WO2021159523A1

WO2021159523A1 - Communication method, apparatus and system

Info

Publication number: WO2021159523A1
Application number: PCT/CN2020/075417
Authority: WO
Inventors: 朱方园; 孙海洋; 李岩
Original assignee: 华为技术有限公司
Priority date: 2020-02-14
Filing date: 2020-02-14
Publication date: 2021-08-19

Abstract

The present application provides a communication method, apparatus and system. The method comprises: after a first slice carries out slice authentication, a first mobility management network element determines an allowable NSSAI, the first slice being a slice requiring slice authentication in slices that a terminal device requests to access; and the first mobility management network element selects a policy control network element according to the allowable NSSAI. On the basis of the solution, before the slice authentication process is carried out, no policy control network element is selected, and after the slice authentication process is carried out, the mobility management network element selects the policy control network element according to NSSAI of the final terminal device, so as to avoid the problem of reselecting a policy control network element since the policy control network element selected before the slice authentication process does not support the slice after the slice authentication process. Furthermore, the problem of policy reselection can also be avoided, thereby saving resources.

Description

Communication method, device and system

Technical field

This application relates to the field of communication technology, and in particular to communication methods, devices and systems.

Background technique

In the registration process of the terminal device, if the mobility management network element decides to establish a policy association with the policy control network element, the mobility management network element will select the assistance information (network slice selection assistance information, NSSAI) according to the network slice requested by the terminal device. ) Determine the allowed NSSAI, where the requested NSSAI includes identification information of one or more network slices that the terminal device requests to access, and the allowed NSSAI includes identification information of one or more network slices that the terminal device is allowed to access. Then, the mobility management network element controls the network element according to the allowed NSSAI selection policy.

After the mobility management network element selects the policy control network element, it initiates a policy association establishment process to request the policy control network element to obtain the policy. At the same time, the policy control network element returns a policy control request trigger to the mobility management network element. Request Triggers). When the mobility management network element subsequently determines that the triggering condition of the policy control request trigger is satisfied, the mobility management network element needs to request the policy control network element to update the policy. Wherein, the trigger condition of the policy control request trigger includes: the allowed NSSAI of the terminal device is changed. That is, a change in the allowed NSSAI of the terminal device will trigger the mobility management network element to request the policy control network element to update the policy.

After the registration process, the network enters the slice authentication process of the network slice, that is, performs the slice authentication process on the network slices that need to perform slice authentication in the requested NSSAI. If the slice authentication of a certain network slice is successful, a new allowed NSSAI is obtained according to the identification information of the network slice. The new allowed NSSAI includes the allowed NSSAI determined in the registration process and the network that contains the successful slice authentication. The identification information of the slice.

Therefore, the new allowed NSSAI obtained after the slice authentication process may be different from the allowed NSSAI determined in the registration process, that is, the allowed NSSAI of the terminal device changes, which triggers the mobility management network element to change to the policy control network element Request an update policy.

However, the policy control network element selected in the registration process may not support the new allowed NSSAI, which leads to the need to reselect a policy control network element that supports the new allowed NSSAI, that is, trigger the reselection of the policy control network element, and thus Cause a waste of resources.

Summary of the invention

The present application provides a communication method, device, and system to reduce the reselection of policy control network elements, thereby saving resources.

In a first aspect, an embodiment of the present application provides a communication method, including: after the first slice performs slice authentication, the first mobility management network element determines the allowed network slice selection auxiliary information NSSAI, and the allowed NSSAI includes the allowed terminal The identification information of the slice accessed by the device, the first slice is the slice for which slice authentication needs to be performed among the slices that the terminal device requests to access; the first mobility management network element selects the policy control network element according to the allowed NSSAI; where, The slice corresponding to the NSSAI allowed by the first mobility management network element service.

Based on the above solution, before performing the slice authentication process, the policy control network element is not selected. After the slice authentication process is performed, the mobility management network element selects the policy control network element according to the final NSSAI of the terminal device, thereby avoiding the slice authentication process. The policy control network element selected before the right process does not support the slice after the slice authentication process, which leads to the problem of reselecting the policy control network element. Furthermore, the problem of reselection strategy can also be avoided, so that resources can be saved.

In a possible implementation method, the first mobility management network element obtains the first policy associated with the allowed NSSAI from the policy control network element.

In a possible implementation method, before the first slice performs slice authentication, the first mobility management network element receives the requested NSSAI from the terminal device in the registration process, and the requested NSSAI includes the terminal device requests to access the NSSAI. The identification information of the slice; the first mobility management network element determines that the first slice in the slice requested for access needs to perform slice authentication, and then determines that the policy control network element is not selected in the registration process.

In a possible implementation method, the first mobility management network element selects the policy control network element according to the allowed NSSAI, including: the first mobility management network element obtains the context of the terminal device from the second mobility management network element, The context of the terminal device does not include the information of the policy control network element. The second mobility management network element is the network element that receives the requested NSSAI from the terminal device during the registration process, and the requested NSSAI includes the slice that the terminal device requests to access. Identification information; the first mobility management network element selects a policy control network element according to the context of the terminal device and the allowed NSSAI.

In a possible implementation method, when the first slice performs slice authentication successfully, the allowed NSSAI includes the identification information of the first slice; or, when the first slice fails to perform slice authentication, the allowed NSSAI does not include Identification information of the first slice.

In a second aspect, an embodiment of the present application provides a communication method, including: a first mobility management network element determines a first NSSAI, the first NSSAI includes the first allowed NSSAI and the pending NSSAI, or the first NSSAI includes the terminal equipment For the signed NSSAI, the pending NSSAI includes the identification information of the slice that needs to perform slice authentication among the slices that the terminal device requests to access; the first mobility management network element selects the policy control network element according to the first NSSAI.

Based on the above solution, the first mobility management network element controls the network element according to the allowed NSSAI and the pending NSSAI selection strategy, or according to the NSSAI selection strategy contracted by the terminal device, so that even if the subsequent allowed NSSAI changes, The new allowed NSSAI is also determined from the allowed NSSAI and the pending NSSAI, or if it is determined from the NSSAI contracted by the terminal device, the policy control network element still supports the new allowed NSSAI, so that it does not The policy control network element needs to be reselected, that is, the reselection of the policy control network element will not be triggered. Therefore, resource expenditure can be saved.

In a possible implementation method, the first mobility management network element obtains the first policy associated with the first allowed NSSAI from the policy control network element.

In a possible implementation method, after slice authentication is performed on the slice corresponding to the pending NSSAI, the first mobility management network element determines the second allowed NSSAI, and the second allowed NSSAI includes the slice authentication performed in the pending NSSAI Identification information of the successful slice; the first mobility management network element obtains the second policy associated with the second allowed NSSAI from the policy control network element.

In a possible implementation method, if the first mobility management network element cannot serve the second allowed NSSAI, the first mobility management network element sends the second policy to the terminal device.

In a possible implementation method, after slice authentication is performed on the slice corresponding to the pending NSSAI, the first mobility management network element determines the second allowed NSSAI, and the second allowed NSSAI includes the slice authentication performed in the pending NSSAI The identification information of the successful slice; if the first mobility management network element cannot serve the second allowed NSSAI, the first mobility management network element sets the first indication information in the context of the terminal device, and the first indication information is used to indicate the second 2. The mobility management network element obtains the policy from the policy control network element.

In a third aspect, an embodiment of the present application provides a communication method, including: a second mobility management network element obtains a context of a terminal device from a first mobility management network element, and the context of the terminal device includes identification information of the policy control network element and The first indication information; the second mobility management network element determines the allowed NSSAI; the second mobility management network element obtains the policy associated with the allowed NSSAI from the policy control network element according to the first indication information.

In a possible implementation method, the first indication information is used to instruct the second mobility management network element to obtain the policy from the policy control network element.

In a fourth aspect, an embodiment of the present application provides a communication method, including: after the first slice performs slice authentication, the first mobility management network element determines the allowed NSSAI, and the allowed NSSAI includes the slice that allows the terminal device to access The first slice is the slice for which slice authentication needs to be performed among the slices that the terminal device requests to access; the first mobility management network element obtains the first policy associated with the allowed NSSAI from the policy control network element; first The mobility management network element stores the first strategy and indication information in the context of the terminal device, and the indication information is used to instruct the second mobility management network element to send the first strategy to the terminal device.

Based on the above solution, in a scenario where the mobility management network element changes, the old mobility management network element obtains the new policy from the policy control network element and stores it in the context of the terminal device, and then the new mobility management network The element obtains the new strategy from the context of the terminal device and sends it to the terminal device, thereby solving the problem of how to trigger the new mobility management network element to send the updated strategy to the terminal device in a scenario where the mobility management network element changes. .

In a fifth aspect, an embodiment of the present application provides a communication method, including: after the first slice performs slice authentication, the first mobility management network element determines the allowed NSSAI, and the allowed NSSAI includes the slice that allows the terminal device to access The first slice is the slice for which slice authentication needs to be performed among the slices that the terminal device requests to access; if the first mobility management network element cannot serve the allowed NSSAI, the first mobility management network element is in the terminal device’s The identification information of the policy control network element and the first indication information are set in the context, and the first indication information is used to instruct the second mobility management network element to obtain the policy from the policy control network element. ; The first mobility management network element sends the allowed NSSAI and second indication information to the terminal device, the second indication information is used to instruct the terminal device to register with the second mobility management network element according to the allowed NSSAI.

Based on the above solution, in a scenario where the mobility management network element changes, the old mobility management network element selects the strategy control network element and sets the identification information and an indication information of the strategy control network element in the context of the terminal device, and then The new mobility management network element obtains the identification information of the policy control network element from the context of the terminal device, and triggers the new mobility management network element to obtain a new policy from the policy control network element according to the first indication information, thereby solving In the scenario where the mobility management network element changes, how to trigger the new mobility management network element to send an updated strategy to the terminal device.

In a sixth aspect, an embodiment of the present application provides a communication device, which may be a mobility management network element, or a chip used for a mobility management network element. The device has the function of realizing any of the first aspect to the fifth aspect, or any embodiment of the first aspect or the fifth aspect. This function can be realized by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

In a seventh aspect, an embodiment of the present application provides a communication device including a processor and a memory; the memory is used to store computer-executable instructions, and when the device is running, the processor executes the computer-executable instructions stored in the memory to enable The device executes the method of any one of the above-mentioned first aspect to the fifth aspect, or any embodiment of the first aspect or the fifth aspect.

In an eighth aspect, an embodiment of the present application provides a communication device, including a unit or means for performing any of the above-mentioned first aspect to the fifth aspect, or each step of any embodiment of the first aspect or the fifth aspect (means).

In a ninth aspect, an embodiment of the present application provides a communication device, including a processor and an interface circuit, the processor is configured to communicate with other devices through the interface circuit, and execute any of the first to fifth aspects, or The method of any embodiment of the first or fifth aspect. The processor includes one or more.

In a tenth aspect, an embodiment of the present application provides a communication device, including a processor, configured to be connected to a memory, and configured to call a program stored in the memory to execute any of the above-mentioned first to fifth aspects, Or the method of any embodiment of the first or fifth aspect. The memory can be located inside the device or outside the device. And the processor includes one or more.

In an eleventh aspect, an embodiment of the present application also provides a computer-readable storage medium having instructions stored in the computer-readable storage medium, which when run on a computer, cause a processor to execute the above-mentioned first to fifth aspects. The method described in any of the aspects, or any embodiment of the first or fifth aspect.

In the twelfth aspect, the embodiments of the present application also provide a computer program product. The computer product includes a computer program. The method described in any embodiment of the five aspects is executed.

In a thirteenth aspect, an embodiment of the present application also provides a chip system, including a processor, configured to execute any aspect of the first aspect to the fifth aspect, or any of the first aspect or the fifth aspect of the embodiment. The method described.

In a fourteenth aspect, an embodiment of the present application also provides a communication system, including: a mobility management network element and a policy control network element. The mobility management network element is configured to determine the allowed network slice selection auxiliary information NSSAI after the first slice performs slice authentication, and the allowed NSSAI includes identification information of the slice that is allowed to be accessed by the terminal device. The first slice is the slice for which slice authentication needs to be performed among the slices that the terminal device requests to access; select the policy control network element according to the allowed NSSAI; and, obtain the data from the policy control network element. The first policy associated with the allowed NSSAI; wherein the mobility management network element serves the slice corresponding to the allowed NSSAI. The policy control network element is used to send the first policy to the mobility management network element.

In a fifteenth aspect, an embodiment of the present application also provides a communication system, including: a first mobility management network element and a policy control network element. The first mobility management network element is used to determine a first NSSAI, where the first NSSAI includes a first allowed NSSAI and a pending NSSAI, or the first NSSAI includes a contracted NSSAI of a terminal device, and the pending NSSAI The NSSAI includes the identification information of the slice that needs to perform slice authentication among the slices that the terminal device requests to access; selects the policy control network element according to the first NSSAI; and, obtains it from the policy control network element The first policy associated with the first allowed NSSAI. The policy control network element is configured to send the first policy to the first mobility management network element.

Description of the drawings

Figure 1A is a schematic diagram of a 5G network architecture based on a service-oriented architecture;

Figure 1B is a schematic diagram of a 5G network architecture based on a point-to-point interface;

Figure 2 is a schematic diagram of the NSSAA process in the prior art;

FIG. 3A is a schematic flowchart of a communication method provided by this application;

FIG. 3B is a schematic flowchart of another communication method provided by this application;

FIG. 3C is a schematic flowchart of another communication method provided by this application;

FIG. 3D is a schematic flowchart of another communication method provided by this application;

FIG. 4 is a schematic flow diagram of another communication method provided by this application;

FIG. 5 is a schematic flowchart of another communication method provided by this application;

FIG. 6 is a schematic flowchart of another communication method provided by this application;

FIG. 7 is a schematic flowchart of another communication method provided by this application;

FIG. 8 is a schematic flowchart of another communication method provided by this application;

FIG. 9 is a schematic flowchart of another communication method provided by this application;

FIG. 10 is a schematic diagram of a communication device provided by this application;

FIG. 11 is a schematic diagram of a mobility management network element provided by this application.

Detailed ways

In order to make the purpose, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The specific operation method in the method embodiment can also be applied to the device embodiment or the system embodiment.

As shown in Figure 1A, it is a schematic diagram of a fifth generation (5G) network architecture based on a service-oriented architecture. The 5G network architecture shown in FIG. 1A may include three parts, namely a terminal equipment part, a data network (DN), and an operator network part. The functions of some of the network elements are briefly introduced below.

Among them, the operator network may include one or more of the following network elements: Authentication Server Function (AUSF) network elements, network exposure function (NEF) network elements, policy control function (policy control) function, PCF) network element, unified data management (UDM) network element, unified database (Unified Data Repository, UDR), network storage function (Network Repository Function, NRF) network element, application function (AF) ) Network element, access and mobility management function (AMF) network element, session management function (SMF) network element, radio access network (RAN) and user plane function (user plane function, UPF) network element, network slice selection function (Network Slice Selection Function, NSSF) network element (not shown in the figure), etc. In the above-mentioned operator's network, the part other than the radio access network part may be referred to as the core network part.

Terminal device (terminal device) is a device with wireless transceiver function. It can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; it can also be deployed on the water (such as ships, etc.); it can also be deployed in the air ( For example, airplanes, balloons, satellites, etc.). The terminal device may be a mobile phone (mobile phone), a tablet computer (pad), a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, an industrial control (industrial control) Wireless terminals in ), wireless terminals in self-driving, wireless terminals in remote medical, wireless terminals in smart grid, and wireless terminals in transportation safety , Wireless terminals in smart cities, wireless terminals in smart homes, user equipment (UE), etc.

The above-mentioned terminal device may establish a connection with the operator's network through an interface (such as N1, etc.) provided by the operator's network, and use services such as data and/or voice provided by the operator's network. The terminal device can also access the DN through the operator's network, and use the operator's service deployed on the DN and/or the service provided by a third party. Among them, the above-mentioned third party may be a service party other than the operator's network and terminal equipment, and may provide other services such as data and/or voice for the terminal equipment. Among them, the specific form of expression of the above-mentioned third party can be determined according to actual application scenarios, and is not limited here.

RAN is a sub-network of an operator's network, and an implementation system between service nodes and terminal equipment in the operator's network. To access the operator's network, the terminal device first passes through the RAN, and then can be connected to the service node of the operator's network through the RAN. RAN equipment is a type of equipment that provides wireless communication functions for terminal equipment. RAN equipment is also called access network equipment. RAN equipment includes but is not limited to: next-generation base stations (gnodeB, gNB) in 5G, evolved node B (evolved node B, eNB), radio network controller (RNC), node B (node B, NB), base station controller (BSC), base transceiver station (BTS), home base station (for example, home evolved nodeB, or home node B, HNB), baseband unit (BBU) , Transmission point (transmitting and receiving point, TRP), transmitting point (transmitting point, TP), mobile switching center, etc.

