摘要 随着Internet的爆炸式发展,在Internet上的商业应用和多媒体服务也得以迅猛推广。要享受Internet上的各种服务,用户必须以某种方式接入网络。为了实现用户接入网的数字化、宽带化,提高用户上网速度,光纤到户(FTTH)是用户网今后发展的必然方向,但由于光纤用户网的成本过高,在今后的十年内大多数用户网仍将继续使用现有的铜线环路,于是近年来人们提出了多项过渡性的宽带接入网技术,包括N-ISDN、Cable Modem、ADSL等等,其中ADSL(非对称数字用户环路)是最具前景及竞争力的一种,将在未来十年内占主导地位。 本课题具体讨论了ADSL原理和特点,以及相关技术。讨论了在不同环境下(家庭、企业等)ADSL不同的接入方案,并对各种方案进行分析。最后用VC编程模拟PPP协议。 Abstract With the development of Internet, the commercial application and multimedia serve on the Internet develop widely. If user want to enjoy these serve, they must link their pc to Internet through some ways. Certainly, using fiber is a good way. But it is too expensive for normal user in ten years. For this, people advanced some ways, such as N-ISDN, Cable Modem, ADSL. Because of it’s advantage, ADSL will occupy dominant status. This task discuss ADSL’s theory and characteristic, correlation technique. Finally, we use VC simulate PPP protocol.
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