1. SUJEET KUMAR
10 SEP, 2013
A N COLLEGE, PATNA

2. Contents
Li-Fi Definition
History
Present scenario
Li-Fi Working Process
Difference between technologies
VLC
Advantage of Li-Fi
Conclusion

3. What is Li – Fi ?
• The term Li-Fi is increasingly being used to refer to
the use of Visible Light Communication (VLC)
technology in wireless computer networking.
• LI-FI is transmission of data through illumination
,sending data through a LED light bulb that varies
in intensity faster than human eye can follow

4. 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.
HARALD HASS

5. Present Scenario
1.4 Million
5 Billion

6. Present Scenario
• Radio Spectrum is congested but the
demand for wireless data is increasing
day by day. Every one want to use
wireless data but the capacity is drying
up.
• So what should we do to carry this excess
demand in the future .

9. How LI-FI Works ?
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.
As soon as, LED starts glowing, photo detector or
light sensor on other end will detect light and get a
binary 1 otherwise binary 0.
Light emitting diodes can be switched on or off faster
than the human eye can detect, causing the light source
to appear to be on continuously.

12. Difference Between The Technologies

13. 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.
HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT SPECTRUM.

14. 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.

15. Advantages of Li-Fi
• Best advantage of Li-Fi Technology
will be accessing internet at high
speed in those areas where optical
fires are not easy to install.
• It has wide area availability
• Harmlessness

16. 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.