[281] | Daniela Pohl, Abdelhamid Bouchachia, Information Propagation in Social Networks during Crises: A Structural Framework, Chapter in Propagation Phenomena in Real World Networks (Dariusz Krol, Damien Fay, Bogdan Gabrys, eds.), Springer London, London, UK, pp. 293-309, 2015.
[bib] [doi] [abstract]
Abstract: In crisis situations like riots, earthquakes, storms, etc. information plays a central role in the process of organizing interventions and decision making. Due to their increasing use during crises, social media (SM) represents a valuable source of information that could help obtain a full picture of people needs and concerns. In this chapter, we highlight the importance of SM networks in crisis management (CM) to show how information is propagated through. The chapter also summarizes the current state of research related to information propagation in SM networks during crises. In particular three classes of information propagation research categories are identified: network analysis and community detection, role and topic-oriented information propagation, and infrastructure-oriented information propagation. The chapter describes an analysis framework that deals with structural information propagation for crisis management purposes. Structural propagation is about broadcasting specific information obtained from social media networks to targeted sinks/receivers/hubs like emergency agencies, police department, fire department, etc. Specifically, the framework aims to identify the discussion topics, known as sub-events , related to a crisis (event) from SM contents. A brief description of techniques used to detect topics and the way those topics can be used in structural information propagation are presented.
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[280] | Christopher Mueller, Stefan Lederer, Reinhard Grandl, Christian Timmerer, Oscillation Compensating Dynamic Adaptive Streaming over HTTP, In Proceedings of 2015 IEEE International Conference on Multimedia and Expo (ICME) (Enrico Magli, Stefano Tubaro, Anthony Vetro, eds.), IEEE, Los Alamitos, CA, pp. 1-6, 2015.
[bib] [doi] [pdf] [abstract]
Abstract: Streaming multimedia over the Internet is omnipresent but still in its infancy, specifically when it comes to the adaptation based on bandwidth/throughput measurements, clients competing for limited/shared bandwidth, and the presence of a caching infrastructure. In this paper we present a buffer-based adaptation logic in combination with a toolset of client metrics to compensate for erroneous adaptation decisions. These erroneous adaptation decisions are due to insufficient network information available at the client and issues introduced when multiple clients compete for limited/shared bandwidth and/or when caches are deployed. Our metrics enable the detection of oscillations on the client - in contrast to server-based approaches - and provide an effective compensation mechanism. We evaluate the proposed adaptation logic, which incorporates the oscillation detection and compensation method, and compare it against a throughput-based adaptation logic for scenarios comprising competing clients with and without caching enabled. In anticipation of the results, we show how the presented metrics detect oscillation periods and how such undesirable situations can be compensated while increasing the effective media throughput of the clients.
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[279] | Christian Kreuzberger, Benjamin Rainer, Hermann Hellwagner, Modelling the Impact of Caching and Popularity on Concurrent Adaptive Multimedia Streams in Information-Centric Networks, In IEEE International Conference on Multimedia Expo Workshops (Cesana Matteo, ed.), IEEE, Los Alamitos, CA, USA, pp. 1-6, 2015.
[bib] [doi] [pdf] [abstract]
Abstract: The Internet is nowadays mainly used for streaming of multimedia content, something it was not built for originally. To guarantee user satisfaction, one of the key concepts of the Internet as we know it is bandwidth sharing. While this concept is necessary to provide stability in the network, several issues can arise with adaptive multimedia streaming, e.g., efficiency and stability. Considering Information-Centric Networking (ICN) and its network-inherent caching, those issues tend to become worse. Many researchers have proposed to use traffic shaping on the server to enable fair bandwidth sharing and stabilize clients. However, existing research does not consider content popularity and in-network caching. The contribution of this paper is two-fold. First, we propose a cache-aware traffic shaping policy, in order to guarantee seamless playback of videos. Second, based on content popularity, we calculate an average video quality achieved by this traffic shaping policy for various cache sizes, to show the impact of popularity and caching for multimedia streaming in ICN.
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[278] | Christian Kreuzberger, Daniel Posch, Hermann Hellwagner, A Scalable Video Coding Dataset and Toolchain for Dynamic Adaptive Streaming over HTTP, In Proceedings of the 6th ACM Multimedia Systems Conference (Tsang Ooi Wei, ed.), ACM, New York, NY, USA, pp. 213-218, 2015.
