This document provides an introduction and overview of Li-Fi technology. It begins with a brief history of networking technologies including wired networks, wireless networks like Wi-Fi, and the more recent introduction of Li-Fi by Dr. Harald Haas in 2011. It then discusses some issues with current radio-based wireless communication technologies like limited availability and bandwidth. Li-Fi is introduced as a new wireless communication technology that uses visible light communication and LED bulbs to transmit data at speeds over 10Gbps. The key components and workings of Li-Fi are explained along with advantages over traditional wireless networks like larger bandwidth, security, and energy efficiency. The document concludes that Li-Fi has promising applications and possibilities if developed further.

1. IL
FI
TEC
OGY
NOL
H
By
A.Rejoice Anton
&
V.Prem Kumar
II Year – CSE Department
Vaigai College of Engineering
Madurai

2. INTRODUCTION
Internet services are very highly demanding and essential
accessories in current situation. Presently we are utilizing the
wired networks and mostly wireless networks like Wi-Fi in our
houses, offices, shops, hotels, college campus and around 10-100
meter distances to connect our P.C., Laptops, mobile phones.
As present paper tells about the newly introduced Li-Fi technology
network which is based the visible light communication that
provide a fast data speed about greater than 10 Gbps.

3. HISTORY OF NETWORKS

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In the olden days, People formed a network in order to transmit
a piece of data from one place to another.
With the advances in technology a new networking was
developed using wires as a medium ( wired networking ).
As time passed the technology increased and we launched
satellites into space and thus were in a position to transmit
enormous amount of data across various geographical location.
W
ireless networking gained a wide recognition and become the
most popular of all networks ( example ): Wi-Fi.
As technology keep on developing , the latest wireless network
LI-FI is introduced to overcome disadvantages of radio
frequency communication.

4. PRESENT WIRELESS COMMUNICATION
PRESENT WORLD
5 Billion
1.4 Million

5. ISSUES REGARDING RADIO-SPECTRUM
Radio Spectrum is congested but the demand for wireless
data double each year. Everything, it seems want to use
wireless data but the capacity is drying up.
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Available within the range of Base stations
Limited availability
Unavailable in aircrafts
Less secure (passes through the walls)
Cost and Expensive
Less bandwidth compared to other spectrums
Harmful to humans health

6. WHAT IS LI-FI ?
LI-FI ( Light-Fidelity ) is transmission of data
through illumination ,sending data through a LED
light bulb that varies in intensity faster than human
eye can follow.

8. HISTORY OF LI-FI
A German Physicist, Dr.Harald
Haas a professor in university of
Eddinburgh who began his
research in the field in year 2004.
 In 12th July 2011,He first introduced
to the world this new technology Li-Fi
in TED Global conference in
Eddinburgh UK.

Harald Haas

9. TED GLOBAL CONFERENCE

10. HOW LI-FI WORKS ?
 The
operation procedure is very simple, if the
LED is on, you transmit a digital 1, if it's off you
transmit a digital 0.
 They can be switched on and off very quickly,
which gives nice opportunities for transmitting
data.

11. The main components of this communication systems are
 A high
brightness white LED, Which act as a
communication source.
 A silicon photodiode which shows good response to
visible wavelength region serving as the receiving
element.
Transmitting element
Receiving element

13. VISIBLE LIGHT COMMUNICATION

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Visible light communication ( VLC ) is a potential solution to the global
wireless spectrum shortage.
Li-Fi technology is based on Visible Light communication.
VLC is a data communication medium, which uses visible light between
400 THz and 800THz as optical carrier for data transmission and
illumination.
It uses fast pulses of light to transmit information wirelessly.

14. WHY ONLY VLC?

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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.
HENCE WE LEFT WITH THE ONLY THE VISIBLE – LIGHT SPECTRUM.

15. DIFFERENCE BETWEEN TECHNOLOGIES

16. PP
A
S
A
IC
L
N
IO
T

17. RF RESTRICTED

18. AIRCRAFT

19. APPLICATIONS
TRAFFIC

20. PUBLIC INTERNET

22. ADVANTAGES ….
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Larger bandwidth ( 10,000 times the radio bandwidth )
High speed data rate
High efficiency
Highly secure
Works even under water in sea
Safe for health
More availability
Low cost solution

23. GE
TtiA’’
Nsen al
A
Vht is Es
AeD Lig
I S nc of
D
Prese
“

24. CONCLUSION
The possibilities are numerous and can be explored further.
If this technology can be put into practical use, every bulb can
be used as Li-Fi access point to transmit wireless data and
we will proceed toward the cleaner, greener, safer &
brighter future !
This may solve issues such as the shortage of radio
frequency bandwidth and also internet where radio based
wireless isn’t allowed such as aircraft, Hospitals, etc…

25. REFERENCES
Google
 Wikipedia
 Lifeconsortium.org
 Newtecarticles.com
 Seminarprojects.com
 Irjcjournals.org
 extremetech.com


26. THANK YOU ALL