Inter-satellite laser communication link breakage and continuation method and device, communication equipment and storage medium

Abstract

The application relates to an intersatellite laser communication link breakage continuation transmission method and device, a communication device and a storage medium. Four key fields of data types, data frame serial numbers, receiving link states and receiving effective frame serial numbers are designed in a frame header of an intersatellite transmission frame, and a double-pointer management mechanism of a sending buffer reading pointer and a deleting pointer is matched, so that fine control of intersatellite laser communication of a relay satellite is realized. After link interruption recovery, the starting position of data sending is determined again based on the receiving effective frame serial number field in the receiving frame and the pointer position, data transmission is continued from the breakpoint, and therefore, the data integrity and continuity of intersatellite laser communication of the relay satellite are maximally ensured, and the data relay service quality and reliability of the relay satellite constellation are effectively improved.

Description

Technical Field

[0001] This application relates to the field of satellite communication technology, and in particular to a method, apparatus, communication equipment, computer-readable storage medium, and computer program product for resuming inter-satellite laser communication after a link break. Background Technology

[0002] With the development of space information network technology, laser communication has been widely used in inter-satellite and space-to-ground data transmission due to its high bandwidth and narrow beam characteristics. In the complex space environment, micro-vibrations of the satellite platform (such as the rotation of solar panels) or equipment malfunctions may cause momentary interruptions in laser communication links. These link interruptions result in the loss of data modulated onto the laser beam.

[0003] In traditional technologies, data retransmission mechanisms after link restoration, particularly for remote sensing satellite-to-ground transmission, typically involve retransmitting the entire file via command after link recovery. However, for laser communication between medium- and high-orbit relay satellites, the transmission mode is unique: relay satellites usually do not persistently store data for extended periods, and the transmitted data is often a multiplexed, mixed stream from multiple low-orbit user satellites. Using traditional file-level retransmission would not only result in poor timeliness but also lead to the repeated transmission of a large amount of irrelevant data, severely impacting relay service quality and link efficiency. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, apparatus, communication equipment, computer-readable storage medium, and computer program product for resuming inter-satellite laser communication after a link break, in order to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a method for resuming interrupted inter-satellite laser communication transmission. The method is applied to the laser communication payload of a first relay satellite acting as the data sender in inter-satellite laser communication. The laser communication payload has a transmission buffer. The method includes: The user data stream to be transmitted is stored in the transmission buffer; If the communication link with the second relay satellite is confirmed to be normal, data is read from the transmission buffer according to the preset data length and assembled into an inter-satellite transmission frame, and the inter-satellite transmission frame is sent to the second relay satellite; the inter-satellite transmission frame has a frame header for characterizing data attributes and current status, and the frame header includes a data type field, a data frame sequence number field, a receiving link status field, and a received valid frame sequence number field; Real-time monitoring of inter-satellite transmission frames from the second relay satellite; and performing corresponding pointer operations on the transmission buffer to determine the pointer position based on at least one of the receive link status field and the receive valid frame sequence number field in the frame header of the received inter-satellite transmission frame. If a communication link with the second relay satellite is detected to be interrupted, the communication link with the second relay satellite is re-established; the starting position of data transmission is determined according to the received valid frame sequence number field in the frame header of the inter-satellite transmission frame from the second relay satellite and the pointer position, so as to realize the data resume transmission from the breakpoint.

[0006] In one embodiment, the data type field is used to characterize the frame type of the corresponding inter-satellite transmission frame, the frame type including a data frame or an idle frame; The data frame sequence number field is used to represent the frame sequence number of the corresponding inter-satellite transmission frame; The receiving link status field is used to characterize its own receiving status, which includes normal receiving status or abnormal receiving status. The received valid frame sequence number field is used to represent the data frame sequence number of the last frame sent by the peer that the receiver has confirmed has been received.

[0007] In one embodiment, the step of reading data from the transmission buffer according to a preset data length and assembling it into an inter-satellite transmission frame includes: Read user data of a preset length starting from the read pointer of the send buffer; Based on the user data and the current state, a frame header is determined, and the frame header and the user data are concatenated to obtain an uncoded transmission frame. Perform forward error correction coding on the uncoded transmission frame to obtain a check bit with a first fixed length; By concatenating the unencoded transmission frame and the check bit, an encoded transmission frame is obtained; A second fixed-length frame synchronization word is appended to the header of the encoded transmission frame to obtain the inter-satellite transmission frame.

[0008] In one embodiment, the step of performing a corresponding pointer operation on the transmit buffer to determine the pointer position based on at least one of the receive link status field and the receive valid frame sequence number field in the frame header of the received inter-satellite transmission frame includes: If the receiving link status field in the frame header of the received inter-satellite transmission frame indicates that the receiving end is in a normal receiving state, a read operation is performed on the transmission buffer. The read operation involves reading user data of a preset data length from the read pointer of the transmission buffer, assembling it into an inter-satellite transmission frame, and moving the read pointer to update its position. If the received valid frame sequence number field in the frame header of the received inter-satellite transmission frame is updated and is not equal to the locally recorded confirmed data frame sequence number, a deletion operation is performed on the transmission buffer. The deletion operation involves deleting confirmed data starting from the deletion pointer in the transmission buffer, moving the deletion pointer, and updating the position of the deletion pointer. If the receiver is determined to be in an abnormal reception state based on the receive link status field in the frame header of the received inter-satellite transmission frame, a rollback operation is performed on the transmit buffer; the rollback operation is to roll back the read pointer to the position of the delete pointer. If the receiving link status field in the frame header of the received inter-satellite transmission frame indicates that the receiving end is in an abnormal receiving state, and the received valid frame sequence number field has been updated but is not equal to the locally recorded confirmed data frame sequence number, a deletion operation is first performed on the transmission buffer, followed by a rollback operation.

[0009] In one embodiment, re-establishing the communication link with the second relay satellite upon detecting an interruption in the communication link with the second relay satellite includes: If no laser signal is detected from the second relay satellite, it is determined that the communication link with the second relay satellite is interrupted. Initiate scanning and recapture, and continuously send inter-satellite transmission frames with the frame type of idle frames. The receive link status field in the frame header of the inter-satellite transmission frame is configured to an abnormal state. If the laser signal from the second relay satellite is successfully reacquired and demodulated, the receive link status field and the receive valid frame sequence number field in the successfully demodulated receive frame are parsed. Perform at least one of deletion and rollback operations on the transmit buffer based on at least one of the parsed receive link status field and receive valid frame sequence number field; Send an inter-satellite transmission frame of type idle frame to the second relay satellite, wherein the receive link status field in the frame header of the inter-satellite transmission frame is configured to normal status; If the receive link status field of the inter-satellite transmission frame returned by the second relay satellite is detected to be in a normal state, it is determined that the communication link with the second relay satellite has been successfully established.

