• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.8
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• pp.59-66
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• 2009

Recently, as the expectation about the IPTV (Internet Protocol TV) service quality is rapidly increased by the development of the national high-speed internet and TPS (the Triple Play Service : data + image + audio) service Therefore, the enactment of the national quality standards about the IPTV service quality guaranteeing the real time video quality of a subscriber and the international standards are hastily needed. This paper built a test bed with the network domain and the subscriber set-top box domain including the headend area and commercial network characteristic in order to test in the environment which is similar to the characteristic of the service business network. And by using the constructed environment, the characteristics required for SLA(service Level Agreement) of the IPTV service are presented as the quality test according to the service environment change.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.1
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• pp.139-146
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• 2017

The ISDB-T(Integrated Service Digital Broadcasting Terrestrial) can be used in the multipath and impulsive noise, also it provide good performance over mobile reception environment since it use the OFDM(Orthogonal Frequency Division Multiplexing) based transmission technology and time interleaving technology. One segment and full segment are divided according to the number of the assigned segment. And one-segment broadcasting receiver can design and implement without high levels of technology than the full-segment broadcasting receiver using 64QAM(64 Quadrature Amplitude Modulation) since it uses QPSK(Quadrature Phase Shift Keying) modulation/demodulation. However, it has a constraint in the display size and resolution due to data-rate limits. In this paper, we design and implementation of full-segment ISDB-T receiver module which support HD resolution for set-top box, digital TV, navigation. In experimental results, the implemented full-segment ISDB-T receiver module was satisfactory for all of the desired functions.

• Journal of Broadcast Engineering
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• v.9 no.1
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• pp.74-82
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• 2004

In digital broadcasting, applications are computer programs executed by the set-top box(TV receiver) , and synchronized applications are those that perform tasks at the specified moments in the underlying video. This paper describes important concepts, standards, and skills needed to implement synchronized applications and explains how to integrate them to implement these applications. This Paper assumes the European data broadcasting standard, DVB-MHP. In DVB-MHP, scheduled stream events are recommended as a means of synchronizing applications with video streams. In this method, the application receives each stream event, and executes the action associated with the stream event at the time specified in the stream event. Commercially available stream generators, i.e., multiplexers, do not generate transport streams that support scheduled stream events. So we used a stream generator implemented in our lab. We implemented a synchronized application where the actions triggered by stream events are to display graphic images. We found that our synchronized application processes scheduled stream events successfully. In our experimentation, the stream events were synchronized with the video and the deviation from the intended time was within 240 ㎳, which is a tolerance for synchronization skew between graphic images and video.

• The KIPS Transactions:PartC
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• v.17C no.5
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• pp.407-414
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• 2010

A condition access system (CAS) refers to a hardware-based system that allows only authenticated users to have access to contents. The CAS has many disadvantages found in that in the replacement of multiple service operator (MSO) a set-top box should be also changed and the smart-card often causes malfunction. To deal with the problems, exchangeable CAS (XCAS) was developed in 2009. However the standards or evaluation schemes for XCAS are absent. Existing evaluation schemes are not appropriate for evaluating XCAS due to the evaluation standard, the evaluation cost and efficiencies. Therefore, a specific scheme that can evaluate the security and suitability of exchangeable conditional access systems has been requested. In this paper, we propose an appropriate evaluation scheme for XCAS. The evaluation scheme includes an evaluation purpose and four components to evaluate the evaluation target, the evaluation process, the evaluation subject, and the evaluation cost involved.

• Journal of Korea Multimedia Society
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• v.13 no.12
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• pp.1767-1777
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• 2010

In digital TV broadcasting, such as terrestrial, cable, satellite, and IPTV, the head-end of digital TV broadcasting has a more complicated transmission structure than that of analog TV broadcasting. Furthermore, digital TV broadcasting has a feature that supports multiplex models, such as Multiple Program Transport Stream (MPTS). Therefore, the purpose of our work was to design and examine a more efficient new system of emergency alert message transmission to support the digital TV broadcasting environments. Digital TV broadcasting is the IP generation or RF transmission of 8-VSB, QAM, and QPSK modulated through a multiplexer or re-multiplexer multiplexed stream as a MPEG-2 Transport Stream after content encoding. The new system proposed in this paper transmits an emergency alert message without scrambling after replacing the PID and payload of the -packet with the message prototype in the TS stream from the multiplexer. If we need to transmit an emergency alert message under digital TV broadcasting services, then the receiver first checks the PID of each packet in the TS stream for the emergency alert message. Next, if a packet is determined to be an emergency alert message, then the set-top box displays the message on the TV screen using its function of On Screen Display, or the PC based software displays the message on the monitor screen using its function of overlay with user interface if the packet is found to be an emergency alert message. We have designed an emergency alert message protocol and a system model. By experiments and analysis of the system, we concluded that the system achieved efficiency and the ability to send and receive emergency alert messages using the system under different digital TV broadcasting service environments.

