Satellite communication method and device and satellite

Abstract

The embodiment of the invention provides a satellite communication method, a satellite communication device and a satellite, a reestablishment request message sent by a terminal can be received, and the reestablishment request message is a message sent to a target satellite based on a target beam after the terminal detects that the connection of a wireless link of the terminal fails and suspends a terminal side RLC (Radio Link Control). And hanging a satellite side RLC for the terminal, acquiring context information of service transmission of the terminal on the source beam according to the terminal identifier and the source beam identifier, and synchronizing the context information to the target beam. And recovering the satellite side RLC for the terminal, and sending a service recovery message to the terminal, the service recovery message being used for indicating the terminal to recover the terminal side RLC, and recovering service transmission at the target beam, so as to reduce service data loss caused by switching the source beam to the target beam, and improve user experience.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a satellite communication method, device and satellite. Background Art

[0002] For ground communication systems, service continuity is achieved through cell switching. For satellite communication systems, the speed of satellite movement relative to the ground is very fast, and the terminal needs to frequently switch between intra-satellite beams and between satellites. Each beam switching will result in the loss of service data, making it difficult to ensure the continuity of service data for inter-beam switching of the Internet of Things or low-speed data terminals. At the same time, the terminal needs to continuously measure the adjacent beam signal, report the measurement report, and frequently report the location information. The access network side then switches between beams based on the terminal location information and the neighboring area measurement information. However, due to the low processing power of the Internet of Things or low-speed data terminals, and strict requirements on power consumption. Therefore, the Internet of Things or low-speed data terminals should not continuously measure adjacent beam signals, report measurement reports, or frequently report location information. And some terminals do not even have a GNSS (Global Navigation Satellite System) module, that is, the access network side lacks the necessary input information and cannot make an effective switching decision. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide a satellite communication method, device and satellite, so as to solve the problem of service data interruption that may occur during beam switching when the satellite is in a high-speed moving state. The specific technical solution is as follows:

[0004] In a first aspect of an embodiment of the present invention, a satellite communication method applied to a terminal is provided, the method comprising:

[0005] The terminal detects that its own wireless link connection fails, suspends the terminal side wireless link control layer protocol RLC, and then sends a first message to the target satellite based on the target beam; the first message carries the terminal identifier and the source beam identifier; the source beam is the beam used by the terminal to transmit service data before the terminal side RLC is suspended.

[0006] Optionally, the first message is a reconstruction request message.

[0007] Optionally, the method further includes: receiving a service recovery message sent by the target satellite, restoring the terminal side RLC according to the service recovery message, and restoring service transmission in the target beam.

[0008] Optionally, the step of suspending the RLC on the terminal side includes one or more of the following:

[0009] Keep the current RLC SDU, keep the current RLC SDU segment, keep the current RLC PDU, maintain the current state variable value, keep the current value of the timer, suspend timing and suspend data transmission.

[0010] Optionally, the step of restoring the RLC on the terminal side includes one or more of the following:

[0011] Resume the suspended timer, resume data transmission based on the stored state variable value, continue uplink transmission of the retained RLC SDU, RLC SDU segment and / or RLC PDU, and continue to receive downlink data.

[0012] In a second aspect of an embodiment of the present invention, a satellite communication method applied to a satellite is provided, the method comprising:

[0013] A first message sent by a receiving terminal, wherein the first message is a message sent by the terminal to a target satellite based on a target beam after the terminal detects that its own wireless link connection fails and suspends the terminal-side radio link control layer protocol RLC; the first message carries a terminal identifier and a source beam identifier; the source beam is a beam for transmitting service data by the terminal before the terminal-side RLC is suspended.

[0014] Optionally, the first message is a reconstruction request message.

[0015] Optionally, the method also includes: after receiving the first message, suspending the satellite-side RLC for the terminal, obtaining context information of the terminal's service transmission in the source beam according to the terminal identifier and the source beam identifier, and synchronizing the context information with the target beam.

[0016] Optionally, the method further includes: restoring the satellite-side RLC for the terminal, sending a second message to the terminal, wherein the second message is used to instruct the terminal to restore the terminal-side RLC and resume service transmission in the target beam.

[0017] Optionally, the second message is a service recovery message.

[0018] Optionally, before suspending the satellite-side RLC for the terminal, the method further includes:

[0019] Determining, based on the source beam identifier, whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching;

[0020] If it is an intra-satellite handover, executing the step of suspending the satellite-side RLC for the terminal;

[0021] If it is an inter-satellite handover, a service reestablishment message is sent to the terminal, where the service reestablishment message is used to instruct the terminal to reestablish service transmission in the target beam.

[0022] Optionally, the method further includes:

[0023] Sending a third message to the core network, the third message including the first security parameter, so that the core network passes the first authentication when its second security parameter is consistent with the first security parameter;

[0024] After passing the first authentication, the third message is sent to the terminal, so that the terminal passes the second authentication when its third security parameter is consistent with the first security parameter.

[0025] Optionally, the third message is a security verification message.

[0026] Optionally, the satellite is in a separated satellite-ground division of labor mode, the satellite includes a centralized unit CU and a distributed unit DU, and the suspending of the satellite-side RLC for the terminal, acquiring, according to the terminal identifier and the source beam identifier, context information of the terminal performing service transmission in the source beam, and synchronizing the context information with the target beam, includes:

[0027] Suspending the satellite-side RLC for the terminal;

[0028] The CU obtains, according to the terminal identifier and the source beam identifier, context information of the terminal performing service transmission in the source beam, and sends the context information to the DU;

[0029] After receiving the terminal context information, the DU synchronizes the context information with the target beam.

[0030] Optionally, the step of suspending the satellite-side RLC for the terminal includes one or more of the following:

[0031] For the terminal, the current RLC SDU is retained, the current RLC SDU segment is retained, the current RLC PDU is retained, the current state variable value is maintained, the current value of the timer is maintained, the timing is suspended, and the data transmission is suspended.

