Digital mobile radio (DMR) is an open digital mobile radio standard defined in the European Telecommunications Standards Institute (ETSI) Standard TS 102 361 parts 1–4[1]and used in commercial products around the world. DMR, along with P25 phase II and NXDN are the main competitor technologies in achieving 6.25 kHz equivalent bandwidth using the proprietary AMBE+2 vocoder. DMR and P25 II both use two-slot TDMA in a 12.5 kHz channel, while NXDN uses discreet 6.25 kHz channels using frequency division.

DMR was designed with three tiers. DMR tiers I and II (conventional) were first published in 2005, and DMR III (trunked) was published in 2012, with manufacturers producing products within a few years of each publication.

Specifications

The DMR interface is defined by the following ETSI standards:

• TS 102 361-1: Air interface protocol
• TS 102 361-2: Voice and generis services and facilities
• TS 102 361-3: Data protocol
• TS 102 361-4: Trunking protocol