组播环境下IPTV快速频道切换方法

互联网已经深入到人们的日常生活当中，在互联网的影响下，应用组播电视的用户不断增加，然而，在频道切换的过程中，用户需要等待较长时间，严重影响用户体验。本文主要对组播环境下IPTV快速频道切换方法进行研究，促使视频的缓存能够快速完成，从而减少频道切换时间，提高用户体验以及促进IPTV技术的发展。     

IPTV用户行为分析

本文针对IPTV业务。模拟用户观看IPTV的行为。通过仿真得到了频道的切换频度变化曲线以及在线频道数目变化曲线。分析了用户数目对组网的影响。指出了实际组网应该采用的转发方式。     

基于服务器的IPTV快速频道切换技术

IPTV网络中的直播频道通常采用多播方式进行发送,STB通过加入多播组的方式来进行频道切换,这样使得IPTV频道切换往往比传统电视时间更长,在用户体验方面成为制约IPTV业务发展的硬伤。以CDN技术架构为基础,较详细地论述了基于服务器的FCC技术,该理论在实践中已得到应用,有较高的理论参考价值和实用价值。     

一种改进的IPTV快速频道切换技术方案

频道切换时间是IPTV业务服务质量的重要指标之一,快速的频道切换能显著提升IPTV业务的用户体验.本文提出一种改进的基于视频典型帧提取的快速频道切换技术方案,该方案可用于改善IPTV用户对于频道切换速度的体验时间.     

IPv6组播技术及其在IPTV中的应用

本文在研究IPv6组播技术的基础上,深入分析IPTV直播业务模型,从基于MLD的频道切换和可控组播技术分析IPv6组播技术在IPTV中的应用。     

基于单播流的IPTV频道切换提速方案研究

IPTV多播频道切换时延是IPTV业务用户体验质量(QoE)指标的重要组成部分。分析了影响频道切换时间的诸多因素,并对一种由FCC服务器下发特制的以I帧为起始的单播节目流提升频道切换时间的方法进行了具体的理论分析和测试验证。     

IPTV频道切换技术研究

本文在分析IPTV直播业务体系的基础上,深入研究频道切换的原理和流程,从频道切换时间、QDI的影响和用户行为模式等方面分析IPTV频道切换性能的关键制约因素,提出提高频道切换性能的建议。     

IPAD VCC切换优化方法

本文从IPTV机顶盒（STB）频道切换谈起。在简要回顾了MPEG-2协议后,主要分析7IPTV广告机（IPAD）VCC切换慢的问题,给出了可行的优化方案,并指出了该方案进一步优化的空间。     

一种在网络地址转换后实现IPTV频道快速切换功能的技术方案

快速频道切换是一种减少IPTV切台时间的技术。运营商广泛应用的IPTV频道快速切换标准都要求机顶盒与频道快速切台系统可以实现路由可达。然而,在采用全路由模式的家庭网关场景下,机顶盒IP地址会经过网络地址转换(NAT),无法实现与频道快速切台系统的路由可达。本文提出了一种在网络地址转换后实现IPTV频道快速切换功能的方案,并在广东省广播电视网络股份有限公司经过实践应用验证,效果良好。     

城域网之组播部署方案的介绍与选择

随着IPTV业务的不断开展,在现有网络中如何利用原有设备开展IPTV业务成为IPTV顺利发展的重要一环.目前IPTV技术标准对承载网提出了不同于普通以太网传输的要求:在管理上,要有针对用户和节目的网络带宽管理、VLAN功能管理、精细播放权限控制、频道切换时间控制和组播业务安全等新的功能;在传输上,IPTV业务的流媒体特性决定了用户需要长时间占用网络带宽,而且要实时保证网络的QoS.     

A novel fountain code-based mobile IPTV multicast system architecture over WiMAX network

In this paper, we present a novel fountain code-based mobile IPTV multicast system architecture over WiMAX network. In the proposed system, the transmission algorithm at a base station determines the control parameters of a fountain-encoded IPTV multicast stream adaptively to the wireless link states of subscribers in order to provide a stable IPTV service with minimum resource usage on WiMAX network, and the channel grouping algorithm at a server makes near-optimal channel grouping based on channel selection preferences to pursue an effective tradeoff between the channel zapping time and the processing complexity of a subscriber. Finally, experimental results are provided to show the performance of the proposed system.     

QoE-aware mobile IPTV channel control algorithm over WiMAX network

In this paper, we present an effective IPTV channel control algorithm that improves the quality of experience for subscribers to mobile IPTV services over WiMAX network. We consider the video quality of TV channels and the channel zapping time as quality of experience metrics. The proposed algorithm controls the channel distribution state and the target bit rate of TV channels based on the channel preference information of subscribers to achieve an effective trade-off between channel zapping time and video quality. Finally, simulation results are provided to demonstrate the performance of the proposed system.     

An Effective Channel Control Algorithm for Integrated IPTV Services Over DOCSIS CATV Networks

In this paper, we present an effective IPTV channel control algorithm that guarantees a seamless channel change and provides a fast data communication service simultaneously via controlling the usage levels of uplink and downlink resources over DOCSIS CATV networks. The proposed algorithm treats the number of adjacent channels and the assigned grant interval as control variables to reduce the network delay part of channel zapping time and improve the quality-of-service of the uplink and downlink. Finally, the experimental results are provided to show the performance of the proposed algorithm.     

