View
216
Download
0
Category
Preview:
Citation preview
8/13/2019 2008 12 Rysavy Spectrum Demand
1/24
MobileBroadband
SpectrumDemand
December 2008
Copyright2008RysavyResearch,LLC.Allrightsreserved.
http://www.rysavy.com
8/13/2019 2008 12 Rysavy Spectrum Demand
2/24
2MobileBroadbandSpectrumDemand
Table of Contents
EXECUTIVE SUMMARY............................................................................................ 3
FORWARD BY PROFESSOR WILLIAM WEBB............................................................ 4
1 INTRODUCTION............................................................................................... 5
2 MARKET FACTORS............................................................................................ 5
2.1 CRITICAL MASS-MARKET ADOPTION ..................................................................... 6
2.2 USE OF HIGH-BANDWIDTH DATA APPLICATIONS........................................................ 6
2.3 TRUE MOBILE BROADBAND USER EXPERIENCE .......................................................... 7
2.4 SMARTPHONE EFFECT....................................................................................... 8
2.5 APPLICATION INNOVATION EFFECT........................................................................ 9
2.6 INNOVATIVE PRICING......................................................................................10
2.7 FIXED-MOBILE SUBSTITUTION AND FIXED-MOBILE CONVERGENCE..................................10
3 QUANTITATIVE ANALYSIS............................................................................. 11
3.1
GROWTH IN IPTRAFFIC ...................................................................................11
3.2 CURRENT MOBILE DATA GROWTH .......................................................................11
3.3 PROJECTED MOBILE DATA GROWTH .....................................................................12
3.4 CAPACITY OF WIRELESS NETWORKS RELATIVE TO APPLICATION DEMAND ..........................13
3.5 MONTHLY USAGE ANALYSIS ..............................................................................16
3.6 CAPACITY OF WIRELESS NETWORKS RELATIVE TO AVERAGE SUBSCRIBER USAGE .................18
4 OTHER SPECTRUM CONSIDERATIONS............................................................ 20
4.1 NEEDS OF ADVANCED TECHNOLOGY .....................................................................20
4.2 CONSUMER EXPECTATIONS ...............................................................................21
4.3 NEW WIRELESS ARCHITECTURES AND SPECTRUM IMPLICATIONS ....................................22
4.4 SPECTRUM ANALYSIS BY OTHER ORGANIZATIONS .....................................................23
5
CONCLUSION................................................................................................. 24
Rysavy Research provides this document and the information contained herein to you for informational
purposes only. Rysavy Research provides this information solely on the basis that you will take responsibility
for making your own assessments of the information.
Although Rysavy Research has exercised reasonable care in providing this information to you, Rysavy
Research does not warrant that the information is error-free. Rysavy Research disclaims and, in no event,
shall be liable for any losses or damages of any kind, whether direct, indirect, incidental, consequential, or
punitive arising out of or in any way related to the use of the information.
8/13/2019 2008 12 Rysavy Spectrum Demand
3/24
3MobileBroadbandSpectrumDemand
ExecutiveSummaryTheconvergenceof the Internetandmobilecomputing isaccelerating theconsumptionof licensed spectrum. For
example,watchingaYouTubevideoonamobilephoneorwirelessenabled laptopconsumesalmostonehundred
timesthedatabandwidthofamobilevoicecall. Andwhereasamobilevoicecall typicallyconsumes612kbps,
enhancedhighspeedmobileInternetaccessconsumesupto5Mbpsontodaysdeployednetworks.Thus,withinthe
nextdecade,
licensing
significant
amounts
of
additional
spectrum
will
be
imperative
ifthe
United
States
wants
its
mobileoperatorstocontinueexpandingandupgradingthecountryswirelessbroadbandnetworks.
OtherorganizationshavestudiedthespectrumneedsofemergingwirelessnetworksindepthincludinganITUreport
thatprojectsatotalnationalspectrum requirementofasmuchas840MHzby2010,1300MHzby2015and1720
MHzbytheyear2020.Theseamountsfarexceedcurrentlyavailablespectrum.UnliketheITUReport,thisreportdoes
notidentifyhowmuchlicensedspectrumwillbeneeded,norwhatbandsareoptimal,toensureU.S.mobilenetworks
stay ahead ofexplodingconsumer demand. Rather, this report explains the dynamicsof the U.S.mobile industry,
including the trends behind the growth of the mobile broadband market, and quantifies the amount of data and
spectrumconsumedbynewdevicesandapplications.
Whereas previous wireless networks offered a somewhat sluggish data experience, third generation networks are
providingusers
atrue
broadband
experience.
Faster
speeds,
as
made
available
with
3G
and
other
emerging
wireless
technologies,translatedirectlytousersatisfaction.Currentusagetrendsconfirmthisreality.Ericsson,a leading3G
infrastructurevendor,indicatesdatatrafficisalreadythreetimesthevoicetrafficonsomeUMTSnetworkstheyhave
measuredwithinthelasttwelvemonths.Aleadingnationalwirelessbroadbandproviderpredictsthatby2018,3G/4G
mobiledatatrafficwillexpandbyafactorof250 (conservativeestimate)to600 (aggressiveestimate). Incontrast,
mobilevoicetrafficisexpectedtoonlytripleinthatsameperiod.
Thecapacityofawirelessnetwork (andthereforethenetworksabilitytosupportwirelessbroadbandservicesand
applications)inanygivenlocationdependson spectralefficiency,aswellastheamountofspectrumtheoperatorhas
available. Mobile network operators are currently implementing or considering various mechanisms to maximize
capacitybymanagingbandwidthconsumptionintheabsenceofaccesstomorelicensedspectrum. Whileengineering
greaterspectral
efficiency
and
building
more
cell
sites
will
increase
capacity,
alone
they
are
unlikely
to
address
the
expectedmagnitudeofthedemand. Longterm,morespectrumisneededtoenableU.S.mobilenetworkoperatorsto
keeppacewithconsumerdemandformoreandfastermobilebroadband.
Inaddition tohelpingprovidersmatchdemand,makingmorecommercial licensedspectrumavailablewill facilitate
thedeployment ofnewwireless technologies thatbenefit from deploymentacrosswide radiochannels.However,
allocatingwiderchannelsinexisting,licensedspectrumbandstoaccommodatenewtechnologies,whilecontinuingto
supportlegacytechnologies,istechnicallyandoperationallydifficult. Thisisbecauseoperatorstypicallydonothave
largeblocksofunusedspectrumtheycanaccessacrosstheircoverageareas.Thus,deploymentofnewtechnologies
willbegreatlysimplifiedifdonethroughnew,licensedbands.Asithasthroughoutthehistoryofthewirelessindustry,
thisadditionaldeploymentandexpansionofnetworkcapabilitieswillsupportarobustcycleofinnovation.Justasthe
Internethasprovidedfertilegroundfornewapplications,itisinevitablethatamobileInternetwillspurcomparable,if
notgreater innovation.Forexample,thereareover10,000applications forthe iPhone,eventhoughthedeveloper
toolsweremadeavailablejustthisyear.
Mobilebroadbandnetworkscanonlymeetconsumerdemandsformoreandfastermobilebroadbandthroughaccess
tomorelicensedspectrum,anddeploymentofmoreinfrastructure.Giventhelongtimeframesinvolvedingoingfrom
planningtoauctiontodeployment,planningfornewlicensedspectrumshouldbeginassoonaspossible.
8/13/2019 2008 12 Rysavy Spectrum Demand
4/24
4MobileBroadbandSpectrumDemand
ForwardbyProfessorWilliamWebbProfessorWilliamWebb,FIEEE
HeadofResearchandDevelopment,Ofcom
London,England
Author,"WirelessCommunications:TheFuture"and"EssentialsofModernSpectrumManagement"
Itappearsthatthetimehasfinallycomeforwirelessdataservices.Aftermanyyearsofhopesandfalsestarts,theuse
of cellulardata cards for laptops and inbuilt data capabilities in smart phones is growing rapidly. This in turn is
dramatically increasingthetrafficflowacrosswirelessnetworks,bothcellularandWiFi.It isdifficulttopredicthow
long this growth will continue for and difficult to know how well placed operators are to make use of network
enhancementsandsmallercellstoaccommodatethistraffic.Iftrafficgrowthcontinuesaspredictedthereisastrong
likelihoodthatcellularoperatorsaroundtheworldwillfaceincreasedcapacityconstraints.Thisreporthelpsprovide
further evidence as to the extent of the growth and discusses possible solutions to the problem. As such it is a
valuablecontributiontoadebatewhichwillunfoldoverthecomingmonthsandyears.
