Li-Fi is a new wireless technology which provides the connectivity within localized network environment. The main principle of this technology is we can transmit the data using light illumination by using light emitting diodes where radio frequency is media in Wi-Fi and LED bulb light intensity is faster than human eye can follow. One germen phycist-Prof Harald Haas an expert in optical wireless communications at the University of Edinburgh, he demonstrated how an LED bulb equipped with signal processing technology could stream a high-definition video to a computer. By using this technology a 1 watt LED light bulb would be enough to provide net connectivity to four computers. This technology termed as "light fidelity". This technology allows us to transfer data more securely with higher data rates. This technology is still under research and further exploitation could lead to wide applications.
3. INTRODUCTION
Li-Fi means light fidelity.
It can be used as light based Wi-Fi.
Instead of radio waves it uses visible rays for transmission.
Data can be transmitted through LED light.
4. LITERATURE REVIEW
Professor Harald Haas
from the University of
Edinburgh coined the
term Li-Fi in TED global
talk in 2011.
Harald Haas continues to
wow the world with the
potential to use light for
communication.
Prof.Harald Haas
5. BASIC CONCEPT
 The on-off activity of LEDs enables a kind of data
transmission using binary codes.
 Switching on an LED is a logical ‘1’;switching it off is
a logical ‘0’.
 A light sensitive device (photo detector) receives the
signal and converts it back into original data.
8. DISADVANTAGES OF OTHER SPECTRUMS
Insuffient
spectrum for
increasing
data
Low power
application
Which is
not used
so far.
Dangerous
for human
body
Used for
hospitals
It is not
used
generally
10. ï‚¢ Cost and Expensive
ï‚¢ Less Bandwidth compared to other spectrums
ï‚¢ Insufficient spectrum for increasing data
11. ï‚¢ Millions of base stations consume huge amount of
energy for
1.Transmitting the radio waves
2.To cool the base station cabins
ï‚¢ 5% Efficiency
12. ï‚¢ Available within the range of Base stations
ï‚¢ Limited availabity
ï‚¢ Unavailable in aircrafts
ï‚¢ Less secure(passes through the walls)
13.  Larger bandwidth (10,000 times the radio
bandwidth)
 High efficiency
 More availability
 NOT Harmful
 Highly secure
14. DISADVANTAGES
Light can’t pass through objects.
 Presence of Light is essential.
There will be interference from sunlight.
 You need special LEDs.
High installation cost of the VLC systems.
19. CONCLUSION
Overcomes the limitations of radio spectrum.
High speed of 10 Gbps can be achieved.
Li-fi can solve the for essential problems of wireless
communications these days.
20. REFERENCES
[1] RECENT ADVANCEMENTS IN LI-FI TECHNOLOGY
AKSHATA M SONNAD, ANJANA GOPAN, 3SAILAKSHMI N R, DIVYA S,
AMBIKA R BMSIT
[2] A SURVEY ON TRANSMISSION OF DATA THROUGH ILLUMINATION -
LI-FI
M. MUTTHAMMA ,ASSISTANT PROFESSOR, DEPARTMENT OF ECE, GCET,
HYDERABAD, A.P., INDIA
[3] LI-FI (LIGHT FIDELITY) TECHNOLOGY
U.SUGANYA1, C.SUBHALAKSHMIPRIYA
[4] LI-FI TECHNOLOGY:TRANSMISSION OF DATA THROUGH LIGHT
RAHUL R. SHARMA, RAUNAK, AKSHAY SANGANAL