EUROCONTROL was requested by ICAO EUR/NAT Air Navigation Planning Group (EANPG) to develop and operate centralised off-line management functions to support the Common ICAO Data Interchange Network. For that purpose, Pulsar has developed in 2001 the CIDIN application, allowing operators to design and plan their communication network. Such a network was using CIDIN or AFTN protocols.

After several years of successful operation, CIDIN needed to be extended in order to support the new ATS Message Handling System (AMHS) protocol. This need for AMHS off-line management functions gave birth to the AMC (ATS Messaging Management Centre) application.

Project Scope

AMC is a Web application designed for managing an aeronautical off-line communication network in a collaborative way. It allows describing COM centres’ characteristics and planning changes. Operators can define connections and routings between COM centres using 3 distinct protocols. The application helps checking the consistency of the network and finding other paths in case of failure. An interactive map is used to represent the so-defined network. Different kinds of reports are also available.

Main Concepts

Network Protocols
The protocols management is backward compatible, each one encompassing the previous one.

Organizations

• CMC: CIDIN Management Centre, where CIDIN management functions are carried out, based at Eurocontrol, maintaining the central repository
• AMC: ATS Messaging Management Centre, replacing CMCs
• CCC: Co-operating CIDIN/COM Centre ; COM centres participating in network management activities
• COM: Communication Center with physical elements (switch)
• ICAO International Civil Aviation Organisation

• EANPG: European Air Navigation Planning Group
• EATMP: European Air Traffic Management Plan
• ANSP: Air Navigation Services Provider
• ATS: Air Traffic Services
• AMHS: ATS Message Handling System
• ATN: Aeronautical Telecommunications Network
• AFSG: Aeronautical Fixed Service SubGroup
• MD: Management Domain (covering one or more COM centres)

 Functions

• Implementation planning
• Inter-working test support
• AMHS PDR monitoring (potential defect reports) - renamed into “Monitoring of AMHS Documentation Maintenance”
• Download support information
• Helpdesk function
• View operational data
• Administrative functions (e.g., enter contact information to help AMC users).

The main purpose of AMF-I functions is to provide support to states that are in the process of implementing AMHS, and do not yet have AMHS in operational use. However, they may also be used by States that have already started operational use of AMHS, e.g. to plan future evolution of their AMHS systems.

• Network inventory
• Network planning (merged within network inventory)
• Routing management
• Address management
• AMHS user capabilities management
• Security management (not yet implemented – future function)
• Statistics
• Support / Helpdesk

AMC Network
The AMC network is made of 2 layers:

• all physical telecom connections binding the COM Centres all over Europe, called the Network Inventory.
• the routing of messages on this network, called the Routing Directory.

Network inventory: describes all the physical elements allowing to route a message.

Routing Directory: indicates only 1 communication route at once, step by step (hop after hop).

Connections
A connection (formerly “circuit”) is the physical link joining 2 COM Centres.

Routing cost
The path of lowest cost must be selected at each COM center, at each connection, according to the occupancy rate of the band width. This algorithm is no more used. The choice is made manually.

• VCG Virtual Circuit Group
• Primary Virtual Circuit
• Secondary Virtual Circuit

A maximum of 6 VCG can be created between 2 COM centres, one for each combination of:

But the screen allows managing only CIDIN VCG’s, the VCGs for AFTN & AMHS are managed automatically by the application for technical reasons.

• the main path is followed by default
• the alternate path is used in case of failure with the main path

• the existing path is the current path
• a planned path is a path that may change according to the specified even type

COM Chart
It is a graphical representation of the network (routing excepted) with graphical facilities allowing to draw tunnels or to create fully meshed islands directly thru interaction on the map.
The AFTN/CIDIN COM Charts give primarily a view of physical connectivity between COM Centres in the selected area (the selection is made on the chart name). The charts show the number of circuits, line speed, etc. This includes CIDIN VCGs implemented over interconnected Packet-Switched Networks (PSNs), which, strictly speaking, are not physical circuits, but may be considered as such by simplification.

Fully meshed island

The fully-meshed topology of the target AMHS network will lead to a very high number of AMHS connections. The individual representation of all these connections would lead to an extremely unclear, not legible, diagram. Hence the need for a specific representation of a fully-meshed AMHS island.

AMHS connections are different because a variety of underlying networks can be used, including shared accesses connectionless IP networks. In this technical environment, there is not a constant binary capacity or throughput identified for each AMHS connection. The representation of AMHS connections in the COM Chart is therefore limited to logical aspects, i.e. to the existence of an AMHS association between two COM Centres. Each COM Centre must be associated to one or several COM Charts in the Network Inventory screen in order to be displayed in these charts.

Areas

An area is a logical unity for manipulation of data. The use of different areas allows people to work in a secure way on his/her data by acknowledging their correctness.

There are 3 areas: the background area, the pre-operational area and the operational area.

Edition is done by Com Center Operators (CCC) only in background area. The general purpose of the Pre-Operational Data Area is to display to Network Managers (CMC) data regarding all COM Centres, before these data become live at the end of the cycle when they are transferred to the Operational area.  In order to show changes, information is shown in red colour in the Pre-operational Area if the information is different from the corresponding information currently in the Operational Area. The general purpose of the Operational Data Area is to display operational data for the current cycle. to everybody involved in Network Management accross Europe.

AMHS MD Register (Management Domain)
This sub-function provides high level information registered for every AMHS MD worldwide. 

Path Function
Function allowing to visualize a path (a path is made by one or more routing).

It also allows searching for another path by simulating a situation where a COM center is out of service or where a routing between 2 intermediary COM centers fails.

ANP Location
ANP Locations follow a naming convention which is ICAO compliant

• Official  = real ANP location
• Unofficial  = places that need to be designated inside the network. They are named as they were ANP location but they aren’t.

Unofficial Territories are added to the ICAO database by Eurocontrol. In AMC when there exists an official and an unofficial ANP location with the same code the unofficial take the precedence.

A special procedure was developed to compare the locations in use in AMC with the updated data of ICAO and to manage the synchronization within AMC.

AMC Regions
Each COM center can be associated to a region from the Network Inventory screen. The list of regions is initially loaded in the database with the same names as the basic COM charts. A link allows to display a COM chart which name matches the region code. Users can also be associated to a region from the Region screen.

Persons
The Persons are all the people involved in the maintenance and update of the AMC data. This represents the relationships existing among the different organizations involved in the AMC Process. The roles of a person are the administrative functions this person can endorse. They are not related to a specific COM center.

Routing Inconsistencies
It is an algorithm that allows detecting the missing routings when trying to reconstruct a path. It tries to follow all routes and detect the points where a hop is missing.

Network Planning
All information concerning the future modifications or remark on the network inventory and the routing direction. It was merged with the inventory thanks to the attributes existing or planned.

AIRAC Cycle
An AIRAC Cycle is a recursive temporal cycle of 28 days. The data transfer between areas is done according to the AIRAC cycle.

Collaboration
bulletin board = information from AMC to CMC
forum = links between questions and answers
support function = screens with FAQs and interworking problems

Reference Tables

These functions enable the AMC Operator to manage:

• the list of personal roles used in AMHS MC Contacts or Network Inventory persons & contacts
• the list of COM Centre functions and CIDIN addresses
• the list of connection protocols
• the values available for User Capabilities
• and other reference codes & system parameters.

User Rights
The menu item “Assign Function to User Groups” allows granting access rights by group or by function.