关键词: 软件定义无线网络, 惩罚因子, 切换, 接入权值, OpenFlow协议

Abstract: Software-defined Wireless Local Area Network (WLAN) is a trend for managing wireless networks. Aiming at the problems of frequent handover and access failure in AP(Access Point)-intensive environment, an access control method based on global association memory retention of penalty factors was proposed. First, OpenFlow protocol was extended. Second, the extended data messages were used to report network quality, load, throughput, and utilization indicators to the controller through AP. Then, the network index parameters determined by introducing variation coefficient method were used to construct AP access weights. Finally, a global penalty factor was introduced to record frequent back-and-forth handovers in the network, and AP access weights and transmitting powers were modified based on the penalty factor retained by the global memory. Experimental comparison with the strongest signal access method and load balancing access method shows that when the STAtion (STA) moves in a complex network environment, the proposed method can effectively reduce the “ping-pong effect” of the handover, and reduce the number of network handovers and the handover delay, so as to improve the success rate of network handover. Compared with the traditional strongest signal access method, the proposed method has the number of handover requests reduced by 21.7%, which enhances the stability of network access performance.

Key words: Software Defined Wireless Network (SDWN), penalty factor, handover, access weight, OpenFlow protocol