水下聲波網路中，設計一以電量控制之碰撞避免媒介存取控制協定

A Power Control MAC Protocol for Collision Avoidance in Underwater Acoustic Networks

方彥翔(Yan-Siang Fang)

指導教授 ： 石貴平

淡江大學/工學院/資訊工程學系資訊網路與通訊碩士班/碩士(2012年)

https://doi.org/10.6846/TKU.2012.00716

摘要

透過無線電波傳輸資料所發展的無線傳輸技術已經行之有年。其中以IEEE 802.11所制定的DCF機制最具盛名。然而在傳輸時所帶來的干擾問題以及水下環境中的巨大傳播延遲(Propagation Delay)特性，將使得針對無線電波傳輸所設計的媒介存取控制(MAC)協定，在水下聲波網路中已不適用。本篇論文主要探討在水下使用DCF機制所帶來的干擾問題，以及巨大傳播延遲帶來的隱藏節點問題。透過分析水下聲波傳輸的訊號衰減，提出一套新的運作機制，在考量訊號干擾下，藉以調整封包傳輸所使用的訊號強度，來減少網路上封包的碰撞，進而提升整體網路效能。最後透過實驗模擬，發現本篇論文所提出的運作機制，在網路傳輸效能以及資料傳輸碰撞的表現上有顯著的改善。

關鍵字

隱藏節點問題 ； 電量控制 ； 聲波衰減 ； 訊號雜訊比 ； 傳播延遲

並列摘要

Wireless technology has been developed and used for many years. Due to the nature of water, instead of radio wave, sound wave is used for underwater transmission. However, it will waste a lot of time for propagation at every transmission. Recently, IEEE 802.11 DCF is the most famous MAC protocol but is not suitable for underwater scenarios. We figure out the attenuation of acoustic in underwater and interference problem through our analysis. Therefore, this proposal mainly focuses on how to modify the MAC protocol for underwater acoustic network. It can avoid collisions by power control when sending control packets in our proposed protocol. In simulation, our protocol can outperform than other protocols in network throughput and number of collisions.

並列關鍵字

Hidden terminal problem ； Power control ； Attenuation ； SNR ； Propagation delay

參考文獻

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