IEEE 802.11ax無線區域網路中最小化延遲時間的資源分配研究

Resource Allocation for Minimizing Delay in IEEE 802.11ax WLANs

陳佩妘(Pei-Yun Chen)

指導教授 ： 石貴平

淡江大學/工學院/資訊工程學系資訊網路與多媒體碩士班/碩士(2021年)

https://doi.org/10.6846/TKU.2021.00763

摘要

本論文針對無線區域網路(Wireless Local Area Networks, WLANs)中，現有的(Orthogonal Frequency Division Multiple Access, OFDMA)上傳機制所造成的傳輸延遲問題，提出有效的解決策略。現今隨著無線網路迅速發展，人們對於WLANs的需求越來越高，為了滿足使用者的需求，IEEE 802.11ax標準加入了OFDMA的機制，讓多個節點可以同時傳輸資料。而在IEEE 802.11ax上傳機制中，有兩種傳輸方式: 1)透過競爭的方式傳輸，2)透過AP調度的方式傳輸。這兩種傳輸方式皆可能出現後面要傳送資料的節點因傳輸延遲時間太長而造成封包丟棄的問題。因此本論文提出一種新的分配機制，用於解決節點傳輸延遲問題。此機制將選擇資料量較少的節點先分配傳輸。另外本論文亦提出一判斷方式以切割資料，來降低傳輸延遲時間。根據模擬結果顯示此機制可以有效降低傳輸延遲時間，並有效的提高網路的效能。

關鍵字

IEEE 802.11ax ； OFDMA ； 資源分配 ； 傳輸延遲 ； WLANs

並列摘要

The paper proposes effective solutions to the transmission delay problem caused by the OFDMA (Orthogonal Frequency Division Multiple Access) uplink transmission delay in wireless local area networks (WLANs). Nowadays, with the rapid development of wireless networks, the demand for WLANs is getting higher and higher. To meet the needs of high traffic load, the IEEE 802.11ax standard adopts the OFDMA mechanism to allow multiple users to transmit at the same time. In IEEE 802.11ax uplink transmissions, there are two transmission methods: 1) Random Access (RA) and 2) Scheduled Access (SA). Both two transmission methods suffer the long transmission delay problem. Therefore, the paper proposes a new resource allocation mechanism to solve the long transmission delay problem. The proposed mechanism can select the node with a small amount of data to allocate resources first. Moreover, the proposed mechanism also designs a criterion to cut the data to reduce the transmission delay time. According to the simulation results, the proposed mechanism can effectively reduce the transmission delay time and improve the performance of the network.

並列關鍵字

IEEE 802.11ax ； OFDMA ； resource allocation ； transmission delay ； WLANs

參考文獻

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