Malicious or Selfish? Analysis of Carrier Sense Misbehavior in IEEE 802.11 WLAN

The behavior of selfish users, which does not respect the backoff procedure of IEEE 802.11 WLAN, has been nicely studied in game-theoretic frameworks. However, in these studies, the effect of physical carrier sense has not been properly incorporated into the analysis. In this paper, we study the problem of how carrier sense misbehavior can affect network performance in addition to backoff misbehavior. Our analysis shows that a cheater can increase its throughput by ignoring the carrier sense mechanism while a well-behaved user significantly loses its throughput. Consequently, not only a malicious user, but also a selfish one is motivated to disregard the carrier sense mechanism, which will result in significant throughput degradation of well-behaved ones. Our analysis also shows that carrier sense misbehavior corresponds to the case of virtually increasing the channel access probability of the cheater in the backoff procedure. We provide our preliminary simulation results, which verify our analysis.