Adaptive TUF Packet Scheduling Scheme for OFDMA-based WiMAX Systems 陳瑞奇, 林新力, 黃惠藩 亞洲大學資訊工程系 Nov. 22, 2008

Outlines Introduction Conventional Time-Utility Function based Scheduling Algorithms Adaptive TUF (A-tuf) Scheduling Scheme Simulation Results Conclusion

WiMAX (IEEE 802.16e) Worldwide Interoperability for Microwave Access Physical (PHY) Layer:正交分頻多重存取(Orthogonal Frequency-Division Multiple Access; OFDMA)技術 從媒體存取控制(MAC)層的角度可分為 聯網(Mesh)技術 點對多點(Point to multipoint; PMP)技術 (最常用且技術最成熟)

PMP WiMAX的網路連結方式 SS:Subscriber Station BS:Base Station ASN-GW:有線網路閘道, 可與外界網路做溝通

PMP WiMAX網路實際運作可能範例 M.S. Kuran and T. Tugcu, "A survey on emerging broadband wireless access technologies," Computer Networks, vol. 51, no. 11, pp. 3013-3046, Aug. 2007.

IEEE 802.16e所制定的五個QoS服務型態 B. Li, Y. Qin, C.P. Low, and C.L. Gwee, "A Survey on Mobile WiMAX [Wireless Broadband Access]," IEEE Communications Magazine, vol. 45, no. 12, pp. 70 - 75, Dec. 2007.

Scheduling /Allocation Framework Leonardo Badia, et al., "On the Impact of Physical Layer Awareness on Scheduling and Resource Allocation in Broadband Multicellular IEEE 802.16 Systems," IEEE Communications Magazine, vol. 45, no. 12, pp. 70 - 75, Dec. 2007.

Time-utility function for NRT traffic in UEPS algorithm S. Ryu, B. Ryu, H. Seo, and M. Shin, "Urgency and efficiency based packet scheduling algorithm for OFDMA wireless system," in Proc. IEEE ICC 2005, vol. 4, pp. 2779- 2785, May 2005.

TUF for RT traffic in UEPS algorithm S. Ryu, B. Ryu, H. Seo, and M. Shin, "Urgency and efficiency based packet scheduling algorithm for OFDMA wireless system," in Proc. IEEE ICC 2005, vol. 4, pp. 2779- 2785, May 2005.

Time-utility function for RT traffic in Shimizu’s algorithm (pattern A) Y. Shimizu, R. Zhou, and I. Sasase, "Packet scheduling algorithm with modified time-utility function to improve nrt throughput in OFDMA system," in Proc. IEEE PacRim 2007, pp. 545-548, Aug. 2007.

Time-utility function for RT traffic in Shimizu’s algorithm (pattern B) Y. Shimizu, R. Zhou, and I. Sasase, "Packet scheduling algorithm with modified time-utility function to improve nrt throughput in OFDMA system," in Proc. IEEE PacRim 2007, pp. 545-548, Aug. 2007.

Dynamic time-utility function for RT traffic in proposed A-TUF scheduling scheme

Maximum and minimum MSTI of dynamic time-utility function for RT traffic in proposed A-TUF scheduling scheme

Simulation Parameters

Comparison of average delay of RT-UGS (VoIP) traffic between A-TUF and other two schemes

Comparison of average delay of RT-rtPS (Video) traffic between A-TUF and other two schemes

Comparison of average loss rate of RT-rtPS (Video) traffic between A-TUF and other two schemes

Conclusion An effective A-TUF packet scheduling scheme for WiMAX downlink transmission. lower RT packet delay less loss rate retains the NRT throughput performance a certain degree of fairness. Continue to study how to integrate other packet scheduling techniques to achieve the best usage of wireless bandwidth resources

感謝指教 ~Thank you!~