wireless agent-based semantic web interaction heikki helin principal researcher, phd emerging...

Wireless Agent-basedSemantic Web InteractionHeikki Helin <[email protected]>Principal Researcher, PhD

Emerging Technologies and Innovations, TeliaSonera Finland

Heikki Helin: Wireless Agent-based Semantic Web Interaction

Presentation Outline

• About TeliaSonera

• Motivation

– In which field we are playing…

– What we are trying to achieve…

• Agent-based architecture for nomadic environments

– Agents architecture for such environments

– Communication framework for wireless communication

– Ontologies for nomadic environments

• On-going (or soon-to-be-started) research projects

– National, EU/FP6

• Summary


The Nordic and Baltic leader in telecommunications

• The merger between Telia and Sonera became a reality on December 9, 2002

• Listed on the Stockholm Exchange, the Helsinki Exchange and Nasdaq Stock Market in the USA

• Net sales (pro forma) in 2003 amounted to SEK 81,772 million (EUR 9,010 million)

• The number of employees was 26,000 on December 31, 2003

– R&D personnel : ~1000

TeliaSonera


The markets of TeliaSonera International

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Motivation

• New wireless Internet services for our mobile (and fixed) customers

– Not only ”new services”, but also enhance ”old ones” to give better user experience

• And do that

– faster,

– easier,

– cheaper, ...

=> To attract new customers, but more importantly: keep the old customers (and at the same time do some academic research)


Background

• Multi-agent system implementing a middleware providing (agent-based) applications with tools for adaptation in a nomadic environment

• Nomadic environments enable new ways to access services

anywhere, at any time, and using any device

• Challenges that need to be addressed:

– Varying QoS of the wireless networks

– Limitations of mobile devices

– Contextual variability (location, time, user preferences, ...)

• Adaptation to environment is the key issue


Mobile/Wireless Environment

• Typical characteristics– Low throughput, long delays, unreliable, ...

– Variability– Disconnected mode of operation is the most common state– Different kind of (wireless) networks

• Seamless roaming will be important in the future

• Actors (agents) in nomadic environments should be aware of these issues– Context-awareness (not only location)

• Currently we are mainly considering long thin networks– GSM, HSCSD, GPRS, UMTS, ...– But not excluding WLANs, BT, LAN, xDSL, ...


Agents in Nomadic Environments

• Suitable for complex environments

– Internet is a complex environment...

– Wireless Internet is even more complex...

– Invisible Internet...

Ambient networks

Intelligent P2P Pervasive Computing

Semantic Web

Ad hoc networks

Ubiquitous Computing

Distributed Artificial Intelligence

Peer-to-peer

Ontologies

QoS


FIPA Agent Platform

DF = Directory FacilitatorAMS = Agent Management System

ACC = Agent Communication Channel


(FIPA) Nomadic Application Support

Knowlegde Sharing

Knowlegde Sharing

Controlling & monitoring Controlling & monitoring


(FIPA) Nomadic Application Support


Agent Communication Wireless World


Layered model of agent communication


Message Transport


Message Transport

• How messages are transferred between agents

• Desiderata

– Reliability

– Efficiency

– Dynamic adaptation

• Issues

– Performance problems

– Terminal mobility

– Thin clients


MTP Results – 1+1; 9600bps (300ms)

0

10000

20000

30000

40000

50000

60000

0,5kb 2kb 5kb 10kb

ms

WAP

MAMAv2

IIOP

HTTP

RMI


MTP Results – 1+1; 115200bps (300ms)

0

2000

4000

6000

8000

10000

12000

0,5kb 2kb 5kb 10kb

ms

WAP

MAMAv2

IIOP

HTTP

RMI


Message Envelope


Message Envelope

• FIPA ”specific” layer

• Defines how messages are delivered

– independent of message transport protocols

• Encoding options

– XML, Bit-efficient, IIOP/IDL, Binary-XML, Java Objects, …

• Bit-efficient encoding similar to bit-efficient ACL


Message Envelope

0

500

1000

1500

2000

2500

3000

Minimal Envelope Typical Envelope

Byt

es

Bit-Efficient

IIOP

bXML

bXML(Plain)

