XMPP-based Media Sharing for Mobile Collaboration with Android Phones

125 Pages·2009·3.57 MB·English

by  Benjamin Söllner

Technische Universit¨at Dresden
Fakult¨at Informatik
Institut fu¨r Systemarchitektur
Prof. Dr. rer. net. habil. Dr. h. c. Alexander Schill
Großer Beleg
XMPP-based Media Sharing for Mobile
Collaboration with Android Phones
Benjamin S¨ollner
born November 2, 1986 in Plauen, Germany
[email protected]
October 29, 2009
Advisor: Dr.-Ing. Daniel Schuster
[email protected]

Selbstst¨andigkeitserkl¨arung
Hiermit erkl¨are ich, die vorliegende Studienarbeit zum Thema
XMPP-based Media Sharing for Mobile Collaboration with Android Phones
selbstst¨andigundausschließlichunterVerwendungderimQuellenverzeichnisaufgefu¨hrten
Literatur- und sonstigen Informationsquellen verfasst zu haben.
Dresden, den 30. Oktober 2009
Unterschrift
iii

Acknowledgements
I would like to thank the staff members of the Mobilis team for their valuable guidance
and helpful input concerning both the theoretical as well as the practical part of this
work. This includes Maximilian Walther, Thomas Springer and in particular my thesis
supervisor Daniel Schuster, who motivated me by showing great interest into my ideas
and always provided valuable feedback, especially concerning the practice of academic
writing which I was fairly new to.
Thanks go also to the my student collegues who worked on other aspects of the Mo-
bilis project in parallel to or before this thesis: Istv´an Koren, Dirk Hering, Christopher
Friedrich, Jacobo Eduardo Miranda and Lukas Vierhaus. I am thankful for the passionate
atmosphere in which we shared knowledge, feedback and hints about each others area and
I enjoyed the illuminating conversations and inspirations we had. I also thank my student
collegues from student lab INF/3074 for the creative and social working environment.
I finally owe my family a big debt of gratitude. Ich danke euch vielmals fu¨r die al-
lzeitliche Unterstu¨tzung meiner Studienpl¨ane, speziell aber fu¨r Hilfe und Ruhe in den
letzten hektischen Tagen, in denen ich diese Arbeit fertiggestellt habe.
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Abstract
With the recent tremendous innovation on the mobile handset, network and operating
system market, the use of mobile phones as content creation and content sharing device
have become commonplace. Although bluetooth, MMS and email obviously seem out-
dated in the social cloud the “Web 2.0” creates, neither the academic nor the economic
world has developed an open media sharing protocol committed to collaborative work and
adapted to a mobile environment.
This thesis has been created within the Mobilis project as a subproject called“Mobilis
Media”. Mobilis is a project developing a service platform for collaborative work with
Android phones. Mobilis chose XMPP, the Extensible Messaging and Presence Protocol,
as a collaborative protocol. Besides this document, a client and a server prototype was
developed which fits into the Mobilis architecture.
The thesis starts by motivating the need of a mobile media sharing platform and by
introducing a user scenario of travel picture sharing. It then examines several file transfer
technologies, both media sharing technologies used within XMPP itself (SI File Transfer
and Jingle) and second-stack technologies (WebDAV, Atom Publishing Protocol, Google
WaveFederationProtocol). Afterwards, relatedworkisevaluatedandrequirementstothe
media sharing platform as well as the mobile client are settled. Moving on, a concrete file
sharing technology is chosen and the XMPP interface of the media sharing platform using
it is described as a custom extension to the XMPP protocol. Subsequently, the structure
oftheMobilisplatformispresentedandhowMobilisMediafitsintoit. Systemboundaries
and extension points for later projects are outlined. Some aspects of the internal structure
andsomeimplementationalconsiderationsoftheMobilisMediaprototypearehighlighted.
Finally, the presented implementation is evaluated qualitatively and quantitatively and a
prospect for future work is given.
Keywords mobile collaboration, services, mobile framework, media sharing, content
sharing, metadata, repository, multidimensional, cube, hypercube, database, social net-
works, Hibernate, Android, XMPP, Jingle, SI File Transfer, Publishing Stream Initiation
Requests, WebDAV, APP, Google Wave
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Contents
1. Introduction 1
1.1. The Mobilis Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2. User Scenario: Travel Picture Sharing . . . . . . . . . . . . . . . . . . . . . 2
1.3. Structure of this Thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Foundations 3
2.1. The XMPP Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1. Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.2. Presence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.3. Info/Query . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2. The XMPP Extension Protocols . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2.1. SI File Transfers with Published Stream Initiation Requests . . . . 8
