An Experimental Study of the Impact of Using Multi-Radio in WLAN Mesh Networks

Next-generation wireless mobile communications will be driven by converged networks that integrate disparate technologies and services. Wireless Mesh Networks (WMNs) are expected to be one of the next generation of wireless interconnection technologies, providing flexible high bandwidth wireless backhaul over large geographical areas. While single radio mesh nodes operating on a single channel suffer from capacity constraints, equipping mesh routers with multiple radios using multiple non-overlapping channels can significantly alleviate the capacity problem and increase the aggregate bandwidth available to the network. However, it is well known that multi-radio Mesh platforms face many limitations such as interference, radiation leakage, crosstalk and limited computing resource etc. A misperception among researchers is that the so called "crosstalk" is one of the limiting factors to the performance decrease in multi-radio Mesh networks, but through a series of experiments the results shows otherwise. In this paper, we present a unique experimental approach that utilizes antenna cables, splitters, couplers and attenuators etc. to create a controlled wireless environment, and results indicates, despite negligible effect, crosstalk is not a limiting factor, but rather the finite computing resource constrains the aggregated performance of multi-radio Mesh networks, and several other factors have been investigated as well.