Stability analysis of the PRDR algorithm: A new congestion control scheme for wireless networks

This paper investigates the congestion control issue in the Internet, especially in wireless environments, and proposes a new congestion control scheme, called Proportional and Derivative (PRDR). Based on the Active Queue Management (AQM) principle, the designed PRDR controller embedded to the router monitors the level of network congestion through the occupancy of the buffer which is maintained within a prefixed control target. Being based on the difference between them, the PRDR controller associated with each link computes periodically at time a fair rate and forwards the result to the next gateways till the destination. Using a feedback scheme, a destination supplies the source with the minimal received. In their turn, sources have to adapt their transmission rate according to received fair rate. Borrowing its modelling from automatic control theory, the design of stability and stabilization conditions of the PRDR algorithm are studied in depth. All theoretical results are tested through simulations under the network simulator ns-2 in a wireless environment.