Analysis of unsaturation throughput of IEEE 802.11 DCF

Most analytical models proposed so far for IEEE 802.11 distributed coordination function (DCF) focus on saturation performance. In this paper, we develop an analytic model for unsaturation throughput evaluation of IEEE 802.11 DCF, based on Bianchi's model (2000). The model explicitly takes into account both the carrier sensing mechanism and an additional backoff interval after successful frame transmission, which can be ignored under saturation conditions. Expressions are derived by means of the equilibrium point analysis. The accuracy of our model is validated through computer simulation.