[bib][url] [doi] [pdf] [abstract]
Abstract: With video streaming becoming more and more popular, the number of devices that are capable of streaming videos over the Internet is growing. This leads to a heterogeneous device landscape with varying demands. Dynamic Adaptive Streaming over HTTP (DASH) offers an elegant solution to these demands. Smart adaptation logics are able to adjust the clients' streaming quality according to several (local) parameters. Recent research indicated benefits of blending Scalable Video Coding (SVC) with DASH, especially considering Future Internet architectures. However, except for a DASH dataset with a single SVC encoded video, no other datasets are publicly available. The contribution of this paper is two-fold. First, a DASH/SVC dataset, containing multiple videos at varying bitrates and spatial resolutions including 1080p, is presented. Second, a toolchain for multiplexing SVC encoded videos is provided, therefore making our results reproducible and allowing researchers to generate their own datasets.
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[277] | Hermann Hellwagner, Severin Kacianka, Adaptive Video Streaming for UAV Networks, In MoVid '15 Proceedings of the 7th ACM International Workshop on Mobile Video (Pal Halvorsen, Nikil Dutt, eds.), ACM International Conference on Multimedia Systems, New York, USA, pp. 25-30, 2015. (to appear)
[bib] [doi] [abstract]
Abstract: The core problem for any adaptive video streaming solution, particularly over wireless networks, is the detection (or even prediction) of congestion. IEEE 802.11 is especially vulnerable to fast movement and change of antenna orientation. When used in UAV networks (Unmanned Aerial Vehicles), the network throughput can vary widely and is almost impossible to predict. this paper evaluates an approach originally developed by Kofler for home networks, in a single-hop UAV wireless network setting: the delay between the sending of an IEEE 802.11 packet and the receipt of its corresponding acknowledgement is used as an early indicator of the link quality and as a trigger to adapt (reduce or increase) the video stream' s bitrate. Our real-world flight-tests indicate, that this avoids congestion and can frequently avoid the complete loss of video pictures which happens without adaptation.
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[276] | Florian Bacher, Benjamin Rainer, Hermann Hellwagner, Towards Controller-aided Multimedia Dissemination in Named Data Networking, In Proceedings of IEEE International Conference on Multimedia and Expo Workshops (available not, ed.), IEEE, Los Alamitos, CA, USA, pp. 1-6, 2015.
[bib] [doi] [pdf] [abstract]
Abstract: Software Defined Networking (SDN) and Named Data Networking (NDN) are two topics which have received lots of attention in the networking research community in recent years. While both have emerged independently from each other we believe that their core features can be well aligned to each other. Hence combining both may hold potential benefits for network operators. In this paper we investigate the advantage of having a central SDN controller which is aware of the complete topology of an underlying NDN network. In our approach we use the controller for routing Interests for names unknown to the forwarding elements and to find alternative routes in case of link congestion. Another advantage of SDN is the ability to analyze and control the network on an application-layer component which communicates with the controller. This allows the development of application-aware networks that support the specific needs of the applications that use them. As an example use case we assumed a network whose main purpose is to disseminate multimedia content with Zipf-distributed popularity among users. Having an application layer which knows about content popularity statistics we improve the dissemination of multimedia content by instructing dedicated nodes in the network to prefetch content which is expected to become popular in their geographical region or autonomous system (AS) in the near future. The aim of this approach is to reduce the distance to potential consumers and reduce the load of the core network.
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[275] | Christian Timmerer, Carsten Griwodz, Ali Cengiz Begen, Thomas Stockhammer, Bernd Girod, Guest Editorial: Adaptive Media Streaming, In IEEE Journal on Selected Areas in Communications, IEEE Communications Society, vol. 32, no. 4, New York, NY, USA, pp. 681-683, 2014.
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[274] | Christian Timmerer, Benjamin Rainer, The Social Multimedia Experience, In IEEE Computer, IEEE Computer Society, vol. 47, no. 3, Los Alamitos, CA, USA, pp. 67-69, 2014.
[bib] [pdf] [abstract]
Abstract: Inter-destination multimedia synchronization and quality of experience are critical to the success of social TV, which integrates television viewing with social networking.
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[273] | Christian Timmerer, Ali Cengiz Begen, Over the Top Content Delivery: State of the Art and Challenges Ahead, In Proceedings of the 2014 ACM Multimedia Conference (Kien Hua, Yong Rui, Ralf Steinmetz, Alan Hanjalic, Apostol Natsev, Wenwu Zhu, eds.), ACM, New York, NY, USA, pp. 1231-1232, 2014.
