A Multi-Resolution Wavelet PID Controller for Internet AQM Routers

Internet represents a shared resource wherein users contend for the finite network bandwidth. Contention among independent user demands can result in congestion, which in turn leads to long queuing delays, packet losses or both. Congestion control regulates the rate at which traffic sources inject packets into a network to ensure high bandwidth utilization while avoiding network congestion. This paper presents a new Active Queue Management algorithm in internet routers using a hybridization of multiresolution wavelet with the classical PID control (MR. Wavelet PID). The aim is to control the router queue length within a desired threshold queue level for a linearized TCP congestion model. The analytical results for a linearized TCP/AQM model are simulated using MATLAB. The performance of the proposed control scheme is evaluated for various network scenarios and the obtained results show the capability of the proposed controller to compensate for a wide range of TCP flows and link capacity variations.