改进TCP VEGAS拥塞控制协议及其在无线链路中的应用

针对无线信道的随机丢包和时延抖动提出一种基于TCP VEGAS的改进拥塞控制算法。发送端基于确认包中的ec_位估计前向链路的拥塞概率，发生丢包时如果该拥塞概率没有增加则认为是信道引起的丢包。另外，利用低通滤波器对回程时间（RTT）进行平滑，作为TCP VEGAS拥塞控制的基础。基于NS-2的仿真实验验证了算法的有效性。

Enhanced TCP Vegas Protocol and Its Application in Wireless Networks

An enhanced TCP VEGAS congestion control algorithm is proposed for wireless networks. To identify the packet loss and time-delay jitter caused by the wireless channel, the transmitter estimates the congestion probability based on the ec_bit in the ACK packets. In case of packet loss, the transmitter will not reduce the congestion window if the congestion ility does not increase. At the same time, a low-pass fiher is applied to smooth the RTr, so as to remedy the time-delay jitter, and the tilted RTr is used for standard VEGAS congestion control Simulation results based on NS-2 demonstrate the efficiency of the proposed algorithm.