Patent Description:
In the era of 5th-generation (the 5th-Generation, <NUM>) communications, hundreds of billions of internet of things devices access networks, and network requirements in different types of application scenarios are differentiated. In a network slicing technology, virtualized independent logical networks are created on a same network infrastructure to provide isolated network environments for different application scenarios, so that network functions and features can be customized based on requirements in the different application scenarios, thereby meeting requirements of different services.

Because user equipment has different requirements on a rate, a capacity, a coverage ratio, a delay, reliability, security, and bandwidth, different network slice types are required. Different network slice types may be identified by using network slice identification information. For example, the network slice identification information is single network slice selection assistance information (Single Network Slice Selection Assistance Information, S-NSSAI).

To meet different service requirements, an operator may deploy different network slice instances (Network Slice Instance, NSI) in a network slice to provide different services for user equipment. For example, in a core network, two network slice instances NSI-<NUM> and NSI-<NUM> are deployed in a network slice whose network slice identification information is S-NSSAI-<NUM>. A user accessing NSI-<NUM> may use a service of the network slice identified by S-NSSAI-<NUM> free of charge, but a user accessing NSI-<NUM> needs to pay for using the service of the network slice identified by S-NSSAI-<NUM>. In this way, the operator may implement some function optimization or charging differentiation for different network slice instances.

Currently, when user equipment needs to access a network slice, the user equipment provides, to a core network, identification information of a network slice required by the user equipment. The core network determines, based on the identification information, a network slice meeting a network slice type, and selects a network slice instance deployed in the network slice to provide a service for the user equipment. After moving, the user equipment needs to access a new network slice instance. According to the solution in the prior art, a network slice instance selected by the user equipment based on the network slice identification information meets only the network slice type required by the user equipment, and a network slice instance after the user equipment moves may be different from the network slice instance before the user equipment moves. Consequently, a session of the user before the user moves cannot be maintained, and user experience deteriorates.

For example, <FIG> shows a scenario in which user equipment selects network slice instances before and after moving, where the user equipment is located within coverage of a radio access network (Radio Access Network, RAN) RAN-<NUM> before moving, and in a core network, two network slice instances NSI-<NUM> and NSI-<NUM> are deployed in a network slice whose network slice identification information is S-NSSAI-<NUM>. The user equipment accesses the network slice instance NSI-<NUM>, and establishes a session by using a network element in NSI-<NUM>. When the user equipment moves to a coverage area of a radio access network RAN-<NUM>, in the core network, two network slice instances NSI-<NUM> and NSI-<NUM> are deployed in a network slice whose network slice identification information is S-NSSAI-<NUM>. The core network determines, based on network slice identification information provided by the user equipment, the network slice whose network slice identification information is S-NSSAI-<NUM>, and then selects the network slice instance NSI-<NUM> to provide a service for the user equipment. Because a network element providing a session service in the network slice instance NSI-<NUM> is different from that in NSI-<NUM>, the session before the user equipment moves cannot be maintained. <NPL> relates to assistance information for network slice selection in RRC. <NPL> relates to discussions on Temp ID and NSSAI duplication. <NPL> relates to requirements for management support slice selection.

Embodiments of the present invention provide a network slicing-based communication method, a network slicing-based communications apparatus and a computer-readable storage medium.

To describe the technical solutions in embodiments of the present invention more clearly, the following describes the accompanying drawings required in the embodiments of the present invention or the background.

The following clearly describes technical solutions in embodiments of this application with reference to the accompanying drawings in the embodiments of this application. "A plurality of" in this application means two or more.

<FIG> is a schematic diagram of a <NUM> communications system according to an embodiment of this application. In a <NUM> mobile network architecture, a control plane function and a forwarding plane function of a mobile gateway are decoupled. The separated control plane function is combined with a conventional control network element, that is, a mobility management entity (mobility management entity, MME), or the like in third generation partnership project (third generation partnership project, 3GPP), forming a unified control plane (control plane). A user plane function (User plane function, UPF) network element can implement user plane functions (SGW-U and PGW-U) of a serving gateway (serving gateway, SGW) and a packet data network gateway (packet data network gateway, PGW). Further, the unified control plane network element may be divided into an access and mobility management function (access and mobility management function, AMF) network element and a session management function (session management function, SMF) network element.

As shown in <FIG>, the communications system includes at least user equipment (User Equipment, UE) <NUM>, a RAN device <NUM>, an AMF network element <NUM>, a network slice selection function (Network Slice Selection Function, NSSF) network element <NUM>, and a unified data management (Unified Data Management, UDM) network element <NUM>.

The user equipment <NUM> in this system is not limited to user equipment of a <NUM> network, and may include a mobile phone, an internet of things device, a smart home device, an industrial control device, a vehicle device, and the like. The user equipment may also be referred to as terminal equipment (Terminal Equipment), a mobile station (Mobile Station), a mobile (Mobile), a remote station (Remote Station), a remote terminal (Remote Terminal), an access terminal (Access Terminal), a user equipment (User Terminal), or a user agent (User Agent). This is not limited herein. The user equipment may alternatively be a vehicle in vehicle-to-vehicle (Vehicle-to-vehicle, V2V) communication, a machine in machine-type communication, or the like.

The RAN device <NUM> is an apparatus configured to provide a wireless communication function for the user equipment <NUM>. The RAN device <NUM> may include base stations in one of various forms, for example, a macro base station, a micro base station (also referred to as a small cell), a relay station, and an access point. In systems that use different radio access technologies, names of a device that has a base station function may be different. For example, in an LTE system, the device is referred to as an evolved NodeB (evolved NodeB, eNB or eNodeB); in a <NUM>rd generation (<NUM>rd Generation, <NUM>) system, the device is referred to as a NodeB (Node B). In next-generation system, the device is referred to as a gNB (gNodeB).

The AMF network element <NUM> in the system may be responsible for registration, mobility management, a tracking area update process, and the like of the terminal device. The AMF network element may also be referred to as an AMF device or an AMF entity.

The NSSF network element <NUM> in the system can select a network slice for the user equipment. The NSSF network element may also be referred to as an NSSF device or an NSSF entity.

The UDM network element <NUM> involved in this system can store subscription data of a user. For example, the subscription data of the user includes subscription data related to mobility management and subscription data related to session management. The UDM network element may also be referred to as a UDM device or a UDM entity.

Optionally, network devices in the <NUM> communications system shown in <FIG> further includes an SMF network element <NUM>. The SMF network element <NUM> may be responsible for session management of the terminal device. For example, session management includes user plane device selection, user plane device reselection, internet protocol (internet protocol, IP) address allocation, quality of service (quality of service, QoS) control, and session establishment, modification, or release.

Optionally, the <NUM> communications system further includes a network function repository function (Network Function Repository Function, NRF) network element <NUM>. The network element can provide a service discovery function. Optionally, the NRF network element <NUM> can further maintain information about a valid network function network element in a core network. Optionally, the NRF network element <NUM> can further maintain a service supported by the valid network function network element in the core network.

In the <NUM> communications system shown in <FIG>, in a registration process, the user equipment <NUM> selects an initial AMF network element (for example, the AMF network element <NUM>) by using the RAN device <NUM>, and the initial AMF network element obtains subscription data of the user equipment <NUM> from the UDM network element <NUM>. If the initial AMF network element determines, based on the subscription data, that the initial AMF network element cannot serve the user equipment <NUM>, the initial AMF network element requests the NSSF network element <NUM> to select another AMF network element that can meet a user requirement to serve the user equipment <NUM>. After the user equipment accesses a network, the another AMF network element requests the NSSF network element <NUM> to select the appropriate NRF network element <NUM>. Then, the AMF network element <NUM> may learn of, by requesting the NRF network element <NUM>, information about the SMF network element <NUM> that meets the requirement, and thereby perform session establishment, modification, or release by using the SMF network element <NUM>.

The foregoing network elements may be network elements implemented on dedicated hardware, software instances running on dedicated hardware, or instances of virtualized functions on an appropriate platform. For example, the foregoing virtualization platform may be a cloud platform.

