接入 ATM交换网的 HDSL适配卡技术

我国的用户接入网以铜线为主。在实施接入网的宽带化过程中，若直接采用光纤或光纤同轴电缆提供宽带业务，巨额投资及大量的淘汰设备所带来的巨大无疑成为其快速发展的一大障碍，利用现有铜缆传送数字化多媒体信息成为讨论的重点。HDSL－在现有市话电缆上实现高速率数字传输的技术，可以实现铜缆接入网的宽带化。主要介绍了HDSL采用的关键技术，设计实现了接入ATM交换网的HDSL接口电路，给出了软件流程图和测试结果（测量1h后双向误码率均为10^-7)。

Technique of HDSL Adaptation Card of Accessing to ATM Exchange Network

The Access Net of users in our country is primarily based on Copper-li ne. During the course of implementing Broad Band of Access Net, if optic fiber o r its coaxial line is used to provide Broad Band operation, the high investments and the large wastes caused by vast discarded equipments will become a great ob stacle to its rapid development. So using Copper-line in existence to transmit digital multimedia information has become a focus in study.High Bit Rate Digital Subscriber Lines is a new technique that realizes high bit rate digital transmi ssion on current common telephone lines. With this new technique, we can realize Broad Band on Copper-line Access Network. The paper chiefly introduces the key techniques of HDSL, designs and realizes HDSL interface circuit over ATM Exchan ge Network, and presents relevant program flow chart and some test results (the error code rates of double directions are both 10-7 after one hour test).