Identify PCC and SCC from Log

In this NR CA (N1+N78) what will be PCC and SCC?
Is it possible to know that from log?

I think you can check which band cell got added recently will be the SCC.

LTE B3 is PCell
NR n78 is PSCell
NR n1 is SCell

Between both NR bands, why N78 is PCC and N1 is SCC?
Because N78 has DL and UL and N1 has only DL?

I found this:

PCell Vs SCell:

  • PCell always have both Uplink (UL) and Downlink (DL).
  • SCell always have DL (While activated) but may or may not have UL.

Is it a role?

Only be aware that CA in UL not too many devices support it yet.

Yes, correct.

I think for this UE, DL CA n78+n1 anyband can be pcell.
But for UL CA, n1 not support, only n78 support, it can be n78 intra-band UL CA.

Pcell, pscell, scell, spcell this we know.
NRpcell, NR pscell, NR scell: New terminology

Friends spcell = pcell + pscell.
But still for NR you can see spcell as terminology.

Why spcellconfigcommon and spcellconfigdedicated used for NR?
As spcell= pcell + pscell

I disagree for the said band combination. n1 cannot be pscell becuse it do not have UL support.

Log do not say: n1 do not have UL.
It just say: n1 do not support UL CA

Yes, consider this as a rule.


Now another doubt:
eNB sent B1 Event to UE only for N1 and received the measurement for N1 also.
Is it possible the eNB send the SGNB ADD REQ with this combination above without B1 event and result for N78?


Like Blind Sgnb addition?
Without knowledge from UE which n78 cell available?

But how can add NR without the MR and so without the PCI for n78?
To which gNodeB the enodeB will send scg addition request for n78?

I too have the query, not an answer :sweat_smile:

I have seen this behavior on LAB tests. It is possible, but unadvised.

Blind addition is possible with pre defined lte-nr co relation.
NR is added at the time of initial context setup.

But he just mentioned that B1 MR is just for n1 not for n78.
So its should be set for n1 not for n78.

Yeah I saw that.
But I am saying in general that blind addition is well supported by vendors.

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My Blind is OFF.
I am using B1 event.
This is reason to the question?
How can eNB send it to gNB without meas N78?

UE has N1 and N78 but eNB send Meas only to N1 and received that.
After that How eNB sent ADD SGNB REQ with N1_N78, without N78 meas?

Yes. eNB sent and received only N1 and after that sent SGNB ADD REQ with a N1_N78 combination.


After that, eNB sent SGNB ADD REQ with N1_N78 without B1 event sent and received to N78.