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Traceability of the Evolution of Communication Navigation Surveillance (CNS)

European Union
Complete with results
Project Acronym
STRIA Roadmaps
Network and traffic management systems (NTM)
Transport mode
Airborne icon
Transport policies
Societal/Economic issues


Background & Policy context

The Air Traffic Management (ATM) system is a highly complex and integrated system. For this reason, there is a need to keep track of technical requirements versus the needs of operational processes. The long time frame for development and the international design inputs are key factors that determine the need for tracing the evolution of new system components. One emerging priority is to relate the technical aspects of CNS (Communication, Navigation and Surveillance) to the corresponding high-level requirements at every step of design and implementation, especially as regards economic, environmental and safety issues.


The objectives of TRAFFIC were:

  • to define the requirements for CNS subsystems, clearly linked with previous ATM system definition activities;
  • to provide a consistent mapping between the most recent operational concepts envisaged for EATMS (European Air Traffic Management System) and the requirements for future CNS subsystems (and for the upgrading of existing CNS subsystems);
  • to provide this in an appropriate template with an easy-to-use format;
  • to demonstrate the consistency of the results with the various paths for changes towards EATMS.


Parent Programmes
Institution Type
Public institution
Institution Name
European Commission; Directorate-General for Energy and Transport (DG TREN; formerly DG VII)
Type of funding
Public (EU)


The TRAFFIC project produced and validated a methodology for tracing the evolution of CNS requirements versus the operational concept and context. The application of the method to three study cases (evolution of operational concepts, evolution of traffic in free flight airspace, evolution over the European Civil Aviation Conference area) demonstrated that this method:

  • ensures that all design decisions regarding the creation of the requirement, its changes and its rationale are recorded and accessible to all interested parties;
  • can be used by different users;
  • has a large potential scope for use;
  • provides the capability to trace CNS requirements (what we have, will have or may have) from High Level Requirements (what we need or want);
  • supports the first steps toward a definition of specific ATM systems in operational environments, by identifying the shortcomings and inconsistencies in CNS requirements.

Policy implications

The increase of flight efficiency and safety is a key theme in European transport technology policy. The EU should support the necessary development in technology and procedures, for both aircraft flight systems and air traffic systems, to improve Free Flight operations. This would respond to the airlines’ quest for flexibility and better flight efficiency, especially in areas where the demand for extra capacity is not the major issue.


Ad hoc standards and legislation are required at a European level, especially as regards the transfer of separation responsibility from ground controllers to pilots of suitably equipped aircraft.


Lead Organisation
EU Contribution
Partner Organisations
EU Contribution


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