IEEE 802.16是針對支援都會型無線網路以及微波頻帶提出的一種新的通訊標準，並且以無線的方式取代最後一哩的寬頻網路接取。因為使用了高效率的無線訊號傳輸，所以傳輸距離最遠到達48km，末端的頻寬有300Kbps～2Mbps，與傳統的有線網路做比較，其硬體鋪設較為快速，且不受地形的影響以及低成本的特性，其主要是應用在單點對多點間的無線寬頻傳輸，並設定在無障礙空間範疇內傳輸。
由於802.16系統支援各種不同的傳輸服務，服務品質要求各不相同，為求系統資源的最有效利用提供最佳服務品質，因此針對IEEE802.16提出頻寬分配及資源管理(Quality of Service)是非常重要的研究方向，而在IEEE 802.16中依據服務特性的不同，提供了五種形式的傳輸品質，包含了非請求的頻寬分配服務(UGS)、延伸即時可變速率服務(ERT-VR)、即時可變速率服務(RT-VR)、非即時可變速率服務(NRT-VR)、盡力傳送服務(BE)。
在常見的相關論文中針對IEEE 802.16的頻寬分配及資源管理提出相關的方法，在BS(Base Station)端必須針對SS端(Subscriber Station)所提出的不同服務需求，先執行允入控制的判斷，此步驟依照頻寬的分配，決定是否接受或拒絕SS端所提出的需求，之後再根據所提出服務需求的等級不同，來決定其優先權等級，最後在依據其優先權等級及所提出的頻寬需求分配其所需要的頻寬。其中大多是針對延遲及頻寬分配之問題做詳細的探討，但是並未針對訊務的傳輸時間作探討。
    因此本篇論文提出一個不同的允入控制法則來有效的進行頻寬需求的判斷，其方法是針對QoS中的非請求的頻寬分配服務部份提出改善，並將重新依據非請求的頻寬分配服務參數及傳輸間隔的大小來效率地分配頻寬。當發生衝突的情況時，將會依照非請求的頻寬分配服務的延遲時間參數來解決這個問題，有較大的可容許時間參數當發生碰撞時其頻寬就可以分配在較晚的時間，而較小的可容許時間參數就必須在較早的時間被分配。最後，我們的實驗將會使用IEEE 802.16的模組在NS2軟體平台上進行模擬，並定義相關的QoS參數，依照上述的方法其結果網路傳輸可以接受更多的服務需求，且對於網路的流量(throughput)有較好的改進。

IEEE 802.16 is a new communication standard for supporting the Wireless Metropolitan Area Network and the microwave and the milliwave frequency band. IEEE 802.16 replaces the last one mile by the way of wireless connects and fetches. Because it used high-efficiency wireless signal transmitting and treatment technology, it is farthest to 48km to transmit the distance, wide 300Kbps- 2Mbps frequently of end. Compared with the tradition wired network, IEEE 802.16 possesses the characteristics of the fast laying of hardware, being free from the effect of topography, and low cost. The orientation of its application is mainly on wireless broadband transmissions of Point-to-Multipoint, and transmissions of Line Of Sight.
   In common relative papers, they proposed the related method to be aimed at bandwidth allocated in IEEE802.16 and Quality of service. In Base Station(BS) part, BS must perform the decision of admission control according to the different service requests from SS. This step is determining whether BS accepts or rejects the requests from SS. Then based on the different classes of asked service requests, BS determines the priority class. Finally, BS allots the bandwidth by the priority class of the requests.
   In this paper, we proposed a different admission control method for improving the UGS part of QoS. This method is improving the part of UGS in QoS and effectively allotting bandwidth according to the parameter of UGS and the size of transmission interval. When the situation of conflict is happened, we will solve the problem by the delay time parameter of UGS. Finally, we will simulate our experiment by using the IEEE 802.16 model on NS2 software platform, and will define related parameter. We can accept and tolerate the requests having longer delay time, and make admission control to accept more service requests.

目錄
致謝	I
淡江大學論文提要	II
英文提要	III
目錄	1
圖目錄	3
表目錄	5
第一章	緒論	1
1.1	前言	1
1.2	研究動機及目的	5
1.3	論文章節架構	7
第二章	相關背景之研究	8
2.1.	IEEE 802.16 的特性	8
2.2.	IEEE 802.16e-2005系統架構	10
2.2.1.	IEEE 802.16 MAC Protocol	13
2.2.2.	Frame 架構	16
2.2.3.	DL-MAP及UL-MAP	18
2.3.	IEEE 802.16e-2005訊務分類	20
2.4.	Service Flow 介紹及其運作方式	23
2.5.	IEEE 802.16e-2005 QoS架構機制	26
2.6.	IEEE 802.16相關允入控制法則	28
2.6.1.	針對SS端的允入控制之研究	28
2.6.2.	High Efficiency Admission Control	31
第三章	系統架構及允入控制之描述	33
3.1.	系統環境概述	33
3.2.	IEEE 802.16e-2005 允入控制之研究	34
3.2.1.	Handoff service:	35
3.2.2.	UGS Service	36
3.2.3.	Extended Real-time Variable Rate service，Real-time Variable Rate service	47
3.2.4.	Non-Real Time Variable Rate Service	49
3.2.5.	Best-Effort	51
第四章	模擬與結果分析	52
4.1.	模擬環境之描述	52
4.2.	模擬參數設定	53
4.3.	允入控制機制下之模擬與結果	54
第五章	結論與未來工作	63
參考文獻	65

