Communication method and device

Abstract

The invention discloses a communication method and device. A first network element receives a first request from a calling terminal, wherein the first request is used for requesting a first service. And the first network element sends a first request to the called terminal. And after determining that the first service fails, the first network element sends a first message to a second network element in the core network to trigger the second network element to send an elastic notification to the called terminal, and the elastic notification is used for indicating the information of the first service and / or the information of the calling terminal. A user using the called terminal (e.g., called user) can determine whether to perform a satellite-facing operation to receive the first traffic according to the resilient notification. Therefore, the power consumption of the called terminal can be reduced.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0002] In satellite communication scenarios, if a called terminal receives a service request, the network can page that terminal, prompting it to remind the user to perform a satellite alignment operation (adjusting the phone's antenna to align with the satellite for a better signal) to receive the service. How to flexibly and effectively notify the called terminal is a problem that needs to be solved. Summary of the Invention

[0003] This application provides a communication method and apparatus for flexibly and effectively notifying the called terminal.

[0004] Firstly, a first communication method is provided, which can be applied to a first device or a first network element. The first device or first network element is, for example, a network-side device, also referred to as a network device. The network device is, for example, a network equipment, or other equipment including network equipment functions, or a circuit, or a chip system (or chip) or other functional module capable of implementing the functions of the network equipment, and is, for example, disposed within the network equipment. The network equipment is, for example, a third-party server, or an IMS device, or a short message service network element, etc. For example, the third-party server is, for example, an AF; the IMS device is, for example, an IMS AS, or a P-CSCF, or an S-CSCF, etc.; the short message service network element is, for example, an SMSF, or an MSC / VLR, or an IP-SM-GW, etc. The method includes: receiving a first request from a calling terminal, the first request being used to request a first service; sending the first request to the called terminal; and after determining that the first service has failed, sending a first message to a second network element in the core network, the first message being used to trigger the second network element to send a resilient notification to the called terminal, the resilient notification being used to indicate information about the first service and / or to indicate information about the calling terminal.

[0005] In this embodiment, the second network element can send a flexible notification to the called terminal, and this flexible notification can indicate information about the first service and / or information about the calling terminal, making the notification method more flexible. The user using the called terminal (e.g., the called user) can determine whether to perform satellite pairing operations to receive the first service based on the information indicated by the flexible notification. For example, the called user can determine whether to receive the first service based on factors such as its importance and / or the identity of the calling terminal. Therefore, this flexible notification provides more information for the called user's judgment, making the notification method more effective. Furthermore, for users, performing satellite pairing operations when using satellite access is cumbersome, especially in remote mountainous areas where unobstructed areas must be found. If the terminal responds to all network paging requests, it may also interfere with the user, resulting in a poor user experience. However, in this embodiment, because the flexible notification indicates more information to the called user, if the called user believes that receiving the first service is unnecessary, then satellite pairing operations are not required, thus reducing interference to the called user. Furthermore, in this embodiment, the first network element can trigger the second network element to send an elastic notification only if the first service fails. This not only serves to remind the called user but also reduces interference to the called user.

[0006] In an optional implementation, before sending the first message to the second network element in the core network, the method further includes: determining that the called terminal accesses the core network via satellite. Due to the long distance between satellites and the ground, satellite communication has relatively lower reliability compared to terrestrial network communication scenarios. In scenarios where the called terminal accesses the core network via satellite, if the called terminal is paged via a paging message, the called terminal may not receive the paging message due to its limited coverage. Therefore, in scenarios where the called terminal accesses the core network via satellite, embodiments of this application can send a flexible notification to the called terminal. Compared to paging messages, flexible notifications can have stronger coverage, for example, by sending more flexible notifications and / or having higher transmission power, thereby increasing the probability that the called terminal is notified.

[0007] In an optional implementation, before sending the first message to the second network element in the core network, the method further includes: determining that the information of the calling terminal is included in first information, wherein the first information includes information on one or more terminals allowed to send elastic notifications. The first information can be understood, for example, as a whitelist. Optionally, the first information can be set by the called terminal, for example, by the user using the called terminal. The first information set for different called terminals can be the same or different. For example, a user using a called terminal can set the phone numbers of important users in the first information; if these phone numbers are used as calling numbers, the called terminal can receive elastic notifications in the case of satellite access. Phone numbers not included in the first information may be phone numbers that the called terminal (or the user using the called terminal) considers unimportant or even nuisance numbers. If these phone numbers are used as calling numbers, the first network element does not need to trigger the second network element to send elastic notifications, thereby reducing the transmission overhead of elastic notifications and reducing interference to the user using the called terminal.

[0008] In one optional implementation, the flexible notification is used to indicate information about the calling terminal, including: the flexible notification includes a first index, the first index being the index corresponding to the information of the calling terminal in the first information, wherein the first information includes information about one or more terminals and the corresponding index. In this way, the flexible notification does not necessarily need to include the information of the calling terminal, but only needs to include the index corresponding to the information of the calling terminal, thereby reducing the transmission overhead of the flexible notification.

[0009] In one optional implementation, the first network element is an IMS AS, S-CSCF, P-CSCF, or SMS service network element within the core network that serves the called terminal. Determining the first service failure includes: receiving a second message and determining the first service failure based on the second message; or, not receiving a response message corresponding to the first request when a first timer corresponding to the first request times out. For the first network element, the first service failure can be determined based on a second message from another network element, or it can be determined based on a first timer maintained by the first network element, providing greater flexibility.

[0010] In one optional implementation, determining the first service failure based on the second message includes: the second message indicating the first service failure or indicating a request timeout. The second message may indicate the first service failure, or it may indicate a request timeout, or it may indicate other information. The first network element only needs to be able to determine the first service failure based on the second message, and there is no limitation on the content indicated by the second message.

[0011] In one optional implementation, the first message is a message corresponding to a service-oriented interface, and the core network is 5GC; or, the first message is a message corresponding to a non-service-oriented interface, and the core network is EPC.

[0012] Secondly, a second communication method is provided, which can be applied to a first device or a first network element. For a description of the first device or the first network element, please refer to the first aspect. The method includes: receiving a first request from a calling terminal, the first request being for requesting a first service; and sending a first message to a second network element in the core network, the first message being for triggering the second network element to send a flexible notification to the called terminal, the flexible notification being for indicating information about the first service and / or indicating information about the calling terminal.

[0013] In this embodiment, the second network element can send a flexible notification to the called terminal, and this flexible notification can indicate information about the first service and / or information about the calling terminal, making the notification method more flexible. The user using the called terminal (e.g., the called user) can determine whether to perform satellite pairing operations to receive the first service based on the information indicated by the flexible notification. For example, the called user can determine whether to receive the first service based on factors such as the importance of the first service and / or the identity of the calling terminal. Therefore, this flexible notification provides more information for the called user's judgment, making the notification method more effective. Furthermore, for users, performing satellite pairing operations when using satellite access is cumbersome, especially in remote mountainous areas where unobstructed areas must be found. If the terminal prompts the user to respond to every network paging request, it may also interfere with the user's experience. However, in this embodiment, because the flexible notification indicates more information to the called user, if the called user believes that receiving the first service is unnecessary, then satellite pairing operations are not required, thus reducing interference for the called user. Furthermore, in this embodiment, the second network element can be triggered to send an elastic notification after receiving the first request. This implementation method can improve the sending efficiency of the elastic notification, so that the called UE can know that the first service has arrived as soon as possible.

[0014] In one alternative implementation, before sending the first message to the second network element in the core network, the method further includes: determining that the called terminal accesses the core network via satellite.

[0015] In an optional implementation, before sending the first message to a second network element in the core network, the method further includes: determining that the information of the calling terminal is included in first information, wherein the first information includes information of one or more terminals that are allowed to send elastic notifications.

[0016] In one optional implementation, the flexible notification is used to indicate information of the calling terminal, including: the flexible notification includes a first index, the first index being the index of the calling terminal's information in the first information, wherein the first information includes information of the one or more terminals and the corresponding index.

[0017] In one optional implementation, the first message is a message corresponding to a service-oriented interface, and the core network is 5GC; or, the first message is a message corresponding to a non-service-oriented interface, and the core network is EPC.

[0018] For the technical effects of the various alternative implementations of the second aspect, please refer to the description of the technical effects of the corresponding implementations in the first aspect.

[0019] Thirdly, a third communication method is provided, which can be applied to a second device or a second network element. The second device or network element is, for example, a network-side device, also referred to as a network device. For an introduction to network devices, please refer to the first aspect. Optionally, the second device or network element is, for example, an AMF or MME. The method includes: receiving a first message, the first message being used to trigger the second network element to send a flexible notification to the called terminal, the flexible notification being used to indicate information about a first service and / or information about the calling terminal corresponding to the first service; and sending the flexible notification, wherein the flexible notification is used to indicate information about the first service and / or information about the calling terminal.

[0020] In one optional implementation, sending the flexible notification includes: sending the flexible notification to an access network device, the flexible notification instructing the access network device to send information indicating the first service and / or information of the calling terminal to the called terminal in a manner different from paging; wherein, the manner different from paging includes: the transmission power of the information indicating the first service and / or information of the calling terminal is greater than the transmission power of a paging message, and / or, the number of times the information indicating the first service and / or information of the calling terminal is transmitted is greater than the number of times a paging message is transmitted. Optionally, this manner different from paging can be, for example, a flexible notification method, or other methods. This manner different from paging can have stronger coverage than paging, thereby increasing the probability that the called terminal receives the information.

[0021] In one optional implementation, the first message is a message corresponding to a service-oriented interface, and the core network is 5GC; or, the first message is a message corresponding to a non-service-oriented interface, and the core network is EPC.

[0022] In an optional implementation, before sending the flexible notification, the method further includes: sending a paging message to page the called terminal; and if no response is received from the called terminal. The paging message can be sent first, and if the called terminal responds, the flexible notification need not be sent. The number of paging messages sent can be less than the number of flexible notifications sent, thereby reducing signaling overhead. If the called terminal does not respond to the paging message, a flexible notification can be sent to increase the probability that the called terminal is paged.

[0023] In an optional implementation, the method further includes: receiving first information, the first information including information about one or more terminals that are allowed to make flexible notifications; and sending the first information to a fourth network element.

[0024] In one optional implementation, the flexible notification is used to indicate information of the calling terminal, including: the flexible notification includes a first index, the first index being the index of the calling terminal's information in the first information, wherein the first information includes information of the one or more terminals and the corresponding index.

[0025] Regarding the technical effects of the third aspect or optional implementations of the third aspect, refer to the description of the technical effects of the first aspect or corresponding implementations, and / or refer to the description of the technical effects of the second aspect or corresponding implementations.

[0026] Fourthly, a communication device is provided. The communication device can be a network-side device as described in the first, second, or third aspect above. The communication device possesses the functions of the aforementioned network-side device. For example, the communication device is capable of implementing the functions described in the first, second, or third aspect above. For instance, the communication device includes modules, units, or means corresponding to performing the operations involved in the first, second, or third aspect above. These modules, units, or means can be implemented through software, hardware, or a combination of software and hardware. The communication device is, for example, a network device, or other device including network device functions, or a chip system (or chip or circuit) or other functional module capable of implementing the functions of a network device, and such chip system or functional module is, for example, disposed within a network device. The network device is, for example, a third-party server, an IMS device, a short message service network element, or a core network device, etc. For example, the third-party server may be an AF; the IMS device may be an IMS AS, P-CSCF, or S-CSCF; the SMS service network element may be an SMSF, MSC / VLR, or IP-SM-GW; and the core network device may be an AMF or MME. In one optional implementation, the communication device includes a baseband device and a radio frequency device. In another optional implementation, the communication device includes a processing unit (sometimes also called a processing module) and a transceiver unit (sometimes also called a transceiver module). The transceiver unit can implement both sending and receiving functions. When the transceiver unit implements the sending function, it can be called a sending unit (sometimes also called a sending module), and when it implements the receiving function, it can be called a receiving unit (sometimes also called a receiving module). The sending unit and the receiving unit can be the same functional module, which is called the transceiver unit and can implement both sending and receiving functions; or, the sending unit and the receiving unit can be different functional modules, and the transceiver unit is a collective term for these functional modules.

[0027] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a first request from the calling terminal, the first request being for requesting a first service; the transceiver unit (or the sending unit) is configured to send the first request to the called terminal; the transceiver unit (or the sending unit) is further configured to, after determining that the first service has failed, send a first message to a second network element in the core network, the first message being for triggering the second network element to send a flexible notification to the called terminal, the flexible notification being for indicating information about the first service and / or indicating information about the calling terminal.

[0028] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a first request from the calling terminal, the first request being for requesting a first service; the transceiver unit (or the sending unit) is configured to send a first message to a second network element in the core network, the first message being for triggering the second network element to send a flexible notification to the called terminal, the flexible notification being for indicating information about the first service and / or indicating information about the calling terminal.

[0029] In one optional implementation, the transceiver unit (or the receiving unit) is configured to receive a first message, the first message being configured to trigger the second network element to send an elastic notification to the called terminal, the elastic notification being configured to indicate information of a first service and / or information of the calling terminal corresponding to the first service; the transceiver unit (or the sending unit) is configured to send the elastic notification, wherein the elastic notification is configured to indicate information of the first service and / or information of the calling terminal.

[0030] In an alternative embodiment, the communication device further includes a storage unit (sometimes also called a storage module), and the processing unit is configured to couple with the storage unit and execute programs or instructions in the storage unit to enable the communication device to perform the functions of the network-side device described in the first, second, or third aspect above.

[0031] Fifthly, a communication device is provided, the communication device comprising a memory and one or more processors. The memory is used to store part or all of a computer program or instructions necessary for implementing the functions involved in the first, second, or third aspects described above. The one or more processors are capable of executing the computer program or instructions, such that when the computer program or instructions are executed, the communication device implements the methods in any possible design or implementation of the first, second, or third aspects described above.

[0032] In one possible design, the communication device may further include an interface circuit, wherein the processor is used to communicate with other devices or components through the interface circuit.

[0033] In one possible design, the communication device may also include the memory.

[0034] The aforementioned communication device may be a network device, a communication module in a network device, or a chip in a network device that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip that contains a modem module.

[0035] A sixth aspect provides a communication system including a first network element, wherein the first network element is used to perform the method performed by the first network element as described in the first or second aspect. For example, the first network element can be implemented using the communication device described in the fourth or fifth aspect.

[0036] Optionally, the communication system further includes a second network element, wherein the second network element is used to perform the method described in the third aspect above. For example, the second network element can be implemented using the communication device described in the fourth or fifth aspect.

[0037] In a seventh aspect, a computer-readable storage medium is provided for storing a computer program or instructions that, when executed, cause the methods performed by the network-side devices in the above aspects to be implemented.

[0038] Eighthly, a computer program product containing instructions is provided, which, when the computer program or instructions are run on a computer, causes the methods described in the above aspects to be implemented.

[0039] Ninthly, a chip system is provided, including a processor and an interface, the processor being configured to call and execute instructions from the interface to enable the chip system to implement the methods of the above aspects. Attached Figure Description

[0040] Figure 1 , Figure 2 , Figures 3A-3C These are schematic diagrams illustrating several application scenarios of embodiments of this application;

[0041] Figures 4 to 13 Flowcharts of several communication methods provided in the embodiments of this application;

[0042] Figure 14 A schematic diagram of an apparatus provided in an embodiment of this application;

[0043] Figure 15 This is a schematic diagram of another device provided in an embodiment of this application. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0045] In this application embodiment, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c means: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0046] The ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects and are not used to limit the size, content, order, timing, priority, or importance of the multiple objects. Furthermore, the numbering of steps in the various embodiments described in this application is only to distinguish different steps and is not used to limit the order in which the steps are performed.

[0047] The following explanations of some terms or concepts used in the embodiments of this application are provided to facilitate understanding by those skilled in the art.

[0048] In this embodiment of the application, the terminal device is a device with wireless transceiver function, which may be a fixed device, a mobile device, a handheld device (e.g., a mobile phone), a wearable device, an in-vehicle device, or a wireless device (e.g., a communication module, a modem, or a chip system, etc.) built into the above devices. The terminal devices are used to connect people, things, and machines, and can be widely used in various scenarios, including but not limited to the following: satellite communication scenarios, sensing scenarios, cellular communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine / machine-type communications (M2M / MTC) communication, Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical care, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, drones, robots, and terminal devices for indoor commercial scenarios (such as mobile phone screen mirroring, file sharing, and mobile phone to VR glasses). When the terminal equipment is applied to V2X, it can also be called a V2X device, such as a smart car, digital car, unmanned car, driverless car, pilotless car, or automobile, self-driving car, or autonomous car, pure electric vehicle (EV), hybrid electric vehicle (HEV), range-extended electric vehicle (REEV), plug-in hybrid electric vehicle (PHEV), new energy vehicle, or roadside unit (RSU). The terminal equipment can also be a device used in D2D communication, such as an electricity meter or water meter.

[0049] Furthermore, in this embodiment, the terminal device can also be a terminal device in an Internet of Things (IoT) system. IoT is an important component of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection.

[0050] The various terminal devices described above, if located in a vehicle (e.g., placed inside or installed inside a vehicle), can all be considered in-vehicle terminal devices, also known as on-board units (OBUs). The terminal device of this application can also be an in-vehicle module, in-vehicle component, in-vehicle chip, or in-vehicle unit built into a vehicle as one or more components or units. The vehicle can implement the methods of this application through the built-in in-vehicle module, in-vehicle component, in-vehicle chip, or in-vehicle unit.

[0051] The terminal equipment may sometimes be referred to as user equipment (UE), terminal, access station, UE station, remote station, wireless communication equipment, or user device, etc.

[0052] In this application embodiment, the device for implementing the terminal device function can be a terminal device, which can be a terminal device or a device capable of supporting the terminal device in implementing the function, such as a chip system. This device can be installed in the terminal device. In the technical solutions provided in this application embodiment, the example of a terminal device being used to implement the terminal device function is used to describe the technical solutions provided in this application embodiment.

[0053] The network devices in this application embodiment include, for example, access network devices (or access network elements) and / or core network devices (or core network elements). The access network devices are devices with wireless transceiver capabilities, used to communicate with the terminal devices. The access network devices include, but are not limited to, base stations (base transceiver stations (BTS), Node B, evolved Node B (eNodeB) / eNB, or the next generation Node B (gNodeB) / gNB), transmission reception points (TRPs), base stations evolved from the 3rd generation partnership project (3GPP), access nodes in wireless fidelity (Wi-Fi) systems, wireless relay nodes, wireless backhaul nodes, etc. The base stations can be: macro base stations, micro base stations, pico base stations, small cells, relay stations, etc. Multiple base stations can support networks using the same access technology or networks using different access technologies. A base station can contain one or more co-located or non-co-located transmission and reception points. The access network equipment can also be a radio controller, centralized unit (CU), and / or distributed unit (DU) in a cloud radioaccess network (CRAN) scenario. The access network equipment can also be a server, etc. For example, the network equipment in V2X technology can be a roadside unit (RSU). The following description uses a base station as an example to illustrate the access network equipment. A base station can communicate with a terminal device, or it can communicate with a terminal device through a relay station. A terminal device can communicate with multiple base stations in different access technologies. The core network equipment is used to implement functions such as mobility management, data processing, session management, policy and billing. The names of the equipment implementing core network functions may differ in systems using different access technologies; this application does not limit this.Taking the 5th generation (5G) mobile communication technology system as an example, the core network equipment includes, for example, access and mobility management function (AMF), session management function (SMF), policy control function (PCF), or user plane function (UPF), etc.

[0054] In a CU-DU architecture, or in an open RAN (ORAN) system, access network equipment may include one or more logical network elements such as a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). CUs and DUs may be separate entities or included in the same network element, such as a baseband unit (BBU). RUs may be included in radio equipment or radio units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0055] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called an open CU (O-CU), DU can also be called an open DU (O-DU), CU-CP can also be called an open CU-CP (O-CU-CP), CU-UP can also be called an open CU-UP (O-CU-CP), and RU can also be called an open RU (O-RU). For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples in its embodiments. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in the embodiments of this application can be implemented through software modules, hardware modules, or a combination of software modules and hardware modules.