The AMF network element mainly performs functions such as mobility management and access authentication/authorization. In addition, it is also responsible for transferring user policies between UE and PCF.

The SMF network element mainly performs functions such as session management, execution of control policies issued by PCF, selection of UPF, and UE Internet Protocol (IP) address allocation.

The UPF network element, as the interface UPF with the data network, completes functions such as user plane data forwarding, session/stream-based billing statistics, and bandwidth limitation.

The UDM network element is mainly responsible for functions such as management of contract data and user access authorization.

UDR is mainly responsible for the access function of contract data, strategy data, application data and other types of data.

NEF network elements are mainly used to support the opening of capabilities and events.

The AF network element mainly conveys the requirements of the application side to the network side, for example, quality of service (QoS) requirements or user status event subscriptions. The AF can be a third-party functional entity, or an application service deployed by an operator, such as an IP Multimedia Subsystem (IMS) voice call service.

The PCF network element is mainly responsible for policy control functions such as billing, QoS bandwidth guarantee and mobility management, and UE policy decision-making for the session and service flow levels. In this architecture, the PCF connected to the AMF and the SMF corresponds to AM PCF (PCF for Access and Mobility Control) and SM PCF (PCF for Session Management) respectively, and may not be the same PCF entity in actual deployment scenarios.

The NRF network element can be used to provide the network element discovery function, and provide the network element information corresponding to the network element type based on the request of other network elements. NRF also provides network element management services, such as network element registration, update, de-registration, and network element status subscription and push.

AUSF network element: Mainly responsible for authenticating users to determine whether users or devices are allowed to access the network.

NSSF network elements are mainly used to select network slices and count users in the network slices.

A DN is a network located outside the operator's network. The operator's network can access multiple DNs. A variety of services can be deployed on the DN to provide terminal equipment with services such as data and/or voice. For example, DN is the private network of a smart factory. The sensors installed in the workshop of the smart factory can be terminal devices. A control server for the sensors is deployed in the DN, and the control server can provide services for the sensors. The sensor can communicate with the control server, obtain instructions from the control server, and transmit the collected sensor data to the control server according to the instructions. For another example, the DN is the internal office network of a company. The mobile phones or computers of the employees of the company can be terminal devices, and the mobile phones or computers of the employees can access the information and data resources on the internal office network of the company.

In Figure 1A, Nausf, Nnef, Npcf, Nudm, Naf, Namf, Nsmf, N1, N2, N3, N4, and N6 are interface serial numbers. The meaning of these interface serial numbers can be referred to the meaning defined in the 3rd generation partnership project (3rd generation partnership project, 3GPP) standard protocol, which is not limited here.

As shown in FIG. 1B, it is a schematic diagram of a 5G network architecture based on a point-to-point interface. For the introduction of the functions of the network elements therein, reference may be made to the introduction of the functions of the corresponding network elements in FIG. 1A, which will not be repeated. The main difference between Fig. 1B and Fig. 1A is that the interfaces between the various network elements in Fig. 1B are point-to-point interfaces, rather than service-oriented interfaces.

In the architecture shown in Figure 1B, the interface names and functions between each network element are as follows:

1) N7: The interface between PCF and SMF, which can be used to issue protocol data unit (protocol data unit, PDU) session granularity and service data flow granularity control strategy.

2) N15: The interface between PCF and AMF, which can be used to issue UE policies and access control related policies.

3) N5: The interface between AF and PCF, which can be used for application service request issuance and network event reporting.

4), N4: The interface between SMF and UPF, which can be used to transfer information between the control plane and the user plane, including controlling the issuance of user-oriented forwarding rules, QoS control rules, traffic statistics rules, etc., and user-plane Information reported.

5) N11: The interface between SMF and AMF, which can be used to transfer PDU session tunnel information between RAN and UPF, transfer control messages sent to UE, and transfer radio resource control information sent to RAN.

6) N2: The interface between AMF and RAN, which can be used to transfer radio bearer control information from the core network side to the RAN.

7) N1: The interface between the AMF and the UE, which can be used to transfer QoS control rules to the UE.

8) N8: The interface between AMF and UDM, which can be used for AMF to obtain access and mobility management related subscription data and authentication data from UDM, and AMF to register UE current mobility management related information with UDM, etc.

9) N10: The interface between SMF and UDM, which can be used for SMF to obtain session management related subscription data from UDM, and SMF to register UE current session related information with UDM, etc.

10) N35: The interface between UDM and UDR, which can be used for UDM to obtain user subscription data information from UDR.

11) N36: The interface between the PCF and the UDR, which can be used for the PCF to obtain policy-related contract data and application data-related information from the UDR.

12) N12: The interface between AMF and AUSF, which can be used for AMF to initiate an authentication process to AUSF, where SUCI can be carried as a contract identifier;

13). N13: The interface between UDM and AUSF, which can be used for AUSF to obtain user authentication vector from UDM to execute the authentication process.

It is understandable that the aforementioned network elements or functions may be network elements in hardware devices, software functions running on dedicated hardware, or virtualization functions instantiated on a platform (for example, a cloud platform). Optionally, the foregoing network element or function may be implemented by one device, or jointly implemented by multiple devices, or may be a functional module in one device, which is not specifically limited in the embodiment of the present application.

The mobility management network elements, session management network elements, policy control network elements, application function network elements, access network equipment, network opening function network elements, user plane network elements, and network slice selection network elements in this application can be respectively shown in the figure. The AMF, SMF, PCF, AF, RAN, NEF, UPF, NSSF in 1A or Figure 1B can also be future communications such as the 6th generation (6G) network with the above AMF, SMF, PCF, AF, RAN , NEF, UPF, and NSSF function network elements, this application is not limited to this. For the convenience of explanation, this application uses mobility management network elements, session management network elements, policy control network elements, application function network elements, access network equipment, network open function network elements, user plane network elements, and network slice selection network elements respectively. Take the above AMF, SMF, PCF, AF, RAN, NEF, UPF, and NSSF as examples. Further, in this application, the terminal device is a UE as an example for description.

In the 5G era, hundreds of billions of IoT devices will be connected to the network. Different types of application scenarios have different network requirements, and some even conflict with each other. Simultaneously providing services for different types of application scenarios through a single network will result in extremely complex network architecture and low network management efficiency and resource utilization efficiency. 5G network slicing technology provides isolated network environments for different application scenarios by virtual independent logical networks on the same network infrastructure, so that different application scenarios can customize network functions and features according to their own needs, and can effectively guarantee the performance of different services. QoS requirements. The goal of 5G network slicing is to organically combine terminal equipment, access network resources, core network resources, and network operation and maintenance and management systems, so as to provide independent operation and maintenance for different business scenarios or types of services. The internet.

A variety of scenarios put forward different needs for the 3GPP ecosystem: billing, policy, security, mobility, etc. 3GPP emphasizes that there is no mutual influence between network slices, for example, a large number of sudden meter reading services should not affect normal mobile broadband services. In order to meet the diverse needs and isolation between slices, relatively independent management and operation and maintenance between businesses are required, and tailor-made business functions and analysis capabilities are provided. Instances of different types of services are deployed on different network slices, and different instances of the same service type can also be deployed on different network slices.

When a network slice is deployed in the core network, if a user initially attaches to the network, the selection process of the network slice will be triggered. The selection process of the network slice depends on the user's subscription data, local configuration information, roaming agreement, operator's strategy, and so on. In the selection process of the network slice, the above parameters need to be considered comprehensively to select the best slice type for the UE.

When the UE needs to access a certain network slice, the UE may provide a requested (Requested) NSSAI to the core network for the core network to select a network slice instance for the UE.

In a 5G network, when a UE needs to use network services, it first needs to register with the network. The registration process is divided into the following scenarios:

1) Register to the 5G network for the first time.

2) When the UE moves out of the originally registered area, the mobility registration update is performed.

3) Periodic registration updates.

The registration process may trigger the establishment of one or more PDU sessions. For example, in the scenario of mobility registration update, the UE has uplink data to send. At this time, the PDU session will be created during the registration process.

When the UE is registered in the network, in addition to performing the primary authentication process of the permanent identity of the UE (also known as the one-time authentication process), the network may also determine whether it needs to perform the network based on the NSSAI requested by the UE and the subscription data of the UE. A slice-specific authentication and authorization (Network Slice Specific Authentication and Authorization, NSSAA) process, which may also be referred to as a secondary authentication process or a network slice secondary authentication process.

As shown in Figure 2, it is a schematic diagram of the NSSAA process. The process includes the following steps:

In step 201, the UE initiates a registration process and sends a Registration Request (Registration Request) message to the AMF. The Registration Request message carries the requested NSSAI (Requested NSSAI).

In step 202, the AMF executes the main authentication procedure of the permanent identity of the UE. After the procedure is successful, the AMF obtains the UE's subscription data from the UDM. The subscription data includes the S-NSSAI subscribed by the UE and indication information corresponding to each S-NSSAI, and the indication information is used to indicate whether the S-NSSAI needs to perform NSSAA. Among them, the contracted S-NSSAI refers to the slice type (HPLMN S-NSSAI) of the home domain network where the UE is located.

For example, the S-NSSAI and indication information of the subscription in the subscription data of the UE are shown in Table 1.

Table 1

签约的S-NSSAISigned S-NSSAI	指示信息：该S-NSSAI是否需要执行NSSAAInstruction information: whether the S-NSSAI needs to execute NSSAA
S-NSSAI-1S-NSSAI-1	是Yes
S-NSSAI-2S-NSSAI-2	否no
S-NSSAI-3S-NSSAI-3	否no

In step 203, the AMF determines whether the NSSAA process needs to be executed.

It should be noted that in the present invention, the AMF determines that the S-NSSAI in the requested NSSAI needs to execute NSSAA can have two meanings:

The first type: a certain S-NSSAI in the requested NSSAI belongs to the contracted S-NSSAI, and the contracted S-NSSAI needs to execute NSSAA, then the AMF determines that the S-NSSAI in the requested NSSAI needs to execute NSSAA.

Specifically, the AMF determines whether the S-NSSAI that needs to perform the NSSAA process is included in the Requested NSSAI according to the UE's subscription data. If it is included, the AMF determines that the UE needs to perform the NSSAA process after this registration process. That is, it can be understood that the requested NSSAI includes the slice type (HPLMN S-NSSAI) of the home domain network.

Example 1: For example, the Requested NSSAI carried by the UE is S-NSSAI-1 and S-NSSAI-2, where S-NSSAI-1 needs to execute the NSSAA process, and S-NSSAI-2 does not need to execute the NSSAA process.

The second type: a certain S-NSSAI in the requested NSSAI can be mapped to a contracted S-NSSAI, and the contracted S-NSSAI needs to execute NSSAA, then the AMF determines that the S-NSSAI in the requested NSSAI needs to execute NSSAA.

Specifically, according to the UE’s subscription data, AMF determines that a certain S-NSSAI included in the Requested NSSAI can be mapped to HPLMN S-NSSAI, and the HPLMN S-NSSAI needs to perform the NSSAA process, then the AMF determines that the UE is after this registration process The NSSAA process needs to be performed.

Example 2: For example, the Requested NSSAI carried by the UE is S-NSSAI-A and S-NSSAI-B, where S-NSSAI-A is mapped to S-NSSAI-1, and S-NSSAI-B is mapped to S-NSSAI-2, and S-NSSAI-1 needs to execute the NSSAA process, and S-NSSAI-2 does not need to execute the NSSAA process. Then the AMF determines that the UE needs to perform the NSSAA procedure on the S-NSSAI-1 after this registration procedure.

Step 204: The Registration Accept message sent by the AMF to the UE carries the allowed NSSAI (Allowed NSSAI), the pending NSSAI (Pending NSSAI), and the pending reason value.

Among them, Allowed NSSAI only includes S-NSSAI that does not require NSSAA, Pending NSSAI includes S-NSSAI that requires NSSAA, and the pending reason value is waiting for NSSAA. The cause value is used to indicate to the UE that those S-NSSAIs that require NSSAA are in a pending state.

For example 1 in the previous example, Allowed NSSAI=S-NSSAI-2, Pending NSSAI=S-NSSAI-1, the reason value to be determined: waiting for NSSAA. For example 2 in the previous example, Allowed NSSAI=S-NSSAI-B, Pending NSSAI=S-NSSAI-A, reason value: waiting for NSSAA.

It should be noted that Pending NSSAI can also be called pending NSSAI. The embodiment of the present application takes Pending NSSAI referred to as pending NSSAI as an example for description.

Step 205: After the registration acceptance message is sent, the AMF executes the NSSAA procedure for the pending S-NSSAI.

It should be noted that, in the present invention, AMF can have two meanings for executing NSSAA on the S-NSSAI in the pending NSSAI:

The first type: a certain S-NSSAI in the pending NSSAI belongs to the contracted S-NSSAI, and the contracted S-NSSAI needs to perform NSSAA, then the AMF performs NSSAA on the S-NSSAI.

For example, following the example 1 in the above example, Pending NSSAI=S-NSSAI-1, since S-NSSAI-1 is HPLMN S-NSSAI, AMF performs the NSSAA process on S-NSSAI-1.

The second type: a certain S-NSSAI in the pending NSSAI is mapped to the contracted S-NSSAI, and the contracted S-NSSAI needs to perform NSSAA, then the AMF performs NSSAA for the contracted S-NSSAI.

Following example 2 in the above example, Pending NSSAI=S-NSSAI-A, since S-NSSAI-A is mapped to S-NSSAI-1, AMF performs the NSSAA process on S-NSSAI-1.

This step 205 is an optional step. When there is an S-NSSAI that needs to execute the NSSAA process, step 205 is executed. Otherwise, step 205 is not executed.

It should be noted that if there are multiple S-NSSAIs that need to execute the NSSAA process, step 205 can be executed multiple times.

Step 206: After the execution of the NSSAA process is completed, the AMF determines whether the Allowed NSSAI of the UE needs to be updated according to the result of the process, and if necessary, sends a new Allowed NSSAI (new Allowed NSSAI) to the UE in the configuration update process.

If the NSSAA process is executed successfully, the S-NSSAI will be added to the Allowed NSSAI in step 204 to generate a new Allowed NSSAI. If the execution of the NSSAA procedure fails, the AMF does not need to update the Allowed NSSAI of the UE.

For example 1 in the previous example, if the NSSAA of S-NSSAI-1 is successfully executed, AMF sends new Allowed NSSAI to the UE, where new Allowed NSSAI includes S-NSSAI-1 and S-NSSAI-2. If the authentication fails, AMF will not update the Allowed NSSAI to the UE. For example 2 in the previous example, if the NSSAA of S-NSSAI-1 is executed successfully, AMF sends new Allowed NSSAI to the UE, where new Allowed NSSAI includes S-NSSAI-A and S-NSSAI-B, if authentication fails, AMF will not update the Allowed NSSAI to the UE.

This step 206 is an optional step. When the above step 205 is performed and the Allowed NSSAI of the UE needs to be updated, step 206 is performed.

Through the above-mentioned embodiments, after the UE registration procedure, if necessary, the NSSAA procedure can be performed on the S-NSSAI, and the Allowed NSSAI of the UE can be updated.

When the UE initiates the registration process to access the 5G network, the AMF and SMF initiate the PCF discovery and selection process respectively. After the PCF is selected, it initiates access and mobility (Access and Mobility, AM) policy association establishment and session management (Session Management) , SM) policy association establishment process, obtain corresponding policies (including Policy and Charging Control (PCC) rules) and policy event reporting triggers (also known as policy control request triggers (Policy Control Request Triggers)) , And deploy execution strategies. After receiving the SM policy, the SMF performs QoS mapping and sends the corresponding QoS information to the UPF, RAN and UE, thereby performing end-to-end QoS control. When the UE uses the service, when the corresponding trigger conditions are met (such as the UE subscription information changes or the UE access location changes), the PCF or AMF can initiate the AM policy association update process, and the PCF or SMF can initiate the SM policy association update Process to update the corresponding strategy. When the PCF detects that the UE's subscription information is deleted, the UE is registered from the network, or other corresponding trigger conditions are met, the PCF or AMF can initiate the AM policy association release process, and the PCF or SMF can initiate the SM policy association release process.

In the prior art, in the registration process of the UE, if the AMF decides to establish a policy association with the PCF, for example, when the AMF has not obtained the AM policy of the UE or the AMF does not have a legal AM policy, the AMF will select the PCF. If the AMF obtains the PCF ID (PCF ID) from the old AMF, it can directly locate the PCF. If the PCF ID cannot be located or the PCF ID is not obtained, the AMF will select a new PCF. In this process, the parameters used by the AMF to select the PCF include the subscription permanent identifier (SUPI), allowed NSSAI (Allowed NSSAI), and so on.

