Communication method, communication apparatus, and storage medium

Abstract

The present application relates to a communication method and apparatus, and a storage medium. The method comprises: a terminal sending a network connection request to a satellite, the network connection request being used for instructing the terminal to establish a network connection with the satellite; and receiving a target response message returned to the terminal by a device on the satellite. By means of said method, an IoT terminal device can establish a network connection with a network on the basis of a satellite having on-board store-and-forward characteristics, such that full communication coverage is enhanced and the reliability of terminal communication is ensured, thereby providing a communication basis for terminals in remote areas, and better meeting the communication requirements of terminal devices.

Description

Communication method, communication device, and storage medium Cross-references This application refers to Chinese Patent Application No. 2024100449758, filed on January 11, 2024, entitled “Communication Method, Apparatus, Computer Equipment and Storage Medium,” which is incorporated herein by reference in its entirety. Technical Field The present application relates to the field of on-board store-and-forward technology, and in particular to a communication method, a communication device, a storage medium, and a computer program product. Background Art In areas where it's difficult to deploy base stations, gateways, and other equipment, information exchange can be achieved via satellite. By deploying 4G / 5G base stations on satellites, the cost of ground-based satellite deployment can be reduced. However, due to the limited deployment of gateways, satellites may not be able to connect to them in real time while in the air, and data may not be immediately transmitted back to the core network. In actual application scenarios, due to limited satellite equipment resources, only a minimal number of core network devices can be deployed on the satellite. However, with so many Internet of Things (IoT) devices, it's impossible to store the subscription information of each device on the satellite. Therefore, related core network equipment, such as the Home Subscriber Server (HSS), Authentication Server Function (AUSF), and Unified Data Management (UDM), are deployed on the ground. Therefore, when the satellite is in onboard store-and-forward mode, User Equipment (UE) registration requests cannot be sent to the ground in a timely manner to complete service authorization. Therefore, how to promptly authenticate the UE is a pressing issue. Summary of the Invention Based on this, the present application provides a communication method, a communication device, a computer-readable storage medium, and a computer program product. In a first aspect, the present application provides a communication method, applied to a terminal, the method comprising: A network connection request is sent to a satellite, where the network connection request is used to instruct the terminal to establish a network connection with the satellite. A target response message is received, which is returned by the device on the satellite to the terminal. In some embodiments, the network connection request includes a capability of supporting store-and-forwarding and a terminal identifier. In some embodiments, receiving a target response message returned by the device on the satellite to the terminal includes: Receive a first request acceptance response message returned by the device on the satellite to the terminal, where the first request acceptance response message carries the data retention period of the on-board storage and forwarding and the data storage quota of the on-board storage and forwarding. The first request acceptance response message is generated by the satellite after determining that the terminal is in a network accessible state based on the terminal identifier and the capability to support storage and forwarding. In some embodiments, the network connection request includes a capability of supporting store-and-forward and a terminal identifier; and receiving a target response message returned by the device on the satellite to the terminal includes: Receive a second request acceptance response message returned by the device on the satellite to the terminal, where the second request acceptance response message carries the data retention period of the on-board storage and forwarding and the data storage quota of the on-board storage and forwarding. The second request acceptance response message is generated by the satellite after determining that the terminal is in a restricted transmission state based on a second configuration policy, the terminal identifier, and the capability of supporting storage and forwarding. In some embodiments, the network connection request includes a capability of supporting store-and-forward; and receiving a target response message returned by the device on the satellite to the terminal includes: receiving a temporary storage request response message returned by the device on the satellite to the terminal, where the temporary storage request response message is generated by the device on the satellite based on the satellite being in a store-and-forward mode, the terminal meeting a condition for initial satellite access, and the terminal having a store-and-forward support capability; and the temporary storage request response message carries a satellite identifier. In some embodiments, the network connection request includes a capability of supporting store-and-forward; and receiving a target response message returned by the device on the satellite to the terminal includes: receiving a rejection response message returned by the device on the satellite to the terminal, where the rejection response message is generated by the device on the satellite based on the satellite being in store-and-forward mode, the terminal meeting a condition for initial satellite access, and the terminal having a store-and-forward support capability; and the rejection response message carries a rejection reason message and a satellite identifier. In some embodiments, the target response message further carries a satellite identifier and a bearer session identifier. In some embodiments, the target response message also carries the satellite return time. In some embodiments, before the step of sending a network connection request to the satellite, the method further comprises: Receive satellite broadcast messages. In some embodiments, the satellite broadcast message carries a store-and-forward feature and / or a satellite identification. In some embodiments, the method further comprises: Sending to the satellite the data to be transmitted that satisfies the data storage quota. In a second aspect, the present application provides a communication method, applied to a satellite, the method comprising: receiving a network connection request sent by a terminal, where the network connection request is used to instruct the terminal to establish a network connection with the satellite; A target response message is generated based on the network connection request, and the target response message is returned to the terminal. In some embodiments, the network connection request carries a terminal identification and supports store-and-forward capabilities. In some embodiments, generating a target response message based on the network connection request and returning the target response message to the terminal includes: Determining, based on the terminal identification and the ability to support store-and-forward, whether the terminal is in a network-accessible state, and determining, based on the satellite coverage availability time, a data retention period for on-board store-and-forward and a data storage quota for on-board store-and-forward; A first request acceptance response message is returned to the terminal, where the first request acceptance response message carries the data retention period of the on-board store-and-forward and the data storage quota of the on-board store-and-forward. In some embodiments, the method further comprises: If the satellite covers the gateway and receives the data to be transmitted sent by the terminal that meets the data storage quota, the satellite forwards the data to be transmitted. In some embodiments, if the satellite covers the gateway and receives the data to be transmitted sent by the terminal that meets the data storage quota, forwarding the data to be transmitted includes: If the satellite covers the gateway and receives the data to be transmitted sent by the terminal that meets the data storage quota, performing secondary authentication processing on the terminal; If it is determined that the terminal passes the secondary authentication, the data to be transmitted is forwarded. In some embodiments, the network connection request carries a terminal identifier and a capability of supporting store-and-forwarding, and generating a target response message based on the network connection request and returning the target response message to the terminal includes: Determining, based on the second configuration policy, the terminal identifier, and the ability to support store-and-forward, that the terminal is in a restricted transmission state, and determining, based on the satellite coverage available time, a data retention period for on-board store-and-forward and a data storage quota for on-board store-and-forward; A second request acceptance response message is returned to the terminal, where the second request acceptance response message carries the data retention period of the on-board store-and-forward and the data storage quota of the on-board store-and-forward. In some embodiments, the method further comprises: If the satellite covers the gateway station, the contract information of the terminal is obtained; if it is determined based on the contract information that the terminal authentication is passed, and the data to be transmitted sent by the terminal that meets the data storage quota is received, the data to be transmitted is forwarded, and the restricted transmission status of the terminal is updated to an unrestricted transmission status. In some embodiments, the method further comprises: If it is detected that the terminal obtains coverage of the satellite, a status update message is sent to the terminal, where the status update message indicates that the restricted transmission state of the terminal is updated to the unrestricted transmission state. In some embodiments, the target response message further carries a satellite identifier and a bearer session identifier. In some embodiments, generating a target response message based on the network connection request and returning the target response message to the terminal includes: generating a temporary storage request response message based on the satellite being in a store-and-forward mode, the terminal meeting a condition for initial satellite access, and the terminal having a store-and-forward support capability; The temporary storage request response message is returned to the terminal, where the temporary storage request response message carries a satellite identifier. In some embodiments, generating a target response message based on the network connection request and returning the target response message to the terminal includes: generating a rejection response message based on the satellite being in a store-and-forward mode, the terminal meeting a condition for initial satellite access, and the terminal having a store-and-forward support capability; The rejection response message is returned to the terminal, where the rejection response message carries a rejection reason message and a satellite identifier. In some embodiments, the method further comprises: A broadcast message is sent, where the broadcast message is used to instruct the terminal to connect to the satellite. In some embodiments, the broadcast message includes a store-and-forward feature and / or a satellite identification. In some embodiments, the target response message also carries the satellite return time. In a third aspect, the present application provides a communication device, applied to a terminal, the device comprising: A first sending unit, configured to send a network connection request to a satellite, wherein the network connection request is used to instruct the terminal to establish a network connection with the satellite; The first receiving unit is configured to receive a target response message returned by the device on the satellite to the terminal. In a fourth aspect, the present application provides a communication device for use in a satellite, the device comprising: a second receiving unit, configured to receive a network connection request sent by a terminal, wherein the network connection request is used to instruct the terminal to establish a network connection with the satellite; The second sending unit is configured to generate a target response message based on the network connection request and return the target response message to the terminal. In a fifth aspect, the present application provides a communication device, including a memory, a transceiver, and a processor: A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and executing the computer program to implement the steps of the communication method provided in the above embodiment. In a sixth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the communication method provided in the above embodiment. In a seventh aspect, the present application also provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the communication method provided in the above embodiment. With the aforementioned communication method, apparatus, and storage medium, a terminal can send a network connection request to a satellite, instructing the terminal to establish a network connection with the satellite, and receive a target response message returned by a device on the satellite to the terminal. By employing this method, a terminal IoT device can establish a network connection with a satellite based on the onboard store-and-forward feature, improving the comprehensiveness of communication coverage and ensuring the reliability of terminal communications. This provides a communication foundation for terminals in remote areas and better meets the communication needs of terminal devices. The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the embodiments below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to denote the same components. In the drawings: FIG1 is a diagram illustrating an application environment of a communication method according to an embodiment of the present application; FIG2 is a flow chart of a communication method according to an embodiment of the present application; FIG3 is a flow chart of a communication method according to an embodiment of the present application; FIG4 is a flow chart of a communication method according to an embodiment of the present application; FIG5 is a flow chart of a communication method according to an embodiment of the present application; FIG6 is a flow chart of a communication method according to an embodiment of the present application; FIG7 is a signaling diagram of a communication method in an embodiment of the present application; FIG8 is a signaling diagram of a communication method in an embodiment of the present application; FIG9 is a signaling diagram of a communication method in an embodiment of the present application; FIG10 is a structural block diagram of a communication device according to an embodiment of the present application; FIG11 is a block diagram of another communication device according to an embodiment of the present application; FIG12 is a diagram showing the internal structure of a communication device in one embodiment. DETAILED DESCRIPTION The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions. In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined. References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments. In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship. In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces). In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In the description of the embodiments of the present application, unless otherwise clearly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components or interactions between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances. The present application provides a communication method and apparatus for implementing communication between a terminal and a satellite, and between a satellite and a terrestrial network, based on an onboard store-and-forward model. The method and apparatus are based on the same patent application concept. Since the method and apparatus solve similar problems, the implementation of the apparatus and method can refer to each other, and any repetitions will not be repeated. Figure 1 shows a schematic diagram of the architecture of the communication system provided by an embodiment of the present application. As shown in Figure 1, the communication system architecture may include the following logical network elements: user UE, SAT (satellite) and ground network elements, wherein the satellite may include an evolved Node B (eNodeB), a mobility management entity MME (Mobility Management Entity), a store-and-forward network element (SFCF) and a target network element, the target network element may be a service capability exposure network element SCEF (Service Capability Exposure Function, network capability exposure function) or a serving gateway S-GW; the ground network element may include a store-and-forward management network element (SFMF), a server network element, the server network element