Research On Efficient And Secure Networking In LEO Satellite Networks

With the rapid development of space information technology,LEO satellite network plays an increasingly important role in global communications,navigation and positioning,meteorological prediction,disaster monitoring and military applications.Unlike the ground network,which is restricted by geographical conditions,natural disasters and other factors,the characteristics of LEO satellite network global seamless communication will be the next generation of Internet anywhere and anytime in the world.Communication capability plays a fundamental role,so the efficient and safe networking of LEO satellite network plays an important role.However,the traditional dynamic routing protocol adopts the scheme of disconnection and reconnection in the process of link handover.On the one hand,this scheme will increase the routing signaling in the network and cause network congestion.On the other hand,the delay of path handover is large,which makes the data packet unable to continue sending during the time of path handover,and greatly reduces the network utilization rate;on the other hand,because of satellite.The network has an open characteristic.Compared with the traditional terrestrial network,the routing process and data transmission process of the network have more obvious security risks,such as being more vulnerable to attacks by malicious nodes and causing network anomalies.Based on the above problems,this paper mainly studies the efficient and safe networking of LEO satellite networks.The specific research results and contributions are summarized as follows?Aiming at the problem of large delay in path switching,a parallel routing protocol based on topology detection and data forwarding is proposed.This protocol is based on the traditional on-demand routing protocol and improves its link switching part.The active detection mechanism of topology based on link state prediction is adopted to break the traditional mode of link disconnection and reconnection.According to the periodicity and regularity of the orbit,the prediction section is predicted.The trajectory of a point can be switched in advance before the link is completely broken,and the rerouting process can be completed to ensure the continuous availability of the path.A simulation platform for LEO satellite networking is built based on NS3,and the proposed routing protocol is implemented.The performance of the system is verified by Iridium-like polar orbit simulation scenario.The system-level simulation platform consists of 60 LEO satellite nodes with six orbits,10 satellites in each orbit,and two typical link characteristics of polar orbits,reverse slit and polar chain breaking,are set up.The simulation results show that the proposed routing protocol can significantly improve the packet loss rate and throughput compared with traditional protocols.In view of the network anomaly caused by malicious node attacks,this paper proposes an inter-satellite adaptive monitoring and authentication technology suitable for LEO satellite networks,which requires each satellite node in the network to actively conduct routing and data transmission to its neighbors.Real-time monitoring of transport behavior,and analysis of its behavior pattern through neural network,find the neighbor nodes with security risks and initiate security authentication.At the same time,a sliding window mechanism based on the principle of complex network centrality is designed to reduce the computational load of nodes while ensuring the security performance.The security module is added to the LEO satellite system-level simulation platform to verify the accuracy of neural network detection,and the optimal solution of sliding window size is calculated.The simulation results show that the proposed inter-satellite monitoring and adaptive authentication technology can effectively improve network throughput and network defense capability under the attack of malicious nodes.