臺灣博碩士論文加值系統

目前無線通訊所廣泛使用的GSM系統，由於採用線路交換(circuit switching)的方式，使用者在連線期間，系統保留固定的頻寬給他使用，此頻寬由此使用者獨佔，不能讓其他使用者分享，如此雖可保障服務品質，但也因此使得可同時上線服務的使用者有限，且頻寬效能的利用率很低，在無線傳輸需求日益增多的情況下，愈顯其需解決之處。因此，本論文試圖發展一個模擬環境，提出一套排程方式，採用分時多工(TDMA ; Time Division Multiple Access)並配合分封交換(packet switching)的方式來增加系統頻寬利用率，並增加同時上線人數。
在無線環境中，一般來說通道品質並不是很好，重傳封包在通道品質很差之下，對於效能的影響不小，在本論文中也對此現象做一模擬，並提出解決的方法。

The most widely used GSM wireless transmission system, which adopts circuit switching that reserves bandwidth for the users to guarantee QoS and no other users are allowed to share the reserved bandwidth, has currently faced a problem of running short of bandwidth and not being able to support more people on line at the same time because of the growing demand for wireless communication. In this paper, we propose a simulation environment and scheduling algorithm using TDMA and packet switching method to improve these problems.
Generally speaking, in the wireless transmission environment, the channel quality is not always good. The retransmission packets will have a negative influence on the bandwidth utilization and calls complete rate. In this paper, we will simulate this case and propose a method to solve it.

目錄
圖目錄---------------------------------------------------------V
表目錄-------------------------------------------------------VII
第一章 緒論---------------------------------------------------1
1.1 ATM網路與行動通訊之結合-----------------------------------1
1.2 研究動機與方向--------------------------------------------3
1.3 章節概要----------------------------------------------4
第二章 無線非同步傳輸模式的架構--------------------------------5
2.1 使用環境簡介----------------------------------------------5
2.2 無線非同步傳送模式參考模型---------------------------------6
2.3 無線非同步傳輸模式設計概念---------------------------------8
2.3.1 無線電存取層------------------------------------9
2.3.2 行動ATM----------------------------------------11
第三章 網路模型及系統運作方式---------------------------------14
3.1 模擬環境之簡介---------------------------------------14
3.1.1網路的架構--------------------------------------14
3.2 系統運作方式----------------------------------------------20
3.2.1 呼叫與資料產生方式-----------------------------20
3.2.2 競爭時槽方式-----------------------------------21
3.2.3 排程演算法-------------------------------------21
3.2.4 錯誤更正方式-----------------------------------28
第四章 模擬結果及分析-----------------------------------------31
4.1 依到達交通流量密度分析比較--------------------------------31
4.2 動態調整錯誤更正方式的效果--------------------------------37
4.3 封包格式--------------------------------------------------42
第五章 綜合分析與結論-----------------------------------------43
參考文獻------------------------------------------------------44
圖目錄
圖1-1 ATM網路架構-----------------------------------------------------------2
圖2-1 WATM參考模型---------------------------------------------------------7
圖2-2 WATM 協定堆疊--------------------------------------------------------8
圖3-1 WATM簡單架構--------------------------------------------------------14
圖3-2 訊框格式-----------------------------------------------------------------16
圖3-3 採用ARQ的時槽格式------------------------------------------------17
圖3-4 採用FEC的時槽格式-------------------------------------------------18
圖3-5 影像相鄰封包間隔時間圖--------------------------------------------22
圖3-6 語音相鄰封包間隔時間圖--------------------------------------------23
圖3-7 語音相鄰封包可容忍間隔時間--------------------------------------24
圖4-1語音交通斷線率的比較-----------------------------------------------34
圖4-2影像交通斷線率的比較-----------------------------------------------34
圖4-3數據交通斷線率的比較-----------------------------------------------35
圖4-4語音交通成功傳送數的比較-----------------------------------------35
圖4-5影像交通成功傳送數的比較-----------------------------------------36
圖4-6數據交通成功傳送數的比較-----------------------------------------36
圖4-7時槽利用率的比較-----------------------------------------------------37
圖4-8 成功傳送語音資料數(在不同的channel ber下)-----------------38
圖4-9成功傳送的影像資料數(在不同的通道環境下)------------------38
圖4-10 成功傳送的數據資料數(在不同的通道環境下)----------------39
圖4-11 有效時槽利用率(在不同的通道環境下)-------------------------39
圖4-12 語音資料逾時率(在不同通到環境下)----------------------------40
圖4-13影像資料逾時率(在不同通道環境下)-----------------------------40
圖4-14 數據資料逾時率(在不同通道環境下)----------------------------41
表目錄
表2-1 實體層設計方式表-----------------------------------------------------10
表3-1 Numerical Values for the Speech Activity Model-------------------15
表3-2 BCH碼多項式產生器--------------------------------------------------20
表3-3 BCH縮短碼多項式產生器--------------------------------------------20
表3-4 排程表--------------------------------------------------------------------27
表3-5 FEC等級表---------------------------------------------------------------30
表4-1 數據資料錯誤更正方式表--------------------------------------------42
表4-2 語音資料錯誤更正方式表--------------------------------------------42
表4-3 影像資料錯誤更正方式表--------------------------------------------42
表5-1各演算法的綜合比較---------------------------------------------------43

