• Title/Summary/Keyword: Mobile Communications

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Mobile Communications System and Its Development Vision (이동통신 시스템과 개발 비전(I))

  • 조규심
    • Journal of the Korean Professional Engineers Association
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    • v.31 no.1
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    • pp.9-16
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    • 1998
  • For the flow facing high1y informationized age, there is a flow from fixed communications connecting fixed places such as offices and homes to mobile communications connecting mobile objets such as automobiles, ships and aircraft. This flow has added to diversifying communications Including data and images. While the axed mode is diversifying information media by digitalization of communications network and computers, the mobile mode has brought higher sophistication of communication modes by a higher degree of electric wave utilization. The following descriptions outlines the mobile communication which is utilizing the electric wave phenomena. In sequence the following items are described: a brief history of mobile communications, the technical object and various kinds of services, propagation of electric wave signal.

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Mobile Communications System and It's Development Vision(II) (이동통신 시스템과 개발 비전(II))

  • 조규심
    • Journal of the Korean Professional Engineers Association
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    • v.31 no.2
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    • pp.65-72
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    • 1998
  • For the flow facing highly informationized age, there Is a flow from fixed communications connecting fixed places such as offices and homes to mobile communications connecting mobile objets such as automobiles, ships and aircraft. This flow has added to diversifying communications including data and images. While the fixed mode Is diversifying information media by digitalization of communications network and computers, the mobile mode has brought higher sophistication of communication modes by a higher degree of electric wave utilization. The following descriptions outlines the mobile communication which Is utilizing the electric wave phenomena. In sequence the following items are described: a brief history of mobile communications, the technical object and various kinds of services, propagation of electric wave signal.

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An Analysis of the 4G Mobile Communications Technology Development Strategy in Korea (4세대이동통신 기술개발전략 분석)

  • 노일수;엄기용;유영신;이병남
    • Proceedings of the Technology Innovation Conference
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    • 2002.06a
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    • pp.257-268
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    • 2002
  • Korean mobile communications industry has been a main locomotive of the drastic development of Korean IT industry and became one of core industries in national economy. To secure strong competitiveness of mobile communications industry, smooth cooperation should be reconsidered among government, universities, research institutions, and private companies. Future mobile communications technology will be evolved from IMT-2000 to system upgrade, 3.5G and 4G. And the goals of technology development are provision of mobile multimedia services based on better mobility and higher data speed rates. Therefore, Korea's technology development strategies of mobile communications should be focused on intensifying bondage of international cooperation, strengthening standardization activities, and enhancing core technology development capability to secure IPR.

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Demonstration of Mobile Fronthaul Test Bed Based on RoF Technology Supporting Two Frequency Assignments and 2 × 2 MIMO Antennas

  • Cho, Seung-Hyun;Han, Changyo;Chung, Hwan Seok;Lee, Jong Hyun
    • ETRI Journal
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    • v.37 no.6
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    • pp.1055-1064
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    • 2015
  • We demonstrate a next-generation high-capacity mobile fronthaul based on radio over fiber (RoF) technology, which links between a digital unit and a radio unit supporting two frequency assignments and $2{\times}2$ multiple input, multiple output antennas. To confirm the technical feasibility of a mobile fronthaul, we experimentally investigate its down- and uplink end-to-end performances including the optical and radio frequency (RF) signal path. Frequency-dependent performance deviations, error vector magnitude variations, overall system performance variations caused by optical to electrical conversion, and intermediate frequency to RF conversions are examined. Experimental verifications on multiple LTE uplink signals are performed for the first time. We also demonstrate several commercial mobile Internet services, YouTube video streaming, and file transfers using off-the-shelf mobile devices, through a mobile fronthaul based on RoF.

Converged Mobile Cellular Networks and Wireless Sensor Networks for Machine-to-Machine Communications

  • Shan, Lianhai;Li, Zhenhong;Hu, Honglin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.1
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    • pp.147-161
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    • 2012
  • In recent years, machine-to-machine (M2M) communications are under rapid development to meet the fast-increasing requirements of multi-type wireless services and applications. In order to satisfy M2M communications requirements, heterogeneous networks convergence appears in many areas, i.e., mobile cellular networks (MCNs) and wireless sensor networks (WSNs) are evolving from heterogeneous to converged. In this paper, we introduce the system architecture and application requirement for converged MCN and WSN, where mobile terminals in MCN are acting as both sensor nodes and gateways for WSN. And then, we discuss the joint optimization of converged networks for M2M communications. Finally, we discuss the technical challenges in the converged process of MCN and WSN.

A Study on Implementation of Roaming Function in Digital Mobile Communications System using a Client-Server Model (클라이언트-서버 모델을 사용한 디지틀 이동통신 시스템의 로우밍 기능 구현에 관한 연구)

  • 임선배;박진우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.12
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    • pp.1371-1379
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    • 1992
  • In this paper, we describe the general concept of digital mobile communications system and present a client-server model for the implementation of roaming function, which is on of the most important functions in digital mobile communications system. And finally we also describe our simulation test and analysis for the presented client-server model.

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Implementation of Mobile Internet E-mail & Chatting Program using WIPI Platform

  • Hwang, Byung-Kon
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2005.11a
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    • pp.7-12
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    • 2005
  • In this paper, we implemented an e-mail and chat program (client) for communication between mobile devices and PCs based on WIPI a South Korea's open wireless platform form developing device and content independent software to break from the way of developing contents that is dependent on different wireless platforms to each mobile communications company. While traditional e-mail and chat programs are written for PC-to-PC communication, we develop them for mobile-to-PC and mobile-to-mobile communications, and we expect to see various mobile contents in the future.

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Laws & Regulations concerning Base-Stations for Next-generation Mobile Communication Networks

  • Noh, Sun-Kuk
    • Journal of information and communication convergence engineering
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    • v.2 no.4
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    • pp.209-213
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    • 2004
  • With the commercialization of CDMA 2000-1x late in 2000, a high-speed wireless Internet, based on a mobile communication networks, appeared in Korea. This will develop into the next-generation of mobile communications(4G) in the future and the new cell layout will be required the cellular configuration of 4G. We would need the legislation with respect to base-stations and to building the mobile communication networks, as well as the optimization of mobile communication systems. In this study, in order to provide 4G, I examined and analyzed that the current laws & regulations related to licensing and operating a mobile communication base-stations in KOREA.

An Efficient Proxy-Signcryption Scheme for Mobile Communications (이동통신 환경에 적합한 효율적인 Proxy-Signcryption 방식)

  • 김동우;박지환
    • Journal of Korea Multimedia Society
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    • v.6 no.3
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    • pp.518-526
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    • 2003
  • According to the development of mobile communications, the future mobile communication systems are expected to provide high quality multimedia service to users. Therefore, many technical factors we needed in these systems. Especially the confidentiality and the security would be obtained through the introduction of the security for mobile communications. In this paper, we propose an efficient Proxy-Signcryption scheme, which can be performed digital signature and encryption by using the proxy agent who has more computational power under mobile communications environment. The proposed scheme provides non-repudiation and prevents creating illegal signature by the origin and proxy agent in a phase of proxy signature processing. This scheme also keeps the confidentiality and the security in mobile communication by means of confirming the signature by right receiver.

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