1. LI-FI TECHNOLOGY
Abstract:
wireless communications has become a utility like electricity and
water. We use it everyday.
Whether you’re using wireless internet in a coffee shop, stealing it
from the guy next door, or competing for bandwidth at a conference,
you have probably gotten frustrated at the slow speeds you face
when more than one device is tapped into the network. As more
and more people and their many devices access wireless internet,
clogged airwaves are going to make it.so to make the internet
experience more faster--->>safer-->>greener,, we are running
towards more faster ,light based technology that can produce data
rates faster than 10 megabits per second,ie,,you could download a
full HD movie withn 30secs, which is speedier than your average
broadband connection. This technology is called light fidelity which
was found by Harald Hass

2. Do you know that we have 1.4 million cellular radio masts deployed
worldwide? And these are base stations. And we also have more
than five billion of devices like cellular phones.And with these
mobile phones, we transmit more than 600 terabytes of data every
month. This is a 6 with 14 zeroes -- a very large number.
There are four important issues on wifi & the solutions for
the issues using lifi--->>>>
1-->>capacity:
wifi uses radio waves, wich
are limited & expensive too...
actually we are running out of
spectrum
solution based on lifi:
We have 10,000 times more spectrum, 10,000 times more LEDs
installed already in the infrastructure there. You would agree with
me, hopefully, there's no issue of capacity anymore
2-->>efficiency:
there are 1.4 million base stations that consume lots of energy but
most of energy is used to cool base stations & not transmitting radio
waves at its fullest
lifi based solution:
This is data through illumination -- it's first of all an illumination

3. device. And if you do the energy budget, the data transmission
comes for free -- highly energy efficient. I don't mention the high
energy efficiency of these LED light bulbs. If the whole world would
deploy them, you would save hundreds of power plants.
3-->>security:
wifi could be easily stolen when someone cracks your
password.but, lifi is highly secured way of data transmission
because,we all know that light waves cannot travel beyond walls
.so, data in that particular room cannot be stolen or illegally
accessed.
4-->>electromagnetic spectrum used for transmitting radio
waves,produce some harm to human body.so phones are to be
switched off in flights,hospitals etc.., but one can have access to
high speed internet at low rate and no harm ,even inside icu ,by
using this emerging light based technology,since
it uses visible light.
Working:

4. Very simple, if the LED is on, you transmit a digital 1, if it’s off you
transmit a 0. The LEDs can be switched on and off very quickly,
which gives nice opportunities for transmitting data.” So what you
require at all are some LEDs and a controller that code data into
those LEDs.these LED's does two jobs 1) illumination 2)
transmitting data .
APPLICATIONS:
--->>> the applications of it, to me, are beyond imagination at the
moment. where we have light, there is a potential way to transmit
data. But I can give you a few examples.
-->> This is a remote operated vehicle beneath the ocean. And they
use light to illuminate space down there. And this light can be used
to transmit wireless data that these things to communicate with
each other.
--->>>Intrinsically safe environments like this petrochemical plant --
you can't use RF, it may generate antenna sparks, but you can use
light -- you see plenty of light there.
--->>>In hospitals, for new medical instruments.
--->>> in streets for traffic control.
--->>>Cars have LED-based headlights, LED-based back lights,
and cars can communicate with each other and prevent accidents
in the way that they exchange information. Traffic lights can
communicate to the car and so on.
--->>>And then you have these millions of street lamps deployed
around the world. And every street lamp could be a free access

5. point. We call it, in fact, a Li-Fi, light-fidelity.
--->>>And then we have these aircraft cabins. There are hundreds
of lights in an aircraft cabin, and each of these lights could be a
potential transmitter of wireless data. So you could enjoy your most
fav video on your long flight back home.