LA0 AdmissionControl RU20

RAB Establishment -Radio Access Bearer-Module Objectives
At the end of the module you will be able to:
Describe the admission criteria for UL & DL
Describe the decision procedure of the AC for RT & NRT RABs
Describe the role of the Packet Scheduler in the Admission Control
Name the main AC parameters derives from the RAB parameter set
Name & describe the main parameters AC delivers to other RRM entities
* © Nokia Siemens Networks RN31631EN20GLA0
Admission Control Functional Overview
Decides if new RAB request is admitted into UTRAN
AC tasks:
& Physical Channels configuration
D) RL power allocation
LC
AC
Core NW
QoS parameters
WRAB object
RT CS call
selection
AC
CS = circuit switched
PS = packet switched
PS S UL:E-DCH/DL:HS-DSCH
QoS class
AMR (5.90, 4.75)
RU20
PS I/B DCH(0,8,16,32,64,128,256,384)/DCH(0,8,16,32,64,128,256,384)
PS I/B DCH(16,64,128,384)/HS-DSCH
PS I/B E-DCH/HS-DSCH
Speech + PS Streaming
PS S DCH(8,16,32,64,128)/DCH(8,16,32,64,128,256,384)
PS S DCH(8,16,32,64,128)/HS-DSCH
PS S E-DCH/HS-DSCH
+ 0-3 PS Interactive / Background
PS S E-DCH/HS-DSCH
Multiple PS RBs always use the same transport channels!
RAB – Multi Call
Radio bearer bit rate – PS
Maximum RB data rate is used in the admission decision & for DCH transport format definition
Maximum RB data rate is defined as the maximum supported data rate that is equal to or smaller than the maximum bit rate specified in the RAB attributes
If the maximum data rate of the RAB attributes is smaller than the minimum supported data rate , then the minimum supported data rate is used as the maximum RAB data rate in the admission decision
The supported data rates are defined by
MaxBitRateDLPSNRT, MaxBitRateULPSNRT
MinAllowedBitRateDL, MinAllowedBitRateUL
BitRateSetPSNRT
The bit rates listed in the set are the maximum bit rates that can be allocated to NRT RAB.
Any value not listed in the set are not allocated to any NRT RABs
discussed in the section
Channel decoding
The following calculations are performed:
The Block Error Rate (BLER) targets both for UL & DL
Quality Target for the service / services in questions
The RAB specific planned Eb/No both for UL & DL
DCH EbNos are used in power and throughput estimations
The initial value of UL SIR target for outer loop PC.
UL outer loop power control starting value
Upper & lower limits for the UL SIR target.
Allowed operation are for UL Outer Loop Power Control
“Connection based Quality Control” is name of this new concept in RRM
EbNo parameter implementation is changing in RU10
Parameters can be configured by operator (WRAB object)
Final DCH EbNo must be determined for throughput & power estimations
Eb/No definable
1) Service-specific
Admission control determines the following configuration parameters for the needs of the UL outer loop power control entity of the RNC:
quality target, that is block error ratio target (target BLER) value, is produced for a DCH allocated for a RAB.
initial value of UL SIR target, and upper & lower limits for the UL SIR target are produced.
The quality target is produced also for the needs of the DL outer loop power control entity located in the user equipment. Configuration parameters are produced for an individual RRC connection each time dedicated resources are allocated or modified.
Connection based quality control parameters define the service and signaling bearer specific quality targets and their related power thresholds for each transport channel configuration. Besides of the bearer attributes, the values of the parameters can depend on the channel conditions such as propagation environment, multi path conditions, and mobile speed. The
parameters are stored in the Object WRAB of the RNW data base in the RNC.
Up to 5 WRAB objects can be created by the operator to define the parameter sets of the quality control. Management parameter WRABId identifies each WRAB object uniquely in the RNC. The operator associates one of the objects with its parameter set to the BTS cell by
defining the identifier of the object with the cell specific management parameter EbNoSetIdentifier.
For a subset of the management parameters related to the WRAB object, the modification of the parameter value requires reconfiguration of the BTS. This subset of parameters can only be modified if all those WCEL objects are locked that have an association to the WRAB object defined with the management parameter EbNoSetIdentifier.
A WRAB object can only be deleted if it has no association to any WCEL object defined with the management parameter EbNoSetIdentifier.
Eb/No: UL/DL Quality Target
Parameter Database Object is WRAB
For PS NRT IA/BG there can be 2 quality targets in operation – dep. on bitrate
Quality Target 1
Quality Target 2
Quality Target 1
Quality Target 2
Quality target
Cell specific Admission Control reads both the UL DCH & DL DCH quality targets for the RAB from the RAB specific management parameter regardless of the values of the RAB attributes received from MSC:
CS AMR speech: EbNoDCHOfCSNBAMRQua
CS AMR-WB speech: EbNoDCHOfCSWBAMRQua
CS transparent data: EbNoDCHOfCSDataTQua
CS non-transparent data: EbNoDCHOfCSDataNTQua
PS Interactive (IA) & Background (BG) services: The UL & DL DCH has one of the data rates 8, 16, 32, 64, 128, 256 or 384 kbps allocated as its max. DCH user data rate.
