“…There is therefore a need for developing a variant of a standard FDT, say Estelle, to address its limitations for uses in multimedia system development. We call this variant, Time-Estelle [1] which is able to express multimedia Quality of Service (QoS) parameters, synchronisation scenarios, and time-dependent and probabilistic behaviours for performance analysis of multimedia protocols. Time-Estelle includes the following additional features and concepts: time point, module life time, clock, firing interval, temporal operators, timed transition, polling operators and time probabilistic operations.…”