The regulatory challenge of broadband technologies

The evolution of broadband technologies is described, focusing on fiber loops and broadband switching. Broadband service opportunities are briefly examined. It is contended that while most countries accept novel communications technology and rapidly integrate their benefits into public telecommunication networks, the micromanagement style prevalent in the USA precludes the provision of many services that will be possible through breakthroughs in broadband technology. To support this argument, the plans followed by Japan, France, West Germany, and the United Kingdom are presented and contrasted with the situation in the USA     

两种FTTH宽带接入实现技术的对比研究

近几年互联网新业务的发展对带宽的要求越来越高,基于PON技术的宽带接入技术发展越来越迅速,FTTH产业又进入了新一轮的蓬勃发展期,光纤网络正在从百兆到户向千兆接入迈进。在FTTH项目建设过程中,采用哪种宽带接入实现技术是运营商们要去考虑的一个问题。     

A comparison of optical buffering technologies

We describe the practical and fundamental limitations of the more prominent optical buffering approaches. The architectural implementation and needs of an optical packet switch are used as a foundation for the study. We also present initial results for a buffered, all-optical, 40 Gb/s packet switch.     

A comparison of wireless local loop with competing accesstechnologies

It is important to remember that wireless local loop (WLL) is in competition with other fixed access technologies. There are a number of different access techniques which are emerging, including techniques which enhance basic copper cables, such as ISDN and xDSL, new forms of cable, such as coax and fibre, video distribution systems and alternative means of delivering voice and data, such as mobile radio and digital television broadcasting. All these are competing with wireless local loop to provide a convergent service whereby voice, data and television are provided through the same access medium. This paper provides some details about each of the different access technologies, makes predictions about their future success, and examines the likely future of WLL in tomorrow's access technology market-place     

Economics of residential broadband access network technologies andstrategies

This article presents a techno-economic assessment of the evolution of the access network segment toward broadband data service delivery, including in-depth sensitivity analysis of key issues faced by the infrastructure providers. The line costs and payback periods of different access network technologies for infrastructure broadband upgrades are examined, subject to variation in parameters like the existing infrastructure, the broadband take rate, civil work costs, revenues, and rollout year. The work should enable establishment of guidelines for broadband infrastructure upgrade strategies     

下一代家庭宽带互联技术简述

本文分析家庭互联的现状和主要宽带互联技术,总结下一代家庭宽带互联技术的融合发展趋势。     

Alternative technologies and delivery systems for broadband ISDNaccess

Switched on-demand video is expected to become a major consumer of bandwidth. Two-way video offers televisting, tele-education, and telecommuting services, which together could represent a further substantial bandwidth demand. High-speed data services to provide the fiber distributed data interface (FDDI) between locations, or even operate a computer-aided design (CAD) terminal remotely from its local area network (LAN), are likely new applications for broadband integrated services digital networks (B-ISDN). The video quality evolution and digital modulation techniques that are making broadband digital delivery of TV signals possible are reviewed. Cable TV B-ISDN delivery, short twisted pair B-ISDN delivery, and TV broadcast digital delivery are discussed     

A throughput/delay comparison: narrowband versus broadband wirelessLAN's

A communication system in which some large number of portable notebook computers access a centrally-located base station by means of a shared, high-speed, radio-based LAN is considered. The delay and throughput performances of two alternative approaches are compared: one high-speed channel shared by all portable remotes versus several moderate-speed channels, each shared by a subset of portable units. In both cases, access to the intended services is impeded by contention for the medium and queueing for some shared server (processor or database). Both systems are modeled as closed-queueing networks, and expressions for system throughput and average request delay are obtained. Numerical results show that over a wide range of parameters, the system containing one high-speed channel outperforms the system containing several parallel medium-speed channels by less than 10%     

