I'm currently developing an NB-IoT application using Quectel's BC66, however, I'm still trying to decide what operator to use.
After a successful connection, I can use the command AT+CSQ or AT+CESQ to find signal quality.
But all this is assuming I have an operator X SIM card.
After the NPSS/NSSS block up to the PDNConnectionRequest, we have at least 9 transactions between the UE and eNB according to this.
During all these transactions, an operator is still not decided, is it possible to check signal quality at this stage? The alternative would be to have 3 SIM cards and test the connection with each one, one at a time. (We have 3 operators with NB-IoT service available)
I've been searching for this everywhere with no results yet...
After asking Quectel, found out this is not possible. To check signal quality you need a valid connection with the operator.
Either we have a SIM card from each operator and check signal quality using those or we need a SIM card that supports multi-operator (didn't even knew those existed)