Performance Management

11

Performance Management

April 4, 2008

Performance Management

April 4, 2008

22

DefinitionDefinition

Performance management is one of the management

functional areas of Telecommunication Management

Network (TMN). Performance management involves

monitoring, analyzing, and controlling the network

performance. Performance management is defined as

follows: Collecting performance data of the network,

equipment, functions, services, or other objects

periodically or in event-triggering mode; Collecting

performance-related flow data; Analyzing and handling

collected data; Saving and managing collected data.

33

ContentsContents

Performance Data

Real Time Performance Monitoring

RAN Key Performance Index (KPI)

Performance Analysis and Optimization

44

Performance Data StructurePerformance Data Structure

Level 1: performance statisticsLevel 2: history performance dataLevel 3: system monitoring data

55

Performance Data LevelsPerformance Data LevelsItem Sub-Item Main Use

RAN Key Performance Indicators

Key Performance Indicator (KPI)

KPI monitoring, KPI reporting, and northbound interface

Common performance indicator

Performance data reporting, northbound interface, general network performance, traffic, and equipment usage evaluation

History performance data Call history record (CHR) CDR analysis, QoS evaluation, common problem location, user complaint handling

System History Record (SHR)

Recording of network or cell status and analysis of CHRs

RAN Tracing and Monitoring Data

Real-Time User Monitor (RUM)

Further analysis of the problems that cannot be located according to CHRs, by analyzing specified IMSIs or random IMSIs that are admitted on the carriers with high call drop rates

Real-Time System Monitor (RSM)

Real-time recording of system status, such as load information and interference information, to help locate deep-seated problems

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ContentsContents

Performance Data




77

Real Time Performance MonitoringReal Time Performance MonitoringKPI Name Description

RRC Connection Setup Success Rate (service) Number of RRC connection setup successes (service) / Number of RRC connection setup attempts (service)

AMR RAB Assignment Success Rate Number of AMR RAB assignment successes / Number of AMR RAB assignment attempts

VP RAB Assignment Success Rate Number of VP RAB assignment successes / Number of VP RAB assignment attempts

PS RAB Assignment Success Rate Number of PS RAB assignment successes / Number of PS RAB assignment attempts

CS AMR Call Drop Rate Number of AMR call drops / Number of AMR RAB assignment successes

VP Call Drop Rate Number of VP call drops / Number of VP RAB assignment successes

PS Service Drop Rate Number of PS call drops / Number of AMR PS setup successes

Soft Handover Success Rate Number of soft handover successes / Number of soft handover attempts

CS Inter-RAT Handover Success Rate (from UTRAN to GSM) Number of successful CS service handovers from UMTS / Number of attempted CS service handovers from UMTS

PS Inter-RAT Handover Success Rate (from UTRAN to GSM) Number of successful PS service handovers from UMTS / Number of attempted PS service handovers from UMTS

UL CE Usage Rate Occupied NodeB UL CE resources / Total NodeB UL CE resources

DL CE Usage Rate Occupied NodeB DL CE resources / Total NodeB DL CE resources

UL Iub Allocated Bandwidth Usage Rate Allocated bandwidth of UL Iub / Physical bandwidth of UL Iub

DL Iub Allocated Bandwidth Usage Rate Allocated bandwidth of DL Iub / Physical bandwidth of DL Iub

DL Code Usage Rate Occupied DL code resources / Total cell code resourcesPS UL Throughput -PS DL Throughput -

88

ThresholdsThresholdsKPI Name Threshold

RRC Connection Setup Success Rate (service) >98%AMR RAB Assignment Success Rate >98%VP RAB Assignment Success Rate >98%PS RAB Assignment Success Rate >98%CS AMR Call Drop Rate <2%VP Call Drop Rate <3%PS Service Drop Rate <5%Soft Handover Success Rate >98%CS Inter-RAT Handover Success Rate (from UTRAN to GSM) >95%PS Inter-RAT Handover Success Rate (from UTRAN to GSM) >89%UL CE Usage Rate DL CE Usage Rate UL Iub Allocated Bandwidth Usage Rate DL Iub Allocated Bandwidth Usage Rate DL Code Usage Rate PS UL Throughput PS DL Throughput

