A survey on energy efficient coverage protocols in wireless sensor networks

A Wireless Sensor Network (WSN) is used to monitor an area for events. Each node in the WSN has a sensing range and a communication range. The sensing coverage of a sensor node is the area determined by the sensing range of the sensor node. Sensing coverage of the network is the collective coverage of the sensor nodes in a WSN. Sufficient number of sensor nodes need to be deployed to ensure adequate coverage of a region. Further, since sensor nodes have limited battery life, it is also essential to reduce the energy consumption. This would help improve the network lifetime and thus the coverage lifetime. To reduce energy consumption in the WSN, some of the nodes with overlapping sensing areas could be turned off using a coverage optimization protocol. In this paper, we discuss various coverage optimization protocols. These protocols are broadly classified as clustering and distributed protocols. Further, these protocols are classified based on the type of sensing model used, node location information, and mechanism used to determine neighboring node information (based on probe or computational geometry). In this paper, we review the key coverage optimization protocols and present open research issues related to energy efficient coverage.