A lightweight software simulation system suitable for space routing algorithm research

Abstract

A lightweight software simulation system suitable for space routing algorithm research, comprising a system configuration module, a simulation model module, a routing simulation module, a file output module, a performance analysis module, a visual display module and a data management module, wherein: the system configuration module is used for inputting various initial parameters, including simulation scenarios, communication capabilities, algorithm protocols and communication services; the simulation model module is used for link calculation and constellation topology construction; the routing simulation module is used for routing calculation, updating and maintaining routing tables, and routing forwarding; the file output module is used for recording the original files of the required results; the performance analysis module is used for statistical analysis of performance indicators in the simulation process; the visual display module is used for displaying node and system running state and running results; the data management module is used for storing data generated by simulation.

Description

Technical Field

[0001] This invention relates to the field of network simulation technology in space communication scenarios, and develops a simulation platform that supports the verification and demonstration of key technologies in space networks, and provides a lightweight software simulation system suitable for research on space routing algorithms. Background Technology

[0002] Space network communication technologies have attracted increasing attention in recent years. System simulation and protocol verification are of great significance for space network system design and satellite equipment development. Developing a software simulation platform that supports the verification and demonstration of key space network technologies, simulating the space communication environment, customizing service communication schemes, and testing the performance of algorithms and protocols can provide support for early scheme optimization and system demonstration in product engineering, thereby accelerating the development process.

[0003] Most existing, relatively complete space communication simulation platforms are testbeds or hardware-in-the-loop (HIL) simulation platforms. However, the development costs of testbeds and various HIL simulation devices are enormous, and establishing a centralized, unified large-scale simulation platform is very inefficient and not easily accessible to most researchers. Software simulation can basically meet the requirements in the experimental verification phase of low-Earth orbit satellite development, but most existing space network software simulation platforms focus on simulating link characteristics and lack methods for simulating the entire network.

[0004] Furthermore, the highly dynamic nature of satellite constellation topologies, the heterogeneous and limited resources, and the uneven distribution of network service capabilities mean that traditional routing protocols used in terrestrial networks are no longer suitable for low-Earth orbit (LEO) satellite communication networks. This has led to extensive research by scholars both domestically and internationally on LEO satellite routing technologies to propose new routing protocols applicable to the space network environment. However, different simulation platforms have different integration methods, requiring researchers to create satellite constellations, construct network topologies, and configure simulation environments themselves for space network simulations. Existing simulation platforms also struggle to flexibly configure various routing algorithms, typically requiring users to reimplement a custom routing module within the simulation platform and integrate the routing code. The lack of a flexible simulation platform compatible with various space network routing algorithms results in low research efficiency.

[0005] Most of the aforementioned simulation platforms utilize satellite toolkits to construct satellite communication networks, forming XML configuration files with satellite network topology, link duration, and link length. They also use satellite toolkits to visualize node and link status during the simulation process. However, existing satellite toolkits are very expensive; for example, STK (Satellite Tool Kit) is no longer available to China in its latest version. Therefore, there is a lack of low-cost, configurable orbit calculation and constellation visualization methods that can basically meet the needs of network software simulation, providing an intuitive understanding of satellite trajectory structure and its impact on constellation behavior. Summary of the Invention

[0006] Objective: To provide a lightweight, open, and scalable simulation system for space routing algorithm simulation, reducing the cost and improving the efficiency of low-Earth orbit satellite R&D and experimental verification. This simulation system can independently calculate inter-satellite and satellite-to-ground visibility relationships without relying on satellite toolkits, configure pre-planned network topologies as needed, and visualize network simulation scenarios, processes, and results, allowing users to intuitively understand the structure of satellite trajectories and their impact on constellation behavior. Simultaneously, it supports static and dynamic space routing algorithm simulation, and can be configured to meet the operating environments and conditions of different types of routing algorithms, basically satisfying the routing simulation needs of space networks. This simulation system provides open interfaces, allowing users to customize relevant modules, scenarios, services, algorithms, node configurations, etc., according to their needs. It supports communication between real physical nodes and simulated nodes and enables network monitoring and analysis.

