Communication method, communication device, and communication system

Abstract

The application provides a communication method, a communication device and a communication system. In the method, a first policy control network element determines a mobility management policy according to a state of a session of a terminal or a state of an application, so that the mobility management policy can be accurately determined. Moreover, the first policy control network element only needs to save event identification information and a notification address to a data management network element, so that the state of the session of the terminal or the state of the application of the terminal can be received from a second policy control network element, and the first policy control network element does not need to query address information of the second policy control network element, so that the signaling overhead of the first policy control network element can be reduced.

Description

[0001] This application is a divisional application. The original application has the application number 202111364836.6 and the original application date is November 17, 2021. The entire contents of the original application are incorporated herein by reference.

[0002] This application claims priority to Chinese Patent Application No. 202110875024.1, filed on July 30, 2021, entitled "Communication Method, Communication Apparatus and Communication System", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of wireless communication technology, and in particular to communication methods, communication devices and communication systems. Background Technology

[0004] In 5G systems, when a terminal registers with an Access and Mobility Management (AMF) network element, the AMF network element interacts with the Access and Mobility Management Policy Control (AMPCF) network element to establish an Access and Mobility Policy Association (AMpolicy Association). The AMPCF network element then formulates mobility policies and provides them to the AMF network element for policy execution.

[0005] However, how to accurately determine mobility management strategies is a problem that needs to be solved. Summary of the Invention

[0006] This application provides a communication method, communication device, and communication system for accurately determining mobility management strategies.

[0007] In a first aspect, embodiments of this application provide a communication method, which can be executed by a first policy control network element or a module (such as a chip) applied in the first policy control network element. Taking the execution of the method by the first policy control network element as an example, the first policy control network element sends a request message to a data management network element. The request message contains terminal identification information, event identification information, and a notification address. The event identification information is used to indicate the state of the detected session or the state of the application. The notification address is the address of the first policy control network element used to receive the event notification corresponding to the event identification information. The request message is used to request the data management network element to save the event identification information and the notification address. The first policy control network element receives a notification message from a second policy control network element. The notification message contains the state of the terminal's session or the state of the terminal's application. The state of the terminal's session or the state of the terminal's application is detected based on the event identification information obtained from the data management network element. The first policy control network element determines a mobility management policy based on the state of the terminal's session or the state of the terminal's application. The first policy control network element is used to formulate a mobility management policy, and the second policy control network element is used to formulate a session management policy.

[0008] According to the above scheme, the first policy control network element determines the mobility management policy based on the terminal's session state or application state, enabling precise determination of the mobility management policy. Furthermore, since the first policy control network element only needs to save the event identifier information and notification address to the data management network element to receive the terminal's session state or application state from the second policy control network element, it does not need to query the address information of the second policy control network element, thereby reducing the signaling overhead of the first policy control network element.

[0009] As one possible implementation, when the terminal's session is in session establishment or the terminal's application is in application start, the first policy control network element determines the mobility management policy based on application layer information from the application function network element.

[0010] According to the above scheme, the mobility management strategy can be accurately determined.

[0011] As one possible implementation, the application layer information includes a combination of (data network name (DNN) and single network slice selection assistance information (S-NSSAI)), and the request message also includes the (DNN, S-NSSAI) combination. The second policy control network element corresponds to the (DNN, S-NSSAI) combination.

[0012] According to the above scheme, it is possible to achieve refined management of event identification information based on the combination of (DNN, S-NSSAI).

[0013] As one possible implementation, the request message also includes first indication information, which is used to indicate a notification strategy. The notification strategy is to send the notification message when the first session corresponding to the (DNN, S-NSSAI) combination is established, and / or when the last session corresponding to the (DNN, S-NSSAI) combination is terminated.

[0014] According to the above scheme, the number of notification messages sent can be reduced, thereby reducing signaling overhead.

[0015] As one possible implementation, the mobility management policy includes second indication information, which indicates that the mobility management policy is determined based on the application layer information.

[0016] According to the above scheme, the device receiving the mobility management policy can know that the mobility management policy is determined based on application layer information, which helps to achieve the rational use of the mobility management policy.

[0017] As one possible implementation, the first policy control network element receives a response message from the data management network element. The response message includes first identification information, which is the identification information of the event identification information and the notification address. The first identification information is used to modify or delete the event identification information and / or the notification address.

[0018] According to this scheme, it is possible to quickly modify or delete event identification information and notification addresses stored in data management network elements.

[0019] As one possible implementation method, the first policy control network element sends the mobility management policy to the application function network element.

[0020] As one possible implementation, the first policy control network element receives third indication information from a mobility management network element, the third indication information being used to indicate that the mobility management policy used by the terminal is determined based on application layer information; the first policy control network element determines the mobility management policy with a delay based on the third indication information; wherein, the first policy control network element is a policy control network element that provides services to the terminal after the terminal moves.

[0021] This scheme will help to accurately determine mobility management strategies.

[0022] Secondly, embodiments of this application provide a communication method, which can be executed by a second policy control network element or a module (such as a chip) applied in the second policy control network element. Taking the execution of the method by the second policy control network element as an example, the second policy control network element receives event identification information and a notification address from a data management network element. The event identification information is used to indicate the state of the detected session or the state of the application. The notification address is the address of a first policy control network element used to receive event notifications corresponding to the event identification information. The second policy control network element detects the state of the terminal's session or the state of the terminal's application based on the event identification information. The second policy control network element sends a notification message to the first policy control network element based on the notification address. The notification message contains the state of the terminal's session or the state of the terminal's application. The first policy control network element is used to formulate mobility management policies, and the second policy control network element is used to formulate session management policies.

[0023] According to the above scheme, the session state or application state of the terminal can be used by the first policy control network element to determine the mobility management policy, enabling accurate determination of the mobility management policy. Furthermore, the second policy control network element can obtain the event identifier information of the events to be detected from the data management network element, as well as the address of the first policy control network element receiving event notifications, thereby enabling rapid notification of event information to the first policy control network element.

[0024] As one possible implementation of the first or second aspect, the notification message also includes at least one of the terminal's session identifier, the terminal's address, or the identifier of the second policy control network element.

[0025] As one possible implementation, the second policy control network element sends a query request message to the data management network element, the query request message being used to request a query of the terminal's subscription data; the second policy control network element receives a query response message from the data management network element, the query response message including the terminal's subscription data, the subscription data including the event identification information and the notification address.

[0026] According to the above scheme, the second policy control network element can obtain event identification information and notification address from the data management network element in real time through query requests, which helps the second policy control network element to obtain event identification information and notification address in a timely manner.

[0027] As one possible implementation, the query request message also includes a (DNN, S-NSSAI) combination, the second policy control network element corresponds to the (DNN, S-NSSAI) combination, and the query request message is used to request the query of the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination.

[0028] As one possible implementation, the second policy control network element sends a subscription data request message to the data management network element. The subscription data request message is used to request notification of changes to the terminal's subscription data. The second policy control network element receives a notification message from the data management network element. The notification message includes the terminal's changed subscription data, which contains the event identifier information and the notification address.

[0029] According to the above scheme, the second policy control network element does not need to frequently send query request messages to the data management network element to request the terminal's subscription data. Instead, by sending a subscription data subscription request message, the data management network element can then proactively send the terminal's subscription data to the second policy control network element, thus reducing signaling overhead.

[0030] As one possible implementation, the subscription data request message also includes a (DNN, S-NSSAI) combination, the second policy control network element corresponds to the (DNN, S-NSSAI) combination, and the subscription data request is used to request the terminal to receive notification of changes to the subscription data corresponding to the (DNN, S-NSSAI) combination.

[0031] Thirdly, embodiments of this application provide a communication method, which can be executed by a data management network element or a module (such as a chip) applied in the data management network element. Taking the execution of the method by a data management network element as an example, the data management network element receives a request message from a first policy control network element. The request message contains terminal identification information, event identification information, and a notification address. The event identification information is used to indicate the state of the detection session or the state of the application. The notification address is the address of the first policy control network element used to receive the event notification corresponding to the event identification information. The request message is used to request the data management network element to save the event identification information and the notification address. The data management network element sends the event identification information and the notification address to a second policy control network element. The first policy control network element is used to formulate a mobility management policy, and the second policy control network element is used to formulate a session management policy.

[0032] According to the above scheme, the data management network element, as an intermediate node connecting the first policy control network element and the second policy control network element, can receive terminal identification information, event identification information, and notification address from the first policy control network element. It can then transmit the event identification information and notification address to the second policy control network element so that the second policy control network element can detect the event based on the event identification information and send the detected event to the first policy control network element. This eliminates the need for the first policy control network element to search for the address of the second policy control network element, thereby reducing unnecessary signaling overhead.

[0033] As one possible implementation, the data management network element receives a query request message from the second policy control network element, the query request message being used to request a query of the terminal's subscription data; the data management network element sends a query response message to the second policy control network element, the query response message including the terminal's subscription data, the subscription data including the event identifier information and the notification address.

[0034] According to the above scheme, the data management network element can send event identification information and notification address to the second policy control network element in real time based on the query request sent by the second policy control network element, which helps the second policy control network element to obtain event identification information and notification address in a timely manner.

[0035] As one possible implementation, the query request message also includes a (DNN, S-NSSAI) combination, the second policy control network element corresponds to the (DNN, S-NSSAI) combination, and the query request message is used to request the query of the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination.

[0036] As one possible implementation, the data management network element receives a subscription data request message from the second policy control network element, the subscription data request message being used to request notification of changes to the terminal's subscription data; the data management network element sends a notification message to the second policy control network element, the notification message including the terminal's changed subscription data, the changed subscription data including the event identifier information and the notification address.

[0037] According to the above scheme, the second policy control network element does not need to frequently send query request messages to the data management network element to request the terminal's subscription data. Instead, by sending a subscription data subscription request message, the data management network element can then proactively send the terminal's subscription data to the second policy control network element, thus reducing signaling overhead.

[0038] As one possible implementation, the subscription data request message also includes a (DNN, S-NSSAI) combination, the second policy control network element corresponds to the (DNN, S-NSSAI) combination, and the subscription data request is used to request the terminal to receive notification of changes to the subscription data corresponding to the (DNN, S-NSSAI) combination.

[0039] As one possible implementation method, the data management network element sends a response message to the first policy control network element. The response message includes first identification information, which is the identification information of the event identification information and the notification address. The first identification information is used to modify or delete the event identification information and / or the notification address.

[0040] According to this scheme, it is possible to quickly modify or delete event identification information and notification addresses stored in data management network elements.

[0041] Fourthly, embodiments of this application provide a communication method, which can be executed by a first policy control network element or a module (such as a chip) applied in the first policy control network element. Taking the execution of the method by the first policy control network element as an example, the first policy control network element sends a request message to a data management network element. The request message contains first identification information and a first notification address. The first identification information is event identification information and the identification information of a second notification address stored by the data management network element. The event identification information is used to indicate the state of the detection session or the state of the application. The first notification address is the address of the first policy control network element used to receive the event notification corresponding to the event identification information. The second notification address is the address of a third policy control network element used to receive the event notification corresponding to the event identification information. The request message is used to request the data management network element to update the second notification address to the first notification address. The first policy control network element receives... The first policy control network element receives a notification message from the second policy control network element. This notification message contains the state of the terminal's session or the state of the terminal's application. The state of the terminal's session or the state of the terminal's application is detected based on the event identification information obtained from the data management network element. The first policy control network element determines a mobility management policy based on the state of the terminal's session or the state of the terminal's application. The first policy control network element and the third policy control network element are used to formulate mobility management policies. The second policy control network element is used to formulate session management policies. The first policy control network element is the policy control network element that provides services to the terminal after the terminal moves, and the third policy control network element is the policy control network element that provides services to the terminal before the terminal moves.

[0042] According to the above scheme, the first policy control network element determines the mobility management policy based on the terminal's session state or application state, enabling precise determination of the mobility management policy. Furthermore, since the first policy control network element modifies the second event notification address stored by the data management network element using the first identification information, the second policy control network element can subsequently obtain the event identification information and the updated first notification address from the data management network element. Then, the first policy control network element can receive the terminal's session state or application state from the second policy control network element without needing to query the address information of the second policy control network element, thereby reducing the signaling overhead of the first policy control network element.

[0043] As one possible implementation, the notification message may also include at least one of the terminal's session identifier, the terminal's address, or the identifier of the second policy control network element.

[0044] Fifthly, embodiments of this application provide a communication method, which can be executed by a first policy control network element or a module (such as a chip) applied in the first policy control network element. Taking the execution of the method by the first policy control network element as an example, the first policy control network element sends a first request message to a mobility management network element. The first request message contains event identification information, which is used to indicate the state of the terminal's session or the state of the terminal's application. The first request message is used to request an event notification corresponding to the event identification information. The first policy control network element receives a first notification message from the mobility management network element or the session management network element corresponding to the session. The first notification message contains the state of the terminal's session or the state of the terminal's application. The state of the terminal's session or the state of the terminal's application is detected based on the event identification information. The first policy control network element determines a mobility management policy based on the state of the terminal's session or the state of the terminal's application. The first policy control network element is used to formulate the mobility management policy.

[0045] According to the above scheme, the first policy control network element determines the mobility management policy based on the terminal's session state or application state, which can achieve accurate determination of the mobility management policy. Furthermore, since the first policy control network element only needs to send event identification information to the mobility management network element to quickly receive the terminal's session state or application state, it helps to improve the speed of determining the mobility management policy.

[0046] As one possible implementation, when the session is in session establishment or the application is in application start, the first policy control network element determines the mobility management policy based on the application layer information from the application function network element.

[0047] According to the above scheme, the mobility management strategy can be accurately determined.

[0048] As one possible implementation, the first request message also includes the (DNN, S-NSSAI) combination, which is determined based on application layer information from the application function network element.

[0049] As one possible implementation, the state of the session includes the establishment of the session corresponding to the (DNN, S-NSSAI) combination or the termination of the session corresponding to the (DNN, S-NSSAI) combination.

[0050] As one possible implementation, the first request message also includes first indication information, which is used to indicate a notification strategy. The notification strategy is to send the first notification message when the first session corresponding to the (DNN, S-NSSAI) combination is established, and / or when the last session corresponding to the (DNN, S-NSSAI) combination is terminated.

[0051] According to the above scheme, the number of notification messages sent can be reduced, thereby reducing signaling overhead.

[0052] As one possible implementation, the state of the session is either the establishment of the first session corresponding to the (DNN, S-NSSAI) combination, or the termination of the last session corresponding to the (DNN, S-NSSAI) combination.

[0053] As one possible implementation, the mobility management policy includes second indication information, which indicates that the mobility management policy is determined based on application layer information.

[0054] According to the above scheme, the device receiving the mobility management policy can know that the mobility management policy is determined based on application layer information, which helps to achieve the rational use of the mobility management policy.

[0055] As one possible implementation method, the first policy control network element sends the mobility management policy to the application function network element.

[0056] As one possible implementation, when the terminal's session is in session establishment or the application is in application start, the first policy control network element determines the mobility management policy based on application layer information from the application function network element.

[0057] As one possible implementation, the state of the session is used to indicate the establishment of the first session corresponding to the (DNN, S-NSSAI) combination or the termination of the last session corresponding to the (DNN, S-NSSAI) combination.

[0058] Sixthly, embodiments of this application provide a communication method, which can be executed by a session management network element or a module (such as a chip) applied in a session management network element. Taking the execution of the method by a session management network element as an example, the session management network element receives a second request message from a mobility management network element. The second request message contains event identification information, which is used to indicate the state of the terminal's session or the state of the terminal's application. The second request message is used to request an event notification corresponding to the event identification information. The session management network element detects the state of the terminal's session or the state of the terminal's application based on the event identification information. The session management network element sends a notification message to the mobility management network element or a first policy control network element corresponding to the terminal. The notification message contains the state of the terminal's session or the state of the terminal's application. The first policy control network element is a policy control network element used to formulate mobility management policies.

[0059] According to the above scheme, the state of the terminal's session or the state of the application can be used by the first policy control network element to determine the mobility management policy, which can achieve accurate determination of the mobility management policy.

[0060] As one possible implementation, the second request message also includes a (DNN, S-NSSAI) combination, which is used to request the state of the session or application of the terminal corresponding to the (DNN, S-NSSAI) combination.

[0061] As one possible implementation, the second request message also includes first indication information, which is used to indicate a notification strategy. The notification strategy is to send the notification message when the first session corresponding to the (DNN, S-NSSAI) combination is established, and / or when the last session corresponding to the (DNN, S-NSSAI) combination is terminated.

[0062] According to the above scheme, the number of notification messages sent can be reduced, thereby reducing signaling overhead.

[0063] Seventhly, embodiments of this application provide a communication method, which can be executed by a mobility management network element (MLE) or a module (such as a chip) applied in a MLE. Taking the execution of this method by a MLE as an example, the MLE receives a first request message from a first policy control network element. The first request message contains event identification information, which is used to indicate the state of the terminal's session or the state of the terminal's application. The first request message is used to request an event notification corresponding to the event identification information. After detecting the event corresponding to the event identification information, the MLE sends a first notification message to the first policy control network element. The first notification message contains the state of the terminal's session or the state of the terminal's application, which is obtained based on the event identification information. The first policy control network element is used to formulate mobility management policies.

