日本网络家电示范住房动向

1 前言 在数字化技术的发展过程中,信息家电是一个非常引人注视的一个焦点。有人称:“信息化的网络家电,只要把现有的技术组合一起,就可建立”。为了验证这一观点并实际考察建立网络家电中的问题,日本电子信息产业协会(JEITA)于2002年2月在东京都八王子市多麾新村,利用一栋住房组织了一个由50种家电进行实际展示的网络家电公开示范。有关网络家电的应用实例如表1所示。     

Data Communications in Japan

Aspects of data communications in Japan are broadly summarized in this paper. First, various networks for data communication are described and some examples of data communication services using these networks are mentioned. Next, some topics in data communication technology are outlined. Topics include two large-scale computer projects and R&D on pattern recognition techniques in the data-processing field, standard modems now in use and new modems for PCM transmission and other uses in the data transmission field, optical character readers (OCR) and an audio-response unit, as well as various printers in the data terminal equipment field.     

Cable Communications in Japan

Japanese coaxial toll systems at the end of the fiscal year 1970 had grown to 29 980 km of coaxial cable (including both tubes of two-tube systems). In the next seven years, 1971 to 1977, the requirement is expected to be three times this capacity. Cable transmission systems fully utilizing modem electronics and communication engineering techniques are being developed to best meet this expected growth and to provide new wider band services.     

Optical Communications in Japan

This paper reviews research and developmental activities in optical communications currently under way in Japan. Three major systems: 1) atmospheric optical communication systems, 2) optical-cable systems, and 3) lens-waveguide systems, using various types of lasers and newly developed optical devices and components, have been extensively studied at the Electrical Communication Laboratories of Nippon Telegraph and Telephone (NTT) and other electronic manufacturing companies in Japan.     

Mobile Radio Communications in Japan

After a short historical sketch of mobile communications in Japan, technical problems and future prospects are described. The peculiarities characteristic of mobile communication include complicated radio propagation and requirements for continuous communication and determination of mobile subscribers' location. This paper discusses major problems of future mobile communication, for example, radio propagation, controlling, and switching and radio equipment involved in meeting the future demands of a large number of subscribers over widespread service areas. Effective use of an electronic switching system will enable the mobile communication network to be integrated with existing fixed communication networks.     

无线通信发展走势

简要介绍了第三代、第四代移动通信系统以及移动通信网与因特网、移动通信网与因特网、移动通信网与固定通信网结合等问题,从多个视角探讨了无线通信的发展趋势。     

Future Mobile Communications Systems in Japan

A penetration rate of portable phones became more than 50% in Japan andpeople are getting to expect new kinds of services provided by new generation systems. 3rd generation IMT-2000 commercial service is to be started in the second quarter of 2001 and 4th generation systems became new research target. This paper describes new services that will be provided by IMT-2000 systems in Japan and a concept of the 4th generation system. Major technologies for 4G systems are also presented.     

Microwave and Millimeter-Wave Communications in Japan

This paper reviews the status of research and development in both microwave radio-relay systems and millimeter-wave transmission systems as well as the technical features in these fields, mainly developed under the auspices of Nippon Telegraph and Telephone Public Corporation (NTT). Recent activities have been the development of new solid-state devices and high-capacity systems. The application of solid-state techniques is being extended to systems of both analog and digital transmission, such as the 2700 multichannel telephone transmission system in frequency division multiplexing (FDM)-FM radio-relay system, an experimental 20-GHz PCM radio-relay system capable of 400 Mbits/s pulse transmission, and a guided millimeter-wave system of 800-Mbit/s transmission at 40-80 GHz. The microwave integrated circuit (MIC) is also becoming very important in utilizing these high-frequency regions, which should be a valuable resource in the future when a vast information transmission capability will be required.     

多媒体通信的发展趋势

回顾了视频压缩标准、数据会议、多媒体终端及多媒体网络应用平台的发展概况,阐述了多媒体通信的发展趋势:集语音、视频、数据和Web会议的一体化协作通信平台.     

日本第三代移动通信的发展

日本邮政省依据国内通信市场的发展速度和第二代移动通信系统的不足，制定了２００１年引入第三代移动通信系统的时间表，同时向ＩＴＵ提交了标准提案。在技术选择上，充分考虑ＣＤＭＡ的技术优势，选择了Ｗ－ＣＤＭＡ的空中接口方案。在核心网方面，日本选择了两种有助于后向兼容的技术。为使第三代系统顺利投入商用，几家运营公司已着手开始现场试验。     

光通信新动向

光通信在２０世纪为扩大网络传输容量起到了巨大的作用，在２１世纪将把通信网从电到光推向更高的台阶。本文对最近光通信领域的发展动向进行了归纳和总结，涉及到城域ＤＷＤＭ、ＯＣ－７６８Ｓｏｎｅｔ、光交换、光孤子、无源光网、可调谐激光器、光域业务互连、甚短距光设备和自由空间光网系统等九个方面。     

摩托罗拉宽带通信部专栏边带业务

1引言 现在,模拟同轴电缆系统运营商们可以在不需为额外的转发器而增加投资的前提下享受各种各样的新型电视节目.随着边带技术的发展,一套或者多套数字电视节目可以与模拟电视节目共享现存的转发器.同时,伴随着基于现存转发器的数字边带技术的发展,那些过去被认为需要推迟或者遭受模拟传输技术所排斥的电视业务的实施将成为可能,并且极具吸引力.     

光通信有源器件技术发展与市场趋势

引言 光有源器件在光通信领域具有十分重要的地位.随着全球光通信长途网络日趋饱和,光通信的建设重点转向城域网和接入网,光有源器件及其技术也在向模块化、集成化、多功能、灵活性、低成本方向发展.目前,光有源器件的热点技术是1 0G收发模块、131 0nm VCSEL、无致冷直接调制10Gb/s半导体激光器、小模块化的光转发器、可调谐多波长半导体激光器、40G光调制器技术.     

视频通信的现状及发展趋势

人们对视频通信业务的需求促进与其相关的网络、信息处理、网络接入等技术的发展，同时这些技术的不断发展也反过来促使视频通信业务的不断成熟。未来视频通信业务将会承载于有线可无线Internet上．同时其服务质量也将会满足商业化发展的需要。目前面临的挑战是视频通信应用中会涉及很多知识产权问题、家庭组网尚未形成明确的主流技术，此外还有安全问题和商业模式的建立等。但我国与其他许多国家处在同一起跑线上。存在着许多创新的机会和领域。     

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.     

IP电话业务与日本CATV业界动向

1 前言 日本CATV业者在坚守电视广播业务的经营阵地基础上,曾以宽带的优势开展了Internet的接入业务。现在又乘胜前进进入利用VoIP技术的通信业务市场。 在这种形势下,电信业界是如何评价的?而CATV业者在面对广播与通信相融合的情况下,又是如何处理VoIP业务中的诸多课题的?为供国内同行参考,现就国外杂志(Telecommunication July.2002)报道简介如下。     

日本电子元件的发展动向

简要介绍2002年日本电子元件的发展趋势及市场情况。     

浅述PCB电性测试设备的发展趋势

新的封装技术以及新的工艺将逐步在PCB的制程上使用,PCB的电性能测试将显得格外重要,本文介绍了现阶段PCB电性能测试技术的发展和分类,PCB电性能测试技术和测试设备的现状,未来PCB测试设备的发展方向以及测试设备急需突破的技术瓶颈。     

三网融合大势所趋

对我国电信网、因特网和有线电视网“三网融合”的问题进行了讨论,介绍了“三网融合”的背景和目前三网的现状,论述了“三网融合”需要做的工作。