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NetWorld2020’s–SatComWGTheroleofsatellitesin5G

Version5 – 31th July 2014

1 Introduction

Thisdocumentoutlines thevisionof thesatelliteworkinggroupofNETWORLD2020as to therole that satelliteswillplay in future5Gnetworks. It is seen that satelliteswill integratewithothernetworksratherthanbeastandalonenetworktoprovide5Ganditisthisintegrationthatformsthecoreofthevision.Satellitesystemsarefundamentalcomponents todeliverreliably5Gservices notonlyacross thewholeof Europebutalsoinallregionsoftheworld,allthetimeandat an affordable cost. Thanks to their inherent characteristics the satellite component willcontribute to augment the 5G service capability and address someof themajor challenges inrelationtothesupportofmultimediatrafficgrowth,ubiquitouscoverage,machinetomachinecommunicationsandcriticaltelecommissionswhilstoptimisingthevalueformoneytotheend-users.

After elaborating on the 5G vision, this document presents the trends in satellitecommunications. So-called “satellite use cases” are thendefinedwhich illustrate how satelliteserviceswill contribute to the 5G KPIs. The document also identifies the associated researchtopics thatneed tobe carried out in the contextofH2020 ICT5GPPPprogram toenable thissatellite integration to 5G universal deployment. Lastly, the related technology roadmap isconsolidated and the expected contribution of satellite communications to the 5G KPIs isassessed.

2 The5Gvision

2.1 Whatis5Gabout

The vision of 5G mobile [1,2,3] is driven from the predictions of up to 1000 times datarequirement by 2020 and the fact that the traffic could be 2/3rds video embedded. If onetensions this with the mobile spectrum available (by 2015 about 500MHz) there is, what isreferedtoasthe‘spectrumcrunch’—therejustisn’tsufficienttosatisfythedemands.Althoughtherecanandshouldbemovestousethespectrummoreefficientlyegbyspectrumaggregationand sharing schemes this is still considered insufficient. Thus the conclusion is tomove to amore dense network (Densification) and increase the area spectral efficiency by orders ofmagnitude. This leads to a network of much smaller cells, all of which will not be solelyhomogeneous but a flexible heterogeneous network where the resources can be adapteddynamically(ondemand)astheusersdemandinspace,timeandspectralresourcesandevenbetweenoperatorsvaries.Thisrequiresafundamentalredesignofthecellularnetworkswhichstillhavealegacyofcellularnetworkingbasedupon3Gwhichresultinexcessiveandinefficientsignalling inhibiting theadoptionofnewservicetypes.Thetrendnowistowards ‘InformationCentricNetworks’designedwiththeuserinmindandtheirrequirementstoaccessinformationefficientlyandwithagoodQoE.Thistiesinwellwiththecloudapproachtoservicedeliveryandnetworkarchitecture—the’softwaredefinednetworkapproach’. Serviceproviderswillneedtouse this network in bespokeways and thus virtualisation of functions is key so that a virtualprovisioncanbemadeinaquickand easyway.Virtualisationandmultitenancyarekeyaspectsofthe5Gvision.

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Another key driver for 5G is the emergence of IoT and the vision of Billions of objects beingconnected to the internet. This is the enabler to ‘smart cities’ and other such ‘smart’;environments and the emergence of what is called ‘Big Data’ applications where massiveamounts of data can beprocessed to feed a plethora of new applications. For 5G this impliesbeing able to handle large quantities of low data communications efficiently coveringwidespreadsensornetworksandM2Mcommunications.

Therearetworemainingpillarsofthe5Gvision.Thefirstisensuringavailability,reliabilityandrobustness.Theabstractionorvirtualisationtechniquesmentionedaboveandthecloudnatureof the services raises complex issues for critical services and security as the point on whichservicesor content couldbedeliveredwill beoperated over severalheterogeneousnetworksmanagedpossiblybydifferententities.Thewholeendtoendmanagementthenbecomesarealissue. The second and increasingly important issue is that of reducing energy. The target is areductionby90%oftoday’senergyby2020atno reductioninperformanceandincreaseincost.Thus 5G network design becomes a complex task involving link and area spectral efficiencytogetherwithenergyefficiency.

2.2 The5GresearchKPIs

SeveralKeyPerformanceIndicators(KPI)havebeendefinedintheframeofthe5GPPPcontactto qualify the 5G solutions, architectures, technologies and standards for the ubiquitous 5Gcommunication infrastructures. The Performance an societal KPIs are recalled herewhile thenextchapterswilldescribehowsatellitetechnologiesintegratedwithinthe5GnetworkcorewillcontributetotheachievementofsuchambitiousKPIsaspresentedinthenextparagraphs.

PerformanceKPIs:

KPI#1:Providing1000timeshigherwirelessareacapacityandmorevariedservicecapabilitiescomparedto2010.

KPI #2: Reducing the average service creation time cycle from 90 hours to 90 minutes (ascomparedtotheequivalenttimecyclein2010).

KPI#3:Verydensedeploymentstoconnectover7trillionwirelessdevicesservingover7billionpeople.

KPI #4: Secure, reliable and dependable Internet with zero perceived downtime for servicesprovision.

SocietalKPIs:

KPI#5:EnablingadvancedUsercontrolledprivacy

KPI#6:Reductionofenergyconsumptionperserviceupto90%(ascomparedto2010)

KPI#7:Europeanavailabilityofacompetitiveindustrialofferfor5Gsystemsandtechnologies

KPI #8: New economically viable services of high societal value like U-HDTV and M2Mapplications

KPI#9:Establishmentandavailabilityof5GskillsdevelopmentcurriculainpartnershipwiththeEIT

3 SatComtrends

Mobilesatellitestodayprovideservicestoair,seaandremotelandareasviaGEOoperators(e.gInmarsat,Thuraya)andnonGEOoperators(e.g.Iridium,Globalstar, O3b). TheseoperateinL,Sand more recently Ka bands, to both handheld and vehicle mounted as well as some fixedterminals.Air interfaces andnetwork functionshave tended tobeproprietaryalthough some

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integrationwithMSSand3GPPnetworkinterfacesexist.Fixedsatellitestodayprovide backhaulservicestocellularinC,KuandKabands,andalsoservicestomovingfixedterminalsonvehiclesinC-,Ku-,X- andKa-bands.Satellitehasbeenanoverlay,ratherthanintegratedsystemexceptinSbandwhereanintegratedsatelliteandterrestrialMSSstandardhasbeenadopted.

