I. Introduction
With the rapid development of high-data-rate multimedia services, the wireless data traffic is explosively growing worldwide, which leads to high burden on the current communication networks [1]. To satisfy the increasing demand and relieve the network pressure, the technique of centralized processing is considered as one possible solution in the coming 5G communication networks for more efficient resource utilization [2]. Recently, cloud-based software-defined wireless network (SDWN), which combines the SDWN multi-layer framework with cloud computing, is drawing much more attentions as a promising architecture [3]. In cloud-based SDWN, with a centralized controller in the cloud, the control plane is separated from the data plane, and higher efficiency can then be achieved for resource allocation and better system performance [4].