2.2.2. Jingle – An XMPP Signalling Protocol . . . . . . . . . . . . . . . . 13
2.2.3. Jingle Transport Method Specifications . . . . . . . . . . . . . . . . 15
2.2.4. Jingle Application Format Specifications . . . . . . . . . . . . . . . 15
2.2.5. File transfers and XML Streams using Jingle . . . . . . . . . . . . . 16
2.2.6. Further XEPs concerning Jingle . . . . . . . . . . . . . . . . . . . . 17
2.3. Second-Stack Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.3.1. WebDAV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.3.2. Atom Publishing Protocol . . . . . . . . . . . . . . . . . . . . . . . 18
2.4. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3. Related Work 21
3.1. Belimpasakis et al. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.2. Tolvanen et al. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.3. Matuszewski et al. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.4. Risto Sarvas et al. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.5. Android Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.6. Google Wave Attachments (Google Wave Federation Protocol) . . . . . . . 27
3.7. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4. Requirements Analysis 31
4.1. Functional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.2. Device Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.3. Non Functional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.4. Human Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
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Contents
5. Conceptual Design 37
5.1. Finding an XMPP-based File Transfer Protocol . . . . . . . . . . . . . . . 37
5.1.1. SI File Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.1.2. One-to-one File Transfers . . . . . . . . . . . . . . . . . . . . . . . 38
5.1.3. One-to-many File Transfers . . . . . . . . . . . . . . . . . . . . . . 38
5.2. The Cube Media Repository . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.3. Breaking down the Architecture . . . . . . . . . . . . . . . . . . . . . . . . 39
5.3.1. Decomposition into Entities . . . . . . . . . . . . . . . . . . . . . . 39
5.3.2. Decomposition regarding the Mobilis Architecture . . . . . . . . . . 40
5.4. Service Primitives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
5.4.1. Custom IQs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
5.4.2. Service Discovery & Register / Unregister Service Pimitive . . . . . 45
5.4.3. Browsing Service Pimitive . . . . . . . . . . . . . . . . . . . . . . . 48
5.4.4. Download Service Pimitive . . . . . . . . . . . . . . . . . . . . . . . 49
5.4.5. Upload/Replacing Service Primitive . . . . . . . . . . . . . . . . . . 51
5.4.6. Deletion Service Primitive . . . . . . . . . . . . . . . . . . . . . . . 54
5.5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
6. Implementation Considerations 57
6.1. The Mobilis Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
6.2. Reuse of the XMPP layer using XMPPBeans . . . . . . . . . . . . . . . . . 59
6.3. Mobilis Media as a Mobilis Project . . . . . . . . . . . . . . . . . . . . . . 60
6.3.1. Server Prototype . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
6.3.2. Client Prototype . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
6.4. The Mobilis Media Server Prototype . . . . . . . . . . . . . . . . . . . . . 62
6.4.1. General Mobilis Server Class Model . . . . . . . . . . . . . . . . . . 62
6.4.2. Mobilis Media Server Class Model . . . . . . . . . . . . . . . . . . . 64
6.4.3. Mobilis Media Database Model . . . . . . . . . . . . . . . . . . . . 66
6.5. The Mobilis Media Client Prototype . . . . . . . . . . . . . . . . . . . . . 66
6.5.1. Interprocess Communication on Android . . . . . . . . . . . . . . . 66
6.5.2. External Service: TransferService . . . . . . . . . . . . . . . . . . . 67
6.5.3. External Service: RepositoryService . . . . . . . . . . . . . . . . . . 70
6.5.4. User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
6.6. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
7. Evaluation 75
7.1. Applicability of SI File Transfer . . . . . . . . . . . . . . . . . . . . . . . . 75
7.1.1. Test Environment and Methodology . . . . . . . . . . . . . . . . . . 75
7.1.2. Measurement of Transfer Time . . . . . . . . . . . . . . . . . . . . 76
7.2. Evaluation of the Repository Architecture . . . . . . . . . . . . . . . . . . 76
7.3. Evaluation of the Implementation . . . . . . . . . . . . . . . . . . . . . . . 81
7.3.1. Server Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
7.3.2. Client Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
7.4. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
8. Prospect 87
8.1. Possible Enhancements of the Prototype . . . . . . . . . . . . . . . . . . . 87
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