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  • Writer's pictureDebarghya Basu

Li-Fi Project: Data Transmission Through Light

What is Li-Fi?

  • Li-Fi stands for Light Fidelity and works onVisible Light Communications (VLC) system.

  • Harald Hass in a TED Talk in 2011 demonstrated this new Li-Fi can fully replace Wi-Fi.

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

How does Li-Fi work?

  • Just like Wi-Fi uses radio waves, Li-Fi uses visible light spectrum to transmit data. Li-Fi works by very fast modulation of intensity of light emmitted by an LED which can’t be noticed by human eye.

  • Operational procedure is very simple –

    • if intensity is high, it transmits a digital 1

    • if its low it transmits a 0.

All you need is some LED and a controller .

  • The LED light source acts as a Li-Fi router having specific IP address. The LED remain connected to a server. Any device under that light can access the internet.

Our Model Circuit

This is how real Li-Fi works

Benefits of Li-Fi over Wi-Fi

  • High speed(about 100 Gbps in lab environment)

  • Secure from any hacking attacks

  • No harmful radiations

  • Underwater data transmission

Applications of Li-Fi

  • Every light post can serve as an internet hotspot. Moreover automatic cars can communicate amongst themselves for a safer ride.

  • Places like petrochemical industries and hospitals where radio frequency can’t be used Li-Fi can be a safer choice.

  • Li-Fi can be used in airlines without affecting airways communication.

  • Li-Fi can even wok underwater were Wi-Fi fails completely, thereby throwing open endless opportunities for military and navigation operations.

Some Images and Video of the Project

Project Cost

  • LED -> Rs 7

  • Switch -> Rs 10

  • Resistor (100 ohm) -> Rs 2

  • Audio Jack -> Rs 0 (reused from scrap earphone)

  • Battery (9V-500mAh) -> Rs 15

  • Solar Panel (3W) -> Rs 150 (from AlienSolar)

  • Socket (Aux) -> Rs 15

Total project cost Rs 199.

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 hotspot to transmit wireless data and we will proceed toward the cleaner, greener, safer and brighter future.


They are the engineering students of Techno India, Salt Lake, Kolkata.


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