• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1095-1102
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• 2016

A TCS(Train Control System) is the core facility to ensure the safety and efficiency of train operations, it is difficult to have interoperability between the TCS suppliers. To ensure the interoperability between TCSs, there is a need for definition, validation and standardization on the system configuration, the functions of subsystems, the interface between subsystems an the system protocol. In this paper, we analyzed the completeness of the KRTCS(Korean Radio based Train Control System) specification, derived supplements what you need to apply the KRTCS specification to new urban lines.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.594-601
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• 2000

Communication Based Train Control System supports the easy maintenance ＆ management and also have the capability to send more informations than the existing one but is less expensive. Tolerance against fault/failure and reliable data transmission are very important issues with this system since it has the responsibility of man's safety. In this paper, we suggested the schemes to support the reliable transmission quality and fault safety. Also we verified through simulation.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1243-1250
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• 2008

LRT System Application Project is performed for the purpose of technical advancement and stabilization of K-AGT system from the viewpoint of practical use and commercialization. For those purpose, the performance test and evaluation procedure for signaling system are developed, and the scheme of verifying the performance and function of signaling system under multi-train and driverless control environment is being conducted. In general, the railway have kept their systems highly safe and reliable through the ongoing efforts over a period of many years. This has been achieved primarily by continuous improvements, which mean that there is a dearth of experience in the introduction of innovative new systems. Therefore it is said that comparing a new system that features a completely new architecture with a conventional one may be difficult. In this paper, we investigate the evaluation method for Radio based-Communication Based Train Control system from case study.

• 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.

• Journal of the Korean Society for Railway
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• v.19 no.6
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• pp.736-743
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• 2016

In accordance with the trend of higher speed and automation, the Train Control System is building on the technology of control methods using radio in the technology of exchanging information by wire, toward a wireless communication method that will be applied using LTE-R radio communication technology with $4^{th}$ generation LTE mobile communication a $2^{nd}$ generation GSM-R. Therefore, a standard specification suitable for the Korea Radio based Train Control System-2(below KRTCS-2) for the 350km/h class using wireless communication is created; a prototype based on the standard specification is installed on a high-speed train and is installed on a test section(Ik san-Jeong eup) on the Honam high speed line to ensure the reliability and safety of the standard specifications, which are verified through various performance tests. In the future, the standard specification that has been established as a national railway standard, and the standard specifications will be commercialized by applying the train control system to conventional and High speed railway lines.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1199-1204
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• 2004

In this paper, the DCS (Data Communication System) which is a main part of CBTC (Communication Based Train Control) system is consisted of radio based wireless communication system and optical based wired system. In the radio based wireless communication, the location of AP(Access Point) Enclosure and Antenna shall be optimized for the guaranteed communication channel between wayside and trains either open aired or tunnelled area. This study is introducing the way of determinating optimized positioning the radio based wireless communication equipment in Bundang Line. At this moment, this CBTC project for the KNR's (Korea National Railway) intelligent train control system are in installment phase therefore the simulation data can show only from lab equipment. After the phase I testing, more detailed data can be collected and advanced paper will be issued in a short time.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1044-1053
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• 2010

Transmitting correct train control information is important in a train control system which demands safety. The train control information includes the maximum speed of trains, position of preceding trains, incline of tracks and curve sections etc. A radio frequency-communication based train control system is influenced by the noise and interference because the train control information is transmitted by wireless between a on-board system and wayside system. The radio frequency-communication based train control system is a mobile communication system due to moving trains. The inter symbol interference(ISI) occurs by the multipath fading in the mobile ommunication system. As signal-to-noise ratio(SNR) is decreased by the ISI, the train control information is not received correctly. In case of tunnel section, numerous reflected waves exist. Therefore, the power density of receiver is decreased by difference among the received times, magnitudes, phases through the multipath. So, the train suddenly is stopped by the fail-safe operation in the train control system on account of decreasing the power density of receiver. In this paper, a line of sight model-(Additive White Gaussian noise(AWGN) channel), rayleigh and rician fading model are presented. Probability density functions which are related to the SNR are derived from the models. The fading phenomenon severely occurs as a result of analyzing the probability density functions. So, the space diversity method is used in order to reduce the fading effect and it is demonstrated by using Matlab program.

• Journal of the Korean Society for Railway
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• v.17 no.1
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• pp.35-42
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• 2014

This paper analyzes the hazard related to train control, the functional requirements for atrain control system(TCS) and the automatic train protection(ATP) functional allocation that ensures the interoperability of a radio communications-based TCS. In addition, the interoperability can be obtained using wireless communications technology standards and standardized functional allocations of TCS performed on the wayside and onboard. Using this information, an integrated operating system for a rail network can be constructed. The functional allocations of TCS that support interoperability, require hazard analysis of TCS and definition of the system requirements. The hazard factors for a TCS are confirmed through setting the train safety space control and train speed limit excess. Furthermore, this paper determines the impact of the hazard factors on the TCS and, defines the functional requirements for the TCS subsystems and the ATP wayside and onboard functional allocations.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1018-1020
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• 2008

Since radio communications based train control system requires considerable amount of information than track circuits based signalling system and these information have significant effects on train control system safety, it is essential to ensure information integrity. In addition, when track information has to be added or changed due to track installation, track maintenance (both corrective and preventive), any information changes must be reported to train control system as soon as possible. In this paper, we provide explanation on the equipment and its data structure. Also, we represent the results of a simulator application to check the information integrity generated by the equipment.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1023-1026
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• 2007

CBTC (Communication Based Train Control) is a railroad system, using wireless communication for data transmission between on-board units and ground units, that makes ground computer periodically collect position and speed data from each train and transmits the preceding train's distance data up to speed limit point so as to make on-board control unit control the optimum train speed. Due to the fact that wireless communication system for train control employs only limited frequency band and output frequency, a number of ground communication units should be installed at track-side; also a running train should carry out Handover function which maintains the communication by accessing a new communication channel of the adjacent on-board communication units in accordance with the output of received radio wave. Especially CBTC is largely dependent on Handoff function between ground communication units. Therefore, this paper provides the method of identification of hazard between ground communication units and on board units.