Interactivity in broadcasting and its application to ISDB services

Given that broadcasting is generally characterized by real-time one-way transmission, it is an essential task for this medium to provide interactivity developed in the fields of telecommunications and computers when introducing multimedia into a broadcasting system. This paper discusses how to use and implement interactivity in broadcasting services. It further discusses what functions are required for introducing interactivity into broadcasting. The practicality of interactive services in one-way broadcasting transmission is clarified. A simulation system of ISDB services to evaluate viewers' human interface was developed. The results of experiments using the simulation system are also discussed. It is shown that user-friendly ISDB services can be achieved     

基于CATV的数字多媒体广播系统

现在家庭上网多采用电话拨号方式,但由于信道拥塞,信息流通经常受阻,这种方式无法满足大众对信息的需求。为此开发了基于ＣＡＴＶ的数字多媒体广播系统,系统采用非对称数据推送方式,使用信息代理,发送和接收机制使人们方便快速地获取因特网上的信息。     

“手机电视”还是“移动多媒体广播”？

除了在IPTV问题上彰显电信与广电的竞争合作关系之外，近日“通过手机看电视“的业务再次出现了“两电”割据的新情形。近两年来，“手机电视”均被中国两大移动通信运营商视作未来杀手级的业务之一，处在不断推广的阶段。当然，这些业务同样是广电未来重要的市场之一，广电决不会“袖手旁观”的，除了今年4月紧急叫停各地纷纷上马的手机电视（电信系）之外，广电为了进一步巩固和扩大自己的市场和用户，抓住新业务带来的市场新机遇，     

地面数字多媒体电视广播传输系统研究

描述地面数字多媒体电视广播传输（DMB-T）系统结构,对该系统的分层传输特性、同步性能、抗干扰性和抗多径性能进行了讨论,同时介绍了设计实现的流程。     

Real-time multimedia broadcasting via direct-detection fiber-opticsynchronous CDMA networks

A new coding architecture for M-ary fiber-optic synchronous code division multiple access (CDMA) network is proposed to provide real-time multimedia broadcasting. In contrast with variable bit rate (VBR) transmission, the constant bit rate (CBR; i.e. isochronous) transport is more preferable in view of the networking simplicity. We apply a bit-stuffed unipolar m-sequence and maximum a posteriori (MAP) receiver in the proposed network. The system performance is determined by the following parameters: (1) number of simultaneous access broadcasting hosts K, (2) received laser power, (3) input bit rate, and (4) the dimension of M. Furthermore, the adverse impact (thermal noise, APD noise) in the photodetection process is carefully analyzed. Numerical results reveals that for the binary case, the aggregate capacity can achieve 10.2 Gbps     

China formally issued mobile multimedia broadcasting industry standard

October 24, 2006, China SARFF （State Administration of Radio Film and Television） formally issued the China mobile multimedia broadcasting （namely, Mobile TV） industry standard. The standard is a STiMi standard self-developed in China and put into practice from November 1 this year.     

中国移动多媒体广播(CMMB)测试接收机的设计与实现

为了加快CMMB的推广和应用,全面评估CMMB网络的性能,尤其是测试CMMB的移动接收效果和城市覆盖效果,文中提出了一种基于CY7C68013A芯片的CMMB网络测试接收机的设计方案。本方案采用CY7C68013A芯片为控制核心,利用CY7C68013A芯片的GPIO口模拟的I2C、SPI总线通信接口和USB接口与PC机通信等技术,实现了CMMB信号参数存储、读取与CMMB码流播放同步进行的功能。     

移动多媒体广播技术的应用和实践研究

随着我国科技的快速发展,对于移动多媒体技术的需求越来越广,成为我国未来广播事业的趋势,其不受时间和空间的限制,符合当代人的生活特点。文章介绍了移动多媒体广播技术的特点,总结了移动多媒体广播技术的应用途径,阐述了移动多媒体广播技术的实践,希望能够为我国进一步完善数字化技术提供一些建设性意见。     

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.     

卫星数字多媒体广播系统应用前景广阔

国际电联（ITU）于1997年接受世广系统为国际卫星数字声音和多媒体广播推荐标准之D系统，并建议世界各国选择使用。2000年8月，中国通信广播卫星公司和世广国际有限公司达成合作协议，由中国通信广播卫星公司独家代理经营世广“亚洲之星”东北波束的信道租赁业务，从而将世广系统引进中国。此项业务的引入，将对国内的数字广播市场产生巨大而深远的影响。世广系统的组成空间段世广卫星系统由3颗同步轨道卫星组成，分别称为“亚洲之星”、“非洲之星”和“美洲之星”。每颗卫星覆盖三个区域，分别为亚洲、非洲、拉丁美洲以及欧洲的部分地区…     

QoS-aware adaptation for satellite multimedia broadcasting via hierarchical packet scheduling

With the unique broadcast nature and ubiquitous coverage of satellite networks, the synergy between satellite and terrestrial networks provides opportunities for delivering wideband services to a wide range of audiences over extensive geographical areas. This article concerns the optimization techniques pertinent to packet scheduling to facilitate multimedia content delivery over the satellite with a return channel via a terrestrial network. We propose a novel hierarchical packet scheduling scheme that allocates the resources at different parts of the network in response to network dynamics and link variations while under the system power/resource constraints. Simulations prove that the HPS scheme can effectively improve the end-to-end performance and resource utilization with desirable scalability and fairness features.     

