nRF9151 - %FEACONF 5 - what does "no cells are available" cover?

[Achim Kraus]

It's now two years ago, and the ticket had a different scope. But one of the answers from Nordic there was:

"This is because the spec mandates that if the device gets rejected by a network with reject cause #12, #13 or #15 (and does not find another network it can attach to), it must stay camped on that cell.

This means that the device will listen for broadcasts from the cell, which will increase the power consumption. The main purpose for this is so that the device can still make emergency calls"

With the new %FAECONF "5 - enables the deactivation of the UICC when the modem detects that it is in an area where no cells are available. The UICC is reactivated when a cell is found." I'm not sure, when that exactly applies.

In the past it seems, that if there is a cell, but the modem is rejected, this is still considered to be the case "cell is found". Could you please clarify, if that applies for "%FAECONF 5"?  

Also not sure, what the scope of deactivation is. As in the old ticket (and the tickets referred there), quite a lot users are very surprised by
unintended power consumption during the inactive periods of the network search configuration. So, is the modem still kept receiving and only the UICC is deactivated? Or is the modem also put into sleep mode when the UICC is deactivated?

[Michal]

Hello,

I will check this internally and get back to you.

Best regards,

Michal

[Achim Kraus]

Thanks!

[Michal]

Just to make sure: you are referring to MFW 2.0.2, right?

[Achim Kraus]

Yes, AFAIK that's the minimum version to support "%FAECONF" with "5".

[Michal]

Thank you. Sorry for the delay, still looking into it.

Hopefully I will have some answers next week.

Best regards,

Michal

[Michal]

I have some clarification on the functionality now:

Maybe this clarifies the terms used. “No cell found” means that no cells were found – neither suitable nor unsuitable. Therefore, the referred “%FEACONF 5” functionality is not related to the earlier discussed functionality where reject cause #12, #13 or #15 was sent by network. This is about deactivating UICC and the earlier discussed functionality was about deactivating the modem. To be noted that “no suitable cell found” often referred means that some cells may have been found, but none of them are suitable for connection (due to radio conditions or SIM subscription).

The referred functionality - enabled by %FEACONF=0,5,1 - will allow deactivation of the UICC when absolutely no cell was found even with a wider scan. The UICC deactivation will be done regardless of the card configuration for the deactivation. This feature is very useful for devices that may be out of coverage for long periods, e.g. tracking a container on a ship, and the SIM card configuration does not allow UICC deactivation. Even if the SIM card allowed the deactivation, some energy would still be saved because with this feature the deactivation is done a bit faster in certain scenarios.

Best regards,

Michal