Probabilistic wakeup
Yanmin Zhu, Lionel Ming-shuan Ni · 2007
The persistent nature of physical events makes it possible to detect events using lowly duty-cycled sensors. However, it raises a serious over-detection problem when every sensor blindly wakes up in each cycle, in particular, if sensor density is high. In this paper, we propose an innovative probabilistic wakeup protocol for energy-efficient event detection in wireless sensor networks. The central idea is to reduce the duty cycle of every sensor via probabilistic wakeup, exploiting the dense deployment of sensor networks. A distinctive feature is that the system ensures that the detection delay of any event occurring anywhere in the sensing field is statistically bounded. In addition, the algorithm exposes a convenient interface for users to define the requirement on detection latency, thereby tuning the intrinsic tradeoff between energy efficiency and event detection performance. The algorithm is a lightweight and completely localized protocol, and introduces minimal communication overhead. Extensive experiments have been conducted and results demonstrate that this algorithm significantly prolongs the system lifetime.