attribute information.

For example, step 604 may be as described with reference to steps 302 and 303 of FIG. 3.

In step 606, the first access and mobility management functional entity obtains an NSSP (e.g., the first NSSP described above), which includes an association between the application and the second S-NSSAI.

For example, step 606 may be as described with reference to step 306 in FIG. 3.

Step 608, the first access and mobility management functional entity sends a registration acceptance message to the terminal device, where the registration acceptance message includes NSSAI and NSSP corresponding to the slice allowed to be accessed by the terminal device, and the NSSAI corresponding to the slice allowed to be accessed includes the second S-NSSAI.

For example, step 606 may be as described with reference to step 307 in FIG. 3.

According to the slice selection method, the first AMF entity obtains the attribute information, and when the first AMF entity does not support the first S-NSSAI, the slice corresponding to the second S-NSSAI is used for providing the service corresponding to the first S-NSSAI for the terminal equipment according to the attribute information. Thus, services corresponding to the first S-NSSAI that are not supported are not discarded, but instead provided by slices corresponding to the second S-NSSAI. Furthermore, the NSSP rule into the NSSP acquired by the first access and mobility management functional entity is associated with the second S-NSSAI. Therefore, after receiving the NSSP rule, the terminal device may perceive that the service corresponding to the first S-NSSAI is provided instead of the slice corresponding to the second S-NSSAI. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

Optionally, the method further includes: the first access and mobility management functional entity adds indication information in the context of the terminal device, where the indication information is used to instruct the first access and mobility management functional entity to provide the service corresponding to the first S-NSSAI for the terminal device using the slice corresponding to the second S-NSSAI (for example, refer to the description of step 304 in fig. 3). Therefore, through the context transfer, other access and mobility management functional entities can acquire the indication information, so as to judge whether the access and mobility management functional entities are suitable for serving the terminal equipment, thereby improving the service experience of the user.

Optionally, step 604 includes: the first access and mobility management function entity obtains attribute information of the first S-NSSAI from a user data management device (e.g., UDM device 212 described above) or a policy control function device (e.g., PCF device 214 described above) (e.g., as described with reference to steps 302a, 302b in fig. 3).

Optionally, step 606 includes: the first access and mobility management function entity sends the indication to a policy control function device (e.g., PCF device 214, above) requesting the policy control function device to update the NSSP related to the first S-NSSAI. The indication information is used for indicating the first access and mobility management functional entity to use the slice corresponding to the second S-NSSAI to provide the service corresponding to the first S-NSSAI for the terminal equipment; the first access and mobility management function entity receives the NSSP from the policy control function device (e.g. as described with reference to step 305 in figure 3).

Optionally, the method further includes: the first access and mobility management functional entity receiving a request message from a second access and mobility management functional entity (e.g., the second AMF entity) to request a context of the terminal device; the first access and mobility management functional entity sends the context of the terminal device to the second access and mobility management functional entity, and the context includes the above-mentioned indication information (for example, refer to the description of step 504 in fig. 5). Therefore, according to the scheme of the application, after the terminal device moves, the second AMF entity requests the context of the terminal device from the first AMF entity before the terminal device moves, so that the fact that the second AMF entity is not the most suitable AMF entity is known, the terminal device is redirected to the third AMF entity supporting the first S-NSSAI, and the "most suitable" third AMF entity provides services for the terminal device. Therefore, although the first AMF entity in the first PLMN does not support the first S-NSSAI, the service corresponding to the first S-NSSAI can still be implemented in the second PLMN after the terminal device moves. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

Fig. 7 illustrates a slice selection method according to an embodiment of the invention. The method may be performed by a second access and mobility management function entity, such as the second AMF entity described above. Fig. 7 will be described in conjunction with fig. 5. For example, the method comprises:

in step 702, the second access and mobility management function entity receives a registration request message, where the registration request message includes an NSSAI corresponding to the slice allowed to be accessed by the terminal device and a temporary identifier of the terminal device (e.g., the old temporary identifier), and the NSSAI corresponding to the slice allowed to be accessed includes a second S-NSSAI (e.g., the S-NSSAI 3).

For example, step 702 may be as described with reference to step 503 in FIG. 5.

In step 704, the second access and mobility management function entity obtains the context of the terminal device from the first access and mobility management function entity (e.g., the first AMF entity) according to the temporary identifier, where the context includes the indication information. The indication information is used to instruct the first access and mobility management functional entity to provide the service corresponding to the first S-NSSAI (e.g., the above-mentioned S-NSSAI2) for the terminal device by using the slice corresponding to the second S-NSSAI.

For example, step 704 may be as described with reference to step 504 in FIG. 5.

In step 706, if the second access and mobility management functional entity does not support the first S-NSSAI, the second access and mobility management functional entity redirects the terminal device to a third access and mobility management functional entity (e.g., the third AMF entity) supporting the first S-NSSAI.

For example, step 706 may be as described with reference to step 505 in FIG. 5.

