• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.2
• /
• pp.1-8
• /
• 2011

Traffic congestion is a source of significant economic and social costs in urban areas. Intelligent Transportation Systems (ITS) are a promising means to help alleviate congestion by utilizing advanced sensing, computing, and communication technologies. This paper proposes and investigates a basic and advanced ITS framework Advanced Traveler Information System (ATIS) using wireless Vehicle to Roadside (Centralized ATIS model: CA model) and Vehicle to Vehicle (DeCentralized ATIS model: DCA model) communication and assuming an ideal communication environment in the typical $6{\times}6$ urban grid traffic network. Results of this study indicate that an ATIS using wireless communication can save travel time given varying combinations of system characteristics: traffic flow, communication radio range, and penetration ratio. Also, all tested metrics of the CA and DCA models indicate that the system performance of both models is almost identical regardless of varying traffic demand and penetration ratios. Therefore, DCA model can be a reasonable alternative to the fixed infrastructure based ATIS model (CA model).

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.8 no.2
• /
• pp.53-59
• /
• 2009

Integrating a field of transportation and IT is becoming a novel solution to social and economic problems which was previously focused on the investment in infrastructures. It also created new areas of industry such as ITS and telematics. Especially, vehicle communication is being considered very important and DSRC is also important in the field of rational ITS in recent. DSRC OBE has come into wide use through ETCS. In the field of traffic signal control, the research to implement an optimal traffic signal control system using a real-time information of good quality is being carried out and also the study of WISDOM was successfully completed. This paper shows the development of Dynamic-Dilemma zone warning service utilizing WISDOM and the evaluation of a reliability and a practicality through the field test. While the proposed Dynamic-Dilemma warning system transmits an information of signal time optimized by WISDOM, the OBE which receives this information makes dilemma zone based on its location and speed and gives warning to a driver.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.8
• /
• pp.98-105
• /
• 2008

FlexRay is a high-speed communications protocol with high flexibility and reliability. It was devised by automotive manufacturers and semiconductor vendors and implemented as on vehicle LAN protocol using x-by-wire systems. FlexRay provides a high speed serial communication, time triggered bus and fault tolerant communication between electronic devices for automotive applications. In this paper, we first design the FlexRay communication controller, bus guardian protocol specification and function parts using SDL (Specification and Description Language). Then, the system is re-designed using Verilog HDL based on the SDL source. The FlexRay system was synthesized using Samsung $0.35{\mu}m$ technology. It is shown that the designed system can operate in the frequency range above 76 MHz. In addition, to show the validity of the designed FlexRay system, the FlexRay system is combined with automobile advance alarm system in vehicle applications. The FlexRay system is implemented using ALTERA Excalibur ARM EPXA4F672C3. It is shown that the implemented system operates successfully.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.54 no.8
• /
• pp.34-41
• /
• 2017

Vehicle to Infrastructure(V2I) communication means the technology between the vehicle and the roadside unit to provide the Intelligent Transportation Systems(ITS) and Telematic services. The vehicle collects information about the probe data through the evolved Node B(eNodeB) and after that eNodeB provides road conditions or traffic information to the vehicle. To provide these V2I communication services, we need a link adaptation technology that enables reliable and higher transmission rate. The receiver transmits the estimated Channel State Information(CSI) to transmitter, which uses this information to enable the link adaptation. However, due to the rapid channel variation caused by vehicle speed and the processing delay between the layers, the estimated CSI quickly becomes outdated. For this reason, channel interpolation and prediction scheme are needed to achieve link adaptation in V2I communication system. We propose the Advanced Discrete Prolate Spheroidal Sequence(ADPSS) channel interpolation and prediction scheme. The proposed scheme creates an orthonomal basis, and uses a correlation matrix to interpolate and predict channel. Also, smoothing is applied to frequency domain for noise removal. Simulation results show that the proposed scheme outperforms conventional schemes with the high speed and low speed vehicle in the freeway and urban environment.

