LIFI TECHNOLOGY

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INTRODUCTION

LI FI- LIGHT FIDEALITY

Li-Fi is the transmission of data through

illumination, by taking the fiber out of fiber

optics by sending data through a LED light

bulb.It’s the same idea behind infrared remote

controls but far more powerful.

HISTORY

This technology was invented by

German Physicist “HARALD

HASS”, from the university of

Edinburgh, U.K.

He demonstrated it in the year

2012.

He explained Very simple, if the

LED is on, you transmit digital 1;if

it’s off you transmit a 0.

PRESENT SCENARIO

1.4 Million 5 Billion

The demand for wireless data is double each year. Everything,

wants to use wireless data but the capacity is drying up.

So ,What can carry this excess demand in

this Future??

WHAT IS LIFI?

Li-Fi is the transmission of data through illumination

by taking the fiber out of fiber optics by sending data

through a LED light bulb.

The intensity of LED bulb varies Faster than human

eye can follow.

It is the fast and cheap wireless communication system

which is optical version of the Wi-Fi.

HOW LI-FI WORKS

Working 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.

We have to just vary the rate at which the LED’s flicker depending upon the data we want to encode.

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

HOW LI-FI WORKS..

HOW LI-FI WORKS..

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 the digital data in form of light.

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

WHY ONLY VLC??

VLC is a data communication medium, which uses the visible

light between 400 THz (780 nm) and 800 THz (375 nm) as optical

carrier for data transmission.

WHY ONLY VLC..??

Gamma rays are radioactive and are dangerous.

X-rays have similar health issues.

Ultraviolet light is good for place without people,but

other wise dangerous for the human body.

IR Waves are harmful for our eyes hence can’t be used.

Radio Waves

Infrared Rays

Visible Rays

Ultraviolet Rays

X- Rays Gama Rays

CONSTRUCTION OF LIFI

Li-Fi consists of 3 main primary assemblies:

1. Bulb

2. Power amplifier ciruit (PA)

3. Printed circuit Board(PCB)

4. Aluminum enclosure

CONSTRUCTION OF LIFI..

The PCB controls the electric inputs and outputs

of the lamp and houses the microcontroller used

to manage different lamp functions.

An RF (Radio-Frequency) signal is generated by

the solid-state PA and is guided into an

electronic field about the bulb.

CONSTRUCTION OF LIFI..

The high concentration of energy in the electric

field vaporizes the contents of the bulb to a

plasma state at the bulb’s center; this controlled

plasma generates an intense source of light.

All of these sub-assemblies are contained in an

aluminum enclosure.

COMPARISON BETWEEN LIFI AND OTHER TECHNOLOGY

Technology Speed Data density

Wireless

Bluetooth 3Mbps *

IrDA 4Mbps ***

Wi-fi 150Mbps *

Li-fi 1Gbps ****

Giga-IR 1Gbps ***

Wi-Gig 2Gbps **

APPLICATIONS AREAS

1.Traffic Areas: Traffic lights can communicate to

the car and with each other. Cars

have LED-based headlights, By using

this lights, the cars can communicate

with each other and prevent accidents

in by exchanging information.

APPLICATIONS AREAS..

2.RF Restricted Enviroment:

Visible Light is more safe

than RF, hence it can be used in

places where RF can't be used

such as petrochemical plants .

APPLICATIONS AREAS..

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 overcome this drawback

on radioways,li-fi is introduced.

APPLICATIONS AREAS..

4.Underwater

communication: Li-Fi can even wok underwater

were Wi-Fi fails completely, thereby

its very much useful for

military/navigation operations.

ADVANTAGES OF LIFI

Li-Fi never gives side effect on any living thing.

It does not require any band width spectrum.

Any lightings device is performed as a hotspot.

Can be used underwater without radio

interference because salt conducts electricity.

DISADVANTAGES OF LIFI

Presence of light is essential.

There should be line of sight

Works better with fluorescent light and LEDs but very low efficiency with bulbs.

Interferences from external light sources like sun light, normal bulbs, and opaque materials in the path of transmission will cause interruption in the communication.

High installation cost of the VLC systems.

CONCLUSION

If this technology can be put into practical use , every bulb can be

used something like a Wi-Fi hotspots to transmit wireless data.

LIFI

ANY QUERIES??

LIFI

THANK YOU