According to the scheme of the application, after the terminal device moves, the second AMF entity requests the first AMF entity before the terminal device moves for the context of the terminal device, so that the fact that the second AMF entity is not the most suitable AMF entity is known, if other access and mobility management functional entities (such as a third AMF entity) capable of supporting the first S-NSSAI exist in a PLMN network currently visited by the terminal device, the terminal device is redirected to the third AMF entity supporting the first S-NSSAI, and the most suitable third AMF entity provides services for the terminal device. Therefore, although the first AMF entity in the first PLMN does not support the first S-NSSAI, the service corresponding to the first S-NSSAI can still be implemented in the second PLMN after the terminal device moves. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

Optionally, the method further includes: the second access and mobility management functional entity sends the context of the terminal device to the third access and mobility management functional entity, the context including the indication information (for example, refer to the description of step 506 in fig. 5). Thus, the third access and mobility management function entity receiving the indication can send the indication to the PCF device and request the PCF device to update the NSSP relating to the second S-NSSAI. Thus, the updated NSSP is restored to the "real" content. Subsequently, the terminal device may associate the application with the S-NSSAI according to the updated NSSP, thereby obtaining a complete service. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

Fig. 8 illustrates a slice selection method according to an embodiment of the invention. The method may be performed by a third access and mobility management function entity, e.g. the third AMF entity described above. Fig. 8 will be described in conjunction with fig. 5. For example, the method comprises:

step 802, the third access and mobility management functional entity obtains the context of the terminal device, where the context includes the indication information. The indication information is used to instruct a first access and mobility management function entity (e.g., the first AMF entity) to provide a service corresponding to a first S-NSSAI (e.g., the S-NSSAI2) for the terminal device using a slice corresponding to a second S-NSSAI (e.g., the S-NSSAI 3).

For example, step 802 may be as described with reference to step 506 in FIG. 5.

In step 804, the third access and mobility management function entity sends an indication message to the policy control function device (e.g., PCF device 214, described above) requesting the policy control function device to update the NSSP related to the second S-NSSAI. The updated NSSP (e.g., the second NSSP described above) includes an association between the application and the first S-NSSAI.

For example, step 804 may be as described with reference to steps 506 and 507 in FIG. 5.

The third access and mobility management function entity receives the updated NSSP from the policy control function device, step 806.

For example, step 806 may refer to the description of step 507 in FIG. 5.

According to the scheme of the application, when the terminal equipment moves, the third AMF entity which is most suitable is used for providing service for the terminal equipment. The third AMF entity obtains the context containing the indication information, sends the indication information to the PCF equipment and requests the PCF equipment to update the NSSP related to the second S-NSSAI. Thus, the updated NSSP is restored to the "real" content. Subsequently, the terminal device may associate the application with the S-NSSAI according to the updated NSSP, thereby obtaining a complete service. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

Fig. 9 illustrates a slice selection method according to an embodiment of the invention. The method may be performed by a policy control function device (e.g., PCF device 214, described above). Fig. 9 will be described in conjunction with fig. 3 to 5. For example, the method comprises:

in step 902, the policy control function device receives indication information from a first access and mobility management function entity (e.g., the first AMF entity described above). The indication information is used to instruct the first access and mobility management function entity to provide the service corresponding to the first S-NSSAI (e.g., the above-mentioned S-NSSAI2) for the terminal device by using the slice corresponding to the second S-NSSAI (e.g., the above-mentioned S-NSSAI 3).

For example, step 902 may be as described with reference to step 305 of FIG. 3.

Step 904, the policy control function device updates the NSSP related to the first S-NSSAI according to the indication information, and sends the updated first NSSP to the first access and mobility management function entity. Wherein the updated first NSSP (e.g., the first NSSP described above) comprises an association between the application and the second S-NSSAI.

For example, step 904 may be as described with reference to step 306 in FIG. 3.

According to the scheme of the application, when the first AMF entity does not support the first S-NSSAI and the slice corresponding to the second S-NSSAI is used for providing the service corresponding to the first S-NSSAI for the terminal equipment, the PCF equipment updates the NSSP related to the first S-NSSAI, so that the updated NSSP comprises the association between the application and the second S-NSSAI. Thus, services corresponding to the first S-NSSAI that are not supported are not discarded, but instead provided by slices corresponding to the second S-NSSAI. And through the updating of the PCF equipment to the NSSP, the terminal equipment can sense that the service corresponding to the first S-NSSAI is provided by the slice corresponding to the second S-NSSAI instead. The service corresponding to NSSAI requested by the terminal equipment can be satisfied, and the service experience of the user is improved.

Optionally, the method further includes: the policy control function device receives the indication information from a third access and mobility management function entity (e.g., the third AMF entity described above); the policy control function device updating the NSSP related to the second S-NSSAI according to the indication information, the updated second NSSP (e.g., the second NSSP described above) including an association between the application and the first S-NSSAI; and the policy control function device sends the updated second NSSP to a third access and mobility management function entity.

Therefore, when the terminal device moves, the terminal device is served by the "most suitable" third AMF entity. The third AMF entity sends the indication information to the PCF device and requests the PCF device to update the NSSP related to the second S-NSSAI. Thus, the updated NSSP is restored to the "real" content. Subsequently, the terminal device may associate the application with the S-NSSAI according to the updated NSSP, thereby obtaining a complete service. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

In addition, another slice selection method is provided. The method may be performed by a terminal device (e.g., terminal device 202 described above). As shown in fig. 10, the method includes:

step 1001, the terminal device determines, according to the NSSP, whether the current location of the terminal device is within a service area of the first slice corresponding to the first S-NSSAI. Wherein the NSSP includes an association between the first S-NSSAI and a service area of the first slice.

