• Review of KIISC
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• v.29 no.5
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• pp.21-30
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• 2019

우리나라는 세계 최초로 초고속 초연결 초저지연의 5G 이동통신 상용화에 성공하였다. 비록 아직은 4G LTE 코어망과 연계하여 5G 서비스를 제공하고 있지만, 향후 5G 코어망이 구축된 이후에는 완전한 5G 네트워크를 통해 5G 융합서비스가 본격화될 전망이다. 그러나, 우리 실생활과 밀접한 새로운 미래 혁신 서비스에 대한 기대와 열망 때문에 5G 네트워크 환경이 갖고 있는 잠재적 보안위협이나 취약점을 간과해서는 안된다. 보다 고도화되고 지능화되는 사이버 공격에 대응하기 위해 위협 대응전략 또한 고도화되어야 한다. 본 논문에서는 5G 보안 기술을 이해하기 위해 3GPP의 5G 보안 기술규격인 TS 33.501을 바탕으로 5G 보안의 근간을 이루는 구조적 특징과 4G 대비 주요 개선사항을 중심으로 소개한다.

• 정보화사회
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• s.188
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• pp.18-25
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• 2007

삼성전자가 주최하는'삼성 4G포럼'이 지난 8월 27일과 28일 이틀 간 서울 신라호텔에서 개최됐다. 삼성 4G포럼은 2005년 모바일 와이맥스(와이브로) 기술을 세계 최초로 선보였고, 지난해에는 세계 유수의 경쟁업체들을 크게 앞서는 4G 기술을 선보임으로써 차세대 통신기술의 발전상을 꿰뚫어볼 수 있는 행사로 자리를 잡고 있다. 올해 행사에서는 삼성전자가 주도하는 모바일 와이맥스뿐만 아니라, 3GPP LTE(Long Term Evolution), 3GPP2 UMB(Ultra Mobile Broadband) 등 ITU가 4G의 유력 후보 기술로 꼽은 3대 통신기술이 한자리에서 소개되고 기술개발 및 표준화 동향을 공유하는 자리가 마련돼 더욱 눈길을 끌었다. 4세대 이동통신, 즉'4G'란 이동 중 100Mbps, 정지 상태에서는 1Gbps급 속도를 제공하는 무선 통신기술로, 지난 2005년 10월 ITU(국제전기통신연합)이'IMT-어드밴스트(advanced)'를 공식 명칭으로 결정한 바 있다. 하지만 현재의 3G와는 완전히 다른 새로운 세대의 통신 기술이라는 점을 강조하기 위해 여전히 4G라는 용어가 널리 쓰이고 있다.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.249-250
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• 2008

In the field of mobile communications, load balancing between 3GPP LTE and other networks is expected to be an important topic from the perspective of current technical development. The load balancing technique includes the definition of functions and structures needed to incooperate 3G LTE E-Node B and base-stations designed for heterogeneous networks. The major goal attained from this paper is to ensure an algorithm for the mechanism of load balancing and to achieve a technical leading for the next generation mobile network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.900-902
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• 2013

In this paper, we propose the CPW antenna with three folded lines for miniaturization. This antenna is consisted of a meander-line on the middle position for LTE band and two folded lines. As widths of three lines are gradually changed to broaden bandwidth, antenna is designed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5458-5464
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• 2012

In LTE-Advanced that different networks coexist, it is considered that it is actually difficult to provide service continuity with a procedural and static control method applied to the existing voice service. This research suggests a resource management framework to support the service continuity effectively based on QoS support. In other words, as context information of mobile terminal and base station changes, set-up of related functions such as ISHO, cell selection, source allocation, load control, and QoS mapping is adapted; each function fits into the change, exchanges the process of reorganization, and interacts; these actions go toward to satisfy service continuity. For this aim, the sequence diagram between the function modules for supporting four kind of ISHO is described and then a scenario for ISHO is considered.

