針對無線網狀網路介面卡的角色與頻道選派之最佳化研究

Abstract

在無線網狀網路中，網路容量是個相當重要的議題。可以透過使用多天線的裝置和多個不重疊的頻道來增加網路容量。因此如何有效的去安排頻道給各介面卡就被廣泛的討論。在混合式無線網狀網路中，每個裝置至少有兩個介面卡。依介面卡功用又可分為可切換式介面卡和固定式介面卡。網路的傳輸主要是由可切換式介面卡和固定式介面卡之間的連線來達成的。在文獻[15]中，作者討論了裝置的介面卡數量大於二時，多出來的介面卡所可能產生的角色問題。對於多出來的介面卡要當做可切換式介面卡或固定式介面卡，作者稱為角色指派問題，且提出了連結層指標-平均衝突連線來評估網路效能。在此論文中，我們專門討論在混合式無線網狀網路上的指派問題。我們會驗證平均衝突連線和網路吞吐量之間的關係且提出兩個演算法來降低網路平均衝突連線以改善網路吞吐量。最後我們會將現有的方法和我們的演算法做一個比較。

The capacity problem is an important issue in wireless mesh networks (WMNs). Itcan be enhanced by using multi-radio devices and non-overlapping channels. Therefore,how to efficiently arrange the non-overlapping channels is widely investigated. In thehybrid WMNs, each device has at least two radios, and the radios are divided into two disjoint sets, switchable radio and fixed radio. Transmissions are mainly through thelink between the switchable radio and fixed radio. In [15], the authors considered an assignment problem for WMNs that the number of radios per node is more than two.This problem is called role assignment problem. They also propose a link-layer metric: average conflicted links (ACL) for the assignment problem. In this thesis, we will validate the correlation between ACL and the throughput of network. We also propose two approximation algorithms to minimize ACL as well as to enhance the network throughput. Finally, we will compare our algorithms with other existing methods.