Robust Active Queue Management for Wireless Networks
Kanchan Chavan, Ram G. Kumar, Madhu N. Belur, Abhay Karandikar · IEEE Transactions on Control Systems Technology · 2010
Active Queue Management (AQM) algorithms have been extensively studied in the literature in the context of wired networks. In this paper, we study AQM for wireless networks. Unlike a wired link, which is assumed to have a fixed capacity, a wireless link has a capacity that is time-varying due to fading. Thus, the controller is required to meet performance objectives in the presence of these capacity variations. We propose a robust controller design that maintains the queue length close to an operating point. We treat capacity variations as an external disturbance and design a robust controller usingH∞control techniques. We also consider the effect of round-trip time in our model. Our method of incorporating the delay into the discretized model simplifies controller design by allowing direct use of systematic controller design methods and/or design packages. We demonstrate the robustness of the controller to changes in the load condition and in the round-trip time throughns-2 simulations.