定西市DTMB农村网络覆盖工程建设

针对定西市地面数字广播电视农村网络覆盖工程建设进行了介绍,项目建成后有效扩大了自办节目覆盖,使市、县电视节目在所辖地区的覆盖率由原来的不及20％上升为70％以上.对总体技术规划、项目实施细则及项目实施效果进行了说明.项目实施有效提升了城乡广播电视公共服务均等化服务水平.     

Control protocol and its performance analysis for distributed ATMvirtual path self-healing network

A restorable network comprised of a mesh of ATM virtual paths (AVPs) is expected to be superior to distributed SONET digital cross-connect self-healing networks in terms of restoration time. The paper presents a reliable protocol and evaluation of its performance for control information transfer in distributed AVP self-healing networks. Two error-recovery technologies for the data-link level (selective retransmission and go-back-N) in AVP networks are reviewed, and a model for evaluating the delay of the go-back-N method that has been used in existing terrestrial systems is derived analytically. The proposed analytic model is combined with a self-healing simulator for AVP mesh networks to evaluate the restoration time characteristics. Case study results for the worst-case scenario show that the total restoration time, including link-by-link error control for self-healing control messages, is expected to be less than 2 s, which is the time objective for complete restoration for a metropolitan LATA network. The results also show that the estimated average delay penalty for adding the link-by-link error recovery process is 7.5 ms for complete service restoration     

Architectures for ATM network survivability

This article surveys the restoration architectures for asynchronous transfer mode (ATM) network survivability that have been actively studied in this decade. Network reliability is critical for recent and future networks that will advance the information era. Moreover, it is one of the biggest factors in designing and managing networks. Since the early telecom network era, many restoration systems have been developed for plesiochronous digital hierarchy (PDH), synchronous digital hierarchy (SDH), synchronous optical network (SONET), leased lines and so on; and they were surveyed in many papers and books. This article focuses on new restoration techniques for ATM networks. First, the requirement studies are introduced. This includes the scant results published on the influence of failure and the state of failure analysis. Next, restoration schemes are categorized and briefly introduced. Examples include centralized control, automatic protection switch (APS), self-healing ring (SHR), self-healing network (SHN) and failure resistant virtual path (FRVP). In order to achieve adequate restoration probability with minimum cost, a network design scheme is necessary; thus, network design issues are introduced. Finally, this article focuses on the issues, future work, and problems that remain to be solved.     

超大规模城市政务领域灾备中心网络建设研究

随着国内政务信息系统上云和信息化的推进,我国超大规模城市政务灾备中心建设也不断向云化数据中心形式演化。城市数字治理以数字化转型为基础推动,并以“一网通办,一网统管”为核心目标。一个好的城市级政务信息系统灾难备份体系的规划和建设,对于保证公共数据安全和政务业务连续性起着至关重要的作用。探讨了数据集中程度高、部门机构多的超大规模城市灾备中心网络建设的特点、模型、架构和关键点。     

Restoration message transfer mechanism and restorationcharacteristics of double-search self-healing ATM network

The self-healing network is particularly interesting with regard to ATM networks, because the restoration time can be shortened by using the advantages of the ATM network. This paper studies a self-healing ATM network based on virtual path (VP) protection switching. First, a novel self-healing algorithm-the double-search self-healing algorithm-is proposed. It is shown that this algorithm can restore failed bidirectional VPs faster and find alternate VPs more effectively than existing self-healing algorithms. Second, it is shown that the restoration information for self-healing control (SHC) messages must be transferred by specific cells carrying the control and OAM information (Ic&o). Message parameters and a cell format are proposed. Third, evaluation of the restoration characteristics using the proposed self-healing algorithm by computer simulation indicates that good performance against a transmission link failure is obtained even in a large-scale network model with 110 nodes. The results also indicate that the VP group (VPG) method can improve the restoration time without reducing the restoration ratio     

攀枝花市建设骨干光缆环陬实现光网自愈保护功能

主要介绍攀枝花广电利用1550nm技术与设备,根据业务的需求和用户群的分布不同,并结合原有的光缆网络实际情况,适时推进骨干光缆环网的建设和完善,实现骨干光网自愈保护功能,以提供可靠优质稳定的光缆传输网络,为将来多业务传输及信息服务奠定基础。     

数字孪生在供水运行调度中的发展及应用

供水管网的有序运行对保障城市居民的基本生活质量至关重要。对于供水企业而言,加强对供水管理的认识,实现可持续发展,既可以为人们带来实实在在的好处,也可以为企业带来可观的收入。当前,城镇供水调度系统基于供水管道的基础信息,以供水生产数据采集为主要方式,通过监测水厂、管网的运行状况,可以实现数据采集、数据展示、数据存储、报警等功能,为供水管网的优化运行和调度管理提供了技术支持。文中论述了数字孪生在智慧供水建设中的重要作用,探讨了数字孪生在供水运行调度中的关键问题,指出了数字孪生在供水运行调度中的重要性。     

