coaching session_3g voice call analysis_v04

8/3/2019 Coaching Session_3G Voice Call Analysis_v04

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1 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials

Company Confidential

3G Voice Call Analysis

Analysis of drive test log files


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Objective

To understand the progress of a 3G voice call from the perspective of drive testing.

To understand what a good call look like

To understand typical failures seen in the drive test logs

If times permit to look at individual issues raised by the audience. Improve ability to analyse drive test log and understand the failures

NOT discussing Counters, Logging equipment, analysing tools, RNC logging.

NOT discussing Counters, Logging equipment, analysing tools, RNC logging.


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Agenda

Overview of used protocols

Short introduction to Radio protocol, Iub, Iu-CS

Overview of Radio Resource Management

Signalling in a normal successful call

MTC and MOC Call setup

Active set update

Intersystem handover Disconnect

Methods used for analysing drive test log files

Examples of unsuccessful calls Additional examples of signalling in case of failures


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Protocol Stacks

Node B RNC Multimedia

Gateway 3G MSCUu Iub

Iu,cs A

CS Core Network

Communication between UE, RNC and CS Core makes use of Uu, Iub, Iu.cs and A Interfaceprotocols

All protocols includes both user and control planes

The control plane of one protocol stack may make use of the user plane of anotherprotocol stack e.g. RRC messages which form the control plane of the radio accessprotocol are communicated to and from the Node B using the user plane of the Iubprotocol stack


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Protocol Summary

In drive test analysis two types of message are visible from the drive test log

RRC messages

NAS messages note that NAS message is embedded in RRC messages

RNC

Node B

UECore

SWPRB

NAS Messages

RRC Messages

NBAPMessages RANAP

Messages

SWPRB

InternalMessages

ALCAPMessages


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CS Radio Interface Protocol (RIP) User Plane

The 3G MSC provides connectivity to the circuit switched core and PSTN

The multimedia gateway provides transcoding for

Speech calls: between AMR and A Law PCM

Video calls: no transcoding is required i.e. vocoder appears only in the UE Transparent mode RLC is used between the UE and RNC

AAL2 based ATM is used to transfer user plane data across the Iub and Iu,cs interfaces

WCDMA

L1

e.g.

vocoder

WCDMA

L1

AAL2

FP

ATM

Phy

MAC

RLC-U

AAL2

FP

ATM

Phy

MAC

RLC-U

AAL2

ATM

Phy

Iu,cs

UP

AAL2

ATM

Phy

Iu,cs

UP

e.g.

vocoder

Phy Phy Phy

Link

Layer

Link

Layer

A Law

PCM,

etc

A Law

PCM,

etcPSTN

UE

Node B

RNCMultimedia GW 3G MSC

Uu Iub Iu,cs A


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CS Radio Interface Protocol (RIP) Control Plane

The radio interface protocol control plane allows RRC signalling between the RNC and UE

RRC signalling is communicated across the Iub using the Iub user plane protocol stack

i.e. using Frame protocol and AAL2 based ATM

Acknowledged or unacknowledged mode RLC is used between the UE and RNC

WCDMA

L1

RRC

WCDMA

L1

AAL2

FP

ATM

Phy

MAC

RLC-C

AAL2

FP

ATM

Phy

MAC

RLC-C

UE

Node B

RNC

Uu Iub

RRC


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Iub Protocol Stack

The Iub protocol stack has threeplanes

The radio network control plane uses

the NBAP protocol and completes

tasks such as configuring a radio linkat a Node B

The transport network control plane

uses ALCAP and is responsible for

setting up and tearing down userplane transport bearers

The user plane uses Frame Protocol

and is responsible for encapsulating

all data to and from the UE

User Plane

Physical Layer

AAL2

ATM

AAL5 AAL5

SSCOP

SSCF-UNI

Q.2150.2

SSCOP

SSCF-UNI

ALCAP Q.2630.1

NBAP Frame Protocol

Radio Network

Control Plane

Transport Network

Control Plane


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Iu-cs Protocol Stack

The Iu-cs protocol stack has threeplanes

The radio network control planeuses the RANAP protocol and

completes tasks such asconfiguring a RAB or assigning Iu-cs resources

The transport network controlplane is responsible for setting up

and tearing down Iu transportbearers

The user plane is responsible forencapsulating all data to and from

the UE

User Plane

Physical Layer

AAL2

ATM

AAL5 AAL5

SSCOP

SSCF-NNI

MTP3b

SSCOP

SSCF-NNI

Q.2150.1

RANAP Iu User PlaneProtocol

Radio Network

Control Plane

Transport Network

Control Plane

MTP3b

SCCP

Q.2630.1


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Radio Resource Management (RRM): Tasks

Predict the impact on interference (power) ofadmitting a new user for Uplink and Downlink

Perform appropriate actions (e.g. new call

admissions, bitrate increase/decrease etc.) inaccordance with load conditions

Provide different quality of service for real time

(RT) and non-real time (NRT) users

Take appropriate corrective action when the

different cell load thresholds are exceeded in

order to maintain cell stability (i.e. load control)

Overload

Load Target

Overload Margin

Power

Time

Estimated capacity forNRT trafficMeasured load caused

by non-controllable load(RT)

RT services must have higher quality assurance than NRT


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RRM is made up of a number of closely interdependent functions (i.e.algorithms)

These functions can be divided into:

Power Control (PC) Handover Control (HC)

Packet Scheduler (PS)

Load Control (LC)

Admission Control (AC)

Resource Management (RM)

RRM

Radio Resource Management (RRM): Functions

PC HC

PS

LC

RM

AC

ConnectionBased

Cell Based


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Radio Resource Management (RRM): Conn. based functions

Power Control (PC) Continuously monitors the quality of the radio link and adjusts MS, BTS powers

Ensures absolute minimum Tx power is used to maintain required quality

Subdivided into:

Closed loop PC,

Open loop PC and

Outer loop PC

Handover Control (HC) Manages the mobility of the users

Ensures MS is connected to the optimal cell(s) > minimisinginterference

Subdivided into: Intra-frequency handovers,

Inter-frequency (hard) handovers and

Inter-system handovers

RRM

PC HC

PS

LC

RM

AC


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Radio Resource Management (RRM): Cell based functions

Packet Scheduler (PS) Scheduling packets on the radio interface (UL/DL)

Ensures fast allocation of resources for NRT users

Load Control (LC) Takes care of radio network stability

Gathers interference information and provides cell load status to AC & PS

Admission Control (AC)

Performs the admission control for new bearers.

Predicts interference caused by the bearer and checkswhether there is room for it.

