Communication method, communication apparatus, chip, computer-readable storage medium and computer program product

Abstract

The present application provides a communication method, a communication apparatus, a chip, a computer-readable storage medium and a computer program product. The method comprises: receiving first information from a first network element, wherein the first information comprises first identification information, the first identification information is used for identifying a first home policy control function network element, the first home policy control function network element is a home policy control function network element associated with a first user equipment (UE), and the first UE is one UE in a dualsteer device; on the basis of the first information, determining the first home policy control function network element; and sending a first message, wherein the first message comprises the first identification information, the first message is used for requesting the establishment or modification of policy association for a second UE in the dualsteer device, and the second UE is associated with the first UE. Thus, associated policies can be determined for two UEs in a dualsteer device.

Description

Communication method, communication device, chip, computer-readable storage medium, and computer program product

[0001] This application claims priority to the Chinese patent application with application number 202410405023.4 filed with the State Intellectual Property Office of China on April 3, 2024, and priority to the Chinese patent application with the invention name “Communication method, communication device, chip, computer-readable storage medium and computer program product”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and in particular to a communication method, a communication device, a chip, a computer-readable storage medium, and a computer program product. Background Art

[0003] A DualSteer device is a device that supports service diversion and / or exchange of user data (for different services) across two 3rd generation partnership project (3GPP) access networks. The naming of the DualSteer device is not limited. When a DualSteer device performs asynchronous data transmission on two networks, it can be regarded as a single user equipment (UE); when it performs synchronous data transmission on two networks, it can be regarded as two separate UEs. A DualSteer device can use two universal subscriber identity modules (USIMs) to communicate using different 3GPP access methods. The two UE devices in the DualSteer device can use associated sessions to carry services, and the steering policy can achieve better continuity of services when switching between different radio access technologies (RATs). For example, a dual-directional device includes two UEs, UE1 and UE2, corresponding to subscription permanent identifiers (SUPI) 1 and SUPI2, respectively, and using RATs for terrestrial networks (TN) 1 and non-terrestrial networks (NTN), respectively. UE1 uses protocol data unit (PDU) session 1 to provide service 1. The session associated with PDU session 1 on UE2 is PDU session 2. PDU sessions 1 and 2 use the same Internet protocol (IP) address. When service 1 switches from PDU session 1 to PDU session 2, the IP address used by service 1 does not change, and there is no service interruption due to the IP address change.

[0004] In order to obtain the benefits of using DualSteer, the two USIMs may need to use associated access and mobility (AM) policies / UE policies. For example, UE1 and UE2 in a dual-Steer device need to use the same UE route selection policy (URSP) rules to determine the parameters of the session used by the service on the dual-Steer device, the indication of whether the session can be switched between UE1 / UE2, etc. For another example, when the RAT accessed by UE1 is TN1, UE2 gives priority to accessing NTN, which can provide better service continuity using satellite connection when the TN1 signal is weak. For another example, when UE1 accesses public land mobile network (PLMN) 1, UE2 gives priority to accessing base stations / networks of other PLMNs, which may ensure better service reliability when the PLMN1 network is congested. Therefore, it is necessary to study how to implement the determination of associated policies for the two UEs in the dual-Steer device. Summary of the Invention

[0005] Embodiments of the present application disclose a communication method, a communication device, a chip, a computer-readable storage medium, and a computer program product; these can be used to implement an association strategy for two UEs in a dual-directional device.

[0006] In a first aspect, an embodiment of the present application provides a communication method, which is applied to an access and mobility management function network element. The method can be implemented by the access and mobility management function network element or a component on the access and mobility management function network element side. The following description takes the implementation of the access and mobility management function network element as an example. The method includes: the access and mobility management function network element receives first information from a first network element, the first information includes first identification information, the first identification information is used to identify a first home policy control function network element, the first home policy control function network element is a home policy control function network element associated with a first user device, the first user device is a user device in a dual-directional device, and the first network element can be used to store and manage the association relationship between the first home policy control function network element and the first user device; based on the first information, determine the first home policy control function network element; send a first message, the first message includes first identification information, the first message is used to request to establish or modify a policy association of a second user device in the dual-directional device, and the second user device is associated with the first user device. The first network element can be a unified data management (UDM) network element, a binding service function (BSF) network element, etc. The first user equipment and the second user equipment are not independent devices, but two parts or devices in a dual-directional device.

[0007] In an embodiment of the present application, the access and mobility management function network element determines the first home policy control function network element based on the first information and sends a first message; so that the policy control function network element that establishes a policy association with the second user equipment (that is, the policy control function network element that receives the first message) can obtain the AM policy of the first user equipment from the first home policy control function network element, and then determine the AM policy of the second user equipment based on the AM policy of the first user equipment; it can realize the determination of the associated policy for the two UEs in the dual-directional device.

[0008] In one possible implementation, the first information also includes first indication information, which is used to indicate that the first identification information is used to select the same home policy control function network element for two user devices in the dual-directional device, and can instruct the access and mobility management function network element to select the first home policy control function network element for the second user device.

[0009] In a possible implementation, the first message further includes the identifier of the first user equipment and the identifier of the second user equipment, so that the policy control function network element that establishes a policy association with the second user equipment obtains the identifier of the first user equipment and the identifier of the second user equipment.

[0010] In one possible implementation, the first information also includes second identification information, and the second identification information is used to identify the first visited location policy control function network element, and the first visited location policy control function network element is a visited location policy control function network element associated with the first user equipment; the access and mobility management function network element determines the first home location policy control function network element based on the first information, including: the access and mobility management function network element determines the first home location policy control function network element and the first visited location policy control function network element based on the first information; sending the first message includes: the access and mobility management function network element sends a first message to the first visited location policy control function network element, and the first message includes the first identification information, so that the first visited location policy control function network element obtains the UE policy of the second user equipment from the first home location policy control function network element, and determines the AM policy of the second user equipment according to the AM policy of the first user equipment; it can realize the determination of associated policies for the two UEs in the dual-directional device.

[0011] In one possible implementation, the method also includes: the access and mobility management function network element receives a registration request sent by the second user equipment when registering in the visited network; in response to the registration request, selects a second visited policy control function network element for the second user equipment; sending a first message includes: sending a first message to the second visited policy control function network element, the first message including first identification information, so that the second visited policy control function network element obtains the UE policy of the second user equipment and the AM policy of the first user equipment from the first home policy control function network element, and then determines the AM policy of the second user equipment according to the AM policy of the first user equipment; it is possible to determine the associated policy for the two UEs in the dual-directional device.

[0012] In one possible implementation, the method further includes: the access and mobility management function network element sending a first request message to the first network element, the first request message being used to request subscription information of the second user equipment; and the access and mobility management function network element receiving the first information from the first network element includes: the access and mobility management function network element receiving a first response message from the first network element, the first response message including the subscription information of the second user equipment and the first information. In this implementation, the first response message includes the subscription information of the second user equipment and the first information, and the first information does not need to be carried in an additional message, thereby saving signaling overhead.

[0013] In a second aspect, an embodiment of the present application provides a communication method, which is applied to an access and mobility management function network element. The method can be implemented by the access and mobility management function network element or a component on the access and mobility management function network element side. The following description takes the implementation of the access and mobility management function network element as an example. The method includes: the access and mobility management function network element receives a first message from the access and mobility management function network element, the first message is used to request to establish or modify a policy association for a second user device, the second user device is one of the dual-directional devices, the first message includes first identification information, the first identification information is used to identify a first home policy control function network element, the first home policy control function network element is a home policy control function network element associated with the first user device, the first user device is another user device in the dual-directional device, and the first user device and the second user device are associated; obtaining a policy for the first user device from the first home policy control function network element; determining a policy for the second user device based on the policy of the first user device; and being able to determine an associated policy for two UEs in the dual-directional device.

[0014] In one possible implementation, the method is applied to a policy control function network element for determining the AM policy of a first user device; determining the policy of a second user device based on the policy of the first user device includes: determining the AM policy of the second user device based on the AM policy of the first user device; and determining an associated AM policy for the second user device and the first user device.

[0015] In one possible implementation, obtaining the policy of the first user device from the first home policy control function network element includes: obtaining the AM policy of the first user device and the user device policy of the second user device from the first home policy control function network element; determining the policy of the second user device based on the policy of the first user device includes: determining the AM policy of the second user device based on the AM policy of the first user device; and an associated policy can be determined for the second user device and the first user device.

[0016] In a possible implementation, the method further includes: sending the AM policy of the second user equipment to the first home policy control function network element; so that the first visited policy control function network element managed by the first user equipment can obtain the AM policy of the second user equipment from the first home policy control function network element.

[0017] In one possible implementation, the method also includes: receiving an AM policy subscription message from the first home policy control function network element; when the AM policy of the second user device changes, in response to the AM policy subscription message, sending a policy change message to the first home policy control function network element, the policy change message including the changed AM policy of the second user device, so that the first home policy control function network element notifies the visited policy control function network element associated with the first user device to synchronously update the policy of the second user device.

[0018] In one possible implementation, the method further includes: obtaining the AM policy of the first user device from a visited location policy control function network element associated with the first user device; determining the AM policy of the second user device based on the AM policy of the first user device; and determining an associated AM policy for the second user device and the first user device.

[0019] In one possible implementation, the first message also includes identification information of the visited location policy control function network element associated with the first user device. The access and mobility management function network element can determine the visited location policy control function network element associated with the first user device based on the identification information, and then obtain the AM policy of the first user device from the visited location policy control function network element.

[0020] On the third aspect, an embodiment of the present application provides a communication method, which is applied to an access and mobility management function network element. The method can be implemented by the access and mobility management function network element or a component on the access and mobility management function network element side. The following is an illustration using the implementation of the access and mobility management function network element as an example. The method includes: receiving first information from a first network element, the first information including first identification information, the first identification information being used to identify a first home policy control function network element, the first home policy control function network element being a home policy control function network element associated with a first user equipment (UE), the first UE being one of the dual-directional devices, and the first network element being used to store and manage an association relationship between the first home policy control function network element and the first UE; determining the first home policy control function network element based on the first information; and sending a second message to the first home policy control function network element, the second message being used to request establishment or modification of a policy association for a second UE, the second UE being another of the dual-directional devices and being associated with the first UE, the second message including second identification information and / or third identification information, the second identification information being used to identify the visited UE policy control function network element associated with the first UE, and the third identification information being used to identify the first UE; so that the first home policy control function network element obtains an AM policy for the first UE from the visited UE policy control function network element associated with the first UE, and further determines an AM policy for the second UE based on the AM policy of the first UE; thereby determining associated policies for two UEs in the dual-directional device.

[0021] In one possible implementation, the first information also includes first indication information, which is used to indicate that the first identification information is used to select the same home policy control function network element for two user devices in the dual-directional device, and can instruct the access and mobility management function network element to select the first home policy control function network element for the second user device.

[0022] In one possible implementation, sending the second message to the first home policy control function network element includes: when the second user equipment registers on the home network, sending the second message to the first home policy control function network element so that the first home policy control function network element establishes an association with the second user equipment. Because the first home policy control function network element is the home policy control function network element associated with the first user equipment, the first home policy control function network element does not need to obtain the UE policy of the first user equipment from other devices, thereby saving signaling overhead.

[0023] In one possible implementation, the method also includes: sending a first request message to the first network element, the first request message is used to request the subscription information of the second user device; receiving the first information from the first network element includes: receiving a first response message from the first network element, the first response message includes the subscription information of the second user device and the first information, and the first information does not require additional message carrying; signaling overhead can be saved.

[0024] In a fourth aspect, an embodiment of the present application provides a communication method, which is applied to a first home policy control function network element (i.e., a home policy control function network element associated with a first user device). The method can be implemented by the first home policy control function network element or a component on the side of the first home policy control function network element, and is described below using the implementation of the first home policy control function network element as an example. The method includes: a first home location policy control function network element receives a second message from an access and mobility management function network element, the second message is used to request to establish or modify a policy association of a second user device, the second user device is one of the dual-directional devices, the second message includes second identification information and / or third identification information, the second identification information is used to identify the visited location policy control function network element associated with the first user device, the third identification information is used to identify the first user device, the first user device is another user device in the dual-directional devices, and the first user device and the second user device are associated; based on the second identification information and / or the third identification information, the AM policy of the first user device is obtained from the visited location policy control function network element associated with the first user device; so as to determine the AM policy of the second user device based on the AM policy of the first user device; and it is possible to determine the associated AM policies for the two UEs in the dual-directional devices.

[0025] In one possible implementation, obtaining the AM policy of the first user device from the visited location policy control function network element associated with the first user device based on the second identification information and / or the third identification information includes: determining the visited location policy control function network element associated with the first user device based on the third identification information; and obtaining the AM policy of the first user device from the visited location policy control function network element associated with the first user device.

[0026] In a fifth aspect, an embodiment of the present application provides a communication method, which is applied to an access and mobility management function network element. The method can be implemented by the access and mobility management function network element or a component on the access and mobility management function network element side. The following is an illustration of the implementation of the access and mobility management function network element. The method includes: the access and mobility management function network element selects a first home policy control function network element for a first user device, and the first user device is one of the dual-directional devices; when a first trigger condition is met, second information is sent to the first network element, and the second information includes first identification information, and the first identification information is used to identify the first home policy control function network element. The first trigger condition includes at least one of the following: knowing that the first user device has a dual-directional subscription or is authorized for dual-directional, knowing that the registration request message of the first user device contains a dual-directional indication and / or dual-directional capability, and knowing that the first user device is the primary user device in the dual-directional device; the first network element can store the association relationship between the first user device and the first home policy control function network element.

[0027] In one possible implementation, the first trigger condition also includes: knowing that the first user device is registered in the visited network; the second information also includes identification information of the visited policy control function network element associated with the first user device; and the first network element can store the identification information of the visited policy control function network element associated with the first user device.

[0028] In a possible implementation, the second information further includes first indication information, where the first indication information is used to indicate that the first identification information is used to select the same home policy control function network element for two user equipments in the dual-directional device.

[0029] In a sixth aspect, an embodiment of the present application provides a communication method, which is applied to a first network element. The method can be implemented by the first network element or a component on the first network element side. The following description takes the implementation of the first network element as an example. The first network element can be used to store and manage the association between the first home policy control function network element and the first user equipment. The method includes: receiving second information from a first access and mobility management function network element, the second information including first identification information, the first identification information being used to identify a home policy control function network element associated with a first user device, the first user device being one of the user devices in a dual-directional device; when a second trigger condition is met, sending a third message to the second access and mobility management function network element, the third message including the first identification information, the second trigger condition including at least one of the following: learning that the second user device has a dual-directional subscription and is associated with the first user device, learning that the second user device is a secondary user device in the dual-directional device, learning that the network registered by the first user device is different from the network registered by the second user device, or the type of wireless access technology adopted by the first user device is the same as or different from the type of wireless access technology adopted by the second user device, and the second user device and the first user device are in the same dual-directional device, wherein the second user device is associated with the first user device, and the second access and mobility management function network element is the access and mobility management function network element of the second user device.

[0030] In an embodiment of the present application, when the second trigger condition is met, a first response message is sent to the second access and mobility management function network element so that the second access and mobility management function network element can obtain the first identification information and then determine the home policy control function network element associated with the first user equipment.

[0031] In one possible implementation, the second trigger condition also includes: the first user equipment and the second user equipment are registered in the same visited network; the third message also includes: the identification information of the visited policy control function network element associated with the first user equipment, which can enable the second access and mobility management function network element to select the visited policy control function network element associated with the first user equipment for the second user equipment, thereby determining the associated policy for the two UEs in the dual-directional device.

[0032] In a possible implementation, the second information also includes first indication information, where the first indication information is used to indicate that the first identification information is used to select the same home policy control function network element for two user equipments in the dual-directional device, and the first response message also includes the first indication information.

[0033] In the seventh aspect, an embodiment of the present application provides a communication method, which is applied to a home location policy control function network element associated with a first user device. The method can be implemented by the home location policy control function network element or a component on the home location policy control function network element side. The following description will be made by taking the implementation of the home location policy control function network element associated with the first user device as an example. The method includes: the home location policy control function network element associated with the first user device sends a fourth message to the first visited location policy control function network element, and the fourth message is used to subscribe to the AM policy of the first user device; receives the AM policy of the first user device sent by the first visited location policy control function network element; sends the AM policy of the first user device to the second visited location policy control function network element, the second visited location policy control function network element is associated with the second user device, the second user device is another user device in the dual-directional device, and the second user device is associated with the first user device; it can be implemented to determine the associated policy for the two UEs in the dual-directional device.

[0034] In an eighth aspect, an embodiment of the present application provides a communication method, which is applied to a second access and mobility management function network element. The method can be implemented by the second access and mobility management function network element or a component on the second access and mobility management function network element side. The following description is made by taking the implementation of the second access and mobility management function network element as an example. The method includes: when a third trigger condition is met, sending a second request message to the first access and mobility management function network element, the second request message is used to request the identification information of the first policy control function network element associated with the first user equipment, the first user equipment is a user equipment in a dual-directional device, and the third trigger condition includes at least one of the following: knowing that the second user equipment has a dual-directional subscription and the second user equipment is associated with the first user equipment, knowing that the second user equipment is performing a dual-directional registration, knowing that the second user equipment is a secondary user equipment in the dual-directional device, and the first user equipment and the second user equipment are associated; receiving a second response message, the second response message including the identification information of the first policy control function network element.

