论文部分内容阅读
随着Internet带宽的持续增加,人们越来越关注从高速网络到“最后一公里”的传输瓶颈问题。厂家也非常想通过新技术、新产品分享这个面向千万用户的广大市场。有关厂家都试图利用现有的基础设施,以自己的优势技术争夺用户。其中,xDSL技术正是为克服“最后一公里”而产生的,它利用现有电话线路,采用特殊调制技术以提高传输速率。但xDSL技术还未普及,标准较多,前景还不十分清晰。一、xDSL技术概述 xDSL是各种类型DSL(DigitalSubscribe Line)的总称,包括ADSL、RADSL、VDSL、SDSL、IDSL和HDSL等。xDSL是一种新的传输技术,在现有的铜质电话线路上采用较高的频率及相应调制技术,即利用在模拟线路中加入或获取更多的数字数据的信号处理技术来获得高传输速率(理论值可达到52Mbps)。各
With the continuous increase of Internet bandwidth, people pay more and more attention to the transmission bottleneck problem from the high speed network to the “last mile”. Manufacturers are also very much like to share this vast market for millions of users through new technologies and new products. The manufacturers are trying to use the existing infrastructure to compete with their own superior technology users. Which, xDSL technology is to overcome the “last mile” and the resulting use of existing telephone lines, using special modulation techniques to increase the transfer rate. However, the technology of xDSL has not been popularized yet and the standard is more, the prospect is not very clear. First, the xDSL technical overview xDSL is a general term for various types of DSL (DigitalSubscribe Line), including ADSL, RADSL, VDSL, SDSL, IDSL and HDSL. xDSL is a new transmission technology that uses high frequency and modulation techniques on existing copper telephone lines, that is, high transmission using signal processing techniques that add or gain more digital data to analog lines Rate (theoretical value up to 52Mbps). each