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ZGO-04-02-001 Dynamic BTS

Power Control

Feature Guide



ZGO-04-02-001 Dynamic BTS Power Control

ZTE Confidential Proprietary © 2010 ZTE CORPORATION. All rights reserved. I


Version Date Author Approved By Remarks

V1.00 2010-10-30 Not open to the Third Party

© 2010 ZTE Corporation. All rights reserved.

ZTE CONFIDENTIAL: This document contains proprietary information of ZTE and is not to bedisclosed or used without the prior written permission of ZTE.

Due to update and improvement of ZTE products and technologies, information in this document issubjected to change without notice.




ZTE Confidential Proprietary © 2010 ZTE CORPORATION. All rights reserved. II

TABLE OF CONTENTS

1

Feature Attribution ......................................................................................... 1

2

Overview ......................................................................................................... 1

2.1

Feature Introduction .......................................................................................... 1

2.2

Correlation with Other Features ........................................................................ 2

3

Technical Description .................................................................................... 2

4

Parameters and Configurations................................................................... 15

4.1

Parameter List ................................................................................................ 15

4.2

Parameter Configurations ............................................................................... 25

5

Related Counters and Alarms ...................................................................... 32

5.1

Related Counters ............................................................................................ 32

5.2

Related Alarms ............................................................................................... 33

6 Engineering Guide ........................................................................................ 33

6.1

Application Scenarios ..................................................................................... 33

6.2

Configuration Description................................................................................ 33

6.3

Network Impact ............................................................................................... 33

7

Abbreviation .................................................................................................. 34

8

Reference Document .................................................................................... 34




ZTE Confidential Proprietary © 2010 ZTE CORPORATION. All rights reserved. III

FIGURES

Figure 3-1 Power Control Flow Chart ................................................................................... 4

Figure 3-2 Power control samples averaging process with windows size set as 6 ................ 5

Figure 3-3 First averaging sample ........................................................................................ 7

Figure 3-4 Second averaging sample ................................................................................... 7

Figure 3-5 Third averaging sample ....................................................................................... 8

Figure 3-6 Fast averaging process ....................................................................................... 9

Figure 3-7 Power Control Strategy ..................................................................................... 12

Figure 4-1 Power Control1 ................................................................................................. 26

Figure 4-6 Others ............................................................................................................... 31

TABLES

Table 3-1 Power Control Strategy ...................................................................................... 10

Table 3-2 Dynamic Power Definition .................................................................................. 15

Table 4-1 Parameter List .................................................................................................... 15

Table 4-2 Level Values Corresponding to Downlink Signal Strength Threshold ................. 29

Table 4-3 BER Corresponding to Downlink Signal Quality Threshold ................................. 30

Table 5-1 Related counters ................................................................................................ 32



ZTE Confidential Proprietary © 2010 ZTE CORPORATION. All rights reserved. II

Document

Title




ZTE Confidential Proprietary © 2010 ZTE CORPORATION. All rights reserved. 1

1 Feature Attribution

iBSC Version: [iBSC V6.20]

BTS Version: [For all BTS versions based on SDR platform]

Property: [Optional]

Related Network Elements and Requirements:

NE Name Related or Not Special Requirements

MS √

BTS √

BSC √

MSC -

MGW -

SGSN -

GGSN -

HLR -

Dependent Function: [None]

Exclusive Function: [None]

Note: [None]

2 Overview

2.1 Feature Introduction

Power control is important for spectrum efficiency as well as for power consumption

efficiency in a cellular system. Dynamic BTS Power Control can dynamically adjust the

BTS output power. The control algorithm uses the signal strength and quality information

in the measurement reports which are reported by the MS.





Dynamic BTS Power Control can properly adjust the output power of BTS, thus

decreasing the interference in the network.

2.2 Correlation with Other Features

The increase downlink level threshold (PcDlInclLevThs) of BTS power control should be

set higher than downlink power level threshold (HoDlLevThs),of downlink level based

handover and the increase downlink quality threshold (PCDLINCLQUALTHSThs) of BTS

power control should be set smaller than downlink quality level threshold (HoDlQualThs)

of downlink quality based handover. The purpose is to enhance the level or quality of CS

call as much as possible with power control before handover is triggered as the last way.