may be a home subscriber server (HSS), a switch (P-SW), or a store-and-forward server (SandF server); optionally, 5GC and base stations may be deployed on the SAT, the 5GC including AMF, SMF, UPF, and AUSF; the functions of all network elements on the satellite may be deployed in a variety of ways, which may be new network elements or enhancements to existing network elements. AMF: core network unit, mainly responsible for registration management, connection management, access management, mobility management, as well as security and access management and authorization-related functions. SMF: core network unit, mainly responsible for creating, updating and deleting PDU (Protocol Data Unit) sessions. UPF: Core network unit, mainly responsible for user plane network traffic transmission. For IoT devices, a lightweight EPC (MME, S-GW, P-GW) or 5GC (AMF+SMF+UPF+AUSF) and base station are deployed on the same satellite, while other CIoT devices are located on the ground (or all CIoT devices may be onboard). The functions of these devices can be separated into multiple network elements or a single device; devices such as the HSS / UDM are located on the ground. Specifically, the functions of the onboard devices include processing NAS information, requiring only authentication by comparing UE and network subscription information; and optionally, assigning IP addresses to terminals and functioning as user-plane network elements. These can be independent modules or new, converged network elements. Alternatively, in the 3GPP SA1R19 requirements study, scenarios requiring data storage and forwarding on satellites include: research institutions studying animal habits and movement patterns; government agencies seeking timely warnings to mitigate or prevent disasters, such as submarine cable monitoring; and IoT devices deployed on animals or equipment in remote or remote areas without access to communication base stations, requiring data transmission via satellite communications. If latency requirements are low for the terminal device, the terminal can first upload data to the satellite, store it there (which may have a base station or core network element), and then forward the data when the satellite can connect to a gateway. It should be understood that the communication system architecture in FIG1 is merely an example of a possible application environment for the solution of the present application. Those skilled in the art will appreciate that the embodiments of the present application can be applied to the communication system architecture in FIG1 or similar to FIG1 . The communication architecture obtained by appropriate modifications and variations based on the communication system architecture in FIG1 is still applicable to the solutions of the embodiments of the present application. The technical solutions provided in the embodiments of the present application can be applicable to a variety of systems. For example, applicable systems may be long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, advanced long term evolution (LTE-A) systems, universal mobile telecommunication systems (UMTS), worldwide interoperability for microwave access (WiMAX) systems, 5G new radio (NR) systems and their evolved communication systems, etc. These various systems may include terminal devices and network equipment. The system may also include a core network part, such as an evolved packet system (EPS), a 5G system (5GS), etc. The terminal device involved in the embodiments of the present application may refer to a terminal IoT (Internet of Things) device or a CIoT (Cellular Internet of Things) device; it may also refer to a device that provides voice and / or data connectivity to a user, a handheld device with wireless connection function, or other processing devices connected to a wireless modem. In different systems, the name of the terminal device may also be different. For example, in a 5G system, the terminal device may be called a user equipment (UE). A wireless terminal device may be a USB storage device, other personal computer memory device, and a dongle. It may also communicate with one or more core networks (CN) via a radio access network (RAN). A wireless terminal device may be a mobile terminal device, such as a mobile phone (or "cellular" phone) and a computer with a mobile terminal device. For example, it may be a portable, pocket-sized, handheld, computer-built-in, or vehicle-mounted mobile device that exchanges language and / or data with a radio access network. For example, Personal Communication Service (PCS) phones, cordless phones, Session Initiated Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDAs), personal computers, tablet computers, Machine-type Communication (MTC) terminal devices, etc. Wireless terminal devices may also be referred to as systems, subscriber units, subscriber stations, mobile stations, mobile stations, remote stations, access points, remote terminal devices, access terminal devices, user terminal devices, user agents, user devices, and wireless access points and routers / modems that meet the limitations of this definition, but are not limited in the embodiments of the present application. The network device involved in the embodiments of the present application may be a base station, which may include multiple cells providing services to the terminal. Depending on the specific application scenario, the base station may also be called an access point, or may be a device in the access network that communicates with the wireless terminal device through one or more sectors on the air interface, or other names. The network device may be used to interchange received air frames with Internet Protocol (IP) packets, acting as a router between the wireless terminal device and the rest of the access network, wherein the rest of the access network may include an Internet Protocol (IP) communication network. The network device may also coordinate the attribute management of the air interface. For example, the network device involved in the embodiments of the present application may be an evolutionary network device (eNB or e-NodeB) in a long term evolution (LTE) system, a 5G base station (gNB) in a next generation system, etc., or a home evolved Node B (HeNB), a relay node, a femto, a pico base station (pico), a network test device, etc., which is not limited in the embodiments of the present application. In some network structures, network devices may include centralized unit (CU) nodes and distributed unit (DU) nodes, and the centralized unit and the distributed unit may also be arranged geographically separately. The terminal device in the embodiment of the present application sends relevant information or similar descriptions to the network side device, which only indicates that the terminal device sends the relevant information in the form of a wireless signal, and its intended recipient is the network device. The network device can obtain the relevant information by receiving the wireless signal. In an exemplary embodiment, as shown in FIG2 , a communication method is provided. The method is described by taking the application of the method to the terminal shown in FIG1 as an example. The communication method may include: Step 202: Send a network connection request to the satellite. The network connection request is used for the terminal to establish a network connection with the satellite. Optionally, the terminal sends a network connection request to the MME in the satellite. The network connection request may carry corresponding data information based on an actual application scenario, requesting to establish a network connection with the satellite. Step 204: Receive a target response message returned by the device on the satellite to the terminal. Optionally, after receiving the network connection request, the satellite may generate a target response message based on the current communication mode of the satellite and return the target response message to the terminal. The device on the satellite may be an MME. In one example, the terminal can generate a network connection request based on the ability to support store-and-forward, and send the network connection request to the satellite, where the network connection request carries an indication that the store-and-forward feature is supported. In one example, the terminal can send a network connection request to the MME in the satellite, where the network connection request carries an indication that the store-and-forward feature is supported. After the satellite receives the network connection request, the MME on the satellite can generate a target response message based on the current communication mode of the satellite, and return the target response message to the terminal. In the above communication method, a terminal can send a network connection request to the satellite, indicating that the terminal is requesting to establish a network connection with the satellite; and receive a target response message, which is returned by the device on the satellite to the terminal. By adopting this method, terminal IoT devices can establish a network connection with the network based on the satellite's onboard store-and-forward feature, improving the comprehensiveness of communication coverage and ensuring the reliability of terminal communications. This provides a communication foundation for terminals in remote areas and better meets the communication needs of terminal devices. In one embodiment, the network connection request includes a store-and-forward capability and a terminal identifier. Optionally, the store-and-forward capability may include identifier information indicating "support of the store-and-forward feature," indicating that the terminal supports the store-and-forward feature. For example, the terminal may be an IoT device that is not sensitive to latency and has low latency requirements. The terminal identifier may be device identifier information of the terminal, such as an International Mobile Subscriber Identity (IMSI). In one embodiment, the step of receiving a target response message returned by the device on the satellite to the terminal may include: The first request acceptance response message returned by the device on the satellite to the terminal is received. The first request acceptance response message carries the data retention period for on-board storage and forwarding and the data storage quota for on-board storage and forwarding. The first request acceptance response message is generated by the satellite after determining that the terminal is in a network-accessible state based on the terminal identification and the ability to support storage and forwarding. The data retention period (SandF data retention period) can be a data retention period determined based on the available time of satellite coverage, or it can be the duration of the unavailability period (Unavailability Period Duration). The data storage quota (SandF data storage quota) can be the data capacity that the satellite allows the terminal to transmit, for example, it can include the number of data transmissions and the size of each transmission, etc. Optionally, when a terminal wants to transmit information over the network, it can send a network connection request to the MME on the satellite. The terminal can generate a network connection request that carries the capability to support store-and-forward and a terminal identifier, and send the network connection request to the MME on the satellite. After receiving the network connection request, if the MME on the satellite determines that the terminal is accessible, the MME on the satellite can determine the data retention period and data storage quota for on-board store-and-forward based on the available satellite coverage time, and generate a first request acceptance response message based on the data retention period and data storage quota for on-board store-and-forward. Based on this, the MME on the satellite can return the first request acceptance response message to the terminal. After receiving the first request acceptance response message, the terminal can determine that the current terminal can transmit data to the satellite. In this embodiment, the data forwarding process can be simplified, and the user experience and the network registration efficiency of the terminal can be improved. In one embodiment, the network connection request includes a capability to support store-and-forward, a terminal identifier, and first configuration information. Optionally, the capability to support store-and-forward may include identifier information indicating "support for store-and-forward," indicating that the terminal supports the store-and-forward feature. For example, the terminal may be an IoT device that is insensitive to latency and has low requirements. The terminal identifier may be device identifier information of the terminal, such as an International Mobile Subscriber Identity (IMSI). The first configuration information may be pre-configured information, such as terminal information, specifically terminal security information, terminal subscription information, or terminal user plane information. The satellite may perform security authentication or authorization on the terminal based on the terminal information. For example, the satellite may determine, based on the terminal information, that the terminal can access the network. Accordingly, the step of receiving a target response message returned by the device on the satellite to the terminal may include: The first request acceptance response message returned by the device on the satellite to the terminal is received. The first request acceptance response message carries the data retention period for on-board storage and forwarding and the data storage quota for on-board storage and forwarding; the first configuration information is used to enable the satellite to authenticate the terminal, and the first request acceptance response message is generated by the satellite after determining that the terminal is in a network-accessible state based on the first configuration policy, the terminal identifier, the ability to support storage and forwarding, and the first configuration information. The data retention period (SandF data retention period) can be a data retention period determined based on the available time of satellite coverage, or it can be the duration of the unavailability period (Unavailability Period Duration); the data storage quota (SandF data storage quota) can be the data capacity that the satellite allows the terminal to transmit, for example, it can include the number of data transmissions and the size of each transmission, etc. Optionally, when a terminal wants to transmit information over a network, it may send a network connection request to an MME on a satellite. The terminal may generate a network connection request that carries a store-and-forward capability, a terminal identifier, and first configuration information, and send the network connection request to the MME on the satellite. After receiving the network connection request, the MME on the satellite may first authenticate the terminal based on the first configuration policy. If the MME on the satellite determines that the terminal is accessible, the MME on the satellite may determine a data retention period and a data storage quota for on-board store-and-forward based on the available satellite coverage time, and generate a first request acceptance response message based on the data retention period and the data storage quota for on-board store-and-forward. Based on this, the MME on the satellite may return the first request acceptance response message to the terminal. After receiving the first request acceptance response message, the terminal may determine that the current terminal can transmit data to the satellite. In this embodiment, the first configuration information of the terminal is sent to the satellite during the registration process, thereby avoiding secondary data interaction between the terminal and the satellite, simplifying the data forwarding process, and improving user experience and network registration efficiency of the terminal. In one embodiment, the network connection request includes the capability of supporting store-and-forward and a terminal identifier; optionally, the capability of supporting store-and-forward may be identifier information indicating "supporting store-and-forward feature", indicating that the terminal supports the store-and-forward feature, for example, the terminal may be an IoT device that is not sensitive to latency and has low requirements, etc.; the terminal identifier may be the device identification information of the terminal, etc., for example, it may be an IMSI. Accordingly, the step of “receiving a target response message returned by the device on the satellite to the terminal” may include: The receiving device on the satellite returns a second request acceptance response message to the terminal. The second request acceptance response message carries the on-board store-and-forward data retention period and the on-board store-and-forward data storage quota. The satellite generates the second request acceptance response message after determining that the terminal is in a restricted transmission state based on a second configuration policy, the terminal identifier, and the store-and-forward capability. The second configuration policy may be a pre-configured operator configuration policy. Specifically, if the terminal supports the store-and-forward feature, the terminal is determined to be in a restricted transmission state, enabling the terminal to send limited data to the satellite. Optionally, when a terminal desires to transmit information over a network, it may send a network connection request to an