摘要： 针对无线环境下TCP调用拥塞控制算法致使性能下降的问题，提出一种基于带宽估计和显式拥塞通知的无线TCP改进方法。在数据发送端采用带宽估计算法优化拥塞窗口尺寸，与具有显式拥塞通知的路由器配合区分分组丢失性质，利用选择性确认选项，加快单窗口多包丢失时拥塞窗口恢复速度。仿真结果表明，改进后的TCP吞吐量超过TCP_SACK近30%，超过TCP_Reno近52%。

关键词: 传输控制协议, 可用带宽估计, 显式拥塞通知, 择性确认

Abstract: In wireless environment, TCP responds to all losses by invoking congestion control algorithm resulting in degraded end-to-end performance. Aiming at this problem, this paper proposes a method of wireless TCP based on bandwidth estimation and Explicit Congestion Notification(ECN). The data sender adopts available bandwidth estimation algorithm in order to optimize congestion window, and cooperates with the router which is configured with the function of explicit congestion notification to distinguish the characteristics of packet losses. The sender takes advantage of SACK option to speed up recovery of congestion window when multi-packets losses are occurred. Simulation results show that the throughput of modification of TCP outperforms TCP_SACK by 30%, and TCP_Reno by 52%.

Key words: TCP, available bandwidth estimation, Explicit Congestion Notification(ECN), SACK

中图分类号: 

• TP393