Query Processing for Sensor Networks

Hardware for sensor nodes that combine physical sensors, actuators, embedded processors, and communication components has advanced significantly over the last decade, and made the large-scale deployment of such sensors a reality. Applications range from monitoring applications such as inventory maintenance over health care to military applications. In this paper, we evaluate the design of a query layer for sensor networks. The query layer accepts queries in a declarative language that are then optimized to generate efficient query execution plans with in-network processing which can significantly reduce resource requirements. We examine the main architectural components of such a query layer, concentrating on in-network aggregation, interaction of in-network aggregation with the wireless routing protocol, and distributed query processing. Initial simulation experiments with the ns-2 network simulator show the tradeoffs of our system.