Hello CircuitDojo Community,
I am a good ways into development of an nRF9160 based project’s firmware, which I developed some ways on a Sparkfun Thing Plus nRF9160 and later on a somewhat similar custom hardware. I am yet using both boards for firmware development. I am also at a blocking point as I exercise and test various LTE modem settings, via an AT command API provided by Nordic Semi.
Specifically, with firmware running and compiled with Nordic’s at_cmd_handler API, I’m issuing AT+CPSMS=“…”. I’m confident my command syntax is correct. I am consistently able to read back the Power Savings Mode values I am requesting, by issuing AT+CPSMS?. Most of the time the LTE modem on hand is granted a non-zero PSM or periodic-TAU value, but this value invariably is granted as 54 minutes, “01001001”.
Is it normal for a Mobile Network Operator (MNO) to grant only one, fixed periodic-TAU PSM value to user equipment?
By the way I issue AT%XMONITOR to review which PSM values are granted.
So far given my limited AT command experience, I have only been checking that our LTE modem is in its powered mode, that is AT+CFUN? returns a powered status of 1, rather than 0 or 4 or something else. I have also been checking that the board I’m testing, with SIM of course, is connected to an MNO. The AT command
AT_CGDCONT? returns a reliably longer string when the LTE modem has an established connection with a cell tower.
Question 2 - in order to be granted more than one fixed periodic Tracking Area Update value, is there some further before or after AT command sequence I need, around my issuance of