Charting the Course forMobile Broadband:

Heading Towards High-Performance All-IP with LTE/SAE

Nokia Siemens Networks expectsfive billion people to be connected tothe web by 2015. Wireless access tothe Internet will be in step with wirelineaccess. Access via mobile phonesupporting enhanced data applicationswill complement notebook basedusage. Wireless networks will beused to extend broadband penetrationbeyond the reach of wireline networks.More and more user communitieswill enjoy multimedia services, drivingtotal bandwidth demand. This affordsmobile network operators a businessopportunity they can capitalize on byimproving their networks’ performanceand efficiency.

With a view to taking the next stepup the evolutionary ladder beyondHSPA, 3GPP Rel8 has standardizeda technology called Long TermEvolution/System Architecture Evolution (LTE/SAE). It is designed to

• Make the most of scarce spectrumresources: Deployable in pairedspectrum allocations with bandwidthsranging from 1.4 MHz to 20 MHz,LTE/SAE provides up to four timesthe spectral efficiency of HSDPARelease 6

• Afford users an experience onpar with today’s best residentialbroadband access: LTE/SAEdelivers peak user data ratesranging up to 173 Mbps andreduces latency to as low as 10 ms

• Leverage flat all-IP networkarchitecture and a new air interfaceto significantly cut per-Mbyte costs,with later product innovationspotentially improving performanceeven further:For instance a 4x4 Multiple Input/Multiple Output (MIMO) schemewill boost downlink rates up to 326 Mbps

Nokia Siemens Networks takes acost-effective approach to introducingLTE/SAE, enabling GSM-/WCDMA-,CDMA-, and greenfield networkoperators to grow their business andmargins in the fast-approaching eraof ubiquitous mobile broadband.

Contents

02 Executive Summary

03 Background

03 Market drivers and expectations

05 User benefits

06 Operator expectations

08 System approach

09 Optimizing total value of ownershipwith Nokia Siemens Networks`LTE/SAE

12 Conclusions

13 Abbreviations

02/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

ExecutiveSummary

Market driversand expectations

03/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

Video streaming

< 64

kb/s

Ban

dw

idth

Audio/videodownload

Mobileoffice/e-mail

MMS, web-browsing

1 M

b/s

> 5

Mb

/s

FTP

Voice mail

SMS

> 1 sec 200 ms 100 ms 20 ms

Video telephonyAudio streaming

Voice telephony

Multiplayer games Interactiveremotegames

m2m: remote control

Video conferencing Real-timegamingm2m:

robot security;video broadcast

NetworkLatency

Source: IST-2003-507581 WINNER, D1.3 version 1.0, Final usage scenarios. 30/06/2005;„Parameters for Tele-traffic Characterization in enhanced UMTS2“, University of Beira, Portugal, 2003

Growth drivers

a promising business opportunity fornetwork operators, who respondedby launching HSDPA and flat ratesin 2006, attracting many businessusers. And while this user segmentmay be small compared to the hugeconsumer market, overall mobile datatraffic grew tenfold in many networks.

Mobile broadband users will expectservices, data rates, VoIP andmultimedia capabilities similar tothose enjoyed by fixed broadbandusers today, at affordable prices.This is why NGMN Ltd., a group ofglobally active mobile operatorsdetermined to match DSL offerings’performance and cost, has raisedthe bar for the next generation ofmobile networks (NGMN). Seekingto satisfy these demands, Nokia

The Internet has changed manypeople’s lives in the last decade.Services delivered across the webnow supplant many offline processes.The Internet has become a majordelivery platform for text, music, video,and the like. All this has spurredbroadband’s growth. With broadbandadoption outpacing cellular voice,Nokia Siemens Networks predictsthat five billion people will enjoyInternet access by 2015. What’smore, broadband is tracing mobiletelephony’s trajectory, becoming awidespread service to be enjoyed bythe user anywhere, anytime.

