nrf9160 - can not set PSM

[SilasV]

Hi 

I am working on testing the PSM on my nrf9160 custom board using SLM 

After powering up and setting AT+CFUN=1, when I send the following AT commands:

AT+CPSMS=1,"","","10101010","00100001"
OK
AT+CPSMS?
+CPSMS: 1,,,"10101010","00100001"
OK
AT+CEREG?
+CEREG: 5,5,"590C","03BE4711",7,,,"11100000","11100000"
OK
AT%XMONITOR
%XMONITOR: 5,"Sprint","Sprint","310120","590C",7,25,"03BE4711",108,8665,24,34,"","11100000","11100000","01001001"
OK

It seems the network is not setting the requested PSM timer values - the returned values start with "111" - which means the timer is deactivated. 

Can anyone help me please?

Thanks

[Albrecht Markus Schellenberger]

Hello Silas,

SilasV said:

1. Do I need to use any particular band to be able to use PSM/eDRX feature? or is this available for all the bands? May be I need to switch to that band where PSM is enabled. 

PSM is not depended on any particular band for a certain operator. It only depends on if the operator supports it or if it is part of the agreement between an MVNO (mobile virtual network operator) and the MNO (mobile network operator).

SilasV said:

2. This is more general question: Do all the network providers implement the PSM/eDRX features? This seems to be a very particular requirement for NB-IoT for the battery/power saving.  Why would any network provider not provide this feature? 

Not all network providers support PSM. As I already mentioned, it might not be part of the agreement if it is an MVNO. Some operators do not support it yet and some operators do not want that neither, because they do not want to buffer data from devices not reachable. For some operators, devices have to ask for TAU above a certain limit to be granted PSM (if the device requests a value below the limit, PSM will not be granted). You can check this link which gives you an overview of the Ibasis eSIM national coverage. It provides a list with operators as well and if PSM is supported or not.

Regards,

Markus