Date: December 1995
Pages: 15
In this report we give a high-level net model for a specific ``video on demand'' system. This system has some very interesting modeling features: FIFO queues, the bunching property, the parallel machine scheduling and a complicated resource allocation mechanism. The bunching property stands for feasibility of several requests being served together by one resource. The resource allocation mechanism for this video on demand system has a special refusal by choice feature which means that the resource is not necessarily allocated even though it is available. The predicate/transition net formalism has been used in the modelling and reachability analysis in studying the properties of the model. The causal model developed here allows a natural extension for the use of time or stochastic net theoretical methods for performance analysis.
Keywords: video on demand, high-level net models, FIFO with the bunching property, parallel scheduling algorithms, reachability analysis.