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.     

High-Speed Digital Switching Technology Using Space-Division-Switch LSI's

NTT is planning a high-speed broad-band switching network that offers high-speed digital and 4 MHz video services. This paper discusses the hardware design of the high-speed space-division digital switching network and requirements for a switch LSI. In addition, the design and measured performance of a 32 × 32 CMOS space-division-switch LSI are described. In this network, video signals are converted into 32 Mbit/s digital signals by band-compression technology. In order to switch such digital signals, space-division switches are more advantageous than time-division switches. This is because time-division switches cannot multiplex many channels at that bit rate. Furthermore, the use of the space-division-switch LSI is the most effective way to miniaturize the switching system.     

Digital optical CATV system using hubbed distribution architecture

A hubbed distribution architecture based on a bus-star configuration, three-level single single-mode fiber transmission using M-TPC line code, and high-speed IC technology is proposed. The architecture is cost-effective and compact. It is well suited to metropolitan area CATV systems and would allow a gradual transition to a broadband ISDN (integrated-services digital network) subscriber loop in the future. The proposed architecture is applied to a digital optical CATV system prototype. The equipment making up this system consists of a transmitter, hubs including video selectors, and subscriber unit. Two video channels are selected for each subscriber from eight video channels at hub stations. The transmission speed is 900 Mb/s, three-level for the trunk line and 200 Mb/s, three-level for each subscriber loop. Very compact and low-cost equipment is realized by using recently developed high-speed ICs. Experimental results show that the system satisfies requirements and that its commercial application is feasible     

A Field Trial of Fiber Optic Subscriber Loop Systems Utilizing Wavelength-Division Multiplexers

Future subscriber loops will provide various services including broad-band video. Fiber optic technology is the key for introducing these services. The Electrical Communication Laboratories (ECL) of Nippon Telegraph and Telephone Public Corporation (NTT) have been promoting research and development on basic technology of fiber optic subscriber loops, and studying the ways to use fiber optic subscriber loops for new services. As one of the programs, a field trial of fiber optic subscriber loops was planned and conducted in the Yokosuka area from April 1980 until May 1981. This paper first describes fiber optic transmission technologies for subscriber loops. Then, the system configuration and experimental results of the Yokosuka field trial are presented.     

Fiber Optic Transport Systems for Present and Future Local Networks

This paper describes fiber optic transport systems for present and future local networks. The present most important fiber optic system in a local network emerges as a broad-band video distribution system, because large-scale system introduction might be attained only for distributed video services. The system architecture and system parameters are presented. As for future integrated services, a highspeed digital transmission system and local network architecture are very important. The network architecture should be constructed to meet the demands for increased flexibility, capacity, reliability, and economy. Considering expected future demands and technologies, a new fiber optic local network architecture is proposed. The architecture's main features are the use of transmission processing nodes and a multilane-ring structure in subscriber transfer networks in combination with star-shaped subscriber access lines.     

Configuration and Characteristics of a Fiber-Optic Video Distribution System

A multiservice fiber-optic subscriber system using wavelength division multiplexing technology has been developed by Nippon Telegraph and Telephone Corporation to provide both 64 kbits/s and broad-band communication services on a single multimode fiber. The subscriber network is formed in a star topology to facilitate bidirectional connection. The system was put in service in March, 1985, as part of the information network system (INS) model system. This paper describes the configuration and characteristics of the video distribution system of this fiber-optic subscriber system. The distribution system uses analog baseband video transmission at a 0.89μm wavelength. The video channel selection is made by an FDM video tuner installed in a central office. The overall performance successfully met design objectives.     