[0064] According to the above scheme, the state of the terminal's session or the state of the application can be used by the first policy control network element to determine the mobility management policy, which can achieve accurate determination of the mobility management policy.

[0065] As a possible implementation of the fifth or seventh aspect, the first request message further includes a (DNN, S-NSSAI) combination, which is used to request the state of the session or application of the terminal corresponding to the (DNN, S-NSSAI) combination.

[0066] According to the above scheme, it is possible to achieve refined management of event identification information based on the combination of (DNN, S-NSSAI).

[0067] As one possible implementation, after detecting that a session corresponding to the (DNN, S-NSSAI) combination has been established for the terminal, the mobility management network element sends the first notification message to the first policy control network element. The first notification message contains the status of the session, which is that the session has been established.

[0068] As one possible implementation, after detecting the termination of the session corresponding to the (DNN, S-NSSAI) combination of the terminal, the mobility management network element sends the first notification message to the first policy control network element. The first notification message contains the status of the session, which is that the session has been terminated.

[0069] As one possible implementation, the first request message also includes first indication information, which is used to indicate a notification strategy. The notification strategy is to send the first notification message when the first session corresponding to the (DNN, S-NSSAI) combination is established, and / or when the last session corresponding to the (DNN, S-NSSAI) combination is terminated.

[0070] As one possible implementation, the state of the session is either the establishment of the first session corresponding to the (DNN, S-NSSAI) combination, or the termination of the last session corresponding to the (DNN, S-NSSAI) combination.

[0071] As one possible implementation, after the mobility management network element detects the establishment of the first session corresponding to the (DNN, S-NSSAI) combination of the terminal, it sends the first notification message to the first policy control network element. The first notification message contains the status of the session, which is that the session is established.

[0072] As one possible implementation, after detecting the termination of the last session of the terminal corresponding to the (DNN, S-NSSAI) combination, the mobility management network element sends the first notification message to the first policy control network element. The first notification message contains the status of the session, which is session termination.

[0073] As one possible implementation, the mobility management network element sends a second request message to the session management network element, the second request message containing the event identification information, the second request message being used to request the event notification corresponding to the event identification information; the mobility management network element receives a second notification message from the session management network element, the second notification message containing the application status of the terminal or the session status of the terminal; the mobility management network element sends the first notification message to the first policy control network element.

[0074] As one possible implementation of any of the first to seventh aspects, the event identification information is determined based on application layer information from the application function network element.

[0075] Eighthly, embodiments of this application provide a communication device, which may be a first policy control network element or a chip for the first policy control network element. The device has the function of implementing any of the methods described in the first, fourth, or fifth aspects. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described functions.

[0076] Ninthly, embodiments of this application provide a communication device, which may be a second policy control network element or a chip for the second policy control network element. The device has the function of implementing any of the implementation methods of the second aspect described above. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described functions.

[0077] Tenthly, embodiments of this application provide a communication device, which may be a data management network element or a chip for a data management network element. The device has the function of implementing any of the implementation methods of the third aspect described above. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described functions.

[0078] Eleventhly, embodiments of this application provide a communication device, which may be a session management network element or a chip for a session management network element. This device has the function of implementing any of the implementation methods of the sixth aspect described above. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described functions.

[0079] In a twelfth aspect, embodiments of this application provide a communication device, which may be a mobility management network element or a chip for a mobility management network element. The device has the function of implementing any of the methods described in the seventh aspect above. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described functions.

[0080] In a thirteenth aspect, embodiments of this application provide a communication device, including a processor and a memory; the memory is used to store computer instructions, and when the device is running, the processor executes the computer instructions stored in the memory to cause the device to perform any of the implementation methods in the first to seventh aspects described above.

[0081] In a fourteenth aspect, embodiments of this application provide a communication apparatus including units or means for performing various steps of any of the implementation methods in the first to seventh aspects described above.

[0082] In a fifteenth aspect, embodiments of this application provide a communication device, including a processor and an interface circuit. The processor is configured to communicate with other devices via the interface circuit and execute any of the implementation methods described in the first to seventh aspects. The processor may include one or more devices.

[0083] In a sixteenth aspect, embodiments of this application provide a communication device including a processor coupled to a memory, the processor being configured to invoke a program stored in the memory to execute any of the implementation methods described in the first to seventh aspects. The memory may be located within or outside the device. Furthermore, the processor may be one or more.

[0084] In a seventeenth aspect, embodiments of this application also provide a computer-readable storage medium storing instructions that, when executed on a communication device, cause any of the implementation methods of the first to seventh aspects to be performed.

[0085] In an eighteenth aspect, embodiments of this application also provide a computer program product, which includes a computer program or instructions that, when executed by a communication device, cause any of the implementation methods in the first to seventh aspects to be performed.

[0086] In a nineteenth aspect, embodiments of this application also provide a chip system, including: a processor for executing any of the implementation methods in the first to seventh aspects described above.

[0087] In a twentieth aspect, embodiments of this application also provide a communication system, which includes a first policy control network element for performing any implementation method of the first aspect described above and a second policy control network element for sending notification messages to the first policy control network element.

[0088] As one possible implementation, the second strategy control network element is also used to execute any implementation method of the second aspect described above.

[0089] As one possible implementation, the communication system also includes a data management network element for performing any implementation method of the third aspect described above.

[0090] In a twentieth aspect, embodiments of this application also provide a communication system, which includes a first policy control network element for performing any implementation method of the fourth aspect described above and a second policy control network element for sending notification messages to the first policy control network element.

[0091] As one possible implementation, the second strategy control network element is also used to execute any implementation method of the second aspect described above.

[0092] As one possible implementation, the communication system also includes a data management network element for performing any implementation method of the third aspect described above.

[0093] In a twentieth aspect, embodiments of this application also provide a communication system, which includes a first policy control network element for performing any implementation method of the fifth aspect described above and a mobility management network element for receiving a first request message from the first policy control network element.

[0094] As one possible implementation, the mobility management network element can also be used to execute any implementation method of the seventh aspect described above.

[0095] As one possible implementation, the communication system also includes a session management network element for performing any implementation of the sixth aspect described above. Attached Figure Description

[0096] Figure 1(a) is a schematic diagram of a communication system provided in an embodiment of this application; Figure 1(b) is a schematic diagram of another communication system provided in an embodiment of this application; Figure 2(a) is a schematic diagram of a 5G network architecture based on a service-oriented architecture; Figure 2(b) is a schematic diagram of a 5G network architecture based on a point-to-point interface; Figure 3 This is a schematic diagram illustrating the process of generating and using AM strategies provided in the embodiments of this application; Figure 4 This is a schematic diagram illustrating the process of generating and using AM strategies provided in the embodiments of this application; Figure 5(a) is a flowchart illustrating a communication method provided in an embodiment of this application; Figure 5(b) is a flowchart illustrating a communication method provided in an embodiment of this application; Figure 5(c) is a flowchart illustrating a communication method provided in an embodiment of this application; Figure 6 A flowchart illustrating a communication method provided in an embodiment of this application; Figure 7 A flowchart illustrating a communication method provided in an embodiment of this application; Figure 8 A flowchart illustrating a communication method provided in an embodiment of this application; Figure 9 A flowchart illustrating a communication method provided in an embodiment of this application; Figure 10 A flowchart illustrating a communication method provided in an embodiment of this application; Figure 10 (a) A flowchart illustrating a communication method provided in an embodiment of this application; Figure 11 A schematic diagram of a communication device provided in an embodiment of this application; Figure 12 This is a schematic diagram of a communication device provided in an embodiment of this application. Detailed Implementation

[0097] To achieve accurate determination of AM strategy, as shown in Figure 1(a), this application provides a communication system, which includes a first strategy control network element and a second strategy control network element, and optionally, a data management network element.

[0098] In the first embodiment: A first policy control network element is used to send a request message to a data management network element. This request message includes terminal identification information, event identification information, and a notification address. The event identification information indicates the state of the detected session or application. The notification address is the address of the first policy control network element used to receive event notifications corresponding to the event identification information. The request message requests the data management network element to save the event identification information and the notification address. The first policy control network element also receives a notification message from a second policy control network element. This notification message includes the state of the terminal's session or the state of the terminal's application. The state of the terminal's session or the state of the terminal's application is detected based on the event identification information obtained from the data management network element. The first policy control network element determines a mobility management policy based on the state of the terminal's session or the state of the terminal's application. A second policy control network element is used to send the notification message to the first policy control network element. The first policy control network element is used to formulate a mobility management policy, and the second policy control network element is used to formulate a session management policy.

[0099] As one possible implementation, the second policy control network element is further configured to receive the event identifier information and the notification address from the data management network element; and to detect the session status or application status of the terminal based on the event identifier information. The second policy control network element is also configured to send a notification message to the first policy control network element based on the notification address.

[0100] As one possible implementation, the data management network element is used to receive the request message from the first policy control network element, and to send the event identification information and the notification address to the second policy control network element.

[0101] As one possible implementation, the first policy control network element is configured to receive a response message from the data management network element. The response message includes first identification information, which is the identification information of the event identification information and the notification address. This first identification information is used to modify or delete the event identification information and / or the notification address. The data management network element is configured to send the response message to the first policy control network element.

[0102] As one possible implementation, the second policy control network element is configured to send a query request message to the data management network element, the query request message requesting a query of the terminal's subscription data; and to receive a query response message from the data management network element, the query response message including the terminal's subscription data, which includes the event identifier information and the notification address. The data management network element is configured to receive the query request message from the second policy control network element and to send the query response message to the second policy control network element.

[0103] As one possible implementation, the second policy control network element is configured to send a subscription data request message to the data management network element, the subscription data request message being used to request notification of a change in the terminal's subscription data; and to receive a notification message from the data management network element, the notification message including the terminal's changed subscription data, the changed subscription data containing the event identifier information and the notification address. The data management network element is configured to receive the subscription data request message from the second policy control network element; and to send the notification message to the second policy control network element.

[0104] In the second embodiment: A first policy control network element is configured to send a request message to a data management network element. This request message includes first identification information and a first notification address. The first identification information is an event identification information and a second notification address stored by the data management network element. The event identification information indicates the state of the detected session or application. The first notification address is the address of the first policy control network element used to receive event notifications corresponding to the event identification information. The second notification address is the address of a third policy control network element used to receive event notifications corresponding to the event identification information. The request message requests the data management network element to update the second notification address to the first notification address. The first policy control network element also receives a notification message from a second policy control network element. This notification message contains the state of the terminal's session or the state of the terminal's application, which is detected based on the event identification information obtained from the data management network element. Finally, the second policy control network element determines a mobility management policy based on the state of the terminal's session or the state of the terminal's application. The second policy control network element sends this notification message to the first policy control network element. The first policy control network element and the third policy control network element are used to formulate mobility management policies, the second policy control network element is used to formulate session management policies, the first policy control network element is the policy control network element that provides services to the terminal after the terminal moves, and the third policy control network element is the policy control network element that provides services to the terminal before the terminal moves.

[0105] As one possible implementation, the second policy control network element is further configured to receive the event identification information and the first notification address from the data management network element; detect the state of the terminal's session or the state of the terminal's application based on the event identification information; and send a notification message to the first policy control network element based on the first notification address.

[0106] As one possible implementation, the data management network element is used to receive the request message from the first policy control network element, and to send the event identification information and the first notification address to the second policy control network element.

[0107] Based on the first or second embodiment described above: As one possible implementation, when the terminal's session state is session established or the terminal's application state is application started, the first policy control network element is also used to determine the mobility management policy based on application layer information from the application function network element.

[0108] As one possible implementation, the first policy control network element is used to send the mobility management policy to the application function network element.

[0109] As one possible implementation, the first policy control network element is configured to receive third indication information from a mobility management network element, the third indication information being used to indicate that the mobility management policy used by the terminal is determined based on application layer information; and to determine the mobility management policy with a delay based on the third indication information; wherein, the first policy control network element is a policy control network element that provides services to the terminal after the terminal moves.

[0110] The system shown in Figure 1(a) can be used in the 5G network architecture shown in Figure 2(a) or Figure 2(b). Of course, it can also be used in future network architectures, such as the 6th generation (6G) network architecture. This application does not limit it.

[0111] To achieve accurate determination of AM policy, as shown in Figure 1(b), this application provides a communication system, which includes a first policy control network element and a mobility management network element, and optionally, a session management network element.

[0112] A first policy control network element is configured to send a first request message to a mobility management network element. The first request message includes event identification information, which indicates the state of the terminal's session or the state of the terminal's application. The first request message requests an event notification corresponding to the event identification information. The first policy control network element receives a notification message from the mobility management network element or the session management network element corresponding to the session. This notification message includes the state of the terminal's session or the state of the terminal's application, which is detected based on the event identification information. The first policy control network element determines a mobility management policy based on the state of the terminal's session or the state of the terminal's application. The mobility management network element receives the first request message.

[0113] As one possible implementation, the mobility management network element is used to send an event notification to the first policy control network element after detecting an event corresponding to the event identification information; wherein, the first policy control network element is used to formulate mobility management policies.

[0114] As one possible implementation, when the session is in session establishment or the application is in application start, the first policy control network element is used to determine the mobility management policy based on the application layer information from the application function network element.

[0115] As one possible implementation, the mobility management network element is used to send the status of the session to the first policy control network element after detecting that the session corresponding to the (DNN, S-NSSAI) combination of the terminal has been established, and the status of the session is "session established".

[0116] As one possible implementation, the first policy control network element is used to send the mobility management policy to the application function network element.

[0117] As one possible implementation, the mobility management network element is configured to send a second request message to a session management network element, the second request message containing the event identification information, the second request message being used to request an event notification corresponding to the event identification information; receive a notification message from the session management network element, the notification message containing the application status of the terminal or the session status of the terminal; and send the application status of the terminal or the session status of the terminal to the first policy control network element.

[0118] As one possible implementation, the session management network element is configured to receive the second request message from the mobility management network element; detect the session status of the terminal or the application status of the terminal based on the event identification information; and send the notification message to the mobility management network element or the first policy control network element corresponding to the terminal.

[0119] The system shown in Figure 1(b) can be used in the 5G network architecture shown in Figure 2(a) or Figure 2(b). Of course, it can also be used in future network architectures, such as 6G network architecture. This application does not limit it.

[0120] Figure 2(a) is a schematic diagram of a 5G network architecture based on a service-oriented architecture. The 5G network architecture shown in Figure 2(a) may include a data network (DN) and a carrier network. The functions of some of these network elements are briefly described below.

[0121] The operator network may include one or more of the following network elements: Authentication Server Function (AUSF) network element (not shown in the figure), Unified Data Management (UDM) network element, Unified Data Repository (UDR) network element, Network Repository Function (NRF) network element (not shown in the figure), Network Exposure Function (NEF) network element (not shown in the figure), Application Function (AF) network element, Policy Control Function (PCF) network element, AMF network element, Session Management Function (SMF) network element, User Plane Function (UPF) network element, Binding Support Function (BSF) network element (not shown in the figure), Radio Access Network (RAN) equipment, etc. In the above operator network, network elements or equipment other than RAN equipment can be referred to as core network elements or core network equipment.

[0122] Wireless access network equipment can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB) in a 5G mobile communication system, a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access node in a wireless fidelity (WiFi) system; it can also be a module or unit that performs some of the functions of a base station, for example, a central unit (CU) or a distributed unit (DU). Wireless access network equipment can be a macro base station, a micro base station, an indoor station, a relay node, or a donor node, etc. The embodiments of this application do not limit the specific technology or equipment form used in the wireless access network equipment. For ease of explanation, a base station is used as an example of a wireless access network equipment in the embodiments of this application.

[0123] Terminals communicating with the RAN can also be called terminal equipment, user equipment (terminal), mobile station, mobile terminal, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc. The embodiments of this application do not limit the specific technology or device form used in the terminal.

[0124] Base stations and terminals can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed in the air on aircraft, balloons, and artificial satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminals.

[0125] The AMF (Automatic Mobility Management) network element includes functions such as mobility management and access authentication / authorization. In addition, it is responsible for transmitting user policies between the terminal and the PCF (Programmable Default Function).

[0126] The SMF network element includes functions such as session management, execution of control policies issued by the PCF, selection of the UPF, and allocation of Internet Protocol (IP) addresses for terminals.

[0127] UPF network elements, as the interface between the network and the data network, include functions such as user plane data forwarding, session / flow-level billing statistics, and bandwidth limiting.

[0128] UDM network elements include functions such as managing contracted data and authorizing user access.

[0129] UDR includes functions for storing and retrieving data of various types, such as contract data, policy data, and application data.

[0130] NEF network elements are used to support the opening of capabilities and events.

[0131] An AF (Application Provider) element conveys the application's requests to the network, such as QoS requirements or user state event subscriptions. AFs can be third-party functional entities or application services deployed by operators, such as the IP Multimedia Subsystem (IMS) voice call service.

