60523609 NSN 2G 3G Parameter Setting

8/10/2019 60523609 NSN 2G 3G Parameter Setting

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1 NSN Siemens Networks Presentation / Author / Date

I insert classification level

Sharing Traffic 2G-3G

Load Base Handover 2G-3GCell Reselection

3G-2G

2G-3G

PUSH AMR


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Soc Classification level

Load based Handover GSM -> WCDMA

100%

80%

0%

Load reasonHandoversfor speech

Load of GSM cell

Packet Data to WCDMAregardless of GSM load

Speech to WCDMAonly with high GSM load

Higher bit ratesfor data users

More capacityfor speech

Packet BCCH parameters can be usedto push GPRS mobiles to WCDMA

Utran

HoThScTpdc

= 80%


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GSM

GSM

Load & Coverage Reason Handover

GSM

GSM highloaded

WCDMA lowloaded

GSM GSM

WCDMA WCDMA

Load reasonHandover for speech

and for HSCSD

WCDMA GSM

Load reasonHandover

Coverage reasonHandover

WCDMA can be usedto relieve GSM overload

GSM can be used to extendWCDMA coverage area

Mobile moving


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Load based Handover Process: GSM-> WCDMA

Handover Triggering Thresholds set in BSC

Inter-RAT measurements starts in caseThe RXLEVof the serving cell is above orbelow the given threshold Qsearch_C

Handover Decisionis done in case of

Load of the serving cell > Load_Threshold

& CPICH Ec/No> min Ec/No Threshold

MS selects the target UTRAN cell based

on measurement results

Handover command is send to MSC

MS is measuring the UTRAN cells continuouslyif they are defined as a neighbor ,

The number of GSM neighbor reported could be 3-6depending on the set value of parameterFDD_MULTIRAT_REPORT(0,1,2=def,3).

The load is measured in the cell level by comparing

the occupied TCHs to the available TCHs (20 s

interval used)

Load Threshold for Speech Calls or Transparent Data

inter-RAT Handover:

utranHoThScTpdc(Min Traffic Load TDHO),default = 80%

minEcnoThreshold(Min CPICH EC/NO

Threshold), default15 dB

Parameters are sent from the BSC to the mobilein the Measurement Information message


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ISHO 2G -> 3G Parameters

Parameter Specification name NSN parameter Range Default value

min traffic load for speech call LOAD_THRESHOLD_FOR

_SC_IS_HO

utranHoThScTpdc (LTSC) 0-100% 80%

minimum CPICH Ec/Io level MIN_ECNO_THRESHOLD minEcnoThreshold

(MET)

-240.5 dB -15 dB

min interval between unsucc ISHO

attempt

MIN_INTERVAL_BETWEE

N_UNSUCC_ISHO_ATTE

MPT

minIntUnsuccIsHo (UMIU) 0255 s 3 s

threshold for multi-RAT MS Qsearch_C qSearchC (QSRC) 015 15 (never)

rec. 7 (always)

Specification name Parameter explanation Value range Note

FDD_REP_QUANT Indicates the reporting quantity for UTRAN

FDD cells

0=RSCP,

1=EC/NO

Not tunable,

Fixed value 1

3G_SEARCH_PRIO Indicates if 3G cells may be searched when

BSIC decoding is required

0 = no,

1 = yes

Not tunable,

Fixed value 1

FDD_MULTIRAT_REPORTING The number of cells from the access

technology/mode FDD that shall be includedin the measurement report

03 Not tunable,

Fixed value 2

Qsearch_C_Initial Indicates the Qsearch value to be used in

connected mode before Qsearch_C is

received

0 = use Qsearch_I,

1 = (always)

Not tunable,

Fixed value 0

Changeable

Hidden




Handover Control

GSM ISHO

Load Based Handover to WCDMA Cell Reselection




Cell Reselection 3G -> 2G

First ranking of all the cells based onCPICH RSCP (WCDMA) and RSSI (GSM)

Rs = CPICH RSCP + Qhyst1Rn= Rxlev(n) - Qoffset1

Rn (GSM) > Rs (WCDMA)And

Rxlev (GSM) >QrxlevMin

YesNo

Cell re-selectionto GSM

Neighbour WCDMA or GSM

cell calculation with offsetparameter

Serving WCDMA cellcalculation, with

hysteresis parameter

UE starts GSM measurements ifCPICH Ec/No < qQualMin+ sSearchRAT

SintraSearch

SinterSearch

SsearchRAT

CPICH EcNo

qQualMin

Second ranking only for WCDMAcells based on CPICH Ec/No

Rs = CPICH Ec/No + Qhyst2Rn=CPICH_Ec/No(n)-Qoffset2 Cell re-selection to

WCDMA cell of highestR value


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Cell Reselection 3G -> 2G

UE ranks the serving cell and the measured neighboring cells to find out if

reselection should be madeAll the measured suitable cells (S-criteria) are included in the ranking.

