BTS Power Control.doc

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USER DESCRIPTION 78/1553-HSC 103 12/4 Uen B

User Description, Dynamic BTS Power Control

Copyri!"

Ericsson AB 2002. All rights reserved.

Di#$%&i'er

The contents of this document are subject to revision without notice due to continuedprogress in methodology design and manufacturing.

Ericsson shall have no liability for any error or damages of any !ind resulting fromthe use of this document.

Contents

1 In"ro()$"ion

2 *%o##&ry

2." #oncepts2.2 Abbreviations and Acronyms

3 C&p&+i%i"ie#

$." %nterference$.2 Battery bac!up power consumption

$.$ &eceiver saturation$.' (uality and signal strength impact

4 Te$!ni$&% (e#$rip"ion

'." )eneral'.2 Algorithm

'.$ *andover power boost'.' +ower regulation e,ample

'.- )+&/E)+&'. A1& & +ower #ontrol

'.3 1ain changes in Ericsson )1 system &"0/B &"0

5 Enineerin )i(e%ine#-." %nteractions with other features

-.2 re4uency planning aspects-.$ &ecommendations

, P&r&'e"er#." 1ain controlling parameters

.2 +arameters for special adjustments

.$ 5alue ranges and default values


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7 Reeren$e#

8 .ppen(i .

1 Introduction

6ith the 7ynamic BT +ower #ontrol feature the output power of a Base Transceivertation 8BT9 can be controlled during a connection. The control strategy is to

maintain a desired received signal strength and 4uality in the mobile station 819.

This :ser 7escription describes the BT +ower #ontrol and A1& +ower #ontrol

algorithm for circuit switched connections only.

2 Glossary

2.1Concepts

e)re'en"

Repor" 1essage consisting of measurements done by the 1 which issent from the 1 to the BT.

e)re'en"

Re#)%" 1essage consisting of the 1easurement &eport and

measurements done by the BT which is sent from the BT to

the B#.

2.2Abbreviations and Acronyms

.R Adaptive 1ulti &ate

BCCH Broadcast #ontrol #hannel

C/I #arrier to %nterference &atio

CN. #ellular ;etwor! Administration

DT 7iscontinuous Transmission

*PRS )eneral +ac!et &adio ervice

RP


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SDCCHtand Alone 7edicated #ontrol #hannel

3 Capabilities

3.1Interference

The aim with BT +ower #ontrol is to increase the number of 1s with sufficiently

good #/%. BT +ower #ontrol will improve #/% if traffic is maintained or maintain #/%when traffic is increased or tighter fre4uency re=use is realised. The gain is obtained

by a reduction of the over all interference level 8%9 in the networ!.

6hen BT +ower #ontrol is used in all BTs in the networ! the total amount of

radiated power is reduced compared to when it is not used. This implies that the

downlin! co= and adjacent channel interference in the networ! is reduced. ince 1swith low signal strength or bad 4uality use full BT output power reducedinterference level imply increased #/% for these connections. >n the other hand the

#/% is decreased for connections with high signal strength and good 4uality sincethey are subjected to a reduced BT output power. &eduction of #/% will not affect

the speech 4uality of these connections since they have a margin to the lowesttolerable #/%.

re4uency *opping together with BT +ower #ontrol and 7T? improve the

possibilities to achieve very tight fre4uency reuse see further :ser 7escription7iscontinuous Transmissionand :ser 7escription re4uency *opping.

3.2Battery backup power consumption

%f the power supply for the base station is cut off a battery bac!up is used. 6henBT +ower #ontrol is used the battery consumption is reduced and the ma,imum

possible speech time will increase.

3.3Receiver saturation

The high signal energy from BTs transmitted to 1s that are close might saturatethe 1 receiver. The sensitivity of the receiver will then decrease and the speech

4uality become poor. %f the output power of the concerned BTs is lowered the ris!

for this !ind of radio fre4uency bloc!ing is reduced. The receiver might still bebloc!ed if an 1 is very close to the base station but the probability for this is

significantly reduced.

3.4Quality and signal strength impact
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Both 4uality and signal strength is considered by the algorithm. (uality is theestimated bit error rate which is represented by rxqual. ignal strength is

represented by rxlev. Bad 4uality as well as low signal strength will increase theoutput power of the BT.

4 Technical description

4.1General

%mportant notice@ The algorithms in 1 +ower #ontrol and BT +ower #ontrol are the

same.

