Table of ContentsChapter 1 Power Control.....................................................................................
List of FiguresFigure 1.2Power control configuration model (1)...............................................................
List of TablesTable 1.1NEs required for power control........................................................................
Chapter 1 Power Control1.1 Summary of Updates          This section provides the update history of this manual and introdu...
        DL power balance: It is used to reduce the downlink power drifting of a given                  UE during soft han...
Abbreviation                             Full SpellingDPB                   Downlink Power BalanceDPCCH                 De...
1.3 Availability1.3.1 Involved Network Element         1.3.1 shows the Network Elements (NEs) required for power control. ...
1.4 Impact1.4.1 On System Performance         Power control improves the system capacity and ensures the QoS.1.4.2 On Othe...
RNC                                        RadioClass       GlobalParaClass               RAB&SRBClass            CellClas...
CELLCAC.Class                                        FRC.Class Max UL TX power of conversational service                  ...
PICHPWROFFSET                                     PRACHBASIC.Class                                                      PR...
TYPRAB.Class                                    BCH.Class                 TYPRABBASIC.Class                               ...
beginning of a connection.I. Uplink Open-Loop Power Control 1)     Uplink Open-Loop Power Control on PRACH The PRACH rando...
1   Initial Power Calculation for the First PreambleTo determine the initial power of the UE on its first PRACH preamble t...
Parameter name             PCPICH transmit power    Parameter ID               PCPICHPOWER    GUI range                  -...
Parameter name           Constant value for calculating initial TX power    Parameter ID             CONSTANTVALUE    GUI ...
Parameter name            AICH transmission timing Parameter ID              AICHTXTIMING GUI range                 0–1 Ph...
Recommendation:If the value of POWER INCREASE STEP is too big, the access process will beshortened, but the probability of...
Parameter name             Max preamble loop Parameter ID               MMAX GUI range                  1–32 Physical rang...
Parameter name            Random back-off lower limitParameter ID              NB01MINGUI range                 0–50Physic...
Caution:In order to change the value of the RANDOM BACK-OFF LOWER LIMIT orRANDOM BACK-OFF UPPER LIMIT parameter, if the cu...
Recommendation:    It is recommended that the value of POWER OFFSET corresponding to the TFC    for signaling transmission...
Parameter name            Gain Factor BetaD Parameter ID              GAINFACTORBETAD GUI range                 1–15 Physi...
When setting up the first DPCCH, the UE shall start the UL inner loop power controlat a power level and set the initial po...
Description:    This parameter is used by the RNC to compute the DPCCH power offset which is    used by the UE to calculat...
In addition, there are four parameters (MAX UL TX POWER OF CONVERSATIONALSERVICE, MAX UL TX POWER OF STREAMING SERVICE, MA...
Parameter name             Max UL TX power of interactive serviceParameter ID               MAXULTXPOWERFORINTGUI range   ...
2     Rate MatchingThe purposes of rate matching are as follows:      To enable a CCTrCH to multiplex data bits from mult...
Parameter name            DL rate matching attribute Parameter ID              DLRATEMATCHINGATTR GUI range               ...
Typical Services                    ULRATEMATCHI   DLRATEMATCHI                                                   NGATTR  ...
3     Power Difference Between DPCCH And DPDCHThe uplink DPCCH and DPDCH(s) are transmitted on different codes. In order t...
Parameter name             Reference BetaD Parameter ID               BETAD GUI range                  1–15 Physical range...
Typical Services                             β c,ref : β d,ref 32kbps Streaming                                   9:15 16k...
reference values to be used are those belonging to the radio bearer whose maximumrate TF has the highest bit rate of the r...
Caution:In order to change the value of the DL POWER CONTROL MODE 1 parameterthrough MOD CELLSETUP, the cell shall be firs...
Parameter name          RRC Proc DPDCH PC preamble lengthParameter ID            RRCPROCPCPREAMBLEGUI range               ...
Parameter name                        HHO Proc DPDCH PC preamble length  Parameter ID                          HHOPROCPCPR...
power is allocated to the PCPICH, P-SCH, S-SCH, P-CCPCH, S-CCPCH, AICH, andPICH channels.As mentioned previously, the P-CP...
Recommendation:These two parameters (PSCH TRANSMIT POWER and SSCH TRANSMITPOWER) can be adjusted through measurement in th...
Parameter name              Max transmit power of FACH Parameter ID                MAXFACHPOWER GUI range                 ...
Parameter name                         PCH powerParameter ID                           PCHPOWERGUI range                  ...
Recommendation: The default value of the AICH POWER OFFSET parameter is -6, namely -6 dB. An appropriate transmit power va...
DCH                                   RACH reports the measured value                                                     ...
 Note:    In Huawei implementation, α in the above formula is set to 0.    Ptotal is the carrier power measured at the ...
3     Upper and Lower Limits of DL DPDCH PowerThe downlink dedicated traffic channel is limited by an upper and lower limi...
Configuration Rule and Restriction:    The parameters RL MAX DL TX POWER and RL MIN DL TX POWER must verify    the followi...
radio link specific, which are identical for all TFC in the TFCS, whereas for the uplinkthe gain factors are TFC-dependent...
Parameter name             Pilot power offset          Parameter ID               PILOTPO          GUI range              ...
    If the estimated SIR is greater than the SIR target, the NodeB sends a TPC     command “down” to the UE on the downli...
TPC command “up”, where the “up” command means TPC = 1 and the “down”command means TPC = 0.When the UE receives the TPC, U...
Parameter name            UL closed loop power control step size    Parameter ID              ULTPCSTEPSIZE    GUI range  ...
It means that the UE will receive more than one TPC in each slot, but all the TPCs arethe same from each cell which belong...
- TPC_cmd = γ (W1, W2, … WN), where TPC_cmd can take the values 1 or -1.The function γ shall fulfill the following criteri...
TPC_cmd is set to -1 if any of TPC_temp1 to TPC_tempN are equal to -1.                                          N         ...
The UE shall check the downlink power control mode (DPC_MODE) before the TPCcommand is generated:      If DPC_MODE = 0,  ...
Upon receiving the TPC commands, the UTRAN shall adjust its downlinkDPCCH/DPDCH power accordingly.    If DPC_MODE = 0, th...
Parameter name                 Power control algorithm switch Parameter ID                   INNER_LOOP_DL_LMTED_PWR_INC_S...
Caution:In order to change the value of the POWER INCREASE LIMIT parameter throughMOD CELLSETUP, the cell shall be firstly...
Caution:         In order to change the value of the DL POWER WINDOW AVERAGE SIZE         parameter through MOD CELLSETUP,...
level required by the service bearer through adjustment of the SIR target. This control acts on each DCH belonging to the ...
Parameter name            Power control algorithm switch    Parameter ID              OLPC_SWITCH    GUI range            ...
