A Dual-NIC Mutual Backup Solution of Access Point Handoff in SDN-based Mobile Networks

This With the rapid developing and increasing applications of 5G technologies, a large number of access points (APs) are deployed in public areas to ensure service coverage. When mobile terminals (MTs) are moving, AP handoffs are triggered inevitably. The handoff delay will degrade the quality of communication provided by realtime service applications. As the rise of Software-Defined Networking (SDN) paradigm in recent years, its decoupled mechanism of controlling and forwarding provides a new solution for the AP handoff issue in the mobile networks. In this paper, a solution to AP handoff based on dual network interface controller (NIC) mutual backup (DNMB) is proposed. In the DNMB-based solution, the MT deploys dual-NIC to perform a kind of soft handoff on the link layer, and the SDN controller redirects the traffic to ensure the continuity of the services in the network layer. Furthermore, the most appropriate AP for handoff is selected by an AP selection module applying the technology for order preference by similarity to an ideal solution (TOPSIS). Finally, we simulated and evaluated the proposed handoff process of MTs on an SDN-based mobile network testbed built via NS-3. The experiment results show that the proposed solution can reduce the handoff delay and ensure the quality of communication more effectively compared with the single-NIC solution.