Inter-satellite laser communication method and system, computer program product and storage medium

Abstract

This application provides an inter-satellite laser communication method and system, a computer program product, and a storage medium. The method includes: a first communication satellite generating a first physical frame based on a first inter-satellite link overhead; when a second communication satellite receives the first physical frame with the first inter-satellite link overhead, it adjusts its own beam focus according to the satellite trajectory information of the first communication satellite to ensure that the beam tracks the first communication satellite, effectively overcoming the optical path deviation caused by satellite motion and improving the robustness of inter-satellite laser communication; simultaneously, the second communication satellite generates a second physical frame based on a second inter-satellite link overhead and sends it to the first communication satellite through the inter-satellite laser communication link to indicate the satellite trajectory of the second communication satellite, which can improve the stability and adaptability of inter-satellite communication, maintain the continuity of the link in an environment where satellites move rapidly, and solve the technical problem of poor adaptability to the space laser communication environment in related technologies.

Description

Technical Field

[0001] This application relates to the field of laser communication technology, and more specifically, to an inter-satellite laser communication method and system, a computer program product, and a storage medium. Background Technology

[0002] In related technologies, satellite-based bearer networks can directly reuse the Optical Transport Network (OTN) protocol of terrestrial bearer networks for inter-satellite laser communication. However, satellite-based bearer networks and terrestrial bearer networks differ to varying degrees in terms of link conditions, resulting in poor adaptability to the space laser communication environment in satellite-based bearer networks. Summary of the Invention

[0003] This application provides an inter-satellite laser communication method and system, a computer program product, and a storage medium to at least solve the technical problem of poor adaptability to the space laser communication environment in satellite-borne networks in related technologies.

[0004] According to one aspect of the embodiments of this application, an inter-satellite laser communication method is provided, comprising: a first communication satellite generating a first physical frame based on a first inter-satellite link overhead, and transmitting the first physical frame to a second communication satellite via an inter-satellite laser communication link, wherein the first inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite; the second communication satellite adjusting the beam focus of the second communication satellite based on the first inter-satellite link overhead in the first physical frame, generating a second physical frame based on a second inter-satellite link overhead, and transmitting the second physical frame to the first communication satellite via the inter-satellite laser communication link, wherein the second inter-satellite link overhead is used to indicate the satellite trajectory of the second communication satellite.

[0005] According to another aspect of the embodiments of this application, an inter-satellite laser communication system is also provided, comprising: a first communication satellite and a second communication satellite, the first communication satellite and the second communication satellite communicating via an inter-satellite laser communication link; wherein, the first communication satellite is configured to generate a first physical frame based on a first inter-satellite link overhead, and transmit the first physical frame to the second communication satellite via the inter-satellite laser communication link, wherein the first inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite; the second communication satellite is configured to adjust the beam focus of the second communication satellite based on the first inter-satellite link overhead in the first physical frame, generate a second physical frame based on a second inter-satellite link overhead, and transmit the second physical frame to the first communication satellite via the inter-satellite laser communication link, wherein the second inter-satellite link overhead is used to indicate the satellite trajectory of the second communication satellite.

[0006] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, wherein a computer program is stored therein, wherein the computer program is configured to perform the steps in any of the above method embodiments when executed by a processor.

[0007] According to another aspect of the embodiments of this application, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform the steps in any of the method embodiments described above.

[0008] According to another aspect of the embodiments of this application, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to perform the steps of any of the above method embodiments through the computer program.

[0009] Through this application, a first communication satellite generates a first physical frame based on a first inter-satellite link overhead. This first inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite. When a second communication satellite receives the first physical frame containing the first inter-satellite link overhead, it adjusts its own beam focus according to the satellite trajectory information of the first communication satellite to ensure that the laser beam accurately tracks the first communication satellite, effectively overcoming optical path deviation caused by satellite motion and improving the robustness of inter-satellite laser communication. Simultaneously, the second communication satellite generates a second physical frame based on a second inter-satellite link overhead and sends it back to the first communication satellite via the inter-satellite laser communication link to indicate the satellite trajectory of the second satellite. This two-way communication mechanism ensures the robustness of inter-satellite communication. Satellites participating in the communication can monitor each other's positions and motion status in real time, which is beneficial for maintaining high-quality laser links in complex space environments, thereby improving the efficiency and accuracy of data transmission. By sending physical frames to each other, the inter-satellite laser communication link can achieve self-calibration. By monitoring the quality of the optical signal in real time and dynamically adjusting the beam, it ensures optimal optical path coaxiality, thereby optimizing communication performance and reducing the bit error rate. This can significantly improve the stability and reliability of inter-satellite communication, reduce the bit error rate, and maintain the continuity and efficiency of the laser link in environments where satellites are moving rapidly. Therefore, it solves the technical problem of poor adaptability to space laser communication environments in related technologies. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating an application scenario of an inter-satellite laser communication method according to an embodiment of this application;

[0011] Figure 2This is a flowchart illustrating an optional inter-satellite laser communication method according to an embodiment of this application;

[0012] Figure 3 This is a schematic diagram of an optional OTN optical transmission frame format provided according to an embodiment of this application;

[0013] Figure 4 This is a schematic diagram of the structure of an optional optical channel data unit frame according to an embodiment of this application;

[0014] Figure 5 This is a schematic diagram of an optional inter-satellite laser communication link (OTN) interface provided according to an embodiment of this application;

[0015] Figure 6 This is a schematic diagram of another optional optical channel data unit frame provided according to an embodiment of this application;

[0016] Figure 7 This is a structural block diagram of an optional inter-satellite laser communication device according to an embodiment of this application;

[0017] Figure 8 This is a computer system architecture block diagram of an optional electronic device according to an embodiment of this application. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] According to one aspect of the embodiments of this application, an inter-satellite laser communication method is provided. Optionally, in this embodiment, the above-described inter-satellite laser communication method may be applied, but is not limited to, to applications such as... Figure 1 The hardware environment shown includes multiple satellite devices 102. Each satellite device 102 can connect to another satellite device 102 via laser signals, meaning that every two satellite devices 102 can be connected to each other, which can be used to achieve inter-satellite laser information exchange.

[0021] The inter-satellite laser communication method of this application embodiment can be executed by a single satellite device or by two satellite devices jointly. Taking the execution of the inter-satellite laser communication method of this embodiment by two satellite devices as an example, Figure 2 This is a flowchart illustrating an optional inter-satellite laser communication method according to an embodiment of this application, as shown below. Figure 2 As shown, the process of this method may include steps S202 to S204.

[0022] In step S202, the first communication satellite generates a first physical frame based on the first inter-satellite link overhead and sends the first physical frame to the second communication satellite through the inter-satellite laser communication link. The first inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite.

[0023] In step S204, the second communication satellite adjusts its beam focus based on the first inter-satellite link overhead in the first physical frame, generates a second physical frame based on the second inter-satellite link overhead, and sends the second physical frame to the first communication satellite through the inter-satellite laser communication link. The second inter-satellite link overhead is used to indicate the satellite trajectory of the second communication satellite.

[0024] The inter-satellite laser communication method in this embodiment can be applied to the field of laser communication, specifically to scenarios where two satellites communicate with each other via an inter-satellite laser communication link.

[0025] Optical Transport Network (OTN) based on G.709 (an optical transport network standard developed by the International Telecommunication Union and one of the communication protocols for terrestrial optical communication) is a mature system that can be applied to optical communication engineering. The features of the aforementioned OTN optical transport system include high-efficiency carrying capacity, high-performance forward error correction (FEC) capability, rich overhead and maintenance management mechanisms, and flexible data encapsulation and mapping mechanisms. It can support the long-term continuous evolution of large-scale networks, ensure forward compatibility, and avoid network remediation and investment waste.

[0026] In related technologies, satellite-based transport networks can directly reuse terrestrial optical transport network protocols for inter-satellite laser communication. While satellite and terrestrial transport networks share many similarities, they also differ to varying degrees in terms of link conditions. Satellite networks have higher requirements for stability, reliability, transport efficiency, and maintainability. However, directly reusing terrestrial OTN protocols cannot meet the higher requirements of space-based transport networks in terms of stability, reliability, transport efficiency, and maintainability. Therefore, the aforementioned inter-satellite laser communication methods suffer from poor adaptability to the space laser communication environment.

