Li-Fi (Light Fidelity) is a high-speed wireless communication technology that uses visible light to transmit information. Wi-Fi and Li-Fi are similar because both technologies are wireless, but also very different, because unlike Wi-Fi, which relies on radio waves, Li-Fi uses visible light communication (VLC) or infrared and near-UV spectrum waves.

Working of Li-Fi

1. Li-Fi is a Visible Light Communications (VLC) system. This means that it accommodates a photo-detector to receive light signals and a signal processing element to convert the data into streamable content. Here, data is fed into an LED light bulb (with signal processing technology), it then sends data (embedded in its beam) at rapid speeds to the photo-detector (photodiode).

2. The tiny changes 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 the user would recognise as web, video and audio applications that run on internet enables devices.

Potential applications

1. RF Spectrum Relief: Excess capacity demands of cellular networks can be off-loaded to Li-Fi networks where available. This is especially effective on the downlink where bottlenecks tend to occur.

2. Smart Lighting: Any private or public lighting including street lamps can be used to provide Li-Fi hotspots and the same communications and sensor infrastructure can be used to monitor and control lighting and data.

3. Mobile Connectivity: Laptops, smart phones, tablets and other mobile devices can interconnect directly using Li-Fi. Short range links give very high data rates and also provides security.

4. Hazardous Environments: Li-Fi provides a safe alternative to electromagnetic interference from radio frequency communications in environments such as mines and petrochemical plants.

5. Hospital & Healthcare: Li-Fi emits no electromagnetic interference and so does not interfere with medical instruments, nor is it interfered with by MRI scanners.