3g Radio Parameter Ericsson
3g Radio Parameter Ericsson
3g Radio Parameter Ericsson
TELKOMSEL
Contents
Idle Mode Handover Power Control Capacity Management Channel Switching HSDPA
Qqualmeas > qQualMin (-18dB) and Qrxlevmeas > qRxLevMin (-115dBm) - max (maxTxPowerUl (24dB) - P, 0)
qQualMin : indicates the minimum required quality value in the cell. It is sent in system information, in SIB3 for the serving cell, and in SIB11 for adjacent cells qRxLevMin : indicates the minimum required signal strength in the cell. It is sent in SIB3 for the serving cell and in SIB11 for adjacent cells maxTxPowerUl : indicates the maximum allowed transmission power when the UE accesses the system on RACH. It is broadcast in SIB3
qQualMin
(18)
Squal = Qqualmeas qQualMin
qRxLevMin
(115) suitabl e cell?
Pcompensation Pcompensation = max(maxTxPowerUl P, 0) (dB)
Srxlev > 0
qualMeasQuantity =x
The decision about when GSM measurements are performed is made using the sRatSearch parameter in relation to Squal and the sHcsRat parameter in relation to Srxlev:
If the Squal > sRatSearch and the Srxlev > sHcsRat, the UE does not need to perform measurements on GSM cells. If the Squal <= sRatSearch value and/or the Srxlev <= sHcsRat value, the UE performs measurements on GSM cells.
Squal <= sRatSearch Qqualmeas-qQualMin <= sRatSearch Qqualmeas <= qQualMin (-18dB) + sRatSearch (4dB) Srxlev <= sHcsRat Qrxlevmeas-qRxLevMin Pcompensation <= sHcsRat Qrxlevmeas <= qRxLevMin (-107dBm) + 0 + sHcsRat (3dB)
First ranking of all the cells based on CPICH RSCP (WCDMA) and RSSI (GSM)
qHyst1 = 4 dB qOffset1sn = 0 dB
qQualMin = -18 dB Rs = CPICH RSCP/GSM RSSI + Qhyst1 sRATsearch = 4 dB Rn= CPICH_RSCP(n) or RXLEV(n) - Qoffset1 qOffset1sn = 7 dB qRxlevMin = -107 dBm
Yes
No
Qhyst2 = 4 dB qOffset2sn = 0 dB
Cell re-selection to GSM 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. Second ranking only for WCDMA cells based on CPICH Ec/No Rs = CPICH Ec/No + Qhyst2 Rn= CPICH Ec/No -Qoffset2
RSSI
RSCP
Value
10
14
15
dBm
-98
-94
-74
Always
-78
-74
-70
-54
Never
FDDQOFF
Value
dBm
0
-32 (infinity)
1
-28
2
-24
3
-20
8
0
14
24
15
28
DEFAULT: fdd cell reselect offset: select always (value is -infinity) minimum fdd threshold = -12 dB
QSI = 7(always)
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 QSI or QSC
FDDQOFF = -32 dB
05.08:This may take up to 30s
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 + FDDQOFF RSCP > (aveRxLev) + -32
FDDQMIN = -13 dB
UE will re-select WCDMA cell in case it's quality is acceptable: CPICH Ec/No FDDQMIN EcNo -13
accessClassNBarred
Indicates whether or not access class N is barred ( N = 0 to 15). 0 : not barred 1 : barred Start from least significatant bit: bit 0 : class 0 bit 1 : class 1 bit 2 : class 2 ....... bit 15 : class 15 Indicates the frequency band of the external GSM cell. The BCCH frequency is unique for all GSM bands except the two GSM bands DCS1800 and PCS1900, so the band indicator is needed to discriminate between the two. When the ExternalGsmCell has a BCCH frequency indicating some other frequency band, then the band indicator is not needed and may be set to "Not applicable".
bandIndicator
BCCH frequency code in the GSM cell. Contains the absolute radio frequency channel number of the BCCH channel for the GSM cell. It uniquely identifies the BCCH. Indicates if this cell shall be reserved for operator use. If it is reserved, there will be no service to the UEs. Fach Measurement Occasion Cycle Length coefficient. A factor used when the UE performs inter-frequency and inter-system measurements. The UE uses this parameter to calculate the interval length in order to determine the repeating cycle of the measurement. 0 : not broadcasted in SIB 11. 1 : not used. 2 : not used. 3 : used when inter frequency and GSM neighbours. 4 : used when inter freqency or GSM neighbours. 5 - 12 not used.
interFreqFddMeasIndicator
maxTxPowerUl (serving cell, WCDMA neighbor within same RNC) maxTxPowerUl (WCDMA neighbor belonging to another RNC) maxTxPowerUl (GSM neighbor) mcc The MCC part of the PLMN identity used in the GSM radio network.
