Algorithms
for
Local Sensor Synchronization
Lixing Wang
Yin Yang
Xin Miao
Dimitris Papadias
Yunhao Liu
ICDE 2011
Outline
• Introduction
• Related Work
• Problem Definition
• Finding Network Frequencies
• Experimental Evaluation
• Conclusions
Introduction
• In order to minimize energy consumption of
WSN, instead of sensors being on continuously,
they operate in cycles.
• Existing work has focused on query processing
in globally synchronized WSN, where all sensors
have the same frequency.
Introduction
• This propose LS (for local synchronization), a
novel framework that permits sensors to have
different frequencies.
• Given fi , the goal of LS is to determine a
network frequency Fi of each sensor ni .
Introduction
Introduction
Related Work
• Data Transmission in a WSN
Problem Definition
Problem Definition
Problem Definition
Problem Definition
Finding Network Frequencies
• Theoretical Foundation
Finding Network Frequencies
• Theoretical Foundation
Finding Network Frequencies
• Theoretical Foundation
Finding Network Frequencies
• Theoretical Foundation
Finding Network Frequencies
• Theoretical Foundation
Finding Network Frequencies
• Algorithm
Finding Network Frequencies
• Algorithm
Finding Network Frequencies
• Algorithm
Experimental Evaluation
Experimental Evaluation
Experimental Evaluation
Conclusions
• This paper presents a novel framework that
allows sensors to sample at different rates, while
ensuring timely routing of packets. We focus on
two versions of the problem, depending on
whether the WSN topology is fixed or not.
• Using real and synthetic datasets, demonstrate
the effectiveness of local synchronization in both
versions.