NMSPA: A Non-Markovian Model for Stochastic Processes.
Natalia López, Manuel A. Nunez · 2000
In this paper we introduce a new Stochastic Process Algebra: NMSPA. This new language presents the usual features of stochastic models but probability distributions are not restricted to be exponential. This fact increases the expressive power of the language in several ways. For example, we can specify actions that can be executed with probability 1 in a finite amount of time, so-called passive actions fall in a natural way inside our framework, urgency of internal actions can be expressed, etc. In order to define an interleaving semantics for the parallel operator, we benefit from ideas used in timed process algebras. Our operational transitions include information about the time when actions can be executed, as well as the random variable associated with them. We provide our language with a notion of strong bisimulation which takes into account urgency of internal transitions. Finally, we specify the Alternating Bit Protocol. This is a very simple communication protocol where th...