| Summary: | 碩士 === 國立雲林科技大學 === 電機工程系碩士班 === 97 === Recent years have seen an ever-increasing demand for wireless and mobile communications. However, the development of current wireless and mobile communications is overshadowed by high prices, limited access, and low transmission rate. In response to the drawbacks, the wireless metropolitan area networks standard—IEEE 802.16 (or WiMAX) standard—is proposed. IEEE 802.16 standard aims to provide high speed data transmission rate and easy deployment in remote areas. In addition, it can be used as a last mile broadband wireless access. IEEE 802.16 standard supports two configuration modes: Point to Multipoint (PMP) and Mesh. This thesis studies the IEEE 802.16 Mesh mode. In addition to establishing a direct communication link between a subscriber station and the base station, the IEEE 802.16 Mesh mode allows the subscriber station to use the hop-by-hop method to transmit data packets to the base station. Therefore, as far as the IEEE 802.16 Mesh mode is concerned, the routing and packet scheduling problem becomes one of the most important research issues. In this thesis, we design an efficient and interference-aware centralized routing tree algorithm which takes the number of interferences associated with a subscriber station into consideration in an IEEE 802.16 Mesh network. Our routing tree algorithm enables more subscriber stations to conduct simultaneous transmissions, which efficiently shortens the scheduling length, and increases both the channel utilization ratio and the system throughput. In other words, our routing tree algorithm is capable of enhancing the overall performance of the network. Simulation results show that our routing tree algorithm outperforms the IEEE 802.16 standard by achieving a 10 to 12 percent of decrease in the scheduling length, and a 10 to 12 percent of increase in both the channel utilization ratio and the system throughput. Compared with the two algorithms proposed by Hemyari et al., our routing tree algorithm achieves a 3 to 6 percent of decrease in the scheduling length, and a 3 to 6 percent of increase in both the channel utilization ratio and the system throughput.
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