多媒体广播业务在TD-SCDMA系统中的实现

多媒体广播主要是指移动终端用户在具有操作系统和视频功能的智能移动终端上以频道或信道的形式接收广播形式的数字音视频内容（例如电视等）。多媒体广播有两种主要技术种类：一种是广电系统的大区制的地面广播手机电视标准，另一种是基于移动通信系统蜂窝网的MBMS（多媒体广播和组播技术）标准。本文主要讨论在TD-SCDMA网络中，如何实现MBMS技术来承载多媒体广播业务。     

TD-MBMS技术应用及其组网方案

手机电视业务 手机电视业务根据传输方式划分,主要有基于地面数字广播实现的手机电视、基于卫星数字广播实现的手机电视、基于移动通信网络实现的手机电视3种方式: (1)基于地面数字广播实现的手机电视,在原有地面数字广播电视技术基础上进行改进,使用广播电视频段.例如欧洲的DVB-H、美国高通主推的Media FLO、韩国的T-DMB和日本的ISDB-T等.     

TD-MBMS技术应用及其组网方案

手机电视业务根据传输方式划分,主要有基于地面数字广播实现的手机电视、基于卫星数字广播实现的手机电视、基于移动通信网络实现的手机电视3种方式     

一种基于两网融合的手机电视技术的实现

伴随着数据业务的发展,实时移动多媒体业务正在成为备受用户关注的杀手级应用。其中,基于数字广播的手机电视技术是目前国际上领先的技术,其具有不占用移动链路带宽、高清晰度、高流畅性等优点,国际上只有韩国、德国等少数国家试播或者试运营了该业务。在国内由于该产品涉及广电和移动两大集团,因此存在业务层面移动与广电的竞合、技术层面移动网络与广电网络融合等系列挑战。我们克服了系列挑战,紧跟国际技术发展趋势,设计了一种基于移动网络和数字广播网络融合的手机电视方案,在国内首创带外短信授权方式,在业务上开创了移动与广电业务融合的新模式,并进行了实验,可为用户提供高质量、方便使用的移动视频业务。本文着重介绍我们在移动视频领域技术上的创新工作,并按照以下方式组织：第二部分介绍在技术上国内首创的基于带外授权的两网融合技术体系及其细节,第三部分介绍基于两网融合技术方案设计的业务模式和实验。     

手机电视的两年之惑

不知不觉间，作为双网融合典型业务的手机电视迎来了在中国的两岁生日。但其自身的业务特性注定了它只能在电信系与广电系的激烈竞争中艰难成长。移动运营商赋予它“梦视界”或“视讯新干线”之名，广电系则称之为“移动数字多媒体广播”：前者基于移动蜂窝网技术，终端局限于手机，而后者则基于数字广播电视技术，涵盖了MP4、PDA、数码相机，笔记本等移动终端。     

上海将推出DMB手机电视服务

继韩国今年5月以来透过移动广播卫星MBSat 1及地面移动通信网络为手机用户提供数字多媒体广播（DMB）服务之后，最近从上海传来消息．一种基于地面无线广播电视技术的DMB手机电视业务．已经成功地进行了试验．并将于2006年上半年投入商业化试运行。     

一种基于地面广播的手机电视业务平台解决方案

基于数字广播的手机电视业务被业界普遍看好，是实现三网融合的重要业务。手机电视具备良好的市场发展前景，它将大大增强移动运营商在应用和数据服务方面的能力，为客户提供多元化的业务。提出了一种基于地面广播的手机电视业务平台解决方案，并对业务平台架构和平台接口设计作了分析。     

手机电视的实现技术及其标准

数字多媒体广播技术的出现,为经营空间渐趋饱和的广电媒介和业务收入增长乏力的电信运营商带来了融合的契机,也带来了新的发展机遇。手机电视作为两大产业融合的标志性业务,最近引起了广泛的关注。所谓“手机电视”业务,就是利用移动终端为用户提供视频资讯服务。     

浅谈数字广播和移动多媒体融合中存在的技术障碍

随着移动数据业务的普及、手机性能的提高以及网络传输能力的增强,用手机终端收看电视节目已成为可能。由于手机终端的便携性和可移动性使得手机电视业务比普通电视更具影响力和市场潜力。手机电视自身的一些特点决定了该业务对技术有着特殊的需求,而目前数字广播和移动多媒体融合中所存在的技术障碍,也成为了手机电视市场化和产业化发展最大的障碍。     

融合网络下的手机电视交互

手机电视涉及到电信和广电两大产业,交互式手机电视业务带给用户全新的电视体验,将促进移动通信网络和广播网络在这项业务上的融合,文中从手机电视的运营、业务等角度,对手机电视的交互以及两种网络的融合进行了分析,并指出用富媒体来整合融合的内容。     

An efficient approach for DVB-H handover in DVB-H/UMTS hybrid networks

Handover in Digital Video Broadcasting for Handhelds （DVB-H） aims to provide continuous mobile broadcasting services when a user is traveling through cell boundaries. A good handover control can improve the power efficiency and gain much better reception quality. This letter provides a novel approach for DVB-H handover based on DVB-H/Universal Mobile Telecommunications System （UMTS） hybrid network, which moves the main handover function from the terminals to the networks, so that it reduces the operation complexity of the terminals and increases the power saving. When the terminal can not receive the DVB-H signal in the transmission shadow areas or because of some other reasons, the UMTS networks may offer the same service to users to make the service continuous. As the UMTS networks have the topology of the DVB-H networks, by communicating with the terminals, the UMTS networks can help the terminals to predict the handover, and avoid unnecessary handover.     

