KPI+monitoring+rules+-+DCR

Soc Classification level Presentation / Author / Date 1 © Nokia Siemens Networks

DCR- analysis, dcr_32a

Sum (a.tch_radio_fail + a.tch_rf_old_ho RF Reasons+(a.tch_abis_fail_call - d.FACCH_CALL_SETUP_FAIL_PAGING) ;Ref 1 + a.tch_abis_fail_old Abis -interface+a.tch_a_if_fail_call + a.tch_a_if_fail_old A -interface+a.tch_tr_fail + a.tch_tr_fail_old Transcoder+a.tch_lapd_fail + a.tch_bts_fail + a.tch_user_act + a.tch_bcsu_reset Other reasons+a.tch_netw_act + a.tch_act_fail_call) Other reasons – sum(b.tch_re_est_assign) Call re-establishments

100 * ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sum (a.tch_norm_seiz) Calls started directly in the cell

+sum(c.msc_i_sdcch_tch + c.bsc_i_sdcch_tch + c.cell_sdcch_tch) DR calls - sum(a.tch_succ_seiz_for_dir_acc) ;ref.2 + sum(a.tch_seiz_due_sdcch_con) FACCH call setup calls - sum(b.tch_re_est_assign) Call re-establishments

•Counters from table(s): a = p_nbsc_traffic b = p_nbsc_service c = p_nbsc_ho d = p_nbsc_res_avail •Ref 1; The counter002072 FACCH_SETUP_FAIL_DUR_PAGING used to compensate the counter001084 TCH_ABIS_FAIL_CALL that is updated faultily after activation of FACCH •Ref.2; Compensation needed since in case of Direct Access to super reuse TRX thetch_norm_seiz is triggered in parallel with cell_sdcch_tch.

Segment related problems: There might be some problems with tch_norm_size if used on

BTS level and the BTS is part of the multisegment.


DCR >2% and DCR_count > 10#

Drops due to

RF reasons

DCR > 2% &

DCR_num >10Drops due to

A-interface

Drops due to

Abis

Drops due to

Transcoder

Drops due to

Other reasonsNo

No No NoYes

No

Case Closed

RF Abis A TR Other

Yes Yes Yes Yes Yes

No


RF reasons (p_nbsc_traffic_tch_radio_fail, p_nbsc_traffic_tch_rf_old_ho)

RFNo

Yes

TRX is broken (sample distribution is somehow strange, for example only quality 4 samples)

Change new frequency based on interference matrix

No

Check RX Statistic table or ND report 204, UL/DL quality/level distribution. Any Bad Quality problems = Lots of samples in good signal level and bad quality?

Yes

TRX / combiner is broken, for example only <-100dBm level samples

Coverage problems. Improve coverage

No

YES Change the TRX

YES Change the TRX /

combiner

No

Check TA statistics and Check all Neighbors. If lots of long distance samples and only nearest cells are neighbors, may be some neighbor cells are missing

No

Check HOs to adjacent cells, Any bad HO problems to any adjacent cells?

Neighbors are missing

YES Add neighbors

Check all HO parameters, any HOC parameter problems?

YES make corrections

No

Check if HO fails are due to MSC/ BSC border. If bad values, check borders. Area optimizing?

No

Yes

TRX / combiner is broken

Make parameter corrections

Check cell parameters, discrepancies? ND_parameters

DCR still too high

No

yes

Case closed

Check all the alarms

1* P_nbsc_rx_statistics

2* P_nbsc_ho_adj

3* P_nbsc_power

1* 1* 2*

3*

2*

HOC

hfr_58, hfr_59

Add LNA or new sites

Check RX Statistic table or ND report 204, UL/DL level distribution. Any Bad Level problems = Lots of samples in bad signal level?

