This research presents an investigation into designing active queue management (AQM) controllers in the bottleneck gateway router using control theory. The main goals of this design are to increase the speed of response, improve stability and robustness of congestion control system. In this study a new design scheme is presented by augmenting a Smith Predictor (SP) to the standard RED controller. The new controller is named as SPRED. Smith predictor structure is incorporated to compensate the time delay of the system. Using Smith predictor the new controller is tuned to remove...