• Journal of IKEEE
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• v.13 no.3
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• pp.7-17
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• 2009

WiMedia UWB technology is a fully distributed data communication technology developed for the application demanding a high data transmission rate in the wireless PAN area. In general, devices can send data either by reserving time slots or by using prioritized CSMA/CA. If the PCA protocol of prioritized CSMA/CA is used, they are suffered congestion as the number of devices increases. In this paper, we propose a Deterministic Access Protocol(DAP) in WiMedia WPANs. A DAP is a method to transmit data in the non-reserved DRP period without competition as each device informs the beacon order information in the beacon period and the queue information. In addition, the problem that the devices with a lower beacon slot number have more transmission opportunities is addressed by introducing the reference point. Simulation results are given to demonstrate that a DAP can improve the throughput and reduce the packet loss rate.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.89-96
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• 2010

In this paper, "a wireless camera image transmission system" is aimed for the free camera shooting in the indoor and outdoor environments. Currently in broadcasting program production environments, because the cable connections between TV OB VAN(outside broadcasting VAN) and EFP camera or ENG camera have many obstacles and limits of distances, it is very unconvienent for the free camera shooting. Therefore in this paper, wireless image transmission device and receiving device in DVB-T broadcasting are developed. In this paper, analog composite image signal output camera, image signal compression MPEG-2 system and COFDM mage transmission system are produced and experimented. The results for the image and transmission system had good QoS values and from this results, it is possible to apply TV program productions and wireless CCTV device industries.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.123-126
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• 2006

멀티미디어 홈 네트워크 환경을 위해서는 A/V(Audio/Video)데이터의 실시간 전송에 유리한 IEEE1394 네트워크와 이동성을 편리하게 지원하고, 홈 외부로의 전송에 적합한 이더넷의 상호 연동 서비스가 필요하다. 따라서 본 논문은 가정내의 IEEE1394 기반 A/V 장치에서 홈 내부 및 외부의 이더넷 기반 모바일 장치로 멀티미디어 데이터를 전송하고, 인터넷의 멀티미디어 데이터를 IEEE1394 기반 A/V 장치로 전송하는 홈 게이트웨이의 구조를 제안한다. 멀티미디어 데이터의 실시간 전송을 위해 DV to MPEG4 트랜스코더를 DV, MPEG4 코덱을 통해 구현하였고, IEEE1394 네트워크와 이더넷 사이의 멀티미디어 데이터 전송 및 제어를 위해 스트리밍 서버와 MPEG4 코덱을 내장한 클라이언트, 그리고 IEC61883 규격을 이용한 IEEE1394 장치 제어 모듈을 제작하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.2
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• pp.38-44
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• 2013

In this paper, we designed and implemented a mobile video transmission device with 1080i resolution and 30fps frame rate using wireless multi-access technologies. The video acquisition delay time of 16us and jitter of 21ms for this equipment were obtained, respectively. The device is designed to access various communication networks. In order to evaluate the performance of its video transmission capability, a server and monitoring viewer are implemented. In the performance test using LTE network, 211ms delay time was obtained at 3Mbps transmission. Rendering of 1fps frame rate at the 265kbps transmission was confirmed for the transmission test using Inmarsat network.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.3
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• pp.54-61
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• 2002

A remote image transmission apparatus combines robot technology and image transmission there is safe problem or place that a person can not go. Recently, control apparatus that use wire and RF between web server and robot for remote control are developed. But there is problem that must install internet line and communication distance. Transmission distance problem call solve when using the equipment of RF, but price of RF router is problem that is very high cost. In this paper, we developed remote control system using the CDMA cellular phone communication network that can control image transmission and image transmission apparatus to solve these problem. Developed system could solve defects of methods that use existent RF and internet. And could transmit the most suitable image and voice under limited condition include current communication network.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.456-457
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• 2008

본 논문은 계통보호 전송장치(PITR)의 교체기준 설정에 관한 연구이다. 본 논문에서는 PITR의 최적 교체주기를 찾기 위하여 다양한 시도를 하였다. 고장데이터로 고장 분포함수를 이용한 이론적인 수명주기 활용, 현장 전문가 의견, 제작사 전문가 경험 등을 종합하여 PITR의 최적 교체주기를 제안하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.11
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• pp.1052-1057
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• 2007

A highly reliable Video Transmission System (VTS) was developed in order to obtain both video and digital data simultaneously in the real time flight test situation of a flying vehicle. The VTS integrates GPS data, digital telemetry data and video signals into a compact digital data package which is compressed and processed by an MPEG-2 Encoder and a DVB-S modulator respectively. The DVB-S modulator is composed of a specially devised Forward Error Correction processor and base band QPSK modulator. The designed VTS was verified and proved for its required functioning and performance through separate flight tests using an airplane and missiles.

• Journal of Aerospace System Engineering
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• v.13 no.2
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• pp.10-18
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• 2019

In this paper, we present the results of a developed LTE/Wi-Fi-based video transmission system which can be applied in small unmanned aerial vehicles of 25kg or less. The developed video transmission system comprised of airborne datalink terminal, ground datalink terminal, and used LTE and Wi-Fi wireless data communication technologies to transmit videos of resolution higher than HD (720p/30fps, 1080p/30fps) taken by small UAV. The airborne device is designed to efficiently transmit real-time streaming video through the incorporation of H.264 video processing board. Ground tests and evaluation indicated the possibility of the developed system to transmit real-time videos from close distance in regards to non-line-of-sight area.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.44-45
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• 2017

선박의 안전운항을 위해, 선내 센서데이터 수집장치를 설치하여 선박의 항해/기관 데이터를 수집하고, 수집된 데이터를 이용하여 긴급상황레벨 결정 및 위기대응 가이던스를 제공한다. 선박에서 수집된 데이터는 LTE-M 망을 이용하여 육상으로 전송하는 시스템을 개발한다. 선데 데이터 수집장치는 IEC 61162-1 표준으로 항해통신 장비들의 데이터를 수집하고, 기관부 데이터는 Moubus로 데이터를 수집한다. 수집된 데이터는 UDP로 육상 송수신 장치로 데이터를 전송한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.117-124
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• 2017

A Smart Grid is a system that can efficiently use energy by exchanging real-time information in both directions between a consumer and a power supplier using ICT technology on an existing power network. DR(Demand response) is an arrangement in which electricity users can sell the electricity they save to the electricity market when the price of electricity is high or the power system is crisis. In this study, we developed a power meter data transmission device and power IT system that measure the demand information in real-time using a smart meter and transmit it to a cloud server. The power meter data transmission device developed in this study uses alight sensor connected to a Raspberry Pi 3 to measure the number of blinking lamps on the KEPCO meter per unit of power, in order to provide reliable data without any measurement errors with respect to the KEPCO power data. The power measurement data transmission device uses the standard communication protocol, OpenADR 2.0b. The measured data is transmitted to the power IT system, which consists of the VEN, VTN, and calculation program, via the LTE WiFi communication network and stored in its MySQL DB. The developed power measurement data transmission device issues a power supply instruction and performs a peak reduction DR when a power system crisis occurs. The developed power meter data transmission device has the advantage of allowing the user to adjust it every 1 minute, where as the existing smart metering time is fixed at once every 15 minutes.