Scalable Video Transmission with Appropriate Path Selection and Raptor Network Coding

Providing reliable and high quality video over wireless networks is extremely challenging task due to unstable wireless nature. Scalable Video Coding (SVC) is very vulnerable to channel disturbance when transmitted over error-prone wireless channels. Conventional Forward Error Correcting (FEC) codes and retransmission solutions will become less effective while streaming SVC over wireless networks for the reason that video frame errors appear in bursts rather than random and the bad channel condition usually persists for a period of time. In this paper we investigate the problem of streaming video on lossy packet networks such as Wireless Mesh Network (WMN) with path and symbol diversity. We propose a scheme with Unequal Error Protection (UEP) based on Appropriate Path Selection (APS) and Network Coding (NC). The scheme tries to select appropriate path based on Grey Relational Analysis (GRA) for different SVC layers. It chooses the best path for most important layer, base layer, and less stable paths for enhancement layers. We also implement network re-encoding algorithm based on Raptor codes in the forwarding peers in order to increase the perceived video quality at receiving end.