The document provides an overview of Li-Fi technology. It begins with an introduction and comparison to Wi-Fi. It then discusses the evolution of Li-Fi and its working components. Li-Fi uses visible light communication and LED bulbs to transmit data wirelessly. It has advantages over Wi-Fi such as higher speeds, more available spectrum, and more secure communication. However, it also has limitations since light cannot penetrate walls and data transmission can be blocked by objects. In conclusion, Li-Fi shows potential for high-speed wireless communication if practical challenges can be addressed.

1. Presented by
P.GEETHA
Ph.D scholar-NIT-Trichy
P.GEETHA
Associate Professor

3.  Introduction
 Comparison
 Evolution of Li Fi
 Working
 Components
 Construction
 Applications
 Advantages
 Limitations
 Conclusion

4.  Li-Fi is transmission of data through illumination,
sending data through a LED light bulb.
 Li-Fi, or light fidelity, is 5G visible light
communication systems using light from light-emitting
diodes (LEDs) as a medium to deliver networked, mobile,
high-speed communication in a similar manner as Wi-
Fi and Optical fiber.
 Li-Fi could lead to the Internet of Things.

5.  Optical version(Light based) of Wi-Fi
 Light is used instead of radio-waves to transmit
information
 Transceiver fitted LED lamps acts like Wi-Fi modems
 LED lamps can light a room as well as transmit-receive
information
 Provides illumination as well as data communication

6.  Radio spectrum is congested, but
the demand for wireless data
doubles each year
 Issues regarding radio spectrum,
such as capacity, availability,
efficiency, security are solved
using LiFi.
 Speed of data transmission can
be increased.

7. Fire wire 800 Mbps
USB 3.0 5 Gbps
Thunderbolt 20 Gbps
Wired
Wireless(Current)
Wireless(Future)
Li-Fi 10 Gbps
Giga-IR 1 Gbps
Wi-Gig 2Gbps
Wi-Fi 150 Mbps
Bluetooth 3 Gbps
IrDA 4 Gbps

8.  CAPACITY
 Spectrum is 10,000 times greater than that of radio
frequency
 EFFICIENCY
 Highly efficient since LED consumes less energy
 AVAILABILITY
 Light waves available everywhere.
 SECURITY
 Cannot penetrate through walls. Hence data cannot be
intercepted.

9.  Li-Fi can be the technology for the future where data for
laptops, smart phones, and tablets will be transmitted
through the light in a room.
 Security would not be an issue because if you can‘t see
the light, you can‘t access the data. As a result, it can be
used in high security military areas where RF
communication is prone to eavesdropping.

10.  In electromagnetic spectrum, gamma, UV rays are dangerous
for human body.
 IR rays, due to eye safety regulation, can only be used with
low power.

11. Li-Fi is a Visible Light Communication (VLC), technology
developed by a team of scientists including Dr. Gordon Povey,
Prof. Harald Haas and Dr. Mostafa Afgani at the University of
Edinburgh.
Prof. Harald Haas

12. 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.
Professor Harald Haas
Original founder of Li-Fi.
Chairman of Mobile Communications at the
University of Edinburgh.
 Co-founder of pureLiFi. Prof. Harald Haas
University of Edinburgh,U.K

13. In October 2011, Li-Fi Consortium- promote high-speed optical
wireless systems .
VLC technology was exhibited in 2012 using Li-Fi.
By August 2013, data rates of over 1.6 Gbit/s were demonstrated
over a single color LED.
In September 2013, a press release said that Li-Fi, or VLC systems
in general, do not require line-of-sight conditions.
In October 2013, it was reported Chinese manufacturers were
working on Li-Fi development kits.
Philips lighting company has developed a VLC system for
shoppers at stores. They have to download an app on their smart
phone and then their smart phone works with the LEDs in the store.

14. Operational procedure is very simple.
 Normal light power is replaced by LED light power.
 The LED bulb will hold a micro-chip that will do the job of processing the data.
 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 LEDs is
used to code data.
 Also called as 5G optical communication.
Parallel data transmission

15. TRANSMITTER RECIEVER/RECEPTOR END

16. 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
extremely high speed
The photo detector picks up
the signal
The receiver dongle then
converts the tiny changes in
amplitude into a data stream.

17. A high brightness white LED, Which act as a communication
source.
A photodiode which shows good response to visible wavelength
region serving as the receiving element.

18. The LI FI product consists of 4 primary sub-assemblies:
• Bulb
• RF power amplifier circuit (PA)
• Printed circuit board (PCB)
• Enclosure

19.  Li-Fi technology is based on LEDs for the transfer
of data.
 The transfer of the data can be with the help of all
kinds of light.
 Also, the speed of the internet is incredibly high
and we can download movies, games, music etc in
just a few minutes with the help of this technology.

21.  Li-Fi connector and router are the
main components for a network
 Room connector:
 Optical signals cannot penetrate
through walls, in order to provide
an optical WLAN, rooms need to
be connected with each other
 Li-Fi room connector is a
replicator, which sends the data
stream from one side of the wall
to the other side via an optical
fiber.
 For smaller rooms, connector act
as the only Li-Fi hotspot in the
room

22. Serves as a connector to external
link like DSL.
 Covers a radius of about 20 meters
 The transmission speed is 100 Mbps.
 Suitable for small office or home use

23.  LiFi can be used in
 sensitive areas such as aircrafts for data transmission
without causing interference
 Places where it is difficult to lay optical fibers like
operation theaters
 Traffic scenarios, thereby reducing accidents
 Underwater applications where radio waves cannot
propagate.
 Industries like petrochemical plants, nuclear power plants
, petrol pumps etc

24. In traffic scenario, LiFi can be used to
communicate with the LED lights of
cars
 Cars can have LED-based headlights,
backlights and can communicate with
each other.
 This might prevent accidents, by
exchanging information, when the
vehicles are too close
 Using LiFi, Street lights can be used
to send information about the road
condition to the car.

25. • Downloading notes from blogs of teachers.
• Interactive classroom with interconnected devices.
• Sharing views & queries with the entire class

26. Li-Fi can even wok underwater were Wi-Fi fails completely,
thereby throwing open endless opportunities for
military/navigation operations.

27. Used in RF restricted environments like chemical industries,
nuclear power plants, petrol pumps

29.  In home and small offices, Li-Fi can be used to communicate
with devices like
Laptops
Internet access
HD video streaming
Printer

30. The whole airways communication
are performed on the basis of radio
waves.
Hence passengers face the
problem in communication media.
This problem can be overcome by
using Li-Fi, since light waves will
not interfere with radio waves.

31.  There are millions of street lamps deployed around the
world.
 Each of these street lamps could be a free access point.

32.  The first VLC Smartphone was
presented by Consumer Electronics in
January, 2014
 The phone uses Wysips connect – a
clear thin layer of crystal glass is
added to the small screens
 Smartphone makes them solar
powered.
Smartphone could get 15% more
battery life in a day
Can communicate using Li-Fi.

33.  Data rate greater than 10 Gbps; Theoretically allowing HD film
to be downloaded in 30 seconds
 Can be used anywhere, even in RF restricted areas; Since light
waves will not interfere with radio waves.
 Mostly LED light bulbs are used, which consumes less energy.
Hence cost efficient.
 As light waves cannot penetrate through walls, the data cannot
be intercepted; Thus provides secured communication.
 Efficient alternative to radio based wireless; since it is quick
and reliable.

34.  Visible light cannot penetrate through solid objects.
 A major challenge of LiFi is how the receiving device will
transmit back to transmitter.
 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.

35. 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.

36. Thank You…