99

Real Time Performance MonitoringReal Time Performance Monitoring

1010


1111


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1515


1616


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1919


2020


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ContentsContents

Performance Data




2222

DefinitionDefinition

• Key performance indicators (KPIs) are a set of selected indicators used for measuring the current network performance and trends. KPIs highlight the key factors of network monitoring and warn in time of potential problems. KPIs are also used to prioritise the corrective actions.

2323

ContentsContents

RRC Connection Success Rate

RAB Establishment Success Rate

Call Setup Success Rate

Call Drop Rate

Soft Handover Success Rate

Inter-RAT Hard Handover Success

Rate

Congestion Rate

Traffic Load

2424

Radio Resource Control (RRC)Radio Resource Control (RRC)

• Radio resource control (RRC) state is also called packet data transfer state.

• The description of the packet data transfer states given here is based on the 3GPP RRC protocol specification. The Figure RRC states and state transitions shows the supported RRC states and state transitions.

• The RRC handles the control plane signalling of layer 3 between the Ues and RAN. RRC allows a dialogue between the RAN and the UE and also between the core network and the UE. An RRC connection is a logical connection between the UE and the RAN used by two peer entities to support the upper layer exchange of information flows. There can only be one RRC connection per UE. Several upper layer entities use the same RRC connection.

2525

RRC StatesRRC States

CELL_DCH CELL_FACH

CELL_PCHURA_PCH

IDLE

DEAD - Scanning networks (PLMN)- ”Camp on” cell

- Monitor paging channel- cell re-selection

- Dedicated Channel- Radio bearers Transmission Services - upper layer Signaling

trigger (CN)

- Reduce action ， DTX ， and save power

RRC connection

2626

RRC Key FunctionsRRC Key Functions

Establishing, re-establishing, maintaining and releasing the RRC connection (i.e. the first signaling connection for the UE) between the UTRAN and the UE

Establishing, re-configuring and releasing the radio access bearers in the user plane of layer 2 and layer 1

Evaluation, decision-making and execution relating to RRC connection mobility (e.g. handover, cell/paging area update procedures and so on) during an established RRC connection

Controlling the measurements performed by the UE (e.g. measurement item, measurement timing, the way of reporting, and so on)

2727

General FormulaGeneral Formula

The formula of RRC Setup Success Rate:

RRC Setup Success Rate = (RRC Connection

Setup Success / RRC Connection Request) ×

100%

2828

Actual FormulaActual Formula

The formula of RRC Setup Success Rate:

RRC Setup Success Rate = {([RRC.SuccConnEstab.OgConvCall]+[RRC.SuccConnEstab.OrgStrCall]

+[RRC.SuccConnEstab.OrgItrCall]+[RRC.SuccConnEstab.OrgBkgCall]+

[RRC.SuccConnEstab.OrgSubCall]+[RRC.SuccConnEstab.TmConvCall]+

[RRC.SuccConnEstab.TmStrCall]+[RRC.SuccConnEstab.TmItrCall]+

[RRC.SuccConnEstab.TmBkgCall]+[RRC.SuccConnEstab.EmgCall]+

[RRC.SuccConnEstab.OgHhPrSig]+[RRC.SuccConnEstab.OgLwPrSig]+

[RRC.SuccConnEstab.CallReEst]+[RRC.SuccConnEstab.TmHhPrSig]+

[RRC.SuccConnEstab.TmLwPrSig]+[RRC.SuccConnEstab.Unkown])/

([RRC.AttConnEstab.OrgConvCall]+[RRC.AttConnEstab.OrgStrCall]+

[RRC.AttConnEstab.OrgInterCall]+[RRC.AttConnEstab.OrgBkgCall]+[RRC.AttConnEstab.OgSubCall]

