A broadband switching experiment

A broadband switching experiment was presented at the ISS'87 and Telecom'87 conferences in Phoenix, Arizona, and Geneva, Switzerland, respectively and at the March 1988 Fair in Hanover, West Germany. This experiment was significant in that it illustrated techniques for switching broadband signals with a wide range of frequencies, formats and ultimate purposes. In particular, simultaneous switching (within the same switch fabric) of 30 MHz PFM, 45 Mb/s PCM, and 140 Mb/s PCM was demonstrated. These signals carried full-motion, full-colour NTSC video for desk-to-desk video teleconferencing, off-the-air broadcast video programming, and surveillance camera video. They also carried RGB video, digitized stored video images, and computer-computer communications. Software features afforded a friendly human interface, allowing multiple, flexible service capabilities. Further, the experimental system, when deployed in Phoenix, demonstrated control of its capabilities via a narrowband ISDN link to an optically remoted 5ESS® switch module one km distant, which homed on a 5ESS host switch about 32 km further away. The technologies employed in the switch and the surrounding equipment are detailed, and the significance of this experiment relative to the broadband ISDN (BISDN) thinking is discussed.     

Video and image applications on narrowband and broadband isdn

Two major ISDN applications which will undoubtedly affect world-wide telecommunications in the coming decade are discussed. They are: (1) video transmission and (2) image transmission. Brief reviews of videophone chronicle and the current video coding technologies are presented. The application of videophones using p × 64 (CCITT coding algorithm up to 1·5 Mb/s) and the DCT (discrete cosine transform) algorithm for narrowband ISDN are discussed. Broadcast TV quality DS3-45 MB/s video codecs are also briefly discussed as a probable videophone system in the broadband ISDN era. The explosive growth of facsimile services is reviewed, and the progress of image coding technologies and their standards are covered. The prospects of high resolution image transfer systems with ISDN are addressed.     

The DTX-240D digital circuit multiplication system

This paper describes the DTX-240D digital circuit multiplication system (DCMS) offered by ECI Telecom. It will accept up to 240 × 64 kb/s trunks carrying either 64 kb/s voice, voice band analogue non-speech signals, or digital data for transmission over a 2·048 Mb/s digital link. Over 1000 are currently ‘on-line’ and carrying traffic. The system comprises a pair of terminals, one on each side of the interterminal digital link (bearer). It will normally operate in the network at a concentration ratio of 5:1, in which case 150 × 64 kb/s trunks, carrying voice, voice band data or digital data can be concentrated into one 2·048 Mb/s bearer. The users are able to increase the number of trunks up to 240 per 2·048 Mb/s bearer, when time zone differences cause a spread of busy-hour traffic carried on a single system. Each terminal will normally be located at an international switching centre (ISC) but may also be located at an earth-station. The system uses a DSI (digital speech interpolation) stage providing a 2·5:1 multiplication, followed by an additional 2:1 multiplication by means of ADPCM (adaptive differential pulse code modulation). In addition, the VBR (variable bit rate) technique is used to prevent clipping, due to overload congestion. The system can also be used with 1·544 Mb/s digital bit streams (trunk side or bearer).     

Shared access packet transmission systems for compressed digitalvideo

The problem of designing shared access packet-transport-based transmission systems for compressed video signals is studied. The feasibility of using conventional link-level and transport-level protocol services to transmit compressed video is examined by focusing on two practically important scenarios for compressed video transmission: (1) multipoint-to-multipoint video transmission using a 200 Mb/s implicit token passing (ITP) fiber-optic local area network (LAN); and (2) point-to-multipoint broadcast video distribution using a 90 Mb/s packet time-division multiplexing (packet-TDM) direct-broadcast satellite channel. To evaluate the performance of such shared-access broadband packet video systems accurate simulation models were developed that were driven by realistic `broadcast quality' compressed video sources for the ITP-LAN and packet-TDM systems. The models were used to determine design tradeoffs between channel throughput, video quality (measured by clipping probability), and the transport-level and media-access-level protocol features and parameters implemented in the packet video network interface unit     

Architecture for delivery of broadband services to the residence

This paper presents a technology and architecture perspective on the cost of evolving today's copper access network, optimized for POTS, to a fibre access network providing both narrowband and broadband services. Architectures are assessed using application studies based on cost models for actual routes in North America. This study identifies three architectures as serious candidates (i.e. close to copper in cost) for providing POTS service in 1992: the double star, the active pedestal and the star-bus. The active pedestal and the star-bus architectures were similar in first costs and were the least expensive, costing between 5 and 15 per cent more than the copper reference depending on the number of subscribers subtending a given optical fibre. The double star is 20 per cent more expensive than the copper reference. All three architectures are potentially attractive for broadband service upgrade depending on the bandwidth required per subscriber. The star-bus is most bandwidth sensitive. Moderate video bandwidths, nominally 150 Mb/s/subscriber, favour the active pedestal architecture. Conversely, service environments requiring much greater than 150 Mb/s/subscriber favour the double star architecture.     

