1. Communication in Multi-Agent Systems (MAS)
Sohel Merchant
MAPLE Group
CSEE Department
University of Maryland Baltimore County

2. Outline Agent Communication Agent Communication languages
Communication in Herding scenario
Communication Models
Messages
Current and Future work

3. Agent Communication Central to the Agent oriented paradigm
Used to convey across knowledge and information.
Enables
Co-ordination
Co-operation
Negotiation

4. Agent Communication languages
KQML
Independent of transport mechanism, content language and ontology
A KQML message contains a performative / speech act, semantics and an attribute/value pairs
FIPA ACL
Syntax similar to KQML
Messages are communicative actions

5. FIPA ACL Message structure
Performatives
Describes the type of communicative act.
Sender
Receiver
Reply-to
Content
Language

6. FIPA ACL Message structure
Encoding
Ontology
Protocol
Conversation-id
Reply-with
In-reply-to
Reply-by

7. Herding Scenario Basic states
Wander/Search
Align
Herd
Each agent is in one of the above state at any instant of time.
Goal is to herd enemy agent to the home base

8. Communication in Herding Scenario
Why do you need communication ?
Co-ordination
If an agent identifies that evaders are segregated in a particular region then it will send “Help” messages to agents in its communication range
On receiving this message fellow co-operating agents can decide to go to that region and herd enemy agents.

9. Communication Models Distance Obstacles Noise
Probability of messages being received depends upon the distance between agents.
F(x) = 1/x
Where x is the distance
Obstacles
signals can be attenuated due to presence of
obstacles.
Noise
Noise in the environment may garble the messages.

10. Messages
Help
Used to ask for help
Ack
Sent in reply to a message.

11. Dump of Help Message <ACLMessage>
<Domain>Herding</Domain>
<Sender>agentid</Sender>
<Receiver>agentid</ Receiver>
<Content>
<Message-type>Help</ Message type>
<Position>x,y,r,t</Position>
</Content>
</ACLMessage>

12. Current and Future work
Extend the basic herding scenario.
Include a Formation state.
Facilitates herding more than one agent by a group of agents.
Co-operation

13. Current and Future work
4 agents herding one or more agents
Home Base

14. Current and Future work
Dynamic Organization
Emergency Rescue
RoboCup rescue
Extension of RoboCup soccer
Applied to disaster relief
A.R.E.S

15. Thank-you