3G Ericsson
Radio Parameter
TELKOMSEL
Prepared by Adithya Yudha
Contents
Idle Mode
 Handover
 Power Control
 Capacity Management
 Channel Switching
 HSDPA

Idle Mode and Common Channel
behavior
Cell Selection 3G part
Criteria for Cell Selection
Squel > 0 , Squal = Qqualmeas-qQualMin (only for WCDMA cells) and
Srxlev > 0 , Srxlev = Qrxlevmeas-qRxLevMin - Pcompensation (for all cells)
Pcompensation = max (maxTxPowerUl - P, 0)
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
Cell Selection 3G part
Squal > 0
Qqualmeas (dB)
(CPICH Ec/N0)
Squal >0 AND
Srxlev > 0
qQualMin
(–18)
Squal = Qqualmeas – qQualMin
qRxLevMin
(–115)
suitabl
e
cell?
Qrxlevmeas (dBm)
CPICH RSCP
Pcompensation
Pcompensation = max(maxTxPowerUl – P, 0) (dB)
Srxlev = Qrxlevmeas - qRxLevMin – Pcompensation
Srxlev > 0
Cell Reselection 3G part
First according to S criteria
Squal > 0 (only WCDMA cells)
Srxlev > 0
The cells are ranked according to the R criteria:
R(serving) = Qmeas(s) + qHyst(s)
R(neighbor) = Qmeas(n) - qOffset(s,n)
qHyst1 : Based on CPICH RSCP
qHyst(s)
qHyst2 : Based on CPICH Ec/No
qOffset1sn : Based on CPICH RSCP
qOffset(s,n)
qOffset2sn : Based on CPICH Ec/No
(1 ) qHyst(s) and qOffset(sn) based on CPICH RSCP only
qualMeasQuantity =x
(2 ) With this setting the UE first makes qHyst(s) and qOffset(sn)
based on CPICH RSCP . If a GSM cell is highest ranked, no more
ranking is done. If a WCDMA neighbor is highest ranked, a second
ranking takes place, this time according to CPICH Ec/No, and
excluding all GSM neighbors
Cell Reselection 3G part
R CRITERIA :
R(serving) = Qmeas(s) + qHyst(s)
R(neighbor) = Qmeas(n) - qOffset(s,n)
Note that parameter qOffset1sn works identically for WCDMA-GSM and
WCDMA-WCDMA neighbor relations.
But the values of GSM RSSI and WCDMA CPICH RSCP are not of the same
nature and therefore not directly comparable.
[CPICH RSCP] = [GSM RSSI] + 7
As an example a measured RSCP on a WCDMA CPICH of -100 dBm would be
comparable to a GSM broadcast channel RSSI of -93 dBm. A parameter setting
of a GSM neighbor to qOffset1sn = +7 will thus make the received signal
strength in the WCDMA and the GSM cell comparable.
Cell Reselection 3G part
MEASUREMENT ON INTRA AND INTER-RAT NEIGHBOR
The decision about when intrafrequency measurements are performed is made using the
sIntraSearch parameter in relation to Squal:
• If the Squal > sIntraSearch, the UE does not need to perform intrafrequency measurements.
• If the Squal <= sIntraSearch value, the UE performs intrafrequency measurements.
• If the sIntraSearch = 0 , is not sent to the serving cell, the UE performs intrafrequency measurements.
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)
Cell Reselection 3G part
Measurements on GSM Neighbors
available If :
CPICH Ec/No – qQualMin < SRatSearch
Rs = Serving WCDMA cell
calculation, with
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
hysteresis parameter
Rn = Neighbour WCDMA or GSM
cell calculation with offset
parameter
Yes
Rn higher in GSM cell
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
Cell re-selection to
WCDMA cell of highest
R value
RSCP
First ranking of all the cells based on
CPICH RSCP (WCDMA) and RSSI (GSM)
GSM cell measurements
RSSI
Cell Reselection 3G part
Cell Reselection 2G part
Measurements on 3G Neighbors
The parameters QSI and QSC define thresholds and also indicate whether these
measurements shall be performed when the signal strength (SS) of the serving cell is below or
above the threshold. QSI is used for idle and packet switched modes and broadcast on BCCH
and PBCCH (if enabled), while QSC is used for active mode, sent on SACCH
There are 4 different scenarios to choose from. Parameters QSI and QSC are set per GSM cell and define
both the scenario and the necessary threshold, at the same time:
• UTRAN neighboring cells are measured only when the signal strength of the GSM serving cell is above
the threshold set by QSI and QSC
• UTRAN neighbor cells are measured only when the signal strength of the GSM serving cell is below the
threshold set by QSI and QSC .
• UTRAN neighbor cells are always measured.
• UTRAN neighbor cells are never measured. This can be used to turn off the cell reselection/handover to
UMTS, per cell, even if COEXUMTS is ON for the BSC.
Value
0
1
…
6
7
8
9
10
…
14
15
dBm
-98
-94
…
-74
Always
-78
-74
-70
…
-54
Never
If RLA_C < -94 UE starts
3G measurements
UE always measures 3G
cells
If RLA_C > -70 UE starts
3G measurements
UE never measures 3G
cells
Cell Reselection 2G part
