Context-awareness: Connecting computing with its environment

In the era of pervasive and ubiquituous computing, the scope of computer applications is no longer restricted to traditional data processing. Pervasiveness and ubiquity imply that environment is a significant factor in computation. Context is an abstraction of environmental elements that has influence in defining the behavior of an application. Context-aware computing has been developing rapidly in these days, particularly in the aspects of contexts promotion and applications. This paper describes context-aware computing and its applications at three different layers: conceptual, implementation, and application. Context is modeled as a measurable and representable entity. Context-awareness is built on top of a reactive mechanism, which guides the implementation using development tools that have the capability of working with events and asynchronous execution. A generic perspective for examining application of context-awareness is also presented.