Comment by bb88

My point is that if you can't do spread spectrum, you've got to think about creative ways to get messages out. Something in the noise floor looks promising even if it's not fast. Further I've seen designs for WSPR that allow the radio to be something like a TTL buffer chip.

If you "announce" yourself you become a target for the signal intelligence folks. Sat phones became a liability in the 2nd gulf war, as they lit up like a beacon saying: "Bomb goes here!".