Services Integration and Multiplexing for Broad-Band Communication Systems

In broad-band communication networks, a number of services are simultaneously available to the subscriber. The issues of service integration and multiplexing techniques, and their impact on network topologies, are addressed in this paper. Alternative realizations of broadband networks, together with necessary electrical and optical components, are discussed. A comparison between the different alternatives is also made.     

Design of a Switched Broad-Band Communications Network for Interactive Services

The congestion in broad-band communications networks resulting from the increased demand for interactive services is considered. It is shown that services such as a video library could not be provided to the majority of subscribers in a conventional CATV network. A design is developed for a space division multiplex broad-band network which can be expanded at minimum cost to meet an increasing demand for interactive services. The network contains two signal distribution networks: a cablecast system similar to the Rediffusion system, and a switched communication network providing point-to-point circuits for both one-way and two-way services. All broad-band signals are transmitted to the subscribers in the 1- to 10-MHz spectrum, permitting the use of twisted pair video cables and a minimum number of cable amplifiers. The broad-band cable network (BCN) is organized around 15 local switching exchanges and one central exchange. Multipoint switches in local exchanges under wired-logic circuit control connect individual subscriber communication lines to any channel. Crosspoint matrix switching groups in the local and central exchanges connect communication circuits in the broad-band communication network under programmed computer control. This network is accessed via links terminating on one channel of the multiposition switches. Per-subscriber costs are estimated to be 190 dollars for a cablecast system serving 3800 subscribers. Additional expenditures per subscriber of 40 dollars for fixed costs and 40 dollars for variable costs would provide interactive services. The range of interactive services provided would be extremely flexible, including both one-way video library service and point-to-point two-way communications.     

Optical Fiber Facilities for Subscriber Loops

This paper gives an overview of the introduction and subsequent development of optical fiber cable and its application to subscriber networks enabling economical broad-band services, such as video and high-speed digital data transmissions. This paper also outlines NTT's developments on subscriber optical fiber cable technology-in particular, the five-fiber ribbon cable structure, mass-fusion splicing machine, and multifiber connector-in its ongoing endeavors to establish economical and flexible subscriber optical fiber networks which provide optical fibers to each subscriber.     

浅谈宽带用户接入方式

提出了通信从窄带走向宽带后,电信网面临的新课题。认为需对原有电信网,特别是用户接入网进行改造,介绍了可用于改造的ＡＤＳＬ、光纤用户接人网、ＨＦＣ等用户接入方式     

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.     

对光纤用户接入设备的探讨

介绍了用户接入网的发展, 光纤用户接入设备的组成和功能, 光纤用户接入设备与交换机远端用户模块、用户数字环路设备的比较,以及光纤用户设备引入对本地网建设的影响。     

The fiber-optic subscriber network in Japan

Nippon Telegraph and Telephone Corporation (NTT) has two primary aims regarding the installation of optical fiber cables for subscriber networks as the access network: to provide high-speed broadband services, and to provide narrowband services through optical fiber cables with subscriber-line multiplex technology. Thus, NTT is preparing an infrastructure to support the forthcoming B-ISDN subscriber networks. NTT has been developing technologies for implementing the full-scale construction of fiber-optic subscriber networks. The present article describes the deployment methodology for these networks, their current status, and plans for their future development     

国外光集成／光电集成技术的发展

ＰＩＣ／ＯＥＩＣ是实现长距离大容量光通信网、光用户网、光交换等关键器件。本文主要介绍了最近两年国外半导体材料技术、工艺技术的进展以及ＰＩＣ／ＯＥＩＣ器件的研制状况。     

An overview of broad-band access technologies

The provision of broad-band services based on either the Internet or the asynchronous transfer mode (ATM) technique requires a new generation of access networks. In the short term, solutions such as x-digital subscriber line (DSL) and hybrid fiber coaxial (HFC), allowing the reuse of existing infrastructures look very promising. For the longer term, new infrastructures based either on radio or on optical access links seem preferable. Three x-DSL techniques aiming at high-bit-rate transmission over twisted pairs are presented: high-bit-rate DSL, asymmetrical DSL, and very-high-bit-rate DSL. An extension of existing cable television networks known as HFC is also described. Two other prospective approaches, wireless in the loop (WITL) and fiber in the loop (FITL), are then presented. Several techniques are considered for WITL: digital enhanced cordless telecommunication local multipoint distribution service, wireless ATM, and low Earth orbit satellite constellations. The various architectural alternatives for the FITL approach are discussed, a special interest being dedicated to the synchronous digital hierarchy self-healing loop and the ATM over a passive optical network. We mention the main experiments and the standardization activities inherent to the domain     

WiMAX点对点宽带无线接入容量分析

随着通信技术的迅猛发展,移动宽带化和宽带移动化是通信网发展的必然趋势。WiMAX城域网无线宽带接入技术,可提供大范围及高速率无线接入,同时支持视距传输和非视距传输,能提供面向互联网的高速无线连接。WiMAX可作为线缆和用户数字线的无线扩展技术,实现无线宽带接入。首先简要介绍WiMAX的应用模式,然后重点分析其点对点应用中上行链路和下行链路的通信容量,提供相关工程技术人员进行方案设计的参考。     

