EU’s aviation strategy is documented in the European Air Traffic Master Plan.

 It builds on the European Airspace Architecture Study describing in detail the planned evolution of the European Airspace. This article discusses the envisioned changes and its implications on the ATSEP's job profile and qualification requirements along the following 4 lines:

  • Outreach
  • Governance
  • Technology
  • Portfolio of tasks

The European Parliament emphasized in its resolution on an Aviation Strategy

for Europe (2016/2062(INI)), that the European airspace is also part of the EU single market, and that any fragmentation will lead to “longer flight times, delays, extra fuel burn, and higher levels of CO2 emissions”. To prepare a “single European sky”, the European Commission delegated the task of developing a proposal for the future architecture of the European Airspace to the SESAR Joint Undertaking (SJU) (see Agreement MOVE/E3/DA/2017-477/SI2.766828). The outcome was  Airspace Architecture Study (AAS) which we discuss in this article.

This article summarizes the shortcomings of the current architecture and introduces the planned interconnected and more service oriented architecture. In conclusion it sheds light on ATSEP’s changing job profile and qualification requirements.


The patchwork of ATM systems in the European air space leads to various system boundaries. The consequences can be grouped into limited capacity and limited scalability and resilience.

Limited capacity

Limiting factors are the non-optimal organization of the airspace - a consequence of heterogeneous and uncoordinated evolution in the various regions over many years. 

There is further only limited use of data communications and automation support, shifting in consequence many tasks to the air traffic controllers (ATCO). 35%-50% of an executive controller’s workload is voice communication. Automation support for controllers is not up-to-date and limited. Services like controller-pilot data link communication (CPDLC) could significantly reduce the controllers’ workload, e.g., through automated routine ATC clearances, and increase safety at the same time.

Limited Scalability and Resilience

Current ATM organization is missing the two key features of modern cloud-based and service-oriented architectures: scalability and resilience.

Legacy architecture provides limited predictability, as many factors that influence the flight’s trajectory are not known before departure (e.g., late arriving passengers, reduced runway capacity due to weather conditions) and during the flight (e.g. conflicts between airborne flights, or changes in the availability of airspace due to military reservations). 

The controllers are continuously resolving such issues. Due to limited capacity, the influencing factors are not known to the ACCs, leading to non-optimal flight profiles and conflict resolution.

Information sharing and interoperability simply do not yet allow automating and optimizing such activities predictively and in real-time adjustments.

The flexibility to use ATCO resources across ACCs is also limited.

Lastly, there are technology-based geographical constraints in ATS provision.

To compensate for the limitations in predictability and create a sufficient level of safety in a context of uncertainty, ACCs have to work with sector capacity buffers, reducing the exploitable airspace capacity even further.

Another factor limiting the flexibility is that ATCO’s are “tied” to a specific sector. They have to service a sufficient amount of hours in this sector to keep the endorsement. Scope for shifting ATCOs across sectors based on capacity-based requirements is limited.

There are further factors like geographical and technical constraints which limit the air traffic service provision. An illustrative example is communication, navigation and surveillance technology using line of sight radio signals. Aircraft need to be within the range of ground equipment.

Factors limiting overall capacity

Non-optimal organisation of airspace

• The current airspace organisation is not yet fully optimised to network flows and makes limited use of cross-border cooperation.

Limited use of data communications

• The current voice-intensive process leads to high saturation of radio frequencies and can lead to voice communications constraining sector capacity.

• More sophisticated interactions between controllers and pilots require datalink communication that can support time and safety critical instructions.

Limited opportunity to create new sectors

• Each sector creation requires a new frequency and there is already limited frequency availability in congested areas.

• Some sectors are already very small and cannot be further split unless creating operational issues.

Limited automation support for controllers

• Current technology deployed in most ACCs does not provide an optimal level of automation that would support extra capacity.

• Limited automation support means significant human effort is still required to manage traffic. The system as a result also lacks scalability to meet growing demand.

Factors limiting capacity scalability and resilience

Limited predictability

• High buffers across the planning and execution phases due to limited predictability reduce the actual usage of existing capacity.

• Lack of end-to-end trajectory optimisation during both planning and execution phases mean that the capacity potential cannot be achieved at network level.

