在無線隨意網路下利用功率調整增進網路流量的機制

Abstract

在無線隨意網路上傳輸資料功率調整對增加整個網路流量相當有潛力，在現存的傳輸資料功率調整的方法中，大多數的方法都是使用多條頻寬及多個收發器。但是使用多條頻寬跟多個收發器不僅比較浪費頻道資源也會增加硬體花費的費用。

在這篇論文中我們提出一個創新功率控制的演算法使用單條頻道及單個收發器去增加整個網路的流量。我們將IEEE 802.11 控制層下的演算法做修改，我們並不使用最大的功率傳輸封包，而是依照頻道的品質動態的去調整傳輸封包。此外當節點要傳輸資料時並不用等到頻道沒有人使用才能傳輸，使得我們在同一時間多個節點可以同時進行傳輸。所以頻道利用率及網路流量都因此而上升。此外因為調整功率大小可能會有隱藏節點的問題產生，在我們的演算法中我們也有考慮到隱藏節點的問題。而在模擬的結果顯示出我們的演算法成功的增加網路的流 量。

Transmission power control (TPC) has great potentials to increase throughputs of a mobile ad hoc network (MANET). Among existing TPC protocols, most of them can achieve throughputs by using multiple channels and multiple transceivers. Using multiple channels and transceivers is not only wasting resources but also increasing hardware costs.

In this thesis, we present a novel power controlled MAC protocol which uses a single-channel and a single-transceiver to increase network throughputs by modifying IEEE 802.11 MAC layer protocol. Instead of using a maximum power to transmit RTS and CTS, our protocol uses an adaptive power which based on a channel quality information to transmit data. Since our protocol allows multiple pairs concurrently transmitting data, we can improve spatial reuses and the throughputs in networks. We also consider hidden terminal problems. The performance evaluation is shown that our protocol successfully increases network throughputs. The performance of our protocol is better than the POWMAC protocol and IEEE 802.11 protocol.