Random backoff control to thwart malicious behavior in WLANs

Providing a fair and secure medium access scheme is a fundamental requirement in centralized wireless networks. However, IEEE 802.11 systems do not provide any fairness control mechanism and assume a cooperative behavior of participating nodes. We tackle the problem of misbehavior on the MAC layer, mainly the backoff manipulation attack, and we propose the Random Backoff Control (RBC) mechanism. This mechanism provides misbehavior detection by controlling the backoff selection process to ensure a fair distribution of network resources. Simulation results based on OMNeT++ show that RBC ensures a reasonable fairness in presence of selfish nodes and is indeed efficient in mitigating misbehavior on the MAC layer.