118939337 isho training

1 NOKIA Presentation_Name.PPT / DD-MM-YYYY / Initials Company Confidential

ISHO Training


Contents

Introduction

Compressed mode case

ISHO Parameters optimisation

ISHO Signalling Steps


Measurement triggering in WCDMA

All together five different quality and/or coverage based triggers specified:

GSM handover caused by CPICH Ec/No (event 1F) GSM handover caused by CPICH RSCP (event 1F) GSM handover caused by Ue Tx power (event 6A) GSM handover caused by DL DPCH power (NodeB radio link

measurement) GSM handover caused by UL DCH quality (UL outer loop power

control)

If two or more of the above indicated quality and/or coverage causes are present simultaneously, the handover cause which has triggered first has the highest priority.

RNC shall determine priorities between inter-frequency and inter-RAT handovers on the basis of Service Handover IE received from the CN.

Should be handed over to GSM: ISHO > IFHO Should not be handed over to GSM: ISHO < IFHO Shall not be handed over to GSM: ISHO < IFHO


WCDMA compressed mode methods

TGPL1 = 4 frames (Transmission Gap Pattern Length)

TGPL2 = 0 TGPL2 identical with TGPL1, in RAN1.5

TGL = 7 transmission gap lenght in slots, in RAN1.5

TGD = 0 gap distance, in RAN1.5 => only one gap per TGP

Transm issionTransm ission gap 2

gap 2

TGSN TGSN

TGL2 TGL2

TG pattern 2#TGPRC

gap 1Transm ission Transm ission

gap 1

TGD TGD

TGPL1 TGPL2

TG pattern 1 TG pattern 2

TGL1 TGL1

#1 #2 #3 #4 #5TG pattern 1TG pattern 1 TG pattern 2 TG pattern 1 TG pattern 2


WCDMA compressed mode methods Higher Layer Scheduling (HLS)

Used both in UL and DL In RAN1.5 only for NRT PS data Doesnt cause extra load Reduces DCH user data changing the TFCSs HLS and HLS data rates possible

Puncturing DL only Implemented in RAN1.5 but no plans to test

Halving the Spreading Factor (SF/2) Used both in UL and DL Doubles temporarily the physical channel data rate Done if new channelisation code is available from the code tree in DL OR

alternative scrambling codes are used (parameter: AltScramblingCodeCM) Limited CM strategy in RAN1.5:

AMR 12.2 kbit/s TGL = 7 slots PhysicalChannelReconfiguration used in RRC


WCDMA compressed mode methodsPuncturing (Double Frame):

Higher layer scheduling (Double Frame):

Halving the spreading factor (Single Frame):

CM on CM offGaps

CM on

CM on

CM off

CMoff

Punctured frames

Normal frames

Gaps

New TFCS constructed TFCS original

SF/2 Original SF

Gaps

t

. .

10 ms

DTX

P

Example of compressed mode methods in downlink


WCDMA compressed mode methodsHigher layer scheduling (Double Frame):

Halving the spreading factor (Single Frame):

CM on

CM on

CM off

CMoff

Gaps

New TFCS constructed TFCS original

SF/2 Original SF

Gaps

t

P

Example of compressed mode methods in uplink


Contents

Introduction


ISHO Parameters Optimisation



Compressed mode parameters

Compressed mode parameters for IS-HO (RSSI& BSIC measurements):

TGSN: 4 slots

TGL1(2)= 7 slots

TGPL1(2)= 4 frames

Tgd= undefined (one gap per TGP)

TGPL1(TGPL2)

1 Frame 1 Frame 1 Frame 1 Frame

7 slots gap


Measurement description

Measurements uner Kutoja-2 cell (sc=201)

Two routes: Route 1 (LOS) and Route 2 (NLOS) were followed. Average speed= 40kph

For each route: three measurements without CM and three measurements with CM were done.

IS-HO triggers were set to high thresholds to keep the PC inside the dynamic range.

