Cross-layer performance analysis for CSMA/CA system: Impact of imperfect sensing

Abstract

The performance of the carrier sense multiple access/collision avoidance (CSMA/CA) protocol under the presence of carrier sensing errors is analyzed. Two types of carrier sensing errors, false alarm and miss detection, are considered, and their impact on system performance is analyzed using a new CSMA/CA model based on a Markov chain capturing the sensing errors at the physical layer. The throughput as a function of these sensing error probabilities as well as other CSMA/CA parameters is obtained. It is shown that the throughput loss by a poorly chosen sensing threshold is tolerable at intermediate values of the ratio of the packet size to the contention window size, whereas care should be taken in choosing the sensing threshold when the ratio is small or large.