Wcdma power control
Wcdma power control
Wcdma power control
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Wcdma power control
Wcdma power control
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Wcdma power control

  1. 1. Table of ContentsChapter 1 Power Control..............................................................................................................1 Huawei Technologies Proprietary i
  2. 2. List of FiguresFigure 1.2Power control configuration model (1)........................................................................6Figure 1.3Power control configuration model (2)........................................................................7Figure 1.4Power control configuration model (3)........................................................................7Figure 1.5Power control configuration model (4)........................................................................7Figure 1.6Power control configuration model (5)........................................................................8Figure 1.7Power control configuration model (6)........................................................................8Figure 1.8Power control configuration model (7)........................................................................9Figure 1.9Power control configuration model (8)........................................................................9Figure 1.10PRACH preamble and message parts......................................................................10Figure 1.11Uplink open-loop power control on PRACH............................................................11Figure 1.12Downlink open-loop power control on the DPDCH................................................40Figure 1.13Uplink inner-loop power control...............................................................................46Figure 1.14Downlink inner-loop power control..........................................................................51Figure 1.15Uplink outer-loop power control procedure............................................................57Figure 1.16Downlink power balance...........................................................................................66 Huawei Technologies Proprietary ii
  3. 3. List of TablesTable 1.1NEs required for power control......................................................................................4Table 1.2Product versions.............................................................................................................4Table 15.1Outer-loop Power Control Parameters on RAB basis..............................................65Table 16.1Commands for the reconfiguration on the RNC side...............................................71 Huawei Technologies Proprietary iii
  4. 4. Chapter 1 Power Control1.1 Summary of Updates This section provides the update history of this manual and introduces the contents of subsequent updates. Manual Version Description 01 (2006-9-26) Modified the principles to adjust SIR target in case of multi- service. 02 (2006-9-28) Add description to the Rate Matching.1.2 Introduction The WCDMA system is a self-interfered system. The most important way to restrain system interference level is the power control, especially in the uplink direction. Without power control, a single overpowered UE could block a whole cell.1.2.1 Definition The power control is performed by the UE or UTRAN to adjust and control the power of transmit signals according to the changes of channel environment and the quality of receive signals. In the WCDMA system, the power control mechanism comprises the following parts:  Open-loop power control: Applicable in UL and DL. It sets the initial uplink and downlink transmit power. Open-loop power control is used on physical channels such as PRACH, DPCH.  Inner-loop power control: Applicable in UL and DL. It directly adjusts the uplink and downlink transmit power using power control commands. The inner loop power control is performed by each UE and NodeB with the frequency of 1500 times per second (1.5 kHz).  Outer-loop power control: Applicable in UL and DL. It indirectly controls the uplink and downlink transmit power by increasing or decreasing the target SIR value. Huawei Technologies Proprietary 1
  5. 5.  DL power balance: It is used to reduce the downlink power drifting of a given UE during soft handover.1.2.2 Purpose The purpose of power control is to adjust the uplink and downlink power to the minimum while ensuring the QoS.  In the uplink, if a UE near the NodeB has too large a transmit power, it may cause great interference to other UEs on the edge of the cell or even block the whole cell. This is called near-far effect. In that case, uplink power control is needed.  In the downlink, the system capacity is determined by the total required code power for each connection. Therefore, it is necessary to keep the transmit power at the lowest level while ensuring signal quality at the receiving end for each UE. In that case, the downlink power control is needed.  Power control can be used against shadow fading and fast fading.  Power control can increase system capacity.  Power control for power drifting can improve the soft handover performance in the downlink.1.2.3 Terms and Abbreviations I. Terms None. II. Abbreviations Abbreviation Full Spelling 3GPP 3rd Generation Partnership Project AMR Adaptive MultiRate BER Bit Error Rate BLER Block Error Rate CDMA Code Division Multiple Access CPCH Common Packet Channel CPICH Common Pilot Channel DCH Dedicated Channel DL Downlink Huawei Technologies Proprietary 2
  6. 6. Abbreviation Full SpellingDPB Downlink Power BalanceDPCCH Dedicated Physical Control ChannelDPCH Dedicated Physical ChannelDPDCH Dedicated Physical Data ChannelFDD Frequency Division DuplexFER Frame Error RateLMT Local Maintenance TerminalMML Man-Machine LanguageMRC Maximum Ratio CombiningOLPC Outer-Loop Power ControlPCA Power Control AlgorithmP-CPICH Primary Common Pilot ChannelPRACH Physical Random Access ChannelRAN Radio Access NetworkRNC Radio Network ControllerRRC Radio Resource ControlRSCP Received Signal Code PowerRTWP Received Total Wideband PowerSHO Soft HandoverSIR Signal-Interference RatioSRNC Serving RNCTFCI Transport Format Combination IndicatorTPC Transmit Power ControlUE User EquipmentUL UplinkUMTS Universal Mobile Telecommunications SystemUTRAN UMTS Terrestrial Radio Access NetworkUu Uu InterfaceWCDMA Wideband CDMA Huawei Technologies Proprietary 3
  7. 7. 1.3 Availability1.3.1 Involved Network Element 1.3.1 shows the Network Elements (NEs) required for power control. Table 1.1NEs required for power control UE NodeB RNC MSC Server MGW SGSN GGSN HLR √ √ √ - - - - - Note:  - = NE not required  √ = NE required1.3.2 Software Release 1.3.2 describes the versions of the HUAWEI UMTS RAN products that support power control. Table 1.2Product versions Product Version RNC BSC6800 V100R002 and later releases NodeB DBS3800 V100R006 and later releases BTS3812A V100R002 and later releases BTS3812E V100R002 and later releases1.3.3 Miscellaneous None. Huawei Technologies Proprietary 4
  8. 8. 1.4 Impact1.4.1 On System Performance Power control improves the system capacity and ensures the QoS.1.4.2 On Other Features None.1.5 Restrictions None.1.6 Technical Description Power control in the uplink and the downlink is different. UL power control and DL power control are separately described.1.6.1 Power Control Configuration Model The configuration model for power control is as show in 1.6.1, 1.6.1, 1.6.1, 1.6.1, 1.6.1, 1.6.1, 1.6.1 and 1.6.1. Huawei Technologies Proprietary 5
  9. 9. RNC RadioClass GlobalParaClass RAB&SRBClass CellClass FRC.Class PSCH.Class CELL.Class CORRMALGOSWITCH.Class SSCH.Class PCPICH.Class OLPC.Class BCH.Class PRACHBASIC.Class DPB.Class FACH.Class PRACHUUPARAS.Class TYPRABBASIC.Class SCCPCH.Class AICH.Class TYPRAB.Class CHPWROFFSET.Class RACH.Class TYPSRBBASIC.Class AICHPWROFFSET.Class PRACHTFC.Class TYPSRB.Class PICHPWROFFSET.Class CELLCAC.Class TYPSRBOLPC.Class CELLRLPWR.Class CELLSETUP.Class TYPRABOLPC.Class CELLOLPC.Class TYPSRBSEMISTATICTF.Class TYPRABSEMISTATICTF.ClassFigure 1.2Power control configuration model (1) Huawei Technologies Proprietary 6
  10. 10. CELLCAC.Class FRC.Class Max UL TX power of conversational service TFCI power offset Max UL TX power of streaming service TPC power offset Max UL TX power of interactive service Pilot power offset Max UL TX power of background service Power control algorithm selection RRC Proc DPDCH PC preamble length UL closed loop power control step size RRC Proc SRB delay DL power control mode HHO Proc DPDCH PC preamble length FDD DL power control step size HHO Proc SRB delay Constant value configured by default Initial power offset for SHOFigure 1.3Power control configuration model (2) CELLRLPWR.Class RACH.Clsass RL Max DL TX power Max preamble loop RL Min DL TX power Random back-off lower limit Random back-off upper limitFigure 1.4Power control configuration model (3) PRACHTFC.Class CELLSETUP.Clsass Power offset Power increase limit ADD PRACHTFC DL power window average size Gain Factor BetaD DL power control mode 1Figure 1.5Power control configuration model (4) Huawei Technologies Proprietary 7
  11. 11. PICHPWROFFSET PRACHBASIC.Class PRACHUUPARAS.Class CHPWROFFSET.Class AICHPWROFFSET.Class Power increase step Max preamble retransmission AICH power offset Constant value for calculating initial TX power PICH power offsetFigure 1.6Power control configuration model (5) TYPRABOLPC.Class DPB.Class TYPSRBOLPC.Class DPB measurement report period DPB measurement filter coefficient BLER target value DPB triggering threshold SIR adjustment step DPB stop threshold Maximum SIR increase step Ratio for max power Maximum SIR decrease step DPB adjustment ratio Maximum SIR target DPB adjustment period Minimum SIR target Max DPB adjustment step Figure 1.7Power control configuration model (6) Huawei Technologies Proprietary 8
