Contract Net Protocol

Contract Net Protocol

Contract Net Protocol (CNP) is a task-sharing protocol in multi-agent systems, consisting of a collection of nodes or software agents that form the `contract net'. Each node on the network can, at different times or for different tasks, be a manager or a contractor.

When a node gets a `composite task' (or for any reason cannot solve the present task) it breaks the problem down into sub-tasks (if possible) and announces the sub-task to the contract net acting as a manager. Bids are then received from potential contractors and the winning contractor(s) are awarded the job(s).


Task distribution is viewed as a kind of contract negotiation and happens in five stages:

  1. Recognition: An agent recognises it has a problem that it wants help with. The agent has a goal, and either ralises it cannot achieve the goal in isolation (does not have the capability to fulfil the goal), or realises it would prefer not to achieve the goal in isolation (typically because of solution quality, deadline, etc.).
  2. Announcement: The agent with the task sends out an announcement of the task which includes a specification of the task to be achieved. The specification must encode a description of the task itself, any constraints, and meta-task information.
  3. Bidding: Agents that receive the announcement decide themselves whether they should bid for the task. Factors that are taken into consideration are that the agent must decide whether it is capable of the expecting task, and that the agent must determine the quality constraints and the price information (if relevant).
  4. Awarding: Agents that send the task announcement must choose among the received bids and decide who to award the contract to. The result of this process is communicated to agents that submitted a bid.
  5. Expediting: This may involve the generation of further contract nets in the form of sub-contracting to complete the task.

An example is in an electronic marketplace, a system in which buyers specify the goods that they want as well as a maximum price that they are willing to pay. The agent programs then would find other user(s) willing to sell the goods within the desired price range. The user with the lowest price would be selected to fulfill the contract. Other constraints could be applied such as delivery time and the location of the goods.[1]


See also

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Contract Law of Saudi Arabia —    Contract Law of Saudi Arabia Legal System Hanbali School of Sharia Law, Sunni …   Wikipedia

  • contract — Synonyms and related words: OD, abbreviate, abridge, abstract, accept obligation, accord, acquire, affair, affiance, afflict, agree, agree to, agreement, answer for, arrangement, attempt, bag, bang, bar, bargain, bargain for, barricade, batten,… …   Moby Thesaurus

  • Design by contract — (DbC) or Programming by Contract is an approach to designing computer software. It prescribes that software designers should define formal, precise and verifiable interface specifications for software components, which extend the ordinary… …   Wikipedia

  • OSCAR protocol — OSCAR or Open System for CommunicAtion in Realtime is AOL s flagship instant messaging and presence information protocol. Currently, OSCAR is in use for AOL s two main instant messaging systems: ICQ and AIM. Despite its name, the specifications… …   Wikipedia

  • Smart contract — Smart contracts are computer protocols that facilitate, verify, or enforce the negotiation or performance of a contract, or that obviate the need for a contractual clause. Smart contracts usually also have a user interface and often emulate the… …   Wikipedia

  • Network File System (protocol) — Internet protocol suite Application layer BGP DHCP DNS FTP HTTP …   Wikipedia

  • Voice over Internet Protocol — (VoIP, IPAEng|vɔɪp) is a protocol optimized for the transmission of voice through the Internet or other packet switched networks. VoIP is often used abstractly to refer to the actual transmission of voice (rather than the protocol implementing… …   Wikipedia

  • Cubesat Space Protocol — Original author(s) AAUSAT3 Developer(s) GomSpace Initial release 26 April 2010 Stable release 1.0 / October 24, 2011; 0 days ago ( …   Wikipedia

  • Media dispatch protocol — The Media Dispatch Protocol (MDP) is being developed by the Pro MPEG Media Dispatch Group to provide an open standard for secure, automated, and tapeless delivery of audio, video and associated data files. Such files typically range from low… …   Wikipedia

  • CNP — Contract Net Protocol …   Acronyms

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”