• Annual Conference of KIPS
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• 2007.05a
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• pp.1279-1282
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• 2007

무선 인터페이스 CDMA, WCDMA(HSDPA) 그리고 WiBro 는 대용량의 멀티미디어 컨텐츠를 제한된 무선자원에서 각 사용자에게 효율적으로 제공하기 위하여 Multicast 및 Broadcast 형태로 서비스를 제공하고 있으며, 이러한 서비스는 CDMA 에서는 BCMCS(Broadcast Multicast Service), WCDMA 에서는 MBMS(Multimedia Broadcast Multicast Service) 그리고 WiBro 에서는 MBS(Multicast Broadcast Service)라 불리고 있다. 본 논문에서는 각 서비스들의 DMB(Digital Multimedia Broadcasting)와 같은 방송형 서비스 및 다양한 멀티미디어 컨텐츠를 제공해 주기 위한 각 무선인터페이스의 Multicast 및 Broadcast 형태를 비교 및 분석하여 그에 따른 서비스의 확장성을 비교 분석하였다.

• Journal of Communications and Networks
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• v.18 no.3
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• pp.375-386
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• 2016

Most existing studies on broadcast services in orthogonal frequency division multiplexing (OFDM) systems have focused on how to allocate the transmission power to the subcarriers. However, because a broadcasting system must guarantee quality of service to all users, the performance of the broadcast service dominantly depends on the channel state of the user who has the lowest received signal-to-noise ratio among users. To reduce the effect of the worst user on the system performance, we propose a joint delivery scheme of unicast and broadcast transmissions in OFDM systems with broadcast and unicast best-effort users. In the proposed joint delivery scheme, the BS delivers the broadcast information using both the broadcast and unicast subcarriers at the same time in order to improve the performance of the broadcast service. The object of the proposed scheme is to minimize the outage probability of the broadcast service while maximizing the sum-rate of best-effort users. For the proposed joint delivery scheme, we develop an adaptive power and subcarrier allocation algorithm under the constraint of total transmission power. This paper shows that the optimal power allocation over each subcarrier in the proposed scheme has a multi-level water filling form. Because the power allocation and the subcarrier assignment problems should be jointly solved, we develop an iterative algorithm to find the optimal solution. Numerical results show that the proposed joint delivery scheme with adaptive power and subcarrier allocation outperforms the conventional scheme in terms of the outage probability of the broadcast service and the sum-rate of best-effort users.

• ETRI Journal
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• v.34 no.4
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• pp.492-502
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• 2012

We consider an overlaid broadcast service, where a spread spectrum (SS)-based broadcast signal is overlaid onto the existing terrestrial Digital Multimedia Broadcasting (T-DMB) band. The system is similar to the augmented data transmission in the ATSC DTV, for which it was investigated mostly in terms of link level performance, such as bit error rate. Our focus in this paper is on the system-level performances. More specifically, utilizing both a large scale path loss and a small scale fading channel model, the primary objective is to explore the tradeoff between the coverage and the achievable rate of the overlaid service and, finally, to determine the achievable rate in the overlaid service for marginal coverage reduction in the existing broadcast service. The analytical and simulation results show that an SS-based add-on service of 10 kbps to 20 kbps can co-exist with the T-DMB service while resulting in only a marginal degradation in T-DMB coverage (for example, less than one percent reduction).

• Journal of Broadcast Engineering
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• v.26 no.2
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• pp.197-207
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• 2021

The emergency alert broadcast service based on cellular communications is defined as CBS. However, the CBS just supports a limited text message, which might be unavailable to foreigners, who are unfamiliar with local characters. The CBS protocol relies on a broadcast mechanism. Such a broadcast technology exhibits that the number of outage users significantly increases under poor channel conditions. In this paper, we present a supplementary service technology for 5G CBS, which considerably enhances the accessibility of foreigners and illiterate persons, and the receiver performance. For the enhanced receiver performance, the proposed supplementary service approach effectively exploits the device-based geo-targeting capability that the 5G CBS can afford to offer.

