Modelling Mobility and Mobile Agents using Nets ... - Semantic Scholar

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The mobility models can be used to introduce mobility to ... (locations) and object net (mobile entity). MOCA'02 .... Some operations of a MULAN MAS developer:.
Modelling Mobility and Mobile Agents using Nets Within Nets Michael K¨ohler and Heiko R¨olke [email protected]

University of Hamburg, Department of Computer Science Vogt-K¨olln-Straße 30, D-22527 Hamburg

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.1/21

Main Topics of the Paper Nets within nets are well suited to express different kinds of mobility. The mobility models can be used to introduce mobility to multi agent systems.

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.2/21

Main Topics of the Paper Nets within nets are well suited to express different kinds of mobility. The mobility models can be used to introduce mobility to multi agent systems. This talk will mainly deal with the second point.

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.2/21

Overview Types of Mobility Multi Agent Nets (Mulan) Example Mobile Agent System

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.3/21

Types of Mobility Mobility is an interplay between system net (locations) and object net (mobile entity).

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.4/21

Types of Mobility Mobility is an interplay between system net (locations) and object net (mobile entity). Differences are introduced by the direction of the synchronisation necessary to perform the migration and its preconditions: No synchronisation: Spontaneous Move

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.4/21

Types of Mobility Mobility is an interplay between system net (locations) and object net (mobile entity). Differences are introduced by the direction of the synchronisation necessary to perform the migration and its preconditions: No synchronisation: Spontaneous Move Object net triggers move: Agent Move

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.4/21

Types of Mobility Mobility is an interplay between system net (locations) and object net (mobile entity). Differences are introduced by the direction of the synchronisation necessary to perform the migration and its preconditions: No synchronisation: Spontaneous Move Object net triggers move: Agent Move System net triggers move: Transportation

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.4/21

Types of Mobility Mobility is an interplay between system net (locations) and object net (mobile entity). Differences are introduced by the direction of the synchronisation necessary to perform the migration and its preconditions: No synchronisation: Spontaneous Move Object net triggers move: Agent Move System net triggers move: Transportation Both nets "agree" upon the movement: Consensual Move

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.4/21

Spontaneous Move

a

on

M

on

models nondeterministic behaviour

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.5/21

Agent Move a on b

:ch() c

on

M on:ch()

free choice of movement: public locations and interconnections

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.6/21

Transportation []

a

P

on

M

on

load balancing, getting rid of agents

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.7/21

Consensual Move movement preconditions a on b

:ch() c

M

on

on:ch() guard (on may move)

(perhaps) the usual case

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.8/21

Overview Types of Movements Multi Agent Nets (Mulan) Example Mobile Agent System

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.9/21

Mobility in Agent Systems (following the FIPA Standardisation proposals) Agents (objects) are embedded in platforms (locations).

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.10/21

Mobility in Agent Systems (following the FIPA Standardisation proposals) Agents (objects) are embedded in platforms (locations). Platforms offer services and control their access.

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.10/21

Mobility in Agent Systems (following the FIPA Standardisation proposals) Agents (objects) are embedded in platforms (locations). Platforms offer services and control their access. Mobility is a special service.

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.10/21

Mobility in Agent Systems (following the FIPA Standardisation proposals) Agents (objects) are embedded in platforms (locations). Platforms offer services and control their access. Mobility is a special service. Platforms differ from services and agents.

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.10/21

Mobility in Agent Systems (following the FIPA Standardisation proposals) Agents (objects) are embedded in platforms (locations). Platforms offer services and control their access. Mobility is a special service. Platforms differ from services and agents. Transparent mobility is an orthogonal concept.

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.10/21

MAS as Nets Within Nets multi agent system p2 platforms

p1

p3 communication structure

p4

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.11/21

MAS as Nets Within Nets O

multi agent system

O

M

agent platform

Z

internal communication

p2 platforms

p1 destroy

new

p3

a agents

communication structure

external communication

p4

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.11/21

MAS as Nets Within Nets O

multi agent system

O

M

agent platform

Z

internal communication

p2 platforms

p1 destroy

new

p3

a agents

communication structure

external communication

agent structure

p4

outgoing

incoming knowledge base kb re

p

pro

protocols

pi

in

MOCA’02 27.08.2002

Mobile Agents

conversations

out

Heiko R¨olke – p.11/21

MAS as Nets Within Nets O

O

M

agent platform

Z

multi agent system

internal communication

p2 platforms

p1 destroy

new

p3

a agents

communication structure

external communication

agent structure

p4

outgoing

incoming knowledge base kb

protocol

re

p

pro

protocols out

in pi

start

subcall

MOCA’02 27.08.2002

process

stop

in

Mobile Agents

conversations

out

Heiko R¨olke – p.11/21

Interplay of Agent and Protocol receive

send knowledge base kb

reactive

p protocols

start

pro-active

in

start in

pi conversations

out

out

stop stop

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.12/21

Overview Types of Mobility Multi Agent Nets (Mulan) Example Mobile Agent System

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.13/21

Some operations of a MULAN MAS developer:

.@

... define protocols define knowledge of the agents define system net (locations and interconnections) ...

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.14/21

View on mobile agent system

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.15/21

View on mobile agent system

(Physical) Location

Network

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.15/21

View on mobile agent system

(Physical) Location

Network

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.15/21

Example Scenario Simple household robot Household containing several rooms Rooms offer services to the robot (kitchen: coffee) Robot has to migrate to accomplish its tasks

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.16/21

Household

frontyard

leave house

enter house

house location

hall hall

move leave hall

enter hall

kitchen living room

enter living room

kitchen

living room

enter kitchen

next room

next room enter next room

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.17/21

Enhanced System View frontyard

fetch mail mailbox

open

leave house

enter house

house

closed location

open door close door

buffer/store state

hall mail read

bureau deposit mail

hall

move service

leave hall

enter hall

extranous action

kitchen enter living room

living room

coffee supply

kitchen fetch coffee

coffee table drunk

living room

serve coffee

fresh coffee

enter kitchen

next room

next room enter next room

new assignment assign new robot

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.18/21

(System Demonstration)

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.19/21

Conclusion Nets within nets are a suitable means to model mobility. Mobility models can easily be integrated to the Mulan MAS. Additional tool support is under development. The aim is AOSE.

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.20/21

Outlook: Tool support

(Physical) Location

Network

MOCA’02 27.08.2002

Mobile Agents

Heiko R¨olke – p.21/21