Design of AQM in Supporting TCP Based on the Well-Known AIMD Model

Abstract

In this paper, we investigate how to design AQM with a low-pass filter (average queuing) in supporting TCP based on the well-known AIMD dynamic model. Since we formulate the AQM design problem for the given TCP as state-space models, we get three important features. First, we derive PD-type (Proportional-Derivative) AQM structure with a low-pass filter which includes P-type (Proportional) RED in terms of queue length. Second, we compensate for delays in congestion measure explicitly by adding a memory control structure that uses the previous dynamic information. Third, we obtain a stabilizing optimal gains of the proposed AQM structure by minimizing a linear quadratic cost of the transients on queue length, aggregate rate, and congestion measure. Finally, we illustrate the above theoretical results through \emph{ns} simulations for TCP Reno.