In this embodiment, the NSSP stored in the terminal device has one additional dimension compared with the NSSP in the prior art: service area (serving area) of slice corresponding to S-NSSAI. In other words, in the present embodiment, the NSSP includes one or more NSSP rules, and each NSSP rule associates the application, the S-NSSAI, and the service area of the slice corresponding to the S-NSSAI. The service area may be a certain location area, and for example, the certain location area may be identified by a tracking area list (TA list). Furthermore, the service area may also be an area of full network coverage (e.g., all PLMNs). The full network coverage indicates that no matter where the terminal device is located, the terminal device is located within the service area of the slice corresponding to the S-NSSAI.

For example, NSSPs stored in the terminal device are shown in table 4:

NSSP rule 1	Applications A	S-NSSAI-2	Service area 2
				NSSP rule 2	Application B	S-NSSAI-2	Service area 2
NSSP rule 3	Applications C	S-NSSAI-3	Service areas 2,3
				NSSP rule 4	Applications D	S-NSSAI-4	Service areas 2,3

TABLE 4

The first S-NSSAI is the S-NSSAI included in the NSSAI that the terminal device wants to request. Before sending the registration request message, the terminal device first determines whether the current location of the terminal device is within the service area of the first slice corresponding to the first S-NSSAI according to the NSSP.

In connection with the example of table 4, the NSSAI that the terminal device wants to request includes S-NSSAI2,3,4, and the current location of the terminal device is within service area 3. Before sending the registration request message, the terminal device knows that the terminal device is within the service area of S-NSSAI3, 4, but not within the service area of S-NSSAI2, according to the NSSP of table 4. Therefore, the terminal device 202 requests the service corresponding to S-NSSAI3, 4 only from the network, and does not request the service corresponding to S-NSSAI2 from the network.

In addition, the terminal equipment can also judge whether the PLMN in which the terminal equipment is currently located is provided with the slice corresponding to the S-NSSAI according to the NSSP. And if the current PLMN is provided with the slice corresponding to the S-NSSAI, judging whether the current position of the terminal equipment is located in the service area of the slice. For example, the NSSAI that the terminal device wants to request also includes S-NSSAI 5. As can be seen from table 4, since no slice corresponding to S-NSSAI 5 is deployed in the PLMN, the terminal device does not request the network for the service corresponding to S-NSSAI 5.

From another perspective, if the current location of the terminal device is located in the service area of the first slice, it indicates that the PLMN where the terminal device is currently located is configured with the first slice corresponding to the first S-NSSAI.

Step 1002, when the current position of the terminal device is in the service area of the first slice, the terminal device sends a registration request message. The registration request message carries the first S-NSSAI. The first S-NSSAI is used to select the first slice.

In connection with the above example, the terminal device is within the service area of S-NSSAI3, 4, but not within the service area of S-NSSAI 2. Thus, the NSSAI in the registration request message includes S-NSSAI3, 4, and does not include S-NSSAI 2. That is, the first S-NSSAI is S-NSSAI3 or 4.

For example, after receiving the registration request message, the access network device in service area 3 selects AMF entity i supporting S-NSSAI3, 4 in the area. Thereafter, other steps in the registration process are continuously executed until the registration process is ended, and the invention is not described here.

Therefore, according to the slice selection method in the embodiment of the present application, before the terminal device initiates a registration request, it is first determined whether the current location of the terminal device is within the service area of the slice corresponding to the first S-NSSAI in the requested NSSAI. The first S-NSSAI is included in the NSSAI of the registration request message only if the current location of the terminal device is within the service area. Therefore, the phenomenon that the core network rejects the registration request of the terminal equipment because the core network cannot support the S-NSSAI requested by the terminal equipment is avoided, and the signaling interaction between the terminal equipment and the core network is saved.

Alternatively, after the terminal device moves from the service area 3 to the service area 2, the terminal device may initiate a periodic registration request. Before sending the registration request message, the terminal device still determines whether the current location of the terminal device is within the service area of the slice corresponding to each S-NSSAI requested, in step 1003.

For example, the terminal device wants the S-NSSAI2,3,4 included in the requested NSSAI, and the current location of the terminal device has moved into service area 2. Before sending the registration request message, the terminal device learns that the terminal device is in the service area of S-NSSAI2,3,4 according to the NSSP of table 4. Therefore, in step 1004, the terminal device 202 sends a registration request message to the network requesting a service corresponding to S-NSSAI2,3, 4. After receiving the registration request message, the access network device in the service area 3 cannot connect to the AMF entity i that previously served the terminal device, and then selects the AMF entity ii supporting S-NSSAI2,3,4 in the area according to the requested S-NSSAI2,3, 4. Thereafter, other steps in the registration process are continuously executed until the registration process is ended, and the invention is not described here.

That is, the step of determining, by the terminal device, whether the current location of the terminal device is within the service area of the first slice corresponding to the first S-NSSAI according to the NSSP includes: and the terminal equipment periodically judges whether the base station corresponding to the current position of the terminal equipment is in the service area of the first slice. Therefore, if the location of the terminal device at the first time is not in the service area of the slice corresponding to the first S-NSSAI in the requested NSSAI, when the terminal device determines that the location of the terminal device is in the service area of the slice corresponding to the first S-NSSAI in the requested NSSAI at the subsequent second time, a new registration request can still be initiated to obtain the corresponding service.

