Conceptual modeling of mobile object systems: language constructs for distinguishing between mobile and stationary subsystems

A couple of specification and modeling languages dedicated to the particularities of mobile systems have been developed as mobile hardware and software gain wide acceptance. Though these languages facilitate describing systems of mobile objects at different levels of abstraction, they do not allow to distinguish between the ever-mobile units and those which provide the fixed subsystems as the context for the mobile entities. However, as this is an essential distinction for many scenarios, in this article we present some suitable constructs as an extension of an already existing specification language from the area of information retrieval.