現今行動裝置使用者日益增加，無線網路(Wireless Local Area Network, WLAN)存取點(Access Point, AP)與無線工作站(station, STA)分佈更為密集，當AP佈置密度過高時，訊號干擾的重疊範圍增加，導致使用者可能頻繁接收到來自不同AP或其他STA傳送的RTS/CTS控制訊框而設定網路配置向量(Network Allocation Vector, NAV)的情形, 導致實際可以上傳或下傳的時間變小。為了提高效能, 在802.11ax草案中，除了多使用者多輸入多輸出的支援外，也加入了由AP啟動的多使用者上傳的觸發功能, 然而最近很多研究證明全雙工(Full Duplex, FD)傳輸將可以更進一步提升單一傳輸頻道的容量，由於802.11ax草案並沒有涵蓋全雙工相關的媒體存取控制協定，若在支援全雙工的AP上,隨機選擇存取點在觸發訊框的清單上，除了因為NAV的問題, 也會因上述提到的密集WLAN問題的嚴重干擾,以及FD的使用者相互間的干擾(Inter-client Interference , ICI)而大大降低網路傳輸的品質。在本篇論文中，我們提出新的多使用者全雙工媒體存取控制協定，除了改善隱藏節點問題，我們利用著色演算法將工作站分群，並以每群為主體，藉由計算信號和干擾雜訊比找出最大頻道容量的方式，獲得每一次全雙工傳輸的最佳組合。比起隨機選擇方式，我們提出的方法在效能上有明顯的增加。

As the increase in users of mobile device, the distribution of the access points (AP) and stations (STA) for wireless local area network (WLAN) is getting intensive as well. However, when the deployment density of APs is too high, the overlapping area of signal interference will be extended, resulting in the fact that users set network allocation vector (NAV) afte0r frequently receiving RTS/CTS from different APs or other STAs. Consequently, the actual time for uplink and downlink decreases.
To raise the efficiency, in 802.11ax draft, besides supports of multiuser multiple input multiple output (MU-MIMO), the trigger operation by AP of uplink for multi-user is added. Lots of recent researches, nevertheless, prove that full-duplex (FD) transmission is able to further increase the capacity of single channel. Because 802.11ax draft doesn’t include the medium access control (MAC) protocol related to FD, among APs supporting of FD, random selection of APs in the frame list significantly lowers the quality of transmission, with problems of NAV, serious interference of intensive WLAN deployment, and inter-client interference (ICI) of FD users.
In this thesis, a new multi-user FD MAC protocol is addressed. In addition to improvement of hidden terminal problem, vertex coloring algorithm is applied to group the STAs. With every group in unit, we can find the way to maximum channel capacity by calculating the SINR, and get the best arrangement for every FD transmission. Compared to random selection, the method we proposed has obvious advantage of efficiency.

IEEE 802.11 Task Group AX. Status of Project IEEE 802.11ax High Efficiency WLAN (HEW)
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