Abstract: In heterogeneous wireless networks, handoff decision schemes need to consider plenty of factors, such as quality of service (QoS) requirements, service costs, user preferences, mobile terminal conditions and access network conditions, and make users and network providers reach win-win situations. This paper characterizes the factors which influence handoff decisions with the knowledge of fuzzy mathematics and microeconomics. On this basis, this paper proposes an always best connected (ABC) supported handoff decision scheme with multi-objective genetic optimization, which improves the decisions quality with the help of elitist selection and individual migration. Based on game analysis, this paper finds an optimal handoff solution of assigning multiple terminals to multiple access networks to make user utilities and network provider utilities achieve or approach Pareto optimum under Nash equilibrium. Simulation results show that this scheme is feasible and effective and has better performance than certain existing schemes.

Key words: heterogeneous wireless networks, handoff decision, quality of service (QoS), multi-objective genetic optimization, always best connected (ABC), game analysis

摘要： 异构无线网络中的切换决策机制，需要综合考虑应用服务质量（quality of service，QoS）需求、服务费用、用户偏好、移动终端状态和接入网络状态等多维因素，进而实现用户和网络提供商的双赢。引入模糊数学和微观经济学知识，对影响切换决策的因素进行了刻画。在此基础上，提出了一种多目标遗传优化总最佳连接（always best connected，ABC）支持型切换决策机制，通过精英选择和个体迁移提高决策质量，基于博弈分析，寻求多终端对多接入网络的最佳切换决策方案，使用户和网络提供商效用达到或接近Nash均衡下的Pareto最优。仿真实验结果表明，该机制是可行和有效的，同现有机制相比具有更好的性能。

关键词: 异构无线网络, 切换决策, 服务质量, 多目标遗传优化, 总最佳连接（ABC）, 博弈分析