Fault-tolerant aggregator election and data aggregation in wireless sensor networks

Abstract

This paper presents three algorithms for aggregator election and data aggregation in wireless sensor networks where sensors can crash and recover. The network is divided in several regions. The algorithms ensure the election of a common data aggregator sensor within each region, in charge of the collection of local data and the election of a unique super-aggregator sensor, in charge of the collection of global data, among all the aggregators. Both elections are achieved by implementing the Omega failure detector, which provides a self-organising and fault-tolerant leader election service. Each algorithm is based on a different connectivity assumption. The first algorithm assumes that every pair of sensors in a region can communicate directly. The second algorithm only requires some correct sensor to communicate directly with the rest of sensors. Finally, the third algorithm only requires the existence of a multi-hop bidirectional path from some correct sensor to the rest of sensors. We also introduce a battery depletion threshold to enhance the quality of service of the wireless sensor network.