A Mediator-Based Agent Negotiation Protocol for Utilities That Change with Time

Multiple-issue negotiation has been studied extensively because most real-world negotiations involve multiple issues that are interdependent. Our work focuses on negotiations with multiple interdependent issues in which agent utility functions are complex and nonlinear. Issues being interdependent means that it is not appropriate to negotiate over issues one-by-one. The decision on one issue is dependent on decisions about previous and subsequent issues. In the literature, several negotiation protocols are proposed: bidding-based protocol, constraints-based protocol, secure SA-based protocol, etc. However, all have assumed that utility does not change with time, whereas in reality, this may not be the case. In this paper, we focus on finding and following the ”Pareto front” of the changing utility space over time. To find and follow the Pareto front effectively, we employ an evolutionary negotiation mechanism, in which a mediator takes the lead in negotiation based on GA. The experimental results show that our approach is suitable for the case where utility is dynamically changing over time.