Management of capacity and control in broadband ISDN

The trend towards integration of services onto a single network and the addition of accompanying control features has led to an increase in the complexity of functional signalling protocols. A continuing dramatic reduction in the cost of traffic-carrying capacity has meant that call control costs are becoming an increasingly significant component of the total network cost. In BISDN, the support of many diverse services may result in an excessive control cost. To avoid this potential problem, virtual paths may be used. Capacity may be reserved on virtual paths to simplify the set-up procedure for individual calls. One benefit of this approach is that the cost of establishing a virtual path is shared among all individual connections which subsequently use it. However, this reduced control cost comes at the expense of installing additional traffic carrying capacity. This paper describes techniques for the management of traffic carrying capacity and control mechanisms in BISDN and presents a cost-benefit analysis to determine policies for reserving capacity on virtual paths. Significant savings in the total BISDN cost can result from the use of virtual paths.     

Wide dynamic range parallel feedback transimpedance amplifier for 10 Gb/s optical links

This paper presents the design and implementation of a new wide dynamic range parallel feedback (PF) transimpedance amplifier (TIA) for 10 Gb/s optical links. The wide dynamic range is attributed to the novel TIA architecture employing both shunt-shunt and shunt-series feedback networks. The outstanding features of the TIA are wide dynamic range, high gain, low power consumption and design simplicity. A prototype implemented in a 0.5 μm SiGe BiCMOS technology and operating at −3.3 V power supply features an 18.4 dBm dynamic range with a BER less than 10⁻¹², an optical sensitivity of −16 dBm, optical overload of +2.4 dBm, a bandwidth of 8.27 GHz, a gain of 950 Ω and a power consumption of 189 mW. The new parallel feedback architecture offers improved overload and noise performance when compared to previously reported, state of the art, single feedback TIA designs and meets all the 10 Gigabit Ethernet and short-reach OC-192 SONET specifications. Ricardo Andres Aroca received the B.S. (Hons) degree in electrical engineering from the University of Windsor, Canada, and the M.S. degree from the University of Toronto, Canada, in 2001 and 2004, respectively. In 2000 he spent two 4 month internships with Nortel Networks in the Microelectronics Department. Mr. Aroca received the Natural Sciences and Engineering Research Counsel of Canada (NSERC) Postgraduate Scholarship award in 2002. He is currently working toward the Ph.D. degree at the University of Toronto where his research interests lie in the area of high-frequency integrated circuits for wireless and wireline communication systems. C. Andre T. Salama received the B.A.Sc. (Hons.) M.A.Sc. and Ph. D. degrees, all in Electrical Engineering, from the University of British Columbia in 1961, 1962 and 1966 respectively. From 1962 to 1963 he served as a Research Assistant at the University of California, Berkeley. From 1966 to 1967 he was employed at Bell Northern Research, Ottawa, as a Member of Scientific Staff working in the area of integrated circuit design. Since 1967 he has been on the staff of the Department of Electrical and Computer Engineering, University of Toronto where he held the J.M. Ham Chair in Microelectronics from 1987 to 1997. In 1992, he was appointed to his present position of University Professor for scholarly achievements and preeminence in the field of microelectronics. In 1989-90, he was awarded the ITAC/NSERC Research Fellowship in information technology. In 1994, he was awarded the Canada Council I.W. Killam Memorial Prize in Engineering for outstanding career contributions to the field of microelectronics. In 2000, he received the IEEE Millenium Medal. In 2003, he received the Outstanding Lifetime Achievement Award from the Canadian Semiconductor Technology Conference for seminal and outstanding contributions to semiconductor device research and promotion of Canadian University research in microelectronics. In 2004, he received the NSERC Lifetime Achievement Award of Research Excellence for outstanding and sustained contributions to the field of microelectronics and the Networks of Centres of Excellence (NCE) Recognition Award for research excellence and outstanding leadership.He was associate editor of the IEEE Transactions on Circuits and Systems in 1986–88 and a member of the International Electron Devices Meeting (IEDM) Technical Program Committeein 1980–82, 1987–89 and 1996–98. He was the chair of the Solid State Devices Subcommittee for IEDM in 1998 and was a member of the editorial board of Solid State Electronics from 1984 to 2002. He is presently a member of the editorial board of the Analog IC and Signal Processing Journal and the Technical Program Committee of the International Symposium on Power Semiconductor Devices and ICs (ISPSD) and the Technical ProgramCommittee of the International Symposium on Low Power Electronics and Design (ISLPED). He chaired the technical program committee of ISPSD in 1996 and was the general chair for the conference in 1999.Dr. Salama is the Scientific Director of Micronet, a network of centres of excellence focussing on microelectronics research and funded by the Canadian Government and Industry. He has published extensively in technical journals, is the holder of eleven patents and has served as a consultant to the semiconductor industry in Canada and the U.S. His research interests include the design and fabrication of semiconductor devices and integrated circuits with emphasis on deep submicron devices as well as circuits and systems for high speed, low power signal processing applications. Dr. Salama is a Fellow of the Institute of Electrical and Electronics Engineers, a Fellow of the Royal Society of Canada, a Fellow of the Canadian Academy of Engineering, a member of the Association of Professional Engineers of Ontario, the Electrochemical Society and the Innovation Management Association of Canada.     