After the AMF selects the PCF, it initiates the AM policy association establishment process to request the PCF to obtain the AM policy. At the same time, the PCF returns the Policy Control Request Triggers to the AMF. When the AMF subsequently determines that the Policy Control Request Triggers is satisfied , Need to request the PCF to refresh the AM policy. Among them, the trigger events included in Policy Control Request Triggers include but are not limited to the following: the tracking area of the UE changes, the UE enters/leaves the presence reporting area (PRA), and the UE's allowed NSSAI (Allowed NSSAI) When the change occurs, the public land mobile network (PLMN) of the UE changes.

It should be noted here that according to Policy Control Request Triggers, when the Allowed NSSAI of the UE changes, and the AMF determines that it needs to obtain a new AM policy from the PCF, the AMF initiates the AM policy association update process to update the corresponding policy.

Combined with the process of AMF selecting PCF, the process shown in Figure 2 above has the following problems:

Question 1. During the registration process, if the AMF determines that it needs to perform the NSSAA process on some S-NSSAI in the Requested NSSAI, according to the prior art, the AMF needs to select the PCF and obtain the AM policy based on the Allowed NSSAI of the UE before the NSSAA process. However, in the registration process, because some S-NSSAIs need to perform the NSSAA process, the Allowed NSSAI of the UE at this time is temporary, not the final Allowed NSSAI. If the AMF selects the PCF according to the temporary Allowed NSSAI of the UE during the registration process , It is very likely that when the NSSAA process is successfully completed (the UE’s Allowed NSSAI is refreshed and new Allowed NSSAI is obtained), the PCF previously selected in the NSSAA process does not support the new Allowed NSSAI, it will cause the PCF to be reselected. Or it can be understood that AMF selected a PCF during the registration process. After the NSSAA process ends, AMF needs to reselect a PCF according to new Allowed NSSAI, that is, PCF reselection occurs.

Question 2: After the NSSAA process ends, if the Allowed NSSAI is refreshed, the AMF needs to update the AM policy to the PCF based on the new Allowed NSSAI, which results in frequent refresh of the policy.

Question 3: After the NSSAA process ends, if the current service AMF does not support new Allowed NSSAI, AMF relocation (AMF reselection) is required, but new AMF does not know that it is due to the AMF relocation caused by the UE's Allowed NSSAI update, then , How does new AMF know that it needs to obtain new policy for new Allowed NSSAI for UE?

In order to solve the above-mentioned problems, the present application is described with reference to the embodiments shown in FIGS. 3A to 3C and FIGS. 4 to 9.

In the following embodiments, the schemes adopted in the embodiments corresponding to Figs. 3A, 4, and 5 are summarized as follows: AMF does not select PCF before the NSSAA process, and after the NSSAA process ends, AMF according to the UE’s final Allowed NSSAI (ie new Allowed NSSAI) ) Select a suitable PCF and obtain policy information, so that the problems of PCF reselection and frequent refresh of the policy can be avoided. That is, the embodiments corresponding to FIG. 3A, FIG. 4, and FIG. 5 can solve the above-mentioned problem 1 and problem 2. Further, the embodiment corresponding to FIG. 3A is an overview of the solution, including a scene where the AMF does not change and a scene where the AMF changes. The embodiments corresponding to FIG. 4 and FIG. 5 are specific examples. The embodiment corresponding to FIG. 4 is applicable to a scenario where AMF does not change, that is, AMF supports both Allowed NSSAI and new Allowed NSSAI. The embodiment corresponding to FIG. 5 is applicable to a scenario where AMF changes, that is, old AMF supports Allowed NSSAI but does not support new Allowed NSSAI, and new AMF supports new Allowed NSSAI.

In the following embodiments, the solutions adopted in the embodiments corresponding to Figures 3B, 6 and 7 are summarized as follows: Use Allowed NSSAI and Pending NSSAI to select PCF, or use contracted NSSAI to select PCF, so if NSSAA succeeds, the Allowed NSSAI is updated to new Allowed NSSAI, the PCF also supports new Allowed NSSAI, so that PCF reselection can be avoided. That is, the embodiments corresponding to FIG. 3B, FIG. 6 and FIG. 7 can solve the above-mentioned problem 1. Further, the embodiment corresponding to FIG. 3B is an overview of the solution, including a scene where the AMF does not change and a scene where the AMF changes. The embodiments corresponding to FIG. 6 and FIG. 7 are specific examples. The embodiment corresponding to FIG. 6 is applicable to a scenario where AMF does not change, that is, AMF supports both Allowed NSSAI and new Allowed NSSAI. The embodiment corresponding to FIG. 7 is applicable to a scenario where AMF changes, that is, old AMF supports Allowed NSSAI but does not support new Allowed NSSAI, and new AMF supports new Allowed NSSAI.

In the following embodiments, the solutions adopted in the embodiments corresponding to FIG. 3C and FIG. 8 are summarized as follows: the PCF is still selected according to the method of the prior art, that is, the Allowed NSSAI is used to select the PCF before the NSSAA process, and the target scenario is: the PCF It also supports the new Allowed NSSAI obtained after the NSSAA process, that is, the PCF does not change and the AMF changes, that is, old AMF supports Allowed NSSAI, but does not support new Allowed NSSAI, and new AMF supports new Allowed NSSAI. In addition, the old AMF obtains the AM policy from the PCF according to the Allowed NSSAI during the registration process and sends it to the UE, and the old AMF obtains the updated AM policy from the PCF according to the new Allowed NSSAI after the NSSAA process and stores it in the context of the UE. Therefore, when the new AMF obtains the UE context from the old AMF, it can obtain the updated AM policy by the way, and the new AMF sends the updated AM policy to the UE. Among them, the embodiment corresponding to FIG. 3C is an overview of the solution, and the embodiment corresponding to FIG. 8 is a specific example. Therefore, the embodiment corresponding to FIG. 3C and FIG. 8 can solve the above-mentioned problem 3.

In the following embodiments, the solutions adopted in the embodiments corresponding to FIG. 3D and FIG. 9 are summarized as follows: PCF is still selected according to the method of the prior art, that is, Allowed NSSAI is used to select PCF before the NSSAA process, and the target scenario is: the PCF It also supports the new Allowed NSSAI obtained after the NSSAA process, that is, the PCF does not change and the AMF changes, that is, old AMF supports Allowed NSSAI, but does not support new Allowed NSSAI, and new AMF supports new Allowed NSSAI. In addition, the old AMF obtains the AM policy from the PCF according to the Allowed NSSAI during the registration process and sends it to the UE, and the old AMF generates an indication message according to the new Allowed NSSAI after the NSSAA process and stores the indication information in the context of the UE. , The indication information is used to trigger the new AMF to obtain the updated AM policy from the PCF, so when the new AMF obtains the UE context from the old AMF, it can obtain the updated AM policy from the PCF according to the indication information in the UE context, and the new The AMF sends the updated AM policy to the UE. Among them, the embodiment corresponding to Fig. 3D is an overview of the solution, and the embodiment corresponding to Fig. 9 is a specific example. Therefore, the embodiment corresponding to FIG. 3D and FIG. 8 can solve the above-mentioned problem 3.

It should be noted that the Allowed NSSAI in the embodiments of this application refers to the set of slices that the AMF determines to allow UE access before the NSSAA process, and the new Allowed NSSAI refers to the slices that the AMF determines to allow UE access after the NSSAA process. Collection, unified description here.

It should be noted that, in the embodiment of the present application, the network slice may also be referred to as a slice, and the two have the same meaning. Performing NSSAA on the S-NSSAI means performing NSSAA on the network slice corresponding to the S-NSSAI. Here is a unified description, and will not be repeated in the follow-up.

Based on the network architecture shown in FIG. 1A or FIG. 1B, as shown in FIG. 3A, the present application provides a communication method. The method includes the following steps:

Step 301a: After the slice authentication is performed on the first slice, the first AMF determines the allowed NSSAI. The allowed NSSAI includes the identification information of the slice that the UE is allowed to access. The first slice is the slice that the UE requests to access. Slice for slice authentication.

The first slice here refers to the slice that needs to perform slice authentication in the requested NSSAI sent by the UE. The first slice may be one or more slices.

Wherein, the allowed NSSAI includes the identification information of the slice in the requested NSSAI after the slice authentication is successfully performed. For example, when the first slice performs slice authentication successfully, the allowed NSSAI includes the identification information of the first slice. When the first slice fails to perform slice authentication, the allowed NSSAI does not include the identification information of the first slice.

For example, the allowed NSSAI here may refer to the aforementioned new Allowed NSSAI. Therefore, if the first slice performs slice authentication successfully, the first AMF may add the identification information of the first slice to the previously determined allowed NSSAI to obtain the new allowed NSSAI.

Optionally, the allowed NSSAI also contains the identification information of the slices in the requested NSSAI that do not need to perform slice authentication.

It should be noted that in the scenario where the AMF changes, the first AMF here refers to the changed AMF, that is, the new AMF. The slice corresponding to the NSSAI allowed by the first AMF service.

Before the slice authentication is performed on the first slice, no PCF is selected for the UE in the registration procedure of the UE.

Step 302a, the first AMF selects a PCF based on the allowed NSSAI.

It can be seen that the operation of the first AMF to select the PCF is performed after the first slice performs slice authentication.

Optionally, after step 302a, the following steps may be further included:

Step 303a, the first AMF obtains the first policy associated with the allowed NSSAI from the PCF.

That is, the first AMF sends a request message to the PCF, which contains the allowed NSSAI, and then the PCF determines the first policy according to the allowed NSSAI and sends it to the first AMF.

As an implementation method, in a scenario where the AMF does not change, before the first slice performs slice authentication, the first AMF receives the requested NSSAI from the UE during the registration process, and the first AMF determines the slice to be accessed. If the first slice in, needs to perform slice authentication, it is determined not to select PCF in the registration process.

As an implementation method, in the scenario where the AMF changes, the AMF before the change (which can become the second AMF) does not select the PCF for the UE, so the PCF information (such as the identification information of the PCF) will not be set in the context of the UE. . Therefore, in the above step 302a, the process for the first AMF to select the PCF is: the first AMF obtains the UE context from the second AMF, and the UE context does not include PCF information, then the first AMF according to the UE context and the allowed NSSAI , Select PCF. That is, when the first AMF determines that the context of the UE does not contain PCF information, it selects a PCF according to the allowed NSSAI.

Based on the above solution, the PCF is not selected before the slice authentication process is performed. After the slice authentication process is performed, the AMF selects the PCF based on the final NSSAI of the UE, so as to avoid the occurrence of the slice authentication process before the selected PCF does not support slice authentication. The slicing after the right process leads to the problem of PCF reselection. Furthermore, the problem of reselection strategy can also be avoided.

In summary, based on the embodiment corresponding to FIG. 3A, the following technical solutions are disclosed:

After the first slice performs slice authentication, the first mobility management network element determines the allowed network slice selection auxiliary information NSSAI. The allowed NSSAI includes the identification information of the slice that the terminal device is allowed to access, and the first slice is the terminal device Among the slices for which access is requested, the slice for performing slice authentication is required; the first mobility management network element selects a policy control network element according to the allowed NSSAI; wherein, the first mobility management network element serves the slice corresponding to the allowed NSSAI.

Based on the network architecture shown in FIG. 1A or FIG. 1B, as shown in FIG. 3B, the present application provides yet another communication method. The method includes the following steps:

Step 301b, the first AMF determines the first NSSAI, the first NSSAI includes the first allowed NSSAI and the pending NSSAI, or the first NSSAI includes the NSSAI subscribed by the UE, and the pending NSSAI includes the required execution in the slice that the UE requests to access The identification information of the slice for slice authentication.

Wherein, this step is executed before slice authentication is performed on the slice corresponding to the pending NSSAI.

It should be noted that in the scenario where the AMF changes, the first AMF here refers to the AMF before the change, that is, the old AMF.

The first allowed NSSAI here refers to the allowed NSSAI determined in the registration process.

Step 302b, the first AMF selects a PCF according to the first NSSAI.

For example, the above solution can be executed in the registration procedure of the UE.

Based on the above solution, the first AMF selects the PCF based on the allowed NSSAI and pending NSSAI, or selects the PCF based on the UE’s contracted NSSAI, so that even if the subsequent allowed NSSAI changes, the new allowed NSSAI will be changed from the allowed NSSAI and NSSAI. Determined from the pending NSSAI, or determined from the NSSAI subscribed by the UE, the PCF still supports the newly allowed NSSAI, so there is no need to reselect the PCF, that is, it will not trigger the reselection of the PCF . Therefore, resource expenditure can be saved.

Optionally, after step 302b, the following steps may be further included:

Step 303b, the first AMF obtains the first policy associated with the first allowed NSSAI from the PCF.

That is, the first AMF sends a request message to the PCF, which contains the first allowed NSSAI, and then the PCF determines the first policy according to the first allowed NSSAI and sends it to the first AMF.

Optionally, after step 302b, the following steps may be further included:

Step 304b: After performing slice authentication on the slice corresponding to the pending NSSAI, the first AMF determines the second allowed NSSAI.

Wherein, the second allowed NSSAI includes the identification information of the slice in the pending NSSAI that successfully performs slice authentication. The second permitted NSSAI also includes the above-mentioned first permitted NSSAI.

Step 305b, the first AMF obtains the second policy associated with the second allowed NSSAI from the PCF.

That is, the first AMF sends a request message to the PCF, which contains the second allowed NSSAI, and then the PCF determines the second policy according to the second allowed NSSAI and sends it to the first AMF.

As an implementation method, in a scenario where AMF handover occurs, after the first AMF (that is, the old AMF) obtains the second policy, if the first AMF cannot serve the second allowed NSSAI, the AMF handover will occur, then The first AMF may send the second policy to the UE. That is, the first AMF (that is, the old AMF) obtains the new strategy (that is, the second strategy) from the PCF and sends it to the UE.

As another implementation method, in the scenario where AMF handover occurs, after step 302b, the first AMF (that is, the old AMF) determines the second allowed NSSAI, and the second allowed NSSAI includes the pending NSSAI that performs slice authentication successfully. The identification information of the slice. If the first AMF cannot serve the second allowed NSSAI, the first AMF sets the first indication information in the context of the UE, and the first indication information is used to instruct the second AMF (that is, the new AMF) to obtain a policy from the PCF. Therefore, after the second AMF obtains the context of the UE from the first AMF, it obtains a new policy (may be referred to as the third policy) from the PCF according to the first indication information therein, and then the second AMF sends the third policy to the UE . That is, in this method, the second AMF (that is, the new AMF) obtains the new strategy (that is, the third strategy) from the PCF and sends it to the UE.

In summary, based on the embodiment corresponding to FIG. 3B, the following technical solutions are disclosed:

The first mobility management network element determines the first NSSAI, the first NSSAI includes the first allowed NSSAI and the pending NSSAI, or the first NSSAI includes the NSSAI subscribed by the terminal device, and the pending NSSAI includes the slice that the terminal device requests to access The identification information of the slice that needs to perform slice authentication; the first mobility management network element selects the policy control network element according to the first NSSAI.

In summary, based on the embodiment corresponding to FIG. 3B, the following technical solutions are also disclosed:

The second mobility management network element obtains the context of the terminal device from the first mobility management network element, the context of the terminal device includes the identification information of the policy control network element and the first indication information; the second mobility management network element determines the allowed NSSAI ; The second mobility management network element obtains the policy associated with the allowed NSSAI from the policy control network element according to the first indication information.

Based on the network architecture shown in FIG. 1A or FIG. 1B, as shown in FIG. 3C, the present application provides yet another communication method. The method includes the following steps:

Step 301c: After the slice authentication is performed on the first slice, the first AMF determines the allowed NSSAI. The allowed NSSAI includes the identification information of the slice that the UE is allowed to access. The first slice is the slice that the UE requests to access. Slice for slice authentication.

The allowed NSSAI contains the identification information of the slices in the requested NSSAI that do not need to perform slice authentication.

Step 302c, the first AMF obtains the first policy associated with the allowed NSSAI from the PCF.

The PCF here is selected in the registration process of the UE, that is, selected before the slice authentication is performed on the first slice.

Step 303c: The first AMF stores the first policy and indication information in the context of the UE, and the indication information is used to instruct the second AMF to send the first policy to the UE.

After obtaining the context of the UE from the first AMF, the second AMF sends the first policy to the UE according to the indication information therein.

The second AMF refers to the changed AMF, which is also called the new AMF.

