• Journal of Communications and Networks
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• v.14 no.3
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• pp.319-335
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• 2012

In this study, we design an applicable model enabling internet protocol television (IPTV) service providers to use a virtual network (VN) for IPTV service delivery. The model addresses the guaranteed service delivery, cost effectiveness, flexible control, and scalable network infrastructure limitations of backbone or IP overlay-based content networks. There are two major challenges involved in this research: i) The design of an efficient, cost effective, and reliable virtual network topology (VNT) for IPTV service delivery and the handling of a VN allocation failure by infrastructure providers (InPs) and ii) the proper approach to reduce the cost of VNT recontruction and reallocation caused by VNT allocation failure. Therefore, in this study, we design a more reliable virtual network topology for solving a single virtual node, virtual link, or video server failure. We develop a novel optimization objective and an efficient VN construction algorithm for building the proposed topology. In addition, we address the VN allocation failure problem by proposing VNT decomposition and reconstruction algorithms. Various simulations are conducted to verify the effectiveness of the proposed VNT, as well as that of the associated construction, decomposition, and reconstruction algorithms in terms of reliability and efficiency. The simulation results are compared with the findings of existing works, and an improvement in performance is observed.

• The Journal of the Korea Contents Association
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• v.10 no.12
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• pp.51-58
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• 2010

In the environment of instant messengers, the recognition of human emotions and its automated representation with personalized 3D character animations facilitate the use of affectivity in the machine-based communication, which will contribute to enhanced communication. This paper describes an emotional messenger system developed for the automated recognition and expression of emotions for IPTVs (Internet Protocol televisions). Aiming for efficient delivery of users' emotions, we propose emotion estimation that assesses the affective contents of given textual messages, character animation that supports both 3D rendering and video playback, and smart phone-based input method. Demonstration and experiments validate the usefulness and performance of the proposed system.

• The KIPS Transactions:PartC
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• v.16C no.2
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• pp.217-222
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• 2009

This paper proposes the number of Optical Network Unit (ONU) based priority scheduling mechanism over Ethernet Passive Optical Network (EPON) to support multicast Quality of Service (QoS) for Internet Protocol Television (IPTV) service. Multicast QoS is effected by the receivers' number of a packet because multicast efficiency is determined by how many receivers are received multiple copied packets. Therefore, the proposed mechanism assigns a priority with the number of ONUs to allocate high priority to IPTV services used by many people and firstly transmits a packet with high priority. By doing so, we show that the proposed mechanism support favorite IPTV services with better and stable QoS in spite of congestion.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.927-930
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• 2011

위성이나 케이블을 통해서 이루어지던 유료 방송 서비스가 최근에는 IPTV 라는 이름 아래 인터넷을 통해서 이루어지고 있다. IP 네트워크를 통해 콘텐츠가 전송되면서 네트워크의 대역폭을 효율적으로 사용하기 위해 멀티캐스트를 통해 이루어진다. 멀티캐스트는 IP 환경에서 동일한 내용의 데이터를 여러명의 특정한 그룹의 수신자에게 동시에 전송하는 것을 말하며, 이때 그룹을 관리하기 위해 인터넷 그룹 관리 프로토콜(Internet Group Management Protocol, IGMP)이 사용된다. IGMP에는 접근제어와 같은 보안 기능을 제공하지 않고 있으며, IPTV와 같은 유료 방송 서비스에서는 멀티캐스트를 통해 전송 되는 콘텐츠를 보호하기위해 접근제어시스템(Conditional Access System, CAS)을 사용한다. 그러나 CAS를 통해 콘텐츠를 보호 하더라도, IGMP에는 보안 기능이 없다는 근본적인 문제에 의해 사용자의 TV 시청을 방해할 수 있다는 가능성이 남아있다. 본 논문에서는 이러한 문제를 해결하기 위해 CAS가 운영되면서 교환된 키를 사용해 IGMP메시지에 보안기능을 추가한 기법을 제안한다.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.32-43
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• 2010

