中文摘要：

通过研究大规模汇聚路由器（ACR）网络结构特点和IPTV业务的组播组切换步骤,提出一种ACR下的先复制、后鉴权的频道快速切换方法,减小了频道切换时延,提升了用户体验。该方法通过各部分时延的相互覆盖,并行处理切换步骤,达到了缩短总时延的目的,形成频道快速切换。由仿真得到的各关键参数的分布图显示,与传统的频道切换方法相比,所述方法进一步减小了频道切换时延,得到了很好的效果,同时不需要增加任何额外带宽和设备复杂度。

英文摘要：

This paper presented an improved method based on large-scale access convergence router（ACR） with thinking both the character of ACR network and channel change process of IPTV,which reduced the zapping delay and advance the QOE.By dealing with zapping processes at one time,the new method had the sum of all parts of delay shortened.The distribution curves of some key parameters by simulation show that the proposed method achieves the shorter channel zapping time compared with traditional method,and without increasing bandwidth consumption and complication of network equipments.