Effectiveness of Physical and Virtual Carrier Sensing in IEEE 802.11 Wireless Ad Hoc Networks

Abstract – IEEE 802.11 defines physical and virtual carrier sensing mechanisms to avoid interference in wireless local area networks for the kind of interference originating from within the receiving range of a receiver. However, in wireless ad hoc networks most interference comes from outside of this range. So, the effectiveness of IEEE 802.11 carrier sensing mechanism in ad hoc networks has attracted many studies. Prior research has attempted to evaluate effectiveness from a spatial viewpoint only, using an analytical model to estimate the size of the interference area of an ongoing communication based on the transmitter-receiver distance. Unlike this, the temporal effectiveness of the carrier sensing mechanism has been ignored. In this paper we propose an analysis combining spatial and temporal viewpoint to study the effect of interference on the performance of IEEE 802.11 protocol in ad hoc networks. We also compare the effectiveness of physical and virtual carrier sensing mechanisms, known as RTS/CTS mechanism, in wireless ad hoc networks. I