06 3G and HSDPA Important Parameters

1. RAN_Parameter Configuration1. RAN_Parameter Configuration2. Main RAN_Parameter Grouping based on Functionality2. Main RAN_Parameter Grouping based on Functionality3. Specific HSDPA Parameter3. Specific HSDPA Parameter

HSDPA and RAN ParametersHSDPA and RAN ParametersTelkomsel Jabotabek 3G NetworkTelkomsel Jabotabek 3G Network

Company Confidential2 © Nokia Siemens Networks

RAN_Parameter Configuration


Logical Structure of the RNC Database Objects

RNC

WBTS

WCELADJS

HOPS

ADJG

HOPG

FMCG

ADJI

HOPI

FMCI

FMCS

COCO

WANE

WSG

WLCSE

WSMLC


Managed Object types

• RNC = Radio Network Controller

• WBTS = WCDMA Base Station

• WCEL = WCDMA Cell

• ADJ = Adjacency for WCDMA cell

• ADJS = intra-frequency adjacency

• ADJI = inter-frequency adjacency

• ADJG = inter-system adjacency

• HOP = Handover Path

• HOPS, HOPI, HOPG

• FMC = Frequency Measurement Control

FMCS, FMCI, FMCG

• COCO = Radio Network Connection Configuration

• WANE = WCDMA Authorized Network

• WSG = WCDMA subscriber group

• WLCSE = WCDMA Location service entity

• WSMLC = WCDMA Serving Mobile Location Center


Parameter Count

Ref: RAN05 (RN2.1) parameter dictionary

Parameter count GroupMO Class AC HC Ident LC PC PS SI Other Grand TotalADJG 14 1 1 16ADJI 16 1 1 18ADJS 17 1 1 19COCO 2 82 84FMCG 22 1 9 32FMCI 22 1 9 32FMCS 21 1 9 31HOPG 8 1 9 18HOPI 15 1 9 25HOPS 16 1 9 26RNC 53 8 30 1 16 51 26 96 281WANE 8 9 17WBTS 9 5 2 6 19 21 62WCEL 27 13 12 12 17 23 45 53 202WLCSE 6 34 40WSG 8 9 17WSMLC 1 12 13Grand Total 89 193 62 19 33 93 71 373 933


Main RAN_Parameter Grouping based on Functionality


Main RAN_Parameter Grouping

• Idle Mode: Cell Selection/ Re-selection

• RRC Connection Establishment

• RAB Establishment

• Handovers


• WCEL: QrxlevMin (-115 dBm)•The minimum required RX level in the cell. •This parameter is part of SIB 3.•[-115 ... –25] dBm, step 2 dBm; default: -115 dBm.

• WCEL: QqualMin (-18 dB)•The minimum required quality level in the cell (Ec/No). •This parameter is part of SIB 3.•[-24 ... 0] dB, step 1 dB, default: -18 dB.

• WCEL: UEtxPowerMaxPRACH (21 dBm)•This parameter defines the maximum transmission power level a UE can use on PRACH. •The value of the parameter also effects the cell selection and reselection procedures. •The value of the parameter is sent to UE in the Cell selection and re-selection of SIB 3 and 4 of the serving cell.[..]

Cell Selection Parameters


• WCEL: UseOfHCS (0)•This parameter indicates whether the serving cell belongs to a Hierarchical Cell Structure (HCS). •This parameter is part of SIB 11/12.•0 (HCS not used), 1 (HCS in use); default: 0.

• WCEL: Sintrasearch (10 dB)•The threshold for intra-frequency measurements, and for the HCS measurement rules.•This parameter is part of SIB 3.•[0 ... 20] dB, step 2 dB, default: 10 dB.

• WCEL: Sintersearch (8dB)•The threshold for inter-frequency measurements, and for the HCS measurement rules.•This parameter is part of SIB 3.•[0 ... 20] dB, step 2 dB, default: 8 dB.

• WCEL: Ssearch_RAT (4dB)•The RAT-specific threshold for inter-RAT measurement rules. •This parameter is part of SIB 3.•[0 ... 20] dB, step 2 dB, default: 4 dB.

Cell Reselection Parameters (1/6)


• WCEL: SHCS_RAT •The RAT specific threshold for inter-RAT measurement rules. •This parameter is part of SIB 3.•[-1 ... 91] dB, step 2 dB, default: -1 dB (UE sets this value to 0).

• WCEL: Slimit_SearchRAT •Threshold for skipping inter-RAT measurement rules in HCS. •Above this RAT specific threshold in the serving UTRA cell, the UE does not need to perform any inter-RATm measurements. •This parameter is part of SIB 3.•[0 ... 20] dB, step 2 dB, default: 2 dB.

• WCEL: SsearchHCS •Threshold for intra- and inter-frequency measurement rules in HCS. •Below this limit in the serving cell, the UE initiates measurements of all intra and inter-frequency neighbouring cells of the serving cell. •This parameter is part of SIB 3.•[-1 ... 91] dB, step 2 dB, default: -1 dB (UE sets this value to 0).

Cell Reselection Parameters (2/6) With HCS


• WCEL: NCr •This parameter defines the maximum number of cell reselections.•If the number of cell reselections during the TCrmax time period exceeds the value of NCr, high mobility has been detected. •Not used if TCrmax equals 'not used’.•This parameter is part of SIB 3.•[1 ... 16], default: 8.

• WCEL: TCrmax•The duration for evaluating the allowed amount of cell reselections. •If the number of cell reselections during the time period defined by Tcrmax exceeds Ncr, high mobility has been detected. •This parameter is part of SIB 3.•[0 (= not used), 30, 60, 120, 180, 240] seconds, default: 60 seconds.

• WCEL: TCrmaxHyst•Cell reselection hysteresis for reverting from UE high-mobility measurements.•The additional time period before UE reverts to low-mobility measurements.•This parameter is part of SIB 3.•[0, 10, 20, 30, 40, 50, 60, 70] seconds, default: 0 seconds.

Cell Reselection Parameters (3/6) With HCS


• WCEL: HCS_PRIO•This parameter defines the HCS priority level for a cell. •Value 0 indicates the lowest HCS priority and value 7 indicates the highest HCS priority.•[0 ... 7], default: 0.

• WCEL: QHCS•Quality threshold level for applying prioritised hierarchical cell re-selection for a cell. •Part of HCS Serving cell information (Qhcss). •This parameter is part of SIB 3. •[-24 ... 0] dB, step 0.5 dB, default: -24 dB.

