Jeffrey Heer, Alan Newberger, Chris Beckmann, and Jason Hong


International Conference on Ubiquitous Computing (Ubicomp)


January 2003


As low-level architectural support for context-aware comput-ing matures, we are ready to explore more general and powerful means of accessing context data. Information required by a context-aware appli-cation may be partitioned by any number of physical, organizational, or privacy boundaries. This suggests the need for mechanisms by which ap-plications can issue context-sensitive queries without having to explicitly manage the complex storage layout and access policies of the underlying data. To address this need, we have developedliquid, a prototype query service that supports distributed, continuous query processing of context data. This paper articulates the current need for such systems, describes the design of theliquid system, and presents both a room-awareness application and notification service demonstrating its functionality.

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