State Based Analysis of Pervasive Systems

Pervasive systems require the coordination of many components within the environment. Since these components often exhibit state based behaviour, several authors have proposed state based descriptions that model their interaction as orthogonal regions within a global level statechart. The use of statecharts for this purpose is attractive as they are widely used and are incorporated within the UML. However, several authors have reported difficulties when modelling complex interdependences between orthogonal state regions. In this paper we propose a form of behavioural modelling that represents the system state in a more manageable form. We then show how this may be used to define the behaviour of individual pervasive components.