High-quality data communications capabilities are essential enablers to reach the efficiency and capacity improvements required by the Single European Sky. The SESAR Joint Undertaking (SESAR JU) has published a study of a VDL Mode 2 capacity and performance analysis in order to identify when there is a need to introduce the next generation of datalink. The study represents a key input to the strategic development of the European datalink infrastructure.
The “VDL Mode 2 capacity and performance analysis” study, aimed at identifying the time horizon by which the VDL Mode 2 datalink technology (assuming usage of up to 4 frequencies) would reach its operational limits in Europe. Commissioned by the SESAR JU and conducted by a partner consortium[1] between June 2014 and July 2015, the study has the following main conclusions:
- VDL2 over one single frequency has already reached its capacity limits. Therefore, multi-frequency deployment in Europe is a “must” as of today;
- A 4 frequencies implementation is a minimum requirement to support VDL2 deployment until 2025 in high density area;
- Further optimisation options under investigation may extend the viability of VDL2 over 4 frequencies beyond 2025 in high density area;
- It is highly recommended to anticipate the evolution of the European datalink infrastructure in the ATM Master Plan and to prioritise the development of the next generation datalink technology within SESAR.
The current mandated solution for air/ground data communications in Europe is based on VDL mode 2 technology[2]. Concerns over VDLM2 performance degradation led the European Commission to request EASA to investigate. The resulting EASA report[3] included a ten point action plan involving proposals for simulations, performance assessment campaigns, flight trials and deployment planning, to enable an informed decision on the future of VDL M2.
The SESAR JU also launched a second study, “VDL Mode 2 measurement, analysis, testing and simulation campaign” (also referred to as the ELSA Consortium study), upon request from the European Commission. It addresses the EASA recommendations 1 to 6 related to the identification of the problem root cause and the provision of potential fixes. It aims at further analysing the end-to-end VDL Mode 2 issues experienced today, defining potential technical solutions for multi-frequency deployment and VDL Mode 2 potential improvement. Commissioned by the SJU and conducted by a consortium of ATM stakeholders, the project started in February 2015 and is due to deliver the final report mid-2016.
In summary, the results of the Capacity and Performance analysis therefore confirm the need to introduce the next generation datalink system in the coming ten to fifteen years given the current configuration, which is consistent with the 2015 edition European ATM Master Plan and the SESAR 2020 work programme. The VDL Mode 2 measurement, analysis, testing and simulation campaign will try to address current problems and maximise the operational period of VDLM2.
[1] Aena, Airbus, Air France, DFS, DSNA, easyJet, ENAV (lead), LFV, Lufthansa, NATS, SITA, University of Salzburg.
[2] Regulation (EC) No29/2009 as amended by Implementing Regulation (EU) 2015/310
[3] http://ec.europa.eu/transport/modes/air/single_european_sky/doc/implementing_rules/2014-04-23-easa-datalink-report.pdf