  12. 12. TYPRAB.Class BCH.Class TYPRABBASIC.Class PSCH.Class TYPSRB.Class PCPICH.Class TYPSRBBASIC.Class CELL.Class Reference BetaC Reference BetaD PCPICH transmit power AICH.Class PSCH transmit power AICH transmission timing BCH transmit power TYPRABSEMISTATICTF.Class TYPSRBSEMISTATICTF.Class UL rate matching attribute DL rate matching attribute Figure 1.8Power control configuration model (7) SSCH CELL.Class FACH.Class SSCH transmit power PCH.Class SCCPCH.Class CELLSELRESEL.Class PCH power Max allowed UE UL TX power Max transmit power of FACH CORRMALGOSWITCH.Class Power control algorithm switch OLPC.Class CELLOLPC.Class TYPSRBOLPC.Class SIR init target value SIR measurement filter coefficient OLPC adjustment period SIR adjustment coefficientFigure 1.9Power control configuration model (8)1.6.2 Open-Loop Power Control Based on the measurement acquirement of receive power, open-loop power control attempts to make a rough estimation of path loss by means of a downlink signal, and then to provide a coarse initial power setting of the UE and the NodeB at the Huawei Technologies Proprietary 9
  13. 13. beginning of a connection.I. Uplink Open-Loop Power Control 1) Uplink Open-Loop Power Control on PRACH The PRACH random access process is comprised of two different parts that the UE will send to the system: preamble part and message part. AICH access slots RX at UE One access slot Acq. Ind. τ PRACH access slots TX at UE p-a Pre- Pre- amble amble Message part τp-p τp-m Figure 1.10PRACH preamble and message parts The preamble part is at the length of 4096 chips and consists of 256 repetitions of a signature that is 16–chip long. There are a maximum of 16 signatures available. The message part is 10 or 20 ms long and is comprised of a control part and a data part. The data and control parts are transmitted in parallel. Once the UE receives an answer on the corresponding AICH, it will send the message part of the PRACH. Therefore, the parameters related to the UE access on the PRACH involve three parts:  Initial power calculation for the first preamble  Power ramping for preamble retransmission  Power setting for message part Huawei Technologies Proprietary 10
  14. 14. 1 Initial Power Calculation for the First PreambleTo determine the initial power of the UE on its first PRACH preamble transmission,both UE and UTRAN are involved, as shown in 1. BCH : •CPICH channel power • UL interference level RACH •Measure CPICH_RSCP •Determine the initial transmitted powerFigure 1.11Uplink open-loop power control on PRACHPrior to PRACH transmission, the UE shall acquire the System Information Block(SIB) that includes "Primary CPICH Tx power", “UL interference”, and “Constantvalue”.The UE measures the value for the CPICH_RSCP and calculates the initial power forthe first PRACH preamble with the following formula:Preamble_Initial_Power (PRACH) = PCPICH TRANSMIT POWER - CPICH_RSCP +UL interference + CONSTANT VALUE FOR CALCULATING INITIAL TX POWERWhere: The PCPICH TRANSMIT POWER parameter defines the PCPICH transmit power in a cell. It is broadcast in SIB 5. Huawei Technologies Proprietary 11
  15. 15. Parameter name PCPICH transmit power Parameter ID PCPICHPOWER GUI range -100–500 Physical range& unit -10–50, step: 0.1 (dBm) Default value 330 Optional / Optional Mandatory MML command ADD PCPICH/ MOD CELL Description: This parameter should be set based on the actual system environment such as cell coverage (radius) and geographical environment. For the cells to be covered, the downlink coverage should be guaranteed as a premise. For the cells requiring soft handover area, this parameter should satisfy the proportion of soft handover areas stipulated in the network planning. If the maximum transmit power of the PCPICH is configured too great, the cell capacity will be decreased because a lot of system resources will be occupied and the interference with the downlink traffic channels will be increased. Recommendation: PCPICH TRANSMIT POWER is related to the downlink coverage in the network planning. The default setting is 330, namely 33 dBm. If this parameter is too small, it will influence directly the downlink pilot coverage range; if it is too big, the downlink interference will increase, and the transmit power that can be distributed to the services will be reduced, which will affect the downlink capacity. Meanwhile, the configuration of this parameter also has influence on the distribution of handover areas. CPICH_RSCP is the received signal code power, the received power on one code measured on the primary CPICH. It is measured by the UE. UL interference is the UL RTWP measured by the NodeB, including noise generated in the receiver, within the bandwidth defined by the receiver pulse shaping filter. It is broadcast in SIB 7. The CONSTANT VALUE FOR CALCULATING INITIAL TX POWER parameter compensates for the RACH processing gain. It is broadcast in SIB 5. Huawei Technologies Proprietary 12
  16. 16. Parameter name Constant value for calculating initial TX power Parameter ID CONSTANTVALUE GUI range -35–-10. Physical range& unit dB Default value -20 Optional / Mandatory Optional MML command ADD PRACHBASIC/MOD PRACHUUPARAS Description: It is used to calculate the transmit power of the first preamble in the random access process.2 Power Ramping for Preamble RetransmissionIf no positive or negative acquisition indicator on AICH is received by the UE from thenetwork after a given period, then the UE shall increase the preamble power byPOWER INCREASE STEP so that the Node-B can detect it, and re-send thepreamble. This “ramping up” process is characterized below: AICH transmission timing: In order to avoid too many collisions and consider the processing capability of NodeB, it is specified in 3GPP that a UE shall wait at least 3 or 4 access slots between the transmissions of 2 consecutive preambles, according to the parameter AICH TRANSMISSION TIMING. Power increment step: Each time the UE re-transmits a preamble, the transmit power is increased by POWER INCREASE STEP, compared to the previous transmitted preamble. Maximum number of transmitted preambles: This limitation is defined by MAX PREAMBLE RETRANSMISSION and MAX PREAMBLE LOOP parameters. MAX PREAMBLE RETRANSMISSION defines the maximum number of transmitted preambles allowed within an access cycle, and MAX PREAMBLE LOOP defines the maximum number of random access preamble cycles. An access cycle is defined by a number of radio frames on which the PRACH access (and therefore a preamble ramping cycle) is allowed on specific slot numbers. Huawei Technologies Proprietary 13
  17. 17. Parameter name AICH transmission timing Parameter ID AICHTXTIMING GUI range 0–1 Physical range& unit None Default value 1 Optional / Mandatory Optional MML command ADD AICH Description: The transmission timing information of an AICH. "0" indicates that there are 7680 chips offset between the access preamble of the PRACH and AICH; "1" indicates that there are 12800 chips offset between them. Caution:In order to change the value of the AICH TRANSMISSION TIMING parameter, thecell shall be firstly de-activated through DEA CELL.After the old configuration of AICH is deleted through RMV AICH, a new AICH can beestablished through ADD AICH. Parameter name Power increase step Parameter ID POWERRAMPSTEP GUI range 1–8 Physical range& unit dB Default value 2 Optional / Mandatory Optional MML command ADD PRACHBASIC/MOD PRACHUUPARAS Description: The power increase step of the random access preambles transmitted before the UE receives the acquisition indicator in the random access process. Huawei Technologies Proprietary 14
  18. 18. Recommendation:If the value of POWER INCREASE STEP is too big, the access process will beshortened, but the probability of wasting power will be bigger; if it is too small, theaccess process will be lengthened, but transmitting power will be saved. It is avalue to be weighed.Parameter name Max preamble retransmissionParameter ID PREAMBLERETRANSMAXGUI range 1–64Physical range& unit NoneDefault value 20Optional / Mandatory OptionalMML command ADD PRACHBASIC/MOD PRACHUUPARASDescription:The maximum number of preambles transmitted in a preamble ramping cycle.Recommendation:The product of the MAX PREAMBLE RETRANSMISSION parameter and theabove-mentioned PRACH POWER INCREASE STEP determines the maximumramp power of the UE within a preamble ramp cycle.If this value is too small, the preamble power may fail to ramp to the requiredvalue, resulting in UE access failure; if it is too big, the UE may repeatedly increasethe power and make access attempts, resulting in interference to other users. Huawei Technologies Proprietary 15
  19. 19. Parameter name Max preamble loop Parameter ID MMAX GUI range 1–32 Physical range& unit None Default value 8 Optional / Mandatory Optional MML command ADD RACH/MOD RACH Description: The maximum number of random access preamble loops. Caution:In order to change the value of the MAX PREAMBLE LOOP parameter, if the currentcell is on-going and there is one and only one PRACH in this cell, the cell shall befirstly de-activated through DEA CELL.The ramping process stops until the number of transmitted preambles has reachedthe MAX PREAMBLE RETRANSMISSION within an access cycle, or when themaximum number of access cycles MAX PREAMBLE LOOP is reached.When a negative acquisition indicator on AICH is received by the UE, which indicatesrejection of the preamble, the UE shall wait for a certain back-off delay and re-initiatea new random access process. Two parameters RANDOM BACK-OFF LOWERLIMIT and RANDOM BACK-OFF UPPER LIMIT are defined respectively as the lowerand upper bounds of the random access back-off delay. Huawei Technologies Proprietary 16
  20. 20. Parameter name Random back-off lower limitParameter ID NB01MINGUI range 0–50Physical range& unit NoneDefault value 0Optional / Mandatory OptionalMML command ADD RACH/MOD RACHDescription:The lower limit of random access back-off delay.Parameter name Random back-off upper limitParameter ID NB01MAXGUI range 0–50Physical range& unit NoneDefault value 0Optional / Mandatory OptionalMML command ADD RACH/MOD RACHDescription:The upper limit of random access back-off delay.Configuration Rule and Restriction:RANDOM BACK-OFF LOWER LIMIT shall not be set bigger than RANDOMBACK-OFF UPPER LIMIT.If RANDOM BACK-OFF LOWER LIMIT = RANDOM BACK-OFF UPPER LIMIT, itmeans that the retransmission periodicity of preamble part is fixed. Huawei Technologies Proprietary 17
