Design and Implementation of a Hybrid Channel-Assignment Protocol for a Multi-Interface Wireless Mesh Network

Both multi-interface and dynamic channel adjustment are prevailingly used to improve the capacity and the flexibility of wireless mesh networks (WMNs). However, overheads that are generated by uncontrolled interface switching adversely decrease the performance of WMNs. To find a reasonable tradeoff between flexibility and switching overheads, we propose a hybrid channel-assignment protocol (HCAP) for multi-interface WMNs. The HCAP adopts a static interface-assignment strategy for nodes that have the heaviest loads to avoid frequent interface switching, whereas it adopts a hybrid interface-assignment strategy for other nodes to improve the ability of adapting to flow change. In our implementation, we present a slot-based coordination policy. Extensive NS2 simulations demonstrate that the HCAP improves network capacity, enhances flexibility, and guarantees interflow fairness.