WiMAX, making ubiquitoushigh-speed data services a reality

S T R A T E G Y W H I T E P A P E R

Imagine a single wireless technology that can:

• make portable Internet a reality by extending public WLAN

hotspots to metropolitan area coverage for mobile data-centric

service delivery,

• connect enterprises and residential users in urban and suburban

environments where access to copper plant is difficult,

• bridge the digital divide by delivering broadband in low-density

areas.

Thanks to its innovative technology, WiMAX will offer broadband

wireless access at data rates of multiple Mbit/s to the end-user and

within a range of several kilometers. The same radio technology

will also offer high-speed data services to all nomadic terminals

(laptops, PDAs, etc.) with an optimized trade off between

throughput and coverage. Ultimately it will enable the "Portable

Internet" usage replicating on the move the same user experience

as at home or at the office.

Given its huge benefits, WiMAX will develop as a powerful radio

access solution with many integration synergies in mobile or

fixed network architecture. WiMAX will also enable end-users to

benefit from an "Always Best Connected" experience when

accessing their applications via the best available network, at

home, on the pause, or on the move. WiMAX particularly fits in

Alcatel's vision for a User-Centric Broadband World in full

complementarity with the other broadband access technologies:

from ADSL to UMTS and their evolutions towards higher speed

and data efficiency.

WiMAX, making ubiquitous high-speed data services a reality

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

What is WiMAX? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Standards associated to WiMAX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

WiMAX, the reality beyond the hype . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

WiMAX product availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Market for WiMAX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

WiMAX, a complement to fixed and mobile access . . . . . . . . .2

WiMAX for fixed wireless access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Deployment topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

WiMAX for Portable Internet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

WiMAX, the natural complement to mobile and Wi-Fi networks . . . . . . . . . . . . .3

From nomadicity to Portable Internet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

The WiMAX CPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Operator’s business case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

WiMAX, the obvious choice for operators . . . . . . . . . . . . . . . . . . . . . . . . . . .4

WiMAX Technology Challenge . . . . . . . . . . . . . . . . . . . . . . . . . . .5

WiMAX, more flexibility and security . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

WiMAX, a very efficient radio solution . . . . . . . . . . . . . . . . . . . . . . . . . .5

System performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

WiMAX Spectrum and Regulation Issues . . . . . . . . . . . . . . . . . .5

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

WiMAX, making ubiquitous high-speed data services a reality

IntroductionBroadband Wireless Access (BWA) has been serving

enterprises and operators for years, to the greatsatisfaction of its users. However, the new IP-basedstandard developed by the IEEE 802.16 is likely toaccelerate adoption of the technology. It will expandthe scope of usage thanks to: the possibility ofoperating in licensed and unlicensed frequency bands,unique performance under Non-Line-of-Sight (NLOS)conditions, Quality of Service (QoS) awareness,extension to nomadicity, and more.

In parallel, the WiMAX forum, backed by industryleaders, will encourage the widespread adoption ofbroadband wireless access by establishing a brand forthe technology and pushing interoperability betweenproducts.

The purpose of this White Paper is to highlight andassess the value of WiMAX as the right solution to:

• extend the currently limited coverage of publicWLAN (hotspots) to citywide coverage (hot zones)- the same technology being usable at home andon the move,

• blanket metropolitan areas for mobile data-centricservice delivery,

• offer fixed broadband access in urban andsuburban areas where copper quality is poor orunbundling difficult,

• bridge the digital divide in low-density areaswhere technical and economic factors makebroadband deployment very challenging.

In addition to these uses, this paper will highlightother potential applications, such as telephony or aneffective point-to-multipoint backhauling solution foroperators or enterprises.

What is WiMAX?Standards associated to WiMAX

Worldwide Interoperability forMicrowave Access (WiMAX) is thecommon name associated to theIEEE 802.16a/REVd/e standards.These standards are issued by theIEEE 802.16 subgroup thatoriginally covered the WirelessLocal Loop (WLL) technologieswith radio spectrum from 10 to 66GHz. Recently, these specificationswere extended below 10 GHz.