  21. 21. Caution:In order to change the value of the RANDOM BACK-OFF LOWER LIMIT orRANDOM BACK-OFF UPPER LIMIT parameter, if the current cell is on-going andthere is one and only one PRACH in this cell, the cell shall be firstly de-activatedthrough DEA CELL.3 Power Setting for Message PartWhen the UE has received a positive acquisition indicator on AICH, it will transmit therandom access message using three or four uplink access slots after the uplinkaccess slot of the last transmitted preamble, depending on the AICH transmissiontiming parameter. This message is made up of a control part and a data part: Control part: The transmit power of the control part of the random access message should be POWER OFFSET higher than the power of the last transmitted preamble. Parameter name Power offset Parameter ID POWEROFFSETPPM GUI range -5–10 Physical range& unit dB Default value Values according to PRACH TFC Optional / Mandatory Mandatory MML command ADD PRACHTFC Description: The power offset between the last access preamble and the message control part. The power of the message control part can be obtained by adding the offset to the access preamble power. Configuration Rule and Restriction: POWER OFFSET must be set for each instance of PRACH TFC. Huawei Technologies Proprietary 18
  22. 22. Recommendation: It is recommended that the value of POWER OFFSET corresponding to the TFC for signaling transmission is set to -3 dB, and that corresponding to the TFC for service transmission is set to -2 dB. If the value of POWER OFFSET is set too low, it is likely that the signaling or the service data carried over the RACH can not be correctly received, which affects the uplink coverage. If the value is set too high, the uplink interference is increased, and the uplink capacity is affected. Caution:In order to change the value of the POWER OFFSET parameter, if the current cell ison-going and there is one and only one PRACH in this cell, the cell shall be firstly de-activated through DEA CELL. Data part: The message part of the uplink PRACH channel employs gain factors to control the control/data part: a) GAIN FACTOR BETAC (βc) is the gain factor for the control part. b) GAIN FACTOR BETAD (βd) is the gain factor for the data part. Parameter name Gain Factor BetaC Parameter ID GAINFACTORBETAC GUI range 1–15 Physical range& unit None Default value None Optional / Mandatory Mandatory MML command ADD PRACHTFC Description: The power occupancy factor of the control part. Huawei Technologies Proprietary 19
  23. 23. Parameter name Gain Factor BetaD Parameter ID GAINFACTORBETAD GUI range 1–15 Physical range& unit None Default value None Optional / Optional Mandatory MML command ADD PRACHTFC Description: The power occupancy factor of the data part. PRACH CTFC POWER OFFSET GAIN FACTOR GAIN FACTOR BETAC BETAD 0 -3 13 15 1 -2 10 15 Configuration Rule and Restriction: Either Gain Factor BetaC or Gain Factor BetaD must be set to 15 for each instance of power difference between control and data part of PRACH. Caution:In order to change the value of the GAIN FACTOR BETAC or GAIN FACTORBETAD parameter, if the current cell is on-going and there is one and only onePRACH in this cell, the cell shall be firstly de-activated through DEA CELL.2) Uplink Open-Loop Power Control on DPCCHThe UL open-loop power control on dedicated channel aims to determine the initialpower of the first uplink DPCCH. Huawei Technologies Proprietary 20
  24. 24. When setting up the first DPCCH, the UE shall start the UL inner loop power controlat a power level and set the initial power of uplink DPCCH with the following formula:DPCCH_Initial_Power = DPCCH_Power_Offset - CPICH_RSCPWhere: CPICH_RSCP is the received signal code power, the received power on one code measured on the primary CPICH. It is a measurement performed by the UE. DPCCH_Power_Offset is provided by the RNC to the UE via RRC signaling in the “Uplink power control info” IE or in the “Uplink power control info short” IE. These IEs are included in the RRC messages of the radio bearer setup, reconfiguration and release, transport channel and physical channel reconfiguration, RRC connection setup and re-establishment and in the handover to UTRAN command. For Huawei, DPCCH_Power_Offset is calculated with the following formula:DPCCH_Power_Offset = PCPICH TRANSMIT POWER + UL interference +CONSTANT VALUE CONFIGURED BY DEFAULT Where: The PCPICH TRANSMIT POWER parameter defines the PCPICH transmit power in a cell. UL interference is the UL RTWP measured by the NodeB. The CONSTANT VALUE CONFIGURED BY DEFAULT parameter reflects the target Ec/No of the uplink DPCCH preamble. Parameter name Constant value configured by default Parameter ID DEFAULTCONSTANTVALUE GUI range -35–-10 Physical range& unit dB Default value -27 Optional / Optional Mandatory MML command SET FRC Huawei Technologies Proprietary 21
  25. 25. Description: This parameter is used by the RNC to compute the DPCCH power offset which is used by the UE to calculate the initial transmit power of UL DPCCH during the open loop power control process.1 Maximum Allowed UL Transmit PowerThe maximum allowed UL transmit power defines the total maximum output powerallowed for the UE and depends on the desired type of service. The information willbe transmitted on the FACH, mapped on the S-CCPCH, to the UE in the RADIOBEARER SETUP message of the RRC protocol during the call setup.For Huawei, the MAX ALLOWED UE UL TX POWER parameter is the maximumtransmit power of the PRACH channel when the UE tries to access to the specifiedcell. Parameter name Max allowed UE UL TX power Parameter ID MAXALLOWEDULTXPOWER GUI range -50–33 Physical range& unit dBm Default value 24 Optional / Optional Mandatory MML command ADD CELLSELRESEL; MOD CELLSELRESEL Description: The maximum allowed uplink power transmitted on RACH of a UE in the cell, which is related to the network planning. Configuration Rule and Restriction: If the value of MAX ALLOWED UE UL TX POWER is higher than the UE capability, the maximum transmission power is of course limited by the UE capability. The transmission power on the PRACH for preamble part and message part cannot be higher than the MAX ALLOWED UE UL TX POWER parameter. Huawei Technologies Proprietary 22
  26. 26. In addition, there are four parameters (MAX UL TX POWER OF CONVERSATIONALSERVICE, MAX UL TX POWER OF STREAMING SERVICE, MAX UL TX POWEROF INTERACTIVE SERVICE and MAX UL TX POWER OF BACKGROUNDSERVICE) which correspond to the maximum allowed transmit power of four classesof services: conversational, streaming, interactive and background respectively. Parameter name Max UL TX power of conversational service Parameter ID MAXULTXPOWERFORCONV GUI range -50–33 Physical range& unit dBm Default value 24 Optional / Optional Mandatory MML command ADD CELLCAC; MOD CELLCAC Description: The maximum UL transmit power for conversational service in a specific cell. It is based on the UL coverage requirement of the conversational service designed by the network planning. Parameter name Max UL TX power of streaming service Parameter ID MAXULTXPOWERFORSTR GUI range -50–33 Physical range& unit dBm Default value 24 Optional / Mandatory Optional MML command ADD CELLCAC; MOD CELLCAC Description: The maximum UL transmit power for streaming service in a specific cell. It is based on the UL coverage requirement of the streaming service designed by the network planning. Huawei Technologies Proprietary 23
  27. 27. Parameter name Max UL TX power of interactive serviceParameter ID MAXULTXPOWERFORINTGUI range -50–33Physical range& unit dBmDefault value 24Optional / Mandatory OptionalMML command ADD CELLCAC; MOD CELLCACDescription:The maximum UL transmit power for interactive service in a specific cell. It isbased on the UL coverage requirement of the interactive service designed by thenetwork planning.Parameter name Max UL TX power of background serviceParameter ID MAXULTXPOWERFORBACGUI range -50–33Physical range& unit dBmDefault value 24Optional / Mandatory OptionalMML command ADD CELLCAC; MOD CELLCACDescription:The maximum UL transmit power for background service in a specific cell. It isbased on the UL coverage requirement of the background service designed by thenetwork planning.Recommendation:The above four parameters define the maximum uplink transmit power whentransmitting the services in a cell.The bigger these parameters are, the wider the coverage of the correspondingservices will be. When the downlink coverage is exceeded, the uplink coverageand downlink coverage of the service will become unbalanced. If these parametersare too small, the uplink coverage will probably be smaller than the downlinkcoverage of the service. If there is no special requirement, use the default value. Huawei Technologies Proprietary 24
  28. 28. 2 Rate MatchingThe purposes of rate matching are as follows: To enable a CCTrCH to multiplex data bits from multiple traffic sub-flows, the system matches traffic rates to physical channel rates. To meet the different QoS requirements of various services, the system adjusts the coding redundancy degree of each channel. It is equivalent to changing the bit energy (Eb) of each channel and balancing the power among different channels. This method improves power usage and reduces interference. The higher the service QoS requirement is, the higher the corresponding RMA value. According to the RMA value of each traffic channel, the rate matching mechanism repeats more bits of the services with higher QoS requirements. Comparatively, it repeats less, even deletes some bits of the services with lower QoS requirement. Thus, it meets different QoS requirements through adjusting the bit redundancy degree of each transport channel. Parameter name UL rate matching attribute Parameter ID ULRATEMATCHINGATTR GUI range 1–256 Physical range& unit None Default value Values according to SRB and RAB Optional / Mandatory Mandatory MML command ADD TYPSRBSEMISTATICTF/ MOD TYPSRBSEMISTATICTF/ ADD TYPRABSEMISTATICTF/ MOD TYPRABSEMISTATICTF/ Description: Rate matching attribute (RMA) is a semi-static parameter provided by the upper layer for each traffic channel according to QoS. It represents the weight of processing (repeating or deleting) data bits on the corresponding transport channel during rate matching. This parameter is valid in the case of multiplexing of transport channel, that is, when multiple transport channels are combined into a CCTrCH. It is used to compare with the RMA values of other multiplexing transport channels. Huawei Technologies Proprietary 25
