Way beyond blue lights

TETRA has become the standard technology for public safety communications, replacing old analogue networks. The technology, by design, is suited to those deployments but is increasingly being used by organisations that operate in haza

Way beyond blue lights

The applications for TETRA go way beyond blue light services deployments as the need to communicate in even the most inhospitable and hazardous locations becomes critical. From its roots in the public safety sector in Europe, the technology has now become a global standard and has a raft of wider commercial applications outside its traditional markets. TETRA is deployed in airports, manufacturing sites, explosive environments, power generation plants and confined areas, bringing communications capability to new markets.

‘Public safety is still the main area of use for TETRA but we’ve seen a large spread of its uses,’ says Håkan Samuelsson, chief technology officer of Axell Wireless. ‘The transport area is one large area for TETRA and we’ve also seen increased usage of TETRA within manufacturing facilities, for confined area coverage and in markets where the need for explosion safe equipment is required.’

Heidi Hattendorf, director of business development and product marketing at Motorola, sees a similar development path. ‘The whole basis of TETRA takes into account the mission-critical environment, ‘ she says. ‘The whole technology was born around that. TETRA is always going to be effective when it comes to addressing incidents and, when you come to the devices, they’re easy to use with gloves or single-handed, the displays are designed for various types of lighting conditions and meet a wide variety of safety requirements.’

Samuelsson also sees the range of devices on offer as a key driver for the market’s push into hazardous commercial situations. ‘Today there are quite a few manufacturers of handheld units dedicated to TETRA and that meet hazardous area requirements,’ he adds. ‘We’ve installed equipment in car manufacturing plants. In Germany, all the big car manufacturers use TETRA for their production and the energy industry is a big user of TETRA.’

TETRA has had success in such hazardous areas because of the functionality it offers, along the with the safety factors built into TETRA terminals. ‘A lot of the requirements of industries are met by TETRA, ‘ adds Samuelsson. ‘It offers quick call set-up time and users can decide to call individuals or groups. It’s very quick compared to short messaging and the terminals, in general, are much more ruggedised. For instance, I haven’t seen an explosion-proofed GSM phone and I know many of the TETRA terminals are the same or better in that respect.

In addition, the safety-oriented thinking that already exists in the TETRA community is an added advantage.’

Standard TETRA functionality gives it several advantages in hazardous environments. ‘TETRA’s strengths are very much around advanced and enhanced quality of calls,’ says Matt Greatwood, head of business radio at Arqiva. ‘Typically hazardous locations involve a lot of background noise caused by plant and machinery operating. TETRA cuts out that background noise. In addition, our deployments, which use infrastructure from Damm and devices from Motorola or Sepura, are purely deployed over an IP network. That means customers can use their existing infrastructure such as private DSL and gives the advantages of multi-site calling where before leased lines were required at significant cost. Also TETRA can be used for duplex telephony. Users can utilise the radio as mobile phone and call an extension, another radio user or a cell phone.’

Greatwood gives an example of TETRA being used to at five power stations which are then linked using an IP network. ‘They can be linked easily and that gives enhanced operator benefits, ‘ he says. ‘For instance, an electrician at one site can speak to one at another using their TETRA radio without having to return to an office and use the PBX.’

The power generation market is a significant one for Arqiva, which works with several electricity generation companies that run gas, oil and nuclear facilities. ‘The advantage of TETRA is that such systems are quite old now and TETRA solutions can be deployed that are comparable in price to an analogue trunk network, ‘ says Greatwood. ‘TETRA also addresses businesses; needs to enhance security, usability and resilience. Power station environments certainly want to put in resilient networks.’

Greatwood also points out that TETRA service providers are becoming more astute in the ways in which they offer services to commercial organisations. ‘We provide two solutions to the market,’ he says. ‘Either we sell a complete package of equipment and provide ongoing maintenance for that or we provide a managed infrastructure service where we provide the equipment, installation, training, project management and site maintenance over a longer period of time such as a typical five-year contract. We can literally provide off-the-shelf infrastructure and spectrum countrywide supported by our national field force, centres of excellence and centralised monitoring and service management.’

The explosion-proof capability is one of TETRA’s most compelling advantages. The technology is compliant with the EU’s two ATEX directives, which became law in July 2006. One addresses the user of the equipment and the other addresses the manufacturer and requires that employees must be protected from risk of explosion in areas with an explosive atmosphere. The ATEX 95 directive covers the equipment and the ATEX 137 workplace directive sets out minimum requirements for improving health and safety protection of workers potentially at risk in such environments. Employers must classify areas where hazardous explosive atmospheres may exist into zones. The classification given to a particular zone, and its size and location, depends on the likelihood of an explosive atmosphere occurring and its persistence if it does.

‘Our ATEX terminal meets the specification to work in an explosive environment such as in the oil and gas industry or in fire environments, ‘ says Hattendorf. ‘We meet both the degree of dust and water levels acceptable and that’s critical in fire situations where there is dust as well as water.’

Greatwood sees the need for ATEX-compliant devices but also points out that TETRA enables the use of ATEX and non-ATEX devices across sites that may only have small or partial truly hazardous areas. ‘In such environments there is a greater duty of care placed on employers so the functionality that can be built into TETRA and seamlessly provided for lone worker safety, in man down situations and with applications such as mapping are critical advantages,‘ he says. ‘However, in a power station you may have a gas burner to heat the oil to fire up the generator and only that area may be hazardous so there is a smaller requirement for ATEX-compliant equipment. TETRA is ideal because it can address that truly hazardous environment – which is defined under the ATEX standards – and support the rest of the site and users with non-ATEX equipment.’

However, it’s not just directive-compliant devices that make TETRA such an effective solution. Coverage is another critical point, especially in confined areas. Finnish TETRA repeater manufacturer, Creowave, points out that while a TETRA base station signal usually covers almost 100% of open areas, signal levels from base stations are sometimes too weak or do not exist at all in order to ensure the full functionality between the base station and a TETRA radio user. To enhance this coverage, various TETRA repeaters are a solution and, in hazardous areas, the enhancement of coverage is often vital because an explosion, for example in a mine or an oil refinery, can cause significant damage and even loss of life. Prevention of releases of dangerous substances, which can create explosive atmospheres and preventing sources of ignition are two widely used ways of reducing risks.

Creowave has deployed repeaters in hazardous environments where large meta

Written by Wireless magazine
Wireless magazine

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