中文摘要：

针对异构网下多终端协同的垂直切换决策问题,提出一种基于模糊逻辑和层次分析法的垂直切换决策算法,它分为2部分：切换时机的判断和虚拟终端的构建.首先采用模糊逻辑判断切换的时机,然后采用层次分析算法与简单加权求和结合的方法选择虚拟终端的最优构成方式.仿真结果表明,算法能够降低切换次数和不必要切换率,并且能够充分体现应用需求和用户偏好.

英文摘要：

In order to solve the problem of vertical handoff decision for cooperation of multi-terminal,a fuzzy logic and AHP （analytic hierarchy process） based vertical handoff decision algorithm was proposed,which included the decision of the moment of triggering handoff and the construction of virtual terminal.Firstly,fuzzy logic was applied to decide the moment of triggering handoff.Secondly,a method combining AHP and SAW （simple additive weight） was used to choose the best composition manner of virtual terminal.Simulation results show that the proposed algorithm reduces the number of handoffs and the ratio of unnecessary handoffs.Additionally,it reflects application requirements and user preferences clearly.