Addressing method of policy control network element, application function network element and control plane network element

Abstract

The invention discloses an addressing method of a policy control network element, an application function network element and a control plane network element, and the method comprises the steps that the application function network element determines PCC policy control of a user terminal after the control plane network element establishes a service channel for the user terminal; in an establishment process of a service channel, when a plurality of user plane network elements controlled by the same control plane network element multiplex a user IP address, device identifiers of N control plane network elements configured by the control plane network element respectively correspond to N multiplexed user IP address pools; acquiring an address of a control plane network element; sending an address query request of the policy control network element to the corresponding control plane network element according to the address of the control plane network element; and receiving a query result of the address of the policy control network element sent by the control plane network element. By adopting the technical scheme of the invention, the waste of software and hardware resources of the policy control network element and the control plane network element / policy binding network element is avoided, and the complexity of operation and maintenance of the policy control network element is not increased.

Description

Technical Field

[0001] The present invention relates to the field of mobile communication technology, and in particular to an addressing method for a policy control network element, an application function network element, a control plane network element and a computer-readable storage medium. Background Art

[0002] In the mobile communication network architecture, the network establishes a PDU session / bearer channel (called "PDU session" in 5G and "bearer" in 4G) between the UE and the data network (DN) for the user terminal, so that the user can complete end-to-end communication. Under the current PCC architecture, when the application function network element (such as AF, NEF, SCEF, AAC) initiates a policy application (such as QoS acceleration, third-party billing, etc.), the policy application message is sent to the policy control network element (such as PCF, PCRF) related to the PDU session / bearer. After receiving the policy application message from the application function network element, the policy control network element associates the policy application initiated by the application function network element with the corresponding existing PDU session / bearer (that is, the corresponding existing user service data flow), and issues the relevant PCC management and control policy (that is, the corresponding PCC rules).

[0003] In the business process provided by the existing technical solution, in the PCC process of establishing the UE's PDU session / bearer, the PCF will initiate a registration process to the BSF, and it is necessary to create "binding information" with the BSF, and update / delete the "binding information" in the subsequent business process. Therefore, the PCF needs to configure additional processing resources, and whether the BSF is set up independently or in combination with other network elements, it is necessary to configure resources for saving the "binding information" and processing resources for creating / updating / deleting the "binding information", thereby causing a waste of software and hardware resources of the PCF and BSF. At the same time, for the situation where the UE undergoes IP address conversion when accessing an external IP network, the PCF needs to provide the "domain" corresponding to the IPv4 private address in the "binding information". In order to meet the user roaming scenario, the PCF needs to configure the IP domain data of the IPv4 private address of the entire network of this operator, thereby increasing the complexity of the operation and maintenance of the PCF. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide an addressing method for a policy control network element, an application function network element, a control plane network element and a computer-readable storage medium, which does not require additional processing power of the policy control network element, nor does it require additional processing power and storage resources of the control plane network element / policy binding network element, thereby avoiding waste of software and hardware resources of the policy control network element and the control plane network element / policy binding network element, and the policy control network element does not require additional data configuration, thereby not increasing the complexity of the operation and maintenance of the policy control network element.

[0005] In order to achieve the above-mentioned object, an embodiment of a first aspect of the present invention provides an addressing method of a policy control network element, which is applied to an application function network element, including:

[0006] After the control plane network element establishes a service channel for a user terminal accessing the mobile communication network, the PCC policy control to be executed on the user terminal is determined; wherein, during the establishment of the service channel, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of N control plane network elements configured by the control plane network element correspond to N reused user IP address pools respectively, and N>1;

[0007] Obtain the address of the control plane network element currently responsible for the user terminal service;

[0008] Send an address query request for the policy control network element currently responsible for the PCC policy control of the service channel of the user terminal service to the corresponding control plane network element according to the address of the control plane network element;

[0009] Receive the query result of the address of the policy control network element sent by the control plane network element.

[0010] Furthermore, the method further comprises:

[0011] According to the address of the policy control network element obtained from the query result, a policy application request is sent to the policy control network element; wherein the policy application request includes the IP address of the user terminal assigned by the control plane network element, the device identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0012] Further, the obtaining the address of the control plane network element currently responsible for the user terminal service includes:

[0013] By configuring local static data, configuring the local configuration information to a mapping table of the device address of the control plane network element; wherein the local configuration information includes the IP address of the user terminal assigned by the control plane network element, the IP address of the user terminal after address conversion, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal;

[0014] The mapping table of the device address of the control plane network element is queried according to the local configuration information to obtain the address of the control plane network element currently responsible for the user terminal service.

[0015] Further, the obtaining the address of the control plane network element currently responsible for the user terminal service includes:

[0016] Obtaining service discovery query parameters; wherein the service discovery query parameters include the IP address of the user terminal assigned by the control plane network element, the mobile communication network access external network identifier corresponding to the service channel of the user terminal, and the domain name to which the IP address derived from the IP address of the user terminal after address conversion belongs;

[0017] Execute the control plane network element service discovery process to the network storage function according to the service discovery query parameter; wherein the registration information of the control plane network element to the network storage function includes the address of the control plane network element and the local device addressing identifier;

[0018] Receiving a service discovery response message sent by the network storage function based on the registration information, and acquiring an address of a control plane network element according to the service discovery response message;

[0019] Then, the address query request includes the IP address of the user terminal allocated by the control plane network element, the local device addressing identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0020] Further, the obtaining the address of the control plane network element currently responsible for the user terminal service includes:

[0021] By configuring local static data, configuring the local configuration information to a mapping table of the device address of the control plane network element; wherein the local configuration information includes the IP address of the user terminal assigned by the control plane network element, the IP address of the user terminal after address conversion, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal;

[0022] Query the mapping table of the device address of the control plane network element according to the local configuration information to obtain the address of the control plane network element currently responsible for the user terminal service and the local device addressing identifier;

[0023] Then, the address query request includes the IP address of the user terminal allocated by the control plane network element, the local device addressing identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0024] In order to achieve the above object, a second aspect of the present invention provides an addressing method for a policy control network element, which is applied to a control plane network element, including:

[0025] After the user terminal accesses the mobile communication network, a user IP address is allocated to the user terminal, and a PCC process is initiated to the policy control network element with a device identifier of the control plane network element used for the interface with the policy control network element corresponding to the user IP address pool; wherein, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools respectively, and N>1;

[0026] Receive the PCC policy rules issued by the policy control network element, and save the PCC policy session associated information of the service channel of the user terminal; wherein the information includes the device identification of the control plane network element, the user IP address, the mobile communication network access external network identification and the device identification of the policy control network element and the binding data therebetween;

[0027] After the application function network element obtains the address of the control plane network element, it receives an address query request for the policy control network element for the service channel PCC policy control currently responsible for the user terminal service sent by the application function network element;

[0028] querying the binding data according to the address query request to obtain the address of the policy control network element;

[0029] The query result of the address of the policy control network element is sent to the application function network element.

[0030] Furthermore, the method further comprises:

[0031] Receive the PCC control policy issued by the policy control network element and execute the PCC control policy; wherein the PCC control policy is a PCC rule policy executed by the policy control network element on the service channel of the user terminal after receiving the policy application request sent by the application function network element, and the policy application request includes the IP address of the user terminal assigned by the control plane network element, the device identifier of the control plane network element and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0032] In order to achieve the above-mentioned object, an embodiment of the third aspect of the present invention further provides an application function network element, which is used to implement the addressing method of the policy control network element described in any one of the first aspects above, and the application function network element includes:

[0033] A PCC policy control determination module is used to determine the PCC policy control to be executed on the user terminal after the control plane network element establishes a service channel for the user terminal accessing the mobile communication network; wherein, during the establishment of the service channel, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools respectively, and N>1;

[0034] A first address acquisition module, used to acquire the address of the control plane network element currently responsible for the user terminal service;

[0035] A first sending module is used to send an address query request for a policy control network element currently responsible for the service channel PCC policy control of the user terminal service to the corresponding control plane network element according to the address of the control plane network element;

[0036] The first receiving module is used to receive the query result of the address of the policy control network element sent by the control plane network element.

[0037] In order to achieve the above-mentioned object, an embodiment of the fourth aspect of the present invention further provides a control plane network element, which is used to implement the addressing method of the policy control network element according to any one of the second aspects above, and the control plane network element includes:

[0038] The PCC process initiation module is used to allocate a user IP address to the user terminal after the user terminal accesses the mobile communication network, and initiate the PCC process to the policy control network element with the device identifier of the control plane network element used for the interface between the policy control network element corresponding to the user IP address pool; wherein, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools respectively, and N>1;

[0039] A PCC association information storage module is used to receive the PCC policy rules issued by the policy control network element, and save the PCC policy session association information of the service channel of the user terminal; wherein the information includes the device identification of the control plane network element, the user IP address, the mobile communication network access external network identification and the device identification of the policy control network element and the binding data therebetween;

[0040] A first receiving module is used to receive an address query request for a policy control network element for a service channel PCC policy control currently responsible for user terminal services, sent by the application function network element after the application function network element obtains the address of the control plane network element;

[0041] A first address acquisition module, configured to query the binding data according to the address query request to obtain the address of the policy control network element;

[0042] The first sending module is used to send the query result of the address of the policy control network element to the application function network element.

[0043] The fifth aspect embodiment of the present invention also provides a computer-readable storage medium, which includes a stored computer program; wherein, when the computer program is running, it controls the device where the computer-readable storage medium is located to execute the addressing method of the policy-controlled network element described in any one of the first and second aspects above.

[0044] The sixth aspect embodiment of the present invention also provides an application function network element, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the addressing method of the policy control network element described in any one of the first aspects above when executing the computer program.

[0045] The seventh aspect embodiment of the present invention also provides a control plane network element, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the addressing method of the policy control network element as described in any one of the second aspects above when executing the computer program.

[0046] Compared with the prior art, an embodiment of the present invention provides an addressing method for a policy control network element, an application function network element, a control plane network element and a computer-readable storage medium. After the control plane network element establishes a service channel for a user terminal accessing a mobile communication network, the application function network element determines the PCC policy control to be executed on the user terminal, wherein, during the establishment of the service channel, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of N control plane network elements configured by the control plane network element correspond to N reused user IP address pools, N>1; the address of the control plane network element currently responsible for the user terminal service is obtained; according to the address of the control plane network element, an address query request for the policy control network element for the PCC policy control of the service channel currently responsible for the user terminal service is sent to the corresponding control plane network element; and the query result of the address of the policy control network element sent by the control plane network element is received. The embodiment of the present invention does not require additional processing power of the policy control network element, nor does it require additional processing power and storage resources of the control plane network element / policy binding network element, thereby avoiding waste of software and hardware resources of the policy control network element and the control plane network element / policy binding network element. In addition, the policy control network element does not require additional data configuration, and the complexity of the operation and maintenance of the policy control network element is not increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a PCC system architecture diagram provided by an embodiment of the present invention;

[0048] Figure 2 It is a flowchart of a preferred embodiment of a policy control network element addressing method provided by the first aspect of the present invention;

[0049] Figure 3 This is a business flow chart of a policy control network element addressing method provided by an embodiment of the present invention;

[0050] Figure 4It is a structural block diagram of a preferred embodiment of a policy control network element addressing method provided by the second aspect of the present invention;

[0051] Figure 5 is a structural block diagram of a preferred embodiment of an application function network element provided by the third aspect of the present invention;

[0052] Figure 6 It is a structural block diagram of a preferred embodiment of a control plane network element provided by the fourth aspect of the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this technical field without creative work are within the scope of protection of the present invention.

