According to Regulation (EC) No 549/2004 (the framework Regulation), interoperability means a set of functional, technical and operational properties required of systems and constituents of the European air traffic management network (EATMN) and of the procedures for its operation, in order to enable its safe, seamless and efficient operation. Interoperability is achieved by making the systems and constituents compliant with the essential requirements.
Regulation (EC) No 552/2004 (the interoperability Regulation) is focused on the interoperability of systems, constituents and associated procedures of the EATMN. It aims to ensure that new validated concepts and technologies can be introduced timely and efficiently. The following eight domains are addressed :
- aeronautical information services,
- airspace management,
- air traffic flow management,
- air traffic services,
- communications,
- navigation,
- surveillance, and
- meteorological information.
According to the interoperability Regulation, the regulatory materials are organised in three layers :
- the Essential Requirements (ER) are part of the interoperability Regulation itself, that is the highest level of legislation,
- the Implementing Rules (IR). The aim of an IR is :
- to complement or to refine the Essential Requirements,
- to give a reference which systems, constituents and associated procedures shall comply with the requirements,
- those rules shall facilitate the coordinated introduction of new, agreed and validated concepts of operation and technologies.
- the Community Specifications (CS). This third layer is outside the mandatory part of the regulatory material. Application of Community Specifications or other technical specifications remains voluntary, and manufacturers and air navigation service providers are free to choose any technical solution that provides compliance with the essential requirements. However, compliance with the Essential Requirements and/or the Implementing Rules for interoperability shall be presumed for systems, together with the associated procedures, or constituents that meet the relevant Community Specifications and whose reference numbers have been published in the Official Journal of the European Union (OJEU).
The below diagram depicts the layering of regulatory materials, stemming from the basic objectives to the detailed operational and technical specifications :

In general, a Community Specification may either be :
- a standard for systems or constituents and is drawn up by the European standardisation organisations (CEN, CENELEC, ETSI) in cooperation with EUROCAE on a mandate from the European Commission, or
- specifications on matters of operational coordination between ANSPs drawn up by EUROCONTROL on request of the European Commission.
So far, the following "Community Specifications" have been adopted and published in the Official Journal of the European Union :
Organisation | Reference and title of Community Specifications | Reference of superseded Community Specification | OJEU Reference | Application date (or date of cessation of presumption of conformity of superseded Community Specification) |
ETSI | EN 303 214 V1.2.1 Data Link Services (DLS) | EN 303 214 V1.2.1 | 1 January 2014 | |
EUROCONTROL | Spec-0106 Edition 4.2 EUROCONTROL Specification for On-Line Date Interchange (OLDI) | Spec-0106 Edition 4.1 | 14 November 2012 | |
ETSI Standard to be downloaded from ETSI.org | EN 303 213-1 V1.4.1 Advanced Surface Movement Guidance and Control System (A-SMGCS); Part 2: A-SMGCS Level 1 including external interfaces | EN 303 213-1 V1.3.1 | 1 September 2017 | |
ETSI | EN 303 213-2 V1.4.1 Advanced Surface Movement Guidance and Control System (A-SMGCS); Part 2: A-SMGCS Level 2 including external interfaces | EN 303 213-2 V1.3.1 | 1 September 2017 | |
ETSI | EN 303 213-3 V1.1.1 Advanced Surface Movement Guidance and Control System (A-SMGCS; Part 3: a deployed cooperative sensor including its interfaces | October 2010 | ||
ETSI | EN 303 213-4.1 V1.1.1 Advanced Surface Movement Guidance and Control System (A-SMGCS); Part 4: a deployed non-cooperative sensor including its interfaces; Sub-part1: Generic requirements for non cooperative sensor | October 2010 | ||
ETSI | EN 303 213-4.2 V1.1.1 Advanced Surface Movement Guidance and Control System (A-SMGCS); Part 4: a deployed non-cooperative sensor including its interfaces; Sub-part2: Specific requirements for a deployed Surface Movement Radar sensor | October 2010 | ||
ETSI to be downloaded from ETSI.org (search query: "A-CDM" or "Single European Sky" | EN 303 212 V1.1.1 Airport Collaborative Decision Making (A-CDM) | June 2010 | ||
EUROCONTROL | Spec-0136 Edition 2.0 EUROCONTROL Specification on the Air Traffic Services Message Handling System (AMHS) | Spec-0136 Edition 2.0 | Corrigendum | 18 September 2009 |
EUROCONTROL | Spec-0112 Edition 1.1 EUROCONTROL Specifications for the application of the Flexible Use of Airspace (FUA) | Spec-0112 Edition 1.1 | 10 January 2009 | |
EUROCONTROL | Spec-0107 Edition 3.1 EUROCONTROL Specification for ATS Data Exchange Presentation (ADEXP) | Spec-0107 Edition 3.0 | 1 January 2014 | |
EUROCONTROL | Spec-0101 Edition 1.1 | Spec-0101 Edition 1.1 | 1 March 2014 | |
EUROCONTROL | Spec-0100 Edition 2.0 | Spec-0100 Edition 2.0 | August 2007 |
In addition to those published Community Specifications, work on standards has been in progress or still needs to be initiated at CEN and ETSI, based on "standardisation mandates" from the European Commission to the European Standardisation Organisations, in the following areas :
- Mandate M/390: Software Assurance Levels (SWAL) - prEN 16154
- Mandate M/408: Ground Based Augmentation System (GBAS) Cat. I precision approach operations; Approach Procedures with Vertical Guidance (APV) - APV-SBAS (LPV)
- Mandate M/510: Aerodrome mapping data
- Mandate M/524: Air Traffic Management (ATM) interoperability for the ATM Master Plan
So far, not all achieved results are mature for adoption as Community Specifications but on-going standardisation work and the content of the mandates are reviewed on a regular basis.