The Contract-Net with Confirmation Protokoll: An Improved Mechanism for Task AssignmentMichael Schillo; Klaus Fischer; Tore Knabe
DFKI, DFKI Technical Memos (TM), Vol. 01-01, 2001.
The Contract Net Protocol was designed for distributing one task among a number of agents. However, up to now it remains an unanswered question which policy the agent should use for resource allocation, i.e. in what manner it should reserve resources for tasks it made a bid for. If the agent allocates too many resources too early, it may not get its bid accepted and therefore resources will not be available for other tasks. If it allocates too late, it may have committed to more tasks than it has resources. The major inefficiency in the CNP is that in every execution of the protocol all participating agents need to commit themselves to do the job, although only one of them will actually get the award. In this document we present the contract net with confirmation protocol (CNCP), which precisely addresses this issue and improves the CNP procedure by drastically reducing the number of commitments made. We also present an extension of this protocol for the cascaded application of the protocol, i.e. the case where bidders in the protocol can again start an instance of the protocol to subcontract the whole or parts of the task.