Abstract: Handover latency of heterogeneous wireless networks is an important issue that affects real-time applications in convergence of heterogeneous wireless networks.A new fast vertical handover scheme is proposed to optimize and enhance the existing Fast Vertical Handover Hierarchical Mobile IPv6（FVHMIPv6）.The standardized IEEE 802.21 Media Independent Handover Function（MIHF） is adopted for the proposed FVHMIPv6.The operation procedure for the proposed scheme is described in detail.Finally，the analysis for handover performance is performed，which shows the proposed FVHMIPv6 can optimize and enhance the handover performance of the existing scheme.

Key words: heterogeneous wireless networks, Fast Vertical Handover Hierarchical Mobile IPv6（FVHMIPv6）, Media Independent Handover Function（MIHF）, handover latency

摘要： 异构无线网络间的切换延迟是影响无线网络融合实时应用的重要问题。采用IEEE802.21标准所定义的媒介独立切换功能（MIHF），基于FVHMIPv6提出了一种新的快速垂直切换方案，并详细描述了该方案的执行过程。最后的切换分析表明，结合了MIHF的FVHMIPv6方案可以优化和加强原先FVHMIPv6的性能。

关键词: 异构无线网络, 快速切换层次移动IPv6, 媒介独立切换, 切换延迟