In the embodiments provided in the present application, various schemes such as the short message transmission method provided in the embodiments of the present application are introduced from the perspective of each network element itself and from the perspective of interaction between network elements. It is to be understood that each network element, for example, the session management function entity and the like, includes a hardware structure and/or a software module for performing each function in order to implement the functions. Those of skill in the art would readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

For example, when the network element implements the corresponding functions through software modules. The access and mobility management functional entity may comprise a receiving module 1101, a processing module 1102 and a sending module 1103 as shown in fig. 11A.

In one embodiment, the access and mobility management function entity may be configured to perform the operations of the first access and mobility management function entity (e.g., the first AMF entity) in fig. 3, 5, and 6 described above. For example:

the receiving module 1101 is configured to receive a registration request message from a terminal device, where the registration request message includes an NSSAI corresponding to a slice requested to be accessed by the terminal device, and the NSSAI corresponding to the slice requested to be accessed at least includes a first single S-NSSAI, where the first S-NSSAI is an S-NSSAI that is not supported by the first access and mobility management functional entity; for obtaining attribute information of the first S-NSSAI. The processing module 1102 is configured to provide, according to the attribute information, a service corresponding to the first S-NSSAI for the terminal device by using a slice corresponding to the second S-NSSAI. The receiving module 1101 is further configured to obtain a network slice selection policy NSSP, which includes an association between an application and the second S-NSSAI. The sending module 1103 is configured to send a registration accept message to the terminal device, where the registration accept message includes the NSSAI and the NSSP corresponding to the slice that the terminal device is allowed to access, and the NSSAI corresponding to the slice that the terminal device is allowed to access includes the second S-NSSAI.

Thus, services corresponding to the first S-NSSAI that are not supported are not discarded, but instead provided by slices corresponding to the second S-NSSAI. The service corresponding to NSSAI requested by the terminal equipment can be satisfied, and the service experience of the user is improved.

Optionally, the processing module 1102 is further configured to add indication information in the context of the terminal device, where the indication information is used to indicate that the first access and mobility management functional entity uses the slice corresponding to the second S-NSSAI to provide the service corresponding to the first S-NSSAI for the terminal device.

Optionally, the receiving module 1101 is configured to obtain attribute information of the first S-NSSAI from a user data management device or a policy control function device.

Optionally, the sending module 1103 is further configured to send indication information to a policy control function device, and request the policy control function device to update the NSSP related to the first S-NSSAI, where the indication information is used to indicate that the first access and mobility management function entity provides, to the terminal device, the service corresponding to the first S-NSSAI by using the slice corresponding to the second S-NSSAI; a receiving module 1101 is configured to receive the NSSP from the policy control function device.

Optionally, the receiving module 1101 is further configured to receive a request message from a second access and mobility management function entity to request a context of the terminal device; the sending module 1103 is further configured to send a context of the terminal device to the second access and mobility management function entity, where the context includes the indication information.

In addition, the receiving module 1101, the processing module 1102 and the sending module 1103 in the first access and mobility management functional entity may also implement other operations or functions of the first AMF entity in the foregoing method, and details are not described here again.

In another embodiment, the access and mobility management function entity may be configured to perform the operations of the second access and mobility management function entity (e.g., the second AMF entity) in fig. 5 and 7. For example:

the receiving module 1101 is configured to receive a registration request message, where the registration request message includes network slice selection assistance information NSSAI corresponding to a slice that the terminal device is allowed to access and a temporary identifier of the terminal device, and the NSSAI corresponding to the slice that is allowed to access includes second single network slice selection assistance information S-NSSAI; and the context acquiring unit is configured to acquire a context of the terminal device from a first access and mobility management functional entity according to the temporary identifier, where the context includes indication information, and the indication information is used to indicate the first access and mobility management functional entity to provide a service corresponding to the first S-NSSAI for the terminal device by using the slice corresponding to the second S-NSSAI. If the second access and mobility management functional entity does not support the first S-NSSAI, the processing module 1102 is configured to redirect the terminal device to a third access and mobility management functional entity that supports the first S-NSSAI.

Therefore, after the terminal device moves, the second AMF entity requests the first AMF entity before moving for the context of the terminal device, so as to learn that the second AMF entity is not the most suitable AMF entity, and if other access and mobility management functional entities (e.g., a third AMF entity) capable of supporting the first S-NSSAI exist in the PLMN network currently visited by the terminal device, the terminal device is redirected to the third AMF entity supporting the first S-NSSAI, and the "most suitable" third AMF entity provides services for the terminal device. Therefore, although the first AMF entity in the first PLMN does not support the first S-NSSAI, the service corresponding to the first S-NSSAI can still be implemented in the second PLMN after the terminal device moves. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

Optionally, the sending module 1103 is configured to send a context of the terminal device to the third access and mobility management functional entity, where the context includes the indication information.

In addition, the receiving module 1101, the processing module 1102 and the sending module 1103 in the second access and mobility management functional entity may also implement other operations or functions of the second AMF entity in the foregoing method, and details are not described here again.

