NR測量方法說明 2.1

TechnicalReport5G–18.02.2020

?METAS

Page

PAGE

10

of

NUMPAGES

25

FederalInstituteofMetrologyMETAS

TechnicalReport:MeasurementMethodfor5GNRBaseStationsupto6GHz

18February2020

(Version2.1from20April2020)

Publisher FederalInstituteofMetrologyMETASLindenweg50

3003Bern-Wabern

Tel.+41583870111

www.metas.c

h

Copyright Thisdocumentmaynotbepublishedorforwardedotherthaninfull.

Report METAS-report154.1-2020-5218-1016

ThisreportisavailableinPDFformatatthefollowinglink:

http://www.metas.ch/nisv

( TechnischeBerichte/Rapportstechniques/Rapportitecnici)

Bern-Wabern,18February2020

Version2.1:20April2020;changesfromversion2.0aremadevisible(trackchangemode)

Tableofcontent

Introduction 4

TheOrdinancerelatingtoProtectionfromNon-IonisingRadiation 4

Measurementrecommendations 4

Motivationandscopeofthisdocument 4

Outline 4

Scope 5

Applicationandoutlook 5

Code-selectivemeasurementmethod 6

Measurand 6

Appreciationvalue 7

Comment 8

ExtrapolationfactorfortheSSS 9

AntennaCorrectionFactor 10

Definition 10

Comment 11

Simplifications 12

Beamstatisticfactor 13

Duplexfactor 14

Summingallcellsandtechnologies 14

Complianceassessment 14

Frequencyselectivemethod 15

Measurand 15

Appreciationvalue 15

Complianceassessment 16

Literature 17

AnnexA:BasicsinNR(informative) 18

SS/PBCHBlockstructureaccordingto[9] 18

TimingoftheSS/PBCHblocksaccordingto[10] 19

AnnexB:Examples 20

Code-selectivemeasurement 21

Frequency-selectivemeasurement 22

AnnexC:Definitions,symbolsandabbreviations 23

Introduction

TheOrdinancerelatingtoProtectionfromNon-IonisingRadiation

The“OrdinancerelatingtoProtectionfromNon-IonisingRadiation”(ONIR)[1]publishedin1999(initsversionofthe1stofJune2019),defines

Exposurelimitvaluesforelectromagneticfieldsforfrequenciesrangingfrom0Hzto300GHz(basedonICNIRP[2]).

Thesocalled“installationlimitvalues”thataremorestringentthantheexposurelimitvalues.Theselimitvalueshavebeenintroducedasprecautionarylimitationofemissions.Theyapplytotheradiationemittedbyoneinstallationinitsreference-op-eratingmode,whichcorresponds(incaseofmobiletelecommunicationsystems)totheoperationatmaximum“speechanddata”trafficandatmaximumtransmissionpower.Theyhavetoberespectedatplacesofsensitiveuse,e.g.apartments,offices,schools,children’splaygroundsetc.

Inotherwords,complianceassessmentofamobilephonebasestationincludesameasure-mentoftheelectricfieldstrengthatadefinedtimeaswellasanextrapolationofthemeas-uredvaluestothereference-operatingmode.

Measurementrecommendations

Asaconsequenceofthedefinitionsdescribedabove,toassesstheconformityofaninstalla-tionwiththelegalrequirements,ameasurementoftheelectricfieldstrengthandadditionalcalculationsareneeded.Thesetwostepsmakeitpossibletodeterminethefieldstrengthsthatareexpectedinthereference-operatingmode.Inordertoharmonizethewaythesemeasurementsandextrapolationsareperformed,aseriesoftechnologyspecific“measure-mentrecommendations”ortechnicalreportshavealreadybeenpublished:GSM[3],EDGE[4],UMTS[5],Broadcasting[6],andLTE[7].