[0007] Technical Solution: To achieve the above objectives, this invention proposes a method for implementing a lightweight software simulation system suitable for spatial routing algorithm research, such as... Figure 1 As shown, it mainly includes a system configuration module, a simulation model module, a routing simulation module, a file output module, a performance analysis module, a visualization module, and a data management module. It involves the implementation of simulation elements at various levels of satellite scenarios and space networks. The functional composition of each module is as follows:

[0008] System configuration module: used for inputting various initial parameters, including simulation scenarios (number of satellite nodes, number of ground nodes, basic satellite orbit parameters, satellite antenna parameters, ground antenna parameters, inter-satellite visibility, etc.), communication capabilities (rate, data format, etc.), algorithm protocols (routing protocols, time slot allocation, etc.), and communication services (service type, service priority, etc.).

[0009] Simulation model module: used for link calculation and constellation topology construction, including calculation of inter-satellite distance and satellite-to-ground distance at different times, and determination of inter-satellite and satellite-to-ground visibility relationships, and construction of constellation according to the planned topology.

[0010] The routing simulation module implements the functions of route calculation, updating and maintaining the routing table of the routing protocol selected by the system configuration module, and performs route forwarding by querying the next-hop address and corresponding network interface according to the routing table.

[0011] File output module: Used to record the results required at the end of the simulation and generate the original file for subsequent processing.

[0012] Performance Analysis Module: This module processes the files output by the file output module, calculates performance metrics such as packet arrival rate, packet loss rate, average end-to-end latency, latency jitter, and throughput, and performs performance analysis on these metrics.

[0013] Visualization module: used to display the running status and results of nodes and systems during the simulation process, including visualization of ground stations and satellite nodes, constellation topology, communication path visualization, and link utilization visualization.

[0014] Data Management Module: This module stores the data generated during the simulation locally, including intermediate and final results during the simulation process, allowing users to easily find the simulation data they need.

[0015] In the process of implementing the above-mentioned functions, combined with Figure 2 As shown, the system configuration module, as the input to the entire simulation platform, transmits configuration data to the data management module. The simulation model module interacts with the system configuration module through the data management module to obtain ground station and satellite location information, generate simulation scenarios, perform visibility relationship calculations, construct simulation links based on the planned network topology, and transmit the topology information to the data management module. The scenarios generated by the simulation model module are used by the routing simulation module to install corresponding channels on the satellite links and configure the IP addresses of each receiving and forwarding port. Based on the service model and algorithm model determined by the system configuration module, it performs routing algorithm simulation. During the routing simulation process, path information and other results are transmitted to the file output module through the data management module. The performance analysis module reads the information from the file output module to perform network performance analysis. The visualization module reads node information, topology information, path information, network performance analysis results, etc., from the data management module for data display. The specific configuration is achieved through the following steps:

[0016] Step 1: Parameter Configuration and Constellation Construction

[0017] 1) The establishment of the satellite constellation and ground stations involves determining the specific position of each satellite by inputting the number of orbits in the constellation, the number of satellites in each orbit, and the orbital inclination, based on satellite design specifications or actual data. Without relying on satellite toolkits, celestial mechanics models and numerical integration methods are used to determine the position and velocity changes of the satellites during the simulation time. At the same time, the six orbital elements of the satellites (semi-major axis, eccentricity, orbital inclination, right ascension of the ascending node, argument of perigee, and true anomaly) are calculated, generating a two-line element orbital report (TLE) file containing the corresponding satellites. The ground stations use their latitude and longitude as input to calculate the position of each ground station in the three-dimensional coordinate system.

[0018] 2) Visibility calculation: During the creation of satellite nodes, the changes in inter-satellite distance and visibility caused by the dynamics of satellites have been realized. The simulation duration is divided into several time slices as needed. For each time slice, the visible distance range of inter-satellite links and satellite-to-ground links is calculated according to formulas 1 to 3 to determine whether satellites and ground stations are within the visible range at the current moment. Then, the visibility relationship of continuous time is generated based on all time slices to replace the link communication time calculation of the satellite toolkit.

[0019]

[0020]

[0021]

[0022] Among them, L MinISL R is the shortest visible distance for inter-satellite links; M is the Earth's radius; α is the orbital altitude; L is the satellite elevation angle; MaxISL β is the maximum visible distance of the inter-satellite link; H is the atmospheric altitude; β is the ground station elevation angle; L MaxGSL This represents the maximum visible distance between the satellite and the ground.

[0023] 3) Network topology construction: First, each satellite in the constellation is assigned a number according to its orbit and its relative position within the orbit. Users can perform topology planning to generate the required network topology. Satellites with different numbers can construct network topologies according to the planned constellation configuration. Topologies that are visible on a single orbit, topologies that are visible on multiple orbits, and topologies that are visible when they are close to each other can be constructed.

