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 GmbH

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

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

PDA ML server mobile phone with LCD display PC Peter moves along Bahnhofstrasse 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 Using Heterogeneous Devices to Plan a Joint Travel - A Case Study

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

One World: W3C and WAP Forum Formal Liaison RelationshipW3C 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 W3C) Wireless devices to participate as full peers in the Web, largely through the incorporation of WML features into XHTML

Cooperative Work Items Joint work on XHTMLXHTML Compatibility with SMIL (Synchronized Multimedia Integration Language)SMIL Ensuring user control over privacy information CC/PP (universal device profiling protocol based on W3C RDF Metadata)CC/PP WAP ForumW3C Device-Independent Web

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 P1: XML DTD formalizes only WML syntax P2: WML semantics quite complex/procedural P3: Mixing of presentation and representation P4: Not an open standard

P1+P2 Solution Approach: Three-Layer Architecture WML XHTML Basic Agent Core RDF, DAML,... XML Syntax:Semantics: will implement can describe defines can define can be reduced to can de- scribe can describe

P3 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 Scandinavia Denmark Finland Norway Sweden Europe France Germany Italy Spain Representation: Select a country: Presentation: Select a country: Denmark Finland Norway Sweden France Germany Italy Spain WML Reference Example [38.]:

P4 Solution Approach: Towards an Open Agent Core Ontology Agent, AICommerce, OntoCommerce projects (e.g. at DFKI) Upper ontologies with middle-ontology plugins and lower-ontology access Agent (brokering) ontologies –Wiederhold Mediators, Ontobroker,...Wiederhold Mediators Ontobroker –KQML, FIPA, LARKS, DAML,...KQMLFIPALARKS DAML Core ontology to uniformly formalize - data (cf. above example) - metadata - capability advertisements for both buyers and sellers, based on W3C standards, e.g. RDF, and the WAP Forum standard WML

Top-level of Agent Core Ontology Communication (e.g. Buy vs. Sell) Contents –Process (translation, flight) vs. Product (lexicon, plane) Descriptions –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