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Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Power Control
Page2Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. Power Control Overview
2. HWⅠPower Control
3. HWⅡPower Control
Page3Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Power Control Overview
Power control
Adjust the transmitting power of BTS and MS when
needed.
Based on measurement reports of BTS and MS
Purpose
Save the power of BTS and MS
Reduce the interference of the network
Increase the quality of the network
Page4Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Power Control Overview Power control includes uplink power control and
downlink power control, Which are performed
independently
Uplink power control: Adjust TX power of MS to let BTS
receive stable signal, reduce the uplink co-channel and
adjacent channel interference, reduce power consumption
of MS
Downlink power control: Adjust BTS TX power to let MS
receive stable signal, reduce the downlink co-channel and
adjacent channel interference, reduce power consumption
of BTS
Page5Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Power Control Overview
Process of power control commands
It takes 3 measurement report periods(480ms/period)
from command sending to execution.
SA0 SA1SA0 SA0SA1SA1 SA2SA2SA2 SA3SA3SA3
BTS sends the command for power control and TA in SACCH header.
MS obtains SACCH block
MS begins to send the measurement report of the last multi-frame.
In the 26 multi-frames, frame 12 sends SACCH.
BTS receives the measurement report
SACCCH report period: 26X4=104 frames (480ms)
MS adopts the new power level and TA
MS begins to set up a new SACCH header to report the new TA and power control message.
Page6Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Power Control Overview
Huawei power control algorithm: HW I and HW II power control
Measurement report pre-processing
Power control
algorithm selection
HW I power control
algorithm
HW II power control
algorithm
GSM0508 power control
algorithm
Page7Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Power Control Overview Power control judgment and the selection of HWI algorithm or
HWII algorithm
Power control algorithm selected in power control data table
Power control judgment is controlled by BTS measurement report
pre-processing item which can be selected in handover control
data table
MR. Pre-process (measurement report pre-processing): This switch
decide where power control be processed. If measurement report
pre-processing is “yes”, power control is processed in BTS, and
when setting it “no”, power control is processed in BSC
Page8Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. Power Control Overview
2. HWⅠPower Control
3. HWⅡPower Control
Page9Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I Power Control
HW I power control
Process of HW I power control
MR pre-processing
Data configuration for HW I power control
Comparison of uplink power control with downlink power
control
Page10Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Process of HW I power control
Measurement report pre-processing
Aim achieved
Power control calculation and adjustment
N
Y
HW I Power ControlHW I Power Control
Page11Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Original data of power control -- measurement report
Network
Downlink Downlink measurement measurement
reportreport
Uplink MRUplink MR
BTS
HW I Power ControlHW I Power Control
Page12Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Uplink Uplink measurement measurement
reportreport
Downlink Downlink measurement measurement
reportreport
HW I Power ControlHW I Power Control Measurement report
Page13Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Measurement report pre-processing -- interpolation
Each measurement report has a serial number. When the serial
numbers are discontinuous, this indicates that some
measurement reports must be missed. In this case, the network
will fill up the measurement report according to interpolation
algorithm.
MR MR MR MR MR
Measurement report serial number n
Measurement report serial number n+4
Consecutive measurement report flow
3 missing measurement reports3 missing measurement reports
HW I Power ControlHW I Power Control
Page14Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Measurement report pre-processing -- filtering
Calculate average results of several consecutive
measurement reports to obtain the current
information, reduce the influence of some abnormal
measurement reports for the judgment of power
control.