  29. 29. Parameter name DL rate matching attribute Parameter ID DLRATEMATCHINGATTR GUI range 1–256 Physical range& unit None Default value Values according to SRB and RAB Optional / Mandatory Mandatory MML command ADD TYPSRBSEMISTATICTF/ MOD TYPSRBSEMISTATICTF/ ADD TYPRABSEMISTATICTF/ MOD TYPRABSEMISTATICTF/ Description: Rate matching attribute (RMA) is a semi-static parameter provided by the upper layer for each traffic channel according to QoS. It represents the weight of processing (repeating or deleting) data bits on the corresponding transport channel during rate matching. This parameter is valid in the case of multiplexing of transport channel, that is, when multiple transport channels are combined into a CCTrCH. It is used to compare with the RMA values of other multiplexing transport channels.Rate matching attribute parameters are defined per RAB in the following table: Typical Services ULRATEMATCHI DLRATEMATCHI NGATTR NGATTR CS Domain RAB 12.2bps AMR 137:130:161 137:130:161 64kbps Conversational / Unknown 110 110 56kbps Conversational / Unknown 100 100 32kbps Conversational / Unknown 100 100 28.8kbps Conversational / Unknown 100 100 57.6kbps Streaming 100 100 Huawei Technologies Proprietary 26
  30. 30. Typical Services ULRATEMATCHI DLRATEMATCHI NGATTR NGATTR PS Domain RAB64kbps Conversational / Unknown 100 10032kbps Conversational / Unknown 100 10016kbps Conversational / Unknown 120 1208kbps Conversational / Unknown 140 140256kbps Streaming 100 100144kbps Streaming 100 100128kbps Streaming 100 10064kbps Streaming 100 10032kbps Streaming 100 10016kbps Streaming 120 1208kbps Streaming 140 140384kbps Background 100 100256kbps Background 100 100144kbps Background 100 100128kbps Background 100 10064kbps Background 100 10032kbps Background 100 10016kbps Background 120 1208 kbps Background 140 140384kbps Interactive 100 100256kbps Interactive 100 100144kbps Interactive 100 100128kbps Interactive 100 10064kbps Interactive 100 10032kbps Interactive 100 10016kbps Interactive 120 1208 kbps Interactive 140 140 Signaling RB3.4kbps SRB 180 18013.6kbps SRB 180 180 Huawei Technologies Proprietary 27
  31. 31. 3 Power Difference Between DPCCH And DPDCHThe uplink DPCCH and DPDCH(s) are transmitted on different codes. In order tomeet a given QoS requirement on the transport channels whatever the transportformat they use, various power differences between DPDCH and DPCCH are definedthrough gain factors, called βc for DPCCH and βd for DPDCH.There are two ways of controlling the gain factors of the DPCCH code and theDPDCH codes for different TFCs in normal (non-compressed) frames:− βc and βd are signalled for the TFC, or− βc and βd is computed for the TFC, based on the signalled settings for areference TFC.3GPP allows combinations of these two methods to be used to associate βc and βdvalues with all TFCs in the TFCS. These two methods are described in subsections5.1.2.5.2 and 5.1.2.5.3 respectively of TS25.214. Several reference TFCs may besignaled from higher layers.For Huawei, a mix of these techniques is effectively applied, which requires the RNCto compute and signal all TFC offsets when required. The RNC computes a newpower offset for each required TFC dynamically using a single set of configurablereference values (corresponding to parameters Reference BetaC and ReferenceBetaD) stored for each pre-defined RABs or SRBs. This computed TFC specific offsetis then signaled to the UE. Parameter name Reference BetaC Parameter ID BETAC GUI range 1–15 Physical range& unit None Default value Values according to SRB and RAB Optional / Mandatory Mandatory MML command ADD TYPSRBBASIC/MOD TYPSRB/ADD TYPRABBASIC/MOD TYPRAB Description: Power occupation ratio of the control part of reference TFC. Huawei Technologies Proprietary 28
  32. 32. Parameter name Reference BetaD Parameter ID BETAD GUI range 1–15 Physical range& unit None Default value Values according to SRB and RAB Optional / Mandatory Mandatory MML command ADD TYPSRBBASIC/MOD TYPSRB/ADD TYPRABBASIC/ MOD TYPRAB Description: Power occupation ratio of the data part of reference TFC.UL reference power offset parameters (βc,ref and βd,ref) are defined in the followingtable: Typical Services β c,ref : β d,ref CS Domain RAB 12.2bps AMR 12:15 64kbps Conversational / Unknown 6:15 56kbps Conversational / Unknown 6:15 32kbps Conversational / Unknown 9:15 28.8kbps Conversational / Unknown 13:15 57.6kbps Streaming 7:15 PS Domain RAB 64kbps Conversational / Unknown 7:15 32kbps Conversational / Unknown 9:15 16kbps Conversational / Unknown 14:15 8kbps Conversational / Unknown 15:11 256kbps Streaming 4:15 144kbps Streaming 5:15 128kbps Streaming 5:15 64kbps Streaming 7:15 Huawei Technologies Proprietary 29
  33. 33. Typical Services β c,ref : β d,ref 32kbps Streaming 9:15 16kbps Streaming 14:15 8kbps Streaming 15:11 384kbps Background 4:15 256kbps Background 4:15 144kbps Background 5:15 128kbps Background 5:15 64kbps Background 7:15 32kbps Background 9:15 16kbps Background 14:15 8 kbps Background 15:11 384kbps Interactive 4:15 256kbps Interactive 4:15 144kbps Interactive 5:15 128kbps Interactive 5:15 64kbps Interactive 7:15 32kbps Interactive 9:15 16kbps Interactive 14:15 8 kbps Interactive 15:11 Signaling RB 3.4kbps SRB 15:12 13.6kbps SRB 12:15 Configuration Rule and Restriction: Either Reference BetaC or Reference BetaD must be set to 15 for each instance of UL reference power offset.The gain factors (βc and βd) are computed for certain TFCs, based on the settings fora reference TFC with the formula defined in subsection 5.1.2.5.3 of TS25.214.In Huawei implementation, in the case of RAB combination, the radio bearer specific Huawei Technologies Proprietary 30
  34. 34. reference values to be used are those belonging to the radio bearer whose maximumrate TF has the highest bit rate of the radio bearers being combined. For example, forthe combination of the 3.4 kbps SRB service, 384 kbps background service, and 12.2kbps AMR service, the reference power offset values applied are those belonging tothe maximum rate TF (12x336) of 384 kbps background radio bearer.4 First Radio Link EstablishmentWhen commanded by higher layers, the TPC commands sent on a downlink radio linkfrom NodeBs that have not yet achieved uplink synchronization will follow a pattern asfollows:If the radio link is part of the first radio link set sent to the UE and if the value "n"obtained from the parameter DL POWER CONTROL MODE 1 is different from 0,then: The TPC pattern shall consist of n instances of the pair of TPC commands ("0", "1"), followed by one instance of TPC command "1", where ("0","1") indicates the TPC commands to be transmitted in two consecutive slots. The TPC pattern continuously repeat but shall be forcibly re-started at the beginning of each frame where CFN mod 4 = 0.In addition, The TPC pattern shall consist of only TPC commands "1". The TPC pattern shall terminate when uplink synchronization is achieved. Parameter name DL power control mode 1 Parameter ID DLTPCPATTERN01COUNT GUI range 0–30 Physical range& unit None Default value 10 Optional / Mandatory Optional MML command ADD CELLSETUP/MOD CELLSETUP Description: DL transmit power control (TPC) mode of the first radio link set before completion of UL synchronization. Huawei Technologies Proprietary 31
  35. 35. Caution:In order to change the value of the DL POWER CONTROL MODE 1 parameterthrough MOD CELLSETUP, the cell shall be firstly de-activated through DEA CELL.5 Transmit Power Control in the UL DPCCH Power Control PreambleAn uplink DPCCH Power Control Preamble (PC Preamble) is a period of uplinkDPCCH transmission prior to the start of the uplink DPDCH transmission in order toensure that the inner loop power control has converged when the transmission of thedata bits begins. It consists of a given number of DPCCH slots transmitted prior to thedata transmission on DPDCH. The RNC transmits the PC Preamble parameter(number of DPCCH preamble slots) in the “Uplink DPCH power control info” IE usingthe RRC signaling.In addition to the PC Preamble delay, the mobile will not send any data on signalingradio bearers during the number of frames indicated in the “SRB delay” IE, sentthrough RRC signaling in the “Uplink DPCH power control info” IE.Considering the application scenarios, different values for PC Preamble and SRBdelay parameters are configured. In the case of RRC connection establishment, PC Preamble and SRB delay are respectively defined by parameters RRC PROC DPDCH PC PREAMBLE LENGTH and RRC PROC SRB DELAY. In the case of hard handover, PC Preamble and SRB delay are respectively defined by parameters HHO PROC DPDCH PC PREAMBLE LENGTH and HHO PROC SRB DELAY. Huawei Technologies Proprietary 32
  36. 36. Parameter name RRC Proc DPDCH PC preamble lengthParameter ID RRCPROCPCPREAMBLEGUI range 0–7Physical range& unit FrameDefault value 0Optional / Mandatory OptionalMML command ADD CELLCAC/MOD CELLCACDescription:DPDCH power control preamble length in DCH RRC process.Parameter name RRC Proc SRB delayParameter ID RRCPROCSRBDELAYGUI range 0–7Physical range& unit FrameDefault value 7Optional / Mandatory OptionalMML command ADD CELLCAC/MOD CELLCACDescription:Delay of SRB in DCH RRC process. Huawei Technologies Proprietary 33
  37. 37. Parameter name HHO Proc DPDCH PC preamble length Parameter ID HHOPROCPCPREAMBLE GUI range 0–7 Physical range& unit Frame Default value 0 Optional / Mandatory Optional MML command ADD CELLCAC/MOD CELLCAC Description: DPDCH power control preamble length in DCH HHO process. Parameter name HHO Proc SRB delay Parameter ID HHOPROCSRBDELAY GUI range 0–7 Physical range& unit Frame. Default value 7 Optional / Mandatory Optional MML command ADD CELLCAC/MOD CELLCAC Description: Delay of SRB in DCH HHO process. Inner loop power control is thus applied on the DPCCH only, in a first time, starting from the initial DPCCH transmit power determined by the open loop power control process. Then, once PC Preamble DPCCH slots have been transmitted and SRB delay slots passed, data starts to be transmitted on the DPDCH at an initial transmit power deduced from the current DPCCH transmit power and DPDCH/DPCCH power difference (using βc and βd gain factors).II. Downlink Open-Loop Power Control 1) Downlink Open-Loop Power Control on Common Channel For the common channels, DL open-loop power control is to determine how much Huawei Technologies Proprietary 34
