• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.345-351
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• 2010

It has been growing interests that convergence services of broadcasting and telecommunication services such as DMB 2.0 and Mobile IPTV etc. Unicast type is difficult to service broadcasting due to limits of capacity and poor receiving environments, WiBro supports broadcast service with MBS. MBS is transmission method that base stations belong to same the MBS zone transmit the all users who request broadcasting service. Terminals are received resources from all base station in the MBS zone and SINR can be improved because of macro diversity. If terminals are located at edge of the MBS zone, complement algorithm are needed beacause received SINR is very low. In this paper, MIMO STBC, Relay and FFR are introduced to improve the throughputs using high MCS. The basic simulation environment is assumed to be SISO. Transparent relay and FFR applicable on MBS are divided by SISO and MIMO STBC environment and evaluate the performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.802-812
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• 2008

This paper proposes QoS Model which has tested and analyzed the capabilities of provisioning multimedia service in high speed Internet environment. We have tested quality measurement test for VoIP/MoIP, VoD, IPTV services and analyzed the level of QoS and QoS degradation by constructing test laboratory consisted of 46 subscribers which provided by 3 telecom operators. Besides, We propose QoS Model to apply for BcN application based on analysis result and prove proposed model by constructing test lab in KOREN environment. It is expected that telecom will use this results as a valuable information to construct All-IP network based on NGN(NGN:Next Generation Network).This paper proposes QoS Model which has tested and analyzed the capabilities of provisioning multimedia service in high speed Internet environment. It is expected that telecom will use this results as a valuable information to construct All-IP network based on NGN.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.275-280
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• 2013

With rapidly growing mobile wireless services, the existing copper-based mobile backhaul technologies suffer from reaching the capacity limits. PON technologies is drawing attention as a key solution to replace the existing mobile backhaul technologies due to not only providing innovative network capacity but also cost-effective maintenance caused by the bandwidth gain from optical fibers. With a PON-based mobile backhaul, broadband wireless multimedia services such as a video conference and IPTV can be seamlessly provided. In this paper, we first introduce overview of the PON-based mobile backhaul technology. For a example of practical integration, three types of EPON-WiMAX integrated architectures are proposed and comparatively analyzed in term of costs and network performance. Then, applicable plan and anticipated effects are presented when applying network coding on the PON-based mobile backhaul to improve the performance of delivering multicast traffic.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.503-516
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• 2010

In this paper, we propose the converged profile and authentication scheme for supporting converged media services of broadcasting & communications convergence in fixed mobile convergence networks. The proposed scheme supports the management of access, service, mobility and IPTV profiles on subscriber and a function of open API(Application Program Interface) for providing the subscriber profile for the third party service provider with the PUSH/PULL method. The open API is based on a web service and a REST(Representational State Transfer) and provides various services for the third party service provider with ease. In addition, the proposed scheme supports a function of SSO(Single Sign-on). After user succeeded in establishing an access connection, user can sustain the same authentication state with this function although connected access network is changed or IMS(IP Multimedia Subsystem) service network is attached. We evaluate and analyze the performance of the proposed scheme through the implementation of CUPS(Converged User Profile Server) system test-bed.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.137-144
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• 2007

Advances in networking technology digital media, and codecs have made it possible for the Internet evolves into a Broadband convergence Network (BcN) and provides various services including Voice over Internet Protocol (VoIP) and IPTV over their high-speed IP networks. In order for the Internet to make a profit as traditional Public Switched Telephone Network (PSTN), it must provide high qualify VoIP services. Therefore, real time qualify measurement framework is the most important requisite to provide VoIP service. For this, IETF (Internet Engineering Task Force) defined RTCP-Extended Reports (RTCP-XR) that extend RTCP (Real-Time Transport Protocol Control Protocol). However, procedure and method tot actually VoIP qualify measurement did not recommended nothing but defined item to measure voice quality. Our objective in this paper is to describes a practical measuring framework for end-to-end QoS of switched voice packet in an IP environment. It includes concepts as well as step-by-step procedures for measuring packetized voice streams. It also proposes new formats that extend RTCP-XR's concept.

• Journal of KIISE:Information Networking
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• v.36 no.3
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• pp.191-197
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• 2009

One of popular applications in the Internet is the multimedia streaming services such as IPTV or You Tube in which supporting quality of service (QoS) is an important issue. One of widely adopted rate control scheme is TCP-friendly rate control (TFRC) which shows comparable performance with TCP in term of throughput and lower variation of throughput over time. On the other hand, devices with multiple interfaces are emerging in the market. However, it has not proposed to exploit multiple interfaces simultaneously for multimedia streaming services with TFRC. In this paper, we propose a multimedia streaming algorithm with TFRC which exploits multiple interfaces to guarantee the quality of service. We show that the proposed scheme shows better performance than those with a single interface in terms of throughput and communication costs.

