DVB兼容机中数据广播接收的设计与实现

在详细分析MPEG－2和DVB标准支持数据广播机制的基础上，讨论了如何在DVB兼容接收机中设计实现数据广播的接收。把解复用以后广播数据的处理分为两个步骤；去包装和应用解释。去包装过程被抽象为数据过滤器，并以多协议封装方式为例说明了过滤器的设计。     

中国教育电视台VBI数据广播系统综述

本较详细地论述了采用MPEG－4方式的VBI数据广播的原理及特点，同时阐述了VBI多媒体课件的制作和接收，以及VBI数据广播在中国教育电视台的应用及未来的发展方向。     

DVB概述

１引言数字视频广播（DigitalVideoBroadcasting，DVB）是一种基于MPEG－２的国际标准传输技术，它包含了HDTV在内多种数字电视格式的的广播和传输。欧洲DVB规划的范围可用图１来表示。信源编码和系统复用都遵循MPEG国际标准。信道编码则根据信道不同有卫星传输、有线传输、地面开路广播几种。由于将来的DVB业务趋向于付费电视方式，因此，DVB系统还需要一个高度可靠的有条件接收系统。２DVB中的信源和信道编码方式DVB包含了信源和信道两部分标准。MPEG－２信源编码采用MPEG－２标准，利用了人体视、听觉的生理特性，把图…     

业务信息(SI)在数字电视广播中的作用

业务信息（SI）是用来描述传送系统、传送内容和广播数据流时间表等的数据，是补充MPEG－2节目说明信息（PSI）的附加数据。这些数据帮助综合接收解码器（IRD）自动调谐，给用户提供附加信息，使IRD能自动设置可供选择的业务。SI提供了电子节目指南（EPG）所需的全部数据，利用SI可以根据不同需要构成功能各异的EPG。     

MPEG-21框架标准和智能信息推拉技术

介绍了智能信息推拉技术的构成，借助这种技术可以提高因特网、数据库系统以及数字电视广播的智能服务水平，并结合MPEG－21框架标准对它的应用前景进行了分析。     

DNP－100应用实例──证券数据的广播与接收

ＤＮＰ－１００应用实例──证券数据的广播与接收福州电信局王健为满足社会对证券信息接收实时性的要求，我们在ＤＰＮ－１００分组交换机上对上海股市行情的数据进行了广播与接收试验，用ＤＰＮ－ＮＭＳ工作站设置广播服务器（ＢＣＳＴ），并开发出一套分组网上证券信息...     

第一讲数字机顶盒技术概述

数字机顶盒是在过渡时期用模拟电视机接收数字电视节目、提供综合信息业务的终端设备，它可以支持几乎所有的广播和交互式多媒体应用，诸如：数字电视广播接收、数据广播、电子节目指南、准视频点播、视频点播、电子邮件、因特网接入以及IP电话等等。     

汤姆逊公司推出MPEG2数字广播设备

汤姆逊广播系统公司已推出其最新的MPEG2／DVB广播系列产品。这些新产品包括一台DBE2110MPEG2业务编码器、DBX2200MPEG2多路复用器、DBM2310QPSK卫星调制器、DBT2600电信网络适配器、DBD2400IRD、DBS291O频道控制器和DBP282M冗余码切换设备。DBX2200MPEGZ多路复用器，可复用或再复用并加扰高达12路的来自MPEGZ／DVH编码器或服务器的MPEGZ业务。DBX2200将接收的数据用于交互式业务，如基于开放式电视平台的业务。通常，DBX2200被放置在数字中心或数字有线电视前端，在那儿进行再复用。DBM2310QPSK卫星调制器…     

业界动态

第一台MPEG－4因特网摄像机和MPEG－4版本2随着MPEG－4版本1的完成,MPEG预计一些产品计划不久将会发布,但看到第一种硬件由SHARP宣布时,人们仍有一种惊奇之感。该公司已于4月开始销售MPEG－4视频摄像机。它在32MB的存储卡上可记录达1小时。资料可以方便地传到PC及作为视频邮件发送或在主页上发布;微软的Windows媒体播放机将像平常一样播放这种文件。采用MPEG－4SimPleProfile的这种摄像机也能记录数字（JPEG）图片,售价6O000日元（约600美元）。MPEG．4版本2“委员会草案”作为MPEG－4送交表决的第2版本,它是以一…     

