1. S O L U T I O N F O R S L O W I N T E R N E T
P R E S E N T E D B Y
N I S H A N T H C H A N D R A N
LIFI
2. INTRODUCTION
Li-Fi(Light Fidelity) basically the sending of the
digital signals via light.
It work's better in comparison to conventional
approaches
Li-Fi technology was invented by Harald Haas,
It gives nice opportunities for transmitting data,it
is practically feasible to encode the digital data in
the light by altering the data rate at which the
LEDs flicker's ON and OFF to give the various
numerous strings of digital Is and Os.
3. WHAT IS LIFI
Li-Fi is the transmission of data through
illumination by taking the fiber out of fiber optics
by sending data through a LED light bulb.
This varies in intensity faster than human eye can
follow.
It is the fast and cheap wireless communication
system which is optical which is optical version of
the Wi-Fi.
4. NEED FOR LIFI
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.
6. 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.
7. HISTORY
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. Harald
Haas continues to wow the world with the potential to use
light for communication
on 12th July 2011. He used a table lamp with an LED bulb
to transmit a video of blooming flowers that was then
projected onto a screen behind him. During the event he
periodically blocked the light from lamp to prove that the
lamp was indeed the source of incoming data.
9. Cont..
THE HEART OF THIS TECHNOLOGY IS A NEW GENERATION
HIGH BRIGHTNESS LED’S.
THESE LED’S VARIES IN INTENSITY (THAT IS GETS ON AND OFF)
SO FAST THAT A HUMAN EYE CANNOT DETECT IT.
IF LED IS ON , THEN WE TRANSMIT A DIGITAL SIGNAL 1,AND IF
THE LED IS OFF , THEN WE TRANSMIT A DIGITAL SIGNAL 0.
A CONTROLLER IS CONNECTED AT THE BACK SIDE OF THESE
LED BULBS TO CODE DATA TO THESE LED’S.
10. 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.
13. 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
14. 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
15. 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
16. 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.
17. 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
18. 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.
19. 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.
20. 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.