[0032] Optionally, the step of restoring the satellite-side RLC for the terminal includes one or more of the following:

[0033] For the terminal, the suspended timer is resumed, data transmission is resumed based on the stored state variable value, the reserved RLC SDU, RLC SDU segment and / or RLC PDU are continued to be transmitted downlink, and uplink data is continued to be received.

[0034] Optionally, determining, based on the source beam identifier, whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching includes:

[0035] Determine a first satellite to which the source beam belongs according to the source beam identifier;

[0036] determining a second satellite to which the target beam belongs according to an identifier of the target beam;

[0037] Determine whether the first satellite and the second satellite are the same satellite. If so, determine that the switching from the source beam to the target beam is an intra-satellite switching; if not, determine that the switching from the source beam to the target beam is an inter-satellite switching.

[0038] In a third aspect of an embodiment of the present invention, a satellite communication device applied to a terminal is provided, the device comprising:

[0039] The sending module is used to detect that its own wireless link connection fails, suspend the terminal side radio link control layer protocol RLC, and then send a first message to the target satellite based on the target beam; the first message carries the terminal identifier and the source beam identifier; the source beam is the beam for transmitting service data by the terminal before the terminal side RLC is suspended.

[0040] Optionally, the first message is a reconstruction request message.

[0041] Optionally, the device also includes: a first recovery module, used to receive a service recovery message sent by the target satellite, restore the terminal side RLC according to the service recovery message, and restore service transmission in the target beam.

[0042] In a fourth aspect of an embodiment of the present invention, a satellite communication device applied to a satellite is provided, the device comprising:

[0043] The receiving module is used to receive a first message sent by a terminal, wherein the first message is a message sent by the terminal to a target satellite based on a target beam after the terminal detects that its own wireless link connection fails and suspends the terminal-side radio link control layer protocol RLC; the first message carries a terminal identifier and a source beam identifier; the source beam is a beam for transmitting service data by the terminal before the terminal-side RLC is suspended.

[0044] Optionally, the first message is a reconstruction request message.

[0045] Optionally, the device also includes: a synchronization module, used to suspend the satellite-side RLC for the terminal after receiving the first message, obtain the context information of the terminal performing service transmission in the source beam according to the terminal identifier and the source beam identifier, and synchronize the context information with the target beam.

[0046] Optionally, the device also includes: a second recovery module, used to restore the satellite-side RLC for the terminal, and send a second message to the terminal, wherein the second message is used to instruct the terminal to restore the terminal-side RLC and resume service transmission in the target beam.

[0047] Optionally, the second message is a service recovery message.

[0048] Optionally, the device further comprises:

[0049] A determination module is used to determine whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching based on the source beam identifier before suspending the satellite-side RLC for the terminal; if it is an intra-satellite switching, trigger the synchronization module; if it is an inter-satellite switching, send a reconstruction service message to the terminal, and the reconstruction service message is used to instruct the terminal to reconstruct the service transmission in the target beam.

[0050] Optionally, the device further comprises:

[0051] A first authentication module, configured to send a third message to a core network, wherein the third message includes a first security parameter, so that the core network passes the first authentication when its second security parameter is consistent with the first security parameter;

[0052] The second authentication module is used to send the third message to the terminal after passing the first authentication, so that the terminal passes the second authentication when its third security parameter is consistent with the first security parameter.

[0053] Optionally, the third message is a security verification message.

[0054] Optionally, the synchronization module is specifically configured to perform one or more of the following steps:

[0055] For the terminal, retain the current RLC SDU, retain the current RLC SDU segment, retain the current RLC PDU, maintain the current state variable value, keep the current value of the timer, suspend timing and suspend data transmission.

[0056] Optionally, the second recovery module is specifically configured to perform one or more of the following steps:

[0057] For the terminal, the suspended timer is resumed, data transmission is resumed based on the stored state variable value, the reserved RLC SDU, RLC SDU segment and / or RLC PDU are continued to be transmitted downlink, and uplink data is continued to be received.

[0058] Optionally, the determining module is specifically used to:

[0059] Determine a first satellite to which the source beam belongs according to the source beam identifier;

[0060] determining a second satellite to which the target beam belongs according to an identifier of the target beam;

[0061] Determine whether the first satellite and the second satellite are the same satellite. If so, determine that the switching from the source beam to the target beam is an intra-satellite switching; if not, determine that the switching from the source beam to the target beam is an inter-satellite switching.

[0062] A fifth aspect of an embodiment of the present invention further provides a terminal, including a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0063] Memory, used to store computer programs;

[0064] The processor is used to implement any of the above-mentioned satellite communication methods applied to the terminal when executing the program stored in the memory.

[0065] According to a sixth aspect of the embodiments of the present invention, there is further provided a satellite, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0066] Memory, used to store computer programs;

[0067] The processor is used to implement any of the above-mentioned satellite communication methods applied to a satellite when executing the program stored in the memory.

[0068] In a seventh aspect of the implementation of the present invention, a computer-readable storage medium is further provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any of the above-mentioned satellite communication methods is implemented.

