Communication method and apparatus, storage medium, program product, chip, and chip system

Abstract

Embodiments of the present application disclose a communication method, a communication apparatus, a storage medium, a program product, a chip, and a chip system, which are used to reduce calls to a terminal device while ensuring successful information transmission, thereby avoiding transmission resource wastage and reducing the power consumption of the terminal device. An embodiment of the present application provides a communication method applied to an application function device, the method comprising: receiving a first message from a management function device, the first message being used to indicate a reachability status of a first terminal device; and, when the first message indicates that the first terminal device is unreachable, sending first information to the management function device, the first information being used by the first terminal device to determine whether to access a network.

Description

Communication methods and devices, storage media, software products, chips and chip systems

[0001] This application claims priority to Chinese Patent Application No. 202411445998.6, filed on October 15, 2024, entitled "Communication Method and Apparatus, Storage Medium, Program Product, Chip and Chip System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, specifically to communication methods and devices, storage media, software products, chips, and chip systems. Background Technology

[0003] The Internet Protocol Multimedia Subsystem (IMS) can implement IMS voice services. The IMS voice call process is as follows:

[0004] The calling party, User Equipment (UE) 1, completes registration and establishes a user plane connection. Similarly, the called party, UE2, also completes registration and establishes a user plane connection. When the calling party, UE1, generates first information, it needs to transmit this first information to the called party, UE2. However, in satellite communication, channel conditions are not stable, or in other locations with poor channel conditions, such as basements or elevators, i.e., when the called party, UE2, has poor channel conditions, it needs to move to a location with better channel conditions before restoring the user plane connection. This may result in wasted transmission resources and increased power consumption of the terminal equipment. Summary of the Invention

[0005] This application provides communication methods and devices, storage media, program products, chips and chip systems, which reduce calls to terminal devices while ensuring successful information transmission, thereby avoiding waste of transmission resources and reducing the power consumption of terminal devices.

[0006] To address the aforementioned technical problems, this application provides the following technical solutions:

[0007] In a first aspect, embodiments of this application provide a communication method, characterized in that the method is applied to an application function device, which may be a communication device (such as a network device), and includes not only the communication device itself, but also some components within the communication device (e.g., circuits or chips responsible for communication functions (such as modem chips, also known as baseband chips, or system-on-chip (SoC) chips containing modem cores or system-in-package (SIP) chips), or may be logic modules or software capable of implementing all or part of the functions of the communication device. The method includes: receiving a first message from a management function device, the first message indicating the reachability status of a first terminal device; and, if the first message indicates that the first terminal device is unreachable, sending first information to the management function device, wherein the first information is used by the first terminal device to determine whether to access the network.

[0008] In the above scheme, the management function device sends a first message to the application function device, the first message indicating the reachability status of the first terminal device. If the first message indicates that the first terminal device is unreachable, the application function device sends a first information to the management function device. The first terminal device can determine whether to access the network based on the first information. Therefore, the first terminal device can determine whether to restore the user plane connection. While ensuring the successful transmission of the first information, calls to the terminal device are reduced, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0009] In one possible implementation of the first aspect, the method further includes: sending a first subscription message to a management function device, the first subscription message being used to subscribe to the reachability status of a first terminal device. In the above scheme, the application function device can subscribe to the reachability status of the first terminal device. For example, the application function device sends a first subscription message to the management function device, the management function device can receive the first subscription message, and the management function device sends a first message to the application function device based on the first subscription message, thereby enabling the management function device to indicate the reachability status of the first terminal device to the application function device.

[0010] In one possible implementation of the first aspect, sending the first subscription message to the management function device includes:

[0011] The first subscription message is sent to the management function device according to the second information; the second information includes at least one of the following: target service type, target service identifier, target sender, or target access network type.

[0012] In the above scheme, the application function device can determine whether to send the first subscription message based on the second information. The second information can be described as a service requirement, such as including at least one of the following: target service type, target service identifier, target sender information, and target access network type. The application function device sends the first subscription message only if the second information is satisfied; otherwise, it does not send the first subscription message. Therefore, in this embodiment, the reachability status of the first terminal device for services that satisfy the second information can be achieved, thus realizing highly reliable transmission for services that satisfy the second information.

[0013] In one possible implementation of the first aspect, sending the first subscription message to the management function device based on the second information includes:

[0014] The first subscription message is sent to the management function device according to the configuration information of the application function device. The configuration information of the application function device is used to indicate at least one of the following: the service served by the application function device is a target service type, the service served by the application function device is a target service identifier, the terminal device served by the application function device is a target sender, or the service served by the application function device accesses the network through a target access network type.

[0015] In the above scheme, the configuration information of the application function device can indicate whether to send a first subscription message to the management function device. When the configuration information indicates that the service served by the application function device is the target service, the application function device sends a first subscription message to the management function device. When the first terminal device is unreachable, the application function device sends a first message to the management function device. The paging message sent by the management function device to the first terminal device contains the first message. The first terminal device determines whether to access the network based on the obtained first message, and determines whether to restore the user plane connection, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0016] In one possible implementation of the first aspect, the first subscription message includes at least one of the following: target service type, target service identifier, target sender, or target access network type.

[0017] In the above scheme, the management function device can receive the first subscription message from the application function device. The management function device can also obtain at least one of the following from the first subscription message: target service type, target service identifier, target sender, or target access network type. Based on the matching of the target service type, target service identifier, target sender, or target access network type with the service corresponding to the downlink data, the number of times the management function device sends the reachability status is reduced, thus saving the signaling overhead of the management function device.

[0018] In one possible implementation of the first aspect, sending the first subscription message to the management function device based on the configuration information of the application function device includes:

[0019] Before the application function device receives or sends the target service, the first subscription message is sent to the management function device according to the configuration information of the application function device.

[0020] In the above scheme, the application function device can send a first subscription message to the management function device according to the configuration information of the application function device before receiving or sending the target service. It is not necessary to determine whether to send the first subscription message to the management function device based on the target service to be received or sent, which simplifies the way the application function device sends the first subscription message.

[0021] In one possible implementation of the first aspect, the first message is used to indicate the reachability state of the first terminal device, including: the first message is used to indicate that the first terminal device is in an idle state, or to indicate that the first terminal device enters an idle state.

[0022] In the above scheme, the management function device can determine the reachability status of the first terminal device based on the context of the first terminal device. The management function device can determine that the first terminal device is in an idle state or that the management function device has entered an idle state. Based on whether the first terminal device is in an idle state or has entered an idle state, the management function device generates a first message and sends the first message to the application function device so that the application function device can determine that the first terminal device is unreachable based on the first message.

[0023] In one possible implementation of the first aspect, the first message includes a first field indicating the reachability status of the first terminal device.

[0024] In the above scheme, the management function device can generate a first message based on the reachability status of the first terminal device. This first message includes a first field. The management function device sends the first message, also including the first field, to the application function device. The application function device determines the reachability status of the first terminal device based on the indication of the first field. In this embodiment, the first field included in the first message enables the management function device to indicate the reachability status of the first terminal device to the application function device.

[0025] In one possible implementation of the first aspect, sending the first information to the management function device includes:

[0026] Send a service information notification message to the management function device, the service information notification message including the first information.

[0027] In the above scheme, the application function device can interact with the management function device. The application function device generates a business information notification message, which carries the first information. The application function device sends the business information notification message to the management function device, so that the management function device, upon receiving the business information notification message, parses it to obtain the first information. This application embodiment does not limit the specific method by which the application function device sends the first information; existing signaling between the application function device and the management function device, or newly defined signaling, can be used to carry the first information.

[0028] In one possible implementation of the first aspect, the first information includes at least one of the following: service type, service identifier, or sender. In the above scheme, the first information can be used to represent a service. Specifically, the first information can be at least one of service type, service identifier, or sender. This first information can be sent from the application function device to the management function device, so that the management function device receives the first information, thereby enabling the management function device to obtain at least one of the following: service type, service identifier, or sender.

[0029] In one possible implementation of the first aspect, the first information is included in a paging message sent by the management function device to the first terminal device.

[0030] In the above scheme, the application function device can send first information, which the management function device can receive. After receiving the first information, the management function device sends a paging message to the first terminal device. The paging message includes the first information, so that the paged first terminal device can determine whether to access the network based on the first information, and determine whether to restore the user plane connection, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0031] Secondly, embodiments of this application also provide a communication method, which is applied to a management function device. The management function device can be a communication device (such as a network device), and includes not only the communication device itself, but also some components within the communication device (e.g., circuits or chips responsible for communication functions (such as modem chips, also known as baseband chips, or system-on-a-chip or system-in-package chips containing modem cores)). Alternatively, it can be a logic module or software capable of implementing all or part of the communication device's functions. The method includes:

[0032] Send a first message to the application function device, the first message being used to indicate the reachability status of the first terminal device;

[0033] The first terminal device receives first information sent by the application function device, wherein the first information is used to determine whether to access the network.

[0034] In the above scheme, the management function device sends a first message to the application function device, the first message indicating the reachability status of the first terminal device. If the first message indicates that the first terminal device is unreachable, the application function device sends a first information to the management function device. The first terminal device can determine whether to access the network based on the first information. Therefore, the first terminal device can determine whether to restore the user plane connection. While ensuring the successful transmission of the first information, calls to the terminal device are reduced, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0035] In one possible implementation of the second aspect, the method further includes:

[0036] Receive a first subscription message sent by the application function device, wherein the first subscription message is used to subscribe to the reachability status of the first terminal device.

[0037] In the above scheme, the application function device can subscribe to the reachability status of the first terminal device. For example, the application function device sends a first subscription message to the management function device, the management function device can receive the first subscription message, and the management function device sends a first message to the application function device according to the first subscription message, thereby enabling the management function device to indicate the reachability status of the first terminal device to the application function device.

[0038] In one possible implementation of the second aspect, sending the first message to the application function device includes:

[0039] Whether to allow the first terminal device to use the target service is determined based on third information, wherein the third information includes at least one of the following: the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device;

[0040] If the first terminal device is allowed to use the target service, the first message is sent to the application function device.

[0041] In the above scheme, the management function device determines whether to allow the first terminal device to use the target service based on third information. This third information can be implemented in various ways, including at least one of the following: the first terminal device's subscription information, the policy information of the policy control device, or the configuration information of the management function device. If the first terminal device is allowed to use the target service, the management function device can send a first message to the application function device, thus reducing the number of times the management function device sends reachability status messages and saving signaling overhead.

[0042] In one possible implementation of the second aspect, the first subscription message includes at least one of the following: target service type, target service identifier, target sender information, or target access network type;

[0043] Sending the first message to the application function device includes:

[0044] Receive a downlink data notification message from a user function device, the downlink data notification message being used to indicate that downlink data has arrived, the downlink data being the data sent to the first terminal device;

[0045] Determine whether the service corresponding to the downlink data matches the first subscription message;

[0046] If the service corresponding to the downlink data matches the first subscription message, the first message is sent to the application function device.

[0047] In the above scheme, the management function device can receive the first subscription message from the application function device. The management function device can also obtain at least one of the following from the first subscription message: target service type, target service identifier, target sender information, or target access network type. Based on the matching of the target service type, target service identifier, target sender information, or target access network type with the service corresponding to the downlink data, the number of times the management function device sends the reachability status is reduced, thus saving the signaling overhead of the management function device.

[0048] In one possible implementation of the second aspect, sending the first message to the application function device includes:

[0049] Receive a downlink data notification message from a user function device, the downlink data notification message being used to indicate that downlink data has arrived, the downlink data being the data sent to the first terminal device;

[0050] Based on the downlink data notification message, determine whether the service corresponding to the downlink data is a target service, or whether it is a target service type, or whether it comes from a target sender, or whether the downlink data is accessed through a target access network type;

[0051] If the service corresponding to the downlink data is the target service, or is the target service type, or comes from the target sender, or the downlink data accesses the network through the target access network type, the first message is sent to the application function device.

[0052] In the above scheme, the management function device sends the first message to the application function device only when the service corresponding to the downlink data is the target service, or is the target service type, or comes from the target sender, or the downlink data is accessed through the target access network type. This reduces the number of times the management function device sends the reachability status and saves the signaling overhead of the management function device.

[0053] In one possible implementation of the second aspect, the first information is included in a paging message sent by the management function device to the first terminal device.

[0054] In the above scheme, the application function device can send first information, which the management function device can receive. After receiving the first information, the management function device sends a paging message to the first terminal device. The paging message includes the first information, so that the paged first terminal device can determine whether to access the network based on the first information, and determine whether to restore the user plane connection, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0055] Thirdly, embodiments of this application also provide a communication method, which is applied to a management function device. The management function device can be a communication device (such as a network device), and includes not only the communication device itself, but also some components within the communication device (e.g., circuits or chips responsible for communication functions (such as modem chips, also known as baseband chips, or system-on-a-chip or system-in-package chips containing modem cores)). Alternatively, it can be a logic module or software capable of implementing all or part of the communication device's functions. The method includes:

[0056] Receive a downlink data notification message from a user function device, the downlink data notification message being used to indicate that downlink data has arrived, the downlink data being data sent to the first terminal device;

[0057] The fourth information is sent to the application function device according to the downlink data notification message. The fourth information is used to obtain the first information corresponding to the downlink data. The first information is used by the first terminal device to determine whether to access the network.

[0058] Receive the first information from the application function device.

[0059] In the above scheme, when downlink data arrives, the management function device sends fourth information to the application function device. For example, the management function device sends the status information of the first terminal device to the application function device, or requests first information from the first terminal device. The application function device sends the first information to the management function device, which receives it. This first information can then be used by the first terminal device to determine whether to access the network. Based on this first information, the first terminal device determines whether to access the network to decide whether to restore the user plane connection. This approach reduces calls to the terminal device while ensuring successful information transmission, avoiding wasted transmission resources and reducing the terminal device's power consumption.

[0060] In one possible implementation of the third aspect, sending the fourth information to the application function device according to the downlink data notification message includes:

[0061] Based on the target service type corresponding to the downlink data, the fourth information is sent to the application function device;

[0062] or,

[0063] Based on the target service corresponding to the downlink data, the fourth information is sent to the application function device;

[0064] or,

[0065] Based on the fact that the downlink data originates from the target sender, the fourth information is sent to the application function device;

[0066] or,

[0067] Based on the downlink data, access the network through the target access network type and send the fourth information to the application function device.

[0068] In the above scheme, when the service is the target service type, or comes from the target sender, or the service is the target service, or the downlink data is accessed through the target access network type, the management function device sends the fourth information to the application function device, so that the application function device can obtain the fourth information. Therefore, the number of times the fourth information is sent can be reduced, and the signaling overhead of the management function device can be saved.

[0069] In one possible implementation of the third aspect, sending the fourth information to the application function device according to the downlink data notification message includes:

[0070] Whether to allow the first terminal device to use the target service is determined based on third information, wherein the third information includes at least one of the following: the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device;

[0071] If the first terminal device is allowed to use the target service, the fourth information is sent to the application function device according to the downlink data notification message.

[0072] In the above scheme, when the first terminal device is allowed to use the target service, the management function device sends the fourth information to the application function device according to the downlink data notification message, so that the application function device can obtain the fourth information. Therefore, the number of times the fourth information is sent can be reduced, and the signaling overhead of the management function device can be saved.