A high-speed four-channel subscriber fibre-optic link for broadband networks

This paper describes the performance of a 560 Mb/s digital fibre-optic link designed specifically for possible use in a broadband integrated services digital network (BISDN) environment. Four 140 Mb/s non-return-to-zero (NRZ) channels are time division multiplexed using a bit-by-bit multiplexing strategy and transmitted using potentially low cost 1.3 μm EE-LED and laser sources. A 10^?9 bit error rate with a power level of -34 dBm was achieved for each independent channel over a distance of 10 km.     

World-wide standardization of broadband ISDN

A growing market demand for high-performance voice, data, image and video networks, coupled with advances in high-speed technologies has heightened interest in broadband ISDN (BISDN) throughout the world. Network providers, equipment manufacturers and standards bodies are working jointly to accelerate the definition of BISDN interfaces in anticipation of emerging market opportunities. BISDN is being designed as the foundation upon which to implement very flexible, high-bandwidth, high-performance networks. A multiplexing concept called asynchronous transfer mode (ATM), which can offer bandwidth on demand at rates exceeding 150 Mb/s, high-speed packet switching, and an efficient protocol which adapts existing information streams into the ATM format are key attributes of the emerging BISDN network standards. This paper reviews the motivations behind BISDN, explains its key attributes and challenges and discusses possible strategies for evolving today's network toward BISDN.     

CATV网渐进升级为全业务接入网的技术

本文就ＣＡＴＶ网向宽带全业务网升级的策略和技术进行了讨论。首称要将现有ＣＡＴＶ网改造为双向传输网。在此基础上,建成ＣＡＴＶ广播网和计算机网并行的网络。在计算机网中,应用Ｃａｂｌｅ ｍｏｄｅｍ实现数据双向传播,或在ＣＡＴＶ网中应用暂时富裕的光纤构成独立计算机网。     

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.     

走向宽带化的VSAT卫星通信

受数据音频视频广播、计算机卫星宽带交互接入和音视频会议等业务的推动,VSAT卫星通信网向宽带业务发展巳成为必然趋势。分别对应以上业务的VSAT卫星通信网也日益趋于融合成一个统一的宽带VSAT通信网。发展宽带VSAT通信网的关键技术涉及到宽带数据广播、宽带多址接入、卫星通信规程、网络综合管理和宽带虚拟子网等。     

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     

Broadband ISDN technology and architecture

Broadband integrated services digital network (BISDN) network architecture for local public serving areas is described. It is designed to offer end-users access to bandwidths up to 155 Mb/s. The BISDN protocols described support the simultaneous delivery of voice, data, image, and video services to business and residential customers. The objective of the broadband architecture described is to suggest designs that can evolve from today's base of narrowband equipment toward BISDN. It supports the use of fiber for narrowband services, in order to ensure that a broadband infrastructure is in place to serve as a platform from which broadband services can be offered. It also uses optional broadband modules on existing narrowband systems to facilitate evolutionary growth of broadband services and recognizes the metropolitan area network (MAN) protocol defined by IEEE 802.6 as a possible early implementation of BISDN     

A High-Power Low-Distortion GaAs HBT Power Amplifier for Mobile Terminals Used in Broadband Wireless Applications

This paper describes technologies of miniaturized high-power low-distortion GaAs HBT power amplifiers with a low-voltage operation for mobile terminals used in 5-6 GHz broadband wireless applications. In conjunction with diode-based linearizing techniques, wideband matching network techniques including trap circuits for second harmonics allow us to obtain a compact broadband power amplifier module with harmonic filtering, achieving the high linear output power at a low supply voltage together with the low distortion and the low second-harmonic spurious outputs in a wide frequency range. The fabricated power amplifier exhibited linear output power levels of 21 and 22 dBm at EVM values of 2.0 and 3.0%, respectively, measured with 54 Mb/s 64-QAM-OFDM signals at a supply voltage of 3.3 V in a frequency range of 5-6 GHz. Second harmonic spurious outputs below -35 dBc were also attained.     

