de Morais Wladimir Gonçalves, Santos Carlos Eduardo Maffini, Pedroso Carlos Marcelo
Department of Electrical Engineering, Federal University of Parana, Curitiba, Brazil.
Telecommun Syst. 2022;79(2):261-270. doi: 10.1007/s11235-021-00848-0. Epub 2021 Nov 24.
Video streaming currently dominates global Internet traffic. Live streaming broadcasts events in real-time, with very different characteristics compared to video-on-demand (VoD), being more sensitive to variations in delay, jitter, and packet loss. The use of adaptive streaming techniques over HTTP is massively deployed on the Internet, adapting the video quality to instantaneous condition of the network. Dynamic Adaptive Streaming over HTTP (DASH) is the most popular adaptive streaming technology. In DASH, the client probes the network quality and adjusts the quality of requested video segment according to the bandwidth fluctuations. Therefore, DASH is an over-the-top application using unmanaged networks to distribute content in the best possible quality. In order to maintain a seamless playback, VoD applications commonly use a large reception buffer. However, in live streaming, the use of large buffers is not allowed because of the induced delay. Active Queue Management (AQM) arises as an alternative to control the congestion in router's queue, pressing the traffic sources to reduce their transmission rate when it detects incipient congestion. In this article, we evaluate the performance of recent AQM strategies for real-time adaptive video streaming. Furthermore, we propose a new AQM algorithm to improve the user-perceived video quality. The results show that the proposed method achieves better performance than competing AQM algorithms and improves the video quality in terms of average peak signal-to-noise ratio while keeping the fairness among concurrent flows.
视频流目前在全球互联网流量中占据主导地位。直播实时广播事件，与视频点播（VoD）相比具有非常不同的特性，对延迟、抖动和丢包的变化更为敏感。基于HTTP的自适应流技术在互联网上得到了大规模应用，使视频质量能够适应网络的即时状况。HTTP动态自适应流（DASH）是最流行的自适应流技术。在DASH中，客户端探测网络质量，并根据带宽波动调整所请求视频片段的质量。因此，DASH是一种利用非托管网络以尽可能最佳质量分发内容的超顶应用程序。为了保持无缝播放，VoD应用程序通常使用一个大型接收缓冲区。然而，在直播中，由于引入的延迟，不允许使用大型缓冲区。主动队列管理（AQM）作为一种控制路由器队列拥塞的替代方法出现，当检测到初期拥塞时，促使流量源降低其传输速率。在本文中，我们评估了用于实时自适应视频流的近期AQM策略的性能。此外，我们提出了一种新的AQM算法以提高用户感知的视频质量。结果表明，所提出的方法比竞争的AQM算法具有更好的性能，并且在保持并发流之间公平性的同时，在平均峰值信噪比方面提高了视频质量。