[0035] In an embodiment of the present application, when the third trigger condition is met, a second request message is sent to the first access and mobility management function network element, and the identification information of the first policy control function network element can be obtained, and then the first policy control function network element is selected for the second user equipment for policy association; it is possible to determine the associated policy for the two UEs in the dual-directional device.

[0036] In a possible implementation, the method further includes: sending a second message to the first policy control function network element, where the second message is used to request establishment or modification of a policy association of the second user equipment, so that the first policy control function network element establishes or modifies the policy association of the second user equipment.

[0037] In the ninth aspect, an embodiment of the present application provides a communication method, which is applied to a first access and mobility management function network element. The method can be implemented by the first access and mobility management function network element or a component on the side of the first access and mobility management function network element. The following description will be made by taking the implementation of the first access and mobility management function network element as an example. The method includes: the first access and mobility management function network element receives a second request message from the second access and mobility management function network element, the second request message is used to request the identification information of the first policy control function network element associated with the first user equipment, and the first user equipment is a user equipment in the dual-directional device; and sends a second response message to the second access and mobility management function network element, the second response message includes the identification information of the first policy control function network element, so that the second access and mobility management function network element obtains the identification information of the first policy control function network element.

[0038] In a possible implementation, the method further includes: sending a third message to the first policy control function network element, where the third message is used to request establishment of a policy association for the first user equipment, so that the first policy control function network element establishes or modifies the policy association for the first user equipment.

[0039] In the tenth aspect, an embodiment of the present application provides a communication method, which is applied to a second access and mobility management function network element. The method can be implemented by the second access and mobility management function network element or a component on the second access and mobility management function network element side. The following description is made by taking the implementation of the second access and mobility management function network element as an example. The method includes: the second access and mobility management function network element selects a second policy control function network element for a second user device; sends a first message to the second policy control function network element, the first message is used to request to establish or modify a policy association for the second user device, the first message includes identification information of the second user device and identification information of the first user device, the second user device is associated with the first user device, and the second user device and the first user device are in the same dual-directional device, so that the second policy control function network element determines the policy control function network element associated with the first user device based on the identification information of the first user device.

[0040] On the eleventh aspect, an embodiment of the present application provides a communication method, which is applied to a second policy control function network element. The method can be implemented by the second policy control function network element or a component on the second policy control function network element side. The following description will be given by taking the implementation of the second policy control function network element as an example. The method includes: the second policy control function network element receives a first message, the first message is used to request to establish or modify the policy association of the second user device, the first message includes the identification information of the second user device and the identification information of the first user device, the second user device is associated with the first user device, and the second user device and the first user device are in the same dual-directional device; based on the identification information of the first user device, the identification information of the first policy control function network element associated with the first user device is obtained from the binding service function network element; the policy of the first user device is obtained from the first policy control function network element; according to the policy of the first user device, the policy of the second user device is determined; and it is possible to determine the associated policy for the two UEs in the dual-directional device.

[0041] In a twelfth aspect, an embodiment of the present application provides a communication device having the function of implementing the behavior in the method embodiment of the first aspect above. The communication device can be a communication device, or a component of a communication device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software implementations, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive first information from a first network element, the first information includes first identification information, the first identification information is used to identify a first home policy control function network element, the first home policy control function network element is a home policy control function network element associated with a first user device, the first user device is a user device in a dual-directional device, and the first network element can be used to store and manage the association relationship between the first home policy control function network element and the first user device; the processing module is used to determine the first home policy control function network element based on the first information; the transceiver module is also used to send a first message, the first message includes first identification information, the first message is used to request to establish or modify a policy association of a second user device in the dual-directional device, and the second user device is associated with the first user device.

[0042] In one possible implementation, the first information also includes second identification information, and the second identification information is used to identify the first visited location policy control function network element, and the first visited location policy control function network element is the visited location policy control function network element associated with the first user equipment; the processing module is specifically used to determine the first home location policy control function network element and the first visited location policy control function network element based on the first information; the transceiver module is specifically used to send a first message to the first visited location policy control function network element, and the first message includes the first identification information.

[0043] In one possible implementation, the transceiver module is also used to receive a registration request sent by the second user equipment when registering in the visited network; the processing module is also used to select a second visited policy control function network element for the second user equipment in response to the registration request; the transceiver module is specifically used to send a first message to the second visited policy control function network element, and the first message includes first identification information.

[0044] In one possible implementation, the transceiver module is also used to send a first request message to the first network element, where the first request message is used to request the contract information of the second user device; the transceiver module is specifically used to receive a first response message from the first network element, where the first response message includes the contract information of the second user device and the first information.

[0045] Possible implementations of the communication method of the twelfth aspect can refer to the various possible implementations of the first aspect.

[0046] For the technical effects brought about by various possible implementation methods of the twelfth aspect, reference may be made to the introduction to the technical effects of the first aspect or various possible implementation methods of the first aspect.

[0047] In a thirteenth aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the method embodiment of the second aspect above. The communication device can be a communication device, or it can be a component of a communication device (such as a processor, a chip, or a chip system, etc.), or it can be a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or they can be implemented by hardware executing corresponding software, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a first message from an access and mobility management function network element, the first message is used to request to establish or modify a policy association of a second user device, the second user device is one of the dual-directional devices, the first message includes first identification information, the first identification information is used to identify a first home policy control function network element, the first home policy control function network element is a home policy control function network element associated with the first user device, the first user device is another user device in the dual-directional device, and the first user device and the second user device are associated; the processing module is used to obtain a policy of the first user device from the first home policy control function network element; determine a policy of the second user device based on the policy of the first user device; and can determine the associated policy for the two UEs in the dual-directional device.

[0048] In a possible implementation, the communication device is a policy control function network element for determining an AM policy of a first user equipment; the processing module is specifically configured to determine an AM policy of a second user equipment based on the AM policy of the first user equipment.

[0049] In a possible implementation, the processing module is specifically configured to obtain the AM policy of the first user equipment and the user equipment policy of the second user equipment from the first home policy control function network element; and determine the AM policy of the second user equipment according to the AM policy of the first user equipment.

[0050] In a possible implementation, the transceiver module is further configured to send the AM policy of the second user equipment to the first home policy control function network element.

[0051] In one possible implementation, the transceiver module is also used to receive an AM policy subscription message from the first home policy control function network element; when the AM policy of the second user device changes, in response to the AM policy subscription message, a policy change message is sent to the first home policy control function network element, and the policy change message includes the changed AM policy of the second user device.

[0052] In a possible implementation, the processing module is further configured to obtain the AM policy of the first user equipment from a visited location policy control function network element associated with the first user equipment; and determine the AM policy of the second user equipment according to the AM policy of the first user equipment.

[0053] For possible implementations of the communication method of the thirteenth aspect, reference may be made to various possible implementations of the second aspect.

[0054] For the technical effects brought about by various possible implementation methods of the thirteenth aspect, reference may be made to the introduction to the technical effects of the second aspect or various possible implementation methods of the second aspect.

[0055] In a fourteenth aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the method embodiment of the third aspect above. The communication device can be a communication device, or it can be a component of a communication device (such as a processor, a chip, or a chip system, etc.), or it can be a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or they can be implemented by hardware executing corresponding software, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive first information from a first network element, the first information includes first identification information, the first identification information is used to identify a first home policy control function network element, the first home policy control function network element is a home policy control function network element associated with a first user device, the first user device is one of the dual-directional devices, and the first network element can be used to store and manage the association relationship between the first home policy control function network element and the first user device; the processing module is used to determine the first home policy control function network element based on the first information; the transceiver module is also used to send a second message to the first home policy control function network element, the second message is used to request to establish or modify a policy association of a second user device, the second user device is another user device in the dual-directional device, the second user device is associated with the first user device, the second message includes second identification information and / or third identification information, the second identification information is used to identify the visited policy control function network element associated with the first user device, and the third identification information is used to identify the first user device.

[0056] In a possible implementation, the transceiver module is specifically configured to send a second message to the first home policy control function network element when the second user equipment registers in the home network.

[0057] In one possible implementation, the transceiver module is also used to send a first request message to the first network element, where the first request message is used to request the contract information of the second user device; the transceiver module is specifically used to receive a first response message from the first network element, where the first response message includes the contract information of the second user device and the first information.

[0058] Possible implementations of the communication method of the fourteenth aspect can refer to the various possible implementations of the third aspect.

[0059] For the technical effects brought about by various possible implementation methods of the fourteenth aspect, reference may be made to the introduction to the technical effects of the third aspect or various possible implementation methods of the third aspect.

[0060] In a fifteenth aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the method embodiment of the fourth aspect above. The communication device can be a communication device, or it can be a component of a communication device (such as a processor, a chip, or a chip system, etc.), or it can be a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or they can be implemented by hardware executing corresponding software, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a second message from an access and mobility management function network element, the second message is used to request to establish or modify a policy association of a second user device, the second user device is one of the dual-directional devices, the second message includes second identification information and / or third identification information, the second identification information is used to identify the visited location policy control function network element associated with the first user device, the third identification information is used to identify the first user device, the first user device is another user device in the dual-directional device, and the first user device and the second user device are associated; the processing module is used to obtain the AM policy of the first user device from the visited location policy control function network element associated with the first user device based on the second identification information and / or the third identification information; so as to determine the AM policy of the second user device based on the AM policy of the first user device.

[0061] In a possible implementation, the processing module is specifically configured to determine a visited location policy control function network element associated with the first user equipment based on the third identification information; and obtain the AM policy of the first user equipment from the visited location policy control function network element associated with the first user equipment.

[0062] Possible implementations of the communication method of the fifteenth aspect can refer to the various possible implementations of the fourth aspect.

[0063] For the technical effects brought about by various possible implementation methods of the fifteenth aspect, reference may be made to the introduction to the technical effects of the fourth aspect or various possible implementation methods of the fourth aspect.

[0064] In a sixteenth aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the embodiment of the method of the fifth aspect above. The communication device can be a communication device, or a component of a communication device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to select a first home policy control function network element for a first user equipment, and the first user equipment is a user equipment in a dual-directional device; the transceiver module is used to send second information to the first network element when a first trigger condition is met, the second information includes first identification information, and the first identification information is used to identify the first home policy control function network element. The first trigger condition includes at least one of the following: knowing that the first user equipment has a dual-directional subscription or is authorized for dual-directional, knowing that the registration request message of the first user equipment contains a dual-directional indication and / or dual-directional capability, and knowing that the first user equipment is the primary user equipment in the dual-directional device.

[0065] For possible implementations of the communication method of the sixteenth aspect, reference can be made to various possible implementations of the fifth aspect.

[0066] For the technical effects brought about by various possible implementation methods of the sixteenth aspect, reference may be made to the introduction to the technical effects of the fifth aspect or various possible implementation methods of the fifth aspect.

[0067] In the seventeenth aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the method embodiment of the sixth aspect above. The communication device can be a communication device, or it can be a component of a communication device (such as a processor, a chip, or a chip system, etc.), or it can be a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or they can be implemented by hardware executing corresponding software, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is configured to receive second information from a first access and mobility management function network element, the second information including first identification information, the first identification information being used to identify a home policy control function network element associated with a first user equipment, and the first user equipment is a user equipment in a dual-directional device; the processing module is configured to determine whether a second trigger condition is satisfied; the transceiver module is further configured to send a third message to the second access and mobility management function network element when the second trigger condition is satisfied, the third message including the first identification information, and the second trigger condition including at least one of the following: learning that the second user equipment has a dual-directional subscription and is associated with the first user equipment, learning that the second user equipment is a secondary user equipment in the dual-directional device, learning that the network registered by the first user equipment is different from the network registered by the second user equipment, or that the type of radio access technology used by the first user equipment is the same as or different from the type of radio access technology used by the second user equipment, and the second user equipment and the first user equipment are in the same dual-directional device, wherein the second user equipment is associated with the first user equipment, and the second access and mobility management function network element is the access and mobility management function network element of the second user equipment.

[0068] For possible implementations of the communication method of the seventeenth aspect, reference may be made to various possible implementations of the sixth aspect.

[0069] For the technical effects brought about by various possible implementation methods of the seventeenth aspect, reference may be made to the introduction to the technical effects of the sixth aspect or various possible implementation methods of the sixth aspect.

[0070] In an eighteenth aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the embodiment of the method of the seventh aspect above. The communication device can be a communication device, or a component of a communication device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to generate a fourth message; the transceiver module is used to send the fourth message to a first visited location policy control function network element, the fourth message is used to subscribe to the AM policy of the first user equipment; receive the AM policy of the first user equipment sent by the first visited location policy control function network element; send the AM policy of the first user equipment to a second visited location policy control function network element, the second visited location policy control function network element is associated with the second user equipment, the second user equipment is another user equipment in the dual-directional device, and the second user equipment is associated with the first user equipment.

[0071] For the technical effects brought about by various possible implementation methods of the eighteenth aspect, reference may be made to the introduction to the technical effects of the seventh aspect or various possible implementation methods of the seventh aspect.

[0072] In the nineteenth aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the method embodiment of the eighth aspect above. The communication device can be a communication device, or it can be a component of a communication device (such as a processor, a chip, or a chip system, etc.), or it can be a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or they can be implemented by hardware executing corresponding software, and the hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to determine whether a third trigger condition is met; the transceiver module is used to send a second request message to the first access and mobility management function network element when the third trigger condition is met, the second request message is used to request the identification information of the first policy control function network element associated with the first user device, the first user device is a user device in the dual-directional device, and the third trigger condition includes at least one of the following: knowing that the second user device has a dual-directional subscription and the second user device is associated with the first user device, knowing that the second user device is performing a dual-directional registration, knowing that the second user device is a secondary user device in the dual-directional device, and the first user device and the second user device are associated; receiving a second response message, the second response message includes the identification information of the first policy control function network element.

[0073] In a possible implementation, the transceiver module is further configured to send a second message to the first policy control function network element, where the second message is used to request to establish or modify a policy association of the second user equipment.

[0074] Possible implementations of the communication method of the nineteenth aspect can refer to the various possible implementations of the eighth aspect.

[0075] Regarding the technical effects brought about by various possible implementation methods of the nineteenth aspect, reference may be made to the introduction to the technical effects of the eighth aspect or various possible implementation methods of the eighth aspect.

[0076] In a twentieth aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the embodiment of the method of the ninth aspect above. The communication device can be a communication device, or a component of a communication device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a second request message from a second access and mobility management function network element, the second request message is used to request the identification information of a first policy control function network element associated with a first user equipment, and the first user equipment is a user equipment in a dual-directional device; the processing module is used to generate a second response message; the transceiver module is also used to send a second response message to the second access and mobility management function network element, and the second response message includes the identification information of the first policy control function network element.

[0077] In a possible implementation, the transceiver module is further configured to send a third message to the first policy control function network element, where the third message is used to request establishment of a policy association for the first user equipment.

[0078] For possible implementations of the communication method of the twentieth aspect, reference may be made to various possible implementations of the ninth aspect.

[0079] For the technical effects brought about by various possible implementation methods of the twentieth aspect, reference may be made to the introduction to the technical effects of the ninth aspect or various possible implementation methods of the ninth aspect.

[0080] In a twenty-first aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the embodiment of the method in the tenth aspect above. The communication device can be a communication device, or a component of a communication device (such as a processor, chip, or chip system), or a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is configured to select a second policy control function network element for a second user equipment; the transceiver module is configured to send a first message to the second policy control function network element, the first message is used to request to establish or modify a policy association for the second user equipment, the first message includes identification information of the second user equipment and identification information of the first user equipment, the second user equipment is associated with the first user equipment, and the second user equipment and the first user equipment are in the same dual-directional device, so that the second policy control function network element determines the policy control function network element associated with the first user equipment based on the identification information of the first user equipment.

[0081] In a twenty-second aspect, an embodiment of the present application provides another communication device, which has the function of implementing the behavior in the method embodiment of the eleventh aspect above. The communication device can be a communication device, or a component of a communication device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the communication device. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a first message, the first message is used to request to establish or modify a policy association with a second user device, the first message includes identification information of the second user device and identification information of the first user device, the second user device is associated with the first user device, and the second user device and the first user device are in the same dual-directional device; the processing module is used to obtain, from a binding service function network element, identification information of a first policy control function network element associated with the first user device based on the identification information of the first user device; obtain a policy of the first user device from the first policy control function network element; and determine a policy of the second user device based on the policy of the first user device.

[0082] For the technical effects brought about by various possible implementation methods of the twenty-second aspect, please refer to the introduction to the technical effects of the eleventh aspect or various possible implementation methods of the eleventh aspect.

[0083] In the twenty-third aspect, an embodiment of the present application provides another communication device, which includes a processor, which is coupled to a memory, and the memory is used to store programs or instructions. When the program or instructions are executed by the processor, the communication device executes the method shown in any one of the above-mentioned first aspect to the above-mentioned eleventh aspect.

[0084] In the embodiment of the present application, during the execution of the above method, the process of sending information (or signals) in the above method can be understood as the process of outputting information based on the instructions of the processor. When outputting information, the processor outputs the information to the transceiver so that it can be transmitted by the transceiver. After being output by the processor, the information may also need to undergo other processing before reaching the transceiver. Similarly, when the processor receives input information, the transceiver receives the information and inputs it into the processor. Furthermore, after the transceiver receives the information, the information may need to undergo other processing before being input into the processor.

