I'm very interested in the ability of Android phones to send a text message from one phone to another without using a cell tower (peer to peer). I haven't yet found something online that discusses the particular physical channel used for this purpose - I hope it isn't limited to something like bluetooth. What is the maximum conceivable range given US FCC laws of the peer to peer message? Could it be longer in other countries? In this group, I searched for the word peer and I looked over the API top-level documentation. Is anything known yet?

In particular, I've always wanted an alternative to shouting climbing commands to my partner and FRS radios have always seemed unappealing, big, heavy, and noisy. I'd much rather text message ability and heck, I'd have my phone with me anyway which may have coverage on parts of the climb. This is a 60 m range problem and sometimes around the corner of a rock rib (which could require some significant Eb/No at the output device, but then that is one of the points of messaging, keep the #of bits low and low power can still work great).