Competitive Contract Net Protocol

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• Competitive Contract Net Protocol
• http//agents.felk.cvut.cz/c-cnp
• Jirí Vokrínek, Jirí Bíba, Jirí Hodík, Jaromír
  Vybíhal, Michal Pechoucek
• vokrinek,biba,hodik,vybihj1,pechouc_at_labe.felk.cv
  ut.cz
• Gerstner Laboratory, Department of Cybernetics
• Faculty of Electrical Engineering
• Czech Technical University in Prague
• Czech Republic
• 24th January 2007
• Jirí Bíba
• SOFSEM 2007
• Harrachov, CR

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Outline...

• Motto By concluding commitments the game does
  not end, but rather starts!
• Negotiation protocols for real-world competitive
  domains should allow for the natural behaviour of
  the involved parties, enable flexibility of
  cooperation, and take into account whole
  life-cycle of negotiated commitments with respect
  to their duration, eventual evolution and
  termination.
• Agent Environments (cooperation, commitments,
  flexibility)
• Interaction Protocols (limitations)
• Competitive Contract Net Protocol (C-CNP)
• Performatives in C-CNP (semantics)
• Conclusion
• Discussion

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Agent Environments

• Collaborative Multi-Agent Environments
  (Intra-Enterprise Level)
• definition agents primary motivation is
  maximization of their common social welfare
• cooperative problem solving based on social
  commitments (W.J.)
• a-prior willingness to cooperation, common
  rationality joint intentions (commitments kept,
  reconfigured or commonly dropped)
• Competitive Multi-Agent Environments
  (Extra-Enterprise Level)
• definition agents primary motivation is
  maximization of their individual utilities
  (self-interested agents)
• agents are willing to take on obligations only if
  rewarded, individual rationality intentions may
  result in dropping the commitments
• full commitments vs. levelled commitments
  (decommitments) (S.L.)
• explicit metrics of utility desirable motivates
  agents to
• (i) enter commitments (rewards)
• (ii) comply with commitments (penalties)

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Interaction Protocols

• One-to-one/One-to-many/Many-to-many
• Monotonic Concession Protocol
• n-agent extension of Monotonic Concession
  Protocol
• Extended CNP and derived protocols
• FIPA Query/Request Interaction Protocol
• FIPA Dutch/English Auction Interaction Protocol
• FIPA Contract Net/Iterated Contract Net
  Interaction Protocol
• Limitations of commonly used protocols
• usually designed for collaborative environments
  (although sometimes used inappropriately in
  competitive environments)
• usually do not cover all the contract/commitment
  life-cycle (conclusion, eventual evolution,
  termination)
• lack of (standardized) interaction protocols for
  deployment in real-world competitive environments

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Competitive Contract Net Protocol

• FIPA-like, multi-phase, multi-round interaction
  protocol hybrid state/sequence diagram of C-CNP

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Competitive Contract Net Protocol

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Competitive Contract Net Protocol

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Competitive Contract Net Protocol

Contract Conclusion Phase
Contract Termination Phase
Optional Decommitment Phase
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Competitive Contract Net Protocol

Contract Conclusion Phase
Contract Termination Phase
Optional Decommitment Phase
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Competitive Contract Net Protocol

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Competitive Contract Net Protocol

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Performatives in C-CNP

• Re-defined FIPA Performatives
• less significant re-definition (almost FIPA
  compliant)
• CFP, PROPOSE, ACCEPT_PROPOSAL, REJECT_PROPOSAL
• more significant re-definition
• AGREE generalized
• REFUSE generalized
• CONFIRM generalized
• INFORM (FAILURE) generalized (specialized)
• New Performatives
• IMPOSE_PROPOSAL 3rd-party-info-based contract
  proposal
• COUNTER_PROPOSE modified proposal by negotiation
  initiator
• DECOMMIT start of an optional decommitment
  negotiation
• TAKE_BACK backing off from decommitment
  negotiation by payer
• PROPOSE_PENALTY penalty proposal by the receiver
  (victim)
• COUNTER_PROPOSE_PENALTY penalty proposal by the
  payer

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Conclusion

• Results
• interaction protocol C-CNP for flexible
  cooperation in competitive environments allowing
  for commitments evolution and contract-conditions-
  compliance assessment with emphasis on deployment
  in e-commerce contracting (i.e. complete
  contract specification expected to be the subject
  of a multi-attribute negotiation)
• implementation of C-CNP in JADE agent platform
  v3.3, supporting parallel run of multiple C-CNP
  in one time, multilevel execution and alternative
  protocol timing mechanism (machine time or
  externally triggered timer) http//agents.felk.cv
  ut.cz/c-cnp
• Future work
• extension of the C-CNP protocol for contract
  re-negotiation (reconfiguration/outsourcing
  support)
• algorithms and iterative approximate acquaintance
  models for (reconfigurable) contracting allowing
  for information inaccessibility, limited
  resources and reputation issues

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Discussion

• Thank you for your attention!
• Acknowledgements
• This research work is part-funded by the
  European Commissions FP6 programme within the
  projects European Collaborative Networked
  Organizations Leadership - ECOLEAD (contract NO.
  506958) and Collaborative Process Automation
  Support Intelligent dynamic Agents in SME
  clusters - PANDA (contract NO. 027169). The
  research is also part-funded by the Ministry of
  Education, Youth and Sports of the Czech Republic
  grant No. MSM 6840770013.
• Any opinions expressed in this presentation are
  those of the author(s)/organisation and do not
  necessarily reflect the views of the European
  Community. The Community is not liable for any
  use that may be made of the information contained
  herein.