In yet another embodiment, the access and mobility management function entity may be configured to perform the operations of the third access and mobility management function entity (e.g., the third AMF entity) in fig. 5 and 8. For example:

the receiving module 1101 is configured to obtain a context of the terminal device, where the context includes indication information, and the indication information is used to indicate that the first access and mobility management functional entity uses a slice corresponding to the second single-network slice selection auxiliary information S-NSSAI to provide a service corresponding to the first S-NSSAI for the terminal device. The sending module 1103 is configured to send the indication information to a policy control function device, and request the policy control function device to update a network slice selection policy NSSP related to the second S-NSSAI, where the updated NSSP includes an association between an application and the first S-NSSAI. The receiving module 1101 is further configured to receive the updated NSSP from the policy control function device.

Therefore, when the terminal device moves, the terminal device is served by the "most suitable" third AMF entity. The third AMF entity obtains the context containing the indication information, sends the indication information to the PCF equipment and requests the PCF equipment to update the NSSP related to the second S-NSSAI. Thus, the updated NSSP is restored to the "real" content. Subsequently, the terminal device may associate the application with the S-NSSAI according to the updated NSSP, thereby obtaining a complete service. Therefore, the service corresponding to NSSAI requested by the terminal equipment can be met, and the service experience of the user is improved.

In addition, the receiving module 1101, the processing module 1102 and the sending module 1103 in the third access and mobility management functional entity may also implement other operations or functions of the third AMF entity in the foregoing method, and details are not described here again.

Fig. 11B shows another possible structural diagram of the access and mobility management functional entities involved in the above embodiments. The access and mobility management functional entity includes a transceiver 1104 and a processor 1105 as shown in fig. 11B. For example, the processor 1105 is configured to process the access and mobility management function entity to perform the corresponding functions of the first AMF entity, the second AMF entity, or the third AMF entity in the above method. The transceiver 1104 is used for enabling communication between the first, second or third AMF entity and other access and mobility management function entities/policy control function devices/user data management devices/access network devices. The access and mobility management functional entity may also include a memory 1106 for coupling with the processor that stores program instructions and data necessary for the access and mobility management functional entity.

The policy control function device may include a receiving module 1201, a processing module 1202, and a sending module 1203, as shown in fig. 12A. The policy control function device may be configured to perform the operations of the policy control function device (e.g., PCF device 214) of fig. 3, 5, and 9, described above. For example:

the receiving module 1201 is configured to receive indication information from a first access and mobility management functional entity, where the indication information is used to indicate the first access and mobility management functional entity to use a slice corresponding to second single-network slice selection auxiliary information S-NSSAI to provide a service corresponding to the first S-NSSAI for the terminal device. The processing module 1202 is configured to update a network slice selection policy NSSP related to the first S-NSSAI according to the indication information, the updated first NSSP including an association between an application and the second S-NSSAI. A sending module 1203 is configured to send the updated first NSSP to the first access and mobility management functional entity.

Therefore, when the first AMF entity does not support the first S-NSSAI and the slice corresponding to the second S-NSSAI is used for providing the service corresponding to the first S-NSSAI for the terminal equipment, the PCF equipment updates the NSSP related to the first S-NSSAI, so that the updated NSSP comprises the association between the application and the second S-NSSAI. Thus, services corresponding to the first S-NSSAI that are not supported are not discarded, but instead provided by slices corresponding to the second S-NSSAI. And through the updating of the PCF equipment to the NSSP, the terminal equipment can sense that the service corresponding to the first S-NSSAI is provided by the slice corresponding to the second S-NSSAI instead. The service corresponding to NSSAI requested by the terminal equipment can be satisfied, and the service experience of the user is improved.

Optionally, the receiving module 1201 is further configured to receive the indication information from a third access and mobility management function entity; the processing module 1202 is further configured to update the NSSP related to the second S-NSSAI according to the indication information, the updated second NSSP including an association between the application and the first S-NSSAI; the sending module 1203 is further configured to send the updated second NSSP to the third access and mobility management function entity.

In addition, the receiving module 1201, the processing module 1202, and the sending module 1203 in the policy control function device may also implement other operations or functions of the PCF device 214 in the above method, which is not described herein again.

Fig. 12B shows another possible structural diagram of the policy control function device involved in the above embodiment. The policy control function device includes a transceiver 1204 and a processor 1205 as shown in fig. 12B. For example, processor 1205 is configured to process policy control function device to perform the corresponding functions of PCF device 214 in the above-described methods. Transceiver 1204 is used to enable communication between PCF device 214 and the first or third AMF entity. The policy control function device may also include a memory 1206 for coupling with the processor that holds program instructions and data necessary for the policy control function device.

The terminal device may include a processing module 1302 and a sending module 1303, as shown in fig. 13A. The terminal device may be configured to perform the operations of the terminal device (e.g., terminal device 202) described above in fig. 10. For example:

the processing module 1302 is configured to determine, according to a network slice selection policy NSSP, whether a current location of the terminal device is within a service area of a first slice corresponding to first single network slice selection auxiliary information S-NSSAI, where the NSSP includes an association between the first S-NSSAI and the service area of the first slice. When the current location of the terminal device is in the service area of the first slice, the sending module 1303 is configured to send a registration request message, where the registration request message carries the first S-NSSAI, and the first S-NSSAI is used to select the first slice.

