Modern digital communications systems offer airport operators enhanced functionality and security but the technology is changing at a rapid pace and a next generation system that connects ground and air operations may be on the horizon. Gary Mason reports
The provision of modern communications networks at airports that can support both voice and data exchange in a secure and reliable manner across a disparate range of user groups presents both a challenge and an opportunity for operators.
There are a number of issues to be addressed and it is not just a case or replacing that old analogue legacy system with something shiny and digital.
A typical major airport has 30 to 40 kilometers of facilities. A radio network has to deliver radio coverage to all areas of the airport and users need to be able to roam while they’re talking and still stay connected. There is also going to be a huge diversity of user groups that includes tower and apron control, ground handling services, security personnel, emergency and rescue services, airlines and catering services.
Many of these services and applications are currently provided to mobile users through a mix of VHF (very high frequency) voice and data links, land mobile radio services, and commercial local area wireless networks.
Currently, some airports use outdated radio systems that inhibit modern working practices. The platforms and infrastructures on which these solution operate are also often unable to support newer technologies and are based on obsolete standards. But others have switched to modern digital systems based on TETRA technology that is already used extensively by public safety agencies such as police, fire and ambulance.
Shared talk groups
TETRA – which is based on digital trunked radio technology – provides a secure, guaranteed and dedicated network for its users who can also share talk groups within a confined number of personnel and then switch to other channels in order to communicate with the wider airport community. A key selling point of the technology is its resilience. During a major incident when other commercial mobile networks have gone down through saturated usage the TETRA network will keep operating because it has a limited and specified number of users.
Among those using TETRA systems currently is Aéroports de Paris which shares its professional mobile radio (PMR) network infrastructure with more than 3,000 users at Paris airports – Charles de Gaulle (CDG) and Orly (ORY) – who also share the cost of the system.
The communications network has enhanced security at both sites. For example, the airports have incorporated inspection equipment into their baggage sorting areas and systemised video surveillance posts. Aéroports de Paris inspects 100 per cent of the cargo and baggage in the hold and 50 per cent to 100 per cent of its carry-on luggage. European Union regulations require only that 10 per cent be inspected.
The network allows the operators to let all staff members know immediately if there’s an emergency.
The adoption of digital communications, such as TETRA-based Professional Mobile Radio (PMR) can also open new doors to previously unavailable revenue opportunities. For instance, a single mission-critical radio solution, shared by all entities, can be offered by the airport authority to all ground handlers and airlines – and this service commands a premium price. A digital radio system also has a life span of 10 to 15 years – it is probably the only system at an airport with such a long life span, offering a long-term revenue stream.
But in the fast moving world of mobile communications technology TETRA, while not becoming obsolete, has had its limitations exposed by emerging technologies. In general terms TETRA is very good for one to one voice communications but does not operate over sufficient bandwidth to handle large amounts of data. So, for example, a TETRA communications network at an airport would not be able to stream live video footage to users located in different areas. As a result of these limitations many public safety agencies are considering a migration to Long Term Evolution (LTE) communications technology that has the potential to support both voice and data applications.
The need for data sharing
And greater use of data will become more important to support the shared vision of the FAA’s Next Generation (NextGen) Air Transportation System in the US and Europe’s Single European Sky ATM Research (SESAR) program that require much greater communications between air traffic controllers, pilots, airlines, and airportoperators on the airport surface.
Greater sharing of data requires a broadband (as opposed to narrowband) network to act as the information pipe and this requireds dedicated spectrum – which is a very valuable and limited commodity throughout the world.
In the US there are moves to establish an air/ground communications system that seeks to overcome the limitations of spectrum and the future data requirements of NextGen and SESAR.
In the early 2000s, the International Civil Aviation Organization (ICAO) Aeronautical Communications Panel (ACP) recognized that the very high frequency (VHF) band allocated globally for air/ground voice and data communications for ATM was beginning to reach saturation.
Both had taken steps to significantly reduce VHF channel spacing (from 50 kHz to 25 kHz in the US and from 25 kHz to 8.33 kHz in Europe). This reduction allows more simultaneous voice and data services in the crowded VHF spectrum.
To help increase the capacity and efficiency of US airports, a secure broadband wireless communications system is proposed for use on the airport surface. The system is called Aeronautical Mobile Airport Communications System (AeroMACS).
The first prototype AeroMACS system has been deployed at the Cleveland Hopkins International Airport (CLE) and the adjacent NASA Glenn Research Center (GRC). During the past 3 years, extensive technical testing has taken place to characterise the performance of the AeroMACS prototype and provide technical support for the standards development process.
The system offers the potential for integration of multiple services into a common broadband wireless network that also securely isolates the applications from each other.
The deployment of AeroMACS infrastructure at an airport to enable the migration or augmentation of one of more existing services opens the potential for many additional services, especially those that require wider bandwidth, such as graphical information delivery and video services.
There are a number of potential applications for the system at an airport or port authority that are currently being explored. These include video applications required for safety services (e.g., fixed surveillance cameras and in-vehicle and portable mobile cameras for live video feeds and voice communications with central control during snow removal, de-icing, security, fire and rescue operations). AeroMACS can also help ensure compliance with regulations for safety self-inspection such as reporting the status of airport runway and taxiway lights and monitoring and maintenance of navigational aids and time critical airfield signage.
Virtual Private Networks, or VPNs give an airport access to unlimited voice and messaging communications, while still maintaining individual groups’ privacy using a PMR system.
Some of its functionalities include:
• Group calling capabilities to improve operational efficiency, particularly to groups working on or around an aircraft. Dispatcher priority ensures the dispatcher remains in control of the group, able to interrupt any subscriber in the event of an urgent communication.
• Groups can be created dynamically and instantly. This can be especially important during emergency situations or operations in which different organizations need to communicate.
• Messaging can be provided via SMS services – for example, to send flight updates to the turnaround crew of a flight.
• Communications are seamless between PMR, private branch exchange (PBX), and public telephony (PSTN) systems – as well as unprecedented versatility in data services.