Semantics for Privacy and Shared Context.

Capturing, maintaining, and using context information helps mobile applications provide better services and generates data useful in specifying information sharing policies. Obtaining the full benefit of context information requires a rich and expressive representation that is grounded in shared semantic models. We summarize some of our past work on representing and using context models and briefly describe Triveni, a system for cross-device context discovery and enrichment. Triveni represents context in RDF and OWL and reasons over context models to infer additional information and detect and resolve ambiguities and inconsistencies. A unique feature, its ability to create and manage "contextual groups" of users in an environment, enables their members to share context information using wireless ad-hoc networks. Thus, it enriches the information about a user's context by creating mobile ad hoc knowledge networks.