Perceptual Quality in P2P Multi-Source Video Streaming Policies

This paper explores a key aspect of the problem of sending real-time video over the Internet using a P2P architecture. The main difficulty with such a system is the high dynamics of the P2P topology, because of the frequent moves of the nodes leaving and entering the network. We consider a multi-source approach where the stream is decomposed into several flows sent by different peers to each client. Using the recently proposed PSQA technology for evaluating automatically and accurately the perceived quality at the client side, the paper focuses on the consequences of the way the stream is decomposed on the resulting quality. Our main contribution is to provide a global methodology that can be used to design such a system, illustrated by looking at three extreme cases. Our approach allows to do the design by addressing the ultimate target, the perceived quality (or Quality of Experience), instead of the standard but indirect metrics such as loss rates, delays, reliability, etc. We also propose an improved version of PSQA obtained by considering the video sequences at frame-level, instead of the packet-level approach of previous works.