WiMAX is 3G

Call it a major victory for WiMAX as a technology and industry. For the first time, the International Telecommunications Union (ITU) has approved a non-cellular telecommunications technology as part of the union's 3G standards.

The decision, made at the ITU's Radiocommunication Sector's (ITU-R) general meeting in Geneva , Switzerland, means operators with 3G spectrum in the 2.5 GHz bands globally can use WiMAX to build out a network. Although each country's regulators ultimately decide, the ITU decision usually has a strong influence.

"This is a very special and unique milestone for WiMAX technology," Ron Resnick, president of the WiMAX Forum, said in a statement. "This is the first time that a new air interface has been added to the IMT-2000 set of standards since the original technologies were selected nearly a decade ago.  WiMAX technology currently has the potential to reach 2.7 billion people.  And today's announcement expands the reach to a significantly larger global population."

IMT-2000 (International Mobile Telecommunications-2000) was approved in 1999 with five cellular standards, including W-CDMA, cdma2000, TD-CDMA, EDGE, and DECT. It essentially meant that one of those technologies had to be used in 3G spectrum. WiMAX, which the ITU calls OFDMA TDD WMAN, had been locked out until the ITU-R decision. A working group approved WiMAX in June.

The ITU's approval likely won't resolve the debate over which is the best technology to use in the 2.57 GHz -2.69 GHz spectrum bands. The GSM community has plans to use orthogonal frequency division multiplexing (OFDM) in its future, with a proposed standard called Long Term Evolution (LTE). The GSM Association had opposed the inclusion of WiMAX in IMT-2000.

WiMAX, although it uses OFDMA, in its current form is a TDD (time division duplex) technology that separates signals by time slots. W-CDMA is a FDD (frequency division duplex) technology that separates signals by frequency. Engineers and companies argue over which is best.

Intel Vice President Sriram Viswanathan, who also is general manager of Intel's WiMAX business unit, says the ITU's decision means operators in emerging countries like India and Brazil that already have 2.5 GHz spectrum can use WiMAX for their network buildouts.

It also means that WiMAX could be used for the so-called IMT-2000 Extension Band allocations in some developed European countries later this year or next year. And it also makes WiMAX a possible inclusion in the ITU's 4G (IMT-Advanced) decisions expected in 2009.

Ironically, the ITU decision also labels WiMAX as a 3G technology although Sprint Nextel is calling it 4G for its planned network launch this year and next.

source: WiMAX is 3G By Brad Smith, WirelessWeek