It has taken over a decade for 15 per cent of the world’s licensed mobile radio users to switch from analogue to digital.*
However, despite this sluggish start, recent developments within the industry could possibly see migration more than double in the next five years.
Digital technologies were first introduced to the mobile radio market in the mid-1990s. Early standards included Tetra and APCO Project 25 (P25), and were primarily designed for use by emergency services and public safety groups.
What is DMR?
DMR is a two-slot, time division multiple access (TDMA) system offering voice, data and a range of other features and applications.
This is the same underlying technology used by Tetra and P25 Phase II. Simply put, TDMA divides up spectrum using time slots; user A gets a few milliseconds of access to the bandwidth, and then it is User B’s turn.
DMR Tier 1 is targeted at the unlicensed market, providing for consumer applications and low-power commercial applications.
DMR Tier 2 is targeted at those who require spectral efficiency, advanced voice features and integrated IP data in licensed bands for high-power communications.
DMR Tier 3 is the trunked variant of the standard, for systems with a large number of subscribers and for multi-site networks.
The standard’s primary goal is to specify a digital system offering low complexity, low cost and interoperability across manufacturers. What this means is that user organizations are not locked in to a proprietary solution.
DMR is moving quickly!
The number of interoperability test sessions carried out are increasing, therefore the DMR Association has developed a common application interface specification for digital mobile radio infrastructure to further enhance interoperability – the Application Interface Specification.
The digital mobile radio (DMR) uptake in the current market is very much driven by the application and data support that it provides.
While the DMR standard does specify various means of data transport over the air interface, it currently does not include an interface standard between the DMR network and application devices.
An important aspect of open standards is interoperability as it provides choice as well as comfort. By selecting a digital mobile radio system, customers will not be tied into a single vendor solution.
The DMR Association was pleased to see that not only the number of interoperability test sessions (IOP) carried out were increasing but the test cases covered by IOP were expanding.
To further enhance interoperability, the technical working group of the association has embarked on a complex task – to agree on a common application interface specification for DMR infrastructure.
This interface, called the Application Interface Specification (AIS), will provide connectivity for well-known radio network peripherals such as dispatch consoles and voice recorders, and it will also support data applications like location services tools, workforce management applications and telemetry systems.
The association is committed to this enhancement because it will lead to lower research and development costs for CAD and console manufacturers, who will not be forced to develop specific interfaces for different digital networks.
A further benefit will be faster time-to-market for value-added applications.
2012 is proving to be an important year for the association and the DMR standard. In the course of the year, numerous DMR products have already been launched and it is expected that more will be released over the next few months.
The releases include the offering of the long-awaited DMR Tier III (trunked DMR) products.
The AIS interface is an infrastructure interface for applications.
When the initial draft of that work is completed, a mobile station interface will be defined as well.
The completion of these tasks will be a significant step towards bringing digital mobile radio technology forward and provide long-term benefits to the users of DMR.
* (IMS Research)
For more information on DMR Contact AA RadioJune 26, 2012 5:34 am
This post was written by aa radio