Many things have been prototyped in terms of communication modes. Just a few examples WSTJ, FT8, PSK31, MSK are all developed by hams for hams.
And there is along and continuing tradition of building your own radio.
Provided you stay within the limits of your license you are welcome to experiment all you like.
Additionally, if you want to exceed the normal limits of your license then you can apply for an experimental license.
Is there also a ban on encryption in the countries where it exists, or is that an FCC-only thing?
I'm interested in this stuff because I just started playing with these: https://cdn.sparkfun.com/assets/a/a/0/b/5/DS_SX1276-7-8-9_W_...
They do spread spectrum on ISM bands with extremely low data rates for insane sensitivity. I want to see what kind of stable distance you can get with lower frequencies and possibly even lower bitrates.
What do you mean? This is running on 433MHz, which is within the 70cm amateur band (420-450mhz)
I haven’t researched the global commonalities, but I’d wager there’s more consistency in HF than the higher frequencies (VHF, UHF).
Interesting, can you provide any more information? How could you do radio that far? Googling shows it is at least 2,092 miles. What kind of radio can go that far?
Also, I'll add a link to http://wsprnet.org/drupal/wsprnet/map . Essentially this shows the transmitter and receiver locations for low power beacons, which might give you a sense of what HF propogation looks like. It will vary according to the time of day and solar conditions.
I want to see it adapted for the lower frequency ISM bands. I just got into ham and SDR this last year and I'm looking forward to making a super long distance super low speed link to my buddies on the other coast as a backup comm channel in case the primaries go down.