Cross-layer transmission for video streaming in wireless relay networks

In this paper, a novel cross-layer optimization scheme for video streaming in wireless relay networks is proposed. It takes into account of delay constraints at the application (APP) layer, relay node selection at the MAC layer and dynamic fading of wireless channels at the physical (PHY) layer in an integrated mode to improve the quality of video transmission. At the PHY layer, a finite state Markov channels (FSMC) model is used to estimate the channel states and a modified RTS/CTS scheme is proposed to facilitate the path selection at the MAC layer. The impacts of delay constraints and other factors at the APP layer are investigated. At the MAC layer, the source node can choose the proper path to transmit video data while considering video delay requirements and wireless channel states simultaneously. A typical three-node uploading scenario in video surveillance applications is considered as an example for performance evaluation. The experimental results show that the proposed scheme could improve video transmission quality and achieve a near-optimal performance.