Enter the hot zone

It’s no accident that WiMax sounds something like Wi-Fi. I’m sure the name was intentionally picked to evoke Wi-Fi capabilities taken “to the max.”

Unfortunately, what may have sounded like a brilliant idea to the technology folks at the WiMax Forum is a bit of a nightmare, in my humble opinion — one that has led to confusion and incorrect assumptions about what WiMax is and isn’t.

First of all, WiMax is not long-distance Wi-Fi. In fact, WiMax networks are not interoperable with Wi-Fi networks out of the box. If you wanted to use both, you would need a base station with both radios inside.

Second, WiMax is not mobile. Initially at least, it will be usable only in fixed wireless networks, from a tower to an AP — or customer premise equipment, as it is called.

For the most part, WiMax will use the licensed spectrum, which means service providers will have to pay the Federal Communications Commission for bandwidth. Yes, WiMax can also work in the unlicensed spectrum above 5GHz, but those frequencies require line of sight and work only at shorter distances, according to Ron Resnick, president and chair of the WiMax Forum. Using those bands would effectively negate the long-distance value of WiMax. So don’t expect to see free, ad hoc WiMax networks springing up around the country.

But using licensed spectrum does give operators the right to use greater output power. Thus, the first WiMax specification — IEEE 802.16 — is for 75Mbps at distances as far as 30 miles, although actual data throughput for individual users will vary depending on distance. Given that range, Resnick says that metropolitan hot zones based on WiMax will eventually compete with current Wi-Fi hot spots.

“A metro zone is a gigantic or mega hot spot as big as the city. That is what this is all about,” Resnick says. “Wi-Fi works indoors and works great for a LAN. You can’t wire an entire city that easily with Wi-Fi.”

Because the available spectrum for WiMax is so broad, the WiMax Forum is in the process of creating so-called profiles that address subsets of the full WiMax functionality, targeted at specific markets.

In the short term, the two primary applications are likely to provide last-mile connectivity to homes and small businesses and to function as backhauls to hot spots where copper and fiber are not cost-effective choices. Resnick says that although it is hard to figure out how to make money on a hot spot, providing a backhaul to the Internet at high speeds is an established business model. When all is said and done, however, Intel’s WiMax road map clearly leads to mobility.

“Our client devices will support all the profiles in the [WiMax] network,” says Jim Johnson, general manager and vice president of the wireless networking group at Intel. “Once we set up metropolitan hot zones, mobile users could get on.”

In 2005, the IEEE standards body is expected to ratify 802.16e — mobile WiMax. By 2006, Intel will offer built-in WiMax chips that add the first degree of portability. One more step remains: roaming capabilities between WiMax networks so people, trucks, public safety entities, and the like can stay connected on the go. Expect this capability in the 2007 time frame.

Despite its unfortunate nomenclature, WiMax technology holds a lot of promise. And although no one sees it replacing Wi-Fi on the corporate campus, it is another important step towards creating a totally connected globe.