04 Rn31634en40gla0 Ranpar1 Loadcontrol v1.1 Ru40
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Transcript of 04 Rn31634en40gla0 Ranpar1 Loadcontrol v1.1 Ru40
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1 Nokia Siemens Networks RN31634EN40GLA0
Load Control
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2 Nokia Siemens Networks RN31634EN40GLA0
Load Control:
Module Objectives
At the end of the module you will be able to:
Describe the basic principles of Load Control
Describe the relationships of Load Control with AC and PS
Identify the parameters influencing BTS load measurements
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3 Nokia Siemens Networks RN31634EN40GLA0
Load Control
Load Control Functions
Radio Interface Load
Power based Radio Resource Management
Throughput based Radio Resource Management
Planning thresholds for cell loading
BTS Measurements and Reporting
Common Measurements
Dedicated Measurements
Filtering of Measurements
Automatic Access Class Restriction
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4 Nokia Siemens Networks RN31634EN40GLA0
Load Control Functional Overview
LC is a cell based RRM Function, utilising cell specific:
thresholds set by RNP,
load measurements,
AC, PS & LC algorithms.
LC performs the function of load control in association with AC & PS
LC updates load status using resource measurements & estimations provided by AC & PS
Continuously feeds cell load information to the other RRM functions, e.g. PS & AC
LC
AC
PS RM
RNC
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5 Nokia Siemens Networks RN31634EN40GLA0
Load Control Functional Overview
RRM in RNC
LC
AC
PS
Load change estimations
Load change estimations
Scheduling period
PRACH load measurement
WBTS NB/RS NBAP-PRIVATE:
RRIndPeriod or
3GPP NBAP :
COMMON MEASUREMENT
REPORT
Dedicated measurement reporting
parameters
parameters
measurements
estimations
when changed Load change info
Load status request
Load status
NRT load
measurements
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6 Nokia Siemens Networks RN31634EN40GLA0
Load Control
Load Control Functions
Radio Interface Load
Power based Radio Resource Management
Throughput based Radio Resource Management
Planning thresholds for cell loading
BTS Measurements and Reporting
Common Measurements
Dedicated Measurements
Filtering of Measurements
Automatic Access Class Restriction
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7 Nokia Siemens Networks RN31634EN40GLA0
DL uses Power Measurements and calculations for RRM decisions
UL uses Power & Throughput estimations and calculations for RRM decisions
NSN RRM: Power & Throughput based
=
+ = N
j j UL L i
1
) 1 ( h NR P
P
total rx
noise rx
UL
1 1 1
_
_ - = - = h
max _
_
BTS tx
total tx
DL P
P = h
defining Load
h = 0% 100%
jjbj
j
NE
RWL
1
/
/1
1
0
+
=defining Little i
Slide 9
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8 Nokia Siemens Networks RN31634EN40GLA0
Load Estimation Methods and other cell interference
Throughput based
threshold
Wideband Power based
threshold
Own cell load factor h (capacity)
i=0.5
i=0
i=1
2 Load estimation
methods:
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9 Nokia Siemens Networks RN31634EN40GLA0
UL power based load measurement
PRx_Own
PRxTotal = PRx_Own + PRx_Other + PNoise
= PRx_NRT + PRx_RT + PRx_Other + Pnoise
= PRx_NRT + PRx_NC + PRx_SC PRx_Other
iUL = PRx_Other / PRx_Own
PRx_SC The semi-controllable interference power, consists of the powers of PS streaming users (DCH and E-DCH). Before RU10 semi-controllable traffic has not been separated from the non-controllable traffic, so for those releases it is equal to zero.
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10 Nokia Siemens Networks RN31634EN40GLA0
DL power based load measurement
PTx_Own
PTxTotal = PTx_Own
= PTx_NRT + PTx_RT + PTx_Common
= PTx_NRT + PTx_NC+ PTx_SC
PTx_Common
PRx_Own_DL
PRx_Other_DL
iDL = PRx_Other_DL / PRx_Own_DL
PTx_SC the power caused by the semi-controllable traffic of real-time users (PS streaming). Before RU10 semi-controllable traffic has not been separated from the non-controllable traffic, so for those releases it is equal to zero.