The PLMN identity consists of two parts: 1. MobileCountryCode, MCC, 3 digits 2. MobileNetworkCode, MNC, 2 or 3 digits Example: If MCC=125 and MNC=46 then plmnId=12546.
mnc
The MNC part of the PLMN identity used in the radio network. The PLMN identity consists of two parts: 1. MobileCountryCode, MCC, 3 digits 2. MobileNetworkCode, MNC, 2 or 3 digits Example: If MCC=125 and MNC=46 then plmnId=12546.
nmo primaryScramblingCode
Network operation mode that indicates whether the Gs interface between the SGSN and MSC/VLR is installed. The primary downlink scrambling code to be used in the external cell.
qHyst2
The hysteresis value of the serving cell. Used to perform cell ranking for the serving cell. Resolution: 2
qOffset1sn
Signal stength offset between source and target cells. Used when the IE "cell_selection_and_reselection_quality_measure" in SIB 11/12 is set to "CPICH RSCP". This is configured through UtranCell::qualMeasQuantity. Unit: 1 dB Resolution: 1 -50 : -50dB -49 : -49dB -48 : -48dB ...... 50 : 50dB
qOffset1sn (WCDMA neighbor relation) qOffset1sn (GSM neighbor relation) qOffset2sn (WCDMA neighbor relation) qQualMin
Used in UE functions for cell selection/reselection in idle mode and connected mode. Minimum required (acceptable) quality level in the cell (dB). Used to set cell border between two cells. Unit: 1 dB Resolution: 1 -24 : -24dB ...... 0 : 0dB 100 : Indicates that the minimum quality level has not been specified by the operator. The parameter is then not present in SIB11 for this neighbour. The UE will use the serving cell value (UtranCell MO value) instead.
qQualMin (serving cell, WCDMA neighbor within same RNC) qQualMin (WCDMA neighbor belonging to another RNC)
qRxLevMin (serving cell, WCDMA neighbor belonging to same RNC) qRxLevMin (WCDMA neighbor belonging to another RNC) qRxLevMin (GSM neighbor) Used in UE functions for cell selection/reselection in idle and qualMeasQuantity
connected mode. Cell selection and reselection quality measure. Value launched by System information (SIB3, SIB11 and SIB12).
sHcsRat
RAT specific threshold in the serving cell used in the inter-RAT measurement rules. This parameter is used by the UE to decide when to start GSM measurements for cell reselection, if the serving cell is indicated to belong to a Hiearachical Cell Structure (HCS) GSM measurements in idle mode and state CELL_FACH are started by the UE when RSCP <= qRxLevMin + sHscRat. If sHcsRat is set to a negative value, this will be interpreted as 0 by the UE (according to 3GPP TS 25.331). Unit: 1 dB Resolution: 2
sIntraSearch
The decision on when measurements on intra frequencies shall be performed. If a negative dB value is configured, the UE interprets the negative value as 0 dB. Unit: 2 dB Resolution: 1 0 : not sent 1 : -32 dB 2 : -30 dB ... 27 : 20 dB
sRatSearch
The decision on when measurements on GSM frequencies shall be performed is made using this parameter in relation with Squal. If S_qual > this parameter, UE need not perform measurements on GSM cells. If S_qual <= this paramter, UE shall perform measurment on GSM cells. If a negative value is configured the UE interprets the negative value as 0. Unit: 1dB Resolution: 2 -32 : -32dB -30 : -30dB ......