3GPPlikeservicesexistviasatellitetoindividualusers,butasyetthesehavenotbeenextendedto4G.Satelliteservices toships,aircraftandfasttrainsusingFSSsatellitesprovideafullrangeofmobile and broadcast services to passenger vehicles. A growing area of interest is in thetransportsectorwheresafetyservicesandV2V (VehicleToVehicle) areseenasidealforsatellitedelivery. Satellite is also used extensively for low rate SCADA (Supervisory Control and DataAcquisition) applications dealingwithremoteinstallationssuchasto/frompipelines,oilandgasetc.Satelliteisalsousedincasesoffailureinthecellularsystemduetonaturalormade-madedisasters.Increaseddatarequirementsforapplicationssuchasoilandothermineral explorationand security via UAV’s has spurred the need for more spectrum and the use of higherfrequencies suchasKa-band.

Although not the topic of this paper we should mention the GPS and Galileo navigation andpositioningsatelliteswhichplayakeyroleinlocationbasedservicesandinsupportingmobilesatelliteandcellularsystemsmanagement.

Looking towards the future to 2020/5 therewillbea trend to largerandmorepowerfulGEOsatellitestakingcapacitiesfrom100’sGbpstooveraTerabit/s.Severalhundredsofspotbeamswill, via higher order frequency reuse increase the capacity in limited spectrum. Higherfrequencybandsmay alsobeused—Q/V/Wandalsoopticalforgatewayconnections.Advancesinsatellitepayloadtechnologyvianewmaterialsandoptimiseddesignswillenableupto30mdeployableantennasatL/Sbandsand increasedpayloadpowers from20 to30KW.Onboardsignal processing will enable improved connectivity and flexibility to meet changing trafficpatternsanddemandse.g.adaptivebeamformingandhoppingandinterferencemanagementtoincrease capacity. Alternative architectures involving clusters of GEO’s and possiblyfragmentationoflinkfunctionsbetweentheconnected(possiblywithISL’s)clusteredsatellitesmay evolve.Followingtherecent innovative useof differentorbits,newnonGEOsystemsarelikely toappearpossibly usingalloptical technology—betweensatellitesand fromsatellite togroundandpossiblyusingconstellationsofsmallerandcheapersatellites.

Satellite and terrestrial system integration is already a trend and this will continue with thedevelopment of interoperability standards to allow the two sectors to interconnect efficientlybothatnetwork levelandat IP levels.This formof technological complementarity, relyingonnetworkhybridation,isalreadyareality.Indeed,OrangeproposesaTriplePlayoffer(internet,TV,phone)relyingontheADSLnetworkfortheinternetserviceandonthesatellitefortheTVservicestothosesubscriberswhocannotreceiveitthroughADSL.

Inadditionmobilitymanagementintegrationwillevolveacrossthelargersatelliteandsmallerterrestrialcells.

Satellite communications systems encompass a wide range of solutions providingcommunicationservicesviasatellite(s)asillustratedinFigure1.

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Figure 1:Sketchofsatelliteroleintegratedinfuturecommunicationsystems1

SatCom systems can address a wide range of services such as broadcast, broadband andnarrowbandservicestofixed,portableandmobileterminalsoverglobalorregionalcoverage:

BroadcastsystemshavebeenoptimizedtodeliverTVprograms. Broadbandservices supportIPservices Mostmobilesatelliteservices aredelivering3G-like services

Amongothers,thefollowingmainevolutionsincapabilitiesareexpected inbothGeoStationaryOrbit(GSO)andNonGeoStationaryOrbit(NGSO)satellitesystems.

Performance:

HigherServicerateandthroughputs thanks tomultibeampayloadand largerantennafornarrowbeams tomaximizethefrequencyre-use

Increasedspectrumefficiency Higherenergyefficiency(W/km2 andW/kbps)

Features:

On board/ground processing to allow flexibility in bandwidth allocation across thesatellite coverage, in theutilizationof theallocated frequencies, innetwork topologieswiththesupportofstarand/ormeshwithorwithoutintersatellitelinks.

Theprogressiveconvergenceof traditionalbroadcastservicesandthe internetcalls foranewroleforSatCom.Thisprocessofconvergenceis,interalia,aboutmakingsureuserscanaccessamaximumofhighqualityaudio-visualcontentonanyoftheir deviceswhethertheyliveinurbanorruralareas.Intheselatter areas,whereFiberToTheHome(FTTH)isnottobeimplementedsoon, and so for technical and economic reason, hybrid broadband/broadcast networks areparticularly relevant. Satellites can proficiently be part of a hybrid network configuration,consistinginamixofbroadcastinfrastructuresandbroadbandinfrastructuresmanagedinsuchawaythatitbrings,seamlesslyandimmediately,convergedservicestoallend-usersintheEU.

1 FromBooz&Co,“Whysatellitesmatter”,http://www.esoa.net/news-info-30.htm

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4 Thesatelliteusecases

Thecontributionofthesatellitesolutionstothe5GKPIswillbefurtherexplainedinthissectionthroughtheidentificationof“satelliteusercases”as theareasinwhichsatellitecanplayapartin5G.Theassociated researchchallenges areidentified.

4.1 Usecases

Global coverage and dependability are andwill remain themain added value of space-basedcommunication services. Integrated in 5G network infrastructure, SatCom solutions are wellpositionedtotargetthe4maintypesofusecases identifiedinFigure2.

Figure2:satelliteusecasesin5G

4.1.1 Multimediadistribution

Description

Thanks to its natural broadcast capability over awide area, SatCom solutions can effectivelyconveyanyuserandcontroldata(e.g.popularmultimediacontent) – forliveTV(linear)orpushVOD - to an unlimited number of terminals or network nodes. SatCom is well positioned toentertaineverybody,anytime,fromwhateversource,withoutexceedingnetworkcapacities.