[0024] Step 2: Spatial Network Routing Simulation

[0025] In low-Earth orbit (LEO) satellite networks, satellite nodes move periodically, causing the topology to constantly change, yet it remains predictable. To address this characteristic, routing algorithms are categorized into two main types based on their routing table update mechanisms: static routing algorithms and dynamic routing algorithms. Static routing algorithms do not consider changes in network topology, dividing the satellite network in both time and space; dynamic routing algorithms calculate and update the routing table in real-time based on information transmission within the network, flexibly adapting to changes in network topology and load.

[0026] For different types of routing algorithm implementation mechanisms, this simulation platform provides corresponding modules to meet the operating conditions of static and dynamic network topology routing algorithms. Users can configure the routing module of the simulation platform into their own developed routing module according to the specific implementation details of the routing algorithm to be simulated, and build the required simulation environment without redefining the routing module themselves. It supports configurable parameters, such as the maximum number of hops, the maximum bandwidth, and the minimum latency of the route, which users can adjust according to different network requirements. The routing algorithm is efficient and scalable, and can effectively cope with the needs of large-scale networks.

[0027] The simulation platform includes a static network topology routing module responsible for calculating the next-hop path from each satellite to all other satellite nodes, prioritizing path selection based on hop count, and choosing the optimal path based on latency when hop counts are equal. It also includes a routing table management module responsible for managing and updating the routing table of each node. When the network topology changes, it recalculates the routing path and broadcasts the updated routing table throughout the network to ensure consistency across all nodes. To facilitate interaction and data transmission between modules, interfaces between the modules are defined and implemented, including input / output interfaces and data format definitions.

[0028] The simulation platform provides a dynamic network topology routing module that enables each node to periodically send HELLO probe messages to detect the connection status of neighboring nodes. When the current state in the neighbor table differs from the previous state, the network topology is modified, and the route is recalculated based on the topology update. To prevent loops, a broadcast mechanism is added. When the inconsistency between the previous and current states in the neighbor table is found and the routing table needs to be updated, the information of this changed link (the nodes at both ends of the link and their previous or current states) is broadcast to the entire network to inform other nodes to update the topology synchronously and recalculate the routing path.

[0029] The system provides interfaces for interaction between various modules: First, the routing algorithm module can call the network topology interface to obtain network topology information. This interface provides basic network topology information, such as the number of nodes, network topology, link bandwidth, etc. This information helps the routing algorithm module calculate the optimal routing path. Second, the routing algorithm module updates the routing table through the routing table management interface. The routing table management module is responsible for maintaining and updating the routing table, and it can update the routing table based on the information provided by the network topology interface. The routing table management module can also calculate the routing path based on the information provided by the routing algorithm interface. Finally, the routing algorithm module sends the updated routing table to the entire network through the network broadcast interface. This interface is responsible for broadcasting the routing table information to the entire network so that other nodes can obtain the latest routing table information in a timely manner. Simultaneously, the routing algorithm module can also use this interface to obtain routing table information sent by other nodes in order to update its local routing table. Researchers can implement their newly developed routing modules by simply configuring and modifying the interfaces.

[0030] Step 3: Simulation process and result visualization

[0031] The system reads satellite positions, ground station positions, and topological relationships at different time points, imports an Earth model using an open-source JavaScript library, and then uses the location information generated in the above steps and simulation process statistics to draw satellite, ground station nodes, links between nodes, and routing forwarding paths, thereby realizing 3D visualization of the network scene during communication. At the same time, the collected simulation data is processed to visualize the network simulation results in an intuitive way.

[0032] During the visibility calculation process, satellite antenna parameters and ground station antenna parameters can be configured to calculate the maximum visible distance of the satellite.

[0033] In the spatial network routing simulation, multiple optimal links can be used to forward data in parallel, improving network resource utilization, achieving load balancing, and enhancing topology stability to some extent. Based on the required hop count and available bandwidth for different paths, an optimal forwarding path is selected for each target node, and nodes on that path are recorded. When calculating suboptimal forwarding paths, depending on the user-selected multipath routing algorithm type (node-independent multipath, link-independent multipath, and related multipath algorithms), nodes recorded in the local topology are temporarily removed to improve the independence of the calculated paths and the reliability of the routing algorithm.

[0034] During the simulation of the network scenario, the simulation tool's modules can be highly integrated with the physical network environment. On one hand, virtual nodes can send and receive data using the physical network; on the other hand, physical nodes can also send and receive data packets using virtual channels constructed by the simulation tool. Support for extended hardware-in-the-loop simulation can further reduce costs.