Attention: Power control and handover are controlled by BTS and BSC separately without

interaction with each other which means both of them will be triggered when the

thresholds of both algorithms are met because of fast signal attenuation.

Other related features include: ZGB-04-02-002 Static BTS Power Control and

ZGO-04-02-002 Dynamic MS Power Control .

3 Technical Description

BTS Power control is an important method for radio link control. The dynamic BTS power

control function with parameter PwrControlDl allows BSS to conduct dynamic control

over the output power of BTS. The transmission power of BTS is adjusted according to

an overall judgment based on downlink level and quality in the downlink measurement

report.

Power control is based on the following basic principles:

Power will be decreased appropriately when the level or quality is higher than the

expectation;

Power will be increased appropriately when the level or quality is lower than the

expectation;





Both level and quality factors should be taken into overall consideration to make power

control more accurate and effective.

Although it is the network operators that determine whether to adopt the downlink power

control function, all BTSs must support this function. According to the specifications, BTS

must have 15 steps of dynamic power adjustment with 2dB/per step which means the

dynamic power adjustment range is 30dB.

Figure 3-1 shows ZTE’s power control flow chart.





Figure 3-1 Power Control Flow Chart

Step1：BTS receives a

measurement report from MS

BEGIN

Step2：BTS saves the

measurement report from MS

Step3：BTS processes theoriginal measurement data

from MS

Step4：BTS sorts and works

out statistics of the

average date of MS

Step5：BTS power control

strategies

Step6：determining the BTS

power control step

Step7：implementing BTS

power control and resetting

power control data

END

The steps are detailed as follows:

Step 1: BTS receives a measurement report from MS.





The downlink measurement reports are sent through the SACCH in the measurement

report message. The measurement report message contains the measurement results

about the current dedicated channels and adjacent cells.

Step 2: BTS saves the measurement report from MS.

Downlink power control algorithm will extract the downlink reception level grade and

reception quality grade of the current channel from the measurement report message

and put these two grade values into their respective original cyclic queues.

Step 3: BTS processes the original measurement data from MS.

When the number of stored level and quality queues reaches their respective averaging

window size set with parameter PcDlLevWindows/PcDlQualWindows, Averaging process

will be implemented with considering the weight factor set with parameter

PcDlLevWeight/PcDlQualWeight .

For the step 1 to step 3, please check in the figure 3-2:

Figure 3-2 Power control samples averaging process with windows size set as 6

Signal Level/Quality information got from MR1

A v e r a g e

DTx=0

Weight=2

DTx=1

Weight=1

A v e r a g e S i gn al l e v e l

/ Q u al i t y

1

DTx=0

Weight=2

DTx=0

Weight=2

DTx=1

Weight=1

DTx=1

Weight=1










When the Downlink DTX is used, the proper way is to set the

PcDlLevWeight/PcDlQualWeight larger than 1 which means the measure report with DTX

on will be with weight as 1 and the measure report with DTX off will be with weight as 2 or

3 during the averaging to make sure the none DTX measure report will make more effect

on the final averaging result.

Step 4: BTS sorts and works out statistics of the average data of MS.

When the average value samples reach the threshold N, BTS will check the average

queues and works out statistics on the current level status and quality status (Whether P

sample of N averaging samples is met the threshold).

The level threshold, P and N related parameters are:

PcDLIncLevThsThs/PcDLIncLevThsP/PcDLIncLevThsN and PcDLRedLevThsThs

/PcDLRedLevThsP/PcDLRedLevThsN.

The quality threshold, P and N related parameters are:

PcDLIncQualThsThs/PcDLIncQualThsP/PcDLIncQualThsN and PcDLRedQualThsThs

/PcDLRedQualThsP/PcDLRedQualThsN.

BTS power control will use the sliding windows method to generate the N averaging

value shown in the figure 3-3 to figure 3-5 with the example that windows size is 6

and P/N is 3/3:





Figure 3-3 First averaging sample

Level/Quality information got from MR1








Average Level/Quality 1



P=3 and N=3

Figure 3-4 Second averaging sample












P=3 and N=3





Figure 3-5 Third averaging sample












P=3 and N=3

Before the averaging, only the measurement sample amount reaches the window

size can trigger the averaging. Sometimes it will cost time because the measure

report store queuing will be cleared and reset after power control per time and new

measurement reports should be re-gathered again.

