By analyzing the performance of the IEEE 802.11 DCF(Distributed coordination funclion)

this paper discovers that the probability distribution of slot selection of the IEEE 802.11 DCF is obviously not uniform.This gives high packet collision probability.For this reason

this paper provides a simple scheme

named A-DCF.Through simulation of IEEE 802.11 DCF and A-DCF

it proves that A-DCF has more uniform probability distribution of slot selection and lower packet collision probability at almost the same saturation throughput.At the same time

A-DCF is adaptive to the network load.