SatCom is typically the choice ofmeans to distribute efficiently similar content (video, audio,richmedia, files) toahighnumberof terminals insidethecoveragesimultaneously.Advancedterminal and user interfaces support in addition scheduling (time and/or frequency) withindefinedrepetitionintervalsallowsfordistributionofupdatesoftheaforementioneddatatypes,thus allowing the delivery ofmost popular content on demand to satisfy individual customerneeds.Accordingtothelatestforecasts,over90percentofallInternettrafficisexpectedtobevideoby2015.Thisstatistic single-handedlysummarisestheimportancethatvideotrafficwillhave in future networks. In order to offload the traffic, the simultaneous use of satellitebroadcastforlinearcontent(suchasvideo,includingUHDandHDvideo)combinedwiththeuse

Multimediadistribution

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Point to pointPoint to multi point

Ver

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Service continuity

M2M,Critical missions

Network control signalling off load

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ofbroadbandnetworksforthenon-linearcontent,isthemostcostandspectrumefficientmeansoftransmitting audio-visual linearservicesincludingHDTV,4K,both feedinglocaldistributionnetworkswithcontentanddeliveringthiscontentdirectlytoend-users. Inaddition,whenusedinahybridnetwork,thesatellitebroadcastcanfacilitatethedeliveryofnon-linearservicese.g.by ‘pushing’contenttoanequipment(belongingtotheoperator)atuser’spremises,inordertocontributetoimproveICToverallcostandspectrumefficiency. Thefigurebelowgivesaviewoftheultimatelyresultingconvergedmultimediadistributionnetwork.

Figure3:Convergedmultimediadistributionnetwork

Indeed,recentevolutionintheindustrysuggeststhatthedeliveryofmostactualcontent(video,audio, richmedia, files) to caches locatedat thenetworkedges orat theuser’spremise (bothundernetworkoperators’control) viabroadcastchannelsismoreandmorerequired.Themaindriverhereisthepressuretorelievethetraditionalbroadbandbackhaulmeanswithbroadcasttraffictobettersupportcontentspecifictoindividualcustomers.

Softwareupdatesconstituteagrowingandincreasinglycriticalcategoryofdatadistributionstoaplethoraofdevices,driveninpartbyresponsestosecurityconcernsand/oractualbreaches.Additional filteringby the embedded intelligenceof devices allows for the down selectiononspecificslikelocalisation,versioningorothercriteria.

Researchchallenges

The evolution of broadcast and broadband in the satellite industry and the upcoming hybridnetworksrequireconsiderableR&Deffortstosatisfychallengingfutureuserrequirements forperformance,cost,QoSandQoE. Themainchallengesare:

- Parallel access to both broadcast and broadband networks by the final users, in atransparentmanner

- Smartmanagementofbothbroadcastandbroadbandresources- Storageofcontentpusheddirectlytotheuser’spremisesunderthecontroloftheservice

provider.

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Indetailthisrequiressubstantialinsightsintotheinterfacesandrequirementsontheinterfacesbetween broadcast and broadband networks, their respective and aggregated networkmanagementandtheservicesdeliveredtothefuturecustomerexpectations.

More specifically, the evolution from the current, separated provisions of the linear TV(unidirectional) service and broadband (bidirectional) services to the development of a fullyintegrated (bidirectional) hybrid broadband-broadcast service provision, calls for a fewtechnological steps, each one raising specific issues. Already the format of the transport ofcontent from different sources (broadband / broadcast) has been configured into a unifiedformat-typicallyIP- compatiblewiththedistributioninthelocal/domesticnetworkandwiththeuseondifferentdevicesandscreens. Also anearlyandlimitedinteractionbetweennetworkoperators/content providers and final users (with issues regarding users’ preferences, thepopularityofcontentsandDRM) hasbeenmade.

Additionalstepsarenowneededasfollows;

To allow a full interaction between the final users and networkoperators/broadcasters:thebroadcasttechnologyisusedtopushcontentdirectlyatthe user’s premise. An additional function of a full hybrid broadcast/broadbandnetworkiscontentpushingdirectlyintoastorage(e.g.anin-homeNetworkAttachedStorage– NAS,oranequivalentdeviceinsidetheset-topboxorthehomegateway)which, although positioned at the user’s premises, remains however a networkterminationunit, controlledby thenetworkoperator or the content rights’ owner,andisnotuserequipment.

The remaining step for a fully integrated network requires native IP audio-visualcontent on the broadcast channel, thus replacing the MPEG Transport Streammultiplexing.All contentswill thenhave thesame format, regardlesswhether theyaredeliveredviathebroadbandorthebroadcastchannel.

Therequiredintelligenceforoptimaldatadistributionstrategiesarestillsubjectforsubstantialevolutiontomeettheeverincreasingcomplexities(versioning,localization,costs).

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4.1.2 Servicecontinuity

Description

With its regional (e.g.: single Geostationary satellite) or worldwide (e.g. constellation o ofgeostationary or non-geostationary satellites) coverage, SatCom solutions areessential to provide the 5G service everywhere including also in remote areas, onboard vessels, aircraft (In-flight services) and trains in a reliable manner. This isalready the casewith 3G given the costly deployment of cellular networks beyondurbanareasandisbeginningtobeimplementedin4Gaswell.

Satellite systems can contribute to extend the 5G service coverageeither providingbackhaulordirectaccessservice.

• On the one hand, satellites provide backhauling to interconnect a local areanetworkmadeofbasestationsoraccesspoints:

-The LANmay be deployed in an isolated area or on board aircraft, vessels oreventrains.Hence,thecellsofthelocalareanetworkmayeitherbeisolatedormayroamacrossothercells(e.g.Trains).

-Satellite can offload the terrestrial backhaul and/or offer backup in cases oftemporaryneedofextra-capacity

• Ontheotherhand,satellitecandeliver5Gserviceinadirectaccessprovidedthattheterminaldevicecanoperateinthe satellitenetworkandfrequencybands.

