Decentralized energy-conserving and coverage-preserving protocols for wireless sensor networks

The wireless sensor network is an emerging technology that may greatly facilitate human life by providing ubiquitous sensing, computing, and communication capabilities. However, to maintain sufficient coverage and to achieve long system lifetime are two contradicting factors in designing the topology of a sensor network. We propose several decentralized protocols that schedule sensors´ active and sleeping periods to prolong the network lifetime while maintain the sensing field sufficiently covered. The proposed protocols are based on a model similar to that of T. Yan et al. (see ACM Int. Conf. on Embedded Networked Sensor Systems, SenSys, p.51-62, 2003), but improve their results in several senses. First, our approach can significantly reduce the computational complexity incurred, and at the same time achieve better accuracy in determining the coverage of the sensing area. Second, we enhance the results of Yan et al. by proposing an optimization mechanism to balance or reduce sensors´ energy expenditure further.