The plan follows the completion of a new draft of the standard that backers said will be the version they take to silicon.

The 68 members of the WiMax Forum are rallying around IEEE 802.16a as a means for bringing a common standard to what has been to date a field of highly proprietary and relatively expensive systems for carrier-class broadband wireless access (BWA). The spec defines systems that can deliver up to 74 Mbits/s of bandwidth over distances up to 50 km using spectrum bands that can range from 6 to 11 GHz.

At the Vancouver 802 plenary meeting last week, engineers finished work on revision D of .16a. The new revision is expected to be formally adopted in a vote in the third quarter, but chip and systems makers say at this point the spec is now solid enough to finish the designs for first-generation chips. Those chips are expected to ship at about the same time the spec is officially ratified. The WiMax Forum plans to finish a test suite for compliance to the standard by October and hold its first "plugfests" in November or December to check that first systems conform to the standard. System makers will then have to undergo final conformance testing, a process that initially could take about a month, at a lab yet to be set up. That opens the door to the possibility of the first WiMax-compliant systems shipping at year's end.

"It's a tight schedule, but we think we can hit it" said Paul Senior, vice president of product management and marketing at Airspan Networks (Uxbridge, England), a fixed wireless systems maker that plans to be among the first to ship systems using Intel Corp.'s upcoming Rosedale chip set.

"This is an execution year for us and the BWA industry with both products and interoperability plans. We have to have products," said Aditya Agarwal, a product planning manager for Fujitsu Microelectronics which is codeveloping a baseband chip for 802.16a, rev D with system maker Wi-LAN Inc. (Calgary, Alberta).

Senior said the new revision D of the standard brings two key additions to .16a. The revision defines a sub-channelization scheme that allows chipmakers to use smaller, cheaper power amplifiers. It also provides key hooks for using antenna diversity techniques such as multiple input, multiple output antennas.

"Rev D is what WiMax compatibility will be all about," he added.

About five chip makers are currently planning first-generation WiMax chips including Fujitsu and Intel which is working with a handful of OEMs including Airspan and Alvarion (San Jose). Wavesat Wireless Inc. (Dorval, Quebec) and at least one Taiwanese company also are said to be planning first-generation 802.16a chip sets as well. "Choosing Intel was for us a case of time-to-market," said Senior.

Realistically, WiMax members say it will be the first half of 2005 before systems start shipping in volume for outdoor deployments with the first indoor deployments and major carrier rollouts expected in the second half. An 802.16e standard for mobility and roaming, also to be ratified in the fall, is not expected to be supported in systems until 2006.