This paper develops a number of aspects of metadata-driven adaptation within the MPEG-21 framework that we consider are not clearly covered in the standard. Specifically, the paper introduces three complementary description tools that we have made use of and that we consider would fill certain gaps in the standard. Besides, this paper offers a group of architectural design patterns along with a...

Exploiting the outstanding performance of optical atomic clocks for improved timekeeping, relativistic geodesy, and fundamental physics beyond standard model demands comparing distant state-of-the-art clocks. Interferometric fiber links have been demonstrated as an eminent method such frequency comparisons over distances up to thousands kilometers. However, distances, attenuation mandates signa...