家庭多媒体网关的技术与应用

家庭多媒体网关是实现家庭网络内部各设备与外部设备相互通信的设备,是家庭网络中最核心的构成部分。通过家庭多媒体网关,家庭网络内的设备可以与公共网络进行信息交互,也可以进行内部设备之间的信息交互。家庭多媒体网关在家庭内部建立统一的数据处理中心,对家庭内部数据进行管理,对外连接运营商网络。智能家庭多媒体网关在实现传统网关和数字电视的基础上,借助于强大的内部组网,实现更为丰富的功能和多媒体应用。     

A passive protected self-healing mesh network architecture andapplications

The self-healing mesh network architecture using digital cross-connect systems (DCSs) is a crucial part of an integrated network restoration system. The conventional DCS self-healing networks using logical channel protection may require a large amount of spare capacity for network components (such as DCSs) and may not restore services fast enough (e.g., within 2 s). The authors propose a passive protected DCS self-healing network (PPDSHN) architecture using a passive protection cross-connect network for network protection. For the PPDSHN architecture, network restoration is performed in the optical domain and is controlled by electronic working DCS systems. Some case studies have suggested that the proposed PPDSHN architecture may restore services within a two-second objective with less equipment cost than the conventional DCS self-healing network architecture in high-demand metropolitan areas for local exchange carrier networks. The proposed PPDSHN architecture may apply to not only the centralized and distributed control DCS network architectures, but also asynchronous, SONET and ATM DCS networks. Transparency of line rates and transmission formats makes the PPDSHN network even more attractive when network evolution is a key concern of network planning     

城市公交查询系统的设计

以城市的实际情况对公交查询系统进行研究,对详细的问题定义与用户需求进行合理的设计,并实现了面向用户的城市公交信息系统.本系统前台开发用JAVA语言,后台管理用MySQL数据库.系统主要包括线路查询功能、站点查询功能、换乘查询功能、留言板功能,以方便用户更便捷地查询到所需乘坐的车次,从而节约出行时间.     

VC++环境下的UDP网络通信实现

随着计算机技术,网络技术,通信技术的迅速发展,越来越多的网络信息走入了大众的生活,对网络信息的传输设计和实现技术要求也越来越高.本文分析了利用套接字实现网络通信的原理,研究了基于VC的UDP网络编程的设计与实现.     

城市供水管网管理信息系统的实现

针对城市的不断建设,给水管线已经非常庞大、密集。采用传统的手工管理已经不能满足实际的需要,必须采取更有效的机制和方法来进行管理。因此,供水公司开始着手实施给水管线GIS建设,利用先进的GIS技术建立供水管网信息管理系统,通过数据库进行管网和地形、地物的空间存储,供水管线信息以数字的形式进行获取、存储、管理、分析、查询、输出、更新,实现供水管线数字化管理、地下管线数据的动态管理,提高城市的管理、运营效率。     

Twitter information for contributing to the strategic digital city: Towards citizens as co-managers

Actions towards an effective city management require a focus on citizens, and it is a role of local governments to search for ways to provide their participation in the decision-making process. Among other information technology resources, local governments use social platforms thus facing the challenge of extracting and classifying information for strategic use. The objective of this study is to analyze Twitter information to contribute to the strategic digital city. The research methodology used was a case study of a Brazilian city. Twitter was analyzed, and the information assessed according to its characteristics, source, nature, quality, intelligence and organizational level. Results reveal Twitter allows communication, rudiments of public services and exchange and sharing information on municipal themes inherent to strategic digital cities. Information has quality and intelligence to serve the strategic level of government. The conclusion confirms that Twitter enhances transparency and strengthens bonds between local government and citizens.     

ATM-PON自愈环保护结构及其性能分析

随着APON在接入网市场占有率的不断上升,人们对APON接入网的可靠性和灵活性也提出了更高的要求。基于此,在简单比较了现有的几种APON自愈保护机制的基础上,根据ITU-T G983.5建议,探讨了一种类似于SDH自愈环的高可靠性APON网络拓扑结构,详细分析了其APS协议操作过程及实现方案,最后给出了这种方案的性能评价。     

