Provider-Controlled Bandwidth Management for HTTP-based Video Delivery

Over the past few years, a revolution in video delivery technology has taken place as mobile viewers and over-the-top (OTT) distribution paradigms have significantly changed the landscape of video delivery services. For decades, high quality video was only available in the home via linear television or physical media. Though Web-based services brought video to desktop and laptop computers, the dominance of proprietary delivery protocols and codecs inhibited research efforts. The recent emergence of HTTP adaptive streaming protocols has prompted a re-evaluation of legacy video delivery paradigms and introduced new questions as to the scalability and manageability of OTT video delivery. This dissertation addresses the question of how to enable for content and network service providers the ability to monitor and manage large numbers of HTTP adaptive streaming clients in an OTT environment. Our early work focused on demonstrating the viability of server-side pacing schemes to produce an HTTP-based streaming server. We also investigated the ability of client-side pacing schemes to work with both commodity HTTP servers and our HTTP streaming server. Continuing our client-side pacing research, we developed our own client-side data proxy architecture which was implemented on a variety of mobile devices and operating systems. We used the portable client architecture as a platform for investigating different rate adaptation schemes and algorithms. We then concentrated on evaluating the network impact of multiple adaptive bitrate clients competing for limited network resources, and developing schemes for enforcing fair access to network resources. The main contribution of this dissertation is the definition of segment-level client and network techniques for enforcing class of service (CoS) differentiation between OTT HTTP adaptive streaming clients. We developed a segment-level network proxy architecture which works transparently with adaptive bitrate clients through the use of segment replacement. We also defined a segment-level rate adaptation algorithm which uses download aborts to enforce CoS differentiation across distributed independent clients. The segment-level abstraction more accurately models application-network interactions and highlights the difference between segment-level and packet-level time scales. Our segment-level CoS enforcement techniques provide a foundation for creating scalable managed OTT video delivery services

Distribuição de vídeo para grupos de utilizadores em redes móveis heterogéneas19

The evolutions veri ed in mobile devices capabilities (storage capacity, screen resolution, processor, etc.) over the last years led to a signi cant change in mobile user behavior, with the consumption and creation of multimedia content becoming more common, in particular video tra c. Consequently, mobile operator networks, despite being the target of architectural evolutions and improvements over several parameters (such as capacity, transmission and reception performance, amongst others), also increasingly become more frequently challenged by performance aspects associated to the nature of video tra c, whether by the demanding requirements associated to that service, or by its volume increase in such networks. This Thesis proposes modi cations to the mobile architecture towards a more e cient video broadcasting, de ning and developing mechanisms applicable to the network, or to the mobile terminal. Particularly, heterogeneous networks multicast IP mobility supported scenarios are focused, emphasizing their application over di erent access technologies. The suggested changes are applicable to mobile or static user scenarios, whether it performs the role of receiver or source of the video tra c. Similarly, the de ned mechanisms propose solutions targeting operators with di erent video broadcasting goals, or whose networks have di erent characteristics. The pursued methodology combined an experimental evaluation executed over physical testbeds, with the mathematical evaluation using network simulation, allowing the veri cation of its impact on the optimization of video reception in mobile terminalsA evolução veri cada nas características dos dispositivos moveis (capacidade de armazenamento, resolução do ecrã, processador, etc.) durante os últimos anos levou a uma alteração signi cativa nos comportamentos dos utilizadores, sendo agora comum o consumo e produção de conteúdos multimédia envolvendo terminais móveis, em particular o tráfego vídeo. Consequentemente, as redes de operador móvel, embora tendo também sido alvo constante de evoluções arquitecturais e melhorias em vários parâmetros (tais como capacidade, ritmo de transmissão/recepção, entre outros), vêemse cada vez mais frequentemente desa adas por aspectos de desempenho associados à natureza do tráfego de vídeo, seja pela exigência de requisitos associados a esse serviço, quer pelo aumento do volume do mesmo nesse tipo de redes. Esta Tese propôe alterações à arquitetura móvel para a disseminação de vídeo mais e ciente, de nindo e desenvolvendo mecanismos aplicáveis à rede, ou ao utilizador móvel. Em particular, são focados cenários suportados por IP multicast em redes móveis heterogéneas, isto é, com ênfase na aplicação destes mecanismos sobre diferentes tecnologias de acesso. As alterações sugeridas aplicam-se a cenários de utilizador estático ou móvel, sendo este a fonte ou receptor do tráfego vídeo. Da mesma forma, são propostas soluções tendo em vista operadores com diferentes objectivos de disseminação de vídeo, ou cujas redes têm diferentes características. A metodologia utilizada combinou a avaliação experimental em testbeds físicas com a avaliação matemática em simulações de redes, e permitiu veri car o impacto sobre a optimização da recepção de vídeo em terminais móveisPrograma Doutoral em Telecomunicaçõe

