Browsing by Author "Li, Yu-Wei"

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Design and Implementation of A more Realistic Radio Propagation Model for Wireless Vehicular Networks over the NCTUns Network Simulator
(2011)
Wang, Shie-Yuan
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Wang, Po-Fan
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Li, Yu-Wei
;
Lau, Lee-Chin
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資訊工程學系
Today, Intelligent Transportation System (ITS) applications has made a great impact on improving the quality and efficiency of the transportation system. This achievement has attracted researchers to propose more ITS applications, particularly to improve the transportation safety through Vehicular Ad Hoc Networks (VANETs). The major difficulty faced by these researchers is the verification of their proposals or ideas through field-trials or real-world experiments. Therefore, VANET simulator becomes the best and the most economical alternative to verify the validity and reliability of a proposed ITS application. Among all the VANET simulators, the NCTUns 6.0 appears as one of the most powerful tool due to its integrated platform of network simulation and microscopic traffic simulation. To further enhance the capability of NCTUns 6.0, we design and implement a more realistic radio propagation model, specifically for VANETs simulation. Through extensive simulations, it is shown that the adoption of a more realistic channel model has greatly affected the vehicles' behavior, as compared to the commonly used two-ray ground channel model.
Evaluations of Intelligent Traffic Signal Control Algorithms under Realistic Landmark-based Traffic Patterns over the NCTUns Network Simulator
(2012)
Wang, Shie-Yuan
;
Li, Yu-Wei
;
資訊工程學系
;
Department of Computer Science
In this paper, we use the NCTUns network simulator to study intelligent traffic signal control algorithms. NCTUns is both a microscopic traffic simulator and a network simulator. We imported the real-life map of a district of the Taipei city into NCTUns to let simulated vehicles move on the roads of the imported map. Then, we used a new and unique feature of NCTUns - each simulated vehicle moves towards its assigned landmark on the map as its destination, to create more realistic traffic patterns in the studied district. With these realistic settings, we studied an intelligent traffic signal control algorithm that has been proposed in the literature. We found that this algorithm has unfairness problems and thus we proposed two mechanisms to improve it. Our simulation results show that, when compared with the original algorithm, the improved algorithm can further reduce the average time needed for a vehicle to reach its destination. In addition, the improved algorithm can mitigate the unfairness problem.