• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2795-2803
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• 2011

Due to speed acceleration, higher requirements have been put forward to high speed railway communication and signaling system. The railway applications, including intra-train, train to ground and trackside networks, demand larger bandwidth, higher reliability and shorter response time from railway communication networks to ensure security operation and passenger communication. However, the current railway communication and signaling system has lagged behind the railway development, so advanced communication technologies are needed to improve the current situation. This paper presents high speed railway communication and signaling system based on 4G LTE technology, introduces its network architecture, key technology and analyzes its technical advantages compared with GSM-R system. According to analysis, LTE based high-speed railway communication network is more effective and reliable.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.8
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• pp.729-734
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• 2016

The current domestic railway wireless communication networks transmit and receive data using several communication schemes such as VHF, TRS-ASTRO, and TRS-TETRA depending on the specific region. Recently, LTE scheme has been adopting in railway wireless communication systems to provide various services and increase reliability. It is critical to support the network interoperability between the existing communication schemes and new communication scheme for seamless data transmission. In this paper, we propose two interoperability schemes in railway communications networks, i.e., network oriented scheme and terminal oriented scheme. We consider the operation scenario for each scheme and compare two interoperability schemes. The practical implementation issues are also discussed based on suggested schemes.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1069-1074
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• 2021

Recently, mobile communication technology has new eras with supply of 5G commercial communication. 5G mobile communication service is currently supplied with city area, services will be quickly expanded to entire area of country. This mmWave based 5G mobile communication is under spreading for human communication with voice and Internet service. After completion of construction of this human communication, this technology will be expanded to industrial communications. Railway communication system is an example of this industrial communications. In this, performance of traffic transmission for railway communication network based on this 5G railway communication networks will be analyzed with computer simulations. Construction requirements of 5G railway communication networks will be suggested with this analysis results.

• Journal of the Korean Society for Railway
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• v.16 no.6
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• pp.534-539
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• 2013

The research about the Korean integrated wireless network for railways is in progress. The network integrates and complements the various railway functions. In addition, the network is trying to change from wire communication to radio communication. The activities for the railway frequency acquisition are also in progress for the implementation of the network. This paper analyzes the problems for the Korean railway communication networks. The problems revolve around the dispersed network structure, the limited functions, the different communication methods, the technology limitation for the communication methods, and the usage of the non-licensed band. Subsequently, we explain the current state and trend for the foreign communication of the railways. This paper suggests improvement plans for the problems and also explains the expected efficiency for the improvement plans.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2808-2813
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• 2011

According to opening the domestic existing lines and High-Speed Lines(HSL) depending on each section and phase-in, there were constructed in railway over state-of-the-art radio communication networks. Therefore, there have been 3 wireless communication networks in domestic railways in accordance with running sections as like VHF, TRS-ASTRO and TRS-TETRA. For instance, the VHF networks were constructed in exsiting lines and TRS-ASTRO were Kyungbu HSL phase-1 except Seoul-Kwangmyung section, downtown in Daejeon City and that of Daegu City. And it was constructed in DongDaegu-Busan section of Kyungbu HSL phase-2, Osong-Kwangju section of Honam HSL phase-1 and would be done in Kwangju-Mokpo of Hanam HSL phase-2 and Soosu-Pyungtaek of Metropolitan Area Line by TRS-TETRA. In this paper, we described some important problems of radio communication management and investigated current state of radio communication for railways. Moreover, we presented the necessity of integrated radio networks for domestic railways.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.3
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• pp.271-276
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• 2016

Cooperative networks enhance the overall communication performance by combining signals from relay nodes and direct signal. In this paper, we analyze the performance of cooperative communication systems which use mixed relaying protocols. By assuming several relay nodes exist between the source node and destination node, we consider the systems use not a single relaying protocol but both decode-and-forward and amplify-and-forward protocols randomly. We analyze the effect of each relying protocol for the overall system performance, and also consider the performance depending on the relay location. Differential modulation scheme which demodulates signal without channel state information is adopted where it can be applicable fast varying channel such as railway environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.197-199
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• 2021

High speed railway system is progressed to SRN(Smart Railway Network) having entirely automation function beyond each componet automations. It is necessity to use mobile communication technology of LTE-R(Long Term Evolution - Railway) and 5G-R(5th Generation - Railway) and information technology of convergence based on AI, Big Data, Deep Learning to construct this smart railway networks. In this paper, a communication structure is suggested for SRN. This suggested communication structure for SRN is composed to include safety operation of high speed train, railway system management and customer services, and also have complexing function of these each functions. Results of this study can be used for SRN construction and opeation, and development of railway communication standards.

• Journal of the Korean Society for Railway
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• v.16 no.4
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• pp.262-271
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• 2013

Wireless communication networks are recently taking an important role in railroad systems as railways now require high speed and high density operation with the aid of advanced information technology to improve maintenance efficiency and to handle passenger service growth. Train control systems are consequently changing from track circuitbased systems to communication-based systems. This paper analyses the role of wireless communication networks in recent railroad systems, reviews foreign cases, and then suggests a communication network constructing policy for increased transport capacity increase, securement of safety, and efficient train control.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.1
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• pp.10-17
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• 2010

Safety-critical systems related to the railway communications are currently undergoing changes. Mechanical and electro-mechanical devices are being replaced by programmable electronics that are often controlled remotely via communication networks. Therefore designers and operators now not only have to contend with component failures and user errors, but also with the possibility that malicious entities are seeking to disrupt the services provided by theirs systems. Recognizing the safety-critical nature of the types of communications required in train control operations, the communications infrastructure will be required to meet a number of safety requirements such as system faults, user errors and the robustness in the presence of malicious attackers who are willing to take determined action to interfere in the correct operation of a system. In this paper, we proposed the safety strategies employed in the railway communications and a security mechanism for Korean railway communication system. Also, we presented the developed means for validation and determination of communication safety based on the proposed security mechanism in the railway system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.527-530
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• 2017

LTE-R(Long Term Evolution-Railway) based on LTE technology is expected to use core communication technology for high speed railway as one of standards for railway communications. In this paper, transmission performance of video traffic as an application is analyzed on LTE-R networks. Performance is evaluated with compter simulation based NS(Network Simulator)-2, open video traffic is used, RTP(Real Time Protocol) is used for transmission protocol. Results and methods of this paper can be used for research and developmemt of LTE-R networks.