The influence of flat Rayleigh fading channel with hidden terminals and capture over the IEEE 802.11 WLANs

Considering imperfect physical and virtual carrier sensing caused by Rayleigh fading, we analyze the probability of a hidden station occurrence, P_h, as a function of the cell radius. We also derive analytical expressions for the probability of frame capture, P _capture, and saturation throughput, assuming that two discrete mean-power levels of transmitted frames at the receiver occur with equal probability. The simulations prove the validity of such a capture model assuming 20 dB difference between the two power levels. As expected, throughput improvement under capture is observed only when the given RTS/CTS "handshake" transmission scheme is not used