Quote from: o_e_l_e_o on June 19, 2021, 09:45:19 PM

Quote from: isaac_clarke22 on June 19, 2021, 07:43:11 PM

This topic somehow made me recall of a certain other topics that pertain that if Bitcoin could be sent by SMS.

Entirely possible. Once you have signed a transaction, it can be sent by any medium you like to anybody you like. If you know someone or some service which has an internet connection and would be willing to broadcast it for you, then you can send it to them via SMS and they can broadcast it.

Quote from: tiCeR on June 19, 2021, 09:13:44 PM

I thought I read something about sending Bitcoin without Internet quite a while ago. As far as I know there are ways to broadcast transactions and to receive it as well.

The most developed project is https://txtenna.com/. Basically you buy a small transmitter unit, which connects to other transmitter units in your area to form a local mesh network. When you want to broadcast a transaction, your unit will send it to every other unit in range, each of which will relay it to every other unit within their range, and so on, almost like a mini network of bitcoin nodes. Once it reaches a unit which also has an internet connection, then that unit will broadcast it to the network. You then stay up-to-date with the latest blocks via Blockchain Satellite, again with no internet connection.

You can see the GitHub for this project here: https://github.com/remyers/txtenna-python

This is what I meant, the mesh network. Even the oldest mobile phones are sufficient as far as I know, but you have to have them connected to each other within a certain radius (which is limited by the transmission range). Still I wonder, do you get along with updating and storing the blockchain all the way without Internet? It seems that as you described it.

It would be interesting to have a somewhat practical example or a proven experiment to give the people a glimpse of how this would and could work in case of the absolute worst case no Internet crisis. Like distances of transmitter units, speed, capacity, especially security! Who would run the blockchain in that case, who would do the mining? You can't expect different satellites to be in synch with negligible latency.

A very interesting scenario to think about. Thanks for sharing the info!