Mobility management approaches for SDN-enabled mobile networks

The evolving network technologies aim at meeting the envisioned communication demands of future smart cities and applications. Although software-defined networking (SDN) enables flexible network control, its applicability to mobile networks is still in its infancy. When it comes to introducing the SDN vision to mobile networks, handling of wireless events and mobility management operations stand out as major challenges. In this paper, we study the scalability issues of SDNized wireless networks, specifically those relevant to mobility management. We design and implement different mobility management approaches in SDNized wireless networks and investigate the impact of various system variables on the overall handover delays. We also study the improvements in handover delays: (i) when a proposed proactive mobility management algorithm is implemented; (ii) when the controller delegates partial control of mobility management to the forwarding entities. For the implementation of the proposed approaches on the OpenFlow network, the paper also suggests potential extensions to the OpenFlow protocol. The contributed approaches are validated on a full-scale demonstrator, with results showing that proactive outperforms reactive and that the delegated control approach performs better than proactive for smaller topology sizes. Furthermore, a proposal for LTE X2-specific control delegation is discussed as a use case.