%n igure " the BT output power and the signal strength in the 1 versus path lossbetween a BT and an 1 is shown. A BT can only transmit at distinct power levels

this is illustrated in the figure.

Figure 1 Base station output power and MS signal strength versus path loss.

Quality is not taken into account.

6hen a connection has low path loss 8left part of igure "9 the BT transmits at its

lowest possible power level. Although the 1 receives a signal that e,ceeds thedesired value the BT can not reduce the transmitted power any further. #onversely

when a connection e,periences high path loss 8right part of igure "9 the BTtransmits at the ma,imum allowed power level for the cell. The power cannot be

increased even if the received signal strength in the 1 is low. ;ote that this isdependent on the path loss compensation used 8see ection '.2.'9.

6hen 4uality is ta!en into account the output power is regulated up or down

depending on the received 4uality 8see igure 29. The base station power thenvaries with the 4uality measured by the 1. 6hen an 1 has low rxqual8high
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4uality9 the base station sends on low power and when an 1 has high rxqual onhigh power. The higher the rxqual the higher the power and vice versa.

Figure 2 Exaple o! B"S output power versus rxqual. Signal strength is not takeninto account.

4.2Algorithm

421 *ener&%

7ynamic BT +ower #ontrol is performed for Traffic channels 8T#*s9 as well as for

7##*s. +ower control of the 7##*s is enabled with the switch SDCCHRE*. Alltime slots on the B##* fre4uency are transmitted on full power i.e. there is no

+ower #ontrol of these time slots.

7uring a call the 1 measures the downlin! signal strength and 4uality. These

measurements are sent to the BT in the 1easurement &eport and further on to theB# in the 1easurement &esult message where they are used for calculation of a

new BT output power.

The measurements from the 1easurement &esult that are used in the 7ynamic BT

+ower #ontrol algorithm are shown in Table ".

Table 1 Measurements used by BTS Power Control

D&"& (e#$rip"ion So)r$e

signal strength downlin! full set 8"9 1

signal strength downlin! subset 8"9 1

4uality downlin! full set 8"9 1
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4uality downlin! subset 8"9 1

power level used by BT BT

7T? used by BT or not BT

8"9The 1 performs signal strength and signal 4uality measurements on the

downlin!. 1easurements are made on the full set of frames 8full set9 as well as onthe subset of frames where there is always traffic 8subset9. 6hich of the sets will be

used depends on whether 7T? downlin! has been used or not during themeasurement period 8see also :ser 7escription 7iscontinuous Transmission9.

The minimum time period between two consecutive power orders is controlled by theparameter RE*INTD. RE*INTDis set in units of A##* periods 8'0 ms9

between " and "0.

The BT is able to change its output power on a time slot basis. The resolution in

output power is in steps of 2 dB and the ma,imum configurative change is $0 dB.

or a single connection the ma,imum change per A##* period is also $0 dB.

7own regulation can be limited to 2 dB per A##* period by means of the parameterSTEPID. The default value of this parameter is >.

The 7ynamic BT +ower #ontrol algorithm consists of three stages@

". Preparation of input data

The output power level used in the latest measurement period is convertedfrom a relative scale. A decision is ta!en about which set of measurements

8full set or subset 8"99 to use. ignal strength and 4uality are compensated for

fre4uency hopping and power control.

2. Filtering of measurements

1easurements are filtered in e,ponential non=linear filters in order to

eliminate variations of temporary nature.

$. Calculation of power order

Two power orders are calculated according to the algorithm using twodifferent parameter settings. The one with the ma,imum power order

8minimum attenuation9 is chosen. A number of constraints 8according to

hardware limitations and parameter settings9 are applied to the chosen powerorder.

422 Prep&r&"ion o inp)" (&"&
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The output power level used by the BT 8T&:9 at A##* period k is given by #$used8see e4. "-9 as a number of 2 dB steps downwards from the configured output

power.

B"S %"&'( output power %k( %dB( BSPRT= 2 C #$used 8"9

%n the 1easurement &esult message the BT sends information about whether 7T?8see :ser 7escription 7iscontinuous Transmission9 has been used during the

measurement period or not. This information is used by the B# to decide which setof downlin! measurements full set or subset to use on T#*s. The subset of

measurements should be used if 7T? was used during the measurement period bythe BT. >n 7##*s the full set of measurements are always used.

