INDUSTRY TRENDS potential. Many residents thus must do without broadband service. Achieving Wireless Wireless approaches could address this problem. Therefore, proponents are advocating WiMax (worldwide interoperability for microwave access), Broadband with a technology based on an evolving standard for point-to-multipoint wire- less networking. Carriers can use WiMax to provide wireless Internet 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 radio-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-modem-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. Telecommunications, 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, Ethernet, 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 hot 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 Internet access. 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 narrowband 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-