DATE: | Monday, Oct. 30, 2006 |
TIME: | 2:30 pm |
PLACE: | Council Room (SITE 5-084) |
TITLE: | Near-optimal Sensor Placements: Maximizing Information while Minimizing Communication Cost |
PRESENTER: | Carlos Guestrin Carnegie Mellon University |
ABSTRACT:
When monitoring spatial phenomena with wireless sensor networks,
selecting the best sensor placements is a fundamental task. Not only
should the sensors be informative, but they should also be able to
communicate efficiently. In this talk, I will present our data-driven
approach that addresses the three central aspects of this problem:
measuring the predictive quality of a set of sensor locations
(regardless of whether sensors were ever placed at these locations),
predicting the communication cost involved with these placements, and
designing an algorithm with provable quality guarantees that optimizes
the NP-hard tradeoff. Specifically, we use data from a pilot
deployment to build non-parametric probabilistic models called
Gaussian Processes (GPs) both for the spatial phenomena of interest
and for the spatial variability of link qualities, which allows us to
estimate predictive power and communication cost of unsensed
locations. Using these models, we present a novel efficient algorithm,
pSPIEL, which selects Sensor Placements at Informative and
cost-Effective Locations. Exploiting two important properties of this
problem -- submodularity and locality -- we prove strong approximation
guarantees for our pSPIEL approach. We also provide extensive
experimental validation of this practical approach on several
real-world placement problems, demonstrating significant advantages
over existing methods.
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