SDL 92 is the recognized international standard language for designing and specifying telecommunications systems, and is increasingly also used for RAD, real-time, interactive applications. This is the first complete introduction and reference to SDL for both novices and experienced system engineers.The book begins with an overview of basic SDL concepts, structure and syntax. It introduces SDL abstract data types, the SDL interpretation model, and shows how to specify protocols with SDL.All professional systems engineers, programmers and students of system development working in telecommunications, real-time, interactive and distributed systems.