Thisreportsuggeststhatakeypartofthesolutiontoresolvingthiswill lie inoperatorsgainingaccesstoadditional
spectrum;however,asexplained intheReport,morespectrumwillonlybepartofthesolution. Astheyare inthe
process
of
doing
in
the
U.S.,
operators
will
also
need
to
explore
new,
more
efficient
technologies,
or
new
architectures, such as picocells and femtocells and decide on the best balance of all of these solutions to deliver
sufficientnetworkcapacity.
Manyentitiesareinterestedinmorespectrumbutthosethatvalueitthemostwillbetheoneswhocanquicklyput
thespectrumtouseandearnthegreatestreturnonthecapitaltheyinvest.Ensuringthatspectrumismadeavailable
tothosethatvalueitthemostandinatimelymanneristheroleofthenationalregulator theFCCintheUS,Ofcom
intheUK,etc.Someofthemostprogressiveregulatorsaremakinguseofthemarkettoachievethis;usingauctionsas
theonlyeffectiveandtransparentwaytoensurethatclearedspectrumgoestothosethatcangeneratethegreatest
value from itand trading toallow spectrum that is inuse tochangeownershipasoptimaluseschangeover time.
Maximumflexibilityisachievedthrougha"technologyandpolicyneutral"approachthatallowsanypieceofspectrum
tobe
used
by
any
technology
and
without
associated
policy
constraints
such
as
the
need
to
provide
services
to
particularsetsofusersorcommunities(theseimportantrequirementscanbeaddressedinotherways).
The final piece in this puzzle is a recognition that spectrum in the frequency bands below around 45GHz (with
important exceptions) is generally more valuable used in a licensed application rather than licenseexempt or
"spectrum commons." Research in the UK has shown that licensed applications such as cellular and broadcasting
generatefarmorevaluetotheeconomythancommonsusageinthecaseoftheUKonly1%ofthetotalvaluefrom
theuseof spectrum was generated bycommonsusage such asWiFi. Other developedcountriesare likely to see
similarnumbers.Sincemostcommonsusageisshortrangeitthereforemakessensetoplaceitabovethefrequencies
that are readily usable for cellular and broadcasting. However, bands such as at 2.4 GHz are an exception to this
becausetheywouldbeoflimitedusetocellularduetotheinterferencealreadyoccurringintheband.Inpassing,itis
alsoworthnotingthatwhileinnovationoccursincommonsitalsohappensinlicensedbands,andindeedmanyofthe
most important innovations of the last decade such as GPS, wireless email, mobile TV, texting and more have all
occurredinlicensedspectrum.
Cellularcommunicationsprovidesgreateconomicvaluetoacountryandtheadditionofhighspeeddatacapabilities
canonlyincreasethatvalue.Ensuringthatthereareasfewbarriersaspossibletoitswidespreaddeploymentshould
helpgrowthisvaluemuchfurthertothebenefitofallinthecountry.Anyworkthatcanhelpinformthisisavaluable
contributiontothedebate.
8/13/2019 2008 12 Rysavy Spectrum Demand
5/24
1 IntroductionWirelesstechnologyupholdsavibrantindustryattheheartoftheAmericaninformationeconomywith
morethan264millionsubscribersintheUStoday.ArecentCTIAstudyanticipatesthatthetotalvalueof
mobilebroadbandandvoiceserviceswillexceed$427billionbytheyear2016,contributing$860billion
tothe
Gross
Domestic
Product
over
the
next
ten
years.1
Increasingly,
subscribers
are
using
mobile
data
serviceswithnonvoicerevenuegrowing40%inthefirstsixmonthsof2008.2
The confluence of the Internet and mobile/wireless computing is accelerating the consumption of
spectrum. With data applications able to consume far more bandwidth than voice and with an
increasingnumberofmobileusersengaging inevermorebandwidthintensiveapplications, itisonlya
matteroftimebeforecurrentcommercialmobileradiospectrumisexhausted.
Thisreportsummarizesthemarketfactorsbehindthegrowthofmobilebroadbandincludingitemssuch
as critical massmarket adoption, use of highbandwidth applications, smartphone platforms that
facilitateandstimulatedemandformobiledataapplications,innovativepricing,andacceleratingfixed
mobilesubstitution.
This
report
also
provides
aquantitative
analysis
of
demand
for
licensed
spectrum
anddiscussesthespectrumneedsofadvancedtechnologies.
Within the next decade, significant amounts of additional licensed spectrum will be imperative for
expanding networks towards a ubiquitous mobile Internet, one that provides national economic
advantagesandthathelpsprovidebroadbandtoeveryAmerican.
While some operators have attempted to use unlicensed spectrum to augment or take the place of
widearea, licensed mobilebroadband networks (e.g., municipal and metro WiFi networks), these
unlicensed networks have experienced technical and business difficulties including poor indoor
coverage.Therefore, they remainanunproven solution toexpecteddemand formorespectrum. The
focusof
this
report
is
thus
on
licensed
spectrum
and
the
US
mobile
networks
that
depend
on
it.
2 MarketFactorsWeareatauniqueandpivotaltimeinhistory,inwhichtechnologycapability,consumerawarenessand
comfort with emerging wireless technology, and industry innovation are converging to create mass
marketacceptanceofmobilebroadband.Thesemarketfactorsareactingmultiplicativelytoaccelerate
usageofspectrumbasedservices.TheSr.VPofEngineeringandOperationsatTMobilerecentlystated
Weareonthevergeofanexplosioninmobilebroadband.3
Themarket factorscontributingtothis impendingexplosionareshown inthe followingfigureandare
discussedbelow.
1StudyShowsU.S.EconomyGetsMajorBoostfromWirelessBroadband,May29,2008
http://www.ctia.org/media/press/body.cfm/prid/1755.
2StatisticsreleasedbyCTIA9122008attheCTIAWIRELESSI.T.&Entertainment2008show.
3 Neville Ray, Sr. VP of Engineering and Operations, Operator Panel, 3G Americas Analyst Conference, Dallas,
October14,2008.
http://www.ctia.org/media/press/body.cfm/prid/1755http://www.ctia.org/media/press/body.cfm/prid/17558/13/2019 2008 12 Rysavy Spectrum Demand
6/24
Figure1:MultiplicativeEffectofMultipleMarketFactors
2.1 CriticalMass-MarketAdoptionWith
the
percentage
of
wireless
users
taking
advantage
of
the
mobile
Internet
growing
quickly,
the
market is reachingcriticalmass, inwhich theexpandingmarketjustifiessignificant investmentby
large companies. Recent entrants such as Apple (iPhone) and Google (Android smartphone
platform)aretwovisibleexamples.AsofMay2008,thenumberofactiveusersofmobileInternet
services in the UShaddoubled to 40 million users fromjust two years previously.4 A far greater
numberalreadyusetextmessagingandarepoisedtostartengaginginmoresophisticatedservices.
Ericssonpredictsthatmobilebroadbandsubscriptionswillmatchwirelinebroadbandsubscriptions
onaglobalbasisby2009andwillexceedwirelinebyafactoroffourby2013.5
The result is a rapidly expanding customer base that encourages business investment in new
networks,
in
new
devices
and
in
new
applications,
thus
further
fueling
market
growth.
2.2 UseofHigh-BandwidthDataApplicationsWhereas wireless network deployments were initially driven by voice usage, it is wirelessdata
applications that arenowprimarilydrivingcapacity demand. On latestgeneration networks,data
applications recently started to account for more traffic than voice. Popular applications such as
mobilevideoareparticularlydata intensive.Forexample,watchingaYouTubevideoonamobile
phoneor laptopconsumesalmostonehundredtimesthedatabandwidthofavoiceconversation.
Downloading a Microsoft PowerPoint file of fivemegabyte (Mbyte) size to view it on a phone or
laptopconsumesthesameamountofdataonthedownlinkasspeakingonaphoneformorethan
anhour.
Later
sections
in
this
report
examine
these
application
impacts
in
detail.
4CriticalMass TheWorldwideStateoftheMobileWeb,NielsenMobile,July2008.
