nRF9160 RRC Mode Transition

RE: nRF9160 RRC Mode Transition

Hakon — Thu, 16 May 2024 13:55:01 GMT

[quote user="mrks115"]Yes, I know, but there is no way to know which timer is configured, right? Since our device is roaming international obtaining this information from all operators seems impractical.[/quote]

It's not possible to read this from the modem. Perhaps in the future there will be some at cmd for reading this, but not now.

[quote user="mrks115"]Is it specified by the 3GPP?[/quote]

Most probably it's specified there. I can't give you more information because I didn't write this guide.

[quote user="mrks115"]I'm aware that AS-RAI pertains to Rel. 14. While I'm familiar with RAI for NB-IoT in Rel. 13, is there a corresponding feature for LTE-M + Rel. 13?[/quote]

There are two types of RAI:

Control Plane RAI (CP-RAI) - Used for control plane data in NB-IoT.
Access Stratum RAI (AS-RAI) - Used for both control plane and user plane data in LTE-M and NB-IoT.

Is this what you meant?

RE: nRF9160 RRC Mode Transition

mrks115 — Mon, 13 May 2024 07:23:56 GMT

Hi Hakon,

thanks for your reply.

I have one lingering question:

1. What other reasons could prevent the UE from transitioning to RRC idle?
But I guess the application either way has no chance to get notified about ongoing stuff which prevents going to idle.

You need to check what RRC inactivity timer is configured by the network

Yes, I know, but there is no way to know which timer is configured, right? Since our device is roaming international obtaining this information from all operators seems impractical.

RRC timer [...] up to 60 seconds

In the document you referenced, it mentions the above timer. Could you clarify the origin of this 60-second duration? Is it specified by the 3GPP?

I'm aware that AS-RAI pertains to Rel. 14. While I'm familiar with RAI for NB-IoT in Rel. 13, is there a corresponding feature for LTE-M + Rel. 13?

Sorry for all the questions. I think I've got most of the theory down, but I just want to double-check everything to make sure I'm on the right track.

Best regards
Markus

RE: nRF9160 RRC Mode Transition

Hakon — Fri, 10 May 2024 08:21:55 GMT

Hello,

[quote user=""]What other reasons could prevent the UE from transitioning to RRC idle?

Is there any influence we can exert over this process? (besides RAI with NB-IoT)

[/quote]

I am not aware of any other functionalities besides RAI that can reduce the time to go into RRC idle. Have you checked that it's enabled properly and that it's supported by the network?

[quote user=""]Since we have no control over the RRC mode transition, what timeout does Nordic recommend?[/quote]

You need to check what RRC inactivity timer is configured by the network;

"The network dictates the RRC Inactivity Timer period, and the UE cannot negotiate it."

Please refer to this document for more information.

[quote user=""]Have I overlooked anything else?[/quote]

I don't think so.