近年來無線寬頻網路技術成長相當快速，隨著3GPP Long Term Evolution (LTE)、LTE-Advanced 規格制定成熟，可提供更大的頻寬需求和品質，因此提升機器對機器(M2M)應用廣泛擴張和市場。M2M通訊技術在LTE-Advanced的環境中仍有許多問題挑戰，其中無線資源分配(Radio Resource Allocation)是一個重要議題。 於本篇的論文中我們著重於M2M通訊在LTE和LTE-Advanced 系統的上行鏈路中如何進行無線資源分配，針對M2M在LTE和LTE-Advanced環境中的大量設備特性提出了一個新的動態分組方法，利用動態分組方式提升基地台(eNodeB,eNB)管理和資源分配便利性，並且針對目前提Buffer Status Report (BSR)條件做新的調整來降低因大量設備提出BSR需求會導致信令開銷等衍生問題。由於不同群組內設備的modulation and coding scheme (MCS)狀況不同，因此提出一套針對每個群組的權重計算方式，藉此找出最高優先權群組優先分配RB，且會選擇對群組內設備比較好的MCS來做資源分配。 最後我們將會透過模擬的方式來驗證所提出來的動態分組方法能夠有效提高系統吞吐量和降低信令開銷，且發現動態分組方式能降低因延遲而丟棄封包機率，因此可知動態分組方式能使基地台便利管理M2M通訊中設備並且有效分配無線資源。 ;In recent years, the growth of wireless broadband network technology is quite fast. The specifications of 3GPP Long Term Evolution (LTE) and LTE-Advanced have been developed and their techniques are becoming mature to provide higher bandwidth. This progress will enhance the machine-to-machine (M2M) applications and markets a wide range of expansion. M2M communication technology in the LTE-Advanced environment has many challenges, where the Radio Resource Allocation is the critical one among them.
In this thesis we focus on the radio resource allocation for uplink in LTE networks when dealing with machine-to-machine communications.We propose a new dynamic grouping method to solve the resource allocation and signaling issues of large number of M2M devices in LTE networks. In the proposed scheme, we dynamically adjust the condition in UE to issue BSR so that the signaling overhead can be reduced. AS the devices in each group have different modulation and coding scheme situation, we propose a weight calculation method of each group to find the highest priority group has first priority be allocated the RB with best MCS level.
Finally, we validate our method through exhaustive simulations. The simulation results show that the proposed dynamic grouping method can effectively improve system throughput and reduce signaling overhead. It also illustrates that the proposed method can reduce the packet dropping probability due to the consideration of packet delay in the proposed scheme. Thus the proposed dynamic grouping scheme together with the associated resource allocation enables the base station to manage M2M communications in LTE networks.