To fasten the power control process and meet the requirement on the prompt BTS

power adjustment especially in the fast moving environment, the Fast average

indication (FastAve) is used which means the the first averaging will be done immediately

on the first MR received and the second averaging will be done on two MRs when the

second MR is received.

For the detail explanation, please check it in the figure 3-6 as following:





Figure 3-6 Fast averaging process

Level/Quality information got from MR1 Average Level/Quality 1

P=3 and N=3

Level/Quality information got from MR1Average Level/Quality 1




Level/Quality information got from MR2Average Level/Quality 2


Step 5: BTS power control strategies.

According to the statistic results of the level and quality status, the BTS power control

strategies are shown in the Table 1. In this table:

Level status = 0: the level grade is normal level status (between the upper and lower limit

of the expected level);

Level status = 1: the level grade is low level status (lower than the lower limit of the

expected level);

Level status = 2: the level grade is high level status (higher than the upper limit of the

expected level);

Quality status = 0: the reception quality is normal BER (between the upper and lower limit

of the expected quality);

Quality status = 1: the reception quality is low BER (lower than the lower limit of the

expected quality);





Quality status = 2: the reception quality is high BER (higher than the upper limit of the

expected quality).

Please check the power control strategy sumary list in table 3-1 shown as following:

Table 3-1 Power Control Strategy

No Level Status Quality Status Conclusion

1 0 0 Keep the original power

2 0 1Decrease the transmission power (due to

quality)

3 0 2 Increase the transmission power (due toquality)

4 1 0 Increase the transmission power (due to level)

5 1 1 Increase the transmission power (due to level)

6 1 2Increase the transmission power (due to

quality)

7 2 0 Decrease the transmission power (due to level)

8 2 1 Decrease the transmission power (due to level)

9 2 2Increase the transmission power (due to

quality)

Detailed explanations for each case mentioned in table 1 Power Control Strategy:

No 1:

When the level grade is normal level status, and the reception quality is normal BER, the

selected power control scheme is to keep the original power.

No 2:

When the level grade is normal level status, and the reception quality is low BER, the

selected power control scheme is to decrease the transmission power.

No 3:

When the level grade is normal level status, and the reception quality is high BER, the

selected power control scheme is to increase the transmission power.





No 4:

When the level grade is low level status, and the reception quality is normal BER, the


No 5:

When the level grade is low level status, and the reception quality is low BER, the


No 6:

When the level grade is low level status, and the reception quality is high BER, the


No 7:

When the level grade is high level status, and the reception quality is normal BER, the


No 8:

When the level grade is high level status, and the reception quality is low BER, the


No 9:

When the level grade is high level status, and the reception quality is high BER, the


Above 9 cases can also be descirbed in the figure 3-7 Power Control Strategy show as

following:





Figure 3-7 Power Control Strategy

No Action

Decrease Power

(Due to quality)

Increase Power

(Due to quality)

Decrease Power

(Due to level)

Decrease Power

(Due to level)

Increase Power

(Due to quality)

Increase Power

(Due to level)

Increase Power

(Due to level)

Increase Power

(Due to quality)

0

7

Quality

-110 -50 dBm

Decrease UL/DL

quality Threshold

Increase UL/DL

quality Threshold

Increase UL/DL

level Threshold

Decrease UL/DL

level Threshold

Step 6: Determining the BTS power control step.

BTS output power will be adjusted according to the dynamic BTS power control strategy.

If the power adjustment step is a fixed value set by parameter PWRINCSTEP or

PWRREDSTEP , such as 2, 4 and 6dB, this is called common power control. When the

parameter DIRapidPcInd is switched on, BTS determines whether the rapid power

control will be used according to the level or quality difference between thresold triggering

power control and measured one.

As an advantage, the rapid power control can decrease the interference of the whole

system and making a fast power control. The power control adjustment range per time by

the rapid power control is no longer a fixed value, but an integral multiple with the cell

parameter PWRINCSTEP or PWRREDSTEP .

For the power adjustment range per time of rapid power control, please refer to the

following rules. Increasing/decreasing level should be judged by some conditions. If

these conditions are not met, common power control will be used.





