Communication method and apparatus, system, electronic device, storage medium and program product

Abstract

The present disclosure relates to the technical field of communication, and particularly provides a communication method and device, system, electronic device, storage medium and program product. In the present disclosure, a first PCF receives a first message from a session management function (SMF), the first message carrying first information related to a dual steering association relationship of a terminal, and stores the first information into a first network function. The technical solution provided by the present disclosure can solve the problem of selecting a multi-access session to the same PCF which cannot be solved by the single connection session establishment solution in the prior art, is simple and easy to implement, and is conducive to popularizing the multi-access solution on the basis of the existing network, playing the advantages of the multi-access solution, and improving the core resource efficiency of the operator.

Description

Technical Field

[0001] This disclosure relates to the field of communication technology, and in particular to a communication method and apparatus, system, electronic device, storage medium and program product. Background Technology

[0002] To optimize the coordination of various access methods and improve the efficiency of operators' core resources, multi-access projects have become one of the future development directions of networks. Among them, Dualsteer technology, also known as dual-steer technology, refers to a technology that accesses the network through two 3GPP links, and is also one of the key technologies for solving the problem of convergence and evolution of new and old networks.

[0003] In multi-access projects, when establishing Protocol Data Unit (PDU) sessions, multiple globally unique Subscription Permanent Identifiers (SUPIs) exist. If these SUPIs are to be connected to different networks, each SUPI needs to be registered and a PDU session established separately. Therefore, ensuring that the SMF (Security Management Function) of the PDU sessions for multiple SUPIs selects the same PCF (Programmable Component Function) is a problem that existing single-connection session establishment schemes cannot solve. Summary of the Invention

[0004] This disclosure is made in view of the above-mentioned problems. This disclosure provides a communication method and apparatus, system, electronic device, storage medium, and program product.

[0005] According to one aspect of this disclosure, a communication method is provided for use in a first policy control function (PCF), the method comprising:

[0006] Receive a first message from the Session Management Function (SMF), the first message carrying first information, the first information being related to the terminal's dual-direction association relationship;

[0007] Store the first information into the first network function.

[0008] According to one aspect of this disclosure, a communication method is provided for use in a first policy control function (PCF), the method comprising:

[0009] Receive a second message from the Session Management Function (SMF), the second message carrying second information, the second information being related to the terminal's dual-turnover association;

[0010] The second information is stored in the second network function.

[0011] According to one aspect of this disclosure, a communication method is provided for use in an SMF, the method comprising:

[0012] Receive a fourth message from the first AMF, the fourth message requesting the establishment of a PDU session for the first terminal, the fourth message carrying first information;

[0013] A first message is sent to the first PCF, the first message carrying the first information; wherein the first information is related to the dual-turn association relationship of the terminal.

[0014] According to one aspect of this disclosure, a communication method is provided for use in an SMF, the method comprising:

[0015] Receive a seventh message from the first AMF, the seventh message requesting the establishment of a PDU session for the first terminal, the seventh message carrying second information;

[0016] A second message is sent to the first PCF, the second message carrying the second information; wherein the second information is related to the dual-turn association relationship of the terminal.

[0017] According to another aspect of this disclosure, a communication device is provided, comprising:

[0018] The transceiver unit is used to receive a first message from the Session Management Function (SMF), the first message carrying first information, and the first information being related to the dual-direction association relationship of the terminal.

[0019] The processing unit is used to store the first information into the first network function.

[0020] According to another aspect of this disclosure, a communication device is provided, comprising:

[0021] The transceiver unit is used to receive a second message from the Session Management Function (SMF). The second message carries second information, which is related to the dual-direction association relationship of the terminal.

[0022] The processing unit is used to store the second information into the second network function.

[0023] According to another aspect of this disclosure, a communication device is provided, comprising:

[0024] The receiving unit is configured to receive a fourth message from the first access and mobility management function (AMF), the fourth message requesting the establishment of a PDU session for the first terminal, and the fourth message carrying first information;

[0025] The sending unit is used to send a first message to the first PCF, the first message carrying the first information; wherein the first information is related to the dual-direction association relationship of the terminal.

[0026] According to another aspect of this disclosure, a communication device is provided, comprising:

[0027] The receiving unit is configured to receive a seventh message from the first access and mobility management function (AMF), the seventh message requesting the establishment of a PDU session for the first terminal, and the seventh message carrying second information;

[0028] The sending unit is used to send a second message to the first PCF, the second message carrying the second information; wherein the second information is related to the dual-turn association relationship of the terminal.

[0029] According to another aspect of this disclosure, a communication system is provided, comprising:

[0030] PCF is used to implement the communication method performed by PCF in any embodiment;

[0031] SMF is used to implement the communication method performed by SMF in any embodiment.

[0032] According to another aspect of this disclosure, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the method described in any of the above embodiments.

[0033] According to another aspect of this disclosure, a computer-readable storage medium is provided that stores a computer program / instructions thereon, which, when executed by a processor, implement the methods described in any of the above embodiments.

[0034] According to another aspect of this disclosure, a computer program product is provided, including a computer program that, when executed by a processor, implements the methods described in any of the above embodiments.

[0035] As will be described in detail below, according to an embodiment of this disclosure, a communication method, apparatus, system, electronic device, storage medium, and program product provide a technical solution in which, during the establishment of a PDU session, if the terminal involves dual-direction technology, the AMF can carry information related to the dual-direction association of the terminal (specifically, first information or second information) in the message sent to the SMF. The SMF can also carry this information in the message sent to the PCF when selecting the PCF. Thus, the PCF can store this information in a designated network function (i.e., the first network function or the second network function). Therefore, during subsequent single-connection session establishment, if the SMF or PCF encounters a session establishment process related to the dual-direction association (e.g., carrying some or all of the information in the dual-direction association), it can accurately connect both sessions to the same PCF using the information stored in the designated network function. In this way, by additionally transmitting, storing, and querying the first or second information during the existing single-connection session establishment process, the problem of multiple access sessions selecting the same PCF, which is unsolvable by the single-connection session establishment scheme, can be solved. In summary, the technical solution provided in this disclosure can solve the problem of multiple access sessions selecting the same PCF, which cannot be solved by the existing single-connection session establishment scheme. It is simple and easy to implement, which is conducive to promoting and popularizing the multi-access scheme on the basis of the existing network, giving full play to the advantages of the multi-access scheme, and improving the efficiency of the operator's core resources.

[0036] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description

[0037] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0038] Figure 1 This is a flowchart illustrating a communication method provided in an embodiment of the present disclosure.

[0039] Figure 2 This is a flowchart illustrating another communication method provided in an embodiment of the present disclosure.

[0040] Figure 3 This is a flowchart illustrating another communication method provided in an embodiment of the present disclosure.

[0041] Figure 4This is a flowchart illustrating another communication method provided in an embodiment of the present disclosure.

[0042] Figure 5 This is a flowchart illustrating another communication method provided in an embodiment of the present disclosure.

[0043] Figure 6 This is a structural block diagram of a communication device provided in an embodiment of the present disclosure.

[0044] Figure 7 This is a structural block diagram of another communication device provided in an embodiment of the present disclosure.

[0045] Figure 8 This is a structural block diagram of another communication device provided in an embodiment of the present disclosure.

[0046] Figure 9 This is a structural block diagram of another communication device provided in an embodiment of the present disclosure.

[0047] Figure 10 This is a structural block diagram of a communication system provided in an embodiment of the present disclosure.

[0048] Figure 11 This is a hardware block diagram of an electronic device provided in an embodiment of the present disclosure.

[0049] Figure 12 This is a schematic diagram of a computer-readable storage medium provided in an embodiment of the present disclosure. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this disclosure more apparent, exemplary embodiments according to this disclosure will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this disclosure, and not all embodiments of this disclosure. It should be understood that this disclosure is not limited to the exemplary embodiments described herein.

[0051] The application scenario disclosed herein is a communication scenario involving multiple access technologies.

[0052] Specifically, multi-access technology refers to accessing a network through multiple links. In real-world scenarios, the networks accessed by different links in multi-access technology can generally be different. For example, one 3GPP link accesses a 5G network, and another 3GPP link accesses a 6G network. This disclosure does not impose any particular restrictions on the specific networks accessed by the terminal's multi-access technology. The network types (also referred to as network system types) involved in this disclosure may include, but are not limited to: Global System for Mobile communication (GSM) systems, Code Division Multiple Access (CDMA) systems, Wideband Code Division Multiple Access (WCDMA) systems, General Packet Radio Service (GPRS), Long Term Evolution (LTE) systems, Advanced Long Term Evolution (LTE-A) systems, New Radio (NR) systems, evolution systems of NR systems, LTE-based access to unlicensed spectrum (LTE-U) systems, NR-based access to unlicensed spectrum (NR-U) systems, Non-Terrestrial Networks (NTN) systems, Universal Mobile Telecommunication System (UMTS), and Wireless Local Area Networks (WLANs). Networks (WLAN), Wireless Fidelity (WiFi), 5th Generation (5G) systems, 6th Generation (6G) systems, or other communication systems, etc., are not exhaustive.

