Avoidance of Blind Period for Node Coverage Grouping on Wireless Sensor Networks

In our previous work, we proposed a novel approach to partition sensors on wireless sensor network, called node coverage grouping (NCG), where sensors in the connectivity group are within sensing range of each other, and their collected data are assumed to be similar. Power saving was achieved by alternatively turning on a sensor in a connectivity group for working. We also proved that partitioning n nodes by node coverage grouping into connectivity groups is a NP-hard problem, and proposed a heuristic algorithm of node coverage grouping with the time complexity of O(n3). In this paper, we present two approaches, called periodic probing and next-turn probing, to address the avoidance of blind period for the node coverage grouping. The experimental results showed that the NCG applying the avoidance of blind period would have shorter blind period than two other power saving approaches on wireless sensor network, the Lightweight Deployment-Aware Scheduling (LDAS) and the Probing Environment and Adaptive Sleeping (PEAS). In conclusion, the NCG-next-turn probing outperformed the LDAS and the PEAS with more number of living nodes, more coverage, and shorter blind period with respect to the proceeding of the system lifetime.