Power allocation

Defines transport channel parameters

Resource Management (RM)

Manages the physical resources of RAN

Maintains the code tree and code allocations

RRM

PC HC

PS

LC

RM

AC


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Signalling for a Successful AMR Call

Call setup

Mobile terminated call

Mobile originated call

Active call Measurement controls

Measurement reports

Active set updates Physical reconfigurations

Inter system handovers

Disconnect

Released by network (in drive test normally for MTC)

Released by user (in drive test normally for MOC)

NOTE: ASU is possibleafter RRC connection

is established but

not during Radio

bearer setup (seen

from the RNC side)

Mobile Terminated


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CoreNetwork

RANAPPAGINGRANAP

RRC RRCPAGING TYPE 1 (PCCH)

RRCRRCRRC CONNECTION REQUEST (CCCH)

Admission Control

RADIO LINK SETUP REQUEST NBAPNBAP

RADIO LINK SETUP RESPONSE NBAPNBAP

ALCAP ALCAPERQ

ECFALCAP ALCAP

RRC CONNECTION SETUP (FACH)RRCRRC

L1 SYNCHRONISATION

SYNCH INDICATION NBAPNBAP

RRCRRCRRC CONNECTION SETUP COMPLETE (DCH)

INITIAL DIRECT TRANSFER (Paging Response)RRC RRC

Mobile Terminated

Call (MTC) - I

Uplink SyncFP FP

FP FPDownlink Sync


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Mobile Terminated


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CoreNetwork

ERQ

ALCAP ALCAPECFALCAP ALCAP

RL RECONFIGURATION COMMIT NBAPNBAP

RRC RRCRADIO BEARER SET-UP (DCCH)

RRCRRC

RADIO BEARER SET-UP COMPLETE (DCCH)

RANAP RANAPRAB ASSIGNMENT RESPONSE

Mobile Terminated

Call (MTC) - III

MTC Call Established

Uplink SyncFP FP

FP FPDownlink Sync

ERQALCAP ALCAP

ECFALCAP ALCAP

DIRECT TRANSFER: CONNECT ACKNOWLEDGE

RRCRANAP RANAPRRC

DIRECT TRANSFER: ALERTINGRRCRANAP RANAPRRC

DIRECT TRANSFER: CONNECTRRCRANAP RANAPRRC

Mobile Originated


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CoreNetwork

RRCRRC RRC CONNECTION REQUEST (CCCH)

Admission Control



ALCAP ALCAPERQ

ECFALCAP ALCAP

RRC CONNECTION SETUP (FACH) RRCRRC

L1 SYNCHRONISATION


RRCRRCRRC CONNECTION SETUP COMPLETE

INITIAL DIRECT TRANSFER (MM CM Service Request)RRC RRC

Mobile Originated

Call (MOC) - I

Uplink SyncFP FP

FP FPDownlink Sync

SCCP: CONNECTION REQUEST

RANAP RANAP

INITIAL UE MESSAGE

SCCP SCCP

CMobile Originated


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CoreNetwork

Mobile Originated

Call (MOC) - II

RANAPRAB ASSIGNMENT REQUESTRANAP

Admission Control

RL RECONFIGURATION PREPARE NBAPNBAP

RL RECONFIGURATION READY NBAPNBAP

RANAPLOCATION REPORTING CONTROLRANAP

RANAPCOMMON IDRANAP

SCCP: CONNECTION CONFIRMSCCP SCCP

SECURITY MODE COMMAND COMPLETERRCRANAP RANAPRRC

SECURITY MODE COMMANDRRCRANAP RANAPRRC

DIRECT TRANSFER: CC SETUPRRCRANAP RANAPRRC

DIRECT TRANSFER : CC CALL PROCEEDINGRRCRANAP RANAPRRC

DIRECT TRANSFER (MM Authentication Response)RRCRANAP RANAPRRC

DIRECT TRANSFER (MM Authentication Request)RRCRANAP RANAPRRC

DIRECT TRANSFER (MM Identity Response)RRCRANAP RANAPRRC

DIRECT TRANSFER (MM Identify Request) RRCRANAP RANAPRRC

C

Mobile Originated


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CoreNetwork

ALCAP ALCAPERQ

ECFALCAP ALCAP

RL RECONFIGURATION COMMIT NBAPNBAP


RRCRRCRADIO BEARER SET-UP COMPLETE (DCCH)


Mobile Originated

Call (MOC) - III

MOC Call Established

ALCAP ALCAPERQ

ECFALCAP ALCAP

Uplink SyncFP FP

FP FPDownlink Sync

DIRECT TRANSFER: CONNECT ACKNOWLEDGERRCRANAP RANAPRRC

DIRECT TRANSFER: ALERTINGRRCRANAP RANAPRRC

DIRECT TRANSFER: CONNECTRRCRANAP RANAPRRC


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Layer 1 Synchronisation Once the Node B has relayed the RRC Connection Setup message it starts to

transmit the downlink DPCCH. Downlink power has been computed by theadmission control

Layer 3 of the UE uses timer T312 (6 s) and counter threshold N312 (4) todetermine whether or not the L1 synchronisation has succeeded. Both T312

and N312 were broadcast to the UE in SIB 1 On the BTS side after receiving N_INSYNC_IND synchronisation indicators the

BTS sends NBAP: SYNCHRONIZATION INDICATION message to RNC after whichthe closed loop and outer loop PC start to control the powers

RNC receives RRCConnection SetupComplete message

RRC Connection SetupComplete message SENT

L1 Synchronizationestablished

BTS sends NBAP:

SYNCHRONIZATION

INDICATION -messageTimer T312 started

UE receives in syncindicators on L1

N312 L1 in syncindicators

UE receives RRC ConnectionSetup message

On L1: Node B receives

N_INSYNC_IND indicators

L1Synchronization

established

Timer T312stopped


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Admission Control Summary

RB information

Resourceinformation

Active setinformation

Load changeinformation

Target BLER,B ER and SIR

Loadinformation

Admission Control

RAB admission decisionLoad change estimationProducing L2 parameters

Producing TFS

DL power allocation

Iu

Packet Scheduler

Radio resourcescheduling

Load Control

Producing of loadinformation

Power Control

UL Outer looppower control

Handover Control

Active state mobility

control

Resource Manager

Radio resource informationCode allocation

Transport resource allocation

Resourcerequest

RAB setup/modify/release request

Load

information


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UL Admission Overview

BTS sends periodically the received UL power to the RNC

Fractional load[0..1]

OVERLOAD

AREAMARGINAL

LOADAREA

FEASIBLELOADAREA

0

Load curve in UL

PrxTotal[dBm]

PrxNoise [dBm]

PrxTarget [dB]

PrxTarget [dB]+

PrxOffset [dB]

1

Noise RiseNR [dB]

XX [dB]

RNC compares the measured received power levels against the setthresholds

If measured UL (PrxTotal) load exceeds target thresholds (PrxTarget) ACcan admit NRT RABs to the cell. The NRT RAB bitrate can not beincreased and remains at the same level as after previous schedulingperiod

If measured UL (PrxTotal) load exceeds overload thresholds(PrxTarget+PrxOffset) no RABs can be admitted and NRT bitrates arereduced until PrxTotal reaches again PrxTarget

OverLoad

MarginalLoad

FeasibleLoad

In feasible load area the admission decision is based on the power riseestimate of the new RT bearer

If the resulting power is still below PrxTraget the RAB is admitted

rx_targetrx_ncrx_nc PPP +

In case the RAB can not be admitted it is putinto the queue


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DL Admission Overview

BTS sends periodically the total transmitted DL powerto the RNC

RNC compares the measured transmitted power levelsagainst the thresholds

If measured DL (PtxTotal) transmitted power exceedstarget thresholds (PtxTarget) AC can admit NRT RABsto the cell (no RT RABs can be admitted). The NRTRAB bitrates can not be increased and they remain atthe same level as after previous scheduling period

