LONDON Designing a new network infrastructure always calls for a careful comparison between the performance data required by the individual applications and the actual performance results provided by the components planned. The comparison is all the more important when, as in the case of the German Air Navigation Services (Deutsche Flugsicherung), applications have projected life cycles of as long as 15 to 20 years.
The call for a future-safe solution is often accompanied by demands for unlimited functionality and compatibility. Such projects are dependent on reliable data regarding the behavioural performance of the systems under diverse operating conditions which in turn can only be determined using appropriate test scenarios. The DFS (German Flight Security) project for evaluating suitable systems highlights the points to look out for.
Network infrastructures, whether in local applications or wide area environments, are characterised by the heterogeneity of the components implemented. In order to ensure a smooth interaction of systems, recogonised standards must be adhered to.
However, the actual performance data can differ widely due to the varying degrees of further development as well as different interpretation and implementation methods adopted by manufacturers. In both complex and performance-related applications it is vital to ensure a continuous "base" level of performance whilst taking into account the requirements laid down by the application - regardless of the individual elements.
The German Air Navigation Services is responsible for controlling civilian air traffic in Germany. For this purpose it operates four control centres in Bremen, Karlsruhe, Munich and Langen and is also represented at 16 national airports. It employs a staff of approximately 5,300 employees at all locations including Eurocontrol in Maastricht, 1,800 of which are air traffic controllers.
In 2008, DFS controlled exactly 3,149, 591 flights based on instrument flight rules and refers to its impressive statistics regarding safety and punctuality. Despite the increase in the volume of air traffic the number of dangerous approaches has on average continued to decline. Merely one Category A approach was recorded in 2008 compared to 210 in 1975. Over the last few years, more than 90 percent of flights were recorded without delays, the all-time peak amounted to 97 percent.