Therefore, before the terminal device initiates a registration request, it is determined whether the current location of the terminal device is within the service area of the slice corresponding to the first S-NSSAI in the requested NSSAI. The first S-NSSAI is included in the NSSAI of the registration request message only if the current location of the terminal device is within the service area. Therefore, the phenomenon that the core network rejects the registration request of the terminal equipment because the core network cannot support the S-NSSAI requested by the terminal equipment is avoided, and the signaling interaction between the terminal equipment and the core network is saved.

Optionally, the processing module 1302 is configured to periodically determine whether a base station corresponding to the current location of the terminal device is in the service area of the first slice.

In addition, the terminal device may further include a receiving module 1301. The receiving module 1301, the processing module 1302, and the sending module 1303 in the terminal device may also implement other operations or functions of the terminal device 202 in the foregoing method, which is not described herein again.

Fig. 13B shows another possible structural diagram of the terminal device involved in the above embodiment. The terminal device includes a transceiver 1304 and a processor 1305, as shown in fig. 13B. For example, the processor 1305 is configured to process the terminal device to execute the corresponding functions of the terminal device 202 in the above method. The transceiver 1304 is used to enable communication between the terminal device 202 and the access and mobility management function entity/access network device. The terminal device may also include a memory 1306 coupled to the processor that retains program instructions and data necessary for the terminal device.

It will be appreciated that fig. 11B, 12B, 13B merely show a simplified design of the apparatus described above. In practical applications, each of the above devices may comprise any number of transmitters, receivers, processors, controllers, memories, communication units, etc., and all devices that can implement the present application are within the scope of the present application.

The controller/processor for executing the above-mentioned session management function entity of the present application may be a Central Processing Unit (CPU), a general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. The processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, DSPs, and microprocessors, among others.

The steps of a method or algorithm described in connection with the disclosure herein may be embodied in hardware or in software instructions executed by a processor. The software instructions may consist of corresponding software modules that may be stored in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be integral to the processor. The processor and the storage medium may reside in an ASIC. In addition, the ASIC may be located in a session management function entity. Of course, the processor and the storage medium may reside as discrete components in a session management function.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, 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 loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

The above-mentioned embodiments, objects, technical solutions and advantages of the present application are further described in detail, it should be understood that the above-mentioned embodiments are only examples of the present application, and are not intended to limit the scope of the present application, and any modifications, equivalent substitutions, improvements and the like made on the basis of the technical solutions of the present application should be included in the scope of the present application.

Claims

1. A method of slice selection, comprising:

a first access and mobility management functional entity receives a registration request message from a terminal device, wherein the registration request message includes network slice selection auxiliary information NSSAI corresponding to a slice requested to be accessed by the terminal device, and the NSSAI corresponding to the slice requested to be accessed at least includes first single network slice selection auxiliary information S-NSSAI, wherein the first S-NSSAI is S-NSSAI which is not supported by the first access and mobility management functional entity;

the first access and mobility management functional entity obtains attribute information of the first S-NSSAI, and provides a service corresponding to the first S-NSSAI for the terminal equipment by using a slice corresponding to a second S-NSSAI according to the attribute information;

the first access and mobility management functional entity obtaining a network slice selection policy, NSSP, comprising an association between an application and the second S-NSSAI;

and the first access and mobility management functional entity sends a registration acceptance message to the terminal equipment, wherein the registration acceptance message comprises the NSSAI and the NSSP corresponding to the slice which the terminal equipment is allowed to access, and the NSSAI corresponding to the slice which the terminal equipment is allowed to access comprises the second S-NSSAI.

2. The method of claim 1, further comprising:

and the first access and mobility management functional entity adds indication information in the context of the terminal equipment, wherein the indication information is used for indicating the first access and mobility management functional entity to provide the service corresponding to the first S-NSSAI for the terminal equipment by using the slice corresponding to the second S-NSSAI.

3. The method of claim 1, wherein the obtaining, by the first access and mobility management function entity, the attribute information of the first S-NSSAI comprises:

and the first access and mobility management functional entity acquires the attribute information of the first S-NSSAI from user data management equipment or policy control functional equipment.

4. The method according to claim 2, wherein the first access and mobility management function entity obtaining attribute information of the first S-NSSAI comprises:

5. The method of claim 2, further comprising:

the first access and mobility management functional entity receiving a request message from a second access and mobility management functional entity to request a context of the terminal device;

and the first access and mobility management functional entity sends the context of the terminal equipment to the second access and mobility management functional entity, wherein the context comprises the indication information.

6. The method of claim 4, further comprising:

7. The method according to any of claims 1 to 6, wherein the first access and mobility management function entity acquiring NSSP comprises:

the first access and mobility management functional entity sends indication information to a policy control functional device, and requests the policy control functional device to update the NSSP related to the first S-NSSAI, where the indication information is used to indicate that the first access and mobility management functional entity uses the slice corresponding to the second S-NSSAI to provide the service corresponding to the first S-NSSAI for the terminal device;

the first access and mobility management function entity receives the NSSP from the policy control function device.

