Proposal for methodology to estimate spectrum requirements for AMS(R)S satellite systems
Sharing of Spectrum Used by Satellite Systems · SHARING OF SPECTRUM USED BY SATELLITE SYSTEMS HOW...
Transcript of Sharing of Spectrum Used by Satellite Systems · SHARING OF SPECTRUM USED BY SATELLITE SYSTEMS HOW...
SHARINGOFSPECTRUMUSEDBYSATELLITESYSTEMS
HOWSATELLITESYSTEMSSHARESPECTRUMAMONGTHEMSELVES,ANDWITHTERRESTRIALSYSTEMS
July 20, 2015
Jose AlbuquerqueChief, Satellite Division
FCC
May 17, 2017
SharingScenariosu SharingBetweenGSOFSSSatelliteNetworks(DirectionalEarth
StationAntennas)
u SharingBetweenNGSOFSSSatelliteSystems(DirectionalEarthStationAntennas)
u SharingBetweenGSOorNGSOSatelliteSystems(Non-DirectionalAntennas)
u Co-FrequencyOperationofGSOandNGSOFSSSatelliteSystems(DirectionalEarthStationAntennas)
u SharingBetweenSatelliteSystems(Earth-to-Space)andTerrestrialSystems
u SharingBetweenSatelliteSystems(Space-to-Earth)andTerrestrialSystems
GeostationaryOrbit(GSO)SatellitesCommunicatingwithDirectionalEarthStationAntennas
u ApplicabletomostGSOfixed-satelliteservice(FSS)satellites
u Spacestationsareauthorizedona“first-come-first-served”basisandhavetoaccommodatelatecomersthatareatleasttwodegreesapartinthegeostationaryorbit
u The“two-degreepolicy”,adoptedin1983andrefinedin2015,strikesabalancebetweenmaintainingflexibilitytoearlycomersandmaximizingopportunitiestolatecomers
u Compatibilityofsatellitenetworkswithspacestationsseparatedbytwodegreesisensuredbylimitingradiationfromearthstationstowardadjacentsatellitesanddownlinke.i.r.p.densityorpower-fluxdensitygeneratedbyspacestations
u Limitscanbeexceededifcoordinatedwithneighboringspacestations
FCCTwo-DegreePolicyversusITUFramework
u Therehasbeenalotofdiscussionbetweenthetworegulatoryregimes,includinginthecommentsandreplycommentsprecedingtheDecember2015Part25Order
u TheITUframeworkisgenerallybasedona“first-come-first-served”principle,butdiffersfromtheFCCtwo-degreeapproachinsomekeypoints,e.g.u Alate-comingITUfilingisacceptedevenifincompatiblewithanearlier
filing;anFCCapplicationthatis“incompatible”withalicenseisdismissedunlesstheincompatibilityhasbeeneliminatedthroughcoordination
u IntheITU,anearlierfilerisexpectedto“accommodate”alatecomer,butthereisnodefinitionofhowmuchaccommodationisrequired;theFCCrulesalsoallowcoordinationbetweentheparties,but,intheabsenceofanagreement,emissionlimitsassociatedwiththetwo-degreepolicyclearlydefinetherightsandobligationsoftheearlycomer
Non-GeostationaryOrbit(NGSO)SatellitesCommunicatingwithDirectionalEarthStationAntennas
u ApplicabletosomeNGSOfixed-satelliteservice(FSS)satellites
u Anapplicationthatcomportswithexistingrulesandiscompatiblewithpreviousauthorizationsandapplicationswillbeputonpublicnoticeandtriggersa“processinground”(applicationscompetingfortheuseofthesamefrequenciescanbesubmitteduntilaspecificdate)
u Allapplicationsthatmeetallrequirementsintherulesaregrantedforalltherequestedspectrum
u Iftwoormorespacestationsofdifferentsystemsarealignedwithanearthstationofoneofthesesystems(orwithinacertainangle,asmeasuredfromtheearthstation),an“in-lineevent”occursandthereispotentialforinterferencebetweenthesystemsinvolved
u Duringin-lineevents,useoftheoverlappingportionsofthespectrumassignedtothesystemsinvolvedhastobecoordinatedbytheparties;intheabsenceofacoordinationagreementtheoverlappingspectrumisdividedequallyamongthepartiesinvolved
FCCversusITUFramework
u TheITUframeworkisagainbasedona“first-come-first-served”principleandtheearlierfilerisexpectedtoaccommodatealatecomer,withoutadefinitionofhowmuchaccommodationisrequired