Based on the above solution, in the scenario where the AMF changes, the old AMF obtains the new policy from the PCF and stores it in the context of the UE, and then the new AMF obtains the new policy from the context of the UE and sends it to the UE. It solves the problem of how to trigger a new AMF to send an updated policy to the UE in a scenario where the AMF changes.

As an implementation method, after the first slice performs slice authentication, when the first slice performs slice authentication successfully, the allowed NSSAI includes the identification information of the first slice, or is understood as The identification information is added to the permitted NSSAI, and a new permitted NSSAI is obtained. When the first slice fails to perform slice authentication, the allowed NSSAI does not include the identification information of the first slice.

In summary, based on the embodiment corresponding to FIG. 3C, the following technical solutions are disclosed:

After the first slice performs slice authentication, the first mobility management network element determines the allowed NSSAI. The allowed NSSAI includes the identification information of the slice that the terminal device is allowed to access. The first slice is the slice that the terminal device requests to access. The first mobility management network element acquires the first policy associated with the allowed NSSAI from the policy control network element; the first mobility management network element stores the first policy and the first policy in the context of the terminal device. Instruction information, the instruction information is used to instruct the second mobility management network element to send the first policy to the terminal device.

Based on the network architecture shown in FIG. 1A or FIG. 1B, as shown in FIG. 3D, the present application provides yet another communication method. The method includes the following steps:

Step 301d: After the first slice performs slice authentication, the first AMF determines the allowed NSSAI.

The allowed NSSAI includes the identification information of the slice to which the UE is allowed to access, and the first slice is the slice for which slice authentication needs to be performed among the slices that the UE requests to access.

The first AMF here refers to the AMF before the change, that is, the old AMF.

Step 302d: If the first AMF cannot serve the allowed NSSAI, the first AMF sets the identification information of the PCF and the first indication information in the context of the UE, and the first indication information is used to instruct the second AMF to obtain a policy from the PCF.

Step 303d: The first AMF sends the allowed NSSAI and second indication information to the UE, where the second indication information is used to instruct the UE to register with the second AMF according to the allowed NSSAI.

Then the UE registers with the second AMF. The second AMF obtains the UE context from the first AMF, which contains the identification information of the PCF and the first indication information. The second AMF obtains the new policy from the PCF according to the first indication information and sends it to UE.

Based on the above solution, in the scenario where the AMF changes, the old AMF selects the PCF and sets the identification information of the PCF and an indication information in the context of the UE, and then the new AMF obtains the identification information of the PCF from the context of the UE. And according to the first indication information, the new AMF is triggered to obtain a new policy from the PCF, thereby solving the problem of how to trigger the new AMF to send the updated policy to the UE in a scenario where the AMF changes.

In summary, based on the embodiment corresponding to FIG. 3D, the following technical solutions are disclosed:

After the first slice performs slice authentication, the first mobility management network element determines the allowed NSSAI. The allowed NSSAI includes the identification information of the slice that the terminal device is allowed to access. The first slice is the slice that the terminal device requests to access. If the first mobility management network element cannot serve the allowed NSSAI, the first mobility management network element sets the identification information and first indication information of the policy control network element in the context of the terminal device, The first indication information is used to instruct the second mobility management network element to obtain a policy from the policy control network element. ; The first mobility management network element sends the allowed NSSAI and second indication information to the terminal device, the second indication information is used to instruct the terminal device to register with the second mobility management network element according to the allowed NSSAI.

As shown in FIG. 4, it is a schematic flowchart of another communication method provided by this application. This embodiment is aimed at a scenario where AMF does not change before and after the NSSAA process.

The method includes the following steps:

Step 401: The UE initiates a registration process, and sends a Registration Request (Registration Request) message to the AMF. The Registration Request message carries the requested NSSAI (Requested NSSAI).

In step 402, the AMF executes the main authentication procedure of the permanent identity of the UE. After the procedure is successful, the AMF obtains the UE's subscription data from the UDM. The subscription data includes the S-NSSAI subscribed by the UE and indication information corresponding to each S-NSSAI, and the indication information is used to indicate whether the S-NSSAI needs to perform NSSAA.

For example, the S-NSSAI and indication information of the subscription in the subscription data of the UE are shown in Table 2.

Table 2

签约的S-NSSAISigned S-NSSAI	指示信息：该S-NSSAI是否需要执行NSSAAInstruction information: whether the S-NSSAI needs to execute NSSAA
S-NSSAI-1S-NSSAI-1	是Yes
S-NSSAI-2S-NSSAI-2	是Yes
S-NSSAI-3S-NSSAI-3	否no

For example, the AMF can call the UDM service operation Nudm_SDM_Get to obtain the UE's subscription data, and the UDM sends the UE's subscription data to the AMF through Nudm_SDM_Get response.

In step 403, the AMF determines whether the NSSAA process needs to be executed, and if the NSSAA process needs to be executed, it determines not to select the PCF first.

Example 1: For example, the Requested NSSAI carried by the UE includes S-NSSAI-1, S-NSSAI-2, and S-NSSAI-3, where S-NSSAI-1 and S-NSSAI-2 need to perform the NSSAA process, S-NSSAI-3 There is no need to perform the NSSAA process, the AMF determines that the UE needs to perform the NSSAA process after this registration process.

Example 2: For example, the Requested NSSAI carried by the UE is S-NSSAI-A, S-NSSAI-B, and S-NSSAI-C, where S-NSSAI-A is mapped to S-NSSAI-1, and S-NSSAI-B is mapped to S-NSSAI-B. NSSAI-2 mapping, S-NSSAI-C and S-NSSAI-3 mapping, and S-NSSAI-1 and S-NSSAI-2 need to perform the NSSAA process, and S-NSSAI-3 does not need to perform the NSSAA process. Then the AMF determines that the UE needs to perform the NSSAA procedure on S-NSSAI-1 and S-NSSAI-2 after this registration procedure.

Step 404: The Registration Accept message sent by the AMF to the UE carries one or more of allowed NSSAI (Allowed NSSAI), pending NSSAI (Pending NSSAI), and rejected NSSAI (Rejected NSSAI).

Optionally, the AMF may also send a pending cause value to the UE: waiting for NSSAA, and the cause value is used to indicate to the UE that those S-NSSAIs that require NSSAA are in a pending state.

Optionally, for Rejected NSSAI, the AMF may also send a rejection reason value to the UE: the current area is not available.

Among them, Allowed NSSAI includes S-NSSAI in the requested NSSAI that does not require NSSAA, Pending NSSAI includes S-NSSAI in the requested NSSAI that requires NSSAA, and Rejected NSSAI includes the UE in the requested NSSAI that is not available in the current area. S-NSSAI.

For example 1 in the previous example, for example, Allowed NSSAI=S-NSSAI-3, Pending NSSAI=S-NSSAI-1+S-NSSAI-2, the reason value to be determined: waiting for NSSAA. Rejected NSSAI is empty. For example 2 in the previous example, Allowed NSSAI=S-NSSAI-C, Pending NSSAI=S-NSSAI-A+S-NSSAI-C, reason value: waiting for NSSAA.

At the same time, the AMF stores the Allowed NSSAI in this step in the context of the UE on the AMF.

Step 405: After the registration acceptance message is sent, the AMF executes the NSSAA procedure for the pending S-NSSAI.

For example, following the example 1 in the above example, Pending NSSAI=S-NSSAI-1+S-NSSAI-2, since both S-NSSAI-1 and S-NSSAI-2 are HPLMN S-NSSAI, then AMF will compare S-NSSAI -1 and S-NSSAI-2 execute the NSSAA process.

Following example 2 in the above example, Pending NSSAI=S-NSSAI-A and S-NSSAI-B, since S-NSSAI-A is mapped to S-NSSAI-1, and S-NSSAI-B is mapped to S-NSSAI-2, Then AMF executes the NSSAA process on S-NSSAI-1 and S-NSSAI-2. If the NSSAA result of S-NSSAI-1 is NSSAA success, it can also be understood that the NSSAA result of S-NSSAI-A is NSSAA success, then access to S-NSSAI-A is allowed; if the NSSAA result of S-NSSAI-1 is NSSAA Failure can also be understood as the NSSAA result of S-NSSAI-A is NSSAA failure, and then access to S-NSSAI-A is denied. If the NSSAA result of S-NSSAI-2 is NSSAA success, it can also be understood that the NSSAA result of S-NSSAI-B is NSSAA success, then access to S-NSSAI-B is allowed; if the NSSAA result of S-NSSAI-2 is NSSAA Failure can also be understood as the result of NSSAA of S-NSSAI-B as NSSAA failure, and access to S-NSSAI-B is denied.

This step 405 is an optional step. When there is an S-NSSAI that needs to execute the NSSAA process, step 405 is executed. Otherwise, step 405 is not executed.

It should be noted that if there are multiple S-NSSAIs that need to execute the NSSAA process, step 405 can be executed multiple times.

Step 406: After the execution of the NSSAA process is completed, the AMF determines whether the Allowed NSSAI of the UE needs to be updated according to the result of the process. If there is a successful NSSAA slice, the S-NSSAI corresponding to the successful NSSAA slice is added to step 404 and sent to In the Allowed NSSAI of the UE, a new Allowed NSSAI (new Allowed NSSAI) is obtained.

Optionally, in this step, the AMF also determines Rejected NSSAI, and the Rejected NSSAI includes the S-NSSAI corresponding to the NSSAA failed slice in the Pending NSSAI.

Continuing the description with Example 1 in the above example, if the NSSAA result of S-NSSAI-1 is NSSAA success, and the NSSAA result of S-NSSAI-2 is NSSAA failure, the AMF is stored in the context of the UE in accordance with Allowed in step 404 NSSAI, add S-NSSAI-1 to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-1+S-NSSAI-3. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-2. Optionally, it also generates a rejection reason value: NSSAA failed. Continuing the description with Example 2 in the above example, if the NSSAA result of S-NSSAI-A is NSSAA success, and the NSSAA result of S-NSSAI-B is NSSAA failure, the AMF is stored according to the Allowed in the context of the UE in step 404. NSSAI, adding S-NSSAI-A to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-A+S-NSSAI-C. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-B. Optionally, it also generates a rejection reason value: NSSAA failed.

Step 407: If the current AMF can continue to serve the UE, the AMF requests the NRF to find a suitable PCF according to the new Allowed NSSAI determined in step 406.

For example, the AMF calls the NRF service operation Nnrf_NFDiscovery_Request, which carries the SUPI of the UE and the new Allowed NSSAI determined in step 406.

The current AMF can continue to serve the UE means that the AMF can support the new Allowed NSSAI determined in step 406. So AMF does not need to be changed.

Step 408: The NRF determines a suitable PCF, and sends the PCF ID (PCF ID) to the AMF.

That is, NEF determines the appropriate PCF based on SUPI and new Allowed NSSAI.

As an implementation method, NRF can return Nnrf_NFDiscovery_Response to AMF, carrying PCF ID.

Step 409: Based on the PCF ID returned by the NRF, the AMF sends an AM Policy Association Establishment (AM Policy Association) request to the PCF.

For example, AMF calls the service operation of PCF: Npcf_AMPolicyControl_Create, which carries SUPI, new Allowed NSSAI.

Step 410: The PCF sends an AM policy (AM policy for new Allowed NSSAI) and a policy control request trigger (Policy Control Request Triggers) generated based on the new Allowed NSSAI to the AMF.

For example, PCF returns Npcf_AMPolicyControl_Create Response to AMF, which carries AM policy for new Allowed NSSAI and Policy Control Request Triggers.

Among them, the AM policy is generated by the PCF according to the new Allowed NSSAI, and the AM policy of this step can also be called the AM policy for new Allowed NSSAI. AM policy includes but is not limited to: air interface access technology/spectrum selection priority index (Index to RAT/Frequency Selection Priority, RFSP index), user aggregate maximum bit rate (Aggregate Maximum Bit Rate, UE-AMBR), and service area restriction ( Service Area Restrictions).

Policy Control Request Triggers refers to policy control request triggers, or policy event reporting triggers. When the corresponding trigger conditions are met (such as the UE's Allowed NSSAI changes), the AMF can initiate the AM policy association update process, thereby Update the corresponding strategy.

After step 410, it further includes step 410a and step 410b:

Step 410a: Based on the PCF ID returned by the NRF, the AMF sends a UE Policy Association Establishment (UE Policy Association) request to the PCF.

For example, AMF calls PCF's servicing operation: Npcf_UEPolicyControl Create Request, which carries SUPI.

Step 410b, the PCF sends a UE policy (UE policy) to the AMF.

For example, PCF returns Npcf_UEPolicyControl Create Response to AMF, which carries UE policy.

The UE policy includes but is not limited to: UE access selection policy, such as Access Network Discovery&Selection Policy (ANDSP), and PDU Session Selection related policies, such as UE routing policy (UE Route Selection Policy, URSP)).

Step 411: The AMF sends a configuration update request (configuration update request) message to the UE, which carries the new Allowed NSSAI, and is based on the AM policy and the UE policy generated by the new Allowed NSSAI.

Optionally, if the rejected NSSAI (Rejected NSSAI) is also determined in step 406, the configuration update request message may also carry the rejected NSSAI.

In this embodiment, in the initial registration process, if the AMF determines that it needs to perform the NSAA process on some S-NSSAI in the Requested NSSAI, the AMF does not select the PCF first, but waits for the end of the NSSAA process, the AMF according to the UE’s final Allowed NSSAI (new Allowed NSSAI) selects the appropriate PCF and obtains the AM policy. This method can avoid the problems of PCF reselection and frequent refresh of policies.

As shown in FIG. 5, it is a schematic flowchart of another communication method provided by this application. This embodiment is aimed at a scenario where AMF changes before and after the NSSAA process.

The method includes the following steps:

Step 501: The UE initiates a registration process, and sends a Registration Request (Registration Request) message to the old AMF (old AMF), and the Registration Request message carries the requested NSSAI (Requested NSSAI).

The old AMF here refers to the AMF selected by the access network to serve the UE during the registration process, or can be understood as the AMF that serves the UE for the first time in the registration process. The old AMF involved in the present invention may also be called initial AMF (initial AMF) or current AMF (serving AMF).

In step 502, the old AMF executes the primary authentication procedure of the permanent identity of the UE. After the procedure is successful, the old AMF obtains the UE's subscription data from the UDM. The subscription data includes the S-NSSAI subscribed by the UE and indication information corresponding to each S-NSSAI, and the indication information is used to indicate whether the S-NSSAI needs to perform NSSAA.

For example, the S-NSSAI and indication information of the subscription in the subscription data of the UE are as shown in Table 2 above.

For example, the old AMF can call the servicing operation Nudm_SDM_Get of UDM to obtain the subscription data of the UE, and the UDM sends the subscription data of the UE to the old AMF through Nudm_SDM_Get response.

In step 503, the old AMF determines whether the NSSAA process needs to be executed, and if the NSSAA process needs to be executed, it determines not to select PCF first.

It should be noted that in the present invention, the method by which the old AMF determines that the S-NSSAI in the requested NSSAI needs to execute the NSSAA can have two meanings:

The first type: a certain S-NSSAI in the requested NSSAI belongs to the contracted S-NSSAI, and the contracted S-NSSAI needs to execute NSSAA, then old AMF determines that the S-NSSAI in the requested NSSAI needs to execute NSSAA.

Specifically, the old AMF determines whether the S-NSSAI that needs to perform the NSSAA process is included in the Requested NSSAI based on the UE's subscription data. If it does, the old AMF determines that the UE needs to perform the NSSAA process after this registration process. That is, it can be understood that the requested NSSAI includes the slice type (HPLMN S-NSSAI) of the home domain network.

Example 1: For example, the Requested NSSAI carried by the UE includes S-NSSAI-1, S-NSSAI-2, and S-NSSAI-3, where S-NSSAI-1 and S-NSSAI-2 need to perform the NSSAA process, S-NSSAI-3 There is no need to perform the NSSAA process, the old AMF determines that the UE needs to perform the NSSAA process after this registration process.

The second type: a certain S-NSSAI in the requested NSSAI can be mapped to a contracted S-NSSAI, and the contracted S-NSSAI needs to execute NSSAA, then old AMF determines that the S-NSSAI in the requested NSSAI needs to execute NSSAA.

Specifically, the old AMF judges that a certain S-NSSAI included in the Requested NSSAI can be mapped to the HPLMN S-NSSAI based on the UE’s subscription data, and the HPLMN S-NSSAI needs to perform the NSSAA process, then the old AMF determines that the UE is registered this time After the process, the NSSAA process needs to be executed.