MR MR
MR
MR
MR MR
Consecutive measurement report flow
FilterFilter
HW I Power ControlHW I Power Control
Page15Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I power control judgment (Stable adjustment stage)
Transmitting power adjustment =
(expected stable uplink or downlink RXLEV – actual uplink or
downlink RXLEV) * uplink or downlink RXLEV compensation
factor + (actual uplink or downlink RXQUAL - expected uplink or
downlink RXQUAL)*10* uplink or downlink quality compensation
factor
The final adjustment power level should not exceed the
maximum power control step size
Final stable level = current level + transmitting power
adjustment
HW I Power ControlHW I Power Control
Page16Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I Power Control
HW I power control judgment (Initial adjustment stage) Transmitting power adjustment = (actual initial RXLEV – expec
ted initial RXLEV) * uplink RXLEV compensation factor
Final transmitting power = initial RXLEV – transmitting power adjustment
If the RXLEV lower than the expected initial RXLEV, power control will not occur within initial adjustment stage
Page17Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
[BTS power control table][BTS power control table]
HW I Power Control Configuration HW I power control data configuration and parameter
introduction
Parameter name
Meaning Value range
Recommended value
DL RX_LEV Expected
The expected signal level of MS in stable status, Expected stable downlink signal level > downlink edge HO threshold,Otherwise, ping-pang HO will be caused.
0~63 (-110 dBm– -47 dBm)
35
DL RX_LEV Compensati
on
The power adjustment value varies with this parameter. The adjustment value caused by power level equal to the difference between the expected signal level and the actual receiving signal level multiply this factor.
0~100%
80% (signal ex-signal
rx)*80%=adjustment value
DL Qual. Expected
Expected signal quality of MS in stable status. 0~7
Levels 1
DL Qual.Comp
ensation
The power adjustment value varies with this parameter. The adjustment value caused by signal quality equal to 10*difference between the expected signal quality level and the actual receiving signal quality level multiply this factor.
0~100%
20% [10*(quality RX-quality EX)*20%]
MAX PC Step
Maximum adjustment range in one BTS power control command
Levels 0~16,
2dB each step
8
Page18Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I Power Control Configuration[BTS power control table][BTS power control table]
Parameter name
Meaning Value range Recommended
value BTS PC Period
Time interval for implementing two power control commands (unit count of SACCH period)
1~10 5
Filter length for DL
RX_LEV
Content: indicating the number of measurement reports in which the average of uplink signal strength is taken before MS power adjustment at stable stage. The purpose is to remove the influence of some abnormal reports. When the filter length is too long, the influence due to abnormal reports will be weakened, but the MS power adjustment is not timely.
1~32 5
BTS Min Tx power
Indicating the minimum transmitting power allowed by the base station. No matter what the original base station power is, how many levels it can be down-tuned, the transmitting power of the base station cannot be lower than this value.
0~36dBm 4
PC Adj. Range
Indicating the maximum level the base station dynamic power can be adjusted
1~16, corresponding
to 0~30dB 16
Page19Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
[MS power control data table][MS power control data table]
HW I Power Control Configuration
Parameter name
Meaning Value range Recom-mended
value Initial
RX_LEV expected
The expected BTS receiving signal level in the initial stage when MS access the network. 0~63
(-110 dBm – -47 dBm) 30
Stable EX_LEV Expected
The expected BTS receiving signal level in stable status. Expected stable signal level > uplink margin HO threshold (HO parameter). Otherwise, “ping-pang” HO will be caused.
0~63 (-110 dBm – -47 dBm) 30
UL RX_LEV compensati
on
Give an adjustment for the power control level value, the actual power level value MS should change is the result of this parameter multiply the difference between the expected uplink signal level and the actual BTS receiving signal level.
0~100% 80%
UL Qual. Expected
The expected BTS receiving signal quality in stable status.
UL Qual. compensat
ion
The power adjustment value varies with this parameter. The adjustment value caused by signal quality equal to 10*difference between the expected signal quality level and the actual receiving signal quality level times this factor.
0~100% 20%
Max PC step
The maximum level of MS power that can be dynamically adjusted.
Level 1~16, 2dB/level.
8
Page20Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameter name Meaning Value
range Value recommended
PC interval Time interval between the implementations of two power control algorithms; unit: SACCH period
0~30 5
Filter length for Initial RX_LEV
This is the number of measurement reports required for predicting the signal strength at the initial stage. Unit: Measurement reports
1~32 2
Filter length for stable RX_LEV
This is the number of measurement reports required for predicting the signal strength at the stable power control stage. Unit: Measurement reports
1-31 5
Filter length for Qual.