5Ericsson,NorthAmericanInvestorRelationsForum,BostonAugust14,2008.
6MobileBroadbandSpectrumDemand
8/13/2019 2008 12 Rysavy Spectrum Demand
7/24
7MobileBroadbandSpectrumDemand
2.3 TrueMobileBroadbandUserExperienceWhereas previous wireless networks offered a somewhat sluggish data experience, 3G networks
(e.g.,EVDO6fromSprintandVerizon,HSPA7 fromAT&TandTMobile)areprovidinguserswitha
truebroadbandexperienceandaresupportingawiderrangeofbusinessandconsumerapplications
than ever before. These include email, Internet Web access, worker collaboration, enterprise
database access, multimedia such as video, gaming, mobile commerce, connected consumer
services(e.g.,AppleiTunes,AmazonUnbox),andsocialnetworking.Thefollowingtablesummarizes
thekeycharacteristicsofthedifferentgenerationsoftechnology.
Table1:GenerationsofCellularTechnologyandCharacteristics
Generation Technology TypicalData
ThroughputRates
Comments
1 Analog Data generally not
used
First cellular systems. Deployed in the
1980s.
2
Digital
100
thousand
bits
persecond(kbps)
Deployedin
the
1990s.
3 Digital 1 million bits per
second(Mbps)
Deployment began this decade. Now
widelyavailable.
4 Digital 10 Mbps or higher
expected
No standards exist yet, but requirements
being developed. Deployment expected
duringnextdecade.
Asaresult
of
the
improving
throughput
rates
that
make
more
applications
feasible,
3G
users
are
significantly more likely to engage in a higher number of data sessions than 2G users. Lehman
Brothersnotesthat3Gdevicesdrive20%higheraveragerevenueperuser(ARPU)than2Gdevices
and integrated devices (those with QWERTY keyboards) driving almost double the revenue.8
Simultaneously,thenumberofUSsubscriberswith3Gdevices isshowingrapidgrowth,measuring
80%during thepastyear to64.2millionsubscribers.9Agreaternumberofuserswith3Gdevices
engaginginmoredataapplicationsdirectlytranslatestogreaterspectrumusage.Asatisfyingmobile
broadbandexperience inwhichapplicationsarefastandresponsiveencouragessubscriberstouse
6 Evolution Data Optimized, a highspeed data service for Code Division Multiple Access 2000 (CDMA2000)
networks.
7HighSpeedPacketAccess,ahighspeeddataservice forUniversalMobileTelecommunicationsSystem (UMTS)
networks.
8LehmanBrothersEquityResearch,WirelessServices,MobileData:TheEngineBehindWireless,April24,2008.
9comScore,September2008,reportedathttp://www.cellular news.com/story/33436.php .
http://www.cellular-news.com/story/33436.phphttp://www.cellular-news.com/story/33436.phphttp://www.cellular-news.com/story/33436.phphttp://www.cellular-news.com/story/33436.php8/13/2019 2008 12 Rysavy Spectrum Demand
8/24
8MobileBroadbandSpectrumDemand
moredataapplications.This,inturn,drivesoperatorstoexpandtheir3Gnetworkdeployments,as
wellastoenhancenetworkcapability,whichthenencouragesdeveloperstobuildnewmobiledata
applications. For example, there are already more than 10,000 applications for the iPhone, even
thoughthedevelopertoolswereonlymadeavailableforitthisyear.10
According to Nielsen, faster speeds, as made available with 3G and other emerging wireless
technologies, translate directly to user satisfaction, As with PC Internet use, faster data transfer
speedscloselyrelatetoconsumersatisfactionandwillhelptodriveoverallinterestandadoptionof
the platform.11 With 4G platforms12 soon to be deployed, user experiences will continue to
improve,furtherstimulatingusage.
We are witnessing the culmination of massive network investment, technology innovation and
development,spectrumdeployment,andusersophistication.Continuedgrowth,however,depends
on operators ability to keep providing users with satisfying network performance. If networks
become overloaded, the result is slower and more erratic throughput speeds, packet delays,
unreliableapplicationbehavior,anddisconnects.
2.4 SmartphoneEffectTheuseofsmartphones,phonesthatincorporatecomputerandInternetcapabilityandthatcanrun
awiderangeofdataapplications,issurging.Thisisbecauseanexpanding3Gnetworkfootprintcan
nowfullysupporttheircapabilitiesand,withrisingvolumesandeconomiesofscale,theyaremuch
moreaffordable,withmanymodelsnowpricedaround$100.MerrillLynchanticipatesthat40%of
phonescouldbesmartphonesby2010.13TheRIMBlackBerry,whichownsasignificantshareofthe
smartphonemarket,hasrevealedthehugedemandforwirelessemail,aswellasotherapplications
such as mobile Web browsing. Similarly, Apples iPhone demonstrates how a powerful handheld
computer that has an intuitive user interface can stimulate usage. Nielsens studies show iPhone
usersare
five
times
more
likely
to
use
the
mobile
Internet
than
the
average
mobile
consumer.14
WirelessWeekreportsRalphdelaVega,CEOofAT&TMobility,assayingthat95%ofiPhoneusers
regularlysurftheInternetwiththeirphonesand51%ofiPhoneuserswatchvideosonYouTube.15
10http://www.10000iphoneapplications.com/.
11CriticalMass TheWorldwideStateoftheMobileWeb,NielsenMobile,July2008.
12Atthistime,thereisnoformaldefinitionof4G.4GrequirementswillbeeffectivelydefinedinanInternational
Telecommunications (ITU) project called International Mobile Telephone Advanced (IMTAdvanced), with
requirementsexpectedin2008andfirstcompliantnetworksexpectedaround2012.Nevertheless,systemssuchas
WiMAXandLongTermEvolution(LTE)arecalled4Gplatforms,sincetheywillbeenhancedinsubsequentversions
tomeetIMTAdvancedrequirements.
13MerrillLynch,GlobalWirelessMatrix,1Q08,July18,2008.
14CriticalMass TheWorldwideStateoftheMobileWeb,NielsenMobile,July2008.
15http://www.wirelessweek.com/article.aspx?id=161884 .
http://www.10000iphoneapplications.com/http://www.wirelessweek.com/article.aspx?id=161884http://www.wirelessweek.com/article.aspx?id=161884http://www.10000iphoneapplications.com/8/13/2019 2008 12 Rysavy Spectrum Demand
9/24
9MobileBroadbandSpectrumDemand
GoldmanSachsreportssmartphoneusersasthemobiledataleaderswith88%usingtheirdevicefor
noncallingactivity.16
Other successful smartphoneplatforms includeWindowsMobile,PalmOSandSymbian.Googles
newAndroidplatformforsmartphonesisanotherexampleoftheintensedevelopmentoccurringin
handheld,mobilecomputingcapabilities.This isespeciallyrelevantwithonestudypredictingthat
by2020mobilephoneswillbetheprimaryInternetdevicesformostpeopleintheworld.17
2.5 ApplicationInnovationEffectWhencompaniesbegandeployingbroadbandnetworks,nobodyenvisionedanapplicationsuchas
YouTube.Butcapabilityencourages innovation.JustastheInternethasprovidedfertilegroundfor
new applications, it is inevitable that mobile broadband networks will spur comparable, if not
greater, innovation. This occurs through a virtuous cycle in which more capable networks enable
moreapplications,attractinggreaterusageandsubscriptionrates,encouragingmoredevelopersto
createbetterapplicationsanddevices,furtherstimulatingdemandandmarketgrowth.Operators,
seeing
a
significant
business
opportunity,
are
emphasizing
data
services
in
their
promotions,
offers,
anddevicefeatures.
Furthermore, since mobile broadband networks and the Internet are increasingly intertwined,
innovation in one readily extends to the other. Some of the key applications that appear to be
driving massmarket adoption of wireless broadband include mobile video, social networking,
enterprise productivity, usergenerated content, instant messaging, locationbased services, and
Web 2.0 applications.18 Users, particularly younger ones, are expecting the same Internet
experience on their mobile devices as that available on desktop systems and vendors are
responding.Opera,a leadingmobilebrowservendor,announced inSeptember2008 that itsnew
browser will bring the full desktop Webbrowsing experience including support for JavaScript,
acceleratedvector,
and
video
content
to
smartphones
and
mobile
Internet
devices.19
Using nextgeneration infrastructure enhancements such as IP Multimedia Subsystem (IMS),
operators will be able to make data services even more attractive by allowing applications to
combine multiple types of communications and information dynamically including messaging,
location,pushtotalkandvideo.Forexample,userswillbeabletostartan instantmessagingchat
sessionand,inmidsession,addvoiceorvideocommunications.AT&Talreadyoffersavideosharing
applicationbasedonIMS.TheseIMSapplications,particularlyvideo,willfurtherincreasespectrum
usage.