XML

J ava Object


ACL Layer


ACL Encoding

• Options– String (s-expression), XML, Bit-efficient

– Binary-XML (w/ special encoding tokens), Java Objects

• Bit-Efficient encoding is the most efficient– Space-efficient

– ...by definition

– Time-efficient

– much faster

– nice for every application; not only for wireless

– necessity for

– high performance applications

– highly utilized servers

– simple parser appropriate for thin clients


ACL Encoding (request conversation)

0

500

1000

1500

2000

2500

3000

Send Receive

Byt

es

Bit-efficient

bXML

bXML(Plain)

String

String (deflate)

XML

Object


ACL Encoding

0

2000

4000

6000

8000

10000

12000

14000

16000

One message 10 Messages

Byt

es

Bit-efficient

bXML

bXML(Plain)

String

String (deflate)

XML

Object


Content Language Layer


Content Languages

• FIPA-SL

– All-purpose content language

– S-expression (w/ deflate), XML, Binary-XML (w/ special tokens)

• FIPA-CCL

– Language for constraint satisfaction problems

– XML & Binary-XML

• Results similar to those of message envelope and ACL


Conversation Layer


Conversation Layer

• Optimizing/modifying existing conversation protocols?

• Developing new conversation protocols?

• Selecting conversation protocol based on current environment

– low bandwidth simple protocol

not so good end result

– more bandwidth more complicated protocol

better end result


Ontologies in Wireless World


Ontologies

• An ontology is an explicit description of a domain:– Concepts

– “Wireless network”, “GSM”, “GPRS”, …

– Properties and attributes of concepts– Each “Network” will have “Operator”, “Location”, “Properties”, …– Every “IEEE802.11a” is a “WLAN”

– Constraints on properties and attributes– The name of an Operator is a string– GSM network code consist of CountryCode and NetworkID

– Individuals (often, but not always)– The GSM network operated by TeliaSonera in Finland

• An ontology defines – a common vocabulary– a shared understanding


Can’t we just use XML?

–

– –

– – – – – – – – –

For machines, a typical web page looks like this:


XML Helps...

<name>

–

</name><address>

– –

</address><cv>

– – – – – – – – –

</cv>

XML allows “meaningful tags” to be added to parts of the text


XML ≠ Machine Accessible Meaning

<>

–

<><>

– –

<><>

– – – – – – – – –

<>

To machines, the tags looks like this…


Web Ontology Languages

• Ontologies have been active research area for a long time

• Web ontology languages

– Provide ”web-friendly” representation language

– Typically based on RDF Schema

• OWL is currently W3C Recommendation


Web Ontology Languages (cont.)

• XML is not enough– Ontological modeling primitives missing

• RDF/RDFS is better, but– Only a weak semantic interpretation

– No inference model

• OWL (Web Ontology Language)– Extends RDFS

– Additional vocabulary along with a formal semantics

– More vocabulary for describing properties and classes:– Relations between classes (e.g. disjointness)

– Cardinality (e.g. "exactly one")

– Equality

– Richer typing of properties

– Characteristics of properties (e.g. symmetry)

– Enumerated classes


Need for Ontologies in Wireless World


Wireless Network Ontology - Motivation

• Machine-readable (& understandable) descriptions of networks– Currently available only for humans

• 3rd party service providers– ”Available networks at Gent?”

– ”Available networks at this Hotel?”

• Future applications– Context-aware

– ”Available networks near here?”

– “Best available network?”

– ”Available networks near my friend?”

– Any application requiring information about (wireless) networks or their properties

– Almost all wireless world applications?


Wireless Network Ontology – Overview

• Core Concepts– Network -> Wireless Network -> GSM Network -> ...

– Operator

– (Location)

– ...

• QoS Concepts– Throughput, delay, rtt, …

• Services– GSM Services

– Supplementary services, Tele services, …

– WLAN Services

– ...