[0054] It should be noted that the meanings of all technical terms involved in the embodiments of the present invention are shown in Table 0:

[0055] Table 0 Technical term meaning table

[0056] Chinese meaning English full name Abbreviations Application Access Control Application Access Control AAC App Features Application Function AF Access and mobility management functions Access and Mobility Management Function AMF Access Point Name Access Point Name APN Session Binding Support Function Binding Support Function BSF Data Network Data Network DN Data Network Name Data Network Name DNN 4G base station Evolved Node B eNB 5G Base Station (Next) Generation NodeB gNB Internet Protocol Internet Protocol IP Internet Protocol Version 4 Internet Protocol version 4 IPv4 Internet Protocol Version 6 Internet Protocol version 6 IPv6 Mobility Management Entity Mobility Management Entity MME Network open function Network Exposure Function NEF Network storage function Network Repository Function NRF Policy Control and Charging Policy Control and Charging PCC Policy control function Policy Control Function PCF Policy and charging control functions Policy and Charging Control Function PCRF Protocol Data Unit Protocol Data Unit PDU Packet Data Network Gateway Packet Data Network Gateway PGW Service Quality Quality of Service QoS System Architecture Evolution-Gateway System Architecture Evolution Gateway SAE-GW Network capability exposure function Service Capability Exposure Function SCEF Service Gateway Serving Gateway SGW Session management features Session Management Function SMF Single network slice selection auxiliary information Single Network Slice Selection Assistance Information S-NSSAI User contract database Subscription Profile Repository SPR Subscription Persistent Identifier Subscription Permanent Identifier SUPI Unified data repository Unified Data Repository UDR User equipment / user terminal User Equipment UE User plane functions User Plane Function UPF

[0057] It should be noted that the main network elements involved in the prior art include policy control network elements (such as PCF, PCRF, PCF / PCRF), policy database network elements (such as UDR, SPR, UDR / SPR), service channel establishment control plane network elements (network functions: such as SMF, PGW-C (Packet Data Network Gateway Control Plane, packet data network gateway control plane), SMF / PGW-C), service channel establishment user plane network elements (network functions: such as UPF, PGW-U (Packet Data Network Gateway User Plane, packet data network gateway user plane), UPF / PGW-U), policy binding network elements (such as BSF), application function network elements (such as NEF, ACC, SCEF, AF, etc.) 6 categories, and application platforms, among which:

[0058] (1) Policy control network element (such as PCF, PCRF, PCF / PCRF): responsible for the control of PDU session / bearer policy, including the generation, modification and issuance of PCC policy. Usually, in order to improve the security and reliability of the network and the disaster recovery of network elements, policy control network elements are deployed in a group POOL manner, that is, multiple policy control network elements form a POOL. The policy control network elements in the same POOL are responsible for the PDU session / bearer PCC services of users in one (or more) number segments, or the services of all users in the same DNN / APN.

[0059] (2) Policy database network element (such as UDR, SPR, UDR / SPR): responsible for storing the PCC policy data signed by the user.

[0060] (3) Service channel establishment control plane network element (network function: such as SMF, PGW-C, SMF / PGW-C): Responsible for the establishment of PDU sessions / bearers for user terminals (i.e., UEs), including allocating IP addresses to user terminals UEs based on the information of the selected service channel establishment user plane network element (network function: such as UPF, PGW-U, UPF / PGW-U) (for example, the location of the service channel establishment user plane network element, the responsible user IP address segment, etc.), and responsible for executing the PCC policy for the corresponding PDU session / bearer issued by the policy control network element (such as PCF, PCRF, PCF / PCRF).

[0061] (4) Service channel establishment user plane network element (network function: such as UPF, PGW-U, UPF / PGW-U): Under the control of the service channel establishment control plane network element (network function: such as SMF, PGW-C, SMF / PGW-C), a user plane service channel connecting to the external IP network is established for the user terminal UE, and under the control of the service channel establishment control plane network element (network function: such as SMF, PGW-C / PCEF, SMF / PGW-C / PCEF), relevant PCC policies are executed.

[0062] (5) Policy binding network element (such as BSF): During the PDU session / bearer establishment / modification process of the user terminal UE, the policy binding network element (such as BSF) records the correspondence between the user terminal UE information (for example, user IP address, etc.) and the policy control network element (such as PCF, PCRF, PCF / PCRF), and is responsible for matching the corresponding policy control network element (such as PCF, PCRF, PCF / PCRF) in the process of the application function network element (such as NEF, AAC, SCEF, AF, etc.) addressing the policy control network element (such as PCF, PCRF, PCF / PCRF). The technical implementation of the policy binding network element (such as BSF) can be achieved in two ways. Method 1 is the technical implementation method standardized by 3GPP (3rd Generation Partnership Project) in the 5G SA (5G Standalone) network. Method 2 is the technical implementation method of China Mobile's existing network applied to 4G networks, 5G networks and 4G / 5G converged core networks, among which:

[0063] Mode 1: Independent BSF; in the process of establishing a service channel session for the user terminal UE, the SMF initiates the PCC process (N7 interface signaling process), and the PCF selected for the current PDU session of the user terminal UE sends the correspondence between the user terminal UE information (for example, user IP address, etc.) and the network element identifier (PCF ID) of this PCF and other information to the BSF; the BSF saves the correspondence between the user terminal UE information (for example, user IP address, etc.) and the PCF network element identifier (PCF ID) received from the selected PCF until the selected PCF instructs the BSF to cancel the correspondence between the user terminal information (for example, user IP address, etc.) and the PCF network element identifier (PCF ID); during this period, the BSF receives and updates the user terminal UE information update information (for example, user IP address change, etc.) sent by the selected PCF. When the application function network element (such as NEF, AAC, SCEF, AF, etc.) needs to send a policy application message (N5 / N30 interface signaling message), it first queries the independent BSF for the address of the corresponding PCF (i.e., the PCF selected in the N7 interface signaling process); the independent BSF provides the application function network element (such as NEF, AAC, SCEF, AF, etc.) with the address of the corresponding PCF (i.e., the PCF selected in the N7 interface signaling process) (PCF ID of the selected PCF, etc.) in the query response message, and then the application function network element (such as NEF, AAC, SCEF, AF, etc.) sends the policy application message (N5 / N30 interface signaling message) to the corresponding PCF (i.e., the PCF selected in the N7 interface signaling process). In actual network deployment, the independent BSF can be set up independently or in conjunction with network elements such as PCF, UDR, NRF, SMF, etc.

[0064] Method 2: The service channel establishes a control plane network element (network function: such as SMF, PGW, PGW-C, SMF / PGW-C) with built-in policy binding network element (such as BSF) function; among which, the BSF function can be a function possessed by SMF, PGW, PGW-C, SMF / PGW-C, or a logically independent logical function. In the process of establishing a service channel session for the user terminal UE, the service channel establishment control plane network element (network function: such as SMF, PGW, PGW-C, SMF / PGW-C) initiates the PCC process (N7 interface signaling process of 5G network and 4G / 5G converged core network, Gx interface signaling process of 4G network), and saves the policy control network element identifier (PCF ID of 5G network, PCRFID of 4G network, PCF / PCRFID of 4G / 5G converged core network) selected for this PDU session / bearer of the user terminal UE, that is, which policy control network element (PCF of 5G network, PCRF of 4G network, PCF / PCRFID of 4G / 5G converged core network) is currently responsible for the PCC policy control of this PDU session / bearer of this user terminal UE until the PDU session / bearer of the user terminal UE ends (deletes). When the application function network element (such as NEF, AAC, SCEF, AF, etc.) needs to send a policy application message (N5 / N30 interface signaling message of 5G network and 4G / 5G converged core network, Rx interface signaling message of 4G network), it first queries the BSF function built into the control plane network element (network function: such as SMF, PGW, PGW-C, SMF / PGW-C) of the service channel to query the policy control network element identifier (PCF of 5G network). The BSF function matches the information (for example, user IP address information) contained in the query request message of the application function network element (such as NEF, AAC, SCEF, AF, etc.) to the address (PCFID of the 5G selected PCF, PCRFID of the 4G selected PCRF, PCRF of the 4G / 5G selected PCF) of the corresponding policy control network element (that is, the PCF selected in the signaling process of the N7 interface of the 5G network and the 4G / 5G converged core network, and the PCRF selected in the signaling process of the Gx interface of the 4G network) The PCF / PCRFID of PCF / PCRF, etc.) is returned to the application function network element that initiated the query request (such as NEF, AAC, SCEF, AF, etc.), and then the application function network element (such as NEF, AAC, SCEF, AF, etc.) sends the policy request message (N5 / N30 interface signaling message of 5G network and 4G / 5G converged core network, Rx interface signaling message of 4G network) to the corresponding policy control network element (ie: PCF selected in the N7 interface signaling process of 5G network and 4G / 5G converged core network, PCRF selected in the Gx interface signaling process of 4G network).

[0065] (6) Application function network elements (such as NEF, ACC, SCEF, AF, etc.): The platform that initiates the PCC dynamic policy control service request can be the operator's own service platform (NEF, AAC, SCEF, capability exposure platform, VoLTE SBC (Session Border Controller) and other AFs, etc.), or a third-party Internet ICP (Internet Content Provider) application platform (such as Tencent server, etc.).

[0066] The relevant business processes in the prior art include:

[0067] (1) 4G service scenarios and 2G / 3G service scenarios

[0068] The 3GPP international standard does not regulate the BSF function in 4G and 2G / 3G business scenarios. China Mobile has adopted a customized solution, namely: PGW and PGW-C (Note: PGW-C+PGW-U completes the function of PGW, PGW-C+PGW-U can be called distributed PGW) have built-in BSF function; among them, PGW and PGW-C+PGW-U can simultaneously have the function of 2G / 3GGGSN (Gateway GPRS Support Node) to meet 2G / 3G business scenarios; the following business process only describes the 4G business scenario as an example, the specific business process is as follows:

[0069] Step 1. The user terminal UE accesses the core network MME through the LTE (Long Term Evolution, 3GPP long-term evolution) wireless network. In the process of establishing a bearer for the user terminal UE, the PGW / PGW-C allocates an IPv4 private address and / or an IPv6 address to the user terminal UE for the user terminal UE to access the external IP network; and the PGW / PGW-C initiates a PCC process, addresses the corresponding PCRF directly or through the Diameter signaling network, and the Gx interface signaling message sent by the PGW / PGW-C to the PCRF includes: the user IP address (IPv4 private address and / or IPv6 address), APN, PGW / PGW-C device identification (PGW / PGW-C) allocated to the user terminal UE by the PGW / PGW-C After receiving the response message returned by PCRF (directly or through Diameter signaling network), the BSF function built into PGW / PGW-C records and saves the address of PCRF in the response (PCRFID), which is the device identifier of PCRF responsible for the PCC policy control of this user terminal UE (that is, the mapping relationship (binding information) between the current bearer of the user terminal UE (user IP address and other information) and the corresponding PCRFID). The network is the service channel user plane of the user terminal UE: UE—4G base station—SGW (or SGW-U)—PGW (or PGW-U)—corresponding external IP network (Note: SGW-U is Serving Gateway User Plane, indicating the service gateway user plane); for applications that require user IP address conversion (such as access to Internet applications, etc.), the SGi / Gi firewall between PGW / PGW-U and the external IP network completes the IP address conversion of the user terminal UE, for example: converting the IPv4 private address assigned to the user terminal UE by PGW / PGW-C into an IPv4 public address; among them, SGW and PGW are usually collectively set as SAE-GW, SGW-C and PGW-C are usually collectively set as SAEGW-C, and SGW-U and PGW-U are usually collectively set as SAEGW-U;

[0070] Step 2: When the application function network element (such as NEF, AAC, SCEF, AF, etc.) needs to send a policy application message (Rx interface signaling message), it first needs to derive the address of the PGW / PGW-C responsible for the user's IP address service based on the user's IP address information; if the user terminal UE does not undergo IP address conversion (such as IPv6 address) when accessing the external IP network, the application function network element can directly derive the address of the PGW / PGW-C responsible for the user's IP address service; if the user terminal UE undergoes IP address conversion when accessing the external IP network (such as SGi / Gi firewall converts the IPv4 private address assigned by PGW / PGW-C to the IPv4 public address), the application function network element can derive the address of the PGW / PGW-C assigned to the user terminal UE based on the address and NAT (Network Address Traslation) / PAT (Port Address Translation) assigned by PGW / PGW-C to the user terminal UE. The address of the PGW / PGW-C responsible for the service of this user IP address (the user IP address before and after the conversion) is derived from the user IP address converted by port translation; then the address of the PCRF responsible for the service of this user IP address is queried from the PGW / PGW-C responsible for the service of this user IP address;

[0071] Step 3. After receiving the PCRF address query message initiated by the application function network element, the PGW / PGW-C retrieves the PCRF device identifier (PCRFID) responsible for carrying the PCC policy control of this user terminal UE (the IP address (IPv4 private address, IPv6 address) assigned to the user terminal UE by the PGW / PGW-C) according to the mapping relationship (binding information) between the IP address of the user terminal UE (the IP address (IPv4 private address, IPv6 address) assigned to the user terminal UE by the PGW / PGW-C) and the corresponding PCRFID recorded and saved by its built-in BSF function in step 1; then, the PCRFID is returned to the application function network element in the query response message;

[0072] Step 4: After receiving the PCRFID in the query response message, the application function network element sends a policy request message (Rx interface signaling message) to the corresponding PCRF (i.e., the PCRF selected in the Gx interface signaling process during the bearer establishment process of this user terminal UE in step 1);

[0073] Step 5: After receiving the policy request message (Rx interface signaling message) sent by the application function network element, the PCRF retrieves the Gx interface session carried by the user terminal UE and executes the policy request received from the application function network element. The subsequent process is omitted.