MME on a satellite. The terminal may generate a network connection request based on the store-and-forward capability and the terminal identifier, and send the network connection request to the satellite. After receiving the network connection request from the terminal, the MME on the satellite may determine that the terminal is in a restricted transmission state based on the terminal identifier reported by the terminal, the store-and-forward capability, and a pre-configured second configuration policy. The MME on the satellite may determine a data retention period and a data storage quota for on-board store-and-forward based on the available satellite coverage time, and generate a second request acceptance response message. Based on this, the MME on the satellite may return the second request acceptance response message to the terminal. After receiving the second request acceptance response message, the terminal may determine that the terminal can currently transmit limited data to the satellite. In an example, the second request acceptance response message may also carry a satellite identifier, a bearer session identifier (Bearer ID), etc. The satellite may return the request acceptance response message to the terminal. In this embodiment, a network connection request carrying a store-and-forward capability may be sent to the satellite, causing the satellite to return a second request acceptance response message to the terminal, thereby quickly establishing communication between the terminal and the satellite. In one embodiment, the network connection request includes a store-and-forward capability. The store-and-forward capability may include identification information indicating "support for store-and-forward feature," indicating that the terminal supports the store-and-forward feature. For example, the terminal may be an IoT device that is not sensitive to latency and has low requirements. Accordingly, the step of “receiving a target response message returned by the device on the satellite to the terminal” may include: The receiving device on the satellite returns a temporary storage request response message to the terminal. The request for temporary storage response message is generated by the device on the satellite based on the satellite being in store-and-forward mode, the terminal meeting the conditions for initial satellite access, and the terminal's ability to support store-and-forward; the request for temporary storage response message carries a satellite identifier. Optionally, in a scenario where a terminal needs to establish a network connection with a satellite, the terminal generates a network connection request carrying a capability of supporting store-and-forwarding and sends the network connection request to the satellite; after receiving the network connection request carrying the capability of supporting store-and-forwarding, the satellite can determine that the terminal sending the network connection request supports the store-and-forward feature based on the capability of supporting store-and-forwarding carried in the network connection request; if the satellite is currently in store-and-forward mode and the terminal sending the network connection request is a terminal accessing the satellite for the first time, the satellite can store the terminal identification and terminal capabilities of the terminal, and generate a request temporary storage response message, and return the request temporary storage response message to the terminal, indicating that the satellite has cached the network connection request sent by the terminal. Optionally, after receiving the temporary storage request response message sent by the satellite, the terminal may switch to a low-power mode, such as a power-saving mode. In one example, before switching to power-saving mode, the terminal may determine the next wake-up time based on the ephemeris information. After determining the next wake-up time, the terminal may switch to power-saving mode. After the current time reaches the next wake-up time, the terminal may exit power-saving mode and switch to normal operation. The ephemeris information may be a table of the precise position or trajectory of a celestial body over time, as a function of time. Optionally, after the terminal has coverage from the satellite, it can initiate an attach request again, i.e., send the network connection request to the satellite, which carries the store-and-forward capability. If the MME in the satellite determines, based on the terminal's terminal identifier, that this is not a first-time access terminal, the satellite can authenticate the terminal based on locally stored authentication information and send a message to the terminal containing information required for the terminal to authenticate the network, completing bidirectional authentication. Another possible implementation is that after the terminal has coverage from the satellite, it can establish an RRC connection with a satellite that matches the satellite identifier carried in the rejection response message. Based on this RRC connection, the terminal can initiate an attach request again, i.e., send the network connection request to the satellite via the RRC connection, which carries the store-and-forward capability. After receiving the network connection request, the satellite can perform bidirectional authentication based on the terminal identifier carried in the network connection request and the terminal's locally stored authentication information. Based on this, after the satellite determines that the terminal has passed authentication, the satellite can accept the network connection request sent by the terminal, determine the data retention period based on the satellite coverage available time, and determine the data storage quota corresponding to the terminal, generate a request acceptance response message based on the data retention period and the data storage quota, and return the request acceptance response message to the terminal. In this embodiment, by sending a network connection request with storage and forwarding support capability to the satellite by the terminal, reliable communication between the terminal device and the satellite can be achieved. By prompting the terminal that the network request has been temporarily stored by the satellite through the request temporary response message, the terminal can promptly initiate a request to re-access the network when it is covered by the satellite in the subsequent process, thereby improving the flexibility of the terminal's network access. In one embodiment, the network connection request includes a store-and-forward capability. The store-and-forward capability may include identification information indicating "support for store-and-forward feature," indicating that the terminal supports the store-and-forward feature. For example, the terminal may be an IoT device that is not sensitive to latency and has low requirements. Accordingly, the step of “receiving a target response message returned by the device on the satellite to the terminal” may include: The receiving device on the satellite returns a rejection response message to the terminal. The device on the satellite generates a rejection response message based on the fact that the satellite is in store-and-forward mode, the terminal meets the conditions for initial satellite access, and the terminal's ability to support store-and-forward; the rejection response message carries a rejection reason message and a satellite identifier. Optionally, in a scenario where a terminal needs to establish a network connection with a satellite, it generates a network connection request that carries a store-and-forward capability and sends the network connection request to the satellite. The satellite can determine, based on the store-and-forward capability carried in the network connection request, whether the terminal sending the network connection request supports the store-and-forward feature. If the satellite is currently in store-and-forward mode and the terminal sending the network connection request is accessing the satellite for the first time, the satellite can temporarily store the network connection request corresponding to the terminal, store the terminal identifier and terminal capabilities of the terminal, generate a rejection response message that carries a rejection reason message and a satellite identifier, and return the rejection response message to the terminal. The rejection reason message can be a request cache message, that is, the satellite is in on-board store-and-forward mode and the terminal supports on-board store-and-forward mode, indicating that the satellite has cached the network connection request sent by the terminal. In one example, if the satellite covers the gateway, that is, if the feeder link between the satellite and the ground is available (Feeder link is available), the MME in the satellite can send a network connection request to the ground network element through the ground C-SCN-Ground, obtain the terminal's subscription information (authentication information) through the ground network element, and store the terminal's authentication information in the satellite. Optionally, after the terminal has coverage from the satellite, it can initiate an attach request again, i.e., send the network connection request to the satellite, with the store-and-forward capability. If the MME in the satellite determines that the terminal is not accessing for the first time based on the terminal identifier, the satellite can authenticate the terminal based on locally stored authentication information and send a message to the terminal containing information required for the terminal to authenticate the network, completing bidirectional authentication. Another possible implementation method is that after the terminal has coverage from the satellite, it can establish an RRC connection with a satellite that matches the satellite identifier carried in the rejection response message. Based on this RRC connection, the terminal can initiate an attach request again, i.e., send the network connection request to the satellite via the RRC connection, with the store-and-forward capability. After receiving the network connection request, the satellite can perform bidirectional authentication based on the terminal identifier carried in the network connection request and the terminal's locally stored authentication information. Based on this, after the satellite determines that the terminal has passed authentication, the satellite can accept the network connection request sent by the terminal, determine the data retention period based on the satellite coverage available time, and determine the data storage quota corresponding to the terminal, generate a request acceptance response message based on the data retention period and the data storage quota, and return the request acceptance response message to the terminal. In this embodiment, through multiple requests between the terminal and the satellite, the terminal IoT device can register with the network through the satellite with on-board storage and forwarding characteristics, thereby realizing communication between the terminal device and the ground through the satellite and improving communication reliability. In one embodiment, the step of “receiving a target response message returned by the device on the satellite to the terminal” may include: Receive a connection response message returned by the device on the satellite to the terminal. Among them, the connection response message is a response message to the network connection request, the network connection request carries the terminal identification and the ability to support storage and forwarding, and the connection response message carries the data retention period and data storage quota; the terminal identification can be the terminal's device identification information, etc., for example, it can be IMSI; the target response message can be a connection response message. Optionally, the terminal can generate a network connection request based on the terminal identification and the ability to support storage and forwarding, and send the network connection request to the satellite; after receiving the network connection request, the satellite can parse the network connection request, obtain the terminal identification and the ability to support storage and forwarding carried by the network connection request, and determine the data retention period based on the satellite coverage available time, and determine the data storage quota corresponding to the terminal, generate a connection response message based on the data retention period and the data storage quota, and return the connection response message to the terminal. In this embodiment, communication between the terminal and the satellite can be achieved, and a connection between the terminal and the satellite can be established, providing a communication basis for subsequent data forwarding. In one embodiment, the target response message also carries a satellite identifier and a bearer session identifier. Optionally, when generating a target response message, the satellite may also generate a target response message that also carries a satellite identifier and a bearer session identifier. For example, the satellite may generate a first request acceptance response message that carries the satellite identifier and the bearer session identifier, and may also generate a second request acceptance response message that carries the satellite identifier and the bearer session identifier. Based on the satellite identifier carried in the target response message, the terminal may send data to be transmitted to a satellite whose identification information is consistent with the satellite identifier. In one embodiment, the target response message also carries the satellite return time. Optionally, the satellite return time may be the time when the satellite returns next time. The terminal may, based on the satellite return time carried in the target response message, re-initiate a network connection request to the satellite when the satellite return time is reached or after an interval of the satellite return time. In this embodiment, the terminal can accurately initiate a network connection request to the satellite in a timely manner after the satellite returns. In one embodiment, before the step of sending the network connection request to the satellite, the method further comprises: Receive satellite broadcast messages. Optionally, the satellite can send a broadcast message within the communication coverage of the satellite. After being turned on, the terminal can search for the network and reside there. After receiving the broadcast message sent by the satellite, it can send a network connection request to the satellite that sent the broadcast message based on the broadcast message. In this embodiment, the terminal may initiate a registration request to a satellite in a communicable state based on the received broadcast message. In one example, the satellite broadcast message carries a store-and-forward feature and / or a satellite identification. The broadcast message includes a store-and-forward feature and / or a satellite ID. The store-and-forward feature indicates that the satellite is in onboard store-and-forward mode, i.e., capable of performing store-and-forward satellite operations (SandF Satellite Operations). For example, a base station or some core network elements can be deployed on the satellite, and a terminal establishes a service link with the satellite to transmit signaling or data. When the satellite moves to establish a feeder link with the ground, the signaling or data can be exchanged with the ground core network through a gateway. The satellite ID represents the satellite's identifier, such as the satellite number. Optionally, the terminal may parse the broadcast message to obtain the store-and-forward feature and / or satellite ID carried in the broadcast message. In one example, the terminal may obtain the store-and-forward feature and satellite ID carried in the broadcast message, the terminal may obtain the store-and-forward feature carried in the broadcast message, the terminal may obtain the satellite ID carried in the broadcast message, and so on. In one embodiment, the communication method further includes: Sends data to the satellite to be transmitted that satisfies the data storage quota. Optionally, when the terminal has data meeting the emergency transmission condition, the terminal may extract the data to be transmitted from the data meeting the emergency transmission condition based on the data storage quota, and send the data to be transmitted to the satellite. In one example, the terminal may send the data to be transmitted to a target network element in the satellite. After receiving the data to be transmitted, the target network element may associate the data to be transmitted with a terminal identifier of the terminal, which is the terminal that sent the data to be transmitted, and forward the data to the ground network element. Optionally, the target network element may be an MME in the satellite, or a store-and-forward network element in the satellite. When a session is established, the target network element may also be a P-GW. In this embodiment, data transmission between the terminal and the ground network element can be achieved through satellite, thereby improving the comprehensiveness of communication coverage and ensuring the reliability of terminal communication, making communication possible for terminals in remote areas. In an exemplary embodiment, as shown in FIG3 , a communication method is provided, which is applied to a satellite. The communication method includes: Step 302: Receive a network