[0069] Beneficial effects of the embodiments of the present invention:

[0070] A satellite communication method, device and satellite provided by an embodiment of the present invention can receive a reconstruction request message sent by a terminal. The reconstruction request message is a message sent by the terminal to a target satellite based on a target beam after the terminal detects that its own wireless link connection has failed and suspends the terminal-side RLC. The reconstruction request message includes a terminal identifier and a source beam identifier. The source beam is a beam that transmits service data before the terminal suspends the terminal-side RLC. The satellite-side RLC for the terminal is suspended, and context information of the terminal performing service transmission in the source beam is obtained based on the terminal identifier and the source beam identifier, and the context information is synchronized with the target beam. The satellite-side RLC for the terminal is restored, and a service restoration message is sent to the terminal. The service restoration message is used to instruct the terminal to restore the terminal-side RLC and restore service transmission in the target beam. Because the terminal will suspend RLC after detecting a connection failure, and the satellite will also suspend the satellite-side RLC for the terminal after receiving the reconstruction request message sent by the terminal, until the context information is synchronized with the target beam. The satellite restores the satellite-side RLC through the target beam according to the synchronized context information, resumes the original communication process, and sends a service recovery message to instruct the terminal to restore the terminal-side RLC, which is equivalent to the terminal and the satellite re-performing the unfinished transmission process in the source beam in the target beam and continuing the service transmission. This can avoid the problem of service data interruption that may occur during beam switching when the satellite is moving at high speed, reduce the service data loss caused by switching the source beam to the target beam, and improve the user experience.

[0071] Moreover, compared with the existing technology, this solution does not require the terminal to continuously measure adjacent beam information and upload measurement reports, nor does it require the terminal to report location information or have a GNSS module, which reduces the demand for terminal processing capabilities and power consumption and reduces the cost required for the terminal.

[0072] Of course, it is not necessary to achieve all of the advantages described above at the same time to implement any product or method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0074] Figure 1 A flowchart of a satellite communication method provided by an embodiment of the present invention;

[0075] Figure 2 A flowchart of another satellite communication method provided by an embodiment of the present invention;

[0076] Figure 3A satellite communication flow chart in an integrated satellite-ground division of labor mode provided by an embodiment of the present invention;

[0077] Figure 4 A satellite communication flow chart in a separated satellite-ground division of labor mode provided by an embodiment of the present invention;

[0078] Figure 5 A schematic diagram of the structure of a satellite communication device provided by an embodiment of the present invention;

[0079] Figure 6 A schematic diagram of the structure of a satellite provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0080] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field based on this application belong to the scope of protection of the present invention.

[0081] The speed of satellite movement relative to the ground is very fast, and the terminal needs to frequently switch between intra-satellite beams and between satellites. Each beam switch will result in the loss of service data. At the same time, the processing power of IoT or low-rate data terminals is low, and there are strict requirements on power consumption. Therefore, IoT or low-rate data terminals should not continuously measure adjacent beam signals and report measurement reports, nor should they frequently report location information. Some terminals do not even have GNSS modules. Therefore, the access network side lacks necessary input information and cannot make effective switching decisions.

[0082] In order to solve the above technical problems, the present application provides a satellite communication method, such as Figure 1 As shown, Figure 1 A flowchart of a satellite communication method provided by an embodiment of the present invention includes:

[0083] Step S101, receiving a reestablishment request message sent by a terminal, where the reestablishment request message is a message sent by the terminal to a target satellite based on a target beam after the terminal detects that its own wireless link connection fails and suspends the terminal-side RLC.

[0084] In this embodiment, when a terminal (User Equipment, UE) in a connected state detects that a radio link connection fails, it triggers an RRC (Radio Resource Control) reconstruction process. Specifically, the terminal suspends the terminal-side RLC (Radio Link Control), then searches for downlink signals in the network, selects a beam that exceeds the threshold as the target beam for RRC reconstruction, and then sends a reconstruction request message to the satellite based on the target beam.

[0085] In this embodiment, the beam exceeding the threshold can be understood as a beam whose signal exceeds a preset threshold. The terminal can select any beam exceeding the threshold as the target beam for RRC reconstruction, or select the beam with the best signal as the target beam.

[0086] The RLC layer is located between the RRC layer and the MAC (Media Access Control) layer.

[0087] In this embodiment, the reestablishment request message includes a terminal identifier (ID) and a source beam identifier. The terminal identifier is used to identify user information. The source beam is a beam that transmits service data before the terminal suspends the terminal side RLC.

[0088] Step S102: suspend the satellite-side RLC for the terminal, obtain the context information of the terminal performing service transmission in the source beam according to the terminal identifier and the source beam identifier, and synchronize the context information with the target beam.

[0089] In one embodiment of the present invention, suspending RLC may include one or more of the following: for the terminal, retaining the current RLC SDU, retaining the current RLC SDU segment, retaining the current RLC PDU, maintaining the current state variable value, maintaining the current value of the timer, suspending timing and suspending data transmission.

[0090] Among them, SDU (Service Data Unit) is used to transfer data between RLC layers. RLC SDU segmentation refers to the segmentation of a larger RLC SDU into smaller data segments. RLC PDU (Protocol Data Unit) is formed after the RLC SDU is segmented and encapsulated, and is used to transfer data between wireless links. The RLC layer at the sending end segments the RLC SDU to obtain RLC SDU segments. The receiving end encapsulates the RLC SDU segments.

[0091] Those skilled in the art can understand that in satellite communication, the satellite is used to carry the access network, and the RLC layer is part of the access network. During the communication process, in the satellite accessed by the terminal, RLC layer resources are allocated to the terminal. In the embodiment of the present invention, suspending the satellite-side RLC for the terminal means suspending the RLC layer allocated to the terminal in the access satellite, that is, suspending the original processing steps of the RLC layer.

[0092] In the embodiment of the present invention, the context information may include unprocessed RLC layer data, timer information, SN (Serial Number) status, data sending and receiving status, and the like.

[0093] Among them, the processed RLC layer data refers to the RLC layer data that is sent to the terminal after being processed by the RLC layer and is confirmed to have been received by the terminal. For the unprocessed RLC layer data, such as the unprocessed RLC PDU, RLC SDU segment, and RLC SDU, it is necessary to synchronize to the target beam as context information.

[0094] Step S103: Restore the satellite-side RLC for the terminal and send a service recovery message to the terminal. The service recovery message is used to instruct the terminal to restore the terminal-side RLC and resume service transmission in the target beam.

