• Information and Communications Magazine
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• v.33 no.3
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• pp.3-10
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• 2016

최근 광대역 방식의 PPDR 시스템 도입 필요성이 증대함에 따라 관련 국제기구, 지역기구, 국가를 중심으로 광대역 PPDR 도입 방안을 검토했으며, 현재 일부 국가들은 망 구축을 시작하고 있는 상황이다. 국제기구인 ITU를 중심으로 요구사항, 주파수, 기술방식 등에 관한 연구가 진행되었으며, 유럽, 이시아-태평양 지역기구도 지역기구 입장에서 관련 사항 연구를 추진했다. 최근 WRC-15회의가 끝남에 따라 주파수는 700MHz대역과 800MHz대역이 국제적 공통주파수로 결정되었고, 기술방식은 대부분의 국가에서 PS-LTE가 채택되었거나 우선적으로 검토되고 있다. 망 구축 방식은 국가별 상황에 따라 상용망, 혼합망 등이 검토, 추진되고 있다. PS-LTE 구축 사례로서 미국은FirstNet이 2012년에 설립되어 현재 RFP발행을 위한 마지막 단계에 있으며, 영국은 사업자 선정을 앞두고 있어 2017년부터 망 구축이 추진될 것으로 전망된다, 호주는 800MHz대역에서 LTE방식으로 활용할 계획이나 구체적인 주파수나 망 구축방식은 정해지지 않은 상태이다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.141-144
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• 2011

최근 무선통신의 발전과 스마트 폰 사용자의 급격한 증가로 인하여 멀티미디어 콘텐츠에 대한 사용이 증가되면서 트래픽 량과 네트워크 속도 증가에 대한 요구가 급속히 증대되고 있다. 이를 위해 LTE, LTE-Advanced, Mobile WiMAX 등 차세대 이동통신 플랫폼 및 연관 기술들이 많이 제안되고 있다. 이에 따라 차세대 이동 통신 프로토콜 개발 단계부터 안정화 단계까지 프로토콜 검증 및 분석을 위한 프로토콜 분석기가 필요하게 되었다. 본 논문에서는 LTE-Advanced 망에서 L3 프로토콜들을 분석할 수 있는 분석기를 제안한다. 제안하는 분석기는 연동 메시지를 XML 메타데이터로 기술하여 분석 시 활용하며, ASN.1 인코딩된 연동 메시지나 바이너리 인코딩된 메시지를 디코딩하여 분석할 수 있는 기법을 적용하였다. 자체 설계된 LTE-Advanced 망과의 연동 테스트를 통해 본 시스템을 검증하였다.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.30-40
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• 2011

Recently, together with the development of wireless communication technologies and the wide use of smart phones, the demand of the next generation mobile communication has been increased. To construct the next generation mobile communication platform efficiently for a short period from protocol development phase to protocol stability phase, an protocol analyzer is required to verify and analyze the protocol. In this paper, we propose the protocol analyzer of LTE network which is the leader of the next generation mobile communication platforms. The protocol analyzer is a software based agent-server architecture and uses XML metadata which defines intercommunication messages to analyze the protocol of the next generation mobile communications. We can analysis the encoding messages applied to LTE network using the loading of the decoding library. We verify the superiority of the proposed analyzer through an integrated test with LTE network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.2
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• pp.358-365
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• 2017

In order for developing countries to design and deploy Long Term Evolution (LTE) network in a cost-efficient manner, the differentiated way of technological design and deployment methods are necessary as compared to those for advanced countries. This paper focused on Radio Access Network (RAN) design methodology for developing countries that consists of major part of the network cost. To verify the effectiveness of the suggested design methodology, a Korean telecom company A's actual design experience in an African developing country was examined.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.81-89
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• 2014

The heterogeneous LTE-Advanced networks comprising a macrocell and femtocells can provide an efficient solution not only to extend macrocell coverage but also to deal with packet traffics increasing explosively within macrocells. Efficient resource management schemes are necessary to maintain the QoS requirements of versatile multimedia applications in LTE-Advanced networks because their service-continuity may be defected by some delay and information loss. In this paper, we propose a resource allocation method for the heterogeneous LTE-Advancedl networks overlaid with femtocells. Performances are analyzed by simulation.

