电话、电脑和电力的"三网合一"概念与实现技术(一)——"三网合一"的技术需求和电力线载波的新发展

根据人类对日益增大的统一信息的需求,提出了电话、电脑和电力"三网合一"的概念,并结合国内外电力线通信的发展和电力、信息融合的趋势,叙述了电力线通信的历史及在电力系统中的应用现状,详细介绍了国外电力线通信技术研究的最新突破,探讨了以高速率电力线通信实现"三网合一"的可行性.     

电话、电脑和电力的“三网合一”概念与实现技术(三)——“三网合一”的应用研究步骤及展望

根据中国的实际情况 ,提出了实现“三网合一”的研究步骤 ,即 :优先发展利用电力线载波的配电自动化通信技术、开发电力市场用户侧交易结算的电力信息网络 ,初步实现“三网合一”。最后结合国外的最新技术报道 ,对电力线通信的前景进行了展望     

电话,电脑和电力的“三网合一”概念与实现技术（一）：“三网合一”的技术需要

根据人类对日益增大的统一信息的需求,提出了电话、电脑和电力“三网合一”的概念,并结合国内外电力线通信的发展和电力、信息融合的趋势,叙述了电力线通信的历史及在电力系统中的应用现状,详细介绍了国外电力线通信技术研究的最新突破,探讨了以高速率电力线通信实现“三网合一”的可行性。     

电话、电脑和电力的“三网合一”概念与实现技术(一)——“三网合一”的技术需求和电力线载波的新发展

根据人类对日益增大的统一信息的需求 ,提出了电话、电脑和电力“三网合一”的概念 ,并结合国内外电力线通信的发展和电力、信息融合的趋势 ,叙述了电力线通信的历史及在电力系统中的应用现状 ,详细介绍了国外电力线通信技术研究的最新突破 ,探讨了以高速率电力线通信实现“三网合一”的可行性。     

电话、电脑和电力的"三网合一"概念与实现技术(二)——"三网合一"中需要解决的技术问题

在文(一)的基础上提出了实现电话、电脑和电力"三网合一"所要解决的技术问题和相关的解决思路.即:要提高通信速率必须拓展电力线的通信带宽;要提高抗干扰能力必须研制高效的信息与电力线间的耦合器件及采用新的调制、编码技术;要组成可靠、高效的信息接入网,必须解决高频信号翻越变压器和跨越断路器断口的问题以及与电话网、计算机网络接口与组网方式问题.     

电话、电脑和电力的“三网合一”概念与实现技术(二)——“三网合一”中需要解决的技术问题

在文 (一 )的基础上提出了实现电话、电脑和电力“三网合一”所要解决的技术问题和相关的解决思路。即 :要提高通信速率必须拓展电力线的通信带宽 ;要提高抗干扰能力必须研制高效的信息与电力线间的耦合器件及采用新的调制、编码技术 ;要组成可靠、高效的信息接入网 ,必须解决高频信号翻越变压器和跨越断路器断口的问题以及与电话网、计算机网络接口与组网方式问题。     

“四网合一”对决电力线上网

1“四网合一”现状所谓“四网合一”并不是指电力线上网,而是电力、电信、电视和因特网四网合一宽带接入传输网。2004年2月1日,全球第一个“四网合一”光纤到户FTTH(FibertotheHome)示范网在胡北省公安县供电公司物资分公司投入运行;4月下旬,武汉光电国家实验室“四网合一”光纤到户示范网也投入运行。据悉,这两个“四网合一”示范网同时采用了由华中科技大学刘德明教授主持的国家863计划通信主题重大项目———“基于千兆以太网的宽带无源光网络系统”和“四网合一”发明专利,实现了电信、电视、电力和计算机网络的“四网融合、一线入户…     

小区通信改造中“三网合一”的应用

<正>加快宽带发展,推动技术换代和网络改造,实现光纤到户,首要的就是"三网合一"。现从"三网合一"背景、基本概念、设计思路、设计方案、方案实施等方面阐述"三网合一"技术在小区通信改造中的应用。1"三网合一"背景随着科技发展,我国成为互联网用户数量最多的国家,但网速慢一直困扰着很多用户。近年来,云计算、物联网等新兴技术的发展也增加了互联网流量,对网络宽带提出了更高的要求。但是,在光     

“三网合一”应用初探

着重介绍在华中地区进行的“三网合一”组网实验情况,并对该技术在通信系统的应用前景进行了展望。     

应用"三网合一"技术建设广域网

介绍了采用“三网合一”技术建设的广域网及其在华电集团的应用,包括广域网的总体结构设计、基本配置及各种功能的实现。     

Decongestants for clogged networks

Interconnection networks are a key element in a wide variety of systems: massive parallel processors, local and system area networks, clusters of PCs and workstations, and Internet Protocol routers. They are essential to high performance in the form of high-bandwidth communications, with low latency, "quality of service" (guaranteed service levels), efficient switching, and flexibility of network topology, as embodied in Myrinet, InfiniBand, Quadrics, Advanced Switching, and similar interconnects. But, despite all the advances that modem interconnects offer, congestion is a growing problem as "lossless" interconnection networksrdquo those that do not allow data packets to be discarded" come to the fore.     