[0056] The CU and DU can be configured according to the protocol layer functions of the wireless network they implement. For example, the CU can be configured to implement the functions of the Packet Data Convergence Protocol (PDCP) layer and above (such as the Radio Resource Control (RRC) layer and / or the Service Data Adaptation Protocol (SDAP) layer); the DU can be configured to implement the functions of protocol layers below the PDCP layer (such as one or more of the Radio Link Control (RLC) layer, Media Access Control (MAC) layer, or Physical (PHY) layer). Alternatively, the CU can be configured to implement the functions of protocol layers above the PDCP layer (such as the RRC and / or SDAP layers), and the DU can be configured to implement the functions of protocol layers below the PDCP layer (such as one or more of the RLC, MAC, or PHY layers).

[0057] The above CU and DU configurations are merely examples; the functions of the CU and DU can be configured as needed. For instance, the CU or DU can be configured to have more protocol layer functions, or only some protocol layer processing functions. For example, some RLC layer functions and protocol layer functions above the RLC layer can be placed in the CU, while the remaining RLC layer functions and protocol layer functions below the RLC layer can be placed in the DU. Furthermore, the functions of the CU or DU can be divided according to service type or other system requirements, such as by latency. Functions that require low latency can be placed in the DU, while functions that do not require low latency can be placed in the CU.

[0058] DU and RU can cooperate to implement the functions of the PHY layer. A DU can be connected to one or more RUs. The functions of DU and RU can be configured in various ways depending on the design. For example, a DU can be configured to implement baseband functions, and an RU can be configured to implement mid-RF functions. Another example is that a DU can be configured to implement higher-level functions in the PHY layer, and an RU can be configured to implement lower-level functions in the PHY layer, or to implement both lower-level and RF functions. Higher-level functions in the physical layer can include a portion of the physical layer's functions that are closer to the MAC layer, while lower-level functions in the physical layer can include another portion of the physical layer's functions that are closer to the mid-RF side.

[0059] In this application embodiment, the apparatus for implementing the functions of a network device can be referred to as a network apparatus. This network apparatus can be a network element, a network device, or an apparatus capable of supporting the network device or network element in implementing the function, such as a chip system. This apparatus can be installed within the network device. In the technical solutions provided in this application embodiment, the apparatus for implementing the functions of a network device is described as a network apparatus (for example, an apparatus for implementing the functions of an access network apparatus is an access network apparatus, and an apparatus for implementing the functions of a core network apparatus is a core network apparatus).

[0060] In general, in this embodiment, the second network element can send a flexible notification to the called terminal, and this flexible notification can indicate information about the first service and / or information about the calling terminal, making the notification method more flexible. The user using the called terminal (e.g., the called user) can determine whether to perform satellite pairing operations to receive the first service based on the information indicated by the flexible notification. For example, the called user can determine whether to receive the first service based on factors such as the importance of the first service and / or the identity of the calling terminal. Therefore, this flexible notification can provide more information for the called user's judgment, making the notification method more effective. Furthermore, for users, performing satellite pairing operations when using satellite access is cumbersome, especially in remote mountainous areas where unobstructed areas must be found. If the terminal prompts the user to respond to every network paging request, it may also cause interference and result in a poor user experience. However, in this embodiment, because more information is provided to the called user, if the called user believes that receiving the first service is unnecessary, then satellite pairing operations are not required, thus reducing interference to the called user. Furthermore, in this embodiment, the first network element can trigger the second network element to send an elastic notification only if the first service fails. This not only serves to remind the called user but also reduces interference to the called user.

[0061] The communication method provided in this application can be applied to fourth-generation (4G) communication systems, such as long-term evolution (LTE) communication systems, as well as fifth-generation (5G) communication systems, such as 5G new radio (NR) communication systems, or to various communication systems evolving after 5G, such as future communication systems. The method provided in this application can be applied to terrestrial networks (TN); alternatively, the method provided in this application can also be applied to non-terrestrial networks (NTN), such as satellite communication systems, for example, transparent satellite architectures, backhaul satellite architectures, or regenerative satellite architectures, etc., without limitation.

[0062] Please refer to Figure 1 This is a schematic diagram illustrating an application scenario according to an embodiment of this application. Figure 1 The present application is used as an example of a 4G system. Figure 1In this context, the Internet Protocol Multimedia Subsystem (IMS) can be overlaid on the 4G network, or it can be understood as network elements within the IMS communicating with network elements within the 4G network. The IMS may include network elements such as the IMS application server (IMS AS), interrogating-call session control function (I-CSCF) / serving-call session control function (S-CSCF), proxy-call session control function (P-CSCF), and IMS access gateway (AGW). The 4G network may include the 4G core network and the 4G access network. The 4G access network may include the radio access network (RAN). The 4G core network is, for example, an evolved packet core (EPC). The EPC may include a home subscriber server (HSS), a policy and charging rules function (PCRF), a packet data network gateway control plane function (PGW-C), a packet data network gateway user plane function (PGW-U), a mobility management entity (MME), and a serving gateway (SGW). The EPC can communicate with the data network (DN) via the PGW-U.

[0063] In addition, network elements related to SMS services can also communicate with network elements within the IMS and the EPC. These network elements may include a Short Message Service Center (SMSC), a Gateway Message Service Center for Short Message Service (SMS-GMSC), and an Internet Protocol Short Message Gateway (IP-SM-GW). Specifically, the SMS-GMSC can communicate with the HSS within the EPC; the IP-SM-GW can communicate with the HSS within the EPC, and also with the I-CSCF / S-CSCF within the IMS.

[0064] exist Figure 1 Among the network elements within the EPC shown, the HSS can be responsible for storing IMS user subscription data.

[0065] PCRF can be responsible for the control and management of policies and billing rules.

[0066] MME can be responsible for user mobility management.

[0067] PGW-C can be responsible for providing control plane functions for packet data network gateways (PGWs).

[0068] PGW-U can be responsible for providing the user plane functionality of PGW.

[0069] SGW can handle user plane processing, including functions such as packet routing and forwarding. SGW can support the handover of different access technologies under the 3rd Generation Partnership Project (3GPP), and can act as an anchor point for the user plane when access technologies are switched.

[0070] exist Figure 1 Among the network elements within the IMS shown, the IMS AS can provide users with basic IMS services and supplementary services.

[0071] The I-CSCF is the unified entry point for the home network of IMS users. It is responsible for allocating S-CSCFs that serve users or for querying S-CSCFs that serve users.

[0072] S-CSCF can be responsible for IMS user registration, authentication, sessions, routing, and triggering services.

[0073] The P-CSCF is the entry network element for users to access IMS. It is responsible for forwarding Session Initialization Protocol (SIP) signaling between IMS users and their home network (HN).

[0074] IMS-AGW can provide functions such as IMS access gateway and media gateway.

[0075] exist Figure 1 Among the SMS service network elements shown, the SMSC is the SMS center, which is responsible for transmitting, storing, and forwarding SMS messages between the UE and other SMS service network elements.

[0076] SMS-GMSC is a function of the message service center (MSC) that is responsible for receiving SMS messages within the public land mobile network (PLMN) and submitting the received SMS messages to the SMS recipient's SMS center (such as the SMS recipient's SMSC).

[0077] IP-SM-GW can be responsible for protocol conversion between UEs that support Internet Protocol (IP) short messages and SMS centers (such as SMSCs).

[0078] Please refer to this again. Figure 2 This is a schematic diagram illustrating another application scenario of this application embodiment. Figure 2 The present application is used as an example of a 5G system.

[0079] Figure 2In this context, IMS can be overlaid on the 5G network, or it can be understood that network elements within the IMS can communicate with network elements within the 5G network. The IMS may include network elements such as IMS AS, I-CSCF / S-CSCF, P-CSCF, and IMS-AGW. The 5G network may include the 5G core network and the 5G access network. The 5G access network may include the RAN. The 5G core network, for example, is the 5G core network (5GC), which may include network exposure function (NEF), unified data management (UDM), authentication server function (AUSF), AMF, policy control function (PCF), and session management function (SMF). The 5GC can communicate with the DN through the UPF.

[0080] In addition, network elements related to SMS services can also communicate with network elements within the IMS and the EPC. Network elements related to SMS services may include SMSC, SMS-GMSC, IP-SM-GW, and Short Message Service Function (SMSF), etc. For information on the communication relationships between various network elements, please refer to [reference needed]. Figure 2 The connection relationships between network elements.

[0081] Figure 2 It also illustrates third-party network elements, such as application functions (AFs), which are third-party applications responsible for invoking the operator's network capabilities. This AF can communicate with network elements within the 5GC via the NEF within the 5GC.

[0082] exist Figure 2 Among the network elements within the 5GC shown, NEF can be responsible for exposing network capabilities to third parties.

[0083] UDM can be responsible for storing IMS user subscription data.

[0084] AUSF can be responsible for authenticating users.

[0085] AMF can be responsible for user access and mobility management, among other things.

[0086] PCF can be responsible for the control and management of policies and billing rules.

[0087] SMF can be responsible for user session management.

[0088] exist Figure 2 In the SMS service network element shown, the SMSF can be responsible for forwarding non-access stratum (NAS) SMS messages received by the AMF to the SMS center (e.g., SMSC), or it can be responsible for sending SMS messages from the SMS center to the AMF, which can then be sent to the UE by the AMF through the NAS interface.

[0089] about Figure 2 The descriptions of other SMS service network elements besides SMSF, as well as network elements within IMS, can be found in the documentation for [link to documentation]. Figure 1 Introduction to the relevant network elements.

[0090] in, Figure 1 and Figure 2 The diagram shows the called network; the calling network is not shown. The calling and called networks can have the same or different structures, and they can communicate with each other.

[0091] As mentioned above, the embodiments of this application can be applied to NTN, so please refer to [the relevant documentation]. Figures 3A-3C This diagram illustrates several network architectures of NTN, and also represents several application scenarios in embodiments of this application. Among them, the architecture where the UE connects to the terrestrial access network via satellite can be called a transparent satellite architecture (e.g., Figure 3A The architecture that places access network equipment on a satellite (or the satellite has the function of access network equipment) is called a regenerative satellite architecture or regenerative star architecture (e.g. Figure 3B The architecture where the UE connects to the terrestrial access network and then connects to the terrestrial network via satellite can be called a satellite backhaul architecture (e.g., UE connects to the terrestrial access network and then connects to the terrestrial network via satellite). Figure 3C ).

[0092] exist Figure 3A In this system, the network elements used for transmitting services (such as access network equipment and / or core network equipment) are all located on the ground. The UE accesses the network through the access network equipment located on the ground via satellite, and the satellite has a pass-through function.

[0093] exist Figure 3B In this configuration, access network equipment is mounted on a satellite, or the underlying processing modules of access network elements are mounted on a satellite, or the satellite possesses some or all of the functions of the access network equipment. Besides the access network equipment, other network elements used for service transmission (such as core network equipment) are located on the ground. Alternatively, some or all of the network elements in the core network can also be mounted on a satellite, or the satellite can possess some or all of the functions of the network elements in the core network.

[0094] exist Figure 3C In this system, the access network equipment is located on the ground. The UE communicates with the satellite through the ground access network and then connects to the ground network through the satellite.

[0095] Optional, Figure 3A , Figure 3B or Figure 3C The satellites in the system can also be replaced by aerial equipment such as drones or high-altitude aircraft.

[0096] The method provided in the embodiments of this application is described below with reference to the accompanying drawings. In various embodiments of this application, the flexible notification can be sent via broadcast. The function of the flexible notification is similar to paging, and it can be used to transmit information to a specific UE. For example, the flexible notification can be used to page the UE, or to notify the UE that a called service has arrived, or to indicate that the UE missed a called service, or to indicate the information of the missed called service, or to notify the UE to change its environment, or to notify the UE to align with a satellite, or to notify the UE to move to a line-of-sight (LoS) path with the satellite, or to notify the UE to improve its channel quality, etc. Optionally, coverage enhancement can be set for the flexible notification. For example, the flexible notification can be sent multiple times, and / or sent with higher power (e.g., the transmission power of the flexible notification is higher than that of the paging message, and / or the transmission power of the flexible notification is higher than a certain threshold). By setting coverage enhancement, the success rate of the UE receiving the flexible notification can be improved.

[0097] In the accompanying drawings corresponding to the various embodiments of this application, all steps indicated by dashed lines are optional. The various embodiments herein can be applied to... Figure 1 , Figure 2 , Figures 3A-3C The network architecture is shown in any of the accompanying figures. For example, the called UE described in the various embodiments of this document can be... Figure 1 , Figure 2 , Figures 3A-3C The UE in the called network shown in any of the accompanying figures; the calling UE described in the various embodiments of this document can be... Figure 1 , Figure 2 , Figures 3A-3C The UE within the calling network shown in any of the accompanying figures; the first network element described in the various embodiments of this document can be... Figure 1 or Figure 2 The IMS AS, S-CSCF, P-CSCF, SMSF, IP-SM-GW shown, or may be Figure 2 The AF shown may be... Figure 1 The MSC / VLR shown, or the first network element, may be included in Figures 3A-3C In any of the core network devices shown in the accompanying figures; the second network element described in the various embodiments of this document may be Figure 1 The MME shown, or Figure 2The AMF shown, or the second network element, can be included in Figures 3A-3C In any of the core network devices shown in the attached diagram.

[0098] This application provides a communication method, please refer to... Figure 4 Here is a flowchart of the method.

[0099] S401, The first network element receives the first request from the calling UE.

[0100] The first request can be used to request a first service, such as a voice service provided by an operator, or an SMS service provided by an operator, or other services, such as application services provided by a third party, such as voice or video services corresponding to instant messaging software.

[0101] Taking a call as the primary service as an example, the first request might be a call request or a call invitation message, such as a SIP Initiation Invitation (INVITE) message. The call service is initiated, for example, by the calling UE, combined with... Figure 1 or Figure 2The transmission path of the call service-related request message includes, for example, the following: the calling UE sends a call request, which is, for example, a SIP Initial INVITE request message; the SIP Initial INVITE request message travels through the IMS-AGW in the network serving the calling UE (referred to as the calling network) to the P-CSCF in the calling network; the P-CSCF forwards the SIP Initial INVITE request message to the S-CSCF in the calling network; the S-CSCF triggers the IMS AS in the calling network and then returns to the S-CSCF (for example, the S-CSCF sends the SIP Initial INVITE request message to the IMS AS, and the IMS AS then sends the SIP Initial INVITE request message to the S-CSCF); the S-CSCF then routes the SIP Initial INVITE request message to the I-CSCF in the network serving the called UE (referred to as the called network); the I-CSCF routes the Initial INVITE request message to the S-CSCF in the called network; the S-CSCF triggers the IMS in the called network. The AS then returns to the called S-CSCF (for example, the S-CSCF sends the SIP Initial INVITE Request message to the IMS AS, and the IMS AS then forwards the SIP Initial INVITE Request message to the S-CSCF). The SIP Initial INVITE Request message then reaches the called UE via the P-CSCF within the called network. In various embodiments of this application, the calling network may include one or more of the following: an IMS serving the calling UE, an access network (e.g., RAN) serving the calling UE, a core network (e.g., 5GC or EPC) serving the calling UE, or a SMS network serving the calling UE (including SMS service network elements serving the calling UE, etc.). The called network may include one or more of the following: an IMS serving the called UE, an access network (e.g., RAN) serving the called UE, a core network (e.g., 5GC or EPC) serving the called UE, or an SMS network serving the called UE (including SMS service network elements serving the called UE, etc.).

[0102] For example, if the first network element is an IMS AS within the called network, then the first network element can receive the first request from the S-CSCF within the called network. As another example, if the first network element is an S-CSCF within the called network, then the first network element can receive the first request from the I-CSCF within the called network. And as yet another example, if the first network element is a P-CSCF within the called network, then the first network element can receive the first request from the S-CSCF within the called network.

[0103] Taking SMS as an example, the first request might include an SMS message. The SMS service can include a Mobile Originated (MO) procedure and a Mobile Terminated (MT) procedure. The MO procedure includes the process of the SMS message arriving from the calling UE to the SMSC within the calling network; the MT procedure includes the process of the SMS message arriving from the SMSC within the calling network to the called UE. The execution scheme for the SMS service can include a Non-Access Stratum (NAS) SMS scheme and an IMS SMS scheme, where the IMS SMS scheme involves the IP-SM-GW. 5G and 4G networks each have their own NAS SMS schemes; the 5G NAS SMS scheme involves the SMSF, and the 4G NAS SMS scheme involves the Mobile Switching Center (MSC) / Visitor Location Register (VLR).

[0104] The NAS SMS scheme in 5G networks includes the MO (Mobile Operation) and MT (Mobile Transmission) procedures. In the MO procedure, when the UE (also known as the calling UE) is in connection management-idle (CM_IDLE) mode, the UE and the AMF (Active Mobile Message Service) within the calling network can first establish a NAS signaling channel by triggering a service request procedure through the UE. Then, the calling UE generates an SMS message and encapsulates it in uplink NAS signaling before sending it to the AMF. Upon receiving the SMS message, the AMF can invoke the uplink short message service operation (Nsmsf_SMService_UplinkSMS) provided by the SMSF to send the SMS message to the SMSF serving the calling UE within the calling network. Upon receiving the SMS message, the SMSF can send it to the interworking MSC (Mobile Switching Center for Short Message Service) corresponding to the calling UE's home PLMN (HPLMN). The SMS-IWMSC can call the N1N2 message transfer service operation (Namf_Communication_N1N2MessageTransfer) provided by the AMF to send a Control Protocol (CP) response to the AMF, indicating that the SMS has been sent. The AMF can send an acknowledgment message to the calling UE via downlink NAS signaling. If the SMS-IWMSC and SMSC are deployed separately, the SMS-IWMSC will forward the SMS to the SMSC serving the calling UE. The SMSC or SMS-IWMSC can send a SMS submission report to the SMSF. The SMSF can call the Namf_Communication_N1N2MessageTransfer service operation request provided by the AMF to send an SMS SubmitReport to the AMF. The AMF sends an SMS Submit Report to the calling UE via downlink NAS signaling. The calling UE sends a Submit Report to the AMF via uplink NAS signaling to receive acknowledgment. The AMF calls the Nsmsf_SMService_UplinkSMS service operation request provided by the SMSF to send a Submit to the SMSF. Report received confirmation.

[0105] In the MT process of the NAS SMS scheme in a 5G network, the SMSC in the calling network sends the SMS to the SMS gateway, which is, for example, the Short Message Service-Gateway MSC (SMS-GMSC). The SMS gateway queries the UDM of the SMS recipient UE (also known as the called UE) to determine the SMSSF serving the called UE. The SMS gateway sends the SMS to the SMSSF. The SMSSF queries the SMS subscription data of the called UE. If it determines that the called UE has SMS permissions, it can invoke the mobile termination service enable reachability operation (Namf_MT_EnableUEReachability) provided by the AMF serving the called UE to request to send the SMS to the AMF. The called UE may currently be in CM_IDLE state, and the AMF can page the called UE. When a UE is called, the called UE attaches to the network; the AMF returns a Namf_MT_EnableUEReachability response to the SMSF, where the response may carry a failure indication if the called UE is unreachable; the SMSF invokes the Namf_Communication_N1N2MessageTransfer service provided by the AMF to send an SMS to the AMF serving the called UE; the AMF sends the SMS to the called UE via downlink NAS signaling; the called UE sends an SMS receipt confirmation message to the AMF via uplink NAS signaling.

