基于软件定义网络的 WLAN 架构及负载均衡切换

软件定义网络将控制平面与数据转发平面进行分离，并提供开放的编程接口，实现网络的可编程化控制，极大地提高了网络管理的灵活性。在传统无线局域网中，终端通常依据信号强度选择接入点，这一机制往往会造成网络资源利用率低及接入点负载不均衡的问题。提出基于软件定义网络技术的无线局域网架构及一种负载均衡切换策略，利用控制器的全局视角与集中管控能力实现对接入点的实时监测，分析其状态信息并计算权值，由控制器根据负载情况向接入点下发流表，完成对网络的管理。硬件和计算机仿真平台实验表明，与传统的无线局域网架构相比，该方案有效提高了网络的资源利用率，平衡了接入点的负载，降低了数据在终端切换过程中的传输时延，提高了网络的性能。

Wireless LAN and load balance strategy based on software defined network structure

Software-defined network separates control plane and data forwarding plane, providing open programming interfaces, which greatly increases the flexibility of network management. In traditional wireless LAN, terminals usually select the access point based on signal strength, and this mechanism often causes low resource utilization and access point load imbalance. In order to solve these problems, this paper proposes a wireless LAN architecture and a load balance handover strategy based on software defined network. The main idea is to use the SDN controller''s global view of network and the capability of centralized management, monitor and analysis of the status of each access point in the network, compute their weight, and manage them based on load. Hardware and computer simulation platform experimental results show that, compared with traditional wireless LAN, the scheme effectively improves the utilization of network resources, balances the load between access point, reduces the data transmission delay during the terminal handover process and improves the performance of network.