Description
A typical real-time system, the Telephone Switching System (TSS), is a highly complicated system in design and implementation. This paper presents the formal design, specification, and modeling of the TSS system using a denotational mathematics known as Real-Time Process Algebra (RTPA). The conceptual model of the TSS system is introduced as the initial requirements for the system. Then, the architectural model of the TSS system is created using the RTPA architectural modeling methodologies and refined by a set of Unified Data Models (UDMs). The static behaviors of the TSS system are specified and refined by a set of Unified Process Models (UPMs) such as call processing and support processes. The dynamic behaviors of the TSS system are specified and refined by process priority allocation, process deployment, and process dispatching models. Based on the formal design models of the TSS system, code can be automatically generated using the RTPA Code Generator (RTPA-CG), or be seamlessly transformed into programs by programmers. The formal model of TSS may not only serve as a formal design paradigm of real-time software systems, but also a test bench of the expressive power and modeling capability of exiting formal methods in software engineering.