Improving efficiency and enhancing utilizability of media-on-demand systems [Elektronische Ressource] / von Boris Nikolaus

Nikolaus Gihr

Sujets

• Informatik

Informations

• Publié par: universitat_bremen
• Publié le: 01 janvier 2008
• Nombre de lectures: 17
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Improving Efficiency and
Enhancing Utilizability of
Media-on-Demand Systems
DemFachbereich03—Mathematik/Informatik —
der Universität Bremen
zur Erlangung des akademischen Grades eines
Doktor-Ingenieurs (Dr.-Ing.)
eingereichte
Dissertation
von
Dipl.-Inf. Boris Nikolaus
aus
Berlin, Deutschland
Datum der Einreichung: 2008/07/01
Referent: Prof. Dr. Ute Bormann, Universität Bremen
Koreferent: Prof. Dr. Jörg Ott, Helsinki University of Technology
Tag der mündlichen Prüfung: 2008/09/05Abstract
Nikolaus, Boris:
Improving Efficiency and Enhancing Utilizability of Media-on-Demand Systems
Media-on-demand is a method which extends traditional media transmissions by an important ser-
vice: While consumers depend on the schedule of broadcasting organizations in case of traditional
media transmissions like television or radio, they are granted the possibility to select a media
stream from the offer of the provider and request it at arbitrary time in case of media-on-demand.
Certainly, this surplus service creates additional requirements to the sender and receiver sys-
tems and to the network between these systems, especially when a large number of receiver
systems are simultaneously active. To keep these requirements low, many advanced media-on-
demand systems and transmission techniques have been proposed in recent years. Besides of
following different approaches, these systems differ by their goals and focus, their efficiency and
utilizability, and each of them brings its own advantages and drawbacks with it.
The aim of the present thesis is to improve the efficiency of media-on-demand transmissions
and to enhance the utilizability of media-on-demand systems. To achieve these goals, many media-
on-demand systems have been analyzed, and from the gained experience and knowledge, a new
and improved system has been developed. This new system distinguishes itself from existing
systems by incorporating nearly any of the advantages and extensions of the other systems while
operating at an efficiency near to the theoretical optimum and by providing a high flexibility and
robustness at the same time. To prove the practical benefit of the proposed system in real en-
vironments, an embedding into an existing real-time transport protocol has been proposed and a
comparison of the cost-effectiveness opposed to traditional media-on-demand systems has been
provided.
Media-on-Demand, Video-on-Demand, Interactive TV, Media StreamingZusammenfassung
Nikolaus, Boris:
Improving Efficiency and Enhancing Utilizability of Media-on-Demand Systems
Steigerung der Effizienz und Verbesserung der Einsetzbarkeit von Media-on-Demand-Systemen
Media-on-Demand ist ein Verfahren, das traditionelle Medienübertragungen um einen wichtigen
Dienst erweitert: Während bei traditionellen Medienübertragungen wie z. B. Fernsehen und Ra-
dio die Sendeanstalten das Programm festlegen, ist es dem Konsument bei Media-on-Demand
möglich, einen Medienstrom aus dem Angebot des Anbieters auszuwählen und zu beliebiger Zeit
anzufordern.
Dieser Mehrwert erzeugt natürlich zusätzliche Anforderungen an die Sende- und Empfangs-
systeme und an das Netzwerk zwischen diesen Systemen, insbesondere wenn eine große An-
zahl von Empfangssystemen zeitgleich aktiv sein kann. Um die Anforderungen möglichst gering
zu halten, wurden in den letzten Jahren viele hochentwickelte Media-on-Demand-Systeme und
-Übertragungstechniken vorgestellt. Neben der Verfolgung verschiedener Ansätze unterscheiden
sich diese Verfahren auch in ihren Zielsetzungen, Schwerpunkten, ihrer Effizienz sowie Einsetz-
barkeit und bringen unterschiedliche, systemimmanente Vor- und Nachteile mit sich.
Die vorliegende Arbeit hat die Zielsetzung, die Effizienz von Media-on-Demand-Übertragungen
zu steigern und die Einsetzbarkeit von Media-on-Demand-Systemen zu verbessern. Um diese Zie-
le zu erreichen, wurden eine große Anzahl bestehender Media-on-Demand-Verfahren analysiert
und mit den daraus gewonnenen Erfahrungen und Erkenntnissen ein neues, verbessertes System
entwickelt. Dieses neue System zeichnet sich dadurch aus, dass es nahezu alle Vorteile und Er-
weiterungen der bestehenden Verfahren in sich vereint, eine Effizienz nahe dem theoretischen
Optimum besitzt und zugleich äußerst flexibel und robust in seinem Einsatz ist. Um den prakti-
schen Nutzen des Systems in realen Einsatzgebieten zu belegen, wurde zusätzlich eine Einbettung
in ein existierendes Echtzeittransportprotokoll vorgestellt und in einem Kostenvergleich die wirt-
