A robust adaptive congestion control for communication networks with time-varying delays

This work presents a congestion control for high-speed networks in the single bottle-neck case with time-varying multiple delays, aimed at avoiding congestion by setting the rates of the traffic flows. The novelty of this paper is that the controller explicitly deals with saturated (i.e., non persistent) sources. The controller consists in a main controller based on classical control theory coupled with a controller based on fuzzy logic: the former works properly when the sources are not saturated; the latter provides a saturation compensation by setting an adaptive multiplicative gain which acts on the rate command. The scheme provides also robust stability to time-delay uncertainties. Simulations prove its effectiveness.