History Of Network
Drawbacks Of Before Technologies
Why Only VLC?
What is VLC?
What is Li-fi?
Advantages & Disadvantages
Internet services are very highly demanding and essential
accessories in current situation.
Presently we are utilizing the wired networks and mostly
wireless networks like Wi-Fi in our houses, offices, shops,
hotels, college campus and around 10-100 meter distances to
connect our P.C., Laptops, Mobile Phones.
As present paper tells about the newly introduced Li-Fi
technology network which is based the visible light
communication that provide a fast data speed about greater than
HISTORY OF NETWORKS
In the olden days, People formed a network in order to
transmit a piece of data from one place to another.
With the advances in technology a new networking was
developed using wires as a medium ( wired networking ).
As time passed the technology increased and we launched
satellites into space and thus were in a position to transmit
enormous amount of data across various geographical
Wireless networking gained a wide recognition and
become the most popular of all networks ( example ): Wi-Fi.
As technology keep on developing , the latest wireless
network LI-FI is introduced to overcome disadvantages of
radio frequency communication.
Drawbacks Of Before
Technologies Radio spectrum
1.4 Million base stations, 5 billion Mobile stations
600tb data every per month
Radio Spectrum is congested but the demand for wireless
data double each year. Everything, it seems want to use
wireless data but the capacity is drying up.
Available within the range of Base stations
Unavailable in aircrafts
Less secure (passes through the walls)
Cost and Expensive
Less bandwidth compared to other spectrums
Harmful to humans health
Single data stream
10,000 or 20,000 bits per second
Not usable for video streaming
CAN IT BE GAMMA RAYS ? NO
CAN IT BE X-RAYS ? NO X-RAYS HAVE SIMILAR HEALTH ISSUES
CAN IT BE UV RAYS? NO
why only VLC
CAN IT BE INFRARED WAVES ? NO INFRARED, DUE TO EYE SAFETY
REGULATION, CAN ONLY BE USED
WITH LOW POWER.
HENCE WE ARE LEFT WITH ONLY THE VISIBLE - LIGHT SPECTRUM.
GAMMA RAYS ARE RADIOACTIVE AND
DANGEROUS FOR HEALTH.
UV RAYS ARE HARMFUL FOR OUR
SKIN AND CANNOT BE USED FOR
Visible light communication ( VLC ) is a potential solution to the global
wireless spectrum shortage.
Li-Fi technology is based on Visible Light communication.
VLC is a data communication medium, which uses visible light between
400 THz and 800THz as optical carrier for data transmission and
It uses fast pulses of light to transmit information wirelessly.
What Is Li-Fi???
Li-Fi means “Light Fidelity”.
At the heart of this technology is a new generation of
high brightness light-emitting diodes.
It is possible to encode data in the light by varying the
rate at which the LEDs flicker on and off to give
different strings of 1s and 0s.
LI-FI ( Light-Fidelity ) is transmission of data through
illumination ,sending data through a LED light bulb that
varies in intensity faster than human eye can follow.
German Physicist, Dr.Harald Haas a professor in
university of Eddinburgh who began his research
in the field in year 2004.
Multiple data streamHigh speed
HOW LI-FI WORKS ?
The operation procedure is very simple, if the
LED is on, you transmit a digital 1, if it's off you
transmit a digital 0.
They can be switched on and off very quickly,
which gives nice opportunities for transmitting
The main components of this communication systems are
A high brightness white LED, Which act as a
A silicon photodiode which shows good response to
visible wavelength region serving as the receiving
The functioning of new Li-Fi technology is just simple. You will have
a light source at one end like a LED and a photo detector (Light
Sensor) on the other end.
Used in airlines: Generally in airlines mobile phones can’t be used
as they can effect the radars which are main way of communication.
Used in traffic lights which can communicate with cars to avoid
PUBLIC INTERNET HOTSPOT
Street lamps(as free access points)
Larger bandwidth ( 10,000 times the radio bandwidth )
High speed data rate
Safe for health
Low cost solution
The possibilities are numerous and can be explored further.
If this technology can be put into practical use, every bulb
can be used as Li-Fi access point to transmit wireless data
and we will proceed toward the cleaner, greener, safer
&brighter future !
This may solve issues such as the shortage of radio
frequency bandwidth and also internet where radio based
wireless isn’t allowed such as aircraft, Hospitals, etc…