[0027] To at least partially solve the aforementioned technical problems, in this embodiment, the first communication satellite generates a first physical frame based on the first inter-satellite link overhead. The first inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite. When the second communication satellite receives the first physical frame with the first inter-satellite link overhead, it can adjust its own beam focus according to the satellite trajectory information of the first communication satellite to ensure that the laser beam accurately tracks the first communication satellite, effectively overcoming the optical path deviation caused by satellite motion and improving the robustness of inter-satellite laser communication. The second communication satellite generates a second physical frame based on the second inter-satellite link overhead and sends it back to the first communication satellite through the inter-satellite laser communication link to indicate the second... The satellite trajectory of the communication satellite; this two-way communication mechanism ensures that all satellites participating in the communication can keep track of each other's positions and motion status in real time, which is conducive to maintaining a high-quality laser link in a complex space environment, thereby improving the efficiency and accuracy of data transmission. By sending physical frames to each other, the inter-satellite laser communication link can achieve self-calibration. By monitoring the quality of the optical signal in real time and dynamically adjusting the beam, it ensures the best coaxiality of the optical path, thereby optimizing communication performance and reducing the bit error rate. It can significantly improve the stability and reliability of inter-satellite communication, reduce the bit error rate, and maintain the continuity and efficiency of the laser link in an environment where satellites are moving rapidly.

[0028] In this embodiment, the first communication satellite and the second communication satellite are two satellites that conduct communication. The first communication satellite and the second communication satellite can take turns acting as the transmitter and receiver of communication. When one of the first communication satellite and the second communication satellite is the transmitter, the other of the first communication satellite and the second communication satellite is the receiver. Optionally, the first communication satellite and the second communication satellite can be two satellites located in the same orbit, or they can be two satellites located in different orbits.

[0029] For the first communication satellite, it can generate a first physical frame based on the first inter-satellite link overhead and send the first physical frame to the second communication satellite via the inter-satellite laser communication link. Here, the first inter-satellite link overhead can be used to indicate the satellite trajectory of the first communication satellite. The first inter-satellite link overhead can include any information that can indicate the motion state of the first communication satellite in space, including but not limited to at least one of the first communication satellite's position coordinates, velocity vector, and time information. The first physical frame refers to the physical frame generated by the first communication satellite based on the first inter-satellite link overhead, used to transmit the satellite information of the first communication satellite. For example, the first physical frame includes the first inter-satellite link overhead, service data, and other overhead information. The frame format of the first physical frame can be the OTN frame format, or a new frame format designed for the inter-satellite link overhead transmission function, or other frame formats. This embodiment does not limit this. The inter-satellite laser communication link refers to the communication link between two communication satellites used to transmit laser signals. The first physical frame can be sent to the second communication satellite through the inter-satellite laser communication link between the first and second communication satellites. Optionally, the inter-satellite laser communication link can be adapted based on the OTN interface, inheriting the basic functions of OTN technology.

[0030] Optionally, the first communication satellite can collect or calculate its own real-time orbit information, including its current position coordinates (X, Y, Z), current velocity vector (Vx, Vy, Vz), and current timestamp. In the OTN frame structure, the first communication satellite fills the real-time orbit information into the designated first inter-satellite link overhead. Based on the above OTN frame structure, the first inter-satellite link overhead with the filled orbit information is inserted into the appropriate position of the frame structure of the first physical frame, thus forming the first physical frame containing the orbit information of the first communication satellite.

[0031] In some optional embodiments, transmitting the first physical frame to the second communication satellite via the inter-satellite laser communication link includes: converting the first physical frame into an optical signal, and transmitting the converted optical signal to the second communication satellite via the optical transport network interface of the inter-satellite laser communication link. The optical transport network interface is the interface of the inter-satellite laser communication link used to transmit or receive optical signals.

[0032] For the second communication satellite, its beam focusing can be adjusted based on the first inter-satellite link overhead in the first physical frame. Beam focusing refers to the process of accurately aligning a beam emitted by a light source with a predetermined target. Optionally, beam focusing may include beam direction adjustment and beam focusing and beam expansion; here, beam focusing of the second communication satellite refers to the process of the second communication satellite aligning a beam emitted by a light source with the first communication satellite.

[0033] Because satellites are constantly moving in their orbits and moving at relatively high speeds relative to Earth and other satellites, they may encounter minor disturbances in the space environment (such as solar radiation pressure, irregular changes in Earth's gravitational field, etc.). As a result, the relative positions between satellites are constantly changing. Therefore, in order to maintain a stable inter-satellite laser communication link, satellites can periodically or even in real time adjust the orientation of their laser transmitters and receivers to maintain the accuracy of laser beam focusing.

[0034] Optionally, the laser receiving terminal of the second communication satellite can capture the laser signal transmitted by the first communication satellite and convert it into an electrical signal. The electrical signal can be sent to the signal processing system of the second communication satellite, which can parse the structure of the first physical frame and extract the orbital information of the first communication satellite from the first inter-satellite link overhead. The orbit calculation module of the second communication satellite can calculate the relative position and motion relationship between the two satellites based on the satellite trajectory information (including position coordinates, velocity vector, and time information) carried in the first inter-satellite link overhead and its own orbital information. Based on the calculated relative position and motion relationship, the beam adjustment module of the second communication satellite can calculate the beam focusing adjustment parameters (which may include, but are not limited to, changes in laser emission angle, frequency, or power). The beam adjustment module can send the calculated parameters to the optical transmitting terminal of the second communication satellite (including adjustment commands from the precision aiming scope or the pre-aiming scope). The optical transmitting terminal of the second communication satellite can adjust the light emission angle according to the received adjustment commands to ensure that the laser beam is accurately aligned with the first communication satellite, thereby maintaining a stable communication link.

[0035] The second inter-satellite link overhead is used to indicate the satellite trajectory of the second communication satellite. The second inter-satellite link overhead may include any information that can indicate the motion state of the second communication satellite in space, including but not limited to at least one of the position coordinates, velocity vector, and time information of the second communication satellite.

[0036] The second physical frame refers to the physical frame generated by the second communication satellite based on the second inter-satellite link overhead, used to transmit satellite information of the second communication satellite. For example, the second physical frame may include the second inter-satellite link overhead, service data, and other overhead information. The frame format of the first physical frame can be the OTN frame format, a new frame format designed for the inter-satellite link overhead transmission function, or other frame formats; this embodiment does not limit this. The second inter-satellite link overhead can be located within the OTN frame format.

[0037] Optionally, after the second communication satellite transmits the second physical frame to the first communication satellite via the inter-satellite laser communication link, the first communication satellite adjusts its beam focus based on the second inter-satellite link in the second physical frame.

[0038] The method by which the second communication satellite generates the second physical frame based on the second inter-satellite link overhead can refer to the method by which the first communication satellite generates the first physical frame based on the first inter-satellite link overhead, and will not be repeated here.

[0039] Through the embodiments provided in this application, a first communication satellite generates a first physical frame based on a first inter-satellite link overhead, wherein the inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite. When the second communication satellite receives the first physical frame with the first inter-satellite link overhead, it can adjust its own beam focus according to the satellite trajectory information of the first communication satellite, ensuring that the laser beam accurately tracks the first communication satellite, effectively overcoming the optical path deviation caused by satellite motion and improving the robustness of inter-satellite laser communication. Simultaneously, the second communication satellite generates a second physical frame based on a second inter-satellite link overhead and sends it back to the first communication satellite via the inter-satellite laser communication link to indicate the satellite trajectory of the second communication satellite. This two-way communication mechanism ensures… This technology ensures that all participating satellites in inter-satellite communication can monitor each other's positions and motion status in real time. This is beneficial for maintaining high-quality laser links in complex space environments, thereby improving the efficiency and accuracy of data transmission. By sending physical frames between two satellites, the inter-satellite laser communication link can achieve self-calibration. By monitoring the quality of the optical signal in real time and dynamically adjusting the beam, it ensures optimal optical path coaxiality, thereby optimizing communication performance and reducing the bit error rate. This significantly improves the stability and reliability of inter-satellite communication, reduces the bit error rate, and maintains the continuity and efficiency of the laser link even in environments with rapid satellite movement. Therefore, it solves the technical problem of poor adaptability to space laser communication environments in related technologies.

