RRC Failure reasons

Hi Experts,
What could be the reason of RRC connection failure and RRC reestablishment failure?

Experts please have glimpse over that


RRC connection failure cause: radio resource congetion (PUCCH, SRS, user number), poor radio link
RRC reestablishment failure cause: no UE context

What could be issue in RRC reestablishment reject or failure in LTE?

  • Reject: UE context not available
  • Failure: many reasons like poor RF, etc.

Missing neighbour relation.

Yes because of that UE context exchange will not happen.

Reject-CAC failures also. (call admission control)

Huawei FD, it has flow of CAC.
LTE check such as pucch, srs… one by one.

Inter-Modulation Interference and channel unbalance leading RRC failure due no reply

Number of RRC Connection Reject messages sent to the UE in a cell ( enodeB Faulty alarm ,CPU load , number of users exceed )

Hi @sadanandk2, I just want to know in what cases UE context not available to enodeb or MME

In case of missing neighbour the new eNodeB (where UE does re-establishment) cannot retrieve UE context from old enodeB due to missing X2.
So dropped is pegged as an MME drop but in reality is an RF/RAN drop.

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It can be case of HO ok, but in normal case where RRC reestablishment reject, in that case what would be reasoN for UE context not available?

Missing X2 between those 2 eNodeBs.
Or congestion could be cause of rejection.
Congestion due to lack of resoruces like SRS, PUCCH, etc.