connection request sent by a terminal. The network connection request is used to instruct the terminal to request to establish a network connection with the satellite. Optionally, the satellite may receive a network connection request sent by the terminal and parse the network connection request. Step 304: Generate a target response message based on the network connection request, and return the target response message to the terminal. Optionally, the MME in the satellite may receive the network connection request sent by the terminal, and may generate a target response message based on the current communication mode of the satellite, and return the target response message to the terminal. In this embodiment, the terminal IoT device can establish a network connection with a satellite in on-board storage and forwarding mode, thereby improving the comprehensiveness of communication coverage, ensuring the reliability of terminal communication, providing a communication basis for terminals in remote areas, and better meeting the communication needs of terminal devices. In one embodiment, the network connection request carries a terminal identifier and a store-and-forward capability. The store-and-forward capability may include identifier information indicating "support for the store-and-forward feature," indicating that the terminal supports the store-and-forward feature. For example, this may indicate that the terminal is an IoT device that is not sensitive to latency and has low requirements. In one embodiment, the step of “generating a target response message based on the network connection request and returning the target response message to the terminal” may include: Based on the terminal identification and the ability to support storage and forwarding, it is determined that the terminal is in a network accessible state, and based on the available satellite coverage time, the data retention period for on-board storage and forwarding and the data storage quota for on-board storage and forwarding are determined; and a first request acceptance response message is returned to the terminal. The first request acceptance response message carries the data retention period of on-board storage and forwarding and the data storage quota of on-board storage and forwarding, and the target response message may be the first request acceptance response message. Optionally, after receiving a network connection request sent by a terminal, the satellite can determine that the terminal is in a network accessible state based on the terminal identification reported by the terminal and the ability to support storage and forwarding. The MME in the satellite can determine the data retention period for on-board storage and forwarding based on the available satellite coverage time, and the MME in the satellite can determine the data storage quota for on-board storage and forwarding. Optionally, the satellite may generate a first request acceptance response message based on the determined data retention period of on-board storage and forwarding and the data storage quota of on-board storage and forwarding. In an example, the first request acceptance response message may also carry a satellite identifier, a bearer session identifier (Bearer ID), etc. The satellite may return the first request acceptance response message to the terminal. In one example, if the satellite establishes a session based on the information reported by the terminal, the satellite may encapsulate the data storage quota of on-board store-and-forward into NAS information and return the NAS information to the terminal. In this embodiment, the satellite may determine that the terminal is in a network-accessible state and return a first request acceptance response message to the terminal, thereby quickly establishing communication between the terminal and the satellite. In one embodiment, the network connection request carries a terminal identifier, a store-and-forward capability, and first configuration information. Optionally, the first configuration information may include terminal security information, terminal subscription information, or user plane information of the terminal. The satellite performs security authentication or authorization on the terminal based on the first configuration information. For example, the satellite may determine that the terminal can access the network based on the first configuration information. The store-and-forward capability may include identifier information indicating "support for store-and-forward feature," indicating that the terminal supports the store-and-forward feature. For example, the terminal may be an IoT device that is not sensitive to latency and has low latency requirements. Accordingly, as shown in FIG4 , the step of “generating a target response message based on the network connection request and returning the target response message to the terminal” may include: Step 402: Based on the first configuration policy, the terminal identifier, the ability to support storage and forwarding, and the first configuration information, determine whether the terminal is in a network accessible state, and determine the data retention period for on-board storage and forwarding and the data storage quota for on-board storage and forwarding based on the available satellite coverage time. Among them, the first configuration policy can be a pre-configured operator configuration policy, and the specific content of the first configuration policy can be that if the terminal supports the store-and-forward feature and the terminal reports the first configuration information, then the terminal is supported to send data to the satellite, and the satellite is supported to forward data for the terminal. Optionally, after receiving a network connection request sent by a terminal, the satellite can determine that the terminal is in a network accessible state based on the first configuration information reported by the terminal, the terminal identifier, the ability to support storage and forwarding, and the pre-configured first configuration policy. The MME in the satellite can determine the data retention period for on-board storage and forwarding based on the available satellite coverage time, and the MME in the satellite can determine the data storage quota for on-board storage and forwarding. Step 404: Return a first request acceptance response message to the terminal. The first request acceptance response message carries the data retention period of on-board storage and forwarding and the data storage quota of on-board storage and forwarding, and the target response message may be the first request acceptance response message. Optionally, the satellite may generate a first request acceptance response message based on the determined data retention period of on-board storage and forwarding and the data storage quota of on-board storage and forwarding. In an example, the first request acceptance response message may also carry a satellite identifier, a bearer session identifier (Bearer ID), etc. The satellite may return the first request acceptance response message to the terminal. In one example, if the satellite establishes a session based on the information reported by the terminal, the satellite may encapsulate the data storage quota of on-board store-and-forward into NAS information and return the NAS information to the terminal. In this embodiment, when the terminal supports store-and-forward and reports the first configuration information, the satellite can determine that the terminal is in a network-accessible state and return a first request acceptance response message to the terminal to quickly establish communication between the terminal and the satellite. In one embodiment, the communication method further includes: If the satellite covers the gateway and receives the data to be transmitted sent by the terminal that meets the data storage quota, the data to be transmitted will be forwarded. Optionally, if the satellite covers the gateway station, that is, if the satellite moves into the communication coverage of the gateway station, and the satellite receives the data to be transmitted sent by the terminal that meets the data storage quota, the satellite can forward the received data to be transmitted sent by the terminal to the ground network element. In this embodiment, if the terminal supports storage and forwarding, a first request acceptance response message can be returned to the terminal to quickly establish communication between the terminal and the satellite. If there is data to be forwarded corresponding to the terminal, the data can be forwarded directly to the ground network element to ensure the timeliness of data forwarding. In one embodiment, as shown in FIG5 , the step of “if the satellite covers the gateway and receives data to be transmitted from the terminal that meets the data storage quota, then forward the data to be transmitted” may include: Step 502: If the satellite covers the gateway and receives the data to be transmitted sent by the terminal that meets the data storage quota, a secondary authentication process is performed on the terminal. Optionally, if the satellite covers the gateway station, that is, if the satellite moves within the communication coverage of the gateway station, and the satellite receives the data to be transmitted sent by the terminal that meets the data storage quota, the satellite can perform a secondary authentication process on the terminal that has completed the verification. For example, the secondary authentication can be based on the first configuration information reported by the terminal, or the satellite can obtain the contract information corresponding to the terminal that has completed the verification through the ground network element, and perform authentication based on the contract information. In one example, when a satellite moves into the communication coverage area of a gateway, and receives data to be transmitted from the terminal that satisfies the data storage quota, and the terminal that has completed verification meets the secondary authentication conditions, the satellite can perform secondary authentication on the terminal that has completed verification. Step 504: If it is determined that the terminal passes the secondary authentication, the data to be transmitted is forwarded. Optionally, if the satellite determines that the secondary authentication of the terminal that has completed the verification has passed, the satellite may forward the data to be transmitted to the ground network element. In this embodiment, the terminal may be authenticated again to further improve the security of data transmission. In one embodiment, the network connection request carries a terminal identifier and a capability of supporting store-and-forwarding; optionally, the terminal identifier may be a terminal ID or an IMSI of the terminal. Accordingly, as shown in FIG6 , the step of “generating a target response message based on the network connection request and returning the target response message to the terminal” may include: Step 602: Based on the second configuration policy, the terminal identifier, and the ability to support store-and-forward, determine that the terminal is in a restricted transmission state, and determine the on-board store-and-forward data retention period and the on-board store-and-forward data storage quota based on the satellite coverage available time. The second configuration policy may be a pre-configured operator configuration policy. Specifically, if the terminal supports the store-and-forward feature, the terminal is determined to be in a limited transmission state, supporting the terminal to send limited data to the satellite. Optionally, after receiving a network connection request sent by a terminal, the satellite can determine that the terminal is in a restricted transmission state based on the terminal identification reported by the terminal, the ability to support storage and forwarding, and a pre-configured second configuration policy. The MME in the satellite can determine the data retention period for on-board storage and forwarding, and the data storage quota for on-board storage and forwarding based on the available satellite coverage time. Step 604: Return a second request acceptance response message to the terminal. The connection response message carries the data retention period of on-board storage and forwarding and the data storage quota of on-board storage and forwarding, and the target response message may be a second request acceptance response message. Optionally, the satellite may generate a second request acceptance response message based on the determined data retention period of on-board storage and forwarding and the data storage quota of on-board storage and forwarding. In an example, the second request acceptance response message may also carry a satellite identifier, a bearer session identifier (Bearer ID), etc. The satellite may return the second request acceptance response message to the terminal. In this embodiment, when the terminal supports store-and-forward, a second request acceptance response message may be returned to the terminal to quickly establish communication between the terminal and the satellite. In one embodiment, the communication method further includes: If the satellite covers the gateway, the terminal's contract information is obtained. If the terminal authentication is determined to be successful based on the contract information, and if the data to be transmitted sent by the terminal meets the data storage quota, the data to be transmitted is forwarded and the terminal's restricted transmission status is updated to an unrestricted transmission status. Optionally, if the satellite covers the gateway station, that is, if the satellite moves into the communication coverage of the gateway station, the satellite can obtain the contract information corresponding to the terminal in the restricted transmission state, and perform authentication based on the contract information of the terminal in the restricted transmission state; if the satellite determines that the authentication of the terminal in the restricted transmission state is passed, and the satellite receives the data to be transmitted sent by the terminal that meets the data storage quota, the satellite can forward the received data to be transmitted sent by the terminal to the ground network element; when the satellite determines that the authentication of the terminal is passed, the satellite updates the restricted transmission state of the terminal to an unrestricted transmission state. In this embodiment, if the terminal supports storage and forwarding, a second request acceptance response message can be returned to the terminal to quickly establish communication between the terminal and the satellite. After the satellite determines that the terminal authentication is passed, the terminal data is forwarded to the ground network element in a timely manner to ensure the reliability of data transmission. In one embodiment, after the step of updating the restricted transmission state of the terminal to the unrestricted transmission state, the communication method further includes: If it is detected that the terminal obtains satellite coverage, a status update message is sent to the terminal. Optionally, the status update message indicates that the restricted transmission status of the terminal is updated to the unrestricted transmission status; when the satellite determines that the authentication of the terminal is passed, the restricted transmission status of the terminal can be updated to the unrestricted transmission status; if the terminal moves into the communication coverage range of the satellite again, that is, the terminal obtains the coverage of the satellite, the satellite can send a status update message to the terminal, and after receiving the status update message, the terminal can determine that the status of the terminal has been updated from the restricted transmission state to the unrestricted transmission state. In this embodiment, when the terminal obtains satellite coverage again, a status update message may be promptly returned to the terminal. In one embodiment, the step of “generating a target response message based on the network connection request and returning the target response message to the terminal” may include: Based on the satellite being in the store-and-forward mode, the terminal meeting the initial satellite access conditions, and the terminal's ability to support store-and-forward, a request temporary storage response message is generated; and the request temporary storage response message is returned to the terminal. The attach suspend request response message (attach suspend) carries a satellite identifier, and the attach suspend request response message is used to prompt the terminal that the network connection request of the terminal is cached by the satellite. Optionally, the satellite can determine whether the terminal sending the network connection request supports the store-and-forward feature based on the store-and-forward capability carried in the network connection request; if the satellite is currently in store-and-forward mode, and the terminal sending the network connection request is a terminal accessing the satellite for the first time, the satellite can store the terminal identification and terminal capabilities of the terminal, and generate a request temporary storage response message, and return the request temporary storage response message to the terminal, indicating that the satellite has cached the network connection request sent by the terminal. Optionally, after receiving the temporary storage request response message sent by the satellite, the terminal may switch to a low-power