超宽带技术在数字有线电视系统中的应用

目前全国各地正在积极推广数字有线电视,其中如何开展各种增值业务成为一个重要课题。文章首先简要介绍了数字有线电视和超宽带技术,然后给出了两种超宽带技术在现有数字有线电视系统中的应用方案,利用这些方案可以有效地开展各项增值业务。     

数字CATV的有条件接收

有条件接收系统是开展数字CATV增值业务的基础,是确保数字电视健康发展的一个重要技术保障系统.鉴于该类系统的特殊性和重要性,着重介绍了数字CATV有条件接收系统的5项关键技术.     

有线数字电视系统中超宽带技术的应用

目前各地有线电视网络正在全面推广数字电视,其中如何开展各种增值业务成为一个重要课题.首先简要介绍了超宽带技术,然后给出了两种超宽带技术在有线数字电视系统中的应用方案.     

CAS增值有线电视网

20 0 0年 11月 2 2日 ,清华同方股份有限公司正式推出基于CATV网的全数字有条件接收系统 CAS,解决了有线电视台等宽带网络运营商为广大普通用户提供个性化服务的授权限制及收费问题。对于 CATV网来说 ,传统业务将逐步被多媒体技术核心的增值业务所取代 ,为了更有效地开发CATV网的应用价值 ,清华同方确立了烽火台项目 ,旨在在再有的有线电视网上建立宽带信息及应用平台。此次开发的 CAS系统是宽带网络运营商开展增值业务的基础 ,也是交互式个性化电视走进生活的基本实现条件。通过该系统 ,有线电视台可利用现有的宽带网络和卫星传输…     

基于双向CATV系统的增值业务

采用Cable Modem技术将HFC网建成高速数据交换网络是利用现有资源开展增值业务的主要手段，从组网的原理与功能等方面对利用双向CATV系统开展宽带综合业务、视频点播、小区住宅智能化管理以及可视对讲门禁等的方法进行分析。     

利用CATV网络开展宽带交互式综合业务

本文着重介绍了利用CATV网络开展宽带交互式综合业务;具体包括通过CATV网访问Internet、CATV网上的数字数据网络(DDN)系统、数字视频广播(DVB)和视频点播(VOD)及其相关的技术问题等。     

基于CATV的数字宽带综合信息网络的应用

本文结合目前中国数字电视增值业务的实际情况，详细介绍了基于CATV的数字宽带综合信息网络的几种增值业务的应用，给出了市场前景分析。     

美国CATV的数字应用与网络测试——SCTE′97专题讲座系列报道(三)

1 前言 目前,美国的许多CATV经营者,在图像业务之外,正在利用CATV设施的宽带特点,准备开展数据传送等数字业务。在开展新的数字业务时,尤其对传送带宽(与传送速率相关)和可靠性方面,与以往模拟业务相比有着更高的要求。     

美国SCTE’94与CATV技术新动向(下)

3 美国 CATV 数字技术应用的发展3.1 数字技术3.1.1 数字技术在 CATV 中的应用概况在建立信息高速公路的设想下,数字化技术对于 CATV 系统,主要体现在下一代CATV 中如何更完美地实现多频道化和多业务化。下文拟就有代表性的新业务开发情况和频道容量发展趋向作一概述。3.1.1.1 下一代的频道容量关于未来的数字化 CATV 系统,美国FCC(联邦通信委员会)主要采取民间先导的方针,由各个厂家进行着各自的实用化实验,具体典例可参阅表2。     

基于EPON＋HEoC＋LEoC技术构建广电双向网

EPON＋HEoC＋LEoC技术是在现有HFC网络基础上构造的适用于广电网络系统的数字带宽用户接入网络,它在不影响现有CATV正常工作的前提下,以先进的调制解调技术,将以太网信号合成在同轴电缆中与原有的CATV信号一起传输,用于承载基于IP的数据、语音和视频等业务。     

