Browsing by Author "Aurelius, Andreas"
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Item Analysis and characterization of IPTV user behavior(2009) Yu, Geng; Westholm, Tord; Kihl, Maria; Sedano, Iñigo; Aurelius, Andreas; Lagerstedt, Christina; Ödling, Per; FACTORYToday, due to the fast development of Internet Protocol TV (IPTV), which is the combination of IP technology and two-way broadband networks, the telecom industry is undergoing fundamental changes. Network operators and service providers around the world are making significant investments in order to deliver digital video content to their subscribers. Video puts very high demands on the network and utilizes a large fraction of the available bandwidth. Consequently, it is important to understand the technical demands that IPTV requires of the network infrastructure as well as user behavior and network traffic patterns to further optimize network operation. The purpose of this paper is to characterize IPTV traffic and study end user behavior by analyzing and modeling IPTV traffic collected from a Swedish municipal network. The focus of the measurements was put on Internet Group Management Protocol (IGMP) packets. Apart from the measurement results and analysis, the paper provides background information about the technologies and issues of IPTV. IP multicast which is used for transferring Live TV content is based on the concept of a group. IGMP is used to manage the membership of multicast groups. Based on this information, traffic parameters for analysis were chosen and measured.Item Evaluation of video quality metrics on transmission distortions in H.264 coded video(2011) Sedano, Inigo; Kihl, Maria; Brunnstrom, Kjell; Aurelius, Andreas; FACTORYThe development of high-speed access networks has enabled a variety of video delivery alternatives over the Internet, for example IPTV and peer-to-peer based video services as Voddler. Consequently, the development of real-time video QoE monitoring methods is receiving large attention in the research community. We believe that the good performing objective metrics using reference information could be used to speed up the development process of real-time video QoE monitoring methods. Thus in this paper we study the accuracy of full-reference objective methods for assessing the quality degradation due to the transmission distortions. We evaluated several well-known publicly-available full-reference objective metrics on the freely available EPFL-PoliMI (Ecole Polytechnique Fédérale de Lausanne and Politecnico di Milano) video quality assessment database, which was specifically designed for the evaluation of transmission distortions. The full-reference metrics are usually evaluated using a reference which is uncompressed. Instead, we study the performance of the metrics when the reference videos are lightly compressed to ensure high quality.Item Full-reference video quality metric assisted the development of no-reference bitstream video quality metrics for real-time network monitoring(2014-01) Sedano, Iñigo; Brunnström, Kjell; Kihl, Maria; Aurelius, Andreas; FACTORYHigh-quality video is being increasingly delivered over Internet Protocol networks, which means that network operators and service providers need methods to measure the quality of experience (QoE) of the video services. In this paper, we propose a method to speed up the development of no-reference bitstream objective metrics for estimating QoE. This method uses full-reference objective metrics, which makes the process significantly faster and more convenient than using subjective tests. In this process, we have evaluated six publicly available full-reference objective metrics in three different databases, the EPFL-PoliMI database, the HDTV database, and the Live Video Wireless database, all containing transmission distortions in H.264 coded video. The objective metrics could be used to speed up the development process of no-reference real-time video QoE monitoring methods that are receiving great interest from the research community. We show statistically that the full-reference metric Video Quality Metric (VQM) performs best considering all the databases. In the EPFL-PoliMI database, SPATIAL MOVIE performed best and TEMPORAL MOVIE performed worst. When transmission distortions are evaluated, using the compressed video as the reference provides greater accuracy than using the uncompressed original video as the reference, at least for the studied metrics. Further, we use VQM to train a lightweight no-reference bitstream model, which uses the packet loss rate and the interval between instantaneous decoder refresh frames, both easily accessible in a video quality monitoring system.Item Reconstruction of incomplete decoded videos for use in objective quality metrics(2012) Sedano, Iñigo; Kihl, Maria; Brunnström, Kjell; Aurelius, Andreas; FACTORYMany full-reference objective metrics require that the original and the degraded video contain the same number of frames. Most codecs are not able to decode the video properly when the video is subject to packet losses and produce incomplete video files with lower number of frames than the original video. In this paper we present a simple method to reconstruct the degraded videos so that it has the same length as the original. Information regarding the frame numbers is inserted into the original uncompressed video and used later on to identify the missing frames and reconstruct the degraded video.Item TRAMMS: Monitoring the evolution of residential broadband Internet traffic(2010) Aurelius, Andreas; Lagerstedt, Christina; Sedano, Iñigo; Molnár, Sándor; Kihl, Maria; Mata, Felipe; FACTORYTraffic measurements in broadband access networks are crucial from several points of view. A better understanding of traffic patterns can lead to more efficient network design, which leads to energy and cost savings for the operator and improved end user services. This paper reports on selected traffic measurement results from the Celtic TRAMMS project. The measurements were performed in broadband access networks in Sweden and Spain. The vast majority of the traffic volume is video based and from peer-to-peer applications. This suggests that future access networks should be symmetrical in order to properly cope with the traffic patterns of the future. Geographic locality of end-to-end flows has been identified for incoming and outgoing traffic in Spain, which may be used to analyze peering between ISP's. Finally, we show that stricter legislation in Sweden targeting illegal file sharing led to a dramatic decrease of the traffic. This means that factors not controlled by the networking community may seriously impact traffic patterns and user behaviour thereby indicating the need for closer collaboration between researchers and network designers on one side and politicians and regulators on the other side.