850_1900 Balance

8/10/2019 850_1900 Balance

1/23

1

850 and 1850

carriers load balance

19/04/2013

8/10/2019 850_1900 Balance

2/23

/

UMTS 850 band deployment

At the beginning of WCDMA 850 deployment, the reason is typically

coverage expansion for rural areas rather than traffic balancing.

UMTS 850 band can also serve as capacity expansion layer covering

same area than UMTS 1900 carrier

1. Bigger cell radius of UMTS 850 band could bring some challenges for the

Cell reselection & handover parameter planning2. Possibilities to balance load between the Bands are limited, especially if we

want to balance HSPA load between the bands

2+2+2 UMTS1900

UMTS1900

UMTS1900

UMTS1900

UMTS1900

UMTS850

2+2+2 UMTS1900 +1+1+1 UMTS850

CapacityUpgrade

2+2+2 UMTS1900

UMTS1900

UMTS1900

UMTS1900

UMTS1900

UMTS850

2+2+2 UMTS1900 +1+1+1 UMTS850

CapacityUpgrade

8/10/2019 850_1900 Balance

3/23

8/10/2019 850_1900 Balance

4/23

Cell Reselection

Cell reselection parameter and features are applicable for UEs in RRC

idle and RRC connected mode states CELL_FACH, CELL_PCH and

URA_PCH

UE is responsible of the evaluation the quality of the serving cell and the

neighbor cells and for performing a cell re-selection procedure if

needed. From RU10 onwards it is possible to use different parameters for cell

selection and reselection in idle mode (SIB3) and in connected mode

(SIB4)

Idle mode UEs used RT HOPI parameter set (send in SIB11). NRT

HOPI is used for UEs in connected mode CELL_FACH or CELL_PCH(sent in SIB12)

8/10/2019 850_1900 Balance

5/23

Inter-frequency Cell reselection

Inter-frequency neighbour cells have to be measured by the UE

only when equation below for serving cell is fulfilled.

By default, this means that Inter-frequency measurement will start when

Ec/Io drops below -10 dB (Sintersearch = 8dB / Qqualmin = -18 dB).

chSintersearSqualcriteriatmeasuremenfrequencyInter :

8/10/2019 850_1900 Balance

6/23

/

Inter-frequency Cell reselection

Cell fulfilling S-criteria (including serving and neighbour cells) are ranked

according to R-criteria. From RU10 onwards CPICH RSCP can be used as alternative for CPICHEcNo as as intra- and inter-system cell reselection criterion by usingCellSelQualMeasparameter

The configuration of the RCSP threshold for inter-frequency measurementcriteria and ranking should be considered in areas with high HSDPA activityin order to prevent ping-pong effect between layers.

R-criteria formula for EcNo

R-criteria formula for RSCP

By Using negative AdjiQoffset2 (e.g. -50 dBm) in RT HOPI we can ForceUEs to certain layer

2:cellsNeighbor

2:cellServing:

,

,

QoffsetEcNoR

QhystEcNoREcNocriteriaR

nmeasn

smeass

11:

,

,

QoffsetRSCPRQhystRSCPRRSCPcriteriaR

nmeasn

smeass

8/10/2019 850_1900 Balance

7/23/

Cell reselection without HCS

CPICH Ec/No

CPICH RSCPCPICH Ec/No

CPICH RSCP

QqualMin = -20dB

Time

CellReselection

UE changes the serving cell to

cell A from Cell B.

UE starts neighbor cell

measurements near cell edge.

Neighbour requirement =

4dB (Qhyst2)

5 seconds

(Treselection)

QqualMin +Sintersearch

=- 18 dB + 8 dB = -10dB

8/10/2019 850_1900 Balance

8/23/

Inter-frequency HO triggers

Following Coverage and Quality reason Inter-frequency HO triggering methods can

be used (Similar triggering methods available also for ISHO) Coverage Based ISHO Handovers should be triggered if IFHO fails

1. Low measured absolute CPICH Ec/No FMCI: IFHOcauseCPICHEcNo

FMCG: GSMcauseCPICHEcNo)

