A

T E C H N I C A L

P R E S E N T A T I O N

O N

TECHNOLOGY

BY: SATYAKI BANERJEE (ROLL N0: 77) SAYAN CHATTERJEE (ROLL NO: 80) DEPT.: ECE-2 YEAR: 3RD YEAR, 2ND SEMESTER

CONTENTS

Introduction

History OF LI-FI

Graphical Representation of LI-FI

Radio Spectrum

Issues Regarding Radio Spectrum

Electromagnetic Spectrum

Working Principle

Working Procedure

Comparision between LI-FI & WI-FI

LI-FI vs WI-FI

Applications

Drawbacks & Limitations

Future Aspects

Conclusion

INTRODUCTION

Li-Fi (Light-Fidelity) is transmission of

data through illumination, sending data

through a LED light bulb that varies

intensity faster than human eye can

follow.

HISTORY OF LI-FI

The technology truly

began during the 1990’s

in the countries like

Germany, Korea and

Japan where they Prof. Harald Haas, University of Edinburgh

discovered LED’s could be retrofitted to send

information. Harald Haas continues to wow the

world with the potential to use light for

communication.

GRAPHICAL REPRESENTATION OF LI-FI

RADIO SPECTRUM • Radio Spectrum is the part of the electromagnetic

spectrum corresponding to radiofrequencies i.e., frequencies lower than around 300 GHz. Electromagnetic waves in this frequency range, called radio waves, are used for radio communications.

• Radio Spectrum is congested but the demand for wireless data doubles each year.

ISSUES REGARDING RADIO SPECTRUMS

ELECTROMAGNETIC SPECTRUM

WHY ONLY VLC?

BIG QUESTION?

WHO CAN REPLACE

RADIO WAVES FOR

WIRELESS

COMMUNICATION?

ANSWER

WORKING PRINCIPLE

• 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.

• Every LED light source

will work as a hub of data transmission.

WORKING PROCEDURE

BASIC DIFFERENCES BETWEEN LI-FI AND WI-FI

LI-FI vs WI-FI

APPLICATIONS

Traffic Lights

Intrinsically Safe Environment

Hospitals (In Few Medical Equipments)

Airlines

On Ocean Beds

Street Lamps

DRAWBACKS & LIMITATIONS

Light can’t pass through objects.

Li-Fi requires line of sight.

High installation cost of the VLC systems.

Interferences from the external sources

of light in the path of transmission will

cause interruption in the communication.

A major challenge which Li-Fi faces is how

the receiving device will transmit back to

transmitter.

FUTURE ASPECTS

At the rate we currently adopt wireless

data, we will ultimately run out of radio

spectrum as we cope with the long-term

demand of wireless data transmissions and

the trillions of bytes of data communicated

every month. So Li-Fi will be the only

option which will be left for data

transmissions.

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 hotspots to

transmit wireless data.

THANK YOU!