[0085] For operations such as sending and / or receiving involved in the processor, unless otherwise specified, or unless they conflict with their actual functions or internal logic in the relevant descriptions, they can be generally understood as instructions output based on the processor.

[0086] During implementation, the processor may be a processor specifically configured to execute these methods, or may be a processor that executes computer instructions in a memory to execute these methods, such as a general-purpose processor. For example, the processor may also be configured to execute a program stored in a memory. When the program is executed, the communication device performs the method described in the first aspect or any possible implementation of the first aspect.

[0087] In a possible implementation, the memory is located outside the communication device. In a possible implementation, the memory is located inside the communication device.

[0088] In a possible implementation, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together.

[0089] In a possible implementation, the communication device further includes a transceiver, and the transceiver is used to receive signals or send signals.

[0090] In aspect 24, the present application provides another communication device, which includes a processing circuit and an interface circuit, wherein the interface circuit is used to acquire data or output data; the processing circuit is used to execute the method shown in any one of aspects 1 to 11 above.

[0091] In aspect 25, the present application provides a computer-readable storage medium, which stores a computer program, and the computer program includes program instructions, which, when executed, enable the computer to execute the method shown in any one of aspects 1 to 11 above.

[0092] In aspect 26, the present application provides a computer program product, which includes a computer program, and the computer program includes program instructions, which, when executed, enable the computer to execute the method shown in any one of aspects 1 to 11 above.

[0093] In aspect 27, the present application provides a chip comprising a processor and a communication interface, wherein the communication interface is used for sending and receiving signals of the chip; the processor is used to execute computer program instructions so that a communication device comprising the chip executes a method as shown in any one of aspects 1 to 11 above. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 is a schematic diagram of a 5G network architecture based on a service-oriented architecture;

[0095] FIG2 is a flow chart of a communication method provided in an embodiment of the present application;

[0096] FIG3 is a flow chart of another communication method provided in an embodiment of the present application;

[0097] FIG4 is a flow chart of another communication method provided in an embodiment of the present application;

[0098] FIG5 is a flow chart of another communication method provided in an embodiment of the present application;

[0099] FIG6 is a flow chart of another communication method provided in an embodiment of the present application;

[0100] FIG7 is a flow chart of another communication method provided in an embodiment of the present application;

[0101] FIG8 is a flow chart of another communication method provided in an embodiment of the present application;

[0102] FIG9 is a flow chart of another communication method provided in an embodiment of the present application;

[0103] FIG10 is a flow chart of another communication method provided in an embodiment of the present application;

[0104] FIG11 is a schematic structural diagram of a communication device 1100 provided in an embodiment of the present application;

[0105] FIG12 is a schematic structural diagram of another device 120 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0106] The terms "first" and "second" in the specification, claims and drawings of the present application are only used to distinguish different objects, rather than to describe a specific order. It will be understood that the various digital numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of each of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and inherent logic. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0107] The "embodiment" mentioned in this document means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It can be understood explicitly and implicitly by those skilled in the art that the embodiments described herein can be combined with other embodiments. In this application, the naming of messages is only used to distinguish different messages and should not be understood as a limitation. In other words, the name of any message in this application can be replaced with other names, and this application is not limited.

[0108] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification of the present application and the appended claims, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear contrary indication in the context. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more listed items. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The term "multiple" used in the present application refers to two or more. In the textual description of the present application, the character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0109] It is understood that in each embodiment of the present application, "A corresponds to B" means that there is a corresponding relationship between A and B, and B can be determined according to A. However, it should also be understood that determining (or generating) B according to (or based on) A does not mean that B is determined (or generated) only according to (or based on) A, and B can also be determined (or generated) according to (or based on) A and / or other information.

[0110] It should be understood that, in this application, indication includes direct indication (also known as explicit indication) and implicit indication. Direct indication of information A refers to including information A; implicit indication of information A refers to indicating information A through the correspondence between information A and information B and the direct indication of information B. The correspondence between information A and information B can be predefined, pre-stored, pre-burned, or pre-configured.

[0111] It should be understood that, in this application, information C is used to determine information D, which includes both information D being determined solely based on information C and information D being determined based on information C and other information. Furthermore, information C can also be used to determine information D indirectly, for example, where information D is determined based on information E, and information E is determined based on information C.

[0112] In addition, in each embodiment of the present application, "network element A sends information A to network element B" can be understood as the destination end of the information A or the intermediate network element in the transmission path between the destination end and the network element B, which may include directly or indirectly sending information to network element B. "Network element B receives information A from network element A" can be understood as the source end of the information A or the intermediate network element in the transmission path between the source end and the network element A, which may include directly or indirectly receiving information from network element A. The information may be processed as necessary between the source end and the destination end of the information transmission, such as format changes, but the destination end can understand the valid information from the source end. Similar expressions in this application can be understood similarly and will not be elaborated here.

[0113] To facilitate understanding of the embodiments of the present application, the following is a brief description of the terms and technical features involved in the embodiments of the present application.

[0114] AM strategy: including RAT / Frequency Selection Priority (RFSP) index, service area restriction, etc.

[0115] UE policy: includes UE route selection policy (URSP), access network discovery and selection policy, etc. When a UE in a dual-directional device accesses through its home network, the UE's policy (including AM policy association and UE policy association) is determined (or generated) by the H-PCF of the UE's home network. When a UE in a dual-directional device accesses through a visited network (i.e., roaming), the UE's AM policy is determined (or generated) by the V-PCF of the visited network.

[0116] As described in the background technology section, there is currently a need to study how to implement an association policy for two UEs in a dual-directional device (or dual-directional apparatus) (i.e., two UEs in the dual-directional device). The technical solution provided in this application can implement an association policy for two UEs in the dual-directional device. The technical solution provided in this application is applicable to scenarios where one or both UEs in the dual-directional device are roaming, and is also applicable to scenarios where both UEs in the dual-directional device are non-roaming. The following first introduces the communication system to which the technical solution provided in this application is applicable.

[0117] The technical solution of the present application is mainly applicable to a mobile communication system supporting dual-directionality, which includes devices using dual subscriber identity modules (SIMs) and / or dual-directionality devices, that is, devices using dual-directionality.

[0118] The technical solutions provided in this application can be applied to various communication systems, such as: fifth generation (5G) or new radio (NR) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, wireless local area networks (WLAN) systems, satellite communication systems, future communication systems, such as sixth generation (6G) mobile communication systems, or a fusion system of multiple systems. The technical solutions provided in this application can also be applied to device to device (D2D) communication, vehicle-to-everything (V2X) communication, machine to machine (M2M) communication, machine type communication (MTC), and Internet of Things (IoT) communication systems or other communication systems.

[0119] In this application, the technical solution of this application is described by taking the cellular system related to the 3rd Generation Partnership Project (3GPP) as an example, but this should not constitute any limitation to this application. Based on the same concept, the technical method of this application can also be applied to other communication networks such as ZigBee, long range radio (Lora), Bluetooth (BT), and wireless fidelity (Wi-Fi). The technical solution provided in the embodiment of this application is also applicable to other communication systems that support dual-directionality. The above-mentioned communication system to which the technical solution provided in the embodiment of this application is applicable is only an example, and the communication system to which the technical solution provided in this application is applicable is not limited thereto. They are uniformly described here and will not be repeated below. The following introduces the application of the technical solution of this application in the 5G network architecture.

[0120] Figure 1 is a schematic diagram of a 5G network architecture based on a service-oriented architecture. The 5G network architecture shown in Figure 1 may include dual-directional devices, a (radio) access network (R)AN), and a core network. The 5G network architecture shown in Figure 1 may also include terminal devices (which may be referred to as UEs). The dual-directional devices and the terminal devices access the data network (DN) through the access network and the core network. A dual-directional (DualSteer) device is associated with two UEs (or more than two UEs). In other words, a dual-directional device includes two UEs (or more than two UEs). When a dual-directional device performs asynchronous data transmission on two networks, it can be regarded as a single UE; when it performs synchronous data transmission on two networks, it can be regarded as two separate UEs. The dual-directional device can use two USIMs to communicate using different 3GPP access methods. The two UE devices in the dual-directional device can use associated session bearer services, and the steering policy can achieve better continuity of services when switching between different RATs.

[0121] In one possible scenario, a terminal device stores a key (e.g., a long-term key) and related functions. The terminal device uses the stored key and related functions to verify the authenticity of the network during bidirectional authentication with core network elements (e.g., access and mobility management function (AMF) element and authentication server function (AUSF) element).

[0122] The terminal device may be a device that provides wireless communication functions, such as a handheld device or a vehicle-mounted device with a wireless connection function. At present, some examples of terminal devices are: mobile phones, satellite mobile terminals, cellular phones, smart phones, tablet computers, laptop computers, PDAs, mobile internet devices (MIDs), wearable devices (such as smart watches, smart bracelets, pedometers, smart glasses, etc.), vehicle-mounted devices (such as cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed railways, etc.), satellite terminals, virtual reality (VR) devices, augmented reality (AR) devices, smart point of sale (POS) machines, customer-premises equipment (CPE), wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, and wireless terminals in smart homes. The present invention also includes wireless terminals (e.g., refrigerators, televisions, air conditioners, electric meters, etc.) in homes, intelligent robots, robotic arms, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, flying devices (e.g., intelligent robots, hot air balloons, drones, airplanes), terminal devices in 5G networks, or terminal devices in future-evolved public land mobile networks (PLMNs), etc., which are not limited in the present application. As an example and not a limitation, in the present application, the terminal device may also be a mobile terminal (MT) in an IAB node. When the IAB node faces its parent node, it can be regarded as a terminal device, in which case the IAB node plays the role of an MT.The following description uses UE as an example of a terminal device, and UE appearing anywhere in the following text may be replaced by a terminal device or other examples of a terminal device. In this application, a dual-directional device may be a terminal device having two USIMs inserted therein.

[0123] In the embodiments of the present application, the device for realizing the function of the dual-directional device can be a dual-directional device, or a device capable of supporting the dual-directional device to realize the function, such as a chip system, which can be installed in the dual-directional device or used in conjunction with the dual-directional device. In the embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. In the embodiments of the present application, only the dual-directional device is used as an example for description, and the embodiments of the present application are not limited to the embodiments of the present application.

[0124] In the embodiments of the present application, the device for realizing the function of the terminal device can be a terminal device, or a device capable of supporting the terminal device to realize the function, such as a chip system, which can be installed in the terminal device or used in combination with the terminal device. In the embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. In the embodiments of the present application, only the terminal device is used as an example for description, and the embodiments of the present application are not limited to the solutions of the embodiments of the present application.

[0125] The access network (AN) can be an access network that uses different access technologies. Currently, there are two types of wireless access technologies: 3rd Generation Partnership Project (3GPP) access technology (such as the wireless access technology used in 3G, 4G or 5G systems) and non-3GPP (non-3GPP) access technology. 3GPP access technology refers to access technology that complies with 3GPP standards and specifications, and an access network that uses 3GPP access technology is called a radio access network (RAN). Non-3GPP access technology refers to access technology that does not comply with 3GPP standards and specifications, for example, air interface technology represented by wireless fidelity (WiFi).

[0126] The access network is used to implement access-related functions, and can provide network access functions for authorized users in a specific area, and can determine transmission links of different qualities to transmit user data based on the user level, business requirements, etc. The access network forwards control signals and user data between the UE and the core network. The access network may include access network equipment, which may be equipment that provides access for the UE, and may include radio access network (RAN) equipment and wired access network (FAN) equipment. The access network equipment in the embodiment of the present application may refer to a RAN node (or device) that connects the terminal device to the wireless network. The RAN equipment is mainly responsible for wireless resource management, quality of service (QoS) management, data compression and encryption and other functions on the air interface side. The RAN equipment may include various forms of base stations, such as macro base stations, micro base stations (also called small stations), relay stations, access points, balloon stations, etc. In systems using different radio access technologies, the names of devices with base station functions may be different. For example, in 5G systems, they are called RAN or next-generation Node basestation (gNB), and in long-term evolution (LTE) systems, they are called evolved NodeB (eNB or eNodeB).

[0127] The core network is responsible for maintaining mobile network subscription data and providing UEs with functions such as session management, mobility management, policy management, and security authentication. The core network includes, but is not limited to, the following network elements: application function (AF), unified data management (UDM), unified data repository (UDR), policy control function (PCF), session management function (SMF), access and mobility management function (AMF), network repository function (NRF), authentication server function (AUSF), network exposure function (NEF), and user plane function (UPF). The following describes some of the network elements in the core network.

[0128] AMF network element is mainly responsible for mobility management. For example, AMF is responsible for user location update, user registration network, user switching, etc.

[0129] The SMF network element is primarily responsible for session management in mobile networks, such as session establishment, modification, and release. Specific functions include allocating Internet Protocol (IP) addresses to users and selecting UPF network elements that provide packet forwarding functions.

[0130] The UPF network element is mainly responsible for forwarding and receiving user data. It can receive user data from the data network and transmit it to the UE through the access network equipment; it can also receive user data from the UE through the access network equipment and forward it to the data network.

[0131] AUSF network element, the functional entity of the network (i.e. core network) to authenticate the UE, is used by the network to verify whether the UE is authentic.

[0132] The PCF network element mainly supports providing a unified policy framework to control network behavior, provides policy rules for control plane functions, and is responsible for obtaining user subscription information related to policy decisions. The PCF network element can provide policies to the AMF network element and the SMF network element, such as QoS policy, slice selection policy, UE policy, etc. The visited policy control function (V-PCF) network element refers to the PCF network element in the visited public land mobile network of the UE. The home policy control function (H-PCF) network element refers to the PCF network element in the home public land mobile network of the UE.

[0133] The AF network element (or application functional entity) interacts with the 3GPP core network to provide application layer services. The AF network element can convey application-side requirements to the network, such as QoS requirements or user status event subscriptions. The AF can be a third-party functional entity or an application service deployed by the operator.

[0134] UDM network elements include functions such as executing and managing contract data, user access authentication, and authorization.

[0135] The UDR network element includes the access functions for executing contract data, policy data, application data and other types of data.

[0136] NEF network element is mainly used to support the opening of capabilities and events.

[0137] NRF network elements can be used to provide network element discovery capabilities, providing network element information corresponding to the network element type based on requests from other network elements. NRF also provides network element management services such as network element registration, update, and deregistration, as well as network element status subscription and push.

[0138] DN, on which various services can be deployed to provide data and / or voice services to UE. Among them, AF network element, UDM network element, UDR network element, PCF network element, SMF network element, AMF network element, NRF network element, AUSF network element, NEF network element, UPF network element, V-PCF network element, H-PCF network element can also be referred to as AF, UDM, UDR, PCF, SMF, AMF, NRF, AUSF, NEF, UPF, V-PCF, H-PCF respectively.

[0139] In Figure 1, Nausf, Nnef, Nnfr, Namf, Npcf, Nsmf, Nudm, Nudr, and Naf are service-oriented interfaces provided by the aforementioned AUSF, NEF, NRF, AMF, PCF, SMF, UDM, UDR, and AF, respectively, and are used to invoke corresponding service-oriented operations. N1, N2, N3, N4, and N6 are interface serial numbers, and their meanings are as follows:

[0140] 1) N1: The interface between AMF and UE, which can be used to deliver non-access stratum (NAS) signaling (such as QoS rules from AMF) to the UE.

[0141] 2) N2: The interface between AMF and access network equipment, which can be used to transmit radio bearer control information from the core network side to the access network equipment.

[0142] 3) N3: The interface between the access network equipment and UPF, mainly used to transmit uplink and downlink user plane data between the access network equipment and UPF.

[0143] 4) N4: The interface between SMF and UPF, which can be used to transfer information between the control plane and the user plane, including controlling the issuance of forwarding rules, QoS rules, traffic statistics rules, etc. for the user plane and reporting information to the user plane.

[0144] 5) N6: Interface between UPF and DN, used to transmit uplink and downlink user data flows between UPF and DN.

[0145] The above-mentioned network elements or functions can be network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform). As a possible implementation method, the above-mentioned network elements or functions can be implemented by a single device, or by multiple devices, or as a functional module within a single device. This is not specifically limited in the embodiments of the present application. The following describes the communication solution provided in the embodiments of the present application in conjunction with the accompanying drawings.

[0146] Figure 2 is a flow chart of a communication method provided by an embodiment of the present application. In the method flow of Figure 2, when UE1 is non-roaming (i.e., registered in the home network) and UE2 is roaming (i.e., registered in the visited network), AMF2 determines the H-PCF through UDM, and the V-PCF interacts with the H-PCF to obtain the AM policy of UE1, and then determines the AM policy of UE2. As shown in Figure 2, the method includes:

[0147] 201. UE1 in the dual-directional device sends a registration request to AMF1.

[0148] Accordingly, AMF1 receives a registration request sent by UE1 (i.e., the first UE), which may include SUCI1. In this application, a dual-directional device includes a first UE and a second UE. The first UE and the second UE are associated. In other words, the first UE and the second UE have an association relationship, namely a dual-directional (DualSteer) association relationship. A dual-directional association relationship means that the network can switch services between associated terminals, and the address information used by the services before and after the switch remains unchanged. The dual-directional association relationship can be pre-configured. For example, the subscription data of the first UE includes the identification information of the second UE and a dual-directional indication. The first UE and the second UE are two devices that can be included in (located in) the same dual-directional device, such as a chip, a communication module, a USIM, etc. In other words, the first UE and the second UE can be two components of the same dual-directional device, such as a chip, a communication module, a USIM, etc. The first UE and the second UE may not be independent communication devices. The first UE and the second UE may share radio frequency circuits, transceivers, transceiver antennas, etc., or they may not share radio frequency circuits, transceivers, transceiver antennas, etc. For example, a dual-directional device is a terminal device such as a mobile phone or tablet computer that has two associated USIMs inserted, UE1 being one USIM and UE2 being the other USIM.