[0074] (2) 5G service scenarios (including 4G / 5G converged network element scenarios)

[0075] The 3GPP international standard specifies the BSF network functions and related business processes in the 5G SA network, namely: an independent BSF logical function is introduced into the network. Specifically, an independent BSF can be set up, or the BSF can be combined with network elements such as PCF, UDR, NRF, SMF, etc. However, due to its shortcomings such as complex network structure and business processes, and excessive occupation of network resources, China Mobile did not adopt the BSF solution of the 3GPP international standard, but instead adopted the SMF built-in BSF function solution. The two solutions are introduced below.

[0076] (2.1) 3GPP international standard BSF solution (including BSF independent setting solution and BSF and SMF integrated setting solution)

[0077] Step 1: The user terminal UE accesses the core network AMF through the 5G SA wireless network. In the process of establishing a PDU session for the user terminal UE (equivalent to the "bearer" in the 4G network), the SMF allocates an IPv4 private address and / or IPv6 address to the user terminal UE for the user terminal UE to access the external IP network; and the SMF initiates the PCC process, directly or through the NRF or through the NRF / SCP (Session Control Protocol) to address the corresponding PCF. The N7 interface signaling message sent by the SMF to the PCF includes: the user IP address (IPv4 private address and / or IPv6 address), DNN, S-NSSAI (i.e., network slice identifier), SMF device identifier and other information assigned to the user terminal UE by the SMF; the PCF processes the N7 interface signaling information, initiates a registration process to the BSF, and creates "binding information" in the BSF. The "binding information" includes: the PDU session information of the user terminal UE (the address of the user terminal UE (IPv4 private address and its IP domain, or IPv6 address, or Ethernet address), DNN, S-NSSAI, SUPI (optional), GPSI (Generic Public Subs cription Identifier) ​​(optional)) and PCF information (PCF address (host name (ie FQDN, Fully Qualified Domain Name) or IP address), PCF instance ID (optional), PCF group ID (optional), binding level (optional)); After BSF completes the "binding" of the N7 interface session of the user terminal UE with the PCF address, PCF sends the relevant PCC policy to SMF through the N7 interface, and SMF executes the subsequent process of establishing a PDU session for the user terminal UE. The network is the service channel user plane of the user terminal UE: UE—5G base station—(I-UPF)—UPF—corresponding external IP network (Note: I-UPF is IntermediateUPF, indicating the relay user plane function); for applications that require user IP address conversion (such as access to Internet applications, etc.), the N6 firewall between the UPF and the external IP network completes the IP address conversion of the user terminal UE, for example: converting the IPv4 private address assigned to the user terminal UE by the SMF into an IPv4 public address;

[0078] Step 2: When the application function network element (such as NEF, AAC, SCEF, AF, etc.) needs to send a policy application message (N5 / N30 interface signaling message), it first queries the corresponding BSF for the corresponding PCF address with the user address information (IPv4 private address and its IP domain, or IPv6 address, or Ethernet address) and DNN and S-NSSAI information (Note: the application function network element addresses the corresponding BSF directly or through NRF or through NRF / SCP);

[0079] Step 3: After receiving the PCF address query message initiated by the application function network element, the BSF retrieves the address of the PCF controlled by the PCC policy responsible for the PDU session of the user terminal UE according to the mapping relationship between the PDU session information of the user terminal UE "bound" by the PCF in the BSF in step 1 (the address of the user terminal UE (IPv4 private address and its IPdomain, or IPv6 address, or Ethernet address), DNN, S-NSSAI, SUPI (optional), GPSI (optional)) and the PCF information (PCF address (host name (FQDN) or IP address), PCF instance ID (optional), PCF group ID (optional), binding level (optional)); then, in the query response message, the address of the PCF is returned to the application function network element;

[0080] Step 4: After the application function network element obtains the PCF address from the BSF, it sends a policy request message (N5 / N30 interface signaling message) to the corresponding PCF (i.e., the PCF selected in the N7 interface signaling process during the PDU session establishment process of this user terminal UE in step 1); the N5 / N30 interface signaling message contains the PDU session information of this user terminal UE (the address of the user terminal UE (IPv4 private address and its IP domain, or IPv6 address, or Ethernet address), DNN, S-NSSAI, SUPI (optional), GPSI (optional));

[0081] Step 5: After receiving the policy request message (N5 / N30 interface signaling message) sent by the application function network element, the PCF retrieves the N7 interface session of the PDU session of this user terminal UE and executes the policy request received from the application function network element. The subsequent process is omitted.

[0082] (2.2) China Mobile BSF solution (SMF built-in BSF function solution)

[0083] Step 1: The user terminal UE accesses the core network AMF through the 5G SA wireless network. In the process of establishing a PDU session (equivalent to the "bearer" in the 4G network) for the user terminal UE, the SMF, SMF / PGW-C (4G / 5G converged network element) allocates an IPv4 private address and / or IPv6 address to the user terminal UE for the user terminal UE to access the external IP network; and the SMF, SMF / PGW-C initiates the PCC process, directly or through the NRF or through the NRF / SCP addressing the corresponding PCF / PCRF, and the N7 interface signaling message sent by the SMF, SMF / PGW-C to the PCF / PCRF includes: the user IP address (IPv4 private address and / or IPv6 address), DNN, S-NSSAI (network slice identifier), SMF, SMF / PGW-C device identifier and other information; after receiving the response message returned by PCF / PCRF (directly or through NRF / SCP), the BSF function built into SMF, SMF / PGW-C records and saves the address of PCF / PCRF in the response (PCF / PCRF device identifier), which is the PCF / PCRF device identifier responsible for the PCC policy control of the PDU session / bearer of this user terminal UE (that is, the mapping relationship (binding information) between the current PDU session / bearer of the user terminal UE (user IP address and other information) and the corresponding PCF / PCRF device identifier). The network is the service channel user plane of the user terminal UE: UE—5G / 4G base station—(I-UPF or I-UPF / SGW-U)—UPF (or UPF / PGW-U or UPF / SAEGW-U)—corresponding external IP network; for applications that require user IP address conversion (such as access to Internet applications, etc.), the N6 / SGi firewall between UPF / PGW-U, UPF / SAEGW-U and the external IP network completes the IP address conversion of the user terminal UE, for example: converting the IPv4 private address assigned to the user terminal UE by SMF, SMF / PGW-C into an IPv4 public address;

[0084] Step 2: When the application function network element (such as NEF, AAC, SCEF, AF, etc.) needs to send a policy application message (N5 / N30 / Rx interface signaling message), it first needs to derive the address of the SMF, SMF / PGW-C responsible for the user's IP address service based on the user's IP address information; if the user terminal UE does not undergo IP address conversion (such as IPv6 address) when accessing the external IP network, the application function network element can directly derive the address of the SMF, SMF / PGW-C responsible for the user's IP address service; if the user terminal UE undergoes IP address conversion (such as N6 / The SGi firewall converts the IPv4 private address assigned by SMF, SMF / PGW-C to the IPv4 public address of the user terminal UE. The application function network element can deduce the address of the SMF, SMF / PGW-C responsible for the service of this user IP address (the user IP address before conversion and the user IP address after conversion) according to the address assigned by SMF, SMF / PGW-C to the user terminal UE and the user IP address after NAT / PAT conversion; then query the SMF, SMF / PGW-C responsible for the service of this user IP address for the address of the PCF / PCRF responsible for the service of this user IP address;

[0085] Step 3: After receiving the PCF / PCRF address query message initiated by the application function network element, the SMF and SMF / PGW-C retrieve the PCF / PCRF address controlled by the PCC policy of the PDU session responsible for the user terminal UE (the IP address (IPv4 private address, IPv6 address) assigned to the user terminal UE by the SMF and SMF / PGW-C) according to the mapping relationship (binding information) between the IP address of the user terminal UE (the IP address (IPv4 private address, IPv6 address) assigned to the user terminal UE by the SMF and SMF / PGW-C) recorded and saved by its built-in BSF function in step 1 and the corresponding PCF / PCRF address; then, in the query response message, the PCF / PCRF address is returned to the application function network element;

[0086] Step 4: After receiving the PCF / PCRF address in the query response message, the application function network element sends a policy request message (N5 / N30 / Rx interface signaling message) to the corresponding PCF / PCRF (i.e., the PCF / PCRF selected in the N7 interface signaling process during the PDU session / bearer establishment process of this user terminal UE in step 1);

[0087] Step 5: After receiving the policy request message (N5 / N30 / Rx interface signaling message) sent by the application function network element, the PCF / PCRF retrieves the PDU session / bearer N7 interface session of this user terminal UE and executes the policy request received from the application function network element. The subsequent process is omitted.

[0088] The existing 3GPP international standard BSF solutions described in (2.1) above (including: independent BSF solution, BSF and PCF, UDR, NRF, SMF and other network elements co-location solution) have the following four main disadvantages:

[0089] (1) In the PCC process of establishing the PDU session / bearer of the user terminal UE, the PCF initiates a registration process to the BSF. To create "binding information" in the BSF and update / delete "binding information" in subsequent business processes, the PCF needs to configure additional processing resources. Whether the BSF is set up independently or in combination with network elements such as PCF, UDR, NRF, SMF, etc., it is necessary to configure resources for saving "binding information" and processing resources for creating / updating / deleting "binding information". In addition, when the proportion of business demand on the N7 / N30 / Rx interface is low, the actual utilization rate of "binding information" is low, resulting in Waste of hardware and software resources and investment of PCF and BSF; for example, if only 1 million of 10 million user PDU sessions / bearers have PCC policy control requirements of application function network elements, then only 1 million of the 10 million "binding information" created by PCF and BSF in the PCC process of establishing PDU sessions / bearers of user terminals UE will be used, and the other 9 million "binding information" will only occupy the hardware and software resources of PCF and BSF and will never be used, and at the same time increase the time to establish these 9 million user PDU sessions / bearers;

[0090] (2) In the case where the user terminal UE undergoes IP address conversion when accessing the external IP network (for example, the N6 / SGi firewall converts the IPv4 private address assigned by the SMF, SMF / PGW-C to the IPv4 public address), the PCF needs to provide the "domain" (IP domain, whose value depends on the IPv4 public address segment) corresponding to the IPv4 private address in the "ipDomain" parameter in the "binding information". To meet the user roaming scenario, the PCF needs to configure the IP domain data of the IPv4 private address of the entire network of the operator, which brings great difficulty to the operation and maintenance of the PCF. Alternatively, the SMF, SMF / PGW-C needs to provide the IPv4 private address of the user terminal UE and its IP domain to the PCF in the N7 interface process. However, this method requires the SMF, SMF / PGW-C to configure the correspondence between the IPv4 private address and the IP domain, which brings certain complexity to the operation and maintenance of the SMF, SMF / PGW-C;

[0091] (3) The use of S-NSSAI and / or IPv4 private address IP domain in the "binding information" solves the problem of private IP address reuse of the user terminal UE. However, it cannot meet the scenario where different DNNs of the same user / different users reuse IP addresses in the same network slice (same S-NSSAI);

[0092] (4) In the "binding information", the "ipDomain" parameter is only defined for IPv4 addresses. The existing technical solution does not support the NAT / PAT conversion scenario of IPv6 addresses (such as the ULCL scenario of 5G SA).

