In this video, you will learn about the Li-Fi Technology, which is the abbreviation of the term Light Fidelity.
So, in this video, we will see how Li-Fi technology works, what are the advantages of this Li-Fi over other wireless communication technologies like Wi-Fi and 4G/LTE, and what are the applications of this Li-Fi.

What is Li-Fi?

Li-Fi is light based bi-directional, fully networked, wireless communication technology, where the light source is used to transmit the data wirelessly.

By turning LED light On and Off very rapidly (Millions time per seconds), we can transmit the data wirelessly.

Advantages of Li-Fi over other Technologies:

1) Speed: Li-Fi has the capability to provide speed up to 100 Gbps (Max .Recorded speed is 224 Gbps !!!)

2) Security: As light can not cross the walls, so data cannot be hacked by outsiders and hence it provides one more layer of security

3) Safety: Unlike radio waves, exposure to light is safer for human beings

4) Congestion free: The bandwidth of light spectrum is 1000 times more than radio spectrum and hence it is congestion free as well as free of electromagnetic interference

Applications of Li-Fi:
Although Li-Fi is futuristic technology, once it will be commercially available there are many applications of this technologies

1) Hospitals
2) Underwater Communication
3) Vehicular communication
4) High-speed internet through street lights

The time stamps for the different topics in the video is given below:

0:20 What is Li-Fi ??

0:50 How Li-Fi works? (Principle of Li-Fi technology)

3:10 Advantages of Li-Fi technology

6: 30 Applications of Li-Fi

This video will be helpful to everyone in understanding the concept of Li-Fi.

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Hey friends, welcome to the YouTube channel
ALL ABOUT ELECTRONICS.

So, in this video, we will learn about the
Li-Fi technology.

Which is the abbreviation of term Light Fidelity.

So, in simple terms, we can say that this
Li-Fi technology is nothing but light based

wi-fi technology.

And as we know, this Wi-Fi is fully networked,
bi-directional wireless communication technology.

Where data is being transmitted using the
radio waves.

While in the case of Li-Fi technology, the
data is transmitted in the form of visible

light using the LED light source.

So, this house hold LED bulbs and LED lamps
which are used as a light source can also

be used to transmit the data.

So, first of all, let’s understand how this
Li-Fi technology works.

So, if you see any LED light source, if you
provide the constant current to this LED bulb,

it provides the constant illumination or constant
brightness.

So, as we change the current that is flowing
through the LED bulb, the illumination or

brightness of this bulb will change.

So, this princi[ple is used for transmitting
the data wirelessly using this Li-Fi technology.

So, if no current or minimum current is flowing
through this LED bulb then, the brightness

of this LED source will be minimum.

And that will be treated as digital 0.

So, digital 0 will be transmitted at the receiver
side.

Similarly, when the light bulb is ON, or we
can say that if the maximum amount of current

is flowing through this LED bulb then the
illumination or brightness of the LED bulb

will be maximum.

And that will be treated as digital 1.

So, whenever the LED is ON, so digital 1 will
be transmitted at the receiver side.

So, in this way, by flickering the LED light
source very rapidly we can transmit the data

in the form of 1’s and 0’s to the receiver.

And if this flickering is happening at million
times per second then we can not see this

flickering by our naked eyes.

And we can treat this LED bulb source as normal
regular bulb source.

So, now let’s see the schematic of Li-Fi transmitter
and receiver system.

So, as you can see, the data which is coming
from the web server or the internet first

it will go to the MODEM, which provides the
necessary modulation to the incoming data

stream.

Then this modulated data is fed to the LED
driver, which changes the driving current

for this LED bulb according to the incoming
streaming data.

At the receiver end, if you see, the optically
received data is first converted into the

electrical signal using the photo receiver
or photo diode.

And after the signal conditioning, this data
is being fed to the computer or laptop.

So, to receive this incoming data, at the
receiver side we require the Li-Fi dongle,

which consists of photo receiver as well as
IR transmitter.

Now this infrared transmitter can be used
to transmit the uplink data back to the LED

source.

Now, one such company which provides the complete
Li-Fi solution is Pure LiFi.

Which generally makes these Li-Fi dongles.

So, now as we know, how this Li-Fi technology
works, now let’s see the advantages of this

Li-Fi technology over the other wireless communication
technologies.

So, these are the some of the advantages of
the Li-Fi technology over the other wireless

communication technologies.

So, first let’s talk about the speed.

So, so far the researchers have achieved the
speed up to the 10 Gbps in the lab scale prototype

models.

