Middleware Support for Context-awareness in Asynchronous Pervasive Computing Environments

Context-awareness is an essential feature of pervasive applications, and runtime detection of contextual properties is one of the primary approaches to enabling context awareness. However, existing context-aware middleware does not provide sufficient support for detection of contextual properties in asynchronous environments. We argue that in asynchronous environments, the concept of time needs to be reexamined. Instead of assuming the availability of global time or synchronous interaction, we should rely on logical time. To this end, we present the Middleware Infrastructure for Predicate detection in Asynchronous environments (MIPA), which supports context-awareness based on logical time. Design and operation of MIPA are explained in detail. We also evaluate MIPA with a comprehensive case study. The evaluation results show the cost-effectiveness and scalability of MIPA.