Quality target of the UL DCH is set to the value of the management parameter EbNoDCHOfPSNRTPriQua, if the selector of the parameter EbNoDCHOfPSNRTSelQuaUL is set for the max. user bit rate of the DCH.
. Quality target of the UL DCH is set to the value of the management parameter EbNoDCHOfPSNRTSecQua, if the selector of the parameter EbNoDCHOfPSNRTSelQuaUL is not set for the max. user bit rate of the DCH.
. Quality target of the DL DCH is set to the value of the management parameter EbNoDCHOfPSNRTPriQua, if the selector of the parameter EbNoDCHOfPSNRTSelQuaDL is set for the max. user bit rate of the DCH.
. Quality target of the downlink DCH is set to the value of the management parameter EbNoDCHOfPSNRTSecQua, if the selector of the parameter EbNoDCHOfPSNRTSelQuaDL is not set for the max. user bit rate of the DCH.
Eb/No: UL/DL Quality Target
Quality Target for Signaling Radio Bearers (SRB)
Please note (1) default value: only Quality Target 1 is used
Please note (2) : Same parameter concept for Streaming services using DCH
Parameter
EbNoDCHOfPSNRTSelQuaDL
Bit 0: 8 kbps , Bit 1: 16 kbps , Bit 2: 32 kbps , Bit 3: 64 kbps , Bit 4: 128 kbps , Bit 5: 256 kbps , Bit 6: 384 kbps
127 (Dec)
EbNoDCHOfPSNRTSelQuaUL
Bit 0: 8 kbps , Bit 1: 16 kbps , Bit 2: 32 kbps , Bit 3: 64 kbps , Bit 4: 128 kbps , Bit 5: 256 kbps , Bit 6: 384 kbps
127 (Dec)
PS streaming services: Consider that the UL DCH has one of the data rates 8, 16, 32, 64 or 128 kbps allocated as its max. DCH user data rate and the DL DCH has one of the data rates 8, 16, 32, 64, 128 or 256 kbps.
. Quality target of the UL DCH is set to the value of the management parameter EbNoDCHOfPSStrPriQua, if the selector of the parameter EbNoDCHOfPSStrSelQuaUL is set for the maximum user bit rate of the DCH .
Quality target of the UL DCH is set to the value of the management parameter EbNoDCHOfPSStrSecQua, if the selector of the parameter EbNoDCHOfPSStrSelQuaUL is not set for the max. user bit rate of the DCH.
. Quality target of the DL DCH is set to the value of the management parameter EbNoDCHOfPSStrPriQua, if the selector of the parameter EbNoDCHOfPSStrSelQuaDL is set
for the max. user bit rate of the DCH.
. Quality target of the DL DCH is set to the value of the management parameter EbNoDCHOfPSStrSecQua, if the selector of the parameter EbNoDCHOfPSStrSelQuaDL is not set for the maximum user bit rate of the DCH.
. SRB13.6: EbNoDCHOfSRB136Qua
. SRB3.4: EbNoDCHOfSRB34Qua
AC calculates DCH EbNo from parameters in WRAB object
Site, Cell specific (site configuration N-path Rx) N = 1, 2, 4
Service specific EbNos:
SRB, AMR, CS Data, PS Data , PS Streaming, EDCH Streaming
Eb/Nos are obtained for UL & DL separately
Both dedicated & signalling channels have their own targets
EbNos represent one-way reception in WBTS receiver
Final DCH EbNo is calculated taking into account (UL) site configuration
WRAB Id 1
example: AMR 12,2
* These parameters defines the value of the planned Eb/N0 for the DCH, which transfers the protection class B / C RAB subflow of the CS NB-AMR speech
with the codec set (12.2), (12.2, 7.95, 5.9, 4.75) or (5.9, 4.75). The value of the Eb/N0 is expressed in relation to the Eb/N0 value of the protection class A
subflow DCH. The parameter is applied for the UL & DL DCHs.
Service Type
EbNo values for PS IA/BG services
Depending on service Bitrate, gain factor can be applied
Higher Bitrate experience better quality planned EbNo can be lowered:
Next Slide
8 dB
6,5 dB
Trigger to apply Rate Matching (EbNo) gain
Please note: Data rate gain is applied with the UL DPDCH data rates > 120 kbps.
