Distributed Histograms for Processing Aggregate Data from Moving Objects

For monitoring moving objects via wireless sensor networks, we introduce two aggregate query types: distinct entries to an area and the number of objects in that area. We present a new technique, Distributed Euler Histograms (DEHs), to store and query aggregated moving object data. Aggregate queries occur in a variety of applications ranging from wildlife monitoring to traffic management. We show that DEHs are significantly more efficient, in terms of communication and data storage costs, than techniques based on moving object identifiers and more accurate than techniques based on simple histograms.