Delay-dependent robust anti-windup synthesis approach to AQM in TCP/IP networks

An anti-windup compensator for input saturating systems with input and state delays is applied to active queue management (AQM) of a congested TCP/IP router. A TCP model with link capacity disturbances, modeling uncertainties and time-varying delay is investigated, and the objective is to design a controller which is capable of achieving the queue size and can guarantee robust stability in the presence of disturbance and model perturbations. Numerical example is given to demonstrate the effectiveness of the proposed method in comparison with other conventional methods.