[0132] PCF network elements include policy control functions such as billing at the session and service flow levels, QoS bandwidth guarantee and mobility management, and terminal policy decision-making. PCF network elements include AM PCF network elements and session management PCF (SM PCF) network elements. AM PCF network elements can provide mobility management policies, while SM PCF network elements can provide session management policies.

[0133] NRF network elements can be used to provide network element discovery functionality, 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, updates, deregistration, and network element status subscription and push.

[0134] The BSF network element can provide functions such as BSF service registration / deregistration / update, NRF connection detection, session binding information creation, UE information acquisition, and session binding information query for duplicate IP addresses.

[0135] The AUSF network element is responsible for authenticating users to determine whether to allow users or devices to access the network.

[0136] A Domain Provider (DN) is a network located outside the carrier's network. A carrier's network can connect to multiple DNs, and various services can be deployed on a DN, providing data and / or voice services to terminals. For example, a DN might be the private network of a smart factory. Sensors installed in the workshop can act as terminals, and a control server for these sensors is deployed within the DN. The control server provides services to the sensors. Sensors can communicate with the control server, receive instructions from it, and transmit the collected sensor data back to the control server accordingly. Another example is a DN serving as an internal office network for a company. Employees' mobile phones or computers can act as terminals, accessing information and data resources on the company's internal office network.

[0137] In Figure 2(a), Npcf, Nufr, Nudm, Naf, Namf, and Nsmf are the service interfaces provided by PCF, UDR, UDM, AF, AMF, and SMF, respectively, used to call the corresponding service operations. N1, N2, N3, N4, and N6 are interface sequence numbers. The meanings of these interface sequence numbers can be found in the definitions in the 3rd generation partnership project (3GPP) standard protocol, and are not limited here.

[0138] Figure 2(b) is a schematic diagram of a 5G network architecture based on point-to-point interfaces. The functions of the network elements can be referred to the corresponding functions of the network elements in Figure 2(a), and will not be repeated here. The main difference between Figure 2(b) and Figure 2(a) is that the interfaces between the control plane network elements in Figure 2(a) are service-oriented interfaces, while the interfaces between the control plane network elements in Figure 2(b) are point-to-point interfaces.

[0139] In the architecture shown in Figure 2(b), the interface names and functions between the various network elements are as follows: 1) N1: The interface between AMF and the terminal, which can be used to transmit QoS control rules to the terminal.

[0140] 2) N2: The interface between AMF and RAN, which can be used to transmit radio bearer control information from the core network side to the RAN.

[0141] 3) N3: The interface between RAN and UPF, mainly used to transmit uplink and downlink user plane data between RAN and UPF.

[0142] 4) N4: The interface between SMF and UPF, which can be used to transmit information between the control plane and the user plane, including the distribution of forwarding rules, QoS control rules, traffic statistics rules, etc. from the control plane to the user plane, as well as the reporting of information from the user plane.

[0143] 5) N5: The interface between AF and PCF, which can be used for application service request distribution and network event reporting.

[0144] 6) N6: The interface between UPF and DN, used to transmit uplink and downlink user data streams between UPF and DN.

[0145] 7) N7: The interface between PCF and SMF, which can be used to issue protocol data unit (PDU) session granularity and business data stream granularity control strategies.

[0146] 8) N8: The interface between AMF and UDM, which can be used by AMF to obtain access and mobility management related subscription data and authentication data from UDM, as well as by AMF to register terminal current mobility management related information with UDM.

[0147] 9) N9: User plane interface between UPFs, used to transmit uplink and downlink user data streams between UPFs.

[0148] 10) N10: The interface between SMF and UDM, which can be used by SMF to obtain session management-related subscription data from UDM, and by SMF to register terminal current session-related information with UDM.

[0149] 11) N11: The interface between SMF and AMF, which can be used to transmit PDU session tunnel information between RAN and UPF, transmit control messages sent to the terminal, and transmit radio resource control information sent to RAN, etc.

[0150] 12) N15: The interface between PCF and AMF, which can be used to issue terminal policies and access control related policies.

[0151] 13) N35: The interface between UDM and UDR, which can be used by UDM to obtain user subscription data information from UDR.

[0152] 14) N36: The interface between PCF and UDR, which can be used by PCF to obtain policy-related contract data and application data related information from UDR.

[0153] It is understood that the aforementioned network element or function can be a network component in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the aforementioned network element or function can be implemented by one device, multiple devices working together, or a functional module within a single device; this application embodiment does not specifically limit this.

[0154] The data management network element, mobility management network element, session management network element, user plane network element, policy control network element, and application function network element in this application can be UDR, AMF, SMF, UPF, PCF, and AF as shown in Figure 2(a) or Figure 2(b), or they can be network elements in future communications such as 6G networks that have the functions of the aforementioned UDR, AMF, SMF, UPF, PCF, and AF. This application does not limit them. In the embodiments of this application, UDR, AMF, SMF, UPF, PCF, and AF are used as examples of data management network element, mobility management network element, session management network element, user plane network element, policy control network element, and application function network element, respectively. Furthermore, PCF includes AM PCF and SM PCF.

[0155] To achieve accurate determination of the AM strategy, one approach is for the AM PCF to determine the AM strategy based on application layer information provided by the AF. The following section will combine... Figure 3 and Figure 4 It provides a method for AM PCF to determine AM strategy and issue AM strategy.

[0156] Figure 3 This is a schematic diagram illustrating the process of AM policy generation and usage provided in an embodiment of this application. This embodiment is an example for a single terminal.

[0157] Step 301: The terminal registers with the network.

[0158] The terminal registers with the network through the AMF, and the AMF interacts with the UDM to obtain the terminal's subscription data from the UDM. This subscription data includes the subscribed service area restrictions and the subscribed radio access technology (RAT) / frequency selection priority (RFSP).

[0159] Among them, the service area restriction information is used to indicate the areas where terminal access is allowed or not allowed, and RFSP is used by radio access network equipment to determine radio resource management policies.

[0160] Step 302: AMF interacts with AM PCF to establish AM policy association.

[0161] For example, the AMF sends an Npcf_AMPolicyControl_Create request message to the AM PCF. This message includes the terminal's identification information, the subscribed service area restriction information, and the subscribed RFSP. The terminal's identification information can be a subscription permanent identifier (SUPI) or a generic public subscription identifier (GPSI).

[0162] The AM PCF determines the AM policy based on the signed service area restriction information, the signed RFSP, and the network policy. The AM policy includes the authorized service area restriction information and the authorized RFSP. Specifically, the AM PCF determines the authorized service area restriction information based on the signed service area restriction information and the network policy, and determines the authorized RFSP based on the signed RFSP and the network policy.

[0163] Then AM PCF sends an Npcf_AMPolicyControl_Create response message to AMF, which contains the AM policy.

[0164] Step 303: AM PCF sends a registration request message to BSF. Accordingly, BSF receives the registration request message.

[0165] The registration request message contains AM PCF binding information, which includes the AMF PCF identifier and the terminal identifier. The AMF PCF identifier can be a resource identifier that supports the Npcf_AmPolicyAuthorization service.

[0166] Optionally, the registration request message can be an Nbsf_Menagement_Register Request message.

[0167] In step 304, the AF sends a subscription request message to the BSF. The BSF then receives the subscription request message.

[0168] The subscription request message contains the terminal's identification information and is used to subscribe to the registration information of the AM PCF that provides AM policies for the terminal.

[0169] Optionally, the subscription request message can be an Nbsf_Management_Subscribe Request message.

[0170] Optionally, step 304 can be performed before step 301.

[0171] Step 305: BSF sends a notification message to AF, and AF receives the notification message accordingly.

[0172] The notification message contains registration information corresponding to the terminal's identification information, which includes the AM PCF's identifier.

[0173] Optionally, the notification message can be an Nbsf_Management_Notify Request message.

[0174] Step 306: AF sends an AM policy authorization request message to AM PCF, and AM PCF receives the AM policy authorization request message accordingly.

[0175] Optionally, the AM policy authorization request message can be an Npcf_AMPolicyAuthorization_CreateRequest message.

[0176] The AM policy authorization request message contains application layer information, which includes any one of the following information 1 to information 4: Information 1: Terminal identification information, service area coverage, and associated (DNN, S-NSSAI) combinations; Information 2: Terminal identification information, high throughput indication, and associated (DNN, S-NSSAI) combination; Information 3: Terminal identification information, service area coverage, associated (DNN, S-NSSAI) combination, and at least one application identifier (Application Id). Information 4: Terminal identification information, high throughput indication, associated (DNN, S-NSSAI) combination, and identification of at least one application.

[0177] Among them, the (DNN, S-NSSAI) combination of information 3 above is optional information, and the (DNN, S-NSSAI) combination of information 4 above is also optional information.

[0178] Here, DNN is short for data network name, and S-NSSAI stands for single network slice selection assistance information.

[0179] The service area coverage refers to the information provided by AF regarding the areas requiring policy control. A high throughput indicator can be a descriptive message used to indicate high throughput.

[0180] Optionally, the AF can also subscribe to service area coverage change events or AM policy change events from the AM PCF through the AM policy authorization request message. For example, the AM policy authorization request message can carry the identifier of the service area coverage change event and the notification endpoint, or it can carry the identifier of the AM policy change event and the notification endpoint. The notification endpoint can be the address of the AF.

[0181] Optionally, after saving the received information, the AM PCF can also send an AM policy authorization response message to the AF. Optionally, this AM policy authorization response message can be an Npcf_AMPolicyAuthorization_Createresponse message.

[0182] Step 307: AM PCF sends a subscription request message to BSF. Accordingly, BSF receives the subscription request message.

[0183] This subscription request message is used to subscribe to the binding information of SM PCF. The subscription request message carries the terminal's identification information and the (DNN, S-NSSAI) combination.

[0184] Optionally, the subscription request message can be an Nbsf_Management_Subscribe Request message.

[0185] Step 308: The terminal establishes a PDU session, which corresponds to the (DNN, S-NSSAI) combination.

[0186] During the establishment of a PDU session by a terminal, the SMF assigns the terminal's address to the PDU session. The SMF interacts with the SM PCF to establish an SM policy association. For example, the SMF sends an Npcf_SMPolicyControl_Create request message to the SM PCF, which includes the terminal's identification information and address. Upon receiving this message, if the SM PCF does not have the terminal's subscription data, it can interact with the UDR to obtain the terminal's subscription data. Then, the SM PCF determines the SM policy based on the terminal's subscription data and network policies. The SM PCF sends an Npcf_SMPolicyControl_Createresponse message to the SMF, which carries the SM policy.

[0187] Step 309: SM PCF sends a registration request message to BSF, and BSF receives the registration request message accordingly.

[0188] The registration request message contains the binding information of the SM PCF, which includes the terminal address, the terminal identification information, the (DNN, S-NSSAI) combination, and the identifier of the SM PCF. The identifier of the SM PCF may be a resource identifier that the SM PCF supports the Npcf_PolicyAuthorization service.

[0189] Optionally, the registration request message can be an Nbsf_Menagement_Register Request message.

[0190] Step 310: BSF sends the binding information of SM PCF to AM PCF based on AM PCF's subscription.

[0191] Optionally, the BSF sends an Nbsf_Management_Notify Request message to the AM PCF, which contains the binding information of the SM PCF.

[0192] Step 311: AM PCF sends a subscription request message to SM PCF, and SM PCF receives the subscription request message accordingly.

[0193] Step 311 is optional. Specifically, if the policy authorization request message in step 306 contains the identifier of at least one application, that is, if the policy authorization request message in step 306 contains information 3 or information 4, then step 311 is executed. The subscription request message contains the identifier of at least one application for subscribing to application start / stop events.

[0194] Optionally, the subscription request message can be an Npcf_PolicyAuthorization_Subscribe Request message.

[0195] Step 312, SM PCF detects application start / stop events.

[0196] For example, the SM PCF interacts with the SMF to request the detection of application start / stop events, and then the SMF interacts further with the UPF to request the UPF to detect application start / stop events.

[0197] Step 312 is optional. If step 311 is performed, then step 312 is performed.

[0198] Step 313: When the SM PCF receives an application start event report from the SMF, the SM PCF sends a notification message to the AM PCF, and the AM PCF receives the notification message accordingly.

[0199] The notification message contains the application's identifier and the application start event.

[0200] Optionally, the notification message can be an Npcf_PolicyAuthorization_Notify Request message.

[0201] Step 314, AM PCF updates AM policy.

[0202] In one implementation, if the AM policy authorization request message in step 306 carries either information 1 or information 2, then after receiving the binding information from the SM PCF in step 310, the AM PCF determines that the PDU session has been established and proceeds to update the AM policy. The AM PCF receiving the binding information from the SM PCF indicates that the SM PCF has been selected, and the selection of the SM PCF is contingent upon the PDU session being established.

[0203] In another implementation, if the AM policy authorization request message in step 306 carries information 3 or 4, then after receiving the application start event in step 313, the AM PCF determines that the PDU session has been established, and the AM PCF then determines to update the AM policy. Here, the AM PCF receiving the application start event indicates that the application has started, and the prerequisite for application start is that the PDU session has been established.

[0204] Specifically, the AM PCF updates the AM policy by: updating the authorized service area restriction information in step 302 based on the received service area coverage, thus obtaining updated service area restriction information; and updating the authorized RFSP in step 302 based on the received high throughput indication, thus obtaining updated RFSP. The updated AM policy includes the updated service area restriction information and the updated RFSP.

[0205] Step 315: The AM PCF sends the updated AM policy to the AMF. The AMF then receives the updated AM policy.

[0206] The updated AM policy includes updated service area restriction information and updated RFSP.

[0207] Optionally, the AMF can send an Npcf_AmPolicyControl_UpdateNotify request message to the AMF, which includes updated service area restriction information and updated RFSP.

[0208] Step 316: AMF executes the updated AM policy.

[0209] That is, AMF performs control over the terminal according to the updated AM policy.

[0210] Step 317: AMF sends a notification message to the terminal, which contains updated service area restriction information.

[0211] The terminal determines the areas it can access based on the updated service area restriction information.

[0212] Step 318: The AMF sends a notification message to the base station, which contains updated service area restriction information and updated RFSP.

[0213] The base station controls terminal access based on updated service area restriction information and determines radio resource management policies based on updated RFSP.

[0214] Step 319: AM PCF sends event notifications and updated AM policies to AF.

[0215] This step is optional. Specifically, if AF subscribed to a service area coverage change event or an AM policy change event in step 306 above, then step 319 is executed.

[0216] Optionally, the AM PCF can send event notifications and updated AM policies to the AF via the Npcf_AMPolicyAuthorization_Notify message.

[0217] The above scheme enables AM PCF to update AM policy based on application layer information provided by AF, thereby obtaining an accurate AM policy, which is beneficial for implementing precise control of the terminal based on the accurate AM policy.

[0218] Figure 4 This is a schematic diagram illustrating the process of AM policy generation and usage provided in an embodiment of this application. This embodiment is an example for a terminal group or any terminal.

[0219] Steps 401 to 402 are the same as steps 301 to 302.

[0220] Step 403: AM PCF sends a subscription request message to UDR, and UDR receives the subscription request message accordingly.

[0221] This subscription request message contains the (S-NSSAI, DNN) combination and the external group identifier. This subscription request message is used to subscribe to application data related to AM, or in other words, to subscribe to AM influence information.

[0222] AM impact information can also be referred to as application layer information.

[0223] Optionally, the subscription request message can be a Nudr_DM_Subscribe request message.

[0224] Step 404: The AF sends AM impact information to the UDR. Correspondingly, the UDR receives the AM impact information.

[0225] For example, the AF can send AM influence information to the UDR through the NEF. Specifically, the AF sends an Nnef_AMInfluence_Create request message to the NEF, which carries the AM influence information. Then, the NEF sends a Nudr_DM_Create Request message to the UDR, which also carries the AM influence information. Optionally, the UDR sends a Nudr_DM_Create Response message to the NEF, and then the NEF sends an Nnef_AMInfluence_Create Response message to the AF.

[0226] The AM impact information includes any one of the following information 1 to information 4: Information 1: External group identifier or any terminal indication, service area coverage, and associated (DNN, S-NSSAI) combination; Information 2: External group identifier or arbitrary terminal indication, high throughput indication, and associated (DNN, S-NSSAI) combination; Information 3: External group identifier or any terminal indication, service area coverage, associated (DNN, S-NSSAI) combination, and at least one application identifier (Application Id). Information 4: External group identifier or arbitrary terminal indication, high throughput indication, associated (DNN, S-NSSAI) combination, and identifier of at least one application.

[0227] Among them, the (DNN, S-NSSAI) combination of information 3 above is optional information, and the (DNN, S-NSSAI) combination of information 4 above is also optional information.

[0228] The meanings of service area coverage and high throughput indication can be found in the description in step 306.

[0229] Optionally, in this step, the AF can also subscribe to service area coverage change events or AM policy change events from the UDR via NEF. For example, the AM impact information may also include the identifier and notification endpoint of the service area coverage change event, or the identifier and notification endpoint of the AM policy change event. The notification endpoint can be the address of the AF.

[0230] Optionally, step 404 can be performed before step 401 above.