[0040] In an exemplary embodiment, a first communication satellite generates a first physical frame based on a first inter-satellite link overhead, comprising: the first communication satellite generating a first physical frame based on specified service data and the first inter-satellite link overhead, wherein the specified service data is service data to be transmitted by the first communication satellite to a second communication satellite, the specified service data is mapped to the payload area of ​​the first physical frame, and the first inter-satellite link overhead is mapped to an inter-satellite link overhead channel, the inter-satellite link overhead channel being the specified overhead area of ​​the first physical frame.

[0041] In this embodiment, the designated service data refers to the service data to be transmitted from the first communication satellite to the second communication satellite. Optionally, the designated service data can originate from ground equipment or from other satellites. For example, the designated service data can be customer service data (which may include voice, video, data packets, remote sensing images, etc.) or other service data; no specific limitations are imposed here.

[0042] The payload area of ​​the first physical frame refers to the area used to carry specified service data. Optionally, the first communication satellite may map the specified service data to the payload area of ​​the first physical frame.

[0043] Optionally, the specified service data can be mapped to the payload area of ​​the first physical frame in one of the following ways, but not limited to: Method 1: For specified service data with a fixed format and speed, the specified service data is directly mapped to the payload area of ​​the first physical frame; Method 2: For specified service data with a non-fixed format, a general mapping method is used, and the specified service data is adjusted to the payload area of ​​the first physical frame through an adaptation layer; Method 3: The specified service data is grouped, and each group is regarded as an independent unit and mapped to the payload area of ​​the first physical frame.

[0044] For example, the first communication satellite can adapt the received specified service data so that the specified service data format meets the requirements of the inter-satellite laser communication link; use a mapping algorithm to fill the adapted specified service data into the payload area of ​​the first physical frame in a specified order to achieve the initial encapsulation of the specified service data; the first communication satellite checks the payload area filling status of the first physical frame to ensure that the specified service data is complete and meets the capacity limit of the first physical frame.

[0045] In this embodiment, the first communication satellite can map the first inter-satellite link overhead to the inter-satellite link overhead channel of the first physical frame. The inter-satellite link overhead channel refers to a designated overhead area of ​​the first physical frame used to transmit inter-satellite link overhead information. Optionally, the inter-satellite link overhead channel can be a channel for real-time feedback of inter-satellite communication status and beam alignment adjustment. The inter-satellite link overhead channel can include a fast channel and a slow channel.

[0046] Optionally, the first communication satellite can acquire designated service data and map it to the payload area of ​​the first physical frame to ensure proper data encapsulation and transmission preparation. The first communication satellite can update and collect its own satellite trajectory information (which may include position coordinates, velocity vectors, timestamps, etc.) in real time and map the collected trajectory information (i.e., the first inter-satellite link overhead) to the inter-satellite link overhead channel of the first physical frame. According to the OTN standard, the first communication satellite can convert the constructed first physical frame into an optical signal and transmit it to the second communication satellite via an inter-satellite laser communication link.

[0047] In this embodiment, based on specified service data, the first inter-satellite link overhead is mapped to the inter-satellite link overhead channel of the first physical frame, which can ensure efficient and stable transmission of service data and satellite trajectory information. It can also realize independent processing of service data and overhead information, so that the transmission of real-time satellite trajectory information will not interfere with the transmission of service data.

[0048] In an exemplary embodiment, the electrical layer of the inter-satellite laser communication link includes multiple sublayers such as optical channel payload units, optical channel data units, optical channel transmission units, and a physical layer. The payload area of ​​the first physical frame corresponds to the optical channel payload unit, and the overhead area of ​​the first physical frame includes the overhead area of ​​each of the multiple sublayers. The designated overhead area belongs to the overhead area of ​​the optical channel data unit.

[0049] In this embodiment, the electrical layer of the inter-satellite laser communication link refers to the layer that processes and encapsulates the raw data before optical signal transmission, converting the raw data into a format suitable for transmission via optical signals. The electrical layer of the inter-satellite laser communication link may include multiple sub-layers: Optical Channel Payload Unit (OPU), Optical Channel Data Unit (ODU), Optical Channel Transport Unit (OTU), and Physical Layer (PHY). The inter-satellite laser communication link may also include an optical layer; that is, the inter-satellite laser communication link may include a two-layer structure of electrical and optical layers.

[0050] Optionally, the overhead region of the first physical frame may include regions containing overhead information from multiple sublayers of the electrical layer of the inter-satellite laser communication link. Optionally, the overhead region of the first physical frame may include the overhead region of the optical channel payload unit, the overhead region of the optical channel data unit, the overhead region of the optical channel transmission unit, and the overhead region of the physical layer.

[0051] Here, the optical channel payload unit (OPU) is a unit used to encapsulate and map the first physical frame of the OTN. The payload area of ​​the first physical frame corresponds to the OPU. For example, the OPU may include the payload area of ​​the first physical frame and the Optical Channel Payload Unit Overhead (OPU OH) located in the overhead area of ​​the OPU. The payload area of ​​the OPU is the area in the OTN used to carry specified service data.

[0052] Optical channel data units (ODUs) can provide monitoring and maintenance information in inter-satellite laser communication. Optionally, an ODU can be a sublayer located above an optical channel payload unit. An ODU includes the optical channel payload unit and the optical channel data unit overhead (ODU OH) located in the overhead region of the ODU. The specified overhead region is located within the overhead region of the ODU; for example, the inter-satellite link overhead channel belongs to the overhead region of the ODU.

[0053] An optical channel transport unit (OCU) can be a unit used to transmit and protect data from optical channel payload units and optical channel data units. Optionally, the OCU is the outermost layer of the electrical layer, and it can include optical channel data units and optical channel transport unit overhead (OTU OH) located in the overhead region of the OCU. For example, the OCU overhead can include overhead information such as signal positioning, performance monitoring, and FEC configuration information.

[0054] The physical layer is a sublayer used for direct interaction with inter-satellite laser communication links. Optionally, the physical layer may include error detection and correction capabilities for laser signals. The physical layer corresponds to the transmission of the first physical frame on the physical medium; that is, the PHY layer corresponds to the inter-satellite physical optical signal. The physical layer may include optical channel transmission units and physical layer overhead (PHY OH) located in the overhead region of the physical layer.

[0055] In some embodiments, the first communication satellite may add optical channel payload unit overhead to the overhead area of ​​the optical channel payload unit to form an optical channel payload unit frame. Optical channel payload unit overhead refers to the overhead used to carry control and monitoring information in the structure of the OPU frame, which may include, but is not limited to, all or part of signal identifier, payload unit type, payload length, and source identifier. The optical channel payload unit frame is a frame structure of the electrical layer formed by combining specified service data and OPU overhead.

[0056] Optionally, the first communication satellite can verify the optical channel payload unit frame to determine whether the information of the optical channel payload unit overhead is correct, in order to prevent the phenomenon of frame misunderstanding during transmission, and to check whether the frame structure of the optical channel payload unit frame meets the requirements of the sub-layer of the optical channel payload unit of the inter-satellite laser communication link.

[0057] Subsequently, the first communication satellite can add optical channel data unit overhead based on the optical channel payload unit frame to form an optical channel data unit frame. The optical channel data unit overhead can be located in the frame structure of the ODU to provide higher-level monitoring, management, and maintenance functions. Optionally, the ODU OH can contain various subfields, such as all or some of the following fields: PathMonitoring (PM), Tandem Connection Monitoring (TCM), General Communication Channel (GCC), Automatic Protection Switching / Pre-determined Connection Channel (APS / PCC), and Experimental (EXP).