[0149] In the present application, the first UE can be written as UE1, the second UE can be written as UE2, the first access and mobility management function network element can be written as AMF1, the second access and mobility management function network element can be written as AMF2, the first home location policy control function can be written as H-PCF1, the first visited location policy control function can be written as V-PCF1, and the second visited location policy control function can be written as V-PCF2. For example, the identity identifier used by the first UE is the user permanent identifier (SUPI) 1, and the identity identifiers used by the second UE are SUPI2. In the present application, UE1 and SUPI1 can be replaced with each other, and UE2 and SUPI2 can be replaced with each other.

[0150] In one possible implementation, UE1 (or SUPI1) registers in the home network (e.g., HPLMN), for example, by sending a registration request to AMF1 according to the prior art. The registration request may include UE1's DualSteer capability, a DualSteer indication indicating that UE1 is performing DualSteer registration, and a DualSteer token, which is used for the subsequent registration process of UE2. The registration request may include UE1's subscription concealed identifier (SUCI).

[0151] 202. In response to the registration request from UE1, AMF1 registers with UDM.

[0152] Exemplarily, in response to the registration request from UE1, AMF1 sends a registration request #1 to the UDM. The registration request #1 may include the identity (ID) of AMF1, SUPI1, RAT type, globally unique AMF ID (GUAMI), etc. The GUAMI includes the identification information of the PLMN currently accessed by UE1. In response to the registration request #1, the UDM sends a registration response #1 to the AMF1.

[0153] 203. AMF1 obtains the user subscription data of UE1 from UDM.

[0154] In other words, AMF1 obtains SUPI1's user subscription data (or subscription information) from UDM. In one possible implementation, AMF1 sends a subscription data acquisition request to UDM, where the subscription data acquisition request is used to request UE1's user subscription data. In response to the subscription data acquisition request, UDM sends a subscription data acquisition response to AMF1, where the subscription data acquisition response carries UE1's user subscription data.

[0155] 204. AMF1 selects H-PCF1 for UE1.

[0156] Step 204 is optional.

[0157] 205. AMF1 establishes a policy association for UE1 with H-PCF1.

[0158] The establishment of a policy association of UE1 by AMF1 and H-PCF1 includes: establishing an AM policy association of UE1 and establishing a UE policy association of UE1. The establishment of the AM policy association of UE1 may be: AMF1 sends an AM policy control establishment request message (AMPolicyControl_Creatrequest) to H-PCF1, requesting H-PCF1 to establish an AM policy association with UE1; H-PCF1 sends an AM policy control establishment response message to AMF1. The establishment of a UE policy association of UE1 may be: AMF1 sends a UE policy control establishment request message (UEPolicyControl_Creatrequest) to H-PCF1, requesting H-PCF1 to establish a UE policy association with UE1; H-PCF1 sends a UE policy control establishment response message to AMF1. After H-PCF1 establishes the policy association of UE1 (including the AM policy association and the UE policy association), it can send the generated UE1 policy to UE1.

[0159] 206. When the first trigger condition is met, AMF1 determines (decides) to send the second information to the UDM.

[0160] Accordingly, UDM receives the second information from AMF1. The second information includes the first identification information and the identification information of UE1 (for example, SUPI1). The first identification information is used to identify the home policy control function network element associated with UE1, that is, H-PCF1. The first identification information can be the identification information of the home policy control function network element associated with UE1, such as the ID or address of H-PCF1. The address of H-PCF1 can be an Internet Protocol (IP) address. The first identification information can be named H-PCF1 information. Optionally, the second information also includes first indication information, and the first indication information is used to indicate that the first identification information is used to select the same home policy control function network element for the two UEs in the dual-directional device. The first indication information can be named same PCF indication.

[0161] The first trigger condition includes at least one of the following: knowing (learning) that UE1 has a dual-directional subscription or is authorized for dual-directional subscription, knowing that the registration message of UE1 contains a dual-directional indication and / or dual-directional capability, and knowing that UE1 is the primary UE in the dual-directional device. Exemplarily, AMF1 knows that SUPI1 has a dual-directional subscription based on the subscription data of SUPI1 (UE1). Exemplarily, AMF1 knows that UE1 is performing a dual-directional registration (such as the registration request contains a dual-directional capability, a dual-directional indication, a dual-directional token, etc.) based on the registration request (or registration request message) of UE1 (SUPI1). In a possible implementation, AMF1 knows that UE1 is a primary UE (Primary UE) based on the registration request of UE1, for example, the registration request contains a primary UE indication (Primary UE Indication) to indicate that UE1 is the primary UE. In other words, in one possible implementation, AMF1 learns that SUPI1 is the primary SUPI based on the registration request of SUPI1. For example, the registration request includes a primary SUPI indication, which is used to indicate that SUPI1 is the primary SUPI.

[0162] 207. AMF1 sends second information to UDM.

[0163] Correspondingly, the UDM receives the second information from AMF1. Step 206 is optional. Steps 206 to 207 can be replaced by: when the first trigger condition is met, AMF1 sends the second information to the UDM. In one possible implementation, the AMF sends an update message 1 to the UDM, and the update message 1 includes the second information (i.e., the ID or address of the H-PCF1), SUPI1, and the first indication information (optional). The UDM can be used to store and manage the association between the H-PCF1 and the UE1. The UDM can be replaced by a binding service function (BSF) network element and other network elements that can be used to store and manage the association between the H-PCF and the UE. Optionally, the UDM stores the second information in the UDR so that different UDMs can share the information. In one possible implementation, the second information includes the first identification information and the identification information of UE1 (such as SUPI), and the UDM stores the association between UE1 and the H-PCF1 based on the second information.

[0164] 208. AMF1 sends a registration acceptance message to UE1.

[0165] Correspondingly, UE1 receives a registration accept message from AMF1. After AMF1 receives the registration accept message from AMF1, UE1 registration is completed.

[0166] 209. The dual-directional device decides to register UE2 (or SUPI2).

[0167] The dual-directional device may decide to register SUPI2 based on certain conditions. This application does not limit the conditions that trigger the dual-directional device to decide to register UE2, that is, the triggering conditions for the dual-directional device to decide to register UE2. Step 209 is optional.

[0168] 210. UE2 sends a registration request to AMF2.

[0169] Accordingly, AMF2 receives a registration request from UE2, which includes SUCI2, i.e., UE2's SUCI. In one possible implementation, UE2 registers in a visited network (e.g., a VPLMN) and sends a registration request to AMF2 according to existing techniques. The registration request includes a bidirectional token, which indicates a bidirectional association between UE2 and UE1, i.e., indicates that UE2 and UE1 belong to (are included in) the same bidirectional device.

[0170] 211. In response to the registration request from UE2, AMF2 registers with UDM.

[0171] Step 211 may refer to step 202 .

[0172] 212. AMF2 sends a first request message to UDM.

[0173] Accordingly, the UDM receives a first request message from the AMF2. The first request message is used to request the user subscription data (or subscription information) of the UE2. Alternatively, the first request message is used to request the user subscription data of the SUPI2.

[0174] 213. In response to the first request message, when the second trigger condition is met, the UDM sends a first response message to AMF2.

[0175] Accordingly, AMF2 receives a first response message from the UDM. The first response message includes UE2's subscription information and the first information. The first information may include the first identification information, i.e., the ID or address of H-PCF1. H-PCF1 is the H-PCF associated with UE1. Optionally, the first information also includes the first indication information.

[0176] The second trigger condition includes at least one of the following: knowing that UE2 has a dual-directional subscription and UE2 is associated with UE1 (i.e., SUPI2 is associated with SUPI1), knowing that UE2 is a secondary UE in a dual-directional device, knowing that the network registered by UE1 is different from the network registered by UE2, or the type of wireless access technology used by UE1 is the same as or different from the type of wireless access technology used by UE2. Knowing that the network registered by UE1 is different from the network registered by UE2 can be: knowing that the PLMN currently accessed by UE1 is different from the current PLMN of UE2. In one possible implementation, after receiving the first request message from AMF2, UDM can, in addition to sending UE2's subscription information to AMF2 according to the existing technology, decide to send the ID or address of H-PCF1 (i.e., the first identification information) and the first indication information (optional) to AMF2 according to at least one of the following conditions:

[0177] 1) SUPI2 has a dual-directional contract, and the associated SUPI is SUPI1;

[0178] 2) SUPI2 is the auxiliary SUPI in the dual-directional device;

[0179] 3) The PLMN currently accessed by SUPI1 is different from the PLMN currently accessed by SUPI2;

[0180] 4) The RAT type currently used by SUPI1 is the same as or different from the RAT type currently used by SUPI2.

[0181] For example, if different RFSP policies are desired for UE1 and UE2, the first identification information is only sent when the RAT types of SUPI1 and SUPI2 are the same. The fact that the UDM can send information about the PCF associated with SUPI1 (i.e., the first identification information) clearly indicates that SUPI1 is registered. The UDM can learn about SUPI1 based on SUPI2's subscription information and check UE context information stored locally or by the UDR to determine whether SUPI1 is registered.

[0182] In one possible implementation, UE2's subscription information and the first information are carried in different messages. For example, UE2's subscription information is carried in the first response message, and the first information is carried in another message, not the first response message. Step 213 can be replaced by: in response to the first request message, the UDM sends a first response message to AMF2, the first response message including UE2's subscription information; when the second trigger condition is met, the UDM sends a message 1 to AMF2, the message 1 carrying the first information and SUPI1 (optional).

[0183] 214. AMF2 selects V-PCF2 for UE2, and determines H-PCF1 based on the first information.

[0184] Since UE2 is registered in a visited network (e.g., VPLMN), AMF2 selects V-PCF1 in the VPLMN for UE2. In one possible implementation, in response to the registration request sent by UE2, V-PCF2 in the VPLMN (i.e., the second visited policy control function network element in the claims) is selected for UE2. In one possible implementation, AMF2 determines H-PCF1 based on the first information and the dual-directional subscription information of SUPI2. In one possible implementation, AMF2 determines H-PCF1 in the HPLMN based on the following information: 1) the ID or address of H-PCF1 received from UDM, i.e., the first identification information; 2) optionally, the above-mentioned first indication information; 3) optionally, the dual-directional (DualSteer) subscription information of SUPI2.

[0185] 215. AMF2 sends a first message to V-PCF2.

[0186] Accordingly, V-PCF2 receives the first message from AMF2. The first message is used to request the establishment or modification of the policy association of UE2 in the dual-directional device. The first message may be a policy control establishment request message. The first message includes first identification information (i.e., H-PCF1ID or the address of H-PCF1) and identification information of UE2 (e.g., SUPI2). Optionally, the first message also includes identification information of UE1 (e.g., SUPI1). SUPI1 may be received by V-PCF2 from AMF2, or may be determined based on the DualSteer subscription information of UE1 or UE2 (the subscription information of UE1 and UE2 may be the same).

[0187] 216. V-PCF2 obtains UE1's AM policy from H-PCF1 and forwards UE2's UE policy establishment or modification request.

[0188] In one possible implementation, V-PCF2 obtains the AM policy of UE1 (SUPI1) from H-PCF1 based on SUPI1 and first identification information (i.e., H-PCF1 ID or H-PCF1 address). V-PCF2 receives (and forwards) the UE policy of UE2 (SUPI2) from H-PCF1 based on SUPI2 and the first identification information. A possible implementation of V-PCF2 obtaining UE1's AM policy from H-PCF1 is as follows: V-PCF2 sends a policy acquisition request 1 to H-PCF1. Policy acquisition request 1 is used to obtain UE1's AM policy and may include SUPI1. In response to policy acquisition request 1, H-PCF1 sends UE1's AM policy to V-PCF2.

[0189] 217. V-PCF2 determines the AM policy of UE2 based on the AM policy of UE1.

[0190] This application does not limit the method of determining the UE policy and AM policy of UE2. An example of V-PCF2 determining UE2's AM policy is as follows: V-PCF2 needs to generate an RFSP index (Index) for UE2 that is different from UE1, and V-PCF2 obtains UE1's RFSPIndex from H-PCF1. In this Index, 5G has a higher priority than 4G; then, when V-PCF2 determines UE2's RSFPIndex, 4G is set to have a higher priority than 5G. Another example of V-PCF2 determining UE2's AM policy is as follows: V-PCF2 needs to generate a service area restriction (servicearearestriction) for UE2 that is different from UE1, and V-PCF2 obtains UE1's service area restriction from H-PCF1. Then, V-PCF2 determines that UE2's service area does not include UE1's service area. Another example of V-PCF2 determining UE2's AM policy is as follows: V-PCF2 needs to generate the same service area restriction as UE1 for UE2. V-PCF2 obtains UE1's service area restriction from H-PCF1 and determines it as UE2's service area restriction. An example of V-PCF2 determining UE2's UE policy is as follows: V-PCF2 needs to generate a URSP related to or the same as UE1 for UE2. V-PCF2 obtains UE1's URSP from H-PCF1 and determines it as UE2's. In one possible implementation, step 216 is replaced by: V-PCF2 obtains UE1's AM policy and / or UE policy from H-PCF1; step 217 is replaced by: determining UE2's AM policy and / or UE policy based on UE1's AM policy and / or UE policy. V-PCF2 can obtain UE2's UE policy directly from H-PCF1, or determine UE2's UE policy based on UE1's UE policy, which is not limited in this embodiment of the present application.

[0191] 218. V-PCF2 sends UE2's UE policy and / or AM policy to AMF2.

[0192] 219. AMF2 sends UE2's UE policy and / or AM policy to RAN2 serving UE2.

[0193] Accordingly, RAN2 receives UE2's UE policy and / or AM policy from AMF2. RAN2 serving UE2 sends UE2's UE policy to UE2, and accordingly, UE2 receives UE2's UE policy from RAN2.

[0194] In an embodiment of the present application, when AMF2 selects V-PCF2 for UE2, the ID or address (i.e., the first identification information) of H-PCF1 associated with UE1 is sent to V-PCF2; V-PCF2 obtains UE1's AM policy and UE2's UE policy from H-PCF1, and then determines UE2's AM policy and sends it to UE2; it can determine the associated UE policy and / or AM policy for the two UEs included in the dual-directional device.

[0195] Figure 3 is a flow chart of another communication method provided by an embodiment of the present application. In the method flow of Figure 3, when UE1 is roaming (i.e., registered in the visited network) and UE2 is non-roaming (i.e., registered in the home network), AMF2 determines H-PCF1 through UDM, and H-PCF1 interacts with V-PCF1 (i.e., the V-PCF associated with UE1) to obtain UE1's AM policy, and then determines UE2's AM policy. As shown in Figure 3, the method includes:

[0196] 301. UE1 in the dual-directional device sends a registration request to AMF1.

[0197] In one possible implementation, UE1 registers in a visited network (e.g., a VPLMN), for example, by sending a registration request to AMF1 according to existing techniques. The registration request may include UE1's DualSteer capability, a DualSteer indication indicating that UE1 is performing DualSteer registration, and a DualSteer token. The registration request may also include UE1's SUCI, i.e., SUCI1.

[0198] 302. In response to the registration request from UE1, AMF1 registers with UDM.

[0199] 303. AMF1 obtains the user subscription data of UE1 from UDM.

[0200] Steps 302 to 303 may refer to steps 202 to 203 in FIG. 2 .

[0201] 304. AMF1 selects H-PCF1 and V-PCF1 for UE1.

[0202] Step 304 is optional. In one possible implementation, when AMF1 learns that UE1 is registering in a visited network (e.g., a VPLMN), AMF1 selects H-PCF1 and V-PCF1 for UE1. For example, when UE1 is registering in a visited network (e.g., a VPLMN), AMF1 selects V-PCF1 for UE1 from the VPLMN and H-PCF1 for UE1 from the HPLMN. The manner in which AMF1 selects H-PCF1 and V-PCF1 for UE1 is not limited.

[0203] 305. AMF1 establishes a policy association for UE1 with V-PCF1.

[0204] The establishment of a policy association of UE1 by AMF1 and V-PCF1 includes: establishing an AM policy association of UE1 and establishing a UE policy association of UE1. The establishment of the AM policy association of UE1 may be: AMF1 sends an AM policy control establishment request message (AMPolicyControl_Creatrequest) to V-PCF1, requesting V-PCF1 to establish an AM policy association with UE1; V-PCF1 sends an AM policy control establishment response message to AMF1. The establishment of a UE policy association of UE1 may be: AMF1 sends a UE policy control establishment request message (UEPolicyControl_Creatrequest) to V-PCF1, requesting V-PCF1 to establish a UE policy association with UE1; V-PCF1 sends (forwards) the UE policy control establishment request message sent by AMF1 to H-PCF1; H-PCF1 sends a response message in response to the received UE policy control establishment request message, and V-PCF1 forwards the response message to AMF1. In one possible implementation, V-PCF1 obtains the UE policy of UE1 from H-PCF1.