• HOPS: AdjsHCSthreshold•Defines the threshold level which must be exceeded by the CPICH Ec/No of the intra-frequency neighbouring cell before the hierarchical cell re-selection becomes possible (Qhcsn).•[-24 ... 0] dB, step 0.5 dB, default: -24 dB.

• HOPI: AdjiHCSthreshold: •[-24 ... 0] dB, step 0.5 dB, default: -24 dB.

• HOPG: AdjgHCSthreshold: •[-110 ... -37] dBm, default: -110 dBm.

Cell Reselection Parameter (4/6) With HCS


• HOPS: AdjsTempOffset1•This parameter is used in the cell ranking between cells when the intra-frequency neighbour cell has the same HCS priority level as the serving cell. •[3, 6, 9, 12, 15, 18, 21, 100 (Infinity)] dB, default: 3 dB. •HOPI: AdjiTempOffset1, •HOPG: AdjgTempOffset1

• HOPS: AdjsTempOffset2•This parameter is used in the cell ranking between WCDMA cells when the intra-frequency neighbour cell has the same HCS priority level as the serving cell. •[2, 3, 4, 6, 8, 10, 12, 100 (Infinity)] dB, default: 2 dB. •HOPI: AdjiTempOffset2

• HOPS: AdjsPenaltyTime•Defines the time period during which the Temporary Offset 1/2 is applied in the cell re-selection procedure for the intra-frequency neighbour cell in question.•[0 ... 60] seconds, step 10 seconds, default: 0.•HOPI: AdjiPenaltyTime, •HOPG: AdjgPenaltyTime

Cell Reselection Parameter (5/6) With HCS


• WCEL: Qhyst1 (Qhyst2) (0)• Qhyst1 is used for TDD and GSM cells, and for FDD cells when cell

selection and re-selection quality measure is set to CPICH RSCP (CPICH Ec/No) (Qhyst1s/ Qhyst2s).

• This parameter is part of SIB 3.• [0 ... 40] dB, step 2 dB, default: 4 dB.

• HOPS: AdjsQoffset1 (AdjsQoffset2) (0) • This parameter is used in the cell re-selection and ranking between

WCDMA cells. • The value of this parameter is subtracted from the measured CPICH RSCP

(CPICH Ec/No) of the intra-frequency neighbour cell before the UE compares the quality measure with the cell re-selection/ranking criteria.

• [-50 ... 50] dB, default: 0 dB. • HOPS: AdjsQoffset1 (AdjsQoffset2), HOPG: AdjgQoffset1,

(AdjgQoffset2)

• WCELL: Treselection (2s)• The UE triggers the reselection of a new cell if the cell reselection criteria

are fulfilled during the time interval Treselection.• This parameter is part of SIB 3.• [0 ... 31] seconds, default: 0 seconds.

• The remaining parameters were already specified under Nokia Parameters for Cell Reselection (Part IV).

Cell Reselection Parameter (6/6)


Cell Reselection BSS-Parameter (1/3)

• Qsearch_I (7 always) and Qsearch_P (7 always) define 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

• FddQoffset (-32)and FddGprsOffset (-32) the non-GPRS/GPRS (respectively) capable UEs add 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 cellsValue 0 1 2 3 … 8 … 14 15

dBm -32 (infinity)

-28 -24 -20 … 0 … 24 28

Always select irrespective of

RSCP value

Reselect in case RSCP > GSM RXLev

(RLA_C) +28dB

If RLA_C < -94 UE starts 3G

measurements

UE always measures 3G cells

UE never measures 3G cells

If RLA_C > -70 UE starts 3G

measurements


Cell Reselection BSS-Parameter (2/3)• FddQmin(-12), defines minimum Ec/No threshold that a 3G cell must

exceed, in order the UE makes a cell reselection from 2G to 3G. This is the new mapping table

• FDD_REP_QUANT defines the reporting quantity for UTRAN cell (1=Ec/No or 0=RSCP, default 1). This parameter is hidden and it can not be tuned

• 3G_Search_PRIO parameter allows to extend the BSIC reporting interval from 10 s to 13s by checking the BSICs from non-serving BCCH carriers and also make WCDMA measurements as often as possible. Range is 0=no, 1=yes, default value .This parameter is hidden and it can not be tuned

Defined in the SI2quater and PSI3quater if PBCCH is allocatedParameterParameter

Name for Sys Info (SI)

Name for Sys Info (SI)

Qsearch_IQsearch_I

2quater2quater

Qsearch_PQsearch_P Qsearch_PQsearch_P

2quater2quater 3quater3quater

FDD_QMinFDD_QMin

2ter2ter

FDD_(GPRS)Qoffset

FDD_(GPRS)Qoffset

2quater2quater

FDD_REP_QUANT

FDD_REP_QUANT

2ter2ter

3G_search_PRIO

3G_search_PRIO

2(3)quarter(PBCCH)

2(3)quarter(PBCCH)

Fdd_Qmin mappingAif parameter 0 1 2 3 4 5 6 7Fdd_Qmin (old) [dB] -20 -19 -18 -17 -16 -15 -14 -13Fdd_Qmin (new) [dB] -20 -6 -18 -8 -16 -10 -14 -12


Cell Reselection BSS-Parameter (3/3)

Parameter Specification name

Nokia parameter

Range/Default value

Recommended value

GPRS threshold to search WCDMA RAN cells (QSRP)

Qsearch_P qSearchP 0…15/15 (never)

7 (always)

threshold to search WCDMA RAN cells (QSRI)

Qsearch_I qSearchI 0…15/15 (never)

7 (always)

GPRS fdd cell reselect offset (GFDD)

FDD_GPRS_Qoffset

FddGprsQoffset

-32…28 dB/ -32 (infinity)

Same as default

FDD cell reselect offset (FDD) FDD_Qoffset FddQoffset -32…28 dB/ -32 (infinity)

Same as default

minimum fdd threshold (FDM) FDD_Qmin FddQmin 0…7 / 7 (-12 dB)

Same as default

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

Ch

an

geab

leH

idd

en


SintrasearchSintersearchSsearchRAT m

No need to measure

neighbour cells

Intra- frequency

Sx=Squal (in FDD mode)

Intra-frequencyInter-frequency

serving cell

Example: Nokia Qqualmin = -18 dB, Sintrasearch = 10dB, Sintersearch = 8dB,Ssearch_RAT = 4dB

When to perform measurements

Intra-frequency

Inter-freqencyInter-RAT

Cell Reselection: Measurement RulesWithout HCS

-8 dB-10 dB-14 dBEC/N0 =


Cell Reselection Criterion

Re-selection if not serving cell


Qqualmeas (dB)(CPICH Ec/N0)

Qrxlevmeas (dBm)CPICH RSCP

Qqualmin(–24...0)

Qrxlevmin(–115...–25)

Srxlev > 0Pcompensation

Squal > 0 S-Criterionfulfilled

Squal >0 ANDSrxlev > 0

suitable

cell?

