Discrete-time flow control for connection-oriented communication network via reduced model

In this paper, a suboptimal flow controller design for connection-oriented communication network via reduced model is proposed. Network is modeled as an nth order discrete system whose available bandwidth variations at the bottlenecked link act as an exogenous unmatched disturbance. The proposed scheme is characterized by a simple first order design which is applied to nth order systems through aggregation. Effect of bandwidth variation at the congested node which is modeled as a disturbance, is well accounted in controller design with widely adopted delay-based disturbance estimation. Performance of the proposed scheme is validated through Matlab and ns simulations. Simulation results shows that all the proposed reduced order control scheme tracks the desired queue length effectively under the adverse influence of unmatched disturbances.