LI-FI –VISIBLE LIGHT THROUGH WIRELESS COMMUNICATION

BY- Vrushikesh Bhosle

Jeslin Armstrong

Surabhi Kate

Abhishek Patil

WHAT IS LI-FI ? LI-FI (Light Fidelity) can be thought of as a light based Wi-Fi. This technology uses the visible spectrum. LI-FI is transmission of data through illumination, sending data

through a LED light bulb that varies in intensity faster than human eye can follow.

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 data.

PRINCIPLE OF LI-FI TECHNOLOGY The heart of this technology is new

generation high brightness LED’s. These LED’s varies in

intensity,that is gets on and off. Operational procedure is very

simple,if the LED is on you transmit a digital 1,if its off you transmit a digital 0.

The LED’s can be switched on and off very quickly which gives nice opportunities for transmitting data.

Hence all that we require is some LED’s and a controller at the back side of these bulbs that code data into those LED’s.

HOW IT WORKS ? LI-FI is implemented using white LED bulbs at downlink

transmitter. By fast variations of the current, optical output can be made to vary

at extemely high speed. An overhead lamp fitted with an LED with signal processing

technology streams data embedded in its beam at ultra high speeds to the photodiodes.

A receiver dongle then converts the tiny changes in amplitude into an electrical signal, which is then converted back into a data stream and transmitted to a computer or mobile devices.

BLOCK DIAGRAM OF LI-FI

Why only VLC

LI-FI is based on visible light communication. The visible light communication is a data communication technique using

visible light between 400THz and 800THz as optical carrier for data transmission.

Gamma rays, X-rays, Ultraviolet rays are harmful for the human body. Infrared rays are also dangerous, due to eye safety regulations and can

only be used with low power. Radio waves are expensive and they are less secure. Hence we are left only with the VISIBLE LIGHT SPECTRUM which is

not harmful for humans.

ADVANTAGES Bandwidth Availability Efficiency Harmless High security Ease of use Fast data transfer (10 Gbps) Low cost

POTENTIAL APPLICATION OF LI-FI

TRAFFIC LIGHTS PUBLIC INTERNET HOTSPOTS

POTENTIAL APPLICATION OF LI-FI

UNDERWATER INTERINSICALLY SAFE ENVIRONMENT

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