Dependent optimal stopping framework for wireless multimedia transmission

In this paper, we formulate the cross-layer optimization for delaysensitive media transmission over time-varying wireless channels as a finite-horizon Markov decision process (MDP) by explicitly considering the users´ heterogeneous multimedia traffic characteristics (e.g. delay deadlines, distortion impacts and dependencies etc.) and time-varying network conditions. Based on the heterogeneous characteristics of the media packets, we are able to express the transmission priorities between packets as a new type of directed acyclic graph (DAG). This DAG provides the necessary structure for determining the optimal cross-layer actions in each time slot. The simulation results demonstrate that the proposed solution significantly outperforms existing state-of-theart cross-layer solutions.