SWAN: An SDN based campus WLAN framework In order to provide quality of service (QoS) guarantees to the campus WLAN users, typical campus WLAN systems need to provide a variety of services in a scalable manager. However, the existing campus WLAN solutions are proprietary, closed-source and expensive, which limits the network’s flexibility and expansibility. In this paper, a Software Defined Networking (SDN) based campus WLAN framework SWAN is proposed. The key conceptual contribution of SWAN is a principled refactoring of campus WLAN into control and data planes. The control plane has a centralized global view of the network and bundle operations into Application Programming Interface (API) for upper applications. Besides, we construct software access point (SAP) to abstract the connection between the user equipment (HE) and access point (AP). Network operators can utilize these APIs and the SAP abstraction to design programs to manage and configure the network. Hence, SWAN makes campus WLAN more flexible and expansible.