With the development of wireless LAN (WLAN) technology, wireless access points (APs) are deployed increasingly more and the number of mobile terminals is increasing. It is normal for a mobile terminal to hand over its AP. The traditional terminal handover method cannot effectively control the handover delay and balance the network load due to the inherent drawbacks such as closed encapsulation and the lack of centralized control. In this paper, we introduce the innovative network architecture of software-defined networking (SDN), propose a software-defined WLAN architecture, and propose a seamless handover method and a load balancing handover method of the software-defined WLAN. Experimental results show that the proposed handover method effectively reduces the handover delay, balances the network load, and improves the quality of service (QoS) and resource utilization of the network.

随着无线局域网（WLAN）技术的发展，无线接入点（AP）的部署越来越多，移动终端的数量也在增加。移动终端移交其AP是正常的。由于诸如封闭封装和缺乏集中控制的固有缺点，传统的终端切换方法不能有效地控制切换延迟并不能平衡网络负载。本文介绍了软件定义网络（SDN）的创新网络体系结构，提出了软件定义的WLAN体系结构，并提出了软件定义WLAN的无缝切换方法和负载平衡切换方法。实验结果表明，所提出的切换方法有效减少了切换延迟，平衡了网络负载，