Service Discovery and Composition in Body Area Networks

In pervasive environments, Body Area Networks (BANs) are characterized by the mobility of their users. BANs can con- tinuously interact with each other, thus enabling the pro- vision of new applications and services at runtime. New complex services can be provided by composing simpler ser- vices available on neighbouring network nodes. However, since the topology of BANs is continuously changing due to users’ movements, it is unfeasible to specify a-priori all pos- sible configurations under which a given complex service can be composed. In order to address this issue, we introduce a two–layered service discovery and composition architecture, that proactively notifies a distributed service directory with changes in service availability. In order to cope with the net- work mobility and intermittent connectivity, our approach is to cluster nodes in the sensor network based on their con- nectivity patterns. We use a multi–agent state machine to recognize the availability of complex services and to provide them. Our solution is validated by a prototype implementa- tion of our architecture, by the study of the statistical model of complex services, and by experimental evaluations.