Rebuffering but not Suffering: Exploring Continuous-Time Quantitative QoE by User's Exiting Behaviors

Quality of Experience (QoE) is one of the most important quality indicators for video streaming applications. But it is still an open question how to assess QoE value objectively and quantitatively over continuous time both for academia and industry. In this paper, we carry out an extensive data study on user behaviors in one of the largest short-video service providers. The measurement data reveals that the user’s exiting behavior in viewing video streams is an appropriate choice as a continuous-time QoE metric. Secondly, we build a quantitative QoE model to objectively assess the quality of video playback by discretizing the playback session into the Markov chain. By collecting 7 billion viewing session logs which cover users from 20 CDN providers and 40 Internet service providers, the proposed state-chain-based model of State-Exiting Ratio (SER) is validated. The experimental results show that the modeling error of SER and session duration are less than 2% and 10s respectively. By using the proposed scheme to optimize adaptive video streaming, the average session duration is improved up to 60% to baseline, and 20% to the existing black-box-like machine learning methods.