Cell Selection Criterion S (in the FDD mode)

Squal = Qqualmeas – Qqualmin

Srxlev = Qrxlevmeas - Qrxlevmin – Pcompensation

Pcompensation = max(UE_TXPWR_MAX_RACH – P_MAX, 0) (dB)


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

Rs = CPICH RSCP/GSM RSSI + Qhyst1Rn= CPICH_RSCP(n) or RXLEV(n) - Qoffset1

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

Rs = CPICH RSCP/GSM RSSI + Qhyst1Rn= CPICH_RSCP(n) or RXLEV(n) - Qoffset1

Rn higher in GSM cellRn higher in GSM cellYes No

Cell re-selection to GSM

Cell re-selection to GSM

Second ranking only for WCDMA cells based on CPICH Ec/No

Rs = CPICH Ec/No + Qhyst2Rn= CPICH Ec/No -Qoffset2

Second ranking only for WCDMA cells based on CPICH Ec/No

Rs = CPICH Ec/No + Qhyst2Rn= CPICH Ec/No -Qoffset2

Cell re-selection to WCDMA cell of highest

R value

Cell re-selection to WCDMA cell of highest

R value

GSM cell measurements

available If :

CPICH Ec/No - QqualMin < Ssearch_RAT

Rs = Serving WCDMA cell

calculation, with

hysteresis parameter

Rn = Neighbour WCDMA or GSM cell calculation with offset parameter

GSM cell measurements

available If :

CPICH Ec/No - QqualMin < Ssearch_RAT

Rs = Serving WCDMA cell

calculation, with

hysteresis parameter

Rn = Neighbour WCDMA or GSM cell calculation with offset parameter

If a TDD or GSM cell is ranked as the best cell, then the UE must perform cell re-selection to that TDD or GSM cell.

If a FDD cell is ranked as the best cell and cell_selection_and_reselection-quality_measure is set to CPICH RSCP, the UE shall perform cell re-selection to that FDD cell.

If a FDD cell is ranked as the best cell and cell_selection_and_reselection-quality_measure is set to CPICH Ec/No, the UE shall perform a second ranking of the FDD cells according to the R criteria using the measurement quantity CPICH Ec/No calculating the R values of the FDD cells.

Cell Reselection Algorithm from 3G to 2G

Qhyst1 = 0 dB

AdjsQoffset1 = 0 dB

QqualMin = -18 dB

SsearchRAT = 4 dB

AdjgQoffset1 = 0 dB

AdjgQrxlevMin = -101 dBm

Qhyst2 = 2 dB

AdjsQoffset2 = 0 dB

RS

CP

RS

SI


Cell Reselection Algorithm from 2G to 3G

Cell Reselection List

WCDMA cellreselection

BCCH: FddQmin, FddQOffset

DEFAULT:fdd cell reselect offset:

select always (value is -infinity)

minimum fdd threshold = -12 dB

DEFAULT:fdd cell reselect offset:

select always (value is -infinity)

minimum fdd threshold = -12 dB

Check levels every 5s from serving GSM cell

and best 6 GSM neighbour cells

UE starts WCDMA measurements if Rxlev running average (RLA_C) is below or above

certain threshold:RLA_C QsearchI or QsearchP

aveRxLev < Qsearch

UE starts WCDMA measurements if Rxlev running average (RLA_C) is below or above

certain threshold:RLA_C QsearchI or QsearchP

aveRxLev < Qsearch

UE can select WCDMA cell if the level of the serving GSM and non-serving GSM cells has been

exceeded by certain offset for a period of 5 s:CPICH RSCP > RLA_C + FddQoffset

RSCP > (aveRxLev) + -32

UE can select WCDMA cell if the level of the serving GSM and non-serving GSM cells has been

exceeded by certain offset for a period of 5 s:CPICH RSCP > RLA_C + FddQoffset

RSCP > (aveRxLev) + -32

UE will re-select WCDMA cell in case it's quality is acceptable:

CPICH Ec/No FddQminEcNo -8

UE will re-select WCDMA cell in case it's quality is acceptable:

CPICH Ec/No FddQminEcNo -8

Compare levels of all GSM cells

to WCDMAneighbour

Check quality of neighbour

WCDMA cells, no priorities between

WCDMA neighbours

05

.08

:Th

is m

ay

take

up

to

30

s

Qsearch = 7(always)

FddQoffset = -32 dB

FddQmin = -8 dB






• Handovers


RRC Connection Establishment UE-RAN

• The power level for sending of the RRC Connection Request message is set/calculated by the UE

• In average coverage conditions the RRC Connection Setup performance can be improved by tuning the open loop power control parameters

• These parameters are

• PRACH_preamble_retrans (7) & RACH_tx_Max (16dB)

• PowerOffsetLastPreamblePRACHmessage(2dB))

• PowerRampStepPRACHpreamble (2 dB)

• ptx = PtxPrimaryCPICH(30/33)-RSCP(CPICH) +RSSI(BS) + " PRACHRequiredReceivedCI “(25)



• If no acquisition indicator is received UE raises the transmission power by PowerRampStepPRACHpreamble which is a broadcast parameter

• This procedure is repeated until acquisition indicator is received, after which UE send the RACH message at power which offset by PowerOffsetLastPreamblePRACHmessage from the last preamble

• PRACH_preamble_retrans parameter determines how many times PRACH preamble can be sent within one preamble ramping cycle (SIB5&6)

• RACH_tx_Max defines how many times the PRACH preamble ramping cycle procedure can be repeated before UE MAC reports a failure on RACH transmission to higher layers (SIB5&6)



• Some of the early UEs are not capable of performing Open Loop PC accurately i.e. they have problems in RRC Connection Establishment

• The UE can not detect the SIB7 UL interference level correctly or cannot measure the CPICH RSCP accurately enough

• The situation can be corrected by increasing the parameter value PRACH_preamble_retrans or RACH_tx_Max

• Increasing the parameter values should be made with extra care as increasing the maximum UE TX power on RACH increases the UL load is as well:

• In case of problematic site which does not answer to PRACH at all due to BTS problems; increasing the power on RACH increases the UL interference on the surrounding sites






• Handovers


RADIO RESOURCE INDICATION (RRI) messagePrx Total is reported to the RNC for LC, AC and PS usage, on every RRIindicationperiod (200 ms)

