Abstract: In this study, a new approach for deriving right and relevant context information was introduced by exposing all kinds of disparate and distributed devices as RESTful services and a variety of minuscule sensors as event-emitters. We have leveraged the concept of Device Service Bus (DSB) for capturing and translating service messages from RESTful services to the target data fusion engine and similarly used Esper, the open source event processing engine, to capture streams of event messages from sensors. All the data embodied in these messages are extracted and interpreted by the data fusion engine (a policy-oriented data interpretation and dissemination software module) in order to emerge with actionable insights. The context-awareness algorithm is formalized and presented in this study. Finally, a new mathematical model for calculating the time complexity of the context-awareness algorithm was come out.