通信与电子信息工程专业英语课文翻译聂敏著第9单元TEX.ppt

Unit 9 IPTV,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.,译文:IPTV 是IP网络的应用，它为视频直播、预约视频、视频点播提供多种高质量的视频和音频标准（例如MGEG 和H.261）支持。,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，从菜单资源到最终的分配之间的必定的路径必须在网络服务提供者的监控之下。,Unit 9,原文：-Complex Operation Support Systems (OSS) are set up to fulfill service ordering ,service assurance, and billing functions. 译文:为了实现业务的排序、业务的准确性以及工单的（整理）作用建立了综合的运营支撑系统,Unit 9,原文：There are a number of requirements for IPTV to be successful _Quality of service or QoS Some specific QoS mechanisms are required in a bandwidth-constrained access. A bandwidth allocation supported by a session-based admission control function is a reasonable assumption. A flow has to be set up along the whole transmission path. The quality requirements can be adjusted from time to time. Note that such a dynamic QoS scheme might require changes in the QoS policy to be propagated throughout the network infrastructure. 译文:IPTV要成功必须具备以下的几个必要条件： 服务质量 一些特殊服务质量的器件限制了带宽的接入，按照会话来控制带宽的分配是一个合理的假设。流量是按照整个的传输路径来计算的。并且质量的要求要适应时代的发展。值得注意的是这种动态的服务质量标准要随着那些在网络基础设施所宣传的服务质量政策的改变而改变。,Unit 9,原文：_Multicast Use of multicast is a convenience for the operator to minimize network resources and not an essential component of the service definition. Protocol Independent Multicast (PIM) can help decouple the underlying routing protocol from broadcast services, using dense mode or sparse mode through the planning of IPTV coverage and usage in the network infrastructure. The IPTV service needs to be available whether the content is unicast (as in video on demand) or multicast (as in TV broadcast). 译文:组播 组播的应用使得运营商很方便的优化了网络资源，并且这不是服务定义的主要部分。独立多点协议可以通过广播服务有效的减少下属路由协议的损耗，它在网络电视的覆盖计划中以密集模式或者稀疏的模式应用并使用在网络基础设施中。无论信息是单播的（像视频的点播）或者组播的(像广播电视)。,Unit 9,原文：_Authentication context This is similar to the presence service in VoIP convergence. The Internet TV stream can be one element within a communication context. Consider two teenagers watching the same movie (in their respective houses) and instant messaging each other at significant moments during the show. An alternative example is the TV stream as a picture-in-picture option within a multimedia conferencing service. 译文:鉴定/授权/身份 网络电视服务必须授于权一个特定的设备，更多复杂的个性化的授权模式需要一些特殊的服务。例如，家长控制。,Unit 9,原文：Nomadicity For an Internet TV service, nomadicity normally is interrupted as the user being able to access the same service profile from a different location. Performance-to-cost ratio changes are likely to result in handheld devices or portable terminals capable of participating in Internet TV sessions. 译文:通信范围 这就和现存的使用了互联网协议的网络上进行语音传输相类似，网络电视的数据流是通信范围中的一个元素。考虑到两个青年同时观看相同的电影（在各自的房间）并且在观看期间每个重要的时刻瞬时的信息都是相同的。具体的例子就是电视流就像多媒体会议业务中的一幅一幅的画面一样。,Unit 9,原文：_Emergency IPTV needs to continue existing television services to provide content overlays notifying of emergency conditions (for example, a thunderstorm warming). 译文:游牧 在网络电视业务中，游牧通常被解释为用户可以从不同的侧面来定义一些服务的一面。性能与开销的比值的变化很可能直接影响在手持设备或移动终端在网络电视会议中的是否可用。,Unit 9,原文：_Content and service discovery Assisted by a centralized or distributed directory, the user is able to search and locate the video content from the terminals. The search can be text-,picture-.or video-based. The content and the service available based on the content is reported back to the user as the result of search. As the cable and phone service providers are moving into the content service, they face integration of various servers, some of which might contain the same content with varying format, abbreviation, or technology. 菜单与服务的产生 通过集中的或分散的目录的辅助，用户可以从终端查找和定位视频菜单，这种搜索可以是基于文本、基于图片或是基于者视频的。我们称这种业务和基于菜单的可用服务是用户搜索的结果。由于电报或者手机的服务总是在菜单服务中变化，他们面对着各种各样的菜单的提供者的整合，例如，对一个电视节目的菜单的重新搜索要经过网际层对各种的服务层的复用，这也包括很多具有不用格式、缩写、或者技术的同一个菜单。,Unit 9,原文：_Digital rights management IP network security and application security support DRM technology that allows certification of the legitimacv of the original source of the video content, authentication and authorization of the user to view the content, and clear accounting among content creators, producers, traders, and users. 译文:数字化的管理 IP网络安全和应用安全支持技术，它证明了最初的视频目录资源的合理性并且对与用户观看菜单予以授权，明确的阐释了在菜单的创作者、制造者、交易商和用户(的关系)。,Unit 9,原文：_Session management Standard session management control commands must be built on top of the SIP or RTCP or other protocols in order for users to initiate and control delivery. Examples include play, rewind, forward, pause, stop, fast rewind, and faster forward. 译文:会话管理 会话管理控制协议是在SIP 或RTCP或者其他的协议的基础上为了用户的使用以及菜单的控制交付而创造的，其中包括向前、倒换、倒回、暂停、停止、快速倒回和快速倒换。,Unit 9,原文：To meet the IPTV service requirements, a set of enabling capabilities have to provide middleware in the SP space . those enabling technologies are directly supported by a number of IETF protocols including Real-Time Protocol Real-Time Control Protocol ,and Stream Control Transmission Protocol. 译文:为了满足IPTV的业务需求，在SP的容量中的中间设备中留有一系列可用的容量，这些可用的技术支持包括实时传输协议、实时传输控制协议、流量传输控制协议的一系列IETF协议。,Unit 9,原文： IPTV offerings stem from competing needs between cable and phone service providers . Of course, new IPTV technologies and applications ,in turn ,benefit content providers, as well as new user experence. 译文: IPTV的产生起源于电报和电话服务提供者的竞争，当然，作为回报，新的IPTV的技术和应用使菜单的提供者和新用户体验得到了益处,Unit 9,原文：IP services provide a number of benefits: To the users, IPTV technology enables them to select the content they want and pick the time they want to wach. They can use the devices they want and available to them . thin clients will be embeded in various devices. 译文:IP业务提供了下面的好处： 对于用户，IPTV技术可以使他们去选择他们想要的节目以及选择自己的时间去观看。他们可以用自己合适的设备来实现这些。所以便携式电脑就镶嵌在各种各样的设备中。,Unit 9,原文：The content providers add new distribution opportunities. They can provide targeted custom TV services and commerce with the collection of usage data. 译文:菜单提供者增加了很多分配的机遇，他们通过收集用户的数据定向的和电视业务的用户来进行进行贸易,Unit 9,原文：The application service providers can simplify intergration of IP content and services (such as IP packetized weather, games, photos, and music on TV). For example ,TV can be integrated with broadband home dev