文档介绍：山东建筑大学硕士学位论文
Server开发了相对应的VOD服务器。考虑到对手机的普遍支持,移动通信门户采用 WAP技术实现,提供节目查询功能,并接收观众基于WAP的点播和播放控制请求, 并通过转发给SRM。,采用RTSP协议控制VOD 服务器发送节目流。 VOD直接发送节目流不同,VOD服务器首先发送提示码流,提示观众在电视上看到提示信息后通过手机进行点播确认。SRM直到接收到确认信息后才指示VOD服务器发送正式节目流,保证用户完整收看。作为系统
实现基础,定义了Portal和SRM间的通信协议,并扩展了SRM和VOD服务器之间的 RTSP协议。
利用移动通信网作为回传通道解决了限制用户接入的瓶颈,面对大量用户点播, 服务器的性能成为服务规模的限制条件。为了实现低成本的解决方案,基于标准服务器构建了VOD服务器集群。设计了负载均衡和冗余节目分配算法,使点播事务分散在各成员视频服务器上,并且在一台服务器出现故障时,其承载的事务能够均匀迁移到其它服务器上。对于热播节目,采用在多个服务器上动态建立副本的方式实现大量并发点播。
关键词:视频点播,,回传通道,移动通信,负载均衡
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山东建筑大学硕士学位论文
The Study of Video on Demand System Based on HFC
AB STRACT
VOD is key service of Interactive TV,the ability of selecting program for viewing freely and controlling playback fully gets rid of the restriction of watching traditional TV
IP-QAM technology uses rest bandwidth after DTV’S transformation to
transmit the program stream,which has the advantage of high transmission is considered as the most appropriate technology of Interactive ,in order to achieve return of user’S on·demand and playback control information,it is necessary to build
additional work as the IP-QAM VOD’S return channel,the user do not demand the
program until he takes advantage of new two—way STB with DVB-C and IP result in some problems such as high cost of Interactive TV’S construction and maintenance, low coverage,without supporting the deployed one—way STB,and SO on.
Because return information of IP·QAM VOD is the small amount of data and delaying requirements are not higll,the method using work as a return channel for the new IP·QAM VOD system is is able to carry data
communications of on—demand and interactive playback control the whole
flow is carried out that the front server is accessed by the mobiles,the program is retrieved, the request of on-demand and playback controlling is submitted,the on-demand program stream is sent to the IP-QAM device in the works and