To be able to use the desired 4uality 8DESD9 and the measured rxqualin thecalculations both must be converted to )*+e,pressed in dB according to Table 2.

The mapping between rxqualand )*+is non=linear due to that faster regulation is

needed for low and high rxqualvalues.

Table 2 Table with relations due to non-linear r!ual to C"# mapping

DESDDdt4u 0 "0 20 $0 '0 -0 0 30

rxqual 0 " 2 $ ' - 3

)*+DdB 2$ "F "3 "- "$ "" '

DESDdefines a desired value for rxqualthat the regulation will aim for in the

regulation process and is given in dt4u 8deci=transformed 4uality units9. 7ifferencebetween dt4u and rxqualis a factor of ten. %f DESDis not e4ual to the valuesgiven in Table 2 linear interpolation is used to realiGe )*+.

E,ample of DESDinterpolation@

%f DESD $- then )*+ "-H8"$="-9C0- "' dB

DESDe,pressed in #/% is called Q,ES,$-dBwhich is the value used in thecalculations.

The B##* fre4uency is not subjected to power control. 6hen fre4uency hopping

8:ser 7escription re4uency *opping9 is applied and the B##* fre4uency isincluded in the hopping set the BT output power will vary from burst to burstdepending on which fre4uency the burst is sent on. A compensation is necessary to

obtain a correct estimation of the measured signal strength see e4. 2.

SS") SSM= 8BSPR-BSTPRH2C#$used9 / /! 829
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where SS")is the signal strength on the down regulated T#* carriers SSMthemeasured signal strength reported by the 1 BSPR is the BT output power on

the B##* fre4uency in the


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then $ SSEND

else $ SSENDC UPDNR.TIO* 177 8-9

where $is rounded upwards to A##* periods. 6hen the length e,ceeds $0 A##*periods the length is set to $0.

To enable calculating and sending the power order immediately after assignment orhandover the filter is initiated with SSF+$"E&E, %k51( SSDESD. This leads to that the

regulation starts immediately after the first valid 1easurement report.

(uality filtering is performed in the same way as for signal strength i.e. withe,ponential non=linear filters. The filtering is done according to e4. .

QF+$"E&E,%k( 3 Q-)0M#%k( 4 a 3 QF+$"E&E,%k51( 89

where QF+$"E&E,is the filtered 4uality compensated for down regulation i.e. theestimated #/% 8in dB9 that would have been received by the 1 if no power control

was used. Q-)0M#is the compensated 4uality part according to e4. 3.

Q-)0M# &8Q'9$-dB H 2C#$used 839

where &8Q'9$-dBis the measured rxqualtransformed to )*+8in dB9 according toection '.2.2.

The coefficient ain e4. above is given by the length of the e,ponential filter 8see

Appendi, A9 in the same way as for the signal strength case only that this time $isdetermined in the following way@

if Q-)0M#%k( 6 (%


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". The two basic power orders are calculated.2. #ertain constraints are applied.

$. The output data is finally converted to power order units before it istransmitted to the BT as a power order.

The actual information sent to the BT is the power level #$used according to ection

'.2..

The basic power orders for regulation 8pu1andpu29 are given by the followinge,pression@

pui i3 8SSDESD5 SSF+$"E&E,9 H iC 8(7E7


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The lowest allowed power order is given by the ma,imum of

a. =$0

b. BSPRT = 81iminum BT output power 8*6 limit99

c. BSTPR - BSPRIN

;ote that even if the actual output power BSPRTin the BT is set to the minimum

value lower power levels can actually be achieved when BT +ower #ontrol is active.or an &B2000 )1F00 1*G with minimum output power possible to configure

e4ual to $- dBm 8BSPRT@ $- to '3 dBm odd values only9 the lowest achievable

output power is '3 = $0 "3 dBm when BT power control is active.

42, Coner#ion o o)"p)" (&"&

The new power order has to be converted from the internal dBm scale to #$used

representation before it can be transmitted to the BT. %n reality this means that theconstrained power order is 4uantisiGed in steps of 2 dB according to@

#$used %nt8=pu/2 9 D0.."-

where #$usedis the power level. #$used 0 represents full power and #$used "-

represents $0 dB down regulation.

The power is always truncated to a higher value 8lower down regulation9.