In addition, the embodiments of this application may be further applicable to another future-oriented communications technology. The network architecture and the service scenario described in this application are used to describe the technical solutions in this application more clearly, and do not constitute a limitation on the technical solutions provided in this application. A person of ordinary skill in the art may know that, with evolution of network architectures and emergence of new service scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

The following uses the <NUM> communications system shown in <FIG> as an example, to describe in detail the technical solutions of this application with some embodiments. The following several embodiments may be combined with each other, and same or similar concepts or processes may not be described repeatedly in some embodiments.

<FIG> shows a network slicing-based communication method according to an embodiment of this application. According to the method, a RAN device may determine a first AMF network element that can support a network slice required by user equipment, and the first AMF network element determines, based on a requirement of the user equipment, a network slice instance that is in the network slice and that serves the user equipment. As shown in <FIG>, the method may include the following steps.

S301: The user equipment obtains first information and second information. The first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice.

For example, the user equipment is the user equipment <NUM> in <FIG>. The first information may be first S-NSSAI. The first network slice instance that is indicated by the first S-NSSAI and that is in the network slice is a first NSI. The second information may be information about the first NSI. For example, the information about the first NSI may be an identifier (identifier, ID) of the first NSI.

For example, the user equipment may obtain the first information and the second information in any one of the following three manners.

In a first possible implementation, the user equipment may obtain the first information and the second information in a registration process.

For example, the user equipment receives a registration accept message from a second AMF network element, to obtain the first information and the second information. The registration accept message includes the first information and the second information. The second AMF network element supports the type of the first network slice and the first network slice instance.

For example, before moving, the user equipment accesses the first network slice instance in the first network slice by using the second AMF network element after registering with the network, and establishes a session by using a network element in the first network slice instance. In this registration process, the second AMF network element may obtain network slice selection assistance information (Network Slice Selection Assistance Information, NSSAI) allowed by the current network. NSSAI is a set of S-NSSAI. The allowed NSSAI represents a network slice type that the user equipment can use in the current network. One or more network slice instances may be deployed in each network slice corresponding to a piece of S-NSSAI in the allowed NSSAI. For example, the network slices corresponding to the S-NSSAI in the allowed NSSAI and the network slice instances have correspondences shown in Table <NUM>. In the example of Table <NUM>, the allowed NSSAI includes S-NSSAI-<NUM> and S-NSSAI-<NUM>. Network slice instances deployed in a network slice corresponding to S-NSSAI-<NUM> include NSI-<NUM> and NSI-<NUM>*, and network slice instances deployed in a network slice corresponding to S-NSSAI-<NUM> include NSI-<NUM> and NSI-<NUM>*.

In the registration process, the network may determine, based on a load status of current different network slice instances or based on a type of the user equipment, a network slice instance that is in the network slice corresponding to the S-NSSAI in the allowed NSSAI and that serves the user equipment. In this way, the second AMF network element may obtain information about the network slice instances corresponding to the S-NSSAI in the allowed NSSAI. For example, the second AMF network element obtains correspondences between the network slices corresponding to the S-NSSAI in the allowed NSSAI and network slice instances that serve the user equipment as shown in Table <NUM>. In the example of Table <NUM>, the allowed NSSAI includes S-NSSAI-<NUM> and S-NSSAI-<NUM>. A network slice instance that is in the network slice corresponding to S-NSSAI-<NUM> obtained by the second AMF network element and that serves the user equipment is NSI-<NUM>, and a network slice instance that is in the network slice corresponding to S-NSSAI-<NUM> and that serves the user equipment is NSI-<NUM>.

The correspondences that are obtained by the second AMF network element and that are between the network slices corresponding to the S-NSSAI in the allowed NSSAI and the network slice instances that serve the user equipment include information about the first network slice, that is, the first information. For example, the first information is S-NSSAI-<NUM>. The correspondences further include information about the first network slice instance in the first network slice, that is, the second information. For example, the second information is information about NSI-<NUM>.

Further, the second AMF network element may obtain a plurality of correspondences between the network slices corresponding to the S-NSSAI in the allowed NSSAI and the network slice instances serving the user equipment. The first information may include the type of the first network slice that is in the plurality of correspondences and that is associated with the session of the user equipment before the movement. Correspondingly, the second information may include information about the first network slice instance corresponding to the first network slice. For example, the plurality of correspondences obtained by the user equipment include a correspondence between S-NSSAI-<NUM> and NSI-<NUM> and a correspondence between S-NSSAI-<NUM> and NSI-<NUM>. The first information includes S-NSSAI-<NUM> in Table <NUM>, and the second information includes the network slice instance NSI-<NUM> corresponding to S-NSSAI-<NUM>.

Further, optionally, if the user equipment establishes a plurality of sessions before the movement, the first information may include types of a plurality of first network slices associated with the plurality of sessions. Correspondingly, the second information may include a plurality of first network slice instances respectively corresponding to the plurality of first network slices. For example, before the movement, the user equipment separately accesses, by using two sessions, network slices corresponding to S-NSSAI-<NUM> and S-NSSAI-<NUM>. The first information includes S-NSSAI-<NUM> and S-NSSAI-<NUM> in Table <NUM>, and the second information includes the network slice instance NSI-<NUM> corresponding to S-NSSAI-<NUM> and the network slice instance NSI-<NUM> corresponding to S-NSSAI-<NUM>.

Then, the second AMF network element sends the correspondence to the user equipment by using the registration accept message, so that the user equipment obtains the first information and the second information. For example, before the movement, the user equipment establishes a session by using the first network slice instance NSI-<NUM> in the first network slice corresponding to S-NSSAI-<NUM>. After the movement, the user equipment requests the first network slice associated with the session before the movement to continue serving the user equipment. In this case, the user equipment may learn, based on the correspondences shown in Table <NUM>, that the network slice instance in the network slice corresponding to S-NSSAI-<NUM> is NSI-<NUM>. Therefore, the user equipment requests to access, in a new network, NSI-<NUM> in the first network slice corresponding to the S-NSSAI-<NUM>, and establish a session.

In a second possible implementation, the user equipment may obtain the first information and the second information in a session establishment process.

For example, in the session establishment process, the user equipment receives a session establishment accept message from a third AMF network element. The session establishment accept message includes the first information and the second information. The third AMF network element supports the type of the first network slice and the first network slice instance. A process in which the user equipment obtains the first information and the second information from the third AMF network element by using the session establishment accept message may be further described with reference to <FIG>.

In a third possible implementation, the user equipment receives the first information and the second information from an interworking network element. The interworking network element supports a session management function of a first network and a session management function of a second network. For example, the interworking network element supports a control plane function of a PGW network element in <NUM>th-generation (the <NUM>th-Generation, <NUM>) communications, and can communicate with an MME network element; and the interworking network element further supports a function of an SMF network element in <NUM>, and can communicate with an AMF network element. A process in which the user equipment receives the first information and the second information from the interworking network element may be further described with reference to <FIG>.

S302: The user equipment sends a registration request to the RAN device. Correspondingly, the RAN device receives the registration request from the user equipment. The registration request includes the first information and the second information, the first information and the second information are used for determining the first AMF network element, and the first information and the second information are further used for determining the network slice instance that is in the first network slice and that serves the user equipment.

For example, the RAN device is the RAN device <NUM> in <FIG>.

S303: The RAN device determines the first AMF network element based on the type of the first network slice and the first network slice instance.

For example, the first AMF network element is the AMF network element <NUM> in <FIG>. For example, the RAN device obtains, in step S302, the type of the first network slice and the first network slice instance that are requested by the user equipment, and the RAN device determines the first AMF network element based on the type of the first network slice and the first network slice instance. For example, if the RAN device determines that types of network slices supported by the first AMF network element include the type of the first network slice, and network slice instances supported by the first AMF network element include the first network slice instance, the RAN device determines that the first AMF network element can serve the user equipment. A process in which the first AMF determines the network slice instance serving the user equipment may be further described subsequently in step S305. If the RAN device determines that types of network slices supported by the first AMF network element include the type of the first network slice, but network slice instances supported by the first AMF network element do not include the first network slice instance, and in the network, and there is no other AMF network element that supports both the type of the first network slice and the first network slice instance, the RAN device also temporarily determines that the first AMF network element serves the user equipment. A process in which the first AMF network element determines the network slice instance serving the user equipment may be further described with reference to subsequent step S305 and <FIG>. A process in which the RAN device determines the first AMF network element is further described with reference to <FIG>.

