在NCTUns平台上模擬IEEE 802.16e Mobile WiMAX網路

Abstract

IEEE 802.16 (WiMAX)是目前最被看好的無線寬頻網路存取技術之一，可解決傳統固接網路”最後一哩”的問題，並由Intel、Nokia等廠商主導推廣，預期將成為下一代的通訊技術主流。從2001年以來，為WiMAX網路所設計的標準，包括802.16、802.16a、802.16d、802.16e…等。其中，2005年所提出的802.16e標準裡，支援移動式的存取方式，並提供多種媒體存取控制層的換手機制，讓MS (Mobile Station)可以在移動過程中維持網路通訊。另外，在實體層的調變部份，此標準採用OFDMA規範，提供更有彈性的頻寬配置方式。 在本篇論文中，我們在NCTUns網路模擬器裡開發IEEE 802.16e模組，且提供兩種新的節點，分別是BS (Base Station)與MS，供使用者方便建構IEEE 802.16e網路拓樸。另外，在媒體存取控制層，我們的模組支援硬式換手的機制與服務；而實體層的部份，則是採用OFDMA的規範來設計。根據我們的模組實作，研究者可以方便地使用模擬來進行他們的研究。

The IEEE 802.16 (WiMAX) standard, supported by several companies like Intel and Nokia, is one of the most popular technologies for broadband wireless accesses. It solves the last-mile problem with traditional wired networks and is expected to be the mainstream of the next-generation communication technology. The related specifications, such as 802.16, 802.16a, 802.16d, 802.16e, etc., are designed for WiMAX networks from 2001. Among these standards, the IEEE 802.16e provides mobility capabilities. It defines many kinds of MAC layer handover mechanisms so that the MSs (Mobile Stations) can retain connections when they perform roaming. Furthermore, at the physical layer, it uses the OFDMA technology to allow more flexible bandwidth allocation. In this thesis, we develop the IEEE 802.16e protocol modules on NCTUns network simulator. In our design, we add BS (Base Station) and MS nodes, which can conveniently help users to construct IEEE 802.16e network topologies. In addition, our modules support hard handover services at the MAC layer and use the OFDMA technology at the physical layer. Based on our work, researchers can easily use simulations to perform their studies and save much experimental time.