臺灣博碩士論文加值系統

有線電視網路(CATV network)在上行頻道頻寬分配是由使用者(station)透過競爭時槽向頭端(Hendend)提出要求，再由頭端統一分配頻寬。而競爭時槽(contention slot:CS)是屬於任意競爭，使用者有資料要傳送就可以在競爭時槽傳送要求向頭端提出頻寬申請。這樣存取方式會把有優先權使用者與無優先權使用者混在一起競爭。因此我們加入優先權式競爭時槽(priority contention slot)概念，即把競爭時槽區分為有優先權與無優先權(nonpriority)兩類，優先權使用者在有優先權競爭時槽提出要求，這種存取方式會使有優先權的用戶端在做要求頻寬時享有較低的平均存取延遲時間(mean access delay)。
另外目前資料與要求是在同一上行頻道傳送，頭端處理進來資料時區分是要求或是資料；即使單純的資料也分不同類型，頭端都要花額外時間去處理。為此我們提出一個分流架構(distributional flow )傳輸模式;就是把上行頻道區分為要求頻道(request channel)與資料頻道(data channel)。而且資料頻道的區分是依照同類型同屬性特徵來分別，所以每一條資料頻道都有其特徵。在資料分流下，同類型同屬型的資料在進入頭端比較容易控制與管理。

Over CATV networks , a station first sends request element to headend for bandwidth when it has data for sending. Stations , having data for sending ,put their request element on contention slot of the upstream for request bandwidth. But the request is random access. So priority stations and nonpriority stations together contend for contention slots. Hence , we have two kinds of the contention slots ,which are priority and nonpriority. This way make the mean access delay of priority station is low.
The other aspect of this paper is a distributional flow concept. Traditionally, a station sends request and data on the same upstream. We let upstreams different characteristic. Stations send the request on the request channel and they send the data on the data channel. This way will make headend easily control and process the data.

章節目錄
第一章 續論………………………………………………………………………...1
1.1 動機…………………………………………………………………………..1
1.2 目的…………………………………………………………………………..2
1.3 章節介紹……………………………………………………………………..2
第二章 有線電視網路架構及媒體存取層協定簡介……………………………...3
2.1 有線電視網路架構…………………………………………………………..3
2.2 媒體存取層協定簡介………………………………………………………..5
2.2.1 傳輸模式…………………………………………………………………..5
2.2.2 測距及傳輸延遲補償……………………………………………………..6
2.2.3 碰撞解決方式演算法……………………………………………………..7
2.2.3.1 二元指數後退法（binary exponential backoff）…………….…..7
2.2.3.2 p-persistence………………………………………………….……8
2.2.3.3 N-ary tree algorithm……………………………………………….8
2.2.4媒體存取層協定簡單介紹……………………………………………….10
2.2.4.1 MCNS…………………………………………………………….10
2.2.4.2 IEEE 802.14………………………………………………………12
2.2.4.3 MLAP……………………………………………………………..13
第三章 802.14操作架構及碰撞解決方式….…………………………………….17
3.1 802.14媒體存取層架構及操作……….……………………………………17
3.2 碰撞解決…………………………………………………………………….20
第四章 優先權式分流架構…………………..……………………………………22
4.1 優先權方式………………………………………………………………….23
4.2 分流操作…………………………………………………………………….26
第五章 訊息格式修正及比較……………..………………………………………28
5.1 訊息格式修正……………………………………………………………….28
5.1.1 要求迷你時槽分配訊息元素…………………………………………….28
5.1.2 答應資料訊息元素……………………………………………………….29
5.2 比較………………………………………………………………………….30
第六章 比較媒體存取層協定………..……………………………………………32
第七章 模擬結果分析……..………………………………………………………33
7.1 模擬環境…………………………………………………………………….33
7.2 模擬結果…………………………………………………………………….34
7.3 結果分析…………………………………………………………………….35
第八章 解論與未來工作..…………………………………………………………37
參考文獻……………………………………………………………………………..38
附錄一 要求迷你時槽分配訊息元素……………………………………………41
附錄二 要求迷你時槽競爭回饋元素……………………………………………43
附錄 三 ATM 協定資料單元…………………………………………………….45
附錄 四 第一次要求傳輸Adaptive p-Persistence 競爭解決演算法……………..47
圖目錄
圖2-1 有線電視網路架構……………………………………………………..3
圖2-2 樹狀分枝HFC 網路……………………………………………………4
圖2-3 上行與下行頻譜分配…………………………………………………..4
圖2-4 RTP……………………………………………………………………...6
圖2-5 碰撞解決………………………………………………………………10
圖2-6 MCNS 架構圖………………………………………………………...12
圖3-1 802.14 邏輯架構圖…………………………………………………...17
圖3-2 802.14 訊框…………………………………………………………...17
圖3-3 802.14 頻道存取……………………………………………………...17
圖3-4 碰撞節決例子…………………………………………………………20
圖4-1 訊框格式………………………………………………………………22
圖4-2 分流概念………………………………………………………………22
圖4-3 優先權式競爭時槽碰撞解決…………………………………………23
圖5-1 答應資料元素格式……………………………………………………29
圖5-2 802.14與加強802.14 比較…………………………………………..30
圖6-1 協定比較………………………………………………………………32
圖7-1 不區分優先權模擬結果………………………………………………34
圖7-2 有區分優先權模擬結果………………………………………………34
圖附一 要求迷你時槽分配訊息元素格式……………………………………40
圖附二 要求迷你時槽競爭回饋元素格式……………………………………42
圖附三 ATM 協定資料單元格式…………………………………………….44
表目錄
表附一 要求迷你時槽分配訊息元素……………………………………..….41
表附二 RMS Group Descriptor Fields(RQ>0)………………………………...41
表附三 RMS Group Descriptor Fields(RQ=0)………………………………...41
表附四 要求迷你時槽競爭回饋元素格式……………………………………43
表附五 Feedback Descriptor Formats………………………………………….43

