Resilience to electromagnetic jamming and its avoidance are difficult problems. It is often both hard to distinguish malicious jamming from congestion in the broadcast regime and a challenge to conceal the activity patterns of the legitimate communication protocol from the jammer. In the context of energy-constrained wireless sensor networks, nodes are scheduled to maximize the common sleep duration and coordinate communication to extend their battery life. This results in well-defined communication patterns with possibly predictable intervals of activity that are easily detected and jammed by a statistical jammer. We present an anti-jamming protocol for sensor networks which eliminates spatio-temporal patterns of communication while maintaining coordinated and contention-free communication across the network. Our protocol, WisperNet, is time-synchronized and uses coordinated temporal randomization for slot schedules and slot durations at the link layer and adapts routes to avoid jammers in the network layer. Through analysis, simulation and experimentation we demonstrate that WisperNet reduces the efficiency of any statistical jammer to that of a random jammer, which has the lowest censorship-to-link utilization ratio. WisperNet is more energy efficient than low-power listen CSMA protocols such as B-mac and is simple to analyze in terms of effective network throughput, reliability and delay. WisperNet has been implemented on the FireFly sensor network platform.
Date of this Version
Embedded systems, wireless networks, jamming, security, fault-tolerant systems, embedded systems, jamming, protocols, random processes, statistical analysis, synchronisation, telecommunication congestion control, telecommunication network reliability, wireless sensor networks, WisperNet time-synchronized protocol, anti jamming protocol, battery life maximization, censorship-to-link utilization ratio, communication protocol, contention-free communication, coordinated temporal randomization, electromagnetic jamming, embedded wireless network, energy-constrained wireless sensor network, link layer slot duration, link layer slot schedule, malicious jamming, node scheduling, random jammer, spatio-temporal pattern, statistical jammer, Anti-jamming, MAC protocol, wireless sensor networks
Date Posted: 16 February 2010
This document has been peer reviewed.