427 Re)%&"ion pro$e()re

6hen a T#* connection is set up ma,imum configurative output power is alwaysused for e,ample in the following situations@

assignment of a T#*.

assignment failure or handover failure.

intra=cell handover and subcell change.

inter=cell handover.

7own regulation always starts after the first valid 1easurement report 8see ection'.2.$9. The response time for up regulation is controlled by the parameters END

and SSEND. ENDdetermines the response time on high interference and

SSENDon signal strength drops. The values of ENDand SSENDcorresponds to a F0 J rise time of the e,ponential filters.

The response time for down regulation is determined by the e,pressions END

CUPDNR.TIO/"00 and SSENDCUPDNR.TIO/"00 where UPDNR.TIOis the ratio between up= and down regulation speed. This results in a 4uic! up

regulation and a smooth down regulation.

UPDNR.TIOis a B# e,change property.


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to ma,imise the probability of a successful handover *andover +ower Boost shouldbe used.

ince the ma,imum configurative power is only used for a short time before the

handover activating *>+B has a minor impact on the overall interference level in thenetwor!.

;ote that *>+B only improves the *> performance if power control is activated.

*andover power boost is activated by setting the state variable *+BTATE.

4.4Power regulation example

The most important thing for good comprehension of the BT +ower #ontrolalgorithm is to understand how the two algorithms wor! in parallel and how different

settings of the available parameters will influence the regulation. The e4uations givenin ection '.2.'can be used to find out how much the output power will be down

regulated for a certain signal strength and 4uality. But to get an overview picture ofthe algorithm as a whole the dependence between signal strength 4uality and down

regulation must be understood.

A suitable way of studying these three 4uantities is in a three dimensional plot

describing the static behaviour of the algorithm.


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As it can be seen in igure $ the surface is raised for rxlevK "' and rxqualL -. Thedown lin! for 1s in this area is down regulated. The level of the down regulation is

shown on the G=a,is.

;ote that rxqualand rxlevin igure $corresponds to the measured values collectedfrom the 1easurement &eport before any compensation has been done.

The static behaviour is calculated by assuming an initial down regulation of Gero and

that the path loss to the 1 is constant. Then for a certain value of initial &,


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The A1& & speech coding is more robust and can perform well on low #/% levels.This results in a possibility to down regulate the output power of A1& & connections

more than for non=A1& connections. This means that A1& & +ower controlparameter set can be set more aggressive than for non=A1& parameter setting. To

be able to set the parameter more aggressive for A1& & connections two newparameters are implemented SSDESD.6R and DESD.6Rin the 7ynamic BT

+ower #ontrol. This means that the two power orders for A1& & connections arecalculated according to@

pui iC 8SSDESD.6R= SSF+$"E&E,9 H iC 8(7E7


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the A1& & +ower #ontrol parameters SSDESD.6R and DESD.6Rthat

set the limits for how close to the noise floor 8how low rxlev9 and how high in

interference 8how high rxlev9 A1& & down regulation can be performed. the 4uality compensation factor COPD and the path loss compensation

factor COPD that determine the angles of inclination of plane $ in igure$.

the intra=cell handover area defined by O66SETDand O66SETD.6R8:ser 7escription %ntra #ell *andover9.

the threshold triggering bad 4uality urgency handovers IDand

ID.6R8:ser 7escription


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*owever since downlin! power regulation is never performed on B##* carriers theimpact of downlin! regulation will be greater in systems having three or more

Transceivers 8T&?s9 per cell.

6hen introducing BT +ower #ontrol into a system it is recommended to begin withmoderate settings for the controlling parameters. The majority of the gain obtained

from using power control originates from the first decibels of regulation. Therefore agood strategy is to down regulate many connections with a few dB. To get the besteffect it is important to reduce the BT output power for as many connections as

possible also those connections to 1s in the cell border regions being closest toneighbouring users. or such 1s however the interference levels are often

considerable and great care has to be ta!en not to degrade such calls.

532 T)nin o "!e &%ori"!'

The shown down regulation in igure $and in the graphs in this section is a target

regulation that the algorithm aims for. %t is important to understand that the downregulation is determined by the $o'+in&"ionof the parameters SSDESDand

DESDor SSDESU.6Rand DESU.6Rfor A1& & connections not one of theparameters alone. ince the environment changes 4uic!ly and the filtering of signal

strength and 4uality introduces delays the target down regulation is never reacheddirectly.

