A Formal Description Technique Supporting Expression of Quality of Service and Media Synchronisation

Formal description techniques have been applied successfully to the fields of communications and distributed systems. We argue, however, that the recent emergence of multimedia computing will have a significant impact on this work. In particular, existing formal description techniques do not satisfactorily model the real-time behaviour exhibited by distributed multimedia systems. This paper considers the impact of multimedia on formal description techniques and proposes an approach in which functional behaviour is expressed in the language LOTOS and non-functional quality of service is expressed in a real-time temporal logic. This dual language approach to formal description is demonstrated through a number of multimedia examples, culminating in the specification of a lip-synchronisation algorithm.