Li-Fi is an innovative wireless communication technology which utilizes LED light to transmit data and position between devices. It offers high bandwidth, immunity to interference from electromagnetic sources, and high levels of communications security.
Optical Wireless Communication
In the last few years, the interest towards Optical Wireless Communication (OWC) has increased for terrestrial space and underwater links as it is capable of providing high data rates with low power and mass requirement.
Generally, when we speak about OWC, it includes Visible Light (VL), Infrared (IR), Laser and Ultraviolet (UV).
Visible Light Communication
Visible Light Communication (VLC), is an innovative wireless communication technology offering high bandwidth, immunity to interference from electromagnetic sources, and high levels of communications security. In addition, the latest advances in the field of solid state lighting, and the inevitable replacement of florescent lighting by Light Emitting Diodes (LEDs), facilitates the deployment of VLC technology. The combination of bidirectional VLC with LEDs, is referred to as Li-Fi.
Infrared Wireless Communication
IR light is very similar to Visible Light (VL), except that it has a slightly longer wavelength. This means IR is undetectable to the human eye and perfect for wireless communication.
Li-Fi
Li-Fi or Light Fidelity, as part of OWC, uses VL and IR to achieve high speed, secure, bi-directional, EMI free and fully networked wireless communications. It is important to note that Li-Fi supports user mobility, access point hand off and multiuser access.
Li-Fi addresses the shortcomings of current localized wireless communications and is a reliable complementary solution to the existing Radio Frequency (RF) communication. The RF communication suffers from interference, limited bandwidth, and security issues. In addition, RF communication requires a separate setup for transmission and reception of RF waves, at the cost of higher energy consumption. Finally, the limited RF spectrum is unable of meeting the demand for ubiquitous low energy and high capacity connectivity, which is necessary for an efficient implementation of the Internet/Industrial Internet of Things (IoT/IIoT).
Li-Fi resolves the low bandwidth problem of RF by employing the entire range of the VL and IR spectrum, which is 2600 times larger than existing RF spectrum. Additionally, VL and IR spectrum, unlike RF spectrum, are not being used, and are available and license free.
Since Li-Fi receivers need to reside in the same room as the transmitter, any receivers outside that room will not be able to intercept the signal. This eliminates the inherent security issues of RF communication systems such as Wi-Fi and Cellular.
From energy consumption perspective, Li-Fi is based on LED lighting, which not only has low energy consumption, but can also be used for illumination. Compared to Wi-Fi, this will eliminate the need for the extra power needed for the access points.