Talking TETRA for operational gains

Instances of airports switching to the digital TETRA mobile radio systems are on the increase, but does this system offer a worthwhile improvement over existing technologies?

The current increase in demand at many airports makes now an appropriate time to examine improving the use of existing resources and systems. A good place to start efficiency improvements may well be the communications system. When looking at an existing system, your motives may either be to continually replace faulty parts, or to upgrade and utilise new technology for the potential operational benefit of the entire airport.

Communications are undoubtedly an important factor in running an efficient and effective business. However an airport can be considered unique in that it contains many different companies and teams, each with individual communication requirements. For example, air traffic control, airport management, security staff and catering businesses. Although working to the same goal; the smooth and timely departure and arrival of aircraft, these groups will often benefit from the increased sharing of knowledge and easier, faster and more reliable communications.

TETRA, as an open and secure standard for mobile communications, offers to fulfil this role. According to the TETRA MoU Association the transport sector is the second largest user segment for the technology, with the number of airport applications growing. What the TETRA industry claims is driving this uptake is best observed by reviewing the technology it employs and the applications it makes possible.

Roots of the technology

TETRA (Terrestrial TRunk Radio) was created as a wireless communications technology for use by emergency services in 1989 by the European Telecommunications Standard Institute (ETSI). Since then it has been developed for use in other sectors such as the military, utilities and transport.

Due to its roots in the emergency services, the technology offers several advantages when compared to similar technologies, such as GSM. These include: improved reliability and dependability in emergency situations; the clarity of voice communications against noisy backgrounds (e.g. runway aprons); digital communications and increased functionality. This functionality is manifest mainly in the areas of secure encryption, simultaneous voice and data communications and the emergency call outs that the technology offers.

Communication on a TETRA network takes place in one of two ways; either ‘full-duplex’ or ‘half-duplex’. The former allows a normal telephone conversation to take place and allows the reception of calls from alternative networks; the latter is similar to a typical radio conversation and allows calls to be made simultaneously to a set network of handsets.

A major advantage of the technology mooted by its advocates is its cost relative to other technologies. TETRA operates on a lower bandwidth then similar systems, enabling larger broadcast areas from base stations, meaning less base stations, which means lower operating costs. David Gray is currently chair of ETSI’s TETRA board, after working for Motorola as its Director of TETRA marketing. He sees the adoption of TETRA in airports as making simple business sense. “The uptake of TETRA for airport applications is based on its services and facilities best meeting user requirements, balanced with value for money, as well as the benefits of TETRA being an open standard,” he says. Being an open standard means that a competitive choice of systems and terminal suppliers can be offered to the end-user.

Of course other technologies can be and still are purchased by airports, such as Analogue MPT1327 Trunking, Tetrapol and Conventional Analogue FM. However, Gray still believes that word-of-mouth experiences between airport authorities, as well as other publicity, is helping TETRA become the preferred technology for airport applications. Furthermore, applications in the airports industry are beginning to demonstrate its usability and flexibility in the field.

Oslo’s early experience

Having grown out of a European standard, the first airports to employ the technology are in that region and the very first to implement it in everyday operations was Oslo Gardermoen, in December 1998. After seven years of use Tore Myhre, IT Manager at Gardermoen has found that the technology meets their needs and sees no reason to change to another system. He emphasises the technology’s ability to efficiently utilise the frequency band, without having to use dedicated frequencies/channels to specific user groups, as a particularly useful function for his airport. “Due to this, the administration of users is easy to manage,” he says. “We also use TETRA for data communications, but on a limited scale.”

However, he does report one deficiency – communication between the control tower and vehicles operating on the runways and taxiways. Myhre states that the inadequacy is related to the voice quality. “Speech is in many cases considered garbled and in some cases difficult to read, something that is not acceptable from a safety point of view for this particular use,” he says. “Part of the problem is also the time delay of fractions of a second, which is not popular amongst controllers used to analogue communication with aircraft.” The airport is therefore still using analogue UHF communication for communication between the tower and vehicles.

A TETRA system has also been installed at Brussels International Airport. Brussels is an important business hub in Europe with more than 15 million passengers using the airport in 2004 and more than 19,000 ground staff. Geert De Mesmaeker, head of Service Communication, Belgocontrol, was involved in the decision to replace the old analogue trunking system. According to De Mesmaeker the upgrade was needed because replacement parts were becoming difficult to source and maintaining the handheld radios was proving too costly.

The system was installed in 2005 and consists of three sites covering the entire airport, with a capacity of 1000 users for both voice and data communications. “For the moment we are rolling out the handheld radios. We use the Motorola MTH800 handheld radios and the system is performing very well,” De Mesmaeker says. “Audio quality is very good, especially in noisy environments. The radio coverage, also indoors, is very good.”

With no problems as yet De Mesameker feels that, considering the lower costs, the flexibility and voice and data features, the system will prove to be a good investment. “It offered us a future-proof network that is capable of expansion to other Belgian airports when necessary. We know that we can also add features, such as object call, in the future,” he concludes.

