Li-Fi, or light fidelity, is a wireless optical networking technology that uses LEDs for data transmission by modulating light intensity imperceptibly. It offers high data rates exceeding 10 Gbps and greater security compared to Wi-Fi, as light cannot penetrate walls. However, challenges include the requirement for a direct light source and potential interference from external light, limiting its current applicability.

1. LI-FI Sai kumar

2. How Li-Fi works ?
Real Time Usage of Li Fi & Comparison
Applications
Advantages and disadvantages
Introduction

3. INTRODUCTION
1. Li-Fi is light fidelity.
2. Li-Fi is a wireless optical networking technology that uses light-emitting diodes (LEDs) for data
transmission.
3. Li-Fi is transmission of data through illumination, i.e., by sending data through a LED light bulb
that varies in intensity faster than human eye can follow.
4. However, Li-Fi bulbs are outfitted with a chip that modulates the light imperceptibly for optical
data transmission.
5. Li-Fi data is transmitted by the LED bulbs and received by photoreceptors.

4. HISTORY
1. Professor Harald Haas, from the University of Edinburgh in the UK, is widely recognized as the
original founder of Li-Fi.
2. He coined the term Li-Fi and is Chair of Mobile Communications and co- founder of pure Li-Fi.
3. Haas promoted this technology in his 2011 TED Global talk and helped start a company to market it.
4. In October 2011, companies and industry groups formed the Li-Fi Consortium, to promote high-
speed optical wireless systems.
5. The first Li-Fi smartphone prototype was presented at the Consumer Electronics Show in Las Vegas
from January 7–10 in 2014.

5. HOW LI-FI WORKS?

6. ARCHITECTURE

7. ELECTROMAGNETIC SPECTRUM

8. CONT.
1. Gama rays cant be used as they could be dangerous.
2. X-rays have similar health issues.
3. Ultraviolet light is good for place without people, but other wise dangerous for the
human body.
4. Infrared, due to eye safety regulation, can only be used with low power.

9. REAL TIME USAGE OF LI-FI

10. EVOLUTION OF DATA SHARING

11. COMPARISON BETWEEN VARIOUS TECHNOLOGIES
Wi-Fi 150 Gbps
Bluetooth 3 Mbps
IrDA 4 Mbps
Fire wire 800 Mbps
USB 3.0 5 Gbps
Thunderbolt 20 Gbps
Li – Fi >10 Gbps
Giga - IR 1 Gbps
Wi - Gig 2 Gbps
Wired
Wireless
(current)
Wireless
(Future)

12. HOW IT IS DIFFERENT?
1. Li-Fi technology is based on LEDs for the transfer of data.
2. The transfer of the data can be with the help of all kinds of light, no matter
the part of the spectrum that they belong.
3. That is, the light can belong to the invisible, ultraviolet or the visible part
of the spectrum.

13. WI-FI VS LI-FI
Li-Fi Wi-Fi
It uses light for data transmission It uses radio waves to transmit information.
It requires LED lamp It requires modems
Li Fi is ideal for high density wireless date
coverage in confined area
Wi Fi is great for general wireless covrage within
building
Fastest transfer speed ( >1 Gbps ) Transfer speed 150 Mbps
High installation cost Low installation cost

14. APPLICATIONS
1. You Might Just Live Longer
2. Airlines
3. Smarter Power Plants
4. Undersea Awesomeness
5. It Could Keep You Informed and Save Lives

15. ADVANTAGES OF LI-FI
1. 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.
2. High data transmission rates of up to 10Gbps can be achieved.
3. Since light cannot penetrate through walls, it provides privacy and security that Wi-Fi
cannot.
4. Li-Fi has low implementation and maintenance costs.

16. DISADVANTAGES
1. Light can't pass through objects.
2. It can not be achieved without a light source
3. A major challenge facing Li-Fi is how the receiving device will transmit back to
transmitter.
4. High installation cost of the VLC systems.
5. Interferences from external light sources like sun, light, normal bulbs, opaque materials.

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