WO2020063971A1

WO2020063971A1 - Pcf+pcrf selection method, amf, bsf and storage medium

Info

Publication number: WO2020063971A1
Application number: PCT/CN2019/109086
Authority: WO
Inventors: 吴中华; 刘俊羿
Original assignee: 中兴通讯股份有限公司
Priority date: 2018-09-29
Filing date: 2019-09-29
Publication date: 2020-04-02
Also published as: CN110972090B; CN110972090A

Abstract

Disclosed in the embodiments of the present invention are a PCF+PCRF selection method, an AMF, a BSF and a storage medium, belonging to the field of communications. The method comprises: when an AMF detects that UE is switched from 4G to 5G, querying from a BSF the PCF+PCRF selected by an SMF+PGW-C for the UE; requesting access and mobility policy control from the selected PCF+PCRF. In the embodiments of the present invention, the PCF+PCRF selected by the SMF+PGW-C for the UE in 4G access is queried from newly-introduced BSF of 5G, and the access and mobility policy control are requested from the selected PCF+PCRF, so that when the UE is switched from 4G to 5G, the AMF is able to select the PCF+PCRF that the SMF+PGW-C has selected when 4G is accessed, thus satisfying the association of the application scenario that the PCF+PCRF needs to associate with the policy controls of the AMF and the SMF+PGW-C.

Description

PCF + PCRF selection method, AMF, BSF and storage medium

This application claims priority from Chinese patent application CN201811150261.6 entitled "PCF + PCRF selection method, AMF, BSF, and storage medium" filed on September 29, 2018, the entire contents of which are incorporated herein by reference.

Technical field

The present invention relates to the field of communication technologies, and in particular, to a PCF + PCRF selection method, AMF, BSF, and storage medium based on a 4 / 5G mutual switching scenario.

Background technique

With the development of communication technology, mobile communication networks are evolving from the fourth generation (4G for short) to the fifth generation (5G for short). However, 5G access network (NG-RAN, Next Generation Radio Access Network, next generation wireless access network) is still difficult to achieve full coverage, 5G access network and 4G access network E-UTRAN (Evolved Universal Terrestrial Radio Access Network, The evolved universal terrestrial radio access network) will coexist for a long time, and the UE (User Equipment) can support 5G and 4G access at the same time, and support smooth switching between these two access methods. To ensure service continuity when the UE switches access modes. Some network elements in the 4 / 5G core network need to be integrated and deployed, as shown in the architecture diagram of 4 / 5G in the non-roaming scenario shown in Figure 1, and the architecture diagram of 4 / 5G in the local grooming roaming scenario shown in Figure 2. , And the 4 / 5G architecture diagram in the hometown routing roaming scenario shown in Figure 3, some network elements that need to be deployed in the three scenarios include:

The HSS (Home Subscriber Server) of the 4G core network and the UDM (Unified Data Management) of the 5G core network are integrated and deployed. It is called Fusion HSS + UDM, which provides all external standard interfaces of HSS and UDM. There is internal interaction between the functional HSS part and the UDM part.

The 4G core network's PCRF (Policy & Charging Control Function) and the 5G core's PCF (Policy Control Function) are integrated and deployed, which is called PCF + PCRF (including V-PCF + V located in the visited network) -PCRF and H-PCF + H-PCRF located in the home network).

The 4G core network's PGW-C (PDN Gateway Control Plane Packet Data Network Gateway Control Plane) and the 5G core network's SMF (Session Management Function, Session Management Function) are integrated and deployed, which is called SMF + PGW-C.

The PGW-U (PDN Gateway User Plane) of the 4G core network and the UPF (User Plan Function) of the 5G core network are integrated and deployed, which is called UPF + PGW-U.

4G's MME (Mobility Management Entity, Mobility Management Entity) and 5G's AMF (Access and Mobility Management Function, Access and Mobility Management Function) have similar functions and are responsible for UE access and mobility management. The UE needs to register with the MME or AMF before establishing a session on the PGW-C or SMF.

