This is a common layer on top of a SOA-based middleware
architecture. It provides the functionalities for the
composition of single services offered by networked objects
to build specific applications. On this layer there is
no notion of devices and the only visible assets are services.
An important insight into the service landscape is
to have a repository of all currently connected service instances,
which are executed in run-time to build composed
services. The logic behind the creation and the management
of complex services, can be expressed in terms of