Transcasting: Cost-Efficient Video Multicast for Heterogeneous Mobile Terminals
Transcasting: Cost-Efficient Video Multicast for Heterogeneous Mobile Terminals
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DOI：
10.1109/iwqos.2008.25
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发表时间：
2008-06
期刊：
影响因子：
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通讯作者：
M. Tamai;K. Yasumoto;N. Shibata;Minoru Ito;K. Nahrstedt
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文献类型：
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作者：
M. Tamai;K. Yasumoto;N. Shibata;Minoru Ito;K. Nahrstedt
提出了一种低成本的视频组播方法，用于通过内容分发网络(CDN)向异类移动终端发送实时视频流。内容分发网络由视频服务器、多个具有无线接入点的代理以及服务器和代理之间的重叠链路组成。在该方法中，通过让代理根据用户的需求执行转码服务，将服务器发送的原始视频转换为多个质量不同的版本，并沿着视频交付路径分发到移动终端。为了抑制CDN中所需的计算和传输开销，我们提出了一种计算代价有效的视频传输路径的算法，该算法最小化代理的计算开销和覆盖链路上的传输开销之和。我们的基本思想是以负载均衡的方式将转码服务放置在不同的代理上，并从所请求的质量的所有转码点构造一棵最小Sterner树。布局的总体目标是在计算和转移成本之间取得平衡。通过仿真实验表明，与其他算法相比，该算法能够计算出更低成本的视频传输路径，并获得更低的请求拒绝。
This paper presents a cost-efficient video multicast method for live video streaming to heterogeneous mobile terminals over a content delivery network (CDN), where CDN consists of a video server, several proxies with wireless access points, and overlay links among the server and proxies. In this method, the original video sent from the server is converted into multiple versions with various qualities by letting proxies execute transcoding services based on the users' requirements, and delivered to mobile terminals along video delivery paths. To suppress the required computation and transfer costs in CDN, we propose an algorithm to calculate cost-efficient video delivery paths which minimizes the sum of the computation cost for proxies and the transfer cost on overlay links. Our basic idea for deriving cost-efficient delivery paths is to place transcoding service on different proxies in load-balancing manner, and to construct a minimal Sterner tree from all transcoding points of requested qualities. The overall goal of the placement is the balance between computation and transfer cost. Through simulations, we show that our algorithm can calculate more cost-efficient video delivery paths and achieve lower request rejections than other algorithms.