長期演進技術升級版 (Long Term Evolution-Advanced, LTE-A) 是一個設計給人對人 (Human-to-Human, H2H) 通訊的電信網路技術，當大量的機器對機器 (Machine-to-Machine, M2M) 同時一起存取網路時，會導致低落的隨機存取 (Random Access RA)成功率和高程度的壅塞問題，可能會產生浪費無線資源、封包掉落、延遲和額外的能源消耗，最壞的情形可能會使得機器對機器的服務產生錯誤，提出一個在長期演進技術升級版可以有效解決對於機器對機器通訊上壅塞問題的方法是相當緊急的，在此文獻中，我們提出了一個壅塞程度降低的機制，可以分析和模型化在長期演進技術下的隨機存取程序，進而試著找出在隨機存取程序崩塌點，再設計一個名為裝置對裝置 (Device-to-Device, D2D) 合作式轉傳方案去減輕壅塞問題，同時，此研究再提出一個針對改進效能的轉傳存取限制演算法和為了人對人通訊的隨機存取資源分離方案，此提出的方法可以有效地降低網路壅塞問題，模擬結果顯現出使用提出的機制可以使得網路效能和壅塞有明顯的改善。

The Long Term Evolution-Advanced cellular network is designed for human-to-human (H2H) communication. When a large number of machine-to-machine (M2M) devices are trying to access the network simultaneously, it leads to a low random access (RA) successful rate and high congestion problem, which may cause the waste of radio resources, packet loss, latency, extra power consumption, and the worst, M2M service error. There is an urge to propose an efficient method for M2M communication on the LTE-A network to resolve the congestion problem. In this study, we propose a congestion reduction mechanism, which can analyze and model the RA procedure on the LTE-A network, to find out the collapse point in the RA procedure and then design a scheme named D2D cooperative relay scheme to relieve the congestion problem. Meanwhile, this work also adds a relay access barring algorithm to improve performance and a RA resource separation mechanism for H2H communication. The proposed method can effectively reduce the network congestion problem. Simulation results show that the network throughput and the congestion can be significantly improved using the proposed mechanism.

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