Optimal linear quadratic controller based on genetic algorithm for TCP/AQM router

As an effective mechanism acting on the intermediate nodes to support end-to-end congestion control, Active Queue Management (AQM) takes a trade-off between link utilization and delay experienced by data packets. In this paper a linear quadratic optimal controller was designed based on linear control theory for TCP/AQM router. The design specifications, depends on choosing weighting matrices Q and R. One must carry out a trial- and- error process to choose the weighting matrices that can satisfy the design specifications. To overcome this difficulty we employ the Genetic Algorithm (GA) to find the proper weighting matrices. This idea gives a new alternative procedure in time varying feedback control to improve the stability performance. The controller simulation results show the efficiency of the proposed controller.