Fast restoration of ATM networks

Asynchronous transfer mode (ATM) is now well recognized as the fundamental switching and multiplexing technique for future broadband ISDN. As these networks will be increasingly relied upon for providing a multitude of integrated voice, data, and video services, network reliability is a key concern. There are several intrinsic features of ATM networks that could potentially be exploited to provide improved restoration techniques, beyond those established for synchronous transfer mode (STM) networks, such as digital cross-connect restoration or self-healing rings. These features include ATM cell level error detection, inherent rate adaptation and nonhierarchical multiplexing. The authors explore the use of these features in developing fast restoration strategies for ATM networks. In particular, they address: (1) ATM error detection capabilities for enhanced failure detection, (2) network rerouting strategies, (3) spare capacity allocation, and (4) network control architecture and related implementation aspects. Their findings suggest that fast network span failure detection and bandwidth-efficient rerouting capabilities can be combined to develop restoration strategies for ATM networks with significantly greater performance-cost ratios when compared to existing STM network restoration strategies     

The effect of VP switches on the performance of backup-VP algorithm in ATM self-healing networks

In this approach, three typical implementation schemes of self-healing function in VP switches are discussed and three corresponding queue models for backup-VP self-healing algorithm are established. Computer simulations are made to these queue models, and detailed analyses are presented to the effect of both the three implementation schemes of self-healing function and some architecture parameters in VP switches on self-healing performance.     

Field trial of full-mesh WDM network (AWG-STAR) in metropolitan/local area

We describe a field trial of a wavelength routing full-mesh wavelength-division-multiplexing (WDM) (AWG-STAR) network for citywide local administration in Japan. An AWG router and five WDM nodes were connected to the existing fiber in the downtown area of the city of Chitose, Hokkaido. A 5 /spl times/ 5 full-mesh network was overlaid on the Chitose intranet. A video-on-demand system based on Gigabit Ethernet links, high-definition serial digital interface signals, and synchronous digital hierarchy signals of STM-16 links are transmitted and routed simultaneously on the wavelength paths of the network. These systems are used for administration and education information sharing for city residents. The network is managed and controlled remotely from the NTT R&D Center in Atsugi, Japan, which is 50 km southwest of Tokyo and approximately 1000 km from Chitose. AWG-STAR exhibits promising potential as a large capacity network system for both simple full-mesh systems and highly secure private networks.     

From smart cities to smart social urbanism: A framework for shaping the socio-technological ecosystems in cities

Advocated mostly by technology companies, the smart city concept promises participation, democratization and innovative urbanism. Tracking these promises and ideas, this paper explores “smart urbanism” in ten cities from all over Israel. Based on interviews with leading figures in municipalities, smart city consultants and key figures in technological companies (n = 40), the aims of this paper are to assess the efforts of cities to become smart by responding to the following questions: 1. What is guiding the decision-making process in developing technological initiatives? 2. Does context play a role in implementing technological initiatives? 3. How are the residents perceived, and what tools are being used to address residents' digital differences? The key argument of this paper is threefold: first, in the process of becoming a smart city, the roles of public and private actors are blurred, influencing the process of decision making. Second, despite contextual differences, cities adopt similar digital initiatives. Third, technological initiatives that focus on social needs and address inequality in the digital age are still at the margins. The final discussion suggests that most municipalities are still at an early stage of digitization implementation and have the ability to shape and form a vision for the cities as socio-technological ecosystems in a way that will serve their publics as a whole. The paper ends with a call for shifting the focus from the city to society in developing digital initiatives and cultivating smart social urbanism.     

NFV故障关联及故障自愈方案研究

利用NFV实现电信网络设备软硬件解耦,摆脱了对专用硬件设备的依赖,并能利用NFV资源共享、自动部署、弹性伸缩等特性,但同时也带来了故障点多、故障定位分析困难等问题,导致NFV网络的运营维护难度增加。分析了NFV故障处理的流程及故障关联方案,为NFV场景下的故障定位处理提供指引。同时给出了VNF故障自愈实现方案,利用VNF特性,实现网元及业务自愈,提升自动化运维能力。     

Information and Telecommunications Project for a Digital City: A Brazilian case study

Making information and telecommunications available is a permanent challenge for cities concerned to their social, urban and local planning and development, focused on life quality of their citizens and on the effectiveness of public management. Such a challenge requires the involvement of everyone in the city. The objective is to describe the information and telecommunications project from the planning of a digital city carried out in Vinhedo-SP, Brazil. It was built as a telecommunications infrastructure of the kind of “open access metropolitan area networks” which enables the integration of citizens in a single telecommunications environment. The research methodology was emphasized by a case study which turned to be a research-action, comprising the municipal administration and its local units. The results achieved describe, by means of a methodology, the phases, sub-phases, activities, approval points and resulting products, and formalize their respective challenges and difficulties. The contributions have to do with the practical feasibility of the project and execution of its methodology. The conclusion reiterates the importance of the project, collectively implemented and accepted, as a tool to help the management of cities, in the implementation of Strategic Digital City Projects, in the decisions of public administration managers, and in the quality of life of their citizens.