Efficient and practical query scoping in sensor networks

We propose Voronoi scoping, a distributed algorithm to constrain the dissemination of messages from different sinks. It has the property that a query originated by a given sink is forwarded only to the nodes for which that sink is the closest (under the chosen metric). Thus each query is forwarded to the smallest possible number of nodes, and per-node dissemination overhead does not grow with network size or with number of sinks. The algorithm has a simple distributed implementation and requires only a few bytes of state at each node. Experiments over a network of 54 motes confirm the algorithm's effectiveness.