The BTS is measuring:Prx Total

BTS sends the LASTEST averaged measurement result to RNC every RRI period

RNC is calculating a sliding window averaged value over the values given by RRI messagesFrame

measurements

Prx

…

RRIxRRIx+1RRIx+2 RRIx+n

Sliding window average result on every RRI periodWinAcRabSetup

UI(5)

m

jjntotalrx Totalx

mP

1

_ _Pr1

BTS uses ALPHA TRIMMED MEAN FILTERPrxAlpha (0)PrxMeasAvWindow

RAB Establishment


• Parameters to change in order to decrease the AC rejection of RAB (or RRC) connection due to the UL interference exceeding PrxTarget (PrxTraget (4dB)+ PrxOffset(1dB))

• Each BTS measures the total received interference power (PrxTotal)

• BTS uses Alpha Trimmed Averaging Window to calculate Prx_Total values

• BTS reports the PrxTotal results to the RNC by using RADIO RESOURCE INDICATION message every RRIndPeriod (200ms)

• RNC calculates simple arithmetic mean to obtain averaged PrxTotal values

• WinAcRabSetupUl (5) is a BTS parameter that defines the size of the load measurement averaging window used in RNC (AC) to average PrxTotal results

• Sliding averaging window provides new av PrxTotal value every RRI period

RAB Establishment


BTS sends periodically the received UL power to the RNCBTS sends periodically the received UL power to the RNC

Fractional load[0..1]

OVERLOADAREA

MARGINALLOADAREA

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 set thresholdsRNC compares the measured received power levels against the set thresholds

If measured UL (PrxTotal) load exceeds target thresholds (PrxTarget) AC may admit RT RABs and can admit NRT RABs to the cell. The NRT RAB bitrate can not be increased and remains at the same level as after previous scheduling period

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

Over Load

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 PrxTraget the RAB is admitted

rx_targetrx_ncrx_nc PPP

Uplink Admission Procedure


BTS sends periodically the total transmitted DL power to the RNCBTS sends periodically the total transmitted DL power to the RNC

RNC compares the measured transmitted power levels against the thresholdsRNC compares the measured transmitted power levels against the thresholds

If measured DL (PtxTotal) transmitted power exceeds target thresholds (PtxTarget) AC may admit RT RABs and can admit NRT RABs to the cell.The NRT RAB bitrates can not be increased and they remain at the same level as after previous scheduling period

If measured DL (PTxTotal) transmitted power exceeds overload thresholds (PtxTarget+PtxOffset) no RABs can be admitted and NRT bitrates are reduced until PtxTotal reaches again PtxTarget

Over Load

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 the RAB is admitted

OVERLOADAREA

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

Downlink Admission Procedure






• Handover


Handover Types

Intra-Frequency Handover

SOFTER HANDOVERMS simultaneously connected to multiple cells (handled by same BTS)No extra transmissions across Iub interfaceMobile Evaluated HandOver (MEHO)Both UL and DL: Maximum Ratio Combining (MRC) is occurring in rake receiver

SOFT HANDOVER MS simultaneously connected to multiple cells (from different BTSs)Extra transmission across Iub, more channel cards are neededMobile Evaluated HandOver (MEHO)DL/UE: MRC UL/RNC: Frame selection combining

HARD HANDOVERArises when inter-RNC SHO is not possible (Iur not supported or Iur congestion)Decision procedure is the same as SHO (MEHO)Causes temporary disconnection

Inter-Frequency Handover

Can be intra-BS, intra-RNC, inter-RNC Network Evaluated HandOver (NEHO)

Inter-RAT (Inter-system) Handover

Handovers between GSM and WCDMA (NEHO)


Handover Control Parameter Database Structure

RNC = Radio Network Controller level parameters

WBTS = Node B level parameters

WCELL = Cell level parameters

FMCx = Frequency Measurement Control parameters (S=intra-frequency set; I=inter-frequency; G=inter-RAT)

ADJx = Adjacent Cell parameters (S=intra-frequency set; I=inter-frequency; G=inter-RAT)

HOPx = Handover Path parameters (S=intra- frequency set; I=inter-frequency; G=inter-RAT)

RNCRNC

WBTSWBTS

WCELWCELADJSADJS

HOPSHOPS

ADJG

HOPG

FMCG ADJG

HOPG

FMCG

ADJI

HOPI

FMCI ADJI

HOPI

FMCIFMCI

FMCS


ADJS

ADJS

FMCS(NRT)

FMCS(RT)

HOPS(RT)

HOPS(NRT)

NrtHopsIdentifier = 1

RtHopsIdentifier = 2

HSDPAHopsIdentifier = 6

NrtHopsIdentifier = 1

RtHopsIdentifier = 2

HSDPAHopsIdentifier = 6 HOPSid = 1

HOPSid = 2

FMCSid = 1

FMCSid = 1

ADJSid = 1

ADJSid = 2

WCEL

WCEL

WCELWBTS

Each WCEL has associated 1 FMCS for NRT & 1 for RT & 2 for HSDPA, all can be reused for other cells.

Each ADJS has associated 1 HOPS for NRT & 1 for RT & 1 for HSDPA, sets can be reused for other cells.)

NrtFmcsIdentifier = 3

RtFmcsIdentifier = 40

HSDPAFmcsIdentifier = 50

NrtFmcsIdentifier = 3

RtFmcsIdentifier = 40

HSDPAFmcsIdentifier = 50

FMCS(HSDPA)

FMCSid = 2

HOPS(HSDPA) HOPSid = 6

HOPS(RT)

HOPS(NRT)

HOPSid = 1

HOPSid = 5

HOPS(HSDPA) HOPSid = 7

FMCS(RT&HSDPA)

FMCSid = 2

Handover Control Parameters Summary


Soft Handover

HC supports the following measurement reporting events and features:

• Event 1A: A primary CPICH enters the reporting range (Ncell addition)

• Event 1B: A primary CPICH leaves the reporting range (Ncell deletion)

• Event 1C: A non-active CPICH becomes better than an active primary CPICH (Ncell replacement)

• Cell individual offsets for modifying measurement reporting behaviour

• Mechanism for forbidding a neighbouring cell to affect the reporting range

Handover decision performed by RNC based on measurements and available resources

Admission Control can reject the branch addition in case the maximum load is achieved in DL (threshold + offset), valid both for RT and NRT bitrates.

