• Journal of the Korean Society for Railway
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• v.7 no.2
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• pp.9-12
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• 2004

철도에서의 정보제어시스템은 열차무선망을 제외하고는 지금까지 유선전송망에 대부분 의존하고 있으며, 철도선로를 따라 대용량의 전용회선을 포설할 수 있다는 측면에서 효과적으로 설치가 가능하고, 안전성과 신뢰성의 측면에서도 우수성이 입증되었다. 그러나, 정보화가 진전됨에 따라, 여객서비스나 철도시스템 제어기능의 강화 측면에서 전송계통의 유연화와 정보교환개소의 확대가 요구되고 있으며, 유선전송으로는 이러한 요구에 충분히 대응할 수 없게 되었다. (중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6604-6610
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• 2015

In this paper, an efficient Wireless Access in Vehicular Environment (WAVE) packet transmission scheme for railroad communication is proposed. WAVE communication is a wireless local area network (WLAN) based communication and it is developed to be suitable for vehicular communication. There has been a lot of study on WAVE's applicability to Intelligent Transport System (ITS). As one of main transportation methods, by using WAVE, quality of railroad communication including WLAN based Communication Based Train Control (CBTC) can be enhanced and variety of railroad communication systems can be integrated into WAVE. However, there are technical challenges to adopt WAVE in railroad communications. For the simplest single-PHY WAVE, time division alternation of 50ms between Control Channel (CCH) and Service Channel (SCH) is required. Since there are delay sensitive railroad traffic types, alternation operation of CCH and SCH may cause performance degradation. In this paper, after identifying a couple of problems based on detailed analysis, a novel packet transmission scheme under railroad environment is proposed. In order to verify if the proposed scheme meets the requirement of railroad communication, WAVE transmission is mathematically modeled.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.568-570
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• 2018

Currently, with rapid progress and supply of mobile communication technology, LTE(Long Term Evolution) technology is expanded and widely used to industrial and emergency communications beyond earlier smart-phone based service. In this paper, transmission performance of voice traffic, one of railway communication service based on LTE-R as an application field of LTE technology, is analyzed. This study is performed performance analysis with level of application service and consider effects of satisfaction level for users. Computer Simulation based on ns(Network Simulation)-3 is used for analysis and VoIP(Voice over Internet Protocol) specification is used for voice traffics. Results of this paper is used to implement LTE-R networks and develope application services over LTE-R network.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.3
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• pp.207-213
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• 2023

The control center of an urban railway operator provides railway users with various information on railway use through a 1:N same-time broadcasting system. However, the facilities of the broadcasting system are aging, exposing many limitations in meeting the needs of urban railway users who have become familiar with mobile services. To overcome these challenges, this study analyzed the mobile-based same-time broadcasting services using location information of urban railway users and the requirements of various stakeholders (urban railway users, an operator, and external service providers, etc.) to suggest optimal service models and physical structures. Through this study, it aims to secure safer operations of urban railway as well as to improve better disaster responses through rapid and efficient spread of the situation in case of disaster.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.417-419
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• 2016

Internet of things(IoT) services should be available to provide unattended operation in a remote area, long battery life, low-cost infrastructure, two-way communication platform. Urban transit in Busan is made up of the wire-based infrastructure except for voice infrastructure of transmit/receive and new data infrastructure is required for Internet of things(IoT) services. Urban transit environments in Busan were analyzed in order to apply LoRa Wireless Network(the standard communication way of IoT) and proposes a building after a Disaster Evacuation System.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.893-895
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• 2014

Railway dedicated frequency bandwidth allocation matters are being discussed actively before an introduce of wireless communication based train control system to korean railway industry. Allocating the frequency band, which has great value as a public resource, for suitable use with right amount is particularly important, because of equity in other fields and valuable use of limited resources. In this paper, the feasibility about stable railway communication network operation based on LTE in diverse frequency bandwidth will be discussed with solicitous simulation.

• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.357-359
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• 2021

Railway system as a mass transportation is under progress to smart railway system beyond high speed and automation era. Communication network technology including 5G-R(5th Generation - Railway) mobile communication technology and information convergence technology of Big Data, Deep Learnig, AI(Artificial Intelliegnce) and Block Chain have to be used for implementation and operation of this smart railway system. In this paper, a communication network structure is suggested for this smart railway system. This suggested smart railway commnuication network structure is composed with layered structure of plane unit for safety operation of high speed railway, railway system management and customer services, and also have some complexed function of each plane. Results of this study can be used for smart railway communication network implementation, operation and managements, development of railway communication standards.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.6
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• pp.659-664
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• 2015

The current railway wireless network uses various communication scheme depending on the section of railway. Therefore, in the train, it is required a specific communication device for the corresponding communication scheme to communicate and exchange data with the control center. To enhance data rate and support various services, LTE-R scheme has been developed for the next generation railway communications. To use both the existing communication and LTE-R schemes, it is required an integration method for encompassing all communication schemes. In this paper, we overview existing railway communications and LTE-R scheme. Then, we develop a network integration method which can be applied by using one terminal in the train. In addition, implementation issues for the integration are also considered.

• Information and Communications Magazine
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• v.26 no.6
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• pp.16-22
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• 2009

최근에는 이동환경에서의 고속 위성통신 서비스에 대한 요구가 증가하고 있는 추세이며, 이러한 요구를 만족시키기 위해 유럽 및 북미지역에서는 지난 수년간 Ku대역을 활용한 고속이동체 대상의 이동형 위성통신 시스템 개발이 활발히 진행되고 있다. 하지만 기존의 이동형 위성통신 시스템은 수십 Kbps 정도의 전송속도를 제공하기 때문에 고속열차와 같이 다수의 그룹 사용자들을 대상으로 한 위성 인터넷 및 방송서비스 제공에 한계가 있다. 또한, 철도 운행구간에서 발생하는 N-LOS 환경에 대처하는 기술의 부재로 서비스 가용도가 크게 저하된다. 본 논문에서는 고속열차 승객을 대상으로 위성무선연동 전송기술을 이용하여 지상무선망과 동일한 수준의 끊김 없는 인터넷 서비스 및 위성방송 서비스를 제공하기 위한 이동형 광대역 위성 접속 시스템에 대해 기술한다. 고속열차를 대상으로 이러한 서비스 제공을 위해서는 터널이나 역사(Railway Station)와 같은 N-LOS 환경에 대한 대처기술이 필요하며, LOS 환경에서도 철로상의 신호열화 현상에 대한 극복기술이 필요하다. 본 논문에서는 고속열차를 대상으로 한 이동형 위성통신 서비스에 대한 국내외 연구개발 동향 및 국제 표준화 동향에 대해 기술한다.