Energy-Efficient Data Gathering in Heterogeneous Wireless Sensor Networks

This paper considers a heterogeneous wireless sensor network consisting in several resource-rich supernodes used for data relaying and a large number of energy constrained wireless sensor nodes. Sensor nodes are deployed randomly to monitor a number of targets. Since targets are redundantly covered by more sensors, in order to conserve energy resources, we organize the sensors in set covers that are activate successively. In this paper we introduce the heterogeneous connected set covers (HCSC) problem that has as objective finding a maximum number of set covers such that each set cover monitors all targets and is connected to at least one supernode. A sensor can participate in multiple set covers, but sum of the energy spent in all sets is constrained by the initial energy resources. This is the first paper to address the target coverage problem in heterogeneous wireless sensor networks. We show that HCSC is NP-complete and propose several distributed algorithms for the HCSC problem. Simulation results are presented to verify our approaches