Increase the BTS power (due to level):

If LEV_DL + 2* INCREASESTEP < L_RXLEV_DL, there is step adjustment:

STEP = L_RXLEV_DL -LEV_DL,

LEV_DL refers to the current signal level rather than the average value; L_RXLEV_DL

refers to the lower limit of the expected level.

Decrease the transmission power (due to level):

If LEV_DL - 2* DECREASESTEP > U_LEV_DL, there is step adjustment:

STEP = min (PwrDecrLimit, LEV_DL- U_RXLEV_DL)

LEV_DL is the current value rather than the average value; U_LEV_DL refers to the

upper limit of the expected level; PwrDecrLimit idicates the maximum allowed BTS output

power decreasing set on each quality level from 0 to 7 with parameter PwrDecrLimit .

Increase the transmission power (due to quality):

If LEV_DL + 2* INCREASESTEP < L_RXLEV_DL, there is step adjustment:

STEP = max ( (1+max(0,Qa)) * INCREASESTEP , L_RXLEV_DL - LEV_DL )

Otherwise

STEP = (1+max (0,Qa)) * INCREASESTEP

Qa = QUAL_DL - L_RXQUAL_DL; QUAL_DL refers to the current signal quality and

LEV_DL refers to the current signal level, neither of them refers to the average value;

L_RXQUAL_DL refers to the upper limit of the expected quality.

Decrease the transmission power (due to quality):

Power decreasing step caused by signal quality is limited, therefore:

If LEV_DL - 2* DECREASESTEP > U_LEV_DL,

STEP = min (PwrDecrLimit, LEV_DL – U_ RXLEV_DL, (1 + max (0, Qa)) *

DECREASESTEP);





Otherwise

STEP = DECREASESTEP.

LEV_DL refers to the current signal level rather than the average value; Qa =

U_RXQUAL_DL – AV_QUAL_DL; AV_QUAL_DL refers to the average value of signal

quality.

The difference between the latest measurement report value and the threshold value will

be calculated. If the result exceeds 2 times the power control step value, rapid power

control should be conducted to adjust the measured value directly to the threshold value

at one stroke. If the value does not exceed 2 times the power control step value,

adjustment should be performed by the step defined in common power control.

Step 7: Implementing BTS power control and resetting power control data.

When the power control algorithm is used to figure out the required power, BTS will

modify its transmission power based on this information. Once the BTS output power is

changed, all the measured data and stored queues will be cleared and reset to receive

new mearsurement report for the next power control judgment process.

After each time of power control, a few more measurement reports that still use the

original transmission power or dynamically changing transmission power are likely to be

received, but the level and quality information contained is inaccurate and should be

ignored (other information, like adjacent cell information, is still valid.) Therefore, before

the next power control process starts, several measurement reports that are not accurate

enough will be ignored. The parameter PCMININTERVAL is used to specify a minimum

interval between two power control processes.

ZTE’s dynamic BTS power is divided into 16 levels: 0 to 15. Dynamic power control is an

adjustment based on static power control. Dynamic power takes one level of static power

as its maximum value, named Pn, which can be adjusted downward by up to 15 levels, at

a step of 2dB. For example, if Pn = 45dBm, the power values corresponding to its

dynamic power levels are listed in Table 3-2:





Table 3-2 Dynamic Power Definition

Dynami

c Level0 1 2 3 4 5 6 7 8 9

1

0

1

1

1

2

1

3

1

4

1

5

Power

(dBm)

4

5

4

3

4

1

3

9

3

7

3

5

3

3

3

1

2

9

2

7

2

5

2

3

2

1

1

9

1

7

1

5

Acutally, even the maximum allowed dynamic power control has 15 levels with 2dB/per

step, it doesn’t mean that the maximum BTS output power can be decreased is Pn-30dB

unconditionally as another parameter Min Power level of BS (BsTxPwrMin) still should be

considered.

BsTxPwrMin is used to define the minimal BTS output power allowed, supposing it is set

as 10 (range is from 0-15 and 2dB/per step), then the minimal BTS output allowed is

Pn-20dB even with 15 levels dynamic power control level.

4 Parameters and Configurations

4.1 Parameter List

Table 4-1 Parameter List

Full name Downlink Rapid power control indication

Abbreviation DIRapidPcInd

Description

This parameter determines the availability of the rapid power control

process. Rapid power control process is an optional process of BSC. It

reduces the interference of the whole BSS radio system and satisfies

the dynamic power control requirement for rapid moving MS.

