2 cells with same eARFCN and PCI

Hi LTE Experts,
I have one complicated scenario:
We have 2 cells with same eARFCN 300 and same PCI 100.
My source cell getting worse and target is good.

Need to understand whether my UE will send MR for A3/A5 or not in this case considering PCI is same.


UE cannot distinguish between two cells if both have the same PCI and frequency bands -> UE only consider as 1 cell, not 2 cell, so no A3 report.

But it is possible that 2 cells can have same eARFCN and same PCI.

Please check if report eCGI feature is available in your network, eNB will ask us to report target cell eCGI in case of PCI conflict.

Yes, I remember 4G allow to configure 2 cells same PCI/Freq as neighboring, 3G not allow.
But OSS will display alarm “PCI conflict”.

If both source and target cells are of same freq and same PCI, then one normal neighbor addition is not possible.
UE can certainly measure neighbor and report neighor cells, but eNB cannot add them in neighbor relation table.
In that case, eNb can ask UE to meausre eCGI of nbr cell, after that HO can be possible.
But, I don’t have any evidence of this scenario, because in network such situation is called PCI confusion, and it it is resolved by SON.

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eCGI is asked UE to read, but I think only in case PCI confusion where 2 neighbors same PCI, UE report A3-rsrp with PCI but enodeb do not know which target eNodeB.
So that, eNodeB will know which target eNodeB to send HO-request.
Here is PCI conflict, 2 cells same PCI, I think UE can not distinguish 2 cells and not report anything.

Ok thanks. So you mean UE will send MR for A3/A5?
But I didn’t lead to any ho completion I mean execution phase not successful.

I think CRS for 2 different cells are scrambled with different identity.
UE can certainly differentiate between these 2 cells with same freq and PCI.

Ye should be.

If eCGI acquisition is successfull then HO will also get success.

No, cell reference signal is just to decode PCI.

Yes PCI is OK.
Let me check Scrambling.

Flow of ANR is like:

  1. UE report strongest cell
  2. Then CGI of that cell
  3. Neighbour will be Added

So once NBR is added then there will no issue in HO get successfull.