uarfcnDl
Downlink Utra Absolute Radio Frequency Channel Number. Specifies the channel number for the central DL frequency. The mapping from channel number to physical frequency is described in 3GPP specification TS 25.104. Unit: Channel number Resolution: N/A
uarfcnUl
Uplink Utra Absolute Radio Frequency Channel Number. Specifies the channel number for the central UL frequency. The mapping from channel number to physical frequency is described in 3GPP specification TS 25.104. Unit: Channel number Resolution: N/A
att
Indicates to the UE whether IMSI attach/detach is allowed. (Some IMSIs are not allowed in some LAs.) This helps to facilitate the avoidance of unnecessary paging attempts. The value is sent on the BCCH. FALSE: IMSI attach not allowed TRUE: IMSI attach allowed
lAC
The Location Area Code of the external GSM cell. Note: the values 0000 and FFFE are reserved for special cases where no valid LAI exists in the MS. Old name: lAC
rAC
Routing Area Code of a routing area. An RA is used by UTRAN to page mobiles on request from the PS CN. When the parameter is changed, UTRAN shall update system information and notity UEs. Old name: rAC
t3212
Periodic update timer for LA update. Unit: 0.1 hours (= 1 decihour = 6 minutes = 360 seconds) Resolution: 1 0 means infinite time, i.e. not
cnDrxCycleLengthCs
Core Network DRX cycle length coefficient (k) for UEs in idle mode, circuit switched. The cycle length is calculated as the k'th potential of 2, where k = 6..9. For example, 6 corresponds to cycle length 640 ms, 7 corresponds to cycle length 1280 ms, etc.
cnDrxCycleLengthPs
Core Network DRX cycle length coefficient (k) for UEs in idle mode, packet switched. The cycle length is calculated as the k'th potential of 2, where k = 6..9. For example, 6 corresponds to cycle length 640 ms, 7 corresponds to cycle length 1280 ms, etc.
noOfMaxDrxCycles
Paging notification duration. To notify UEs in IDLE mode about a system information update, the RNC sends a paging message on the PCH at every page occasion of a number of maximum DRX cycles.
noOfPagingRecordTransm
System Information
Number of preconfigured subsequent transmissions of the same Paging Record. Number of MIB value tag retransmissions on the FACH. The area identity part of PLMN scope value tages for SIB1
noOfMibValueTagRetrans sib1PlmnScopeValueTag sib1RepPeriod sib3RepPeriod sib5RepPeriod sib7RepPeriod sib11RepPeriod sib12RepPeriod sib1StartPos sib3StartPos sib5StartPos sib7StartPos sib11StartPos sib12StartPos sib7ExpirationTimeFactor updateCellReattsNo
SIB7 use expiration time as re-read mechanism. The expiration time is sib7RepPeriod times sib7ExpirationTimeFactor. Number of update reattempts when an update of system information parameters in a cell failed.
UE States
Idle mode No connection to radio network (No RRC connection established) This minimizes resource utilization in UE and the network CELL_FACH mode User Equipment (UE) in Connected Mode (has an RRC Connection to radio network) UE uses the common transport channels RACH or FACH If the parameter interFreqFDDMeasIndicator = 1, the UE will evaluate cell reselection criteria on inter-frequency cells (0) CELL_DCH mode User Equipment (UE) in Connected Mode (has an RRC Connection to radio network) UE uses dedicated channels for transmitting data and signalling
Power Control
primary CPICH power should be 8 to 10% (~ 1 Watt) of the nominal RBS power at the reference point (~10W, while MCPA is 20W) The pilot power is designed to be equal in all cells at the Reference Point. primaryCpichPower = 30 dBm TopOfRack = primaryCpichPower + dlAttenuation System will adjust the TopOfRack to meet the required value. Consistency check on MaximumTransmissionPowerDL (Calculated vs. setting value) The feeder loss parameters ulAttenuation & dlAttenuation and electrical delay parameters ulElectricalDelay & dlElectricalDelay must be entered properly in the system (actual VSWR). More CPICH less capacity trade off
P-CPICH
dl/ulAttenuation dl/ElectDelay
TopOfRack MaxTxPowerDL
With increasing CPICH power capacity directly decreasis, but common channels and power per each dedicated channel is calculated from CPICH At CPICH 30 dBm, the common channel will be configured as follow:
MO Type UtranCell Pch UtranCell UtranCell Fach Fach UtranCell Rach Pch Value
-0.4 -1.8 -3.5 1.8 1.5 -3.1 -6 -7
Parameter Name primaryCpichPower pchPower primarySchPower secondarySchPower maxFach1Power maxFach2Power bchPower aichPower pichPower
Cumm(dBm)
30 29.6 28.2 26.5 31.8 31.5 26.9 24 23 38.38
Peak Power(W)
1 0.91 0.66 0.45 1.51 1.41 0.49 0.25 0.20 6.89
Typical AF
1 0.20 0.10 0.10 0.10 0.30 0.90 0.10 1.00
Avg Power(W)
1 0.18 0.07 0.04 0.15 0.42 0.44 0.03 0.20 2.53
constantValueCprach
L_PCPICH RTWP
: is the path loss estimated by the UE based on knowing the transmitted and received PCPICH power. : is the Received Total Wideband Power (uplink interference) level measured by the RBS.
