Effective Backoff Scheme to ease the Network Congestion on IEEE 802.11 DCF

Abstract

Since all transmitting stations in the range share the wireless channel, the IEEE 802.11 MAC uses the Binary Exponential Backoff (BEB) algorithm to minimize collision. The BEB technique resets the Contention Window values after each successful frame transmission regardless of the network state, and a sudden CW decrease incurs performance degradation as the number of competing stations increases. To resolve this problem, we propose a new algorithm that adjusts CW values using (m,k)-firm scheduling technique. The proposed algorithm changes CW using the violating distance instead of resetting the CW to minimum value after every successful transmission. The performance results are shown to identify the improvement of our scheme in terms of waiting time comparing to the BEB.