Connectivity of multi-channel wireless networks under jamming attacks

Jamming attacks can cause serious destruction to communication systems without much cost, especially when secret keys shared by the system are exposed. Uncoordinated Frequency Hopping (UFH) is an effective countermeasure to jamming attacks without dependence on pre-shared secret keys. In this paper we study the connectivity of a multi-channel network under jamming attacks, where each communication link can switch from regular transmission to UFH transmission when jamming attacks are detected. Under the framework of percolation theory, we show that as the jammer density increases, two phase transitions occur: from strong connection where there exists an infinite component composed of regular links, to weak connection where there exists an infinite component composed of both regular and UFH links, then to disconnection.