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Algorithms for Local Sensor Synchronization
MPhil Thesis Defence
Title: "Algorithms for Local Sensor Synchronization"
By
Mr. Lixing Wang
Abstract
In a wireless sensor network (WSN), each sensor monitors environmental
parameters, and reports its readings to a base station, possibly through other
nodes. A sensor works in cycles, in each of which it stays active for a fixed
duration, and then sleeps until the next cycle. The frequency of such cycles
determines the portion of time that a sensor is active, and is the dominant
factor on its battery life. The majority of existing work assumes globally
synchronized WSN where all sensors have the same frequency. This leads to waste
of battery power for applications that entail different accuracy of
measurements, or environments where sensor readings have large variability.
To overcome this problem, we propose LS, a query processing framework for
locally synchronized WSN. We consider that each sensor ni has a distinct
sampling frequency fi, which is determined by the application or environment
requirements. The complication of LS is that ni has to wake up with a network
frequency Fi>=fi, in order to forward messages of other sensors. Our goal is
to minimize the sum of Fi without delaying package transmissions.
Specifically, given a routing tree, we first present a dynamic programming
algorithm that computes the optimal network frequency of each sensor; then, we
develop a heuristic for finding the best tree topology, if this is not fixed in
advance.
Date: Wednesday, 29 February 2012
Time: 2:00pm – 4:00pm
Venue: Room 3401
Lifts 17/18
Committee Members: Prof. Dimitris Papadias (Supervisor)
Dr. Qiong Luo (Chairperson)
Dr. Raymond Wong
**** ALL are Welcome ****
