• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.10
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• pp.1028-1039
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• 2014

After DTV transition, frequency allocation to efficiently utilize 700 MHz band, which is remained as Digital Dividend, is in progress domestically and internationally. This paper investigates global frequency allocation of 700 MHz band and utilization of the band, and analyzes domestic wireless technology methods and requested frequency bandwidth by use. In addition, the paper suggests what needs to be considered in case of building public integrated radio network that focuses on disaster and safety network; the integrated radio network also includes railway network and e-Navigation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.51-58
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• 2019

The LTE system decided to build an integrated disaster safety communication network in order to cope with disasters quickly after the April 16, 2014 disaster, and 333 agencies in 8 areas will build a unified disaster safety communication network. It plans to integrate LTE-R, a railway integrated wireless network, and LTE-M, a land-based communication network, in the 700MHz band. LTE-R, a wireless integrated network, and the Ministry of Land, Transport and Maritime Affairs, are currently using VHF and TRS, which are voice communication-oriented communication systems, in order to cope with demand for high-speed railway service, With this possible LTE-R, it is possible to provide advanced services such as radio-based train control and improve railway safety. The company plans to invest KRW 1.1 trillion in new routes to be launched in 2018 and the existing route to be improved in the future, and to build up all routes of general and high-speed railways to LTE-R by 2027.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.1-8
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• 2020

The Ministry of Land, Infrastructure and Transport of Korea has been trying to spread integrated railway communication network technologies based on a major railway policy since 2012. As a result, the world's first commercial Long-Term Evolution - Railway (LTE-R) network was established on the Gangneung line (Manjong station - Gangneung station) and has been commercially operating as a railway communication system since 2017. Special function and performance requirements are needed for safe and efficient railway operations, such as group calls, emergency calls, functional addressing, and train control based on wireless communications. In this paper, we present functional and performance railway communications requirements that are based on European wireless railway communications systems. In addition, we measured communications characteristics and performance using a KTX field test on the Gangneung line to analyze the validity and reliability of the LTE-R network. Although the average Radio Frequency (RF) conditions were satisfied in the requirements, we found sudden communications quality degradation, such as Radio Link Failure (RLF) in some railway sections. We propose a way to improve performance and network installations based on in-depth analysis of LTE-R communications field-test 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.9
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• pp.1172-1179
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• 2020

With the establishment of the railway integrated radio network (LTE-R) environment, radio-based train control transmission and reception and various forms of service are provided. The smooth delivery of these services requires improved performance in a highly reliable and available wireless environment. This paper measured the LTE-R radio communication environment to improve radio communication performance of railway integrated wireless network reliability and availability, analyzed the results, and established the wireless environment model. Based on the built-up model, we also proposed an improved radio-access algorithm to control trains for improved reliability, suggesting a way to improve stability for handover that occur during open-air operation, and proposed an algorithm for frequency auto-heating to improve availability. For simulation, data were collected from the Korea Rail Network Authority (Daejeon), Manjong-Gangneung KTX route, which can measure the actual data of LTE-R wireless environment, and the results of the simulation show performance improvement through algorithm.

• 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.