1. W3C Finland Seminar: Semantic Web & Web Services© Kimmo RaatikainenMay 6, 2003 XML in Wireless World Kimmo Raatikainen University of Helsinki, Department of Computer Science Nokia Research Center, Software Technology Laboratory Helsinki Institute for Information Technology kimmo.raatikainen@{cs.helsinki.fi,nokia.com,hiit.fi} http://www.cs.helsinki.fi/Kimmo.Raatikainen/

2. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen2 Presentation Outline Current dilemma – where the problems are Future applications – the role of XML XML usage –RDF –CC/PP –UAProf SOAP –Current situation –Possible improvements

3. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen3 TCP-HTTP-XML Dilemma Baseline TCP behaves poorly on transmission paths containing both wireless and wired links –promising progress in IETF: RFC 3481 HTTP is one of the best examples of using TCP capabilities in an extremely inefficient manner –some improvements proposed: Mowgli, WebExpress, lWML, HDML, CHTML, mLinks XML is verbose and expensive to process –why human readable presentation on wire if humans are not reading raw messages? –WAP Binary XML does not help a lot – only TAGs tokenized –Flexible binary presentation format needed

4. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen4 Future Applications Properties: –Personalized –Adaptive –Context-aware A lot of data–describing user preferences, device capabilities, application requirements, etc.–used to adjust application behaviour XML used (or planned to be used) present this information For Web Services XML also used as “wire format” of RPC – that is SOAP

5. W3C Finland Seminar: Semantic Web & Web Services© Kimmo RaatikainenMay 6, 2003 XML Usage

6. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen6 RDF: Resource Description Framework The RDF specifications provide a lightweight ontology system to support the exchange of knowledge The foundation of RDF is a model for representing named properties and property values. RDF properties may be thought of as attributes of resources and in this sense correspond to traditional attribute-value pairs. RDF properties also represent relationships between resources –RDF Schemas — which are themselves instances of RDF data models — are ER diagrams.

7. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen7 RDF Specification Suite Resource Description Framework (RDF) Model and Syntax Specification RDF Vocabulary Description Language 1.0: RDF Schema RDF Model Theory RDF/XML Syntax Specification (Revised) RDF Test Cases RDF Primer Resource Description Framework (RDF): Concepts and Abstract Data Model Available thru: http://www.w3.org/RDF/

8. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen8 Device Independence Architecture

9. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen9 DI Publications Device Independence Working Group –Requirements For Core Presentation Attributes –Delivery Context Overview for Device Independence –Authoring Challenges for Device Independence –Device Independence Principles CC/PP Working Group –CC/PP: Strcuture and Vocabularies –CC/PP Implementors Guide: Privacy and Protocols –CC/PP Implementors Guide: Harmonization with Existing Vocabularies and Content Transformation Heuristics Available thru: http://www.w3.org/2001/di/

10. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen10 CC/PP: Composite Capabilities/ Preference Profile CC/PP is based on the XML serialized Resource Description Framework (RDF) This profile structure is vocabulary independent and allows the use of one or more vocabularies which may be optionally described using RDF Schema. CC/PP allows for the dynamic composition of a delivery context profile from fragments of capability information that may be distributed among multiple repositories on the web.

11. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen11 CC/PP The draft CC/PP recommendation suggests a possible vocabulary –does not define a protocol for exchanging profiles –does not specify how the profile should be used within any mechanism for content adaptation. CC/PP is the preferred approach to communicating delivery context information between clients, intermediaries and origin servers. Work on its definition and implementation is continuing both in W3C and in the Java Community Process [JSR188].

12. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen12 UAProf The Open Mobile Alliance has defined a User Agent Profile –implementation of CC/PP for WAP-enabled mobile terminals Transport of UAProf information using the HTTP Extension Framework –WAP 2.0 defines an extension of HTTP 1.1 as an Internet protocol (W-HTTP) –WAP also defines a profile vocabulary 3GPP Mobile Execution Environment (MExE) group has adopted the UAProf - CC/PP framework for MExE terminals. FIPA Device Ontology Specification

13. W3C Finland Seminar: Semantic Web & Web Services© Kimmo RaatikainenMay 6, 2003 SOAP

14. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen14 SOAP Deliverables XML Protocol Requirements XML Protocol Usage Scenarios XML Protocol Abstract Model SOAP Version 1.2 Part 1: Messaging Framework SOAP Version 1.2 Part 2: Adjuncts SOAP Version 1.2 Part 0: Primer SOAP Version 1.2 Specification Assertions and Test Collection SOAP 1.2 Attachment Feature SOAP Version 1.2 Email Binding SOAP Version 1.2 Message Normalization "application/soap+xml" media type

15. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen15 XML Protocol Framework SOAP Binding Underlying protocol Transport Message Exchange Context Environ ment Network Properties (including exchanged messages) Properties (including exchanged messages) Per-message exchange context carrying exchange (instance) specific properties Environment containing per-Node properties. Externally observable and changeable

16. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen16 SOAP Protocol Binding Framework SOAP enables exchange of SOAP messages using a variety of underlying protocols. The SOAP Protocol Binding Framework provides general rules for the specification of protocol bindings –The HTTP binding illustrates the specification of a binding. –Additional bindings can be created by specifications that conform to the binding framework The binding framework does NOT require that every binding use the XML 1.0 serialization as the "on the wire" representation of the XML infoset; –compressed, encrypted, fragmented representations and so on can be used if appropriate. –A binding, if using XML 1.0 serialization of the XML infoset, MAY mandate that a particular character encoding or set of encodings be used.

17. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen17 SOAP binding specification Declares the features provided by a binding. Describes how the services of the underlying protocol are used to transmit SOAP message infosets. Describes how the services of the underlying protocol are used to honor the contract formed by the features supported by that binding. Describes the handling of all potential failures that can be anticipated within the binding. Defines the requirements for building a conformant implementation of the binding being specified.

18. W3C Finland Seminar – Espoo, May 6, 2003Kimmo Raatikainen18 Some Measurement Results