Multi-resolution state retrieval in sensor networks

Large-scale dense sensor networks require mechanisms to extract topology information that can be used for various aspects of sensor network management. It is critical for any topology discovery algorithm in dense networks not only to adhere to the resource constraints of bandwidth and energy but also to provide several views of the network. Due to factors of density, redundancy and failures it may not be possible or practical to get a complete view of the topology. We describe a distributed parameterized algorithm for Sensor Topology Retrieval at Multiple Resolutions (STREAM), which makes a tradeoff between topology details and resources expended. The algorithm retrieves network state at multiple resolutions at a proportionate communication cost. We also define various classes of topology queries and show how the parameters in the algorithm can be used to support queries specific to sensor networks. We show that topology determined at different resolutions is sufficient for approximating different network properties. We also show that STREAM can be used for general-purpose multi-resolution information retrieval in sensor networks.