The amplitude of power control used by rapid power control process

each time is no longer a fixed value, but an integer multiple of cell

parameter power control step (increase and decrease). This parameter

determines the availability of the rapid power control process.

Value Range Yes/No





Unit None

Default No

Management

Object

Cell

Full name Power control

Abbreviation PwrDecrLimit

Description

This parameter is set for preventing MS from call drop due to fast power

control. It corresponds to different quality level. For example,

PwrDecrLimit [0] determines the maximum power decrease limit for calls

with receiving quality level 0 (Bit Error rate (BER) <0.2%). This

parameter is valid for both uplink and downlink.

This parameter is an array of eight elements, with element length of one

byte. PwrDecrLimit [n] determines the maximum power decrease limit

available for calls with quality level n. The value range of each element

is 0 ~ 38 dB.

Value Range 0 ~ 38

Unit None

Default [24, 22, 20, 18, 16, 14, 12, 10]

Managemen

t

Object

Cell

Full name Report period of measurement for power control

Abbreviation PwrCtrlReportPrd

Description

Power control is performed at BTS side and BSC implements relevant

performance statistics. BTS uses this parameter to decide the periodicity

to send the preprocessed power measurement to BSC as an input for

power control analysis. This parameter is in the unit of SACCH

multi-frame.

Value Range 1 ~ 254

Unit SACCH multiframe

Default 240

Managemen

t

Object

Cell





Full name Downlink level Sample count

Abbreviation PcDlLevWindow

Description

In GSM system, BSC determines whether to perform power controlaccording to measurement data. BSC uses the average value of

measurement data to avoid adverse influences caused by abrupt

changes in measurement data due to complex radio transmission.

BTS uses this parameter to calculate the window size for the average

value of downlink signal strength, i.e. to calculate the average value of

the number of used samples.

Value Range 1 ~ 31

Unit None

Default 6

Managemen

t

Object

Cell

Full name Downlink level Weight

Abbreviation PcDlLevWeight





Description

Description: According to GSM Specifications, discontinuous

transmission (DTX) refers to the process in which the system does not

transmit signals in the voice intermittent period during the subscriber

communication process.

In the DTX mode, the measurement data reported to BSC fall into two

types. One is the average of the measurement results of all timeslots in

a

measurement period in the non-DTX mode, and the other is the average

of the measurement results of some special timeslots in a measurement

period in the DTX mode. BSC needs to optionally select one type of

measurement data and use the data to calculate the average value.

The first type of measurement data is more accurate since it is the

average value of measurement results of all timeslots. The second type

of measurement data is less accurate since it is the average value of

measurement results of some timeslots. Thus BSC should use different

weights for the two types of data when averaging the measurement

results.

This parameter determines the weight for the first type of measurement

data when averaging downlink signal strength for power control. Weight

for the second type of measurement data is set to 1 by default.

Value Range 1 ~ 3

Unit None

Default 2

Managemen

t

Object

Cell

Full name Downlink quality Sample Count

Abbreviation PcDIQualWindow





Description

In GSM system, BSC determines whether to perform power control

according to measurement data. BSC uses the average value of

measurement data to avoid adverse influences caused by abrupt

changes in measurement data due to complex radio transmission.

BTS uses this parameter to calculate the window size for the average

value of downlink signal quality, i.e. to calculate the average value of the

number of used samples.

Value Range 1 ~ 31

Unit None

Default 6

Managemen

t

Object

Cell

Full name Downlink quality Weight

Abbreviation PcDlQualWeight





Description

Description: According to GSM Specifications, discontinuous

transmission (DTX) refers to the process in which the system does not

transmit signals in the voice intermittent period during the subscriber

communication process.

In the DTX mode, the measurement data reported to BSC fall into two

types. One is the average of the measurement results of all timeslots in

a measurement period in the non-DTX mode and the other is the

average of the measurement results of some special timeslots in a

measurement period in the DTX mode. BSC needs to optionally select

one type of measurement data and use the data to calculate the

average value.

The first type of measurement data is more accurate since it is the

average value of measurement results of all timeslots. The second type

of easurement data is less accurate since it is the average value of

measurement results of some timeslots. Thus BSC should use different

weights for the two types of data when averaging the measurement

results.