16 The Goldman Sachs Group, Inc., Americas: Wireless Mobile Data 1.1 Recent Data Points Strengthen the
Theme,June2008.
17PewInternet&AmericanLifeProject,TheFutureoftheInternetIII,December14,2009.
18Web2.0referstotechnologiesenablingrichInternetapplicationswithdynamicandinteractivecontent.
19http://www.opera.com/pressreleases/en/2008/09/09/.
http://www.opera.com/pressreleases/en/2008/09/09/http://www.opera.com/pressreleases/en/2008/09/09/8/13/2019 2008 12 Rysavy Spectrum Demand
10/24
10MobileBroadbandSpectrumDemand
2.6 InnovativePricingManyearly serviceplans forwirelessdata,aswellasvoice,werebasedonusage. In1998,AT&T
Wireless introduced the firstbucketplancalledDigitalOneRate,aplan thatprovidedsubscribers
witha largenumberofvoiceminutescombinedwithno longdistanceorroamingcharges.Usage
surged and other operators quickly offered similar plans. Today, most pricing plans follow this
model.
Similarly,flatratepricingplansformodemcardsandsmartphoneshaveresultedinuseracceptance
ofmobiledataandhavesignificantlyincreaseddataconsumption.20
2.7 Fixed-MobileSubstitutionandFixed-MobileConvergenceInsignificantand increasingpercentages,peoplearesubstitutingmobilephonesfortheirfixedline
phones. The Center for Disease Control and Preventions National Center for Health Statistics on
December17,2008announcedinpreliminaryresultsthatduringthefirstsixmonthsof2008,nearly
17.5%ofAmericanswerewirelessonly.21ThisisconsistentwithaNielsenreportthatbyJune2008,
17.1percent
of
US
households
had
substituted
awireless
phone
for
their
landline
phone
with
an
annualgrowthofthreefourpercent.22
Similarly,usersarestartingtousemobilebroadbandconnectionstotheInternetasanalternativeto
wirelineconnectionssuchasDSL.IfpeoplearealreadypayingforwirelessInternetservice,theyare
reluctanttopayseparatelyforwired Internet.Nielsenasserts,Clearly, Internetaccess isthenext
frontierofwirelesssubstitution.23MorganStanleymakesthe followingstatements,Wearealso
starting to see the early signs of wireless data substitution, as laptop cards and smartphones
proliferate. The rollouts of WiMAX and LTE will make wireless data substitution even more
compelling.Sweden&Austriahaveseenasignificant impactonDSLaddsfrommobilebroadband.
Mobilebroadbandaccountedformorethan70%oftotalbroadbandaddsinAustrialastyear.24
Furthermore, a large number of people with access to mobile broadband services may not have
access to wireline services. This is where wireless technology can address the digital divide for
broadbandservices. Infact,this isalreadyhappening forvoiceservices.TheNielsenstudyreports
that many voice substitutors are in lowerincome brackets (46% having a household income of
$50,000orless).
Lastly,todaysteenagers liveandbreathebytheirmobilephonesusingthemforvoice,messaging
and, increasingly,forsophisticatedsocialnetworkingfeatures.Webcentricmobileapplicationsare
20
Note
that
flat
rate
pricing
plans
do
have
terms
of
service
that
apply
some
restrictions,
such
as
amonthly
cap.
21http://www.cdc.gov/nchs/data/nhis/earlyrelease/wireless200812.htm.
22Nielsen,CallMyCell:WirelessSubstitutionintheUnitedStates,September2008.
23Nielsen,CallMyCell:WirelessSubstitutionintheUnitedStates,September2008.
24MorganStanley,TelecomServicesCuttingtheCord:VoiceFirst,BroadbandCloseBehind.October1,2008.
http://www.cdc.gov/nchs/data/nhis/earlyrelease/wireless200812.htmhttp://www.cdc.gov/nchs/data/nhis/earlyrelease/wireless200812.htm8/13/2019 2008 12 Rysavy Spectrum Demand
11/24
11MobileBroadbandSpectrumDemand
ofgreater interesttopeopleunder25thananyotheragegroup.25Manyoftheseyoungerpeople
mayneverhaveanyinterestinawirelineconnection.
Anothermarket driver for spectrum consumption is fixedmobileconvergence (FMC), referring to
the ability to use mobile devices in a stationary (e.g., home) environment by connecting to local
accesspointseitherviaWiFiorvia licensedcommercialmobile radiospectrumusing femtocells.
Thereareavarietyofarchitecturalapproaches forprovidingFMC,but theneteffect isthatusers
will increasingly use their mobile devices in all environments and for all communications, thus
furtherstimulatingspectrumdemand.
3 QuantitativeAnalysisIncreased mobile broadband use such as from the proliferation of smartphones with a consumer
friendlyformfactor isalreadyhavinganoticeable impactonexistingnetworks.YankeeGrouprecently
stated, Few operators today are capacity challenged but they anticipate they will be, and some
operatorsanticipatethiswithurgency.26
Thereareavarietyofofmetricsavailabletosubstantiatetheincreasingamountsofdataandspectrum
thatwirelessapplicationsareconsuming.Suchananalysisprovidesinsightintothecapacityandlimitsof
todaysnetworksandavailablespectrum.
Sincewirelessoperatorsdonotdisclosethepreciseamountoftrafficandloadingontheirnetworks,this
section uses a variety of other information to assess the demand being placed on spectrum. This
includesthegeneralgrowthofInternetProtocol(IP)traffic,currentandprojectedmobiledatagrowth,
andthecapacityofwirelessnetworksrelativetoapplicationandsubscriberdemands.
3.1 GrowthinIPTrafficThere
is
tremendous
growth
in
the
overall
amount
of
global
Internet
Protocol
(IP)
traffic.
Cisco
projects a doubling of IP traffic every two years through 2012.27 This growth will be through
combination of bandwidthintensive applications such as video distribution, and from general
Internet usage. With mobile Internet connectivity becoming the primary wireless application,
Internettrafficgrowthtranslatestomobilebroadbandtrafficgrowth,butatanevenfasterratedue
toarapidlygrowingbaseofusers.
3.2 CurrentMobileDataGrowthMobileoperatorsarealreadyexperiencingnotablevolumesofdatatrafficontheirnetworks.Some
examples of the current growth in mobile broadband data traffic follow. Ericsson, a leading 3G
25AlcatelLucent,EnrichingCommunications Magazine,NorthAmericaEnteringEraof IntegratedBusinessand
TechnologicalInnovation,http://www.alcatel lucent.com/enrich/v2i22008/article_c1a6.html?l=en.
26YankeeGroupWebcast,FindingaFemtoFuture,June26,2008.
27Cisco,ApproachingtheZettabyteEra,June16,2008.
http://www.alcatel-lucent.com/enrich/v2i22008/article_c1a6.html?l=enhttp://www.alcatel-lucent.com/enrich/v2i22008/article_c1a6.html?l=enhttp://www.alcatel-lucent.com/enrich/v2i22008/article_c1a6.html?l=enhttp://www.alcatel-lucent.com/enrich/v2i22008/article_c1a6.html?l=en8/13/2019 2008 12 Rysavy Spectrum Demand
12/24
12MobileBroadbandSpectrumDemand
infrastructure vendor, indicates that data traffic is already three times voice traffic on UMTS
networkstheyhavemeasuredwiththeprevious12monthsexperiencingmorethanadoublingof
data traffic.28 Ofcom, the independent regulator and competition authority for the UKs
communications industries, provides data on two European operators in a recent report showing
thatdata trafficonH3Gsnetworkgrewbya factorofseven inasixmonthperiodendingMarch
2008,and
that
Vodafone
is
experiencing
similar
growth
with
data
traffic
exceeding
voice
traffic.29
Theseexamplesdemonstratethe rapidgrowth inmobilebroadband trafficalreadyoccurring.The
nextsectionlooksathowsuchgrowthwillcontinueintothefuture.