schaftliche Rentabilität der von traditionellen Media-on-Demand-Systemen gegenübergestellt.
Media-on-Demand, Video-on-Demand, interaktives Fernsehen, MedienstromübertragungAcknowledgments
This thesis is the result of the research I carried out from 1998 to 2007 on the topic of media-on-
demand. Although I am the sole author of this thesis, many people have contributed to it, to my
education and to my live, and it is my greatest pleasure to take this opportunity to thank them.
First and foremost, I would like to express my greatest gratitude to Prof. Dr.-Ing. Jörg Ott. After
receiving much guidance from him when I wrote my diploma thesis at the Technische Universität
Berlin, I am very pleased that he decided to continue attending my academic career. Although liv-
ing about 300 km apart (and since 2005 even around 1100 km), he managed to meet me countless
times (while being always available by telephone) for our innumerable and fruitful discussions
which not only brought new ideas and approaches into view but also delighted and motivated me
much to continue my work on this long and sometimes stubborn path.
Furthermore, it gives me great pleasure to thank Prof. Dr.-Ing. Ute Bormann and Prof. Dr.-
Ing. Carsten Bormann for participating in many enlightening discussions and for their organiza-
tional and professional guidance to a successful thesis.
Additionally, I would like to thank Prof. Dr.-Ing. Ute Bormann for accepting supervision of
this thesis and Prof. Dr.-Ing. Jörg Ott for taking the role of the second thesis advisor.
There is one other friend I owe special thanks: During countless meetings, I got an invaluable
help from Dipl.-Inf. Frank Tscheuschner by proofreading my publications and parts of this thesis,
making critical remarks and useful suggestions and besides this for improving my English. I
also would like to offer my thanks to Dipl.-Ing. Stefan Schwabe, Dipl.-Ing. Martina Liggesmeier,
Dipl.-Ing. Tobias Poschwatta and Dipl.-Wirtschaftsinf. (FH) Christian Zanoth for proofreading
this thesis.
Finally, I would like to thank my parents and especially my wife for their patience, their encour-
agement and all the support they gave me to perform my researches and to successfully complete
this thesis.Contents
1 Introduction 1
1.1 Media-on-Demand ................................. 2
1.2 MotivationforMedia-on-Demand......... 4
1.3 ScopeofthisThesis................................. 7
1.4 StructureofthisThesis.... 9
2 Media-on-Demand Systems 11
2.1 Functioning and Capabilities of Media-on-Demand Systems . . ......... 12
2.2 StructureofMedia-on-DemandSystems................. 13
2.2.1 Sender-Side Components of a Media-on-Demand System ........ 15
2.2.2 Receiver-Side Components of a Meemand System........ 20
2.3 Topology of Media-on-Demand Systems . . .................... 21
2.4 Classification of Media Transmission Systems ........ 25
2.4.1 Technical Classification of Media Transmission Systems ......... 26
2.4.2 Functional Classification for Media Transmission Systems ........ 32
2.5 MediaContentandFormat............................. 37
2.5.1 StructureofMediaContent......... 38
2.5.2 ContentofMediaStreams.................... 39
2.5.3 MediaEncodings.............. 39
2.6 Summary................................ 41
3 Media Transmission Schemes 43
3.1 EfficiencyofMediaTransmisionSchemes .................... 45
3.1.1 RequestPatternforMedia-on-DemandTransmissions ..... 46
3.1.2 Minimum Required Bandwidth for Reactive Transmission Schemes . . . 48
3.1.3 Minimum Required Bandwidth for Pro-Active Transmission Schemes . . 50
3.1.4 EfficiencyGraphs.............................. 52
3.2 TraditionalMediaTransmisionSchemes..... 53vi CONTENTS
3.2.1 Single Broadcast .............................. 53
3.2.2 PersonalTapeArchive..... 54
3.2.3 VideoRentalStoresandMediaLibraries ................. 55
3.2.4 CompletePreloadingofMediaStreams....... 55
3.2.5 SummaryofTraditionalMediaTransmisionSchemes.......... 56
3.3 Reactive Media-on-Demand Transmission Schemes . .......... 57
3.3.1 Point-to-Point Transmissions .................. 57
3.3.2 Batching ........................ 59
3.3.3 Adaptive Piggy-Backing .................... 62
3.3.4 Patching................... 63
3.3.5 Taping........................ 66
3.3.6 Merging................... 69
3.3.7 Virtual Batching ........................ 71
3.3.8 Per-to-PerNetworks........... 73
3.3.9 Comparison of Reactive Transmission Schemes .............. 75
3.4 Non-SegmentingPro-ActiveTransmisionSchemes........... 78
3.4.1 Round-Robin Broadcasting................... 79
3.4.2 StaggeredBroadcasting ................ 80
3.4.3 Comparison of Non-Segmenting Pro-Active Transmission Schemes . . . 81
3.5 Size-Based Segmenting Transmission Sche