[0106] The AMF invokes the Nsmsf_SMService_UplinkSMS service operation request provided by the SMSF to send an acknowledgment message to the SMSF; the called UE sends a delivery report to the AMF via uplink NAS signaling; the AMF invokes the Nsmsf_SMService_UplinkSMS service operation request provided by the SMSF to send the delivery report to the SMSF, wherein, if the SMS delivery fails, the delivery report may carry a failure indication; the SMSF sends the delivery report to the SMSC in the calling network via SMS-GMSC; the SMSF returns a delivery report acknowledgment message to the AMF via the Namf_Communication_N1N2MessageTransfer service operation request provided by the AMF; the AMF sends the delivery report acknowledgment message to the called UE via downlink NAS signaling.

[0107] For example, if the first network element is an SMSF within the called network, then the first network element can receive the first request (e.g., SMS) from the SMS gateway.

[0108] The NAS SMS scheme for 4G networks includes the MO procedure and the MT procedure. In the MO procedure, the calling UE has already completed the joint attachment of EPS / International Mobile Subscriber Identity (IMSI) before initiating the calling SMS. If the calling UE is in CM_IDLE state, it needs to perform a Service Request procedure before sending an SMS, accompanied by the establishment of an air interface radio resource control (RRC) connection and an S1 signaling connection. The calling UE sends an Uplink NAS Transport message to the MME, and the relevant SMS information can be carried as parameters in a NAS message container. This NAS message container is included in the NAS message, and the relevant SMS information includes, for example, control protocol data (CP data), relay protocol data (RP data), transport protocol data unit (TPDU), or SMS-SUBMIT. The MME queries the calling UE's SGs interface association information, determines the target MSC, and sends SGs Application Protocol Uplink Unit data (SGsAP Uplink Unit data) to that MSC, which includes the NAS message container. The MME also provides the MSC with the parameters International Mobile Equipment Identity Software Version (IMEISV), the local time zone, and the Mobile Station Class Identifier 2 (the The MSC uses one or more of the following parameters to generate call detail records: MobileStation Classmark 2, Tracking Area Identity (TAI), or Extended Cell Global Identifier (ECGI); the MSC sends SGs Application Protocol Downlink Unit data to the MME to confirm receipt of the SMS message; the MME can then send the NAS message within the SMS message to the UE via Downlink NAS Transport; the MSC sends the SMS message to the SMS-IWMSC; the SMS-IWMSC then sends the SMS message to the SMSC.The SMSC sends a delivery report to the SMS-IWMSC; the SMS-IWMSC sends the delivery report to the MSC; the MSC sends the delivery report to the MME; the MME sends the delivery report to the UE via Downlink NAS Transport; the UE sends a Downlink NAS Transport message to the MME to acknowledge receipt of the delivery report; the MSC sends an SGsAP Release Request message to the MME to indicate that there are no remaining NAS messages to exchange regarding the calling UE.

[0109] In the MT process of the NAS SMS scheme in a 4G network, the called UE completes the joint attachment of EPS / IMSI. The SMSC in the calling network sends the SMS to the SMS gateway, such as the SMS-GMSC; the SMS gateway sends the SMS to the HSS / Home Location Register (HLR) serving the called UE; the HSS / HLR sends the SMS to the MSC / VLR serving the called UE; the MSC / VLR queries the SGs interface association information of the called UE and sends an SGsAP Paging Request message to the MME serving the called UE, which carries a service indicator indicating that the current service is SMS; the MME sends a paging message to the access network equipment serving the called UE, which may include information such as the Short Temporary Mobile Subscriber Identity (S-TMSI) and the Core Domain Indicator (CN Domain Indicator). In this scenario, the MME also sets the CN Domain. The indicator is "PS"; the access network device sends a paging message to page the called UE; the called UE responds to the paging message and initiates a service request process, accompanied by the establishment of an air interface RRC signaling connection and an S1 signaling connection; the MME sends an SGsAP Service Request message to the MSC / VLR to indicate that NAS messages can be transmitted between the UE and the MME. Additionally, the MME can send one or more of the following parameters to the MSC / VLR: IMEISV, the local time zone, the Mobile Station Classmark 2, TAI, or ECGI, to generate call detail records (CDRs); the MSC / VLR sends an SGsAP Alert Request message to the MME to request notification of the MSC after the called UE contacts the MME; after the UE interacts with the MME, the MME sends an SGsAP UE Activity Indication message to the MSC / VLR; the MSC / VLR sends a MAP Ready For SM message to the HLR to notify the UE that its status is reachable; the MSC / VLR sends an SGsAP Downlink message to the MME. Unitdata messages, in which SMS messages are packaged as parameters in the NAS message container included in the SGsAP Downlink Unitdata message;The MME sends the SMS message from the SGsAP DownlinkUnitdata message to the called UE via a Downlink NAS Transport message; the called UE responds to the MSC / VLR to confirm receipt of the SMS message; the called UE sends a delivery report to the MME; the MME sends the delivery report to the MSC / VLR; the MSC / VLR sends the delivery report to the SMSC, where, if the SMS message delivery fails, the MSC / VLR can include a failure indication in the delivery report; the MSC / VLR sends a delivery report confirmation message to the called UE through the MME; the MSC / VLR sends an SGsAP Release Request message to the MME, indicating that there are no remaining NAS messages to exchange regarding the called UE.

[0110] For example, if the first network element is an MSC / VLR within the called network, then the first network element can receive the first request (e.g., SMS) from an SMS-GMSC or HSS / HLR.

[0111] The IMS SMS solution includes the MO (Mobile Origin) and MT (Mobile Transmission) procedures. In the MO procedure, after the calling UE composes an SMS message, it sends a SIP MESSAGE request message to the P-CSCF (Personal Controller CF) within the calling network. This MESSAGE request message carries the SMS message. The P-CSCF forwards the MESSAGE request message to the S-CSCF (Single Controller CF) within the calling network. The S-CSCF, based on the IP-SM-GW address information carried in the initial filter criteria (iFC) data downloaded from the HSS during the calling UE's registration, sends the MESSAGE request message to the IP-SM-GW within the calling network. The IP-SM-GW is the IP-SM-GW within the calling network. The IP-SM-GW then retrieves the message from the message body... The IP-SM-GW obtains the SMSC address information and the called UE's number from the body of the SMSC, constructs a MAP_MO_FORWARD_SM_REQ message, which can carry the RP-DATA from the body of the SMSC request message. The IP-SM-GW sends the MAP_MO_FORWARD_SM_REQ message to the SMSC. The IP-SM-GW returns a 202 accepted response to the calling UE to indicate that the IP-SM-GW has received the SMS. The SMSC replies to the IP-SM-GW with a MAP_MO_FORWARD_SM_CNF message. The IP-SM-GW sends an SMSC request message to the calling UE as a response to the SMS from the calling UE. The calling UE returns a 200 OK response to the IP-SM-GW.

[0112] In the MT procedure of the IMS SMS scheme, after receiving the SMS, the SMSC, based on the called UE's MSISDN, sends a MAP routing information message (MAP_SEND_ROUTING_INFO_FOR_SM_IND) to the converged HLR / HSS within the called UE's home domain to obtain the routing information for the SMS. The converged HLR / HSS forwards the MAP_SEND_ROUTING_INFO_FOR_SM_IND message to the IP-SM-GW based on the IP-SM-GW address registered by the called UE during third-party registration. The IP-SM-GW checks the called UE's SMS service information and IMSI information, and can perform domain selection based on the called UE's data configuration to determine the called UE's receiving domain; in this procedure, the priority receiving domain is the IMS domain. The IP-SM-GW constructs a MAP_SEND_ROUTING_INFO_FOR_SM message and sends the routing information back to the SMSC. Upon receiving this message...

[0113] Following the MAP_SEND_ROUTING_INFO_FOR_SM message, based on the GT address information of the IP-SM-GW carried in the message, a MAP_MT_FORWARD_SM_IND message is sent to the IP-SM-GW. The IP-SM-GW then sends a MESSAGE request message to the called UE. If the MESSAGE message fails to be sent, the IP-SM-GW, S-CSCF, or P-CSCF may generate an error response message. (Note that a timer can be set within the IP-SM-GW, S-CSCF, or P-CSCF to wait for a response to the MESSAGE request message; if this timer expires, the IP-SM-GW, S-CSCF, or P-CSCF may generate an error response message.) If no response to the MESSAGE request message is received when the timer expires, the IP-SM-GW, S-CSCF, or P-CSCF may generate an error response message. Alternatively, if the MESSAGE request message fails to be sent, the IP-SM-GW may receive an error response message from the S-CSCF, and the S-CSCF may also receive an error response message from the P-CSCF. Which network element generates the error response message depends on the duration configuration of its respective timer. The called UE returns a 200 OK response to the IP-SM-GW. The called UE encodes the SMS reception status into a MESSAGE request message based on the SMS reception status and sends the MESSAGE request message to the IP-SM-GW. The IP-SM-GW then sends the message to the SMSC.

[0114] The MAP_MT_FORWARD_SM response message indicates that SMS forwarding is complete; the IP-SM-GW returns a 202 response to the called UE; the converged HLR / HSS receives the Report-SM-DELIVERY-STATUS message from the SMSC and IP-SM-GW respectively. The converged HLR / HSS can process the reported status based on the status reported by the IP-SM-GW and send response messages to the IP-SM-GW and SMSC.

[0115] For example, if the first network element is an IP-SM-GW, then the first network element can receive the first request from the converged HLR / HSS (e.g., the MAP_SEND_ROUTING_INFO_FOR_SM_IND message), or it can receive the first request from the SMSC (e.g., the MAP_MT_FORWARD_SM_IND message).

[0116] Let's take the first service as an application-based service as an example. The calling UE sends a service request message to the application server (AS), which can be considered equivalent to an AF; the AS sends the service request message to the called UE; the called UE returns a service response message to the AS; and the AS returns the service response message to the calling UE. If the called UE's response times out, the AS can detect that the service has failed.

[0117] For example, if the first network element is AF, then the first network element can receive the first request from the calling UE (e.g., a service request message).

[0118] S402. After receiving the first request, the first network element sends request A to the called UE. If request A is successfully transmitted, the called UE can receive request A; if request A fails to be transmitted, the called UE may not receive request A. Figure 4 Take the called UE receiving request A as an example.

[0119] In this context, request A may be, for example, the first request, or a message generated by the first network element based on the first request. Figure 4 Taking request A as the first request as an example. The first network element sending the first request to the called UE can be understood as the first network element hoping that the first request can reach the called UE. The first request can reach the called UE directly from the first network element, or it can reach the called UE through one or more network elements.

[0120] Taking a voice call as an example. For instance, if the first network element is an IMS AS within the called network, then in S402, the first network element can send a first request to the S-CSCF within the called network. As another example, if the first network element is an S-CSCF within the called network, then in S402, the first network element can send a first request to the P-CSCF within the called network. And as yet another example, if the first network element is a P-CSCF within the called network, then in S402, the first network element can send a first request to the called UE.

[0121] Taking SMS service as an example. If the first network element is the SMSF within the called network, then in S402, the first network element can send a first request to the AMF within the called network. As another example, if the first network element is the IP-SM-GW within the called network, then in S402, the first network element can send a first request to the SMSC within the called network, or to the called UE. As yet another example, if the first network element is the MSC / VLR within the called network, then in S402, the first network element can send a first request to the MME serving the called UE within the called network.

[0122] Taking an application-based service as an example, if the first network element is AF, then in S402, the first network element can send a first request to the called UE.

[0123] S403. After determining that the first service has failed, the first network element sends a first message to the second network element in the core network. Correspondingly, the second network element receives the first message. This first message can trigger the second network element to send a flexible notification to the called UE.

[0124] The first network element can determine whether the first service succeeded or failed based on the execution status of S402. If the first service failed, S403 can be executed. Therefore, S403 can occur after S402. If the first service failed, the first network element can send a first message to the second network element to remind the called UE; conversely, if the first service did not fail, the first network element does not need to send the first message, and the second network element does not need to send a flexible notification to the called UE. This reduces interference to the called user and also reduces the power consumption of the called UE due to receiving flexible notifications.

[0125] Among them, when the first network element is different, the way the first network element determines the failure of the first service may also be different.

[0126] Optionally, one possible implementation of the first network element determining the failure of the first service includes the first network element receiving a second message, based on which the first network element can determine the failure of the first service. Optionally, the second message may indicate the failure of the first service (for example, if the first service is a call service, the second message may indicate call failure or call failure; if the first service is an SMS service, the second message may indicate SMS service failure or SMS sending failure, etc.), or indicate a request timeout, or indicate a timer timeout, etc. The timer, for example, is a first timer, which can be used to determine whether the first service has failed, or to wait for a response message corresponding to the first service (e.g., waiting for a response message corresponding to the first request). Optionally, the second message indicates the failure of the first service, and the reason for the failure of the first service may be a request timeout, a first timer timeout, or other reasons. The second message can be generated by the called UE and sent directly to the first network element, or it can be generated by an intermediate network element between the called UE and the first network element and sent to the first network element (for example, if the timer maintained by the intermediate network element expires, the intermediate network element can generate the second message. The intermediate network element may send the first message directly to the first network element, or it may send the first message to the first network element through another intermediate network element), or it can be generated by the called UE and sent to the first network element through a corresponding intermediate network element.

[0127] Alternatively, another optional implementation for the first network element to determine the failure of the first service includes the first network element determining the failure of the first service based on a first timer. The first timer is used to determine whether the first service has failed, or to wait for a response message corresponding to the first service (e.g., waiting for a response message corresponding to a first request). For example, if the first network element does not receive a response message corresponding to the first service (e.g., a response message corresponding to a first request) when the first timer expires, the first network element determines that the first service has failed; however, if the first network element receives a response message corresponding to the first service (e.g., a response message corresponding to a first request) before the first timer expires, the first network element may not consider the first service to have failed, and optionally, the first network element may stop the first timer.

[0128] Taking the first service as a call service as an example, the second message can optionally be a SIP error response message, which may include response codes such as 4XX, 5XX, or 6XX. Specifically, 4XX response codes indicate client errors, with values ​​ranging from 400 to 499; 5XX response codes indicate server errors, with values ​​ranging from 500 to 599; and 6XX response codes indicate global failures, with values ​​ranging from 600 to 699. The transmission path of the SIP error response message includes, for example, the following: if the called UE fails to process the first request, the called UE can send the SIP error response message; the SIP error response message arrives at the P-CSCF in the called network; the P-CSCF forwards the SIP error response message to the S-CSCF in the called network; the S-CSCF triggers the IMS AS in the called network and then returns to the S-CSCF (for example, the S-CSCF sends the SIP error response message to the IMS AS, and the IMS AS then sends the SIP error response message to the S-CSCF); the S-CSCF then forwards the SIP error response message to the I-CSCF in the called network; the I-CSCF routes the SIP error response message to the S-CSCF in the calling network; the S-CSCF triggers the IMS AS in the calling network and then returns to the S-CSCF (for example, the S-CSCF sends the SIP error response message to the IMS AS, and the IMS AS then sends the SIP error response message to the S-CSCF); the S-CSCF then forwards the SIP error response message to the I-CSCF in the called network; the I-CSCF routes the SIP error response message to the S-CSCF in the calling network; the S-CSCF triggers the IMS AS in the calling network and then returns to the S-CSCF (for example, the S-CSCF sends the SIP error response message to the IMS AS, and the IMS AS then sends the SIP error response message to the IMS AS). The AS then sends the SIP error response message to the S-CSCF, which in turn forwards it to the P-CSCF within the calling network. The SIP error response message then reaches the calling UE via the IMS-AGW within the calling network. Optionally, the SIP error response message may indicate, for example, that the first service has failed.

[0129] The above transmission path is based on the example of the called UE generating the SIP error response message. Alternatively, the called UE may not have received the first request; in this case, the called UE is unaware of the first request and the failure of the first service, and therefore does not generate the SIP error response message. For example, the SIP error response message may be generated by the IMS AS, S-CSCF, or P-CSCF within the called network based on the timeout of the first timer. Optionally, the SIP error response message may indicate the failure of the first service or indicate that the request has timed out. For example, the IMS AS starts the first timer when sending the first request to the S-CSCF within the called network or after sending the first request. The first timer corresponding to the IMS AS may also be called timer A. When timer A times out, if the IMS AS does not receive a response message (e.g., a success response) corresponding to the first request, the IMS AS can generate the SIP error response message, which may indicate the failure of the first service, the timer A timeout, or the request timeout. The transmission path of the SIP error response message can be referred to in the previous paragraph.

[0130] For example, when the S-CSCF sends a first request to the P-CSCF in the called network, or after sending the first request, it starts a first timer. This first timer for the S-CSCF is also called timer B. When timer B expires, if the S-CSCF does not receive a response message (e.g., a success response) corresponding to the first request, it can generate a SIP error response message. This SIP error response message can indicate that the first service has failed, that timer B has expired, or that the request has timed out. The transmission path of this SIP error response message can be found above.

[0131] For another example, when the P-CSCF sends a first request to the called UE or after sending the first request, it starts a first timer. This first timer for the P-CSCF is also called timer C, for example. When timer C expires, if the P-CSCF does not receive a response message (e.g., a success response) corresponding to the first request, it can generate a SIP error response message. This SIP error response message can indicate that the first service has failed, that timer C has expired, or that the request has timed out. The transmission path of this SIP error response message can be found above.

[0132] For example, if the first network element is an IMS AS within the called network, the IMS AS can receive a second message from the S-CSCF within the called network, and can determine that the first service has failed based on the second message. Alternatively, the IMS AS can determine that the first service has failed based on the timer A timeout. Optionally, the second message may indicate that the first service has failed, that timer A has timed out, or that the request has timed out, etc.

[0133] For example, if the first network element is an S-CSCF within the called network, the S-CSCF can receive a second message from a P-CSCF within the called network, and can determine that the first service has failed based on the second message. Alternatively, the S-CSCF can determine that the first service has failed based on the timer B timeout. Optionally, the second message can indicate that the first service has failed, that timer B has timed out, or that the request has timed out, etc.

[0134] For example, if the first network element is a P-CSCF within the called network, the P-CSCF can receive a second message from the called UE, and determine the failure of the first service based on the second message. Alternatively, the P-CSCF can determine the failure of the first service based on the timer C timeout. Optionally, the second message can indicate the failure of the first service, the timer C timeout, or the request timeout, etc.

[0135] Taking SMS service as an example, the first network element is, for example, the SMS service network element.

[0136] For example, if the SMS service network element is the SMSF within the called network, according to the NAS SMS solution for 5G networks described in S401, the SMSF can receive SMS transmission reports from the AMF. If SMS transmission fails, the SMS transmission report can carry a failure indication (for example, an SMS transmission report carrying a failure indication can be considered a second message, or the failure indication can be considered a second message). Therefore, the SMSF can determine that the first service has failed. Optionally, the second message can indicate that the first service has failed or indicate a request timeout, etc. Optionally, the reason for the first service failure may be SMS transmission failure or request timeout, etc.

[0137] For example, if the SMS service network element is an IP-SM-GW within the called network, according to the IMS SMS solution described in S401, the IP-SM-GW can receive SIP error responses from the S-CSCF. Based on these SIP error responses, the first service failure can be determined (e.g., the SIP error response can be considered a second message). Alternatively, the IP-SM-GW can determine the first service failure based on the timeout of the first timer within the IP-SM-GW (e.g., the first timer within the IP-SM-GW is also called timer D). Optionally, the second message can indicate the first service failure, a request timeout, or timer D timeout, etc. Optionally, the reason for the first service failure might be SMS sending failure, a request timeout, or timer D timeout, etc.

[0138] For example, if the SMS service network element is the MSC / VLR within the called network, according to the NAS SMS scheme for 4G networks described in S401, the MSC / VLR can receive transmission reports from the MME. If SMS transmission fails, the transmission report can carry a failure indication. Therefore, the MSC / VLR can determine that the first service has failed (for example, an SMS transmission report carrying a failure indication can be considered a second message, or the failure indication can be considered a second message). Optionally, the second message can indicate that the first service has failed or indicate a request timeout, etc. Optionally, the reason for the first service failure may be SMS transmission failure or request timeout, etc.