[0231] In step 405, the UDR sends a notification message to the AM PCF. The AM PCF then receives this notification message.

[0232] The notification message contains information about the AM impact.

[0233] Optionally, the notification message can be a Nudr_DM_Notify request message.

[0234] Step 406: AM PCF sends a subscription request message to BSF. Accordingly, BSF receives the subscription request message.

[0235] The subscription request message contains the terminal's identification information and the (DNN, S-NSSAI) combination. This subscription request message is used to subscribe to SM PCF binding information.

[0236] The terminal identified by the terminal identification information in the subscription request message is the terminal mentioned in step 401 above. Specifically, if the AM PCF determines that the received AM influence information applies to the terminal in step 401, then it determines that the subscription request message carries the identification information of that terminal.

[0237] Steps 407 to 409 are the same as steps 308 to 310.

[0238] Step 410: AM PCF sends a subscription request message to SM PCF, and SM PCF receives the subscription request message accordingly.

[0239] Step 410 is optional. Specifically, if the notification message in step 405 contains the identifier of at least one application, that is, if the notification message in step 405 contains information 3 or information 4, then step 410 is executed. The subscription request message contains the identifier of at least one application for subscribing to application start / stop events.

[0240] Optionally, the subscription request message can be an Npcf_PolicyAuthorization_Subscribe Request message.

[0241] Steps 411 to 412 are the same as steps 312 to 313.

[0242] Step 413, AM PCF updates AM policy.

[0243] In one implementation, if the notification message in step 405 carries either information 1 or information 2, then after receiving the binding information from the SM PCF in step 409, the AMPCF determines that the PDU session has been established, and the AM PCF then determines to update the AM policy. The AM PCF receiving the binding information from the SM PCF indicates that the SM PCF has been selected, and the prerequisite for the SM PCF to be selected is that the PDU session has been established.

[0244] In another implementation, if the notification message in step 405 carries information 3 or information 4, then after receiving the application start event in step 412, the AM PCF determines that the PDU session has been established and updates the AM policy. The AM PCF receiving the application start event indicates that the application has started, and the prerequisite for application start is that the PDU session has been established.

[0245] Specifically, the AM PCF updates the AM policy by updating the authorized service area restriction information in step 402 based on the received service area coverage, and updating the authorized RFSP in step 402 based on the received high throughput indication, thus obtaining the updated RFSP.

[0246] In this embodiment of the application, the AM strategy is also called the mobility management strategy, which will be explained here for the time being and will not be repeated hereafter.

[0247] Steps 414 to 417 are the same as steps 315 to 318.

[0248] Step 418, AM PCF sends an event notification and an updated AM policy to AF.

[0249] This step is optional. For example, if AF subscribed to a service area coverage change event or an AM policy change event in step 405 above, then step 418 is executed.

[0250] Optionally, the AM PCF can send event notifications and updated AM policies to the NEF via the Npcf_AMPolicyAuthorization_Notify message, and then the NEF can send event notifications and updated AM policies to the AF via the Nnef_AMInfluence_Notify message.

[0251] The above scheme enables AM PCF to update AM policy based on application layer information provided by AF, thereby obtaining an accurate AM policy, which is beneficial for implementing precise control of the terminal based on the accurate AM policy.

[0252] Currently, each BSF registers its information with the NRF so that other network elements can discover it. When registering information, the BSF typically uses the IP address range of the terminals it serves as an index, so that other network elements can obtain the BSF corresponding to the terminal's IP address from the NRF.

[0253] In the above Figure 3 or Figure 4 In the process, in order to find the corresponding SM PCF, the AM PCF sends a subscription request message to the BSF to request to subscribe to the binding information of the SM PCF.

[0254] However, in the above Figure 3 or Figure 4In this process, the AM PCF cannot obtain the terminal's IP address, therefore the AM PCF cannot obtain the BSF corresponding to that terminal's IP address from the NRF. Consequently, when multiple distributed BSFs exist in the network, the AM PCF needs to send a subscription request message to each BSF, which increases signaling overhead and wastes resources.

[0255] To accurately determine mobility management policies and reduce signaling overhead and resource waste in the process of determining mobility management policies, this application provides a communication method, as shown in Figure 5(a). In this method, a first PCF (Alternate Mobile Functions Filter) is used to formulate a mobility management policy; the first PCF can also be called an AM PCF. A second PCF (Alternate Mobile Functions Filter) is used to formulate a session management policy; the second PCF can also be called an SM PCF. In a scenario where the terminal moves, the first PCF refers to the AM PCF that provides services to the terminal after the terminal moves. Therefore, in this method, the first PCF can represent either the AM PCF that provides services to the terminal when the terminal does not move, or the AM PCF that provides services to the terminal after the terminal moves.

[0256] The method includes the following steps: Step 501a: The first PCF sends a request message to the UDR, and the UDR receives the request message accordingly.

[0257] The request message contains the terminal's identification information, event identification information, and notification address. This request message is used to request the UDR to save the event identification information and notification address, or it can be understood as requesting the UDR to save the event identification information and notification address to information associated with the terminal's identification information, such as saving it to the terminal's subscription data indicated by the terminal's identification information. Optionally, the UDR may also store the terminal's identification information.

[0258] As one implementation method, the event identification information and notification address can be collectively referred to as event subscription information, or the request message can contain the terminal's identification information and event subscription information, with the event subscription information containing the event identification information and notification address.

[0259] As one implementation method, the request message may also include a notification correlation ID, which is used to distinguish the event identification information and notification address of different terminals.

[0260] In one implementation, the request message includes a Uniform Resource Identifier (URI), which contains the terminal's identification information. For example, the URI in the request message is {apiRoot} / nudr-dr / <apiversion>The terminal's identification information is the ueId in the URI / policy-data / ues / {ueId} / sm-data.

[0261] The terminal identification information is used to identify the terminal. The terminal identification information can be SUPI, GPSI, or the group identifier of the group to which the terminal belongs.

[0262] Event identification information is used to indicate the status of a detection session or application. For example, when event identification information is used to indicate the status of a detection session, the event identification information can be the status of a PDU session (PDU Session Status) or the establishment / termination of a PDU session (PDU Session Establishment / Termination). Similarly, when event identification information is used to indicate the status of a detection application (application status), the application status can be application detection or application start / stop.

[0263] For example, when the event identification information is used to indicate the status of the detection application, the request message may also contain the identifier of at least one application, in which case the event identification information is used to indicate the status of the at least one application.

[0264] The notification address is the address used to receive event notifications corresponding to the event identifier information. This event notification address is the address of the first PCF. This notification address can also be called the notification target address.

[0265] In step 502a, the UDR sends the event identification information and notification address to the second PCF, and the second PCF receives the event identification information and notification address accordingly.

[0266] If the event identification information in step 501a is used to indicate the status of the detection application, then the request message also contains the identification of at least one application. Therefore, in step 502a, the UDR also sends the identification information of the at least one application to the second PCF.

[0267] As one implementation method, if the request message in step 501a contains a notification association identifier, then in step 502a, the UDR also sends the notification association identifier to the second PCF.

[0268] As one implementation method, the second PCF sends a query request message to the UDR. This query request message contains the terminal's identification information and is used to request the terminal's subscription data. Then, the UDR retrieves the terminal's subscription data from its stored information based on the query request message. This subscription data includes the event identification information and notification address mentioned in step 501a above. Next, the UDR sends a query response message to the second PCF. This response message includes the terminal's subscription data, which also contains the aforementioned event identification information and notification address. Based on this method, the UDR sends the event identification information and notification address to the second PCF in real time based on the second PCF's query request, helping the second PCF to obtain the event identification information and notification address promptly.

[0269] As another implementation method, the second PCF sends a subscription data request message to the UDR. This subscription data request message contains the terminal's identification information and is used to request notification of changes to the terminal's subscription data. Then, based on this subscription data request message, once the UDR detects a change in the terminal's subscription data stored in the UDR, the UDR sends a notification message to the second PCF. This notification message includes the terminal's changed subscription data, which contains event identification information and a notification address. For example, if the second PCF sends the subscription data request message to the UDR before step 501a, and the UDR receives the request message from the first PCF in step 501a, it is triggered to update the terminal's subscription data stored in the UDR based on the received event identification information and notification address, thereby triggering the UDR to send the notification message to the second PCF. Based on this method, the UDR sends event identification information and notification address to the second PCF based on the subscription data subscription request message of the second PCF. This method does not require the second PCF to frequently send query request messages to the UDR to request the subscription data of the query terminal, thus reducing signaling overhead.

[0270] Step 503a: The second PCF detects the state of the terminal's session or the state of the terminal's application based on the event identifier information.

[0271] For example, if the event identification information is used to indicate the status of the detection session, then the second PCF detects the status of the terminal's session. The detected session status can be either PDU session establishment or PDU session termination.

[0272] For example, if the event identifier information is used to indicate the status of the detected application, then the second PCF detects the status of the terminal's application. Specifically, the second PCF detects the status of the application indicated by the identifier of at least one application carried in the request message of step 501a above. The detected application status can be either application started or application stopped.

[0273] Step 504a: The second PCF sends a notification message to the first PCF according to the notification address, and the first PCF receives the notification message accordingly.

[0274] The notification message contains the state of the terminal's session or the state of the terminal's application.

[0275] As one implementation method, if the UDR also sends a notification association identifier to the second PCF in step 502a above, the notification message may also carry the notification association identifier.

[0276] As one implementation method, the notification message may also include at least one of the terminal's session identifier, the terminal's address, or the identifier of the second PCF.

[0277] Step 505a: The first PCF determines the mobility management policy based on the state of the terminal's session or the state of the terminal's application.

[0278] For example, when the first PCF receives the session status of the terminal and the session status of the terminal is "session established", the first PCF determines the mobility management policy based on the application layer information from the AF.

[0279] For example, when the first PCF receives the session status of the terminal and the session status of the terminal is "session terminated", the first PCF does not determine the mobility management policy based on the application layer information from the AF. For example, the first PCF can determine the mobility management policy based on the terminal's subscription data.

[0280] For example, when the first PCF receives the application status of the terminal and the application status of the terminal is "application started", the first PCF determines the mobility management policy based on the application layer information from the AF.

[0281] For example, when the first PCF receives the status of the terminal's application and the application status is "application stopped", the first PCF does not determine the mobility management policy based on the application layer information from the AF. For example, the first PCF can determine the mobility management policy based on the terminal's subscription data.

[0282] The first PCF determines the specific implementation method of the mobility management strategy based on the application layer information from the AF, which can be referred to in the description of step 314 or step 413 above.

[0283] According to the methods in steps 501a to 505a above, the first PCF can determine the mobility management policy based on the state of the terminal's session or the state of the application, thus achieving precise determination of the mobility management policy. Furthermore, compared to... Figure 3 or Figure 4 The method shown in Figure 5(a) does not require the first PCF to send a subscription request message to each BSF in the network. Instead, it only needs to send a request message to a UDR to receive the state of the terminal's session or application. Therefore, it can reduce the signaling overhead and resource waste in the process of determining mobility management policies.

[0284] As one implementation method, the event identification information in step 501a can be determined by the first PCF based on the application layer information from the AF. That is, before step 501a, the first PCF receives the application layer information from the AF, and then the first PCF determines the event identification information based on the application layer information. For example, when the application layer information sent by the AF to the first PCF is for a single terminal, the application layer information can be any one of information 1 to information 4 described in step 306. Optionally, when the application layer information is information 1 or information 2 described in step 306, the event identification information is used to indicate the status of the detection session; when the application layer information is information 3 or information 4 described in step 306, the event identification information is used to indicate the status of the detection application. For another example, when the application layer information sent by the AF to the first PCF is for any terminal or terminal group, the application layer information can be any one of information 1 to information 4 described in step 404. Optionally, when the application layer information is information 1 or information 2 described in step 404 above, the event identification information is used to indicate the state of the detection session; when the application layer information is information 3 or information 4 described in step 404 above, the event identification information is used to indicate the state of the detection application.

[0285] As one implementation method, if the first PCF receives application layer information from the AF before step 501a, the request message in step 501a may also include a (DNN, S-NSSAI) combination. This (DNN, S-NSSAI) combination comes from the application layer information of the AF. This request message is used to request the UDR to save the event identifier information and notification address to the subscription data of the terminal corresponding to the (DNN, S-NSSAI) combination. If the request message in step 501a includes the (DNN, S-NSSAI) combination, then in step 502a, the UDR sends the event identifier information and notification address corresponding to the (DNN, S-NSSAI) combination to the second PCF. This can also be understood as the second PCF corresponding to the (DNN, S-NSSAI) combination. Therefore, the query request message sent by the second PCF to the UDR in step 502a above can include the (DNN, S-NSSAI) combination. This query request message is used to request the query terminal's subscription data corresponding to the (DNN, S-NSSAI) combination. Alternatively, the subscription data subscription request message sent by the second PCF to the UDR in step 502a above can include the (DNN, S-NSSAI) combination. This subscription data subscription request is used to request notification of changes to the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination. Based on this method, fine-grained management of event identification information based on the (DNN, S-NSSAI) combination can be achieved.

[0286] As one implementation method, if the request message in step 501a contains the (DNN, S-NSSAI) combination, the request message may also contain first indication information. This first indication information indicates a notification strategy: a notification message is sent when the first session corresponding to the (DNN, S-NSSAI) combination is established, and / or when the last session corresponding to the (DNN, S-NSSAI) combination terminates. The UDR also stores this first indication information. Subsequently, in step 502a, when the UDR sends event identifier information and notification address to the second PCF, it also sends this first indication information to the second PCF. Based on this first indication information, the second PCF sends a notification message containing the state of the first session to the first PCF when it detects the state of the first session among multiple sessions, and / or sends a notification message containing the state of the last session to the first PCF when it detects the state of the last session among multiple sessions. For the states of other sessions besides the first and last sessions, the second PCF does not need to send the states of those other sessions to the first PCF. This method can reduce signaling overhead.

[0287] As one implementation method, the mobility management policy determined in step 505a above includes second indication information, which indicates that the mobility management policy is determined based on application layer information. Subsequently, the mobility management policy can be sent to the AMF, base station, and terminal, so that the AMF, base station, and terminal can know that the mobility management policy is determined based on application layer information, which helps to ensure the reasonable use of the mobility management policy.

[0288] As one implementation method, after step 505a above, the first PCF can send the mobility management policy to the AF. For example, the first PCF sends the mobility management policy to the AF based on the AF's subscription, or the first PCF actively sends the mobility management policy to the AF.

[0289] As one implementation method, after step 505a above, the UDR can also send a response message to the first PCF in response to the request message. This response message includes first identification information, which is the identification information of the event identification information and the notification address. This first identification information is used to modify or delete the event identification information and / or the notification address. That is, subsequently, the first PCF or other PCFs can modify or delete the event identification information and / or the notification address saved by the first PCF to the UDR based on this first identification information. According to this method, rapid modification or deletion of the event identification information and notification address saved by the UDR can be achieved.

[0290] As one implementation method, when the first PCF is an AM PCF that provides services to the terminal after the terminal moves, before step 501a above, the first PCF can receive third indication information from the AMF. This third indication information indicates that the mobility management policy used by the terminal is determined based on application layer information. Therefore, the first PCF delays determining the mobility management policy based on this third indication information, or it can be understood that the first PCF determines, based on the third indication information, that the mobility management policy is not determined based on the terminal's subscription data. Then, based on the third indication information, the first PCF triggers the execution of steps 501a to 505a above, realizing the determination of the mobility management policy based on application layer information. This method helps to achieve accurate determination of the mobility management policy.

[0291] To accurately determine mobility management policies and reduce signaling overhead and resource waste in the process of determining mobility management policies, this application provides a communication method, as shown in Figure 5(b). This method is applicable to scenarios where the terminal moves. In this method, a first PCF and a third PCF are used to formulate mobility management policies. Both the first PCF and the third PCF can be referred to as AM PCFs. The first PCF provides services to the terminal after it moves, and the third PCF provides services to the terminal before it moves. A second PCF is used to formulate session management policies; the second PCF can be referred to as SM PCF.

[0292] The method includes the following steps: Step 501b: The first PCF sends a request message to the UDR, and the UDR receives the request message accordingly.

[0293] The request message contains the first identification information and the first notification address.

[0294] The first notification address is the event notification address used to receive the event identifier information, and this event notification address is the address of the first PCF.

[0295] The first identification information consists of the event identification information stored in the UDR and the identification information of the second notification address. The event identification information is used to indicate the state of the detection session or the application; the specific meaning of this event identification information can be found in the description in step 501a. The second notification address is the address of the third PCF used to receive event notifications corresponding to the event identification information.

[0296] For example, the method by which the first PCF obtains the first identification information may be as follows: after the third PCF saves the event identification information and the second notification address to the UDR, the UDR generates the first identification information based on the event identification information and the second notification address, and then sends the first identification information to the third PCF. Then, the third PCF sends the first identification information to the first AMF that previously provided services to the terminal, and then the first AMF sends the first identification information to the second AMF that subsequently provides services to the terminal, so that the second AMF can send the first identification information to the first PCF.

