在無線感知網路下以排程為基礎之資源分配研究

由於現今的無線頻譜資源是採用固定的方式規劃頻譜使用區段，造成頻譜資源使用效率不佳，而行動通訊服務的需求日益增加，在有限頻譜資源下滿足連線服務品質保證亦為重要考量議題。為了增進頻譜的使用效率，因此利用無線感知網路技術（Wireless Cognitive Network）以妥善分配閒置的頻譜資源。主要頻譜（Primary Band）和次要頻譜（Secondary Band）使用的差異化是無線感知系統特有的法則，本論文利用無線頻譜上的感知（Spectrum Sensing）方式，當主要頻譜被占用的情況下，尋找可使用的次級頻譜，妥善配置空閒頻譜資源並設計有效之排程機制及資源分配方法。在強調連線公平性的優先權調整之下，動態調整優先權，以避免低優先權的連線出現延遲（Latency）或者飢餓（Starvation）的情況，並在五種資源分配的情況下作整體效能分析及探討。模擬實驗證明本論文中所提出的Adaptive Scheduling Scheme of Cognitive Network（ASCN）排程機制及資源分配方法與Maximum Rate（Max-Rate）以及Round Robin（RR）演算法比較，在五種資源分配情況下，皆可改善延遲及避免飢餓情況。

關鍵字

無線感知網路；公平性；排程；資源分配

並列摘要

Nowadays, the resource of wireless spectrum is limited because of using fixed bandwidth allocation, and inefficient use of spectrum is become a serious problem. At the moment, in order to increase the efficient use of spectrum, the Wireless Cognitive Network is presented to address this issue. Spectrum sensing collects remaining available resources which allow other users to be able to access, and use of designed scheduler to improve spectrum utilize efficiency. The designed scheduler makes different services correspond to different data streams to provide different Quality of Service with various applications. Priority adjustments and resource allocation were taken into account when the scheduler was designed in this paper. Limiting users with lower priority settings in the scheduling algorithm is efficacious for regulating the order of resource allocations made to the users. The goal is to achieve the highest system performance by enhancing transmission efficacy and satisfying the fairness of resource allocation at the same time. Finally, the scheduling avoids connection latency and starvation related to lower priority resource allocation.

並列關鍵字

Wireless Cognitive Network ； fairness ； scheduling ； resource allocation

參考文獻

[2]Y. Chang, et al., “Cognitive Radio Networking and Communications: An Overview”, IEEE Transactions on Vehicular Technology, VOL. 60, NO. 7, Sept. 2001.

[3]H. Fattah, and C. Leung, “An overview of scheduling algorithms in wireless multimedia networks,” IEEE Wireless Communications, vol. 9, no.5, pp. 76–83, Oct. 2002.

[4]Y. CAC & Victor O. K. Li, “Scheduling Algorithms in Broad-Band Wireless Networks,” IEEE Proceedings of The IEEE, VOL. 89, NO. 1, pp. 76-87, Jan. 2001.

[5]J. Mitola, et al., “Cognitive radio: Making software radios more personal,” IEEE Pers. Commun., vol. 6, no. 4, pp. 13–18, Aug. 1999.

[6]J. Mitola, “Cognitive radio for flexible mobile multimedia communications”, Journal Mobile Networks and Applications, pp. 435-441, 2001.

國際替代計量

在無線感知網路下以排程為基礎之資源分配研究

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