LTE-A系統下機對機通訊之節能與QoS確保分組機制

Abstract

M2M是指機器與機器之間的溝通，由於M2M通訊的特性，大量的機器可能會同時存取基地台，以要求資料傳輸，基地台的壅塞造成機器的存取延遲時間的增加，因而造成機器的QoS無法被滿足，而且因為整體機器數量龐大，系統的能量消耗巨大，如何能夠有效率的使用能源，同時確保QoS的滿足十分重要。 我們在本篇論文中，提出了機對機通訊之節能與QoS確保的分組機制(Energy Efficient and QoS Guaranteed Grouping Scheme, EQGS)，透過這個機制，將機器分成不同群組，達到有效率的使用能源，並且確保每個機器的QoS能夠被滿足。EQGS會根據機器本身的緊急程度，讓較緊急者有較高的優先權選擇加入群組，而在選取的同時傳輸能量消耗低的連線會優先考量，在所有機器都順利加入群組時，接著EQGS會將能量使用上沒有效率的協調者關掉以節省協調者的操作電源，並將其群組內的機器重分配到其他協調者的群組或是延遲到下一個時間再重送，藉此以達到有效率的能量使用，並且每個機器都能夠滿足QoS的要求。模擬結果顯示EQGS比傳統機制更節省能量，同時也能夠滿足機器的QoS要求。

M2M communication refers to machines to machines communications. The nature of M2M communication is that massive machine type communication devices (MTCD) may exist in the system. Congestion occurs when MTCDs access the eNB simultaneously, so MTCDs may fail to satisfy QoS requirements due to long access delay. Energy consumption is another issue due to massive MTCDs. Therefore, it is important to achieve energy efficiency while ensuring QoS requirements of MTCDs. We propose an Energy Efficient and QoS Guaranteed Grouping Scheme (EQGS) in this thesis. The scheme aims to achieve energy efficiency and guarantee the satisfactions of QoS requirements of MTCDs by assigning MTCDs into several groups. EQGS prioritize MTCDs according to their urgency and allow MTCDs with higher urgency select coordinators, the group heads, first to make sure the delay requirement meets. In the meanwhile, each MTCD prefer to select the coordinator with the lowest energy consumption. After all MTCDs finishing the grouping, EQGS will disable energy inefficient coordinators to further save operating power of coordinators and either re-distributes MTCDs or postpone MTCDs to next frame time to transmit. Simulation results show that EQGS consume less energy than the conventional scheme while satisfying QoS requirements of MTCDs.