1© Nokia Siemens Networks RNO / Wind 17/10/2007 - NMI Confidential RNO Wind Part I.

1 © Nokia Siemens Networks RNO / Wind 17/10/2007 - NMI

Confidential

RNO WindPart I

Confidential


Part I - Content

Active set usageAdjs Optimization

PollutionPollution Identification

AccessibilityDownlink and Uplink Admission Control algorithm (not enough radio or transport resource, UE-

BTS synchronization problems) and Congestion

Confidential


Active Set Usage

Confidential


Active Set Usage

M1013 (These counters are referred to cell addition and cell replacement – no target for deletion)

Absolute Value must be considered not Failure Rate!

Confidential


Active Set Usage

High # out-going attempts?

High # out-going fails for a defined ADJS?

In – out pairs?

Zero attempts?

Major

Failure ADJS

Ping-Pong

Yes

No Adjs

Low used Adjs

Yes

Yes

Yes High # fails for a source?

Failure WCEL

Yes

Unbalanced WCEL

High # attempts for a source?

Unbalanced ADJS

Yes

Minor

Minor

Filtering over attempts must be taken into count that:

- statistical data must stabilized over time.

- traffic distribution is not considered and a double-check to localize the event and DT feedback is required to understand if fenomena is traffic driven or cell dependent

Filtering over failure in absolute terms it is possible to find the major critical events

Confidential


Active Set Usage

Filtering criteria:

Major - High number of failures for a defined out-going adjs (failure ADJS)

- high number of fail for a defined source (failure WCEL)

Minor- high number of attempts in-comig and out-going for a defined pair with occasional failure (ping-pong)

Filtering action are required to find bi-lateral corrispondence - very low number of attempt with failure (low used adjs)

- zero number of attempt for declared adjs– stabilized value (no adjs)

- high number of attempts with occsional failure for an out-going adjs (unbalanced ADJS)

Either in-coming or out-going condition is sufficient

- high number of attempts with occsional failure for a defined source (unbalanced WCEL)

Confidential


Failure ADJS

Failure ADJS

Analyze RSCP from DT & NWP coverage plot considering inter-site distance

Target act as polluter?

Down tilt

Yes

Analyze Ec/No from DT

Down tilt possibile?

DERR cell

Yes

Ec/No offset

Once anlyzed the RSCP, the coverage plot taking care to the evaluation of intersite-distance, it is easy to understand if target can be used.

If not only down tilt is possible or DERR (ADJS object Paremeter) cell to avoid the failure during SHO.

Down tilt must be carefully anlyzed.

If from Ec/No the cell can be recovered an individual offset or filtering (ADJS object Parameter) can be introduced to fovourite it

Very low value of RSCP that not allow the adjs to be used

…Attempt Fail Attempt Fail Attempt Fail Attempt Fail

Source_cell_A 2 1 23 1 442 34 4 0Source_cell_B 1 0 11 0 53 25 345 0

…Source_cell_Z 322 54 15 0 2 0 12 0

Target_cell_A Target_cell_ZTarget_cell_CTarget_cell_B

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Failure ADJS – Individual Ncell Offset

time

P CPICH 1

P CPICH 2

P CPICH 3

Reporting Range

Reporting Event 1B

Reporting Event 1A

AdjsEcNoOffsetto modify measurement reporting behaviour. Effectively 'moves' cell border (shrinks or enlarges cell)

Enlarging Cell 3 by x dB

Ec/Io

Confidential


Failure ADJS – Forbidding Neighbour Cell

Time

P CPICH 1

P CPICH 2

P CPICH 3

PCPICH3 is forbidden to affect the reporting range as its quality is quite unstable.

Reporting

Range

AdjsDERRto forbid a cell from reporting range calculation in some instances

Ec/Io

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Failure WCEL

KPI(1) ?

