Context Aware Framework – A Middleware for Ubiquitous Computing

Context Aware Computing enables the applications or systems to provide relevant services and information to users, based on the information collected from various entities involved in the environment. It also provides the ability for the systems to acquire and do reasoning on the situational context. In this paper we discuss about various research challenges for building context aware system context data acquisition, context interpretation, context data modeling, context reasoning and adapting applications according to context. In a dynamic environment, one of the challenges in building context aware applications is the communication paradigm between context providers and end applications. Synchronous communication may not be suitable since all the entities may not be live all the time. In this paper we present the architecture of a Context Aware Framework developed using publish / subscribe paradigm to provide asynchronous communication between sensor layer which provides the context information and application layer which consumes the context in order to act according to the context. We also present how Context Aware Framework has been used for rapid development of context aware applications across various domains. The framework maintains a knowledge base to store context information in OWL (Web Ontology Language) format and does context interpretation, context modeling, rule based reasoning and event notification.