+[RRC.AttConnEstab.TmConvCall]+[RRC.AttConnEstab.TmStrCall]+[RRC.AttConnEstab.TmInterCall]

+[RRC.AttConnEstab.TmBkgCall]+[RRC.AttConnEstab.EmgCall]+[RRC.AttConnEstab.OgHhPrSig]+

[RRC.AttConnEstab.OgLwPrSig]+[RRC.AttConnEstab.CallReEst]+[RRC.AttConnEstab.TmHhPrSig]+

[RRC.AttConnEstab.TmLwPrSig]+[RRC.AttConnEstab.Unknown])}*100%

2929

Call FlowCall Flow

Setting RRC Connection

3030

Call FlowCall Flow

RRC Connection Setup Failure and Retry

3131

Call FlowCall Flow

RRC Connection Release

3232

RRC Connection Setup Failure CausesRRC Connection Setup Failure Causes

KPI Failure Cause

VS.RRC.Rej.RL.Fail RL setup failure

VS.RRC.Rej.AAL2.Fail AAL2 setup failure

VS.RRC.Rej.Power.Cong Congestion due to power resources

VS.RRC.Rej.UL.CE.Cong Congestion due to UL CE resources

VS.RRC.Rej.DL.CE.Cong Congestion due to DL CE resources

VS.RRC.Rej.Code.Cong Congestion due to code resources

VS.RRC.Rej.Other.Cong Congestion due to other causes

RRC.FailConnEstab.NoReply No response is received from the UE.

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ContentsContents




Call Drop Rate



Rate

Congestion Rate

Traffic Load

3434

Radio Access Bearer (RAB)Radio Access Bearer (RAB)

• When a connection is requested, bearers are allocated by a bearer translation function.

• This function correlates the requested attributes with the list of supported bearers and makes an appropriate choice.

• Provide information between a UE and the core network on the quality requirements that must be satisfied for a service. This Quality of Service (QoS) is expressed by parameters such as data rate, block size, and error rate. The QoS required differs depending on the service.

3535

Supported BearersSupported BearersQoS Class Bit Rate (bps)

CONVERSATIONAL

80001220016000238502880032000320005600064000

STREAMING

800016000320005760064000

128000144000256000384000

3636

Supported BearersSupported BearersQoS Class Bit Rate (bps) QoS Class Bit Rate (bps)

BACKGROUND

0

INTERACTIVE

08000 8000

16000 1600032000 3200064000 64000

128000 128000144000 144000256000 256000384000 384000608000 608000768000 768000

1024000 10240001450000 14500001536000 15360001800000 18000002048000 20480002890000 28900003648000 36480005760000 57600007200000 7200000

10100000 1010000014400000 14400000

3737


The formula of RAB Establishment Success

Rate:

RAB Setup Success Rate = RAB

Assignment Success / RAB Assignment

Request × 100%

3838


The formula of RAB Establishment Success

Rate:

RAB Setup Success Rate =

([VS.RAB.SuccEstab.AMR]/[VS.RAB.At

tEstab.AMR])*100%

3939

Call FlowCall Flow

RAB Establishment Procedure

4040

RAB Establishment Failure CausesRAB Establishment Failure Causes

KPI Failure Cause

VS.RAB.FailEstabCS.TNL Transport network problem

VS.RAB.FailEstCS.Relo Relocation

VS.RAB.FailEstCs.Power.Cong Congestion due to power resources

VS.RAB.FailEstCs.ULCE.Cong Congestion due to UL CE resources

VS.RAB.FailEstCs.DLCE.Cong Congestion due to DL CE resources

VS.RAB.FailEstCs.Code.Cong Congestion due to code resources

VS.RAB.FailEstCs.IUB.Band Congestion due to transmission resources

VS.RAB.FailEstabCS.Other.Cell Other causes

VS.RAB.FailEstabCS.Unsp.Other Configuration not supported

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ContentsContents




Call Drop Rate



Rate

Congestion Rate

Traffic Load

4242

Call Setup Success Rate (CSSR)Call Setup Success Rate (CSSR)

