Telecommunications service requirements: Principles for managing complexity

Telecommunications services are complex and rapidly becoming more so. If we wish to apply formal methods of requirements engineering in the telecommunications domain, then the primary obstacle we face is the sheer complexity of the behaviour to be described. This paper focuses on one kind of telecommunications system, thelong-distance telephone network (LDTN), and presents several ways of managing complexity in LDTN requirements. The alleviation of complexity comes from careful application of some general principles of requirements engineering. At the same time that these principles help us manage complexity, the productive focus on complexity enhances the motivation for these principles.