傳統的IEEE 802.11 網路是設計給小規模本地無線網路使用的，然而隨著物聯網的出現 (IoT)，無線網路的使用情境也隨之改變，因此最近IEEE TGah 正在制定一個專門給物聯網使用的新傳輸協定名叫IEEE 802.11ah，IEEE 802.11ah 採取一個分群的MAC傳輸協定來降低感測器之間競爭的負擔，但是大多數現有的方法都是隨機把感測器分群，很少著重在如何有效的分群，所以此篇論文我們主張分群後網路的效能和感測器的異質網路需求有很大的關係，進一步的我們提出一個考慮網路競爭機率的流量模型，再來提出一個流量感知的感測器分組來改善網路的使用度，最後經由模擬顯示我們的方法比其他方法可以得到更好的網路使用度特別是在網路接近飽和的時候。

Traditional IEEE 802.11 network is designed for the use of small scale local wireless networks. However, the emergence of the Internet of Things (IoT) has changed the scene of wireless communications. Thus, recently, the IEEE task group ah (TGah) is dedicated to the standardization of a new protocol, called IEEE 802.11ah, which is customized for this type of large-scale networks. IEEE 802.11ah adopts the grouping-based MAC protocol to reduce the contention overhead for each group of devices. However, most existing designs simply randomly distribute devices to groups, and less attention has been paid to the problem of forming efficient groups. Therefore, in this paper, we argue that the performance of grouping is closely related to heterogeneity in traffic demands of devices, and further build a traffic model with consideration of transmission probability. Then a traffic-aware grouping algorithm is proposed to
improve channel utilization of each group. The evaluation shows that our traffic-aware grouping outperforms the other methods, especially when the network is almost saturated.

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