Route 1

Route 2


UL Power control during compressed mode

UE Tx power in Compressed mode

BLER was kept to BLER target (1%)

TGPL format as expected

Ue Tx Power ([dBm])


Average SIR variation with compressed mode (CM)

4.293.44

4.95 4.59

-1.50

0.50

2.50

4.50

6.50

Route1 Route2

Route

A

v

e

r

a

g

e

S

I

R

[

d

B

]

Without CMWith CM


UL SIR Average SIR obtained in each route during compressed mode:

-Route1 (LOS) : SIR rises 0.7 dB compared to NO CM-Route2 (NLOS): SIR rises 1.2 dB compared to NO CM

Average SIR variation during CM is bigger in NLOS



UE Tx power The measurements were done using one link only (no SHO)

Average speed was 30 Kmph ISHO parameters

CPICH EcNo threshold = -7dBCM duration time was forced to last to 20 seconds approx.

Measurement descriptionThree measurements were done without CM (ISHO

triggers disactivated)Three measurements were done with CM.

Sapo



UE Tx power The UE Tx power during CM was compared with the UE Tx power with CM disabled in 4 different zones along the route (see below figure)

In average, the UE transmits 1.3 dBhigher in compressed mode than with CM disabled.

Note: This result is for single link CM

-10.5

4.1

-17.1

-3.3

3.0

-13.6

-3.0

-11.0

-20

-15

-10

-5

0

5

10

1 2 3 4UE Tx pow er in CM

UE Tx powerwithout CM

Average UE Tx power with CM and without CM

with CM

without CM


UE Tx Power in CM+SHO

A special configuration was used to create the scenario for simultaneous CM and SHO processes.

ISHO parametersCPICH EcNo threshold = -5dBCM duration time was forced to last 20 seconds approx.

SHO parametersAddition window= 4 dBDeletion window= 9 dBDeletion time= 5 seconds

Telekara

sc=105

sc=106


UE Tx Power in CM+SHO

Active set size=2 Active set size=1

Start of CMEnd of CM

SHO (CM disabled) SHO+CM

Active set size=2 Active set size=1

Start of SHOEnd of SHO


UE Tx Power in CM+SHO: Results

The UE Tx power during CM+SHO was compared with the UE Tx power with SHO only.

The UE Tx power was averaged over 100 meters

In average, the UE transmits 0.6 dBhigher in SHO only than in SHO+CM !?

-17.1

-16.51

-17.2

-17

-16.8

-16.6

-16.4

-16.21

CMNo CM


Downlink Power Control during compressed mode

DL DCH Threshold=-8 dB

First CM starts at DL DCH power=27.5

dBm approx


Inter-System handover delay

Following data were obtained in Espoo NTN network and OPI network (BSIC delay only):

Activation time (from event-trigger to measurement control for RSSI measurements): 0.94s

RSSI delay: 1.13 s

BSIC delay:

Espoo: [6 3 1.5 1.14 1 0.9 1.1] seconds: =>average 2.09 s

OPI network : [2.2 1.73 1.69 2.68] seconds=> average=2 s

Handover message: 200 ms

Total ISHO delay (in the 3G side): = 4.3 s


Contents

Introduction





Decision Algorithm

UE Tx Power (Event 6A)Threshold:GsmUETxPwrThrXXL3 filter:GsmUETxPwrFilterCoeffHysteresis margin:GsmUETxPwrTimeHystData rate threshold

HHOMAxAllowedBitrateUL

UL QualityTimer:ULQualDetRepThresholdData rate threshold

HHOMAxAllowedBitrateUL

DL DPCH powerThreshold:

GsmDLTxPwrThrXXData rate threshold

HHOMAxAllowedBitrateDL

(XX=AMR,CS,NrtPS,RtPS)

CPICH RSCP (Event 1F)Thresholds:HHoRscpThreshold HHoRscpCancelL3 filter: HHoRscpFilterCoefficientTimers:HHoRscpTimeHysteresisHHoRscpCancelTime

CPICH Ec/Io (Event 1F)Thresholds:HHoEcNoThresholdHHoEcNoCancelL3 filter:EcNofilterCoefficientTimers:HHoEcNoTimeHysteresisHHoEcNoCancelTime