Check blocking in target cells. If blocking, add capacity to blocked cells

Capacity added

Yes

blck_19, blck_20

No blocking

ND 232

ND 150

No

hfr_58, hfr_59


Abis reasons (p_nbsc_traffic_tch_abis_fail_call, p_nbsc_traffic_tch_abis_fail_old,p_nbsc_res_avail_spare002072 = p_nbsc_res_avail_facch_call_setup_fail_paging(S12))

Abis

yes

activate

Investigate alarms. If problems are not solved, activate abis trace

All Alarms are checked and abis trace is done

Investigate log files.

Alarms are solved

no

Trace has been measured long enough. Any problems found

No

YesMake corrections

Any improvements,

NoYes

Case closed

Check CC table, which phase drops are happening

Drops are happening in the release phase

check the BTS release and the timer 3109 expired values. >BTS version 6.1 3109 expires in a BSC while waiting for the Release indication.These are seen as abis drops.These are not real drop not real abis problems

yes

no

no

Still high drops in Abis interface

Yes

Check the parameters related to abis. BSC parameters

1* P_nbsc_CC

1*1*

If not long enough, activate another trace

Drops are checked and are not real abis problems

• Abis reason can check p_nbsc _CC table where drops happens

• Can check the 3109 timer (not real abis problem)


A- reasons (p_nbsc_traffic_tch_a_if_fail_call, p_nbsc_traffic_tch_a_if_fail_old)

A

yes

activate

Investigate alarms.If problems are not solved, activate A trace

A interface problems. Alarms are checked and A interface trace is done

Investigate log files.

Alarms solved

no

Any problems found.No

YesMake corrections

Any improvements

NoYes

Case closed

yes

Check ET lines in the BSC and transcoders /TCSM. Any problems

Still A drops or problems

Check if there are errors, when MSC assign some pools

No problems

Repair ET lines

Are parameters and timers checked

Check that sccp counter values are correct

Check that A parameter values are correct

Check that A timer values are correct

Checked

no

ZNMI:C;

ZNRI:NA0;ZNNI:1,C;

ZOCI:1;

Make corrections

no

yes

Any protocol error unspecified? Check bug possibility


Transcoder reasons (p_nbsc_traffic_tch_tr_fail, p_nbsc_traffic_tch_tr_fail_old)

TR

yes

activate

Investigate alarms.If problems are not solved, activate abis trace (remote TR failures)

TR problems. Alarms are checked

Investigate log files.Check if failures are following some PCM either in Abis or A and fix accordingly. Before Implementing HR in the BSC & cells it is must to reconfigure the A interfacelinks to support Dual Rate. Otherwise it will give rise to high call failures mainly TCH_TR_fail due to mismatch of coding between TCH in Radio & "A" interface.

Alarms solved

no

Any problems found

No

YesMake corrections

Any improvements

NoYes

Case closed

Check CC table, in which phase TR drops are happening

Check TR codec specific fails, run

ND report 247,transcoder failure report

Check TCSM statistics, run ND 523. Check also ICTF parameter

If release phase, not real drops

Still TR drops or problems

no

yes

Not release phase

If drops are happening in some specific codec HR/FR issue investigate or is it more like individual TR problem

If there some problems with TCSM investigate. ICTF, how many fails are ignored

donedone

Check that TR parameters are correct. If not, correct these

1* P_nbsc_CC

1*Release phase Not done Not done


Other reasons (p_nbsc_traffic_tch_lapd_fail, p_nbsc_traffic_tch_bts_fail, p_nbsc_traffic_tch_user_act, p_nbsc_traffic_tch_bscu_act, p_nbsc_traffic_tch_netw_act, p_nbsc_traffic_tch_act_fail_call)

Lapd failsOther User act, bscu, act fail

Still lots of other drops

No No No No

Yes Yes Yes Yes

Yes

No

signalling fails or PCM fails. Check transmissio / parameters

bts fails

TRX or BTS fails. Check that BTS/ TRX are working properly

Netw act

Configuration problems, check configurations

Case closed

Resets or act fail channel failures

Check all the alarms

KPI+monitoring+rules+-+DCR

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