Efficiency of energy detectors under multiple access coexistence schemes

This paper examines the efficiency of employing energy detectors in a multi-user network, whose nodes are spatially distributed in a geographic area and employ a CSMA MAC protocol to access the channel. It has been observed that explicit expressions for the analysis of imperfect physical carrier-sensing MAC protocols using energy detection are non-existent in the literature. We, therefore, present simple expressions to achieve this for two protocols. Firstly, the mandatory physical carrier-sensing protocol is examined under the distributed coordination function of the IEEE 802.11 standard. Thereafter, a protocol which includes an optional virtual carrier-sensing scheme is examined alongside the physical carrier-sensing protocol. In this manner, the effect of CSMA inhibition zones arising due to neighbour node deactivation by the protocol is investigated. System parameters such as the energy detector detection threshold, the node density and the radius of inhibition are also studied and the analytical expressions are validated with Monte Carlo simulations.