Linking handover delay to load balancing in SDN-based heterogeneous networks
A B S T R A C T 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
... te 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. (M. Alotaibi), firstname.lastname@example.org (A. Nayak). reactivity to requests. To tackle this issue, we target the decision before a handover is in effect to make sure that the upcoming/handed-over users will experience a satisfactory level of service and mitigate long delays or breakage. That cannot happen if the new network's controller is over-loaded; therefore, we need to ensure having an efficient load balancing mechanism. The difference in characteristics among heterogeneous wireless technologies imposes the challenge of designing mechanisms to integrate different access technologies, protocols, and service demands [7, 8] . For instance, small cells, such as Wi-Fi hotspots, provide better data rates and cost-effective connections; yet, the security and privacy aspects can be violated. On the contrary, macrocells offered by cellular service providers, ensure higher security and privacy levels, although their services are costly. An interesting discussion was carried on by the authors of  . They addressed the challenges in current heterogeneous networks, as well as SDN promising features to solve some of these issues. The main concept that this paper suggests is "openness" in the wireless world. This concept is currently constrained due to the proprietary and closeness nature of different technology providers. The authors promoted the combined open service irrespective of infrastructure in order to gain access to more wireless capacity. This idea can be beneficial to different applications, specifically, load balancing.