LTE-NR reselection

Anyone worked on LTE-NR reselection?

That is valid only for 5G SA.
Very few networks in the world have SA.
Basically you have to deal with subpriorities for reselection.

Ok. In LTE-NR reselection, upon RRC release from LTE, UE does registration request towards 5G core with type as ‘mobility registration updating’.

Is my understanding right?

My net is NSA - don’t have reselection.

Ok. I meant LTE -> 5G SA cell reselection.

Have you tried with sib24 configure?

In NSA network don’t have reselection in both paths 4G -> 5G and 5G -> 4G.

Thanks, will try.

Yes… should be that.
I tried with a simulator sometime back.

Yes for SA UE will send registration request follow rrcsetup phase.

Here you can find all details about what UE should do in 5G related to registration:

https://itectec.com/spec/5-5-1-registration-procedure/

In NSA mode NR cell reslection should not be required because when UE is in idle mode it shall be search for LTE master cell.
Reslelction must required in SA mode in area having both LTE and NR coverage.

Yes, correct!
Other point, in NSA there are only RRC_Connected and RRC_Idle modes.
There is no RRC_INACTIVE.

Yes inactive state is defined for SA.

Also there might not be RRC Idle for NSA cell as well, only RRC Connected with ENDC mode and LTE only mode in RRC Idle state.

On very early NW SW release RRC_Inactive wasn’t supported yet (in spite of the fact it’s 3GPP spec’d). I’m not sure whether its a mandatory feature or not.

I seen RRC suspend state as new IE in rel 15 for LTE UE as well in RRC connection release.
Anyone having idea does LTE support RRC inactive state?

INACTIVE State is expected on SA only, if im not mistaken.

I don’t think it’s mandatory as support for it is sent in UE cap.