Modified Backoff Algorithms for DFWMAC‘s1 Distributed Coordination Function

The distributed coordination function (DCF) in the upcoming standard for wireless LANs IEEE 802.11 is based on a CSMA/CA like access protocol. The collision avoidance part applies a rotating backoff window mechanism, that causes unequal collision probability distribution depending on the position of the selected slot within the contention window. We present simple modifications for the backoff mechanism using weighted probability distributions and a load adaptive scheme for the slots that result in a lower collision probability and therefore in higher throughput of up to 20%.