BY-ANOOP KUMAR E.C. (B.TECH) IIIrd year A.I.T.M.

Li Fi (Light Fidelity)

PERSENTATION ON

Introduction History Present scenario Woking process & principle Li-Fi vs Wi-Fi Applications Challenges for Li-Fi conclusion

Contents

What is Li-Fi ?Light-Fidelity

LiFi is a wireless optical networking technology that uses light-emitting diodes (LEDs) for data transmission.

INTRODUCTION

Introduction

LiFi data is transmitted by the LED bulbs and received by photoreceptors.

The technology truly began during the 1990’s in country like Germany,Korea and Japan where they dicovered LED’S could be retrofitted to send information. Harald Haas continues to wow the world with the potential to use light for communication.

Professor Harald Haas, from the University of Edinburgh in the UK, is widely recognised as the original founder of Li-Fi.

HISTORY

Li-Fi

Radio spectrum is congested but the demand for wireless data double each year. Every thing, it seems want to use wireless data but the capacity is drying up.

Present scenario

Issue regarding radio spectrum

Radio Spectrum

Capacity

Efficiency Security

Availability

used for Is not hospitals generally used Expensive, Is not used so far, due toLimited BW, Safe to use, Good for use, harmful effectLess secure Large BW but dangerous for low power applications due harmful for eyes

Elecrtromagnetic spectrum

Radio waves Infra red visible ultravoilet X-rays Gamma

rays

human body

WHO CAN REPLACE RADIO WAVES FOR WIRELESS COMMUNICATION ..?

LIGHT-FIDELITY

Li-Fi

Operational procedure is very simple, if led is on, you transmit a digital 1, if off you transmit 0. the LEDs can be switched on and off very quickly, which gives nice opportunities for transmitting data. Hence all that we require some LEDs and controller that code data into these LEDs

Thus every light source will work as a hub for data transmission.

Working process

How Li-Fi Works ?

On one end all data on the internet will be streamed to a lamp driver when the led is turned on the microchip converts the digital data in form of light.

A light sensitive device(photo detector) receives the signal and convert it back into original data. This method of using rapid pulses of light to transmit information wirelessly is technically referred as Visible Light Communication (VLC).

How Li-Fi Works ?

Wi-Fi 150 Mbps

Bluetooth 3 GbpsIrDA 4 Gbps

Fire wire 800 MbpsUSB 3.0 5 Gbps

Thunderbolt 20 Gbps

Wired

Wireless(Current)

Wireless(Future)

Li-Fi 10 Gbps

Giga-IR 1 Gbps

Wi-Gig 2Gbps

Comparison between Various Technologies

Wifi vs Li-fi

Li Fi technology is still in its infancy. However some area where it seems perfectly applicable.

1. TRAFFIC LIGHT Traffic light can communicate to The car with each other. Cars have LED-based cack lights, and car canCommunicate with each other andPrevent accident in by echangingInformation.

Application of Li-Fi

2.Intrinsically Safe Enviromnet :Visible Light is more safe than RF hence it can be used in plces where RF cant be used as petrochemical plants.

Application of Li-Fi

3. Airlines: Whenever we travel through airways we face the

problem in communication media because the whole airways communication are performed on the basis of radio waves to over come this drawback on radioways li-fi is introduced.

Application of Li-Fi

4. On ocean beds: Li-Fi can even work underwater were wi-fi

fails completely, thereby throwing open endless opportunities for military/navigation operations.

Application of Li-Fi

5. Street Lamps(as free access points): There are millions of street lamps deployed around the world and each of these street lamps could be used as a free hotspots.

Application of Li-Fi

Light can’t pass through objects.

Interference from external light source like sun light, normal bulbs, opaque material in the path of transmission will cause interruption in communication.

Li-Fi requires line of sight.

High installation cost of the VLC Systems.

Limitations & Challanges

The possibilities are numerous and can be explored further. If this technology can be put in to practical use, every bulb can be used something like a wi-fi hotspot to transmit wireless data.

Conclusion

The Future of wireless communication is LI-FI

ANY QUERIES….

Li-Fi: the next generation wireless communication

THANK YOU