What are the possible reasons of "no network service" error with AT+COPS AT command?

IoT Modules
1

What are the possible reasons of “no network service” error with AT+COPS AT command?

2

it might happen because of the multiple plmn entry mapped with the same operator string, it is true in the real world. And modem will choose the first entry directly and apply that plmn for the network attach, straightforward, and error is returned with PLMN not found eventually. However, the desire plmn which the user want to attach is listed on another entry.

3

@akn

It can also be the following.

  • I cannot see any networks.
  • The unit has failed to register to the requested network because the SIM does not have agreements in place to allow it to.

Regards

Matt