利用可動態轉向之有向性天線改善IEEE 802.16(d)網狀網路之效能

Abstract

IEEE 802.16(d)網狀網路很有希望成為下一代的無線骨幹網路，在該網路中的節點皆須配備一隻全向性天線（或是由多隻有向性天線所構成的天線陣列）來送收無線訊號。在此網路下，有效發揮有向性天線空間重複利用的特性將會是一個很大的挑戰。

在本篇論文中，相對於原本使用多隻有向性天線所構成的天線陣列去模仿全向性天線的功能，我們提出了一個全新的設計，使得每個網路節點只須配備一隻可動態轉向的有向性天線，我們的設計可以更佳的發揮有向性天線的優勢並且大量減少網路部署的成本。

由我們在媒體存取控制（Media Access Control）層的模擬結果，可以觀察到我們的設計有效的提升可使用之控制頻寬的利用率。另一方面，應用程式所能得到的傳輸流量顯示，我們的設計可以提升整體網路TCP傳輸流量7.506倍以及UDP傳輸流量2.436倍。

The IEEE 802.16(d) mesh network is a promising next-generation wireless backbone network. This network requires that all network nodes should be equipped with an omni-directional antenna (or an directional antenna array emulating it). Exploiting the spatial reuse property of directional antennas in such networks is a great challenge.

In this thesis, instead of collocating directional antennas to emulate omni-directional antennas, we propose a novel design using only one steerable directional antenna for each node. Our design can better exploit the advantages of directional antennas and greatly reduce the deployment cost of the network.

Our MAC-layer simulation results show that our design significantly increases the utilization of the control-plane bandwidth. The application throughput results show that our design can increase the aggregate TCP throughputs by a factor of 7.506 and the aggregate UDP throughputs by a factor of 2.436, respectively.