Motivationandscopeofthisdocument

WiththeintroductionofNewRadio(NR)asatechnologyinthe5Gmobiletelecommunica-tionnetworks,itisnecessarytodevelopareferencemethodformeasuringfieldlevelsofNRinstallationsinindoorandoutdoorenvironments.Themethodshouldbe:

robustandpracticable,

providingextrapolationsthatareaccurate,avoidingover-orunderestimationoftheelectricfieldstrengthinthereferenceoperatingmode,

takingintoaccountthebeamsteeringfeaturesofthe5Gtechnology,

takingintoaccountthevariabilityofthetransmissiondirectionandantennapatternfromadaptiveantennasaccordingtoannex1,paragraph63oftheONIR[1],asof1stofJune2019,

inlinewiththepreviousmeasurementrecommendations,

applicabletoFDDaswellastoTDDduplexingmodes.

Outline

Asinthecaseofthepreviousmeasurementrecommendations,twodifferentmethodsareproposedhere:

Thecode-selectivemethodallowsthecomplianceassessmentofaninstallationwiththeinstallationlimitvalueandisconsideredasthereferencemethod.

Thespectralmethod(frequencyselectivemethod)doesnotallowthedistinctionoftwodifferentcellsofthesameoperator/installation.Moreover,itsuffersfromoveresti-mationoftheextrapolatedfieldstrengthofthereference-operatingmode.Whileitis

abletodemonstratecomplianceofaninstallationwiththeregulation,itfailstomakeafinalassessmentonthenon-compliance(eveniftheextrapolatedfieldstrengthex-ceedstheinstallationlimitvalue).Thismethodisthereforeconsideredasanapproxi-matemethod(“OrientierendeMessung”).

Scope

Accordingtorelease15ofthe5G-release15standard[8],theNRtechnologycoverstwofre-quencyranges:thefirstfrequencyrangefrom450MHzto6GHz,andthesecondfrequencyrangefrom24.5GHzto52.6GHz.Thepresentreportisrestrictedtothefirstfrequencyrangeupto6GHz.

Applicationandoutlook

Thisdocumentincludesastatisticalextrapolation(reduction)foradaptiveantennasthathasforthemomentaconservativedefaultvalueof1.TheprecisevaluehastobedefinedinanexecutionrecommendationtotheONIR[1].

ThisdocumentcanbeappliedforcompliancetestsofNRbasestationswithrespecttotheONIR,untilanewversionoranofficialmeasurementrecommendationoftheFederalInsti-tuteofMetrology(METAS)andtheFederalOfficefortheEnvironment(FOEN)ispublished.

Code-selectivemeasurementmethod

Measurand

ThemeasurementmethodisbasedonthedeterminationoftheradiatedfieldproducedbytheSecondarySynchronizationSignal(SSS)ofthedownlinkofthePhysicalBroadcastChannel(PBCH).TheidentificationoftheSS/PBCHbeamidentity(SS/PBCHblockindex)isrequired.TheSSSispartoftheSS/PBCHblockswhicharedistributedoverabandwidthof

3.6MHzupto7.2MHz(forcarrierfrequencyupto6GHz)withintheNRdownlinksignal(seeAnnexA).TheSSSoccupiesabandwidthof1.905MHzor3.810MHz(127resourceelements).TheSS/PBCHblockisingeneralnotcenteredwiththedownlinkcarrierfre-quency.EachSS/PBCHblockoccupiesasetoffourconsecutiveOFDMsymbols.TheSS/PBCHblockcontainstheDemodulationReferenceSignal(DM-RS).TheDM-RSre-sourceelementsoftheSS/PBCHblockcarryinformationonthecellidentitynumber(0to1007)aswellasontheSS/PBCHbeamidentity(SS/PBCHblockindex)[9].MeasurementoftheSSS,aswellasdecodingoftheDM-RSsignal,requiresacode-selectivefieldprobe,ameasuringreceiveroraspectrumanalyzercapableofdecodingNRsignalsandofquantify-ingtheirpower.