[0139] Taking an application-based service as an example, if the first network element is the AF (Automatic AF), and according to the transmission process of application-based services described in S401, the AF can automatically detect the failure of the first service.

[0140] In this embodiment, the flexible notification can indicate more information than a paging message, such as information indicating a first service and / or information about the calling UE. The called UE, upon receiving the corresponding information indicating the first service and / or the calling UE, can output this information, allowing the called user to determine whether to respond to the first service. For example, the called user can determine whether the first service needs to be executed based on factors such as the importance of the first service and / or the identity of the calling UE. If the called user believes that the first service does not need to be executed, the called user does not need to respond, for example, by not needing to align the called UE with a satellite, thereby reducing the power consumption of the called UE and minimizing interference to the user.

[0141] The information of the calling UE indicated by the flexible notification, such as the identifier of the calling UE, may include the public identifier and / or private identifier of the calling UE, without limitation. Among them, the public identifier of a UE may include, for example, the generic public subscription identifier (GPSI) and / or the Internet protocol multimedia public identity (IMPU) of the UE; the private identifier of a UE may include, for example, the globally unique temporary UE identity (GUTI) and / or the subscription permanent identifier (SUPI) and / or the IMS private identifier (IMPI) of the UE, etc.

[0142] Optionally, the second network element may be, for example, the MME within the EPC, or the AMF within the 5GC. The first network element can directly send the first message to the second network element. Alternatively, the first network element can also send the first message to other network elements to achieve the purpose of sending a message to the second network element. For example, if the first network element cannot communicate directly with the second network element, it can send the first message to the third network element. The first message can be used to trigger the third network element to send a flexible notification to the called UE. After receiving the first message, the third network element can send a message to the second network element, for example, message a. Message a can be used to trigger the second network element to send a flexible notification to the called UE. Alternatively, if the third network element also cannot communicate directly with the second network element, then after receiving the first message, it can send a message to the fourth network element, for example, message b. Message b can be used to trigger the fourth network element to send a flexible notification to the called UE. After receiving message b, the fourth network element then sends a message to the second network element, for example, message c. Message c can be used to trigger the second network element to send a flexible notification to the called UE, and so on. This can be understood as the first network element and the second network element being able to communicate directly, or they can communicate through one or more intermediate network elements.

[0143] When the first network element is different, the intermediate network elements traversed between the first and second network elements can also differ. Taking a voice call service as an example: if the first network element is an IMS AS or S-CSCF within the called network, and the second network element is an MME within the called network, then the intermediate network elements between the first and second network elements may include an HSS; or, if the second network element is an AMF, then the intermediate network elements between the first and second network elements may include a UDM within the called network. As another example, if the first network element is a P-CSCF within the called network, and the second network element is an MME within the called network, then the intermediate network elements between the first and second network elements may include a PCRF, PGW, and SGW within the called network; or, if the second network element is an AMF, then the intermediate network elements between the first and second network elements may include a PCF and SMF within the called network.

[0144] Taking SMS service as an example. For example, if the first network element is an SMSF or IP-SM-GW in the called network, and the second network element is an MME in the called network, the intermediate network element between the first and second network elements may include an HSS in the called network; or, if the second network element is an AMF in the called network, the intermediate network element between the first and second network elements may include a UDM in the called network.

[0145] Taking application-type services as an example, the first network element is AF, the second network element is AMF, and the intermediate network element between the first and second network elements may include NEF in the called network, or may include NEF and UDM in the called network.

[0146] The first message can be a message corresponding to a service interface, in which case the core network where the second network element is located is, for example, 5GC; or, the first message can be a message corresponding to a non-service interface, in which case the core network where the second network element is located is, for example, EPC.

[0147] Taking the first message as the message corresponding to the service interface as an example, the first message can have different implementations. For example, if the first message is sent from a first network element to an intermediate network element (e.g., a third network element), then the first message can be a message based on a first service, which can be a service provided by the third network element. The first service can be dedicated to triggering elastic notifications, or it may not be dedicated to triggering elastic notifications but have other uses. This application embodiment can utilize the first service to trigger elastic notifications. Optionally, if the first service is dedicated to triggering elastic notifications, the first message may include one or more of the following: information indicating a first service, information indicating the calling UE, or information indicating the called UE. Alternatively, if the first service is not dedicated to triggering elastic notifications, the first message may include one or more of the following: elastic notification indication information, information indicating a first service, information indicating the calling UE, or information indicating the called UE. The information indicating the called UE may be, for example, the called UE's identifier, such as the called UE's SUPI, GPSI, IMPU, IMPI, or GUTI. The flexible notification instruction information can instruct the initiation of the flexible notification process, or instruct the sending of a flexible notification, or instruct the sending of a flexible notification to the called UE.

[0148] Alternatively, the first message can be a message based on a second service, which can be a service provided by a first network element. The second service may be dedicated to triggering elastic notifications, or it may not be dedicated to triggering elastic notifications but have other uses. This application embodiment can utilize the second service to trigger elastic notifications. Optionally, if the second service is dedicated to triggering elastic notifications, the first message may include one or more of the following: information indicating a first service, information indicating the calling UE, or information indicating the called UE. Alternatively, if the second service is not dedicated to triggering elastic notifications, the first message may include one or more of the following: elastic notification indication information, information indicating a first service, information indicating the calling UE, or information indicating the called UE.

[0149] If the first message is based on the second service, optionally, the third network element can first subscribe to the elastic notification event from the first network element. For example, the third network element can send a first subscription request to the first network element, which can be used to request subscription to the start elastic notification event. If the first network element receives the first subscription request, it can send a first message to the third network element upon receiving the first request (described later) or upon determining that the first service has failed. Optionally, the first message can be regarded as a notification request for the event subscribed to by the first subscription request.

[0150] Taking the first message as an example of a message corresponding to a non-service interface, the first message can also have different implementations. For example, if the first message is sent from a first network element to an intermediate network element (e.g., a third network element), then the first message can be a message based on a first interface. The first interface can be a communication interface between the first network element and the third network element, and the first interface is a non-service interface. This message based on the first interface can be dedicated to triggering elastic notifications, or it may not be dedicated to triggering elastic notifications but have other uses. This embodiment of the application can utilize this message to trigger elastic notifications. Optionally, if the first message is dedicated to triggering elastic notifications, then the first message may include one or more of the following: information indicating a first service, information indicating the calling UE, or information indicating the called UE. Alternatively, if the first message is not dedicated to triggering elastic notifications, then the first message may include one or more of the following: elastic notification indication information, information indicating a first service, information indicating the calling UE, or information indicating the called UE.

[0151] In this embodiment, the first network element can execute S403 if it determines that the first service has failed. Conversely, if the first network element determines that the first service has succeeded, it can skip executing S403. If the first service is successful, it indicates that the called UE has already established communication with the calling UE, or that the called UE is aware that the first service has arrived. Therefore, it is unnecessary to remind the called UE through a flexible notification. This implementation reduces interference to the called user, reduces power consumption of the called UE due to receiving flexible notifications, and saves on the transmission overhead of flexible notifications.

[0152] Alternatively, the first network element may not need to determine whether the first service has succeeded or failed. For example, the first network element can send the first message to the second network element after executing 401. In this alternative, S403 can be replaced by: the first network element sending the first message to the second network element, and the second network element receiving the first message. That is, when the first network element determines that the called UE has a first service arriving, it can trigger the second network element to send a flexible notification to the called UE. This implementation can improve the sending efficiency of the flexible notification, enabling the called UE to know that the first service has arrived as soon as possible. Optionally, in this alternative, the first network element can still execute S402 to continue executing the first service. Optionally, S402 can occur before S403, after S403, or simultaneously with S403.

[0153] Optionally, before sending the first message to the second network element, the first network element can determine whether the called UE accesses the core network where the second network element is located via satellite. Optionally, the first network element can determine whether the called UE accesses the core network via satellite based on the called UE's access information. For example, the first network element can store the access information, or the first network element can request the access information from other network elements, such as HSS or UDM. Due to the long distance between satellite and the ground, the reliability of satellite communication is relatively low compared to terrestrial network communication scenarios. In the scenario where the called UE accesses the core network via satellite, if the called UE is paged via a paging message, the called UE may not receive the paging message due to its limited coverage. Therefore, in the scenario where the called UE accesses the core network via satellite, this embodiment of the application can send a flexible notification to the called UE. Compared to a paging message, the coverage of a flexible notification can be stronger, for example, by sending more flexible notifications and / or having higher transmission power, thereby increasing the probability that the called UE is paged.

[0154] If the called UE does not access the core network via satellite, but rather via a terrestrial network, the first network element does not need to send the first message. Terrestrial networks are more reliable than satellite networks, and the called UE has a higher probability of receiving the paging message. Therefore, the corresponding network element within the core network can page the called UE according to the paging procedure, without needing to remind the UE via elastic notification. Thus, the first network element does not need to send the first message, thereby saving the transmission overhead of elastic notification.

[0155] Optionally, before sending the first message to the second network element, the first network element may determine whether the information of the calling UE corresponding to the first service is included in the first information. The first information may include information of one or more UEs. The information of a UE may include, for example, the UE's identifier, such as the UE's GPSI, or the Mobile Station International Subscriber Directory Number (MSISDN), or other identifiers that can identify the UE. The UE corresponding to the information of one or more UEs included in the first information is a UE that is allowed to send flexible notifications. Taking the first service as a call service as an example, if the first information includes MSISDN1 and MSISDN2, it indicates that if the phone number of the calling UE corresponding to the first service is either of these two phone numbers, the first network element can trigger the second network element to send a flexible notification to the called UE; or, if the phone number of the calling UE corresponding to the first service is not included in the first information, the first network element does not need to trigger the second network element to send a flexible notification to the called UE.

[0156] Optionally, the first information may include only information about one or more UEs. Alternatively, the first information may include information about one or more UEs and corresponding indexes. For example, it can be understood as the first information including the correspondence between the information of one or more UEs and the indexes; or it can be understood as the first information including information about one or more UEs, and including one or more indexes, with the information of the one or more UEs corresponding one-to-one with the one or more indexes. In this case, an index can indicate the information of the UE corresponding to that index.

[0157] The first information can be understood as a whitelist, for example. Optionally, the first information can be set by the called UE. For example, the first information set for different called UEs can be the same or different. For instance, a user using a called UE can set the phone numbers of important users in the first information. If these phone numbers are used as calling numbers, the called UE can receive a flexible notification when using satellite access. Phone numbers not included in the first information may be phone numbers that the called UE (or the user using the called UE) considers unimportant or even nuisance numbers. If these phone numbers are used as calling numbers, the first network element does not need to trigger the second network element to send a flexible notification, thereby reducing the transmission overhead of the flexible notification. Optionally, even if the first network element triggers the second network element to send a flexible notification to the called UE based on a calling number not included in the first information, the called UE may not need to notify the called user after receiving the flexible notification. For example, if the called user has set the flexible notification notification to be disabled on the called UE, the flexible notification can be considered invalid information. Therefore, this embodiment of the application avoids the first network element triggering the second network element to send a flexible notification to the called UE based on a calling number not included in the first information, and also reduces the transmission of invalid information.

[0158] Optionally, after the called UE sets or updates the first information, it can store the first information in the data storage network element. Therefore, the first network element can obtain the first information from the data storage network element. For example, the first network element can send a request message A to the data storage network element. Request message A, for example, requests the first information. This request message A includes, for example, the information of the called UE, to indicate that the request is for the first information corresponding to the called UE. In response to the request message A, the data storage network element can send the first information back to the first network element. This data storage network element can be, for example, an HSS or UDM, or other network elements with data storage functions.

[0159] For example, if the called UE sets or updates the first information, it can send the first information to the second network element. The second network element is, for example, an AMF or an MME. Taking the second network element as an example, the UE can send the first information to the AMF via a NAS message. Upon receiving the first information, the AMF can send the first information to the data storage network element to store it there. Specifically, if the second network element is an MME, the data storage network element can be an HSS; or, if the second network element is an AMF, the data storage network element can be a UDM.

[0160] For example, if the second network element is AMF and the data storage network element is UDM, then AMF can call the parameter provision service (Nudm_ParameterProvision) provided by UDM to send the first information to UDM. The first information may be included in the update service operation (Nudm_ParameterProvision_Update) request message provided by UDM.

[0161] After receiving the first information, the data storage network element can also send a response, such as response A, to the second network element to indicate whether the first information was received successfully or not. For example, if the AMF calls the Nudm_ParameterProvision_Update request message to send the first information to the UDM, response A would be sent via the Nudm_ParameterProvision_Update response message.

[0162] After receiving response A, the second network element can also send a response, such as response B, to the called UE to indicate whether the first information setting was successful or failed. Taking the second network element as an example, the AMF can send response B to the called UE through a NAS message.

[0163] Optionally, the method may also include S404 and S405.

[0164] S404. After receiving the first message, the second network element sends a flexible notification to the access network device. Correspondingly, the access network device receives the flexible notification.

[0165] S405. After receiving the flexible notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0166] The access network device can be the access network device serving the called UE. That is, the first network element triggers the second network element to send a flexible notification to the called UE. Specifically, the second network element can send the flexible notification to the access network device, and then the access network device sends a third message to the called UE.

[0167] The flexible notification sent by the second network element to the access network device can instruct the access network device to send information indicating the first service and / or information indicating the calling UE to the called UE in a manner different from paging. For example, the flexible notification may include information indicating the first service and / or information indicating the calling UE, and may also include indication information A, which may instruct the access network device to send information indicating the first service and / or information indicating the calling UE to the called UE in a manner different from paging.

[0168] The flexible notification includes information indicating the first service, such as one or more of the following: the type of the first service, the identifier of the first service, or the name of the first service, etc., without limitation. For example, the type of the first service could indicate "incoming call" or "SMS", etc.

[0169] The flexible notification includes information indicating the calling UE, such as the calling UE's identifier, which may be the calling UE's MSISDN or other identifier. Alternatively, the flexible notification may include an index of the calling UE's information within the first information. For example, the second network element can obtain the first information from the data storage network element. If the calling UE's information is included in the first information, the second network element can determine the index of the calling UE's information within the first information and carry that index in the flexible notification. In this approach, the flexible notification does not necessarily need to include the calling UE's information; instead, it only needs to include the index corresponding to the calling UE's information, thereby reducing the transmission overhead of the flexible notification. Taking the UE's information as an example, the MSISDN can contain up to 15 numbers. Taking binary-coded decimal (BCD) encoding as an example, which occupies 7.5 bytes, if the first information provided by the operator can support the storage of a maximum of 8 MSISDNs, then the index of each of these 8 MSISDNs in the first information only needs to occupy 3 bits; or, if the first information provided by the operator can support the storage of a maximum of 16 MSISDNs, then the index of each of these 16 MSISDNs in the first information only needs to occupy 4 bits. It is evident that carrying the index in the flexible notification without carrying the calling UE's information can significantly reduce air interface overhead.

[0170] The method that differs from paging may include: the transmission power of the information used to indicate the first service and / or the information used to indicate the calling UE is greater than the transmission power of the paging message, and / or the number of times the information used to indicate the first service and / or the information used to indicate the calling UE is transmitted is greater than the number of times the paging message is transmitted.

[0171] For example, if the method differs from paging and is instead a flexible notification method, then the access network device can also send a flexible notification (i.e., the third message is a flexible notification). The flexible notification sent by the access network device may include information indicating the first service and / or information indicating the calling UE. For instance, the access network device may include the information indicating the first service and / or the information indicating the calling UE from the flexible notification from the second network element in the flexible notification sent by the access network device. The transmission power of the flexible notification sent by the access network device may be greater than the transmission power of the paging message, and / or the number of times the flexible notification is sent may be greater than the number of times the paging message is sent.

[0172] For example, if the notification method is different from paging and is other than flexible notification, then the access network device sends a different message (i.e., the third message is this other message), which may include information indicating the first service and / or information indicating the calling UE. For instance, the access network device may include the information indicating the first service and / or the information indicating the calling UE included in the flexible notification from the second network element in the other message sent by the access network device. The transmission power of this other message may be greater than the transmission power of the paging message, and / or the number of times the other message is sent may be greater than the number of times the paging message is sent.

[0173] As can be seen, the embodiments of this application do not limit the type and / or name of the third message sent by the access network device, as long as the third message meets the requirements of high transmission power and / or high transmission frequency, thereby improving the coverage of the third message and thus improving the success rate of the called UE in receiving the third message.

[0174] The called UE receives a third message from the access network equipment and, optionally, can output a prompt message. For example, the called UE can output the prompt message through ringing and / or a user interface (UI) to remind the called user. This prompt message may include information about the first service and / or the calling UE's information. Based on the information about the first service and / or the calling UE's information, the called user can determine whether to respond to the first service. If the called user decides to respond to the first service, they can perform satellite alignment with the satellite, which may improve the channel conditions between the called UE and the network equipment, thus enabling them to respond to the first service. Alternatively, if the called user decides not to respond to the first service, no processing is required, such as not performing satellite alignment, thereby reducing the called UE's power consumption and the called user's operations.

[0175] If the information included in the third message that indicates the calling UE is the index of the calling UE's information in the first message, the called UE can convert the index into the calling UE's information based on the first message, thereby including the calling UE's information in the prompt message.

[0176] Optionally, in addition to sending third messages, the access network device can also send paging messages, which can be used to page the called UE. This means the access network device can both page the called UE using paging messages and locate the called UE using third messages, increasing the probability that the called UE will be paged.

[0177] For example, if an access network device receives a flexible notification from a second network element, it can send a paging message. If no response is received from the called UE, the access network device can then send a third message; if a response is received from the called UE after sending the paging message, the access network device does not need to send the third message, thereby saving transmission overhead.

[0178] In this embodiment, the second network element can send a flexible notification to the called UE, and this flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, making the notification method more flexible. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. The called UE can output this information, so that the user using the called UE (e.g., the called user) can determine whether to execute the first service. For example, the called user can determine whether to execute the first service by determining the importance of the first service and / or the identity of the calling UE. It can be seen that this flexible notification can provide more basis for the called user's judgment, making the notification method more effective. If the called user believes that the first service does not need to be executed, the called user can avoid responding through the called UE, such as avoiding pairing the called UE with a satellite, thereby reducing the power consumption of the called UE. In addition, for users, performing pairing operations when using satellite access is relatively troublesome, especially when in remote mountainous areas, where it is necessary to find an unobstructed area to perform pairing operations. If the called UE is prompted to respond to every paging request from the network, it may cause interference to the user and result in a poor user experience. However, the embodiments of this application provide more information to the called user through flexible notifications. If the called user believes that it does not need to receive the first service, it does not need to perform star level operation, which can also reduce interference to the called user.

[0179] Furthermore, in this embodiment, the first network element can trigger the second network element to send an elastic notification only after determining that the first service has failed. This not only serves to remind the called user but also reduces interference to the called user. Alternatively, the first network element can trigger the second network element to send an elastic notification after receiving the first request, without needing to determine whether the first service has succeeded or failed. This implementation method can improve the sending efficiency of the elastic notification, enabling the called UE to be informed of the arrival of the first service as soon as possible.

[0180] To better understand the above solution, several embodiments are described below. The following sections will further elaborate on these embodiments. Figures 5-13 The method embodiments shown can all be considered as Figure 4 Examples of the embodiments shown, Figures 5-13 The method embodiments shown are examples of different implementations of the first network element.

[0181] This application provides a second communication method, please refer to the embodiments therein. Figure 5 The flowchart below illustrates this method. In this method, we take an example where the first network element is AF and the second network element is AMF within the called network.

[0182] S501, the AF receives a first request from the calling UE. The first request can be used to request a first service. In this embodiment, the first service is, for example, an application service, which is a service supported or provided by the AF.

[0183] Among them, S501 and Figure 4 S401 in the illustrated embodiment can be the same step; for more details, please refer to the corresponding description of S401.

[0184] After receiving the first request, S502 and AF send the first message to NEF. Correspondingly, NEF receives the first message. This NEF is the NEF within the called network.

