LiFi is a visible light communication technology that uses light from LED bulbs to transmit data. It works by varying the intensity of light faster than what the human eye can perceive. The light can be detected by a photodiode that converts light signals into electrical signals to transmit data such as text, audio, video wirelessly. LiFi has applications in traffic lights, hospitals, airlines, offices and provides advantages such as larger bandwidth and energy efficiency compared to traditional WiFi. However, it also has disadvantages like not working in darkness and light not passing through objects.

1. RAJIV GANDHI UINIVERSITY
OF KNOWLEDGE AND
TECHNOLOGIES
LiFi

2. TABLE OF CONTENTS
 Abstract
 Introduction of Li-Fi
 Block diagram
 Working principle
 Applications
 Advantages

3. ABSTRACT
 Li-Fi technology means Light Fidelity technology .
 It was proposed by Harald Hass in july 2011.
 As the name suggests, LiFi is a data transmission
technique which use light as a medium of
communication.
 LiFi is a Visible Light Communication (VLC) based
technology.

4. INTRODUCTION
 Li-Fi is transmission of data through
illumination i.e. sending data through
a LED bulb that varies in intensity faster
than human eye can follow
 If the LED is on a digital 1 is transmitted, if
the LED is off then a digital 0 is transmitted
 Li-Fi is a light based Wi-Fi it uses light

5. BLOCK DIAGRAM

6. WORKING PRINCIPLE
Fundamental principle:
Generally flickering lights are annoying but
when they are made to flicker at a very fast
speed which our human eye cannot detect
they can be very useful.
*The amplitude of the light is varied at very
high speed which creates an impression

7. Y
The main components of this communication
systems are:
>> A high brightness white LED, which
act as a COMMUNICATION SOURCE
>> A SILICON PHOTODIODE which shows
good response to Visible wavelength
region serving as the RECEIVING ELEMENT.
* Any LED light set if used along with a microchip
inside it can

9. t
* This is like sending a morse code Signal
using a torch but at a very fast speed.
* This very high speed blinking of the light enables
the
source to transmit data in a rapid stream of binary
code that, although invisible to the naked eye,can
be
detected by a light sensitive device.
* Thus every light emitting source can be used as a

10. * On one end all the data on the internet will be
streamed to a lamp driver.
* When the LED is turned on the microchip converts this
digital data in the form of light.
* On the othe end this is light is detected by photo
sensitive devices.
* Next this light is amplified and processed and then fed
to the device.

11. APPLICATIONS
* Traffic lights
* Hospitals
* On Oceans Beds
* Airlines
* Offices
* Product Retailing

12. >> Larger
bandwidth
ADVANTAGES

13. >> LIFI doesn’t work in the dark.
>> Light doesn’t pass through the
object.
>> High installation cost of the
DISADVANTAGES

14. * To overcome the limitations of the
RADIO spectrum.
* With its magic of light it can make
our world a greener,
safer,cleaner and moreover a
CONCLUSION