[0073] In one possible implementation of the third aspect, sending the fourth information to the application function device according to the downlink data notification message includes:

[0074] The application function device is sent a fourth message according to the downlink data notification message. The fourth message includes a second field, which is used to indicate the reachability status of the first terminal device.

[0075] In the above scheme, the management function device can send fourth information to the application function device. The fourth information includes a second field, which indicates the reachability status of the first terminal device. This allows the application function device to obtain the reachability status of the first terminal device based on the second field in the fourth information. The application function device then sends the first information based on the reachability status of the first terminal device, thereby reducing the number of times the first information is sent and saving the signaling overhead of the application function device.

[0076] In one possible implementation of the third aspect, the second field is used to indicate the reachability status of the first terminal device, including:

[0077] The second field is used to indicate that the first terminal device is in an idle state, or that the first terminal device has entered an idle state.

[0078] In the above scheme, the management function device determines that the first terminal device is in an idle state, and can configure the second field in the fourth information based on the first terminal device being in an idle state. Alternatively, the management function device determines that the first terminal device has entered an idle state, for example, when the first terminal device switches from a connected state to an idle state. The management function device can then configure the second field in the fourth information based on the first terminal device entering an idle state, thereby enabling the management function device to indicate the reachability status of the first terminal device to the application function device.

[0079] In one possible implementation of the third aspect, sending the fourth information to the application function device according to the downlink data notification message includes:

[0080] The application function device is sent a fourth piece of information according to the downlink data notification message. The fourth piece of information includes a third field, which is used to request the first information corresponding to the downlink data from the application function device.

[0081] In the above scheme, the downlink data notification message is sent from the user plane function device to the management function device, and the downlink data notification message is used to indicate the arrival of downlink data. The fourth information is used to obtain the first information corresponding to the downlink data. The management function device can request the first information from the application function device, which then sends the first information, enabling the management function device to obtain it. Specifically, the management function device can send the fourth information, which includes a third field. This third field can be a request field, used to request the first information corresponding to the downlink data from the application function device. The application function device sends the first information to the management function device based on the third field included in the fourth information.

[0082] Fourthly, embodiments of this application also provide a communication method, which is applied to an application function device. The application function device can be a communication device (such as a network device), and includes not only the communication device itself, but also some components within the communication device (e.g., circuits or chips responsible for communication functions (such as modem chips, also known as baseband chips, or system-on-a-chip or system-in-package chips containing modem cores)). Alternatively, it can be a logic module or software capable of implementing all or part of the communication device's functions. The method includes:

[0083] The system receives fourth information from a management function device. The fourth information is used to obtain first information corresponding to downlink data. The downlink data is data sent to the first terminal device. The first information is used by the first terminal device to determine whether to access the network.

[0084] The first information is sent to the management function device according to the fourth information.

[0085] In the above scheme, when downlink data arrives, the management function device sends fourth information to the application function device. For example, the management function device sends the status information of the first terminal device to the application function device, or requests first information from the first terminal device. The application function device sends the first information to the management function device, which receives it. This first information can then be used by the first terminal device to determine whether to access the network. Based on this first information, the first terminal device determines whether to access the network to decide whether to restore the user plane connection. This approach reduces calls to the terminal device while ensuring successful information transmission, avoiding wasted transmission resources and reducing the terminal device's power consumption.

[0086] In one possible implementation of the fourth aspect, the method further includes:

[0087] The downlink data is sent to the user function device, and the downlink data is used by the user function device to send a downlink data notification message to the management function device.

[0088] In the above scheme, after the application function device obtains the downlink data, it can send the downlink data to the user function device. The user function device can generate a downlink data notification message based on the downlink data. The downlink data notification message is used to indicate that there is downlink data to be sent to the first terminal device.

[0089] In one possible implementation of the fourth aspect, the fourth information includes a second field, which is used to indicate the reachability status of the first terminal device;

[0090] or,

[0091] The fourth information includes a third field, which is used by the application function device to request the first information corresponding to the downlink data.

[0092] In the above scheme, the management function device can configure the second field in the fourth information based on whether the first terminal device is in an idle state, or the management function device can configure the second field in the fourth information based on whether the first terminal device enters an idle state, thereby enabling the management function device to indicate the reachability status of the first terminal device to the application function device. The management function device can send the fourth information, which includes a third field. The third field can be a request field, used to request the first information corresponding to the downlink data from the application function device. The application function device sends the first information to the management function device based on the third field included in the fourth information.

[0093] Fifthly, embodiments of this application also provide a communication method, which is applied to a management function device. The management function device can be a communication device (such as a network device), and includes not only the communication device itself, but also some components within the communication device (e.g., circuits or chips responsible for communication functions (such as modem chips, also known as baseband chips, or system-on-a-chip or system-in-package chips containing modem cores)). Alternatively, it can be a logic module or software capable of implementing all or part of the communication device's functions. The method includes:

[0094] In response to the network access request of the first terminal device, a second subscription message is sent to the application function device. The second subscription message is used to subscribe to the first information of the first terminal device. The first information is used by the first terminal device to determine whether to access the network.

[0095] Receive the first information sent by the application function device.

[0096] In the above scheme, in response to the network access request of the first terminal device, the management function device sends a second subscription message to the application function device. The management function device can subscribe to the first information of the first terminal device. The application function device sends the first information to the management function device according to the second subscription message. The first terminal device determines whether to access the network based on the first information, and determines whether to restore the user plane connection. While ensuring successful information transmission, the number of calls to the terminal device is reduced, transmission resources are not wasted, and the power consumption of the terminal device is reduced.

[0097] In one possible implementation of the fifth aspect, sending the second subscription message to the application function device includes:

[0098] Whether to allow the first terminal device to use the target service is determined based on third information, wherein the third information includes at least one of the following: the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device;

[0099] If the first terminal device is allowed to use the target service, the second subscription message is sent to the application function device.

[0100] In the above scheme, when the first terminal device is allowed to use the target service, the management function device sends a second subscription message to the user device, thereby enabling the management function device to obtain the first information based on the second subscription message and achieve highly reliable transmission of the first information.

[0101] In one possible implementation of the fifth aspect, sending the second subscription message to the application function device includes:

[0102] Receive downlink data notification messages from user functional devices;

[0103] A second subscription message is sent to the application function device according to the downlink data notification message. The second subscription message includes a fourth field, which is used to request the application function device to send the first information.

[0104] In the above scheme, the management function device can send a second subscription message to the application function device according to the downlink data notification message. The management function device can configure the fourth field of the second subscription message and request the application function device to send the first information through the fourth field. Thus, the application function device obtains the fourth field of the second subscription message and sends the first information to the management function device according to the fourth field. Therefore, the number of times the first information is sent can be reduced, and the signaling overhead of the application function device can be saved.

[0105] In one possible implementation of the fifth aspect, sending the second subscription message to the application function device includes:

[0106] Receive downlink data notification messages from user functional devices;

[0107] Determine whether the service corresponding to the downlink data is a target service, or whether the service corresponding to the downlink data is a target service type, or whether the service corresponding to the downlink data comes from a target sender, or whether the downlink data is accessed through a target access network type;

[0108] If the service corresponding to the downlink data is the target service, or the service corresponding to the downlink data is a target service type, or the service corresponding to the downlink data comes from the target sender, or the downlink data accesses the network through the target access network type, the second subscription message is sent to the application function device.

[0109] In the above scheme, for the description of the target service type, target service and target sender, please refer to Figure 6 and the description in the aforementioned A11 embodiment. When the service corresponding to the downlink data is the target service, or the corresponding service is not the target service type, or the service corresponding to the downlink data comes from the target sender, or the downlink data accesses the network through the target access network type, the management function device sends the first information to the application function device to achieve high-reliability transmission for the target service.

[0110] In one possible implementation of the fifth aspect, receiving the first information sent by the application function device includes:

[0111] Receive downlink data notification messages from user functional devices;

[0112] After a preset time, the first information sent by the application function device is received, wherein the preset time starts from the time the downlink data notification message is received.

[0113] In the above scheme, the management function device receives a downlink data notification message from the user function device. If the downlink data notification message is received before the first information is received, the management function device needs to wait for a preset time after receiving the downlink data notification message. The preset time begins when the downlink data notification message is received. After the preset time, the management function device receives the first information sent by the application function device. In this embodiment, the management function device waits for the preset time before receiving the first information to ensure that the first information is received.

[0114] Sixthly, embodiments of this application also provide a communication method, which is applied to an application function device. The application function device may be a communication device (such as a network device), and includes not only the communication device itself, but also some components within the communication device (e.g., circuits or chips responsible for communication functions (such as modem chips, also known as baseband chips, or system-on-a-chip or system-in-package chips containing modem cores)). Alternatively, it may be a logic module or software capable of implementing all or part of the communication device's functions. The method includes:

[0115] Receive a second subscription message from the management function device, the second subscription message being used to subscribe to first information of the first terminal device, the first information being used by the first terminal device to determine whether to access the network;

[0116] The first information is sent to the management function device according to the second subscription message.

[0117] In the above scheme, in response to the network access request of the first terminal device, the management function device sends a second subscription message to the application function device. The management function device can subscribe to the first information of the first terminal device. The application function device sends the first information to the management function device according to the second subscription message. The first terminal device determines whether to access the network based on the first information, and determines whether to restore the user plane connection. While ensuring successful information transmission, the number of calls to the terminal device is reduced, transmission resources are not wasted, and the power consumption of the terminal device is reduced.

[0118] In one possible implementation of the sixth aspect, the method further includes:

[0119] Downlink data is sent to the user function device, and the downlink data is used by the user function device to send a downlink data notification message to the management function device.

[0120] In the above scheme, after the application function device obtains the downlink data, it can send the downlink data to the user function device. The user function device can generate a downlink data notification message based on the downlink data. The downlink data notification message is used to indicate that there is downlink data to be sent to the first terminal device.

[0121] In one possible implementation of the sixth aspect, sending the first information to the management function device according to the second subscription message includes:

[0122] Receive a second message sent by the management function device, the second message being used to request the application function device to send the first information;

[0123] The first information is sent to the management function device according to the second subscription message and the second message.

[0124] In the above scheme, in order to receive the first information as soon as possible, the management function device can also generate a second message. The first message is used to request the application function device to send the first information. The application function device sends the first information to the management function device according to the second message, so that the management function device can receive the first information in a timely manner.

[0125] Seventhly, embodiments of this application also provide a communication device, specifically an application function device, the communication device comprising:

[0126] A receiving module is configured to receive a first message from a management function device, wherein the first message is used to indicate the reachability status of a first terminal device;

[0127] The sending module is configured to send first information to the management function device when the first message indicates that the first terminal device is unreachable, wherein the first information is used by the first terminal device to determine whether to access the network.

[0128] In the seventh aspect of this application, the constituent modules of the communication device may also perform the steps described in the first aspect and various possible implementations, as detailed in the foregoing description of the first aspect and various possible implementations.

[0129] Eighthly, embodiments of this application also provide a communication device, specifically a management function device, the communication device comprising:

[0130] The sending module is used to send a first message to the application function device, wherein the first message is used to indicate the reachability status of the first terminal device;

[0131] The receiving module is used to receive first information sent by the application function device, wherein the first information is used by the first terminal device to determine whether to access the network.

[0132] In the eighth aspect of this application, the constituent modules of the communication device may also perform the steps described in the second aspect and various possible implementations, as detailed in the foregoing description of the second aspect and various possible implementations.

[0133] Ninthly, embodiments of this application also provide a communication device, specifically a management function device, the communication device comprising:

[0134] The receiving module is configured to receive a downlink data notification message from a user function device, wherein the downlink data notification message indicates that downlink data has arrived, and the downlink data is data sent to the first terminal device;

[0135] The sending module is used to send fourth information to the application function device according to the downlink data notification message. The fourth information is used to obtain first information corresponding to the downlink data. The first information is used by the first terminal device to determine whether to access the network.

[0136] The receiving module is also configured to receive the first information from the application function device.

[0137] In the ninth aspect of this application, the constituent modules of the communication device may also perform the steps described in the third aspect and various possible implementations, as detailed in the foregoing description of the third aspect and various possible implementations.

[0138] Tenthly, embodiments of this application also provide a communication device, specifically an application function device, the communication device comprising:

[0139] The receiving module is used to receive fourth information from the management function device. The fourth information is used to obtain first information corresponding to downlink data. The downlink data is data sent to the first terminal device. The first information is used by the first terminal device to determine whether to access the network.

[0140] The sending module is used to send the first information to the management function device according to the fourth information.

[0141] In the tenth aspect of this application, the constituent modules of the communication device may also perform the steps described in the fourth aspect and various possible implementations, as detailed in the foregoing description of the fourth aspect and various possible implementations.

[0142] Eleventhly, embodiments of this application also provide a communication device, specifically a management function device, the communication device comprising:

[0143] The sending module is used to send a second subscription message to the application function device in response to the network access request of the first terminal device. The second subscription message is used to subscribe to the first information of the first terminal device, and the first information is used by the first terminal device to determine whether to access the network.

[0144] A receiving module is used to receive the first information sent by the application function device.

[0145] In the eleventh aspect of this application, the constituent modules of the communication device may also perform the steps described in the fifth aspect and various possible implementations, as detailed in the foregoing description of the fifth aspect and various possible implementations.

[0146] In a twelfth aspect, embodiments of this application also provide a communication device, specifically an application function device, the communication device comprising:

[0147] The receiving module is configured to receive a second subscription message from the management function device, the second subscription message being used to subscribe to first information of the first terminal device, the first information being used by the first terminal device to determine whether to access the network;

[0148] The sending module is used to send the first information to the management function device according to the second subscription message.

[0149] In the twelfth aspect of this application, the constituent modules of the communication device may also perform the steps described in the sixth aspect and various possible implementations, as detailed in the foregoing description of the sixth aspect and various possible implementations.

[0150] In a thirteenth aspect, embodiments of this application provide a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method described in any one of the first to sixth aspects.

[0151] In a fourteenth aspect, embodiments of this application provide a computer program product containing instructions that, when run on a computer, cause the computer to perform the method described in any one of the first to sixth aspects.

[0152] In a fifteenth aspect, embodiments of this application provide a communication device, which may include entities such as terminal devices or chips. The communication device includes: a processor and a memory; the memory is used to store instructions; the processor is used to execute the instructions in the memory, causing the communication device to perform the method as described in any one of the first to sixth aspects.

[0153] In a sixteenth aspect, this application provides a chip or chip system including a processor for supporting a communication device in implementing the functions involved in the foregoing aspects, such as transmitting or processing data and / or information involved in the foregoing methods. In one possible design, the chip system further includes a memory for storing program instructions and data necessary for the communication device. The chip system may be composed of chips or may include chips and other discrete devices.

[0154] In a seventeenth aspect, embodiments of this application provide a chip or chip system, including one or more interface circuits and one or more processors; the interface circuits are used to receive signals from the memory of an electronic device and send signals to the processors, the signals including computer instructions stored in the memory; when the processor executes the computer instructions, it causes the electronic device to perform the communication method of any one of the first to sixth aspects.

