A Decentralized Trustworthy Context and QoS-Aware Service Discovery Framework for the Internet of Things

The Internet of Things envisions a multitude of heterogeneous objects and interactions with physical environments. It has provided a promising opportunity to build powerful services and applications by leveraging the growing ubiquity of smart objects connected to the Internet. In this environment, it is challenging to locate desirable services due to the considerable diversity, large scale, dynamic behavior, and geographical distribution of the services provided by physical objects. In this paper, we propose a decentralized semantics-based service discovery framework, which can effectively locate trustworthy services based on requester's quality of service demands and changing context requirements. The proposed service discovery system is built upon fully distributed peer-to-peer architectures and includes two discovery approaches which are scalable, robust, and trust assured. Moreover, an efficient trust propagation mechanism is proposed, which seamlessly integrates with the proposed service discovery system without adding additional infrastructure overhead. Comprehensive simulation studies have demonstrated the effectiveness of the proposed framework.