An Effective IPTV Channel Control Algorithm Considering Channel Zapping Time and Network Utilization

This paper presents a simple but effective IPTV channel control algorithm that keeps channel zapping time in the tolerable range with high network utilization. The proposed algorithm controls channel zapping time by adjusting the number of broadcasting channels that are located close to users over IP networks and the number of additional I-frames inserted into each channel, based on the user's channel preference information. Finally, experimental results are provided to show the performance of the proposed algorithm.     

Reducing channel change delay in IPTV by predictive pre-joining of TV channels

One of the major concerns of IPTV network deployment is channel change delay (also known as zapping delay). This delay can add up to 2 s or more, and its main culprits are synchronisation and buffering of the media streams. Proving the importance of the problem is the already significant amount of literature addressing it. We start this paper with a survey of techniques proposed to reduce IPTV channel change delay.Then, by analysing an extensive dataset from an operational IPTV provider - comprising 255 thousand users, 150 TV channels, and covering a 6-month period - we have observed that most channel switching events are relatively predictable: users very frequently switch linearly, up or down to the next TV channel. This fact motivated us to use this dataset to analyse in detail a specific type of solutions to this problem, namely, predictive pre-joining of TV channels. In these schemes each set top box (STB) simultaneously joins additional multicast groups (TV channels) along with the one that is requested by the user. If the user switches to any of these channels the switching latency is virtually eliminated, not affecting therefore user's experience.We start by evaluating a simple scheme, where the neighbouring channels (i.e., channels adjacent to the requested one) are pre-joined by the STB during zapping periods. Notwithstanding the simplicity of this scheme, trace-driven simulations show that the zapping delay can be virtually eliminated for a significant percentage of channel switching requests. For example, when sending the previous and the next channel concurrently with the requested one, for only 1 min after a zapping event, switching delay is eliminated for close to half of all channel switching requests. Importantly, this result is achieved with a negligible increase of bandwidth utilisation in the access link. Other more complex schemes where user behaviour is tracked were also evaluated, but the improvement over the simple scheme was insignificant.     

TR069协议在IPTV终端管理系统中的研究与应用

根据目前IPTV业务和互动需求,设计一套实时有效的IPTV终端管理系统具有极大的现实意义.详细分析了TR069协议及其关键技术,着重对IPTV机顶盒进行研究,实现了TR069协议在IPTV机顶盒终端管理业务中的应用.测试结果显示,所设计的IPTV机顶盒终端管理系统能够满足IPTV终端管理的实时性、有效性需求.     

Personally customizable content authoring service for Internet Protocol television subscribers

In this paper, we propose a personally customizable content authoring service (C2Channel) using an Internet Protocol television (IPTV) platform, in which a user terminal such as a PC or set‐top box sends various kinds of multimedia files from a camera or camcorder to a remotely located authoring server (C2Channel server). The C2Channel server creates personalized content in real time by combining special effects with the multimedia files transmitted from the user terminal and then retransmits them to a predefined relevant service group as a personal IPTV channel through an IPTV network provider. This content authoring service supplies an automatic multimedia editing/composition service and offers unicast, multicast, and groupcast services for a large number of interested groups via an IPTV‐based real‐time media delivery platform (Open Live IPTV Engine [OLIVE]), in which a service management server is used for user identification through the IPTV personal channel. Because this platform uses a remote server resource when authoring personally customizable content, resources remaining at the user's terminal can be variously utilized. Copyright © 2012 John Wiley & Sons, Ltd.     

基于分层聚类分析的IPTV业务质量研究与应用

IPTV是基于IP协议的视频业务,与互联网数据业务对网络质量的要求存在很多不同,对网络带宽、QoS性能、可靠性及时延性等方面都要求更高。随着IPTV业务的推广发展和用户对业务质量要求的提高,IPTV业务质量保障变得越来越重要。因此,介绍IPTV网络承载技术,分析IPTV业务质量保障现状及不足,结合SQM系统提出了一种基于分层聚类分析的IPTV业务质量优化方案。     

Improving IPTV Forwarding Mechanism in IEEE 802.16j MMR Networks Based on Aggregation

Internet protocol television (IPTV) service depends on the network quality of service (QoS) and bandwidth of the broadband service provider. IEEE 802.16j mobile multihop relay Worldwide Interoperability for Microwave Access networks have the opportunity to offer high bandwidth capacity by introducing relay stations. However, to actually satisfy QoS requirements for offering IPTV services (HDTV, SDTV, Web TV, and mobile TV) for heterogeneous users' requests, providers must use a video server for each IPTV service type, which increases the network load, especially bandwidth consumption and forwarding time. In this paper, we present a solution for forwarding IPTV video streaming to diverse subscribers via an 802.16j broadband wireless access network. In particular, we propose a new multicast tree construction and aggregation mechanism based on the unique property of prime numbers. Performance evaluation results show that the proposed scheme reduces both bandwidth consumption and forwarding time.