eNB replies to MSG2 but no MSG3 received

[eritelecom]

Hi lads

I have some cases where eNB (LTE) is replying to MSG1 (RACH) (MSG1->MSG2 successful) but no record for MSG3 (no RRC request recieved at all) !

can anyone explain ?

[wolverine]

Ghost preambles perhaps.

[eritelecom]

what is the reason behind ghost preambles ?

[dennielone]

Hi lads

I have some cases where eNB (LTE) is replying to MSG1 (RACH) (MSG1->MSG2 successful) but no record for MSG3 (no RRC request recieved at all) !

can anyone explain ?

>>>
Is that a contention-based RACH procedure or not ? If it is a contention free RACH procedure, it may look good.
In case it is a contention-based, may be UE lose signal or reselect to other RAT. Or the UE move far away from eNB and the MSG3 is too weak for eNB to detect.
There are many reason. You may check further. For example, only happen in one phone ...

Thanks & regards
Dennielone

[basit_engineer]

please to check the RSI plan in the problematic cell and try also to downtilt if any overshooting.

[eritelecom]

the pb here is that eNB receives thousands of MSG1 and replies to them but zero MSG3 !! so if there is any pb in rout sequence planning it should have some replies at least no zero

[eritelecom]

any feedback please lads ?

[agenov]

what is the cell radius defined for that cell ? does it correlate to the expected serving distance ..>

br
alex

any feedback please lads ?

[wciagatune]

what is your current set value for Nominal power for EU PUSCH TX