ThebandwidthofthemeasuringinstrumentationtoquantifytheSSSisnotspecified,butmustatleastcoverthetotalSSSdownlinksignalbandwidth.TheSSSsignalbandwidthis

127?Δ??,whereastheSS/PBCHblockhasabandwidthof240?Δ??whereΔ??isthesubcarrier

spacingofthePBCHblock.AccordingtoNRnumerology,thesubcarrierspacingcanbe

15kHz,30kHz,and60kHzforcarrierfrequenciesupto6GHz.Thesubcarrierspacingsof120kHzand240kHzareintendedforcarrierfrequenciesabove24GHzaccordingto[8],andtheyarethereforenotfurtherconsideredinthisdocument.Forcarrierfrequenciesupto6GHz,thepossiblesubcarrierspacingsΔ??forthePBCHareonly15kHzand30kHzac-cordingto[10](60kHzisnotusedforPBCH).Differentnumerologies(subcarrierspacing)mightbemultiplexedwithinthesameOFDMsymbolasmentionedin[8].

??,??

Inagivenlocation,themeasurementisperformedasfollows:foreachNRcell??,allmeasur-ableSS/PBCHblocksmustbeidentifiedintermsoftheircellnumber??andSS/PBCHblockindex??(obtainedbydemodulatingtheDM-RSsignal).EachSS/PBCHblockwithindex??cor-respondstoaPBCHantennabeam.ForeachSS/PBCHblock(identifiedbyitsindex??),theelectricfieldstrength??SSS(RE)perresourceelementoftheSSSismeasured.Theelectric

??,??

??,max

fieldstrengths??SSS(RE)ofallSS/PBCHblockswithinahalfframearethenaddedquadrati-callytobuildanewvalue.Thespatialmaximum??SSS(RE)ofthisvaluehastobefoundwithinthemeasurementvolume.Accordingto[10],allSS/PBCHblocksaretransmittedwithinthe

samehalfframe(seeAnnexA.2),andonemightassume[10]thatthishalfframeistransmit-

tedwithaperiodicityof2frames,meaning20ms.

Thespatialmaximumisdeterminedbyscanningthereceiveantennatakingintoaccount:

Standingwavesinthemeasurementvolume

Polarizationofthemeasuringantenna(receiveantenna)

Orientation(azimuthandelevation)ofthemeasuringantenna.Andthefollowingmeasurementconditionsapply:

Minimumdistancetowalls,floor,ceiling,furnitureandwindows:50cm

Heightabovethefloorbetween0.5mand1.75m.

Thereceiveantennausedforthemeasurementsshouldbeofsmalldimensionssothatitmayeasilybeusedindoor.Acalibrationcertificatemustconfirmthetraceabilityofthere-ceiveantennatotheinternationalsystemofunits(SI).

Appreciationvalue

ForeachNR-cell??ofthebasestation,themeasuredvaluetheelectricfieldstrengthhastobeextrapolatedtothereferenceoperatingmode:

?? =??SSS(RE)???(??,??)

??,? ??,max ?? ?? ??

(1)

with

2

??SSS(RE)=max(∑(??SSS(RE)))

??,max √ ??,??

??

(2)

??(??,??)=??SSS(RE)???antenna(??,??)???stat???duplex

?? ?? ?? ?? ?? ?? ?? ??

(3)

Thevariablesaredefinedas

????,? ExtrapolatedvalueoftheelectricfieldstrengthforcelliinV/m.

??,max

??SSS(RE) Spatialmaximumwithinthemeasurementvolumeofthequadraticsum

oftheSSSelectricfieldstrengthperresourceelement(RE)ofallSS/PBCHblocksofcell??asdefinedbyequation(2).Thesumisper-formedonallavailableSS/PBCHblocksindexes??locatedwithinthesamehalfframe.

??,??