Example 2: For example, the Requested NSSAI carried by the UE is S-NSSAI-A, S-NSSAI-B, and S-NSSAI-C, where S-NSSAI-A is mapped to S-NSSAI-1, and S-NSSAI-B is mapped to S-NSSAI-B. NSSAI-2 mapping, S-NSSAI-C and S-NSSAI-3 mapping, and S-NSSAI-1 and S-NSSAI-2 need to perform the NSSAA process, and S-NSSAI-3 does not need to perform the NSSAA process. Then the old AMF determines that the UE needs to perform the NSSAA process on S-NSSAI-1 and S-NSSAI-2 after this registration process. If the NSSAA result of S-NSSAI-1 is NSSAA success, it can also be understood that the NSSAA result of S-NSSAI-A is NSSAA success, then access to S-NSSAI-A is allowed; if the NSSAA result of S-NSSAI-1 is NSSAA Failure can also be understood as the NSSAA result of S-NSSAI-A is NSSAA failure, and then access to S-NSSAI-A is denied. If the NSSAA result of S-NSSAI-2 is NSSAA success, it can also be understood that the NSSAA result of S-NSSAI-B is NSSAA success, then access to S-NSSAI-B is allowed; if the NSSAA result of S-NSSAI-2 is NSSAA Failure can also be understood as the result of NSSAA of S-NSSAI-B as NSSAA failure, and access to S-NSSAI-B is denied.

Step 504: The Registration Accept message sent by the old AMF to the UE carries one or more of allowed NSSAI (Allowed NSSAI), pending NSSAI (Pending NSSAI), and rejected NSSAI (Rejected NSSAI).

At the same time, the old AMF stores the Allowed NSSAI in this step in the context of the UE on the old AMF.

Step 505: After the registration acceptance message is sent, the old AMF executes the NSSAA process for the pending S-NSSAI.

It should be noted that in the present invention, the old AMF performing NSSAA for the S-NSSAI in the pending NSSAI can have two meanings:

The first type: a certain S-NSSAI in the pending NSSAI belongs to the contracted S-NSSAI, and the contracted S-NSSAI needs to perform NSSAA, then the old AMF performs NSSAA on the S-NSSAI.

For example, following the example 1 in the above example, Pending NSSAI=S-NSSAI-1+S-NSSAI-2, since both S-NSSAI-1 and S-NSSAI-2 are HPLMN S-NSSAI, then old AMF is against S- NSSAI-1 and S-NSSAI-2 execute the NSSAA process.

The second type: a certain S-NSSAI in the pending NSSAI is mapped to the contracted S-NSSAI, and the contracted S-NSSAI needs to perform NSSAA, then old AMF performs NSSAA for the contracted S-NSSAI.

Following example 2 in the above example, Pending NSSAI=S-NSSAI-A and S-NSSAI-B, since S-NSSAI-A is mapped to S-NSSAI-1, and S-NSSAI-B is mapped to S-NSSAI-2, Then the old AMF performs the NSSAA process on S-NSSAI-1 and S-NSSAI-2.

This step 505 is an optional step. When there is an S-NSSAI that needs to execute the NSSAA process, step 505 is executed. Otherwise, step 505 is not executed.

It should be noted that if there are multiple S-NSSAIs that need to execute the NSSAA process, step 505 can be executed multiple times.

Step 506: After the execution of the NSSAA process is completed, the old AMF determines whether the Allowed NSSAI of the UE needs to be updated according to the result of the process. If there is a successful NSSAA slice, the S-NSSAI corresponding to the successful NSSAA slice is added to step 504 and sent In the Allowed NSSAI of the UE, a new Allowed NSSAI (new Allowed NSSAI) is obtained.

Optionally, in this step, the old AMF also determines Rejected NSSAI, and the Rejected NSSAI includes the S-NSSAI corresponding to the NSSAA failed slice in the Pending NSSAI.

Continuing the description with Example 1 in the above example, if the NSSAA result of S-NSSAI-1 is NSSAA success, and the NSSAA result of S-NSSAI-2 is NSSAA failure, the AMF is based on the Allowed NSSAI stored in the context of the UE in step 504 , Add S-NSSAI-1 to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-1+S-NSSAI-3. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-2. Optionally, it also generates a rejection reason value: NSSAA failed. Continuing the description with Example 2 in the above example, if the NSSAA result of S-NSSAI-A is NSSAA success, and the NSSAA result of S-NSSAI-B is NSSAA failure, the old AMF is based on the Allowed stored in the context of the UE in step 504. NSSAI, adding S-NSSAI-A to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-A+S-NSSAI-C. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-B. Optionally, it also generates a rejection reason value: NSSAA failed.

Step 507: If the current AMF (ie, old AMF) cannot continue to serve the UE, the old AMF needs to trigger the AMF reallocation. The old AMF sends a configuration update request message to the UE, which carries new Allowed NSSAI and indication information. The indication information is used to instruct the UE to use new Allowed NSSAI as the requested NSSAI to initiate the registration process immediately after receiving the new Allowed NSSAI.

The current AMF cannot continue to serve the UE means that the current AMF does not support the new Allowed NSSAI determined in step 506, so the AMF needs to be changed.

Step 508: The UE initiates a registration process according to the new Allowed NSSAI and the indication information. In this registration process, the UE registers with a new AMF (new AMF), that is, the new AMF serves the UE, where the new AMF supports the slice indicated by the new Allowed NSSAI.

The UE sends a Requested NSSAI during the registration process, and the Requested NSSAI includes the new Allowed NSSAI in step 507 above.

Step 509: The new AMF obtains the context of the UE from the old AMF request.

Since old AMF has not selected PCF, the context of UE does not contain PCF ID and related policy information, so new AMF cannot obtain PCF ID and related policy information from old AMF, which will trigger new AMF to select PCF for the first time.

Step 510: The new AMF determines the new Allowed NSSAI for the UE and stores it in the context of the UE.

It should be noted that the new Allowed NSSAI of the UE determined by the new AMF and the new Allowed NSSAI sent by the old AMF to the UE in step 507 may be the same or different. This is because the new AMF needs to further determine the final Allowed NSSAI for the UE based on the congestion of the current network slice.

In step 511, the AMF requests the NRF to find a suitable PCF according to the new Allowed NSSAI determined in step 510.

For example, the AMF calls the NRF service operation Nnrf_NFDiscovery_Request, which carries the SUPI of the UE and the new Allowed NSSAI determined in step 510.

In step 512, the NRF determines a suitable PCF, and sends the PCF ID (PCF ID) to the AMF.

Step 513: The new AMF sends an AM Policy Association Establishment (AM Policy Association) request to the PCF based on the PCF ID returned by the NRF.

For example, AMF calls the PCF service operation: Npcf_AMPolicyControl_Create, which carries SUPI, new Allowed NSSAI).

Step 514: The PCF sends an AM policy (AM policy for new Allowed NSSAI) and a policy control request trigger (Policy Control Request Triggers) generated based on the new Allowed NSSAI to the new AMF.

For example, PCF returns Npcf_AMPolicyControl_Create Response to new AMF, which carries AM policy for new Allowed NSSAI and Policy Control Request Triggers.

Among them, the AM policy is generated by the PCF according to the new Allowed NSSAI, and the AM policy of this step can also be called the AM policy for new Allowed NSSAI. AM policy includes but is not limited to: air interface access technology/spectrum selection priority index, user aggregation maximum bit rate, and service area limitation.

Policy Control Request Triggers refers to policy control request triggers, or policy event reporting triggers. When the corresponding trigger conditions are met (such as the UE’s Allowed NSSAI changes), new AMF can initiate the AM policy association update process. Thereby updating the corresponding strategy.

After step 514, it also includes step 514a and step 514b:

In step 514a, the new AMF sends a UE Policy Association Establishment (UE Policy Association Establishment) request to the PCF based on the PCF ID returned by the NRF.

For example, new AMF calls the PCF service operation: Npcf_UEPolicyControl Create Request, which carries SUPI.

In step 514b, the PCF sends a UE policy (UE policy) to the new AMF.

For example, PCF returns Npcf_UEPolicyControl Create Response to new AMF, which carries UE policy.

The UE policy includes but is not limited to: UE access selection strategy (such as access network discovery and selection strategy), and PDU session selection-related strategies (such as UE routing selection strategy).

Step 515: The AMF sends a registration acceptance message to the UE, which carries the new Allowed NSSAI, based on the AM policy and the UE policy generated by the new Allowed NSSAI.

Based on this embodiment, in the initial registration process, if old AMF determines that it needs to perform the NSAA process on some S-NSSAI in the requested NSSAI, then old AMF does not select PCF. After the NSSAA process ends, if old AMF does not support new Allowed NSSAI, AMF relocation is required and reselected to new AMF. Since the new AMF does not obtain the PCF ID from the old AMF, the new AMF selects the appropriate PCF according to the final allowed NSSAI of the UE and obtains policy information. This embodiment can avoid the problems of PCF reselection and frequent policy refresh. Therefore, resource expenditure can be saved.

As shown in FIG. 6, a schematic flow diagram of another communication method provided by this application. This embodiment is aimed at a scenario where AMF does not change before and after the NSSAA process.

The method includes the following steps:

In step 601, the UE initiates a registration process and sends a registration request (Registration Request) message to the AMF. The registration request message carries the requested NSSAI (Requested NSSAI).

In step 602, the AMF executes the main authentication procedure of the permanent identity of the UE. After the procedure is successful, the AMF obtains the UE's subscription data from the UDM. The subscription data includes the S-NSSAI subscribed by the UE and indication information corresponding to each S-NSSAI, and the indication information is used to indicate whether the S-NSSAI needs to perform NSSAA.

In step 603, the AMF requests the NRF to find a suitable PCF according to the first NSSAI and SUPI.

As an implementation manner, the first NSSAI here includes Allowed NSSAI and Pending S-NSSAI.

Among them, Allowed NSSAI includes S-NSSAI that does not require NSSAA among requested NSSAIs, and Pending NSSAI includes S-NSSAI that requires NSSAA among requested NSSAIs.

It should be noted that, in the present invention, the method in which the AMF determines in step 602 that the S-NSSAI in the requested NSSAI needs to execute NSSAA is the same as step 403, and will not be repeated.

As another implementation manner, the first NSSAI here may include an S-NSSAI (subscribed NSSAI) subscribed by the UE.

For example, the AMF can call the NRF service operation Nnrf_NFDiscovery_Request, which carries the SUPI and the first NSSAI of the UE.

In step 604, the NRF determines a suitable PCF, and sends the PCF ID (PCF ID) to the AMF.

That is, NEF determines a suitable PCF based on SUPI and the first NSSAI.

It can be seen that the slice information used by the PCF selected in this step is the first NSSAI. If the first NSSAI includes Allowed NSSAI and Pending S-NSSAI, then the PCF selected by NRF must support the slices corresponding to Allowed NSSAI and Pending S-NSSAI . If the first NSSAI includes subscribed NSSAI, then the PCF selected by NRF must support the slice corresponding to subscribed NSSAI.

Step 605: Based on the PCF ID returned by the NRF, the AMF sends an AM Policy Association Establishment (AM Policy Association) request to the PCF.

For example, AMF calls the PCF service operation: Npcf_AMPolicyControl_Create, which carries SUPI, Allowed NSSAI).

Step 606: The PCF sends an AM policy (AM policy for Allowed NSSAI) and a policy control request trigger (Policy Control Request Triggers) generated based on the Allowed NSSAI to the AMF.

For example, PCF returns Npcf_AMPolicyControl_Create Response to AMF, which carries AM policy for Allowed NSSAI and Policy Control Request Triggers.

Among them, the AM policy is generated by the PCF according to Allowed NSSAI, and the AM policy of this step can also be called AM policy for Allowed NSSAI. AM policy includes but is not limited to: air interface access technology/spectrum selection priority index, user aggregation maximum bit rate, and service area limitation.

Step 607: The Registration Accept message sent by the AMF to the UE carries one or more of allowed NSSAI (Allowed NSSAI), pending NSSAI (Pending NSSAI), and rejected NSSAI (Rejected NSSAI).

The registration acceptance message also carries the AM policy generated based on the Allowed NSSAI that the AMF received from the PCF in step 606.

Among them, Allowed NSSAI includes S-NSSAI that does not require NSSAA, Pending NSSAI includes S-NSSAI that requires NSSAA, and Rejected NSSAI includes S-NSSAI that is not available in the current area for the UE in the requested NSSAI.

Example 1: For example, the Requested NSSAI carried by the UE includes S-NSSAI-1, S-NSSAI-2, and S-NSSAI-3. Among them, S-NSSAI-1 and S-NSSAI-2 need to perform the NSSAA process, and S-NSSAI- 3 There is no need to perform the NSSAA process, then Allowed NSSAI=S-NSSAI-3, Pending NSSAI=S-NSSAI-1+S-NSSAI-2, and pending reason value: waiting for NSSAA. Rejected NSSAI is empty.

Example 2: For example, the Requested NSSAI carried by the UE is S-NSSAI-A, S-NSSAI-B, and S-NSSAI-C, where S-NSSAI-A is mapped to S-NSSAI-1, and S-NSSAI-B is mapped to S- NSSAI-2 mapping, S-NSSAI-C and S-NSSAI-3 mapping, and S-NSSAI-1 and S-NSSAI-2 need to perform the NSSAA process, S-NSSAI-3 does not need to perform the NSSAA process, then Allowed NSSAI= S-NSSAI-C, Pending NSSAI=S-NSSAI-A+S-NSSAI-B, pending reason value: waiting for NSSAA. Rejected NSSAI is empty.

After step 607, it further includes step 607a, step 607b, and step 607c:

Step 607a: Based on the PCF ID returned by the NRF, the AMF sends a UE Policy Association Establishment (UE Policy Association) request to the PCF.

In step 607b, the PCF sends a UE policy (UE policy) to the AMF.

Step 607c: The AMF sends a configuration update request (configuration update request) message to the UE, which carries the UE policy.

In step 608, the AMF executes the NSSAA process for the pending S-NSSAI.

It should be noted that, in the present invention, in step 608, the AMF executes NSSAA in the S-NSSAI of the pending NSSAI, and the method is the same as step 405.

For example, following the example 1 in the above example, Pending NSSAI=S-NSSAI-1+S-NSSAI-2, since both S-NSSAI-1 and S-NSSAI-2 are HPLMN S-NSSAI, then AMF will compare S-NSSAI -1 and S-NSSAI-2 execute the NSSAA process. Following example 2 in the above example, Pending NSSAI=S-NSSAI-A and S-NSSAI-B, since S-NSSAI-A is mapped to S-NSSAI-1, and S-NSSAI-B is mapped to S-NSSAI-2, Then AMF executes the NSSAA process on S-NSSAI-1 and S-NSSAI-2. If the NSSAA result of S-NSSAI-1 is NSSAA success, it can also be understood that the NSSAA result of S-NSSAI-A is NSSAA success, then access to S-NSSAI-A is allowed; if the NSSAA result of S-NSSAI-1 is NSSAA Failure can also be understood as the NSSAA result of S-NSSAI-A is NSSAA failure, and then access to S-NSSAI-A is denied. If the NSSAA result of S-NSSAI-2 is NSSAA success, it can also be understood that the NSSAA result of S-NSSAI-B is NSSAA success, then access to S-NSSAI-B is allowed; if the NSSAA result of S-NSSAI-2 is NSSAA Failure can also be understood as the result of NSSAA of S-NSSAI-B as NSSAA failure, and access to S-NSSAI-B is denied.

This step 608 is an optional step. When there is an S-NSSAI that needs to execute the NSSAA process, step 608 is executed. Otherwise, step 608 is not executed.

It should be noted that if there are multiple S-NSSAIs that need to execute the NSSAA process, step 608 can be executed multiple times.

Step 609: After the execution of the NSSAA process is completed, the AMF determines whether the Allowed NSSAI of the UE needs to be updated according to the result of the process. If there is a successful NSSAA slice, the S-NSSAI corresponding to the successful NSSAA slice is added to step 607 and sent to In the Allowed NSSAI of the UE, a new Allowed NSSAI (new Allowed NSSAI) is obtained.

Continuing the description with Example 1 in the above example, if the NSSAA result of S-NSSAI-1 is NSSAA success, and the NSSAA result of S-NSSAI-2 is NSSAA failure, the AMF is stored in the context of the UE in accordance with Allowed in step 607 NSSAI, add S-NSSAI-1 to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-1+S-NSSAI-3. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-2. Optionally, it also generates a rejection reason value: NSSAA failed. Continuing the description with Example 2 in the above example, if the NSSAA result of S-NSSAI-A is NSSAA success, and the NSSAA result of S-NSSAI-B is NSSAA failure, the AMF is based on the Allowed NSSAI stored in the context of the UE in step 607. , Add S-NSSAI-A to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-A+S-NSSAI-C. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-B. Optionally, it also generates a rejection reason value: NSSAA failed.

