With reference to Visible Light Communication (VLC) technology, which of the following statements are correct?
1. VLC uses electromagnetic spectrum wavelengths 375 to 780 nm.
2. VLC is known as long-range optical wireless communication.
3. VLC can transmit large amounts of data faster than Bluetooth.
4. VLC has no electromagnetic interference.
Select the correct answer using the code given below:
Explanation
Statement 1 is correct: Visible Light Communication utilizes optical radiation spanning the human visible spectrum, operating within wavelengths approximately between 375 nm and 780 nm (frequencies roughly 400 to 800 THz).
Statement 2 is incorrect: VLC is strictly a short-range wireless optical communication medium (such as Li-Fi). Because light waves cannot penetrate solid opaque walls and suffer attenuation from ambient light or physical obstructions, its effective transmission distance is limited to indoor rooms or line-of-sight spaces.
Statement 3 is correct: By rapidly pulsing LED light fixtures at gigahertz frequencies, VLC systems can achieve high bandwidths exceeding several gigabits per second, far outstripping conventional Bluetooth data transfer speeds.
Statement 4 is correct: Because it utilizes photons in the optical band rather than radiofrequency waves, VLC produces zero electromagnetic interference (EMI), making it safe for use in aircraft cabins, chemical plants, and surgical environments.
Hence, statements 1, 3, and 4 are correct — Option C.