Maximizing α-Lifetime for Wireless Sensor Networks

In energy constrained wireless sensor networks, it is very important to conserve energy and prolong network lifetime while ensuring proper operations of the network. In this paper, we investigate how to maximize the α-lifetime of wireless sensor networks, where α-lifetime is defined as the time duration during which at least α portion of the surveillance region is covered. We first present, given node locations, two upper bounds of the α-lifetime. We then design, based on the derived upper bound, an algorithm that suboptimally schedules node activities to maximize the α-lifetime of a sensor network. We carry out simulations to validate the derived results and evaluate the designed algorithm. Simulation results show that the proposed algorithm achieves around 90% of the derived upper bound. This implies that the derived upper bounds are rather tight and the proposed algorithm is close to optimal. Finally, we draw from our study several useful conclusions on sensor network deployment and design.