7
15
EbNoDCHRateGainSFDown
UL
DL
Final planned EbNo value for further processing in Admission Control
EbNoCell is depending on site configuration:
Site specific parameter RxDivIndicator must be set according to number of physical UL paths configured for that Node-B.
one-way UL
two-way UL
four-way UL
EbNoDCHRxDiv2; WRAB; -6 .. 0 dB; 0.1 dB; -3 dB
EbNoDCHRxDiv4; WRAB; -6 .. 0 dB; 0.1 dB; -4 dB
Planned initial SIR targets of the UL DPCCH
Separate planned initial SIR targets are defined for the DPCCH in three different UL physical channel configurations
Initial SIR targets in the simple DPDCH configurations are defined with a set SIRDPCCHInitialDCH of the operator parameters
DPCH is the only UL physical channel configuration in this definition
Set SIRDPCCHInitialDCHHS defines also the initial SIR targets in DPDCH + HS-DPCCH configurations
HS-PDSCH is used with DPCH in UL
Initial SIR targets in the E-DPCH configurations
HS-PDSCH is used with DPCH + E-DPCH in UL
Initial target SIR for UL DPCCH
When the cell specific AC produces the initial SIR target of the UL DPCCH for the needs of the UL outer loop power control in the SRNC, it uses the 3GPP SIR value specified in 3GPP TS 25.215: Physical layer – Measurements (FDD). The 3GPP SIR value is defined as the linear sum of the SIR values from all Rx diversity antennas for the radio link.
The Rx diversity antenna specific value of the initial UL DPCCH SIR target depends on the actual UL physical channel configuration:
When neither the E-DPCH nor the HS-DPCCH is configured in any radio link of the RRC connection, the value of the initial SIR target is defined with the SIRDPCCHInitialDCH4, SIRDPCCHInitialDCH8, SIRDPCCHInitialDCH16, SIRDPCCHInitialDCH32, SIRDPCCHInitialDCH64, SIRDPCCHInitialDCH128, SIRDPCCHInitialDCH256, SIRDPCCHInitialDCHRxDiv2, SIRDPCCHInitialDCHRxDiv4 & SIRDPCCHInitialDCHOffset parameter set of the Initial SIR target for UL DPCCH with DPDCH (SIRDPCCHInitialDCH) structured management parameter.
Parameters are read from the WRAB object of the radio network database identified with the management parameter EbNoSetIdentifier.
The initial SIR target depends on the size of the UL DPDCH minimum spreading factor and the used Rx diversity; a particular offset value can be defined with the SIRDPCCHInitialDCHOffset management parameter.
When the HS-DPCCH is configured in the radio link, but the EDPCH is not configured in any radio link of the RRC connection, the value of the initial SIR target is defined with the SIRDPCCHInitialDCHHS4, SIRDPCCHInitialDCHHS8, SIRDPCCHInitialDCHHS16, SIRDPCCHInitialDCHHS32, SIRDPCCHInitialDCHHS64, SIRDPCCHInitialDCHHS128, SIRDPCCHInitialDCHHS256, SIRDPCCHInitialDCHRxDiv2, SIRDPCCHInitialDCHRxDiv4 and SIRDPCCHInitialDCHOffset parameter set of the Initial SIR target for UL DPCCH with DPDCH (SIRDPCCHInitialDCH) structured management parameter.
Parameters are read from the WRAB object of the radio network database identified with the management parameter EbNoSetIdentifier.
The initial SIR target depends on the size of the UL min. spreading factor and the used Rx- diversity; particular offset value can be defined with the SIRDPCCHInitialDCHOffset management parameter.
Initial SIR targets in the DPDCH configurations
SIRDPCCHInitialDCH is a set of parameters, which define the initial SIR targets:
Initial SIR value for each DPDCH SF value 256, 128, 64, 32, 16, 8 & 4, assuming 1-way Rx- diversity. Default values:
Initial SIR value in relation to the values of 1-way receiver diversity, assuming 2-way Rx-diversity. SIRDPCCHInitialDCHRxDiv2; WRAB; -6 .. 0; 0.1; -3 dB.
Initial SIR value in relation to the values of 1-way receiver diversity, assuming 4-way Rx- diversity. SIRDPCCHInitialDCHRxDiv4; WRAB; -6 .. 0; 0.1; -4 dB.
Receiver diversity is defined with the management parameter RxDivIndicator
These SIR target values are used in producing the DPCCH overhead load factors and UL DPCCH/DPDCH power ratios of this configuration
Value of the parameter SIRDPCCHInitialDCHOffset is added before sending the initial SIR target to the UL outer loop power control.
SIRDPCCHInitialDCHOffset
SF of DPDCH
Initial SIR targets
SIRDPCCHInitialDCHHS is a set of parameters, which define the initial SIR targets:
Initial SIR value for each DPDCH SF value 256, 128, 64, 32, 16, 8 & 4, assuming 1-way Rx-diversity. Default values:
Initial SIR value in relation to the values of 1-way receiver diversity, assuming 2-way Rx- diversity. Default value is – 3 dB.