This parameter determines the weight for the first type of measurement

data when averaging downlink signal quality for power control.

Weight for the second type of measurement data is set to 1 by default.

Value Range 1 ~ 3

Unit None

Default 2

Managemen

t

Object

Cell

Full name Fast average indication

Abbreviation FastAvg





Description

Network may not perform handover or power control if less

measurement data is available during call process. The average

calculating process for these processes is enabled only when the

measured data reaches a certain window size.

Common average process does not take place, for the five measured

values BSC receives. BSC directly calculates the average of the 5

measured values if the fast average process is adopted.

There are three cases resulting in insufficient data for calculating the

average value, that is, call establishment period, after handover and

after power control. After performing power control once, former

measured values are discarded in

situations where they could result in an error control (measured values

without the influence on handover control are still existing).

In addition, old measured values are discarded after the handover has

occurred keeping it from causing error control (the forward and

backward cells are in the same BSC).

Value Range Yes/No

Unit None

Default No

Managemen

t

Object

Cell

Full name Increase downlink level Threshold, Value P, and Value N

AbbreviationPcDLInclLevThsThs/PcDLInclLevThsP/PcDLIncl-

LevThsN

Description

According to GSM specifications, power control decisions depend uponreceived average value series of uplink signal strength.

The decision process is as follows: For the latest N average values of

downlink signal strength, if P of the N values fall below relevant

threshold

value, increase BTS (downlink) transmission power to improve the

downlink signal quality.





Value Range

Increase downlink level can be divided into four kinds: FR, HR, AMR FR,

and AMR HR.

Threshold: 0 ~ 63; Value P: 1 ~ 31; Value N: 1 ~ 31

Unit None

Default [26, 3, 4]

Managemen

t

Object

Cell

Full name Decrease downlink level Threshold, Value P, and Value N

Abbreviation PCDLREDLEVTHSThs/PCDLREDLEVTHSP/PCDLREDLEVTHSN

Description

According to GSM specifications, power control decisions depend uponreceived average value series of uplink signal strength.


downlink signal strength, if P of the N values fall below relevant

threshold value, increase BTS (downlink) transmission power to improve

the downlink signal strength.

Value Range

Decrease downlink level can be divided into four kinds: FR, HR, AMR

FR, and AMR HR.


Unit None

Default [34, 3, 4]

Managemen

t

Object

Cell

Full name Increase downlink quality Threshold, Value P, and Value N

AbbreviationPCDLINCLQUALTHSThs/PCDLINCLQUALTHSP/PCDLINCLQUALTHS

N

Description

According to GSM specifications, power control decisions depend upon

received average value series of uplink signal strength.


downlink signal quality, if P of the N values rise above relevant threshold

value, increase BTS (downlink) transmission power to improve the






Value Range

Increase downlink quality can be divided into four kinds: FR, HR, AMR

FR, and AMR HR.


Unit None

Default [2, 3, 4]

Managemen

t

Object

Cell

Full name Decrease downlink quality Threshold, Value P, and Value N

AbbreviationPCDLREDQUALTHSThs/PCDLREDQUALTHSP/PCDLREDQUALTHS

N

Description

According to GSM specifications, power control decisions depend upon

received average value series of uplink signal strength.


downlink signal quality, if P of the N values fall below relevant threshold

value, reduce BTS (downlink) transmission power to improve the


Value Range

Decrease downlink quality can be divided into four kinds: FR, HR, AMR

FR, and AMR HR.Threshold: 0 ~ 7; Value P: 1 ~ 31; Value N: 1 ~ 31

Unit None

Default [0, 3, 4]

Managemen

t

Object

Cell

Full name Power increasing step.

Abbreviation PwrIncStep_0 ~ PwrIncStep_3

DescriptionIt describes increase step, the value of each power control variation. It

applies to both uplink and downlink directions.

Value Range

Power increase step can be divided into four kinds: FR, HR, AMR FR,

and AMR HR.

Value range is 2, 4, and 6.

Unit dB





DefaultIt can be divided into four kinds: FR, HR, AMR FR, and AMR HR. 2 by

default.

Managemen

t

Object

Cell

Full name Power decreasing step.