[0093] The existing China Mobile BSF solution (SMF built-in BSF function solution) described in (2.2) above is applicable to the service application scenarios of 4G network, 5G network, and 4G / 5G converged core network, and has the following two main disadvantages:

[0094] (1) When the application function network element queries the SMF / PGW-C / PGW / BSF for the PCF / PCRF address, the query parameters only include the user's IPv4 private address / IPv6 address. Therefore, the service scenario where different DNN / APN services of the same / different user terminals UE reuse the same IP address (IPv4 private address or IPv6 address) cannot be met;

[0095] (2) 5G core network and 4G / 5G converged core network adopt service channels (5G The 4G core network also introduces a C / U separation architecture (SGW-C / PGW-C and SGW-U / PGW-U are separated). The same user plane network element (UPF, UPF / SGW-U / PGW-U, SGW-U / PGW-U) can be controlled by multiple control plane network elements (SMF, SMF / SGW-C / PGW-C, SGW-C / PGW-C) at the same time, that is, a control plane network element (SMF, SMF / SGW-C / PGW-C, SGW-C / PGW-C) can select different IPv4 private address "domains" (IPv4 private addresses) when establishing PDU sessions / bearers for different user terminals UE of the same DNN / APN. For user plane network elements (UPF, UPF / SGW-U / PGW-U, SGW-U / PGW-U) of different domains (connected to different N6 / SGi firewalls, and the N6 / SGi firewalls are responsible for the NAT / PAT conversion of IPv4 private addresses to IPv4 public addresses), when multiple user plane network elements controlled by the same control plane network element reuse the IPv4 private address pool for the same DNN / APN, when the application function network element queries the control plane network element SMF / PGW-C / PGW / BSF for the PCF / PCRF address, the query parameters only include the user IPv4 private address / IPv6 address. Therefore, for different IPv4 private address "domains" (IP domain) and the user plane network element that reuses the IPv4 private address is responsible for unblocking two user terminals UE with the same IPv4 private address (even if it is the same DNN / APN). The control plane network element SMF / PGW-C / PGW / BSF cannot determine which user terminal UE's corresponding PCF / PCRF address (when the PDU sessions / bearers of the two user terminals UE are controlled by different PCF / PCRFs respectively) should be returned to the application function network element as the query result.

[0096] In view of the shortcomings of the above-mentioned existing 3GPP international standard BSF solution (including BSF independent setting solution, BSF and SMF network element integrated setting solution) and the above-mentioned existing China Mobile BSF solution (SMF built-in BSF function solution), the embodiment of the present invention proposes a new technical solution for application function network elements (such as: NEF, AAC, SCEF, AF, etc.) to address PCC policy control network elements, which is mainly used to solve the following problems: (1) It is applicable to business scenarios of 4G network, 5G network, 4G / 5G converged core network and subsequent evolution of mobile communication network; (2) It is applicable to the same user (3) Applicable to the business scenario where different DNN / APN services of different user / different user terminals UE reuse the same IP address (IPv4 private address or IPv6 address); (4) While satisfying all business scenarios, the "binding information" and business processes occupy as few network resources as possible.

[0097] See also Figure 1 FIG. 1 is a PCC system architecture diagram provided by an embodiment of the present invention. Figure 1 The principle of the embodiment of the present invention is described as follows: Figure 1The PCC system architecture shown includes a user terminal UE, a wireless access network element, an access and mobility management function network element, a service channel establishment user plane network element, a service channel establishment control plane network element (also serving as a policy binding network element), a policy control network element, a policy database network element and an application function network element; an embodiment of the present invention proposes a novel method for an application function network element to address a PCC policy control network element, and is applicable to a PCC networking scenario in which a policy control network element (such as PCF, PCF / PCRF, PCRF) is grouped as a POOL. The technology of using a service channel establishment control plane network element (network function: such as SMF, SMF / PGW-C, PGW-C) as a policy binding network element (such as BSF) is adopted to return the query result of the address of the policy control network element (such as PCF, PCF / PCRF, PCRF) to the application function network element, and is applicable to networking scenarios such as 4G networks, 5G networks, 4G / 5G converged core networks, and subsequent mobile communication network evolution. The application function network element (such as NEF, AAC, SCEF, AF, etc.) uses the user terminal UE address (IP address, etc.), the service channel establishment control plane network element / policy binding network element device address (device identification), the mobile communication network access external network identification (5G: DNN+S-NSSAI, 4G: APN) and other information to first query the policy binding network element (such as BSF) that is also the service channel establishment control plane network element (network function: such as SMF, SMF / PGW-C, PGW-C) to which the user terminal UE currently belongs (responsible for its service channel establishment / modification / deletion), and query the address of the policy control network element (such as PCF, PCF / PCRF, PCRF) that is currently responsible for the PCC policy control of the PDU session / bearer of the user terminal UE. After obtaining the address of the corresponding policy control network element (such as PCF, PCF / PCRF, PCRF) from the query result, the application function network element sends a PCC policy request to the corresponding policy control network element.

[0098] The first aspect of the present invention provides a method for addressing a policy control network element. Figure 2 As shown, it is a flowchart of a preferred embodiment of a policy control network element addressing method provided by the first aspect of the present invention, the method is applied to an application function network element, and the method includes steps S11 to S14:

[0099] Step S11: after the control plane network element establishes a service channel for the user terminal accessing the mobile communication network, determine the PCC policy control to be executed on the user terminal; wherein, during the establishment of the service channel, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of N control plane network elements configured by the control plane network element correspond to N reused user IP address pools respectively, and N>1;

[0100] Step S12: Obtain the address of the control plane network element currently responsible for the user terminal service;

[0101] Step S13: Send an address query request for the policy control network element currently responsible for the service channel PCC policy control of the user terminal service to the corresponding control plane network element according to the address of the control plane network element;

[0102] Step S14: Receive the query result of the address of the policy control network element sent by the control plane network element.

[0103] Among them, in the embodiment of the present invention, the "control plane network element" is equivalent to the "service channel establishment control plane network element", and the "user plane network element" is equivalent to the "service channel establishment user plane network element".

[0104] Combination Figure 3 As shown, it is a business flow chart of an addressing method of a policy control network element provided in an embodiment of the present invention. After the user terminal UE accesses the mobile communication network, the service channel establishment control plane network element (network function: such as: 5G SMF, 4G / 5GSMF / PGW-C, 4G PGW-C, 4G PGW) establishes a service channel for the user terminal UE (such as: 5G PDU session, 4G bearer). In this process, the service channel establishment control plane network element starts the PCC process, and through the service channel establishment control plane network element and the policy control network element (such as: 5G PCF, 4G / 5G PCF / PCRF, 4G PCRF) interface (such as: 5G N7 interface, 4G / 5G N7 interface, 4G Gx interface) The interface between the user terminal UE service channel PCC session association establishment and modification process (such as: 5GSM Policy Association, 4G IP CAN Session Establishment) is initiated to the policy control network element, and the policy control network element obtains the service channel PCC session association establishment and modification process (such as: 5GSM Policy Association, 4G IP CAN Session Establishment) from the corresponding policy database network element (such as: 5G UDR, 4G / 5G UDR / SPR, 4G After obtaining the PCC subscription data of the user terminal UE in the SPR, the relevant PCC policy rule information is sent to the service channel establishment control plane network element; the service channel establishment control plane network element and the policy control network element establish a PCC policy session association for the current service transmission channel of the user terminal UE (such as: 5GPDU session, 4G bearer). Through this PCC policy session association, the policy control network element can issue and update / modify the PCC rules of the current service transmission channel of the user terminal UE to the service channel establishment control plane network function of the user terminal UE. The service channel establishment control plane network function of the user terminal UE cooperates with other relevant network elements to execute the corresponding PCC rule policy; among them, on the basis of the existing standard specifications, the following service processing flow needs to be added:

[0105] (1) When multiple service channel establishment user plane network elements (network functions: such as 5G UPF, 4G / 5G UPF / PGW-U, 4G PGW-U) controlled / managed by the same service channel establishment control plane network element (network function: such as 5G SMF, 4G / 5G SMF / PGW-C, 4GPGW-C) reuse the user IP address, the service channel establishment control plane network element shall configure the corresponding device identifier (local device identifier, such as 5G SMF device identifier (FQDN and / or NF instance ID), 4G / 5G SMF / PGW-C device identifier (FQDN and / or NF instance ID), 4G PGW-C equipment identifier (FQDN), and the equipment identifiers of each service channel establishment control plane network element correspond to different reused user IP address pools; after the service channel establishment control plane network element allocates a user IP address to the user terminal UE, the PCC process is initiated with the service channel establishment control plane network element equipment identifier corresponding to the user IP address pool for the interface with the policy control network element, and the message contains the service channel establishment control plane network element equipment identifier of the local end for the interface with the policy control network element, that is, the service channel establishment control plane network element corresponding to the user IP address pool for the service channel establishment control plane network element for the interface with the policy control network element;

[0106] (2) After receiving the message returned by the policy control network element, the service channel establishment control plane network element / policy binding network element (such as: 5G SMF / BSF, 4G / 5G SMF / PGW-C / BSF, 4G PGW-C / BSF) saves the PCC policy session association information of this service channel (such as: 5G PDU session, 4G bearer) of the user terminal UE, including: the service channel establishment control plane network element used by the service channel establishment control plane network element for the interface between the policy control network element, the user IP address, the mobile communication network access external network identifier (such as: 5G DNN+S-NSSAI, 4G APN), the device address of the policy control network element (such as: 5G PCF device identifier (FQDN and / or NF instance ID and / or IP address), 4G / 5G PCF / PCRF device identifier (FQDN and / or NF instance ID / or IP address), 4G PCRF device identifier (FQDN / or IP address)) The binding data between these four are shown in Table 1.

[0107] Table 1 Binding data table (example)

[0108]

[0109]

[0110] Note 1: If there is no reuse of user IP addresses (e.g., multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element are directly connected to the external data network, that is, there is no NAT / PAT firewall between the service channel establishment user plane network element and the external data network to which it is connected, and there is no reuse of user IP address pools for different mobile communication networks to access external network identifiers (5G: DNN+S-NSSAI, 4G: APN)), then all user IP addresses (IPv4 addresses or IPv6 addresses) in the "User IP address assigned to UE" column will not be repeated;

[0111] Note 2: If the multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element do not reuse user IP addresses (e.g., the multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element are all connected to the external data network through the same NAT / PAT firewall), then the value of the parameter / column "service channel establishment control plane network element device identifier for the interface with the policy control network element" is exactly the same for all user terminals UE, that is, the unique device identifier of the service channel establishment control plane network element for the interface with the policy control network element (e.g., device identifier 1); If multiple service channel establishment user plane network elements controlled / governed by the same service channel establishment control plane network element have reused user IP addresses (e.g., multiple service channel establishment user plane network elements controlled / governed by the same service channel establishment control plane network element access the external data network through N NAT / PAT firewalls), then the "service channel establishment control plane network element device identifier for the interface with the policy control network element" parameter / column should have multiple service channel establishment control plane network element device identifiers for the interface with the policy control network element (e.g., device identifiers 1-1 to 1-N), which correspond to multiple reused user IP address pools respectively;

[0112] Note 3: If there is no situation where different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the "Mobile communication network access external network identifier" parameter / column does not need to be used as binding data;

[0113] Note 4: If different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the "Mobile communication network access external network identifier" parameter / column needs to be used as binding data; among them: for 5G networks with only a single network slice, the "S-NSSAI" parameter does not need to be used as binding data.