If measured DL (PTxTotal) transmitted power exceedsoverload thresholds (PtxTarget+PtxOffset) no RABscan be admitted and NRT bitrates are reduced untilPtxTotal reaches again PtxTarget

OverLoad

MarginalLoad

FeasibleLoad

In feasible load area the admission decision is based

on the power rise estimate of the new RT bearer

If the resulting power is still below PtxTraget theRAB is admitted

In case the RAB can not be admitted it is putinto the queue

OVERLOAD

AREA

MARGINALLOADAREA

FEASIBLELOADAREA

Load curve in DL

PtxTotal[dBm]

PtxTarget [dBm]

PtxTarget [dBm]+

PtxOffset [dB]

Cell maximum [dBm]

Load[0...1]

0 1

tx_targettxtx_total PPP +


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Admission Control in RRC Request

SRNC

RANAP

RRCRRM

PC

HC

PS

LC

RM

AC

PDCP

RLC

MAC

NBAP

RNSAP

FP

Iu UP

i i i i


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Admission Control in RAB Assignment

SRNC

RANAP

RRCRRM

PC

HC

PS

LC

RM

AC

PDCP

RLC

MAC

NBAP

RNSAP

FP

Iu UP

Ad i i C l F i l i


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Admission Control Functional overview

C ll Di t


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Call Disconnect

The disconnect described in the next slide are normal disconnects i.e. the UEreceives (sends) a disconnect message from (to) the network

CoreMobile Originated

Release


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NetworkRelease

RRC RRCRRC CONNECTION RELEASE (DCH)

RRCRRCRRC CONNECTION RELEASE COMPLETE



RANAPIU RELEASE COMMANDRANAP

IU RELEASE COMPLETE RANAPRANAP

RADIO LINK DELETION REQUEST NBAPNBAP

RADIO LINK DELETION RESPONSE NBAPNBAP

RELEASE REQUESTALCAP ALCAP

RELEASE RESPONSEALCAP ALCAP



The Call and all resources are released

Active AMR Call ongoing

DIRECT TRANSFER: CC RELEASE COMPLETERRCRANAP RANAPRRC

DIRECT TRANSFER: CC RELEASERRCRANAP RANAPRRC

DIRECT TRANSFER: CC DISCONNECTRRCRANAP RANAPRRC

CoreMobile Terminated

Release


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NetworkRelease







The Call and all resources are released

RADIO LINK DELETION REQUEST NBAPNBAP

RADIO LINK DELETION RESPONSE NBAPNBAP






DIRECT TRANSFER: CC RELEASE COMPLETERRCRANAP RANAPRRC



Active Set Update


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Active Set Update

The active set update (or soft/softer handover) is decided upon by the RNCbased on the measurement reports received from the UE.

Exactly how the trigger mechanism works depend on if the UE is in a Nokia or

Nortel area but the final result should be the same, namely adding, replacing or

deleting one or more cells from the active set.

Only Addition is shown

Signalling is slightly different for different case but only one is shown here. The

possible cases are Intra RNC Softer Handover (HO between cells under the same WBTS)

Intra RNC Soft Handover (HO between cells in different WBTS)

Inter RNC Soft Handover (HO between cells in WBTS in different RNCs)

Reporting event 1A: A Primary CPICH Enters the Reporting


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p g y p g

Range

4

Strongest CPICH in AS

time

Ec/Io

P CPICH 3

P CPICH 1

P CPICH 2

1

2

3

AdditionWindow

AdditionTime

AdditionReportingInterval

RNC

MeasurementReport

Add to

the AS?

no

ActiveSetWeightingCoefficient

Reporting event 1B: A Primary CPICH Leaves the Reporting


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Range

Strongest CPICH in AS

time

Ec/Io

P CPICH 3

P CPICH 1

P CPICH 2

1

2

3

DropWindow

DropTime

MeasurementReport

Remove thereported cellfrom the AS

Reporting event 1C: A non-active CPICH becomes better than


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an active primary CPICH

time

weakest CPICH3 in AS

Ec/Io

P CPICH 3

P CPICH 1

P CPICH 2

P CPICH 4

AS has 3 cells

ReplacementReportingInterval3

1

2

ReplacementWindow

ReplacementTime

Measurement

Report

RNC

ASupdate?

no

CoreNetwork

ACTIVE SET UPDATE

Addition A-I

Cell 1 Cell 2


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NetworkAddition A I

Handover

Control

RADIO LINK ADDITION REQUEST NBAPNBAP

RADIO LINK ADDITION RESPONSE NBAPNBAP

ALCAP ALCAPERQ

ECFALCAP ALCAP

Uplink SyncFP FP

FP FPDownlink Sync

Required for soft handover

Cell starts receiving

RRC RRCMEASUREMENT CONTROL

RRCRRCMEASUREMENT REPORT (DCCH): e1a

SYNCH INDICATION NBAPNBAP Required for soft handover

Cell startstransmitting


Admission Control

CoreNetwork

ACTIVE SET UPDATE

Addition A-II

Cell 1 Cell 2


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NetworkAddition A II

RRC RRCACTIVE SET UPDATE

RRC RRC

RRC RRCACTIVE SET UPDATE COMPLETE

RRC RRC


RRC RRC


RRC RRC

New Cell has been Added and Neighbour lists are updated

ACTIVE SET UPDATE

Addition B-IDRNC SRNC

Cell 1 Cell 2


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Handover

Control

RNSAPBRANCH ADDITION REQUESTRNSAP

Admission Control


RADIO LINK SETUP RESPONSENBAPNBAP

ALCAP ALCAPERQ

ECFALCAP ALCAP

BRANCH ADDITION PROCEEDINGRNSAPRNSAP

ALCAP ALCAPERQ

ECFALCAP ALCAP

Uplink SyncFP FP

FP FPDownlink Sync

RRC RRCMEASUREMENT REPORT (DCCH): e1a

Required for soft handover

Cell starts receiving


Admission Contro

ACTIVE SET UPDATE

Addition B-IIDRNC SRNC

Cell 1 Cell 2


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L1 SYNCHRONISATION

BRANCH ADDITION COMPLETERNSAPRNSAP

SYNCH INDICATION NBAPNBAP Required for soft handover

RRC RRCACTIVE SET UPDATE COMPLETE (DCH)

Cell starts

transmitting

New Cell is now added to the active set



RRC RRCACTIVE SET UPDATE (DCCH)

Admission Control for SHO


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Admission Control for SHO

Inter System Handover


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Inter System Handover

As for active set updates, the trigger mechanism for ISHO depends on if thenetwork is Nokia or Nortel. The following pages describes the signalling based

on the event driven mechanism, i.e. Nokia.