5G AMF can request non-session management related control policies from the PCF when the UE registers or switches to the AMF, including AMRP (Access and Mobility related Policy) that needs to be executed by the AMF, and notify the AMF It is transparently transmitted to the UE's URP (UE Routing Selection Policy) and ANDSP (Access Network Discovery and Selection Policy) implemented by the UE. In contrast, the 4G MME does not have the function of obtaining the control strategy from the PCRF.

When the PGW-C or SMF receives a session establishment request from the UE, the PGW-C or SMF can request a control policy for the session from the PCRF or PCF, which is used to implement QoS (Quality Control), charging for the session Control (Charging, Control), flow steering control (Traffic Steering, Control), usage monitoring (Usage, Monitoring) and so on.

Multiple PCFs can be deployed in a 5G core network. The AMF can configure each PCF address and selection method locally, or discover the PCF through NRF (Network Repository Function, Network Warehouse Function), which requires each PCF to first identify itself, The address and selection method are registered with the NRF.

In a 4G network, the PGW-C can configure the PCRF address and selection method locally, or send a request to a DRA (Diameter Routing Agent). Among them, Diameter is an authentication, authorization and accounting protocol. The interface between PCRF and PGW-C uses messages based on the Diameter protocol. The DRA can forward messages based on the Diameter protocol, and the DRA selects the PCRF. In a 5G network, the SMF can configure the PCRF address and selection method locally, or discover the PCF through NRF. The AMF can also tell the SMF that the AMF selects the PCF selected for a UE, and then the SMF selects the same PCF for the session.

In addition, the AMF can save the selected PCF identity in the local UE context. When the UE moves between 5G access networks, the AMF may switch. The new AMF obtains the UE context from the old AMF, so that the same PCF can be selected.

For a UE, if there is no correlation between its non-session management related policies and session management related policies, AMF and SMF can choose different PCFs. However, if there is correlation, if AMF and SMF do not choose the same PCF, it is difficult to achieve non-session management related policies and session management related policies. For example, the PCF requires the SMF to monitor usage of the session, and notify the PCF when the usage reaches a set threshold, and the PCF adjusts the access and mobility related policies issued to the AMF accordingly. For another example, the PCF adjusts the session QoS control of the SMF according to the user location reported by the AMF, and there is an association between the non-session management related policies and the session management related policies.

In order to ensure that the AMF and the SMF select the same PCF, the prior art defines a method for the AMF to pass the selected PCF identity to the SMF during 5G access. In order to ensure that the new and old AMFs can select the same PCF when the AMF is switched, the existing technology defines a method in which the new AMF can obtain the selected PCF identity from the old AMF when the AMF is switched. However, before the UE switches from 4G access to 5G cut-in, SMF + PGW-C has selected a PCF + PCRF for the UE session. At this time, the AMF after the switch may be requested to select the same PCF + PCRF, but due to the MME There is no need to interact with PCF + PCRF. AMF cannot obtain the selected PCF + PCRF from the UE context provided by the MME. This may cause AMF to select a different PCF + PCRF, and further cause PCF + PCRF to control AMF's policy and control the AMF. The policy control of SMF + PGW-C cannot be related.

