INDUSTRY TRENDS

potential. Many residents thus must do without service. Achieving Wireless approaches could address this problem. Therefore, proponents are advocating WiMax (worldwide interoperability for access), Broadband with a technology based on an evolving standard for point-to-multipoint wire- less networking. Carriers can use WiMax to provide wireless WiMax service via transceivers to users’ anten- nas. Steven J. Vaughan-Nichols Craig Mathias, principal analyst for the FarPoint Group, a technology and market analysis firm, said WiMax is the commercialization of the maturing hen users want broad- IEEE 802.16 standard, which specifies band Internet service the -frequency technology for today, they’re generally wireless metropolitan area networks. W restricted to a T1, DSL, In addition to IEEE 802.16, WiMax or cable--based addresses the European Telecommuni- connection. However, these wireline cations Standards Institute’s (ETSI) infrastructures can be considerably similar high-performance radio met- more expensive and time consuming ropolitan area network (HiperMAN) to deploy than a wireless one. broadband standard, explained Dean In addition, rural areas and devel- broadband services, and providers are Chang, director of product manage- oping countries frequently lack optical unwilling to install the necessary ment for Aperto Networks, a vendor fiber or copper-wire infrastructures for equipment for regions with little profit of broadband wireless access systems, and also a board member of the WiMax Forum. The forum is a wire- Promoting the Technology: The WiMax Forum less industry consortium supporting WiMax technology and promoting its The WiMax Forum (www.wimaxforum.org)—a wireless industry consor- commercial use. The “Promoting the tium with about 100 members including such major vendors as AT&T, Fujitsu, Technology: The WiMax Forum” side- Intel, and Siemens Mobile—is supporting WiMax technology and promoting its bar provides additional information commercial use. As WiMax has gained traction, major companies such as British about the consortium. , France Telecom, and Qwest Communications have joined the forum. DRIVING FORCES BEHIND WIMAX The forum is preparing profiles for systems that comply with WiMax speci- Point-to-multipoint microwave net- fications and creating interoperability tests to make sure different vendors’ imple- works from companies such as Alcatel mentations work together. and Siemens have existed for years, but Eventually, vendors will be able to advertise that they are selling forum- they have relied on proprietary tech- certified, WiMax-compliant equipment. The forum plans to begin certifying nology. WiMax, on the other hand, products by the end of this year, according to board member Dean Chang, who offers a standardized technology. is also director of product management for Aperto Networks, a vendor of broad- WiMax’s open approach could let band wireless access systems. manufacturers achieve economies of Although WiMax will support traffic based on various data-transport tech- scale by building large quantities of nologies such as asynchronous transfer mode, , and the Internet products and components to one Protocol, the forum will certify compliance only for the IP-related aspects of standard. It would also let equipment IEEE 802.16 products, explained Margaret LaBrecque, director of Intel’s makers buy lower-cost, standards- Industry Program for Broadband Wireless Division. compliant components from compet- The focus is on the Internet Protocol because so many networking operations ing suppliers, explained Edward Rerisi, are IP based, noted Chang. director of research for Allied Business Intelligence, a market research firm.

