The Research Of Network Congestion Algorithm Based On Link Feedback Under High Speed Mobility

With the rapid development of high-speed railway,high-speed mobile communication network becomes one of the important directions of high-speed railway information construction.High-speed mobile communication network is mainly divided into railway netvwork and user open network.According to specific user open high-speed mobile communications network as the research background,and combined with the latest development and research of the high speed network congestion control algorithm,this paper optimized and improved the network congestion control algorithm,and proposed a new high-speed congestion control algorithm to improve the quality of network service.Algorithm performance analysis and simulation results show that it can improve network performance and service quality under the high-speed railway specific scenarios.The main work of this paper is summarized as follows:(1)This paper proposed a new adaptive congestion control algorithm based on the nonlinear packet loss rate,named GTRED algorithm.It can solve the problem of TRED algorithm that its queue length shock is too large.The packet loss probability of GTRED algorithm is calculated by using the cubic function in a segmented way,and extended the average queue length to 2 times of the maximum threshold.On the basis of expanding the scope of the algorithm,the stability of the queue length in the dynamic network environment is realized.The experimental simulation results demonstrated that the algorithm can solve the problem of the queue length shock is too large,and also can effectively achieve a trade-off in the delay and the throughput between high and low flow load.This algorithm not only has better robustness and stability,but also effectively improved the network performance.(2)A network congestion control algorithm based on link feedback is proposed,named Pre-HSTCP algorithm.Through further research of the high speed network congestion algorithm,for example,HSTCP algorithm,Fast-TCP algorithm,STCP algorithm and so on.Based on the detailed analysis of the specific research background of the high-speed railway,then the conclusion is drawn that the packet loss rate on the fixed route has certain regularity.So making the rule of packet loss on fixed route as one of the conditions to judge network congestion,to improved and optimized the high-speed congestion control algorithm.The performance of user open mobile communications network under high-speed railway environment is further improved.(3)The experimental simulation of the Pre-HSTCP algorithm is carried out through NS experimental platform.The performance advantage of the algorithm is fully verified by the simulation results.Through adjusting the window size in advance,the algorithm can effectively reduce packet loss rate,and improve the link utilization rate.What?s more,the algorithm also can make the high speed railway communication network have stable data flow and higher network throughput.