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SciTech0170 – LiFi: Sending Data Through Light, Not Radio Waves

WiFi sends data through radio waves. One newer technology sends it through the flicker of an ordinary LED bulb instead.

An LED filament bulb, the kind of light source LiFi uses to transmit data. Photo by Sergio Boscaino, via Wikimedia Commons. Licensed CC BY 2.0.

📑 Contents

🏛️ Must Know

Both Claims About LiFi Check Out

Uses Light for Data Transmission LiFi genuinely uses light as the medium for high-speed data transmission.
Faster Than WiFi LiFi is a wireless technology and can be several times faster than WiFi.
Both Statements Are Correct Neither claim about LiFi is false; both hold up under scrutiny.

📘 Good to Know

How LiFi Actually Sends Data Through Light

Modulating LED Intensity LiFi transmits data by rapidly modulating the intensity of an LED light. These changes happen too fast for the human eye to notice.
Up to 100 Gbps LiFi can transmit data at speeds up to 100 Gbps, dramatically faster than typical WiFi speeds.
Visible, Infrared, or UV Light LiFi can use visible light, infrared, or near-ultraviolet light as its transmission medium, unlike WiFi’s radio waves.

📝 Previous Year Questions

UPSC CSP 2016 — What LiFi Actually Is

UPSC 2016 LiFi genuinely uses light for high-speed data transmission and is a wireless technology several times faster than WiFi. Both statements are correct. See UPSC CSP 2016 GS Paper I, Q5. View this question.

🌟 Great to Know

Where LiFi Could Actually Matter

Works Where Radio Waves Can’t LiFi can operate in radio-sensitive environments like hospitals and aircraft cabins. WiFi signals may cause interference in these same places.
Confined by Line of Sight LiFi generally requires a direct line of sight to the light source, unlike WiFi, which can pass through walls.
Connects to Other PYQ Facts This same light-versus-radio-wave distinction also underlies UPSC questions on other emerging wireless communication technologies.