The aviation industry is adopting AMHS (Air Traffic Services (ATS) Message Handling Services) to support ground to ground communications for services such as flight plans and meteorological data. This will eventually replace the current AFTN (Aeronautical Fixed Telecommunication Network) and CIDIN (Common ICAO Data Interchange Network) based systems.

AMHS-based systems are now being deployed around the globe with a large majority of countries who have so far made the switch, using solutions from Isode partners, based on Isode servers and APIs.

What Isode Provides

Isode provides servers and APIs used in building an AMHS Infrastructure:

  • Isode's M-Switch X.400 is an X.400 MTA (Message Transfer Agent) that provides the core message switching services and connects to external systems.
  • Isode's M-Store X.400, a robust X.400 Message Store for storing messages.
  • An AMHS Gateway API enabling the development of AMHS Gateways to AFTN or CIDIN following the specifications in the ICAO SARPs for provision of an MTCU (Message Transfer and Conversion Unit).
  • An AMHS Client API enabling the development of AMHS client applications connecting to M-Switch using X.400 P3 or to M-Store using X.400 P7.

Solutions based on the Isode AMHS products offer a number of benefits including full ICAO SARPs Conformance (Isode's solution is the first to be conformant to the Extended ATS Message Service, and the first to provide a conformant ATN Directory), Fail-over clustering support for all components and Directory based configuration management providing flexible client/server configuration.

AMHS Architecture

AMHS provides a distributed message switching and storage infrastructure, to enable transfer of ATS messages, such as flight plans, NOTAM (Notice to Airman) and Meteorological information. The AMHS service is accessed by users, using AMHS terminals, and applications (such as Meteorological applications), in order to exchange ATS messages. AMHS Terminals and AMHS Applications connect to the AMHS infrastructure using X.400 protocols as shown in the diagram below.

AFTN Transition and Co-Existence

As ground to ground messaging moves from AFTN to AMHS, it is important that full connectivity is maintained. This is achieved by use of an AFTN/AMHS gateway, which is formally known as an MTCU (Message Transfer and Conversion Unit). MTCUs are critical to enabling full connectivity while both AMHS and AFTN are being used.

MTCUs are available from Isode partners. Isode provides the AMHS side of an MTCU, to enable development of an MTCU.

The ATN Directory and Extended ATS Service

AMHS defines two services:

  • The Basic ATS Service, which provides functionality equivalent to AFTN.
  • The Extended ATS Service, which provides additional services and functions, including security based on digital signatures; binary attachments; large attachments.

The Isode servers and integration APIs provide full support for both the Basic and Extended ATS Service. A key element of the Extended ATS Service is use of the ATN Directory. Isode provides a full set of products for constructing an ATN Directory solution.

Isode's AMHS Servers also make use of Isode’s M-Vault directory server for configuration information, and so directory will be used as a part of all Isode AMHS systems.

Further Information

For further information on the overall architecture of an AMHS solution, see the AMHS Architecture page. Isode has written a number of whitepapers that give more information AMHS:

  • Why use a P7 Message Store? Getting X.400 messages to and from end-users
    The goal of this paper is to give an understanding of what an X.400 Message Store, such as Isode’s M-Store X.400 does, and where and how it should be used. In order to do this, the paper looks at general requirements for sending and receiving (X.400) messages, and looks at various approaches that can be taken.
  • Why X.400 is good for high reliability messaging
    X.400 was specified in the 1980s, with the expectation that it would be the universal standard for email. While this did not happen, X.400 is still used for many applications, particularly where high reliability is required. This paper summarizes the key features of X.400 that make it good for applications needing high reliability, with particular focus on capabilities not available with Internet email.
  • AMHS Security
    The Aeronautical Traffic Services (ATS) Message Handling Service (ATSMHS) defines a set of security services for use as part of the Extended ATS Message Service for providing that ATS Message Handling System (AMHS). This White Paper describes these security services, how they are provided and how they can be deployed. The paper concludes that AMHS Security is needed now, and should be pursued urgently as a part of AMHS deployment.
  • Delivering the ATS Message Service to the End User using AMHS
    AMHS (Air Traffic Services (ATS) Message Handling Services), as specified in the ICAO ATN (Aeronautical Telecommunications Network) SARPs, is the new standard for ground to ground messaging communications. The "ATS Message Service" is the end to end message service that AMHS provides. AMHS specifies the service, and the underlying infrastructure that is used in order to provide this service. To build a complete system, the ATS Message Service needs to be provided to end users, sitting at terminals. This paper looks at various approaches to doing this.

Several of the Isode partners also have excellent information about AMHS on their Web sites. Training on AMHS is available from two companies: