Stream-Based Specification of Mobile Systems

Abstract.

This paper presents a formal specification technique for mobile systems based on input/output relations on streams. We consider networks of components communicating asynchronously via unbounded directed channels. Mobility is achieved by allowing the components to communicate channel ports. We distinguish between many-to-many and two variants of point-to-point communication. The communication paradigms are semantically underpinned by denotational models. The models are formulated in the context of timed non-deterministic data ow networks and presented in a stepwise fashion. The emphasis is on capturing the special kind of dynamic hiding characterising mobile systems. We demonstrate the proposed approach in a number of small examples.