Deciding factor for sCellIndex definition

Hi Folks,

Recently I observed in a few log files, the sCellIndex for ENDC 5G-NR SCG is configured with :

  • Case1: sCellIndex 2,3,4
  • Case 2: sCellIndex 8,9,10
  • Case 3: sCellIndex 9,10,11

For SCC1, SCC2, and SCC3 respectively in a 4CA configured network.

Here the spCellConfig uses 1,7 & 8 as servCellIndex respectively.
One sample (case3) is shown below: (9,10,11 case)

    servCellIndex 8,

            *sCellIndex 9,*
            sCellConfigCommon *
    sCellIndex 10,
    sCellIndex 11,

Can anyone help me to understand what is the deciding factor for this type of index definition?
If life is normal we expect scellindex 2,3, and 4 and PScell in servCellIndex as 1.
Is this defined by vendors like Nokia, Ericsson or Huawei?
If so, is there a technical reason of choosing the above 3 cases?

Any help on this topic is highly appreciated.

I can make a wild guess: If Scell 1 to 6 is used by LTE for 7 CA, there is possibility for 5G SCG PSCell will be 7 and SCG SCC1 can take values from 8,910…and so on for Eg :may be a multiradio e/gNB
But still I see for case 3, PSCell taking value 8, and SCG scc1 from 9,10,11…which makes me confused to even guess the above point.