When does the nrf9160 modem decide to perform an LTE network search?

[EDLT]

Hello,

I'd like some clarification on the nrf9160 modem behavior. What is the criteria for the modem to perform a network search?

I've used the default search pattern for ultra-low power profile and subscribe to modem events. When I put the device into a shielded enclosure and it disconnects, I don't see any subsequent search events. However, when I remove the device from the enclosure, I am connected again to the network quickly.

What is the modem doing when it is disconnected? I would expect to get a number of search events within the first few minutes of not being connected. 

Apologies in advance if I'm missing something clearly stated in the 3GPP spec that the describes what is actually going on there.

Thanks!

P.S. Using MF 1.3.1 with NRF Connect 1.9.1

[EDLT]

I've recently noticed that when manually setting the periodic search, the band optimization is ignored. The pattern of light and deep searches does not represent the band optimization value I've chose. Whether the value is 1 or 20, there's no discernible difference in behavior. See attached picture. Here I've set the search pattern band optimization to 5, so I expect every 5th search to be all the bands I've locked in (2,4,5,12).

Is this the correct behavior? Have I missed something?

I do have the data profile set to ultra low power...this value also seem inconsequential.

[Michal]

Hello,

I have some insight from our experts.

<band_optimization> parameter in the %PERIODICSEARCHCONF configuration refers to “all band search” in the AT command document. It is not possible to affect on whether modem does light search or full search. The “all band search” means that every supported band will be fully searched. The other searches in between these “all band searches” are something less, i.e. it does not specifically mean the light search. If there were more bands locked or no band lock at all, the difference could be seen.

Best regards,

Michal

[Achim Kraus]

In the case of 1 => "depending on %XDATAPRFL", is there any documentation, what the values 0-4 there means? Except, that the power consumption is considered to be higher and lower?

[Michal]

According to the note on the infocenter, this command is for future releases and has a limited impact currently:

Note: This command is for future releases and will be extended with new parameters later. In the current software release, the use of this command has limited impact on power consumption.

I assume that the documentation on that will be extended in the future as well.

Best regards,

Michal