More and more people are embracingmobile broadband and enjoyingdata-heavy video content. Thiscoincidental development presents

Figure 1: Latency and bandwidth requirements for various services

Background

Evolving user servicesNew services will center on data andmultimedia communication alongsideor within the context of voice.

Figure 1 shows some of these services and their typical bandwidthand network latency requirements.Services expected to become majorgrowth drivers are highlighted. Whilevoice remains the most popularapplication for large user segments,several distinct trends will influencemobile communications in the yearsahead:

• Common, access-independentInternet applications will replacesilos for mobile applications andresidential applications

Siemens Networks and its parentcompanies participated in the LongTerm Evolution (LTE) and SystemArchitecture Evolution (SAE) studiesconducted by the Third GenerationPartnership Project (3GPP).LTE/SAE aims to improve performanceand cost-efficiency with a more efficient air interface, more flexible useof radio spectrum, and flat, packet-based network architecture. The ultimate goal is to enable wirelessbroadband communication commensurate with DSL in fixed networks.

The study phase of 3GPP work onLTE and SAE ended in mid-2006,transitioning to the specification phasefor the new radio access system (LTE)and the packet-based core network(SAE). 3GPP intends to completethe first set of specifications in thefirst half of 2008, enabling initialimplementation in 2009.

04/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

• Web2.0 applications empowerusers to participate in communities,and will generate content andinteract in virtual worlds

• Streaming services that deliverindividual video content on demandand mobile TV on demand areemerging as a favored application

• Mobile, interactive remote gamingand real-time gaming will undoubtedly become a majorindustry in its own right

• The quadruple play of voice,data, video and mobility bundlesfor residential and mobile use isheating up the battle overfixed-mobile substitution in theconsumer market

• Mobile office comprising smartphones, notebooks, ubiquitousbroadband access and advancedsecurity solutions will free businessusers from their office desk.

The key enabler for these trends to materialize in mobile communications is user gratification,which will depend on:

• The network’s capacity to supporthigh peak user data rates and highaverage data throughput rates

• Low user data plane’s and signallingchannels’ response time, or latency

• Guaranteed radio coverageensuring full use of servicesup to the cell’s edge

• A viable means of creating andmaintaining individual connectionsand the entire system’s quality ofservice (QoS)

• Service continuity between accessnetworks

• Single sign-on to all network access• Competitive prices, with many

users favoring flat-rate fees for reasons of cost control

As users discover personal mobileservices on par with household-centricservices, they are sure to takeadvantage of mobile operators’ greatstrength – mobility. The key is tosatisfy users’ expectations of accesswhenever and wherever they want it.

Rising traffic, falling tariffsOverall traffic (voice and data) inmobile networks is expected to growfast. Data traffic in some EuropeanHSPA networks is edging towardsexponential growth, with projectionsthat half of overall network capacitywill soon be devoted to satisfyinguser demand. Analysts predict averageprice per MB will decline as voiceand non-voice services drive trafficgrowth. A strong trend towards flat-ratepricing is already sweeping the market.Data and multimedia service offeringswith attractive service packagesand flat rates are key businessdifferentiators. Voice services, in turn,are fast becoming a commodity, andprice pressure is bound to rise. Thiscompels operators to respond byoffering voice service at low costwith acceptable QoS, for example,by migrating it to packet-based VoIP.And as flat rates become morepopular, operators will have to cut theper MB cost of sending data acrossthe network. Fair usage policies needto be applied in order to preventbandwidth-greedy peer-to-peerapplications, especially file sharing,from overloading the network.

Upgrading to HSPA reduces thetypical cost per MB of deliveringdata across a WCDMA network bymore than 50%. LTE/SAE is likelyto trim another 70% from this cost,enabling operators to offer up to tentimes as much data at a similar costto today’s WCDMA (Source: AnalysisResearch/Nokia Siemens Networks).

Advances in technologyOptimizing digital signal processingalgorithms and advances in antennatechnologies will push the air interface’s spectral efficiency evercloser to its theoretical limits.

