• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1533-1540
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• 2007

The most critical function of the Communication Based Train Control system is wayside and on-board Radio communication. Radio communication must be safely made without errors. The standards for CBTC has not been established yet, and research on Radio communication systems for use in Train control systems adopting CBTC system such as the magnetic levitation train must continue. This paper will discuss the characteristics of Radio communication technology currently used domestically such as GSM-R, IEEE 802.11, TETRA, MESH, and WiMAX/WiBro, and will investigate the potential possibility of applying them to Train control systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4496-4502
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• 2010

In this paper, for the purpose of improving the future domestic train control systems and securing interoperability according to the global development trends of train control systems, we present the test results of communication interfaces to verify the interoperability between CBTC wayside units tentatively installed in Bundang line that is one of the metropolitan area rail transit systems, and the CBTC onboard units developed through the national R/D project. The CBTC onboard equipment developed, has finished its installation and trial tests in the Bundang shunting yard. For the interoperability test, we should make an interface test with wayside equipment tentatively installed in Bundang line. Due to the safety-critical characteristics of train systems, the site test in the section where the wayside equipment is installed, leads to a danger against safety. Therefore, by way of constructing a simulation environment of train control systems, we confirm the T/R data systems of the equipment for interoperability and test the interoperability by applying these systems to developed CBTC onboard equipment.

• International Journal of Railway
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• v.3 no.2
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• pp.39-45
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• 2010

The RF-CBTC (Radio Frequency-Communication Based Train Control) System is a communication system in railroad systems. The communication method of RF-CBTC system is the wireless between the wayside device and on-board device. The wayside device collects its location and speed from each train and transmits the distance from the forwarding train to the speed-limit position to it. The on-board device controlling device controls the speed optimum for the train. In the case of the RF-CBTC system used in Korea, transmission frequency is 2.4 [GHz]. It is the range of ISM(Industrial Scientific and Medical equipment) band and transmission of voice and data is performed by CDMA (Code Division Multiple Access) method. So noises are made in the AWGN (Additive White Gaussian Noise) and fading environment. Currently, the SNR (Signal to Noise Ratio) is about 20 [dB], so due to bit errors made by noises, transmission of reliable information to the train is not easy. Also, in the case that two tracks are put to a single direction, it is needed that two trains transmit reliable voice and data to a wayside device. But, by noises, it is not easy that just a train transmits reliable information. In this paper, we estimated the BER (Bit Error Rate) related to the SNR of voice and data transmission in the environment such as AWGN and fading from the RF-CBTC system using the CDMA method. Also, we supposed the SNR which is required to meet the BER standard for voice and data transmission. By increasing the processing gain that is a ratio of chip transmission to voice and data transmission, we made possible voice and data transmission from maximally two trains to a wayside device, and demonstrated it by using Matlab program.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.455-468
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• 2014

This paper presents seamless hand off implementation suggesting algorithm and Measuring /testing at the tunnel environment in order to derive the ideal value of wireless data transmission in RF-CBTC train control system modeled by Shinbundang Operation System. In addition, it proposes the ideal value(-57dB) for reducing the re-transmission or frequency interference rate and demonstrates frequency optimization which enables highly reliable data communication in Train control system using wireless communications. Based on these result, Shinbundang phase 2 plan to apply to this system.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.82-87
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• 2005

The new technology with Wireless LAN (WLAN) is implemented to the railway system, which is attached importance to safety and reliability. Railway control system based on WLAN that is called CBTC (Communication Based Train Control) is being developed by the advanced nations in this field and The system is applied to a new train line and a renovation for outworn equipment. The CBTC system has many merits about increase of capacity, reduction of headway and cost reduction etc.. Therefore, that is come into spotlight to the advanced railway company and the companies have being developed the system. So, we have developed the CBTC system for standardization and localization of the railway signal system.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1401-1406
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• 2007

There is growing interest in CBTC(Communication Based Train Control) system in accordance with the development of the communication technologies. The CBTC system, which adopts the moving block, has advantages such as headway and installation cost reduction compared with the existing system with fixed block. For the moving block system, it is required to locate the trains in real-time. Based on EPLRS(Enhanced Position Location Reporting System) technology, the train position can be provided only through the communication between radios. This paper introduces EPLRS based train detection method and verifies its effect by instance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.115-121
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• 2008

The communication-based train control (CBTC) technology is a kind of railway signaling technologies and is to control the train operation through communication. A project adopting the CBTC technology is in progress and its object is to develop interoperable and interchangeable subsystems. Thus the purpose of this paper is on how to develop the required subsystems and integrate them successfully without sufficient design information at the system level. Accordingly this project shall require the integration and test at the system level. In order to do so, a top-level system specification shall be needed, which is not available in the current phase of the project. The main objective of the test and evaluation activities is to see whether the developed system meets the system specification. In this paper, we describe how the test and evaluation can be carried out based on the subsystems design specifications, considering the system architecture and the operation concept of the existing system as well.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1370-1378
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• 2008

In the system necessary for safety such as the train control system, to make train control information be sent correctly is very important. In the case of the system such as RF-CBTC(Radio Frequency-Communication Based Train Control), sometimes failure in correctness of train controlling information may happen because the information is sent throughout wireless transmission between on-board system of a train and wayside transmitter, and then, it is exposed to noises. Of RF-channel interference, there are various forms. Under the environment of mobile telecommunications, adjacent-channel interference and Co-channel interference are in trouble, and under the environment of the wireless LAN, inter-symbol interference is in trouble. Also, the system of the cellular CDMA mobile telecommunication is affected on the RF-channel interference such as Doppler effect, multi-cell interference, and other users' intervention. In this paper, we analyzed the effect of the train control information related to fading, intervention and other noises made in the underground interval and explained the transmission characteristics numerically. Furthermore, we calculated the mean of the error terms by increasing users in the system of the cellular CDMA. As the method for decrease the error term of sent information, we represented the way adjusting the arrangement of antennas, and we did the model related to the system of RF-CBTC in which the location of an antenna is calculated with really measured value of the transmission characteristics and the way confirming reliability of the wireless transmission.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.357-360
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• 2003

Improvement is required to solve problems depending on long term use of signal equipment in the existing city railroad and to raise quality of passenger services. Accordingly, for more efficient improvement, we examined the procedure of executing construction of the communication based train control system in Korean city railroads, which is globally studied. The procedure of executing construction of the system is to present a plan for construction first of ail and then to prepare a strategy for construction of the system. It is required to establish a procedure for execution in each step depending on the prepared strategy and then to establish a detailed execution plan. We studied such an execution procedure, divided the execution procedure for application of the train control system through five steps to prepare the execution procedure.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.953-957
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• 2005

Light Rail Transit(LRT) Systems with transport capacity between subway and bus(5,000-25,000 persons per hour) are being carried on over 100 lines around the world. In Korea, to solve the urban transportation problem, the introduction of LRT system has been proceeded positively. It is planned to develop the Korean standard LRT system in which safety, efficiency and cost effectiveness are emphasized. So we were able to make proto type of Rubber tired AGT system for LRT. This is capable of driverless operation using CBTC(Communication Based Train Control) of Moving Block System and is currently making an experiment for reliability in test-line. This study is focused on verifving the train tracking with CBTC in driverless and ATO mode through implementing the examination.