Huawei do not have DL SINR counter, but Nokia has (DL SINR counter like DL_SINR_DIST_WB_BINx).
with range to 30db.
Actually, I think that UE just map SINR to CQI and report CQI only, not report SINR.
Sometimes to collect MR data for coverage evaluation, it require turn on some switch.
eNB will ask some UE to periodic report rsrp/rsrq/sinr.
But not for scheduling.
In 5GNR at least, both PUCCH, PUSCH SINR are accounted for in UL.
They take it for DL Scheduling purposes.
DL SINR is something particular. Companies can become secretive on it.
Different RF Architectures can behave really differently with same DL SINR.
But I see the value of having an estimate on gNB for Mopbility purposes.
Exactly, only UL related measurements are used by eNodeB for any kind of purpose and is available in the statistics or traces.
If someone has to estimate DL SINR then better look at the CQI from the statistics which is reported by UE to the eNodeB.