Disconnects when no bandwidth is being uploaded or downloaded. - Example: Tigo - Tela Honduras
Line of site with the cellular tower is needed if not best.
Modem does not go through concrete walls. --- Solution: Put a SUB cable extension and use clothespins to hang the the USB modem on the curtains. --- Solution: Move you desk in front of window or open the door.
I needed to adjust from Global to CMDA to make it work, I must play with configurations.
It is possible the USB Modem goes into sleep mode.