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.
IDAS dPMR radios only use 6.25kHz per channel. In general, the narrower the channel, the better the sensitivity becomes, and longer communication ranges can be obtained. Where installation conditions allow, FDMA systems can deploy two repeater sites using two 6.25kHz channels to increase the communication coverage in total, but still only using 6.25kHz spectrum. The spectrum efficiency of FDMA is maintained in direct peer-to-peer communication at 6.25kHz, where competing TDMA systems require infrastructure to achieve the same efficiency.
IDAS dPMR radios allow you to call individual or group users. The way of call set-up is similar to the analogue BIIS 1200 system. Analogue users can introduce IDAS dPMR without hesitation and avoid a new learning curve with these radios.
IDAS dPMR radios provide status call, short data messages and GPS position data with voice communication. When IDAS dPMR radios are connected to a PC or other external equipment, the IDAS dPMR transparent data mode provides up to 3,600 bps data communication in a 6.25kHz channel.
An IDAS dPMR IP network can extend your communication coverage and allows you to communicate like a single site. It lets you 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.
With the optional UC-FR5000 (#12), up to 16 IDAS repeaters can be interlinked with each other. An IDAS terminal radio user can communicate with other IDAS terminal radio users using the interlinked repeater sites on the network. * The IDAS conventional IP network cannot relay voice traffic over the IP network if the uplink is analogue.
The IDAS dPMR IP network requires only the UC-FR5000 (#12) network controller which can be installed into the IC-FR5100 series repeater – no control server and no extra rack space is required. In addition, the repeater and network controller settings can be remotely maintained and monitored over an IP connected PC.
By using the AMBE+2™ vocoder compression, an IDAS dPMR IP network requires only about 13kbps bandwidth per one voice path in theory. It means a DSL class line is sufficient for the IDAS dPMR IP network in terms of the Internet connection speed. A fixed IP address is required for each networked repeater.