Verbesserung der Dateiverarbeitungskette in Betriebssystemen durch Nutzung der Skalierbarkeit moderner Kompressionsverfahren

Motivated by the current challenges in the field of computerized processing of multimedia information, this work contributes to the field of research on data processing and file management within computer systems. It presents novel techniques that enhance existing file- and operating systems by utilizing the scalability of modern media formats. For this purpose, the compression formats JPEG 2000 and H.264 SVC will be presented with a focus on how they achieve scalability. An analysis of the limiting hard- and software components in a computer system for the application area is presented. In particular, the restrictions of the utilized storage-devices, data interfaces and file systems are laid out and workarounds to compensate the performance bottlenecks are depicted. According to the observation that compensating the defiles requires extra efforts, new solution statements utilizing scalable media are derived and examined, subsequently. The present work reveals new concepts for managing scalable media files comprising a new rights management as well as a use-case-optimized storage technique. The rights management allows for granting access to certain parts of a file by which the scalability of the media files can be exploited in a way that users get access to various variants depending on their access rights. The use-case-optimized storage technique increases the throughput of hard disk drives when the subsequent access pattern to the media content is known a-priori. In addition, enhancements for existing data workflows are proposed by taking advantage of scalable media. Based on the Substitution Strategy, where missing data from a scalable file is compensated, a real-time capable procedure for reading files is shown. Using this strategy, image-sequences comprising a video can be shown at a given frame rate without interruptions caused by insufficient throughput of the storage device or low-speed interfaces used to connect the storage device. Adapted caching-strategies facilitate an increase of images residing in cache compared to non-scalable-variants. Additionally, a concept called Parameterizable File-Access is introduced which allows users to request a certain variant of a scalable file directly from the file system by adding side-information to a virtual file name.Motiviert durch die aktuellen Herausforderungen im Bereich der computergestützten Bearbeitung vom Multimediadaten, leistet die vorliegende Arbeit einen Beitrag zum Forschungsgebiet der Datenverarbeitung und Dateiverwaltung innerhalb von Computersystemen durch neuartige Verfahren zur Nutzung skalierbarer Medien unter Verwendung vorhandener Datei- und Betriebssysteme. Hierzu werden die Kompressionsformate JPEG 2000 und H.264 SVC vorgestellt und gezeigt, wie die Eigenschaft der Skalierbarkeit innerhalb der verschiedenen Verfahren erreicht wird. Es folgt eine Analyse der limitierenden Hard- und Softwarekomponenten in einem Computersystem für das o.g. Einsatzgebiet. Ausgehend vom hohen Aufwand zur Kompensation der Leistungsengpässe werden anschließend neue Lösungsansätze unter Nutzung skalierbarer Medienformate abgeleitet, die nachfolgend untersucht werden. Die vorliegende Arbeit zeigt hierzu neue Konzepte zur Verwaltung skalierbarer Mediendaten, die durch ein neues Rechtemanagement sowie durch eine speicheradaptive Ablagestrategie abgedeckt werden. Das Rechtemanagement erlaubt die Vergabe von Zugriffsrechten auf verschiedene Abschnitte einer Datei, wodurch die Skalierbarkeit der Medien derart abgebildet werden kann, dass verschiedene Benutzer unterschiedliche Varianten einer Datei angezeigt bekommen. Die speicheradaptive Ablagestrategie erreicht Durchsatzsteigerungen der verwendeten Datenträger, wenn das spätere Zugriffsverhalten auf die gespeicherten Medien vorab bekannt ist. Weiter werden Verbesserungen der Verarbeitungsabläufe unter Ausnutzung skalierbarer Medien gezeigt. Auf Basis der entwickelten Substitutionsmethode zur Kompensation fehlender Daten einer skalierbaren Datei wird eine echtzeitfähige Einlesestrategie vorgestellt, die unzureichende Durchsatzraten von Speichermedien bzw. langsamen Schnittstellen derart kompensieren kann, dass eine unterbrechungsfreie Ausspielung von Bildsequenzen bei einer vorgegebenen Bildwiederholrate gewährleistet werden kann. Angepasste Cache-Strategien ermöglichen eine Steigerung der im Cache vorhaltbaren Einzelbilder im Vergleich zu nicht skalierbaren Varianten. Darüber hinaus wird das Konzept eines parametrisierbaren Dateiaufrufes eingeführt, wodurch mittels Zusatzinformationen im virtuellen Dateinamen eine gewünschte Variante einer skalierbaren Datei vom Datenspeicher angefragt werden kann

