dPMR, the digital personal, private or professional mobile radio system is a new digital PMR system that has been developed to meet the needs of many radio users.
The dPMR or digital PMR system has been developed to offer improved performance over systems such as the licence free analogue PMR446, as well as providing more advanced capabilities for more demanding professional mobile radio users.
In order to support the development of dPMR, digital PMR and to provide a forum for all interested dPMR parties, the dPMR MoU group was established in 2007. The dPMR MoU group includes radio manufacturers, chip manufacturers, protocol and software developers and systems developers. By working together to develop, define and promote dPMR, the technology will gain market share and become more widely deployed.
One of the main requirements for any technology such as dPMR where equipment will be available from many suppliers is that it should be completely interoperable.
The dPMR MoU group has been particularly active in this area ensuring an independent validation of interworking between dPMR products from different manufacturers and identifying equipment tested under dPMR MoU auspices by the use of a specific dPMR logo.
The dPMR, digital PMR system is a standard that has been defined by ETSI - European Telecommunications Standards Institute.
The dPMR standard defines an FDMA, frequency division multiple access scheme using narrowband 6.25 kHz channels and 4FSK modulation to provide efficient spectrum usage and low costs.
The dPMR system is aimed at a number of personal, private, and professional mobile radio user groups:
Consumer (and short-range industrial)
Public Safety/Mission-Critical applications
The dPMR, digital PMR system is able to operate on many frequencies dependent upon the national frequency planning and licensing regulations. However the digital PMR system has also been developed to operate within the unlicensed areas available between 446.1 and 446.2 MHz.
The digital PMR system has been developed in tiers according to the intended applications and system complexity required:
- This dPMR tier is aimed at the low cost license exempt market that could be considered as the digital PMR446 arena, and as a result it is often referred to as dPMR446. The Tier 1 dPMR is the simplest form of the technology and allows peer-to-peer operation only without the use of repeaters or base stations.
- The dPMR tier is aimed at the professional market and offers three modes of operations:
Mode 1: This is a peer to peer mode for the professional dPMR variant.
Mode 2: dPMR mode 2 adds a considerable level of functionality over Mode 1. Repeaters and infrastructure are added, allowing networks interfaces which can either be IP based or analogue.
Mode 3: This dPMR, digital PMR mode offers trunked, managed access operation. It provides the capability to enable multichannel, multisite radio networks that are fully managed by specific beacon channels at each radio site. The management of the radio networks includes authentication of radios that wish to connect to the network.
dPMR, digital PMR aims to fill a hole in the low cost PMR marketplace. Aiming to provide low cost communications systems from the personal mobile radio market through to the more sophisticated repeater based and trunked systems. While the narrowband communications results in rather digital sounding voice, this is perfectly acceptable for most communications applications.
For more information on dPMR Contact AA Radio