1 Control & System Engineering Dept, University of Technology, Baghdad, Iraq.

2 Control & System engineering department, University of Technology, Baghdad, Iraq.


Wireless Fidelity (Wi-Fi) is particularly popular today. Every place has
hotspots to access the internet via Wi-Fi, including homes, offices, colleges, and other
public places. This increased number of users, and hence the use of bandwidth, has led to
radio spectrum congestion. Thus, in the year of 2011, Light-Fidelity (Li-Fi) was
introduced, which applies a visible light region for data transmission, to solve this radio
crisis problem. This visible part of the spectrum was 10,000 times big compared to the
part utilized in the Wi-Fi radio. Furthermore, Li-Fi was a sub-set of Visible Light
Communication (VLC), using Light-Emitting Diode (LED) bulbs for transmitting data
utilizing light-medium. This paper reviews the differences between Li-Fi technology and
wireless types. It Also focuses on the architecture, components, functioning, modulation
technologies, and applications of Li-Fi.