Wireless Network Ontology – Core Concepts

Network

Class

WirelessNetwork

Class

WirelineNetwork

ClassdisjointWith

subClassOf

subClassOf

GSM

Class

subClassOf

GPRS

Class

subClassOf

WLAN

Class

subClassOf

IEEE802.11a

Class

IEEE802.11b

Class

subClassOf

subClassOf

UMTS

Class

subClassOf

QoSProperty

Class

Service

Class

hasService

ObjectProperty

range

hasIdentifier

ObjectProperty

Operator

Class

operatedBy

ObjectProperty

domain

rangeavailableAt

ObjectProperty

domain

Location

Classrange

qosProperties

ObjectPropertydomain domain

Identifier

Classrange

domain

PacketSwitched

Class

CircuitSwitched

Class

subClassOf

subClassOf

subClassOf

subClassOf

WAN

Class

LAN

Class

PAN

Class

BlueTooth

Class

subClassOf

subClassOf

subClassOf

subClassOf

subClassOf

subClassOf

hasGPRS

ObjectProperty

range

subClassOf

Restriction subClassOf

1

onProperty

maxCardinality

range


Wireless Network Ontology – Services

GSMService

Class

SupplementaryService

Class

TeleService

ClasssubClassOf

subClassOf

CallForwarding

Class

subClassOf

SMS

Class

moSMS

DataTypeProperty

xsd:boolean

range

domain

mtSMS

DataTypeProperty

domain

xsd:boolean

range

Service

ClasssubClassOf

subClassOf

cellBroadcast

DataTypeProperty

domain

xsd:boolean

range

FAX

Class

subClassOf

moFAX

DataTypeProperty

mtFAX

DataTypeProperty

domain domain

xsd:boolean xsd:boolean

range range

...

Class

subClassOf

...

Class

subClassOf


Wireless Network Ontology – QoS ConceptsQoSProperty

Class

LineRate

Class

subClassOf

Delay

Class

subClassOf

Throughput

Class

subClassOf

hasRateValue

ObjectProperty

RTT

ClasssubClassOf

MeanUpTime

Class

subClassOf

ConnSetupDelay

ClasssubClassOf

TimeQoSProperty

Class

subClassOfhasTimeValue

ObjectProperty

domain

RateQoSProperty

Class

subClassOfdomain

ProbQoSProperty

Class

subClassOf

hasProbValue

ObjectProperty

domain

BER

Class

subClassOf

OmissionRate

Class

subClassOf

FrameErrorRate

Class

subClassOf

ConnSetupFailureProb

Class

subClassOf


Related Projects @ TeliaSonera


Related projects @ TeliaSonera

• EU/FP6 projects

– Ambient Networks (IP), Magnet (IP)

– CASCOM (Strep)

• National projects

– CAPNET

– Fuego Core

– Intelligent Web Services


CASCOM – Overview

Context-Aware Business Application Service Co-ordination In

Mobile Computing Environments

• FP6/2 Strep project

– 414 PM/3 years

– 8 partners

• Project goal:

– Develop, implement, validate, and trial of

– Agent-based service coordination infrastructure for

– Innovative semantic Web service discovery, composition, execution

– Across mobile and fixed Peer-To-Peer service networks


CASCOM – Main S&T Innovations

• Generic Service Agent Architecture and Prototype Demonstrator

– CASCOM Service Coordination Means

– Declarative Service Description

– Flexible Service Matching

– Dynamic Service Composition

– Secure Service Execution & Monitoring

– CASCOM Intelligent Service Agents

– Service Agent Platform for Nomadic Computing and Ad-Hoc P2P Communication

– Context-Aware Service Provisioning

– Dynamic Service Agent Coalitions


CASCOM – Use Case Scenario

Ad-Hoc Emergency Medical Care and Ad-Hoc Emergency Medical Care and TransportTransport• Medical information • Patient transport• Insurance coverage


Intelligent Web Services (IWebS)

• Semantic yellow page services

– How the user finds correct service(s)?

– How the service provider advertises the service it provides?

• Dynamic content

• Service composition

• Support for different terminals

– Desktop, mobile, ...

• http://www.cs.helsinki.fi/group/iwebs/


IWebS – Sample Scenario


Summary

• Nomadic environments introduce challenges, such as varying QoS, variations and limitations of the mobile devices, as compared to desktop environments

– Device independence and adaptation are key issues when designing and implementing services for such environments

• Agent architecture with efficient communication

• Ontologies– (Wireless) networks– QoS– Other domains need conceptualization as well

– Services– Users

– Preferences, etc.– Devices


More information

• Heikki Helin and Mikko Laukkanen: Performance Analysis of Software Agent Communication in Slow Wireless Networks. In Proceedings of the 11th International Conference on Computer Communications and Networks (ICCCN'02), October 2002

• Heikki Helin and Mikko Laukkanen: Wireless Network Ontology. In WWRF#9, July 2003

• Heikki Helin: Supporting Nomadic Agent-based Applications in FIPA Agent Architecture. PhD Thesis. University of Helsinki, Finland. February 2003.

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