Hard blocking may prevent branch addition


1A: A Primary CPICH Enters the Reporting Range

Reporting range defined by offset (point 1 on next slide) from either

(i) best CPICH Ec/Io in the AS, or(ii) sum of the AS measurement resultsset using ActiveSetWeightingCoefficient(0) (FMCS) (0 = use best CPICH : <>0 = use sum)

Offset defined using AdditionWindow (4/RT & 2.5 NRT) (FMCS)

Event 1A triggered when CPCIH3 Ec/Io enters UE reporting range (point 2)

If CPICH3 Ec/Io remains within reporting range for a time period defined by AdditionTime (FMCS) , and the AS is not full, UE sends measurement report to RNC which adds Ncell3 to AS if possible (point 3)

AdditionTime (320ms) defines the 'time-to-trigger' interval between the Ncell first entering the reporting range and the UE sending the measurement report to the RNC

If RNC is unable to add Ncell to AS, UE will wait for a period of time, defined by AdditionReportingInterval (0.5) (FMCS) (point 4) after the first measurement report, before sending further reports periodically, with interval AdditionReportingInterval, until (a) Ncell moves out of reporting range, or (b) RNC adds Ncell to AS.

2

3

1

4


1A: A Primary CPICH Enters the Reporting Range

Strongest CPICH in AS

time

Ec/No

P CPICH 3

P CPICH 1

P CPICH 2

1

2

AdditionWindow

AdditionTime

AdditionReportingInterval

RNC

MeasurementReport

Add tothe AS?

no

ActiveSetWeightingCoefficient

34


1B: A Primary CPICH Leaves the Reporting Range

Event 1B triggered when CPICH3 EC/I0 drops out of the UE reporting range for a defined period of time (point 1 on next slide)

Reporting range = Strongest CPICH in AS – DropWindow (6/RT & 8/NRT) (FMCS) (point 2)

Time-to-trigger period set using DropTime (640ms) (FMCS) (point 3)

UE sends RNC measurement report on expiry of DropTime to remove Ncell (CPICH3) from AS.

RNC drops the cell from the AS and UE drops the cell from the AS to the Neighbour Set

1

2

3


Strongest CPICH in AS

time

Ec/No

P CPICH 3

P CPICH 1

P CPICH 2

1

2

3

DropWindow

DropTime

MeasurementReport

1B: A Primary CPICH leaves the Reporting Range

Remove the

reported cell from the AS


1C: A non-active CPICH becomes better than an active primary CPICH

UE AS full (MaxActiveSetSize = 3)

Event 1C triggered when CPICH4 EC/IO > CPICH3 in AS by a defined margin, ReplacementWindow (2 dB) (FMCS). (point 1 in next slide)

Sending of measurement report to RNC can be delayed by using 'time-to-trigger' period set by ReplacementTime (320ms) (FMCS)

If 'time-to-trigger' is used difference between CPICH4 and CPICH3 must be ReplacementWindow for the period of ReplacementTime (point 2)

If the RNC is not able to replace the Ncells, the UE continues to send measurement reports periodically, with interval ReplacementReportingInterval (0.5S), to the RNC until (a) CPICH4 falls out of ReplacementWindow or (b) RNC replaces CPICH4 by CPICH3 (point 3)

3

1

2


time

weakest CPICH3 in AS

Ec/No

P CPICH 3

P CPICH 1

P CPICH 2

P CPICH 4

AS has 3 cells

ReplacementReportingInterval3

1

2

ReplacementWindow

ReplacementTime

MeasurementReport

RNC

ASupdate?

no

1C: A non-active CPICH becomes better than an active primary CPICH


Inter-RNC Soft HO

Inter-RNC soft Handovers are performed if:

• RNC Iur list: IurUPSupport (1) indicates whether nighbouring RNC supports user plane over Iur, thus if it’s possible to initiate inter-RNC SHO procedure

• HOPS: EnableInterRNCsho (1) indicates whether adjacent cell can participate in a inter-RNC SHO

EnableInterRNCsho

cell3 cell2

cell1

cell4

cell6

cell5

RNC RNCIurUPSupport

EnableInterRNCsho

Otherwise, HC checks whether Hard Handover is possible.

(UE-involved SRNS relocation is needed)


Hard Handover (1/3)

If RNC is not able to add (Event 1A) to or replace (Event 1C) an Ncell from the AS, UE sends periodic measurement reports (AdditionReportingInterval / ReplacementReportingInterval) until;

Ncell is added/replaced in to AS

Ncell leaves reporting range

HO no longer required (e.g. different Ncell enters AS)

RNC may not be able to add/replace Ncell due to (a) Iur congestion or (b) inter-RNC SHO is prevented due to setting of EnableInterRNCsho (HOPS) (Point 1 in next slide)

If CPICH EC/NO of non-active Ncell continues to increase it will cause additional interference due to a non-optimal connection (point 2)

1

2


Hard Handover (2/3)

To avoid excessive uplink interference, RNC will perform an intra-frequency hard Handover if either of the following criteria are met

AveEcNoDownlink + HHoMarginForAveEcNo(1dB)(n) < AvEcNoNcell(n)

EcNoDownlink + HHoMarginPeakEcNo(2dB)(n) < EcNoNcell(n)

AveEcNoDownlink and AvEcNoNcell(n) = measured values for the best AS cell and the nth NS cell, averaged over EcNoAveragingWindow (8dB) measurements

EcNoDownlink and EcNoNcell(n) = instantaneous values

HHoMarginForAveEcNo (HOPS) = average Ec/N0 margin [-6 … 6]dB, default 1dB

HHOMarginPeakEcNo (HOPS) = peak Ec/N0 margin [-6 … 6]dB, default 2dB

3


Time

Ec/No

P CPICH 3

P CPICH 1

P CPICH 2Reporting

range

AdditionReportingInterval

1

2

HHOMarginAverageEcNoHHOMarginPeakEcNo

1A (AdditionTime = 0)

AveEcNoDownlink + HHOMarginAveEcNo < AveEcNoNcellEcNoDownlink + HHOMarginPeakEcNo < EcNONcell

Hard Handover (3/3)

3


If difference between the best AS cell and the NS cell is too high and SHO is not performed, the RRC connection is released to avoid excessive interference

Why might an AS update not be possible?• Excessive load in the neighboring cell

• Hard blocking in the target BTS

• Unavailability of DL spreading codes

• Iub transport resources unavailable

This function is activated by EnableRRCRelease (0) (HOPS parameter)/0=no (def),1 =yes

The RRC connection is released if either:

AveEcNoDownlink + ReleaseMarginForAveEcNo (2.5dB)(n) < AvEcNoNcell(n)

EcNoDownlink + ReleaseMarginPeakEcNo(3.5)(n) < EcNoNcell(n)

ReleaseMarginForAveEcNo (HOPS) = average Eb/N0 margin [-6 … 6] dB, default 2.5dB

ReleaseMarginPeakEcNo (HOPS) = peak Eb/N0 margin [-6 … 6] dB, default 3.5dB

Emergency calls are exempt from RRC Connection Release process.

