Semantic Context-aware Service Discovery with QoS Support in Opportunistic Mobile Networks

Abstract

Recent technological advancements in mobile devices are enabling the vision of opportunistic networking paradigm to become a reality. As an extension of opportunistic communication paradigm, opportunistic computing and services research leverages the powerful capabilities and pervasive nature of modern smartphones to provision services to nearby nodes. When an opportunistic network is viewed as a collection of service providers and service consumers rather than as a simple message routing system, node and service discovery come to play a critical role. Current service-discovery protocols do not make use of contextual information in discovering services, and as a result, fail to provide the most appropriate and relevant services for users. In addition, current protocols rely on keyword-based search techniques and do not consider the semantic description of services. Thus, they suffer from poor precision and recall. To address the need for a discovery architecture that supports the envisioned scenarios of opportunistic computing, we propose a context-aware service-discovery protocol that exploits meaningful contextual information, either static or dynamic, to provide users with the most suitable and relevant services. The architecture relies on a shared, ontology-based, semantic representation of services and context to enhance precision and recall. It enables knowledge sharing, capability-based search, autonomous reasoning, and semantic matchmaking. Furthermore, the architecture facilitates a dynamic service-selection mechanism to filter and rank matching services, based on their dynamic contextual attributes, which further enhances the discovery process and saves users time and effort. Our empirical results indicate the effectiveness and feasibility of the proposed architecture.