State of the Art in Enablers for Applications in Future Mobile Wireless Internet
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Soininen (ed.),Pitkänen,Väl Helsinki Institute for Information Technology HIIT, founded in 1999, is a joint research institute of University of Helsinki and Helsinki University of Technology. HIIT conducts internationally high-level strategic research in i information technology and related multi-disciplinary topics, mäki, Oksanen,Reti:Mobil especially in areas where Finnish IT industry has or may reach a significant global role. HIIT works in close co-operation with Finnish universities, research institutes, and industry, aiming to improve the contents, visibility, and impact of Finnish IT research to benefit the competitiveness and progress of the Finnish information society. HIIT also aims at creating a strong network of international partnerships with leading foreign research universities and institutions. CONTACTS STATE OF THE ART IN ENABLERS FOR APPLICATIONS WWW: http://www.hiit.fi/ Tel: +358-9-85012313; Fax: +358-9-6949768 Postal address: P.O.Box 9800, 02015 HUT, Finland IN FUTURE MOBILE WIRELESS INTERNET Visiting: High Tech Center, Tammasaarenkatu 3, Helsinki, Finland e IP R FinalReport Sasu Tarkoma, Ramya Balu, Jaakko Kangasharju, Miika Komu, Mika Kousa, Tancred Lindholm, Mikko Mäkelä, Marko Saaresto, Kristian Slavov, Kimmo Raatikainen September, 2004 HIITTechreports2003-3 HIIT Publications 2004-2 STATE OF THE ART IN ENABLERS FOR APPLICATIONS IN FUTURE MOBILE WIRELESS INTERNET Sasu Tarkoma, Ramya Balu, Jaakko Kangasharju, Miika Komu, Mika Kousa, Tancred Lindholm, Mikko Mäkelä, Marko Saaresto, Kristian Slavov, Kimmo Raatikainen Helsinki Institute for Information Technology HIIT Tammasaarenkatu 3, Helsinki, Finland P.O. BOX 9800 FI-02015 TKK, Finland http://www.hiit.fi HIIT Publications 2004-2 ISBN 951-22-7332-2 (electronic) ISSN 1458-946X (electronic) URL: http://www.hiit.fi/publications/pub_files/fc-state-of-the-art-2004.pdf Copyright © 2004 held by the authors Contents 1 Introduction 1 2 Event-based Systems 7 2.1 Introduction ........................... 7 2.2 Event Models .......................... 9 2.2.1 Events .......................... 10 2.2.2 Event Model ...................... 11 2.2.3 Routing ......................... 12 2.2.4 Content-based Routing ................ 13 2.2.5 Requirements for Mobile Computing ......... 16 2.3 Event Standards and Specifications ............. 19 2.3.1 Java Delegation Event Model ............. 19 2.3.2 Java Distributed Event Model ............. 19 2.3.3 Java Message Service ................. 20 2.3.4 CORBA Event Service ................. 25 2.3.5 CORBA Notification Service .............. 30 2.3.6 CORBA Management of Event Domains ....... 35 2.3.7 W3C DOM Events ................... 37 2.3.8 Web Services Eventing (WS-Eventing) ........ 37 2.3.9 COM+ and .NET .................... 38 2.3.10 Websphere MQ ..................... 43 2.4 Event Systems ......................... 44 2.4.1 The Cambridge Event Architecture .......... 44 2.4.2 Scalable Internet Event Notification Architecture .. 46 2.4.3 Scribe .......................... 51 2.4.4 Elvin ........................... 52 2.4.5 JEDI ........................... 55 2.4.6 ECho .......................... 58 2.4.7 JECho .......................... 58 2.4.8 Rebeca ......................... 59 2.4.9 Gryphon ......................... 60 i CONTENTS 2.4.10 STEAM ......................... 62 2.4.11 Rapide ......................... 63 2.5 Conclusions ........................... 63 3 XML Protocols 67 3.1 XML ............................... 67 3.2 Web Services .......................... 69 3.3 Protocols ............................ 71 3.3.1 History ......................... 71 3.3.2 Features ........................ 72 3.3.3 Current State ...................... 73 3.3.4 Implementations .................... 74 3.4 XML over Wireless ....................... 75 3.4.1 Problem Areas ..................... 75 3.4.2 Transfer Protocols ................... 75 3.4.3 Compression ...................... 76 3.5 Conclusions ........................... 78 4 Synchronization 81 4.1 Introduction ........................... 81 4.2 Coda ............................... 83 4.2.1 Storage and Update Model .............. 84 4.2.2 Coda as an MDIB ................... 88 4.2.3 Practical Issues ..................... 89 4.3 InterMezzo ........................... 89 4.3.1 Storage and Update Model .............. 90 4.3.2 InterMezzo as an MDIB ................ 92 4.3.3 Practical Issues ..................... 93 4.4 Bayou .............................. 93 4.4.1 Storage and Update Model .............. 94 4.4.2 Bayou as an MDIB: Practical Issues ......... 98 4.5 Key-based Routing ....................... 99 4.5.1 Plaxton-Rajaman-Richa KBR ............. 100 4.6 OceanStore ........................... 