Matching and Mediation of Heterogeneous Context Information

With the further emergence of mobile and ubiquitous computing, also the number of context-aware applications grows. Often these applications require similar types of context information (e.g. a position or the current activity). An aggravating factor is that the number of sources for context information (e.g. sensors, reasoners, or databases) grows and the requirements on these sources and purposes for using the information are different. As a result, the level of heterogeneity of these sources and the provided information significantly increases. In this article, we present a system for matching and mediating context offers of loosely coupled context sources while taking into account the requirements of context-aware applications expressed in form of context requests. The matching and mediation process allows an autonomous establishment of mediation processes in order to transfer information from an offered representation into a requested representation and thus to overcome heterogeneous context information. [The dissertation of the first author contains a more comprehensive discussion of the subject, see (Wagner, Context as a service, Ph.D. thesis, University of Kassel, FB 16: Elektrotechnik/Informatik, Distributed Systems Group, 2013.)]