A cross-layer design method for multiple realtime video streams in multi-hop wireless networks

In this paper, a novel cross-layer design method for realtime video traffics in CDMA multi-hop wireless networks is proposed. First, the performances of application, physical, MAC, and network layers are modelled by some classical models under reasonable assumptions. Then, we present a framework in which source coding, power control, ARQ control, and delay partitioning functionalities at different layers can be jointly optimized. Our studied problem is to maximize the video quality under strict end-to-end delay constraints through adjusting the source coding rate, end-to-end delay distribution, and each node's transmit power. This optimization problem is proved to be a nonlinear but log-convex one. Finally, we propose a centralized solution based on the geometric programming theory, as well as a partially distributed solution based on the Lagrangian dual decomposition technique. And both solutions are proved to converge to the global optimum of the above problem.