[0095] In this embodiment, because the context information is information about the service transmission of the terminal in the source beam, including the RLC layer data that has not been processed, after synchronizing the context information to the target beam, the satellite can restore the satellite-side RLC in the target beam and instruct the terminal to restore the terminal-side RLC, so that the service transmission can be restored based on the target beam according to the context information transferred to the target beam, that is, the unfinished transmission process in the source beam can be continued.

[0096] In one embodiment of the present invention, the step of restoring the satellite-side RLC for the terminal includes one or more of the following: for the terminal, resuming the suspended timer, resuming data transmission based on the stored state variable value, continuing the downlink transmission of the retained RLC SDU, RLC SDU segmentation and / or RLC PDU, and continuing to receive uplink data.

[0097] In this embodiment, a reconstruction request message sent by a terminal can be received. The reconstruction request message is a message sent by the terminal to the target satellite based on the target beam after the terminal detects that its own wireless link connection fails and suspends the terminal-side RLC. The reconstruction request message includes a terminal identifier and a source beam identifier. The source beam is a beam that transmits service data before the terminal suspends the terminal-side RLC. The satellite-side RLC for the terminal is suspended, and the context information of the terminal performing service transmission in the source beam is obtained according to the terminal identifier and the source beam identifier, and the context information is synchronized with the target beam. The satellite-side RLC for the terminal is restored, and a service restoration message is sent to the terminal. The service restoration message is used to instruct the terminal to restore the terminal-side RLC and restore service transmission in the target beam. Because the terminal will suspend the terminal side RLC after detecting the connection failure, and the satellite will also suspend the satellite side RLC for the terminal after receiving the reconstruction request message sent by the terminal, until the context information is synchronized with the target beam. The satellite restores the satellite side RLC through the target beam according to the synchronized context information, resumes the original communication process, and sends a service recovery message to instruct the terminal to restore the terminal side RLC, which is equivalent to the terminal and the satellite re-performing the unfinished transmission process in the source beam in the target beam and continuing the service transmission. This can avoid the problem of service data interruption that may occur during beam switching when the satellite is moving at high speed, reduce the service data loss caused by switching the source beam to the target beam, and improve the user experience.

[0098] In addition, because the terminal in this solution does not need to continuously measure adjacent beam signals, report measurement reports, or frequently report location information to the access network, the terminal in the embodiment of the present invention can be some low-cost terminals with low processing capabilities and strict requirements on power consumption. For example, it can be an Internet of Things terminal or a low-rate data terminal. It can also be a terminal without a GNSS module.

[0099] For satellite communication systems, the speed of satellite movement relative to the ground is very fast, and the terminal needs to frequently switch between intra-satellite beams and inter-satellite beams. During the beam switching process, the switching between the source beam and the target beam can be divided into inter-satellite switching or intra-satellite switching according to different scenarios. Therefore, before suspending the satellite-side RLC for the terminal, it is also necessary to judge whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching based on the source beam identifier. Based on the source beam identifier, it is determined that the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching. Specifically, the first satellite to which the source beam belongs can be determined according to the source beam identifier, and the second satellite to which the target beam belongs can be determined according to the target beam identifier. Determine whether the first satellite and the second satellite are the same satellite. If so, determine that the switching from the source beam to the target beam is an intra-satellite switching. If not, determine that the switching from the source beam to the target beam is an inter-satellite switching.

[0100] For example, the first satellite to which the source beam belongs is determined to be satellite 1 according to the identifier of the source beam, and the second satellite to which the target beam belongs is determined to be satellite 1 according to the identifier of the target beam. The first satellite and the second satellite are the same satellite, so the switching from the source beam to the target beam is determined to be intra-satellite switching. If the first satellite to which the source beam belongs is determined to be satellite 1 according to the identifier of the source beam, and the second satellite to which the target beam belongs is determined to be satellite 2 according to the identifier of the target beam. The first satellite and the second satellite are not the same satellite, so the switching from the source beam to the target beam is determined to be inter-satellite switching.

[0101] If it is an intra-satellite handover, the above-mentioned steps of suspending the satellite-side RLC for the terminal are performed. If it is an inter-satellite handover, a service reestablishment message is sent to the terminal, and the service reestablishment message is used to instruct the terminal to reestablish service transmission in the target beam. At this time, RLC resets all timers, resets all state variables to initial values, and discards all RLC SDUs, RLC SDU segments, and RLC PDUs.

[0102] This application provides different processing methods for the two different scenarios of intra-satellite handover and inter-satellite handover. Figure 2 As shown, Figure 2 A flowchart of another satellite communication method provided by an embodiment of the present invention includes:

[0103] Step S201: the terminal indicates a suspend operation.

[0104] The connected UE detects a radio link failure, triggers the RRC reestablishment process, and the terminal suspends the terminal-side RLC.

[0105] Step S202: Send a reconstruction request.

[0106] After the terminal suspends the terminal-side RLC, the terminal sends a reestablishment request message to the RRC layer of the access network (the access network is carried on the satellite).

[0107] Step S203: the access network instructs the suspension operation.

[0108] After receiving the reestablishment request message, the access network RRC layer instructs to suspend the access network side RLC.

[0109] Step S204: Send a service recovery message or a service reconstruction message.

[0110] The switching mode is determined according to the intra-satellite cross-beam and inter-satellite environment. Specifically, based on the source beam identifier, it is determined whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching. If it is an intra-satellite switching, a service recovery message is sent. If it is an inter-satellite switching, a service reconstruction message is sent.

[0111] Step S205, indicating recovery or reconstruction.

[0112] If the message received by the terminal is a service recovery message, the terminal side RLC is restored in the target beam, and service transmission is restored in the target beam. If the message received by the terminal is a service reestablishment message, service transmission is reestablished in the target beam.

[0113] Step S206: Send a service recovery completion message or a service reconstruction completion message.

[0114] After the terminal completes restoring the service or reestablishing the service, it sends a service restoration completion message or a service reestablishment completion message to the access network.

