Directional antennas and radio networks

Spectrum management (SM) is a well known important issue [1]. Demand for RF spectrum already exceeds supply [2]. The advent of cognitive radio functionality and other SM advances, while important, have actually been constrained by an almost exclusive focus on omni-directional antennas, with scant attention paid to the spectrum deconfliction benefits accrued from advanced aperture technologies. Advanced apertures with directional beam steering capabilities can reduce a network's electromagnetic “footprint”, and consequently its vulnerability to unintentional interference, while maintaining connectivity. These devices will have a profound impact on SM and software-defined radio (SDR) technologies.