Example 1: If an UTRAN cell should serve purely to extend the coverage for MultiRAT MSs in GSM, it is logical to set QSI /QSC values from 0-6, since it's only
needed to make cell reselection and handovers to UMTS when the GSM coverage
falls low.
Cell Reselection 2G part
Example 2: If an UTRAN cell is co-sited with a GSM cell, there is a certain
correlation between signal strengths of the two systems. If the GSM is for example
using 900MHz band it is very probable that the GSM signal strength will always be
higher than the UTRAN signal, for a number of dBs. Therefore, there is no point in
measuring UTRAN cells in low GSM signal conditions and values 8-14 can be
selected accordingly.
Cell Reselection 2G part
Criteria :
CPICH Ec/No > FDDQMIN (-13dB) and
CPICH RSCP > RLA(s+n) + FDDQOFF (-infinite)
FDDQMIN
Value
0
1
2
3
4
5
6
7
dBm
-20
-19
-18
-17
-16
-15
-14
-13
FDDQOFF
Value
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
Cell Reselection 2G part
Cell Reselection List
BCCH: FDDQMIN, FDDQOFF
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
DEFAULT:
fdd cell reselect offset:
select always
(value is -infinity)
minimum fdd
threshold = -12 dB
Compare levels
of all GSM cells
to WCDMA
neighbour
Check quality
of neighbour
WCDMA cells, no
priorities between
WCDMA
neighbours
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
05.08:This may take up to 30s
FDDQOFF = -32 dB
WCDMA
cell
reselectio
n
Idle Mode Parameter Summary
Cell Selection and Reselection
accessClassNBarred
bandIndicator
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".
bcchFrequency
cellReserved
fachMeasOccaCycLenCoeff
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
Inter-frequency FDD measurement indicator.
FALSE = No
TRUE = Yes
Idle Mode Parameter Summary
maxTxPowerUl
The maximum UE transmission power on the RACH when accessing
the system. Used in UE functions for cell selection/reselection in idle
mode and connected mode. Also used by UTRAN to control the
maximum TX power level an UE may use.
If the current UE uplink transmit power is above the indicated power
value, the UE shall decrease the power to a level below the power
value. Value launched by System information (SIB11) for each intrafrequency measurement object corresponding to adjacent cells of
serving cell.
Unit: 1 dBm
Resolution: 1
-50: -50 dBm
...
33: 33 dBm
100 : Default value. The parameter is not sent in SIB11 and the UE will
use the maximum output power for this GSM cell, according to its radio
access capability.
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.
Idle Mode Parameter Summary
qHyst1
Cell reselection hysteresis used in UE functions in idle and connected
mode. Value launched by System information (SIB3).
Resolution: 2
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)
Idle Mode Parameter Summary
qRxLevMin
Used in UE functions for cell selection/reselection in idle mode and
connected mode. Minimum required (acceptable) RX level in the cell.
(dBm). Value launched by System information (SIB11) for each intrafrequency measurement object corresponding to adjacent cells of
serving cell.
Unit: 1 dBm
Resolution: 2
-115 : -115dBm
-113 : -113dBm
-111 : -111dBm
-109 : -109dBm
.....
-25 : -25 dBm
100 : Indicates that the minimum Rx 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.
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
Idle Mode Parameter Summary
sInterSearch
The decision on when measurements on inter 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
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
......
Idle Mode Parameter Summary
treSelection
Control of cell selection/reselection. Time-to-trigger for cell reselection
in seconds.
Value launched by System information (SIB3).
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
Idle Mode Parameter Summary
Location and Routing Area Updating
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
Idle Mode Parameter Summary
Paging
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
Number of preconfigured subsequent transmissions of the same
Paging Record.
System Information
noOfMibValueTagRetrans
sib1PlmnScopeValueTag
sib1RepPeriod
sib3RepPeriod
sib5RepPeriod
sib7RepPeriod
sib11RepPeriod
sib12RepPeriod
sib1StartPos
sib3StartPos
sib5StartPos
sib7StartPos
sib11StartPos
sib12StartPos
sib7ExpirationTimeFactor
updateCellReattsNo
Number of MIB value tag retransmissions on the FACH.
The area identity part of PLMN scope value tages for SIB1
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.
Idle Mode Behaviour
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
Pilot Channel Power