[0114] Combining the above content and Figure 3 As shown, in the specific implementation of the embodiment of the present invention, the application function network element (such as: NEF, AAC, SCEF, AF, etc.) first determines the PCC policy control that needs to be executed on the user terminal UE after the control plane network element establishes the service channel for the user terminal UE accessing the mobile communication network; as described above, in the process of establishing the service channel, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools, N>1; thereafter, the application function network element obtains the service channel establishment currently responsible for the user terminal service The address of the control plane network element, and establish the address of the control plane network element according to the obtained service channel, and send an address query request for the policy control network element that is currently responsible for the PCC policy control of the service channel of the user terminal UE service to the corresponding control plane network element, that is: to query the address of the policy control network element that is currently responsible for the PCC policy control of the corresponding service channel of the user terminal UE from the service channel currently responsible for the user terminal UE service to establish the control plane network element / policy binding network element, so as to establish the control plane network element / policy binding network element from the service channel currently responsible for the user terminal UE service.

[0115] It should be noted that after the application function network element obtains the corresponding service channel establishment control plane network element / policy binding network element address, it sends a policy control network element address query request message to the corresponding service channel establishment control plane network element / policy binding network element address. The query request message must include: the IP address of the user terminal UE assigned by the service channel establishment control plane network element, the service channel establishment control plane network element / policy binding network element device address (device identifier), and the mobile communication network access external network identifier (5G: DNN+S-NSSAI, 4G: APN) corresponding to the user terminal UE service channel. The service channel establishment control plane network element / policy binding network element queries Table 1 based on the above three parts of information in the query request message, matches the corresponding policy control network element address, and returns the matched policy control network element address to the application function network element in the query response message.

[0116] Note 1: If the multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element do not reuse user IP addresses (for example, the multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element are all connected to the external data network through the same NAT / PAT firewall), then the query request message may not include the "service channel establishment control plane network element / policy binding network element device address (device identifier)";

[0117] Note 2: If there is no situation where different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the "mobile communication network access external network identifier" may not be included in the query request message;

[0118] Note 3: If there is a situation where different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the query request message needs to include the "mobile communication network access external network identifier", where: for a 5G network with only a single network slice, the "mobile communication network access external network identifier" may not include the "S-NSSAI" parameter;

[0119] Note 4: The "Policy Control Network Element Address" in the query response message may include both the "Device Identifier" and the "Device IP Address". It may also include only the "Device Identifier", and the application function network element obtains the "Device IP Address" or routes the policy request message to the "Device IP Address" through other means (such as: through DNS query, NRF service discovery, signaling network addressing, etc.).

[0120] In another preferred embodiment, the method further comprises:

[0121] According to the address of the policy control network element obtained from the query result, a policy application request is sent to the policy control network element; wherein the policy application request includes the IP address of the user terminal assigned by the control plane network element, the device identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0122] Specifically, in combination with the above embodiments and Figure 3 As shown, the application function network element sends a policy application request (such as: N5 interface signaling message of 5G network, Rx interface signaling message of 4G network) to the policy control network element with the address of the policy control network element obtained from the query of the service channel establishment control plane network element / policy binding network element. The policy application request message includes: the IP address of the user terminal UE assigned by the service channel establishment control plane network element, the service channel establishment control plane network element / policy binding network element device address (device identification), and the mobile communication network access external network identification corresponding to the user terminal UE service channel (such as: 5G: DNN+S-NSSAI, 4G: APN). After receiving the policy application request message (such as: N5 interface signaling message of 5G network, Rx interface signaling message of 4G network), the policy control network element performs corresponding PCC policy control on the corresponding user terminal UE service channel (such as: 5G PDU session, 4G bearer), and the subsequent service process complies with the existing specifications.

[0123] Note 1: If the multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element do not reuse user IP addresses (for example, the multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element are all connected to the external data network through the same NAT / PAT firewall), then the "service channel establishment control plane network element / policy binding network element device address (device identifier)" may not be included in the policy application request message;

[0124] Note 2: If there is no situation where different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the "mobile communication network access external network identifier" may not be included in the policy application request message;

[0125] Note 3: If different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the "mobile communication network access external network identifier" needs to be included in the policy application request message. For a 5G network with only a single network slice, the "S-NSSAI" parameter may not be included in the "mobile communication network access external network identifier".

[0126] In another preferred embodiment, the obtaining the address of the control plane network element currently responsible for the user terminal service includes:

[0127] By configuring local static data, configuring the local configuration information to a mapping table of the device address of the control plane network element; wherein the local configuration information includes the IP address of the user terminal assigned by the control plane network element, the IP address of the user terminal after address conversion, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal;

[0128] The mapping table of the device address of the control plane network element is queried according to the local configuration information to obtain the address of the control plane network element currently responsible for the user terminal service.

[0129] Specifically, in combination with the above embodiments, the application function network element needs to obtain in some way: the IP address (such as: 5G SMF, 4G / 5G SMF / PGW-C, 4G PGW-C assigned to the user terminal UE) allocated by the control plane network element established by the service channel of the user terminal UE (allocated to the user terminal UE during the establishment of the UE's service channel (such as: 5G PDU session, 4G bearer)) (such as: 5G SMF, 4G / 5G SMF / PGW-C, 4G PGW-C assigned to the user terminal UE IPv4 private address or IPv6 address), the NAT / PAT firewall (such as: 5G UPF, 4G / 5G UPF / PGW-U, 4G The three pieces of information are the IP address (such as IPv4 public address or IPv6 address) converted by the N6, N6 / SGi, SGi / Gi interface NAT / PAT firewall) between the PGW-U and the accessed Internet, and the mobile communication network access external network identifier (such as 5G: DNN+S-NSSAI, 4G: APN) corresponding to the user terminal UE service channel, and the corresponding service channel is addressed with the above three pieces of information to establish a control plane network element / policy binding network element. There are two specific methods (choose one of the two methods).

[0130] In this embodiment, method 1 is adopted: the application function network element addresses the corresponding service channel establishment control plane network element / policy binding network element through local static data configuration; that is, the application function network element is locally configured: the IP address of the user terminal UE assigned by the service channel establishment control plane network element, the IP address of the user terminal UE after NAT / PAT firewall conversion between the user plane network element established by the service channel and the external data network connected, and the mobile communication network access external network identifier corresponding to the user terminal UE service channel, and these three parts of information are configured to the mapping table of the service channel establishment control plane network element / policy binding network element device address, as shown in Table 2 below.

[0131] Table 2 Service channel establishment control plane network element / policy binding network element device address mapping table (example)

[0132]

[0133]

[0134]

[0135]

[0136] Note 1: "The domain name to which the IP address segment of the user terminal UE belongs after the NAT / PAT firewall between the user plane network element established by the service channel and the external data network to which it is connected (the IP address belongs to the same NAT / PAT firewall)" means: IPDomain parameter / column, which is optional;

[0137] Note 2: If there is no service channel to establish a user plane network element to access the external data network through a NAT / PAT firewall, and the user IP address conversion is completed by the NAT / PAT firewall, then the "IP address segment after conversion by the NAT / PAT firewall between the user plane network element established by the service channel and the external data network connected to the user terminal UE" parameter / column and "Domain name to which the IP address segment after conversion by the NAT / PAT firewall between the user plane network element established by the service channel and the external data network connected to the user terminal UE belongs (IP address belongs to the same NAT / PAT firewall)" parameter / column are not required;

[0138] Note 3: If there is no situation where different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the "Mobile communication network access external network identifier" parameter / column is not required;

[0139] Note 4: If different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the "Mobile communication network access external network identifier" parameter / column must exist; among them: for 5G networks with only a single network slice, the "S-NSSAI" parameter is not required.

[0140] In another preferred embodiment, the obtaining the address of the control plane network element currently responsible for the user terminal service includes:

[0141] Obtaining service discovery query parameters; wherein the service discovery query parameters include the IP address of the user terminal assigned by the control plane network element, the mobile communication network access external network identifier corresponding to the service channel of the user terminal, and the domain name to which the IP address derived from the IP address of the user terminal after address conversion belongs;

[0142] Execute the control plane network element service discovery process to the network storage function according to the service discovery query parameter; wherein the registration information of the control plane network element to the network storage function includes the address of the control plane network element and the local device addressing identifier;

[0143] Receiving a service discovery response message sent by the network storage function based on the registration information, and acquiring an address of a control plane network element according to the service discovery response message;

[0144] Then, the address query request includes the IP address of the user terminal allocated by the control plane network element, the local device addressing identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0145] Specifically, in combination with the above embodiment, addressing the corresponding service channel to establish a control plane network element / policy binding network element also includes method 2: the application function network element addresses the corresponding service channel to establish a control plane network element / policy binding network element by dynamic query. For method 2, the embodiment of the present invention also proposes two dynamic query methods based on a service discovery (such as 5G service discovery) mechanism. The first method adopted in this embodiment is a full service discovery method, and the implementation process is as follows:

[0146] The policy-bound NE performs NF registration / NF update / NF deregistration (e.g. NFRegister / NFUpdate / NFDeregister for 5G) operations with NRF (or NRF / SCP); the service channel establishment control plane NE / policy-bound NE configures a set of code numbers specifically for policy-bound NEs for the policy-bound NE (e.g. 5G: NF type is "BSF" and the corresponding NFProfile (including NFService)). The service channel establishment control plane NE / policy-bound NE immediately performs registration of the policy-bound NE with NRF (or NRF / SCP) after going online; and when the relevant configuration changes, the policy-bound NE is updated with NRF (or NRF / SCP); and when the NE goes offline, the policy-bound NE is deregistered with NRF (or NRF / SCP). The content that needs to be included in the information registered by the policy-bound NE with NRF (or NRF / SCP) is shown in Table 3 (Note: the 4 examples in the table are applicable to 4 types of policy-bound NEs, and only the content in 1 example exists in the registration table of the same policy-bound NE).

[0147] Table 3 Policy binding network element registration information table (example)

[0148]

[0149]

[0150] Note 1: If there is no service channel to establish a user plane network element to access the external data network through a NAT / PAT firewall, and the user IP address conversion is completed by the NAT / PAT firewall, then the "IP address segment after conversion by the NAT / PAT firewall between the user plane network element established by the service channel and the external data network connected to the user terminal UE" parameter / column and "Domain name to which the IP address segment after conversion by the NAT / PAT firewall between the user plane network element established by the service channel and the external data network connected to the user terminal UE belongs (IP address belongs to the same NAT / PAT firewall)" parameter / column are not required;

[0151] Note 2: If the same service channel establishment control plane network element controls / governs multiple service channel establishment user plane network elements without reuse of user IP addresses (e.g., the same service channel establishment control plane network element controls / governs multiple service channel establishment user plane network elements are connected to the external data network through the same NAT / PAT firewall), then the "Local Device Addressing Identifier" parameter / column has only one value, which is the unique local device identifier of the policy-bound network element (e.g., as shown in Example 1 and Example 3 in Table 3); and the application function network element can address the policy-bound network element with either the "Local Device Addressing Identifier" or the "Basic Device Identifier";

[0152] Note 3: If the same service channel establishes multiple service channels and the user plane network elements controlled / managed by the control plane network element have reused user IP addresses (for example, the same service channel establishes multiple service channels and the user plane network elements controlled / managed by the control plane network element are connected to the external data network through N NAT / PAT firewalls), then the "Local Device Addressing Identifier" parameter / column should have N local device addressing identifiers (for example, local device addressing identifiers 1-1 to 1-N) corresponding to multiple reused user IP address pools; and the application function network element needs to bind the network element with the "Local Device Addressing Identifier" addressing policy;

[0153] Note 4: If there is no situation where different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI) reuse the user IP address pool, the "Mobile communication network access external network identifier" parameter / column is not required;

[0154] Note 5: If there is a situation where different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI) reuse the user IP address pool, the "Mobile communication network access external network identifier" parameter / column must exist; among which: for 5G networks with only a single network slice, the "S-NSSAI" parameter is not required.

