A Progressive Download Method Using Multiple TCP Flows on Multiple Paths
A Progressive Download Method Using Multiple TCP Flows on Multiple Paths
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一种在多路径上使用多个TCP流的渐进式下载方法
DOI：
10.1109/bwcca.2015.62
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Tokumasa Hiraoka and Junichi Funasaka
中科院分区：
文献类型：
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作者：
Daichi Koide;Mayu Yamanaka;Daisuke Tanaka;Takuya Itahashi;Akira Yamawaki;Tokumasa Hiraoka and Junichi Funasaka
如今，许多高性能网络链路（包括无线网络链路）已可同时访问互联网。 TCP无法充分利用这种高延迟、高丢包率的网络链路的带宽，因此使用渐进式下载方法的视频播放服务的质量有时会恶化。为了解决这一问题，一些研究提出了在多条路径中的每一条上使用一个TCP流或者在一条路径上使用多个TCP流的文件传送方法。然而，尚未研究将这两者结合起来的有前景的方法。在本文中，我们提出了一种在多条路径的每条路径上使用多个并发 TCP 流的渐进式下载方法。在我们的提案中，提出了一些公式，用于根据渐进式下载过程开始时每条路径上的网络状况静态估计所需的 TCP 流数量。此外，还设计了一种块分配方法来减轻乱序块到达的影响，该方法包括对分配给较慢路径的块编号施加一些偏移，并重复请求已请求的块，但会阻止渐进式下载过程的顺利重放。我们的建议已被证实能够产生足够的高性能，只要在我们假设的范围内给出多个网络路径的带宽、延迟和丢包率等参数，就可以以某些指定的播放速率重放视频文件。
Many high performance network links including wireless ones have become available concurrently to access the Internet nowadays. TCP cannot fully utilize the bandwidth of such network link with high latency and high packet loss rate, so the quality of video playback services using progressive download method sometimes deteriorates on such cases. To cope with the problem, some researches have proposed file delivery methods using either one TCP flow on each of multiple paths or multiple TCP flows on one path. However, a promising method which combines these two has not been studied yet. In this paper, we have proposed a progressive download method using multiple concurrent TCP flows on each of multiple paths. In our proposal, some formulae have been proposed to statically estimate the required number of TCP flows according to the network condition on each path at the commencement of a progressive download process. In addition, a block assignment method, which consists of imposing some offset on the block number assigned to the slower path and requesting the block duplicately which has already been requested but prevents the progressive download process from smoothly replaying, is devised to alleviate the influence of out-oforder block arrivals. Our proposal has been confirmed to yield enough high performance to replay video files with some specified playback rate whenever the parameters including bandwidth, delay, and packet loss rate of multiple network paths are given in the range we assume.