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
Common Control Channel Power


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:
Parameter Name
primaryCpichPower
MO Type
UtranCell
pchPower
Pch
primarySchPower
Value
Cumm(dBm)
Peak Power(W)
Typical AF
Avg Power(W)
30
1
1
1
-0.4
29.6
0.91
0.20
0.18
UtranCell
-1.8
28.2
0.66
0.10
0.07
secondarySchPower
UtranCell
-3.5
26.5
0.45
0.10
0.04
maxFach1Power
Fach
1.8
31.8
1.51
0.10
0.15
maxFach2Power
Fach
1.5
31.5
1.41
0.30
0.42
bchPower
UtranCell
-3.1
26.9
0.49
0.90
0.44
aichPower
Rach
-6
24
0.25
0.10
0.03
pichPower
Pch
-7
23
0.20
1.00
0.20
38.38
6.89

MaximumTransmissionPowerDL is design to be equal with Nominal RBS Power
2.53
Common Channel on Downlink
Cell Setup and Reconfiguration - Downlink
is the power used for transmitting the PCPICH.
is the power used for transmitting on the BCH, relative to the primaryCpichPower value.
is the power used for transmitting on the Primary SCH, relative to the primaryCpichPower value.
is the power used for transmitting on the Secondary SCH, relative to the primaryCpichPower value.
Common Transport Channel Setup and Reconfiguration - Downlink
aichPower
is the power used for transmitting on AICH, relative to the primaryCpichPower value.
maxFach1Power
defines the maximum power used for transmitting the first FACH channel, relative to the
primaryCpichPower value. The first FACH is used for logical channels BCCH, CCCH, and DCCH
control signaling.
maxFach2Power
defines the Maximum power used for transmitting the second FACH channel, relative to the
primaryCpichPower value. The second FACH is used for logical channel DTCH traffic signaling.
pOffset1Fach
is the offset between downlink DPDCH and DPCCH TFCI field on FACH.
pOffset3Fach
is the offset between downlink DPDCH and DPCCH pilot field on FACH.
pchPower
is the power used for transmitting on the PCH, relative to the primaryCpichPower value.
pichPower
is the power used for transmitting on the PICH, relative to the primaryCpichPower value.
primaryCpichPower
bchPower
primarySchPower
secondarySchPower
Common Channel on Uplink
Common Transport Channel Setup and Reconfiguration - Uplink
is a constant value in dB used by the UE to calculate the initial power on the PRACH according to
the Open Loop Power Control procedure.
powerOffsetP0
is the Power ramp step for the preamble when no acquisition indicator is received.
powerOffsetPpm
is the Power offset between the last transmitted preamble and the control part of the random
access message.
preambleRetransMax
is the maximum number of preambles sent in one RACH preamble ramping cycle.
maxPreambleCycle
is the maximum number of preamble ramping cycle.
constantValueCprach
Common Channel on Uplink
P_RACH
The initial power on the PRACH - the power of the first preamble - is determined according to equation
P_PRACH = L_PCPICH + RTWP + constantValueCprach (-27dB)
L_PCPICH
: is the path loss estimated by the UE based on knowing the
transmitted and received PCPICH power.
RTWP
: 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
Common Channel on Uplink
POWER RAMP ON RACH
To reach an appropriate received power level at the RBS, the UE uses preamble ramping. This
procedure consists of the following steps:
•
The UE transmits a preamble.
•
As soon as the RBS properly detects the preamble, it sends an Acknowledgement Indicator
(AI) on the AICH.
•
While not receiving any AI, the UE transmits a new preamble, increasing the transmission
power with respect to the previous one by the configurable parameter powerOffsetP0.(3dB)
•
As soon as the UE receives an AI, it sends the PRACH message part. The power of the
control part of the random access message is determined by the power of the last
transmitted preamble and by a configurable offset powerOffsetPpm.(- 4dB) The power of
the data part of the PRACH message is determined by the gain factors for PRACH, which is
included in System Information.
Common Channel on Uplink
POWER RAMP ON RACH