• In January 2003, the IEEEapproved 802.16a as anamendment to IEEE 802.16-2001, defining (Near) Line-Of-Sight capability.

• In July 2004, IEEE 802.16REVd, nowpublished under the name IEEE 802.16-2004,introduces support for indoor CPE (NLOS)through additional radio capabilities such as antenna beam forming and OFDM sub-channeling.

• Early 2005, an IEEE 802.16e variant willintroduce support for mobility.

See Figure 1 for the applications associated witheach of these standards.

The WiMAX Forum intends to do for 802.16 whatthe Wi-Fi Alliance did for 802.11:

• harmonize standards and certifyinteroperability between equipment fromdifferent vendors. Standardized interoperablesolutions will result in mass volume and bringdown costs,

• promote and establish a brand for thetechnology.

WiMAX, the reality beyond the hypeAs mentioned above, WiMAX can offer very high

data rates and extended coverage. However,

• 75 Mbit/s capacity for the base station isachievable with a 20 MHz channel in bestpropagation conditions. But regulators willoften allow only smaller channels (10 MHz orless) reducing the maximum bandwidth.

• Even though 50 km is achievable under optimalconditions and with a reduced data rate (a fewMbit/s), the typical coverage will be around 5km with indoor CPE (NLOS) and around 15 kmwith a CPE connected to an external antenna(LOS).

ALCATEL 1 >

Fixed Outdoor

Applications• E1/T1 service for enterprises• Backhaul for Hotspots• Limited residential Broadband access

802.16a 802.16REVd 802.16e

CPE• External box connected to PC with outside antenna

Fixed Outdoor

Applications• Indoor Broadband access for residential users (High Speed Internet, VoIP,...)

CPE• External box connected to PC with built-in antenna

Limited Mobility

Applications• "Portable" Broadband access for consumers• Always Best Connected

CPE• PC Card

Fig. 1 The different flavors of WiMAX

WiMAX, making ubiquitous high-speed data services a reality

WiMAX product availabilityMass deployment of WiMAX

products is planned in two mainsteps:

• mid-2005, availability of the802.16REVd chipset, allowingthe development of cost-optimized CPE operatingindoors (NLOS),

• in 2006, availability of 802.16echipsets embedded in laptopsand later on in other mobiledevices, enabling PortableInternet.

We believe that current pre-WiMAX products and initial802.16a WiMAX productsavailable in early 2005, operatingsimilarly to current proprietary equipment (LOS, notcost-optimized CPE) and at similar cost, will not bewidely deployed, because the operator needs to goand install the antenna at the customer premise,which is uneconomical for residential customer asproved in the early days of ADSL installation. Thissaid, 802.16a will certainly be used for at least twoyears on the market window of backhauling ofoperators sites: wireless transmission of WiFi hotspottraffic to the nearest ISP point of presence, or dataleased lines concentration, or 3G new small sitebackhauling.

Market for WiMAXWiMAX will boost today's highly fragmented BWA

market thanks to standardization and interoperability,state-of-the-art radio efficiency with NLOS capability,and strong support from the radio equipmentmanufacturers and chipset industries.

WiMAX will also target the data-centric mobilitymarket with the introduction of lower power-consumption chipsets. The strong support from someof the most important chipsets manufacturers suchas Intel is a key enabler for the success of WiMAX,since it will lead to wide availability of affordableWiMAX-enabled terminals (e.g., laptops, PDAs, etc.).

WiMAX, a complement to fixed and mobile access

WiMAX integrates perfectly into existing fixed andmobile networks, complementing them when needed.

This section gives a more detailed analysis ofWiMAX integration into fixed and the mobilemarkets.

WiMAX for fixed wireless accessNationwide broadband access has become a priority

in many countries. In most developed countries, theaverage broadband coverage will reach 90% in thecoming years. Still, in some rural areas of suchcountries, broadband coverage will not exceed 50%.

The service gap can be categorized by twocharacteristics: the type of area (rural or urban) andthe level of national development (see Table 1).

