Levels of abstraction in programming device ecology workflows

We explore the notion of the workflow for specifying interactions among collections of devices (which we term device ecologies). We discuss three levels of abstraction in programming device ecologies: high-level workflow, low-level workflow and device conversations, and how control (in the sense of operations issued by an end-user on such workflows or exceptions) is passed between levels. Such levels of abstraction are important since the system should be as user friendly as possible while permitting programmability not only at high-levels of abstraction but also at low levels of detail. We also present a conceptual architecture for the device ecology workflow engine for executing and managing such workflows.