[0010] In one embodiment, re-establishing the communication link with the second relay satellite upon detecting an interruption in the communication link with the second relay satellite includes: If the laser signal of the second relay satellite is detected, but the data in the laser signal cannot be demodulated, it is determined that the communication link with the second relay satellite is interrupted. Restart the demodulator and send an inter-satellite transmission frame of type idle frame to the second relay satellite. The receive link status field in the frame header of the inter-satellite transmission frame is configured to an abnormal reception status. The laser signal from the second relay satellite is demodulated, and the receive link status field and the receive valid frame sequence number field in the successfully demodulated receive frame are parsed. Perform a rollback operation on the transmit buffer based on the parsed valid received frame sequence number field; The inter-satellite transmission frame whose transmission frame type is determined to be an idle frame or a valid frame based on the parsed receive link status field, and the receive link status field in the frame header of the inter-satellite transmission frame is configured to normal receive status. The inter-satellite transmission frame is sent to the second relay satellite to re-establish the communication link with the second relay satellite.

[0011] In one embodiment, re-establishing the communication link with the second relay satellite upon detecting an interruption in the communication link with the second relay satellite includes: If the laser signal from the second relay satellite is received and successfully demodulated, and the receive link status field in the successfully demodulated receive frame is in an abnormal receive state, then the communication link with the second relay satellite is determined to be interrupted. Perform at least one of deletion and rollback operations based on the received valid frame sequence number field in the received frame; Send an inter-satellite transmission frame of type idle frame to the second relay satellite, wherein the receive link status field in the frame header of the inter-satellite transmission frame is configured as abnormal reception status; If the receive link status field of the inter-satellite transmission frame returned by the second relay satellite is detected to be in a normal state, it is determined that the communication link with the second relay satellite has been successfully established.

[0012] In one embodiment, the minimum storage capacity of the transmit buffer is determined by the following formula: , in, This represents the calculated minimum storage capacity of the transmit buffer, in bytes. This indicates the distance between the first relay satellite and the second relay satellite, in meters. This indicates the code rate of communication between the first relay satellite and the second relay satellite, measured in bits per second. The speed of light is expressed in meters per second. This represents the time interval between when data is read from the transmit buffer and when it is modulated and transmitted, expressed in seconds. This represents the time interval, in seconds, between when the laser communication payload receives the laser signal and when the receive link status field is demodulated. Indicates the frame length of the inter-satellite transmission frame, in bytes; This indicates the length of user data in an inter-satellite transmission frame, in bytes. This indicates rounding up to the nearest integer.

[0013] In one embodiment, the minimum number of bits in the data frame sequence number field of the frame header is: , in, The minimum number of bits in the data frame sequence number field of the frame header; This indicates the minimum storage capacity of the transmit buffer, in bytes. This indicates the length of user data in an inter-satellite transmission frame, measured in bytes.

[0014] Secondly, this application also provides an inter-satellite laser communication link resuming device, which is applied to the laser communication payload of a first relay satellite acting as the data sender in inter-satellite laser communication. The laser communication payload has a transmission buffer, and the device includes: The data storage module is used to store the user data stream to be transmitted in the transmission buffer; The data reading module is used to read data from the transmission buffer according to a preset data length, assemble it into an inter-satellite transmission frame, and send the inter-satellite transmission frame to the second relay satellite when the communication link connection with the second relay satellite is confirmed to be normal. The inter-satellite transmission frame has a frame header for characterizing data attributes and current status. The frame header includes a data type field, a data frame sequence number field, a receiving link status field, and a received valid frame sequence number field. The monitoring module is used to monitor the inter-satellite transmission frames from the second relay satellite in real time, and to perform corresponding pointer operations on the transmission buffer to determine the pointer position based on at least one of the receive link status field and the receive valid frame sequence number field in the frame header of the received inter-satellite transmission frame. The data resume module is used to re-establish the communication link with the second relay satellite when an interruption is detected; and to determine the starting position of data transmission based on the received valid frame sequence number field in the frame header of the inter-satellite transmission frame from the second relay satellite and the pointer position, thereby realizing data resume transmission from the breakpoint.

[0015] Thirdly, this application also provides a communication device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method described in the first aspect.

[0016] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect.

[0017] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method described in the first aspect above.

[0018] The aforementioned inter-satellite laser communication link interruption resumption method, apparatus, communication equipment, computer-readable storage medium, and computer program product achieve refined control of inter-satellite laser communication by designing four key fields—data type, data frame sequence number, receiving link status, and received valid frame sequence number—in the frame header of the inter-satellite transmission frame, combined with a dual-pointer management mechanism of read and delete pointers in the transmission buffer. Furthermore, after the link interruption is restored, the starting position for data transmission is re-determined based on the received valid frame sequence number field and the pointer position in the received frame, enabling data transmission to continue from the point of interruption. This maximizes the data integrity and continuity of inter-satellite laser communication, effectively improving the data relay service quality and reliability of the relay satellite constellation. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a diagram illustrating the application environment of an inter-satellite laser communication link reconnection method in one embodiment. Figure 2 This is a flowchart illustrating a method for resuming inter-satellite laser communication after a communication link is lost in one embodiment. Figure 3 This is a schematic diagram of the structure of an inter-satellite transmission frame in one embodiment; Figure 4 This is a schematic diagram of the assembly of inter-satellite transmission frames in one embodiment; Figure 5 This is a schematic diagram of the pointer to the send buffer in one embodiment; Figure 6 This is a flowchart illustrating the steps for resuming transmission after a connection failure in one embodiment. Figure 7 This is a flowchart illustrating the steps for resuming transmission after a connection failure in one embodiment. Figure 8This is a flowchart illustrating the steps for resuming transmission after a connection failure in one embodiment. Figure 9 This is a structural block diagram of an inter-satellite laser communication link reconnection device in one embodiment; Figure 10 This is an internal structure diagram of a communication device in one embodiment. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0022] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0023] The inter-satellite laser communication link resuming method provided in this application embodiment can be applied to, for example... Figure 1 The diagram illustrates a scenario where relay satellite A and relay satellite B relay data via an inter-satellite laser communication link. For example... Figure 1 As shown, low-Earth orbit satellites 1, 2, and 3 can transmit data to relay satellite A via laser or microwave communication. Relay satellite A multiplexes the data received from multiple user satellites and forwards it to relay satellite B via an inter-satellite laser communication link. Relay satellite B then multiplexes the received data along with data from low-Earth orbit satellites 4 and 5 and transmits it to a ground terminal station via a satellite-to-ground microwave communication link. The ground terminal station separates the data and transmits it to each user center via a terrestrial network. Since the data transmitted from relay satellite A to relay satellite B is a mixed byte stream of data from different user satellites, an interruption in the inter-satellite laser communication link will result in simultaneous data corruption from multiple user satellites, severely impacting the relay service quality. Therefore, this application designs an interoperability protocol and a dual-pointer management mechanism for the transmit buffer in the laser communication payload of the relay satellite. This allows data transmission to continue from the point of interruption after the communication link is interrupted and restored, thereby ensuring the integrity and continuity of data transmission.

[0024] In one exemplary embodiment, such as Figure 2 As shown, a method for resuming inter-satellite laser communication after a link break is provided. This method is applied to the first relay satellite (e.g., the data sender) in inter-satellite laser communication. Figure 1Taking the laser communication payload of relay satellite A as an example, the method specifically includes the following steps: Step 202: Store the user data stream to be transmitted in the sending buffer.

