TECHNOLOGY

LI-FI

A.Rejoice Anton &V.Prem Kumar

By

II Year – CSE DepartmentVaigai College of EngineeringMadurai

INTRODUCTION

Internet services are very highly demanding and essential accessories in current situation. Presently we are utilizing the wired networks and mostly wireless networks like Wi-Fi in our houses, offices, shops, hotels, college campus and around 10-100 meter distances to connect our P.C., Laptops, mobile phones. As present paper tells about the newly introduced Li-Fi technology network which is based the visible light communication that provide a fast data speed about greater than 10 Gbps.

HISTORY OF NETWORKS In the olden days, People formed a network in order to

transmit a piece of data from one place to another. With the advances in technology a new networking was

developed using wires as a medium ( wired networking ).

As time passed the technology increased and we launched satellites into space and thus were in a position to transmit enormous amount of data across various geographical location.

Wireless networking gained a wide recognition and become the most popular of all networks ( example ): Wi-Fi.

As technology keep on developing , the latest wireless network LI-FI is introduced to overcome disadvantages of radio frequency communication.

PRESENT WIRELESS COMMUNICATION

1.4 Million

5 Billion

PRESENT WORLD

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

Available within the range of Base stations

Limited availability

Unavailable in aircrafts

Less secure (passes through the walls)

Cost and Expensive

Less bandwidth compared to other spectrums

Harmful to humans health

ISSUES REGARDING RADIO-SPECTRUM

WHAT IS LI-FI ?

LI-FI ( Light-Fidelity ) is transmission of data through illumination ,sending data through a LED light bulb that varies in intensity faster than human eye can follow.

HISTORY OF LI-FI

Harald Haas

A German Physicist, Dr.Harald Haas a professor in university of Eddinburgh who began his research in the field in year 2004.

In 12th July 2011,He first introduced to the world this new technology Li-Fi in TED Global conference in Eddinburgh UK.

TED GLOBAL CONFERENCE

HOW LI-FI WORKS ? The operation procedure is very simple, if

the LED is on, you transmit a digital 1, if it's off you transmit a digital 0.

They can be switched on and off very quickly, which gives nice opportunities for transmitting data.

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.

Transmitting elementReceiving element

Visible light communication ( VLC ) is a potential solution to the global wireless spectrum shortage.

Li-Fi technology is based on Visible Light communication.

VLC is a data communication medium, which uses visible light between 400 THz and 800THz as optical carrier for data transmission and illumination.

It uses fast pulses of light to transmit information wirelessly.

VISIBLE LIGHT COMMUNICATION

WHY ONLY VLC?Radio Waves

Infrared Rays

Visible

Rays

Ultraviolet Rays

X- Rays

Gama Rays

Gama rays cant be used as they could be dangerous.

X-rays have similar health issues.

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

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

HENCE WE LEFT WITH THE ONLY THE VISIBLE – LIGHT SPECTRUM.

DIFFERENCE BETWEEN TECHNOLOGIES

APPLICATION

S

RF RESTRICTED ENVIRONMENTS

AIRCRAFT CABINS

APPLICATIONS

TRAFFIC SYSTEM

PUBLIC INTERNET HOTSPOT

ADVANTAGES …. Larger bandwidth ( 10,000 times the radio bandwidth )

High speed data rate

High efficiency

Highly secure

Works even under water in sea

Safe for health

More availability

Low cost solution

DISADVANTAG

E “ Presence of Light is Essential ’’

CONCLUSION The possibilities are numerous and can be explored further. If this technology can be put into practical use, every bulb can be used as Li-Fi access point to transmit wireless data and

we will proceed toward the cleaner, greener, safer &

brighter future ! This may solve issues such as the shortage of radio frequency bandwidth and also internet where radio based wireless isn’t allowed such as aircraft, Hospitals, etc…

REFERENCES GoogleWikipedia Lifeconsortium.orgNewtecarticles.comSeminarprojects.comIrjcjournals.org extremetech.com