A Rapidly Adaptive Collision Backoff Algorithm for Improving the Throughput in WLANs

In the 802.11 protocol, fundamental medium access mechanism is called Distributed Coordination Function (DCF). DCF, before making any transmission attempt, nodes count down a timer with value randomly selected from Contention Window (CW) size. If transmitted packet involved in collision, node increases CW size an attempt to reduce collision rate. Conversely, if successfully, reduces order increase frequency of attempts. The growth or reduction has critical effect on network performance. Several backoff algorithms have been proposed improve system throughput. However, none these methods enable approach theoretical maximum throughput possible under DCF. Accordingly, this study proposes Rapidly Adaptive Collision Backoff (RACB) algorithm, which adjusted dynamically based rate, as analyzed by mathematical model. Notably, RACB requires no knowledge number wireless and applicable both lightly loaded heavily networks. numerical results show that, adjusting such that rate maintained at close 0.1, enables DCF environments containing nodes.