Energy aware routing for spatio-temporal queries in sensor networks

Wireless sensor networks form an emerging technology that can significantly improve the quality of spatio-temporal data monitoring because of their untethered operation and potential for large scale deployment. We define a communication architecture that supports distributed query processing to evaluate spatio-temporal queries within the network. We represent these queries by query trees and distribute query operators to appropriate sensor nodes. As operator execution demands high computation capability, we propose the use of a heterogenous sensor network where query operators are assigned to sparsely deployed resource-rich nodes within a dense network of low power sensor nodes. We design an adaptive, decentralized, low communication overhead algorithm to determine an operator placement on the resource-rich nodes in the network to minimize cost of transmitting data along a routing tree constructed to retrieve data continuously at the sink from a set of spatially distributed geographical regions. To the best of our knowledge, this is the first attempt to build an energy aware routing infrastructure to enable in-network processing of spatio-temporal queries.