Step 610: If the current AMF can continue to serve the UE, the AMF decides to send an AM Policy Association Modification (AM Policy Association Modification) request to the PCF according to the Allowed NSSAI change (or change of allowed NSSAI) of the UE included in the Policy Control Request Triggers. The AM policy association modification request includes SUPI and new Allowed NSSAI, and the new Allowed NSSAI is the new Allowed NSSAI determined in step 609.

That is, the AMF determines that the allowed NSSAI has changed, and determines that the Policy Control Request Triggers is triggered, so it re-requests the PCF for a new AM policy.

For example, AMF calls the PCF service operation: Npcf_AMPolicyControl_Update, which carries SUPI, new Allowed NSSAI).

Step 611: The PCF sends an AM policy (AM policy for new Allowed NSSAI) generated based on the new Allowed NSSAI to the AMF.

For example, PCF returns Npcf_AMPolicyControl_Update Response to AMF, which carries AM policy for new Allowed NSSAI.

Step 612: The AMF sends a configuration update request (configuration update request) message to the UE, which carries a new Allowed NSSAI and an AM policy generated based on the new Allowed NSSAI.

Optionally, if the rejected NSSAI (Rejected NSSAI) is also determined in step 609, the configuration update request message may also carry the rejected NSSAI.

Based on this embodiment, in the registration process, AMF uses a set consisting of Allowed NSSAI and Pending NSSAI or AMF uses subscribed NSSAI to select PCF. When the NSSAA succeeds, it can avoid that the PCF selected before the NSSAA process does not support the new Allowed NSSAI of the UE after the NSSAA process, thereby avoiding reselecting the PCF. Therefore, resource expenditure can be saved.

As shown in FIG. 7, a schematic flowchart of another communication method provided by this application. This embodiment is aimed at a scenario where AMF changes before and after the NSSAA process.

The method includes the following steps:

Step 701: The UE initiates a registration process, and sends a Registration Request (Registration Request) message to the old AMF (old AMF), and the Registration Request message carries the requested NSSAI (Requested NSSAI).

In step 702, the old AMF executes the primary authentication procedure of the permanent identity of the UE. After the procedure is successful, the old AMF obtains the UE's subscription data from the UDM. The subscription data includes the S-NSSAI subscribed by the UE and indication information corresponding to each S-NSSAI, and the indication information is used to indicate whether the S-NSSAI needs to perform NSSAA.

For example, the old AMF can call the servicing operation Nudm_SDM_Get of UDM to obtain the subscription data of the UE, and the UDM sends the subscription data of the UE to the AMF through Nudm_SDM_Get response.

Step 703: The old AMF requests the NRF to find a suitable PCF according to the first NSSAI and SUPI.

It should be noted that in the present invention, in step 703, the old AMF determines that the S-NSSAI in the requested NSSAI needs to execute NSSAA. The method is the same as that in step 503, and will not be repeated.

For example, the old AMF can call the NRF service operation Nnrf_NFDiscovery_Request, which carries the SUPI and the first NSSAI of the UE.

Step 704: The NRF determines a suitable PCF, and sends the PCF ID (PCF ID) to the old AMF.

That is, NEF determines a suitable PCF based on SUPI and the first NSSAI.

As an implementation method, NRF can return Nnrf_NFDiscovery_Response to old AMF, carrying PCF ID.

It can be seen that the slice information used by the PCF selected in this step is the first NSSAI. If the first NSSAI includes Allowed NSSAI and Pending S-NSSAI, then the PCF selected by NRF must support the slices corresponding to Allowed NSSAI and Pending S-NSSAI ability. If the first NSSAI includes subscribed NSSAI, then the PCF selected by NRF must support the slice corresponding to subscribed NSSAI.

Step 705: Based on the PCF ID returned by the NRF, the old AMF sends an AM Policy Association Establishment (AM Policy Association) request to the PCF. The AM policy association establishment request carries SUPI and Allowed NSSAI.

For example, the old AMF calls the PCF service operation: Npcf_AMPolicyControl_Create, which carries SUPI, Allowed NSSAI).

Step 706: The PCF sends an AM policy (AM policy for Allowed NSSAI) and a policy control request trigger (Policy Control Request Triggers) generated based on the Allowed NSSAI to the old AMF.

For example, PCF returns Npcf_AMPolicyControl_Create Response to old AMF, which carries AM policy for Allowed NSSAI and Policy Control Request Triggers.

Policy Control Request Triggers refers to policy control request triggers, or policy event reporting triggers. When the corresponding trigger conditions are met (for example, the UE's Allowed NSSAI changes), the old AMF can initiate the AM policy association update process. Thereby updating the corresponding strategy.

Step 707: The Registration Accept message sent by the old AMF to the UE carries one or more of allowed NSSAI (Allowed NSSAI), pending NSSAI (Pending NSSAI), and rejected NSSAI (Rejected NSSAI), and Carry the AM policy generated based on the allowed NSSAI.

Optionally, the old AMF may also send a pending cause value to the UE: waiting for NSSAA, and the cause value is used to indicate to the UE that those S-NSSAIs that require NSSAA are in a pending state.

Optionally, for Rejected NSSAI, old AMF may also send a rejection reason value to the UE: the current area is not available.

After step 707, it also includes step 707a, step 707b, and step 707c:

Step 707a: Based on the PCF ID returned by the NRF, the old AMF sends a UE Policy Association Establishment (UE Policy Association) request to the PCF.

For example, old AMF calls PCF's servicing operation: Npcf_UEPolicyControl Create Request, which carries SUPI.

In step 707b, the PCF sends a UE policy (UE policy) to the old AMF.

For example, PCF returns Npcf_UEPolicyControl Create Response to old AMF, which carries UE policy.

Step 707c: The AMF sends a configuration update request (configuration update request) message to the UE, which carries the UE policy.

Step 708, the old AMF executes the NSSAA process for the pending S-NSSAI.

For example, following the example 1 in the above example, Pending NSSAI=S-NSSAI-1+S-NSSAI-2, since both S-NSSAI-1 and S-NSSAI-2 are HPLMN S-NSSAI, then old AMF is against S- NSSAI-1 and S-NSSAI-2 execute the NSSAA process. Following example 2 in the above example, Pending NSSAI=S-NSSAI-A and S-NSSAI-B, since S-NSSAI-A is mapped to S-NSSAI-1, and S-NSSAI-B is mapped to S-NSSAI-2, Then AMF executes the NSSAA process on S-NSSAI-1 and S-NSSAI-2. If the NSSAA result of S-NSSAI-1 is NSSAA success, it can also be understood that the NSSAA result of S-NSSAI-A is NSSAA success, then access to S-NSSAI-A is allowed; if the NSSAA result of S-NSSAI-1 is NSSAA Failure can also be understood as the NSSAA result of S-NSSAI-A is NSSAA failure, and then access to S-NSSAI-A is denied. If the NSSAA result of S-NSSAI-2 is NSSAA success, it can also be understood that the NSSAA result of S-NSSAI-B is NSSAA success, then access to S-NSSAI-B is allowed; if the NSSAA result of S-NSSAI-2 is NSSAA Failure can also be understood as the result of NSSAA of S-NSSAI-B as NSSAA failure, and access to S-NSSAI-B is denied.

This step 708 is an optional step. When there is an S-NSSAI that needs to execute the NSSAA process, step 708 is executed. Otherwise, step 708 is not executed.

It should be noted that if there are multiple S-NSSAIs that need to execute the NSSAA process, step 708 can be executed multiple times.

In step 709, after the execution of the NSSAA process is completed, the AMF determines whether the Allowed NSSAI of the UE needs to be updated according to the result of the process. If there is a successful NSSAA slice, the S-NSSAI corresponding to the successful NSSAA slice is added to step 707 and sent to In the Allowed NSSAI of the UE, a new Allowed NSSAI (new Allowed NSSAI) is obtained.

Continuing the description with Example 1 in the above example, if the NSSAA result of S-NSSAI-1 is NSSAA success, and the NSSAA result of S-NSSAI-2 is NSSAA failure, the AMF will store the Allowed NSSAI in the context of the UE in step 707. , Add S-NSSAI-1 to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-1+S-NSSAI-3. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-2. Optionally, it also generates a rejection reason value: NSSAA failed. Continuing the description with Example 2 in the above example, if the NSSAA result of S-NSSAI-A is NSSAA success, and the NSSAA result of S-NSSAI-B is NSSAA failure, then AMF will store the Allowed NSSAI in the context of the UE in step 707. , Add S-NSSAI-A to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-A+S-NSSAI-C. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-B. Optionally, it also generates a rejection reason value: NSSAA failed.

Step 710: If the current AMF (ie, old AMF) cannot continue to serve the UE, the old AMF needs to trigger the AMF reallocation. At the same time, the old AMF sets indication information in the context of the UE to indicate that the allowed NSSAI change satisfies the Policy Control Request Triggers.

The current AMF cannot continue to serve the UE means that the current AMF does not support the new Allowed NSSAI determined in step 709, so the AMF needs to be changed.

Optionally, the old AMF also adds the policy control request triggers (Policy Control Request Triggers) obtained from the PCF to the context of the UE.

Step 711: The old AMF sends a configuration update request message to the UE, which carries new Allowed NSSAI and indication information. The indication information is used to instruct the UE to use the new Allowed NSSAI as the requested NSSAI to initiate a registration process immediately after receiving the new Allowed NSSAI.

Step 712: The UE initiates a registration process according to the new Allowed NSSAI and the indication information. In this registration process, the UE registers with a new AMF (new AMF), that is, the new AMF serves the UE, where the new AMF supports the slice indicated by the new Allowed NSSAI.

The UE sends a Requested NSSAI during the registration process, and the Requested NSSAI includes the new Allowed NSSAI in step 709.

Step 713: The new AMF obtains the context of the UE from the old AMF request.

Since the old AMF selects the PCF, the context of the UE on the old AMF contains the PCF ID and indication information. The indication information is used to indicate that the allowed NSSAI change satisfies the Policy Control Request Triggers. Or it can be understood that the indication information is used to instruct the new AMF to obtain a new policy from the PCF. Therefore, the new AMF obtains the PCF ID and indication information from the old AMF, and triggers the acquisition of an updated policy from the PCF according to the indication information.

Step 714: The new AMF determines the new Allowed NSSAI for the UE and stores it in the context of the UE.

It should be noted that the new Allowed NSSAI of the UE determined by the new AMF may be the same or different from the new Allowed NSSAI determined by the old AMF in step 709. This is because the new AMF needs to further determine the final Allowed NSSAI for the UE based on the congestion of the current network slice.

Step 715: The new AMF decides to send an AM Policy Association Modification (AM Policy Association Modification) request to the PCF according to the indication information in the context of the UE. The AM policy association modification request includes SUPI and new Allowed NSSAI, and the new Allowed NSSAI is the new Allowed NSSAI determined in step 714.

That is, the new AMF determines that the allowed NSSAI has changed, and the Policy Control Request Triggers is determined to be triggered, so it re-requests the PCF for a new AM policy.

For example, new AMF calls the PCF service operation: Npcf_AMPolicyControl_Update, which carries SUPI, new Allowed NSSAI).

Step 716: The PCF sends an AM policy (AM policy for new Allowed NSSAI) generated based on the new Allowed NSSAI to the AMF.

For example, PCF returns Npcf_AMPolicyControl_Update Response to new AMF, which carries AM policy for new Allowed NSSAI.

Step 717: The new AMF sends a registration acceptance message to the UE, which carries the new Allowed NSSAI and the AM policy generated based on the new Allowed NSSAI.

Based on this embodiment, in the registration process, old AMF uses a set consisting of Allowed NSSAI and Pending NSSAI, or AMF uses subscribed NSSAI to select PCF. When the NSSAA succeeds, it can avoid that the PCF selected before the NSSAA process does not support the new Allowed NSSAI of the UE after the NSSAA process, thereby avoiding reselecting the PCF. In addition, the new AMF can trigger the acquisition of a new AM policy from the PCF according to the indication information stored in the context of the UE by the old AMF, and the new AMF can re-determine the new Allowed NSSAI according to the new Allowed NSSAI determined by the old AMF, and add the new AM The new Allowed NSSAI determined by the policy and new AMF is sent to the UE.

As shown in FIG. 8, it is a schematic flowchart of another communication method provided by this application. This embodiment is aimed at a scenario where AMF changes before and after the NSSAA process.

The method includes the following steps:

In step 801, the UE initiates a registration process and sends a registration request (Registration Request) message to the old AMF (old AMF), and the registration request message carries the requested NSSAI (Requested NSSAI).

In step 802, the old AMF executes the primary authentication procedure of the permanent identity of the UE. After the procedure is successful, the old AMF obtains the UE's subscription data from the UDM. The subscription data includes the S-NSSAI subscribed by the UE and indication information corresponding to each S-NSSAI, and the indication information is used to indicate whether the S-NSSAI needs to perform NSSAA.

In step 803, the old AMF requests the NRF to find a suitable PCF according to Allowed NSSAI and SUPI.

Among them, Allowed NSSAI includes S-NSSAI that does not require NSSAA among the requested NSSAI.

For example, the old AMF can call the NRF service operation Nnrf_NFDiscovery_Request, which carries the SUPI and Allowed NSSAI of the UE.

In step 804, the NRF determines a suitable PCF, and sends the PCF ID (PCF ID) to the old AMF.

That is, NEF determines a suitable PCF based on SUPI and Allowed NSSAI.

In step 805, the old AMF sends an AM Policy Association Establishment (AM Policy Association) request to the PCF based on the PCF ID returned by the NRF. The AM policy association establishment request carries SUPI and Allowed NSSAI.

For example, old AMF calls the servicing operation of PCF: Npcf_AMPolicyControl_Create, which carries SUPI, Allowed NSSAI).

Step 806: The PCF sends an AM policy (AM policy for Allowed NSSAI) and a policy control request trigger (Policy Control Request Triggers) generated based on the Allowed NSSAI to the old AMF.

Policy Control Request Triggers refers to policy control request triggers, or policy event reporting triggers. When the corresponding trigger conditions are met (such as the UE’s Allowed NSSAI changes), the old AMF can initiate the AM policy association update process. Thereby updating the corresponding strategy.

Step 807: The Registration Accept message sent by the old AMF to the UE carries one or more of Allowed NSSAI (Allowed NSSAI), Pending NSSAI (Pending NSSAI), and Rejected NSSAI (Rejected NSSAI), and Carry the AM policy generated based on the allowed NSSAI.

It should be noted that, in the present invention, in step 807, the old AMF determines that the S-NSSAI in the requested NSSAI needs to execute the NSSAA. The method is the same as that in step 503, and will not be repeated.

After step 807, it also includes step 807a, step 807b, and step 807c:

Step 807a: Based on the PCF ID returned by the NRF, the old AMF sends a UE Policy Association Establishment (UE Policy Association) request to the PCF.

Step 807b, the PCF sends a UE policy (UE policy) to the old AMF.

Step 807c: The old AMF sends a configuration update request (configuration update request) message to the UE, which carries the UE policy.

Step 808, the old AMF executes the NSSAA process for the pending S-NSSAI.

This step 808 is an optional step. When there is an S-NSSAI that needs to execute the NSSAA process, step 808 is executed. Otherwise, step 808 is not executed.

It should be noted that if there are multiple S-NSSAIs that need to execute the NSSAA process, step 808 can be executed multiple times.

In step 809, after the execution of the NSSAA process is completed, the AMF determines whether the Allowed NSSAI of the UE needs to be updated according to the result of the process. If there is a successful NSSAA slice, the S-NSSAI corresponding to the successful NSSAA slice is added to step 807 and sent to In the Allowed NSSAI of the UE, a new Allowed NSSAI (new Allowed NSSAI) is obtained.

Continuing the description with Example 1 in the above example, if the NSSAA result of S-NSSAI-1 is NSSAA success, and the NSSAA result of S-NSSAI-2 is NSSAA failure, the AMF will store the Allowed NSSAI in the context of the UE in step 807. , Add S-NSSAI-1 to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-1+S-NSSAI-3. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-2. Optionally, it also generates a rejection reason value: NSSAA failed. Continuing the description with Example 2 in the above example, if the NSSAA result of S-NSSAI-A is NSSAA success, and the NSSAA result of S-NSSAI-B is NSSAA failure, then AMF will follow the Allowed NSSAI stored in the context of the UE in step 807. , Add S-NSSAI-A to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-A+S-NSSAI-C. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-B. Optionally, it also generates a rejection reason value: NSSAA failed.

