V2G网络中基于带宽自适应的拥塞控制协议优化

Optimization of congestion control protocol based on bandwidth adaptive in V2G network

V2G网络下PLC链路带宽受限、高误码率等特点导致现有的TCP NewReno拥塞控制机制缺乏对丢包类型的有效判断,将链路上由噪声干扰的随机错误丢包与网络拥塞丢包统一当做拥塞事件处理,从而造成不必要的拥塞避免,导致了低吞吐量问题。根据此问题,提出了一种基于带宽自适应的拥塞控制算法。该算法通过分组预测拥塞等级感知网络状态,由此估计可用带宽来判断丢包类型,实现了拥塞窗口自适应调节。仿真结果表明该算法在拥塞窗口的增长、吞吐量、公平性、收敛性和友好性等方面都优于现有算法,V2G网络的吞吐量得到明显提升。

Due to the limited bandwidth and high bit error rate of V2G network,the traditional TCP NewReno algorithm is incompetent of estimating the type of packet loss,and treats random error packet loss caused by noise interference and network congestion packet loss as congestion events,which leads to the dilemma of unnecessary congestion avoidance and low throughput.To this end,this paper proposed a new method to address the bandwidth adaptation problem.Contrast to the traditional method,it established a group prediction based model to predict the current network state,which could be utilized to estimate the available bandwidth for determining the type of packet loss,and achieved the adaptive adjustment of congestion window.Simulation experiments show that the proposed algorithm is better than TCP NewReno algorithm in terms of congestion window,throughput,fairness,convergence and friendliness,which significantly improves V2G network throughput performance.