Verbesserung der Dateiverarbeitungskette in Betriebssystemen durch Nutzung der Skalierbarkeit moderner Kompressionsverfahren

Motivated by the current challenges in the field of computerized processing of multimedia information, this work contributes to the field of research on data processing and file management within computer systems. It presents novel techniques that enhance existing file- and operating systems by utilizing the scalability of modern media formats. For this purpose, the compression formats JPEG 2000 and H.264 SVC will be presented with a focus on how they achieve scalability. An analysis of the limiting hard- and software components in a computer system for the application area is presented. In particular, the restrictions of the utilized storage-devices, data interfaces and file systems are laid out and workarounds to compensate the performance bottlenecks are depicted. According to the observation that compensating the defiles requires extra efforts, new solution statements utilizing scalable media are derived and examined, subsequently. The present work reveals new concepts for managing scalable media files comprising a new rights management as well as a use-case-optimized storage technique. The rights management allows for granting access to certain parts of a file by which the scalability of the media files can be exploited in a way that users get access to various variants depending on their access rights. The use-case-optimized storage technique increases the throughput of hard disk drives when the subsequent access pattern to the media content is known a-priori. In addition, enhancements for existing data workflows are proposed by taking advantage of scalable media. Based on the Substitution Strategy, where missing data from a scalable file is compensated, a real-time capable procedure for reading files is shown. Using this strategy, image-sequences comprising a video can be shown at a given frame rate without interruptions caused by insufficient throughput of the storage device or low-speed interfaces used to connect the storage device. Adapted caching-strategies facilitate an increase of images residing in cache compared to non-scalable-variants. Additionally, a concept called Parameterizable File-Access is introduced which allows users to request a certain variant of a scalable file directly from the file system by adding side-information to a virtual file name.Motiviert durch die aktuellen Herausforderungen im Bereich der computergestützten Bearbeitung vom Multimediadaten, leistet die vorliegende Arbeit einen Beitrag zum Forschungsgebiet der Datenverarbeitung und Dateiverwaltung innerhalb von Computersystemen durch neuartige Verfahren zur Nutzung skalierbarer Medien unter Verwendung vorhandener Datei- und Betriebssysteme. Hierzu werden die Kompressionsformate JPEG 2000 und H.264 SVC vorgestellt und gezeigt, wie die Eigenschaft der Skalierbarkeit innerhalb der verschiedenen Verfahren erreicht wird. Es folgt eine Analyse der limitierenden Hard- und Softwarekomponenten in einem Computersystem für das o.g. Einsatzgebiet. Ausgehend vom hohen Aufwand zur Kompensation der Leistungsengpässe werden anschließend neue Lösungsansätze unter Nutzung skalierbarer Medienformate abgeleitet, die nachfolgend untersucht werden. Die vorliegende Arbeit zeigt hierzu neue Konzepte zur Verwaltung skalierbarer Mediendaten, die durch ein neues Rechtemanagement sowie durch eine speicheradaptive Ablagestrategie abgedeckt werden. Das Rechtemanagement erlaubt die Vergabe von Zugriffsrechten auf verschiedene Abschnitte einer Datei, wodurch die Skalierbarkeit der Medien derart abgebildet werden kann, dass verschiedene Benutzer unterschiedliche Varianten einer Datei angezeigt bekommen. Die speicheradaptive Ablagestrategie erreicht Durchsatzsteigerungen der verwendeten Datenträger, wenn das spätere Zugriffsverhalten auf die gespeicherten Medien vorab bekannt ist. Weiter werden Verbesserungen der Verarbeitungsabläufe unter Ausnutzung skalierbarer Medien gezeigt. Auf Basis der entwickelten Substitutionsmethode zur Kompensation fehlender Daten einer skalierbaren Datei wird eine echtzeitfähige Einlesestrategie vorgestellt, die unzureichende Durchsatzraten von Speichermedien bzw. langsamen Schnittstellen derart kompensieren kann, dass eine unterbrechungsfreie Ausspielung von Bildsequenzen bei einer vorgegebenen Bildwiederholrate gewährleistet werden kann. Angepasste Cache-Strategien ermöglichen eine Steigerung der im Cache vorhaltbaren Einzelbilder im Vergleich zu nicht skalierbaren Varianten. Darüber hinaus wird das Konzept eines parametrisierbaren Dateiaufrufes eingeführt, wodurch mittels Zusatzinformationen im virtuellen Dateinamen eine gewünschte Variante einer skalierbaren Datei vom Datenspeicher angefragt werden kann

