A context-aware search system for Internet of Things based on hierarchical context model

In recent years, numerous sensing devices and wireless networks are immersed into our living environments, creating the Internet of Things (IoT) integrating the cyber and physical objects. Searching for objects in IoT is a challenging problem because the context relationships among IoT objects are various and complex. The traditional web search approaches cannot work well in the IoT search domain because they miss the critical characteristics of the context relationships. In addition, a user’s dynamic and changing context affects the user’s information needs, and an IoT search system should exploit context relationship in IoT for retrieving relevant information suitable for the user’s current context. In this paper, we present a context-aware search system for IoT, which aims to search objects and related information with more suitable results. We construct a hierarchical contextmodel based on ontology to represent the IoT objects and their contextual relationships. Then, searches are executed with consideration of users’ context that is recognized by a context-aware hiddenMarkov model. Experimental results confirmed that users could obtain more suitable and reasonable search results than with a typical web or map search system.