Class-Based Packet Scheduling to Improve QoS for IP Video

An important issue for video transmission over IP networks is the preservation of perceived video quality despite packet loss. Packet loss can be detrimental to compressed video. However, reducing packet loss to a very low level is difficult with current techniques. Furthermore, even a very low objective loss probability can still seriously distort perceived video quality. This paper presents a packet scheduling scheme at a router which addresses the loss issues of networked video. Experiments using real video data show that the proposed scheme can significantly improve the visual quality of video and network efficiency. Moreover, it can provide different classes of videos with different levels of loss guarantees, while maintaining service fairness among the same class of videos.