Abstract
Software-Defined Networking (SDN) paradigm provides the ability to handle mobility more efficiently due to its programmability and fine granularity. However, in this emerging setting, the handover procedure still suffers delay due to exchanging and processing handover signaling messages. In this paper, we study the relevancy between an SDN controller’s load and handover delay. We show that an over-loading state can prolong handover delay, so as a countermeasure, reaching that state is mitigated by applying a load balancing mechanism. Our primary metric is the controller’s response time, as it directly affects the completion of any mobility-related procedure. We propose a load balancing management framework that deploys two concepts: network heterogeneity and context-aware vertical mobility. Our proposal is composed of three main aspects. First, we identify candidate users based on their context information. Second, we reduce the frequency of load dissemination between multiple controllers, and hence, reducing processing and communication overhead. Third, after the candidate users are determined, we optimize the decision problem on the selection among heterogeneous candidate networks. Through simulation, our framework has shown as much drop as a 28% drop in response time compared to previous proposals.