S304: The RAN device sends the foregoing registration request to the first AMF network element. Correspondingly, the first AMF network element receives the registration request from the RAN device. The first information and the second information are used for determining the network slice instance.

S305: The first AMF network element determines, based on the first information and the second information, the network slice instance that is in the first network slice and that serves the user equipment.

For example, the first AMF network element obtains, in step S304, the type of the first network slice and the first network slice instance that are requested by the user equipment. If the network slice instances supported by the first AMF network element include the first network slice instance in the network slice corresponding to the type of the first network slice, the first AMF network element determines that the network slice instance that is in the first network slice and that serves the user equipment is the first network slice instance. If the network slice instances supported by the first AMF network element do not include the first network slice instance, a process in which the first AMF network element determines the network slice instance serving the user equipment may be further described with reference to <FIG>.

According to the method in this embodiment of the present invention, a core network can select the network slice instance that meets a requirement of the user equipment to serve the user equipment. When the user equipment moves, the user equipment may learn of the network slice instance that serves the user equipment before the movement. After the movement, the user equipment requests the same network slice instance from the core network, to ensure that the session established before the user equipment moves is not interrupted, thereby improving user experience.

<FIG> shows a method for determining a network slice instance to serve user equipment according to an embodiment of this application. The method may be used in a scenario in which the network slice instances supported by the first AMF network element serving the user equipment do not include the first network slice instance requested by the user equipment in <FIG>. As shown in <FIG>, the method may include the following steps.

S401: A first AMF network element sends first information and indication information to an NSSF network element. Correspondingly, the NSSF network element receives the first information and the indication information from the first AMF network element. The first information is used to indicate a type of a first network slice, and the indication information is used to request to determine a network slice instance that is in the first network slice and that serves user equipment.

For example, the NSSF network element is the NSSF network element <NUM> in <FIG>, and the first information may be first S-NSSAI. Optionally, the first AMF network element further sends current location information of the user equipment to the NSSF network element, so that the NSSF network element learns of a network slice instance that is in the first network slice and that can be used by the user equipment at a current location. For example, the current location information of the user equipment may be a tracking area identity (Tracking Area Identity, TAI).

S402: The NSSF network element sends identification information of a second network slice instance to the first AMF network element. Correspondingly, the first AMF network element receives the identification information of the second network slice instance from the NSSF network element. The identification information of the second network slice instance is used to identify the second network slice instance. The second network slice instance is the network slice instance determined by the NSSF network element to serve the user equipment, and the second network slice instance is the network slice instance that is in the first network slice and that can be used by the user equipment at the current location.

For example, the identification information of the second network slice instance may be an ID of a second NSI. The second NSI is a network slice instance in a network slice corresponding to the first S-NSSAI.

S403: The first AMF network element sends the identification information of the second network slice instance to the user equipment. Correspondingly, the user equipment receives the identification information of the second network slice instance from the first AMF network element.

For example, the user equipment is the user equipment <NUM> in <FIG>.

According to the method in this embodiment of the present invention, when an AMF network element serving the user equipment does not support the network slice instance requested by the user equipment, a core network may select a network slice instance supported by the AMF network element to serve the user equipment. In addition, the core network sends, to the user equipment, information about the network slice instance selected to serve the user equipment, so that after next movement, the user equipment requests the core network to select the same network slice instance to serve the user equipment. In this way, it can be ensured that a session currently established by the user equipment is not interrupted after the next movement, thereby improving user experience.

<FIG> shows a method for determining an AMF network element by a RAN device according to a claimed embodiment of this application. According to the method, the RAN device may select, based on a type of a network slice and a network slice instance that are requested by the user equipment, the AMF network element to serve the user equipment. As shown in <FIG>, the method may include the following steps.

S501: A first AMF network element sends capability information to the RAN device. Correspondingly, the RAN device receives the capability information from the first AMF network element. The capability information is used to indicate a network slice type and a network slice instance that are supported by the AMF network element.

For example, the first AMF network element is the AMF network element <NUM> in <FIG>, the RAN device is the RAN device <NUM> in <FIG>, the network slice type may be represented by S-NSSAI, and the network slice instance may be represented by NSI. For example, the first AMF network element has the capability information shown in Table <NUM>. In the example of Table <NUM>, network slice types supported by the first AMF network element include S-NSSAI-<NUM> and S-NSSAI-<NUM>. Network slice instances in a network slice corresponding to S-NSSAI-<NUM> supported by the first AMF network element include NSI-<NUM> and NSI-<NUM>*, and network slice instances in a network slice corresponding to S-NSSAI-<NUM> supported by the first AMF network element include NSI-<NUM> and NSI-<NUM>*.

Similarly, the RAN device may further receive, from another AMF network element communicating with the RAN device, capability information of the another AMF network element. The capability information of the another AMF network element may have a same format as that in Table <NUM>, and details are not described herein again. In this way, the RAN device obtains capability information of each AMF network element that communicates with the RAN device, for subsequent AMF network element selection.

S502: The RAN device determines the first AMF network element based on a type of a first network slice, a first network slice instance, and the capability information.

For example, the RAN device obtains the capability information of the first AMF network element and the capability information of the another AMF network element according to the foregoing step S501. In a registration process, the RAN device obtains, according to step S302 in <FIG>, the type of the first network slice and the first network slice instance that are requested by the user equipment. For example, if the type of the first network slice is S-NSSAI-<NUM>, and the first network slice instance is NSI-<NUM>, the RAN device learns in step S303, based on the capability information of the first AMF network element in Table <NUM>, that the network slice types supported by the first AMF network element include the type of the first network slice, and network slice instances that are supported by the first AMF network element and that correspond to the type of the first network slice include the first network slice instance. In this way, the RAN device determines the first AMF network element to serve the user equipment.

If the user equipment establishes a plurality of sessions before movement, the first information obtained in step S302 in <FIG> may include types of a plurality of first network slices associated with the plurality of sessions. Correspondingly, the second information may include a plurality of first network slice instances respectively corresponding to the plurality of first network slices. For example, the first information includes S-NSSAI-<NUM> and S-NSSAI-<NUM> in Table <NUM>, and the second information includes the network slice instance NSI-<NUM> corresponding to S-NSSAI-<NUM> and the network slice instance NSI-<NUM> corresponding to S-NSSAI-<NUM>. In this case, in step S502, the RAN device may select, based on the obtained capability information of each AMF network element, an AMF network element that supports both the network slice instance NSI-<NUM> corresponding to S-NSSAI-<NUM> and the network slice instance NSI-<NUM> corresponding to S-NSSAI-<NUM> as the first AMF network element.

According to the method in this embodiment of the present invention, the RAN device may learn of capabilities of the AMF network elements, and then select an AMF network element that supports the network slice type and the network slice instance that are requested by the user equipment, to serve the user equipment. Then, the AMF network element may select the network slice instance requested by the user equipment to serve the user equipment, to ensure that a session established before the user equipment moves is not interrupted, thereby improving user experience.

<FIG> shows a method for obtaining first information and second information by user equipment from a third AMF network element in a session establishment process according to an embodiment of this application. As shown in <FIG>, the method may include the following steps.

S601: The user equipment sends the first information to the third AMF network element. Correspondingly, the third AMF network element receives the first information from the user equipment. The first information is used to indicate a type of a first network slice.

For example, the user equipment is the user equipment <NUM> in <FIG>. The first information may be first S-NSSAI.

