臺灣博碩士論文加值系統

本論文主要是探討WCDMA（寬頻分碼多工存取）與無線區域網路(Wireless LAN)之異質網路之垂直換手(Vertical Handoff)機制之效能，我們比較了固定式磁滯值(Fixed Hysteresis)垂直換手以及適應性磁滯值(Adaptive Hysteresis)垂直換手之效能。此外，我們進一步將頻寬分區，並且針對不同速度以及依據使用者不同需求來做頻寬的分配，由模擬結果可知，雖然固定式磁滯值垂直換手可降低乒乓(Ping-Pong)效應影響，但也使得系統流量受到影響；而適應性磁滯垂直換手不只降低乒乓效應，也能提升整體系統流量。

This thesis explores the performance of adaptive vertical handoff schemes for overlaid WCDMA and wireless LAN (WLAN) heterogeneous networks. We propose an adaptive hysteresis vertical handoff scheme to effectively adjust the hysteresis to compromise the handoff rate and bandwidth. Simulation results show that the proposed Adaptive hysteresis Vertical (AHYV) handoff scheme can increase lots of average data rate than the fixed hysteresis vertical handoff scheme. Furthermore, with quality of service (QoS), we model three service by video, talk and internet services. Moreover, for three type mobility users with0, 10 and 60(km/hr), we design QoS based AHYV (QAHYV) schemes to compromise the handoff rate and system bandwidth. Simulation results show that the proposed QAHYV can not only reduce the handoff rate but also maintain the demanded QoS bandwidth for different mobile users.

中文摘要 I
Abstract II
致謝 III
目 錄 IV
圖 目 錄 VII
表 目 錄 IX
第一章 前言 1
1.1 研究背景 1
1.2 研究動機及目的 4
1.3 論文架構 5
第二章 網路原理與系統模型 7
2.1 行動通訊發展概況 7
2.2 無線通訊網路特性 12
2.3 無線傳輸的路徑損失特性 13
2.3.1 傳播路徑損耗模型(Propagation Path Loss Model) 15
2.3.2 大尺度傳播模型(Large Scale Propagation Model) 17
2.3.3 小尺度傳播模型(Small Scale Propagation Model) 17
2.3.4 多重路徑傳播效應(Multi-Path Propagation Effect) 19
2.4 垂直換手(Vertical Handoff)程序 19
2.4.1 換手判斷機制 21
第三章 異質網路之垂直換手 25
3.1 異質性網路模型與架構 25
3.2 固定式磁滯值垂直換手 25
3.3 適應性磁滯值垂直換手 27
3.4 電腦模擬結果與討論 28
3.5 小結 35
第四章 頻寬分區之垂直換手 36
4.1 WLAN與WCDMA異質網路模型與架構 36
4.2 固定式磁滯值垂直換手 38
4.3 適應性磁滯值垂直換手 39
4.4 電腦模擬結果與討論 41
4.5 小結 47
第五章 基於QoS頻寬分配之垂直換手 48
5.1 WLAN與WCDMA異質網路模型與架構 48
5.2 固定式磁滯值垂直換手 50
5.3 適應性磁滯垂直換手 53
5.4 基於總頻寬之垂直換手 55
5.5 電腦模擬結果與討論 56
5.6 小結 65
第六章 結論 66
參 考 文 獻 67
圖2.1 無線區域網路架構圖 13
圖2.2 電磁波傳播距離與訊號強度關係 18
圖2.3 接收端受到多重路徑效應影響示意圖 19
圖2.4 換手過程 20
圖2.5 換手機制作為換手方式 23
圖3.1異質網路示意圖 25
圖3.2異質網路之模擬環境 30
圖3.3固定磁滯值與適應性磁滯值換手率之效能比較 31
圖3.4固定磁滯值與適應性磁滯值之乒乓換手率效能比較 32
圖3.5平均流量之效能比較 33
圖3.6不同的γ值之換手率效能比較 33
圖3.7不同的σ值之換手率效能比較 34
圖3.8不同的β值之換手率效能比較 35
圖4.1頻寬分區模型 37
圖4.2 WLAN重疊WCDMA網路之模擬環境 42
圖4.3單一AP換手前與換手後傳輸率之比較，h=0 42
圖4.4單一AP區域在AP或WCDMA行動台數之比較 44
圖4.5固定式與適應性垂直換手之平均傳輸率比較，h=0 45
圖4.6 固定式與適應性垂直換手之平均傳輸率比較，h=20 45
圖4.7 固定式與適應性垂直換手之平均傳輸率比較，h=0-100 46
圖4.8 固定式與適應性垂直換手之換手率比較，h=0-100 47
圖5.1 WLAN與WCDMA異質性網路環境 56
圖5.2 行動服務為視訊之平均傳輸率比較 58
圖5.3 行動服務為通話之平均傳輸率比較 58
圖5.4 行動服務為上網之平均傳輸率比較，V=0，10 59
圖5.5 行動服務為上網之平均傳輸率比較，V=60 60
圖5.6 行動服務為通話之換手率比較，V=10，60 61
圖5.7 行動服務為上網之換手率比較，V=10 62
圖5.8 行動服務為上網之換手率比較，V=60 62
圖5.9 基於總頻寬與固定式垂直換手之平均傳輸率比較，V=0 63
圖5.10 基於總頻寬與固定式垂直換手之平均傳輸率比較，V=10 64
圖5.11 基於總頻寬與固定式垂直換手之平均傳輸率比較，V=60 65
表2.1各種環境中的n值 16
表3.1異質網路環境模擬參數 29
表4.1 WLAN重疊WCDMA網路之模擬參數 43
表5.1 WLAN與WCDMA異質性網路之模擬參數 57

[1]T.S. Rappaport, “Wireless Communication: Principles and Practice,” Prentice Hall, 1996.
