| In the era of the rapid development of the Internet,the ground network can no longer support all the daily network needs of people alone,while the satellite network can provide users with data communication capabilities with wider coverage.However,the on-board resources of the satellite network are limited and the global network traffic demand distribution is seriously unbalanced,which can easily lead to the insufficient utilization of satellite network resources.The development of Internet technology has brought large-scale business traffic,and satellite networks are prone to congestion under high load,so that the quality of service(QoS)for users cannot be guaranteed.Based on the GEO/LEO double-layer satellite network,this paper introduces the Software Defined Network(SDN)into the satellite network,and proposes a load balancing routing algorithm.Aiming at the problem that satellite network congestion leads to the degradation of QoS performance in complex application environments,the algorithm classifies services with different QoS requirements in practical applications,and designs three corresponding routing strategies.The algorithm also designs a reasonable flow aggregation processing mechanism.What’s more,the algorithm defines three congestion states of satellite nodes and congestion areas,and designs detour strategies for each type of data flow in the congested area.When a new data flow is detected in the network,the algorithm first classifies the data flow according to QoS requirements,aggregates the data flow of the same category,and then forwards it according to the corresponding routing policy.When the controller detects that there is a data flow in the congested area,it will implement the corresponding detour strategy according to the classification of the data flow.The simulation results show that the algorithm effectively improves the performance indicators such as delay,packet loss rate,and throughput when the satellite network transmits different types of services,realizes the load balancing of services with different QoS requirements in the satellite network,and ensures the satellite network service quality in the application environment.Based on the LEO satellite network,this paper proposes a routing algorithm that can optimize the network delay performance while avoiding congestion,and implement it using an improved ant colony algorithm.Due to the large transmission delay and poor delay stability of the satellite network,and the delay performance is seriously degraded under high load,the algorithm improves the initialization parameters,path cost and pheromone update strategy of the ant colony algorithm to solve the above problems.First,the global potential traffic demand is predicted,and the initialization parameters of the function are optimized based on this,which avoids network congestion to a certain extent;then by improving the path cost and pheromone update strategy,the forwarding path with the best delay performance is selected.The simulation results show that the algorithm effectively optimizes the delay performance of the satellite network,avoids network congestion,and improves the quality of service under high load on the satellite network. |
