With reference to 'LiFi', recently in the news, which of the following statements is/are correct?
- 1.It uses light as the medium for high-speed data transmission.
- 2.It is a wireless technology and is several times faster than 'WiFi'.
Select the correct answer using the code given below.
Answer & explanation
Answer: (c) Both 1 and 2
Li-Fi (Light Fidelity) is a form of visible light communication: an LED is switched on and off far faster than the eye can notice, and those flickers carry data through the air to a photodetector. It is wireless like Wi-Fi, but uses the visible-light band instead of radio waves and has reached speeds several times higher.
- ✓ 1. Li-Fi sends data by modulating visible light from LEDs rather than by radio waves; the Telecommunication Engineering Centre describes it as data transfer through LED light.
- ✓ 2. No cable is involved, so it is wireless. TEC's comparison puts Li-Fi at about 1 Gbps against about 150 Mbps for Wi-Fi (IEEE 802.11n), several times faster, though over a short range of under 10 metres.
Remember · Li-Fi = wireless data over visible light from LEDs (IEEE 802.15.7); faster and more secure than Wi-Fi, but short-range and blocked by walls.
Sources
- Telecommunication Engineering Centre (DoT): Study Paper on LiFi (Light Fidelity) & its Applications ↗ “Li-Fi provides better bandwidth, efficiency, connectivity and security than Wi-Fi and has already achieved high speeds larger than 1 Gbps under the laboratory conditions.”
- PIB, Ministry of Electronics and IT: C-DAC Chennai transfers Li-Fi technologies (28 November 2024) ↗ “Visible Light Communication (VLC)/Light Fidelity (Li-Fi) uses light waves instead of traditional radio waves to transmit data, offering unprecedented advantages such as faster speeds, enhanced security, and greater energy efficiency.”
Question and answer: UPSC's official GS Paper I (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·