For example, before movement, after registering in a network, the user equipment accesses, by using the third AMF network element, a first network slice instance in a network slice corresponding to the type of the first network slice, and establishes a session by using a network element in the first network slice instance. The first S-NSSAI is S-NSSAI associated with the session. For example, the user equipment may send the first information to the third AMF network element by using a session establishment request message.

S602: The third AMF network element obtains information about an NRF network element from an NSSF network element. For example, the NSSF network element is the NSSF network element <NUM> in <FIG>.

If the third AMF network element obtains only allowed NSSAI in a registration process, that is, obtains the first S-NSSAI, the third AMF requests, from the NSSF network element, the information about the NRF network element used to select an SMF network element and information about a network slice instance corresponding to the first S-NSSAI. For example, the third AMF network element may send the first S-NSSAI to the NSSF network element by invoking an nnssf nsselection_get service, to request to obtain the information about the NRF network element.

After receiving the request from the third AMF network element, the NSSF network element returns the information about the NRF network element to the third AMF network element. For example, the NRF network element is the NRF network element <NUM> in <FIG>. For example, the NSSF network element may return the information about the NRF network element to the third AMF network element by sending an nnssf_nsselection_get response message.

S603: The third AMF network element obtains information about the SMF network element from the NRF network element.

The third AMF network element requests to obtain the information about the SMF network element from the NRF network element based on the information about the NRF network element returned by the NSSF network element in step S602. For example, the third AMF network element may send the first S-NSSAI to the NRF network element by invoking an nnrf_nfdiscovery_resquest service, to request to obtain the information about the SMF network element. After the third AMF network element invokes the nnrf_nfdiscovery_request service, the NRF network element returns the information about the SMF network element to the third AMF network element.

In a possible implementation, in step S602, the third AMF network element may further request information about the first network slice instance by invoking the nnssf nsselection_get service. In this way, the third AMF network element obtains the second information from the NSSF network element. The second information is used to identify the first network slice instance in the first network slice. For example, the second information may be an ID of a first NSI, and the first NSI is a network slice instance in a network slice corresponding to the first S-NSSAI. For example, the NSSF network element may return the second information to the third AMF network element by sending an nnssf_nsselection_get response message.

In this case, when invoking the nnrf_nfdiscovery_resquest service in step S603, the third AMF network element further sends the second information to the NRF network element. In this way, the SMF network element determined by the NRF network element is an SMF network element in the first network slice instance indicated by the second information.

In another possible implementation, in step S603, the third AMF network element may further request the information about the first network slice instance by invoking the nnrf_nfdiscovery_resquest service. If the third AMF network element does not obtain the second information in step S602, the third AMF network element does not send the second information when invoking the nnrf_nfdiscovery_request service. In this case, the NRF network element returns, to the third AMF network element, the second information and the information about the SMF network element in the first network slice instance indicated by the second information, so that the third AMF network element obtains the second information.

S604: The third AMF network element sends a session establishment request to the SMF network element. Correspondingly, the SMF network element receives the session establishment request from the third AMF network element.

For example, the SMF network element is the SMF network element <NUM> in <FIG>. The third AMF network element may send the first S-NSSAI to the SMF network element by invoking an nsmf_pdusession_createsmcontext request service, and request to establish a session.

Step S604 is an optional step. The third AMF network element may alternatively request to establish a session in another manner. This is not limited in the present invention.

S605: The SMF network element requests a UDM network element to register the session.

For example, the UDM network element is the UDM network element <NUM> in <FIG>. The UDM network element is requested to register the session, so that the UDM network element may save an address of the SMF network element and an ID of the session; and the SMF network element may obtain subscription data that is of the user equipment and that is associated with the session, and subscribe to updated subscription data of the user equipment from the UDM network element.

Step S605 is an optional step. The SMF network element may alternatively obtain the subscription data of the user equipment in another manner. This is not limited in the present invention.

S606: The SMF network element sends a session establishment response to the third AMF network element. Correspondingly, the third AMF network element receives the session establishment response from the SMF network element.

For example, after invoking the nsmf_pdusession_createsmcontext request service, the SMF network element returns the session establishment response to the third AMF network element by sending an nsmf_pdusession_createsmcontext response message.

Step S606 is an optional step. The SMF network element may alternatively return the session establishment response in another manner. This is not limited in the present invention.

S607: The third AMF network element sends the first information and the second information to the user equipment. Correspondingly, the user equipment receives the first information and the second information from the third AMF network element.

It should be noted that, different from that the user equipment receives the registration accept message from the second AMF network element to obtain the first information and the second information, in the embodiment shown in <FIG>, the first information and the second information obtained by the third AMF network element are the type of the network slice and the network slice instance that are associated with the current session of the user equipment. If the user equipment initiates establishment processes of a plurality of sessions before movement, the third AMF may perform the process in <FIG> for a plurality of times, to separately obtain information about network slice instances corresponding to each network slice associated with each session, and separately send the information to the user equipment. For example, network slices corresponding to each S-NSSAI of a plurality of sessions and network slice instances have correspondences that are shown in Table <NUM> and that are received by the user equipment. In the example of Table <NUM>, the user equipment initiates two session establishment processes: session-<NUM> and session-<NUM>. A type of a network slice used by session-<NUM> is S-NSSAI-<NUM>, and a network slice instance in a network slice corresponding to S-NSSAI-<NUM> is NSI-<NUM>. A type of a network slice used by session-<NUM> is S-NSSAI-<NUM>, and a network slice instance in a network slice corresponding to S-NSSAI-<NUM> is NSI-<NUM>.

According to the method in this embodiment of the present invention, when the user equipment obtains only the allowed NSSAI in the registration process, the user equipment can obtain, in the session establishment process, the information about the network slice instance corresponding to the S-NSSAI associated with the session. After the user equipment moves, the user equipment may request, from a core network, the network slice instance associated with the current session to serve the user equipment, to ensure that the session established before the user equipment moves is not interrupted, thereby improving user experience.

<FIG> shows a method for receiving first information and second information by user equipment from an interworking network element according to an embodiment of this application. The method may be used in a scenario in which the user equipment supports interworking between <NUM> and <NUM>. As shown in <FIG>, the method may include the following steps.

S701: The user equipment sends a connection request to an MME network element. Correspondingly, the MME network element receives the connection request from the user equipment.

For example, the user equipment is the user equipment <NUM> in <FIG>, and the user equipment is applicable to both a <NUM> network and a <NUM> network. The connection request may be a packet data network (Packet Data Network, PDN) connectivity request (PDN Connectivity Request) message. Optionally, the user equipment may further send an access point name (Access Point Name, APN) and PDU session identification information to the MME network element, to request to establish a PDN connection.

S702: The MME network element sends a session establishment request to an SGW network element. Correspondingly, the SGW network element receives the session establishment request from the MME network element.

For example, the session establishment request may be a create session request (Create Session Request) message, used to request the SGW network element to establish a default bearer. Optionally, the session establishment request message further includes an international mobile subscriber identity (International Mobile Subscriber Identifier, IMSI) and the PDU session identification information.

S703: The SGW network element sends a session establishment request to the interworking network element. Correspondingly, the interworking network element receives the session establishment request from the SGW network element.

For example, the interworking network element supports both a control plane function of a PGW network element in <NUM> communication and a function of an SMF network element in <NUM>. The session establishment request may be a create session request message. The SGW network element creates a new evolved packet system (Evolved Packet System, EPS) bearer in an EPS bearer list, and sends the create session request message to the interworking network element.

S704: The interworking network element initiates a session modification request to a user plane network element. The session modification request includes an internet protocol (Internet Protocol, IP) address of a session.

For example, the user plane network element supports both a user plane function of a PGW network element in <NUM> communication and a function of a UPF network element in <NUM>.

S705: The interworking network element sends the first information and the second information to the SGW network element. Correspondingly, the SGW network element receives the first information and the second information from the interworking network element. The first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice. The first network slice serves the user equipment in the <NUM> network. In this case, the interworking network element is an SMF network element in the first network slice instance.