This is the number of the measurement reports required for assessing signal quality at the stable stage. Unit: Number of measurement reports
1~30 6
[MS power control table][MS power control table]
HW I Power Control ConfigurationHW I Power Control Configuration
Page21Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I Power Control
Power control will not occur in case of these four
conditions
Both level and quality equal to the setting values (HW I
power control), or level and quality are within threshold
band(HW II power control)
Adjusting range for MS less than error tolerance
Adjusting range less than minimum power control step of BTS
The RXLEV lower than the expected initial RXLEV within initial
adjustment stage
Page22Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I Power Control HW I power control judgment
Before judging the signal level to be adjusted, query the error
tolerance table according to the current transmitting power
level. Adjustment will not be done if the power adjustment
value is less than the error tolerance value.
Error tolerance table for 900M and 1800M is as follows:1800M:
Level 0 1 2 3 4 5 6 7 8 9 10 11
12 13 14
15 16
17 18
19
Error tolerance
2 2 2 2 2 2 2 2 2 3 3 3 3 3 4 4 4 2 2 2
900M:
Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
17 18
19
Error tolerance
2 2 2 4 4 4 4 4 4 4 4 4 4 4 4 4 6 6 6 6
Page23Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I Power Control
Comparison uplink and downlink of HW I power control .
Similarity:
1. To avoid frequently changes of signal level, the PC interval time
between the two consecutive uplink and downlink power control
are limited.
2. To reduce the influence caused by abnormal reports, all
measurement reports should be filtered.
3. Both uplink and downlink power controls include level-specific
and quality-specific power controls.
4. Both uplink and downlink power controls have maximum power
control step size limit and compensating factor.
Page24Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Comparison uplink and downlink of HW I power control .
Differentia:
1. Including power control for the stable stage, MS also has
power control when MS access the network, thus to reduce
transmitting power of MS as soon as possible.
2. For uplink, precautions are ready for increase MS
transmitting power in case HO fails.
3. For downlink, there are maximum and minimum
transmitting power limits in power control data configuration.
4. MS has the error tolerance table.
HW I Power ControlHW I Power Control
Page25Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I power control exercise Given conditions:
900M MS transmitting at the maximum power, uplink receiving level of the 900M BTS is –60dBm, uplink quality level is always 0.
Parameter configuration in [BTS power/MS power control table] is as follows – “stable RX_LEV Expected” is 35, “UL RX_LEV Compensation” is 80, “UL Qual. expected ” is 1, and “UL Qual. compensation” is 20, and the max. PC step is 16dB.
HW I Power ControlHW I Power Control
Page26Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I power control exercise
Question:
1. Suppose that power control will no longer be done once
the power value to be adjusted is less than 2dB, what is
the approximate stable power value after power control
with the above data configuration?
2. According to the error tolerance list, suppose the initial
MS transmitting power is level 3, what is the maximum
uplink receiving level in stable status after power control?
ExerciseExercise
Page27Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW I power control exercise
Answers for question 1: Stable level = current actual level + [(expected signal intensity in stable statu
s – current actual level) * uplink path loss compensating factor] + [actual current quality – expected uplink signal quality) * 10 * uplink quality compensating factor] = -60+[(-75-(-60))*80 % ]+[(0-1)*10*20 % ] = -60-12-2 = -74dBm. Now it’s necessary to adjust -14dB (no larger than the maximum power control step size), but it needs further adjustment because it fails to reach -75dBm, the “expected signal level in stable status”. Use -74 in the above formula again for calculation, and the power to be adjusted is -2.8dB. Because no power control adjustment will be done when the power value to be adjusted is smaller than -2, it still needs to be changed 2dB lower, so the uplink receiving level is -76dBm at last.
ExerciseExercise
Page28Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Answers for question 2:
Query the error tolerance table, the tolerance of level 3 is
4dB, the power to be adjusted for the second time is 2.8,
which is less than 4 and up to the requirement, so the
final uplink receiving level is -74dBm in stable status.