[bib] [doi] [pdf] [slides] [abstract]
Abstract: In this tutorial we present state of the art and challenges ahead in over-the-top content delivery. It particular, the goal of this tutorial is to provide an overview of adaptive media delivery, specifically in the context of HTTP adaptive streaming (HAS) including the recently ratified MPEG-DASH standard. The main focus of the tutorial will be on the common problems in HAS deployments such as client design, QoE optimization, multi-screen and hybrid delivery scenarios, and synchronization issues. For each problem, we will examine proposed solutions along with their pros and cons. In the last part of the tutorial, we will look into the open issues and review the work-in-progress and future research directions.
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[272] | Christian Timmerer, Markus Waltl, Benjamin Rainer, Niall Murray, Sensory Experience: Quality of Experience Beyond Audio-Visual, Chapter in Quality of Experience: Advanced Concepts, Applications and Methods (Sebastian Möller, Alexander Raake, eds.), Springer, Heidelberg, pp. 351-365, 2014.
[bib] [abstract]
Abstract: This chapter introduces the concept of Sensory Experience which aims to define the Quality of Experience (QoE) going beyond audio-visual content. In particular, we show how to utilize sensory effects such as ambient light, scent, wind, or vibration as additional dimensions contributing to the quality of the user experience. Therefore, we utilize a standardized representation format for sensory effects that are attached to traditional multimedia resources such as audio, video, and image contents. Sensory effects are rendered on special devices (e.g., fans, lights, motion chair, scent emitter) in synchronization with the traditional multimedia resources and shall stimulate also other senses than hearing and seeing with the intention to increase the Quality of Experience (QoE), in this context referred to as Sensory Experience.
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[271] | Christian Timmerer, MPEG Column: 107th MPEG Meeting, In ACM SIGMultimedia Records, ACM, vol. 6, no. 1, New York, NY, USA, pp. 1-2, 2014.
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[270] | Christian Timmerer, Markus Waltl, Benjamin Rainer, Stefan Lederer, Hermann Hellwagner, Enhancing 3D Video to enable a Fully Immersive Sensory Experiences, In IEEE Multimedia Communications Technical Committee E-Letter, IEEE Communications Society [online], vol. 9, no. 1, New York, NY, USA, pp. 23-26, 2014.
[bib][url] [pdf] |
[269] | Christian Timmerer, Christopher Mueller, Stefan Lederer, Adaptive Media Streaming over Emerging Protocols, In 2014 NAB Broadcast Engineering Conference Proceedings & CD (not available, ed.), National Association of Broadcasters (NAB), Washington DC, USA, pp. 4, 2014.
[bib] [pdf] [slides] [abstract]
Abstract: The emerging MPEG standard Dynamic Adaptive Streaming over HTTP (MPEG-DASH) is designed for media delivery over the top of existing infrastructures and enables smooth multimedia streaming towards heterogeneous devices including both wired and wireless environments. The MPEG-DASH standard was designed to work with HTTP-URLs but mandates neither the actual version nor which underlying protocols to be used. This paper will provide a detailed introduction into emerging protocols (HTTP/2.0 and beyond) to be used in the context of adaptive media streaming, specifically DASH.
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[268] | Stefan Rass, Benjamin Rainer, Vavti Matthias, Johannes Göllner, Andreas Peer, Stefan Schauer, Secure Communication over Software-Defined Networks, In International Conference on Software-Defined and Virtualized Future Wireless Networks (A n, ed.), Springer, R, I, pp. 0-0, 2014.
[bib] |
[267] | Benjamin Rainer, Christian Timmerer, A Subjective Evaluation using Crowdsourcing of Adaptive Media Playout utilizing Audio-Visual Content Features, In In Proceedings of the IEEE Network Operations and Management Symposium (IEEE NOMS 2014) (Hanan Lutfiyya, Piotr Cholda, eds.), IEEE, Los Alamitos, CA, USA, pp. 0-0, 2014.
[bib][url] [pdf] [abstract]
Abstract: Synchronizing multimedia playback among geographically distributed clients is a challenging task and is referred to as Inter-Destination Media Synchronization (IDMS). In this paper we discuss the uses cases of IDMS as identified within the SocialSensor Project and based on these use cases we derive a novel Adaptive Media Playout (AMP) scheme which aims on carrying out the process of synchronizing the media playback at the clients to a given synchronization point. We propose how visual and acoustic features can be used to achieve a QoE-aware and context-aware AMP scheme.