Improved IP transport (pervasiveGbit Ethernet) and QoS assurancetechnologies boost packet-centricnetworks’ data and voice performance,efficiency and carrier-grade reliability.All this, in combination with advancesin IP-centric equipment and VoIPtechniques, will make the all-IPvision a reality. LTE/SAE enablesoperators to implement all serviceson a single IP-centric, purely packetbased network. This will make IPapplications as genuinely mobile asvoice is in today’s mobile networks.These advances, alongside a simplified architecture, will also drivedown operational expenditures and,by extension, lifecycle costs.

User benefits

05/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

min. max.

Downlink Uplink

Max. peak data rate **

spectral efficiency Downlink spectral efficiency Uplinkcell throughput (5MHz cell)cell throughput (5MHz cell) Uplink

Spectral efficiency / Average cell throughput (Macro cell) **

Latency (Roundtrip ping delay) *

LTE

HSPA+ (rel 8)

GSM/EDGE

0

HSPA R6

20 40 60 80 100 120 160 200 ms

HSPA R6 LTE2x20 MHz(2x2 MIMO)

HSPA+(Rel. 7/8,2x2 MIMO)

LTE2x10 MHz(2x2 MIMO)

LTE2x20 MHz(4x4 MIMO and64 QAM UL)

HSPA R6 LTE(4x4 MIMO)

HSPA Rel8 LTE(2x2 MIMO)

0

2

2.5

1

0.5

1.5

bps/

Hz/

cell

3

0

100

300

350

200

50

150

250

Mbp

s

DSL (~ 20..50 ms, depending on operator)

0

8

10

4

2

6

16

12

14

180140

* Server near RAN

Downlink Uplink

VoIP capacity **

HSPA R6

0

20

60

70

40

10

30

50

Cal

ls/M

Hz/

cell

LTE

** LTE values acc. to 3GPP R1-072580 case 1(macro cell, full buffer, 500m ISD)

Mbp

s/ce

ll (5

MH

z ce

ll)

Figure 2: Comparison of throughput (maximum, typical) and latency

While many consumers have noparticular interest in technology, they do expect unimpeded accessto the Internet and personalizedservices, at anytime and in anyplace.

Today’s residential broadband accessshapes consumers’ expectations ofInternet access and their perceptionsof network performance.

This perceived network performance,in turn, is formed by a blend of thepeak user data rate, average userthroughput, cell throughput, signalingdelays, and user data latency. Oneof the keys to differentiating mobileofferings is boosting perceived mobilebroadband performance.

Figure 2 compares LTE/SAE’s peakdata rates, average cell throughput,VoIP capacity and latency with earlierWCDMA/HSPA releases. On thephysical layer, LTE/SAE with 2x2MIMO delivers peak downlink datarates ranging up to about 173 Mbps,and even 326 Mpbs with 4x4 MIMO.Coexistence, interoperability, roaming,and handover between LTE/SAEand existing 2G / 3G networks andservices are inherent design goals,so full mobility support is given fromday one.

The user benefits outlined abovetranslate into revenue potential forthe operator. To tap this potential andturn profits, operators must optimizeboth revenues and costs. And theneed to improve cost efficiencyincreases as data traffic rises andper-MB prices drop.

Figure 3 shows the relationshipbetween network performance andcost for WCDMA/HSPA and LTE.LTE/SAE combines a more efficientair interface, a simplified network,and improved service provisioningto achieve greater cost efficiencyand savings.

Air interface performance andflexibilityDriving down cost per MB entailsimproving the air interface’s efficiencyand applicability by:

• Increasing spectrum efficiencyand cell edge bit rates, and flexiblyallocating bandwidth by makingthe most of available spectrum.

• Operating in the 3G spectrum – ifnecessary, alongside a 3G system– and in soon-to-be assigned newspectrum.

