Video streaming over mobile is flourishing, and most commercial players use adaptive bitrate (ABR) streaming to deliver video in varying network conditions. Using network capacity and buffer occupancy as system states, ABR algorithms adjust bitrate based on the instantaneous system states, which is able to adapt to network changes in real-time and ensure high quality of experience (QoE). However, they are incapable of providing good QoE over mobile. Due to the high dynamic characteristics of cellular network, the system states change rapidly over time. The instantaneous state-based adaptation can induce significant video quality fluctuation which greatly degrades QoE. In this paper, we propose an online ABR algorithm called MSPC to provide good QoE in cellular network. To balance the conflict between rapid adaptation and smooth bitrate, MSPC utilizes the multi-step prediction of future system states to select bitrates instead of the instantaneous current states. At the same time, it controls the buffer occupancy to eliminate the impact of prediction error on performance. We implement MSPC on a reference video player with performance evaluated based on realistic cellular traces. Experimental results show that MSPC reduces the bitrate change of existing online algorithms by 62.4 percent on average while maintaining high bitrates and achieving zero rebuffering over 97.83 percent of all tested sessions.

中文翻译：

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通过蜂窝网络的多步预测提高在线比特率自适应的性能

移动视频流正在蓬勃发展，大多数商业播放器使用自适应比特率 (ABR) 流来在不同的网络条件下传输视频。ABR算法以网络容量和缓冲区占用率作为系统状态，根据系统瞬时状态调整码率，实时适应网络变化，保证高质量体验（QoE）。但是，它们无法通过移动提供良好的 QoE。由于蜂窝网络的高动态特性，系统状态随时间快速变化。基于瞬时状态的自适应会导致显着的视频质量波动，从而大大降低 QoE。在本文中，我们提出了一种称为 MSPC 的在线 ABR 算法，以在蜂窝网络中提供良好的 QoE。为了平衡快速适应和平滑码率之间的冲突，MSPC 利用未来系统状态的多步预测来选择比特率而不是瞬时当前状态。同时控制缓冲区占用，消除预测误差对性能的影响。我们在参考视频播放器上实施 MSPC，其性能基于真实的蜂窝轨迹进行评估。实验结果表明，MSPC 将现有在线算法的比特率变化平均降低 62.4%，同时保持高比特率并在所有测试会话的 97.83% 上实现零重新缓冲。我们在参考视频播放器上实施 MSPC，其性能基于真实的蜂窝轨迹进行评估。实验结果表明，MSPC 将现有在线算法的比特率变化平均降低 62.4%，同时保持高比特率并在所有测试会话的 97.83% 上实现零重新缓冲。我们在参考视频播放器上实施 MSPC，其性能基于真实的蜂窝轨迹进行评估。实验结果表明，MSPC 将现有在线算法的比特率变化平均降低 62.4%，同时保持高比特率并在所有测试会话的 97.83% 上实现零重新缓冲。