GSM network problem

Not if you are correct that AT+CREG? returns “1” for “stat” - ie, the unit is registered on its Home network.

Can you speak to technical staff at the network operator about this?

Or your Distributor or FAE - it might be a known “feature” of your local network(s)…

As noted in the link I gave, it does seem that AT+COPS=0 does more than is documented, and does allow an escape from some “anomolous” registration conditions.

I haven’t seen the condition you describe, so I don’t know whether AT+COPS=0 will help in your particular case or not - you will have to try it yourself to see what happens!

Great - please post the results!

Again, this behaviour of AT+COPS=0 is undocumented - so who knows whether there might be any problems in doing this…?

If AT+CREG? is, effectively, lying to you, then I don’t think that there’s a lot you can do!

Unless there is some other feature of your application that you can use; eg, * is GPRS affected?

  • Do AT+CSQ or AT+CCED or any others give any useful hints?
  • Can the unit send and/or receive SMS in this state?
  • Does your application expect some regular incoming contact, and can it use that as the basis for a timeout to deduce that it has lost comms…?