Another European airport that recently installed the technology is Salzburg Airport W.A. Mozart. The airport, billed as Austria’s Alpine gateway, uses the system for operations, excluding ATC. The equipment was again delivered by Motorola. Ramp operations, fire & emergency, Duty Officer, central infrastructure and catering are all connected via the TETRA computer system.

According to management at the airport, the main benefit is clearly during the peak hour operations. On a charter Saturday in winter, 25,000 pax are handled in one day with 220 ATC movements on the list. During these busy days, TETRA with its switch between available frequencies, is vital for communications. Salzburg’s Executive VP of Technical Services, Rudolf Lipold, says that TETRA has had only positive results for day-to-day ramp operations. Furthermore, he says that having a representative of the system provider available to assist when it is first switched on is wise, especially for airports new to the system, because solutions to any problems are made-to-measure and often discovered when the system is actually in use.

Handset functionality

TETRA was also selected for use at Aeroports De Paris’ sites in Paris, to serve the needs of its airports: Charles de Gaulle, Orly, Roissy and le Bourget. The system has been implemented by ADP subsidiary ADP Telecom. Joel Dumontet, marketing manager at ADP Telecom said about the new network: “Security was one of the main reasons behind our choice of TETRA to replace the analogue system. We also appreciated the Virtual Private Network solutions, the flight-specific application and the ease of integration.”

Flight-specific applications are an example of the kind of functionality that can be deployed via a TETRA network. Air France’s recent adoption of Sepura’s sGPS handportables and mobiles at Roissy-Charles de Gaulle Airport is one such instance of a flight-specific application being employed in the field. The Sepura handportables and mobiles used by Air France are using bespoke software for airport users that allow the use of data from existing airport systems. This data provides an interface that in turn allows users to connect instantly with all of the different teams assigned to a specific flight. This can benefit the operational aspects of running an airport; simplifying work processes and communications.

The future will see the continuing development of handsets and terminals, fuelled by the open nature of the standard. Equipment is evolving in terms of size and usability with functionality coming to the fore. For instance, returning to Oslo airport, replacement handsets over the years have provided further benefits. “We have gradually replaced some of the handsets with newer models, providing better battery capacity and smaller size. Replacement has primarily been due to wear and tear in a rough environment,” says Tore Myhre.

Functions such as short data services that eliminate the delays associated with paperwork, integral GPS for the automatic locating of workers and packet data enabled handportables and mobiles that offer connectivity to back office IT systems are currently available. Further to this suppliers such as Sepura are promising WAP enabled handportables in 2005. The company also states that on the mid-term horizon is TETRA 2 for enhanced data speeds.

Global adoption

The technology can now also be said to be expanding its horizons beyond Europe. Other regions of the world are beginning to utilise the technology. In the Middle East Dubai International announced an extension to its existing network in February this year. In Asia the new Bangkok International Airport will be built with a TETRA system installed by M-Link Asia, Motorola’s distributor in the area. A contract to supply the radio communications network for the Ji’nan International Airport in the Shandong province of China was also announced in November last year by Nokia, marking the first of its kind in the burgeoning Chinese Avitaion market. John Cox, CEO of the TETA MoU Association, sees TETRA on a global scale. “We now believe that TETRA can realistically be called a global digital PMR standard. If people are now putting TETRA in as first fit in airports, it has clearly achieved a position within the industry. We also believe that recognition of this is growing,” he says.

However with the first application seven years ago, an industry-wide revolution has not manifested itself. He attributes this to safety issues. “Typically the safety environment is slower at adopting new technology and that is reflected in TETRA for airports. An airport’s priority has to be safety, so there have been wait and see attitudes. However it’s starting to pick up now because people have seen it in use,” Cox says.

He also believes the safety factor may have currently become a driver for increased adoption. “One of TETRA’s strengths is that all parties use common frequencies, with their own private networks for everyday use. If a big incident occurs they can pull them together and deal with it as an incident,” he says. Combine this with the terrorist threat looming over airports and the fact that more than half of all TETRA sales are to public safety organisations and TETRA again makes good sense, this time from the safety perspective. “If there is a terrorist incident on or nearby to an airport, it becomes part of that incident, but not solely. Civil organisations have to become part of that airport too. It makes good sense to adopt a technology common with those organisations, particularly if it is also well suited to use for airport ground operations.”

The efficient solution

In terms of efficiency, Cox believes that the basic technology is very strong. Use of trunking technology improves spectral efficiency by placing all users onto one trunk. He also believes TETRA has a long life, being virtually the only global PMR standard. In terms of passengers, he believes the ability to keep people informed in a busy and dynamic airport environment is key to effective management. “The technology is well suited to airport operations. The ability to communicate clearly and easily with everyone involved is very important. The faster things happen the more important communications become and TETRA meets those needs.”