• In reference to 3GPP TS 25.931, a call setup will be described by the concatenation of the phases

• 1. RRC Connection Establishment• 2. RAB Establishment

4343


The formula of Call Setup Success Rate :

Call Setup Success Rate =

RRCSetupSuccRate × RABSetupSuccRate

×100%

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ContentsContents




Call Drop Rate



Rate

Congestion Rate

Traffic Load

4545

Call Drop Rate (CDR)Call Drop Rate (CDR)

A call is released by the CN with either RANAP:RAB

ASSIGNMENT REQUEST or RANAP: IU RELEASE

COMMAND (defined in 3GPP specifications about UTRAN

Iu interface RANAP signalling). The release can be a normal

release or a drop.

Call Drop Rate of Signaling Plane is calculated by counting

RNC-originated Iu connection release.

Can be divided into two parts: CS&PS

4646


The formula of Call Drop Rate of CS:

Call Drop Rate of CS Plane = RNC-originated CS Domain

Iu Connection Release / RNC-originated CS Domain Iu

Connection Setup Success× 100%

The formula of Call Drop Rate of PS:

Call Drop Rate of PS Plane = RNC-originated PS Domain

Iu Connection Release / RNC-originated PS Domain Iu

Connection Setup Success× 100%

4747


The formula of Call Drop Rate of CS:

Call Drop Rate of CS Plane =

{[VS.RAB.Loss.CS.AMR]/([VS.RAB.Loss.CS.AMR]+

[VS.RAB.Loss.CS.Norm.AMR]) }*100%

The formula of Call Drop Rate of PS:

Call Drop Rate of PS Plane = {([VS.RAB.Loss.PS.RF]+

[VS.RAB.Loss.PS.Abnorm])/([VS.RAB.Loss.PS.RF]+

[VS.RAB.Loss.PS.Abnorm]+[VS.RAB.Loss.PS.Norm]) }*

100%

4848

Call FlowCall Flow

SRNC CN

RANAP RANAP

RANAP RANAP

RANAP RANAP

Iu Release Request

Iu Release Command

Iu Release Complete

4949

Call Drop CausesCall Drop Causes

KPI Failure Cause

VS.RAB.RelReqCS.OM OM interference

VS.RAB.RelReqCS.RABPreempt RAB preemption

VS.RAB.RelReqCS.UTRANgen UTRAN-generated cause

VS.RAB.Loss.CS.RF.RLCRst RLC reset

VS.RAB.Loss.CS.RF.ULSync UL synchronization failure

VS.RAB.Loss.CS.RF.UuNoReply No response from Uu

VS.RAB.Loss.CS.RF.Oth Other RF causes

VS.RAB.Loss.CS.Aal2Loss AAL2 link abnormal

VS.Call.Drop.CS.Other Other causes

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ContentsContents




Call Drop Rate



Rate

Congestion Rate

Traffic Load

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Soft HandoverSoft Handover

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Soft Handover AdvantagesSoft Handover Advantages

a seamless handover without a disconnection of the RAB

fast closed-loop power control optimisation (the UE is always linked

with the strongest cell)

a sufficient reception level for maintaining communications by

combining reception signals (macrodiversity) from multiple cells when

the UE moves to cell boundary areas and cannot obtain a sufficient

reception from a single cell

5353

Soft HandoverSoft Handover

Soft handover means that the UE is connected to more than one

WCDMA BTS at the same time (this is why it is also called a "macro

diversity handover"). When in connected mode, the UE continuously

measures serving and neighbouring WCDMA BTSs (cells indicated by

the RNC) on the current carrier frequency. The UE compares the

measurement results with handover thresholds, which have been

provided by the Radio Network Controller (RNC). When a

measurement yields a value that exceeds a given threshold, the UE

sends a measurement report to the RNC.

