Quote from: roman.z on July 09, 2014, 05:54:53 AM

Good news, every one

I have used today a proper audio cable (instead of a headset) to connect between my PC's audio output and input, so the noise went down dramatically.
This way I was able to achieve 36kbps (after ECC) to successfully transmit 64kB

...

Using 36kpbs MODEM throughput, we can transmit 5MB = 40Mb in ~1111 seconds = 18.5 minutes.

Awesome! Those are very encouraging results. I am busily working on the Armory 0.92 release, but after that I will have some time to see if I can reproduce your results locally. If so, I think you deserve a bounty! I encourage anyone else subscribed to this thread to collaborate with roman.z and see if you can get his solution working and verify that it works. I pay out once I can use the solution to move a 2MB file between two laptops reliably, as long as the performance is somewhat close to what you just described.

Overachiever's goal: can you find the right cables to move data back and forth between a smartphone or tablet? How difficult would it be to demonstrate that you get sufficient performance? I like the idea of taking a tx on your phone to the safe-deposit box, plugging in a 2-way cable between the phone and computer, and letting them do their thing. Or two smartphones -- one online one offline. Granted, android dev is a little out of scope for this bounty, but if we can at least propose a feasible path to getting there and expect that its performance will be acceptable, I think this solution will be 110% complete!