2. Low measured absolute CPICH RSCP

FMCI: IFHOcauseCPICHrscp FMCG: GSMcauseCPICHrscp

3. UE Tx Power approached its maximum allowed Power FMCI: IFHOcauseTxPwrUL

FMCG: GSMcauseTxPwrUL

4. DL DPCH approaches its maximum allowed power

FMCI: IFHOcauseTxPwrDL

FMCG: GSMcauseTxPwrDL5. Quality deterioration report from UL outer loop PC

FMCI: IFHOcauseUplinkQuality

FMCG: GSMcauseUplinkQuality

8/10/2019 850_1900 Balance

9/23

Decision Algorithm

UE Tx Power (Event 6A\6B)

Threshold:

InterFreqUETxPwrThrXXL3 filter:InterFreqUETxPwrFilterCoeff *Hysteresis margin (time to trigger):

InterFreqUETxPwrTimeHyst *Data rate threshold

HHOMAxAllowedBitrateUL *

UL Quality

Timer:

ULQualDetRepThreshold

Data rate threshold

HHOMAxAllowedBitrateUL

DL DPCH power

Threshold:InterFreqDLTxPwrThrXXData rate threshold

HHOMAxAllowedBitrateDL

(XX=AMR,NrtPS,RtPS)

CPICH RSCP (Event 1F)

Thresholds:

HHoRscpThresholdHHoRscpCancelL3 filter:

HHoRscpFilterCoefficient *Time to trigger:

HHoRscpTimeHysteresis *

HHoRscpCancelTime *

CPICH Ec/Io (Event 1F)

Thresholds:

HHoEcNoThresholdHHoEcNoCancelL3 filter:

EcNoFilterCoefficient *Time to trigger:

HHoEcNoTimeHysteresis *

HHoEcNoCancelTime *

Adj iP lossMargin

Adj iMinEcNo

AdjiMinRSCP

AdjiTxPwrDPCH

Adj iEcNoMargin

InterFreqMaxMeasPeriodInterFreqMeasRepInterval

InterFreqNcellSearchPeriod

InterFreqMinHoInterval

InterFreqMinMeasInterval

InterFreqMeasAveWindowHandover Triggering

Handover Execution

IF HO meas control parameters

IFHO Parameters

8/10/2019 850_1900 Balance

10/23

IFHO decisionQuality CriteriaHO trigger either DL DPCH or CPICH EcNo

a) AVE_RSCP_NCELL (n) >AdjiMinRSCP(n)+ max(0,AdjiTxPwrDPCH(n)P_MAX)

b) AVE_EcNo_NCELL (n) > AVE_CPICH_EcNo +AdjiEcNoMargin(n)

AdjiMinRSCP(n)

max(0,AdjiTxPwrDPCH(n) - P_MAX)

b)

AdjiMinEcNo(n)

AdjiEcNoMargin(n)

AVE_EcNo_NCELL (n)

a)

AVE_EcNo_NCELL(n)>AVE_CPICH_EcNo+ AdjiEcNoMargin(n)

8/10/2019 850_1900 Balance

11/23

IFHO decisionPath loss CriteriaHO trigger either UE Tx Power, CPICH RSCP or UL DPCH

a) AVE_EcNo_NCELL(n)>AdjiMinEcNo(n)

b) CPICH_POWER - AVE_CPICH_RSCP

> CPICH_POWER_NCELL(n)- AVE_RSCP_NCELL(n) +AdjiPlossMargin(n)

best active set

cell

AdjiPlossMargin(n)

best inter-frequency cell

b)AVE_EcNo_NCELL (n) > AdjiMinEcNo(n)

AdjiMinEcNo(n)

a)

8/10/2019 850_1900 Balance

12/23

Multi Band Load Balance

NSN RAN has several layering features that can be used to balance

HSDPA load between carriers.

1. UMTS carriers in same band, having same coverage area and configured under common sector

id

Directed RRC Connection Setup features.

HSPA layering for UEs in Common Channel.

Multi-band Load BalancingMBLB HSDPA load balancing is included to MBLB Blind HO and MBLB state transition features.

Balances also other traffic to certain extent with some assumptions.

2. UMTS carriers in different band, having different coverage areas or BTSs

Multi Band Load BalancingMBLB

HSDPA load balancing is included to MBLB Blind HO and MBLB state transition

features. Balances also other traffic to certain extent with some assumptions.

