通信与电子信息工程专业英语课文翻译聂敏著单元TEXT.pptVIP

Unit 9IPTV Text IPTV Overview Unit 9 原文： IPTV is an IP network application that supports several high quality video and audio standards (for example, MPEG and H.261) for live video, scheduled video, and video on demand. Unit 9 原文： Generally speaking, IPTV refers to the distribution of television and video signals in parallel with the Internet connection supplied by a broadband operator using the same IP (and mostly the same VoIP ) packet network infrastructure. 译文:一般来说，IPTV是指互联网连接的并行电视和视频信号的分配是由宽带运营商提供的。他们使用相同的IP（大多是相同的VoIP）数据包和网络基础设施 Unit 9 原文：The users can receive and view the contents on a home TV, a PC, or even with a hand-held device on the move. The devices are loaded with an IPTV client. 译文:用户可以从家里的电视、PC机甚至是移动的终端上接收和观看电子菜单。这设备需要从IPTV的机顶盒中下载（电子菜单）。 Unit 9 原文：Content servers house the title collections and the feeds from content producers. The TV contents are usually encoded in a standard format. 译文:电子菜单的服务是从节目的制造商那取材并收集节目的标题，电视的节目表则常常是以一种特定的格式来编码的。 Unit 9 原文：The contents can be broadcast or on demand distribution, all controlled by the schedule server. 译文:电子菜单可以是广播的，也可以是按照一定的服务表格控制的按需发送。 Unit 9 原文：The IPTV server handles user requests and the flows are chopped into a stream of IP packets. 译文:IPTV服务负责用户的请求并将该信号转变为IP数据包的数字流 Unit 9 原文：The IP packets flow through a core IP network. Unlike a vice stream that only requires 64 kbps or less with compression, a compressed video stream needs over a megabit per second to satisfy users’ TV experience. This is the reason for a broadband network connection. 译文:IP数字包通过一个IP核心网。不同于只需64kbps或更小的压缩的语音流，压缩视频流需要超过一个兆比特每秒来满足用户的电视体验。这就是宽带网络的链接点。 Unit 9 原文：To ensure smooth delivery of the TV service, a service provider might need to provide dedicated connections and resources to ensure no interruption in the user experience. Therefore, a guaranteed path from the content source to the final distribution might have to be under watch by a network service provider 译文:为了确保用户电视节目的连续而流畅，服务提供商应提供连接和资源来确保用户在视频体验时不会间断。因此，从菜单资源到最终