cDRX- High current consumption

[nickagianFT]

Hi,

I've been trying to verify how much charge is needed to operate the nRF9160, so I did some measurements using the nRF9160-DK and the Power Profiler Kit II. I started with the recommended udp sample code (SDK version is 2.2.0). I could see that during the PSM mode, the consumption was as low as expected, but I found some inconsistencies regarding the eDRX phase, where the current profile looks different from what I've seen in other waveforms and tutorials (for example here https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/app_dev/optimizing/power.html) and consequently the average current draw is also higher. In the beginning, I had the iBASIS sim card and later changed to a local operator here in Denmark, in case the roaming mode was important, but I didn't see any changes in the power profile.

Have a look at this capture, which shows the whole transaction:

and then also a zoom-in to the eDRX phase:

I also have a modem trace file, if it helps: 1122.trace-2023-04-14T08-36-53.639Z.bin

My basic question is whether this behavior is just what the specific network here in Denmark does, therefore I can't do anything to improve it, or whether this is somehow hardware/software related and I can do something to bring the consumption down.

[Håkon Alseth]

Hi,

 

nickagianFT said:

Is this 9 seconds initial phase to connect to the network that you mention starting right after boot or a bit later, after the first short interval where the consumption drops really low?

Based on your original image, the window size is 10 seconds, and the total boot + enter PSM fits in between the window.

nickagianFT said:

Does that mean that all this long period in-between the long spikes the nRF91 is still trying to connect? I'm then a bit confused about how to identify the phases shown in the OPP.

That is your cDRX period, mixed in with the actual network traffic of the "udp" sample. The sample will do a DNS lookup and fetch NTP network time.

If you check out our power calculator:

 Online Power Profiler for LTE 

This has a preset for Telenor (Norway), which should be similar (but not exact) to how it behaves in your region.

 

Kind regards,

Håkon