摘要： TCP-Westwood (TCPW) 是针对无线网络误码率高的特点而设计的。它能在大误码率情况下取得较好的性能，但它丢包较多、在长延时环境中性能下降较快，这使得它不能直接在卫星网中使用。该文针对卫星网特点，提出一种TCPW的改进方案：每次带宽估计计算后确定当前拥塞窗口是否适宜，一旦当前窗口大于估计带宽，就迅速降低窗口。仿真实验证明，这种改进方案不仅提高了TCPW的吞吐量，而且使丢包数大幅度下降。

关键词: 拥塞控制, TCP, 卫星网

Abstract: TCP-Westwood (TCPW) is shown to provide significant performance improvement in the case of high BER. But its performance gain is achieved on the base of packet losses and its throughput decreases with RTT growing. An improved scheme TCPW-S is proposed in this paper to make TCPW more suitable for satellite network with scarce resource and long delay. After every RTT, congestion window is adjusted to the estimated bandwidth with a conservative policy. Simulation results reveal that throughput of TCPW-S increases while packet losses drop a lot.

Key words: Congestion control, TCP, Satellite networks