[0025] The transmission buffer can be a built-in memory of the laser communication payload of the first relay satellite, which acts as the data sender. It stores user data transmitted as a byte stream from the routing payload of the first relay satellite, i.e., the user data stream to be transmitted. In this embodiment, to enable resume transmission after a connection failure, the user data stream to be transmitted is stored in the transmission buffer, and data is then read from the transmission buffer and transmitted when data is sent.

[0026] Step 204: If the communication link with the second relay satellite is confirmed to be normal, read data from the transmission buffer according to the preset data length, assemble it into an inter-satellite transmission frame, and send the inter-satellite transmission frame to the second relay satellite.

[0027] Inter-satellite transmission frames refer to data frames transmitted between relay satellites in this application, the total length of which remains fixed during communication. For example, such as... Figure 3 As shown, an inter-satellite transmission frame includes a frame synchronization word, a frame header, a data field, and a checksum. The frame header is the core of the retransmission control logic in this application, and it can specifically include four key fields: a data type field, a data frame sequence number field, a receive link status field, and a received valid frame sequence number field.

[0028] For example, the data type field is used to characterize the frame type of the corresponding inter-satellite transmission frame, which may include a data frame or an idle frame. The length of the data type field can be 1 bit. For example, when the corresponding inter-satellite transmission frame is a valid data frame, this field can be set to 0; when the corresponding inter-satellite transmission frame is an idle frame, this field can be set to 1.

[0029] The data frame sequence number field is used to identify the frame sequence number of the corresponding inter-satellite transmission frame. Its length is N bits. For valid data frames, the data frame sequence number starts from 1 and increments sequentially using a circular counting method, with a maximum count value of (2^N). N -1); for idle frames, the data frame sequence number is fixed at 0.

[0030] The receive link status field is used to characterize the reception status of the laser communication payload itself, i.e., the relay satellite that sent the inter-satellite transmission frame. The reception status includes normal reception status and abnormal reception status. The length is, for example, 1 bit, and it indicates whether the user's laser communication payload can stably receive and demodulate the laser signal sent by the other party. When normal reception and demodulation are possible, this field is set to 1; when normal reception and demodulation are not possible, this field is set to 0.

[0031] The Received Valid Frame Sequence Number field is used to identify the sequence number of the last data frame sent by the other end that has been acknowledged as received. It is also N bits long, the same as the Data Frame Sequence Number field. This field is used to fill in the sequence number of the most recent valid data frame sent by the other party that has been acknowledged as received, thus providing feedback to the other party that data has been correctly received. If no valid data frame has been received after the communication task begins, this field is set to 0; once a valid data frame is received, the sequence number of the most recently received valid data frame is continuously filled in until the communication task ends.

[0032] In a scenario, such as Figure 4 As shown, data is read from the transmission buffer according to a preset data length and assembled into an inter-satellite transmission frame. Specifically, this may include: reading user data of a preset data length starting from the read pointer of the transmission buffer and filling it into the corresponding data field. The frame header is determined based on the user data and the current state (see reference). Figure 3 In the illustrated embodiment, the frame header (of fixed length) is used to characterize the data attributes and current state encapsulation information of the inter-satellite transmission frame. The frame header and user data are concatenated to obtain an uncoded transmission frame. Forward error correction coding (e.g., Low-Density Parity-Check (LDPC) or Reed-Solomon code, RS) is performed on the uncoded transmission frame to obtain a parity bit of a first fixed length. Then, the uncoded transmission frame and the parity bit are concatenated to obtain a coded transmission frame. If a small number of bit errors occur in the inter-satellite transmission frame due to noise during transmission, the demodulator can detect and correct these errors using the parity bit information. Finally, a second fixed-length frame synchronization word (used to complete boundary segmentation of the inter-satellite transmission frame in the demodulated bitstream) is appended to the header of the coded transmission frame to obtain the inter-satellite transmission frame. This inter-satellite transmission frame can then be modulated onto a laser beam and transmitted to a second relay satellite. The first and second fixed lengths can be configured according to actual needs. For example, the first fixed length is typically 1024 bits, and the second fixed length is typically 32 bits.

[0033] Understandably, the demodulation process of the second relay satellite is the reverse. Specifically, after the second relay satellite demodulates the received beam to obtain the bit stream, it first completes the segmentation of the inter-satellite transmission frame according to the frame synchronization word; then, it removes the frame synchronization word from the frame header to obtain the encoded transmission frame; next, it uses the decoding algorithm corresponding to the encoding algorithm (such as LDPC decoding) to perform error correction processing on the encoded transmission frame; after error correction is completed, it extracts user data from a fixed position in the encoded transmission frame, and at the same time, it parses the working status information of the laser communication payload of the first relay satellite (including data type, data frame sequence number, receiving link status, received valid frame sequence number, etc.) from the frame header, and performs corresponding buffer management or status feedback operations accordingly.

[0034] In this embodiment, the data sender being the first relay satellite can be... Figure 1 In the middle relay satellite A, the data receiver can be the second relay satellite. Figure 1 Taking relay satellite B as an example. The laser communication payload of relay satellite A stores the user data stream to be transmitted in its own transmission buffer. When it is confirmed that the communication link with the laser communication payload of the second relay satellite, i.e., relay satellite B, is normal (i.e., both sides can detect the laser signal from the other end and can successfully demodulate it), it can read data from the transmission buffer according to a preset data length and assemble it into an inter-satellite transmission frame (the assembly process can be parameterized). Figure 3 , Figure 4 And then, it sends the inter-satellite transmission frame to relay satellite B.

[0035] Step 206: Monitor the inter-satellite transmission frames from the second relay satellite in real time. Based on at least one of the receive link status field and the receive valid frame sequence number field in the frame header of the received inter-satellite transmission frame, perform corresponding pointer operations on the transmission buffer to determine the pointer position.

[0036] In this embodiment, fine-grained management of the transmission buffer is achieved by maintaining two pointers to the transmission buffer. Exemplarily, these pointers include a read pointer Pc and a delete pointer Ps. The read pointer Pc always points to the starting position of the user data to be read in the transmission buffer. When a read operation is performed, the laser communication payload reads a fixed-length (e.g., Lu) segment of user data starting from the address pointed to by the read pointer Pc, assembles it into a valid data frame, and sends it. Then, the read pointer Pc is moved forward by Lu bytes, making it point to the starting position of the next data to be read.

[0037] The deletion pointer Ps always points to the starting position of the user data to be deleted in the transmit buffer. When a deletion operation is performed, the data that has been correctly received is deleted starting from the address pointed to by the deletion pointer Ps, based on the sequence number of the valid frame that has been acknowledged by the other party. Then, the deletion pointer Ps is moved forward to the new position to be deleted.

[0038] Based on the aforementioned dual-pointer structure, this application defines three core operations for the transmit buffer. Specifically, by real-time monitoring of inter-satellite transmission frames from the second relay satellite, and based on at least one of the receive link status field and the received valid frame sequence number field in the frame header of the received inter-satellite transmission frame, corresponding pointer operations are performed on the transmit buffer to determine the pointer position.