[0058] After forming an optical channel data unit frame, the first communication satellite can add optical channel transmission unit overhead and physical layer overhead corresponding to the electrical layer of the inter-satellite laser communication link to the optical channel data unit frame, thus forming a signal to be transmitted. This signal is the one that the first communication satellite will send to the second communication satellite. After forming the signal to be transmitted, the first communication satellite can convert it into an optical signal and transmit it to the designated satellite through the optical transport network interface of the inter-satellite laser communication link.

[0059] For example, Figure 3 This is a schematic diagram of an optional OTN optical transmission frame format provided according to an embodiment of this application, such as... Figure 3 The diagram illustrates the positions of the positioning pointer, OPU overhead, OTU overhead, ODU overhead, and payload area within the OTN.

[0060] Through this embodiment, by integrating a designated overhead area at the ODU layer, the inter-satellite communication system can monitor and transmit critical link status information in real time. This helps to quickly restore communication in unstable situations such as link interruptions, enhances the stability and reliability of the link, and ensures the high efficiency of inter-satellite information transmission.

[0061] In one exemplary embodiment, the overhead area is specified as at least one of the following in the overhead area of ​​the optical channel data unit: specifying a reserved field, specifying an experimental field. The specified reserved (RES) field is a reserved area in the optical channel data unit, and the specified experimental (EXP) field is an experimental area in the optical channel data unit.

[0062] Optionally, the RES field can be an undefined space reserved for future standards or feature expansions. In applications, the first communication satellite acting as the transmitter typically sets the RES field to a fixed value (e.g., all zeros), while the second communication satellite acting as the receiver ignores its content, ensuring compatibility between different versions of equipment. The EXP field can be used by users (e.g., equipment manufacturers or operators) to test new features, such as new Operation, Administration, and Maintenance (OAM) mechanisms or flow control, allowing users to customize their usage.

[0063] Optionally, the first communication satellite can map the first inter-satellite link overhead to the inter-satellite link overhead channel of the optical channel data unit to form an optical channel data unit frame in the following ways: Case 1: Based on the optical channel payload unit frame, the inter-satellite link overhead can be mapped to a specified reserved field in the optical channel data unit frame structure to form an optical channel data unit frame; Case 2: Based on the optical channel payload unit frame, the inter-satellite link overhead can be mapped to a specified experimental field in the optical channel data unit frame structure to form an optical channel data unit frame; Case 3: Based on the optical channel payload unit frame, the inter-satellite link overhead can be mapped to the specified reserved field and the specified experimental field of the optical channel data unit respectively to form an optical channel data unit frame.

[0064] In this embodiment, the overhead area is designated as at least one of the designated reserved fields and designated experimental fields in the overhead area of ​​the optical channel data unit, which enables inter-satellite laser communication to introduce inter-satellite-specific monitoring and control information while maintaining compatibility with ground-based OTN technology, thereby enhancing the adaptability of space communication to the laser communication environment.

[0065] In one exemplary embodiment, the reserved field is located in the second row and the first to second columns of the frame structure of the first physical frame, and the experimental field is located in the second row and the fourth column of the frame structure of the first physical frame.

[0066] In this embodiment, the reserved field is located in the second row and the first to second columns of the frame structure of the optical channel data unit of the first physical frame, and the experimental field is located in the second row and the fourth column of the frame structure of the optical channel data unit of the first physical frame.

[0067] For example, Figure 4 This is a schematic diagram of the structure of an optional optical channel data unit frame according to an embodiment of this application, such as... Figure 4As shown, in the terrestrial OTN protocol, the ISL-ODU overhead includes Channel Monitoring (PM), Serial Connection Monitoring (TCM), General Communication Channel (GCC1 / GCC2), Protection Switching (APS / PCC), and Experimental Channel (EXP). Specifically, columns 1-2 of the second row represent reserved fields in the frame structure of the optical channel data unit in the terrestrial OTN protocol, while column 4 of the second row represents experimental fields.

[0068] By distinguishing the positions of designated reserved fields and designated experimental fields in the frame structure of the first physical frame, this not only ensures the timely transmission of real-time inter-satellite information, but also effectively utilizes fields in the frame structure of the first physical frame that were not originally fully used, thus optimizing the inter-satellite communication link and reducing unnecessary redundant transmission.

[0069] In one exemplary embodiment, the overhead region of the first physical frame further includes a forward error correction overhead region, wherein the forward error correction overhead region is used to write forward error correction overhead. Here, the forward error correction overhead region can refer to the area where forward error correction overhead is written, which is the overhead used to detect and correct errors during laser signal transmission.

[0070] Optionally, the forward error correction overhead region can be located in the physical layer. Correspondingly, the physical layer may include optical channel transmission units, the overhead region corresponding to the physical layer, and the forward error correction overhead region.

[0071] Optionally, optical channel transmission unit overhead can be added to the optical channel data unit frame to form an optical channel transmission unit frame; physical layer overhead and forward error correction overhead can be added to the optical channel transmission unit frame to form a physical layer frame.

[0072] For example, Figure 5 This is a schematic diagram of an optional inter-satellite laser communication link (OTN) interface provided according to an embodiment of this application, such as... Figure 5As shown, firstly, specified service data (such as customer service data) is mapped to the payload area of ​​the OPU, and the OPU overhead is mapped to the overhead area of ​​the OPU to form an Inter-Satellite Link-Optical Channel Payload Unit (ISL-OPU) frame; then, based on the ISL-OPU frame, ODU overhead is added to provide functions such as PM to form an Inter-Satellite Link-Optical Channel Data Unit (ISL-ODU) frame; then, based on the ISL-ODU frame, OTU overhead is added to provide segment monitoring (Signal Monitoring, SM) monitoring function to form an Inter-Satellite Link-ISL-Optical Channel Transport Unit (OTU) frame; finally, an FEC area is added to the ISL-OTU frame to form an Inter-Satellite Link-Physical Layer (ISL-PHY) frame. Finally, an inter-satellite laser communication link (ISL-OTN) interface signal is formed, and the ISL-OTN interface signal is converted into an optical signal for transmission.

[0073] For example, the ISL-OTN interface overhead includes: FEC overhead, ISL-OTU overhead (including frame positioning overhead), ISL-ODU overhead, and ISL-OPU overhead. The optical layer overhead in the terrestrial OTN transmission protocol can be used for Wavelength Division Multiplexing (WDM), that is, overhead at different wavelengths. This embodiment mainly involves the ISL-OTN overhead in a single wavelength (this embodiment can also be applied to WDM systems with optical layer overhead, i.e., adding corresponding inter-satellite overhead content in different wavelengths). The definitions and functions of the overhead components OPUk, ODUk, and OTUk in the ISL-OTN interface overhead are the same as in the terrestrial OTN protocol standard. The 'k' above represents the level; different levels have different rates (bit values). The larger 'k' is, the shorter the frame period and the higher the frame rate.

[0074] The frame alignment section (FAS) overhead is used for signal frame alignment and consists of three Overhead Alignment (OA) bytes 1 and three OA2 bytes. The Multi-Frame Alignment Signal (MFAS) is used for multi-frame alignment; an MFAS multi-frame can include up to 256 base frames, and this field is used for transmitting some overhead information. The OTUk overhead is mainly used for viewing and managing OTUk link layer information, including SM and GCC0. The ODUk overhead is used for ODU layer signal monitoring and pre-management, located in columns 14 of rows 2-4 of the frame structure, including PM, GCC1 / GCC2, APS / PCC, EXP, Fixed Transport Frame Overhead (FTFL), and TCM1-TCM3. The OPUk overhead is used for payload supervision and control, including Payload Structure Indication (PSI) and Justification. Control (JC), Positive Justification Opportunity (PJO), Negative Justification Opportunity (NJO), etc.

[0075] In this embodiment, the introduction of the forward error correction overhead region effectively improves the signal integrity of the inter-satellite laser communication link. Even if a certain degree of interference or distortion is encountered during transmission, errors can be automatically corrected through the FEC mechanism, reducing the number of data packet drops and retransmissions.

[0076] In an exemplary embodiment, the inter-satellite link overhead channel includes an inter-satellite slow channel, which is an experimental field in the overhead area of ​​the first physical frame. The inter-satellite slow channel is used to transmit a first type of inter-satellite information in the first inter-satellite link overhead. The first type of inter-satellite information includes satellite orbit information, which is used to indicate the satellite trajectory of the first communication satellite.

