Marine low-orbit satellite communication system and communication method thereof

Abstract

The invention discloses a marine low-orbit satellite communication system and a communication method thereof.The marine low-orbit satellite communication system comprises a task fleet group module, a ground orbit satellite communication constellation module and a ground gateway module, the task fleet group module is composed of a plurality of task fleets, and each task fleet internally comprises a plurality of member ships; each member ship is provided with a marine low-orbit satellite communication device; the task fleet group module is connected with the earth orbit satellite communication constellation module through the marine low orbit satellite communication device, and the earth orbit satellite communication constellation module is connected with the ground gateway module. According to the method, a marine low-orbit satellite communication system is utilized, fleet users who have tasks in a sea area are divided into a plurality of sub-fleets, each sub-fleet comprises a plurality of terminal communication user ships, and each ship is matched with marine low-orbit satellite communication equipment; the restrictions of long communication voice time delay and low-rate short message data service brought to fleet users under the current condition based on high-orbit satellite communication equipment are overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of ship communication, and in particular to a ship low-orbit satellite communication system and a communication method thereof. Background Art

[0002] Satellite communication systems can be generally divided into three categories: low orbit, medium orbit and geostationary (high) orbit, based on the different altitudes of satellite orbits. Among them, low-orbit satellite communication systems have the characteristics of low communication delay and good system stability due to their low orbital altitude. Compared with the higher communication delay and lower data transmission rate characteristics of medium and high-orbit satellite communication systems, low-orbit satellite communication systems can realize satellite audio and video calls and near real-time data transmission between users, and can provide users with broadband network service functions similar to those provided by traditional telecom operators, breaking through the restrictions on users in terms of geographical use (manifested in the land area where no communication base stations are deployed, there is no network communication service), and expanding its broadband communication service scope from land users to sea users.

[0003] At present, the means of communication between users at sea mainly rely on voice communication and low-speed short message data services provided by high-orbit satellite terminal equipment or shortwave equipment. There is still a lack of effective means to provide broadband communication services to ship users in the sea area. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a ship-based low-orbit satellite communication system and a communication method thereof. By using the ship-based low-orbit satellite communication system, fleet users on mission in the sea area are divided into a number of sub-fleet, each sub-fleet includes a number of terminal communication user ships, and each ship is equipped with ship-based low-orbit satellite communication equipment, which can effectively realize the satellite broadband network communication function based on the low-orbit satellite constellation between fleet member users in the sea area (including between sub-fleet and between members within sub-fleet), thereby overcoming the constraints of extended voice communication time and low-rate short message data services brought to fleet users under the current conditions of high-orbit satellite communication equipment.

[0005] In order to solve the above technical problems, the present invention provides a ship-borne low-orbit satellite communication system, comprising a task fleet group module, a ground-orbit satellite communication constellation module and a ground gateway module, wherein the task fleet group module is composed of a plurality of task fleets, each of which includes a plurality of member ships, and each member ship is provided with a ship-borne low-orbit satellite communication device; the task fleet group module is connected to the ground-orbit satellite communication constellation module through a ship-borne low-orbit satellite communication device, and the ground-orbit satellite communication constellation module is connected to the ground gateway module.

[0006] Furthermore, the ship-borne low-orbit satellite communication equipment includes a low-orbit communication equipment application processing module, a low-orbit communication equipment satellite communication module, a UPS power supply module, an antenna module and a low-orbit satellite communication equipment system service interface module;

[0007] The low-orbit communication equipment application processing module provides the software and hardware environment required for the operation of the whole equipment;

[0008] The satellite communication module of the low-orbit communication equipment realizes the broadband satellite communication function of the equipment based on the low-orbit satellite communication network.

[0009] Furthermore, the software system in the application processing module of the low-orbit communication equipment mainly runs OpenWrt / Harmony OS; the hardware components include: main control processing unit, power module interface, SSD+mechanical dual memory, and DDR4 memory external interface.

