Coverage for composite event detection in wireless sensor networks
A wireless sensor network can detect single (or atomic) events or composite events. Since sensors are battery powered and in general, it is hard to recharge them, energy management is always an important issue. In this paper, we study the SCED problem; given a wireless sensor network deployed for watching a composite event x(1), x(2),..., x(M), design a sensor scheduling mechanism such that the set of active sensors ensure the coverage and connectivity conditions and WSN lifetime is maximized. Network lifetime is organized in rounds. Each round has two phases: initialization and data collection. In the initialization phase, the goal is to choose a set of active sensors as sensing nodes or relay nodes such that to achieve both coverage and connectivity requirements. Sensors which are not chosen to be active go to sleep to save energy. In the data collection phase, active sensors perform sensing and data relaying. When another round begins, a new set of active sensors are determined. Two solutions are proposed for the SCED problem, a grid-based distributed algorithm and a localized algorithm. We analyze their performance through simulations. Copyright (C) 2010 John Wiley & Sons, Ltd.
coverage composite event detection wireless sensor networks connectivity