Optimal Scheduling of Sensors´ States to Maximize Network Lifetime in Wireless Sensor Networks

In this paper, we address the problem of maximizing sensor networks lifetime under area coverage constraint. For that, we propose a scheduling mechanism that calculates, for every time slot of the network operating period, an optimal covering subset of sensors that will be activated while all other sensors will go on Sleep. This mechanisms aims to balance energy dissipation over sensors, thus maximizing network lifetime. We model this problem as an Integer Linear Programming (ILP) problem, that we resolve using ILOG CPLEX and we show that the obtained solutions provide for more balanced energy consumption when we increase a balancing exponent lambda, which increases network lifetime. We finally propose a greedy heuristic that could be implemented to tackle the exponentially-increasing processing time of CPLEX.