• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1416-1428
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• 2016

In this paper, we address the channel zapping time problem of video streaming services based on HTTP Live Streaming (HLS) on smart Over-The-Top Set-Top Boxes (OTT STBs). Experimental analysis of the channel zapping time, show that smart OTT STBs inevitably suffer from the accumulated zapping time through channel change request, Internet Group Management Protocol (IGMP) leave/join, synchronization delay, video buffer delay, and STB processing delay when providing HLS services. As a practical solution for the zapping time reduction, an adaptive buffering method is proposed. The proposed method exploits two adaptive buffers added to the basic HLS player. These two adaptive buffers are responsible for constantly buffering previous and next channels relative to the current channel. Implementation and test results show that a stable zapping time less than one second can be achieved even under diverse video bitrate changes and varying network conditions by the proposed adaptive buffering method.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.89-91
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• 2007

Multimedia service based on interactivity, personalization, multiple channels and community distinguishes IPTV from incumbent TV. But data encoding/decoding time and image frame processing should be considered in digital TV versus analog device. Especially channel zapping time is one of the most important parameters for the service quality of IPTV. This paper proposes the mechanism for decreasing the channel zapping time with multiple decoder and image frame processing. We also implemented the multi-group video community service system using IP multicasting function supporting interactive learning service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.390-397
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• 2010

This paper presents an effective IPTV channel control algorithm considering network utilization and channel zapping time. The proposed algorithm keeps maximum average channel zapping time of each subscriber in the tolerable range with low network bandwidth usage by adjusting the type of each channel and the number of additional intra frames inserted into each channel. Finally, experimental results are provided to show the performance of the proposed algorithm.

• Journal of KIISE:Information Networking
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• v.37 no.6
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• pp.444-452
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• 2010

To avoid a channel zapping delay, the device needs to predict a next channel and must download it. Previous researches suggest algorithms based on assumption by utilizing many data. How to select and download future channels is a main issue in IPTV system. Most proposal based on assumption do not guarantees complete performance of channel zapping. In this paper, we suggest an effective method to avoid a channel zapping time with a constant performance by using a number remote controller key information.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.21-28
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• 2009

To provide IPTV service successfully, we have to guarantee quality of service (QoS). However, in IPTV service, when we change channels, channel zapping delay will cause lower subscriber's satisfaction. Also, we can not provide IPTV service efficiently by limited bandwidth problem. In this paper, we propose a new enhanced IPTV transmission scheme to solve the two types problems using RACR (Robust Aggregation Control Router) which can control bandwidth and channel zapping time.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.36-38
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• 2014

디지털 케이블 방송 시스템은 기존의 아날로그 케이블방송과 달리 하나의 6MHz 주파수 대역에 여러 방송채널들을 전송하고 있다. 즉, MPEG2 또는 H.264/AVC 등 비디오 압축 방식으로 인코딩된 여러 방송채널들과 각 채널의 대한 정보를 제공하기 위한 PSI 정보를 생성하여 멀티플렉싱하여 6MHz 주파수 대역으로 전송하는 방식으로 서비스를 제공한다. 하지만, 근본적으로 디지털 케이블 방송에서는 방송채널 변경 시 QAM Tuner의 주파수 Locking 및 디멀티플레싱, PSI 정보 파싱을 통한 채널 정보 획득, 비디오 및 오디오 디코딩을 위한 RAP(Random Access Point) 획득, 스크램블채널을 위한 ECM 획득 등의 시간 지연이 발생함에 따라 아날로그 케이블방송과 비교하여 상당한 채널 변경 지연이 발생한다. 이러한 이유로 디지털 케이블 방송 서비스의 품질 향상을 위해서는 채널 변경 시간 지연을 최소화하기 위한 연구가 필요하다. 따라서, 본 논문에서는 채널 변경 지연 요소들을 분석하고, 채널 변경 지연을 최소화하기 위한 기법을 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.591-594
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• 2013

This study examines how OTT service changes the television viewing experience, what are the underlying dimensions that difference of viewing behavior and experiences between OTT service and old television media. The result showed the characteristic of viewing experiences through OTT service that social viewing, channel zapping by sharing information, multi viewing, de-contextualized viewing space. Specifically, television as a family media turned into a personalized media, social viewing generalized so called 'lean forward' with each other using texts and images at the same time. In particular, information on the content and appraisal shared with each other on SNS in real time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.224-231
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• 2008

EPONs are a low cost, high speed solution to the bottleneck problem of broadband access networks. To support point-to-point and shared LAN emulation, EPONs use the multi-point control protocol (MPCP), which uses logical link identification (LLID) for frame tagging and filtering between the OLT and ONUs. In this paper, ONU-based multicast or multiple shared LAN emulation is used for IPTV channel package delivery services. Using ONU-based VLAN services, EPONs can support separate and secure connections between providers and subscribers in a simple manner. Also, IPTV channel packages can be delivered through EPONs by implementing ONU-based VLAN and IGMP snooping mechanisms. By showing fast channel zapping time of proposed architecture, I show that EPONs is suitable for IPTV channel package delivery service.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.6
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• pp.37-47
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• 2009

In this paper fast mobile multicast handover mechanism based on IEEE 802.21 MIH (Media Independent Handover) is proposed. We solve long multicast handover delay time caused by L3 movement detection mechanism of the existing mobile multicast methods. The proposed architecture adopts multicast manager concept to MIH framework in order to efficiently perform mobile multicast handover, and adds the new MIH messages dedicated for mobile multicast. Since multicast channel zapping operations of mobile users effectively make a mobile terminal handover, the architecture should consider the situations. Multicast network selection algorithm is designed by means of terminal speed and fair selection algorithm named AHP/GRA. Finally the performance of the proposed architecture against the legacy mobile multicast mechanisms is evaluated in terms of signaling cost and multicast handover delay time.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.528-536
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• 2009

Recently, the importance of IPTV providing multimedia service over IP based networks managed to provide the required level of quality of service and experience, security, interactivity and reliability has been gradually increasing by the commercialization of its service. However, the original purposes of IPTV service - contents are produced and consumed anytime, anywhere, and over any device at the same time - have not been satisfied by service providers because most services offered by service providers depend on closed IPTV platform. In this paper, we propose an open IPTV service platform that an individual or small company can easily produce contents and offer IPTV service independently from the existing closed IPTV platform.. The proposed IPTV platform exploits overlay multicast scheme to offer reasonable service under the environment where network bandwidth and processor resource are limited. It also uses CDN-like scheme to ensure the quality of transmitted contents. The performance evaluation shows that the proposed IPTV platform has the possibility of being an open IPTV platform considering its results such as the quality of transmitted contents, the transmission rate, the channel zapping time, and so on. It also shows that proposed IPTV platform could be applied to real IPTV service with continuous enhancement of its functions and user interfaces.