Consider the following communication technologies :
- 1.Closed-circuit Television
- 2.Radio Frequency Identification
- 3.Wireless Local Area Network
Which of the above are considered Short-Range devices/technologies ?
Show answer
Answer: D. Short-range devices are low-power communication systems that work over a small area, so they rarely interfere with other radio services. RFID works over centimetres to a few metres, Wireless LAN (Wi-Fi) over tens of metres, and CCTV is a closed network inside a building or campus, often linked by short-range wireless. So 1, 2 and 3.
Watch for: Students think of CCTV as a wired security system, not a communication technology, but it works over a closed, short-range network.
Why the other options are wrong
- A. Wrong because WLAN (Wi-Fi) is also a short-range technology.
- B. Wrong because CCTV also works only within a limited area.
- C. Wrong because RFID is also a short-range technology.
Source to check: ITU-R Recommendation SM.1896 and ETSI/CEPT ERC Recommendation 70-03 on Short Range Devices; Department of Telecommunications licence-exempt band notifications
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.