The industry debate regarding the supremacy of DMR over dPMR appears to be quietening down as the market recognises that each technology has its own merits, but in the view of Monique Princen, solution marketing manager at Tait Radio Communications, DMR has the potential to be the dominant standard.
‘Tait views DMR as the best suitable digital radio standard for operational critical networks, especially in those situations where cost efficient wide area coverage is important,’ she says. Princen points out that DMR was defined by ETSI as the digital replacement for MPT voice networks but, because DMR provides extensive data capabilities as well, its suitability in today’s radio networks is set to reach well beyond the current MPT installations.
‘It is our firm belief that where the mission critical radio market is dominated by either P25 or TETRA, DMR can be the dominant standard for operation critical networks such as those found in transport, industrial radio networks and utilities, for example.’
Princen describes two key advantages that DMR has the potential to deliver to customers. The first is that DMR provides excellent data capabilities in the standard for both short data requirements like messaging and AVL, as well as large data messages using IP data. The second is that the technology provides two communication channels in 12.5KHz spacing, therefore effectively doubling the radio network capacity for many customers. ‘Digital voice is an obvious improvement compared to the analogue systems most of our customers are still using,’ says Princen.
When DMR is compared to TETRA and P25 phase 2, which both also provide spectral efficiency and data, there is a difference in that DMR is not designed only for one specific target market – public safety. Numerous features in the P25 and TETRA standard have been defined with public safety requirements in mind and therefore don’t allow for the flexibility that other markets may desire.
Princen thinks there is scope for both DMR and dPMR depending on the nature of the network deployment. ‘DMR can be deployed in the existing 12.5KHz channels which makes migration from the existing technology easy,’ she says.
‘Customers do not need to change their frequencies and can achieve the desired 6.25KHz spectral efficiency that many regulators aim for. dPMR using FDMA cannot reuse the existing frequencies and cannot fit two channels in one 12.5KHz channel spacing as the frequencies will interfere when used on the same site. Tait does believe dPMR is better suited for smaller networks with limited infrastructure, largely depending on peer-to-peer or direct mode connections.’
Princen also feels that the debate between narrowband radio systems versus cellular is a different argument and concentrates, in the company’s view, around three issues: data capacity; public versus private networks; and cost.
‘In almost all of the traditional radio markets there is an increased demand for mobile data applications,’ she says. ‘The current applications have been designed for broadband networks and therefore require a bandwidth that exceeds the capabilities of a narrowband network, regardless of the technology.
‘Tait believes that, with the deployment of digital narrowband technologies that provide good performing standardised data transmissions, many applications can and will be optimised to be usable on a narrowband network. This will allow the customer to have critical data applications running on their narrowband network to improve their efficiency and safety.’
For Tait, the public versus private networks debate concentrates around the quality of service, reliability of the network and lifetime. Where a common requirement for reliability for a private network is 99.999%, this is not achievable by any public network. It is also expected that a radio network will be operational for at least 15 years, and most have a lifetime of 20 to 25 years, while the public cellular networks change technology every five years.
‘While the customer does not pay for the infrastructure, the cost of replacement of terminals due to a technology upgrade often exceeds the infrastructure cost and interrupts the service of the customer’s business,’ she adds.
The final argument is cost. ‘For a public network, the customer does not pay for the installation and maintenance of the infrastructure, but instead pays for the usage,’ explains Princen. ‘Over the lifetime of a network, the operational cost can easily outweigh the initial investment. If a customer would choose to install his own private cellular network, the cost of coverage far exceeds the cost of a narrowband network as the number of sites required can be up to ten times the number of narrowband sites to achieve the same coverage. And this does not even take into account the licence cost and availability of frequencies.’
Moving away from the technology debate, Princen believes that the recession and its effect on public spending in many countries is altering the way in which wireless solutions are sold. ‘The recession has resulted in a lack of funding for replacement networks and as a result, organisations try to extend the lifetime of their current system or look for optimisation of networks and increase the usage of the networks,’ she says.
‘As a supplier of communication solutions it is now even more important to understand how your solution can provide the maximum support for the primary objective of the customer. For example, how can a network for a utility improve the efficiency and response times of the organisation, or how can a police network improve call out times and safety of the officers?
It also makes sense to look at gradual replacements and integrate legacy equipment in the new network. Actively working with a customer on a good ROI for the wireless communication solutions, still results in the customer finding the funding for the investment.’
That also necessitates a change in approach in terms of offering radio solutions as a service. ‘Tait has certainly seen an increase of service requirements at its customers,’ confirms Princen.
‘In many cases, this is due to the fact that the customer no longer has a dedicated radio department and the IT department lacks the knowledge and expertise to efficiently operate and maintain a radio network. There is also an increase in customers who want to concentrate on their core business – and supporting radio networks is not part of their core business.’
However, not everyone is jumping on the services bandwagon. ‘There is still a group of customers for whom it is financially more attractive to own the network or where the network is critical to their business and therefore they have to be able to control it fully themselves,’ she adds.
‘Tait will therefore provide on the next generation radio networks – of which DMR is the first one – an extensive network management system that provides a single platform for managing and maintaining the network, the security and provisioning. The functionality of this system and the user interface are more aligned with standard IT tools and allow control of the network to be carried out by non-radio engineers.’
Looking to the future, the greatest change will be the acceleration in the demand for data communications among users. ‘This increase in data demand will automatically result in demand for better management tools, excee