Jamming in Wireless Networks Under Uncertainty

Abstract

Jamming is a form of a denial of service attack in which an adversary can degrade the quality of the reception by creating interference. One can study jamming both in the purpose of protecting a wireless network against such attack or, on the contrary, in order to efficiently disrupt the communications of some adversary. In both cases jamming is part of a conflict for which game theory is an appropriate tool. Here we investigate the effect of partially available information in which the user does not even know whether or not the jammer is indeed present. Moreover, the user does not know how jamming efforts are distributed among sub-carriers, nor does it know the fading channels gains. As an object function for the user we consider the SINR. We show that the problem can be formulated as a zero-sum game. We study independent fading channel gains scenario as well as the case of dependent fading channel gains, both in a discrete and a continuous versions. We show that in all the scenarii the jammer equalizes the quality of the best sub-carriers for the user on as low level as its power constraint allows. Meanwhile the user distributes his power among these jamming sub-carriers. We find the equilibrium strategies in closed form and specify the range of sub-carriers where the user can expect the jamming attack.