A Distributed Node Scheduling Protocol Considering Sensing Coverage in Wireless Sensor Networks

A crucial issue in deploying wireless sensor networks is to perform a sensing task in an area of interest in an energy-efficient manner since sensor nodes have limited energy power. The most practical solution to solve this problem is to use a node scheduling protocol that some sensor nodes stay active to provide sensing service, while the others are inactive for conserving their energy. In this paper, we present a distributed node scheduling protocol, which can maintain sensing coverage required by applications and yet increase network lifetime by turning off some redundant nodes. In order to do this, we use the concept of an effective sensing area (ESA). The ESA of a sensor node refers to the sensing area that is not overlapping with other sensor's sensing area. A sensor node determines whether it will be active or not after calculating its own ESA. The proposed protocol allows sensor nodes to sleep opportunistically while satisfying the required sensing coverage. Through extensive simulation experiments, we have observed significant improvement in terms of network lifetime, which we have compared with the existing protocols.