[0155] Eighteenthly, embodiments of this application provide a communication system, including:

[0156] The communication device as described in any of the seventh aspects above and the communication device as described in any of the eighth aspects above;

[0157] or,

[0158] The communication device as described in any of the ninth aspects above and the communication device as described in any of the tenth aspects above;

[0159] or,

[0160] The communication device as described in any one of the eleventh aspects above and the communication device as described in any one of the twelfth aspects above. Attached Figure Description

[0161] Figure 1 is a schematic diagram of the architecture of a 5G communication system applicable to an embodiment of this application;

[0162] Figure 2 is a schematic diagram of the architecture of a 4G communication system applicable to an embodiment of this application;

[0163] Figures 3a and 3b are schematic diagrams of the architecture of a satellite communication system applicable to the embodiments of this application;

[0164] Figure 4 is a schematic diagram of an IMS voice call process;

[0165] Figure 5 is a schematic diagram of the composition structure of a communication system applicable to an embodiment of this application;

[0166] Figure 6 is a flowchart illustrating a communication method for interaction between an application function device and a management function device, provided in an embodiment of this application.

[0167] Figure 7 is a flowchart illustrating another communication method for interaction between application function devices and management function devices provided in an embodiment of this application.

[0168] Figure 8 is a flowchart illustrating another communication method for interaction between application function devices and management function devices provided in an embodiment of this application.

[0169] Figure 9 is a schematic diagram of an application scenario where an application function device and a management function device interact, according to an embodiment of this application.

[0170] Figure 10 is a schematic diagram of another application scenario of interaction between application function devices and management function devices provided in an embodiment of this application;

[0171] Figure 11 is a schematic diagram of another application scenario of interaction between application function devices and management function devices provided in an embodiment of this application;

[0172] Figure 12 is a schematic diagram of the composition structure of a communication device provided in an embodiment of this application;

[0173] Figure 13 is a schematic diagram of the composition structure of another communication device provided in an embodiment of this application. Detailed Implementation

[0174] This application provides communication methods and devices, storage media, program products, chips and chip systems, which are used to reduce calls to terminal devices while ensuring successful information transmission, thereby avoiding waste of transmission resources and reducing the power consumption of terminal devices.

[0175] The embodiments of this application will now be described with reference to the accompanying drawings.

[0176] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0177] The technical solutions of this application can be applied to various data processing communication systems, such as 5th generation (5G) communication systems, new radio (NR), 4th generation (4G), future communication systems, or satellite communication systems. For example, it is applicable to the following communication systems: Long Term Evolution (LTE), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency-Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), and other systems. The term "system" can be used interchangeably with "network." CDMA systems can implement wireless technologies such as Universal Terrestrial Radio Access (UTRA) and CDMA2000. UTRA can include wideband CDMA (WCDMA) technology and other CDMA variants. CDMA2000 can cover interim standard (IS) 2000 (IS-2000), IS-95, and IS-856 standards. TDMA systems can implement wireless technologies such as Global System for Mobile Communication (GSM). OFDMA systems can implement wireless technologies such as evolved Universal Radio Terrestrial Access (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash OFDMA. UTRA and E-UTRA are UMTS and its evolved versions. Furthermore, the technical solutions provided in this application can also be applied to future communication systems. The system architecture and service scenarios described in this application are for the purpose of more clearly illustrating the technical solutions of this application and do not constitute a limitation on the technical solutions provided in this application. Those skilled in the art will understand that with the evolution of network architecture and the emergence of new service scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

[0178] Figure 1 is a schematic diagram of the communication system applicable to this application. As shown in Figure 1, the network architecture can include three parts: terminal equipment, data network (DN), and core network. The functions of the network elements in each part are briefly described below.

[0179] The terminal equipment portion may include terminal equipment 110, which may also be referred to as user equipment (UE). The terminal equipment can access the aforementioned communication system and is a device or module with corresponding communication functions. Terminal equipment may also be referred to as user equipment (UE), terminal, user device, access terminal, user unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, terminal unit, terminal station, terminal device, wireless communication equipment, user agent, or user device. The terminal typically contains communication modules, circuits, or chips that perform the corresponding communication functions. The terminal may also be configured with program instructions for performing the corresponding communication functions.

[0180] For example, the terminal in this application embodiment can be a mobile phone, a personal digital assistant (PDA) computer, a laptop computer, a tablet computer, a drone, a computer with wireless transceiver capabilities, a machine-type communication (MTC) terminal, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a point-of-sale (POS) machine, customer-premises equipment (CPE), a light user equipment (UE), a reduced capability UE (REDCAP UE), a wearable device (e.g., a smartwatch, smart bracelet, pedometer, smart glasses), an Internet of Things (IoT) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical care, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, or a wireless terminal in a smart home. Wireless terminals in the home (such as game consoles, smart TVs, smart speakers, smart refrigerators, and fitness equipment), transportation vehicles with wireless communication capabilities, communication modules, roadside units (RSUs) with terminal functions, and flying equipment (such as smart robots, hot air balloons, drones, and airplanes). Terminal equipment can also be vehicle devices, such as complete vehicle devices, vehicle-mounted modules, vehicle-mounted chips, on-board units (OBUs), or telematics boxes (T-BOXs).

[0181] The core network portion may include, but is not limited to, RAN 120 and the core network (CN) portion.

[0182] RAN 120 is the implementation system between service nodes and terminal equipment 110 in the operator network. For terminal equipment 110 to access the operator network, it first goes through RAN 120, and then can connect to service nodes in the operator network through RAN 120.

[0183] Access network equipment can be a network-side device with wireless transceiver capabilities. It can be a device within a radio access network (RAN) that provides wireless communication functionality to terminal devices, referred to as RAN equipment. RAN can be a cellular system related to the 3rd Generation Partnership Project (3GPP), such as a 5G mobile communication system, or a future-oriented evolution system. RAN can also be an open radio access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. For example, this access network equipment can be a base station, an evolved NodeB (eNodeB), a base station (NodeB, gNB) in a 5G mobile communication system, a 3GPP later evolution base station, a transmission reception point (TRP), an access node, a wireless relay node, or a wireless backhaul node in a WiFi system. In communication systems employing different radio access technologies (RATs), the names of devices with base station functionality may differ. For example, in an LTE system, it may be called an eNB or eNodeB, and in a 5G communication system or NR system, it may be called a gNB. This application does not limit the specific name of the base station. Access network equipment may include one or more co-located or non-co-located transmit / receive points. Furthermore, access network equipment may include at least one of the following: one or more central units (CU), one or more distributed units (DU), and one or more radio units (RU). In different systems, CU (or CU-CP and CU-UP), DU, or RU may also have different names, but those skilled in the art will understand their meaning. For example, in an open RAN (ORAN) system, CU may also be called O-CU (open CU), DU may also be called O-DU (open DU), CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application may be implemented through software modules, hardware modules, or a combination of software and hardware modules. For example, the functionality of a CU can be implemented by one entity or different entities.For example, the functions of the CU can be further divided, separating the control plane and user plane and implementing them through different entities: the control plane CU entity (CU-CP entity) and the user plane CU entity (CU-UP entity). The CU-CP and CU-UP entities can be coupled with the DU to jointly complete the functions of the access network device. For instance, the CU is responsible for handling non-real-time protocols and services, implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for handling physical layer protocols and real-time services, implementing the functions of the radio link control (RLC), media access control (MAC), and physical (PHY) layers. In this way, some functions of the wireless access network device can be implemented through multiple network function entities. These network function entities can be network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform). The access network device can also include an active antenna unit (AAU). The AAU implements some physical layer processing functions, radio frequency processing, and related functions of the active antenna. Since information from the RRC layer ultimately becomes information from the PHY layer, or is derived from information from the PHY layer, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered as being sent by the DU, or by the DU+AAU. It is understood that access network equipment can be one or more of the following: CU nodes, DU nodes, and AAU nodes. Furthermore, the CU can be classified as an access network device in the radio access network (RAN), or it can be classified as an access network device in the core network (CN); this application does not limit this. For example, in V2X technology, access network equipment can be a roadside unit (RSU). Multiple access network devices in a communication system can be base stations of the same type or different types. Base stations can communicate with terminal devices, or they can communicate with terminal devices through relay stations. In the embodiments of this application, the device used to implement the access network device function can be the access network device itself, or it can be a device that supports the access network device in implementing this function, such as a chip system or a combination of devices or components that can implement the access network device function; this device can be installed in the access network device. In this embodiment of the application, the chip system may be composed of chips or may include chips and other discrete devices.

[0184] The CN component may include, but is not limited to, the following Network Functions (NFs): User plane function (UPF) 130, Network exposure function (NEF) 131, Network repository function (NRF) 132, Policy control function (PCF) 133, Unified data management (UDM) 134, Unified data repository (UDR) 135, Network data analytics function (NWDAF) 136, Authentication server function (AUSF) 137, Access and Mobility Management Function (AMF) 138, Session management function (SMF) 139.

[0185] Data network DN 140, also known as packet data network (PDN), is typically a network located outside the operator's network, such as a third-party network. However, in some implementations, the DN can also be deployed by the operator, meaning the DN is part of a PLMN. This application does not restrict whether the DN belongs to a PLMN. An operator's PLMN can connect to multiple data networks DN 140. Various services can be deployed on the data network DN 140, providing data and / or voice services to terminal devices 110. For example, data network DN 140 can be a private network of a smart factory. Sensors installed in the workshop of the smart factory can be terminal devices 110. A control server for the sensors is deployed in the data network DN 140, providing services to the sensors. The sensors can communicate with the control server, obtain instructions from the control server, and transmit the collected sensor data to the control server according to the instructions. As another example, data network DN 140 can be an internal office network of a company. The mobile phones or computers of the company's employees can be terminal devices 110, and the employees' mobile phones or computers can access information and data resources on the company's internal office network. Terminal device 110 can establish a connection with the operator network through an interface (such as N1) provided by the operator network and use data and / or voice services provided by the operator network. Terminal device 110 can also access data network DN 140 through the operator network and use operator services deployed on data network DN 140, and / or services provided by third parties.

[0186] The following is a brief explanation of the NF functions included in CN.

[0187] 1. UPF 130 is a gateway provided by the operator, serving as the gateway for communication between the operator's network and the data network DN 140. UPF 130 includes user plane-related functions such as packet routing and transmission, packet inspection, service usage reporting, quality of service (QoS) processing, uplink packet inspection, and downlink packet storage.

[0188] 2. NEF 131 is a control plane function provided by the operator. It mainly enables third parties to use the services provided by the network, supports the network to open its capabilities, events and data analysis, provides security configuration information to the PLMN from external applications, converts information exchanged between the PLMN and external networks, provides the application programming interface (API) interface exposed by the operator network, and provides interaction between external servers and the internal operator network.

[0189] 3. NRF 132 is a control plane function provided by the operator, which can be used to maintain real-time information about network functions and services in the network. For example, it supports network service discovery, maintains the NF configuration data (NF profile) of NF instances to support services, supports service communication proxy (SCP) service discovery, maintains the SCP configuration data (SCP profile) of SCP instances, sends notifications about newly registered, deregistered, and updated NFs and SCPs, and maintains the health status of NFs and SCPs.

[0190] 4. PCF 133 is a control plane function provided by the operator. It supports a unified policy framework to govern network behavior, provide policy rules and subscription information related to policy decisions to other control functions, etc.

[0191] 5. UDM 134 is a control plane function provided by the operator, responsible for storing information such as the subscriber permanent identifier (SUPI), the generic public subscription identifier (GPSI), and credentials of subscribed users in the operator's network. The SUPI is protected for confidentiality during transmission; this confidential SUPI is called the subscription concealed identifier (SUCI). The information stored in UDM 134 can be used for authentication and authorization of terminal device 110 when accessing the operator's network. Specifically, the subscribed users of the aforementioned operator's network can be users of services provided by the operator's network, such as users using a subscriber identity module (SIM) card from operator A or operator B. The credentials of the subscribed users can be a long-term key stored in the SIM card or a small file containing information related to SIM card encryption, used for authentication and / or authorization. It should be noted that, for the sake of convenience, the permanent identifier, trust certificate, security context, authentication data (cookie), and token are not distinguished or limited in this application embodiment for the purpose of description.

[0192] 6. UDR 135 is a control plane function provided by the operator, which provides UDM with the ability to store and retrieve subscription data, PCF with the ability to store and retrieve policy data, and store and retrieve user NF group ID information, etc.

[0193] 7. NWDAF 136 is a control plane function provided by the operator. Its main function is to collect data from NF, external application functions (AF), and operations, administration and maintenance (OAM) systems, and to provide NWDAF service registration, data sharing, and analysis data to NF and AF. In this application, NWDAF is mainly responsible for security-related data analysis. Therefore, in this application, NWDAF can also be understood as a network element with security analysis capabilities. The term NWDAF is just an example; other network element names may be used subsequently, and this application does not limit this.

[0194] 8. AUSF 137 is a control plane function provided by the operator, typically used for Level 1 authentication, i.e., authentication between terminal device 110 (the subscriber) and the operator's network. After receiving an authentication request from the subscriber, AUSF 137 can authenticate and / or authorize the subscriber using the authentication and / or authorization information stored in UDM 134, or generate the subscriber's authentication and / or authorization information using UDM 134. AUSF 137 can then send the authentication and / or authorization information back to the subscriber.

[0195] 9. AMF 138 is a control plane network function provided by the operator's network, which is responsible for access control and mobility management of terminal equipment 110 accessing the operator's network. This includes functions such as mobility state management, allocation of temporary user identity identifiers, authentication and authorization of users.

[0196] 10. SMF 139 is a control plane network function provided by the operator network, responsible for managing the PDU sessions of terminal equipment 110. A PDU session is a channel used to transmit PDUs. Terminal equipment exchanges PDUs with the data network DN 140 through PDU sessions. SMF 139 is responsible for establishing, maintaining, and deleting PDU sessions. SMF 139 includes session management (such as session establishment, modification, and release, including tunnel maintenance between user plane functions UPF 130 and RAN 120), selection and control of UPF 130, service and session continuity (SSC) mode selection, roaming, and other session-related functions.

[0197] 11. AF 141 is a control plane network function provided by the operator's network. It is used to provide application layer information and can interact with the policy framework or directly with the policy framework to make policy decision requests through network open function elements. It can be located inside or outside the operator's network.

[0198] It is understandable that the aforementioned network elements or functions can be physical entities in hardware devices, software instances running on dedicated hardware, or virtualization functions instantiated on a shared platform (e.g., a cloud platform). Simply put, an NF can be implemented in hardware or software.

[0199] In Figure 1, Nnef, Nnrf, Npcf, Nudm, Nudr, Nnwdaf, Nausf, Namf, Nsmf, Nran, N1, N2, N3, N4, and N6 are interface sequence numbers. For example, the meanings of these interface sequence numbers can be found in the 3GPP standard protocols, and this application does not limit the meaning of these interface sequence numbers. It should be noted that the interface names between the various network functions in the figure are merely examples; in specific implementations, the interface names of this system architecture may be other names, and this application does not limit them. Furthermore, the names of the messages (or signaling) transmitted between the various network elements are also merely examples and do not constitute any limitation on the function of the messages themselves.

