IETF制定了行動式IP與行動式IPv6標準來提供行動力的支援，讓使用者在不同IP網域下漫遊時，仍可維持原通訊。而階層化行動式IPv6則是針對移動式IPv6的缺點所提出的改進方案。藉由在網路中設置移動錨點(Mobility Anchor Point)負責處理移動節點區域性的移動，減少移動節點對本代理伺服器(Home Agent)或對應節點(Correspondent Node)進行註冊的機會，可降低過多的控制訊息在網路上傳送所造成的頻寬浪費，也可降低移動節點換手時的延遲時間。 在本文中所提出的移動錨點選擇機制，主要是在網路中階層化設置移動錨點的環境下，移動節點可針對本身的移動特性，選擇一個最合適的移動錨點。且加入抽象移動錨點(Abstract MAP)的概念，降低移動節點更換移動錨點的機會，減少移動節點重新對本代理伺服器(Home Agent)或對應節點(Correspondent Node)進行註冊所帶來的頻寬浪費和換手延遲。且我們加入負載平衡機制，不會讓負載過於集中於某移動錨點而發生癱瘓。在模擬結果中也顯示，加入抽象移動錨點的確可以縮短換手時的延遲時間，且各移動錨點間的負載也較為分散，但如何建置一個合適的抽象移動錨點，則需考慮網路中移動節點的個數與移動節點的移動特性來決定。 The Mobile IPv4 and Mobile IPv6 were proposed by IETF as the main protocols for supporting IP mobility. Because of some shortcomings of Mobile IPv6, Hierarchical Mobile IPv6 (HMIPv6) has been proposed to minimize the signaling overhead and handover latency by deploying Mobility Anchor Point (MAP) in the network. In this thesis, we proposed a MAP selection algorithm in a network with tree-based hierarchy. Mobile Node (MN) can select an appropriate MAP to register according to its mobility pattern. And we introduce the concept of abstract MAP, it can effectively reduce the frequency of Inter-domain handoff and then to minimize the signaling overhead and handover latency. Additionally, we introduce the load balance mechanism in the abstract MAP to avoid the overload in some MAP. Finally, the performance of the proposed scheme is evaluated through simulation experiments. The simulation results show that our scheme can minimize the handover latency and the load of each MAP node can be more balance. It also shows that the amount of MNs in the network and the mobility pattern of all MNs shall be carefully considered for the achievement of a suitable abstract MAP.