06/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

• Gearing up to re-farm frequencybands such as GSM and possiblyoperating in lower frequencybands to exploit spectrum optionsand to maximize coverage at lowerinvestment, especially in rural areaswith lower traffic density. Re-farmingGSM and CDMA requires a solutionsuitable for small bandwidthallocations.

• Supporting fast service accessto minimize system load and maximize the number of simultaneously served users.

Network complexityThe consensus is that the complexityof system architectures and diversityof protocols are major cost driversfor networks and terminals. Thiscomplexity and diversity can bemastered by:

• Simplifying the network architecturewith a flat hierarchy and muchfewer protocol conversions (or content mappings).

• Introducing open, streamlinedinterfaces and reducing protocoloptions.

• Employing IP-centric communication,equipment and VoIP throughoutthe core and radio networks.

• Extensively employing low-costbackhauling such as carrier-gradeEthernet rather than E1/T1 basedleased lines.

• Supporting self-configuringand self-optimizing networktechnologies to reduce installationand management costs.

Service provisioningRecent surveys indicate that userexpectations are difficult to predictover the long term. In reality, analystsexpect services to become a short-term business offering. This meansoperators need to consider:

• The means to create highlypersonalized services and deliverevery type of service, includingend-user self-provisioning

• Individual support for every type ofaccess based on a common servicecontrol and provisioning platform

• An improved user experience forevery service offering

• Diversified offerings, includingflexible service bundling acrossall breeds of access

• Simple and transparent billing procedures which foster subscriberloyalty.

Interworking with and migrationfrom non-3GPP radio accesssystemsOperators of non-3GPP radioaccess systems, like CDMA, expectan easy evolution of their networksto LTE/SAE, in order to benefit fromthe scale of the 3GPP ecosystem.3GPP acknowledged this need byspecifying an improved interworkingbetween LTE/SAE and non-3GPPradio access systems. In particular,the standard supports seamlessmobility and handover between LTEand CDMA2000.

Operator expectations

Superior User Experience Competitive Network Cost

HSPA LTE HSPA LTE

Peak throughput Latency

Factor 10 Factor 2-3

UMTS HSPA LTE

Cost per MByte

~ 50%

> 70%

I-HSPA

1 2

Figure 3: Key building blocks of operator success

07/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

In light of the efforts to standardizeLTE/SAE underway, 3GPP is definingthe air interface, network architecture,and system interfaces. All serviceswill be packet-based; that is, VoIPwill serve to implement voice.Figure 4 shows an LTE/SAEnetwork’s high-level architecture.3GPP envisages fully IP-basedtransmission. LTE/SAE will not entaila circuit-switched domain, and theIP backbone network will supportguaranteed QoS on demand witha very simplified, but backwardcompatible QoS concept. The goal isto use carrier-grade Ethernet wherepossible; in particular to connect theeNode B, the LTE’s base station.

Simplified network architectureToday’s WCDMA core networkarchitecture for the PS domaincomprises SGSN and GGSN.The radio network architecturecomprises NodeB and RNC.

LTE/SAE architecture is streamlinedto optimize network performance,maximize data throughput, andminimize latency. Rather than fournodes (Node B, RNC, SGSN, GGSN),LTE architecture will comprise a farsimpler configuration of just eNode Band the Access Gateway (aGW).The aGW consists of two logical userplane entities, Serving Gateway andPDN Gateway, collectively called theSAE GW, and one control plane entity(MME). These may be implementedin common or separate physicalnodes, with standardized interfacesbetween them to support multi-vendorconfigurations.

eNode B and the MME perform thecontrol functions, while eNode Bhandles the user plane, partly withthe Serving Gateway and partly withthe PDN Gateway. Transport is fullyIP-based. Because the accessnetwork operates without a centralcontroller (BSC, RNC), base stations(eNode B) interconnect and connectto the aGW to exchange controland user information directly. Thisapproach entails fewer interfacesand minimal complexity caused byprotocol conversion and contentmapping.