[0200] For ease of explanation, network functions (such as NEF 131…SMF139) are collectively referred to as NFs in this application embodiment. That is, any NF described below in this application embodiment can be replaced by any network function. In addition, Figure 1 only schematically illustrates some network functions, and the NFs described below are not limited to the network functions shown in Figure 1.

[0201] It should be understood that the network architecture described above for the embodiments of this application is only a network architecture described from the perspective of service-oriented architecture. The network architecture applicable to the embodiments of this application is not limited to this, and any network architecture that can realize the functions of the above-described network elements is applicable to the embodiments of this application. For example, at least one of the network elements, access network devices, or terminal devices in this application can be deployed in NTN. For example, this application can be applied to a fourth-generation (4G) system as shown in Figure 2. As shown in Figure 2, the UE is the terminal device, the E-UTRAN is the 4G access network device or base station, and other network elements (except for the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) and Global System for Mobile Communications (GSM) / Enhanced Data Rate for GSM Evolution (EDGE) Radio Access Network (GERAN)) are core network elements. For example, the 4G network element Mobility Management Entity (MME) has mobility management and partial session management functions, corresponding to the 5G network elements AMF and SMF; the 4G network element Policy and Charging Rules Function (PCRF) corresponds to the 5G network element PCF; and the 4G network element Home Subscriber Server (Home Subscriber Server)... The server (HSS) corresponds to the 5G network element UDM, while the 4G network elements serving gateway (SGW) and PDN gateway (packet data network gateway (PGW) correspond to the 5G network element UPF.

[0202] E-UTRAN (Evolved Universal Terrestrial Radio Access Network) refers to a radio access network.

[0203] UTRAN (UMTS Terrestrial Radio Access Network) is the terrestrial radio access network (URAN) for UMTS, and it is an access method for UMTS, a third-generation mobile communication technology. The UMTS architecture includes the Universal Radio Access Network (URAN) and the UMTS Radio Access Network (URAN). URAN can be implemented in various ways. Depending on different conditions and environments, it can be implemented through evolution of the access network.

[0204] GERAN (GSM EDGE Radio Access Network) is the radio access network for GSM / EDGE wireless communication networks. GERAN is the radio access component of the Global System for Mobile Communications (GSM) / Enhanced Data Rate for GSM Evolution (EDGE) technology. GERAN is led by 3GPP (Third Generation Partnership Project).

[0205] It should also be understood that the core network elements shown in Figures 1 and 2 (such as AMF, SMF, UPF, NEF, MME, SGW, etc.) can be understood as network elements in the core network used to implement different functions, for example, they can be combined into network slices as needed. These core network elements can be independent devices or integrated into the same device to implement different functions. This application does not limit the specific form of the above-mentioned network elements. In addition, the network architecture shown in Figure 1 may also include other network elements, such as sensing function network elements, artificial intelligence logic function (e.g., model training logic function, analysis logic function) network elements, etc.

[0206] It should also be understood that the above naming is defined solely for the purpose of distinguishing different functions and should not constitute any limitation on this application. This application does not preclude the possibility of using other naming conventions in 5G networks and other future networks. For example, in future communication networks, some or all of the above-mentioned network elements may use the terminology from 5G, or they may use other names, etc.

[0207] The following describes a satellite communication system applicable to the embodiments of this application. The main application scenarios for satellite communication are in remote areas where cellular networks cannot provide coverage, assisting the UE in communication. There are also some scenarios where the low-latency characteristics of low-Earth orbit satellites are utilized to complete real-time transmissions.

[0208] Satellites can be categorized by orbital altitude into geostationary orbit (GEO), medium Earth orbit (MEO), and low Earth orbit (LEO). Understandably, even within LEO, MEO, and GEO, satellites exist at different altitudes. For example, in LEO, some satellites are deployed at an altitude of 600 km, while others are deployed at 1200 km. Different satellites can be connected via inter-satellite links (ISL), and several satellites connected by ISLs can be considered a constellation. The orbital trajectory of a satellite is predetermined and is characterized by ephemeris information in 3GPP. Ephemeris information includes the satellite's orbital altitude, its angle with the equatorial plane, etc., allowing the satellite's current spatial location to be determined.

[0209] The satellite architecture for a satellite communication system can include the following:

[0210] Figure 3a illustrates a satellite system architecture in transparent mode, employing a transparent satellite access architecture. The User Equipment (UE) connects to a Remote Radio Unit (RRU), which includes a satellite and a Non-Terrestrial Network Gateway (NTN Gateway). The RRU connects to the base station, enabling the UE to access the core network (CN) via satellite. The satellite acts as a transport layer node (TLN) and does not perform any data processing, hence the name "transparent satellite." In this architecture, the satellite is located in the fronthaul portion, connecting the UE and the base station. The NTN Gateway is another transport layer node connecting the satellite to the ground. The satellite and the NTN Gateway constitute the RRU.

[0211] Figure 3b shows a satellite system architecture in satellite regeneration mode, which adopts a regenerative satellite access architecture. User equipment accesses the core network through the satellite. At this time, the satellite acts as a base station. In other words, the base station is in an up-to-the-satellite state. The NG interface is set on the Satellite Radio Interface (SRI). The UE connects to the ground core network through the satellite base station and the NTN Gateway.

[0212] The satellite communication system provided in this application embodiment can adopt a transparent satellite architecture or a regenerated satellite architecture, and is not limited here.

[0213] In the aforementioned communication system, even when the UE is in a poor signal condition, it still needs to be able to receive paging messages. This paging process can be called a paging alert, high-reliability paging, or flexible notification. In this case, taking an IMS voice call as an example, the calling party's information can be sent to the called party. The paging UE (i.e., the called party) can then attempt to move to a location with better coverage and establish a connection with the calling party, such as by calling back the IMS voice call.

[0214] Please refer to Figure 4 for an illustration of the IMS call process in the communication system, which is mainly applied to IMS voice services.

[0215] Before the IMS call procedure begins, the calling UE (UE1) completes registration and establishes a user plane connection. Registration refers to UE1 initiating the registration process. In the communication system shown in Figure 2, registration refers to the attach procedure, while in the communication system shown in Figure 1, it refers to the registration procedure. The user plane connection refers to establishing the connection between UE1, the base station, and user plane network elements. In the communication system shown in Figure 2, the user plane connection refers to the connection between UE1, eNB, SGW, and PGW, while in the communication system shown in Figure 1, the user plane connection refers to the connection between UE1, gNB, and UPF. Similarly, UE2 also completes registration and establishes a user plane connection.

[0216] The following describes the steps involved in the IMS call process:

[0217] 1. The calling UE sends a Session Initiation Protocol Invitation Message (SIP INVITE) to the Proxy-Call Session Control Function (P-CSCF).

[0218] Among them, P-CSCF is the first contact node for users in the signaling plane in IMS. From the perspective of the Session Initialization Protocol (SIP), P-CSCF is an outbound and inbound SIP proxy server. All SIP signaling, whether from the user equipment (UE) or sent to the UE, must pass through P-CSCF.

[0219] 2. The P-CSCF sends an Authorization-Authentication Request (AAR) to the PCRF, and the PCRF sends an Authorization-Authentication Answer (AAA) to the P-CSCF. The P-CSCF then obtains the access network type.

[0220] 3. The P-CSCF sends a session initiation protocol invitation message to the IMS.

[0221] In this scenario, UE1 initiates an IMS call and sends a Session Initiation Protocol (SIP) invitation message to the IMS system through the core network user interface. This SIP invitation message carries information such as the called number, media type, codec, and bandwidth requirements. The SIP invitation message is a SIP signaling message carried on the default bearer; for example, the QoS Class Identifier (QCI) is 5. For the communication system shown in Figure 2, the core network user plane refers to the connection between the eNB, SGW, and PGW. For the communication system shown in Figure 1, the core network user plane refers to the connection between the gNB and UPF.

[0222] It is understandable that the aforementioned IMS is one way of implementing application function devices.

[0223] 4. IMS sends a session initiation protocol invitation message to P-CSCF.

[0224] 5. The P-CSCF sends a Session Initiation Protocol Invitation Message to the SGW or PGW.

[0225] In steps 4 and 5, the IMS sends the Session Initiation Protocol (SIP) invitation message to the called party. Specifically, the IMS sends the SIP invitation message to the P-CSCF, which then sends it to the called party's PGW, and the PGW then sends it to the SGW.

[0226] When the called UE is in an idle state, that is, the user plane connection of the called UE is disconnected, it is necessary to first page the called UE and then restore the user plane connection, as shown in subsequent steps 6 to 9.

[0227] 6. The SGW sends a downlink data notification (DDN) message to the MME.

[0228] 7-8. The MME sends a paging message to the base station in the registered area, and then the base station sends a paging message to the UE.

[0229] In particular, the paging message sent by the MME in steps 7-8 can be a high-reliability paging message, which can enhance the ordinary paging message, such as by enhancing the air interface channel design.

[0230] In addition, the highly reliable paging in this embodiment of the application can also be a paging process that is initiated again after the paging fails in steps 7-8.

[0231] 9. The paged UE restores the user plane connection by initiating a service request procedure.

[0232] 10. The SGW receives the Session Initiation Protocol Invitation Message and sends it to the UE via the restored user plane connection.

[0233] 11-16: Subsequent SIP signaling interactions are used to complete media negotiation, including encoding / decoding, media information, bandwidth requirements, etc.

[0234] Based on the various communication systems described in the foregoing embodiments of this application, taking the communication system shown in Figure 2 as an example, before the IMS call process begins, the calling party UE1 completes registration and establishes a user plane connection. Similarly, the called party UE2 also completes registration and establishes a user plane connection. When the called party UE2 is in an idle state, i.e., when the user plane connection of the called party UE2 is disconnected, it is necessary to successfully page the called party UE2 first, and then restore the user plane connection. However, if UE2 is paged, UE2 will restore the user plane connection. If the channel conditions are poor, UE2 will need to move to a location with better channel conditions before restoring the user plane connection, which may result in wasted transmission resources and increased power consumption of the terminal equipment.

[0235] This application provides a communication system applicable to satellite communication, cellular communication, and other communication scenarios. This application does not limit the applicable communication scenarios for the system. The paged terminal device can determine whether to access the network based on first information, thereby determining whether to restore the user plane connection, thus avoiding waste of transmission resources and reducing the power consumption of the terminal device. For scenarios with poor channel environments such as satellites, basements, and elevators, and further extending to normal scenarios, the solution provided in this application can also reduce signaling overhead.

[0236] Please refer to Figure 5. An embodiment of this application provides a communication system, which may include at least application function devices and management function devices, and may also include a first terminal device.

[0237] In a communication system provided in this application embodiment, the functions of the application function device and the management function device are mainly as follows:

[0238] The management function device is used to send a first message to the application function device, the first message being used to indicate the reachability status of the first terminal device;

[0239] An application function device is used to receive a first message from a management function device, the first message being used to indicate the reachability status of a first terminal device;

[0240] An application function device is used to send first information to a management function device when a first message indicates that the first terminal device is unreachable, wherein the first information is used by the first terminal device to determine whether to access the network.

[0241] A management function device is used to receive first information sent by an application function device, wherein the first information is used by a first terminal device to determine whether to access the network.

[0242] It should be noted that after receiving the first information, the management function device can send a paging message to the first terminal. This paging message includes the first information. For example, when downlink data arrives at the network and the first terminal device is in an idle state, the paging message sent by the management function device to the first terminal includes the first information. Specifically, the downlink data arriving at the network can be downlink data arriving at the SGW or downlink data arriving at the MME.

[0243] Optionally, the paging message sent by the management function device to the first terminal includes the first information, and may further include: when downlink data arrives at the network, the first terminal device is in an idle state, and the service corresponding to the downlink data is the target service, the paging message sent by the management function device to the first terminal includes the first information.

[0244] In the aforementioned communication system, the management function device sends a first message to the application function device, indicating the reachability status of the first terminal device. If the first message indicates that the first terminal device is unreachable, the application function device sends first information to the management function device. For example, if the first terminal device is unreachable but downlink data has arrived, the first terminal device can obtain the first information based on the received paging message. Since the first terminal device can determine whether to access the network based on the first information, and thus determine whether to restore the user plane connection, calls to the terminal device are reduced while ensuring successful information transmission, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0245] In another communication system provided in this application embodiment, the communication system may at least include application function devices and management function devices, and may further include user function devices and a first terminal device. The functions of the application function devices and the functions of the management function devices are mainly as follows:

[0246] The management function device is used to receive downlink data notification messages from the user function device. The downlink data notification messages are used to indicate that downlink data has arrived. The downlink data is the data sent to the first terminal device.

[0247] The management function device is used to send fourth information to the application function device according to the downlink data notification message. The fourth information is used to obtain the first information corresponding to the downlink data. The first information is used by the first terminal device to determine whether to access the network.

[0248] An application function device is used to receive fourth information from a management function device, the first information is used to obtain the first information corresponding to the downlink data, and the first information is used by the first terminal device to determine whether to access the network.

[0249] An application function device is used to send the first information to the management function device based on the fourth information;

[0250] Management function device, used to receive initial information from application function device.

[0251] In the aforementioned communication system, in this embodiment, when downlink data arrives, the management function device sends fourth information to the application function device. For example, the management function device sends the status information of the first terminal device to the application function device, or requests first information from the first terminal device from the application function device. The application function device sends the first information to the management function device, and the management function device receives the first information. This first information can then be used by the first terminal device to determine whether to access the network. Based on this first information, the first terminal device determines whether to access the network to determine whether to restore the user plane connection. This reduces calls to the terminal device while ensuring successful information transmission, avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0252] In another communication system provided in this application embodiment, the functions of the application function device and the management function device are mainly as follows:

[0253] The management function device is used to send a second subscription message to the application function device in response to the network access request of the first terminal device. The second subscription message is used to subscribe to the first information of the first terminal device. The first information is used to determine whether the first terminal device accesses the network.

[0254] An application function device is used to receive a second subscription message from a management function device. The second subscription message is used to subscribe to first information of a first terminal device. The first information is used to determine whether the first terminal device is connected to the network.

[0255] An application function device is used to send first information to a management function device based on a second subscription message;

[0256] The management function device is used to receive the first information sent by the application function device.

[0257] In the above communication system, in response to the network access request of the first terminal device, the management function device sends a second subscription message to the application function device. The management function device can subscribe to the first information of the first terminal device. The application function device sends the first information to the management function device according to the second subscription message. The first terminal device determines whether to access the network based on the first information, and determines whether to restore the user plane connection. While ensuring successful information transmission, the system reduces calls to the terminal device, avoids waste of transmission resources, and reduces the power consumption of the terminal device.

[0258] Based on the communication system shown in Figure 5, the application function device provided in this application embodiment can specifically be a network element in the core network of a satellite communication system. However, it is not limited to this; the application function device in this application embodiment can also be an IMS in a 4G communication system, an AF in a 5G communication system, or other network elements as the standard evolves. The management function device provided in this application embodiment can specifically be a network element in the core network of a satellite communication system. However, it is not limited to this; the management function device in this application embodiment can also be an IMS in a 4G communication system, an AF in a 5G communication system, or other network elements as the standard evolves.

[0259] The following section describes the interaction process between the application function devices and the management function devices included in this communication system.