[0035] Beneficial Effects: This invention provides a lightweight, open, and scalable simulation system for space routing algorithm simulation. It reduces the cost and improves efficiency of experimental verification in the research and development of low-Earth orbit (LEO) satellites. This simulation system is a lightweight, open, and scalable simulation platform that does not rely on satellite toolkits. It can independently calculate inter-satellite and satellite-to-ground visibility relationships, configure planned network topologies as needed, and visualize the simulation process and results so that users can intuitively understand the structure of satellite trajectories and their impact on constellation behavior. Simultaneously, this invention supports static and dynamic space routing algorithm simulations, and can be configured to meet the operating environment and conditions of different types of routing algorithms, basically satisfying the routing simulation needs of space networks. This invention also provides a simulation system with open related interfaces, allowing users to customize relevant modules, scenarios, services, algorithms, node configurations, etc., according to their needs, and to monitor and analyze the network. It provides a pure software simulation tool in the experimental verification phase of LEO satellite research and development, capable of independently calculating inter-satellite and satellite-to-ground visibility relationships, configuring planned network topologies as needed, and visualizing network simulation scenarios, processes, and results. Attached Figure Description

[0036] Figure 1 This is the overall architecture diagram of the present invention.

[0037] Figure 2 This is a simulation flowchart of the present invention.

[0038] Figure 3 This is an example diagram of the input configuration of the present invention.

[0039] Figure 4 This is a flowchart of the visibility determination process of the present invention.

[0040] Figure 5 This is an example of a partial topological connection relationship in this invention.

[0041] Figure 6 This is a topology visualization diagram of the present invention.

[0042] Figure 7 This is an example diagram of the end-to-end round-trip delay of the present invention.

[0043] Figure 8 This is an example diagram showing the throughput of the present invention.

[0044] Figure 9 This is a multi-path visualization diagram of the present invention. Detailed Implementation

[0045] To better understand the technical content of this invention, specific implementation examples are provided below in conjunction with the accompanying drawings.

[0046] Combination Figure 1 As shown, this invention proposes a lightweight software simulation system suitable for research on space routing algorithms. It mainly includes a system configuration module, a simulation model module, a routing simulation module, a file output module, a performance analysis module, a visualization module, and a data management module, involving the implementation of simulation elements at various levels of satellite scenarios and space networks.

[0047] The space communication network software simulation method and system of the present invention automatically generates a topology that meets the characteristics of space networks. Taking the discrete-time simulator ns-3 as an example, the simulation of network scenarios is carried out. During the simulation, the generated data packets are monitored and the simulation results are calculated. The scenarios and results are then displayed in 3D visualization.

[0048] The overall scheme for the space communication network software simulation method and system implementation of the present invention includes the following two steps and is implemented accordingly:

[0049] Step 1: Input specific parameters according to the specific scenario to be verified, construct a simulation scenario including ground station nodes, satellite nodes, and space communication channels, and output the visualization. At the same time, define the satellite visibility relationship, the specified routing algorithm, and the application layer service type.

[0050] Step 2: Build a function to monitor and record data in network simulation. Users can set up monitoring of the required data to analyze the network scenario and algorithm protocol performance in specific scenarios and visualize the final results.

[0051] The following examples illustrate the specific definitions of simulation elements such as nodes, links, and services involved in the technical solution of the simulation platform.

[0052] The nodes mentioned refer to virtual nodes used to simulate satellite nodes and ground stations in the network. The nodes are layered to implement the OSI five-layer model and can load and run different algorithm protocols (e.g., transport layer: TCP, UDP; network layer: Dijkstra, AODV, DSDV, DSR, OLSR, OSPF, multipath routing, etc.).

[0053] The aforementioned link refers to the simulated actual channel link between any nodes when they are connected according to the network topology. Simulation will also be used to calculate and configure the propagation loss and bit error rate of the link.

[0054] The services mentioned refer to various standard applications (such as voice, video, HTTP, SMS, etc.) selected according to simulation requirements, or service models constructed through custom methods. They can also utilize traffic models defined by the service source that conform to a specific distribution, such as normal distribution or exponential distribution. Services support priority settings, allowing for different resource allocation corresponding to different priorities. During simulation, data transmission and reception and information collection are implemented based on the specific service model.