[0115] Step S207, indicating recovery or reconstruction.

[0116] If the message received by the access network is a service recovery completion message, the RLC on the access network side is restored. If the message received by the access network is a service reestablishment completion message, the RLC on the access network side is reestablished.

[0117] In this embodiment, based on the source beam identifier, it can be determined whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching. According to the intra-satellite or inter-satellite environment, the RLC and the service can be rebuilt or restored. Different processing procedures are selected for different scenarios, further ensuring the continuity of the service.

[0118] Authentication is required to ensure the identity and information security of terminals and satellites and to guarantee network security and quality.

[0119] In this embodiment, a security message is sent to the core network AMF (Access and Mobility Management Function) via the satellite for the first authentication, and then the satellite sends a security message to the terminal for the second authentication, thereby achieving two-way authentication and ensuring the security of the communication process.

[0120] The core network generates authentication information based on security keys and NAS Count (Non-Access Stratum Count). Among them, the security key is used to encrypt and decrypt communication data and is a cryptographic key used to protect the security of communication data. NAS Count is an increasing counter that can prevent replay attacks and ensure the uniqueness of authentication information. Each time the authentication process is performed, NAS Count will increase automatically to ensure that the generated authentication information will not be reused. By combining the security key and NAS Count, AMF can generate a unique authentication information related to a specific authentication process. This authentication information can be used to verify the identity and authority of the user terminal and ensure the security of the communication process.

[0121] There are two common structural modes in satellite communication systems, namely the integrated satellite-ground division of labor mode and the separated satellite-ground division of labor mode. There are two logical network elements in the satellite, namely CU (Centralized Unit) and DU (Distributed Unit). Corresponding to different scenarios and needs, CU and DU can be deployed separately or as a whole. In the integrated satellite-ground division of labor mode, CU and DU are deployed as a whole. In the separated satellite-ground division of labor mode, CU and DU are deployed separately.

[0122] The CU supports the upper layers of the protocol stack and is used to perform the functions of the RRC layer, SDAP (service data adaptation protocol) layer, and PDCP (packet data convergence protocol) layer. The DU supports the lower layers of the protocol stack and is used to perform the functions of the RLC layer, MAC layer, and PHY (physical) layer. The DU and CU communicate via the F1 interface.

[0123] In order to further illustrate the specific steps for two-way authentication and two different structural modes in a satellite communication system, the present application provides two exemplary scenarios.

[0124] Scenario 1 is the satellite communication process of the integrated satellite-ground division of labor mode, such as Figure 3 As shown, Figure 3 The satellite communication flow chart in the integrated satellite-ground division of labor mode provided by the embodiment of the present invention includes:

[0125] S301: The terminal detects that the wireless link fails.

[0126] When a terminal in a connected state detects a radio link failure, an RRC reestablishment process is triggered.

[0127] S302, sending an RRC reestablishment request message.

[0128] The UE searches for the downlink signal in the network, selects the beam with the best signal as the target beam for link RRC reconstruction, and sends an RRCReestablishmentRequest message through the RACH (Random Access Channel). The RRCReestablishmentRequest message mainly includes parameters such as UE ID (terminal identifier) ​​and source BEAM ID (beam identifier).

[0129] S303, the satellite obtains terminal context information from the source beam.

[0130] The satellite obtains the terminal context information from the source beam according to the source beam identifier and the terminal identifier in the RRC reestablishment request message, wherein the terminal context information includes the unprocessed RLC PDU.

[0131] S304: Send an access response.

[0132] The satellite sends an access response to the terminal, notifying the terminal that a connection has been established with the satellite based on the target beam.

[0133] S305: Send a RAN CP relocation message.

[0134] The satellite sends a RAN CP Relocation Indication (Radio Access Network Control Plane Relocation Indication) message carrying the first security parameter to the core network AMF.

[0135] The RAN CP Relocation Indication message can be understood as an indication message sent by the RAN CP to the AMF when a relocation occurs. The AMF performs an authentication operation on the terminal based on this indication message and feeds back the result to the access network.

[0136] S306, NAS identity authentication.

[0137] The core network AMF generates a second security parameter based on the security key and NAS Count, and compares it with the first security parameter in the RAN CP relocation message. If the two are consistent, the first authentication is successful.

[0138] S307: Send a connection establishment indication message.

[0139] After the first authentication is passed, the AMF sends a Connection Establish Indication message to the satellite, and the connection establishment indication message carries the first security parameter.

[0140] S308, IoT RRC reconstruction.

[0141] After receiving the connection establishment indication message sent by the AMF, the satellite sends an RRCReestablishment message to the terminal, and the RRCReestablishment message carries the first security parameter.

[0142] S309, NAS authentication.

[0143] The terminal compares the first security parameter in the RRC reconstruction message with the third security parameter generated by the terminal NAS layer based on the security key. If the two are consistent, the second authentication is passed.

[0144] S310, IoT RRC reconstruction completion message.

[0145] The terminal sends an RRCReestablishmentComplete (RRC Reestablishment Complete) message to the satellite to complete the RRC reestablishment process.

[0146] After executing step S310, it can be determined whether service reconstruction or service recovery is performed for the terminal according to whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching.

[0147] If it is an inter-satellite handover, a service reestablishment message is sent to the terminal to instruct the terminal to reestablish service transmission in the target beam. RLC resets all timers, resets all state variables to initial values, and discards all RLC SDUs, RLC SDU segments, and RLC PDUs.

[0148] If it is an intra-satellite handover, the satellite-side RLC for the terminal is restored, a service restoration message is sent to the terminal, instructing the terminal to restore the terminal-side RLC, and resume service transmission in the target beam. The step of restoring the satellite-side RLC for the terminal includes one or more of the following: for the terminal, resuming a suspended timer, resuming data transmission based on a stored state variable value, continuing downlink transmission of the reserved RLC SDU, RLC SDU segment and / or RLC PDU, and continuing to receive uplink data.