[0053] It should be noted that communication scenarios involving multiple access technologies can include standalone multiple access communication scenarios, as well as communication scenarios that may involve multiple access technologies within a single access scenario. For example, the PDU session establishment process can be a process where one user establishes a PDU session with a single access, or a process where some users establish PDU sessions with a single access, and some users establish PDU sessions using multiple access technologies such as DualSteer. Such mixed scenarios are also within the scope of this disclosure.

[0054] The dual-steering terminal involved in this disclosure can also be referred to as a terminal, terminal device, user equipment (UE), mobile station, mobile terminal, etc., possessing dual-steering capability and able to communicate with network-side devices. Specifically, dual-steering terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Based on this, dual-steering terminals can be, but are not limited to, mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc. This application does not impose any particular limitations on the specific technology or device form used in the terminal. Furthermore, the terminal can be fixed in location or mobile. The terminal can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on water; and it can also be deployed in the air on airplanes, balloons, and artificial satellites. This application embodiment does not impose any particular limitations on the application scenarios of the terminal.

[0055] Finally, it should be noted that the embodiments described above are all based on the DualSteer scheme. This disclosure can also be applied to other multi-access schemes in real-world scenarios, which will not be elaborated upon here.

[0056] For example, in this disclosure, the communication scenarios involving multiple access technologies may include, but are not limited to, the PDU session establishment scenario involving multiple access technologies. The multiple access technologies involved in this disclosure may include, but are not limited to, DualSteer (also known as dual-turnaround or other names, this disclosure has specific restrictions on naming) technology or other dual or multiple access technologies. For ease of explanation, the PDU session establishment process of a DualSteer terminal will be used as an example for detailed explanation below.

[0057] In related technologies, the PDU session establishment process for a single access user is already very mature. In 5G technology, the PDU session establishment process for a single access user includes: Session Management Function (SMF) selection and Policy Control Function (PCF) policy establishment. Specifically, after the Access and Mobility Management Function (AMF) determines the SMF to execute the session, it requests the SMF to create a session management context. The SMF responds and updates the terminal connection management information in the Unified Data Management (UDM). Afterwards, the SMF needs to initiate a policy control request to the PCF to establish the session management policy association. This involves the SMF selecting the PCF. In related technologies, the SMF can look up the PCF instance ID through the NRF. The PCF that receives the policy control request can respond to the SMF with the corresponding session management policy (SM policy) control information. Thus, the SMF can select the UPF based on the policy control information responded by the PCF.

[0058] However, as described in the background section of this disclosure, existing single-connection session establishment schemes cannot solve the problem of selecting the SMF of multiple SUPI PDU sessions to the same PCF.

[0059] To address the aforementioned issues, this disclosure provides a novel design concept: Building upon existing single-connection session establishment schemes, if a terminal involves a dual-direction association, this information can be carried within messages exchanged between the AMF, SMF, and PCF. The PCF can then store this information in a network function with storage capabilities, such as the UDM or Binding Support Function (BSF). Consequently, during subsequent single-connection session establishment, if identical or partially identical information is encountered, a dual-direction association can be determined, allowing direct selection of the same PCF or redirection to the same PCF via redirection. Thus, by additionally transmitting, storing, and querying the first or second information during the existing single-connection session establishment process, the problem of multiple access sessions selecting the same PCF, which is unsolvable by existing single-connection session establishment schemes, can be solved. In other words, this disclosure provides the following two solutions, which will be explained below using the PDU session establishment process as an example.

[0060] Option 1 is to implement this solution by storing the first information in the NRF.

[0061] This disclosure provides a communication method. Please refer to... Figure 1 , Figure 1 This is a flowchart illustrating a communication method provided in an embodiment of this disclosure. Figure 1 As shown, the method includes:

[0062] For SMF, it can include S102 and S104, which are explained in detail below.

[0063] S102, the SMF receives a fourth message from the first AMF. The fourth message requests the establishment of a PDU session for the first terminal and carries the first information.

[0064] In this disclosure, the first information may be information related to the terminal's dual-steer association relationship (also known as DualSteer association relationship). In other words, the first information can be used to indicate whether the terminal has a DualSteer association relationship, and / or, which terminals the terminal has a DualSteer association relationship with. For ease of understanding, if... Figure 1 The PDU session establishment process shown is for the first terminal. Therefore, the first information can specifically indicate whether the first terminal has a DualSteer association with other terminals, and / or, which terminal the first terminal specifically has a DualSteer association with. Possible implementations of the first information will be explained in detail later.

[0065] It should be understood that in a real-world scenario, if the first terminal has a DualSteer association (or is understood as the first terminal being a DualSteer terminal), then the fourth message will necessarily carry the first information; however, if the first terminal does not have a DualSteer association (or is understood as the first terminal not being a DualSteer terminal), then the fourth message may not carry the first information, or the first information may be empty, or the first information may indicate that the first terminal is not a DualSteer terminal.

[0066] In this disclosure, for any terminal (for ease of explanation, the first terminal is still used as an example), the process of establishing its PDU session involves two stages, as mentioned above: SMF selection and PCF policy establishment. During the SMF selection stage, the first AMF sends a session management context creation request message to the SMF. In addition, in this disclosure, the first AMF also sends a fourth message to the SMF, which carries the first information. Specifically, the fourth message can be a session management context creation request message or a separate message independent of it; there are no particular restrictions. Furthermore, how the first AMF selects the SMF and the related operations before selecting the SMF are not detailed here; refer to the single-connection PDU session establishment process. This disclosure can reuse relevant existing technologies without particular restrictions.

[0067] S104, the SMF sends a first message to the first PCF, the first message carrying first information; wherein, the first information is related to the dual-turn association relationship of the terminal.

[0068] For SMF, after receiving the fourth message, it is necessary to execute the PCF policy establishment process, which involves: selecting PCF and establishing session policy association.

[0069] Specifically, the first information can be used to specify the stage at which the SMF selects the PCF. Specifically, the SMF can query the first network function (which stores the DualSteer association information of each terminal, explained below) based on the first information to determine whether the current first terminal has a DualSteer association with other terminals. Then, by querying the first network function, if there is a terminal x with a DualSteer association with the first terminal in the information maintained by the first network function (for example, the first information carried by the first terminal is part or all of the relevant information of terminal x maintained by the first network function), and the PCF selected by terminal x is the first PCF, then the SMF can directly select the same first PCF for the first terminal to ensure that two terminals with a DualSteer association can select the same PCF. Alternatively, if no terminal with an association with the first terminal is found, then the SMF can select the PCF for the first terminal's PDU session in any way based on its own policies or rules, which will not be elaborated further.

[0070] Regardless of the strategy by which the SMF selects the PCF, the PCF selected by the SMF is denoted as the first PCF. The first message sent by the SMF to the first PCF can carry the first information.

[0071] Based on the selected first PCF, when the SMF sends a session policy association request (i.e., the first message) to the selected PCF, it will include the first information in the first message so that the PCF can store the first information in the first network function. In this way, in subsequent processing scenarios, the SMF can obtain information related to the DualSteer association of each terminal from the first network function. Furthermore, the SMF can also select a PCF or perform other processing based on the first information and the information stored in the first network function.

[0072] For PCF, it can include S106 and S108, as detailed below.

[0073] S106, the first PCF receives the first message from the SMF. The first message carries first information, which is related to the dual-turn association relationship of the terminal.

[0074] S108, the first PCF stores the first information into the first network function.

[0075] For the first PCF, upon receiving the first message from the SMF, it can use this message to send back session management policy (SM policy) control information to the SMF, thereby achieving session policy association with the first terminal. Further details are omitted.

[0076] In addition, the first PCF also stores the first information into the first network function. Therefore, the first network function can store the terminal's first information. It should be understood that different terminals can all store the first information according to this... Figure 1 The PDU session is established in the manner shown. Therefore, the first network function can store the first information of each terminal. In other words, the first network function maintains the DualSteer association information of each terminal establishing a PDU session. This information can be applied to any step in any PDU session establishment process after this step. Specifically, it can be applied to the subsequent PCF selection step. For details on the implementation, please refer to the relevant explanation in S104 above.

[0077] In summary, during the establishment of a PDU session, if the terminal involves dual-direction technology, the AMF can carry first information related to the dual-direction association of the terminal in the message sent to the SMF. The SMF can also carry this first information in the message sent to the PCF when selecting it. Thus, the PCF can store this first information in the first network function. Therefore, during subsequent single-connection session establishment, if a session establishment process related to the dual-direction association is encountered (e.g., carrying some or all of the information in the dual-direction association), the SMF can accurately connect both sessions to the same PCF using the information stored in the first network function. In this way, by additionally transmitting, storing, and querying the first information during the existing single-connection session establishment process, the problem of multiple access sessions selecting the same PCF, which is unsolvable by single-connection session establishment schemes, can be solved. This is simple and easy to implement, conducive to promoting and popularizing multi-access schemes on the existing network foundation, leveraging the advantages of multi-access schemes, and improving the efficiency of operators' core resources.