Inter System Handover: Procedure


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Inter System Handover: Procedure

HO Triggering Thresholds set in RNCHO Triggering Thresholds set in RNC

Event Triggered Coverage/Capacitybased HO fulfilled in RNC

Event Triggered Coverage/Capacitybased HO fulfilled in RNC

RNC commands selected UE(s) to startIS measurements

RNC commands selected UE(s) to startIS measurements

Measurements are done in

Compressed Mode (CM)

Measurements are done in


UE reports GSM cells withstrongest RSSI signals to RNC

UE reports GSM cells withstrongest RSSI signals to RNC

RNC makes HO decision and

commands UE to target cell

RNC makes HO decision andcommands UE to target cell

RSSI measurements and BSICverification for GSM cells

RSSI measurements and BSICverification for GSM cells

About 25 HO parameters

E.g. event1f (RSCP or EcN0)5 Coverage/Capacity reason: TxPwrDL,TxPwrUL, CPICH/RSCP, CPICH/EcN0, ULQuality

Physical Channel Reconfiguration Msg

Compressed mode needed to have time for

the IS measurements

More than one measurement report

Only one cell

Handover to GSM

Reporting events 1E and 1F: CPICH RSCP or CPICH EcN0


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epo t g e e ts a d : C C SC o C C c 0

time

Cell 1 Cell 2

Cell 3e.g.

P-CPI

CH

Rscp

1E: HHoRscpCancel

1E: HHoRscpCancelTime 1F: HHoRscpTimeHysteresis

Reporting event: 1E: A P-CPICH exceeds an absolute threshold (triggered if one)1F: A P-CPICH falls below an absolute threshold (triggered if all)

Reporting events 6A, 6B and 6D: UE Tx power


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p g , p

timetime to

trigger

UE

TxPower

UE Transmitted PowerTx Threshold

6B

6A

6Dmin(UEtxPowerMaxDPCH, P_MAX)

6A: The UE Tx power exceeds an absolute threshold6B: The UE Tx power falls below an absolute threshold6D: The UE Tx power reaches its maximum value

InterfreqUETxPwrTimeHyst

GSMUETxPwrTimeHyst



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p ( )

CM was introduced to WCDMA to allow inter-frequency (system) handovers CM is used to create idle periods (gaps) in the transmission during which cell

measurements on another frequency can be made

Gaps can be created using single or double frame approach

Because same data amount is sent in a shorter time more power is needed during CM(both in UE and BTS)

=> affects WCDMA coverage

Fast Power control information might be lost during the gap => higher Eb/No

=> affects WCDMA capacity

Compressed frames may be lost if power control is not set correctly

=> affects WCDMA quality

CM methods are Puncturing, Spreading Factor Halving and Higher Layer Scheduling

Normal frame Normal frame

Measurement gapMeasurement gap

Power /Data Rate CompressedMode

Normal frame

Maximum duration of measurements


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The duration of the maximum compressed mode duration time for each GSMRSSI and BSIC decoding measurement process in seconds is given by:

max_meas_interval (s) = GsmMaxMeasPeriod x GsmMeasRepInterval + 4 x

GsmMeasRepInterval

Gsm measurement (both RxLev and BSIC verif.) is stopped by expiration of

above window.

The ISHO procedure is considered to be unsucc and a new one can be activated

after GsmMinMeasInterval (2s) provided that RNC does not receive acancellation event

(7 s) (10 reports) (0.5 s)

CoreNetwork

Inter System

Handover - I


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MEASUREMENT CONTROL (DCCH)RRCRRC

RRC RRCMEASUREMENT REPORT (DCCH): Event 1f for first cell in Active Set

RRC RRCMEASUREMENT REPORT (DCCH): Event 1f for last cell in Active Set

Reporting event 1f triggers forfirst Cell in Active set

Reporting event 1f triggers forlast Cell in Active set

Decision to activate inter-RAT measurements.Determination of CM-pattern

RL RECONFIGURATION PREPARE NBAPNBAP

RL RECONFIGURATION READY NBAPNBAP

RL RECONFIGURATION COMIT NBAPNBAP

RRC RRCPHYSICAL CHANNEL RECONFIGURATION (DCCH)

RRC RRCPHYSICAL CHANNEL RECONFIGURATION COMPLETE (DCCH)

COMPRESSED MODE COMMAND

(CFN, TGPSI2) NBAPNBAP

GSM RSSIMeasurement

ISHO triggering (5reasons arepossible)

InitialCompressedModeConfiguration

MEASUREMENT CONTROL (DCCH): BSIC, CFN, TGPSI2RRCRRC

RRC RRCMEASUREMENT REPORT (DCCH): GSM RSSI, BCCH ARFCN

RRC RRCMEASUREMENT REPORT (DCCH): GSM RSSI, BCCH ARFCN


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Location Update


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Location Update does not occur during an AMR call but since it is sometimesconflicting with the AMR call setup the signalling flow for the Location update

is described in the next pages.

CSCoreNetwork

Location Update

I


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Admission Control



ALCAP ALCAPERQ

ECFALCAP ALCAP


L1 SYNCHRONISATION



INITIAL DIRECT TRANSFER (MM LOCATION UPDATE)

RRC RRC

Uplink SyncFP FP

FP FPDownlink Sync


RANAP RANAP

INITIAL UE MESSAGE

SCCP SCCP



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Inter RAT Cell reselection


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Qsearch_I and Qsearch_P define thresholds. The threshold value alsoindicates, when the measurements have to be initiated and performed. The

measurements are either started, when the serving cells RLA is below or above

the threshold value. The default value is 15.

FDD_Qoffset and FDD_GPRS_Offset define offset values, which have to beadded to the RLA of the serving and non-serving GSM cells. The result is

compared with the RSCP value of the WCDMA cell. The default parameter is 0.

FDD_Qmin defines a minimum CPICH Ec/No threshold for WCDMA cell for cell re-selection.

FDD_REP_QUANT defines the reporting quantity for UTRAN cell (1=Ec/No or

0=RSCP, default: 1).

3G_Search_PRIO is used to inidicate to the MS if 3G cells can be looked forwhen BSIC decoding is required. (0=no, 1=yes, default: 1)

Parameter mapping


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Fdd_Qmin mapping

Aif parameter 0 1 2 3 4 5 6 7

Fdd_Qmin (old) [dB] -20 -19 -18 -17 -16 -15 -14 -13

Fdd_Qmin (new) [dB] -20 -6 -18 -8 -16 -10 -14 -12

New mapping from 05.08 [late 2003]:

UEs have to support new parameter range !

Fdd_Qmin

QSearch_I/P

PS CoreNetwork

CS CoreNetwork

Inter RAT Cellreselection I


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Admission Control


L1 SYNCHRONISATIONSYNCH INDICATION NBAPNBAP


INITIAL DIRECT TRANSFER (MM LOCATION UPDATE)RRC RRC


RANAP RANAP

INITIAL UE MESSAGE

SCCP SCCP


INITIAL DIRECT TRANSFER (GPRS MM ROUTING AREA UPDATE REQUEST)

RRC RRC

RADIO LINK SETUP

SCCP: CONNECTION REQ

RANAP RANAPINITIAL UE MESSAGE

SCCP SCCP

SCCP: CONN. CONFIRMSCCP SCCP

PS CoreNetwork

CS CoreNetwork

Inter RAT Cellreselection I

DIRECT TRANSFER (MM Authentication Request)


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DIRECT TRANSFER :MM TMSI Reallocation CompleteRRCRANAP RANAPRRC

DIRECT TRANSFER (MM Authentication Response)RRCRANAP RANAPRRC

DIRECT TRANSFER (MM Authentication Request)RRCRANAP RANAPRRC

DIRECT TRANSFER : MM Location Update AcceptRRCRANAP RANAPRRC

DIRECT TRANSFER (GPRS MM Authentication and Ciphering Request)