Adaptive header compression techniques for mobile multimedia networks

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

FLOSSTV Free, Libre, Open Source Software (FLOSS) within participatory 'TV hacking' Media and Arts Practices

This research operates in the context of a European political discourse, where the main concern is counter­cultural approaches to non­ mandatory collaboration and contractual agreements. FLOSSTV (Free, Libre, Open Source Software TV) covers a broad range of practices, from television via documentary up to media arts productions. This thesis documents the endeavour to formulate a policy for FLOSS culture. FLOSSTV studies the impact of new intellectual property legislation on media production, as well as conceptions and applications of collective authorship and alternative licensing schemes. FLOSSTV sets out to explore methods that can facilitate media and arts practitioners wishing to engage in collaborative media productions. The thesis sets out to investigate the theories and histories of collaborative media and arts productions in order to set the ground for an exploration of the tools, technologies and aesthetics of such collaborations. The FLOSSTV thesis proposes a set of contracts and policies that allow for such collaborations to develop. It is through practice that this research explores FLOSS culture, including its methods, licensing schemes and technologies. In order to focus the research within the field of FLOSSTV I initiated the practice ­based Deptford.TV pilot project as the central research experiment for the FLOSSTV thesis. DVD ONE contains a series of films produced collaboratively for Deptford.TV that express the characteristics and contractual arrangements of FLOSS culture. Deptford.TV is an online audiovisual database primarily collecting media assets around the Deptford area, in South­East London, UK. Deptford.TV functions as an open, collaborative platform that allows artists, film­makers, researchers and participants of the local workshops in and around Deptford, and also beyond Deptford, to store, share, re­edit and redistribute their footage and projects. The open and collaborative nature of the Deptford.TV project demonstrates a form of shared media practice in two ways: audiences become producers by submitting their own footage, and the database enables the contributors to interact with each other. Through my practice­lead research project Deptford.TV I argue that, by supporting collaborative methods and practices, FLOSS (Free, Libre, Open Source Software) can empower media and arts practitioners to collaborate in production and distribution processes of media and arts practices

XXIII Congreso Argentino de Ciencias de la Computación - CACIC 2017 : Libro de actas

Trabajos presentados en el XXIII Congreso Argentino de Ciencias de la Computación (CACIC), celebrado en la ciudad de La Plata los días 9 al 13 de octubre de 2017, organizado por la Red de Universidades con Carreras en Informática (RedUNCI) y la Facultad de Informática de la Universidad Nacional de La Plata (UNLP).Red de Universidades con Carreras en Informática (RedUNCI