Summary: | 碩士 === 雲林科技大學 === 電機工程系碩士班 === 96 === The rapid development of broadband wireless access technology has fueled more and more application or services with high-speed wireless data transfer. Among others, WiMAX, the Worldwide Interoperability for Microwave Access, is a promising technology based on IEEE 802.16 standards. WiMAX supports two generic modes of connectivity: point-to-multipoint and mesh. The former refers to a paradigm of a base station providing its subscriber stations (SSs) with direct connection services, while the latter allows for multi-hop communication among SSs themselves. This thesis is focused on load sharing in a WiMAX mesh network. We avail ourselves of adaptive modulation and coding techniques at the physical layer to accommodate centralized scheduling at the base station site. Further, inspired by the Hungarian method, we design a means to share workloads of processing and routing data traffic among SSs in accordance with network dynamics. In our architecture, when a link is considered congested, the connectivity of involved SSs will be re-arranged accordingly, so as to shift some load to less-occupied SSs elsewhere. As a result, SSs in the mesh network can be kept evenly utilized to the greatest extent, preventing network-wide routing paths from going through only a few SSs that form bottlenecks in the entire system. Simulation results show that, when compared with counterpart schemes, our proposed approach can achieve appreciable performance improvement. Performance evaluation indicates the effectiveness of our proposal in practice.
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