mobisys12_presentationrrc state meachine

7/29/2019 Mobisys12_presentationRRC STATE MEACHINE

1/53

ACloseExamina.onofPerformanceand

PowerCharacteris.csof4GLTENetworks

JunxianHuang1FengQian1AlexandreGerber2

ZMorleyMao1SubhabrataSen2OliverSpatscheck2

1UniversityofMichigan 2AT&TLabs-Research

June 27 2012


2/53

LTEisnew,requiresexplora.on

4GLTE(LongTermEvolu/on)isfuturetrend Ini.atedby3GPPin2004

100MbpsDL,50MbpsUL,


3/53

LTEstatemachine LTEpowermodel

Networkperformance

Parameterconfigura.on

Energyefficiency

Mobileapplica.on


4/53

RRCstatetransi.onsinLTE

ContinuousReception

ShortDRX

RRC_CONNECTED RRC_IDLE

LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti


5/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

RRC_IDLE

Noradioresourceallocated Lowpowerstate:1136mW

averagepower

Promo.ondelayfromRRC_IDLEtoRRC_CONNECTED:260ms


6/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

RRC_CONNECTED

Radioresourceallocated Powerstateisafunc.onof

datarate:

1060mWisthebasepowerconsump.on

Upto3300mWtransmingatfullspeed


7/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

Con/nuous

Recep/onSend/receiveapacket

PromotetoRRC_CONNECTED

ResetTtail


8/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

TtailstopsDemotetoRRC_IDLE

DRX

Ttailexp

ires


9/53

TradeoffsofTtailsengs

Ttailseng EnergyConsump/on

#ofstatetransi/ons

Responsiveness

Long High Small Fast

Short Low Large Slow


10/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

DRX:Discon/nuousRecep/on

Listenstodownlinkchannelperiodicallyforashortdura.onandsleepsfortherest.metosaveenergy

atthecostofresponsiveness


11/53

Discon.nuousRecep.on(DRX):

micro-sleepsforenergysaving

InLTE4G,DRXmakesUEmicro-sleepperiodicallyintheRRC_CONNECTEDstate

ShortDRX LongDRX

DRXincurstradeoffsbetweenenergyusageandlatency

ShortDRXsleeplessandrespondfaster

LongDRXsleepmoreandrespondslower Incontrast,inUMTS3G,UEisalwayslisteningtothedownlinkcontrolchannelinthedatatransmissionstates


12/53

DRXinLTE

ShortDRXcycle

ContinuousReception

On Duration

Long DRX

cycle

Data transfer Ti expires

Tis expires

Long DRX

cycle

Ti starts Tis starts

ADRXcycleconsistsof OnDura.on-UEmonitorsthedownlinkcontrolchannel(PDCCH) OffDura.on-skiprecep.onofdownlinkchannel

Ti:Con.nuousrecep.oninac.vity.mer WhentostartShortDRX

Tis:ShortDRXinac.vity.mer WhentostartLongDRX


13/53


Networkperformance


Energyefficiency

Mobileapplica.on


14/53

PowertraceofRRCstatetransi.ons

0

1000

2000

3000

4000

0 t1t2 5 10 t3 15 20 t4 25

Power

(mW)

Time (second)

t1: Promotion starts

t2: Data transfer starts

t3: Tail starts

t4: Tail ends

ThedatapointsaresampledandDRXinRRC_CONNECTEDtail

isnotobviousduetothelowsamplingrate


15/53

LTEpowermodel MeasuredwithaLTEphoneandMonsoonpowermeter,averagedwithrepeatedsamples


