Radio Connection with UE lost before HO required

Radio Connection with UE lost

SgNB initiate this release with UE lost in SgNB release required.
Poor radio condition it should be Handover request but before HO request why this cause sent by SgNB with UE lost?


Is it after call established with SgNB or in addition phase only?

Yes, it is post SgNB addition, but the query is why release with UE lost before HO required?
Or in other way: in what cases SgNB send release required command?

But do you see an A3 event for NR before this?

I faced same it’s due to wrong value of NRARFCN configured At 5G end.

No that’s why I am worried no A3 or A5 configured in RRC reconfiguration message.

Ok, you mean sgnb addition request complete data flow ongoing.
In my case I seen same issue after SgNB addition request message suddenly UE lost happening.

But @Vijay_Chaudhari, if no A3 and A5 configured, this is normal to release the sgNB if end of 5G coverage (Radio connection with UE lost). What else you expect to happen?
Remember that 5G coverage is not the same with 4G coverage.
Different footprint and different PCIs in 4G and 5G.
Specially because in your trace you frequency in sync and out of sync events.
Meaning UE is at the limit of coverage.

5G coverage is poor -113 dBm but before it release with UE lost it should be HO that what i am thinking.

Correct, there are out syn 13 but the query is why HO is not initiated before it release with UE lost.

Do you mean 4G HO?
There is no HO in 5G.
In NSA I mean.
In 5g it works like this: It only releases previous 5G PCI and setup the new PCI.

Handover means SgNB changed with same MeNB.

Based on A3 event.
But for this you should see A3 event which you have not seen in your trace.
So maybe overlapping is poor.

First SgNB to tell for measurement to add object, report config to add object, measurement id to add mod list.

Maybe this could be the reason, thanks @RFSpecialist!. :wink:

Anyway first you should see A3 configured.

Yes, that’s what I am saying, measurement not configured.

Then HO will not iniated.
Blind HO not used in network.
A2 based release can be done if we are using switch.

Maybe are not neighboured in OSS?

Yes, this i will check, thanks.

You can also check if UE sent any measurement reports before loosing
–> if measurement sent but no action taken, network side issue.
–> if no measurements sent then UE side issue that either A2 didn’t trigger (because of RSRP level) and coverage got so poor.