将应用层组播技术应用在高清流媒体直播系统中，设计并实现了一个支持大并发、高性能、小延时的高清流媒体直播原型系统，同时创造性地提出了分布式时移技术并集成在系统中，使用户能随时收看直播或延时直播的节目。该系统在2006年夏世界杯期间在复旦大学校园网内进行了长达一个多月的大规模测试，最高在线人数460。测试数据表明该系统很好地解决了服务器出口带宽瓶颈以及普通P2P技术延时较长等缺点，为国家科技部重点项目高清电视的直播系统提供了一条可行的技术方案。

In this paper, we applied ALM(application layermulticast) into HDTV live system, design and implement a multimedia live prototype system with large concurrency, high efficiency and low delay. We also created a distributed time-shifting algorithm, which was integrated in the system in order to allow users to watch both live and delayed TV programs. This prototype system was put into large-scale testing formore than one month in Fudan Campus during World Cup 2006. The result shows that it is a good solution to output bandwidth bottleneck at server side and long delay of normal P2P technology at the client. The maximum amount of online users was over 460. It also provides a good solution to HDTV live system, which is the focus of National Science and Technology Department.