NOTHING. Zero. Nada. Forever and as long as the Mesh devices are operational, you may use the network at will.

The repeaters work with the default settings for Greece: Coding rate: 8 and Spreading factor: 8

Very good question! We wish we knew. This is RF after all! There are 2 repeaters for the moment, one covers all Pothia's basin, and the other the Northern part of the island. The more devices and repeaters are added, the more coverage will expand. In LoRa we trust!

Mesh technology offers 256 bits encryption. That's pretty safe! Plus the fact that any personal channel you create will be encrypted with the unique key of YOUR device, so only the people you want will read your messages and you theirs in that channel.