Li-Fi

Presented by- Pratik Dave

History of Networks

In the olden days.

Wired networking.

Satellites Communications.

Wireless networking.

GENESIS OF Li-fi

Harald Hass, a professor at the University of Edinburgh who began his research in the field in 2004, gave a debut demonstration of what he called a Li-Fi prototype at the TEDGlobal conference in Edinburgh on 12th July 2011.

What is li-fi?

• 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.

• This varies in intensity faster than human eye can follow.• It is the fast and cheap wireless communication system which is

optical which is optical version of the Wi-Fi.

How LI-FI Works ? 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, which gives nice opportunities for transmitting data. Hence all that us required is some LEDS and a controller that code data into those LEDs.

Architecture OF Li-Fi

Concept -: operational procedure is very simple if the LED is ON, you transmit a digital 1’sif its OFF you transmit a 0’s. The LEDs can be switched ON and OFF very quickly, which gives nice opportunities for transmitting data.

Radio Waves

Infrared Rays

Visible Rays

Ultraviolet Rays X- Rays

Gama Rays

WHY ONLY VLC

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 bse used with low power.

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

Giga shower GIGA MIMOFor giga-speed technologies, the Li-Fi Consortium defined GigaShower, GigaSpot and GigaMIMO models

• LI-FI HAS AN UPPERHAND DUE TO PARALLEL DATA TRANSMISSION.

LI-FI VS WIFI (CONTD…)PART OF EM SPECTRUM THEY USE

• LI-FI USES THE VISBLE LIGHT PORTION OF THE EM SPECTRUM

• WIFI USE THE RADIOWAVE

PORTION OF THE EM SPECTRUM

ISSUES WITH RADIO WAVE

CAPACITY

• WITH THE ADVENT OF NEW TECHNOLOGIES LIKE 3G ,4G WE ARE RUNNING OUT OF SPECTRUM.

• THAT’S WHY RADIO WAVES ARE NOW BECOMING EXPENSIVE.

In Aircraft cabins

In RF restricted Environments

In Traffic lighting

DE-MERITS

• light can't pass through objects

• Connectivity while moving

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

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.