Abbreviation PwrRedStep_0 ~ PwrRedStep_3

DescriptionIt describes decrease step, the value of each power control variation. It

applies to both uplink and downlink directions.

Value Range

Power decrease step can be divided into four kinds: FR, HR, AMR FR,

and AMR HR.

Value range is 2 and 4.

Unit dB


default.

Managemen

t

Object

Cell

Full name Downlink power control allowed

Abbreviation PwrControlDl

DescriptionThis parameter determines whether to enable or disable BTS downlink

power control in the cell.

Value Range Yes/No

Unit None

Default No (Set YES to activate this feature)

Managemen

t

Object

Cell

Full name Min Power level of BS

Abbreviation BsTxPwrMin_0 ~ BsTxPwrMin_3

Description

This parameter controls the transmission power during communication

between MS and BTS. SACCH carries the command with 2 header

bytes information (power control byte and timing advance byte) from

BSC to BTS. When BSC performs power control, this parameter

determines the BTS’s minimum transmission power in the cell.





Value Range

MIN power level of BS can be divided into four kinds: FR, HR, AMR FR,

and AMR HR.

Value range is 0 ~ 15.

The maximum power level of BTS is Pn.

0: Pn;

1: Pn-2 dB;

……

15: Pn-30 dB

Unit None


default.

Managemen

t

Object

Cell

Full name MIN interval of power control

Abbreviation PcMinInterval_0 ~ PcMinInterval_3

Description

This parameter specifies the minimum interval of power control. Usually,

MS still sends two measurement reports with the original power to BSC

after enabling the power control. Signal level information contained in

the reports is inaccurate and can be ignored (information such asadjacent cell information is still valid). Thus a minimum interval of power

control is needed and signal level information during the interval can be

ignored.

Value Range

MIN interval of power control can be divided into four kinds: FR, HR,

AMR FR, and AMR HR.

Value range is 1 ~ 32.

Unit SACCH multiframe

Default

It can be divided into four kinds: FR, HR, AMR FR, and AMR HR. 2 by

default.

Managemen

t

Object

Cell

4.2 Parameter Configurations

Enter the configuration management section.





1. In the navigation tree, click the drop-down menu of the cell to be configured, and

double-click Power control, as shown in Figure 4-1.

Figure 4-1 Power Control1

2. Set Downlink rapid power control indication and Power control levels max

descending value in Power control tab of Power control menu to choose whetherperform Rapid power control and adopt restricting conditions of rapid power control, as

shown in Figure 4-2:





Figure 4-2 Power Control1 zoom in

Set following parameters in Power survey tab in Power control menu to choose powercontrol decision algorithm related parameters:

Report period of measurement for power control

Downlink level sample count

Downlink level sample weight

Downlink quality sample count

Downlink quality sample weight

Survey section is shown in Figure 4-3:





Figure 4-3 Power Survey

Set following parameters in Power adjust threshold tab in Power control menu to

choose power control decision criteria threshold.

Increase downlink level of FR (Ths, P and N)

Increase downlink level of FR (Ths, P and N)

Increase downlink level of AMR FR (Ths, P and N)

Increase downlink level of AMR HR (Ths, P and N)

Decrease downlink level of FR (Ths, P and N)

Decrease downlink level of FR (Ths, P and N)

Decrease downlink level of AMR FR (Ths, P and N)

Decrease downlink level of AMR HR (Ths, P and N)

Increase downlink quality of FR (Ths, P and N)

Increase downlink quality of FR (Ths, P and N)

Increase downlink quality of AMR FR (Ths, P and N)





Increase downlink quality of AMR HR (Ths, P and N)

Decrease downlink quality of FR (Ths, P and N)

Decrease downlink quality of FR (Ths, P and N)

Decrease downlink quality of AMR FR (Ths, P and N)

Decrease downlink quality of AMR HR (Ths, P and N)

Power adjust threshold is shown in Figure 4-4:

Figure 4-4 Power adjust threshold

Downlink received signals strength can be divided into 64 grades, ranging from 0 to 63,

which are corresponding to different levels respectively. 0 refers to the lowest received

signal level, 63 means the highest. Corresponding level values is shown in Table 4-2.