[0155] In the above embodiment, the service channel establishment control plane network element / policy binding network element has saved the PCC policy session association information of the service transmission channel of the user terminal UE, and includes the "local device addressing identifier" of the policy binding network element in Table 3, as shown in Table 4.

[0156] Table 4 Policy binding network element binding data table (example)

[0157]

[0158]

[0159] Note 1: If the user IP addresses of multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element do not reuse (for example, multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element are all connected to the external data network through the same NAT / PAT firewall), then the value of the parameter / column "Service channel establishment control plane network element device identifier for the interface with the policy control network element" is exactly the same for all user terminals UE, that is, the unique device identifier of the service channel establishment control plane network element for the interface with the policy control network element (for example, device identifier 1), and the parameter / column "Policy binding network element local device addressing identifier" has only one value, that is, the unique local device identifier of the policy binding network element (for example, as shown in Example 1 and Example 3 in Table 3); and the application function network element can address the policy binding network element with either the "policy binding network element local device addressing identifier" or the "policy binding network element device basic identifier";

[0160] Note 2: If multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element have reused user IP addresses (for example, multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element access the external data network through N NAT / PAT firewalls), then the "Service channel establishment control plane network element device identifier for the interface with the policy control network element" parameter / column should have multiple service channel establishment control plane network element device identifiers for the interface with the policy control network element (for example, device identifiers 1-1 to 1-N), which correspond to multiple reused user IP address pools respectively; and the "Policy binding network element local device addressing identifier" parameter / column should have N policy binding network element local device addressing identifiers (for example, policy binding network element local device addressing identifiers 1-1 to 1-N), which correspond to multiple reused user IP address pools respectively; and the application function network element needs to address the policy binding network element with the "Policy binding network element local device addressing identifier".

[0161] The application function network element needs to obtain these three pieces of information in some way: the IP address of the user terminal UE assigned by the control plane network element established by the service channel, the IP address of the user terminal UE converted by the NAT / PAT firewall between the user plane network element established by the service channel and the external data network to which it is connected, and the mobile communication network access external network identifier corresponding to the user terminal UE service channel. The application function network element needs to derive the domain name to which this IP address belongs (such as the NAT / PAT firewall to which the IP address belongs) based on the IP address converted by the NAT / PAT firewall between the user plane network element established by the service channel and the external data network to which it is connected, that is, the application function network element needs to pre-configure the mapping table shown in Table 5.

[0162] Table 5 Mapping table of application function network element IP address and IP address domain (example)

[0163]

[0164] The application function network element shall use the IP address of the user terminal UE allocated by the control plane network element established by the service channel, the mobile communication network access external network identifier corresponding to the user terminal UE service channel, and the IP address of the user terminal UE mapped by the pre-configured Table 5 after the NAT / PAT firewall conversion between the user plane network element established by the service channel and the external data network connected to derive the domain name to which this IP address belongs, and the above three parts of information as service discovery query parameters to execute the policy binding network element service discovery process to the NRF (or NRF / SCP). The NRF (or NRF / SCP) retrieves the corresponding policy binding network element address based on the registration information of the policy binding network element in the above embodiment (the content in Table 3), and provides the information of the policy binding network element in the service discovery response message, including: the device identifier and IP address of the policy binding network element, and the local device addressing identifier of the policy binding network element.

[0165] Note 1: If the same service channel establishment control plane network element controls / governs multiple service channel establishment user plane network elements and does not reuse user IP addresses (for example, the same service channel establishment control plane network element controls / governs multiple service channel establishment user plane network elements all access the external data network through the same NAT / PAT firewall), then the "local device addressing identifier" of the policy binding network element may not be included in the service discovery response message;

[0166] Note 2: If the same service channel establishes multiple service channels controlled / managed by the control plane network element to establish user plane network elements and there is a situation where user IP addresses are reused (for example: the same service channel establishes multiple service channels controlled / managed by the control plane network element to establish user plane network elements to access the external data network through N NAT / PAT firewalls), then the "local device addressing identifier" of the policy-bound network element must be included in the service discovery response message.

[0167] Correspondingly, after the application function network element obtains the policy binding network element address, it sends a policy control network element address query request message to the corresponding policy binding network element address. The query request message must include: the IP address of the user terminal UE assigned by the service channel establishment control plane network element, the policy binding network element "local device addressing identifier", and the mobile communication network access external network identifier corresponding to the user terminal UE service channel (such as: 5G: DNN+S-NSSAI). The service channel establishment control plane network element / policy binding network element queries Table 4 based on the above three parts of information in the query request message, matches the corresponding policy control network element address and the service channel establishment control plane network element device identifier (abbreviated as: service channel establishment control plane network element device identifier) ​​used for the interface with the policy control network element, and returns the matched policy control network element address and service channel establishment control plane network element device identifier to the application function network element in the query response message.

[0168] Note 1: If the multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element do not reuse user IP addresses (for example, the multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element are all connected to the external data network through the same NAT / PAT firewall), then the "local device addressing identifier" of the policy binding network element may not be included in the query request message, and the service channel establishment control plane network element device identifier may not be included in the query response message;

[0169] Note 2: If multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element reuse user IP addresses (e.g., multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element access the external data network through N NAT / PAT firewalls), the "local device addressing identifier" of the policy binding network element must be included in the query request message, and the service channel establishment control plane network element device identifier must be included in the query response message;

[0170] Note 3: If there is no situation where different mobile communication networks access external network identifiers (such as: 5G: DNN+S-NSSAI) reuse the user IP address pool, the "mobile communication network access external network identifier" may not be included in the query request message;

[0171] Note 4: If there is a situation where different mobile communication networks access external network identifiers (such as: 5G: DNN + S-NSSAI) reuse the user IP address pool, the query request message needs to include the "mobile communication network access external network identifier", where: for a 5G network with only a single network slice, the "mobile communication network access external network identifier" may not include the "S-NSSAI" parameter;

[0172] Note 5: The "Policy Control Network Element Address" in the query response message may include both the "Device Identifier" and the "Device IP Address". It may also include only the "Device Identifier", and the application function network element obtains the "Device IP Address" or routes the policy request message to the "Device IP Address" through other means (such as: through DNS query, NRF service discovery, signaling network addressing, etc.).

[0173] In another preferred embodiment, the obtaining the address of the control plane network element currently responsible for the user terminal service includes:

[0174] By configuring local static data, configuring the local configuration information to a mapping table of the device address of the control plane network element; wherein the local configuration information includes the IP address of the user terminal assigned by the control plane network element, the IP address of the user terminal after address conversion, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal;

[0175] Query the mapping table of the device address of the control plane network element according to the local configuration information to obtain the address of the control plane network element currently responsible for the user terminal service and the local device addressing identifier;

[0176] Then, the address query request includes the IP address of the user terminal allocated by the control plane network element, the local device addressing identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0177] Specifically, in combination with the above embodiments, this embodiment adopts the second dynamic query method based on the service discovery mechanism of method 2: the service channel establishes the control plane network element / policy binding network element IP address service discovery method, and the implementation process is as follows:.

[0178] The policy-bound NE performs NF registration / NF update / NF deregistration (e.g. NFRegister / NFUpdate / NFDeregister for 5G) operations with NRF (or NRF / SCP). The service channel establishment control plane NE / policy-bound NE configures a set of code numbers specifically for policy-bound NEs for the policy-bound NE (e.g. 5G: NF type is "BSF" and the corresponding NFProfile (including NFService)). The service channel establishment control plane NE / policy-bound NE immediately performs registration of the policy-bound NE with NRF (or NRF / SCP) after going online; and when the relevant configuration changes, the policy-bound NE is updated with NRF (or NRF / SCP); and when the NE goes offline, the policy-bound NE is deregistered with NRF (or NRF / SCP). The content that needs to be included in the information registered by the policy-bound NE with NRF (or NRF / SCP) is shown in Table 6 (Note: The two examples in the table are applicable to two types of policy-bound NEs, and only the content in one example exists in the registration table of the same policy-bound NE).

[0179] Table 6 Policy binding network element registration information table (example)

[0180]

[0181] Note 1: If the same service channel establishment control plane network element controls / governs multiple service channel establishment user plane network elements without reuse of user IP addresses (e.g., the same service channel establishment control plane network element controls / governs multiple service channel establishment user plane network elements are connected to the external data network through the same NAT / PAT firewall), then the "Local Device Addressing Identifier" parameter / column has only one value, which is the unique local device identifier of the policy-bound network element (e.g., as shown in Example 1 in Table 6); and the application function network element can address the policy-bound network element with the "Local Device Addressing Identifier" or the "Device Basic Identifier";

[0182] Note 2: If multiple service channel establishment user plane network elements controlled / governed by the same service channel establishment control plane network element have reused user IP addresses (for example, multiple service channel establishment user plane network elements controlled / governed by the same service channel establishment control plane network element access the external data network through N NAT / PAT firewalls), then the service channel establishment control plane network element / policy binding network element should be configured as N policy binding network elements (such as policy binding network elements 1-1 to 1-N), corresponding to N reused user IP address pools respectively; as shown in Example 2 in Table 6; and the application function network element needs to address the policy binding network element with the corresponding "local device addressing identifier" or the corresponding "device basic identifier".

[0183] In the above embodiment, the service channel establishment control plane network element / policy binding network element has saved the PCC policy session association information of the service transmission channel of the user terminal UE, and includes the "local device addressing identifier" of the policy binding network element in Table 6, as shown in Table 4.

[0184] The application function network element addresses the corresponding service channel establishment control plane network element / policy binding network element through local static data configuration; that is, the application function network element local configuration: the IP address of the user terminal UE allocated by the service channel establishment control plane network element, the IP address of the user terminal UE after NAT / PAT firewall conversion between the user plane network element established by the service channel and the external data network connected, and the mobile communication network access external network identifier corresponding to the user terminal UE service channel. These three pieces of information are mapped to the service channel establishment control plane network element / policy binding network element device address, as shown in Table 7.

[0185] Table 7 Service channel establishment control plane network element / policy binding network element device address mapping table (example)

[0186]

[0187]

[0188]

[0189]

[0190] Note 1: "The domain name to which the IP address segment of the user terminal UE belongs after the NAT / PAT firewall between the user plane network element established by the service channel and the external data network to which it is connected (the IP address belongs to the same NAT / PAT firewall)" means: IPDomain parameter / column, which is optional;

[0191] Note 2: If there is no service channel to establish a user plane network element to access the external data network through a NAT / PAT firewall, and the user IP address conversion is completed by the NAT / PAT firewall, then the "IP address segment after conversion by the NAT / PAT firewall between the user plane network element established by the service channel and the external data network connected to the user terminal UE" parameter / column and "Domain name to which the IP address segment after conversion by the NAT / PAT firewall between the user plane network element established by the service channel and the external data network connected to the user terminal UE belongs (IP address belongs to the same NAT / PAT firewall)" parameter / column are not required;

[0192] Note 3: If there is no situation where different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the "Mobile communication network access external network identifier" parameter / column is not required;

[0193] Note 4: If different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) reuse the user IP address pool, the "Mobile communication network access external network identifier" parameter / column must exist; among them: for 5G networks with only a single network slice, the "S-NSSAI" parameter is not required.