[0078] In this disclosure, the first piece of information relates to the DualSteer association relationship of the terminals. As described above and in the background section, the DualSteer association relationship refers to the association relationship between two terminals (or two users of a DualSteer terminal) accessing the network via dual 3GPP links. For two terminals with a DualSteer association relationship, their two PDU session establishment processes can also be regarded as two single access session establishment processes. In these two single access processes, such as... Figure 1 As shown, the SMF transmits the first information to the first PCF, and the first PCF stores the first information in the first network function, so that the subsequent SMF can select the PCF accordingly. This ensures that terminals with DualSteer association can select the same PCF.

[0079] Based on this, the first information may specifically include, but is not limited to, at least one of the following:

[0080] The first identifier of the first terminal is SUPI1;

[0081] The second identifier of the second terminal is SUPI2;

[0082] Associated identifier;

[0083] The first PDU session ID of the first terminal;

[0084] The second PDU session ID of the second terminal;

[0085] Associated session ID.

[0086] The association identifier is used to indicate that the first terminal and the second terminal have a bidirectional association relationship.

[0087] For example, an association identifier can indicate that a terminal has a DualSteer association (or can be understood as indicating that the terminal is a DualSteer terminal), for instance, represented by a specified character. In this case, the association identifier has no indicative effect on another terminal with a DualSteer association with that terminal; it is a non-specific, uniform identifier. Alternatively, the association identifier can be used to indicate that a terminal has a DualSteer association with another specific terminal. In this case, the association identifier indicates the specific two terminals; it is a specific, targeted identifier. In practical scenarios, specific identifiers can be added to the DualSteer associations between different terminals to represent the DualSteer associations between different terminals. For example, identifier A is used to indicate that terminal 1 and terminal 2 have a DualSteer association, and identifier B is used to indicate that terminal 3 and terminal 4 have a DualSteer association. Thus, based on these DualSteer association identifiers, it is possible to determine which terminals have a DualSteer association.

[0088] In one exemplary embodiment, the association identifier can be a Dualsteer association ID (i.e., a DualSteer association identifier), or it can be a Dualsteer dundle ID, or it can be a Dualsteercorrelation ID, used to indicate that the first terminal and the second terminal are a pair of Dualsteer terminals.

[0089] The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

[0090] Similar to the association identifier, the associated session ID is used to indicate the DualSteer association between sessions. This indication can be a specific identifier or a non-specific identifier, as described above. In one exemplary embodiment, the associated session ID is the Dualsteer Session ID, which is assigned by SMF to the Dualsteer PDU Session. The associated session IDs of two associated PDU sessions are the same.

[0091] It should be understood that the first piece of information can specifically include one or more of the information mentioned above, and there are multiple ways to implement it in real-world scenarios:

[0092] In one exemplary implementation, for the first terminal (denoted as UE1), the first information carried during the establishment of a PDU session by the first terminal can specifically include: SUPI1, SUPI2, and a DS association identifier (or DualSteer association identifier, DS association ID, etc.); wherein, SUPI1 is the identifier of UE1, SUPI2 is the identifier of the second terminal (denoted as UE2), and the DS association identifier can be a non-specific unified identifier or a specific identifier pointing to UE1 and UE2. This first information is used to indicate that there is a DualSteer association relationship between UE1 and UE2.

[0093] In another exemplary implementation, for UE1, the first information carried during the establishment of the PDU session by the first terminal can specifically be: SUPI1 and DS association identifier, where SUPI1 is the identifier of UE1, and the DS association identifier can be a specific pointing identifier, such as identifier C, which is specifically used to indicate that there is a DualSteer association relationship between UE1 and UE2. Thus, this first information can also be used to indicate that there is a DualSteer association relationship between UE1 and UE2.

[0094] In another exemplary implementation, for UE1, the first information carried during the establishment of the PDU session by the first terminal can specifically be: a DS association identifier, wherein the DS association identifier can be a specific pointing identifier, such as identifier C, which is specifically used to indicate that there is a DualSteer association relationship between UE1 and UE2. Thus, this first information can also be used to indicate that there is a DualSteer association relationship between UE1 and UE2.

[0095] In another exemplary implementation, for UE1, the first information carried during the establishment of the PDU session by the first terminal can specifically be SUPI1 and SUPI2; wherein SUPI1 is the identifier of UE1, and SUPI2 is the identifier of the second terminal (denoted as UE2). This first information can be used to indicate that there is a DualSteer association relationship between UE1 and UE2.

[0096] In another exemplary implementation, for UE1, the first information carried during the establishment of the PDU session by the first terminal can specifically be: SUPI2; where SUPI2 is the identifier of the second terminal (denoted as UE2). That is, by carrying only the identifier of other terminals that have a DS association relationship with itself, it can be indicated that there is a DualSteer association relationship between the two. In other words, this first information can also be used to indicate that there is a DualSteer association relationship between UE1 and UE2.

[0097] The examples above are merely illustrative and can be applied to any second terminal or other terminal. Furthermore, since the examples only use the terminal and associated identifier, it should be understood that there are many possible implementations of the session identifier (i.e., session ID) and associated session identifier (i.e., associated session ID), as described above, which will not be elaborated upon. Additionally, considering that with technological advancements, a terminal may have multiple PDU sessions, the first information can also be combined and indicated using the terminal and / or session methods. This will not be elaborated upon further.

[0098] In summary, for any given terminal, the first information can take many forms, and custom conventions can be used in actual scenarios. This disclosure does not impose any special restrictions on this.

[0099] Furthermore, in the specific implementation of this scheme, when the first terminal registers with the network through the first AMF, the aforementioned first information can also be stored in the UDM. For example, when UE1 registers with the network through AMF1, SUPI1, SUPI2, and DS association ID can all be placed in the UDM.

[0100] In this embodiment of the disclosure, the first network function is any network function with information storage capability, and the PCF has at least the ability to write to the first network function, and the SMF has at least the ability to query (or read) the first network function.

[0101] In one possible embodiment, the first network function involved in this disclosure may be specifically a Network Repository Function (NRF).

[0102] The Network Request Function (NRF) serves as the network repository function in the core network, supporting service discovery and enabling the management of various Network Functions (NFs) and NF configuration files. Specifically, in PDU session establishment scenarios, the NRF can also be used to maintain the registration information of PCFs used during PDU session establishment. Therefore, in this embodiment, the first information can be maintained and stored as the PCF's registration information.

[0103] Thus, the specific implementation of the first PCF storing the first information in the first network function can be achieved as follows: the first PCF updates its registration information in the first network function based on the first information; wherein, the registration information includes the first information. In other words, after receiving the first information, the first PCF updates its registration information in the NRF based on that first information.

[0104] For NRF, this is equivalent to maintaining the terminal's DualSteer association information in the PCF registration information. Furthermore, based on... Figure 1In the embodiments shown, the content of the first information transmitted by different terminals or sessions may be different, and the DualSteer association information of the terminals maintained by the NRF may not be completely the same.

[0105] In this disclosure, a first network function is used to provide first information to the SMF so that the SMF can select the same PCF for dual-steering terminals.

[0106] To provide a clearer understanding of this solution, the embodiments disclosed herein further provide... Figure 1 This illustrates a possible follow-up processing flow after the illustrated process. Please refer to [the relevant documentation / reference]. Figure 2 , Figure 2 This is a flowchart illustrating another communication method provided in an embodiment of this disclosure. Figure 2 As shown, the method includes Figure 1 In addition to S102 to S108 shown, the method also includes the following steps:

[0107] S110, the SMF receives a fifth message from the second AMF, the fifth message requests the establishment of a PDU session for the second terminal; the fifth message carries fifth information, which is all or part of the first information.

[0108] In practice, the fifth message is similar to the first message; it can be a request to establish a PDU session for the second terminal, or it can be a separate message. The AMF used by the first and second terminals to establish the PDU session can be different; that is, the first AMF and the second AMF can be the same or different. Furthermore, based on related technologies, terminals with DualSteer association can choose to access the same SMF when establishing a PDU session. This disclosure does not impose any special restrictions on this technology and will not elaborate further.

[0109] The fifth information carried in the fifth message, similar to the first information, can be all or part of the fifth information. That is, the fifth information can be: the first identifier SUPI1 of the first terminal, the second identifier SUPI2 of the second terminal, the associated identifier, the first PDU session ID of the first terminal, the second PDU session ID of the second terminal, and all or part of the associated session ID. The specific meanings are the same as before and will not be repeated. In actual implementation scenarios, if the second terminal is also considered as an independent... Figure 1 In the single access session establishment process shown, the second terminal is equivalent to the first terminal, and the fifth information can also be equivalent to the first information.

[0110] S112, SMF queries the first PCF corresponding to the fifth information in the first network function.

