Send Data through LoraWan Network


I am developping apps on FX30S modem from Sierra Wireless. I would like to send data through the LoraWan IOT network then I add a mangoh ACW IOT card. I found that there is 2 way to do that :
1- Use the ARMAPI developped by ATIM for use easily the IOT card ( But it seems like this library use some functions who are not running on legato (like usleep()).
There is a way to use this API for my application?

2- Use directly ARM_N8_LW AT command on my app. I already tried but without success. Maybe someone who has already done this can share his configuration and his protocole?

Best Regards