A Joint Rate and FEC Adaptation Approach to Enable High Speed Broadcast in IEEE 802.11 Networks

Rate adaptation is a MAC-layer mechanism in IEEE 802.11 networks to ensure efficient utilization of constantly varying wireless channel. However, for broadcast communication, most commodity wireless drivers only support the base rates (i.e., 1 or 2 Mbps in 802.11b/b+g and 6Mbps in 802.11a/g), leaving the channel capacity significantly underutilized. In this paper, we present a novel rate adaptation framework designed for wireless broadcast to improve the 802.11 network performance. This framework jointly selects the data rate and the error protection level at the same time. It has been also designed in a manner that it does not require changes to legacy applications or to the 802.11 standards (thus can work in existing 802.11 networks). Using the performance measurement study in live networking environments, we show that the proposed scheme provides substantial improvement in performance while providing low application level loss, and can adapt to different operational environments.