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)
Common Channel on Uplink


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
L1 ACK / AICH
Downlink Not detected
BS
MaxTXPowerUl
powerOffsetP0
Initial
preamble
power
……
Uplink
Preamble
MS Preamble
1
2
……
Preamble
preambleRetransMax
# 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
powerOffsetPpm
Message part
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.
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.
3GPP-defined UE Associated Cell sets for Measurement
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.
Event 1b, A primary CPICH leaves the Reporting Range
(measured P-CPICH Ec/No) < (P-CPICH Ec/No of the best cell in the Active Set) reportingRange1b - hysteresis1b /2
When a P-CPICH, included in the Active Set, leaves reportingRange1b - hysteresis1b /2, and the
measured value is outside reportingRange1b - hysteresis1b /2 during a time at least equal to
timeToTrigger1b, event 1b occurs. The UE sends a MEASUREMENT REPORT message for event 1b to the
SRNC. The handover algorithms will remove the reported cells one by one from the Active Set, however one
cell is always kept in the Active Set for maintaining the connection.
Soft/Softer Handover
Event 1a and Event 1b
10dB
6dB
320 ms
Cell (P_CPICH2) Would
be proposed to be
included in Active Set
List
640 ms
Cell (P_CPICH2) Would
be proposed to be
excluded from Active
Set List
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)
Cell (P_CPICH4) Would
be replaced P_CPICH3
in active set list
320 ms
Soft/Softer Handover
Parameter Summary
Setting Value
Remark
reportingRange1a
6
3 dB
reportingRange1b
10
5 dB
timeToTrigger1a
11
320ms
timeToTrigger1b
12
640ms
timeToTrigger1c
11
320ms
timeToTrigger1d
14
2560ms
hysteresis1a
0
0
hysteresis1b
0
0
hysteresis1c
2
1dB
hysteresis1d
15
7dB
maxActiveSet
3
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
UE stop compressed
mode
1 + (-12 dB)
-12 dB
640 ms
UE start compressed
mode to measure GSM
or Interfreq Neighbors
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
(-12 dB) + (-1dB)
RSSI -95dB
320 ms
IFHO & IRAT Parameter Summary
WCDMA to GPRS (PS)
Gi
External
Networks
GGSN
Gn
Gn
3G-SGSN
2G-SGSN
Gb
Iu
SRNC
BSC
Abis
Iub
RBS
RBS
RBS
RBS
RBS
RBS
A successful IRATCC from
WCDMA to GPRS
SRNC
CN/SGSN
CELL_DCH
1. DCCH (AM) ”Measurement Report” (Event 2d)
2. Evaluation of MR
3. Compressed Mode Control
4. DCCH (AM) ”Measurement Control”
5. DCCH (AM) ”Measurement Report” (Event 3a)
6. Evaluation of MR
7. DCCH (AM):CELL_DCH Cell Change Order from UTRAN
8. GSM: RA Update
9. ”SRNS Context Request”
10. Stop DL Transmission
11. ”SRNS Context Response”
12. ”Iu Release Command”
13. Dedicated Radio Link Release
14. ”Iu Release Complete”
Target BSS
GSM to WCDMA (voice) :
Measurements on WCDMA Cells
Four different scenarios:

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.
• Directed Retry to GSM at RAB establishment
When Dl power reaches ‘loadSharingGsmThreshold’ percentage of
pwradm, calls are targeted to be offloaded to GSM. This is achieved
by rejecting RAB establishment requests with ‘directed retry’ as a
cause.
Load sharing capabilities
available in the WCDMA RAN
Inter-Frequency Load Sharing

* Not operator configurable
Inter-Frequency Load Sharing
 At
call set-up - RRC Connection Establishment for all
RABs
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
Inter-Frequency Load Sharing
(RRC redirection) (Extra Slide)
RNC
Idle
Mode
”RRC Connection Request” CCCH/RACH
F1
”RRC Connection Reject” CCCH/FACH
Cell selection
on designated
UTRA carrier
”RRC Connection Request” CCCH/RACH
F2
”RRC Connection Setup” CCCH/FACH
Includes ‘Frequency
Info’ IE
2nd will not be
redirected but may
be successful or
rejected due to
congestion
Directed retry to GSM
Applicable for voice in P3
GSM
Admission
Control
WCDMA
Directed retry to GSM

