dPMR is a 6.25 kHz FDMA based digital radio protocol described in the ETSI technical standards TS 102 490 and TS 102 658. The TS 102 490 standard defines dPMR 446 license-free radio and the TS 102 658 defines Mode 1 peer-to-peer mode, Mode 2 repeater mode and Mode 3 digital trunking. dPMR is specifically targeting highly functional solutions by using lower cost and less complex technology. Details of the dPMR protocol can be found on the dPMR Association website. (http://www.dpmr-mou.org)
|TS 102 490||Tier 1||-||License-free (dPMR 446)|
|Mode 1||Direct Peer-to-peer Mode|
|TS 102 658||Tier 2||Mode 2||Conventional Repeater Mode|
|Mode 3||Digital Trunking Mode|
Currently, the broad range of products and services including telecommunication, broadcast and information services use digital technology and the PMR (Private Mobile Radio) market is no exception. The move toward digital systems started over a decade ago and this trend is still growing rapidly. The merits of moving from analogue to digital are outlined below.
When compared to an analogue FM signal, digital easily outperforms analogue at the fringes of the communication range, thus providing more intelligible audio over a greater total area, even if the coverage footprint is the same as analogue FM.
dPMR radios incorporate the industry standard DVSI AMBE+2™ vocoder. The vocoder converts the analogue audio signal to a digital signal and reduces unwanted signals such as background noise and acoustic echo to deliver better voice quality and clarity.
Using digital modulation, dPMR radios cannot be easily monitored with an analogue receiver. A 15-bit digital scrambler also adds to the enhanced security of dPMR radios.
The dPMR system allows you to scale migration to a digital system at your own pace and needs, while running your existing system. If the radio users increase in the future, or you require expanded communication coverage, the dPMR conventional system can be upgraded to a multi-site system, or grow into a Mode 3 trunking system while using the same subscribers*. This provides investment protection for your communication system.
* Depending on radio model/firmware revision.
Since the dPMR system uses digital signals, these can be easily converted and transferred to an IP network or IP based applications. This means an increase in communication coverage.