Robust stabilization of uncertain input delay for Internet congestion control

In this paper, we propose a design of an active-queue-management (AQM) scheme based on delay dependent sliding-mode-control (SMC), which is aimed at robust stabilization of input-delay network system with bounded unknown uncertainties. A sliding surface that is based on a predictor has been designed to minimize the effect of the input delay. An AQM controller is derived to ensure the existence of a sliding mode on the surface. A maximum allowable value for the input delay of the system has been found under the AQM controller, uniformly bounded. Simulation experiments have been carried our and the results demonstrate this scheme can achieve transient and steady-state responses. The results also show that this scheme outperforms the known ones with the traditional either proportional-plus-integral or sliding-mode controls.