LI-FI =light fidality,that acceses most fater than WI-fi

2. What is LI-FI?
Light-Fidelity
LI-FI is transmission of data through
illumination, sending data through a
LED light bulb that varies intensity
faster than human eye can follow.

3. HISTORY OF LI-FI
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 Hass
continue to wow the world with the potential to
use light for communication.
prof.Harald Hass
University of Edinburgh

4. PRESENT SCENARIO
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.

5. Who can replace radio waves
for wireless communication?

7. HOW LIFI WORKS?
Operational procedure is very simple.
If LED is ON,digital data ‘1’ is transmitted &
if LED is OFF, digital data ‘0’ is transmitted.
LEDs varies in intensity so fast that a
human eye cannot detect it.
A controller connected at the back side of
these LED’s is used to code data.
Also called as 5G optical optical
communication.

8. IMPLEMENTATION
All the data from internet is
Streamed into lamp driver.
Data from internet is used to
modulate the intensity of LED
light source.
Thus by fast and subtle variations
of current,optical output can be
made to vary at high speed.
The photodetector picks up
the signal
The receiver dongle then converts
the tiny changes in amplitude into a data stream.

10. Radio
waves
Infrared
rays
Visible
rays
X-Rays
Gama
rays
WHY ONLY VLC
Gama rays can’t be used as they could be
dangerous
X-rays have similar health issues.
Ultraviolet light is good for place without
people, but otherwise dangerous for the
human body.
Infrared,due to eye safety regulation,can
only be used with low power.

15. LIMITATIONS
Visible light cannot penetrate through solid
objects.
A major challenge of LIFI is how the
receiving device will transmit back to
transmittor.
Interferences from external light sources like
sunlight,in the path of transmission will cause
interruption in the communication.
Data transmission can be easily blocked by
any object placed in front of LED source.

16. CONCLUSION
Thus ,if LI-FI technology can be put into
practical use,every bulb can be used as an
alternative to Wi-Fi hotspots. It provides
simple,faster and efficient wireless data
communication.Li-Fi will make us to proceed
towards the cleaner,greener,safer and brighter
future.