DSP在数据广播中的应用

无线数据广播是利用现有广播、电视资源的富余部分，增设数据信道进行点对点、点对面的数据信息传输系统。作为数据广播方式，具有有线通信系统不可比拟的优势。首先，数据广播的覆盖面大，信号质量好。可靠接收的范围比广播电视节目的接收范围大。其次，无线数据广播既能固定接收，又能移动接收，而且，接收端设备的价格亦较便宜。第三，开办无线数据广播，投资省，见效快，具有较强的市场竞争力。第四，广播电视多工应用前景广阔，技术手段多样，生命力很强。它包含高、中、低不同的通信速率、能满足不同层次业务的需要，在进入数字广播电…     

An integrated mobile satellite broadcast, paging, communicationsand navigation system

The design of an integrated mobile satellite broadcast, paging, communications, and navigation system is described. Ku-band RadioSat ground stations will broadcast digital audio signals and data packets (including alphanumeric pages and group cells) to mobiles through a satellite to be launched in 1993. Each mobile radio will simultaneously receive L-band digital audio and data broadcasts from the satellite and L-band navigation broadcasts from the Global Positioning Systems (GPS) through a common omnidirectional mobile antenna and receiver front end. RadioSat mobile radios will use GPS broadcasts and differential corrections sent through the satellite to navigate with 2-m accuracy. With optional transmitters, RadioSat mobile radios can support two-way voice and data communications     

Internet over direct broadcast satellites

High-powered direct broadcast television satellites can be used to broadcast high volumes of data directly to home terminals. Using the telephone network or a similar low-speed network, an asymmetrical system can be implemented which offers interactive Internet services. Two such interactive data broadcast systems are described which have been implemented as demonstration platforms for interactive multimedia services; one is based on digital subcarrier techniques for analog television channels, the other on the MPEG-2 and DVB standards. The architecture of the hardware and software is presented, particularly the solutions available for carrying Internet datagrams over MPEG-2 transport systems. A multicast transport protocol with selectable reliability is described which is the basis of a generic distribution application. It exploits the potential benefits of direct broadcast satellites for delivering data to large groups of local caches     

格非播出系统格式解析及在转码软件中的应用

在目前播出系统设备的数字化改造中,通常采用格非MagiStream视频服务器构建硬盘播出系统,但是由于格非硬盘播出系统文件格式的特殊性,一些标准的MPEG-2文件无法直接在格非播出系统中播出,需要通过视频上载方式或格非上载软件的转码上传完成。为了提高播出系统的工作效率,在详细解析格非视频文件、音频文件和索引文件的基础上,找出了标准的MPEG-2视频文件和PCM音频文件与其的差异,并给出了播出系统节目素材转码软件的设计方法。     

Effective multi-program broadcasting of prerecorded video using VBR MPEG-2 coding

The tradeoff between picture quality and bandwidth usage is a prominent issue in the world of broadcasting. Since broadcasters are able to transmit multiple streams simultaneously in a channel, they face the challenge of guaranteeing the contracted picture quality required by each of the transmitted video streams while maximizing the number of video streams carried in each channel. We have developed an easy to implement MPEG-2 based multi-program video coding system suitable for digital TV broadcast, video on demand, and high definition TV over broadcast satellite networks with limited bandwidth. Compared to present broadcast systems and for the same level of contracted picture quality, our system greatly increases the number of video streams transmitted in each channel. As a result, either a large number of transponders can be freed to carry real-time broadcasting or the level of picture quality can be significantly increased. By switching from tape storage to video server technology, the need for numerous playback (VTR) systems at the headend is eliminated. In addition, the most of the complete MPEG-2 encoders are replaced by much less complex MPEG-2 transcoders. All this means a much more cost-effective solution for broadcast stations.     