3.3 ProjectedMobileDataGrowthAT&Tprojects(againstabaselineof2Gdatatrafficin2007)thatby20183G/4Gtrafficwillexpand
byafactorof250 (conservativeestimate)to600(aggressiveestimate).30 Incontrast,AT&Tshows
voicetraffictriplingduringthatsameperiod. Inotherwords,datatrafficwillgrowatarateabout
onehundred timesgreater thanvoice trafficover thenext tenyears.ACAGR (CompoundAnnual
Growth Rate) analysisof the AT&T figures showsbetween 130 and 170% CAGR of data between
2007and
2010,
and
between
65%
and
80%
CAGR
between
2007
and
2018.
Cisco
projects
125%
CAGRgrowth inmobilebroadbandtrafficthrough2012.31The importanceofthesegrowthrates is
thatitisunlikelythatoperatorswillbeabletodeliversatisfactoryserviceinthefutureatthesehigh
trafficvolumesusingexistingspectrum.
The following figure shows the Cisco projections of global mobile broadband traffic measured in
petabytes(milliongigabytes)permonth.32
28Ericsson,NorthAmericanInvestorRelationsForum,BostonAugust14,2008.
29FinalreportforOfcom,AssessmentoftheUKMobileSector,AnalysisMason,28August,2008.
30HSPA:KeystoaSuccessfulBroadbandAccessStrategy,TomKeathley,VPRadioAccess&Standards,AT&T.HSPA
Workshop,MobileWorldCongress,http://www.3gamericas.org/English/Events/hspaworkshop.cfm.
31Cisco,ApproachingtheZettabyteEra,June16,2008.
32CiscoshowstheUSaccountingfor43%ofglobalIPtraffic.
http://www.3gamericas.org/English/Events/hspaworkshop.cfmhttp://www.3gamericas.org/English/Events/hspaworkshop.cfm8/13/2019 2008 12 Rysavy Spectrum Demand
13/24
Figure2:CiscoMobileBroadbandProjection(petabytespermonth)
0
200
400
600
800
1000
1200
1400
1600
2005 2006 2007 2008 2009 2010 2011 2012 2013
Between 2008and 2012, the Cisco projections indicate mobile broadband IP traffic growing by a
factorof23.
3.4 CapacityofWirelessNetworksRelativetoApplicationDemandTo lookatthe impactofdataapplicationsonwirelessnetworks,onemustconsidertheamountof
bandwidthavailableandtheamountofspectrumconsumedbyapplications.Thisallowsonetosee
howmanypeopleusingwhichapplicationscurrentnetworkcapacitycansupportandhowcurrent
capacitywillneedtobeaugmentedinthefuture.
First,there
is
the
question
of
how
to
equate
capacity
with
spectrum.
This
requires
an
understanding
of spectralefficiency, which is the throughput measured in bitsper second (bps) thatacoverage
areacansupportonanaggregatebasisrelativetotheamountofspectrumused,measuredinHertz
(Hz). In other words, determining spectral efficiency tells us the total bandwidth of the network
relativetotheamountofspectrumused.
Todays wireless technologies have a spectral efficiency close to 0.75 bps/Hz (after network
overhead)forthedownlink.Therefore,1MHzofspectruminacellsector33canprovide,onaverage,
0.75 Mbps of total aggregated data throughput for all the users in the coverage area. Future
technologiessuchasLongTermEvolution(LTE)areexpectedtohavespectralefficiencyclosertoa
valueof1.5.ThesespectralefficiencyvaluesarebasedonworkthatRysavyResearchhasperformed
with3GAmericasandrepresentaconsensusviewofmultipleoperatorsandvendors.34
33Cellsitestypicallyaredividedintothreesectors.
34 Rysavy Research, EDGE, HSPA, LTE Broadband Innovation, published by 3G Americas, September 2008.
Uplinkstypicallyhaveabouthalftheefficiencyofdownlinks.
13MobileBroadbandSpectrumDemand
8/13/2019 2008 12 Rysavy Spectrum Demand
14/24
14MobileBroadbandSpectrumDemand
Thecapacityofawirelessnetworkinanygivenlocationthusdependsonthespectralefficiency,as
wellastheamountofspectrumtheoperatorhasavailable.
Thefollowingtableillustratessomeofthesectorthroughputsbasedonavailablebandwidth.
Table2:AvailableSectorThroughputsBasedonBandwidthandTechnology
Technology BandwidthAssumption SpectralEfficiency DownlinkSector
Throughput
EVDO Oneradiocarrierof1.25MHz 0.75 0.94Mbps
UMTS/HSPA Assumesentire5MHzradio
channelusedfordata
0.75 3.75Mbps
WiMAX 2/3of10MHz(timedivision
duplex)radiochannelallocated
fordownlink
1.0 6.7Mbps
LTE
10MHz
radio
channel
all
availablefordata
1.5
15Mbps
Thesesectorthroughputorcapacityvalues,however,arenot fixed.Operatorscanaugmentthese
capacity amounts by deploying additional spectrum and adding radio channels assuming the
operatorhasaccesstoadditionalspectrum.Forexample,ifaCDMAoperatorhadtwoEVDOradio
channels deployed in a particular coverage area, then the sector capacity would double. As for
actualuserthroughputs,EVDOoperatorssuchasVerizon indicatetypicalthroughputratesof600
kbps (thousandsofbitspersecond)to1.4Mbps (millionsofbitspersecond)andHSPAoperators
suchas
AT&T
state
700
kbps
to
1.7
Mbps.
Actual
throughput
rates
depend
largely
on
signal
quality
andnetworkloadinginaparticulargeographicarea.Asthenumberofactiveusersonthenetwork
increases inaspecificarea,particularlydatausers,throughputsforeveryonedecrease.Essentially,
the capacity of a cell is divided among all active users accessing that cell. A cell will become
saturatedatsomepoint,andtheresultwillbeslowanderraticservice.
Giventhephysicalrealityjustexplained,mobilenetworkoperatorsareimplementingorconsidering
various mechanisms to manage bandwidth usage in the absence of access to more licensed
spectrum. Efforts may include instituting monthly usage caps, encouraging offpeak usage, and
othernetworkmanagementtools.Ifconsumersperceiveanoperatorsmanagementtechniquesas
being
too
restrictive,
however,
the
value
of
the
service
diminishes.
This
could,
in
turn,
reverse
the
consumerdemand trendsummarizedabove,whichwill thenarrest theoperatorsefforts tokeep
enhancingnetworkcapacityandcapabilitytostayaheadofconsumerdemand.
To see how much usage these capacity values can sustain, one can examine the throughputs
requiredfordifferentapplications,asshowninthefollowingtable:
8/13/2019 2008 12 Rysavy Spectrum Demand
15/24
15MobileBroadbandSpectrumDemand
Table3:ApplicationBandwidthRequirements
Application Bandwidth
Mobile voice call 6 kbps to 12 kbps
Low-quality music stream 28.8 kbps
Medium-quality music stream 128 kbps
High-quality music stream 300 kbps
Video conferencing 384 kbps to 3 MbpsEntry-level, high-speed Internet 1 Mbps
Internet streaming video 1 Mbps
Telecommuting 1 to 5 MbpsGaming 1 to 10 MbpsEnterprise applications 1 to 10 MbpsStandard definition TV 2 MbpsDistance learning 3 MbpsBasic, high-speed Internet 5 MbpsHigh-Definition TV 7.5 to 9 Mbps
Multimedia Web interaction 10 MbpsEnhanced, high-speed Internet 10 to 50 Mbps
Eventhoughnotallsubscribersofanetworkareactiveatthesametime,itisquiteclearthatseveral
userswithin
the
same
cell
sector
engaging
simultaneously
in
high
throughput
applications
(e.g.,
videostreaming)canquicklystrainthenetwork impactingtheuserexperienceforeveryconsumer
accessingthenetwork,even iftheyarenotthemselvesengaging inbandwidthintensiveactivities.
RysavyResearchhasconfirmedthisinactualtestsinwhichfoursimultaneoususersona3Gnetwork
in the same location resulted in decreased throughput speeds of less than60% compared to the
unloadedcase.35Mobileapplicationssuchasmoviedownloadsandvideostreamingarebecoming
more popular and have the potential to consume available capacity in todays mobile networks.