[0077] In this embodiment, the inter-satellite slow channel is a channel in the inter-satellite laser communication link used to transmit periodic, non-real-time information. For example, the inter-satellite slow channel can be mapped to the experimental field in the overhead area of ​​the first physical frame. For instance, the EXP field can be located in the second row and fourth column of the frame structure of the optical channel data unit. The EXP field can be defined as the inter-satellite slow channel. Alternatively, a portion of the experimental field can be used as the inter-satellite slow channel, or the entire experimental field can be used as the inter-satellite slow channel.

[0078] Optionally, if the first inter-satellite link overhead includes a first type of inter-satellite information, the first communication device can map the first type of inter-satellite information in the inter-satellite link overhead to the inter-satellite slow channel based on the optical channel payload unit frame. That is, it can map the first type of inter-satellite information in the inter-satellite link overhead to a specified experimental field to form an optical channel data unit frame. The first type of inter-satellite information can be inter-satellite information transmitted at a low frequency.

[0079] Optionally, an inter-satellite slow channel is introduced into the frame structure of the optical channel data unit frame in the first physical frame. That is, when the first inter-satellite link overhead includes the second type of inter-satellite information, the second type of inter-satellite information in the first inter-satellite link overhead is mapped to the inter-satellite slow channel based on the optical channel payload unit frame to form the optical channel data unit frame.

[0080] Satellite orbit information is information that indicates the current and future spatial position and motion status of a satellite. For example, satellite orbit information may include position coordinates, velocity vectors, and timestamps.

[0081] Optionally, satellite orbit information can be used to predict the current satellite position (such as the first communication satellite) by orbit extrapolation in the event of an interruption of the inter-satellite laser communication link. Based on the predicted satellite position and ephemeris information, the inter-satellite laser communication link can be restored. This allows the communication peer system (such as the second communication satellite) to keep track of the other party's latest satellite orbit information at all times under the condition of inter-satellite link interconnection. This ensures that in scenarios such as link interruption, the target satellite (such as the second communication satellite) can be quickly pointed to its position through short-term orbit extrapolation to achieve rapid link restoration.

[0082] This embodiment utilizes the inter-satellite slow channel to transmit satellite orbit information, which can significantly improve the accuracy and reliability of inter-satellite laser communication. The periodic orbit information updates obtained through the inter-satellite slow channel can predict and adjust beam alignment, reduce communication interruptions caused by changes in satellite position, optimize communication link management, and ensure the long-term stable and efficient operation of inter-satellite communication.

[0083] In one exemplary embodiment, the first type of inter-satellite information further includes at least one of the following: system version information for confirming the version information used by the first communication satellite in the inter-satellite laser communication system; first link quality information for indicating the performance indicators of the inter-satellite laser communication link; and auxiliary tracking information for self-calibrating the optical path coaxiality between the second communication satellite and the first communication satellite, and indicating the avoidance angle for the second communication satellite to enter solar outage, so as to predict the time of solar outage of the second communication satellite.

[0084] In this embodiment, system version information refers to the version information used in the inter-satellite laser communication system. The system version information can be used to confirm the version information used by the current satellite (such as the first communication satellite) in the inter-satellite laser communication system. For example, the system version information may include information such as protocol version, software version, hardware version, and optomechanical (optical mechanical equipment) version. Optionally, the system version information is mainly used to confirm the relevant protocol, optomechanical system, and communication spacecraft number. The system version information includes protocol version number, optomechanical system version number, and spacecraft number.

[0085] The first link quality information is low-frequency performance data of the inter-satellite laser communication link. This information can be used to transmit performance indicators of the inter-satellite laser communication link. Auxiliary tracking and aiming information includes all auxiliary information for beam tracking and aiming in inter-satellite laser communication. This information can be used to self-calibrate the optical path coaxiality between the second and first communication satellites, and to indicate the avoidance angle for the second communication satellite entering solar outage, thus predicting the time of solar outage for the second communication satellite. For example, the first communication satellite receives the solar outage avoidance angle of the second communication satellite (i.e., the communication peer) in real time, predicts the time of solar outage for the second satellite, and notifies the first communication satellite (e.g., via onboard routing) to provide advance warning of inter-satellite solar outage avoidance.

[0086] Optionally, the first link quality information and auxiliary tracking information (i.e., link quality feedback and auxiliary tracking information) include all or some of the parameters such as local optical amplifier output, input optical power, detector grayscale, bit error rate, and solar avoidance angle. The optical amplifier output of the current satellite equipment (i.e., the local communication end, such as the first communication satellite) can help the designated satellite (i.e., the peer end, such as the second communication satellite) determine the quality of the incoming optical signal; the input optical power and detector grayscale can help the designated satellite determine the quality of the optical signal received by the current satellite equipment; the communication bit error rate can inform the designated satellite of the current communication performance of the current satellite equipment; and the solar avoidance angle can inform the designated satellite when the current satellite equipment enters the solar interference avoidance mode.

[0087] For example, the current satellite equipment (i.e., the transmitting side at one end of the communication, such as the first communication satellite) and the designated satellite (i.e., the receiving side at the other end of the communication, such as the second communication satellite) can adjust the angle of the precision aiming scope or the pre-aiming scope in the optical path in real time (e.g., using nutation technology to find the strongest received signal light in real time) and judge the quality of the received optical signal to find the maximum received optical signal quality value, so as to realize real-time self-calibration of the optical path coaxiality using the inter-satellite link. Among them, the auxiliary tracking information also includes the local ranging value, which can be used to instruct the designated satellite to perform ranging and, combined with information such as the time of the current satellite sending the ranging frame, realize on-orbit calculation of inter-satellite laser ranging.

[0088] Optionally, the first type of inter-satellite information may also include configuration information to confirm that 100G optical modules supporting multiple FEC modes are configured with the same FEC to achieve dual-end interoperability, and may include configuration information such as FEC mode.

[0089] After obtaining the first type of inter-satellite information in the inter-satellite link overhead, the first type of inter-satellite information in the inter-satellite link overhead can be mapped to the inter-satellite slow channel. Optionally, at least one of the system version information, satellite orbit information, first link quality information, and auxiliary tracking information can be mapped to the inter-satellite slow channel.

[0090] For example, a schematic table of the first type of inter-satellite information (i.e., the overhead of inter-satellite information transmission) can be shown in Table 1.

[0091] Table 1

[0092]

[0093] Optionally, the inter-satellite information (i.e., inter-satellite overhead) in this embodiment enables the two communication ends (i.e., the first communication satellite and the second communication satellite) to confirm each other's relevant system version information, configuration information, satellite orbit information, second link quality information, and auxiliary tracking information (link quality and auxiliary tracking information). This allows the designated satellite system (e.g., the second communication satellite) to keep track of the latest satellite orbit information of the current satellite (e.g., the first communication satellite) under inter-satellite link interconnection conditions. This ensures that in scenarios such as link interruption, the designated satellite can quickly point to the position of the current satellite through short-time orbit extrapolation to achieve rapid relink reconnection. At the same time, the current satellite (e.g., the first communication satellite on the transmitting side) and the designated satellite (e.g., the second communication satellite on the receiving side) can adjust the angle of the precision aiming scope or the pre-aiming scope in the rear optical path in real time and judge the quality of the received optical signal to find the maximum received optical signal quality value, thereby realizing real-time self-calibration of the optical path coaxiality using the inter-satellite link.

[0094] Through this embodiment, by exchanging system version information, the first and second communication satellites can ensure that the versions of the inter-satellite laser communication system they use are consistent, avoiding communication obstacles caused by version differences. The periodic transmission of the first link quality information enables the second communication satellite to continuously monitor the performance of the inter-satellite link, promptly detect and handle possible signal quality problems, ensure the continuity and high quality of communication, and utilize the auxiliary tracking information. This not only enables self-calibration of optical path coaxiality to ensure precise laser beam docking, but also allows the prediction of solar interference time based on the solar avoidance angle, enabling advance planning of communication strategies to avoid the impact of solar interference.