[0010] Furthermore, the satellite communication module of the low-orbit communication equipment includes a baseband processing subsystem, an intermediate frequency processing subsystem and a power module interface; the intermediate frequency processing subsystem includes a SOC module, an SFP / QSFP data transmission interface, a GbE port and an intermediate frequency transceiver module; the baseband processing subsystem includes an FPGA accelerator, a high-speed memory, a GbE network port and a data transmission PCle interface.

[0011] Furthermore, each task fleet is divided into one parent node ship and multiple child node ships, and the roles of users within the fleet can be converted to each other in both directions.

[0012] Furthermore, the earth orbit satellite communication constellation module is composed of a number of communication satellites deployed and operating in a low-altitude orbit 500 to 2000 km above the ground.

[0013] Furthermore, the antenna module supports GNSS satellite antennas and low-orbit type satellite antennas.

[0014] A communication method for the above-mentioned ship-borne low-orbit satellite communication system comprises the following steps:

[0015] Step 1: The terminal device system is started, and the main control application module and the low-orbit satellite communication network system module are loaded in sequence; the latter module software program is triggered by the former main control application module program to load the module software after the former main control application module software program is successfully loaded;

[0016] Step 2: Orderly communication among fleet members;

[0017] Step 3: Implement point-to-point voice, audio and video communications between fleets based on a low-orbit satellite communication equipment system;

[0018] Step 4: Develop a public-private data mechanism for switching fleets using data from exclusive and preemptive public communication services;

[0019] Step 5: Pre-condition preparation for the member ships of the task of changing the course;

[0020] Step 6: Safety verification of member ships belonging to multiple fleets: The parent node user of the destination fleet obtains three sets of data information, namely the initial fleet identification code, the destination fleet identification code, and the identification code of the node ship to be added to the new fleet, and further performs safety verification of the sub-node member ships belonging to the multiple fleets;

[0021] If the security verification fails, the parent node of the destination fleet will refuse the node ship that intends to join the new fleet to obtain the right to participate in the orderly communication within it. At this time, the node ship will continue to stay in the initial fleet and maintain orderly communication with the initial fleet.

[0022] If the security verification is passed: the destination fleet parent node will complete the setting of the verification pass identification result and send a confirmation message to the initial fleet parent node; the initial fleet parent node will remove the node ship user that is about to leave the fleet from its internal communication based on this confirmation message, and send a confirmation message to the destination fleet parent node; the fleet parent node user will set the node ship to join the fleet and participate in its internal communication business based on this confirmation message, and on this basis, execute step seven.

[0023] Step 7. Synchronize with the public communication data of the newly joined fleet: The purpose of information sharing is achieved by automatically synchronizing the public communication data within the newly joined fleet. The data synchronization network channel uses the data channel of the low-orbit broadband satellite network. Regarding the public communication data within the fleet, it is set according to its importance as the must-know public data of the new fleet and the graded selected public communication business historical data of the new fleet.

[0024] Furthermore, the specific steps of orderly communication among the fleet members in step 2 are as follows:

[0025] Step 2.1: First, the fleet needs to be divided into a pilot ship and multiple member ships, that is, one communication system parent node - multiple communication system child nodes;

[0026] Step 2.2: Execute orderly communication services between parent-child nodes of users within the fleet;

[0027] Step 2.2.1: The pilot ship user enters the low-orbit satellite communication equipment system as a parent node;

[0028] Step 2.2.2: Several member ship users enter the low-orbit satellite communication equipment system as sub-nodes;

[0029] Step 2.2.3: Execute orderly communication within the fleet; as for the functional design of orderly communication within the fleet, it includes 3 branches: 1. Normal point-to-point private communication service; 2. Exclusive one-to-many ordinary public communication service; 3. Preemptive one-to-many public communication service.