[0205] 306. When the first trigger condition is met, AMF1 determines to send second information to the UDM.

[0206] The second information includes the first identification information and identification information of UE1 (e.g., SUPI). Optionally, the second information also includes the first indication information and / or the second identification information. The second identification information is used to identify the visited location policy control function network element associated with UE1. The second identification information may be identification information of the visited location policy control function network element associated with UE1, such as the ID or address of V-PCF1.

[0207] In one possible implementation, the first trigger condition includes AMF1 learning that UE1 is registering in a visited network and AMF1 learning at least one of the following: learning (knowing) that UE1 has a dual-directional subscription or is authorized for dual-directional subscription, learning that UE1's registration message contains a dual-directional indication and / or dual-directional capability, or UE1 is the primary UE in a dual-directional device; the second information includes first identification information, UE1's identification information (e.g., SUPI), and second identification information. UE1 registering in a visited network can be replaced by: UE1 registering through the visited network or UE1 registering from a roaming PLMN. In some possible embodiments, upon learning one or more of the following: UE1 has a dual-directional subscription, UE1 is performing a dual-directional registration, or UE1 is the primary UE in a dual-directional device, and UE1 is registering in the visited network, AMF1 determines to send the second information to the UDM; the second information includes the first identification information, UE1's identification information (e.g., SUPI), and the second identification information. In some possible embodiments, when AMF1 learns that UE1 has a dual-directional subscription, UE1 is performing a dual-directional registration, or UE1 is one or more of the primary UEs in the dual-directional device, it determines to send the first identification information and the identification information of UE1 (for example, SUPI1) to the UDM; then, it determines whether UE1 is registered in the visited network, and when it learns that UE1 is registered in the visited network, it determines to send the second identification information to the UDM; when it learns that UE1 is registered in the home network, it determines that the second identification information does not need to be sent to the UDM.

[0208] 307. AMF1 sends second information to UDM.

[0209] Accordingly, the UDM receives the second information from the AMF1. In one possible implementation, the second information includes the first identification information, the identification information of UE1 (e.g., SUPI1), and the second identification information. Based on the second information, the UDM stores the association between UE1 and H-PCF1 and the association between UE1 and V-PCF1.

[0210] 308. AMF1 sends a registration acceptance message to UE1.

[0211] Correspondingly, UE1 receives a registration acceptance message from AMF1.

[0212] 309. The dual-directional device decides to register UE2.

[0213] The dual-directional device may decide to register SUPI2 based on certain conditions. This application does not limit the conditions that trigger the dual-directional device to decide to register UE2, that is, the triggering conditions for the dual-directional device to decide to register UE2. Step 309 is optional.

[0214] 310. UE2 sends a registration request to AMF2.

[0215] Accordingly, AMF2 receives a registration request from UE2, which may include SUCI2. For example, UE2 registers in a home network (e.g., HPLMN), for example, by sending a registration request to AMF2 according to the prior art. The registration request includes a bidirectional token, which is used to indicate a bidirectional association relationship between UE2 and UE1, i.e., indicating that UE2 and UE1 belong to (are included in) the same bidirectional device.

[0216] 311. In response to the registration request from UE2, AMF2 registers with UDM.

[0217] Steps 311 to 313 may refer to steps 211 to 213 in FIG. 2 .

[0218] 312. AMF2 sends a first request message to UDM.

[0219] Accordingly, the UDM receives a first request message from the AMF2. The first request message is used to request the user subscription data (or subscription information) of the UE2. Alternatively, the first request message is used to request the user subscription data of the SUPI2.

[0220] 313. In response to the first request message, when the second trigger condition is met, the UDM sends a first response message to AMF2.

[0221] Accordingly, AMF2 receives a first response message from the UDM. The first response message includes UE2's subscription information and the first information. The first information may include the first identification information, i.e., the ID or address of H-PCF1. H-PCF1 is the H-PCF associated with UE1. Optionally, the first information also includes the first indication information.

[0222] 314. AMF2 determines HPCF1 based on the first information.

[0223] Since UE2 is registered in the home network (e.g., HPLMN), AMF2 may choose to establish a policy association for UE2 with H-PCF1. In one possible implementation, AMF2 determines H-PCF1 based on the first information and the dual-directional subscription information of SUPI2. In one possible implementation, AMF2 determines H-PCF1 in the HPLMN based on the following information: 1) the ID or address of H-PCF1 received from the UDM, i.e., the first identification information; 2) optionally, the first indication information described above; and 3) optionally, the dual-directional (DualSteer) subscription information of SUPI2.

[0224] 315. AMF2 sends a second message to H-PCF1.

[0225] Correspondingly, H-PCF1 receives a second message from AMF2. The second message is used to request the establishment or modification of the policy association of UE2. The second message includes second identification information and / or third identification information. The second identification information is used to identify the visited policy control function network element associated with UE1, that is, V-PCF1. For example, the second identification information is the ID or address of V-PCF1. The third identification information is used to identify UE1. For example, the third identification information is SUPI1. Optionally, the second message also includes identification information of UE2, such as SUPI2. SUPI1 can be received by H-PCF1 from AMF2, or it can be determined based on the DualSteer subscription information of UE1 or UE2 (the subscription information of UE1 and UE2 can be the same).

[0226] 316. H-PCF1 obtains the AM policy of UE1 from V-PCF1 and determines the AM policy of UE2.

[0227] In one possible implementation, based on the third identification information (i.e., SUPI1), the visited location policy control function network element associated with UE1, i.e., V-PCF1, is determined; UE1's AM policy is obtained from V-PCF1, and then UE2's AM policy is determined. Since V-PCF1 sent a policy association request to H-PCF1 during the process of establishing UE1's policy association, and V-PCF1 may have received (and forwarded) UE1's UE policy from H-PCF1, H-PCF1 can know that the visited location policy control function network element associated with UE1 is V-PCF1. In one possible implementation, H-PCF1 obtains UE1's AM policy from V-PCF1 based on the second identification information, and then determines UE2's AM policy. A possible implementation of H-PCF1 obtaining UE1's AM policy from V-PCF1 is as follows: H-PCF1 sends a policy acquisition request 2 to V-PCF1, where the policy acquisition request 2 is used to obtain UE1's AM policy. The policy acquisition request 2 may include SUPI1; V-PCF1 sends UE1's AM policy to H-PCF1 in response to the policy acquisition request 2.

[0228] 317. H-PCF1 determines the UE policy of UE2 according to the UE policy of UE1.

[0229] An example of V-PCF1 determining UE2's AM policy is as follows: V-PCF1 needs to generate an RFSPIndex for UE2 that is different from UE1. V-PCF1 obtains UE1's RFSPIndex from H-PCF1. In this Index, 5G has a higher priority than 4G. Therefore, when V-PCF1 determines UE2's RSFPIndex, 4G is set to have a higher priority than 5G. Another example of V-PCF1 determining UE2's AM policy is as follows: V-PCF1 needs to generate a service area restriction for UE2 that is different from UE1. V-PCF1 obtains UE1's service area restriction from H-PCF1. Therefore, V-PCF1 determines that UE2's service area does not include UE1's service area.

[0230] 318. H-PCF1 sends UE2's UE policy and / or AM policy to AMF2.

[0231] 319. AMF2 sends UE2's UE policy and / or AM policy to RAN2 serving UE2.

[0232] Accordingly, RAN2 receives UE2's UE policy and / or AM policy from AMF2. RAN2 serving UE2 sends UE2's UE policy to UE2. Accordingly, UE2 receives UE2's UE policy from RAN2.

[0233] In an embodiment of the present application, AMF2 determines H-PCF1 and selects H-PCF1 for UE2, and sends the second identification information (i.e., the ID or address of V-PCF1 associated with UE1) and / or the third identification information to H-PCF1; H-PCF1 obtains UE1's AM policy from V-PCF1, and then determines UE2's AM policy, and sends it to UE2; it can determine the associated UE policy and AM policy for the two UEs included in the dual-directional device.

[0234] Figure 4 is a flow chart of another communication method provided by an embodiment of the present application. In the method flow of Figure 4, when UE1 and UE2 roam in the same network, AMF2 determines H-PCF1 (H-PCF associated with UE1) and V-PCF1 (V-PCF associated with UE1) through UDM, and selects V-PCF1 as the visited location policy control function network element for UE2; V-PCF1 receives (and forwards) UE2's UE policy from H-PCF1, and determines UE2's AM policy based on UE1's AM policy. As shown in Figure 4, the method includes:

[0235] 401. UE1 in the dual-directional device sends a registration request to AMF1.

[0236] Steps 401 to 412 may refer to steps 301 to 312 in Figure 3 and are not described in detail here. In one possible implementation, UE1 registers in a visited network (eg, VPLMN1), for example, by sending a registration request to AMF1 according to the prior art.

[0237] 402. In response to the registration request from UE1, AMF1 registers with UDM.

[0238] 403. AMF1 obtains the user subscription data of UE1 from UDM.

[0239] 404. AMF1 selects H-PCF1 and V-PCF1 for UE1.

[0240] 405. AMF1 establishes a policy association for UE1 with V-PCF1.

[0241] In a possible implementation, V-PCF1 obtains the UE policy of UE1 from H-PCF1.

[0242] 406. When the first trigger condition is met, AMF1 determines to send second information to the UDM.

[0243] In one possible implementation, the first trigger condition includes AMF1 learning that UE1 is registered in the visited network and AMF1 learning at least one of the following: learning (knowing) that UE1 has a dual-directional subscription or is authorized for dual-directional, learning that UE1's registration message contains a dual-directional indication and / or dual-directional capability, or UE1 is the master UE in the dual-directional device; the second information includes first identification information (e.g., H-PCF1ID), UE1's identification information (e.g., SUPI), and second identification information (e.g., V-PCF1ID).

[0244] 407. AMF1 sends second information to UDM.

[0245] Accordingly, the UDM receives the second information from the AMF1. The second information may include the first identification information (eg, H-PCF1ID), the identification information of the UE1 (eg, SUPI1), and the second identification information, such as the V-PCF1ID or the address of the V-PCF1.

[0246] 408. AMF1 sends a registration acceptance message to UE1.

[0247] Correspondingly, UE1 receives a registration accept message from AMF1.

[0248] 409. The dual-directional device decides to register UE2 (or SUPI2).

[0249] The dual-directional device may decide to register SUPI2 based on certain conditions. Step 409 is optional.

[0250] 410. UE2 sends a registration request to AMF2.

[0251] Accordingly, AMF2 receives a registration request from UE2, which includes SUCI2. In one possible implementation, UE2 registers in a visited network (e.g., VPLMN1), for example, by sending a registration request to AMF1 according to existing techniques. The registration request includes a bidirectional token, which indicates a bidirectional association between UE2 and UE1, i.e., indicating that UE2 and UE1 belong to (are included in) the same bidirectional device.

[0252] 411. In response to the registration request from UE2, AMF2 registers with UDM.

[0253] 412. AMF2 sends a first request message to UDM.

[0254] Correspondingly, UDM receives the first request message from AMF2.

[0255] 413. In response to the first request message, when the second trigger condition is met, the UDM sends a first response message to AMF2.

[0256] Correspondingly, AMF2 receives the first response message from UDM. The first response message may include UE2's subscription information and the first information. The first information may include the above-mentioned first identification information, that is, the ID or address of H-PCF1, and the above-mentioned second identification information. The second identification information may be the identification information of the V-PCF associated with UE1. For example, the second identification information is V-PCF1ID or the address of V-PCF1. V-PCF1 is the V-PCF associated with UE1. Optionally, the first information also includes the above-mentioned first indication information.

[0257] The second trigger condition includes the UDM learning that UE1 and UE2 are registered in the same visited network, and at least one of the following: learning that UE2 has a dual-directional subscription and is associated with UE1, learning that UE2 is a secondary UE in a dual-directional device, learning that UE1 is registered on a different network than UE2, or learning that the type of radio access technology used by UE1 is the same as or different from that used by UE2. "UE1 and UE2 are registered in the same visited network" can be replaced by: UE1 and UE2 access the same roaming PLMN, V-PLMN1. In one possible implementation, upon learning one or more of the following: UE2 has a dual-directional subscription and is associated with UE1, UE2 is a secondary UE in a dual-directional device, UE1 is registered on a different network than UE2, or the type of radio access technology used by UE1 is the same as or different from that used by UE2, the UDM decides to send UE2's subscription information and first identification information to AMF2. Subsequently, upon learning that UE1 and UE2 are registered in the same visited network, the UDM decides to send the second identification information to AMF2. In some possible embodiments, when UDM learns that UE2 has a dual-directional subscription and UE2 is associated with UE1, UE2 is a secondary UE in a dual-directional device, the network registered by UE1 is different from the network registered by UE2, or the type of wireless access technology adopted by UE1 is the same as or different from the type of wireless access technology adopted by UE2, and UE1 and UE2 are registered in the same visited network, the UDM sends a first response message to the UDM, and the first response message carries the first information and the subscription information of UE2, and the first information includes the first identification information and the second identification information.

[0258] In one possible implementation, UE2's subscription information and the first information are carried in different messages. For example, UE2's subscription information is carried in the first response message, and the first information is carried in another message, not the first response message. Step 413 can be replaced by: in response to the first request message, the UDM sends a first response message to AMF2, the first response message including UE2's subscription information; when the second trigger condition is met, the UDM sends a message 2 to AMF2, the message 2 carrying the first information and SUPI1 (optional).

[0259] 414. AMF2 determines H-PCF1 and V-PCF1.

[0260] In one possible implementation, AMF2 determines the H-PCF1 in the HPLMN and the V-PCF1 in the VPLMN1 based on the first information. Exemplarily, AMF2 determines the H-PCF1 in the HPLMN according to the first identification information, and determines the V-PCF1 in the VPLMN1 according to the second identification information. AMF2 determines V-PCF1 may be that AMF2 selects V-PCF1 for UE2, or in other words, AMF2 chooses to establish a policy association for UE2 with V-PCF1. In one possible implementation, AMF2 determines the H-PCF1 in the HPLMN based on the following information: 1) the ID or address of H-PCF1 received from UDM, that is, the first identification information; 2) optionally, the above-mentioned first indication information; 3) optionally, the dual-directional (DualSteer) subscription information of SUPI2.

[0261] 415. AMF2 sends a first message to V-PCF1.

[0262] Accordingly, V-PCF1 receives a first message from AMF2. The first message is used to request establishment or modification of a policy association for UE2. The first message includes first identification information (e.g., H-PCF1 ID) and identification information of UE2, such as SUPI2. Optionally, the first message also includes identification information of UE1, such as SUPI1.

[0263] 416. V-PCF1 obtains UE policy of UE2 from H-PCF1.

[0264] In a possible implementation, V-PCF1 obtains the UE policy of UE2 (SUPI2) from H-PCF1 according to SUPI2 and the first identification information.

[0265] 417. V-PCF1 determines the AM policy of UE2 based on the AM policy of UE1.

[0266] Step 417 may refer to step 217 in Figure 2. Since V-PCF1 is the V-PCF associated with UE1, that is, the AM policy of UE1 is determined by V-PCF1, V-PCF1 can learn the AM policy of UE1.

[0267] 418. V-PCF1 sends UE2's UE policy and / or AM policy to AMF2.

[0268] 419. AMF2 sends UE2's UE policy and / or AM policy to RAN2 serving UE2.

[0269] Accordingly, RAN2 receives UE2's UE policy and / or AM policy from AMF2. RAN2 serving UE2 sends UE2's UE policy to UE2. Accordingly, UE2 receives UE2's UE policy from RAN2.

[0270] In an embodiment of the present application, AMF2 determines H-PCF1 (H-PCF associated with UE1) and V-PCF1 (V-PCF associated with UE1) through UDM, and selects V-PCF1 for UE2; V-PCF1 obtains UE2's UE policy from H-PCF1, and determines UE2's AM policy based on UE1's AM policy; and can determine the associated UE policy and AM policy for the two UEs included in the dual-directional device.

[0271] FIG5 is a flow chart of another communication method provided by an embodiment of the present application. In the method flow of FIG5 , when UE1 and UE2 are roaming in different networks, AMF2 determines H-PCF1 (i.e., the H-PCF associated with UE1) through UDM and selects V-PCF2 for UE2. V-PCF2 obtains UE1's AM policy determined by V-PCF1 from H-PCF1, and then determines UE2's AM policy. As shown in FIG5 , the method includes:

[0272] 501. UE1 in the dual-directional device sends a registration request to AMF1.

[0273] Steps 501 to 504 may refer to steps 301 to 304 in Figure 3 and are not described in detail here. In one possible implementation, UE1 registers in a visited network (eg, VPLMN1), for example, by sending a registration request to AMF1 according to the prior art.

[0274] 502. In response to the registration request from UE1, AMF1 registers with UDM.

[0275] 503. AMF1 obtains the user subscription data of UE1 from UDM.

[0276] 504. AMF1 selects H-PCF1 and V-PCF1 for UE1.

[0277] 505A. AMF1 establishes a policy association for UE1 with V-PCF1.

[0278] In a possible implementation, V-PCF1 receives (and forwards) the UE policy of UE1 from H-PCF1. Step 505A can refer to step 305 in FIG3 .

[0279] 505B. H-PCF1 sends a first AM policy subscription message to V-PCF1.

[0280] Correspondingly, V-PCF1 receives the first AM policy subscription message from H-PCF1. The first AM policy subscription message is used to subscribe UE1's AM policy to V-PCF1.