8. A method of slice selection, comprising:

a second access and mobility management functional entity receives a registration request message, wherein the registration request message comprises network slice selection auxiliary information NSSAI corresponding to a slice which is allowed to be accessed by terminal equipment and a temporary identifier of the terminal equipment, and the NSSAI corresponding to the slice which is allowed to be accessed comprises second single network slice selection auxiliary information S-NSSAI;

the second access and mobility management functional entity obtains a context of the terminal device from a first access and mobility management functional entity according to the temporary identifier, where the context includes indication information, and the indication information is used to indicate the first access and mobility management functional entity to use a slice corresponding to the second S-NSSAI to provide a service corresponding to the first S-NSSAI for the terminal device;

if the second access and mobility management functional entity does not support the first S-NSSAI, the second access and mobility management functional entity redirects the terminal device to a third access and mobility management functional entity that supports the first S-NSSAI.

9. The method of claim 8, further comprising:

and the second access and mobility management functional entity sends the context of the terminal equipment to the third access and mobility management functional entity, wherein the context comprises the indication information.

10. A method of slice selection, comprising:

a third access and mobility management functional entity acquires a context of a terminal device, wherein the context comprises indication information, and the indication information is used for indicating a first access and mobility management functional entity to use a slice corresponding to second single-network slice selection auxiliary information S-NSSAI to provide a service corresponding to first S-NSSAI for the terminal device;

the third access and mobility management functional entity sending the indication information to a policy control function device, requesting the policy control function device to update a network slice selection policy NSSP relating to the second S-NSSAI, the updated NSSP comprising an association between an application and the first S-NSSAI;

the third access and mobility management function entity receives the updated NSSP from the policy control function device.

11. A method of slice selection, comprising:

the method comprises the steps that a policy control function device receives indication information from a first access and mobility management function entity, wherein the indication information is used for indicating the first access and mobility management function entity to use a slice corresponding to second single-network slice selection auxiliary information S-NSSAI to provide a service corresponding to first S-NSSAI for a terminal device;

the policy control function device updates a network slice selection policy NSSP related to the first S-NSSAI according to the indication information, wherein the updated first NSSP comprises an association between an application and the second S-NSSAI;

and the policy control function device sends the updated first NSSP to the first access and mobility management function entity.

12. The method of claim 11, further comprising:

the policy control function device receiving the indication information from a third access and mobility management function entity;

the policy control function device updating the NSSP related to the second S-NSSAI according to the indication information, the updated second NSSP including an association between the application and the first S-NSSAI;

and the policy control function device sends the updated second NSSP to the third access and mobility management function entity.

13. A method of slice selection, comprising:

the method comprises the steps that a terminal device judges whether the current position of the terminal device is in a service area of a first slice corresponding to first single network slice selection auxiliary information S-NSSAI or not according to a network slice selection strategy NSSP, wherein the NSSP comprises association between the first S-NSSAI and the service area of the first slice;

when the current position of the terminal equipment is in the service area of the first slice, the terminal equipment sends a registration request message, wherein the registration request message carries the first S-NSSAI, and the first S-NSSAI is used for selecting the first slice;

the NSSAI corresponding to the slice requesting access at least comprises first single-network slice selection auxiliary information S-NSSAI, wherein the first S-NSSAI is S-NSSAI which is not supported by a first access and mobility management function entity; the registration request message is used to instruct the first access and mobility management functional entity to acquire attribute information of the first S-NSSAI, and according to the attribute information, a slice corresponding to a second S-NSSAI is used to provide a service corresponding to the first S-NSSAI for the terminal device;

alternatively, the first and second electrodes may be,

the NSSAI corresponding to the slice allowing access includes second single-network slice selection assistance information S-NSSAI, the registration request message is used to instruct the second access and mobility management functional entity to acquire a context of the terminal device from the first access and mobility management functional entity according to the temporary identifier, where the context includes instruction information, and the instruction information is used to instruct the first access and mobility management functional entity to provide a service corresponding to the first S-NSSAI for the terminal device by using the slice corresponding to the second S-NSSAI.

14. The method according to claim 13, wherein the determining, by the terminal device according to a network slice selection policy NSSP, whether the current location of the terminal device is within a service area of a first slice corresponding to first single network slice selection assistance information S-NSSAI comprises:

and the terminal equipment periodically judges whether the base station corresponding to the current position of the terminal equipment is in the service area of the first slice.

15. An access and mobility management function entity, comprising:

a receiving module, configured to receive a registration request message from a terminal device, where the registration request message includes network slice selection auxiliary information NSSAI corresponding to a slice requested to be accessed by the terminal device, and the NSSAI corresponding to the slice requested to be accessed at least includes first single network slice selection auxiliary information S-NSSAI, where the first S-NSSAI is an S-NSSAI that is not supported by a first access and mobility management function entity; the attribute information is used for acquiring the attribute information of the first S-NSSAI;

the processing module is used for providing the service corresponding to the first S-NSSAI for the terminal equipment by using the slice corresponding to the second S-NSSAI according to the attribute information; and

a sending module;

wherein the receiving module is further configured to obtain a network slice selection policy NSSP, the NSSP including an association between an application and the second S-NSSAI; the sending module is configured to send a registration acceptance message to the terminal device, where the registration acceptance message includes the NSSAI and the NSSP corresponding to the slice that the terminal device is allowed to access, and the NSSAI corresponding to the slice that is allowed to access includes the second S-NSSAI.

16. The access and mobility management functional entity according to claim 15, wherein the processing module is further configured to add indication information in the context of the terminal device, where the indication information is used to instruct the first access and mobility management functional entity to provide the service corresponding to the first S-NSSAI for the terminal device by using the slice corresponding to the second S-NSSAI.

