NRF9160 Modem Band Scan

[Thomas]

Hi,

Is there any way to tell when the modem has finished doing a band scan? I would like to know so I can swap between CAT-M1 and NB-IoT for globally deployed devices. 

Kind regards,

Thomas

[Thomas]

Hi Hakon,

I am watching it on a power analyser. I can see it attempt scans on an exponential back off schedule dependant on XDATAPRFL. For example in ultra low power mode it attempts a scan, then retries in 20 seconds, 20 seconds, 40 seconds, 40 seconds, 5 minutes then retries every half an hour.

[Hakon]

If you have LTE_LINK_CONTROL=y enabled you can use LTE_NETWORK_USE_FALLBACK=y to change from CAT-M1 to NB-IoT after LTE_NETWORK_TIMEOUT seconds. If you know the time it usually takes to find a network then you can use that as a timeout.

[Thomas]

I am already doing something similar, is there no smarter/power efficient way to do it? Modems we have used in the past automatically switch between the two.

[Hakon]

I don't know, but I doubt it. I will ask R&D and see if they know something about this.

[Hakon]

They confirmed there is no other way than using +CEREG notification.