[0095] In an exemplary embodiment, the inter-satellite link overhead channel further includes an inter-satellite fast channel, which is a reserved field in the overhead area of ​​the first physical frame. The inter-satellite fast channel is used to transmit second type of inter-satellite information in the first inter-satellite link overhead, and the transmission frequency of the first type of inter-satellite information is lower than the transmission frequency of the second type of inter-satellite information.

[0096] In this embodiment, the Inter-Satellite Link-Fast (ISL-FOH) is a channel used to transmit the second type of inter-satellite information in the first inter-satellite link overhead. The second type of inter-satellite information refers to information transmitted at a high frequency. Specifically, the transmission frequency of the first type of inter-satellite information is lower than the transmission frequency of the second type of inter-satellite information.

[0097] In some embodiments, the first inter-satellite link overhead is mapped to the overhead region of the optical channel data unit in the first physical frame. The first inter-satellite link overhead may include inter-satellite fast channel overhead and inter-satellite slow channel overhead. The second inter-satellite link overhead may also include inter-satellite fast channel overhead and inter-satellite slow channel overhead.

[0098] Optionally, the specified RES field mentioned above can be defined as an inter-satellite fast track. For example, a portion of the specified reserved field can be used as an inter-satellite fast track, or all of the experimental field can be used as an inter-satellite fast track.

[0099] Optionally, specific bytes are defined in the inter-satellite fast channel to carry the second type of inter-satellite information. By updating these bytes in real time, high-frequency transmission of the second type of inter-satellite information can be achieved.

[0100] In an optional embodiment, when the first inter-satellite link overhead includes a first type of inter-satellite information, the second type of inter-satellite information in the first inter-satellite link overhead is mapped to the inter-satellite fast channel based on the optical channel payload unit frame to form an optical channel data unit frame; when the first inter-satellite link overhead includes a first type of inter-satellite information, the first type of inter-satellite information in the first inter-satellite link overhead can be mapped to the inter-satellite fast channel based on the optical channel payload unit frame, that is, the first type of inter-satellite information in the inter-satellite link overhead is mapped to a specified RES field to form an optical channel data unit frame.

[0101] For example, Figure 6 This is a schematic diagram of another optional optical channel data unit frame provided according to an embodiment of this application, such as... Figure 4 and Figure 6As shown, this embodiment improves the ISL-ODU overhead by reserving some RES overhead and replacing some EXP overhead with overhead for transmitting inter-satellite laser communication payload communication status overhead. Specifically, dedicated inter-satellite link overhead (ISL-FOH / ISL-SOH) is set in the RES and EXP frames. This dedicated overhead includes fast channel overhead and slow channel overhead, used for inter-satellite laser information exchange to achieve functions such as assisted tracking and communication status monitoring. In this embodiment, the fast channel overhead and slow channel overhead can be designed into the RES and EXP overhead in the OTN frame format according to requirements. For example, the fast channel is designed in the second row, first and second columns, focusing on transmitting the current value of the received optical power. The overhead channels for inter-satellite information transmission are divided into two categories: one is the fast channel, i.e., ISL_FOH, which can carry information with high transmission frequency requirements, such as real-time optical power; the other is the slow channel, i.e., ISL_SOH, which can carry information with low transmission frequency requirements.

[0102] In this embodiment, the use of inter-satellite fast channels ensures real-time feedback of link status information. The first and second types of inter-satellite information are transmitted through channels of different frequencies, meeting different information update needs and ensuring efficient management and utilization of inter-satellite communication links. The differentiated use of inter-satellite fast channels and inter-satellite slow channels optimizes the allocation of communication resources, improves the overall transmission efficiency and reliability of the system, and also ensures the updating of inter-satellite information.

[0103] In one exemplary embodiment, the second type of inter-satellite information includes at least one of the following: optical power information, second link quality information, beam tracking instructions, real-time alarm information, and system status updates.

[0104] In this embodiment, optical power information is used to monitor the quality of inter-satellite communication links in real time and to adjust and optimize the optical path. For example, optical power information can be the current value of the received optical power.

[0105] The second link quality information consists of performance parameters for high-frequency inter-satellite communication links, reflecting the real-time transmission quality of the link. Beam tracking commands are instructions to track the satellite beam, guiding precise optical path adjustments to ensure stable beam alignment with the designated satellite and reduce communication interruptions. Real-time alarm information is used for rapid response and handling of unexpected situations in the inter-satellite communication link; for example, real-time alarm information may include link failures, performance anomalies, or other warnings requiring immediate attention. System status updates can be used to change the operating mode of satellite equipment; for example, system status updates may include, but are not limited to, satellite equipment entering or exiting solar interference avoidance mode, energy management status, and changes to satellite equipment configuration.

[0106] Optionally, after obtaining the second type of inter-satellite information in the first inter-satellite link overhead, the second type of inter-satellite information in the first inter-satellite link overhead is mapped to the inter-satellite fast channel. For example, at least one of optical power information, first link quality information, beam tracking command, real-time alarm information, and system status update is mapped to the inter-satellite fast channel.

[0107] In an optional embodiment, when the second type of inter-satellite information is optical power information, the first communication satellite can continuously monitor the optical path status. Once it detects that the optical power change exceeds a preset threshold, it immediately updates the optical power information in the inter-satellite fast channel to notify the second communication satellite to make corresponding adjustments.

[0108] In this embodiment, the high-frequency transmission of optical power information and second link quality information enables the inter-satellite communication system to monitor link status in real time, adjust communication parameters instantly, and maintain optimal link performance. The rapid transmission of real-time alarm information ensures that both communicating parties can respond promptly to sudden faults, reducing service interruption time and improving the availability and reliability of the communication system. The real-time transmission of beam tracking commands helps the receiver quickly adjust the optical path coaxiality, ensuring stable beam tracking and reducing communication interruptions caused by beam drift. The high-frequency transmission of system status updates keeps both communicating parties synchronized with the system's operating status, facilitating preventative maintenance and fault diagnosis, improving the overall stability and efficiency of the system, and achieving efficient transmission of inter-satellite laser communication link status information, significantly improving the efficiency of inter-satellite laser communication.

[0109] In an exemplary embodiment, before the first communication satellite generates the first physical frame based on the first inter-satellite link overhead, the method further includes: determining the portion of inter-satellite information to be transmitted in the first type of inter-satellite information based on a specified multiframe structure, and obtaining the first type of inter-satellite information in the first inter-satellite link overhead, wherein the first type of inter-satellite information is transmitted using the specified multiframe structure.

[0110] In this embodiment, the specified multiframe structure refers to a structure used to carry inter-satellite information that is transmitted periodically or in batches. A multiframe is a collection of multiple base frames (i.e., basic frames). By arranging different information in the multiframe according to specific time and spatial locations, the orderly and periodic transmission of different types of information can be achieved.

[0111] Optionally, the inter-satellite slow channel in the first inter-satellite link overhead can be used for inter-satellite information transmission by defining 256 multiframes (256 base frames make up a multiframe, and periodic information can be transmitted in each multiframe).

[0112] The inter-satellite information to be transmitted refers to the information that needs to be transmitted in the current communication cycle or time window based on a specified multiframe structure in the inter-satellite communication system.

[0113] Optionally, since the first type of inter-satellite information may contain multiple parts (such as version information, orbit information, configuration information, etc.), according to the multiframe structure, this first type of inter-satellite information is not sent all at the same time, but is divided into multiple small segments that are periodically transmitted according to the time sequence.

[0114] For example, within a specific multiframe period, only version information and partial track information may be transmitted, while other information is sent in subsequent multiframe periods.

[0115] Optionally, the aforementioned inter-satellite slow channel can be designed in the second row and fourth column of the ground OTN protocol, focusing on using multiframes to transmit version information, orbit information, and other slow channel link quality and auxiliary tracking information.

[0116] In this embodiment, by specifying the multiframe structure, both communicating parties can know in advance when they will receive what type of information, which is conducive to rationally arranging the receiving and processing process and improving the orderliness of communication management. For the first type of inter-satellite information, the multiframe structure provides a fixed update cycle. The use of specifying the multiframe structure helps to rationally allocate communication link resources, avoid the waste of overhead areas, and at the same time ensure the timely transmission of key information, thereby improving the efficiency of inter-satellite link communication.

