1. Introduction
Computing is becoming pervasive. Autonomous computer-based systems are going to be embedded in all our everyday objects and in our physical environment, and they are going to interact with each other in a globally connected network, possibly making use of wireless communication technologies [4], [15]. In such a scenario, mobility too, in different forms, will be pervasive [1]. Mobile users, mobile devices, transportable computer-based objects, as well as mobile software components, define an open and dynamic networked world, in which the topology of interactions change with time. As a consequence, the effects of computation and coordination activities are likely to dramatically change depending on the location, i.e., the context, in which they occur.