For example, the first information may be first S-NSSAI, and the second information may be an ID of a first NSI. The first NSI is a network slice instance in a network slice corresponding to the first S-NSSAI. Because the interworking network element supports the function of an SMF network element in <NUM>, a type of a network slice corresponding to the SMF network element and a corresponding network slice instance are configured in the interworking network element. In a PDN connection process of <NUM> communication, the interworking network element may determine, based on the foregoing configuration, the type of the first network slice serving the user equipment in the <NUM> network and the first network slice instance. For example, the interworking network element may send the first information and the second information to the SGW network element by using a create session request message.

S706: The SGW network element sends the first information and the second information to the MME network element. Correspondingly, the MME network element receives the first information and the second information from the SGW network element.

For example, the SGW network element may send the first information and the second information to the MME network element by using a create session request message.

S707: The MME network element sends the first information and the second information to an eNB device. Correspondingly, the eNB device receives the first information and the second information from the MME network element.

For example, the MME network element may send the first information and the second information to the eNB by using a PDN connectivity accept (PDN Connectivity Accept) message.

S708: The eNB device sends the first information and the second information to the user equipment. Correspondingly, the user equipment receives the first information and the second information from the eNB device.

For example, the eNB device may send the first information and the second information to the user equipment by using a PDN connectivity accept message.

According to the method in this embodiment of the present invention, when the user equipment supports interworking between <NUM> and <NUM>, after creating PDN connectivity in the <NUM> network, the user equipment can obtain the information about the network slice instance corresponding to S-NSSAI associated with the session. When the user equipment uses the <NUM> network, the user equipment may request, from the core network, the network slice instance associated with the current session to serve the user equipment, to ensure that the session established when the user equipment switches from the <NUM> network to the <NUM> network is not interrupted, thereby improving user experience.

<FIG> shows another network slicing-based communication method according to an embodiment of this application. The method may be used in a scenario in which a core network determines, based on a type of a network slice and information about a network slice instance that are stored in a UDM network element, a network slice instance to serve user equipment. As shown in <FIG>, the method may include the following steps.

S801: A first AMF network element sends first information and second information to the UDM network element. Correspondingly, the UDM network element receives the first information and the second information from the first AMF network element. The first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice.

For example, the first AMF network element is an AMF network element in a network in which the user equipment is located before movement, and the UDM network element is the UDM network element <NUM> in <FIG>. The first information may be first S-NSSAI, and the second information may be an ID of a first NSI. The first NSI is a network slice instance in a network slice corresponding to the first S-NSSAI.

For example, the first AMF network element may send the first information and the second information to the UDM network element in either of the following two implementations.

In a possible implementation, the first AMF network element sends the first information and the second information to the UDM network element in a registration process. For example, in the registration process, after receiving a session establishment response message returned by an SMF network element, the first AMF network element sends, to the UDM network element, information about a network slice instance corresponding to S-NSSAI in allowed NSSAI. For a correspondence between a network slice corresponding to the S-NSSAI in the allowed NSSAI received by the UDM network element and a network slice instance serving the user equipment, refer to Table <NUM> in the embodiment of <FIG>.

In another possible implementation, the first AMF network element sends the first information and the second information to the UDM network element in a session establishment process. For obtaining the second information by the first AMF network element, refer to the description of step S602 or S603 in the embodiment of <FIG>. After obtaining the second information, the first AMF network element sends the first information and the second information to the UDM network element.

S802: The UDM network element sends the first information and the second information to a second AMF network element. Correspondingly, the second AMF network element receives the first information and the second information from the UDM network element.

For example, the second AMF network element is an AMF network element that the user equipment accesses in a network after the movement.

For example, after receiving a registration request of the user equipment, the second AMF network element requests, from the UDM network element, to obtain a context of the user equipment. After receiving a request message sent by the second AMF network element for obtaining the context of the user equipment, the UDM network element sends the first information and the second information to the second AMF network element.

S803: When the second AMF network element does not support the first network slice instance identified by the second information, the second AMF network element sends the first information, the second information, and indication information to an NSSF network element. Correspondingly, the NSSF network element receives the first information, the second information, and the indication information from the second AMF network element. The indication information is used to request to determine a third AMF network element that supports the type of the first network slice and the first network slice instance.

For example, the NSSF network element is the NSSF network element <NUM> in <FIG>. After receiving the first information and the second information, the second AMF network element determines that the second AMF network element cannot support the first network slice instance in the first network slice, and therefore requests the NSSF network element to select, based on the first information and the second information, the third AMF network element that supports the type of the first network slice and the first network slice instance to serve the user equipment.

Optionally, the second AMF network element sends current location information of the user equipment to the NSSF network element, so that the NSSF network element can select the third AMF network element that can serve the user equipment at a current location of the user equipment. For example, the current location information of the user equipment may be a TAI.

S804: The NSSF network element determines whether the third AMF network element exists in an area in which the user equipment is located.

For example, the user equipment is the user equipment <NUM> in <FIG>. If the third AMF network element that can support the type of the first network slice and the first network slice instance exists in the area in which the user equipment is located, the NSSF network element sends identification information of the third AMF network element to the second AMF network element. This process may be further described with reference to <FIG>. If no third AMF network element that can support the type of the first network slice and the first network slice instance exists in the area in which the user equipment is located, the NSSF determines a second network slice instance supported by the second AMF network element to serve the user equipment. This process may be further described with reference to <FIG> and <FIG>.

According to the method in this embodiment of the present invention, before the user equipment moves, a network slice instance serving the user equipment is stored in the core network. After the user equipment moves, the core network can select a network slice instance that is the same as that before the movement to serve the user equipment. In this way, it is ensured that a session established before the user equipment moves is not interrupted, thereby improving user experience. In addition, compared with the method provided in the embodiment of <FIG>, in the method provided in this embodiment of the present invention, the core network stores the information about the network slice instance that is before the movement, and the user equipment and the RAN device do not need to learn of the information about the network slice instance, thereby saving storage space of the user equipment.

<FIG> shows another network slicing-based communication method according to an embodiment of this application. The method may be used in a scenario in which when an NSSF network element determines that a third AMF network element that supports a first network slice instance exists in an area in which user equipment is located, the NSSF network element determines the third AMF network element to serve the user equipment. <FIG> is described with reference to <FIG>. As shown in <FIG>, the method may include the following steps.

S901: The user equipment sends a registration request to a RAN device. Correspondingly, the RAN device receives the registration request from the user equipment.

For example, the user equipment is the user equipment <NUM> in <FIG>, and the RAN device is the RAN device <NUM> in <FIG>. The registration request may be used by the user equipment to request to register at the network side after the user equipment moves. Optionally, the registration request may include NSSAI requested by the user equipment and a temporary identifier allocated by a first AMF network element for the user equipment. The first AMF network element is an AMF network element that the user equipment accesses before the movement. For example, the temporary identifier may be a <NUM> globally unique temporary identity (Globally Unique Temporary Identity, GUTI).

S902: The RAN device determines a second AMF network element.

For example, when the RAN device cannot connect to the first AMF network element based on the temporary identifier, the RAN device selects, based on the requested NSSAI, the second AMF network element to serve the user equipment. The second AMF network element can support a network slice corresponding to the NSSAI requested by the user equipment.

S903: The RAN device sends a registration request to the second AMF network element. Correspondingly, the second AMF network element receives the registration request from the RAN device.

S904: The second AMF network element obtains first information and second information from a UDM network element. The first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice.

For example, the UDM network element is the UDM network element <NUM> in <FIG>. The first information may be first S-NSSAI, and the second information may be an ID of a first NSI. The first NSI is a network slice instance in a network slice corresponding to the first S-NSSAI. For example, the first network slice instance is a network slice instance that serves the user equipment before the user equipment moves.

After the second AMF network element receives the registration request in step S903, because the second AMF network element cannot obtain a context of the user equipment from the first AMF network element that allocates the temporary identifier, the second AMF network element obtains the context of the user equipment from the UDM network element when registering with the UDM network element. In addition, the second AMF network element further obtains the first information and the second information from the UDM network element. For example, the UDM network element may obtain the first information and the second information through step S801 in <FIG>.

