在專用控制通道技術架構下使用時間基準之多重通道無線網狀網路傳輸媒介存取控制協定

Abstract

在使用多重通道的無線網狀網路中，以專用控制通道技術為基礎的網路架構可解決目前大部份多重通道上的問題，如多重通道隱藏主機、失聰與廣播支援等問題。然而在專用控制通道架構下有兩個挑戰：一個是控制通道瓶頸問題，另一個則是通道動態選擇問題。本篇論文即是在專用控制通道技術的架構下，提出以時間為基準的多重通道媒介控制存取層協定，簡稱TBM。此協定包含三大部分，第一部份透過正確預測控制程序的發起時間，以降低多餘的控制成本；第二部份依各節點狀態動態決定每次傳輸的資料封包數量；第三部份則在所有可用通道中，選出對週遭其他節點影響最小的通道來傳輸資料，以提升通道的同時使用率。前兩者能有效的解決控制通道瓶頸問題，第三部份則能提高資料通道的利用率。模擬結果顯示出本論文所提出的TBM較其他方法能提高相當可觀的效能。

In wireless mesh networks (WMNs), the dedicated control channel (DCC) approach can support broadcasting and avoid multi-channel hidden terminal problem and deafness problem in the multi-channel environment. However, there are two serious problems in the DCC approach: the control channel bottleneck and dynamic channel selection problem. In this thesis, a protocol, named the time-based Multi-channel MAC (TBM), is proposed to resolve these two challenges. The TBM protocol consists of three components. The first one aims at reducing the control overhead by properly predicting the control initiation time. The second one can dynamically aggregate multiple packets to transmit with a single control process. The final component selects the channel that has the least influence to nearby nodes to improve channel reusability. Simulation results show that TBM can achieve significant improvement in the throughput in comparison with the existing work.