Technology
© iStockphoto.com/Rachel Donahue
DMR gets attention and with good reason Matt Kelly, group managing director, Combined Communications and Wireless Data Solutions
Previous articles in Radio Comms Asia-Pacific have presented varying views on DMR technology and may have led some readers to believe that DMR is another digital radio ‘flash in the pan’ that has no place in an already busy Australian digital radio landscape.
M
y own view is that nothing could be further from the truth and that with the current availability in Australia of ETSI open standard DMR products that range from Tier III wide area trunking systems to conventional IP connected, there has never been a better time of real choice for digital radio purchasers. Unlike the manufacturers of the vast majority of other digital offerings, there are large and well-funded manufacturers who are not afraid to produce an open standard digital radio product. Radio system planners, consultants, network vendors and end users now have the ability to implement digital radio that allows seamless operation of other manufacturers’ equipment and to benefit from market competition. A significant number of radio manufacturers, who are well known and who operate in the Australian market, have joined the DMR Association and have signalled their intention to produce ETSI-compliant DMR terminal, infrastructure and applications. Today the DMR MOU boasts 16 Category1 members, five Category2 members and seven Category3 members and two Partners, and while there had been only one manufacturer pushing the technology, more than a million DMR terminals were sold from October 2007 to June 2011. www.radiocomms.com.au
“DMR manufacturers are already producing quad mode MPT1327 and DMR terminals and infrastructure that will support network vendors and their MPT users.”
DMR products available in Australia today already interoperate with each other on a voice communications level and as other manufacturers arrive in the market later this year and early next year, market competition will see the already significantly well priced and spectrally efficient DMR terminals provide even greater choice for DMR radios. The example that MPT1327 systems have provided in Australia is that by deploying open standards systems and compliant terminals, users get real choice and DMR trunking will provide the same rich feature set of MPT but with an extensive range of capabilities that only digital radios can deliver. DMR manufacturers are already producing quad mode MPT1327 and DMR terminals and infrastructure that will support network vendors and their MPT users. On a technical level, DMR and dPMR are both low-cost digital standards, one being FDMA which occupies a true
6.25 kHz channel spacing in the available frequency spectrum. DMR is a twoslots TDMA technology that alternates between slots to mimic the 6.25 kHz, which is often referred to as equivalent 6.25 kHz. Unlike TETRA digital standard, both these low-cost technologies are backward compatible to analog product, which simplifies analog to digital migrations. This effectively means that the users considering an upgrade to digital have the added advantage of re-using much of in-place towers and antenna systems as they have the same coverage as existing analog radio if the radiated power is kept the same. As conventional users migrate to a new system on the back of ACMA changes, additional DMR features such as native IP connectivity available on DMR base stations and all the terminal bells and whistles that many users will require will, in my opinion, propel those users looking for a digital solution towards the cost-effective system of choice. In the past the only digital option for two-way radio users has been the very cost-prohibitive APCO P25 and TETRA trunking systems. With the release of the DMR Tier III trunking, it has been proved that DMR Tier III is good enough to replace the aging analog trunking systems such as the MPT1327, SmartNet, SmartTrunk, LTR and Privacy Plus.
September/October 2011 - RADIO COMMS
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