LiFi concepts and applications

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…