What is Li-Fi Technology? How Does It Work? | Explained


Li-Fi is the abbreviation of the term Light Fidelity. So simply, we can say that Li-Fi technology is nothing but light-based Wi-Fi technology. As we know Wi-Fi is fully networked bi-directionally wireless communication technology where data is being transmitted using radio waves. While in the case of Li-Fi technology, the data is transmitted in the form of visible light using the LED light source.

So, the household LED bulbs and LED lamps which are used as a light source can also be used to transmit the data.


How Li-Fi technology works.

If you see any LED light source, if you provide the constant current to this LED bulb it provides the constant brightness.

So, as we change the current that is flowing through the LED bulb, the illumination or constant brightness. As we change the current that is flowing through the LED bulb, the illumination or brightness of this bulb will change.

This principle is used for transmitting the data wirelessly using this Li-Fi technology. So, if no current or minimum current is flowing through this LED bulb, then the brightness of this LED source will be minimum, and that will be treated as digital 0.

Digital 0 will be transmitted at the receiver side. Similarly, when the light bulb is ON, or we can say that if the maximum amount of current is flowing through this LED bulb then the illumination or brightness of the LED bulb will be maximum and that will be treated as digital 1.

So, wherever the LED is ON, so digital 1 will be transmitted at the receiver side. In this way, by flickering the LED light source very rapidly we can transmit the data in the form of 1s and 0s to the receiver. If this flickering is happening a million times per second, then we cannot see this flickering with our naked eyes, and we can treat this LED bulb source as a normal regular bulb source.

The data which is coming from the webserver or the internet first will go to the MODEM, which provides the necessary modulation to the incoming data stream.

. Then this modulated data is fed to the LED driver, which changes the driving current for this LED bulb according to the incoming streaming data, at the receiver end, the optically received data is first converted into the electrical signal using the photoreceiver or photodiode, and after the signal conditioning, this data is being fed to the computer or laptop.

So to receive this incoming data, on the receiver side we require the Li-Fi dongle.  Li-fi dongle consists of a photoreceiver as well as an IR transmitter.

This Infrared Transmitter can be used to transmit the uplink data back to the LED source. Now one such company which provides a complete Li-Fi solution is pureLi-Fi, which generally makes these Li-Fi dongles.


Advantages of Li-Fi technology

Advantages of Li-Fi technology over the other wireless communication technologies, these are some advantages of Li-Fi technology;

  1. Speed

So far researchers have achieved the speed up to 1 - 10 Gbps in the lab-scale prototype, and this speed can further be enhanced by using the array of LED sources the multiple colors of LEDs like RGB LEDs where each LED source can transmit the data up to the 10Gbps.

So, using such technologies, the researchers have achieved a maximum speed of up to 100Gbps. If we compare it with 4G/LTE (Long Term Evolution) or particular the LTE advanced, the maximum achievable speed under this LTE advanced is 1Gbps for the station user and 100 Mbps for the mobile user.

But all these speeds are theoretically achievable maximum speeds, but maybe much lesser compared to this theoretically achievable maximum speed which is around (40 -  50 Mbps)

  1. Security

Li-Fi is more secure than other wireless technologies because light can be contained in physical space. Our doors and windows can be shut, and physical barriers and adjustments can be implemented to contain and project the light.

  1. Congestion free


Applications of Li-Fi Technology

  1. Hospital

Li-fi technology can be used in hospitals since it provides very high-speed internet communication, so real-time monitoring of the patient will be possible.

  1. Underwater communication
  2. Can be used in the airplanes to provide the internet to the passengers



For the world of IoT (Internet of Things) we require more Li-Fi than Wi-Fi because the speed provided by Wi-Fi is insufficient.

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