• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2117-2123
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• 2014

To cope with the explosive growth of traffic which is considered as one of the most biggest threat to current mobile communication systems, various solutions such as small cell and device-to-device communication have been exploited. Directional transmission in which transmission power of base station is focused onto the direction where the mobile station is located, can be used to increase throughput of the system. In this work, we develop a system-level simulator for cellular mobile communication systems using directional transmission and adaptive interference estimation scheme for directional transmission has been proposed. By using the developed simulator, the performance of cellular mobile communication systems with directional transmission is examined. Moreover, it is shown that the overall throughput of cellular system can be improved by utilizing directional transmission.

• Journal of Information Technology and Architecture
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• v.10 no.2
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• pp.197-209
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• 2013

This study analyzes the nature of consumers and smart phones as well as its limitations that domestic mobile communication companies confront. According to the analysis results, emerging technologies such as 5G communication, pervasive computing, augmented reality, and big data seem to have significant effect on the ICT ecosystem in the near future. Based on the results, this study suggests four counterstrategies for domestic mobile communication companies: big data strategy, preparation of things acting as a main communication agent, new service platform development, and 'total life care service provider' strategy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1780-1786
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• 2005

The phase error generated in the transmission system affects the performance of digital transmission signal. The phase error are generated by random phase noise and tracking phase error due to denier phenomenon. In the mobile satellite communication system that generates the doppler frequency, which is a system with a movement, the proper system phase noise spectrum should be designed based on analyses for phase noise and static phase error effects. Based on the analyses of the doppler frequency and the phase error for bilateral satellite communication system providing an asynchronous service, the phase noise spectrums for the mobile satellite communication are designed in this paper. Also, the available transmission services under the less doppler effect are proposed and the proper signal source units for a required transmission system can be designed under the proposed system phase noise spectrum.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.841-843
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• 2014

Mobile communication systems such as WCDMA, Wibro, LTE, etc are being developed to meet the explosively increasing demands for wireless data. These communication systems are using the power at all times. In general a base station has all of the communication systems mentioned above in order to provide a more convenient service to a number of users. The demands for wireless data are changed according to time and location. If the mobile communication systems are selectively operated according to the demand for wireless data then the consumed power can be saved. This paper describes the design and implementation of the load management system which controls the supplied power to the mobile communication infrastructures depending on the demand of wireless data.

• The Korean Journal of Emergency Medical Services
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• v.23 no.1
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• pp.125-134
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• 2019

Purpose: The aim of this study was to evaluate the usefulness of video communication with medical staff located at a remote location, through a communication application connected to a long term evolution (LTE) mobile communication network in a moving ambulance. Methods: In this study, we recruited patients who were transferred by mobile intensive care unit ambulance from one hospital to another. In the moving ambulance, the information of the patient was transferred to a physician using the application in real time. Recorded video files were evaluated by emergency physicians with experience in video direct medical control. Results: A total of 18 patients were evaluated, and the average score was 5.9 out of a possible 9. It was expected that applying the use of the technology to actual clinical sites would enable the sites to provide assistance. Conclusion: In this study, we confirmed the possibility of benefiting from the clinical field when using the video-audio communication application which is connected to the remote location in real time through the current LTE mobile communication network in the ambulance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.89-95
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• 2008

The introduction of wireless information technology gives rise to new mobile services in all kinds of areas of out daily life. Mobile healthcare system is a production of composite ICT (Information and Communication Technology) which focused on signal sensing, processing, and communication in wireless environment. The mobile and wireless revolution promises not only expanded access to patient health information, but also improved patient care. In this paper, we describe a surrogate host based mobile healthcare information system which utilized Grid computing for real-time ECG signal processing. The surrogate host provides seamless interface between mobile device and Medical Grid portal. The security extension of GSI (Grid Security Infrastructure) allows mobile users to access Grid portal in a secure and convenient manner. The presented system architecture can be used as a secure enterprise mobile healthcare system for hospital physicians.

• Journal of Internet Computing and Services
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• v.7 no.3
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• pp.61-69
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• 2006

Data synchronization between data stored in mobile communication terminals and a central server is one of essential tasks for efficient mobile communication environments. Since, however, manufacturers of mobile terminals have their proprietary data synchronization mechanisms, data interoperability can hardly be achieved. Therefore, SyncML data synchronization mechanism in mobile communication environments was proposed as an open standard by OMA(Open Mobile Alliance). In this paper, a SyncML-based data synchronization gateway is designed and implemented which can process ActiveSync data also. In other words, by constructing a combined data synchronization gateway which can transform ActiveSync data into SyncML data, data interoperability between mobile terminals which use two different data synchronization mechanisms can be achieved, In addition, mobile communication experiments between ActiveSync-based terminals and a SyncML-based central server show that the data synchronization gateway constructed in this paper, works correctly.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.562-570
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• 2011

In this paper, a distributed mobile relay power control (DMRPC) scheme for maximizing individual cell throughput is proposed for mobile relay aided multi-cell orthogonal frequency division multiplexing (OFDM)-time division duplex (TDD) system. In the system with DMRPC, the power levels of relay's are controlled by individual cell without cell cooperation and signalling overhead. It is demonstrated by numerical simulation that DMRPC provides the better cell throughput performance than either the full power relay aided system or conventional system without relay does. Moreover, it is also shown that relay aided systems with DMRPC, and the conventional system have almost identical cell edge throughput, while full power relay aided systems show worse performance in cell edge throughput.

• Agribusiness and Information Management
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• v.6 no.2
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• pp.24-31
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• 2014

This paper is a study on what kind of effect non-verbal communication in mobil electronic commerce has on purchase intention and visual attention. For this purpose, the screen of mobile shopping mall produced arbitrarily was exposed to the experimental group and the control group. The experimental group was exposed to the screen of mobile shopping mall that expressed non-verbal communication making use of cinemagraph images and the control group was exposed to the screen of mobile shopping mall based on still images. For the study, survey research and experimental research were conducted simultaneously. Data of survey research were analyzed by MANOVA and t-test, and by using eye-tracker experimental research recorded the duration of time that the subjects stared images. The results of experiment show that in non-verbal communication the experimental group that saw cinemagraph images recorded shorter average staring time than the control group that saw ordinary images, and the cinemagraph had statistically significant effect on visual attention as well. And it was analyzed that non-verbal communication had significant effect on the purchase intention of the experimental group, but had no effect on the purchase intention of the control group. The results can be interpreted that the people who saw cinemagraphs in mobile shopping environment had spent shorter time in seeing products than the people who saw ordinary images, but still the former came to have purchase intention on the products. The results of the present study can be useful for marketers who try to sell agrifood in mobile environment.

• Journal of Advanced Navigation Technology
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• v.13 no.4
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• pp.490-502
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• 2009

This monograph details the development of communication UAV(Unmanned Aerial Vehicle) in combined modems of HSDPA with Wibro by using two kinds of mobile network. In order to apply mobile network which is currently serviced to a UAV, it is necessary to solve some problems : insurance of wide coverage based on the range of the UAV, electrical transmission of extensive image data for UAV for watching and scouting, security of stable communication environment is related to network traffic. This paper proposes those difficulties to be solved by application of correspondence system to mobile network. The proposed system consists of two parts; HSDPA part and Wibro part. The use of those can not only secure wide range of coverage but also transmit huge data. Furthermore, through utilizing them along with two kinds of mobile network, stable communication environment can be built up. All of these effects can be confirmed by experimentations and simulations.