Service Negotiation Mechanism Of Multi-agent System

Agent technology, especially Multi-Agent technology is playing a more and more important role in distributed computing technology based on network. It can provide not only an effective way to solve distributed application problems but also a conceptual model to study the characteristics of distributed computing system. It is praised as a significant breakthrough in software field.Negotiation is the key technology in Multi-Agent system (MAS). Negotiation is the effective way to compromise some problems in accordance in MAS. In other words, Agents have common desires about cooperation, but there're conflicts in cooperation. Negotiation is the key phase while MAS achieve cooperation, collaboration, conflicts resolving and contradiction handling.Firstly, the author introduces the concepts, technologies of Agent and MAS, and then puts an emphasis on negotiation definition and some key technologies in negotiation. The author introduces the traditional Contract Net Protocol which is used often at present time.Secondly, Based on the analysis of shortcoming and limitation in traditional Contract Net Protocol, the author combines some corresponding research results of our staff room, providing an improved and extended method for traditional Contract Net Protocol.The improving method includes: importing constraints of announcement scope, condition constraints when Agents send out announcements or bids information, sending reject information to un-award agent.Extension method is mainly considering Agents' society attributes in MAS, and also importing society status parameters while negotiation, such as: credit, cooperation frequency and so on. This could strengthen Agents know each other, so Agents' behaviors would accord with human being activities' characteristics and rules; it provides foundation for enhancing negotiation efficiency.Thirdly, at the aspect of designing strategies, we design the call-board as service agency; it can provide communication service for Agents negotiation, so it constraints announcement scope effectively. In the mean time, design acquaintance alliance as unit accepts a task announcement. As the process of task assigning and negotiation is in the internal of an alliance, the announcement scope is definite, so it enhances the efficiency of tasks assigning and negotiation.Finally, the paper introduces an application instance based Zeus—PC Supply Chain System. We apply call-board and alliance mechanism among the system. The manager could control announcement scope and negotiation quality effectively during announcement and bid process, let every PC parts manufacturer achieve their business about PC parts.