[0117] In an exemplary embodiment, the second communication satellite adjusts its beam focus based on the first inter-satellite link overhead in the first physical frame, including: in the event of an interruption of the inter-satellite laser communication link, the second communication satellite predicts the satellite position of the first communication satellite by orbit extrapolation based on the first inter-satellite link overhead in the first physical frame, and adjusts the beam focus of the second communication satellite according to the predicted satellite position and ephemeris information to restore the inter-satellite laser communication link.

[0118] In this embodiment, orbit extrapolation is a technique for predicting the future position of a satellite. Optionally, the satellite's position at a certain point in the future can be predicted based on historical satellite position data and motion models (such as Newtonian mechanics models).

[0119] Ephemeris information is a detailed set of parameters describing the changes in a satellite's position and velocity in its orbit over time. It is essential data for satellite navigation and inter-satellite communication and can be used to calculate a satellite's exact position and velocity. Optionally, ephemeris information may include all or some of the following parameters: semi-major axis (the average distance of the satellite's orbit), orbital eccentricity (a measure of orbital shape, reflecting the ellipticity of the orbit), orbital inclination (the angle between the satellite's orbital plane and the Earth's equatorial plane), right ascension of the ascending node (the angular distance between the projection of the satellite's orbital point onto the equatorial plane and the vernal equinox), perigee distance (the angular distance between the satellite's position on its orbit and its perigee (the point where the satellite is closest to Earth), and mean perigee angle (the satellite's position on its orbit relative to the ascending node, used to determine the satellite's specific position on its orbit).

[0120] In an optional embodiment, in the event of an interruption of the inter-satellite laser communication link, the second communication satellite parses the first inter-satellite link overhead from the most recently received first physical frame, obtains the orbital information and related parameters of the first communication satellite, and predicts the future orbital position of the first communication satellite by extrapolating using an orbital dynamics model based on the extracted satellite position information and ephemeris data. According to the predicted satellite position, the second communication satellite adjusts its beam focusing direction to re-align with the first communication satellite. After adjusting the beam focus, the second communication satellite attempts to re-establish the inter-satellite laser communication link and verifies whether the beam has been successfully aligned with the first communication satellite and communication has been restored by sending a test signal or a handshake request signal.

[0121] This embodiment utilizes the first inter-satellite link overhead in the first physical frame to adjust beam focus and restore the link in the event of an inter-satellite laser communication link interruption. This reduces communication delays and data loss caused by link interruption, enabling satellites to autonomously restore the link without external intervention, thus improving the resilience and stability of the inter-satellite laser communication network.

[0122] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0123] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory (ROM) / random access memory (RAM), magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0124] According to another aspect of the embodiments of this application, an inter-satellite laser communication system is also provided. This inter-satellite laser communication system can be used to implement the inter-satellite laser communication method provided in the above embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the systems described in the following embodiments are preferably implemented in software, hardware implementations, or a combination of software and hardware, are also possible and contemplated.

[0125] Figure 7 This is a structural block diagram of an optional inter-satellite laser communication system according to an embodiment of this application, such as... Figure 7 As shown, the inter-satellite laser communication system includes a first communication satellite 702 and a second communication satellite 704.

[0126] The first communication satellite 702 is used to generate a first physical frame based on the first inter-satellite link overhead, and send the first physical frame to the second communication satellite through the inter-satellite laser communication link. The first inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite.

[0127] The second communication satellite 704 is used to adjust the beam focus of the second communication satellite based on the first inter-satellite link overhead in the first physical frame, generate a second physical frame based on the second inter-satellite link overhead, and send the second physical frame to the first communication satellite through the inter-satellite laser communication link. The second inter-satellite link overhead is used to indicate the satellite trajectory of the second communication satellite.

[0128] It should be noted that the first communication satellite 702 in this embodiment can be used to perform the above step S202, and the second communication satellite 704 in this embodiment can be used to perform the above step S204.

[0129] Through the embodiments provided in this application, a first communication satellite generates a first physical frame based on a first inter-satellite link overhead, wherein the inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite. When the second communication satellite receives the first physical frame with the first inter-satellite link overhead, it can adjust its own beam focus according to the satellite trajectory information of the first communication satellite, ensuring that the laser beam accurately tracks the first communication satellite, effectively overcoming the optical path deviation caused by satellite motion and improving the robustness of inter-satellite laser communication. Simultaneously, the second communication satellite generates a second physical frame based on a second inter-satellite link overhead and sends it back to the first communication satellite via the inter-satellite laser communication link to indicate the satellite trajectory of the second communication satellite. This two-way communication mechanism ensures… This technology ensures that all participating satellites in inter-satellite communication can monitor each other's positions and motion status in real time. This is beneficial for maintaining high-quality laser links in complex space environments, thereby improving the efficiency and accuracy of data transmission. By sending physical frames between two satellites, the inter-satellite laser communication link can achieve self-calibration. By monitoring the quality of the optical signal in real time and dynamically adjusting the beam, it ensures optimal optical path coaxiality, thereby optimizing communication performance and reducing the bit error rate. This significantly improves the stability and reliability of inter-satellite communication, reduces the bit error rate, and maintains the continuity and efficiency of the laser link even in environments with rapid satellite movement. Therefore, it solves the technical problem of poor adaptability to space laser communication environments in related technologies.

[0130] In an exemplary embodiment, a first communication satellite generates a first physical frame based on specified service data and a first inter-satellite link overhead. The specified service data is service data to be transmitted from the first communication satellite to a second communication satellite. The specified service data is mapped to the payload area of ​​the first physical frame. The first inter-satellite link overhead is mapped to an inter-satellite link overhead channel, and the inter-satellite link overhead channel is the specified overhead area of ​​the first physical frame.

[0131] In an exemplary embodiment, the electrical layer of the inter-satellite laser communication link includes multiple sublayers such as optical channel payload units, optical channel data units, optical channel transmission units, and a physical layer. The payload area of ​​the first physical frame corresponds to the optical channel payload unit, and the overhead area of ​​the first physical frame includes the overhead area of ​​each of the multiple sublayers. The designated overhead area belongs to the overhead area of ​​the optical channel data unit.

[0132] In one exemplary embodiment, the overhead area is specified as at least one of the following in the overhead area of ​​the optical channel data unit: specifying a reserved field, specifying an experimental field.

[0133] In one exemplary embodiment, the reserved field is located in the second row and the first to second columns of the frame structure of the first physical frame, and the experimental field is located in the second row and the fourth column of the frame structure of the first physical frame.

[0134] In one exemplary embodiment, the overhead region of the first physical frame further includes a forward error correction overhead region, wherein the forward error correction overhead region is used to write forward error correction overhead.

[0135] In an exemplary embodiment, the inter-satellite link overhead channel includes an inter-satellite slow channel, which is an experimental field in the overhead area of ​​the first physical frame. The inter-satellite slow channel is used to transmit a first type of inter-satellite information in the first inter-satellite link overhead. The first type of inter-satellite information includes satellite orbit information, which is used to indicate the satellite trajectory of the first communication satellite.

[0136] In one exemplary embodiment, the first type of inter-satellite information further includes at least one of the following: system version information for confirming the version information used by the first communication satellite in the inter-satellite laser communication system; first link quality information for indicating the performance indicators of the inter-satellite laser communication link; and auxiliary tracking information for self-calibrating the optical path coaxiality between the second communication satellite and the first communication satellite, and indicating the avoidance angle for the second communication satellite to enter solar outage, so as to predict the time of solar outage of the second communication satellite.

[0137] In an exemplary embodiment, the inter-satellite link overhead channel further includes an inter-satellite fast channel, which is a reserved field in the overhead area of ​​the first physical frame. The inter-satellite fast channel is used to transmit second type of inter-satellite information in the first inter-satellite link overhead, and the transmission frequency of the first type of inter-satellite information is lower than the transmission frequency of the second type of inter-satellite information.

[0138] In one exemplary embodiment, the second type of inter-satellite information includes at least one of the following: optical power information, second link quality information, beam tracking instructions, real-time alarm information, and system status updates.

