Querying the physical world

In the next decade, millions of sensors and small-scale mobile devices will integrate processors, memory, and communication capabilities. Networks of devices will be widely deployed for monitoring applications. In these new applications, users need to query very large collections of devices in an nd hoc manner. Most existing systems rely on a centralized system for collecting device data. These systems lack flexibility because data is extracted in a predefined way. Also, they do not scale to a large number of devices because large volumes of raw data are transferred. In our new concept of a device database system, distributed query execution techniques are applied to leverage the computing capabilities of devices, and to reduce communication. In this article, we define an abstraction that allows us to represent a device network as a database and we describe how distributed query processing techniques are applied in this new context.