[0039] In one scenario, if the receiver link status field in the frame header of a received inter-satellite transmission frame indicates that the receiving end is in a normal receiving state, a read operation can be performed on the transmit buffer. For example, when the "Receive Link Status" field in the frame header of a received inter-satellite transmission frame from a second relay satellite is "1" (i.e., the receiving end can receive normally), a read operation is performed. In this case, such as... Figure 5 As shown, the laser communication payload reads user data of length Lu from the read pointer Pc, combines it with the real-time assembled frame header (containing information such as the incremented data frame sequence number C2) to form an uncoded transmission frame, and then modulates and transmits it after encoding and adding a frame synchronization word. After transmission is completed, the read pointer Pc is updated to Pc+Lu.

[0040] In one scenario, if the received valid frame sequence number field in the frame header of a received inter-satellite transmission frame is updated and is no longer equal to the locally recorded confirmed data frame sequence number, a deletion operation is performed on the transmit buffer. For example, ... Figure 5 As shown, when the "Received Valid Frame Sequence Number" field in the frame header of a received inter-satellite transmission frame is updated to C1, and C1 is not equal to the currently recorded received data frame sequence number C0, a deletion operation is performed. At this time, the difference (C1-C0) is calculated, and user data of length (C1-C0)×Lu is deleted starting from the address pointed to by the deletion pointer Ps. Then, the deletion pointer Ps is moved forward by (C1-C0)×Lu bytes. After the update, the valid data frame sequence number corresponding to the address pointed to by the deletion pointer Ps is C1+1, which becomes the new C0. Through the deletion operation, valid data frames whose sequence numbers from the original C0+1 to C1 have been correctly received and acknowledged by the other party are deleted. Therefore, this part of the data can be removed from the buffer, freeing up storage space.

[0041] In one scenario, if the receiver is determined to be in an abnormal reception state based on the receive link status field in the frame header of the received inter-satellite transmission frame, a rollback operation is performed on the transmit buffer. For example, ... Figure 5 As shown, when the "Receive Link Status" field in the header of the received inter-satellite transmission frame is "0" (i.e., the other end cannot receive normally), a rollback operation is performed. At this time, the read pointer Pc is assigned the current value of the delete pointer Ps, i.e., Pc = Ps. This means that when sending valid data later, reading will start again from the address pointed to by the delete pointer Ps, so that the data between the delete pointer Ps and the original read pointer Pc (i.e., data that has been sent but has not yet been acknowledged by the other end) is retransmitted, thereby realizing the continuation of data transmission from the link breakpoint.

[0042] In one scenario, if the receiver is determined to be in an abnormal reception state based on the receive link status field in the frame header of the received inter-satellite transmission frame, and the received valid frame sequence number field has been updated but is not equal to the locally recorded confirmed data frame sequence number, a deletion operation is first performed on the transmit buffer, followed by a rollback operation. For example, as follows... Figure 5 As shown, when a received inter-satellite transmission frame simultaneously satisfies the conditions of "received link status" being "0" (i.e., the peer cannot receive normally) and "received valid frame sequence number" C1 not equal to C0, the deletion operation takes precedence over the rollback operation. That is, the deletion operation is performed first, clearing the acknowledged received data from the buffer, and then the rollback operation is performed, thus retransmitting only the data with valid frame sequence numbers from C1+1 to C2, without retransmitting the acknowledged data between C0 and C1. This priority design avoids unnecessary duplicate transmissions and improves transmission efficiency after the link is restored.

[0043] In this embodiment, by monitoring the inter-satellite transmission frames from the second relay satellite in real time, and upon detecting an inter-satellite transmission frame from the second relay satellite, the corresponding pointer operation is performed on the transmission buffer based on at least one of the receive link status field and the receive valid frame sequence number field in the frame header of the inter-satellite transmission frame, so as to determine the pointer position.

[0044] Step 208: After the link interruption is restored, the starting position of data transmission is determined according to the received valid frame sequence number field and pointer position in the frame header of the inter-satellite transmission frame from the second relay satellite, so as to realize the data resume transmission from the breakpoint.

[0045] Specifically, if a communication link with the second relay satellite is detected to be interrupted, the communication link with the second relay satellite is re-established. After the link is restored, the starting position of data transmission is determined according to the received valid frame sequence number field and pointer position in the frame header of the inter-satellite transmission frame from the second relay satellite, so as to realize the data resume transmission from the point of interruption.

[0046] In the aforementioned method for resuming inter-satellite laser communication after a link break, four key fields—data type, data frame sequence number, receiving link status, and received valid frame sequence number—are designed in the frame header of the inter-satellite transmission frame. Combined with a dual-pointer management mechanism (read and delete pointers) for the transmit buffer, this achieves refined control of laser communication between relay satellites. Furthermore, after the link is restored, the starting position for data transmission is redefined based on the received valid frame sequence number field and the pointer position in the received frame, enabling data transmission to resume from the point of interruption. This maximizes the data integrity and continuity of inter-satellite laser communication, effectively improving the data relay service quality and reliability of the relay satellite constellation.

[0047] In an exemplary embodiment, in order to ensure the effective operation of the disconnection resumption mechanism, the transmission buffer configured in the laser communication payload must meet the minimum capacity requirement, and the number of bits N in the data frame sequence number field must ensure that the sequence number will not repeat cyclically within the maximum buffer time.

[0048] For example, considering the transmission latency caused by inter-satellite link distance and device processing latency, the capacity of the send buffer needs to be sufficient to cover the amount of data that can be sent between the time the data is sent and the time an acknowledgment is received. Therefore, the minimum storage capacity of the send buffer... The following equation (1) must be satisfied: (1) in, This represents the calculated minimum storage capacity of the transmit buffer, in bytes. This indicates the distance between the first relay satellite and the second relay satellite, in meters. This indicates the code rate of communication between the first relay satellite and the second relay satellite, measured in bits per second. This represents the speed of light, measured in meters per second (m / s). This represents the time interval between when data is read from the transmit buffer and when it is modulated and transmitted, expressed in seconds. This represents the time interval, in seconds, between when the laser communication payload receives the laser signal and when the receive link status field is demodulated. Indicates the frame length of the inter-satellite transmission frame, in bytes; This indicates the length of user data in an inter-satellite transmission frame, in bytes. This indicates rounding up to the nearest integer.

[0049] The physical meaning of equation (1) above is that the transmission buffer must at least accommodate all the transmitted but unacknowledged data accumulated within the round-trip optical propagation delay, the transmitting end processing delay, and the receiving end processing delay. Here, R / C×2 represents the time required for the laser signal to propagate between satellites. and They respectively characterize the transmission processing delay and the reception processing delay; B / 8 converts the code rate to the byte rate; This reflects the effective proportion of user data in inter-satellite transmission frames.

[0050] Since the data frame sequence number field uses a cyclic incrementing count, in order to avoid sequence number confusion (i.e., overlap of old and new data sequence numbers) during the cyclic use of the sending buffer, which would make the data frames indistinguishable, the number of bits N in the data frame sequence number field needs to satisfy the following relationship, as shown in equation (2): (2) in, The minimum number of bits in the data frame sequence number field of the frame header; This indicates the minimum storage capacity of the transmit buffer, in bytes. This indicates the length of user data in an inter-satellite transmission frame, measured in bytes.