[0281] 505C. V-PCF1 sends UE1's AM policy to H-PCF1.

[0282] In one possible implementation, after V-PCF1 receives the first AM policy subscription message, it can send UE1's AM policy to H-PCF1; when UE1's AM policy changes, in response to the first AM policy subscription message, it sends a first policy change message to H-PCF1, and the first policy change message includes UE1's changed AM policy.

[0283] 506. When the first trigger condition is met, AMF1 determines to send second information to the UDM.

[0284] Steps 506 to 512 may refer to steps 406 to 412 in FIG. 4 .

[0285] 507. AMF1 sends second information to UDM.

[0286] Accordingly, the UDM receives the second information from the AMF1. The second information may include the first identification information (eg, H-PCF1 ID), the identification information of the UE1 (eg, SUPI), and the second identification information, such as the V-PCF1 ID or the address of the V-PCF1.

[0287] 508. AMF1 sends a registration acceptance message to UE1.

[0288] Correspondingly, UE1 receives a registration acceptance message from AMF1.

[0289] 509. The dual-directional device decides to register UE2.

[0290] The dual-directional device may decide to register SUPI2 based on certain conditions. Step 509 is optional.

[0291] 510. UE2 sends a registration request to AMF2.

[0292] Accordingly, AMF2 receives a registration request from UE2, which may include SUCI2. In one possible implementation, UE2 registers in a visited network (eg, VPLMN2), for example, by sending a registration request to AMF1 according to the prior art.

[0293] 511. In response to the registration request from UE2, AMF2 registers with UDM.

[0294] 512. AMF2 sends a first request message to UDM.

[0295] Correspondingly, UDM receives the first request message from AMF2.

[0296] 513. In response to the first request message, when the second trigger condition is met, the UDM sends a first response message to AMF2.

[0297] Accordingly, AMF2 receives a first response message from the UDM. The first response message may include UE2's subscription information and the first information. The first information may include the first identification information, i.e., the ID or address of H-PCF1. Optionally, the first information also includes the first indication information.

[0298] In one possible implementation, the second trigger condition includes at least one of the following: learning that UE2 has a dual-directional subscription and is associated with UE1, learning that UE2 is a secondary UE in a dual-directional device, learning that the network registered by UE1 is different from the network registered by UE2, or learning that the type of radio access technology used by UE1 is the same as or different from the type of radio access technology used by UE2; the first response message may include UE2's subscription information and first information, the first information including the above-mentioned first identification information but not including the above-mentioned second identification information. In other words, in addition to sending UE2's subscription information to AMF2 according to the existing technology, the UDM also decides to send the above-mentioned first identification information and first indication information (optional) to AMF2 upon learning one or more of the following: UE2 has a dual-directional subscription and is associated with UE1, UE2 is a secondary UE in a dual-directional device, the network registered by UE1 is different from the network registered by UE2, or the type of radio access technology used by UE1 is the same as or different from the type of radio access technology used by UE2.

[0299] In one possible implementation, the second trigger condition includes UDM learning that the PLMNs accessed by UE1 and UE2 are both roaming PLMNs but are different (for example, UE1 accesses V-PLMN1, and UE2 accesses V-PLMN2), and at least one of the following: learning that UE2 has a dual-directional subscription and UE2 is associated with UE1, learning that UE2 is a secondary UE in a dual-directional device, learning that the network registered by UE1 is different from the network registered by UE2, or learning that the type of wireless access technology adopted by UE1 is the same as or different from the type of wireless access technology adopted by UE2; the first information includes the above-mentioned first identification information, but does not include the above-mentioned second identification information.

[0300] In one possible implementation, UE2's subscription information and the first information are carried in different messages. For example, UE2's subscription information is carried in the first response message, and the first information is carried in another message, not the first response message. Step 516 can be replaced by: in response to the first request message, the UDM sends a first response message to AMF2, the first response message including UE2's subscription information; when the second trigger condition is met, the UDM sends a message 2 to AMF2, the message 2 carrying the first information and SUPI1 (optional).

[0301] 514. AMF2 determines H-PCF1 and selects V-PCF2.

[0302] In one possible implementation, AMF2 determines the H-PCF1 in the HPLMN based on the following information: 1) the ID or address of H-PCF1 received from the UDM, i.e., the first identification information; 2) optionally, the first indication information described above; and 3) optionally, the DualSteer subscription information of SUPI2. In one possible implementation, AMF2 selects V-PCF2 in VPLMN2.

[0303] 515. AMF2 sends a first message to V-PCF2.

[0304] Accordingly, V-PCF2 receives a first message from AMF2. The first message is used to request establishment or modification of a policy association for UE2. The first message includes first identification information (e.g., H-PCF1ID) and identification information of UE2, such as SUPI2. Optionally, the first message also includes identification information of UE1, such as SUPI1.

[0305] 516. V-PCF2 obtains UE1's AM policy from H-PCF1, and receives (and forwards) UE2's UE policy.

[0306] In one possible implementation, V-PCF2 obtains the AM policy of UE1 (SUPI1) from H-PCF1 based on SUPI1 and the first identification information; V-PCF2 obtains the UE policy of UE2 (SUPI2) from H-PCF1 based on SUPI2 and the first identification information.

[0307] 517. V-PCF2 determines the AM policy of UE2 based on the AM policy of UE1.

[0308] Step 517 may refer to step 217 in FIG. 2 .

[0309] 518A. H-PCF1 sends a second AM policy subscription message to V-PCF2.

[0310] Correspondingly, V-PCF2 receives the second AM policy subscription message from H-PCF1. The second AM policy subscription message is used to subscribe UE2's AM policy to V-PCF2.

[0311] 518B. V-PCF2 sends UE2's AM policy to H-PCF1.

[0312] In one possible implementation, when UE2's AM policy changes, a second policy change message is sent to H-PCF1 in response to the second AM policy subscription message. The second policy change message includes UE2's changed AM policy. The beneficial effect of H-PCF1 subscribing to UE2's AM policy from V-PCF2 and UE1's AM policy from V-PCF1 is that if the policy of UE1 or UE2 changes, the VPCF (including V-PCF1 and V-PCF1) can notify the H-PCF, which then notifies the other V-PCF to synchronize the policy updates for the other UE. Steps 518A and 518B are optional.

[0313] 519. V-PCF2 sends UE2's UE policy and / or AM policy to AMF2.

[0314] 520. AMF2 sends UE2's UE policy and / or AM policy to RAN2 serving UE2.

[0315] Accordingly, RAN2 serving UE2 receives UE2's UE policy and / or AM policy from AMF2. RAN2 serving UE2 sends UE2's UE policy to UE2. Accordingly, UE2 receives UE2's UE policy from RAN2.

[0316] In an embodiment of the present application, when UE1 and UE2 roam in different networks, AMF2 determines H-PCF1 through UDM, and V-PCF2 selected by AMF2 for UE obtains UE1's AM policy and UE2's UE policy from H-PCF1, and then determines UE2's AM policy based on UE1's AM policy; it is capable of determining the associated UE policy and AM policy for the two UEs included in the dual-directional device.

[0317] Figure 6 is a flow chart of another communication method provided by an embodiment of the present application. In the method flow of Figure 6, when UE1 and UE2 roam in different networks, AMF2 determines H-PCF1 through UDM, and V-PCF2 selected by AMF2 for UE receives (and forwards) UE2's UE policy from H-PCF1 and directly obtains UE1's AM policy from V-PCF1 (V-PCF associated with UE). The difference between the method of Figure 6 and the method of Figure 5 is whether H-PCF is used as a centralization point or forwarding point for AM policy. In other words, in the method flow of Figure 5, V-PCF2 obtains UE1's AM policy from H-PCF1; in the method flow of Figure 6, V-PCF2 obtains UE1's AM policy from V-PCF1. As shown in Figure 6, the method includes:

[0318] 601. UE1 in the dual-directional device sends a registration request to AMF1.

[0319] The registration request includes SUCI1. Steps 601 to 604 can refer to steps 501 to 504 in Figure 5 and are not repeated here. In one possible implementation, UE1 registers in a visited network (e.g., VPLMN1), for example, by sending a registration request to AMF1 according to the prior art.

[0320] 602. In response to the registration request from UE1, AMF1 registers with UDM.

[0321] 603. AMF1 obtains the user subscription data of UE1 from UDM.

[0322] 604. AMF1 selects H-PCF1 and V-PCF1 for UE1.

[0323] 605. AMF1 establishes a policy association for UE1 with V-PCF1.

[0324] 606. When the first trigger condition is met, AMF1 determines to send second information to the UDM.

[0325] Steps 606 to 612 may refer to steps 506 to 512 in FIG. 5 .

[0326] 607. AMF1 sends second information to UDM.

[0327] Accordingly, the UDM receives the second information from the AMF1. The second information may include the first identification information (eg, H-PCF1 ID), the identification information of the UE1 (eg, SUPI), and the second identification information, such as the V-PCF1 ID or the address of the V-PCF1.

[0328] 608. AMF1 sends a registration acceptance message to UE1.

[0329] Correspondingly, UE1 receives a registration acceptance message from AMF1.

[0330] 609. The dual-directional device decides to register UE2.

[0331] The dual-directional device may decide to register SUPI2 based on certain conditions. Step 609 is optional.

[0332] 610. UE2 sends a registration request to AMF2.

[0333] Accordingly, AMF2 receives a registration request from UE2, which may include SUCI2. In one possible implementation, UE2 registers in a visited network (eg, VPLMN2), for example, by sending a registration request to AMF1 according to the prior art.

[0334] 611. In response to the registration request from UE2, AMF2 registers with UDM.

[0335] 612. AMF2 sends a first request message to UDM.

[0336] Correspondingly, UDM receives the first request message from AMF2.

[0337] 613. In response to the first request message, when the second trigger condition is met, the UDM sends a first response message to AMF2.

[0338] Accordingly, AMF2 receives a first response message from the UDM. The first response message may include UE2's subscription information and the first information. The first information may include the first identification information, i.e., the ID or address of H-PCF1, and the second identification information, i.e., the ID or address of V-PCF1. Optionally, the first information also includes the first indication information.

[0339] In one possible implementation, the second trigger condition includes UDM learning that the PLMNs accessed by UE1 and UE2 are both roaming PLMNs but are different (for example, UE1 accesses V-PLMN1, and UE2 accesses V-PLMN2), and at least one of the following: learning that UE2 has a dual-directional subscription and UE2 is associated with UE1, learning that UE2 is a secondary UE in a dual-directional device, learning that the network registered by UE1 is different from the network registered by UE2, or learning that the type of wireless access technology adopted by UE1 is the same as or different from the type of wireless access technology adopted by UE2; the first information includes the above-mentioned first identification information and the above-mentioned second identification information.

[0340] 614. AMF2 determines H-PCF1 and selects V-PCF2.

[0341] Step 614 may refer to step 514 in FIG. 5 .

[0342] 615. AMF2 sends a first message to V-PCF2.

[0343] Accordingly, V-PCF2 receives a first message from AMF2. The first message is used to request establishment or modification of a policy association for UE2. The first message includes first identification information (e.g., H-PCF1ID), identification information for UE2 (e.g., SUPI2), and second identification information (e.g., V-PCF1ID). Optionally, the first message also includes identification information for UE1, e.g., SUPI1.

[0344] 616. V-PCF2 obtains UE policy of UE2 from H-PCF1.

[0345] In a possible implementation, V-PCF2 obtains the UE policy of UE2 (SUPI2) from H-PCF1 according to SUPI2 and the first identification information.

[0346] 617A. V-PCF2 obtains UE1's AM policy from V-PCF1.

[0347] A possible implementation of V-PCF2 obtaining UE1's AM policy from V-PCF1 is as follows: V-PCF2 sends a policy acquisition request 3 to V-PCF1, where the policy acquisition request 3 is used to obtain UE1's AM policy. The policy acquisition request 3 may include SUPI1; V-PCF1 sends UE1's AM policy to V-PCF2 in response to the policy acquisition request 3.

[0348] 617B. V-PCF2 determines the AM policy of UE2 based on the AM policy of UE1.

[0349] Step 617B may refer to step 217 in FIG. 2 .

[0350] 618. V-PCF2 sends UE2's UE policy and / or AM policy to AMF2.

[0351] 619. AMF2 sends UE2's UE policy and / or AM policy to RAN2 serving UE2.

[0352] Accordingly, RAN2 receives UE2's UE policy and / or AM policy from AMF2. RAN2 serving UE2 sends UE2's UE policy to UE2. Accordingly, UE2 receives UE2's UE policy from the RAN.

[0353] Figure 7 is a flow chart of another communication method provided by an embodiment of the present application. In the method flow of Figure 7, when AMF1 selects PCF1 for UE1 and AMF2 selects PCF2 for UE2, PCF2 interacts with PCF1 to obtain UE1's AM policy / UE policy. The method of Figure 7 can be applied to scenarios where both UE1 and UE2 are non-roaming. As shown in Figure 7, the method includes:

[0354] 701. UE1 in the dual-directional device sends a registration request to AMF1.

[0355] Accordingly, AMF1 receives a registration request sent by UE1 (ie, the first UE), which may include SUCI 1. Steps 701 to 713 may refer to steps 201 to 213 in FIG. 2 .

[0356] 702. In response to the registration request from UE1, AMF1 registers with UDM.

[0357] 703. AMF1 obtains the user subscription data of UE1 from UDM.

[0358] 704. AMF1 selects PCF1 for UE1.

[0359] Step 704 is optional. PCF1 can be an H-PCF in an HPLMN or a V-PCF in a VPLMN.

[0360] 705. AMF1 establishes a policy association for UE1 with PCF1.

[0361] 706. When the first trigger condition is met, AMF1 determines to send second information to the UDM.

[0362] The second information includes the first identification information and the identification information of UE1 (e.g., SUPI). The first identification information is used to identify the home policy control function network element associated with UE1, namely, PCF1. The first identification information can be the identification information of the home policy control function network element associated with UE1, such as the ID or address of PCF1.

[0363] 707. AMF1 sends second information to UDM.

[0364] Correspondingly, the UDM receives the second information from the AMF1. The second information includes the first identification information (eg, the ID or address of the PCF1) and the identification information of the UE1 (eg, SUPI1).

[0365] 708. AMF1 sends a registration acceptance message to UE1.

[0366] 709. The dual-directional device decides to register UE2.

[0367] 710. UE2 sends a registration request to AMF2.

[0368] Accordingly, AMF2 receives a registration request from UE2, which may include SUCI2.

[0369] 711. In response to the registration request from UE2, AMF2 registers with UDM.

[0370] 712. AMF2 sends a first request message to UDM.

[0371] Correspondingly, UDM receives the first request message from AMF2.

[0372] 713. In response to the first request message, when the second trigger condition is met, the UDM sends a first response message to AMF2.

[0373] Accordingly, AMF2 receives a first response message from the UDM. The first response message includes UE2's subscription information and the first information. The first information includes the first identification information, i.e., the ID or address of PCF1. Optionally, the first information also includes the first indication information.

[0374] 714. AMF2 selects PCF2 for UE2.

[0375] PCF2 can be the H-PCF in the HPLMN or the V-PCF in the VPLMN.

[0376] 715A. AMF2 sends a first message to PCF2.

[0377] Accordingly, PCF2 receives the first message from AMF2. The first message is used to request the establishment or modification of a policy association for UE2 in a dual-directional device. In one possible implementation, the first message includes first identification information (e.g., PCF1ID), identification information of UE2 (e.g., SUPI2), and identification information of UE1 (e.g., SUPI1). In one possible implementation, the first message includes identification information of UE2 (e.g., SUPI2) and identification information of UE1 (e.g., SUPI1); PCF2 uses SUPI1 to obtain the ID or address of PCF1 bound to SUPI1 from the BSF.

[0378] 715B. PCF2 obtains the policy of UE1 from PCF1 according to the identification information of UE1 and the first identification information.

[0379] 715C. PCF2 determines the policy of UE2 based on the policy of UE1.

[0380] 716. PCF2 sends UE2's UE policy and / or AM policy to AMF2.

[0381] 717. AMF2 sends UE2's UE policy and / or AM policy to RAN2 serving UE2.

[0382] Accordingly, RAN2 receives UE2's UE policy and / or AM policy from AMF2. RAN2 sends UE2's policy to UE2. Accordingly, UE2 receives UE2's policy from RAN2.

[0383] In an embodiment of the present application, when AMF1 selects PCF1 for UE1 and AMF2 selects PCF2 for UE2, PCF2 interacts with PCF1 to obtain the AM policy / UE policy of UE1; and can determine the associated UE policy and / or AM policy for the two UEs included in the dual-directional device.

[0384] FIG8 is a flow chart of another communication method provided by an embodiment of the present application. In the method flow of FIG8 , when UE1 and UE2 are both non-roaming, AMF2 selects PCF1 associated with UE1 for UE2. The method of FIG8 can be applied to scenarios where both UE1 and UE2 are non-roaming. As shown in FIG8 , the method includes:

[0385] 801. UE1 in the dual-directional device sends a registration request to AMF1.

[0386] Accordingly, AMF1 receives the registration request sent by UE1, which may include SUCI1. Steps 801 to 813 may refer to steps 201 to 213 in Figure 2. In one possible implementation, UE1 registers in the home network (HPLMN), for example, by sending a registration request to AMF1 according to the prior art.