As shown in Figure 4, the 5G core network introduces BSF (Binding Support Function), which is used for AF (Application Function) addressing PCF. When the SMF requests policy control from the PCF for the session requested by the UE, the PCF is provided with the UE's user ID, user IP address, and other information. The PCF registers the binding information (user ID, user IP address, and selected PCF ID) with the BSF. . Then the UE accesses services on the AF through this session. The AF may need to request policy authorization from the PCF for the services accessed by the UE. The PCF selected by AF for this policy authorization must be consistent with the PCF selected by SMF for this session, because this policy authorization is generally It will trigger the PCF to adjust the policy control for the associated session of the SMF. The AF can query the corresponding PCF from the BSF according to the user IP address or user ID, and then request policy authorization directly from the AF through the N5 interface defined by 5G. In the 4G core network, the AF also needs to address the PCRF, but different technologies are used. Both the PGW and the AF pass the initial request message to the PCRF to the DRA, and the DRA addresses the same PCRF. In the 4G core network, the interface between PCRF and AF is an Rx interface, and the interface between PGW and GGW is an interface based on the Diameter protocol. In the 5G core network, the interface between PCF and AF is an N5 interface, and The interfaces between SMFs are N7 interfaces, both of which are service-based interfaces based on HTTP. In a 4 / 5G interoperable converged core network, PCF + PCRF must support both the Rx interface and the N5 interface, because the UE may access the stock AF (only the Rx interface is supported), or it may access the new AF (support N5 Interface), for this purpose, the stock DRA can be upgraded so that when receiving the Rx interface request message of stock AF, it can query the BSF, address to the correct PCF + PCRF, or introduce BSF + DRA to replace the stock DRA. However, the prior art does not consider that the BSF provides the addressing PCF function to the AMF, so it still cannot solve the problem that the AMF may not be able to select the PCF + PCRF selected by SMF + PGW-C when switching from 4G to 5G.

Summary of the Invention

In view of this, the purpose of the present invention is to provide a PCF + PCRF selection method, AMF, BSF, and storage medium, so as to solve that the UE cannot access the same PCF + PCRF after switching from 4G access to 5G handover, resulting in PCF + Technical issues that cannot be related to the strategic control of PCRF on AMF and SMF + PGW-C.

The technical solutions adopted by the embodiments of the present invention to solve the above technical problems are as follows:

According to one aspect of the embodiments of the present invention, a PCF + PCRF selection method is provided, which is applied to AMF. The method includes:

When the AMF detects that the UE switches from 4G to 5G, it queries the BSF for the PCF + PCRF selected by the SMF + PGW-C for the UE;

Request access and mobility policy control from the selected PCF + PCRF.

According to another aspect of the embodiments of the present invention, a method for selecting PCF + PCRF is provided, which is applied to BSF. The method includes:

Receive the PCF + PCRF registration binding information request, and store the binding information of the UE;

Receive the AMF query request for the PCF + PCRF selected for the UE, and feedback the PCF + PCRF selected for the UE to the AMF;

The binding information of the UE includes a user identifier of the UE, a user IP address, and a PCF + PCRF identifier selected for the UE.

According to still another aspect of the embodiments of the present invention, an AMF is provided. The AMF includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the computer program is executed by the processor, the PCF is implemented. + PCRF selection method steps.

According to still another aspect of the embodiments of the present invention, a BSF is provided. The BSF includes a memory, a processor, and a computer program stored on the memory and executable on the processor. The BSF is characterized in that, when the computer program is executed by the processor, To realize the steps of implementing the PCF + PCRF selection method described above.

According to yet another aspect of the embodiments of the present invention, a storage medium is provided. The storage medium stores a computer program, and when the computer program is executed by a processor, implements the steps of the PCF + PCRF selection method described above applied to AMF, and / Alternatively, the steps of the PCF + PCRF selection method applied to the BSF described above may be implemented.

The PCF + PCRF selection method, AMF, BSF, and storage medium provided in the embodiments of the present invention select SMF + PGW-C for 4G access in the newly introduced BSF from 5G to select the PCF + PCRF for the UE, and select the selected PCF + PCRF requests access and mobility policy control, so that when the UE switches from 4G to 5G, the AMF can select the PCF + PCRF that SMF + PGW-C has selected during 4G access, so that the PCF + PCRF controls the AMF policy and controls SMF + PGW-C's policy control needs to be associated with the associated application scenarios.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a 4 / 5G architecture diagram in a non-roaming scenario in the related art according to an embodiment of the present invention;

FIG. 2 is an architecture diagram of 4 / 5G in a local grooming roaming scenario in the related art according to an embodiment of the present invention; FIG.

FIG. 3 is an architecture diagram of a hometown routing roaming scenario 4 / 5G in the related art according to an embodiment of the present invention; FIG.