u TheFCCprocessingroundapproachplacesseveralapplicantsonequalgroundsandmandatesanequalsplitoftheoverlappingspectrumintheabsenceofacoordinationagreementthataddressestheperiodsoftimewhenthereisapotentialforinterference(thiscontrastswiththelackofdefinedoperatingparametersasafallbackintheITUenvironmentwhenthereisnoagreementbetweentheparties)
u OnechallengeintheFCCapproachishowtodealwithapplicationsthatmaycomeinthefuture,afteraprocessingroundhasalreadybeenconductedu Theseapplicationshavetobeconsideredonacase-by-casebasisandoptionsrange
from,ononeextreme,requiringthenewsystemtoprotectallpreviouslyfiledsystemsto,ontheotherextreme,givingthenewsystemthesametreatmentgiventothepreviouslyfiledsystems
NGSOorGSOSatellitesCommunicatingwithNon-DirectionalEarthStationAntennas
u Inthisscenariotherulesprescribeaprocessingroundand,iftheavailablespectrumisnotenoughtomeettherequestsofallapplicationsthatcomportwithexistingrulesandarecompatiblewithpreviousauthorizations,spectrumisequallydividedamongtheapplicants(bandsegmentation)
u AlthoughthecurrentBigLeolicensees(IridiumandGlobalstar)wereauthorizedbeforetheadoptionofthe“modifiedprocessinground”regimein2003,sharinghasbeenachievedthroughbandsegmentation(exceptfor0.95MHzthataresharedbetweenthetwolicensees)
Co-FrequencyOperationofNGSOandGSOFSSSatellitesCommunicating
withDirectionalEarthStationAntennas
u IntheITUframeworkNGSOsystemscannotcauseunacceptableinterferencetoorclaimprotectionfromGSOsatellitenetworks
u IncertainportionsofC-band,Ku-bandandKa-band,theITUhasdevelopedequivalentpowerflux-density(epfd)limitsthat,ifmetbyaNGSOFSSsystem,ensurethatthissystemhasfulfilledtherequirementsofnotcausingunacceptableinterferencetoGSOFSSsatellitenetworksu epfd↓applicabletoNGSOFSSsatelliteemissionsensuretheprotectionofGSOFSS
earthstations
u epfd↑applicabletoemissionsfromearthstationsofaNGSOFSSsystemensuretheprotectionofGSOFSSsatellites
u IntheFCCrulesthereisnowidelyapplicableobligationimposedonNGSOsystems,butthesameepfdlimitsdevelopedbytheITUforportionsKu-bandhavebeenincorporatedintherules(epfdlimitsapplicabletoC-bandandKa-bandfrequenciesarenotintheFCCrulesbuthavebeenusedinFCCgrantsonanadhocbasis)
ExceptionfortheRequirementofNGSOFSSSystemsHavingtoProtect
GSOFSSNetworksu IntheITUframeworkNGSOFSSsystemsandGSOFSSnetworkshave
equalstatusinthefrequencybands18.8-19.3GHz(↓)and28.6-29.1GHz(↑)
u InthesefrequencybandstheITU“first-come-first-served”principleappliesand,asinthecaseofGSOsatellitenetworks,theearlycomerhastoaccommodatethelatecomer,withnocleardefinitionofthelevelofaccommodationrequired
u IntheFCCrules,thefrequencybands18.8-19.3GHz(↓)and28.6-29.1GHz(↑)aredesignatedforNGSOFSSuseu GSOFSSoperationintheband28.6-29.1GHzcanonlybeauthorizedona
secondarybasis
u GSOFSSoperationintheband18.8-19.3GHzcanonlybeauthorizedonanon-interference-non-protectedbasisthroughawaiveroftheU.S.TableofFrequencyAllocations
SharingBetweenSatelliteSystemsandTerrestrialSystems(FS&MS):
SpectrumAllocatedtoEarth-to-SpaceTransmissions(1)u Interferenceisfromterrestrialstationstosatellitereceivers
u Thisinterferencemechanismhasbeentraditionallyaddressedbylimitinge.i.r.p.,requiringdirectionalantennas,andimposingconstraintsonpointingintendedtoprotectGSOsatellites
u Inmostsituations,thisinterferencemechanismhasnotbeenaconcernbecauseaggregateinterferenceisnotsignificant
u Aggregationbecomesaconcernwhenthereispotentialformassiveterrestrialdeployment
u Somehistoricexamplesare:ITUResolutiononWASandRLANsin5GHz;extensivediscussionsarounddeploymentofUWBsystemsintheU.S.
