Contact Graph Segmentation Routing Based On Link Error Rate Prediction In Satellite Internet Scenarios

With the improvement of satellite processing capabilities,the maturity of laser communication technology and the reduction of satellite launch costs,the development of satellite Internet have made great progress.Satellite Internet uses technologies such as communication,computing and navigation to build a global network of low-orbit satellite constellations.It builds a space network information exchange infrastructure to achieve seamless global coverage of mobile communication services.This has played an important role in China's new infrastructure strategy.The inter-satellite link has the characteristics of long delay,high bit error and intermittent interruption,which are important factors that restrict the performance of satellite Internet networks.Although the Delay Tolerant Network(DTN)based on the Contact Graph Routing(CGR)can solve the problem of satellite links to a certain extent,the explosive growth of the number of satellites in the satellite Internet has brought severe challenges to the CGR,such as the update of the contact plan,routing calculations and Data packet forwarding,so this paper takes the adaptive improvement of the CGR algorithm in the satellite Internet scenario as the research focus.The CGR algorithm lacks a satellite link failure detection mechanism,and cannot respond to sudden contact failures in a timely manner,resulting in a decrease in the accuracy of the contact plan,making the transmission path include a failure path,and reducing the success rate of data packet delivery.In order to improve the accuracy of contact planning,this paper proposes a Dynamic Contact Graph Routing based on Contact Failure Detection(DCGR-CFD).The algorithm relies on the self-update strategy of the static contact plan based on the inter-satellite visibility analysis to realize the periodic self-update of the contact plan in the satellite node,get rid of the dependence of the contact plan update process on the ground station,and save the time cost of the contact plan update.The DCGR-CFD algorithm also uses a contact failure response algorithm for millisecond-level contact failure detection to eliminate failed contacts and ensure the accuracy of the contact plan.This article uses Satellite Tool Kits(STK)and Optimized Network Engineering Tool(OPNET)to build a communication model based on DTN,and compares the transmission performance of the DCGR-CFD,the Contact Graph Routing based on Hello Message Detection(CGR-HMD)and the CGR.The simulation results show that compared with other algorithms,the DCGR-CFD in the same simulation environment can achieve a higher delivery success rate and lower transmission delay.According to the difference in the channel environment between the satellite-ground link and the inter-satellite link,this paper proposes the Contact Graph Segmentation Routing based on Link Reliability(CGSR-LR),which combines CGR The routing calculation process of the algorithm is divided into two parts: the satellite-to-ground link and the inter-satellite link.For satellite-to-earth links with poor channel quality,this paper proposes a Contact Graph Routing based on Link Bit Error Rate Prediction(CGR-BERP),which uses OPNET and MATLAB co-simulation to build a long-and short-term memory(LSTM)network inter-satellite link bit error rate prediction model,and select the appropriate forwarding path according to the channel quality of the satellite-to-earth link to solve the stability problem of the communication system under severe weather conditions.For inter-satellite links with better channel quality,this paper proposes a hybrid contact graph routing based on the delivery success rate(HCGR-DSR).On the basis of the contact graph routing algorithm based on the shortest path,the algorithm introduces label forwarding technology to establish a backup path for the part of the path with a lower delivery success rate to improve the delivery success rate of data packets.The simulation experiment results show that compared with the contact graph routing based on the shortest path(CGR-SP)and the contact graph routing based on the delivery success rate(CGR-DSR),the CGSR-LR can still maintain a high data packet delivery success rate under rainy and cloudy weather conditions,and has strong anti-interference ability.