Hello CircuitDojo Community,
I have a basic network registration question: can anyone here provide an AT command or command sequence to query whether the LTE modem is registered with a Mobile Network Operator (MNO)?
For some time I had believed that non-zero responses from issuing AT+CGDCONT? would indicate whether the Sparkfun Thing Plus modem was connected to an MNO who could potentially provide PSM and eDRX mode support. On review of Nordic Semi AT command reference I think I may have misunderstood. My assumption was that a non-zero non-null Access Point Name (APN) was a sure sign my device has connected to / registered with an operator.
Question 2 - is network registration the second of two connection steps in a normal “connect to cell network” process? In other words, must the LTE modem first connect at a radio link level with a tower, and second connect with a carrier or MNO, in some higher level protocol way?
Here I seek to understand whether there is one or multiple levels of network connectivity which I need monitor in firmware, for firmware to know its celular connection status.
Thanks to all who can help on this!