| Summary: | 碩士 === 國立臺灣師範大學 === 應用電子科技學系 === 100 === In this thesis, an improved slot reservation scheme is proposed that can effectively reduce the transmission delay of emergency safety messages. In our proposed scheme, each vehicle must first choose one vehicle from its neighbors as its transfer vehicle, and then makes its slot reservation as close as possible to the reserved slot of its transfer vehicle. It is shown from simulation results that our proposed scheme can effectively improve the transmission delay of emergency safety messages than other TDMA approaches proposed previously in the literature. In addition, under the DSRC architecture, a cluster-based multichannel communications scheme has been proposed previously, which integrates the clustering with contention-free/ contention-based MAC protocols. In order to improve channel utilization for non-real-time data transmissions, a hybrid channel allocation scheme is proposed in this paper, in which the channel selection is determined not only locally, but also globally. This helps to efficiently utilize the data channels, while preventing from hidden terminal problems.
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