Access Core Switching & Transport

Service Control and Data Bases

eNode B

IMS PCRF HSS/AAA

Serving GW PDN (HA)

SAE GW

MME

aGW

Internet

Figure 4: LTE/SAE target architecture

Systemapproach

High-performance air interfaceThe LTE air interface will differmarkedly from legacy technology.Advanced applied OrthogonalFrequency Division Multiplexing(OFDM) technologies achieve performance and savings goals based on low total cost of ownership.

Figure 5 summarizes the technologicalapproach to the projected airinterface. Many orthogonal OFDMsub-carriers may be allocatedaccording to carrier bandwidthavailable in the downlink. The uplinkemploys a single carrier FDMAtechnology (SC-FDMA) to precludehigh peak-to-average power ratios,thereby streamlining the RF designand extending the battery life of theterminals.

Coordinated interference cancellation,MIMO antenna technology and higherorder modulation (up to 64 QAM),combined with fast link adaptationmethods, maximize spectral efficiency.

In principle, operators need notacquire new spectrum. The LTE airinterface is designed to operate inthe same spectrum as and in parallelwith the legacy WCDMA/HSPA airinterface, for example on a separatecarrier. The system’s flexible spectrumallocation (including scalablebandwidth) allows carriers to bespread across any suitable spectrumlicensed for 2G or 3G operation.

Deployable in spectrum bands withbandwidths of 1.4, 3, 5, 10, 15, and20 MHz, LTE offers unique spectrumflexibility. The small 1.4 and 3.0 MHzbandwidths are optimized for GSMand CDMA re-farming, where operatorsmight not initially be able to free upmore bandwidth.

Figure 5: LTE air interface technology

Available bandwidth

...

FrequencyOFDMsymbols

Sub-carriers

...Guardintervals

Time

∑

08/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

09/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

• Combined 2G/3G networksenabling smooth migration from 2Gto 3G and ensuring cost-efficientoperations.

• The SGSN and GGSN for thepacket core, which today canhandle both 2G and 3G traffic.

Nokia Siemens Networks is knownfor its experience in masteringcomplex ecosystems, with a recordof achievement that includes:

• The industry’s first FMC solutiondelivered successfully to themarket.

• Integrating various accesstechnologies to enable commonservice provisioning.

• The Nokia Siemens Networks`network management system anda comprehensive set of operatorservices. This is an integratedmanagement system withfeature-rich functionality for all 2Gand 3G elements (BSS, RAN,core, transmission and so forth).

For many years, Nokia SiemensNetworks and its parent companieshave driven radio access andnetwork technology innovation by:

• Participating in internationalresearch programs

• Pursuing many joint researchactivities in these areas with diverseindustry and academic partners

• Driving 3GPP’s efforts tostandardize LTE/SAE

The world’s first live demonstrationsof the LTE air interface’s capabilitiesat the 3G World Congress in HongKong in December 2006 and 3GSMWorld Congress in Barcelona inFebruary 2007 underscore NokiaSiemens Networks’ leadership inLTE/SAE. This demonstrator (seeFigure 6) served to send High Definition Television (HDTV) videoover an air interface based on thepreliminary LTE specifications andhand over in real time to an HSPDAair interface. MIMO enabled a downlinkpeak data rate of 160 Mbps. A roundtripdelay of about 10 ms has beendemonstrated.

LTE/SAE will provide a mobilemultimedia network that deliversbroadband wireless services withfixed-line quality and the costefficiency of IP technologies. NokiaSiemens Networks leverages leadingarchitectural and systems expertiseto allow operators to seamlesslyevolve their networks to LTE/SAE.

Nokia Siemens Networks has ampleexperience in implementing andupgrading complex systemarchitectures. The company iscommitted to enabling smoothmigration, and is preparing itsproducts to accommodate LTE/SAEtechnology. The track record of NokiaSiemens Networks in efficient systemmigration includes:

• Easy introduction of EDGE without system downtime.

• HSPA (HSDPA and HSUPA), wherea software download upgrades theentire installed base.