[0055] Combination Figure 1 As shown, the exemplary implementation of the space communication network software simulation method and system of the foregoing embodiments will be described in more detail below. Specifically, the configuration in steps 1 and 2 above is achieved through the following methods:

[0056] 1) Establishing the satellite constellation and ground stations: The specific position of each satellite is determined by inputting the number of orbits, the number of satellites in each orbit, and the orbital inclination using satellite design specifications or actual data. Celestial mechanics models and numerical integration methods are employed to determine the position and velocity changes of the satellites over the simulation time. Simultaneously, the six orbital parameters (semi-major axis, eccentricity, orbital inclination, right ascension of the ascending node, argument of perigee, and true anomaly) are calculated. A two-line orbital report (TLE) file containing all satellite parameters is generated according to the format of the two-line satellite parameters. The ground station uses its latitude and longitude as input, and the position of each ground station in the three-dimensional coordinate system is calculated according to Equation 1 below. The input configuration for running Dijkstra's algorithm in a constellation of 25 orbits with 25 satellites in each orbit is as follows: Figure 3 As shown.

[0057]

[0058] Where (lon,lat) are the latitude and longitude coordinates of the ground station; (X,Y,Z) are the three-dimensional coordinates of the ground station.

[0059] 3) Visibility calculation, combined with Figure 4 As shown, the satellite node creation process realizes the changes in inter-satellite distance and visibility caused by its dynamics. The simulation duration is divided into several time slices as needed. For each time slice, the minimum inter-satellite visible distance is calculated according to Equation 2, the maximum inter-satellite visible distance is calculated according to Equation 3, and the maximum satellite-to-ground visible distance is calculated according to Equation 4. The positions of the satellite and the ground station at each moment are read and the distance between them is calculated to determine whether the inter-satellite and satellite-to-ground distances are within the visible range. Then, the visibility relationship of continuous time is generated according to the time slices.

[0060]

[0061]

[0062]

[0063] Among them, L MinISL R is the shortest visible distance for inter-satellite links; M is the Earth's radius; α is the orbital altitude; L is the satellite elevation angle; MaxISL β is the maximum visible distance of the inter-satellite link; H is the atmospheric altitude; β is the ground station elevation angle; L MaxGSL This represents the maximum visible distance between the satellite and the ground.

[0064] 3) Network topology establishment: Satellite numbers are established based on the number of orbits and the number of satellites within each orbit. Users can perform topology planning to generate the required network topology. Satellites with different numbers construct a network topology table according to the planned constellation configuration. Topologies visible only on a single orbit, multiple orbits, and close proximity are all possible. Communication channels between nodes are determined based on the topology, and free-space propagation loss is calculated using Formula 5 based on the distance between satellites. For example, the grid-like topology constructed in a constellation with 25 orbits and 25 satellites per orbit forms the following topology connection relationships: Figure 5 As shown, its visualization results are as follows: Figure 6 As shown.

[0065] L=20logF+20log D+32.4 (5)

[0066] Where F is the frequency; D is the distance; and L is the propagation loss.

[0067] 4) Combining Figure 2 As shown, in the network scenario simulation, after the dynamic network topology model is established, application layer services are customized according to user needs, including service types and priorities. Simulation begins based on the selected network layer routing protocol. During the simulation, data generated in the network can be monitored and recorded. Subsequent processing and analysis are performed after the simulation is complete. Taking the Dijkstra algorithm running in a constellation of 25 satellites in 25 orbits as an example, the monitored and recorded data is analyzed and processed. The end-to-end latency from Rio de Janeiro to St. Petersburg is as follows: Figure 7 As shown, the throughput from Rio de Janeiro to St. Petersburg is as follows: Figure 8 As shown.

[0068] 5) Visualization of network scenarios: Read satellite positions, ground station positions, and topological relationships at different time points, and use the open-source JavaScript library for 3D earth and map visualization developed by AGI to draw nodes and corresponding links between nodes, thereby realizing 3D visualization of network scenarios and visualizing network simulation results in an intuitive way.

[0069] In a further embodiment, during the visibility calculation process, satellite antenna parameters and ground station antenna parameters can be configured to calculate the maximum visible distance of the satellite.

[0070] In a further embodiment, during the establishment of the network topology, the communication channels between nodes are determined according to the imported topology, and the propagation loss and bit error rate are calculated. The configuration parameters are then imported into ns-3 for physical layer characteristic settings.

[0071] In a further embodiment, during the simulation of the network scenario, the application layer supports multiple standard applications, and supports the implementation of custom business models or traffic models conforming to specific distributions through application module functions or configuration sockets within ns-3, and defines business priorities through traffic-control modules and socket configurations within ns-3.

