RRC setup in L2100 only sudden degradation

Hello Experts,
We face an strenght problem in our network.
Suddenly only L2100 in many cells degraded in RRC setup.
And pmrrcconnestabattreattmos increased.
Anyone has idea?
Vendor is Ericsson.

Maybe some maintenance window activity.
Check any CORE NETWORK activity that affected RAN side.

I can see RRC ReEstAtt increased and i guess not sure, might be some areas impacted due to EarthQuake due to people movement.

This looks very much the same when electrical tilt is reset to zero: more RRC attempts and RRC success rate is degraded.
Make sure on L2100 you have not lost all electrical tilts after an upgrade or other OSS intervention.

Please let us know the root cause.

Please also share RRC failure cause.

I don’t know Ericsson counters very well but it sounds like ReAttempts due to UE Side.
If thats true it means UE didn’t respond to Msg4 or it had issues during attach procedure and started new RRC procedure.
Check you Msg4 failure reason.
Its generally a coverage issue.

Ok, Thanks, we need DT analysis.
This issue happened for around 1000 cells simultenously.
We have three LTE layers, it happened only for L21.
L26 and L18 are fine.

DT is expensive :slightly_smiling_face: you can check theory by just looking at counters.

Higher layer, higher interference, more limited coverage.

L26 is higher but it is fine… :frowning:

Yes true, missed that.

pmRrcConnEstabAttReattMos: (description) --> The total number of RRC Connection Request attempts that are considered as re-attempts for Establishment cause Mobile Originating Signaling.

Thanks. This is what I thought as well… points to Msg4 reception issue.

General advice (as it helped me alot in my days): always check the call flow sequence to see where issue is happening (prach, rrc, security, attach…) and try to guess what might have caused issue (ue or eNB not responding). Then see if vendor supports any counters to check the area of interest. Follow that with actions you’d like. :wink: