WiMAX 網路動態資源配置與換手策略之研究

The Study of Dynamic Resource Allocation and Handover Strategies in WiMAX Networks

梁嘉權(Chia-Chuan Liang)

指導教授 ： 吳中實

國立中央大學/資訊電機學院/電機工程學系/博士(2012年)

摘要

無線寬頻接取網路中，指明 IEEE 802.16 標準為最主要的技術，已逐步成為最佳解決的方式。雖然這標準已經定義四種不同的服務型態，但仍然遺留支援服務品質的資源配置與限制流量進入網路的允入控制來作為開放性的議題。然而直到現在，這個不時被提及與探究的議題顯示還是有許多增進的餘地。因此，本研究的目的是在 IEEE 802.16 劃時雙工無線寬頻接取網路之下，根據對稱與/或非對稱上下行之流量輸入，來探究動態配置的法則，特別是藉由模擬與其他機制做比較；且於有限與無限緩衝區的情況下，針對 throughput 、公平性、與封包丟棄率這三項來做為評估的依據。主要結果顯示，與其他機制相較之下，所提出的法則不僅能提供較好的公平性且能保有令人滿意的服務品質與較高 throughput，而且在有限深度緩衝區的情況，能減緩緩衝區的耗盡；亦即，利用所提出的法則能減少硬體的成本。此外，本文也一併考量在 IEEE 802.16e 網路使用優化 MIH 服務多重跨層換手的機制。換手情境的完整分析顯示，與其他機制相較之下，所提出的機制，不僅能降低分裂時間，而且沒有封包遺失。這兩種已提出的解決方法也許可分別幫助 IEEE 802.16 標準補足所遺漏的部分與在 IEEE 802.16e 網路中達成無縫隙換手。

關鍵字

IEEE 802.21 ； IEEE 802.16e ； 頻寬配置法則 ； WiMAX ； 媒體獨立換手 ； 跨層設計 ； 移動性管理 ； IEEE 802.16

並列摘要

The leading technologies specified in IEEE 802.16 standards have been evolved the most promising solutions in broadband wireless access networks. Having defined four types of service, the IEEE 802.16 standard still left the implementation of resource allocation supporting the four various qualities of service classes and admission control confining the number of flows entering the network as an open issue. Up to this point, however, this issue which has been touched and explored from time to time demonstrates that there is still room for much promotion. Thus, this study aims to explore dynamic bandwidth allocation algorithms in IEEE 802.16 time division duplex broadband wireless access networks under symmetric and/or asymmetric uplink and downlink traffic input, particularly in terms of accumulated throughput, fairness, and packet drop ratio in both infinite and finite buffer cases compared with others by simulations. The major results reveal that the proposed algorithm not only can provide much better fairness and maintain satisfactory quality of service support and high cumulative bandwidth but also in the case of the finite buffer depth is less buffer-consuming than the others, meaning that the hardware cost can be reduced by employing the proposed algorithm. In addition, a multiple cross-layer handover scheme using optimized MIH services in IEEE 802.16e networks is also involved. The thorough analyses of handover scenario show that the proposed scheme not only can reduce handover disruption time but also has no packet loss than the others. The two proposed solutions may help to compensate IEEE 802.16 standards for missing parts and to achieve seamless handovers in IEEE 802.16e networks, respectively.

並列關鍵字

mobility management ； cross-layer design ； MIH ； WiMAX ； Bandwidth allocation algorithms ； IEEE 802.21 ； IEEE 802.16e ； IEEE 802.16

參考文獻

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