S905: The second AMF network element determines that the first network slice instance is not supported.

For example, through step S904, the second AMF network element learns that, before the movement, the user equipment uses a network slice instance NSI-<NUM> in a network slice corresponding to S-NSSAI-<NUM>. However, capability information of the second AMF network element does not include NSI-<NUM>. Therefore, the second AMF network element determines that NSI-<NUM> is not supported.

S906: The second AMF network element sends the first information, the second information, and indication information to the NSSF network element. Correspondingly, the NSSF network element receives the first information, the second information, and the indication information from the second AMF network element. The indication information is used to request to determine a third AMF network element that supports the type of the first network slice and the first network slice instance.

For step S906, refer to the description of step S803 in <FIG>.

S907: The NSSF network element determines that the third AMF network element exists in the area in which the user equipment is located.

For example, the NSSF network element determines, based on the first information and the second information, that the third AMF network element supporting the type of the first network slice and the first network slice instance exists in the area in which the user equipment is located.

S908: The NSSF network element sends identification information of the third AMF network element to the second AMF network element. Correspondingly, the second AMF network element receives the identification information of the third AMF network element from the NSSF network element.

S909: The second AMF network element sends the identification information of the third AMF network element to the RAN device. Correspondingly, the RAN device receives the identification information of the third AMF network element from the second AMF network element.

Optionally, after step S909 is performed, the RAN device performs step S910.

S910: The RAN device sends a redirection message to the third AMF network element. Correspondingly, the third AMF network element receives the redirection message from the RAN device. The redirection message is used to request the third AMF network element to serve the user equipment.

According to the method in this embodiment of the present invention, after the user equipment moves, the core network can obtain, from the UDM network element, information about the first network slice instance that serves the user equipment before the movement, and then select an AMF network element that supports the first network slice instance to serve the user equipment. In this way, it is ensured that a session established before the user equipment moves is not interrupted, thereby improving user experience. In addition, compared with the method provided in the embodiment of <FIG>, in the method provided in this embodiment of the present invention, the UDM network element in the core network stores the information about the network slice instance that is before the movement, and the user equipment and the RAN device do not need to learn of the information about the network slice instance, thereby saving storage space of the user equipment.

<FIG> and <FIG> show another network slicing-based communication method according to an embodiment of this application. The method may be used in a scenario in which when an NSSF network element determines that a third AMF network element that supports a first network slice instance does not exist in an area in which user equipment is located, the NSSF network element determines a network slice instance to serve the user equipment. <FIG> and <FIG> are described with reference to <FIG>.

For step S1001 to step <NUM>, refer to the description of step S901 to S906 in <FIG>.

In the example in <FIG> and <FIG>, the method may further include the following steps.

S1007: The NSSF network element determines that the third AMF network element does not exist in the area in which the user equipment is located.

For example, the NSSF network element determines, based on the first information and the second information, that the third AMF network element supporting the first network slice instance in the type of the first network slice does not exist in the area in which the user equipment is located.

S1008: The NSSF network element sends identification information of second network slice instance to the second AMF network element. Correspondingly, the second AMF network element receives the identification information of the second network slice instance from the NSSF network element. The second network slice instance is a network slice instance that is in a network slice corresponding to the type of the first network slice and that is determined by the NSSF network element to serve the user equipment. The second AMF network element supports the second network slice instance.

For example, the identification information of the second network slice instance may be an ID of a second NSI.

S1009: The second AMF network element sends the identification information of the second network slice instance to the UDM network element. Correspondingly, the UDM network element receives the identification information of the second network slice instance from the second AMF network element.

Optionally, after step S1009 is performed, the UDM network element performs step S1010.

S1010: The UDM network element saves the identification information of the second network slice instance.

For example, before step S1009, the UDM network element stores the type of the first network slice serving the user equipment before the user equipment moves and identification information of the first network slice instance serving the user equipment before the user equipment moves. Through step S1010, the UDM network element saves the type of the first network slice serving the user equipment after the user equipment moves and the identification information of the second network slice instance serving the user equipment after the user equipment moves.

S1011: The UDM network element sends a deregistration request to the first AMF network element. Correspondingly, the first AMF network element receives the deregistration request from the UDM network element. The deregistration request includes the identification information of the first network slice and the identification information of the second network slice instance.

Optionally, after S1011 is performed, the first AMF network element performs step S1012.

S1012: The first AMF network element releases a session.

For example, the first AMF network element learns that the user equipment uses the second network slice instance, determines that the session established by the user equipment by using the first network slice instance before the movement cannot be maintained, and therefore releases the session established in the first network slice instance.

According to the method in this embodiment of the present invention, when there is no AMF network element, in a network, supporting the network slice instance requested by the user equipment, a core network may select a network slice instance supported by an AMF network element to serve the user equipment. In addition, the core network saves information about the network slice instance selected to serve the user equipment, so that after the user equipment moves next time, the core network can select the same network slice instance to serve the user equipment. In this way, it can be ensured that the session currently established by the user equipment is not interrupted after the next movement, thereby improving user experience. In addition, the core network may further notify an original AMF network element connected to the user equipment before the movement that the user equipment uses a different network slice instance after the movement. In this way, the original AMF network element releases the session, so that signaling processing load of the original AMF network element is reduced.

In the foregoing embodiments provided in this application, the solutions of the communication method provided in the embodiments of this application are separately described from perspectives of each network element and interaction between the network elements. It may be understood that, to implement the foregoing functions, each network element and device, for example, the radio access network device, the access and mobility management function network element, the user equipment, the data management function network element, and the network slice selection function network element, include a corresponding hardware structure and/or software module for performing each function. A person skilled in the art should easily be aware that, with reference to the units and algorithm steps of the examples described in the embodiments disclosed in this specification, this application may be implemented by hardware or a combination of hardware and computer software. Whether a function is performed by hardware or hardware driven by computer software depends on particular applications and design constraints of the technical solutions. A person skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation departs from the scope of this application.

For example, when the foregoing network elements implement corresponding functions by using software modules, a network slicing-based communications apparatus may include a receiving module <NUM>, a processing module <NUM>, and a sending module <NUM>, as shown in <FIG>.

In an embodiment, the network slicing-based communications apparatus may be configured to perform operations of the radio access network device (for example, a RAN device) in <FIG> and <FIG>. For example:.

The receiving module <NUM> is configured to receive a registration request from user equipment. The registration request includes first information and second information. The first information is used to indicate a type of the first network slice (for example, first S-NSSAI), and the second information is used to identify a first network slice instance in the first network slice (for example, a first NSI ID). The processing module <NUM> is configured to determine an access and mobility management function network element based on the type of the first network slice and the first network slice instance. The sending module <NUM> is configured to send a registration request to the access and mobility management function network element (for example, an AMF network element). The first information and the second information are used for determining a network slice instance.

In this way, in this embodiment of the present invention, the network slicing-based communications apparatus can select an access and mobility management function network element that supports the type of the first network slice and the first network slice instance to serve the user equipment. The access and mobility management function network element further determines, based on a requirement of the user equipment, a network slice instance that can serve the user equipment. When the user equipment moves, the user equipment may learn of a network slice instance that serves the user equipment before the movement. After the movement, the user equipment requests the same network slice instance from the core network, to ensure that a session established before the user equipment moves is not interrupted, thereby improving user experience.

Optionally, the receiving module <NUM> is further configured to receive capability information from the access and mobility management function network element. The capability information is used to indicate a network slice type and a network slice instance that are supported by the access and mobility management function network element. That the processing module <NUM> determines the access and mobility management function network element based on the type of the first network slice and the first network slice instance includes: determining, by the processing module <NUM>, the access and mobility management function network element based on the type of the first network slice, the first network slice instance, and the capability information.

Optionally, the access and mobility management function network element determined by the processing module <NUM> supports the type of the first network slice and the first network slice instance.