[0030] Furthermore, the specific steps of the precondition preparation for generating the member ship of the heading change task in step 5 are as follows:

[0031] It is divided into two steps: from the initial fleet to the destination fleet and from the destination fleet to the initial fleet;

[0032] From the initial fleet to the destination fleet: First, the initial fleet, due to mission requirements, actively initiates a request to change the course of a member ship to the pilot ship of the destination fleet, i.e., the parent node; secondly, after obtaining a response from the pilot ship of the destination fleet, i.e., the parent node, the identification code of the member ship to be changed is notified to the destination fleet;

[0033] Destination fleet to initial fleet: First, the initial fleet passively receives the task request from the parent node user of the destination fleet, i.e. the pilot ship, and notifies the identification code of the pilot ship of the destination fleet, i.e. the parent node;

[0034] Finally, continue to repeat the steps from the initial fleet to the destination fleet.

[0035] The beneficial effects of the present invention are:

[0036] The present invention is based on the low-orbit satellite communication equipment system, and sets up a business system for orderly communication among fleet members, and also sets up a public-private data mechanism involved in switching fleets. This enables the broadband satellite communication function between fleet users based on the low-orbit satellite communication equipment terminal system (relative to the narrowband satellite communication in medium and high orbits); in the fleet user communication business scenario, it can support orderly communication between fleets and within fleet members, as well as data security and data information synchronization sharing services involved in the public-private data mechanism based on this. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the present invention;

[0038] Figure 2 It is a structural schematic diagram of a low-orbit satellite communication device for ships in a specific embodiment;

[0039] Figure 3 is a flow chart of the present invention;

[0040] Figure 4 It is a flow chart of a communication method of a low-orbit communication device for ship in a specific embodiment. DETAILED DESCRIPTION

[0041] like Figure 1As shown, the present invention provides a ship-borne low-orbit satellite communication system, which is mainly composed of three modules: 1. A task fleet group module: divided into n task fleets, and each fleet includes a number of member ships (all equipped with ship-borne low-orbit satellite communication equipment); 2. A low-orbit satellite communication constellation module; 3. A ground signal gateway module. To realize the basic process of the communication system business: first, the ground signal gateway module is responsible for controlling and operating the low-orbit satellite communication constellation module, waiting for the low-orbit device terminal user to access (similar to the network operator operating and controlling the 4 and 5G communication base stations through the background management center, waiting for the user's mobile phone to be turned on and connected to the network); secondly, the task fleet group module uses the low-orbit communication device user to turn on the phone, and through the wireless link, establishes a space-ground wireless network with the communication base station deployed in the low-orbit satellite communication constellation module (similar to the mobile phone user being able to successfully access the operator's network); finally, a specific communication terminal user in the task fleet group module initiates a broadband satellite communication service request, which is accessed and forwarded by the communication base station built into the low-orbit satellite communication constellation module to realize broadband satellite communication services (including real-time voice, multimedia audio and video and message data) to other low-orbit device terminal users.

[0042] Regarding the task fleet module, in the n task fleets designed in the scheme, each member ship of each fleet is equipped with marine low-orbit satellite communication equipment, which can be connected to the low-orbit satellite communication constellation module to realize satellite broadband communication function. Each fleet is designed to have one parent node ship and multiple child node ships, that is, a one-to-many mode. This mode is conducive to orderly communication within the fleet, that is, only the parent node ship can send public information within the fleet to the member ships, avoiding the existence of multiple message sources at the same time (such as Figure 3 As shown in the exclusive service in the above example, multiple orders are prevented) which may cause confusion in the information received by other member ship users. Furthermore, the roles of users within the fleet can be converted in both directions: 1. When a member child node ship within the fleet (if it is a parent node ship, the parent->child node role conversion is performed to avoid confusion in the original fleet’s internal communications due to parent node role restrictions) has to enter another new fleet due to changes in mission requirements, the data synchronization design is used to update the public information data of the ship users and the newly joined fleet, so as to timely grasp the public and necessary historical communication data information within the fleet. 2. When a fleet child node user needs to publicly broadcast a notification to the fleet’s internal users due to an emergency, a preemptive short-term emergency communication service is performed (such as Figure 3 (as shown in the preemptive service).