[0260] It should be understood that the following description uses different communication devices as examples to illustrate the method, but this application does not limit the execution subject of the interaction. For example, the application function device and management function device shown in Figures 6 to 8 can be communication devices, or some components of communication devices (e.g., chips, baseband chips, modem chips, SoC chips containing modem cores, SIP chips, communication modules, chip systems, processors, logic modules, or software, etc.).

[0261] Please refer to Figure 6. An embodiment of this application provides a communication method, which mainly includes the following steps:

[0262] 601. The management function device sends a first message to the application function device. Correspondingly, 602. The application function device receives the first message from the management function device.

[0263] The first message is used to indicate the reachability status of the first terminal device. The reachability status of the first terminal device includes whether the first terminal device is reachable or unreachable. For example, the first message may be a status indication message, which can indicate the reachability status of the first terminal device. Alternatively, the first message may be a notification message, which can indicate the reachability status of the first terminal device. Or, the first message may be a subscription notification, which can indicate the reachability status of the first terminal device.

[0264] For example, if the first terminal device is in an unreachable state, the management function device can send a first message to the application function device, causing the application function device to determine that the first terminal device is unreachable based on the first message received. Alternatively, if the first terminal device is in a reachable state but the management function device does not send a first message to the application function device, the application function device can determine that the first terminal device is reachable based on not receiving the first message.

[0265] Optionally, the first message includes a first field, which is used to indicate the reachability status of the first terminal device.

[0266] Specifically, the management function device can generate a first message based on the reachability status of the first terminal device. This first message includes a first field. The management function device sends this first message, also including the first field, to the application function device. The application function device determines the reachability status of the first terminal device based on the indication of this first field. In this embodiment, the first field included in the first message enables the management function device to indicate the reachability status of the first terminal device to the application function device.

[0267] In some embodiments of this application, the first message is used to indicate the reachability status of the first terminal device, including:

[0268] The first message is used to indicate that the first terminal device is in an idle state, or to indicate that the first terminal device has entered an idle state.

[0269] The management function device can determine the reachability status of the first terminal device based on the context of the first terminal device. The management function device can determine that the first terminal device is in an idle state or that the management function device has entered an idle state. Based on whether the first terminal device is in an idle state or has entered an idle state, the management function device generates a first message and sends the first message to the application function device so that the application function device can determine that the first terminal device is unreachable based on the first message.

[0270] In some embodiments of this application, in step 601, the management function device sends a first message to the application function device, and the first message is also used to request first information.

[0271] In this embodiment, the first message sent by the management device can also be used to request first information. The application device can receive the first message and send the first information to the management device based on the first message, so that the management device receives the first information. In this application embodiment, the management device can request first information through the first message, the application device can send the first information according to the request of the management device, and the management device can actively request to receive the first information.

[0272] In this embodiment of the application, the first information sent by the management function device is used to identify the service. The service can be represented by one or more of the following: access network name or data network name, slice, service type, service identifier, sender information, cause value, etc.

[0273] The first piece of information includes at least one of the following: service type, service identifier, or sender.

[0274] The first information can be used to represent a service. Specifically, the first information can be at least one of the following: service type, service identifier, or sender. The first information can be sent from the application function device to the management function device, so that the management function device receives the first information and obtains at least one of the following: service type, service identifier, or sender.

[0275] There are various ways to implement the first information, which is related to the content of the service received by the application function device. Specifically, the first information can be service information, which describes the service. In other words, the first information represents the service. For example, the first information can include at least one of the following:

[0276] a) The first piece of information is the access network name or data network name. This name identifies the network and corresponds to the APN in Figure 2, or the DNN in Figure 1.

[0277] b. The first piece of information is the slice, which can be represented by a single network to assist in selecting the slice information.

[0278] c. The first piece of information is the service type. The service type describes the type of service. For example, the service type can include at least one of the following: IMS service, Local Area Network (LAN) service, server service, etc. Server services can include various services such as video services and browser services.

[0279] d. The first piece of information is the business identifier. The business identifier can be represented by a business domain name, a business ID, or an Internet Protocol (IP) triple or quintuple.

[0280] For example, an IP 5-tuple includes the source IP address, destination IP address, protocol used, source port number, and destination port number.

[0281] For example, an IP triple includes the source IP address, the destination IP address, and the protocol used.

[0282] For example, the service identifier for IMS services can be service ID1, and the service identifier for LAN services can be service ID2, etc.

[0283] e. The first piece of information is the sender information. Sender information indicates the source of the service. It can be the application function device itself, the calling number, the calling number index, the source IP address, the source port number, etc. For example, as shown in Figure 4, the calling UE's number is the sender information.

[0284] f. The first piece of information is the cause value, which indicates why the application function device sends downlink data. For example, the cause value indicates that the mobile network operator (MNO) needs to send downlink data to the called UE, or that the calling UE1 is looking for the called UE2. Alternatively, the cause value indicates that the server needs to proactively push data to the UE; for example, this server could be an advertising push server.

[0285] In some embodiments of this application, the communication method executed by the application function device and the management function device may further include the following:

[0286] A1. The application function device sends the first subscription message to the management function device. Correspondingly, B1. The management function device receives the first subscription message sent by the application function device.

[0287] The first subscription message is used to subscribe to the reachability status of the first terminal device.

[0288] It is understandable that the first terminal device refers to the terminal device served by the application function device. For example, if the first terminal device registers with the application function device through the application layer, then the first terminal device is a terminal device served by the application function device. As another example, if the destination address of data received or sent by the application function device is the first terminal device, then the first terminal device is a terminal device served by the application function device.

[0289] The application function device can subscribe to the reachability status of the first terminal device. For example, the application function device sends a first subscription message to the management function device. There are no restrictions on the information interaction method between the application function device and the management function device. For example, the application function device can be IMS or AF, etc. The application function device can send the first subscription message to the management device through an intermediate network element, as shown in Figure 2. The intermediate network element can be PCRF, or, as shown in Figure 1, the network element can be PCF and NEF.

[0290] The first terminal device can be the called UE shown in Figure 4. The reachability state of the first terminal device can include whether the first terminal device is reachable or unreachable. For example, if the first terminal device is in a connected state, then the first terminal device is reachable. If the first terminal device is in an idle state or enters an idle state, then the first terminal device is unreachable.

[0291] It should be noted that the reachability status of the first terminal device can be replaced with "Paging the first terminal device failed." That is, the first subscription message is used to subscribe to "Paging the first terminal device failed." This can be understood as meaning that the management function device received the downlink data notification and attempted to page the first terminal device, but the pageing was unsuccessful.

[0292] In some embodiments of this application, step A1, where the application function device sends a first subscription message to the management function device, includes:

[0293] A11. The application function device sends a first subscription message to the management function device based on the second information;

[0294] The second information includes at least one of the following: target service type, target service identifier, target sender information, and target access network type.

[0295] The application function device can determine whether to send the first subscription message based on the second information. The second information can be described as a service requirement, such as including at least one of the following: target service type, target service identifier, target sender information, and target access network type. The application function device sends the first subscription message only if the second information is satisfied; otherwise, it does not send it. Therefore, in this embodiment, the reachability status of the first terminal device can be used to subscribe to services that meet the second information, achieving highly reliable transmission for services that meet the second information.

[0296] For example, the second information includes the target service type. The service type describes the type of service, and can include at least one of the following: IMS service, LAN service, server service, etc. The target service type can be one or more specific service types; for example, the target service type could be a server service. Assuming the service types provided by the application function device include service type 1, service type 2, and service type 3, and assuming the target service type is service type 1, then the application function device's service type 1 is the same as the target service type, and the application function device can send a first subscription message to the management function device. Further assuming the target service type is service type 4, and the application function device's service types include service type 1, service type 2, and service type 3, then the target service type 4 does not belong to the service types provided by the application function device, and the application function device does not send a first subscription message to the management function device.

[0297] For example, the second information includes the target service identifier. This service identifier can be represented by a service domain name, a service identity identifier (ID), or an IP triplet or IP quintuple. Assume the services provided by the application function device correspond to service identifiers a, b, and c. If the target service identifier is service identifier a, then the application function device can send a first subscription message to the management function device, as the application function device's service identifier a is the same as the target service identifier. If the target service identifier is service identifier d, then the target service identifier does not belong to the service identifier corresponding to the service provided by the application function device, and the application function device will not send a first subscription message to the management function device.

[0298] For example, the second information includes target sender information. Sender information indicates the source of the service; it can be the application function device itself, the calling number, a calling number index, a source IP address, a source port number, etc. For instance, if the service provided by the application function device corresponds to sender ID1, sender ID2, and sender ID3, and the target sender information is sender ID1, the application function device can send the first subscription message; if the target sender is sender ID4, the application function device will not send the first subscription message to the management function device. Specifically, for the example shown in Figure 4, the IMS, based on information in the SIP signaling (i.e., SIP INVITE), such as the calling number 123, the called number 456, and the second information, determines that the calling number 123 needs to be sent to the called UE. If the second information is the calling number 123, that is, only if the sender is the calling number 123, the IMS sends the first subscription message to the MME; for other calling numbers whose sender is not the calling number 123, the IMS does not send the first subscription message to the MME.

[0299] For example, the second information includes the target access network type. The access network type refers to the type of network the first terminal device accesses. The access network type can be a terrestrial access network or a satellite access network. The access network type can be the access network name or the data network name, for example, a name used to identify the network, corresponding to the APN in the communication system of Figure 2, or the DNN in the communication system of Figure 1. For example, if the first terminal device accesses a satellite communication system, or if the first terminal device accesses a network via satellite, assuming the target access network type is a satellite access network, the application function device sends a first subscription message to the management function device. If the target access network type is a terrestrial access network, since the first terminal device accesses a satellite network, the application function device does not send a first subscription message to the management function device.

[0300] Through the above description of the specific implementation of A11, in this embodiment of the application function device, the first subscription message can be sent according to the second information to obtain the reachability status of the first terminal device. The application function device only sends the first subscription message to the management function device when the second information is satisfied. Therefore, the number of times the first subscription message is sent can be reduced, and the signaling overhead of the application function device can be saved.

[0301] In some embodiments of this application, step A11, where the application function device sends a first subscription message to the management function device based on the second information, includes:

[0302] A111. The application function device sends a first subscription message to the management function device according to the configuration information of the application function device. The configuration information of the application function device is used to indicate at least one of the following: the service served by the application function device is the target service type, the service served by the application function device is the target service identifier, the terminal device served by the application function device is the target sender, or the service served by the application function device accesses the network through the target access network type.

[0303] The application function device can also determine, based on its configuration information, whether the service it serves is the target service type, or whether the service it serves has a target service identifier, or whether the terminal device it serves is the target sender, or whether the service it serves accesses the network through the target access network type, and then send a first subscription message to the management function device. For example, if an application managed by the application function device (e.g., a specific application (APP) or voice service) is the target service, the application function device determines, based on its configuration information, that a first subscription message needs to be sent. Alternatively, an application function device may serve only one application, and the service corresponding to that application is the target service; in this case, the application function device determines that a first subscription message needs to be sent.

[0304] In this embodiment, the configuration information of the application function device can indicate whether to send a first subscription message to the management function device. When the configuration information indicates that the service provided by the application function device is the target service, the application function device sends a first subscription message to the management function device. When the first terminal device is unreachable, the application function device sends first information to the management function device. The paging message sent by the management function device to the first terminal device contains the first information. The first terminal device determines whether to access the network based on the obtained first information, and determines whether to restore the user plane connection, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0305] In some embodiments of this application, the first subscription message sent by the application function device includes at least one of the following: target service type, target service identifier, target sender, or target access network type.

[0306] The first subscription message sent by the application function device may include at least one of the following: target service type, target service identifier, target sender, or target access network type. Correspondingly, the management function device receives the first subscription message; the management function device receives a downlink data notification message from the user plane function device, which indicates the arrival of downlink data; the management function device determines whether to send the reachability status of the first terminal device to the application function device based on the first subscription message and the downlink data. If the service corresponding to the downlink data matches the first subscription message, the management function device sends the reachability status of the first terminal device to the application function device; if the service corresponding to the downlink data does not match the first subscription message, the management function device does not send the reachability status of the first terminal device to the application function device. In this embodiment, the management function device can receive the first subscription message from the application function device, and can also obtain at least one of the following from the first subscription message: target service type, target service identifier, target sender, or target access network type. Based on the matching of at least one of the following: target service type, target service identifier, target sender, or target access network type with the service corresponding to the downlink data, the number of times the management function device sends the reachability status is reduced, saving the signaling overhead of the management function device.

[0307] For example, if the sender of the service corresponding to the downlink data is UE1, and the first subscription message includes UE1 as the target sender, then it can be understood that the service corresponding to the downlink data matches the first subscription message. Conversely, if the sender of the service corresponding to the downlink data is UE3, and the first subscription message includes UE1 as the target sender, then it can be understood that the service corresponding to the downlink data does not match the first subscription message.

[0308] Furthermore, step A111 performed in the embodiments of this application may include the following steps:

[0309] A1111. Before the application function device receives or sends the target service, the application function device sends a first subscription message to the management function device according to the configuration information of the application function device.

[0310] It is understood that "before receiving or sending the target service" in step A1111 above can be replaced with "before the target service begins," or "the user / terminal device registers with the application function device." Here, "sending the target service" refers to the application function device sending the target service to the user function device. "Receiving the target service" refers to the application function device receiving the target service sent by other terminal devices besides the first terminal device. The destination address of the target service sent by the other terminal devices is the address of the first terminal device; for example, the other terminal devices refer to the calling UE, and the first terminal device refers to the called UE.

[0311] In this embodiment, the application function device can send a first subscription message to the management function device according to the configuration information of the application function device before receiving or sending the target service. It is not necessary to determine whether to send the first subscription message to the management function device based on the target service to be received or sent, which simplifies the way the application function device sends the first subscription message.

[0312] As illustrated in Figure 4, before the service begins, the AF can send a first subscription message to the MME based on its configuration information. Taking the first terminal device as the called UE as an example, if the called UE registers with the AF through the application layer, the AF determines, based on its configuration information, whether it needs to send first information to the MME for the called UE or needs to subscribe to the called UE's status information. In this case, the AF sends a first subscription message to the MME.

[0313] In some embodiments of this application, step 601, where the management function device sends a first message to the application function device, includes:

[0314] C1. The management function device determines whether to allow the first terminal device to use the target service based on the third information, which includes at least one of the following: the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device;

[0315] C2. When the first terminal device is allowed to use the target service, the management function device sends the first message to the application function device.

[0316] Before sending the first message to the application function device, the management function device needs to determine whether to allow the first terminal device to use the target service.

[0317] The target service refers to a high-reliability service, which can also be described as a service that requires sending initial information to the terminal device. A specific target service can be represented by one or more of the following: access network name or data network name, network slice, service type, service identifier, sender information, etc. High-reliability services can also be called resilient notification services or paging alert services.

[0318] Step C1, allowing the first terminal device to use the target service, may specifically include: allowing the first terminal device to use the target service when accessing a network of the target access network type.

[0319] For example, if the first terminal device accesses a satellite communication system, or if the first terminal device accesses a network via a satellite, and assuming that the target access network type includes satellite access network type, the management function device sends a first message to the application function device.

