The Versatile Digital Item

Abstract

This chapter provides the definition of the Versatile Digital Item, the basic unit for data distribution used within the CONVERGENCE system. It explains how the VDI builds on, and extends the scope, of the MPEG-21 Digital Item to build a self-contained data package that can be used to encapsulate any kind of digital information in an information-centric, publish-subscribe framework. This chapter details some of the most relevant aspects pertaining to the structure of the VDI, its identification, its connection into sequences, and its logical interweaving into a fabric of inter-VDI relationships. It also explores some implications of the above aspects on the system’s operations.