• Journal of Korea Multimedia Society
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• v.7 no.4
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• pp.518-531
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• 2004

This paper discusses a testbed architecture for implementing scalable service differentiation in the Internet. The differentiated services (DiffServ) testbed architecture is based on a model in which a bandwidth broker (BB) can control network resources, and the ALTQ can reserve resources in a router to guarantee a Quality of Service (QoS) for incoming traffic to the testbed. The reservation and releasemessage for the ALTQ is contingent upon a decision message in the BE. The BB has all the information in advance, which is required for a decision message, in the form of PIB. A signaling protocol between the BB and the routers is the COPS protocol proposed at the IETF. In terms of service differentiation, a user should make an SLA in advance, and reserve required bandwidth through an RAR procedure. The SLA and RAR message between a user and the BB has implemented with the COPS extension which was used between a router and the BB. We evaluates the service differentiation for the video streaming in that the EF class traffic shows superb performance than the BE class traffic where is a network congestion. We also present the differentiated service showing a better packet receiving rate, low packet loss, and low delay for the EF class video service.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.152-164
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• 2012

DMB provides various kinds of data services such as BWS and TPEG service in addition to audio and video services. But recently the necessity of new business models creating profit has been on the rise due to the saturation of DMB receiver market and break-down of market barrier between mobile IPTV and DMB services. This paper introduces DMB filecasting service technology, which can be expected a new profit-creative business model. The purpose of DMB filecasting service is to transmit non-real time multimedia contents based on DMB AF format to the users through DMB channels. It makes possible to consume DMB contents with any DMB-installed device anytime, anywhere and share them with others. Also DMB filecasting service makes consumption and request of DMB contents possible to be extented to a variety of networks as well as DMB channels. The paper explains the standardization status of DMB filecasting service and various DMB filecasting service scenarios. And also it proposes a signalling methode, a transmission and reception protocol and a receiver structure using DMB broadcasting program guide information.

• Journal of Practical Engineering Education
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• v.7 no.1
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• pp.31-37
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• 2015

Terrestrial digital multimedia broadcasting (TDMB) is a method of bringing multimedia images, radio, internet, and television to portable devices through terrestrial digital radio transmissions. TDMB related educations being carried out in colleges are focusing on developing firmware which enables users to choose a wanted service. TDMB transmission frame is made up of synchronization channel (SC), fast information channel (FIC), and main service channel (MSC). Services such as video, audio and date are transmitted in the form of subchannel in the MSC. FIC carries information related to each services and subchannels. This paper presents a TDMB frame analysis simulator for analyzing and displaying FIC data on PC. TDMB frame analysis simulator contains functions such as controlling TDMB receiver through USB, establishing the frequency, bringing FIC to PC, displaying ensemble ID and levels, and displaying informations related to services and subchannels. In addition to that, this simulator has a function of being able to store FIC date and subchannel data. This simulator being developed with C++ is expected to be used to view those data visually so that it helps students to understand the TDMB system better and bring about the educational motivation.

• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.436-449
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• 2016

This paper compares the transport overhead of MMT (MPEG Media Transport) with that of MPEG-2 TS (Transport Stream). MPEG-2 TS is globally used in multiplexing compressed audio and video data in digital broadcast industry, including areas of DTV (Digital Television), IPTV (Internet Protocol Television), and DMB (Digital Multimedia Broadcasting). It was the early 1990s when MPEG-2 TS standard was established. After more than two decades of years since its first establishment, many parts of MPEG-2 TS turned out to be inappropriate to today's broadcast and communication environment. Given the situations, in 2014 MPEG (ISO/IEC JTC 1 SC 29/WG 11) standardized MMT as the next-generation multimedia transport standard hopefully that can replace MPEG-2 TS. In this paper, with assumptions of broadcast service scenarios we applied both MMT and MPEG-2 TS to each scenario and we calculated their transport overheads. We used a software program that counts the transport overhead, which was developed in our laboratory for this paper. And we conducted a comparative analysis based on the calculated result of transport overhead.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.410-426
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• 2003

MPEG-21 defines a digital item as an atomic unit lot creation, delivery and consumption in order to provide an integrated multimedia framework in networked environments. It is expected that MPEG-21 standardization makes it Possible for users to universally access user's preferred contents in their own way they want. In order to achieve this goal, MPEG-21 has standardized the specifications for the Digital Item Declaration (DID). Digital Identification (DII), Rights Expression Language (REL), Right Data Dictionary (RDD) and Digital Item Adaptation (DIA), and is standardizing the specifications for the Digital Item Processing (DIP), Persistent Association Technology (PAT) and Intellectual Property Management and Protection (IPMP) tot transparent and secured usage of multimedia. In this paper, we design an MPEG-21 terminal architecture based one the MPEG-21 standard with DID, DIA and DIP, and implement with the MPEG-21 terminal. We make a video summarization service scenario in order to validate ow proposed MPEG-21 terminal for the feasibility to of DID, DIA and DIP. Then we present a series of experimental results that digital items are processed as a specific form after adaptation fit for the characteristics of MPEG-21 terminal and are consumed with interoperability based on a PC and a PDA platform. It is believed that this paper has n important significance in the sense that we, for the first time, implement an MPEG-21 terminal which allows for a video summarization service application in an interoperable way for digital item adaptation and processing nth experimental results.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.85-91
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• 2007

