NB-IoT RRC Connection Re-establishment on nRF9161

RE: NB-IoT RRC Connection Re-establishment on nRF9161

Øyvind — Mon, 04 May 2026 11:49:36 GMT

Hello,

[quote user="fdup78"]One final query: is RRC Connection Re-Estab also supported on nrF9160 ? If that's the case, any specific AT command needed, and with which minimal FW version?[/quote]

Our team responds with the following answer:
RRC Connection Re-establishment for NB-IOT is supported from MFW-2.0.0 onwards - no specific AT-command needed. For HW-wise, MFW-2.0.0 is supported only in nrf91x1 hardware → So, not supported in nrf9160 at all.

Kind regards,
Øyvind

RE: NB-IoT RRC Connection Re-establishment on nRF9161

fdup78 — Thu, 30 Apr 2026 08:57:13 GMT

Hello Øyvind,

No worries, thanks for the detailed answer and the recap !

One final query: is RRC Connection Re-Estab also supported on nrF9160 ? If that's the case, any specific AT command needed, and with which minimal FW version?

Best regards,

François

RE: NB-IoT RRC Connection Re-establishment on nRF9161

Øyvind — Thu, 30 Apr 2026 07:02:45 GMT

Hello François,

My sincerest apologies, this question did get an answer but fell of the radar with the other tickets/questions. Here is the answer I got back in June 2024

RRC connection re-establishment is supported in nRF9161/51 in NB-IoT mode. There is no AT-command to enable/disable it.

Reduced Mobility feature (3GPP Relaxed Monitoring TS36.304 and Nordic-proprietary feature) based on %REDMOB command

In nRF9161/51 %REDMOB command parameters are these:

0 - enable 3GPP Rel14 Relaxed Monitoring feature

1 - enable Nordic proprietary Relaxed Monitoring feature

2 - disable 3GPP Rel14 and Nordic proprietary Relaxed Monitoring features and enable full measurements to achieve best possible mobility.

Relaxed Monitoring feature applies to both NB-IoT and LTE-M systems.

LTE-M Data Inactivity Timer

In nRF9161/51 Data Inactivity Timer is supported by default. There is no AT-command to enable/disable it.

NB-IoT Dual HARQ and Max TBS size enhancement

In nRF9161/51 NB-IoT Dual HARQ and Max TBS size enhancement are supported by default. There are no AT-commands to enable/disable those.

Let me know if you need more information on this topic.

Kind regards,
Øyvind

RE: NB-IoT RRC Connection Re-establishment on nRF9161

fdup78 — Wed, 29 Apr 2026 14:14:00 GMT

Greetings,

Would it be possible to get an update on the level of support of this feature on nRF91x1 modules ? Any specific minimum firmware required? Any AT-command to enable/disable?

Is it by chance now also supported on nRF9160 ?

3GPP Rel-14 introduced NB-IoT RRC connection re-establishment in Control Plane CIoT EPS optimization mode. It is a Connected Mode Mobility (CMM) enhancement : in case of radio link failure, it allows UE to move from one cell to another without having to renegociate a new connection, for improved service continuity. It works as follows : if a source eNodeB fails to send downlink NAS data to a UE, it returns the data to the MME. The MME then instructs a target eNodeB to send the data to the UE.

The eNB indicates to the UE that RRC connection Re-establishment is supported via the SIB2-NB channel.

Best regards,

François.

RE: NB-IoT RRC Connection Re-establishment on nRF9161

Øyvind — Wed, 26 Jun 2024 07:05:42 GMT

Hello François.

I'm not able to find any information on this in the current nRF91x1 Cellular AT Commands document. I will need to ask internally. I hope to have an answer by end of tomorrow.

Kind regards,
Øyvind