Currently, a broad range of products and services including telecommunication, broadcast and information services use digital technology and there is no exception for PMR (Private Mobile Radio) market. The move toward digital systems started a decade ago, the trend is still growing rapidly. The merits of moving from analogue to digital are outlined as below.
Wider Communication Coverage
When compared with 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 voice of better quality and clarity.
Adopting the digital modulation, DPMR radios cannot be easily monitored by an analogue receiver. The security of DPMR is also enhanced with a digital scrambler added.
Flexible Migration And Upgrade Path
The DPMR system allows scale migration from an existing system to a digital system at your own pace and needs. Should there be more radio users and the communication coverage needs expansion in the future, 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.
IP Network Connectivity
The DPMR system uses digital signals that can be easily converted and transferred to an IP network or IP based applications, meaning an increase in communication coverage.
6.25kHz Narrowband FDMA Technology
DPMR radios only use 6.25 kHz per channel. In general, the narrower the channel is, the better the sensitivity will become, and the wider the communication ranges will be obtained. Where installation conditions allow, FDMA systems can deploy two repeater sites using two 6.25 kHz channels to increase the communication coverage in total, but still only using 6.25 kHz spectrum. The spectrum efficiency of FDMA is maintained in direct peer-to-peer communication at 6.25 kHz, where competing TDMA systems require infrastructure to achieve the same efficiency.
Selective Call And Group Call
DPMR radios allow you to call individuals or group users. The way of call set-up is similar to the analogue system, thus analogue users can introduce DPMR without hesitation and avoid a new learning curve.
DPMR radios provide status call, short data messages and GPS position data with voice communication. When DPMR radios are connected to a PC or other external equipment, the DPMR transparent data mode provides data communication in a 6.25 kHz channel.
Communication Link For Distant Locations
DPMR IP network can extend your communication coverage, allowing you to communicate like a single site and enabling you to connect dispersed sites or different bands over the IP network. In a building all the way from the basement to the top floor, radio communication can be covered using already deployed LAN cables.
DPMR Repeater Connection
With the optional repeaters can be interlinked with each other. radio user can communicate with other terminal radio users using the interlinked repeater sites on the network. Conventional IP network cannot relay voice traffic over the IP network if the uplink is analogue.
Integrated System For Clean And Simple Installation
DPMR IP network requires only the network controller which can be installed into the series repeater – no control server or no extra rack space is required. In addition, the repeater and network controller settings can be maintained and monitored remotely over an IP connected PC.