constantValueCprach
: is used by the UE to calculate the initial power on the PRACH . This parameter is configurable and decides at which level below RTWP preamble ramping will start
preambleRetransMax (8) parameter determines how many times PRACH preamble can be sent within one preamble ramping cycle (SIB5&6) maxPreambleCycle (4) 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)
In average coverage conditions the RRC Connection Setup performance can be improved by tuning the open loop power control parameters These parameters are preambleRetransMax and & maxPreambleCycle powerOffsetPpm powerOffsetP0
Preamble
powerOffsetPpm
preambleRetransMax
Message part
# PRACH preambles transmitted during one PRACH cycle without receiving AICH response
maxPreambleCycle
# preamble power ramping cycles that can be done before RACH transmission failure is reported
Handover
Soft/Softer Handover Inter-Frequency Handover Inter-RAT Handover Inter-RAT Cell Change HSDPA Mobility
Intra-Frequency Handover SOFTER HANDOVER MS simultaneously connected to multiple cells (handled by same BTS) No extra transmissions across Iub interface Mobile 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 needed Mobile Evaluated HandOver (MEHO) DL/UE: MRC UL/RNC: Frame selection combining HARD HANDOVER Arises 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)
Entities Involved in Reporting, Evaluation, and Execution of Handover-Related Functions. The concept of event-triggered reporting as specified in 3GPP is used by handover evaluation and allows the UE to do some part of the evaluation. Thus, the UE is configured to evaluate and send measurement reports to the system only when certain events occur, that is, when a monitored cell is measured and the measurement result for a monitored cell fulfills certain criteria. When the conditions for triggering a certain handover are fulfilled, the handover evaluation part triggers the corresponding handover execution part.
Active Set The cells involved in soft handover and measured by the UE Virtual Active Set The Active Set associated with a non-used frequency for support of Inter-Frequency evaluation Monitored Set The cells only measured by the UE and not part of the Active Set. The monitored set can consist of intra-frequency, Inter-Frequency and Inter-RAT cells Detected Set The intra frequency cells(P-CPICH scrambling codes) detected by the UE but not part of Active Set or monitored set
Soft/Softer Handover
Event 1a, A primary CPICH enters the Reporting Range
(measured P-CPICH Ec/No) > (P-CPICH Ec/No of the Best Cell in the Active Set) reportingRange1a + hysteresis1a /2
When a P-CPICH, not included in the Active Set, enters reportingRange1a + hysteresis1a/2, and the measured value remains in reportingRange1a + hysteresis1a/2 at least a time equal to timeToTrigger1a (Time to Trigger 1a), event 1a occurs. The UE sends a MEASUREMENT REPORT message for event 1a to the SRNC. If the report contains more than one cell fulfilling 1a criteria, only the one with highest Ec/No is considered and retained. If the retained cell is a valid cell and Active Set is not full (present cells in the Active Set is less than maxActiveSet parameter), the cell is proposed to be added to the Active Set. If the Active Set is full, the cell is proposed as a replacement of the worst cell in the Active Set provided that the reported cell has a better quality than the worst cell in the Active Set.
Soft/Softer Handover
Event 1a and Event 1b
6dB
10dB
320 ms
640 ms
Soft/Softer Handover
Event 1c, A non-active primary CPICH becomes better than an Active Primary CPICH
(measured P-CPICH Ec/No) > (P-CPICH Ec/No of the Best Cell in the Active Set) + hysteresis1a /2
When a P-CPICH, not included in the Active Set, becomes stronger than the weakest P-CPICH+hysteresis1c /2 in the Active Set during a time at least equal to timeToTrigger1c,and the Active Set is full (present cells in the Active Set is equal to maxActiveSet parameter) event 1c occurs. The UE sends a MEASUREMENT REPORT message for event 1c to the SRNC. If the retained cell is a valid cell, and the Active Set is full, the cell is proposed as a replacement for the weakest cell in the Active Set
Hysteresis1c (2dB)
320 ms
Remark
3 dB 5 dB 320ms
timeToTrigger1b
timeToTrigger1c timeToTrigger1d hysteresis1a hysteresis1b hysteresis1c hysteresis1d maxActiveSet
12
11 14 0 0 2 15 3
640ms
320ms 2560ms 0 0 1dB 7dB 3
Inter-RAT Handover
Event 2d, The Estimated Quality of the Currently Used frequency is below a Certain Threshold
When the estimated quality of the current WCDMA RAN used frequency is below the absolute threshold usedFreqThresh2dEcno - hysteresis2d/2, during a time at least equal to timeToTrigger2dEcno, OR the estimated quality of the current WCDMA RAN used frequency is below the absolute threshold usedFreqThresh2dRscp - hysteresis2d/2, during a time at least equal to timeToTrigger2dRscp, event 2d occurs.