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
Directed Retry to GSM
UE
RBS/RNC
CN
RAB Assignment Request
Directed Retry
decision to send
RAB Assignment Response (failed, cause=directed retry)
Relocation Required
Contacts GSM
cell and orders
relocation
HO from UTRAN command
Relocation Command
Successful
access to GSM
Iu release Command
Iu release Complete
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!
Load balancing for voice between
WCDMA-GSM
Features
Introduction
& Roadmap
When out of coverage, the
WCDMA voice call is handed
over to GSM
When GSM load reaches a
customizable threshold, voice calls can
be handed over to WCDMA
WCDMA coverage
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 Parameter Summary
Channel Switching
1. Common to Dedicated Evaluation
Monitors if the UE shall be switched from a common to a dedicated transport
channel due to large amount of user data buffered in the RNC or the UE.
2. Dedicated to Dedicated Up-Switch Evaluation
Monitors if the throughput becomes close to the max user bandwidth and switch to
the next higher bitrate radio bearer is required.
2a. Dedicated to Dedicated Coverage triggered Down-Switch Evaluation
Monitors if a switch to a lower rate radio bearer is required due to coverage.
3. Dedicated to Common Evaluation
Monitors if a switch from a Cell_DCH to Cell_FACH is required due to a decrease
in transmitted user data.
4. Common to Idle Evaluation
Monitors if a switch from Cell_FACH to Idle mode is required due to a complete
lack of user data transmission.
Channel Switching
Multi-RAB Down-switch Evaluation
Monitors if a release (or downswitch) of PS I/B RAB shall be initiated due to lack of
PS data throughput (zero), resulting in a single speech 12.2 kbps (or speech + PS
0/0) or CS64 RAB.
Multi-RAB Up-switch Evaluation
Monitors if an upswitch from multi-RAB SP0 to multi-RAB SP64 shall be initiated
due to data buffered in either RNC or UE.
Channel Switching
Future
releases
stand-alone interactive RAB
speech + interactive
RAB
HS
speech
+ 384/HS
384/HS
DCH
64/384
speech
+ 64/HS
128/128
64/HS
speech
+ 64/64
64/128
speech
+ 0/0
64/64
Low/No throughput
Measurement for down
Switch timer period
FACH
Low/No RLC buffer load for
Inactivity timer period
IDLE
PS RAB Establishment
UL throughputbased upswitch
activity/inactivity-based
switching UL and/or DL
coverage-triggered
downswitch (DL only)
DL throughputbased upswitch
choice based on UEand cell-capability
Capacity Management
Admission control workflow
Resource request
* Current
default values
Yes,
then
block
Is admission blocked
by Congestion Control?
No, then
accept
Yes, then block
No
Check if the requested +
estimated # compressed mode RL
>
compModeAdm
15*
75*
No
Yes,
then
block
No
Check if the requested
code usage + estimated code usage
>
dLCodeAdm
70*
Check if the requested
ASE UL + estimated ASE UL
>
aseUlAdm
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
Yes,
then
SF8adm= 8* block
SF16adm= 16*
SF32adm= 32*
Yes,
then
block
Check if the requested
DL Pwr + estimated Pwr
>
pwrAdm
•X = 8 or X = 32
•X = 16
240*
160*
Yes,
then
block
Yes,
then
block
Soft Congestion mechanism
New request for ng 64/128, ng 64/64 or g access
Admission Control blocks the new request
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
Spreading Factor (SF) limits
used in Admission Control
8*
* Current default values
16*
32*
ASE release order
Core Network
Iu
Iu
SRNC &
DRNC
SRNC
Iur
over Iu:
over Iur:
1.
Non-guaranteed service
class connections
2.
Non-guaranteed service
class connections
3.
CS/streaming service
class connections
4.
CS /streaming service
class connections
5.
Speech users
6.
Speech users
HSDPA
HSDPA Parameter Summary
Parameter Name
Default Value
HSPATHLOSSTHRESHOLD
170
170
10
10
2
2
-20
-20
CQIERRORSABSENT
HSPOWERMARGIN
HSSCCHMAXCODEPOWER
QUEUESELECTALGORITHM
SUPPORTOF16QAM
Initial Setting TELKOMSEL
ROUND_ROBIN
FALSE
ROUND_ROBIN
TRUE
MAXHSRATE
15
30
HSONLYBESTCELL
1
1
HSHYSTERESIS1D
10
10
HSQUALITYESTIMATE
HSTIMETOTRIGGER1D
CPICH_RSCP
640
CPICH_RSCP
640
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