Q. Consider the following communication technologies:
1. Closed-circuit Television
2. Radio Frequency Identification
3. Wireless Local Area Network
Which of the above are considered communication Short-Range devices/technologies?
a) 1 and 2 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3
Correct Answer: d) 1, 2 and 3
Question from UPSC Prelims 2022 GS Paper
Explanation :
All three technologies mentioned can be considered short-range communication devices/technologies.
Here’s why each one is considered short-range:
1. Closed-circuit Television (CCTV):
CCTV systems use cameras that transmit video signals to a specific, limited set of monitors. The transmission is not broadcast over the air like traditional television but is instead confined to a private network (closed-circuit). The range of CCTV is limited by the design of the system and the type of cabling used. It is typically used for surveillance within a specific area like a building, campus, or commercial complex, which makes it a short-range communication technology in the context of its operational environment.
2. Radio Frequency Identification (RFID):
RFID systems consist of tags and readers. An RFID tag contains a chip and antenna, and it transmits data to an RFID reader through radio waves. The range of RFID systems can vary from a few centimeters to several meters, depending on the type of RFID (low-frequency, high-frequency, or ultra-high-frequency) and the power of the reader. Even though some RFID systems can reach up to a few meters, they are still considered short-range compared to other communication technologies like cellular networks.
3. Wireless Local Area Network (WLAN):
WLAN, commonly known as Wi-Fi, is a wireless network technology that allows devices to connect to the internet or communicate with one another within a local area. The typical range of a WLAN is limited to a few tens of meters indoors, although it can be extended with the use of additional access points or signal boosters. Despite the possibility of extending its range, WLAN is still considered a short-range communication technology because it is designed to operate within a limited geographical area, such as a home, office, or campus.
Therefore, the correct answer is “1, 2 and 3” because all these technologies are designed to operate over short distances within a specific and confined area.