ExerciseExercise
Page29Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. Power Control Overview
2. HWⅠPower Control
3. HWⅡPower Control
Page30Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control
Power control judgment process
Measurement report pre-processing
The power control demand according to the
receiving level
Send the power control command
The power control demand according to receiving quality
General power control judgement
Page31Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Measurement report compensation
Purpose: Ensure the accuracy of selection of the history measurement report before filtering.
Implementation steps: 1. Put the current receiving measurement report into the
measurement report compensation queue.
2. Record the changed information of the transmitting power according to the MS and BTS power levels in the measurement report.
3. After finish the measurement report interpolation, system will compensate the receiving level of the history measurement report according to the power change information. The compensated measurement reports will be the original data in the filter process.
4. Filter the compensated measurement reports.
Page32Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Measurement report compensation
The expected receiving signal level: 30
The power control will be more effective with measurement report compensation.
The expected receiving signal level: 30
The power control will be more effective with measurement report compensation.
X axis
1 2 3 4 5 6 7 8 910
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500
10
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Y a
xis
Power control diagram when there is measurement report compensation
Diagram when there is no power control
Power control diagram when there is no measurement report compensation
Power control effect diagram of measurement report compensation
Page33Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Measurement report prediction
Purpose: Avoid power control later than needed, the delay
is dangerous in case of poor level or bad quality
Implementation procedure
1. Analyze the tendency of MR by the historical measurement
reports after interpolation.
2. Guide by the tendency, to predict the values of
measurement report to be received. There are 0~3
measurement reports prediction, which are configured on
OMC.
3. Filter the interpolated, compensated and predicted
measurement reports, and implement power control judgment.
Page34Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Measurement report prediction
1 2 3 4 5 6 7 8 910
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15
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Y a
xis
No power control
Mean filter power control
Prediction filter power control
Diagram of power control effect comparison between prediction filter and mean filter
The expected receiving signal level: 30
The power control with prediction filter will be more effective than that with mean filter
The expected receiving signal level: 30
The power control with prediction filter will be more effective than that with mean filter
Page35Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Implementation Power control demand based on receiving level.
After measurement report pre-processing, the power
control module makes a comparison between the expected
signal level and the current receiving signal level.
Calculate the transmitting power level step size to be
adjusted, making the receiving level value closer to the
expected value.
Adopt variable step size when adjusting the transmitting
power according to the receiving level, so as to achieve the
expected level as soon as possible.
Page36Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Implementation Power control demand based on receiving quality
After measurement report pre-processing, the power control
module makes comparison between the expected quality level
and the current receiving quality level.
Calculate the step size of the transmitting power level to be
adjusted.
Increase the transmitting power in case of poor receiving quality.
Decrease the transmitting power in case of good receiving quality.
Adopt fixed step size when adjust the transmitting power
according to the receiving quality.
Page37Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Implementation General power control judgment
Power control by receiving
level
Power control by receiving
quality
Power control by signal level and
quality
↓ AdjStep_Lev ↓ AdjStep_Qul ↓ max(AdjStep_Lev,AdjStep_Qul)
↓ AdjStep_Lev ↑ AdjStep_Qul No action
↓ AdjStep_Lev No action ↓ AdjStep_Lev
↑ AdjStep_Lev ↓ AdjStep_Qul ↑ AdjStep_Lev
↑ AdjStep_Lev ↑ AdjStep_Qul ↑ max(AdjStep_Lev,AdjStep_Qul)
↑ AdjStep_Lev No action ↑ AdjStep_Lev
No action ↓ AdjStep_Qul ↓ AdjStep_A
No action ↑ AdjStep_Qul ↑ AdjStep_B
No action No action No action
Page38Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Feature Adaptive power control:
Adaptive power control refers to changeable power control
strategy according to the communication environment, it
makes power control more effective and stable.
Automatically change the adjustable maximum step size of
power control according to different communication
environment (different receiving quality).
Adopt different power control strategies according to different
communication environments (different receiving quality and
level).
Max. step is different between increase and decrease.
Page39Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Feature
Power control within the upper/lower thresholds
As for HW II power control in case of calculating power
control step size according to signal level and quality, the
signal level and quality have upper/lower thresholds.