Initial SIR value in relation to the values of 1-way receiver diversity, assuming 4-way Rx- diversity. Default value is – 4 dB.
These SIR target values are used in producing the UL DPCCH/DPDCH power ratios for this configuration; DPCCH overhead load factors are defined from the initial SIR target values of the ‘DPDCH configurations’.
Value of SIRDPCCHInitialDCHOffset is added before sending the initial SIR target to the UL outer loop power control.
HS-PDSCH used with DPCH in UL
SIRDPCCHInitialDCHOffset
SF of DPDCH
Initial SIR targets in the E-DPCH configurations*
RNC defines Initial SIR target values internally, there is no configurable parameter introduced yet
These SIR target values are used in producing the UL DPCCH/DPDCH power ratios for this configuration; DPCCH overhead load factors are defined from the initial SIR target values of the ‘DPDCH configurations’.
Initial SIR target values also used in configuring UL OLPC.
* HS-PDSCH used with DPCH + E-DPCH in UL
Min. & Max. SIR target
SIRDPCCHInitialDCHMax
E-DPCH not configured for the RRC connection:
Max. SIR target value achieved adding SIRDPCCHInitialDCHMax to the initial SIR target
Min. SIR target value achieved adding SIRDPCCHInitialDCHMin to the initial SIR target
E-DPCH configuration RNC internal values :
min. SIR target value: -3 dB
max. SIR target value: 9 dB
Max. SIR Target
Min. SIR Target
Maximum & minimum values of the UL 3GPP SIR target
The cell specific AC defines the max. & min. values of the UL 3GPP SIR target for the outer loop power control.
If the E-DCH is not configured in any radio link of the RRC connection, the max. & min. values of the UL 3GPP SIR target are defined as follows:
maximum values: (targetSIRDPCCH - offsetDCH) + SIRDPCCHInitialDCHMax
minimum values: (targetSIRDPCCH - offsetDCH) + SIRDPCCHInitialDCHMin
Management parameters SIRDPCCHInitialDCHMax and SIRDPCCHInitialDCHMin are read from the WRAB object identified with the management parameter EbNoSetIdentifier.
If the E-DCH is configured in a radio link of the RRC connection, the max. & min. values of the SIR target are defined internally by the cell specific AC as described in the RRM of HSUPA functional area description.
RLC Transfer Mode
AC determines the UL & DL RLC transfer mode for RNC & UE
RLC transfer mode indicates, whether the RLC entity of a RB shall use an Acknowledged (AM), an Unacknowledged (UM) or a Transparent (Tr) Mode data transfer.
Equal transfer mode is used in UL and DL for a RB.
The transfer mode is determined from the RAB parameters and CN domain information.
DCH/HS-DSCH
E-DCH/HS-DSCH
Transport Formats (TF)
TrCH Parameters
In UTRAN, the data carried at higher layers is carried over the air interface using transport channels mapped on to different physical channels.
Transport Formats describe how Transport Channels are mapped to Physical channels at layer 1.
The Transport Format is the format offered by L1 to MAC. MAC is responsible for mapping logical channels on to transport channels.
MAC selects the appropriate TF within an assigned TFS for each active TrCH depending on the source rate (efficient use of transport channels), given the TFCS assigned by the RRC.
A Transport Format Combination is a combination of valid TFs that can be submitted simulataneously to layer 1 on a Coded Composite transport channel (CCTrCH)of a UE. Ie containing one TF from each TrCH that is part of the combination.
Transport Format Combination Sets is defined as a set of TFC on a CCTrCH and is produced by a proprietry algorithm in the RNC. The TFCS is given to MAC by L3 for control. When mapping data to L1, MAC chooses between the different TFCs specified within the TFCS
Transport Format Indicator (TFI) is a label for a specifc TF within a TFS. It is used in the inter-layer communication between MAC and L1, each time a TBS is exchanged between the two layers on a transport channel.
SL=signalling, RT RB = Real Time Radio Bearer
The PHY layer can multiplex several Transport Channels in one „internal“ Transport Channel, called Coded Composite Transport Channel (CCTrCH). This CCTrCH can be transmitted on one or several physical channels. Consequently, the TFCSs of different Transport Channels can be found in one radio frame.
The Transport Format Combination Set (TFCS) lists all allowed Transport Format Combinations (TFC). A Transport Format Combination Indicator (TFCI) is then used to indicate, what kind of Transport Format Combination is found on the radio frame. You can find TFCI-fields for instance in the S-CCPCH. The TFCS is set by the RRC protocol.
