Digital Mobile Radio, or DMR for short, is a digital two-way radio standard offered by ETSI for global use. It is an open standard designed primarily to replace the aging analogue standards with double the channel capacity, providing cost optimised, secure and reliable communications for professional mobile users.
One of the reasons DMR provides such an easy migration path for existing analogue radio users is that it operates within the existing 12.5 kHz channel spacing used in licensed land mobile frequency bands globally. This removes the need for time consuming and expensive frequency re-cycling or special frequencies allocation. Most manufacturers enable mixed fleets of analogue and digital radios to operate together to enable a gradual transition.
The great benefit of DMR is that it provides two voice channels for every one analogue channel through the use of two-slot TDMA (Time Division Multiple Access) technology, which divides a 12.5 kHz channel into two independent time slots. It also means DMR achieves the 6.25 kHz channel equivalence (6.25e), specified by many global regulators seeking greater spectral efficiency.