因地制宜地建设ADSL宽带接入网

本文介绍了ADSL宽带接入网技术发展的三个阶段，重点进行了ATMDSLAM和IPDSLAM技术特点的比较。指出了ADSL宽带接入网的一些思路，建议做好网络规划，因地制宜，建设性能价格比高的ADSL宽带接入网。     

接入网

接入网是通信网络的一个重要组成部分，本讲座首先简要介绍了接入网的基本概念，然后描述了ADSL接入技术。本篇描述了接入网的定界、特点、分层模型、功能模块、参考模型和分类。     

ADSL监控子系统设计

简要介绍接入网中的不对称数字用户线（ADSL）技术，然后从模块结构、功能设计、用户界面等方面详细分析了ADSL监控子系统的设计与实现，并给出了一种实现方案。     

对ADSL接入网建设中存在问题的探讨

分析了在ADSL接入网大规模建设中出现的问题，并探讨解决的方法。     

ADSL技术及其应用

介绍了ADSL宽带接入网技术和三种调制技术，最后阐述了ADSL在用户接入网中的一种应用并展示了ADSL的发展。     

ADSL网络内开展多播技术的探讨

宽带接入热潮正在兴起，各大电信运营商广泛铺设ADSL接入网络。在ADSL网络中能否开展多播这种增值业务一直是令人关注的课题。本从宽带接入网的结构和认证方式人手，分析开展多播业务的可行性，并对多播在ADSL网的未来应用前景作了展望。     

ADSL网络中开展多播技术的探讨

宽带接入热潮正在兴起，各大电信运营商广泛铺设ADSL接入网络。在ADSL网络中能否开展多播这种增值业务一直是令人关注的课题。本文从宽带接入网的结构和认证方式人手，分析开展多播业务的可行性，并对多播在ADSL网的未来应用前景作了展望。     

宽带接入的应用与发展

１宽带铜线接入网为了利用现有用户线资源，世界各国电信运营公司正积极开发宽带铜线接入技术，包括ADSL、HDSL和VDSL等，统称xDSL技术，现已陆续投入商用。xDSL技术可为用户提供宽带接入服务，满足Internet基本服务的要求。目前被看好的是ADSL技术及它的简化版本。1999年6月，ITU正式通过无分路器ADSL（G.lite）技术的国际标准G.992，为业务提供者和设备供应商开发产品、推广业务扫清了障碍。G.992是单一开放的标准，与全速率ADSL兼容，可平滑升级为全速率ADSL，有利于快速大规模地开展业务。一些计算机厂商已开始在计算…     

ADSL宽带IP接入技术

本介绍了ADSL的基本原理和基本体系结构，IP接入网的参考模型和ADSL接入的模式，以及ADSL上的IP接入技术。     

广东省全面铺开用户接入网的建设——用户接入网建设的相关问题

广东省用户接入网的宽带化，数字化已成当之急，全面铺开全省用户接入网的建设也是电信市场竞争的需要：对接入网技术，设备选用提出了对策，强调光纤接入网是用户接入网发展的主要方向，广东省用户接入网的发展建设策略是着手制定发展规划及其建设和接入网光节点设计等工作，强调要因地制宜，有计划，有步骤地进行建设；最后提出建设目标和实施办法。     

应用于移动e-商务中一种新密码安全体系的分析

本文介绍了一种新的移动终端接入网络实现e -商务技术 ,将应用于桌面终端 ,固定网络接入的密码应用编程接口 ,用于利用PPC和智能手机开发的WindowsCE嵌入式操作系统。文中分析了应用于windows2 0 0 0 /XP密码应用编程接口移植于移动通信的主要技术 ,探讨了应用策略、方法以拓展移动通信新业务     

基于无线自组网的网络层交换软件设计与实现

研究了一种应用于无线自组网的网络层交换软件,通过系统模型的抽象和建立,将网络层需要实现的功能独立出来,进而制定了本地及全局路由的建立与维护、网络层数据交换等关键策略,综合运用了多线程设计、网络编程、驱动设计等多种编程技术,在高速ARM平台上,基于嵌入式Linux操作系统实现了网络层交换系统软件,使标准网络设备无需任何改变即可接入自组网节点设备,并能够通过无线自组网进行通信,解决了接入设备的数据寻路与数据交换问题。     

