Performance of IEEE 802.11 under Jamming

Abstract

We study the performance of the IEEE 802.11 MAC protocol under a range of jammers that covers both channel-oblivious and channel-aware jamming. We consider two channel-oblivious jammers: a periodic jammer that jams deterministically at a specified rate, and a memoryless jammer whose interfering signals arrive according to a Poisson process. We also develop new models for channel-aware jamming, including a reactive jammer that only jams non-colliding transmissions and an omniscient jammer that optimally adjusts its strategy according to current states of the participating nodes. Our study comprises of a theoretical analysis of the saturation throughput of 802.11 under jamming, an extensive simulation study, and a testbed to conduct real world experimentation of jamming IEEE 802.11 using a software defined radio (GNU Radio combined with USRP boards). In our theoretical analysis, we use a discrete-time Markov chain analysis to derive formula for the saturation throughput of 802.11 under memoryless, reactive and omniscient jamming. One of our key results is a characterization of optimal omniscient jamming that establishes a lower bound on the saturation throughput of 802.11 under arbitrary jammer attacks. We validate the theoretical analysis by means of Qualnet simulations. Finally, we measure the real-world performance of periodic, memoryless and reactive jammers using our GNURadio/ USRP aided experimentation testbed.