On the design of k-covered wireless sensor networks: Self-versus triggered sensor scheduling

Sensing coverage reflects the quality of surveillance of a field by a wireless sensor network (WSN). This paper investigates the problem of minimum connected k-coverage in WSNs, where each point in a field is covered (or sensed) by at least k active sensors while minimizing the necessary total number of active sensors and ensuring connectivity between them. In this paper, we propose two k-coverage protocols using different scheduling approaches. In the first protocol, called self-scheduling driven k-coverage (SSC_k), each sensor turns itself on based on the local information it has about its sensing neighbors in order to k-cover its sensing range. The second protocol, called triggered-scheduling driven k-coverage (TSC_k), allows a sensor to trigger a necessary number of its sensing neighbors to become active in order to achieve k-coverage of its sensing range. Then, we relax some commonly used assumptions for coverage configuration protocols in WSNs to promote the use of SSC_k and TSC_k in realworld sensing applications. Simulation results show that TSC_k outperforms SSC_k with regard to the number of sensors required for connected k-coverage as well as the network lifetime. We find that SSC_k outperforms an existing connected k-coverage protocol for WSNs.