Is there inter RAT mobility for 5G NSA network?
IRAT as in 5G NSA to 3G/2G: Yes, 5G NSA to 5G SA : Yes
Inter RAT HO to LTE valid for SA option 2 only.
I don’t think NSA support Inter RAT HO to LTE.
Yes, only SCG addition and Release.
Can’t call it HO.
I think in NSA mode, if 5G signal is poor, Menb will release Sgnb and UE is in 4G only.
After that, if 4G signal is still poor, it may be intra-rat hsndover to another 4G cell.