MAC layer misbehavior detection and reaction in wireless networks

Abstract

IEEE 802.11 wireless LAN medium access control (MAC) provides transmission fairness to nodes in a network. A misbehaving node can modify its MAC and operate in a selfish manner to improve its own performance (throughput) at the expense of other nodes’ performance. In this thesis, new misbehavior detection and reaction mechanisms are proposed and evaluated, and their effect on throughput and fairness is studied. This thesis proposes a new criteria for misbehavior detection: the inter-packet transmission (IPT) time. Nodes maintain a moving average of their own IPT time and also maintain the moving average of neighboring nodes’ IPT times. The ratio of a node’s own IPT time to its neighbors’ IPT time is calculated, and if this ratio exceeds a predetermined threshold, then the presence of misbehavior is detected. When a misbehavior is detected in the network, genuine nodes react by collectively misbehaving, based on the extent of misbehavior in the network, in order to decrease the performance of the misbehaving nodes and also to improve their own performance. It has been shown using extensive simulations that the newly proposed metric of inter-packet transmission time is very effective in designing misbehavior detection and reaction schemes. Reaction effectiveness greater than 85% is achieved in all scenarios considered.