Proportional-Integral Active Queue Management with an Anti-Windup Compensator
Hyuk Lim, Kyung‐Joon Park, Eun-Chan Park, Chong‐Ho Choi · 2002
In this paper, we apply an anti-windup scheme for improving the performance of a conventional Proportional- Integral (PI) controller for Active Queue Management (AQM) supporting TCP flows. When a PI controller is used for AQM, the windup phenomenon of the integral action can cause per- formance degradation because the packet drop probability is lim- ited between 0 and 1. Therefore we model TCP/AQM as a system with a saturator and apply an anti-windup method to the con- ventional PI AQM scheme. We compare the performance of the proposed controller with the conventional PI controller through ns simulations. The simulation results show that our proposed control scheme outperforms the conventional PI controller when the traffic load is varying, which is always the case in the real network environment.