HOSR degradation after ANR enabled

4G LTE
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1

Hello Dears,

HOSR degraded after enable ANR over 100 new sites, S1 & X2 attempts increased after active ANR.

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image1080Ă—460 58.7 KB

Only cells in the same eNB was defined to each other (manually).
Checked many sites, found X2 fault alarm, it happened frequently.

Any comments?

2

It’s normal behavior.

3

Any suggestions to improve HOSR?

4

ANR may cause bad effect if configuration ANR is not good.
Firstly you should check worst cells hosr, worst relation A->B hosr.
Pci conflict, confusion may also.

1 Like
5

What is the metric used for 4G_Intra_Rat_SucessRate calculation?

Verify what are the relations with more failures it will help you to identify reasons as PCI confusion, overshooting cells…
Bit weird for me in your graph we have HO_SR > 0% with no attempts on S1 before the feature activation.

1 Like
6

Check Ho stats, if there is any unnecessary relation like 4th tier cells or overshooting cells remove that relations using targets tilts or block that relation.
As well as check our cells TA.

1 Like
7

( [L.HHO.IntraeNB.IntraFreq.ExecSuccOut] + [L.HHO.IntereNB.IntraFreq.ExecSuccOut] ) / ( [L.HHO.IntraeNB.IntraFreq.ExecAttOut] + [L.HHO.IntereNB.IntraFreq.ExecAttOut] ) * *{100}

8

Metric is OK.

9

what is the alarm details, any description

10

Try to disable ANR, delete Relation, Activate ANR again with this script: (it will give you fresh relation on your enodeB)

MOD ENODEBALGOSWITCH: AnrSwitch=IntraRatEventAnrSwitch-0&IntraRatAnrAutoDelSwitch-0;
MOD GLOBALPROCSWITCH: X2BasedUptNcellCfgSwitch=ADD_NCELL_CFG_SW-0&MOD_NCELL_CFG_SW-0&DEL_NCELL_CFG_SW-0&ADD_FREQ_CFG_SW-0;

RMV EUTRANINTRAFREQNCELL:;
RMV EUTRANINTERFREQNCELL:;
RMV EUTRANEXTERNALCELL:;

MOD ENODEBALGOSWITCH: AnrSwitch=IntraRatEventAnrSwitch-1&IntraRatAnrAutoDelSwitch-1;
MOD GLOBALPROCSWITCH: X2BasedUptNcellCfgSwitch=ADD_NCELL_CFG_SW-1&MOD_NCELL_CFG_SW-1&DEL_NCELL_CFG_SW-1&ADD_FREQ_CFG_SW-1;

11

need to check:

  • ’ O&M controlled Neighbour Relation Attributes’

  • rogue eNodeB uses legitimate mobile devices as a covert channel to launch attacks against SON enabled LTE networks.
    this cause X2 signaling flood when more cells are impersonated

12

Hi.

There is a hug increase of attempts, maybe is a RF problem.
First try with “ANR over distance” to limit neighbords relationship