NR测量方法说明 2.1

TechnicalReport5G–18.02.2020

©METAS

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FederalInstituteofMetrologyMETAS

TechnicalReport:MeasurementMethodfor5GNRBaseStationsupto6GHz

18February2020

(Version2.1from20April2020)

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

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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∙Δ𝑓,whereastheSS/PBCHblockhasabandwidthof240∙Δ𝑓whereΔ𝑓isthesubcarrier

spacingofthePBCHblock.AccordingtoNRnumerology,thesubcarrierspacingcanbe

15kHz,30kHz,and60kHzforcarrierfrequenciesupto6GHz.Thesubcarrierspacingsof120kHzand240kHzareintendedforcarrierfrequenciesabove24GHzaccordingto[8],andtheyarethereforenotfurtherconsideredinthisdocument.Forcarrierfrequenciesupto6GHz,thepossiblesubcarrierspacingsΔ𝑓forthePBCHareonly15kHzand30kHzac-cordingto[10](60kHzisnotusedforPBCH).Differentnumerologies(subcarrierspacing)mightbemultiplexedwithinthesameOFDMsymbolasmentionedin[8].

𝑖,𝑗

Inagivenlocation,themeasurementisperformedasfollows:foreachNRcell𝑖,allmeasur-ableSS/PBCHblocksmustbeidentifiedintermsoftheircellnumber𝑖andSS/PBCHblockindex𝑗(obtainedbydemodulatingtheDM-RSsignal).EachSS/PBCHblockwithindex𝑗cor-respondstoaPBCHantennabeam.ForeachSS/PBCHblock(identifiedbyitsindex𝑗),theelectricfieldstrength𝐸SSS(RE)perresourceelementoftheSSSismeasured.Theelectric

𝑖,𝑗

𝑖,max

fieldstrengths𝐸SSS(RE)ofallSS/PBCHblockswithinahalfframearethenaddedquadrati-callytobuildanewvalue.Thespatialmaximum𝐸SSS(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-cell𝑖ofthebasestation,themeasuredvaluetheelectricfieldstrengthhastobeextrapolatedtothereferenceoperatingmode:

𝐸 =𝐸SSS(RE)∙𝐾(𝜑,𝜃)

𝑖,ℎ 𝑖,max 𝑖 𝑖 𝑖

(1)

with

2

𝐸SSS(RE)=max(∑(𝐸SSS(RE)))

𝑖,max √ 𝑖,𝑗

𝑗

(2)

𝐾(𝜑,𝜃)=𝐾SSS(RE)∙𝐾antenna(𝜑,𝜃)∙𝐾stat∙𝐾duplex

𝑖 𝑖 𝑖 𝑖 𝑖 𝑖 𝑖 𝑖

(3)

Thevariablesaredefinedas

𝐸𝑖,ℎ ExtrapolatedvalueoftheelectricfieldstrengthforcelliinV/m.

𝑖,max

𝐸SSS(RE) Spatialmaximumwithinthemeasurementvolumeofthequadraticsum

oftheSSSelectricfieldstrengthperresourceelement(RE)ofallSS/PBCHblocksofcell𝑖asdefinedbyequation(2).Thesumisper-formedonallavailableSS/PBCHblocksindexes𝑗locatedwithinthesamehalfframe.

𝑖,𝑗

𝐸SSS(RE) Electricfieldstrength(inV/m)perresourceelement(RE)oftheSSSof

cell𝑖andSS/PBCHblockindex𝑗.ThisvalueisthequadraticmeanofallmeasuredSSSresourceelementswithinthesameSS/PBCHblock.

𝐾𝑖(𝜑𝑖,𝜃𝑖) Globalextrapolationfactorforcell𝑖.Theglobalfactordependsontheazimuth𝜑𝑖andontheelevation𝜃𝑖.

𝑖

𝐾SSS(RE) SSSextrapolationfactorforcell𝑖.

𝑖

𝐾antenna(𝜑𝑖,𝜃𝑖) Antennacorrectionfactortakingintoaccountthedifferencebetween

theantennadiagramoftheSS/PBCHsignalofcell𝑖andtheantenna

diagramofthetotalsignalinthemaximumpermittedoperatingcondi-tion.Theantennacorrectionfactordependsontheazimuth𝜑𝑖andontheelevation𝜃𝑖.

𝜑𝑖 Azimuth,definedasthehorizontalangleinasphericalcoordinatesys-tem,ofthemeasurementlocationwithrespecttothetransmitantennaofcell𝑖.

