Providing Contextual Information to Ubiquitous Computing Applications

Ubiquitous computing applications are increasingly leveraging contextual information from several sources to provide users with behavior appropriate to the environment in which they reside. If these sources of contextual information are used and deployed in an ad hoc manner, however, they may provide overlapping functionality, fail to provide needed functionality, and require the use of inconsistent interfaces by applications. To overcome these problems, we introduce a concise organization of services and a single service interface that provide applications with contextual information in a unified manner. We show, via example applications and services that we have implemented, how our service organization and interface can be used to allow proactive applications to adapt their behavior to match a users current environment.