10 Computer This would help existing wireless service providers. In addition, carriers without a mobile network could start Switching a WiMax system at relatively low cost. center WiMax would also enable interop- erability between systems, Mathias noted. Residential Public Rerisi anticipates that WiMax will subscriber telephone Internet network provide high-speed network connec- service tions and thereby serve as a backbone provider for IEEE 802.11 wireless LAN Office building Base station spots, where roaming mobile users can subscribers access carriers’ WiFi services. WiMax could thus offer a less expensive, easier to build infrastructure than the wire- Figure 1. Initial plans are to use WiMax—a point-to-multipoint, broadband wireless- line WiFi backbones that DSL, cable, networking technology—for . Carriers would set up rooftop transceivers as or T1 systems currently provide. base stations connected to the Internet. Each base station would use WiMax technology These factors, along with public to communicate with fixed, externally mounted subscriber antennas. demand for broadband services, will cause the WiMax and wireless-broad- generation cellular technology has a division multiplexing. OFDM increases band markets to grow, predicted Rerisi. range of several thousand feet. bandwidth and data capacity by split- Nonetheless, the technology faces As Figure 1 shows, WiMax propo- ting broad channels into multiple several stiff challenges before it can nents’ initial vision is that carriers will channels—each using a become widely popular. set up rooftop transceivers as base sta- different frequency—that can then tions connected to the Internet. Each carry different parts of a message simul- INSIDE WIMAX base station would use WiMax tech- taneously. Because WiMax is based on IEEE nology to send and receive data to The channels are spaced very close 802.16 and HiperMAN, the IEEE and and from fixed subscriber antennas, together but avoid interference because ETSI have each adapted its standard to mounted on rooftops or external walls. neighboring channels are orthogonal include many of the other’s important WiMax vendors are currently work- to one another and thus have no over- features. ing to upgrade the technology so that lap, explained Professor Douglas Jones IEEE 802.16 divides its media-access- customers could use interior antennas. of the University of Illinois, Urbana- control layer into sublayers that support Champaign. different transport technologies, includ- Basic IEEE 802.16 The initial 802.16 standard operates ing IPv4, IPv6, Ethernet, and asynchro- Unlike other wireless standards, in the 10 to 66 GHz range. At these nous transfer mode. This lets vendors which address transmissions over a higher frequencies, IEEE 802.16 re- use WiMax no matter which transport single frequency range, WiMax allows quires a direct line of sight between technology they support. data transport over multiple broad fre- senders and receivers. This reduces WiMax has a long transmission quency ranges. multipath distortion, which occurs range—up to 31 miles—because regu- Being able to work in multiple when broadcast signals not following lations allow WiMax systems to trans- ranges maximizes the technology’s a line of sight bounce off of large mit at high power rates and because ability to transmit over the frequencies objects and end up out of synch, the approach’s use of directional anten- that will avoid interfering with other thereby scrambling the received trans- nas produces focused signals. wireless applications. mission and decreasing bandwidth. To keep from serving too many cus- In addition, Aperto Networks’ Chang Reducing multipath distortion, there- tomers and thereby greatly reducing explained, WiMax’s transmission range fore, increases bandwidth. Theoretically each user’s bandwidth, Rerisi said, and data rate vary significantly depend- IEEE 802.16 can provide single-chan- providers will want to serve no more ing on the frequency bands an imple- nel data rates up to 75 Mbits per sec- than 500 subscribers per 802.16 base mentation uses. This flexibility lets ond on both the uplink and downlink. station. Thus, he noted, each station providers use different frequencies Providers could use multiple IEEE will probably serve an area within a depending on the range and speed 802.16 channels for a single transmis- 10-mile radius. required for a specific transmission. sion to provide bandwidths of up to WiFi, on the other hand, has a range The technology achieves high data 350 Mbps. of only several hundred feet, and third- rates in part via orthogonal frequency The popular IEEE 802.11b WiFi

June 2004 11 Industry Trends

Referring to this extension, Margaret LaBrecque, director of Intel’s Industry 900 Program for Broadband Wireless 800 Division, said, “It’s three to five years 700 from deployment.” 600 500 WiMax chipsets 400 Various vendors plan to release 300 WiMax chipsets. For example, Wave- 200 sat, in partnership with Atmel, hopes (millions of US dollars)