Power control will not execute if the signal level and
quality is within the threshold bands.
Avoid the signal level up-and-down caused by power
control.
The upper threshold can be increased dynamically in case
of bad quality.
Page40Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Measurement report compensation -- makes power
control judgment more accurate
Measurement report prediction --to avoid power
control later than needed, the delay is dangerous in
case of poor level or bad quality
Power control expected signal level and quality
threshold falls within a band, this avoids receiving
signal level fluctuate up and down frequently
HW II Power Control Advantages
Page41Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Configuration[HW II power control table] main parameters – 1 [HW II power control table] main parameters – 1
Parameter name
Meaning Value range
Recommended value
filter length for UL
RX_LEV
How many uplink measurement reports obtained for the average uplink signal level to be used for uplink power control adjustment.
1~20 6
filter length for DL
RX_LEV
How many downlink measurement reports obtained for the average downlink signal level to be used for downlink power control adjustment.
1~20 6
filter length for UL Qual.
How many uplink measurement reports obtained for the average uplink quality level to be used for uplink power control adjustment.
1~20 6
filter length for DL Qual.
How many downlink measurement reports obtained for the average downlink quality level to be used for downlink power control adjustment.
1~20 6
MR compensation
allowed
If “yes”, System put the currently received measurement report into the measurement report compensation queue, and record the transmitting power information according to MS and BTS power values. And then interpolation, compensate the receiving level value of the record measurement report according to the power change information.
Yes, no Yes
UL MR number
predicted
The number of uplink pred. MR in the filter using for power control judgment.
0~3 reports
2
DL MR number
predicted
The number of downlink pred. MR in the filter using for power control judgment.
0~3 reports
2
Page42Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Configuration[HW II power control table] main parameters – 2[HW II power control table] main parameters – 2
Parameter name
Meaning Value range
Recommended value
PC interval Time between two power control command implementation 1~30
(SACCH period)
5
UL RX_LEV upper
threshold
This parameter specifies the uplink signal level upper threshold. When the signal level higher than this value, calculate a power
decrement [=receiving level - (upper threshold + lower threshold)/2]. This decrement value should consider together with
the maximum step size allowed for different quality zone which the receiving signal quality located.
0~63 (-110 dBm – -47 dBm)
35
UL RX_LEV lower
threshold
This parameter specifies the uplink signal level lower threshold. When the signal level lower than this value, calculate a power
increase [= (upper threshold + lower threshold)/2- receiving level]. This increase also consider together with the maximum step size
allowed for different quality zone which the receiving signal quality located.
0~63 (-110 dBm – -47 dBm)
25
UL Qual. upper
threshold This parameter specifies the uplink quality upper threshold.
Level 0~7
0
UL Qual. lower
threshold
This parameter specifies the uplink quality lower threshold for power control
Level 0~7
2
Page43Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Configuration[HW II power control table] main parameters [HW II power control table] main parameters –– 33
Parameter name
Meaning Value range
Recommended value
DL RX_LEV upper threshold
This parameter specifies the downlink signal level upper threshold. When the signal level higher than this value, calculate a power decrement [=receiving level – (upper threshold + lower threshold)/2]. This decrement should consider together with the maximum step size allowed for different quality zone which the receiving signal quality located.
0~63 (-110 dBm –
-47 dBm) 40
DL EX_LEV lower threshold
This parameter specifies the downlink signal level lower threshold. When the signal level lower than this value, calculate a power increase [= (upper threshold + lower threshold)/2- receiving level]. This increase also consider together with the maximum step size allowed for different quality zone which the receiving signal quality located.
0~63 (-110 dBm –
-47 dBm) 30
DL Qual. upper threshold
This parameter specifies the downlink quality upper threshold for power control
Level 0~7 0
DL Qual. lower threshold
This parameter specifies the downlink quality lower threshold for power control
Level 0~7 2
Page44Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
[HW II power control table] main parameters [HW II power control table] main parameters –– 44Parameter
name Meaning Value range
Recommended value
MAX Down Adj. value Qual.
zone 0
This parameter specifies the maximum downward power adjustment value when the Rx quality is 0.
