1 MHz doesn't give a lot of room for frequency hopping and frequency modulation, but that doesn't stop it from being useful for digital transmission. You can st

1 MHz doesn't give a lot of room for frequency hopping and frequency modulation, but that doesn't stop it from being useful for digital transmission. You can still transmit zeroes and ones with amplitude modulation. (The hybrid HD radio tried that, though few Americans bought into that.) The biggest problem with that from micro-usage of the spectrum by personal devices is interference and error correction, but we're doing a veritable ton with Bluetooth today in one of the noisiest and easily interfered with bands in current regulation so there's certainly ideas out there to try. That said, there's also probably nothing wrong with leaving spectrum quiet. We don't need to fill every band possible of the electromagnetic spectrum with digital noise, despite how hungry our devices seem for additional bandwidth.