This document discusses LiFi technology, which transmits data through illumination using LED light bulbs. It was invented in 2012 by German physicist Harald Hass. LiFi works by switching LED lights on and off very quickly to transmit digital 1s and 0s. It provides wireless connectivity at speeds up to 1Gbps, faster than WiFi. Potential applications of LiFi include use in traffic lights, airplanes, and underwater communications since it does not interfere with radio frequencies. While it has advantages over WiFi like higher speeds and bandwidth, LiFi also has limitations such as requiring line of sight and being disrupted by external light sources.

1. LIFI TECHNOLOGY
B Y : - N I M E S H B A R I YA ( + 9 1 9 7 3 7 8 7 6 7 1 7 )

2. INTRODUCTION
LI FI- LIGHT FIDEALITY
Li-Fi is the transmission of data through
illumination, by taking the fiber out of fiber
optics by sending data through a LED light
bulb.It’s the same idea behind infrared remote
controls but far more powerful.

3. HISTORY
This technology was invented by
German Physicist “HARALD
HASS”, from the university of
Edinburgh, U.K.
He demonstrated it in the year
2012.
He explained Very simple, if the
LED is on, you transmit digital 1;if
it’s off you transmit a 0
.

4. PRESENT SCENARIO
1.4 Million 5 Billion
The demand for wireless data is double each year. Everything,
wants to use wireless data but the capacity is drying up.

5. So ,What can carry this excess demand in
this Future??

6. WHAT IS LIFI?
Li-Fi is the transmission of data through illumination
by taking the fiber out of fiber optics by sending data
through a LED light bulb.
The intensity of LED bulb varies Faster than human
eye can follow.
It is the fast and cheap wireless communication system
which is optical version of the Wi-Fi.

7. HOW LI-FI WORKS
Working procedure is very simple,if the led is
on, you transmit a digital 1, if its off you
transmit a 0. The LEDs can be switched on and
off very quickly, which gives nice opportunities
for transmitting data. Hence all that us required
is some LEDS and a controller that code data
into those LEDs.
We have to just vary the rate at which the LED’s
flicker depending upon the data we want to
encode.
Thus every light source will works as a hub for
data transmission.

8. HOW LI-FI WORKS..

9. HOW LI-FI WORKS..
On one end,all the data on the internet will be
streamed to a lamp driver when the led is turned
on the microchip converts the digital data in
form of light.
A light sensitive device (photo detector) receives
the signal and converts it back into original data.
This method of using rapid pulses of light to
transmit information wirelessly is technically
referred as Visible Light Communication.

10. WHY ONLY VLC??
VLC is a data communication medium, which uses the visible
light between 400 THz (780 nm) and 800 THz (375 nm) as optical
carrier for data transmission.

11. WHY ONLY VLC..??
Gamma rays are radioactive and are dangerous.
X-rays have similar health issues.
Ultraviolet light is good for place without people,but
other wise dangerous for the human body.
IR Waves are harmful for our eyes hence can’t be used.
Radio
Waves
Infrared
Rays
Visible
Rays
Ultraviolet
Rays
X- Rays
Gama
Rays

12. CONSTRUCTION OF LIFI
Li-Fi consists of 3 main primary assemblies:
1. Bulb
2. Power amplifier ciruit (PA)
3. Printed circuit Board(PCB)
4. Aluminum enclosure

13. CONSTRUCTION OF LIFI..
The PCB controls the electric inputs and outputs
of the lamp and houses the microcontroller used
to manage different lamp functions.
An RF (Radio-Frequency) signal is generated by
the solid-state PA and is guided into an
electronic field about the bulb.

14. CONSTRUCTION OF LIFI..
The high concentration of energy in the electric
field vaporizes the contents of the bulb to a
plasma state at the bulb’s center; this controlled
plasma generates an intense source of light.
All of these sub-assemblies are contained in an
aluminum enclosure.

15. COMPARISON BETWEEN LIFI AND OTHER TECHNOLOGY
Technology Speed Data density
Wireless
 Bluetooth 3Mbps *
 IrDA 4Mbps ***
 Wi-fi 150Mbps *
 Li-fi 1Gbps ****
 Giga-IR 1Gbps ***
 Wi-Gig 2Gbps **

16. APPLICATIONS AREAS
1.Traffic Areas:
 Traffic lights can communicate to
the car and with each other. Cars
have LED-based headlights, By using
this lights, the cars can communicate
with each other and prevent accidents
in by exchanging information.

17. APPLICATIONS AREAS..
2.RF Restricted Enviroment:
 Visible Light is more safe
than RF, hence it can be used in
places where RF can't be used
such as petrochemical plants .

18. APPLICATIONS AREAS..
3.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.

19. APPLICATIONS AREAS..
4.Underwater
communication:
 Li-Fi can even wok underwater
were Wi-Fi fails completely, thereby
its very much useful for
military/navigation operations.

20. ADVANTAGES OF LIFI
Li-Fi never gives side effect on any living thing.
It does not require any band width spectrum.
Any lightings device is performed as a hotspot.
Can be used underwater without radio
interference because salt conducts electricity.

21. DISADVANTAGES OF LIFI
 Presence of light is essential.
 There should be line of sight
 Works better with fluorescent light and LEDs but very
low efficiency with bulbs.
 Interferences from external light sources like sun light,
normal bulbs, and opaque materials in the path of
transmission will cause interruption in the
communication.
 High installation cost of the VLC systems.

22. CONCLUSION
 If this technology can be put into practical use , every bulb can be
used something like a Wi-Fi hotspots to transmit wireless data.

23. LIFI
ANY QUERIES??

24. LIFI
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