Coverage-aware sensor engagement in dense sensor networks

Abstract

Wireless sensor networks are capable of carrying out surveillance missions for various applications in remote areas without human interventions. An essential issue of sensor networks is to search for the balance between the limited battery supply and the desired lifetime of network operations. Beside data communication between sensors, maintaining sufficient surveillance, or sensing coverage, over a target region by coordination within the network is critical for many sensor networks due to the limited supply of energy source for each sensor. This paper presents a novel sensor network coverage maintenance protocol, called Coverage-Aware Sensor Engagement (CASE), to efficiently maintain the required degree of sensing coverage by activating a small number of sensors while putting the others to sleep mode. Different from other coverage maintenance protocols, CASE schedules active/inactive sensing states of a sensor according to the sensor's contribution to the network sensing coverage, therefore preserving the expected behavior of the sensor network. Coverage contribution of each sensor is quantitatively measured by a metric called "coverage merit". By activating sensors with relatively large coverage merit and deactivating those with small coverage merit, CASE effectively achieves energy conservation while maintaining sufficient sensor network coverage. We provide simulation results to show that CASE considerably improves the energy efficiency of coverage maintenance with low communication overhead.