Which of the following describes DMR?
A technique for time-multiplexing two digital voice signals on a single 12.5 kHz repeater channel
This is the correct answer because DMR uses TDMA to time-multiplex two digital voice signals on a single 12.5 kHz repeater channel, effectively doubling the channel’s capacity.
An automatic position tracking mode for FM mobiles communicating through repeaters
This is incorrect because automatic position tracking, typically referring to APRS (Automatic Packet Reporting System), is not a characteristic of DMR.
An automatic computer logging technique for hands-off logging when communicating while operating a vehicle
This is incorrect because DMR does not describe a computer logging technique; rather, it is a digital radio standard focused on efficient voice communication.
A digital technique for transmitting on two repeater inputs simultaneously for automatic error correction
This is incorrect because DMR does not transmit on two repeater inputs simultaneously; it uses time-slots within the same channel for error correction and communication.
Explanation
DMR, which stands for Digital Mobile Radio, is a digital two-way radio standard that is designed to provide a cost-effective and spectrum-efficient method of voice communication. One of the key features of DMR is its ability to use Time Division Multiple Access (TDMA) to time-multiplex two digital voice signals on a single 12.5 kHz repeater channel. This means that within the same frequency space, two separate voice conversations can occur simultaneously, effectively doubling the capacity of the communication channel without requiring additional bandwidth. This is particularly important for amateur radio operators and commercial users who often have limited frequency allocations. By improving spectral efficiency, DMR helps in optimizing the use of available bandwidth, which is a crucial resource in radio communications. The ability to handle multiple conversations in one channel also makes DMR a preferred choice in many amateur radio communities and commercial radio services.
T8D07 2022-2026