1. Atsushi OHTA, Masafumi YOSHIOKA, Takatoshi SUGIYAMA and
Masahiro UMEHIRA, “PRIME ARQ:A Novel ARQ Scheme for High-
speed Wireless ATM- Design, implementation and
formanceevaluation-”, IEEE Communications Magazine, Sept.
1998, pp.1128-1134.
2. Doo Seop EOM, Student Member, Masashi SUGANO, Masayuki
MURATA, and Hideo MIYAHARA, Members, “Combination Scheme of
ARQ and FEC Multimedia Wireless ATM Networks”, IEICE Trans.
Commnu., VOL.ES1-B, NO.5, MAY 1998, pp.1016-1024.
3. J. Deane, “WATM MAC requirements”, ATM Forum/96-0786,
June 1996.
4. Satoru Aikawa, Yasushi Motoyama and Masahiro Umehira,
“Forward Error Correction Schemes for Wireless ATM
Systems”, IEEE Personal Communications, Aug. 1996, pp.454-
458.
5. Ian F. Akyildiz and Inwhee Joe, “A New ARQ Protocol for
Wireless ATM Networks”, IEEE/ACM Transactions On
Networking, Vol.7, No.2 April 1998, pp:1109-1206.
6. Ian F. Akyildiz, Fellow, IEEE. David A. Levine and Inwhee
Joe, “A Slotted CDMA Protocol with BER Scheduling for
Wireless Multimedia Networks”, IEEE/ACM Transactions On
Networking, Vol.7, No.2, April 1999, pp.1136-1147.
7. Feher, Applications of Digital Wireless Technologies to
Global Wireless Communications, Prentice Hall, 1997, pp224-
225.
8. Yuji Nakayama and Satoru Aikawa, Member, IEEE, “Cell
Discard and TDMA Synchronization Using FEC in Wireless ATM
Systems”, IEEE Journal On Selected Areas In Communications,
Vol.15, No.1, January 1997, pp.447-459.
9. Sanjiv Nanda, Richard P. Ejzak, Bharat T. Doshi, “A
Retransmission Scheme for Circuit-Mode Data on Wireless
Links”, IEEE Communication Magazine, Aug. 1994, pp:587-599.
10.Theodore S. Rappaport, “Wireless Communications: Principles
And Practice”, Prentice Hall, 1996.
11. M. Zeng, A. Annamalai, and Vijay K. Bhargava, “Recent
Advances in Cellular Wireless Communications”, IEEE
Communications Magazine, Sept. 1999, pp.128-138.
12. Anthony Acampora, “Wireless ATM: A Perspective on Issues
and Prospects”, IEEE Personal Communications, Aug. 1996,
pp.8-17.
13. F. A. Tobagi, “Multiaccess Link Control”, Computer
Network Architectures and Protocols, P. E. Green, Jr., ed.,
New York: Plenum Press, 1982.
14.B. Kraimeche, “Wireless ATM: Current Standards and Issues”,
IEEE Wireless Communications and Networking Conference, 1999,
vol.1,pp.56-60 .
15. Joseph Evans, “Wireless ATM: An Overview”,
http://www.ittc.ukans.edu/~prasiths/WirelessATM/PHY.htm
16. Tero Ojanpera, Ramjee Prasad, “An Overview of Air
Interface Multiple Access For IMT-2000/UMTS”, IEEE
Communication Magazine, Sep. 1998, pp. 82-95.
17. Zhao Liu, Mark J. Karol, Magda El Zarki, and Kai Y. Eng,
“Channel access and interference issues in multi-code DS-
CDMA wireless packet (ATM) networks”,Wireless Networks, 2,
1996, pp. 173-193.