[0111] SMF queries the first network function to determine if there is information matching the fifth information in the information stored in the first network function. If so, the terminal has a DualSteer association with the current terminal, and the first PCF selected by the terminal is determined as the PCF of the second terminal. In such cases... Figure 2 In the embodiment shown, the first network function stores the registration information of the first PCF. The registration information includes first information, which may specifically be information that the first terminal and the second terminal have a DualSteer association relationship. In this way, the SMF can query the first PCF that matches the second information in the first network function. Therefore, the PCF selected by the SMF for the second PDU session of the second terminal is the first PCF, and the subsequent S114 is executed.

[0112] S114, the SMF sends a sixth message to the first PCF, which requests policy association. Based on this, the SMF can select the same first PCF for two terminals with DualSteer association by querying the information stored in the first network function, thus solving the problem of selecting multiple access sessions to the same PCF.

[0113] In addition, such as Figure 2 In the illustrated embodiment, after receiving the sixth message, the first PCF can send an SMpolicy response to the SMF, which will not be elaborated further. Furthermore, after receiving the sixth message, the first PCF can also store the fifth information into the first network function, i.e., store (or update) the registration information of the first PCF. Alternatively, if the first information and the fifth information are completely identical, no update or storage operation is required; any design can be customized based on the actual situation.

[0114] To illustrate this solution more clearly, this disclosure also provides a possible embodiment. Please refer to... Figure 3 , Figure 3 This is a flowchart illustrating a communication method provided in an embodiment of this disclosure. Figure 3 As shown, the method includes:

[0115] S1, UE1 (or SUPI1, i.e., the first terminal) registers with the network through AMF1 (i.e., the first AMF).

[0116] In the specific implementation process, AMF1 can store SUPI1, SUPI2 and DS association ID (i.e. the first information of Scheme 1, or information related to the dual-turn association relationship of the terminal) into UDM.

[0117] S2, UE1 establishes a PDU session through SMF.

[0118] During this process, the SMF selects PCF1 (i.e., the first PCF) for policy association and carries SUPI1, SUPI2 and DS association identifiers (i.e., the first information) in the policy association request message sent to PCF1 (i.e. the first message mentioned above).

[0119] After receiving the first message, PCF1 stores the relevant information of its service SUPI1 (such as the association between SUPI1 and SUPI2) in the NRF. In a more specific implementation, PCF1 can update its registration information in the NRF (i.e., the first network function) (that is, write the first information into the NRF).

[0120] S3, UE2 (i.e., the second terminal, or SUPI2) registers with the network through AMF2 (i.e., the second AMF).

[0121] S4, UE2 establishes a PDU session through the SMF, that is, AMF2 selects the same SMF as UE1 and initiates a PDU session establishment request (i.e., the fifth message) to the SMF. This request carries SUPI2 and DS association ID (i.e., the fifth information, in this embodiment, the fifth information is part of the first information).

[0122] S5, SMF finds PCF1 from NRF and establishes a session policy association.

[0123] In practice, the SMF can send a query request to the NRF, carrying SUPI1, SUPI2 and DS association ID. Based on the information stored in the NRF, it can know that SUPI1 and SUPI2 have a DualSteer association relationship, and SUPI1 selects PCF1 (because this information is stored in PCF1's registration information). In this way, the SMF can find PCF1 in the NRF, and then establish a session policy association with PCF1 and establish a PDU session. This will not be elaborated further.

[0124] In summary, in the Scheme 1 provided by this disclosure, during the existing single-connection session establishment process, the first information involving the DualSteer association relationship is additionally stored in the first network function (e.g., NRF). The SMF can ensure that all DualSteer associated terminals access the same PCF by querying the stored information, thus solving the problem that the existing single-connection session establishment scheme cannot solve, where multiple access sessions select the same PCF. It is simple and easy to implement, which is conducive to promoting and popularizing multi-access schemes on the basis of existing networks, giving full play to the advantages of multi-access schemes, and improving the efficiency of operators' core resources.

[0125] Option 2 is to implement this solution by storing the first information in the BSF.

[0126] This disclosure provides another communication method. Please refer to... Figure 4 , Figure 4 This is a flowchart illustrating another communication method provided in an embodiment of this disclosure. Figure 4 As shown, the method includes:

[0127] For SMF, it can include S402 and S404, as explained below.

[0128] S402, the SMF receives the seventh message from the first AMF. The seventh message requests the establishment of a PDU session for the first terminal and carries the second information.

[0129] In this embodiment, SMF, first AMF, and first PCF can specifically refer to the core network elements involved in the establishment process of the first PDU session of the first terminal; SMF, second AMF, and second PCF can specifically refer to the core network elements involved in the establishment process of the second PDU session of the second terminal.

[0130] Furthermore, the seventh message in this embodiment (Scheme 2) has the same meaning and possible implementation as the first message in Scheme 1 above. The seventh message can specifically be that the first AMF sends a session management context creation request message to the SMF, or it can be another message independent of the session management context creation request message, which will not be elaborated further. In addition, the second information in Scheme 2 is the same as the first information in Scheme 1 above, and the DualSteer association in Scheme 2 is the same as the DualSteer association in Scheme 1 above. The different terms are only used to distinguish different embodiments, but their meanings and implementations are the same as in Scheme 1, and can be referred to above, which will not be elaborated further.

[0131] S404, the SMF sends a second message to the first PCF, the second message carrying second information; wherein, the second information is related to the dual-turn association relationship of the terminal.

[0132] For the SMF, during the PDU session establishment process, it is still necessary to perform the process of selecting a PCF and establishing a session policy association. In this embodiment, when the SMF establishes the session policy association, it still needs to send information related to the dual-direction association relationship with the terminal (i.e., the second information) to the first PCF. However, in the PCF selection stage, the implementation method differs from that of Scheme 1. The selection of PCF1 and PCF2 can be implemented by referring to any implementation method in related technologies. This is because, in this embodiment, PCF2 is not required to be the same as PCF1. Therefore, the SMF can freely select PCF1 and PCF2 according to any policy or rule. In this embodiment, this disclosure does not impose any special restrictions on how the SMF selects PCFs (including PCF1 and PCF2). As for how to select the two onto the same PCF, it is achieved by redirecting the PCF, which will be explained in detail later.

[0133] For PCF, it can include S406 and S408, as detailed below.

[0134] S406, the first PCF receives a second message from the session management function SMF. The second message carries second information, which is related to the terminal's dual-turn association relationship.

[0135] S408, the first PCF stores the second information into the second network function.

[0136] For the first PCF, upon receiving the first message from the SMF, it can use this message to send back session management policy (SM policy) control information to the SMF, thereby achieving session policy association with the first terminal. Further details are omitted.

[0137] In addition, the first PCF also stores the second information in the second network function. Therefore, the second network function can store the terminal's second information. It should be understood that different terminals can all store the second information according to this... Figure 4 The method shown illustrates how a PDU session can be established. Therefore, the second network function can store the second information of each terminal; in other words, the second network function maintains the DualSteer association information of each terminal establishing a PDU session. This information can be applied to any step in any subsequent PDU session establishment process, specifically to the subsequent PCF redirection step. PCF redirection refers to the process where, when any PCF (taking PCF1, currently accessed by the first terminal, as an example) accesses the network, PCF1 can query the second network function to determine if there are other PCFs with a DualSteer association with the first terminal that have already been accessed. If there is a terminal x with a DualSteer association with the first terminal and terminal x has already been accessed by PCFx, then PCF1 can trigger a redirection operation to redirect the first terminal to PCFx, ensuring that two terminals with a DualSteer association can access the same PCF (i.e., PCFx).

[0138] In summary, during the establishment of a PDU session, if the terminal involves dual-direction technology, the AMF can carry second information related to the dual-direction association of the terminal in the message sent to the SMF. The SMF can also carry this second information in the message sent to the PCF after selecting it. Thus, the PCF can store this second information in the second network function. Therefore, during the subsequent establishment of a single-connection session, the SMF can arbitrarily select a PCF. The PCF can determine whether it matches the PCF already connected to by the dual-direction associated terminal by querying the data stored in the second network function. If they do not match, it is redirected to the PCF already connected to by the dual-direction associated terminal. This ensures that both sessions are accurately connected to the same PCF. Thus, by simply transmitting, storing, and querying the second information additionally during the existing single-connection session establishment process, the problem of multiple access sessions selecting the same PCF, which is unsolvable by the single-connection session establishment scheme, can be solved. This is simple and easy to implement, conducive to promoting and popularizing multi-access schemes on the existing network foundation, leveraging the advantages of multi-access schemes, and improving the efficiency of operators' core resources.

[0139] For example, the second information involved in this disclosure may include, but is not limited to, at least one of the following:

[0140] The first identifier of the first terminal is SUPI1;

[0141] The second identifier of the second terminal is SUPI2;

[0142] Associated identifier;

[0143] The first PDU session ID of the first terminal;

[0144] The second PDU session ID of the second terminal;

[0145] Associated session ID.

[0146] In another exemplary embodiment, the association identifier in this disclosure is used to indicate that the first terminal and the second terminal have a bidirectional association relationship.

