Distributed Context Models in Support of Ubiquitous Mobile Awareness Services

Real-time context aware applications require dynamic support reflecting the continual changes in context. Architectures that distribute and utilize the supporting sensor information within the constraints of publish-subscribe systems provide sensor information in primitive forms requiring extensive application-level transformations limiting the dynamic addition and removal of sources. Elevating sensors to first class objects in a meta-model addresses these issues by applying ontological dimensions in direct support of context. This paper proposes an extension of such a model into a distributed architecture co-located with context user agents. This arrangement provides clients with a model schema which is continually evolving over sensor domains. In addition, the evolving model schema represents an accurate temporal view of a userâĂŹs context with respect to the available sensors and actuators.