slide show gives u basic description on li-fi technology

1. A SEMINAR ON
LI-FI TECHNOLOGY
BY
K.SAI PHANINDRA
ECE-II YEAR

2.  The technology truly began in
1990’s in countries like
german,korea and japan where
they discovered led’s could be
retrofitted to send and receive
information.
 Professor “harald hass” from the
university of Edinburgh coined
the term Li-Fi in the TED global
talk in 2011.
 He continues to wow the world
with his potential to use the light
for communication.

3. 1.4 billion 5 billion

4. DISADVANTAGES OF OTHER SPECTRUMS
OVER Li-Fi
Radio
waves
Infrared
waves
Visible
spectrum
Ultraviolet X-rays Gamma rays
Insufficient
spectrum for
increasing data
Low power
application
Its not
even used
so far
Dangerous for
human body
and hence cannot
be used
Used for
hospitals
Its not used
for general
purposes

5. WHAT CAN REPLACE THE
RADIO WAVES WIRELESS
COMMUNICATION ???

7. WHAT IS LI-FI TECHNOLOGY ?
 The term li-fi stands for light fidelity.
 The term was coined by Harald hass.
 It is a bidirectional-high speed and fully networked wireless
communication technology similar to wi-fi.
 It is a form of visible light communication and could be used
in (owc).
 Instead of wi-fi modems li-fi uses transceiver fitted led lamps
to light room and also transmit data.
 It could also be said as the transmission or illumination of
data through led which varies intensity faster than a human
eye can follow.

8. HOW DOESTHE Li-FiWORKS?
■ Both the li-fi and wi-fi are similar in transmitting data but they are
different on which medium they transmit the data.
■ Li-fi uses light and wi-fi uses radio waves but the speeds and range varies
accordingly.
■ The led’s that are used in the Li-Fi could be turned on and off very easily so
that it could be a nice opportunity to transfer the data in the form of binary
code.
■ Switching on an led is logical 1 and switching of and led is logical 0.
■ Hence it is possible to encode the data into the led’s by using a controller
,we just have to vary at which led’s flicker depending on the data we want
to encode to give different strings of 0’s and 1’s.
■ According to the uk reasearchers say that they were able to achieve a
speed of 10GBPS using the Li-Fi technology.

9. MAIN COMPONENTS OF A LI-FI COMMUNICATION SYSTEM
High brightness white led which
acts as communication source
A silicon photodiode which
shows good response to visible
wavelength region serves as
the receiving element.

10. DIFFERENCES BETWEEN TECHNOLOGIES

12. APPLICATIONS OF Li-Fi

13. IN AIRCRAFT CABINS
• Whenever we travel through
airways we face the problem in
communicationMedia because
the whole airways
communication is based on the
radio waves.
• To overcome this backdraw on
the radio waves Li-Fi could be
introduced.

16. ADVANTAGES
Large bandwidth
Efficiency
High security
Easy to use
Fast data transfer
Harmless
Low-cost
Capacity

17. DISADVANTAGES
•LIGHT CANNOT PASS THROUGH OBJECTS.
•A MAJOR CHALLENGE THAT LI-FI IS FACING IS THAT
HOW THE RECEIVING DEVICE WILL TRANSMIT DATA
BACK TO TRANSMITTER.
•INTERFERENCE FROM EXTERNAL LIGHT SOURCES LIKE
SUN, LIGHT, NORMAL BULBS & OPAQUE MATERIALS.

19. The Possiblities are numerous and can be explored
further.
Inspite of its disadvantages if this technology can be put
into practical use,every bulb can be used something like
a wifi hotspot to transmit data wireless and will proceed
towards the cleaner,greener,safer environment and
future.