 
圖目錄
圖1-1 現今無線網路之比較	5
圖2-1 802.16架構圖	11
圖2-2 Fixed WMAN + Mobile WMAN	13
圖2-3 IEEE802.16 TDM Frame Structure	15
圖2-4 TDD模式下的Frame structure	18
圖2-5 Maximum time relevance of DL-MAP and UL-MAP(TDD)	19
圖2-6 Maximum time relevance of DL-MAP and UL-MAP(FDD)	19
圖2-7 Minimum time relevance of DL-MAP and UL-MAP(TDD)	20
圖2-8 Minimum time relevance of DL-MAP and UL-MAP(FDD)	20
圖2-9 IEEE 802.16 QoS 架構圖	27
圖3-1 允入控制流程圖	35
圖3-2 UGS illustration	38
圖3-3 Bandwidth Conflict	41
圖3-4舉例1	44
圖3-5舉例2	45
圖3-6舉例3	47

圖3-7 NrtVR訊務的限制頻寬	50
圖4-1 在不同的保留頻寬比例及Jitter下的UGS接受個數	55
圖4-2 固定所有訊務的Q值各訊務所能接受要求的個數	55
圖4-3 固定所有訊務的Q值各訊務所能分配到的頻寬	56
圖4-4 Pertvr=3 ，Pertvr=2，Pertvr=1時剩餘頻寬分配	57
圖4-5 Pertvr=5，Prtvr=4，Pnrtvr=1時剩餘頻寬分配	58
圖4-6 原始由頻寬判斷允入控制機制中各訊務的阻絕率	60
圖4-7 各訊務Q=1阻絕率	62
圖4-8 各訊務Q=0阻絕率	62

 
表目錄
表1-1 現今無線區域網路技術之規格	4
表2-1 802.16主要規格之特性	10
表2-2 IEEE 802.16e-2005 QoS 需求參數與應用	23
表3-1 UGS Scheduling Parameter	37
表4-1 系統環境參數設定	53
表4-2各訊務類別的相關參數設定	55

參考文獻
[1]	IEEE. 802.16-2004: Air Interface for Fixed Broadband Wireless Access Systems. Standard, 2004. IEEE standard for local and metropolitan area networks.
[2]	IEEE. 802.16e-2005: Air Interface for Fixed and Mobile Broadband Wireless Access Systems – Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands. Standard, 28 February 2006. IEEE standard for local and metropolitan area networks.
[3]	http://www.juniper.net/
[4]	http://www.wimaxforum.org/home/
[5]	http://www.dslforum.org/
[6]	Dong-Hoon Cho; Jung-Hoon Song; Min-Su Kim; Ki-Jun Han, “Performance Analysis of the IEEE 802.16 Wireless Metropoltitan Area Network”, First International Conference on 2005 DFMA'05 Page(s):130 - 137
[7]	Govindan Nair, Joey Chou, Tomasz Madejski, Krzysztof Perycz, David Putzolu, Jerry Sydi, “IEEE 802.16 Medium Access Control and Service Provisioning”, Intel Technology Journal ,vol. 08, Issue 03, August 20, 2004
[8]	Jianfeng Chen, Wenhua Jiao, Hongxi Wang, “A Service Flow Management Strategy for IEEE 802.16 Broadband Wireless Access Systems in TDD Mode”, IEEE International Conference 2005, 16-20 May 2005 Page(s):3422 - 3426 Vol. 5 
[9]	Nai’an Liu, Xiaohui, Li, Changxing Pei, Bo Yang, “Delay Character of a Novel Architecture for IEEE 802.16 Systems ”, Parallel and Distributed Computing, Applications and Technologies ,Page(s):293 – 296,05-08 Dec. 2005
[10]	Jianfeng Chen, Wenhua Jiao, Hongxi Wang, “A Fair Scheduling for IEEE 802.16 Broadband Wireless Access Systems”, ICC2005, May 16-20, Souel, Korea 
[11]	Jianfeng Chen, Wenhua Jiao and Qian Guo, “Providing Integrated QoS Control for IEEE802.16 Broadband Wireless Access Systems” IEEE 62nd Vehicular Technology Conference, vol. 2, pp. 1254-1258, Sept. 2005.
[12]	Jonny Sun, Yanling Yao and Hongfei Zhu, “Quality of Service Scheduling for 802.16 Broadband Wireless Access Systems”, IEEE 63rd Vehicular Technology Conference, vol. 3, pp. 1221-1225, Sept. 2006.
[13]	H. Wang, W. Li, and D. P. Agrawal, “Dynamic admission control and Qos for 802.16 Wireless MAN”, 2005 Wireless Telecommunications Symposium, April 28-30, 2005, pp.60-66.
[14]	Liping Wang, Fuqiang Liu, Yusheng Ji, Nararat Ruangchaijatupon, “Admission Control for Non-preprovisioned Service Flow in Wireless Metropolitan Area Networks”, ECUMN'07,2007
[15]	Yu-Chang Chen, Tai-An Lai “Enhanced the Transmission Performance for QoS Guarantee in WiMAX ”, Jounal of Internet Technology ,Vol. 8 No. 2, May 2007
[16]	Xin Guo , Wenchao Ma , Zihua Guo , Zifeng Hou, “Dynamic Bandwidth Reservation Admission Control Scheme for the IEEE 802.16e Broadband Wireless Access Systems Dynamic Bandwidth Reservation Admission Control Scheme for the IEEE 802.16e Broadband Wireless Access Systems”, WCNC 2007,page(s): 3418-3423 ,March 2007
[17]	吳中實,王旭東,”改善802.16-2005系統下之排程法則”,國立中央大學通訊工程研究所碩士論文,July 2006
[18]	吳中實,呂秉諺,”在802.16架構下之允入控制之研究”,國立中央大學通訊工程研究所碩士論文,July 2006