The recommended strategy 8see igure $9 is a good parameter setting that is notparticularly aggressive according to any regulation strategy. By changing the

parameters the regulation can be made more aggressive towards 4uality or signal

strength or combinations depending on the needs of the customer.

;ote it is not recommended to limit the down regulation with the parameterBSPRIN. %f used the parameter will seriously limit the regulation towards

interference and also introduce a delay in the regulation algorithm. %nstead it isrecommended to use a more restrictive parameter setting e.g. according to igure .

To get a regulation that is more aggressive towards 4uality 8i.e. allows higherinterference before it regulates up to full power9 DESDcan be set to a higher

value e.g. DESD '0. This will lead to if no other parameters are changed anincrease of the raised surface in igure $that grows mainly to the right 8towards

worse 4uality9 but also a little bit to the left 8towards lower signal strength9. And ifthe inclination of plane $ is left unchanged the result is also an upwards shift of this

plane. As an e,ample igure 'shows more aggressiveness towards 4uality signalstrength and down regulation compared to igure $. till the only parameter that

has been changed is DESD.


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Figure < 9ggressive paraeter setting towards quality. "his setting is rather

aggressive: also towards signal strength and down regulation. 0nly paraeterQ,ES,$ has een changed copared to recoended setting %see Figure ;(.

or the parameter setting in igure ' the 4uality part of the power control willalways fully compensate for bad 4uality. ull power should be reached 4uic!ly in case

of high rxqual8rxqual - or 39. This is in order to minimise the ris! of havingpoor speech 4uality due to too much down regulation and also prevent unnecessary

intra=cell handovers and urgency handovers. *ence a shorter 4uality filter might beneeded 8see ection -.$.'9.

As an e,ample of more aggressive regulation towards signal strength study igure

-. The only parameter changed compared to the recommended setting is SSDESDwhich is set to =F3. or this setting the downlin! for 1s with rxlev "0 and rxqual 0 is down regulated ' dB. ;ote that this might sound a bit more aggressive than it

is since at this low signal strength noise will impose occasional bit errors to theconnection. This will ma!e the regulation to MbounceM on the noise floor. 5ery few

connections will then manage to be as much as ' dB down regulated. %nstead mostconnections will alter between 0 and 2 dB down regulation.
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Figure = 9ggressive regulation towards low rxlev. MSs with low signal strength also

get down regulated in case o! good quality.

As an e,ample of a more careful regulation strategy see igure . This shows how

DESDcan be decreased compared to the recommended setting to get a verymoderate setting. 1a,imum "0 dB down regulation is then allowed.

Figure > Moderate paraeter setting. 0nly paraeter Q,ES,$ has een changedcopared to recoended setting %see !igure ;(

To compensate for this low setting of DESD one alternative could be to allowmore down regulation for those 1s that have good 4uality. igure 3show how this

can be done. The parameter COPDis increased and as a result the inclination of
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plane $ is changed. The algorithm then allows more down regulation for 1s withgood 4uality but is still careful when it comes to regulation towards bad 4uality.

Figure ? Moderate paraeter setting: ore aggressive towards down regulation.

Another way of changing the inclination of plane $ would be to change the path loss

compensation parameter COPD. %n igure COPDhas been set to "0while all other parameters are the same as in igure . This results in that the 1s

with high signal strength regardless of 4uality gets more down regulated.

Figure @ Moderate paraeter setting with path loss copensation !actor $)0M#,$set to 17. "his results in a very aggressive ehaviour towards down regulation.
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6ith the setting in igure plane $ has become very large and dominating. Thissetting has regulation towards signal strength and is more aggressive towards down

regulation. The ma,imum down regulation is here " dB compared to "' dB for theold recommended setting.

%mportant notice@ The default values given in Table $are also ;>T recommended to

useN

533 E&'p%e# o p&r&'e"er #e""in#

Below are some e,amples of static behaviour with different parameter settingsshown. The first figure illustrates the recommended setting and the rest of the

e,amples are sorted in order of increasing MaggressivenessM. These e,amples can allbe considered as recommendations for different MaggressivenessM levels.

Figure A "he recoended setting.
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Figure 17

Figure 11
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Figure 12

Figure 1;
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Figure 1

534 6i%"er ")nin

)enerally for up regulation the BT +ower #ontrol 4uality filter ENDcan be set

to a value between 2 or -. This is fairly uncritical since instability in the control loop

has not shown to be a problem with this control strategy. Therefore it is better tohave a short power control 4uality filter since the response to bad 4uality then

becomes 4uic!. %t is not useful to set END ". This would only lead to

e,tremely nervous behaviour resulting in less average down regulation. Tests haveshown that the difference in fast up regulation between END 2 and END

$ is insignificant.

