Introduction of Pattern Oriented Software Concepts in Ground Stations

Kurzfassung

Pattern oriented software architecture is a new and innovative concept which may become of paramount importance for the development of ground segment software. This paper describes how pattern oriented concepts are used within the DLR Ground Station Weilheim to develop distributed communication applications. It is essential for the software development process in Space ground stations to produce code which is efficient, reliable and easy to maintain. Developers of distributed applications have to cope with inherent and accidental complexities, such as latency, partial failure and non-portable low-level operating system application interfaces. Currently the DLR uses middleware within its ground station communication systems which was developed by CAM. The product has been used in operational state since many years and has fulfilled all existing requirements. However, for the near and mid term future some risks can be identified which make it necessary to initiate a reengineering of the existing communication middleware: Firstly it can be foreseen that the actual hardware basis will be replaced within a short / mid term period. This will result in a re-hosting of the existing applications. Secondly, the requirements on distributed applications have changed within the last years. Furthermore, there is more and more the intention to utilize COTS based software tools. Pattern oriented Software Concepts support the software development process by providing a broad spectrum of puzzle pieces, called “Patterns” to the development team. The most obvious benefits are that Patterns help avoiding to “re-invent the wheel”, they support the software development in a distributed and heterogeneous environment and they offer cost effectiveness to the software development process.