  38. 38. power is allocated to the PCPICH, P-SCH, S-SCH, P-CCPCH, S-CCPCH, AICH, andPICH channels.As mentioned previously, the P-CPICH power is defined by the PCPICH TRANSMITPOWER parameter as an absolute value in dBm. The power of all other commonchannels is defined in relation with the PCPICH TRANSMIT POWER parameter.The following tables describe which parameter is used to determine the power foreach common channel: Parameter name PSCH transmit power Parameter ID PSCHPOWER GUI range -350–150 Physical range& unit -35–15, step: 0.1 (dB) Default value -50 Optional / Mandatory Optional MML command ADD PSCH/MOD CELL Description: The offset of the PSCH transmit power from the PCPICH transmit power in a cell. Parameter name SSCH transmit power Parameter ID SSCHPOWER GUI range -350–150 Physical range& unit -35–15, step: 0.1(dB) Default value -50 Optional / Mandatory Optional MML command ADD SSCH/MOD CELL Description: The offset of the SSCH transmit power from the PCPICH transmit power in a cell Huawei Technologies Proprietary 35
  39. 39. Recommendation:These two parameters (PSCH TRANSMIT POWER and SSCH TRANSMITPOWER) can be adjusted through measurement in the actual environment so thatthe transmit powers of the synchronization channels just satisfy the UE receivingdemodulation requirement. Specifically, when UEs receive signals at differentlocations within the range of the cell, the transmit power should be just enough toensure that the UE can implement fast synchronization in most areas at the vergeof the cell. Neither P-SCH nor S-SCH has come through channel code spectrumspread, so they produce more serious interference than other channels do,especially for near–end users. Therefore, the value should not be too big.Parameter name BCH transmit powerParameter ID BCHPOWERGUI range -350–150Physical range& unit -35–15, step: 0.1(dB)Default value -20Optional / Mandatory OptionalMML command ADD BCH/MOD CELLDescription:The offset of the BCH transmit power from the PCPICH transmit power in a cell.Recommendation:The BCH TRANSMIT POWER parameter can be adjusted and optimized throughmeasurement in the actual environment. When UEs receive signals at differentlocations within the range of the cell, the transmit power should be just enough toensure the correct demodulation of the information carried on the channel in mostareas at the verge of the cell. This setting of this parameter should not be too big,so as to avoid unnecessary waste of the transmit power.If the setting of this parameter is too small, the user at the verge of the cell will failto receive the system information correctly, and the downlink common channelcoverage will be influenced, which will affect cell coverage; if the setting is too big,other channels will be interfered, the power resources will be occupied, andconsequently the cell capacity will be influenced. Huawei Technologies Proprietary 36
  40. 40. Parameter name Max transmit power of FACH Parameter ID MAXFACHPOWER GUI range -350–150 Physical range& unit -35–15, step: 0.1(dB) Default value 10 Optional / Optional Mandatory MML command ADD FACH/MOD SCCPCH Description: The offset between the FACH transmit power and PCPICH transmit power in a cell. Recommendation: Set the maximum FACH transmit power to an appropriate value that is just enough to ensure the target BLER. If the setting of this parameter is too small, the UE at the cell verge will fail to receive correctly the services and signaling borne over the FACH, resulting in influence on the downlink common channel coverage and the cell coverage; if it is too big, other channels will be interfered, the power resources will be occupied, and consequently the cell capacity will be influenced. Caution:In order to change the value of the MAX TRANSMIT POWER OF FACH parameter ifthe current cell is on-going and there is one and only one SCCPCH in this cell, or inorder to change the configuration of the SCCPCH with the smaller SCCPCH ID whenthere are two SCCPCHs in this cell, the cell shall be firstly de-activated through DEACELL. Huawei Technologies Proprietary 37
  41. 41. Parameter name PCH powerParameter ID PCHPOWERGUI range -350–150Physical range& unit -35–15, step: 0.1(dB)Default value -20Optional / Mandatory OptionalMML command ADD PCH/MOD SCCPCHDescription:The offset between the PCH transmit power and PCPICH transmit power in a cell.Recommendation:The default value of the PCH POWER parameter is -20, namely -2 dB.If this parameter is too small, the UE at the cell verge will fail to receive pagingmessages correctly, and this will influence downlink common channel coverageand cell coverage; if it is too big, other channels will be interfered, the downlinktransmit power will be occupied, and consequently the cell capacity will beinfluenced.Parameter name AICH power offsetParameter ID AICHPOWEROFFSETGUI range -22–5Physical range& unit dBDefault value -6Optional / Mandatory OptionalMML command ADD CHPWROFFSET/MOD AICHPWROFFSETDescription:The difference between the transmit power of AICH and that of PCPICH. Huawei Technologies Proprietary 38
  42. 42. Recommendation: The default value of the AICH POWER OFFSET parameter is -6, namely -6 dB. An appropriate transmit power value should be set for AICH to ensure that all users at cell verge can receive the access indication. However, to avoid waste of the power, the setting of the transmit power should not be too big. Parameter name PICH power offset Parameter ID PICHPOWEROFFSET GUI range -10–5 Physical range& unit dB Default value -7 Optional / Mandatory Optional MML command ADD CHPWROFFSET/MOD PICHPWROFFSET Description: The difference between the transmit power of PICH and that of PCPICH. Recommendation: The default value of the PICH POWER OFFSET parameter is -7, namely -7 dB. If this parameter is too small, the UE at the cell verge will fail to receive paging messages correctly, which will probably result in mis–operation in reading PCH channel and waste of the UE battery and affect the downlink common channel coverage and the cell coverage; if it is too big, other channels will be interfered, the power resources will be occupied, and consequently the cell capacity will be influenced.2) Downlink Open-Loop Power Control on Dedicated Channel (DPDCH)The aim of the DL open-loop power control on DPDCH is to determine the transmitpower of the traffic (dedicated) channel based on the downlink measurement report ofthe UE. Both UE and UTRAN shall take part in downlink open-loop power control onthe DPDCH, as shown in 2. Huawei Technologies Proprietary 39
  43. 43. DCH RACH reports the measured value Measure CPICH Ec/N0 Determine the downlink initial power controlFigure 1.12Downlink open-loop power control on the DPDCHThe following gives a formula to calculate the initial power of the DPDCH when atraffic (dedicated) channel is set up:   R Eb  P Pinitial = × ( ) DL ×  CPICH − αPTotal  W N0  Ec   ( ) CPICH   N0 Where: R is the requested data bit rate by the user. W is the chip rate. (Eb / N0) DL is the Eb/No target to ensure the service quality. In Huawei implementation, RNC searches for a value of Eb/No target dynamically using a set of pre-defined values corresponding to the specific cell environment type, code type, coding rate and BLER target. For detailed information, refer to the Load Control. (Ec/N0)CPICH is the ratio of received energy per chip to noise spectral density of CPICH received by UE. α is the orthogonality factor in the downlink. In the WCDMA system, orthogonal codes are employed in the downlink to separate the users, and without any multi- path propagation on the orthogonality remains when the Node B signal is received by the mobile station. However, if there is sufficient delay spread in the radio channel, part of the base station signals will be regarded as multiple access interference by the mobile station. The orthogonality of 1 corresponds to perfectly orthogonal users. Huawei Technologies Proprietary 40
  44. 44.  Note: In Huawei implementation, α in the above formula is set to 0. Ptotal is the carrier power measured at the NodeB and reported to the RNC.1 Radio Link Reconfiguration Power SettingWhen reconfiguring a radio link, the new physical channel may not have the samepower as the previous one (because of different SF, and so on). It is not specified,however, in 3GPP protocol that the RNC can send a new initial power for the newconfiguration in the RADIO_LINK_RECONFIGURATION_PREPARE message, whichprovides the NodeBs with the new physical/transport channel configuration.Thus, the NodeB will adjust the downlink power through the process of inner-looppower control.2 Initial Power Setting In Soft HandoverIn order to prevent a waste of downlink power while adding a new leg in the activeset, a new adjustment for power of the new leg is used. Based on the abovecalculation as used for the initial power of the DPDCH when a traffic (dedicated)channel is set up, the power required by a new leg introduced in the active set shallbe decreased by an offset, which is defined by the INITIAL POWER OFFSET FORSHO parameter. Parameter name Initial power offset for SHO Parameter ID SHOINITPWRPO GUI range 0–25 Physical range& unit dB Default value 15 Optional / Mandatory Optional MML command ADD CELLCAC/MOD CELLCAC Description: Initial DL power offset for a new added RL in SRNC. Huawei Technologies Proprietary 41
