Report on ACQUIRE project

Querying in wireless sensor networks is tightly linked to how data is stored among the sensor nodes. There has been considerable work in the literature that treats a sensor network as a distributed database and proposes schemes that store data in a structured fashion ([1], [2], [3], [4]). Querying in such scenarios reduces to efficient retrieval of data from this distributed database. The other approach (like ACQUIRE ([5]), ERS ([8]), Rumor Routing ([9])) is unstructured in the sense that the querying entity is not aware of the location of the data it is looking for. While both these approaches are meant for the same purpose, it is not clear which one is better. Intuitively, the optimal approach would involve a combination of intelligent storage and querying and would depend on the objective in mind as well as the type of query, application requirements and the spatio-temporal characteristics of the data. In this project and its future work, we plan to identify such scenarios and gain insights into the nature of the optimal strategies. Recent work on optimization of querying operation in Wireless Sensor Networks (WSN) has focused on following dimensions: