Energy-efficient concurrent media streaming over time-varying wireless networks

In this paper, we design an energy-efficient cross-layer optimization framework for media streaming over time-varying wireless network. The energy efficiency (EE) is characterized by the stochastic optimization model subject to the network stability, which is also used to depict the average media delivery delay. In harmony with the hierarchical architecture of the wireless network, the problem of stochastic optimization of media streaming is decomposed by the Lyapunov drift theory into two subproblems, associated with the flow control in transport layer and the power allocation in physical (PHY) layer. Specifically, the dynamic cross-layer control algorithm for media streaming is developed for adapting to the time-varying network state information, i.e. time-varying channel state information (CSI) of mobile terminal (MT)-access points (AP) links and dynamic queue state information (QSI) at APs. We derive a tradeoff between EE and media streaming delay, where the increase of average delay is approximately linear in V and the increase of EE is at the speed of 1/V with the control parameter V. Simulation results validate the theoretical analysis of our proposed scheme.