• The Journal of Korean Institute of Communications and Information Sciences
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• 제40권3호
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• pp.595-601
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• 2015

These days, research related to Intelligent Transportation System (ITS) technology is being widely considered. ITS is inevitable for future transportation systems to reduce accidents, congestion, and offer a smooth flow of traffic. The use of Visible Light Communication (VLC) in ITS systems has been considered widely because of its EMC/EMI free and LED infrastructure reusable properties. Among the VLC schemes, this study analyzed the performance of the Color Shift Keying (CSK) scheme under a Vehicle-to-Infrastructure (V2I) downlink scenario to verify the capability of CSK as a communication tool for ITS. By modeling daylight noise using the modified Blackbody radiation model, this study examined the performance of V2I VLC under daytime conditions. The relationship between BER, the communication distance, and the amount of ambient-light noises under the pre-described V2I scenario were determined by simulations.

• Journal of Institute of Control, Robotics and Systems
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• 제18권5호
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• pp.453-464
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• 2012

This is a research of an adaptive longitudinal control system for situated cognition in wide range, traffic accidents reduction and safety driving environment by integrated system which graft a road infrastructure's information based on IT onto the intelligent vehicle combined automobile and IT technology. The road infrastructure installed by laser scanner in intersection, speed limited area and sharp curve area where is many risk of traffic accident. The road infra conducts objects recognition, segmentation, and tracking for determining dangerous situation and communicates real-time information by Ethernet with vehicle. Also, the data which transmitted from infrastructure supports safety driving by integrated with laser scanner's data on vehicle bumper.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• 제8권2호
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• pp.33-40
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• 2018

There are lots of literature about connected car system from industry and academia. The connected car is a smart car integrated with IT technology that is connected to people, vehicles and traffic management systems. It is important to V2I (vehicle to infrastructure) communication which is the connection between the vehicle and the infrastructure. CIM (cooperative intersection management) is a device to manage the communication between vehicle and infrastructure. In this paper, we analyze two intelligent vehicle control methods using CIM at non-signalized intersections. In the first method, a vehicle to pass through intersection needs to reserve a resource of intersection. In the second method, trajectory patterns on pre-planned vehicles are classified to pass through intersection. We analyze case studies of two methods to be implemented by DP(dynamic programming) and ACO(ant colony optimization) algorithms. The methods can be reasonably improved by placing importance on vehicles or controlling speeds of vehicles.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제18권4호
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• pp.183-189
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• 2018

With the recent advancement of vehicle wireless communication technology, many vehicular clouds have been proposed. The existing research focused on cloud services through data collection based on vehicular networks of mobile V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure). In this paper, we present a vehicular datacenter model that utilizes the vehicle in the parking space as a resource for the datacenter. Also, we derive resource allocation strategy based on the expected execution time considering the leave rate of each vehicle in our vehicular datacenter model. Simulation results show that our proposed resource allocation strategies outperform the existing strategy in terms of mean execution time.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• 제8권3호
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• pp.122-131
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• 2009

Ubiquitous-Transportation sensor network is able to realize a vehicle ad-hoc network. Since there are some problems in an existing ITS system, the new technology and traffic information strategies are requirements in this advanced system, u-TSN. The purposes of this paper is to introduce the components on u-TSN system, establish new traffic strategies for this system, and then evaluate these strategies by making a comparative study of ITS and using micro traffic simulator, AIMSUN. The strategy evaluated by AIMSUN is position-based multicast strategy which provides traffic information to vehicles using V2I (vehicle to Infrastructure) communication. This paper focuses on the providing real-time route guidance information when congestion is occurred by the incidents. This study estimates total travel time on each route by API modules. Result from simulation experiments suggests that position-based multicast strategy can achieve more optimal network performance and increased driver satisfaction since the total accumulated travel times of both the major road and the total system on position-based multicast strategy are less than those on VMS.