RRC Connection Release


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 startIF/IS measurements

RNC commands selected UE(s) to startIF/IS measurements

Measurements are done in Compressed Mode (CM)

Measurements are done in Compressed Mode (CM)

UE reports GSM cells withstrongest RSSI signals to RNC

UE reports GSM cells withstrongest RSSI signals to RNC

RNC makes HO decision andcommands 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

Different decision methods for IF HOOnly one decision method for IS HO

5 Coverage/Capacity HO Reasons

About 25 HO parameters

Reporting cells are active set cells (max 3) + max 6 IFHO, max 6 ISHO neighb.

Max 32 neighbours could be measured

(31 Intra-Freq neighbours)48 Inter-Freq neighbours 32 Inter-System neighbours can be measured

3G->2G Handover Process


1. DL DPCH approaches itsmaximum allowed powerFMCG: GSMcauseTxPwrDL

2. Quality deterioration report from UL outer loop PCFMCG: GSMcauseUplinkQuality

4. UE Tx power approaches itsmaximum allowed power, event 6A/6DFMCG: GSMcauseTxPwrUL

5 . Low measured absoluteCPICH RSCP, events 1E/1FFMCG: GSMcauseCPICHrscp

3. Low measured absolute CPICH Ec/No, event 1E/1F FMCG: GSMcauseCPICHEcNo

HO trigger

6 . Others e.g. Traffic & load reason IS-HO, etc

Frequency Measuring Control for Inter-System (GSM) = FMCG

3G->2G ISHO Trigerring Reason


Measurement trigger CPICH Ec/No (1/3)

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

all)

time

Cell 1 Cell 2

Cell 3

absolutethreshold

e.g

. P

-CP

ICH

Ec/N

o

1E: HHoEcNoCancel (-9dB)

1E: HHoEcNoCancelTime (100ms)

1F: HHoEcNoThreshold(-12dB)

1F: HHoEcNoTimeHysteresis (100ms)



RNC starts IF/IS measurement when event 1F occurs for all cells in the active set: A Primary CPICH becomes less than an absolute threshold

RNC stops IF/IS measurement when event 1E occurs for at least one cell of the active set : A Primary CPICH becomes better than an absolute threshold

Note:IF/IS measurements can be stopped if event 1Fs are cancelled by events 1E only when IFHO/ISHO was not successful and only inside the time between CM measurements, specified by the time InterFreqMinMeasInterval(6s) GsmMinMeasInterval(2s)/default 10s, recommendation 2s.

Filtering applied before event evaluation in the UE:

FMCS: EcNoFilterCoefficient/0= 200ms filtering period (600ms)



Event 1E parameters:Triggering conditions: Active set cells

Hysteresis: not used in 1F

Threshold used frequency: FMCS : HHoEcNoCancel(-9)/ -20 dB

Time-to-trigger: FMCS: HHoEcNoCancelTime (100ms)/ 1280 ms

Amount of reporting: infinity

Reporting interval: not applied

Reporting cell status: max 3 active cells

Event 1F parameters:Triggering conditions: Active set cells

hysteresis: not used in 1F

Threshold used frequency: FMCS : HHoEcNoThreshold (-12)/ - 22 dB (range 0..-24 dB)

Time-to-trigger: FMCS: HHoEcNoTimeHysteresis(100ms) / 640 ms (range 0..5000ms)





Measurement trigger CPICH RSCP (1/2)

UE continually monitors pilot channels of BTSs in AS.

If RSCP of a Node B falls below threshold, HHoRscpThreshold (105dbm), UE sends event 1F report.

RNC starts IF/IS measurements when event 1F occurs for all cells in AS.

RNC stops IF/IS measurements when event 1E occurs for at least one cell of AS.

Note:IF/IS measurements can be stopped if event 1Fs are cancelled by events 1E only when IFHO/ISHO was not successful and only inside the time between CM measurements, specified by the time InterFreqMinMeasInterval(6s) GsmMinMeasInterval(2s)/default 10s, recommendation 2s.

UE filtering applied before event evaluation using HHoRscpFilterCoefficient (200ms) (FMCS) /200ms, range 200…1600ms


Measurement trigger CPICH RSCP (2/2)Event 1E (A primary CPICH exceeds an absolute threshold) parameters:

Triggering conditions: Active set cellshysteresis: not used in 1EThreshold used frequency: (FMCS) : HHoRscpCancel(-102dBm)/ - 100 dBmTime-to-trigger: (FMCS): HHoRscpCancelTime(100ms)/ 1280 msAmount of reporting: infinityReporting interval: not appliedReporting cell status: max 3 active cells

Event 1F (A primary CPICH falls below an absolute threshold) parameters:Triggering conditions: Active set cells

Hysteresis: not used in 1F

Threshold used frequency: HHoRscpThreshold RT (-12dB)/NRT (-15dB)(FMCS)/ - 105 dBm

Time-to-trigger: HHoRscpTimeHysteresis (-100ms)(FMCS)/ 640 ms





Decision Algorithm

UE Tx Power (Event 6A)•Threshold:GsmUETxPwrThrXX •L3 filter: GsmUETxPwrFilterCoeff•Hysteresis margin: GsmUETxPwrTimeHyst•Data rate threshold HHOMAxAllowedBitrateUL

UL Quality•Timer:ULQualDetRepThreshold•Data rate threshold HHOMAxAllowedBitrateUL

DL DPCH power•Threshold: GsmDLTxPwrThrXX•Data rate threshold HHOMAxAllowedBitrateDL

(XX=AMR,CS,NrtPS,RtPS)

CPICH RSCP (Event 1F)

•Thresholds:HHoRscpThreshold HHoRscpCancelL3 filter: HHoRscpFilterCoefficient•Timers:HHoRscpTimeHysteresisHHoRscpCancelTime

CPICH Ec/Io (Event 1F)•Thresholds:HHoEcNoThresholdHHoEcNoCancel•L3 filter:Done already for SHO•Timers:HHoEcNoTimeHysteresisHHoEcNoCancelTime

AdjgTxPwrMaxTCHAdjgRxLevMinHO (n)GsmMeasAveWindow

GsmMeasRepIntervalGsmNcellSearchPeriodGsmMinMeasIntervalGsmMaxMeasPeriod

Handover Triggering

Handover Execution2G-to-3G back prevention

GsmMinHoInterval

GSM measurement reporting

ISHO Summary Parameters


Handover Triggering Thresholds set in BSCHandover Triggering Thresholds set in BSC