新一代移动多媒体系统的关键技术研究

新一代移动多媒体系统利用数据压缩/解压缩技术、海量数据存储技术、数字音视频播放技术等多种关键技术,配以宽带网络等多种媒介传递和通信管道,大大拓展了计算机的应用范围,同时也为信息处理技术的发展开拓了新的途径。文中阐述了当前移动多媒体技术面临的挑战,对其发展前景进行了前瞻性的预测,并分析了其主要关键技术的特点和作用,对面临的问题提出了解决方案。     

An Experiment in Integrated Digital Satellite Communications

The experiment we conducted for integrated digital satellite communications is aimed at realizing integrated services digital networks by satellite communication. The experiment was carried out in 1980 using the Japanese experimental communication satellite "CS." This experiment uses 30/20 GHz small earth stations and demand-assignment time-division multiple-access (TDMA) systems. Communications between customer terminals, which contain video conferencing, high-speed facsimile communication, high-speed computer communication, and packet-switching signal transmission, were carried out through the experimental digital satellite link. This paper describes the configuration of the experimental integrated digital satellite communications system and the experimental results of communications between customer terminals.     

基于数字网络的会议系统技术

7会议系统的信息化视听技术将视频(Video)技术、声频(Audio)技术与现代信息(Information)技术相互结合,组成信息化视听系统(Information AV System,InfoAV)是现代会议系统的一个重要发展动向。     

基于数字网络的会议系统技术

讨论现代声频技术的一个重要分支——"会议系统"的组成、特点、相关的国家标准、主要的应用技术及其发展动向。着重介绍近年国内外基于数字网络的会议系统新技术如数字处理和传输、高频和红外传输、NOMA、哑声对应互动、摄像自动跟踪、会议电视、交互数字白板以及多会议室系统控制和声像灯光网络化集控平台等技术,并举出典型的应用实例。     

一种基于GTP的光纤高清视频传输系统设计

为满足视频传输系统对远距离、高清画质、无失真、抗干扰性和稳定性的需求,提出了一种基于GTP的高速串行传输以取代以往的并行传输模式,实现高清视频的无压缩远距离传输。FPGA采集数字视频数据后识别视频格式并经过SDRAM缓存,在GTP中转换为高速串行数据后通过单模光纤传输。GTP在25 Gbit·s-1的速率下传输,接收端对视频数据进行解码、缓存、显示。经过仿真、调试、验证,系统能稳定传输720p、1 080p等8种主流分辨率的视频,且可实时切换。     

1.04 GBd low EMI digital video interface system using small swingserial link technique

In a high-resolution flat panel system, a conventional interface that directly connects a liquid crystal display (LCD) controller to a flat panel cannot overcome the problems of excess EMI (electromagnetic interference) and power caused by full-swing transmission signals in parallel lines. This paper presents a high-speed digital video interface system implemented with a low-cost standard CMOS (complimentary metal-oxide-semiconductor) technology that can mitigate EMI and power problems in high-resolution flat panel display systems. The combined architecture of the high-speed, small number of parallel lines and low-voltage swing serial interface can support resolutions from VGA (640×480 pixels) up to XGA (1024×768 pixels) with significant power improvement and drastic EMI reduction. To support high-speed, low-voltage swing signaling and overcome channel-to-channel skew problems, a robust data recovery system is required. The proposed digital phase-locked loop enables robust skew-insensitive data recovery of up to 1.04 GBd     

基于高速交换网络的软件化宽带数字阵列处理架构

针对宽带数字阵列雷达系统的特点,提出了一种以高速路由交换网络与高速点对点数据传输网络为基础的标准化、模块化、可扩展和可重构的软件化通用宽带数字阵列处理架构,并结合某宽带数字阵列雷达系统的实际需要,详细论述了系统的组成、控制信息和海量数据传输的方式、相关功能实现方案和实测验证结果。该系统实现方案可以有效地提高宽带数字阵列雷达系统软硬件协同开发效率,便于新技术快速应用以及雷达系统功能性能的灵活扩展和提升。     

