5G UE does not report inter-frequency neighboring cell measurements

5G NR
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1

Hi Experts,

In an Rel.15 SA scenario, I’m trying to configure (RRC Reconfiguration) an UE to report measurements about inter-frequency neighboring cells.

The MeasConfig includes 2 measID related to 2 different MeasObject (1 for the serving cell and the other for the neighbor one). The reportConfig is configured as periodical for both.

The 2 MeasObjects include info for ssbFrequency, ssbSubcarrierSpacing, referenceSignalConfig, quantityConfigIndex and smtc1.

But the UE only sends the periodical report including only the measID configured for the servingCell. No reports are sent for the neighboring.

Looking at the UE Capabilities the relevant measAndMobParameters are supported.
I’m not understanding how the UE shall get the synchro with the inter-frequency neighboring cell to perform the measurement (or to trigger an A-Event for handover).

Can anyone help me to understand?

2

UE likely needs measurement gap specifically if there is no CA configured

3

Thanks for your replay O.B.
Including measurements gap the UE sends a report for each measID but it is still not reporting the measurements for the neighboring inter-frequency cell.

From TS 38.133 sec 9.1.3.2a the UE shall monitor 7 NR SSB inter-frequency carriers configured by PCell.
Are these SSB inter-frequency carrier the ones configured by SIB4 in the interFreqCarrierFreqList?

4

i am facing same issue

5

I have filled out the MeasGap in RRC Reconfig msg but am still not getting neighbor information.

6

@Matt @rohan
The measgap, SMTC and the period of the reportconfig must be aligned with the slot of SSB of the neighbor

7

@O.B @rohan
What I’m not understanding is if SIB4 is mandatory to let UEs to perform inter-frequency measurements.

8

SIB4 for idle mode measurements to be able to perform cell reselection