nRF9160 confirming support of both NB-IoT and LTE-M in same firmwares without reflashing

[aetheriumjim]

Our application requires switching between NB-IoT and LTE-M without flashing firmware of any part, including modem.  We were recommended the nRF9160/nRF52840 due to this capability.  I noticed in the modem firmware release notes (1.3.1 at time of writing) that this feature was introduced in version 1.3.0 so should be workable with our dev kit.  From the release notes, new functionality of 1.3.0:

- Feature for application to enable both LTE-M and NB-IoT system modes. In this mode modem automatically uses both systems while searching for suitable cell. Application can configure which one of the system modes is preferred system and whether system shall be preferred over network, or the opposite. Feature can be utilized by using existing AT command AT%XSYSTEMMODE.

However while evaluating the board for the first time, I've been following the latest Getting started with nRF9160 DK guide which (in multiple places) it mentions the need to select either an LTE-M hex file or an NB-IoT hex file for the application firmware.

Can anyone please confirm that the nRF9160 really can switch between NB-IoT and LTE-M without requiring any flashing at all - with identical 'modem' and 'application' firmwares (selecting whichever is available)?

I'm surprised there is no sample application firmware to demonstrate this essential feature.  For us, this feature is a deal-breaker.

Other askers have asked similarly but I believe with the new firmware in light and lack of demonstration or mention in the documentation begs to reframe the question.

[Albrecht Markus Schellenberger]

Hello, 

Can anyone please confirm that the nRF9160 really can switch between NB-IoT and LTE-M without requiring any flashing at all - with identical 'modem' and 'application' firmwares (selecting whichever is available)?

I'm surprised there is no sample application firmware to demonstrate this essential feature.  For us, this feature is a deal-breaker.

Other askers have asked similarly but I believe with the new firmware in light and lack of demonstration or mention in the documentation begs to reframe the question.

The application firmware images are intended to be a starting point for evaluation of our development kits. For everything else beyond this scope, customisation is necessary. 

However while evaluating the board for the first time, I've been following the latest Getting started with nRF9160 DK guide which (in multiple places) it mentions the need to select either an LTE-M hex file or an NB-IoT hex file for the application firmware.

You have two alternatives: 

1. Re-configure the desired application to support both LTE-M and NB-IoT using CONFIG_LTE_NETWORK_MODE_LTE_M_NBIOT or CONFIG_LTE_NETWORK_MODE_LTE_M_NBIOT_GPS, followed by a rebuild.  
2. Flash the AT Client or Serial LTE modem application firmware image and use %XSTEMMODE to re-configure modem system settings. 

Regards,

Markus

[Albrecht Markus Schellenberger]

I'm surprised there is no sample application firmware to demonstrate this essential feature.  For us, this feature is a deal-breaker.

By the way: You have a really good point here. I have forwarded your feedback internally :-) 

Regards,

Markus

[aetheriumjim]

Thanks for the reply and the recommendations.  As I understand it now, it really is possible to work both NB-IoT and LTE-M at the same time (since 1.3.0) without requiring any firmware change to modem or application firmwares — it's just that there's no precompiled demo hex file in the getting started guide yet — but it is possible with a user program.

I'll follow your pointers and look into the recommended alternatives.