Criteria for a suitable cell (S-criteria) is defined as

WCDMA intra-frequency neighbor cell:

CPICH Ec/No > AdjsQqualminand CPICH RSCP > AdjsQrexlevmin

WCDMA inter-frequency cell:

CPICH Ec/No > Adj iQqualminandCPICH RSCP > Adj iQrexlevmin

GSM cell:

Rxlev > Qrxlevmin

Ranking is done using Criteria R, and the UE reselects to the cell with highest R-

criteria. R-criteria is defined as:

For serving cell: Rs = Qmeas,s+ QhystsFor neighboring cell Rn = Qmeas,nQoffsetts,n

Qmeas is CPICH Ec/No for WCDMA cell and RxLev for GSM cell

GSM measurements can start when CPICH Ec/Io of serving cell is below Ssearch_RAT+ QqualMin


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GSM MS starts WCDMA measurements if:RLA_C< F(Qsearch_I) for 0


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Cell Re-selection Parameters

Qsearch_Iand Qsearch_Pdefine the threshold for non-GPRS/GPRS (respectively) capable

UEs to measure 3G neighbour cells when a running average of the received downlink

signal level (RLA_C) of the serving cell is below (0-7) or above (8-15) the threshold

Value 0 1 6 7 8 9 10 14 15

dBm -98 -94 -74 Always

-78 -74 -70 -54 Never

FDD_QoffsetandFDD_GPRS_Offsetthe non-GPRS/GPRS (respectively) capable UEsadd this offset to the RLA_C of the GSM cells. After that the UE compares the

measured RSCP values of 3G cells with signal levels of the GSM cells

Value 0 1 2 3 8 14 15

dBm -always -28 -24 -20 0 24 28

Always selectirrespective of RSCPvalue

Reselect in case RSCP >GSM RXLev (RLA_C)+28dB

If RLA_C < -94 UE starts3G measurements

UE always measures 3Gcells

If RLA_C > -70 UE starts3G measurements


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RLA_C

Cell Re-selection Example: weaker WCDMANon GPRS case

t

Serving GSM Cell

Neighbour WCDMA Cell

Ec/NoRSCP/RLA_C

5 sec.

Cell re-selection to WCDMA

FDD_Qmin=0-12 dB

FDD_Qoffset= -8 dB

Qsearch_I =-98 dBm

Measurements starts (serving cell)

Minimum Quality Requirement for WCDMA

Ec/N0

RSCP

GSM -> WCDMA

CPICH RSCP> RLA_C+ FDD_Qoffset&

CPICH Ec/No FDD_Qmin

Idle Mode


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Cell Re-selection Example: stronger WCDMAGPRS case

t

Serving GSM Cell (Best)

Neighbour WCDMA Cell

Ec/NoRSCP/RLA_C

5 sec.

Cell re-selection to WCDMA

FDD_Qmin= -20 dB

FDD_GPRS_Qoffset= 8 dB Qsearch_P

= -98 dBm

RLA_P

Measurements starts (serving cell)

Minimum Quality Requirement for WCDMA

Ec/N0

RSCP

Connected Mode

GSM -> WCDMA


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How to avoid 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=-18 dB

Ssearch_RAT=4 dB

CPICH Ec/Io

FDD_Qmin >= -12dB

QqualMin +Ssearch_RAT

t

Camping on 3G Camping on GSM Camping on 3G


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PUSH AMR

Push Voice 3G-2G


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max. al lowed UE Tx Power(e.g. 21 dBm)+

GsmUETxPwrThrAMR:

FMCG; -60..0; 1; -3 dBhere: - 60 dB !

Forced Handover for AMR Voice Call

Feature can be used to push3G AMR calls to 2G

Extreme parameter setting for ISHO

trigger cause UE Tx power (event 6A)

WCDMA

GSM

AMR voice call setup in 3G

forced handover

to GSM

[..]UE RNC

RRC: RadioBearerSetup

RRC: RadioBearerSetupComplete

RRC: MeasurementControl

RRC: MeasurementReport (event 6A)

FMCG: GSMcauseTxPwrUL

FMCG: GsmUETxPwrThrAMR

ISHO measurements & HO

to GSM

UE immediately answers

with Measurement Report

push means Handover, not Directed-Retry !

Remember:

6A:UE Tx power >

absolute threshold

GSMcauseTxPWRUL FMCG; 0 (no) /1 (yes)


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THANKS

60523609 NSN 2G 3G Parameter Setting

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