一個在IEEE 802.16j 行動式中繼站模式上基於網路的快速行動交遞機制

Abstract

近年來無線網路之技術快速的發展，其中之一便是IEEE 802.16 (WiMAX)。在此類無線寬頻系統如此迅速的發展之下，如何在行動all-IP網路服務中達成無接縫的交遞(基地台交換)顯得非常重要。現今的網路IP層交遞機制可分為兩種範疇，其一為基於行動裝置的機制，例如Mobile IPv6 (MIPv6)；其二為基於網路的機制，例如Proxy Mobile IPv6 (PMIPv6)。其中PMIPv6擁有較MIPv6更優良的表現，並很有希望是下一世代行動all-IP網路服務的選擇。然而，在IEEE 802.16j行動式中繼站模式之上，PMIPv6並無法避免封包遺失以及較長的服務中斷時間。因此在這篇論文中，我們提出了一個在IEEE 802.16j行動式中繼站模式之上，基於網路的、並且跨網路分層的行動交遞機制。由於使用新提出的控制訊息還有通道路由器的緩衝暫存功能，所提出的機制可以讓資料聯結層與網路IP層的交遞同時進行，並且避免封包的遺失。最後，數學分析與模擬的結果顯示出本機制在效能表現上有顯著的提升。

Wireless technology, such as IEEE 802.16 (WiMAX), advances quickly in recent years. With the rapid development of broadband wireless access system, how to achieve seamless handover is essential to the all-IP mobile services. Nowadays IP layer handover schemes can be classified into two categories, the host based approach such as Mobile IPv6 (MIPv6), and the network-based approach such as Proxy Mobile IPv6 (PMIPv6). PMIPv6 outperforms MIPv6 and is a promising option for next-generation all-IP mobile networks. However, PMIPv6 may not prevent packet loss and long service disruption time (SDT) problems in IEEE 802.16j mobile relay station (MRS) mode. In this thesis, a network-based cross-layering handover mechanism was proposed for IEEE 802.16j MRS mode. With the newly introduced control message and buffering mechanism in Access Router, the Data-Link layer and IP layer handover are processed concurrently and packet loss is prevented. Finally, both numerical analysis and simulation results show remarkable improvement of performance.