[0149] In this embodiment, for satellites in an integrated satellite-ground division of labor mode, when a terminal in a connected state detects a link connection failure, the RRC reconstruction process is triggered, and the terminal sends an RRC reconstruction request message to the satellite. The satellite can obtain the context information of the terminal's service transmission in the source beam based on the source beam identifier and terminal identifier in the RRC reconstruction request message. Then it enters the authentication phase, and the first authentication is performed with the AMF through the satellite. After the first authentication is passed, the satellite performs a second authentication with the terminal, and then the terminal sends an RRC establishment completion message to the satellite to complete the RRC reconstruction process. In this embodiment, the identity and information security of the terminal and the satellite, as well as the security of the entire communication process, are ensured through two-way authentication.

[0150] Scenario 2 is a satellite communication process in a separated satellite-ground division of labor mode. The satellite adopts a CU-DU separation architecture, such as Figure 4 As shown, Figure 4 The satellite communication flow chart in the separated satellite-ground division of labor mode provided by the embodiment of the present invention includes:

[0151] Step S401: The terminal detects that the wireless link fails.

[0152] The terminal in the connected state detects that the radio link connection fails, triggering the RRC reestablishment process.

[0153] Step S402: The terminal sends an RRC reestablishment request message.

[0154] The terminal searches for downlink signals in the network, selects the beam whose signal exceeds the threshold as the target beam for link reconstruction, and sends a reconstruction request message to the target beam through RACH. The reconstruction request message mainly includes parameters such as UE ID and source BEAM ID.

[0155] Step S403: DU sends an RRC reestablishment request message.

[0156] After receiving the reconstruction request message, the DU forwards the reconstruction request message to the CU.

[0157] Step S404: The CU obtains terminal context information from the source beam.

[0158] The CU obtains the terminal context information according to the source beam identifier and the terminal identifier in the reconstruction request message, wherein the terminal context information includes the unprocessed RLC PDU.

[0159] Step S405: CU sends a terminal context setting request message.

[0160] After acquiring the terminal context information, the CU sends a terminal context information setting request message to the DU.

[0161] Step S406: The DU sends a random access response to the terminal.

[0162] After receiving the terminal context setup request message, the DU sends an access response to the terminal, notifying the terminal that a connection has been established with the satellite based on the target beam.

[0163] Step S407: DU returns a terminal context setting response message to CU.

[0164] After receiving the terminal context setting request message, the DU sends a terminal context setting response message to the CU.

[0165] Step S408: The CU sends a RAN CP relocation message to the core network.

[0166] The CU sends a RAN CP relocation message to the core network AMF, which carries the first security parameter.

[0167] Step S409: The core network performs NAS identity authentication.

[0168] The core network generates authentication information, namely the second security parameter, based on the security key and NAS Count, and compares it with the first security parameter in the RAN CP relocation message. If the two are consistent, the first authentication is successful.

[0169] Step S410: The core network sends a connection establishment indication message to the CU.

[0170] After the first authentication is passed, the core network sends a connection establishment indication message carrying the first security parameter to the CU.

[0171] Step S411: CU transmits an RRC message to DU.

[0172] After the CU receives the connection establishment indication message carrying the first security parameter, it performs DL (Downlink) RRC information transmission and sends an RRC reconstruction message to the DU.

[0173] Step S412: The DU sends an RRC reestablishment message to the terminal.

[0174] After receiving the RRC reconstruction message sent by the CU, the DU forwards the RRC reconstruction message to the terminal, and the RRC reconstruction message includes the first security parameter.

[0175] Step S413: The terminal performs NAS identity authentication.

[0176] The terminal NAS layer generates a third security parameter based on the security key, and then compares the first security parameter in the RRC re-establishment message with the third security parameter. If the two are consistent, the second authentication is passed.

[0177] Step S414: The terminal sends an RRC reestablishment completion message to the DU.

[0178] After passing the second authentication, the terminal sends an RRC re-establishment completion message to the DU.

[0179] Step S415, the DU sends an RRC reestablishment completion message to the CU.

[0180] After receiving the RRC reconstruction completion message, the DU performs UL (Uplink) RRC information transmission and forwards the RRC reconstruction completion message to the CU to complete the RRC reconstruction process.

[0181] After executing step S415, it can be determined whether to perform service reconstruction or service recovery for the terminal according to whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching.

[0182] If it is an inter-satellite handover, a service reestablishment message is sent to the terminal to instruct the terminal to reestablish service transmission in the target beam. RLC resets all timers, resets all state variables to initial values, and discards all RLC SDUs, RLC SDU segments, and RLC PDUs.

[0183] If it is an intra-satellite handover, the satellite-side RLC for the terminal is restored, and a service restoration message is sent to the terminal to instruct the terminal to restore the terminal-side RLC, and resume service transmission in the target beam. Among them, the step of restoring the satellite-side RLC for the terminal includes one or more of the following: for the terminal, resuming the suspended timer, resuming data transmission based on the stored state variable value, continuing the downlink transmission of the retained RLC SDU, RLC SDU segmentation and / or RLC PDU, and continuing to receive uplink data. In this embodiment, for satellites in a separated satellite-ground division of labor mode, after the terminal detects a connection failure and triggers RRC reconstruction, the DU is responsible for communication with the terminal, and the CU is responsible for communication with the core network, thereby realizing the RRC reconstruction process. For satellites in a separated satellite-ground division of labor mode, this embodiment can avoid the problem of service data interruption of the terminal during beam switching, and reduce the service data loss caused by beam switching. At the same time, the security of the entire communication process can be ensured through two-way authentication.