Video applicationIMS client

Multimode UE

MIMO

Access

IPv6

luBIPv6

eNode B

HSPANode B

Core

IMS(control node and AS)

Access Gateway(packet core)

Services

Video application(IMS-controlledvideo supervision)

Video application(Real-time videostreaming – HDTV)

Figure 6: Nokia Siemens Networks` LTE demonstrator: First live NGMN air interface – with applications and interworking with legacy 3G system – service continuity in one equipment

Optimizing total value of ownershipwith Nokia Siemens

Networks’ LTE/SAE

10/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

Furthermore, Nokia SiemensNetworks initiated together with Nokiaand six other vendors and operatorsthe so-called LTE-SAE Trial Initiative(LSTI). The goal is to demonstratethe capabilities of LTE/SAE byperforming a series of tests includingradio transmission performance tests,early interoperability tests, field testsand full customer trials. By givingearly feedback about the LTE-SAEperformance and interoperability tostandardization and industry, the timefor commercial product availability isexpected to be significantly reduced.In the meantime, further operators,terminal- and chipset vendors havejoined the group, which is open toany organisation that is committedto actively contributing to the abovegoals.

LSTI reached its first milestone inOctober 2007 and confirmed thatthe LTE physical layer performancetargets in terms of stationary andon-the-move peak data rates can bemet. This confirmation was achievedusing an agreed set of commontransmission profiles, test proceduresand analysis methods. The tests wereperformed using prototype singleand multi-antenna radio systems inboth lab and urban field environments.

Nokia Siemens Networksdemonstrated during outdoor testswith a 2x2 MIMO antenna system alayer 1 peak data rate close to 173Mbps in DL and 58 Mbps in UL andsuggested that these values will bereached with the final agreement onlayer 1 implementations.

GSM/(E)GPRS

WCDMA/HSPA

I-HSPALeverage existing handset base

LTE R8

Enabling flat broadband architecture

CDMAGreenfield

Figure 7: The architectural evolution of legacy 2G/3G networks to LTE

An operator’s strategy for gaining thecompetitive edge in mobile broadbandbuilds on three fundamental insights:

• The key to sustaining fast subscribergrowth is being part of a large ecosystem that accommodates manydifferent – as well as the latest – user devices, as is evident fromthe recent churn from CDMA to GSMnetworks. GSM/WCDMA is by farthe largest mobile communicationsecosystem worldwide.

• Once traffic attains critical volume,there is only one way to achievecost-efficient scale network capacity– via flat network architecture.Until now, fixed broadband networksprovided the blueprint; now I-HSPA(Internet-HSPA) introduces flatarchitecture to cellular networks.

• Ubiquitous mobile broadbanddemands optimum use of scarcespectrum resources, cost-efficientnetworks, and high networkperformance as perceived by users.

Nokia Siemens Networks is committedto providing a smooth evolutionarypath for every operator, following aroadmap that factors each operator’sinstalled base and strategy into theequation (see Figure 7).

• 3G operators who have deployedI-HSPA have flat networkarchitecture similar to LTE/SAE inplace, and can thus cost-efficientlyintroduce LTE/SAE.

• 3G operators with a deployedWCDMA/HSPA network can migratedirectly to LTE/SAE. Migrating tothe flat network architecture ofInternet High Speed Packet Access(I-HSPA) may also be beneficialbecause it accommodates LTE/SAE’sflat IP-based network architecturewhile supporting legacy WCDMA/HSPA handsets. The operatorcan thus enjoy the transport andnetwork scaling benefits immediatelyand easily upgrade the network toLTE/SAE later.

• Operators running 2G networks(GSM/GPRS) can introduceLTE/SAE directly or via one ofthe above WCDMA/HSPA paths,depending on their timetables forintroducing mobile broadbandservices and the spectrum theyhave available. Because LTEsupports bands as small as 1.4 MHz,spectrum may be re-farmedsmoothly and gradually from GSM to LTE.

