Optimizing the Lifetime of Heterogeneous Sensor Networks Under Coverage Constraint : MILP and Genetic Based Approaches

Lifetime optimization in heterogeneous wireless sensor networks (HWSN) is investigated in this paper. This is a natural and important key issue which serves as a basis metric for QoS of the monitoring activity. To tackle this problem, nodes' clustering into Disjoint or Non Disjoint Cover Sets is the well-known technique that has been heavily studied in the literature. The objective is to organize the sensor nodes into a number of subsets of nodes that are activated successively. Only the nodes belonging to an active cover are responsible for targets' monitoring, while all other sensors are in a sleep mode. The presented paper is, to the best of our knowledge, the first work to consider the heterogeneity level of nodes' batteries in the case of Disjoint Set Covers (HDSC) based scheduling. To this end, first a novel mixed integer linear programming (MILP) formulation is proposed to solve optimally the HDSC problem, next we provide a genetic algorithm (GA) based approach to achieve approximate solutions but in polynomial time complexity. A comprehensive set of experimental results were conducted to assess the behavior of our proposals in terms of several QoS metrics.