RRC RANAPRRC

RANAPDIRECT TRANSFER (GPRS MM Authentication and Ciphering Response)

RRC RANAPRRCRANAP

DIRECT TRANSFER : GPRS MM Routing Area Update AcceptRRC RANAPRRCRANAP

DIRECT TRANSFER : GPRS MM Routing Area Update CompleteRRC RANAPRRCRANAP


IU RELEASE COMPLETERANAP RANAP



RRCRRC RRC CONNECTION RELEASE COMPLETE


RADIO LINK DELETION

Methods used while analysing the log files


55/123



Analysing/opening the drive test log file (e.g. ASCOM, TEMS, Actix) Analyse current network configuration (Sites, adjacencies etc)

Access to network configuration information

Analysis counter metrics

Use of more

than one

approach is notforbidden

Summary: A 3G Voice Call Setup Phase for MTC


56/123



ASU is possible after

RRC connection is

established but not

during Radio bearer

setup (seen from the

RNC side)

RRC RRCPAGING TYPE 1 (PCCH)

RRCRRC RRC CO CH)NNECTION REQUEST (CC

RRC C P (FACH)ONNECTION SETU RRCRRC

RRCRRCRRC CONNE LETE (DCH)CTION SETUP COMP

INITIAL DI aging Response)RECT TRANSFER (PRRC RRC

SECU PLETERITY MODE COMMAND COMRRC APRANRRC

SECURITY MODE COMMANDRRC APRANRRC

DIRECT TR SETUPANSFER: CCRRC APRANRRC

DIRECT TR LL CONFIRMEDANSFER : CC CARRC APRANRRC

RRC RRCRADI P (DCCH)O BEARER SET-U

RRCRRC RADIO BE LETE (DCCH)ARER SET-UP COMP

DIRECT TR ACKNOWLEDGEANSFER: CONNECTRRC APRANRRC

DIRECT TR LERTINGANSFER: ARRC APRANRRC

DIRECT TR ONNECTANSFER: CRRC APRANRRC

Summary: A 3G Voice Call Setup Phase for MOC


57/123



ASU is possible after

RRC connection is

established but not

during Radio bearer

setup (seen from the

RNC side)

RRCRRC RRC CO CH)NNECTION REQUEST (CC

RRC C P (FACH)ONNECTION SETU RRCRRC

RRCRRCRRC CONNE LETE (DCH)CTION SETUP COMP

INITIAL DIRECT TRANSFER M Service Request)(MM CRRC RRC

SECU PLETERITY MODE COMMAND COMRRC APRANRRC

SECURITY MODE COMMANDRRC APRANRRC

DIRECT TR SETUPANSFER: CCRRC APRANRRC

DIRECT TR LL PROCEEDINGANSFER : CC CARRC APRANRRC

RRC RRCRADI P (DCCH)O BEARER SET-U

RRCRRC RADIO BE LETE (DCCH)ARER SET-UP COMP

DIRECT TR ACKNOWLEDGEANSFER: CONNECTRRC APRANRRC

DIRECT TR LERTINGANSFER: ARRC APRANRRC

DIRECT TR ONNECTANSFER: CRRC APRANRRC

A 3G Voice Call Active Phase and Disconnect


58/123



Measurement reports Event driven in Nokia

Periodic in Nortel

Active set updates

Additions Removals

Replacements

Intersystem Handovers

Compressed mode trigger GSM measurements

ISHO Command

Success?

Disconnection (Unexpected) Disconnected by the network?

Disconnected by the user?

Typical failures


59/123



Missing message (e.g. no L3 messages for several minutes) Cell reserved (Not seen for a while but it is an easy check)

Collision between LAC update/Registration and Call attempt

Call failures because of user busy (MOC)

Calls disconnected by measurements system

Calls disconnected by the network

Missing radio bearer setup message

Missing adjacencies leading to a call failure or a dropped call

Poor coverage/quality

Coverage related (poor RSCP/EcN0)

Quality related (poor EcN0/good RSCP)

Cells covering unwanted areas

Overshooting cells

Large back loops for some cells

Have in MIND


60/123



What you see is only as seen from the UE perspective Not RNC logs

What you see in the log file is not necessarily all of what the

phone would be seeing

This is especially the case when evaluating the RSCP and EcN0

values.

In the following examples references are given to ASCOM,

TEMS, COUEI, QVP, ACTIX etc. but most of the examples canmost likely be observed in several of the tools.

Typical failures


61/123



Missing message (e.g. no RRC messages for several minutes) Cell reserved (Not seen for a while but it is an easy check in Actix)











Overshooting cells


Missing messages (I)


62/123



Three types of cases No L3 messages at all

Most L3 messages are available but specific messages are missing

Most L3 messages are available but now and then a single message is missing

Can happen in any part of call.

When no L3 messages is seen for a long period of time it is in most case due to

measurement system failure and often the final result is a restart of the

measurement system (and phone). (seen with ASCOM)

If the same L3 message is missing again and again this can be due to the

import function of the analysing tool (seen with Actix)

When a single message is missing here and there is no big problem. E.g. it canbe that the radio bearer setup message is missing while the Radio bearer setup

complete is in the log file. Mainly a problem for automated scripts used to

identify failed/dropped calls.

Missing messages (II)


63/123



In general missing L3 messages is not a cause for a dropped or failed call butsince we use automated scripts/tools, calls might be wrongly identified as

failed or dropped.

One type often seen is that there are no L3 messages for several min and in the

internal messages a Receive inband measurements is seen. After a while thephone is then reset by the measurement system (ASCOM).

Missing messages (III): MOC Drop Call (08:23:55:080)


64/123



No L3 message for >1min and the Receive Inband measurement case!!

Phone is reset by measurement system

Thursday Mar 23rd

Typical failures


65/123



Missing message (e.g. no L3 messages for several minutes) Cell reserved (Not seen for a while but it is an easy check)











Overshooting cells


Cell reserved (I)

If th t ll d i t t O t l l ifi i d


66/123



If the parameter cell reserved is set to Operator use only only specific simcards

will be allowed to camp in the given cell

Impact of wrong setting is general that the UE can not camp on the 3G cell and

calls will therefore be made either on 2G cells or second best 3G cells.

Previously a big problem with wrong settings in the network Today only cells that should actually have it set will have it set?

Check the parameter setting from the SysInfo Type 3 message In Actix it is

very fast to make a plot of the settings and identify cells with the specialsetting.

Note that this is just to check if there could be a problem. The real check of this

parameter should be done on the network configuration database since in the

drive test the SysInfo Type 3 will only be logged for a subset of the cells locatedalong the route (the cell passed in idle mode!)

Also have in mind that in most tools all parameters send to the phone can be

analysed from the logged messages

Monday Nov 7th

Cell reserved (II) Example


67/123



o day o

O2 07921495158Cell Reserved information from

SysInfoType 3 message

O2_0711_M11_Slough-Uu_Technology_Mode (N/A)

UMTS Mode (184586)

GSM mode (23511)

O2_0711_M11_Slough-Uu_RRC_CellAcces sRestriction_cellReservedForOperatorUse (no units)

( RRC_reserv ed (5)

( RRC_notReserved (634)

For this drive test is seems asthere where only a problem

around Heathrow..