• Journal of KIISE:Software and Applications
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• v.36 no.9
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• pp.697-705
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• 2009

A GUI automated test can be divided into two areas. The first one is a regression test automation and the second one is an automated test. The former includes generating test cases manually and executing them automatically but the latter includes both generating test cases and executing them automatically. Costs of a software test are increasing more and more. Many companies are searching for a test automation method but most used things are limited to regression test automation. So, when testing at first, there should be test cases which are drawn up by a human. This paper explains to make test cases based on a source code and execute them automatically. In this paper, the study proceeds with a digital television set-top box application and explains to test without any effort of human. Of course, this study is far from a realization to industries. But this paper has a contribution at reducing more human efforts than the previous regression test automation and showing that later, fully automated test can be possible.

• The KIPS Transactions:PartC
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• v.18C no.1
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• pp.23-30
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• 2011

Recently internet protocol television (IPTV) service is becoming a typical emerging service enabled on broadband networks. Through the Internet which cannot support quality of service (QoS) beyond best-effort (BE) policy, how to manage and maintain its service quality is an important and essential issue for successful deployment and settlement of IPTV service. In particular, the current measurement scheme that mostly depends on specific equipments should be replaced with one that supports realtime and constant measurement achieved on a user's own will. Therefore, this paper proposes a scheme so-called 'user centric realtime measurement' of IPTV service. The developed software, which is installed in a set-top box (STB) at a user's premise, measures and reports the quality of IPTV service in realtime. In order to verify the performance and accuracy of the developed software, a number of tests are performed comparing to the measurement values from two major measurement equipments. The result of the tests shows that the measurement by the implemented software is significantly reliable.

• The KIPS Transactions:PartC
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• v.13C no.6 s.109
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• pp.717-724
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• 2006

This paper describes the design and implementation of architecture for convergence of home network services and data broadcasting services based on UMB and ACAP middleware; the one is used for interoperability of home networked devices, and the other for data broadcasting services. The proposed architecture provides TV-centric user interface capable of managing home network services and data broadcasting services together using a remote controller and TV sets TV applying Java TV Xlet interface and HAVi user interface for home network services like data broadcasting services. Besides, we define the service proxy for accessing home network services in a set-top box and the service broker for providing data related to home network services in a home server. Finally, the application manager in ACAP middleware manages the lifecycle of home network services through service events from the service proxy to the application manager.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.746-753
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• 2003

In this paper, we propose an efficient algorithm for non-streaming synchronized data processing based on ATSC-DASE in terrestrial digital data broadcasting services. Non-streaming synchronized data is encapsulated in DSM-CC sections with PTS(presentation time stamp) values associated with A/V and it is transmitted in a form of MPEG-2 TS(transport stream). At the receiver, the transmitted A/V data are processed by PC based set-top box(STB) in real-time, and the transmitted non-streaming synchronized data is also stored at the STB and is displayed at right time by the proposed algorithm. To verity the proper operation of the proposed algorithm, we make a scenario for non-streaming synchronized data by XML, and finally we are able to display it properly by using declarative application(DA) browser.

• Journal of Broadcast Engineering
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• v.11 no.4 s.33
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• pp.483-494
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• 2006

In this paper, we propose a novel program specific information structure(PSI) in MPEG-2 system for a three-dimensional broadcasting system while guaranteeing compatibility with the conventional digital broadcasting system. The proposed PSI structure including a descriptor of contents type, 2D or 3D, provides service providers with a function of combining 2D and 3D contents freely. However the descriptor is ignored in the conventional digital broadcasting set-top box. With the proposed PSI structure, we designed and implemented a three-dimensional broadcasting system. The proposed system has 2D or 3D display mode for providing user's preference in a three-dimensional broadcasting environment.