[0139] In an exemplary embodiment, the first communication satellite is configured to determine, based on a specified multiframe structure, a portion of the inter-satellite information currently to be transmitted from the first type of inter-satellite information, before generating the first physical frame based on the first inter-satellite link overhead, thereby obtaining the first type of inter-satellite information in the first inter-satellite link overhead, wherein the first type of inter-satellite information is transmitted using the specified multiframe structure.

[0140] In one exemplary embodiment, the first communication satellite is used to convert the first physical frame into an optical signal and send the converted optical signal to the second communication satellite through the optical transport network interface of the inter-satellite laser communication link.

[0141] In an exemplary embodiment, the second communication satellite is used to predict the satellite position of the first communication satellite by orbit extrapolation based on the first inter-satellite link overhead in the first physical frame in the event of an interruption of the inter-satellite laser communication link, and adjust the beam focus of the second communication satellite according to the predicted satellite position and ephemeris information to restore the inter-satellite laser communication link.

[0142] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0143] According to another aspect of the embodiments of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein the program executes the steps in any of the above method embodiments when it is run.

[0144] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as USB flash drives, ROMs, RAMs, portable hard drives, magnetic disks, or optical disks.

[0145] According to another aspect of the embodiments of this application, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor is configured to perform the steps of any of the method embodiments described above via the computer program. In an exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0146] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0147] According to another aspect of the embodiments of this application, a computer program product is also provided, the computer program product including a computer program / instructions containing program code for performing the method shown in the flowchart.

[0148] Figure 8 A schematic block diagram of a computer system architecture for implementing embodiments of the present application is shown. Figure 8As shown, the computer system 800 includes a Central Processing Unit (CPU) 801, which can perform various appropriate actions and processes based on programs stored in ROM 802 or programs loaded into RAM 803 from storage section 808. Random access memory 803 also stores various programs and data required for system operation. The CPU 801, ROM 802, and RAM 803 are interconnected via bus 804. Input / output (I / O) interface 805 is also connected to bus 804.

[0149] The following components are connected to I / O interface 805: an input section 806 including a keyboard, mouse, etc.; an output section 807 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 808 including a hard disk, etc.; and a communication section 909 including a network interface card such as a local area network card, modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to I / O interface 905 as needed. Removable media 811, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 810 as needed so that computer programs read from them can be installed into storage section 808 as needed.

[0150] Specifically, according to embodiments of this application, the processes described in the various method flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 809, and / or installed from removable medium 811. When the computer program is executed by central processing unit 801, it performs various functions defined in the system of this application.

[0151] It should be noted that, Figure 8 The computer system 800 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0152] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0153] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. An inter-satellite laser communication method, characterized in that, include: The first communication satellite generates a first physical frame based on the first inter-satellite link overhead and sends the first physical frame to the second communication satellite through the inter-satellite laser communication link. The first inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite. The second communication satellite adjusts its beam focus based on the first inter-satellite link overhead in the first physical frame, generates a second physical frame based on the second inter-satellite link overhead, and sends the second physical frame to the first communication satellite through the inter-satellite laser communication link. The second inter-satellite link overhead is used to indicate the satellite trajectory of the second communication satellite.

2. The method according to claim 1, characterized in that, The first communication satellite generates a first physical frame based on the first inter-satellite link overhead, including: The first communication satellite generates the first physical frame based on specified service data and the first inter-satellite link overhead. The specified service data is the service data to be sent by the first communication satellite to the second communication satellite. The specified service data is mapped to the payload area of ​​the first physical frame. The first inter-satellite link overhead is mapped to the inter-satellite link overhead channel. The inter-satellite link overhead channel is the specified overhead area of ​​the first physical frame.

3. The method according to claim 2, characterized in that, The electrical layer of the inter-satellite laser communication link includes multiple sublayers such as optical channel payload units, optical channel data units, optical channel transmission units, and a physical layer. The payload area of ​​the first physical frame corresponds to the optical channel payload unit. The overhead area of ​​the first physical frame includes the overhead area of ​​each of the multiple sublayers. The designated overhead area belongs to the overhead area of ​​the optical channel data unit.

4. The method according to claim 3, characterized in that, The designated overhead area is at least one of the following in the overhead area of ​​the optical channel data unit: a designated reserved field, a designated experimental field.

5. The method according to claim 4, characterized in that, The specified reserved field is located in the second row and the first to second columns of the frame structure of the first physical frame, and the specified experimental field is located in the second row and the fourth column of the frame structure of the first physical frame.

6. The method according to claim 3, characterized in that, The overhead area of ​​the first physical frame further includes a forward error correction overhead area, wherein the forward error correction overhead area is used to write forward error correction overhead.

7. The method according to claim 2, characterized in that, The inter-satellite link overhead channel includes an inter-satellite slow channel, which is an experimental field in the overhead area of ​​the first physical frame. The inter-satellite slow channel is used to transmit a first type of inter-satellite information in the first inter-satellite link overhead. The first type of inter-satellite information includes satellite orbit information, which is used to indicate the satellite trajectory of the first communication satellite.

8. The method according to claim 7, characterized in that, The first type of inter-satellite information also includes at least one of the following: system version information, used to confirm the version information used by the first communication satellite in the inter-satellite laser communication system; and first link quality information, used to indicate the performance indicators of the inter-satellite laser communication link. The auxiliary tracking information is used to self-calibrate the optical path coaxiality between the second communication satellite and the first communication satellite, and to indicate the avoidance angle for the second communication satellite to enter the solar outage, so as to predict the time of the solar outage of the second communication satellite.

9. The method according to claim 7, characterized in that, The inter-satellite link overhead channel also includes an inter-satellite fast channel, which is a reserved field in the overhead area of ​​the first physical frame. The inter-satellite fast channel is used to transmit the second type of inter-satellite information in the first inter-satellite link overhead, and the transmission frequency of the first type of inter-satellite information is lower than the transmission frequency of the second type of inter-satellite information.

10. The method according to claim 9, characterized in that, The second type of inter-satellite information includes at least one of the following: optical power information, second link quality information, beam tracking instructions, real-time alarm information, and system status updates.

11. The method according to claim 7, characterized in that, Before the first communication satellite generates the first physical frame based on the first inter-satellite link overhead, the method further includes: Based on a specified multiframe structure, the inter-satellite information to be transmitted in the first type of inter-satellite information is determined, and the inter-satellite information of the first type in the first inter-satellite link overhead is obtained, wherein the inter-satellite information of the first type is transmitted using the specified multiframe structure.

12. The method according to any one of claims 1 to 11, characterized in that, The step of sending the first physical frame to the second communication satellite via an inter-satellite laser communication link includes: The first physical frame is converted into an optical signal, and the converted optical signal is sent to the second communication satellite through the optical transport network interface of the inter-satellite laser communication link.

13. The method according to any one of claims 1 to 11, characterized in that, The second communication satellite adjusts its beam focus based on the first inter-satellite link overhead in the first physical frame, including: In the event of an interruption of the inter-satellite laser communication link, the second communication satellite predicts the satellite position of the first communication satellite by orbit extrapolation based on the first inter-satellite link overhead in the first physical frame, and adjusts the beam focus of the second communication satellite according to the predicted satellite position and ephemeris information to restore the inter-satellite laser communication link.

14. An inter-satellite laser communication system, characterized in that, include: A first communication satellite and a second communication satellite communicate via an inter-satellite laser communication link; wherein... The first communication satellite is configured to generate a first physical frame based on a first inter-satellite link overhead, and transmit the first physical frame to the second communication satellite via the inter-satellite laser communication link, wherein the first inter-satellite link overhead is used to indicate the satellite trajectory of the first communication satellite; The second communication satellite is configured to adjust the beam focus of the second communication satellite based on the first inter-satellite link overhead in the first physical frame, generate a second physical frame based on the second inter-satellite link overhead, and transmit the second physical frame to the first communication satellite through the inter-satellite laser communication link, wherein the second inter-satellite link overhead is used to indicate the satellite trajectory of the second communication satellite.

15. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1 to 13.

16. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the method according to any one of claims 1 to 13.

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