Fast and Quality-Guaranteed Data Streaming in Resource-Constrained Wireless Networks

Speaker:	Professor Kui WU
		Department of Computer Science
		University of Victoria
		Canada

Title: 		"Fast and Quality-Guaranteed Data Streaming in
		 Resource-Constrained Wireless Networks"

Date:		Monday, 26 May 2008

Time:		4:00pm -5:00pm

Venue:		Lecture Theater H
		Chen Kuan Cheng Forum, near lifts 27/28, HKUST

Abstract:

In many emerging applications, data streams are monitored in a network
environment. Due to limited communication bandwidth and other resource
constraints, a critical and practical demand is to online compress data
streams continuously with quality guarantee. Although many data
compression and digital signal processing methods have been developed to
reduce data volume, their super-linear time and more-than-constant space
complexity prevents them from being applied directly on data streams,
particularly over resource-constrained wireless networks, e.g., wireless
sensor networks, or low-speed, low-power wireless personal area networks
(WPAN). We tackle the problem of online quality guaranteed compression of
data streams using fast linear approximation (i.e., using line segments to
approximate a time series). Technically, we address two versions of the
problem which explore quality guarantees in different forms. We develop
online algorithms with linear time complexity and constant cost in space.
Our algorithms are optimal in the sense they generate the minimum number
of segments that approximate a time series with the required quality
guarantee, even without knowing future in-coming data. To meet the
resource constraints, we also develop a fast algorithm which creates
connecting segments with very simple computation. The low cost nature of
our methods leads to a unique edge on the applications of massive and fast
streaming environment, low bandwidth networks, and heavily constrained
nodes in computational power. We implement and evaluate our methods in the
application of an acoustic wireless sensor network.


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Biography:

Kui Wu received BSc. and Master's degrees from Wuhan University, China and
the Ph.D degree from the University of Alberta, Canada. He joined the
Department of Computer Science, University of Victoria, Canada, in 2002,
where he is currently a tenured Associate Professor. His research
interests include mobile and wireless networks, sensor networks, network
performance evaluation, and network security.