Event Reporting Scenarios and Implementations in Distributed Multimedia Systems

Distributed multimedia systems require the possibility of tracking any operation occurred in the system, such as those performed by content creators, distributors and final users. These operations may involve not only the consumption of content at the end user side, but also some system operations, such as the issuance of licenses that grant permissions over the content. The collection and storage of reporting messages generated by the different actors of the multimedia value chain, or even by the system itself, can be used for tracking, statistics and even accounting purposes. MPEG-21 has defined a standard way to express the information that needs to be conveyed in these circumstances. In this paper we will analyse the suitability of MPEG-21 event reporting, while reasoning the improvements we have proposed in order to deal with integrity, privacy, non-repudiation and the distributed generation of the reported information. We will also describe different approaches for its implementation, focusing on a new feature such as the inheritance of event report requests in a content creation and distribution environment.