Limited information sharing and interoperability

• Current limits on interoperability and data sharing lead to sub optimisation.

• Suboptimal view and usage of effective available airspace at network level.

Limited flexibility in the use of ATCO resources across ACCs

• ATCO qualification is limited to a number of sectors or combinations of sectors typically within a specific ACC. This limits their ability to support additional configurations that include sectors from another ACC.

Geographical constraints on air traffic services provision

• The location of all (technical) services that support the provision of air traffic control to an aircraft in today’s architecture is tightly coupled to the location of where an aircraft is flying.

• This limits the possibility for an ANSP to provide air traffic services beyond its current area of responsibility.

• It also limits the possibility to share technical services between multiple ANSPs.

Source: A proposal for the future architecture of the European airspace by SJU

Target Architecture to Bring Predictability and Collaboration through Trajectory-based Operations

The airspace architecture study (AAS) designed its target architecture to reach the following main goals:

  • Optimized airspace structure supported by operational harmonization
  • Scalable ATM capacity ensuring safe and efficient air traffic
  • User-preferred routing
  • Reduced inefficiencies and costs
  • Increased resilience to all kinds of incidents
  • Improved civil and military access to the European Airspace

The AAS structured the focus areas of redesign along the problem areas, described in the previous section: Airspace and Capacity as well as Scalability and Resilience (see the figure below).

Focus area 1:

Airspace and capacity

• Optimised airspace organisation – Solutions that support improved design and use of airspace.
• Operational harmonisation - Aligning the capacity of control centres and ways of working to best practices through systematic operational improvements.
• Automation and productivity tools – Increased automation as a progressive enabler of trajectory-based operations (TBO) with short, medium and long-term enhancements to provide increased capacity and predictability.

Focus area 2:

Scalability and resilience

• Virtualisation and ATM data as services - Transition to virtual centres and a common data layer allowing more flexible provision of ATM services.
• Dynamic management of airspace – dynamic grouping and de-grouping of sectors and managing the staff resources accordingly.
• Flight-centric operations where applicable - Changes the responsibility of controller from controlling a piece of airspace to
controlling a number of flights along their trajectories.
• Sector-independent ATS operations - Automation support for controllers to enable provision of ATC without the need for sector specific training and rating. Controller training and licensing to be based on traffic complexity, instead of sector specificities.
• CNS enhancements - Transition to CNS infrastructure and services concept to support performance based CNS and enable new multi-link air-ground communications environment and continued evolution of the Global Navigation Satellite System (GNSS).

Source: A proposal for the future architecture of the European airspace by SJU

This concept means a shift from today’s operational concept to a trajectory based organization (TBO). Flight trajectories will be continuously optimized from start to landing to deliver passengers in time, cost-effectively and as environmentally friendly as possible. The disruptive change will be enabled through a high level of automation in hand with ground-air and ground-ground interoperability and synchronization (ground-ground with adjacent units).

The technical infrastructure needs to be service oriented. This is similar to current industrial internet applications which can be called on and off on demand as a virtualized service. For software-based applications, this means they can scale up on demand. 

Such a service-oriented architecture does not really differentiate between a software application and a primary radar. Every element in the architecture has to provide a service and does this in the form of messages. Everything, whether it is a tower, an antenna or a database application will be virtualized, so that it can be seamlessly integrated into the digital supply chain (rather network) of integrated services across the European Air Space.

To allow for this service-oriented approach, local structures and proprietary solutions and protocols need to be replaced or evolve to connected structures with common data models.

In summary, we can describe the planned “Single European Airspace System” as follows:

  • Network Airspace Operations
    • Seamless operations
    • Dynamic & cross FIR airspace configuration & management
    • Free routes
    • High resilience
  • Air Traffic Services
    • Automation support & virtualization
    • Scalable capacity
  • Data & Application Services
    • Common data models
    • Unified information
  • Infrastructure
    • Integrated & rationalized ATM infrastructure

How Do We Get There?

Rome wasn’t built in a day. And such a disruptive change as planned for the European airspace needs to be sliced down into several steps to remain manageable. 

In the AAS, the transition is divided into 3 subphases.