• Greenfield and CDMA operatorscan introduce LTE/SAE networksdirectly or follow one of the abovepaths. GSM/EDGE may bea good choice for strategies moreimmediately focused on voice centric business. Operators optingto take the I-HSPA path cancapitalize on the ecosystem ofHSPA terminals, benefit from theflat architecture today, and quicklyoptimize mobile broadbandperformance.

Nokia Siemens Networks implementsall components of the 2G and 3Gproduct portfolio using innovativetechnologies and future-proofplatforms:

• Nokia Siemens Networks designsinnovative base stations enablingoperators to flexibly upgrade tofuture radio standards while reusinglegacy modules and withoutadding to the footprint. This affordsoperators total investmentprotection. One example is theinnovative BTS platform, designedto support different radio standards.It is modular, with the flexibilityrequired to upgrade a 2G/3G site tosupport LTE. To this end, it sharesLTE-ready equipment in the RFchain – the antenna, the feeder,as well as – given deployment inthe same spectrum – RF modules.Different radio standards supportedat the same site can also sharethe backhaul system. Dedicatedbut identical hardware basebandand control modules serve to runthe different radio standardssmoothly and independently. Allthis minimizes the operator’s spareparts inventory, logistics costs andinstallation efforts.

• PS domain network nodes connectmultiple access technologies andinterfaces to service control anddatabase functions. The SGSNand GGSN will evolve to serve asthe SAE network’s MME and SAEGW. Operators may also installSGSN, GGSN, MME, and SAEGW functions on separate physicalnodes.

• A powerful means of migrating all services, the IP MultimediaSubsystem (IMS), provides common service control.

• The Nokia Siemens Networks`network management systemsupports common operationalprocedures.

These products feature high-performance technologies that configure and adapt flexibly to suitdeployment requirements. They alsobring to the table all the benefits ofreliable carrier-grade systems.

This approach ensures cost-effectivenetwork migration, early systemavailability and stability, and protectsinvestments in the overall LTE/SAEsolution.

The Nokia Siemens Networks’LTE/SAE solution enables operatorsto cost-efficiently introduce and runLTE/SAE:

• No additional site preparationsrequired: Nokia SiemensNetworks’ BTS platforms enableLTE radios to be easily added tolegacy equipment without enlargingthe footprint.

• Flexible approach: If necessary,operators may run LTE alongsideGSM/EDGE, WCDMA/HSPA orother radio access systems suchas CDMA, WLAN or WiMAX (see Figure 8).

• Painless migration: LTE/SAE fullysupports security, roaming, QoS,and similar features.

• Reusable infrastructure: Current2G/3G applications may be usedagain in LTE.

CDMAWiMAXWLAN

(Simplified)

LTE/SAE

GSMWCDMA/HSPAI-HSPA

BS

Node B BTS

PDSNASN-GWePDG

RNCBSC

SGSN GGSN

PSTN

PDN

IMS

HA

AAA

PCFOperator-controlled &public IPservices

HSS/HLR(AAA)

PCRF

MGW

Service Control andData Bases

Core Switching andTransportAccess

aGWeNode B

Figure 8: Architecture evolution of legacy 2G/3G networks to LTE

11/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

12/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

The evolving mobile broadband business opportunity calls for highperformance all-IP mobile broadbandnetworks. The motivations, requirements and the solution based on the LTE/SAE standardhave been discussed.

Several user studies lead to theconclusion that traffic in mobilenetworks will snowball in the yearsahead. The driving forces behindthis growth are:

• Broadband Internet access offeringa DSL-like user experience

• On demand video content and Web2.0 applications

• Fixed voice substitution• Service convergence across

multiple access technologies

While WCDMA/HSPA has madesignificant strides towards efficientmobile data and multimediainformation exchange, LTE/SAEwill provide extended networkperformance and reduced cost perMB that are able to deliver on thepromise of future broadband mobilewireless communications.

