在 NCTUns 平台上模擬 WiMAX 網狀網路

Abstract

IEEE 802.16 (也稱為WiMAX) 是一個前景看好的固定式寬頻無線接取系統的標準，在這個標準之中，制定了兩種運作模式。第一種是點對多點模式，用以取代傳統固接式有線的「最後一哩」技術；第二種是網狀模式，適用於下一世代的無線都會型區域網路。與傳統的 IEEE 802.11 網狀網路相比，IEEE 802.16 網狀網路提供了更高的可用頻寬及更大的涵蓋範圍。在 WiMAX 網路上有諸多研究議題，如服務品質 (Quality of Service)、空間再利用 (spatial reuse) 及網路效能等。然而，目前仍然沒有一個公開的網路模擬器可以支援 WiMAX 網路的模擬。在這篇論文中，我們在NCTUns網路模擬器上設計及實作了一個 WiMAX 網狀網路的模擬系統，其所提供的功能經過了驗證。我們評估了在不同的模擬環境下的網路效能，並且討論系統的可擴充性及未來的發展方向。

The IEEE 802.16d standard (also known as WiMAX) is a promising technology for future fixed broadband wireless access (FBWA) systems. There are two operation modes defined in this standard. First, the point-to-multipoint (PMP) mode aims to replace the traditional wired last-mile solutions. Second, the Mesh mode is designed for the next-generation wireless metropolitan area networks (Wireless-MANs). Compared with the traditional 802.11-based mesh network, the 802.16 Mesh network provides higher throughput and larger coverage.

Many critical issues of WiMAX networks such as quality of service (QoS), spatial reuse, and network performance are being broadly studied by researchers. However, there is still no general-purposed and publicly available network simulators for WiMAX networks.

In this thesis, we design and implement a WiMAX Mesh simulation system over the NCTUns network simulator. Functionalities of our implementation are validated. We evaluate the performance of WiMAX Mesh networks under different conditions. Scalability issues are also discussed. Finally, possible future developments are proposed.