What is Li-Fi?
Li-Fi stands for Light Fidelity and is a Visible Light Communications (VLC) system which uses light to send wireless data embedded in its beam. A Li-Fi enabled device converts the beam of light into an electrical signal. The signal is then converted back into data. The term was coined by German physicist Harald Haas during a TED Talk in 2011. He envisioned the idea of using lightbulbs as wireless routers.
LiFi bulbs are outfitted with a chip that modulates the light imperceptibly for optical data transmission. LiFi data is transmitted by the household LED bulbs and received by photoreceptors. If implemented meticulously, Li-Fi systems can reach transmission speeds which are upto 100 times faster (more than 1 Gigabit per second) than the current traditional Wi-Fi which works on radio waves.
Architecture Of Li-Fi System
Li-Fi which can be the future of data communication appears to be a fast and cheap optical version of Wi-Fi. It uses visible light of electromagnetic spectrum between 400 THz and 800 THz as optical carrier for data transmission and illumination.
The main components of a basic Li-Fi system contains the following:
a) A high brightness white LED which acts as transmission source.
b) A silicon photodiode with good response to visible light as the receiving element.
LED light bulbs can be dipped and dimmed, up and down at extremely high speeds, without being visible to the human eye. The tiny changes/pulses in the rapid dimming of LED bulbs is then converted by the ‘receiver’ into electrical signal. The signal is then converted back into a binary data stream that we would recognise as web, video and audio applications that run on internet enabled devices.