U.S. Plans to Double Available Wireless Spectrum

Great but doesn't address the issues of density, how many subscribers per switch before degradation of rated signal. Same old song and dance...

Good news for me, I'm in the business of making interference mitigating equipment.

We make digitally tuneable active bandpass filters which amplify only the frequency band you actually use (which is often not the whole channel, and may not be centered exactly on the nominal frequency) and attenuate other frequencies. The user can fine-tune the center of the filter's passband while the equipment is in use to get the best performance.

They are most commonly used in FM radio base stations between the antenna and the receiver, but can be used for other purposes.