LTE/SAE charts a naturalevolutionary course for 2G/3Goperators because it offers:

• Investment protection by reusingsites and network elements to themaximum.

• A superior user experienceenhanced by high throughput andlow latency, offering rich potentialfor subscriber uptake.

• Low cost per MB courtesy of a flat,IP-based network architecture andhigh spectral efficiency, enablingoperators to cost-efficientlyintroduce flat rates.

• Scalable bandwidth ranging from 1.4 up to 20 MHz, enablingoperators to exploit lower and othereconomically-attractive frequencybands where relatively little spectrumis available, achieving nationwidecoverage at far lower costs.

As an industry pacemaker, NokiaSiemens Networks has a clear visionand strategy for implementingLTE/SAE. Geared to reuse as manysystem components as possible,Nokia Siemens Networks’ LTE/SAEsolution will enable early migrationto flat network architecture, optionallywith I-HSPA as an intermediate step.Complying fully with the 3GPP LTE/SAE standard, this high performancemobile broadband network will bereliable and interoperable. By enablingits smooth, early introduction, NokiaSiemens Networks will optimize theLTE/SAE solution’s total value ofownership.

Conclusions

13/14 Network Evolution: Heading a more powerful Mobile Network with LTE/SAE

3GPP Third Generation Partnership ProjectAAA Authentication, Authorization, AccountingaGW Access GatewayAS Application ServerASN Access Service NetworkBS Base StationBSC Base Station ControllerBSS Base Station SubsystemBTS Base Transceiver StationCDMA Code Division Multiple AccessDSL Digital Subscriber LineEDGE Enhanced Data rates for GSM EvolutionEGPRS Enhanced General Packet Radio ServiceeNode B enhanced Node BePDG Evolved Packet Data GatewayFDMA Frequency Division Multiple AccessFMC Fixed Mobile ConvergenceFTP File Transfer ProtocolGGSN Gateway GPRS Service NodeGSM Global System for Mobile CommunicationsHA Home AgentHLR Home Location RegisterHSDPA High-Speed Downlink Packet AccessHSPA High-Speed Packet AccessHSUPA High-Speed Uplink Packet AccessHDTV High-Definition TelevisionHSS Home Subscriber Server I-HSPA Internet High-Speed Packet AccessIMS IP Multimedia SubsystemIP Internet ProtocolISD Inter Site DistanceLTE Long-Term EvolutionLSTI LTE-SAE Trial Initiativem2m Machine-to-MachineMGW Media GatewayMIMO Multiple Input / Multiple OutputMME Mobility Management EntityNGMN Next Generation of Mobile NetworksOFDM Orthogonal Frequency Division

MultiplexingPCF Policy Control FunctionPCRF Policy and Charging Rule FunctionPDN-GW Packet Data Network GatewayPDSN Packet Data Serving Node PS Packet-switchedPSTN Public Switched Telephone NetworkQAM Quadrature Amplitude ModulationQoS Quality of serviceRAN Radio Access NetworkRF Radio FrequencyRNC Radio Network ControllerSAE System Architecture EvolutionSAE GW System Architecture Evolution GatewaySC-FDMA Single Carrier Frequency Multiple AccessSGSN Service GPRS Service NodeSMS Short Message Service

UE User EquipmentUL UplinkUMTS Universal Mobile Telecommunications

SystemVoIP Voice over IPWCDMA Wideband Code Division Multiple AccessWiMAX IEEE 802.16WLAN Wireless Local Area Network

Abbreviations

www.nokiasiemensnetworks.com

AuthorNokia Siemens Networks is a leading global enabler of communications services. The company provides a complete, well-balanced product portfolio of mobile and fixed network infrastructure solutions and addresses the growing demand forservices with 20,000 service professionals worldwide. Nokia Siemens Networks is one of the largest telecommunicationsinfrastructure companies with operations in 150 countries. The company is headquartered in Espoo, Finland.

The contents of this document are copyright © 2007 Nokia Siemens Networks. All rights reserved.

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