Q. With reference to 'LiFi', recently in the news, which of the following statements is/are correct?
- It uses light as the medium for highspeed data transmission.
- It is a wireless technology and is several times faster than 'WiFi'.
Select the correct answer using the code given below. (UPSC Prelims 2016)
Answer:
Both 1 and 2
Notes: The correct answer is
[C] Both 1 and 2.
LiFi (Light Fidelity) is a wireless communication technology that uses light to transmit data instead of the radio waves used by WiFi.
- Statement 1 (Correct): LiFi is a Visible Light Communication (VLC) system. It uses Light Emitting Diodes (LEDs) to emit pulses of light that are imperceptible to the human eye. These pulses carry digital data to a receiver (photodiode), which converts the light back into an electrical signal.
- Statement 2 (Correct): LiFi is a wireless technology and is significantly faster than traditional WiFi. While WiFi speeds typically range from 100 Mbps to 10 Gbps (depending on the standard), LiFi has demonstrated speeds in excess of 100 Gbps in laboratory settings—potentially making it 10 to 100 times faster than WiFi.
Comparison between LiFi and WiFi:| Feature | LiFi | WiFi |
| Medium | Visible Light / Infrared | Radio Waves |
| Speed | Very High (up to 100 Gbps+) | High (up to 10 Gbps) |
| Range | Limited (cannot pass through walls) | Wide (can pass through walls) |
| Security | High (confined to the room) | Moderate (signals can be intercepted) |
| Interference | Minimal (no EM interference) | Common (affected by other devices) |
Key Advantages:- Security: Since light cannot penetrate opaque walls, the data signal is physically contained within a room, making it much harder to "hack" from the outside.
- Electromagnetic Safety: It is ideal for sensitive environments like aircraft cabins, hospitals, or nuclear power plants where radio waves might interfere with equipment.