[0147] For example, an association identifier can indicate that a terminal has a DualSteer association (or can be understood as indicating that the terminal is a DualSteer terminal), for instance, represented by a specified character. In this case, the association identifier has no indicative effect on another terminal with a DualSteer association with that terminal; it is a non-specific, uniform identifier. Alternatively, the association identifier can be used to indicate that a terminal has a DualSteer association with another specific terminal. In this case, the association identifier indicates the specific two terminals; it is a specific, targeted identifier. In practical scenarios, specific identifiers can be added to the DualSteer associations between different terminals to represent the DualSteer associations between different terminals. For example, identifier A is used to indicate that terminal 1 and terminal 2 have a DualSteer association, and identifier B is used to indicate that terminal 3 and terminal 4 have a DualSteer association. Thus, based on these DualSteer association identifiers, it is possible to determine which terminals have a DualSteer association.

[0148] In one exemplary embodiment, the association identifier can be a Dualsteer association ID (i.e., a DualSteer association identifier), or it can be a Dualsteer dundle ID, or it can be a Dualsteercorrelation ID, used to indicate that the first terminal and the second terminal are a pair of Dualsteer terminals.

[0149] The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

[0150] Similar to the association identifier, the associated session ID is used to indicate the DualSteer association between sessions. This indication can be a specific identifier or a non-specific identifier, as described above. In one exemplary embodiment, the associated session ID is the Dualsteer Session ID, which is assigned by SMF to the Dualsteer PDU Session. The associated session IDs of two associated PDU sessions are the same.

[0151] In another exemplary embodiment, the associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

[0152] Furthermore, please refer to Scheme 1 above for explanations of the associated identifier and associated session ID, which will not be repeated here. The format of the second piece of information is the same as that of the first piece of information in Scheme 1 above, and will not be repeated here.

[0153] In this embodiment of the disclosure, the second network function is any network function with information storage capability, and the PCF has at least the ability to write to and query (or read from) the first network function.

[0154] Furthermore, in the specific implementation of this scheme, when the first terminal registers with the network through the first AMF, it can also store its relevant second information in the UDM. For example, when UE1 registers with the network through AMF1, it can put SUPI1, SUPI2, and DS association ID in the UDM.

[0155] In one possible embodiment, the first network function involved in this disclosure may be specifically a Binding Support Function (BSF).

[0156] BSF (Binding Support Function) is a binding support function in the core network, also known as binding function or session binding support function; there are no particular restrictions on the name. In the core network, BSF is mainly responsible for implementing session binding between N7 and N5 ports, so that different sessions select the same PCF (Personalized Service Provider). This aligns with the technical objective of this disclosure and can be implemented using existing BSF network elements.

[0157] Specifically, the first PCF stores the second information in the second network function, which can be further described as follows: the first PCF associates its identifier with the second information and stores it in the second network function. For example, in a practical implementation scenario, if the second information is an association identifier of SUPI1, SUPI2, and DS, then in this step, the first PCF can store PCF1 (i.e., the identifier of the first PCF), SUPI1, SUPI2, and the DS association identifier together in the BSF. The storage method is not limited; any method that can reflect the association between the two is acceptable. For example, it can include, but is not limited to, key-value storage, table storage, or storing it as a single piece of information. In this way, in subsequent applications, the relationship between the first PCF and the second information can be uniquely determined through this stored information.

[0158] Based on this, the second network function is used to provide association information for the second PCF, so that the second PCF can redirect the policy association request when the PCFs of the two-way terminals are inconsistent. The association information is the association information between the identifier of the first PCF and the second information. Specifically, the second PCF is the PCF selected by the SMF for the second PDU session of the second terminal.

[0159] In specific implementation, in addition to the aforementioned, Figure 4 In addition to the session establishment process for the first PCF, the process may also include a session establishment process for the second PCF. Specifically, for the first terminal, the SMF selects the first PCF and sends second information to it. The first PCF then associates the second information with itself and stores it in the BSF. Next, for the second terminal, the SMF can select the second PCF (selection rules or logic are not limited and consistency is not required), and send a policy association request to the second PCF carrying the second information. At this point, the second PCF can query the BSF (i.e., the second network function) to see if a PCF corresponding to the second information exists, thus retrieving the first PCF from the BSF. If the second PCF is inconsistent with the first PCF, the second PCF can send a redirection request to the SMF based on this inconsistency, so that the SMF redirects the second terminal's PCF to the first PCF, ensuring that two terminals with a DualSteer association can select the same PCF.

[0160] In a further possible embodiment, the UDM stores the second information stored during the registration of the first terminal. Therefore, before sending a policy association request to the second PCF, the SMF can query the UDM to see if the second terminal has a DualSteer association relationship. This allows the second information from the registration information of the first terminal to be retrieved, confirming a DualSteer association relationship between the two terminals. In this case, the policy association request sent by the SMF to the second PCF can include the second information. This allows the second PCF to query the BSF based on the received second information, triggering redirection processing when PCFs are inconsistent. Alternatively, if the SMF does not find the second information related to the second terminal, it does not need to include the second information in the policy association request sent to the second PCF, and the second PCF does not need to interact with the BSF or perform redirection processing after receiving the policy association request.

[0161] Furthermore, when the first PCF serves as the PCF for the PDU session of a subsequently accessed DualSteer associated terminal, after receiving the aforementioned second message, the first PCF can query the second network function for the PCF corresponding to the second information. If the queried PCF is inconsistent with the first PCF, the first PCF can initiate a redirection request to the SMF so that the SMF can redirect the PDU session of the first terminal to the queried PCF, thereby ensuring that the PCFs of the DualSteer associated terminals are consistent.

[0162] It should be understood that in actual implementation scenarios, any PCF can serve as either the first or second PCF mentioned above, depending on the specific application scenario. For example, in one possible embodiment, PCF1 can serve as the PCF of UE1, storing the second information related to UE1 in the BSF for UE2 (which has a DualSteer association with UE1 and accesses the network after UE1) to query and redirect if inconsistent. Alternatively, PCF1 can also serve as the PCF of UE3, and before performing specific policy association, query the BSF to determine whether there is a PCF for UE4 (which has a DualSteer association with UE3 and accesses the network before UE3), and if UE4's PCF is inconsistent with its own, trigger redirection processing.

[0163] To better understand this scheme, let's take the case where the first PCF is selected by the later-accessing terminal in a DualSteer setup as an example to illustrate how redirection processing is performed. For clarity, let's consider a third terminal (UE3) and a fourth terminal (UE4) with a DualSteer association. UE4 first accesses the network through the third PCF. The third PCF stores UE4's fourth information (e.g., SUPI3, SUPI4, and DS association ID) along with the third PCF's identifier (e.g., PCF3) in the BSF. Subsequently, when UE3 accesses the network through the SMF, the SMF selects the first PCF for UE3's PDU session establishment process and sends a third message to the first PCF. This third message requests policy association and carries third information related to the terminal's dual-redirection association.

[0164] The third message may include, but is not limited to, at least one of the following:

[0165] The third identifier of the third terminal is SUPI3;

[0166] The fourth identifier of the fourth terminal is SUPI4;

[0167] Associated identifier;

[0168] The third terminal's third PDU session ID;

[0169] The fourth PDU session ID of the fourth terminal;

[0170] Associated session ID.

[0171] In addition, the fourth information may include, but is not limited to, one or more of the above-mentioned SUPI3, SUPI4, associated identifier, third PDU session ID, fourth PDU session ID, and associated session ID.

[0172] Please refer to the previous text for similar concepts, which will not be repeated here.

[0173] At this point, the first PCF can process the following: The first PCF receives a third message from the SMF. This third message is used to request policy association and carries third information; the third information is related to the terminal's dual-direction association relationship. Then, the first PCF queries the second network function for the PCF corresponding to the third information (referred to as the third PCF for ease of explanation). Therefore, when the third PCF is inconsistent with the first PCF, the first PCF redirects the third message to the third PCF.

[0174] In other words, the first PCF can query the BSF to determine the PCF selected by the terminal that has a DualSteer association with the third terminal. If the two are inconsistent, the PCF of the later-connected terminal will be redirected and modified to keep them consistent.

[0175] In practice, the third and fourth information can be processed differently depending on the content they contain.

[0176] In one exemplary embodiment, if the fourth information stored in the second network function completely stores the specific identifiers and relationships of the two terminals (or sessions), for example, if the BSF stores: SUPI3, SUPI4, DS association ID (i.e., the fourth information completely stores the indication information of the two terminals) and PCF3, then the third information, whether complete or partial (for example, if the third information only contains the SUPI3 of the third terminal), can be directly queried from the second network function to see if there is a PCF corresponding to the third information, and if it exists, it can be further queried to see which PCF corresponds to the third information.

[0177] In another exemplary embodiment, if the fourth information stored in the second network function is incomplete, containing only information about a single terminal (e.g., PCF3 and SUPI4 in the BSF), then the BSF does not store which terminal has a DualSteer association with SUPI4. In this case, if the third information only contains SUPI3, the first PCF cannot find an accurate result in the second network function. In this situation, before querying the second network function, the first PCF needs to pre-query the identifiers of terminals associated with itself (e.g., SUPI4 in this example), and then find an accurate result in the second network function accordingly. This can be achieved using a UDM, which, as mentioned above, stores information about the DualSteer associations of terminals written during terminal registration.

