Towards a Wireless Agent Markup Core Version March

Towards a Wireless Agent Markup Core Version: March 6, 2000 Prepared for: Dagstuhl Seminar 00121, Semantics for the Web March 19 -24, 2000 Harold Boley DFKI Gmb. H

Wireless/Mobile Web Access • Web access via mobile phones etc. , using WAP • WAP (Wireless Application Protocol): – Layered end-to-end communication protocol – Application environment based on a browser • WAP Forum (industry association) predicts: – 10's of millions of WAP-browser-enabled products in consumer hands by the end of 2000 • WML (Wireless Markup Language) – Specifies content and user interface for mobile phones, based on XML

virtual meeting space access by mobile phone e is entered via heterogeneous devices e WAP Use at DFKI: Magic Lounge Project access by PDA

Using Heterogeneous Devices to Plan a Joint Travel - A Case Study Provide the user with cartographic information in a way that suits the available communication channels of the access device Enable joint interactions between users on displayed material PDA PC ML server mobile phone with LCD display Peter moves along Bahnhofstrasse

Translate a Complex Marking from the PC View to the Mobile Phone Approach: - sequentialize complex markings: User of mobile phone can follow a marked route by browsing through the individual segments Server

One World: W 3 C and WAP Forum Formal Liaison Relationship • ". . . want to avoid unnecessary divergence between the standards of the two organizations. " (Greg Williams, Board Chairman WAP Forum) • ". . . device-independence is a critical piece. " ". . . work towards the seamless integration of mobile devices and the Web. " (Tim Berners-Lee, Director W 3 C) • Wireless devices to participate as full peers in the Web, largely through the incorporation of WML features into XHTML

Cooperative Work Items W 3 C WAP Forum Device-Independent Web • Joint work on XHTML • Compatibility with SMIL (Synchronized Multimedia Integration Language) • Ensuring user control over privacy information • CC/PP (universal device profiling protocol based on W 3 C RDF Metadata)

WML: Wireless Markup Language • Text presentation/layout and image support using formatting/layout commands • Deck-of-cards organization for documents • Explicit navigation between cards and decks • Tasks such as (implicit) navigation associated with events • User input, e. g. for orders in E-commerce • String parameterization and state management using "variables"

Problems for Agent Markup in WML • P 1: XML DTD formalizes only WML syntax • P 2: WML semantics quite complex/procedural • P 3: Mixing of presentation and representation • P 4: Not an open standard

P 1+P 2 Solution Approach: Three-Layer Architecture Syntax: can define Semantics: Agent Core can be reduced to XML defines WML will implement XHTML Basic can describe RDF, DAML, . . . can describe

P 3 Solution: Separating Presentation and Representation using Ontologies • Ontologies represent semantic essence • Separate ontology 'decks' – easier to maintain – save transmission cost – sharable among several applications • Many presentations can access and transform one representation (cf. stylesheets)

Example for the Separation WML option groups (for "Scandinavia" and "Europe") factored out WML Reference Example [38. ]: Presentation:

Select a country: Representation: Denmark Finland Scandinavia Norway Sweden Denmark Finland Norway France Sweden Germany Italy Spain Europe

P 4 Solution Approach: Towards an Open Agent Core Ontology • Agent, AICommerce, Onto. Commerce projects (e. g. at DFKI) • Upper ontologies with middle-ontology plugins and lower-ontology access • Agent (brokering) ontologies – Wiederhold Mediators, Ontobroker, . . . – KQML, FIPA, LARKS, DAML , . . . Core ontology to uniformly formalize - data (cf. above example) - metadata - capability advertisements for both buyers and sellers, based on W 3 C standards, e. g. RDF, and the WAP Forum standard WML

Top-level of Agent Core Ontology • Communication (e. g. Buy vs. Sell) • Content – Process (translation, flight) vs. Product (lexicon, plane) • Description – Capability ads (LARKS: Process) vs. metadata (Dublin Core: Product) • Input/Output Constraints (no Output: Sink; no Input: Product) • Side-effects (operation: Process; drug: Product), Resources, Cost • Superordinated, Subordinated, Coordinated Processes/Products – Information (recipe, news) vs. Matter (meal, paper) – Blueprint (plan, patent) vs. Exemplar (execution, license)

Conclusions • Device-independent standards are needed for the Web integration of mobile phones etc. • The constraints of mobile devices can trigger simpler semantic cores for markup languages • Agent markup in WML and related WAP uses require a revised wireless standard • A WML-successor language can accommodate agent semantics via ontologies for data as well as metadata and capability advertisements