• 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.

• 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.

• Journal of the Korean Society for Railway
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• v.16 no.6
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• pp.551-557
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• 2013

This research aims to conduct a study on the feasibility of the LTE communication method for developing a dedicated integrated railway wireless network. An empirical analysis was carried out by establishing a dedicated integrated railway wireless network in an approximately 12km section between Illo station and Daebul station on the Honam line. Korean wireless communication methods for railway safety are different depending on each line, which makes it difficult for railway workers to cooperate with. This causes various problems. There is the ever-present risk of accidents due to call disconnection between wireless communication systems, frequency interference from commercial networks, and crosstalk. This study verified the feasibility of the 4th generation communication system, LTE, over the dedicated integrated railway wireless network as a solution for the above mentioned problems. The result shows this communication system exceeded existing performance standards of Europe GSM-R in every test item despite the location constraint of train tracks on the base station establishment.

• Journal of the Korean Society for Railway
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• v.16 no.6
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• pp.510-518
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• 2013

These days, interest in radio networks for railways has increased both at home and abroad. In response to this trend, not only the existing radio networks which focus on railway control signals but also the next-generation integrated radio network that can send videos and manage mass storage data are actively being investigated. This paper proposes wireless communication methods to establish integrated radio networks for railways. The paper further suggests a candidate frequency band that could be allocated as the frequency band for railways among the frequency bands currently used in Korea. Based on this paper, we can expect that the domestic railroad will operate more efficiently and that security and convenience of the railroad will reach a superior level. In addition, the Korean integrated radio networks for railways, which cope with the changes in the global technology market, will be established.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.4
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• pp.379-386
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• 2016

As well as to operate a high-speed rail, our country with capability to produce high-speed train has developed a number of techniques, such as for a riding comfort improvement, automatic diagnosis for major electrical or mechanical parts, on board measurement for catenary systems and noise reduction of running rolling-stocks are still under development. In this paper, we describe the current status of operation technologies not only traditional railway wireless communication systems but also Long Term Evolution systems which would be deployed as soon as possible, like as in Europe, China and the United States. In addition, we produced the domestic wireless communication networks for railway which KORAIL Corp. has been operating and the schemes and the plans of HSR field test for the fourth generation mobile communication which should be enforced by national research and development.

• Journal of the Korean Society for Railway
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• v.16 no.6
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• pp.519-527
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• 2013

Mobile radio technologies have evolved in the railway industry offering seamless connectivity and various functionalities to improve railway service. Recently, advanced mobile communication technologies have enabled a new level of railway customer services with more efficient railway operation. Since the LTE mobile communication technology offers many benefits and better performance for new railway services, it is considered to be a strong candidate for the future railway mobile telecommunication. However, communication networks in the railway sector are critical for secure operation and have stringent requirements for reliability and safety. In this paper, we explain the requirements for the future railway mobile telecommunication. The LTE, which would be the future railway mobile technology, is analyzed against these requirements. We also introduce the current state of standardization for the future railway mobile telecommunication and its implementation plan.

• 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.

• 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.

• Journal of the Korean Society for Railway
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• v.9 no.3 s.34
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• pp.257-263
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• 2006

This paper presents an optimization approach to the configuration of train radio communication network for CBTC. The target specifications of CBTC communication systems are derived from technical requirements for CBTC. The proposed communication system has a ring-topology backbone communication network between stations and a radio network based on IEEE 802.11b wireless tan between trains and wayside devices. The proposed method has been applied to the standardization of the signalling system of urban transits.

• Journal of the Korean Society for Railway
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• v.17 no.6
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• pp.402-409
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• 2014

Wireless local area network (WLAN) is a widely used wireless access method due to its easy usability and excellent performance. However, its performance degrades significantly as the number of users increases. In busy train stations, where the number of WLAN users are large and, more importantly the number of simultaneous packet transmission attempts is extremely large due to the time synchronization upon train arrival, the packet transmission delay problem is very severe and almost impossible for WLAN stations to initiate communication with WLAN networks. In this paper, a novel distributed WLAN access scheme for efficient WLAN communication in busy train stations is proposed. Using the proposed scheme, WLAN access delay can be significantly reduced under highly congested traffic environments. Therefore, a significant performance enhancement for the WLAN performance used in the Communication Based Train Control (CBTC) can be achieved.