[0178] In this embodiment, the first PCF queries the third PCF corresponding to the third information in the second network function, which can be achieved as follows: First, the first PCF queries the fourth information of the fourth terminal based on the third information. The fourth information includes at least one of the following: the fourth identifier SUPI4 of the fourth terminal and an associated identifier. Then, the first PCF queries the third PCF in the second network function based on the fourth information. For example, if the first PCF is for the PDU session establishment process of the third terminal, then the first PCF can query the UDM for SUPI4 (and / or associated identifier) ​​that has a DualSteer relationship with SUPI3 based on SUPI3. Thus, the first PCF can query the second network function for the PCF corresponding to SUPI4 based on SUPI4, thereby accurately finding PCF3.

[0179] It should be understood that this implementation method can also be applied to other embodiments. That is, in order to ensure the accuracy of the query results in the second network function, the first PCF can perform a query for the DualSteer association in the UDM in advance before querying the second network function, so as to query based on more accurate query results, such as the identifier of another terminal with the DualSteer association.

[0180] After the third PCF is found, if the first PCF and the third PCF are inconsistent, redirection is required; otherwise, if they are consistent, the first PCF reports the session association policy (SM Policy) to the SMF.

[0181] In this disclosure, the PCF acts only as the initiator (or trigger) of the redirection, with the SMF ultimately handling the redirection.

[0182] In one exemplary embodiment, for the first PCF, redirection can be implemented in the following manner: the first PCF sends a redirection request to the SMF, the redirection request carrying the identifier of the third PCF, so that the SMF can send the third message to the third PCF.

[0183] For example, a redirect request can be specifically an HTTP redirect request.

[0184] For the SMF, upon receiving the redirection request, it can resend the third message associated with the request policy originally sent to the first PCF to the third PCF. This effectively corrects the previously incorrectly selected PCF and reselects a consistent one.

[0185] In the above, for any given PCF, it can serve as the PCF selected by the terminal that first accesses the network during the PDU session establishment process of a group of DualSteer terminals. Upon receiving a request for policy association, it responds with a policy association response and stores the information related to the terminal's dual-direction association into the second network function (note that during this process, the PCF can also query the BSF; if it does not exist, it means that it was the terminal that accessed the network first, and then the storage operation is performed). Alternatively, it can serve as the PCF selected by the terminal that accesses the network later. In this case, upon receiving a request for policy association, the PCF queries the BSF (it can first query the UDM to obtain the fourth information) to determine the PCF selected by the first DualSteer associated terminal. Thus, if the PCF selected by the first terminal is inconsistent with itself, it sends a redirection request to the SMF to ensure consistency. In this case, the PCF does not need to respond with a policy association to the SMF. If the PCF selected by the first terminal is consistent with itself, the PCF can directly respond with a policy association to the SMF.

[0186] For the SMF in Scheme 2, during any PDU session establishment process, when selecting the PCF, the SMF does not need to consider the DualSteer association relationship and can still customize the selection of the PCF according to the strategies or rules in related technologies. This disclosure does not restrict this. However, after selecting the PCF, the policy association request sent by the SMF to the PCF carries information related to the dual-steer association relationship of the terminal (such as second information).

[0187] In one possible embodiment, before sending the second message to the second PCF, the SMF may further: query the UDM for the second information corresponding to the second terminal; wherein the UDM is used to maintain the second information related to each terminal during the terminal registration process. In other words, after receiving a request message from the AMF, the SMF may directly add the second information carried in the request message to the second message sent to the PCF; or, it may further query the UDM to carry accurate or complete second information in the second message and pass it to the PCF.

[0188] After that, for SMF, there are two possible scenarios:

[0189] In the first scenario, if the PCF selected by the SMF is correct, the PCF will send a policy-related response (SM Policy) to the SMF. After receiving this response message, the SMF can proceed with the subsequent PDU session establishment process according to the relevant technologies.

[0190] In the second scenario, the PCF selected by the SMF is problematic, for example, the PCF selected by the DualSteer associated terminal described in this disclosure is inconsistent. In this case, the SMF can receive a redirection request from the PCF. In this situation, the SMF also needs to perform redirection processing, specifically: the SMF disconnects its policy association with the original PCF and re-establishes a policy association with the new PCF indicated in the redirection request.

[0191] In one exemplary embodiment, the first PCF is taken as the original PCF, and the fourth PCF is taken as the PCF carried in the redirection request. For SMF, in addition to S402 and S404 mentioned above, the method also includes the following steps:

[0192] The SMF receives a redirection request from the first PCF, the redirection request carrying the identifier of the fourth PCF; wherein the fourth PCF is determined by the first PCF based on the second information in the second network function.

[0193] SMF redirects the second message to the fourth PCF.

[0194] More specifically, when the SMF redirects the second message to the fourth PCF, it can process it as follows: For the second message, the SMF disassociates itself from the first PCF and establishes a policy association with the fourth PCF. For example, the SMF can resend the second message to the fourth PCF to request policy association from the fourth PCF.

[0195] Thus, through the above process, SMF only needs to process the redirection request accordingly. Apart from that, for SMF, the implementation process for the multi-connection session establishment scheme is basically the same as that for the single-access session establishment scheme. It can reuse relevant existing technologies and only needs to transmit information related to the dual-redirection association relationship of the terminal in addition to the existing technologies.

[0196] To illustrate this solution more clearly, this disclosure also provides a possible embodiment. Please refer to... Figure 5 , Figure 5 This is a flowchart illustrating a communication method provided in an embodiment of this disclosure. Figure 5 As shown, the method includes:

[0197] S1, UE1 (or SUPI1, i.e., the first terminal) registers with the network through AMF1 (i.e., the first AMF).

[0198] In the specific implementation process, AMF1 can store SUPI1, SUPI2 and DS association ID (i.e. the second information of Scheme 1, or information related to the dual-turn association relationship of the terminal) into UDM.

[0199] S2, UE1 establishes a PDU session through SMF.

[0200] Specifically, the SMF selects PCF1 (i.e., the first PCF) for policy association. Then, PCF1 stores the association information (i.e., the PCF identifier and the second information, i.e., the association identifiers of PCF1, SUPI1, SUPI2 and DS) in the BSF (i.e., the second network function).

[0201] S3, UE2 registers with the network through AMF2 (i.e., the second AMF).

[0202] S4, UE2 establishes a PDU session through SMF, that is, AMF2 selects the same SMF, AMF2 initiates a PDU session establishment request to SMF, carrying SUPI2 and DS association ID.

[0203] S5, SMF queries UDM and determines that SUPI1 and SUPI2 have a DualSteer relationship.

[0204] S6, SMF selects PCF2 and sends a policy association request (i.e., the second message) to PCF2, which carries SUPI1, SUPI2 and DS association ID (i.e., the second information).

[0205] S7, PCF2 queries PCF1 associated with SUPI1 in BSF. When PCF1 and PCF2 are inconsistent, PCF redirection is performed.

[0206] The query request includes SUPI1, SUPI2, and the DS association ID.

[0207] If PCF2 is different from PCF1, then PCF2 will redirect the PDU session established by UE2 to PCF1 and establish a session policy association.

[0208] In practice: PCF2 sends a redirection request to SMF, carrying the identifier of PCF1 in the redirection request. Based on this redirection request, SMF terminates its policy association with PCF2 and establishes a policy association with PCF1.

[0209] In this way, UE1 and UE2, which have a DualSteer relationship, can finally access the same PCF1.

[0210] In summary, in Scheme 2 provided by this disclosure, during the existing single-connection session establishment process, the second information related to the DualSteer association is additionally stored in the second network function (e.g., BSF). The SMF can use the existing single-access scheme to select the PCF. The PCF queries the BSF to determine whether the current PCF is consistent with the PCF of the previously connected DualSteer associated terminal. If they are inconsistent, the PCF triggers a redirection to the SMF, and the SMF then re-processes the policy association. In this way, it can be ensured that all DualSteer associated terminals access the same PCF, solving the problem that the existing single-connection session establishment scheme cannot solve—multiple access sessions selecting the same PCF. It is simple and easy to implement, which is conducive to promoting and popularizing multi-access schemes on the existing network basis, leveraging the advantages of multi-access schemes, and improving the efficiency of operators' core resources.

[0211] In summary, this disclosure addresses the problem of multiple access sessions selecting the same PCF, a problem that existing single-connection session establishment schemes cannot solve. Two solutions are provided: In Scheme 1, the PCF stores the service's SUPI1, SUPI2, and DS association ID during NRF registration. The SMF then queries the NRF during subsequent processing to select the same PCF for terminals with DualSteer associations. In Scheme 2, UE1 stores SUPI1, SUPI2, and the association in the UDM during registration. After selecting a PCF, the PCF stores its PCF identifier, SUPI1, SUPI2, and association identifier in the BSF. When UE2 establishes a session, the SMF retrieves this association from the UDM and passes it to the PCF after selection. The PCF then checks the BSF to see if it matches the PCF of SUPI1. If not, it redirects to UE1's PCF. Thus, both schemes effectively solve the problem of multiple access sessions selecting the same PCF, enabling dual 3GPP access for users and improving service quality.