[0043] The low-orbit satellite communication constellation module is composed of several communication satellites deployed and operating in low-altitude orbits 500 to 2000 km from the ground. It is mainly used to provide broadband communication base station services in the Ka or SC frequency band to ground or marine users (realizing broadband satellite voice, video, data, etc.). The function of the ground communication gateway module is mainly used to operate and control the low-orbit satellite communication constellation module, including attitude adjustment and status control of the low-orbit satellite communication constellation module.

[0044] The task fleet module consists of several task fleets, each of which includes several member ships, each of which is equipped with marine low-orbit satellite communication equipment. Figure 2 The figure shows the specific structure of the ship's low-orbit satellite communication equipment, which mainly includes 4 component modules and 1 equipment business interface module, namely: low-orbit communication equipment application processing module, low-orbit communication equipment satellite communication module, UPS power supply module, antenna module, low-orbit satellite communication equipment system business interface module.

[0045] about Figure 2 The main function of the low-orbit communication equipment application processing module is to provide the software and hardware environment required for the operation of the whole equipment. The software system mainly runs OpenWrt / Harmony OS (the purpose of choosing open source or domestic operating systems is to avoid unknown backdoor vulnerabilities and intellectual property disputes). The hardware components mainly include: the main control processing unit, which is mainly used for the control and operation functions of the software system, similar to the role of the CPU in a PC; the power module interface, which is mainly used to provide power to this module; SSD+mechanical dual storage, consisting of an SSD solid-state hard drive and a 7200-speed mechanical hard drive. The fast reading characteristics of the SSD solid-state hard drive are used to run OpenWrt / Harmony OS, and the data loss characteristics of the mechanical hard drive are used to store data information; DDR4 memory, a large-capacity memory with a frequency of 3200MHz is selected; external interface (interface for connecting external devices): Gbe network port, i.e., Gigabit network port, Video, i.e., video interface, DP / HDMI, used as an interface for audio, video data and other data acquisition devices, GNSS interface, i.e., global navigation interface, mainly used to connect GNSS antennas (such as Figure 2 The device system can use GPS, BeiDou and other satellite networks to realize positioning functions.

[0046] about Figure 2 The satellite communication module of low-orbit communication equipment has the main function of realizing the broadband satellite communication function of the equipment based on the low-orbit satellite communication network (relative to the narrowband satellite communication in medium and high orbits). Its main components include: baseband processing subsystem, intermediate frequency processing subsystem, and power module interface.

[0047] The intermediate frequency processing subsystem mainly realizes the processing and transceiver functions of the intermediate frequency signal. It consists of a SOC module (system on chip, i.e. a hardware chip integrating CPU, GPU and other modules, which mainly functions like a host system in a PC), an SFP / QSFP interface (i.e. a pluggable high-speed data transmission interface, used to connect the SOC and the intermediate frequency transceiver module data interface), a GbE port (i.e. a G-bit network port) and an intermediate frequency transceiver module (connected to the SOC module and Figure 2 [4] It is connected to a low-orbit antenna and is used to receive and send intermediate frequency signals).

[0048] Among them, the baseband processing subsystem consists of an FPGA accelerator (based on the secondary development of Xilinx FPGA chips, used for the role of the main control system), high-speed memory (DDR5 type high-frequency memory is selected), GbE network port (i.e. G-bit high-speed network port), and PCle interface (used to connect PCle interface type data transmission).

[0049] Power module interface, used to connect Figure 2 UPS power module, used to supply Figure 2 Power supply for satellite communication modules of medium and low orbit communication equipment.

[0050] about Figure 2 UPS power module is mainly used to Figure 2 Provides power for application processing modules of medium and low orbit communication equipment and satellite communication modules of low orbit communication equipment.

