Supporting Generalized Context Interactions

Context-awareness refers to a computing model where ap-plication behavior is driven by a continually-changing environment. Mobile computing poses unique challenges to context-sensitive applications and middleware, including the ability to run on resource-poor devices like PDAs and the necessity to limit assumptions about the underlying network. Though middleware exists to provide context-awareness to applications, they have not been designed with the limitations inherent in dynamic mobile environments in mind. This paper discusses a lightweight approach to context-sensitivity that takes into account these considera-tions. We explore the use of modularization to tailor service discovery policies for specific applications, as well as leveraging existing language constructs for simplifying the creation and aggregation of different con-text types. We also discuss a Java implementation of these concepts, along with three sample applications that can automatically propagate changes in context to clients running on devices varying from mobile phones to desktop computers