保证TCP友好流公平性的拥塞控制算法

针对非TCP友好流不遵守拥塞控制协议、易抢占TCP友好流带宽的不公平性,提出一种保证TCP友好流公平性的拥塞控制算法,设计保证TCP友好流传输公平性的AQM控制器。分析非TCP友好流的传输特点,估计出其传输流量的最大值。在设计控制器时将非TCP友好流考虑成等价干扰,并在线估计其传输带宽从而限定其最大带宽。设计控制律时利用不确定项的等价干扰方法,以抵消网络不确定性的影响,具有较好的鲁棒性。仿真结果表明,该算法能有效地保证TCP友好流传输带宽的公平性。

Congestion Control Algorithm Ensuring TCP-friendly Flow Fairness

Taking account of unfairness of the bandwidth, which due to the unfriendly TCP don’t obey to the TCP congestion control protocol, this paper presents a congestion control algorithm ensuring TCP-friendly flow fairness. A new robust discreted sliding mode controller is designed based on the max bound of the non-TCP friendly flow. It analyzes the characteristic of the non-TCP friendly flow, and the max translation value of an TCP-unfairness is estimated. It proposes controller regards the influence of unknown disturbances of non-TCP friendly flow and uncertain parameters as an equivalent disturbance, and estimates the value of the disturbance on line by the mechanism of router time delay, employing the value in designing the control law in order to cancel the slowly varying uncertainties. Simulation results show that the algorithm is highly robust against the disturbance under various networks conditions and outperforms significantly.