Researchchallenges

Toprovideaseamlessservicedeliverytothe5Gend-userswhiletheyroambetweenterrestrialandsatellitebackhauledcells,itisnecessaryto

• Ensurethatthenetworkprotocolscancopewithdifferentlatencies

• Supportverticalhand-oversbetweenthenetworkstoenableterminalstoalwayspick-upthebestaccesstechnologyavailable

• Defineschemes thatmitigatepossible interference issuesbetweensatellite andterrestrialnetworks(millimetrewaveaswellasSband).

• AddressSLAagreementissuesbetweenterrestrialandsatelliteserviceproviders

• Investigatepossiblesatelliteandterrestrialnetworkdualmodeintegrationin5Gdevices.

• Applicationdependentconnectionselection (intheaccesspoint).

• Businessmodelsfortheaccesspoints(private,shared)

Lowcost,lowenergyconsumingaccesspoints(SatCombackhaul,mobileconnections)

4.1.3 MachinetoMachine

Description

Theinclusionofbillionsofsensorsandactuators,commonlyreferredasInternetofThings(IoT),all transmitting lowdate ratesandbeingscatteredoverwideandremoteareasmakes itwell

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suited to data collection and control via satellite. In particular, monitoring/surveillance ofvarious assets (vehicles, homes, machines, etc.) in remote locations, asset tracking (e.g.container)andtransferdataand/orconfigurationtoagroupofwidespreadrecipientsrequiressatellitesystemstoensureservicecontinuity.

Researchchallenges

VariousresearchchallengesareassociatedtotheaforementionedM2Musecasesasdescribedbelow.

Protocols for Battery PoweredM2MSatellite Terminals. In contrast to the terrestrialM2Mwherebatterypoweredterminalsarestartingtoofferseveralyearsofbatterylifeyet, satelliteM2Mmight need to be reconsidered. Indeed, in contrast to the terrestrial Internet of Things(IoT) transceiverswhere the energy consumption is limitedand itsMACprotocolshavebeenthoroughly re-examined recently, the satellite ones need to be re-considered in order to faceextremelydemandingbatterylifeconstraints.Asaresult,abatterypoweredM2Msystemwouldbeavailable.

EnergyEfficientWaveformsandhardware.Despite so far thehardwaresatellitedesignhasbeenattendingotherreasonsthantheenergyefficient,itisbecomingurgenttore-thinkthePHYlayerincasetheenergyconstraintsareveryhigh.Thisstudymustbeaccompaniedbyacarefullyinvestigationonthehardwaredesignsinceitencompassesthemajorenergyimpact.

SecurityandIntegrity.Security isofparamount importanceinM2M/satellitecommunication,ensuringthatthewholesystemoperatesinasmoothlyandsafewaywithoutanykindofattackand/orintrusion. Thisisofgreatimportanceinthoseattacksdevotedtoforcetheterminalstowasteenergy.

UnifiedRoutingApproach. Duetoits ‘lossy’nature,IoTnetworkshadtoredefinetheroutingprotocolsinordertoaccomplishthedifferenttrafficandnetworkfeaturesofM2Mnetworks.Incase the satellite component is present in the IoT scenario, those protocols need also the berevisitedinordertoincorporatethesatellitenaturewherethedelayplaysacentralrole.

ServiceDifferentiation.M2Mservicesandapplicationshavedifferentrequirementsintermsofdatarate, latency,security,etc. InthatrespecttheM2M/satellitecommunicationsystem,mustbe able to support end-to-end Quality of Service (QoS). For example an alarm notification,requires an immediately and real-time communicationwith the satellite,while other serviceswhichperformperiodicreportingactivitiesrequireonlyreliablecommunication.

4.1.4 NetworkcontrolSignallingoffload

Description

Thearchitectureof5Gisbasedonalargenumberofsmallcells—densification.Oneofthemajorproblemswith this architecture is the increase in the amount of signalling neededwhich canreducethedatacapacityconsiderably—ithasbeensuggestedbyasmuchas25%.Inadditiontothis thebase station signalling contributes to theoverall energyusagewithin the systemandpreventsachievementoftheenergyreductionKPI’sfor5G.Inordertoaddressthistheconceptof splitting the control (C) plane from theData (U) plane has been proposed such that the Cplanecanbedeliveredviaanoverlaymacrocell.InthisarchitecturethebasestationjustdeliverdataontheUplanesavingcapacityandenergy.Theproposalhereistomakethemacrocellasatellitecellsothattheterrestrialspectrumcanbesaved.

Researchchallenges

ThechallengehereistoexaminethelatencyissueswithvarioussatellitearchitecturesincludingGEO and Non-GEO on the C plane distribution over the satellite. As a start the current 4Gnetworkingmodelcanbetakenandmodelledwithcellularandsatelliteoverlaycellsto assessthe viability and the reduction in signalling capacity and energy that results. As the 5G

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networking structure develops such an integrated satellite-cellular architecture can be testedandfeedbacktothe5Gstandardsmade.

4.1.5 Critical telecommissions

Description

The combination of dependability and coverage are key assets to deploy or recover services(resilience).Hencesatellitesolutions(communicationandnavigation)arekeytoprovidepublicsafety or emergency communications in case ofman-made or natural disasters or tomonitorandcontrolcriticalinfrastructures(utilities,transport oreventhetelecomnetwork).

In caseof a crisis, commercialnetworksmayoftenexperience congestionor even failure andhence service needs to be recovered. Service continuity can be ensured thanks to theredundancy(coldorhot)ofcriticalnetworklinks using satellitecommunications asaback-up.

Inadditiontolegacycommercialnetworks(2Gand3G),civilprotectionorganisationsmakeuseof dedicatednarrowbandnetworks(e.g.TETRA)operatinginspecificfrequencybands.Soon,thededicatednetworks willbeupgradedtoofferbroadbandfeaturesusing the 4G/LTE technology.As per 5G, its flexibility to support M2M as well as very high speed broadband in variousfrequency band makes it suitable to support also advanced public safety communicationssharing the same network infrastructure resources with the other commercial applications.Satellite solutions based on light weight nomadic terminals with high speed broadbandcapabilitieswillbenecessarytosupport5Gservicesandimproveresponsetimetocrisis.

Researchchallenges

Toprovideseamless, securedanddependablehighspeedbroadbandand/ormobileservicesforcriticaltelecommissions inacombiningsatellite,cellularandad-hocnetworks.

