PMR

Critical communications – reliable radio

Wireless communications isn’t just about 3G, 4G or 5G mobile communications. Two-way radio, in the form of TETRA, is still going strong and, as Vaughan O’Grady finds out from two companies active in the African market, very relevant in Africa.

SRG3900 mobile TETRA radio.

TETRA (SHORT FOR TErrestrial Trunked RAdio) is a professional mobile radio and twoway transceiver specification. Although it has been around for a long time (the first network was launched in Norway in 1997), TETRA remains a relevant technology for many industries around the world.

It’s widely used by government agencies, emergency services and a number of private industries. As for why it is still relevant, Nicolas Hauswald, CEO of Etelm and Tim Mills, sales director – overseas co-ordination, Sepura, are in a better position than most to explain.

Critical communications specialist Etelm is active in the African market, most notably providing TETRA networks in the transport and oil and gas sectors. Sepura is known for the development and supply of radio terminals, accessories and applications for TETRA-based mission-critical and business-critical communications.

Explaining TETRA’s continuing popularity, Hauswald says, “TETRA is widely accepted by the users – and this is key. Users will not change easily when they are happy with a solution, especially if change has a heavy cost. The technology remains the answer to many required communication challenges as it offers a level of reliability that no other wireless technology on the market can bring.”

Mills adds, “TETRA is trusted as the international standard globally. This means that experience and knowledge can be shared between countries and market sectors. Public safety and sites of critical national infrastructure often rely on vast national networks that take a lot of time, investment and planning to replace.”

No new standards have been established for these that would make them suitable for critical communications, and so, Mills, like Hauswald, concludes, “TETRA is an accepted standard, trusted by millions, which delivers on the voice and data requirements of users in the sector.”

While critical communications tends to be where TETRA is most relevant, its precise use tends to vary, depending on the region. For instance, while TETRA is used for public safety in Africa, it not as widely used for this purpose as in Europe, where it’s a long-established standard for emergency services. However, says Mills, “National forces use the technology in North Africa, and the South African Police Service are large users.”

African countries primarily use the platform in transport, airports, utilities, oil and gas and major events. Examples include the new Mauritius Metro (where Sepura partner Consort Digital has just deployed a complete

“New TETRA networks are being deployed and TETRA still has a long life ahead”

communications solution), the World Cup in South Africa in 2010, and many utilities plants.

Mills says, “A site that has critical security requirements is typical of those that operate a TETRA network. Hence even some national wildlife reserves employ TETRA and benefit from functionality such as GPS positioning, clear audio and the ability to transfer images and other data across the network.”

He continues, “For transport users, the ability to have a flexible network is of huge benefit; maintenance and station staff benefit from the clear audio, which can be crucial when working in a busy or noisy environment, while the mobile radio can integrate with existing systems and share telemetry data over the network.”

Transport is certainly one area where Africa stands out. As Hauswald says, “Etelm supports a number of TETRA projects in urban transport, such as tramways, which are mainly located in North and West Africa. We also supply coverage to a number of industrial train lines in these regions too – for example, mine trains.”

Etelm, as we have noted, focuses on radio infrastructure. “We provide a core network and the devices are very often purchased by different routes. This includes devices for voice

communications, such as portable radios, as well as small sensors with TETRA modems.”

Sepura, by contrast, primarily supplies TETRA terminals for vehicles and for personal use, together with the software that adds specific functionality to the radios. “This can include many different forms, dependent on the user requirements,” says Mills. “For example, access to secure databases, sharing of imagery, dispatcher tools, connection to additional devices or similar.” He adds: “Together with our sister company Teltronic, Sepura can provide complete, scalable solutions for critical communications users.”

As Hauswald points out, use cases – mostly critical communications – are quite similar all around the world. “What differs most,” he says, “is the integration of the TETRA system into a wider system – for example mixing technologies such as LTE. Certain regions are more advanced in their use of new communication standards or have chosen to take particular routes, such as the [LTE-based] Emergency Services Network (ESN) project in the UK.”

Sectors do differ, however. Outside the UK and one or two other countries, TETRA is less widely used by public safety organisations. But it is used in many different sectors. Mills says, “One of the key reasons is the sheer size of many of these operations – for example a main train line can run for several thousand miles. Here TETRA’s advantages come to the fore: resilient devices tested to work in extreme, tough environments; clear audio in noisy environments; scalability – meaning a network can cover a specific facility or work

“There is no reason to believe that TETRA will not be the leading critical communications platform for many years to come”

across a long distance; and integration with existing IT systems.”

He adds, “Use around the world can differ for many reasons – availability of spectrum, budget, infrastructure and resources to deliver the product. These can all be sporadic across a region as large as Africa.”

So where do these two experts see TETRA going in Africa? Hauswald says, “We see TETRA continuing to have a strong presence, especially in public safety, transport and the utilities and the oil and gas sectors. New TETRA networks are being deployed and TETRA still has a long life ahead.”

He suggests, however, that there will be more focus on integration over the coming years as more LTE networks emerge in the region – and this is an important point. The UK is one market where TETRA will eventually give way to LTE (though there is ongoing debate about how and whether this will involve public networks and shared frequencies).

Hauswald explains, “LTE has a lot to bring thanks to its wider bandwidth (video, telemetry, IoT support, etc). But,” he continues, “it comes with a cost and hasn’t shown the same reliability in the field as TETRA so far. The cost comes with the fact that, quite often, the frequency band is higher than the one of TETRA so it means that you need more radio sites to

The Sepura TETRA family.

New Mauritius Metro train units. The fleet vehicles are equipped with Sepura SRG3900 TETRA mobile radios.

cover the same area. The cost of a radio site is quite high.” Either way, Etelm intends to be ready. “Our portfolio offers the possibility to have a smooth migration from TETRA to LTE as both technologies can work together on a fully integrated network.”

Mills says, “TETRA will continue to support users across the key sectors of transport and utilities/oil and gas, as well as public safety in places. As in Europe and around the world, there is no reason to believe that TETRA will not be the leading critical communications platform for many years to come. This is why users in Europe, North America and across Asia are continuing to invest in major systems to support their operations. The [UK’s] Metropolitan Police recently confirmed that the reason they chose to invest in Sepura was ultimately because “voice is king”.”

But data is now also part of the equation. TETRA radios are tough and reliable with an increasing capability to use data in innovative ways. As Mills points out, “Across the world customers are looking at an intelligent use of data over TETRA networks, including aiding reporting on network coverage, aiding control room understanding of live operations and connecting to additional devices or networks. This is a huge area of growth for the industry, to help organisations operate more efficiently, and keep staff safe and communicating securely.”

There might even be a role for TETRA in smart city infrastructure. Hauswald, who recently wrote a blog on the topic (available on the Etelm website) says, “In practice, this could mean a rail operator using a TETRA network for core voice communications across the transport network serving the smart city. This would cover mission-critical operations such as the communication between driver and stations or signalling staff. Then an LTE overlay – to connect with other aspects of smart city infrastructure – could offer high-bandwidth data communications for real-time passenger information apps for example, delivering the high-quality passenger experience expected as part of genuinely smart cities.”

Even after more than 20 years, it’s clearly too early to write TETRA off just yet. ✆