AdjgTxPwrMaxTCHAdjgRxLevMinHO (n)GsmMeasAveWindow

GsmMeasRepIntervalGsmNcellSearchPeriodGsmMinMeasIntervalGsmMaxMeasPeriod

Handover Triggering

Handover Execution2G-to-3G back prevention

GsmMinHoInterval

GSM measurement reporting

ISHO Parameters


Measurement triggering: events 1E and 1F

Reporting starts here, 1F

CPICH Ec/No or RSCP

Serving WCDMA

cell HHoRscpThreshold=-105 dBmHHoEcNoThreshold=-12 dB

HHoRscpCancel =-102 dBm HHoEcNoCancel =-9 dB

HHoRscpCancelTime &HHoEcNoCancelTime

1280 ms=default

timeHHoRscpTimeHysteresis=100ms

HHoEcNoTimeHysteresis=100 ms,default 640 ms

No Reporting after this, 1E

RNC

Event is send in RRC: Measurement report message to RNC

HHoRscpFilterCoefficient =200 ms EcNoFilterCoefficient =600 msBefore measurement report is send,Default 200 ms


Reporting Events 6A, 6B and 6D

UE Tx Power less than the threshold =>

reporting stops here, 6B

UE Tx Power greater than the threshold, reporting

starts here, 6A

UE Tx Power

UE Tx Power Threshold,range 11-21 dBm

default max 5 dB

GsmUETxPwrTimeHyst100 ms, default 1280 ms

time

UE is using maxPower, reporting

continues, 6D

UE Tx Power = P_Max = 21 dBm

RNC

Event is send in RRC: Measurement report message to RNC

GSMUETxPwrFilterCoeff=480 msBefore measurement report is sendDefault 200 ms

Serving WCDMA

cell


Filter & Hysteresis Parameters

According to the specifications the accuracy for the Ec/No is 3 times betterthan for the RSCP:

RSCP +-6 dB, Ec/No +-2 dB longer filtering time needed for Ec/No

Optimized set for EcNoFilterCoefficient was found to be 600 ms during SHO measurements

In the CELL_DCH state the measurement period for intra frequencymeasurements is 200 ms

With longer timehysteresis more samples could be get before measurement report is send to RNC:

HHoRscpTimeHysteresis, HHoEcNoTimeHysteresis,GsmUETxPwrTimeHyst 100 ms used due to fast reaction to network to maintain the

connection


DL measurement Threshold &Parameters (AMR) DL_code_PWR -PowerOffsetDLdpcchPilot > CPICH Pwr + MAX_DL_DPCH_TXPWR +

DL_TPCH_TXPWR_Threshold PowerOffsetDLdpcchPilot : 3 dB MAX_DL_DPCH_TXPWR: 2 dB (same parameter than CPICHtoRefRabOffset) DL_TPCH_TXPWR_Threshold for AMR: GSMDLTxPwrThrAMR: -1(-10 dB..0, step 0.5 dB)

HO measurements in case of DL code power -3 dB 33dBm +2dB-1dB

=> DL code Power 37 dBm

BTS Tx Power

Serving WCDMA cell

time

PtxDPCHMaxDefault= 40 dBm

IF measurementsby UE in CM starts here

RNC"Radio Link Measurement report message is send from BTS to RNCBTSor "Dedicated measurementreport" in case of Inter-RNC soft HOfrom drifting RNC to serving RNC


Measurement triggering: UL Quality RNC starts inter-frequency measurements based on outer-loop power control

reports. Outer-loop PC sends a quality deterioration report when the BER/BLER target

has not been reached for RNC: ULQualDetRepThreshold/2 s, 0.5..5, step 0.5s Periodic report, while BLER/BLER target is not reached. Reports from Outer-loop Power Control Controller depends on RNC:

EnableULQualDetRep/1, default 0=no, 1=yes

t

Target SIR

Max SIR target

Min SIR target

Actual SIR target

1st Quality deterioration report from PC to HC inside RNC

2nd Quality deterioration report (if the condition is stillsatisfied the message is periodically repeated)

ULQualDetRepThreshold+ all Target SIR modification command are : SIR >0

Period 5s

This should be on, default off

Faster reporting needed for successful connection-> 2 s


Inter-System measurements

After HO triggering message is sent to RNC, a RRC message Measurement Control is sent to UE containing details of the measurement that the UE must execute

Upon reception of the measurements reported by the UE, RNC applies a sliding averaging window to the RXLEV measurements.

