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What is DMR?

Digital Mobile Radio Association logoDigital Mobile Radio, or DMR, is a digital radio standard specified for business mobile radio users developed by ETSI, European Telecommunications Standards Institute, and first ratified in 2005.

The standard is designed to operate within the existing 12.5kHz channel spacing used in licensed land mobile frequency bands globally and to meet future regulatory requirements for 6.25kHz channel equivalence. The primary goal is to specify affordable digital systems with low complexity. DMR provides voice, data and other supplementary services. Today, products designed to its specifications are sold in all regions of the world by a variety of manufacturers. Digital Mobile Radio (DMR) technology is rapidly becoming the most widely supported digital radio standard for the twenty first century business world.

Digital Mobile Radio (DMR) standards are divided into three tiers.

DMR Tier I (Unlicensed)

DMR Tier I products are for license-free use in the 446MHz band. Tier I provides for consumer applications and low-power commercial applications, using a maximum of 0.5Watt RF power. With a limited number of channels and no use of repeaters, no use of telephone interconnects, and fixed/integrated antennas, Tier I DMR devices are best suited for personal use, recreation, small retail and other settings that do not require wide area coverage or advanced features.

The DMR Association concentrates its effort on the professional use of DMR, thus Tier II and Tier III.

DMR Tier II (Conventional)

Tier II covers licensed conventional radio systems, mobiles and hand portables operating in PMR frequency bands from 66-960MHz. The ETSI DMR Tier II standard is targeted at users who need spectral efficiency, advanced voice features and integrated IP data services in licensed bands for high-power communications. ETSI DMR Tier II specifies two-slot TDMA in 12.5kHz channels.

DMR Tier III (Trunked)

DMR Tier III covers trunking operation in frequency bands 66-960MHz. The Tier III standard specifies two-slot TDMA in 12.5kHz channels. Tier III supports voice and short messaging handling similar to MPT-1327 with built-in 128 character status messaging and short messaging with up to 288 bits of data in a variety of formats. It also supports packet data service in a variety of formats, including support for IPv4 and IPv6.

ETSI Downloads

General System Design TR 102 398 v1.3.1

Part 1: DMR Air Interface (AI) Protocol – TS 102 36-1 v2.4.1

Part 2: DMR Voice and Generic Services – TS 102 361-2 v2.3.1

Part 3: DMR Data Protocol – TS 102 361-3 v1.2.1

Part 4: DMR Trunking Protocol – TS 102-361-4 v1.8.1


MOTOTRBOTM is Motorola’s proprietary trade mark name for its portfolio of products based on Digital Mobile Radio (DMR) Standards. Contact us for more information.