??SSS(RE) Electricfieldstrength(inV/m)perresourceelement(RE)oftheSSSof

cell??andSS/PBCHblockindex??.ThisvalueisthequadraticmeanofallmeasuredSSSresourceelementswithinthesameSS/PBCHblock.

????(????,????) Globalextrapolationfactorforcell??.Theglobalfactordependsontheazimuth????andontheelevation????.

??

??SSS(RE) SSSextrapolationfactorforcell??.

??

??antenna(????,????) Antennacorrectionfactortakingintoaccountthedifferencebetween

theantennadiagramoftheSS/PBCHsignalofcell??andtheantenna

diagramofthetotalsignalinthemaximumpermittedoperatingcondi-tion.Theantennacorrectionfactordependsontheazimuth????andontheelevation????.

???? Azimuth,definedasthehorizontalangleinasphericalcoordinatesys-tem,ofthemeasurementlocationwithrespecttothetransmitantennaofcell??.

???? Elevation,definedastheverticalangleinasphericalcoordinatesys-tem,ofthemeasurementlocationwithrespecttothetransmitantennaofcell??.

??

??stat Beamstatisticfactorforcell??.

??duplex Duplexfactor.

Equation(1)issimilartotheextrapolationoftheothermeasuringrecommendations[3,4,5,7],withthedifferenceoftheazimuthandelevationdependence.Ingivensituations,thedepend-enceoftheazimuthandoftheelevationcanbeneglected,thusprovidingauniqueextrapo-lationfactorforeachcell.Thisisdiscussedfurtherinsection4.

Comment

IncontrasttoLTEwherethecellspecificreferencesignalsarepermanentlytransmittedonthesameantennaportsasthepayloaddata,theNRworksdifferently.InNR,thepayloaddataaretransmittedonthePhysicalDownlinkSharedChannel(PDSCH)viathelogicalan-tennaports1000to1011,whereasthesynchronizationandidentificationsignalsaretrans-mittedonthePBCHchannelsusingthelogicalantennaport4000.TheSS/PBCHblockscanbetransmittedonupto4,or8(upto6GHz)differentSS/PBCHbeams.

ThePDSCHchannelhasitsownbeamsthataregenerallymorefocusedthantheSS/PBCHbeams(seeFigure1).ThePDSCHbeamintensitydependsonthepayloaddata,andmightconsequentlyvaryintime.

Forthedeterminationoftheappreciationvalue,theelectricfieldstrengthofthedifferentSS/PBCHblockindexesarecombinedasdefinedinequation(2).ThemotivationtocombinethefieldstrengthofdifferentSS/PBCHblockindexesisfirsttotakeintoaccountthemulti-pathpropagationofthebasestationradiation,andsecondlytoprovidemorerealisticvaluesoftheradiationofthebasestation,especiallyintheregionbetweentwoSS/PBCHbeamsasillustratedbyFigure1.

SS/PBCH

Beam

…

PDSCH

Beam

Antennaof

onecellofabasestation

…

EstimateoftheSS/PBCHradiationdiagramofafterquadraticadditionofthein-

dividualSS/PBCHbeams

Figure1:Schematicrepresentation(seenfromabove)ofthehorizontalradiationpatternofaNR-basestationcell.ThePDSCHbeamsarenotallrepresented.

ExtrapolationfactorfortheSSS

??

Foreachcell??andforeachSS/PBCHblockindex??ofthebasestation,anextrapolationfac-tor??SSS(RE)isdefinedas:

??SSS(RE)= ????,permitted

?? √ SSS(RE)

????

(4)

with

??

??SSS(RE) SSSextrapolationfactorforcell??.

??

??SSS(RE) Actualeffectiveradiatedpower(ERP)perresourceelement(RE)ofthe

SSSoftheSS/PBCHblockofcell??inW.Itcorrespondstothemaxi-muminalldirectionsofthe"summedSSSERPradiationpattern"

??SSS(RE)(??,??),anditisgivenbythefollowingequation:

?? ?? ??

