Query domains: Grouping heterogeneous sensors based on proximity

Efficient query processing in sensor networks involves identifying groups of nodes that coordinate to satisfy applications' requests. In this paper, we propose a query domain abstraction that allows an application to dynamically specify the nodes best suited to answering a particular query. To self-organize into such a coalition, nodes must satisfy a proximity function, a user-definedfunction that constrains the relative relationship among the group of nodes (e.g., based on a property of the network or physical environment or a logical property of the nodes). The proximity function removes the need to explicitly tag nodes with context information, and it provides a convenient mechanism for forming coalitions on-the-fly at query time. This facilitates the deployment of general-purpose sensor networks, where multiple applications can be run in the same network at the same time. In this paper, we model this abstraction, present a protocol to support the abstraction, and evaluate their performance.