Monday Nov 7th

Typical failures


68/123



Missing message (e.g. no L3 messages for several minutes) Cell reserved (Not seen for a while but it is an easy check in Actix)






Missing adjacencies leading to a call failure or a dropped call Poor coverage/quality




Overshooting cells




69/123



Two types of collisions are seen The UE is not registered with the network when it sends the RRC connection request

The UE sets up the voice call while it is in the process of doing a registration/LU

First case leads to a rejection by the network (IMSI Unknown in network)

Second case results in a failed call somewhere in the setup phase

The problem can be seen in the log file as if one RRC connection is used for both the

LU and the call and when the LU is finished the RRC connection is disconnected

resulting in the failed/dropped call. Often the RRC connection cause is Registrationindicating that there is a collision because we are looking at a call failure.

Next couple of slide shows very brief examples of these two cases

CoreNetwork


Signalling in caseof unknown IMSI


70/123



RRCRRC

Admission Control


L1 SYNCHRONISATION




RANAP RANAP

INITIAL UE MESSAGE

SCCP SCCP

RADIO LINK SETUP

DIRECT TRANSFER : CM SERVICE REJECT (cause: IMSI unknown in VLR (Hex 04)RRCRANAP RANAPRRC

DIRECT TRANSFER (MM Identity Response)RRCRANAP RANAPRRC

DIRECT TRANSFER (MM Identify Request)RRCRANAP RANAPRRC

Note only

messages seen in

log is shown





MOC Failed Call (07:59:09:420)

3 RRC


71/123



3 RRCConnectionRequest(8:59:09:420,8:59:11.530 and8:59:12.620) beforeanswer from network

Then call is rejecteddue to IMSI unknownin VLR (Hex 04)

Right after aregistration takes

place so it seems thatthe call fails due tomissing registration.

Friday Dec 16th

MTC Failed Call (11:50:38:340)

Paging to mobile at


72/123



Paging to mobile at

11:50:36:510 on SC482 (RNC 63).

Cell reselection from482 to 315 in RNC 65

UE sets up RRCconnection for call onSC 315 but thensends both a requestfor Registration and apaging response.

When LU is finished,

the RRC connection isdisconnectedresulting in a failedcall.

Tuesday Feb 28th

Typical failures


73/123



Missing message (e.g. no L3 messages for several minutes) Cell reserved (Not seen for a while but it is an easy check in Actix)










Overshooting cells




74/123



Seen as a disconnect after the radio bearer setup complete with cause userbusy

Exact reason is unknown but e.g. out of sync between the two phones could

cause this problem

Example of signalling is shown on the next two pages. In general this type of

failure is identified by the rejection cause in the disconnect message.

CoreNetwork


USER BUSY

I


75/123



Admission Control


L1 SYNCHRONISATION




RANAP RANAP

INITIAL UE MESSAGE

SCCP SCCP

RADIO LINK SETUP

Note that only

messages relevant

for log is shown


Admission Control


RADIO LINK RECONFIGURATION

SECURITY MODE COMMAND COMPLETERRCRANAP RANAPRRC



CoreNetwork

USER BUSY

II



76/123



Note that only

messages relevant

for log is shown

RRCRRC RADIO BEARER SET-UP COMPLETE (DCCH)








DIRECT TRANSFER: CC RELEASE COMPLETE RRCRANAP RANAPRRC



RADIO LINK DELETION

Typical failures

Missing message (e g no L3 messages for several minutes)


77/123



Missing message (e.g. no L3 messages for several minutes)

Cell reserved (Not seen for a while but it is an easy check in Actix)










Overshooting cells


Calls disconnected/failed by measurement system


78/123



Causes for these failures/drops can be: UE is reset by the measurement system

UE is reset by the user

The measurements are stopped

Either by drive tester

Or by the measurement system itself

For ASCOM files these types of failures are often seen when there are lots of log

files e.g. the number of log files for the Slough M11 route is normally 1 to 2 filesbut sometimes 5+ (up to 15/20 files) are seen.

The problem can occur in any part of the call and in the log file it is seen as

sudden loss of messages and information about restart of measurement

and/or phone in the internal messages.

Typical failures

Missing message (e g no L3 messages for several minutes)


79/123














Overshooting cells




80/123



Calls are seen to be disconnected from the network side There can be several reasons for this

Core network problems

UL Radio problems

Transmission problems

Etc.

Often it is not easy to identify based on the UE logs alone why the call were

disconnected by the network Next couple of slides show one example with no explanation and one with a

possible explanation

Generally more investigation of the cell(s)/site(s) involved is needed

CoreNetwork

RRC Disconnectedby Network

Established Call


81/123







Note only

messages seen in

log are shown

Network Disconnect Example: MOC Dropped Call (12:35:30:880)


82/123



Disconnected by Network

SC 368 and SC 362 in AS at time of

disconnect right after an ASU to remove

369.

Monday Mar 20th

Network Disconnect Example: MOC Drop Call (11:45:21:750)

SC 11 and 258 in AS


83/123



Call is released less thana second after the RBsetup complete

Unknown reason forrelease.

Check uplinkperformance of thisinvolved cells

Friday Mar 24th

Typical failures



84/123



g g ( g g )











Overshooting cells



Call setup gets to


85/123



-> Downlink direct transfer Call Proceeding (MOC)

-> Downlink direct transfer Call confirmed (MTC)

Then one or more measurement report might be seen before the UE switches to

idle mode. No radio bearer message is seen by the UE and the call disconnects

Two different scenarios seen

Radio environment is poor (EcN0 and RSCP)

Radio environment is good but BER deteriorates very fast to >50%

The first case is generally a question of coverage/interference or perhaps amissing adjacency

The second case is still under investigation (occurs often in Nokia area) andseems to be cause by that the radio link synchronisation is lost during theRadio bearer setup (message is sent from RNC to Node B).

CoreNetwork

RRCRRCRRC CONNECTION REQUEST (CCCH)

Admission Control

Missing RadioBearer Setup - I


86/123




L1 SYNCHRONISATION

RRCRRC

RRC CONNECTION SETUP COMPLETE



RANAP RANAP

INITIAL UE MESSAGE

SCCP SCCP

RADIO LINK SETUP

Note that only

messages relevant

for log is shown


Admission Control


RADIO LINK RECONFIGURATION

SECURITY MODE COMMAND COMPLETE RRCRANAP RANAPRRC




RRC RRCMEASUREMENT REPORT (DCCH)


87/123



Typical failures



88/123













Overshooting cells



Since ASU can take place in the call setup phase missing adjacencies can give


89/123



problems in both setup and active phase

It can sometimes be difficult based solely on the log files to determine if the

failure/drop is caused by a missing adjacency (having scanner data helps a lot

in these cases) Following slides shows 7 examples of missing adjacencies identified over the

last 6 months.

Majority causes dropped calls. Mainly because the time spent in setup phase issmaller so less chance of experience the problem of a missing adjacency and

also because the available information (not having scanner data) in the setup

phase is limited so it might be more difficult to identify a missing adjacency in

that phase.

Missing ADJ Ex 1: MOC Dropped Call (10:58:14:010)

Call is started at SC 345 (CellId 21704, RNC 63)

at RSCP/EcN0 of 59/ 4


90/123



at RSCP/EcN0 of -59/-4 EcN0 drops slowly to about -12 dB and then it

drops rapidly to -22 dB

E1a for SC 108 happens just before the valueof -22 is seen.

