Optimization of adaptive data-flows for competing multimedia presentational database sessions

Multimedia database systems must accommodate the capability to adapt the resource demand of executing presentations. This concerns adaptations across components of presentations as well as across concurrent sessions adhering to the individual needs of content providers and viewers. This paper describes the general concept of Reactive Playout Management (RPM) which provides an application-independent service for adaptive multimedia presentations. Furthermore, it proposes the PYLOT scheme (PlaYout Load OpTimization scheme) to enable RPM in best-effort architectures. In particular the global resource allocation routine of PYLOT is elaborated which manipulates the load proportions such that minimal total adjustment costs and maximal total adjustment profit are achieved, respectively. This linear programming based optimization is demonstrated by experimental results