The Institute of Electrical and Electronics Engineers on Wednesday announced the approval of the standard, which is officially called 802.16e-2005.
Mobile WiMax is mobile broadband connectivity that allows roaming among base stations and a much farther reach than Wi-Fi.
The technology promises a range of several miles between client and base station and an average speed of as much as 40M bps per channel.
A standard for the fixed wireless version of WiMax, 802.16-2004, was ratified in June 2004.
Fixed WiMax allows clients to connect to a single base station, and is considered a solution for rural areas where landline connections might not be available.
Because landline connections are available throughout most of the country, industry proponents see Mobile WiMax as the flavor with the better chance for success in the United States.
However, ratification of the standard does not mean that products will be immediately available.
Interoperability testing wont start before the middle of 2006, according to several members of the WiMax Forum, an industry marketing consortium and interoperability certification body.
"My expectation is that well see [mobile] WiMax-certified products in early 2007," said Paul Sergeant, director of marketing for WiMax at Motorola Inc. in Schaumberg, Ill.
Motorola is working on a phone that supports Wi-Fi, cellular and WiMax networks, with plans to ship a prototype by the end of 2006, but such a phone is not likely to be commercially available until the end of 2007 at the earliest, Sergeant said.
In general, it may take a few years before WiMax chip sets are readily available in client devices.
"It may happen at some point in the future, but I dont think its going to happen in the short term," said Mark Whitton, general manager of wireless solutions at Nortel Networks Ltd., in Brampton, Ontario, in an interview last summer. "It took Wi-Fi four or five years before it was inexpensive enough to get into laptops."
WiMax chip sets are not likely to fall below $20 before 2010, according to a recent study from West Technology Research Solutions LLC, in Mountain View, Calif.
In the meantime, wireless carriers have been readying next-generation cellular technologies that may well compete against WiMax.
On Tuesday, Cingular Wireless launched a highest-speed data network service called BroadbandConnect in several major U.S. cities.
Based on HSDPA (high speed download packet access), the BroadbandConnect service provides average throughput rates of 400K bps to 700K bps, with bursts of up to a megabit per second, said officials at Cingular, in Atlanta.
Sergeant said mobile WiMax should be able to compete because it runs in a different spectrum band—2.5GHz in the United States—than 3G networks.
"Theres been no specialized 3G spectrum allocated in the U.S.," he said. "That spectrum is generally pretty crowded."