  45. 45. 3 Upper and Lower Limits of DL DPDCH PowerThe downlink dedicated traffic channel is limited by an upper and lower limit for eachradio link. This limitation is set through the RL MAX DL TX POWER and RL MIN DLTX POWER parameters. Both parameters are provided a value for the different datarate of radio access bearers. So they correspond to a set of values rather than asingle value. Parameter name RL Max DL TX power Parameter ID RLMAXDLPWR GUI range -350–150 Physical range& unit -35–15; step: 0.1(dB) Default value Values according to data rate of RABs Optional / Mandatory Mandatory MML command ADD CELLRLPWR/MOD CELLRLPWR Description: The maximum downlink transmit power of radio link. This parameter should fulfill the coverage requirement of the network planning, and the value is relative to PCPICH transmit power. Parameter name RL Min DL TX power Parameter ID RLMINDLPWR GUI range -350–150 Physical range& unit -35–15; step: 0.1(dB) Default value Values according to data rate of RABs Optional / Mandatory Mandatory MML command ADD CELLRLPWR/MOD CELLRLPWR Description: The minimum downlink transmit power of radio link. This parameter should consider the maximum downlink transmit power and the dynamic range of power control, and the value is relative to PCPICH transmit power. Huawei Technologies Proprietary 42
  46. 46. Configuration Rule and Restriction: The parameters RL MAX DL TX POWER and RL MIN DL TX POWER must verify the following relationship: RL MIN DL TX POWER ≤RL MAX DL TX POWER Typical Services RL MAX DL TX POWER RL MIN DL TX POWER CS Domain RAB 12.2bps -30 -180 28.8kbps -20 -170 32kbps -20 -170 57.6kbps -10 -160 64kbps 30 -120 PS Domain RAB 384kbps 40 -110 256kbps 20 -170 144kbps 0 -150 128kbps 0 -150 64kbps -20 -170 32kbps -40 -190 16kbps -60 -210 8kbps -80 -2304 Power Difference between DPCCH and DPDCHFor the downlink DPCH, the relative transmit power offset between DPCCH fields andDPDCHs is determined by the network. The TFCI, TPC and pilot fields of the DPCCHare offsets related to the power of DPDCHs by PO1, PO2, and PO3 dB respectively.The power offsets PO1, PO2 and PO3 are defined by the TFCI POWER OFFSET,TPC POWER OFFSET, and PILOT POWER OFFSET parameters respectively.These power offsets cannot be reconfigured during the connection. These offsets are Huawei Technologies Proprietary 43
  47. 47. radio link specific, which are identical for all TFC in the TFCS, whereas for the uplinkthe gain factors are TFC-dependent. Parameter name TFCI power offset Parameter ID TFCIPO GUI range 0–24 Physical range& unit 0–6; step: 0.25(dB) Default value 0 Optional / Optional Mandatory MML command SET FRC Description: The offset of TFCI bit transmit power from data bit transmit power in each time slot of radio frames on DL DPCH. Parameter name TPC power offset Parameter ID TPCPO GUI range 0–24 Physical range& unit 0–6; step: 0.25(dB) Default value 12 Optional / Mandatory Optional MML command SET FRC Description: The offset of TPC bit transmit power from data bit transmit power in each time slot of radio frames on DL DPCH. Huawei Technologies Proprietary 44
  48. 48. Parameter name Pilot power offset Parameter ID PILOTPO GUI range 0–24 Physical range& unit 0–6; step: 0.25(dB) Default value 12 Optional / Mandatory Optional MML command SET FRC Description: The offset of pilot bit transmit power from data bit transmit power in each time slot of radio frames on DL DPCH. The downlink transmit power control procedure controls simultaneously the power of a DPCCH and its corresponding DPDCHs. The power control loop adjusts the power of the DPCCH and DPDCHs with the same amount, that is to say, the relative power difference between the DPCCH and the DPDCHs is not changed.1.6.3 Inner-Loop Power Control Inner-loop power control is also called fast closed-loop power control. It controls the transmit power according to the information returned from the peer physical layer. The UE and the NodeB can adjust the transmit power according to the RX SIR of the peer end, to compensate the fading of radio links. Inner-loop power control consists of uplink inner-loop power control and downlink inner-loop power control, and they work separately. I. Uplink Inner-Loop Power Control Uplink inner-loop power control is used to control the power of the uplink radio links. In fact, uplink inner-loop power control is executed on the DPCCH, and related DPDCH transmit power is calculated from DPCCH transmit power according to DPDCH/DPCCH power ratio (βd /βc). For details, refer to 1.6.2“Open-Loop Power Control”. The RNC sends the SIR target to the NodeB and then the NodeB compares the estimated SIR with the SIR target of uplink DPCCH pilot symbol once every timeslot. Huawei Technologies Proprietary 45
  49. 49.  If the estimated SIR is greater than the SIR target, the NodeB sends a TPC command “down” to the UE on the downlink DPCCH TPC field. Otherwise, the NodeB sends a TPC command "Up". Note: The "Up" command means TPC = 1 and the "Down" command means TPC = 0. For the SIR = RSCP / ISCP * SF , The Received Signal Code Power (RSCP) is unbiased measurement of the received power on one code. The Interference Signal Code Power (ISCP) is the interference on the received signal, and SF=the spreading factor used on the DPCCH.SIR estimation andcompare with SIR target TPC 1500 HzSIR target NodeB UEFigure 1.13Uplink inner-loop power controlThe following describes the uplink inner-loop power control:1 Single Radio LinkIt means that the UE will receive only one TPC in each slot. The NodeB will estimatethe SIR value and sends TPC to the UE according to the comparison between SIRtarget and SIR estimated result.If the estimated SIR is greater than the SIR target, the NodeB sends a TPC command“down” to the UE on the downlink DPCCH TPC field. Otherwise, the NodeB sends a Huawei Technologies Proprietary 46
  50. 50. TPC command “up”, where the “up” command means TPC = 1 and the “down”command means TPC = 0.When the UE receives the TPC, UE will adjust uplink transmit power according to thePower Control Algorithm (PCA).There are two types of inner-loop PCA algorithm: PCA1 and PCA2. The RNCconfigures the PCA algorithm based on the POWER CONTROL ALGORITHMSELECTION parameter. Parameter name Power control algorithm selection Parameter ID PWRCTRLALG GUI range ALGORITHM1, ALGORITHM2. Physical range& unit None Default value ALGORITHM1 Optional / Mandatory Optional MML command SET FRC Description: This parameter is used to inform the UE of the method for translating the received Transmit Power Control (TPC) commands. In other words, it is used to select UL power control algorithm. Configuration Rule and Restriction: Huawei sets the POWER CONTROL ALGORITHM SELECTION parameter to algorithm1 as default value for all power control configurationsPCA1: UE adjusts uplink transmit power for each slot; the step of PCA1 should be1dB or 2dB by UL CLOSED LOOP POWER CONTROL STEP SIZE parameter. Huawei Technologies Proprietary 47
  51. 51. Parameter name UL closed loop power control step size Parameter ID ULTPCSTEPSIZE GUI range 1–2 Physical range& unit dB Default value 1 Optional / Mandatory Optional MML command SET FRC Description: The step size of the closed loop power control performed on UL DPCCH. This parameter is mandatory when the parameter [Power control algorithm selection] is set as "ALGORITHM1".The following table lists the TPC command corresponding to the specific TPC atPCA1 algorithm: TPC TPC_cmd 0 -1 1 1PCA2: The UE adjusts the uplink transmit power for each 5-slot cycle and the step is1 dB fixedly.The following table lists the TPC command corresponding to the specific TPC atPCA2 algorithm: TPC TPC_cmd 0,0,0,0,0 0,0,0,0,-1 1,1,1,1,1 0,0,0,0,1 Else 0,0,0,0,02 Softer Handover Huawei Technologies Proprietary 48
  52. 52. It means that the UE will receive more than one TPC in each slot, but all the TPCs arethe same from each cell which belongs to one NodeB.The UE will combine the DL TPC by Maximum Ratio Combining (MRC) algorithm.Therefore, other processing is the same as that in scenario1 (single radio link).3 Soft handoverIt means that the UE will receive more than one TPC in each slot, and all the TPCscome from different NodeBs.On the NodeB side, there are two phases to process power control during the softhandover procedure: Uplink synchronization phase: The NodeB should send durative TPC=1 to newly-added radio link before successful synchronization. Multi-radio link phase: Each NodeB and each cell will estimate the SIR individually and the general TPC individually. Therefore, the UE may receive different TPC from different RLS.On the UE side, the UE will receive different TPCs from different RLS at the sametime. Therefore, the UE should combine all the TPCs which come from differentNodeBs to get TPC commands and adjust uplink transmit power according to thecombined TPC commands.There is different UE TPC combination algorithm for PCA1 and PCA2. In case of PCA1First, the UE shall conduct a soft symbol decision Wi on each of the power controlcommands TPCi, where i = 1, 2, …, N (N is greater than 1 and is the number of TPCcommands from radio links of different radio link sets.) That may be the result of a firstphase of combination.Finally, the UE derives a combined TPC command, TPC_cmd, as a function γ of allthe N soft symbol decisions Wi: Huawei Technologies Proprietary 49
  53. 53. - TPC_cmd = γ (W1, W2, … WN), where TPC_cmd can take the values 1 or -1.The function γ shall fulfill the following criteria:If the N TPCi commands are random and uncorrelated, with equal probability of beingtransmitted as "0" or "1", the probability that the output of γ is equal to 1 shall begreater than or equal to 1/(2N), and the probability that the output of γ is equal to -1shall be greater than or equal to 0.5. Further, the output of γ shall equal 1 if the TPCcommands from all the radio link sets are reliably “1”, and the output of γ shall equal-1 if a TPC command from any of the radio link sets is reliably “0”.Then, after deriving a combined TPC_cmd, the UE will adjust uplink transmit poweras pre-defined power step which is configured by the RNC. In case of PCA2The UE shall make a hard decision on the value of each TPCi, where i = 1, 2, …, N (Nis the number of TPC commands from radio links of different radio link sets.) Thatmay be the result of a first phase of combination.The UE shall follow this procedure for 5 consecutive slots, resulting in N harddecisions for each of the 5 slots. The sets of 5 slots shall be aligned to the frameboundaries and there shall be no overlap between each set of 5 slots.The value of TPC_cmd is zero for the first 4 slots. After 5 slots have elapsed, the UEshall determine the value of TPC_cmd for the fifth slot in the following way:The UE first determines one temporary TPC command, TPC_temp i, for each of the Nsets of 5 TPC commands as follows:- If all 5 hard decisions within a set are "1", TPC_tempi = 1.- If all 5 hard decisions within a set are "0", TPC_tempi = -1.- Otherwise, TPC_tempi = 0.Finally, the UE derives a combined TPC command for the fifth slot, TPC_cmd, as afunction γ of all N temporary power control commands TPC_tempi:TPC_cmd (5th slot) = γ (TPC_temp1, TPC_temp2, …, TPC_tempN), where TPC_cmd(5th slot) can take the values 1, 0 or –1, and γ is given by the following definition: Huawei Technologies Proprietary 50