  • Phase I (until 2025) - addressing short term initiatives for capacity improvement and implementing preparative steps enabling phase II
  • Phase II (until 2030) - Initiation of the service-oriented architecture with the implementation of virtual centers. This shall provide a better platform for increased interoperability and automation.
  • Phase III (until 2035) - True trajectory-based operations after successful transition to service-oriented architecture.


Source: A proposal for the future architecture of the European airspace by SJU

The European ATM Master Plan published in 2020, added a fourth phase, "for the delivery by 2040 of a fully scalable system able to handle both manned and unmanned aviation in line with the joint industry declaration ‘Towards the digital European sky’." This fourth phase reads like a tangible goal, a perspective, to better align the previously defined 3 phases with a specific technical, procedural, environmental and economical goal.

Details of Phase I

We will now have a close look at the short term steps of Phase I as they will impact current ATSEP work and competence requirements.


High-level description

1. ECAC-wide implementation of

cross-border free route, air-ground

and ground-ground connectivity

Air-ground data exchange is essential to increase progressively the level of automation of the ATM systems.

Ground-ground interoperability and data exchange are critical to defragment the technical dimension of ATM operations, and thus to move to the ATM data service provision in a virtual centre context.

Consequently, the successful and timely deployment of the PCP shall focus on these functionalities, together with the implementation of cross-border and cross-FIR free route airspace and advanced Flexible Use of Airspace.

2. Complete airspace re-configuration supported by an operational excellence programme to capture quick wins

Launch airspace re-configuration programme by promoting a collaborative process that would involve all relevant stakeholders. This includes an analysis of areas of inefficiencies at network level, validation activities and delivery of an optimised airspace organisation in compliance with agreed airspace design principles, and based on ECAC wide free-route traffic flows.

This new initiative would be complemented by an operational excellence programme, which would aim at identifying best practices and capture quick wins (through changes in operational procedures, rostering, smaller adaptations to systems, etc.) among all stakeholders and effectively support their implementation to reduce delays.

3. Set up an enabling framework for ATM data service providers, capacity-on-demand service and rewards for early movers, first ADSP is certified

Provide guidelines and an appropriate legal framework enabling the set-up of ADSP and the capacity-on-demand service.
Encourage willingness to implement the new concepts as soon as they are made available.

Source: A proposal for the future architecture of the European airspace by SJU

The milestones 1 is of strong technical character. Milestone 2 looks at the airspace reconfiguration. Milestone 3 is rather on the conceptual side, providing guidelines for ATM data service providers. This milestone is limited to early movers.

Given the technical orientation of this article, we will now have a closer look at the technical milestone 1.

Milestone 1 prescribes the implementation of cross-border free route, air-ground and ground-ground connectivity.

Air-ground connectivity is the prerequisite of progressively increasing the level of automation for ATM systems and reducing the ATCOs workload.

A similarly big task will be ground-ground interoperability and data exchange. This implies that data will be shared across ANSPs. This step is required to defragment ATM operations. It also is a precondition for remote virtual centers.

This comes together with the implementation of cross-border and cross-FIR free route airspace.

This is a major conceptual change as infrastructure will leave the ANSP-centric orientation. Interoperability, connectivity and automation across FIRs, nations and ANSPs have major implications on the requirements to ATSEP.

Technically, the sharing of data and information will be enabled through System-wide Information Management (SWIM), open data layers, standards and common data layers. Read our article on SWIM for more details. The ATM masterplan emphasizes the requirement of system-wide cybersecurity to ensure continuity and integrity of the integrated operations.

Implications and Requirements for ATSEP

Until recent years, the ATSEP’s job profile was focused on locally deployed, often proprietary systems. System monitoring and control was often fragmented, using several proprietary systems. Holistic views were not possible as visibility was restricted to within a specific proprietary subsystem. Also authorization was able to live without complex role-based approaches and segmented authorization.

Seamlessly connected infrastructures raises new requirements to ATSEP along the following 4 lines:

  • Outreach
  • Governance
  • Technology
  • Portfolio of tasks


In a monolithic technical infrastructure, it was completely sufficient for ATSEP to make sure that local systems are available.

The emerging interconnected architecture of implementation phase I is increasing the ATSEP’s outreach to peripheral and external systems. Ground-air and ground-ground data exchange requires the verification of external data availability and validity. System monitoring and control solutions have to meet these requirements.