AC allocates a zero bit rate for the NRT RAB
PS allocates the bit rate to the radio bearer after reception of Capacity Request CR
PS checks load and makes estimate of the load change
No power based decision is made in AC decision for NRT RAB
AC produces the TFS for NRT RBs based on RAB requirements
AC will check that the maximum bit rates requested in the RAB Assignment Request message are than operator configurable limits for the specific target cell
QoS negotiation RAB bit rate is decreased to the cell maximum bit rate
WCEL: MaxBitRateDLPSNRT and WCEL: MaxBitRateULPSNRT define the maximum allowed bit rates in a cell
Range & steps: [8, 16, 32, 64, 128, 256, 320, 384] kbps, default: 384 kbps
Streaming Class for DCH & HSPA is supported from RU10 onwards
There are different criteria checked depending whether Streaming Class is involved or not
Semi-Controllable SC load introduced for Streaming services
Pmax
Noise Rise
i-factor
PrxOffset
PrxTarget
default: 2 dB: equals 37% own cell load
NST = Non-Scheduled Transmission = PS Streaming on E-DCH
NST is under RNC scheduling, but uses E-DCH-related physical channels including L1 retransmission
UL Admission Control is hybrid solution based on
Power estimations & Throughput* calculations
Basic UL admission decision criteria for an RT resource request (other Service than Streaming)
If the load factor exceeds the specified minimum, the estimated non-controllable UL interference power is compared against the threshold
If the equation is NOT fulfilled then the RAB can NOT be admitted!
Prx_target = PrxNoise + PrxTarget
Quantity ΔL is the change in the RT DCH load factor of the RRC connection
Calculated by RNC, based on service properties like bitrate EbNo etc.
PrxLoadMarginDCH:
LminDCH 37%
Remember ?
Basic UL admission decision criteria for an RT resource request (Streaming Service on DCH or HSPA)
Streaming traffic is defined as semi-controllable load (sc)
Semi-controllable load must be considered separately
ΔL = change in the own cell load factor of the PS streaming users representing the PS streaming
Δ Prx_SC = estimated received power increase caused by new PS streaming users (including also inactive RT DCH & PS streaming RBs
Prx_total is the average received total non-controllable interference power
Remember ?
PrxLoadMarginDCH:
LminDCH 37%
Conversion of parameters to throughput thresholds
In interference domain, planning parameters are introduced to define own cell load threshold for interference (power) and throughput AC calculations
Minimum throughput threshold is obtained from management parameter by:
Maximum throughput threshold is obtained from management parameter by:
If the MaxDCH threshold is met, overload actions are triggered. Default = off
where lin indicates conversion from dB to linear units
WCEL: PrxLoadMarginDCH
Default: 2 dB (equals 37% own cell load)
Relative to PrxNoise in the cell
WCEL: PrxLoadMarginMaxDCH
Default: 0 dB
Load factor LDPCH of the RRC connection:
W: chip rate 3.84 Mc/s
(Eb/No)DCH: required Eb/No of the DCH
RDCH: maximum DCH bit rate
νDCH: activity factor of the DCH
For every service (User Plane) allocated in the cell of question – incl. streaming service
Load factor LDPDCH represents the DPDCH code power only; it doesn’t include the DPCCH overhead part yet.
Planned Eb/Nos are not including the DPCCH overhead.
Load factor LDPCCH of the DPCCH is defined with the SIR and the spreading factor of the DPCCH SFDPCCH = 256.
Planned SIR target value is used as the SIRDPCCH.
UL own cell DCH load factor
UL DCH load factor LDCH,CELL of all DPCH users of the cell can now be produced as a sum
UL own cell DCH load factor LDCH,CELL is applied both for throughput and interference based DCH resource allocations in CRNC
Last but not least, RNC also calculates for each RRC connection having active HSDPA connection the additional UL load coming from HS-DPCCH physical channel. There is additional power allocated for HS-DPCCH – this power is received by WBTS receiver in UL.
… having all these data RNC can make the decision!
This applies, if the minimum throughput threshold is exceeded
Admission decision is then based on cell specific power and throughput thresholds given by RNP
In UL the total received wideband interference power measured from the wideband channel indicates the traffic load of the radio resources
Power based admission decision criterion:
power
load
Estimation of UL Prx_nc
AC estimates the increase in the total non-controllable UL power of a cell using a proprietary estimation algorithm (next slide)
Estimation of the load increase, L, for that RAB is made based on bit rate, Eb/Nos etc.
L is mapped to an estimated value of Prx_nc using a load vs power curve.
Change in load factor L is calculated by AC based on the new bearer Eb/No requirement.
