Software Defined Network (SDN) is more dynamic, manageable, adaptive and programmable network architecture. This architecture separates the control plane from the forwarding plane that enables the network to become directly programmable. The programmable features of SDN technology has dramatically improved network efficiency and simplify the network configuration and resource management. SDN supports Open-Flow technology as forwarding function and centralized control successfully. Wireless environment has recently added to the SDN infrastructure that has rapidly emerged with Open-Flow protocol. To achieve more deterministic network behaviors, QoS provisioning is a necessary consideration. In this paper, the Spanning Tree Protocol (STP) has applied on a SDWN and then analyzed the Quality of Service (QoS) using Mininet-Wifi. STP protocol is used to suppress the occurrence of broadcast streams and observe the performance of the QoS parameters. Various parameters that determine QoS, such as, bandwidth utilization, packet transmission rate, round trip time, maximum obtained throughput, packet loss ratio, delay time is analyzed for different base stations defined in the SDWN architecture.