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Can I set a specific RAT as the preferred RAT on a Nordic Semiconductor nRF9160?

Yes. The nRF9160 allows you to select LTE-M, NB-IoT, or both, and define which RAT is preferred using AT commands.

Chandika Ambawatte avatar
Written by Chandika Ambawatte
Updated over 2 weeks ago

Environment

  • Device: Nordic Semiconductor nRF9160

  • Cellular technology: LTE-M, NB-IoT

Question

  • Can I choose which Radio Access Technology (RAT) my nRF9160 should use?

  • How do I force LTE-M or NB-IoT, or set one as preferred on the nRF9160?

Answer

Set the preferred RAT using the AT%XSYSTEMMODE command while the modem is offline.

This is the primary and recommended method on the nRF9160.

Command format

AT%XSYSTEMMODE=<LTE-M>,<NB-IoT>,<GNSS>,<Preference>

The command must be executed when the modem is offline (AT+CFUN=0 or AT+CFUN=4).

LTE-M only

AT+CFUN=0 
AT%XSYSTEMMODE=1,0,0,0 
AT+CFUN=1

NB-IoT only

AT+CFUN=0 
AT%XSYSTEMMODE=0,1,0,0 
AT+CFUN=1

Enable both, prefer LTE-M

AT+CFUN=0 
AT%XSYSTEMMODE=1,1,0,1 
AT+CFUN=1

Enable both, prefer NB-IoT

AT+CFUN=0 
AT%XSYSTEMMODE=1,1,0,2 
AT+CFUN=1

After applying the configuration, the modem will attach according to the enabled RATs and the selected preference.

By default, the nRF9160 supports both LTE-M and NB-IoT. Without explicitly configuring the system mode, the modem may select a RAT based on network availability and internal priority rather than your intended deployment strategy.

For more guidance on this, refer to Nordic's official documentation.

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