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The formula of Soft (Softer) Handover

Success Rate:

Soft (Softer) Handover Success Rate = Soft

(Softer) Handover Success / Soft (Softer)

Handover Request× 100%

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The formula of Soft (Softer) Handover

Success Rate:

Soft (Softer) Handover Success Rate =

([VS.SHO.AMR.SuccOut]/[VS.SHO.AMR.AttOut])

* 100%

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Call Flow (Branch Addition)Call Flow (Branch Addition)

5757

Call Flow (Branch Deletion)Call Flow (Branch Deletion)

5858

Call Flow (Branch Replacement)Call Flow (Branch Replacement)

5959

SHO Failure CausesSHO Failure Causes

KPI Failure Cause

SHO.FailRLAddUESide.CfgUnsup Configuration not supported

SHO.FailRLAddUESide.Isr Synchronous reconfiguration not supported

SHO.FailRLAddUESide.InvCfg Configuration illegalSHO.FailRLAddUESide.NoReply No response from UE

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ContentsContents




Call Drop Rate



Rate

Congestion Rate

Traffic Load

6161

Inter RAT Hard Handover Success RateInter RAT Hard Handover Success Rate

• Handover mechanisms from UMTS to GSM are necessary if a UE leaves a UMTS coverage area while it has an active connection. Handover from UMTS to GSM is triggered when the quality of the UMTS link is below a certain threshold and the quality of the GSM link is above a certain threshold.

6262

Compressed ModeCompressed Mode

• Compressed mode is a radio path feature that enables the user equipment (UE) to maintain the current connection on a certain frequency while performing measurements on another frequency. This allows the UE to monitor neighbouring cells on another frequency (FDD) or radio access technology (RAT), typically GSM. Compressed mode means that transmission and reception are halted for a short time - a few milliseconds - in order to perform a measurement on another frequency or RAT. The required reception/transmission gap is produced without any loss of DCH user data by compressing the data transmission in the time domain.

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Compressed ModeCompressed Mode

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Call FlowCall Flow

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The formula of InterRAT Handover to GSM

Success Rate:

InterRAT Handover to GSM Success Rate =

inter-RAT handover from UTRAN to GSM

success / inter-RAT handover from UTRAN to

GSM attempts × 100%

6666


The formula of InterRAT Handover to GSM

Success Rate:

InterRAT Handover to GSM Success Rate =

([IRATHO.SuccOutCS]/[IRATHO.AttOutCS])*100%

6767

Call FlowCall Flow

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Inter RAT Handover CausesInter RAT Handover Causes

KPI Failure Cause

IRATHO.FailOutCS.CfgUnsupp Configuration not supported

IRATHO.FailOutCS.PhyChFail Physical channel failure

VS.IRATHO.FailOutCS.Other Other causes

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ContentsContents




Call Drop Rate



Rate

Congestion Rate

Traffic Load

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Signaling Congestion RateSignaling Congestion Rate

The formula of Signaling Congestion Rate:

Signaling Congestion Rate = RRC Connection Reject (Cause:

congestion) / RRC Connection Request × 100%

UE RNCNodeB

RRC RRCRRC Connection Request

RRC RRC Connection Reject (Cause : Congestion) RRC

7171

Traffic Congestion RateTraffic Congestion Rate

Traffic Congestion Rate is calculated by counting

the RAB Assignment Setup Failure (cause:

congestion).