• Broadcasting and Media Magazine
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• v.4 no.1
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• pp.43-53
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• 1999

Data Broadcast는 디지털TV에 PC가 가질 수 있는 멀티미디어 대화형 서비스 기술을 부여한 것으로 Interactive 디지털TV라고 할 수 있다. 대화형 서비스를 제공하기 위한 컨텐츠, 방송, 통신, 단말에 이르는 시스템에 대한 기술 규격을 정의하고 실제로 이를 구현하여 시험하는 것을 목적으로 하고 있다. 이 문서에서는 미국 규격을 중심으로 Data Broadcast Service관련 기술의 동향을 기술한다.

• Electronics and Telecommunications Trends
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• v.34 no.3
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• pp.23-33
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• 2019

Broadcast is evolving into media service aimed at user customization, personalization, and participation with high-quality broadcasting contents (4K/8K/AR/VR). A broadcast infrastructure is needed to engage with the competition for providing large-scaled media traffic process, platform performance for adaptive transcoding to diverse receivers, and intelligent service. Cloud service and virtualization in broadcast are becoming more valuable as the broadcasting environment changes and new high-level broadcasting services emerge. This document describes the examples of cloud and virtualization in the broadcast industry, and prospects the network virtualization of broadcast transmission infrastructure, especially terrestrial and cable networks.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.7
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• pp.32-38
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• 2009

In this paper, we consider the overlaid system of single frequency network broadcast service and cellular-based unicast data service. In general, broadcast service and unicast data service were considered as a separate services so that different frequency resources have been allocated for each. As the frequency resource get more expensive, however, there were some efforts to provide both the broadcast and unicast service over the same frequency resource by employing the so-called superposition coding. In fact, such an service overlay system has already been accepted as a standards in 3GPP long-term evolution (LTE). In this paper, we specifically investigate such overlay system within 3GPP framework and evaluate their performance in terms of BC coverage and UC data throughput.

• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.676-691
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• 2009

Recently mobile broadcast standards that have IP layer between transport layer and service layer such as DVB-IPDC, OMA-BCAST have been commercialized. Specially, IP abstract layer of OMA-BCAST makes it possible to interface diverse transport layers. Service guide, that is important for user interface, of these mobile broadcast standards has complex structure and heterogeneous schema. ESG schema is not interoperable, therefore terminals should have various implementations of service layer to support more than one service layer at a time. In this paper, not only for enabling interoperability of DVB-IPDC and OMA-BCAST but for supporting basic scenarios of mobile broadcast, simple ESG schema was developed. This new schema can be used as an independent ESG schema, especially for the integrated mobile broadcast middleware environment.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.383-394
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• 2023

Purpose : This study focuses on improvements in cell broadcast service(CBS) with consideration of socially vulnerable groups, and identifies service factors necessary for elderly people in particular. Method : Multiple regression analysis was applied to test overall satisfaction with cell broadcast service as the dependent variable and each of the service factors as the independent variable. Result : The results showed that fast delivery had the greatest effect on overall satisfaction with cell broadcast service in both groups, followed by the delivery of sufficient content for the elderly group and system quality for the non-elderly group. The results demonstrated that the elderly group cared more about information content, while the non-elderly group considered functions such as system quality and text message transmission criteria more important. Conclusion : Elderly people consider the delivery of sufficient information important as well as fast delivery, which suggests that it is necessary when sending cell broadcast service to give consideration to the characteristics of elderly people, as they tend to have weaker understanding and thinking abilities than the non-elderly.

• Journal of Broadcast Engineering
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• v.22 no.1
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• pp.107-117
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• 2017

Recently, IoT applications are being deployed in Smart TVs, and these IoT applications are using smart TVs as application platforms rather than broadcast platforms. With the advent of Hybrid broadcast technologies, now it becomes available to develop IoT applications which are coupled to the broadcast information. However, the existing IoT services are not suitable for Hybrid broadcast application since they are built on cloud and require various protocol implementations. In this paper, a Fog Computing-based architecture for hybrid broadcast application is proposed. Instead of accessing IoT services from hybrid broadcast app directly, the proposed architecture places Fog Applet Server between them and distribute loads of hybrid broadcast app to the Fog Applet. The proposed architecture is implemented as a service to control IoT device with hybrid application.