mode, such as a power-saving mode. In one example, before switching to power-saving mode, the terminal may determine the next wake-up time based on the ephemeris information. After determining the next wake-up time, the terminal may switch to power-saving mode. After the current time reaches the next wake-up time, the terminal may exit power-saving mode and switch to normal operation. The ephemeris information may be a table of the precise position or trajectory of a celestial body over time, as a function of time. In one example, if the satellite covers the gateway, that is, if the feeder link between the satellite and the ground is available (Feeder link is available), the MME in the satellite can send a network connection request to the ground network element through the ground C-SCN-Ground, obtain the terminal's subscription information (authentication information) through the ground network element, and store the terminal's authentication information in the satellite. Optionally, after the terminal has coverage from the satellite, it can initiate another attach request, i.e., send the network connection request to the satellite. This network connection request carries the store-and-forward capability. If the MME in the satellite determines, based on the terminal's terminal identifier, that this is not a first-time access terminal, the satellite can authenticate the terminal based on locally stored authentication information and send a message to the terminal containing information required for the terminal to authenticate the network, completing bidirectional authentication. Furthermore, after the terminal has coverage from the satellite, it can establish an RRC connection with a satellite that matches the satellite identifier carried in the rejection response message. Based on this RRC connection, the terminal can initiate another attach request, i.e., send the network connection request to the satellite via the RRC connection. Upon receiving the network connection request, the satellite can perform bidirectional authentication based on the terminal identifier carried in the network connection request and the terminal's locally stored authentication information. Based on this, after the satellite determines that the terminal has passed authentication, the satellite can accept the network connection request sent by the terminal, determine the data retention period based on the satellite coverage available time, and determine the data storage quota corresponding to the terminal, generate a request acceptance response message based on the data retention period and the data storage quota, and return the request acceptance response message to the terminal. In this embodiment, by returning a request for temporary storage response message to the terminal through the satellite, reliable communication between the terminal device, the satellite and the ground network element can be achieved. The request for temporary storage response message prompts the terminal that the network request has been temporarily stored by the satellite, so that the terminal can promptly initiate a request to re-access the network when it is covered by the satellite in the subsequent process, thereby improving the flexibility of the terminal's access to the network. In one embodiment, the step of “generating a target response message based on the network connection request and returning the target response message to the terminal” may include: Based on the satellite being in the store-and-forward mode, the terminal meeting the initial satellite access condition, and the terminal's ability to support store-and-forward, a rejection response message is generated; and the rejection response message is returned to the terminal. The rejection response message carries a rejection reason message and a satellite identifier, and the request cache message indicates that the network connection request sent by the terminal is temporarily stored. Optionally, the satellite may determine whether the terminal sending the network connection request supports the store-and-forward feature based on the store-and-forward capability carried in the network connection request. If the satellite is currently in store-and-forward mode and the terminal sending the network connection request is accessing the satellite for the first time, the satellite may temporarily store the network connection request corresponding to the terminal, store the terminal identifier and terminal capabilities of the terminal, generate a rejection response message carrying a rejection reason message and the satellite identifier, and return the rejection response message to the terminal. The rejection reason message may indicate that the satellite has already cached the network connection request sent by the terminal. In one example, if the satellite covers the gateway, that is, if the feeder link between the satellite and the ground is available (Feeder link is available), the MME in the satellite can send a network connection request to the ground network element through the ground C-SCN-Ground, obtain the terminal's subscription information (authentication information) through the ground network element, and store the terminal's authentication information in the satellite. Optionally, after the terminal has coverage from the satellite, it can initiate another attach request, i.e., send the network connection request to the satellite. This network connection request carries the store-and-forward capability. If the MME in the satellite determines, based on the terminal's terminal identifier, that this is not a first-time access terminal, the satellite can authenticate the terminal based on locally stored authentication information and send a message to the terminal containing information required for the terminal to authenticate the network, completing bidirectional authentication. Furthermore, after the terminal has coverage from the satellite, it can establish an RRC connection with a satellite that matches the satellite identifier carried in the rejection response message. Based on this RRC connection, the terminal can initiate another attach request, i.e., send the network connection request to the satellite via the RRC connection. Upon receiving the network connection request, the satellite can perform bidirectional authentication based on the terminal identifier carried in the network connection request and the terminal's locally stored authentication information. Based on this, after the satellite determines that the terminal has passed authentication, the satellite can accept the network connection request sent by the terminal, determine the data retention period based on the satellite coverage available time, and determine the data storage quota corresponding to the terminal, generate a request acceptance response message based on the data retention period and the data storage quota, and return the request acceptance response message to the terminal. In this embodiment, through multiple requests between the terminal and the satellite, the terminal IoT device can register with the network through the satellite with on-board storage and forwarding characteristics, thereby realizing communication between the terminal device and the ground through the satellite and improving communication reliability. In one embodiment, the communication method further includes: Send a broadcast message. The broadcast message is used to instruct the terminal to connect to the satellite. Optionally, the satellite can send a broadcast message within the communication coverage of the satellite. After the terminal is turned on, it can search for the network and reside on it. After receiving the broadcast message sent by the satellite, it can parse the broadcast message and send a network connection request to the satellite. In one example, the broadcast message includes a store-and-forward feature and / or a satellite ID. The store-and-forward feature indicates that the satellite is in onboard store-and-forward mode, that is, a satellite capable of performing store-and-forward satellite operations (SandF Satellite Operation). For example, a base station or some core network elements can be deployed on the satellite, and a terminal establishes a service link with the satellite to transmit signaling or data. When the satellite moves to establish a feeder link with the ground, the signaling or data can be exchanged with the ground core network through a gateway. The satellite ID represents the identification of the satellite, for example, the satellite number, etc. In an example, the terminal may obtain the store-and-forward feature and the satellite ID carried by the broadcast message, the terminal may obtain the store-and-forward feature carried by the broadcast message, the terminal may obtain the satellite ID carried by the broadcast, and so on. In one embodiment, the target response message also carries the satellite return time. Optionally, the satellite return time may be the time when the satellite will next return. Based on the satellite return time carried in the target response message, the terminal may re-initiate a network connection request to the satellite upon reaching the satellite return time, or after an interval of the satellite return time. For example, the rejection response message may also carry the satellite return time, or the temporary storage request response message may also carry the satellite return time. In this embodiment, the terminal can accurately initiate a network connection request to the satellite in a timely manner after the satellite returns. The following describes in detail the specific implementation process of the above communication method in a specific application scenario in conjunction with specific embodiments. In one example, as shown in FIG7 , the terminal may request store-and-forward during the registration process. The MME / AMF may first suspend the request and, after the feeder link becomes available, obtain and store the subscription / authentication information of the terminal onboard. When the terminal initiates a registration request again, the MME / AMF may directly complete the authentication process. The following example uses the EPS architecture as an example, including user terminals (UE), satellite SAT and terrestrial network elements. The terrestrial network elements include SFMF and HSS / P-SW; the satellite includes evolved Node B (eNodeB), mobility management entity MME, SFCF and serving gateway S-GW / SCEF. Optionally, the functions of all network elements on the satellite may be deployed in a variety of ways, which may be new network elements or enhancements to existing network elements. Optionally, if it is 5GC, some of the AUSF authentication functions can also be configured on the satellite. As shown in Figure 7, the communication method may include the following steps: S0, UE receives the broadcast message of the satellite (UE receives the SIB of the SAT#1). Optionally, the UE powers on to search for a network and resides on it, and receives a broadcast message from the satellite eNB. The broadcast message carries a store-and-forward feature and / or a satellite ID. S1, UE sends a network connection request (attach request); optionally, when the UE needs to register with the network, it can send a network connection request to the onboard MME. Optionally, the network connection request can carry an indication of "supporting the store-and-forward feature". Optionally, if the UE indicates support for EPS Attach without PDN Connectivity, or SMS only, S6 and S7 can be skipped to achieve communication between the terminal and the satellite without establishing a bearer session; EPS Attach without PDN Connectivity, or SMS only, then steps 6 and 7 are skipped. S2, returns a rejection response message (attach reject). Optionally, the onboard MME can determine to temporarily store the UE's network connection request attach request based on the current satellite being in store-and-forward mode, the initial access of the terminal, and the terminal supporting the store-and-forward feature, and store the UE's terminal identifier (device identifier, IMSI) and its corresponding UE capabilities, and send a rejection response message (attach reject) to the UE. If the satellite has broadcast SandF mode (on-board store-and-forward mode), the rejection response message carries the rejection reason and the satellite ID. The rejection reason may be that the network connection request is cached; carrying the satellite ID makes it easier for the UE to find the satellite for registration next time; Optionally, the rejection response message may also carry the time when the satellite will return next time, so that the UE can apply for the same satellite again after the timer time; if the terminal finds another suitable target satellite before the timer time ends, the UE can send a network connection request to the target satellite. In step S3, the satellite reaches the gateway, indicating that the feeder link is available, and authentication / secutity processing is performed. Optionally, the MME can send the UE's network connection request to the HSS via the ground C-SCN-Ground, obtain the terminal's subscription information (authentication information), and send the UE's authentication information back to the satellite, where it is stored in the MME or other storage device. S4: When the terminal is within the communication coverage of the satellite, the terminal sends a network connection request (attach request) to the satellite again; optionally, when the UE has coverage, it establishes an RRC connection with the target satellite based on the satellite ID and initiates an attach request again, indicating that "store-and-forward feature is supported". Optionally, if the UE indicates support for EPS Attach without PDN Connectivity, or SMS only, S6 and S7 can be skipped to achieve communication between the terminal and the satellite without establishing a bearer session; EPS Attach without PDN Connectivity, or SMS only, S6 and S7 are skipped. S5: The MME completes two-way authentication (authentication / security) based on the UE's IMSI and the stored authentication information. S6. Optionally, the MME sends a Create session request to the SFCF, which in turn sends a Create session request to the S-GW / SCEF. That is, the MME establishes a bearer session with the SFCF, which in turn establishes a bearer session with the S-GW / SCEF. Optionally, the MME sends a Create Task request to establish the bearer. If Control Plane CIoT EPS Optimisation applies, the MME shall also indicate S11-U tunnelling of NAS user data and send its own S11-U IP address and MME DL TEID for DL data forwarding by the SGW. S7, optionally, the S-GW / SCEF sends a Create session response message to the SFCF, and the SFCF sends a Create session response message to the MME; optionally, the S-GW determines the on-board store-and-forward data storage quota (SandF data storage quota) based on the requested data counter and the on-board memory. S8. Determine the parameters of on-satellite storage and forwarding. Optionally, the MME accepts the network connection request; optionally, the MME may determine the data retention period of on-satellite storage and forwarding based on the available satellite coverage time, and encapsulate the data retention period of on-satellite storage and forwarding and the data storage quota of on-satellite storage and forwarding into the NAS information. S9, MME sends an Attach accept response (request acceptance response message) to the UE. Optionally, the request acceptance response message carries the satellite ID, SandF data retention period, SandF data storage quota, and Bearer ID (bearer ID), etc. In another example, for example, a terminal may request store-and-forward during the registration process. The MME / AMF may first suspend the request and, after a feeder link becomes available, obtain and store the terminal's subscription / authentication information onboard. When the terminal initiates a subsequent registration request, the MME / AMF may directly complete authentication. The following uses the EPS architecture as an example for illustration. The communication method may include the following steps: Step 0: The UE receives the satellite broadcast message (UE receives the SIB of the SAT#1). Optionally, the UE powers on to search for a network and resides on it, and receives a broadcast message from the satellite eNB. The broadcast message does not carry the satellite ID and the SandF mode. In step 10, the UE sends a network connection request (attach request). Optionally, if the UE needs to register with the network, it may send a network connection request to the onboard MME. Optionally, the network connection request may carry an indication of "support for store-and-forward features." Optionally, if the UE indicates support for EPS connection without a PDN session, or SMS only, steps 60 and 70 may be skipped to enable communication between the terminal and the satellite without establishing a bearer session. In the case of EPS Attach without PDN Connectivity, or SMS only, steps 60 and 70 are skipped. Step 20: Return a rejection response message (attach reject). Optionally, the onboard MME may determine to temporarily store the UE's network connection request attach request based on the current satellite being in store-and-forward mode, the initial access of the terminal, and the terminal supporting the store-and-forward feature, and store the UE's terminal identifier (device identifier, IMSI) and its corresponding UE capabilities, and send a rejection response message (attach reject) to the UE. If the UE supports on-board store-and-forward, a rejection response message is sent to the UE. The rejection response message carries the rejection