Mobile agent and CORBA technologies in the broadband intelligentnetwork

This article presents an IN architecture that is based on distributed object and mobile agent technologies. It deviates from traditional IN in two prominent ways: first, by substituting message-based protocols with a CORBA distributed processing environment. The new communications infrastructure not only serves to convey IN flows, but also functions as a potent unifying location-transparent layer. Second, the new architecture makes heavy use of mobile agent technology. Service logic programs are implemented as mobile agents, and are thus not constrained to control the switch's operations remotely from a central location. Instead, they can migrate and control its operations locally. The infrastructure elements of the architecture exploit this ability of service logic programs by cloning them and dragging their clones to the appropriate locations in response to excess processing or signaling load. The architecture is in this way self-balancing, in contrast to the centralized nature of traditional IN. A prototype implementation is presented along with a service creation framework that enables the IN service designer to disregard environment-related issues and concentrate on the IN logic of the services per se     

Circuit-level comparison of STATCOM technologies

This paper performs a comprehensive circuit-level evaluation of four modern STATCOM systems, namely true-48-pulse and quasi-48-pulse STATCOMs, cascade multilevel and binary multilevel inverters. The comparison is based on a number of factors including circuit topology, harmonic distortion, system losses, GTO quantities, their specific applications, and other considerations. The theoretical results are verified by simulation with the use of MATLAB-Simulink Power System Blockset.     

The future generations of mobile communications based on broadband access technologies

The forthcoming mobile communication systems are expected to provide a wide variety of services, from high-quality voice to high-definition videos, through high data rate wireless channels anywhere in the world. The high data rate requires broad frequency bands, and sufficient broadband can be achieved in higher frequency bands such as microwave, Ka-band, and millimeter-wave. Broadband wireless channels have to be connected to broadband fixed networks such as the Internet and local area networks. The future-generation systems will include not only cellular phones, but also many new types of communication systems such as broadband wireless access systems, millimeter-wave LANs, intelligent transport systems, and high altitude stratospheric platform station systems. Key to the future generations of mobile communications are multimedia communications, wireless access to broadband fixed networks, and seamless roaming among different systems. This article discusses future-generation mobile communication systems.     

海上无线宽带网络架构研究现状及相关技术展望

近年来,国家智慧海洋战略的实施对海上无线通信网络全方位覆盖、海上应急管理水平和信息服务能力等提出更高的要求。从部署海上无线宽带网络的实际需求出发,总结了海上无线宽带网络架构的国内外研究现状,概括了海上无线宽带技术的特点,最后展望了海上无线宽带网络技术的研究前景。在广阔的海洋上部署高速低成本的无线宽带网络定会为海洋产业的发展提供有力的通信保障和技术支持。     

加强频谱管理促进宽带无线技术健康发展

当前,宽带无线通信领域异常活跃,新技术层出不穷,应用范围不断拓展.对此,我国无线通信业界也投入了很大的关注.地面固定无线接入、LMDS、WLAN、蓝牙等无线接入和无线局域网技术纷纷被引进和开发,并已经找到或正在寻找适合中国国情和市场需求的业务模式.     

A comparison of linear handset power amplifiers in different bipolar technologies

This work evaluates four linear power amplifiers for wireless handset applications that were fabricated (or simulated) in four different bipolar technologies. The four bipolar technologies are currently competing to become, or remain as, the preferred bipolar technology for the commercial development of power amplifier modules. The four technologies are GaAs HBT, Si BJT, SiGe HBT, and InP HBT. The purpose of this work is to evaluate the performance of power amplifiers in each of these competing technologies in terms of typical linear handset PA requirements (i.e., P/sub OUT/, ACPR, PAE, P/sub GAIN/, and ruggedness).     

A broadband utopia [fast broadband connectivity]

The Utah Telecommunication Open Infrastructure Agency (Utopia) promises to deliver to each of its 3,000 subscribers high-speed Internet access, telephony and television programming through a fiber-optic cable at data rates that reach 30 megabits per second. Encompassing 14 cities in the northeastern Utah, the optical-fiber broadband network is expected to soon reach speeds of 50 and even 100 Mb/s. Because Utopia sends TV programming as Internet packets, it puts a huge reservoir of bandwidth at the disposal of its providers. In addition to its dedicated bandwidth connections, Utopia relies on the Ethernet standard to carry Internet protocol data packets all the way from the central office to the individual subscriber without changing the format, greatly simplifying the network.