[2]G. P. Pollini, “Trends in Handover Design,” IEEE Communications Magazine, Vol. 34, pp. 82-90, March. 1996.
[3]M. Ylianttila, R. Pichna, J. Vallstram, J. Makela, A. Zahedi, P. Krishnamurthy, and K. Pahlavan, “Handoff Procedure for Heterogeneous Wireless Networks,” Proceedings of IEEE Global Telecommunications Conference(GLOBECOM’99), Vol. 5, pp. 2783-2787, Dec. 1999.
[4]Q-A. Zeng and D. P. Agrawal, ”Modeling and Efficient Handling of Handoffs in Integrated Wireless Mobile Networks,” IEEE Transactions on Vehicular Technology, Vol. 51, pp. 1469-1478, Nov. 2002.
[5]K.S. Jang, J.S. Kim, D.R. Shin, “A Novel Vertical Handoff Strategy for Integrated IEEE 802.11 WLAN/CDMA Networks,” Proceedings of the Fourth Annual ACIS, pp. 616-621, 2005.
[6]K.-I. Itoh, S. Watanabe, J.-S. Shih and T. Sato, “Performance of Handoff Algorithm Based on Distance and RSSI Measurements,” IEEE Transactions on Vehicular Technology, Vol. 51, pp. 1460-1468, Nov. 2002.
[7]Z. Huamin and K.-S. Kwak, “Adaptive Handoff Using Distance Information,” Proceedings of IEEE Vehicular Technology Conference, Vol. 2, pp. 932-936, May 2006.
[8]D. K. Panwar and L. Shyam, “Coverage Analysis of Handoff Algorithm with Adaptive Hysteresis Margin,” Proceedings of 10th International Conference on Information Technology Conference, pp. 133-138, Dec. 2007.
[9]A. H. Zahran, B. Liang and A. Saleh, “Signal Thresholds Adaptation for Vertical Handoff in Heterogeneous Wireless Networks,” Mobile Networks and Applications, Springer Netherlands, Vol. 11, No. 4, pp. 625-640, August 2006.
[10]N. Nasser, and H. Hassanein, “Bandwidth Reservation Policy for Multimedia Wireless Cellular Networks and Its Analysis,” IEEE Communications Magazine, Vol. 5, pp. 3030-3034, Jun. 2004.
[11]L. Hsu, R. Purnadi and S.S.P, “Maintaining quality of Service (QoS) During Handoff in Cellular System with Movement Prediction Schemes,” Proceedings of IEEE Vehicular Technology Conference, Vol. 4, pp. 2153-2157, Fall. 1999.
[12]I.Nomay and J. Dunham, “AVL Based Virtual Destination Handoff Algorithm,” Proceedings of IEEE Vehicular Technology Conference, Vol. 2, pp. 1599-1603, Jul 1999.
[13]L. Dongyeon, H. Youngnam and H. Jinyup, “QoS-Based Vertical Handoff Decision Algorithm in Heterogeneous Systems,” Proceedings of IEEE International Symposium on Personal, indoor and Mobile Radio Communications, pp. 1-5, Sept. 2006.
[14]R. Tawil, G. Pujolle and O. Salazar, “A Vertical Handoff Decision Scheme in Heterogeneous Wireless Systems,” Proceedings of IEEE Vehicular Technology Conference, pp.2626-2630, May 2008.
[15]W. Stallings, Wireless Communication & Networks, 2nd Edition, Prentice Hall, 2005.