  54. 54. TPC_cmd is set to -1 if any of TPC_temp1 to TPC_tempN are equal to -1. N 1 Otherwise, TPC_cmd is set to 1 if N ∑ TPC _ temp i =1 i > 0.5 . Otherwise, TPC_cmd is set to 0. Then, after deriving a combined TPC_cmd, the UE will adjust uplink transmit power as 1dB step.I. Downlink Inner-Loop Power Control Downlink inner-loop power control is used to control the power of the downlink DPCH. The UE receives the SIR target from higher layers, estimates the downlink SIR from the pilot symbols of the downlink DPCH, and compares this estimated SIR with the SIR target.  If the estimated SIR is greater than the SIR target, the UE sends a TPC command "down" to the NodeB.  Otherwise, the UE sends a TPC command “up”. TPC SIR estimation and compare with SIR target 1500 Hz SIR target NodeB UE Figure 1.14Downlink inner-loop power control The following describes the downlink inner-loop power control: 1 Single Radio Link The downlink power control can be classified into two modes. Huawei Technologies Proprietary 51
  55. 55. The UE shall check the downlink power control mode (DPC_MODE) before the TPCcommand is generated: If DPC_MODE = 0, The UE sends a unique TPC command in each slot and the TPC command generated is transmitted in the first available TPC field in the uplink DPCCH. If DPC_MODE = 1, The UE repeats the same TPC command over 3 slots and the new TPC command is transmitted such that there is a new command at the beginning of the frame.The DPC_MODE parameter is a UE-specific parameter controlled by the UTRAN.The DPC mode can be set by the DL POWER CONTROL MODE parameter. Parameter name DL power control mode Parameter ID DPCMODE GUI range SINGLE_TPC, TPC_TRIPLET_IN_SOFT, TPC_AUTO_ADJUST. Physical range& unit None Default value SINGLE_TPC Optional / Mandatory Optional MML command SET FRC Description: SIGNLE_TPC, a fast power control mode, indicates that a unique TPC command is sent in each time slot on DPCCH. TPC_TRIPLET_IN_SOFT, a slow power control mode, indicates that the same TPC command is sent in three time slots, it is applicable to soft handover and it can decrease the power deviation. TPC_AUTO_ADJUST, an automatically adjusted mode, indicates that the value of DPC_MODE can be modified by sending the message "ACTIVE SET UPDATE" to UE. Configuration Rule and Restriction: Huawei sets the DL POWER CONTROL MODE parameter to singel_TPC as default value for all power control configurations Huawei Technologies Proprietary 52
  56. 56. Upon receiving the TPC commands, the UTRAN shall adjust its downlinkDPCCH/DPDCH power accordingly. If DPC_MODE = 0, the UTRAN shall estimate the transmitted TPC command TPCest to be 0 or 1, and shall update the power every slot. If DPC_MODE = 1, the UTRAN shall estimate the transmitted TPC command TPCest over three slots to be 0 or 1, and shall update the power every three slots.After estimating the k:th TPC command, the UTRAN shall adjust the current downlinkpower P(k-1) [dB] to a new power P(k) [dB] according to the following formula:P(k) = P(k - 1) + PTPC(k) + Pbal(k)Where: PTPC(k) is the k:th power adjustment due to the inner loop power control. Pbal(k) [dB] is a correction according to the downlink power control procedure for balancing radio link powers towards a common reference power. For a single radio link, Pbal equals 0. PTPC(k) is calculated according to the following: – If the value of Limited Power Increase Used parameter is Not used, then, + Δ if TPC est ( k ) = 1PTPC (k ) =  TPC , [dB] − Δ TPC if TPC est (k ) = 0The limited power increase used parameter could be set by the parameter ofINNER_LOOP_DL_LMTED_PWR_INC_SWITCH. Huawei Technologies Proprietary 53
  57. 57. Parameter name Power control algorithm switch Parameter ID INNER_LOOP_DL_LMTED_PWR_INC_SWITCH GUI range 1(ON), 0(OFF) Physical range& unit None Default value 0 Optional / Mandatory Optional MML command SET CORRMALGOSWITCH Description: When it is checked, limited power increase algorithm is applied in the inner loop power control. – If the value of limited power increase used parameter is Used, then, the k:th inner loop power adjustment shall be calculated through the following formula: + ∆ TPC if TPC est (k ) = 1 and ∆ sum (k ) + ∆ TPC < Power_Raise_Limit  PTPC (k ) =  0 if TPC est (k ) = 1 and ∆ sum (k ) + ∆ TPC ≥ Power_Raise_Limit , [dB] − ∆ if TPC est ( k ) = 0  TPCThe Power_Raise_Limit can be set by the POWER INCREASE LIMIT parameter. Parameter name Power increase limit Parameter ID POWERRAISELIMIT GUI range 0–10 Physical range& unit dB Default value 10 Optional / Mandatory Optional MML command ADD CELLSETUP/MOD CELLSETUP Description: The increase of DL transmit power within DlPowerAverageWindowSize cannot exceed this parameter value. Huawei Technologies Proprietary 54
  58. 58. Caution:In order to change the value of the POWER INCREASE LIMIT parameter throughMOD CELLSETUP, the cell shall be firstly de-activated through DEA CELL.Where: k−1∆ (k ) = sum i= − ∑PTPC (i ) k DL_Power_Averaging_Window_Sizeis the temporary sum of the last DL_Power_Averaging_Window_Size inner looppower adjustments (in dB). DL_Power_Averaging_Window_Size can be set by theDL POWER WINDOW AVERAGE SIZE parameter. Parameter name DL power window average size Parameter ID DLPOWERAVERAGEWINDOWSIZE GUI range 1–60 Physical range& unit slot. Default value 20 Optional / Mandatory Optional MML command ADD CELLSETUP/MOD CELLSETUP Description: Content: UTRAN calculates the increase of DL transmit power within the period defined via this parameter to determine whether the increase exceeds PowerRaiseLimit. If so, UTRAN will not increase the power even when it receives the command to raise the power. Huawei Technologies Proprietary 55
  59. 59. Caution: In order to change the value of the DL POWER WINDOW AVERAGE SIZE parameter through MOD CELLSETUP, the cell shall be firstly de-activated through DEA CELL. The power control step size TPC can be any of the four values of 0.5, 1, 1.5 and 2 dB and be set by the FDD DL POWER CONTROL STEP parameter. Parameter name FDD DL power control step size Parameter ID FDDTPCDLSTEPSIZE GUI range STEPSIZE_0.5DB, STEPSIZE_1DB, STEPSIZE_1.5DB, STEPSIZE_2DB. Physical range& unit 0.5, 1, 1.5, 2(dB) Default value STEPSIZE_1DB Optional / Mandatory Optional MML command SET FRC Description: Content: The step size of the closed loop power control performed on DL DPCH in Frequency Division Duplex (FDD) mode. 2 Scenario Softer Handover In the case of softer handover, the NodeB gets one TPC after MRC combination. Then the downlink power procedure is the same as that in single radio link. 3 Soft Handover For details about the soft handover, refer to the description in the subsection 1.6.5“Downlink Power Balance”.1.6.4 Outer-Loop Power Control The aim of outer-loop power control is to maintain the communication quality at the Huawei Technologies Proprietary 56
  60. 60. level required by the service bearer through adjustment of the SIR target. This control acts on each DCH belonging to the same RRC connection. The SIR target needs to be adjusted when the UE speed or the multi-path propagation environment changes, so that the communication quality can maintain the same. If a fixed SIR target is selected, the resulting quality of the communication might be too low or too high, which may cause an unnecessary power rise in most situations.I. Uplink Outer-Loop Power Control The uplink quality is observed after macro diversity selection combining in the RNC. Therefore, uplink outer-loop power control is performed in the SRNC. The SRNC compares the RX BLER with the BLER target. If the RX BLER is greater than the BLER target, the SRNC increases the SIR target; otherwise, decreases. After adjusting the SIR target, the SRNC sends the new SIR target through FP frames to all NodeBs for uplink inner loop power control. BLER SIR measurement measurement and comparing and comparing Outer loop Inner loop BLER target settting SIR target settting Sent TPC UE RNC NodeB Figure 1.15Uplink outer-loop power control procedure The uplink outer-loop power control for all UEs can be deactivated by OLPC_SWITCH; or by setting SIR ADJUSTMENT STEP to zero to deactivate uplink outer loop power control for different services. Huawei Technologies Proprietary 57
  61. 61. Parameter name Power control algorithm switch Parameter ID OLPC_SWITCH GUI range 0, 1. Physical range& unit OFF, ON (NONE) Default value 1 Optional / Mandatory Optional MML command SET CORRMALGOSWITCH Description: When it is ON, RNC will update the uplink SIR TARGET of RLs on the NODEB side by IUB DCH FP signals.1 Initial SIR Target SettingThe initial SIR target value is provided by the RNC to the NodeB through the SIR INITTARGET VALUE parameter which is service-dependent. This value is transmitted tothe NodeB using NBAP signaling at each RADIO LINK SETUP or RADIO LINKRECONFIGURATION PREPARE. Parameter name SIR init target value Parameter ID INITSIRTARGET GUI range 0–255 Physical range& unit -8.2–17.3; step: 0.1(dB) Default value Refer to I. Optional / Mandatory Mandatory MML command ADD TYPSRBOLPC/MOD TYPSRBOLPC/ ADD TYPRABOLPC/MOD TYPRABOLPC Description: This parameter defines the initial SIR target value of Outer Loop Power Control algorithm. Value 0 corresponds to -8.2 dB, value 10 to -7.2 dB, and value 255 to 17.3 dB. Configuration Rule and Restriction: Huawei Technologies Proprietary 58

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