In addition, the receiving module <NUM>, the processing module <NUM>, and the sending module <NUM> in the network slicing-based communications apparatus may further implement other operations or functions of the radio access network device in the foregoing method.

In another embodiment, the network slicing-based communications apparatus shown in <FIG> may be alternatively configured to perform operations of the first access and mobility management function network element (for example, the first AMF network element) in <FIG> and <FIG>. For example:.

A receiving module <NUM> is configured to receive a registration request from a radio access network device (for example, a RAN device). The registration request includes first information and second information. The first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice. A processing module <NUM> is configured to determine, based on the first information and the second information, a network slice instance that is in the first network slice and that serves user equipment.

In this way, by using the network slicing-based communications apparatus of a network slice in this embodiment of the present invention, a core network may determine, based on a requirement of the user equipment, a network slice instance that can serve the user equipment. When the user equipment moves, the user equipment may learn of a network slice instance that serves the user equipment before the movement. After the movement, the user equipment requests the same network slice instance from the core network, to ensure that a session established before the user equipment moves is not interrupted, thereby improving user experience.

Optionally, the network slicing-based communications apparatus further includes a sending module <NUM>, configured to send capability information to the radio access network device. The capability information is used to indicate the type of the first network slice and a network slice instance that is in the first network slice and that is supported by the network slicing-based communications apparatus. The capability information is used for determining the network slicing-based communications apparatus.

Optionally, the network slice instance that is in the first network slice and that serves the user equipment is the first network slice instance.

Optionally, that the processing module <NUM> determines, based on the first information and the second information, the network slice instance that is in the first network slice and that serves the user equipment includes: when the network slicing-based communications apparatus does not support the first network slice instance identified by the second information, sending, by the sending module <NUM>, the first information and indication information to a network slice selection function network element (for example, an NSSF network element). The indication information is used to request to determine the network slice instance that is in the first network slice and that serves the user equipment. The receiving module <NUM> receives, from the network slice selection function network element, identification information (for example, a second NSI ID) of a second network slice instance that is in the first network slice and that is supported by the network slicing-based communications apparatus.

Optionally, the sending module <NUM> is further configured to send the identification information of the second network slice instance to the user equipment.

In addition, the receiving module <NUM>, the processing module <NUM>, and the sending module <NUM> in the network slicing-based communications apparatus may further implement other operations or functions of the access and mobility management function network element in the foregoing method.

In another embodiment, the apparatus shown in <FIG> may be alternatively configured to perform operations of the user equipment in <FIG>, <FIG>, <FIG>, and <FIG>. For example:.

A receiving module <NUM> is configured to obtain first information and second information. The first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice. A sending module <NUM> is configured to send a registration request to a radio access network device. The registration request includes the first information and the second information, the first information and the second information are used for determining a first access and mobility management function network element, and the first information and the second information are further used for determining a network slice instance that is in the first network slice and that serves user equipment.

In this way, the user equipment in this embodiment of the present invention can obtain information about a network slice instance that the user equipment accesses before moving. After the user equipment moves, the user equipment may request, from a core network, the same network slice instance to serve the user equipment, to ensure that a session established before the user equipment moves is not interrupted, thereby improving user experience.

Optionally, that the receiving module <NUM> obtains the first information and the second information includes: receiving, by the receiving module <NUM>, a registration accept message from a second access and mobility management function network element (for example, a second AMF network element), where the registration accept message includes the first information and the second information, and the second access and mobility management function network element supports the type of the first network slice and the first network slice instance; receiving, by the receiving module <NUM>, a session establishment accept message from a third access and mobility management function network element (for example, a third AMF network element), where the session establishment accept message includes the first information and the second information, and the third access and mobility management function network element supports the type of the first network slice and the first network slice instance; or receiving, by the receiving module <NUM>, the first information and the second information from an interworking network element, where the interworking network element supports a session management function of a first network and a session management function of a second network.

In addition, the receiving module <NUM> and the sending module <NUM> in the user equipment may further implement other operations or functions of the user equipment in the foregoing method.

In another embodiment, the network slicing-based communications apparatus shown in <FIG> may be alternatively configured to perform operations of the second access and mobility management function network element (for example, the second AMF network element) in <FIG>, <FIG>, and <FIG> and <FIG>. For example:
A receiving module <NUM> is configured to: after receiving a registration request, receive first information and second information from a data management function network element (for example, a UDM network element). The first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice. When the network slicing-based communications apparatus based on the network slice does not support the first network slice instance identified by the second information, a sending module <NUM> is configured to send the first information, the second information, and indication information to a network slice selection function network element (for example, an NSSF network element). The indication information is used to request to determine an access and mobility management function network element that supports the type of the first network slice and the first network slice instance.

In this way, by using the network slicing-based communications apparatus in this embodiment of the present invention, assuming that user equipment accesses the first network slice instance in the first network slice before moving, the user equipment stores the type of the first network slice and information about the first network slice instance in the data management function network element. After the user equipment moves, a first access and mobility management function network element requests the network slice selection function network element to select the second access and mobility management function network element that supports the first network slice type and the first network slice instance to serve the user equipment. Thereby, the second access and mobility management function network element can determine a network slice instance to serve the user equipment, to ensure that a session established before the user equipment moves is not interrupted, thereby improving user experience.

Optionally, the receiving module <NUM> is further configured to receive identification information of the second network slice instance in the first network slice from the network slice selection function network element. The sending module <NUM> is further configured to send the identification information of the second network slice instance to the data management function network element.

In addition, the receiving module <NUM> and the sending module <NUM> in the network slicing-based communications apparatus may further implement other operations or functions of the second access and mobility management function network element in the foregoing method.

In another embodiment, the network slicing-based communications apparatus shown in <FIG> may be alternatively configured to perform operations of the data management function network element (for example, the UDM network element) in <FIG>, <FIG>, and <FIG> and <FIG>. For example:.

A receiving module <NUM> is configured to obtain first information and second information from a first access and mobility management function network element. The first information is used to indicate a type of a network slice, the second information is used to identify a network slice instance in the network slice, and the first access and mobility management function network element supports the type of the network slice and the network slice instance. A sending module <NUM> is configured to send the first information and the second information to a second access and mobility management function network element. The first information and the second information are used for determining a third access and mobility management function network element, and the third access and mobility management function network element supports the type of the network slice and the network slice instance.

In this way, by using the network slicing-based communications apparatus in this embodiment of the present invention, before user equipment moves, a core network stores information about a network slice instance that serves the user equipment; and after the user equipment moves, the core network can select a network slice instance that is the same as that before the movement to serve the user equipment. In this way, it is ensured that a session established before the user equipment moves is not interrupted, thereby improving user experience. In addition, the data management function network element stores the information about the network slice instance that is before the movement, so that the user equipment and a RAN device do not learn of the information about the network slice instance, thereby saving storage space of the user equipment.

In addition, the receiving module <NUM> and the sending module <NUM> in the network slicing-based communications apparatus may further implement other operations or functions of the data management function network element in the foregoing method.

In another embodiment, the network slicing-based communications apparatus shown in <FIG> may be alternatively configured to perform operations of the network slice selection function network element (for example, the NSSF network element) in <FIG>, <FIG>, and <FIG> and <FIG>. For example:.

A receiving module <NUM> is configured to receive first information, second information, and indication information from a first access and mobility management function network element. The first information is used to indicate a type of a first network slice, the second information is used to identify a first network slice instance in the first network slice, and the indication information is used to request to determine a second access and mobility management function network element that supports the type of the first network slice and the first network slice instance. A processing module <NUM> is configured to determine whether the second access and mobility management function network element exists in an area in which user equipment is located.

In this way, by using the network slicing-based communications apparatus in this embodiment of the present invention, before moving, the user equipment stores, in the data management function network element, information about the type of the first network slice serving the user equipment and about the first network slice instance. After the user equipment moves, the network slice selection function network element receives the information about the type of the first network slice and about the first network slice instance from the first access and mobility management function network element. The network slice selection function network element determines whether the access and mobility management function network element supporting the type of the first network slice and the first network slice instance exists in the area in which the user equipment is located, to select an appropriate access and mobility management function network element to serve the user equipment.

