An Extended Context Model in a RFID-Based Context-Aware Service System

Context-aware computing is an important area of ubiquitous computing. To study context-aware computing, the first step is to define its main component: context. We survey the various context definitions and then adopt the definition of Deypsilas. We survey the context modeling techniques and point out the deficiencies of each technique. The purpose of this paper is to propose a formal context model. We extend the OWL-S from both the user-centric view and service-centric view. At the same time, the extended model can deal with service conflict problem in the ubiquitous environment. At last, we provide a general system structure to fulfill context aware service based on our RFID middleware. In this system, our context model is used for service match and service composition.