Failure WCEL

Tune 1A

Yes

KPI(2) ? Tune 1C

Yes

Analyze Ec/No &BLER from DT & NWP coverage plot considering inter-site distance

WCEL polluted/interfered?

Yes


Pollution/Interference

Most of the Target failure during the 1A or 1C event.

Once anlyzed the Ec/No, BLER, the coverage plot taking care to the evaluation of intersite-distance, it is easy to understand if the WCEL is interferered/Polluted

If not, two KPIs allow to separate the dominant contribute among the 1A and 1C.

Relaxing the parameters an improvement should be achieved

The following gives the number of attempts per event

RT Services

KPI(1) = M1007C10 CELL ADD_REQUEST ON SHO FOR RT TRAFFIC

KPI(2) = M1007C12 CELL REPL_ REQUEST ON SHO FOR RT TRAFFIC

NRT Services

KPI(1) = M1007C27 CELL ADD_ REQUEST ON SHO FOR NRT TRAFFIC

KPI(2) = M1007C29 CELL REPL_REQUEST ON SHO FOR NRT TRAFFIC

The failure rate for all the procedure can be estimated as well

ADD(REPL)_ FAIL_ONSHO _FOR_x / ADD(REPL)_REQ_ON_SHO_FOR_x + ADD(REPL)_ FAIL_ONSHO _FOR_x

M1007C14 / M1007C12 + M1007C14

M1007C36 /M1007C11 + M1007C36

M1007C30 / M1007C27 + M1007C30

M1007C37 / M1007C28 + M1007C37

M1007C31 / M1007C29 + M1007C31



…Source_cell_Z 322 1 15 0 2 0 12 0


Confidential


Failure WCEL - 1A

RNC

Strongest CPICH in AS:

time

Ec/Io

P CPICH 3

P CPICH 1

P CPICH 2

1A

AdditionWindowdetermines the relative threshold used by the UE to calculate the reporting range of event 1A. The threshold is either relative to the CPICH Ec/No measurement result of the best active set cell (0), or to the sum of active set measurement results (<>0)

AdditionTimedefines the 'time-to-trigger' interval between the cell entering the reporting range and the UE sending the measurement report to the RNC with the 1A event

AdditionReportingIntervaldefines the period of time that the UE wait, if the RNC is unable to add Ncell to AS, before sending further reports periodically, with interval AdditionReportingInterval, until the Ncell moves out of reporting range, or RNC adds Ncell to AS.

MeasurementReport

Add tothe AS?

no

ActiveSetWeightingCoefficientis used to weight either the measurement result of the best active set cell (0) or the sum of measurement results of all active set cells (<>0)

Confidential


Failure WCEL - 1C

time

weakest CPICH in AS

Ec/Io

P CPICH 3

P CPICH 1

P CPICH 2

P CPICH 4

AS has 3 cells

ReplacementReportingInterval

If the RNC is not able to replace the active cell with the monitored cell, the UE continues reporting after the initial report by reverting to periodical measurement reporting. The parameter Replacement Reporting Interval determines the interval of periodical measurement reports when such reporting is triggered by the event 1C.

ReplacementWindow

determines the margin by which the CPICH Ec/No measurement result of the monitored cell (MNew) must exceed the CPICH Ec/No measurement result of the an active set cell (MInAS) before the UE can send the event 1C triggered Measurement Report to the RNC: MNew >= MInAs + ReplacementWindow / 2

ReplacementTimeDefines the period of time the monitored cell must continuously stay within the reporting range before the UE can send a Measurement Report to the RNC in order to replace an active set cell with the monitored cell (event 1C).

MeasurementReport

RNC

ASupdate?

no

1C

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NO ADJS

No Adjs

Remove ADJS

Zero attempts?

Statistic Stable?