reason and the satellite ID. The rejection reason may be the S&F feature mode and the attach request is cached (the network connection request is cached). Carrying the satellite ID can facilitate the UE to find the satellite for registration next time. If the UE does not support on-board store-and-forward, the satellite directly sends a rejection response message to the terminal. That is, if the UE does not support S&F, it is directly rejected. In step 30, the satellite reaches the gateway, indicating that the feeder link is available, and authentication / secutity processing is performed. Optionally, the MME can send the UE's network connection request to the ground network element (for example, to the HSS via the SFMF), obtain the terminal's subscription information (authentication information), and send the UE's authentication information back to the satellite, which is stored in the MME or other storage device. In step 40, when the terminal is within the communication coverage of the satellite, the terminal sends a network connection request (attach request) to the satellite again; optionally, when the UE has coverage, it establishes an RRC connection with the target satellite based on the satellite ID and initiates an attach request again, indicating that "store-and-forward feature is supported". Optionally, if the UE indicates support for EPS Attach without PDN Connectivity, or SMS only, steps 60 and 70 may be skipped to enable communication between the terminal and the satellite without establishing a bearer session; EPS Attach without PDN Connectivity, or SMS only, then steps 60 and 70 may be skipped. In step 50, if the MME determines based on the device identifier IMSI that the terminal is the IMSI of the terminal requested previously, the MME can authenticate and authorize the terminal based on the subscription information obtained in step 30; and send the information required by the UE authentication network to the UE to complete two-way authentication. Step 60: Optionally, the MME sends a Create session request to the SFCF, which in turn sends a Create session request to the S-GW / SCEF. That is, the MME establishes a bearer session with the SFCF, which in turn establishes a bearer session with the S-GW / SCEF. Optionally, the MME sends a Create Task request to establish the bearer. If Control Plane CIoT EPS Optimisation applies, the MME shall also indicate S11-U tunnelling of NAS user data and send its own S11-U IP address and MME DL TEID for DL data forwarding by the SGW. Step 70, optionally, the S-GW / SCEF sends a Create session response message (Create session response) to the SFCF, and the SFCF sends a Create session response message (Create session response) to the MME; optionally, the S-GW determines the on-board store-and-forward data storage quota (SandF data storage quota) based on the requested data counter and the on-board memory. Step 80, determine the parameters of the on-board storage and forwarding (Determines the SandF the parameters); optionally, the MME accepts the network connection request; optionally, the MME can determine the data retention period of the on-board storage and forwarding based on the satellite coverage available time, and encapsulate the data retention period of the on-board storage and forwarding and the data storage quota of the on-board storage and forwarding into the NAS information. Step 90: The MME sends an Attach accept response (request acceptance response message) to the UE. Optionally, the request acceptance response message carries the satellite ID, SandF data retention period, SandF data storage quota, and Bearer ID (bearer ID). In another example, for example, a terminal network access process with an attach suspend request may be introduced. The following is an example of application to an EPS architecture. The communication method may include the following steps: In step 0, the UE receives a broadcast message from the satellite (UE receives the SIB of the SAT#1). Optionally, the UE powers on, searches for a network, and resides on it, and receives a broadcast message from the satellite eNB. The broadcast message carries a store-and-forward feature and / or a satellite ID. Step 1: The UE sends a network connection request (attach request); optionally, when the UE needs to register with the network, it may send a network connection request to the onboard MME. Optionally, the network connection request may carry an indication of "supporting the store-and-forward feature". Optionally, if the UE indicates support for EPS Attach without PDN Connectivity, or SMS only, S6 and S7 can be skipped to achieve communication between the terminal and the satellite without establishing a bearer session; EPS Attach without PDN Connectivity, or SMS only, S6 and S7 are skipped. Step 2: Return a request for temporary storage response message (attach suspend). Optionally, the onboard MME may determine to temporarily store the UE's network connection request for attach request based on the current satellite being in store-and-forward mode, the initial access of the terminal, and the terminal supporting the store-and-forward feature, store the UE's terminal identifier (device identifier, IMSI) and its corresponding UE capabilities, and send a request for caching response message (attach suspend) to the UE, indicating that the attach request is cached. The request for caching response message may also carry the satellite ID so that the UE can find the satellite for registration next time. Optionally, the rejection response message may also carry the time when the satellite will return next time, so that the UE can apply for the same satellite again after the timer time; if the terminal finds another suitable target satellite before the timer time ends, the UE can send a network connection request to the target satellite. Optionally, after receiving the temporary storage request response message sent by the satellite, the terminal may switch to a low-power mode, such as a power-saving mode. In one example, before switching to power-saving mode, the terminal may determine the next wake-up time based on the ephemeris information. After determining the next wake-up time, the terminal may switch to power-saving mode. After the current time reaches the next wake-up time, the terminal may exit power-saving mode and switch to normal operation. The ephemeris information may be a table of the precise position or trajectory of a celestial body over time, as a function of time. In step 3, the satellite reaches the gateway, indicating that the feeder link is available, and authentication / secutity processing is performed. Optionally, the MME can obtain the terminal's subscription information (authentication information) by passing the UE's network connection request through the ground network element. The MME then sends the UE's authentication information back to the satellite and stores it in the MME or other storage device. For example, obtaining the authentication information can be done by sending it to the HSS via the SFMF. In step 4, when the terminal is within the communication coverage of the satellite, the terminal can establish an RRC connection with the target satellite based on the satellite ID and initiate a network connection request (attach request) again. The network connection request carries identification information indicating that the "store and forward feature is supported". The implementation process of step 5 to step 9 is the same as the implementation process of S5-S9 provided in the above embodiment, and will not be repeated here. In another example, for example, a terminal network access process with an attach suspend request may be introduced. The following is an example of application to an EPS architecture. The communication method may include the following steps: Step 0: The UE receives the satellite broadcast message (UE receives the SIB of the SAT#1). Optionally, the UE powers on to search for a network and resides on it, and receives a broadcast message from the satellite eNB. The broadcast message does not carry the satellite ID and the SandF mode. Step 1: The UE sends a network connection request (attach request). Optionally, if the UE needs to register with the network, it may send a network connection request to the onboard MME. Optionally, the network connection request may carry an indication of "support for store-and-forward features." Optionally, if the UE indicates support for EPS connection without a PDN session, or SMS only, steps 6 and 7 may be skipped to enable communication between the terminal and the satellite without establishing a bearer session. For EPS Attach without PDN Connectivity, or SMS only, steps 6 and 7 are skipped. Step 2: Return a request for temporary storage response message (attach suspend). Optionally, the onboard MME may determine to temporarily store the UE's network connection request for attach request based on the current satellite being in store-and-forward mode, the terminal being the initial access, and the terminal supporting the store-and-forward feature, and store the UE's terminal identifier (device identifier, IMSI) and its corresponding UE capabilities. Then, the MME sends a request for temporary storage response message (attach suspend) to the UE, indicating that the attach request is cached. The request for temporary storage response message may also carry the satellite ID so that the UE can find the satellite for registration next time. Optionally, the rejection response message may also carry the time when the satellite will return next time, so that the UE can apply for the same satellite again after the timer time; if the terminal finds another suitable target satellite before the timer time ends, the UE can send a network connection request to the target satellite. Optionally, after receiving the temporary storage request response message sent by the satellite, the terminal may switch to a low-power mode, such as a power-saving mode. In one example, before switching to power-saving mode, the terminal may determine the next wake-up time based on the ephemeris information. After determining the next wake-up time, the terminal may switch to power-saving mode. After the current time reaches the next wake-up time, the terminal may exit power-saving mode and switch to normal operation. The ephemeris information may be a table of the precise position or trajectory of a celestial body over time, as a function of time. The implementation process of steps 3 to 9 is the same as the implementation process of steps 30 to 90 provided in the above embodiment, and will not be repeated here. In another example, as shown in Figure 8, for example, restricted transmission can be used: the terminal requests store-and-forward during the registration process. Based on the reported store-and-forward feature, the MME / AMF directly accepts the UE request and indicates that the UE is in a restricted state and can send restricted data. After the feeder link is available, if necessary, the onboard equipment sends the UE request to the ground, such as the UDM / SMSF. If authentication is successful, the data is sent. The following EPS is used as an example to illustrate, including the user terminal (UE), the satellite SAT, and the ground network elements. The ground network elements include the SFMF, HSS / P-SW, and the SandF server (S&F server); the satellite includes the evolved Node B (eNodeB), the mobility management entity MME, the SFCF, and the serving gateway S-GW / SCEF. Optionally, if it is 5GC, some of the AUSF authentication functions can also be configured on the satellite. The communication method may include the following steps: In step 0, the UE receives a broadcast message from the satellite (UE receives the SIB of the SAT#1). Optionally, the UE powers on, searches for a network, and resides on it, and receives a broadcast message from the satellite eNB. The broadcast message carries a store-and-forward feature and / or a satellite ID. Step 1: The UE sends a network connection request (attach request); optionally, when the UE wants to transmit information through the network, it can send a network connection request to the onboard MME. Optionally, the network connection request can carry a terminal identifier (IMSI) and indicate "support for store-and-forward feature". Optionally, if the UE indicates support for EPS Attach without PDN Connectivity, or SMS only, S3 and S4 can be skipped to achieve communication between the terminal and the satellite without establishing a bearer session; EPS Attach without PDN Connectivity, or SMS only, then steps 3 and 4 are skipped. Step 2: Determine the UE's state. Optionally, since the satellite does not have the UE's subscription and / or security information locally, the MME on the satellite can determine, based on the IMSI reported by the UE, "support for store-and-forward features," and the operator's configuration policy (second configuration policy), that the UE can be in a limited transmission state, i.e., the satellite supports the UE to send limited data. Optionally, after the MME locally stores information such as the terminal identification and terminal capabilities of the terminal, if the feeder connection is available, that is, after the feeder link is connected, the UE can obtain subscription and / or security information from the ground network element such as HSS, and the satellite can update the restricted transmission state of the UE to the unrestricted transmission state. If the UE indicates support for EPS Attach without PDN Connectivity, or SMS only, S3 and S4 can be skipped to achieve communication between the terminal and the satellite without establishing a bearer session; EPS Attach without PDN Connectivity, or SMS only, then steps 3 and 4 are skipped. Step 3. Optionally, the MME sends a Create session request to the SFCF, which in turn sends a Create session request to the S-GW / SCEF. That is, the MME establishes a bearer session with the SFCF, which in turn establishes a bearer session with the S-GW / SCEF. Optionally, the MME sends a Create Task request to establish the bearer. If Control Plane CIoT EPS Optimisation applies, the MME shall also indicate S11-U tunnelling of NAS user data and send its own S11-U IP address and MME DL TEID for DL data forwarding by the SGW. Step 4. Optionally, the S-GW / SCEF sends a Create session response message to the SFCF, and the SFCF sends a Create session response message to the MME; optionally, the S-GW determines the on-board store-and-forward data storage quota (SandF data storage quota) based on the requested data counter and the on-board memory. Step 5. Determine the parameters of on-board storage and forwarding (Determines the SandF the parameters); optionally, the MME can determine the data retention period of on-board storage and forwarding SandF based on the available satellite coverage time (this parameter can also be the unavailability period duration, Unavailability Period Duration); optionally, if the UE is determined to be in a limited state, the MME determines the data storage quota SandF data storage that the UE can transmit, and the data storage quota can be the number of data items that the satellite allows the terminal to send and the size of each data item. Step 6: The MME sends an Attach accept response to the UE. Optionally, the Attach accept response carries the satellite ID, SandF data retention period, SandF data storage quota, and Bearer ID. Step 7: Send uplink data (first uplink data). Optionally, if the UE needs to transmit urgent data, the terminal can send quota-satisfying data to the onboard device (MME or S-GW if a session is established, or a new network element device). The onboard device associates the data with the UE's IMSI and stores it. Step 8: Identity verification. Optionally, if the satellite covers the gateway, that is, the feeder link is available, for terminals in the restricted transmission state, the MME can send the UE's request to the HSS through the ground network element, obtain the terminal's subscription information and / or security information, and return it to the MME. If the verification is successful, the MME can remove the UE's limited state restriction. If the UE regains coverage of the satellite, the satellite can return the status update to the UE. Step 9: Optionally, the onboard device forwards the received UE data to the ground. In another example, as shown in FIG9 , for example, direct transmission may be used: the terminal sends security information and the like to the network in the registration process request, and the MME / AMF directly accepts the UE request based on the reported information and UE capabilities. If necessary, the onboard device sends the UE request to the ground, such as UDM / SMSF. If the authentication is successful, the data is sent. The following uses EPS as an example to illustrate the system, which includes user terminals (UEs), satellite SATs, and terrestrial network elements. The terrestrial network elements include SFMF, HSS / P-SW, and SandF server; the satellite includes evolved Node B (eNodeB), mobility management entity MME, SFCF, and serving gateway S-GW / SCEF. Optionally, if it is 5GC, some of the AUSF authentication functions can also be configured on the satellite. The communication method may include the following steps: In step 0, the UE receives a broadcast message from the satellite (UE receives the SIB of the SAT#1). Optionally, the UE powers on, searches for a network, and resides on it, and receives a broadcast message from the satellite eNB. The broadcast message carries a store-and-forward feature and / or a satellite ID. Step 1: The UE sends a network connection request (attach request); optionally, when the UE wants to transmit information through the network, it can send a network connection