[1] MCNS Holdings L.P.,Data-Over-Cable Service Interface Specifications, Radio Frequency Interface Specification,SP-RFIv1.1-I01-990311,March 1999
[2] IEEE 802.14 Working Group,Media Access Control ,IEEE Draft Std.802.14,Draft3 R1, Augest 1998.
[3] Mark D.Corner,Nada Golmie,Jorg Liebeherr,and David H.Su,National Institute of Standards and Technology,”A Priority Scheme for the IEEE 802.14 MAC Protocol for Hybrid Fiber-Coax Networks”
[4] Chatschik,Biddikian,IBM Research Division,Bill McNeil,Rob Norman and Ray Zeisz,IBM Corporation ,”MLAP:A MAC Level Access Protocol for the HFC 802.14 Network”,IEEE Communication Magazine ,March 1996,pp 114-120
[5] J.E.Dail et al .,”Adaptive Digital Access Protocol: A MAC Protocol for Multiservice Broadband Access Networks “,IEEE Communication Magazine,Mar 1996 ,pp 104-113
[6] Enrique j.Hernandez-Valencia, Bell aboratories , USA , ”Architectures for Broadband Residential IP Services Over CATV Networks ”,IEEE Network,January/February 1997,pp 36-43
[7] Ying-Dar Lin,Chia-Jen Wu,and Wei-Ming Yin,National Chiao Tung University , ” PCUP:Pipelined Cyclic Upstream Protocol Over Hybrid Fiber Coax”,IEEE Networks January/February 1997,pp 24-34
[8] Nada Golmie,Sandrine Masson and David Su National Institute of Standard and Technology, Gaithersburg,Maryland 20899,USA,”New Packet Admittance Polices for IEEE 802.14 MAC Protocol”
[9] Nada Golmie,Yves Saintillan,and David H.Su National Institute of Standard and Technology”A Review of Contention Resolution Algorithms for IEEE 802.14 Networks”
[10] Ying-Dar Lin National Chiao Tung University,
Taiwan"On IEEE 802.14 Medium Access Control Protocol "
[11] N.Golmie* F.Mouveaux D.Su,National Institude of Standard and Technology"A Comparison of MAC Protocol for Hybrid Fiber/Coax Networks : IEEE 802.14 vs MCNS"
[12] Nada Golmie,Sandrine Masson,Gerard Pieris and David Su,NIST,"Performance evaluation of MAC Protocol components for HFC networks"
[13] John O. Limb,Fellow,IEEE and Dolors Sala, Student Member ,IEEE"A Protocol for Efficient Transfer of Data Over Hybrid Fiber/Coax System"
[14] Sriam,P."Adaptive digital access protocol(ADAPt):A MAC protocol for multisercvices broadband access networks."Contribution number IEEE 802.14-95/142,November 1995.
[15] R.Citta et.al.,”Phase 2 Simulation Reluts for Adaptive Random Access Protocol,”contr.no.IEEE802.14-96/114
[16] ATM Formum,"Traffic .management specification ,draft version 4.0"
[17] ITU-T Recommendation I.361 and I.371
[18] Mark Corner , Jorg Liebeherr,"Contention Resolution Schemes for 802.14 HFC Networks : A Comparative Evaluation" September 23,1996
[19] Dolors Sala,John O.Limb, Sunil Khaunte"Adaptive MAC Protocol for a Cable Modem",http://www.cc.gatech.edu/tech_reports/
[20] Nada Golmie,David Su,Sandrine Masson and Gerard Pieris,National Institute of Standards and Technology ,Gaithersburg , MD 20899 , "Simulation Evaluation of the MAC Convergence Proposal"
[21] Nada Golmie,David Su,Sandrine Masson and Gerard Pieris,National Institute of Standards and Technology ,Gaithersburg , MD 20899 , "Improving the Effectiveness of ATM Traffic Control over Hybrid Fiber-Coax Networks"