Li-Fi: advanced technology of future generation.

1. Li-Fi Technology

2. CONTENTS
 Applications:
oAircrafts
oHospital
oTraffic scenarios
oUnderwater applications
oLecture halls
oIndustries
oHome and small offices
 A proven technology
 Advantages
 limitations
 Conclusion

3. INTRODUCTION
 Light-fidelity: Li-Fi is transmission of data through illumination, sending data through LED
light bulb that varies intensity faster than human eye can follow.
 Li-Fi is a wireless optical networking technology that uses light-emitting diodes (LED) for
data transmission.
 Li-Fi is designed to use LED light bulbs similar to those currently in use in many energy-
conscious homes and offices.
 However, Li-Fi bulbs are outfitted with a chip that modulates the light imperceptibly for
optical data transmission.
 Li-Fi is transmitted by the LED bulbs and received by photoreceptors.

4. PRESENT SCENARIOS
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.
ISSUES REGARDING RADIO SPECTRUM:
 Capacity: Spectrum is 10,000 times greater than that of radio frequency.
 Security: Cannot penetrate through the walls, hence data cannot be intercepted.
 Efficiency: Highly efficient since LED consumes less energy
 Availability.

5.  Gamma-rays cannot be used as they could be dangerous.
 X-rays have similar health issues.
 Ultraviolet light is good for place without people, but otherwise dangerous for the human body.
 Infra-red due to eye safety regulation, can only be used with low power.
Hence, we left with only the visible-light spectrum.
ELECTROMAGNETIC SPECTRUM:

6. Li-Fi VS. Wi-Fi:
PARAMETERS WIRELESS TECHNOLOGIES
Light fidelity Wireless fidelity
SPEED FOR DATA
TRANSFER
Faster transfer speed
(>1Gbps)
Data transfer speed
(150Mbps)
MEDIUM THROUGH
WHICH DATA
TRANSFER OCCURS
Uses light as a carrier Uses radio spectrum
SPECTRUM RANGE Visible light spectrum
has 10,000 times
broad spectrum in
comparison to radio
frequency.
Radio frequency
spectrum range is
less than visible light
spectrum.
POWER
CONSUMPTION
Low medium
COST Cheaper than Wi-Fi
because free band
doesn’t need license
and it uses light
Expensive in
comparison to Li-Fi
because it uses radio
spectrum.
OPERATING
FREQUENCY
Hundreds of Tera
Hertz
2.4 GHz
SECURITY High secure Low secure

7. WORKING PROCESS
 Operational procedure is very simple. If the LED is ON; you transmit a digital 1, if the
LED is OFF, you transmit a 0.
 The LEDs can be switched on and off very quickly, which gives nice opportunities for
transmitting data. LED varies in intensity so fast that a human eye cannot detect it.
 Hence all that is required is some LEDs and a controller that code data into those
LEDs. We have to just vary the rate at which the LEDs flicker depending upon the data
we want to encode.
Thus every light source will work as a hub for data transmission.

8. IMPLEMENTATION:
 On one end, all the data from internet will be
streamed to a lamp driver when the LED is turned
ON; the microchip converts the digital data in form of
light. [Data from internet is used to modulate the
intensity of LED light source.]
 Thus, by fast and subtle variations of current, optical
output can be made to vary at extremely high speed.
 A light sensitive device (photo detector) receives the
signal and converts it back into original data. This
method of using rapid pulses of light to transmit
information wirelessly is technically referred as visible-
light communication.

9. APPLICATIONS
Li-Fi can be used in:
 Sensitive areas such as aircrafts for data transmission without causing interference.
 Places where it is difficult to lay optional fibers like operation theatres.
 Trafficscenarios, thereby reducing accidents.
 Underwater applications where radio waves cannot propagate.
 Industries like petrochemical plants [Petrochemical plants convert natural resources such
as crude oil, natural gas, ores and minerals into products for a wide range of applications],
nuclear power plants, petrol pumps, etc.
 Home & small offices
 Lecture/seminar halls

11. A PROVEN TECHNOLOGY
 Harald has demonstrated Li-Fi using an ordinary table
lamp, and a computer located below the lamp.
 He successfully transmitted data at speed exceeding
10Mbps using light waves from LED light bulbs.
 Also, he periodically blocked the beam of light, causing
the connection to drop.

12. ADVANTAGES
 Data rate greater than 10 gbps; Theoretically allowing HD film to be downloaded in 30
seconds.
 Can be used anywhere, even in RF restricted areas; Since light waves will not interfere with
radio waves.
 Mostly LED light bulbs are used, which consumes less energy. Hence cost efficient.
 As light waves cannot penetrate through walls, the data cannot be intercepted; Thus
provides secured communication unlike WI-Fi.
 Efficient alternative to radio based wireless; since it is quick and reliable.

13. LIMITATIONS
 Visible light cannot penetrate through solid objects.
 A major challenge of Li-Fi is how the receiving device will transmit back to transmitter.
 Interferences from external light sources like sunlight, in the path of transmission will cause
interruption in the communication.
 Data transmission can be easily blocked by any object placed in front of LED source.

14. CONCLUSION
Thus, if Li-Fi technology can be put into practical use, every bulb can be used as an alternative
to Wi-Fi hotspots. It provides simple, faster and efficient wireless data communication. Li-Fi
will make us to proceed towards the cleaner, greener, safer and brighter future.

15. Thank you!