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[266] | Matthais Klusch, Patrick Kapahnke, Xiaoqi Cao, Benjamin Rainer, Christian Timmerer, Stefan Mangold, MyMedia: Mobile Semantic Peer-to-Peer Video Search and Live Streaming, In Proceedings of the 11th International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (Moustafa Youssef, ed.), ACM, New York, NY, USA, pp. 10, 2014.
[bib][url] [pdf] [abstract]
Abstract: Mobile peer-to-peer (P2P) computing with applications such as for video on demand, file sharing, and video conferencing is gaining momentum based on new standards and technologies such as IETF PPSP, WiFi-Direct and BitTorrent live streaming. In this paper, we describe the mobile system MyMedia, that allows users to search, share and experience videos and live recordings using P2P and at the best quality possible with respect to available network capacity. In particular, the MyMedia system features a high-precision semantic P2P search and dynamic network-adaptive P2P live streaming of MPEG videos over HTTP based on the ISO/IEC standard MPEG-DASH from mobile to mobile devices in unstructured wireless P2P networks. These features have been integrated in the mobile application TIFF EventLive of the 54th Thessaloniki international film festival. The evaluation of their performance and device energy consumption, and a first user evaluation at the festival showed that the MyMedia system is suitable and accepted by users for its purpose in practice. The MyMedia system is available as open-source software for the Android operating system.
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[265] | Benjamin Rainer, Christian Timmerer, A Generic Utility Model Representing the Quality of Sensory Experience, In ACM Transactions on Multimedia Computing, Communications, and Applications (TOMM) (Ralf Steinmetz, Gheorghita Ghinea, Christian Timmerer, Weisi Lin, Stephen Gulliver, Zheng-Jun Zha, Lei Zhang, Max Mühlhäuser, Alan Smeaton, eds.), ACM, New York, NY, USA, pp. 14:1-14:17, 2014.
[bib] [pdf] |
[264] | Benjamin Rainer, Christian Timmerer, Self-Organized Inter-Destination Multimedia Synchronization For Adaptive Media Streaming, In Proceedings of the 22st ACM International Conference on Multimedia (ACM, ed.), ACM, New York, NY, USA, pp. 10, 2014.
[bib][url] [pdf] [abstract]
Abstract: Social networks have become pervasive and have changed the way of social interaction. The traditional TV experience drifts from an event tied to a certain place with the family or friends to a location-independent and distributed social experience. Additionally, more and more video on-demand services adopt a pull-based streaming approach. In order to provide a synchronized and distributed TV experience we introduce a self-organized Inter-Destination Multimedia Synchronization (IDMS) framework for adaptive media streaming. In particular, we extend the principles of IDMS to adaptive media streaming over HTTP (i.e., MPEG-DASH) and enable a synchronized multimedia playback among geographically distributed clients. Therefore, we introduce session management to MPEG-DASH and for negotiating on a reference playback timestamp among the participating peers in an IDMS session we propose a distributed control scheme. We evaluate our proposed scheme with respect to scalability and time required for negotiating on the reference playback timestamp. Furthermore, we investigate how to compensate the identified asynchronism by using adaptive media playout with respect to the Quality of Experience (QoE). Therefore, we define a temporal distortion measure for audio and video which allows us to model the impact of playback rate variations on the QoE. This measure is evaluated by conducting a subjective quality assessment using crowdsourcing.
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[263] | Benjamin Rainer, Christian Timmerer, Quality of Experience of Web-based Adaptive HTTP Streaming Clients in Real-World Environments using Crowdsourcing, In First International Workshop on VideoNext: Design, Quality and Deployment of Adaptive Video Streaming (N N, ed.), ACM, Australia, Sydney, pp. 1-6, 2014.
[bib] [pdf] |
[262] | Benjamin Rainer, Christian Timmerer, A Quality of Experience Model for Adaptive Media Playout, In Sixth International Workshop on Quality of Multimedia Experience (QoMEX 2014) (Stefan Winkler, ed.), IEEE, Singapore, Singapore, pp. 1-4, 2014.
