Transcript Smart Antenna Technologies - Georgia Institute of Technology

Enhancement of IPTV using a
Wireless Sensor Network
Sandeep Kakumanu,Sriram Lakshmanan,
and Raghupathy Sivakumar
GNAN Research Group
Georgia Institute of Technology
IPTV-Introduction
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Packet based transmission of television streams
using the Internet Protocol
Envisaged Advantages (over conventional TV):
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On demand channel access permits bandwidth to be
utilized entirely for active channels
High levels of user interaction
Viewable channels not limited by either geographical
location
Number of channels not limited by access link
bandwidth
Video sources not restricted to high end content
providers enabling larger variety and diversity of
channels
Allows integration with the Internet
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IPTV Architecture
Satellite
content
IPTV
Subscribers
Local content
Off air content
Encoders
Local Headend
Private/Public wired network
VOD server
Ad server
Internet
Video servers
IPTV Architectures
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Classification based on connection nature
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Unicast
Multicast
Classification based on communication
infrastructure
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Model 1: Public internet with no provisioning
Model 2: Public internet with service provisioning
Model 3: Private IP Network
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Challenges
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Loss rate
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Channel switching latency
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Bandwidth constraints lead to high and varying loss
rates
The acceptable loss rate for television < 1% *
Delays from server to client (due to potentially large
geographical separation)
On-demand nature also incurs stream stop, setup
delays
Acceptable channel switching latency < 1s *
Management of large number of subscribers
*[Source:Gartner Research Report , 2005]
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WSN Enhancement 1: Quality
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Principle
“What you see is what you fetch”
 In cases where there is no active user but the
television is on, such streams can be communicated
at low priority, low data rate or even paused.
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Realization
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The Wireless Sensor network senses user
presence/absence.
A combination of light sensors mounted on the chair
and accelerometers to detect cushion deformation is
used to determine user presence/absence.
Multimedia stream control is done based on sensor
values.
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WSN Enhancement 2:Pre-fetching
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Principle
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“Fetch possible next channel(s) just before the user
switches”
Pre-fetching is a powerful technique that can be used
to reduce the user perceived channel switching
latency.
Realization
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The WSN at the user premises can be used to provide
real time feedback about when to pre-fetch and when
not based on
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The motion of the remote control
Accelerometers used to detect motion of remote
control.
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WSN Enhancement 3:Targeted Advertising
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Principle
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One of the goals of IPTV is to provide user-specific
and relevant content
Targeted Advertising (user relevant advertisements) is
a unique possibility of IPTV
Realization
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A WSN enables collecting information about the user
on which the targeted advertising decisions can be
based
The ambient conditions of the room or the
environment around can be used
Use temperature, humidity, pressure, light sensors
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TESTBED SETUP
VLC Server
192.168.1.11
Network
Nightmare
192.168.1.101
WLAN router
192.168.1.1
LCD Monitor
LCD Monitor
Viewer
STB/Laptop
STB/Laptop
192.168.1.12
192.168.1.14
Viewer
Sink
Sensors
192.168.1.100
Sensors
Future Work
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Optimize the code at both the IPTV software and
the Sensor Network software for minimum
possible reaction times
Modify the medium access scheme of the sensor
network for reduced delay
Explore use of WSN for IPTV over wireless.
Design algorithms for cases where each house
has several televisions.
Design algorithms for unicast and multicast load
balancing using sensed data
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