Table 4-2 Level Values Corresponding to Downlink Signal Strength Threshold

Threshold Level Value (dBm)

0 < -110

1 -110 ~ -109





2 -109 ~ -108

… …

61 -50 ~ -49

62 -49 ~ -48

63 > -48

Downlink received signals quality can be divided into 8 grades, ranging from 0 to 7, which

are corresponding to different Bit Error Ratio (BER) respectively. 0 refers to the lowest

received signal BER, 7 means the highest. Corresponding BER values is shown in Table

4-3.

Table 4-3 BER Corresponding to Downlink Signal Quality Threshold

Quality BER

0 BER<0.2%

1 0.2%<BER<0.4%

2 0.4%<BER<0.8%

… …

6 6.4%<BER<12.8%

7 12.8%<BER

In Others tab of Power control menu, set following parameters to choose whether to

power control and adopt restricted conditions of this feature.

● FR power increasing step

● HR power increasing step

● AMR FR power increasing step

● AMR HR power increasing step

● FR power decreasing step

● HR power decreasing step

● AMR FR power decreasing step

● AMR HR power decreasing step

● Downlink power control





● FR BS MIN power level

● HR BS MIN power level

● AMR FR MIN power level of BS

● AMR FR MIN power level of BS

● FR MIN interval of power control

● HR MIN interval of power control

● AMR FR MIN interval of power control

● AMR HR MIN interval of power control

Others is shown in Figure 4-6:

Figure 4-2 Others





5 Related Counters and Alarms

5.1 Related Counters

Table 5-1 Related counters

Counter ID What It Counts

C901320005 Number of normal increases of BS power due to DL signal level

C901320006 Number of rapid increase in BTS power due to DL signal level

C901320007 Number of normal decrease of BS power due to DL signal level

C901320008 Number of rapid decrease in power BTS due to DL signal level

C901320013Number of normal increases of BS power due to DL signal

quality.

C901320014 Number of rapid increase in BTS power due to DL signal quality

C901320015 Number of normal decrease of BS power due to DL signal quality

C901320016 Number of rapid decrease in BTS power due to DL signal quality

C901320019

Total value of each result of regular scanning of BS utilization

power

C901320020 Number of regular scanning and sampling of BS utilization power

C901320021 Total value of power scans of DL signal level

C901320022 Number of power scans of DL signal level

C901320025 Total value of power scans of DL signal quality

C901320026 Number of power scans of DL signal quality

C901320031 Maximum value obtained in regular scan of DL signal level

C901320032 Minimum value obtained in regular scan of DL signal level

C901320033 Sum of Periodic BS Power (TCH/F) Search Result

C901320034 Periodic BS Power (TCH/F) Search Times

C901320035 Sum of Periodic BS Power (TCH/H) Search Result

C901320036 Number of Periodic BS Power (TCH/H) Search

C901320037 Sum of Periodic BS Power (SDCCH) Search Result

C901320038 Number of Periodic BS Power (SDCCH) Search

C901320039 Sum of Periodic DL Signal Level (TCH/F) Search Result





C901320040 Number of Periodic DL Signal Level (TCH/F) Search

C901320041 Sum of Periodic DL Signal Level (TCH/H) Search Result

C901320042 Number of Periodic DL Signal Level (TCH/H) Search

C901320043 Sum of Periodic DL Signal Level (SDCCH) Search Result

C901320044 Number of Periodic DL Signal Level (SDCCH) Search

5.2 Related Alarms

None

6 Engineering Guide

6.1 Application Scenarios

This feature suits for all scenarios.

6.2 Configuration Description

This feature does not involve iBSC and BTS hardware configuration adjustment.

6.3 Network Impact

Influence on network:

Activation of dynamic BTS power control can reduce BTS transmission power with stable

downlink signal strength, aiming at decreasing intra-network co-channel and

adjacent-frequency interference, lowering BTS power consumption.

Using dynamic BTS power control with reasonable parameter setting can provide the

following benefits:




Decrease intra-network co-channel and adjacent-frequency interference, improve

network KPI, reduce TCH call drop, enhance handover success rate;

Lower BTS power consumption;

Influence on network element:

This feature does not affect capacity of iBSC and BTS.

7 AbbreviationAbbreviations Full Characteristics

3GPP 3rd Generation Partnership Project

BSC Base Station Controller

BTS Base Transceiver Station

MR Measure Report

SACCH Slow Associated Control Channel

8 Reference Document

[None]

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