Internet by light is possible. Discover the secrets of future connectivity by learning how LiFi works. LiFi, an acronym for Light Fidelity, is a visible light communication (VLC) technology. In other words, where traditional technologies (WiFi, 5G…) use the radio part of the electromagnetic spectrum, LiFi relies on the use of its optical part. This innovation offers an alternative to current technologies by providing a high-speed Internet connection, stable, without latency and without radio frequency waves. Far from being a simple idea, LiFi has already 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
LiFi signal transmission
Data transmission via LiFi is done through a light beam emitted by an LED bulb and directed to a receiving device. This bulb is equipped with a LiFi router, which we call an access point, connected to the Internet network via an RJ45 Ethernet cable with PoE capability. The information is sent to the router from the network as an electrical signal, and then encoded by the imperceptible and ultra-fast switching (light intensity variation) of the light source.
LiFi signal reception and processing
The connected device (computer, smartphone, tablet) equipped with a LiFi key and located in the coverage area of the light beam receives the data transmitted by the router through its LiFi receiver. This device, which can be a dongle 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:
- The LiFi router receives the information via the Ethernet cable that connects it to the local network
- It transmits it to the LED bulb, which fluctuates at high speed, with a frequency of tens of thousands or even millions of signals per second.
- The light signal is perceived by the LiFi key which transforms it into an electrical signal and transmits it to the computer
- The computer translates the signal into information that can be understood by humans.
To allow the user to browse the Internet, the LiFi system must work in a bi-directional way, which means that the connected device (or rather the associated LiFi key) must be able not only to receive data, but also to transmit it. This implies that the receiving device is equipped with two photodiodes, one to transmit and one to receive information, and that the transmitting device is equipped with a receiver. Ultra-fast, reliable and secure, the LiFi connection is becoming very popular. Already used in the transportation, aeronautics and education sectors, this solution aims to offer optimal connectivity where radio waves are not desirable (interference, cybercrime, electromagnetic pollution…).