[0212] This disclosure also provides a communication device. Figure 6 A structural block diagram of a communication device provided in an embodiment of this disclosure, such as... Figure 6 As shown, the communication device 600 includes:

[0213] The transceiver unit 610 is used to receive a first message from the SMF, the first message carrying first information, and the first information being related to the dual-direction association relationship of the terminal.

[0214] The processing unit 620 is used to store the first information into the first network function.

[0215] In one exemplary embodiment, the first information includes at least one of the following:

[0216] The first identifier of the first terminal is SUPI1;

[0217] The second identifier of the second terminal is SUPI2;

[0218] Associated identifier;

[0219] The first PDU session ID of the first terminal;

[0220] The second PDU session ID of the second terminal;

[0221] Associated session ID.

[0222] In one exemplary embodiment, the association identifier is used to indicate that the first terminal and the second terminal have a bidirectional association relationship;

[0223] The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

[0224] In one exemplary embodiment, the first network function is a Network Repository Function (NRF).

[0225] In one exemplary embodiment, the processing unit 620 is specifically configured to: update the registration information of the first PCF in the first network function based on the first information; wherein the registration information includes the first information.

[0226] In one exemplary embodiment, the first network function is used to provide the first information to the SMF so that the SMF selects the same PCF for the dual-steering terminal.

[0227] This disclosure also provides another communication device. Figure 7 A structural block diagram of another communication device provided in this disclosure embodiment, such as... Figure 7 As shown, the communication device 700 includes:

[0228] The transceiver unit 710 is used to receive a second message from the session management function (SMF), the second message carrying second information, the second information being related to the terminal's dual-direction association relationship;

[0229] The processing unit 720 is used to store the second information into the second network function.

[0230] In one exemplary embodiment, the second information includes at least one of the following:

[0231] The first identifier of the first terminal is SUPI1;

[0232] The second identifier of the second terminal is SUPI2;

[0233] Associated identifier;

[0234] The first PDU session ID of the first terminal;

[0235] The second PDU session ID of the second terminal;

[0236] Associated session ID.

[0237] In one exemplary embodiment, the association identifier is used to indicate that the first terminal and the second terminal have a bidirectional association relationship;

[0238] The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

[0239] In one exemplary embodiment, the second network function is the Binding Support Function (BSF).

[0240] In one exemplary embodiment, the processing unit 720 is specifically configured to: associate the identifier of the first PCF with the second information and store it in the second network function.

[0241] In one exemplary embodiment, the second network function is used to provide association information for the second PCF so that the second PCF can redirect the policy association request when the PCFs of the two-way terminals are inconsistent; the association information is the association information between the identifier of the first PCF and the second information; wherein, the second PCF is the PCF selected by the SMF for the second PDU session of the second terminal.

[0242] In one exemplary embodiment, the transceiver unit 710 is further configured to receive a third message from the SMF, the third message being used to request policy association, the third message carrying third information; the third information is related to the terminal's dual-direction association relationship;

[0243] The processing unit 720 is further configured to query the third PCF corresponding to the third information in the second network function;

[0244] The processing unit 720 is further configured to redirect the third message to the third PCF when the third PCF is inconsistent with the first PCF.

[0245] In one exemplary embodiment, the third information includes at least one of the following:

[0246] The third identifier of the third terminal is SUPI3;

[0247] The fourth identifier of the fourth terminal is SUPI4;

[0248] Associated identifier;

[0249] The third terminal's third PDU session ID;

[0250] The fourth PDU session ID of the fourth terminal;

[0251] Associated session ID.

[0252] In one exemplary embodiment, the processing unit 720 is specifically used for:

[0253] Based on the third information, the fourth information of the fourth terminal is queried, the fourth information including at least one of the following: the fourth identifier SUPI4 of the fourth terminal; an association identifier;

[0254] Based on the fourth information, the third PCF is queried in the second network function.

[0255] In one exemplary embodiment, the processing unit 720 is specifically used for:

[0256] A redirection request is sent to the SMF, the redirection request carrying the identifier of the third PCF, so that the SMF can send the third message to the third PCF.

[0257] This disclosure also provides another communication device. Figure 8 A structural block diagram of another communication device provided in this disclosure embodiment, such as... Figure 8 As shown, the communication device 800 includes:

[0258] The receiving unit 810 is configured to receive a fourth message from the first access and mobility management function (AMF), the fourth message requesting the establishment of a PDU session for the first terminal, and the fourth message carrying first information;

[0259] The sending unit 820 is used to send a first message to the first PCF, the first message carrying the first information; wherein the first information is related to the dual-direction association relationship of the terminal.

[0260] In one exemplary embodiment, the first information includes at least one of the following:

[0261] The first identifier of the first terminal is SUPI1;

[0262] The second identifier of the second terminal is SUPI2;

[0263] Associated identifier;

[0264] The first PDU session ID of the first terminal;

[0265] The second PDU session ID of the second terminal;

[0266] Associated session ID.

[0267] In one exemplary embodiment, the association identifier is used to indicate that the first terminal and the second terminal have a bidirectional association relationship;

[0268] The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

[0269] In one exemplary embodiment, the method further includes a query unit;

[0270] The receiving unit 810 is further configured to receive a fifth message from the second AMF, the fifth message requesting the establishment of a PDU session for the second terminal; the fifth message carries fifth information, the fifth information being all or part of the first information;

[0271] The query unit is used to query the first PCF corresponding to the fifth information in the first network function;

[0272] The sending unit 820 is also configured to send a sixth message to the first PCF, the sixth message being used to request policy association.

[0273] In one exemplary embodiment, the first network function is a Network Repository Function (NRF).

[0274] This disclosure also provides another communication device. Figure 9 A structural block diagram of another communication device provided in this disclosure embodiment, such as... Figure 9 As shown, the communication device 900 includes:

[0275] The receiving unit 910 is configured to receive a seventh message from the first access and mobility management function (AMF), the seventh message requesting the establishment of a PDU session for the first terminal, and the seventh message carrying second information;

[0276] The sending unit 920 is used to send a second message to the first PCF, the second message carrying the second information; wherein the second information is related to the dual-turn association relationship of the terminal.

[0277] In one exemplary embodiment, the second information includes at least one of the following:

[0278] The first identifier of the first terminal is SUPI1;

[0279] The second identifier of the second terminal is SUPI2;

[0280] Associated identifier;

[0281] The first PDU session ID of the first terminal;

[0282] The second PDU session ID of the second terminal;

[0283] Associated session ID.

[0284] In one exemplary embodiment, the association identifier is used to indicate that the first terminal and the second terminal have a bidirectional association relationship;

[0285] The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

[0286] In one exemplary embodiment, the device further includes a processing unit;

[0287] The receiving unit 910 is further configured to receive a redirection request from the first PCF, the redirection request carrying the identifier of the fourth PCF; wherein the fourth PCF is determined by the first PCF based on the second information in the second network function;

[0288] The processing unit is also configured to redirect the second message to the fourth PCF.

[0289] In one exemplary embodiment, the processing unit is specifically configured to: for the second message, disconnect the policy association with the first PCF and establish a policy association with the fourth PCF.

[0290] In one exemplary embodiment, the second network function is the Binding Support Function (BSF).

[0291] In one exemplary embodiment, the processing unit is configured to query the second information corresponding to the first terminal in the Unified Data Management (UDM); wherein, the UDM is configured to maintain the second information related to each terminal during the terminal registration process;

[0292] The second information is sent to the second PCF.

[0293] This disclosure also provides another communication system. Figure 10 A structural block diagram of a communication system provided in this disclosure embodiment is shown below. Figure 10 As shown, the communication system 1000 includes:

[0294] PCF 1010 is used to implement the method executed by the PCF in any of the preceding embodiments;

[0295] SMF 1020 is used to implement the method executed by SMF in any of the preceding embodiments.

[0296] For any points not covered herein, please refer to the relevant explanations in the preceding method sections.

[0297] Figure 11 This is a hardware block diagram of an electronic device provided according to an embodiment of the present disclosure. The electronic device 1100 according to an embodiment of the present disclosure includes at least a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the communication method described in any of the above embodiments.

[0298] Figure 11 The illustrated electronic device 1100 specifically includes a central processing unit (CPU) 1101, a graphics processing unit (GPU) 1102, and a memory 1103. These units are interconnected via a bus 1104. The CPU 1101 and / or GPU 1102 can function as the aforementioned processor, and the memory 1103 can function as the aforementioned memory storing computer-readable instructions. Furthermore, the electronic device 1100 may also include a communication unit 1105, a storage unit 1106, an output unit 1107, an input unit 1108, and an external device 1109, all of which are also connected to the bus 1104.

