Modelling MAC-Layer Communications in Wireless Systems

We present a timed process calculus for modelling wireless networks in which individualstations broadcast and receive messages; moreover the broadcasts are subject to collisions. Basedon a reduction semantics for the calculus we define a contextual equivalence to compare the externalbehaviour of such wireless networks. Further, we construct an extensional LTS (labelled transitionsystem) which models the activities of stations that can be directly observed by the external environ-ment. Standard bisimulations in this LTS provide a sound proof method for proving systems contex-tually equivalence. We illustrate the usefulness of the proof methodology by a series of examples.Finally we show that this proof method is also complete, for a large class of systems.