Date Added: Dec 2009
Rate adaptation is a critical component that impacts the performance of IEEE 802.11 wireless networks. In congested networks, traditional rate adaptation algorithms have been shown to choose lower data-rates for packet transmissions, leading to reduced total network throughput and capacity. A primary reason for this behavior is the lack of real-time congestion measurement techniques that can assist in the identification of congestion related packet losses in a wireless network. In this paper, the authors first propose two real-time congestion measurement techniques, namely an active probe-based method called channel access delay, and a passive method called channel busy time.