The Broadband Access Facility

The deployment of broadband access networks will revolutionise many aspects of society in the early years of the next millennium. Manufacturers, telecommunications providers and cable television operators world-wide are investing heavily on research into networks that provide broadband multimedia services to customers. BT has developed a prototype of a full service access network that can connect customers via optical fibre, digital subscriber line or radio technologies. This paper describes the physical implementation of the prototype network and the wide range of services that it can support.This prototype network, referred to as the 'broadband access facility' is enabling BT and its partners to understand the best access architectures for a given environment through practical testing. The network now serves as an experimental platform, that can be used for communicating broadband concepts, designing operational processes, developing management solutions and testing advanced applications.The full service access networks (FSAN) initiative is a collaboration involving fourteen of the world's leading telecommunications network operators and major equipment manufacturers. Its vision is to create a shared requirements specification for access systems supporting narrowband and broadband services. This common specification will mean that broadband network components can be developed for world markets, thus raising volumes and driving down unit costs. The common system specification is based around an ATM/SDH (asynchronous transfer mode/synchronous digital hierarchy) core network, with local optical fibre distribution via an ATM PON (passive optical network). DSL (digital subscriber line) systems maximise reuse of existing copper plant. The exact DSL system used depends upon where the optical system is terminated, e.g. in the local exchange, cabinet, kerb or home. Hence this broadband access system can support a range of access architectures — this flexibility is fundamental to the consensus achieved in FSAN.     

Data Transmission Implementation on Broad-Band Networks

Broad-band networks present many advantages for the implemention of data transmission circuits. Whereas communication system concepts are universally applicable, there are many unique details and practial considerations involved in design and operation of broad-band networks. This paper describes broad-band configurations and their system design implications and includes a discussion of current modem designs, spectral occupancy, and modulation characteristics configurations and protocols, interference, and error control, as well as broad-band network control and maintenance. In addition, a data transmission network addressing many of the basic factors and providing multiple services is described.     

A Review of Broad-Band Fiber System Activity in Japan

In the future information society, various kinds of services will be required in offices, factories, homes, and communities. Fiber optic broad-band systems will play the most important role in the integrated services networks that will provide such services. This paper reviews field trials of fiber optic broad-band systems in Japan, focusing on subscriber loop system technology.     

光纤通信网技术的发展

本文综述公用通信网和专用通信网利用光纤传输的发展趋向。公用通信网将向数字化、综合化、宽带化、和智能化发展,最终成为B-ISDN。为此,通信网将从铜线过渡至光纤,从窄带过渡至宽带,从异步过渡至同步,从电路交换过渡至分组交换。全国传输网将是同步光纤网(Sonet),最后必然是“光纤到家”,从用户至用户的全程传输是光纤。另一方面,大企业、大机关急于实现自动化,各自建设专用的光纤局部区域网(LAN),从计算机通信进至综合业务。很可能专用ISDN比公用ISDN更早出现。住宅区需要通过光纤选收电视(CATV)。未来的公用市内用户网和专用局域网,将为光纤产业开辟最大市场。     

Present Status of Mechanical Connectors for Optical Fiber

Trunk transmission network systems connecting exchange offices were the first transmission systems using optical fiber cables. Subscriber network systems connecting the exchange office with each subscriber including local area networks or CATV network systems are under development at present. Two main techniques are newly required to be developed for making optical fiber mechanical connectors for optical fiber subscriber network system realization. The first is to realize a new connector with a high return loss and a low connecting loss. The second is to cut the joining cost of optical fibers. The newly developed "optical contact connector" realized a high return loss of more than 25 dB and a low connecting loss of 0.15 dB average value. A newly developed "multifiber connector" which can connect many optical fibers at the same time can save time and space for joining fiber cables, and also a "plastic molding technique" can save the cost of the connector. The performance of all these connectors is the same as that of the "optical contact connector." This paper describes the present status of the technique to obtain a high return loss connector, a multifiber connector, and a plastic molded connector for the subscriber network system.     

Proposal of networking by PON technologies for full and ethernet services in FTTx

The construction of optical access networks is one of key issues to provide new broad-band services and emulation of legacy services. Passive optical network (PON) technologies realize sophisticated and economical optical access networks for these purposes. This paper summarizes requirements and technical and marketing trends for optical access networks. It also presents advantages of networking by PON technologies for optical access networks. Moreover, it clarifies issues to install and operate PON base optical access networks and proposes solutions for these issues.     

Trends in U.S. Broad-Band Fiber Optic Transmission Systems

Fiber optic media are rapidly penetrating the telecommunications network. They are used as undersea and terrestial trunk lines, central-office loops, optical data links, and will eventually be included within the distribution plant which connects directly into individual premises. The rapid implementation of lightwave systems is occurring because the high bandwidths and low losses of optical fibers enable broad-band communication services to be provided between widely spaced repeaters and also allows users to upgrade currently installed systems to meet future needs. This paper will describe current applications and show how future trends will depend upon the continuing evolution of lightwave components and optical fiber designs.     

有线与无线技术结合的接入网

通信市场目前正面临着急剧的变化，利用被称作接入网的有线和无线技术的用户接入设备也相应问世，富士通过在局用交换机ＦＥＴＥＸ－１５０及光接入网传输设备中采用了国际标准规格的Ｖ５接口，以推进网络的开放和灵活适应高度复杂化的通信网，另外，为迎接终将到来的多媒体时代，富士通的ＡＴＭ／ＶＯＤ等宽带业务用接入网系统的开发也正在进行。     

Ethernet passive optical network (EPON): building a next-generationoptical access network

This article describes Ethernet passive optical networks, an emerging local subscriber access architecture that combines low-cost point-to-multipoint fiber infrastructure with Ethernet. EPONs are designed to carry Ethernet frames at standard Ethernet rates. An EPON uses a single trunk fiber that extends from a central office to a passive optical splitter, which then fans out to multiple optical drop fibers connected to subscriber nodes. Other than the end terminating equipment, no component in the network requires electrical power, hence the term passive. Local carriers have long been interested in passive optical networks for the benefits they offer: minimal fiber infrastructure and no powering requirement in the outside plant. With Ethernet now emerging as the protocol of choice for carrying IP traffic in metro and access networks, EPON has emerged as a potential optimized architecture for fiber to the building and fiber to the home