Denial of service attacks at the MAC layer in wireless ad hoc networks

We analyze attacks that deny channel access by causing pockets of congestion in mobile ad hoc networks. Such attacks would essentially prevent one or more nodes from accessing or providing specific services. In particular, we focus on the properties of the popular medium access control (MAC) protocol, the IEEE 802.11x MAC protocol, which enable such attacks. We consider various traffic patterns that an intelligent attacker might generate in order to cause denial of service. We show that conventional methods used in wire-line networks are unable to help in prevention or detection of such attacks. Our analysis and simulations show that providing MAC layer fairness alleviates the effects of such attacks.