锦朝高速公路光综合业务接入系统解决方案

介绍了锦朝高速公路光综合业务接入系统的总体设计方案,讲述了系统设计的组织原则、接入业务需求类型、业务数量和带宽、网络管理、网络同步、系统保护和供电等。     

浅谈城市光纤接入网的规划设计

介绍了城市光纤接入网的总体设计方案,论述了城市光纤接入网规划建设的特点、方式、原则、步骤和建设方案。     

可生存光纤—无线融合宽带接入网规划方法

光纤—无线融合（fiber-wireless,FiWi）宽带接入网的出现不仅为随时随地的灵活宽带接入提供了新的技术参考,同时也为可生存宽带接入网的低成本设计增加了研究契机。研究了可生存FiWi接入网的网络规划问题,提出一种基于无线重路由保护的可生存网络规划方法。当任意光纤链路断裂时,失效的光网络单元可通过无线重路由将业务转移到其他可用的光网络单元承载。重点解决了无线路由器部署、备份射频接口配置及光网络单元容量分配的联合优化问题,目标是通过最小化网络部署成本实现业务的完全保护。采用整数线性规划方法获得了小规模网络规划问题的最优解,同时提出了适用于大规模网络规划问题的启发式算法。仿真结果证实了所提方法在降低网络部署成本方面的有效性。     

A Location-Routing Problem in Designing Optical Internet Access with WDM Systems

In this paper, we deal with a location-routing problem in designing the optical Internet with WDM systems. This problem arises from the design of broadband local access networks that deliver high-speed access service to residential subscribers. The problem is to find an optimal location of the gateway and optimal routing of traffic demands in the optical access network. We develop mixed-integer programming models for solving the location-routing problem to minimize the total cost of network elements used in the network while carrying the offered traffic. By exploiting the inherent structure of the problem, we derive two effective tabu search procedures. We present promising computational results of the proposed solution procedures.     

Evolutionary mobility and service support in DECT access networks

This paper presents an access-independent network architecture for supporting UMTS service capabilities. The approach is based on an enhanced B-ISDN core network with personal and terminal mobility provided by intelligent network techniques. A physical realization is presented, and the protocols corresponding to the physical interfaces are identified. Protocols are proposed for UMTS mobility and service support, and the impact on the B-UNI and IN interfaces is considered. Reflecting the vision of the ETSI global multimedia mobility (GMM) standardization framework, UMTS service support through non-UMTS access is considered. Consideration of DECT as a UMTS access technology leads to an interworking proposal that presents each DECT terminal to the core network in terms of UMTS functional entities. Access-independent usage of UMTS terminal applications motivates additional interworking in the terminal to encapsulate the access network. The desirability of an access-independent UMTS application programming interface in the terminal is indicated     

RDS远程数据访问技术研究

基于网络的计量测试系统需要解决的问题之一就是远程数据访问。对ADO的RDS的对象模型和编程模型进行研究,阐述RDS的功能和特点,研究RDS数据访问技术的具体实现方法,分析RDS的安全性并提出相应的解决方案。作为一种先进的数据访问技术,RDS能为计量测试系统远程数据访问提供有力的技术基础。     

Coordinated dual-homing in designing hierarchical wireless access network with a genetic algorithm based approach

With the growth of mobile users and the increasing deployment of wireless access network infrastructures, the issue of fault tolerance is becoming an important component of efficient wireless access network design. In this work, we study a survivable hierarchical network design problem. Given the available capacity, connectivity, and reliability at each level, the problem is to minimize overall connection cost for multiple requests such that the capacity, connectivity, and minimum survivability constraints are not violated. Our study is different than earlier research in regard to the coordination of multiple layers of access networks. The connectivity to the core network may be fully or partially dual-homed paths, or may be single-homed paths. Dual-homing schemes spanning to different levels in the network hierarchy are used if the single-homed connectivity is not enough to guarantee the minimum required survivability. We formulate the problem using mixed integer linear programming and prove the complexity class to be NP-hard. We then propose an off-line genetic algorithm based meta-heuristic. Given the complexity of the problem, simulation results demonstrate that the proposed approach is viable in designing fault-tolerant access networks with dual-homing capability.     

Highly efficient optical aggregation network with network functions virtualization

Network functions virtualization enables network edge functions to be relocated from dedicated hardware to distributed pools of commodity servers. Metro aggregation networks provide transport between access gateway nodes and such servers accommodating virtual network functions (VNFs). Networks need to be designed to increase the efficiency of network resource usage and reducing network cost as well as energy consumption. However, independently placing VNFs on a server from a physical network design degrades the efficiency of resource usage and causes an increase in network cost. We can avoid such problems by adequately placing each VNF in consideration of the location of access gateway nodes and a network topology. We thus propose a method for designing an optical aggregation network with VNF placement. We successfully formulate the design method as mixed‐integer linear programming and demonstrate its effectiveness through intensive mathematical experiments. The experiments showed that the proposed method reduced network cost by up to about 18% while performing almost optimally in terms of server load dispersion.