Fixed contention window backoff scheme for the contention-based IEEE 802.11 MAC

In order to develop a contention-based MAC with quality of service (QoS) guarantee based on the distributed coordination function (DCF), we investigate the backoff scheme. We optimize the channel utilization with the constraint that delay requirement is guaranteed. Based on our analysis data, we propose the fixed contention window backoff (FCWB) scheme to get the best performance. The optimal performance can be simply achieved by setting the minimum contention window and the transmission opportunity (TXOP) to the values derived from our procedure.