光纤接入网技术------英文文献翻译.doc

The entire telecommunication network according to network function is divided into three sections: switching, transmission,and access. Access to telecommunications business transparent to users, transmit specific, access to local switch and the user that the connection between the parts, usually include subscriber line transmission system, reuse equipment, crossing connection device or user/network terminal equipment. And actually pick for business entity is business nodes.
1. Access network development process
1.1 Access Network (AN: Access by business) refers to a node interface (SNI) and related users Network interface (UNI) between a series of transmit entity (such as line facilities and transmission facilities) for transmission consisting of telecommunication business provide the required transmit load capacity, implementation system configurations percentile management interface via and management. Access can be seen as with business and application irrelevant transmission network, mainly finish crossing connection, reuse and transmiss


整个电信网按网络功能分为三个部分：传输网、交换网和接入网。接入网负责将电信业务透明传送到用户，具体而言，接入即为本地交换机与用户之间的连接部分，通常包括用户线传输系统、复用设备、交叉连接设备或用户/网络终端设备。而实际上接供业务的实体就是业务结点。
一． 接入网的发展历程
1. 接入网（AN：Access Network）是指由业务节点接口（SNI）和相关用
网络接口（UNI）之间的一系列传送实体（诸如线路设施和传输设施）所组成的为传送电信业务提供所需传送承载能力的实施系统，可经由Q3管理接口进行配置和管理。接入网可以被看作是与业务和应用无关的传送网，主要完成交叉连接、复用和传输功能，对用户信令来说是透明的。基于现代电信网的接入网是综合业务接入网，简单的本地话音接入将越来越不能满足需要，语音、数据、图像的综合接入正成为接入网的发展趋势。经过多年的发展，接入网的界定虽然没有变，但其内涵和形式发生了很大的变化。性能明显优于传统接入网的综合光纤接入网将是用户接入网今后的发展趋势。光纤接入网是指从SNI到UNI全部或者部分采用光纤作为媒质的接入网。ITU-T关于光纤接入网的建议指出，用户接入系统由三部分组成：局端设备（OLT）、光分配网络（ODN）和光网络单元（ONU）。