WiMax moves (slowly) toward implementation

CHICAGO'WiMax broadband technology has made some important steps toward real-world implementation, but many customers may be waiting for assurances of multivendor interoperability before investing in the new wireless equipment.

The WiMAX Forum, an industry group promoting the adoption of the new technology, returned to the SuperComm trade show this week to host demonstrations of member companies' products.

'A lot has happened in the past year,' said David Sumi, a vice president of marketing for TeleCIS Wireless Inc. of Santa Clara, Calif., and a forum member.

The first chipsets for the wireless technology have been announced, the WiMAX Forum has selected its first laboratory for product certification and agreements have been reached between U.S., European and Korean industry groups to harmonize standards for wireless broadband.

'The main thing that has happened in the last year is that people have been out deploying the WiMax kit,' said Carlton O'Neal, vice president of marketing for Alvarion Inc. of Mountain View, Calif.

The schedule for certifying products slipped by six months in the last year, but 'even without certified equipment, the carriers are showing a great demand,' O'Neal said. 'There is some risk' in buying precertification products, he conceded, 'but we don't think it's a lot.'

WiMax is based on the evolving 802.16 family of standards for delivering high-bandwidth data transmission over long distances. It is seen as a wide-area complement to the popular 802.11 WiFi services and a competitor for such last-mile technologies as digital subscriber line and cable modems.

The 802.16 Air Interface Standard focuses on fixed broadband wireless access operating between 10 and 66 GHz or from 2 to 11 GHz. The first iteration, 802.16a, addressed the lower end of the spectrum. It is now at revision 802.16d. Another standard, 802.16e, which addresses mobile applications, is in final development.

The lower-frequency spectrums in the 3.5-GHz band now being used in WiMax products primarily are for outdoor installations because they do not have the good penetration needed for interior uses. They provide non-line-of-sight connections, which eases some of the difficulties in setting up base stations.

Current implementations are primarily fixed access points providing last-mile alternatives to DSL and cable modem connections. The range for each access point typically is 3 to 10 kilometers, with a capacity of up to 20 Mbps per channel for fixed access applications.

One example of early adoption of WiMax is remote Allegany County in mountainous Western Maryland, O'Neal said. The government wanted to network its 900 public buildings, but could afford to run fiber-optic cable to only 30. It decided to use WiMax to eke out the network even though standards were not complete.

Equipment manufacturers have great hopes for a federal WiMax market. WANs and metropolitan area networks for office campuses and military bases would be ideal applications for the technology, they say. But like most of the U.S. market, the feds are in a testing, not an adopting, stage.

Federal customers are interested in off-the-shelf products and services, and carriers are waiting for certified interoperability before adding WiMax to their shelves.

Even though standards are in place and working products are in the market, 'having standards doesn't ensure market acceptance, because it doesn't ensure interoperability,' Sumi said.

Ensuring interoperability is the job of the WiMAX Forum, which had expected to begin conformance testing for products late last year. But that has slipped to July of this year.

The forum in April selected Spanish testing firm Cetecom S.A. to perform certification testing. It is expected to begin accepting vendor equipment in July, with the first certifications to come in November or December.

Intel Corp., Fujitsu Microelectronics America Inc. of Sunnyvale, Calif., and Wavesat Inc. of Montreal have announced early WiMax chip sets. TeleCIS is developing what it said will be among the earliest of the second generation of WiMAX chips.

'We have another six months of work,' Sumi said. 'We're not going to see our chips until the end of the year. However, they will be smaller, use less power and will have greater feature sets.'

Among the improved features will be better performance on non-line-of-sight links. This will enable users to establish links without hiring professional installers. Sumi said such do-it-yourself installations could expect to support ranges of about a mile from the base station. The range if professionally installed and tuned could be many times that.

WiMAX implementations and certification specs so far have been for fixed communications. Coming in the next year will be more mobility as the 802.16e specifications are completed for applications such as cellular.

'Mobile WiMax will move from specifications committees to demo equipment in the next 12 months,' O'Neal said.

But moving from demonstrations to interoperable equipment will be complicated.

'Mobile is a lot more iffy right now,' Sumi said. It is more complex than fixed links and there are more ways to address the problems. 'When you talk about mobile broadband, it becomes a grab-bag with everyone going for it.'

Mobile WiMax could compete with third-generation Code Division Multiple Access technology, intended to deliver more bandwidth and functionality to handheld cellular devices.

'3G bandwidth is not that impressive,' Sumi said. It provides 1 to 2 Kbps per user, rather than the megabit-range speeds promised by WiMax. 'There are religious wars on either side about whether 3G can deliver that.'