𝜃𝑖 Elevation,definedastheverticalangleinasphericalcoordinatesys-tem,ofthemeasurementlocationwithrespecttothetransmitantennaofcell𝑖.

𝑖

𝐾stat Beamstatisticfactorforcell𝑖.

𝐾duplex 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

𝑖

Foreachcell𝑖andforeachSS/PBCHblockindex𝑗ofthebasestation,anextrapolationfac-tor𝐾SSS(RE)isdefinedas:

𝐾SSS(RE)= 𝑃𝑖,permitted

𝑖 √ SSS(RE)

𝑃𝑖

(4)

with

𝑖

𝐾SSS(RE) SSSextrapolationfactorforcell𝑖.

𝑖

𝑃SSS(RE) Actualeffectiveradiatedpower(ERP)perresourceelement(RE)ofthe

SSSoftheSS/PBCHblockofcell𝑖inW.Itcorrespondstothemaxi-muminalldirectionsofthe"summedSSSERPradiationpattern"

𝑃SSS(RE)(𝜑,𝜃),anditisgivenbythefollowingequation:

𝑖 𝑖 𝑖

𝑃SSS(RE)=max𝑃SSS(RE)(𝜑,𝜃)

𝑖 𝜑𝑖,𝜃𝑖𝑖 𝑖 𝑖

(5)

𝑃SSS(RE)(𝜑,𝜃). "summedSSSERPradiationpattern"obtainedbysummingtheERP

𝑖 𝑖 𝑖

radiatedpowerperresourceelementofallSS/PBCHbeamsasde-finedbythefollowingequation:

𝑃SSS(RE)(𝜑,𝜃)=∑𝑃SSS(RE)(𝜑,𝜃)

𝑖 𝑖 𝑖 𝑖,𝑗 𝑖 𝑖

𝑗

(6)

𝑃SSS(RE)(𝜑,𝜃) Actual"effectiveradiatedpower"perresourceelementinWoftheSSS

𝑖,𝑗

𝑖 𝑖

oftheSS/PBCHblockofcell𝑖andindex𝑗inthedirectiongivenbytheazimuth𝜑𝑖andbytheelevation𝜃𝑖.

𝑃𝑖,permitted MaximumpermittedERPinW,takingintoaccountthesignalofallan-tennaportsofcell𝑖:PSDCH,PBCH,andPDCCH.

Notes

ThemaximumERP𝑃𝑖,permittedreferstothemaximumpermittedERPwithoutanyreduc-tion.

Thepermittedpower𝑃𝑖,permitted(accordingtothelocationdatasheet)andtheactual

𝑖

powerofthereferencesignals𝑃SSS(RE)areprovidedbythenetworkoperator.

𝑖

Theactualpowerofthereferencesignals𝑃SSS(RE)isdefinedasthepowerperresourceelement,andnotasthetotalpoweroftheSS/PBCHblock.

AntennaCorrectionFactor

Definition

𝑖

Foreachcell𝑖andforeachazimuth𝜑𝑖andelevation𝜃𝑖,thecorrespondingextrapolationfactors𝐾antenna(𝜑𝑖,𝜃𝑖)aredefinedas:

𝐾antenna(𝜑𝑖,𝜃𝑖)=

𝑖

1 if𝐴SSS(RE)(𝜑,𝜃)<10

𝑖 𝑖 𝑖

and𝐴SSS(RE)(𝜑,𝜃)≤𝐴total(𝜑,𝜃)

𝑖 𝑖 𝑖 𝑖 𝑖 𝑖

𝐴SSS(RE)(𝜑,𝜃)/𝐴total(𝜑,𝜃) if𝐴SSS(RE)(𝜑,𝜃)<10

𝑖 𝑖 𝑖 𝑖 𝑖 𝑖 𝑖 𝑖 𝑖

and𝐴SSS(RE)(𝜑,𝜃)>𝐴total(𝜑,𝜃)

𝑖 𝑖 𝑖 𝑖 𝑖 𝑖

𝐾antenna if𝐴SSS(RE)(𝜑,𝜃)≥10

𝑖,max 𝑖 𝑖 𝑖

(7)

with

𝑃SSS(RE)

𝐴SSS(RE)(𝜑,𝜃)=√ 𝑖

𝑖 𝑖 𝑖 𝑃SSS(RE)(𝜑,𝜃)

𝑖 𝑖 𝑖

(8)

𝐾antenna= max 𝐴SSS(RE)(𝜑,𝜃)/𝐴total(𝜑,𝜃)

𝑖,max SSS(RE) 𝑖 𝑖 𝑖 𝑖 𝑖 𝑖

{𝜑𝑖,𝜃𝑖|𝐴𝑖 (𝜑𝑖,𝜃𝑖)<10}

(9)

Thevariablesaredefinedas

𝑖

𝐾antenna(𝜑𝑖,𝜃𝑖) Antennacorrectionfactortakingintoaccountthedifferencebetween

theantennadiagramoftheSS/PBCHsignalofcell𝑖andtheantenna

diagramofthetotalsignalinthemaximumpermittedoperatingcondi-tion.Theantennacorrectionfactordependsontheazimuth𝜑𝑖andontheelevation𝜃𝑖.

