Abstract: This paper presents a novel a
lgorithm, called Enhanced Distributed Contention Control, for improving the perf
ormance of DCF(Distributed Coordination Function) Operations of IEEE 802.11 Wir
eless LAN(WLAN). The EDCC algorithm is an extension of the existing DCC algorith
m by applying a more precise scheme for estimation of the values of slot utiliza
tion and contention degree. The Enhanced DCC algorithm reduces the distortion of
estimating slot utilization by using an ARMA Filter method to utilize the succe
ssive estimating value of slot utilization compared with the DCC algorithm avail
able. At the same time, the EDCC algorithm keeps the main characteristics: simpl
icity, integrability, complete distribution, Absence of overheads, and adaptiven
ess. Results show that the EDCC algorithm can provide higher channel utilization
and lower network load compared with the DCC algorithm existing.

Key words: IEEE 802.11 protocol, DCF, DCC, EDCC, ARMA filter