[0185] This application embodiment takes the example of the AF sending the first message immediately after receiving the first request, that is, the AF sends the first message without determining whether the first service has failed. Alternatively, the AF may send the first message only after determining that the first service has failed. For example, after receiving the first request, the AF can send the first request to the called UE (this step is the same as...). Figure 4 In the illustrated embodiment, S402 can be the same step. Based on the sent first request, the AF can determine whether the first service succeeded or failed. If the first service failed, the AF can execute S502, which can be replaced by the following: after determining that the first service failed, the AF sends a first message to the NEF, and the NEF receives the first message. This S502 is consistent with... Figure 4In the illustrated embodiment, S403 can be the same step. For details regarding the AF sending the first request to the called UE and the AF determining whether the first service has failed, please refer to [link / reference needed]. Figure 4 S402 and S403 of the illustrated embodiment.

[0186] The first message can be used to trigger the NEF to send a flexible notification to the called UE. In this embodiment, the AF and AMF cannot communicate directly, and the NEF can act as an intermediate network element between the AF and AMF. Therefore, the first message of the AF can be sent to the NEF.

[0187] The first message can be based on a first service, which can be a service provided by NEF. In this embodiment, multiple network elements may provide corresponding first services, and the first services provided by different network elements may be different. For distinction, the first service provided by NEF is referred to as first service A. For example, first service A is a service specifically used to trigger resilient notifications, such as the NEF-provided Resilient Notification service (Nnef_StartResilientNotification). The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0188] Alternatively, the first service A can be a service provided by NEF, but it is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. For example, the first service A could be the NEF-provided Access and Mobility Management Policy Authorization service (Nnef_AMPolicyAuthorization), or it could be another service provided by NEF. The first message may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0189] S503. After receiving the first message, the NEF sends message A to the AMF. Correspondingly, the AMF receives message A. Message A can be used to trigger the AMF to send a flexible notification to the called UE. Optionally, message A is the first message; or, message A can also be a message generated by the NEF based on the first message, for example, message A may include the entire content of the first message; or, message A may include a portion of the first message, such as one or more of the following: flexible notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these information items, please refer to [link to relevant documentation]. Figure 4 S403 of the illustrated embodiment.

[0190] Upon receiving the first message, the NEF can determine the UDM instance serving the called UE by querying the network repository function (NRF) or based on local configuration. Then, by querying that UDM instance, it can determine the instance ID of the AMF instance serving the called UE. By querying the NRF or based on local configuration, it can determine the address information corresponding to this instance ID; this address information is the address information of the AMF serving the called UE. Therefore, the NEF can send message A to this address information.

[0191] Message A can be a message based on a first service, which can be a service provided by the AMF. For distinction, the first service provided by the AMF in this embodiment is referred to as first service B. For example, first service B is a service specifically for triggering resilient notifications, such as the AMF-provided start resilient notification service (Namf_StartResilientNotification). Message A may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0192] Alternatively, the first service B can be a service provided by the AMF, but it is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. For example, the first service B could be the mobile called service (Namf_MT) provided by the AMF, or it could be another service provided by the AMF. Message A may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0193] Alternatively, message A can be a message based on a second service, which can be a service provided by NEF. In this embodiment, multiple network elements may be able to provide corresponding second services, and the second services provided by different network elements may be different. For distinction, the second service provided by NEF in this embodiment is referred to as second service A. For example, second service A is a service specifically used to trigger resilient notifications. Second service A may be, for example, the resilient notification start service (Nnef_ResilientNotificationStart) provided by NEF, and message A may be, for example, the notification request message (Nnef_ResilientNotificationStart_Notify) provided by NEF. Message A may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0194] Alternatively, the second service A can be a service provided by NEF, but it is not a service specifically designed to trigger elastic notifications; rather, it reuses an existing service. For example, the second service A could be an event exposure service (Nnef_EventExposure) provided by NEF, and message A could be a notification request message for the event exposure service (Nnef_EventExposure_Notify) provided by NEF. Message A may include one or more of the following: elastic notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0195] If message A is based on the second service A, optionally, the AMF can first subscribe to elastic notification events from the NEF. For example, the AMF can send a first subscription request to the NEF, such as called First Subscription Request A. First Subscription Request A can be used to request subscription to elastic notification events. If the NEF receives First Subscription Request A, it can send message A to the AMF upon receiving the first request or upon determining that the first service has failed. Optionally, message A can be regarded as a notification request message for the events subscribed to by First Subscription Request A.

[0196] S502 and S503 and Figure 4 S403 in the illustrated embodiment can be the same step; for more details, please refer to the relevant description of S403.

[0197] S504. After receiving message A, the AMF sends a flexible notification to the access network device. Correspondingly, the access network device receives this flexible notification. This access network device can be the access network device serving the called UE.

[0198] S505. After receiving the flexible notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0199] Among them, S504 and Figure 4 In the illustrated embodiment, S404 can be the same step, and S505 is the same as... Figure 4 S405 in the illustrated embodiment can be the same step, so for more details, please refer to the relevant descriptions of S404 and S405.

[0200] After S506 and AMF send the elastic notification, they send response message 1 to NEF. NEF then receives response message 1.

[0201] Response message 1 can indicate whether the elastic notification was sent successfully or failed. Response message 1 can be considered a response to message A.

[0202] After receiving response message 1, S507 and NEF send response message 2 to AF. Correspondingly, AF receives response message 2.

[0203] Response message 2 can indicate whether the elastic notification was sent successfully or failed. The content indicated by response message 2 can be the same as that indicated by response message 1. Response message 2 can be considered a response to the first message.

[0204] In this embodiment, the AMF can send a flexible notification to locate the called UE. This flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, providing a flexible notification method. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. For example, the called UE can output this information, allowing the called user to determine whether to execute the first service. Therefore, this flexible notification provides more information for the called user's judgment, making the notification method more effective. For example, if the called user believes that the first service does not need to be executed, the called user does not need to respond, such as not needing to align the called UE with a satellite, thereby reducing the power consumption of the called UE and minimizing interference to the called user. Furthermore, in this embodiment, the AF can trigger the AMF to send the flexible notification only after determining that the first service has failed, thus both reminding the called user and reducing interference; alternatively, the AF can trigger the AMF to send the flexible notification after receiving the first request, without needing to determine whether the first service has succeeded or failed. This implementation method can improve the sending efficiency of the flexible notification, allowing the called UE to know that the first service has arrived as quickly as possible.

[0205] This application provides a third communication method; please refer to [reference needed]. Figure 6 The flowchart below illustrates this method. In this method, we take an example where the first network element is AF and the second network element is AMF within the called network.

[0206] S601, the AF receives a first request from the calling UE. The first request can be used to request a first service. In this embodiment, the first service is, for example, an application service, which is a service supported or provided by the AF.

[0207] Among them, S601 and Figure 4 S401 in the illustrated embodiment can be the same step; for more details, please refer to the corresponding description of S401.

[0208] After receiving the first request, S602 and AF send the first message to NEF. Correspondingly, NEF receives the first message. This NEF is the NEF within the called network.

[0209] This application embodiment takes the example of the AF sending the first message immediately after receiving the first request, that is, the AF sends the first message without determining whether the first service has failed. Alternatively, the AF may send the first message only after determining that the first service has failed. For example, after receiving the first request, the AF can send the first request to the called UE (this step is the same as...). Figure 4 In the illustrated embodiment, S402 can be the same step. Based on the sent first request, the AF can determine whether the first service succeeded or failed. If the first service failed, the AF can execute S602, which can be replaced by the following: after determining that the first service failed, the AF sends a first message to the NEF, and the NEF receives the first message. This S602 is consistent with... Figure 4 In the illustrated embodiment, S403 can be the same step. For details regarding the AF sending the first request to the called UE and the AF determining whether the first service has failed, please refer to [link / reference needed]. Figure 4 S402 and S403 of the illustrated embodiment.

[0210] The first message can be used to trigger the NEF to send a resilient notification to the called UE. In this embodiment, the AF and AMF cannot communicate directly; the NEF can act as an intermediary network element between the AF and AMF, so the AF's first message can be sent to the NEF. For more information on the first message, please refer to [link to relevant documentation]. Figure 5 S502 in the illustrated embodiment.

[0211] S603. After receiving the first message, the NEF sends message B to the UDM. Correspondingly, the UDM receives message B. Message B can be used to trigger the AMF to send a flexible notification to the called UE. Optionally, message B is the first message, or it can be a message generated by the NEF based on the first message. For example, message B may include the entire content of the first message; or, message B may include a portion of the first message, which may include one or more of the following: flexible notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these information items, please refer to [link to relevant documentation]. Figure 4 S403 of the illustrated embodiment.

[0212] The UDM is a UDM within the called network. In this embodiment, the AF and AMF cannot communicate directly. Both the NEF and the UDM can act as intermediate network elements between the AF and AMF, so the first message from the NEF can be sent to the UDM.

[0213] Upon receiving the first message, the NEF can determine the address information of the UDM instance serving the called UE by querying the network repository function (NRF) or by referring to the local configuration. The NEF can then send message B to that address.

[0214] Message B can be a message based on a first service, which can be a service provided by the UDM. For distinction, the first service provided by the UDM in this embodiment is referred to as first service C. For example, first service C is a service specifically used to trigger resilient notifications, and the name of first service C is, for example, Nudm_StartResilientNotification. Message B may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0215] Alternatively, the first service C can be a service provided by the UDM, but it is not a service specifically designed to trigger elastic notifications; rather, it reuses an existing service. For example, the first service C could be the user data management service (Nudm_SubscriberDataManagement, Nudm_SDM) provided by the UDM. Message B may include one or more of the following: elastic notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0216] Alternatively, message B can be a message based on a second service, which can be a service provided by NEF. For distinction, the second service provided by NEF in this embodiment is referred to as second service B. For example, second service B is a service specifically used to trigger resilient notifications, such as Nnef_ResilientNotificationStart, and message B is such as Nnef_ResilientNotificationStart_Notify. Message B may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0217] Alternatively, the second service B can be a service provided by NEF, but it is not a service specifically designed to trigger elastic notifications; instead, it reuses an existing service. For example, the second service B could be Nnef_EventExposure, and message B could be Nnef_EventExposure_notify. Message B may include one or more of the following: elastic notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0218] If message B is based on the second service B, optionally, the UDM can first subscribe to elastic notification events from the NEF. For example, the UDM can send a first subscription request to the NEF, such as called first subscription request B. First subscription request B can be used to request subscription to elastic notification events. If the NEF receives first subscription request B, it can send message B to the UDM upon receiving the first request or upon determining that the first service has failed. Optionally, message B can be regarded as a notification request for the events subscribed to by first subscription request B.

[0219] S604. After receiving message B, the UDM sends message C to the AMF. Correspondingly, the AMF receives message C. Message C can be used to trigger the AMF to send a flexible notification to the called UE. Optionally, message C is message B, or it can be a message generated by the UDM based on message B. For example, message C may include the entire content of message B; or, message C may include a portion of the content of message B, which may include one or more of the following: flexible notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these information items, please refer to [link to relevant documentation]. Figure 4 S403 of the illustrated embodiment.

[0220] Upon receiving message B, the UDM can determine the Instance ID of the AMF instance serving the called UE based on locally stored information. By querying the NRF or according to local configuration, it can determine the address information corresponding to this Instance ID. This address information is the address information of the AMF instance serving the called UE. The UDM can then send message C to this address information.

[0221] Message C can be a message based on a first service, which can be a service provided by the AMF. For distinction, the first service provided by the AMF in this embodiment is referred to as the first service D. For example, the first service D is a service specifically used to trigger resilient notifications, such as Namf_StartResilientNotification. Message C may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0222] Alternatively, the first service D can be a service provided by the AMF, but it is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. For example, the first service D could be Namf_MT, or it could be another service provided by the AMF. Message C may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0223] Alternatively, message C can be a message based on a second service, which can be a service provided by the UDM. For distinction, the second service provided by the UDM in this embodiment is referred to as second service C. For example, second service C is a service specifically for triggering resilient notifications, and second service C is, for example, Nudm_ResilientNotificationStart, and message C is, for example, Nudm_ResilientNotificationStart_Notify. Message C may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0224] Alternatively, the second service C can be a service provided by UDM, but it is not a service specifically designed to trigger elastic notifications; rather, it reuses an existing service. For example, the second service C could be Nudm_EventExposure, and the message C could be, for example, Nudm_EventExposure_notify, or it could be another service provided by NEF. The message C may include one or more of the following: elastic notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0225] If message C is based on the second service C, optionally, the AMF can first subscribe to elastic notification events from the UDM. For example, the AMF can send a first subscription request to the UDM, such as called the first subscription request C. The first subscription request C can be used to request subscription to elastic notification events. If the UDM receives the first subscription request C, it can send message C to the AMF upon receiving message B or upon determining that the first service has failed. Optionally, message C can be regarded as a notification request for the events subscribed to by the first subscription request C.

[0226] S602~S604 and Figure 4 S403 in the illustrated embodiment can be the same step; for more details, please refer to the relevant description of S403.

[0227] S605. After receiving message C, the AMF sends a flexible notification to the access network device. Correspondingly, the access network device receives this flexible notification. This access network device can be the access network device serving the called UE.

[0228] S606. After receiving the elastic notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0229] Among them, S605 and Figure 4 In the illustrated embodiment, S404 can be the same step, and S606 is the same as... Figure 4S405 in the illustrated embodiment can be the same step, so for more details, please refer to the relevant descriptions of S404 and S405.

[0230] After S607 and AMF send the elastic notification, they send response message 3 to UDM. UDM then receives this response message 3.

[0231] Response message 3 can indicate whether the elastic notification was sent successfully or failed. Response message 3 can be considered a response to message C.

[0232] After receiving response message 3, S608 and UDM send response message 4 to NEF. NEF then receives response message 4.

[0233] Response message 4 can indicate whether the elastic notification was sent successfully or failed. The content indicated by response message 4 can be the same as that indicated by response message 3. Response message 4 can be considered a response to message B.

[0234] After receiving response message 4, S609 and NEF send response message 5 to AF. Correspondingly, AF receives response message 5.

[0235] Response message 5 can indicate whether the elastic notification was sent successfully or failed. The content indicated by response message 5 can be the same as that indicated by response message 4. Response message 5 can be considered a response to the first message.

[0236] In this embodiment, the AMF can send a flexible notification to the called UE, and this flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, making the notification method more flexible. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. For example, the called UE can output this information, allowing the called user to determine whether to execute the first service. It is evident that this flexible notification can provide more basis for the called user's judgment, making the notification method more effective. For example, if the called user believes that the first service does not need to be executed, the called user can avoid responding, such as avoiding satellite alignment of the called UE, thereby reducing the power consumption of the called UE and reducing interference to the called user. Optionally, whether the NEF message reaches the AMF directly or through the UDM can depend on the protocol specifications or the implementation of the network element. Furthermore, in this embodiment, the AF can trigger the AMF to send an elastic notification only after determining that the first service has failed. This can both remind the called user and reduce interference to the called user. Alternatively, the AF can trigger the AMF to send an elastic notification after receiving the first request, without having to determine whether the first service has succeeded or failed. This implementation can improve the sending efficiency of the elastic notification, so that the called UE can know that the first service has arrived as soon as possible.

[0237] This application provides a fourth communication method, please refer to the embodiments. Figure 7 The following is a flowchart of the method. In this method, the first network element is an IMS AS or S-CSCF within the called network, and the second network element is an AMF within the called network, as an example. In the following description, we will use an IMS AS as the first network element; if the first network element is an S-CSCF, then "IMSAS" in this embodiment can be replaced with "S-CSCF".

[0238] S701, the IMS AS receives a first request from the calling UE. The first request can be used to request a first service. In this embodiment, the first service is, for example, a call service or a voice call service.

[0239] Among them, S701 and Figure 4 S401 in the illustrated embodiment can be the same step; for more details, please refer to the corresponding description of S401.

[0240] After receiving the first request, the IMS AS sends a first message to the UDM. Correspondingly, the UDM receives the first message. This UDM is the UDM serving the called UE within the called network.

[0241] The first message can be used to trigger the UDM to send a flexible notification to the called UE. In this embodiment, the IMS AS and AMF cannot communicate directly. The UDM can act as an intermediate network element between the IMS AS and AMF, so the first message of the IMS AS can be sent to the UDM.

[0242] This embodiment of the application takes the example of the IMS AS sending the first message immediately after receiving the first request, that is, the IMS AS sends the first message without determining whether the first service has failed. Alternatively, the IMS AS may send the first message only after determining that the first service has failed. For example, after receiving the first request, the IMS AS can send the first request to the called UE (this step is the same as...). Figure 4 In the illustrated embodiment, S402 can be the same step. Based on the sent first request, the IMS AS can determine whether the first service succeeded or failed. If the first service failed, the IMS AS can execute S702, which can be replaced by the IMS AS sending a first message to the UDM after determining that the first service failed. Correspondingly, the UDM receives the first message. This S702 is consistent with... Figure 4 In the illustrated embodiment, S403 can be the same step. For details regarding the IMS AS sending the first request to the called UE and the IMS AS determining whether the first service has failed, please refer to [link / reference needed]. Figure 4 S402 and S403 of the illustrated embodiment.

[0243] The first message can be a message based on a first service, which can be a service provided by the UDM. For distinction, the first service provided by the UDM in this embodiment is referred to as the first service E. For example, the first service E is a service specifically used to trigger resilient notifications, such as Nudm_StartResilientNotification. The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0244] Alternatively, the first service E can be a service provided by the UDM, but it is not a service specifically designed to trigger elastic notifications; rather, it reuses an existing service. Optionally, in 5GC, the UDM and HSS can be co-located in the same network element, in which case the services provided by the UDM can also include those provided by the HSS. For example, the first service E could be the IMS user data management service (Nhss_ImsSubscriberDataManagement, Nhss_ImsSDM) provided by the HSS, or it could be other services provided by the UDM. The first message may include one or more of the following: elastic notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0245] Alternatively, the first message can be based on a second service, which can be a service provided by the IMS AS. For distinction, the second service provided by the IMS AS in this embodiment is referred to as the second service D. For example, the second service D is a service specifically for triggering resilient notifications, such as Nimsas_ResilientNotificationStart, and the first message is such as Nimsas_ResilientNotificationStart_Notify. The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0246] Alternatively, the second service D can be a service provided by the IMS AS, but it is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. For example, the second service D could be the session event control service (Nimsas_SessionEventControl) provided by the IMS AS, and the first message could be, for example, Nimsas_SessionEventControl_Notify. The first message could include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0247] If the first message is based on the second service D, optionally, the UDM can first subscribe to elastic notification events from the IMS AS. For example, the UDM can send a first subscription request to the IMS AS, such as called the first subscription request D. The first subscription request D can be used to request subscription to elastic notification events. If the IMS AS receives the first subscription request D, it can send a first message to the UDM upon receiving the first request or upon determining that the first service has failed. Optionally, the first message can be regarded as a notification request for the events subscribed to by the first subscription request D.

[0248] S703. After receiving the first message, the UDM sends message D to the AMF. Correspondingly, the AMF receives message D. This AMF is the AMF within the called network. Message D can be used to trigger the AMF to send a resilient notification to the called UE. Optionally, message D is the first message, or it can be a message generated by the UDM based on the first message. For example, message D may include the entire content of the first message; or, message D may include a portion of the first message, which may include one or more of the following: resilient notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these items, please refer to [link to relevant documentation]. Figure 4 S403 of the illustrated embodiment.

[0249] Upon receiving the first message, the UDM can determine the Instance ID of the AMF instance serving the called UE based on locally stored information. By querying the NRF or using local configuration, the address information corresponding to this Instance ID can be determined; this address information is the address information of the AMF instance serving the called UE. The UDM can then send message D to this address information.

