H.264/SVC rate-resiliency tradeoff in faulty communications through 802.16e railway networks

Focusing on 802.16e-based railway networks, our work deals with the degradation of the perceived quality of multimedia communications in presence of handover events. The movement of mobile nodes (MN) across coverage areas of distinct Base Stations (BS) involves global disconnection periods, which leads to a degradation of the perceived video quality. During this period, video data packets are dropped, and therefore video frame information is lost. The study presented here concentrates on the specific dynamism characteristics of conventional video surveillance applications and the transmission of the recorded video information over 802.16e networks. We conclude, through intensive simulations, that the GOP structure of the H.264/SVC encoded video information should not exclusively emphasize on maximizing the compression rate of the stream. Instead, the utilized GOP structure should be selected according to both the motion pattern of the processed video and the handover statistics of the railway communication channel which, in turn, are extremely predictable in railway scenarios. This conclusion is corroborated by proposing the insertion of intra-period frames into the GOP structure, in order to maximize the average Peak Signal to Noise Ratio (PSNR) of the received stream at a negligible video size penalty cost.