天津本地ATM宽带业务试验网

概括地介绍了已建的天津本地ＡＴＭ宽带业务试验网的结构、特点，以及在网上进行有关技术、业务试验的情况和体会，认为通过该网积累了如何建设ＡＴＭ宽带网、如何用好ＡＴＭ宽带网、如何管理ＡＴＭ宽带网等方面丰富的经验。     

弱场等离子体中电子注的传输

本文导得了充等离子合格同波管漂移空间弱场条件下电子运动轨迹方程，详细阐述了α区和β区电子注的运动特点，并通过数值计算推得了电子运动形态为围绕平衡半径在α区和β区交替波浪式前进，波纹的周期和幅度与等离子全参数及电压和场强有关，研究结果还表明，利用填充等离子体的弱场空间可实现长短距离的电子注无磁场聚束传输。     

宽带匹配网络设计中的改进实频法

通过对传输功率增益TPG的进一步推导,引入了共轭匹配原理,提出了一种对实频法的改进算法,运用最小二乘法直接求取电阻折线各段的增量值,避免了对增量的最初选取,简化了计算。用改进实频法设计了一个短波天线宽带匹配网络,在简化算法的基础上取得了比较好的性能。     

On mechanical waves and Doppler shifts from moving boundaries

We investigate the propagation of infinitesimal harmonic mechanical waves emitted from a boundary with variable velocity and arriving at a stationary observer. In the classical Doppler effect, X_s(t)=vt is the location of the source with constant velocity v. In the present work, however, we consider a source co‐located with a moving boundary x=X_s(t), where X_s(t) can have an arbitrary functional form. For ‘slowly moving’ boundaries (i.e., ones for which the timescale set by the mechanical motion is large in comparison to the inverse of the frequency of the emitted wave), we present a multiple‐scale asymptotic analysis of the moving boundary problem for the linear wave equation. We obtain a closed‐form leading‐order (with respect to the latter small parameter) solution and show that the variable velocity of the boundary results not only in frequency modulation but also in amplitude modulation of the received signal. Consequently, our results extend the applicability of two basic tenets of the theory of a moving source on a stationary domain, specifically that (i) for non‐uniform boundary motion can be inserted in place of the constant velocity v in the classical Doppler formula and (ii) that the non‐uniform boundary motion introduces variability in the amplitude of the wave. The specific examples of decelerating and oscillatory boundary motion are worked out and illustrated. Copyright © 2017 John Wiley & Sons, Ltd.     

浅析新格局背景下的增值电信企业生存之道

日前,工信部发布《中国(上海)自由贸易试验区外商投资经营增值电信业务试点管理办法》,不仅新增开放了四项业务并提高开放业务的外资最高持股比例,还将审批权限由工信部下放到上海市通信管理局,把审批期限大幅缩短至两个月。此次在上海自贸区试点开放的增值电信业务,力度非常大,全部8项增值电信业务中有7项在这里进行了开放试点。4月30日,经国务院批准,财政部和国家税务总局印发《关于将电信业纳入营业税改征增值税试点的通知》,明确从2014年6月1日起,将电信业纳入营改增试点范围,实行差异化税率,基础电信服务和增值电信服务分别适用11%和6%的税率,为境外单位提供电信业服务免征增值税。在如此鼓励国际化竞争的新格局背景下,国内的增值电信服务企业应如何应对政策及市场的机遇与挑战。     

宽带用户行为分析与探究

宽带网络发展到一定的阶段,宽带用户的行为将对网络产生一定的影响,为保障网络健康高效的发展,我们不仅要关心网络运行质量,还要关心用户行为,关注网络流量。本文从用户接入控制,非法接入监控,VOIP监控,P2P监控四个方面进行阐述。     

TD-LTE RAN承载技术方案分析

通过分析TD-LTE RAN承载需求,结合中国移动的TD网络建设现状,对中国移动的TD-LTE RAN承载技术方案进行描述和分析对比。     

宽带雷达中频回波长脉冲压缩采样重构中的分段重叠处理及其机理分析

宽带雷达中频回波在频域上稀疏。根据压缩感知理论,可对其进行压缩采样并从压缩采样结果中以很高的概率重构出原信号。中频回波压缩采样的重构需要的矩阵尺寸由中频回波的长度决定。在长脉冲情况下,重构所需的矩阵尺寸大,占用内存资源过多,处理速度慢。针对此问题,论文将分段重叠处理引入重构过程。论文首先详细给出了引入分段重叠处理之后的重构方法,接着通过严格数学推导,证明了频谱泄漏与局部时域序列的关系具有如下特点:远离谱峰的谱值受时域序列两端的影响要强于靠近谱峰的谱值,利用该特点说明了分段重叠处理抑制误差的机理。实测数据实验表明了分段重叠处理在重构质量上优于分段不重叠处理,在对存储资源的要求上远低于不分段处理。