• Information and Communications Magazine
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• v.30 no.8
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• pp.11-19
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• 2013

본고에서는 M2M/IoT 통신의 실현을 위한 무선 통신망 기술을 알아보고 IoT 통신을 위한 요구사항과 이를 해결하기 위한 연구 동향을 살펴본다. 특히, 많은 수의 IoT 디바이스가 싱크 노드를 이용하여 IP 망에 접속하는 Wireless Sensor network(WSN)에서의 문제와, LTE-A와 같은 cellular 망을 이용하여 접속하는 IoT 서비스로 나누어 논의한다. WSN관점에서는 에너지에 대한 제약이 심한 환경을 고려하여 발생할 수 문제점들을 분류하고 이에 대한 다양한 해결책을 제시하며, Cellular 망에서는 현재의 LTE-A 망에 많은 수의 IoT 디바이스가 연결될 경우 발생할 수 있는 문제점들을 논하고 기존의 통신에 영향을 최소화 하며 IoT 서비스를 공존할 수 있는 연구 동향을 논한다.

• Journal of Satellite, Information and Communications
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• v.11 no.4
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• pp.68-73
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• 2016

This paper describes the prototyping of CDMA bi - directional group search system using USRP and LTE. This paper describes the results of RF signal generation and transmission by implementing a spread spectrum signaling system, which is a new standard of COSPAS SARSAT, using a bi-directional search structure system using commercial LTE network and USRP.

• Journal of IKEEE
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• v.25 no.1
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• pp.109-115
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• 2021

In this paper, the fine dust detecting terminal which can transmit data in real time was developed. The terminal used a wide spreading LTE network and was powered by solarcell and battery for easy installation and independent operation, because it did not need the wired power grid or wired communication network. The data showed the possibility of forecasting fine dust changes by analyzing with the data from public meteorologic data. The developed terminal will be helpful for predicting and analyse fine dust's more precise flow and effect on environment with an easy installation on any places.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.827-829
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• 2015

This paper presents process of the UE obtains the cell system information in order to achieve communication with the LTE network on the LTE. This paper deals with the process of extracting MIB(Master Information Block) cell system information in LTE. To study the 3GPP LTE standard spec series 36.200 and 36.300, the simulation is implemented to extract the MIB in MATLAB program. The simulation process is divided into three parts. It consisted of a part that extracts the PSS, SSS and MIB. Called a cell search process for detecting the PSS and SSS, the process is to be done in order to extract only the cell system information. The simulation program is verified based on the signal captured from the real Air.

• Information and Communications Magazine
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• v.33 no.3
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• pp.66-73
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• 2016

본고에서는 미래창조과학부 공공통합망 주파수 (700MHz대역)를 사용하는 철도통합 무선통신망 (LTE-R)의 호남고속철도 익산~정읍간 시험선 구축을 통한 실용화 계획과 함께 국가 철도망 적용을 위한 노선별, 지역별 중장기 구축 계획과 최초로 사업화를 준비중인 원주-강릉 복선전철 시범사업에 대한 내용을 소개한다.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.451-455
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• 2014

In LTE (Long Term Evolution)/LTE-A (Long Term Evolution-Advanced) networks, hierarchical macro/femto-cell structure is adopted to enhance system capacity. Such a femto-cell is deployed as a Closed Subscriber Group (CSG) eNB. However, the inbound handover to CSG cell experiences longer delay than normal handover because it spends more time detecting the associated CSG cells due to its sparse deployment. Most of all the legacy UEs (User Equipments) have been implemented without considering the inbound CSG handover. Accordingly, they may not meet the performance requirements on the cell discovery described in the LTE/LTE-A standards. Therefore, in this paper, the performance of the CSG femto-cell detection is evaluated using computer simulation. The evaluation results will provide a basis to tackle the latency problem of inbound CSG handover.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.9
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• pp.1398-1405
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• 2015

Domestic railway communication in Korea has been introduced for mutual communications among control center, operation staffs, and maintenance staffs. It has been mainly used as railway disaster and safety functions from VHF and UHF from 1980’s and TRS-Astro and TRS-Tetra from the 2000’s. Recently for urban railways communications, 18GHz and 2.4GHz ranges have been utilized for image transmissions and control command communications, respectively. This paper analyzes technical development of LTE-R, LTE communication for Railways, that has been designed as a single integrated railway wireless network in order to merge the current various communication systems. In this paper, we present the details of the examination of the LTE-R test-bed using 2.6GHz test frequency in Daebul test line through CW test and optimization test.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.805-814
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• 2013

According to the shut-down of Analog TV service on 30th. December, 2012, UHF Digital Dividend Band (698~806MHz) could be used for Mobile service such as LTE(Long Term Evolution). In the condition that this band is allocated for LTE service, Interference evaluation between LTE and adjacent DTV service was carried out, using LTE-A system-level simulator which was developed for simulation of IMT-Advanced technology. If LTE service be commercialized in this band, this study proposes the coexistence condition through the interference evaluation such as the effects not only to DTV receiver from LTE terminal but also to LTE base station from DTV transmitter. It is expected that the coexistence condition by these studies will be applied to network algorism for IMT-Advanced system in this band.

• Journal of the Korean Society for Railway
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• v.16 no.6
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• pp.519-527
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• 2013

Mobile radio technologies have evolved in the railway industry offering seamless connectivity and various functionalities to improve railway service. Recently, advanced mobile communication technologies have enabled a new level of railway customer services with more efficient railway operation. Since the LTE mobile communication technology offers many benefits and better performance for new railway services, it is considered to be a strong candidate for the future railway mobile telecommunication. However, communication networks in the railway sector are critical for secure operation and have stringent requirements for reliability and safety. In this paper, we explain the requirements for the future railway mobile telecommunication. The LTE, which would be the future railway mobile technology, is analyzed against these requirements. We also introduce the current state of standardization for the future railway mobile telecommunication and its implementation plan.

• TTA Journal
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• s.139
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• pp.100-103
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• 2012