Intelligent Transportation System (ITS)
ABSTRACT In intelligent transportation systems (ITS), transportation infrastructure is complimented with information and communication technologies with the objectives of attaining improved passenger safety, reduced transportation time and fuel consumption and ...
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ABSTRACT: Next generation vehicular communication environment will consist of heterogeneous radio access networks (RAN). For seamless connectivity, vertical handover is a mandatory requirement. A novel context aware vertical handover algorithm is presented here. TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), which is a multi criteria decision making (MCDM) tool, is used for the development of algorithm and MATLAB/SIMULINK is used as simulation platform. The optimum network is selected, based on multiple factors such as network traffic load, velocity of mobile station, data rate, usage cost and initial delay of network, among the available networks such as WiMax, WLAN and UMTS. This algorithm has been tested by simulating a virtual road traffic scenario. Variations in optimum RAN selection with vehicle speed keeping network traffic load constant and RAN selection with network traffic load keeping vehicle speed constant are shown graphically. The proposed algorithm is very simple yet powerful compared to the existing VHO algorithms and hence requires less execution time. Index Terms — ITS, Vertical handover (VHO), MCDM, TOPSIS, V2V and V2I.
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ABSTRACT: Variable speed limits (VSLs) as a mean for enhancing road traffic safety are studied for decades to modify the speed limit based on the prevailing road circumstances. In this study the pros and cons of VSL systems and their effects on traffic controlling efficiency are summarized. Despite the potential effectiveness of utilizing VSLs, we have witnessed that the effectiveness of this system is impacted by factors such as VSL control strategy used and the level of driver compliance. Hence, the proposed approach called Intelligent Advisory Speed Limit Dedication (IASLD) as the novel VSL control strategy which considers the driver compliance aims to improve the traffic flow and occupancy of vehicles in addition to amelioration of vehicle's travel times. The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle's characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions. The proposed approach takes advantage of vehicular ad hoc network (VANET) to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy. The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions.
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ABSTRACT: Always best connected" communication is the principal requirement for Intelligent Transportation System (ITS), which is a subset of 4G, to ensure vehicular safety. The next generation communication is characterized by heterogeneous radio access networks. The heterogeneous co-existence of access technologies with largely different characteristics creates a decision problem for determining best available network at a particular instant of time. A context aware vertical handover algorithm for vehicular communication is presented here. Integrated AHP (Analytic Hierarchy Process)-TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method is used for the development of algorithm and MATLAB/SIMULINK is used as simulation platform. Dynamic factors like received signal strength, and speed of the vehicle, static factors like initial delay for connection establishment, cost of service and user preference of application are considered. Sensitivity analysis is done to justify the design of the algorithm. This algorithm is specific to vehicular communication system and hence variation in network selection at different vehicle speed is shown. Key Words – Intelligent Transportation System (ITS), TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), Software Defined Radio (SDR), Sensitivity Analysis, Analytic Hierarchy Process (AHP), Quality of Service (QoS).