[Avionics Magazine 04-18-2016] Global air transportation communications provider SITAOnAir is bringing Air-to-Ground (ATG) data link services for aircraft to Air Traffic Controller (ATC) communications in Poland under a new contract with the Polish Air Services Navigation Agency (PANSA). PANSA's collaboration with SITAOnAir going forward will be one of the latest in a series of moves by individual European states to support airline Controller Pilot Data Link Communication (CPDLC).
Air traffic controllers in radar room. Air Traffic Controllers in radar room. Image courtesy of SITA and copyright Monty Rakusen.
SITAOnAir will provide six Very High Frequency (VHF) ground stations and the Aeronautical Telecommunications Network (ATN) routing service to enable CPDLC flight operations under the agreement with PANSA. Each station includes Air Traffic Services (ATS) end system hardware and software, external system standard interfaces, and additional systems elements that include text to speech capability, and Very High Frequency (VHF) voice broadcast equipment. SITA states that the use of its data link communications technology can assist in operational shortcomings that result from large increases in air traffic, such as "controller-pilot misunderstandings, transcription errors, non-standard phraseology and frequency congestion, which are typically associated with the use of voice operations and procedures.”
Poland is the latest member of the European Union (EU) to contract SITAOnAir for the service. In September 2015, ENAV, Italy's Air Navigation Service Provider (ANSP), signed a contract for SITAOnAir
to deploy VHF data communications at 19 airports across Italy. In July 2015, German ANSP Deutsche Flugsicherung (DFS), also began working with digital communications systems engineering company Altys for end-to-end validation testing of its aircraft data link communications infrastructure.
With the addition of PANSA, SITAOnAir is now providing the ground-based infrastructure required to enable CPDLC for 14 ANSPs in Europe.
“PANSA is undertaking an ambitious data link program to fulfill its obligations under the European Mandate for CPDLC. We selected SITAOnAir to provide the air/ground communications service required to support CPDLC because of its well-established track of ATN and [VHF Digital Link Mode 2] VDL Mode 2 service provision throughout Europe. SITAOnAir is providing us an end-to-end service from the aircraft antenna to the interface with the ground air traffic control systems, ensuring consistent and integrated services," Magdalena Jaworska, acting president for PANSA said in a statement regarding the new agreement with SITAOnAir.
Poland is also the second member of the EU to sign a CPDLC infrastructure agreement with SITAOnAir since the European Commission announced a five-year delay to the Feb. 2015 airspace mandate
for the Link 2000+ airspace requirement, which now requires operators with aircraft flying above Flight Level 28,500 (FL285) to equip their aircraft with CPDLC avionics by Feb. 5, 2020. The delay was the result of problems discovered during numerous flight testing activities, which found that there are issues with the ground stations' ability to receive CPDLC messaging.
The Single European Sky ATM Research Joint Undertaking (SESAR JU) released a study in January
that projected the use and capacity of VDL Mode 2 for ATG data communications. The report projected that VDL Mode 2 over a single frequency, which is being deployed by SITAOnAir in Poland, has already reached its capacity limits and that the air traffic system will need to develop the next iteration of data link technology in order to manage the projected use of the system as air traffic increases annually.
"Recently VDL Mode 2 measurements were carried out by Eurocontrol (ECTL). The numbers received from ECTL seem to be reasonable. However, it has to be considered that we are stressing the communication system a lot more with almost every aircraft transmitting data messages. This has a significant impact on radio interference and medium access control protocols. It is known that VDL Mode 2, as such, is not behaving deterministically — i.e., the more airspace users are utilizing the communication link concurrently the more unpredictable VDL Mode 2 becomes," the SESAR JU study notes.
While not commenting on the future possibility of VDL Mode 2 frequency congestion, SITAOnAir does note that its infrastructure will allow PANSA to comply with the Single European Sky 2020 mandate for CPDLC operations.
“PANSA is a key agency in Europe, managing a strategic airspace at the hinge between Western and Eastern Europe. SITAOnAir will provide the ATN/VDL Mode 2 data link communication service to PANSA and contribute to its successful implementation of CPDLC in Polish airspace,” said Fracois Bardin, director of air traffic solutions at SITAOnAir.