國立臺灣師範大學電機工程學系Chiapin Wang and Tsungnan Lin2014-10-302014-10-302008-11-011536-1276�http://rportal.lib.ntnu.edu.tw/handle/20.500.12235/32303In this paper we investigate the throughput performance of IEEE 802.11 distributed coordination function (DCF) in the presence of physical-layer (PHY) inequality, i.e. varied channel conditions and/or unequal data rates determined by the Link Adaptation (LA) scheme. We present a theoretical model for DCF protocol with the LA scheme of auto rate fallback (ARF). The analysis results show that the system throughput of DCF-based WLANs is determined by the lowest data rate used with stations; throughput sharing among stations depends on the variation of link qualities rather than the difference of data rates. The simulation results validate the accuracy of our analytical model.IEEE 802.11 WLANDCFperformance analysis.