Event 2f, The estimated quality of the currently used frequency is above a certain threshold
When the estimated quality of the current WCDMA RAN used frequency is above the relative threshold usedFreqRelThresh2fEcno+usedFreqThresh2dEcno + hysteresis2f/2, during a time at least equal to timeToTrigger2fEcno, AND the estimated quality of the current WCDMA RAN used frequency is above the relative threshold usedFreqRelThresh2fRscp+usedFreqThresh2dRscp + hysteresis2f/2, during a time at least equal to timeToTrigger2fRscp event 2f occurs. The UE sends a MEASUREMENT REPORT message for event 2f to the SRNC. When SRNC receives the MEASUREMENT REPORT message for event 2f from the UE, measurements for IRATHO_eval event 3a or IFHO_eval event 2b and associated compressed mode usage is stopped.
Inter-RAT Handover
Compressed Mode and de-Compressed Mode
1 + (-12 dB)
-12 dB
640 ms
2560 ms
Inter-RAT Handover
Event 3a, The Estimated Quality of the Currently Used UTRAN Frequency is below a Certain Threshold and the Estimated Quality of the Other System is above a Certain Threshold
The event 3a occurs according to the following points: When the estimated quality of the WCDMA RAN used frequency is below the threshold usedFreqThresh2dEcno+utranRelThresh3aEcno - hysteresis3a/2 and the measured GSM carrier RSSI of a GSM/GPRS cell is above the absolute threshold gsmThresh3a, during a time at least equal to TimeToTrigger3a when the estimated quality of the WCDMA RAN used frequency is below the threshold usedFreqThresh2dRscp+utranRelThresh3aRscp - hysteresis3a/2 and the measured GSM carrier RSSI of a GSM/GPRS cell is above the absolute threshold gsmThresh3a, during a time at least equal to TimeToTrigger3a in case of the connection quality has been triggered in UL for UE TX power (event 6a, see Event 6a, The UE Tx Power becomes larger than an Absolute Threshold), the event 3a is triggered when the estimated quality of the WCDMA RAN used frequency is below the threshold usedFreqThresh2dRscp+utranRelThresh3aRscp+utranRelThreshRscp - hysteresis3a/2 and the measured GSM carrier RSSI of a GSM/GPRS cell is above the absolute threshold gsmThresh3a , during a time at least equal to TimeToTrigger3a.
Inter-RAT Handover
RSSI -95dB
320 ms
GGSN
Gn
External Networks
Gn
3G-SGSN Iu
2G-SGSN Gb
SRNC Iub
BSC Abis
RBS RBS
RBS
RBS RBS
RBS
CELL_DCH
1. DCCH (AM) Measurement Report (Event 2d) 2. Evaluation of MR 3. Compressed Mode Control 4. DCCH (AM) Measurement Control
WCDMA RAN neighbor cells are measured only when the signal strength of the GSM serving cell is above the threshold set by QSI and QSC. WCDMA RAN neighbor cells are measured only when the signal strength of the GSM serving cell is below the threshold set by QSI and QSC. WCDMA RAN neighbor cells are always measured. WCDMA RAN neighbor cells are never measured. This can be used to turn off the cell reselection/handover to WCDMA, per cell, even if COEXUMTS (parameter used to activate the functionality of making handovers and cell reselections between GSM and WCDMA) is on for the BSC.
