Telecommunication service description using state transition rules

Abstract

For telecommunication software design, SDL[1,2] (Functional Specification Description Language) is conventionally used for specification descriptions. This article first clarifies difficulties of SDL description for supplementary services[3] which allow a conversation among an infinite number of customers, and where there is considerable service interaction behavior.Then, this article proposes a new telecommunication service description method, STR (State Transition Rule) method. In the proposed method, the service among an arbitrary number of customers can be defined easily, and declarative description is allowed for service interaction behavior in the early stage of software design. Also, this article clarifies a feature of the proposed descriptions, that monotonic increase of transition rules realizes easy service addition. Lastly, the analyzability of the proposed descriptions is discussed.