IPTV is an emerging technology that combines both broadcasting and tele-communication technologies, and provides various multi-media contents to the service subscribers. In general, IPTV broadcasters transmit scrambled signals (multi-media contents) to the paying subscribers, and the users within the acknowledged network descramble the signals using the smart-card. That is, users are verified through communication between STB (Set-Top Box) and smart-card. In 2004, Jiang et al. proposed a secure protocol regarding the verification process. The method has been modified and enhanced by several following research works. However, all the methods that have been proposed so far required modular exponentiation operations which may raise the smart-card costs. In this paper, we propose a new efficient mutual authentication and session-key establishment protocol using only hash functions and exclusive-or operations, and show that the proposed protocol is still secure under various security attacks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3958-3971
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• 2016

With Internet of Things (IoT) technology, home environment becomes smarter than ever. Not only smart devices such as smart phone or smart TV, but also various IoT devices including sensor, smart thermostat, and smart scale has now become very common on the market. These devices have connectivity to the Internet, so that user can read data from the device or control the device using Internet technology. However, due to diversity of smart home requirements, device collaboration in smart home remains a challenging task still. Usually smart home is built with various technologies to fulfill its own purpose, and these purposes cover very wide area from controlling low-power sensor devices to controlling high-performance devices like smart TV and smart phone. This variety of smart home requirements makes smart home very complicated due to mixed network architecture, protocol and technology. In this paper, a framework to enable managing and collaborating heterogeneous IoT devices in smart home environment is proposed. Several programming models are defined in the proposed framework to make application development for heterogeneous devices more intuitive. The proposed framework has been implemented as a web service, and a case study with real-world smart home IoT devices is presented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.1-12
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• 2008

The multimedia streaming service in NGN architecture is not only to deliver video streaming (VoD, Broadcasting TV, etc.) but also to provide new services and service bundles, such as Triple Play (IPTV + VoIP + Internet). Among these services, Internet Protocol Television (IPTV) is becoming a convergence of communication, content, computing, as well as an integration of broadcasting and telecommunication services. In this paper, we addresses enhanced IPTV management scheme aspect of E2E from Home Network to Head End Center over NGN to support efficient service management with a full quality of service (QoS) guarantee.

• Journal of the Optical Society of Korea
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• v.11 no.3
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• pp.101-107
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• 2007

In this paper, we have presented the results of Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) based fiber-to-the-home (FTTH) field trial test which was held in the city of Gwangju. We have implemented an injection locked Fabry-Perot Laser Diode (FP-LD) based WDM-PON system and reliably delivered Internet Protocol TV (IP-TV), networked Personal Video Recorder (N-PVR), High-Definition Video on Demand (HD-VoD), Education on Demand (EoD) and Internet service as FTTH service through the system during the field trial test. We have also verified that the WDM-PON system worked well to provide quality of service (QoS) guaranteed 100Mbps bandwidth per subscriber. Furthermore, we have presented network designing issues in Outside Plant (OSP) and Customer Premises Network (CPN) that should be overcome to efficiently deploy FTTH service. Finally, based on the field trial test results, we proposed FTTH service deployment strategies.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.183-190
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• 2012

Internet Protocol Television(IPTV) is the use of an IP broadband network to deliver television (cable TV type) services to the end user. Traditional telecommunications service providers as well as alternate service providers and Internet service providers can utilize their IP networks (and broadband consumer access) to deliver broadcast TV, Video on Demand (VOD) and other Internet services to the consumer. As digital technologies progress, illegal copy and redistribution of IPTV content become easier and simpler. Therefore it is required to protect IPTV content or service. In this paper, we analyze the security threats and requirements. We also discuss related issues and solutions for IPTV.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5981-5997
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• 2017

Advanced Television Systems Committee (ATSC) produced ATSC 2.0 standard, which has been used for a HD/SD digital broadcasting service with MPEG-2 Transport Stream (TS) as a delivery protocol. Recently, users might want to consume multimedia services without being constrained by transport network. However, MPEG-2 TS is not suitable protocol for IP network. Thus, ATSC has enacted ATSC 3.0 standard, which is designed for a hybrid service through a conversion of both broadcasting and broadband channels. The ATSC 3.0 specifies delivery protocols as MPEG Media Transport (MMT) for a broadcasting environment and Dynamic Adaptive Streaming over HTTP (DASH) for a broadband. However, it seems difficult to combine broadcast and broadband for hybrid broadcasting, and it is difficult to synchronize media data between MMT and DASH. This paper suggests various new service scenarios to be brought up by a hybrid broadcasting, ATSC 3.0, and also proposes a stable mechanism for switching contents between different delivery protocols such as MMT and DASH.