In developed countries, DSL service deploymenthas been massive in urban and sub-urbandeployments, whereas coverage of remote areas -smaller towns and rural areas - is lagging behind.Hurdles to overcome are the poor line quality of theinstalled copper base, the large distances to thecentral offices or cabinets, or the low populationdensity. In this context, WiMAX, with its QoS

support, longer reach, and datarates similar to DSL, is naturallypositioned as a viable first mileoption to offer broadband accessto residential users.

> 2 ALCATEL

EnterpriseIP service & T1/E1

WiMAXHotzones

Nomadic DSL

Residential & SoHoWireless DSL

Point-to-Multipointbackhaul

802.16a/REVd

WiFi Hotspots

802.16e

Fig. 2 Markets for WiMAX

Focus on residential services

High-speed Internet and voice services

Scattered market, residential and enterprisemarket equally important

High-speed Internet and/orvoice service, E1/T1

Scope

Service

Rural accessin developed countries

Urban & suburban accessin developing countries

Tab. 1 The service gap

WiMAX, making ubiquitous high-speed data services a reality

In emerging countries, the main focus ofbroadband deployment is on urban and sub-urbanareas, and will remain so in the near future. Thelow POTS penetration and the low quality of thecopper pair prevent mass scale DSL deployment and foster the need for alternate broadbandtechnologies. In this context, WiMAX is positionedas an excellent option. Moreover, the possibility ofoffering broadband services in combination withvoice services will gradually lead to narrowbandWLL substitution.

Parameters such as availability of the copper,distance to the remote unit/central office,backhauling costs, and teledensity will drive thechoice for one or other of these solutions. Forfurther details, refer to the article "ProvidingAlways-on Broadband Access to Under-servedAreas" in the Alcatel Telecommunication Review (Q4 2003).

WiMax is of interest for large enterprises withseveral locations in the same metropolitan area.WiMax will permit Operator's bypass under licenseconditions: building a metropolitan private networkof IP lines at a very low cost (no civil works). Thecomparison to leased lines rental fee is in favor ofWimax even for two sites only.

Deployment topologiesSeveral topology and backhauling options are to

be supported on the WiMAX base stations: wireline

backhauling (typically over Ethernet), microwavePoint-to-Point connection, as well as WiMAXbackhaul. See Figure 3. With the latter option, thebase station has the capability to backhaul itself.This can be achieved by reserving part of thebandwidth normally used for the end-user trafficand using it for backhauling purposes.

WiMAX for Portable InternetWiMAX, the natural complement to mobile and Wi-FFi networks

Mobile networks offer full mobility, nation-widecoverage voice support and moderate data rates.WiMAX can then be positioned as a complementarysolution by offering higher bandwidth when required,in particular in dense urban areas.

Public WLAN, while offering clear benefits, islimited in coverage and mobility capabilities. WiMAXby-passes these limitations and offers broadbandconnectivity in larger areas (hotzones). Wi-Fi andWiMAX solutions are also complementary, with Wi-Fi being more adapted for short-range, indoorconnections (in particular in the enterprise and athome) and WiMAX for long- range outdoorconnections.

From nomadicity to Portable InternetWhile nomadicity offers connectivity within the

coverage area of a single base station, PortableInternet implies session continuity throughout thenetwork. In addition a new generation of networkswith multi-access (3G, Wi-Fi, WiMAX, DSL, FTTU,

ALCATEL 3 >

Radio linkcovered area

Base station Network CPE Building withNLOS terminals

Home withNLOS terminals

Home withLOS terminals

Urban3/4/6 sectors

Ruralwith self backhaul

Ruralwith fiber or PtP backhaul

Aggregation

Fig. 3 Topologies in urban and rural areas

WiMAX, making ubiquitous high-speed data services a reality

etc.) enable end-users to enjoy an"Always Best Connected"experience when accessing theirapplications via the best availablenetwork at home, on the pause, oron the move. See Figure 4. WiMAXbecomes an additional radio accesssolution in the global networkarchitecture.