??SSS(RE)=max??SSS(RE)(??,??)

?? ????,?????? ?? ??

(5)

??SSS(RE)(??,??). "summedSSSERPradiationpattern"obtainedbysummingtheERP

?? ?? ??

radiatedpowerperresourceelementofallSS/PBCHbeamsasde-finedbythefollowingequation:

??SSS(RE)(??,??)=∑??SSS(RE)(??,??)

?? ?? ?? ??,?? ?? ??

??

(6)

??SSS(RE)(??,??) Actual"effectiveradiatedpower"perresourceelementinWoftheSSS

??,??

?? ??

oftheSS/PBCHblockofcell??andindex??inthedirectiongivenbytheazimuth????andbytheelevation????.

????,permitted MaximumpermittedERPinW,takingintoaccountthesignalofallan-tennaportsofcell??:PSDCH,PBCH,andPDCCH.

Notes

ThemaximumERP????,permittedreferstothemaximumpermittedERPwithoutanyreduc-tion.

Thepermittedpower????,permitted(accordingtothelocationdatasheet)andtheactual

??

powerofthereferencesignals??SSS(RE)areprovidedbythenetworkoperator.

??

Theactualpowerofthereferencesignals??SSS(RE)isdefinedasthepowerperresourceelement,andnotasthetotalpoweroftheSS/PBCHblock.

AntennaCorrectionFactor

Definition

??

Foreachcell??andforeachazimuth????andelevation????,thecorrespondingextrapolationfactors??antenna(????,????)aredefinedas:

??antenna(????,????)=

??

1 if??SSS(RE)(??,??)<10

?? ?? ??

and??SSS(RE)(??,??)≤??total(??,??)

?? ?? ?? ?? ?? ??

??SSS(RE)(??,??)/??total(??,??) if??SSS(RE)(??,??)<10

?? ?? ?? ?? ?? ?? ?? ?? ??

and??SSS(RE)(??,??)>??total(??,??)

?? ?? ?? ?? ?? ??

??antenna if??SSS(RE)(??,??)≥10

??,max ?? ?? ??

(7)

with

??SSS(RE)

??SSS(RE)(??,??)=√ ??

?? ?? ?? ??SSS(RE)(??,??)

?? ?? ??

(8)

??antenna= max ??SSS(RE)(??,??)/??total(??,??)

??,max SSS(RE) ?? ?? ?? ?? ?? ??

{????,????|???? (????,????)<10}

(9)

Thevariablesaredefinedas

??

??antenna(????,????) Antennacorrectionfactortakingintoaccountthedifferencebetween

theantennadiagramoftheSS/PBCHsignalofcell??andtheantenna

diagramofthetotalsignalinthemaximumpermittedoperatingcondi-tion.Theantennacorrectionfactordependsontheazimuth????andontheelevation????.

??antenna Maximumvalueoftheratio??SSS(RE)(??,??)/??total(??,??),wherethe

??,max

?? ?? ?? ??

?? ??

maximumistakenonalldirectionsforwhichtheattenuation

??SSS(RE)(??,??)oftheSS/PBCHbeamislessthan10(correspondsto

??

20dB).

?? ??

??SSS(RE)(??,??) Attenuation,accordingtoequation(8),ofthe"summedSSSERPradi-

?? ?? ??

ationpattern"ofcell??inthedirectiongivenbytheazimuth????andbytheelevation????,asgivenbyequation(6).Thisratioisgreaterthan1,anditcansometimesbeexpressedindBas

20?log

(??SSS(RE)(??,??)).

10 ??

?? ??

??

??total(????,????) Attenuationofthetotalsignalradiationpatternofcell??inthedirection

givenbytheazimuth????andbytheelevation????.Thetotalradiationpatterncorrespondstotheenvelopeofallworstcaseradiationpatterns

inthepermittedoperationmode.Thisattenuationisdefinedasa"volt-ageratio"(incontrasttoa"powerratio")greaterthan1,anditcansometimesbeexpressedindBas

??

