Abstract
The 802.11 standard specifies mechanisms for channel access, data delivery, authentication and privacy for wireless communication. The standard makes no provisions for faulty, selfish or malicious behavior assuming that nodes always
act according to the specifications of the protocol. Thus, nodes running defective protocol implementations, misconfigured, or compromised can potentially cause significant disruption in the network. In this paper we present an analysis of
channel access denial of service attacks against 802.11b. We demonstrate the attacks through simulation and analyze them by considering the effect of multiple attackers, their relative positioning and the influence of the choice of high level protocols. In addition, we identify and describe new attacks against the beacon-based synchronization mechanism used for channel access and by the power saving mode in 802.11a, b, and g. We provide simulation results that demonstrate their feasibility and analyze them considering the attacker's effort versus the induced damage and effect on other protocols and services. Finally, we propose and discuss mitigation techniques for all the above attacks, demonstrating the efficacy of several of them through simulations.