101 4.6.1 Storage and Update Model .............. 104 4.6.2 OceanStore as an MDIB ................ 106 4.6.3 Practical Issues ..................... 108 4.7 SyncML ............................. 108 4.7.1 Using SyncML in an MDIB ............... 111 4.7.2 Deployment Issues ................... 112 4.8 Synchronization Policies .................... 112 ii CONTENTS 4.9 Generic Data Reconciliation Methods ............ 114 4.10 Strategies for Conserving Bandwidth ............. 115 4.10.1 Data Compression ................... 116 4.10.2 Delta Transfers ..................... 116 4.10.3 Content Adaptation .................. 118 4.10.4 Operation Shipping ................... 118 4.11 Conclusions ........................... 119 5 Mobile Presence 121 5.1 Introduction ........................... 121 5.1.1 Concepts ........................ 121 5.1.2 Presence and Context ................. 122 5.1.3 History ......................... 122 5.1.4 Challenges ....................... 124 5.2 Existing Presence Technology ................ 127 5.2.1 Open Mobile Alliance ................. 127 5.2.2 The Parlay Group ................... 128 5.2.3 Internet Engineering Task Force ........... 129 5.2.4 Service Integrators ................... 133 5.3 Discussion ........................... 134 5.3.1 Prototypes ....................... 134 5.3.2 Fundamental Trade-offs ................ 136 5.3.3 Online Identity ..................... 137 5.3.4 Embedded Presence ................. 140 5.3.5 Related Research ................... 140 5.4 Conclusions ........................... 141 6 Host Identity Protocol 143 6.1 Introduction ........................... 143 6.2 Background ........................... 143 6.3 Architecture Overview ..................... 146 6.3.1 Host Identity ...................... 146 6.3.2 Other Representations of Host Identity in HIP .... 147 6.3.3 Base Exchange .................... 147 6.3.4 Security and Privacy .................. 148 6.3.5 Multihoming ....................... 148 6.3.6 Mobility ......................... 148 6.3.7 Rendezvous Server .................. 150 6.3.8 Native Application Programming Interface ...... 150 6.3.9 Advantages and Disadvantages ........... 151 6.4 Related Work .......................... 153 iii CONTENTS 6.4.1 Mobile IPv6 ....................... 153 6.4.2 MobIKE ......................... 153 6.4.3 SCTP .......................... 153 6.5 Current Status ......................... 154 6.5.1 Standardization Status ................. 154 6.5.2 HIP Projects ...................... 155 6.5.3 Meetings ........................ 155 6.6 Conclusions ........................... 162 7 SIP and Events 163 7.1 Introduction ........................... 163 7.2 Overview of SIP ........................ 164 7.2.1 Session Initiation Protocol (SIP) ........... 164 7.2.2 Terminologies in SIP .................. 164 7.2.3 Steps Involved in Establishing a Session ....... 166 7.2.4 Methods and Response in a SIP Transaction .... 166 7.2.5 Features of SIP ..................... 168 7.3 SIP Research Areas ...................... 169 7.3.1 Active Research Topics ................ 169 7.3.2 Working Groups in IETF ................ 171 7.3.3 Work in the Third Generation Partnership Project on SIP ........................... 172 7.4 SIP and Event Architectures .................. 174 7.4.1 An Introduction to Events in Distributed Systems .. 175 7.4.2 General Requirements of an Event Framework ... 175 7.4.3 Design Patterns for Event Architectures ....... 176 7.4.4 SIP Event Notification ................. 176 7.4.5 CORBA Notification Service .............. 179 7.4.6 JINI Event Architecture ................ 180 7.4.7 GRID SOAP Event Systems ............. 180 7.4.8 Comparison between SIP,CORBA, GRID SOAP,and JINI Events ....................... 180 7.5 SIP and Java .......................... 181 7.5.1 JSIP — A Prototype Implementation of SIP Extensions181 7.5.2 SIP and JAIN ...................... 181 7.5.3 SIP for J2ME ...................... 182 7.5.4 SIP Servlets ...................... 182 7.5.5 Interworking of Various Java APIs with SIP ..... 182 7.5.6 Open Source SIP Implementations .......... 183 7.6 Related Work .......................... 184 7.6.1 Medical Event-based Monitoring System ....... 184 iv CONTENTS 7.6.2 Application of SIP to Ubiquitous Computing ..... 184 7.6.3 SIP for Emergency Systems ............. 185 7.6.4 SIP Extensions for Communicating with Networked Appliances ....................... 185 7.7 Summary ............................ 186 8 Context Modeling 187 8.1 Introduction ........................... 187 8.2 Requirements for Context Representation .......... 189 8.3 Classification of Context Information ............. 190 8.4 Ontologies ........................... 191 8.4.1 CC/PP .......................... 193 8.4.2 Device Independence Working Group ........ 193 8.4.3 RDF ........................... 194 8.4.4 OWL Web