這篇研究在4G行動系統裡不同速度方案中提議了一個基於QoS(Quality of Service)的雙播傳輸換手機制來有效地改善後端網路資源的利用度。傳統的雙播傳輸機制可以讓所有潛在的目標基地台(Base Station)掌握住用戶資料，因此可以藉由換手時降低封包波動延遲來達到無縫式的連線。然而這個機制在後端網路中導致資源的耗損。當這個機制廣泛地被運用在即時服務時，這些服務的需求增加，由於雙播傳輸的關係，將會導致後端資源極端地耗損。因此，我們提出一個基於QoS的雙播傳輸換手機制來降低雙播傳輸時間來改善後端網路資源的利用度。模擬結果顯示可以改善後端網路資源的耗損。

This study proposed a QoS-Aware handover bicasting scheme under different speed scenario for 4G mobile systems to efficiently utilize backhaul network resources. The conventional bicasting scheme makes all potential target base stations hold the user data, thus it can achieve seamless connectivity by minimizing the packet fluctuation delay caused by handover. This scheme, however, leads to an aggressive consumption of resources at the backhaul network. When this scheme is widely adopted for real-time services and the demand for these services increase, the amount of backhaul network resources consumed due to bicasting will also increase tremendously. Therefore, we proposed a QoS-Aware handover bicasting scheme under different speed scenario which reduces the bicasting time and thus, improves the backhaul network resource utilization. The simulation results prove the efficiency of our scheme in overcoming the aggressive resource consumption at the backhaul network.

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