Abstract
Accurate analytical modeling of IEEE 802.11 distributed coordination function (DCF) is very important to characterize IEEE 802.11 medium access control (MAC) layer performance. The two backoff procedures used in the IEEE 802.11 DCF, namely pre-backoff and post-backoff procedures, are commonly treated as the same in existing analytical DCF models for simplicity. This paper makes the first effort to point out the difference between these two backoff procedures. Through intuitive reasoning and simulation results, we show that the two backoff procedures yield un-negligible differences in the performance of average access delay, but give the same performance of throughput.
