• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.117-120
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• 2003

PON (Passive Optical Network) is an emerging local subscriber access architecture that provides more bandwidth and services to subscriber than DSL (Digital Subscriber Line and HFC (Hybrid-Fiber Coaxial) network. A PON is a point-to-multipoint optical network with no active elements in the signals' path from source to destination. Advantages of using PON for a subscriber access network include large coverage area, reduced fiber deployment, multicast and broadcast capabilities, reduced cost of maintenance (due to devices being passive), and ease of upgrades to higher bit rate or additional wavelengths. PON uses WDM (Wavelength Division Multiplexing) technique that transmits the downstream and upstream data at each different wavelength. For transmitting the CATV (Community Antenna television) service through PON network, we give out additional wavelength. This study shows the available TPS (Triple play service) architecture using CATV overlay EPON (Ethernet PON) architecture and analyzes the effects of EPON-based CATV transmission by measuring the power loss fur each wavelength and the power range of the available analog wavelength and RF.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2A
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• pp.115-120
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• 2008

We propose a cooperative transmission scheme that uses Hurwitz-Radon space-time code for the relays which help the source to transmit signals to the destination, the full utilization here is that the destination utilizes the broadcast symbols from the source. We present the 2 transmit antennas case in detail because of its simplicity and high data rate. Analysis and simulations show that the proposed scheme achieves full diversity order of 3. The maximum likelihood receiver is also derived and the combining scheme is shown to be very simple.

• ETRI Journal
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• v.33 no.4
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• pp.629-632
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• 2011

This letter presents a hybrid conditional access system (CAS) for advanced terrestrial digital multimedia broadcasting (AT-DMB). The proposed architecture is characterized by its use of a unified CAS channel and various communication networks for CAS message transmissions. We implement a prototype CAS based on the hybrid architecture, which improves the CAS message transmission efficiency greatly compared to the existing T-DMB CAS standard and supports various AT-DMB interlayer services more easily and efficiently.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.8
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• pp.709-716
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• 2005

As a way to build more efficient and intelligent container cranes for todays hub ports, communication networks are used to interconnect numerous sensors, actuators, controllers, and operator switches and consoles that are spatially distributed over a crane. Various signals such as sensor values and operator's commands are digitized and broadcast on the network instead of using separate wiring cables. This not only makes the design and manufacturing of a crane more efficient, but also easier implementation of intelligent control algorithms. This paper presents the performance evaluation of CAN(Controller Area Network), TTP(Time Triggered Protocol) and Byteflight that can be used for cranes. Through discrete event simulation, several important quantitative performance factors such as the probability of a transmission failure, average system delay (data latency) and maximum system delay have been evaluated.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.2
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• pp.194-201
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• 2010

This paper discuss a performance evaluation of the synchronization algorithm for hybrid networks in industrial environments. The proposed algorithms minimizes synchronization errors which were caused from channel, Propagation, and frequency delays. The modified RBS and offset synchronization methods can be operated by adjustment parameters. The differential BP (Back-off Period) adjustment can synchronize the local time of each node with master node's time in hybrid networks. For the performance analysis, the data transmission time between the wired and wireless devices are investigated. The experimental results show the performance evaluations in terms of the polling service time and an average end-to-end delay.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.1
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• pp.29-34
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• 2010

In this study, we realized the broadband home gateway system of dual mode based upon EDR 2~3Mbps transmission speed and 300Mbps of 802.11n, In broadcasting and telecommunication convergence networks to deliver multimedia services, high-quality home. The bluetooth module is designed to use general low rate data speed service and the 802.11n module also is designed to use high rate speed service at various home network situation. The dual mode home gateway system, bluetooth and 802.l1n module, is well realized for many specification such as emission power, spurious power, impedance matching, frequency channel test.