The corresponding estimated new received Non-Controllable power is calculated by AC using integral method and using the Load vs. Prx_nc curves maintained by AC for every cell
L
Δ
L
Δ
Prx_nc
Prx_nc
Current load L & current received Non-Controllable power Prx_nc are measured
Calculation of UL Prx_nc
The total received wideband interference power can be expressed as the sum of:
the power caused by non-controllable traffic, Prx_nc,
the power caused by semi-controlable traffic, Prx_sc
the power caused by controllable traffic of non-real-time users, Prx_nrt
The non-controllable interference power, Prx_nc, consists of the powers of real-time users (other than streaming), other-cell users, and noise
UL traffic load caused by the NRT RABs for which the Packet Scheduler (or Load Control) can freely adjust the UL power (i.e., the UL transmission bit rate) according to the current load, even drop it to zero when necessary (the best effort type of services)
Parameters
When the non-controllable part of the cell load exceeds the target limit, AC will reject those RAB establishment requests that would mean immediate UL load increase (i.e. RT services) (not true for WPS call)
PS responsible on handling NRT bearer
When load is too high bit rates are decreased etc.
When the PrxTarget level has been exceeded
it is possible for the AC/PS to admit NRT services (AC)
it is possible to schedule (allocate) bitrate for NRT services
bitrate (load) increase for NRT is not possible
Prx_NC
[dBm]
PrxTotal
[dBm]
Note:
PtxTarget_BS is defined as PtxTarget + Ptx Offset
Admission Decisions - Exercise (AMR voice call request) CASE 1
Prx_Target_BS
Prx_Target
Prx_NC
Prx_NC
maximum
throughput
&& = AND function
Prx_Target_BS
Prx_Target
Prx_NC
Power check
maximum
throughput
solution of previous slide:
?
Prx_Target_BS
Prx_Target
maximum
throughput
?
Prx_SC
LDCHmin
LmaxDCH
maximum
throughput
?
Power check
DPCCH Initial Power
After PRACH procedure the initial UL DPCCH transmit power is set by RRC
When one or more radio links already exist then the current UL transmission power is used as initial transmission power for new radio link to be established
When establishing the first DPCCH the UE starts the UL inner loop power control at a power level according to:
DPCCH_Initial_power = TxCPICH – CPICH_RSCP + RTWP + SIRDPCCH – 10 • log (SFDPCCH)
Where:
TxCPICH is the transmission power of Primary CPICH given by the RNP parameter WCEL: PtxPrimaryCPICH
RTWP is the received wide band interference power measured by BTS and offered by LC (UL_Interference)
RTWP = MIN {Prx,total, Prx,total, Prx-Target}
SIRDPCCH is the required received SIR for DPCCH; it equals to the initial DPCCH SIR target
SFDPCCH is the Spreading Factor of the UL DPCCH
The value for the CPICH_RSCP is measured by the UE
DPCCH_Power_offset = TxCPICH + RTWP + SIRDPCCH – 10 • log (SFDPCCH)
is determined by AC/PS of RNC and its value is signalled to the UE in the UL DPCH power control info IE included in the RRC CONNECTION SETUP message
WCEL: UEtxPowerMaxDPCH
defines the max. transmission power level a UE can use on DPCH. It is signaled to UE in the Maximum allowed UL TX power IE of a proper RRC message, when a radio link is set up
range: -50 ... 33 dBm, step 1 dB default: 24dBm
WCEL: UEtxPowerMaxPRACH
Defines the maximum transmission power level a UE can use on PRACH. The value of the parameter also affects the cell selection and reselection procedures. The value of the parameter is sent to UE in the Cell selection and re-selection of System Information Blocks 3 and 4 of the serving cell
range: -50 ... 33 dBm, step 1 dB default: 21dBm
The minimum UE transmission power is defined in 3GPP TS 25.101: 6.4.3 “Minimum UE output power”: The minimum output power shall be less than -50 dBm
Estimation of DL Ptx_nc
Admission decision based on cell specific thresholds given by RNP (same as UL)
Each BTS measures the total transmitted DL power (PtxTotal) of each cell, and reports the results to the RNC by using RADIO RESOURCE INDICATION message
BTS applies same process as UL for calculating averaged Ptx_Total values
RNC applies sliding window averaging using WinAcRabSetupDl to obtain av Ptx_Total
Ptx_total can be expressed as the sum of the power caused by the non-controllable traffic, Ptx_nc (excluding streaming services), the semi-controllable power Ptx_sc and the power caused by the controllable traffic of NRT users, Ptx_nrt:
Ptx_Total can be calculated in the same way as Prx_Total
For each RAB request AC has to estimate the increase in the total non-controllable transmission power (caused by the new RAB), Ptx_NC or Ptx_SC
Available Power for non-controllable load can be calculated:
WinAcRabSetupDl
50..2000; 50; 100 ms
Ptx,nc = Ptx_total – Ptx_nrt – Ptx_SC
Estimation of DL Ptx_nc
For each resource request the AC calculates the change of DL load : ΔPtx_nc
Unlike UL estimation, there is no load curve used to estimate the DL transmit power increase associated with a new RAB
The increase in non-controllable power due to a new RT RAB, Ptx_nc, is calculated as the initial DL transmit power
The initial DL transmit power is calculated:
Ptx,CPICH: CPICH transmit power
Ptx_Total: total DL Tx power reported by the Node B
a: Orthogonality Factor
required Eb/No
DL Cell Load Admission Criteria Thresholds
For the RB to be established (non streaming service requests) the increase of the non-controllable load Ptx_nc is estimated on the basis of the measured
Then the estimated non-controllable DL power is compared against the threshold
Equation NOT satisfied RAB NOT admitted !