The WiMAX CPEIn most case, a simple plug and

play terminal, similar to a DSLmodem, provides connectivity. SeeFigure 5. For customers locatedseveral kilometers from the WiMAXbase station, a self-install outdoorantenna may be required to improvetransmission quality. To serveisolated customers, a directiveantenna pointing to the WiMAXbase station may be required.

For customers requesting voice in addition tobroadband services, specific CPE will allow theconnection of standard or VoIP phones.

Ultimately, WiMAX chipset will be embedded in data-centric devices.

Operator's business caseWiMAX is of interest for incumbent, alternate, and

mobile operators. Some business cases are possible.

• The incumbent operators can use the wirelesstechnology as a complement to DSL, allowingthem to offer DSL-like services in remote, low-density areas that cannot be served with DSL.

• For alternate operators, the wireless technology isthe solution for a competitive high-speed Internet

and voice offering bypassing the landline facilities,with applicability in urban or sub-urban areas.

• The larger opportunity will come with thePortable Internet usage, complementing fixedand mobile solution in urban and suburbanareas. Therefore it will enhance the businesscase by giving access to a large potential of end users.

WiMAX, the obvious choice for operatorsBy integrating WiMAX into their networks, mobile

operators can boost their service with high bandwidth,when necessary, the same applications (messaging,agenda, location-based services, …) being offered onboth networks with a single billing and subscriberprofile. Mobile operators can also reuse existing radiosites and backhauling equipment to facilitate the

deployment of WiMAX.

Fixed operators,incumbent or alternate,will offer nomadic andPortable Internet usage as an addition to their fixed access offering tocomplement their DSL andWi-Fi bundle. For thosehaving deployed WiMAX forfixed access, this is also anatural evolution of theiroffering.

> 4 ALCATEL

Service Continuity

ADSL

GPRS/UMTS/WiMAX

On the MoveAt Home

PublicWLAN

HotspotsCorporate

LAN

At the Office

On the Pause

Fig. 4 “Always Best Connected”

WiMAX

Fig. 5 WiMAX CPE for f ixed access , WiMAX PC card and WiMAX PC enabled for Portable Internet

WiMAX, making ubiquitous high-speed data services a reality

WiMAX Technology ChallengeWiMAX, more flexibility and security

Unlike WLAN, WiMAX provides a media accesscontrol (MAC) layer that uses a grant-requestmechanism to authorize the exchange of data. Thisfeature allows better exploitation of the radioresources, in particular with smart antennas, andindependent management of the traffic of every user.This simplifies the support of real-time and voiceapplications.

One of the inhibitors to widespread deployment ofWLAN was the poor security feature of the firstreleases. WiMAX proposes the full range of securityfeatures to ensure secured data exchange:

• terminal authentication by exchanging certificatesto prevent rogue devices,

• user authentication using the ExtensibleAuthentication Protocol (EAP),

• data encryption using the Data EncryptionStandard (DES) or Advanced Encryption Standard(AES), both much more robust than the WirelessEquivalent Privacy (WEP) initially used byWLAN. Furthermore, each service is encryptedwith its own security association and privatekeys.

WiMAX, a very efficient radio solutionWiMAX must be able to provide a reliable service

over long distances to customers using indoorterminals or PC cards (like today's WLAN cards).These requirements, with limited transmit power tocomply with health requirements, will limit the linkbudget. Subchannelling in uplink and smart antennasat the base station has to overcome these constraints.

The WiMAX system relies on a new radio physical(PHY) layer and appropriate MAC layer to support alldemands driven by the target applications.

The PHY layer modulation is based on OFDMA, incombination with a centralized MAC layer foroptimized resource allocation and support of QoS fordifferent types of services (VoIP, real-time and nonreal-time services, best effort). The OFDMA PHYlayer is well adapted to the NLOS propagationenvironment in the 2 - 11 GHz frequency range. It isinherently robust when it comes to handling thesignificant delay spread caused by the typical NLOSreflections. Together with adaptive modulation, whichis applied to each subscriber individually according tothe radio channel capability, OFDMA can provide ahigh spectral efficiency of about 3 - 4 bit/s/Hz.