Topological conditions for the solvability of linear active networks

The solvability problem of a linear active network is approached from a purely topological point of view using the two-graph method. It can be said that a topological condition for the solvability is the existence of a common tree of the voltage and current graphs. A few conditions for the existence of a common tree are derived. If there exists no common tree, subgraphs which cause the nonexistence can be distinguished, and a partition of two-graphs can be introduced. The partition has similar properties to the principal partition of a graph or the canonical form of a bipartite graph, and a structure of two-graphs represented by a partial ordering of sets of edges can be defined. An algorithm to find the partition and a common tree, if one exists, or if no common tree exists, a tree of one of the graphs which has as many common edges as possible with a tree of the other graph, is given. The decomposition of the coefficient matrix accompanying the structure is discussed, and algorithms to determine the decomposition is given.     

Multiport approach for the analysis of microwave non-linear networks

The state and output equations of the overall networks are derived from the state and output equations of individual multiports and knowledge of the interconnections between them. A generalized lumped-distributed L/D multiport is described by its associated state, output and non-linear equations in the time domain. Any network can be considered as composed of a set of multiports and independent sources. These equations have been incorporated into a computer-aided procedure for the analysis of L/D networks. The procedure can be used for the simulation of any non-linear microwave circuit and offers the facility of developing a multiport equivalent circuit for any linear or non-linear device or subcircuit. Several examples are successfully analysed using the developed general program.     

Topological conditions for the unique solvability of linear time-invariant and time-varying networks

The problem of knowing whether the non-unique solvability depends on the particular values of the components or on their topological interconnections is studied for linear networks with arbitrary, time-invariant as well as time-varying n-ports. Within every network, the topological notions of its sockets and of their independence are introduced. Networks with independent sockets are shown-at least when there are no relations among the non-zero coefficients, nor repetitions of the same coefficient are allowed, i.e. under suitable generality assumptions-to be uniquely solvable. Networks with dependent sockets are shown to be never uniquely solvable. Polynomially bounded algorithms, requiring only integer arithmetic, to test independence are available. When independence fails, a topological configuration of components which shows fewer topologically independent variables than equations, is proved to exist.     

未来网络下的移动MPLS连接

主要阐述MPLS如何被应用到未来网络的移动连接点中。随着在MPLS中应用DiffServ，QoS容易得到保证，采用分层技术，在切换中质量的损失能够被减少，用户能获得实时的应用。要使得MPLS技术最终应用到骨干网中，对QoS、安全性以及DiffServ等问题的进一步研究和完善是必不可少的。     

Self-organization of neural networks for clustering

Generally, there are many methods of categorizing unknown data in statistics. In many of these methods, we need sample data to determine the borders of the groups to which these data belong. Neural networks are also usable to classify unknown data. In the learning process of neural networks, we must prepare so-called teaching signals, that is, sample data. In this paper, we propose an empirical scheme to organize neural networks for clustering unknown data which belong to two groups. In our scheme, a neural network that satisfies an evaluation function without teaching signals is organized. This evaluation function is determined by a histogram of outputs of the neural network. Generally, neural networks map the input data distribution to the output distribution. Maximizing the evaluation function means separating these two output distributions from each other. As an organizing mechanism, the genetic algorithm is used because of its ability to converge to a global maximum. Some numerical results are presented to confirm the feasibility of the scheme. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 121(1): 51–59, 1997     

Harmonic analysis for power networks

The problem of harmonic penetration in power networks is of increasing importance. One method of estimating the penetration is to measure the harmonic voltages at points of common coupling and at selected locations in the network. This paper presents a method of solution which predicts harmonic penetration using a digital computer. The method of calculation is based upon the concept of conventional load flow. In conventional load flow only the fundamental frequency component of the voltage is calculated. In the proposed method this can be extended to any desired frequency range and these voltages at different frequencies are calculated simultaneously. The major obstacles to such an approach would be the establishing of a mathematical model and valid assumptions to ensure consistent convergence. The proposed method overcomes both of these obstacles. The method had been tried on a sample network with different starting points and with different loading conditions, and consistent convergence was obtained.     

Radios for next-generation wireless networks

Next-generation wireless networks will support a wide range of data rates over several frequency bands and require adaptive and programmable system resources. Radio transceivers used in these wireless networks will incorporate self-calibration and full programmability to support their high performance and adaptivity. Low power designs at the circuit architectural, and overall system levels will enable longer battery life for portable devices. Many additional challenges exist in implementing high data rate programmable orthogonal frequency division multiplexing (OFDM) multiple-input/multiple-output (MIMO) radio transceivers that cover different frequency bands, maintain low current consumption, and are low cost. This article is an examination of the challenges in implementing high data rate programmable orthogonal frequency division multiplexing multiple-input/multiple-output radio transceivers that cover different frequency bands, maintain low current consumption, and are low cost.