Inter-system measurement stops if RNC has not been able to perform inter-system handover after GSMMaxMeasPeriod (value 10, default =20, 120, step 1 measreport)

RNC could not initiate inter-system measurements if: The UE has recently performed an inter-system HO: GSMMinHoInterval / 10s,

060, step 1s An inter-system HO recently fails for this UE: GSMMinMeasInterval / 10s,

060, step 1s

RNC

RXLEV measurements are reported throughMeasurement report messages

UE

RRC: Measurement report

RRC: Measurement report

The first measurement report has info from the best GSM cell:

BCCH freq & RSSI, no filteringused in UE

No filtering in UE,Periodic reporting, max 6 cells reported,

GsmMeasRepInterval 0.5s



GsmMaxMeasPeriod (default=11s) parameter controls the CM duration time for GSM RSSI&BSIC decoding measurements.

Based on several ISHO tests in the field, the following figures were obtained (GsmNcellSearchPeriod=0):

Average RSSI: 1.13 seconds Average BSIC decoding time: 1.14 seconds (Espoo Network), 2.1

seconds (OPI Network)

Thus, CM maximum duration time seems to be quite long and in some cases does not allow the UE to find select other target cells.

GsmMaxMeasPeriod=6s is currently used in the field.



GsmMinMeasInterval (default=10s) tells the time needed to allow repeat ISHO in case there has been fail.

In case ISHO cancellation event does not occur, and the mobile is leaving clearly the 3G boundary, then there is a death time=16 seconds where the UE is not able to attempt new GSM measurements in case of an unsuccessful ISHO.

Experience in the field has shown us that the probability of the triggering of the cancellation events (event 1B,1E) is very low, thus, it is proposed to reduce the GsmMinMeasInterval to a 2 seconds.

Trigger thresholdCancelation threshold

GSMmeasurements

Unsucessful ISHO6 s 10 s


Inter-System Handover DecisionHo cause example : CPICH RSCP

Decision is based on reported GSM carrier averaged (sliding window) RSSI AVE_RXLEV_NCell(n) > AdjgRxLevMinHO +

Max (0, GSMncellTxPwrMaxTCH - P_max) GSMMeasAveWindow / 6, 132 meas report

Inter-system HO could be forbidden during the first measurements reports from the UE, to let the UE report all the candidate inter-system cells in its neighbourhood.

NcellSearchPeriod / 0, (020 meas report)RSCP, RXLEV

Serving cell,Carrier 1

HHoRSCPThreshold:-105 dBm =>Start of measurements in CM

time

Best neighbour GSMcell, measured as RSSI

AdjgMinRxLevMinHO:>=-102 dBm => Handover

Should happen to good GSM cell


GSM MS starts WCDMA measurements in case running average signal (RLA_C) level is below or above

certain threshold:RLA_C< F(Qsearch_I) for 0


Nokia Strategy :Reselect to good WCDMA cell

t

Serving GSM Cell

Neighbour WCDMA Cell

Ec/NoRSCP/RLA_C

5 sec.

FDD_Qmin=7(-13 dB)

Minimum Quality Requirement for WCDMA reselection (Fdd_Qmin)

Ec/N0

RSCP

Cell Reselection to WCMDA

Qsearch_I=7 (measure always

WCDMA cell)FDD_Qoffset =0 dB

(Reselect to WCDMA in case CPICH EC/No > -13 dB)


Cell reselection to GSM First ranking of all the cells based on

CPICH RSCP (WCDMA) and RSSI (GSM)

Rs = CPICH RSCP (WCDMA) + Qhyst1or Rs = RSSI (GSM) + Qhyst1

Rn=CPICH_RSCP(n) or RXLEV(n)-Qoffset1

Rn higher in GSM cellYes No

Cell re-selection to GSM Second ranking only for WCDMA cells based

On CPICH Ec/No

Rs = CPICH Ec/No + Qhyst2Rn=CPICH_Ec/No(n)-Qoffset2

Cell re-selection to WCDMA cell of highest

R value

In First Ranking the strongest GSM or WCDMA cell is found

In Second Ranking the best WCDMA cell (CPICH Ec/No) is

found

Neighbour cellcalculation with offset

parameter

Serving cell calculation with hysteresis parameter

GSM cell measurementsavailable If :

CPICH Ec/No-QqualMin < Ssearch_RAT


Key Parameters for GSM reselection

Ssearch_RAT (default value= 0 dB) & Qqualmin (default value=-20 dB) At a CPICH EcNo =Qqualmin-Ssearch_RAT or lower, the terminal will start

measuring the GSM cells. With default values, the terminal is ordered to camp on 3G at CPICH EcNo levels above -20 dB.

Ssearch _RAT should be set such that with the CPICH Ec/No of -13 dB or lower GSM measurements should start.