• Journal of KIISE
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• v.42 no.6
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• pp.723-733
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• 2015

The OTT service that provides multimedia video has spread over the Internet for terminals with a variety of resolutions. The terminals are in communication via a networks such as 3G, LTE, VDSL, ADSL. The service of the network has been increased for a variety of terminals giving rise to the need for a new way of encoding multimedia is increasing. SVC is an encoding technique optimized for OTT services. We proposed an efficient multimedia management system for the SVC encoded multimedia data. The I/O trace was generated using a zipf distribution, and were comparatively evaluated for performance with the existing system.

• ETRI Journal
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• v.44 no.3
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• pp.361-378
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• 2022

In 5G, the required target for interruption time during a handover (HO) is 0 ms. However, when a handover failure (HOF) occurs, the interruption time increases significantly to more than hundreds of milliseconds. Therefore, to fulfill the requirement in as many scenarios as possible, we need to minimize HOF rate as close to zero as possible. 3GPP has recently introduced conditional HO (CHO) to improve mobility robustness. In this study, we propose "ZEro handover failure with Unforced and automatic time-to-execute Scaling" (ZEUS) algorithm to optimize HO parameters easily in the CHO. Analysis and simulation results demonstrate that ZEUS can achieve a zero HOF rate without increasing the ping-pong rate. These two metrics are typically used to assess an HO algorithm because there is a tradeoff between them. With the introduction of the CHO, which solves the tradeoff, only these two metrics are insufficient anymore. Therefore, to evaluate the optimality of an HO algorithm, we define a new integrated HO performance metric, mobility-aware average effective spectral efficiency (MASE). The simulation results show that ZEUS provides higher MASE than LTE and other CHO variants.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.3
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• pp.469-478
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• 2022

This paper contains the results of developing smart devices and applications to monitor the load power of the industrial manufacturing machine and evaluate its performance. The smart devices in this paper are divided into two functionalities, which are collecting load power along with operating environment data of industrial manufacturing machines and transmitting the data to servers. Load power data collected from the smart devices are uploaded to MariaDB inside the Amazon Web Service (AWS) server. Using the RESTFul API, the uploaded power data can be retrieved and shown on the web and mobile application in the form of a graph to provide monitoring capability. To evaluate the performance of the developed system, the response time from MariaDB to web and mobile applications was measured. The results is ranging from 0.0256 to 0.0545 seconds in a 4G (LTE) network environment and from 0.6126 to 1.2978 seconds in a 3G network environment, which is considered a satisfactory result.

• Electronics and Telecommunications Trends
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• v.32 no.2
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• pp.62-70
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• 2017

5G 네트워크 기술은 4G LTE 이동 통신 기술의 후속 기술로서, ITU-R, ITU-T, NGMN, 3GPP 등의 표준화 그룹을 중심으로 고성능, 저지연, 고가용성 등의 특성을 가지는 새로운 Clean-slate 형태의 이동 통신 시스템 및 네트워크 구조를 설계 중이다. 특히 다양한 5G 융합 서비스를 효율적으로 제공하기 위해 서비스 및 네트워크 자원의 독립성 및 유연성을 지향하는 네트워크 슬라이싱을 적용하고, ETSI NFV 네트워크 기능 가상화 기술을 포함하는 네트워크 관리 구조를 도입하고자 한다. 본고에서는 5G 네트워크 슬라이싱 기술 및 5G 네트워크 관리 기술의 개념 및 요구사항을 분석하고, 이에 대해 3GPP SA WG2 및 SA WG5에서 진행 중인 표준화 현황을 소개한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.126-129
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• 2015

Device-to-device (D2D) communications, a subset of Proximity-based Services that enables direct communication between LTE network subscribers, is gaining popularity. It is well underway to be adopted in cellular communication systems for pedestrian and connected-vehicles alike. In this paper, we briefly present our model of an Evolved Packet Core Network-assisted device discovery simulator and show the applicability of Proximity-based Services for Vehicular Ad-hoc Networks. Through the performance evaluation based on the developed simulation environment, it is shown that in case when users gather in the same vicinity, as in public transportation, LTE network data can be efficiently offloaded and multicasted through Wi-Fi for e.g. delivering traffic-related information and for the benefit of infotainment service consumers.