现代远程教育卫星电视多媒体广播网络概述

1　现代远程教育广播电视应用系统分析现代远程教育应根据不同的业务要求 ,充分利用现有技术手段 ,完成制作、传送、接收等任务。现代远程教育规模大、范围广 ,应用的设施和设备多 ,投资较大 ,采用合理的优化配置 ,能够取得好的经济效益。我们可以从以下几个方面加以考虑 :1.1　电视节目制作设备电视节目制作设备品种很多 ,档次不同 ,价格差距较大 ,制作的流程也不全相同。从技术发展来看 ,用户应考虑采用以计算机为主体的功能越来越强的后期制作非线性编辑系统。如目前用于ＭＰＥＧ - 2非线性编辑的ＰＣ插卡价格 ,有的已降至 2～ 3万元 ,很…     

中国移动多媒体广播智能网络监测系统的设计与实现

为测试CMMB网络的覆盖情况,文中设计了基于处理器STM32及GPRS无线通信方案的CMMB智能网络监测系统。处理器通过解调模块和GPS模块采集信号质量的相关参数和地理位置信息,并通过GPRS模块将信息发送给服务器,同时接收服务器端的命令,完成终端与服务器的双向通信。终端利用太阳能供电,使其可长期工作在缺少电源、无人监管的状态下。经测试,系统工作性能稳定。     

Active learning through multimedia

As a child, did you learn how to walk by taking a walking class? No. Children learn by doing. Then why force them into passivity in school? Properly designed educational software on multimedia computers supports active participation and puts the student in control. Such software demands the right teaching architecture, as explained here     

Performance of cofdm for satellite digital audio broadcasting

This paper analyses the performance of a coded orthogonal frequency division multiplexing (COFDM) based system for digital audio broadcasting using a highly inclined orbit satellite constellation. The sources of performance degradation considered are non-linear amplification in the satellite transponder and multipath propagation for mobile reception. Despite its strong peak-to-mean amplitude variation, COFDM has been found to be very robust against non-linear amplification. In the multipath channel, practical cases demonstrate low performance losses even in highly populated areas when highly inclined elliptical orbits (HEO) are used.     

CATV网多媒体数据广播系统中控制策略的研究

为了充分利用现有的ＣＡＴＶ网络资源,更好地向用户提供信息服务,开发了基于ＣＡＴＶ网的多媒体数据广播系统,它能够提供多种信息服务。当多个用户同时请求服务时,可能会出现数据广播通道的拥塞,因此需要对系统进行流量控制和拥塞控制,提出了数据广播系统中突发业务的自学习控制模型,在此基础上,控制器针对不同网络传输状态采取不同的控制策略。     

一种新的地面数字多媒体/电视广播传输系统

针对传输信道线性时变的宽带传输信道特性,设计了一种时域同步正交频分复用（简称TDS－OFDM）的多载波调制方式。这种调制方式既适用于具有多径干扰和多普勒频移的地面数字电视广播传输信道,也适用于其它宽带数字传输系统。为了进一步提高传输效率,提出的地面数字多媒体／电视广播DMB－T传输系统还采用了最新的纠错编码和交织编码技术,在额定的8MHz带宽中,净载数据传输率可达32．511Mbps。     

Energy optimization in wireless broadcasting through power control

We consider the problem of optimally controlling transmission power in a time-slotted wireless broadcast network. Fixed-length packets and AWGN channels are considered, and a simple ARQ scheme (Send-and-Wait) is used for error control. Packets are retransmitted until a minimum QoS requirement is met for each packet. Transmission powers are chosen from a finite set depending on the number of nodes that have received the packet successfully. The goal is to minimize the total energy expended for each successful packet transmission. The system is studied when the transmitter chooses between two distinct powers, and the results are then extended to multiple powers. It is observed that the optimal policy is always of the separation type. Also, the effect of varying the QoS requirement on the energy and service time is studied.     

Performance evaluation of broadcasting strategies in cognitive radio networks

Broadcasting is an important phenomenon, because it serves as simplest mode of communication in a network, via which each node disseminates information to their neighboring nodes simultaneously. Broadcasting is widely used in various kind of networks, such as wireless sensor networks, wireless networks, and ad-hoc networks. Similarly, in cognitive radio networks (CRNs), broadcasting is also used to perform many tasks including neighbor discovery, spectrum mobility, spectrum sharing, and dissemination of message throughout the network. The traditional approach that has been used as broadcasting in CRNs is simple flooding in which a message is disseminated in the network without any strategy check. Simple flooding can cause major setbacks in the network, such as excessive redundant rebroadcasts, and collision drops which collectively are termed as broadcast storm problem. To reduce the effects of broadcast storm problem in wireless networks, we propose and compare four broadcasting strategies for cognitive radio networks in this paper. These four strategies are: (1) probability based, (2) counter based, (3) distance based, and (4) area based. Extensive NS-2 based simulations are carried out on different threshold values for each broadcasting strategy. After experimental evaluation, it is demonstrated that counter based broadcasting surpasses other broadcasting strategies by achieving maximum delivery ratio of 60% and by decreasing redundant rebroadcasts and collision drops up to 44 and 37% respectively.