User in VoLTE call moving to NSA area

Hi Experts.

If user with VoLTE call move to NSA area and b1 condition meet so will it able to add scg with VoLTE call continue or call will drop here?

If with VoLTE call LTE coverage poor and NR coverage good then can VoLTE call be HO to SA network by IRAT or not?

VoLTE will never drop due to scg addition.
But by parameters you can configure to add SCG or not when VoLTE is ongoing.
Similar when SCG is ongoing it can be released or removed when VoLTE is initiated.

Thanks!
Do you know parameter needed to be enabled in menb or sgnb?
What is recommended value and name of parameter?

In my view reverse movement of voice call from 4G to 5G not possible.
No such feature even after VoLTE call SRVCC to 3G then call not be move to 4G if 3G coverage poor.

Any opinion?

Parameter is in MeNB.
Name will be vendor specific like “endcSupportduringVolte=false” for example.

If VoNR is enabled, then I don’t think any limitation.
But by nature VoLTE/LTE will have better electric field than NR.
Similarly, 2G/3G have better electric field than LTE.

Yes, kind of VoLTE to VoNR handover.
Not sure such feature exist or not.

It should exist.
Such scenarios are quite possible while moving from road to inside mall/cafe where cafe is served by NR cells.

Yes can be proposed in NR new roadmap :grin: but never find such switch at LTE side as of now.
Like we have sib24 and IRAT HO from LTE to NR SA.

VoLTE or VoNR is PSHO and think it exists in v15 even.

Hello VoLTE Experts.

  1. If during ongoing VoLTE call network send RRC connection release what will happen will call drop or bearer reconfigure?

  2. During ongoing VoLTE call, if users move to cell edge then what will happen to VoLTE call if 5G RAT coverage exist there? Will call transfer to 5G or drop?

Call will drop.

If network sends RRC connection release, it should be a drop.

VoLTE to VoNR Handover is possible based on poor coverage.

Normal or abnormal will definitely depend on the cause but in my view it can not result in bearer modification.

Thanks!

For 2 case it’s case of LTE cell down i.e. UE out of service in LTE.

So what will happen here?

Will VoLTE call drop or transfer to 5G cell?

LTE to NR handover is supported so if cell is down HO will not get initiated but if UE leaving LTE coverage and entering NR coverage, then based on measurement results HO can be initiated towards NR.

LTE cell is required to trigger the HO.

Here it’s like sudden lost of LTE cell…

So UE not able to send measurements report.

It’s out of service case.