On Adjusting Power to Defend Wireless Networks from Jamming

Wireless networks are susceptible to accidental or intentional radio interference. One way to cope with this threat is to have the radios compete with the jammer, whereby the network nodes adapt their transmission power to improve the chance for successful communication. In this paper, we examine issues associated with using power control both theoretically and experimentally. We begin by examining the two-party, single-jammer scenario, where we explore the underlying communication theory associated with jamming. We note that the effect of the jammer upon source-receiver communications is not isotropic. We then discuss the potential for improving communication reliability through experiments conducted using Mica2 motes, and in particular explore the feasibility of power- control for competing against jammers. Next, we turn to examining the more complicated scenario consisting of a multi- hop wireless network. We show the complex jamming effect by applying the non-isotropic model of jamming to a multi-hop wireless network, and it is necessary to have a feed-back based power control protocol to compete with jamming interference.