Satellite Digital Multimedia Broadcasting (S-DMB) is the digital convergence service of broadcasting and communication for mobility and portability. Broadcasting service of S-DMB can be taken by the mobile phone or vehicle terminals anytime and anywhere. S-DMB system is currently providing 11 video channels and 26 audio channels. As the demand of multimedia service is recently increasing, S-DMB system needs high quality and new contents service. Therefore we need to make efficient S-DMB with more channel ability and high transmission quality. In this paper, we propose new S-DMB system that can be applied to powerful channel coding scheme and hierarchical 8-PSK(8-Phase Shift Keying) modulation with Backwards Compatibility modes that simultaneously can support both current and new system. And we analyze the performance of current S-DMB system and verify a possibility of advanced S-DMB through computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11A
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• pp.1106-1112
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• 2007

As a demand for high speed uplink packet services increases, the WCDMA enhanced uplink, also known as high speed uplink packet access (HSUPA), has been specified in release 6 by 3GPP. This HSUPA will provide various types of multimedia services, such as real-time video streaming, gaming, VoIP, and FTP. Generally, the performance of HSUPA is dominated by scheduling policy. Therefore, it is required to design a scheduling algorithm considering the traffic characteristics to provide QoS guaranteed services in various traffic environments. In this paper, we propose a scheduling algorithm considering the traffic characteristics to guarantee QoS in a mixed traffic environment. Finally, the performance of the proposed scheduling algorithm is evaluated in terms of average packet delay, packet delay jitter, and system throughput using a system level simulator.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.51-59
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• 2015

The advanced T-DMB is the digital broadcasting technique upgrading the T-DMB which has low effective data rate compared with other things. Since it applies the hierarchical modulation, it has maximally twice as much the effective data rate of a T-DMB, so it can provides the video service of high quality and many stations more than a T-DMB. Therefore, the study for DAB service on the AT-DMB environment will be advantageous better than the previous studies for it on the T-DMB environment. So, this paper proposes the method of the channel allocation for DAB service on the Advance T-DMB system environment and presents the results of the interference analysis in order to verify that.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1526-1537
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• 1998

The split-screen function on the multipoint control unit(MCU) which is usually using processing method based on pixel domain has many problems for manipulating the video signal in real-time. Although the researches and the developements to cope ith such problems are processing, these have too complex architecture to implement and are limited to method for H.261 video signal. In this paper, we propose a new mechanism for split-screen that can actually apply to ISO/IEC MPEG video standard. The new method that is proposed in this paper do the processes in complete compression domain, thus it is suitable for the application of real-time multipoint multimedia communication service. By simple interpreting and manipulating the MPEG video element stream, the split-screen functional module can be implemented easily and the result of the procedures does not accompany image degradation at all. Finally, the complexity of implementation, the aspect for processing delay and the loss of image quality as compared to that resulting in the case of applying the previous split-screen method has been investigated. And it is confirmed that the proposed mechanism has a significant advantage as a split-screen method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2004.11a
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• pp.271-276
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• 2004

디지털방송이 시작되면서 고품질의 A/V(비디오/오디오)프로그램과 다양한 멀티미디어 컨텐츠를 제공하는 데이터방송을 처리하기 위한 수신 장치의 비중이 커지고 있다 이와 관련하여 데이터방송 환경에서 새로운 기술과 서비스가 등장할 때마다 이를 수용할 수 있는 소프트웨어를 탑재한 새로운 수신 장치가 필요하다. 일반적으로 한번 가정 내에 보급된 디지털 수신 장치의 소프트웨어 업그레이드가 용이하지 않기 때문에, 방송을 통해 이를 실현한다. 본 논문은 TV 셋탑박스 (STB) 내에 상주하는 middleware native application software 를 방송으로 다운받아 수정하는 기능을 지닌 STB 의 구현에 대해서 기술한다. 소프트웨어 업데이트 시스템은 소프트웨어를 포함하는 데이터 카루셀 스트림을 다운받아 파싱하는 다운로더, 추출된 소프트웨어를 설치하는 업데이트 로더, 그리고 예치상황이 발생하면 셋탑박스가 새로 부팅될 때, 로그 파일을 이용하여 소프트웨어를 옛날 상태의 회복시켜주는 리커버러 (recoverer)로 구성되어 있다. 다운로더는 지상파 디지털 방송 규격인 ATSC 규약에 맞게 구현하고, ATSC용 STB환경에서 테스트하고 있다.