急求高质量英译汉,15天有效,给100分.机器译的也行.

急求高质量英译汉,15天有效,给100分.机器译的也行.
如果没有正确答案,将把分给翻译质量最好那位,不一定是翻译的最多那位!
Abstract:The Asymmetric Digital Subscriber Line (ADSL) draft standard is nearing completion by ANSI and should become finalized as a standard in 1995.Commercially available products will be appearing later in 1995.As specified in this standard,ADSL technology will provide over a single twisted-pair loop a number of simplex channels (up to 6 Mb/s total capacity) from the central office to a subscriber and a number of duplex channels (up to 640 kb/s total capacity) while leaving POTS service unaffected.Although the intention of the downstream data rates prescribed in the standard are to provide compressed video services,we believe a compelling case may also be made for data services over ADSL.This paper provides an overview of the ADSL standard,discusses video provisioning issues and how ADSL may compare to hybrid fiber-coax in this regard,and introduces a number of concepts for offering new data services using ADSL and existing LAN and WAN technology.
The ADSL standard
A number of years ago ISDN was standardized with a basic rate access of 160 kb/s [2].This digital transport technology was designed to operate over the existing public switched telephone network,including the copper loop plant,and made the ubiquitous twisted-pair into a Digital Subscriber Line (DSL).
More recently,advances in signal processing techniques and processing power have enabled an increase in data rates.As embodied in High-bit-rate DSL (HDSL) technology,bi-directional T1 rates (1.5 Mb/s) are achieved over two pairs of unconditioned lines up to a range of 12,000 feet of 24 AWG cable [31.HDSL presents an alternative for providing standard T1 service over copper twisted-pairs.By requiring no repeaters,loop conditioning or pair selection (allowing the existence of bridged-taps),HDSL allows for faster and lower-cost provisioning of TI service.
By limiting high-rate transmission to one direction only,near-end crosstalk (NEXT) from the same service is reduced,allowing a further increase in the data rate.Given that many service applications such as entertainment video,information services and telecommuting do not require bidirectional high-rate transmission,the concept of Asymmetric DSL (ADSL) arose.As specified in the draft ANSI standard,ADSL will support four loop range options,defined as transport classes,over a single twisted-pair (Table 1).A number of optional rates (such as those based on multiples of 2,048 Mb/s and rates that include ATM overhead) are also specified.

摘要：非对称数字用户线路（ ADSL ）标准草案已接近完成,由ANSI ,并应成为定稿,作为一个标准在1995年.在商业上可用的产品将出现在1995年以后.作为指定的在这方面的标准,ADSL技术将提供超过一个单一的双绞线回路一些简单的渠道（截至6 MB /秒,总容量）由中央办事处,向用户和一些全双工渠道（最多640或/秒,总容量） ,而在离开盆的服务不会受到影响.虽然意向的下行数据传输率明在标准是提供压缩视频服务,我们相信一个令人信服的理由也可为数据服务的ADSL .这个文件规定,概述了ADSL的标准,讨论了视频供应问题,以及如何的ADSL可能比较混合光纤同轴在这方面,并介绍了一些概念,提供新的数据服务使用ADSL和现有的局域网和广域网技术.
有关ADSL的标准
数年前的ISDN是标准化的一个基本的利率获得160是KB / s [ 2 ] .这一数字传输技术的设计运作,比现有的公共交换电话网络,包括铜回路植物,并作出了无所不在的双绞线成为一个数字订户线路（ DSL ） .
最近,进步,信号处理技术和处理能力,使一增加,数据传输率.作为体现在高比特率的DSL （ hdsl ）技术,双向定向T1的利率（ 1.5 MB /秒） ,取得了2对无条件线最多的一系列一点二零零万英尺24 AWG的电缆[ 31 .hdsl提出了一种选择,提供标准的T1的服务年资超过铜扭对.由无需中继器,闭环调节或对选择（允许存在桥-水龙头） ,hdsl允许更快和成本较低的供应钛服务.
问题补充：通过限制高速率传输到一个方向只,近年底的串扰（明年）由相同的服务,是减少,使进一步增加,数据传输率.鉴于许多服务应用,如娱乐,视频,信息服务和远程办公并不需要双向高速率传输,概念,非对称的DSL （ ADSL的）出现.作为指定的在草案中ANSI标准,ADSL的会支持四回路范围选项,定义为运输班,超过一个单一的双绞线（见表1 ） .一些可选的利率（如那些基于倍数2048 Mb / s和利率,包括ATM的开销）也指定.
请LZ参考吧!