An accurate analytical model on blocking performance of multicast three-stage networks

The fast deployment of broadband networks and the evolution of communication services has revealed the importance of a network-wide availability of multicast communications, that is from one source to multiple destinations. This paper considers three-stage switching networks able to support multicast traffic, i.e. connections in which one inlet of a node is connected to more than one outlet of the node at the same time. An analytical model is developed here that evaluates the blocking probability of multicast connections taking into account statistically the correlation between occupancy events in links belonging to different interstage patterns. Such new model proves to be more accurate than any previous model addressing the same issue. Interestingly enough, unlike other models the new formulation is consistent with the theoretical conditions of a non-blocking three-stage switching network.