[0250] Message D can be a message based on a first service, which can be a service provided by the AMF. For distinction, the first service provided by the AMF in this embodiment is referred to as the first service F. For example, the first service F is a service specifically used to trigger resilient notifications, such as Namf_StartResilientNotification. Message D may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0251] Alternatively, the first service F can be a service provided by the AMF, but it is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. For example, the first service F could be Namf_MT, or it could be another service provided by the AMF. Message D may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0252] Alternatively, message D can be a message based on a second service, which can be a service provided by the UDM. For distinction, the second service provided by the UDM in this embodiment is referred to as second service E. For example, second service E is a service specifically for triggering resilient notifications, such as Nhss_ResilietNotificationStart, and message D is such as Nudm_ResilietNotificationStart_Notify. Message D may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0253] Alternatively, the second service E can be a service provided by the UDM, but it is not a service specifically designed to trigger elastic notifications; rather, it reuses an existing service. For example, the second service E could be Nhss_ImsSubscriberDataManagement, and message D could be Nhss_ImsSubscriberDataManagement_Notify. Message D may include one or more of the following: elastic notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0254] If message D is based on the second service E, optionally, the AMF can first subscribe to elastic notification events from the UDM. For example, the AMF can send a first subscription request to the UDM, such as called the first subscription request E. The first subscription request E can be used to request subscription to elastic notification events. If the UDM receives the first subscription request E, it can send message D to the AMF upon receiving the first request or upon determining that the first service has failed. Optionally, message D can be regarded as a notification request for the events subscribed to by the first subscription request E.

[0255] S702~S703 and Figure 4 S403 in the illustrated embodiment can be the same step; for more details, please refer to the relevant description of S403.

[0256] S704. After receiving message D, the AMF sends a flexible notification to the access network device. Correspondingly, the access network device receives this flexible notification. This access network device can be the access network device serving the called UE.

[0257] S705. After receiving the flexible notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0258] Among them, S704 and Figure 4 In the illustrated embodiment, S404 can be the same step, and S705 is the same as... Figure 4 S405 in the illustrated embodiment can be the same step, so for more details, please refer to the relevant descriptions of S404 and S405.

[0259] After S706 and AMF send the elastic notification, they send response message 6 to UDM. UDM then receives this response message 6.

[0260] Response message 6 can indicate whether the elastic notification was sent successfully or failed. Response message 6 can be considered a response to message D.

[0261] After receiving response message 6, S707 and UDM send response message 7 to IMS AS. Correspondingly, IMS AS receives response message 7.

[0262] Response message 7 can indicate whether the elastic notification was sent successfully or failed. The content indicated by response message 7 can be the same as that indicated by response message 6. Response message 7 can be considered a response to the first message.

[0263] In this embodiment, the AMF can send a flexible notification to the called UE, and this flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, making the notification method more flexible. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. For example, the called UE can output this information, allowing the called user to determine whether to execute the first service. It is evident that this flexible notification can provide more basis for the called user's judgment, making the notification method more effective. For example, if the called user believes that the first service does not need to be executed, the called user can avoid responding, such as avoiding satellite alignment of the called UE, thereby reducing the power consumption of the called UE and minimizing interference to the called user. Furthermore, in this embodiment, the IMS AS can trigger the AMF to send a flexible notification only after determining that the first service has failed. This can both remind the called user and reduce interference to the called user. Alternatively, the IMS AS can trigger the AMF to send a flexible notification after receiving the first request, without having to determine whether the first service has succeeded or failed. This implementation can improve the sending efficiency of the flexible notification, so that the called UE can know that the first service has arrived as soon as possible.

[0264] This application provides a fifth communication method; please refer to [link / reference]. Figure 8 The following is a flowchart of the method. In this method, the first network element is an IMS AS or S-CSCF within the called network, and the second network element is an MME within the called network, as an example. In the following description, we will use an IMS AS as the first network element; if the first network element is an S-CSCF, then "IMSAS" in this embodiment can be replaced with "S-CSCF".

[0265] S801, the IMS AS receives a first request from the calling UE. The first request can be used to request a first service. In this embodiment, the first service is, for example, a call service or a voice call service.

[0266] Among them, S801 and Figure 4 S401 in the illustrated embodiment can be the same step; for more details, please refer to the corresponding description of S401.

[0267] After receiving the first request, the S802 IMS AS sends a first message to the HSS. Correspondingly, the HSS receives the first message. This HSS is the HSS within the called network.

[0268] The first message can be used to trigger the UDM to send a flexible notification to the called UE. In this embodiment, the IMS AS and MME cannot communicate directly, and the HSS can act as an intermediate network element between the IMS AS and MME. Therefore, the first message of the IMS AS can be sent to the HSS.

[0269] This embodiment of the application takes the example of the IMS AS sending the first message immediately after receiving the first request, that is, the IMS AS sends the first message without determining whether the first service has failed. Alternatively, the IMS AS may send the first message only after determining that the first service has failed. For example, after receiving the first request, the IMS AS can send the first request to the called UE (this step is the same as...). Figure 4 In the illustrated embodiment, S402 can be the same step. Based on the sent first request, the IMS AS can determine whether the first service succeeded or failed. If the first service failed, the IMS AS can execute S802, which can be replaced by the IMS AS sending a first message to the HSS after determining that the first service failed. Correspondingly, the HSS receives the first message. This S802 is consistent with... Figure 4 In the illustrated embodiment, S403 can be the same step. For details regarding the IMS AS sending the first request to the called UE and the IMS AS determining whether the first service has failed, please refer to [link / reference needed]. Figure 4 S402 and S403 of the illustrated embodiment.

[0270] The first message can be a message based on a first interface, which can be the communication interface between the IMS AS and the HSS, for example, referred to as first interface A. First interface A is, for example, the Sh interface. For example, the first message is a message specifically used to trigger resilient notification, such as a Start-Resilient-Notification-Request (SRR). The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0271] Alternatively, the first message may not be an interface specifically designed to trigger resilient notifications, but rather a reused message from the IMS AS and HSS. In this case, the first message could be, for example, a User-Data-Request (UDR) message, or it could be another message based on the first interface A. The first message may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0272] S803. After receiving the first message, the HSS sends message E to the MME. Correspondingly, the MME receives message E. This MME is the MME serving the called UE within the called network. Message E can be used to trigger the MME to send a resilient notification to the called UE. Optionally, message E is the first message, or it can be a message generated by the HSS based on the first message. For example, message E may include the entire content of the first message; or, message E may include a portion of the first message, which may include one or more of the following: resilient notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these items, please refer to [link to relevant documentation]. Figure 4 S403 of the illustrated embodiment.

[0273] Message E can be a message based on a first interface, which can be the communication interface between the HSS and MME, for example, referred to as first interface B. First interface B is, for example, the S6a interface. Message E is specifically designed to trigger flexible notifications; message E is, for example, an SRR. Message E may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0274] Alternatively, message E may not be a dedicated interface for triggering resilient notifications, but rather a reused message from the HSS and MME. In this case, message E could be, for example, an Insert-Subscriber-Data-Request (IDR) message, or it could be another message based on the first interface B. Message E may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0275] S802~S803 and Figure 4 S403 in the illustrated embodiment can be the same step; for more details, please refer to the relevant description of S403.

[0276] S804: After receiving message E, the MME sends a flexible notification to the access network device. Correspondingly, the access network device receives this flexible notification. This access network device can be the access network device serving the called UE.

[0277] S805. After receiving the flexible notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0278] Among them, S804 and Figure 4 In the illustrated embodiment, S404 can be the same step, and S805 is the same as... Figure 4 S405 in the illustrated embodiment can be the same step, so for more details, please refer to the relevant descriptions of S404 and S405.

[0279] After S806 and MME send the elastic notification, they send response message 8 to HSS. HSS then receives this response message 8.

[0280] The response message 8 can indicate whether the elastic notification was sent successfully or failed. This response message 8 can be considered a response to message E.

[0281] After receiving response message 8, S807 and HSS send response message 9 to IMS AS. Correspondingly, IMS AS receives response message 9.

[0282] Response message 9 can indicate whether the elastic notification was sent successfully or failed. The content indicated by response message 9 can be the same as that indicated by response message 8. Response message 9 can be considered a response to the first message.

[0283] In this embodiment, the MME can send a flexible notification to the called UE, and this flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, making the notification method more flexible. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. For example, the called UE can output this information, allowing the called user to determine whether to execute the first service. It is evident that this flexible notification can provide more basis for the called user's judgment, making the notification method more effective. For example, if the called user believes that the first service does not need to be executed, the called user can avoid responding, such as avoiding satellite alignment, thereby reducing the power consumption of the called UE and minimizing interference to the user. Furthermore, in this embodiment, the IMS AS can trigger the MME to send an elastic notification only after determining that the first service has failed. This can both remind the called user and reduce interference to the called user. Alternatively, the IMS AS can trigger the MME to send an elastic notification after receiving the first request, without having to determine whether the first service has succeeded or failed. This implementation can improve the sending efficiency of the elastic notification, so that the called UE can know that the first service has arrived as soon as possible.

[0284] This application provides a sixth communication method; please refer to [link / reference]. Figure 9 The flowchart below illustrates the method. In this method, an example is taken where the first network element is the P-CSCF within the called network and the second network element is the AMF within the called network.

[0285] S901, the P-CSCF receives a first request from the calling UE. The first request can be used to request a first service. In this embodiment, the first service is, for example, a voice call service or a call-to-call service.

[0286] Among them, S901 and Figure 4 S401 in the illustrated embodiment can be the same step; for more details, please refer to the corresponding description of S401.

[0287] After receiving the first request, S902 and P-CSCF send the first message to the PCF. The PCF then receives the first message. This PCF is located within the called network.

[0288] The first message can be used to trigger the PCF to send a flexible notification to the called UE. In this embodiment, the P-CSCF and AMF cannot communicate directly. The PCF can act as an intermediate network element between the P-CSCF and AMF, so the first message of the P-CSCF can be sent to the PCF.

[0289] This embodiment of the application takes the example of the P-CSCF sending the first message immediately after receiving the first request, that is, the P-CSCF sends the first message without determining whether the first service has failed. Alternatively, the P-CSCF may send the first message only after determining that the first service has failed. For example, after receiving the first request, the P-CSCF can send the first request to the called UE (this step is the same as...). Figure 4 In the illustrated embodiment, S402 can be the same step. Based on the sent first request, the P-CSCF can determine whether the first service succeeded or failed. If the first service failed, the P-CSCF can execute S902, which can be replaced by the following: after determining that the first service failed, the P-CSCF sends a first message to the PCF, and the PCF receives the first message. This S902 is consistent with... Figure 4 In the illustrated embodiment, S403 can be the same step. For details regarding the P-CSCF sending the first request to the called UE and the P-CSCF determining whether the first service has failed, please refer to [link / reference needed]. Figure 4 S402 and S403 of the illustrated embodiment.

[0290] For example, the P-CSCF can query the binding support function (BSF) based on the information of the called UE (such as the GPSI or SUPI identifier of the called UE), determine the PCF instance serving the called UE, and then send the first message to that PCF instance.

[0291] The first message can be a message based on a first service, which can be a service provided by the PCF. For distinction, the first service provided by the PCF in this embodiment is referred to as the first service G. For example, the first service G is a service specifically used to trigger resilient notifications, and the name of the first service G is, for example, Npcf_StartResilientNotification. The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0292] Alternatively, the first service G can be a service provided by the PCF, but it is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. For example, the first service G could be the policy authorization service (Npcf_PolicyAuthorization) provided by the PCF, or it could be another service provided by the PCF. The first message may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0293] Alternatively, the first message can be a message based on a second service, which can be a service provided by the P-CSCF. For distinction, the second service provided by the P-CSCF in this embodiment is referred to as the second service F. For example, the second service F can be a service specifically for triggering resilient notifications, or the second service F can have other functions. The second service F is, for example, Np-cscf_ResilientNotificationStart, and the first message is, for example, Np-cscf_ResilientNotificationStart_Notify. The first message may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0294] If the first message is based on the second service F, optionally, the PCF can first subscribe to elastic notification events from the P-CSCF. For example, the PCF can send a first subscription request to the P-CSCF, such as called the first subscription request F. The first subscription request F can be used to request subscription to elastic notification events. If the P-CSCF receives the first subscription request F, it can send a first message to the PCF upon receiving the first request or upon determining that the first service has failed. Optionally, the first message can be regarded as a notification request for the events subscribed to by the first subscription request F.

[0295] S903. After receiving the first message, the PCF sends message F to the SMF. Correspondingly, the SMF receives message F. This SMF is an SMF within the called network. Message F can be used to trigger the SMF to send a flexible notification to the called UE. Optionally, message F is the first message, or it can be a message generated by the PCF based on the first message. For example, message F may include the entire content of the first message; or, message F may include a portion of the first message, which may include one or more of the following: flexible notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these items, please refer to [reference needed]. Figure 4 S403 of the illustrated embodiment.

[0296] In this embodiment, the P-CSCF and AMF cannot communicate directly. The PCF and SMF can act as intermediate network elements between the P-CSCF and AMF. Therefore, the first message from the P-CSCF can be sent to the PCF, and the PCF's message F can be sent to the SMF. For example, after receiving the first message, the PCF can send message F to the SMF serving the called UE.

[0297] Message F can be a message based on a first service, which can be a service provided by the SMF. For distinction, the first service provided by the SMF in this embodiment is referred to as the first service H. For example, the first service H is a service specifically used to trigger resilient notifications, such as Nsmf_StartResilientNotification. The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0298] Alternatively, the first service H can be a service provided by the SMF, but it is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. For example, the first service H could be a Protocol Data Unit (PDU) session service (Nsmf_PDUSession) provided by the SMF, and message F could be an update request message for the PDU session service provided by the SMF (Nsmf_PDUSession_Update), or it could be another service provided by the SMF. Message F may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0299] Alternatively, message F can be a message based on a second service, which can be a service provided by the PCF. For distinction, the second service provided by the PCF in this embodiment is referred to as second service G. For example, second service G can be a service specifically for triggering resilient notifications, or second service G can have other functions. Second service G is, for example, Npcf_ResilientNotificationStart, and message F is, for example, Npcf_ResilientNotificationStart_Notify. Message F may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0300] Alternatively, message F can be based on a second service G, but the second service G is not a service specifically designed to trigger flexible notifications; rather, it reuses an existing service. The second service G could be, for example, the session management policy control service (Npcf_SMPolicyControl) provided by the PCF, and message F could be, for example, an update notification request message for the session management policy control service (Npcf_SMPolicyControl_UpdateNotify) provided by the PCF, or it could be other services provided by the PCF. Message F may include one or more of the following: flexible notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0301] If message F is based on the second service G, optionally, the PCF can first subscribe to elastic notification events from the P-CSCF. For example, the SMF can send a first subscription request to the PCF, such as called the first subscription request G. The first subscription request G can be used to request subscription to elastic notification events. If the PCF receives the first subscription request G, it can send message F to the SMF upon receiving the first request or upon determining that the first service has failed. Optionally, the first message can be regarded as a notification request for the events subscribed to by the first subscription request G.

[0302] S904. After receiving message F, the SMF sends message G to the AMF. Correspondingly, the AMF receives message G. This AMF is the AMF within the called network. Message G can be used to trigger the AMF to send a resilient notification to the called UE. Optionally, message G is message F, or it can be a message generated by the SMF based on message F. For example, message G may include the entire content of message F; or, message G may include a portion of the content of message F, which may include one or more of the following: resilient notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these items, please refer to [reference needed]. Figure 4 S403 of the illustrated embodiment.

[0303] In this embodiment, the P-CSCF and AMF cannot communicate directly. The PCF and SMF can act as intermediate network elements between the P-CSCF and AMF. The first message from the P-CSCF can be sent to the PCF, message F from the PCF can be sent to the SMF, and message G from the SMF can be sent to the AMF. For example, if the SMF receives message F, it can send message G to the AMF serving the called UE.

[0304] Here, message G can be a message based on a first service, which can be a service provided by the AMF. For distinction, the first service provided by the AMF in this embodiment is referred to as first service I. For example, first service I is a service specifically used to trigger resilient notifications, and the name of first service I is, for example, Namf_StartResilientNotification. The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0305] Alternatively, the first service I can be a service provided by the AMF, but it is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. For example, the first service I could be Namf_MT, or it could be another service provided by the AMF. Message G may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0306] Alternatively, message G can be a message based on a second service, which can be a service provided by the SMF. For distinction, the second service provided by the SMF in this embodiment is referred to as second service H. For example, second service H can be a service specifically for triggering resilient notifications, or second service H can have other functions. Second service H is, for example, Nsmf_ResilientNotificationStart, and message G is, for example, Nsmf_ResilientNotificationStart_Notify. Message G may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0307] Alternatively, message G can be based on a second service H, but the second service H is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. The second service H could be, for example, Nsmf_PDUSession, or other services provided by SMF. Message H may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0308] If message G is based on the second service H, optionally, the AMF can first subscribe to elastic notification events from the SMF. For example, the AMF can send a first subscription request to the SMF, such as called the first subscription request H. The first subscription request H can be used to request subscription to elastic notification events. If the SMF receives the first subscription request H, it can send message G to the AMF upon receiving message F or upon determining that the first service has failed. Optionally, message G can be regarded as a notification request for the events subscribed to by the first subscription request H.

[0309] S902~S904 and Figure 4 S403 in the illustrated embodiment can be the same step; for more details, please refer to the relevant description of S403.

[0310] After receiving message G, S905 and AMF send a flexible notification to the access network device. The access network device then receives this flexible notification. This access network device can be the access network device serving the called UE.

[0311] S906. After receiving the flexible notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0312] Among them, S905 and Figure 4 In the illustrated embodiment, S404 can be the same step, and S906 is the same as... Figure 4 S405 in the illustrated embodiment can be the same step, so for more details, please refer to the relevant descriptions of S404 and S405.

[0313] After S907 and AMF send the elastic notification, they send response message 10 to SMF. SMF then receives the response message 10.

[0314] The response message 10 can indicate whether the sending of the elastic notification was successful or failed. Here, the response message 10 can be considered a response to message G.

[0315] After receiving response message 10, S908 and SMF send response message 11 to PCF. Correspondingly, PCF receives response message 11.

[0316] The response message 11 can indicate whether the elastic notification was sent successfully or failed, and the content indicated by the response message 11 can be the same as the content indicated by the response message 10. The response message 11 can be regarded as a response to message F.

[0317] After receiving response message 11, S909 and PCF send response message 12 to P-CSCF. Correspondingly, P-CSCF receives response message 12.

[0318] The response message 12 can indicate whether the sending of the elastic notification was successful or failed, and the content indicated by the response message 12 can be the same as the content indicated by the response message 11. The response message 12 can be regarded as a response to the first message.

[0319] In this embodiment, the AMF can send a flexible notification to the called UE, and this flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, making the notification method more flexible. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. For example, the called UE can output this information, allowing the called user to determine whether to execute the first service. It is evident that this flexible notification can provide more basis for the called user's judgment, making the notification method more effective. For example, if the called user believes that the first service does not need to be executed, the called user can avoid responding, such as avoiding satellite alignment with the called UE, thereby reducing the power consumption of the called UE and minimizing interference to the called user. Furthermore, in this embodiment, the P-CSCF can trigger the AMF to send an elastic notification only after determining that the first service has failed. This can both remind the called user and reduce interference to the called user. Alternatively, the P-CSCF can trigger the AMF to send an elastic notification after receiving the first request, without having to determine whether the first service has succeeded or failed. This implementation can improve the sending efficiency of the elastic notification, so that the called UE can know that the first service has arrived as soon as possible.

[0320] This application provides a seventh communication method, please refer to the embodiments. Figure 10 The flowchart below illustrates the method. In this method, an example is taken where the first network element is the P-CSCF within the called network and the second network element is the MME within the called network.

[0321] S1001, the P-CSCF receives a first request from the calling UE. The first request can be used to request a first service. In this embodiment, the first service is, for example, a voice call service or a call-to-call service.

[0322] Among them, S1001 and Figure 4 S401 in the illustrated embodiment can be the same step; for more details, please refer to the corresponding description of S401.