[0051] For example, if a certain communication scenario has the following parameters: the distance R between two relay satellites is 32,000 km; the transmission processing delay... and receiving / processing delay All are 10 ms, the communication code rate B is 5 Gbps, the inter-satellite transmission frame length L is 1024 bytes, and the user data length is... The estimate is 880 bytes. Therefore, according to equation (1) above, the minimum storage capacity of the send buffer can be calculated. It is approximately 125 MB. Further substituting into equation (2), we can calculate that the minimum number of bits N in the data frame sequence number field is 18 bits. Considering engineering margins and latency jitter in extreme cases, in practical engineering applications, it is recommended that the calculated... and On top of that, a certain amount of redundancy (e.g., 10%-20%) is added to cope with the impact of track perturbation or processing delay jitter, so as to ensure the uniqueness of the data frame sequence number in long-term communication tasks and ensure the effective operation of the link breakage resumption mechanism.

[0052] To further illustrate the principles of this application, the following section details the inter-satellite laser communication link interruption and resumption process based on different causes of link interruption. For example, the following description uses relay satellite A as the data sender (first relay satellite) and relay satellite B as the data receiver (second relay satellite).

[0053] In one scenario, let's take a bidirectional link interruption caused by laser beam deviation as an example. Because the laser beam divergence angle is extremely narrow, micro-vibrations in the satellite platform caused by factors such as solar panel rotation and attitude adjustments can cause the laser beam to deviate from the receiving target. Furthermore, since the transmitting and receiving optical paths within the laser communication payload are usually parallel and coincident, if one side fails to receive a light signal, it can be inferred that the other side has also failed to receive a light signal, i.e., a bidirectional communication link interruption. Figure 6 As shown, the process for resuming a broken connection in this scenario includes the following steps: Step 602: If no laser signal from the second relay satellite is detected, it is determined that the communication link with the second relay satellite is interrupted.

[0054] Regardless of the reason for the beam deviation, if the laser communication payload of relay satellite A fails to detect the laser signal sent by relay satellite B, it can be determined that the communication link has been interrupted in both directions. That is, at this time, the laser communication payload of relay satellite B is also unlikely to receive the laser signal sent by relay satellite A, so it is necessary to prepare to retransmit some data.

[0055] Step 604: Start scanning and recapture, and continuously send inter-satellite transmission frames with the frame type of idle frames.

[0056] In this case, the receive link status field in the frame header of the inter-satellite transmission frame is configured to an abnormal state. The laser communication payload of relay satellite A initiates a scan and reacquisition procedure while continuously transmitting idle frames (i.e., the data type of the inter-satellite transmission frame is an idle frame). In the frame header of this idle frame, the data type field is set to 1 (indicating an idle frame), the receive link status field is set to 0 (indicating that the receiving end is currently unable to receive normally), the data frame sequence number field is set to 0, and the received valid frame sequence number field is filled with the data frame sequence number of the most recently received valid data frame from relay satellite B that has been recorded locally.

[0057] Step 606: If the laser signal from the second relay satellite is successfully reacquired and demodulated, the receive link status field and the receive valid frame sequence number field in the successfully demodulated receive frame are parsed.

[0058] Step 608: Perform at least one of the following operations on the transmit buffer: deletion operation and rollback operation, based on at least one of the parsed receive link status field and receive valid frame sequence number field.

[0059] Relay satellite A re-acquires the laser beam from relay satellite B and successfully demodulates it. At this time, relay satellite B typically sends an idle frame, and the receive link status field in its frame header is 0. Relay satellite A parses this idle frame and performs deletion and rollback operations based on the received valid frame sequence number field to determine the range of data that needs to be retransmitted.

[0060] Step 610: Send an inter-satellite transmission frame of type idle frame to the second relay satellite.

[0061] Relay satellite A continues to send idle frames to relay satellite B, but sets the receive link status field in its frame header to 1 (indicating that it can currently receive data normally), thus conveying to relay satellite B that it can now receive data normally.

[0062] Step 612: If the receive link status field of the inter-satellite transmission frame returned by the second relay satellite is detected to be in a normal state, it is determined that the communication link with the second relay satellite has been successfully established.

[0063] Step 614: Resume data transmission based on the re-established communication link.

[0064] Relay satellite A continues to receive and demodulate the inter-satellite transmission frames returned by relay satellite B. If its receive link status field is parsed to be 1, it indicates that relay satellite B can receive data normally. Therefore, it can be determined that a communication link with the second relay satellite has been successfully established. At this time, relay satellite A stops sending idle frames and instead performs a read operation. That is, starting from the read pointer Pc position in the transmit buffer after the rollback operation, it reads user data and assembles it into a valid data frame for modulation and transmission. This achieves data resumption from the breakpoint.

[0065] In one scenario, let's take a one-way reception interruption caused by a demodulation anomaly on the receiving side as an example. This scenario refers to a situation where the laser communication payload of relay satellite A can normally track the laser signal sent by relay satellite B (i.e., optical signal acquisition and tracking are normal), but cannot properly demodulate the modulated data on the beam. At this time, the communication link between the transmitting and receiving sides is interrupted unidirectionally. This anomaly may be caused by a fault in either the receiving demodulator or the modulator of the receiving satellite. Figure 7 As shown, the process for resuming a broken connection in this scenario includes the following steps: Step 702: If the laser signal of the second relay satellite is detected, but the data in the laser signal cannot be demodulated, it is determined that the communication link with the second relay satellite is interrupted.

[0066] Since the laser communication payload of relay satellite A confirmed that it could not demodulate the data normally, it was determined that the transmission link between the other party and the receiving party was interrupted in one direction, that is, the communication link with the second relay satellite was interrupted.

[0067] Step 704: Restart the demodulator and send an inter-satellite transmission frame of type idle frame to the second relay satellite.

[0068] While restarting the demodulator, relay satellite A continuously transmits idle frames. In the frame header of this idle frame, the data type field is set to 1, the receive link status field is set to 0 (indicating a receiving error on its own end), the data frame sequence number field is set to 0, and the received valid frame sequence number field is filled with the sequence number of the most recently received valid data frame from relay satellite B, which is recorded locally.

[0069] Step 706: Demodulate the laser signal from the second relay satellite and parse the receive link status field and the receive valid frame sequence number field in the successfully demodulated receive frame.

[0070] Step 708: Perform a rollback operation on the transmit buffer based on the parsed valid received frame sequence number field.

[0071] After relay satellite A successfully restarts its demodulator, it re-demodulates the laser signal from relay satellite B. At this point, it determines whether to perform a rollback operation based on the valid received frame sequence number in the idle frame header sent by relay satellite B: if the valid received frame sequence number is equal to the sequence number of the last valid frame sent by relay satellite A, it indicates that relay satellite B has correctly received all transmitted data before the link was lost, and no rollback is needed; otherwise, the read pointer Pc is rolled back to the buffer position corresponding to the next frame after the valid received frame sequence number.

