A robust discrete-time controller for delay sensitive applications

Real time network applications require effective mechanisms for managing Internet traffic in order to avoid or at least limit the level of congestion. We propose, design and analyze an Active Queue Manager (AQM) for controlling jitter using robust control theory. We used an output feedback controller and this controller is based on discrete-time model of TCP. The natural properties of robust controller help us for decreasing effect of model uncertainty and undesirable flows on performance of traffic control. The proposed Robust Discrete-Time Controller (RDTC) can guarantee the queue length in router to desired value quickly. We used ns2 for simulation of controller performance and the simulation results certify the validity of the algorithm.