Inter-RAT measurements when: The RXLEV of the serving cell is above or

below the given threshold Qsearch_C

Inter-RAT measurements when: The RXLEV of the serving cell is above or

below the given threshold Qsearch_C

Handover Decision is done in case of• Load of the serving cell > Load_Threshold• and CPICH Ec/No> min Ec/No Threshold

Handover Decision is done in case of• Load of the serving cell > Load_Threshold• and CPICH Ec/No> min Ec/No Threshold

MS reports best UTRAN cell based on measurement results

MS reports best UTRAN cell based on measurement results

Handover command is send to MSCHandover command is send to MSC

Latest after 5 s(one WCDMA band)

MS is measuring the UTRAN cells continuously if they are defined as a neighbour, measurements are done during idle periods

2G->3G Handover Process


2G->3G ISHO Parameters


• The following conditions have to be satisfied, before an inter-system Handover can be conducted. The best neighboring cell must fulfil following criterion („best“ according to Ec/No):

AVE_RXLEV_NCell(n) > AdjgRxLevMinHO(-95dBm)(n) + max(0, AdjgTxPwrMaxTCH(n) - P_max)where:

• AVE_RXLEV _Ncell(n) is the averaged GSM carrier RSSI value of the GSM neighbor cell(n), averaging done directly from dBm values (no linear averaging) -> GSMMeasAveWindow(6) / 6, 1…32 meas report

• AdjgRxLevMinHO(-95dBm)(n) determines the minimum Required RSSI (dBm) level of the neighbor cell(n).

• AdjgTxPwrMaxTCH(30dBm for1800Mhz/33dBm 900Mhz)(n) indicated the maximum Tx power level (dBm) an UE may use in GSM neighbor cell(n).

• P_MAX is the maximum UE power capability.• If several GSM cells fulfil the equation above, cells are ranked based on HOPG:

AdjgPriorityCoverage(0)/0, range 0…7• A cell is ranked higher than another cell if it has a higher priority level

even though its signal strength condition was worse• 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 neighbor hood.

• FMCG NcellSearchPeriod (0)/ 0

ISHO Decision (1/2)


AdjgRxLevMinHO(n)

max(0, AdjgTxPwrMaxTCH(n) - P_max)

AVE_RXLEV_NCell(n) > AdjgRxLevMinHO(n) + max(0, AdjgTxPwrMaxTCH(n) - P_max)

GSM cell

ISHO Decision (2/2)


Compressed Mode (CM)

CM was introduced to WCDMA to allow inter-frequency (system) Handovers

CM is used to create idle periods (gaps) in the transmission during which ncell measurements on another frequency can be made

Gaps can be created using single or double frame approach (Nokia supports both)

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 Spreading Factor Halving and Higher Layer Scheduling

Normal frame Normal frame

Measurement gapMeasurement gapPower / Data Rate

CompressedMode

Normal frame


Compressed Mode Parameters

CM can be activated/deactivated by CMmasterSwitch (RNC)(0) /0=in use (def)

Maximum number of UEs in CM is controlled through MaxNumbUECMcoverHO (RNC)(16)/16 (range 0..255)

The number of UEs in DL CM depends on the PtxTotal value

The number of UEs in UL CM depends on the PrxTotal value


How many UEs in Compressed Mode ?

PtxTarget/PrxTarget

DL/ULtransmission power

Load

PtxOffset/PrxOffset

New UEs can be switched to CM when:

Pxx_Total < Pxx_Target & # of UEs in CM <

MaxNumbUECMcoverHO

One new UE in CM can be allowed

if the limit is not reached

No new UE can be in CM here


Specific HSDPA Parameter


User plane Iub capacity allocation

• The user plane Iub capacity is shared by the R99 and HSDPA traffic.

• The HSDPA Iub resource allocation is managed with parameters:

SharedHSDPAAllocation (WBTS object) (1.3Mbps 2E1 & 2 Mbps 3E1)

• capacity reservation from the user plane VCC for HSDPA

NbrOfOverbookedHSDPAUsers (WBTS object) (32)

• determines the number of HSDPA users that are allowed in the VCC even if the SharedHSDPAAllocation has failed

ReleaseTimerForSharedHSDPAallocation (WBTS object) (3 minutes)

• timer that keeps SharedHSDPAAllocation reservation after the last HSDPA user has left

SharedHSDPAFlowControlAllocation (WBTS object) (4Mbps 2E1, 4.8Mbps (3E1)

• sets an upper limit to the allowed HSDPA bandwidth


Time

VCC capacity

R99 DCH rate

Available Iub bandwidth for the HSDPA traffic

Shared HSDPAallocation

Initially, the R99 traffic can use the whole VCC capacity.

If the HSDPA user enters at t0, SharedHSDPAAllocationSharedHSDPAAllocation reservation is not possible due to DCH usage.

Then the Iub reservation gives to HSDPA all what is available at t0 (best effort).

t0


Time

VCC capacity

R99 DCH rate

Available Iub bandwidth for the HSDPA traffic

Let’s assume now that at t1 another HSDPA user tries to enter the system.

Again, SharedHSDPAAllocationSharedHSDPAAllocation reservation fails due to DCH usage.Then, its admission depends on the parameter

NbrOfOverbookedHSDPAUsers:NbrOfOverbookedHSDPAUsers:

If =1, the user at t1 is rejectedIf > 1, the user at t1 is admittedIf = 0, the user at t1 is admitted as the feature is disabled with value

0

At t2 a third user tries to enter and the capacity allocation is the SharedHSDPAallocationSharedHSDPAallocation

t0 t1 t2



R99 DCH rate

Time

VCC capacityPeak R99 DCH rate

AvailabAvailable le

bandwibandwidth fordth forHSDPAHSDPA

VCC Capacity- R99 DCH peak rate

VCC capacity

Peak R99 DCH rate < VCC capacity

Peak R99 DCH rate < VCC capacity

Available bandwidth for the HSDPA traffic SharedHSDPAallocation

If reservation succeeds, the bandwidth reserved to HSDPA is equal to SharedHSDPAallocation (if reservation has succeeded). This is flow level capacity, on packet level each packet is transmitted with the full capacity of the virtual connection.

SharedHSDPAallocation a.k.a “Dummy reservation” as this is capacity hidden from the CAC.

This reservation is maintained as long as there are active HSDPA users in the BTS. When the last MAC-d terminates and no new ones enter during a period determined by [WBTS] Release timer for shared HSDPA allocationRelease timer for shared HSDPA allocation, the capacity reservation is released. This means that the whole of the Iub capacity is again available for DCH usage.