WiMax equipment revenue 100 to produce them this year. Fujitsu is 0 also working on WiMax chipsets. Intel 2003 2004 2005 2006 2007 2008 plans to sell chipsets that will include Source: www.3G.co.uk both the 802.11 and 802.16 technolo- gies. The products include both net- Figure 2. As WiMax technology becomes more popular, equipment sales are expected to working circuitry and a radio. The grow significantly. antenna is located off the chipset. The chipsets initially will be implemented wireless LAN technology’s maximum maintaining the technology’s data rate in transceivers and later in computers data rate is only 11 Mbps per channel, and transmission range. themselves. while the newer 802.11a and 802.11g IEEE 802.16a supports mesh deploy- A challenge in implementing WiMax theoretically provide up to 54 Mbps, ment, in which transceivers can pass a on chipsets, Chang explained, is that the although all deliver less in practice. single communication on to other powerful radio section can cause heat Third-generation cellular technologies transceivers, thereby extending basic problems and also interfere with the will offer up to 115 Kbps. 802.16’s transmission range. networking component’s operations. For security, WiMax uses public- IEEE 802.16b. This extension increases key-infrastructure authentication, in the spectrum the technology can use in FACING CHALLENGES which trusted authorities identify par- the 5 and 6 GHz frequency bands and Some critics argue that much of the ties to a transmission via digital cer- provides quality of service. WiMax pro- needed to deploy tificates. The system encrypts data via vides QoS to ensure priority transmis- WiMax has already either been dis- 56-bit Data Encryption Standard keys. sion for real-time voice and and tributed by governments or dedicated Meanwhile, WiMax is highly scal- to offer differentiated service levels for for other purposes by carriers. able because it is easy to add transmis- different traffic types, Chang explained. Also, the cost of deploying wireless sion channels to provide more band- IEEE 802.16c. According to Marks, technology is considerably more when width as necessary. IEEE 802.16c represents a 10 to 66 the service is offered at higher radio GHz system profile that standardizes frequencies because the line-of-sight IEEE 802.16 extensions more details of the technology. This requirements necessitate the installa- The IEEE’s 802.16 Working Group encourages more consistent imple- tion of additional antennas to cover the has adopted several extensions to the mentation and, therefore, interoper- same service area. The frequencies technology’s basic standard, noted ability. available for new technologies such as Working Group chair Roger B. Marks, IEEE 802.16d. According to Chang, WiMax are frequently the higher ones a scientist with the US National Institute IEEE 802.16d includes minor improve- because many of the more desirable of Standards and Technology. ments and fixes to 802.16a. This exten- lower spectrum ranges have been IEEE 802.16a. The IEEE has devel- sion also creates system profiles for licensed for other uses. oped 802.16a for use in licensed and compliance testing of 802.16a devices. However, Allied Business Intelli- license-exempt frequencies from 2 to IEEE 802.16e. This technology will gence’s Rerisi said, “There’s still lots of 11 GHz. Most commercial interest in standardize networking between car- unlicensed spectrum available in the IEEE 802.16 is in these lower fre- riers’ fixed base stations and mobile 2.5 to 3.5 GHz range, and companies quency ranges. devices, rather than just between base like Sprint and Nextel already have a At the lower ranges, the signals can stations and fixed recipients. IEEE ton of spectrum they’re not using.” penetrate barriers and thus do not 802.16e would enable the high-speed WiMax, particularly the mobile ver- require a line of sight between trans- signal handoffs necessary for commu- sion, may face serious competition ceiver and antenna. This enables more nications with users moving at vehic- from IEEE 802.20 flexible WiMax implementations while ular speeds. technology, which targets high-speed,

12 Computer wireless, IP-based connectivity to will increase rapidly at least through Mathias said he doesn’t see WiMax devices such as cellular phones, PDAs, 2008, as Figure 2 shows. overtaking DSL and cable as a popu- and laptops. The technology will However, because not all aspects of lar broadband Internet-access technol- operate in the 500 MHz to 3.5 GHz the technology have been finalized, the ogy because they’re so well established. range. FarPoint Group’s Mathias said, “Mass The real key for WiMax in the mar- While the two standards are not deployment is a couple of years away.” ketplace, he said, will be how IEEE designed to do exactly the same things, The WiMax Forum, Chang explained, 802.16e functions as a mobile ap- Rerisi said, “They both aim to serve won’t even release WiMax certification proach, because this is where future similar [mobile] users.” tests until late this year. market demand for the technology will WiMax will have to compete with be the greatest. any analysts say WiMax will the proprietary broadband wireless become successful and popular, technologies that are already estab- Steven J. Vaughan-Nichols is a - M in part because of strong sup- lished in the marketplace, Rerisi noted. lance technology writer based in port from Intel, which has considerable Nonetheless, he said, if WiMax Arden, North Carolina. Contact him resources, marketing muscle, and influ- companies don’t give up, they may at [email protected]. ence. well begin to gain on proprietary The www.3G.co.uk news service, approaches by the end of this decade which focuses on third-generation because of the interoperability and Editor: Lee Garber, Computer; wireless technology, estimates that rev- lower prices that the standardized tech- [email protected] enue from WiMax equipment sales nology will offer.

Join the IEEE ONE PUBLISHER Computer Society ALL THE SOLUTIONS online at b

www.computer.org/join/

Complete the online application and get • immediate online access --- . --- . to Computer • free access to more than 100 distance learning Call For Papers - course titles  Individual  Corporate • access to the IEEE Computer Society Digital Library for only $55* --- . --- . *Regular price $109. Offer expires 15 August 2004 b    Read about all the benefits CHARLESRIVER.COM of joining the Society at Titles also available at Amazon, Borders, www.computer.org/join/benefits.htm Barnes & Noble, and other fine retailers.

June 2004 13