[bib] [pdf] [abstract]
Abstract: In the past decade Adaptive Media Playout (AMP) has been intensively studied with respect to the detection of when to increase or decrease the playback rate in order to maintain a certain buffer fill state. In this paper we subjectively assess the QoE of AMP with respect to non-periodically and randomly selected content sections of a video sequence by us- ing crowdsourcing. Furthermore, we introduce features that allow to quantify the distortion for audio and video that are caused by increasing or decreasing the playback rate. With these preliminaries we study the correlation between the introduced features and the subjectively assessed QoE. Therefore, we derive a utility model that allows to estimate the QoE with the introduced features. We instantiate and validate the model by the use of the data gathered by the conducted study.
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[261] | Christian Raffelsberger, Hermann Hellwagner, Combined Mobile Ad-Hoc and Delay/Disruption-Tolerant Routing, In Proceedings of the 13th International Conference on Ad-hoc, Mobile, and Wireless Networks (ADHOC-NOW '14) (Song Guo, Pietro Manzoni, Jaime Lloret, Stefan Ruehrup, eds.), Springer, vol. 8487, Berlin Heidelberg, pp. 1-14, 2014.
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[260] | Daniel Posch, Christian Kreuzberger, Benjamin Rainer, Hermann Hellwagner, Using In-Network Adaptation to Tackle Inefficiencies Caused by DASH in Information-Centric Networks, In Proceedings of the 10th International Conference on Emerging Networking Experiments and Technologies, VideoNext Workshop (Colin Dixon, ed.), ACM Digital Library, New York, NY, USA, pp. 1-6, 2014.
[bib] [pdf] [abstract]
Abstract: The consumption of audio-visual content is the most dominant traffic source in today's Internet. Novel architectural approaches, such as Information-Centric Networking (ICN), are developed to support efficient multimedia dissemination. As ICN and MPEG-DASH have several concepts in common, recent proposals consider a fusion of both technologies. However, MPEG-DASH relies on pure client-driven adaptation. This often rather selfish adaptation strategy inhibits benefits gained from ICN's inherent caching and multi-path transmission capabilities. In order to overcome this challenge, the contribution of this work is the integration of in-network adaptation (INA) in ICN. We illustrate that INA can be realized despite ICN's content-based security model. Our proposal rests on scalable content, which enables INA without management and transmission overhead.
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[259] | Daniel Posch, Christian Kreuzberger, Benjamin Rainer, Hermann Hellwagner, Client Starvation: A Shortcoming of Client-driven Adaptive Streaming in Named Data Networking, In Proceedings of the 1st ACM Conference on Information-Centric Networking (Paulo Mendes, ed.), ACM Digital Library, New York, NY, USA, pp. 1-2, 2014. (to appear)
[bib][url] [doi] [pdf] [abstract]
Abstract: Information-centric Networking (ICN) as a potential Future Internet architecture has to efficiently support the consumption of multimedia content. Recent proposals consider the reuse of MPEG-DASH to provide adaptive streaming in ICN. Due to the fact that MPEG-DASH relies on pure client-driven adaptation, it encounters difficulties dealing with ICN's inherent caching and multi-path transmission. By conducting simulations using the concrete ICN approach Named Data Networking (NDN), we show that pure client-driven adaptation leads to shortcomings. Furthermore, we propose to use in-network adaptation based on scalable content for overcoming these shortcomings in NDN.
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[258] | Amro Al-Akkad, Christian Raffelsberger, Alexander Boden, Leonardo Ramirez, Andreas Zimmermann, Tweeting 'When Online is Off'? Opportunistically Creating Mobile Ad-hoc Networks in Response to Disrupted Infrastructure, In Proceedings of the 11th International Conference on Information Systems for Crisis Response and Management (ISCRAM '14) (Star Roxanne Hiltz, Mark S Pfaff, Linda Plotnick, Patrick C Shih, eds.), The Pennsylvania State University, USA, University Park, Pennsylvania, USA, pp. 657-666, 2014.
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[257] | Amro Al-Akkad, Christian Raffelsberger, How do I get this App? A Discourse on Distributing Mobile Applications Despite Disrupted Infrastructure, In Proceedings of the 11th International Conference on Information Systems for Crisis Response and Management (ISCRAM '14) (Star Roxanne Hiltz, Mark S Pfaff, Linda Plotnick, Patrick C Shih, eds.), The Pennsylvania State University, USA, University Park, Pennsylvania, USA, pp. 560-564, 2014.
[bib] [pdf] |