Time

VCC capacity

R99 DCH rate

Maximum bandwidth for the HSDPA traffic SharedHSDPAFlowControlAllocation

It is possible to send MAC-d flow data over Iub faster than what is reserved for HSDPA.

Shared HSDPA flow control allocationShared HSDPA flow control allocation controls the maximum share of Iub that HSDPA can try to use.

Range 500 kbps … 14.4 Mbps in 100 k steps Should be bigger than SharedHSDPAallocation.

SharedHSDPAFlowControlAllocation



Iub HSDPA allocation

When the capacity reservation for HSDPA traffic in the Iub interface is activated, the reservation is made when the first MAC-d flow enters the Iub.

The transport capacity reserved for HSDPA is always available for MAC-d flows over Iub regardless of the load.

The ShareHSDPAAllocation reservation will fail if there is no capacity available due to DCH usage.

If this happens, the HSDPA data is transported as best effort traffic without reservation and is therefore subject to buffering depending on the current DCH load.

In this case, the HSDPA data is able to utilize only the capacity which is left over from the DCH traffic. Every time a new MAC-d flow enters the Iub, the retry for ShareHSDPAAllocation reservation is made.

If the reservation succeeds, Shared HSDPA allocation Shared HSDPA allocation is a virtual AAL2 reservation inside the shared VCC. The reserved capacity is for all MAC-d flows on route, and not done for any specific MAC-d flow. In other words, some transport resources are reserved from VCC towards BTS, but no AAL2 connection is established over Iub. Therefore, the reservation of shared HSDPA transport resources in RNC is not visible to BTS.


Power Allocation

• HSDPAPriority (RNC object) (1)• Defines priority between NRT DCHs and MAC-d flows.• should be in line with strategy.

• PtxTargetHSDPA (WCEL object) (38.5 dBm)• Used instead of PtxTraget.• Default, 38.5 dBm• Should be in-line with PtxMaxHSDPA

• PtxOffsetHSDPA (WCEL object) (0.8)• Used instead of PtxOffset.• Default, 0.8 dB• Should be in-line with PtxMaxHSDPA

• PtxMaxHSDPA (WCEL object) (37.8 dBm)• Defines maximum HSDPA transmission power.• should be in-line with strategy


Power allocation

Max power

Node-B Tx power

HSDPAPriority =1

• Event A: First MAC-d flow entering the cell

PtxNC<=PtxtargetHSDPA-> HS-DSCH is selected,

otherwise DCH scheduling.• When HSDPA power is in use:

PtxNC target is Ptxtarget. NRT DCH scheduling up to PtxtargetHSDPA.

• Event B:PtxnonHSDPA>=PtxtargetHSDPA+Ptxoffset

HSPA- Overload control actions for NRT DCH(s) started

• Event C:PtxnonHSDPA>=PtxtargetHSDPA+Ptxoffset

HSDPA- No more NRT DCHs, all MAC-d flows in the cell are released A

Ptx_offset_HSDPAPtxnonHSDPA

PtxNC

Ptx_target_HSDPA

B

Ptxtotal

Ptx_target

C

PtxMaxHSDPA


Power allocation

HSDPAPriority =2

• Event A: First MAC-d flow entering the cell

Ptxtotal<=PtxtargetHSDPA-> HS-DSCH is selected,

otherwise DCH scheduling.• When HSDPA power is in

use: PtxNC target is Ptxtarget. NRT DCH scheduling up to PtxtargetHSDPA.

• Event B:PtxnonHSDPA>=PtxtargetHSDPA+Ptxoffset

HSDA- All MAC-d flows in the cell released

• Event C: (normal NRT DCH overload control)

Ptxtotal>=Ptxtarget+Ptxoffset- Overload control actions for NRT DCH(s) started A B C

Max power

Node-B Tx power

Ptx_offset_HSDPA

PtxnonHSDPA

PtxNC

Ptx_target_HSDPA

Ptxtotal

Ptx_target

Ptx_offset

PtxMaxHSDPA


PtxtargetHSDPA AND PtxoffsetHSDPA

STRATEGY: STRATEGY: 1) The ratio between PC headroom and Variable Power shall remain the same 1) The ratio between PC headroom and Variable Power shall remain the same after the after the introduction of HSDPA because HSDPA does not require any power control introduction of HSDPA because HSDPA does not require any power control headroomheadroom2) When HSDPA power is allocated DCH Power increases to to keep BLER targets, 2) When HSDPA power is allocated DCH Power increases to to keep BLER targets, so in order to avoid HSDPA power to be allocated and soon released DCH power so in order to avoid HSDPA power to be allocated and soon released DCH power increase << PtxoffsetHSDPAincrease << PtxoffsetHSDPA


HS-DSCH Release

• MACdflowutilRelThr (256bps) (RNC object)• Defines the low utilization threshold of the throughput

measurement of the MAC-d flow.• Default 256 bps.

• MACdflowutilTimetoTrigger (0s) (RNC object)• Defines the low utilization time to trigger timer• Default, 0s.

• MACdflowthrouhgputRelThr(0bps) (RNC object)• Defines the low throughput threshold of the throughput

measurement of the MAC-d flow.• Default 0 bps.

• MACdflowthroughputTimetoTrigger(5s) (RNC object)• Defines the low throughput time to trigger timer• Default, 5s

• HsdschGuardTimeLowThroughput(30s) (RNC object)• Defines time when HS-DSCH allocation is not allowed for a UE,

after the MAC-d flow is release due to low throughput.


HS-DSCH & MAC-d release: low utilization

Throughput

PDUs in buffer

MACdflowUtilRelThr

MACdflowthrougputRelThr

MACdflowUtilTimetoTrigger

Low utilization indication


HS-DSCH & MAC-d release : low throughput

Throughput

PDUs in buffer

MACdflowUtilRelThr

MACdflowthrougputRelThr

MACdflowUtilTimetoTrigger

Low throughput indication

MACdflowThroughputTimetoTrigger

HsdschGuardTimerLowThroughput, def. 30s


HS-DSCH & MAC-d release

UE moved to Cell FACH

L3 starts procedure to release UL NRT DCH and MAC-d flow if:• MAC-d flow has low utilization and UL NRT DCH can be released

(InactivityTimer).

Or • MAC-d flow has low throughput and UL NRT DCH can be released

(InactivityTimer). In this case UE specific timer HsdschGuardTimerLowThroughput is started.

If MAC-d flow has both low utilization and low throughput conditions valid at the same time, the functionality described in case of low utilization is followed

HS-DSCH & associated DCHs

released


Documents

06 3G and HSDPA Important Parameters