𝐾antenna Maximumvalueoftheratio𝐴SSS(RE)(𝜑,𝜃)/𝐴total(𝜑,𝜃),wherethe

𝑖,max

𝑖 𝑖 𝑖 𝑖

𝑖 𝑖

maximumistakenonalldirectionsforwhichtheattenuation

𝐴SSS(RE)(𝜑,𝜃)oftheSS/PBCHbeamislessthan10(correspondsto

𝑖

20dB).

𝑖 𝑖

𝐴SSS(RE)(𝜑,𝜃) Attenuation,accordingtoequation(8),ofthe"summedSSSERPradi-

𝑖 𝑖 𝑖

ationpattern"ofcell𝑖inthedirectiongivenbytheazimuth𝜑𝑖andbytheelevation𝜃𝑖,asgivenbyequation(6).Thisratioisgreaterthan1,anditcansometimesbeexpressedindBas

20∙log

(𝐴SSS(RE)(𝜑,𝜃)).

10 𝑖

𝑖 𝑖

𝑖

𝐴total(𝜑𝑖,𝜃𝑖) Attenuationofthetotalsignalradiationpatternofcell𝑖inthedirection

givenbytheazimuth𝜑𝑖andbytheelevation𝜃𝑖.Thetotalradiationpatterncorrespondstotheenvelopeofallworstcaseradiationpatterns

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

𝑖

20∙log10(𝐴total(𝜑𝑖,𝜃𝑖)).

𝑃𝑖,permitted MaximumpermittedERPinW,takingintoaccountthesignalofallan-tennaportsofcell𝑖:PSDCH,PBCH,andPDCCH.

𝑃SSS(RE)(𝜑,𝜃) "summedSSSERPradiationpattern"obtainedbysummingtheERP

𝑖 𝑖 𝑖

radiatedpowerperresourceelementofallSS/PBCHbeamsasde-finedbyequation(6).

𝑖

𝑃SSS(RE) ActualERPperresourceelementoftheSSSoftheSS/PBCHblockof

cell𝑖inW,asdefinedbytheequation(5).

Comment

𝑖

Theantennacorrectionfactor𝐾antenna(𝜑𝑖,𝜃𝑖)takesintoaccountthedifferencebetweentheantennadiagramoftheSS/PBCHsignalofcell𝑖andtheantennadiagramofthetotalsignal.

"summedSSSERP

radiationpattern"

totalradiationpattern

direction1

direction2

direction4

direction3

Figure2:Schematicrepresentation(seenfromabove)ofthehorizontalradiationpatternofaNR-basestationcell.

Theequation(7)canbeexplainedusingthefollowingFigure2:

Indirection1,wehaveapproximately𝐴SSS(RE)(𝜑,𝜃)≅1(0dB)and𝐴total(𝜑,𝜃)≅1

𝑖 𝑖 𝑖 𝑖 𝑖 𝑖

𝑖

(0dB).Inthiscase,thefirstpartofequation(7)applies:𝐾antenna(𝜑𝑖,𝜃𝑖)=1.

Indirection2,letusassumethat𝐴SSS(RE)(𝜑,𝜃)=1(0dB)and𝐴total(𝜑,𝜃)=1.1

𝑖 𝑖 𝑖 𝑖 𝑖 𝑖

𝑖

(0.83dB).Thefirstpartofequation(7)applies:𝐾antenna(𝜑𝑖,𝜃𝑖)=1.Thismeansthat

noreductionfactorisapplieddespitethefactthatthetotalradiatedbeamindirection2ismoreattenuatedthantheSS/PBCHbeaminthisdirection.

Indirection3,letusassumethat𝐴SSS(RE)(𝜑,𝜃)=1.25(1.94dB)and𝐴total(𝜑,𝜃)=

𝑖 𝑖 𝑖 𝑖 𝑖 𝑖

𝑖

1.1(0.83dB).Thesecondpartofequation(7)applies:𝐾antenna(𝜑𝑖,𝜃𝑖)=1.14.This

meansthatanextrapolationfactorisappliedtotakeintoaccountthefactthattheSS/PBCHbeaminthisdirectionismoreattenuatedthanthetotalradiatedbeam.

