An Analytical Model for IEEE 802.11 DCf

摘要

In wireless LANs, the medium access control (MAC) protocol is the main factor that determines the efficiency of the transmission in the shared wireless channel. In IEEE 802.11, the Distributed Coordination Function (DCF) adopts a Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) and an exponential binary backoff scheme to combat packet collisions. In this paper, an analytical study is presented to model the saturated throughput of both basic access mechanism and the optional RTS/CTS mechanism of 802.11 DCF. Similar to some previous papers, our model is also based on Markov Chain. However, we correct some mistakes and omissions in other's papers and derive a more accurate model with a new state transition diagram. Through elaborate simulations, we validate the accuracy of our model by compare the results of analytical modeling and experiments.