[0320] Specifically, the management function device can determine whether to allow the first terminal device to use the target service based on third information. This third information can be implemented in various ways and includes at least one of the following: the first terminal device's subscription information, the policy information of the policy control device, or the configuration information of the management function device. If the first terminal device is allowed to use the target service, the management function device can send a first message to the application function device, thus reducing the number of times the management function device sends reachability status messages and saving signaling overhead.

[0321] For example, when a first terminal device registers or attaches to a network, it can obtain its subscription information from a subscription database. This subscription information can indicate whether the first terminal device can use the target service. The subscription database can be the HSS in the communication system shown in Figure 2, or the UDM in the communication system shown in Figure 1.

[0322] For example, the policy control device can provide policy information to the management function device. The management function device determines whether to allow the first terminal device to use the target service based on the policy information from the policy control device. The policy control device provided in this application embodiment can generate policy information for the target service, such as allowing the first terminal device to use the target service. Specifically, the policy control device provided in this application embodiment can be the PCRF in the communication system shown in Figure 2, or the PCF in the communication system shown in Figure 1. It is not limited, but the policy control device in this application embodiment can also be a network element in the core network of the communication system shown in Figures 3a and 3b. This is not limited here.

[0323] For example, the management function device can use its configuration information to determine whether to allow the first terminal device to use the target service. The configuration information for the target service provided in this application embodiment can be configured on the management function device by the network management system. For example, the configuration information of the management function device includes allowing the first terminal device to use the target service.

[0324] In some embodiments of this application, the first subscription message includes at least one of the following: target service type, target service identifier, target sender information, or target access network type;

[0325] Step 601: The management function device sends a first message to the application function device, including:

[0326] D1. The management function device receives a downlink data notification message from the user function device. The downlink data notification message is used to indicate that downlink data has arrived. The downlink data is the data sent to the first terminal device.

[0327] D2. The management function device determines whether the service corresponding to the downlink data matches the first subscription message;

[0328] D3. When the service corresponding to the downlink data matches the first subscription message, the management function device sends the first message to the application function device.

[0329] Specifically, the application function device includes at least one of the following in the first subscription message: target service type, target service identifier, target sender information, or target access network type. Correspondingly, the management function device receives the first subscription message; the management function device receives a downlink data notification message from the user plane function device, which indicates the arrival of downlink data; the management function device determines whether to send the reachability status of the first terminal device to the application function device based on the third information and the downlink data. If the service corresponding to the downlink data matches the third information, the management function device sends the reachability status of the first terminal device to the application function device; if the service corresponding to the downlink data does not match the first subscription message, the management function device does not send the reachability status of the first terminal device to the application function device. In this embodiment, the management function device can receive the first subscription message from the application function device. The management function device can also obtain at least one of the following from the first subscription message: target service type, target service identifier, target sender information, or target access network type. Based on the matching of at least one of the following: target service type, target service identifier, target sender information, or target access network type with the service corresponding to the downlink data, the number of times the management function device sends the reachability status is reduced, saving the signaling overhead of the management function device.

[0330] In some embodiments of this application, step 601, in which the management function device sends a first message to the application function device, further includes:

[0331] E1. The management function device receives a downlink data notification message from the user function device. The downlink data notification message is used to indicate that downlink data has arrived. The downlink data is the data sent to the first terminal device.

[0332] E2. The management function device determines, based on the downlink data notification message, whether the service corresponding to the downlink data is the target service, or whether it is the target service type, or whether it comes from the target sender, or whether the downlink data is accessed through the target access network type.

[0333] E3. When the downlink data corresponds to the target service, or is a target service type, or comes from the target sender, or the downlink data accesses the network through the target access network type, the management function device sends the first message to the application function device.

[0334] In this embodiment, the user function device can generate a downlink data notification message based on the downlink data, indicating that the downlink data has arrived. Specifically, the user function device provided in this application embodiment can be the SGW shown in Figure 2 or the UPF shown in Figure 1. However, it is not limited to any particular type; the user function device in this application embodiment can also be a network element in the core network shown in Figures 3a and 3b. For example, as shown in Figure 4, the user function device is specifically an SGW. The SGW can receive downlink data from the IMS through the PGW, and the SGW generates a downlink data notification message based on the downlink data.

[0335] After receiving a downlink data notification message, the user function device sends a downlink data notification message to the management function device. This message indicates that downlink data has arrived. The management function device determines whether the service corresponding to the downlink data is a target service, a target service type, originates from a target sender, or accesses the network via a target access network type. If the service corresponding to the downlink data is a target service, a target service type, originates from a target sender, or accesses the network via a target access network type, the management function device sends a first message to the application function device. If the service corresponding to the downlink data is not a target service, a target service type, originates from a target sender, or accesses the network via a target access network type, the management function device does not send a first message to the application function device. In this embodiment, the management function device sends a first message to the application function device only if the service corresponding to the downlink data is a target service, a target service type, originates from a target sender, or accesses the network via a target access network type. This reduces the number of times the management function device sends reachability status messages, saving signaling overhead.

[0336] For a description of the target service type, target service, target sender, and target access network type, please refer to the description in the aforementioned A11 embodiment.

[0337] In this embodiment of the application, the management function device can send a first message to the application function device when the service corresponding to the downlink data is the target service, the service corresponding to the downlink data is the target service type, the downlink data comes from the target sender, or the downlink data accesses the network through the target access network type. This triggers the application function device to send first information to the management function device. For example, the management function device includes the first information in the paging message sent to the first terminal device, so that the paging first terminal device can determine whether to access the network based on the first information, and determine whether to restore the user plane connection, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0338] It is understood that in the above embodiments, in steps E1 to E3, a first message is sent based on whether the service corresponding to the downlink data is the target service, or the service corresponding to the downlink data is the target service type, or the downlink data originates from the target sender, or the downlink data accesses the network through the target access network type. Steps E1 to E3 can be completed as a separate embodiment, or steps E1 to E3 can be completed together with the embodiment consisting of steps C1 to C2. When the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device allows the first terminal device to use the target service, and the service corresponding to the downlink data is the target service, or the service corresponding to the downlink data is the target service type, or the downlink data originates from the target sender, or the downlink data accesses the network through the target access network type, the application management function device sends a first message to the management function device.

[0339] 603. If the first message indicates that the first terminal device is unreachable, the application function device sends a first message to the management function device. Correspondingly, 604. The management function device receives the first message sent by the application function device.

[0340] The first piece of information is used by the first terminal device to determine whether to access the network.

[0341] In the event that the first terminal device is unreachable, the application function device can send a first message to the management function device. In this embodiment, in response to the first terminal device being unreachable, the application function device can send a first message to the management function device. Upon receiving this first message, the management function device includes the first message in a paging message sent to the first terminal device. This allows the paged first terminal device to determine whether to access the network based on the first message, thereby determining whether to restore the user plane connection, thus avoiding wasted transmission resources and reducing the power consumption of the terminal device.

[0342] The first information provided in this application embodiment can be applied to scenarios of high-reliability services, which can also be called resilient notification services or paging alert services. The paging message sent by the management function device to the first terminal device can be an enhancement of a normal paging message. The paging message sent by the management function device to the first terminal device can be a paging message re-initiated after paging of the first terminal device fails.

[0343] In some embodiments of this application, step 602, where the application function device sends first information to the management function device, includes:

[0344] F1. The application function device sends a business information notification message to the management function device. The business information notification message includes the first information.

[0345] In this embodiment, the application function device can interact with the management function device. The application function device generates a business information notification message, which carries first information. The application function device sends this business information notification message to the management function device, allowing the management function device to receive the message, parse it, and obtain the first information. This application does not limit the specific method by which the application function device sends the first information; existing signaling between the application function device and the management function device, or newly defined signaling, can be used to carry the first information.

[0346] In some embodiments of this application, the first information is included in a paging message sent by the management function device to the first terminal device.

[0347] Specifically, the application function device can send first information, which the management function device can receive. After receiving the first information, the management function device sends a paging message to the first terminal device. The paging message includes the first information, so that the paged first terminal device can determine whether to access the network based on the first information, and determine whether to restore the user plane connection, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0348] Please refer to Figure 7. An embodiment of this application provides a communication method, which mainly includes the following steps:

[0349] 701. The user function device sends a downlink data notification message to the management function device. Correspondingly, 702. The management function device receives the downlink data notification message from the user function device.

[0350] The downlink data notification message is used to indicate that downlink data has arrived, and the downlink data is the data sent to the first terminal device.

[0351] User function devices can generate downlink data notification messages based on downlink data, which indicate the arrival of downlink data. After receiving the downlink data notification message, the user function device sends a downlink data notification message to the management function device, which then determines that the downlink data has arrived based on this message.

[0352] For the descriptions of steps 701 and 702 regarding user function devices, management function devices, downlink data notification messages, and downlink data arrival, please refer to the descriptions of steps D1 to D3 and E1 to E3 in the aforementioned embodiments; they will not be described in detail here.

[0353] 703. The management function device sends the fourth information to the application function device based on the downlink data notification message. Correspondingly, 704. The application function device receives the fourth information from the management function device.

[0354] The fourth information is used to obtain the first information corresponding to the downlink data, and the first information is used by the first terminal device to determine whether to access the network.

[0355] After receiving the downlink data notification message, the management function device can determine that there is downlink data that needs to be sent. The management function device sends the fourth information to the application function device according to the downlink data notification message. The fourth information is used to obtain the first information corresponding to the downlink data. There are multiple ways for the management function device to send the fourth information. For example, the fourth information can be used to request the first information from the application function device, or the fourth information can be the reachability status of the first terminal device, and the application function device sends the first information according to the reachability status of the first terminal device.

[0356] It is understandable that the fourth information can be replaced by a fourth message, that is, the fourth message is used to obtain the first information corresponding to the downlink data, or the fourth information is used to indicate the reachability status of the first terminal device. Optionally, the fourth information includes the reachability status of the first terminal device.

[0357] In some embodiments of this application, step 703, the management function device sends fourth information to the application function device based on the downlink data notification message, including:

[0358] G1. The management function device sends the fourth information to the application function device based on the service corresponding to the downlink data as the target service type.

[0359] or,

[0360] G2. The management function device sends the fourth information to the application function device based on the service corresponding to the downlink data as the target service.

[0361] or,

[0362] G3. The management function device sends the fourth information to the application function device based on the fact that the downlink data corresponds to the service originating from the target sender.

[0363] or,

[0364] G4. The management function device accesses the network according to the target access network type based on the downlink data and sends the fourth information to the application function device.

[0365] Specifically, the management function device determines that the service corresponding to the downlink data is a target service type, or that the service corresponding to the downlink data originates from a target sender, or that the service corresponding to the downlink data is a target service, or that the downlink data accesses the network through a network corresponding to a target access network type. For a description of the target service type, target service, target sender, and target access network type, please refer to Figure 6 and the description in the aforementioned embodiment A1; it will not be repeated here. When the service is a target service type, or originates from a target sender, or is a target service, or the downlink data accesses the network through a target access network type, the management function device sends fourth information to the application function device, thereby enabling the application function device to obtain the fourth information. This reduces the number of times the fourth information is sent, saving the signaling overhead of the management function device.

[0366] In some embodiments of this application, step 703, the management function device sends fourth information to the application function device based on the downlink data notification message, including:

[0367] H1. The management function device determines whether to allow the first terminal device to use the target service based on the third information, which includes at least one of the following: the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device.

[0368] H2. When the first terminal device is allowed to use the target service, the management function device sends the fourth information to the application function device according to the downlink data notification message.

[0369] The descriptions of the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device are detailed in the embodiments shown in C1 and C2 above and Figure 6, and will not be repeated here. When the first terminal device is allowed to use the target service, the management function device sends the fourth information to the application function device according to the downlink data notification message, so that the application function device can obtain the fourth information. Therefore, the number of times the fourth information is sent can be reduced, and the signaling overhead of the management function device can be saved.

[0370] In some embodiments of this application, step 703, the management function device sends fourth information to the application function device based on the downlink data notification message, including:

[0371] H3. The management function device sends a fourth message to the application function device based on the downlink data notification message. The fourth message includes a second field, which is used to indicate the reachability status of the first terminal device.

[0372] Specifically, the management function device can send a fourth message to the application function device. This fourth message includes a second field, which indicates the reachability status of the first terminal device. This allows the application function device to obtain the reachability status of the first terminal device based on the second field in the fourth message. The application function device then sends the first message based on the reachability status of the first terminal device, thus reducing the number of times the first message is sent and saving the signaling overhead of the application function device.

[0373] In some embodiments of this application, the second field is used to indicate the reachability status of the first terminal device, including:

[0374] The second field is used to indicate whether the first terminal device is in an idle state or whether the first terminal device has entered an idle state.

[0375] Specifically, if the management device determines that the first terminal device is in an idle state, it can configure the second field in the fourth information based on the first terminal device being in an idle state. Alternatively, if the management device determines that the first terminal device has entered an idle state (e.g., the first terminal device switches from a connected state to an idle state), it can configure the second field in the fourth information based on the first terminal device entering an idle state, thereby enabling the management device to indicate the reachability status of the first terminal device to the application device.

[0376] In some embodiments of this application, step 703, the management function device sends fourth information to the application function device based on the downlink data notification message, including:

[0377] H4. The management function device sends the fourth information to the application function device based on the downlink data notification message. The fourth information includes the third field, which is used to request the first information corresponding to the downlink data from the application function device.

[0378] The downlink data notification message is sent from the user plane function device to the management function device, indicating the arrival of downlink data. The fourth information is used to obtain the first information corresponding to the downlink data. The management function device can request the first information from the application function device, which then sends the first information, enabling the management function device to obtain it. Specifically, the management function device can send the fourth information, which includes a third field. This third field can be a request field, used to request the first information corresponding to the downlink data from the application function device. The application function device sends the first information to the management function device based on the third field included in the fourth information.

[0379] In some embodiments of this application, the communication method executed by the application function device, in addition to the aforementioned step 704, may further include the following steps:

[0380] I1. Application function devices send downlink data to user function devices, and user function devices send downlink data notification messages to management function devices.

[0381] After acquiring downlink data, the application function device can send downlink data to the user function device. The user function device can generate a downlink data notification message based on the downlink data. The downlink data notification message is used to indicate that there is downlink data to be sent to the first terminal device.

[0382] 705. The application function device sends the first information to the management function device based on the fourth information. Correspondingly, 706. The management function device receives the first information from the application function device.

[0383] The application function device can send first information to the management function device. The management function device receives the first information and uses it to determine whether the first terminal device should access the network. This allows the paged first terminal device to determine whether to access the network based on the first information, and to determine whether to restore the user plane connection, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0384] In some embodiments of this application, the first information is included in a paging message sent by the management function device to the first terminal device.

[0385] Specifically, the application function device can send first information, which the management function device can receive. After receiving the first information, the management function device sends a paging message to the first terminal device. The paging message includes the first information, so that the paged first terminal device can determine whether to access the network based on the first information, and determine whether to restore the user plane connection, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0386] Please refer to Figure 8. An embodiment of this application provides a communication method, which mainly includes the following steps:

[0387] 801. In response to the network access request from the first terminal device, the management function device sends a second subscription message to the application function device. Correspondingly, 802. The application function device receives the second subscription message from the management function device.

