Date Added: Aug 2010
In this paper, the authors propose a systematic solution to the problem of scheduling delay-sensitive media data for transmission over time-varying wireless channels. They first formulate the dynamic scheduling problem as a Markov Decision Process (MDP) that explicitly considers the users' heterogeneous multimedia data characteristics (e.g. delay deadlines, distortion impacts and dependencies etc.) and time-varying channel conditions, which are not simultaneously considered in state-of-the-art packet scheduling algorithms. This formulation allows one to perform foresighted decisions to schedule multiple data units for transmission at each time in order to optimize the long-term utilities of the multimedia applications. The heterogeneity of the media data enables one to express the transmission priorities between the different data units as a priority graph, which is a Directed Acyclic Graph (DAG).