The role of the formal methods in the telecommunication software development

Harmatné Medve Anna <medve@almos.vein.hu>

Veszprémi Egyetem Információs Rendszerek Tanszék

Tarnay Katalin Dr. <tarnayk@almos.vein.hu>

Veszprémi Egyetem Információs Rendszerek Tanszék

In this article we will demonstrate the application of modern methods in the telecommunication software development. The first stage of design is defining the requirements and specifications in text format, followed by formal specifications. The formal specification defines the system in general as communicating finite-state machines. Its language is SDL (Specification and Description Language). The message exchange among the system components can be characterized by time sequence diagram, its language is MSC (Message Sequence Chart). Test suits of the conformance test are derived from the formal specification. We specify the set of tests with TTCN (Tree and Tabular Combined Notation). Data revealed during the survey is given in ASN.1., which could be incorporated into SDL and TTNC specifications. Design is followed by the implementation phase, these days mainly C++ or Java is used for programming. The completed system is tested on two levels. First basic software tests re conducted, followed by the conformance test, when the implemented system is compared to the formal specification.

The application of the formal methods reduces the life-cycle of the system, makes implementation more reliable and makes more unambiguous the relation between specific elements of the system. The application of these methods enables automation of system implementation.

There are CASE tools available for generating automatically the final product from validated and tested SDL specifications