In an interconnected context, the importance of governance is increasing. As everything is connected, authorization and access to services by ATSEP needs rethinking. Does every ATSEP need to have read and write access to every service? Or shouldn’t it rather be a role-based approach, defining who is authorized to do what. 

This is even more the case, when information comes from and goes outside their own territory, namely from other ANSPs or service providers. Technically we speak of segmented or cascaded structures of authorization of users and user roles.


The nature of technology is changing from a system-oriented to a service-oriented structure. More complex interoperability of systems within and across FIRs requires holistic system monitoring and control (SMC). SMC limited to proprietary systems will not be able to meet the needs of the new situation. For ATSEP, fragmented SMCs in an interconnected service environment will be difficult to handle and may increase the risk of errors.

Technology brings another relevant dimension of change: interconnected systems enlarge the attack surface of a system. And they can also cause accidental system degradations through unintentional disturbances or mistakes. Cybersecurity reaches a significantly higher level of importance. EUROCONTROL speaks of a “data rich and cyber-secured connected ecosystem”.

Portfolio of Tasks

ATSEP are the enabler and gatekeeper of the new technology. They are the ones who accompany change on an operational level and the ones who can best bring feedback on scope for improvement.

In the Easy Access Rules, EASA categorizes the ATSEP competence fields (just like ICAO) into

  • Communication
  • Navigation
  • Surveillance
  • Data-processing / automation
  • System monitoring and control (SMC)

In a service oriented infrastructure, the importance of system monitoring and control increases. 

Many actions which were manual tasks in the past, become control tasks (the “C” in SMC) in service oriented architectures. 

Interconnected systems make the allocation of errors more difficult and at the same time the impact of errors more wide-spread. Data-processing / automation and SMC become the spine of everything.

Given the enlarged attack surface, the task to provide cybersecurity and computer security incident response becomes another major task of the ATSEP. There have been year-long discussions on the level of outsourcing of cyber-security services to external service providers and it would go beyond the scope of this discussion in this article. But the coming denominator in expert discussions is that ATSEP has to play a leading role in managing cyber-security and the Computer Security Incident Response Team (CSIRT).  See our Webinar “Establishing Cybersecurity Structures and Procedures in Air Traffic Control“ for more. 

ATSEP Qualification and SkyRadar’s Training Equipment

ATSEP shall be qualified along the training objectives as specified in EASA’s Easy Access Rules for ATM-ANS, Appendix XIII. But this qualification should happen in view of the emerging new interconnected and more service-oriented architecture: ATSEP qualification should embrace the near future’s skill requirements.

SkyRadar provides ATSEP training infrastructure to qualify ATSEP along the lines of EASA’s Easy Access Rules. The solutions have a strong future orientation.

SkyRadar’s system monitoring and control learning environment enables learning in classical system contexts and in service oriented environments (and in mixed environments which is the closest to reality). 

Students can set up their own systems and the connected monitoring architectures. 

Surveillance architectures like SkyRadar’s NextGen Pulse Radar are fully service oriented and can be connected to the SMC.

Trainees can practice on segmented authorization solutions. Technically it is even possible for several Aviation academies to interconnect their SMC and training infrastructure to practice across territories of governance. 

SkyRadar is currently extending the SMC solution to embrace Incident Response processes and cybersecurity applications.

Let's talk

Contact us to discuss possible solutions for your ATC training center. Calls are non binding and will definitely help shaping your vision for your ATSEP training infrastructure.

Talk to you soon and stay tuned!

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About the Author:

Dr. Ulrich Scholten researched connected data, and internet-based service platforms as scientist at Karlsruhe Institute of Technology (Karlsruhe Service Research institute / AIFB), in conjunction with SAP research and IBM. He has been director of SkyRadar since 2008. His edited and own publications on ATM and cybersecurity find more than 40.000 monthly readers across the world.  

References, sources and copyright statements

This article builds on the document: "A proposal for the future architecture of the European airspace" (2019), by SESAR Joint Undertaking. The table reproduced in this articles have been taken from this documents. All other text builds on this source, but it is a free interpretation and discussion by the author.

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