多階層行動式IPv6上快速換手之效能研究

A Study on the Performance of Fast Handoff for Multi-level Hierarchical MIPv6

吳振翔(Chen-Hsiang Wu)

指導教授 ： 劉傳銘

國立臺北科技大學/機電學院/通訊與資訊產業研發碩士專班/碩士(2008年)

摘要

行動式IPv6（MIPv6）是為了解決行動裝置在無線網路環境底下移動的問題，快速換手行動式IPv6（FMIPv6）的優點在於擁有較低的換手延遲，階層化行動式IPv6（HMIPv6）則是可以透過使用行動錨點（MAP）來減少換手控制訊號的個數，進而減少本地伺服器（HA）的負載，但是快速換手行動式IPv6（FMIPv6）會造成TCP序號錯亂的問題，階層化行動式IPv6（HMIPv6）的換手延遲過久且會有封包遺失（packet loss）的問題，而快速換手階層化行動式IPv6（F-HMIPv6）結合二者的優點，可以減少本地伺服器（HA）的負載同時擁有較低的換手延遲，然而快速換手階層化行動式IPv6（F-HMIPv6）在巨觀移動（Macro mobility）的情形下，依然會有TCP序號錯亂的問題，且換手時間也比在微觀移動下要長，本文描述多階層式快速換手MIPv6（MF-HMIPv6）如何減少在快速換手階層化行動式IPv6（F-HMIPv6）在巨觀移動（Macro mobility）中TCP序號錯亂的問題，並且更一步減少換手延遲，而模擬結果顯示本文研究的方法確實可以改善TCP序號錯亂、減少封包遺失（packet loss）和降低換手延遲。

關鍵字

行動式IPv6 ； 快速換手行動式IPv6 ； 階層化行動式IPv6

並列摘要

MIPv6 is to solve the handoff problem when a mobile device moves in a wireless network seamlessly. The advantage of FMIPv6 is low handoff latency. HMIPv6 can reduce handoff time by using MAP and decrease HA loading. However, FMIPv6 has out-of sequence problem in TCP streams. HMIPv6 experiences the long handoff latency and packet loss condition. F-HMIPv6 combines the advantages of both schemes. It can reduce the HA loading and has low handoff latency. Nevertheless, F-HMIPv6 still has the out-of sequence problem on Macro mobility. Handoff time of Macro mobility is longer than micro mobility. This article describes how MF-FMIPv6 reduce out-of sequence problem probability in TCP streams on Macro mobility and reduce handoff latency. The simulation displays the scheme of this article that improve out-of sequence problem in TCP streams, decrease packet loss condition and reduce handoff latency.

並列關鍵字

MIPv6 ； FMIPv6 ； HMIPv6

參考文獻

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[3] R. Koodli, "Fast Handovers for Mobile IPv6," Internet Engineering Task Force RFC4068, July 2005。

[5] D. W. Lee, and J. W. Kim, "Delayed-Duplicated ACK (DDA) Algorithm for TCP Performance Enhancement to Overcome Packet Sequence Disruption in Fast-handoff of Mobile IPv6," Distributed Computing Systems Workshops, 24th International Conference, 2004, pp. 98-103.

[9] R. Hinden, and S. Deering, "Internet Protocol Version 6 (IPv6) Addressing Architecture," Internet Engineering Task Force RFC3513, April 2003.

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