A drone can operate without requiring a SIM card, carrier contract, or data connection.
The data connection becomes necessary solely for downloading area maps relevant to your flight location. Before reaching the intended flying area, you can download the map using a Wi-Fi connection or at the field using a Hotspot.
When utilizing a Hotspot connection, it is advisable to disable the connection after completing the download to prevent interference, and this should be done before the drone takes off.
To determine when the download of the area map is finished, click on the Map icon within the drone app, and you will be able to view the detailed map.