[0072] In a further embodiment, during the simulation of the network scenario, the data packet format can be customized, including the data header format and the data format. The data header format can be customized by modifying the content of the Internet module in ns-3, and the data packet can be filled with customized data content when generating the data packet.

[0073] In a further embodiment, during the simulation of the network scenario, the supported routing protocols include static routing and dynamic routing, and multi-path routing is possible. The routing algorithm can be configured by configuring the corresponding routing module within ns-3. MAC layer access supports TDMA, and all algorithm protocols can be modified or customized.

[0074] In a further embodiment, during the network scenario simulation, static routing calculates the next-hop path from each satellite to all other satellite nodes using Dijkstra's algorithm and depth-first search based on the established topology. Path selection prioritizes hop count, and in cases of identical hop counts, latency is used as the cost to select the optimal path. Each snapshot yields an initial routing table containing the path from each node to other nodes in the network. During snapshot switching, the routing table within each snapshot is invoked accordingly.

[0075] In a further embodiment, during the simulation of the network scenario, the dynamic routing table is updated by snapshot switching and network topology changes. Snapshot switching is timed and updated according to the snapshot sequence number. The network topology is adjusted based on network state changes, and a dual routing table approach is used to improve routing accuracy and efficiency. Neighbor node state detection is implemented by the HELLO module, which periodically sends and receives messages. Detecting neighbor node state is a communication process between two nodes, requiring a timed response. UDPSOCKET communication is used, with the sleep() function setting the sending interval and the setsocket() function setting the timer. If the client does not receive an acknowledgment message from the neighbor server within the send_timeout time, the node is considered disconnected. When node connection or disconnection causes inconsistencies in the network state, changes in the neighbor table trigger a topology change, followed by route recalculation.

[0076] In a further embodiment, during the simulation of the network scenario, multi-path routing can be configured with routing selection methods and packet scheduling methods.

[0077] In a further embodiment, during the simulation of the network scenario, multipath routing selects the optimal forwarding path for each target node based on the required number of hops and the available bandwidth of different paths, and records the nodes on the optimal path; when calculating the suboptimal forwarding path, nodes recorded from the local topology are temporarily deleted according to the multipath routing algorithm type selected by the user: node-independent multipath, link-independent multipath, and related multipath algorithms, in order to improve the independence of the calculated different paths and the reliability of the routing algorithm. Figure 9 A visualization example of the multipath from New York to Beijing at a certain moment for a constellation of 25 satellites in 25 orbits.

[0078] In a further embodiment, during the simulation of the network scenario, the tap-bridge-network-device module within ns-3 can be highly integrated with the physical network environment. On one hand, virtual nodes in ns-3 can use the physical network to send and receive data; on the other hand, physical nodes can also use the virtual channels constructed by ns-3 to send and receive data packets. This supports hardware-in-the-loop simulation, further reducing costs.

[0079] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention is defined by the claims.