FIG. 4 is an architecture diagram of the interworking between BSF and DRA in 4 / 5G interoperation in related technology according to an embodiment of the present invention; FIG.

FIG. 5 is a flowchart of a PCF + PCRF selection method applied to AMF provided in Embodiment 1 of the present invention; FIG.

FIG. 6 is a flowchart of a PCF + PCRF selection method applied to BSF according to Embodiment 2 of the present invention; FIG.

7 is a flowchart of a method for selecting a PCF + PCRF in a non-roaming scenario according to Embodiment 3 of the present invention;

8 is a flowchart of a method for selecting a PCF + PCRF in a local grooming roaming scenario according to a fourth embodiment of the present invention;

FIG. 9 is a flowchart of a method for selecting a PCF + PCRF in a hometown routing roaming scenario provided in Embodiment 5 of the present invention.

The realization of the purpose, functional characteristics and advantages of the present invention will be further explained with reference to the embodiments and the drawings.

detailed description

In order to make the technical problems, technical solutions and beneficial effects to be more clearly understood by the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not intended to limit the present invention.

Example one

As shown in FIG. 5, a PCF + PCRF selection method provided by an embodiment of the present invention is applied to AMF, and the method includes:

S501. When the AMF detects that the UE switches from 4G to 5G, it queries the BSF for the PCF + PCRF selected by the SMF + PGW-C for the UE.

S502. Request access and mobility policy control from the selected PCF + PCRF.

Specifically, please refer to FIG. 1 and FIG. 4. In a non-roaming scenario, the AMF queries the H-BSF located in the home network for SMF + PGW-C for the H-PCF + H-PCRF selected by the UE and the selected H. -PCF + H-PCRF request access and mobility policy control.

Please refer to Figure 2 and Figure 4. In the local grooming roaming scenario, the AMF queries the V-BSF located in the visited network for the V-PCF + V-PCRF selected by the SMF + PGW-C for the UE and the V-PCF selected for the UE. + V-PCRF request access and mobility policy control, H-PCRF + H-PCF is selected by the selected V-PCF + V-PCRF, and V-PCF + V-PCRF is sent to the selected H- PCRF + H-PCF requests access and mobility policy control.

Please refer to Figure 2 and Figure 4. In the hometown routing roaming scenario, the AMF queries the H-BSF in the home network for the H-PCRF + H-PCF selected by the SMF + PGW-C for the UE and selects V-PCF + V -PCRF, tells the selected H-PCRF + H-PCF to the selected V-PCF + V-PCRF, and the selected V-PCF + V-PCRF requests access to the selected H-PCRF + H-PCF and Mobility policy control.

Example two

As shown in FIG. 6, a PCF + PCRF selection method provided by an embodiment of the present invention is applied to BSF, and the method includes:

S601. Receive a registration binding information request of the PCF + PCRF, and store the binding information of the UE.

The binding information of the UE includes the user identity of the UE, the user IP address, and the PCF + PCRF selected for the UE (including H-PCF + H-PCRF located in the home network or V-PCF + V located in the visited network). -PCRF).

Specifically, please refer to FIGS. 1 and 4. In the non-roaming mode, SMF + PGW-C, PCF + PCRF (ie, H-PCF + H-PCRF), and BSF (ie, H-BSF) are located in the home network. The H-BSF located in the home network receives the registration binding information request sent by the H-PCF + H-PCRF, and stores the user identifier of the UE, the user IP address, and the H-PCF + H-PCRF identifier selected for the UE.

Please participate in Figures 2 and 4. In the local grooming roaming mode, SMF + PGW-C is visiting the network. SMF + PGW-C chooses PCF + PCRF (that is, V-PCF + V-PCRF) and V-PCF located in the visited network. + V-PCRF registers the binding information to the BSF (ie, V-BSF) located in the visited network, the V-BSF UE's user identity, user IP address, and selected V-PCF + V-PCRF identity). V-PCF + V-PCRF further selects H-PCF + H-PCRF located in the home network.

