摘要： 本文提出了基于SIP的WLAN手机快速漫游切换功能实现的一种方案。在对WLAN切换过程分析的基础上，给出了WLAN快速切换的优化和实现策略，并给出了方案实现的软件框图。

Abstract: The paper introduces a scheme for realization of fast handover in WLAN Handset based on SIP. Firstly, it analyzes procedures involved in WLAN roaming. Then it gives out an optimization and realization mechanism about WLAN fast handover. Finally, the software modules diagram for WLAN handset is provided as well.