  Recently, multi-screen cloud social TV is invented to transform TV into
social experience. People watching the same content on social TV may come from
different locations, while freely interact with each other through text, image,
audio and video. This crucial virtual living-room experience adds social
aspects into existing performance metrics. In this paper, we parse social TV
user experience into three elements (i.e., inter-user delay, video quality of
experience (QoE), and resource efficiency), and provide a joint analytical
framework to enhance user experience. Specifically, we propose a cloud-based
optimal playback rate allocation scheme to maximize the overall QoE while upper
bounding inter-user delay. Experiment results show that our algorithm achieves
near-optimal tradeoff between inter-user delay and video quality, and
demonstrates resilient performance even under very fast wireless channel
fading.