[0297] This request message is used to request the UDR to update the saved second notification address to the first notification address.

[0298] As one implementation method, the request message may also include a first notification association identifier allocated by the first PCF. The first notification association identifier is used to distinguish the event identification information and notification address of different terminals. Then, the request message is also used to request the UDR to update the saved second notification association identifier to the first notification association identifier. The second notification association identifier is sent to the UDR by the third PCF when saving the event identification information and the second notification address to the UDR.

[0299] In step 502b, the UDR updates the saved second notification address to the first notification address.

[0300] For example, before step 501b, the UDR receives event identification information and a second notification address from the third PCF, and then saves the event identification information and the second notification address. Then, after receiving the aforementioned request message, the UDR updates the saved second notification address to the first notification address, so that after the update occurs, the UDR saves the event identification information and the first notification address.

[0301] As one implementation method, UDR also updates the saved second notification association identifier to the first notification association identifier.

[0302] In step 503b, the UDR sends the event identification information and the first notification address to the second PCF, and the second PCF receives the event identification information and the first notification address accordingly.

[0303] As one implementation method, in step 503b, the UDR also sends a first notification association identifier to the second PCF.

[0304] The specific implementation of step 503b is similar to that of step 502a above, and can be referred to the above description.

[0305] Step 504b: The second PCF detects the state of the terminal's session or the state of the terminal's application based on the event identifier information.

[0306] The specific implementation of step 504b is the same as that of step 503a above, and can be referred to the foregoing description.

[0307] Step 505b: The second PCF sends a notification message to the first PCF according to the first notification address, and the first PCF receives the notification message accordingly.

[0308] As one implementation method, the notification message also includes a first notification association identifier.

[0309] The notification message contains the state of the terminal's session or the state of the terminal's application.

[0310] Step 506b: The first PCF determines the mobility management policy based on the state of the terminal's session or the state of the terminal's application.

[0311] The specific implementation of step 506b is the same as that of step 505a above, and can be referred to the foregoing description.

[0312] According to the methods in steps 501b to 506b above, the first PCF can determine the mobility management policy based on the state of the terminal's session or the state of the application, thus achieving precise determination of the mobility management policy. Furthermore, compared to... Figure 3 or Figure 4 The method in Figure 5(b) does not require the first PCF to send a subscription request message to every BSF in the network. Instead, it only needs to send a request message to a UDR to receive the terminal's session status or application status. Therefore, it can reduce signaling overhead and resource waste in the process of determining mobility management policies. In addition, compared with the method in Figure 5(a), in the method in Figure 5(b), the first PCF can modify the notification address stored in the UDR according to the first identification information, which can reduce the signaling load and help save resources.

[0313] Other possible implementation methods based on the embodiment of Figure 5(b), such as the implementation method based on (DNN, S-NSSAI) combination, the implementation method based on application layer information, the implementation method based on the first indication information, the implementation method based on the second indication information, and the implementation method based on the third indication information, are all similar to the various implementation methods in the embodiment of Figure 5(a). Please refer to the foregoing description and they will not be repeated here.

[0314] To achieve accurate determination of mobility management policies and reduce signaling overhead and resource waste in the process of determining mobility management policies, this application provides another communication method, as shown in Figure 5(c). In this method, a first PCF is used to formulate a mobility management policy, which can also be called an AM PCF, and a second PCF is used to formulate a session management policy, which can also be called an SM PCF.

[0315] The method includes the following steps: Step 501c: The first PCF sends a first request message to the AMF, and the AMF receives the first request message accordingly.

[0316] The first request message contains event identification information, which is used to indicate the state of the terminal's session or the state of the terminal's application. The event corresponding to the event identification information is the state of the terminal's session or the state of the terminal's application. The specific implementation of the event identification information can be found in the description in step 501a.

[0317] The first request message is used to request the event notification corresponding to the event identifier information.

[0318] For example, the first PCF can send the first request message to the AMF on the terminal's session, so that the AMF can know which terminal's session status or application status is being checked.

[0319] Optionally, the event identifier information in the first request message may be determined by the first PCF based on application layer information from the AF. The specific method by which the first PCF determines the event identifier information based on application layer information from the AF can be found in the relevant description in the embodiment of Figure 5(a).

[0320] Optionally, the first request message may further include a (DNN, S-NSSAI) combination, which is used to request the state of the session or application corresponding to the (DNN, S-NSSAI) combination on the terminal. The (DNN, S-NSSAI) combination obtained by the first PCF may come from the application layer information of the AF. A detailed description of the application layer information can be found in the descriptions of steps 306 or 404 above.

[0321] Step 502c: AMF detects the event corresponding to the event identifier information.

[0322] The following describes two different implementation methods for AMF to detect events corresponding to event identifier information.

[0323] In the first implementation method, when the event identifier information is the session state, the AMF detects the session state of the terminal.

[0324] According to this first implementation method, the AMF detects the session status of the terminal.

[0325] Optionally, if the first request message further includes the (DNN, S-NSSAI) combination, the first request message is used to request the status of the session or application corresponding to the (DNN, S-NSSAI) combination on the terminal, so that the AMF can detect the status of the session corresponding to the (DNN, S-NSSAI) combination on the terminal. The status of the session includes the establishment or termination of the session corresponding to the (DNN, S-NSSAI) combination. Alternatively, the status of the session is the establishment of the first session corresponding to the (DNN, S-NSSAI) combination, or the termination of the last session corresponding to the (DNN, S-NSSAI) combination.

[0326] Method 2: When the event identifier information is the state of the application or the state of the session, the SMF detects the state of the terminal's session.

[0327] For example, after step 501c above, the AMF sends a second request message to the SMF. This second request message contains the aforementioned event identification information and is used to request event notification corresponding to the event identification information. Then, the SMF detects the event corresponding to the event identification information. After detecting the event, the SMF sends a notification message to the AMF. This notification message contains the application status or session status of the terminal. When the AMF receives this notification message, it indicates that the AMF has detected the event corresponding to the event identification information. Therefore, according to this second implementation method, the AMF detecting the event corresponding to the event identification information can be understood as the AMF receiving the notification message from the SMF.

[0328] In step 503c, the AMF sends a notification message to the first PCF. Correspondingly, the first PCF receives the notification message.

[0329] The notification message contains the state of the terminal's session or the state of the terminal's application, which is detected based on event identifier information.

[0330] If the AMF detects the event corresponding to the event identifier information according to the implementation method of step 502c above, then the notification message contains the state of the terminal's session, and the state of the session is session established.

[0331] If the AMF detects the event corresponding to the event identifier information according to the second implementation method of step 502c above, then the notification message contains the notification message from the SMF, which contains the state of the terminal's session or the state of the terminal's application.

[0332] Step 504c: The first PCF determines the mobility management policy based on the state of the terminal's session or the state of the terminal's application.

[0333] The specific implementation of step 504c is the same as that of step 505a above, and can be referred to the foregoing description.

[0334] According to the methods in steps 501c to 504c above, the first PCF can determine the mobility management policy based on the state of the terminal's session or the state of the application, thus achieving precise determination of the mobility management policy. Furthermore, compared to... Figure 3 or Figure 4 The method shown in Figure 5(c) does not require the first PCF to send a subscription request message to each BSF in the network. Instead, it only needs to send a request message to an AMF to receive the state of the terminal's session or application. Therefore, it can reduce the signaling overhead and resource waste in the process of determining mobility management policies.

[0335] As an alternative implementation, steps 502c and 503c can be omitted. Instead, the following operations can be performed after step 501c and before step 504c: After receiving the first request message, the AMF sends a second request message to the SMF. This second request message contains the aforementioned event identification information and is used to request event notification corresponding to the event identification information. Then, the SMF detects the event corresponding to the event identification information. After detecting the event, the SMF sends a notification message to the first PCF. This notification message contains the application status of the terminal or the session status of the terminal.

[0336] As one implementation method, when the first request message contains the (DNN, S-NSSAI) combination, the first request message may also contain first indication information; or when both the first and second request messages contain the (DNN, S-NSSAI) combination, both the first and second request messages may also contain first indication information. The first indication information is used to indicate a notification strategy: a notification message is sent when the first session corresponding to the (DNN, S-NSSAI) combination is established, and / or a notification message is sent when the last session corresponding to the (DNN, S-NSSAI) combination terminates. Then, based on the first indication information, the AMF or SMF sends a notification message containing the status of the first session to the first PCF when it detects the status of the first session among multiple sessions, and / or sends a notification message containing the status of the last session to the first PCF when it detects the status of the last session among multiple sessions. For the status of other sessions besides the first and last sessions, the AMF or SMF does not need to send the status of those other sessions to the first PCF. According to this method, signaling overhead can be reduced.

[0337] As one implementation method, the mobility management policy determined in step 504c above includes second indication information, which indicates that the mobility management policy is determined based on application layer information. Subsequently, the mobility management policy can be sent to the AMF, base station, and terminal, so that the AMF, base station, and terminal can know that the mobility management policy is determined based on application layer information, which helps to ensure the reasonable use of the mobility management policy.

[0338] As one implementation method, after step 504c above, the first PCF can send the mobility management policy to the AF. For example, the first PCF sends the mobility management policy to the AF based on the AF's subscription, or the first PCF actively sends the mobility management policy to the AF.

[0339] The following examples illustrate the schemes shown in Figures 5(a), 5(b), and 5(c). Specifically, the following... Figure 6 and Figure 7 The example shown is a specific example of the scheme shown in Figure 5(a) above. The following... Figure 8 and Figure 9 The example shown is a specific example of the scheme shown in Figure 5(b) above. The following... Figure 10 and Figure 10 The example shown in (a) is a specific example of the scheme shown in Figure 5(c) above.

[0340] Figure 6 The present application provides a communication method in which the Application Layer Advisor (AF) provides application layer information to a single terminal for AM policy decision-making, and the AM PCF obtains the application layer information from the AF.

[0341] The method includes the following steps: Steps 601 to 606 are the same as steps 301 to 306 above.

[0342] In step 607, the AM PCF sends an update request message to the UDR. The UDR then receives the update request message.

[0343] This update request message is a specific example of the request message in step 501a above.

[0344] The update request message contains event subscription information, terminal identification information, and a (DNN, S-NSSAI) combination. This update request message is used to request the UDR to save the event subscription information in the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination.

[0345] The event subscription information includes a notification address and an event identifier. The notification address can be an AM PCF address. Optionally, when the AM PCF needs to save event subscription information for multiple terminals to the UDR, if the AM PCF has assigned the same notification address to different terminals, the event subscription information can also include a notification association identifier, which is used to distinguish the event subscription information of different terminals.

[0346] Optionally, the update request message can be a Nudr_DM_Update Request message.

[0347] As one implementation method, the condition for triggering AM PCF to execute step 607 could be, for example, that AM PCF receives application layer information from AF for deciding AM policy. Then, AM PCF determines that it needs to determine AM policy information based on the application layer information, and thus decides to send the aforementioned update request message to UDR. Furthermore, AM PCF determines, based on the received application layer information, that it also needs to know the status of the PDU session or the application status. Specifically, the PDU session status is either established or terminated, and the application status is either started or stopped.

[0348] As one implementation method, if the AM policy authorization request message in step 606 includes information 1 or information 2, the event identification information can be set to the state of the PDU session (or PDU Sessionestablishment / termination). If the AM policy authorization request message in step 606 includes information 3 or information 4, the event identification information can be set to application detection (or Application start / stop). Wherein, when the event identification information is application detection, the event subscription information also includes the identifier of at least one application.

[0349] As one implementation method, the event subscription information mentioned above can also include indication information. This indication information is used to indicate the notification strategy, which is as follows: For multiple PDU sessions controlled by the SM PCF corresponding to the same (DNN, S-NSSAI) combination, the AM PCF is notified when the first PDU session among the multiple PDU sessions is established, and when the last PDU session among the multiple PDU sessions is terminated (or released). That is, the AM PCF is notified when the first PDU session among the multiple PDU sessions is established, but not when other PDU sessions are established. If no active PDU session exists after a PDU session among the multiple PDU sessions is released, the AM PCF is notified. If at least one active PDU session exists after a PDU session among the multiple PDU sessions is released, the AM PCF is not notified.

[0350] Optionally, after step 607 above, the UDR can send an acknowledgment message to the AM PCF. This message includes an identifier assigned by the UDR to the event subscription information, which the AM PCF can then use to modify or delete the event subscription information. The identifier assigned by the UDR to the event subscription information can be a resource URI, such as: {apiRoot} / nudr-dr / <apiversion> / policy-data / ues / {ueId} / sm-data / subscriptions / {subsId}.

[0351] Step 608 is the same as step 308 above.

[0352] Step 609: The SM PCF sends a query request message to the UDR, and the UDR receives the query request message accordingly.

[0353] The query request message contains the terminal's identification information and the (DNN, S-NSSAI) combination. The query request message is used to request the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination.

[0354] Optionally, the query request message can be an Ndur_DM_Query request message.

[0355] In step 610, the UDR sends a query response message to the SM PCF. The SM PCF then receives the query response message.

[0356] The query response message includes the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination, which contains the aforementioned event subscription information.

[0357] Optionally, the query response message can be a Nudr_DM_Query Response message.

[0358] Step 611: SM PCF sends a subscription request message to UDR, and UDR receives the subscription request message accordingly.

[0359] The subscription request message contains the terminal's identification information and a (DNN, S-NSSAI) combination. This message is used to request subscription to the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination. That is, when the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination in the UDR changes, the UDR actively notifies the SM PCF. Changes to the subscription data include changes to event subscription information.

[0360] Optionally, the subscription request message can be an Ndur_DM_Subscribe request message.

[0361] In step 612, the UDR sends a subscription response message to the SM PCF. The SM PCF then receives this subscription response message.

[0362] Optionally, the subscription response message can be an Ndur_DM_Subscribe response message.

[0363] As one implementation method, steps 609 to 610 above can be performed, but steps 611 to 612 above are not performed.

[0364] As one implementation method, steps 611 to 612 above can be performed, but steps 609 to 610 above are not performed.

[0365] As one implementation method, steps 609 to 610 above, as well as steps 611 to 612 above, are executed.

[0366] Step 613, SM PCF detects application start / stop events.

[0367] Specifically, the SM PCF interacts with the SMF to request the detection of application start / stop events, and then the SMF interacts further with the UPF to request the UPF to detect application start / stop events.

[0368] This step is optional. Specifically, when the event identification information in the event subscription information obtained by SM PCF is application detection, this step 613 is executed.

[0369] Step 614: SM PCF sends a notification message to AM PCF, and AM PCF receives the notification message accordingly.

[0370] As one implementation method, if the event identifier information in the event subscription information is the state of the PDU session, then the SMPCF sends the notification message to the AM PCF according to the notification address in the event subscription information. The notification message contains indication information indicating that the PDU session has been established.

[0371] As another implementation method, if the event identifier information in the event subscription information is application detection, and the SMF reports to the SMPCF that an application start event corresponding to the application identifier has been detected, then the SMPCF sends the notification message to the AM PCF according to the notification address. This notification message contains indication information indicating that the application has started. Optionally, if the event subscription information includes identifiers of multiple applications, then the notification message also includes the identifier of the application that has started.

[0372] Optionally, if the event subscription information includes a notification association identifier, then the notification message includes that notification association identifier.

[0373] Optionally, when the UE establishes multiple PDU sessions for the same (DNN, S-NSSAI) combination, and these multiple PDU sessions select different SMFs, and the SMFs select different SM PCFs (i.e., multiple SM PCFs have received the event subscription information), then each SM PCF sends a notification message to the AM PCF when it detects the event corresponding to the event subscription information. The notification message includes at least one of the following: the identifier of the SM PCF, the identifier of the PDU session, or the address of the terminal.

[0374] Optionally, when the SM PCF control corresponds to multiple PDU sessions of the same (DNN, S-NSSAI) combination, the notification message may also include the identifier of the PDU session or the address of the terminal to distinguish different PDU sessions.

[0375] Optionally, the notification message can be an Npcf_PolicyAuthorization_Notify Request message.

[0376] Steps 615 to 620 are the same as steps 314 to 319 above.

[0377] Optionally, in addition to the updated service area restriction information and the updated RFSP, the updated AM policy generated in step 615 may also include indication information, which indicates that the updated AM policy is determined based on the application layer information corresponding to the terminal.

[0378] Optionally, after step 620 above, this embodiment of the application may also perform some or all of the steps in steps 621 to 627.

[0379] Step 621: SM PCF sends a notification message to AM PCF, and AM PCF receives the notification message accordingly.

[0380] As one implementation method, at a certain moment, the SM PCF detects the termination of the PDU session, for example, when the SM PCF receives an SM policy association termination request message sent by the SMF. Then, the SM PCF sends a notification message to the AM PCF according to the notification address in the event subscription information. This notification message contains indication information, which indicates that the PDU session is terminated or released.

[0381] As another implementation method, at a certain time, the SMF reports to the SM PCF that it has detected that the application corresponding to the application's identifier has stopped. The SM PCF then sends a notification message to the AM PCF based on the notification address in the event subscription information. This notification message contains indication information indicating that the application has stopped. Optionally, if the event subscription information includes the identifiers of multiple applications, the notification message also includes the identifier of the stopped application.

