Comsoft’s Günter Hellstern shares the lessons learned from an ambitious AMHS (Aeronautical Message Handling System) project.

In 2002, Eurocontrol commissioned Comsoft to provide the CFMU (Central Flow Management Units) with the 4 central Message Handling Systems ANg1 to replace the previously used nodes AN1. CFMU, with its central locations Brussels-Haren and Paris-Brétigny, supplies all Eurocontrol member states with the Air Traffic Flow Management (ATFM) services, and therefore plays an important role for the European aviation. Due to CFMU’s special tasks and responsibilities, the special demands on the ANg1 system could not be mastered by any off-the-shelf message handling system. On the other hand, the project schedule was very tight, as the time range for the replacement of the previous systems was very strictly defined. This example of ANg1 shows that customers with special operational tasks or a developing infrastructure indeed have the need for major adaptations of the standard messaging software package. Yet, it is well-known that recycling of complex software solutions and adapting to customer specific requirements normally is a difficult task. But Comsoft’s AIDA/ECG package, with its inherent expandability and modifiability, proved to be the right basis for ANg1 and allowed for a speedy realisation of the ANg1 system.

As a means to reduce the risk on schedule the project was divided into two releases: At the end of Release I, ANg1 was ready for operation, and Release II, handed over for acceptance tests in autumn 2004, provided additional features. Comsoft was therefore able to actually recycle the existing software, to modify and enhance it, and finally to produce an outstanding message handling system that covers the requirements of the customer within the agreed, very short project deadlines. Beside those software developments that only CFMU benefits from, future systems based on ANg1 incorporate a multitude of features and properties that are of strong interest also for other customers.

The following list is by no means complete: The enhanced message routing and queue management features ANg1 has implemented allow the user to reprocess messages not only within the AFTN,CIDIN, SITA, and AMHS networks, but also to reroute messages across the borders of a gateway. If, for instance, messages cannot be transmitted to a communication partner via X.400 for the moment, both new X.400 messages to be transmitted andX.400 messages that are already queued, can be rerouted via AFTN and CIDIN. This feature is not only of advantage for a central message handling unit like CFMU, but also for national COM Centres that intend to migrate their Message Handling Systems from AFTN to AMHS. The system can be connected to the SITA Type B network via BATAP/EMTOX and BATAP/MATIP. It is possible to operate several systems(e.g. the operational and the contingency site) from one single central workstation, even if each system is located at a different site. The systems are interconnected via protocol-independent message transfer facilities, a central Software Configuration Management, and a remote HMI to support the central administration.

ECG’s PC systems with integrated serial interfaces and Multibus II systems were substituted by the highly-scalable Comsoft Serial Network Link (SNL) technology. This SNL technology allows linking virtually any number of redundant serial interfaces via LAN to powerful standard server clusters. As each SNL module incorporates a processor of its own, the system performance increases with each interface that is added. Comsoft decided to change the operating system, and ported the software from UnixWare to future oriented LINUX. The resulting combination of LINUX with Intel-based standard servers offers the possibility of upgrading the systems any time, i.e. whenever a more powerful hardware component is to be added. Even with their AIDA/ECG software the realisation of the ANg1 system was a challenge, even more so if one considers the given time frame to develop the new system.

A considerable contribution to the project’s success was made by the customer himself: The small but most competent multi-national project team from Brussels gave outstanding support with their practical experience and detailed ideas of the system design and architecture. Constructive discussions and thorough testing, both ending in mutual understanding and utmost satisfaction, kept standards high and resulted in a system which exceeds even high demands in usability and performance.

On the occasion of the ETFMS project in 2003, Comsoft already had provided CFMU with four node systems AN3 to collect and distribute surveillance data from the Eurocontrol member states for the CFMU host systems. Now, in theANg1 project, it was possible to link the four ANg1 systems via the Comsoft network management solution ESMS with the AN3 nodes and with the Entry Nodes, spread all over Europe, in order to supervise these systems centrally.

The ANg1 project perfectly shows that the implementation of customer-specific demands into existing software does not necessarily pose an unsolvable problem. On the contrary, it is manageable if the basis product was preliminarily designed to be modifiable and expandable as is the case with AIDA/ECG. If then, as with theANg1 project, customer and manufacturer work on a team-like basis, the project has no other choice but to succeed. The new benchmark set byANg1 is sure to be of interest for future customers: These enhancements will partially be of benefit also for future users of the AIDA/ECG systems, as theANg1 system is a definite enhancement compared to the sole ECG functions and features. Because of this flexibility, AIDA/ECG will be able to keep pace with future developments and the requirements resulting thereof.