[0387] 802. In response to the registration request from UE1, AMF1 registers with UDM.

[0388] 803. AMF1 obtains the user subscription data of UE1 from UDM.

[0389] 804. AMF1 selects PCF1 for UE1.

[0390] Step 804 is optional. In one possible implementation, AMF1 selects PCF1 in the HPLMN for UE1.

[0391] 805. AMF1 establishes a policy association for UE1 with PCF1.

[0392] 806. When the first trigger condition is met, AMF1 determines to send second information to the UDM.

[0393] Accordingly, the UDM receives second information from AMF1. The second information includes first identification information (e.g., the ID or address of PCF1) and identification information of UE1 (e.g., SUPI). The first identification information is used to identify the home policy control function network element associated with UE1, namely, PCF1. Optionally, the second information also includes first indication information, which indicates that the first identification information is used to select the same home policy control function network element for the two UEs in the dual-directional device.

[0394] 807. AMF1 sends second information to UDM.

[0395] The second information includes first identification information (eg, ID or address of PCF1) and identification information of UE1 (eg, SUPI).

[0396] 808. AMF1 sends a registration acceptance message to UE1.

[0397] 809. The dual-directional device decides to register UE2.

[0398] 810. UE2 sends a registration request to AMF2.

[0399] In one possible implementation, UE2 registers in the home network (HPLMN), for example, by sending a registration request to AMF2 according to the prior art, where the registration request may include SUCI2.

[0400] 811. In response to the registration request from UE2, AMF2 registers with UDM.

[0401] 812. AMF2 sends a first request message to UDM.

[0402] 813. In response to the first request message, when the second trigger condition is met, the UDM sends a first response message to AMF2.

[0403] The first response message includes the subscription information of UE2 and the first information. The first information may include the first identification information, ie, the ID or address of PCF1. PCF1 is the H-PCF associated with UE1. Optionally, the first information also includes the first indication information.

[0404] 814. AMF2 selects PCF1 for UE2.

[0405] In one possible implementation, AMF2 selects PCF1 for UE2 based on the first identification information. AMF2 can select PCF1 associated with UE1 for UE2; in this way, PCF1 can determine the policy associated with UE2 without interaction.

[0406] 815. AMF2 sends a second message to PCF1.

[0407] Correspondingly, PCF1 receives a second message from AMF2. The second message is used to request to establish or modify a policy association of UE2.

[0408] 816. PCF1 determines the UE policy and / or AM policy of UE2.

[0409] 817. PCF1 sends UE2's UE policy and / or AM policy to AMF2.

[0410] 818. AMF2 sends UE2's UE policy and / or AM policy to RAN2 serving UE2.

[0411] Accordingly, RAN2 receives UE2's UE policy and / or AM policy from AMF2. RAN2 sends UE2's policy to UE2. Accordingly, UE2 receives UE2's policy from RAN2.

[0412] In the embodiment of the present application, AMF2 selects PCF1 for UE2, that is, selects the same PCF for UE2 and UE; in this way, PCF1 can determine the policy associated with UE2 without interaction.

[0413] FIG9 is a flow chart of another communication method provided by an embodiment of the present application. In the method flow of FIG9 , the AMF selects the same PCF for UE1 and UE2. As shown in FIG9 , the method includes:

[0414] 901. UE1 in the dual-directional device sends a registration request to AMF1.

[0415] Accordingly, AMF1 receives the registration request sent by UE1, which may include SUCI1. Steps 901 to 905 can refer to steps 201 to 205 in Figure 2. In one possible implementation, UE1 registers in the home network (HPLMN), for example, by sending a registration request to AMF1 according to the prior art.

[0416] 902. In response to the registration request from UE1, AMF1 registers with UDM.

[0417] 903. AMF1 obtains the user subscription data of UE1 from UDM.

[0418] 904. AMF1 selects PCF1 for UE1.

[0419] Step 804 is optional. In one possible implementation, AMF1 selects PCF1 in the HPLMN for UE1.

[0420] 905. AMF1 establishes a policy association for UE1 with PCF1.

[0421] 906. AMF1 sends a registration acceptance message to UE1.

[0422] 907. The dual-directional device decides to register UE2.

[0423] Step 907 is optional.

[0424] 908. UE2 sends a registration request to AMF2.

[0425] Accordingly, AMF2 receives a registration request from UE2, which may include SUCI2. The registration request may carry a token. The token may be UE1's 5G globally unique temporary UE identifier (5G-GUTI). The 5G-GUTI includes AMF1 information.

[0426] 909. In response to the registration request from UE2, AMF2 registers with UDM.

[0427] 910. AMF2 obtains UE2's contract information from UDM.

[0428] 911. When the third trigger condition is met, AMF2 sends a second request message to AMF1.

[0429] Correspondingly, AMF1 receives a second request message from AMF2. The above-mentioned second request message is used to request the identification information of the PCF associated with UE1. The second request message includes SUPI1. In one possible implementation, the third trigger condition includes at least one of the following: knowing that UE2 has a dual-directional subscription and UE2 is associated with UE1, knowing that UE2 is performing a dual-directional registration, and knowing that UE2 is a secondary UE in a dual-directional device. Exemplarily, AMF2 decides to send a second request message to AMF1 based on the 5G-GUTI in the UE2 registration message and one or more of the following conditions: 1) According to the subscription data of SUPI2, it is known that SUPI2 has a dual-directional subscription and the associated SUPI is SUPI1; 2) According to the registration message of SUPI2, it is known that SUPI2 is performing a dual-directional registration (such as the registration message contains dual-directional capability, dual-directional indication, dual-directional token, etc.); 3) According to the registration message of SUPI2, it is known that SUPI2 is a secondary SUPI (such as the registration message contains a secondary SUPI indication).

[0430] 912. AMF1 sends a second response message to AMF2.

[0431] Correspondingly, the second response message receives the second response message from AMF1. In response to the second request message, AMF1 sends a second response message to AMF2. The second response message includes the identification information of the PCF associated with UE1, that is, the ID or IP of PCF1.

[0432] 913. AMF2 selects PCF1 to associate the policy of UE2.

[0433] In one possible implementation, AMF2 selects PCF1 for policy association of UE2 based on the identification information of the PCF associated with UE1.

[0434] 914. AMF2 sends a second message to PCF1.

[0435] Correspondingly, PCF1 receives a second message from AMF2. The second message is used to request to establish or modify a policy association of UE2.

[0436] 915. PCF1 determines the UE policy and / or AM policy of UE2.

[0437] 916. PCF1 sends UE2's UE policy and / or AM policy to AMF2.

[0438] 917. AMF2 sends UE2's UE policy and / or AM policy to RAN2 serving UE2.

[0439] Accordingly, RAN2 receives UE2's UE policy and / or AM policy from AMF2. RAN2 sends UE2's policy to UE2. Accordingly, UE2 receives UE2's policy from RAN2.

[0440] In an embodiment of the present application, AMF2 obtains the identification information of PCF1 associated with UE1 from AMF1, and selects PCF1 for policy association of UE2; it can determine the associated UE policy and / or AM policy for the two UEs included in the dual-directional device.

[0441] FIG10 is a flow chart of another communication method provided in an embodiment of the present application. As shown in FIG10 , the method includes:

[0442] 1001. AMF1 determines the AM policy of UE1.

[0443] Part of the AM policy can ultimately be determined by the AMF based on the AM policy generated by the PCF. AMF1 can further determine the AM policy of UE1 based on the AM policy of UE1 generated by the PCF, such as the RFSP index in use and the service area in use.

[0444] 1002. The dual-directional device decides to register UE2.

[0445] Step 1002 is optional.

[0446] 1003. UE2 sends a registration request to AMF2.

[0447] Accordingly, AMF2 receives a registration request from UE2, which may include SUCI2. The registration request may carry a token, which may be UE1's 5G-GUTI.

[0448] 1004A. When the third trigger condition is met, AMF2 sends a third request message to AMF1.

[0449] Accordingly, AMF1 receives a third request message from AMF2. The third request message includes SUPI1. The third request message is used to request UE1's policy, such as the RFSP index in use and the service area in use. AMF2 obtains SUPI1's policy from AMF1 based on SUPI1's 5G-GUTI.

[0450] 1004B. AMF1 sends a third response message to AMF2.

[0451] Correspondingly, AMF2 receives a third response message from AMF1, which includes the policy of UE1.

[0452] 1005. AMF2 establishes a policy association with PCF2.

[0453] Optionally, AMF2 uses SUPI1's policy as input for PCF2 to generate SUPI2's policy. PCF2 then generates SUPI2's policy based on SUPI1's policy. In one possible implementation, AMF2 sends a third message to PCF2, which is used to establish a policy association with PCF2 and includes SUPI1's policy. PCF2 then generates SUPI2's policy based on SUPI1's policy and sends a fourth message to AMF2, which includes SUPI2's policy. Step 1005 is optional.

[0454] 1006. AMF2 determines the policy of UE2 based on the policy of UE1.

[0455] Step 1005 is optional.

[0456] 1007. AMF2 sends UE2's policy to RAN2 serving UE2.

[0457] Accordingly, RAN2 receives UE2's policy from AMF2. RAN2 sends UE2's policy to UE2. Accordingly, UE2 receives UE2's policy from RAN2.

[0458] Figure 10 may include at least one of step 1005 and step 1006. When Figure 10 includes step 1005 but excludes step 1006, AMF2 sends the policy for UE2 generated by PCF2 to the RAN serving UE2. When Figure 10 includes step 1006 but excludes step 1005, AMF2 sends the policy for UE2 determined by AMF2 based on the policy of U1 to the RAN serving UE2. When Figure 10 includes both step 1006 and step 1005, AMF2 sends the policy for UE2 determined based on the policy generated by PCF2 to the RAN serving UE2.

[0459] In an embodiment of the present application, AMF2 obtains the policy of UE1 from AMF1, and then determines the policy of UE2; it can determine the associated UE policy and AM policy for the two UEs included in the dual-directional device.

[0460] It should be understood that in the various embodiments of the present application, unless otherwise specified and there is no logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships. The above embodiments describe how the network (core network) determines the associated UE policy and AM policy for the two UEs included in the dual-directional device under different scenarios. The technical solution provided in this application can be applied to scenarios where one or both UEs in the dual-directional device access through roaming, and can also be applied to scenarios where both UEs in the dual-directional device access through non-roaming. In actual applications, the above multiple embodiments can be combined with each other.

[0461] It should also be understood that in some of the above embodiments, devices in existing network architectures are mainly used as examples for illustrative purposes, and it should be understood that the embodiments of the present application do not limit the specific form of the devices. For example, devices that can achieve the same functions in the future are applicable to the embodiments of the present application.

[0462] It can be understood that in the above-mentioned method embodiments, the methods and operations implemented by devices (such as AMF1, AMF2, UDM, PCF, etc.) can also be implemented by components that can be used in the devices (such as chips or circuits).

[0463] It can also be understood that some optional features in the various embodiments of the present application may not depend on other features in certain scenarios, and may also be combined with other features in certain scenarios, without limitation.

[0464] Those skilled in the art should be aware that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0465] The following describes the structure of a communication device that can implement the communication method provided in the embodiments of the present application in conjunction with the accompanying drawings. The following only briefly describes the communication device. For details on the implementation of the solution, please refer to the description of the method embodiment above, which will not be repeated below.

[0466] Figure 11 is a structural diagram of a communication device 1100 provided in an embodiment of the present application. The communication device 1100 can correspond to the functions or steps implemented by AMF1 in each of the above-mentioned method embodiments, and can also correspond to the functions or steps implemented by AMF2 in each of the above-mentioned method embodiments, and can also correspond to the functions or steps implemented by UDM in each of the above-mentioned method embodiments, and can also correspond to the functions or steps implemented by H-PCF1 in each of the above-mentioned method embodiments, and can also correspond to the functions or steps implemented by V-PCF1 in each of the above-mentioned method embodiments, and can also correspond to the functions or steps implemented by V-PCF2 in each of the above-mentioned method embodiments, and can also correspond to the functions or steps implemented by PCF1 in each of the above-mentioned method embodiments, and can also correspond to the functions or steps implemented by PCF2 in each of the above-mentioned method embodiments. The communication device may include a processing module 1110 and a transceiver module 1120. In one possible implementation, it may also include a storage unit, which can be used to store instructions (codes or programs) and / or data. The processing module 1110 and the transceiver module 1120 can be coupled to the storage unit. For example, the processing module 1110 can read instructions (code or program) and / or data in the storage unit to implement the corresponding method. The above-mentioned units can be independently provided or partially or fully integrated. For example, the transceiver module 1120 may include a transmitting module and a receiving module. The transmitting module may be a transmitter, and the receiving module may be a receiver. The entity corresponding to the transceiver module 1120 may be a transceiver circuit, such as a transceiver or a communication interface.

[0467] In some possible implementations, the communication device 1100 can implement the corresponding behaviors and functions of the AMF1 in the above-described method embodiments. For example, the communication device 1100 can be the AMF1, or a component (e.g., a chip or circuit) used in the AMF1. The transceiver module 1120 can, for example, be used to perform all receiving or transmitting operations performed by the AMF1 in the embodiments of Figures 2 to 10. The processing module 1110 can, for example, be used to perform all operations performed by the AMF1 in the embodiments of Figures 2 to 10 except for the transmitting and receiving operations.

[0468] In some possible implementations, the communication device 1100 can implement the corresponding behaviors and functions of the AMF2 in the above-described method embodiments. For example, the communication device 1100 can be an AMF2, or a component (e.g., a chip or circuit) used in the AMF2. The transceiver module 1120 can, for example, be used to perform all receiving or transmitting operations performed by the AMF2 in the embodiments of Figures 2 to 10. The processing module 1110 can, for example, be used to perform all operations performed by the AMF2 in the embodiments of Figures 2 to 10 except for the transmitting and receiving operations.

[0469] In some possible implementations, the communication device 1100 can implement the corresponding behaviors and functions of the UDM in the above-described method embodiments. For example, the communication device 1100 can be a UDM, or a component (e.g., a chip or circuit) used in a UDM. The transceiver module 1120 can, for example, be used to perform all receiving or transmitting operations performed by the UDM in the embodiments of Figures 2 to 10. The processing module 1110 can, for example, be used to perform all operations performed by the UDM in the embodiments of Figures 2 to 10 except for the transmitting and receiving operations.

[0470] In some possible implementations, the communication device 1100 can implement the corresponding behaviors and functions of the H-PCF1 in the above-described method embodiments. For example, the communication device 1100 can be the H-PCF1, or it can be a component (e.g., a chip or circuit) used in the H-PCF1. The transceiver module 1120 can, for example, be used to perform all receiving or transmitting operations performed by the H-PCF1 in the embodiments of Figures 2 to 6. The processing module 1110 can, for example, be used to perform all operations performed by the H-PCF1 in the embodiments of Figures 2 to 6 except for the transmitting and receiving operations.

[0471] In some possible implementations, the communication device 1100 can implement the behaviors and functions of the V-PCF1 in the above-described method embodiments. For example, the communication device 1100 can be a V-PCF1, or a component (e.g., a chip or circuit) used in the V-PCF1. The transceiver module 1120 can be used to perform all receiving or transmitting operations performed by the V-PCF1 in the embodiments of Figures 2 to 6. The processing module 1110 can be used to perform all operations performed by the V-PCF1 in the embodiments of Figures 2 to 6 except for the transmitting and receiving operations.

[0472] In some possible implementations, the communication device 1100 can implement the corresponding behaviors and functions of the V-PCF2 in the above-described method embodiments. For example, the communication device 1100 can be a V-PCF2, or a component (e.g., a chip or circuit) used in the V-PCF2. The transceiver module 1120 can, for example, be used to perform all receiving or transmitting operations performed by the V-PCF2 in the embodiments of Figures 5 and 6. The processing module 1110 can, for example, be used to perform all operations performed by the V-PCF2 in the embodiments of Figures 5 and 6 except for the transmitting and receiving operations.

[0473] In some possible implementations, the communication device 1100 can implement the corresponding behaviors and functions of the PCF1 in the above-described method embodiments. For example, the communication device 1100 can be the PCF1, or it can be a component (e.g., a chip or circuit) used in the PCF1. The transceiver module 1120 can, for example, be used to perform all receiving or transmitting operations performed by the PCF1 in the embodiments of Figures 7 to 9. The processing module 1110 can, for example, be used to perform all operations performed by the PCF1 in the embodiments of Figures 7 to 9 except for the transmitting and receiving operations.

[0474] In some possible implementations, the communication device 1100 can implement the corresponding behaviors and functions of the PCF2 in the above-described method embodiments. For example, the communication device 1100 can be the PCF2, or a component (e.g., a chip or circuit) used in the PCF2. The transceiver module 1120 can, for example, be used to perform all receiving or transmitting operations performed by the PCF2 in the embodiments of Figures 7 and 10. The processing module 1110 can, for example, be used to perform all operations performed by the PCF2 in the embodiments of Figures 7 and 10 except for the transmitting and receiving operations.

[0475] FIG12 is a schematic diagram of the structure of another device 120 provided in an embodiment of the present application. The device in FIG12 can be the aforementioned AMF1 or a chip for the aforementioned AMF1, or the aforementioned AMF2 or a chip for the aforementioned AMF2, or the aforementioned UDM or a chip for the aforementioned UDM, or the aforementioned H-PCF1 or a chip for the aforementioned H-PCF1, or the aforementioned V-PCF1 or a chip for the aforementioned V-PCF1, or the aforementioned V-PCF2 or a chip for the aforementioned V-PCF2, or the aforementioned PCF1 or a chip for the aforementioned PCF1, or the aforementioned PCF2 or a chip for the aforementioned PCF2. As shown in FIG12 , the device 120 includes a processing circuit 1210 and a transceiver circuit 1220.