0~30dB 16
MAX Down Adj. value Qual.
zone 1
This parameter specifies the maximum downward power adjustment value when the Rx quality is 1 or
2 0~30dB 8
MAX Down Adj. value Qual.
zone 2
This parameter specifies the maximum downward power adjustment value when the Rx quality is
equal to or more than 3. 0~30dB 4
MAX Down Adj. PC Value by
Qual.
The adjustment step allowed for the downward power control due to receiving signal quality.
0~4dB 4
HW II Power Control Configuration
Page45Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Configuration[HW II power control table] main parameters [HW II power control table] main parameters –– 55
Parameter name
Meaning Value range Recommended
value
MAX Up Adj. PC Value by
RX_LEV
It is used to set the maximum adjustment step for upward power control by receive level.
0~32dB 16
MAX Up Adj. PC Value by
Qual.
It is used to set the maximum adjustment step for upward power control by receive quality.
0~32dB 8
UL Qual. Bad TrigThrsh
In uplink power control, when the receiving quality of uplink is not less than this start threshold, the
actual "upper threshold of signal strength of uplink" will be added with "upper threshold offset of level when the receiving quality of uplink is poor" in the
data configuration. Thus, the expected level in uplink power control can be increased furthermore.
0~7 5
UL Qual. Bad UpLEVDiff
In uplink power control, when the receiving quality is not less than "start threshold when the receiving
quality of uplink is poor", the actual "upper threshold of signal strength of uplink" will be added with this
offset value.
0~63dB 0
Page46Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Power Control Configuration[HW II power control table] main parameters [HW II power control table] main parameters –– 66
Parameter name
Meaning Value range Recommended
value
DL Qual. Bad TrigThrsh
In downlink power control, when the receiving quality of downlink is not less than this start
threshold, the actual "upper threshold of signal strength of downlink" will be added with "upper
threshold offset of level when the receiving quality of downlink is poor" in the data configuration. Thus, the expected level in downlink power control can be
increased furthermore.
0~7 5
DL Qual. Bad UpLEVDiff
In downlink power control, when the receiving quality is not less than "start threshold when the receiving quality of downlink is poor", the actual
"upper threshold of signal strength of downlink" will be added with this offset value.
0~63dB 0
Page47Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Exercises for HW II power control
Given conditions: The uplink receiving level is -55dBm, the quality is level 0. Power
control algorithm is HW II.
Data configuration is as follows: Uplink signal level upper threshold: -60dBm, uplink signal level lower threshold: - 80dBm. Uplink signal upper quality threshold: level 1. Uplink signal lower quality threshold: level 2. The downward adjustable step size of quality band 0 is 16dB, of quality band 1 is 8dB, and of quality 2 is 4 dB. The upward adjustable step size of receiving level is 16dB. The upward or downward adjustable step size for power control by quality are both 4dB.
Question: What will be the uplink stable receiving level after power control?
ExerciseExercise
Page48Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Exercise Exercises for HW II power control
Answer. First, transmitting power to be reduced according to receiving level = a
ctual receiving level -(uplink signal level upper threshold + uplink signal level lower threshold)/2 = -55- (-60 + (-80))/2 = (-55)-(-70) = 15dB. As the receiving quality is level 0, downward adjustable step size of quality band 0 can be used -- decrease 16dB.
Second, the transmitting power to be decreased according to receiving quality = as “power control adjustment step size by quality” is 4dB, thus decrease 4dB.
Therefore, according to the general judgement on power control, 15dB should be decreased.
Page49Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Exercise
Exercises for HW II power control
Answer .
After the implementation of step 1 power control, the
receiving level becomes: -55dBm-15dB= -70dBm, Suppose
the quality reach already in level 1 here.
First: the receiving level value is between -80dBm~-60dBm,
needn’t adjust.
Second: the receiving quality value is between 0 and 2,
needn’t adjust.
Therefore, the uplink stable receiving level =-70dBm.
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