[0382] Optionally, if the event subscription information includes a notification association identifier, then the notification message includes that notification association identifier.

[0383] Optionally, when the UE establishes multiple PDU sessions for the same (DNN, S-NSSAI) combination, and these multiple PDU sessions select different SMFs, and the SMFs select different SM PCFs (i.e., multiple SM PCFs have received the event subscription information), the notification message includes at least one of the SM PCF identifier, the PDU session identifier, or the terminal address.

[0384] Optionally, when the SM PCF control corresponds to multiple PDU sessions of the same (DNN, S-NSSAI) combination, the notification message may also include the identifier of the PDU session or the address of the terminal to distinguish different PDU sessions.

[0385] The AM PCF can determine which PDU session has terminated or which application corresponding to which PDU session has stopped based on at least one of the SM PCF identifier, the PDU session identifier, or the terminal address.

[0386] Optionally, the notification message can be an Npcf_PolicyAuthorization_Notify Request message.

[0387] Step 622, AM PCF updates AM policy.

[0388] This AM strategy is also known as the Mobility Management Network Element.

[0389] Specifically, after receiving the notification message from step 621, the AM PCF determines that it will not determine the AM policy based on the application layer information provided by the AF, but rather based on the terminal's subscription data and network policy. The specific implementation of this step can be found in the description of step 302 above.

[0390] Steps 623 to 627 are the same as steps 315 to 319 above.

[0391] Optionally, in addition to the updated service area restriction information and the updated RFSP, the updated AM policy generated in step 622 may also include indication information, which is used to indicate that the updated AM policy is not determined based on the application layer information corresponding to the terminal, or to indicate that the updated AM policy is determined based on the terminal's subscription data.

[0392] According to the above scheme, the SM PCF obtains the event subscription information stored by the AMF in the subscription data from the UDR, and notifies the AM PCF after the PDU session is established or after an application start event is detected, thereby triggering the AM PCF to update the AM policy based on the application layer information from the AF. In this scheme, the AM PCF does not need to subscribe to the SM PCF binding information from the BSF, which avoids the AM PCF subscribing to the SM PCF binding information from every BSF in the network without knowing the terminal's IP address, thus reducing signaling overhead and resource waste.

[0393] Figure 7 The present application provides a communication method in which the AF provides application layer information to a group of terminals or any terminal for AM policy decision-making, and the AM PCF obtains the application layer information from the UDR.

[0394] The method includes the following steps: Steps 701 to 705 are the same as steps 401 to 405 above.

[0395] Steps 706 to 726 are the same as steps 607 to 627 above.

[0396] The beneficial effects of this embodiment can be referred to the foregoing. Figure 6 The beneficial effects of the embodiments will not be elaborated further.

[0397] Figure 8 This application provides a communication method for a policy formulation process following a terminal's movement and execution of an AMF reselection procedure. The method involves the Application Layer Analyzer (AF) providing application layer information to a single terminal for AM policy decision-making, with the target AM PCF obtaining the application layer information from the AF.

[0398] In this method, the AMF accessed before mobility is called the source AMF, or the old AMF. The AMF accessed after mobility is called the target AMF, or the new AMF. The AM PCF providing services to the terminal before mobility is called the source AM PCF, or the old AM PCF, or the third PCF. The AM PCF providing services to the terminal after mobility is called the target AM PCF, or the new AM PCF, or the first PCF.

[0399] The method includes the following steps: In step 801, the terminal moves and sends a registration request message to the base station. The base station then receives the registration request message.

[0400] The registration request message carries the terminal's identification information.

[0401] Step 802: The base station selects a new AMF, i.e., the target AMF.

[0402] Step 803: The base station sends a registration request message to the target AMF. The target AMF receives the registration request message accordingly.

[0403] The registration request message carries the terminal's identification information.

[0404] In step 804a, the target AMF sends a context request message to the source AMF. Correspondingly, the source AMF receives the context request message.

[0405] The context request message contains the terminal's identification information.

[0406] Optionally, the context request message can be a Namf_Communication_UEContextTransferrequest message.

[0407] In step 804b, the source AMF sends a context response message to the target AMF. The target AMF then receives this context response message.

[0408] This context response message contains the terminal's context information, which includes the authorized AM policy received by the source AMF from the source AMPCF. This authorized AM policy includes authorized service area restriction information and / or authorized RFSPs, as detailed above. Figure 6 Description of the embodiments.

[0409] Optionally, the context response message may also include indication information indicating that the AM policy in the context information is determined based on application layer information.

[0410] Optionally, the context response message can be the Namf_Communication_UEContextTransferresponse message.

[0411] Step 805: The target AMF sends a status update message to the source AMF. Correspondingly, the source AMF receives the status update message.

[0412] This status update message indicates that the terminal's status synchronization is complete.

[0413] Optionally, the status update message can be a Namf_Communication_RegistrationStatusUpdate message.

[0414] Step 806: The target AMF selects a target AM PCF and sends an AM policy control request message to the target AM PCF. Correspondingly, the target AMF receives the AM policy control request message.

[0415] The AM policy control request message carries the authorized AM policy. Optionally, the AM policy control request message may also include the indication information from step 804b above.

[0416] Optionally, the AM policy control request message can be an Npcf_AMPolicyControl_Create request message.

[0417] In step 807, the target AM PCF sends a registration request message to the BSF. Correspondingly, the BSF receives the registration request message.

[0418] Specifically, the target AM PCF determines, based on the received authorized AM policy or the received instruction information, not to determine the authorized AM policy based on the terminal's subscription data, but instead sends a registration request message to the BSF. The registration request message includes the binding information of the AM PCF, and the specific content of the binding information of the AM PCF can be referred to the description in 303 above.

[0419] Optionally, the registration request message can be an Nbsf_Menagement_Register Request message.

[0420] In step 808, the BSF sends a notification message to the AF. The AF then receives the notification message.

[0421] Specifically, the BSF sends the notification message to the AF based on the previous subscription of the AF. This notification message includes the identifier of the target AMPCF. The subscription operation of the AF to the BSF can be referred to step 604 above.

[0422] Optionally, the notification message can be an Nbsf_Management_Notify Request message.

[0423] Step 809: AF sends an AM policy authorization request message to the target AM PCF, and the target AM PCF receives the AM policy authorization request message accordingly.

[0424] The specific implementation of this step can be found in the description of step 306 above.

[0425] In step 810, the target AM PCF sends an update request message to the UDR. The UDR then receives the update request message.

[0426] The specific implementation of this step can be found in the description of step 607 above.

[0427] In step 811, the UDR sends a notification message to the SM PCF. The SM PCF then receives the notification message.

[0428] Specifically, based on the previous subscription of the SM PCF, the UDR sends a notification message to the SM PCF. This notification message includes the event subscription information saved by the target AM PCF to the UDR. The subscription operation of the SM PCF to the UDR can be referred to step 609 above.

[0429] Optionally, the notification message can be a Nudr_DM_Notify request message.

[0430] Step 812 is the same as step 613 above.

[0431] Step 813: The SM PCF sends a notification message to the target AM PCF, and the target AM PCF receives the notification message accordingly.

[0432] The specific implementation of this step can be found in the description of step 614 above.

[0433] Step 814: The target AM PCF sends an AM policy control response message to the target AMF. Correspondingly, the target AMF receives the AM policy control response message.

[0434] If the target AM PCF determines that the PDU session has been established or the application has started based on the notification message received in step 813 above, the target AM PCF determines the updated AM policy based on the application layer information received in step 809 above. The updated AM policy includes updated service area restriction information and updated RFSP.

[0435] If the updated AM policy is the same as the authorized AM policy received in step 806 above, the AM policy control response message does not contain the updated AM policy. Optionally, the AM policy control response message may contain an indication message to indicate that the AM policy has not been updated.

[0436] If the updated AM policy is different from the authorized AM policy received in step 806 above, the updated AM policy is included in the AM policy control response message.

[0437] Optionally, the AM policy control response message can be an Npcf_AmPolicyControl_Create response message.

[0438] Step 815: The target AMF executes the updated AM policy.

[0439] That is, AMF performs control over the terminal according to the updated AM policy.

[0440] In step 816, the target AMF sends a registration acceptance message to the terminal. The terminal then receives this registration acceptance message.

[0441] If the target AMF receives the updated AM policy in step 814 above, the registration acceptance message may carry the updated service area restriction information in the updated AM policy.

[0442] Step 817: The target AMF sends a notification message to the base station, which contains updated service area restriction information and updated RFSP.

[0443] The base station controls terminal access based on updated service area restriction information and determines radio resource management policies based on updated RFSP.

[0444] This step is optional. If the target AMF receives an updated AM policy in step 814 above, then step 817 is executed.

[0445] Step 818: The target AM PCF sends an event notification and an updated AM policy to the AF.

[0446] This step is optional. If the target AMF receives an updated AM policy in step 814 above, then step 818 is executed.

[0447] Optionally, the AM PCF can send event notifications and updated AM policies to the AF via the Npcf_AMPolicyAuthorization_Notify message.

[0448] Step 819: The source AMF sends an AM policy deletion message to the source AM PCF. Correspondingly, the source AM PCF accepts the AM policy deletion message.

[0449] The AM policy deletion message is used to request the deletion of AM policy associations.

[0450] Optionally, the AM policy deletion message can be an Npcf_AMPolicyControl_Delete message.

[0451] In step 820, the source AM PCF sends a deregistration request message to the BSF. Correspondingly, the BSF receives the deregistration request message.

[0452] The registration request message is used to request the removal of the binding registration information of the source AM PCF.

[0453] Optionally, the deregistration request message can be an Nbsf_Management_DeregisterRequest message.

[0454] Step 821: The source AM PCF sends an update request message to the UDR. The UDR then receives the update request message.

[0455] The update request message includes indication information and an identifier for the event subscription information. The indication information is used to request the deletion of the event subscription information stored in the UDR. In this embodiment, the identifier for the event subscription information is also referred to as the first identifier information.

[0456] Optionally, the update request message can be a Nudr_DM_Update Request message.

[0457] As one implementation method, if the source AMF sends the identifier of the event subscription information stored in the UDR by the source AM PCF to the target AMF through step 804, the target AMF can send the identifier of the event subscription information to the target AM PCF in step 806. Then, in step 810, the target AM PCF sends an update request message to the UDR. This update request message contains not only the event subscription information, the terminal's identifier information, and the (DNN, S-NSSAI) combination, but also the identifier of the received event subscription information. This update request message is used to request an update to the event subscription information corresponding to the identifier of the event subscription information. Specifically, the notification address in the event subscription information is changed from the address of the source AM PCF to the address of the target AM PCF. In this case, step 821 above does not need to be executed.

[0458] According to the above scheme, in scenarios where terminal movement leads to reselection of both AMF and AM PCF, the AM policy can be updated by the target AM PCF. In this scheme, the target AM PCF does not need to subscribe to the binding information of the SM PCF from the BSF, thus avoiding the need for the target AM PCF to subscribe to the binding information of the SM PCF from every BSF in the network without knowing the terminal's IP address, thereby reducing signaling overhead and resource waste.

[0459] Figure 9 This application provides a communication method for policy formulation after a terminal moves and executes an AMF reselection procedure. The method involves the Application Layer Analyzer (AF) providing application layer information to a group of terminals or any terminal for AM policy decision-making, with the target AM PCF obtaining the application layer information from the User Data Redirector (UDR).

[0460] In this method, the AMF accessed before mobility is called the source AMF, or the old AMF. The AMF accessed after mobility is called the target AMF, or the new AMF. The AM PCF providing services to the terminal before mobility is called the source AM PCF, or the old AM PCF, or the third PCF. The AM PCF providing services to the terminal after mobility is called the target AM PCF, or the new AM PCF, or the first PCF.

[0461] The method includes the following steps: Steps 901 to 903 are the same as steps 801 to 803 above.

[0462] Steps 904a to 904b are the same as steps 804a to 804b above.

[0463] Steps 905 and 906 are the same as steps 805 and 806 above.

[0464] In step 907, the target AM PCF sends a subscription request message to the UDR. The UDR then receives the subscription request message.

[0465] Specifically, the target AM PCF, based on the received authorized AM policy or the received instruction information, determines not to immediately determine the authorized AM policy based on the terminal's subscription data. Instead, it sends a subscription request message to the UDR. This subscription request message contains the (S-NSSAI, DNN) combination and the external group identifier. This subscription request message is used to subscribe to AM-related application data, or can be understood as subscribing to AM influence information.

[0466] AM impact information can also be referred to as application layer information.

[0467] Optionally, the subscription request message can be a Nudr_DM_Subscribe request message.

[0468] In step 908, the UDR sends a notification message to the target AM PCF. The target AM PCF then receives this notification message.

[0469] This notification message contains AM impact information. Optionally, this notification message can be a Nudr_DM_Notifyrequest message.

[0470] In step 909, the target AM PCF sends an update request message to the UDR. The UDR then receives the update request message.

[0471] For the specific implementation of this step, please refer to step 607 above.

[0472] Steps 910 to 918 are the same as steps 811 to 819 above.

[0473] Step 919 is the same as step 821 above.

[0474] The beneficial effects of this embodiment can be referred to the foregoing. Figure 8 The beneficial effects of the embodiments will not be elaborated further.

[0475] Figure 10 The present application provides a communication method in which AMPCF subscribes to the above-mentioned events from SMF via AMF. In this way, the problems caused by AMPCF obtaining the SMPCF identifier and initiating event subscription to SMPCF can be avoided. For example, it can avoid the possibility that AMPCF may need to subscribe to SMPCF information from multiple BSF instances.

[0476] The method includes the following steps: Steps 1001 to 1006 are the same as steps 601 to 606 above.

[0477] In step 1007, the AM PCF sends an update request message to the AMF. The AMF then receives the update request message.

[0478] This update request message is an example of the first request message in step 501c above.

[0479] Specifically, after receiving application-layer information from the AF for deciding the AM policy, the AM PCF determines that it needs to determine the AM policy information based on the application-layer information, and therefore decides to send the aforementioned update request message to the AMF. Furthermore, the AMPCF determines, based on the received application-layer information, that it also needs to know the status of the PDU session or the application status. The PDU session status is either established or terminated, and the application status is either started or stopped.

[0480] The update request message contains event subscription information and a (DNN, S-NSSAI) combination. The update request message is used to request the AMF to subscribe to the event corresponding to the event subscription information from the SMF corresponding to the (DNN, S-NSSAI) combination. The event is the state of the terminal's PDU session or the state of the terminal's application.

[0481] The event subscription information includes event identification information. As one implementation method, if the AM policy authorization request message in step 1006 includes information 1 or information 2, the event identification information can be set to the state of the PDU session. If the AM policy authorization request message in step 1006 includes information 3 or information 4, the event identification information can be set to application detection (or application start / stop). Wherein, when the event identification information is application detection, the event subscription information also includes the identifier of at least one application.

[0482] Optionally, the event subscription information also includes a notification address, which is the AM PCF's address. After receiving the event subscription information, the AMF modifies the notification address in the event subscription information to the AMF's address.

[0483] As one implementation method, the event subscription information mentioned above can also include indication information, which is used to indicate the notification strategy. This notification strategy is as follows: for multiple PDU sessions controlled by the SMF corresponding to the same (DNN, S-NSSAI) combination, the AM PCF is notified when the first PDU session among these multiple PDU sessions is established, and when the last PDU session among these multiple PDU sessions terminates (or is released). That is, the AM PCF is notified when the first PDU session among these multiple PDU sessions is established; no notification is needed when other PDU sessions are established. If no active PDU session exists after the release of a PDU session among these multiple PDU sessions, the AM PCF is notified. If at least one active PDU session exists after the release of a PDU session among these multiple PDU sessions, the AM PCF is not notified.

[0484] As another implementation method, the AM policy authorization request message in step 1006 above includes either information 1 or information 2. The event corresponding to the event identifier information is the state of the PDU session. The state of the PDU session is either the establishment of the first session corresponding to the (DNN, S-NSSAI) combination, or the termination of the last session corresponding to the (DNN, S-NSSAI) combination. This can be understood as the event identifier information being used to indicate the detection of the establishment of the first session corresponding to the (DNN, S-NSSAI) combination and / or the termination of the last session corresponding to the (DNN, S-NSSAI) combination. Alternatively, it can be understood as the event identifier information being used to indicate that the AM PCF is notified when the first PDU session corresponding to a (DNN, S-NSSAI) combination is established and / or when the last PDU session corresponding to a (DNN, S-NSSAI) combination terminates. Therefore, when the AMF determines that the first PDU session corresponding to the (DNN, S-NSSAI) combination in the update request message of step 1007 has been established, the AMF can notify the AM PCF that the first PDU session has been established. When the AMF determines that the last PDU session corresponding to the (DNN, S-NSSAI) combination in the update request message of step 1007 has ended, the AMF can notify the AM PCF that the last PDU session has ended.

[0485] Optionally, the update request message can be an Npcf_AMPolicyControl_UpdateNotify message.

