Context Management and Reasoning about Situations in Pervasive Computing

ions and context dissemination Early context middleware perceived the tasks of disseminating contextual information and providing appropriate abstractions for programmers to deal with that information as primary goals of a context infrastructure. The Context Toolkit The Context Toolkit [DE00] builds a framework for interfacing with devices and software entities which provide contextual information. A set of abstractions, namely, context widgets, context interpreters and context aggregators can be used by application developers to prototype new context-aware applications. Widgets abstract sensory originated information and make that information available to applications. Widgets can be considered proxies to devices by mediating and encapsulating all communication between applications and real devices. Interpreters abstract the activity of recognizing context. Given information represented with widgets, interpreters are used as abstractions for reasoning about that information. Such activity is ultimately delegated to the specific application, which should provide explicit functionality to achieve appropriate reasoning. Aggregators collect contextual information from widgets and interpreters to represent the complete context of an entity.□