• Journal of the Korea society of information convergence
• /
• v.5 no.2
• /
• pp.67-76
• /
• 2012

XML-based open protocol, XMPP users to pass messages to other users, which means that a decentralized communication network is the network infrastructure and enable it. In addition, XMPP servers using a professional server-to-server protocol to communicate with each other and decentralized social networks and collaboration framework provides an important possibility. In this paper, the features of XMPP messaging protocol is applicable to automotive telematics terminals XMPP-based platform design, and presence of two-way communication point for the problem, point-to-point session setup issues, security issues, compatibility issues, and to solve the scalability problem XMPP-based messaging system was implemented.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.9 no.2
• /
• pp.30-41
• /
• 2006

This paper proposes an e-logistics system supporting efficient vehicle moving trajectory management. Recent advances in wireless communications have given rise to a number of location-based services including logistics vehicle tracking, cellular phone user's location finding, and location-based commerce. Logistics systems typically entail tracking vehicles for purposes of the logistics center knowing the whereabouts of the vehicles and/or consignments. Moreover, storing and managing location trajectory of continuously moving vehicles and consignments is necessary for supporting efficient logistics plan and consignment. The proposed system is able to manage spatial objects in GIS as well as logistic information in the mobile environment. And for the efficiently managing and retrieving of transporting trajectory of logistics, we extend previous moving object indexing method, TB-Tree, to use multi-version framework and evaluate data updating performance. It is able to apply the proposed method to develop mobile contents services based on continuously changing location of moving object in the mobile environment.

• Journal of Platform Technology
• /
• v.11 no.6
• /
• pp.106-115
• /
• 2023

In this paper, we propose a sensor data sharing system for the safe and smooth operation of autonomous vehicles on two-way single lanes in traffic-isolated areas and implement the core module, the situational awareness technology. Two-way single lanes pose challenges for autonomous vehicles, particularly when encountering parked vehicles or oncoming traffic, leading to reversing issues. We introduce a system using infrastructure cameras to detect vehicles' approach, enter, and leave on twoway single lanes in real-time, transmitting this information to autonomous vehicles via V2N communication, thereby expanding the sensing range of the autonomous vehicles. The core part of the proposed system is the situational awareness of the two-way single lane using infrastructure cameras. In this paper, we implement this using object detection and tracking technology. Finally, we validate the implemented situational awareness technology using data collected from actual two-way single lanes.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.7 no.1
• /
• pp.92-100
• /
• 2008

The existing transportation systems is emerged as a major obstacle to solve the problems such as a traffic jam and the increasing cost for a distribution and a traffic safety. In hun, ITS targeting intellectual vehicles and transportation infrastructure like road and signals is getting more important and the standards of ITS wireless communication is also getting attention. New traffic control strategies are being developed to utilize real-time traffic information collected by detection method using ITS wireless technology. Especially, DSRC system is being expanded wit ETCS and the use of OBU is spreading. These infrastructures will have much influence on ITS industry and a profound study on the method of utilizing a present infrastructure is going on in various fields. The optimum traffic signal control system using quality real-time information through these infrastructure is under development and so is WISDOM. Accordingly, this paper proposes communication protocol utilizing DSRC to collect real-time traffic information in WISDOM.

• Journal of the Institute of Convergence Signal Processing
• /
• v.22 no.2
• /
• pp.64-70
• /
• 2021

Nowadays, there are significant interests in real-time remote control using wireless networks. In implementing real-time remote control, one important factor is delay performance of real-time control message. Especially, the technique to reduce jitter of delay is necessary in transmitting periodically real-time control message. In this paper, we proposed synchronized transmission to reduce jitter of delay, when real-time control message was transmitted through wireless networks. The proposed transmission kept synchronization between source node and wireless transmitter and controlled transmission instance to transmit real-tie control message with fixed delay in wireless networks. According to results of experiment in military unmanned vehicle system, the proposed transmission reduced jitter of delay as 32% as that of a non-employing case.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.8
• /
• pp.875-882
• /
• 2015

Recently, An introduction of communication based train control system both into greenfield and brownfield of urban transit network has been actively reviewed. However, since a number of line sections and rolling stock depots tends to be constructed based on track circuit for various reasons, necessity of inter-operation between two distinct train control system (CBTC, ATC) increases. Therefore, we propose a design of on-board signalling device that allows inter-operation of CBTC and ATC lines and a method to secure safe connection between these two lines without derailing point machine.