Semantic interoperability in sensor applications - making sense of sensor data

Much effort has been spent on the optimization of sensor networks, mainly concerning their performance and power efficiency. Furthermore, open communication protocols for the exchange of sensor data have been developed and widely adopted, making sensor data widely available for software applications. However, less attention has been given to the interoperability of sensor networks and sensor network applications at a semantic level. This hinders the reuse of sensor networks in different applications and the evolution of existing sensor networks and their applications. The main contribution of this paper is an ontology-based approach and architecture to address this problem. We developed an ontology that covers concepts regarding examinations as well as measurements, including the circumstances in which the examination and measurement have been performed. The underlying architecture secures a loose coupling at the semantic level to facilitate reuse and evolution. The ontology has the potential of supporting not only correct interpretation of sensor data, but also ensuring its appropriate use in accordance with the purpose of a given sensor network application. The ontology has been specialized and applied in a remote patient monitoring example, demonstrating the aforementioned potential in the e-health domain.