Yes

Repeat Analysis

Yes

DT analysis for the Adjs

Comparing the ADJS plan provisioned into the network with the M1013 matrix, it is easy to find if one declared ADJS is not used (not present in the list)

Statistic data must be stabilized before decide to remove it and DT analysis can help n estimating the amount of residual noise if down tilt is not possible


Source_cell_A 2 1 0 - 442 34 124 23Source_cell_B 0 - 11 0 53 0 345 0

…Source_cell_Z 322 1 15 0 2 0 12 0


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Low used ADJS

Low used Adjs

Remove ADJS

Analyze DT result and NWP data

Monitored Qual from DT acceptable?

Alter. ADJS present?

Yes

Interference evaluation

Yes

ADJ Offset

It is not difficult in live network to find some pair working with very low

For low used ADJS has to be intended and ADJS that has few number of attemps in one day (e.g <3)

with occasional failure.

The ADJS removal has to be considered as the last option, after the quality has been monitored by drive test result, considering the overall capability of the target to be recovered (e.g. inter-site distance, power budget) and other options are available for that area.

Statistic data must be stabilized before decide to remove it and DT analysis can help in estimating the amount of residual noise if down tilt is not possible



…Source_cell_Z 322 1 3 1 2 1 123 20


Confidential


Unbalanced ADJS

Unbalance ADJS

Ec/No offset

Analyze RSCP from DT & NWP coverage plot considering inter-site distance e traffic distribution

Target act as polluter?

Down tilt

Yes

Analyze Ec/No from DT & evaluate unbalance


DERR cell

Yes

Attempt over the same UE?

Yes

An high number of attempt could be an indication of a problem and even in case of the failure is not associated an evaluation is required.

The key point is the inviduation of the attempt distribution, that in case are not justified but partcualar populated area, coluld generate lot of signalling.

The attempts could be genarated by 1B event ever the same UE not counted in the M1013.

The possibility to recover the ADJS is the favourite option and the down tilt carefully analyzed considering the failure associated.

No action required


Source_cell_A 54 3 345 10 23 1 124 5Source_cell_B 25 1 11 0 137 3

…Source_cell_Z 32 2 45 2


Confidential


Unbalanced WCEL

KPI(1) ?

Unbalanced WCEL

Tune 1A

Yes

KPI(2) ? Tune 1C

Yes

Analyze RSCP from DT & NWP coverage plot considering inter-site distance and traffic distribution

WCEL interfered

polluted?

Yes


Interference / pollution

Attempt over the same UE?

Yes

No action required

An high number of attempt could be an indication of a problem and even in case of the failure is not associated an evaluation is required.

The key point is the inviduation of the attempt distribution, that in case are not justified but partcular populated area, coluld generate lot of signalling.

The attempts could be genarated by 1B event ever the same UE not counted in the M1013.

The possibility to have an interference/pollution increase respect to the unbalanced ADJS.

The optimization should be performed at WCEL level

The KPI reported are the same of Failure WCEL





Confidential


Ping Pong

Ping-pong

Analyze RSCP from DT & NWP coverage plot considering inter-site distance

One of them act as polluter?


Comparable value?

Histeresys using

Ec/NoOffset on the pair

Not stable, Fading?

Filtering

Yes

Yes

Down tilt


DERR cell Yes

Yes

Attempt from the same UE?

No action required

pollution

In this particular case the high number of attempt is concentrated in a pair

From A >> B and from B >>A as in the picture

As in the previous case could be an indication of a problem and even in case of the failure is not associated an evaluation is required to avoid to use a lot signalling.

The optimization should be performed at ADJS level considering that the filtering option could get to smoother measured value





Confidential


Ping Pong - Filtering

Node B

UTRAN

RNCUE

Measurement Control [ ]

I am in the CELL_DCH sub-state

Measurement Type: Intra-frequency measurements Reporting events:1A: Event 1A triggered when CPCIH Ec/Io of the measured

cell enters UEreporting range for a defined period of time1B: Event 1B triggered when CPICH EC/I0 of the measured cell

drops outof the UE reporting range for a defined period of time1C: Event 1C triggered when CPICH EC/IO of the measured

cell enter inAS by a defined margin for a defined period of time

System Information [ ]

EcNoFilterCoefficient EcNoAveragingWindow

Applied for averaging of periodical meas. reports

Ec/NoFilterCoeffcontrols the higher layer filtering of physical layer measurements before the event evaluation and measurement reporting is performed by the UE.

