What happen if with ongoing NSA call suddenly user dial VoLTE call?

5G NR
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1

Hi NR Experts.

Need to discuss below 2 scenario:

  1. What happen if with ongoing NSA call suddenly user dial VoLTE call?
    Will scg leg be released or call not allowed?

  2. With ongoing VoLTE call in LTE is it possible to add scg cell or not?

2

Both the points depend upon eNB configuration.
Some vendor allow to set parameter by which once VoLTE call us attemted SCG is released.
It is added again once call is finished.
VoLTE bearer is always created as MN terminated MCG bearer.

3

Ok thanks.
So crux is that endc can’t work with VoLTE call means scg to be released in any condition.

4

No. If parameter for VoLTE release during endc is False then both can definately work together.

Samsung Huawei Nokia all have such setting.

5

Ok, so it’s controlled by switch at gNB end to have VoLTE call coexistence with NSA.

6

Switch at eNB, not at gNB.

7

Thanks I will check in parameter.

8

For ongoing EN-DC call if user dial MO call and VoLTE call setup then I seen SCG cell release immediately once QCI1 setup.

Is it network controllable or not?
Why to release SCG cell? Any benefit?

9

NSA ENDC, QCI 1 is not allowed for 5G bearer split.
VoLTE just run on 4G bearer.
So, SCG is released.