SDoff: A Software-Defined Offloading Controller for Heterogeneous Networks

The tremendous increase in the mobile data traffic has led the network operators to use offloading solutions in Radio Access Technologies (RATs) such as WiFi or smallcells. However, these solutions are not efficient since none of them controls the offloading from a centralized global network view. Current offloading methods are mostly user-based and they do not completely consider the user satisfaction, and more significantly they do not consider the Quality of Service (QoS) of the whole network system. These aforementioned motivations have led us to design a software based orchestration model for Heterogeneous Networks (HetNets) which is provided by our SDoff framework in a Software-Defined Network (SDN) fashion. This paper presents a novel SDN-based control of smallcell offloading in order to enhance the satisfaction of users and QoS of the overall system by considering a dissatisfaction parameter (psi). The proposed framework analyzes the distance of each user to the all HetNet base stations in the topology by considering different type of users. After that, the offloading decision algorithm resolves which user must be offloaded to which base station by identifying the most dissatisfied user in the topology according to (psi), by evaluating the QoS matrix and user types. Moreover, a new beacon format is proposed in order to maintain a standardized communication between the SDoff plane and virtual representatives (Avatars) of the Data Plane elements. We showed the overall system dissatisfaction difference between SDoff controlled offloading and on-the-spot offloading in the evaluation.