Intelligent Jamming in 802.11b Wireless Networks

Total physical jamming in wireless networks can be realized by generating continuous high power noise in the vicinity of wireless receiver nodes. The purpose of this paper is to show, using OPNET simulations, that similar jamming effectiveness can be achieved with much lower total energy. In the first half of the paper, we study the effects of periodic jamming with various power levels on the network throughput. IEEE 802.11b has two different DCF modes: basic CSMA/CA and RTS/CTS mechanism. Based on these parameters and the numerical results obtained, we discuss the effectiveness of periodic jamming of these modes. In the second half of the paper, we look at the jamming mechanisms that exploit crucial intervals and control messages in both of these modes and hence add some intelligence to the jammer. We use OPNET 10.0 to simulate various types of jamming which we propose. Intelligent jamming, which jams with the knowledge of the protocol, is shown to perform significantly better than the trivial continuous high power noise jamming while also retaining its effectiveness. Intelligent jamming appears to be one to two orders of magnitude more efficient than periodic jamming and up to five orders of magnitude more efficient than trivial jamming.