17. The access and mobility management function according to claim 15, wherein the receiving module is configured to obtain the attribute information of the first S-NSSAI from a user data management device or a policy control function device.

18. The access and mobility management function according to claim 16, wherein the receiving module is configured to obtain the attribute information of the first S-NSSAI from a user data management device or a policy control function device.

19. The access and mobility management function entity according to claim 16, wherein the receiving module is further configured to receive a request message from a second access and mobility management function entity to request the context of the terminal device;

the sending module is further configured to send a context of the terminal device to the second access and mobility management functional entity, where the context includes the indication information.

20. The access and mobility management function entity according to claim 18, wherein the receiving module is further configured to receive a request message from a second access and mobility management function entity to request the context of the terminal device;

21. The access and mobility management functional entity according to any of claims 15 to 20, wherein the sending module is further configured to send an indication message to a policy control function device, requesting the policy control function device to update the NSSP related to the first S-NSSAI, where the indication message is used to instruct the first access and mobility management functional entity to provide the terminal device with the service corresponding to the first S-NSSAI using the slice corresponding to the second S-NSSAI;

the receiving module is configured to receive the NSSP from the policy control function device.

22. An access and mobility management function entity, comprising:

a receiving module, configured to receive a registration request message, where the registration request message includes network slice selection auxiliary information NSSAI corresponding to a slice that a terminal device is allowed to access and a temporary identifier of the terminal device, and the NSSAI corresponding to the slice that is allowed to access includes second single network slice selection auxiliary information S-NSSAI; the context acquiring unit is configured to acquire a context of the terminal device from a first access and mobility management functional entity according to the temporary identifier, where the context includes indication information, and the indication information is used to indicate the first access and mobility management functional entity to provide a service corresponding to the first S-NSSAI for the terminal device by using the slice corresponding to the second S-NSSAI;

a processing module, configured to, if the first access and mobility management functional entity does not support the first S-NSSAI, redirect the terminal device to a third access and mobility management functional entity that supports the first S-NSSAI.

23. The access and mobility management function entity according to claim 22, further comprising:

a sending module, configured to send a context of the terminal device to the third access and mobility management functional entity, where the context includes the indication information.

24. An access and mobility management function entity, comprising:

a receiving module, configured to obtain a context of a terminal device, where the context includes indication information, and the indication information is used to indicate a first access and mobility management functional entity to use a slice corresponding to second single-network slice selection auxiliary information S-NSSAI to provide, to the terminal device, a service corresponding to first S-NSSAI;

a sending module, configured to send the indication information to a policy control function device, and request the policy control function device to update a network slice selection policy NSSP related to the second S-NSSAI, where the updated NSSP includes an association between an application and the first S-NSSAI;

the receiving module is further configured to receive the updated NSSP from the policy control function device.

25. A policy control function device, comprising:

a receiving module, configured to receive indication information from a first access and mobility management functional entity, where the indication information is used to indicate the first access and mobility management functional entity to use a slice corresponding to second single-network slice selection auxiliary information S-NSSAI to provide, to a terminal device, a service corresponding to the first S-NSSAI;

a processing module, configured to update a network slice selection policy NSSP related to the first S-NSSAI according to the indication information, where the updated first NSSP includes an association between an application and the second S-NSSAI;

a sending module, configured to send the updated first NSSP to the first access and mobility management functional entity.

26. The policy control function device according to claim 25,

the receiving module is further configured to receive the indication information from a third access and mobility management function entity;

the processing module is further configured to update the NSSP related to the second S-NSSAI according to the indication information, the updated second NSSP including an association between the application and the first S-NSSAI;

the sending module is further configured to send the updated second NSSP to the third access and mobility management functional entity.

27. A terminal device, comprising:

a processing module, configured to determine, according to a network slice selection policy NSSP, whether a current location of the terminal device is within a service area of a first slice corresponding to first single network slice selection auxiliary information S-NSSAI, where the NSSP includes an association between the first S-NSSAI and the service area of the first slice;

a sending module, configured to send a registration request message when the current location of the terminal device is within a service area of the first slice, where the registration request message carries the first S-NSSAI, and the first S-NSSAI is used to select the first slice;

alternatively, the first and second electrodes may be,

28. The terminal device of claim 27,

the processing module is configured to periodically determine whether a base station corresponding to the current location of the terminal device is in the service area of the first slice.

29. An access and mobility management function entity, comprising:

a communication interface for receiving and transmitting data;

a memory to store instructions;

at least one processor configured to execute the instructions in the memory to cause the access and mobility management functional entity to perform the method of any of claims 1 to 10.

30. A policy control function device, comprising:

a communication interface for receiving and transmitting data;

a memory to store instructions;

at least one processor configured to execute the instructions in the memory to cause the policy control function device to perform the method of claim 11 or 12.

31. A terminal device, comprising:

a communication interface for receiving and transmitting data;

a memory to store instructions;

at least one processor configured to execute the instructions in the memory to cause the access and mobility management functional entity to perform the method of claim 13 or 14.

32. A computer-readable storage medium comprising instructions that, when executed on a computer, cause the computer to perform the method of any of claims 1-14.

33. A chip apparatus comprising a processor configured to perform the method of any one of claims 1-14.