request to the onboard MME. Optionally, the network connection request can carry a terminal identifier (IMSI), an indication of "support for store-and-forward feature" and terminal information. Optionally, if the UE indicates support for EPS Attach without PDN Connectivity, or SMS only, S3 and S4 can be skipped to achieve communication between the terminal and the satellite without establishing a bearer session; EPS Attach without PDN Connectivity, or SMS only, then steps 3 and 4 are skipped. Step 2: Identity authentication. Optionally, the MME can authenticate the terminal based on the IMSI reported by the UE, the "support for store-and-forward feature," the first configuration policy, and the first configuration information reported by the terminal. For example, it can determine whether the terminal can access the network. Optionally, if the UE indicates support for EPS Attach without PDN Connectivity, or SMS only, steps 9 and 10 can be skipped, and communication between the terminal and the satellite can be achieved without establishing a bearer session. If EPS Attach without PDN Connectivity, or SMS only is indicated, steps 3 and 4 are skipped. Optionally, if the UE indicates support for EPS Attach without PDN Connectivity, or SMS only, S3 and S4 can be skipped to achieve communication between the terminal and the satellite without establishing a bearer session; EPS Attach without PDN Connectivity, or SMS only, then steps 3 and 4 are skipped. Step 3. Optionally, the MME sends a Create session request to the SFCF, which in turn sends a Create session request to the S-GW / SCEF. That is, the MME establishes a bearer session with the SFCF, which in turn establishes a bearer session with the S-GW / SCEF. Optionally, the MME sends a Create Task request to establish the bearer. If Control Plane CIoT EPS Optimisation applies, the MME shall also indicate S11-U tunnelling of NAS user data and send its own S11-U IP address and MME DL TEID for DL data forwarding by the SGW. Step 4. Optionally, the S-GW / SCEF sends a Create session response message to the SFCF, and the SFCF sends a Create session response message to the MME; optionally, the S-GW determines the on-board store-and-forward data storage quota (SandF data storage quota) based on the requested data counter and the on-board memory. Step 5. Determine the parameters of the on-board storage and forwarding (Determines the SandF the parameters); optionally, the MME can determine the on-board storage and forwarding data retention period SandF based on the satellite coverage availability time (this parameter can also be the unavailability period duration, Unavailability Period Duration); optionally, if the UE reports the information and establishes a session, the on-board storage and forwarding data retention period and the on-board storage and forwarding data storage quota are encapsulated into the NAS information. Step 6: The MME sends an Attach accept response to the UE. Optionally, the Attach accept response carries the satellite ID, SandF data retention period, SandF data storage quota, and Bearer ID. Step 7: Send uplink data (first uplink data). Optionally, if the UE needs to transmit urgent data, the terminal can send quota-satisfying data to the onboard device (MME or S-GW if a session is established, or a new network element device). The onboard device associates the data with the UE's IMSI and stores it. Step 8, identity authentication; optionally, the satellite covers the gateway station, that is, the feeder link is available (Feeder link is available). If secondary authentication is required, the secondary authentication is performed on the UE that has completed the authentication, otherwise step 8 can be skipped. Step 9: Optionally, the onboard device forwards the received UE data to the ground. The communication method provided in the embodiments of the present application enables terminal IoT devices to register with the network through satellites with onboard storage and forwarding features, allowing devices even in remote areas to connect to the network and send data, providing effective communication guarantees for scientific research, government and other institutions, and providing strong support for the vision of ubiquitous communication. It should be understood that, although the steps in the flowcharts of the above embodiments are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts of the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily to be performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of steps or stages in other steps. Based on the same inventive concept, the embodiments of the present application further provide a communication device for implementing the aforementioned communication method. The implementation solution provided by the device is similar to the implementation solution described in the aforementioned method. Therefore, the specific limitations in the one or more communication device embodiments provided below can be found in the above-mentioned limitations on the communication method and will not be repeated here. In one embodiment, as shown in FIG10 , a communication device 1000 is provided, which is applied to a terminal and includes: A first sending unit 1002 is configured to send a network connection request to the satellite, where the network connection request is used to instruct the terminal to establish a network connection with the satellite; The first receiving unit 1004 is configured to receive a target response message returned by the device on the satellite to the terminal. In some embodiments, the network connection request includes a capability of supporting store-and-forward and a terminal identifier. In some embodiments, the first receiving unit is specifically configured to: The first request acceptance response message returned by the device on the receiving satellite to the terminal carries the data retention period of on-board storage and forwarding and the data storage quota of on-board storage and forwarding. The first request acceptance response message is generated by the satellite after determining that the terminal is in a network accessible state based on the terminal identification and the ability to support storage and forwarding. In some embodiments, the network connection request includes a capability of supporting store-and-forward and a terminal identifier; and the first receiving unit is specifically configured to: Receive a second request acceptance response message returned by the device on the satellite to the terminal. The second request acceptance response message carries the data retention period of on-board storage and forwarding and the data storage quota of on-board storage and forwarding. The second request acceptance response message is generated by the satellite after determining that the terminal is in a restricted transmission state based on the second configuration policy, the terminal identifier, and the ability to support storage and forwarding. In some embodiments, the network connection request includes a capability of supporting store-and-forward; and the first receiving unit is specifically configured to: The device on the receiving satellite returns a request for temporary storage response message to the terminal. The request for temporary storage response message is generated by the device on the satellite based on the satellite being in store-and-forward mode, the terminal meeting the conditions for initial satellite access, and the terminal's ability to support store-and-forward; the request for temporary storage response message carries a satellite identifier. In some embodiments, the network connection request includes a capability of supporting store-and-forward; and the first receiving unit is specifically configured to: The device on the receiving satellite returns a rejection response message to the terminal. The rejection response message is generated by the device on the satellite based on the satellite being in store-and-forward mode, the terminal meeting the conditions for initial satellite access, and the terminal's ability to support store-and-forward. The rejection response message carries a rejection reason message and a satellite identifier. In some embodiments, the first receiving unit is further configured to: Receive satellite broadcast messages. In some embodiments, the first sending unit is further configured to: Sends data to the satellite to be transmitted that satisfies the data storage quota. In one embodiment, as shown in FIG11 , a communication device 1100 is provided, which is applied to a satellite and includes: The second receiving unit 1102 is configured to receive a network connection request sent by a terminal, where the network connection request is used to instruct the terminal to establish a network connection with a satellite; The second sending unit 1104 is configured to generate a target response message based on the network connection request, and return the target response message to the terminal. In some embodiments, the network connection request carries a terminal identifier and supports store-and-forward capabilities. In some embodiments, the second sending unit is specifically configured to Based on the terminal identification and the ability to support store-and-forward, determine whether the terminal is in a network-accessible state, and determine the on-board store-and-forward data retention period and the on-board store-and-forward data storage quota based on the available satellite coverage time; A first request acceptance response message is returned to the terminal, where the first request acceptance response message carries the data retention period for on-board storage and forwarding and the data storage quota for on-board storage and forwarding. In some embodiments, the apparatus further comprises: The forwarding unit is configured to forward the data to be transmitted if the satellite covers the gateway station and receives the data to be transmitted sent by the terminal that meets the data storage quota. In some embodiments, the forwarding unit is specifically configured to: If the satellite covers the gateway and receives data to be transmitted from the terminal that meets the data storage quota, the terminal will be authenticated again; If it is determined that the terminal passes the secondary authentication, the data to be transmitted is forwarded. In some embodiments, the network connection request carries the terminal identification and the ability to support store-and-forward, and the second sending unit is specifically configured to Determining that the terminal is in a restricted transmission state based on the second configuration policy, the terminal identifier, and the ability to support store-and-forward, and determining a data retention period for on-board store-and-forward and a data storage quota for on-board store-and-forward based on the satellite coverage available time; A second request acceptance response message is returned to the terminal, where the second request acceptance response message carries the data retention period of on-board storage and forwarding and the data storage quota of on-board storage and forwarding. In some embodiments, the forwarding unit is further configured to: If the satellite covers the gateway, the terminal's contract information is obtained; if the terminal authentication is determined to be successful based on the contract information, and if the data to be transmitted sent by the terminal meets the data storage quota, the data to be transmitted is forwarded and the terminal's restricted transmission status is updated to an unrestricted transmission status. In some embodiments, the apparatus further comprises: The updating unit is configured to send a status update message to the terminal if it is detected that the terminal obtains satellite coverage, wherein the status update message indicates that the restricted transmission state of the terminal is updated to the unrestricted transmission state. In some embodiments, the second sending unit is specifically configured to Generate a temporary storage request response message based on the satellite being in store-and-forward mode, the terminal meeting the initial satellite access conditions, and the terminal's ability to support store-and-forward; A temporary storage request response message is returned to the terminal, where the temporary storage request response message carries a satellite identifier. In some embodiments, the second sending unit is specifically configured to: generating a rejection response message based on the satellite being in store-and-forward mode, the terminal meeting the initial satellite access conditions, and the terminal's ability to support store-and-forward; A rejection response message is returned to the terminal, where the rejection response message carries the rejection reason message and the satellite identifier. In some embodiments, the second sending unit is further configured to: Send a broadcast message, which is used to instruct the terminal to connect to the satellite. It should be noted that the division of units in the embodiments of the present application is schematic and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a processor-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the relevant technology, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the methods of various embodiments of the present application. It should be noted here that the above-mentioned device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as those in the method embodiment will not be described in detail here. In an exemplary embodiment, a communication device is provided, which may be a terminal device or a network device, and its internal structure may be as shown in Figure 12. The communication device includes a memory, a transceiver, and a processor. A transceiver is used to receive and send data under the control of the processor. In FIG12 , the bus architecture may include any number of interconnected buses and bridges, specifically various circuits linked together by one or more processors represented by a processor and a memory represented by a memory. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver may be a plurality of components, i.e., a transmitter and a receiver, providing a unit for communicating with various other devices over a transmission medium, such as a wireless channel, a wired channel, an optical cable, or the like. The processor is responsible for managing the bus architecture and general processing, and the memory may store data used by the processor when performing operations. The processor can be a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or a complex programmable logic device (CPLD), and the processor can also adopt a multi-core architecture. The processor calls the program stored in the memory to execute any method provided in the embodiments of the present application according to the obtained executable instructions. The processor and the memory can also be arranged physically separately. It should be noted here that the above-mentioned device provided in the embodiment of the present disclosure can implement all the method steps implemented in the above-mentioned method embodiment and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as those in the method embodiment will not be described in detail here. The physical device corresponding to the terminal device or network device is shown in Figure 12, which can implement all the method steps implemented by the method embodiment on the terminal device or network device side, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here. It should be noted here that the above-mentioned device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as those in the method embodiment will not be described in detail here. In an exemplary embodiment, a network device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps in the above method embodiments when executing the computer program. In one embodiment, a processor-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented. In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor. The processor-readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO)), optical storage (such as CDs, DVDs, BDs, HVDs, etc.), and semiconductor storage (such as ROMs, EPROMs, EEPROMs, non-volatile memories (NAND FLASH), solid-state drives (SSDs)), etc. Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) that contain computer-usable program code. The present application is described with reference to the flowchart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, and the combination of the process and / or box in the flowchart and / or block diagram can be implemented by computer-executable instructions. These computer-executable instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processing machine or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the function specified in one process or multiple processes in the flowchart and / or one box or multiple boxes in the block diagram. These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the processor-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram. Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that it is still possible to modify the technical solutions described in the aforementioned embodiments, or to replace some or all of the technical features therein with equivalents; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A communication method, applied to a terminal, comprising: Sending a network connection request to the satellite, where the network connection request is used for the terminal to establish a network connection with the satellite; A target response message is received, which is returned by the device on the satellite to the terminal.

