在WiMAX媒體存取控制層根據漏桶機制允入控制與動態頻寬分配演算法之設計

Design of Leaky Bucket Based Admission Control and Dynamic Bandwidth Allocation Algorithm for WiMAX MAC

林芳廷(Fang-Ting Lin)

指導教授 ： 郭耀文

國立暨南國際大學/科技學院/通訊工程研究所/碩士(2007年)

https://doi.org/10.6837/NCNU.2007.00238

摘要

在IEEE 802.16d可為無線都會型網路支援高頻寬傳輸，但系統標準並未對頻寬管理提出有效的方法，因此，一個適合可行的頻寬分配演算法，將是非常重要的。
本篇論文提出一套新的頻寬分配機制，與Leaky Bucket演算法搭配，並且操作在WiMAX系統。在PMP(Point-to-Multipoint)模式環境中，對於下載與上傳的訊框(frame)分配，以基地台(Base Station)與用戶端(Subscriber Station)內部的佇列長度為依據，來給予symbols數量，不過只以佇列長度為依據是不恰當的，需加上Leaky Bucket的演算，限制住SS頻寬要求，達到下載與上傳合理的分配。
另外，動態分配頻寬，經由模擬可以得知，讓系統在支援下載與上傳傳送時，當某一方需要較多頻寬時，即時的調整比例，對於頻寬的使用上，比起固定式分配，還來的有效益。

關鍵字

WiMAX ； 頻寬分配 ； 媒體存取控制層 ； 服務品質 ； Leaky Bucket

並列摘要

The IEEE 802.16d claims to support high bandwidth for the wireless metropolitan area network. However, the standard does not propose including the method for bandwidth management. Therefore, a feasible bandwidth allocation algorithm will be very important.
The thesis proposes a Leaky Bucket based admission control algorithm and dynamic bandwidth algorithm for a WiMAX BS. For a new services flow, the admission control algorithm (CAC) will calculate the required bandwidth according to the Leaky Bucket parameters of the flow. Only if the total required bandwidth of all flows is smaller than the system capacity, the new flow can admitted. In the run time, the BS needs to allocate symbols to DL/UL subframes for every frame. In addition to the queue length, we also use the required bandwidth calculated by CAC as a parameter to allocate the bandwidth dynamically.
The proposed algorithm are implemented in the NS-2 simulator and verified by simulation. Compared to the fixed allocation scheme, our algorithm can provide quality of service and uses the bandwidth efficiency.

並列關鍵字

WiMAX ； bandwidth allocation ； MAC ； QoS ； Leaky bucket

參考文獻

[1] IEEE Std 802.16-2004, “IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems”, October 2004.

[2] Hamed S. Alavi, Mona Mojdeh and Nasser Yazdani, “A Quality of Service Architecture for IEEE 802.16 Standards”, Asia-Pacific Conference on Communications, Perth, Western Australia, 3 - 5 October 2005.

[3] Howon Lee, Taesoo Kwon and Dong-Ho Cho, “An enhanced uplink scheduling algorithm based on voice activity for VoIP services in IEEE 802.16d/e system”, IEEE Communications Letters, vol. 9, no. 8, August 2005.

[4] Jian-feng Chen, Wen-hua Jiao and Qian Guo, “An integrated QoS control architecture for IEEE 802.16 broadband wireless access systems”, IEEE GLOBECOM 2005 proceedings.

[5] Yuhi Higuchi, Augusto Foronda, Chikara Ohta, Masahiko Yoshimoto and Yoji Okada, “Delay Guarantee and Service Interval Optimization for HCCA in IEEE 802.11e WLANs”, IEEE WCNC 2007 proceedings.