The Impact of Bandwidth Request Mechanism on Best Effort Connections in IEEE 802.16 WiMAX Networks

• Main Authors: Chang, Yu-Ting, 張毓庭
• Other Authors: Chao, Hsi-Lu
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/10731976360236852955

碩士 === 國立交通大學 === 資訊學院資訊科技產業專班 === 97 === Heterogeneous network scheduling becomes more and more popular. There are some papers do the research of heterogeneous network scheduling, and they use the concept that choosing the interface with the shortest transmission time. However, in those papers, they didn’t consider the impact of bandwidth request mechanisms. In uplink, bandwidth request mechanisms affect the bandwidth allocation, and in those papers, they cannot use their methods to estimate the delivery time in IEEE 802.16 WiMAX networks, because they just consider the data rates of different interfaces, they didn’t consider the effects of the bandwidth request mechanisms. So we study the impacts of bandwidth request mechanisms for Best Effort (BE) traffic in IEEE 802.16 WiMAX networks. In this thesis, we discuss the different bandwidth request mechanisms on Best Effort connections, and discuss two different contention-based mechanisms and two different piggyback-based mechanisms additionally. From the simulation results, we can know the conclusion that in heavy traffic load, we should use polling mechanism; in light traffic load, we should use contention mechanism and piggyback mechanism. By our study, the conclusion may help the IEEE 802.16 WiMAX MAC layer scheduler designers to design a more efficient scheduler for requesting bandwidth to increase the system performance.