Research On Routing Algorithm Of Low Orbit Satellite Network

With the increasing demand for communication services,satellite communication has become an important research trend in the field of communication technology.Low Earth Orbit satellites have been the focus of scholars for their wide coverage,flexibility,and geographical constraints.As the key technology of LEO satellite network,inter-satellite routing technology is an important factor to improve the performance of the entire satellite communication system.However,LEO satellite network topology changes frequently,uneven load distribution on the satellite link and node failure prone and difficult to repair,as well as the rapid growth of global business,which poses challenges for satellite routing and load balancing.Therefore,this thesis focuses on load balancing and considering network faults,and deeply studies the inter-satellite routing algorithm of specific LEO satellite networks.In this thesis,the satellite network inter-satellite routing algorithm is selected as the research target.Based on the in-depth analysis of LEO satellite constellation and the existing inter-satellite routing algorithm mechanism,an event trigger based adaptive multipath routing is proposed for space network load balancing and considering network faults.The algorithm is simulated and compared with the existing typical algorithms.The performance of the algorithm is verified by analysis.Firstly,this thesis introduces the key technologies of satellite networks,including satellite constellation and satellite network routing,and deeply analyzes the existing routing algorithms.Secondly,combined with the specific LEO satellite network model,this thesis investigates many factors that need to be considered in the design of inter-satellite routing algorithms.EAMR algorithm is proposed to ensure that the satellite network can cope with the fault while focusing on the equalization ability of the inter-satellite routing algorithm.The EAMR algorithm mainly includes three mechanisms: link information update,multipath routing,and load decision.The link information update detects the neighbor satellite load status and link failure in real time through HELLO monitoring,and spreads the congestion or fault information to the whole network through FAILED flooding,triggering the whole network satellite to update the global optimal route;Multipath routing triggers the satellite to update the multipath routing table through events,simplifying on-board storage,and improving data forwarding performance through on-demand loops;The load decision flexibly selects a path based on the link state for data,and balances the network load in time to cope with network failure.Then,STK and OPNET software are used to implement and simulate the EAMR algorithm to model the network layer,node layer and process layer.Finally,a variety of simulation scenarios are designed.The DSP algorithm,LAOR algorithm,ELB algorithm and EAMR algorithm are simulated.The performance of EAMR algorithm is analyzed by comparing the average delay,packet loss rate and throughput.The simulation results show that compared with other routing algorithms,EAMR algorithm effectively improves the network's balance and invulnerability.The algorithm can simplify the on-board storage to adapt to network load changes and link connection state changes with a tolerable overhead,and obtain lower delay and packet loss rate and larger throughput,which embodies the adaptability and effectiveness of the algorithm to congestion and faults.EAMR algorithm can run stably on a specific LEO satellite network.The algorithm also shows a good adaptability for other polar or near-polar orbital constellations.