Estimating NRF9160 TX power consumption based on signal quality

[loumay]

Hi,
Is it possible to estimate the power consumption cost for sending data based on information provided by the modem?

Note from nRF9160 HardwareVerification Guidelines page 9 indicates that power consumption depend on 1) network conditions 2) settings

 > Power consumption is heavily impacted by network conditions, and the settings and may vary significantly.

1) network conditions:

As I understand, the TX power is negotiated by the cell tower and can't be manually influenced.

The modem can provide RSRP, RSRQ and the Signal to noise ratio signal quality. How can we interpret this values to get an hint on the power consumption?

2) settings:

what are the influencing settings here for LTE Cat-M1? PSM, eDRX, ... ?

Thanks,

Louis

[JONATHAN LL]

Hi Luis,

Is it possible to estimate the power consumption cost for sending data based on information provided by the modem?

 There is no support for this at the moment. 

As I understand, the TX power is negotiated by the cell tower and can't be manually influenced.

Correct.

The modem can provide RSRP, RSRQ and the Signal to noise ratio signal quality. How can we interpret this values to get an hint on the power consumption?

I am not aware of any test of this so far.  So i dont have any great suggestions on how to proceed on this for the now.

what are the influencing settings here for LTE Cat-M1? PSM, eDRX, ... ?

 Many things will effect the power consumption and it is very application based. If you are moving or stationary will effect the values, if you try two different places there will be a difference. 

You can test the Online Power profiler for LTE and se how tings change when tweaking the settings, but this will only give you a approximate answer, best way to find out is to measure the power yourself.
Depending on how often and how much data you want to send the answer will be different.   
 

Regards,
Jonathan

[loumay]

Hi Jonathan

Thanks for your reply.

I wasn't aware of the Online power profiler for LTE and it will help.

regards,

Louis

[kratenko]

Hello Jonathan,

as this from a year ago, are there any news on this topic? Are there any plans to support a feature that estimates power consumption? We love the low power consumption of nrf µCs and use them for battery powered products - but right now the modem activity is our biggest unknown in estimating battery life. Everything else can be estimated quite well.

We would love a power consumption estimation feature in the nrf9160 - so any good news for us?

[JONATHAN LL]

Hi,

there is still no feature to estimate power consumption other then the online power profiler. But there is a AT command that can be used, the %CONEVAL command, to see transmit power. 


Regards,
Jonathan

[kratenko]

Thanks for the update. Somehow I actually missed that one so far. Cannot really use it yet, since we mostly have devices on Modem FW-version 1.2.3 - but will keep that in mind for future developments, will come in handy.