A specification architecture for multimedia systems in Open Distributed Processing

Abstract

The field of distributed systems is now entering a stage of maturity with work focusing on standards for Open Distributed Processing (ODP). However, it is still important that standardisation remains responsive to new technological demands such as the emergence of distributed multimedia computing. This paper focuses on the likely impact of multimedia computing on formal description within ODP. In particular, a specification architecture is proposed for the formal specification and verification of quality of service and more general real-time concerns in distributed multimedia systems. This specification architecture exhibits a separation of concerns between the specification of behaviour and requirements and also between the specification of abstract behaviour and real-time concerns. The architecture also supports refinement to the computational language defined by the ODP standard. It is important to stress that the architecture does not prescribe the use of specific formal notations or languages; particular specification disciplines can however be developed by populating the architecture with appropriate languages. The usefulness of this architecture is demonstrated by the development of such an approach based on LOTOS together with a real-time temporal logic, QTL. This is applied to a simple multimedia example.