@ scle
Thanks for the information, then the upload link is working fine regarding to the fact that I use LoRaWan encapsulation.
Regarding to the fact that I am sending a wrong character, how should I send it then? As @arjanvanb is showing in his code?
Well I am bot receiving anything at my node, and the worse is that I don't know where it fails, whether my gatewy isn't sending my message or my mote is not receiving it. I am inclined to think that is the gateway the one not forwarding my package to the air...