Claims

1. A lightweight software simulation system suitable for spatial routing algorithm research, characterized in that, The system comprises a system configuration module, a simulation model module, a routing simulation module, a file output module, a performance analysis module, a visualization module, and a data management module. Specifically: the system configuration module is used to input various initial parameters, including the simulation scenario, communication capabilities, algorithm protocols, and communication services; the simulation model module is used for link calculation and constellation topology construction; the routing simulation module is used for route calculation, updating and maintaining routing tables, and performing route forwarding; the file output module is used to record the raw files containing the required results; the performance analysis module is used to statistically analyze performance metrics during the simulation process; the visualization module is used to display the node and system operating status and results; and the data management module is used to store the data generated during the simulation. The specific configuration can be achieved through the following steps: Step 1: Parameter Configuration and Constellation Construction 1) The establishment of satellite constellation and ground stations involves determining the specific position of each satellite by inputting the number of orbits in the constellation, the number of satellites in each orbit, and the orbital inclination through satellite design specifications or actual data. Celestial mechanics models and numerical integration methods are used to determine the position and velocity changes of the satellites during the simulation time. At the same time, the six orbital elements of the satellites are calculated, including the semi-major axis, eccentricity, orbital inclination, right ascension of the ascending node, argument of perigee, and true anomaly. This generates a two-line element orbital report TLE file containing the satellites. The ground stations are input with their latitude and longitude to calculate the position of each ground station in the three-dimensional coordinate system. 2) Visibility calculation: During the creation of satellite nodes, the changes in inter-satellite distance and visibility caused by the dynamic nature of satellites have been realized. The simulation duration is divided into several time slices as needed. For each time slice, the visible distance range of inter-satellite links and satellite-to-ground links is calculated to determine whether satellites and ground stations are within the visible range at the current moment. Then, the visibility relationship of continuous time is generated based on all time slices to replace the link communication time calculation of the satellite toolkit. （1） （2） （3） in, This represents the shortest visible distance for inter-satellite links. The radius of the Earth; The orbital height; This refers to the satellite's elevation angle; This represents the maximum visible distance of the inter-satellite link. Atmospheric altitude; The elevation angle of the ground station; This represents the maximum visible distance between the satellite and the ground. 3) Network topology construction: Each satellite in the constellation is assigned a number according to its orbit and its relative position in the orbit. Users perform topology planning to generate the required network topology. Satellites with different numbers construct network topologies according to the planned constellation configuration, constructing single-track visible topologies, multi-track visible topologies, and topologies visible when close. 4) Network scenario simulation: After the network dynamic topology model is established, application layer services can be customized according to requirements, and the routing protocol to be tested in the network layer or the routing algorithm to be configured can be selected to start the simulation. During the simulation, the data generated in the network can be monitored and recorded, and subsequent processing and analysis can be performed after the simulation is completed. 5) Visualization of network scenarios: Read satellite positions, ground station positions and topology at different time points, import the Earth model using an open-source JavaScript library, and draw satellite, ground station nodes, links between nodes and routing forwarding paths based on the position information generated in the above steps and the statistical information of the simulation process. This achieves 3D visualization of the network scenario during communication. At the same time, the simulation data monitored and recorded during the simulation process is processed to visualize the network simulation results in an intuitive way. Step 2: Spatial Network Routing Simulation In low-Earth orbit satellite networks, satellite nodes move periodically, and the topology changes constantly, but it is also predictable. Routing algorithms are divided into two main categories according to the routing table update mechanism: static routing algorithms do not consider changes in network topology and divide the satellite network in time and space; dynamic routing algorithms calculate and update the routing table in real time based on information transmission in the network, and flexibly adapt to changes in network topology and load. For different types of routing algorithm implementation mechanisms, corresponding modules are provided to meet the running conditions of static and dynamic network topology routing algorithms. Users can configure the routing module of the simulation platform into their own developed routing module according to the specific implementation details of the routing algorithm to be simulated, and build the required simulation environment. Configurable parameters are supported, which users can adjust according to different network requirements. The simulation platform provides a static network topology routing module responsible for calculating the next-hop path from each satellite to all other satellite nodes, prioritizing path selection based on hop count, and choosing the optimal path based on latency when hop counts are the same; a routing table management module responsible for managing and updating the routing table of each node, recalculating the routing path when the network topology changes, and broadcasting the updated routing table to the entire network to ensure consistency of routing tables across all nodes; and defining and implementing interfaces between modules, including input / output interfaces and data format definitions, to enable interaction and data transmission between modules. The simulation platform provides a dynamic network topology routing module that enables each node to periodically send HELLO probe messages to probe the connection status of neighboring nodes. When the current state in the neighbor table differs from the previous state, the network topology is modified, and the route is recalculated based on the topology update. To prevent loops, a broadcast mechanism is added. When the previous and current states in the neighbor table are found to be inconsistent and the routing table needs to be updated, this change in link information is broadcast to the entire network to inform other nodes to update the topology synchronously and recalculate the routing path. The system provides interfaces for interaction between various modules: First, the routing algorithm module calls the network topology interface to obtain network topology information; this interface provides basic information about the network topology, helping the routing algorithm module calculate the optimal routing path; second, the routing algorithm module updates the routing table through the routing table management interface. The routing table management module is responsible for maintaining and updating the routing table, updating it based on information provided by the network topology interface. It also calculates routing paths based on information provided by the routing algorithm interface. Finally, the routing algorithm module sends the updated routing table to the entire network via the network broadcast interface, which broadcasts the routing table information throughout the network. Simultaneously, the routing algorithm module uses this interface to obtain routing table information sent by other nodes and update its local routing table accordingly.

2. The lightweight software simulation system for spatial routing algorithm research according to claim 1, characterized in that, During the visibility calculation process, the satellite antenna parameters and ground station antenna parameters are configured to obtain a matching visible distance range.

3. A lightweight software simulation system suitable for spatial routing algorithm research according to claim 1, characterized in that, During the construction of the network topology, the communication channels between nodes are determined based on the imported topology, and the propagation loss and bit error rate are calculated. The configuration parameters are then imported into the network simulation tool to set the physical layer characteristics.