To ensure maximum transparent interoperability among the various stakeholders of theemergency/criticalsituation.

5 Satcomresearchtopicsin5G.

5.1 Thekeyareasthatsatellitescancontributein5G

Fromtheusecaseswecanextractthat thekeyareasforsatelliteasfollows;

Extendingthecoverageof5Gnetworks. DeliveringmultimediaclosertotheedgetoimprovelatencyandQoE. Off-loadingtheterrestrialnetworke.g.byusingsatellitebackhaulandbytakingcontrol

trafficviasatellite. Providingresiliencebyintegratingsatellitewithterrestrial. Integratingvirtualisationviasoftwaredefinednetworking. Allowingimprovedutilisationofthespectrumbetweenthesystems.

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5.2 Keyresearchtopics:

5.2.1 Serviceprovision:

Satelliteswillplayanimportantroleintheextensionof5Gcellularnetworkstosea,airandremotelandareasthatarenotcoveredbythesmallcellnetworks.Withmanymorepeopleexpectingtohavethesamecoveragewhentravelling(oncruiseliners,passengeraircraft, high speed trains and inholidayvillas) it is key that satellite allows seamlessextensionof5Gservices.

IoTcoveragetowideareasinvolvingsensorsandM2Mconnectionsareidealservicestomakeuseof satellitewidearea coverage. The challenge is todesignefficient lowdataratecommunicationsinlargenumbersviathesatellite.

TransportservicesincludingV2Vareagainideal forsatellitewithitswidecoverage.Inthesafetymarketallnewvehiclesarelikelytobemandatedtoincludesafetypackagesand given the need for ubiquitous coverage systems that follow on from the EUSAFETRIPsystemdemonstration willplayakeyrole.

Localisation and positioning is key to many different 5G services. The integration ofcellularandsatellitepositioningsystemsisakeychallengetoenablingthisvastrangeofservices.

Satellitesarealreadyusedforearthresourcedatawhichisinitselfusedasaninputtomanynewservices.Couplingthiswithintegratedsatelliteandcellularcommunicationswillprovideapowerfulnewfusionenablingtheinnovationofservices.

Security services require high resilience and thus the use of satellite together withcellulardeliverywillhelpprovidetheseveralninesavailabilityrequired.Mostcountrieshave fall backdisaster andemergencynetworkswhich canbenefit froman integratedsatelliteandcellularapproach.ThereisincreaseduseofsurveillanceusingUAV’sandthenecessityforrealtimehighdefinitionvideowhichisbestdeliveredbysatellite.

Satelliteshavetraditionallybeenused forbroadcastpurposesbutaswemove intothedomainofCDN’s the ability of satellites todownloadhighdata that canbe cached foronwarddeliverybecomesanattractivefeature.Theinterplaywithnew(inter)networkarchitectures, such as CDN is important to consider for SatCom/ cellular integration.Pervasive andtargeted cachingandnamingofinformationandcontenttransferredoverthe networks would more easily allow the inclusion of SatCom into an integratedSatellite-Terrestrial network by exploiting the broadcast/multicast and broadbandcapabilitiesandmaskingthelongerpropagationdelay.Thisagainreducesthedemandson the terrestrialnetwork. This fitswellwith the 5G aim topush large content to theedgesandclosetotheuserstoimprovelatency.Thiscanbedoneinatargetedmannerforregionsorforindividualcells.

QoE isbecoming thebyword for serviceprovision andamajordifferentiator, but it islittleunderstoodat themoment. It isclear thatpeakandaveragebitratesarenot thedeterminingfactorbutsustainablebitratelinksmoreto the QoE. Intelligentdeliveryofservicesusingthesystemsthatbestsuits theQoE to theuser isanotherareainwhichsatellitecanplayapart.

5.2.2 SoftwareDefinedNetworksandVirtualisation:

Therewillbeaparadigmshiftinnetworkdesigntoallownetworks toreacttothedemandsofthe users wherever they are—‘demand attentive networks’. This will be brought about byvirtualisation in the network and software that allows the dynamic reconfiguration of thenetworktogiveuserstheperceptionofinfinitecapacityfortheirapplication.Theextensionofcurrenttrendsinvirtualisationand“softwarisation”-especiallyinthedomainsofSDNandNFV-tosatelliteinfrastructuresisindeedaveryattractiveperspectiveforthesatcomcommunity.Byexploiting SDN/NFV enablers, satellite equipment vendors developing specialised networkingequipmentforspecificuse(onboardorground),havethepotentialto“open”theirplatformsby

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making them programmable and reconfigurable. As for satellite operators, the virtualisationparadigm is expected to be a very attractive revenue source, offering them the ability tomonetizeontheirnetworkbyofferingnewservicesandbychargingcustomersaccordingtotheactualusageofin-networkresources.TheapplicationofNFVand“CloudRAN”aspectstosatcompaves theway towards the full virtualisation of satellite head-ends, gateways/hubs and evensatelliteterminals,thusentirelytransformingthesatelliteinfrastructure,enablingnovelservicesand optimising resource usage. In this context, several enhancements/adaptations of currentSDN/NFVtechnologies(e.g.extensionsoftheOpenflowprotocol) areenvisaged,inordertobefullyapplicabletothesatcomdomainandexploitsatellite-specificcapabilities.

Virtualisation is consideredas thekey enabler for the efficient integrationof the satellite andterrestrial domains. Via the unified management of the virtualised satellite and terrestrialinfrastructures, fully integrated end-to-end network “slices” can be provided, integratingheterogeneous segments in a seamless and federated way. This will enable ‘opportunisticintegration’ofthesatelliteandterrestrialresources.