[0486] Step 1008: After receiving the above update request message, AMF determines whether the target PDU session has been established.

[0487] The target PDU session is the PDU session corresponding to the combination of (DNN, S-NSSAI).

[0488] If the target PDU session has already been established, proceed with step 1009.

[0489] If the target PDU session has not yet been established, proceed with steps 1010 to 1011.

[0490] Step 1009: The AMF sends a subscription request message to the SMF. The SMF then receives the subscription request message.

[0491] This SMF is an SMF that provides services for the target PDU session, or it can be understood as an SMF that corresponds to the combination of (DNN, S-NSSAI).

[0492] The subscription request message contains the aforementioned event subscription information.

[0493] Optionally, the subscription request message can be an Nsmf_EventExposure_Subscribe message.

[0494] In step 1010, the terminal sends a session establishment request message to the AMF. Correspondingly, the AMF receives the session establishment request message.

[0495] Optionally, the session establishment request message can be a PDU Session Establishment Request message.

[0496] Step 1011: The AMF sends a subscription request message to the SMF. The SMF then receives the subscription request message.

[0497] If AMF determines that it has received a session establishment request message, it will execute step 1011.

[0498] Step 1011 is the same as step 1009 above, and can be referred to the foregoing description.

[0499] Step 1012: SMF performs event detection based on the event subscription information.

[0500] If the event identifier information in the event subscription information indicates the state of the PDU session, then SMF detects the state of the PDU session. If the event identifier information in the event subscription information indicates application detection, then SMF detects whether the application is started or stopped.

[0501] Step 1013: The SMF sends a notification message to the AMF. The AMF then receives the notification message.

[0502] As one implementation method, if the event identifier information in the event subscription information is the state of the PDU session, then the notification message includes indication information indicating that the PDU session has been established. Optionally, when the update request message in step 1007 includes multiple (DNN, S-NSSAI) combinations, then the notification message also includes the (DNN, S-NSSAI) combination corresponding to the established PDU session.

[0503] As another implementation method, if the event identifier information in the event subscription information is application detection, and SMF detects the application start event corresponding to the application identifier, then the notification message includes indication information indicating that the application has started. Optionally, if the event subscription information includes identifiers of multiple applications, then the notification message also includes the identifier of the application that has started.

[0504] Optionally, the notification message can be an Nsmf_EventExposure_Notify message.

[0505] Step 1014: The AMF sends a notification message to the AM PCF. The AM PCF then receives the notification message.

[0506] As one implementation method, the content of this notification message is the same as that of the notification message in step 1013 above.

[0507] As another implementation method, if the event identification information in step 1007 is used to indicate the establishment of the first session corresponding to the detection (DNN, S-NSSAI) combination, and / or the termination of the last session corresponding to the (DNN, S-NSSAI) combination, or if the event identification information is used to indicate that AM PCF is notified when the first PDU session corresponding to a (DNN, S-NSSAI) combination is established and / or when AM PCF is notified when the last PDU session corresponding to a (DNN, S-NSSAI) combination is terminated, then the notification message contains indication information indicating the establishment of a PDU session, further indicating that the first PDU session corresponding to the (DNN, S-NSSAI) combination is established.

[0508] Optionally, the notification message can be an Npcf_AMPolicyControl_Update message.

[0509] Steps 1015 to 1020 are the same as steps 615 to 620 above.

[0510] Optionally, if the SMF determines that the state of the PDU session or the state of the application has changed, steps 1021 to 1028 may also be performed.

[0511] Step 1021: The SMF sends a notification message to the AMF. The AMF then receives the notification message.

[0512] As one implementation method, if the SMF detects the termination of a PDU session at a certain time, the notification message contains indication information indicating that the PDU session has been terminated or released.

[0513] As another implementation method, if SMF detects at a certain time that the application corresponding to the application's identifier has stopped, the notification message includes indication information indicating that the application has stopped. Optionally, if the event subscription information includes the identifiers of multiple applications, the notification message also includes the identifier of the stopped application.

[0514] Optionally, the notification message can be an Nsmf_EventExposure_Notify message.

[0515] Step 1022: The AMF sends a notification message to the AM PCF. The AM PCF then receives the notification message.

[0516] The content of this notification message is the same as that of the notification message in step 1021 above.

[0517] Optionally, the notification message can be an Npcf_AMPolicyControl_Update message.

[0518] Steps 1023 to 1028 are the same as steps 622 to 627 above.

[0519] According to the above scheme, the AM PCF obtains the state of the PDU session or application from the AMF, thereby triggering the AMPCF to update the AM policy based on the application layer information from the AF. In this scheme, the AM PCF does not need to subscribe to the binding information of the SM PCF from the BSF, which avoids the AM PCF subscribing to the binding information of the SM PCF from every BSF in the network without knowing the IP address of the terminal, thus reducing signaling overhead and resource waste.

[0520] Figure 10 (a) A communication method provided in the embodiments of this application, wherein the AMPCF subscribes to the above-mentioned events from the SMF via the AMF. In this way, the problems caused by the AMPCF obtaining the SMPCF identifier and initiating the event subscription to the SMPCF can be avoided. For example, the AMPCF may need to subscribe to the SMPCF information from multiple BSF instances.

[0521] The method includes the following steps: Steps 1001a to 1006a are the same as steps 601 to 606 above.

[0522] In step 1007a, the AM PCF sends an update request message to the AMF. The AMF then receives the update request message.

[0523] This update request message is an example of the first request message in step 501c above.

[0524] Specifically, after receiving application-layer information from the AF for deciding the AM policy, the AM PCF determines that it needs to determine the AM policy information based on the application-layer information, and therefore decides to send the aforementioned update request message to the AMF. Furthermore, the AMPCF determines, based on the received application-layer information, that it also needs to know the status of the PDU session, which is either established or terminated.

[0525] The update request message contains event subscription information and a (DNN, S-NSSAI) combination. This update request message is used to request AMF to subscribe to the event corresponding to the (DNN, S-NSSAI) combination and the event subscription information.

[0526] The event subscription information includes event identification information. As one implementation, if the AM policy authorization request message in step 1006a includes information 1 or information 2, the event identification information can be set as the state of the PDU session. For this implementation, the update request message is used to request subscription from the AMF to the state of the PDU session corresponding to the (DNN, S-NSSAI) combination.

[0527] As one implementation method, the event subscription information mentioned above can also include indication information, which is used to indicate the notification strategy. This notification strategy is as follows: for multiple PDU sessions corresponding to the same (DNN, S-NSSAI) combination, AM PCF is notified when the first PDU session among these multiple PDU sessions is established, and AM PCF is notified when the last PDU session among these multiple PDU sessions terminates (or is released). That is, AM PCF is notified when the first PDU session among these multiple PDU sessions is established; no notification is needed when other PDU sessions are established. AM PCF is notified when a PDU session among these multiple PDU sessions is released and there are no active PDU sessions. AM PCF is notified when at least one PDU session among these multiple PDU sessions remains active after the release of a PDU session among these multiple PDU sessions.

[0528] As another implementation method, if the AM policy authorization request message in step 1006a includes information 1 or information 2, and the event corresponding to the event identifier information is the state of the PDU session, and the state of the PDU session is the establishment of the first session corresponding to the (DNN, S-NSSAI) combination, or the termination of the last session corresponding to the (DNN, S-NSSAI) combination, it can be understood that the event identifier information is used to indicate the detection of the establishment of the first session corresponding to the (DNN, S-NSSAI) combination and / or the termination of the last session corresponding to the (DNN, S-NSSAI) combination. Alternatively, it can be understood that the event identifier information is used to indicate that the AM PCF is notified when the first PDU session corresponding to a (DNN, S-NSSAI) combination is established and / or when the last PDU session corresponding to a (DNN, S-NSSAI) combination is terminated. Therefore, when the AMF determines that the first PDU session corresponding to the (DNN, S-NSSAI) combination in the update request message of step 1007a has been established, the AMF can notify the AM PCF that the first PDU session has been established. When the AMF determines that the last PDU session corresponding to the (DNN, S-NSSAI) combination in the update request message of step 1007a has ended, the AMF can notify the AM PCF that the last PDU session has ended.

[0529] Optionally, the update request message can be an Npcf_AMPolicyControl_UpdateNotify message.

[0530] Step 1008a: The AMF sends a notification message to the AM PCF. The AM PCF then receives the notification message.

[0531] As one implementation method, if the event identifier information in step 1007a is the status of the PDU session, when the AMF determines that the PDU session corresponding to the (DNN, S-NSSAI) combination has been established, then step 1008a is executed, and the notification message of step 1008a contains indication information indicating that the PDU session has been established. Optionally, when the update request message of step 1007a includes multiple (DNN, S-NSSAI) combinations, then the notification message of step 1008a also includes the (DNN, S-NSSAI) combination corresponding to the established PDU session.

[0532] As another implementation method, if the event subscription information in step 1007a contains indication information, the indication information is used to indicate the notification strategy. The notification strategy is as follows: for multiple PDU sessions controlled by SMF corresponding to the same (DNN, S-NSSAI) combination, when the first PDU session among the multiple PDU sessions is established, AM PCF is notified, and when the last PDU session among the multiple PDU sessions is terminated (or released), AM PCF is notified. When AMF determines that the PDU session corresponding to the (DNN, S-NSSAI) combination has been established, step 1008a is executed. The notification message of step 1008a contains indication information, which indicates that the PDU session has been established, and further indicates that the first PDU session corresponding to the (DNN, S-NSSAI) combination has been established.

[0533] As another implementation method, if the event identification information in step 1007a is used to indicate the establishment of the first session corresponding to the (DNN, S-NSSAI) combination and / or the termination of the last session corresponding to the (DNN, S-NSSAI) combination, or if the event identification information is used to indicate that the AM PCF is notified when the first PDU session corresponding to a (DNN, S-NSSAI) combination is established and / or when the AM PCF is notified when the last PDU session corresponding to a (DNN, S-NSSAI) combination is terminated, and the AMF determines that the PDU session corresponding to the (DNN, S-NSSAI) combination has been established, then step 1008a is executed, and the notification message of step 1008a contains indication information, which indicates that the PDU session is established, further indicating that the first PDU session corresponding to the (DNN, S-NSSAI) combination is established.

[0534] Optionally, the notification message for step 1008a can be an Npcf_AMPolicyControl_Update message.

[0535] As one implementation method, before step 1008a, the terminal establishes the PDU session corresponding to the (DNN, S-NSSAI) combination through interaction with network-side network elements (including AMF). Therefore, AMF can determine (or detect) that the PDU session corresponding to the (DNN, S-NSSAI) combination has been established based on the context of the saved PDU session.

[0536] Steps 1009a to 1014a are the same as steps 615 to 620 above.

[0537] Optionally, if the AMF determines that the state of the PDU session has changed, steps 1015a to 1021a may also be performed.

[0538] In step 1015a, the AMF sends a notification message to the AM PCF. The AM PCF then receives the notification message.

[0539] At a certain point, if the AMF determines that the PDU session has terminated, it can execute step 1015a. For example, the AMF may receive a PDU session termination / release request message from the terminal, and the AMF can determine the termination of the PDU session based on this message. Alternatively, the AMF may receive a notification message from the SMF indicating that the PDU session has terminated, and the AMF can determine the termination of the PDU session based on this notification message.

[0540] As one implementation method, if the event identification information in step 1007a is the state of a PDU session, then the notification message in step 1015a includes indication information indicating the termination of the PDU session. Optionally, when the update request message in step 1007a includes multiple (DNN, S-NSSAI) combinations, then the notification message in step 1015a also includes the (DNN, S-NSSAI) combination corresponding to the established PDU session.

[0541] As another implementation method, if the event subscription information in step 1007a contains indication information, which is used to indicate the notification strategy, the notification strategy is as follows: for multiple PDU sessions controlled by SMF corresponding to the same (DNN, S-NSSAI) combination, when the first PDU session among the multiple PDU sessions is established, the AM PCF is notified, and when the last PDU session among the multiple PDU sessions is terminated (or released), the AM PCF is notified, then the notification message in step 1015a contains indication information, which indicates the termination of the PDU session, and further indicates that the first PDU session corresponding to the (DNN, S-NSSAI) combination is established.

[0542] As another implementation method, if the event identification information in step 1007a is used to indicate the establishment of the first session corresponding to the detection (DNN, S-NSSAI) combination, and / or the termination of the last session corresponding to the (DNN, S-NSSAI) combination, or if the event identification information is used to indicate that AM PCF is notified when the first PDU session corresponding to a (DNN, S-NSSAI) combination is established and / or when AM PCF is notified when the last PDU session corresponding to a (DNN, S-NSSAI) combination is terminated, then the notification message in step 1015a contains indication information indicating the termination of the PDU session, and further indicating the termination of the last PDU corresponding to the (DNN, S-NSSAI) combination.

[0543] Optionally, the notification message for step 1015a can be an Npcf_AMPolicyControl_Update message.

[0544] Steps 1016a to 1021a are the same as steps 622 to 627 above.

[0545] According to the above scheme, the AM PCF obtains the PDU session status from the AMF, thereby triggering the AM PCF to update the AM policy based on application layer information from the AF. In this scheme, the AM PCF does not need to subscribe to the SM PCF binding information from the BSF, which avoids the AM PCF subscribing to the SM PCF binding information from every BSF in the network without knowing the terminal's IP address, thus reducing signaling overhead and resource waste.

[0546] It is understood that, in order to achieve the functions in the above embodiments, the AF and the base station include hardware structures and / or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and method steps of the various examples described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0547] Figure 11 and Figure 12 The diagram illustrates the possible communication devices provided in the embodiments of this application. These communication devices can be used to implement the functions of the first PCF, second PCF, UDR, AMF, or SMF in the above method embodiments, and thus also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be the first PCF, second PCF, UDR, AMF, or SMF, or it can be a module (such as a chip) applied to the first PCF, second PCF, UDR, AMF, or SMF.

[0548] like Figure 11 As shown, the communication device 1100 includes a processing unit 1110 and a transceiver unit 1120. The communication device 1100 is used to implement the above-described figures 5(a), 5(b), and 5(c). Figures 6 to 10 , Figure 10 (a) shows the function of the first PCF, second PCF, UDR, AMF or SMF in the method embodiment.

[0549] When the communication device 1100 is used to implement Figure 5(a), Figure 6 or Figure 7 In the method embodiment shown, the first PCF functions as follows: A transceiver unit 1120 sends a request message to a data management network element. This request message includes the terminal's identification information, event identification information, and a notification address. The event identification information indicates the state of the detected session or the state of the application. The notification address is the address of a first policy control network element used to receive event notifications corresponding to the event identification information. The request message requests the data management network element to save the event identification information and the notification address. It also receives a notification message from a second policy control network element. This notification message includes the state of the terminal's session or the state of the terminal's application. The state of the terminal's session or the state of the terminal's application is detected based on the event identification information obtained from the data management network element. A processing unit 1110 determines a mobility management policy based on the state of the terminal's session or the state of the terminal's application. The first policy control network element is used to formulate a mobility management policy, and the second policy control network element is used to formulate a session management policy.

[0550] As one possible implementation, the processing unit 1110 is specifically used to determine the mobility management policy based on application layer information from the application function network element when the state of the terminal's session is session established or the state of the terminal's application is application started.

[0551] As one possible implementation, the transceiver unit 1120 is also configured to receive a response message from the data management network element. The response message includes first identification information, which is the identification information of the event identification information and the notification address. The first identification information is used to modify or delete the event identification information and / or the notification address.

[0552] As one possible implementation, the transceiver unit 1120 is also used to send the mobility management policy to the application function network element.

[0553] As one possible implementation, the transceiver unit 1120 is further configured to receive third indication information from a mobility management network element, the third indication information being used to indicate that the mobility management policy used by the terminal is determined based on application layer information; the first policy control network element determines the mobility management policy with a delay based on the third indication information; wherein, the first policy control network element is a policy control network element that provides services to the terminal after the terminal moves.

[0554] When the communication device 1100 is used to implement Figure 5(a), Figure 6 or Figure 7 In the method embodiment shown, the function of the second PCF is as follows: Transceiver unit 1120 is used to receive event identification information and a notification address from a data management network element. The event identification information is used to indicate the state of the detected session or the state of the application. The notification address is the address of a first policy control network element used to receive event notifications corresponding to the event identification information. Processing unit 1110 is used to detect the state of the terminal's session or the state of the terminal's application based on the event identification information. Transceiver unit 1120 is also used to send a notification message to the first policy control network element based on the notification address. The notification message contains the state of the terminal's session or the state of the terminal's application. The first policy control network element is used to formulate mobility management policies, and the second policy control network element is used to formulate session management policies.

[0555] As one possible implementation, the transceiver unit 1120 is used to send a query request message to the data management network element, the query request message being used to request a query of the terminal's subscription data; the second policy control network element receives a query response message from the data management network element, the query response message including the terminal's subscription data, the subscription data including the event identification information and the notification address.

[0556] As one possible implementation, the transceiver unit 1120 is configured to send a subscription data request message to the data management network element, the subscription data request message being used to request notification of changes to the terminal's subscription data; and to receive a notification message from the data management network element, the notification message including the terminal's changed subscription data, the changed subscription data including the event identifier information and the notification address.