• Journal of Advanced Navigation Technology
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• v.20 no.6
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• pp.595-603
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• 2016

In the Republic of Korea, the LTE-based public safety (PS-LTE) network is being built for the 700 MHz frequency band. However, the same bands are also assigned to the LTE-based high-speed railway (LTE-R) network. Therefore, it is essential to utilize the co-channel interference management schemes for the coexistence of two LTE networks in order to increase the system throughput and to reduce the user outage probability. In this paper, we focus on the downlink (DL) system for the coexistence of PS-LTE and LTE-R networks by considering non radio access network (RAN) sharing and LTE-R RAN sharing by PS-LTE users (UEs) to analyze the UE throughput. Moreover, we also utilize the cooperative communications schemes, such as coordinated multipoint (CoMP) for the coexistence of PS-LTE and LTE-R networks in order to reduce the UE outage probability. We categorize the coexistence of PS-LTE and LTE-R networks into four different scenarios, and evaluate the performance of each scenario by the important performance indexes, such as UE average throughput and UE outage probability.

• Convergence Security Journal
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• v.16 no.4
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• pp.17-24
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• 2016

Many companies and organizations are building a mobile office environment using the LTE network, the national disaster network and Air Force LTE network are built for public safety and national defense. However the recent threats on information security have been evolving from information leakage to DDoS attacks to neutralize the service. Especially, the type of device such as Smart phones, smart pad, tablet PC, and the numbers are growing exponentially and As performance of mobile device and speed of line develop rapidly, DDoS attacks in the mobile environment is becoming a threat. So far, universal countermeasure to DDoS attacks has been interception the network and server step, Yet problem regarding DDoS attack traffic on mobile network and expenditure of network resources still remains. Therefore, this paper analyzes the traffic type distributed in the private mobile network such as the National Disaster Network, and Air Force LTE network in order to preemptively detect DDoS attacks on terminal step. However, as direct analysis on traffic distributed in the National Disaster Network, and Air Force LTE network is restricted, transmission traffics in Minecraft and uploading video file upload which exhibit similar traffic information are analyzed in time series, thereby verifing its effectiveness through establishment of DDoS attacks standard in mobile network and application that detects and protects DDoS attacks

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2A
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• pp.174-185
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• 2010

A seamless handover between the 3G LTE and legacy 3G system is required for the smooth deployment of the 3G LTE system which is the next generation cellular network system. Especially on voice call handover, the service interruption time is very sensitive for user's satisfaction and therefore, a seamless voice call handover scheme is necessarily required. However, handover between the 3G LTE and the 3G CS system is hard to be achieved due to the lack of interface between two systems and the restriction of radio resource. In this paper, a new network entity called SCSE is proposed and inter-working between the 3G LTE and the 3G CS systems is enabled. Also contributed to the feature of the SCSE, the handover procedure is simplified and the service interruption time is minimized as a consequence. The evaluation result shows that the proposed SCSE scheme exclusively meets the service interruption time requirement which is smaller than 300 ms.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.373-375
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• 2018

초고속해상무선통신망 전국연안 구축사업에 앞서 해양수산부는 2017년에 강릉항, 부산항, 목포항에 시험망을 구축하여 해상 LTE망에 대한 다양한 시험을 실시하였다. 한국정보통신기술협회(이하 'TTA')는 한국형 e-Navigation 사업의 협동연구기관 자격으로 초고속해상 무선통신망 품질검증 업무를 수행하고 있다. 본 고에서는 2017년에 구축된 시험망에 대한 TTA 품질 측정 결과를 소개하고 전국연안 확산에 앞서 고려되어야 할 주요 시사점을 제시한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.31-36
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• 2020

The LTE-R system is a system consisting of a packet network that provides all IP-based services. Continuous failures related to the platform safety gate and subsequent safety accidents related to passengers and safety gate workers continue. The secondary damage caused by the failure of the platform safety door and the related human life damage have emerged as a major social issue.. By linking the beacon system to the Long Term Evoluton-Railway (LTE-R) network, an LTE-based railway wireless network currently in operation or being installed, it precisely locates trains and provides standardized fault alerts to train crews. When entering into the station, ultimately we will decelerate the train and reduce the accidents of metropolitabn railroad traffic by securing safe driving.