This presentation introduces Li-Fi technology. It discusses how Li-Fi works by transmitting data through LED light bulbs that vary intensity faster than the human eye can detect. This allows for high-speed wireless communication. The presentation compares Li-Fi to Wi-Fi, noting Li-Fi's higher speeds and security. Potential applications of Li-Fi discussed include use in traffic lights, hospitals, airplanes, and underwater. Challenges of Li-Fi include not working through opaque objects and requiring line of sight. The presentation concludes that Li-Fi could revolutionize wireless communication.

1. A
Presentation on
LI-FI TECHNOLOGY
M. Sai kumar
(10w91a0475)
By

2.  Introduction
 History
 Present Scenario
 Working Process
 Li-Fi vs Wi-Fi
 Applications
 Challenges for Li-Fi
 Conclusion
Contents:

3. 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.
 Introduction:

4.  Introduction:

5. 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 .
History of Li-Fi:
Prof. Harald Haas
University of Edinburgh.

6.  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.
1.4 Million Base Stations 5 Billion
Present Scenario:

7. Issues related to
communication:•Capacity
•Efficiency
•Availability
•security

8. Radio Spectrum Issues:
 Capacity
 Radio waves
 Cost and Expensive
 Less Bandwidth compared to other spectrums
 Insufficient spectrum for increasing data
 Millions of base stations consume huge amount of energy for
1.Transmitting the radio waves
2.To cool the base station cabins
 5% Efficiency
Efficiency

9.  Availability
 Available within the range of Base stations
 Limited availability
 Unavailable in aircrafts
 Less secure(passes through the walls)
 Security
Radio Spectrum Issues:

10. Electromagnetic Spectrum:

11. Radio
Waves
Infrared
Rays
Visible
Rays
Ultraviolet
Rays
X- Rays
Gama Rays
Why VLC ?
 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 besides with low power.
HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT
SPECTRUM.

12. WHO CAN REPLACE
RADIO WAVES FOR
WIRELESS
COMMUNICATION ?

13. Light - Fidelity
Li-Fi

17. Working Process:
Operational procedure is very simple, if the led is on, you
transmit a digital 1, if its off you transmit a 0. The LEDs can
be switched on and off very quickly, which gives nice
opportunities for transmitting data. Hence all that us required
is some LEDs and a controller that code data into those LEDs.
We have to just vary the rate at which the LED’s .
Flicker depending upon the data we want to encode .
Thus every light source will works as a hub for data
transmission .

18. How Li-Fi Works ?

19. How Li-Fi Works ?
On one end all the data on the internet will be streamed to a lamp driver when the
led is turned on the microchip converts the digital data in form of light .
A light sensitive device (photo detector) receives the signal and converts it back
into original data. This method of using rapid pulses of light to transmit information
wirelessly is technically referred as Visible Light Communication .

20.  Li-Fi vs Other wireless technologies:
Technology Speed Data density
Wireless (current)
Wi-Fi – IEEE
802.11n
150 Mbps *
Bluetooth 3 Mbps *
IrDA 4 Mbps ***
Wireless (future)
WiGig 2 Gbps **
Giga-IR 1 Gbps ***
Li-Fi >1Gbps ****

21. Li-Fi vs Wi-Fi:

22. Application Areas:
Li Fi technology is still in its infancy .However some
areas where it seems perfectly applicable are:-
1 . 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.

23. Potential Application of Li-Fi :
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 .

24. Potential Application of Li-Fi :
 Hospitals(In Few Medical Equipements) :

25. Potential Application of Li-Fi :
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 overcome this drawback on radio waves , li-fi is introduced.

26. 4. On Ocean Beds :
Li-Fi can even wok underwater were Wi-Fi fails completely, thereby throwing
open endless opportunities for military/navigation operations.
Potential Application of Li-Fi :

27. • There are millions of street lamps deployed around the world.
 Street Lamps (As free Access Points) :
• Each of these street lamps could be a free access point.
Application:

28. Limitations or 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 .
 A major challenge facing Li-Fi is how the receiving device will transmit back
to transmitter.
 Li-Fi requires line of sight.

29. Conclusions:
• Immense advancements in science has given a great base to develop such a
technology which could rule the communication in future of the coming years
• The Li- Fi changes the world’s communication and every path of transformation
to a very speedy, accessible, easy, safe transformation based provision
• All we need to do is fit microchip to potential illumination device which does
Illumination and wireless data transformation simultaneously
• Future would project 14 Billion lifi transmitters/access points as they would
flourish the planet’s usage in excess availability
• Li-Fi overcomes problems in issues like
Capability
Efficiency
Availability
Security & safety
• Lifi is the technology which is for a Cleaner, Greener & Brighter future of planet

30. •Li-fi is the technology which forth a
Cleaner,
Greener
Brighter,
future for the planet.