ncs v3.0.0 nRF9160 SMS PSM eDRX

[peter.min]

Hi,

1.As shown in the following PSM eDRX figure, during the red period, how will the text messages sent to nRF9160 be processed? Will the nRF9160 module receive them in the next green period?
2. Why can't customers receive SMS messages during the red period but not during the green period when they are tested with China Mobile's CMNBIOT?

Kind regards,
Peter.Min

[Susheel Nuguru]

Hi Luke, 

This seems some issue that needs internal investigation. I have reached to the R&D team by creating an internal investigation tracking thread. For your reference, the internal tracking number is NRF91-2505. I will come back to you when I have more info on this.

[Luke Long]

Hi Susheel Nuguru,

Many thanks. We are also trying to see if we can capture modem trace for your reference. Will update soon.

[Luke Long]

Hi Susheel Nuguru,

Here attached the modem trace, hopefully it's helpfu. 

trace-2025-06-13T12-52-52.247Z for SMS NG3.mtrace

[Susheel Nuguru]

Luke,

I think SMS queued during PSM and sending when the device is active needs to be supported by the network, else the SMS can be lost (it seems) Or maybe the message gets expired on the network which is different for different networks.

I would ask China Mobile NB-IoT technical guys to see if SMS queue in PSM is supported and find out what their SMS expiry timeouts are in their network. I would also 

You need to read the PSM/SMS status dynamically in the code to get more details on network supported timeouts and feature support.