LIFI (Light Fidelity) is a new technology that uses visible light communication for wireless transmission of data using LED light bulbs. It was introduced by Professor Harald Haas at the University of Edinburgh. LIFI provides illumination as well as high-speed wireless communication and has advantages over WiFi such as higher speed, more secure transmission, lower cost, and an unregulated and vast light spectrum. However, it also faces challenges of light not penetrating solid objects and interference from other light sources. Potential applications of LIFI include use in airplanes, traffic lights, street lamps, and industries where radio transmissions are restricted.
2. TABLE OF CONTENT:-
‡ INTRODUCTION
‡ LIFE OF LIFI
‡ ELECTROMAGNETIC SPECTRUM
‡ WHY ONLY VLC?
‡ PRESENT SCENARIO
‡ ISSUES OF RADIO SPECTRUM
‡ WORKING PROCESS OF LIFI
‡ WHY FLUCTUATIONS ARE NEEDED?
‡ IMPLEMENTATION OF LIFI SYSTEM AND ITS
WORKING
‡ LIFI VS WIFI
‡ ADVANTAGES
‡ LIMITATIONS AND CHALLENGES
‡ APPLICATIONS
3. Introduction:-
Light based 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.
4. LIFE OF LIFI:-
Introduced by Professor Herald Hass, at
the university of Edinburgh.
Established in
2011 TED
global talk.
The promotion
of idea through
TED helped to
start a company,
Pure LiFi.
7. Continuation..
Radio waves is used as transceiver for
communication, television, cell phones and
radios .But these waves are restricted in many
areas of industries, airlines etc.
Microwaves are used in radar communications,
and for heating in microwave ovens and in
various industrial processes.
Hence we are left with only visible spectrum.visible spectrum.Hence we are left with only
8. PRESENT SCENARIO:-
Radio Spectrum is congested but the
demand for wireless data doubles each year.
Everything, it seems want to use wireless
data but the capacity is drying up.
1.4 MILLION BASE 5 BILLION MOBILE PHONES
9. ISSUES OF RADIO
SPECTRUM:-
• Available within the
range of Base stations
• Limited availablity
• Unavailable in aircrafts
• Less secure(passes
through the walls)
• Millions of base stations
consume huge amount of
energy for
• Transmitting the radio
waves
• To cool the base station
cabins
• Cost and Expensive
• Less Bandwidth
compared to other
spectrums
• Insufficient spectrum for
increasing data
CAPABILITY EFFICIENCY
AVAILABILTYSECURITY
10. WHAT CAN BE REPLACED IN
PLACE OF RADIO WAVES FOR
WIRELESS COMMUNICATION
LIFI-LIGHT FIDELITY
11. WORKING PROCESS OF
LIFI:-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 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 on and off.
Flicker depending upon the data we want to encode.
Thus every light source will works as a hub for data
transmission.
14. LED DRIVER CIRCUIT:-
This led driver is base for generating
required fluctuations in the led’s.
This is the major part of the lifi technology
which varies the normal led’s with that of a
lifi led’s.
15. HOW LIFI 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.
16. HUB:-A hub is a common connection
point for device in a network. Hubs are
commonly used to connect segments of
a LAN. A hub contains multiple ports.
When a packet arrives at one port, it is
copied to the other ports so that all
segments of the LAN can see all packets.
Lamp driver is connected to a hub and
given to different led’s in our
surroundings.
17. LIFI VS WIFI:-
S.No. PARAMETERS LIGHT
FIDELITY
WIRELESS
FIDELITY
1. Speed for data
transfer
Faster transfer
speed(>1Gbps)
Data transfer
speed(150Mbps)
2. Medium through
which data transfer
occurs
Uses light as carrier Uses radio
spectrum
3. Spectrum Range Visible light spectrum
has 10,000 times
more broad spectrum
in comparison to radio
spectrum
Radio frequency
spectrum range is
far less than the
visible light
spectrum
4. Cost Cheaper than Wifi
because it is a free
band and don’t need
any license as it uses
light
Expensive in
comparison to Lifi
because it uses
radio spectrum
5. Security High secure Less secure
6. Operating frequency Hundreds of Tera Hz 2.4 GHz
18. ADVANTAGES:-
It can be used anywhere in the RF restricted
areas. Since light waves it does not interfere
with any radio waves.
Mostly LED bulbs are used,which
consumes less energy.Hence cost efficient.
As light cant penetrate through walls it is
more secured communication.
More efficient than radio waves wireless
communication.
Date rate is greater than 1 gbps.Hence we
can download any files in fews seconds.
19. LIMITATIONS &
CHALLENGES:-
Light cannot penetrate through solid
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.
A major challenge facing LiFi is how the
receiving device will transmit back to
transmitter.
Light communication is not possible in
darkness.
20. Applications:-
Traffic lights:-
Traffic lights can
communicate to the
car and with each
other. Cars have LED-
based headlights,
LED-based back
lights, and cars can
communicate with
each other and prevent
accidents in by
exchanging
information.
21. Continuation..
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
radiowaves, li-fi is
introduced.
22. Continuation..
Ocean Beds :-
LiFi can even work underwater were Wi-Fi
fails completely, thereby throwing open endless
opportunities for military/navigation operations.
23. Continuation..
Street Lamps:-
There are millions of street lamps deployed
around the world. Each of these street lamps
could be a free access point.
26. Continuation..
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 could get
15% more battery life in a
day.
27. Conclusion:-
Thus,the possibilities are numerous and
can be explored further. It provides
simple, faster and efficient wireless data
communication. Li-Fi will make us to
proceed towards the cleaner, greener, safer
and brighter future.