Light Fidelity

1. LIGHT FIDELITY
Sharib Shams (11000213020)
Ayub Khan (11000213006)
Reneta Basu (11000213015)
Saddam Hussain (11000213017)
Anupam Mandal (11000213003)
Suvadeep Ghosh (11000214036)
Government College of Engineering & Textile Technology,Serampore
Li-Fi
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2. Acknowledgement
We take this opportunity to express our profound gratitude and deep
regards to our faculty Prof Tapan Mandal & Prof Prasun Haldar for their
exemplary guidance, monitoring and constant encouragement throughout
the course of this project. The blessing, help and guidance given by them
time to time shall carry us a long way in the journey of life on which we are
about to embark.
We are obliged to our project team members for the valuable
information provided by them in their respective fields. We are grateful for
their cooperation during the period of my assignment.
• SHARIB SHAMS
• AYUB KHAN
• RENETA BASU
• SADDAM HUSSAIN
• ANUPAM MONDAL
• SUVADEEP GHOSH 2

3. Contents
• Introduction
• History
• Present Scenario
• Radio Spectrum and issues
• VLC & the best possible alternative
• Working
• Comparative study of Li-Fi and Wi-Fi
• Disadvantages
• Applications
• Ideas for more applications of this technology
• References
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4. • A new era in wireless communication is
soon going to hit the world.
• A German physicist, Herald Hass who
evolved a method to transfer data through
illumination which he called it as D-light
(or Li-Fi).
•Li-Fi is a very advanced version of Wi-Fi
basically “light fidelity” which uses visible
light communication instead of radio wave
communication as in Wi-Fi.
•As speed of light is way faster than radio
waves hence it can be used with a speed
of around 250 times more than any high
speed broadband.
Introduction
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5. History
• The technology truly began
during the 1990's in countries
like Germany, Korea, and
Japan where they discovered
LED's could be retrofitted to
send information.
• Harald Haas continues to
wow the world with the
potential to use light for
communication . Prof. Harald Haas
University of Edinburgh.
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6. Real Time Usage of Li-Fi
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7. Present Scenario
 Radio Spectrum is congested but the demand for wireless data
double each year .Every thing, it seems want to use wireless
data but the capacity is drying up.
1.4 Million Base Stations 5 Billion
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8. Radio Spectrum
Concerns regarding Radio Spectrum…..
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9. Radio Spectrum Issues
 Capacity
 Less Bandwidth compared to other
spectrums
 Insufficient spectrum for increasing
data
 Millions of base stations consume
huge amount of energy for
1.Transmitting the radio waves
2.To cool the base station cabins
 5% Efficiency
 Efficiency
Availability
 Available within the range of Base
stations
 Limited availability
 Unavailable in aircrafts
 Security
 Less secure (passes through the walls)
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11. HENCE WE ARE LEFT WITH ONLY THE VISIBLE - LIGHT
COMMUNICATION
Why only VLC ?
Radio
Waves
Infrared
Rays
Visible
Rays
Ultraviolet
Rays
X- Rays Gama
Rays
 Gama rays cant be used as they could be dangerous.
 X-rays have similar health issues.
 Ultraviolet light is good for place without people, but
other wise dangerous for the human body.
 Infrared, due to eye safety regulation, can only be used
with low power.
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13. How Li-Fi Works
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14. Working (contd..)
• The functioning of Li-Fi is simple, yet
amazing. You just needs two thing,
first is LED (which acts as a light
source) and other is photo detector (a
light sensor for capturing light).
• When light source starts to emit light,
light sensor on other end will detects it
and get a binary 1 otherwise binary 0.
• LED flashes certain time and builds up
a message. Light censor detects the
light flashing of light and receives the
message.
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15.  Li-Fi can be thought of as a light-based Wi-Fi. That is, it uses
light instead of radio waves to transmit information.
 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.
 WI-FI is great for general wireless coverage within buildings,
and li-fi is ideal for high density wireless data coverage in
confined area and for relieving radio interference issues .
 So the two technologies can be considered complimentary.
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18. Application Areas
Intrinsically Safe Environment :
Visible Light is more safe than RF, hence it can be used in places
where RF can't be used such as petrochemical plants .
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19. • Safety and management: it can be used to update traffic
information at almost every instant and it will be easy for
traffic police to deal with traffic and catch the one who
breaks the rule.
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20. • Health sector: Since WIFI is not safe to be used in
hospitals and other various health care sectors
because it penetrates human body. Li-Fi can be
implemented and well suit in this sector.
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21. • Underwater communications: Since radio waves cannot be used
under water because these waves are strongly absorbed by sea
water within feet of their transmission and this renders it unusable
underwater but Li-Fi is suitable for underwater communication .
• Li-fi opens endless opportunities for military and navigation
operations.
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22. Airlines : Whenever we travel through airways we face the
problem in communication media ,because the whole
airways communication are performed on the basis of radio
waves. To overcome this drawback on radioways , Li-Fi is
introduced.
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23. • Internet anywhere: street lamps, light of vehicles can be used to
access internet anywhere in footpaths, roads, malls, anywhere
where light source is available.
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24. • Radio waves are harmful for human beings as they penetrate the
body and may cause mutation. So it is safe.
• It is very secure (no-body can hack it,) since no signal penetration
through walls.
• Tremendous data transfer rates.
• It works under water, so it is beneficial in many fields.
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25. Nothing in this world is perfect and so does Li-Fi.
• These signals cannot penetrate walls. So the person needs
wired bulb in that room also.
• Only works if there is direct line of sight between source
and receiver.
• Used for broadcast and it is difficult to uplink.
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26. The possibilities are numerous and can
be explored further.
If this technology can be put into
practical use , every bulb can be used
something like a Wi-Fi hotspots to
transmit wireless data.
Though it is limited only upto a certain
specific region where the light
reaches, still its high speed and assured
security provides it an edge
over other technologies.
It is a low cost highly reliable
technology. 26

27. Gi-Fi or gigabit wireless refers to a wireless communication at
a data rate of more than one billion bits (gigabit) per second.
In 2008 researchers at the University of Melbourne demonstrated a
transceiver integrated on a single integrated circuit (chip) that operated at
60 GHz on the CMOS process.
It will allow wireless transfer of audio and video data at up to 5 gigabits
per second, ten times the current maximum wireless transfer rate, at one-
tenth the cost.
Researchers chose the 57–64 GHz unlicensed frequency band since the
millimeter-wave range of the spectrum allowed high component on-chip
integration as well as the integration of very small high gain arrays.
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28. REFERENCES
i. http://www.ijstr.org/final-print/oct2014/Li-fi-A-New-Era-Of-Wireless-
Communication-Data-Sharing.pdf
ii. https://www.youtube.com/watch?v=NaoSp4NpkGg
iii. http://en.wikipedia.org/wiki/Li-Fi
iv. www.ijacc.org
v. International Journal of advances in computing & communications
vol 1, by ‘Asoke Nath’ 2013
pp12
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