[0323] After receiving the first request, S1002 and P-CSCF send the first message to the PCRF. Correspondingly, the PCRF receives the first message. This PCRF is the PCRF within the called network.

[0324] The first message can be used to trigger the PCRF to send a resilient notification to the called UE. In this embodiment, the P-CSCF and MME cannot communicate directly. The PCRF can act as an intermediary network element between the P-CSCF and the MME, so the first message of the P-CSCF can be sent to the PCRF.

[0325] This embodiment of the application takes the example of the P-CSCF sending the first message immediately after receiving the first request, that is, the P-CSCF sends the first message without determining whether the first service has failed. Alternatively, the P-CSCF may send the first message only after determining that the first service has failed. For example, after receiving the first request, the P-CSCF can send the first request to the called UE (this step is the same as...). Figure 4 In the illustrated embodiment, S402 can be the same step. Based on the sent first request, the P-CSCF can determine whether the first service succeeded or failed. If the first service failed, the P-CSCF can execute S1002, which can be replaced by the following: after determining that the first service failed, the P-CSCF sends a first message to the PCRF, and the PCRF receives the first message. This S1002 is consistent with... Figure 4 In the illustrated embodiment, S403 can be the same step. For details regarding the P-CSCF sending the first request to the called UE and the P-CSCF determining whether the first service has failed, please refer to [link / reference needed]. Figure 4 S402 and S403 of the illustrated embodiment.

[0326] The first message can be a message based on a first interface, which can be the communication interface between the P-CSCF and the PCRF, for example, referred to as the first interface C. The first interface C is, for example, the Rx interface. For example, the first message can be a message specifically used to trigger a resilient notification, such as an SRR. The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0327] Alternatively, the first message may not be specifically designed to trigger the resilient notification, but may reuse an existing message between the P-CSCF and PCRF. For example, the first message could be an Authentication-Authorization-Request (AAR), or it could be another message based on the first interface C. The first message may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0328] S1003. After receiving the first message, the PCRF sends message H to the PGW. Correspondingly, the PGW receives message H. This PGW is the PGW within the called network. Message H can be used to trigger the PGW to send a resilient notification to the called UE. Optionally, message H is the first message, or it can be a message generated by the PCRF based on the first message. For example, message H may include the entire content of the first message; or, message H may include a portion of the first message, which may include one or more of the following: resilient notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these items, please refer to [link to relevant documentation]. Figure 4 S403 of the illustrated embodiment.

[0329] In this embodiment, the P-CSCF and MME cannot communicate directly. The PCRF and PGW can act as intermediate network elements between the P-CSCF and MME. Therefore, the first message from the P-CSCF can be sent to the PCRF, and the PCRF's message H can be sent to the PGW. For example, after receiving the first message, the PCRF can send message H to the PGW serving the called UE.

[0330] Here, message H can be a message based on a first interface, which can be the communication interface between the PCRF and the PGW, for example, referred to as the first interface D. The first interface D is, for example, the Gx interface. For example, message H is a message specifically used to trigger elastic notifications, message H is, for example, SRR. Message H may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or, information about the first service.

[0331] Alternatively, message H may not be specifically designed to trigger resilient notifications, but may reuse existing messages between the PCRF and PGW. For example, message H could be a Re-Authentication-Authorization-Request (RAR), or it could be another message based on the first interface D. Message H may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0332] S1004. After receiving message H, the PGW sends message I to the SGW. Correspondingly, the SGW receives message I. This SGW is within the called network. Message I can be used to trigger the SGW to send a resilient notification to the called UE. Optionally, message I is message H, or it can be a message generated by the PGW based on message H. For example, message I may include the entire content of message H; or, message I may include a portion of the content of message H, which may include one or more of the following: resilient notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these items, please refer to [link to relevant documentation]. Figure 4 S403 of the illustrated embodiment.

[0333] In this embodiment, the P-CSCF and MME cannot communicate directly. The PCRF, PGW, and SGW can act as intermediate network elements between the P-CSCF and MME. Therefore, the first message from the P-CSCF can be sent to the PCRF, message H from the PCRF can be sent to the PGW, and message I from the PGW can be sent to the SGW. For example, if the PGW receives message H, it can send message I to the SGW serving the called UE.

[0334] Message I can be a message based on a first interface, which can be the communication interface between the PGW and the SGW, for example, referred to as the first interface E. The first interface E is, for example, an S5 / S8 interface. Message I can also be a message specifically designed to trigger resilient notifications, such as a Start Resilient Notification Request. Message I may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0335] Alternatively, message I may not be specifically designed to trigger resilient notifications, but may reuse existing messages between the PGW and SGW. In this case, message I could be, for example, a Create Bearer Request, or it could be another message based on the first interface E. Message I may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0336] After receiving message I, S1005 and SGW send message J to MME. Correspondingly, MME receives message J. This MME is the MME within the called network. Message I can be used to trigger the MME to send a resilient notification to the called UE. Optionally, message J is message I, or it can be a message generated by SGW based on message I. For example, message J may include the entire content of message I; or, message J may include a portion of the content of message I, which may include one or more of the following: resilient notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these information items, please refer to [link to relevant documentation]. Figure 4 S403 of the illustrated embodiment.

[0337] In this embodiment, the P-CSCF and MME cannot communicate directly. The PCRF, PGW, and SGW can act as intermediate network elements between the P-CSCF and MME. The first message from the P-CSCF can be sent to the PCRF, message H from the PCRF can be sent to the PGW, message I from the PGW can be sent to the SGW, and message J from the SGW can be sent to the MME. For example, if the SGW receives message I, it can send message J to the MME serving the called UE.

[0338] Message J can be a message based on a first interface, which can be the communication interface between the SGW and the MME, for example, referred to as the first interface F. The first interface F is, for example, the S11 interface. Message J can also be a message specifically designed to trigger resilient notifications, such as a Start Resilient Notification Request. Message J may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0339] Alternatively, message J may not be specifically designed to trigger resilient notifications, but may reuse existing messages between the SGW and MME. For example, message J could be a Create Bearer Request, or it could be another message based on the first interface F. Message J may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0340] S1002~S1005 and Figure 4 S403 in the illustrated embodiment can be the same step; for more details, please refer to the relevant description of S403.

[0341] S1006. After receiving message J, the MME sends a flexible notification to the access network device. Correspondingly, the access network device receives this flexible notification. This access network device can be the access network device serving the called UE.

[0342] S1007. After receiving the elastic notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0343] Among them, S1006 and Figure 4 In the illustrated embodiment, S404 can be the same step, and S1007 is the same as... Figure 4 S405 in the illustrated embodiment can be the same step, so for more details, please refer to the relevant descriptions of S404 and S405.

[0344] After S1008 and MME send the elastic notification, they send response message 13 to SGW. Correspondingly, SMF receives response message 13.

[0345] The response message 13 can indicate whether the sending of the elastic notification was successful or failed. Here, the response message 13 can be considered a response to message J.

[0346] After receiving response message 13, S1009 and SGW send response message 14 to PGW. Correspondingly, PCF receives response message 14.

[0347] The response message 14 can indicate whether the elastic notification was sent successfully or failed. The content indicated by response message 14 can be the same as the content indicated by response message 13. Response message 14 can be considered a response to message I.

[0348] After receiving response message 14, S1010 and PGW send response message 15 to PCRF. Correspondingly, PCRF receives response message 15.

[0349] The response message 15 can indicate whether the elastic notification was sent successfully or failed. The content indicated by response message 15 can be the same as the content indicated by response message 14. Response message 15 can be considered a response to message H.

[0350] S1011 After receiving response message 15, PCRF sends response message 16 to P-CSCF. Correspondingly, P-CSCF receives response message 16.

[0351] The response message 16 can indicate whether the elastic notification was sent successfully or failed, and the content indicated by the response message 16 can be the same as the content indicated by the response message 15. The response message 16 can be regarded as a response to the first message.

[0352] In this embodiment, the MME can send a flexible notification to the called UE, and this flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, making the notification method more flexible. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. For example, the called UE can output this information, allowing the called user to determine whether to execute the first service. It is evident that this flexible notification can provide more basis for the called user's judgment, making the notification method more effective. For example, if the called user believes that the first service does not need to be executed, the called user can avoid responding, such as avoiding satellite alignment of the called UE, thereby reducing the power consumption of the called UE and minimizing interference to the called user. Furthermore, in this embodiment, the P-CSCF can trigger the MME to send an elastic notification only after determining that the first service has failed. This can both remind the called user and reduce interference to the called user. Alternatively, the P-CSCF can trigger the MME to send an elastic notification after receiving the first request, without having to determine whether the first service has succeeded or failed. This implementation can improve the sending efficiency of the elastic notification, so that the called UE can know that the first service has arrived as soon as possible.

[0353] This application provides an eighth communication method, please refer to the embodiments. Figure 11 The diagram below shows the flowchart of this method. In this method, we take an example where the first network element is the SMS service network element within the called network, and the second network element is the AMF within the called network. This SMS service network element could be, for example, an SMSF or IP-SM-GW.

[0354] S1101, the SMS service network element receives a first request from the calling UE. The first request can be used to request a first service. In this embodiment, the first service is, for example, the SMS service.

[0355] Among them, S1101 and Figure 4 S401 in the illustrated embodiment can be the same step; for more details, please refer to the corresponding description of S401.

[0356] S1102. After receiving the first request, the SMS service network element sends the first message to the UDM. Correspondingly, the UDM receives the first message. This UDM is the UDM within the called network.

[0357] This embodiment of the application takes the example of the SMS service network element sending the first message immediately after receiving the first request; that is, the SMS service network element sends the first message without determining whether the first service has failed. Alternatively, the P-CSCF can also send the first message only after determining that the first service has failed. For example, after receiving the first request, the SMS service network element can send the first request to the called UE (this step is the same as...). Figure 4In the illustrated embodiment, S402 can be the same step. Based on the sent first request, the P-CSCF can determine whether the first service succeeded or failed. If the first service fails, the SMS service network element can execute S1102. In this case, S1102 can be replaced by, after determining that the first service has failed, the SMS service network element sends a first message to the UDM, and correspondingly, the UDM receives the first message. This S1102 is consistent with... Figure 4 In the illustrated embodiment, S403 can be the same step. For details regarding the SMS service network element sending the first request to the called UE and the SMS service network element determining whether the first service has failed, please refer to... Figure 4 S402 and S403 of the illustrated embodiment.

[0358] In this embodiment, the SMS service network element and the AMF may not be able to communicate directly (e.g., the SMS service network element is an IP-SM-GW). The UDM can act as an intermediary network element between the SMS service network element and the AMF, and the first message of the SMS service network element can be sent to the UDM. For example, if the SMS service network element receives a first request, it can send a first message to the UDM serving the called UE. The first message can be used to trigger the UDM to send a flexible notification to the called UE.

[0359] Alternatively, if the SMS service network element and the AMF can communicate directly, the SMS service network element can send the first message to the AMF without going through the UDM. Then, S1102 and S1103 (described later) can be replaced by the SMS service network element sending the first message to the AMF, and the corresponding AMF receiving the first message. The first message can be a service-oriented interface message based on a service provided by the AMF, or a service-oriented interface message based on a service provided by the SMS service network element.

[0360] For example, the SMS service network element determines the address information corresponding to the UDM instance of the called UE by querying the NRF or according to the local configuration, and then sends the first message to that address.

[0361] The first message can be a message based on a first service, which can be a service provided by the UDM. For distinction, the first service provided by the UDM in this embodiment is referred to as the first service J. For example, the first service J is a service specifically used to trigger resilient notifications, such as Nudm_StartResilientNotification. The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0362] Alternatively, the first service J can be a service provided by the UDM, but it is not a service specifically designed to trigger elastic notifications; rather, it reuses an existing service. For example, the first service J could be Nhss_ImsSDM, or it could be another service provided by the UDM. The first message may include one or more of the following: elastic notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0363] Alternatively, the first message can be a message based on a second service, where the second service can be a service provided by an SMS service network element, such as SMSF or IP-SM-GW. For ease of description, this application uses SMSF as an example. To distinguish it, the second service provided by the SMS service network element in this application embodiment is referred to as second service I. For example, second service I can be a service specifically for triggering resilient notifications, or second service I can have other functions. Second service I is, for example, Nsmsf_ResilientNotificationStart, and the first message is, for example, Nsmsf_ResilientNotificationStart_Notify. The first message may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0364] If the first message is based on the second service I, optionally, the UDM can first subscribe to elastic notification events from the SMS service network element. For example, the UDM can send a first subscription request to the SMS service network element, such as referred to as the first subscription request I. The first subscription request I can be used to request subscription to elastic notification events. If the SMS service network element receives the first subscription request I, it can send a first message to the UDM upon receiving the first request or upon determining that the first service has failed. Optionally, the first message can be regarded as a notification request for the events subscribed to by the first subscription request I.

[0365] S1103. After receiving the first message, the UDM sends message K to the AMF. Correspondingly, the AMF receives message K. This AMF is the AMF within the called network. Message K can be used to trigger the AMF to send a resilient notification to the called UE. Optionally, message K is the first message, or it can be a message generated by the UDM based on the first message. For example, message K may include the entire content of the first message; or, message K may include a portion of the first message, which may include one or more of the following: resilient notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these items, please refer to [link to relevant documentation]. Figure 4 S403 of the illustrated embodiment.

[0366] Here, message K can be a message based on a first service, which can be a service provided by the AMF. For distinction, the first service provided by the AMF in this embodiment is referred to as the first service K. For example, the first service K is a service specifically used to trigger resilient notifications, such as Namf_StartResilientNotification. Message K may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0367] Alternatively, the first service K can be a service provided by the AMF, but it is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. For example, the first service K could be Namf_MT, or it could be another service provided by the AMF. Message K may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0368] Alternatively, message K can be a message based on a second service, which can be a service provided by the UDM. For distinction, the second service provided by the UDM in this embodiment is referred to as second service I. For example, second service I can be a service specifically for triggering resilient notifications, or second service I can have other functions. Second service I is, for example, Nudm_ResilientNotificationStart, and message K is, for example, Nudm_ResilientNotificationStart_Notify. Message K may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0369] Alternatively, message K can be based on a second service I, but the second service I is not a service specifically designed to trigger resilient notifications; rather, it reuses an existing service. The second service I is, for example, Nhss_ImsSDM, and message K is, for example, Nhss_ImsSDM_Notify. Message K may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0370] If message K is based on the second service I, optionally, the AMF can first subscribe to elastic notification events from the UDM. For example, the AMF can send a first subscription request to the UDM, such as called the first subscription request J. The first subscription request J can be used to request subscription to elastic notification events. If the UDM receives the first subscription request J, it can send message K to the AMF upon receiving the first request or upon determining that the first service has failed. Optionally, the first message can be regarded as a notification request for the events subscribed to by the first subscription request J.

[0371] S1102~S1103 and Figure 4 S403 in the illustrated embodiment can be the same step; for more details, please refer to the relevant description of S403.

[0372] S1104. After receiving message K, the AMF sends a flexible notification to the access network device. Correspondingly, the access network device receives this flexible notification. This access network device can be the access network device serving the called UE.

[0373] S1105. After receiving the elastic notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0374] Among them, S1104 and Figure 4 In the illustrated embodiment, S404 can be the same step, and S1105 is the same as... Figure 4 S405 in the illustrated embodiment can be the same step, so for more details, please refer to the relevant descriptions of S404 and S405.

[0375] S1106. After the AMF sends the elastic notification, it sends response message 17 to the UDM. Correspondingly, the SMF receives the response message 17.

[0376] The response message 17 can indicate whether the elastic notification was sent successfully or failed. Here, the response message 17 can be considered a response to message K.

[0377] After receiving response message 17, S1107 and UDM send response message 18 to the SMS service network element. Correspondingly, the SMS service network element receives response message 18.

[0378] The response message 18 can indicate whether the elastic notification was sent successfully or failed, and the content indicated by the response message 18 can be the same as the content indicated by the response message 17. The response message 18 can be regarded as a response to the first message.

[0379] In this embodiment, the AMF can send a flexible notification to the called UE, and this flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, making the notification method more flexible. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. For example, the called UE can output this information, allowing the called user to determine whether to execute the first service. It is evident that this flexible notification can provide more basis for the called user's judgment, making the notification method more effective. For example, if the called user believes that the first service does not need to be executed, the called user can avoid responding, such as avoiding having the called UE synchronized with a satellite, thereby reducing the power consumption of the called UE and minimizing interference to the called user. Furthermore, in this embodiment, the SMS service network element can trigger the AMF to send the flexible notification only after determining that the first service has failed, thus both reminding the called user and reducing interference to the called user. Alternatively, the SMS service network element can trigger the AMF to send an elastic notification after receiving the first request, without having to determine whether the first service was successful or failed. This implementation method can improve the sending efficiency of elastic notifications, enabling the called UE to know that the first service has arrived as soon as possible.

[0380] This application provides a ninth communication method, please refer to the embodiments therein. Figure 12 The diagram below shows the flowchart of this method. In this method, we take an example where the first network element is the SMS service network element within the called network, and the second network element is the MME within the called network. This SMS service network element could be, for example, an IP-SM-GW.

[0381] S1201, the SMS service network element receives a first request from the calling UE. The first request can be used to request a first service. In this embodiment, the first service is, for example, the SMS service.

[0382] Among them, S1201 and Figure 4 S401 in the illustrated embodiment can be the same step; for more details, please refer to the corresponding description of S401.

[0383] S1202. After receiving the first request, the SMS service network element sends the first message to the HSS. Correspondingly, the HSS receives the first message. This HSS is the HSS within the called network.

[0384] This embodiment of the application takes the example of the SMS service network element sending the first message immediately after receiving the first request; that is, the SMS service network element sends the first message without determining whether the first service has failed. Alternatively, the P-CSCF can also send the first message only after determining that the first service has failed. For example, after receiving the first request, the SMS service network element can send the first request to the called UE (this step is the same as...). Figure 4In the illustrated embodiment, S402 can be the same step. Based on the sent first request, the P-CSCF can determine whether the first service succeeded or failed. If the first service fails, the SMS service network element can execute S1202. In this case, S1202 can be replaced by, after determining that the first service has failed, the SMS service network element sends a first message to the HSS, and correspondingly, the HSS receives the first message. This S1202 is consistent with... Figure 4 In the illustrated embodiment, S403 can be the same step. For details regarding the SMS service network element sending the first request to the called UE and the SMS service network element determining whether the first service has failed, please refer to... Figure 4 S402 and S403 of the illustrated embodiment.

[0385] In this embodiment, the SMS service network element and the MME cannot communicate directly. The HSS can act as an intermediary network element between the SMS service network element and the MME, so the first message of the SMS service network element can be sent to the HSS. For example, if the SMS service network element receives a first request, it can send a first message to the HSS serving the called UE. The first message can be used to trigger the HSS to send a flexible notification to the called UE.

[0386] For example, the SMS service network element determines the address information corresponding to the UDM instance of the called UE by querying the NRF or according to the local configuration, and then sends the first message to that address.

[0387] The first message can be a message based on a first interface, which can be the communication interface between the SMS service network element and the UDM. For example, the first interface can be referred to as the first interface H. The first interface H is, for example, the Sh interface. For example, the first message is a message specifically used to trigger flexible notifications, and the first message is, for example, SRR. The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0388] Alternatively, the first message may not be specifically designed to trigger the flexible notification, but may reuse an existing message between the SMS service network element and the UDM. For example, the first message could be a UDR, or it could be another message based on the first interface H. The first message may include one or more of the following: flexible notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0389] S1203. After receiving the first message, the HSS sends message L to the MME. Correspondingly, the MME receives message L. This MME is an MME within the called network. Message L can be used to trigger the MME to send a resilient notification to the called UE. Optionally, message L is the first message, or it can be a message generated by the HSS based on the first message. For example, message L may include the entire content of the first message; or, message L may include a portion of the first message, which may include one or more of the following: resilient notification indication information, information indicating the first service, information indicating the calling UE, or information indicating the called UE. For a description of these items, please refer to [reference needed]. Figure 4 S403 of the illustrated embodiment.