[0184] Based on the same inventive concept, the present application accordingly provides a satellite communication device, such as Figure 5 As shown, Figure 5 A schematic structural diagram of a satellite communication device provided by an embodiment of the present invention includes:

[0185] The receiving module 501 is used to receive a reconstruction request message sent by the terminal. The reconstruction request message is a message sent by the terminal to the target satellite based on the target beam after the terminal detects that its own wireless link connection fails and suspends the terminal side RLC. The reconstruction request message includes a terminal identifier and a source beam identifier. The source beam is a beam for transmitting service data before the terminal suspends the terminal side RLC.

[0186] The synchronization module 502 is used to suspend the satellite-side RLC for the terminal, obtain the context information of the terminal performing service transmission in the source beam according to the terminal identifier and the source beam identifier, and synchronize the context information with the target beam.

[0187] The recovery module 503 is used to recover the satellite-side RLC for the terminal and send a service recovery message to the terminal. The service recovery message is used to instruct the terminal to recover the terminal-side RLC and recover service transmission in the target beam.

[0188] In this embodiment, a reconstruction request message sent by a terminal is received by a receiving module 501. The reconstruction request message is a message sent by the terminal to a target satellite based on a target beam after the terminal detects that its own wireless link connection has failed and suspends the terminal-side RLC. The reconstruction request message includes a terminal identifier and a source beam identifier. The source beam is a beam that transmits service data before the terminal suspends the terminal-side RLC. The satellite-side RLC for the terminal is suspended by a synchronization module 502, and context information of service transmission of the terminal in the source beam is obtained according to the terminal identifier and the source beam identifier, and the context information is synchronized with the target beam. The satellite-side RLC for the terminal is restored by a recovery module 503, and a service recovery message is sent to the terminal. The service recovery message is used to instruct the terminal to restore the terminal-side RLC and restore service transmission in the target beam. Because the terminal will suspend the terminal side RLC after detecting the connection failure, and the satellite will also suspend the satellite side RLC for the terminal after receiving the reconstruction request message sent by the terminal, until the context information is synchronized with the target beam. The satellite restores the satellite side RLC through the target beam according to the synchronized context information, resumes the original communication process, and sends a service recovery message to instruct the terminal to restore the terminal side RLC, which is equivalent to the terminal and the satellite re-performing the unfinished transmission process in the source beam in the target beam and continuing the service transmission. This can avoid the problem of service data interruption that may occur during beam switching when the satellite is moving at high speed, reduce the service data loss caused by switching the source beam to the target beam, and improve the user experience.

[0189] In a possible embodiment, the device further includes:

[0190] A determination module, used for determining whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching based on the source beam identifier before suspending the satellite-side RLC for the terminal;

[0191] If it is an intra-satellite handover, the step of suspending the satellite-side RLC for the terminal is performed;

[0192] If it is an inter-satellite handover, a service reconstruction message is sent to the terminal, and the service reconstruction message is used to instruct the terminal to reconstruct service transmission in the target beam.

[0193] In a possible embodiment, the device further includes:

[0194] A first authentication module is used to send a security message to the core network, where the security message includes a first security parameter, so that the core network passes the first authentication when its second security parameter is consistent with the first security parameter;

[0195] The second authentication module is used to send a security message to the terminal after passing the first authentication, so that the terminal passes the second authentication when its third security parameter is consistent with the first security parameter.

[0196] In a possible embodiment, the synchronization module is specifically used to suspend the satellite-side RLC for the terminal when the satellite is in a separated satellite-ground division of labor mode, and the CU obtains the context information of the terminal performing service transmission in the source beam according to the terminal identifier and the source beam identifier, and sends the context information to the distribution unit;

[0197] After receiving the terminal context information, the DU synchronizes the context information with the target beam.

[0198] In a possible embodiment, the synchronization module is specifically configured to perform one or more of the following steps:

[0199] For the terminal, retain the current RLC SDU, retain the current RLC SDU segment, retain the current RLC PDU, maintain the current state variable value, keep the current value of the timer, suspend timing and suspend data transmission.

[0200] In a possible embodiment, the recovery module is specifically configured to perform one or more of the following steps:

[0201] For the terminal, the suspended timer is resumed, data transmission is resumed based on the stored state variable value, the retained RLC SDU, RLC SDU segment and / or RLC PDU are continued to be transmitted downlink, and uplink data is continued to be received.

[0202] In a possible embodiment, the determination module is specifically configured to:

[0203] Determine a first satellite to which the source beam belongs according to the source beam identifier;

[0204] determining a second satellite to which the target beam belongs according to an identifier of the target beam;

[0205] It is determined whether the first satellite and the second satellite are the same satellite. If so, it is determined that the switching from the source beam to the target beam is an intra-satellite switching; if not, it is determined that the switching from the source beam to the target beam is an inter-satellite switching.

[0206] The embodiment of the present invention further provides a satellite, such as Figure 6 As shown, it includes a processor 601, a communication interface 602, a memory 603 and a communication bus 604, wherein the processor 601, the communication interface 602, and the memory 603 communicate with each other through the communication bus 604.

[0207] Memory 603, used for storing computer programs;

[0208] The processor 601 is used to execute the program stored in the memory 603 to implement the following steps:

[0209] A reestablishment request message sent by a receiving terminal is a message sent by the terminal to a target satellite based on a target beam after the terminal detects that its own wireless link connection fails and suspends the terminal side RLC; the reestablishment request message includes a terminal identifier and a source beam identifier; the source beam is a beam for transmitting service data before the terminal suspends the terminal side RLC;

[0210] Suspend the satellite-side RLC for the terminal, obtain the context information of the terminal's service transmission in the source beam according to the terminal identifier and the source beam identifier, and synchronize the context information with the target beam;

[0211] Restore the satellite-side RLC for the terminal and send a service recovery message to the terminal. The service recovery message is used to instruct the terminal to restore the terminal-side RLC and resume service transmission in the target beam.

[0212] The communication bus mentioned in the above satellite can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0213] The communication interface is used for communication between the above satellites and other equipment.

