Robust MAC-layer rate control mechanism for 802.11 wireless networks

Abstract

Node mobility, signal fading and interference introduce dynamics in wireless channels. In 802.11 wireless networks, there are several transmission rates that can be adaptively selected by the MAC-layer rate control mechanisms to cater for various channel conditions. Accurately estimating the current channel conditions and successfully selecting the appropriate rates at the right time is critical to ensure the network's optimal performance. In this paper we focus on the problem of rate selection and present a robust, yet practical, rate control mechanism-RCELC, which measures the throughput achieved by each rate, and it selects a rate that achieve the highest throughput for the current channel conditions. To ensure its robustness RCELC optimises rate sampling and also guarantees achieving the highest throughput even in the cases of collisions. RCELC is a practical rate control mechanism that we have developed and evaluated on new mac80211 framework in Linux. We use a set of comprehensive evaluation scenarios and show that RCELC achieves superior performance and substantially outperforms the best rate control mechanism currently available in Linux.