How did the EUROCONTROL European Communication Gateway standard come about, and what will be the future use of this state-of-the-art core technology?

Since spring of this year, Germany has been operating its new international message switch Advanced Node for Data Relay in the Aeronautical Telecommunication Network (ANDRA). The system was delivered by German ATC supplier COMSOFT and forms the core of the aeronautical communication infrastructure in one of the highest density areas of European air traffic.

ANDRA is the world’s first system in service to have been developed in accordance with the requirements of EUROCONTROL’s European Communication Gateway (ECG) initiative. As such the system is based on a catalogue of specifications set up by EUROCONTROL and its member states.

On 20 June 2002 the official inauguration of ANDRA took place at the premises of the Deutsche Flugsicherung (DFS) in Offenbach near Frankfurt Airport. During the ceremony Victor Aguado, Director General of EUROCONTROL emphasized the meaning of this technical milestone: ”European air traffic management systems have now taken a step closer to a Single Sky, with the DFS leading the way in bringing an advanced messaging system based on European-wide specifications into operation at Frankfurt today – and tomorrow, in the rest of Europe".

From past to present

Since 1990 programs managed by EUROCONTROL on behalf of member states have been based on strategic objectives like safety, economics, capacity, environment, national security, quality and human commitment. The overruling aim of all efforts was and still is the harmonization and integration of all European Air Traffic Control systems and the development of newly required applications and systems. One of these programs was the ECG.

The ECG was designed to provide an interface between existing and future communications technologies in ATC. Right from the start specifications and requirements were developed in close cooperation and consultation with national Air Navigation Service Providers and industry. As a result of this process a comprehensive User Requirement Document for aeronautical message handling was compiled. The requirements for future systems included amongst others: multiple hardware platforms, interoperability, adherence to industry standards and extension, as well as upgrade facilities.

In a European-wide selection process EUROCONTROL chose the German DFS and French STNA, together with partners in industry, to develop two interoperable systems complying with what was now called ECG standards. DFS selected COMSOFT from Germany, which subsequently developed ANDRA, the first system worldwide to be fully compliant with the ECG requirements.

The ECG supplier

COMSOFT GmbH is a medium-sized company located in Karlsruhe, Germany that focuses on ATC and offers their expertise to a broad range of customers. Since its start in the ATC domain in the eighties the company has continued to launch innovative and cost-effective products. Common characteristics of all COMSOFT delivered systems are the use of open architectures and internationally agreed standards wherever feasible.

COMSOFT has in the past continuously proved its leading position in the field of Message Handling Systems implementing their latest technology in high volume and high density areas of European air traffic. Among others, COMSOFT supplied the national and international message switches of The Netherlands, of the United Kingdom and of the EUROCONTROL Upper Airspace Control Center(UAC) in Maastricht. With ANDRA COMSOFT now equips also a forth of the major traffic areas in Europe with their technology.

Outside Europe several countries in the Middle East and Southern Africa have taken advantage of COMSOFT equipment to modernise their regional message switching networks at low costs with high reliability and performance.

The ECG product

ECG offers gateway functions to all kinds of aeronautical data, is fault-tolerant, scalable and expandable in all components and allows portability to all mainstream system platforms.

All new systems and applications in the message handling area should in the future comply with the ECG requirements as defined by the EUROCONTROL member states. Therefore the ECG core software uses COTS products as much as possible to reduce cost. Also, the software is portable and flexible enough to fit into a wide range of technical environments.

ECG architecture is modular in nature and configurable for fault tolerant and scalable systems. It provides a multitude of physical interfaces and protocols, comprising among others the currently most employed X.25, TCP/IP, CDIN and AFTN protocols and formats.

In addition, ECG supports upcoming communication protocols, such as AMHS, X.400 and SMTP, forming the basis for the future ATN (Aeronautical Telecommunications Network). The layered software architecture further facilitates horizontal and vertical extensions of various kind. In particular the system is open to be complemented with new protocols, new system features and new or extended application functions.

Two major systems supplied by COMSOFT for European administrations can be taken as references for ECG-based technology and are described in the following sections. The two systems in their different stages of operability are ideal for demonstrating the flexibility and adaptability of the ECG software package for different environments.

ANDRA

The first air traffic control service provider that received an ECG system is the German DFS. It uses the ANDRA system as the national and international message switch of the country. ANDRA makes use of a multi-processor board-based platform variant of the ECG. Figure 2 gives an overview of the system architecture.

ANDRA consists of a core system with duplicated units, recording systems with duplicated recording subsystems, operator workstations, print servers and printers. An internal LAN connects the different system components. The COMSOFT system is fully redundant with two sites in the Frankfurt vicinity backing up each other. Each site can use the complete overall functionality.

ANDRA/ECG's centre functionality provides reception, transmission, forwarding and assembling/disassembling of aeronautical data messages originating from connected adjacent centres and national subscribers. German airspace is known for its high traffic density and, consequently strictest requirements for reliability and performance are met.

ANg1

In April 2002, COMSOFT was awarded the contract to deliver a new Message Handling System for EUROCONTROL’s Central Flow Management Unit (CFMU). The CFMU is located in Brussels and is responsible for the air traffic flow management in the ECAC airspace. CFMU’s future communication gateway will be called “Access Node – new generation – 1 (ANg1)”.

ANg1 represents a further reference for an ECG-based system. Again, the COMSOFT ECG architecture was chosen to implement this central component of European ATM. The use of the ECG core software for the demanding properties as requested for the ANg1 is a proof for the ability to cater to customer-specific extensions.

ANg1 will form the gateway between aeronautical messages originating from connected adjacent centres and the CFMU’s internal systems. ANg1 supports currently used protocols and data formats in the AFTN/CIDIN/ATN and SITA networks as well as in the CFMU network, e.g. TCP/IP and CFMU format. As such, the ANg1 implementation gives a further indication of the inherent flexibility and extensibility of the COMSOFT ECG architecture, also allowing to the inclusion of dedicated proprietary protocols of existing infrastructures.

Similar to the ANDRA setup as described above, two locations are foreseen for the installation: Haren in Brussels as main centre and Brétigny in Paris as contingency site. A total of four ANg1 systems will be delivered, two to each site, one of them being the operational (OPS) system and one being used for development and test purposes (DEV).

A main characteristics of the ANg1 implementation is its strong inherent redundancy, coupled with a rich functionality over hardware and software, including high performance recording systems. The employed ECG software supports the current aeronautical fixed services (CDIN/AFTN) and future networks (AMHS/ATN).

From present to future

In the above described reference applications, the ECG core software proves to flexible enough to match a wide range of different user requirements and internal architectures. At the same time ECG stands for a standard product guaranteeing smooth communication with all external partners.

These advantages are due to the fact that ECG’s development was based on common Europe-wide specifications. Through the consultation of stakeholders involved ECG has proved to be a cost-effective gateway between existing and future communication technology.

Today ECG is emerging as the standard product in the field of aeronautical message handling - a common European Communication Gateway for the future.