Abstract: A basic problem of wireless ad hoc networks is network capacity,which reflects the data throughput of each node with the increasing of network scales. It indicates the scalability of wireless networks. The network capacity of multi channel multi interface hybrid network is constrained by the switch ability of interface among different channels.By constructing the mathematical analysis model, three conditions, interfaccfixed, interfaccconstrained and interface free, their impacts on network capacity were studied, and the upper and lower bounds of network capacity were obtamed. The theoretical analysis results show that the switch ability of interface has great influence on the capacity of hybrid multi-channel networks, and if the interface can freely switch among different channels, there is no capacity loss,which provides the important theoretical reference for network optimization.

Key words: Network capacity, Multi-channel multi-interface, Hybrid, Ad-hoc