Li-Fi uses LED lights to transmit data wirelessly by switching the lights on and off very quickly. It has the potential to overcome issues with radio wave wireless technologies like limited capacity, inefficiency, limited availability in some areas, and security issues. Li-Fi provides over 10,000 times more available spectrum than radio waves and has already been demonstrated to transmit data speeds over 10Mbps. It could be used anywhere there is light and avoids issues with penetrating walls or being intercepted. Potential applications include use in places where radio waves don't work well like hospitals, traffic lights, street lights, and aircraft.

1. By
Mithun Madhusoodanan

2. 
Li-Fi is transmission of data through illumination.

LED Bulb varies in intensity faster than the human eye can
follow.

LED lights can be switched on and off at high speeds.

This property is the basics for Li-Fi

LED when on gives binary 1 and off gives binary 0
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3. Present Scenario

We have 1.4 million cellular
base stations deployed

We also have 5 billion of
mobile phones

Mobile phones transmit
600tb of data every month

Wireless communication has
become an utility like
electricity and water

We use it in our everyday
life, private life, business
life

Currently Wi-Fi uses radio
waves
3

4. Issues with radio
waves
Capacity
Efficiency
Availabil
ity
Security
4

5. Capacity
 We
transmit wireless data through radio
waves.
 Radio
waves are limited.
 Radio
waves are scarce and expensive.
 We
only have certain range of it.
 With
advent of new technologies like
2G,3G,4G we are running out of spectrum.
5

6. Efficiency

There are 1.4 million cellular radio base
stations.

They consume massive amount of energy.

Most of this energy is not used for
transmission but for cooling down the base
stations.

Efficiency of such a base station is only 5% and
that rise a big problem.
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7. Availability
 Availability
of radio waves or RF signals
causes another concern.
 We
have to switch off mobile phones in
airplanes.
 Radio
 It
waves cannot be used under water
is not advisable to use mobiles at places
like petrochemical plants and petrol
pumps.
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8. Security
 Radio
 They
 If
waves penetrates through walls.
can be intercepted.
someone has a knowledge and bad
intentions then he may misuse it.
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9. Alternative to Radio Waves in
Electromagnetic spectrum

Looking at EM spectrum.
RadioWaves






InfraWaves
Visible
Rays
UltraViolet
X-rays
Gamma
Rays
Gamma rays are simply dangerous and thus
can’t be used for our purpose of
communication.
X-rays are good in hospitals and can’t be used
either.
Ultra violet rays are sometimes good for our
skin but for long duration it is dangerous.
Infrared rays are bad for our eyes and are
therefore used at low power levels.
We have already seen the short comings of
radio waves.
So we are now left with Visible Rays.
9

10. Light for Wireless
communication

Light has been around for millions of years

It has created us, has created life and has created all
stuffs of life.

Light is part of electromagnetic spectrum

There are 40 billion light box already installed

Flickering lights are annoying but thy may have an
upside.

Li-Fi uses rapid pulses of light to transmit information
wirelessly.

It is inherently safe to use and would be great if we can
use it for our wireless communication.
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11. What we have to do?
 We
have to replace the inefficient
fluorescent lights with new dignitaries
of LED lights.
 It
is a semi conductive e-device.
 Light
intensity can be modulated at very
high speeds to send data by tiny changes
in amplitude.
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12. How we do this?
 Remote
controls have an IR led.
 It creates a single data stream.
 Replace remote control with light
box.
 With this technology we transmits
1000’s of data stream in parallel at
high speeds.
12

13. Works?
13

14. Is it a proven
technology?

Yes, this is already proven.

Harald Hass demonstrated his invention
using an ordinary table lamp that
successfully transmitted data at speeds
exceeding 10Mbps .

To prove that the light bulb was the
source of data stream, he periodically
blocked the beam of light, causing the
connection to drop.
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15. Overcoming the four issues in
Li-Fi
Capacity
 10000times more spectrum than Radio
waves.
 Light box are already present.
 We have the infrastructure available and
already installed.
Efficiency
 Data through illumination and thus data
transmission comes for free.
 Led light consumes less energy.
 High efficient.
15

16. Availability
 Light is present everywhere.
 Can be used in airplanes
 It can be underwater where radio waves cannot.
Security
 Light waves doesn’t penetrate through walls.
 Can’t be intercepted and misused.
 Data is present where there is light.
16

17. Applications

Can be used in the places where it is difficult to
lay the optical fiber like hospitals. In operation
theatre Li-Fi can be used for modern medical
instruments.

In traffic signals Li-Fi can be used which will
communicate with the LED lights of the cars and
accident numbers can be decreased.

Thousands and millions of street lamps can be
transferred to Li-Fi lamps to transfer data.

In aircraft Li-Fi can be used to transmit data.

It can used in petroleum or chemical plants
where other transmission or frequencies could
be hazardous.
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18. Limitations
 There
should be line of sight between
sender and receiver
 Visible
light cannot penetrate through
solid objects
 Interference
with other electromagnetic
waves makes the transmitting data to
distort
 Light
cannot approach the range and
penetration of radio waves
18

19. Conclusion
The possibilities are numerous and can be explored
further. If this technology can be put into practical
use, every bulb can be used something like Wi-Fi
hotspot to transmit wireless data and we will
proceed onwards the
Cleaner, Greener, Safer and Brighter future.
19

20. Thank You For Your
Attention!
Li-Fi
A Seminar Presentation by
Mithun Madhusoodanan
20

21. Questions
21

22. Video
Demonstration
Li-Fi Demonstration by Harald Hass at TED talk.
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