Optionally, the network slicing-based communications apparatus further includes a sending module <NUM>. When the second access and mobility management function network element exists in the area in which the user equipment is located, the sending module <NUM> is configured to send identification information of the second access and mobility management function network element to the first access and mobility management function network element.

Optionally, when the second access and mobility management function network element does not exist in the area in which the user equipment is located, the sending module <NUM> is configured to send identification information of a second network slice instance in the first network slice to the first access and mobility management function network element.

In addition, the receiving module <NUM>, the processing module <NUM>, and the sending module <NUM> in the network slicing-based communications apparatus may further implement other operations or functions of the network slice selection function network element in the foregoing method.

In another embodiment, the network slicing-based communications apparatus shown in <FIG> may be alternatively configured to perform operations of the third access and mobility management function network element (for example, the third AMF network element) in <FIG> and operations of the first access and mobility management function network element (for example, the first AMF network element) in <FIG>, and <FIG> and <FIG>. For example:.

A receiving module <NUM> is configured to obtain first information and second information. The first information is used to indicate a type of a first network slice, the second information is used to identify a first network slice instance in the first network slice, and the first access and mobility management function network element supports the type of the first network slice and the first network slice instance. A sending module <NUM> is configured to send the first information and the second information to user equipment or a data management function network element. The first information and the second information are used for determining a second access and mobility management function network element. The second access and mobility management function network element supports the type of the first network slice and the network slice instance. The first information and the second information are further used for determining a network slice instance that is in the first network slice and that serves the user equipment.

Therefore, by using the network slicing-based communications apparatus in this embodiment of the present invention, before the user equipment moves, the user equipment or a core network may learn of a network slice instance that serves the user equipment. After the user equipment moves, the core network selects the same network slice instance that serves the user equipment before the movement, to ensure that a session established before the user equipment moves is not interrupted, thereby improving user experience.

Optionally, that the sending module <NUM> sends the first information and the second information to the user equipment or the data management function network element includes: sending, by the sending module <NUM>, a registration accept message to the user equipment, where the registration accept message includes the first information and the second information; or sending, by the sending module <NUM>, a session establishment accept message to the user equipment, where the session establishment accept message includes the first information and the second information.

In addition, the receiving module <NUM> and the sending module <NUM> in the network slicing-based communications apparatus may further implement other operations or functions of the access and mobility management function network element in the foregoing method.

In another embodiment, the network slicing-based communications apparatus shown in <FIG> may be alternatively configured to perform operations of the network slice selection function network element (for example, the NSSF network element) in <FIG>. For example:.

A receiving module <NUM> is configured to receive first information and indication information from an access and mobility management function network element. The first information is used to indicate a type of a network slice, the indication information is used to request to determine a network slice instance that is in the network slice and that serves user equipment, and the access and mobility management function network element supports the type of the network slice and the network slice instance. A sending module <NUM> is configured to send second information to the access and mobility management function network element, where the second information is used to identify a network slice instance in the network slice.

Therefore, by using the network slicing-based communications apparatus in this embodiment of the present invention, when there is no access and mobility management function network element that supports a type of a first network slice and a first network slice instance in the network, a core network may select the network slice instance supported by the access and mobility management function network element to serve the user equipment.

In addition, the receiving module <NUM> and the sending module <NUM> in the network slicing-based communications apparatus may further implement other operations or functions of the network slice selection function network element in the foregoing method.

<FIG> is another possible schematic structural diagram of the network slicing-based communications apparatus/the user equipment in the foregoing embodiments. A network slicing-based communications apparatus/user equipment includes a transceiver <NUM> and a processor <NUM>, as shown in <FIG>. For example, the processor <NUM> may be a general-purpose microprocessor, a data processing circuit, an application-specific integrated circuit (application specific integrated circuit, ASIC), or a field-programmable gate array (field-programmable gate array, FPGA) circuit. The network slicing-based communications apparatus/the user equipment may further include a memory <NUM>. For example, the memory is a random access memory (random access memory, RAM). The memory is configured to couple to the processor <NUM>, and stores a computer program <NUM> necessary for the network slicing-based communications apparatus/the user equipment.

In addition, the network slicing-based communication method in the foregoing embodiments further provides a carrier <NUM>. The carrier stores a computer program <NUM> of the network slicing-based communications apparatus/the user equipment, and the computer program <NUM> may be loaded into the processor <NUM>. The carrier may be an optical signal, an electrical signal, an electromagnetic signal, or a computer-readable storage medium (for example, a hard disk).

When the computer program <NUM> or <NUM> runs on a computer (for example, runs on the processor <NUM>), the computer may be enabled to perform the foregoing method.

For example, in an embodiment, the processor <NUM> is configured to implement another operation or function of a radio access network device. The transceiver <NUM> is configured to implement communication between a network slicing-based communications apparatus and user equipment/an access and mobility management function network element.

In another embodiment, the processor <NUM> is configured to implement another operation or function of an access and mobility management function network element. The transceiver <NUM> is configured to implement communication between a network slicing-based communications apparatus and a radio access network device/a network slice selection function network element/user equipment.

In another embodiment, the processor <NUM> is configured to implement another operation or function of user equipment. The transceiver <NUM> is configured to implement communication between the user equipment and a radio access network device/a second access and mobility management function network element/a third access and mobility management function network element/an interworking network element.

In another embodiment, the processor <NUM> is configured to perform another operation or function of a first access and mobility management function network element. The transceiver <NUM> is configured to implement communication between a network slicing-based communications apparatus and a data management function network element/a network slice selection function network element.

In another embodiment, the processor <NUM> is configured to implement another operation or function of a data management function network element. The transceiver <NUM> is configured to implement communication between a network slicing-based communications apparatus and a first access and mobility management function network element/a second access and mobility management function network element.

In another embodiment, the processor <NUM> is configured to implement another operation or function of a network slice selection function network element. The transceiver <NUM> is configured to implement communication between a network slicing-based communications apparatus and a first access and mobility management function network element.

The controller/processor configured to implement the foregoing radio access network device in this 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 another programmable logical device, a transistor logical device, a hardware component, or any combination thereof. The controller/processor may implement or execute various logical blocks, modules, and circuits in the examples described with reference to content disclosed in this application. Alternatively, the processor may be a combination of processors implementing a computing function, for example, a combination of one or more microprocessors, or a combination of a DSP and a microprocessor.

Method or algorithm steps described with reference to the content disclosed in this application may be implemented by hardware, or may be implemented by a processor by executing a software instruction. The software instruction may be formed by a corresponding software module. The software module may be stored in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable hard disk, a CD-ROM, or a storage medium of any other form known in the art. For example, a storage medium is coupled to a processor, so that the processor can read information from the storage medium or write information into the storage medium. Certainly, the storage medium may be a component of the processor. The processor and the storage medium may be located in an ASIC. In addition, the ASIC may be located in a radio access network device. Certainly, the processor and the storage medium may alternatively exist in the radio access network device as discrete modules.

Claim 1:
A network slicing-based communication method, comprising:
receiving (S302), by a radio access network device (<NUM>), a registration request from a user equipment (<NUM>), wherein the registration request comprises first information and second information, the first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice;
determining (<NUM>), by the radio access network device, a first access and mobility management function network element (<NUM>) based on the type of the first network slice and the first network slice instance;
sending (S304), by the radio access network device, the registration request to the access and mobility management function network element, wherein the first information and the second information are used for network slice instance determining
characterized by further comprising:
receiving (S501), by the radio access network device, capability information from another access and mobility management function network element, wherein the capability information is used to indicate a network slice type and a network slice instance that are supported by the other access and mobility management function network element; and
determining (S502), by the radio access network device, the other access and mobility management function network element based on the type of the first network slice, the first network slice instance, and the capability information;
wherein the determined access and mobility management function network element supports the type of the first network slice and the first network slice instance requested by the user equipment.