DRX seems not working sometimes

[Tim Chao]

Hi, 

Please see below PPK capture.

I 'm testing with 9160DK, MoSH, LTE-M, and PSM enabled.

There are two "sock send -i  0 -l 500" in the capture, the first one take high power consumption (no DRX waveform).

I did not change and settings between them, and acturally, it happens oftern and randomly.

I wonder it's could be measurement issue? or there are something wrong between modem & carrier?

(modem track attached)

trace-2023-11-08T05-23-33.078Z.bin

[Didrik Rokhaug]

Hi,

cDRX is controlled by the network, so this is probably due to some network (possible mis)configuration.

However, I've asked our modem team to take a look at your trace to see if they find anything interesting.

Best regards,

Didrik

[Tim Chao]

Hi,

Is there any update on the analysis results?

Cause the issue happne on same operator (even on the same cell) and impact on product battery life.
I really want to know if there is anything I can do to optimize it.

Thanks.

Tim Chao

[Didrik Rokhaug]

Hi, and sorry for the late reply.

As the cDRX is controlled by the network, it is a bit difficult to say what happens.

In the log, the network first configures cDRX. However, there is a handover, which clears the cDRX parameters. After the handover, the device does not receive new cDRX parameters from the new cell. The log shows that the signal conditions are quite poor, so it might be that the network tries to configure cDRX, but that the packet is lost.

Regardless of if this is a network issue or a signal condition issue, there isn't really anything that can be done from the device side. However, you can try to test this in better signal conditions, to see if the same happens then.

Best regards,

Didrik

[Tim Chao]

Got it, thanks.

One more question, is there a way to know if cDRX is works or not from system?

For example, if customer complain that the power drains too fast, if I can log something for notice that there may be this issue? Or even, the network does not support cDRX.

Best regards,

Tim

[Didrik Rokhaug]

No, the application doesn't know if it has cDRX or not.