Towards a Wireless Agent Markup Core

1
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

2
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 interfaces for mobile
  phones, based on XML

3
Sample WAP Use at DFKI The Magic Lounge Project
Magic Lounge is entered via heterogeneous devices
virtual meeting space
4
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
mobile phone with LCD display
Peter moves along Bahnhofstrasse
5
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
6
One World W3C and WAP ForumFormal 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

7
Cooperative Work Items
WAP Forum
W3C

• 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 W3C RDF Metadata)

Device-Independent Web
8
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"

9
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

10
P1P2 Solution ApproachThree-Layer Architecture
Syntax
Semantics
Agent Core
can define
can describe
can be reduced to
can de- scribe
defines
WML
XML
RDF, DAML, ...
will implement
can describe
defines
XHTML Basic
11
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)

12
Example for the Separation
WML option groups (for "Scandinavia" and
"Europe") factored out
13
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, ...
• KQML, FIPA, LARKS, DAML , ...

14
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 (operationProcess drugProduct),
  Resources, Cost
• Superordinated, Subordinated, Coordinated
  Processes/Products
• Information (recipe, news) vs. Matter (meal,
  paper)
• Blueprint (plan, patent) vs. Exemplar (execution,
  license)

15
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