基于代理的视频点播系统中节目调度方案

Scheduling Scheme for Proxy-Assisted Video-on-Demand

为了有效地利用视频服务器I/O及网络带宽资源,针对基于代理缓存的节目调度特征,提出一种客户多播补块的视频点播方案·某些客户在播放节目的同时,又作为服务器按一定策略为后续客户多播一部分节目数据,因此,在不增加客户I/O带宽的前提下,通过利用局域网络丰富的带宽资源,有效地节省了视频服务器及主干网的带宽资源,同时对客户请求提供即时服务·此外,本方案自适应于节目流行度,支持任意的客户点播频度,不因无限用户的点播请求而出现带宽瓶颈·仿真结果表明了其有效、可行·

To utilize network bandwidth efficiently, a new video-scheduling scheme named CMP(client multicast patching)is proposed for distributed proxy-assisted video-on-demand. When an appointed client plays out a video, it is also acting as a server to transmit the patching segments via multicast for subseguent clients in local network. Therefore the abundant resource of local network bandwidth can be utilized fully instead of remote server and backbone network bandwidth, without extra I/O bandwidth needed by the appointed client and with instantaneous services provided for client requests. In addition, the CMP scheme is adaptive to video popularity and supports all client request rates without bandwidth bottle-neck. A simulation shows that significant network resource can be saved by use of CMP scheme.