Additionally idle mode settings & different type of IFHO can be used move UEs between

bands/carriers, but HSDPA load balancing between carriers is done either with DRRC or

MBLB.

8/10/2019 850_1900 Balance

13/23

MBLB Blind HO and MBLB State Transition -

Activation

Blind IFHO in RAB Setup Phase is activated with parameter MBLBRABSetupEnabled(WCEL)

Blind IFHO to the target cell in the preferred carrier or band is triggered during RAB

setup phase

1. First RAB setup is done for the UE (UE coming from idle).

2. AMR RAB Setup for multirab case is done for the UE. I.e. UE is already in connected mode,

see MBLBRABSetupMultiRAB (WCEL).

3. Feature requires Adji definitions

MBLB Layering in State transition Phase is activated with parameter

MBLBStateTransEnabled (WCEL)

Layering in state transition the target cell in the preferred carrier or band is triggered

during State transition

1. State transitions from CELL_FACH, URA_PCH or CELL_PCH

2. Does not include transition from RRC Idle mode

3. Feature requires Adji definitions

8/10/2019 850_1900 Balance

14/23

MBLB Blind HO and MBLB State Transition -

Activation

MBLB requires that Intra frequency RACH measurements quantity hasbeen changed from EcNo to RSCP with parameter

RACHIntraFreqMesQuant (WCEL)

1. This will impact other featuresfirst trials show no negative impact

HSUPA 2ms TTI, SRB on HSPA, Common Channel Setup and Fast Call setup

from Cell_PCH

With MBLB Inter-frequency measurement are added for RACH

1. Target cell measurements can be used instead of totally blind HO for Rel6

or Newer UEs. (optional UE feature, penetration?)

8/10/2019 850_1900 Balance

15/23

MBLB Blind HO and MBLB State Transition

Target Cell selection

Target cell for MBLB Blind HO and MBLB State Transitioncan be any Intra-RNC

Inter- frequency neighbor cell which is not in load state. Target cell can be withinsame or different BTS/within same or different UMTS bands.

Possible target cells for MBLB can be identifiedwith two complementary methods.

Based on source cellmeasurements:

Possible target cell is defined withBlindHOTargetCell (ADJI)parameter. Only onetarget cell per frequency can be defined.

Based on target cellmeasurements:

Cell is possible target cell for blind HO if the cellwas included in inter-frequency measurementresults on RACH (even though blind HO to thatcell is not enabled from source cell withBlindHOTargetCellparameter) and is from sameRNC than source cell.

BlindHOTargetCell

8/10/2019 850_1900 Balance

16/23

MBLB Blind HO and MBLB State Transition

Counters

MBLB Blind HO performance Counters

With/without measurement means whether the UEhad reported inter-frequency cell measurement

results on RACH.

Not all the UEs are supporting inter-frequency

measurements

Counter ID Counter Name

M1006C234 RB Setup Attempt with BLIND HO

M1006C235 RB SETUP SUCCESSFUL WITH BLIND HO

M1006C236 RB SETUP FAIL BLIND HO DUE TO UE NACK WITHOUT

MEAS

M1006C237 RB SETUP FAIL BLIND HO DUE TO UE NACK WITH MEAS

M1006C238 RB SETUP FAIL BLIND HO DUE TO UE LOST WITHOUTMEAS

M1006C239 RB SETUP FAIL BLIND HO DUE TO UE LOST WITH MEAS

MBLB Layering Performance Counters Counters below are incremented when the UE is in

URA_PCH/ Cell_PCH/ Cell_FACH state, and thereis state transition attempt/success/failure intoCELL_DCH state under another BTS

Counter ID Counter Name

M1006C240 ATTEMPTED INTER-BTS LAYER CHANGES IN PCH/FACH

TO DCH

M1006C241 SUCCESSFUL INTER-BTS LAYER CHANGES IN PCH/FACH

TO DCH

M1006C242 FAILED INTER-BTS LAYER CHANGES IN PCH/FACH TO

DCH

8/10/2019 850_1900 Balance

17/23

The decision making for MBLB activities is based on preference score calculation for

each Wcell participating MBLB activity. Preference score calculation includes 4 components

Preferred frequency Layer weight and Load Weight is enabled (load cannot be

enabled alone)

1. With Preferred frequency it is defined which services are included in

load balancing.