Videoconsumesmorebandwidththanalmostanyotherapplication.AspeopleaccesstheInternet
todownloadmoviesandothervideoentertainment,theamountofdataconsumedbymobilevideo
will balloon, because consumers will not settle for accessing video only through their wireline
connections.They
will
expect
and
demand
that
such
content
be
accessible
through
their
mobile
broadbandconnections.
35RysavyResearchWirelessNetworkAssessment,2006,
http://www.rysavy.com/Articles/Rysavy_Wireless_Performance.pdf.
http://www.rysavy.com/Articles/Rysavy_Wireless_Performance.pdfhttp://www.rysavy.com/Articles/Rysavy_Wireless_Performance.pdf8/13/2019 2008 12 Rysavy Spectrum Demand
16/24
16MobileBroadbandSpectrumDemand
Giventhefinitecapacitylimitsexplainedabove,manyapplicationdevelopershaveemployedhighly
efficient wireless application architectures often implemented via mobile middleware, as well as
through highly compressed data objects. These approaches have helped mitigate the bandwidth
consumptionofcertainpopularmobileapplicationswhilealso improvingapplicationperformance.
But application optimization alone will not resolve the bandwidth needs to support continuing
escalatingdemand.
3.5 MonthlyUsageAnalysisThe second approach this report uses to examine spectrum demand is by examining the total
monthlyusageoftypicalapplications.
Toestimate themonthlyconsumptionofdifferent typesofapplications,onemustmakeacertain
numberofassumptionsaboutusage.Someestimatesareasfollows:
EMail. Email volume depends heavily on how many attachments a user downloads.Assuming500messagespermonthof10Kbytes,and50ofthesewith1Mbyteattachments,
thisrepresents
arelatively
modest
55
Mbytes
per
month.
Note
that
handheld
devices
such
asRIMBlackBerryarehighlyoptimized intheirnetworkcommunicationsandconsume far
lessdata.36
WebBrowsing.Theamountofdatacanvaryconsiderably,but forauserbrowsingtypicalgraphical/pictorial content and not viewing video, 10 Mbytes/hour is a reasonably
representativevalue.37Twentyhourspermonthisonly200Mbytes/month,stillarelatively
lowloadonthenetwork.
Internetradio.Internetradiostreamstodayoperateatratesofupto300kbpsconsuming135Mbytesofdataperhour.Twentyhourspermonthis2.7Gbytes/month.
Video.PopularvideostreamingapplicationssuchasFlashorMicrosoftSilverlightcurrentlyoperateatcloseto1Mbps38.Thisconsumes.45Gbytesperhour.Thisisalsocomparableto
downloading a onehour video from Apples iTunes store, which takes about .5 Gbytes.
Twenty hours per month at .45 Gbytes/hour is 9 Gbytes/month, significantly higher than
whatmostwirelessnetworkspermittoday.It is importanttonotethattherearearapidly
increasing number of videodownload and streaming services available to users such as
Amazon Unbox, Movielink, Netflix, MobiTV, Sling Media, Hulu, and shows from the TV
networks themselves. During the 2008 Olympics,NBChadmore contentavailablevia the
WebthanontheirmultipleTVchannels.
36RysavyResearch,WirelessEMailEfficiencyAssessment,April21,2008.
37RysavyResearchmeasurements.Assumessomenumberofdocumentsdownloaded.
38RysavyResearchmeasurements.
8/13/2019 2008 12 Rysavy Spectrum Demand
17/24
HD movie downloads. Todays highdefinition video requires at least 7.5 Mbps ofbandwidth,whichconsumerswatchedatarateof3.4Gbytesperhour.Justonetwohour
movie per week is 27 Gbytes/month, clearly a challenging application for todays mobile
broadbandnetworks.
The following graph shows the application examplesjust listed. The video applications already
exceedthemonthlylimitsthatmanywirelessoperatorsimposeontheirsubscribers.
Figure3:TypicalConsumptionofApplicationsOverOneMonthPeriod(Megabytes)
0
5000
10000
15000
20000
25000
30000
Email WebBrowsing InternetRadio Vide o
Streaming
HDMovies
While todays mobile networks have sufficient capacity to address current active subscribers and
current usage behavior, emerging multimedia applications will impose significant additional
bandwidthdemands.
The
amount
of
data
that
these
applications
can
consume
is
likely
to
exceed
the
capacityofmanyexistingmobilenetworksonceusagebecomeswidespread.
Somemayarguethatsmallerformfactordeviceslikehandheldswillnotconsumeasmuchdataas
largerdevices.Forexample,ascreenonaphonedoesnotrequireashighabitrateforvideoasa
laptop screen, which similarly does not require the bit rate of a large TV. While this is true,
innovativeapplicationssuchastherecentlyavailableGoogleEarthfortheiPhonecanstillsendlarge
amounts of data to small devices. In addition, resolution of displays on handheld devices is
continuing to increase, and many devices themselves are becoming larger with new device
categoriessuchasMobile InternetDevicesbeingcreated.Thesmaller form factorwill thusnot
alleviatethe
expected
demand
for
more
network
capacity.
Userswillalsoexpectsimilarexperiencesfrommobilebroadbandnetworksasfromfixednetworks,
and many willnot differentiatebetween themjustasusers today donotdistinguish betweenan
Ethernet connection or WiFi connection in terms of capability. Failure to satisfy consumer
expectations in this area could artificially depress demand for mobile broadband and, therefore,
17MobileBroadbandSpectrumDemand
8/13/2019 2008 12 Rysavy Spectrum Demand
18/24
18MobileBroadbandSpectrumDemand
reverse the trend of expanding the capacityandcapability of wirelessnetworks to stayahead of
demand.
3.6 CapacityofWirelessNetworksRelativetoAverageSubscriberUsageAnotherwayofanalyzingthecapacityofanetworkandthenumberofdatausers itcansupportis
throughan
analysis
of
the
average
throughput
per
subscriber.
This
differs
from
the
previous
sections
that examined instantaneous peak throughputs of different applications and their monthly
consumption.
Wireline broadband services have been available for quite some time, and trends in data
consumption are fairly well understood. Based on this information, wireline Internet service
providers (e.g., cable modem or DSL) design their networks to accommodate the total average
demand of their subscribers. These data consumption values apply directly to mobile broadband
networks as people in increasing numbers turn to mobile devices for Internet access. Siavash
Alamouti,CTO of the Mobile Wireless Group at Intel, states that the killer application for mobile
broadband
networks
such
as
WiMAX
is
anything
the
Internet
can
provide
today
and
possibly
more.39 In other words, the Internet is the application, so Internet consumption trends are
particularly relevant for understanding mobile broadband network demands. A Goldman Sachs
comment on smartphones concurs, The larger screen size and improved user interface of these
newdevicesarehelpingtomorecloselymatchtheuserexperienceinthewirelessworldwiththat
ofthewiredworld.40
A typical average throughputperInternet subscriber value used today is about 50 kbps per
subscriber.Forinstance,aNovember2007DOCSIS(DataoverCableServicesInterfaceSpecification)
analysis indicatedaverageusageof40kbpsdownstreamand20kbpsupstream.41A40kbpsvalue
may seem extremely low compared to the multimegabitpersecond throughputs available with
DOCSIS,but
this
value
takes
into
account
that
only
asubset
of
users
are
active
at
any
one
time
and,
of these, only some are communicating data at any moment in time. The average loadper
subscriberisthusanimportantnumberforpredictingthedemandonthetotalnetwork.
Theseaveragedemandvalueswillkeep rising forbothwirelineandwirelessnetworksas Internet
usagecontinuesto increase.DiscussinghowtoplanWiMAXnetworks,NokiaSiemensNetworks,a
wireless infrastructure vendor, projected in 2007 persubscriber, average throughput rates of 50
kbpsto100kbpswithinthreeyears.42
39MobileWiMAX:Vision&Evolution,http://www.ieeemobilewimax.org/downloads/Alamouti.pps.
40 The Goldman Sachs Group, Inc., Americas: Wireless Mobile Data 1.1 Recent Data Points Strengthen the
Theme,June2008.
41CommunicationsTechnology.November1,2007,DOCSISMigrationMethodology,FromAtoBto"3",BySaifur
Rahman,http://www.cable360.net/ct/operations/bestpractices/26403.html.