But looks like SC 109 (among others) ismissing from the neighbour list!!

Monday Nov 14th

1411_O2_Slough_M11-Uu_Technology_Mode (N/A)

UMTS Mode (206664)

GSM mode (21221)

1411_O2_Slough_M11-CPICH_A llSets_UE_EcNo_For_SC_345 (dB)

( Below -18.0 (10)

( >= -18.0 to < -15.0 (5)

( >= -15.0 to < -13.0 (0)

( >= -13.0 to < -11.0 (4)

( >= -11.0 to < -9.0 (11)

( >= -9.0 to < -7.0 (2)

(A bove -7.0 (40)


It does look like SC is missing a

couple of neighbours


91/123



couple of neighbours. It does also look as if the whole

neighbourplan of this sector (andperhaps site) should berevisisted)

Note that the shown ADJS data isup to 2 weeks old

Monday Nov 14th

89

90

161162 116

117

345346

153

154 41

42

169170

305306

76

77

329330108

109

401402

24

339

88

160 115

344

152

40

304

75

328

440

187

340341

168

107

400


Call is started at SC 306 (CellId 31836, RNC 63)

at RSCP/EcN0 of 59/ 4


92/123



at RSCP/EcN0 of -59/-4 UE changes to SC 305 (after having both 305

and 306 in AS)

EcN0 drops fast to about -24

Problem is missing ADJS (see next slide for

ADJS). SC 346 is obviously missing while a fewother should be added as well.

Tuesday Nov 15th

1511_O2_M11_Slough-Uu_Technology_Mode (N/A)

UMTS Mode (197377)

GSM mode (52468)

1511_O2_M11_Slough-CPICH_A llSets_UE_EcNo_For_SC_305 (dB)

( Below -18.0 (21)

( >= -18.0 to < -15.0 (12)

( >= -15.0 to < -13.0 (5)

( >= -13.0 to < -11.0 (1)

( >= -11.0 to < -9.0 (5)

(>= -9.0 to < -7.0 (1)

( Abov e -7.0 (18)


409


93/123



Tuesday Nov 15th

89

90

161162 116

117

345346

0

153

154 41

42

169170

305306

76

77

329330108

109

402339

88

160 115

344

59

152

40

304

75

328

440

187

340

168

107

216 32

40

Missing ADJ Ex 3: MTC Failed Call (09:21:35:650)


94/123



Cell is initiated on SC 216 (CellId 11484). SC 217 is added to the AS

Call fail due to missing ADJS. MR with event e1a is send for SC 203 but this SC points

away from the scene and the EcN0 of SC216 and SC217 is already very low when this

happens Sites neighbour planning should be revisited.

For details on the ADJS see following slide.

SC 205 seems to one of the missing ADJS for SC216 and perhaps SC 217

Wednesday Nov 16th

Missing ADJ Ex 3: MTC Failed Call (09:21:35:650)

318 318


95/123



249

250

217

218

36

37

204

205

349

164

165

225226

124125

393

137138

336

248

216

35

203

163

224

123

392

432

34

136

336338

Wednesday Nov 16th

249

250

217

218

36

37

204

205

164

165

225226

124125

393

137138

336

248

216

35

203

163

224

123

392

43234

136

336338

ADJS (blue) of SC 216 (red) ADJS (blue) of SC 217 (red)

Missing ADJ Ex 4: MTC Dropped Call (10:33:35:770)


96/123



Failed ISHO: Mobile goes into Compressed modetwice. Second time the mobile send several MR withverified BSIC but there are no reply with ISHOcommand. At this point the EcN0 is very poor (-24dB)

There are 2 failed CM and several unanswered MRe1a (due to the very poor quality towards the endof the call).

Coverage/quality problem missing 2G neighbours?

Note: Blue star correspond to a Physicalreconfiguration command triggered by poor EcN0

Wednesday Nov 16th

1611_O2_Slough_M11-Uu_Technology_Mode ( N/A)

UMTS Mode (157710)

GSM mode (64902)

1611_O2_Slough_M11-ASCOM_CELL_RESELECTION (no units )

( 3G->2G CR (7)

( 2G->3G CR (34)

( 3G->2G HO (27)

1611_O2_Slough_M11-ASCOM_CM_TRIGGER_CAUSE ()

8 Above 3 (0)

8 >= 2 to < 3 (33)8 >= 1 to < 2 (0)

8 Below 1 (0)

Missing ADJ Ex 4: MOC Dropped Call (11:34:26:410) Call drops with SC 75 107 and 305 in AS.

Problem seem to be missing ADJS between SC 107d SC 77 Th HO d t h til SC 75


97/123



g Jand SC 77. The HO does not happen until SC 75 comesinto the AS and at that point the quality is alreadyvery low. ASU putting SC 75 into the AS happens atEcN0 of -20!!

In short check ADJS plan in the area (see next two

slides for more details of the ADJS plan as of 30/11)

Wednesday Nov 30th


32


98/123



Wednesday Nov 30th

89

0

161162 116

117

345346

153

154 41

42

305306

76

77

329330108

109

401402

368

24

88

160 115

344

152

40

304

75

328

440

176

291

187

467

370

28

29

107

400

177178

292293

240

392

8

9 10

ADJS (blue) of

SC 107 (red)


392


99/123



Wednesday Nov 30th

61 116

117

345346

153

154 41

42

305306

76

77

9108

109

401402

368

24

99

115

344

152

40

304

75

440

387

176

291

323

360

200

139

352 5

64

187467

369

370

28

29

100

101

107

388

389

400

177178

292293

322 362

201

202

140141

353

35461

6566

144

240

392

8

9 10

ADJS (blue) of

SC 75 (red)


Call drops with SC 24, 210 and 405 in the AS

The is one of the drops/failures that happens


100/123



every week on M4

Checking adjacencies shows that most arealready in the list but perhaps SC 297 shouldbe part of the ADJS list of SC 24 (see ADJS as of

30/11 on next slide)

Wednesday Nov 30th SC 24 Lower set

SC 210 Middle set

SC 405 upper set


147

310 281282148


101/123



Wednesday Nov 30th

320

40

2

299

496

480

192

416

232

296

65

24

352

160

360

96

40

81

112

384

256

16

75

208

184

104

328

315

264

405

41

42

217

218

40

300301

497

498

481

482

193

194

128

129

130

321322

408

233234

297298

66

67

25

26

353

354

161

162

361

362

97

98

4142

8283

113114

385386

1718

7677

209210

105106

329330

316317

408ADJS (blue) ofSC 24 (red)

Missing ADJ Ex 6: MTC dropped call (09:08:12:400)

Call is started on SC 306. Then SC 305 is added

and a little later 306 is removed as UE passesthe site (10181)


102/123



the site (10181)

SC 305 becomes very bad (on figure on theright, the upper line is 306 while the lowerline is for SC 305)

Missing ADJS to 344 and 346 (see next page)

Friday Dec 16th

Missing ADJ Ex 6: MTC dropped call (09:08:12:400)

248


103/123



Friday Dec 16th

89

90

161162116

117

345346

4950

60

61

153

154 41

42

169170

145

146

305306

76

77

329330108

109

5

401402

24

339

88

160 115

344

48

59

152

40

144

304

75

328

440

409

1

291

187

29

340341

168

107

216

24

32

400

292293

392

ADJS (blue) of

SC 305 (Red)


UE sends several MR e1a but to late


104/123



because SC 192 is already bad.

