Li-Fi or Light Fidelity is a technology for fast and cheap wireless-communication system based upon light. The term was first used by Harald Haas. In this technology, Light Emitting Diodes are used to transmit data wirelessly.

How does it work?

Li-Fi uses LEDs and ‘visible’ light to transmit data through the air as an alternative to short-range radio.

LiFi is transmission of data through illumination by sending data through a LED light bulb that varies in intensity faster than the human eye can follow.

Thus, Li-Fi is the optical version of Wi-Fi.

At the heart of this technology is a new generation of high brightness light-emitting diodes. Very simply, if the LED is on, you transmit a digital 1, if it’s off you transmit a 0. They can be switched on and off very quickly, which gives nice opportunities for transmitted data.

By switching LED that is fitted with a microchip on and off several thousand times a second, it is able to transmit information. The data is encoded by a light sensitive receiver on the receiving device which picks up the signal and converts it back into data.

It is possible to encode data in the light by varying the rate at which the LEDs flicker on and off to give different strings of 1s and 0s.The LED intensity is modulated so rapidly that human eye cannot notice, so the output appears constant.

Opportunities in Li-FI:

  • Since this technology is based upon light, it’s a free band which does not need a license. Obviously it would be cheaper than Wi-Fi. Then, the visible light spectrum is 10 thousand times larger then the Radio spectrum and thus is NOT a scare resource.
  • Since Optical waves don’t pass through the walls, it could be used as a secured communication
  • The speed of communication can be very high; theoretically it can be 1GB per second.
  • Light does not interfere with various applications in aviation, medical science etc. For example, in operating rooms, Wi-Fi is not allowed at many places. Similarly, Wi-Fi can interfere with the communication used in aviation.

Challenges with Li-Fi

  • Li-Fi requires line of sight, when set up outdoors, the apparatus would need to deal with ever-changing conditions.
  • The major challenge is that how the receiving device would transmit the data back to the sending device.

Potential Applications of Li-FI 

  • Li-Fi can be used in places where it is difficult to lay optical fibres.
  • It can be suitaby used in operation theatres
  • It can be used at traffic signals whereby it can communicate with the led of the lights in cars thus controlling traffic.
  • It can be used for data transmission in aircraft

It can be used in Petroleum and chemical plants because light is not hazardous as spectrum in these plants.

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