This document provides an overview of Li-Fi technology. It discusses that Li-Fi uses visible light communication and LED bulbs to transmit data wirelessly. The document explains that Li-Fi is the optical version of Wi-Fi, transmitting data through light instead of radio waves. It operates by switching LED bulbs on and off very fast to send binary codes, and uses light sensors at the receiver end to convert the signals back to data. The document outlines some of the key advantages of Li-Fi such as using the light spectrum, enabling higher speeds than Wi-Fi, and addressing limitations of the radio spectrum.

2.  INTRODUCTION
 HISTORY
 PRESENT SCENARIO
 WORKING PROCESS
 LI-FI vs WI-FI
 APPLICATIONS
 ADVANTAGES
 DISADVANTAGES
 CONCLUSION

3.  Li-Fi stands for ‘Light Fidelity’.
 It is a VLC(Visible Light Communication), technology
developed by the scientist, Prof. Harald Hass at University of
Edinburgh
 Li Fi is now part of Visible Light Communication(VLC).
Li-Fi is typically implemented using white LED light bulbs”.
 These device are normally used for illumination by Appling
a constant current through the LED
 Li-Fi is the term have been used to label the fast and cheap
wireless communication system, which is the optical version
of Wi –Fi .
 Li-Fi is light based Wi-Fi that is, it uses light instead of radio
waves to transmit information

4.  LI-FI is the transmission of data through illumination
by taking the fiber out of fiber out by sending data
through a LED light bulb
 This varies in intensity higher than human eye can
follow
 It is fast and cheap wireless communication system
which is the optical version of Wi-Fi

6.  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 everyday life, private life,
business life as currently as 2G,3G,4G uses
Radio waves

7.  Heart of Li-Fi Technology is High brightness LED’s.
 The LED Bulbs will hold a Micro-chip that will do the
job of processing the Data.
 The ON-OFF activity of LEDs enables a kind of data
transmission using Binary codes
 Switching ON an LED is a Logical ‘1’;Switching it
OFF is a logical ‘0’.
 A Light sensitive device(photo detector) receives the
signal and converts it back into original data.

8. Operational procedure is very simple, if the
LED is ON, you transmit a digital 1,if its OFF
you transmit a 0.The LEDs can be switched on
and off very quickly, which gives nice
opportunities for transmitting data.Hence all
that 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
transmission

9.  LED
 Fluorescent Lamp

10.  Avalanche Photo Diode
 Image Sensors

16.  Overcomes the limitations of radio spectrum
 High speed of 10 Gbps can be achieved
 Li-fi can solve the for essential problems of
wireless communications these days