Background Noise Measurement Methods comparisons for Huawei, NSN and Ericsson Ajay (RF Consultant)
[email protected]
2011
Background Noise Measurement Methods comparisons for Huawei, NSN and Ericsson
1
Background Noise Measurement Methods comparisons for Huawei, NSN and Ericsson Ajay (RF Consultant)
[email protected]
2011
1.0 Background Noise Calculation Huawei
Parameter
Function
Value Range
Recommended Value
Actual Value
BgnStartTime
Sets start time when algorithm will function
hour{0~23}, min{0~59}, sec{0~59}
01&00&00
01:00:00 Hrs
BgnEndTime
Sets end time when algorithm will function
hour{0~23}, min{0~59}, sec{0~59}
06&00&00
06:00:00 Hrs
BGNEqUserNumThd
Sets ENU threshold for use in Background Noise updating
0~10
0
0
BgnAbnormalThd
Sets limit between measured RTWP and Current Background Noise
0~400
100
10 dB
BackgroundNoise
Initial value of Background Noise used in the algorithm. (If algorithm is disabled, it serves as the fixed value Background Noise of the system used in calculations)
1~621
61
-106 dBm
BgnUpdateThd
Sets the limits of variation in-between Background Noise Updates
1~100
5
0.5 dB
BGNAdjustTimeLen
Sets duration limit for measuring Background Noise
1~6000
120
120 sec
2
Background Noise Measurement Methods comparisons for Huawei, NSN and Ericsson Ajay (RF Consultant)
[email protected]
2011
2.0 Background Noise Calculation NSN Uplink noise can either be set to a fixed value at the radio network planning stage, or allowed to fluctuate according to the current conditions, with the help of an autotuning algorithm. The autotuning algorithm of Uplink noise level (PrxNoise) can be switched on or off on a cell-by-cell basis using the management parameter PrxNoise autotuning allowed (PrxNoiseAutotuning). Naturally, the uplink noise level can only be measured when the cell is unloaded, or under a very low load. Therefore, the updating of uplink noise is dependent on PrxUnloaded measurements. When the own cell is unloaded, PrxTotal is the same as PrxUnloaded. The cell is considered to be unloaded when the following conditions are met: Own cell LRT LNRT
≤ ≤
0.02 AND 0.01 AND NoEDCHUsersInCell
LRT- uplink load factor for own cell RT-users (admission control estimates) LNRT- uplink load factor for own cell NRT-users (packet scheduler estimates)
Name
Parameter Name
Object
Range
Default Value
PrxNoise
Uplink noise level
Cell
-130...-50
-105 dBm
PrxNoiseAutotuning
PrxNoise autotuning allowed
Cell
On/Off
On
Uplink noise level (PrxNoise) autotuning algorithm PrxNoiseRNP is an original noise threshold (PrxNoise) set by the operator and unaffected by the autotuning algorithm. PrxNoiseAdj is the threshold adjusted by the autotuning algorithm. This threshold is used by the radio resource management algorithms in cases where adjusting PrxNoise is allowed.
STEP 1. If the cell is loaded, PrxRef(n-1) is set to be the same as PrxNoiseAdj (<=>PrxRef(0) = PrxNoise- Adj and n= 1). In STEP 1 forgetting factor β of the mean filter with forgetting factor is selected. There are separate forgetting factors for uplink and downlink adjustments.
Step 2 In STEP2 PrxRef(n) is calculated.
