在WiMAX環境下設計與實作跨越存取服務網路的換手協定

Abstract

近幾年來，WiMAX已經成為下一代無線網路的最佳選擇之一。由於無線網路環境日趨成熟，使得手持式無線裝置日漸增加，而使用者的手持裝置在移動時所產生的換手（Handoff）問題也日漸重要。WiMAX點對點網路架構為WiMAX網路論壇所提出的無線網路架構，在此架構中存取服務網路換手（ASN anchored mobility）與連結服務網路換手（CSN anchored mobility）是WiMAX網路的兩種基本網路換手方法。在本篇論文中，我們針對WiMAX無線網路架構，實作存取服務網路換手的R4換手方法（R4 mobility）與先期建立資料通道方法（Pre-constructing data path）。透過實驗的測量結果顯示透過網路架構（WiMAX End-to-End Network Architecture）的改善能讓換手更具效率亦可以減少換手實的封包遺失及加速換手時間。

In the recently year, the WiMAX becomes one of the most popular solutions for next generation wireless network. With the growth of mobile devices, the handoff issue is a hot topic in the mobility research. The WiMAX End-to-End Network Architecture proposed by WiMAX Forum is a newly architecture of wireless network, and the ASN and CSN anchored mobility are the basic mobility management for WiMAX networks. In this thesis, we implement the R4 mobility and a pre-constructing data path method in WiMAX environment. The handoff packet loss and handoff delay are evaluated in the proposed methods. The numerical results show that the network assisted mobility management can improve the handoff performance and reduce the packet loss.