[0072] Step 710: Determine whether the transmitted frame type is an idle frame or a valid frame based on the parsed receive link status field.

[0073] In particular, the receive link status field in the frame header of the inter-satellite transmission frame is configured to be in normal receive status.

[0074] Step 712: Send an inter-satellite transmission frame to the second relay satellite to re-establish the communication link with the second relay satellite.

[0075] Step 714: Resume data transmission based on the re-established communication link.

[0076] Relay satellite A determines the frame type to send based on the receive link status field in the frame header of the inter-satellite transmission frame sent by relay satellite B: if the receive link status is 0, it continues to send idle frames; if it is 1, it sends valid data frames. Simultaneously, relay satellite A sets the receive link status in the frame header of its transmitted frame to 1, indicating to relay satellite B that it has restored normal reception capability, thereby re-establishing the communication link with the second relay satellite and resuming data transmission.

[0077] In one scenario, let's take a one-way transmission interruption caused by a demodulation anomaly on the other end as an example. This scenario refers to a situation where relay satellite A can normally receive and demodulate the laser signal sent by relay satellite B, but analysis reveals that the receive link status field in the frame header of the inter-satellite transmission frame sent by relay satellite B is 0, indicating that relay satellite B cannot normally receive and demodulate the data sent by itself; that is, the communication link between the sender and receiver is unidirectionally interrupted. For example... Figure 8 As shown, the process for resuming a broken connection in this scenario includes the following steps: Step 802: If the laser signal from the second relay satellite is received and demodulated successfully, and the receive link status field in the successfully demodulated receive frame is in an abnormal receive state, then it is determined that the communication link with the second relay satellite is interrupted.

[0078] After successfully demodulating the inter-satellite transmission frame sent by relay satellite B, relay satellite A analyzes its frame header. If it finds that the receive link status field is 0, it can be determined that relay satellite B has a demodulation error and cannot receive its own data normally.

[0079] Step 804: Perform at least one of a deletion operation and a rollback operation based on the received valid frame sequence number field in the received frame.

[0080] Relay satellite A performs a deletion and / or rollback operation on the received valid frame sequence number field in the parsed frame header to update the pointer state of the transmit buffer.

[0081] Step 806: Send an inter-satellite transmission frame of type idle frame to the second relay satellite.

[0082] Relay satellite A stops sending valid data frames and starts sending idle frames instead. In the frame header of this idle frame, the data type field is set to 0, the receive link status field is set to 1, the data frame sequence number field is set to 0, and the received valid frame sequence number field is filled with the sequence number of the most recently received valid data frame from relay satellite B, which is recorded locally.

[0083] Step 808: If the receive link status field of the inter-satellite transmission frame returned by the second relay satellite is detected to be in a normal state, it is determined that the communication link with the second relay satellite has been successfully established.

[0084] Step 810: Resume data transmission based on the re-established communication link.

[0085] Once relay satellite B completes its demodulator restart and returns to normal operation, the receive link status field in the frame header of the inter-satellite transmission frame it sends to relay satellite A will be set to 1. Upon learning of this status, relay satellite A, starting from the rolled-back read pointer Pc position in the transmit buffer, reads user data, assembles it into a valid data frame, and sends it to relay satellite B, thus achieving resume transmission.

[0086] It should be noted that, using the link interruption resumption method of this application, after the link is restored, the data transmitted from the interruption point may contain data that has been correctly received by the other party but has not yet been overwritten by the local deletion pointer, or duplicate data frames due to link state interaction delays, thus generating duplicate frames. For these duplicate frames, the ground terminal can perform deduplication based on the data frame sequence number after receiving all relay data, or they can be removed through a frame sequence number detection mechanism at a higher-layer protocol (such as the network layer or application layer). This design simplifies the processing logic of the onboard laser communication payload, reduces the computational burden and power consumption of the onboard equipment, and conforms to the lightweight design principle of relay satellite payloads.

[0087] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0088] Based on the same inventive concept, this application also provides an inter-satellite laser communication link resumption device for implementing the above-mentioned inter-satellite laser communication link resumption method. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more inter-satellite laser communication link resumption device embodiments provided below can be found in the limitations of the inter-satellite laser communication link resumption method above, and will not be repeated here.

[0089] In one exemplary embodiment, such as Figure 9 As shown, an inter-satellite laser communication link resuming device is provided. This device is applied to the laser communication payload of the first relay satellite acting as the data sender in inter-satellite laser communication. The laser communication payload has a transmission buffer and includes: a data storage module 902, a data reading module 904, a monitoring module 906, and a data resuming module 908, wherein: Data storage module 902 is used to store the user data stream to be transmitted in the transmission buffer; The data reading module 904 is used to read data from the transmission buffer according to a preset data length and assemble it into an inter-satellite transmission frame when it is determined that the communication link connection with the second relay satellite is normal, and then send the inter-satellite transmission frame to the second relay satellite. The inter-satellite transmission frame has a frame header for characterizing data attributes and current status. The frame header includes a data type field, a data frame sequence number field, a receiving link status field, and a received valid frame sequence number field. The monitoring module 906 is used to monitor the inter-satellite transmission frames from the second relay satellite in real time, and to perform corresponding pointer operations on the transmission buffer to determine the pointer position based on at least one of the receive link status field and the receive valid frame sequence number field in the frame header of the received inter-satellite transmission frame. The data resume module 908 is used to re-establish the communication link with the second relay satellite when an interruption of the communication link with the second relay satellite is detected; and to determine the starting position of data transmission based on the received valid frame sequence number field in the frame header of the inter-satellite transmission frame from the second relay satellite and the pointer position, so as to realize the data resume transmission from the breakpoint.

[0090] In an exemplary embodiment, the data type field is used to characterize the frame type of the corresponding inter-satellite transmission frame, the frame type including a data frame or an idle frame; the data frame sequence number field is used to characterize the frame sequence number of the corresponding inter-satellite transmission frame; the receive link status field is used to characterize its own receive status, the receive status including normal receive status or abnormal receive status; the received valid frame sequence number field is used to characterize the data frame sequence number of the last frame sent by the peer that it has confirmed has been received.

[0091] In an exemplary embodiment, the data reading module is further configured to: read user data of a preset data length starting from the read pointer of the sending buffer; determine a frame header based on the user data and the current state; concatenate the frame header and the user data to obtain an uncoded transmission frame; perform forward error correction coding on the uncoded transmission frame to obtain a check bit with a first fixed length; concatenate the uncoded transmission frame and the check bit to obtain a coded transmission frame; and append a frame synchronization word of a second fixed length to the header of the coded transmission frame to obtain the inter-satellite transmission frame.

