I'm trying to send SMS via the Telit GE865 modem mounted on the Berlin board.
With an external antenna I have a decent signal as AT+CSQ
reports 17,0 or greater. However I have trouble registering to the network and I'm unable to send SMS.
The SIM card seems to work fine and with a phone placed near the board I can send SMS messages with no problems.
The symptoms are the following:
# Try to register with the default operator
# Tell me the actual operator preference
+COPS: 0,0,"I TIM"
# Looks fine. Are you registered?
+CREG: 0,3 <-- forbidden (?)
# Most of the time I get "forbidden" here.
# If I try hard enough and I'm lucky then one of the following
# attempts succeeds.
# Try a new registration now
# Wait a while and then check
# OK: registered. Try to send a sms.
> Hello World
CMS ERROR: 331 <- no network service.
Sometimes the error message is "Temporary failure" or "Network out of order". I also systematically get "No network service" in response to AT+COPS=? which should scan the operators available in the air.
After each attempt the red led on the berlin board starts blinking fast and a new network registration is required.
Do you have any hint about what I might be missing in order to reliably send a SMS message through the modem?