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 ?
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3 ✓ UPSC's answer
Why the answer is (d)
• Short-Range Devices (SRDs) are low-power radio devices operating over short distances in licence-exempt bands, as defined by the ITU and telecom regulators.
• Wireless CCTV systems transmitting video over a few hundred metres are classed as SRDs (item 1).
• RFID tags and readers, used in access cards, tolls and inventory, communicate over centimetres to metres (item 2).
• Wireless LAN (Wi-Fi) operates in the 2.4 and 5 GHz licence-exempt bands over tens of metres (item 3).
• Hence all three, option (d).
Why the other options are wrong
- (a) 1 and 2 only
- Wireless LAN is also a short-range technology.
- (b) 2 and 3 only
- Wireless CCTV is also classed as a short-range device.
- (c) 1 and 3 only
- RFID is also a short-range technology.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2022, held on 5 June 2022. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.