在802.16中，通常資料流分為兩種，一種是即時性資料流，另一種為非即時性資料流。在大部分現存的封包排程系統都會給即時性資料流高優先權，非即時性資料流低優先權無條件的方式。如果長時間傳送即時性資料，會造成非即時性資料嚴重延遲，為了改善這個問題，我們提出一個解決方法。

在本篇論文，這個SS會提供目前佇列的長度多少，而802.16基地台將週期性去估測這個長度在下個訊框。假設這個佇列是充滿的，即時性的資料流所分配到的頻寬將減少，而所剩餘的頻寬將分配給非即時性的資料流。假設這個佇列幾乎要空的時候，將會分配到更多的頻寬去傳送即時性的資料流，這樣的方式是完整的透過分配較多或較少的高優先權的封包給即時性的資料流。

In 802.16 system，traffic have two type，one is real time traffic another is non-real time traffic。In most existing packet schedulers giver higher priority to the real time traffic over non-real time traffic unconditionally。If we send real time traffic for long time, and it will caused non-real time traffic serious delay . In order to solve the traffic delay and we proposed a new solved method.

In this paper, the SS reports the length of queue in its buffer. The 802.16BS will estimate its length in the period of next frame. If it is almost full, its assigned bandwidth is decreased and the excess bandwidth will be assigned to non-real time traffic. If it is almost empty, more bandwidth will be assigned. This will be completed by assign more or less high priority packets to the real time traffic.

[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]John.Wiley,Sons .“WiMAX-Technology.for.Broadband.Wireless.Access.2007”( spec 翻述版).

[4]Wha Sook Jeon, Dong Geun Jeong, “Combined Connection Admission Control and Packet Transmission Scheduling for Mobile Internet Services” In IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 55, NO. 5, SEPTEMBER 2006

[5]H. Shimonishhi, M. Yoshida, F. Ruixue and H.Suzuki, “An Improvement of Weighted Round Robin Cell Scheduling in ATM Networks,” In Proc. of the IEEE Global Telecommunications Conference (GLOBECOM’97), Vol. 2, pp. 1119-1123, Phoenix,Arizon,USA.

[6]A.Demers and S.keshav, “Analysis and Simulation of a Fair Queueing Algorithm,” In Proc. Of the ACM Special Interest Group on Data Communication(SIGCOMM’89),1989,pp. 3-12,Austin, Texas, USA.

[7]T. –G Kwon. S. –H. Lee and J. –K. Rho, “Scheduling Algorithm for Real-time Burst Traffic Using Dynamic Weighted Round Robin,”In proc. of the IEEE International Symposium on Circuits and System(ISCS’98), Vol. 6,1998, pp.506-509.Monterey,CA,USA.

[8]S.-J. Yoo and K. –S. Shin, “A Fair Algorithm for Wireless Internet Differentiated Service Networks, “IEICE Transaction on Communication, Vol. E88-B,No.9,Feb.23,2005,pp. 3682-3692.

[9]M. Shreedhar and G. Varghese, “Efficient Fair Queuing Using Deficit Round-Robin,” IEEE/ACM Transactions on Networking, Vol. 4,No 3, June 1996, pp.375-385.

[10]K. Wongthavarawat and A. Ganz, “IEEE 802.16 Based Mile Broadband Wireless Military Networks with Quality of Service Support, “In proc. of the IEEE Military Communication Conference(Milcom’03),Vol. 2, Oct. 13-16,2003, pp.779 784,Boston, MA,USA.

[11]D. Kivanc, G. Li, and H. Liu, “Computationally efficient bandwidth allocation and power control for OFDMA,” IEEE Trans. Wireless Commun.,vol. 2, no. 6, pp. 1150–1158, Nov. 2003.

[12]L. Xiao, S. Zhou, and Y. Yao, “QoS-oriented scheduling algorithm for mobile multimedia in OFDM,” in Proc. IEEE PIMRC, Sep. 2003,pp. 545–549.

[13]Prof. Shie-Yuan Wang, Chih-Liang Chou, and Chih-Che Lin “The GUI User Manual for the NCTUns 4.0 Network Simulator and Emulator” Produced and maintained by Network and System Laboratory, Department of Computer Science,National Chiao Tung University, Taiwan

[14]Prof. Shie-Yuan Wang, Chih-Liang Chou, and Chih-Che Lin “The Protocol Developer Manual for the NCTUns4.0 Network Simulator and Emulator” Produced and maintained by Network and System Laboratory, Department of Computer Science,National Chiao Tung University, Taiwan

[15]李蔚澤,許家華 “WiMAX技術原理與應用瞭解寬頻無線網路”