Question T8D07
From subelement T8 - T8D
Which of the following describes DMR?
Why is this correct?
DMR (Digital Mobile Radio) uses time-multiplexing to put two separate digital voice signals on a single 12.5 kHz repeater channel, effectively doubling capacity without using more spectrum. Option B describes APRS position tracking, option C describes logging software, and option D describes a non-existent error correction method. DMR's time-division approach allows two conversations simultaneously on one frequency.
Memory tip
When you see 'time-multiplexing' with digital voice modes, think DMR. The key pattern is that digital modes often solve spectrum efficiency problems—DMR doubles channel capacity, while System Fusion provides analog/digital compatibility, and D-STAR enables call sign routing through linked repeaters.
Learn more
DMR networks use talkgroups for worldwide communication through internet-linked systems. Your radio requires proper programming with color codes (must match the repeater's code for access) and talkgroup IDs stored in a 'code plug.' This programming complexity enables DMR's advanced features like selective calling and wide-area networking that weren't possible with traditional analog FM repeaters.
Think about it
Why do you think DMR chose time-division multiplexing instead of frequency-division multiplexing to increase channel capacity?