Most likely caused by a missing ADJS

between SC 250 and SC 192 (see next

slide)

Monday Feb 27th


67, (328),

67, (3267, (330), (31

67, (312), (11392), (004594)

67, (313), (21392), (004594)

67, (314), (31392), (004594)

67, (304), (11520), (011851)

67, (336), (11443), (018599)


105/123



Monday Feb 27th

67, (56), (11299), (000886)

67, (57), (21299), (000886)67, (58), (31299), (000886)

67, (216), (11300), (000888)

67, (217), (21300), (000888)67, (218), (31300), (000888)

67, (170), (11525), (001565)

67, (171), (21525), (001565)

, (172), (31525), (001565)67, (267), (13400), (003052)

67, (268), (23400), (003052)67, (269), (33400), (003052)

67, (168), (11305), (003184)

67, (169), (21305), (003184)

67, (170), (31305), (003184)

67, (128), (11306), (003404)

67, (129), (21306), (003404)

67, (130), (31306), (003404)

67, (120), (11309), (004497)

67, (121), (21309), (004497)67, (122), (31309), (004497)

67, (136), (11310), (004873)

67, (137), (21310), (004873)

67, (138), (31310), (004873)

67, (240), (11395), (004874)

67, (241), (21395), (004874)67, (242), (31395), (004874)

67, (48), (11311), (004875)

67, (49), (21311), (004875)

67, (50), (31311), (004875)

67, (81),

67, (67, (83), (3

67, (248), (11447), (005460)

67, (249), (21447), (005460)

67, (250), (31447), (005460)

67, (160), (11402), (00

67, (161), (21402), (00

67, (162), (31402), (005479)

67, (352), (11194), (01207

67, (353), (21194), (012075

67, (354), (31194), (012075)

67

6

66,

666, (22

67, (200), (11324), (033452)

67, (201), (21324), (033452)

67, (202), (31324), (033452)

67, (331), (11898), (000395)67, (332), (21898), (000395)

67, (333), (31898), (000395)

67, (176), (11302), (001472)

67, (177), (21302), (001472)67, (178), (31302), (001472)

67, (91), (11389), (002194)

67, (92), (21389), (002194)

67, (93), (31389), (002194)

67, (192), (11298), (000014)

67, (193), (21298), (000014)

67, (194), (31298), (000014)

Typical failures




106/123





Calls disconnected by measurements system Calls disconnected by the network


Investigation ongoing showing loss of radio link synchronisation




Cells covering unwanted areas Overshooting cells



Actual poor coverage is mainly seen on the border of the 3G coverage area.

The grouping of the problems is not necessarily precise but it is similar to the split-up


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shown in the table below.

Following slides shows some examples of poor coverage/quality

Note that often a missing adjacency can look like poor coverage but is poor quality.

RSCPGood Poor

Good No problem Possible problem

Poor Interference/quality Interference/Coverage

EcN0

O2_Bham_0711-Uu_Technology_Mode (N/A)

UMTS Mode (122 410)

GSM mode (36097)

SC 130 is only cell in AS. Within 1 sec SC 130 drops

from EcN0 of -7 to -13 and a second later it is at -23. SC 104 is at the same time in monitored set starting

f b 13 b di 7 h h ll d

Poor coverage/quality ex 1: MTC Dropped call (13:35:29:360)


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O2_Bham_0711-CPICH_A llSets_UE_EcNo_For_SC_130 (dB)

( Below -18.0 (76)

( >= -18.0 to < -15.0 (43)

( >= -15.0 to < -13.0 (34)

( >= -13.0 to < -11.0 (46)

( >= -11.0 to < -9.0 (32)

( >= -9.0 to < -7.0 (22)

( A bove -7.0 (18)

from about -13 but ending at -7 when the call drops

Conclusion: The drop is caused by a sudden drop inquality. Possibly by going around the corner

Monday Nov 7th

Poor coverage/quality ex 2: MOC Failed Call (12:18:32:970)

Call initiated on SC 186 (Cell Id 31007 RNCId 61). SC 185 is then added to AS


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Call initiated on SC 186 (Cell Id 31007 RNCId 61). SC 185 is then added to AS

After RAB setup Complete the UE sends several e1a reports for SC 56 and SC 233 but

the EcN0 of the active set is already at about -15 and drops to -24dB within 1-2

seconds. Seems to be interference/site problems based on the fact of very low EcN0 at a RSCP

level of -89 to -92dB (see next slide for more details)

Wednesday Nov 16th

Poor coverage/quality ex 2: MOC Failed Call (12:18:32:970)

AS and MR information


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Wednesday Nov 16th

SC EcN0 RSCP

Poor coverage/quality ex 3: MOC Dropped Call (09:08:09:790)

UE is in a known poor coverage area. UE ishanging on to a 3G cell about 7 5 km away


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hanging on to a 3G cell about 7.5 km away(see next slide for available cell and ADJS).There have been several attempts to find a2G cell but they are unsuccessful.

Check ADJGs and/or reduce the coverage ofthe site

Friday Mar 3rd

Poor coverage/quality ex 3: MOC Dropped Call (09:08:09:790)

Drop Call here


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Friday Mar 3rd

Call active on this site

Slide with signal from Actix for previous page


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Typical failures





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Overshooting cell example: MTC Failed Call (13:53:51:530)

UE starts the call on SC 440 (cellid 11907,

RNC 63) which is far away (about 11km).


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RNC 63) which is far away (about 11km).

UE reports 293 which is in the local area

but actually RNC believes it to be the ADJS

of cell 11907

Wednesday Mar 1st

Overshooting cell example: MTC Failed Call (13:53:51:530)


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Wednesday

Mar 1st

Mobile is here

Trying to connect

to this cell

Typical failures





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OTHER

MOC Dropped Call (17:02:37:460)

Call is disconnected by the user/UE.

NW sends CC Alerting and CC Connect


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NW sends CC Alerting and CC Connect

for ps_Domain and UE responds with

RRCStatus protocolErrorInformation

Monday Feb 27th

Signalling with ProtocolError Information


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MTC Dropped Call (15:44:05:520)

Call is started at SC 26 (CellId 31312, RNC 67).

ASU to (26,210) -> (210) -> (210,26) ->(210,77,26) -> (297,210,26) -> (297,77,210) ->

(297)


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(297)

Rapid drop in EcN0, e1f for SC 297 but EcNo at

-19 to -21 and the call drops while doing the2G measurements

O2_Slough_M11_0811-Uu_Technology_Mode (N/A)

UMTS Mode (194297)

GSM mode (37555)

O2_Slough_M11_0811-CPICH_A llSets_UE_EcNo_For_SC_297 (dB)

( Below -18.0 (9)

( >= -18.0 to < -15.0 (2)

( >= -15.0 to < -13.0 (1)

( >= -13.0 to < -11.0 (2)

( >= -11.0 to < -9.0 (5)

( >= -9.0 to < -7.0 (8)

( Abov e -7.0 (13)

Tuesday Nov 8th

coaching session_3g voice call analysis_v04

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