[0051] about Figure 2 Antenna module, supporting GNSS satellite antenna and low-orbit type satellite antenna.

[0052] about Figure 2 Low-orbit satellite communication equipment system business interface module, this interface is mainly used to support other external devices, including data acquisition equipment, multimedia audio and video equipment, headphones, microphones, etc.

[0053] Will Figure 2 Based on the low-orbit satellite communication equipment shown in the figure, and placed in the fleet user business process, the communication method of the ship's low-orbit satellite communication system is further explained, such as Figure 3 As shown, the steps mainly include:

[0054] Step 1: The beginning of system process design, such as Figure 3 As shown in the figure, it is located at the starting point of the service. First, the terminal device starts the OpenWrt / Harmony OS system and loads the main control application module and the low-orbit satellite communication network system module in sequence. After that, it means that the device system has completed access to the low-orbit satellite network and entered the device system standby state. At this point, the orderly communication service among the fleet members can be carried out ( Figure 3) and real-time voice and video communication services with other fleets (pilot ships) (such as Figure 3 as shown in step 3).

[0055] Step 2: About Figure 3 In terms of business process, the fleet needs to be divided into 1 pilot ship and multiple member ship roles, that is, 1 communication system parent node - multiple communication system child nodes. Orderly communication services are performed between parent and child nodes of users within the fleet: 1. The pilot ship user enters the low-orbit satellite communication equipment system as a parent node, 2. Several member ship users enter the low-orbit satellite communication equipment system as child nodes, and 3. Orderly communication within the fleet is performed. In terms of the functional design of orderly communication within the fleet, it includes 3 branches: 1. Normal point-to-point private communication service (this service generates private communication data, mainly used for private communication between two node users); 2. Exclusive one-to-many ordinary public communication service (this service generates public communication data, mainly used for parent node users->child node users to send broadcast audio, video and short messages, during which the child node users are blocked), 3. Preemptive one-to-many public communication service (this service generates public communication data, mainly used for child node users to inform special situation data information to parent node users and other child node users in an emergency).

[0056] Step 3: Point-to-point voice, audio and video communication based on the low-orbit satellite communication equipment system can be performed between fleets. It should be noted that for orderly communication between fleets, it is necessary to limit it to the parent node and the parent node (pilot ship) to avoid the situation where the parent node of fleet A and the child node of fleet B directly conduct public communication services, which will cause inconsistency in the public communication data of other child node users of fleet B. If necessary, point-to-point private communication between the parent nodes of the fleet can be performed.

[0057] Step 4: Design of public-private data mechanism due to the change of user tasks and the need to switch fleets. The data information comes from exclusive and preemptive public communication services. This mechanism mainly includes three steps: 1. Preparation of preconditions for member ships to change course; 2. Safety verification of member ships belonging to multiple fleets; 3. Synchronization with public communication data of newly joined fleets.

[0058] Step 1, such as Figure 3 As shown in step 5, the design has two process directions: initial fleet -> destination fleet and destination fleet -> initial fleet.

[0059] Initial Fleet->Destination Fleet: First, the initial fleet, due to mission requirements, actively initiates a request to change the course of a member ship to the pilot ship (parent node) of the destination fleet (e.g. Figure 3[1][2] in step 5); secondly, after obtaining the response from the pilot ship (parent node) of the destination fleet, the identification code of the member ship that intends to change the course is notified to the destination fleet. It should be noted that the member ship that intends to change the course within the initial fleet is also divided into two situations: upstream and downstream. That is, the pilot ship (parent node) can go downstream to specify the member ship (child node), or a member ship (child node) can go upstream to actively apply to the pilot ship (parent node).

[0060] Destination fleet->initial fleet: First, the initial fleet passively receives the destination fleet (the parent node user of the pilot ship) due to task requests (such as Figure 3 In step 5 [3][4]), the identification code of the pilot ship of the destination fleet (the parent node) is notified. The two actually follow the same path. Figure 3 The process of step 3 in the above process is repeated from initial fleet to destination fleet.