20?log10(??total(????,????)).

????,permitted MaximumpermittedERPinW,takingintoaccountthesignalofallan-tennaportsofcell??:PSDCH,PBCH,andPDCCH.

??SSS(RE)(??,??) "summedSSSERPradiationpattern"obtainedbysummingtheERP

?? ?? ??

radiatedpowerperresourceelementofallSS/PBCHbeamsasde-finedbyequation(6).

??

??SSS(RE) ActualERPperresourceelementoftheSSSoftheSS/PBCHblockof

cell??inW,asdefinedbytheequation(5).

Comment

??

Theantennacorrectionfactor??antenna(????,????)takesintoaccountthedifferencebetweentheantennadiagramoftheSS/PBCHsignalofcell??andtheantennadiagramofthetotalsignal.

"summedSSSERP

radiationpattern"

totalradiationpattern

direction1

direction2

direction4

direction3

Figure2:Schematicrepresentation(seenfromabove)ofthehorizontalradiationpatternofaNR-basestationcell.

Theequation(7)canbeexplainedusingthefollowingFigure2:

Indirection1,wehaveapproximately??SSS(RE)(??,??)?1(0dB)and??total(??,??)?1

?? ?? ?? ?? ?? ??

??

(0dB).Inthiscase,thefirstpartofequation(7)applies:??antenna(????,????)=1.

Indirection2,letusassumethat??SSS(RE)(??,??)=1(0dB)and??total(??,??)=1.1

?? ?? ?? ?? ?? ??

??

(0.83dB).Thefirstpartofequation(7)applies:??antenna(????,????)=1.Thismeansthat

noreductionfactorisapplieddespitethefactthatthetotalradiatedbeamindirection2ismoreattenuatedthantheSS/PBCHbeaminthisdirection.

Indirection3,letusassumethat??SSS(RE)(??,??)=1.25(1.94dB)and??total(??,??)=

?? ?? ?? ?? ?? ??

??

1.1(0.83dB).Thesecondpartofequation(7)applies:??antenna(????,????)=1.14.This

meansthatanextrapolationfactorisappliedtotakeintoaccountthefactthattheSS/PBCHbeaminthisdirectionismoreattenuatedthanthetotalradiatedbeam.

Indirection4,wearebehindthetransmitantenna.Theradiationpatterndoesnotto-tallyvanish,buttheradiationissmallcomparedtoradiationinthefrontdirection.Let

usassumethat??SSS(RE)(??,??)=25(27.96dB)and??total(??,??)=5.0(13.98dB).In

?? ?? ?? ?? ?? ??

thiscase,thethirdpartofequation(7)applies:??antenna(????,????)=??antenna.Thevalue

?? ??,max

??antennaisthemaximumof??antenna(????,????)amongalldirectionsforwhichthe

??,max ??

SS/PBCHbeamissufficientlystrong(??SSS(RE)(??,??)<10).Thisregionisrepre-

?? ?? ??

??

sentedinwhiteinFigure2whereastheregionwherethisconditionisnotfulfilledisrepresentedinlightgrey.Sincetheworstcaseantennacorrectionfactorisapproxi-matelygivenbythedirection3,wehave:??antenna(????,????)?1.14.

Thisexamplesisadidacticillustrationtheequation(7)forahorizontalcutoftheantennadia-gramsasrepresentedinFigure2.However,theequation(7)ismoregeneralanditalsotakesintoaccounttheelevation????.

??

Theantennacorrectionfactors??antenna(????,????)dependonthetypeofantennaandontheori-entationoftheantenna.Thesefactorsmustbeavailable,forexampleinadatabaseorfromtheantennamanufacturer.

Simplifications

??

