VDSL与ADSL、以太网的比较

宽带接入网络是近年来各运营商投资建设的重点，主要接入手段有以太网接入、ADSL和VDSL等技术，各运营商根据其网络特点进行了大量的实验。这几种宽带接入技术有什么区别，哪种更适合我国的国情，其应用前景如何，这些正是电信运营商和制造商目前最关心的问题。最近传统铜线上的VDSL接入方式因其接入速率大幅度提高而备受业界关注，通过对VDSL技术原理和实现方式的分析，我们认为，VDSL（EVDSL－基于以太网的VDSL）是远程以太网技术，而不是ADSL的升级版本。VDSL（Very high speed DigitalSubscriber Line）90年代中期开始…     

VDSL及以太网宽带接入

首先回顾了宽带接入技术的发展，然后介绍了VDSL和以太网交换这两种技术的现状，着重分析了它们的基本工作原理和设计思想。最后以亿恒公司的芯片解决方案为例，为采用VDSL和以太网交换的宽带接入系统给出了一种功能完整的实现方法。     

新品展馆

基于IP的VDSL 当宽带技术世界正走向全IP技术时，并非每个人都关注IP。VDSLSystems公司推出基于IP的VDSL系统，供应商可用基于IP的VDSL，采用原有的和基于ATM的DSL网平滑过渡方式来平衡VDSL上的IP功效。业务供应商可将VDSL部署到邻居、公寓大楼、宾馆和办公大楼或家庭网上。SpeeDLSAMVDSLIP接入复用器开始实施与快速以太网、千兆以太网、ATM和光网VDSL连接功能。iVALOVDSL接入路由器设在用户驻地，以便为桌面分配终端VDSL连接。iVALO可根据需求调节带宽，使之适应特殊用户性能需要。此外，所选用的路由…     

VDSL及以太网宽带接入

首先回顾了宽带接入技术的发展，然后介绍了VDSL和以太网交换这两种技术的现状，着重分析了它们的基本工作原理和设计思想，最后以亿恒公司的芯片解决方案为例，为采用VDSL和以太网交换的宽带接入系统给出了一种功能完整的实现方法。     

基于VDSL及以太网宽带接入的研究

互联网技术不断发展的今天,上网速度的提高以及成为了大多数宽带用户的需求.VDSL和以太网宽带接入技术的相结合,满足了用户对高速宽带接入方式的需求.首先,本文描写了VDSL的特征.其次,简单的对以太网宽带接入做出介绍.最后,提出了基于VDSL及以太网宽带接入的具体研究.     

VDSL宽带接入技术

由英飞凌科技赞助的“亚太地区以太网接入峰会”于2003年11月24-25日在上海召开。本次峰会讨论议题包括：以太网接入策略、部署和技术，市场商业开发、商业驱动以及提供以及网服务。VDSL技术以其高带宽和经济、高效等特点成为会议讨论的一大亮点。英飞凌科技就以太网与VDSL内容进行了深入的探讨，并展示了其IC技术领域的最新创新。     

各厂商助力中国DSL市场——聚集China 2004DSL研讨会

亚洲一直是全球范围内DSL用户市场增长速度最快的区域。在中国，ADSL的应用近几年来不断得到推广，发展势头强劲．用户数进入快速增长时期。同时，由于VDSL技术，特别是以太网与VDSL结台的EoVDSL方式，与ADSL和以太网接入相比具有一定的潜在优势，也得到了运营商和设备制造商的广泛关注。     

浅议VDSL和ADSL混插技术

基于铜缆的xDSL宽带接入技术目前在市场上已有广泛的应用，作为其主流的ADSL和VDSL技术将会随着技术的发展而逐渐走向融合。在现有的网络中，IP几乎占领了整个城域网领域，如采用基于ATM的ADSL技术，则需解决ATM与IP之间的转换和效率问题，同时ADSL技术本身还存在着速率不对称、带宽较小以及出线率低等不可克服的缺点。为了适应网络和业务全面IP化和以太网化的发展需求，同时解决ADSL技术存在的问题，基于以太网内核技术的VDSL应用而生了。VDSL不仅解决了ATM和IP之间的转换问题，而且还克服了传输带宽小和出线率低等问…     

宽带城域网组网技术及业务应用(下)

本文结合现有技术特点及发展，根据电信新业务对技术的要求，各种技术的优缺点等分析其在宽带网中的应用和市场前景，认为VDSL是近期最适宜的接入技术，以太网技术用于电信城域网在产难克服的缺点，并论及电信级以太网的组网和设备选型。     

新品方案

爱立信向丹麦TDC提供基于VDSL2的高性能宽带技术近日,丹麦运营商TDC部属了爱立信的VDSL2宽带技术,通过高性能的宽带体系结构提供包括互联网、IP语音通信和IP电视在内的三重播放业务。VDSL2是下一个主要的DSL宽带技术,也是首个能够实现端到端以太网体系架构的技术,从而实现了网络的简     