[0557] When the communication device 1100 is used to implement Figure 5(a), Figure 6 or Figure 7 In the method embodiment shown, the UDR function is as follows: the transceiver unit 1120 is used to receive a request message from a first policy control network element. The request message contains terminal identification information, event identification information, and a notification address. The event identification information is used to indicate the state of the detection session or the state of the application. The notification address is the address of the first policy control network element used to receive the event notification corresponding to the event identification information. The request message is used to request the data management network element to save the event identification information and the notification address. It also sends the event identification information and the notification address to a second policy control network element. The first policy control network element is used to formulate mobility management policies, and the second policy control network element is used to formulate session management policies.

[0558] As one possible implementation, the transceiver unit 1120 is configured to receive a query request message from the second policy control network element, the query request message being used to request a query of the terminal's subscription data; and to send a query response message to the second policy control network element, the query response message including the terminal's subscription data, the subscription data including the event identification information and the notification address.

[0559] As one possible implementation, the transceiver unit 1120 is configured to receive a subscription data request message from the second policy control network element, the subscription data request message being used to request notification of changes to the terminal's subscription data; and to send a notification message to the second policy control network element, the notification message including the terminal's changed subscription data, the changed subscription data including the event identifier information and the notification address.

[0560] As one possible implementation, the transceiver unit 1120 is used to send a response message to the first policy control network element. The response message includes first identification information, which is the identification information of the event identification information and the notification address. The first identification information is used to modify or delete the event identification information and / or the notification address.

[0561] When the communication device 1100 is used to implement Figure 5(b), Figure 8 or Figure 9 In the method embodiment shown, the first PCF functions as follows: Transceiver unit 1120 is used to send a request message to a data management network element. This request message includes first identification information and a first notification address. The first identification information is event identification information and a second notification address identifier stored by the data management network element. The event identification information is used to indicate the state of the detection session or the application. The first notification address is the address of a first policy control network element used to receive event notifications corresponding to the event identification information. The second notification address is the address of a third policy control network element used to receive event notifications corresponding to the event identification information. The request message is used to request the data management network element to update the second notification address to the first notification address; and to receive incoming... The notification message from the second policy control network element contains the state of the terminal's session or the state of the terminal's application. The state of the terminal's session or the state of the terminal's application is detected based on the event identification information obtained from the data management network element. The processing unit 1110 is used to determine a mobility management policy based on the state of the terminal's session or the state of the terminal's application. The first policy control network element and the third policy control network element are used to formulate a mobility management policy. The second policy control network element is used to formulate a session management policy. The first policy control network element is the policy control network element that provides services to the terminal after the terminal moves, and the third policy control network element is the policy control network element that provides services to the terminal before the terminal moves.

[0562] When the communication device 1100 is used to implement Figure 5(c), Figure 10 or Figure 10 In the method embodiment shown in (a), the first PCF functions as follows: Transceiver unit 1120 is configured to send a first request message to a mobility management network element, the first request message containing event identification information, the event identification information being used to indicate the state of the terminal's session or the state of the terminal's application, the first request message being used to request an event notification corresponding to the event identification information; and to receive a notification message from the mobility management network element or the session management network element corresponding to the session, the notification message containing the state of the terminal's session or the state of the terminal's application, the state of the terminal's session or the state of the terminal's application being detected based on the event identification information; processing unit 1110 is configured to determine a mobility management policy based on the state of the terminal's session or the state of the terminal's application; wherein, the first policy control network element is used to formulate a mobility management policy.

[0563] As one possible implementation, the processing unit 1110 is specifically used to determine the mobility management policy based on the application layer information from the application function network element when the state of the session is session established or the state of the application is application started.

[0564] As one possible implementation, the transceiver unit 1120 is used to send the mobility management policy to the application function network element.

[0565] When the communication device 1100 is used to implement Figure 5(c) or Figure 10 In the method embodiment shown, the SMF functions as follows: Transceiver unit 1120 is configured to receive a second request message from a mobility management network element. The second request message contains event identification information, which indicates the state of the terminal's session or the state of the terminal's application. The second request message requests an event notification corresponding to the event identification information. Processing unit 1110 is configured to detect the state of the terminal's session or the state of the terminal's application based on the event identification information. Transceiver unit 1120 is further configured to send a notification message to the mobility management network element or the first policy control network element corresponding to the terminal. The notification message contains the state of the terminal's session or the state of the terminal's application. The first policy control network element is a policy control network element used to formulate mobility management policies.

[0566] When the communication device 1100 is used to implement Figure 5(c), Figure 10 or Figure 10 In the method embodiment shown in (a), the AMF functions as follows: the transceiver unit 1120 is configured to receive a first request message from a first policy control network element, the first request message containing event identification information, the event identification information being used to indicate the state of the terminal's session or the state of the terminal's application, the first request message being used to request an event notification corresponding to the event identification information; and, after the processing unit 1110 detects an event corresponding to the event identification information, it sends a notification message to the first policy control network element, the notification message containing the state of the terminal's session or the state of the terminal's application, the state of the terminal's session or the state of the terminal's application being detected based on the event identification information; the processing unit 1110 is configured to detect the event corresponding to the event identification information, wherein the first policy control network element is used to formulate a mobility management policy.

[0567] As one possible implementation, the transceiver unit 1120 is used to send the notification message to the first policy control network element after the processing unit 1110 detects that a session corresponding to the (DNN, S-NSSAI) combination of the terminal has been established. The notification message contains the status of the session, which is that the session has been established.

[0568] As one possible implementation, the transceiver unit 1120 is used to send the first notification message to the first policy control network element after the processing unit 1110 detects that the session corresponding to the (DNN, S-NSSAI) combination of the terminal has ended. The first notification message contains the status of the session, which is that the session has ended.

[0569] As one possible implementation, the transceiver unit 1120 is used to send the first notification message to the first policy control network element after the processing unit 1110 detects that the first session corresponding to the (DNN, S-NSSAI) combination of the terminal has been established. The first notification message contains the status of the session, and the status of the session is that the session has been established.

[0570] As one possible implementation, the transceiver unit 1120 is used to send the first notification message to the first policy control network element after the processing unit 1110 detects that the last session corresponding to the (DNN, S-NSSAI) combination of the terminal has ended. The first notification message contains the status of the session, and the status of the session is session termination.

[0571] As one possible implementation, the transceiver unit 1120 is configured to send a second request message to the session management network element, the second request message containing the event identification information, the second request message being used to request the event notification corresponding to the event identification information; receive a notification message from the session management network element, the notification message containing the application status of the terminal or the session status of the terminal; and send the notification message to the first policy control network element, the notification message containing the application status of the terminal or the session status of the terminal.

[0572] For a more detailed description of the processing unit 1110 and the transceiver unit 1120, please refer directly to Figures 5(a), 5(b), and 5(c). Figures 6 to 10 The relevant descriptions in the method embodiments shown are directly obtained and will not be repeated here.

[0573] like Figure 12 As shown, the communication device 1200 includes a processor 1210 and an interface circuit 1220. The processor 1210 and the interface circuit 1220 are coupled to each other. It is understood that the interface circuit 1220 can be a transceiver or an input / output interface. Optionally, the communication device 1200 may also include a memory 1230 for storing instructions executed by the processor 1210, or storing input data required by the processor 1210 to execute instructions, or storing data generated after the processor 1210 executes instructions.

[0574] When the communication device 1200 is used to implement Figures 5(a), 5(b), and 5(c), Figures 6 to 10 In the method shown, processor 1210 is used to implement the functions of the processing unit 1110, and interface circuit 1220 is used to implement the functions of the transceiver unit 1120.

[0575] It is understood that the processor in the embodiments of this application may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor may be a microprocessor or any conventional processor.

[0576] The method steps in the embodiments of this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a base station or terminal. Of course, the processor and storage medium can also exist as discrete components in the base station or terminal.

[0577] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a base station, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. 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 integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0578] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0579] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates an "or" relationship between the preceding and following related objects; in the formulas of this application, the character " / " indicates a "division" relationship between the preceding and following related objects.

[0580] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.< / apiversion> < / apiversion>

Claims

1. A communication method, characterized in that, The method is applied to the first policy control network element, including: A request message is sent to the data management network element. The request message contains the terminal's identification information, event identification information, and notification address. The event identification information is used to indicate the state of the detection session or the state of the application. The notification address is the address of the first policy control network element that receives the event notification corresponding to the event identification information. The system receives a notification message from a second policy control network element, which is used to formulate a session management policy. The notification message contains the session status of the terminal or the application status of the terminal. The session status of the terminal or the application status of the terminal is detected based on the event identification information. Mobility management policies are determined based on the state of the terminal's session or the state of the terminal's application.

2. The method according to claim 1, characterized in that, The step of determining the mobility management policy based on the session state of the terminal or the application state of the terminal includes: When the terminal's session is in the state of session establishment or the terminal's application is in the state of application start, the mobility management policy is determined based on application layer information from the application function network element.

3. The method according to claim 2, characterized in that, The application layer information includes a combination of (Data Network Name DNN, Single Network Slice Selection Auxiliary Information S-NSSAI), and the request message also includes the (DNN, S-NSSAI) combination. The second policy control network element corresponds to the (DNN, S-NSSAI) combination.

4. The method according to claim 3, characterized in that, The request message also includes first indication information, which is used to indicate a notification strategy. The notification strategy is to send the notification message when the first session corresponding to the (DNN, S-NSSAI) combination is established, and / or to send the notification message when the last session corresponding to the (DNN, S-NSSAI) combination is terminated.

5. The method according to any one of claims 2-4, characterized in that, The mobility management policy includes second indication information, which indicates that the mobility management policy is determined based on the application layer information.

6. The method according to any one of claims 1-5, characterized in that, The first policy control network element receives a response message from the data management network element. The response message includes first identification information, which is the identification information of the event identification information and / or the notification address. The first identification information is used to modify or delete the event identification information and / or the notification address.

7. The method according to any one of claims 1-6, characterized in that, The first policy control network element sends the mobility management policy to the application function network element.

8. The method according to any one of claims 1-7, characterized in that, The method is applied to a first policy control network element, which is a policy control network element that provides services to the terminal after the terminal moves. The method further includes: The terminal receives a third indication information from a mobility management network element, the third indication information being used to indicate that the mobility management policy used by the terminal is determined based on application layer information; Based on the third indication information, the mobility management strategy is delayed.

9. A communication method, characterized in that, The method is applied to the second policy control network element, including: Receive event identification information and notification address from data management network element. The event identification information is used to indicate the status of the detection session or the status of the application. The notification address is the address of the first policy control network element used to receive the event notification corresponding to the event identification information. Based on the event identifier information, detect the state of the terminal's session or the state of the terminal's application; According to the notification address, a notification message is sent to the first policy control network element, and the notification message contains the session status of the terminal or the application status of the terminal. The first policy control network element is used to formulate mobility management policies, and the second policy control network element is used to formulate session management policies.

10. The method according to claim 9, characterized in that, The receipt of event identification information and notification address from the data management network element includes: Send a query request message to the data management network element, the query request message being used to request a query of the terminal's subscription data; The system receives a query response message from the data management network element. The query response message includes the terminal's subscription data, which contains the event identifier information and the notification address.

11. The method according to claim 10, characterized in that, The query request message also includes a (DNN, S-NSSAI) combination, the second policy control network element corresponds to the (DNN, S-NSSAI) combination, and the query request message is used to request the query of the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination.

12. The method according to claim 9, characterized in that, The receipt of event identification information and notification address from the data management network element includes: Send a subscription data request message to the data management network element. The subscription data request message is used to request notification of changes to the terminal's subscription data. The terminal receives a notification message from the data management network element. The notification message includes the terminal's modified subscription data, which contains the event identifier information and the notification address.

13. The method according to claim 12, characterized in that, The subscription data request message also includes a (DNN, S-NSSAI) combination, the second policy control network element corresponds to the (DNN, S-NSSAI) combination, and the subscription data request is used to request the terminal to receive a notification of a change in the subscription data corresponding to the (DNN, S-NSSAI) combination.

14. A communication method, characterized in that, The method is applied to data management network elements, including: A request message is received from a first policy control network element. The request message contains the terminal's identification information, event identification information, and notification address. The event identification information is used to indicate the state of the detection session or the state of the application. The notification address is the address of the first policy control network element that receives the event notification corresponding to the event identification information. The event identification information and the notification address are sent to the second policy control network element. The first policy control network element is used to formulate mobility management policies, and the second policy control network element is used to formulate session management policies.

15. The method according to claim 14, characterized in that, Sending the event identifier information and the notification address to the second policy control network element includes: Receive a query request message from the second policy control network element, the query request message being used to request a query of the terminal's subscription data; A query response message is sent to the second policy control network element. The query response message includes the terminal's subscription data, which contains the event identifier information and the notification address.

16. The method according to claim 15, characterized in that, The query request message also includes a (DNN, S-NSSAI) combination, the second policy control network element corresponds to the (DNN, S-NSSAI) combination, and the query request message is used to request the query of the terminal's subscription data corresponding to the (DNN, S-NSSAI) combination.

17. The method according to claim 14, characterized in that, Sending the event identifier information and the notification address to the second policy control network element includes: Receive a subscription data request message from the second policy control network element, the subscription data request message being used to request notification of changes to the terminal's subscription data; A notification message is sent to the second policy control network element. The notification message includes the terminal's modified subscription data, and the modified subscription data includes the event identifier information and the notification address.

18. The method according to claim 17, characterized in that, The subscription data request message also includes a (DNN, S-NSSAI) combination, the second policy control network element corresponds to the (DNN, S-NSSAI) combination, and the subscription data request is used to request the terminal to receive a notification of a change in the subscription data corresponding to the (DNN, S-NSSAI) combination.

19. The method according to any one of claims 14-18, characterized in that, The method further includes: A response message is sent to the first policy control network element. The response message includes first identification information, which is the identification information of the event identification information and / or the notification address. The first identification information is used to modify or delete the event identification information and / or the notification address.

20. A communication method, characterized in that, The method is applied to the first policy control network element, including: A request message is sent to a data management network element. The request message contains first identification information and a first notification address. The first identification information is the event identification information and the identification information of the second notification address stored by the data management network element. The event identification information is used to indicate the status of the detection session or the status of the application. The first notification address is the address of the first policy control network element used to receive the event notification corresponding to the event identification information. The second notification address is the address of the third policy control network element used to receive the event notification corresponding to the event identification information. The request message is used to request the data management network element to update the second notification address to the first notification address. Receive a notification message from the second policy control network element. The notification message contains the state of the terminal's session or the state of the terminal's application. The state of the terminal's session or the state of the terminal's application is detected based on the event identification information obtained from the data management network element. The mobility management strategy is determined based on the state of the terminal's session or the state of the terminal's application. The first policy control network element and the third policy control network element are used to formulate mobility management policies, the second policy control network element is used to formulate session management policies, the first policy control network element is the policy control network element that provides services to the terminal after the terminal moves, and the third policy control network element is the policy control network element that provides services to the terminal before the terminal moves.

21. The method according to any one of claims 1-13, 17, 18 or 20, characterized in that, The notification message also includes at least one of the terminal's session identifier, the terminal's address, or the identifier of the second policy control network element.

22. A communication method, characterized in that, The method is applied to session management network elements, including: The system receives a second request message from a mobility management network element. The second request message contains event identification information, which is used to indicate the state of the terminal's session or the state of the terminal's application. The second request message is used to request the event notification corresponding to the event identification information. Based on the event identifier information, detect the state of the terminal's session or the state of the terminal's application; A notification message is sent to the mobility management network element or the first policy control network element corresponding to the terminal. The notification message contains the session status of the terminal or the application status of the terminal. The first policy control network element is a policy control network element used to formulate mobility management policies.

23. The method according to claim 22, characterized in that, The second request message also includes a (DNN, S-NSSAI) combination, and the second request message is used to request the state of the session or application of the terminal corresponding to the (DNN, S-NSSAI) combination.

24. The method according to claim 23, characterized in that, The second request message also includes first indication information, which is used to indicate a notification strategy. The notification strategy is to send the notification message when the first session corresponding to the (DNN, S-NSSAI) combination is established, and / or when the last session corresponding to the (DNN, S-NSSAI) combination is terminated.

25. A communication device, characterized in that, Includes modules for performing the method as described in any one of claims 1-24.

26. A communication device, characterized in that, It includes at least one processor, which is configured to invoke a program stored in memory to perform the method as described in any one of claims 1-24.

27. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a communication device, cause the method as described in any one of claims 1-24 to be performed.

28. A computer program product, characterized in that, The computer program product includes a computer program or instructions that, when executed by a communication device, cause the method as described in any one of claims 1-24 to be performed.

29. A communication system, characterized in that, It includes a first policy control network element and a second policy control network element, wherein: The first strategy control network element is used to execute the method as described in any one of claims 1-8; The second strategy control network element is used to perform the method as described in any one of claims 9-14.

30. The system according to claim 29, characterized in that, The system further includes a data management network element, which is used to perform the method as described in any one of claims 14-19.

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