Load sharing
Load sharing
Load sharing to 2nd carrier at RRC establishment Least loaded cell (Highest difference between power and pwradm) is chosen by sending RRC connection reject with redirection info to 2nd carrier.
by Downlink Transmitted Carrier Power* (load on source > 50% and load on target less than source by a 10 % margin) The feature is activated in an RNC by setting the parameter loadSharingRrcEnabled to TRUE f2 f2 TRUE/FALSE The attribute loadSharingCandidate specifies whether the target cell is a load-sharing neighbor of the source cell
Triggered
f1
f1
f1
f1
F2
2nd will not be redirected but may be successful or rejected due to congestion
Admission Control
WCDMA
Directed retry to GSM At call set-up - RAB Establishment for voice Triggered by Downlink Transmitted Carrier Power
The feature is activated in an RNC by setting the parameter loadSharingDirRetryEnabled to TRUE One GSM target can be defined for each WCDMA cell via the cell parameter directedRetryTarget loadSharingGsmThreshold specifies the minimum load at which offloading to GSM begins: ex 80% of pwrAdm loadSharingGsmFraction specifies the percentage of Directed Retry candidates to be diverted to GSM while the cell load is above the specified load threshold
CN
Relocation Command
Voice calls can be relocated to GSM due to high load in WCDMA If the call is not accepted in GSM - try in WCDMA again!
When GSM load reaches a customizable threshold, voice calls can be handed over to WCDMA
Dual Mode UE
GSM terminal
GSM coverage Load based handover to GSM during call set up, Directed Retry (P3) to GSM
Channel Switching
Channel Switching
Channel Switching
Channel Switching
Channel Switching
DCH
128/128
64/128
64/64
speech + 0/0
UL throughputbased upswitch coverage-triggered downswitch (DL only) choice based on UEand cell-capability
IDLE
DL throughputbased upswitch
Capacity Management
Resource request
No
Check if the requested DL Pwr + estimated Pwr > pwrAdm
15*
75*
No
Check if the requested ASE UL + estimated ASE UL > aseUlAdm
70*
Only checked if No BE-service requests Check if the requested Check if the requested DL SF + estimated DL SF ASE DL + estimated DL ASE > > No sfXAdm * aseDlAdm
No
160*
Yes, then block
X = 8 or X = 32 X = 16
240*
An existing ng user of 64/384 will be switched down to 64/128 or an existing ng user of 64/128 will be switched down to 64/64
8*
16* 32*
SRNC
Iur
3.
4.
5.
6.
HSDPA
HSPATHLOSSTHRESHOLD CQIERRORSABSENT HSPOWERMARGIN HSSCCHMAXCODEPOWER QUEUESELECTALGORITHM SUPPORTOF16QAM MAXHSRATE HSONLYBESTCELL HSHYSTERESIS1D HSQUALITYESTIMATE
HSTIMETOTRIGGER1D
MAXHSRATE
The HSDPA Iub flow control algorithm adjusts the available bit rate over Iub based mainly on the maximum possible air interface bitrate received from the scheduler, the number of users in a cell and Iub congestion indications. The RBS uses the parameter maxHsRate to determine the maximum bit rate to be used for HS-DSCH data frame traffic in one aggregated bit pipe over Iub. The parameter maxHsRate should be configured for each RBS to represent the maximum MAC-d PDU bitrate of HS-DSCH data frames, which is available for the AAL2 path or paths carrying HSDPA traffic to the RBS in question. The parameter may be set to a MAC-d PDU bit rate of 1.5 Mbps (the default value), when one dedicated physical E1 link is used for HSDPA traffic. This maximum bitrate level is the same as the bitrate expressed by the CAPACITY ALLOCATION control frames. As an example, the default value of this parameter has been obtained by multiplying the HSDPA available ATM bandwidth (excluding IMA overhead), e.g. 1.92 Mbps, with a factor of 0.79. This factor is dependent on the average number of MAC-d PDUs per HS-DSCH data frame. In this case, it is based on having 10 MAC-d PDUs (336 bits) per HS-DSCH data frame in average. It should be noted that assuming a lower number of PDUs per data frame gives a lower factor and vice versa. The parameter value of maxHsRate also depends on how the transport network is configured, e.g. if ATM VC Cross Connect is used or if AAL2 switching is used. It depends on how the ATM VCs etc are configured, e.g. for HS traffic only, sharing with AAL2 class A and B, several AAL2 paths for HS etc. Therefore it is recommended to follow the guidelines given by Ericsson regarding transport network dimensioning before setting a value for this parameter.
16QAM Modulation
The RBS hardware supports both QPSK and 16QAM modulation. However, support of 16QAM is an optional feature which can be configured on cell level using the parameter supportOf16qam. The available modulation type impacts the maximum achievable bit rate in the cell,
Maximum Achievable User Bit Rate at the RLC Level As a Function of the UE HS-DSCH Category and Modulation Type