This document discusses Li-Fi technology, which uses visible light communication and LED bulbs to transmit data wirelessly. It works by varying the intensity of LED lights imperceptibly fast to transmit digital signals. Compared to Wi-Fi, Li-Fi provides higher data rates, more security since light cannot pass through walls easily, and uses the visible light spectrum which is not as congested as radio frequencies. Potential applications include use in hospitals, airplanes, and disaster management. While challenges include light not passing through objects and interference from other light sources, Li-Fi could help realize a cleaner, greener future with ubiquitous wireless connectivity.

1. LI-FI
TECHNOLOGY
FASTER WAY FOR WIRELESS DATA
TRANMISSION

2. CONTENTS
• Introduction
• What is Li-Fi
• Principle of Li-Fi
• How Li-Fi works
• Li-Fi vs Wi-Fi
• Applications
• Advantages
• Disadvantages
• Conclusion

3. INTRODUCTION
• Li-Fi (Light Fidelity )can be thought of as a
light-based Wi-Fi.
• Technology uses The Visible Spectrum.
• The term was first used by Harald Haas in his TED Global talk on Visible Light
Communication in 2011.
• In October 2011 a number of companies and industry groups formed the
Li-Fi consortium, to promote high-speed optical wireless systems.
• Researchers at the Heinrich Hertz Institute in Berlin, Germany, have reached
data rates of over 500 megabytes per second using a standard white-light
LED.

4. WHAT IS LI-FI???
• Li-Fi is a wireless optical networking technology
that uses light-emitting diodes (LEDs) 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 data is transmitted by the LED bulbs and received by photoreceptors.

5. HOW LI-FI WORKS??
• Li-Fi is implemented using white LED light bulbs at
downlink transmitter.
• By fast variations of the current, optical output can be
made to vary at extremely high speeds.
• An overhead lamp fitted with an LED with signal
processing technology streams data embedded in
its beam at ultra high speeds to the photodiodes.
• A receiver dongle then converts the tiny changes in
amplitude into an electrical signal, which is then
converted back into a data stream & transmitted
to a computer or mobile device.

6. PRINCIPLE OF LI-FI
• The heart of this technology is a new
generation high brightness LED’s.
• Visible Light Communication.
• These LED’s varies in intensity (that is gets on
and off) so fast that a human eye cannot detect it.
• If led is on , then we transmit a digital signal 1,and if the led is off , then we
transmit a digital signal 0.
• A controller is connected at the back side of these led bulbs to code data to
these LED’s.

7. WI-FI VS LI-FI
• Li-Fi can be thought of as a light-based Wi-Fi.
That is, it uses light instead of radio waves to transmit information.
• Instead of Wi-Fi modems, Li-Fi would use transceiver-fitted LED lamps that can
light a room as well as transmit and receive information.
• Wi Fi is great for general wireless coverage within building and Li Fi is ideal for
high density wireless date coverage in confined area and for relieving radio
interference issues.
• Li-Fi is almost 100 times faster then Wi-Fi.

8. APPLICATIONS
• Medical applications (in hospitals)
• Airlines
• Smarter Power Plants
• Under sea Awesomeness
• Disaster management
- It Could Keep You Informed and Save Lives

9. ADVANTAGES
• Li-Fi can solve problems related to the insufficiency of radio frequency
bandwidth because this technology uses Visible light spectrum that has still
not been greatly utilized.
• High data transmission rates of up to 10Gbps can be achieved.
• Since light cannot penetrate walls, it provides
privacy and security that Wi-Fi cannot.
• Low implementation and maintenance costs.
• Availability
• Efficiency

10. DISADVANTAGES
• Light can't pass through objects.
• A major challenge facing Li-Fi is how the receiving device will transmit back
to transmitter.
• Interferences from external light sources like sun, light, normal bulbs,
opaque materials.

11. CONCLUSION
• The possibilities are numerous and can be explored further.
• If his technology can be put into practical use, every bulb can be
used something like a hotspot to transmit wireless data and we
will proceed toward the cleaner, greener, safer and brighter
future.