Although the International Telecommunication Union (ITU) will not release an official definition of wireless 4G technology until 2008/2009, there are already clear contenders for the designation, according to industry analyst In-Stat.

The primary 4G technologies expected to be identified in the ITU’s IMT-Advanced requirements are Long Term Evolution (LTE), Ultra Mobile Broadband (UMB), and IEEE 802.16m WiMAX, the research firm said

In-Stat analyst, Gemma Tedesco, said that two widely expected requirements for 4G technologies are that they be OFDMA-based, and that they support 100Mbps for wide area mobile applications.

But it is expected that mobile operators will initially deploy 4G very slowly, relying on their EV-DO or HSPA networks to provide for more ubiquitous coverage. In-Stat forecasts that with the dominant worldwide technology currently being GSM/EDGE, and HSPA and EV-DO handsets not expected to be dominant until 2012, 4G deployments will most likely start in the 2010-2012 timeframe.

“Companies are extremely uncomfortable talking about ‘4G’ technologies, since the ITU has not defined 4G yet,” said Tedesco. “However, each of the contending 4G technologies has a cheerleader, with Ericsson touting LTE, Qualcomm preferring UMB, and Intel touting 802.16m WiMAX.”

Drivers of LTE, UMB and 802.16m WiMAX adoption are likely to herald the re-allocation of older spectrum for 4G technologies, the resolution of any WiMAX IPR issues, and the creation of FDD profiles for 802.16e WiMAX. But Tedesco warns that realistically, initial implementations of LTE, UMB and 802.16m WiMAX may fall short of throughput and other expectations, with later enhancements, or even some type of technology combination, actually bringing real 4G to the table.