2. Modeling the Impact of Jamming Attacks on Time-Critical Traffic with Applications to Smart Grid

In this chapter, we aim at modeling and detecting jamming attacks against time-critical wireless networks with applications to the smart grid. In contrast to communication networks where packets-oriented metrics, such as packet loss and throughput are used to measure the network performance, we introduce a new metric, message invalidation ratio, to quantify the performance of time-critical applications. Our modeling approach is inspired by the similarity between the behavior of a jammer who attempts to disrupt the delivery of a time-critical message and the behavior of a gambler who tends to win a gambling game. Therefore, by gambling-based modeling and real-time experiments, we find that there exist a phase transition phenomenon for successful time-critical message delivery under a variety of jamming attacks. That is, as the probability that a packet is jammed increases from 0 to 1, the message invalidation ratio first increases slightly, then increases dramatically to 1. Based on analytical and experimental results, we design the jamming attack detection based on estimation (JADE) scheme to achieve efficient and robust jamming detection, and implement the JADE system in a wireless network for power substations in the smart grid.