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Pollution

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Polluter Detection

The best way to individuate a Polluter is the Drive Test

A feedback can come from coverage plot, RNP feedback and Counters

A polluter can be of different type:

1. PSC Pollution

Too high reuse factor for the PSC. New PSC plan is required

2. DL Noise raise

ADJS signal strength out of usage window (will be never utilized by the UE)

A down tilt or power reduction is the solution evaluating all the side effects

3. Dominant site

A dominant site over-shooting the ADJ becoming congested

A down tilt or power reduction is the solution evaluating all the side effects

Confidential


PSC Pollution

A confirm for the polluter of the first type can come from the counter

M1007C38-47 CELL SPECIFIC CPICH EC/NO - CLASS x

Pollution Criteria:

The M1007C38-47 gives an indication of Ec/No distribution value measured during event 1A . Having the distribution higly unbalanced (normally centered on class 2, 3, 4) we have an indication of a probable problem. For example unbalancing towards the scarce vaue of Ec/No but continuing to add cells to AS could give an indication of pollution

Polluted WCEL

Yes

High number of class0-3?

High number of class>6?

Not Polluted WCEL Yes

Isolated/unavailable WCEL

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DL Noise Raise

The NO ADJS and low used ADJS criteria before presented can give a confirm for a pollution of this type.

After the statistical data are stabilized, making across-check with the provisioned ADJS Plan the probable polluters are individuated.

This is obviously a cautelative estimation to be integrated and confirmed by drive test results


Source_cell_A 2 1 25 4 0 - 124 23Source_cell_B 245 23 11 0 53 0 345 0

…Source_cell_Z 322 1 3 1 0 - 123 20


Confidential


Dominant site

Filtering the M1013 pairs for the recurrent target cell with associated occasional failure we have an estimation of the probable polluters

For the polluters, originating failures a down tilt is required

Polluted Cell Criteria:

SHO over head can give a soft help in individuating cell where polluter/overshooting site can be present or where unbalanced cell criteria could apply

%1001

T_NRT_IN_ACT_SETHREE_CELL M1007C21T_RT_IN_ACT_SETHREE_CELL M1007C2

NRTN_ACT_SET_TWO_CELL_I M1007C20RTN_ACT_SET_TWO_CELL_I M1007C1

NRTN_ACT_SET_ONE_CELL_I M1007C19RTN_ACT_SET_ONE_CELL_I M1007C0

3T_NRT_IN_ACT_SETHREE_CELL M1007C21T_RT_IN_ACT_SETHREE_CELL M1007C2

2NRTN_ACT_SET_TWO_CELL_I M1007C20RTN_ACT_SET_TWO_CELL_I M1007C1


RNC_79B OverheadHandover Soft

%1001

T_NRT_IN_ACT_SETHREE_CELL M1007C21T_RT_IN_ACT_SETHREE_CELL M1007C2

NRTN_ACT_SET_TWO_CELL_I M1007C20RTN_ACT_SET_TWO_CELL_I M1007C1


3T_NRT_IN_ACT_SETHREE_CELL M1007C21T_RT_IN_ACT_SETHREE_CELL M1007C2

2NRTN_ACT_SET_TWO_CELL_I M1007C20RTN_ACT_SET_TWO_CELL_I M1007C1


RNC_79B OverheadHandover Soft



… … …Source_cell_Z 245 45


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Accessibility

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AccessibilityIf LOW accessibility RRC from:

• Accessibility Statistical Counters

• DRIVE TEST

Specific counter for Resource monitoring can be evaluated:

1. RRC_CONN_STP_FAIL_AC/RRC_CONN_STP_FAIL_all >> UL/DL Cell Load & code allocation

2. RRC_CONN_STP_FAIL_BTS/ RRC_CONN_STP_FAIL_all >> CE usage

3. RRC_CONN_STP_FAIL_TRANS/ RRC_CONN_STP_FAIL_all >> CAC rej or AAL2 setting up fail

4. RRC SETUP FAIL DUE TO IUB AAL2 TRANS / RRC_CONN_STP_FAIL_all >> AAL2 shortage

5. RRC CONN SETUP FAIL DUE TO RNTI ALLO FAIL / RRC_CONN_STP_FAIL_all >> RRMU overload

Could be useful for congestion detection to not neglect the analysis of failure in access phase with cause RADIO

RRC_CONN_ACC_FAIL_RADIO/RRC_SETUP_COMP (Sync) >> UL/DL Cell Load and coverage plot

Confidential


RRC Accessibility

Yes

RRC fail AC?

RRC fail BTS?

RRC fail from DT & Statistic

RRC fail Trans?

Yes

Yes

Yes

Radio Congestion

KPI(1)?

Yes

KPI(2)?

Interference et al.

HW problem et al.

CE Congestion

Yes

AAl2 Congestion

RRC fail AAL2?Iub Congestion Yes

RRC FAIL AC

If the condition triggered is RRC_CONN_STP_FAIL_AC the power analysis is required either Tx or Rx and code availability

If the thresholds are correctly settled but the cell seems to be congested according to the class3 and class4 permanence time a cross check on the effective traffic present is required.

Some interferer can be discovered by the drive test result.

Otherwise an expansion must be considered

RRC Fail BTS

RL rejection from BTS sending a NBAP: RL Setup Failure.

Old counters M1005 are replaced by the one created for 3GGP Iub

The most important cause for RNO included in is the lack of CE

WSP expansion or new site is required

Iub not Congested

Confidential


RRC Accessibility – AC Congestion

%100__

__

_

ClassesAllk

kDENOMPRXTOT

XDENOMPRXTOT %100__

__

_

ClassesAllk

kDENOMPRXTOT

XDENOMPRXTOT

%100__

__

_

ClassesAllk

kDENOMPTXTOT

XDENOMPTXTOT %100__

__

_

ClassesAllk

kDENOMPTXTOT

XDENOMPTXTOT

%100

___

____

___

256

4

256

4

x

x

SFxAVAILABLECODESNO

ALLOTREECODESUCCNBR

SFxAVAILABLECODESNO %100

___

____

___

256

4

256

4

x

x

SFxAVAILABLECODESNO

ALLOTREECODESUCCNBR

SFxAVAILABLECODESNO

%_CAPACITYDENOM_CODE

ITYCODE_CAPACRNC_113a 100

%

_CAPACITYDENOM_CODE

ITYCODE_CAPACRNC_113a 100

KPI (1)

Uplink Cell load

Downlink Cell load

Code blocking

Average Code Tree Occupancy

Confidential


RRC Accessibility – BTS Congestion

CEAVE_AVAIL_M5001C2

E_DLAVG_USED_CM5001C7 BTS in DL for CE utilised of Ratio AverageRNC_730A

CEAVE_AVAIL_M5001C2

E_DLAVG_USED_CM5001C7 BTS in DL for CE utilised of Ratio AverageRNC_730A

CEAVE_AVAIL_M5001C2

E_ULAVG_USED_CM5001C8 BTS in UL for CE utilised of Ratio AverageRNC_731A

CEAVE_AVAIL_M5001C2

E_ULAVG_USED_CM5001C8 BTS in UL for CE utilised of Ratio AverageRNC_731A

KPI (2)CE Usage

Confidential


RAB Accessibility

If Low accessibility RAB from:

• DUETTO

• DRIVE TEST

Considering that after RANAP: Rab Assignment Request from Core a double check is

requested.