2. Band Weight is not used as it is assumed that there is enough UEs in

the market supporting both bands.

3. RSCP weight is not used

MBLB Preference Score calculation

Introduction

Preference

Score =

LaySelWeightPrefLayer

or 0

LaySelWeightBand

or 0

LaySelWeightRSCP

or 0>=LaySelWeightLoad

or 0

Not considered

for fast moving

UEs

Not considered

for non-HSPA

UEs or other with

CS RAB in DCH

cell

Preferred

Freq weight

Freq Band

weightRSCP

WeightLoad

Weight

+++

Only for Blind

HO and layer in

state transitions

8/10/2019 850_1900 Balance

18/23

Preferred Frequency Layer

UE capability and Service

PrefLayerWeight value is set based on UE capability and service type (e.g. HSDPA

UE with NRT service) Preferred layers for UE capability and service combination are checked from PFL-

PrefLayerparameters. If the frequency layer is preferred for the UE, PrefLayerWeight is set

to value taken from LaySelWeightPrefLayer (PFL) Parameter. If the frequency layer is not

preferred for the UE, PrefLayerWeight is set to value 0.

UE capability & Service Combination define correct parameter.

UE capabilities has following priority order. For one UE capability and service combination, up toeight preferred layers can be defined. The one selected is affected by other definitions

UE Capability Priority Order Service parameters included to PFL object

CS Voice Over HSPA PrefLayerCSHSNRT PrefLayerCSHSStr PrefLayerCSHSAMR PrefLayerCSHSAMR&NRT

DC HSUPA ? PrefLayerDCHSUNRT PrefLayerDCHSUStr PrefLayerDCHSUAMR PrefLayerDCHSUAMRNRT

DC HSDPA + MIMO PrefLayerDCMINRT PrefLayerDCMIStr PrefLayerDCMIAMR PrefLayerDCMIAMR&NRT

DB-DC-HSDPA ? PrefLayerDBDCHSDPANRT PrefLayerDBDCHSDPAStr PrefLayerDBDCHSDPAAMR PrefLayerDBDCHSDPAAMR&NRT

DC HSDPA * PrefLayerDCHSDNRT PrefLayerDCHSDStr PrefLayerDCHSDAMR PrefLayerDCHSDAMR&NRT

MIMO** PrefLayerMIMONRT PrefLayerMIMOStr PrefLayerMIMOAMR PrefLayerMIMOAMR&NRT

HSDPA 64QAM PrefLayer64QAMNRT PrefLayer64QAMStr PrefLayer64QAMAMR PrefLayer64QAMAMR&NRT

F-DPCH PrefLayerFDPCHNRT PrefLayerFDPCHStr PrefLayerFDPCHAMR PrefLayerFDPCHAMR&NRT

HSPA PrefLayerHSPANRT PrefLayerHSPAStr PrefLayerHSPAAMR PrefLayerHSPAAMR&NRT

HSDPA PrefLayerHSDPANRT PrefLayerHSDPAStr PrefLayerHSDPAAMR PrefLayerHSDPAAMR&NRT

R99 PrefLayerR99NRT PrefLayerR99Str PrefLayerR99AMR PrefLayerR99AMR&NRT

UEselectfirstde

finedthat

machitscap

ability

8/10/2019 850_1900 Balance

19/23

PFL ConfigurationParameter Object Default Value Value

PFLIdentifier PFL - 1

AMRToNonPreferredLayer PFL disabled (0)

