WiMax has suffered from its own hype (see our articles on the hype cycle) to the extent that people are not sure what it will deliver when. Here are the latest answers from the WiMax Forum, the body set up to promote networking by WiMax (or IEEE 802.16, to give it its formal name).

What is emerging is not just how fast the technology will go, but also what parts of the spectrum it will use. The basic WiMax standard can operate over a broad range of freqencies: which ones get implemented in product depend on what will sell. In most cases that means what can legally be sold in any given country. And surprisingly enough, the frequencies that will be standardised and implemented first are not just those that suit the US market.

It's a wireless DSL-alike
It is worth reiterating that WiMax is not Wi-Fi. It is much, much more like ADSL, only without the phone lines. It is fixed wireless. It is local loop replacement. Initially the 802.16 spec will support 300 kbit/s to 2 Mbit/s (ie the same speeds as DSL more or less) over a distance of up to 30 miles (ie much further than DSL).

There's a mobile version coming, which Intel plans to put in mobile devices as an extension to Centrino, with the prospect that "Centrino Plus" laptops would be able to connect at DSL-like speeds in a much broader area, away from Wi-Fi hotspots. However, the standard won't be done for at least another year, so don't hold your breath waiting.

Getting the technology available for the right price is one issue, and it will take time. By the third quarter of 2005, the box that delivers WiMax service to an office or home (called customer premises equipment or CPE) will cost less than $500 in the US, predicts Kevin Suitor, vice president of business development at Redline Communications, a maker of 802.16-based equipment. By 2007, it will cost less than $200, he says.

In other words, the fixed version is always going to be more expensive than DSL equipment, and suitable mostly for situations where DSL isn't available, unless faster versions take off.

"The scale is not necessarily the same kind of scale that you have with the Wi-Fi chips," says Tad Neeley, of industry analysts RHK. "The cost curve I look at with this is far more what DSL modems and cable modems did. I don't think it's going to be the Wi-Fi cost curve."

The mobile version might take off differently, but vendors don't give dates for that. The chips could be built into notebook PCs when the cost of the chipset hits $50 to $100 (whenever that is), Suitor says.

Which wavelengths?
Whether WiMax succeeds will depend on how quickly the vendors can sell large volumes of product, and that will depend on how well they choose the wavelengths to implement.

The Wi-Fi standards (the IEEE 802.11 family) specify what frequency should be used: almost universally the 2.4 GHz spectrum, for 802.11b and 802.11g, with a small amount of 802.11a in the 5 GHz band. That spectrum is licence exempt almost everywhere, so vendors and make and sell product freely, as long as it keeps within certain power limits.

WiMax is based on standards that allow for any frequency band between 2 GHz and 11 GHz. In theory, a WiMax system could be designed for the licence exempt bands used by Wi-Fi, but this isn't likely. It will be implemented on other less-used spectrum and even on licensed bandwidth.

The WiMax Forum is creating profiles designed for specific bands, says Francois Draper, vice president of sales and marketing at WiMax chip developer Wavesat Technologies and chairman of memberships at the WiMax Forum. These aren't expected to start appearing until September, and have been chosen to make the biggest possible markets for WiMax equipment and the freest possible installation.

The group is lining up around three bands:

  • 5.8 GHz, which is unlicensed in many countries (and effectively unlicensed in the UK, since Ofcom announced a "light touch" licensing scheme)
  • 3.5 GHzlicensed in several regions, and a near miss for the 3.4GHz spectrum which a botched auction in the UK left in the hands of one company, Pacific Century Cyberworks
  • 2.5 GHz licensed in the U.S. and much of the Americas.

The WiMax has announced a regulatory working group to promote global harmonisation of the management of those bands. It will also work for the allocation of spectrum in lower bands such as those the US Federal Communications Commission is considering for reallocation from TV stations.

Conformance among governments on spectrum issues is complicated, bringing into account formats - how capacity is divided up among subscribers - as well as the spectrum itself, says Nitin Shah, an analyst at RHK. "The diversity of spectrum and formats does limit or impede the rate of adoption of WiMax," Shah says.

Unlike the Wi-Fi model, which exists happily in unlicensed spectrum, WiMax needs licensed spectrum. Licensed frequencies are critical for carriers to offer business-class WiMax services, according to vendors and industry analysts. That further complicates the picture with bureaucracy, politics and frequency allocation, Shah says.

Intel says it can do the integration needed to propel the market forward. It will follow the WiMax Forum's lead on frequencies for fixed and mobile WiMax equipment, says Joe English, director of marketing for WiMax at Intel. Intel expects to integrate WiMax in its Centrino wireless chip set along with Wi-Fi beginning in late 2006, with a wide rollout in 2007. The company envisions one Centrino chip set that supports all the frequencies used for WiMax worldwide and can be produced in volumes large enough to keep prices down, English says.

Service providers optimistic
Some service providers are anxious for those economies to come into play. Covad Communications sees wireless as a tool for reaching customers it can't get to with DSL for regulatory or other reasons, says Ron Marquardt, technical director. The company would prefer to use WiMax because of the expected benefits of standardisation, but it's not committed yet, he says.

Neotec, a consortium of mobile operators in Brazil, wants to offer wireless broadband for about $20 per month and says it thinks it can do that by not laying wires. It has tested a proprietary system that uses licensed spectrum around 2.5 GHz and is looking to WiMax for the price-cutting power of standardisation.

In the UK, BT has spoken in favour of WiMax for its recently announced next generation network.

In the end, market momentum might shape regulation, Wavesat's Draper says."If the industry wields its baseball bat, they may make the governments move faster," he says.