1. A SEMINAR ON:
LI-FI
LIGHT FIDELITY
Submitted by:
Sanjana Gupta
4GW11EC057
GSSS INSTITUTE OF ENGINEERING & TECHNOLOGY
FOR WOMEN
Mysuru– 570016
DEPARTMENT OF ELECTRONICS & COMMUNICATION
ENGINEERING
2014 – 2015
VISVESVARAYA TECHNOLOGICAL UNIVERSITY
BELAGAVI, KARNATAKA-570018
Under the Guidance of:
Mrs. Manjula G
Associate professor,
Dept. of ECE,
GSSSIETW

2. INTRODUCTION TO LI-FI
•LI-FI IS A TECHNOLOGY THAT USES THE
LIGHT EMITTING DIODES TO TRANSMIT THE
DATA WIRELESSLY.
•LI-FI IS FAST AND CHEAP OPTICAL VERSION
OF WI-FI ,BASED ON VISIBLE LIGHT
COMMUNICATION(VLC).
•VLC IS A DATA COMMUNICATION
MEDIUM,WHICH USES THE VISIBLE LIGHT
BETWEEN 400 THz (780 nm) and 800 THz (375 nm)
AS OPTICAL CARRIER FOR DATA
TRANSMISSION

3. Li-Fi can be thought of as a light-based
Wi-Fi. That is, it uses light instead of
radio waves to transmit information.
And instead of Wi-Fi modems, Li-Fi
would use transceiver-fitted LED lamps
that can light a room as well as transmit
and receive information.

4. Genesis of LI-FI
WHO INVENTED IT ?
This technology was invented
by German PHYSICIST
HARALD HAAS , from the
UNIVERSITY OF
EDINBURGH ,U.K , who
began his research in the field
in 2004, gave a debut
demonstration of what he
called a Li-Fi prototype at the
TED Global conference in
Edinburgh on 12th July 2011.

5. PRESENT SCENARIO
1.4 Million 5 Billion
Radio Spectrum is congested but the demand for
wireless data double each year .Every thing, it
seems want to use wireless data but the capacity
is drying up.

7. CAN IT BE INFRARED WAVES ? NO
IR WAVES ARE HARMFUL FOR OUR EYES HENCE
USED AT VERY LOW POWER
CAN IT BE UV RAYS? NO
UV RAYS ARE HARMFUL FOR OUR SKIN AND CANNOT BE USED
FOR LONG DURATION.
 CAN IT BE GAMMA RAYS ? NO
GAMMA RAYS ARE RADIOACTIVE AND ARE DANGEROUS.
 CAN IT BE X-RAY S ? NO
 SO WE ARE LEFT ONLY WITH VISIBLE
LIGHT SPECTRUM.

10. HOW DOES LI-FI WORKS?

11. •THE HEART OF THIS TECHNOLOGY IS A NEW
GENERATION HIGH BRIGHTNESS LED’S.
•THESE LED’S VARIES IN INTENSITY (THAT IS
GETS ON AND OFF) SO FAST THAT A HUMAN
EYE CANNOT DETECT IT.
•IF LED IS ON , THEN WE TRANSMIT A DIGITAL
SIGNAL 1,AND IF THE LED IS OFF , THEN WE
TRANSMIT A DIGITAL SIGNAL 0.
•A CONTROLLER IS CONNECTED AT THE BACK
SIDE OF THESE LED BULBS TO CODE DATA TO
THESE LED’S.

12. LI FI CONSTRUCTION
The LI FI product consists of 4 primary sub-
assemblies:
• Bulb
• RF power amplifier circuit (PA)
• Printed circuit board (PCB)
• Enclosure
3-The PCB controls the electrical inputs and outputs of the lamp
and houses the microcontroller used to manage different lamp
functions.
2- An RF (radio-frequency) signal is generated by the solid-state
PA and is guided into an electric field about the bulb. The high
concentration of energy in the electric field vaporizes the
contents of the bulb to a plasma state at the bulb’s center; this
controlled plasma generates an intense source of light. All of
these subassemblies are contained in an aluminum enclosure.

14. LIFI VS WIFI

15. Limitations 0r challenges-
# light can't pass through objects
# Interferences from external light sources
like sun light, normal bulbs, and opaque
materials in the path of transmission will
cause interruption in the communication.
#High installation cost of the VLC
systems.

17. POTENTIAL APPLICATION OF
LI-FI
Li Fi technology is still in its infancy .However some
areas where it seems perfectly applicable are:-
1. It will reduce your electricity bill and
maintenance bill

18. 2-INTRINSICALLY SAFE ENVIRONMENT
Visible Light is more safe than RF, hence it
can be used in places where RF can't be
used such as petrochemical plants .

19. 3- Airlines
Whenever we travel through airways we face the problem in
communication media ,because the whole airways
communication are performed on the basis of radio waves. To
overcomes this drawback on radio ways , li-fi is introduced.

20. 4- TRAFFIC LIGHTS
 Traffic lights can communicate to the car and with
each other. Cars have LED-based headlights, LED-
based cack lights, and cars can communicate with each
other and prevent accidents in by exchanging
information.

21. 5- PUBLIC INTERNET HOTSPOTS
There are millions of street lamps
deployed around the world.
Each of these street lamps could be a
free access point.

22. 6 – IN HOSPITALS

23. 7- ON OCEAN BEDS
Li-Fi can even wok underwater were Wi-Fi
fails completely, thereby throwing open
endless opportunities for military/navigation
operations.

24. 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.

25. REFERENCES
1. http://en.wikipedia.org/wiki/Li - Fi
2. www.lificonsortium.org/
3. Jyoti Rani, Prerna Chauhan, Ritika Tripathi, “Li - Fi (Light Fidelity)-The
future technology In Wireless communication”, International Journal of
Applied Engineering Research, vol. 7 No.11, 2012,ISSN 0973-4562.
4. Birender Singh Rawat, Brijesh Aggarwal, Dishant Passi, " LI - FI: A New
Era Of Wireless Communication Data Sharing", International Journal of
Scientific & Technology Research, issue 10, October 2014, ISSN 2277-8616
5. Dhakane Vikas Nivrutti, Ravi Ramchandra Nimbalkar," Light-Fidelity: A
Reconnaissance of Future Technology ",International Journal of Advanced
Research in Computer Science and Software Engineering ,ijarcsse, Issue
11, November 2013, Volume 3, ISSN: 2277 128X
6. Akshata M Sonnad, Anjana Gopan, Sailakshmi N R, Divya S, Ambika R, "
Recent advancements in Li - Fi technology", International Journal of
Electrical, Electronics and Data Communication, Issue-10, Dec-2013, ISSN:
2320-2084 Volume-1
7. Rahul R. Sharma1, Raunak2, Akshay Sanganal ,"Li - Fi Technology-
Transmission of data through light",IJCTA, Vol 5 (1),150-154, ISSN:2229-
6093

26. THANK
YOU ..