Significantly reducing the number of frequency channels required for wireless mesh networks using beamforming

In a classical multi-radio multi-channel Wireless Mesh Network (WMN) architecture, mesh nodes use omni-directional antennas. Due to the circular radiation pattern of such antennas, when a mesh node communicates with its neighbor on a certain frequency channel, other mesh nodes within its range must remain silent. Directional antennas have been proposed as a way to improve spatial reuse. Since these antennas are non-steerable, they are not suitable for a dynamic WMN. In this paper, we address the problem of co-channel interference in a dynamic WMN environment by using beamforming based on utilizing the multiple omni-directional antennas of a multi-radio mesh node in the form of a linear antenna array. Our novel Linear Array Beamforming-based Channel Assignment method reduces the number of frequency channels required (NCR) for interference-free communication among the mesh nodes. It significantly outperforms the classical omni-directional antenna pattern-based channel assignment approach in terms of NCR for all node-degrees.