How LiFi works, step by step

Internet by light, it’s possible. Discover the secrets of future connectivity by learning how LiFi works. 

LiFi, which is for Light Fidelity, is a visible light communication (VLC) technology. In other words, where traditional technologies (WiFi, 5G, etc.) use the radio part of the electromagnetic spectrum, LiFi relies on the use of its optical part.

This innovation presents itself as an alternative to current technologies by offering a highspeed Internet connection, stable, without latency and radio frequency waves. Far from being a seductive idea, LiFi has proven its performance and security in many sectors. To better understand how light is the future of connectivity, find out how LiFi works.

How LiFI works

Transmitting the LiFi Signal

Data tarnsmission via LiFi is done through a beam of light emitted by an LED bulb and directed to a receiving device. This bulb is equipped with a LiFi router, which we call Access Point, connected to the Internet network by an RJ45 Ethernet cable with PoE capability. The information is sent to the router from the network as an electrical signal. It is encoded by the invisible and ultra-fast switching (light intensity variation) of the light source.

Receiving and processing the LiFi signal

The connected device (computer, smartphone, tablet) equipped with a LiFi key located in the light beam’s coverage area receives the data emitted by the router through its LiFi receiver. This device, which can take the form of a dongle to be connected to the device or an integrated chip, contains a photodiode responsible for capturing the light signal and a processor that converts it into an electrical signal. The computer receives this electrical signal and translates it into a binary system, then demodulates the digital data which then takes its final form, that of information understandable by humans.

How LiFi works in brief

Here is a summary of the LiFi operating process in 4 steps:

1. The LiFi router receives the information via the Ethernet cable that connects it to the local network
2. It transmits it to the LED bulb which fluctuates at high speed, at a frequency of several tens of thousands or even millions of signals per second
3. The light signal is perceived by the LiFi key which transforms it into an electrical signal and transmits it to the computer
4. The computer translates the signal into information understandable by humans.

The LiFi system must work bi-directional; for the user to browse the Internet, the connected device (or rather the associated LiFi key) must be able to receive and transmit data. That implies that the receiving device must be equipped with two photodiodes, one for transmitting and one for receiving information. The transmitting device must be equipped with a receiver.

Ultra-fast, reliable and secure, the LiFi connection is on its way to becoming very popular. Already in use in the transportation, aeronautics and education sectors, this solution aims to offer optimal connectivity wherever radio waves are not desirable (interference, cybercrime, electromagnetic pollution…).