ISDN與其他通訊迴路技術之比較分析

Abstract

本研究藉由SDN的發展經驗建立一個ISDN技術評估模式，其主要分析構面 包括技術標準、網路架構、技術與功能、產品、應用、設備的價格、通訊 資費、市場需求與競爭技術等。本研究針對ISDN與其他競爭技術如Modem 、HDSL、ADSL及Cable Modem進行分析比較。探討這些競爭技術對ISDN產 業發展的影響。在ISDN產業形成之初，重點在標準的訂定、網路架構的設 計與技術的開發；當產業進入初期商用階段，其重點在產品與應用的開發 ；在產業進入商用推廣階段，重點在展現經濟效益，以及是否能大量普及 ，其關鍵則在應用、設備的價格、通訊費用、其他產業的配合及足以與替 代技術抗衡的優點。全球有數十億條雙絞銅線的POTS迴路，所以Modem可 以服務的空間仍很開闊，更何況Modem產業繼56 Kbps之後，正開發結合數 條POTS線路可以提供較高速數據傳輸的技術。由於HDSL和ADSL在技術上的 提昇，自有其在取代T1/E1的市場，以及滿足部份Internet用戶的需求。 Cable Modem開發同軸電纜的頻寬資源，潛力無窮，目前受限於具有上行 頻道的網路不多，以及干擾嚴重。ISDN由於具備完整而複雜的網路功能， 這些優點不是僅具備有頻寬的傳輸功能所能取代的。 Referencing the development history of ISDN, this thesis proposed an ISDN technology forecast and impact assessment model, which include the following aspects: standards, network architecture, functionality , equipment/ products cost, applications, markets and alternative technologies. ISDN and its competing loop access technologies such as Modem, HDSL, ADSL and Cable Modem were analyzed based on the above model. The purpose was to understand the impact of these competing technologies on the ISDN market deAt the ISDN trial stage, the key success factors included the establishment of standards, network architecture and technology; at the early introduction phase, the key factors were the availability of products and applications; when ISDN got into the commercial deployment phase, the key point was to show the economic benefit.There exists over 6 billion POTS lines around the world, hence the usefulness of Modem shall sustain for a long time. Modem manufacturers are pushing higher data transmission rate over bundles of several POTS lines. Due to the higher transmission capacity and longer transmission distance developed by HDSL and ADSL, there is T1/E1 replacement market and some Internet access applications for HDSL/ADSL. Cable Modem is exploring the broadband resources of CATV HFC network, its potential is unlimited. ISDN has an abundant of end-to-end networking features which can never be surpassed by other loop access technologies.