It’s no secret that our skies are becoming choked with air traffic and, with the global economy set to recover in the not too distant future, the situation can only get worse. Europe’s air safety body EUROCONTROL, expects the number of flights to double and the number of passengers to grow by nearly 5% a year between now and 2020 – in airspace that isn’t getting any bigger.

This is putting an unsustainable strain on air traffic management (ATM) systems, which are now in dire need of a wholesale revamp. Crucial to this revamp is the adoption of satellite-based navigation and communications technologies to allow aircraft to operate more autonomously.

Which technologies to adopt, at least in Europe, has been the subject of the ANASTASIA and now NEWSKY and SANDRA projects, set up under the auspices of the EU’s Single European Sky (SES) initiative and its SESAR (Single European Sky ATM research) programme.

Completed in June 2009, ANASTASIA (airborne new advanced satellite techniques and technologies in a system integrated approach) was not a development project in itself but concentrated on recommending a set of technologies that would be achievable from 2010.

“EUROCONTROL, expects the number of flights a year to double between now and 2020.”

These are not new technologies but Frost & Sullivan aerospace and defence programme manager Balaji Srimoolanathan says that the object was never to invent something new. “Projects such as ANASTASIA are more a case of evolving existing technologies to the next level – the real challenge is to integrate them, for now and the future,” he says.

Appropriate technologies

One such technology is that based on the Inmarsat satellite constellation. Thousands of aircraft already use Inmarsat’s Classic voice and datalink services but the aim is to migrate oceanic and continental ATM systems to the SwiftBroadband (SBB) service, Inmarsat’s aeronautical version of its broadband global area network (BGAN).

SBB is already used for passenger internet and in-flight entertainment services but Inmarsat says it could also be in use for cockpit safety services in oceanic airspace as soon as 2012. SBB currently supports high and intermediate-gain antenna systems, the type used on transoceanic flights, so existing avionics would need only small changes.

Its use in continental airspace though is further off, however, because the satellite network needs to be modified to enable SBB to work with onboard terminals using low-gain antennas (LGAs) – hardware that’s cheaper than its oceanic variants, as well as smaller and lighter, allowing it to be installed in all aircraft types.

Using LGAs means ground networks will also need to be modified, for example to maintain connectivity during the turning and banking manoeuvres typical over continental airspace, and to provide the shorter message latency and higher reliability demanded in continental operation. And this will take time.

Filling the gap

In the meantime the NEWSKY (networking the sky) and SANDRA (seamless aeronautical networking of datalink, radios and antennas) projects are tackling integration issues.

“Satellite-based navigation technologies to allow aircraft to operate more autonomously.”

NEWSKY, which finished in October 2009, developed the concept of a mobile aeronautical communications network, based on internet technologies for cockpit and cabin services.

It integrates the terrestrial and satellite data links to which aircraft will soon have access – links such as those in the VHF and L band for overland routes, WiMAX for airports and the Inmarsat satellites.

Instead of using individual communications systems for the various aviation control areas and applications, NEWSKY has proposed network solutions to integrate these systems, supporting the trends towards the use of internet technologies based on IPv6 and a growing emphasis towards data communications and away from voice communications.

SANDRA, which runs until 2013, extends this work and aims to design, implement and validate an integrated aeronautical communications system based on an open architecture, a common set of interfaces and industry standards. The integration is being addressed at four levels – service, network, radio technologies and antenna.

The service level, as the name suggests, means the full range of services for airline and cabin crew operations, in-flight and ground-based services as well as airport, security and ATM-related operations. Network integration takes up the IPv6 baton and uses it as the final unification point while addressing interoperability with technologies such as ACARS and ATN/OSI to ensure smooth transition.

At the radio level, technologies such as VHF, WiMAX and BGAN will be integrated into an Integrated Modular Radio platform, a software-definable system that selects the required bandwidth for a given application at any point during a flight.

This will allow these standalone systems to be fitted as a single unit, cutting the size, weight and cost of the equipment – an approach already adopted in the choice of LGAs. To this end, SANDRA is also developing hybrid Ku/L-band satellite communications antenna technology.

Given the open systems model, the technology will be independent of the type of aircraft and hardware. According to Srimoolanathan, the regulatory framework is of as much concern as the technological one. “The key strengths in this area are the availability of base-level technologies, which can be developed to address the needs in the short term,” he says.

“For the moment, the US players seem to be ahead of the European companies in terms of technology.”

“The key challenge, however, is how the broader SES initiative will be managed on a prolonged basis across the different borders and regulations of the EU. The dynamics of the regulations across the countries in the EU is an interesting area, not least because the regulations need to be constantly updated.

“Also, the integration of military and civilian airspace [a key aspect of the SES] could open up new challenges in terms of regulations as well as protection,” Srimoolanathan says. He adds that of these projects, SANDRA is the one that could help this aspect of integration.

In terms of the technologies for managing and maximising the use of our airspace, it’s very much a case of today Europe, tomorrow the world. “The rest of the world is looking at this work in the EU with keen interest, ultimately with a view to a global roll-out for it,” Srimoolanathan says.

That could prove good news for EU companies but Srimoolanathan says it is not a guarantee. “Opportunities for European companies depend completely on their capability to provide effective solutions at the right time. For the moment, the US players seem to be ahead of the European companies in terms of technology.”