nRF9160 PSM and eDRX Modes

[WesC]

I am using the 9160DK (0.9.0) and testing the PSM and eDRX modes with ncs V1.3.0.  if I program the Asset_tracker without any changes I can connect to the nRFCloud.

from the LTE Link Monitor window i type

AT+CPSMS?

And I get

+CPSMS: 1,,,"00000110","00000010"

                This suggests that I am already in PSM??  The prj.conf has CONFIG_POWER_OPTIMIZATION_ENABLE=n

if I change the prj.conf with CONFIG_POWER_OPTIMIZATION_ENABLE=y and do the same thing i get the same result.

I guess my question is, when using the nRF cloud and LTE link Monitor, how can i tell what mode i am in?

i have used the 

AT+CPSMC?  and AT+CEDRXS?  and get the same answer with and without CONFIG_POWER_OPTIMIZATION_ENABLE = y or n

thanks

[Martin Lesund]

Hi WesC,

The response from AT+CPSMS? is only what the application has requested and not what you have actually been granted from the network.

To get the real value from what you have gotten from the network, you can use AT+CEREG?.

(see Active-Time and Periodic-TAU)

Please see the different options for power optimization in asset_tracker here: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/applications/asset_tracker/README.html#power-optimization

Please make sure you are using a SIM card that gives you access to PSM/eDRX features.
iBasis SIM is limited, depending on where you are located : https://devzone.nordicsemi.com/nordic/cellular-iot-guides/b/hardware-design/posts/ibasis-esim-national-coverage-update

As for now, we do not have support for reading out via AT command if the modem is in PSM mode or not. (it should come in the future)
This best checked via CEREG that you are granted PSM and then through current measurements, you can see when you are in PSM mode or not.

(we have this command, but it only check if the modem is in Connected or in IDLE/PSM mode, so it does not differentiate between RRC IDLE or PSM mode)

BR,
Martin l.