[0299] Figure 12 This is a schematic diagram of a computer-readable storage medium provided in an embodiment of the present disclosure. The computer-readable storage medium according to an embodiment of the present disclosure stores a computer program / instruction thereon, for example... Figure 12 As shown, a computer-readable storage medium 1200 stores computer-readable instructions 1201 thereon; when executed by a processor, this computer program / instruction implements the communication method described in any of the preceding embodiments of this disclosure. The computer-readable storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, optical disk, magnetic disk, etc.

[0300] This disclosure further provides a computer program product, including a computer program that, when executed by a processor, implements the communication method described in any of the preceding embodiments of this disclosure.

[0301] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0302] The block diagrams of devices, apparatuses, devices, and systems disclosed herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0303] Additionally, as used herein, the “or” used in a list of items beginning with “at least one” indicates a separate list, such that a list of, for example, “at least one of A, B, or C” means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word “exemplary” does not imply that the described example is preferred or better than other examples.

[0304] It should also be noted that in the systems and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions to this disclosure.

[0305] Various changes, substitutions, and modifications can be made to the technology described herein without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, events, means, methods, and actions described above. Currently existing or later-developed processes, machines, manufactures, events, means, methods, or actions that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Therefore, the appended claims include such processes, machines, manufactures, events, means, methods, or actions within their scope.

[0306] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0307] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A communication method, characterized in that, The method, applied to the first policy control function (PCF), includes: Receive a first message from the Session Management Function (SMF), the first message carrying first information, the first information being related to the terminal's dual-direction association relationship; Store the first information into the first network function.

2. The method according to claim 1, characterized in that, The first information includes at least one of the following: The first identifier of the first terminal is SUPI1; The second identifier of the second terminal is SUPI2; Associated identifier; The first PDU session ID of the first terminal; The second PDU session ID of the second terminal; Associated session ID.

3. The method according to claim 2, characterized in that, The association identifier is used to indicate that the first terminal and the second terminal have a dual-direction association relationship; The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

4. The method according to claim 1, characterized in that, The first network function is the Network Repository Function (NRF).

5. The method according to any one of claims 1-4, characterized in that, The step of storing the first information into the first network function includes: Based on the first information, the registration information of the first PCF is updated in the first network function; wherein the registration information includes the first information.

6. The method according to any one of claims 1-5, characterized in that, The first network function is used to provide the first information to the SMF so that the SMF can select the same PCF for the dual-steering terminal.

7. A communication method, characterized in that, Applied to a first PCF, the method includes: Receive a second message from SMF, the second message carrying second information, the second information being related to the terminal's dual-turn association relationship; The second information is stored in the second network function.

8. The method according to claim 7, characterized in that, The second information includes at least one of the following: The first identifier of the first terminal is SUPI1; The second identifier of the second terminal is SUPI2; Associated identifier; The first PDU session ID of the first terminal; The second PDU session ID of the second terminal; Associated session ID.

9. The method according to claim 8, characterized in that, The association identifier is used to indicate that the first terminal and the second terminal have a dual-direction association relationship; The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

10. The method according to claim 7, characterized in that, The second network function is the Binding Support Function (BSF).

11. The method according to any one of claims 7-10, characterized in that, The step of storing the second information into the second network function includes: The identifier of the first PCF is associated with the second information and stored in the second network function.

12. The method according to any one of claims 7-11, characterized in that, The second network function is used to provide association information to the second PCF so that the second PCF can redirect the policy association request when the PCFs of the two-way terminals are inconsistent; The association information is the association information between the identifier of the first PCF and the second information; Wherein, the second PCF is the PCF selected by the SMF for the second PDU session of the second terminal.

13. The method according to any one of claims 7-11, characterized in that, The method further includes: Receive a third message from the SMF, the third message being used to request policy association, the third message carrying third information; the third information is related to the terminal's dual-direction association relationship; In the second network function, query the third PCF corresponding to the third information; When the third PCF is inconsistent with the first PCF, the third message is redirected to the third PCF.

14. The method according to claim 13, characterized in that, The third information includes at least one of the following: The third identifier of the third terminal is SUPI3; The fourth identifier of the fourth terminal is SUPI4; Associated identifier; The third terminal's third PDU session ID; The fourth PDU session ID of the fourth terminal; Associated session ID.

15. The method according to claim 13, characterized in that, The step of querying the third PCF corresponding to the third information in the second network function includes: Based on the third information, the fourth information of the fourth terminal is queried, the fourth information including at least one of the following: the fourth identifier SUPI4 of the fourth terminal; an association identifier; Based on the fourth information, the third PCF is queried in the second network function.

16. The method according to claim 13, characterized in that, The step of redirecting the third message to the third PCF includes: A redirection request is sent to the SMF, the redirection request carrying the identifier of the third PCF, so that the SMF can send the third message to the third PCF.

17. A communication method, characterized in that, Applied to SMF, the method includes: Receive a fourth message from the first AMF, the fourth message requesting the establishment of a PDU session for the first terminal, the fourth message carrying first information; A first message is sent to the first PCF, the first message carrying the first information; wherein the first information is related to the dual-turn association relationship of the terminal.

18. The method according to claim 17, characterized in that, The first information includes at least one of the following: The first identifier of the first terminal is SUPI1; The second identifier of the second terminal is SUPI2; Associated identifier; The first PDU session ID of the first terminal; The second PDU session ID of the second terminal; Associated session ID.

19. The method according to claim 18, characterized in that, The association identifier is used to indicate that the first terminal and the second terminal have a dual-direction association relationship; The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

20. The method according to any one of claims 17-19, characterized in that, The method further includes: A fifth message is received from the second AMF, the fifth message requesting the establishment of a PDU session for the second terminal; the fifth message carries fifth information, the fifth information being all or part of the first information; In the first network function, query the first PCF corresponding to the fifth information; A sixth message is sent to the first PCF, the sixth message being used to request policy association.

21. The method according to claim 20, characterized in that, The first network function is the Network Repository Function (NRF).

22. A communication method, characterized in that, Applied to SMF, the method includes: Receive a seventh message from the first AMF, the seventh message requesting the establishment of a PDU session for the first terminal, the seventh message carrying second information; A second message is sent to the first PCF, the second message carrying the second information; wherein the second information is related to the dual-turn association relationship of the terminal.

23. The method according to claim 22, characterized in that, The second information includes at least one of the following: The first identifier of the first terminal is SUPI1; The second identifier of the second terminal is SUPI2; Associated identifier; The first PDU session ID of the first terminal; The second PDU session ID of the second terminal; Associated session ID.

24. The method according to claim 23, characterized in that, The association identifier is used to indicate that the first terminal and the second terminal have a dual-direction association relationship; The associated session ID is used to indicate that the first PDU session of the first terminal and the second PDU session of the second terminal are a pair of dual-direction PDU sessions.

25. The method according to any one of claims 22-24, characterized in that, The method further includes: A redirection request is received from the first PCF, the redirection request carrying the identifier of the fourth PCF; wherein the fourth PCF is determined by the first PCF based on the second information in the second network function; The second message is redirected to the fourth PCF.

26. The method according to claim 25, characterized in that, The step of redirecting the second message to the fourth PCF includes: In response to the second message, the policy association with the first PCF is terminated, and a policy association is established with the fourth PCF.

27. The method according to claim 25, characterized in that, The second network function is the Binding Support Function (BSF).

28. The method according to any one of claims 22-27, characterized in that, The method further includes: Query the second information corresponding to the second terminal in the Unified Data Management (UDM); wherein, the UDM is used to maintain the second information related to each terminal during the terminal registration process; The second information is sent to the second PCF.

29. A communication device, characterized in that, include: The transceiver unit is used to receive a first message from the Session Management Function (SMF). The first message carries first information, which is related to the dual-direction association relationship of the terminal. The processing unit is used to store the first information into the first network function.

30. A communication device, characterized in that, include: The transceiver unit is used to receive a second message from the Session Management Function (SMF). The second message carries second information, which is related to the dual-direction association relationship of the terminal. The processing unit is used to store the second information into the second network function.

31. A communication device, characterized in that, include: The receiving unit is configured to receive a fourth message from the first access and mobility management function (AMF), the fourth message requesting the establishment of a PDU session for the first terminal, and the fourth message carrying first information; The sending unit is used to send a first message to the first PCF, the first message carrying the first information; wherein the first information is related to the dual-direction association relationship of the terminal.

32. A communication device, characterized in that, include: The receiving unit is configured to receive a seventh message from the first access and mobility management function (AMF), the seventh message requesting the establishment of a PDU session for the first terminal, and the seventh message carrying second information; The sending unit is used to send a second message to the first PCF, the second message carrying the second information; wherein the second information is related to the dual-turn association relationship of the terminal.

33. A communication system, characterized in that, include: PCF, used to implement the method according to any one of claims 1-16; SMF, used to implement the method according to any one of claims 17-28.

34. An electronic device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the method according to any one of claims 1-28.

35. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instructions are executed by the processor, they implement the method described in any one of claims 1-28.

36. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1-28.

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