??,max

Forpracticalreasons,thedirectiondependentantennacorrectionfactors??antenna(????,????)canbesimplifiedtoonevalue??antennaasdefinedbyequation(9).Thissimplificationistotallyac-

ceptabletodeterminetheappreciationvalue.However,itmightleadtoatooimportantover-estimationofthesignalfromtheoperatorpointofview.Inthiscase,differentstrategiesareavailable:

AsillustratedinFigure1,theazimuthaldifferencebetweenthePDSCHbeamandtheSS/PBCHbeamshouldnotsignificant.Therefore,onemightsimplifytheantennacorrec-tionfactoras:

??antenna(????)=max??antenna(????,????)

?? ???? ??

(10)

Theantennacorrectionfactorhasthusonlyadependenceontheelevation????.

Figure3belowillustratesatypicalelevation(verticalcut)differencebetweenthePDSCHbeamandtheSS/PBCHbeam.

BeamoftheSS/PBCH

BeamofthePDSCH

Figure3:Schematicrepresentation(seenfromtheside)oftheverticalradiationpatternofaNR-basestationcell.

??

??

AsshowninFigure3,theantennacorrectionfactor??antenna(????,????)isthelargestformeasurementlocationsclosetothebasestation.TheoperatorcouldreducethepowerofthePDSCHfortheselocationsasshowninFigure4.Afterthisbeamreduction,theover-estimationasaconsequenceoftheuseofonevalueof??antennaforalldirectionsaccord-

ingtoequation(9)issignificantlydecreased.

BeamoftheSS/PBCH

BeamofthePDSCH

Figure4:Schematicrepresentation(seenfromtheside)oftheverticalradiationpatternofaNR-basestationcell,withreductionofthePDSCHbeamsforuserslocatedneartotheantenna.

Beamstatisticfactor

??

ForeachNR-cell??ofthebasestation(resp.installation),astatisticalfactor??statisdefinedtotakeintoaccountthevariabilityofthetransmissiondirectionandoftheantennapatternfromadaptiveantennasaccordingtoannex1,paragraph63oftheONIR[1],intheversionofthe1stofJune2019.

??

Thedefinitionofthestatisticalfactor??statisstillunderstudy.Forthemoment,thefollowing

conservativevalueisconsidered:

??stat=1

??

(11)

Duplexfactor

Theduplexfactor??duplexisdefinedas:

√??DL for TDD

??duplex={1 for TDDwithunknown??

????

1 for FDD

(12)

where??????denotesthemaximumratioofthedownlinktransmissiontimeinatimeinterval.ThischoiceisdeterminedbytheinterpretationoftheE-fieldlimitsasaquadratictimeaver-ageoftheelectricfieldstrength.

Summingallcellsandtechnologies

AllNRcell-specificextrapolatedelectricfieldstrengthvaluesarethensummedtogetheras:

??

???=√∑??2

??,?

??=1

(13)

with

??? ExtrapolatedelectricfieldstrengthofNRforagivennetwork,inV/m.

????,? Extrapolatedelectricfieldstrengthmeasurementforcelli,inV/m.

?? Numberofcellsofthebasestationrespectivelyoftheinstallation.

Finally,theappreciationvalue????isobtainedbysummingthecontributions??Network??,?

??Network??,?ofallnetworksbelongingtothesameinstallation:

??B=√??2 +??2 +?

Network1,? Network2,?

(14)

ExamplesofcalculationscanbefoundinAnnexB.

Forbasestationsrunning,inadditiontoNR,GSM,UMTS,orLTEservicessimultaneously,allthesesignalshavetobetakenintoaccount,and??Bhastobedeterminedaccordingto[5](chap-ter9).

Complianceassessment

Thecomplianceornon-complianceofaninstallationcanbeunequivocallyassessed:

??B≤??limit:Theinstallationfulfillstherequirements.

??B>??limit:Theinstallationdoesnotfulfilltherequirements.