16/53



17/53



18/53



19/53


P(on)P(off)=620mW,DRXsaves36%energyinRRC_CONNECTED

HighpowerlevelsinbothOnandOffdura/onsintheDRXcycleofRRC_CONNECTED


20/53

LTEconsumesmoreinstantpower

than3G/WiFiinthehigh-powertail

AveragepowerforWiFitail120mW

Averagepowerfor3Gtail800mW

AveragepowerforLTEtail1080mW


21/53

Powermodelfordatatransfer

Alinearmodelisusedtoquan.fyinstantpowerlevel:DownlinkthroughputtdMbps

UplinkthroughputtuMbps


22/53

Energyperbitcomparison

LTEshighthroughputcompensatesforthepromo.onenergyandtailenergy

TransferSize

LTEJbit

WiFiJbit

3GJbit

10KB 170 6 100

10MB 0.3 01 4Totalenergyperbitfordownlinkbulkdatatransfer


23/53


LTEshighthroughputcompensatesforthepromo.onenergyandtailenergy

TransferSize

LTEJbit

WiFiJbit

3GJbit

10KB 170 6 100

10MB 0.3 01 4Totalenergyperbitfordownlinkbulkdatatransfer

Smalldatatransfer,LTEwastesenergy

Largedatatransfer,LTEisenergyefficient


24/53


Networkperformance


Energyefficiency

Mobileapplica.on


25/53

Networkcharacteris.cs 4GTestonAndroid

h>p://mobiperf.com/4g.htmlMeasuresnetworkperformancewiththehelpof

46M-Labnodesacrosstheworld

3,300usersand14,000runsin2months10/15/2011~12/15/2011

20

25

30

35

40

45

50

-130 -120 -110 -100 -90 -80 -70

Latitude

Longitude

WiFiWiMAX

LTE

4GTestusercoverageintheUS


26/53

Downlinkthroughput

LTEmedianis13Mbps,upto30MbpsTheLTEnetworkisrela.velyunloaded

WiFi,WiMAX


27/53

Uplinkthroughput

LTEmedianis5.6Mbps,upto20Mbps WiFi,WiMAX


28/53

RTT

LTEmedian70ms WiFisimilartoLTE WiMAXhigher

0

5

10

15

20

25

30

WiFi LTE WiMAX eHRPD EVDO_A 1

Y1:Networkth

roughput(Mbps)


29/53


Networkperformance


Energyefficiency

Mobileapplica.on


30/53

Usertracebasedanalysis

UMICHdatasetCollectedfrom20volunteersmartphoneusersfor

fivemonths,totaling118GB

Containspackettracesincludingfullpayload Trace-drivenmodelingmethodology

Networkmodelsimulator Simulatesnetworkstates,suchasRRCstatetransi.ons

Powermodelsimulator Calculatespowerusagebasedonthenetworkstates


31/53

Comparingtotalenergyofalluser

tracesviasimula.oninLTE/3G/WiFi

TotalenergyusageLTE/WiFi233G/WiFi15

0

5

10

15

20

25

30

All 1 2 3 4 5 6

E

nergy

ratio

User ID

Energy ratio: LTE/WiFiEnergy ratio: 3G/WiFi


32/53

Energyconsump.onbreakdown

TailenergydominatesLTEenergyconsump.on,similarto3G

0

20

40

60

80

100

All 1 2 3 4 5 6

%

oftotalenergy

User ID

LTE

WiFi

3G

% Idle energy% Tail energy

% Promotion energy

% Data transfer energy

Thetotalenergyfordifferentnetworksandusersisnormalizedtobe100%


33/53

Energyconsump.onbreakdown

TailenergydominatesLTEenergyconsump.on,similarto3G

0

20

40

60

80

100

All 1 2 3 4 5 6

%

oftotalenergy

User ID

LTE

WiFi

3G

% Idle energy% Tail energy

% Promotion energy

% Data transfer energy

Thetotalenergyfordifferentnetworksandusersisnormalizedtobe100%

Thetailproblemisthekeyfactorfor

LTEshighenergyconsump.on,

similarto3Gnetworks


34/53


Networkperformance


Energyefficiency

Mobileapplica.on

f fi l ( )


35/53

ImpactofconfiguringLTEtail.mer(Ttail)

Sisdefinedtobethenumberofpromo.ons TtailhassignificantimpactonradioenergyE,channelschedulingdelayD,andsignaling

overheadS

-0.50

0.5

1

1.5

0 5 TD 15 20 25 30

(relative

change

)

Ttail (second)

EDS

TDisthedefaultsengforTtailinthemeasurednetwork


36/53


Networkperformance


Energyefficiency

Mobileapplica.on


37/53

Appcasestudy

Studied5web-basedapps LTEhascomparablepageloading.measWiFi,with3Glaggingbehind

CPUusageforLTE/WiFiisbetween80%~90%duringpageloading

Networkdoesnotappeartobethebo\leneck

Totalenergyconsump.on:LTE>3G>>WiFi


38/53

Appcasestudy

Studied5web-basedapps LTEhascomparablepageloading.measWiFi,with3Glaggingbehind

CPUusageforLTE/WiFiisbetween80%~90%duringpageloading

Networkdoesnotappeartobethebo\leneck

Totalenergyconsump.on:LTE>3G>>WiFi

InLTEnetwork,applica.ons

shouldmoreaggressivelybursttraffictomakemoreefficient

useofthebandwidthgiventhe

highenergyoverhead


39/53

Summary

LTEhassignificantlyhigherspeed,comparedto3GandWiFi LTEismuchlesspowerefficientthanWiFiduetoitstailenergyforsmalldatatransfers

DerivedapowermodelofacommercialLTEnetwork,withlessthan6%errorrate

UEprocessingisthebo\leneckforweb-basedapplica.onsinLTEnetworks MobileappdesignshouldbeLTEfriendly


40/53

Thankyou!