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11 Nokia Siemens Networks RN31634EN40GLA0
Radio Interface Load
The BTS measures the total received power (PrxTotal) and the total transmitted power
(PtxTotal) on cell basis
The BTS reports PrxTotal & PtxTotal of each cell to the RNC
LC updates
Cell load status for each cell based on RADIO RESOURCE INDICATION
Non-controllable UL (PrxNC) & DL (PtxNC) load in cell
Semi-controllable UL (Prx_SC) & DL (Ptx_SC) load in the cell (related to PS Streaming)
AC and PS algorithms work on the current cell load status provided by LC
Denying call admission (AC) & throttling back NRT traffic (PS) are the overload actions
After scheduling PS provides LC with PrxNRT, PtxNRT & LNRT estimates
After admitting RT RAB, AC provides LC with NC load increase estimate
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12 Nokia Siemens Networks RN31634EN40GLA0
System Noise & PrxNoise Auto-tuning Algorithm
System noise PrxNoise is the sum of all stationary noises: thermal noise
interference caused by spurious emissions of other systems,
noise caused by additional equipment such as repeaters
PrxNoise can vary place to place & even time to time
PrxNoise setting affects the capacity of cell: PrxNoise too low: overestimation of cell load and can lead to unnecessary call blocking
PrxNoise too high: underestimation of cell load and can lead to overload situation
RNC provides Autotuning-Tool to measure unloaded system noise:
PrxUnloaded; it adjusts PrxNoise parameter based on these measurements
PrxTotal = PrxUnloaded when own cell considered unloaded / very low load;
LRT UnloadedRT & LNRT UnloadedNRT & no EDCH users in the cell
UnloadedRT & UnloadedNRT are RNC parameters (default values for NRT: 1 %, RT: 2 %)
LRT & LNRT: UL load factor for own cell RT (AC estimates) & NRT users (PS estimates)
PrxNoise updated by the autotuning algorithm based on PrxUnloaded
PrxNoise autotuning step size limited by PrxNoiseMaxTuneAbsolute
PrxNoise WCEL: -130..-50; 0.1; -105 dBm
PrxNoiseAutotuning WCEL: 0 (Off) / 1 (On)
PrxNoiseMaxTuneAbsolute WAC: 0..60; 0.5; 255 dB
255 dB: Autotuning is not limited
UnloadedRT RNC: 0..0.1; 0.01; 0.02
UnloadedNRT RNC: 0..0.1; 0.01; 0.01
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13 Nokia Siemens Networks RN31634EN40GLA0
UL Preventive & Overload Thresholds
Prx Target [dB]
PrxTarget [dB] + PrxOffset [dB]
load factor h
Range [0..1]
N
ois
e R
ise
[d
B]
Overloaded Area
Marginal Load Area
Feasible Load Area
PrxTarget: WCEL; 0 .. 30; 0.1; 4dB
PrxOffset: WCEL; 0 .. 6; 0.1; 1dB
dBLog h-- 110 10PrxTarget =
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14 Nokia Siemens Networks RN31634EN40GLA0
DL Preventive & Overload Thresholds
Ptx Target [dBm]
Ptx Target [dBm] + PtxOffset [dB]
load factor h
Range [0..1]
To
tal tr
an
sm
itte
d
po
we
r P
tx T
ota
l [d
Bm
]
Overloaded Area
Marginal Load Area
Feasible Load Area
Cell Maximum
PtxTarget: WCEL; -10 .. 50; 0.1; 40 dBm
PtxOffset: WCEL; 0 .. 6; 0.1; 1dB
PtxCellMax WCEL: 050; 0.1; 43dBm
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15 Nokia Siemens Networks RN31634EN40GLA0
Load Control
Load Control Functions
Radio Interface Load
Power based Radio Resource Management
Throughput based Radio Resource Management
Planning thresholds for cell loading
BTS Measurements and Reporting
Common Measurements
Dedicated Measurements
Filtering of Measurements
Automatic Access Class Restriction
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16 Nokia Siemens Networks RN31634EN40GLA0
Common measurements taken & reported by WBTS
PtxTotal Transmitted Carrier Power
Nokia Private NBAP
PtxNonHSPATransmitted Code Power of all codes not used for HSDPA
Nokia Private NBAP
PrxTotal Received Total Wideband Power
Nokia Private NBAP
REPS Received E-DCH Power Share
Nokia Private NBAP
Acknowledged PRACH preambles
Nokia Private NBAP
Provided HSDPA Bitrate
Provided HSUPA Bitrate
Required Power
RRM in RNC needs this information for Streaming mapped on HSPA
(NST Non Scheduled Transmission)
Nokia Private part is protocol extension specified in 3GPP
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WBTS Common Measurements sent to CRNC
WBTS sends measurements periodically according setting of RRM parameter:
(Nokia Private part)
RADIO RESOURCE MEASUREMENT REPORT
RRIndPeriod
Radio Resource Indication Period
WBTS; 200 .. 2000; 100; 400 ms
RACHloadIndicationPeriod
WBTS; 0 (Off); 1 .. 20; 1; 1 RRI report
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Measurement filtering
The RNC can order BTSs to report cell-based & connection-based measurements only if internal thresholds are exceeded.
