MODELING BUFFER ADMISSION MECHANISMS USING STOCHASTIC AUTOMATA NETWORKS

The stochastic automata networks formalism is an attractive technique to model complex systems with interacting components. Each component o f the system is modelled by a single automaton; interactions between c omponents are modelled by labels on the arcs which may represent synch ronization and state-dependent transitions. Every automaton is associa ted with some matrices which allow to build the transition matrix of t he underlying Markov chain, using tensor algebra. To illustrate this m ethodology, we introduce two buffer policies which could be used in AT M switching node. Every policy manages two priority levels which have distinct cell loss requirements. The first buffer policy is based on t he push-out mechanism : a high priority cell replaces a low priority c ell when the buffer is full. The second policy causes the discarding o f all the low priority cells when the user transmits a request to send a burst of cells. In both studies, we compute the loss probabilities of each type of cells under various assumptions.