Question
Q19. 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:
a. 1, 2 and 3 only
b. 1,2 and 4 only
c. 1, 3 and 4 only
d. 2, 3 and 4 only
Answer: c
Detailed Explanation
The Radio Frequency (RF) communication suffers from interference and high latency issues.
· Along with this, RF communication requires a separate setup for transmission and reception of RF waves.
· Overcoming the above limitations, Visible Light Communication (VLC) is a preferred communication technique because of its high bandwidth and immunity to interference from electromagnetic sources.
· The revolution in the field of solid state lighting leads to the replacement of florescent lamps by Light Emitting Diodes (LEDs) which further motivates the usage of VLC
· The signals in the 380 -780 nm wavelength interval of the electromagnetic spectrum are the light signals that can be detected by the human eye. It is possible to achieve illumination and data transfer simultaneously by means of LEDs that is the prominent lighting equipment lately. By this way, both interior lighting of a room and data transfer will be achieved without the need of an additional communication system.
· The light can transmit information either directly or reflected from a surface. It can do so while dimmed. However, light cannot penetrate obstacles such as walls Thus for wireless communication purposes VLC cannot be used for long –distances.
· Bluetooth transmits data at the rate of 300kbps (kilobytes per second), VLC can transmit data in the range between mbps -gbps (megabytes per second to gigabytes per second).
