Controlled Disclosure of Context Information across Ubiquitous Computing Domains

One of the challenges in ubiquitous computing is that of mobility, which typically requires interaction between intelligent environments in different domains of administration. We present a highly distributed and collaborative system that enables context-aware applications to obtain context information about mobile entities (users or devices) independent of the domain that produces this information. The added value of the system is that it enriches the amount of available context information about these entities in a way that is transparent for applications. In addition, the system shares context information across domains in a controlled manner by taking privacy policies into account, both of the mobile entity as well as of the domains it visits. We discuss the system's architecture, its implementation, and the way we deployed it.