2. The method according to claim 1, wherein The network connection request includes a capability of supporting store-and-forward and a terminal identifier.

3. The method according to claim 2, wherein: The receiving a target response message returned by the device on the satellite to the terminal includes: Receive a first request acceptance response message returned by the device on the satellite to the terminal, where the first request acceptance response message carries the data retention period of the on-board storage and forwarding and the data storage quota of the on-board storage and forwarding. The first request acceptance response message is generated by the satellite after determining that the terminal is in a network accessible state based on the terminal identifier and the capability to support storage and forwarding.

4. The method according to claim 1, wherein The network connection request includes a capability of supporting store-and-forward and a terminal identifier; and the receiving a target response message returned by the device on the satellite to the terminal includes: Receive a second request acceptance response message returned by the device on the satellite to the terminal, where the second request acceptance response message carries the data retention period of the on-board storage and forwarding and the data storage quota of the on-board storage and forwarding. The second request acceptance response message is generated by the satellite after determining that the terminal is in a restricted transmission state based on a second configuration policy, the terminal identifier, and the capability of supporting storage and forwarding.

5. The method according to claim 1, wherein The network connection request includes a capability of supporting store-and-forward; and the receiving a target response message returned by the device on the satellite to the terminal includes: receiving a temporary storage request response message returned by the device on the satellite to the terminal, where the temporary storage request response message is generated by the device on the satellite based on the satellite being in a store-and-forward mode, the terminal meeting a condition for initial satellite access, and the terminal having a store-and-forward support capability; and the temporary storage request response message carries a satellite identifier.

6. The method according to claim 1, wherein The network connection request includes a capability of supporting store-and-forward; and the receiving a target response message returned by the device on the satellite to the terminal includes: receiving a rejection response message returned by the device on the satellite to the terminal, where the rejection response message is generated by the device on the satellite based on the satellite being in store-and-forward mode, the terminal meeting a condition for initial satellite access, and the terminal having a store-and-forward support capability; and the rejection response message carries a rejection reason message and a satellite identifier.

7. The method according to any one of claims 1 to 4, wherein: The target response message also carries a satellite identifier and a bearer session identifier.

8. The method according to claim 5 or 6, wherein: The target response message also carries the satellite return time.

9. The method according to claim 1, wherein Before the step of sending a network connection request to the satellite, the method further includes: Receive satellite broadcast messages.

10. The method according to claim 9, wherein: The satellite broadcast message carries a store-and-forward feature and / or a satellite identifier.

11. The method according to claim 3 or 4, further comprising: Sending to the satellite the data to be transmitted that satisfies the data storage quota.

12. A communication method, applied to a satellite, comprising: receiving a network connection request sent by a terminal, where the network connection request is used to instruct the terminal to establish a network connection with the satellite; A target response message is generated based on the network connection request, and the target response message is returned to the terminal.

13. The method according to claim 12, wherein: The network connection request carries a terminal identifier and supports a store-and-forward capability.

14. The method according to claim 13, wherein The generating a target response message based on the network connection request and returning the target response message to the terminal includes: Determining, based on the terminal identification and the ability to support store-and-forward, whether the terminal is in a network-accessible state, and determining, based on the satellite coverage availability time, a data retention period for on-board store-and-forward and a data storage quota for on-board store-and-forward; A first request acceptance response message is returned to the terminal, where the first request acceptance response message carries the data retention period of the on-board store-and-forward and the data storage quota of the on-board store-and-forward.

15. The method according to claim 13, further comprising: If the satellite covers the gateway and receives the data to be transmitted sent by the terminal that meets the data storage quota, the satellite forwards the data to be transmitted.

16. The method according to claim 15, wherein If the satellite covers the gateway and receives the data to be transmitted sent by the terminal that meets the data storage quota, forwarding the data to be transmitted includes: If the satellite covers the gateway and receives the data to be transmitted sent by the terminal that meets the data storage quota, then authenticate the terminal; If it is determined that the terminal passes the authentication, the data to be transmitted is forwarded.

17. The method according to claim 12, wherein: The network connection request carries a terminal identifier and a store-and-forward capability, and the generating a target response message based on the network connection request and returning the target response message to the terminal includes: Determining, based on the second configuration policy, the terminal identifier, and the ability to support store-and-forward, that the terminal is in a restricted transmission state, and determining, based on the satellite coverage available time, a data retention period for on-board store-and-forward and a data storage quota for on-board store-and-forward; A second request acceptance response message is returned to the terminal, where the second request acceptance response message carries the data retention period of the on-board store-and-forward and the data storage quota of the on-board store-and-forward.

18. The method according to claim 17, further comprising: If the satellite covers the gateway, acquiring the contract information of the terminal; If it is determined based on the contract information that the terminal authentication is passed, and the data to be transmitted that meets the data storage quota is received from the terminal, the data to be transmitted is forwarded, and the restricted transmission state of the terminal is updated to the unrestricted transmission state.

19. The method according to claim 18, further comprising: If it is detected that the terminal obtains coverage of the satellite, a status update message is sent to the terminal, where the status update message indicates that the restricted transmission state of the terminal is updated to the unrestricted transmission state.

20. The method according to claim 13 or 17, wherein The target response message also carries a satellite identifier and a bearer session identifier.

21. The method according to claim 12, wherein The generating a target response message based on the network connection request and returning the target response message to the terminal includes: generating a temporary storage request response message based on the satellite being in a store-and-forward mode, the terminal meeting a condition for initial satellite access, and the terminal having a store-and-forward support capability; The temporary storage request response message is returned to the terminal, where the temporary storage request response message carries a satellite identifier.

22. The method according to claim 12, wherein The generating a target response message based on the network connection request and returning the target response message to the terminal includes: generating a rejection response message based on the satellite being in a store-and-forward mode, the terminal meeting a condition for initial satellite access, and the terminal having a store-and-forward support capability; The rejection response message is returned to the terminal, where the rejection response message carries a rejection reason message and a satellite identifier.

23. The method of claim 12, further comprising: A broadcast message is sent, where the broadcast message is used to instruct the terminal to connect to the satellite.

24. The method according to claim 23, wherein The broadcast message includes a store-and-forward feature and / or a satellite identification.

25. The method according to claim 21 or 22, wherein The target response message also carries the satellite return time.

26. A communication device, applied to a terminal, comprising: A first sending unit, configured to send a network connection request to a satellite, wherein the network connection request is used to instruct the terminal to establish a network connection with the satellite; The first receiving unit is configured to receive a target response message returned by the device on the satellite to the terminal.

27. A communication device, applied to a satellite, comprising: a second receiving unit, configured to receive a network connection request sent by a terminal, wherein the network connection request is used to instruct the terminal to establish a network connection with the satellite; The second sending unit is configured to generate a target response message based on the network connection request and return the target response message to the terminal.

28. A communication device comprising a memory, a transceiver, and a processor: Memory for storing computer programs; a transceiver, configured to transmit and receive data under the control of the processor; A processor, configured to read the computer program in the memory and execute the method according to any one of claims 1 to 25.

29. A computer-readable storage medium having a computer program stored thereon, wherein: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 25 are implemented.

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