[0061] Step 2, as shown in step 6 in the figure, after step 1, the parent node user of the destination fleet can obtain three sets of data information, including the initial fleet identification code, the destination fleet identification code, and the identification code of the node ship to be added to the new fleet, and further perform the safety verification of the child node member ship belonging to the multi-fleet, such as Figure 3 As shown in step six. The purpose of this step is to prevent the child node member ship from being in two fleets at the same time. On the one hand, it prevents the public communication data information within the initial fleet from being received by the child node ship and causing data information leakage. On the other hand, for the child node ship itself, receiving the public information from both the new and old fleets at the same time may easily cause confusion in the data information received by the child node ship users. In terms of process design, the initial fleet parent node sends the initial fleet parent node-child node ship identification code to the destination fleet parent node; the destination fleet parent node verifies the legitimacy of the identification code by comparing the three sets of data obtained in step 1 (initial fleet identification code, destination fleet identification code, and identification code of the node ship to be added to the new fleet);

[0062] When the legitimacy verification fails, the parent node of the destination fleet refuses the node ship that intends to join the new fleet to obtain the right to participate in its internal orderly communication. At this time, the node ship continues to stay in the initial fleet and maintains orderly communication with the initial fleet.

[0063] When the legitimacy verification is passed, then: 1. The destination fleet parent node will complete the setting of the verification pass identification result and send a confirmation message to the initial fleet parent node; 2. The initial fleet parent node will strip the node ship user that is about to leave the fleet of its internal communication based on this confirmation message, and send a confirmation message to the destination fleet parent node; 3. The fleet parent node user will set the node ship to join the fleet and participate in its internal communication business based on this confirmation message, and on this basis, execute step 3.

[0064] Step 3, automatically trigger the execution Figure 3 As shown in step 7, the purpose of information sharing is achieved by automatically synchronizing the internal public communication data (already existing) of the newly added fleet, and the data synchronization network channel is the data channel of the low-orbit broadband satellite network. Regarding the internal public communication data of the fleet, it is set as the must-know new fleet public data and the graded optional new fleet public communication business history data according to its importance. The purpose of this design is to take into account the needs of new users for data integrity and flexibility in obtaining the internal public communication history data of the fleet.

[0065] The present invention will be further explained with reference to specific embodiments and accompanying drawings. Figure 4 As shown, a specific embodiment of a method for designing a low-orbit communication equipment system for a ship is disclosed, which mainly includes the following steps:

[0066] 1. Design ship-borne low-orbit satellite communication equipment, whose main components include: equipment application processing module, low-orbit satellite communication module, UPS power module, antenna module and service interface module.

[0067] 2. Start the OpenWrt / Harmony OS system of the marine low-orbit satellite communication terminal, and successfully load the main control application module software and the low-orbit satellite system communication module in sequence. At this point, the system software, hardware and low-orbit satellite network access service initialization work of this solution is completed.

[0068] 3. Begin to implement orderly internal communications among fleet members based on a low-orbit satellite communication network environment.

[0069] 4. Orderly internal communication among fleet members, including three business branches: Under normal circumstances, the pilot ship conducts exclusive one-to-many public communication services for internal member ships, including voice, audio and video, and data information broadcasting services. The internal public communication data of the fleet generated under this service will serve as the data source for the business processes described in the subsequent public-private data mechanism.

[0070] 5. Orderly internal communication among fleet members, including 3 business branches: Under special circumstances, a member ship within the fleet performs preemptive public emergency communication services to other members. The public communication data within the fleet generated under this service will serve as the data source for the business processes described in the subsequent public-private data mechanism.

[0071] 6. Orderly internal communication among fleet members, including 3 business branches: Under normal circumstances, members within the fleet can perform point-to-point private communication services, which generate private communication data and do not participate in the subsequent data business process of the public-private data mechanism.

