Adaptive topologies against jamming attacks in wireless networks: A game-theoretic approach

Towards securing wireless networks and ensuring their dependability under jamming attacks, this paper presents and analyzes game-theoretic formulations between an adversary and a defender. The adversary jams a subset of nodes to increase the level of interference in the network, while the defender makes judicious adjustments of the transmission power level of the nodes, thereby continuously adapting the underlying network topology to reduce the impact of the attack. The defender's strategy is based on playing Nash equilibria (NE) strategies securing a worst-case network utility. First, a discrete control set is considered in which the space of strategies of the defender grows exponentially with the network size. Scalable decomposition-based approaches are developed yielding a defense strategy whose performance closely approaches that of the non-decomposed game. Second, we develop a marginal strategy to assign the power levels while satisfying a coverage constraint thereby evading the combinatorial complexity associated with enumerating all pure actions. Third, we generalize the marginal based strategy by considering a continuous action space for both players. For this setting, we prove the existence of a unique pure Nash equilibrium. The presented numerical results show the effectiveness of the proposed defense approach against various attack policies and demonstrate the assignment strategies on a real wireless network deployed in a three-story building.