Demonstration of a Bidirectional 80-km-Reach DWDM-PON With 8-Gb/s Capacity

A bidirectional 80-km-reach 64-channel dense wavelength-division-multiplexing passive optical network with 50-GHz channel spacing based on wavelength-locked Fabry-Peacuterot laser diodes is demonstrated. By changing the position of the broadband light source (BLS) for the upstream channels to the remote node, both the need for a high-power BLS and the power penalties induced by backscattering are overcome. Packet-loss-free transmission is obtained, guaranteeing 125 Mb/s per channel (8-Gb/s capacity in a single direction) without the support of an optical amplifier     

Fiber-to-the-home services based on wavelength-division-multiplexing passive optical network

It is anticipated that more than 75 Mb/s per subscriber is required for the convergence service such as triple-play service (TPS). Among several types of high-speed access network technologies, wavelength-division-multiplexing passive optical network (WDM-PON) is the most favorable for the required bandwidth in the near future. Furthermore, WDM technologies, such as athermal arrayed-waveguide grating (AWG) and low-cost light source, have matured enough to be applied in the access network. In this paper, the authors propose and implement a WDM-PON system as a platform for TPS. The system employs an amplified spontaneous emission (ASE)-injected Fabry-Pe/spl acute/rot laser diode scheme. It has 32 channels of 125 Mb/s and adopts Ethernet as Layer 2. Multicast and virtual local area network features are used for the integration of services such as Internet protocol high-definition broadcast, voice-over Internet protocol, video on demand, and video telephone. The services were demonstrated using the WDM-PON system.     

An expandable time-division circuit switching LSI and networkarchitecture for broadband ISDN

A broadband network architecture is proposed that integrates multimedia services, such as data, video, and telephony information, using 52-Mb/s based STM-paths at the user network interface (UNI). The user can access any new service via the STM-based access network via either synchronous transfer mode (STM) switching or asynchronous transfer mode (ATM) switching. STM circuit switching supports long duration, constant bandwidth data transfer services such as video and high-definition television (HDTV) distribution and will also be used for the crossconnect system. Circuit switching can provide transparent transmission during long connection periods. This paper also proposes an expandable time-division switch architecture, an expandable time-division switching LSI, and an expandable switching module for small to large size system applications. The proposed time-division switching LSI, module, and system handle 52-Mb/s bearer signals and have throughputs of 2.4 Gb/s, 10 Gb/s, and 40 Gb/s, respectively. The time-division switch realizes video distribution with 1:n connections. Finally, a local switching node that features an expandable 52-Mb/s time-division circuit switching network is shown for multimedia access networking     

The Washington University broadband terminal

The requirements of broadband asynchronous transfer mode (ATM) audio/video (A/V) transmission systems and the approach used to implement the Washington University broadband terminal (BBT) are discussed. The goal of the project was the development of a system with real-time audio and video capability that fully utilized the capability of the Washington University ATM network. The BBT transmits standard NTSC color video and audio over the local ATM network, using a novel approach. A composite analog A/V signal is digitized at three times the video color burst frequency at the transmitter; at the receiver, a unique frame buffer scheme is used to regenerate the transmitted audio and video signals     

Distributed source control: a network access control for integratedbroadband packet networks

The authors propose a congestion control strategy called distributed source control (DSC), designed to address the integration of diverse traffic types in broadband packet networks. DSC is a rate-based network access control implemented at the asynchronous transfer mode (ATM) layer as a feedforward control, in conjunction with an adaptive end-to-end control between network edges. The authors examine the performance of high-speed data traffic such as large file transfers, still images, and document retrievals. The authors study DSC's integrability with real-time traffic such as voice and video. With the help of a simulation model of a broadband packet network (150 Mb/s), the authors quantify the improvement in network performance due to DSC. An analytic model for an access node under DSC is developed, and guidelines for sizing of buffers in the switch and for choosing the end-to-end window size are provided     

基于IPTV终端的视频监控系统的设计

IPTV视频监控技术是未来三网融合最有特色的应用技术之一,同时家庭视频监控正成为监控行业的一个新领域。文中给出了一种基于IPTV终端的家庭视频监控系统的设计方案,该方案是基于C／S模式的构架,视频数据的压缩编码采用达芬奇技术实现,为了保证传输的质量,网络传输采用了RTP协议和基于丢包率的拥塞控制方法。最后,在2Mb／s的ADSL宽带接入网络下进行测试,结果表明用户可以随时随地登陆到家庭视频监控系统中查看家庭情况。系统的时延控制在0．3S之内。     

福建省宽带多媒体通信网集成方案

本文主要介绍福建省宽带多媒体通信网络拓扑结构和业务集成方案。宽带多媒体通信网包括ＡＤＳＬ接入网、ＡＴＭ宽带交换网,应用服务器。目前在福建省宽带多媒体通信网上承载的业务有视频点播和宽带ＷＥＢ浏览、１６９／１６３的传输和路由骨干,帧中继,交互式视频业务（如电视会议,远程医疗）等。