the bandwidth isn't the only issue, if you want to be a good radio citizen, you should be limiting you're time on air. in Europe that's between 0.1% and 1% depending on channel used. that reduces the bandwidth by a lot.

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Isn't part of LoRa the ability to have many simultaneuos non-conflicting transmissions because of the chirp modulation and error correction codes? Or is that already taken into account? Regardless, in rural areas this wouldn't be an issue.