PSM behavior when requested during initialization

[DevinCallahan]

I am currently experimenting with moving my request for PSM mode into the "lte_lc_init" routine so that it is configured before the modem is moved to Normal mode.

With this method I am currently seeing this sequence of CEREG status messages:

+CEREG: 2,"9616","05D0FA0F",7
+CEREG: 5,"9616","05D0FA0F",7,,,"00011110","00010011"

That is a message with CEREG status "Searching" and then a message with CEREG status "Attached and PSM Active"

My question then is do I need to account for this message sequence:

+CEREG: 2,"9616","05D0FA0F",7
+CEREG: 5,"9616","05D0FA0F",7,,,"11100000","11100000"
+CEREG: 5,"9616","05D0FA0F",7,,,"00011110","00010011"

That is a message with CEREG status "Searching", then a message with CEREG status "Attached and PSM not active" and finally a message with CEREG status "Attached and PSM Active"

Does the modem include the PSM request with the initial attach request such that I can count on seeing just the 1 CEREG status message indicating "Attached and PSM Active", or is that out of the modem's control?

Thank you!

[Carl Richard]

Hello, Devin!

I must double check with the cellular experts on this, but from what I know the PSM request is included in the initial connection request if configured beforehand. However, I would suggest to always account for PSM not being available, as some networks don't support this.

Best regards,
Carl Richard

[Carl Richard]

Hello again, Devin!

Just got back from the developers that if PSM is configured in offline mode the new parameters are sent to network in next connection request (Attach). In theory it shouldn't be possible to get the set of  indications described by you if network supports PSM.

Best regards,
Carl Richard