42http://www.telecomasia.net/article.php?type=article&id_article=4742&id_sector=16.
http://www.ieee-mobilewimax.org/downloads/Alamouti.ppshttp://www.ieee-mobilewimax.org/downloads/Alamouti.ppshttp://www.ieee-mobilewimax.org/downloads/Alamouti.ppshttp://www.cable360.net/ct/operations/bestpractices/26403.htmlhttp://www.telecomasia.net/article.php?type=article&id_article=4742&id_sector=16http://www.telecomasia.net/article.php?type=article&id_article=4742&id_sector=16http://www.cable360.net/ct/operations/bestpractices/26403.htmlhttp://www.ieee-mobilewimax.org/downloads/Alamouti.pps8/13/2019 2008 12 Rysavy Spectrum Demand
19/24
19MobileBroadbandSpectrumDemand
One can apply the average demand value to mobile networks as follows. Assuming a 50 kbps
averagethroughputpersubscriber,andusingthepersectorcapacities inTable2,onecanreadily
seethattheHSPAcellsectorcouldsupportonly75subscribers(3.75Mbpsdividedby50kbps)and
theLTEcell sector could support300 subscribers (15Mbpsdividedby50kbps). In theUS today,
there are, on average, over 1,000 subscribers for the major operators per cell site or over 333
subscribersper
cell
sector.43
Clearly,
the
HSPA
cell,
with
one
radio
channel,
could
not
accommodate
all of its subscribers using data at current Internet levels. While today there are not a sufficient
numbersofmobilebroadbanduserstosoakupallavailablecapacity,Internettrends indicatethat
capacitywilleventuallybeconsumed.
There is another important consideration with respect to demand, namely peak geographic
demand. The previous discussion was based on average persubscriber demand but, in practice,
peaknetworkdemandsareoften localized (e.g.,Presidential Inauguralevents inWashington,DC,
large sporting events, roadtraffic situations, highdensity residential areas). Peak geographic
demandscanbesignificantlyhigherthanaveragedemands.Theindustryneedsenoughspectrumto
accommodate
both
average
demands,
as
well
as
peak
geographic
demands.
Therearethreewaysof increasingnetworkcapacity: increasedefficiency(e.g.,spectralefficiency)
ofnewwirelesstechnologies,morecellsitesanddeploymentofadditionalspectrum.
Operatorsemployallthreemethods.Theevolutionfromanalogtodigital,andnowto3Gandnext
generationsystems isoneof improvingspectralefficiency. Increasedspectralefficiency,however,
requires progressively more complex radio implementations and works best in lowmobility, low
noiseandlowinterferenceenvironments.Moreover,thereareboththeoreticalandpracticallimits
to spectral efficiency and current systems are approaching these limits.44 Improving spectral
efficiencyisanimportanttoolforcreatinggreaternetworkcapacity,butalonewillnotbesufficient
toaddressthemagnitudeoftheexpecteddemandformorebandwidth.
Increasingthenumberofcellsitescanalsodramatically increaseoverallnetworkcapacityandhas
beenthetooloperatorshaveusedmostfrequentlytoexpandcapacitysincetheinceptionofcellular
networks.Thewholebasisofcellular istoefficientlyreusespectrumand thesmaller thecell, the
greaterthecapacityperunitarea(e.g.,todayscellsitesareeasilyonetenththediameterofearly
sites).Operatorswillcertainly increasethenumberofcellsitestheydeploybut,aswithincreasing
spectralefficiency,sotootherearepracticallimitstowhatcanbeaccomplishedbyaddingcellsites.
Operatorsarealsodeployingpicocellstoaugmentcoverage,butthisonlyaddressescoverageand
capacityforverylocalizedareas.
43Basedonindustryestimatesofapproximately220,000cellsitesintheUS.Forexample,seePaulWeiss,Current
TelecomDevelopments,December5,2008.
44Foramoredetaileddiscussionofthespectralefficiencyofwirelesstechnologies,andevolutionofcapability,
refertotheRysavyResearchpaper,EDGE,HSPA,LTEBroadbandInnovation,September2008,
http://www.rysavy.com/Articles/2008_09_Broadband_Innovation.pdf.
http://www.rysavy.com/Articles/2008_09_Broadband_Innovation.pdfhttp://www.rysavy.com/Articles/2008_09_Broadband_Innovation.pdf8/13/2019 2008 12 Rysavy Spectrum Demand
20/24
So,whilegreaterspectralefficiencyandmorecellsitesarecriticallyimportant,theyareunlikelyto
beabletoaddressincreasingcapacitydemandalone.Longterm,asshowninthefollowingfigure,it
willrequireacombinationofthesemethodsandtheadditionofspectruminorderforoperatorsto
growtheirnetworksandstayaheadofconsumerdemand.
Figure4:AddressingDemandThroughaCombinationofEfficiency,IncreasedSites,andAddition
ofSpectrum
4 OtherSpectrumConsiderationsThereare otherconsiderations that relate to spectrum for mobile broadband services.These are the
needs
of
advanced
technology,
maintaining
wireline/wireless
consistency,
spectrum
implications
of
new
wirelessarchitectures,andspectrumanalysisbyotherorganizations.
4.1 NeedsofAdvancedTechnologyNew wireless technologies such as dualcarrier HSPA, LTE, and WiMAX benefit from deployment
acrosswideradiochannelsdeliveringhigherpeakdataratesandmoreefficientuseofthespectrum.
Thesechannelsaresignificantlywiderthanthoseusedbyprevioustechnologies.Forexample,dual
carrier HSPA operates in 10 MHz (frequencydivision duplex), WiMAX currently in 10 MHz (time
division duplex), LTE in up to 20 MHz (FDD and TDD), and forthcoming technologies such as LTE
Advancedinupto40MHz(FDDandTDD)radiochannels.
Allocatingwider
channels
in
existing,
licensed
spectrum
bands
to
accommodate
new
technologies
while continuing to support legacy technologies is technically and operationally difficult, because
operators typically do not have large blocks of unused spectrum available across their coverage
areas. Deployment of new technologies will be greatly simplified if done through new, licensed
bands.ThisisverylikelythereasonoperatorssuchasVerizonhaveindicatedtheywilldeployLTEin
20MobileBroadbandSpectrumDemand
8/13/2019 2008 12 Rysavy Spectrum Demand
21/24
21MobileBroadbandSpectrumDemand
theirnewlyobtained700MHzband.Beyondcoexistence,manyexistingbandsaresimplynotwide
enoughtoaccommodatetheseforthcomingwirelesstechnologies.
Thespectrumneedsofemergingmobiletechnologieshavebeenaddressedbyorganizationssuchas
NextGenerationMobileNetworks (NGMN),whichstates:Fulldeploymentsofnextgenerationof
mobilenetworksrequire20MHzchannels.Morethan120MHzofharmonisedspectrumwouldbe
neededtoaccommodatecommonlyenvisageddeploymentscenarios(involvingparameterssuchas
number of channels, number of operators, and choice of FDD or TDD technology). NGMN also
states To reach the full potential of next generation mobile networks, larger channels (up to
approximately100MHz, inhigherfrequencybands)willbeneeded.45Further, itshouldbenoted
that the ITU is already developing requirements for nextgeneration systems that will include
operationinupto40MHzradiochannels,whichiswiderthanmanyexistingbands.46
4.2 ConsumerExpectationsAswirelinespeeds increase,userswillexpectcomparableexperienceswithmobilenetworks.Any
huge
discrepancy
will
hamper
adoption,
because
users
will
find
the
wireless
experience
unsatisfactory relative to wireline. For instance, if a user usually experiences a download time of
secondson awirelinenetwork for aWebpage,he or she isunlikely tobe satisfiedbydownload
timesof20secondsorgreateronawirelessnetwork.
Historically, there has been about a 10:1 difference in maximumthroughput speeds between
wirelineandwirelessservices,asshown inFigure5.Withpremiumconsumerwirelinespeedsnow
at50MbpsdownstreamthroughDOCSIS3.0andfibertothehome,enhanced3Gnetworksand4G
technologiesneedtobedeployedinsufficientlywideradiochannelsandwithsufficientcapacityto
offercomparableuserexperiences.
45 Spectrum Requirements for the Next Generation of Mobile Networks, NGMN White Paper on terrestrial
networks,June2007.