DVB-T/H and T-DMB: Physical Layer Performance Comparison in Fast Mobile Channels

Terrestrial or Handheld Digital Video Broadcasting (DVB-T/H) and Terrestrial Digital Multimedia Broadcasting (T-DMB) are two popular broadcasting standards that enable digital television transmissions to handheld receivers. This paper presents a comprehensive performance comparison between the physical layers of DVB-T/H and T-DMB when employed for mobile communications. By exploiting a recently proposed fast simulation model, we assess the BER of the two coded OFDM systems in several realistic scenarios, taking into account Rayleigh and Rice channels, different mobile speeds, inner and outer channel coding, channel estimation, and one or two receive antennas. Our comparison shows that the DVB-T/H physical layer performance highly depends on the delay spread of the channel, whereas T-DMB is less sensitive to the frequency selectivity of the channel. As a result, DVB-T/H yields better performance than T-DMB in typical Rayleigh channels with significant delay spread. On the contrary, at high SNR, T-DMB outperforms DVB-T/H in Rice channels with low delay spread. As a side result, we show the performance improvement of DVB-H produced by MPE-FEC at the data link layer.      

地面数字多媒体广播标准T-DMB

介绍了地面数字多媒体广播标准T-DMB的背景、系统结构与技术特点，并对其相关地面数字移动电视传输技术和业务模式进行了讨论.     

Personal Mobile DTV Cellular Phone Terminal Developed for Digital Terrestrial Broadcasting With Internet Services

Digital terrestrial broadcasting in Japan specifies a service profile not only for fixed receivers in the home, but also for personal mobile terminals such as acellular phones and PDAs. Services for personal mobile terminals are expected to become more attractive with sufficient functionality and flexibility by utilizing the network connectivity of mobile terminals. In order to verify the possibilities of digital television broadcasting (DTV) services for personal mobile terminals and clarify technical problems at the commercial level, we developed a prototype mobile terminal capable of receiving digital terrestrial broadcasting in addition to the Internet. This paper describes the assumed DTV service for personal mobile terminals and the technical architecture of the developed mobile terminal with regard to the hardware and the software. Several experiments using the developed mobile terminal were conducted and the performance was evaluated.     

DVB specifications for broadcast-related interactive TV services

Following on from the early success of the Digital Video Broadcasting (DVB) Project, the next step is to enable DVB-compliant receivers to support an attractive range of interactive services. Various types of interactive services are described. The implications for standards are then listed and the specifications summarised. The specifications include a set of network-independent protocols, as well as specifications for the most popular types of networks for the interaction channel. These cover the public switched telephone network (PSTN) and its digital equivalent (ISDN), as well as cable TV networks. The opportunity exists to enhance the consumer experience by adding interactivity to digital broadcasting. DVB is putting in place some of the enablers to make this a reality     

移动数字电视接收与DVB-H

从接收端的角度出发分析了DVB-H标准在功耗、移动性和服务质量方面的技术改进,并介绍了DVB-H最新进展,对未来移动数字电视的发展提出了自己的观点.     

Outline of ISDB Systems

Integrated Service Digital Broadcasting (ISDB) is the name of the set of digital broadcasting standards in Japan covering terrestrial, satellite,and cable transmission with common format for multiplexing which enable transmission of high definition television as well as data broadcasting. This paper shows the outline of the standards and the updated service features in Japan.     

Broadcasting by satellites

As a result of recent advances in signal processing technology and standards for video compression systems there has been a dramatic increase in interest in commercial applications. This paper reviews the current broadcasting situation from a number of viewpoints relevant to the future development of the available technologies. After a review of the context, which includes alternative new broadcasting technologies as well as alternative media capable of competing with satellite, digital technology is given a wide ranging assessment with particular attention paid to the direct broadcasting to the home by satellite application currently receiving considerable attention world-wide. The possible system architectures and subsystem design features are highlighted with the European Baseline Satellite Broadcasting specification developed by the European Digital Video Broadcasting Project gaining special attention. For completeness a brief review of the digital audio broadcasting system (DAB) is also given. In addition to the applications for direct broadcasting, applications in the professional domain for distributing television signals from studios to terrestrial transmitters, satellite up-link sites or cable heads or for satellite news gathering (SNG) are examined. Features of existing commercially available hardware to support these services are described briefly.     

DVB-H: Digital Broadcast Services to Handheld Devices

This paper gives a brief review of the new Digital Video Broadcasting-Handheld(DVB-H) standard. This is based on the earlier standard DVB-T, which is used for terrestrial digital TV broadcasting. The new extension brings features that make it possible to receive digital video broadcast type services in handheld, mobile terminals. The paper discusses the key technology elements-4K mode and in-depth interleavers, time slicing and additional forward error correction-in some detail. It also gives extensive range of performance results based on laboratory measurements and real field tests. Finally it presents viewpoints relevant for DVB-H network design and system use in general.     

国家地面数字电视推广应用北京地区技术试验

地面数字电视传输国家标准正式颁布后,国家广播电影电视总局组织开展了地面数字电视推广应用技术试验,广播电视规划院承担了本次技术试验工作.本文从技术试验工作的进展以及内容等方面详细介绍了在北京地区开展的地面数字电视技术试验的相关工作.