基于线性均方误差的无线自组网TCP定时器改进

Improving TCP timer in wireless ad hoc networks based on linear mean squares

对无线自组网TCP数据流重传定时器(RTO)与传输回路时间(RTT)的关系进行仿真和分析;指出在RTT剧烈振荡的无线多跳网络环境下RTO值(TRTO)的变化会滞后于RTT值(TRTT)的变化,导致TRTO估计不准确;利用线性均方(LMS)误差估计理论改进TRTO的估计算法。实验结果表明:基于LMS的TRTO估计算法能准确的估计TCP数据传输的TRTT,减少TCP数据传输中的伪重传,提升无线环境下TCP协议的数据吞吐量。

The relationship between retransmission time-out（RTO） and round-trip time（RTT） of TCP data flow in wireless ad hoc networks was simulated and analyzed,then the RFC 2988 RTO estimated value was not accurate as the change of RTO value（TRTO） was late to catch up the change of RTT value（TRTT） over wireless ad hoc networks.The RTO estimated algorithm was improved by using linear mean square（LMS） theory.Simulation results show that the LMS RTO algorithm can estimate RTT accurately,so the TCP data flow based on LMS timer can reduce the TCP spurious retransmission,and then promote the TCP data throughput in wireless ad hoc networks.