This document discusses Li-Fi technology, which uses visible light communication to transmit data wirelessly using LED light bulbs. It provides an introduction to networks and issues with current radio-frequency technologies. Li-Fi uses light-emitting diodes that can be flickered on and off quickly to transmit digital 1s and 0s. It has advantages over Wi-Fi like higher speed, larger bandwidth, and it is safe for health. Potential applications of Li-Fi include use on airplanes and in traffic lights.

1. Presented By:- Krupa Shingala

2.  Introduction
 History Of Network
 Drawbacks Of Before Technologies
 Why Only VLC?
 What is VLC?
 What is Li-fi?
 Working process
 Applications
 Advantages & Disadvantages
 Conclusion
Content

3. 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.

4. HISTORY OF NETWORKS
 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.
 Wireless 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.

5. Drawbacks Of Before
Technologies Radio spectrum
 1.4 Million base stations, 5 billion Mobile stations
 600tb data every per month

6. 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.
 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

7.  Single data stream
 10,000 or 20,000 bits per second
 Not usable for video streaming

8.  CAN IT BE GAMMA RAYS ? NO
 CAN IT BE X-RAYS ? NO  X-RAYS HAVE SIMILAR HEALTH ISSUES
 CAN IT BE UV RAYS? NO
why only VLC
 CAN IT BE INFRARED WAVES ? NO  INFRARED, DUE TO EYE SAFETY
REGULATION, CAN ONLY BE USED
WITH LOW POWER.
HENCE WE ARE LEFT WITH ONLY THE VISIBLE - LIGHT SPECTRUM.
 GAMMA RAYS ARE RADIOACTIVE AND
DANGEROUS FOR HEALTH.
 UV RAYS ARE HARMFUL FOR OUR
SKIN AND CANNOT BE USED FOR
LONG DURATION

9.  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.
VISIBLE LIGHT
COMMUNICATION

10. What Is Li-Fi???
 Li-Fi means “Light Fidelity”.
 At the heart of this technology is a new generation of
high brightness light-emitting diodes.
 It is possible to encode data in the light by varying the
rate at which the LEDs flicker on and off to give
different strings of 1s and 0s.

11.  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.
 German Physicist, Dr.Harald Haas a professor in
university of Eddinburgh who began his research
in the field in year 2004.
Harald Haas

12.  Light power(LED)
 Multiple data streamHigh speed

13. 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.

14. 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

15.  The functioning of new Li-Fi technology is just simple. You will have
a light source at one end like a LED and a photo detector (Light
Sensor) on the other end.

16. A Li-Fi Environment

18. AIRCRAFT CABINS
 Used in airlines: Generally in airlines mobile phones can’t be used
as they can effect the radars which are main way of communication.

19. TRAFFIC SYSTEM
 Used in traffic lights which can communicate with cars to avoid
accidents.

20. PUBLIC INTERNET HOTSPOT
Street lamps(as free access points)

21. ADVANTAGES ….
 Larger bandwidth ( 10,000 times the radio bandwidth )
 High speed data rate
 High efficiency
 Highly secure
 Safe for health
 More availability
 Low cost solution

23. 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…

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