現今，新興的高密度異質型網路能有效解決在無線通訊環境中隨時隨地存取的問題，然而，在高密度異質型網路中換手過程是個不可避免的問題，有效率的換手演算法不僅可以實現負載平衡的目標，也提升了整個系統的吞吐量。
在本論文中，我們提出了一個在異質型網路中高效能負載智能垂直換手演算法，藉由附近網路發出其系統負載的輔助，在垂直換手過程中，計算複雜度可以明顯地降低；此外，有效的處理擁有相對輕流量的網路，能使掉線率顯著的降低，更重要的是，使用者及整體系統的吞吐量能被大幅的提升。

Nowadays, the emerging hyper-dense heterogeneous network (HetNet) is an effective solution to building an easy-access wireless communication environment. In the hyper-dense HetNet, however, the inescapable handoff procedure is the key to its success. An effective handoff algorithm can not only achieve the goal of load-balancing but also enhance the overall system capacity. In this thesis, we proposed an efficient load-aware vertical handoff (VHO) algorithm for HetNets. With the aid of the system load information from the neighboring cells, the computational complexity during the VHO procedure can be significantly reduced. Moreover, by effectively multi-stage off-loading the cells with relatively light traffic loads, the dropping rate can be significantly reduced. Most importantly, the user and the overall system capacity can be greatly enhanced as well.

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