In this paper, we propose a novel concept of virtual resource chain for Software Defined Campus WLANs (SD-WLANs). A typical SD-WLAN is composed of three layers, i.e., infrastructure, access control and application layers. Firstly, the network control plane is decoupled from the forwarding plane, and soft-defined access points (SD-APs) merely execute the forwarding rules according to the instructions from access controllers (ACs). Secondly, with a global view of the network, AC could abstract, encapsulate, and virtualize the physical resources (e.g., computing, storage, and radio resources). Finally, by binding all the resources between the infrastructure and access control layers, isolated virtual resource chains are built up and simultaneously mapped to northbound interface (NBI) to accommodate various services at the application layer. Benefiting from the virtual resource chain, a user-oriented load balance scheme is presented in this paper. In SD-WLANs, the load of APs could be balanced according to the user's demands, and our proposed user-oriented load balance scheme could be easily invoked only by coding at the application layer. Experiment results demonstrate that our scheme is able to distribute mobile stations among all the APs and increase the average system throughput, and thus to increase the flexibility and availability of networks.
['Jie Feng', 'Liqiang Zhao', 'Chen Chen', 'Zhiyuan Ren', 'Jianbo Du']
User-Oriented Load Balance in Software-Defined Campus WLANs