To have reasonable good quality but also easy cell access selection the Qqualmin could be set higher value = -17 dB

=> Ssearch_RAT would need to be 2 (4dB) to give a theshold at -13 dB.

Qhyst1 (default value= 4 dB) Since the Ssearch_RAT will be optimized to start the GSM measurements

at the lowest possible CPICH EcNo level, the difference between the 3G serving cell and GSM neighbour cell should be low enough (e.g. between 0 and 3 dB) so that the terminal can move to the GSM cell quickly.


Nokia Strategy: reselect to GSM early HCS not yet supported by NMP UE

Qmeas (CPICH Ec/No)

t

Serving WCDMA Cell

Neighbour GSM Cell

Qhyst1=4 dB

AdjgQoffset1=0 dB

SsearchRAT= 2 (4 dB)

Rs

Qqualmin= -17 dB

Squals

GSM Measurements starts when Squal= CPICH Ec/No-Qqualmin

< SsearchRAT:CPICH Ec/No< -14 dB

Cell re-selectionTo GSM

Rs


How to avoid 3G2G ping pong

When phone is camped on 3G, GSM measurements can start when CPICH Ec/Io of serving cell is below Ssearch_RAT + QqualMin.

When phone is camped on GSM, cell reselection to 3G is possible if CPICH Ec/Io of the candidate is above FDD_Qmin.

Therefore, to avoid ping pongs between 3G and GSM the following condition should be met:

FDD_Qmin >= QqualMin+Ssearch_RAT

QqualMin=-17 dB

Ssearch_RAT=4 dB

CPICH Ec/Io

FDD_Qmin >= -13 dB

QqualMin +Ssearch_RAT

t

Camping on 3G Camping on GSM Camping on 3G


Contents

Introduction





ISHO step 1/19: Network Signalling (Iub and Iu-CS DL/UL)Ue NodeB RNC

RRC: Measurement Control (CPICH Ec/No & CPICH RSCP indication TRUE)

RRC: Measurement Report (event 1F)

NBAP: Radio Link Reconfiguration Prepare

NBAP: Radio Link Reconfiguration Ready

NBAP: Radio Link Reconfiguration Commit

RRC: Physical Channel Reconfiguration

RRC: Physical Channel Reconfiguration Complete

NBAP: Compressed Mode Command (CFN, TGPSI2)

RRC: Measurement Control (GSM RSSI, CFN, TGPSI2)

RRC: Measurement Report (GSM RSSI, BCCH ARFCN)

RRC: Measurement Control (BSIC, CFN, TGPSI3)

RRC: Measurement Report (BSIC, GSM Cell index)

NBAP: Compressed Mode Command (CFN, TGPSI3)

RANAP: Reloc.Req.

RANAP: Reloc.Com.RRC: Handover from UTRAN Command

MGW


ISHO step 2/19:RRC: Measurement Control(DL)


ISHO step 3/19:RRC: Measurement Report(UL)


ISHO step 4/19: NBAP: Radio Link Reconfiguration

Prepare (DL)


ISHO step 5/19: NBAP: Radio Link Reconfiguration Ready/Commit (UL/DL)


ISHO step 6/19: RRC: Physical

Channel Reconfiguration

(DL)


ISHO step 7/19: RRC: Physical Channel Reconfiguration Complete (UL)


ISHO step 8/19: NBAP: Compressed

Mode Command (CFN, TGPSI2, DL)


ISHO step 9/19: RRC: Measurement Control (GSM RSSI, CFN, TGPSI2, DL)


ISHO step 10/19: RRC: Measurement Report (GSM RSSI, BCCH ARFCN, UL)


ISHO step 11/19: NBAP: Compressed Mode

Command (CFN, TGPSI3, DL)


ISHO step 12/19: RRC: Measurement

Control (BSIC, CFN, TGPSI3, DL)


ISHO step 13/19: RRC: Measurement Report (verified BSIC, UL)


ISHO step 14/19: handover requiredand handover command in A i/f


ISHO step15/19:

handover request in A i/f


ISHO step 16/19: handover command in A i/f


ISHO step 17/19: RRC: handover from UTRAN command (DL)


ISHO step 18/19: ch. act., ho detect and ho complete in Abis i/f


ISHO step 19/19: handover detect and handover complete in

A i/f

118939337 isho training

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