u Morerecently,concernsreappearedinconnectionwith5Gterrestrialdeployment(e.g.discussionsrelatedto5Gmobileservicein27.5-28.35GHz)
u Controllingaggregateinterferencethroughe.i.r.p.limitationsonindividualterrestrialstationsischallenging(undulylimitingdeploymentvs.notprotectingsatellitereceivers)
u Settingalimitforaggregateinterferencebringsthechallengeofenforcingthislimit
SharingBetweenSatelliteSystemsandTerrestrialSystems(FS&MS):
SpectrumAllocatedtoEarth-to-SpaceTransmissions(2)u Interferenceisfromsatelliteearthstationstoterrestrialstationreceivers
u Ifearthstationsandterrestrialstationshaveequalstatusandareindividuallyauthorized,afirst-come-first-servedregimeisappropriateandlatecomershavetoshowcompatibilitywithearlycomersthroughcoordinationtriggeredwhenpre-determinedinterferencethresholdsareexceeded(e.g.5,925-6,425MHz)
u Ifearthstationsorterrestrialstationscanbedeployedanywhere(blanketlicensedearthstationsorterrestrialstationsauthorizedinagivengeographicarea),thetwotypesofstationscannothavethesamestatus
u Ifterrestrialstationshaveahigherstatus,earthstationscanbedeployed:
u withasecondarystatusandmayhavetoceaseoperationsinordertoprotectfutureterrestrialdeployments(concernswithwidespreaddeploymentandpotentialdifficultiesinstoppingtransmissionsfromexistingusersofthesatelliteservice);or
u inawaythatwillprecludeterrestrialdeploymentinverylimitedareas
u Ifearthstationshaveahigherstatus,terrestrialstationsmightbedeployedonanopportunisticbasis(concernswithwidespreaddeploymentandpotentialdifficultiesindealingwithinterferencetoexistingusersoftheterrestrialservice)
SharingBetweenSatelliteSystemsandTerrestrialSystems(FS&MS):
SpectrumAllocatedtoSpaceto-EarthTransmissions(1)
u Interferencefromterrestrialstationstoearthstationreceivers
u Ifearthstationsandterrestrialstationshaveequalstatusandareindividuallyauthorized,afirst-come-first-servedregimeisappropriateandlatecomershavetoshowcompatibilitywithearlycomersthroughcoordinationtriggeredwhenpre-determinedinterferencethresholdsareexceeded(e.g.3,700-4,200MHz)
u Ifearthstationsorterrestrialstationscanbedeployedanywhere(blanketlicensedearthstationsorterrestrialstationsauthorizedinagivengeographicarea),thetwotypesofstationscannothavethesamestatus
u Ifterrestrialstationshaveahigherstatus,earthstationscanbedeployed:u withasecondarystatusandhavetooperateonanon-protectedbasis(concernswithwidespreaddeployment
andpotentialdifficultiesindealingwithinterferencetoexistingusersofthesatelliteservice);or
u inawaythatwillprecludeterrestrialdeploymentinverylimitedareas
u Ifearthstationshaveahigherstatus,terrestrialstationsmightbedeployedwithasecondarystatusandmayhavetoceaseoperationsinordertoprotectfutureearthstations(concernswithwidespreaddeploymentandpotentialdifficultiesinstoppingtransmissionsfromexistingusersoftheterrestrialservice)
SharingBetweenSatelliteSystemsandTerrestrialSystems(FS&MS):
SpectrumAllocatedtoSpaceto-EarthTransmissions(2)u Interferencefromsatellitetransmitterstoterrestrialstationsreceivers
u Thisinterferencemechanismhasbeentraditionallyaddressedbysettinglimitstothespectralpowerflux-density(pfd)thatsatellitetransmissionscangenerateonthesurfaceoftheEarth
u WhenapplyingthesepfdlimitstoNGSOconstellations,twoissueshavetobeaddressedu ThepfdgeneratedbyaNGSOconstellationatanygivenpointonthegroundvaries
withtimeandinthiscontextitmightbeappropriatetodefineapfdthatisexceededonlyforacertainpercentageofthetimeratherthanapfdthatcanneverbeexceeded(developinganepfdlimitmayalsobeanoptionbutthiswouldhavetobeassociatedwithacertaincollectionofterrestrialstationantennas)
u ThecurrentFCCandITUrulesestablishpfdlimitsperspacestationwhileforNGSOconstellationstheaggregatepfdshouldbelimited(currentlyonlyinthefrequencyband18.8-19.3GHzthereisacorrectionfactortotakeintoaccountthenumberofsatellitesintheconstellationandeventhiscorrectionfactorisnotappropriateforlargerconstellations)