Can be divided into two parts: CS&PS

7272


The formula of CS Traffic Congestion Rate:

CS Traffic Congestion Rate = CS Domain RAB Assignment Setup

Failure (Congestion) / CS Domain RAB Assignment Setup Request

× 100%

The formula of PS Traffic Congestion Rate:

PS Traffic Congestion Rate = PS Domain RAB Assignment Setup

Failure (Congestion) / PS Domain RAB Assignment Setup Request

× 100%

7373


SRNC CN

RANAP RANAPRAB Assignment Request

RANAP RANAPRAB Assignment Response (Failure cause: Congestion)

7474

ContentsContents




Call Drop Rate



Rate

Congestion Rate

Traffic Load

7575

CS TrafficCS Traffic

One Erlang is defined as the one 12.2K CS AMR call lasting

for one hour. The traffic of other different services are

derived by converting to equivalent 12.2K CS AMR call.

CS Traffic for two types of QoS:

CS Conversational Traffic (i.e. voice and video)

CS Streaming Traffic (e.g. streaming video or audio)

CS Traffic for two types of Service:

CS AMR Traffic (Voice)

CS CONV 64k Traffic (Video Phone)

7676

PS TrafficPS Traffic

The traffic of different services are derived by

converting to equivalent 12.2K CS AMR call.

PS Traffic for four types of QoS:

PS Conversational Traffic

PS Streaming Traffic

PS Interactive

Background Traffic

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PS ThroughputPS Throughput

PS Throughput for four types of QoS (in Bytes)

PS UL Conversational services Throughput

PS UL Streaming services Throughput

PS UL Interactive services Throughput

PS UL Background services Throughput

PS DL Conversational services Throughput

PS DL Streaming services Throughput

PS DL Interactive services Throughput

PS DL Background services Throughput

7878

Things to ConsiderThings to Consider

Channel Elements

Transmit power of cell

RTWP

Code Utilization

Cell Throughput

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ContentsContents

Performance Data




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Alarm AnalysisAlarm Analysis• Power system alarm - A power system alarm is raised by the power supply.• Environment system alarm - An environment system alarm is an alarm about the environment of the equipment room, such as temperature, humidity, or gate.• Signaling system alarm - A signaling system alarm is an alarm about the signaling system, such as No. 7 signaling or No. 1 signaling.• Trunk system alarm - A trunk system alarm is an alarm about the trunk system, such as E1, STM-1 optical or electrical relay.• Hardware system alarm - A hardware system alarm is an alarm about a board device, such as clock or CPU.• Software alarm - A software system alarm is an alarm about software.• Running system alarm - An running system alarm is an alarm about the M2000 running.• Communication system alarm - A communication system alarm is an alarm about the communication system.• QoS alarm - A QoS alarm is an alarm about QoS.• Processing error alarm - Processing error alarms are alarms about other exceptions that are not described here.

8181

Level 1 Analysis ProcessLevel 1 Analysis Process

8282

Network KPI AnalysisNetwork KPI Analysis

Step 1 of performance analysis and quality early warning is to make an overall analysis

of network KPIs. The KPIs include, but are not limited to traffic, call completion rate,

handover success rate, and call drop rate. For those which contain specific services, such

as HSDPA and CMB, or specific algorithms, we also need to observe the integral indexes

of corresponding KPIs.

Analyze the KPI of daily report or weekly report as required.

The judgment of whether the KPI is abnormal must be based on the comparison with

early history. We may observe the extent of relative change instead of the absolute value

of the KPI.

When there is no apparent change in the KPI, there are two processing modes: End the

current performance analysis and analyze TOPN cell. When there are a large number of

network cells, the performance deterioration of very few base stations may not apparently

affect the overall network KPI. These abnormal cells can be found out by contrasting

TOPN analysis.

When the relative value of the KPI is not apparently changed but its absolute value

always cannot reach standards and no analysis conclusion has been drawn, we need to

analyze specific causes according to traffic statistics data and conduct quality early

warning.

8383

RNC Equipment Problem/Interface/Parameter etc.RNC Equipment Problem/Interface/Parameter etc.

RNC equipment problem and IUR interface transmission problem

may affect the whole-network KPI.

IU interface transmission problem and core network problem will

affect the whole-network KPI directly.

