I am facing an issue with an Ericsson IBS site and would appreciate your guidance.
The site has both a Passive DAS and an Active DOT system:
N41 is deployed on the Passive DAS (SISO).
Two N78 layers are deployed on the Active DOT system (4x4 MIMO).
In NSA open mode, the UE is establishing NR CA with N78 as the Primary Carrier and N41 as the Secondary Carrier. Since the secondary carrier is on the Passive DAS (SISO), this is impacting the overall EN-DC DL throughput.
Our objective is to have both the Primary Carrier and Secondary Carrier on the N78 layers (Active DOT) to maximize DL throughput.
Is there any Ericsson parameter or CA prioritization setting that can influence the NR secondary carrier selection to prefer N78 over N41?
I am aware that disabling scellCandidate on N41 would prevent it from being selected as the secondary carrier. However, this would also impact 3CC operation in SA mode, which we want to avoid.
Has anyone encountered a similar scenario or found a solution that prioritizes N78 in NSA while preserving 3CC functionality in SA?
scellCandidate and the SCell thresholds sit on the frequency relation, and both EN-DC and SA CA evaluate the same relation, so suppressing n41 for NSA hits SA 3CC too.
First confirm it’s not a capability issue: check UE-NR-Capability for the intra-band n78+n78 EN-DC combo (not just inter-band n78+n41), and that n78+n78 is enabled node-side with both carriers as mutual SCell candidates. Fast proof: band-lock a test UE to n78 and see if n78+n78 forms end to end. If it does, it’s candidate ranking — on a passive DAS indoors n41 sits at strong RSRP and qualifies first every time.
Then, cleanest first:
addSCellCandThresh on the n78→n41 relation, so n41 only qualifies at low RSRP. Note it’s usually SS-RSRP index per TS 38.133 (dBm ≈ index − 156), not raw dBm — check Range/Unit in the MOM first. Still applies to SA.
A per-usage CA scoping attribute on the frequency relation (EN-DC vs SA), if your release has one — the only clean separation. Confirm the exact name in CPI/ALEX for your baseband/release.
coverageIndicator won’t help — it’s for mobility/reselection ranking, not CA candidacy.
Worth measuring SA 3CC throughput with and without n41 first; if its SISO contribution is small, suppressing it globally may cost less than splitting NSA from SA.
endcB1MeasPriority is NSA-only, so it won’t touch SA 3CC — worth testing.
But it controls PSCell selection, not SCell candidacy, so it probably won’t stop N41 being added as SCell. Check in Alex what -1 means (excluded vs lowest priority).
Also: addSCellCandThresh is 1–100 %, not RSRP index — correcting my earlier post. Raise to 80–90 on N78→N41, removeSCellCandThresh 70–75.