宽带接入技术

介绍了ADSL /VDSL、以太网、IP无线本地环路、LMDS及无线移动等数据接入技术 ,并对其特点作了分析与比较。     

基于VDSL技术的高速传输单元设计

首先回顾了VDSL技术的发展现状和技术特点,然后介绍了一种单芯片VDSL系统解决方案的结构和基于该技术的高速传输单元设计方案,包括系统基本原理,软硬件设计,并给出了系统的2种典型应用示例和有关测试数据。该高速传输单元具有模块化、灵活配置的特点,配合简单的外部接口电路,可实现一路以太网接口或高速同步接口的有线远距离传输功能,利用单对双绞线作为传输介质,传输距离可达1km以上。     

TDD-VDSL兼容ADSL频谱的子频带抑制方法

VDSL是数字用户线技术中的最新技术,宽带接入的最佳方案之一。为了提高VDSL系统的传输速率,它有必要兼容现行ADSL系统的频谱。本文通过对VDSL系统的双工方式及兼容ADSL系统的可行性分析,提出了VDSL系统的可用功率谱密度及TDD-VDSL系统兼容ADSL频带的子频带抑制方法,并进行了仿真分析。结果表明在不同的运行环境下,都有很好的性能,是一种有效的实用方案。1     

DWDM-based FTTC access network

This paper proposes a dense wavelength division multiplexing (DWDM)-based fiber-to-the-curb (FTTC) access network architecture for broad-band services. The reaches of four carrierless amplitude phase (4-CAP)-modulated very high-speed digital subscriber line (VDSL) signals over the hybrid-fiber twisted pair (HFTP) were simulated. The simulation results show that the effect of noise from the optical link is negligible as long as the signal-to-noise ratio (SNR) of the optical link output signal is 9-10 dB greater than the required SNR of a VDSL modem. The bit error rate (BER) of the VDSL transmission over HFTP was measured. Measurement results show that insertion of the optical link between the modem and twisted pair has no adverse effect on the transmission     

Systems aspects of APON/VDSL deployment

The purpose of this article is to provide an overview of some system aspects allowing full service deployment over hybrid fiber-twisted pair access networks with a VDSL drop. Although VDSL and ADSL systems are similar from the point of view of transmission technology, there are differences in the architecture and implementation due to both the higher bandwidth and shorter copper loop length for VDSL. The VDSL drivers are given in the introduction. The next section describes the system architecture and the functionality of the various building blocks. Special attention is paid to optical feeder technology, for which APON is a well-suited technology. Concepts to reduce the cost of ownership are also discussed     

A short overview of the VDSL system requirements

This article gives an overview of VDSL and summarizes the main system requirements developed by ANSI-T1E1.4, ETSI-TM6, and ITU-T Study Group 15/Question 4 in a coordinated effort. For the time being, both single-carrier modulation and multicarrier modulation schemes have been proposed for standardization. VDSL is an enabling and cost-effective access solution for the last mile of the network over ordinary existing telephone lines. This new standard targets aggregated data rates up to 52 Mb/s on short loops. VDSL can be used to provision broadband services for both residential and business.     

Delivery of IP over Broadband Access Technologies

This paper provides an overview of the broadband access technologies that can be used to deliver IP-based services. It describes BT's architecture for delivery of IP services over asymmetric digital subscriber line (ADSL) and then explains the evolution of this wire-line delivery mechanism towards higher bandwidth hybrid fibre/copper access architectures using APON and VDSL.     

VDSL数字用户环路接入及其关键技术

本文首先介绍了VDSL的体系结构,然后就实现VDSL接入的关键技术如线路编码技术,以及复用技术和回波抵消技术等相关技术进行了分析,最后指出了VDSL的发展现状和前景。     

ATM passive optical networks and integrated VDSL

VDSL offers a cost effective solution for the provision of a full-service broadband access network. Standards are emerging that will define the line code, duplexing method, and spectrum requirements for VDSL. VDSL chipsets and modules are becoming available that allow the technology to be evaluated in the field. This article describes the architecture and hardware integration that has been performed in integrating VDSL technology into an ATM PON system     

Broadband access using subcarrier multiplexing and asymmetric digital subscriber lines

A broadband access system using subcarrier multiplexing on optical fibre and asymmetric digital subscriber lines (ADSL) or very high‐speed digital subscriber lines (VDSL) on unshielded twisted‐pair is proposed to provide broadband access. In this hybrid‐fibre/twisted‐pair (HFTP) system, the digital multiplexing/demultiplexing process is moved back to the central office by using subcarrier multiplexing for fibre transmission. Instead of installing in remote node, ADSL/VDSL transceivers are installed at the central office to greatly reduce the remote node complexity. The local node simply down‐converts the subcarrier multiplexed ADSL/VDSL signal to the baseband, suitable to send directly into the twisted‐pair. The reduction of complexity could result in a lower initial installation cost, especially for a low service penetration rate. Copyright © 2000 John Wiley & Sons, Ltd.