Semantic Handover for Seamless Service Continuity within User Ambient Context

In a user-centric approach, the user wants to have a unique and continuous service session that best answers his ambient context. Spatial mobility is one of the factors that cause modifications in this ambient context and consequently influence the user's service session. On the network layers, many solutions have been conceived to overcome this challenge. However, this problem is not yet investigated on the service layer. For this purpose, we propose in this paper the concept of semantic handover. This concept acts on the service layer by analogy to the network's handover mechanisms. It is based on three complementary roles: the initiator, that detects a variation in user's ambient context caused by spatial mobility and that initiates the semantic handover, the decider, that decides which services should be replaced in user's service session and what are their ubiquitous counterparts, and the executor, that executes the decision and adapts user's service session to the new ambient context. By using this novel concept, we guarantee a seamless continuous service session for the end-user throughout his spatial mobility and ambient context. User's functional and non-functional (QoS criteria) preferences are also taken into account through the usage of the ubiquity approach in this service session adaptation.