Takin' It To The WiMax
By Carlo Longino, Wed Feb 04 07:15:00 GMT 2004

The burgeoning WiMax standard looks to capitalize on the wireless data revolution that Wi-Fi has started.


Wi-fi has made it commonplace for people to expect megabit speeds to their computers and other devices without wires, albeit at relatively short ranges. WiMax promises to increase those speeds to up to 70 Mbps, and the distances up to 50 kilometers. It looks set to revive the fixed-wireless market, which died an expensive death a few years back, and could eventually shake up carriers' 3G plans as well.

WiMax is the brand name given to products based on the IEEE 802.16 standard, also known as WirelessMAN, or the snappy "Air Interface for Fixed Broadband Wireless Access Systems". It's intended to initially provide fixed last-mile broadband access as a replacement or substitute for wired DSL, cable, or T1 connections, and later to offer mobile access. WiMax's long reach makes it a good fit for rural areas where wired broadband isn't an option, while it also allows end users to side-step incumbent phone and cable companies for high-speed Net access.

The ideal WiMax application thus far is as backhaul for Wi-Fi hotspots, but future revisions to the standard should see it emerge as a better option with which to blanket large areas (think city-size) with connectivity than Wi-Fi. Intel, which has become a major WiMax backer, has said its first 802.16 chips will be based on the "d" revision, which should be approved in March. Though products based on the "a" spec are becoming available, the release of d products, expected in 2005, should be the tipping point.

Early end-user equipment, though suitable for fixed access, is too big and requires too much power to fit into a form factor suitable for a laptop or smaller mobile devices, but clearly Intel will push WiMax this way, as it's done with Wi-Fi and Centrino. Other companies like Nokia and Siemens are also working to incorporate WiMax into mobile devices, getting a jump on the "e" variation, which will add mobile support to the standard, and is expected to be completed in the first half of next year.

It's this scenario which may worry mobile carriers -- 70 Mbps of shared bandwidth to mobile devices, possibly in unlicensed spectrum, that allows a user to roam around on their wireless ISP seamlessly from their home Wi-Fi network. This is a double-edged sword, as it could allow independent, upstart ISPs to quickly and cheaply blanket an area with hotspot coverage, but it also offers carriers an opportunity to offer integrated services, from a home or office level, to a high-speed hotspot, and on to wide-area cellular coverage.

Mobile carriers' burning question, though, may be how WiMax will compete with their cellular networks. The initial reaction to hearing of a Wi-Fi-esque technology that allows for 70 megabits at up to 50 kilometers is that it will leave 3G dead in the water -- but that probably will not be the case. The first device-level WiMax products, like laptop cards, won't be on the market for quite some time, with estimates ranging from 2 to 5 years. On the short end of those estimates, 3G should be old hat in most developed markets and outdated in advanced ones, and in 5 years, 4G should be a reality in Asia and taking shape in the rest of the world.

WiMax may also not be a complete competitor because the e spec isn't engineered from the start as a mobile standard, leaving it open to something like 802.20, which seeks to offer speeds of 1Mbps and up at cell ranges of up to 15km or more, to users traveling as fast as 250km/h. 802.16e serves users traveling at "vehicular" speeds of 120-150km/h. The delay in getting both of these standards to market, however, could see proprietary systems sprout up in their place.

But WiMax can't be written off as a threat, though, because of its economics, and some carriers, like Nextel, are looking into it. It could easily allow a WISP to quickly get up and running in an area, and it should eventually support mesh networking, allowing them to readily grow their coverage without additional wired backhaul. Intel says a single base station sector provides enough bandwidth for 60 T-1 level connections and hundreds of DSL-level connections, with a base station estimated to cost between $5,000 and $30,000.

The WiMax Forum and its member companies are working hard within the IEEE to standardize its technology not just to make different vendors' products compatible, but also to leverage economies of scale and drive down costs. It of course eliminates costly cable-laying, but also the infamous "truck rolls" and installations. While the first phase of WiMax launches will likely require outdoor antenna installations, vendors are hoping to quickly offer indoor antenna-based equipment that will require a minimum of set-up, their ideal goal being a customer simply plugging in the CPE to their computer, logging on and entering identification or payment details, and going on their way.

While WiMax may not challenge 3G, it has the potential to shake up how we see wireless data on a metropolitan- or wide-area level, much like Wi-Fi has revolutionized the local-area network.