[0194] The application function network element shall use the policy-bound network element device identifier mapped by the pre-configured Table 7 as the service discovery query parameter to perform the policy-bound network element service discovery process to the NRF (or NRF / SCP). The NRF (or NRF / SCP) retrieves the corresponding policy-bound network element address based on the registration information of the policy-bound network element in the above embodiment (the content in Table 6), and provides the information of the policy-bound network element in the service discovery response message, including: the device IP address of the policy-bound network element.

[0195] Correspondingly, after the application function network element obtains the policy binding network element address, it sends a policy control network element address query request message to the corresponding policy binding network element address. The query request message must include: the IP address of the user terminal UE assigned by the service channel establishment control plane network element, the policy binding network element "local device addressing identifier", and the mobile communication network access external network identifier corresponding to the user terminal UE service channel (such as: 5G: DNN+S-NSSAI). The service channel establishment control plane network element / policy binding network element queries Table 4 based on the above three parts of information in the query request message, matches the corresponding policy control network element address and the service channel establishment control plane network element device identifier (abbreviated as: service channel establishment control plane network element device identifier) ​​used for the interface with the policy control network element, and returns the matched policy control network element address to the application function network element in the query response message.

[0196] Note 1: If there is no situation where different mobile communication networks access external network identifiers (such as: 5G: DNN+S-NSSAI) reuse the user IP address pool, the "mobile communication network access external network identifier" may not be included in the query request message;

[0197] Note 2: If there is a situation where different mobile communication networks access external network identifiers (such as: 5G: DNN + S-NSSAI) reuse the user IP address pool, the query request message needs to include the "mobile communication network access external network identifier", where: for a 5G network with only a single network slice, the "mobile communication network access external network identifier" may not include the "S-NSSAI" parameter;

[0198] Note 3: The "Policy Control Network Element Address" in the query response message may include both the "Device Identifier" and the "Device IP Address". It may also include only the "Device Identifier", and the application function network element obtains the "Device IP Address" or routes the policy request message to the "Device IP Address" through other means (such as: through DNS query, NRF service discovery, signaling network addressing, etc.).

[0199] It should be noted that in an embodiment of the present invention, for a business scenario in which a user plane network element reuses a user IP address for multiple business channels established by a control plane network element controlled / governed by the same business channel (such as: a user plane network element accesses an external data network through N NAT / PAT firewalls for multiple business channels established by a control plane network element controlled / governed by the same business channel), a business channel establishment control plane network element / policy binding network element (such as: 5G SMF / BSF, 4G / 5G SMF / PGW-C / BSF, 4GPGW-C / BSF) is configured with N business channel establishment control plane network element device identifiers for the interface between the business channel establishment control plane network element and the policy control network element, respectively corresponding to N multiplexed user IP address pools; and this device identifier is used as an important part of the policy binding information, and is applied to the business channel establishment control plane network element and the policy control network element interface (such as: 5G N7 interface, 4G / 5GN7 interface, 4G Rx interface), the application function network element and the business channel establishment control plane network element / policy binding network element interface, the application function network element and the policy control network element interface (such as: 5G N5 / N30 interface, 4G Rx interface).

[0200] It should be noted that in the embodiment of the present invention, for the business scenario in which different mobile communication networks access external network identifiers (5G: DNN+S-NSSAI, 4G: APN) and reuse the user IP address pool, the mobile communication network access external network identifier (5G: DNN+S-NSSAI, 4G: APN) is used as an important part of the policy binding information, and is applied to the application function network element and the service channel to establish the interface between the control plane network element / policy binding network element, and the interface between the application function network element and the policy control network element (such as: 5G N5 / N30 interface, 4G Rx interface).

[0201] It should be noted that, in the embodiment of the present invention, the application function network element addresses the corresponding service channel by dynamic query to establish two technical implementations of the control plane network element / policy binding network element, including:

[0202] (1) The service channel establishment control plane network element / policy binding network element performs NF registration / NF update / NF deregistration to the NRF (or NRF / SCP) as a policy binding network element, and the information contained in the registration message; the policy binding information saved by the service channel establishment control plane network element / policy binding network element;

[0203] (2) The application function network element executes the policy-bound network element service discovery process and the information contained therein to the NRF (or NRF / SCP); the NRF (or NRF / SCP) matches the policy-bound network element according to the policy-bound network element registration information and includes the information in the policy-bound network element service discovery response message.

[0204] The method for addressing a policy control network element provided in an embodiment of the present invention is applicable to all existing service scenarios (applicable to 5G networks, 4G networks, and 4G / 5G converged core networks, and the technical solution proposed in the embodiment of the present invention can also be used or referred to in subsequent 6G mobile communication networks and future generations of mobile communication networks), and solves the following problems: (1) the technical problem of addressing the policy control network element by the application function network element in the service scenario where different DNN / APN services of the same / different user terminals UE reuse the same IP address (IPv4 private address or IPv6 address); (2) the technical problem of the same service channel Establish multiple service channels controlled by control plane network elements (such as SMF, SMF / PGW-C, PGW-C) and establish user plane network elements (such as UPF, UPF / PGW-U, PGW-U). For the same DNN / APN reuse IPv4 private address pool service scenario, the technical problem of application function network element addressing policy control network elements; (3) Policy binding network elements and their stored policy binding information, business processes occupy too many network resources, and complex network architecture; and simultaneously propose a method for application function network elements to automatically address policy binding network elements, which can simplify the data configuration of application function network elements.

[0205] The second aspect of the present invention provides a method for addressing a policy control network element, see Figure 4 As shown, it is a flowchart of a preferred embodiment of a policy control network element addressing method provided by the second aspect of the present invention, the method is applied to the control plane network element, and the method includes steps S21 to S25:

[0206] Step S21: after the user terminal accesses the mobile communication network, a user IP address is allocated to the user terminal, and a PCC process is initiated to the policy control network element with a device identifier of the control plane network element for the interface with the policy control network element corresponding to the user IP address pool; wherein, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools respectively, and N>1;

[0207] Step S22: receiving the PCC policy rules issued by the policy control network element, and saving the PCC policy session associated information of the service channel of the user terminal; wherein the information includes the device identification of the control plane network element, the user IP address, the mobile communication network access external network identification and the device identification of the policy control network element and the binding data therebetween;

[0208] Step S23: After the application function network element obtains the address of the control plane network element, the application function network element receives an address query request for the policy control network element currently responsible for the service channel PCC policy control of the user terminal service sent by the application function network element;

[0209] Step S24: query the binding data according to the address query request to obtain the address of the policy control network element;

[0210] Step S25: Send the query result of the address of the policy control network element to the application function network element.

[0211] In another preferred embodiment, the method further comprises:

[0212] Receive the PCC control policy issued by the policy control network element and execute the PCC control policy; wherein the PCC control policy is a PCC rule policy executed by the policy control network element on the service channel of the user terminal after receiving the policy application request sent by the application function network element, and the policy application request includes the IP address of the user terminal assigned by the control plane network element, the device identifier of the control plane network element and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0213] It should be noted that the addressing method of a policy control network element provided in the embodiment of the second aspect of the present invention, the specific implementation plan executed by the control plane network element and the technical effect achieved have been described in the above-mentioned embodiment of the first aspect and will not be repeated here.

[0214] The third aspect of the present invention also provides an application function network element, which is used to implement the addressing method of the policy control network element described in any embodiment of the first aspect, see Figure 5 FIG. 1 is a structural block diagram of a preferred embodiment of an application function network element provided by the third aspect of the present invention, wherein the application function network element includes:

[0215] The PCC policy control determination module 11 is used to determine the PCC policy control to be executed on the user terminal after the control plane network element establishes a service channel for the user terminal accessing the mobile communication network; wherein, during the establishment of the service channel, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools respectively, and N>1;

[0216] A first address acquisition module 12 is used to acquire the address of the control plane network element currently responsible for the user terminal service;

[0217] The first sending module 13 is used to send an address query request for the policy control network element currently responsible for the service channel PCC policy control of the user terminal service to the corresponding control plane network element according to the address of the control plane network element;

[0218] The first receiving module 14 is configured to receive a query result of the address of the policy control network element sent by the control plane network element.

[0219] Preferably, the application function network element further includes:

[0220] The second sending module is used to send a policy application request to the policy control network element according to the address of the policy control network element obtained from the query result; wherein the policy application request includes the IP address of the user terminal assigned by the control plane network element, the device identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0221] Preferably, the first address acquisition module 12 includes a first address acquisition unit, configured to:

[0222] By configuring local static data, configuring the local configuration information to a mapping table of the device address of the control plane network element; wherein the local configuration information includes the IP address of the user terminal assigned by the control plane network element, the IP address of the user terminal after address conversion, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal;

[0223] The mapping table of the device address of the control plane network element is queried according to the local configuration information to obtain the address of the control plane network element currently responsible for the user terminal service.

[0224] Preferably, the first address acquisition module 12 includes a second address acquisition unit, which is used to:

[0225] Obtaining service discovery query parameters; wherein the service discovery query parameters include the IP address of the user terminal assigned by the control plane network element, the mobile communication network access external network identifier corresponding to the service channel of the user terminal, and the domain name to which the IP address derived from the IP address of the user terminal after address conversion belongs;

[0226] Execute the control plane network element service discovery process to the network storage function according to the service discovery query parameter; wherein the registration information of the control plane network element to the network storage function includes the address of the control plane network element and the local device addressing identifier;

[0227] Receiving a service discovery response message sent by the network storage function based on the registration information, and acquiring an address of a control plane network element according to the service discovery response message;

[0228] Then, the address query request includes the IP address of the user terminal allocated by the control plane network element, the local device addressing identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0229] Preferably, the first address acquisition module 12 includes a third address acquisition unit, which is used to:

[0230] By configuring local static data, configuring the local configuration information to a mapping table of the device address of the control plane network element; wherein the local configuration information includes the IP address of the user terminal assigned by the control plane network element, the IP address of the user terminal after address conversion, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal;

[0231] Query the mapping table of the device address of the control plane network element according to the local configuration information to obtain the address of the control plane network element currently responsible for the user terminal service and the local device addressing identifier;

[0232] Then, the address query request includes the IP address of the user terminal allocated by the control plane network element, the local device addressing identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0233] It should be noted that an application function network element provided in the embodiment of the third aspect of the present invention can implement all the processes of the addressing method of the policy control network element described in any embodiment of the first aspect above. The functions of each module and unit in the application function network element and the technical effects achieved are respectively the same as the functions of the addressing method of the policy control network element described in the above embodiments and the technical effects achieved, and they will not be repeated here.

[0234] The fourth aspect of the present invention further provides a control plane network element, which is used to implement the addressing method of the policy control network element described in any embodiment of the second aspect, see Figure 6 FIG. 1 is a structural block diagram of a preferred embodiment of a control plane network element provided by the fourth aspect of the present invention, wherein the control plane network element includes:

[0235] The PCC process initiation module 21 is used to allocate a user IP address to the user terminal after the user terminal accesses the mobile communication network, and initiate the PCC process to the policy control network element with the device identifier of the control plane network element used for the interface between the policy control network element corresponding to the user IP address pool; wherein, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools respectively, and N>1;

[0236] The PCC association information storage module 22 is used to receive the PCC policy rules issued by the policy control network element, and save the PCC policy session association information of the service channel of the user terminal; wherein the information includes the device identification of the control plane network element, the user IP address, the mobile communication network access external network identification and the device identification of the policy control network element and the binding data therebetween;

[0237] A first receiving module 23 is used to receive an address query request 24 of a policy control network element for a service channel PCC policy control currently responsible for user terminal services, after the application function network element obtains the address of the control plane network element;

[0238] A first address acquisition module, configured to query the binding data according to the address query request to obtain the address of the policy control network element;

[0239] The first sending module 25 is used to send the query result of the address of the policy control network element to the application function network element.