Step 810: If the current AMF (ie, old AMF) cannot continue to serve the UE, the old AMF needs to trigger the AMF reallocation. At the same time, the old AMF judges that the allowed NSSAI change satisfies the Policy Control Request Triggers based on the Policy Control Request Triggers, and the old AMF decides to first obtain the new allowed NSSAI corresponding new AM policy from the PCF.

Step 811: The old AMF sends an AM Policy Association Modification (AM Policy Association Modification) request to the PCF. The AM policy association modification request includes SUPI and new Allowed NSSAI, and the new Allowed NSSAI is the new Allowed NSSAI determined in step 809.

For example, old AMF calls PCF's servicing operation: Npcf_AMPolicyControl_Update, which carries SUPI, new Allowed NSSAI).

In step 812, the PCF sends an AM policy (AM policy for new Allowed NSSAI) generated based on the new Allowed NSSAI to the old AMF.

Step 813: The old AMF stores the AM policy generated based on the new Allowed NSSAI in the context of the UE.

Step 814: The old AMF sends a configuration update request message to the UE, which carries new Allowed NSSAI and indication information. The indication information is used to instruct the UE to use the new Allowed NSSAI as the requested NSSAI to initiate a registration process immediately after receiving the new Allowed NSSAI.

As an implementation method, the configuration update request message also carries AM policy information generated based on new Allowed NSSAI. In this way, the subsequent new AMF does not need to send the AM policy information generated based on the new Allowed NSSAI to the UE.

As another implementation method, if old AMF does not send AM policy information generated based on new Allowed NSSAI to the UE through a configuration update request message, old AMF can set an indication information in the context of the UE on old AMF. The information is used to indicate: new AMF sends AM policy information in the context of the UE (that is, AM policy information generated based on new Allowed NSSAI) to the UE. In this way, after the subsequent new AMF obtains the UE context from the old AMF, it can determine to send the AM policy information generated based on the new Allowed NSSAI to the UE according to the above indication information in the UE context.

Step 815: The UE initiates a registration process according to the new Allowed NSSAI and the instruction information. In this registration process, the UE registers with a new AMF (new AMF), that is, the new AMF serves the UE, where the new AMF supports the slice indicated by the new Allowed NSSAI.

The UE sends a Requested NSSAI during the registration process, and the Requested NSSAI includes the new Allowed NSSAI in step 809 above.

Step 816, the new AMF obtains the context of the UE from the old AMF request.

Since the old AMF selected the PCF, the context of the UE on the old AMF includes the PCF ID and the AM policy generated based on the new Allowed NSSAI. Therefore, the new AMF obtains the PCF ID and the AM policy generated based on the new Allowed NSSAI from the old AMF.

Optionally, the context of the UE also includes indication information, which is used to indicate that new AMF sends AM policy information in the context of the UE (that is, AM policy information generated based on new Allowed NSSAI) to the UE.

In step 817, the new AMF determines the new Allowed NSSAI for the UE and stores it in the context of the UE.

It should be noted that the new Allowed NSSAI of the UE determined by the new AMF and the new Allowed NSSAI determined by the old AMF in step 809 may be the same or different. This is because the new AMF needs to further determine the final Allowed NSSAI for the UE based on the congestion of the current network slice.

Step 818: The new AMF sends a registration acceptance message to the UE, which carries new Allowed NSSAI.

Optionally, if the context of the UE also contains indication information, the new AMF carries AM policy information in the registration acceptance message according to the indication information, and the AM policy information is obtained by the new AMF from the context of the UE.

Based on this embodiment, in the registration process, old AMF uses the method of the prior art and Allowed NSSAI to select PCF. When the NSSAA succeeds, the old AMF determines the new Allowed NSSAI, and obtains the updated AM policy from the PCF according to the new Allowed NSSAI and stores it in the context of the UE on the old AMF. After the subsequent switch to new AMF, after new AMF obtains the UE context from old AMF, it can obtain the updated AM policy from the UE context, which eliminates the need to obtain the updated AM policy from the PCF again. The problem of frequent refresh of the strategy. Therefore, resource expenditure can be saved.

As shown in FIG. 9, it is a schematic flowchart of another communication method provided by this application. This embodiment is aimed at a scenario where AMF changes before and after the NSSAA process.

The method includes the following steps:

Step 901: The UE initiates a registration process, and sends a Registration Request (Registration Request) message to the old AMF (old AMF), and the Registration Request message carries the requested NSSAI (Requested NSSAI).

In step 902, the old AMF executes the primary authentication procedure of the permanent identity of the UE. After the procedure is successful, the old AMF obtains the UE's subscription data from the UDM. The subscription data includes the S-NSSAI subscribed by the UE and indication information corresponding to each S-NSSAI, and the indication information is used to indicate whether the S-NSSAI needs to perform NSSAA.

For example, the S-NSSAI and indication information of the subscription in the subscription data of the UE are as shown in Table 1 above.

In step 903, the old AMF requests the NRF to find a suitable PCF according to the Allowed NSSAI and SUPI.

Among them, Allowed NSSAI includes S-NSSAI that does not require NSSAA in the requested NSSAI.

In step 904, the NRF determines a suitable PCF, and sends the PCF ID (PCF ID) to the old AMF.

That is, NEF determines a suitable PCF based on SUPI and Allowed NSSAI.

Step 905: Based on the PCF ID returned by the NRF, the old AMF sends an AM Policy Association Establishment (AM Policy Association) request to the PCF. The AM policy association establishment request carries SUPI and Allowed NSSAI.

In step 906, the PCF sends an AM policy (AM policy for Allowed NSSAI) and a policy control request trigger (Policy Control Request Triggers) generated based on the Allowed NSSAI to the old AMF.

Step 907: The Registration Accept message sent by the old AMF to the UE carries one or more of allowed NSSAI (Allowed NSSAI), pending NSSAI (Pending NSSAI), and rejected NSSAI (Rejected NSSAI), and Carry the AM policy generated based on the allowed NSSAI.

It should be noted that, in the present invention, in step 907, the old AMF determines that the S-NSSAI in the requested NSSAI needs to execute NSSAA. The method is the same as that in step 503, and will not be repeated.

Example 1: The Requested NSSAI carried by the UE includes S-NSSAI-1, S-NSSAI-2, and S-NSSAI-3. Among them, S-NSSAI-1 and S-NSSAI-2 need to perform the NSSAA process, and S-NSSAI-3 does not The NSSAA process needs to be executed, for example, Allowed NSSAI=S-NSSAI-3, Pending NSSAI=S-NSSAI-1+S-NSSAI-2, and the pending reason value: waiting for NSSAA. Rejected NSSAI is empty.

After step 907, it also includes step 907a, step 907b, and step 907c:

Step 907a: Based on the PCF ID returned by the NRF, the old AMF sends a UE Policy Association Establishment (UE Policy Association) request to the PCF.

In step 907b, the PCF sends a UE policy (UE policy) to the old AMF.

Step 907c: The old AMF sends a configuration update request (configuration update request) message to the UE, which carries the UE policy.

In step 908, the old AMF executes the NSSAA process for the pending S-NSSAI.

This step 908 is an optional step. When there is an S-NSSAI that needs to execute the NSSAA process, step 908 is executed. Otherwise, step 908 is not executed.

It should be noted that if there are multiple S-NSSAIs that need to execute the NSSAA process, step 908 can be executed multiple times.

In step 909, after the execution of the NSSAA process is completed, the AMF determines whether the Allowed NSSAI of the UE needs to be updated according to the result of the process. If there is a successful NSSAA slice, the S-NSSAI corresponding to the successful NSSAA slice is added to step 907 and sent to In the Allowed NSSAI of the UE, a new Allowed NSSAI (new Allowed NSSAI) is obtained.

Continuing the description with Example 1 in the above example, if the NSSAA result of S-NSSAI-1 is NSSAA success, and the NSSAA result of S-NSSAI-2 is NSSAA failure, then AMF will store the Allowed NSSAI in the context of the UE in step 907. , Add S-NSSAI-1 to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-1+S-NSSAI-3. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-2. Optionally, it also generates a rejection reason value: NSSAA failed. Continuing the description with Example 2 in the above example, if the NSSAA result of S-NSSAI-A is NSSAA success, and the NSSAA result of S-NSSAI-B is NSSAA failure, the AMF is based on the Allowed NSSAI stored in the context of the UE in step 907 , Add S-NSSAI-A to the Allowed NSSAI of the UE, that is, the Allowed NSSAI is updated to: S-NSSAI-A+S-NSSAI-C. And generate a rejected NSSAI. The rejected NSSAI includes S-NSSAI-B. Optionally, it also generates a rejection reason value: NSSAA failed.

Step 910: If the current AMF (ie, old AMF) cannot continue to serve the UE, the old AMF needs to trigger the AMF reallocation. At the same time, the old AMF sets indication information in the context of the UE to indicate that the allowed NSSAI change satisfies the Policy Control Request Triggers.

Step 911: The old AMF sends a configuration update request message to the UE, which carries new Allowed NSSAI and indication information. The indication information is used to instruct the UE to use the new Allowed NSSAI as the requested NSSAI to initiate a registration process immediately after receiving the new Allowed NSSAI.

Step 912, the UE initiates a registration process according to the new Allowed NSSAI and the instruction information. In this registration process, the UE registers with a new AMF (new AMF), that is, the new AMF serves the UE, where the new AMF supports the slice indicated by the new Allowed NSSAI.

Step 913, the new AMF obtains the context of the UE from the old AMF request.

Step 914: The new AMF determines the new Allowed NSSAI for the UE and stores it in the context of the UE.

Step 915: The new AMF decides to send an AM Policy Association Modification (AM Policy Association Modification) request to the PCF according to the indication information in the context of the UE. The AM policy association modification request includes SUPI and new Allowed NSSAI, and the new Allowed NSSAI is the new Allowed NSSAI determined in step 714.

In step 916, the PCF sends an AM policy (AM policy for new Allowed NSSAI) generated based on the new Allowed NSSAI to the AMF.

Step 917: The new AMF sends a registration acceptance message to the UE, which carries the new Allowed NSSAI and the AM policy generated based on the new Allowed NSSAI.

Based on this embodiment, in the registration process, old AMF uses the method of the prior art and Allowed NSSAI to select PCF. The new AMF may trigger the acquisition of a new AM policy from the PCF according to the indication information stored in the context of the UE by the old AMF, and the new AMF may determine the new Allowed NSSAI according to the requested NSSAI, and send the new AM policy to the UE.

The foregoing mainly introduces the solution provided in this application from the perspective of interaction between various network elements. It can be understood that, in order to realize the above-mentioned functions, each network element described above includes hardware structures and/or software modules corresponding to each function. Those skilled in the art should easily realize that in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the present invention can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software-driven hardware depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered as going beyond the scope of the present invention.

It can be understood that, in each of the foregoing method embodiments, corresponding to the steps or operations implemented by the terminal device, they can also be implemented by components (such as chips or circuits) configured in the terminal device, corresponding to the steps or operations implemented by the access device. It can also be implemented by a component (such as a chip or circuit) configured on the access device, corresponding to the steps or operations implemented by the policy control network element, or can be implemented by a component (such as a chip or circuit) configured on the policy control network element.

Refer to FIG. 10, which is a schematic diagram of a communication device provided by an embodiment of this application. The device is used to implement the steps performed by the corresponding mobility management network element, or the first mobility management network element, or the second mobility management network element in the foregoing method embodiment. As shown in FIG. 10, the device 1000 includes The acquiring unit 1010, the determining unit 1020, and the selecting unit 1030. Optionally, it further includes a receiving unit 1040, a sending unit 1050, and a setting unit 1060.

In the first embodiment:

The determining unit 1020 is configured to determine the allowed network slice selection auxiliary information NSSAI after the first slice performs slice authentication, where the allowed NSSAI includes the identification information of the slice that the terminal device is allowed to access, and the first slice Among the slices for which access is requested for the terminal device, slices that need to perform slice authentication; a selection unit 1030, configured to select a policy control network element according to the allowed NSSAI; wherein, the communication device serves the allowed NSSAI The corresponding slice.

In a possible implementation method, the obtaining unit 1010 is configured to obtain the first policy associated with the allowed NSSAI from the policy control network element.

In a possible implementation method, the receiving unit 1040 is configured to receive the requested NSSAI from the terminal device in the registration process before the first slice performs slice authentication, and the requested NSSAI includes all The identification information of the slice that the terminal device requests to access; the determining unit 1020 is further configured to determine that the first slice in the slice that is requested to access needs to perform slice authentication, and then it is determined in the registration process The policy control network element is not selected.

In a possible implementation method, the selection unit 1030 is specifically configured to obtain the context of the terminal device from the second mobility management network element, and the context of the terminal device does not include the information of the policy control network element, The second mobility management network element is a network element that receives the requested NSSAI from the terminal device during the registration process, and the requested NSSAI includes the identification information of the slice that the terminal device requests to access; The context of the terminal device and the allowed NSSAI select the policy control network element.

In a possible implementation method, when the first slice performs slice authentication successfully, the allowed NSSAI includes the identification information of the first slice; or, when the first slice performs slice authentication If the permission fails, the allowed NSSAI does not include the identification information of the first slice.

In the second embodiment:

The determining unit 1020 is configured to determine a first NSSAI, where the first NSSAI includes a first allowed NSSAI and a pending NSSAI, or the first NSSAI includes a contracted NSSAI of a terminal device, and the pending NSSAI includes the terminal Identification information of the slice that needs to perform slice authentication among the slices that the device requests to access; the selection unit 1030 is configured to select a policy control network element according to the first NSSAI.

In a possible implementation method, the obtaining unit 1010 is configured to obtain the first policy associated with the first allowed NSSAI from the policy control network element.

In a possible implementation method, the determining unit 1020 is further configured to determine a second allowed NSSAI after the slice corresponding to the pending NSSAI performs slice authentication, and the second allowed NSSAI includes the Identification information of the slice that successfully performs slice authentication in the pending NSSAI; the obtaining unit 1010 is configured to obtain the second policy associated with the second allowed NSSAI from the policy control network element.

In a possible implementation method, the sending unit 1050 is configured to send the second policy to the terminal device if the communication device cannot serve the second allowed NSSAI.

In a possible implementation method, the determining unit 1020 is further configured to determine a second allowed NSSAI after the slice corresponding to the pending NSSAI performs slice authentication, and the second allowed NSSAI includes the Identification information of the slice that successfully performs slice authentication in the pending NSSAI; the setting unit 1060 is configured to set first indication information in the context of the terminal device if the communication device cannot serve the second allowed NSSAI, The first indication information is used to instruct the second mobility management network element to obtain a policy from the policy control network element.

In the third embodiment:

The obtaining unit 1010 is configured to obtain a context of a terminal device from a first mobility management network element, where the context of the terminal device includes identification information of the policy control network element and first indication information; and, according to the first indication information, Obtain the policy associated with the allowed NSSAI from the policy control network element. The determining unit 1020 is configured to determine the allowed NSSAI.

In a possible implementation method, the first indication information is used to instruct the communication device to obtain a policy from the policy control network element.

In the fourth embodiment:

The determining unit 1020 is configured to determine the allowed NSSAI after the first slice performs slice authentication, the allowed NSSAI includes identification information of the slice that the terminal device is allowed to access, and the first slice is the slice that the terminal device requests to access The slice that needs to perform slice authentication; the obtaining unit 1010 is used to obtain the first policy associated with the allowed NSSAI from the policy control network element; the sending unit 1050 is used to store the first policy and instruction information in the context of the terminal device, The indication information is used to instruct the second mobility management network element to send the first policy to the terminal device.

In the fifth embodiment:

The determining unit 1020 is configured to determine the allowed NSSAI after the first slice performs slice authentication, the allowed NSSAI includes identification information of the slice that the terminal device is allowed to access, and the first slice is the slice that the terminal device requests to access The slice that needs to perform slice authentication; the setting unit 1060 is used to set the identification information and first indication information of the policy control network element in the context of the terminal device if the communication device cannot serve the allowed NSSAI, and the first indication information is used to indicate The second mobility management network element obtains the policy from the policy control network element. The sending unit 1050 is configured to send the allowed NSSAI and second indication information to the terminal device, where the second indication information is used to instruct the terminal device to register with the second mobility management network element according to the allowed NSSAI.

It can be understood that each of the above-mentioned units may also be referred to as a module or a circuit, etc., and each of the above-mentioned units may be provided independently, or may be fully or partially integrated.

In some possible implementation manners, the foregoing receiving unit 1040 and sending unit 1050 may also be implemented by a transceiving unit, or in other words, the receiving unit 1040 and the sending unit 1050 may also be collectively referred to as a transceiving unit. The above-mentioned acquisition unit 1010, determination unit 1020, selection unit 1030, and setting unit 1060 may also be implemented by processing units, or the acquisition unit 1010, determination unit 1020, selection unit 1030, and setting unit 1060 may also be collectively referred to as processing units.

