ATM Voice

Voice ATM communications include all voice applications used for the purposes of Air Traffic Management (air-ground communications, co-ordination and transfer, emergency, Search and Rescue, flow management, capacity planning).ATM voice covers intra- and inter- centre (all types of ATSUs: ACC, APP, TWR, MIL, NMOC) communications and also ensures the connectivity between the centres and the ground radio based stations on the ground leg of the Air-Ground communications between controllers and pilots.

Until recently, inter-centre voice ATM communications were mainly based on analogue (ATS-R2) and digital (ATS-QSIG) protocols. For the ground component of the air-ground communication there was no common standard defined, as all communications between ATC centres and ground radio stations were point to point and no network was needed.

The Single European Sky package II (SES II), enforced by the European Parliament and the European Council on 4 December 2009, requires a more efficient operational concept based on functional airspace blocks (FABs). Within an FAB, there is a need to effectively deliver capacity to airspace volumes when required. To do this, airspace and sector structures must have the ability to adapt to predicted traffic flows and workload without delay or restriction. Furthermore, adjacent units must know the sector configuration of all the surrounding FAB partners. Dynamic sectorisation is required to support this new concept.

To achieve dynamic sectorisation, new flexible technical solutions are needed for which interoperability is an essential ingredient. The VoIP in ATM standard is the ideal solution to provide interoperability, particularly for the air-ground component where a ground radio station will be shared by several adjacent ATC centres belonging to different air navigation service providers (ANSPs).

Furthermore, a number of European telecommunication service providers (TELCOs) are planning to, or are already phasing out, analogue and digital 64k circuits. These circuits are currently providing the supporting infrastructure on which the ATM voice services are based. This situation in the TELCO market is affecting both civil and military ANSPs. A replacement of current analogue and digital ATM voice services with a common standard is therefore urgently needed at the European level. VoIP in ATM is able to provide the right replacement at the right time.


Voice over Internet Protocol (VoIP)

EUROCAE WG-67, with cooperation from EUROCONTROL, European industry, and ANSPs, developed the first VoIP in ATM standard. The standard was issued in February 2009 as a set of documents (ED136-138) defining the operational voice concept, the interoperability solutions and the network- associated requirements. A new version of the standard (ED137B) was released in February 2012 after a review which included integration of requirements from the U.S. Federal Aviation Administration (FAA).

These documents are numbered ED 136, ED 137B, ED 138 and consist of:

  • VoIP ATM System Operational and Technical Requirements (ED136)
  • Interoperability Standards for VoIP ATM Components (ED137B)
  • Network Requirements and Performances for VoIP ATM Systems (ED138)

ICAO Aeronautical Communication Panel Working Group I, responsible for the development of the ICAO Aeronautical Telecommunication Network over the Internet Protocol Suite (IPS) standards finalised the inclusion of VoIP requirements into ICAO DOC 9896 by making a reference to the Eurocae specification on Interoperability Standards for VoIP ATM Components.

A EUROCONTROL European Single Sky Implementation (ESSIP) objective for VoIP in ATM became active in 2011 for the European Civil Aviation Conference (ECAC) States. The deployment is planned to be initiated in January 2013 for both inter-centre telephony and the ground segment of the air-ground voice communications. The migration of the European ATM voice services to VoIP is forecast to be finalised by December 2018 for inter-centre telephony and by December 2020 for the ground segment of air-ground communications.

To support the European-wide ATM voice communications transition towards VoIP, EUROCONTROL launched the VoIP Implementation and Transition Expert Group (VOTE) in February 2010. VOTE has the generic mission to address VoIP in ATM implementation and transition-related issues on a case-by-case basis; and to identify solutions and deliver recommendations to interested parties (e.g. ANSPs, industry, TELCOs and standardisation bodies).

EUROCONTROL finalised the VoIP in ATM Test case specification which consist of the following set of interconnected documents:

  • VoIP in ATM cross-reference matrix
  • Telephone Test case specification for VoIP in ATM
  • Radio Test case specification for VoIP in ATM
  • Recorder Test case specification for VoIP in ATM
  • SIP v ATS-QSIG Interworking Gateway Specification
  • SIP v ATS-R2 Interworking Gateway Specification
  • VoIP in ATM Test suite specification - High Level Description of VoIP in ATM Test Cases.

The documents are available on the VOTE OneSky Team Library on the EUROCONTROL extranet.

EUROCONTROL further developed the VoIP in ATM test suite called VOTER, an essential element to facilitate timely multi-vendor VoIP implementations. VOTER version 2.0.0. has been released in April 2013.


Previous ATM Voice activities:

Very Small Aperture Terminal (VSAT)

VSAT is a geostationary satellite communication system operating in Ku Band (10 -14 GHz) for ATM purposes. A VSAT Network was deployed over the Black Sea area in 1997, providing reliable ground-ground voice communications between the adjacent Air Traffic Control Centres of 4 bordering States. The novelty of this project was to make use of VSAT technology in an Air Traffic Management environment providing both operational and contingency voice services for the direct benefit of Air Traffic Controllers.  


Air Traffic Services Q-Reference Point Signalling is profile standard for digital voice communications as defined by ECMA Standard 312. ATS-QSIG had been developed by EUROCONTROL for the use of a digital signalling system (QSIG / PSS1) in ATM ground voice communications networks. Initially, standardised by ECMA, it has been adopted by ETSI as a European Norm (EN) EN 301 846. Voice related guidelines documents are available on request.

Further information

Further information

  • ESSIP Website
    For further information on the European Single Sky Implementation (ESSIP).
  • VoIP in ATM ESSIP Objective (pdf)
    For further information on the Implementation of Voice over Internet Protocol in ATM ESSIP objective (COM11).
  • ATM VOICE OneSky Team
    For further information on the AGVN database. Limited access to registered OneSky Team AGVN State Focal Points.
  • VOTE OneSky Team
    Restricted space for the members of the VoIP in ATM Implementation and Transition Expert-group (VOTE).
  • AGVN web-database application
    Restricted web-application for the ICAO/EUR AGVN State Focal Points. Request for access shall be addressed to EUROCONTROL DNM/COO/DCO/CFC.



Mr Liviu Popescu