• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.1-8
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• 2018

It is the content and scope of this study to analyze the problems of the current wireless service and the classification system of the radio station, and to examine the case of radio control in Japan and to establish a reasonable and efficient radio wave management plan. The results of this study can be used as basic data for reorganizing the legislation on radio wave enforcement ordinance, radio services and radio station classification standards. It is expected that it will be possible to improve the compliance and efficiency of the radio station licensing and inspection service while enhancing the policy compliance in the practical work by providing detailed explanations on the definition and classification system of the new radio task / radio station in the future.

• Journal of electromagnetic engineering and science
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• v.8 no.2
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• pp.64-69
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• 2008

In this paper, we have proposed the pattern adjustable base station antenna for WCDMA applications. The proposed antenna consists of an omni-antenna(sleeve monopole) and two movable reflectors. The two reflectors can be controlled by mechanically and used to adjust the horizontal pattern of the base station antenna. The antenna was designed, fabricated, and measured. The antenna covers the entire WCDMA band for VSWR<1.4. The measured antenna gain is more than 15 dBi over the operating frequency range. By changing the angle (a) and the distance (d) of the antenna, the pattern adjustment of the proposed base station antenna is found to be possible.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.2
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• pp.229-236
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• 2022

This article studied the radio station inspection method, which utilizes the 8T8R combiner to reduce 5G radio station inspection measurement times. It is a common that 5G radio station inspections measure RF (Radio Frequency) output signals, which correspond to the number of arrayed antennas individually. However, this study suggested a way to save the time spent on existing methods, by comparing measurement values of individual channels and 8T8R. As a result, it is confirmed that when the 8T8R combiner is used, not only the resulting value of radio station inspections was accurate, but also the measurement time being shortened by up to 8 times compared to existing method.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.210-215
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• 2003

At present, communication network for subway is making use of the train radio system for main network and normally established a base station every three subway station. It is talk over the telephone between a locomotive and the traffic control for careful train service. Besides, mobile telephone equipment is using for service improve and convenience to passengers such as 011, 016, 017, 019 and what not. However, the train radio system has been occurring a various problems when a state of emergency because it is able to compose only one communication route each base station zone. We could have improving like this problems through induce the TRS(Trunked Radio System), though because have been able to compose multilateral communication route in case of linking with LCX(Leaked Coaxial) cable which is established. Therefore, we could be able to a fitting meet the emergency as train firing etc.. and efficient use of limited frequency resources.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.216-222
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• 2003

Train control by radio based communication is one of the interesting new fields in train signal. The radio based control has more benefits, low headway and low construction and maintenance cost, than conventional control. In this paper, a safe and efficient train operation is introduced. Triple radio communications, train to train, train to station, and train to central traffic control, are used to increase the reliability. One of these communications channels has a fault; the others can take the functions of it. Absolute position of a train is transmitted to station via radio communication. In the station, the interlocking mechanism should be activated as the legacy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7A
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• pp.776-785
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• 2008

Compared with the existing cellular base station whose radio parameters are configured manually, the small base station named as self-configurable base station configures its radio parameters automatically by the central controller. When installing the self-configurable base station, it should be considered primarily that the seamless coverage for the target area is secured while the signal interference to the existing cellular service area must to be minimized. In order to achieve this, it is very important to select the correct radio parameters, e.g., transmission power and working frequency. In this work, we formulate and solve the optimization problem by using mixed integer programming to optimize the air parameter for the self-configurable base stations.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.379-388
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• 2020

The contents and scope of this study are to analyze the problems of the current radio service and radio station classification system, and to investigate the radio wave management cases in the United States to provide a reasonable and efficient radio wave management method. The results of this study can be used as basic data when revising the legal system regarding radio wave enforcement regulations, radio service and radio station classification standards. It is expected that in the future, a detailed commentary on the definition and classification system of new radio / radio stations will be prepared to increase policy compliance in practice, while contributing to enhancing the consistency and efficiency of radio station licensing and inspection.

• ETRI Journal
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• v.26 no.5
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• pp.493-496
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• 2004

An effective paging strategy is essential for improving the utility of radio channels. This paper proposes a two-step paging strategy which involves using base station paging agents to page a single cell at each paging. An analytical model is used to evaluate the performance of the proposed strategy. The proposed strategy is compared with the traditional simultaneous paging strategy and a recent proposal using the base station paging agents. The numerical results showed that the proposed strategy proficiently reduces paging cost on radio channels compared with other paging strategies.

• Journal of electromagnetic engineering and science
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• v.12 no.1
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• pp.94-100
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• 2012

Radio interference has been occurring in mobile communication services on the southern seashore in Korea. Monitoring the radio interference signal revealed that the main reason for the radio interference was a radio ducting signal coming from the seaside of Japan. In this paper, we have analyzed the effect of interference on WiMAX service using a 2.5 GHz frequency band between Korea and Japan. We focus on the interference scenario from base station to base station and we use the Minimum Coupling Loss (MCL) method for interference analysis and the Advanced Propagation Model (APM) for calculating the propagation loss in ducts. The propagation model is also compared with experimental measurement data. We confirm that the interfering signal strength depends on the antenna height and this result can be applied to deployment planning for each system with an interference impact acceptable to both parties.

• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.189-196
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• 1997

An oil tracking system that monitors the spilt oil trajectory by using GPS was developed. The system consists of a tracking buoy deployed on the oil spilt area and an onshore(or onboard) monitoring station. The tracking buoy is equipped with GPS, signal converter, handy radio and battery while the monitoring station includes a station radio, signal converter, antennas and PC. The hull shape of buoy is designed to effectively simulate the spilt oil movement at sea surface. Radio sets for HAM are used as a data transmitter and a data receiving station, and signal converter is also for amateur use. A field experiment was conducted and it was shown that the integrated system is relable and robust. The developed oil tracking system reveals reatively good performance at reasonable cost. In favorable environment the system may communicate in the distance more than 50km.