[0072] 7. If a member ship in the fleet changes its course and switches to another fleet due to new mission requirements, the public-private data mechanism will be triggered.

[0073] 8. The three serial processes under the public-private data mechanism are: first, the two-way task request of the initial fleet / destination fleet, which determines the three sets of data information, including the initial fleet identification code, the destination fleet identification code, and the node ship identification code to be added to the new fleet. Figure 3 See step 5 in the following sections for more information.

[0074] 9. Further, the member ships are required to implement the multi-fleet safety mechanism, see Figure 3 If the verification fails, as shown in 9->3, continue to maintain internal communication with the initial fleet.

[0075] 10. On the basis that the node ship to be added to the new fleet passes the verification of the subordinate multi-fleet safety mechanism, it will further automatically trigger the synchronization with the internal public data of the new fleet, see Figure 3 As described in step seven.

[0076] In summary, the present invention is based on the low-orbit satellite communication equipment system, and sets up a business system for orderly communication among fleet members. Furthermore, it sets up a public-private data mechanism involved in switching fleets, and makes corresponding setting instructions. By implementing this solution, the broadband satellite communication function between fleet users based on the low-orbit satellite communication equipment terminal system (relative to the narrowband satellite communication in medium and high orbits) can be realized; further, in the fleet user communication business scenario, it can support orderly communication between fleets and within fleet members, as well as data security and data information synchronization sharing services involved in the public-private data mechanism based on this.

Claims

1. A low-orbit satellite communication system for ships, characterized in that: It includes a task fleet group module, a ground orbit satellite communication constellation module and a ground gateway module. The task fleet group module is composed of several task fleets, each task fleet includes several member ships, and each member ship is equipped with a ship-used low-orbit satellite communication device; the task fleet group module is connected to the ground orbit satellite communication constellation module through a ship-used low-orbit satellite communication device, and the ground orbit satellite communication constellation module is connected to the ground gateway module.

2. A marine low-orbit satellite communication system according to claim 1, characterized in that: The ship-borne low-orbit satellite communication equipment comprises a low-orbit communication equipment application processing module, a low-orbit communication equipment satellite communication module, a UPS power module, an antenna module and a low-orbit satellite communication equipment system service interface module; the UPS power module is respectively connected to the low-orbit communication equipment application processing module and the low-orbit communication equipment satellite communication module, the antenna module is respectively connected to the low-orbit communication equipment application processing module and the low-orbit communication equipment satellite communication module, and the low-orbit satellite communication equipment system service interface module is connected to the low-orbit communication equipment application processing module; The low-orbit communication equipment application processing module provides the software and hardware environment required for the operation of the whole equipment; The satellite communication module of the low-orbit communication equipment realizes the broadband satellite communication function of the equipment based on the low-orbit satellite communication network.

3. A marine low-orbit satellite communication system according to claim 2, characterized in that: The software system in the application processing module of the low-orbit communication equipment runs OpenWrt / Harmony OS; the hardware components include: a main control processing unit, a power module interface, an SSD+mechanical dual memory, and a DDR4 memory external interface.

4. A marine low-orbit satellite communication system according to claim 2, characterized in that: The satellite communication module of the low-orbit communication equipment includes a baseband processing subsystem, an intermediate frequency processing subsystem and a power module interface. The intermediate frequency processing subsystem includes a SOC module, an SFP / QSFP data transmission interface, a GbE port and an intermediate frequency transceiver module; the baseband processing subsystem includes an FPGA accelerator, a high-speed memory, a GbE network port and a data transmission PCle interface.

5. A low-orbit satellite communication system for ships according to claim 1, characterized in that: Each task fleet is divided into one parent node ship and multiple child node ships, and the roles of users within the fleet are bidirectionally convertible.