Ptx_nc = Ptx_total – Ptx_nrt
Initial DL Power Allocation – RL setup
When the RL is established (RRC connection setup) the following equation is used to defined the initial DL power
The determination of the transmission power requires knowledge about several parameter values:
planned Eb/No of the connection (EbNo RM + EbNo Cell)
signal-to-interference ratio per chip of the CPICH ( ) measured by the UE
W is the chip rate, R is bit rate, Ptx_total is measured by the base station (and reported back to the RNC in Radio Resource Indication)
Ptx_CPICH is the CPICH power (determined by PtxPrimaryCPICH)
is the orthogonality factor (WRAB: DLOrthog: 0 .. 1; 0.01; 0.5)
Initial DL Power Allocation – RL modification
When the RL is modified (RAB setup etc.) the initial DL power of the modified RL is calculated as
the planned Eb/No and bit rate R of the old & new DCH allocations are taken into account
Initial DL Power Allocation
R = 64 kbit/s service with required DL Eb/No: 4.5dB = 2.82
PtxCPICH: 30dBm = 2 W
Therefore:
Initial DL Power =
Ptx_init = 2.82*64/3840 • (1/0.1 • 2W - 0.5 • 5.011W) = 822.5 mW (29.15 dBm)
DL power allocation of a radio link
Radio Link established or modified both maximum DL Tx power & minimum DL Tx power has to be determined for it
The average power of transmitted DPDCH symbols over 1 timeslot must not exceed maximum DL Tx power, or it can not be below minimum DL Tx power
The Power Control Dynamic Range of BTS is the difference between the maximum and the minimum transmit output power of a code channel
DL power allocation of a radio link
+ PtxDPCHMax
- CPICHtoRefRABOffset
+ PTxDPCHmin
WCEL; -60..-28; 1; -28 dB
In most cases we are operating in this range for voice. For PS data the PtxDLabsMax can be lower than the upper limit dictated by this
PtxDLabsMax (PS NRT) & PtxPSstreamAbsMax (PS RT)
setting max. power for radio link;
own parameter for
PtxPrimaryCPICH
PtxCellMax
PtxPrimaryCPICH
CPICHtoRefRABOffset
PtxDLabsMax
PtxPSstreamAbsMax
PtxCellMax
PtxDPCHMax
WCEL; -3..0; 0.1; -3 dB
The max. DL power is the lowest of these 3 values for NRT & Multi-RAB
The min. DL power is the max. of these value
+ SF_adjustment
RT: Ptx_max_rl = min {P_CPICH - CPICHtoRefRABoffset + SF_adjustment, Ptxtotalmax - PTxDPCHmax}
PS & Multirab: Ptx_max_rl = min{P_CPICH – CPICHtoRefRABoffset + SF_adjustment, Ptxtotalmax - PTxDPCHmax, Ptx_AbsMax}
Define minimum radio link power:
Ptx_min_rl=max{Ptx_max_rl - PCrangeDL, Ptxmax - PTxDPCHmin}
SF_adjustment is the mapping of the max power to the actual bearer based on SF and DL Eb/No compared to the reference service* (12.2 kbps AMR)
When the radio link includes multiple bearers then the numerator of this equation includes the sum of the Eb/No, bit rate products for all bearers
RefServForCodePower
WCEL;
...
