無線感測網路近年來廣泛應用於生態環境監控，提供一個密集的時間與空間上的監測，此為傳統監控生態方式所不及的。因為感測節點能量上的限制，如何有效節能的將感測資料傳送到基地台，延長感測網路的網路生存期間是相關研究努力的目標。

　　本研究提出一個新的叢集演算法(DC-ENBACH)，將感測區域分成遠近兩區域，因為較遠的節點消耗能量較大，因此我們分配遠區域擁有一個叢集首，近區域兩個叢集首，並搭配排除範圍，以確能夠達成叢集首在空間上的均勻分布，以減少平均每回合能量消耗，並使用視窗式的叢集首選擇機制，讓剩餘能量較高的節點能夠擁有競爭叢集首的資格，使每一個區域的節點剩餘能量分佈能夠盡量縮小在一定的區間中，再搭配遠近區域劃分狀態的調整，使兩區域的能量分佈區間也能夠大部分重合，使得能量使用率趨近於100%，進而達到延長網路生存時間的目的，又因為動態協調者為每回合遠區域的叢集首擔任，因此可以避免協調者故障而導致系統不穩定的情形。

由實驗結果證實，DC-ENBACH擁有較低的平均每回合能量消耗和較好的能量使用率，因此DC-ENBACH擁有比LEACH多50%的平均網路生存時間。另外，在所有實驗上，DC-ENBACH的能量使用率均大於99%，證明DC-ENBACH擁有穩定的網路生存時間。

In recent years, wireless sensor networks are extensively employed in the environment monitoring. It provides intensive environment monitoring in temporal and spatial respects, while the traditional environment monitoring can’t afford it. Due to the limited energy of sensor nodes, it is of researching goal that the lifetime of sensor networks is prolonged by transmitting the sensed data to the base station in the energy-saving way.
We propose a new clustering algorithm (DC-ENBACH) based on two-stage cluster-heads selection mechanism which partition the sensing area into far and near regions. Because the farer nodes from the base station consume more energy, the far region is allocated only one cluster-head while the near region can have two cluster-heads. With the aid of exclusion area, the elected cluster-heads per round are evenly distributed in the sensing area. By employing the window-based cluster-heads selection mechanism, the nodes with the higher remaining energy can have higher priority to compete for cluster-heads such that the remaining energy of all the nodes per region are converged on a small interval. With the adaptive adjustment of the partition state, the energy distribution intervals of two regions are mostly overlapped, resulting in its energy utility approaching to 100%. Hence, DC-ENBACH can extend the network lifetime significantly. Furthermore, the elected cluster-head in the far region per round is served as the dynamic coordinator. The dynamic coordinator mechanism makes the system robust, while the fixed coordinator mechanism needs the re-election of the coordinator due to its failure.
The simulation results show that DC-ENBACH possesses the lower average energy consumption per round and the better energy utility. Therefore, the average network life time is 50% more than that of LEACH. Furthermore, the energy utilities of DC-ENBACH for all the experiments are greater than 99%. This ensures that DC-ENBACH can have stable network lifetime.

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