[engolling]

Hello Zitoune,
thank you for your feedback. I would like to specify my intention more precise  .

1. My intention with the data logging function was to have the possibility to retrieve some data even if the wireless transmission fails or the RX Unit is out of power for some reason e.g. severe weather condition.
   Even there is no RTC mounted on the module you still can have relative timestamps. So my idea would be to have a logging function on all TX units as a fall back solution if you you want to recover what happened. So the data may not be retransmitted via radio but saved until somebody collects the SD card to check whatever happened to the system. So there should only be the option to save one way to SD, but not a must.
2. My idea for transmission via mobile network would be a far away TX station from that you want to retrieve the data. In my special case I'm thinking of a snow height sensor on a hill for example or maybe you could place a AQM on some relevant but far away point. So the idea would be that normal transmission still runs via 433MHz radio but special TX nodes some kilometers away transmit via mobile network. A possible variant would be a system via web request like wounderground has.
   You could simply use some normal sim cards with unlimited low speed data. In Germany such a plan costs about 3 EUR per month.
   
   Regards,
   engolling