計劃中文名稱: 在B5G行動通訊網路上適用於URLLC的智慧換手方法

中文計畫摘要：
在5G Open-RAN (Radio Access Networks)行動通訊網路中，傳統的換手機制只會根據UE (User Equipment)回報的RSRP (Reference Signal Receiving Power)作為換手的依據，但是當gNB (5G Node Basestation)處於負載較高的狀態時，此傳統換手機制無法滿足uRLLC (Ultra-Reliable and Low-Latency Communications)的應用，例如無人機與自動駕駛的汽車在傳送控制訊息時，需要換手到較適合的基地台來滿足它們的高可靠度(Ultra-Reliable)與低延遲(Low-Latency)的要求，為了解決這個問題，本計畫在B5G行動通訊網路中提出了一個全新的適用於uRLLC的智慧換手機制，UE會週期性的將BLER (Block Error Rates)與RTT (Round-Trip Time)回報給gNB，gNB會根據UE回報的BLER與RTT計算出gNB的品質指標(gNB Quality Index, GQI)，當UE判斷所連接的gNB無法滿足uRLLC應用的需求時，UE會計算出UE的品質指標(UE Quality Index, UQI)並傳送給5GC (5G Core)，5GC根據UE回報的UQI與gNB回報的GQI並透過uRLLC換手演算法找出最適合的gNB，我們將使用NS-3來模擬此革新式的uRLLC換手機制，從模擬結果，我們證明使用我們的uRLLC換手機制比使用傳統的換手機制更能有效的降低B5G行動通訊網路中的BLER、RTT與封包遺失率。

關鍵字 ：B5G、高可靠度、低延遲、換手機制、uRLLC。

英文計畫摘要：
In 5G Open-RAN (Radio-Access Networks) mobile communications, the traditional handover mechanism simply uses RSRP (Reference Signal Receiving Power) reported by UE (User Equipment) as a trigger. However, this mechanism cannot satisfy the uRLLC (Ultra-Reliable and Low-Latency Communications) applications, such as the control messages in drones and auto-pilot vehicles may require to be served by an adequate serving gNB (5G Node Basetation), particularly in heavy traffic load. In order to solve this problem, in this project, we propose an intelligent handover mechanism for the uRLLC applications in B5G. In this mechanism, UE will periodically report BLER (Block Error Rates) and RTT (Round-Trip Time) to a gNB, and the gNB will calculate the GQI (gNB Quality Index) based on the value reported by the UE. When the UE found that the serving gNB can no longer satisfy the requirements of the uRLLC applications, UE will calculate the UQI (UE Quality Index) and send it to 5GC (5G Core). When 5GC receive UQI, it will execute the uRLLC handover algorithm. Consequently, the best target gNB for the UE to handover will be determined. We will use NS-3 to simulate the proposed intelligent handover mechanism. Simulation results will demonstrate that the proposed handover mechanism is more effective to reduce BLER, RTT, and packet loss rate, when it is compared to the traditional handover mechanism.

關鍵字 ：B5G, High Reliability, Low Latency, Handover, uRLLC.