使用事先連結方法的網路啟動行動IP快速換手機制

Abstract

隨著行動即時應用(mobile real-time application)的需求成長，快速換手的效率被視為越來越重要。行動IP快速換手(Mobile IP fast handoff)機制已被標準化以縮短換手延遲。然而在行動IP快速換手機制中，對於高速移動用戶卻無法保證有足夠的時間完成快速換手的程序。事先連結的方法提供此問題一種解決方法。但在其中卻沒有定義如何精準預測事先連結的機制，以及與哪些存取路由器(access router,AR)做連結。 在此論文中，提出一個使用事先連結方法的網路啟動行動IP快速換手(network-initiated early binding fast handoff , NEBFH) 機制以及智慧型存取路由器選擇 (intelligent candidate access router selection, ICARS) 的演算法。由模擬結果，透過事先連結機制與換手結果的關係可以得到較好且精準的事先連結機制。另外，ICARS演算法也降低了選擇錯誤的機率進而改進了換手的延遲。

Since the demand for mobile real-time application grows fast, the handoff efficiency of Mobile IP becomes extraordinarily important. Fast handoff of Mobile IP is standardized to eliminate the handoff delay. Unfortunately, anticipation of fast handoff does not guarantee that mobile node can always have time to exchange messages for fast handoff of those mobile nodes move with high speed. An Early binding method provides a solution to reduce unreliability of anticipation for high speed mode nodes. However, there is no definition how to make an exact early binding event trigger and candidate access router selection. In this thesis, a network-initiated early binding fast handoff (NEBFH) and an intelligent candidate access router selection (ICARS) algorithm were proposed. Simulation results show that the relation of handoff performance and binding event trigger can provide how to make an exact early binding. Moreover, the ICARS algorithm reduces the rate of selection failure and improves the handoff delay.