When you modulate a carrier signal with high-rate data, the resulting signal spreads out over a large spectral footprint. Higher data rates mean bigger feet. Physics and information theory say so, and they're not negotiating. No matter what you do, though, you're still trying to walk on an attractive but sandy beach instead of powering down that ugly but high-speed asphalt. It's a multi-spectral way of thinking.
Wires are too useful to throw away.
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