The Flexible Dual TCP-UDP Streaming Protocol (FDSP) combines the reliability of TCP with the low latency of UDP, thus providing transport layer improvements towards maintaining high QoE of multi-bitrate videos in adaptive streaming. FDSP delivers the more critical parts of the video data via TCP and the rest via UDP. FDSP also uses Bitstream Prioritization (BP), a sliding scale that determines the proportion of video data that is sent using TCP. BP can be adjusted according to the level of network congestion. FDSP-based streaming reduces total rebuffering time by over 90%, and rebuffering instances by 50% in many cases compared to TCP-based streaming. At the same time, packet loss reduces by over 75% for most BP levels compared to UDP-based streaming. In addition, FDSP-based streaming is potentially more suitable for adaptive streaming compared to the state-of-the-art TCP-based HTTP Adaptive Streaming (HAS), which is often plagued by high latency and high bandwidth requirements. In contrast, FDSP requires significantly less bandwidth than TCP in congested networks while exhibiting more stable client buffers.

中文翻译：

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使用灵活的双 TCP-UDP 流协议改进自适应高清视频流 QoE 的实验研究

灵活的双 TCP-UDP 流协议 (FDSP) 将 TCP 的可靠性与 UDP 的低延迟相结合，从而为在自适应流中保持多比特率视频的高 QoE 提供传输层改进。FDSP 通过 TCP 传输视频数据中更关键的部分，通过 UDP 传输其余部分。FDSP 还使用比特流优先级 (BP)，这是一种确定使用 TCP 发送的视频数据比例的滑动比例。BP可以根据网络拥塞程度进行调整。与基于 TCP 的流相比，基于 FDSP 的流将总重新缓冲时间减少了 90% 以上，在许多情况下将重新缓冲实例减少了 50%。同时，与基于 UDP 的流媒体相比，大多数 BP 级别的数据包丢失减少了 75% 以上。此外，与最先进的基于 TCP 的 HTTP 自适应流媒体 (HAS) 相比，基于 FDSP 的流媒体可能更适合自适应流媒体，后者通常受到高延迟和高带宽要求的困扰。相比之下，在拥塞的网络中，FDSP 需要比 TCP 少得多的带宽，同时表现出更稳定的客户端缓冲区。