A Framework for Effective Data Transfer

Stijn Bernaer

Patrick De Causmaecker

Joris Maervoet

Greet Vanden Berghe

AMobe - project

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

AMobe

IWT funded project

Stands for ‘Application Development for Mobile Devices’

Executed by the I.T. Department of KaHo Sint-Lieven

°1/9/2002 -- † 31/8/2004

Partners

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Application Development for Mobile Devices

2 coordinators and 2 researchers

“How are mobile devices integrated in applications?” Based on 3 case studies

Development of FrEDT: an (agent) Framework for Effective Data Transfer

FrEDT is a generic agent organisation that manages client-server communication in a wireless environment

Runs on mobile devices with limited capacity

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Agentarchitecture

Programming Platforms

Operating Systems

Agent Platforms

Wirelesstechnology

Platform

sFrEDT

Disciplines

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Wireless communication technology

2.5G: 2G extensions for higher bitrates

Move from phone-oriented to data-oriented networks

Move from circuit-switched to packet-switched data

Average rates - GSM: 9.6 kbps - HSCSD: 28.8 kbps - GPRS: 40 kbps - UMTS: 384 kbps

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Agent architecture

Five trends have dominated computer history:

Ubiquity

Interconnection

Intelligence

Delegation

Human-orientation

How to incorporate these trends in our applications?

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Agent architecture

An agent is a computer system that is able to represent its owner

An agent can find out what it needs to realise its design goals

A multi-agent system consists of communicating agents

Those agents will represent owners with diverse interests and goals. They will have to collaborate, coordinate and negotiate.

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Agent architecture

FIPA (Foundation for Intelligent and Physical Agents) defines standards for heterogeneous and interacting agents and agent-based systems

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Agent architecture

FIPA agents communicate through the use of FIPA ACL (Agent Communication Language) messages

Ontologies decribe the structure and semantics of the message content. A content language provides the message syntax

Interaction protocols define possible sequences of high-level communicative acts (sequence of message types)

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Platforms for mobile devices

Programming Platforms Personal Java

Java 2 Micro Edition (J2ME)

Operating SystemsSymbian OS

Palm OSWindows CE (Pocket PC)

Agent PlatformsAgentLightµFIPA-OS

JADE-LEAPGrasshopper

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Case 1 – Transfer of geographical data

Central geographical database

Mobile employees create Update Reports (UR)

Employees need to transfer these UR’s

Wireless synchronisation process between local and central Update Report DataBase (URDB)

Employees need the most recent Update Reports on regions that will be explored in the near future (pro-active)

Agents regulate the data traffic

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Case 2 – Supporting people with non-congenital brain injuries

People who have problems with coordinating and organising their daily life

Complete database on the supervisor’s computer and a subset of the data on the smartphone/PDA of the patient

Day’s schedule, addresses, instructions, itineraries, shopping lists

Optionally: mobile device for supervisor

Agents act as assistants

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Case 3 – Transfer of medical reports and analyses

Mobile employees visit companies for risk analysis, ergonomic analysis and medical inspection

Employees use a procedure handbook and a program to manage analysis records on their notebook

This book has to be updated regularly and changed records need to be exchanged with a central database

Agents are connection-aware and run in background

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Framework for Effective Data Transfer

Three cases FrEDT Generic agent organisation

Synchronisation mechanism

Wireless client-server environment

Agents negotiate about transactions with different priorities

Goals: to avoid congestion, to find a balance between transaction costs and transaction pending time

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Why agents?

Component-based environment

To assist the end user

Asynchronity = delay independence

Autonomy, continuity

Adaptivity, proactivity

Negotiation

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

FrEDT Ontology

Development of an device context ontology for FrEDT

An example:

Connection AID

Name (STRING)

Bandwidth (INTEGER)

Cost (INTEGER)

UpdateRegistration

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Transactions and decisions

Decisions about transaction planning are taken centrally (no local filtering)

Aware of connection rate and cost. (If necessary, indicated by the user.)

Non-urgent transactions are delayed based on prediction.

Centraltransaction

management

DeviceServer

1: Request

2: Agree

3: Transaction

Centraltransaction

management

DeviceServer

1: Request

2: Agree

3: Transaction

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Negotiation Agent

Represents the device interests

Gathers knowledge about connection speed and costs and passes this information to the Index Agent

Receives application specific transaction requests

Handles further request negotiation with the Synchro Agent

Delegates transactions after agreement (creates temporary Transaction Agents)

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Negotiation Agent

How does the Negotiation Agent gather knowledge about the connection?

Speed: mainly pings (same protocol as transaction) to the Index Agent.

Costs: clustering if possible, else interaction with the user is needed

How often is knowledge about connection updated?

1. When the device logs on

2. After completed transactions

3. Pings at regular times

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Negotiation Agent

Device should know when it is worth to notify the connection change to the central system

Heikki Helin: watermark technique

FrEDT: proportion of current connection to last registered connection

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Database Agent

Transaction Agent

Created by the Negotiation Agent

Is responsible to handle the raw transaction

Lifetime = 1 transaction

Independent on transaction protocol

Separates the framework from the application-specific database

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Index Agent

Holds a central register of logged-on devices and their connections

Devices interact with this agent to keep this register up-to-date

Answers questions concerning this register

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Prediction Agent

Generates predictions on connections and costs

Provides the Synchro Agent with predictions to assist in transaction scheduling

Periodic model (assumes periodic behaviour) with recency effect

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Synchro Agent

Receives transaction requests from interested servers and devices

Schedules transactions - decisions are made based on following indicators:

Application-defined priority (from Negotiation Agent)

Connection rate and costs (from Index Agent) and their predictions (from Prediction Agent) of sender/receiver

Pending time

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Conclusion

FrEDT is suited for effective datatransfer in different situations

FrEDT joins several disciplines: agents, mobile devices and wireless communication technology

Points of attention:

Fault-tolerance and security (provided by the agent platform)

Complex ontological transaction requests

Introduction

Disciplines

Case studies

Motivation

Technicaldetails

Conclusion

KaHo Sint-Lieven – Department of Industrial Engineering – IT Research Group

Demonstration

At the DSP Valley stand …