Specifically, please refer to FIGS. 3 and 4. In the hometown routing roaming mode, SMF + PGW-C, PCF + PCRF (ie, H-PCF + H-PCRF), and BSF (ie, H-BSF) are located in the home network. The H-BSF located in the home network receives the registration binding information request sent by the H-PCF + H-PCRF, and stores the user identifier of the UE, the user IP address, and the H-PCF + H-PCRF identifier selected for the UE.

S602. Receive a request for the AMF to query the PCF + PCRF selected for the UE, and feed back the PCF + PCRF selected for the UE to the AMF.

Specifically, in the non-roaming mode, the H-BSF located in the home network receives an AMF query request for the H-PCF + H-PCRF selected for the UE, and feeds back to the AMF the H-PCF + H-PCRF selected for the UE. Identification

In the local grooming roaming mode, the V-BSF located in the visited network receives the AMF query request for the V-PCF + V-PCRF selected for the UE, and feeds back the AMF selected V-PCF + V-PCRF identification for the UE.

In the hometown roaming mode, the H-BSF located in the home network receives an AMF query request for the H-PCF + H-PCRF selected for the UE, and feeds back the AMF identification of the H-PCF + H-PCRF selected for the UE.

Example three

As shown in FIG. 7, an embodiment of the present invention provides a method for selecting a PCF + PCRF in a non-roaming scenario. The method includes:

S701. The UE requests the SMF + PGW-C to access the home network through 4G to establish a session.

S702, SMF + PGW-C selects H-PCF + H-PCRF of the home network, and requests session policy control from the selected H-PCF + H-PCRF;

S703. The H-PCF + H-PCRF registers binding information with the H-BSF of the home network.

S704. The UE switches from 4G access to 5G access.

S705. The AMF queries the H-BSF of the home network for the selected H-PCF + H-PCRF of SMF + PGW-C.

S706. The AMF selects H-PCF + H-PCRF according to the query result returned by the H-BSF, and requests access and mobility policy control from the selected H-PCF + H-PCRF.

Embodiment 4

As shown in FIG. 8, an embodiment of the present invention provides a method for selecting a PCF + PCRF in a local grooming roaming scenario. The method includes:

S801. The UE requests the SMF + PGW-C of the visited network to establish a session through 4G access.

S802, SMF + PGW-C selects V-PCF + V-PCRF, and requests session policy control from the selected V-PCF + V-PCRF;

S803, V-PCF + V-PCRF selects H-PCF + H-PCRF and negotiates session policy control;

S804, V-PCF + V-PCRF registers binding information with the BSF of the visited network;

S805. The UE switches from 4G access to 5G access.

S806. The AMF inquires the BSF of the visited network of the V-PCF + V-PCRF selected by SMF + PGW-C;

S807. The AMF selects V-PCF + V-PCRF according to the query result returned by the BSF, and requests access and mobility policy control from the selected V-PCF + V-PCRF.

S808. V-PCF + V-PCRF selects H-PCF + H-PCRF, and requests access and mobility policy control from the selected H-PCF + H-PCRF.

Example 5

As shown in FIG. 9, FIG. 9 is a method for selecting a PCF + PCRF in a hometown routing roaming scenario according to an embodiment of the present invention. The method includes:

S901. The UE requests the SMF + PGW-C of the home network to establish a session through 4G access.

S902, SMF + PGW-C selects PCF + PCRF of the home network, and requests session policy control from the selected H-PCF + H-PCRF;

S903, H-PCF + H-PCRF registers binding information with the BSF of the home network;

S904. The UE switches from 4G access to 5G access.

S905. The AMF inquires the BSF of the visited network about the selected H-PCF + H-PCRF of SMF + PGW-C;

S906. The AMF selects V-PCF + V-PCRF by itself, and requests access and mobility policy control from the selected V-PCF + V-PCRF, while providing the selected H to the selected V-PCF + V-PCRF. -PCF + H-PCRF identification;

S907. The V-PCF + V-PCRF requests access and mobility policy control from the H-PCF + H-PCRF selected by the AMF.

