Li-Fi (light fedility)

PRESENTATION ON LIFI (LIGHT FEDILITY) PRESENTED BY D.PUNYA SANDEEP& CH.SRI RAMA KRISHNA SACET,CHIRALA

CONTENTS

INTRODUCTION WORKING COMPARISION ADVANTAGES DISADVANTAGES APPLICATIONS

INTRODUCTION

WHAT IS LI-FI?? LI-FI is transmission of data through illumination ,sending data through a

LED light bulb.

LI-FI comes under VLC(VISIBLE LIGHT COMMUNICATION)

INTRODUCTION

HISTORY The technology truly began

during the 1990's in countries like Germany, Korea, and Japan where they discovered LED's could be retrofitted to send information.  Harald Haas continues to wow the world with the potential to use light for communication.

WORKING

How LI-FI works? 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 us required is some LEDS and a controller that code data into those LEDs.

Working principle

Transmission element

Signals from the data input is modulated to intensity of light.

Transmission side simply contains an led lamp which transmits the modulated light signals.

This led lamp contains a series of LED’s which proto fits according to the input given .

Receiving element

Receiving elements are “AVALANCHE PHOTO DIODE” and image sensor.

Avalanche photo diode is responsible for converting the light signal into electrical signal and further the procedure is carried out by image sensor.

illustration

COMPARISIONWHY VLC??

o Gama rays cant be used as they could be dangerous.

o X-rays have similar health issues.

o Ultraviolet light is good for place without people, but other wise dangerous for the human body.

o Infrared, due to eye safety regulation, can only be used with low power.

DIFFERENCE B/W TECHNOLOGIES

TECHNOLOGY SPEED

Fire wire 800 Mbps

USB 3.0 5 Gbps

Thunder bolt 20 Gbps

Wi-Fi 150 Mbps

Bluetooth 3 Mbps

IrDA 4 Mbps

Wi-Gig 2 Gbps

Giga-IR 1Gbps

Li-Fi >10 Gbps

APPLICATIONS

Used in traffic lights which can communicate with cars to avoid accidents.

Used in airlines: Generally in airlines mobile phones can’t be used as they can effect the radars which are main way of communication.

Used in power plants for faster data exchange.

Underwater communications. (rare)

ADVANTAGES

Availability

Efficiency

High security

Easy to use

Fast data transfer

Harmless

Low-cost

DISADVANTAGE

However, everything comes with a disadvantage. The major disadvantage here is the fact that these signals cannot penetrate walls. So if you want to move from one room to another, you will need to have a wired bulb present in that room as well!

CONCLUSION

The possibilities are numerous and can be explored further. If this 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.