Real-time detection of MAC layer misbehavior in mobile ad hoc networks

The MAC layer misbehavior of the IEEE 802.11 standard can have a negative impact on the wireless network's performance, similar to the effects of denial of service attacks. The goal of this misbehavior was handling the protocol to increase the greedy nodes transmission rate at the expense of the other honest nodes. In fact, nodes in IEEE 802.11 standard should wait for a random backoff interval time to access to the channel before initiating any transmission. Greedy nodes use a malicious technique to reduce the channel waiting time and occupy the channel. This paper introduces a new scheme to detect such malicious behavior, which is based on statistical process control (SPC) borrowed from the industrial field in a quality management context. To the best of our knowledge, this approach has not been proposed in state of the art, reports concerning the detection of greedy behaviors in mobile ad hoc networks. The approach has the power to identify greedy nodes in real time by using a graphical tool called «control chart» that measures the throughput and the inter-packet interval time for each node, and raises an alert if this measure is over a defined threshold. The validation of all obtained results is performed in the network simulator NS2.