Research And Design Of The Wireless Access Network Based On SDN

With the rapid development of the Internet, the number of the Internet users becomes larger and larger. At the same time various Internet applications have been developed. The massive data produced put forward new demands. The tradional network can only work statically. A lot of protocols are deloyed on the network at the same time and the complexity, the low utility and the closed system of the network become increasingly apparent. Under this background, SDN(Soft Defined Network) was proposed. SDN allows the network to be divided into the control plane and the data plane. The control plane is allowed to make decision centrally about where traffic is sent. Moreover, SDN provide open API(Application Programming Interface) for network manager to add or remove application and protocols dynamically.Because of the convenience of wireless devices, users of wireless network take large proportion. This situation becomes a challenge for the wireless access network including how to manage the large number of users, how to improve the utilization of the radio resource and how to deploy new applications. To solve this question, this paper research and design a new system of the wireless access network. Based on SDN structure, this system abstracts the manipulative functions from the data plane, and unifies the functions of managing wireless access and provides open APIs for the managers to handle the wireless access network flexibly.This paper proposes a stategy which apply the idea of the SDN to the wireless access network. According to this stategy, the wireless access network is divided into three levels from the functional architecture. They are application layer, central controller layer, and the infrastructure layer. There is a big difference between this approach and the traditional wireless access network. According to this approach, the applications on the application layer can access the open APIs provided by the central controller layer and control the states of the wireless access facilities timely, which will effect the normal operation of the whole wireless access network. This approach will change the status of the traditional AP even the thin AP architecture which can only work statically. The open APIs provided by the central controller can change regional APs flexibly. But the traditional wireless access network based on the thin AP architecture can not provide the method. Using the open APIs of the central controller can develop various applications and satify the various needs of the wireless access.Compared with thin AP architecture, the managers only work on the application plane and use the uniform open API to manage the regional wireless access network transparently based on the idea of SDN. In this way, managers do not need to configure the APs one by one and it will reduce the workload of the managers greatly. Managers of network do not need to learn the structure of the data plane and the only thing they need to do is to learn the open APIs. The open APIs have changed the static wireless access network. The resources of the wireless access network can be reconstructed by using the open APIs and it will satisfy the various applications of the network. The researchers can develop various applications on the application plane, which provide a convenient and expandable way.