Querying Uncertain Minimum in Wireless Sensor Networks

Date Added: Jul 2011
Format: PDF

In this paper, the authors introduce two types of probabilistic aggregation queries, namely, Probabilistic Minimum Value Queries (PMVQ)s and Probabilistic Minimum Node Queries (PMNQ)s. A PMVQ determines possible minimum values among all imprecise sensed data, while a PMNQ identifies sensor nodes that possibly provide minimum values. However, centralized approaches incur a lot of energy from battery-powered sensor nodes and well studied in-network aggregation techniques that presume precise sensed data are not practical to inherently imprecise sensed data. Thus, to answer PMVQs and PMNQs energy-efficiently, they devised suites of in-network algorithms. For PMVQs, their in-network Minimum Value Screening algorithm (MVS) filters candidate minimum values; and their in-network Minimum Value Aggregation algorithm (MVA) conducts in-network probability calculation.