Indirection4,wearebehindthetransmitantenna.Theradiationpatterndoesnotto-tallyvanish,buttheradiationissmallcomparedtoradiationinthefrontdirection.Let

usassumethat𝐴SSS(RE)(𝜑,𝜃)=25(27.96dB)and𝐴total(𝜑,𝜃)=5.0(13.98dB).In

𝑖 𝑖 𝑖 𝑖 𝑖 𝑖

thiscase,thethirdpartofequation(7)applies:𝐾antenna(𝜑𝑖,𝜃𝑖)=𝐾antenna.Thevalue

𝑖 𝑖,max

𝐾antennaisthemaximumof𝐾antenna(𝜑𝑖,𝜃𝑖)amongalldirectionsforwhichthe

𝑖,max 𝑖

SS/PBCHbeamissufficientlystrong(𝐴SSS(RE)(𝜑,𝜃)<10).Thisregionisrepre-

𝑖 𝑖 𝑖

𝑖

sentedinwhiteinFigure2whereastheregionwherethisconditionisnotfulfilledisrepresentedinlightgrey.Sincetheworstcaseantennacorrectionfactorisapproxi-matelygivenbythedirection3,wehave:𝐾antenna(𝜑𝑖,𝜃𝑖)≅1.14.

Thisexamplesisadidacticillustrationtheequation(7)forahorizontalcutoftheantennadia-gramsasrepresentedinFigure2.However,theequation(7)ismoregeneralanditalsotakesintoaccounttheelevation𝜃𝑖.

𝑖

Theantennacorrectionfactors𝐾antenna(𝜑𝑖,𝜃𝑖)dependonthetypeofantennaandontheori-entationoftheantenna.Thesefactorsmustbeavailable,forexampleinadatabaseorfromtheantennamanufacturer.

Simplifications

𝑖

𝑖,max

Forpracticalreasons,thedirectiondependentantennacorrectionfactors𝐾antenna(𝜑𝑖,𝜃𝑖)canbesimplifiedtoonevalue𝐾antennaasdefinedbyequation(9).Thissimplificationistotallyac-

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

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

𝐾antenna(𝜃𝑖)=max𝐾antenna(𝜑𝑖,𝜃𝑖)

𝑖 𝜑𝑖 𝑖

(10)

Theantennacorrectionfactorhasthusonlyadependenceontheelevation𝜃𝑖.

Figure3belowillustratesatypicalelevation(verticalcut)differencebetweenthePDSCHbeamandtheSS/PBCHbeam.

BeamoftheSS/PBCH

BeamofthePDSCH

Figure3:Schematicrepresentation(seenfromtheside)oftheverticalradiationpatternofaNR-basestationcell.

𝑖

𝑖

AsshowninFigure3,theantennacorrectionfactor𝐾antenna(𝜑𝑖,𝜃𝑖)isthelargestformeasurementlocationsclosetothebasestation.TheoperatorcouldreducethepowerofthePDSCHfortheselocationsasshowninFigure4.Afterthisbeamreduction,theover-estimationasaconsequenceoftheuseofonevalueof𝐾antennaforalldirectionsaccord-

ingtoequation(9)issignificantlydecreased.

BeamoftheSS/PBCH

BeamofthePDSCH

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

Beamstatisticfactor

𝑖

ForeachNR-cell𝑖ofthebasestation(resp.installation),astatisticalfactor𝐾statisdefinedtotakeintoaccountthevariabilityofthetransmissiondirectionandoftheantennapatternfromadaptiveantennasaccordingtoannex1,paragraph63oftheONIR[1],intheversionofthe1stofJune2019.

𝑖

Thedefinitionofthestatisticalfactor𝐾statisstillunderstudy.Forthemoment,thefollowing

conservativevalueisconsidered:

𝐾stat=1

𝑖

(11)

Duplexfactor

Theduplexfactor𝐾duplexisdefinedas:

√𝑟DL for TDD

𝐾duplex={1 for TDDwithunknown𝑟

𝐷𝐿

1 for FDD

(12)

where𝑟𝐷𝐿denotesthemaximumratioofthedownlinktransmissiontimeinatimeinterval.ThischoiceisdeterminedbytheinterpretationoftheE-fieldlimitsasaquadratictimeaver-ageoftheelectricfieldstrength.

