- LiFi is a light-based WiFi technology that uses visible light communication (VLC) to transmit data using LED light bulbs. It was coined by Professor Harald Haas in 2011 at TED Global. Since then, data rates have increased from 1.6 Gbps in 2013 to 5 Gbps in 2014. - LiFi uses LED bulbs to vary intensity faster than the human eye can detect to transmit digital data via light waves, instead of radio waves used by WiFi. It provides higher bandwidth capacity than WiFi as the light spectrum is much broader. - The key components of a LiFi system include a bulb, RF power amplifier circuit, printed circuit board, and enclosure to transmit data

1. LIGHT
FIDELITY
Presented By,
Gayatri P Dinesh
S5 ECE
Roll No: 28
GEC Bartonhill

2. What is LiFi?
• Light-basedWiFi
• It uses lightwaves insteadof radio waves to transmit
information.
• It works by sending data througha LED light bulbthatvaries
in intensityfaster thanthe humaneye can follow.

3. History
• Prof. Harald Haas,from the
University of Edinburgh in the UK, is
widely recognised as the original
founder of LiFi.
• He coined the term LiFi asa
bidirectional, high speed and fully
networked wireless communication
similar to WiFi.

4. In July 2011 – Prof.
Harald Haas coined
the term “LiFi” at
TED-Global 2011.
By August 2013,
data rates of over
1.6 Gbps were
demonstrated over
a single color LED.
In October 2013, LiFi
Development Kit was
created to support the
software side of the
system
In September 2013, it was
ascertained that Li-Fi, or
VLC systems in
general, do not require line-
of-sight conditions.
VLC technology
was exhibited in
2012 using Li-Fi.
In October 2011,
companies and
industry groups
formed the LiFi
Consortium.
In 2014, a speed of
5Gbps was achieved
with a promise to
reach 10Gbps soon

5. In February 2016..

6. What’s wrongwith WiFi and howLiFi fill the
voids..?
CAPACITY
AVAILABILITY SECURITY
EFFICIENCY

7. Why Visible Light Communication?
• Gamma rays are radioactive and are dangerous.
• X-rayshave similarhealth issues.
• Ultraviolet light is good for place without people,but other wise
dangerous for the human body.
• IRWaves are harmful for our eyes hence can’t be used.

8. Construction..
The LiFi system consists of four primary sub-assemblies:
• Bulb
• RF power amplifier circuit
• Printed Circuit Board
• Enclosure

9. • The PCB controls the electricinputs and outputs of the lamp and
houses the microcontroller used to manage different lamp functions.
• An RF (Radio-Frequency) signalis generated by the solid-state PA and
is guided into anelectronic 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 sub-assemblies are contained in an aluminum enclosure.

10. Let’s take a look into the technology..

11. Internet is received in
terms of stream of bits of
1’s and 0’s.
Lamp Driver converts
this stream of bits into
sequence of signalsto
turn the LED on and off
at rapid rate

12. • A light sensitive device receives thissignal and converts it back into
original data.
• A receiver dongle then converts the tiny changesin amplitude into an
electrical signal, which isthen converted back into a data stream and
transmitted to a computer or mobile device.
• Thismethod of usingrapid pulses of light to transmit information
wirelessly is technicallyreferred to asVisible Light Communication
(VLC).

13. WiFi v/s LiFi
WiFi LiFi
• Use radiowaves • Use visible light
• Radiospectrum is congested andthe demand forwireless
data keeps on increasing
• Spectrum of visible light is broader and10000 times higher
than radiowaves.
• Slower than LiFi • Produces a speed 100x faster than WiFi
• Coverage distance is about 32 meters . • Coverage distance is about 10 meters .
• Data is transmitted by bits in serial fashion • Data transmission is carried out in a parallel fashion
• Speed cannot be controlled • Speed is controllable byvarying intensity oflight
• Fails towork well in dense environment • works well in dense environment
• less secure due totransparency. • Moresecure due tonon penetration oflight through walls
• Compatible with IEEE802.11 a/b/g/n/ac/ad devices. • Compatible with IrDa(InfraredData Association) devices

14. Advantages..
• It has no side effects on any living thing
• It uses very low-heat emitting mediums such asLEDs which are
environment friendly
• It is safe to be used in radio wave sensitive environments
• It does not require any bandwidth spectrum
• Any lighting device can be used asa hotspot
• It can be used underwater

15. Disadvantages..
• Light can’t pass through objects
• Interferences from external light sources like sunlight, normal bulbs,
and opaque materials in the path of transmission will cause
interruption in communication
• High installation cost of VLC systems
• We can’t have a light bulb that provides data to a extremely high-speed
moving object or to provide datain a remote area where there are
trees and walls and obstacles behind.
• Infrastructure Dependency

16. Applications..
• Intrinsicallysafe environments
• In aircrafts
• Underwatercommunication
• Safety andmanagement
• Public internethotspots
• Hospitals
• Avoidance of accidents
• Product retailing
• Offices
• Lecture/Seminarhalls
• SmartMuseums

17. References..
http://www.electronicsforu.com/electronicsforu/circuitarchives/view_article.a
sp?sno=778&title%20=%20LiFi%3A+A+New+Paradigm+in+Wireless+Commu
nication&btype=new&id=12042
http://en.wikipedia.org/wiki/Li-Fi
http://www.slideshare.net/tanshu9871/lifi-technology

18. Questions...???

19. Thank You..