[0388] The second subscription message is used to subscribe to the first information of the first terminal device, and the first information is used by the first terminal device to determine whether to access the network.

[0389] Specifically, when the first terminal device needs to access the network, the first terminal device can send a network access request. For example, when the first terminal device is powered on, the first terminal device can send a network access request. In response to the network access request of the first terminal device, the management function device sends a second subscription message to the application function device to subscribe to the first information that needs to be sent to the first terminal device.

[0390] It is understandable that the network access request can also be replaced by other request messages sent by the first terminal device, such as service requests, tracking area registration update requests, mobility registration update requests, etc.

[0391] For example, as shown in Figure 4, the first terminal device is the called UE. The called UE initiates the registration process. Specifically, the called UE sends a registration request to the MME. After receiving the registration request, the MME can send a second subscription message to the IMS. The second subscription message is used to subscribe to the first information of the called UE.

[0392] The application function device interacts with the management function device. Upon receiving a second subscription message, the application function device determines, based on this message, the first information that needs to be subscribed to from the first terminal device. For example, as shown in Figure 4, the application function device can be an IMS. The IMS receives the second subscription message from the MME and determines that it needs to subscribe to the first information of the called UE.

[0393] In some embodiments of this application, step 801, where the management function device sends a second subscription message to the application function device, includes:

[0394] J1. The management function device determines whether to allow the first terminal device to use the target service based on the third information, which includes at least one of the following: the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device.

[0395] J2. When the first terminal device is allowed to use the target service, the management function device sends a second subscription message to the application function device.

[0396] The details of the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device are described in C1 and C2 above and in the embodiments shown in Figure 6, and will not be repeated here. When the first terminal device is allowed to use the target service, the management function device sends a second subscription message to the user device, so that the management function device can obtain the first information according to the second subscription message and realize the high-reliability transmission of the first information.

[0397] In some embodiments of this application, step 801, where the management function device sends a second subscription message to the application function device, includes:

[0398] K1. The management function device receives downlink data notification messages from the user function device;

[0399] K2. The management function device sends a second subscription message to the application function device based on the downlink data notification message. The second subscription message includes a fourth field, which is used to request the application function device to send the first information.

[0400] Specifically, the management function device can send a second subscription message to the application function device based on the downlink data notification message. The management function device can configure a fourth field of the second subscription message and request the application function device to send first information through this fourth field. This allows the application function device to obtain the fourth field of the second subscription message and send the first information to the management function device based on this fourth field. Therefore, the number of times the first information is sent can be reduced, saving the signaling overhead of the application function device.

[0401] In some embodiments of this application, the management function device sends a second subscription message to the application function device, including:

[0402] L1. The management function device receives downlink data notification messages from the user function device;

[0403] L2, the management function device determines whether the service corresponding to the downlink data is the target service, or whether the service corresponding to the downlink data is the target service type, or whether the service corresponding to the downlink data comes from the target sender, or whether the downlink data is accessed through the target access network type;

[0404] L3. When the service corresponding to the downlink data is the target service, or the corresponding service is not the target service type, or the service corresponding to the downlink data comes from the target sender, or the downlink data is accessed through the target access network type, the management function device sends a second subscription message to the application function device.

[0405] For an explanation of the target service type, target service, and target sender, please refer to Figure 6 and the description in the aforementioned embodiment A11. When the service corresponding to the downlink data is the target service, or the corresponding service is not the target service type, or the service corresponding to the downlink data comes from the target sender, or the downlink data accesses the network through the target access network type, the management function device sends the first information to the application function device to achieve highly reliable transmission for the target service.

[0406] 803. The application function device sends the first information to the management function device according to the second subscription message. Correspondingly, 804. The management function device receives the first information sent by the application function device.

[0407] In order to ensure highly reliable transmission of the first information, the application function device responds to the second subscription message. After obtaining the first information, the application function device can send the first information to the management function device. In this embodiment, the application function device can send the first information to the management function device in response to the second subscription message. Upon receiving the first information, the management function device enables the paged first terminal device to determine whether to access the network based on the first information, thereby determining whether to restore the user plane connection, thus avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0408] In some embodiments of this application, step 803, where the application function device sends first information to the management function device based on the second subscription message, includes:

[0409] M1. The application function device receives a second message sent by the management function device. The second message is used to request the application function device to send the first information.

[0410] M2, the application function device sends the first information to the management function device based on the second subscription message and the second message.

[0411] In order to receive the first information as soon as possible, the management function device can also generate a second message. The first message is used to request the application function device to send the first information. The application function device sends the first information to the management function device according to the second message, so that the management function device can receive the first information in a timely manner.

[0412] In some embodiments of this application, step 804, where the management function device receives first information sent by the application function device, includes:

[0413] N1. The management function device receives downlink data notification messages from the user function device;

[0414] N2. After a preset time, the management function device receives the first information sent by the application function device. The preset time starts from the time the downlink data notification message is received.

[0415] In this embodiment, the management device receives downlink data notification messages from the user device. If the management device receives the downlink data notification message before receiving the first information, it needs to wait for a preset time after receiving the downlink data notification message. The preset time begins when the downlink data notification message is received. After the preset time, the management device receives the first information sent by the application device. In this embodiment, the management device waits for the preset time before receiving the first information to ensure that the first information is received.

[0416] In some embodiments of this application, the method performed by the application function device includes, in addition to the steps described above, the method provided in the embodiments of this application further includes:

[0417] P1. The application function device sends downlink data to the user function device. The downlink data is used by the user function device to send the downlink data notification message to the management function device.

[0418] After acquiring downlink data, the application function device can send downlink data to the user function device. The user function device can generate a downlink data notification message based on the downlink data. The downlink data notification message is used to indicate that there is downlink data to be sent to the first terminal device.

[0419] In some embodiments of this application, the first information is included in a paging message sent by the management function device to the first terminal device.

[0420] Specifically, the application function device can send first information, which the management function device can receive. After receiving the first information, the management function device sends a paging message to the first terminal device. The paging message includes the first information, so that the paged first terminal device can determine whether to access the network based on the first information, and determine whether to restore the user plane connection, thereby avoiding waste of transmission resources and reducing the power consumption of the terminal device.

[0421] It is understood that the interaction methods between the application function devices and the management function devices involved in the embodiments shown in Figures 7 and 8, the definitions of the application function devices and the management function devices, and the meanings of technical terms such as first information, third information, reachability status, service, service identifier, service type, sender, access network type, downlink data, subscription information of the first terminal device, policy information of the policy control device, configuration information of the management function device, downlink data notification message, and paging message can all be referred to in the embodiments shown in Figure 6 above, and will not be elaborated further in the embodiments shown in Figures 7 and 8. The embodiments shown in Figures 6, 7, and 8 can be implemented in combination with each other or independently of each other, depending on the specific application, and are not limited here.

[0422] In addition, the second information in the embodiment corresponding to Figure 6 above is used by the application function device to determine to send a subscription message to the management function device. The second information includes at least one of the following: target service type, target service identifier, target sender information, and target access network type.

[0423] In the embodiment corresponding to Figure 7, the fourth information is sent by the management function device to the application function device. The function of the fourth information is to obtain the first information corresponding to the downlink data.

[0424] Furthermore, the first subscription message in the embodiment corresponding to Figure 6 of this application has a different meaning and function than the second subscription message in the embodiment corresponding to Figure 8. Specifically, in the embodiment corresponding to Figure 6, the first subscription message is sent by the application function device to the management function device, and this first subscription message is used to subscribe to the reachability status of the first terminal device. In contrast, in the embodiment corresponding to Figure 8, the second subscription message is sent by the application function device to the management function device, and this second subscription message is used to subscribe to the first information of the first terminal device.

[0425] In addition, the first message in the embodiment corresponding to FIG6 above has the same meaning and function as the notification message in the embodiment corresponding to FIG7. The first message is sent by the management function device to the application function device, and the first message is used to indicate the reachability status of the first terminal device.

[0426] In addition, the third information in the embodiment corresponding to Figure 6 of this application has the same meaning and function as the third information in the embodiment corresponding to Figure 7. The management function device determines whether to allow the first terminal device to use the target service based on the third information. The third information includes at least one of the following: the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device.

[0427] The following describes the embodiments of this application using the communication system architecture shown in the foregoing embodiments as an example, combined with detailed application scenarios. The detailed description is shown in Figures 9, 10 and 11. The embodiment shown in Figure 9 is an example of an application scenario of the embodiment shown in Figure 6, the embodiment shown in Figure 10 is an example of an application scenario of the embodiment shown in Figure 7, and the embodiment shown in Figure 11 is an example of an application scenario of the embodiment shown in Figure 8.

[0428] The following explanation will use IMS as the application function device, MME as the management function device, PCRF as the policy control device, and SGW and PGW as user function devices as examples.

[0429] Taking the IMS voice call process as an example, please refer to Figure 9 first. The process of AF subscribing to the reachable state of UE mainly includes the following steps:

[0430] S01. IMS needs to send the first information to the UE based on the service requirements.

[0431] The services can be IMS services, LAN services, server services (such as video services, browser services), etc.

[0432] The first piece of information can be the service type, the calling number, and the calling number index. Service types include IMS service, LAN service, and server service. Server service can be replaced with or further subdivided into: video service / browser service, etc.

[0433] For example, IMS determines whether to send the calling number to the called UE based on information in SIP signaling (i.e., SIP INVITE), such as the calling number, the called number, and configuration information.

[0434] Optionally, the IMS can perform this judgment upon receiving a service message (i.e., the service begins), i.e., execute step S01. Alternatively, the IMS can perform step S01 before the service begins, such as when the IMS performs this judgment based on its configuration information, for example, if the IMS manages multiple applications and determines that the first information needs to be sent to the UE when the application's service is the target service.

[0435] Not limited to this, in addition to determining whether to send the first information to the UE based on service needs, IMS can also determine whether to send the first information to the UE based on the type of network accessed by the UE, such as satellite communication systems.

[0436] S02-S03. IMS sends the first subscription message to the core network to subscribe to the reachability status of the called UE.

[0437] In this context, subscribing to the reachability state of the called UE can be subscribing to changes in the reachability state of the called UE. For example, the reachability state is when the UE enters the idle state, or the reachability state can be a state change from the connected state to the idle state.

[0438] For example, the core network could specifically be S03.IMS sending a subscription request to the MME via PCRF to subscribe to the UE reachability state.

[0439] S04. Optional, the reachability status of the called UE changes, and the UE enters the idle state, as in the S1 release procedure.

[0440] S05. The MME sends a status first message to the IMS. The first message is used to return the reachability status of the called UE. For example, the reachability status of the called UE can include the called UE being unreachable and the called UE being reachable.

[0441] Optionally, the MME only returns the reachability status of the called UE to the IMS if the called UE is permitted to use high-reliability paging. Specifically, the MME determines whether the called UE is permitted to use high-reliability services or access specific services, such as services requiring high-reliability paging, based on the called UE's subscription information, PCRF policy information, or MME configuration information. High-reliability paging services can include voice services, video services (or video services from a specific website), etc. Specific services can be represented by the Data Network Name (DNN) / Single Network Slice Selection Assistance Information (S-NSSAI).

[0442] For example, the MME can send the first message only if the UE is allowed to use high-reliability paging; for example, the first message could be a status notification message. The MME determines whether the UE (or the services that the UE is allowed to access) can use resilient notification based on the called UE's subscription information, PCRF policy information, or the MME's configuration information.

[0443] S06. The calling UE sends a Session Initiation Protocol Invitation Message (SIP INVITE) to the PGW and SGW, and the SGW sends a Session Initiation Protocol Invitation Message to the P-SCSF.

[0444] S07. Trigger the AAR / AAA procedure from P-CSCF to PCF.

[0445] The following describes the service message transmission process. For a detailed process, please refer to the embodiment description corresponding to Figure 4. Here, only the process related to the embodiment of this application is described:

[0446] S08-S09.P-CSCF sends a Session Initiation Protocol Invitation Message to the PGW and SGW.

[0447] In this process, the IMS receives service messages. Based on the fact that the called UE is unreachable according to the previous step S05, the IMS not only sends service messages to the PGW and SGW, but also executes step S10.

[0448] S10. IMS sends a service information notification message to the MME in the core network.

[0449] This service information notification message carries primary information. This primary information may include the service type, service IP triplet, service IP quintuple, and the corresponding DNN or S-NSSAI. For example, the service type may include video, voice, or application.

[0450] Steps S09 and S10 can be executed simultaneously, without any order.

[0451] S11.SGW sends a downlink data notification message (DDN) to MME.

[0452] Steps S10 and S11 may arrive at the MME sequentially.

[0453] S12. If step S10 reaches the MME first, the MME can directly initiate the paging process.

[0454] When the message reaches the MME after step S10, the MME needs to wait for a notification message before proceeding to the next step. Alternatively, if the MME determines that the downlink data corresponds to a specific service, it may wait for the notification message in step S10 or request or query the first information from the PCRF. Then, it initiates the paging process.

[0455] S13-S14. MME initiates paging process.

[0456] Specifically, the MME sends a paging message to the base station in the registered area, and then the base station sends a paging message to the UE. The paging message carries the first information.

[0457] It is understandable that the paging procedures in S13 and S14 can be either existing paging procedures or paging procedures re-initiated after an existing paging procedure has failed. For example, after a normal paging is identified in the existing mechanism, high-reliability paging can be used, and the channel design can be enhanced for this high-reliability paging.

[0458] As illustrated by the foregoing examples, in this embodiment, the AF subscribes to the UE's reachability status. When the UE is unreachable, the AF sends first information to the core network, thus enabling the core network to send first information to the UE. Based on this first information, the UE can decide whether to move to an open area to conduct corresponding service communication. When the UE moves to an open area, it determines whether to access the network, i.e., whether to restore the user plane connection.

[0459] Taking the IMS voice call process as an example, please refer to Figure 10 below. When downlink data arrives, the core network sends the UE reachability status to the AF, which mainly includes the following steps:

[0460] S21. The calling UE sends a session initiation protocol invitation message to the PGW or SGW.

[0461] S22. Trigger the AAR / AAA procedure from P-CSCF to PCF.

[0462] The following describes the service message transmission process. For a detailed process, please refer to the embodiment description corresponding to Figure 4. Here, only the process related to the embodiment of this application is described:

[0463] S23.P-CSCF sends a session initiation protocol invitation message to IMS.

[0464] S24.IMS sends an invitation message to the P-CSCF session initiation protocol.

[0465] S25.P-CSCF sends a Session Initiation Protocol Invitation Message to the PGW and SGW.

[0466] The session initiation protocol invitation message may include downlink data, which may also be referred to as a business message or a business.

[0467] If the called UE is in an idle state, perform the following steps:

[0468] S26.SGW sends a downlink data notification message to MME.

[0469] S27.MME determines that the downlink data corresponds to a specific service.

[0470] S27 can also be described as follows: The MME determines the arrival of the downlink data notification message for the AF subscription. That is, if the IMS has a need to notify the UE of the first information, the IMS triggers the subscription process, that is, the IMS subscribes to the core network for the UE reachability status.