Summingallcellsandtechnologies

AllNRcell-specificextrapolatedelectricfieldstrengthvaluesarethensummedtogetheras:

𝑛

𝐸ℎ=√∑𝐸2

𝑖,ℎ

𝑖=1

(13)

with

𝐸ℎ ExtrapolatedelectricfieldstrengthofNRforagivennetwork,inV/m.

𝐸𝑖,ℎ Extrapolatedelectricfieldstrengthmeasurementforcelli,inV/m.

𝑛 Numberofcellsofthebasestationrespectivelyoftheinstallation.

Finally,theappreciationvalue𝐸𝐵isobtainedbysummingthecontributions𝐸Network𝑗,ℎ

𝐸Network𝑘,ℎofallnetworksbelongingtothesameinstallation:

𝐸B=√𝐸2 +𝐸2 +⋯

Network1,ℎ Network2,ℎ

(14)

ExamplesofcalculationscanbefoundinAnnexB.

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

Complianceassessment

Thecomplianceornon-complianceofaninstallationcanbeunequivocallyassessed:

𝐸B≤𝐸limit:Theinstallationfulfillstherequirements.

𝐸B>𝐸limit:Theinstallationdoesnotfulfilltherequirements.

Theexpandedmeasurementuncertainty𝑈(k=2)isnottakenintoaccountdirectlyinthecomplianceassessment(socalled“sharedrisk”or“simpleacceptance”accordingto[13]).However,themeasurementuncertainty𝑈must

includeacontributionof±15%(k=1)forthesamplingofthemeasurementvolume,

notexceedthevalueof±45%(k=2).

Frequencyselectivemethod

Measurand

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

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

Thespatialmaximumofthesynchronizationsignalshavetobemeasuredasmentionedinthesection2.1.

Appreciationvalue

𝑖,max

Thevalueofthe𝐸SSS(RE)cannotbemeasureddirectlybyafrequencyselectivemeasuringinstrument,sinceitrequiresthequadraticadditionofsignalsfromdifferentSS/PBCHbeams.However,basedonrealisticestimations,thefollowingexpressionisused:

1

𝐸measured∙√ ∙𝐾FSM

𝑖,max 127 𝑖

(15)

with

𝑖,max

𝐸measured Max&Holdvalueoftheelectricfieldstrengthmeasuredoverthe

wholemeasuringbandwidth(atleastSSSbandwidth)setonthespec-trumanalyzer.

√1⁄127 Reductionfactortoobtainthefieldstrengthperresourceelement.

𝐾FSM FrequencySelectiveMethod(FSM)factordefinedas𝐾FSM=√2ifthe

𝑖 𝑖

𝑖

cell𝑖hasmorethanoneSS/PBCHbeam,andas𝐾FSM=1ifthecell𝑖

hasonlyoneSS/PBCHbeam.Ittakesintoaccountthefactthattheelectricfieldproducedbyindividualbeamscannotbemeasured,andthereforecannotbeaddedquadratically.

Themeasuredvalueoftheelectricfieldstrengthhastobeextrapolatedtothereferenceop-eratingmodeas

𝐸≅(𝐸measured∙√1∙𝐾FSM)∙max(𝐾(𝜑,𝜃))

ℎ 𝑖,max 127 𝑖 𝑖=1..𝑛 𝑖 𝑖 𝑖

with

(16)

𝑛 Numberofcellsofthebasestationrespectivelyoftheinstallation.

Thefollowingaspectshavetobeconsidered:

Thecenterfrequencyofthemeasuringinstrumenthastobesettothecenterfre-quencyoftheSS/PBCHblock,whichdoesnotingeneralmatchthecenterfrequencyofthedownlinkNRchannel.ThecenterfrequencyoftheSSSmustbegivenbytheoperator.

SincethespectrumanalysercannotdistinguishuplinkanddownlinkinaTDDtrans-missionscheme,itisimportanttoswitchoffeverymobilephoneinthevicinityofthemeasuringsystem.

Finally,theappreciationvalue𝐸Bisobtainedbysummingoverthecontributionsofallnet-workoperatorsandservicesasintheprevioussection(examplesinAnnexB).

Complianceassessment

Overestimationsarehighlyprobablewiththismethod.Thereforethecomplianceofaninstal-lationcanbeassessedwhilenon-compliancecannot:

𝐸B≤𝐸limit: Theinstallationfulfillstherequirements.

𝐸B>𝐸limit: Noassessmentispossible.Forclarification,acodeselectivemeasurementisnecessary.

Literature

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