[0240] Preferably, the control plane network element further includes:

[0241] The second receiving module is used to receive the PCC control policy issued by the policy control network element and execute the PCC control policy; wherein, the PCC control policy is a PCC rule policy executed by the policy control network element on the service channel of the user terminal after receiving the policy application request sent by the application function network element, and the policy application request includes the IP address of the user terminal allocated by the control plane network element, the device identifier of the control plane network element and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

[0242] It should be noted that a control plane network element provided in an embodiment of the present invention can implement all processes of the addressing method of the policy control network element described in any embodiment of the second aspect above. The functions of each module in the control plane network element and the technical effects achieved are respectively the same as the functions of the addressing method of the policy control network element described in the above embodiment and the technical effects achieved, and will not be repeated here.

[0243] The fifth aspect embodiment of the present invention also provides a computer-readable storage medium, which includes a stored computer program; wherein, when the computer program is running, it controls the device where the computer-readable storage medium is located to execute the addressing method of the policy-controlled network element described in any embodiment of the first and second aspects above.

[0244] The sixth aspect embodiment of the present invention also provides an application function network element, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the addressing method of the policy control network element described in any embodiment of the first aspect when executing the computer program.

[0245] The seventh aspect embodiment of the present invention also provides a control plane network element, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the addressing method of the policy control network element described in any embodiment of the second aspect when executing the computer program.

[0246] Preferably, the computer program can be divided into one or more modules / units (such as computer program 1, computer program 2, ...), and the one or more modules / units are stored in the memory and executed by the processor to complete the embodiment of the present invention. The one or more modules / units can be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program in the application function network element / the control plane network element.

[0247] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor. The processor is the control center of the application function network element / the control plane network element, and various interfaces and lines are used to connect various parts of the application function network element / the control plane network element.

[0248] The memory mainly includes a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function, etc., and the data storage area can store related data, etc. In addition, the memory can be a high-speed random access memory, or a non-volatile memory, such as a plug-in hard disk, a smart memory card (SmartMedia Card, SMC), a secure digital (Secure Digital, SD) card, and a flash card (Flash Card), etc., or the memory can also be other volatile solid-state storage devices.

[0249] In summary, the addressing method of a policy control network element, an application function network element, a control plane network element, and a computer-readable storage medium provided in the embodiments of the present invention have the following advantages compared with the existing 3GPP international standard BSF solution (including: an independent BSF solution, a BSF and PCF, UDR, NRF, SMF and other network element co-setting solution):

[0250] (1) The policy binding network element and the service channel establishment control plane network element are comprehensively set up (tightly coupled), and the generation and storage of policy binding information are completed in the normal business process of the interface between the service channel establishment control plane network element / policy binding network element and the policy control network element, without occupying the processing capacity of the policy control network element, nor the processing capacity and storage resources of the service channel establishment control plane network element / policy binding network element. (Note: Only in the technical solution of dynamic addressing of the policy binding network element by the application function network element, one binding information parameter and the overhead of the policy binding network element performing NF registration / NF update / NF deregistration to the NRF (or NRF / SCP) are added.) Thereby achieving: when the proportion of N7 / N30 / Rx interface business demand is low, the present invention will not cause waste of hardware and software resources and investment of the policy control network element and the service channel establishment control plane network element / policy binding network element; and will not increase the establishment time of the service channel requiring policy binding;

[0251] (2) Service channel establishment control plane network element / policy binding network element completes data configuration based on the multiple service channels it controls / administers and the multiple user IP addresses it reuses to establish user plane network elements; policy control network elements do not require additional data configuration, and the complexity of operation and maintenance does not increase;

[0252] (3) Through the flexible combination of DNN and S-NSSAI, it can simultaneously meet the business scenarios of the same / different users' different DNNs reusing IP addresses in the same network slice (same S-NSSAI);

[0253] (4) Business scenarios that can meet IPv6 address NAT / PAT conversion (such as ULCL scenarios for 5G SA);

[0254] (5) The network architecture and business processes are simpler;

[0255] (6) Able to meet 4G business scenarios.

[0256] Compared with the existing China Mobile BSF solution (SMF built-in BSF function solution), it has the following advantages:

[0257] (1) By introducing the mobile communication network access external network identifier (5G: DNN+S-NSSAI, 4G: APN) into the information sent by the application function network element to the policy control network element in the policy binding query information, it is possible to meet the business scenario where the same / different users with different (DNN+S-NSSAI) / APN services reuse the same IP address (IPv4 private address or IPv6 address);

[0258] (2) By means of the method of "the service channel control plane network element / policy binding network element configures N service channel establishment control plane network element device identifiers for the interface between the service channel establishment control plane network element and the policy control network element, and the device identifiers correspond to N reused user IP address pools respectively", the service scenario of multiple service channel establishment user plane network elements controlled / managed by the same service channel establishment control plane network element reuses user IP addresses is met;

[0259] (3) Two technical implementation methods are proposed for the application function network element to address the corresponding service channel through dynamic query to establish the control plane network element / policy binding network element, which simplifies the data configuration of the application function network element.

[0260] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for addressing a policy control network element, characterized in that: Applied to application function network elements, including: After the control plane network element establishes a service channel for a user terminal accessing the mobile communication network, the PCC policy control to be executed on the user terminal is determined; wherein, during the establishment of the service channel, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of N control plane network elements configured by the control plane network element correspond to N reused user IP address pools respectively, and N>1; Obtain the address of the control plane network element currently responsible for the user terminal service; Send an address query request for the policy control network element currently responsible for the PCC policy control of the service channel of the user terminal service to the corresponding control plane network element according to the address of the control plane network element; Receive the query result of the address of the policy control network element sent by the control plane network element.

2. The addressing method of the policy control network element according to claim 1, characterized in that: The method further comprises: According to the address of the policy control network element obtained from the query result, a policy application request is sent to the policy control network element; wherein the policy application request includes the IP address of the user terminal assigned by the control plane network element, the device identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

3. The addressing method of the policy control network element according to claim 1, characterized in that: The obtaining the address of the control plane network element currently responsible for the user terminal service includes: By configuring local static data, configuring the local configuration information to a mapping table of the device address of the control plane network element; wherein the local configuration information includes the IP address of the user terminal assigned by the control plane network element, the IP address of the user terminal after address conversion, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal; The mapping table of the device address of the control plane network element is queried according to the local configuration information to obtain the address of the control plane network element currently responsible for the user terminal service.

4. The addressing method of the policy control network element according to claim 1, characterized in that: The obtaining the address of the control plane network element currently responsible for the user terminal service includes: Obtaining service discovery query parameters; wherein the service discovery query parameters include the IP address of the user terminal assigned by the control plane network element, the mobile communication network access external network identifier corresponding to the service channel of the user terminal, and the domain name to which the IP address derived from the IP address of the user terminal after address conversion belongs; Execute the control plane network element service discovery process to the network storage function according to the service discovery query parameter; wherein the registration information of the control plane network element to the network storage function includes the address of the control plane network element and the local device addressing identifier; Receiving a service discovery response message sent by the network storage function based on the registration information, and acquiring an address of a control plane network element according to the service discovery response message; Then, the address query request includes the IP address of the user terminal allocated by the control plane network element, the local device addressing identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

5. The addressing method of the policy control network element according to claim 1, characterized in that: The obtaining the address of the control plane network element currently responsible for the user terminal service includes: By configuring local static data, configuring the local configuration information to a mapping table of the device address of the control plane network element; wherein the local configuration information includes the IP address of the user terminal assigned by the control plane network element, the IP address of the user terminal after address conversion, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal; Query the mapping table of the device address of the control plane network element according to the local configuration information to obtain the address of the control plane network element currently responsible for the user terminal service and the local device addressing identifier; Then, the address query request includes the IP address of the user terminal allocated by the control plane network element, the local device addressing identifier of the control plane network element, and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

6. A method for addressing a policy control network element, characterized in that: Applied to control plane network elements, including: After the user terminal accesses the mobile communication network, a user IP address is allocated to the user terminal, and a PCC process is initiated to the policy control network element with a device identifier of the control plane network element used for the interface with the policy control network element corresponding to the user IP address pool; wherein, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools respectively, and N>1; Receive the PCC policy rules issued by the policy control network element, and save the PCC policy session associated information of the service channel of the user terminal; wherein the information includes the device identification of the control plane network element, the user IP address, the mobile communication network access external network identification and the device identification of the policy control network element and the binding data therebetween; After the application function network element obtains the address of the control plane network element, it receives an address query request for the policy control network element for the service channel PCC policy control currently responsible for the user terminal service sent by the application function network element; querying the binding data according to the address query request to obtain the address of the policy control network element; The query result of the address of the policy control network element is sent to the application function network element.

7. The addressing method of the policy control network element according to claim 6, characterized in that: The method further comprises: Receive the PCC control policy issued by the policy control network element and execute the PCC control policy; wherein the PCC control policy is a PCC rule policy executed by the policy control network element on the service channel of the user terminal after receiving the policy application request sent by the application function network element, and the policy application request includes the IP address of the user terminal assigned by the control plane network element, the device identifier of the control plane network element and the mobile communication network access external network identifier corresponding to the service channel of the user terminal.

8. An application function network element, characterized in that: Used to implement the addressing method of the policy control network element according to any one of claims 1 to 5, the application function network element comprises: A PCC policy control determination module is used to determine the PCC policy control to be executed on the user terminal after the control plane network element establishes a service channel for the user terminal accessing the mobile communication network; wherein, during the establishment of the service channel, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools respectively, and N>1; A first address acquisition module, used to acquire the address of the control plane network element currently responsible for the user terminal service; A first sending module is used to send an address query request for a policy control network element currently responsible for the service channel PCC policy control of the user terminal service to the corresponding control plane network element according to the address of the control plane network element; The first receiving module is used to receive the query result of the address of the policy control network element sent by the control plane network element.

9. A control plane network element, characterized in that: For implementing the addressing method of the policy control network element according to claim 6 or 7, the control plane network element comprises: The PCC process initiation module is used to allocate a user IP address to the user terminal after the user terminal accesses the mobile communication network, and initiate the PCC process to the policy control network element with the device identifier of the control plane network element used for the interface between the policy control network element corresponding to the user IP address pool; wherein, when several user plane network elements controlled by the same control plane network element reuse the user IP address, the device identifiers of the N control plane network elements configured by the control plane network element correspond to the N reused user IP address pools respectively, and N>1; A PCC association information storage module is used to receive the PCC policy rules issued by the policy control network element, and save the PCC policy session association information of the service channel of the user terminal; wherein the information includes the device identification of the control plane network element, the user IP address, the mobile communication network access external network identification and the device identification of the policy control network element and the binding data therebetween; A first receiving module is used to receive an address query request for a policy control network element for a service channel PCC policy control currently responsible for user terminal services, sent by the application function network element after the application function network element obtains the address of the control plane network element; A first address acquisition module, configured to query the binding data according to the address query request to obtain the address of the policy control network element; The first sending module is used to send the query result of the address of the policy control network element to the application function network element.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program; wherein, when the computer program is run, it controls the device where the computer-readable storage medium is located to execute the addressing method of the policy control network element according to any one of claims 1 to 7.

11. An application function network element, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the addressing method of the policy control network element according to any one of claims 1 to 5 when executing the computer program.

12. A control plane network element, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the addressing method of the policy control network element as claimed in claim 6 or 7 when executing the computer program.

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