| 摘要: | 近年來由於網路頻寬需求大增，電腦軟硬體技術的突飛猛進，網路服務供應商（Internet Service Provider，ISP）在寬頻接取網路方面，已陸續使用光纖到大樓（Fiber To The Building ，FTTB），在既有用戶迴路下，推出影像、通訊等服務，以符合客戶的需求。但是由於光纖的成本高且尚未普遍，所以第一代非對稱數位用戶迴路（Asymmetric Digital Subscriber Loop，ADSL）技術的突破便是近年來所要研究探討的方向。 因此國際電信標準組織(ITU-T)已陸續研究出第二代的非對稱數位用戶迴路ADSL2及第三代的非對稱數位用戶迴路ADSL2+，針對舊有ADSL問題來改善，ADSL2+是適於原ADSL架構，其支援的客戶數多且應用也較具彈性。 因此本論文就ADSL系列對於實際現場環境進行探討，對於從電信業者數位用戶迴路多工器（Digital Subscriber Loop Access Multiplexers ，DSLAM）到用戶端線路部份，線路連線品質部份如何提高線路的信號抗雜訊比（Signal Noise Rate，SNR）和降低衰減值進行研究，並且使用遠端數位接取迴路多工器（Remote DSLAM）的建設線路供裝模式，對於偏遠地區與交換局服務區邊界地帶，因線路距離太長，無法提供寬頻網路的困境，利用本研究來改善超出連線速率供裝距離的服務範圍模式，提供一個高速上網的解決方案。 Recently with the wide wideband network demand is heightened in recent years, the advancing by leaps and bounds of complex software and hardware technology , network service supplier (Internet Service Provider, ISP) Have already used the optic fiber to the building (Fiber To The Building, FTTB) successively in the fetching of the wide band network ,Under the original digital subscriber loop（DSL）, can introduce another services as the image, communication etc. In order to accord with these demand, and that optic fiber is with high costs and not general in DSL, so the first generation asymmetry ADSL( Asymmetric Digital Subscriber Loop, ADSL) of technology to break out will be studying is the direction probed into in recent years. So the standard organization of international telecommunications (ITU-T) it is already asymmetry when it work out the second generation of DSL ADSL2 and the third generation of DSL ADSL2 +, point to improve to old ADSL issue, ADSL2+ fit on original ADSL structure, and use more elasticity except several more than customers supporting it. So the thesis carries on the discussion to the real site environment on ADSL series, from telecommunication provider in the office end (Digital Subscriber Loop Access Multiplexers, DSLAM) to the user end, how to raise on the signal noise rate(SNR) quality of circuit line and study with reducing the decaying value, and also use Remote Digital Subscriber Loop Access Multiplexer( Remote DSLAM) far construction circuit support load with way, as to the thing that remote in the area and exchange the border area of serving area of offices, because the distance of the loop is too long, it is unable to offer the predicament of the wide-band network, using the thesis to improve and go beyond the speed of line rate to support the way of service range containing distance, offer a high-speed solution of internet. |
