本文為在行動網路上之預先註冊之快速換手階層化行動式IPv6研究，行 動式IPv6可以整合快速換手行動式IPv6及階層化行動式IPv6來分別得到這兩 種方式的好處，快速換手行動式IPv6的好處為讓行動節點換手時擁有較低的 換手延遲，而階層化行動式IPv6則是可以透過使用行動錨點來減少換手控制 訊號的個數，但是快速行動式IPv6會產生TCP序號錯亂的問題而有待解決。 本文描述預先註冊之快速換手階層化行動式IPv6搭配動態控制機制如何去避 免在階層化行動式IPv6上之快速換手行動式IPv6在速度快的情形下封包掉落 的情形發生及降低快速行動式IPv6所產生TCP序號錯亂的機率。預先註冊之快 速換手階層化行動式IPv6使用動態控制機制的動態配置暫存器空間和動態調 整延遲時間來同時達成預先註冊及快速換手的效果。而本文模擬結果顯示本 文提出的方法可以確實改善TCP序號錯亂的問題、減少換手延遲和延遲時間對 行動節點的影響。 This paper addresses the scheme of Anticipatory Registration and Fast Handovers for Hierarchical Mobile IPv6 (AFHMIPv6) in the mobile networks. The performance of MIPv6 mobility could be further enhanced by combining both of FMIPv6 and HMIPv6. The advantage of combining FMIPv6 and HMIPv6 is that the overall handover latency of traditional FMIPv6 can be more reduced through the use of Mobile Anchor Points (MAP) in HMIPv6. Furthermore, a great amount of signaling among MN, CN and HA can also be reduced. However, there remains the problem of sequence disruption (i.e., out of sequence) in TCP streams that needs to be solved. The proposed AFHMIPv6 scheme overcomes the above problem by dynamically adjusting Buffer Space and dynamically adjusting delay timer of FMIPv6 for HMIPv6. In AFHMIPv6, the fast local binding update message is applied to achieve packet loss condition and reduce out-of sequence probability. Our simulation results show that the proposed scheme can effectively improve the out of sequence problem, reduce handover latency and MN idle time in mobile IPv6 network.