[0390] Here, message L can be a message based on a first interface, which can be the communication interface between the HSS and the MME, for example, referred to as first interface I. First interface I is, for example, the S6a interface. For example, message L is a message specifically used to trigger flexible notifications, message L is, for example, SRR. Message L may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or, information of the first service.

[0391] Alternatively, message L may not be specifically designed to trigger resilient notifications, but may reuse existing messages between the HSS and MME. For example, message L could be an IDR, or it could be other messages based on the first interface I. Message L may include one or more of the following: resilient notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0392] S1202~S1203 and Figure 4 S403 in the illustrated embodiment can be the same step; for more details, please refer to the relevant description of S403.

[0393] S1204. After receiving message L, the MME sends a flexible notification to the access network device. Correspondingly, the access network device receives this flexible notification. This access network device can be the access network device serving the called UE.

[0394] S1205. After receiving the elastic notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0395] Among them, S1204 and Figure 4 In the illustrated embodiment, S404 can be the same step, and S1205 is the same as... Figure 4 S405 in the illustrated embodiment can be the same step, so for more details, please refer to the relevant descriptions of S404 and S405.

[0396] S1206. After the MME sends the elasticity notification, it sends response message 19 to the HSS. Correspondingly, the SMF receives the response message 19.

[0397] The response message 19 can indicate whether the elastic notification was sent successfully or failed. Here, the response message 19 can be considered a response to message L.

[0398] After receiving response message 19, S1207 and HSS send response message 20 to the SMS service network element. Correspondingly, the SMS service network element receives response message 20.

[0399] The response message 20 can indicate whether the elastic notification was sent successfully or failed, and the content indicated by the response message 20 can be the same as the content indicated by the response message 19. The response message 20 can be regarded as a response to the first message.

[0400] In this embodiment, the MME can send a flexible notification to the called UE, and this flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, making the notification method more flexible. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. For example, the called UE can output this information, allowing the called user to determine whether to execute the first service. It is evident that this flexible notification can provide more basis for the called user's judgment, making the notification method more effective. For example, if the called user believes that the first service does not need to be executed, the called user can avoid responding, such as avoiding having the called UE synchronized with a satellite, thereby reducing the power consumption of the called UE and minimizing interference to the user. Furthermore, in this embodiment, the SMS service network element can trigger the MME to send the flexible notification only after determining that the first service has failed, thus both reminding the called user and reducing interference to the called user. Alternatively, the SMS service network element can trigger the MME to send an elastic notification after receiving the first request, without having to determine whether the first service was successful or failed. This implementation method can improve the sending efficiency of the elastic notification, so that the called UE can know that the first service has arrived as soon as possible.

[0401] This application provides a tenth communication method; please refer to [the relevant documentation]. Figure 13 The diagram below shows the flowchart of this method. In this method, we take an example where the first network element is the SMS service network element within the called network, and the second network element is the MME within the called network. The SMS service network element is, for example, MSC / VLR.

[0402] S1301, the SMS service network element receives a first request from the calling UE. The first request can be used to request a first service. In this embodiment, the first service is, for example, SMS service. For example, the MSC / VLR can receive a first request from an SMS-GMSC or HSS / HLR.

[0403] Among them, S1301 and Figure 4 S401 in the illustrated embodiment can be the same step; for more details, please refer to the corresponding description of S401.

[0404] S1302. After receiving the first request, the SMS service network element sends the first message to the MME. Correspondingly, the MME receives the first message. This MME is the MME within the called network.

[0405] This embodiment of the application takes the example of the SMS service network element sending the first message immediately after receiving the first request; that is, the SMS service network element sends the first message without determining whether the first service has failed. Alternatively, the P-CSCF can also send the first message only after determining that the first service has failed. For example, after receiving the first request, the SMS service network element can send the first request to the called UE (this step is the same as...). Figure 4 In the illustrated embodiment, S402 can be the same step. Based on the sent first request, the P-CSCF can determine whether the first service succeeded or failed. If the first service fails, the SMS service network element can execute S1302. In this case, S1302 can be replaced by, after determining that the first service has failed, the SMS service network element sends a first message to the MME, and correspondingly, the MME receives the first message. This S1302 is consistent with... Figure 4 In the illustrated embodiment, S403 can be the same step. For details regarding the SMS service network element sending the first request to the called UE and the SMS service network element determining whether the first service has failed, please refer to... Figure 4 S402 and S403 of the illustrated embodiment.

[0406] In this embodiment, the SMS service network element and the MME can communicate directly, thus eliminating the need for an intermediate network element. The first message from the SMS service network element can be sent to the MME. For example, if the SMS service network element receives a first request, it can send a first message to the MME serving the called UE. The first message can be used to trigger the MME to send a flexible notification to the called UE.

[0407] For example, the SMS service network element determines the address information corresponding to the MME instance of the called UE based on its local configuration, and then sends the first message to that address.

[0408] The first message can be a message based on a first interface, which can be the communication interface between the SMS service network element and the MME. For example, the first interface can be referred to as the first interface J. The first interface J is, for example, the SGs interface. For example, the first message is a message specifically used to trigger resilient notifications, such as a resilient notification request. The first message may include one or more of the following: the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0409] Alternatively, the first message may not be specifically designed to trigger the flexible notification, but may reuse an existing message between the SMS service network element and the MME. For example, the first message could be a paging request, or it could be another message based on the first interface J. The first message may include one or more of the following: flexible notification indication information, the identifier of the calling UE, the identifier of the called UE, or information about the first service.

[0410] S1302 and Figure 4 S403 in the illustrated embodiment can be the same step; for more details, please refer to the relevant description of S403.

[0411] S1303 After receiving the first message, the MME sends a flexible notification to the access network device. Correspondingly, the access network device receives this flexible notification. This access network device can be the access network device serving the called UE.

[0412] S1304. After receiving the elastic notification, the access network device sends a third message. Correspondingly, the called UE receives the third message.

[0413] Among them, S1303 and Figure 4 In the illustrated embodiment, S404 can be the same step, and S1304 is the same as... Figure 4 S405 in the illustrated embodiment can be the same step, so for more details, please refer to the relevant descriptions of S404 and S405.

[0414] After S1305 and MME send the elastic notification, they send response message 21 to the SMS service network element. Correspondingly, the SMS service network element receives this response message 21.

[0415] The response message 21 can indicate whether the sending of the elastic notification was successful or failed. This response message 21 can be considered a response to the first message.

[0416] In this embodiment, the MME can send a flexible notification to the called UE, and this flexible notification can indicate information about the first service and / or information about the calling UE corresponding to the first service, making the notification method more flexible. The third message received by the called UE can indicate information about the first service and / or information about the calling UE corresponding to the first service. For example, the called UE can output this information, allowing the called user to determine whether to execute the first service. It is evident that this flexible notification can provide more basis for the called user's judgment, making the notification method more effective. For example, if the called user believes that the first service does not need to be executed, the called user can avoid responding, such as avoiding having the called UE synchronized with a satellite, thereby reducing the power consumption of the called UE and minimizing interference to the called user. Furthermore, in this embodiment, the SMS service network element can trigger the MME to send the flexible notification only after determining that the first service has failed, thus both reminding the called user and reducing interference to the called user. Alternatively, the SMS service network element can trigger the MME to send an elastic notification after receiving the first request, without having to determine whether the first service was successful or failed. This implementation method can improve the sending efficiency of the elastic notification, so that the called UE can know that the first service has arrived as soon as possible.

[0417] Figure 14 A schematic diagram of a device provided in an embodiment of this application is given. The communication device 1400 may be... Figure 4 The first network element or its circuit system described in the illustrated embodiment is used to implement the method corresponding to the first network element in the above method embodiments. Alternatively, the communication device 1400 may be... Figure 4 The second network element or its circuit system, as shown in the embodiment, is used to implement the method corresponding to the second network element in the above method embodiments. Alternatively, the communication device 1400 may be... Figure 5 or Figure 6 The AF or its circuit system described in the illustrated embodiment is used to implement the method corresponding to the AF in the above method embodiments. Alternatively, the communication device 1400 may be... Figure 7 or Figure 8 The IMS AS or its circuit system described in the illustrated embodiment is used to implement the method corresponding to the IMS AS in the above method embodiments. Alternatively, the communication device 1400 may be... Figure 7 or Figure 8 The S-CSCF or its circuitry described in the illustrated embodiment is used to implement the method corresponding to the S-CSCF in the above method embodiments. Alternatively, the communication device 1400 may be... Figure 9 or Figure 10The P-CSCF or its circuitry described in the illustrated embodiment is used to implement the method corresponding to the P-CSCF in the above method embodiments. Alternatively, the communication device 1400 may be... Figures 11-13 The SMS service network element or its circuit system, as shown in any of the accompanying drawings, is used to implement the method corresponding to the SMS service network element in the above method embodiments. Alternatively, the communication device 1400 may be... Figures 5-7 , Figure 9 ,or Figure 11 The AMF or its circuitry, as shown in any of the accompanying drawings, is used to implement the method corresponding to the AMF in the above method embodiments. Alternatively, the communication device 1400 may be... Figure 8 , Figure 10 , Figure 12 or Figure 13 The MME or circuit system of any of the embodiments shown in the accompanying drawings is used to implement the method corresponding to the MME in the above method embodiments. For example, one type of circuit system is a chip system.

[0418] The communication device 1400 includes at least one processor 1401. The processor 1401 can be used for internal processing within the device to implement certain control processing functions. Optionally, the processor 1401 includes instructions. Optionally, the processor 1401 can store data. Optionally, different processors can be independent devices, located in different physical locations, or located on different integrated circuits. Optionally, different processors can be integrated into one or more processors, for example, integrated on one or more integrated circuits.

[0419] Optionally, the communication device 1400 includes one or more memories 1403 for storing instructions. Optionally, the memories 1403 may also store data. The processor and the memories may be separate or integrated together.

[0420] Optionally, the communication device 1400 includes a communication line 1402 and at least one communication interface 1404. Since the memory 1403, communication line 1402, and communication interface 1404 are all optional, therefore... Figure 14 All are represented by dashed lines.

[0421] Optionally, the communication device 1400 may further include a transceiver and / or an antenna. The transceiver can be used to send information to or receive information from other devices. The transceiver may be referred to as a transceiver unit, transceiver circuit, input / output interface, etc., and is used to realize the transmission and reception functions of the communication device 1400 via the antenna. Optionally, the transceiver includes a transmitter and a receiver. For example, the transmitter can be used to generate a radio frequency (RF) signal from a baseband signal, and the receiver can be used to convert the RF signal back into a baseband signal.

[0422] Processor 1401 may include a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs according to the present application.

[0423] Communication line 1402 may include a path for transmitting information between the aforementioned components.

[0424] Communication interface 1404 uses any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), wired access network, etc.

[0425] Memory 1403 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. Memory 1403 may exist independently and be connected to processor 1401 via communication line 1402. Alternatively, memory 1403 may be integrated with processor 1401.

[0426] The memory 1403 stores computer execution instructions for implementing the scheme of this application, and its execution is controlled by the processor 1401. The processor 1401 executes the computer execution instructions stored in the memory 1403, thereby realizing... Figures 4 to 13 The steps performed by the first or second network element in any of the embodiments shown in the accompanying drawings.

[0427] Optionally, the computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0428] In a specific implementation, as one embodiment, the processor 1401 may include one or more CPUs, for example... Figure 14 CPU0 and CPU1 in the CPU.

[0429] In a specific implementation, as one example, the communication device 1400 may include multiple processors, for example... Figure 14 Processors 1401 and 1405 are mentioned. Each of these processors can be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor here can refer to one or more devices, circuits, and / or processing cores used to process data (such as computer program instructions).

[0430] when Figure 14 When the device shown is a chip, such as a chip for a first network element or a chip for a second network element, the chip includes a processor 1401 (and may also include a processor 1405), a communication line 1402, and a communication interface 1404. Optionally, it may include a memory 1403. Specifically, the communication interface 1404 may be an input interface, pins, or circuits, etc. The memory 1403 may be a register, cache, etc. The processor 1401 and processor 1405 may be a general-purpose CPU, microprocessor, ASIC, or one or more integrated circuits for controlling the execution of a program that controls the communication method of any of the above embodiments.

[0431] This application embodiment can divide the device into functional modules according to the above method example. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. The module division in this application embodiment is illustrative and only represents one logical functional division; in actual implementation, other division methods may be used. For example, in the case of dividing the device into functional modules corresponding to each function... Figure 15This is a schematic diagram of an apparatus. The apparatus 1500 may be the first network element or the second network element involved in the above-described method embodiments, or it may be a chip in the first network element or a chip in the second network element. The apparatus 1500 includes a processing unit 1502 and a transceiver unit 1501.

[0432] It should be understood that the device 1500 can be used to implement the steps performed by the first network element or the second network element in the communication method of the embodiments of this application, and the relevant features can be referred to above. Figures 4 to 13 The embodiments shown in any of the accompanying drawings will not be described in detail here.

[0433] Optional, Figure 10 The functions / implementation process of the transceiver unit 1501 and the processing unit 1502 can be obtained through Figure 14 The processor 1401 in the memory calls computer execution instructions stored in memory 1403 to implement the function. Alternatively, Figure 15 The function / implementation process of the processing unit 1502 can be achieved through... Figure 14 The processor 1401 in the memory calls computer execution instructions stored in memory 1403 to implement this. Figure 15 The function / implementation process of the transceiver unit 1501 can be obtained through Figure 14 It is implemented using the communication interface 1404.

[0434] Optionally, when the device 1500 is a chip or circuit, the function / implementation process of the transceiver unit 1501 can also be implemented through pins or circuits, etc. Optionally, the transceiver unit 1501 may include a transmitting unit and / or a receiving unit, whereby the transmitting unit implements the transmitting function and the receiving unit implements the receiving function; or, the transceiver unit 1501 may be an integral module capable of implementing both transmitting and / or receiving functions. Optionally, the transceiver unit 1501 can be implemented using a transceiver.

[0435] This application also provides a computer-readable storage medium storing a computer program or instructions. When the computer program or instructions are executed, they implement the methods performed by the first network element or the second network element in the aforementioned method embodiments. Thus, the functions described in the above embodiments can be implemented as software functional units and sold or used as independent products. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to it, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0436] This application also provides a computer program product, which includes: computer program code, which, when run on a computer, causes the computer to perform the method executed by the first network element or the second network element in any of the foregoing method embodiments.

[0437] This application also provides a processing device, including a processor and an interface; the processor is used to execute the method executed by the first network element or the second network element involved in any of the above method embodiments.

[0438] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer 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 can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can 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 can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0439] The various illustrative logic units and circuits described in the embodiments of this application can be implemented or operate the described functions using a general-purpose processor, digital signal processor (DSP), ASIC, field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor; alternatively, it can be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented using a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0440] The steps of the methods or algorithms described in the embodiments of this application can be directly embedded in hardware, software units executed by a processor, or a combination of both. The software units can be stored in RAM, flash memory, ROM, erasable programmable read-only memory (EPROM), EEPROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and storage medium can be disposed in an ASIC, which can be disposed in the terminal device. Optionally, the processor and storage medium can also be disposed in different components of the terminal device.

[0441] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0442] The contents of the various embodiments of this application can be referenced to each other. Unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0443] It is understood that in the embodiments of this application, the first network element and / or the second network element may perform some or all of the steps in the embodiments of this application. These steps or operations are merely examples. In the embodiments of this application, other operations or variations of various operations may also be performed. Furthermore, the steps may be performed in different orders as presented in the embodiments of this application, and it is not necessary to perform all the operations in the embodiments of this application.

Claims

1. A communication method, characterized in that, The method is applied to a first network element, and the method includes: Receive a first request from the calling terminal, the first request being used to request a first service; Send the first request to the called terminal; After determining that the first service has failed, a first message is sent to a second network element in the core network. The first message is used to trigger the second network element to send an elastic notification to the called terminal. The elastic notification is used to indicate information about the first service and / or to indicate information about the calling terminal.

2. The method according to claim 1, characterized in that, Before sending the first message to the second network element in the core network, the method further includes: It is determined that the called terminal accesses the core network via satellite.

3. The method according to claim 1 or 2, characterized in that, Before sending the first message to the second network element in the core network, the method further includes: The information identifying the calling terminal is included in the first information, wherein the first information includes information about one or more terminals that are permitted to send flexible notifications.

4. The method according to claim 3, characterized in that, The flexible notification is used to indicate information about the calling terminal, including: The elastic notification includes a first index, which is the index of the calling terminal's information in the first information, wherein the first information includes information of one or more terminals and the corresponding index.

5. The method according to any one of claims 1 to 4, characterized in that, The first network element is an Internet Protocol Multimedia Subsystem Application Server (IMS AS), Service Call Session Control Function (S-CSCF), Proxy Call Session Control Function (P-CSCF), or SMS service network element within the core network that serves the called terminal. The determination of the first service failure includes: Receive a second message, and determine that the first service has failed based on the second message; or, When the first timer corresponding to the first request expired, no response message corresponding to the first request was received.

6. The method according to claim 5, characterized in that, The failure of the first service is determined based on the second message, including: The second message is used to indicate that the first service has failed, or to indicate that the request has timed out.

7. The method according to any one of claims 1 to 6, characterized in that, The first message is the message corresponding to the service interface, and the core network is the fifth-generation core network 5GC; or, The first message is the message corresponding to the non-service interface, and the core network is the evolved packet core (EPC).

8. A communication method, characterized in that, The method is applied to a second network element, and the method includes: Receive a first message, the first message being used to trigger the second network element to send an elastic notification to the called terminal, the elastic notification being used to indicate information of the first service and / or information of the calling terminal corresponding to the first service; Send the elastic notification, wherein the elastic notification is used to indicate information about the first service and / or information about the calling terminal.

9. The method according to claim 8, characterized in that, Sending the elastic notification includes: Send the elastic notification to the access network device, the elastic notification being used to instruct the access network device to send information indicating the first service and / or the calling terminal to the called terminal in a manner different from paging; The method different from paging includes: the transmission power of the information used to indicate the first service and / or the information of the calling terminal is greater than the transmission power of the paging message, and / or, the number of times the information used to indicate the first service and / or the information of the calling terminal is transmitted is greater than the number of times the paging message is transmitted.

10. The method according to claim 8 or 9, characterized in that, The first message is the message corresponding to the service interface, and the core network is 5GC; or, The first message is the message corresponding to the non-service interface, and the core network is EPC.

11. The method according to any one of claims 8 to 10, characterized in that, Before sending the elastic notification, the method further includes: Send a paging message, the paging message being used to page the called terminal; No response was received from the called terminal.

12. The method according to any one of claims 8 to 11, characterized in that, The method further includes: Receive first information, the first information including information about one or more terminals that are allowed to make flexible notifications; Send the first information to the fourth network element.

13. The method according to claim 12, characterized in that, The flexible notification is used to indicate information about the calling terminal, including: The elastic notification includes a first index, which is the index of the calling terminal's information in the first information, wherein the first information includes information of one or more terminals and the corresponding index.

14. A communication device, characterized in that, The communication device includes a module for performing the method as described in any one of claims 1 to 7, or a module for performing the method as described in any one of claims 8 to 13.

15. A communication device, characterized in that, The communication device includes a processor for performing the method as described in any one of claims 1 to 7, or the method as described in any one of claims 8 to 13.

16. A communication system, characterized in that, Including the first network element and the second network element, among which, The first network element is used to perform the method as described in any one of claims 1 to 7; The second network element is used to perform the method as described in any one of claims 8 to 13.

17. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program that, when run on a computer, causes the method as described in any one of claims 1 to 7 to be performed, or causes the method as described in any one of claims 8 to 13 to be performed.

18. A computer program product, characterized in that, The computer program product includes a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1 to 7, or causes the computer to perform the method as described in any one of claims 8 to 13.

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