ANR LTE creating X2 and relationships very far (>100 km)

Mobility
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1

Hello Experts.
In our network, ANR LTE creates X2 and relationships very far (>100 km).
Do you know why please?
You have already meet a similar case?
Thanks a lot

2

What is cellradius?
Because the problem is the distance of the ANR (>100km) so probably the extended coverage feature is enabled.
How is cell radius configured?

3

Cellradius is OK.

4

Any idea please?

5

For example: before ANR added neighboring site A with site B due to handover attempt.
Later you reuse site B to other location C very far, same site id, pci.
ANR setting conditions to delete neighbors with few attempts, time is too long. So, anr still keep the relationship A & C.

6

Id of site is unique. And anr taking ecgi to add X2

7

You can check log when ANR added this far neighbor. ID is unique but maybe you reuse site To far location, keep id.

8

Any chance to blacklist the nbr ? I dont remember the details…

9

Yes we can bl but its not a good solution

10

Most likely due to same PCI sites one close and other very far.
eNB does query the ECGI and gets the ECGI of tbe far site and adds X2.

1 Like
11

Hello @Khurrambilal01, ECGI is unique on the network.

12

As far as I know, ANR creates X2 relationships between LTE sites based on measurement reports sent by the phones.

So I guess a misbehaving phone could result in unlikely neighbors getting registered in the eNodeB.

BR,
Michael A

2 Likes
13

ANR can be based also on periodic measurements

Check your rádio planning. You might be having an enodeb overshooting

15

Hello
What do you mean?

16

The Automatic Neighbor Resolution does not happen because eNB A sees the radio signal of eNB B.

ANR happens when a mobile phone sends a measurement report to eNB A that indicates eNB B is also visible.

So it comes down to the accuracy of the measurement reports from the phones.