A Performance Study of Mobile Handoff Delay in IEEE 802.11-Based Wireless Mesh Networks

Wireless mesh networks (WMNs) have recently emerged to be a cost-effective solution to support large-scale wireless Internet access. One important component of realizing large-scale WMNs is mobility management. Although mobility management has been extensively studied in cellular and Mobile IP networks, these mobility management schemes can cause significant performance degradation when directly applied to WMNs. In this paper, a performance study of handoffs in IEEE 802.11-based hybrid WMNs is conducted. Since no existing handoff schemes are specifically designed for hybrid WMNs taking into consideration the multihop wireless links in both the wireless mesh backbone and mesh client networks, new handoff schemes for hybrid WMNs are designed. A simulation approach for handoff performance analysis based on OPNET Modeler v12 is adopted and new OPNET models to enable handoff simulations, including both layer-2 and layer-3 handoff models, are developed. A comprehensive study on the handoff performance is investigated and important factors affecting the handoff delay are explained. Performance results demonstrate that the multihop routing protocol plays an important role in the handoff performance.