Li-Fi is a wireless communication technology that uses light from LED bulbs to transmit data. It was invented in 2011 by Professor Harald Haas at the University of Edinburgh. Li-Fi works by varying the intensity of LED light faster than the human eye can detect to transmit digital 1s and 0s. It provides wireless connectivity using visible light that has a higher speed than Wi-Fi and does not interfere with radio frequencies. While Li-Fi has advantages over Wi-Fi such as higher speed and capacity, it also faces challenges of being interrupted by obstacles that block light and inability to work while on the move.

1. Presented by- Pratik Dave

2. History of Networks
In the olden days.
Wired networking.
Satellites Communications.
Wireless networking.

3. GENESIS OF Li-fi
Harald Hass, a professor at the University of Edinburgh who
began his research in the field in 2004, gave a debut
demonstration of what he called a Li-Fi prototype at the
TEDGlobal conference in Edinburgh on 12th July 2011.

4. What is li-fi?
• 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.
• This varies in intensity faster than human eye can follow.
• It is the fast and cheap wireless communication system which is
optical which is optical version of the Wi-Fi.

5. How LI-FI Works ?
 operational 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.

6. Architecture OF Li-Fi

9. Concept -:
 operational procedure is very simple
 if the LED is ON, you transmit a digital 1’s
if its OFF you transmit a 0’s.
The LEDs can be switched ON and OFF very quickly,
which gives nice opportunities for transmitting data.

10. 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 bse used with low power.

11. For giga-speed technologies, the Li-Fi Consortium defined
GigaShower, GigaSpot and GigaMIMO models

13. • LI-FI HAS AN UPPERHAND DUE TO PARALLEL DATA
TRANSMISSION.

14. LI-FI VS WIFI (CONTD…)
PART OF EM SPECTRUM THEY
USE
• LI-FI USES THE VISBLE
LIGHT PORTION OF
THE EM SPECTRUM
• WIFI USE THE
RADIOWAVE
PORTION OF THE EM
SPECTRUM

15. ISSUES WITH RADIO WAVE
 CAPACITY
• WITH THE ADVENT OF NEW TECHNOLOGIES LIKE 3G ,4G WE ARE
RUNNING OUT OF SPECTRUM.
• THAT’S WHY RADIO WAVES ARE NOW BECOMING EXPENSIVE.

20. DE-MERITS
• light can't pass through objects
• Connectivity while moving
• Interferences from external light sources like
sun light, normal bulbs, and opaque materials
in the path of transmission will cause
interruption in the communication.

21. CONCLUSION
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.