46 Requirements, evaluation criteria and submission templates for the development of IMTAdvanced, 2008
http://www.itu.int/ITUR/studygroups/docs/imtadvancedAtt7.2.doc.
http://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.dochttp://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.dochttp://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.dochttp://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.dochttp://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.dochttp://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.dochttp://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.dochttp://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.dochttp://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.dochttp://www.itu.int/ITU-R/study-groups/docs/imt-advanced-Att7.2.doc8/13/2019 2008 12 Rysavy Spectrum Demand
22/24
Figure5:WirelineVersusWirelessDownlinkCapabilities(ActualUserThroughputs)
20102000 2005
100 kbps
10 kbps
1 Mbps
10 Mbps
100 Mbps
2G
40 kbps
Initial 3G
350 kbps
Current 3G
1 Mbps
3G+
5 Mbps
Pre 4G
10 Mbps
2G+
100 kbps
DSL/Cable
1 Mbps
DSL/Cable
3 to 5 Mbps
DSL/Cable
10 Mbps
Cable/Fiber
50 Mbps
Cable/Fiber
100 Mbps
4.3 NewWirelessArchitecturesandSpectrumImplicationsSomehavepointedtonewwirelessarchitecturessuchasfemtocellsandmobileTVbroadcastasa
meansofoffloadingthewideareanetworks.Whiletheseapproachesarequiteeffective,theyhave
limitations.Figure6showsthefemtocellconcept,namely,tohavetinybasestations(accesspoints)
locatedoncustomerpremises.Thisapproachallowsspectrumtobereusedatamuchhigherfactor
than the widearea network, effectively giving each subscriber the full bandwidth of the radio
channel.
Figure6:FemtoCellsforCapacityIncrease
Macro-Cell
Coverage
Femto-Cell
Coverage
Aggregate femto-cell
capacity far exceeds
macro-cell capacity
for same amount
of spectrum
Forapplicationssuchasmediatransfer,femtocellswillsignificantlyoffloadthewideareanetwork.
The femtocell architecture, however, assumes that a customer already has a wireline Internet
connection to provide the backhaul connectivity between the access point and the operator
22MobileBroadbandSpectrumDemand
8/13/2019 2008 12 Rysavy Spectrum Demand
23/24
23MobileBroadbandSpectrumDemand
network.Thus, femtocellsdonotwork if thegoal is formobilebroaband tobeanalternative to
wirelineconnectivity.Secondly, it isnotyetknownhowviable femtocellswillactuallybe,asthey
pose massive logistical problems in terms of spectrum management, interference (between
adjacentapartments,forexample),configurationandmanagement.Operatorstodaymanagetens
ofthousandsofcellsites,butthenumberoffemtosites,eachsimilartoacellsite infunctionality,
willnumber
in
the
millions.
Finally,whileusersmayacceptsomedegreeofenhancedcapabilitywhenincoverageoftheirfemto
cell,theywillexpect largelysimilarcapabilitieswhenusingthenetworkat large.Theneteffect is
some amount of yettobe determined capacity relief but, by themselves, femto cells are not an
alternativetoprovidingnecessaryspectrumformobilebroadbandnetworks.
Similarly,mobileTVprovidesameansofbroadcastingvideocontentsothateachuserreceivesthe
samesetofchannels.Thisismuchmoreefficientthanhavingadedicatedvideostreamtoeachuser.
Effective use of mobile TV will alleviate some network load for video content, but it is not an
alternative formanyvideoorientedapplicationssuchasYouTubethatdonotwork inabroadcast
model.
4.4 SpectrumAnalysisbyOtherOrganizationsThediscussionabovedoesnotseektoquantifyhowmuchspectrumwillbeneededbywhen;rather,
itseekstoshowthatcurrentmarketandtechnologytrendswillverylikelyresultintheexhaustionof
currently available spectrum. Other organizations, however, have studied the spectrum needs of
emerging wireless networks in depth. In particular, the International Telecommunications Union
(ITU) conducted a highly detailed analysis of spectrum needs as a basis for work on the IMT
Advanced Project. The ITU report, titled Estimated Spectrum Bandwidth Requirements for the
FutureDevelopmentofIMT2000andIMTAdvanced,47projectsatotalspectrumrequirementofas
muchas
840
MHz
by
2010,
1300
MHz
by
2015
and
1720
MHz
by
the
year
2020.
Even
at
alower
marketdevelopmentrate,theprojectionsare760MHzby2010,1300MHzby2015and1280MHz
by2020.
In the United States, only 194 MHz are currently available nationwide for CMRS use.48 However,
even when one considers the total theoretical amount of spectrum that has been allocated
specifically forCMRS (354MHz)49orthetotalamountof licensedspectrumtheoreticallyavailable
47ReportITURM.2078,http://www.itu.int/publ/RREPM.20782006/en.
48 Cellular, broadband PCS, and SMR currently in use. AWS1 spectrum is subject to clearing and relocation of
incumbentgovernmentusersand700MHzspectrumissubjecttotheDTVtransition.
49Comprisingthecellular,broadbandPCS,SMR,AWS1,and700MHzbands.
http://www.itu.int/publ/R-REP-M.2078-2006/enhttp://www.itu.int/publ/R-REP-M.2078-2006/enhttp://www.itu.int/publ/R-REP-M.2078-2006/enhttp://www.itu.int/publ/R-REP-M.2078-2006/enhttp://www.itu.int/publ/R-REP-M.2078-2006/enhttp://www.itu.int/publ/R-REP-M.2078-2006/enhttp://www.itu.int/publ/R-REP-M.2078-2006/enhttp://www.itu.int/publ/R-REP-M.2078-2006/en8/13/2019 2008 12 Rysavy Spectrum Demand
24/24
24MobileBroadbandSpectrumDemand
for mobile services (approximately 680 MHz)50, that figure still falls well short of the spectrum
neededtosatisfyprojecteddemand.
The ITU report has been endorsed and referenced by the organization Next Generation Mobile
Networks, in their white report Spectrum Requirements for the Next Generation of Mobile
Networks,June2007,states,Therefore,sufficientnetworkcapacity isamusttosatisfytheend
userexpectationsintermsofservicequality,namelythroughputandlatency.
5 ConclusionWidespread use of mobile broadband technology will not only support a thriving industry, but it will
increaseoverallbroadbandpenetration,which showsa strongpositivecorrelationwith thecountrys
economicwelfare.Forexample,onestudydoneacrossmultiplecountriesshowsacorrelationinwhich
every1%increaseinbroadbandpenetrationcorrespondsto$2,000percapitahigherGDP.51
This report hasdemonstrated that the capacityof mobile networks based oncurrentlyallocatedand
available licensed spectrum is finite and exhaustible based on current and expected broadband and
Internetusageandinnovationtrends.
There are a number of market factors that are acting together to increase spectrum demand at an
acceleratingpace includingevermoremobile life andworkstyles,greaterdevicesophistication,new
bandwidthconsumingapplications,an increasingpercentageofmobileuserstakingadvantageofdata
applications,andongoingindustryinnovation.Furthermore,formobilebroadbandnetworkstoprovide
acrediblealternativeandcomplementtowirelinenetworks,theymustbeabletomaintainpacewith
respecttoperformanceandcapacity.Mobilebroadbandnetworkscanonlymeettheseneedswiththe
timelyadditionofnewspectrum.Giventhelongtimeframesinvolvedingoingfromplanningtoauctiontodeployment,asexperiencedwith theAWSand700MHzbands,planning fornewspectrumshould
beginas
soon
as
possible.
50 This figure includes 50 MHz of cellular spectrum, 24 MHz in the SMR bands, 120 MHz of broadband PCS
spectrum,90MHz intheAWS1band,70MHz in the700MHzbands,195MHz intheBRSandEBSbands,and
132.425MHzinofMSSATCspectrum.
51TrendsinAccessibilityofServicesandNetworks,P.Tournassoud,
http://www.alcatel lucent.com/enrich/v2i12008/article_c1a5.html.
http://www.alcatel-lucent.com/enrich/v2i12008/article_c1a5.htmlhttp://www.alcatel-lucent.com/enrich/v2i12008/article_c1a5.htmlhttp://www.alcatel-lucent.com/enrich/v2i12008/article_c1a5.htmlhttp://www.alcatel-lucent.com/enrich/v2i12008/article_c1a5.htmlRecommended