5.2.3 ConnectivityandNetworks:

Theintegrationofsatelliteandterrestrialcanbeusedtoextendthe5Gnetworktoubiquitouscoverage.Forexampletosea—cruiselinersandyachts,topassengeraircraft,trainsandeventoremotelocationssuchasholidayvillas.Ineachofthesedomains userswillexpecttoaccesstheirhome 5G services. This can be achieved in a variety of network architectures facilitated bysatellite’s wide coverage. A simple example is via backhauling but this can be done in anintelligentmannerby routing trafficeitherover thesatelliteor terrestriallydependingon thecontentandtherequiredQoE.Non-GEOsatelliteconstellationsarecurrentlybeingresearchedtoachieve optimal networking and latency. Intelligent gateways can be designed in a demandattentivemanner to maximise the total resources available and multipath TCP and networkcodingcanbecombinedtofacilitatesuchschemes.Suchsatellitelinksarenowbeingresearchedin the optical area which provides massive increase in capacity and with smart diversityschemestheavailabilitycanbeprovided.

The integrationofnetworkstandards isseentobecrucial in thesearchitectures. Inparticularhow the satellite gateway interconnects into the 5G network interfaces. There are variousscenariosofinterconnectionbetweenthenetworkentities thatseparatethecontrolplanefromthedataplanethatwilldeterminetheperformanceandthesignallingloadonthenetworksthatneedstobeminimised.

One of the major contributions that satellite can make to 5G is to off-load traffic from theterrestrialnetworksandinparticularforthevideobasedtrafficwhichisthelargestcontributorto the spectrumdemands.This canbeachievedby traffic classificationand intelligent routingandwillthusreducethedemandsontheterrestrialspectrum.

Integratedlocalisationschemesarekeyenablerstomanynewservicesin5G.Thenotionofper-user integrated location and service management in cellular/satellite systems should beinvestigated either to help in spectrum sharing or to improve trunking systems. A Per-userservice proxy can be created to serve as a gateway between the user and all client-serverapplicationsengagedbytheuser.Theaimisthatwhenevertheuser'slocationdatabasemovesduringalocationhandoff,aservicehandoffalsoensues collocationoftheserviceproxywiththelocationdatabase.Thisallowstheproxytoknowthelocationofthemobileuser toreducethenetworkcommunicationcostforservicedelivery.Differentuserswithvastlydifferentmobilityandservicepatternscanadoptdifferentintegratedlocationandservicemanagementmethodstooptimizesystemperformance.

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5.2.4 Airinterface andSpectrum:

The5Gairinterfacehasthechallengeofincorporatingarangeofdifferenttraffictypesfrom thehighratevideodowntothelowrateIoTapplicationsandservingapplicationswitharangeoflatency requirements. We see that the integration of satellite and cellular 5G is essential toextractthecombinedbenefitsofbothsectors.Inthisrespectweneedtoadoptasfaraspossiblea common AI. The drivers in the satellite channel are however different than those in thecellular—multipath is not so important but the channel is non-linear and suffers frommorelatencyinhibitingadaptation—dependingonthesatelliteorbit.ThereismuchtobegainedfromanintegratedterminalwhichusesasmuchcommonalityaspossiblewithterrestrialviaideasofimplementingsoftwareMACforexample.Thisneedstobecoupledtotheenergyreductionthatcan be achieved in the terminal design. Multi-polarization MIMO as a scheme that requiresreduced channel state information is suitable for satellite and context aware multi-userdetection, either centralized or decentralized plus other forms of interference mitigation.ReceiversforburstycommunicationsisanareaofresearchthatwillbenefittheroleofsatellitesinIoT.Multicarrierschemessuchasfilterbanksystemswithappropriatemodulationsthatofferoptimal spectral efficiency and frequency granularity are being investigated in terrestrialwirelessbutalsohavecommonalityinsatellitesystems.

Spectrum isan issue forbothmobileand satellite systems. Asmobile systemsmove into themillimetrewave bands, consideration needs to be given to co-existence of both sectors. Oneexampleof this is the27.0 to29.5GHzband. In someregionsof theworldmobile isprimaryfrom27.0to29.5GHzbutcurrentlynotactive,whereasbroadbandsatellitesystemsareusingtheband foruplinks. Ifsatelliteuseof thisbandbecomes impossible(as itwillbe if therearesubstantialnumbersofmobileterminals)thebandbecomesfragmentedanduneconomical forsatellite.Therearesome opportunities toachieveawin-winsituation,possiblyusingcognitivetechniquessothatbothsectorscanachievemorespectrumusage andalsobykeepingmobile’smm-wave usages above 31 GHz.. The use of frequency division duplex, already standard forsatellite,isanotherareainwhichaspectrumgaincouldpossiblybeachieved.

6 TechnologyRoadmap:

Apossible technology roadmap canbe seen inTable 1. This is divided into three broad timeperiods—upto2016,between2016to2020and2020andbeyond.Thefirstperiodisfocusedon studies aimed at solutions to the challenges. The second period is focused on turning theresultsofthesestudiesintostandardsfor5Gandsomeearlydemonstrations.Thefinalperiodisdevotedtopre-operationaldemonstrationsandservicedelivery.Keyareasinthestudiesare;

• Integratedarchitectures toincreasecoverage anddelivermultimediatotheedge.

• Compatibleairinterfaces includingadvancedsignalprocessing

• Integratednetworks usingSDN foroffloading

• Spectrum enhancementsin themillimeterbands

• Newsatellitearchitecturestoimprovebackhauling

Inthestandardsphasethereisaclearneedtoworktogetherwiththemobile5Ggroupsintheairinterfaceandnetworkingareasratherthanaddressingseparatestandardsbodies.Inthisandthefollowonstageitisimportanttoparticipateincommontestbedsthatintegratesatelliteandmobile.

Timeline/Technolo 2016-studies 2016-2020-standards +2020-

14

gy Demo/operation

Integration 5G over satellite

Backhaul, SDN,

intelligent

routing

5G satellite core

network

interface

Multimedia to

the edge studies

Sat converged

network.

ETSI/DVB/5GPPP

Early lab demo’s

Fully

integrated

operation

IoT Demo

Air interface Multi carrier on

satellite study

Latency/synch

Cellular

integration

Incorporate

satellite into 5G

standard.