基于TMS320DM642网络摄像机的设计及实现

现代社会急速向信息社会发展,而多媒体技术是信息化中主要的技术环节之一,它已渗透到各学科领域和国民经济的各个方面。网路摄像机作为多媒体的主要内容,得到广泛的研究和应用,同时也推动了Internet网络,无线移动网络相关的通信技术的发展。数字信号处理器（DSP芯片）,作为快速和实时处理的最重要的载体之一,也得到了广泛的应用。ISO／IEC和ITU推出的音视频编码方面的一系列标准,如H．261、H．263、H．264等,为视频通信提供了前提。论文将网络摄像机硬件系统及其实现技术作为课题的研究内容,介绍了基于TMS320DM642SDSP网络摄像机的硬件实现方案。本硬件系统可广泛应用于数字监控系统、视频会议、可视电话等领域。     

基于PXIE总线的高速CCD数字图像采集系统设计

为实现高速电容耦合器件（CCD）数字图像采集传榆,提出一种基于PXIE总线和CameraLink协议的高速图像采集系统设计方案。设计了CameraLink硬件接口电路,实现了视频数据信号的接口设计、控制信号的接12设计、串行通信信号接口设计;同时采用Xilinx公司的Virtex-5LX50T型FPGA作为PXIE传输控制器,并对IP核进行了开发,减少了外围电路设计难度。创新性地运用直接内存访问的工作方式对PXIE传输速度进行优化。实验结果表明,PXIE配置为8通道时,读取数据速率达到1504MB／s,写入速率达到了1490MB／s,可以满足高速CCD数据的传输要求。     

A CMOS automatic line equalizer LSI chip using active-RC filtering

Using digitally controlled RC-active filtering and a new digital circuit configuration, a CMOS automatic line equalizer LSI has been developed for a digital transmission system. This LSI can automatically equalize line losses of up to 42 dB with 0.2 dB precision even with bridged tap echoes up to two time slots away from the signal pulses, at a transmission rate of up to 200 kb/s. The chip size of 7.0/spl times/7.0 mm is realized through optimized circuit design and double polysilicon CMOS technology. The circuit design concept that permits high-speed operation with high precision and the characteristics of the fabricated LSI are described.     

基于VDSL技术的高速传输单元设计

首先回顾了VDSL技术的发展现状和技术特点,然后介绍了一种单芯片VDSL系统解决方案的结构和基于该技术的高速传输单元设计方案,包括系统基本原理,软硬件设计,并给出了系统的2种典型应用示例和有关测试数据。该高速传输单元具有模块化、灵活配置的特点,配合简单的外部接口电路,可实现一路以太网接口或高速同步接口的有线远距离传输功能,利用单对双绞线作为传输介质,传输距离可达1km以上。     

基于GPRS的ARM7嵌入式单片机视频报警系统

为解决传统视频监控系统中存在的诸多弊端,满足更高的安全需求,提出一种新型的基于GPRS的嵌入式视频报警系统．该系统具有体积小、实时性强、功耗低等特点,并实现了图像的高速采集和传输。它无需处理模拟视频信号的PC机。而是把摄像机输出的模拟视频信号通过嵌入式视频编码器直接转换成IP数字信号。结果表明：该系统对大多数低中速运动物体能有效的发现报警,通过应用GPRS协议,分辨率能达到90％,算法的效率提高8％,传输数据帧的精度提高5％．很好地克服了传统的图像采集系统的缺陷。     

数字电视的进展

数字电视采用先进的信源压缩编码技术以及先进的数字传输技术。它具有很多新颖的特性，因而将有广泛的应用前景。新的数字电视体系正在诞生；它在继承现有模拟电视技术的基础上，将逐步取代现在的模拟电视体系。     

无线Mesh网络技术在油田单位中的应用分析

通过油田数字化建设实现远程视频监控、闯入预警、功图法计量、电子巡井、数据采集等功能,建立起一套现代化的管理决策系统。如何保障数据从复杂的现场地理环境中传输到各个井站管理平台是信息网络建设的难点。通过对油区地理位置和各种网络传输技术分析研究,通过现场试验应用,选择无线Mesh网络组网技术为实现方案,并就无线Mesh网络技术在油田应用情况做以阐述。