[0092] In an exemplary embodiment, the monitoring module is further configured to: perform a read operation on the transmit buffer when it is determined that the peer is in a normal receiving state based on the receive link status field in the frame header of the received inter-satellite transmission frame; the read operation involves reading user data of a preset data length from the read pointer of the transmit buffer, assembling it into an inter-satellite transmission frame, and moving the read pointer to update its position; and perform a delete operation on the transmit buffer when it is determined that the received valid frame sequence number field in the frame header of the received inter-satellite transmission frame has been updated and is not equal to the locally recorded confirmed data frame sequence number; the delete operation involves reading user data of a preset data length from the read pointer of the transmit buffer, assembling it into an inter-satellite transmission frame, and moving the read pointer to update its position; and perform a delete operation on the transmit buffer when it is determined that the received valid frame sequence number field in the frame header of the received inter-satellite transmission frame has been updated and is not equal to the locally recorded confirmed data frame sequence number. The system begins deleting confirmed data from the buffer's deletion pointer and moves the deletion pointer to update its position. If, based on the receive link status field in the frame header of the received inter-satellite transmission frame, the receiving end is determined to be in an abnormal reception state, a rollback operation is performed on the transmission buffer. The rollback operation involves reverting the read pointer to the position of the deletion pointer. If, based on the receive link status field in the frame header of the received inter-satellite transmission frame, the receiving end is determined to be in an abnormal reception state, and the received valid frame sequence number field is updated but not equal to the locally recorded confirmed data frame sequence number, a deletion operation is first performed on the transmission buffer, followed by a rollback operation.

[0093] In an exemplary embodiment, the data retransmission module is further configured to: determine that the communication link with the second relay satellite is interrupted if no laser signal from the second relay satellite is detected; initiate scan recapture and continuously transmit inter-satellite transmission frames of type idle frames, wherein the receive link status field in the frame header of the inter-satellite transmission frame is configured to an abnormal state; if the laser signal from the second relay satellite is recaptured and demodulated successfully, parse the receive link status field and the received valid frame sequence number field in the successfully demodulated received frame; perform at least one of a deletion operation and a rollback operation on the transmission buffer based on at least one of the parsed receive link status field and the received valid frame sequence number field; transmit inter-satellite transmission frames of type idle frames to the second relay satellite, wherein the receive link status field in the frame header of the inter-satellite transmission frame is configured to a normal state; and determine that the communication link with the second relay satellite has been successfully established if the receive link status field of the inter-satellite transmission frame transmitted back by the second relay satellite is in a normal state.

[0094] In an exemplary embodiment, the data retransmission module is further configured to: determine that the communication link with the second relay satellite is interrupted when a laser signal from the second relay satellite is detected but the data in the laser signal cannot be demodulated; restart the demodulator and send an inter-satellite transmission frame of type idle frame to the second relay satellite, wherein the receive link status field in the frame header of the inter-satellite transmission frame is configured to an abnormal reception state; demodulate the laser signal from the second relay satellite and parse the receive link status field and the receive valid frame sequence number field in the successfully demodulated receive frame; perform a rollback operation on the transmission buffer according to the parsed receive valid frame sequence number field; determine whether to send an inter-satellite transmission frame of type idle frame or valid frame according to the parsed receive link status field, wherein the receive link status field in the frame header of the inter-satellite transmission frame is configured to a normal reception state; and send the inter-satellite transmission frame to the second relay satellite to re-establish the communication link with the second relay satellite.

[0095] In an exemplary embodiment, the data retransmission module is further configured to: upon receiving and successfully demodulating the laser signal from the second relay satellite, if the receive link status field in the successfully demodulated receive frame is in an abnormal receive state, determine that the communication link with the second relay satellite is interrupted; perform at least one of a deletion operation and a rollback operation based on the received valid frame sequence number field in the receive frame; send an inter-satellite transmission frame of type idle frame to the second relay satellite, wherein the receive link status field in the frame header of the inter-satellite transmission frame is configured to an abnormal receive state; and determine that a communication link with the second relay satellite has been successfully established if the receive link status field of the inter-satellite transmission frame returned by the second relay satellite is in a normal state.

[0096] In an exemplary embodiment, the minimum storage capacity of the transmit buffer is determined by the following formula: , in, This represents the calculated minimum storage capacity of the transmit buffer, in bytes. This indicates the distance between the first relay satellite and the second relay satellite, in meters. This indicates the code rate of communication between the first relay satellite and the second relay satellite, measured in bits per second. The speed of light is expressed in meters per second. This represents the time interval between when data is read from the transmit buffer and when it is modulated and transmitted, expressed in seconds. This represents the time interval, in seconds, between when the laser communication payload receives the laser signal and when the receive link status field is demodulated. Indicates the frame length of the inter-satellite transmission frame, in bytes; This indicates the length of user data in an inter-satellite transmission frame, in bytes. This indicates rounding up to the nearest integer.

[0097] In an exemplary embodiment, the minimum number of bits in the data frame sequence number field of the frame header is: , in, The minimum number of bits in the data frame sequence number field of the frame header; This indicates the minimum storage capacity of the transmit buffer, in bytes. This indicates the length of user data in an inter-satellite transmission frame, measured in bytes.

[0098] Each module in the aforementioned inter-satellite laser communication link reconnection device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0099] In one exemplary embodiment, a communication device is provided, the internal structure of which can be shown in the following diagram. Figure 10 As shown, the communication device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a method for resuming inter-satellite laser communication after a link break. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the communication device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the communication device, or external keyboards, touchpads, or mice, etc.

[0100] Those skilled in the art will understand that Figure 10 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the communication device to which the present application is applied. Specific communication devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0101] In one exemplary embodiment, a communication device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0102] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0103] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0104] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0105] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0106] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0107] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for resuming inter-satellite laser communication after a link break, characterized in that, The method is applied to the laser communication payload of the first relay satellite acting as the data sender in inter-satellite laser communication, wherein the laser communication payload has a transmission buffer, and the method includes: The user data stream to be transmitted is stored in the transmission buffer; If the communication link with the second relay satellite is confirmed to be normal, data is read from the transmission buffer according to the preset data length and assembled into an inter-satellite transmission frame, and the inter-satellite transmission frame is sent to the second relay satellite; the inter-satellite transmission frame has a frame header for characterizing data attributes and current status, and the frame header includes a data type field, a data frame sequence number field, a receiving link status field, and a received valid frame sequence number field; Real-time monitoring of inter-satellite transmission frames from the second relay satellite; and performing corresponding pointer operations on the transmission buffer to determine the pointer position based on at least one of the receive link status field and the receive valid frame sequence number field in the frame header of the received inter-satellite transmission frame. If a communication link with the second relay satellite is detected to be interrupted, the communication link with the second relay satellite is re-established; the starting position of data transmission is determined according to the received valid frame sequence number field in the frame header of the inter-satellite transmission frame from the second relay satellite and the pointer position, so as to realize the data resume transmission from the breakpoint.

2. The method according to claim 1, characterized in that, The data type field is used to characterize the frame type of the corresponding inter-satellite transmission frame, and the frame type includes data frames or idle frames. The data frame sequence number field is used to represent the frame sequence number of the corresponding inter-satellite transmission frame; The receiving link status field is used to characterize its own receiving status, which includes normal receiving status or abnormal receiving status. The received valid frame sequence number field is used to represent the data frame sequence number of the last frame sent by the peer that the receiver has confirmed has been received.