The foregoing receiving unit 1040, sending unit 1050, or transceiving unit may also be referred to as a communication interface, and the foregoing processing unit may also be referred to as a processor.

Optionally, the above-mentioned communication device 1000 may further include a storage unit for storing data or instructions (also referred to as codes or programs), and each of the above-mentioned units may interact or couple with the storage unit to implement the corresponding method or Function. For example, the processing unit may read data or instructions in the storage unit, so that the communication device implements the method in the foregoing embodiment.

It should be understood that the division of units in the above device is only a division of logical functions, and may be fully or partially integrated into one physical entity in actual implementation, or may be physically separated. In addition, the units in the device can be all implemented in the form of software called by processing elements; they can also be all implemented in the form of hardware; part of the units can also be implemented in the form of software called by the processing elements, and some of the units can be implemented in the form of hardware. For example, each unit can be a separate processing element, or it can be integrated in a certain chip of the device for implementation. In addition, it can also be stored in the memory in the form of a program, which is called and executed by a certain processing element of the device. Function. In addition, all or part of these units can be integrated together or implemented independently. The processing element described here can also become a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above units may be implemented by an integrated logic circuit of hardware in a processor element or implemented in a form of being called by software through a processing element.

In an example, the unit in any of the above devices may be one or more integrated circuits configured to implement the above methods, for example: one or more application specific integrated circuits (ASICs), or, one or Multiple microprocessors (digital singnal processors, DSPs), or, one or more field programmable gate arrays (Field Programmable Gate Arrays, FPGAs), or a combination of at least two of these integrated circuits. For another example, when the unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processors that can call programs. For another example, these units can be integrated together and implemented in the form of a system-on-a-chip (SOC).

The above receiving unit (for example, the receiving unit) is an interface circuit of the device for receiving signals from other devices. For example, when the device is implemented as a chip, the receiving unit is an interface circuit used by the chip to receive signals from other chips or devices. The above unit for sending (for example, the sending unit) is an interface circuit of the device for sending signals to other devices. For example, when the device is implemented in the form of a chip, the sending unit is an interface circuit used by the chip to send signals to other chips or devices.

Referring to FIG. 11, this is a schematic structural diagram of a mobility management network element provided by an embodiment of this application, which is used to implement the mobility management network element, or the first mobility management network element, or the second mobility management network in the above embodiments. Meta operations. As shown in FIG. 11, the mobility management network element includes: a processor 1110, an interface 1130, and optionally, a memory 1120. The interface 1130 is used to implement communication with other devices.

The method executed by the mobility management network element in the above embodiment can be implemented by the processor 1110 calling a program stored in a memory (which may be the memory 1120 in the mobility management network element or an external memory). That is, the apparatus for a mobility management network element may include a processor 1110 that calls a program in a memory to execute the method executed by the mobility management network element in the above method embodiment. The processor here may be an integrated circuit with signal processing capability, such as a CPU. The apparatus for the mobility management network element may be implemented by one or more integrated circuits configured to implement the above method. For example: one or more ASICs, or, one or more microprocessors DSP, or, one or more FPGAs, etc., or a combination of at least two of these integrated circuit forms. Or, the above implementations can be combined.

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

A person of ordinary skill in the art can understand that the various digital numbers involved in this application, such as the first, second, third, and fourth, are only for the convenience of description and are not used to limit the scope of the embodiments of the present application, but also represent Priority. "And/or" describes the association relationship of the associated objects, indicating that there can be three types of relationships, for example, A and/or B, which can mean: A alone exists, A and B exist at the same time, and B exists alone. The character "/" generally indicates that the associated objects before and after are in an "or" relationship. "At least one" means one or more. At least two refers to two or more. "At least one", "any one" or similar expressions refer to any combination of these items, including any combination of a single item (a) or a plurality of items (a). For example, at least one (piece, species) of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or Multiple. "Multiple" refers to two or more than two, and other quantifiers are similar.

It should be understood that in the various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the order of execution. The execution order of the processes should be determined by their functions and internal logic, and should not be used in the embodiments of the present invention. The implementation process constitutes any limitation.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative, for example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined or It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.

The various illustrative logic units and circuits described in the embodiments of this application can be implemented by general-purpose processors, digital signal processors, application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, Discrete gates or transistor logic, discrete hardware components, or any combination of the above are designed to implement or operate the described functions. The general-purpose processor may be a microprocessor. Alternatively, the general-purpose processor may also be any traditional processor, controller, microcontroller, or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration. accomplish.

The steps of the method or algorithm described in the embodiments of the present application can be directly embedded in hardware, a software unit executed by a processor, or a combination of the two. The software unit can be stored in random access memory (Random Access Memory, RAM), flash memory, read-only memory (Read-Only Memory, ROM), EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM or this Any other storage media in the field. Exemplarily, the storage medium may be connected to the processor, so that the processor can read information from the storage medium, and can store and write information to the storage medium. Optionally, the storage medium may also be integrated into the processor. The processor and the storage medium can be arranged in the ASIC.

These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. The instructions provide steps for implementing the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

In one or more exemplary designs, the aforementioned functions described in this application can be implemented in hardware, software, firmware, or any combination of the three. If implemented in software, these functions can be stored on a computer-readable medium, or transmitted on the computer-readable medium in the form of one or more instructions or codes. Computer-readable media include computer storage media and communication media that facilitate the transfer of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general-purpose or special computer. For example, such computer-readable media may include, but are not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other device that can be used to carry or store instructions or data structures and Other program code media that can be read by general-purpose or special computers, or general-purpose or special processors. In addition, any connection can be appropriately defined as a computer-readable medium, for example, if the software is from a website, server, or other remote source through a coaxial cable, fiber optic computer, twisted pair, or digital subscriber line (DSL) Or transmitted by wireless means such as infrared, wireless and microwave are also included in the definition of computer-readable media. The said disks and discs include compressed disks, laser disks, optical discs, digital versatile discs (English: Digital Versatile Disc, abbreviated as: DVD), floppy disks and Blu-ray discs. Disks usually copy data with magnetism. Discs usually use lasers to copy data optically. The combination of the above can also be contained in a computer readable medium.

Those skilled in the art should be aware that, in one or more of the foregoing examples, the functions described in this application can be implemented by hardware, software, firmware, or any combination thereof. When implemented by software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on the computer-readable medium. The computer-readable medium includes a computer storage medium and a communication medium, where the communication medium includes any medium that facilitates the transfer of a computer program from one place to another. The storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

The specific implementations described above further describe the purpose, technical solutions and beneficial effects of this application in detail. It should be understood that the above are only specific implementations of this application and are not intended to limit the scope of this application. The scope of protection, any modification, equivalent replacement, improvement, etc. made on the basis of the technical solution of this application shall be included in the scope of protection of this application. The above description of the specification of this application can enable any technology in the field to utilize or realize the content of this application. Any modification based on the disclosed content should be considered obvious in the art. The basic principles described in this application can be applied to other modifications. Without departing from the nature and scope of the invention of this application. Therefore, the content disclosed in this application is not only limited to the described embodiments and designs, but can also be extended to the maximum range consistent with the principles of this application and the new features disclosed.

Although the application has been described in combination with specific features and embodiments, it is obvious that various modifications and combinations can be made without departing from the spirit and scope of the application. Accordingly, the specification and drawings are merely exemplary descriptions of the application as defined by the appended claims, and are deemed to cover any and all modifications, changes, combinations or equivalents within the scope of the application. Obviously, those skilled in the art can make various changes and modifications to the application without departing from the scope of the application. In this way, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these modifications and variations.

Claims

A communication method, characterized in that it comprises:

After the slice authentication is performed on the first slice, the first mobility management network element determines the allowed network slice selection auxiliary information NSSAI. The allowed NSSAI includes the identification information of the slices that the terminal device is allowed to access. A slice is a slice for which slice authentication needs to be performed among slices that the terminal device requests to access;

The first mobility management network element selects a policy control network element according to the allowed NSSAI;

Wherein, the first mobility management network element serves the slice corresponding to the allowed NSSAI.
The method of claim 1, further comprising:

The first mobility management network element obtains the first policy associated with the allowed NSSAI from the policy control network element.
The method of claim 1 or 2, further comprising:

Before the first slice performs slice authentication, the first mobility management network element receives the requested NSSAI from the terminal device in the registration process, and the requested NSSAI includes the terminal device requesting access The identification information of the slice;

The first mobility management network element determines that the first slice in the slice requested for access needs to perform slice authentication, and then determines that the policy control network element is not selected in the registration process.
The method according to claim 1 or 2, wherein the first mobility management network element selects a policy control network element according to the allowed NSSAI, comprising:

The first mobility management network element obtains the context of the terminal device from a second mobility management network element, and the context of the terminal device does not include the information of the policy control network element, and the second mobility management network element In order to receive the requested NSSAI network element from the terminal device in the registration process, the requested NSSAI includes the identification information of the slice to which the terminal device requests access;

The first mobility management network element selects the policy control network element according to the context of the terminal device and the allowed NSSAI.
The method according to any one of claims 1-4, wherein:

When the first slice performs slice authentication successfully, the allowed NSSAI includes the identification information of the first slice; or,

When the slice authentication for the first slice fails, the allowed NSSAI does not include the identification information of the first slice.
A communication method, characterized in that it comprises:

The first mobility management network element determines the first NSSAI, the first NSSAI includes the first allowed NSSAI and the pending NSSAI, or the first NSSAI includes the NSSAI subscribed by the terminal device, and the pending NSSAI includes the Identification information of the slice that needs to perform slice authentication among the slices that the terminal device requests to access;

The first mobility management network element selects a policy control network element according to the first NSSAI.
The method of claim 6, further comprising:

The first mobility management network element obtains the first policy associated with the first allowed NSSAI from the policy control network element.
The method according to claim 6 or 7, further comprising:

After performing slice authentication on the slice corresponding to the pending NSSAI, the first mobility management network element determines a second allowed NSSAI, and the second allowed NSSAI includes the successful execution of slice authentication in the pending NSSAI The identification information of the slice;

The first mobility management network element obtains a second policy associated with the second allowed NSSAI from the policy control network element.
The method of claim 8, further comprising:

If the first mobility management network element cannot serve the second allowed NSSAI, the first mobility management network element sends the second policy to the terminal device.
The method according to claim 6 or 7, further comprising:

After performing slice authentication on the slice corresponding to the pending NSSAI, the first mobility management network element determines a second allowed NSSAI, and the second allowed NSSAI includes the successful execution of slice authentication in the pending NSSAI The identification information of the slice;

If the first mobility management network element cannot serve the second permitted NSSAI, the first mobility management network element sets first indication information in the context of the terminal device, and the first indication information is used Instructing the second mobility management network element to obtain a policy from the policy control network element.
A communication method, characterized in that it comprises:

The second mobility management network element obtains the context of the terminal device from the first mobility management network element, where the context of the terminal device includes the identification information of the policy control network element and the first indication information;

The second mobility management network element determines the allowed NSSAI;

The second mobility management network element obtains the policy associated with the allowed NSSAI from the policy control network element according to the first indication information.
The method according to claim 11, wherein the first indication information is used to instruct the second mobility management network element to obtain a policy from the policy control network element.
A communication device, characterized in that it comprises:

The determining unit is configured to determine the allowed network slice selection auxiliary information NSSAI after the first slice performs slice authentication, where the allowed NSSAI includes the identification information of the slice that the terminal device is allowed to access, and the first slice is The slice for which slice authentication needs to be performed among slices that the terminal device requests to access;

The selection unit is configured to select a policy control network element according to the allowed NSSAI;

Wherein, the communication device serves the slice corresponding to the allowed NSSAI.
The device according to claim 13, further comprising an obtaining unit, configured to obtain the first policy associated with the allowed NSSAI from the policy control network element.
The apparatus according to claim 13 or 14, further comprising a receiving unit, configured to receive the requested NSSAI from the terminal device in the registration process before the first slice performs slice authentication, The requested NSSAI includes identification information of the slice to which the terminal device requests to access;

The determining unit is further configured to determine that the first slice in the slice requested for access needs to perform slice authentication, and then determine that the policy control network element is not selected in the registration process.
The apparatus according to claim 13 or 14, wherein the selection unit is specifically configured to obtain the context of the terminal device from a second mobility management network element, and the context of the terminal device does not include policy control Network element information, the second mobility management network element is a network element that receives the requested NSSAI from the terminal device during the registration process, and the requested NSSAI includes the identifier of the slice to which the terminal device requests access Information; According to the context of the terminal device and the allowed NSSAI, select the policy control network element.
The device according to any one of claims 13-16, characterized in that:

When the first slice performs slice authentication successfully, the allowed NSSAI includes the identification information of the first slice; or,

When the slice authentication for the first slice fails, the allowed NSSAI does not include the identification information of the first slice.
A communication device, characterized in that it comprises:

The determining unit is configured to determine a first NSSAI, where the first NSSAI includes a first allowed NSSAI and a pending NSSAI, or the first NSSAI includes a contracted NSSAI of a terminal device, and the pending NSSAI includes the terminal device Identification information of the slice that needs to perform slice authentication among the slices requested to be accessed;

The selection unit is configured to select a policy control network element according to the first NSSAI.
The apparatus according to claim 18, wherein the obtaining unit is configured to obtain a first policy associated with the first allowed NSSAI from the policy control network element.
The device according to claim 18 or 19, wherein the determining unit is further configured to determine a second allowed NSSAI after performing slice authentication on the slice corresponding to the pending NSSAI, and the second allowed NSSAI The NSSAI includes the identification information of the slice in the pending NSSAI that successfully performs slice authentication;

The device further includes an obtaining unit, configured to obtain a second policy associated with the second allowed NSSAI from the policy control network element.
The device according to claim 20, further comprising a sending unit, configured to send the second policy to the terminal device if the communication device cannot serve the second allowed NSSAI.
The device according to claim 18 or 19, wherein the determining unit is further configured to determine a second allowed NSSAI after performing slice authentication on the slice corresponding to the pending NSSAI, and the second allowed NSSAI The NSSAI includes the identification information of the slice in the pending NSSAI that successfully performs slice authentication;

The device further includes a setting unit, configured to set first indication information in the context of the terminal device if the communication device cannot serve the second allowed NSSAI, and the first indication information is used to indicate the second The mobility management network element obtains a policy from the policy control network element.
A communication device, characterized in that it comprises:

The acquiring unit is configured to acquire the context of the terminal device from the first mobility management network element, where the context of the terminal device includes identification information of the policy control network element and first indication information; and, according to the first indication information, from The policy control network element obtains the policy associated with the allowed NSSAI;

The determining unit is used to determine the allowed NSSAI.
The device according to claim 23, wherein the first indication information is used to instruct the communication device to obtain a policy from the policy control network element.
A communication device, characterized by comprising: a processor and an interface circuit, the interface circuit is used to communicate with other devices, and the processor is used to execute the method according to any one of claims 1-12.
A computer-readable storage medium, wherein the computer-readable storage medium stores a program, and when the program is called by a processor, the method according to any one of claims 1-12 is executed.
A computer program, wherein when the program is called by a processor, the method according to any one of claims 1-12 is executed.
A communication system, characterized by comprising: a mobility management network element and a policy control network element;

The mobility management network element is configured to determine the allowed network slice selection auxiliary information NSSAI after the first slice performs slice authentication, and the allowed NSSAI includes identification information of the slice that is allowed to be accessed by the terminal device. The first slice is the slice for which slice authentication needs to be performed among the slices that the terminal device requests to access; select the policy control network element according to the allowed NSSAI; and, obtain the data from the policy control network element. The first policy associated with the allowed NSSAI; wherein the mobility management network element serves the slice corresponding to the allowed NSSAI;

The policy control network element is used to send the first policy to the mobility management network element.
A communication system, characterized by comprising: a first mobility management network element and a policy control network element;

The first mobility management network element is used to determine a first NSSAI, where the first NSSAI includes a first allowed NSSAI and a pending NSSAI, or the first NSSAI includes a contracted NSSAI of a terminal device, and the pending NSSAI The NSSAI includes the identification information of the slice that needs to perform slice authentication among the slices that the terminal device requests to access; selects the policy control network element according to the first NSSAI; and, obtains it from the policy control network element The first policy associated with the first allowed NSSAI;

The policy control network element is configured to send the first policy to the first mobility management network element.
The system according to claim 29, wherein the system further comprises a second mobility management network element, configured to obtain the context of the terminal device from the first mobility management network element, and the terminal device The context includes the identification information of the policy control network element and the first indication information; determines the second allowed NSSAI; and, according to the first indication information, obtains the second allowed NSSAI from the policy control network element The second strategy associated with NSSAI.