4. A lightweight software simulation system suitable for spatial routing algorithm research according to claim 1, characterized in that, During the network scenario simulation, the application layer supports multiple standard applications and allows for the implementation of custom business models or traffic models conforming to specific distributions through application module functions or configuration sockets within the network simulation tool. Service priorities can be defined through the traffic control module and socket configuration within the network simulation tool.

5. A lightweight software simulation system suitable for spatial routing algorithm research according to claim 1, characterized in that, During the simulation of the network scenario, static routing and dynamic routing protocols are supported. The routing algorithm is efficient and scalable. By configuring the corresponding routing module in the network simulation tool to simulate custom routing algorithms, the needs of large-scale network simulation can be effectively met.

6. A lightweight software simulation system suitable for spatial routing algorithm research according to claim 1, characterized in that, During the simulation of the network scenario, the MAC access layer protocol supports TDMA, and all algorithm protocols support modification and customization.

7. A lightweight software simulation system suitable for spatial routing algorithm research according to claim 1, characterized in that, During the simulation of the network scenario, multi-path routing that supports custom routing methods and packet distribution methods improves the reliability and fault tolerance of the network.

8. A lightweight software simulation system suitable for spatial routing algorithm research according to claim 1, characterized in that, In the spatial network routing simulation process, multiple optimal links are used to forward data in parallel to improve the utilization of network resources and achieve load balancing. Based on the required number of hops and the available bandwidth of different paths, the optimal forwarding path is selected for each target node, and the nodes on the optimal path are recorded. When calculating the suboptimal forwarding path, according to the multi-path routing algorithm type selected by the user: node-independent multi-path, link-independent multi-path, and related multi-path algorithm, nodes recorded from the local topology are temporarily deleted to improve the independence of the calculated different paths and the reliability of the routing algorithm.

9. A lightweight software simulation system suitable for spatial routing algorithm research according to claim 1, characterized in that, Virtual nodes use physical networks to send and receive data; physical nodes use virtual channels built with simulation tools to send and receive data packets.

10. A lightweight software simulation system suitable for spatial routing algorithm research according to claim 1, characterized in that, In step one, 1) the establishment of the satellite constellation and ground stations involves determining the specific position of each satellite by inputting the number of orbits in the constellation, the number of satellites in each orbit, and the orbital inclination using satellite design specifications or actual data. Celestial mechanics models and numerical integration methods are used to determine the position and velocity changes of the satellites during the simulation time. Simultaneously, the six orbital parameters of the satellites are calculated: semi-major axis, eccentricity, orbital inclination, right ascension of the ascending node, argument of perigee, and true anomaly. A two-line orbital report (TLE) file containing all satellite parameters is generated according to the format of the two-line satellite parameters. The ground stations use their latitude and longitude as input, and the position of each ground station in the three-dimensional coordinate system is calculated according to the following formula (4). （4） in, The coordinates of the ground station are latitude and longitude. The three-dimensional coordinates of the ground station; 2) Visibility calculation: During satellite node creation, the changes in inter-satellite distances and visibility caused by their dynamics are implemented. The simulation duration is divided into several time slices as needed. For each time slice, the minimum inter-satellite visible distance is calculated according to Equation 5, the maximum inter-satellite visible distance according to Equation 6, and the maximum satellite-to-ground visible distance according to Equation 7. The positions of the satellite and the ground station at each moment are read and the distance between them is calculated to determine whether the inter-satellite and satellite-to-ground distances are within the visible range. Then, the visibility relationship for continuous time is generated based on the time slices. （5） （6） （7） in, This represents the shortest visible distance for inter-satellite links. The radius of the Earth; The orbital height; This refers to the satellite's elevation angle; This represents the maximum visible distance of the inter-satellite link. Atmospheric altitude; The elevation angle of the ground station; This represents the maximum visible distance between the satellite and the ground. 3) Establishment of network topology: Satellite numbers are established according to the number of orbits and the number of satellites in the orbits. Users perform topology planning to generate the required network topology. Satellites with different numbers construct a network topology table according to the planned constellation configuration. It is possible to construct a topology that is visible on a single orbit, a topology that is visible on multiple orbits, and a topology that is visible when the distance is close. Based on the topology, the communication channel between nodes is determined, and the free space propagation loss is realized according to Equation 8 based on the distance between satellites. （8） in, For frequency; For distance; For propagation loss.

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