PS NRT RAB
Ptx_AbsMax = PtxPSstremAbsMax
PS streaming DCH with PS NRT DCH (PS RT&NRT multirab), when
PtxDLAbsMax ≤ PtxPSstreamAbsMax
Ptx_AbsMax = PtxDLAbsMax
PtxDLAbsMax > PtxPSstreamAbsMax,
NRT DCH bit rate shall be scheduled so that maximum allowed code power does not exceeds the value Ptx_AbsMax achieved from the equation below
RT(RL) = set of RT DCHs of RL
NRT(RL)= the set of the NRT DCHs of RL
RDCH is the maximum bit rate of the DCH
EbNoDCH is the planned Eb/No
DL Ptx_AbsMax for RL
Example
64 kbit/s CS Data service multiplexed with a 3.7 kbps SRB:
64 kbps service DL Eb/No: 4.5 dB =2.82
3.7 kbps SRB DL Eb/No: 8.0 dB = 6.31
Reference service: 12.2kbit/s speech with Eb/No: 5.5 dB = 3.55
CPICHtoRefRabOffset = 2 dB
PtxCPICH: 33 dBm
PtxCPICH - CPICHtoRefRabOffset = 33 dBm - 2 dB = 31 dBm
Ptx_DPCH_max = PtxDPCHMax =3dB below the maximum power = 40dBm
Ptx_max_rl = min(31+6.7 dBm, 40 dBm) = 37.7 dBm = 5.9 W
Ptx_max = 37.7 dBm
Ptx,range = PCrangeDL = 15dB
Ptx_DPCH_min = PtxDPCHMin = 28dB below the maximum power = 15dBm
Ptx_min_rl = max(37.7 dBm – 15 dB, 15 dBm) = max(22.7 dBm, 15 dBm)
=> Ptx_min_rl = 22.7 dBm
WCEL: PtxDLAbsMax
The planned maximum DL transmission power of radio link. This parameter is used in the DL power allocation when CCTrCH includes one or more DCH's of interactive or background traffic class RAB's. The allocated power of a radio link cannot exceed the value of this parameter. The parameter is set separately for each cell. This parameter is the planned maximum, not the physical limit
Range: -10 ... 50 dBm, step 0.1 dBm, Default: 37 dBm
WCEL: PtxPSstreamAbsMax
The planned maximum DL transmission power of radio link. This parameter is used in the DL power allocation when CCTrCH includes one or more DCH’s of streaming traffic class RAB’s. The parameter is set separately for each cell. This parameter is planned maximum, not physical limit.
Range : -10 ... 50 dBm, step 0.1 dBm, Default : 37 dBm
WCEL: CPICHtoRefRABoffset
The parameter defines the offset of the primary CPICH transmission power, and the maximum DL transmission power of the reference service channel in DL power allocation
The maximum transmission power of the reference service is calculated (in dBm) by subtracting the value of the parameter from the transmission power of the primary CPICH
range : -10 ... 17 dB, step 0.5 dB default : 2dB
Parameter: DL power allocation of a radio link
WCEL: RefServForCodePower (RAS06 and earlier: WCEL: DLreferenceBitRate)
This parameter defines the reference service for producing the maximum code power value of the radio link. Reference service is used in planning the DL coverage of the cell. The ratio of the primary CPICH code power to the maximum code power of the reference service is defined with the management parameter "Offset of the P-CPICH and reference service powers"
Range : 0 (CS AMR 12.2 kbps), 1 (CS AMR 12.65 kbps), 2 (CS transparent data 64 kbps), 3 (PS streaming 64 kbps), 4 (PS streaming 128 kbps), 5 (PS streaming 256 kbps), 6 (PS interactive 384 kbps) ; default : 0 (CS AMR 12.2 kbps)
RNC: PCrangeDL
The parameter defines the DL power control range in relation to the maximum allocated transmission power of the radio link (RL)
The min. transmission power is achieved by subtracting the value of the parameter from the max. transmission power of the RL
the min. BTS output power of the code channel defines the absolute lower limit for the minimum transmission power
range: 0 ... 25 dB, step 1 dB default: 15dB
WBTS: PtxDPCHMax
Parameter defines the maximum code channel output power for the power control dynamic range of BTS. The maximum transmission power is calculated by adding the value of the parameter to the BTS maximum output power (Pmax in dBm).
range: -3 ... 0dB , step 0.1dB default: -3 dB
WBTS: PtxDPCHMin
Parameter defines the minimum code channel output power for the power control dynamic range of BTS. Minimum transmission power is calculated by adding the value of the parameter to the BTS maximum output power (Pmax in dBm).
range: -60 ... –28dB , step 1dB default: -28 dB
Parameter: DL power allocation of a radio link
Admission Control (AC) Summary
RANPAR, Correction of supported bearers, correction of QoS negotiation; Minor corrections (B. Aschermann)
Florian Reymond
RAS06_v1.0
26.10.2007
Florian Reymond
RU10_v1.0
28.11.2008
RANPAR 1; Final Number of slides for RAB combi. Document Number must be changed
Thorsten Hagedorn
Benedikt Aschermann
Service Type
neg 0,5 dB
-2
-2
SRB
EbNoDCHRateGainSRB
neg 0,5 dB
EbNoDCHRateGainSFDown
Bit 0: SF 4 , Bit 1: SF 8 , Bit 2: SF 16 , Bit 3: SF 32 , Bit 4: SF 64 , Bit 5: SF 128 , Bit 6: SF 256
15 (Dec)
EbNoDCHRateGainSFUp
Bit 0: SF 4 , Bit 1: SF 8 , Bit 2: SF 16 , Bit 3: SF 32 , Bit 4: SF 64 , Bit 5: SF 128 , Bit 6: SF 256
7 (Dec)

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