Research On Inter-Satellite Routing Algorithm For Multi-Layer Satellite Communication System

With the development of communication technology and multimedia technology,the influence of satellite communication in the military and civilian fields has become pyramidally prominent.People’s demand for various aspects of service have raised day by day,and stricter demand have been proposed for the comprehensive service quality of communication systems.Integrating satellite ground networks and achieving global coverage through integrated architecture cooperation can help expand the scope of communication services,enhance transmission performance,and improve resource efficiency.However,multi-layer satellite networks possess frequent dynamic mutations character in network topology,unstable inter satellite link connections,and different services require different network transmission requirements.Low latency services require real-time communication and best effort network transmission,while reliable services require low transmission latency and need to ensure reliable transmission.In particular,satellite networks have limited onboard computing resources.Choosing routing paths based on the characteristics of various services can specifically achieve network load balancing and improve the utilization of network resources.This thesis researches into routing schemes for quality of service in satellite networks in the context of multi-layer satellite networks.This thesis analyzes the background and research importance of recent inter satellite routing,summarizes the current research status of satellite network routing protocols in Chinese and Western,and generalizes the features and defects of actual routing protocols.In the case of multilayer satellite network architecture,software defined network is introduced to the network,treating the high-level satellite network as a control plane,conducting global monitoring of network topology,and calculating routing paths.The underlying satellite network only performs data forwarding to reduce network overhead,and combines virtual topology and virtual node algorithms to analyze the network topology architecture of different time slots to achieve hierarchical network management.Firstly,towards the link congestion problem between satellite nodes,an inter-satellite routing algorithm on account of link threshold values is designed.This algorithm defines the software defined satellite network structure based on GEO/LEO.When routing and forwarding,it considers the link quality of the inter satellite link,comprehensively considers the residual bandwidth of the inter satellite link,the end-to-end delay of transmission,and the link margin for a weighted description,and selects the next hop node to ensure the communication quality of services in network transmission as much as possible,Achieve network load balancing.Secondly,different routing algorithms are proposed for different types of services to address the quality of service issues in the transmission of multiple services.Firstly,according to the QoS types of services,services are divided into three types:those with high latency requirements,those with high bandwidth requirements,and those with low QoS requirements such as latency and bandwidth.Before routing forwarding,a traffic scheduling algorithm based on game theory is adopted to ensure the fairness of service scheduling.After scheduling services,a low complexity routing strategy based on intra orbit priority forwarding rules is adopted for services with high latency or bandwidth requirements,allowing such services to prioritize the use of network resources during transmission,ensuring QoS requirements for latency and bandwidth.For services with low QoS requirements such as delay and bandwidth,an inter satellite routing strategy based on link state is adopted to ensure the transmission quality of such services as much as possible.Finally,the simulation analyses of the algorithm demonstrates that comparison with conventional routing algorithms,the proposed algorithm reduces end-to-end delay and network congestion rate in satellite networks,improves network throughput,and can achieve reliable communication.