Saturday, 17 September 2016

Li-Fi Technology – A New Generation Communication Technology


In layman’s terms, Li-Fi is a wireless optical networking technology that uses light-emitting diodes (LEDs) for data transmission. Li-Fi is designed to use LED light bulbs similar to those currently in use in many energy-conscious homes and offices. However, Li-Fi bulbs are outfitted with a chip that modulates the light imperceptibly for optical data transmission. Li-Fi data is transmitted by the LED bulbs and received by photo receptors.



The term Li-Fi is an abbreviation for Light Fidelity and it was coined by German Physicist Harald Haas who introduced the technology in 2011 at a TED Talk in Scotland.

How Li-Fi Works?

Li-Fi uses light from LEDs, instead of radio waves as in the case of Wi-Fi, to send information in the form of binary data. This binary data is received by the receiver equipped with decoder that decrypts the data and triggers actions in your smart device. Let's simplify this a little - Li-Fi works much like the infrared technology in your television. Infrared works on a simple principle: a command is given e.g. “change channel” when you press a button on your remote control and that input is turned into binary code. The code is then transmitted via infrared light waves by your remote’s sensor, and the light waves are received by your TV’s infrared sensor, which decodes the light and performs the intended action. In case of Li-Fi , LED bulbs transmit the data by modulating the light waves while a photodetector on your phone or laptop picks up those light waves and decodes them.



Advantages of Li-Fi:

  • Higher speeds than Wi-Fi.
  • 10000 times the frequency spectrum of radio.
  • More secure because data cannot be intercepted without a clear line of sight.
  • Prevents piggybacking.
  • Eliminates neighboring network interference.
  • Unimpeded by radio interference.
  • Does not create interference in sensitive electronics, making it better for use in environments like hospitals and aircraft.

Drawbacks of Li-Fi:
  • The main issue of LiFi is that it cannot pass data signals through a wall unlike WiFi does, because light cannot pass through a wall. Not only this, if anything blocking a LED bulb, these will also some interference in internet connection. Figure below demonstrates the Mobile Data e.g. 3 G / 4G, Wi-Fi and Li-Fi and their coverage area. Thus Li-Fi has limited coverage only in the room where LED is glowing.




  • Other lighting sources could interfere Li-Fi network especially when we are in an open room where light come from outside, then there are fair chance of interruption.

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