Abstract :
A description language for specifying a wide range of different protocols in a formal manner is presented and its usage in the Pan-European digital mobile radio communication system is shown. This language, FAN.1 (Frame Analyzing Notation One), can be seen as an extension of this CCITT defined specification language ASN.1 (Abstract Syntax Notation One), and enables the user to specify protocol data units on a bit precise level. Such formally specified interfaces are an aid to the software development phase and ease the insertion of updates into a given interface. Also these specifications contribute a great deal to the various testing phases of the software system
