Robust Stability Criteria for TCP/AQM Networks with Time-Varying Delay

This paper proposes a robust stability analysis method for TCP/ AQM networks based on a time-varying structured uncertainties and time-varying delays control theory. Some delay-dependent stability criteria under which TCP/AQM system is global stability in terms of the error between instantaneous queue lengths and target queue length are devised. Since free weighting matrices are used to express the relationship between the terms in the Leibniz-Newton and appropriate ones are selected by means of linear matrix inequalities, the criteria is less conservative than existing ones. Numerical example demonstrates that this analytic method is effective.