超可靠度和低延遲通訊（Ultra-reliable and low latency communications, URLLC）為第五代行動通訊技術（Fifth generation of mobile technologies, 5G）中的三大應用場景之一，對於傳送封包的延遲要求在1 ms內，且須達到1-10^-5的可靠度。而第三代合作夥伴計劃（The 3rd Generation Partnership Project, 3GPP）於最新5G的標準中，提出了5G更寬廣的使用頻寬，以及頻寬子集（Bandwidth Part, BWP）的新概念，使得裝置能以較省電的方式與基地台通訊。有鑑於在5G多樣化的應用中，可能有URLLC需求及須使用頻寬子集的聯網裝置，本論文綜合以上情境，在有URLLC需求的使用者設備（User Equipment, UE）使用BWP的前提下，使用本論文設計的自適應BWP配置方法，排程下行鏈路（downlink）的URLLC封包，提升傳送效能。 本論文提出之自適應BWP配置方法，包含考慮BWP閒置資源量的IPO（Idle PRB Only）方法，以及考慮BWP資源釋放可能性的RRI（Resource Release Index）方法，兩方法透過各自的機制，以最小的排隊延遲為目標，在基地台排程downlink封包時，讓目標UE切換至合適的BWP以進行傳送。 本論文亦模擬比較兩自適應BWP配置法與固定BWP配置法的效能，並根據模擬的結果，印證了IPO與RRI兩者能確實的緩解流量造成的排隊現象，提升使用BWP時的URLLC效能。 ;Ultra-reliable and low latency communications (URLLC) is one of the three major usage scenarios in 5G wireless communication system. It has a stringent requirement of 1 ms user plane latency with 1-10-5 reliability for one transmission of a packet. The 3rd Generation Partnership Project (3GPP) has release new specifications which mention about the wider bandwidth supported for BS channel bandwidth in 5G, and a new concept called Bandwidth Part (BWP). In case there might be energy critical network device requiring URLLC service, a scenario is adopted in this thesis, including the User Equipment (UE) configured with BWP, and the base station (BS) scheduling downlink URLLC packet to the UE using adaptive BWP allocation method proposed in this thesis. Two BWP allocation method are proposed in this thesis, the first one called IPO (Idle PRB Only) considers the remaining resource of each BWP as a factor for selecting BWP; the second method called RRI (Resource Release Index) considers the resource release probability of each BWP for selecting BWP. Both IPO and RRI target on minimizing the queuing delay in BS which is achieved by switching the target UE to appropriate BWP when BS schedule the downlink URLLC packet. A simulation is performed to compare the two method with Fixed BWP configuration (FIX). According to the results of the simulation, IPO and RRI significantly reduce the queuing phenomenon and increase the performance of URLLC while using the BWP concept.
