2. Whether we are using free WIFI provided by our College or stealing
from a friend next door , we probably feel frustrated at the slow speeds
we face . As more and more people and their devices access wifi or
wireless internet, clogged airwaves are going to make it increasingly
difficult to latch onto a reliable signal. But radio waves are just one
part of the spectrum that can carry our data.
What if we could use other waves to surf the internet ???
One German physicist Dr. Harald Haas , has come up with a solution
called “ Li-Fi or Light Fedility ”
He calls it “ Data Through Illumination ”- sending data through a LED
bulb . It is very much same as infrared remote control, but very much
powerful than that.
3. Introduction
Light Fidelity
Need For Li- Fi
Life Of Li- Fi
How It Works
Advantage
Limitation
Conclusion
Reference
3Anjeet Kumar, CSE 6th SEM
4. In simple terms, Li-Fi can be thought of as a light-based Wi-Fi. That is, it uses light
instead of radio waves to transmit information. And instead of Wi-Fi modems, Li-
Fi would use transceiver-fitted LED lamps that can light a room as well as transmit
and receive information. Since simple light bulbs are used, there can technically be
any number of access points.
Li-Fi is a VLC, visible light communication, technology developed by a team of
scientists including Dr Gordon Povey, Prof. Harald Haas and Dr Mostafa Afgani at
the University of Edinburgh. The term Li-Fi was coined by Prof. Haas when he
amazed people by streaming high-definition video from a standard LED lamp, at
TED Global in July 2011. Li-Fi is now part of the Visible Light Communications
(VLC) PAN IEEE 802.15.7 standard. “Li-Fi is typically implemented using white LED
light bulbs. These devices are normally used for illumination by applying a constant
current through the LED
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6. What is Li - Fi ?????
Light based WI-FI
Light is used instead of radio-waves to transmit
information
Transceiver fitted LED lamps acts like Wi-Fi modems
LED lamps can light a room as well as transmit-receive
information
Provides illumination as well as data communication
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7. Radio spectrum is congested, but
the demand for wireless data
doubles each year
Issues regarding radio spectrum,
such as capacity, availability,
efficiency, security are solved
using LIFI.
Speed of data transmission can be
increased.
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8. Introduced by Professor Herald hass, at the university of
Edinburgh.
Established in 2011 TED global talk
The promotion of idea through TED helped to start a company,
Pure LiFi
Pure LiFi, formerly pure VLC, is an original equipment
manufacture firm setup to commercialize Li-Fi products for
integration with existing LED lighting systems
In October 2011, few companies and industries group formed
Li-Fi consortium to promote the high speed optical wireless
systems
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9. Operational procedure is very simple.
If LED is ON, digital data ‘1’ is transmitted & if LED is
OFF, digital data ‘0’ is transmitted.
LEDs varies in intensity so fast that a human eye cannot
detect it
A controller connected at the back side of these LEDs is
used to code data.
Also called as 5G optical communication.
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11. All the data from Internet is streamed into lamp driver.
Data from internet is used to modulate the intensity of LED light
source.
Thus by fast and subtle variations of current, optical output can
be made to vary at extremely high speed
The photodetector picks up the signal
The receiver dongle then converts the tiny changes in amplitude
into a data stream.
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13. LIFI can be used in
sensitive areas such as aircrafts for data transmission
without causing interference
Places where it is difficult to lay optical fibers like operation
theaters
Traffic scenarios, thereby reducing accidents
Underwater applications where radio waves cannot
propagate.
Industries like petrochemical plants, nuclear power plants ,
petrol pumps etc
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14. In home and small offices, Li-Fi can be used to communicate with
devices like
Laptops
Internet access
HD video streaming
Printer
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15. In traffic scenario, LIFI can be used
to communicate with the LED lights of
cars .
Cars can have LED-based
headlights, backlights and can
communicate with each other.
This might prevent accidents, by
exchanging information, when the
vehicles are too close
Using LIFI, Street lights can be used
to send information about the road
condition to the car.
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16. The first VLC Smartphone was
presented by Consumer Electronics in
January, 2014
The phone uses Wysips connect – a
clear thin layer of crystal glass is
added to the small screens
Smartphone makes them solar
powered.
Smartphone could get 15% more
battery life in a day
Can communicate using Li-Fi.
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17. Data rate greater than 10 Gbps; Theoretically allowing HD film
to be downloaded in 30 seconds
Can be used anywhere, even in RF restricted areas; Since light
waves will not interfere with radio waves.
Mostly LED light bulbs are used, which consumes less energy.
Hence cost efficient.
As light waves cannot penetrate through walls, the data cannot
be intercepted; Thus provides secured communication.
Efficient alternative to radio based wireless; since it is quick
and reliable.
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18. Visible light cannot penetrate through solid objects.
A major challenge of LiFi is how the receiving device will
transmit back to transmitter.
Interferences from external light sources like sunlight, in the
path of transmission will cause interruption in the
communication.
Data transmission can be easily blocked by any object placed in
front of LED source.
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19. Thus, if Li-Fi technology can be put into practical use, every
bulb can be used as an alternative to Wi-Fi hotspots. It provides
simple, faster and efficient wireless data communication. Li-Fi
will make us to proceed towards the cleaner, greener, safer and
brighter future.
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20. GOOGLE .
WIKIPEDIA .
Our Teachers .
www.lificonsortium.org
www.studymafia.com
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