Lab demo’s

IoT early Demo

Demo of fully

integrated AI

IoT Demo

Spectrum Co existence

mechanisms

Evaluate gains

Ka/Q/V/E

Lab Demo’s

Inc in standards

Regulatory

acceptance

Franchised

data bases

Operational

Resilience Architectural

studies

Security issues

Hand over issues

Lab Demo’s

Inc in standards

Equipment

prototypes

5G Demo

with sat and

cellular

operations

localisation simulation

sat+cellular

Lab Demo’s

Demos’ with

services

Inc in standards

5G network

demo’s

Services

operational

Satellites Orbit studies for

future systems

Frequency band

Specify 5G sat

ESA ITT’s for key

elements

Satellite

Demo launch

and early

tests

15

studies

MB Antennas

Interference/RA

In Orbit tests of

key elements

Operational

with IoT

Ground

segment/terminal

s

Feeder diversity

studies

GBBF/OBBF

optimisation

Integrated

terminal studies

Energy

minimisation

Hand overs

Demo integrated

networking

Terminal

prototypes

IoT terminals

Demo’s on

5G satellite

Service

demo’s

IoT operation

Table1.Roadmapforsatelliteresearchanddevelopmenttowards5G

7 ContributionofSatellitesystemstothe5GPPKPIs

7.1 PerformanceKPIs

KPI#1 - Providing 1000 times higher wireless area capacity and more varied servicecapabilitiescomparedto2010.

• Suchcapacityincreaseputshighconstraintsonthedimensioningofthewirelesssystematboththeradiointerfacetotheend-userdeviceaswellasthefrontandbackhaulinterfaces.Introducing satellite broadcast/multicast resources to network edge (data distribution) willenable tooff loadpartof the traffic tooptimise the infrastructuredimensioning.Furthermore,high speed broadband satellite systems are needed for backhauling to extend the reliabledeliveryof5Gservicestopublictransportationsincludingaircrafts,vesselsaswellastrainsandbuses.

KPI#2 - Reducingtheaverageservicecreationtimecyclefrom90hoursto90minutes(ascomparedtotheequivalenttimecyclein2010).

• Aseamlessintegrationofsatelliteaccessnetworksin5G,willresultinaunifiedservicedeliveryandalignedservicecreationtime.

KPI#3 - Verydensedeploymentstoconnectover7trillionwirelessdevicesservingover7billionpeople.

• Part of theM2Mdevices/trafficwill beoff loaded to satellite systems to ensureglobalservice continuity. In addition, general control plane signalling can be off loaded to satellitesystemstoincreasethenetworkcapacityfordatatransmission.

KPI#4 - Secure, reliable and dependable Internet with zero perceived downtime forservicesprovision.

• Thankstoitsdependabilityandwideareacoveragecharacteristicssatellitesystemswillconstitute the necessary overlay network to enable a high network resiliency and to supportrapidservicedeployment/recovery.

16

7.2 SocietalKPIs

KPI#5- EnablingadvancedUsercontrolledprivacy

• Thanks to secure communication capabilities, the satellite can contribute to the usercontrolledprivacywhichisimportantforapplicationssuchaseHealth.

KPI#6- Reductionofenergyconsumptionperserviceupto90%(ascomparedto2010)

• Withappropriateandreasonabledevelopmentsatterminallevel,broadcastinguserdatafromasolarpoweredsatelliteplatformoverawidearea (datadistribution)willconstituteanenergyefficientdeliveryandhencewill contribute tooptimise theenergyconsumption in thenetwork.

KPI#7 -European availability of a competitive industrial offer for 5G systems andtechnologies

• 5GPPP constitutes a unique framework for European Satellite system researchstakeholders todevelop leadershipwith innovative technologies andproducts enabling smartintegrationofsatellitesolutionsin5Gthatcanbecommercialisedworldwideandespecially inemerging countries where coverage and dependability issues are even more acute than inEurope.

KPI#8 - New economically viable services of high societal value likeU-HDTV andM2Mapplications

• Satellitesystemsareessentialinthe5Gnetworktoenableacosteffective UHDTVservicedelivery (data distribution), the global service continuity for end-users as well as M2Mapplication, the network resiliency as well as rapid service deployment for critical missionssupport(e.g.PublicProtectionDisasterRelief).Lastbut notleasttheywillcontributetoprovidee-governmentande-healthapplicationsatpan-Europeanlevel.

Establishmentandavailabilityof5GskillsdevelopmentcurriculainpartnershipwiththeEIT

• Theintegrationofsatellitesystemsin5G,willfoster theneedforcommonexpertiseandfacilitatejobmobilityacrosssatelliteandterrestrialindustry.

References:

[1] Thompson J. et al ‘5G Wireless CommunicationsSystems—properties and challenges’IEEECommsMagazine,Feb2014.

[2] CostIC1004Whitepaperonscientificchallengestowards5GMobileCommunications—ncardona@iteam.upv.es

[3] ‘Scenarios, requirements and KPI’s for 5G mobile and wireless systems’ ICT-317669-METIS/D1.1.April2013.www.metis2020.com/docum,ents/deliverables

[4] Horizon2020-Advanced 5G Networks Infrastructure for future Internet PPP—www.Net!works.eu

[5] ECH20205GInfrastructurePPP—PrestructuringmodelRTD&INNOstrands—www.5g-ppp.eu

17

AppendixA:Mappingintothe5GPPP2014/15call.

Researchtopics identification

Inthissectionwetaketheusecasesandtheresearchtopicsaddressedinthepaperandattempttomapthemintothepre-structuredprojectsaddressedinthe5GPPPAssociationpaper.