Q&A

Contact:JunxianHuang(hjx@umichedu)


41/53

Backupslides


42/53

PowertraceofDRXinRRC_CONNECTED

800

1000

1200

1400

1600

1800

2000

0 50 100 150 200

Power(mW)

Time (ms)


43/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

Con/nuous

Recep/on

Sendreceive

apacket

ResetTi


44/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

Short

DRX

Tistops,Tisstarts


45/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

Con/nuous

Recep/on

ResetTi,stopsTis


46/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

Long

DRX

Tisstops

Tis

expires


47/53


ContinuousReception

ShortDRX


LongDRX

DRX

Timerexpiration

Datatransfer

Ttail

Tis

Ti

ResetTi

Con/nuous

Recep/on

Impact of DRX inac.vity .mer (Ti):


48/53

ImpactofDRXinac.vity.mer(Ti):

Con.nuousrecep.ontoshortDRX

Differently,Sisdefinedasthesumofthecon.nuousrecep.on.meandDRXondura.onsinRRC_CONNECTED

TihasnegligibleimpactonE,however,Sissignificantlyaffected

-0.5

00.5

1

1.5

22.5

0 TD200 400 600 800 1000

(relative

change)

Ti(ms)

EDS


49/53

Interes.ngques.onsaboutLTE

Tousers:whatistheendperformance?Networkperformance,suchasRTTandthroughput,

howitcompareswithWiFi,3GandWiMAX,etc

Energyefficiencyaffec.ngba\erylife,isLTEmorepowerefficientthan3GorWiFi?

ToISPs:whatistheimpactofconfiguringLTE-relatedparametersonUEpowersaving,anddelay/signalingoverhead?

ToOS/applica.ondevelopers:whatistheperformancebo\leneckofapplica.onsinLTEnetwork,CPUornetworkspeed?


50/53


Forlargedatatransferwithmaximumrate,LTEsenergyefficiencyiscomparablewith

WiFi,duetoLTEshighdownlinkthroughput

0

20

40

60

80

100

120

140

160

180

10 100 1000 10000

J

/bit

Bulk data size (kB)

LTE DOWNLTE UP

WiFi DOWNWiFi UP

3G DOWN3G UP

One way delay and impact of packet size


51/53

Onewaydelayandimpactofpacketsize

(notquiterelated)

LTEuplinkonewaydelay(OWD)islargerthanthatofdownlink

RTTinLTEismoresensi.vetopacketsizethanWiFi,mainlyduetouplinkOWD

0

20

40

60

80

100

0 200 400 600 800 1000 1200 1400

Dela

y(ms)

Packet size without TCP/IP headers (byte)

UP OWDDOWN OWD

RTT

JavaScript execu.on speed: a representa.ve


52/53

JavaScriptexecu.onspeed:arepresenta.ve

viewofsmartphoneprocessingcapability

From2009to2011,smartphoneshavesignificantlyimprovedJavaScriptexecu.onspeed

Samsung/IEWindows Mobile 6.5

iPhone/SafariiOS 3.0

G1/DefaultAndroid 1.6

G1/DefaultAndroid 1.6

Samsung/IEWindows Phone 7.5

HTC/DefaultAndroid 2.2.1

iPhone 4/SafariiOS 5.0.1

iPhone 4S/Safari

iOS 5.0.1

Laptop/ChromeMac OS X 10.7.2

0 50 100 150 200 250

Time to finish JavaScript benchmark (sec)

0.41s

2.26s

3.93s

4.42s

9.46s

95.08s

95.66s

117.41s

210.97s

Tested in Nov, 2009Tested in Nov, 2011


53/53

Powermodelfordatatransfer

Alinearmodelisusedtoquan.fyinstantpowerlevel:

Uplink/downlinkthroughputtu/td(Mbps)

mobisys12_presentationrrc state meachine

Documents