If the performance indexes of network cells are universally

deteriorated, basic causes are related to the RNC board reset and

restricted IU interface transmission. Transmission bandwidth restricted

can be checked by observing transmission-related PIs from traffic

statistics.

Another case of affecting the overall KPI of RNC: RNC-level

parameter change. If the whole-network KPI becomes apparently

abnormal, we need to make sure whether any RNC-level parameter

change has been made recently and carefully check the impact of this

parameter on the network.

8484

KPI Analysis of TOPN CellsKPI Analysis of TOPN Cells

The number of TOPN cells can be increased according to the network scale. If

there are too few TOPN cells, some cells with abnormal performance may be

ignored.

The WCDMA Performance Monitoring Report output by the Nastar tool lists

the TOPN with normal KPIs. According to this report, we may pick out important

cells from TOPN cells and make an in-depth analysis.

A comparison of the indexes of TOPN cells with those of history TOPN cells

helps judge whether cell performance indexes are normal. It is recommended to

use the above-mentioned trend analysis figure for comparison. Make sure

whether TOPN cell Id changes and what the amplitude of change in TOPN cell

KPI is. This is simple but visual.

TOPN cell problems must be analyzed together with cell traffic. For example,

a pure observation of the call drop rate of a cell is meaningless. If a cell has one

call drop, but there is only one call attempt, the call drop rate is 100%.

8585

Cell Equipment AnalysisCell Equipment Analysis

Cell equipment analysis means analyzing the equipment of

TOPN cells of last step. Likewise, subsequent load problem

analysis and interference problem analysis are oriented to

TOPN cells.

The equipment that affects cell performance KPI includes the

antenna feeder equipment and the uplink/downlink processing

board of a base station. Generally, related equipment alarms

can be observed either on the NodeB side or on the RNC side.

The transmission restricted and intermittent transmission

failure of a base station will affect related cell indexes.

8686

Cell Load AnalysisCell Load Analysis

The indexes directly related to cell load include average uplink/downlink

occupied CE of a cell (VS.LC.ULCreditUsed.CELL/2,

VS.LC.DLCreditUsed.CELL) and the maximum uplink/downlink occupied CE

(VS.LC.ULCreditUsed.CELL.Max/2, VS.LC.DLCreditUsed.CELL.Max). When

the maximum uplink/downlink occupied CE approaches 128 or the average

occupied CE is around 60, expansion should be considered.

Causes for cell load problems include: change of traffic model; the main

coverage service of this cell is designed to be VP64, but actually there are a

large number of 384k services. During holidays, relatively concentrated

population leads to the increase in traffic.

High load may cause CE congestion, power congestion, code congestion, and

transmission congestion. We should make an analysis by observing

corresponding PI.

In load problem analysis, when much power congestion occurs, actual load is

not necessarily very high. In this case, we need to analyze admission strategy

and judge whether admission parameters are properly set.

8787

Cell Interference AnalysisCell Interference Analysis

Causes of interference: UE self-correlation interference. If there are

many UEs in a conversation within a cell, interference will increase.

Interference is also caused by external interference source and by pilot

pollution.

Whether there is any uplink interference within a cell can be judged

by observing the RTWP indexes in traffic statistics, that is, the average

RTWP of a cell and the maximum RTWP of a cell. If the average

RTWP of a cell is as high as -95 dBm or higher, it is possible that there

is uplink interference. Observe the maximum RTWP. If RTWP peak,

such as -70 dBm, is often seen, the cause may be the power of access

process or handover process.

8888

Cell Coverage AnalysisCell Coverage Analysis

Coverage problems include poor coverage, excessive coverage, pilot

pollution, and missing configuration of adjacent cells.

Poor coverage leads to poor performance of an air interface. In traffic

statistics, a large number of PIs, such as RF.RLCRst, RF.ULSync and

UuNoReply, are related to poor coverage.

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9191

Call Data TracingCall Data Tracing

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Performance Management