Due to DCH0/0 allocation more significant are CS for AC and BTS fail cause and PS for TRANS

after reconfiguration

PS services that can suffer more the following cases can be evaluated:

CS

1. RAB SETUP FAILURES DUE TO AC

PS

1. RAB SETUP FAILURES DUE TO BTS

2. RAB SETUP FAILURES DUE TO TRANSPORT (AAL2)

3. RAB SETUP FAILURES DUE TO IUB AAL2 TRANS

Confidential


RAB Accessibility

L_IN_DRNCDATA_384_D)ALLO_FOR_(M1002C314 L_IN_DRNCDATA_320_D)ALLO_FOR_(M1002C313


_IN_DRNCDATA_64_DL)ALLO_FOR_(M1002C310 _IN_DRNCDATA_32_DL)ALLO_FOR_(M1002C307

_IN_DRNCDATA_16_DL)ALLO_FOR_(M1002C305 IN_DRNCDATA_8_DL_)ALLO_FOR_(M1002C303

L_IN_SRNCACKG_384_D)ALLO_PS_B(M1002C173 L_IN_SRNCACKG_320_D)ALLO_PS_B(M1002C172


_IN_SRNCACKG_64_DL)ALLO_PS_B(M1002C169 _IN_SRNCACKG_32_DL)ALLO_PS_B(M1002C168

_IN_SRNCACKG_16_DL)ALLO_PS_B(M1002C167 IN_SRNCACKG_8_DL_)ALLO_PS_B(M1002C166

DL_IN_SRNCNTERA_384_)ALLO_PS_I(M1002C157 DL_IN_SRNCNTERA_320_)ALLO_PS_I(M1002C156


L_IN_SRNCNTERA_64_D)ALLO_PS_I(M1002C153 L_IN_SRNCNTERA_32_D)ALLO_PS_I(M1002C152

L_IN_SRNCNTERA_16_D)ALLO_PS_I(M1002C151_IN_SRNCNTERA_8_DL)ALLO_PS_I(M1002C150

G_TRANSIL_PS_BACKRAB_STP_FA M1001C111R_TRANSIL_PS_INETRAB_STP_FA M1001C106 CAC todue rate Failure Reserv Iub PS



_IN_DRNCDATA_64_DL)ALLO_FOR_(M1002C310 _IN_DRNCDATA_32_DL)ALLO_FOR_(M1002C307

_IN_DRNCDATA_16_DL)ALLO_FOR_(M1002C305 IN_DRNCDATA_8_DL_)ALLO_FOR_(M1002C303



_IN_SRNCACKG_64_DL)ALLO_PS_B(M1002C169 _IN_SRNCACKG_32_DL)ALLO_PS_B(M1002C168

_IN_SRNCACKG_16_DL)ALLO_PS_B(M1002C167 IN_SRNCACKG_8_DL_)ALLO_PS_B(M1002C166



L_IN_SRNCNTERA_64_D)ALLO_PS_I(M1002C153 L_IN_SRNCNTERA_32_D)ALLO_PS_I(M1002C152

L_IN_SRNCNTERA_16_D)ALLO_PS_I(M1002C151_IN_SRNCNTERA_8_DL)ALLO_PS_I(M1002C150

G_TRANSIL_PS_BACKRAB_STP_FA M1001C111R_TRANSIL_PS_INETRAB_STP_FA M1001C106 CAC todue rate Failure Reserv Iub PS

When a RRC Fail TRANS is triggered a KPI for CAC rej & AAL2setup failure can beuseful to evaluate the failure rate

1© Nokia Siemens Networks RNO / Wind 17/10/2007 - NMI Confidential RNO Wind Part I.

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Transcript of 1© Nokia Siemens Networks RNO / Wind 17/10/2007 - NMI Confidential RNO Wind Part I.