在無線隨意網路通訊設計與應用中，合作式通訊對減輕網路訊號衰減以及處理信號干擾等問題具有優勢，而媒體存取控制協定的充分利用可以有效的增進網路效能、使無線網路更加可信賴以及減少能源消耗。之前的合作式媒體存取控制協定大多是基於傳輸速度較低的IEEE 802.11b標準所設計的，而IEEE 802.11g或是IEEE 802.11n具備較高傳輸速度，因此得到廣泛關注與應用。因此,我們提出一個基於IEEE 802.11g也可以用在IEEE 802.11n的高效能合作式通訊協定,用以提高網路傳輸效率,降低網絡傳輸延遲時間。我們首先將轉傳節點按照其傳送速度的不同進行分組，將速度接近的轉傳節點分配在同一個群組，這樣在實際傳輸中可以較快的找到轉傳節點幫忙傳輸資料。此外，我們還設計了一種數據重傳機制，當封包傳遞失敗的時候，不需要完成整個傳送週期的數據重新傳送，而改由轉傳節點利用已存有傳輸資料幫忙重送，這樣可以有效的減少重傳時間。本論文的模擬結果顯示我們所提出的合作式隨意網路媒體存取控制協定，與前人的控制協定相比，不僅可以有效提高網路的吞吐量，還可以減少網路的延遲時間。

Cooperative communications with another node is a promising method to mitigate signal fading and interference problem for wireless ad hoc networks. A good cooperative MAC protocol can improve network performance, make the network more reliable and reduce energy consumption. The previous cooperative MAC protocols are designed for IEEE 802.11b. Thus recent users use IEEE 802.11g or 802.11n more frequently. We design a cooperative MAC protocol for IEEE 802.11g and can also be used in 802.11n. In our proposed protocol, the relays with similar transmission rates are partitioned to the same group. It can reduce efficiently the time slots to select the better relays to help data transmission. Furthermore, we propose a retransmission scheme to reduce the retransmission time. When data transmission is fail, the backup relays which have received the data frame will help retransmission instead of repeating the retransmission cycle. Simulation results show that the proposed protocol outperforms previous work in terms of increase the network throughput and reduced the average delay time.

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