反馈信道下基于LT码的空间网络广播传输策略设计

由于其特有的广域宽覆盖等特点,数据广播业务一直是空间网络的主要业务。然而空地间信道由于受到远距离、天气变化及遮挡等因素影响,数据传输时延长且丢包率较高。为进一步提高数据广播的性能,该文将反馈信息与LT码相结合,提出一种新的空间网络数据广播传输策略。与传统的数据广播策略相比较,新的传输策略利用反馈信息估计信道丢包率,并在此基础上引入信道状态矩阵和数据包选择权重向量,设计了数字喷泉新的编码方法,进而使得数据在重传阶段能够根据信道状态和重传概率实时调整。仿真结果表明,新的数据广播策略能够实现传输较少数据包的基础上实现原始数据的可靠接收。     

A New Transport Protocol for Broadcasting/Multicasting MPEG-2 Video Over Wireless ATM Access Networks

Because of the telecommunications de-regulation act and progress in wireless technologies, we will see the co-existence of heterogeneous broadband access infrastructures in the broadband video service industry in the near future. In this paper, we addressed the error control issue when transmitting MPEG-2 video streams over wireless access networks for broadband video broadcast or multicast services. An end-to-end transport protocol based on ATM and wireless ATM technologies is proposed. For video services, the underlying transport network should be transparent and quality should be maintained uniformly over all the segments whether wireline or wireless links. For network resources to be used efficiently, error control should be applied locally on the wireless segments so as to avoid the excessive overhead over the reliable wireline portions. Because a broadband video broadcast or multicast service is a one-to-multiple point service, FEC is the most prevalent error control mechanism. Due to the important role of MPEG-2 control information in the decoding process, priority MPEG-2 control information has to be differentiated from MPEG-2 data information, and excess error protection has to be allocated to it in order to achieve satisfactory QoS. Therefore, a header redundancy FEC (HRFEC) scheme for error control is applied at the local distribution centers before the MPEG-2 encoded video streams are transmitted over the wireless channels. HRFEC is an FEC-based selective protection scheme, which allocates extra error protection to important control information. Simulation results show that the quality of the reconstructed video sequence is vastly improved by using HRFEC, when the channel condition is poor.     

Interactive channel for multimedia satellite networks

Multimedia, including Internet traffic, can currently be multiplexed within the DVB/MPEG-2 formats and delivered direct to home users. Traditionally a slow terrestrial telephone link between the user and Internet service provider is used to request data. A direct return channel system will facilitate users' high-bit-rate bidirectional communication via satellite. The return link could be used for the fast Internet access or large data exchanges that will be necessary in a multimedia world. The satellite system not only removes the need for wires but also increases transfer speeds. Satellite interactive terminals can establish network connections via satellite and a ground-based hub. The DVB/MPEG-2 format carries up to 45 Mb/s in the forward link, and a multifrequency time-division multiple access scheme allows up to 2 Mbit/s in the return direction. The return channel of the interactive channel for multimedia satellite networks underwent final standardization by ETSI in early 2000. This article reviews the system concept of a typical implementation. The key features of the return channel air interface, from transmission parameter to login procedure, are explained. In general, Internet packets are expected to be carried via DVB/MPEG-2 in the forward direction and via ATM in the return direction. The IP transportation techniques are described     

A low cost optical storage server for near video-on-demand systems

A near video-on-demand system is one of the most economic and practical applications to provide high quality digital video services through a network in terms of cost, storage and network capacity requirements. In this paper, an optical storage server with a novel data placement and retrieval schemes is proposed for a near video-on-demand system. The proposed data placement scheme on the optical discs fully exploits the periodical broadcast characteristic of an NVOD service to optimize the disc bandwidth utilization. By further applying our retrieval schedule strategy, the buffer requirement of a system can be significantly reduced. In that way, the maximal number of supported streams with the minimal buffer requirement can be easily achieved, The storage system can be applied not only to CD-ROMs storing MPEG-1, but also to Digital Video Disks (DVDs) storing MPEG-2 in the near future     

The DVB project: philosophy and core system

The DVB (Digital Video Broadcasting) project was established to develop comprehensive specifications for digital television broadcasting. In three years it has completed work on a range of specifications covering broadcast delivery by all currently used means. The systems are founded on the MPEG-2 coding and multiplex specifications. Additional elements have been added to meet specific broadcasting requirements. The first DVB services in Europe, and in other parts of the world using the systems, will be of conventional quality, but the DVB systems can be used for transporting any data content, or image and sound formats, required by the programme service provider, including HDTV