Detecting MAC Layer Collision Abnormalities in CSMA/CA Wireless Networks

We present a robust non-parametric detection mechanism for CSMA/CA MAC layer denial-of-service attacks that does not require any modification to the existing protocols. This technique, based on the M-truncated sequential Kolmogorov- Smirnov statistics, monitors the successful transmissions and the collisions of the terminals in the network, and determines how ´explainable´ the collisions are given such observations. We show that the distribution of explainability of the collisions is very sensitive to abnormal changes in the network, even with a changing number competing terminals. NS-2 simulation results show that the proposed method has a very short detection latency and high detection accuracy.