BlindHORSCPThrAbove PFL 0 dBm -

BlindHORSCPThrBelow PFL -126 dBm -

LaySelLowLoadPref PFL disabled (0) Enabled

LaySelWeightBand PFL 0 0

LaySelWeightLoad PFL 0 1000

LaySelWeightPrefLayer PFL 1000 10

LaySelWeightRSCP PFL 0 0

PrefLayer64QAMAMR PFL 0

PrefLayer64QAMAMRNRT PFL 0

PrefLayer64QAMNRT PFL 0

PrefLayer64QAMStr PFL 0

PrefLayerCSHSAMR PFL 0

PrefLayerCSHSAMRNRT PFL 0

PrefLayerCSHSNRT PFL 0

PrefLayerCSHSStr PFL 0

PrefLayerDCHSDAMR PFL 0

PrefLayerDCHSDAMRNRT PFL 0

PrefLayerDCHSDNRT PFL 0

PrefLayerDCHSDStr PFL 0

PrefLayerDCMIAMR PFL 0

PrefLayerDCMIAMRNRT PFL 0

PrefLayerDCMINRT PFL 0

PrefLayerDCMIStr PFL 0

Parameter Object Default Value Value

PrefLayerFDPCHAMR PFL 0

PrefLayerFDPCHAMRNRT PFL 0

PrefLayerFDPCHNRT PFL 0

PrefLayerFDPCHStr PFL 0

PrefLayerFastMovUECS PFL 0

PrefLayerFastMovUEPS PFL 0PrefLayerHSDPAAMR PFL 0 F1/F2

PrefLayerHSDPAAMRNRT PFL 0 F1/F2

PrefLayerHSDPANRT PFL 0 F1/F2

PrefLayerHSDPAStr PFL 0

PrefLayerHSPAAMR PFL 0

PrefLayerHSPAAMRNRT PFL 0

PrefLayerHSPART PFL 0

PrefLayerHSPAStr PFL 0PrefLayerMIMOAMR PFL 0

PrefLayerMIMOAMRNRT PFL 0

PrefLayerMIMONRT PFL 0

PrefLayerMIMOStr PFL 0

PrefLayerR99AMR PFL 0

PrefLayerR99AMRNRT PFL 0

PrefLayerR99NRT PFL 0

PrefLayerR99Str PFL 0

Using PFL objectPreferred layers for each UE capability

and service combination can be defined.

UEs have priority order, HSPA capable UE is always

also HSDPA capable UE. If HSPA not defined UE goes

down until it finds next priority (HSDPA) and should follow

those definitions. (Claro: keep it simple, All service, all

layers.)

8/10/2019 850_1900 Balance

20/23

HSPA Load

HSPA load information is used for

HSDPA load balancingSelecting less loaded frequency layer when it is suitable

HSPA overload handlingtry to direct UEs away from loaded cell and not to select

loaded cell to target for any layering activities

Different load is used forLoad balanc ing and for Load state.

Load balancing

1. HSDPA power per NRT users & DL used powerLoad State

1. If any of the following indicates Loaded state, the HSPA load level in the cell is

set to HSPA Load state

2. DL used power & average HSDPA provided bit rate for NRT users

3. UL receiver noise & average E-DCH provided bit rate for NRT users

4. Max number of HSDPA users

5. HSUPA resource status

8/10/2019 850_1900 Balance

21/23

PRIFILE 002:1897 RN60_MAINT_22 1/2

Following source cell measurement results can be available for blind HO:

1. UE measures and reports RSCP value from current cell and best neighbor cell to RNC inRRC Connection Request and Cell Update messages.

1. IF best neighbor is having better RSCP than current cell it will use best

neighbor instead

2. This is causing problems due the inaccuracy of best neighbor measurement

results as in some cases too good compared to reality

3. PRFILE 002:1897 RN60_MAINT_22 can be used to disable the use ofmonitored cell (intra-frequency neighbor cell) in RACH measurement results.

This means that Blind HO can be triggered only from the current cell and the

current cells RSCP value is used when defining the initial power for Blind HO

2. UE also reports RSCP values within event 1a and even 1c Measurement Report

messages for soft handover radio link addition/replacement

3. The UE also provides periodic RSCP reports if the SRB is mapped to HSPA For Blind HO latest available measurement report containing RSCP value of Source cell

is used.

Source cell for Blind HO in RAB setup phase is the cell which has reported highest

RSCP value in latest measurement report

PRIFILE 002:1897 RN60 MAINT 22 2/2

8/10/2019 850_1900 Balance

22/23

PRIFILE 002:1897 RN60_MAINT_22 2/2

Performance before and after PRIFILE activation

PS NPO CC / Nov 2012

8/10/2019 850_1900 Balance

23/23

Muchas Gracias.

Celcite Proprietary & Confidential 23