Real-Time Misbehavior Detection and Mitigation in Cyber-Physical Systems Over WLANs

In cyber-physical system (CPS) over IEEE 802.11e-based wireless local area networks (WLANs), a misbehaving node can gain significant advantage over other normal nodes in terms of resource sharing by deliberately manipulating its protocol parameters. Due to the random spectrum-access nature of the protocol, it is challenging to detect the misbehaving node accurately and in real-time. Moreover, many existing misbehavior detectors, primarily designed for traditional IEEE 802.11 networks, become inapplicable in IEEE 802.11e networks with heterogeneous network configurations. In this paper, we propose novel real-time and light-weight countermeasures including a hybrid-share misbehavior detector and a packet-dropping-based misbehavior mitigation mechanism for IEEE 802.11e-based CPS. We develop mathematical models for the performance of the proposed detector and mitigation mechanisms. Extensive simulation results show that the proposed mechanisms can achieve a high detection rate and punish a misbehaving node with a high packet dropping rate.