Example Six

An embodiment of the present invention provides an AMF. The AMF includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the computer program is executed by the processor, the PCF + PCRF that implements the foregoing method embodiment is implemented. Select the method steps.

It should be noted that the AMF of this embodiment belongs to the same concept as the embodiment of the PCF + PCRF selection method. The specific implementation process is described in detail in the method embodiment, and the technical features in the method embodiment are correspondingly applicable in this embodiment. I won't repeat them here.

Example Seven

An embodiment of the present invention provides a BSF. The BDF includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the computer program is executed by the processor, the PCF + PCRF that implements the foregoing method embodiment is implemented. Select the method steps.

It should be noted that the BSF of this embodiment belongs to the same concept as the above-mentioned embodiment of the PCF + PCRF selection method, and its specific implementation process is detailed in the method embodiment, and the technical features in the method embodiment are correspondingly applicable in this embodiment I wo n’t repeat them here.

Example Nine

An embodiment of the present invention also provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, the PCF + of any of the first to fifth embodiments is implemented. Steps of the PCRF selection method.

It should be noted that the computer-readable storage medium of the embodiment of the present invention belongs to the same concept as the embodiment of the PCF + PCRF selection method, and its specific implementation process is detailed in the method embodiment, and the technical features in the method embodiment are computer-readable Corresponding applications are applicable in the storage medium, and are not repeated here.

The PCF + PCRF selection method, AMF, BSF, and storage medium provided in the embodiments of the present invention select SMF + PGW-C for 4G access in the newly introduced BSF from 5G to select the PCF + PCRF for the UE, and send the selected PCF to the selected PCF + PCRF requests access and mobility policy control, so that when the UE switches from 4G to 5G, the AMF can select the PCF + PCRF that SMF + PGW-C has selected during 4G access, so that the PCF + PCRF controls the AMF policy and controls SMF + PGW-C's policy control needs to be associated with the associated application scenarios.

Those of ordinary skill in the art can understand that all or some of the steps, systems, and functional modules / units in the devices disclosed in the methods above can be implemented as software, firmware, hardware, and their appropriate pooling.

In the hardware implementation, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of the physical poolware; for example, a physical poolware may have multiple functions, or a function or step may be composed of Several physical poolware are implemented in cooperation. Some or all physical pools can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as a dedicated application integrated circuit. Such software may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As is known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile implemented in any method or technology used to store information such as computer-readable instructions, data structures, program modules or other data. Removable, removable and non-removable media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or may Any other medium used to store desired information and which can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that a communication medium typically contains computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and may include any information delivery medium .

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, without thereby limiting the scope of rights of the present invention. Any modification, equivalent replacement, and improvement made by those skilled in the art without departing from the scope and substance of the present invention shall fall within the scope of the rights of the present invention.

Claims

A PCF + PCRF selection method applied to AMF, wherein the method includes:

When the access and mobility management function AMF detects that the user equipment UE switches from 4G to 5G, it queries the binding support function BSF for the fusion session management function and the packet data network gateway control plane SMF + PGW-C to select the UE for the UE. Integrated policy control function and policy and charging rules function PCF + PCRF;

Request access and mobility policy control to the selected PCF + PCRF.
The method for selecting a PCF + PCRF according to claim 1, wherein the querying the BSF for the PCF + PCRF selected by the SMF + PGW-C for the UE, and requesting access and the PCF + PCRF for the selected PCF + PCRF. Mobility policy control, including:

In a non-roaming scenario, the AMF queries the H-BSF located in the home network for the H-PCF + H-PCRF selected by the SMF + PGW-C for the UE, and queries the selected H-PCF + H-PCRF request access and mobility policy control;

In the local grooming roaming scenario, the AMF queries the V-BSF located in the visited network to query the V-PCF + V-PCRF selected by the SMF + PGW-C for the UE, and to the selected V-PCF + V-PCRF request access and mobility policy control, H-PCRF + H-PCF is selected by the selected V-PCF + V-PCRF, and selected by the V-PCF + V-PCRF Fixed H-PCRF + H-PCF request access and mobility policy control;

