[PSM] Why certain T3412 and T3324 request values will get +CEREG notification to return T3412 as 11100000 (disabled)?

[Alan Low]

Hi Nordic team,

One of our customer try to request the (T3324 = 2 secs) and (T3412 = 20 mins) but the +CEREG notification always return 11100000 for T3412 which is disabled.  They checked with their network provider infrastructure team and verified that (T3324 = 2 secs) and (T3412 = 20 mins) are valid values and is allowed by their network.

They also try these values on other modem and is working.

So what could be the reason that cause the network not to except these request values when nRF9160 send them to the network via AT+CPSMS?

[Alan Low]

Hi Håkon,

They are using home registered SIM card. They tried a bigger (T3412=10 hours) and (T3324=1 mins) values and they are able to get an allocated T3412 from network. But the issue now WHY requesting a smaller values like (T3412=20 mins, T3324=2s) will get 11100000 from modem? These small request values are tested on other nbiot modem (eg: ublox) and is working.  

[Håkon Alseth]

Hi,

 

Alan Low said:

These small request values are tested on other nbiot modem (eg: ublox) and is working.  

Is the nRF91 also in NB1 mode?

It is the network that provides values back to the device, from the nRF9160, you can only ask; but the network is the one that ultimately sets the intervals.

 

Do you have a log of the output in at_client when this is tried?

 

Kind regards,

Håkon