On Order Gain of Backoff Misbehaving Nodes in CSMA/CA-based Wireless Networks

Backoff misbehavior, in which a wireless node deliberately manipulates its backoff time, can induce significant network problems, such as severe unfairness and denial-of-service. Although great progress has been made towards the design of countermeasures to backoff misbehavior, little attention has been focused on quantifying the gain of backoff misbehaviors. In this paper, we define and study two general classes of backoff misbehavior to assess the gain that misbehaving nodes can obtain. The first class, called continuous misbehavior, keeps manipulating the backoff time unless it is disabled by countermeasures. The second class is referred to as intermittent misbehavior, which tends to evade the detection by countermeasures by performing misbehavior sporadically. Our approach is to introduce a new performance metric, namely order gain, which is to characterize the performance benefits of misbehaving nodes in comparison to legitimate nodes. Through analytical studies, simulations, and experiments, we demonstrate the impact of a wide range of backoff misbehaviors on network performance with respect to the number of users in CSMA/CA-based wireless networks.