• Journal of Information Technology Services
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• v.11 no.3
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• pp.161-175
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• 2012

A novel concept of ICT based service, which is called N-device service, is proposed and implemented in the form of N-device smart education services. The N-device services are different from the existing N-screen services in terms of the number of devices a user is using for a specific service at the same time. A N-device service consists of several smart devices which are different in size, software and hardware platform, mobility, manufacturer and the like by fully utilizing the characteristic of each device. The major and unique features of N-device services are analyzed and depicted in a strict way. Those are shared role for each device, service by configurable device, one sensor multiple use, real-time data sharing, role shifting and new market creation. It is turned out that the N-device service is more human centric compared with existing ICT based services and can give richer digital experience to users because non-existent services become possible with the new concept. However, there exist several barriers to be implemented and commercialized in the real world. Those include high development cost and time, small market and different application platforms of devices. These barriers can be overcome by technical advances and cooperation between relevant parties. The smart education is very prominent area, in which the novel concept can be applied with high priority because Korean government announced its plan to boost up new educational services with big budget and these are acceptable by enthusiastic Korean parents and students. That's why the N-device service is implemented in the education area, which is called as "livessam(live teacher)," with four smart devices, IPTV, tablet PC, PC and smart phone. By providing both detailed service scenario and techniques, we shows that the novel education service is technically feasible and acceptable by teachers and students.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.4
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• pp.229-234
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• 2008

The 'Anytime, Anywhere' services have been the biggest topic in the recent digital broadcasting research area. The related applications for the Anytime and Anywhere Services are as follows: the personalized broadcasting based on the PVR (Personal Video Recorder) for the Anytime Services, and the DMB (Digital Multimedia Broadcasting), the mobile devices supporting the wireless network and the Second TV and so on for the anywhere services. The personalized broadcasting has been researched on the one of the killer applications in the various broadcasting environment - the ground wave broadcasting, the satellite broadcasting, IPTV and CATV broadcasting suchlike. The applied contents of the personalized broadcasting have advanced from the main contents for the broadcasting to the interstitial contents like advertisements and coupons, the personalized interstitial broadcasting needs to develop the technology about the generation, storing and management of the interstitial metadata. but, the personalized broadcasting has the limitation that the TV environment is somewhat difficult to support the personalized broadcasting individually, because all family usually share the main TV at home. The Second TV is possible to solve the environmental limitation. This paper designs and develops the static set top box at home, the Second TV and their multimedia streaming techniques for the personalized broadcasting of the contents including the interstitial contents.

• Asia Marketing Journal
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• v.11 no.3
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• pp.91-124
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• 2009

With the intensity of competition and the standardization of technical attributes in telecommunications service market increasing, differentiated activity and customer experience in service encounter is regarded as an important means for creating customer value, however, there is a dearth of good literature examining what MOT activity is composed of according to consumption chain, and how service quality of MOT has influenced customer performance. Especially there exist various services across different phase of Product life cycle(PLC) in household telecommunication service market, customer requirement for MOT might depend on whether its phase is introduction-growth stage or maturity-decline stage, the empirical study is completely lacking. This study classified household telecommunication services into two types by PLC, VOIP and IPTV as Introduction-growth stage services, Internet and PSTN as maturity-decline stage service, and investigated whether there exists a gap between service types in how consumer have experienced MOT, what they consider as important and the relative importance of quality dimension how service quality of MOT has influence on consumer performance. The empirical result from 858 participants shows that there is a difference in consumer experience and requirements across different phases of the PLC, tangibles and assurance are regarded as the most important service quality factors which have a positive influence on customer performance (consumer satisfaction, repurchase intention and word of mouth) at the introduction-growth stage, whereas, reliability, empathy and interactivity are at the maturity-decline stage. Finally, managerial implication is made, limitation is clarified and a direction for further studies is suggested.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.1
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• pp.39-59
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• 2009

Game theory is adapted to a variety of domains such as economics, biology, engineering, political science, computer science, and philosophy in order to analyze economic behaviors. This research is an application of game theory to wireless communication. In particular, in terms of bargaining game we dealt with a multimedia resource allocation problem in wireless communication, which is rapidly spreading such as Wibro, WCDML, IPTV, etc. The algorithm is assumed to allocate multimedia resources to users who can choose and access differentiated media services. For this purpose, 3 utility function of users is devised to reflect quality of service (QoS) and price. We illustrated experimental results with synthesis data which were made to mimic real multimedia data, and analyzed differentiated service providing and the effect of the utility function.