Optimized Wireless Sensor Network Federation in Environmental Applications

Federating partitioned Wireless Sensor Networks (WSNs) in Outdoor Environment Monitoring (OEM), where the deployed sensor nodes are prone to significant damage and harsh operational conditions, becomes a necessity to prolong the WSN lifetime. Consequently, redundancy-based deployment strategies have been extensively studied in the literature. However, federating WSNs using node redundancy is expensive in OEM due to large-scale targeted areas, and frequent node/link failures. A natural choice in defeating these challenges is to employ multiple Data Collectors (DCs) that provide extendable and sustainable WSNs in harsh environments for long lifetime intervals. In this paper, we propose a grid-based deployment for DCs in which they are optimally repositioning on the grid vertices to connect disjointed WSN sectors. Towards this optimality, we design an Optimized DCs Repositioning (ODR) approach that maximizes the federated WSN lifetime while maintaining cost and connectivity constraints. The performance of the proposed approach is validated and assessed through extensive simulations and comparisons assuming practical considerations in outdoor environments.