This paper deals with a context awareness system based on a service-oriented architecture dedicated to the Smart Home. In our approach, a Smart Home must be able to provide services adapted to the needs of its inhabitants. To achieve this, we propose to build a Smart environment that takes into account the ambient context of its inhabitants, providing contextually-aware services. In previous work [18], we described a four-layer architecture to manage data acquisition and context information in distributed sensor network for smart home environments. In this paper, we focus on the context model based on an OWL ontology and then on the inference layer, based on SWRL rules language. Finally, we present our current implementation.