Servicecontinuity

Backhaulingservice

AirinterfacecommonbuildingblocksbetweenFSandFSS(P2) Enablersfor improvedspectrumefficiencyofSatellitenetworkinexclusiveandshared

bandcontext(e.g.millimetre wavebands) =>P4 Commonhardware/softwarebuildingblocks (P5) Flexibletransport/networkprotocoltocopealso withextendedlatency =>P7 Jointsatellite-terrestrialbackhaulresourcemanagement=>P7 Verticalsatellite/terrestrialnetworkhand-over =>P9 QoE:Latencymitigationwithsmartcachingscheme =>P10 SatComintegrationwith terrestrialnetworkatnetworkmanagement,serviceleveland

security(P10,11,12and13)

Directaccessservice

Airinterfaceharmonisation(P2)(multi-bearerincludingsatellite) Enablersfor improvedspectrumefficiencyof Satellitenetwork inexclusiveandshared

spectrum context =>P2 Integrationofsatelliteaccessnetwork withcorenetwork(P8) Integrationof satelliteasWirelessaccessnetwork in thenewRANarchitecture for5G

(P6) Definitionofnewcorenetworkwithacommonunifiedcontrolplane:intra-technology,

inter/intra-domain(P8) Contextmanagement tooptimize resources andallowhandoverbetween technologies

(P8,P9) Verticalhand-over(P8,P9) Seamless service andnetworkmanagement integrationwith terrestrial network (P10,

11,12and13) Networkconvergence(P6,P8,P9,P10,P12)

Multimediadistribution

Efficientprotocolsandairinterfaceforallkindsofdatadistributionspanningtherangeof small to largest data elements (for instance, SMS’s on the small side to Ultra HD-moviesandverylargedatabasesonthelargeside) =>P2,P5,P6,P7,P16

Optimal data distributions strategies utilising broadcast or highly asymmetric datachannels=>P8

Cachingplacementstrategy,algorithmsandprotocolsforanoptimisedQoE=>P8,P9 Efficientrecoveryofinterruptedcachefills=>P9 Integratednetworkmanagement=>P11,P12 Content rightsmanagement of distributeddata as it propagates through networks =>

P13,P14,andP15 Authentication(viasatellite)thatcacheddataisthelatest,andisnotspoofed=>P13

18

Accordingtothedifferenttechnologicalstepslistedabove,anetworkelement(suchasaHome Gateway) (P5)which enables the reception of broadcast / broadband contentbothina:

o transparentwayforthefinaluser;o smart(softwaredefined)wayforthenetworkoperator;o Pluspush-VOD

Full FrequencyReuseMultibeamHTSSystems for jointBroadband/Broadcast services=>P2

Finally, even though broadcast is, by definition, more open than individual point-to-pointcommunications, network security and integrity are still important. Hence 5G InfrastructurePPPPre-structuringmodelprojectP13mustalsoincludemultimediadistribution.

M2M

Optimized assignment of resources (e.g., appropriate spectrum bands, not conflictingwith incumbents) by taking into account combined usage of terrestrial and satellitenetworks => P9

Enablersfor improvedspectrumefficiencyof Satellitenetwork inexclusiveandsharedspectrum context=>P2

Improvement of end-to-end QoS/QoE and latency (e.g., serving latency-sensitiveapplication) including satellite segment by taking into account energy and costconstraints => P9

Commonandgenericmodulesforaccessagnosticnetworkandservicemanagement =>P9,P10,P11,P12

Integratedsystemandgatewaydesign=>P1,P3 Embeddedchipsetswithintegratedcellular/satellitemodules=>P5 Smallomnidirectionalantennas=>P2

NetworkcontrolSignalling offload

Designamulti-RATsystemthatefficientlyintegrateslegacyand5Gairinterfaces-controlplaneanduserplanedesignfornovel5Gcomponents(P1)

Energyefficiencyfornetworkdesign(P2) Designsignalling,protocolsandMMacrossmultipoint/bandlayernetworks(P6) Seamlessintegrationofheterogeneouswirelessandsatellitesystems (P7) Defineaconvergedandflexiblecontrolplaneforheterogeneousaccessandoptimisation

ofserviceanddata(P8) Conceive and design novel enabling technologies for a unified control and data plane

structure(P9)

Criticaltelecommissions

Toprovideseamlessandreliableservicesforcriticalmissions,itisnecessarytodefine:

Integrated system design (comprising satellite and terrestrial networks) includinghandoverprocedures andrequiredairinterfacesfortheprofessionalservices=>P1,P2,P3

Enablersfor improvedspectrumefficiencyofSatellitenetwork inexclusiveandsharedspectrum context =>P2

Satellitearchitecturesforon-board-processingtosupportmeshednetworksforhub-lesscommunication=>P1,P6

19

Satellite/terrestrialterminalarchitecturesforseamlessserviceprovision=>P5 Handover protocols for professional mobile radio (PMR), satellites and alternative

terrestrialnetworks=>P6 Intra-system frequency coordinationmethodologies andprocedures incl. the influence

on the terminal architecture; definition of service prioritisation (of professional andcommercialservices)ismandatory=>P8,P11

Mobility,securityandQoS(P8)

20

Researchtopics mappingtothe5GPPPpre-structuringmodel2

TheidentifiedSatComresearchtopicshavetobe incorporatedinallof thebelowprojectssothatthe5Gcanbenefits fromSatComaddedvalue resulting inenhancedKPIs. If this isnotpossible,projectproposalsbeyond theprestructuredmodelwillhave tobeconsidered toaddresstheresearchtopics identifiedinthispaper.

Px Projectstrandname SatComusecasesandexternalconstraints

Globalservicecontinuity

MultimediaDistribution

M2M Nwkcontrol

signallingoffload

Criticaltelecommissions

P1 5GWirelessSystemDesign X X X

P2 AirInterfaceandMulti-Antenna,Multi-ServiceAirInterfacebelowxxGHz X X X X X

P3 5G-MTC (Machine Type Communications) for Consumers and ProfessionalCommunications

X X

P4 NewSpectrumandmm-WaveAirInterfaceforAccess,BackhaulandFronthaul X X

P5 EfficientHardware/SoftwareandPlatformsfor5GNetworkElementsandDevices X X X X

P6 NovelRadioSystemArchitecture X X X X

P7 BackhaulandFronthaulIntegration X X X

P8 Holistic5GNetworkArchitecture X X X X

P9 EnablingTechnologiesforUnifiedControlofConverged5GSystem X X X X

P10 5GServicesE2EBrokeringandDelivery X X X

P11 CognitiveNetworkManagement X X X

P12 ServiceLevelManagement&MetricsforQoS&QoE X X X

P13 5GNetworkSecurityandIntegrity X X

P14 VirtualNetworkPlatform X

P15 ServiceProgrammingandOrchestration X

P16 Multi-DomainSWNetworks X

2 ECH20205GInfrastructurePPPPre-structuringModelRTD&INNOStrands(Version2.0),Recommendationby5GInfrastructureAssociation,May2014