In the hometown routing roaming scenario, the AMF queries the H-BSF located in the home network for the H-PCRF + H-PCF selected by the SMF + PGW-C for the UE, and selects V-PCF + V-PCRF To inform the selected H-PCRF + H-PCF of the selected V-PCF + V-PCRF to the selected H-PCRF + H-PCF from the selected V-PCF + V-PCRF Request access and mobility policy control.
The PCF + PCRF selection method according to claim 1, wherein before the AMF detects that the user equipment UE switches from 4G to 5G, the method further comprises:

When the UE accesses the 4G network, the SMF + PGW-C selects a PCF + PCRF for the UE;

Registering the binding information of the UE to a BSF by the selected PCF + PCRF;

The binding information of the UE includes a user identifier, a user IP address, and a PCF + PCRF identifier selected for the UE.
The PCF + PCRF selection method according to claim 3, wherein the SMF + PGW-C selects a PCF + PCRF for the UE, and the selected PCF + PCRF registers binding information of the UE to a BSF, These include:

In the non-roaming mode or the home routing roaming mode, the SMF + PGW-C selects the H-PCF + H-PCRF of the home network, and the H-PCF + H-PCRF of the home network binds the UE's binding information Register to H-BSF;

In the local grooming roaming mode, the SMF + PGW-C selects V-PCF + V-PCRF located in the visited network, and the V-PCF + V-PCRF registers the binding information of the UE to V-PCF located in the visited network. BSF.
A method for selecting PCF + PCRF, wherein the method includes:

Receiving the PCF + PCRF registration binding information request, and storing the binding information of the UE;

Receiving an AMF query request for a PCF + PCRF selected for the UE, and feeding back to the AMF a PCF + PCRF selected for the UE;

The binding information of the UE includes a user identifier of the UE, a user IP address, and an identifier of a PCF + PCRF selected for the UE.
The method for selecting a PCF + PCRF according to claim 5, wherein the receiving the PCF + PCRF registration binding information request and storing the binding information of the UE specifically comprises:

In the non-roaming mode or the home routing roaming mode, the H-BSF located in the home network receives the registration binding information request sent by the H-PCF + H-PCRF, stores the user identifier, the user IP address, and the address of the UE. The identifier of the H-PCF + H-PCRF selected by the UE;

In the local grooming roaming mode, the V-BSF located in the visited network receives the registration binding information request sent by the V-PCF + V-PCRF located in the visited network, and stores the user identifier, the user IP address, and a selection address for the UE. V-PCF + V-PCRF identification.
The method for selecting a PCF + PCRF according to claim 5, wherein the receiving an AMF query request for a PCF + PCRF selected for the UE, and feeding back to the AMF a PCF + PCRF selected for the UE, These include:

In a non-roaming mode or a home roaming mode, the H-BSF located in the home network receives an AMF query request for the H-PCF + H-PCRF selected for the UE, and feeds back to the AMF the request selected for the UE. H-PCF + H-PCRF identification;

In the local grooming roaming mode, the V-BSF located in the visited network receives an AMF query request for the V-PCF + V-PCRF selected for the UE, and feeds back to the AMF the V-PCF + V selected for the UE. -PCRF identification.
An AMF comprising a memory, a processor, and a computer program stored on the memory and operable on the processor, wherein when the computer program is executed by the processor, the claims are implemented Steps of the PCF + PCRF selection method described in 1 to 4.
A BSF includes a memory, a processor, and a computer program stored on the memory and operable on the processor, wherein the computer program is implemented as a right when executed by the processor. The steps of the PCF + PCRF selection method described in 5 to 7 are required.
A storage medium, wherein a computer program is stored on the storage medium, and when the computer program is executed by a processor, implements the steps of the PCF + PCRF selection method according to any one of claims 1 to 4. Or the steps of implementing the PCF + PCRF selection method according to any one of claims 5 to 7.