Jamming attacks in 802.11g - A cognitive radio based approach

Wireless networks are susceptible to jamming attacks, which can severely reduce the network throughput. In this paper, we study the behavior and the performance of 802.11g networks under a hybrid jamming attack of configuring a cognitive radio as a jammer. With characteristics such as fast channel switching, quick response time and software reconfigurability, cognitive radios can be used not only to improve the spectrum sharing management, but also to act as an effective jammer. We use a single cognitive radio to simultaneously jam three networks in an energy efficient manner and also to deny any channel change protocol by the targeted network to avoid jamming. We attack the `g' band OFDM channels directly using the fast channel switching capability of the cognitive radio. The jammer sequentially senses traffic on each of the networks without being part of any network. We present the results of the jamming attacks at the MAC and physical layers. We show how the cognitive radio can dynamically adjust its attack to the traffic on each network. We evaluated the performance of three networks individually and together under intelligent and reactive jamming.