Abstract:

A robust AQM (Active Queue Management)congestion control algorithm (GAS-PI)is proposed on the basis of the gain adaptive Smith predictor and according to the Lyapunov asymptotic stability theorem.This algo-rithm is of simple structure,good robustness and excellent network control performance.Moreover,it overcomes the negative impact on the queue stability caused by the large delay.Simulated results indicate that,by the proposed GAS-PI algorithm ,the overshoot of queue can be effectively decreased,and a higher responsive speed as well as a steadier queue can be obtained,that is,the buffer queue quickly converges to the equilibrium point when the net-work is of HTTP disturbance and great overload change.and the dynamic perform ance of large-delay networks remains in good condition.

Key words: congestion control, Active Queue Management, large delay, gain, Smith predictor