Cross-layer conditional retransmission for layered video streaming over cellular networks

In cellular networks, a wireless access network is more error-prone as compared to a wired core network, where burst channel errors often occur because of fading, interference, or lossy handovers. In order to avoid unaccepted quality degradation of video streaming over cellular networks, we propose a cross-layer conditional retransmission scheme based on layered video which is divided into several types with unequal importance by using data partitioning tools. When basic quality-of-service (QoS) guarantees have been provided at the physical layer, the proposed scheme can coordinate mapping of QoS parameters at different layers of communication protocol stack. Considering the unequal importance of different video partitions under the real-time and bandwidth constraints, the proposed scheme first uses the unequal link-layer retransmission to combat channel residual errors in a wireless access network; and then uses the end-to-end transport-layer retransmission to provide enhanced QoS support over cellular networks. The simulation results show that the proposed scheme can effectively improve the perceptual quality of cellular video streaming compared with the traditional conditional retransmission schemes.