However, in contrast to single carrier modulation,the OFDMA signal has an increased peak: average

ratio and increased frequency accuracy requirements.Therefore, selection of appropriate power amplifiersand frequency recovery concepts are crucial.

WiMAX provides flexibility in terms ofchannelization, carrier frequency, and duplex mode(TDD and FDD) to meet a variety of requirements foravailable spectrum resources and targeted services.

An important and very challenging function of theWiMAX system is the support of various advancedantenna techniques, which are essential to provide highspectral efficiency, capacity, system performance, andreliability:

• beam forming using smart antennas providesadditional gain to bridge long distances or toincrease indoor coverage; it reduces inter-cellinterference and improves frequency reuse,

• transmit diversity and MIMO techniques usingmultiple antennas take advantage of multipathreflections to improve reliability and capacity.

System performanceTable 2 gives typical cell size and throughput at 3.5GHz in various configuration and environments.

WiMAX Spectrum and Regulation IssuesWiMAX-compliant equipment will be allowed to

operate in both licensed and unlicensed bands. Theminimum channel bandwidth for WiMAX usage is1.75 MHz per channel, while 10 MHz is considered asan optimum.

Although 2.4 GHz and 5 GHz non-licensed bandsare largely available, their usage could be limited totrials because of the risks of interference preventingQoS commitments.

The 2.5 and 3.5 GHz licensed bands will be the mostcommon bands for WiMAX applications. It should benoted that the 5 GHz band is also partially licensed insome countries.

Most countries have already allocated licensedspectrum, generally to alternate operators.Nevertheless large quantities of spectrum are still in

ALCATEL 5 >

21 Mbit/s w. 10 MHz channel

22 Mbit/s w. 10 MHz channel

22 Mbit/s w. 10 MHz channel

4.5 Mbit/s w. 3.5 MHz channel

4.5 Mbit/s w. 3.5 MHz channel

Sector throughput

1 km (5/8 miles)

2.5 km (1.5 miles)

7 km (4 miles)

5 km (3 miles)

15 km (9 miles)

Typical cell size

Urban indoor (NLOS)

Suburban indoor (NLOS)

Suburban outdoor (LOS)

Rural indoor (NLOS)

Rural outdoor (LOS)

Environment

Tab.2 Typical cell size and throughput

WiMAX, making ubiquitous high-speed data services a reality

process of allocation, and some countries have noteven defined any WiMAX licensed bands yet.

WiMAX is designed to accommodate eitherFrequency Division Duplexing (FDD), which is moresuited to enterprise traffic, or Time DivisionDuplexing (TDD), which is more adapted toasymmetrical traffic. Cohabitation of FDD and TDDtechniques is possible within the same bands,provided guard bands are implemented.

ConclusionThe latest developments in the IEEE 802.16 group

are driving a broadband wireless access (r)evolutionthanks to a standard with unique technicalcharacteristics. In parallel, the WiMAX forum, backedby industry leaders, helps the widespread adoption ofbroadband wireless access by establishing a brand forthe technology.

Initially, WiMAX will bridge the digital divide andthanks to competitive equipment prices, the scope ofWiMAX deployment will broaden to cover marketswhere the low POTS penetration, high DSLunbundling costs, or poor copper quality have acted asa brake on extensive high-speed Internet and voiceover broadband.

WiMAX will reach its peak by making PortableInternet a reality. When WiMAX chipsets are integratedinto laptops and other portable devices, it will providehigh-speed data services on the move, extending today'slimited coverage of public WLAN to metropolitan areas.Integrated into new generation networks with seamlessroaming between various accesses, it will enable end-users to enjoy an "Always Best Connected" experience.

The combination of these capabilities makesWiMAX attractive for a wide diversity of people: fixedoperators, mobile operators and wireless ISPs, butalso for many vertical markets and local authorities.

