IEEE 802.11規格在網路的實體層上雖然定義了多個可用頻道，但在其分散協調功能(IEEE 802.11 Distributed Coordinate Function)的媒體存取控制層中，卻只設計了一個單一的共享頻道給網路節點使用。如果我們在媒體存取控制層也採用了多重頻道的話，則可在同一時間內讓數對網路節點同時傳送資料，藉以提高網路效能。在本文中，我們提出一個以群組為基礎的多重頻道媒體存取控制協定，藉由將網路節點分群的方式以達到多頻道傳輸的目的。將網路節點分群的另一個優點在於不只資料封包可以用多重頻道傳輸，控制封包一樣可以同時在數個頻道上傳送。我們的協定簡單、容易實做，適合廣大的無線隨意網路。藉由模擬結果，我們提出的協定跟之前的文獻相比亦有較佳的網路效能。 The IEEE 802.11 standard defines multiple channels available at the physical layer, but the MAC protocol of IEEE 802.11 Distributed Coordinate Function (DCF) is only designed for sharing a single channel between nodes. When we exploit multiple channels in MAC protocol, we can achieve a higher network throughput than using one single channel due to that multiple transmissions can take place simultaneously. In this thesis, we proposed a novel group-based multi-channel MAC protocol based on grouping nodes which can not only support utilizing multiple channels to transmit data packets but also allow using multiple channels to propagate control packets. Our protocol operates with two transceivers per node and requires time synchronization among all the hosts in order to divide time into a lot of beacon intervals. The protocol we presented is simple and suitable for wireless ad hoc networks with multiple available channels. The simulation results show that our protocol has the superior performances in network throughput to previous work.
