A. Overview of LI-FI Technology
LI-FI stands for “Light Fidelity”. The technology uses an LED light bulb that varies in intensity faster than the human
eye can follow to send data through illumination [3]. The light that zips data across the Internet’s backbone used to stop a
long way from the data’s final destination but now it goes all the way to our homes. The LI-FI technology takes the last
step and takes the light all the way to the computer or TV, projecting it through the air over the last few meters and only
converting it to an electronic signal at the end.
Since LI-FI uses visible light instead of radio waves as the medium of communication, LI-FI is considered as the optical
version of WI-FI. LI-FI is an important component of the Internet of Things (IoT), in which everything is connected to
the internet. LED lights are used as access points in case of IoTs.[5] Such indoor optical wireless probably wouldn’t
replace Wi-Fi, but with a potential for data rates of 3 terabits per second and up, it could certainly find its uses. Wi-Fi, by
contrast, tops out at about 7 Gb/s. And with light, there’s no worry about sticking to a limited set of radio frequencies. If
someone is in the optical window, he will have virtually unlimited bandwidth and unlicensed spectrum.
With the increasing use of Wi-Fi, the existing radio frequency is getting blocked slowly and simultaneously, there is an
increasing number of people who want to connect to the internet. Wireless radio frequencies are getting higher,
complexities are increasing and RF interferences continue to grow [6]. The LI-FI technology helps us to overcome these
problems. LI-FI uses the Visible Light Communication (VLC). Visible light communication is a data communications
medium which uses visible light between 400 and 800 THz (780–375 nm). VLC is a subset of optical wireless
communications technologies. The technology uses fluorescent lamps (ordinary lamps, not special communications
devices) to transmit signals at 10 kbit/s, or LEDs for up to 500 Mbit/s. Low rate data transmissions at 1 and 2 kilometres
(0.6 and 1.2 mi) were demonstrated. Specially designed electronic devices generally containing a photodiode receive
signals from light sources, although in some cases a cell phone camera or a digital camera will be sufficient.