And this speed can further be enhanced by
using the array of LED source or by using

the multiple colours of LEDs like RGB LEDs,
where each LED source is able to transmit

the data up to the 10 Gbps.

So, using such technologies, the researchers
have achieved the maximum speed up to the

100 Gbps.

So, now let’s compare its speed with other
wireless communication technologies.

So, if we compare it with 4G/LTE or particularly
the LET advanced, the maximum achievable speed

under this LTE advanced is 1 Gbps for the
stationary user and 100 Mbps for the mobile

user.

But all these speeds are the theoretically
achievable maximum speed.

But actual speed may be much lesser compared
to this theoretically achievable maximum speed.

So, if you see the countries which provide
the fastest internet in the world, the average

4G/LTE speed in such countries is in the range
of 40-50 Mbps, which is much lesser compared

to the speed which is provided by
the Li-Fi.

So, now let’s compare the speed of Li-Fi with
Wi-Fi.

Now, in case of Wi-Fi, if you see the standard
IEEE 802.11.ac, the maximum speed which can

be supported by this standard is 1.3 Gbps.

And that is in the 5 GHz band, which is almost
100 times lesser compared to the speed which

is supported by the Li-Fi.

And if you see the another Wi-Fi standard,
which is not commercially available yet, that

is IEEE 802.11.ad, the maximum speed which
can be supported by this standard is 7 Gbps.

And all the speeds which are mentioned over
here are the theoretically achievable maximum

speeds.

But the actual speeds may be quite lesser
compared to the theoretically achievable maximum

speeds.

And still, if we consider the maximum speed
which is supported by this Wi-Fi technology,

the Li-Fi technology is still 10 times faster
compared to this Wi-Fi technology.

Well, right now the speed which is provided
by the Wi-Fi technology is sufficient for

our day to day life.

But as we are moving in the era of Internet
of Things, where each device is able to communicate

with each other, soon you will find that the
speed which is provided by the Wi-Fi technology

is insufficient.

And you will require the insane speed like
100 Gbps, which as of now looks like a dream.

So, next, if you see the electromagnetic spectrum,
the bandwidth of the radio wave is up to 300

GHz.

But if you see the bandwidth of this visible
spectrum alone, the bandwidth of this visible

spectrum is around 300 THz.

Which is almost 1000 times more compared to
the bandwidth of the radio waves.

So, not only you can achieve the higher speed
but also you will not find any kind of electromagnetic

radio interference.

So, now in the case of Li-Fi, as we are using
the visible light source, the visible light

source can not cross the walls, unlike the
case of Wi-Fi, where the radio waves are able

to transmit across the walls.

So, in this way, this Li-Fi technology provides
the one more layer of security.

So, these are the advantages of this Li-Fi
technology over the other wireless communication

technologies.

So, now let’s see the different applications
of this Li-Fi technology.

So, this Li-Fi technology can be used in the
hospitals.

As this Li-Fi technology is providing very
high-speed internet communication, so the

real time health monitoring of the patient
will be possible.

So, apart from that this Li-Fi technology
can be used for the under water communication.

Also, using this technology, the vehicles
can communicate with each other using the

front and the rear lights.

And using this technology, we can prevent
the accidents.

Also, this Li-Fi technology can be used in
the aeroplanes to provide the internet to

the passengers.

And not only that if this technology is fitted
into our street lights, then even our street

lights can provide us high-speed internet.

So, these are the some of the applications
in which this Li-Fi technology can be used.

But still, if you see, this Li-Fi technology
is the futuristic technology.

That means, the commercially there are no
products which are available which provides

the insane speed up to the 10 Gbps or 100
Gbps.

So, in the upcoming years, we might see the
technlgies or devices which support this Li-Fi

technology.

So, right now, as we are seeing the Free Wi-fi
Zone in the cafeteria, in future we might

see Free Li-Fi zone in the cafeteria.

So, now bigger question is if Li-Fi is the
future of internet then what about the already

existing wireless technologies.

So, the answer is that in future also all
the existing technologies will remain.

And rather this Li-Fi technology will complement
all the existing technologies.

Because this Li-Fi is short range communication.

So, using this technology we can not cover
the entire area using the light.

So, grossly we can say, when you require large
coverage, we will still prefer Wi-Fi and 4G/LTE

but in short coverage, like in the case of
our room or hotel or even offices, we can

still prefer this Li-Fi technology.

So, I hope in this video, you understood about
this Li-Fi technology.