[0214] The memory may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0215] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0216] In another embodiment of the present invention, a computer-readable storage medium is provided, in which a computer program is stored. When the computer program is executed by a processor, the steps of any one of the above-mentioned satellite communication methods are implemented.

[0217] In another embodiment of the present invention, a computer program product including instructions is provided. When the computer program product is executed on a computer, the computer executes any one of the satellite communication methods in the above embodiments.

[0218] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk Solid State Disk (SSD)), etc.

[0219] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0220] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, satellite, computer-readable storage medium, and computer program product embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0221] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A satellite communication method, characterized in that: Applied to a terminal, the method comprises: The terminal detects that its own wireless link connection fails, suspends the terminal side wireless link control layer protocol RLC, and then sends a first message to the target satellite based on the target beam; the first message carries the terminal identifier and the source beam identifier; the source beam is the beam used by the terminal to transmit service data before the terminal side RLC is suspended.

2. The method according to claim 1, characterized in that The first message is a reconstruction request message.

3. The method according to claim 1, characterized in that The method further comprises: Receive a service recovery message sent by the target satellite, restore the terminal side RLC according to the service recovery message, and restore service transmission in the target beam.

4. The method according to claim 1, characterized in that: The step of suspending the terminal side RLC includes one or more of the following: Keep the current RLC SDU, keep the current RLC SDU segment, keep the current RLC PDU, maintain the current state variable value, keep the current value of the timer, suspend timing and suspend data transmission.

5. The method according to claim 3, characterized in that: The step of restoring the RLC on the terminal side includes one or more of the following: Resume the suspended timer, resume data transmission based on the stored state variable value, continue uplink transmission of the retained RLC SDU, RLC SDU segments and / or RLC PDU, and continue to receive downlink data.

6. A satellite communication method, characterized in that: Applied to a satellite, the method comprises: A first message sent by a receiving terminal, wherein the first message is a message sent by the terminal to a target satellite based on a target beam after the terminal detects that its own wireless link connection fails and suspends the terminal-side radio link control layer protocol RLC; the first message carries a terminal identifier and a source beam identifier; the source beam is a beam for transmitting service data by the terminal before the terminal-side RLC is suspended.

7. The method according to claim 6, characterized in that The method further comprises: After receiving the first message, the satellite-side RLC for the terminal is suspended, and context information of the terminal's service transmission in the source beam is obtained according to the terminal identifier and the source beam identifier, and the context information is synchronized with the target beam.

8. The method according to claim 7, characterized in that The method further comprises: Restore the satellite-side RLC for the terminal, and send a second message to the terminal, where the second message is used to instruct the terminal to restore the terminal-side RLC and resume service transmission in the target beam.

9. The method according to claim 8, characterized in that The second message is a service recovery message.

10. The method according to claim 6, characterized in that Before suspending the satellite-side RLC for the terminal, the method further includes: Determining, based on the source beam identifier, whether the switching from the source beam to the target beam is an inter-satellite switching or an intra-satellite switching; If it is an intra-satellite handover, executing the step of suspending the satellite-side RLC for the terminal; If it is an inter-satellite handover, a service reestablishment message is sent to the terminal, where the service reestablishment message is used to instruct the terminal to reestablish service transmission in the target beam.

11. The method according to claim 6, characterized in that The method further comprises: Sending a third message to the core network, the third message including the first security parameter, so that the core network passes the first authentication when its second security parameter is consistent with the first security parameter; After passing the first authentication, the third message is sent to the terminal, so that the terminal passes the second authentication when its third security parameter is consistent with the first security parameter.

12. The method according to claim 11, characterized in that The third message is a security verification message.

13. The method according to claim 6, characterized in that The satellite is in a separated satellite-ground division of labor mode, the satellite includes a centralized unit CU and a distributed unit DU, and the suspending of the satellite-side RLC for the terminal, acquiring context information of the terminal performing service transmission in the source beam according to the terminal identifier and the source beam identifier, and synchronizing the context information with the target beam, including: Suspending the satellite-side RLC for the terminal; The CU obtains, according to the terminal identifier and the source beam identifier, context information of the terminal performing service transmission in the source beam, and sends the context information to the DU; After receiving the terminal context information, the DU synchronizes the context information with the target beam.

14. The method according to claim 7, characterized in that The step of suspending the satellite side RLC for the terminal includes one or more of the following: For the terminal, the current RLC SDU is retained, the current RLC SDU segment is retained, the current RLC PDU is retained, the current state variable value is maintained, the current value of the timer is maintained, the timing is suspended, and the data transmission is suspended.

15. The method according to claim 8, characterized in that The step of restoring the satellite side RLC for the terminal includes one or more of the following: For the terminal, the suspended timer is resumed, data transmission is resumed based on the stored state variable value, the reserved RLC SDU, RLC SDU segment and / or RLC PDU are continued to be transmitted downlink, and uplink data is continued to be received.

16. A satellite communication device, characterized in that: Applied to a terminal, the device comprises: The sending module is used to detect that its own wireless link connection fails, suspend the terminal side radio link control layer protocol RLC, and then send a first message to the target satellite based on the target beam; the first message carries the terminal identifier and the source beam identifier; the source beam is the beam for transmitting service data by the terminal before the terminal side RLC is suspended.

17. A satellite communication device, characterized in that: Applied to a satellite, the device comprises: The receiving module is used to receive a first message sent by a terminal, wherein the first message is a message sent by the terminal to a target satellite based on a target beam after the terminal detects that its own wireless link connection fails and suspends the terminal-side radio link control layer protocol RLC; the first message carries a terminal identifier and a source beam identifier; the source beam is a beam for transmitting service data by the terminal before the terminal-side RLC is suspended.

18. A terminal, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, for implementing any of the methods described in claims 1-5 when executing a program stored in a memory.

19. A satellite, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, for implementing any of the methods described in claims 6-15 when executing a program stored in a memory.

20. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described in any one of claims 1-5 or 6-15 is implemented.

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