A graphical representation for the formal description technique Estelle

Includes bibliographical references.This dissertation concerns the specification and description of complex communicating systems using Formal Description Techniques. Specifically, we propose a standard graphical representation for the Formal Description Technique Estelle and present a prototype editor based on this representation. Together they integrate the new graphical representation with existing Estelle textual tools to create a powerful graphical design technique for Estelle. The perennial popularity of graphical techniques, combined with recent advances in computer graphics hardware and software which enable their effective application in a computing environment, provide a double impetus for the development of a graphical representation for Estelle. Most importantly, a graphical technique is more easily read and understood by humans, and can better describe the complex structure and inter-relationships of components of concurrent communicating systems. Modern graphical technology also presents a number of opportunities, separate from the specification method, such as hyperlinking, multiple windows and hiding of detail, which enrich the graphical technique. The prototype editor makes use of these opportunities to provide the protocol engineer with an advanced interface which actively supports the protocol design process to improve the quality of design. The editor also implements translations between the graphical representation and the standard Estelle textual representation, on the one hand allowing the graphical interpretation to be applied to existing textual specifications, and on the other, the application of existing text-based processing tools to a graphical specification description

A Graphical Representation And Prototype Editor For The Formal Description Technique Estelle

: This paper presents a graphical representation for the Formal Description Technique Estelle, which has up until now been restricted to a textual syntax based on the general programming language Pascal. The graphical syntax and semantics of the representation are fully descriptive of a general Estelle system and complies with the ISO Estelle standard [ISO97]. This representation aims to become a standard technique for formally specifying and simultaneously documenting concurrent, communicating systems. Conventions introduced in existing graphical Estelle tools are re-used, as are graphical concepts which have become familiar through widespread use of the similar Specification and Description Language (SDL). In addition, we present a syntax-directed editor based on the graphical syntax. The editor enables practical application of the graphical technique, by translating a graphical description to the equivalent textual form which can be input into existing Estelle tools. T..