Decentralized Scattering of Wake-Up Times in Wireless Sensor Networks

Duty-cycling in wireless sensor networks (WSNs) has both beneficial effects on network lifetime and negative effects on application performance due to the inability of a sensor to perform while it is sleeping. In a typical scenario, the active periods of nodes are randomly initialized, leading to unpredictable and often sub-optimal performance. In this paper, we propose a fully decentralized wake-up scattering algorithm that uniformly spreads wake-up times of nearby sensors. Interestingly, our approach is complementary and dual to existing approaches that aim at synchronizing (instead of scattering) times, and to those that focus on spatial (instead of temporal) coverage. Wake-up scattering is beneficial in several application scenarios, three of which are considered here: responsiveness to one-hop queries from a mobile base station, sensing coverage for event detection, and latency in multi-hop communication. Our evaluation shows that, w.r.t. a random assignment of wake-up times, wake-up scattering brings improvements in all these measures, along with a positive impact on the network lifetime.