Digital private mobile radio

dPMR or digital private mobile radio, is a Common Air Interface (CAI) for digital mobile communications. dPMR is an open, non-proprietary standard that was developed by the European Telecommunications Standards Institute (ETSI) and published under the reference ETSI TS 102 658.

A simplified version of the dPMR protocol intended for licence-free applications was also published by ETSI under the reference TS 102 490.

dPMR is very similar to NXDN protocol implementation by Kenwood and Icom; both now offer dual-standard equipment (July 2013).

What is significant is that dPMR achieves all this in a 6.25 kHz channel.

Because the emission mask is so tight, two 6.25 kHz dPMR signals can be used next to each other within a 12.5 kHz channel without causing interference to each other or adjacent channels. Compliance with EN301 166 at 6.25 kHz for current equipment is one measure of guarantee that interference issues are no different from at 12.5 kHz or 25 kHz. Frequency co-coordinators in the USA have even made recommendations to the FCC about setting up new 6.25 kHz systems adjacent to existing systems, outlining parameters to avoid harmful interference.

dPMR equipment complies with the relevant European standard ETSI EN 301 166 as well as the FCC emission mask applicable for operation in the US.

dPMR446 radios are licence-free products for use in the 446.1–446.2 MHz band within Europe.

These are fully digital versions of PMR446 radios.

dPMR446 radios comply with the ETSI TS 102 490 open standard and are limited to 500 mW RF power with fixed antennas per ECC Decision (05)12. They are ideally suited to recreational and professional users who do not need wide area coverage with base stations and repeaters.

dPMR446 equipment is capable of voice, data and voice+data modes of operation.

This means that dPMR446 can provide voice calls, text messaging (SMS), status and embedded data such as GPS position etc.

This is the peer to peer mode of dPMR (without repeaters or infrastructure) but without the limitations of the licence-free counterpart. It can operate all typical licensed PMR frequency bands and without the RF power limits of dPMR446. As well as offering voice and data, dPMR446 Mode 1 also supports combined voice+data so it is possible to embed data into a voice call or automatically append it at the end of a call.

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