However, a report is sent at least once per 10 reporting periods (RNP parameters).
The filtering functionality decreases the amount of measurement messages between the BTS and the RNC and thus decreases the load of RNC computer units.
Internally RNC repeats the cell based measurements every WBTS: RRIndPeriod to provide RRM functions a continuous flow of measurements
BTS Measurements
Reporting period
10 * Reporting period
RRIndPeriod WBTS; 200 .. 2000;
100; 400 ms
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WBTS Measurements sent to CRNC
WBTS can filter a measurement report (not sent to RNC)
only inform RNC about important load changes
reduce common NBAP signaling on IuB interface
RNC provides load threshold and value change threshold to WBTS
Measured entity
Max amount of
consecutive filtered
reports
Reporting period
Change threshold
Load Threshold
Report Report Report Report Time ReportReport
Parameter settings for
PtxTotal Measurement
0,5 dB
20 % of Ptx max
non-configurable:
PtxTotalLoadThreshold: 20%
PtxTotalChangeThreshold: 0.5dB
PrxTotalChangeThreshold: 0.2dB
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20 Nokia Siemens Networks RN31634EN40GLA0
Dedicated Measurements in BTS
Transmitted Code Power
WBTS send periodic measurement reports with code power measurement results from all Radio Links (UEs in Cell_DCH)
Depending on allocated service type WBTS applies different reporting frequency:
CS Services & SRB:
CS Data Services:
PS Data Services:
DedicatedMeasReportPeriod WBTS; 0.5..5; 0.5; 2.5 s
DediMeasRepPeriodCSdata WBTS; 0.5..5; 0.5; 1.5 s
DediMeasRepPeriodPSdata WBTS; 0.5..5; 0.5; 0.5 s
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21 Nokia Siemens Networks RN31634EN40GLA0
Load Control
Load Control Functions
Radio Interface Load
Power based Radio Resource Management
Throughput based Radio Resource Management
Planning thresholds for cell loading
BTS Measurements and Reporting
Common Measurements
Dedicated Measurements
Filtering of Measurements
Automatic Access Class Restriction
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22 Nokia Siemens Networks RN31634EN40GLA0
Automatic Access Class Restriction
Automatic Access Class Restriction allows limiting access to the network in overload conditions for a number of UE to reduce control plane and user plane
traffic
The access class for every UE is a randomly allocated digit from 0 to 9, stored in the SIM/USIM
The feature sets automatically and dynamically a number of the access classes to a barring state (by default all the UE access classes 0,...,9 are allowed for
accessing the network) if severe overload conditions occur
The number of access classes is automatically increased or decreased as the overload condition continues or respectively relaxes
Barred Access Classes can be cycled to avoid specific subscribers from being barred for long periods of time
Individual Access Classes can be barred by listing them within SIB3
It returns the system to normal state once the overload conditions are over
Access Class 10 is reserved to indicates whether or not network access for Emergency Calls is allowed for UEs with access classes 0 to 9 or an without
IMSI
The feature can be activated by turning on the Long Term ON/OFF license key Automatic Access Class Restriction and RNC level radio network planning
parameter AutoACResEnabled
Public
Subscribers
- PLMN Use
- Security Services
- Public Utilities
- PLMN Staff
- Emergency Calls
- Emergency Services
Barred AC
NEW
SLIDE
AutoACResEnabled RNFC; Bit 0: Received total wideband power ,
Bit 1: NRT scheduling queue length , Bit 2: CN overload , Bit 3: RNC overload; 0
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23 Nokia Siemens Networks RN31634EN40GLA0
Automatic Access Class Restriction
The feature introduces following new parameters:
o RNFC: AutoACResEnabled
o WCEL: AutoACResULOLThr
o WCEL: AutoACDSACRestriction
o RNAC: AutoACRLevelUpdInt
o RNAC: AutoACRestForCellPCH
o RNAC: AutoACRTrigRNCLoad
A smooth, automatic overload control in UTRAN
Avoidance of dramatic overload toggling at the core network
Increasing the successful traffic share in case of core network overload
Management parameters are replaced by an automatic functionality (OPEX savings)
Limitation to minimum of the amount of subscribers affected in case overload condition occurrence
Parameterization
o RNAC: AutoACMaxRestLevel
o RNAC: AutoACIncRestHysRTWP
o RNAC: AutoACDecRestHysRTWP
o RNAC: AutoACIncRestHysNRTQ
o RNAC: AutoACDecRestHysNRTQ
Benefits
NEW
SLIDE