• The Journal of Korean Institute of Information Technology
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• 제16권11호
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• pp.69-76
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• 2018

As for V2I(Vehicle-to-Infrastructure) systems with energy-constrained RSUs(Road Side Units), the previous data delivery strategies have not considered the aspect of energy usage at RSUs. A new data delivery strategy has been proposed to determine the RSU's participation in data delivery based on the probability dependent on the RSU's remaining energy, and it showed the lower data delivery time than the previous approaches. In this paper, we propose methods to analyze the number of RSUs participating in data delivery and the variations of RSUs' energy value for the consecutive data deliveries. As a numerical result, compared with the previous strategy, the probability-based data delivery strategy shows the lower number of participating RSUs and the increased average energy value of all RSUs. In addition, from the analytical results, we propose considerations for the real implementations of the similar systems.

• The Journal of the Korea institute of electronic communication sciences
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• 제17권4호
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• pp.617-624
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• 2022

The small electric vehicles equipped with V2X(vehicle to everything) systems may provide more information and function to the existing navigation system of the vehicle. The key components of V2X technology include V2V (vehicle to vehicle), V2N(vehicle to network) and V2I (vehicle to infrastructure). This study is to design and implementation of VI type E-PTO which is interfaced with external equipments, the work designs the components of E-PTO such as DC/DC converter, DC/AC converter, battery bidirectional charging system etc. Also, it implements the devices and control systems for driving. The test results of VI type E-PTO components showed allowable 10% requirements of transient voltage variation rate and recovery time within 100ms for start/stop and normal operation.

• Journal of Advanced Marine Engineering and Technology
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• 제40권10호
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• pp.899-905
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• 2016

Wireless access in vehicle environment (WAVE) communication is currently being researched as core wireless communication technologies for cooperative intelligent transport systems (C-ITS). WAVE consists of both vehicle to vehicle (V2V) communication, which refers to communication between vehicles, and vehicle to infrastructure (V2I) communication, which refers to the communication between vehicles and road-side stations. V2I has a longer communication range than V2V, and its communication range and reception rate are heavily influenced by various factors such as structures on the road, the density of vehicles, and topography. Therefore, domestic environments in which there are many non-lines of sight (NLOS), such as mountains and urban areas, require optimized communication channel modeling based on research of V2I propagation characteristics. In the present study, the received signal strength indicator (RSSI) was measured on both an experience road and a test road, and the large-scale characteristics of the WAVE communication were analyzed using the data collected to assess the propagation environment of the WAVE-based V2I that is actually implemented on highways. Based on the results of this analysis, this paper proposes a WAVE communication channel model for domestic public roads by deriving the parameters of a dual-slope logarithmic distance implementing a two-ray ground-reflection model.

• Journal of Korean Society of Transportation
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• 제28권4호
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• pp.167-175
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• 2010

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at the individual vehicle or platoon level through vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communication. It is necessary to develop a traffic flow management scheme to take advantage of the ubiquitous transportation system environments. This paper proposes an algorithm to advise the optimal speed for each vehicle according to the traffic flow condition. The algorithm aims to stabilize the traffic flow by advising the equilibrium speed to the vehicles speeding or crawling under freely flowing condition. And it aims to prevent or at least alleviate the shockwave propagation by advising the optimal speed that should dampen the speed drop under critical flow conditions. This paper builds a simulation testbed and performs some simulation experiments for the proposed algorithm. The proposed algorithm shows the expected results in terms of travel time reduction and congestion alleviation.

• Journal of Multimedia Information System
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• 제6권2호
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• pp.61-66
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• 2019

VANET (Vehicular Ad-hoc Network) is a mobile Ad-hoc Network which deals with the moving vehicles. VANET supports Intelligent Transport Systems (ITS) which is related to different modes of transport and traffic management techniques. VANETs enabled users to be informed and make them safer. VANET uses IEEE 802.11p standard wireless access protocol for communication. An important and necessary issue of VANET is to design routing protocols. In a network, communication takes place by the use of the routing protocols. There are mainly two types of communications used such as Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) in VANET. Vehicles can send and receive messages among them and also to and from infrastructure used. In this paper, AODV, DSR and DSDV are compared by analysing the results of simulation on various metrics such as average throughput, instant throughput, packet delivery ratio and residual energy. Findings indicates utilization of AODV and DSR is more applicable for these metrics as compared to DSDV. A network simulator (NS2) is used for simulation.