2. LIGHT FIDELITY
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
3. NEED FOR LI-FI
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.
4. OVERCOMING WIFI ISSUES
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.
5. VISIBLE LIGHT COMMUNICATION
In electromagnetic spectrum, gamma, UV rays are dangerous
for human body.
IR rays, due to eye safety regulations, are not used
6. 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
Pure LiFi, formerly pure VLC, is an original equipment
manufacture firm setup to commercialize Li-Fi products for
integration with existing LED lighting systems
In October 2011, few companies and industries group formed
Li-Fi consortium to promote the high speed optical wireless
systems
7. HOW IT WORKS?
Operational procedure is very simple.
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.
8. IMPLEMENTATION
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 photodetector picks up the
signal
The receiver dongle then
converts the tiny changes in
amplitude into a data stream.
9.
10. LI-FI NETWORKS
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
11. LI-FI ROUTER
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
12. APPLICATIONS
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
13. TRAFFIC SCENARIO
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.
14. LECTURE / SEMINAR HALLS
Downloading notes from blogs of teachers
Often it is necessary to download
lecture notes from the blogs of
respective teachers. With Li-Fi, the
download can be done in the hall itself
Interactive classroom with interconnected devices
The classroom will be more
interactive with the real-time
interconnectivity between 500 devices
Sharing views & queries with the entire class
Each person’s queries, views and
clarifications can be shared not only
with the teacher, but with the entire
class.
15. INDUSTRIES
Used in RADIO FREQUENCY restricted environments like
chemical industries, nuclear power plants, petrol pumps.
16. HOME AND SMALL OFFICES
In home and small offices, Li-Fi can be used to communicate with devices
like
Laptops
Internet access
HD video streaming
Printer
17. AIRCRAFTS
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.
18. A PROVEN TECHNOLOGY
Harald has demonstrated Li-Fi
using an ordinary table lamp and a
computer located below the lamp.
He successfully transmitted data at
speed exceeding 10Mbps using light
waves from LED light bulbs .
Also he periodically blocked the
beam of light, causing the connection
to drop.
19. ADVANTAGES
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.
20. LIMITATIONS
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.
21. CONCLUSION
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.
