无线网络TCPRENO协议饱和吞吐量建模与分析

Modeling and Analyzing the Saturated Throughput of TCP RENO in Wireless Networks

在无线网络环境下对TCP Reno协议饱和吞吐量建模展开研究.发现现有的饱和吞吐量模型未考虑TCP Reno快速恢复状态,因而在计算拥塞窗口值时存在误差;同时,现有模型未考虑TCP协议等待应答超时后的慢启动状态.针对上述分析,本文以产生数据分组丢失的不同标志事件为依据,分析拥塞窗口与丢包概率以及传输往返时间之间的关系,并在TCP Reno饱和吞吐量模型中引入快速恢复状态.仿真结果证明,本文提出的模型可以更加有效地估计拥塞窗口值,从而准确地得出TCP Reno协议的饱和吞吐量.

In this paper, we propose a model to analyze the saturated throughput of TCP Reno in wireless networks. First, we have found that prior work on TCP Reno steady state throughput models ignored fast recovery state, thus leading to the deviation of calculating congestion window. Moreover, prior models did not consider of the slow start state of TCP timeout behavior. We further develop a model which introduces a characterization of fast recovery algorithm for the saturated throughput of TCP Reno based on its loss indications and calculate congestion window values as a function of loss rate and round trip time. Finally, extensive measurements demonstrate that our model is able to estimate congestion window effectively and predict the saturated throughput of TCP Reno.