3. The method according to claim 1 or 2, characterized in that, The step of reading data from the transmission buffer according to a preset data length and assembling it into an inter-satellite transmission frame includes: Start reading user data of a preset length from the read pointer of the send buffer; Based on the user data and the current state, a frame header is determined, and the frame header and the user data are concatenated to obtain an uncoded transmission frame. Perform forward error correction coding on the uncoded transmission frame to obtain a check bit with a first fixed length; By concatenating the unencoded transmission frame and the check bit, an encoded transmission frame is obtained; A second fixed-length frame synchronization word is appended to the header of the encoded transmission frame to obtain the inter-satellite transmission frame.

4. The method according to claim 1, characterized in that, The step of performing corresponding pointer operations on the transmit buffer to determine the pointer position based on at least one of the receive link status field and the receive valid frame sequence number field in the frame header of the received inter-satellite transmission frame includes: If the receiving link status field in the frame header of the received inter-satellite transmission frame indicates that the receiving end is in a normal receiving state, a read operation is performed on the transmission buffer. The read operation involves reading user data of a preset data length from the read pointer of the transmission buffer, assembling it into an inter-satellite transmission frame, and moving the read pointer to update its position. If the received valid frame sequence number field in the frame header of the received inter-satellite transmission frame is updated and is not equal to the locally recorded confirmed data frame sequence number, a deletion operation is performed on the transmission buffer. The deletion operation involves deleting confirmed data starting from the deletion pointer in the transmission buffer, moving the deletion pointer, and updating the position of the deletion pointer. If the receiver is determined to be in an abnormal reception state based on the receive link status field in the frame header of the received inter-satellite transmission frame, a rollback operation is performed on the transmit buffer; the rollback operation is to roll back the read pointer to the position of the delete pointer. If the receiving link status field in the frame header of the received inter-satellite transmission frame indicates that the receiving end is in an abnormal receiving state, and the received valid frame sequence number field has been updated but is not equal to the locally recorded confirmed data frame sequence number, a deletion operation is first performed on the transmission buffer, followed by a rollback operation.

5. The method according to claim 1, characterized in that, The step of re-establishing the communication link with the second relay satellite upon detecting an interruption in the communication link includes: If no laser signal is detected from the second relay satellite, it is determined that the communication link with the second relay satellite is interrupted. Initiate scanning and recapture, and continuously send inter-satellite transmission frames with the frame type of idle frames. The receive link status field in the frame header of the inter-satellite transmission frame is configured to an abnormal state. If the laser signal from the second relay satellite is successfully reacquired and demodulated, the receive link status field and the receive valid frame sequence number field in the successfully demodulated receive frame are parsed. Perform at least one of deletion and rollback operations on the transmit buffer based on at least one of the parsed receive link status field and receive valid frame sequence number field; Send an inter-satellite transmission frame of type idle frame to the second relay satellite, wherein the receive link status field in the frame header of the inter-satellite transmission frame is configured to normal status; If the receive link status field of the inter-satellite transmission frame returned by the second relay satellite is detected to be in a normal state, it is determined that the communication link with the second relay satellite has been successfully established.

6. The method according to claim 1, characterized in that, The step of re-establishing the communication link with the second relay satellite upon detecting an interruption in the communication link includes: If the laser signal of the second relay satellite is detected, but the data in the laser signal cannot be demodulated, it is determined that the communication link with the second relay satellite is interrupted. Restart the demodulator and send an inter-satellite transmission frame of type idle frame to the second relay satellite. The receive link status field in the frame header of the inter-satellite transmission frame is configured to an abnormal reception status. The laser signal from the second relay satellite is demodulated, and the receive link status field and the receive valid frame sequence number field in the successfully demodulated received frame are parsed. Perform a rollback operation on the transmit buffer based on the parsed valid received frame sequence number field; The inter-satellite transmission frame whose transmission frame type is determined to be an idle frame or a valid frame based on the parsed receive link status field, and the receive link status field in the frame header of the inter-satellite transmission frame is configured to normal receive status. The inter-satellite transmission frame is sent to the second relay satellite to re-establish the communication link with the second relay satellite.

7. The method according to claim 1, characterized in that, The step of re-establishing the communication link with the second relay satellite upon detecting an interruption in the communication link includes: If the laser signal from the second relay satellite is received and successfully demodulated, and the receive link status field in the successfully demodulated receive frame is in an abnormal receive state, then the communication link with the second relay satellite is determined to be interrupted. Perform at least one of deletion and rollback operations based on the received valid frame sequence number field in the received frame; Send an inter-satellite transmission frame of type idle frame to the second relay satellite, wherein the receive link status field in the frame header of the inter-satellite transmission frame is configured as abnormal reception status; If the receive link status field of the inter-satellite transmission frame returned by the second relay satellite is detected to be in a normal state, it is determined that the communication link with the second relay satellite has been successfully established.

8. The method according to claim 1, characterized in that, The minimum storage capacity of the transmit buffer is determined by the following formula: ， in, This represents the calculated minimum storage capacity of the transmit buffer, in bytes. This indicates the distance between the first relay satellite and the second relay satellite, in meters. This indicates the code rate of communication between the first relay satellite and the second relay satellite, measured in bits per second. The speed of light is expressed in meters per second. This represents the time interval between when data is read from the transmit buffer and when it is modulated and transmitted, in seconds. This represents the time interval, in seconds, between when the laser communication payload receives the laser signal and when the receive link status field is demodulated. Indicates the frame length of the inter-satellite transmission frame, in bytes; This indicates the length of user data in an inter-satellite transmission frame, in bytes. This indicates rounding up to the nearest integer.

9. The method according to claim 8, characterized in that, The minimum number of digits in the data frame sequence number field of the frame header is: ， in, The minimum number of bits in the data frame sequence number field of the frame header; This indicates the minimum storage capacity of the transmit buffer, in bytes. This indicates the length of user data in an inter-satellite transmission frame, measured in bytes.

10. A device for resuming interrupted inter-satellite laser communication transmission, characterized in that, The device is used in inter-satellite laser communication as the laser communication payload of the first relay satellite acting as the data sender. The laser communication payload has a transmission buffer. The device includes: The data storage module is used to store the user data stream to be transmitted in the transmission buffer; The data reading module is used to read data from the transmission buffer according to a preset data length, assemble it into an inter-satellite transmission frame, and send the inter-satellite transmission frame to the second relay satellite when the communication link connection with the second relay satellite is confirmed to be normal. The inter-satellite transmission frame has a frame header for characterizing data attributes and current status. The frame header includes a data type field, a data frame sequence number field, a receiving link status field, and a received valid frame sequence number field. The monitoring module is used to monitor the inter-satellite transmission frames from the second relay satellite in real time, and to perform corresponding pointer operations on the transmission buffer to determine the pointer position based on at least one of the receive link status field and the receive valid frame sequence number field in the frame header of the received inter-satellite transmission frame. The data resume module is used to re-establish the communication link with the second relay satellite when an interruption is detected; and to determine the starting position of data transmission based on the received valid frame sequence number field in the frame header of the inter-satellite transmission frame from the second relay satellite and the pointer position, thereby realizing data resume transmission from the breakpoint.

11. A communication device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 9.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 9.

13. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 9.

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