6. A low-orbit satellite communication system for ships according to claim 1, characterized in that: The earth orbit satellite communication constellation module is composed of a number of communication satellites deployed and operated in a low-altitude orbit 500 to 2000 km above the ground.

7. A low-orbit satellite communication system for ships according to claim 2, characterized in that: The antenna module supports GNSS satellite antennas and low-orbit type satellite antennas.

8. A communication method for a low-orbit satellite communication system for a ship as claimed in claim 1, characterized in that: The steps include: Step 1: Start the terminal device system and complete the system software service initialization work; Step 2: Orderly communication among fleet members; Step 3: Implement point-to-point voice, audio and video communications between fleets based on a low-orbit satellite communication equipment system; Step 4: Develop a public-private data mechanism for switching fleets using data from exclusive and preemptive public communication services; Step 5: Pre-condition preparation for the member ships of the task of changing the course; Step 6: Safety verification of member ships belonging to multiple fleets: The parent node user of the destination fleet obtains three sets of data information, namely the initial fleet identification code, the destination fleet identification code, and the identification code of the node ship to be added to the new fleet, and further performs safety verification of the sub-node member ships belonging to the multiple fleets; If the security verification fails, the parent node of the destination fleet will refuse the node ship that intends to join the new fleet to obtain the right to participate in the orderly communication within it. At this time, the node ship will continue to stay in the initial fleet and maintain orderly communication with the initial fleet. If the security verification is passed: the destination fleet parent node will complete the setting of the verification pass identification result and send a confirmation message to the initial fleet parent node; the initial fleet parent node will remove the node ship user that is about to leave the fleet from its internal communication based on this confirmation message, and send a confirmation message to the destination fleet parent node; the fleet parent node user will set the node ship to join the fleet and participate in its internal communication business based on this confirmation message, and on this basis, execute step seven. Step 7. Synchronize with the public communication data of the newly joined fleet: The purpose of information sharing is achieved by automatically synchronizing the public communication data within the newly joined fleet. The data synchronization network channel uses the data channel of the low-orbit broadband satellite network. Regarding the public communication data within the fleet, it is set according to its importance as the must-know new fleet public data and the graded selected new fleet public communication business historical data.

9. The communication method of a low-orbit satellite communication system for a ship according to claim 8, characterized in that: The specific steps of orderly communication among the fleet members in step 2 are as follows: Step 2.1: First, the fleet needs to be divided into a pilot ship and multiple member ships, that is, one communication system parent node - multiple communication system child nodes; Step 2.2: Execute orderly communication services between parent-child nodes of users within the fleet; Step 2.2.1: The pilot ship user enters the low-orbit satellite communication equipment system as a parent node; Step 2.2.2: Several member ship users enter the low-orbit satellite communication equipment system as sub-nodes; Step 2.2.3: Execute orderly communication within the fleet; as for the functional design of orderly communication within the fleet, it includes 3 branches:

1. Normal point-to-point private communication service; 2. Exclusive one-to-many ordinary public communication service; 3. Preemptive one-to-many public communication service.

10. The communication method of a low-orbit satellite communication system for a ship according to claim 8, characterized in that: The specific steps for preparing the preconditions for the member ship of the task of changing the course in step 5 are as follows: It is divided into two steps: from the initial fleet to the destination fleet and from the destination fleet to the initial fleet; From the initial fleet to the destination fleet: First, the initial fleet, due to mission requirements, actively initiates a request to change the course of a member ship to the pilot ship of the destination fleet, i.e., the parent node; secondly, after obtaining a response from the pilot ship of the destination fleet, i.e., the parent node, the identification code of the member ship to be changed is notified to the destination fleet; Destination fleet to initial fleet: First, the initial fleet passively receives the task request from the parent node user of the destination fleet, i.e. the pilot ship, and notifies the identification code of the pilot ship of the destination fleet, i.e. the parent node; Finally, continue to repeat the steps from the initial fleet to the destination fleet.

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