Wireless Communication Systems Using Light as a Medium

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
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4. Issues with radio waves
Capacity
Efficiency
Availabilit
y
Security
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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.
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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
RadioWaves
at EM spectrum.
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.
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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.
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13. How it Works?
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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.
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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.
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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
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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.
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20. Thank You For Your Attention!
Li-Fi
A Seminar Presentation by
Mithun Madhusoodanan
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21. Questions
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22. Video Demonstration
Li-Fi Demonstration by Harald Hass at TED talk.
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