Theexpandedmeasurementuncertainty??(k=2)isnottakenintoaccountdirectlyinthecomplianceassessment(socalled“sharedrisk”or“simpleacceptance”accordingto[13]).However,themeasurementuncertainty??must

includeacontributionof±15%(k=1)forthesamplingofthemeasurementvolume,

notexceedthevalueof±45%(k=2).

Frequencyselectivemethod

Measurand

Thefrequencyselectivemethodisderivedfromthecodeselectivemeasurementmethodde-scribedinequation(1),anditisalsobasedonthemeasurementsofthesecondarysynchro-nizationsignal(SSS).Frequencyselectivemeasurementsofthesynchronizationsignalsre-quireaspectrumanalyzerwithtrueRMS-detector,aminimumresolutionbandwidthoftheSSSbandwidth(127?Δ??)andamaximumhold-function.Themeasurementsareperformedin“ZeroSpan”mode,andthesweeptimemustbechosensothatthemeasuringtimeforonevalueislessthanone-halfofthedurationofanSSSOFDMsymbol.Dependingonthenu-merologyused(15kHzor30kHz),thedurationoftheOFDMsymbolwithoutprefixis

1/15kHz?66μsfor15kHznumerology,and1/30kHz?33μsfor30kHznumerology.

Thespatialmaximumofthesynchronizationsignalshavetobemeasuredasmentionedinthesection2.1.

Appreciationvalue

??,max

Thevalueofthe??SSS(RE)cannotbemeasureddirectlybyafrequencyselectivemeasuringinstrument,sinceitrequiresthequadraticadditionofsignalsfromdifferentSS/PBCHbeams.However,basedonrealisticestimations,thefollowingexpressionisused:

1

??measured?√ ???FSM

??,max 127 ??

(15)

with

??,max

??measured Max&Holdvalueoftheelectricfieldstrengthmeasuredoverthe

wholemeasuringbandwidth(atleastSSSbandwidth)setonthespec-trumanalyzer.

√1?127 Reductionfactortoobtainthefieldstrengthperresourceelement.

??FSM FrequencySelectiveMethod(FSM)factordefinedas??FSM=√2ifthe

?? ??

??

cell??hasmorethanoneSS/PBCHbeam,andas??FSM=1ifthecell??

hasonlyoneSS/PBCHbeam.Ittakesintoaccountthefactthattheelectricfieldproducedbyindividualbeamscannotbemeasured,andthereforecannotbeaddedquadratically.

Themeasuredvalueoftheelectricfieldstrengthhastobeextrapolatedtothereferenceop-eratingmodeas

???(??measured?√1???FSM)?max(??(??,??))

? ??,max 127 ?? ??=1..?? ?? ?? ??

with

(16)

?? Numberofcellsofthebasestationrespectivelyoftheinstallation.

Thefollowingaspectshavetobeconsidered:

Thecenterfrequencyofthemeasuringinstrumenthastobesettothecenterfre-quencyoftheSS/PBCHblock,whichdoesnotingeneralmatchthecenterfrequencyofthedownlinkNRchannel.ThecenterfrequencyoftheSSSmustbegivenbytheoperator.

SincethespectrumanalysercannotdistinguishuplinkanddownlinkinaTDDtrans-missionscheme,itisimportanttoswitchoffeverymobilephoneinthevicinityofthemeasuringsystem.

Finally,theappreciationvalue??Bisobtainedbysummingoverthecontributionsofallnet-workoperatorsandservicesasintheprevioussection(examplesinAnnexB).

Complianceassessment

Overestimationsarehighlyprobablewiththismethod.Thereforethecomplianceofaninstal-lationcanbeassessedwhilenon-compliancecannot:

??B≤??limit: Theinstallationfulfillstherequirements.

??B>??limit: Noassessmentispossible.Forclarification,acodeselectivemeasurementisnecessary.

Literature

“OrdinancerelatingtoProtectionfromNon-IonisingRadiation(ONIR)”(documentNo.814.710)