In the last years, a variety of concepts for user-centered systems have gained momentum. The vision of I-centric Communications and the according reference model are good examples for this development. This reference model represents a first approach of human-centered telecommunication systems, which is based on service adaptation, service integration, and IP-based reachability. The integrated adaptability feature enables the pervasive availability of services. Ambient-awareness and personalization complete this fundamental characteristic of I-centric Services. This paper elaborates the main features of the references model for I-centric Communications including business models, ambient awareness, and personalization to show the their relevance for the realization of Pervasive Communication systems.