• Annual Conference of KIPS
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• 2004.05a
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• pp.1493-1496
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• 2004

디지털 방송을 수신하는 셋탑박스가 IEEE1394 시리얼 버스를 사용하여 홈네트워크 상의 다른 위치에 존재하는 디스플레이 장치로 수신된 방송 컨텐츠를 재전송 하고 방송중인 채널의 변경이 가능하게 한다. 방송 스트림의 재전송은 IEEE1394 의 등시성 전송 방식을 이용하여 질적 열화가 없고 QoS가 보장되는 형태로 전송이 가능하도록 하며, 채널의 변경은 채널 변경 프로토콜을 이용하여 비동기 전송 방식을 통해 전달하여 데이터 전송의 명확성을 부여할 수 있다. 본 논문은 셋탑박스를 통해시청중인 방송의 채널 변경과 확인 등의 작업을 위한 프로토콜을 제공하여, 댁내에서 방송 및 MPEG2 TS 스트림의 재전송을 가능하게 하는 기법을 제안한다.

• Electronics and Telecommunications Trends
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• v.37 no.6
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• pp.64-73
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• 2022

This document describes the technologies related to internet protocol (IP)-based media production systems. As high-capacity, high-quality data transmission increases, broadcast production platforms are shifting to IP. The IP-based production system uses the network by sharing resources and is easy to control centrally. It also facilitates software-based cloud production. A cloud IP-based media production platform can work regardless of dedicated hardware and can easily collaborate. Associations and industrial groups have created common standards related to production, and manufacturers are developing solutions with their technologies based on their product competitiveness. This study investigates the open standard technologies used for IP-based media production and technology trends in the ProAV industry and describes the production in the cloud environment and cloud AI-based production technology trends.

• Annual Conference of KIPS
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• 2007.11a
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• pp.999-1002
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• 2007

널리 보급된 컴퓨터와 인터넷 그리고 모바일기기의 발달은 우리사회에 큰 변화를 주었다. 이는 이동성을 제공하면서 휴대 인터넷을 사용할 수 있는 서비스를 절실히 필요로 하게 되었고 그러한 요구에 부응하여 WiBro가 탄생하였다. 본 논문에서는 WiBro의 Downlink(DL)와 Uplink(UL)의 속도를 다양한 환경에서 현재 시판중인 WiBro 모뎀으로 성능을 평가해 보았고, 그 결과 WiBro에서 추구하는 DL:UL의 비율과 비슷하게 나옴을 확인하였다. 하지만 서비스 지역의 건물 내에서 WiBro의 서비스를 원활하게 받지 못하는 문제점을 발견하였고, 그 해결책으로 Fixed RS, Nomadic RS, 그리고 Mobile RS 3가지 방식을 제안하였다. 특히 건물의 경우는 Fixed RS(Relay Station)에서 Broadcast message 방식과 Wake-up 방식을 사용하도록 제안하였다.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.118-131
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• 2019

In order to provide 8K UHD contents of terrestrial broadcasting with a large capacity, the terrestrial broadcasting system has various problems such as limited bandwidth and so on. To solve these problems, UHD contents transmission technology has been actively studied, and an 8K UHD broadcasting system using terrestrial broadcasting network and communication network has been proposed. The proposed technique is to solve the limited bandwidth problem of terrestrial broadcasting network by segmenting 8K UHD contents and transmitting them to heterogeneous networks through hierarchical separation. Through the terrestrial broadcasting network, the base layer corresponding to FHD and the additional enhancement layer data for 4K UHD are transmitted, and the additional enhancement layer data corresponding to 8K UHD is transmitted through the communication network. When 8K UHD contents are provided in such a way, user can receive up to 4K UHD broadcasting by terrestrial channels, and also can receive up to 8K UHD additional communication networks. However, in order to transmit the 4K UHD contents within the allocated bit rate of the domestic terrestrial UHD broadcasting, the compression rate is increased, so a certain level of image deterioration occurs inevitably. Due to the nature of UHD contents, video quality should be considered as a top priority over other factors, so that video quality should be guaranteed even within a limited bit rate. This requires packet scheduling of content generators in the broadcasting system. Since the multiplexer sends out the packets received from the content generator in order, it is very important to make the transmission time and the transmission rate of the process from the content generator to the multiplexer constant and accurate. Therefore, we propose a variable transmission scheduler between the content generator and the multiplexer to guarantee the image quality of a certain level of UHD contents in this paper.