[0476] In some embodiments of the present application, the processing circuit 1210 and the transceiver circuit 1220 may be configured to execute functions or operations performed by the AMF 1. For example, the transceiver circuit 1220 may be configured to execute all receiving or transmitting operations performed by the AMF 1 in the embodiments of Figures 2 to 10. For example, the processing circuit 1210 may be configured to execute all operations performed by the AMF 1 in the embodiments of Figures 2 to 10 except for the transceiver operations.

[0477] In some embodiments of the present application, the processing circuit 1210 and the transceiver circuit 1220 may be configured to execute functions or operations performed by the AMF2. The transceiver circuit 1220, for example, may be configured to execute all receiving or transmitting operations performed by the AMF2 in the embodiments of Figures 2 to 10. The processing circuit 1210, for example, may be configured to execute all operations performed by the AMF2 in the embodiments of Figures 2 to 10 except for the transceiver operations.

[0478] In some embodiments of the present application, the processing circuit 1210 and the transceiver circuit 1220 may be configured to perform functions or operations performed by the UDM. The transceiver circuit 1220 may, for example, be configured to perform all receiving or transmitting operations performed by the UDM in the embodiments of Figures 2 to 10. The processing circuit 1210 may, for example, be configured to perform all operations performed by the UDM in the embodiments of Figures 2 to 10 except for the transceiver operations.

[0479] In some embodiments of the present application, the processing circuit 1210 and the transceiver circuit 1220 may be configured to execute functions or operations performed by the H-PCF 1. The transceiver circuit 1220 may, for example, be configured to execute all receiving or transmitting operations performed by the H-PCF 1 in the embodiments of Figures 2 to 6. The processing circuit 1210 may, for example, be configured to execute all operations performed by the H-PCF 1 in the embodiments of Figures 2 to 6 except for the transceiver operations.

[0480] In some embodiments of the present application, the processing circuit 1210 and the transceiver circuit 1220 may be configured to execute functions or operations performed by the V-PCF 1. The transceiver circuit 1220 may, for example, be configured to execute all receiving or transmitting operations performed by the V-PCF 1 in the embodiments of Figures 2 to 6. The processing circuit 1210 may, for example, be configured to execute all operations performed by the V-PCF 1 in the embodiments of Figures 2 to 6 except for the transceiver operations.

[0481] In some embodiments of the present application, the processing circuit 1210 and the transceiver circuit 1220 may be configured to execute functions or operations performed by the V-PCF2. The transceiver circuit 1220, for example, may be configured to execute all receiving or transmitting operations performed by the V-PCF2 in the embodiments of Figures 5 and 6. The processing circuit 1210, for example, may be configured to execute all operations performed by the V-PCF2 in the embodiments of Figures 5 and 6 except for the transceiver operations.

[0482] In some embodiments of the present application, the processing circuit 1210 and the transceiver circuit 1220 may be configured to execute functions or operations performed by the PCF 1. The transceiver circuit 1220 may, for example, be configured to execute all receiving or transmitting operations performed by the PCF 1 in the embodiments of Figures 7 to 9. The processing circuit 1210 may, for example, be configured to execute all operations performed by the PCF 1 in the embodiments of Figures 7 to 9 except for the transceiver operations.

[0483] In some embodiments of the present application, the processing circuit 1210 and the transceiver circuit 1220 may be configured to execute functions or operations performed by the PCF2. The transceiver circuit 1220 may, for example, be configured to execute all receiving or transmitting operations performed by the PCF2 in the embodiments of Figures 7 and 10. The processing circuit 1210 may, for example, be configured to execute all operations performed by the PCF2 in the embodiments of Figures 7 and 10 except for the transceiver operations.

[0484] In a possible implementation, the transceiver circuit 1220 includes at least one transceiver, and the processing circuit 1210 includes at least one processor, or a circuit in at least one processor for processing or control.

[0485] The transceiver is used to communicate with other devices / apparatuses via a transmission medium. The processor uses the transceiver to transmit and receive data and / or signaling and is used to implement the methods in the above-described method embodiments. The processor can implement the functions of the processing module 1110, and the transceiver can implement the functions of the transceiver module 1120. Optionally, the transceiver may include a radio frequency circuit and an antenna. The radio frequency circuit is primarily used for converting baseband signals into radio frequency signals and processing radio frequency signals. The antenna is primarily used for transmitting and receiving radio frequency signals in the form of electromagnetic waves.

[0486] Optionally, the device 120 may further include at least one memory for storing program instructions and / or data. The memory and the processor are coupled. The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units, or modules, which may be electrical, mechanical, or other forms, and is used for information exchange between the devices, units, or modules. The processor may operate in conjunction with the memory. The processor may execute program instructions stored in the memory. At least one of the at least one memory may be included in the processor.

[0487] The processor can read software programs in the memory, interpret and execute the instructions of the software programs, and process the data of the software programs. When data needs to be sent wirelessly, the processor performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then transmits the radio frequency signal to the outside in the form of electromagnetic waves via the antenna. When data is sent to device 120, the radio frequency circuit receives the radio frequency signal via the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data.

[0488] In another implementation, the RF circuit and antenna may be arranged independently of the processor performing baseband processing. For example, in a distributed scenario, the RF circuit and antenna may be arranged remotely from the device 120 .

[0489] The specific connection medium between the above-mentioned transceiver, processor and memory is not limited in the embodiments of the present application.

[0490] In the embodiments of the present application, the processor may be one of the following devices: a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or all or part of the circuits used for processing functions in the aforementioned devices, which may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0491] In one possible implementation, the processing circuit 1210 includes at least one logic circuit, and the transceiver circuit 1220 includes at least one interface. The processing module 1110 in Figure 11 can be implemented using a logic circuit, and the transceiver module 1120 in Figure 11 can be implemented using an interface. The logic circuit can be a chip, a processing circuit, an integrated circuit, or a system on chip (SoC) chip, and the interface can be a communication interface, an input / output interface, etc. In the embodiment of the present application, the logic circuit and the interface can also be coupled to each other. The embodiment of the present application does not limit the specific connection method of the logic circuit and the interface.

[0492] The present application also provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed on a computer, the computer executes the method of the above embodiment.

[0493] The present application also provides a computer program product, which includes instructions or a computer program. When the instructions or the computer program are run on a computer, the method in the above embodiment is executed.

[0494] The present application also provides a communication system, including the above-mentioned AMF1, the above-mentioned AMF2, a dual-directional device, a UDM, the above-mentioned H-PCF1, and the above-mentioned V-PCF1 and / or the above-mentioned V-PCF2.

[0495] The present application also provides a chip, which includes: a communication interface and a processor; the communication interface is used for sending and receiving signals of the above-mentioned chip; the processor is used to execute computer program instructions so that the communication device including the above-mentioned chip executes the method in the above-mentioned embodiment.

[0496] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0497] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0498] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)). For example, the aforementioned available medium includes, but is not limited to, various media that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0499] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: The method is applied to an access and mobility management function network element, and the method includes: receiving first information from a first network element, the first information including first identification information, the first identification information being used to identify a first home policy control function network element, the first home policy control function network element being a home policy control function network element associated with a first user equipment, the first user equipment being one of a dual-directional device, and the first network element being configured to store an association between the first home policy control function network element and the first user equipment; Determining the first home policy control function network element based on the first information; A first message is sent, where the first message includes the first identification information, and the first message is used to request to establish or modify a policy association of a second user equipment in the dual-directional device, where the second user equipment is associated with the first user equipment.

2. The method according to claim 1, characterized in that The first information further includes first indication information, where the first indication information is used to indicate that the first identification information is used to select the same home policy control function network element for two user equipments in the dual-directional device.

3. The method according to claim 1 or 2, characterized in that The first message also includes an identifier of the first user equipment and an identifier of the second user equipment.

4. The method according to any one of claims 1 to 3, characterized in that The first information further includes second identification information, where the second identification information is used to identify a first visited location policy control function network element, where the first visited location policy control function network element is a visited location policy control function network element associated with the first user equipment. The determining the first home location policy control function network element based on the first information includes: Determining the first home location policy control function network element and the first visited location policy control function network element based on the first information; The sending of the first message includes: The first message is sent to the first visited location policy control function network element, where the first message includes the first identification information.

5. The method according to any one of claims 1 to 3, characterized in that The method further comprises: receiving a registration request sent by the second user equipment when registering in the visited network; In response to the registration request, selecting a second visited location policy control function network element for the second user equipment; The sending of the first message includes: The first message is sent to the second visited location policy control function network element, where the first message includes the first identification information.

6. A communication method, characterized in that: The method comprises: receiving a first message from an access and mobility management function network element, the first message being used to request establishment or modification of a policy association for a second user equipment, where the second user equipment is one of the dual-directional devices, the first message including first identification information, the first identification information being used to identify a first home policy control function network element, the first home policy control function network element being a home policy control function network element associated with the first user equipment, the first user equipment being the other of the dual-directional devices, and the first user equipment and the second user equipment being associated; Obtaining a policy of the first user equipment from the first home policy control function network element; Determine a policy for the second user equipment according to the policy of the first user equipment.

7. The method according to claim 6, characterized in that The method is applied to a policy control function network element for determining an access and mobility AM policy of the first user equipment; determining the policy of the second user equipment based on the policy of the first user equipment includes: Determine the AM policy of the second user equipment according to the AM policy of the first user equipment.

8. The method according to claim 6, characterized in that The obtaining the policy of the first user equipment from the first home policy control function network element includes: Obtaining an AM policy for the first user equipment from the first home policy control function network element; The determining, according to the policy of the first user equipment, the policy of the second user equipment includes: Determine the AM policy of the second user equipment according to the AM policy of the first user equipment.

9. The method according to any one of claims 6 to 8, characterized in that The method further comprises: Send the AM policy of the second user equipment to the first home policy control function network element.

10. The method according to claim 6, characterized in that The method further comprises: Obtaining the AM policy of the first user equipment from a visited location policy control function network element associated with the first user equipment; Determine the AM policy of the second user equipment according to the AM policy of the first user equipment.

11. A communication method, characterized in that: The method is applied to an access and mobility management function network element, and the method includes: receiving first information from a first network element, the first information including first identification information, the first identification information being used to identify a first home policy control function network element, the first home policy control function network element being a home policy control function network element associated with a first user equipment, the first user equipment being one of a dual-directional device, and the first network element being capable of storing and managing an association between the first home policy control function network element and the first user equipment; Determining the first home policy control function network element based on the first information; A second message is sent to the first home location policy control function network element, where the second message is used to request establishment or modification of a policy association for a second user device, where the second user device is another user device in the dual-directional device, and the second user device is associated with the first user device, and the second message includes second identification information and / or third identification information, where the second identification information is used to identify the visited location policy control function network element associated with the first user device, and the third identification information is used to identify the first user device.

12. The method according to claim 11, characterized in that The first information further includes first indication information, where the first indication information is used to indicate that the first identification information is used to select the same home policy control function network element for two user equipments in the dual-directional device.

13. A communication method, characterized in that: The method is applied to a first home policy control function network element, and the method includes: receiving a second message from an access and mobility management function network element, where the second message is used to request establishment or modification of a policy association for a second user equipment, where the second user equipment is one of the dual-directional devices, and the second message includes second identification information and / or third identification information, where the second identification information is used to identify a visited location policy control function network element associated with the first user equipment, and the third identification information is used to identify the first user equipment, where the first user equipment is the other user equipment in the dual-directional devices, and the first user equipment and the second user equipment are associated; Based on the second identification information and / or the third identification information, the access and mobility AM policy of the first user equipment is obtained from the visited location policy control function network element associated with the first user equipment.

14. The method according to claim 13, characterized in that The acquiring, based on the second identification information and / or the third identification information, the access and mobility AM policy of the first user equipment from the visited location policy control function network element associated with the first user equipment includes: Determining, based on the third identification information, a visited location policy control function network element associated with the first user equipment; The AM policy of the first user equipment is obtained from a visited location policy control function network element associated with the first user equipment.

15. A communication method, characterized in that: The method is applied to an access and mobility management function network element, and the method includes: Selecting a first home policy control function network element for a first user equipment, where the first user equipment is one of the dual-directional devices; When the first trigger condition is met, second information is sent to the first network element, where the second information includes first identification information, and the first identification information is used to identify the first home policy control function network element. The first trigger condition includes at least one of the following: learning that the first user device has a dual-directional contract or is authorized for dual-directional, learning that the registration request message of the first user device contains a dual-directional indication and / or dual-directional capability, and learning that the first user device is the main user device among the dual-directional devices.

16. The method according to claim 15, characterized in that The first trigger condition further includes: learning that the first user equipment is registered in a visited network; and the second information further includes identification information of a visited policy control function network element associated with the first user equipment.

17. The method according to claim 15 or 16, characterized in that The second information further includes first indication information, where the first indication information is used to indicate that the first identification information is used to select the same home policy control function network element for two user equipments in the dual-directional device.

18. A communication method, characterized in that: The method is applied to a first network element, and the method includes: receiving second information from a first access and mobility management function network element, where the second information includes first identification information, where the first identification information is used to identify a home policy control function network element associated with a first user equipment, where the first user equipment is one of dual-directional devices, and the first access and mobility management function network element is an access and mobility management function network element of the first user equipment; When the second trigger condition is met, a third message is sent to the second access and mobility management function network element, where the third message includes the first identification information, and the second trigger condition includes at least one of the following: learning that the second user equipment has a dual-directional subscription and the second user equipment is associated with the first user equipment, learning that the second user equipment is a secondary user equipment in the dual-directional device, learning that the network registered by the first user equipment is different from the network registered by the second user equipment, or the type of wireless access technology used by the first user equipment is the same as or different from the type of wireless access technology used by the second user equipment, and the second user equipment and the first user equipment are in the same dual-directional device, wherein the second user equipment is associated with the first user equipment, and the second access and mobility management function network element is the access and mobility management function network element of the second user equipment.

19. The method according to claim 18, characterized in that The second trigger condition further includes: the first user equipment and the second user equipment are registered in the same visited network; and the third message further includes: identification information of a visited policy control function network element associated with the first user equipment.

20. The method according to claim 18 or 19, characterized in that The second information also includes first indication information, where the first indication information is used to indicate that the first identification information is used to select the same home policy control function network element for two user equipments in the dual-directional device. The first response message also includes the first indication information.

21. A communication method, characterized in that: The method is applied to a home policy control function network element associated with a first user equipment, and the method includes: Sending a fourth message to the first visited location policy control function network element, where the fourth message is used to subscribe to the access and mobility AM policy of the first user equipment; receiving an AM policy of the first user equipment sent by the first visited location policy control function network element; The AM policy of the first user equipment is sent to the second visited location policy control function network element, the second visited location policy control function network element is associated with the second user equipment, the second user equipment is another user equipment in the dual-directional device, and the second user equipment is associated with the first user equipment.

22. A communication method, characterized in that: The method is applied to a second access and mobility management function network element, and the method includes: When a third trigger condition is met, a second request message is sent to the first access and mobility management function network element, where the second request message is used to request identification information of a first policy control function network element associated with a first user equipment, where the first user equipment is one of a dual-directional device, and the third trigger condition includes at least one of the following: learning that a second user equipment has a dual-directional subscription and that the second user equipment is associated with the first user equipment, learning that the second user equipment is performing a dual-directional registration, and learning that the second user equipment is a secondary user equipment in the dual-directional device, and the first user equipment and the second user equipment are associated; A second response message is received, where the second response message includes identification information of the first policy control function network element.

23. The method according to claim 22, characterized in that The method further comprises: A second message is sent to the first policy control function network element, where the second message is used to request to establish or modify a policy association of the second user equipment.

24. A communication method, characterized in that: The method is applied to a first access and mobility management function network element, and the method includes: receiving a second request message from a second access and mobility management function network element, where the second request message is used to request identification information of a first policy control function network element associated with a first user equipment, where the first user equipment is one of the dual-directional devices; A second response message is sent to the second access and mobility management function network element, where the second response message includes identification information of the first policy control function network element.

25. The method according to claim 24, characterized in that The method further comprises: A third message is sent to the first policy control function network element, where the third message is used to request establishment of a policy association for the first user equipment.

26. A communication device, characterized in that: The method comprises modules or units for implementing the method according to any one of claims 1 to 25.

27. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, wherein the computer program includes program instructions. When the program instructions are executed, the computer is caused to perform the method according to any one of claims 1 to 25.

28. A communication device, characterized in that: The communication device comprises a processor coupled to a memory, wherein the memory is used to store programs or instructions. When the programs or instructions are executed by the processor, the communication device performs the method according to any one of claims 1 to 25.

29. A chip, characterized in that: include: A communication interface, used for sending and receiving signals from the chip; A processor, configured to execute computer program instructions so that a communication device comprising the chip performs the method according to any one of claims 1 to 25.

30. A computer program product, characterized in that The computer program product comprises a computer program, wherein the computer program comprises program instructions, and when the program instructions are executed, the computer is caused to perform the method according to any one of claims 1 to 25.

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