On management of CATV full service networks: a European perspective

The CATV network operators hope to offer digital services and evolve their networks to full service networks. There are many hurdles for them at the moment in the transition to a digital network and digital service offering from the current analog-based technology. Key to the success of the transition will be a well-integrated and capable management system to allow CATV operators and service providers to control the network as well as the services they will offer. The CATV operators need to agree on a common data communication infrastructure and plan how their new digital services will be offered to subscribers without disrupting the current customer base of analog service users. The choice of network technology and data communication protocols will have a strong influence on the network management technology chosen. A vital element for the provision of a common open communication architecture as well as for the purposes of network management is that the IP is used. The adoption of existing standards is vital in order to establish a fast route to open network management for CATV networks. It is possible that CATV operators and service providers will have to integrate existing SNMP management systems and TMN/OSI management, with newer integrated service management systems based on TINA and implemented on a CORBA platform. There is a strong need to address security issues before any of these technologies can be deployed for service. There is currently investment (deployed systems and research) which uses each of the technologies mentioned, so these technologies will need to coexist. This article highlights the differences between the North American and European network architectures, and outlines the European network and network management scenario. This is based on the authors involvement in a Pan-European CATV project, Integrated Broadband Communication over Broadcast Networks-IBCoBN     

Upgrade of coaxial CATV networks for upstream high speed digitalcommunication

There is a growing interest to extend existing coax CATV networks to enable interactive multimedia services. In this paper we describe necessary modifications and additions of CATV network components to provide broadband upstream channels in the range of 6 to 40 MHz. To investigate linear and nonlinear distortions, reflexions, noise and ingress, suitable digital modulation schemes and adaptive equalization, the CATV network-components are modelled and a computer simulation program using PTOLEMY is established. It is shown that all 3370 subscribers of an existing CATV sub-network can be provided with up to 25 kbit/s collision free on the physical network layer. Using appropriate teletraffic and media access control protocols, user bit rates of up to 2 Mbit/s are feasible in the upstream direction     

基于DVB-C的流媒体广播系统实验研究

设计并实现了一种流媒体广播系统,它用于DVB-C有线电视广播网平台,实验结果验证了有线电视广播网中流媒体传输的可行性,为现有的DVB-C数字有线电视系统开展流媒体业务提供了一种从发送端到接收端的解决方案.     

数字电视信号在线测试系统在有线电视干线网络中的应用

主要分析了现行的有线电视干线网络中数字电视传输技术的特点,以及这些特点给传统的运营维护工作带来的难点。同时介绍了一种利用远程数字电视信号监测系统来解决以上问题的办法,实际工程应用证明了该系统具有显著的使用价值。     

数字技术与CATV综合网

简要介绍了数字技术的特点和ＣＡＴＶ网的发展情况,探讨ＣＡＴＶ综合网在技术规程上的可行性。     

CATV中的数字电视技术及其应用

随着电视信号格式的数字化发展,CATV中的数字电视技术成为人们研究的一个热点.分析数字电视技术及其应用视频业务.     

无线超宽带调制方式现状与展望

超宽带UWB(UltraWideBandwidth)技术是无线通信中的一个非常有发展前途的技术。介绍了UWB的基本概念,分析了UWB常用调制方法的基本原理,说明了各种方法的频谱特性,最后比较了UWB各种调制方法的优劣,指出了UWB调制方法的研究方向。     

Present Trends in High-Speed and Broad-Band Communications Services in Japan

This paper describes present trends in high-speed and broad-band communications services in Japan. It gives an overview of video, high-speed digital leased circuit and satellite digital communications services, and gives examples of their applications. Recent trends in telecommunication services and technology are described, including video conferencing services presently available in more than ten cities throughout Japan, as well as a video response system which is about to be put into service. It also describes the present status of Japan's cable television (CATV) system and discusses its future development. Finally, NTT's plans for high-speed and broad-band communications service in the future are previewed.