Sensor Queries: Algebraic Optimization for Data Quality, Time and Energy

Sensor databases extend database technology to query and monitor the physical world as a highly distributed database. In this paper we consider a Data Transmission Algebra (DTA) that allows a query optimizer to utilize lower layer communication protocols in scheduling sensor database queries. By being able to determine the order in which data are processed at sensor nodes and transmitted between sensor nodes in a query routing tree, a query optimizer can both improve the response time and reduce the energy consumption per query. We use a logical framework to specify DTA semantics and to prove its soundness and completeness. Further, we prove that DTA query execution schedules have the key property of being collision-free.