[0471] Alternatively, S27 can also be described as: The MME determines that the called UE is allowed to use high-reliability services.

[0472] S28. MME sends UE reachability status to IMS.

[0473] Optionally, the MME sends an indication message to the IMS, which indicates the acquisition of the first information.

[0474] Additionally, S28 can also be described as the MME sending an acquisition request to the IMS to obtain first information.

[0475] S29.MME receives a message carrying first information sent by IMS.

[0476] S30.MME sends a paging message to the base station within the registered area, and the base station then sends a paging message to the UE. This paging message carries the first information.

[0477] The paging process in S30 can be an existing paging process or a paging process that is re-initiated after an existing paging process has failed.

[0478] In S30, paging refers to high-reliability paging, which is paging initiated after the MME paging UE fails, for example, if the MME paging UE fails after S27 or after S29.

[0479] S31.eNB sends a paging message to the called UE.

[0480] As can be seen from the foregoing examples, in this embodiment of the application, the MME obtains the first information from the AF in order to achieve the purpose of the core network sending the first information to the UE.

[0481] Taking the IMS voice call process as an example, please refer to Figure 11 below. During the UE registration process, the core network subscribes to the first information from the AF, which mainly includes the following steps:

[0482] S51. The called UE initiates an attach request.

[0483] Specifically, when the called UE initiates an attach request, it can mean that the called UE sends a registration request to the MME.

[0484] S52.MME determines that the UE is allowed to use elastic notifications.

[0485] S52 can also be described as follows: When a UE registers and joins the network, the MME determines whether to subscribe to the first information from the PCRF. If the subscription to the first information is allowed, step S53 is triggered, that is, the first information is subscribed to from the AF through the PCRF.

[0486] For example, the MME determines, based on the called UE's subscription information, PCRF policy information, and MME configuration information, whether the called UE is allowed to use high-reliability paging, elastic notification, or access a specific service.

[0487] S53.MME initiates a subscription message to IMS to subscribe to first information.

[0488] Next, the process of transmitting business messages will be explained.

[0489] S54-S57. IMS sends service messages.

[0490] S58.P-CSCF sends notification message 1 to PCRF, carrying the first information.

[0491] S59.PCRF sends notification message 2 to MME, carrying the first information.

[0492] S60 and P-CSCF send session initiation protocol invitation messages to PGW and SGW.

[0493] S61.SGW sends a DDN message to MME.

[0494] S62. If the notification message from S10 arrives at the MME later than the DDN, the MME will execute the following steps: It needs to wait for the notification message before proceeding to the next step; or, if the MME determines that the downlink data corresponds to a specific service, the MME will wait for the notification message or request or query the first information from the PCRF.

[0495] For example, steps S58-S59 and S61 may arrive at the MME sequentially:

[0496] If steps S58-S59 reach the MME first, the MME can directly initiate the paging process.

[0497] When the message reaches the MME after steps S58-S59, the MME needs to wait for a notification message before proceeding to the next step. Alternatively, if the MME determines that the downlink data corresponds to a specific service, it may wait for the notification message in step S10 or request or query the first information from the PCRF. Then, it initiates the paging process.

[0498] S63-S64. MME initiates paging process.

[0499] Specifically, the MME sends a paging message to the base station in the registered area, and then the base station sends a paging message to the UE. The paging message carries the first information.

[0500] The paging process in S63 and S64 can be a paging process in the existing mechanism, or a paging process that is re-initiated after an existing paging process fails.

[0501] As can be seen from the foregoing examples, in this embodiment of the application, during the registration process, the MME triggers the subscription of first information to the AF, so that the MME can obtain the first information in a timely manner, so as to achieve the purpose of the core network sending the first information to the UE.

[0502] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0503] To facilitate better implementation of the above-described solutions in the embodiments of this application, related apparatus for implementing the above-described solutions is also provided below.

[0504] Please refer to Figure 12. A communication device 1200 provided in this application embodiment may include: a transmitting module 1201, a receiving module 1202, and a processing module 1203.

[0505] Optionally, the communication device can be an application function device and a management function device as shown in Figures 6-8. The function of the processing module 1303 can be found in the method flow of the application function device and the management function device as shown in Figures 6-8. The processing module can control the sending module to perform corresponding sending operations, control the receiving module to perform corresponding receiving operations, and determine whether the conditions for triggering a sending operation and a receiving operation are met.

[0506] Specifically, this application also provides a communication device, which is an application function device, and the communication device includes:

[0507] A receiving module is configured to receive a first message from a management function device, wherein the first message is used to indicate the reachability status of a first terminal device;

[0508] The sending module is configured to send first information to the management function device when the first message indicates that the first terminal device is unreachable, wherein the first information is used by the first terminal device to determine whether to access the network.

[0509] In other embodiments of this application, a communication device is also provided, specifically a management function device, comprising:

[0510] The sending module is used to send a first message to the application function device, wherein the first message is used to indicate the reachability status of the first terminal device;

[0511] The receiving module is used to receive first information sent by the application function device, wherein the first information is used by the first terminal device to determine whether to access the network.

[0512] In other embodiments of this application, a communication device is also provided, specifically a management function device, comprising:

[0513] The receiving module is configured to receive a downlink data notification message from a user function device, wherein the downlink data notification message indicates that downlink data has arrived, and the downlink data is data sent to the first terminal device;

[0514] The sending module is used to send fourth information to the application function device according to the downlink data notification message. The fourth information is used to obtain first information corresponding to the downlink data. The first information is used by the first terminal device to determine whether to access the network.

[0515] The receiving module is also configured to receive the first information from the application function device.

[0516] In other embodiments of this application, a communication device is also provided, specifically an application function device, comprising:

[0517] The receiving module is used to receive fourth information from the management function device. The fourth information is used to obtain first information corresponding to downlink data. The downlink data is data sent to the first terminal device. The first information is used by the first terminal device to determine whether to access the network.

[0518] The sending module is used to send the first information to the management function device according to the fourth information.

[0519] In other embodiments of this application, a communication device is also provided, specifically a management function device, comprising:

[0520] The sending module is used to send a second subscription message to the application function device in response to the network access request of the first terminal device. The second subscription message is used to subscribe to the first information of the first terminal device, and the first information is used by the first terminal device to determine whether to access the network.

[0521] A receiving module is used to receive the first information sent by the application function device.

[0522] In other embodiments of this application, a communication device is also provided, specifically an application function device, comprising:

[0523] The receiving module is configured to receive a second subscription message from the management function device, the second subscription message being used to subscribe to first information of the first terminal device, the first information being used by the first terminal device to determine whether to access the network;

[0524] The sending module is used to send the first information to the management function device according to the second subscription message.

[0525] It should be noted that the information interaction and execution process between the modules / units of the above-mentioned device are based on the same concept as the method embodiments of this application, and the resulting technical effects are the same as those of the method embodiments of this application. The details can be found in the descriptions of the method embodiments shown above in this application, and will not be repeated here.

[0526] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments of this application, and the various methods / designs / implementations within each embodiment, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments and between the various methods / designs / implementations within each embodiment are consistent and can be mutually referenced. The technical features in different embodiments and the various methods / designs / implementations within each embodiment can be combined to form new embodiments, methods, or implementations according to their inherent logical relationships. The following descriptions of the embodiments of this application do not constitute a limitation on the scope of protection of this application. This application also provides a computer storage medium, wherein the computer storage medium stores a program that performs some or all of the steps described in the above method embodiments.

[0527] Next, another communication device provided in the embodiments of this application will be introduced. Please refer to FIG13. The communication device 1300 includes:

[0528] The communication device 1300 includes a receiver 1301, a transmitter 1302, a processor 1303, and a memory 1304 (the number of processors 1303 in the communication device 1300 can be one or more; Figure 13 shows an example of one processor). In some embodiments of this application, the receiver 1301, transmitter 1302, processor 1303, and memory 1304 can be connected via a bus or other means; Figure 13 shows an example of connection via a bus.

[0529] Memory 1304 may include read-only memory and random access memory, and provides instructions and data to processor 1303. A portion of memory 1304 may also include non-volatile random access memory (NVRAM). Memory 1304 stores operating system and operation instructions, executable modules or data structures, or subsets thereof, or extended sets thereof, wherein the operation instructions may include various operation instructions for implementing various operations. The operating system may include various system programs for implementing various basic business functions and handling hardware-based tasks.

[0530] Processor 1303 controls the operation of the communication device. Processor 1303 can also be called a central processing unit (CPU). Optionally, in practical applications, the various components of the communication device are coupled together through a bus system. This bus system may include not only a data bus but also a power bus, control bus, and status signal bus. However, for clarity, all buses are referred to as a bus system in the diagram.

[0531] The methods disclosed in the embodiments of this application can be applied to or implemented by the processor 1303. The processor 1303 can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware in the processor 1303 or by instructions in the form of software. The processor 1303 can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 1304. Processor 1303 reads the information in memory 1304 and, in conjunction with its hardware, completes the steps of the above method.

[0532] The receiver 1301 can be used to receive input digital or character information and generate signal inputs related to the settings and function control of the communication device. The transmitter 1302 may include a display device such as a display screen and can be used to output digital or character information through an external interface.

[0533] In this embodiment of the application, the processor 1303 is used to execute the method flow for executing the application function device and the management function device in Figures 6-8.

[0534] In another possible design, when the communication device is a chip within an application function device and a management function device, the chip includes a processing unit and a communication unit. The processing unit may be, for example, a processor, and the communication unit may be, for example, an input / output interface, pins, or circuits. The processing unit can execute computer execution instructions stored in a storage unit to cause the chip within the terminal to perform any of the methods described in the first aspect above. Optionally, the storage unit may be a storage unit within the chip, such as a register or cache. Alternatively, the storage unit may be a storage unit located outside the chip within the terminal, such as read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions, such as random access memory (RAM).

[0535] The processor mentioned above can be a general-purpose central processing unit, a microprocessor, an ASIC, or one or more integrated circuits used to control the execution of programs for the above communication methods.

[0536] It should also be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. In addition, in the device embodiment drawings provided in this application, the connection relationship between modules indicates that they have a communication connection, which can optionally be implemented as one or more communication buses or signal lines.

[0537] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware, or it can be implemented by special-purpose hardware including application-specific integrated circuits, special-purpose CPUs, special-purpose memory, special-purpose components, etc. Generally, any function performed by a computer program can be easily implemented by corresponding hardware, and the hardware structure used to implement the same function can also be diverse, such as analog circuits, digital circuits, or special-purpose circuits. However, for this application, software program implementation is more often the preferred implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a computer floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk, or optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0538] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product.

[0539] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

Claims

A communication method, characterized in that, The method is applied to an application function device, and the method includes: Receive a first message from the management function device, the first message being used to indicate the reachability status of the first terminal device; If the first message indicates that the first terminal device is unreachable, a first message is sent to the management function device, wherein the first message is used by the first terminal device to determine whether to access the network. The method according to claim 1, characterized in that, The method further includes: Send a first subscription message to the management function device. The first subscription message is used to subscribe to the reachability status of the first terminal device. The method according to claim 2, characterized in that, Sending the first subscription message to the management function device includes: The first subscription message is sent to the management function device according to the second information; the second information includes at least one of the following: target service type, target service identifier, target sender, or target access network type. The method according to claim 3, characterized in that, Sending the first subscription message to the management function device based on the second information includes: The first subscription message is sent to the management function device according to the configuration information of the application function device. The configuration information of the application function device is used to indicate at least one of the following: the service served by the application function device is a target service type, the service served by the application function device is a target service identifier, the terminal device served by the application function device is a target sender, or the service served by the application function device accesses the network through a target access network type. The method according to any one of claims 2 to 4, characterized in that, The first subscription message includes at least one of the following: target service type, target service identifier, target sender, or target access network type. The method according to claim 4 or 5, characterized in that, Sending the first subscription message to the management function device according to the configuration information of the application function device includes: Before the application function device receives or sends the target service, the first subscription message is sent to the management function device according to the configuration information of the application function device. The method according to any one of claims 1 to 6, characterized in that, The first message is used to indicate the reachability state of the first terminal device, including: the first message is used to indicate that the first terminal device is in an idle state, or to indicate that the first terminal device enters an idle state. The method according to any one of claims 1 to 7, characterized in that, The first message includes a first field, which is used to indicate the reachability status of the first terminal device. The method according to any one of claims 1 to 8, characterized in that, Sending the first information to the management function device includes: Send a service information notification message to the management function device, the service information notification message including the first information. The method according to any one of claims 1 to 9, characterized in that, The first information includes at least one of the following: service type, service identifier, or sender. The method according to any one of claims 1 to 10, characterized in that, The first information is included in the paging message sent by the management function device to the first terminal device. A communication method, characterized in that, The method is applied to a management function device, and the method includes: Send a first message to the application function device, the first message being used to indicate the reachability status of the first terminal device; The first terminal device receives first information sent by the application function device, wherein the first information is used to determine whether to access the network. The method according to claim 12, characterized in that, The method further includes: Receive a first subscription message sent by the application function device, wherein the first subscription message is used to subscribe to the reachability status of the first terminal device. The method according to claim 12 or 13 is characterized in that, Sending the first message to the application function device includes: Whether to allow the first terminal device to use the target service is determined based on third information, wherein the third information includes at least one of the following: the subscription information of the first terminal device, the policy information of the policy control device, or the configuration information of the management function device; If the first terminal device is allowed to use the target service, the first message is sent to the application function device. The method according to claim 13, characterized in that, The first subscription message includes at least one of the following: target service type, target service identifier, target sender information, or target access network type; Sending the first message to the application function device includes: Receive a downlink data notification message from a user function device, the downlink data notification message being used to indicate that downlink data has arrived, the downlink data being the data sent to the first terminal device; Determine whether the service corresponding to the downlink data matches the first subscription message; If the service corresponding to the downlink data matches the first subscription message, the first message is sent to the application function device. The method according to claim 12 or 13 is characterized in that, Sending the first message to the application function device includes: Receive a downlink data notification message from a user function device, the downlink data notification message being used to indicate that downlink data has arrived, the downlink data being the data sent to the first terminal device; Based on the downlink data notification message, determine whether the service corresponding to the downlink data is a target service, or whether it is a target service type, or whether it comes from a target sender, or whether the downlink data is accessed through a target access network type; If the service corresponding to the downlink data is the target service, or is the target service type, or comes from the target sender, or the downlink data accesses the network through the target access network type, the first message is sent to the application function device. The method according to any one of claims 12 to 16, characterized in that, The first information is included in the paging message sent by the management function device to the first terminal device. A communication device includes at least one processor and at least one memory coupled to the processor, the processor being configured to perform the method of any one of claims 1 to 11, or claims 12 to 17. A computer-readable storage medium includes instructions that, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 11, or claims 12 to 17. A computer program product comprising instructions that, when run on a computer, cause the computer to perform the method as described in claims 1 to 11, or any one of claims 12 to 17. A chip or chip system, characterized in that, The device includes one or more interface circuits and one or more processors; the interface circuits are configured to receive signals from the memory of the electronic device and send the signals to the processors, the signals including computer instructions stored in the memory; when the processor executes the computer instructions, the electronic device performs the communication method of any one of claims 1 to 11, or claims 12 to 17.

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