Alcatel, the worldwide broadband market leaderwith a market share in excess of 37%, is committed tooffer complete support across the entire investmentand operational cycle required for successfuldeployment of WiMAX services.

Glossary

CPE Customer Premise EquipmentDSL Digital Subscriber LineFDD Frequency Division DuplexMAC Media Access Control

MIMO Multiple-Input-Multiple-OutputNLOS Non-Line-Of-Sight

OFDMA Orthogonal Frequency Division Multiplex AccessPLC Power Line Communications

POTS Plain Ordinary Telephone SystemSTC Space Time Coding

TDD Time Division DuplexWLAN Wireless Local Area Network

WLL Wireless Local Loop

References

WiMAX: The Critical Wireless Standard, BluePrint WiFi Report,October 2003WiMAX/802.16 and 802.20, ABI Research, Q4 2003Last Mile Wireless High Speed Market, Skylight Research,March 2004Providing Always-on Broadband Access to Underserved Areas,Alcatel Telecommunication Review (p. 127-132), Q4 2003WiMAX forum web site: www.wimaxforum.org

> 6 ALCATEL

WiMAX, making ubiquitous high-speed data services a reality

ALCATEL 7 >

LAINE PhilippeNetwork Strategy Manager, Chief TechnologyOfficer organization. After his university studies in Electrical Engineering,Philippe started his career in 1985 as a software

engineer, working on various projects in telecommunications andsatellite image processing. In 1989, Philippe joined Alcatel, at firstworking on a cable TV project, then as project manager in chargeof the development of network management systems.From 1995 to 2001, as marketing manager in the MobileNetworks Division, he handled the promotion of GSM, GPRS, and3G mobile systems. Based on this experience, he joined theNetwork Strategy Group to define and promote the corporatevision for the evolution of wireless networks.

BOETTLE DietrichProject Leader, Wireless Access, CTO/Research &Innovation.After his studies at the University of Stuttgart, Dietrichjoined Standard Elektrik Lorenz (SEL), now Alcatel, in

Stuttgart, Germany. His main activities in the past included managingprojects and leading research teams in the areas of opticaltransmission and broadband switching.He is currently head of the Access Network department in Stuttgart andproject leader for the Alcatel project Wireless DSL in Research andInnovation.

BOSCHER ChristopheNetworking Strategy, Chief Technology Officerorganization within the Mobile Communications Group.Christophe is a member of the CTO organization withinthe Mobile Communication group. He focuses on

networking strategy for ubiquitous broadband access delivery.Christophe obtained an engineer’s degree in electrical engineeringfrom the Ecole Polytechnique de l’Université de Nantes in 1988.Prior to his current position, he held a variety of positions within severalAlcatel business units in charge of data networking. He worked tenyears in R&D as a software developer and system engineer on severaldata systems, beginning with X.25 and evolving to Frame Relay, ATM,and IP/MPLS. He has also been product manager in charge of Voice-over-DSL solutions.

FEIJT LaurenceBroadband Access, Solution Marketing, SolutionMarketing Management within the FixedCommunication Group.Laurence graduated in business studies at the Institut

Catholique des Hautes Etudes Commerciales (ICHEC) in Brussels(Belgium). She took a postgraduate course in Telecommunications atthe Université Libre de Bruxelles (ULB) and earned her MBA inTelecommunications Marketing at INSEAD.Laurence joined Alcatel in 1998 in the product management team forNGN. Today, she works in the Broadband Access Solution team,responsible for the development of end-to-end solutions in theBroadband Access Space including xDSL, WLAN, and other fixedwireless technologies. She is also involved as consultant in the AlcatelConsultancy Program for xDSL customers. Laurence has written and contributed to several papers on topicsrelated to broadband access.

Alcatel and the Alcatel logo are registered trademarks of Alcatel. All other trademarks are the property of their respective owners. Alcatel assumes no responsibility for the accuracy of the information presented, which is subject to change without notice.

© 06 2004 Alcatel. All rights reserved. 3GQ 10001 0014 TQZZA Ed.02