Step 3 In STEP3 adjustment UP is performed if PrxRef(n) is over PrxNoise by the amount defined by Threshold for upward adjustment of system noise (PrxNoiseOffsetUp) and adjustment DOWN is performed if PrxRef(n) is below PrxNoise by the amount defined by Threshold for downward adjustment of system noise (PrxNoiseOffsetDown). The algorithm presented below uses the following values:
Parameter PrxNoiseRNP (PrxNoise) RT load threshold for system noise measurements (UnloadedRT)
Value Range and step: -130...-50 dBm, step 0.1 dBm 0.02
NRT load threshold for system noise measurements (UnloadedNRT)
0.01
Threshold for upward adjustment of system noise (PrxNoiseOffsetUp)
0.1 dB
Threshold for downward adjustment of system noise (PrxNoiseOffsetDown) Maximum adjustment step for upward adjustment of system noise (PrxNoiseStepUp) Maximum adjustment step for downward adjustment of system noise (PrxNoiseStepDown) Forgetting factor for upward adjustment of system noise (2_up) Forgetting factor for downward adjustment of system noise (2_down)
-0.1 dB 0.3 -0.3 0.05 0.1
#START Prx_ref(0):=PrxNoiseRNP Prx_NoiseAdj:=PrxNoiseRNP n:=1 # RADIO RESOURCE INDICATION received. IF (Lrt > RTunloaded)OR(Lnrt > NRTunloaded)OR(OneOrMoreEDCHUsersInCell) THEN Prx_ref(0):=PrxNoiseAdj n:=1 3
Background Noise Measurement Methods comparisons for Huawei, NSN and Ericsson Ajay (RF Consultant)
[email protected]
ELSE PrxUnloaded:=PrxTotal #STEP_1 IF PrxUnloaded ≥ PrxNoiseAdj THEN β:=β_UP ELSE β:=β_DOWN ENDIF #STEP_2 Prx_ref(n):=β*PrxUnloaded+(1–β)*Prx_Ref(n-1) #STEP_3 IF (Prx_ref(n)) ≥ PrxNoiseAdj + PrxNoiseOffsetUP THEN AdjStepUp:=MIN(((Prx_ref(n))— PrxNoiseAdj), PrxNoiseStepUP) PrxNoiseAdj:=PrxNoiseAdj + AdjStepUp Prx_ref(0):=PrxNoiseAdj n:=1 ELSE IF Prx_ref(n)) ≤ PrxNoiseAdj + PrxNoiseOffsetDown THEN AdjStepDown:=Max(((Prx_ref(n) - PrxNoiseAdj), PrxNoiseStepDown) PrxNoiseAdj:=PrxNoiseAdj + AdjStepDown Prx_ref(0):=PrxNoiseAdj n:=1 ELSE n:=n+1 ENDIF ENDIF
4
2011
Background Noise Measurement Methods comparisons for Huawei, NSN and Ericsson Ajay (RF Consultant)
[email protected]
2011
3.0 Background Noise Calculation Ericsson The thermal noise is also calculated by RTWP measurements, but selecting only those samples that represent a situation free or almost free of traffic. To do that, the load estimator collects a number of samples in a sliding window fashion, during a configurable time, eulSlidingWindowTime. A short sliding window time may cause spurious variations in the thermal noise level, a long time might be unable to capture normal variations in the thermal noise level, such as temperature drift. The calculations are facilitated by the use of prior information regarding the noise floor level, eulThermallevelPrior. This value represents the anticipated thermal noise floor level of the RBS. If the thermal noise calculation from RTWP measurements is considered unreliable, there is a possibility to lock the thermal noise level by setting the parameter eulNoiseFloorLock to “true”. This locks the thermal noise value to a value given by the parameter eulOptimalNoiseFloorEstimate. If eulOptimalNoiseFloorEstimate is set to -1 (= undefined), the thermal noise value is instead locked to either eulThermalLevelPrior (if the lock parameter is set to “true” at system start) or to the thermal noise level at that particular point in time (if the lock parameter is changed to “true” during on-going operation of RBS).
Name
Object
Range
Default Value
Recommended Value
eulSlidingWindowTime
Cell
10...864000
1800 (180 s)
72000 ( 7200 s)
eulThermalLevelPrior eulNoiseFloorLock eulOptimalNoiseFloorEstimate eulMaxRotCoverage eulMaxTargetRtwp eulMaxOwnUuLoad
Cell Cell Cell Cell Cell Cell
-1150...-600 True/False -1150 – -600, -1 0...550 -1120..-499 0...550
-1040 (-104 dbm) False -1040 (-104 dbm) 100 (10db) -499 (-49.9 dbm) 30 (3db)
-1040 (-104 dbm) -1040 (-104 dbm) -499 (-49.9 dbm) 80 (8 db)
eulMaxRotCoverage Defines the maximum RoT level that is allowed to preserve coverage (includes all uplink Traffic and External interference). eulMaxOwnUuLoad Defines the maximum allowed power -controlled noise (includes power-controlled RoT including contributions from all uplink traffic) in own cell. eulMaxTargetRtwp Maximum allowed Received Total W ideband Power (RTW P) for the RBSscheduler for EUL.
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