Robust H∞ congestion avoidance in differentiated services communication networks

Network congestion control remains a critical and high priority issue. The rapid growth of the Internet, the massive amount of data traffic it carries and increased demand to use the Internet for time-sensitive voice and video applications necessitates the design and utilization of effective congestion control algorithms. The reliance of the Internet on the TCP/IP protocol suite suggests that we must focus our efforts in this area. Existing TCP/IP protocol suite has been designed for best effort (delay tolerant) services and cannot effectively support time sensitive applications. We will use the integrated dynamic congestion control (IDCC) scheme. The problem that comes up is the lack of an effective way of dealing with congestion. On the other hand, the IDCC scheme controls the traffic using information on the status of each queue in the network. It is based on a nonlinear model of the network that is generated using fluid flow considerations. The aim of this paper is to design a robust active queue management system to secure high utilization, bounded delay and loss, while the network complies with the demands each traffic class sets. To this end, we will use the H, control theory. Simulation results of the proposed control action demonstrate the effectiveness of the controller in providing robust queue management system.