The scope of the present document is to describe the framework and architecture used by subsequent parts of this multipart deliverable that allow for new user experiences through companion devices to be provided to the full set of DVB services. As such@ the present document is abstracted from any one delivery mechanism for a DVB service. Where appropriate@ subsequent parts of this multi-part deliverable will define the interaction with a given delivery mechanism for a DVB service. The purpose of the present document is to provide an understanding of the approach taken to support these new user experiences and the setting within which the interfaces have been designed. This represents non-normative background information which assists in the understanding of the subsequent parts of this multi-part deliverable. Therefore@ the present document describes concepts@ functional roles@ overall architecture and the main interfaces defined by this multi-part deliverable that support these new user experiences. The present document does not define these interfaces@ but informatively describes them@ their relationship and their role in the overall architecture. There are various aspects that are out of scope of this multi-part deliverable. Of most relevance are: the mechanisms by which content is delivered@ and the role of a third-party companion screen application provider.