隨著通訊網路技術的快速發展，越來越多的通訊設備，包括手機、PDA、Notebook…等，都具備了可以連結上網的功能，而為了達到Anytime、Anywhere的隨時上線(Always on Line)的目標，在3G網路中對於移動性的支援將會是一個重要的議題。而移動性不只存在於核心網路，也存在於無線網路中。
在最近幾年來，有許多的研究和討論關於Mobile IPv6(MIPv6)，而Mobile Node(MN)在各個不同網路之間的換手延遲，更是值得被探討的問題，在MIPv6換手的過程中造成延遲的原因有三個，移動的偵測(Movement Detection)、重複位址檢測Duplicate Address Detection(DAD)、註冊更新Binding Update(BU)、其中DAD所花費的時間更是造成MIPv6換手延遲的主要原因。這個時間對於即時性的運用是非常大的延遲時間。
此外，在先前的文獻中並沒有深入探討關於在重複位址檢測的過程中，如果產生的轉送位址Care of Address(CoA)已經被其他的節點使用的話，該怎麼重組一個CoA，以及接下來的換手流程，怎麼產生一個確保獨一無二的CoA使得在換手時能夠更快速，減少換手延遲，避免封包的遺失。如果沒有一個機制去應對這樣的情形，會使得MN在換手時造成更大的延遲時間以及更多封包的遺失。
因此本論文提出了快速重新組成位址機制Fast-Reconfigure Address Mechanism (F-RAM)，使得產生的CoA如果有重複的話可以迅速產生一個確保獨一無二的CoA。避免有二次重複的情形發生。我們考慮了如果位址有重複的情形下，該如何快速的重組一個CoA，使換手的流程並不會因為位址的重複造成更大的延遲時間。我們的實驗結果顯示我們的方法在遇到位址重複的情況時，確實可以減少換手的延遲時間。

Recently, there have been a lot of research about Mobile IPv6(MIPv6).Mobile Node (MN) in the handover delay between different network is the issue which should be investigated . 
In the MIPv6 handoff delay caused during the three reasons, 1.Movement Detection 2.Duplicate Address Detection (DAD) 3.Binding Update (BU). DAD which time spent is mainly caused by MIPv6 handover delay. This time for real time use is a very big delay.
In addition, in the previous literature did not explore in depth on the duplicate address detection process, if the Care of Address (CoA) has been the other nodes used, how to reconfigure a CoA and then the hanover process, how to generate a unique CoA made to ensure that when the handover can be more quickly and reduce the handoff delay to avoid packet loss. If there is no mechanism to deal with such situations, would make even greater when the MN in the handover latency and packet loss.
Our approach is based on (Hierarchical Mobile IPv6) HMIPv6 architecture. We establish an address table in the Mobility Anchor Point (MAP). The address table will store all access to the network address information. When MN access to the new network will creates a nCoA, and then you can confirm whether this nCoA are unique by address table. So, our approach does not have to perform DAD, just have to confirm whether nCoA unique in the address table. If there is duplication, then we must start the F-RAM mechanism for the MN to re-configure a nCoA and to ensure the nCoA is unique
Therefore, this paper presents a Fast-Reconfigure Address Mechanism (F-RAM).If the CoA duplicate, it Can quickly generate a unique CoA to avoid a second duplication occurred. We consider that if there is duplication address, how to quickly reconfigure a unique address. So that the handover process will not cause even greater delay time when duplicate address occur. Our results show that our propose scheme in case of duplicate address, the exact time can reduce the handover delay

第一章  緒論	- 1 -
1.1	前言	- 1 -
1.2	動機與目的	- 2 -
1.3	論文章節架構	- 4 -
第二章  背景知識與相關研究	- 6 -
2.1	行動式IPv6(Mobile IPv6, MIPv6)	- 6 -
2.1.1	Mobile IPv6之介紹	- 6 -
2.2	Mobile IPv6 的延遲時間	- 10 -
2.2.1	重複位址檢測(Duplicate Address Detection, DAD)	- 11 -
2.3	相關研究	- 13 -
2.3.1  最佳化重複位址檢測(Optimistic DAD )	- 14 -
2.3.2快速換手行動IPv6 (Fast handover MIPv6, FMIPv6)	- 14 -
第三章  新的換手策略架構於HMIPv6	- 17 -
3.1 階層式行動IPv6(Hierarchical Mobile IPv6,HMIPv6)	- 17 -
3.2	DAD問題討論	- 21 -
3.3	MAP ADDRESS TABLE OPERATION	- 23 -
3.4	本文所提出的換手流程	- 24 -
3.5	快速重新組成位址機制(F-RAM)	- 26 -
第四章  模擬結果與討論	- 30 -
4.1	換手延遲時間分析	- 30 -
4.2	模擬環境以及參數	- 32 -
4.2.1實驗1	- 33 -
4.2.2實驗2	- 40 -
第五章  結論與未來展望	- 44 -
參考文獻	- 46 -
圖目錄
圖2.1 MIPv6示意圖	- 7 -
圖2.2 路由最佳化	- 9 -
圖2.3 Mobile IPv6的換手延遲時間	- 10 -
圖2.4 DAD執行流程	- 13 -
圖2.5 FMIPv6換手流程圖	- 16 -
圖3.1 HMIPv6架構圖	- 19 -
圖3.2本文基於HMIPv6所提出的網路環境	- 21 -
圖3.3基於HMIPv6所提出新的換手流程	- 24 -
圖3.4產生的新轉送位址(nCoA)	- 26 -
圖3.5重新組成後的新轉送位址nCoA	- 27 -
圖3.6快速重組位址機制流程圖	- 28 -
圖4.1實驗1的模擬環境	- 33 -
圖4.2在理想狀況下MN的換手延遲時間	- 36 -
圖4.3當有重複位址發生時MN的換手延遲時間	- 37 -
圖4.4重複位址的個數VS換手延遲時間	- 38 -
圖4.5發生重複位址的機率	- 40 -
圖4.6 實驗2模擬環境	- 41 -
圖4.7 理想情況下MN的換手延遲時間	- 42 -
圖4.8 當有重複位址發生時MN的換手延遲時間	- 43 -
表目錄
表4.1 模擬參數	-35-

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