[16]R. Vijayan and J. Holtzman, “A Model for Analyzing Handoff Algorithms,” IEEE Transactions on Vehicular Technology, Vol. 42, pp. 351–356, Aug. 1993.
[17]M. Zonoozi, P. Dassanayake, and M. Faulkner, “Optimum Hysteresis Level, Signal Averaging Time and Handover Delay,” Proceedings of IEEE Vehicular Technology Conference, pp. 310–313, May 1997.
[18]G. Senarath, A. Abu-Dayya and R.Matyas, “Adaptive Handoff Algorithms Using Absolute and Relative Thresholds for Cellular Mobile Communication Systems,” Proceedings of IEEE Vehicular Technology Conference, Vol. 2, pp. 1603-1607, May 1998.
[19]M. Ylianttila, M. Pande, J. Makela, and P. Mahonen, “Optimization Scheme for Mobile Users Performing Vertical Handoffs between IEEE 802.11b and GPRS/EDGE Networks,” Proceedings of IEEE Global Telecommunications Conference, Vol. 6, pp. 3439-3848, June. 2004.
[20]F. Zhu and J. Mcnair, “Optimizations for Vertical Handoff Decision Algorithms,” Proceedings of the Wireless Communications and Networking Conference (WCNC 2004), Vol. 2, pp. 867-872, March 2004.
[21]W.-T. Chen, J.-C. Liu, H.-K. Huang, “An Adaptive Scheme for Vertical Handoff in Wireless Overlay Networks,” Proceedings of the 10th International Conference on Parallel and Distributed Systems (ICPADS), pp. 541-548, Jul. 2004.
[22]J.-Y. Pyun, “Context-Aware Streaming Video System for Vertical Handover over Wireless Overlay Network,” IEEE Transactions on Consumer Electronics, Vol. 54, pp. 71-79, Feb. 2008.
[23]K. Yang, I. Gondal, B. Qiu and L. S. Dooley, “Combined SINR Based Vertical Handoff Algorithm for Next Generation Heterogeneous Wireless Networks,” Proceedings of IEEE Global Telecommunications Conference, Washington, pp. 4483-4487, Dec. 2007.
[24]S.-H. Wie, J.-S. Jang, B.-C. Shin and D.-H. Cho, “Handoff Analysis of the Hierarchical Cellular System,” IEEE Transactions on Vehicular Technology, Vol. 49, pp. 2027-2036, Sept. 2000.
[25]B. Sklar, Digital Communication Fundamentals and Application, Prentice Hall, 2002.
[26]Vijay K. Garg and Joseph E. Wilkes, Wireless and Personal Communications Systems, Prentice Hall Inc. 1996.
[27]F. Graziosi and F. Santucci, “A General Correlation Model for Shadow Fading in Mobile Radio Systems,” IEEE Communications Letters, Vol. 6, pp. 102 – 104, March 2002.
[28]M. Ruggieri, F. Graziosi and F. Santucci, “Modeling of the Handover Dwell Time in Cellular Mobile Communications Systems,” IEEE Transactions on Vehicular Technology, Vol. 47, No. 2, pp. 489-498, May. 1998.
[29]鄭同伯，WLAN無線網路系統剖析與應用，博碩文化，2003，台北。
[30]A.E. Xhafa and O.K. Tonguz, “Handover Performance of Priority Schemes in Cellular Networks” IEEE Transactions on Vehicular Technology, Vol. 57, pp. 565-577, Jan. 2008.
[31]K.S. Jang, J.S. Kim, D.R. Shin, “A Novel Vertical Handoff Strategy for Integrated IEEE 802.11 WLAN/CDMA Networks,” Proceedings of the Fourth Annual ACIS, pp.616-621, Sept.2005.
[32]M. Ruggieri, F. Graziosi and F. Santucci, “Modeling of the Handover Dwell Time in Cellular Mobile Communications Systems,” IEEE Transactions on Vehicular Technology, Vol. 47, No. 2, pp. 489-498, May. 1998.
[33]S.T. Sheu and C.C. Wu, “Using Grey Prediction Theory to Reduce Handoff Overhead in Cellular Communication Systems” Proceedings of IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Vol. 2, pp.782 – 786, Sept. 2000.
[34]B-J. Chang, J-F. Chen, “Cross-Layer-Based Adaptive Vertical Handoff with Predictive RSS in Heterogeneous Wireless Networks,” IEEE Transactions on Vehicular Technology, Vol. 57, pp. 3679 -3692, Nov. 2008.
[35]R. Corvaja, “Qos Analysis in Overlay Bluetooth-WiFi Networks with Profile-Based Vertical Handover,” IEEE Transactions on Mobile Computing, Vol. 5, pp. 1679-1690, Dec. 2006.