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 ?

The correct option is 1, 2 and 3 (represented in the options list as "1, 2 and").

To understand why all three are classified as Short-Range devices/technologies, let's break down each technology and its typical range of operation:

1. Closed-circuit Television (CCTV):
CCTV systems are designed for localized surveillance. The signals are not publicly broadcast but are transmitted directly to a limited set of monitors within a specific, restricted area (such as a building, campus, or store). The transmission medium—whether coaxial cables, fiber optics, or localized wireless links—operates over a short distance, making it a short-range communication setup.

2. Radio Frequency Identification (RFID):
RFID technology is explicitly designed for short-range communication. Passive RFID tags usually have a read range of a few centimeters to a few meters (typically up to 10 meters). Active RFID tags, which have their own power source, can extend this range up to about 100 meters. Regardless of the active or passive nature, RFID operates strictly within a localized, short range to identify and track tags attached to objects.

3. Wireless Local Area Network (WLAN / Wi-Fi):
WLAN technologies, commonly known as Wi-Fi, provide wireless network coverage over a localized area. The typical range of a standard WLAN access point is approximately 20 to 100 meters indoors, and slightly more outdoors. It is designed to connect devices within a home, office, or single building, which places it firmly in the category of short-range wireless communication technologies compared to long-range technologies like cellular networks (LTE/5G) or satellite communications.

Since all three technologies—Closed-circuit Television, Radio Frequency Identification, and Wireless Local Area Network—are restricted to localized, short-distance communications, all three are considered Short-Range devices/technologies.