Ensuring a smooth transition to digital
Local wireless communication specialist Multisource has heralded in a new era of two-way radio communications, with the introduction of digital private mobile radio (dPMR) Mode 3 to South Africa.
Multisource’s launch of dPMR Mode 3 took place at St George Hotel in Rietvleidam, Gauteng recently, where users of two-way radio systems, including members of the military, were given an overview of how dPMR Mode 3 works, the advantages of the new standard over existing standards and the improved and increased functionality of products that operate on the dPMR standard.
The dPMR standard covers 3 modes, Mode 1: peer to peer, Mode 2: via centralized repeaters and Mode 3: via managed repeaters (trunking).
The emphasis with dPMR is on a fully functional radio system that can seamlessly integrate with IP networks, and is capable of offering customisable application software tailored to any business communication needs.
“When combined with a true low-cost approach that is the core of the dPMR protocol, the overall result is the optimum solution for users and network operators alike,” said Richard Smuts-Steyn, CEO of Multisource.
dPMR – Interoperability is key
There is a great need among South African government institutions for communication platforms that can be integrated.
“For users of two-way radio, planning a future migration path to new technology platforms can be bewildering. Interoperability, as well as the integration of analogue and digital, are required, and the choice of radio standard is a difficult one,” Smuts-Steyn said.
“Many state institutions collaborate at different times – for example on border patrols, and it is vital that whatever platform is chosen in the future, can be integrated with existing infrastructure and offer interoperability. Each radio system needs to be able to talk to the other – dPMR offers this advantage,” he said.
The global trend for digital migration is based on the simple fundamental requirement for more channels. The radio spectrum is a limited resource and demand for channels exceeds supply, resulting in interference and an insufficient number of channels, especially in big cities.
Since the beginning of PMR radio, there has been a constant juggling act between available spectrum and channel size. As filter and modulation technology has advanced the channel size has progressively reduced from 100kHz to 50, then 25, then to the current size of 12.5kHz we have known for the past 20 or so years.
“In light of the current policy of spectrum pricing, it became clear that a new advance was needed to make the most efficient and economical use of this scarce resource,” Smuts-Steyn said.
Up to now 6.25kHz was not possible with analogue technology, but research by world-renowned Japanese wireless communications manufacturer ICOM, together with Kenwood and the UK-based Fylde Micro, has proven that 6.25kHz could be achieved using a new digital protocol. These corporations then undertook to develop this technology.
National and International coverage available
dPMR Mode 3 solutions offer wide area multisite, multichannel trunkedbrepeaters capable of national and international coverage if required. dPMR radio equipment can also be easily integrated into existing IT networks with both text messaging and voice calls using the voice and data functionality of dPMR. Solutions already exist for PC based remote control of dPMR base stations to give completely configurable dispatcher functionality.
dPMR Mode 3 also offers users the possibility to operate efficiently in ‘direct mode’ separately from the network or beyond the coverage area of the network for special purposes such as on-scene activities.
“We want the market to understand that ICOM dPMR Mode 3 is real and available right here, right now. It is not vapourware or something planned for the future. South African users can purchase it from Multisource immediately,” Smuts-Steyn said.
Why change? Analysing standards
One of the oldest trunking radio standards is Tetra, which provides four timeslots in a 25kHz channel. However, the coverage penetration of Tetra is poor compared to 12.5kHz analogue FM and dPMR and this standard requires a specially allocated spectrum to avoid interference.
Tetra has traditionally found favour in government and private systems where wide-area coverage is not required but performance, particularly under duress, has been disappointing and costs have escalated.
APCO-25 or P25 (phase 1) equipment is outperformed by dPMR, which has a better signal Bit Error Rate performance than P25 phase one. dPMR technology also offers improved audio quality compared to P25 audio. Using the AMBE+2™ vocoder makes this possible.
DMR is to some extent is vying with dPMR to become the digital radio standard of the moment. There are, however, a number of advantages dPMR has over DMR. dPMR uses one repeater per channel, while DMR uses two. Therefore, in the event of repeater failure, both channels are lost. On the other hand in the case of interference on a dPMR channel, only one channel is affected. dPMR also allows for the deployment of an odd number of channels, meaning no timeslots are wasted. Technical difficulties are experienced when using DMR in terms of the near-far effect. Importantly, dPMR radio equipment is also cheaper to manufacture than DMR equipment.
dPMR offers scaled migration
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, hosting up to 1 024 site networks and in turn up to 500,000 subscribers. This provides investment protection for the communication system.
The comprehensive range of IDAS products has found favour across the globe, with the largest single user being the US Department of Defense together with the US Marine Corps. This low-cost, low-maintenance equipment is built to withstand the most extreme industrial conditions.
Aside from all the benefits already described, ICOM’s IDAS products also boast a range of innovative new features that make them the most advanced and useful products available.
“We look forward fulfilling our role in improving two-way radio communications in South African,” said Smuts-Steyn. “We will always be on hand to offer world-class products, tailored solutions and as much advice as is needed.”