%n order to avoid unstable behaviour the down regulation must be slow. Tests have

shown that a filter with lengths between and F is good. >f course longer filters canalso be used. This would result in an even more cautious behaviour. The filter length

on the down regulation is determined by parameters ENDand UPDNR.TIO.UPDNR.TIOsets how much longer the down regulation filter is compared to the

up regulation filter in percent. %t is recommended to use high UPDNR.TIOinstead of using STEPID. As an e,ample of how the system reacts to bad

4uality see igure "3.

E,ample@

ENDis 2 and UPDNR.TIO is 00.

This gives 2 A##* periods filter length for up regulation and 2C00J 2C "2

A##* periods filter length for down regulation.
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Figure 1? Step response to ad quality. #araeter setting Q$E/,$ ; and'#,/&9"+0 ;77 was used. /ote the logarithic ehaviour o! the down

regulation.

The BT +ower #ontrol signal strength filter is less critical. The regulation is done inthe same way as for 4uality filtering. The length of the up regulation filter is set by

the parameter SSENDand for the down regulation by SSENDand

UPDNR.TIO. or up regulation SSEND $ is recommended. The parameterUPDNR.TIOshould be tuned for the 4uality filter. %f it is tuned for 4uality

filtering it is also valid for signal strength filtering. Thus for down regulation a filterlength of to F is recommended but longer filter lengths can be used if necessary.

ee also igure ".

Figure 1@ Step response to low signal strength. #araeter setting SS$E/,$ ;and '#,/&9"+0 ;77 was used. 9ggressive paraeter setting gave 1> dB down

regulation e!ore the low signal strength occurred. /ote the logarithic ehaviour o!the down regulation.
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RE*INTDshould be set to RE*INTD " in order to ma!e the up regulation4uic! in bad 4uality situations.

6 Parameters

6.1Main controlling parameters

SSDESDdefines the target value for the desired signal strength measured by the

receiver in the 1 at the outer rim of the regulation area. The parameter is set persubcell.

DESDdefines the target value for the desired 4uality level measured by the

receiver in the 1. %t is measured in r,4ual units and transformed into dB unitsbefore is used in the algorithm. The parameter is set per subcell.

SSDESD.6Rdefines the target value for the desired signal strength for A1& &connection measured by the receiver in the 1 at the outer rim of the regulation

area. The parameter is set per subcell.

DESD.6Rdefines the target value for the desired 4uality level for A1& &

connection measured by the receiver in the 1. %t is measured in r,4ual units andtransformed into dB units before is used in the algorithm. The parameter is set per

subcell.

COPDis the parameter that determines how much of the path loss that shall be

compensated for in the algorithm that regulates towards 4uality. The parameter isset per subcell.

COPDis the parameter that determines the weight of the 4uality compensation.This parameter ranges between 0 and "00 and is set per subcell.

6.2Parameters for special adjustments

RE*INTDdefines the regulation interval. The parameter is set per subcell.

SSENDdefines the length of the signal strength filter. The parameter is set persubcell.

ENDdefines the length of the 4uality filter. The parameter is set per subcell.

SDCCHRE*is a switch for the regulation of 7##* channels. The switch is set per

subcell.

BSPRINdefines the minimum allowed output power for the BT on the non=

B##* fre4uencies. The parameter is set per subcell.


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BSTPRdefines the ma,imum allowed power level for BTs in the current subcell.The parameter is also used in >; >; >

BSPRIN =20 =20 =20 to H-0 dBm

BSTPR829

0 to 0 dBm
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3 0.3"F3

0.3'FF

F 0.33'$

"0 0.3F'$

"" 0."""

"2 0.2-'

"$ 0.$33

"' 0.'$

"- 0.-33

" 0.0

"3 0.3$$

" 0.3FF

"F 0.-F

20 0.F"$

2" 0.F2

22 0.F00

2$ 0.F0'3

2' 0.F0-

2- 0.F"20

2 0.F"-2

23 0.F"$


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2 0.F2""

2F 0.F2$3

$0 0.F2"

BTS Power Control.doc

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