DAO-R: Integrating Data Aggregation and Offloading in Sensor Networks via Data Replication

We study overall storage overflow problem in sensor networks, wherein data-collecting base station is not available while more data is generated than available storage spaces in the entire network. Existing research designs a two-stage solution to solve this problem. It first aggregates overflow data to the size that can be accommodated by the available storage capacity in the network, and then offloads the aggregated data into the network to be stored. We refer to this naive two-stage solution as DAO-N. In this paper, we demonstrate that this approach does not necessarily achieve good performance. We propose a more unified method that is based upon data replication techniques, referred to as DAO-R, in order to improve the performance of DAO-N. Specifically, we design two energy-efficient data replication algorithms to integrate data aggregation and data offloading in DAO-N. We show via extensive simulations that DAO-R outperforms DAO-N by around 30% in terms of energy consumption under different network parameters.